JP2008101201A - Method for producing carboxyl group-containing acryl copolymer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing a thermoplastic copolymer which is excellent in heat resistance, colorless transparency and thermal stability and has controlled contents of foreign matter and evaporable components. <P>SOLUTION: This method for producing a carboxyl group-containing acryl copolymer (A) containing (i) alkyl unsaturated carboxylate units and (ii) unsaturated carboxylic acid units comprises feeding a raw material mixture comprising a monomer mixture, a chain transfer agent, and a radical polymerization initiator into an initial polymerization circulation line (I) in which one or more tubular reactors are built, and a non-circulation main polymerization line (II) in which one or more tubular reactors each having a static mixing structure therein are built, to continuously polymerize the raw material mixture so that the content of the carboxyl group-containing acryl copolymer (A) at the exit of the main polymerization line (II) is 50 to 90 wt.%, thus producing the copolymer solution (a) comprising the carboxyl group-containing acryl copolymer (A) and the unreacted raw material mixture. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention is excellent in heat resistance, molding processing characteristics, and colorless transparency, and particularly contains a glutaric anhydride unit-containing thermoplastic copolymer with little foreign matter, and unsaturated carboxylic acid alkyl ester units and unsaturated carboxylic acids as precursors thereof. The present invention relates to a method for producing a carboxyl group-containing acrylic copolymer (A) containing an acid unit.

  Polymethyl methacrylate (hereinafter also referred to as PMMA resin), (meth) acrylic acid ester monomer copolymer (also referred to as AC resin), polystyrene (hereinafter also referred to as PS resin), acrylonitrile-styrene copolymer (hereinafter referred to as AS) Resin), acrylonitrile-styrene-butadiene resin (hereinafter also referred to as ABS resin) and the like are generally produced by bulk polymerization, suspension polymerization, emulsion polymerization when industrially produced. A small portion is produced by solution polymerization.

  Bulk polymerization, suspension polymerization, and emulsion polymerization are convenient production methods for mass production, but it is difficult to control the copolymer composition and molecular weight distribution, as can be easily inferred from the polymerization mode. Many. Furthermore, in a polymerization method using water as a medium such as suspension polymerization and emulsion polymerization, an unsaturated monomer having a carboxyl group such as methacrylic acid, acrylic acid, maleic anhydride, and itaconic acid is copolymerized. It is difficult to impart functionality and compatibility with other polymers to the polymer, and it is difficult to improve the physical and chemical properties as a functional polymer and as a polymer alloy. I was trying. Furthermore, in bulk polymerization, suspension polymerization, and emulsion polymerization, it is very difficult to control the polymerization rate, and it is difficult to suppress the formation of a macromolecular polymer. For this reason, in the polymer, these macromolecular polymers are mixed as foreign matters, and when a film or a molded product is formed, there are cases where defects (such as fish and fish eyes) having the macromolecular polymer as a nucleus occur. Therefore, polymers produced by bulk polymerization, suspension polymerization, and emulsion polymerization have a problem that their use is limited in optical applications that require high transparency and uniformity.

  On the other hand, in solution polymerization, control of the copolymer composition and molecular weight distribution is relatively easy, and copolymerization of the unsaturated monomer having the water-soluble functional group is also possible. It was very difficult to separate and recover from the solution, and there was a problem that much labor and energy were required.

  As a method of solving such problems, a method of increasing the polymerization rate in solution polymerization or bulk polymerization and reducing the content of unreacted monomers and organic solvents in the polymerization solution obtained by these polymerization methods Has been proposed. For example, Patent Document 1 can improve the polymerization stability at a high polymerization rate, which has been a problem in methacrylic ester-based bulk polymerization, by continuously polymerizing PMMA resin using a complete mixing reactor, Therefore, a method capable of economically and advantageously producing a PMMA resin excellent in moldability is disclosed.

  However, even if the above polymerization method is applied to the copolymerization of unsaturated monomers having a carboxyl group such as methacrylic acid, it becomes difficult to control the polymerization rate by increasing the polymerization rate, and the polymerization is stably performed. It is difficult to proceed, and there has been a demand for a method capable of efficiently and stably producing an unsaturated monomer having a carboxyl group.

  Among the copolymers of unsaturated monomers having a carboxyl group, copolymers having unsaturated carboxylic acid units solve the heat resistance of acrylic resins by utilizing an intramolecular cyclization reaction by heat treatment. A possible method is disclosed in Patent Document 2, for example. However, the method of Patent Document 2 has a problem that the copolymer having glutaric anhydride units obtained by heat-treating the copolymer using an extruder is markedly colored.

  For this reason, if bulk polymerization or solution polymerization without using a so-called polymerization aid such as a dispersant or an emulsifier can be applied as a polymerization method of a copolymer containing an unsaturated carboxylic acid unit as a precursor, the optical material is required. Therefore, since it is expected to obtain a highly transparent copolymer having excellent colorless transparency, and the copolymerization composition and molecular weight distribution can be controlled by continuous polymerization, intensive studies have been conducted.

  For example, as a method of obtaining a copolymer containing the glutaric anhydride unit by bulk polymerization or solution polymerization, a copolymer containing unsaturated carboxylic acid alkyl ester units and unsaturated carboxylic acid units is bulk polymerization or solution Patent Document 3 or a method of polymerizing and subsequently heating the obtained polymerization solution, separating and removing unreacted monomers and unreacted monomers and solvent, and further heat-cyclizing the copolymer. 4.

  However, in the methods described in these publications, in order to completely remove the unreacted monomer and the solvent under a vacuum, a long-time heat treatment is required at a high temperature, which requires a great deal of labor and energy. Furthermore, there is a problem in that the resulting copolymer containing glutaric anhydride units is markedly colored.

In addition, according to these known examples, the continuous polymerization of the carboxyl group-containing acrylic carboxyl group-containing acrylic copolymer (A) of the present invention has been intensively studied. The resulting carboxyl group-containing acrylic carboxyl group-containing acrylic copolymer (A) Since it contains an unsaturated carboxylic acid unit, it has been found that the viscosity of the polymerization solution obtained by continuous polymerization tends to be high, and it is difficult to continuously operate at a high polymerization rate.
JP 09-286804 A (page 1-2, Examples) JP-A-49-85184 (page 1-2, Examples) Japanese Examined Patent Publication No. 61-49325 (Page 1-2, Examples) Japanese Examined Patent Publication No. 02-26641 (Page 1-2, Examples) JP 2004-002711 A (page 1-2, Examples)

  Therefore, the present invention has high heat resistance and excellent colorless and transparent molding processing characteristics, and at the same time, reduces foreign substances present in the copolymer required for optical materials, and further contains residual volatile components. It is an object of the present invention to provide a method for industrially advantageously producing a reduced thermoplastic copolymer having excellent thermal stability.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have obtained unsaturated carboxylic acid units and unsaturated carboxylic acid ester units, which are precursors of thermoplastic copolymers containing glutaric anhydride units. In the production of the copolymer containing, a circulation line (I) for initial polymerization incorporating one or more tubular reactors having a static mixing structure therein, and from this circulation line (I) Followed by bulk or solution polymerization in a continuous reactor with a non-circulating main polymerization line (II) incorporating one or more tubular reactors having static mixing structures therein, Volatilization under specific conditions separates and removes the unreacted monomer or a mixture of the unreacted monomer and the polymerization solvent, followed by intramolecular cyclization under specific conditions, Can be done with knowledge This is an economy that is easy to separate from unreacted monomer and polymerization solvent from copolymer, with colorless and transparent, excellent molding processing characteristics with excellent thermal stability, and high quality that satisfies low foreign matter In particular, the inventors have found that it is possible to produce a glutaric anhydride-containing copolymer predominately and arrived at the present invention.

  Conventionally, when the carboxyl group-containing acrylic copolymer (A) is continuously polymerized in a high polymerization rate region, there is often a problem that the polymerization cannot be stabilized due to high viscosity, but the carboxyl group-containing acrylic copolymer (A) is By using the polymerization apparatus of the present invention, it becomes possible to perform continuous polymerization stably even under a high content of the carboxyl group-containing acrylic copolymer (A) that becomes a highly viscous polymerization solution, which is disclosed in Patent Document 5. As a result, the present inventors have found that an effect not seen with PMMA resin can be obtained.

That is, the present invention
[1] A carboxyl group-containing acrylic copolymer containing (i) an unsaturated carboxylic acid alkyl ester unit and (ii) an unsaturated carboxylic acid unit using a continuous tubular reactor having a structure for static mixing therein ( In the production of A), a raw material mixture comprising an unsaturated carboxylic acid alkyl ester monomer and an unsaturated carboxylic acid monomer mixture, a chain transfer agent, and a radical polymerization initiator is statically mixed. A circulation line (I) for the initial polymerization incorporating one or more tubular reactors having a working structure therein, and a static mixing structure part continuing from this circulation line (I) Fed to a continuous reactor having a non-circulating main polymerization line (II) incorporating one or more tubular reactors, allowing the reaction liquid to pass while polymerizing and at the outlet of the main polymerization line (II) Polymerization is performed so that the content of the ruboxyl group-containing acrylic copolymer (A) is 50 to 90% by weight, and the copolymer solution (a) is composed of a carboxyl group-containing acrylic copolymer (A) and an unreacted raw material mixture. A process for producing a carboxyl group-containing acrylic copolymer (A),
[2] The organic solvent (B) for dissolving the carboxyl group-containing acrylic copolymer (A) is added to the raw material mixture in an amount of 1 to 200 parts by weight with respect to 100 parts by weight of the monomer, and continuous polymerization is performed. The method for producing the carboxyl group-containing acrylic copolymer (A) according to [1],
[3] The method for producing a carboxyl group-containing acrylic copolymer (A) according to [2], wherein the organic solvent (B) is at least one selected from ketones, ether compounds, and alcohols. ,
[4] The monomer mixture may be copolymerized with 5 to 50% by weight of unsaturated carboxylic acid, 50 to 95% by weight of unsaturated carboxylic acid alkyl ester and 100% by weight of the total monomer mixture. The method for producing a thermoplastic copolymer according to any one of the above [1] to [3], comprising 0 to 15% by weight of a monomer component,
[5] The amount of the chain transfer agent added is 0.1 to 2.0 parts by weight with respect to 100 parts by weight of the monomer mixture, according to any one of the above [1] to [4] Method for producing carboxyl group-containing acrylic copolymer (A),
[6] The method for producing a carboxyl group-containing acrylic copolymer (A) according to any one of [1] to [5], wherein the chain transfer agent is a mercaptan compound,
[7] Any of the above [1] to [6], wherein the radical polymerization initiator has a half-life of 0.01 to 60 minutes at each polymerization temperature of the circulation line (I) and the non-circulation line (II). A method for producing the carboxyl group-containing acrylic copolymer (A) according to 1),
[8] The method for producing a carboxyl group-containing acrylic copolymer (A) according to any one of [1] to [6], wherein the polymerization temperature in the circulation line (I) is 110 to 140 ° C. ,
[9] The polymerization temperature in the non-circulation line (II) is a temperature not lower than the polymerization temperature of the circulation line (I) and not higher than 200 ° C., [1] to [8] Method for producing carboxyl group-containing acrylic copolymer (A),
[10] Subsequent to the main polymerization line (II) (devolatilization step), the copolymer solution (a) is supplied to a continuous devolatilizer, and the unreacted monomer or the unreacted monomer and the organic solvent ( B) The method for producing a carboxyl group-containing acrylic copolymer (A) according to any one of [1] to [9], wherein the mixture is separated and removed,
[11] The above-mentioned [10], wherein the unreacted monomer separated or removed in the devolatilization step or a mixture of the unreacted monomer and the organic solvent (B) is recycled to the prepolymerization step. A method for producing a carboxyl group-containing acrylic copolymer (A),
[12] The carboxyl group-containing acrylic copolymer (A) obtained by the production method according to any one of [1] to [11] is heat-treated, and (i) dehydration and / or (b) dealcoholization. (Iii) Production of a thermoplastic copolymer (C) containing a glutaric anhydride unit represented by the following general formula (1) and (i) an unsaturated carboxylic acid alkyl ester unit. how to,

(However, R ¹ and R ² are the same or different and represent any one selected from a hydrogen atom and an alkyl group having 1 to 5 carbon atoms.)
[13] Provided is a method for producing a thermoplastic resin composition, in which a rubbery polymer (D) is further blended with the thermoplastic copolymer (C) obtained by the method according to [12]. .

  According to the present invention, it has high heat resistance and excellent molding processing characteristics such as colorless transparency, and at the same time, foreign substances present in the copolymer required for the optical material are reduced, and further the remaining volatile components are reduced. A thermoplastic copolymer excellent in thermal stability can be produced industrially advantageously.

  Hereinafter, the method for producing the carboxyl group-containing acrylic copolymer (A) and the thermoplastic copolymer (C) of the present invention will be specifically described.

  The carboxyl group-containing acrylic copolymer (A) of the present invention is a copolymer containing an unsaturated carboxylic acid alkyl ester unit and an unsaturated carboxylic acid unit, and the thermoplastic copolymer (C) of the present invention. Is a thermoplastic copolymer comprising (iii) a glutaric anhydride unit represented by the following general formula (1) and (i) an unsaturated carboxylic acid alkyl ester unit.

(In the above formula, R ¹ and R ² are the same or different and represent any one selected from a hydrogen atom and an alkyl group having 1 to 5 carbon atoms)

  Here, the thermoplastic copolymer containing the glutaric anhydride unit represented by the general formula (1) is basically produced by the steps shown below. That is, an unsaturated carboxylic acid alkyl ester monomer and an unsaturated carboxylic acid monomer that give the glutaric anhydride unit represented by the above general formula (1) by a subsequent heating step, and other vinyl series A process of producing a copolymer solution (a) containing a carboxyl group-containing acrylic copolymer (A) by copolymerizing with a vinyl monomer that gives the unit when the monomer unit is contained (polymerization) Step), and subsequently, the copolymer solution (a) is continuously supplied to the devolatilizer by a pump and heated under reduced pressure to continuously react with the unreacted monomer or the unreacted monomer. The step of separating and removing the mixture of the organic solvent (B) (devolatilization step), and further, the carboxyl group-containing acrylic copolymer (A) obtained in the devolatilization step is subjected to heat treatment, and (i) dehydration and / or Or (b) Intramolecular cyclization reaction by dealcoholization It is a manufacturing method comprising a step (cyclization step) of manufacturing by causing. In this case, typically, the carboxyl group of the 2-unit (ii) unsaturated carboxylic acid unit is dehydrated by heating the carboxyl group-containing acrylic copolymer (A), or adjacent (ii) unsaturated. One unit of the glutaric anhydride unit is produced by elimination of the alcohol from the carboxylic acid unit and (i) the unsaturated carboxylic acid alkyl ester unit.

  In the production of the carboxyl group-containing acrylic copolymer (A), the present invention provides a circulation line for initial polymerization (I) incorporating one or more tubular reactors having a structure for static mixing therein. ) And a non-circulating main polymerization line (II) incorporating one or more tubular reactors continuing from this circulation line (I) and having a static mixing structure therein It is important to.

  A preferred example of such a polymerization apparatus is shown in FIG. In the apparatus of FIG. 1, a plunger pump (1) for supplying a raw material to a tubular reactor for carrying out a polymerization reaction, a loop-type circulation polymerization line (I) formed by combining the tubular reactor, and further polymerization. A non-circulating polymerization line (II) for proceeding the reaction is arranged.

  In the example shown in FIG. 1, the circulation polymerization line (I) is composed of three tubular reactors (2), (3) and (4), and further comprises a circulation line (I) and a non-circulation line (II). A gear pump (5) for adjusting the flow rate to is installed.

  Further, a non-circulation polymerization line (II) is connected between the tubular reactor (4) and the gear pump (5), and the tubular reactors (7), (8) and (9) and the gear pump (10) are connected. is set up.

  Furthermore, between the cyclic polymerization line (I) and the non-circular polymerization line (main polymerization line, II), for the purpose of adding main raw materials such as a monomer mixture, auxiliary raw materials such as initiators, and additives. The side line (6) is connected, and by adopting such a configuration, it continuously contains a carboxyl group while maintaining a high polymerization rate that could not be achieved with a conventional tank-type polymerizer equipped with a stirrer. An acrylic carboxyl group-containing acrylic copolymer (A) can be produced.

  Moreover, in the manufacturing method of this invention, the method of manufacturing continuously by connecting the above-mentioned polymerization process, devolatilization process, and a cyclization process is more preferable. Here, an example of a schematic process diagram of the production method of the present invention is shown in FIG. According to the production method using FIG. 2, the polymerization apparatus (12) constituted by the tubular reactor described above is connected to the devolatilization apparatus (13), and the unreacted monomer, or the unreacted monomer and the organic The mixture of the solvent (B) was continuously devolatilized to obtain the carboxyl group-containing acrylic copolymer (A), and then the carboxyl group-containing acrylic copolymer (A) was continuously melted. The thermoplastic copolymer (C) containing glutaric anhydride units can be continuously produced by supplying the cyclization apparatus (14) to cyclization reaction.

  Furthermore, in addition to the above “polymerization step”, “devolatilization step” and “cyclization step”, the unreacted monomer separated or removed in the devolatilization step or a mixture of the unreacted monomer and the organic solvent (B) It is preferable to contain a “volatile component recovery step” as a recovered raw material for recovering, separating and purifying and recycling it to the polymerization step. Specifically, as shown in FIG. 1, separation is performed with a devolatilizer (13). Examples include a method of supplying the removed unreacted monomer or a mixture of the unreacted monomer and the organic solvent (B) to the cooling device (15) to obtain a recovered raw material.

  Hereinafter, each of these manufacturing steps will be specifically described.

[Polymerization process]
There is no restriction | limiting in particular as an unsaturated carboxylic acid monomer used at a superposition | polymerization process, Any unsaturated carboxylic acid monomer which can be copolymerized with another vinyl compound can be used. As a preferable unsaturated carboxylic acid monomer, the following general formula (2)

(However, R ³ represents any one selected from hydrogen and an alkyl group having 1 to 5 carbon atoms)
In particular, acrylic acid and methacrylic acid are preferred, and methacrylic acid is more preferred from the viewpoint of excellent thermal stability. These can be used alone or in combination. The unsaturated carboxylic acid monomer represented by the general formula (2) gives an unsaturated carboxylic acid unit having a structure represented by the following general formula (3) when copolymerized.

(However, R ⁴ represents any one selected from hydrogen and an alkyl group having 1 to 5 carbon atoms)

  Moreover, there is no restriction | limiting in particular as an unsaturated carboxylic-acid alkylester type monomer, However, As a preferable example, what is represented by following General formula (4) can be mentioned.

(Wherein R ⁵ represents any one selected from hydrogen and an alkyl group having 1 to 5 carbon atoms, and R ⁶ represents an unsubstituted or substituted C 1-6 aliphatic hydrocarbon group substituted with a hydroxyl group or halogen, and Represents any one selected from alicyclic hydrocarbon groups having 3 to 6 carbon atoms)

  Among these, an acrylate ester and / or a methacrylic ester having an aliphatic or alicyclic hydrocarbon group having 1 to 6 carbon atoms or the hydrocarbon group having a substituent is particularly preferable. The unsaturated carboxylic acid alkyl ester monomer represented by the general formula (4) gives an unsaturated carboxylic acid alkyl ester unit having a structure represented by the following general formula (5) when copolymerized.

(However, R ⁷ represents any one selected from hydrogen and an alkyl group having 1 to 5 carbon atoms, and R ⁸ is an aliphatic hydrocarbon group having 1 to 6 carbon atoms which is unsubstituted or substituted with a hydroxyl group or halogen, and Represents any one selected from alicyclic hydrocarbon groups having 3 to 6 carbon atoms)

  Preferred specific examples of unsaturated carboxylic acid alkyl ester monomers include methyl acrylate, ethyl acrylate, n-butyl acrylate, t-butyl acrylate, benzyl acrylate, 2-ethylhexyl acrylate, lauryl acrylate, Examples thereof include monomers such as dodecyl acrylate, methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, t-butyl methacrylate, benzyl methacrylate, lauryl methacrylate, dodecyl methacrylate, and trifluoroethyl methacrylate. Of these, methyl methacrylate and ethyl methacrylate are preferable, and methyl methacrylate is particularly preferable from the viewpoint of excellent optical characteristics and thermal stability. These may be used alone or as a mixture of two or more.

  Further, other vinyl monomers may be used as long as the effects of the present invention are not impaired. Preferable specific examples of other vinyl monomers include fragrances such as styrene, α-methylstyrene, o-methylstyrene, p-methylstyrene, o-ethylstyrene, p-ethylstyrene, and pt-butylstyrene. Vinyl cyanide monomers such as aromatic vinyl monomers, acrylonitrile, methacrylonitrile, ethacrylonitrile, etc., but includes aromatic rings in terms of transparency, birefringence, and chemical resistance Less monomers can be used more preferably. These may be used alone or in combination of two or more.

  In the present invention, the polymerization step is a method of polymerizing in a state containing the monomer mixture, a polymerization initiator and a chain transfer agent and substantially free of a solvent (bulk polymerization method), or a carboxyl group-containing acrylic copolymer. A polymerization method (solution polymerization method) in which an organic solvent (B) soluble in the coalescence (A) is added can be used. By adopting these polymerization methods, it is possible to obtain a thermoplastic copolymer (C) having a high degree of colorless transparency that could not be achieved by conventional techniques.

  The organic solvent (B) used in the solution polymerization method is not particularly limited as long as it is an organic solvent that is soluble in the carboxyl group-containing acrylic copolymer (A) as described above, but ketone, ether, amide And one or more selected from alcohols can be preferably used. Specific examples include acetone, methyl ethyl ketone, methyl-n-butyl ketone, methyl isobutyl ketone, ethyl isobutyl ketone, diethyl ether, tetrahydrofuran, dioxane, dimethylformamide. , Diethylformamide, dimethylacetamide, diethylacetamide, N-methylpyrrolidone, methanol, ethanol, isopropanol, ethylene glycol, propylene glycol, 2-methoxy-2-propanol, tetraglyme and other known solvents It can be used, in particular methyl ethyl ketone, methanol, isopropanol, and tetrahydrofuran are preferable.

  The addition amount in the case of adding the organic solvent (B) is 1 to 100 parts by weight with respect to 100 parts by weight of the monomer mixture from the viewpoint of the stability of the polymerization reaction, the recoverability in the devolatilization step, and the recyclability to the polymerization step. 200 parts by weight is preferable, more preferably 1 to 100 parts by weight, still more preferably 1 to 50 parts by weight, and most preferably 1 to 20 parts by weight. In addition, a bulk polymerization method substantially free of an organic solvent can be preferably used as long as the polymerization reaction can be sufficiently controlled.

  When the addition amount of the organic solvent (B) exceeds 200 parts by weight, solvent removal becomes insufficient in the subsequent devolatilization step and cyclization step, and the amount of gas generated in the thermoplastic copolymer (C) increases. Since thermal stability falls, it is not preferable. On the other hand, in order to reduce the residual solvent in order to reduce the amount of generated gas, the devolatilization and cyclization steps require treatment at high temperature for a long time, so that the thermoplastic copolymer (C) is markedly colored. Therefore, it is not preferable.

  In the present invention, controlling the dissolved oxygen concentration of the monomer mixture to 5 ppm or less in the polymerization step is excellent in colorless transparency, residence stability and heat of the thermoplastic copolymer (C) after the heat treatment. It is preferable because stability can be achieved. Furthermore, in order to further suppress coloring after the heat treatment, a preferable range of dissolved oxygen concentration is 0.01 to 3 ppm, and more preferably 0.01 to 1 ppm. When the dissolved oxygen concentration exceeds 5 ppm, the thermoplastic copolymer (C) after the heat treatment tends to be colored, and the thermal stability of the thermoplastic copolymer (C) is lowered. I can't reach my goal. Here, the dissolved oxygen concentration in the present invention is a value obtained by measuring dissolved oxygen in the polymerization solution using a dissolved oxygen meter (for example, DO meter B-505 manufactured by Iijima Electronics Co., Ltd., which is a galvanic oxygen sensor). is there. For the method of reducing the dissolved oxygen concentration to 5 ppm or less, a method of passing an inert gas such as nitrogen, argon or helium into the polymerization vessel, a method of bubbling an inert gas directly into the polymerization solution, or an inert gas before starting the polymerization A method of performing pressure relief once or twice after filling the polymerization vessel, a method of degassing the closed polymerization vessel before charging the monomer mixture, and then filling with an inert gas, A method of passing an inert gas through the polymerization vessel can be exemplified.

  A preferred ratio of the monomer mixture used in the production of the carboxyl group-containing acrylic copolymer (A) is 5 to 50% by weight of the unsaturated carboxylic acid monomer based on 100% by weight of the monomer mixture. %, More preferably 5-45% by weight, unsaturated carboxylic acid alkyl ester monomers are preferably 50-95% by weight, more preferably 55-95% by weight, and other vinyl monomers copolymerizable therewith. When using a monomer, the preferable ratio is 0 to 35 weight%, and an especially preferable ratio is 0 to 10 weight%.

  When the amount of the unsaturated carboxylic acid monomer is less than 5% by weight, the amount of the glutaric anhydride unit represented by the general formula (1) generated by heating the carboxyl group-containing acrylic copolymer (A) There is a tendency that the heat resistance improvement effect becomes small. On the other hand, when the amount of the unsaturated carboxylic acid monomer exceeds 50% by weight, a large amount of unsaturated carboxylic acid units tend to remain after the cyclization reaction by heating of the carboxyl group-containing acrylic copolymer (A). There is a tendency for colorless transparency and retention stability to decrease.

  The polymerization initiator used in the present invention uses a radical polymerization initiator having a half-life at a polymerization temperature described later of 0.1 to 60 minutes, more preferably 1 to 30 minutes, and most preferably 2 to 20 minutes. Is preferable from the viewpoint of polymerization stability. If this half-life is shorter than 0.1 minutes, the radical polymerization initiator decomposes before being uniformly dispersed in the polymerization reaction tank, so that the efficiency (starting efficiency) of the radical polymerization initiator is reduced. The amount increases and the thermal stability of the finally obtained thermoplastic copolymer decreases. On the other hand, if the half-life is longer than 60 minutes, a polymerized mass (scaling) is generated in the polymerization tank, and it becomes difficult to stably operate the polymerization. Further, after the polymerization is completed, the copolymer solution (a) Since unreacted radical polymerization initiator remains, high colorless transparency such as subsequent devolatilization or cyclization process and resin coloring due to residual radical polymerization initiator at the time of molding cannot be obtained. In this case, the object of the invention cannot be achieved.

  In the present invention, the “half-life of the radical polymerization initiator” is a value described in a product catalog of Kochi, such as Nippon Oil & Fats Co., Ltd. or Wako Pure Chemical Industries, Ltd.

  Examples of such radical polymerization initiators include tert-butyl peroxy-3,5,5-trimethylhexanate, tert-butyl peroxylaurate, tert-butyl peroxyisopropyl monocarbonate, tert-hexyl peroxyisopropyl. Monocarbonate, tert-butylperoxyacetate, 1,1-bis (tert-butylperoxy) 3,3,5-trimethylcyclohexane, 1,1-bis (tert-butylperoxy) cyclohexane, tert-butylperoxy 2-ethyl hexanate, tert-butyl peroxyisobutyrate, tert-hexyl peroxy 2-ethyl hexanate, di-tert-butyl peroxide, 2,5-dimethyl-2,5-bis (tert-butyl peroxy) Oxy) hexane, lauroyl peroxide, benzoyl peroxide, t-butylperoxyneodecanate, t-butylperoxypivalate, t-butylperoxy-2-ethylhexanoate, t-butylperoxybenzoate, dic Organic peroxides such as milperoxide, or 2- (carbamoylazo) -isobutyronitrile, 1,1′-azobis (1-cyclohexanecarbonitrile), 2,2′-azobisisobutyronitrile, 2 , 2′-azobis (2-methylbutyronitrile), dimethyl 2,2′-azobisisobutyrate, 2,2′-azobis (2,4,4-trimethylpentane), 2,2′-azobis ( 2-methylpropane), 2,2′-azobis-4-methoxy-2,4-dimethylvaleronitrile, 2,2 - the polymerization temperature from azo compounds such as azobis-2,4-dimethylvaleronitrile may be selected in consideration.

  The amount of the radical polymerization initiator used is determined by the polymerization temperature, the polymerization time (average residence time), and the target polymerization rate, but is preferably 0.001 with respect to 100 parts by weight of the monomer mixture. It is -2.0 weight part, More preferably, it is 0.01-2.0 weight part, More preferably, it is 0.01-1.0 weight part.

  Further, in the present invention, for the purpose of controlling the molecular weight, a chain transfer agent such as alkyl mercaptan, carbon tetrachloride, carbon tetrabromide, dimethylacetamide, dimethylformamide, triethylamine, etc. with respect to 100 parts by weight of the monomer mixture, It is preferable to add 0.1 to 2.0 parts by weight. Examples of the alkyl mercaptan used in the present invention include n-octyl mercaptan, t-dodecyl mercaptan, n-dodecyl mercaptan, n-tetradecyl mercaptan, n-octadecyl mercaptan and the like. Among them, t-dodecyl mercaptan, n-dodecyl mercaptan is preferably used.

  By polymerizing the addition amount of the chain transfer agent within the scope of the present invention, the weight average molecular weight (hereinafter also referred to as Mw) of the carboxyl group-containing acrylic copolymer (A) is 30,000 to 100,000, preferably 30,000 to 100,000. More preferably, it can control to 50000-80000. In addition, the weight average molecular weight as used in the field of this invention shows the weight average molecular weight in the absolute molecular weight measured by multi-angle light scattering gel permeation chromatography (GPC-MALLS).

  Those having an Mw of 30000 or more are preferable because the thermoplastic copolymer does not become brittle and the mechanical properties are good. In addition, those having Mw of 100,000 or less are preferable because high molecular weight substances that are not sufficiently melted or dissolved in melt-molded or solution-coated products do not remain as foreign matters, so that the defects of fish eyes and repelling do not occur. .

  Further, in the present invention, the inventors select a bulk polymerization method or a solution polymerization method as the polymerization step, so that the polymerization reaction proceeds in a substantially uniform mixed state, and a co-polymer having a homogeneous molecular weight distribution. We found that coalescence was obtained. Therefore, in a preferred embodiment, the carboxyl group-containing acrylic copolymer (A) has a molecular weight distribution (weight average molecular weight Mw / number average molecular weight Mn) of 1.5 to 3.0, and in a more preferred embodiment, 1.5. Those in the range of ~ 2.5 are obtained. When the molecular weight distribution is in the above range, the resulting thermoplastic copolymer tends to be excellent in moldability and can be preferably used. The molecular weight distribution (Mw / Mn) in the present invention is the weight average molecular weight (Mw) and number average molecular weight (Mn) in absolute molecular weight measured by multi-angle light scattering gel permeation chromatography (GPC-MALLS). The numerical value calculated from

  The production of the carboxyl group-containing acrylic copolymer (A) in the present invention is a reaction vessel in which a plurality of mixing structural parts having no moving parts are fixed inside, that is, a tubular reactor (having a static mixing structural part). In a continuous bulk polymerization line incorporating a tubular reactor), by performing continuous bulk polymerization or solution polymerization while performing static mixing with the tubular reactor, Continuous polymerization was possible in the polymer concentration range.

  As the plurality of mixing structural parts fixed inside the tubular reactor, for example, the polymerization liquid is mixed by changing the flow direction and flow direction of the polymerization liquid flowing into the pipe and repeating the division and merging. Examples of such tubular reactors include SMX type, SMR type sulzer type tubular mixers, Kenix type static mixers, Toray type tubular mixers, etc. SMR type sulzer-type tubular mixers are preferred.

  In the method for producing the polymer of the present invention, the polymerization temperature of the reaction solution needs to be substantially uniformly mixed in the range of 110 ° C. to 160 ° C. If the polymerization temperature is lower than 110 ° C., the polymerization rate due to the gel effect As a result of this acceleration phenomenon, it is possible to operate only at a low polymerization rate. When the temperature is higher than 160 ° C., dimer formation may occur, and the physical properties (transparency and mechanical strength) of the obtained polymer may be reduced. There is. In addition, the reaction temperature in each tubular reactor may be substantially constant, but is preferably 115 ° C. to 140 ° C. from the viewpoint of productivity and stereoregularity of the polymer before polymerization, and further after polymerization. In view of the necessity of further proceeding the polymerization, a temperature setting higher than the reaction conditions of the pre-polymerization is preferable.

  The average residence time in each reactor is preferably in the range of 1 to 7 hours. By setting it in this range, polymerization control is stabilized, and the thermoplastic copolymer (C) after the cyclization step tends to be improved in thermal stability. If the residence time is shorter than 1 hour, it is necessary to increase the amount of radical polymerization initiator used, and it becomes difficult to control the polymerization reaction. Preferably, it is 2 hours or more. Since productivity will fall when it exceeds 7 hours, More preferably, it is 6 hours or less.

  In order to efficiently control the weight average molecular weight and the number average molecular weight of the polymer after the polymerization, it is preferable to add a chain transfer agent.

  Each reactor generates heat due to the polymerization reaction and stirring. Therefore, the polymerization temperature is controlled by removing heat and optionally heating. Examples of the temperature control include a jacket, heat transfer heat removal or heating by circulation of a heat medium, cooling supply of a monomer mixture, and heating supply.

  In the last reactor, it is very important that the polymer content in the reaction mixture is substantially constant in the range of 40 to 100% by mass. For stable production, the polymer content is Is preferably in the range of 60 to 90 mass%, more preferably 65 to 85 mass%.

  When the carboxyl group-containing acrylic copolymer (A) of the present invention is produced using such a continuous polymerization line, the non-circulation polymerization line (main polymerization line, II) comprising one or more tubular reactors is used. Without flowing out, the flow rate of the mixed solution refluxed in the circulating polymerization line (I) composed of the tubular reactor is set to F1 (liter / hour), and flows out from the circulating polymerization line (I) to the non-circular polymerization line (II). The reflux ratio (R = F1 / F2) when the flow rate F2 (liter / hour) of the mixed solution is preferably in the range of 3-15.

Next, the polymerization method of the carboxyl group-containing acrylic copolymer (A) using the continuous polymerization line will be specifically described with reference to the process diagram of FIG. Cyclic polymerization having tubular reactors (2), (3) and (4) having a structure for static mixing of raw material monomer, radical polymerization initiator and solvent by a plunger pump (1) and a gear pump (5). Sent to line (I). In the circulation polymerization line (I), the polymerization proceeds while the polymerization solution is circulated, and a part of the polymerization solution is sent to the next non-circulation polymerization line (II). Here, the ratio of the flow rate of the polymerization liquid circulating in the circulation polymerization line (I) and the flow rate of the polymerization liquid flowing out to the non-circulation polymerization line (II), and the reflux ratio R are set in the non-circulation polymerization line (II). The flow rate of the mixed solution refluxed in the circulation polymerization line (I) without flowing out is defined as F1 (liter / hour), and the flow rate F2 of the mixed solution flowing out from the circulation polymerization line (I) into the non-circulation polymerization line (II) ( In general, R = F1 / F2 is preferably in the range of 3 to 15. In addition, in the polymerization in the circulation polymerization line (I), the total polymerization conversion rate of all monomers at the outlet of the circulation polymerization line (I) is usually 30 to 70% by mass, preferably 35 to 65% by mass. Polymerize in the same manner. A polymerization temperature of 115 to 140 ° C. is suitable. Further, a chain transfer agent is introduced from the side line (6) located at the connecting portion from the circulation polymerization line (I) to the non-circulation polymerization line (II) to greatly control the molecular weight of the polymer. The polymerization temperature in the non-circulation polymerization line (II) is usually a polymerization temperature of 140 to 160 ° C., and the polymerization is continuously performed until the polymerization rate becomes 60 to 90% by mass. In the case where the present invention is solution polymerization in which the organic solvent (B) is added, it is possible to set the polymerization rate to 100% so that all monomers are converted into polymers. Here, the polymerization rate (hereinafter sometimes referred to as φ) is calculated from the following equation by quantifying the unreacted monomer concentration (wt%) in the copolymer solution (a) and the charged raw material solution by gas chromatography. It is the value.
Polymerization rate (φ) = 100 × (1−M1 / M0)
Each symbol indicates the following numerical value.
M1 = Unreacted monomer concentration (% by weight) in the copolymer solution (a)
M0 = monomer concentration in the charged raw material solution (wt%)

  Next, this mixed solution is sent to a preheater and then to a devolatilization tank by a gear pump (10), and after removing unreacted monomers and solvent under reduced pressure, it is pelletized to obtain the desired composition. Is obtained.

Thus, by performing the polymerization reaction according to the polymerization conditions of the present invention, the polymer content in the resulting copolymer solution (a) can be controlled in the range of 20 to 90% by mass. In a more preferred embodiment, The polymer content is in the range of 30 to 80% by mass, more preferably 50 to 80% by mass. Here, the polymer content is the weight of the copolymer (a) obtained by diluting the copolymer solution (a) with tetrahydrafuran, reprecipitating the diluted solution in n-hexane and drying. Is a value calculated by the following formula.
Polymer content (% by weight) = {(A1-S0) / S0} × 100
Here, each symbol indicates the following numerical value.
A1 = weight (g) of the carboxyl group-containing acrylic copolymer (A) after drying
S0 = weight of copolymer solution (a) (g)

  When the polymer content is less than 20% by weight, in the next devolatilization step and cyclization step, high-temperature, long-time treatment is required to remove volatile components, and thus the resulting carboxyl group-containing The acrylic copolymer (A) or the thermoplastic copolymer (C) is not preferable because it causes coloring or thermal deterioration. On the other hand, the polymer content is 90%, the viscosity of the copolymer solution (a) increases, and it becomes difficult to feed the copolymer solution (a) to the subsequent devolatilization step by the gear pump (10). In addition, mixing and heat transfer in the polymerization reaction cannot be sufficiently performed, and the polymerization reaction cannot be stably performed, which is not preferable.

  In addition, since the solution viscosity of the copolymer solution (a) obtained under the polymerization conditions of the present invention is in the range of 0.1 to 5000 Pa · s, the solution is supplied to the devolatilizer in the devolatilization step by a known gear pump. Is preferred. Here, the solution viscosity of the copolymer solution (a) in the present invention is the viscosity of the copolymer solution (a) at 30 ° C. using a vibration viscometer (VM-100A manufactured by CBC Materials Co., Ltd.). It is a numerical value measured by holding.

[Volatilization process]
Further, in the method for producing a carboxyl group-containing acrylic copolymer (A) of the present invention, the copolymer solution (a) obtained in the polymerization step is subsequently supplied to a continuous devolatilizer, A devolatilization step for separating and removing the monomer or the mixture of the unreacted monomer and the organic solvent (B) can be suitably performed.

  The devolatilization temperature in this devolatilization step is preferably not less than the polymerization temperature and less than 300 ° C, more preferably not less than 200 ° C and less than 300 ° C.

  When the devolatilization temperature is 100 ° C. or lower, devolatilization becomes insufficient, and thus the organic solvent (B) that is an unreacted monomer or polymerization solvent is not sufficiently removed even in the next cyclization step, resulting in The thermal stability of the resulting thermoplastic copolymer (C) is lowered. Moreover, in the case of 200 degreeC or more, the thermoplastic copolymer (C) obtained will color by the thermal degradation of the carboxyl group containing acrylic copolymer (A) which is a residual unreacted monomer and precursor polymer. Colorless transparency decreases.

  In the devolatilization step, it is important that the pressure is a reduced pressure condition of 200 Torr or less, more preferably 100 Torr or less, and most preferably 50 Torr or less. Although there is no restriction | limiting in particular about the minimum of a pressure, It is 0.1 Torr or more substantially.

  When the pressure in the devolatilization step is 200 Torr or more, even if devolatilization is performed in the above temperature range, the unreacted monomer or the mixture of the unreacted monomer and the polymerization solvent cannot be separated and removed efficiently. Then, the next cyclization reaction becomes insufficient, the thermal stability of the resulting thermoplastic copolymer (C) is lowered, and the object of the present invention cannot be achieved.

  As a continuous devolatilizer for performing such devolatilization, it has a stirrer in which a cylindrical container and a plurality of stirrers are attached to a rotating shaft, and the copolymer solution (a) is supplied to one end of the tube part. An apparatus having a supply port for discharging and a discharge port for taking out the carboxyl group-containing acrylic copolymer (A) after devolatilization at the other end can be preferably used.

  Although there is no restriction | limiting in the number of rotating shafts, Usually, it is 1-5, Furthermore, 2-4 are preferable, More preferably, the biaxial stirring apparatus which has two rotating shafts is preferable.

  The number of stirring elements is preferably 10 to 50, and more preferably 20 to 30. The shape of the stirring element is not particularly limited, and may be a multi-leaf shape (for example, a clover leaf shape), may have holes or irregularities as appropriate, and may have a shape like a ship screw or a fan blade, Various other applications are possible. Moreover, since the effect | action which sends a reaction material will be obtained if a stirring element is made into a screw shape, it can use preferably.

  Specifically, a continuous twin-screw kneading device or a batch-type melt-kneading device having a vent is preferable, and a single screw extruder, twin screw extruder, twin screw / single screw combined type continuous kneading equipped with a “unimelt” type screw. Mention may be made of extruders, triaxial extruders, continuous or batch kneader type kneaders.

  Among these continuous devolatilizers, in particular, a biaxial extruder having a vent and a continuous biaxial reactor equipped with a plurality of convex lens type and / or elliptical plate-shaped paddles can be preferably used.

  A continuous biaxial reaction device provided with a plurality of convex lens type and / or elliptical plate-shaped paddles is a so-called high self-cleaning device without scale adhesion. In addition, a raw material supply port and a discharge port are provided at positions apart from the inner cavity (cylinder), a temperature control jacket is provided on the outer periphery of the cylinder, and the inside of the inner cavity is parallel to the longitudinal direction of the cylinder. The stirring shaft is provided with a plurality of plate-shaped paddles fixed so as to be close to each other.

  As such an extruder, specifically, “KRC kneader” manufactured by Kurimoto Iron Works can be preferably used.

  Since these continuous biaxial devices have a relatively large cylinder internal volume (effective volume), a sufficient heating reaction time can be secured, and the shape and / or arrangement of the paddle can be arbitrarily set. Accordingly, the heating reaction time (residence time) can be arbitrarily controlled, and thus the volatile components can be efficiently removed.

Said effective volume means the space volume V (cm < ³ >) in the state which inserted the stirring shaft provided with said various paddles in the cylinder. Here, the space volume in a state where the stirring shaft provided with the various paddles is not inserted is V ′ (cm ³ ), and the effective volume ratio can be calculated by the following equation.
Effective volume ratio (%) = (V / V ′) × 100

  At this time, a heat treatment apparatus having an effective volume ratio of 35% or more, particularly 40% or more can be preferably used. The upper limit of the effective volume ratio is usually about 50%.

  Here, the space volume V or V ′ can be calculated by calculation from the design drawing, but experimentally, the state in which the stirring shaft provided with the various paddles described above is inserted into the cylinder or not yet. It can be known by introducing water from the raw material port in the inserted state and with the discharge port, vent port, etc. closed, and measuring the amount of water filled in the cylinder.

  Moreover, in the devolatilization step of the production method of the present invention, a method of performing a devolatilization reaction with two or more devolatilizers arranged in series can be adopted, and a carboxyl group-containing acrylic carboxyl obtained after devolatilization. It is preferable at the point which reduces the residual volatile matter of a group containing acrylic copolymer (A).

  There is no limitation on the temperature in each devolatilizer when performing devolatilization using a plurality of devolatilizers. For example, if devolatilization is performed with two devolatilizers arranged in series, a polymerization tank and In the connected devolatilizer, the temperature is preferably not lower than the polymerization temperature and not higher than 250 ° C, and in the devolatilizer connected to the cyclizer, it is preferably not lower than 200 ° C and not higher than 300 ° C. .

  Moreover, the pressure in each devolatilizer when performing devolatilization using a plurality of devolatilizers is connected to the polymerization tank, for example, when devolatilization is performed with two devolatilizers arranged in series. In the devolatilizer, the volatile component can be efficiently removed by setting the pressure to 760 Torr (normal pressure condition) to 500 Torr, and then in the devolatilizer connected to the cyclization apparatus under the reduced pressure condition of 200 Torr or less. It is possible and preferable. Further, it is more preferably 100 Torr or less, and most preferably 50 Torr or less. Although there is no restriction | limiting in particular about the minimum of a pressure, It is 0.1 Torr or more substantially.

  An example of devolatilization using such a plurality of devolatilizers will be described with reference to a schematic process diagram shown in FIG. As shown in FIG. 3, two devolatilizers are arranged in series in the devolatilization process, and the devolatilizer connected to the polymerization tank (12) is connected to the pre-devolatilization process and the cyclization apparatus. Let the device be a post-devolatilization step. Specifically, the copolymer solution (a) obtained in the polymerization step is continuously added to the devolatilization apparatus (13-1) in the pre-devolatilization step in which the temperature is raised to the polymerization temperature or higher and 250 ° C. or lower. The carboxylic acid group-containing acrylic carboxyl group-containing acrylic copolymer (A) obtained in the previous devolatilization step was heated to 200 ° C. or higher and 300 ° C. or lower. After continuously supplying the devolatilization apparatus (13-2) in the post-devolatilization step and performing the post-devolatilization step, the resulting carboxyl group-containing acrylic carboxyl group-containing acrylic copolymer (A) is cyclized. Continuously fed to the process cyclizer (14).

  Thus, the carboxyl group-containing acrylic carboxyl group-containing acrylic copolymer (A) obtained through the devolatilization step is a residual unreacted monomer or a mixture of unreacted monomer and polymerization solvent (hereinafter collectively referred to as volatile components). In a preferred embodiment, it can be 5% by weight or less. In the subsequent cyclization step, (i) dehydration and / or (b) dealcoholization is efficiently performed. It is possible to proceed. Although there is no restriction | limiting in particular in the minimum of content of the volatile component in the carboxyl group-containing acrylic carboxyl group-containing acrylic copolymer (A) after a devolatilization process, It is 0.1 weight% or more substantially.

  Thus, in the carboxyl group-containing acrylic copolymer (A) obtained through the devolatilization step of the present invention, the content of the remaining unreacted monomer or a mixture of the unreacted monomer and the polymerization solvent is 10% by weight or less, In a preferred embodiment, it can be 5% by weight or less, and (i) dehydration and / or (b) dealcoholization can proceed efficiently in the subsequent cyclization step. Although there is no restriction | limiting in particular in the minimum of content of the volatile component in the carboxyl group-containing acrylic copolymer (A) after a devolatilization process, It is 0.1 weight% or more substantially.

[Volatile recovery process]
Moreover, in this invention, it is preferable to collect | recover the unreacted monomer removed by the said devolatilization process or the mixture of an unreacted monomer and an organic solvent (B), and to recycle in a superposition | polymerization process.

  Since the volatile component is vaporized in the devolatilization step in a reduced pressure heating state, the volatile component is recovered by passing it through a known cooling device such as a condenser-equipped distiller and recovering the volatile component as a liquid. It can be recycled again in the polymerization step as it is.

  Further, the volatile component recovered in a liquid state can be recycled in a polymerization step after being purified by distillation using a known distillation apparatus, if necessary.

  More preferably, in addition to the “polymerization step”, “devolatilization step” and “cyclization step”, the unreacted monomer separated or removed in the devolatilization step, or a mixture of the unreacted monomer and the organic solvent (B) It is preferable to contain a “volatile component recovery step” which is a recovered raw material for recovering, separating and refining and recycling to the polymerization step.

  The volatile component recovery process will be described in more detail with reference to the schematic process diagrams shown in FIGS. As shown in FIG. 2 or FIG. 3, since the volatile component is vaporized in the devolatilizer (13) in a reduced pressure heating state, the volatile component is supplied from the devolatilizer (13) to the cooling device (15). It can be recovered as a state and recycled again in the polymerization step as it is. Here, there is no particular limitation on the method of supplying the volatile component containing the unreacted monomer separated or removed in the devolatilization step or the mixture of the unreacted monomer and the organic solvent (B) to the cooling device (15). And a method using an exhaust device such as an ejector, a blower or a vacuum pump. The cooling device (15) is not particularly limited, and examples thereof include a known condenser, a condenser-equipped distiller, and the like. In this cooling device, the volatile components are cooled and agglomerated to form a recovered liquid, which is recycled in the polymerization tank (12). Is done.

  Also, as shown in FIG. 3 or 4, the recovered liquid obtained by the cooling device (15) is supplied to a purification device (16) such as a flash tower, a demister, a distillation tower, etc., purified and separated, and a polymerization tank (12). The method of recycling in can also be used preferably.

  In addition, as shown in FIG. 5, the volatile components separated and removed by the devolatilizer (13) are supplied to the purifier (16) without agglomeration, and after purification and separation, the recovered liquid is supplied to the cooling device (15). In addition, a method of cooling, agglomerating and using the recovered raw material can be preferably used.

  As described above, in the production method of the present invention, the volatile component separated and removed in the devolatilization step is recovered in the volatile component recovery step and recycled as a recovered raw material in the polymerization tank (12), which is economically advantageous. It is possible to produce a carboxyl group-containing acrylic carboxyl group-containing acrylic copolymer (A).

[Cyclization process]
Further, the present inventors heated the carboxyl group-containing acrylic copolymer (A) obtained by the production method of the present invention, and carried out an intramolecular cyclization reaction by (i) dehydration and / or (b) dealcoholization. It has been found that by producing a thermoplastic copolymer (C) containing glutaric anhydride units, unprecedented high colorless transparency and thermal stability can be achieved, and the carboxyl group of the present invention By adopting the continuous polymerization method of the acrylic copolymer (A), the thermoplastic copolymer (C) can be produced industrially advantageously.

  Moreover, since the carboxyl group-containing acrylic copolymer (A) after the devolatilization step is obtained as a high-temperature melt, it can be easily introduced into the next cyclization step, and the cyclization reaction can be carried out continuously as it is. Therefore, the thermoplastic copolymer (C) can be produced economically advantageously from this point.

  As an apparatus used for this cyclization reaction, a continuous kneading extrusion apparatus is preferable, and the temperature for the cyclization reaction is preferably 200 to 350 ° C, more preferably 250 to 330 ° C.

  When a batch-type kneading device or a stationary vacuum high-temperature bath is used as the cyclization device, it takes a long time to complete the cyclization reaction, so the resin is colored and a high degree of colorless transparency cannot be obtained. The object of the present invention cannot be achieved.

  On the other hand, when the cyclization temperature is 200 ° C. or lower, the cyclization reaction is insufficient, the thermal stability of the resulting thermoplastic copolymer (C) is lowered, and an attempt is made to complete the cyclization reaction at the temperature. Then, since the cyclization reaction takes a long time, the resin is colored due to thermal degradation. On the other hand, if the cyclization temperature is 350 ° C. or higher, the resin is colored due to thermal deterioration, and a high degree of colorless transparency cannot be obtained. If the temperature range deviates from the above, the object of the present invention cannot be achieved.

  Specifically, as a continuous kneading and extruding apparatus in the cyclization process, a single-screw extruder, a twin-screw or a tri-screw extruder equipped with a “unimelt” type screw, a continuous kneader-type kneader, or the like is used. In particular, a twin-screw extruder can be preferably used.

  In addition, in the cyclization step of the present invention, when an intramolecular cyclization reaction is performed by heating in the presence of oxygen, the yellowness tends to deteriorate, so the system is sufficiently replaced with an inert gas such as nitrogen. It is preferable to do.

  Further, the heat treatment time in the cyclization step at this time is not particularly limited and can be appropriately set according to the desired copolymer composition, but is usually 1 minute to 60 minutes, preferably 2 minutes to 30 minutes, especially A range of 3 to 20 minutes is preferred. In particular, the ratio of the screw diameter (D) of the extruder to the length (L) of the screw (L / D) in order to ensure a sufficient heating time for advancing the intramolecular cyclization reaction using an extruder. Is preferably 40 or more. When an extruder with a short L / D is used, a large amount of unreacted unsaturated carboxylic acid units remain, so that the reaction proceeds again during the heat molding process, and there is a tendency for silver and bubbles to be seen in the molded product and molding retention. Sometimes the color tends to deteriorate significantly.

  Further, among the continuous kneading extruders used in the cyclization step, a thermoplastic copolymer excellent in colorless transparency and mechanical properties tends to be obtained by using a biaxial / single screw composite type continuous kneading extruder. Therefore, it can be preferably used. Here, the biaxial / single-shaft combined continuous kneading extruder is a biaxial screw portion in which a first shaft and a second shaft in which a screw portion is formed are arranged in parallel in an extruder casing, and a biaxial screw A single screw portion in which a first shaft extended from the screw portion is disposed, and a flow rate adjusting mechanism is provided in a communication portion between the biaxial screw portion and the single screw portion, and the casing communicates with the biaxial screw portion. A twin-screw / single-shaft composite continuous kneading extruder having a raw material supply port and a discharge port communicating with the end of the extended first shaft, and as a commercially available extruder of this type Is an “HTM type extruder” manufactured by CTE. When the raw material carboxyl group-containing acrylic copolymer (A) is heat-treated in a continuous manner to advance the cyclization reaction, the melt viscosity increases as the reaction proceeds, and heat is generated due to the shearing of the extruder. Tends to increase and coloring due to thermal decomposition of the molecular main chain tends to increase. Further, the shear heat generation becomes larger when melt kneading with a twin screw than with a single screw. On the other hand, from the viewpoint of reaction rate, it is preferable to melt and knead with a twin screw. From the above, by using a specific twin-screw / single-screw composite continuous kneading extruder, in the initial reaction stage where the melt viscosity is relatively low, the melt viscosity is secured while ensuring a sufficient reaction speed with a twin screw. In the later stage of the reaction when the temperature is relatively high, heat treatment with a single screw portion that suppresses heat generation by shearing suppresses thermal decomposition of the molecular main chain, so that the heat containing the resulting glutaric anhydride-containing unit is reduced. It is speculated that the plastic carboxyl group-containing acrylic copolymer (A) is particularly excellent in color tone and mechanical properties.

  In the present invention, a continuous biaxial reactor equipped with a plurality of convex lens type and / or elliptical plate-shaped paddles is also used as a continuous kneading extruder. It can be preferably used from the viewpoint of obtaining a polymer. This type of device is a so-called high self-cleaning device without scale adhesion. In addition, a raw material supply port and a discharge port are provided at positions apart from the inner cavity (cylinder), a temperature control jacket is provided on the outer periphery of the cylinder, and the inside of the inner cavity is parallel to the longitudinal direction of the cylinder. The stirring shaft is provided with a plurality of plate-shaped paddles fixed so as to be close to each other.

  As such an extruder, specifically, “KRC kneader” manufactured by Kurimoto Iron Works can be preferably used.

  Furthermore, as a continuous kneader, it has a container having a jacket for a heating medium around it, and has at least two stirring shafts inside thereof, and a plurality of scraping blades are attached to the shafts, When the shafts rotate in the same direction or in different directions, the blades are (a) attached to each other so that the blades attached to the shafts do not collide with each other, and the tip of the blade is free from the inner surface of the container. (B) The blades attached to each shaft are arranged so as to be aligned on the same plane perpendicular to the axial direction, and the tip of the blade is It rotates while keeping a slight gap with the inner surface of the container and the surface of the other blade, thereby kneading the molten carboxyl group-containing acrylic copolymer (A) and constantly updating its surface. Te, continuous biaxial stirring device having a function to be allowed to proceed cyclization reaction is preferred.

  As a specific example of such a continuous biaxial stirring device, a horizontal stirring device with good surface renewability shown in Japanese Patent Publication No. 58-11450 and Japanese Patent Publication No. 61-52850 is suitable. Examples thereof include a spectacle blade manufactured by Co., Ltd., a lattice blade reactor, an SCR manufactured by Mitsubishi Heavy Industries, Ltd., an NSCR type reactor, an SC processor, and BIVOLAK manufactured by Sumitomo Heavy Industries, Ltd.

  In addition, the temperature which heat-processes the original carboxyl group-containing acrylic copolymer (A) of this invention, and manufactures a thermoplastic copolymer (C) is (i) dehydration reaction and / or (b) dealcoholization reaction. Although it will not specifically limit if it is the temperature which intramolecular cyclization reaction produces, Preferably it is the range of 200-350 degreeC, Especially the range of 200-315 degreeC is preferable.

  In addition, the time for the heat treatment at this time is not particularly limited, and can be appropriately set according to the desired copolymer composition. Usually, it is 3 minutes to 60 minutes, preferably 5 minutes to 30 minutes, especially 8 to 20 minutes. A range of minutes is preferred.

  The content of the glutaric anhydride unit represented by the general formula (1) in the thermoplastic copolymer (C) of the present invention is not particularly limited, but preferably in 100% by weight of the thermoplastic copolymer. Preferably, it is 5 to 50% by weight, more preferably 10 to 50% by weight, still more preferably 10 to 45% by weight, and particularly preferably 10 to 30% by weight.

In addition, an infrared spectrophotometer or a proton nuclear magnetic resonance ( ¹ H-NMR) measuring instrument is generally used for quantification of each component unit in the thermoplastic copolymer of the present invention. In infrared spectroscopy, glutaric anhydride units, absorption of 1800 cm ^-1 and 1760 cm ^-1 are characteristic can be distinguished from unsaturated carboxylic acid units and unsaturated carboxylic acid alkyl ester unit. In the ¹ H-NMR method, for example, in the case of a copolymer consisting of a glutaric anhydride unit, methacrylic acid, and methyl methacrylate, the attribution of the spectrum in dimethyl sulfoxide heavy solvent is 0.5 to 1.5 ppm. Peak of methacrylic acid, methyl methacrylate and glutaric anhydride ring compound α-methyl group hydrogen, 1.6 to 2.1 ppm peak of polymer main chain methylene group hydrogen, 3.5 ppm peak of methacrylic acid Copolymer composition can be determined from hydrogen of carboxylic acid ester of methyl acid (—COOCH ₃ ), a peak of 12.4 ppm and hydrogen of carboxylic acid of methacrylic acid and an integral ratio of the spectrum. In addition to the above, when styrene is contained as another copolymerization component, hydrogen in the aromatic ring of styrene is found at 6.5 to 7.5 ppm, and the copolymer composition is similarly determined from the spectral ratio. can do.

  Further, the thermoplastic copolymer of the present invention contains an unsaturated carboxylic acid unit and / or another copolymerizable vinyl monomer unit in addition to the components (i) and (ii). Can do.

  In the present invention, the unsaturated carboxylic acid unit contained in the thermoplastic copolymer by sufficiently performing (ii) dehydration and / or (ii) dealcoholization reaction of the carboxyl group-containing acrylic copolymer (A). The amount is preferably 10% by weight or less, that is, 0 to 10% by weight, and more preferably 0 to 5% by weight. When the unsaturated carboxylic acid unit exceeds 10% by weight, colorless transparency and residence stability tend to be lowered.

  The amount of other copolymerizable vinyl monomer units is preferably 0 to 35% by weight, more preferably 10% by weight or less, that is, 0 to 10% by weight, further preferably 0 to 0% by weight. 5% by weight. In particular, when an aromatic vinyl monomer unit such as styrene is contained, if the content is too large, the colorless transparency, optical isotropy, and chemical resistance tend to decrease.

  The thermoplastic copolymer (C) of the present invention preferably has a weight average molecular weight (hereinafter also referred to as Mw) of preferably 30,000 to 100,000, more preferably 50,000 to 100,000. In addition, the weight average molecular weight as used in the field of this invention shows the weight average molecular weight in the absolute molecular weight measured by multi-angle light scattering gel permeation chromatography (GPC-MALLS).

  The thermoplastic copolymer (C) of the present invention thus obtained has excellent heat resistance with a glass transition temperature of 120 ° C. or higher, and is preferable in terms of practical heat resistance. Further, in a preferred embodiment, the glass transition temperature has extremely excellent heat resistance of 130 ° C. or higher. Moreover, as an upper limit, it is about 160 degreeC normally. The glass transition temperature here is a glass transition temperature measured at a heating rate of 20 ° C./min using a differential scanning calorimeter (DSC-7 manufactured by Perkin Elmer).

  In the preferred embodiment, the thermoplastic copolymer (C) produced by the production method of the present invention has a yellowness index value of 3 or less and coloring is suppressed, and in a more preferred embodiment, 2 or less. It has extremely high colorless transparency. In the above, the yellowness is a value obtained by measuring the YI value of a 1 mm-thick molded product injection-molded at a glass transition temperature + 140 ° C. according to JIS-K7103. The lower limit of the yellowness is not particularly limited and is preferably as low as possible, but is usually about 1.

  The thermoplastic copolymer (C) produced by the production method of the present invention is a residual unreacted monomer or a mixture of an unreacted monomer and a polymerization solvent (hereinafter collectively referred to as a volatile component). Is reduced to 5% by weight or less, and in a preferred embodiment, 3% by weight or less. Further, the heating loss when heated at a glass transition temperature + 130 ° C. for 30 minutes (hereinafter referred to as gas generation amount). In a preferred embodiment of 1.0% by weight or less, in a more preferred embodiment of 0.5% by weight, most preferably 0.3% by weight or less, and a high thermal stability that could not be achieved by conventional methods. Have The lower limit of the volatile component content and gas generation amount is not particularly limited and is preferably as low as possible, but is usually about 0.1% by weight.

  In the thermoplastic copolymer (C) of the present invention, the melt viscosity measured at a glass transition temperature + 130 ° C. and a shear rate of 12 / sec is 100 to 10,000 Pa · s or less in a preferred embodiment, and in a more preferred embodiment. It has a high fluidity of 100 to 5000 Pa · s, and in the most preferred embodiment 100 to 2000 Pa · s or less, and is excellent in molding processability. The melt viscosity referred to here is the melt viscosity (Pa · s) measured at the above temperature and shear rate using a Capillograph type 1C (die diameter φ1.0 mm, die length 5.0 mm) manufactured by Toyo Seiki Co., Ltd. .

  Further, at the time of producing the thermoplastic copolymer (C) of the present invention, hindered phenol-based, benzotriazole-based, benzophenone-based, benzoate-based and cyanoacrylate-based UV absorbers and Antioxidants, higher fatty acids, acid esters and acid amides, lubricants and plasticizers such as higher alcohols, release agents such as montanic acid and salts thereof, esters thereof, half esters, stearyl alcohol, stearamide and ethylene wax , Anti-coloring agents such as phosphites and hypophosphites, halogen flame retardants, phosphorous and silicone non-halogen flame retardants, nucleating agents, amines, sulfonic acids, polyethers, etc. Additives such as colorants such as inhibitors and pigments may be optionally added. However, it is necessary to add the color within a range in which the color of the additive does not adversely affect the thermoplastic copolymer (C) of the present invention and the transparency does not deteriorate.

  The thermoplastic copolymer (C) produced according to the present invention makes use of its excellent heat resistance, colorless transparency and retention stability, and is used for electrical / electronic parts, automobile parts, mechanical mechanism parts, OA equipment, home appliances. It can be used for various uses such as housings and their parts and general sundries.

  In addition, the thermoplastic copolymer (C) obtained by the above method is excellent in mechanical properties and molding processability and can be melt-molded, so that extrusion molding, injection molding, press molding, etc. are possible. And can be used after being formed into a film, sheet, tube, rod, or other molded article having any desired shape and size.

  In particular, a known method can be used as a method for producing a film made of the thermoplastic copolymer (C). That is, production methods such as an inflation method, a T-die method, a calendar method, a cutting method, a casting method, an emulsion method, and a hot press method can be used. Preferably, an inflation method, a T-die method, a cast method or a hot press method can be used. In the case of a production method using an inflation method or a T-die method, an extruder type melt extrusion apparatus equipped with a single screw or twin screw can be used. The melt extrusion temperature for producing the film of the present invention is preferably 150 to 350 ° C, more preferably 200 to 300 ° C. Moreover, when melt-kneading using a melt-extrusion apparatus, it is preferable to perform the melt-kneading under reduced pressure or the melt-kneading under nitrogen stream from a viewpoint of coloring suppression. When the film of the present invention is produced by the casting method, solvents such as tetrahydrofuran, acetone, methyl ethyl ketone, dimethylformamide, dimethyl sulfoxide, N-methylpyrrolidone can be used. Preferred solvents are acetone, methyl ethyl ketone, N-methylpyrrolidone and the like. The film is prepared by dissolving the thermoplastic resin composition of the present invention in one or more of the above solvents, and using the solution with a bar coater, a T die, a T die with a bar, a die coat, etc. It can be produced by casting on a flat plate or curved plate (roll) such as a film, steel belt, or metal foil and using a dry method in which the solvent is removed by evaporation, or a wet method in which the solution is solidified with a coagulating liquid.

  Moreover, in this invention, it is excellent without impairing the outstanding characteristic of a thermoplastic copolymer (C) by containing a rubber-containing polymer (D) in said thermoplastic copolymer (C). High impact resistance can be imparted.

  The rubber-containing polymer (D) used in the present invention is composed of a layer containing one or more rubber-like polymers and one or more layers made of different polymers, and 1 inside. A multilayer structure polymer called a core-shell type having a structure containing a rubber polymer of more than one layer, or a monomer mixture composed of a vinyl monomer in the presence of a rubber polymer is copolymerized. Graft copolymers and the like can be preferably used.

  The number of layers constituting the core-shell type multilayer structure polymer used in the present invention may be two or more, and may be three or more or four or more. A multilayer structure polymer having a layer (core layer) is preferred.

  In the multilayer structure polymer of the present invention, the kind of the rubber layer is not particularly limited as long as it is composed of a polymer component having rubber elasticity. For example, acrylic monomers, silicone monomers, styrene monomers, nitrile monomers, conjugated diene monomers, monomers that form urethane bonds, ethylene monomers, propylene monomers Examples thereof include rubbers formed by polymerizing monomers and isobutene monomers. Preferred rubbers include, for example, acrylic units such as ethyl acrylate units and butyl acrylate units, silicone units such as dimethylsiloxane units and phenylmethylsiloxane units, styrene units such as styrene units and α-methylstyrene units, It is a rubber composed of nitrile units such as acrylonitrile units and methacrylonitrile units, and conjugated diene units such as butadiene units and isoprene units. A rubber composed of a combination of two or more of these components is also preferred. For example, (1) rubber composed of acrylic units such as ethyl acrylate units and butyl acrylate units and silicone units such as dimethylsiloxane units and phenylmethylsiloxane units, and (2) ethyl acrylate units and butyl acrylate. Rubber composed of acrylic units such as units and styrene units such as styrene units and α-methylstyrene units, (3) acrylic units such as ethyl acrylate units and butyl acrylate units, butanediene units, and isoprene units And (4) acrylic units such as ethyl acrylate units and butyl acrylate units, silicone units such as dimethylsiloxane units and phenylmethylsiloxane units, styrene units and α- Methyl styrene unit The rubber | gum comprised from which styrenic unit is mentioned. Of these, rubbers containing alkyl acrylate units and substituted or unsubstituted styrene units are most preferred from the viewpoint of transparency and mechanical properties. In addition to these components, a rubber obtained by crosslinking a copolymer composed of a crosslinking component such as a divinylbenzene unit, an allyl acrylate unit, and a butylene glycol diacrylate unit is also preferable.

  In the multilayer structure polymer of the present invention, the type of layer other than the rubber layer is not particularly limited as long as it is composed of a polymer component having thermoplasticity, but the glass transition temperature is higher than that of the rubber layer. A high polymer component is preferred. Polymers having thermoplastic properties include unsaturated carboxylic acid alkyl ester units, unsaturated carboxylic acid units, unsaturated glycidyl group-containing units, unsaturated dicarboxylic anhydride units, aliphatic vinyl units, aromatic vinyl units, cyanide. Examples thereof include polymers containing one or more units selected from vinyl units, maleimide units, unsaturated dicarboxylic acid units, and other vinyl units. Among them, a polymer containing an unsaturated carboxylic acid alkyl ester unit is preferable, and in addition, one or more units selected from an unsaturated glycidyl group-containing unit, an unsaturated carboxylic acid unit and an unsaturated dicarboxylic anhydride unit are contained. More preferred is a polymer.

  Although it does not specifically limit as a monomer used as the raw material of the said unsaturated carboxylic acid alkylester unit, Acrylic acid alkylester or methacrylic acid alkylester is used preferably. Specifically, methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, n-propyl acrylate, n-propyl methacrylate, n-butyl acrylate, n-butyl methacrylate, t-butyl acrylate , T-butyl methacrylate, n-hexyl acrylate, n-hexyl methacrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, cyclohexyl acrylate, cyclohexyl methacrylate, stearyl acrylate, stearyl methacrylate, octadecyl acrylate , Octadecyl methacrylate, phenyl acrylate, phenyl methacrylate, benzyl acrylate, benzyl methacrylate, chloromethyl acrylate, chloromethyl methacrylate, 2-chloroethyl acrylate, methacrylic acid -Chloroethyl, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 3-hydroxypropyl acrylate, 3-hydroxypropyl methacrylate, 2,3,4,5,6-pentahydroxyhexyl acrylate, methacrylic acid 2 , 3,4,5,6-pentahydroxyhexyl, 2,3,4,5-tetrahydroxypentyl acrylate, 2,3,4,5-tetrahydroxypentyl methacrylate, aminoethyl acrylate, propylamino acrylate Examples include ethyl, dimethylaminoethyl methacrylate, ethylaminopropyl methacrylate, phenylaminoethyl methacrylate, and cyclohexylaminoethyl methacrylate. From the viewpoint that the effect of improving impact resistance is great, methyl acrylate or methyl methacrylate is preferably used. These units can be used alone or in combination of two or more.

  The unsaturated carboxylic acid monomer is not particularly limited, and examples thereof include acrylic acid, methacrylic acid, maleic acid, and further a hydrolyzate of maleic anhydride. In particular, acrylic acid and methacrylic acid are preferable from the viewpoint of excellent thermal stability, and methacrylic acid is more preferable. These can be used alone or in combination.

  The monomer used as a raw material for the unsaturated glycidyl group-containing unit is not particularly limited, but is glycidyl acrylate, glycidyl methacrylate, glycidyl itaconate, diglycidyl itaconate, allyl glycidyl ether, styrene-4-glycidyl. Examples include ether and 4-glycidylstyrene, and glycidyl acrylate or glycidyl methacrylate is preferably used from the viewpoint that the effect of improving impact resistance is great. These units can be used alone or in combination of two or more.

  Examples of the monomer used as the raw material for the unsaturated dicarboxylic acid anhydride unit include maleic anhydride, itaconic anhydride, glutaconic anhydride, citraconic anhydride, and aconitic anhydride, which have the effect of improving impact resistance. From the viewpoint of being large, maleic anhydride is preferably used. These units can be used alone or in combination of two or more.

  Moreover, ethylene, propylene, butadiene, etc. can be used as a monomer used as the raw material of the said aliphatic vinyl unit. Examples of the monomer used as a raw material for the aromatic vinyl unit include styrene, α-methylstyrene, 1-vinylnaphthalene, 4-methylstyrene, 4-propylstyrene, 4-cyclohexylstyrene, 4-dodecylstyrene, and 2-ethyl. -4-Benzylstyrene, 4- (phenylbutyl) styrene, halogenated styrene and the like can be used. Acrylonitrile, methacrylonitrile, ethacrylonitrile, etc. can be used as a monomer as a raw material for the vinyl cyanide unit. Examples of the monomer used as a raw material for the maleimide unit include maleimide, N-methylmaleimide, N-ethylmaleimide, N-propylmaleimide, N-isopropylmaleimide, N-cyclohexylmaleimide, N-phenylmaleimide, N- (p- Bromophenyl) maleimide and N- (chlorophenyl) maleimide can be used. As a monomer used as the raw material of the unsaturated dicarboxylic acid unit, maleic acid, maleic acid monoethyl ester, itaconic acid, phthalic acid, and the like can be used. Examples of other monomers used as a raw material for vinyl units include acrylamide, methacrylamide, N-methylacrylamide, butoxymethylacrylamide, N-propylmethacrylamide, N-vinyldiethylamine, N-acetylvinylamine, allylamine, and methallylamine. N-methylallylamine, p-aminostyrene, 2-isopropenyl-oxazoline, 2-vinyl-oxazoline, 2-acryloyl-oxazoline, 2-styryl-oxazoline, and the like can be used. These monomers can be used alone or in combination of two or more.

  In the multilayer structure polymer containing the rubber polymer of the present invention, the type of the outermost layer (shell layer) is, as described above, an unsaturated carboxylic acid alkyl ester unit, an unsaturated carboxylic acid unit, an unsaturated glycidyl group-containing unit, From polymers containing one or more types of units such as aliphatic vinyl units, aromatic vinyl units, vinyl cyanide units, maleimide units, unsaturated dicarboxylic acid units, unsaturated dicarboxylic anhydride units, and other vinyl units. There may be mentioned at least one selected. Among these, at least one selected from polymers containing unsaturated carboxylic acid alkyl ester units, unsaturated carboxylic acid units, unsaturated glycidyl group-containing units, unsaturated dicarboxylic acid anhydride units, and the like is preferable.

In the present invention, as the rubbery polymer (D) used for melt-kneading with the thermoplastic copolymer (C), a polymer containing an unsaturated carboxylic acid alkyl ester unit and an unsaturated carboxylic acid unit is the most preferred. It is most preferable to use a multilayer structure polymer as an outer layer.
When the outermost layer is a polymer containing an unsaturated carboxylic acid alkyl ester unit and an unsaturated carboxylic acid unit, by heating, as in the production of the thermoplastic copolymer (C) of the present invention described above, The intramolecular cyclization reaction proceeds to produce a glutaric anhydride-containing unit represented by the general formula (1). Therefore, by mixing the multilayer structure polymer having a polymer containing an unsaturated carboxylic acid alkyl ester unit and an unsaturated carboxylic acid unit in the outermost layer with the thermoplastic copolymer (C), by heating at the time of melt kneading, A multilayer structure polymer containing the glutaric anhydride-containing unit represented by the general formula (1) in the outermost layer is obtained. Thereby, the multilayer structure polymer containing the glutaric anhydride-containing unit represented by the general formula (1) is well dispersed in the thermoplastic copolymer (C) serving as the continuous phase (matrix phase). Therefore, it is considered that the thermoplastic resin composition of the present invention can exhibit extremely high transparency as well as improved mechanical properties such as impact resistance.

  As a monomer used as the raw material of the unsaturated carboxylic acid alkyl ester unit here, an acrylic acid alkyl ester or a methacrylic acid alkyl ester is preferable, and methyl acrylate or methyl methacrylate is more preferably used.

  Moreover, as a monomer used as the raw material of an unsaturated carboxylic acid unit, acrylic acid or methacrylic acid is preferable, and methacrylic acid is more preferably used.

  As a preferable example of the multilayer structure polymer to be included in the thermoplastic resin composition of the present invention, the core layer is a butyl acrylate / styrene copolymer, and the outermost layer is represented by methyl methacrylate / general formula (1). In which the core layer is a butyl acrylate / styrene copolymer and the outermost layer is methyl methacrylate / glutaric anhydride represented by the general formula (1) Product containing unit / methacrylic acid copolymer, core layer is dimethylsiloxane / butyl acrylate copolymer and outermost layer is methyl methacrylate polymer, core layer is butadiene / styrene copolymer and outermost layer In which the core layer is a butyl acrylate polymer and the outermost layer is a methyl methacrylate polymer. Here, “/” indicates copolymerization. Furthermore, a preferable example is one in which either one or both of the rubber layer and the outermost layer is a polymer containing a glycidyl methacrylate unit. Among them, the core layer is a butyl acrylate / styrene polymer, the outermost layer is a copolymer composed of methyl methacrylate / glutaric anhydride-containing units represented by the general formula (1), and the core layer is an acrylic. A butyl acid / styrene copolymer whose outermost layer is methyl methacrylate / glutaric anhydride-containing unit represented by the general formula (1) / methacrylic acid polymer is a continuous phase (matrix phase). It becomes possible to approximate the refractive index with the thermoplastic copolymer (C) and to obtain a good dispersion state in the resin composition, and the transparency that can satisfy the demand for more advanced in recent years is expressed. Therefore, it can be preferably used.

  In the multilayer structure polymer of the present invention, the weight ratio of the core to the shell is preferably 50% by weight or more and 90% by weight or less, and more preferably 60% by weight or more, based on the whole multilayer structure polymer. 80% by weight or less is more preferable.

  The primary particle size of the multilayer polymer used in the present invention can be appropriately controlled by the particle size of the rubber used for the core layer and the amount of the thermoplastic polymer used for the shell layer.

  As the multilayer structure polymer of the present invention, a commercially available product that satisfies the above-described conditions may be used, or it may be prepared by a known method.

  As a commercial product of a multilayer structure polymer, for example, “Metablene (registered trademark)” manufactured by Mitsubishi Rayon Co., Ltd., “Kaneace (registered trademark)” manufactured by Kaneka Chemical Industry Co., Ltd. , “Acryloid (registered trademark)” manufactured by Rohm and Haas, “Staffroid (registered trademark)” manufactured by Gantz Kasei Kogyo, and “Parapet (registered trademark) SA” manufactured by Kuraray Co., Ltd. More than seeds can be used.

  Further, specific examples of the rubber-containing graft copolymer used as the rubber-containing polymer (D) of the present invention include an unsaturated carboxylic acid ester monomer, an unsaturated compound in the presence of the rubber polymer. Examples thereof include graft copolymers obtained by copolymerizing a monomer mixture comprising a carboxylic acid monomer, an aromatic vinyl monomer, and, if necessary, other vinyl monomers copolymerizable therewith.

  Diene rubber, acrylic rubber, ethylene rubber and the like can be used as the rubbery polymer used for the graft copolymer. Specific examples include polybutadiene, styrene-butadiene copolymer, block copolymer of styrene-butadiene, acrylonitrile-butadiene copolymer, butyl acrylate-butadiene copolymer, polyisoprene, butadiene-methyl methacrylate copolymer. , Butyl acrylate-methyl methacrylate copolymer, butadiene-ethyl acrylate copolymer, ethylene-propylene copolymer, ethylene-propylene-diene copolymer, ethylene-isoprene copolymer, and ethylene-methyl acrylate A copolymer etc. are mentioned. These rubbery polymers can be used alone or in a mixture of two or more.

  The graft copolymer in the present invention is a rubbery polymer in the presence of 10 to 80% by weight, preferably 20 to 70% by weight, more preferably 30 to 60% by weight. It is obtained by copolymerizing 90% by weight, preferably 30 to 80% by weight, more preferably 40 to 70% by weight. When the ratio of the rubbery polymer is less than the above range or exceeds the above range, the impact strength and the surface appearance may be lowered.

  The graft copolymer may contain an ungrafted copolymer that is produced when the monomer mixture is graft copolymerized with the rubbery polymer. From the viewpoint of impact strength, the graft ratio is preferably 10 to 100%. Here, the graft ratio is a weight ratio of the grafted monomer mixture to the rubbery polymer. Further, the intrinsic viscosity of the ungrafted copolymer measured at 30 ° C. is preferably 0.1 to 0.6 dl / g from the viewpoint of the balance between impact strength and moldability. .

  The intrinsic viscosity of the graft copolymer according to the present invention measured at 30 ° C. is not particularly limited, but 0.2 to 1.0 dl / g has a balance between impact strength and moldability. It is preferably used from the viewpoint, and more preferably 0.3 to 0.7 dl / g.

  There is no restriction | limiting in particular in the manufacturing method of the graft copolymer in this invention, It can obtain by well-known polymerization methods, such as block polymerization, solution polymerization, suspension polymerization, and emulsion polymerization.

  The primary particle size of the graft copolymer used in the present invention can be appropriately controlled by the particle size of the rubbery polymer and the amount of the monomer mixture to be graft copolymerized.

  Moreover, since the thermoplastic resin composition excellent in transparency can be obtained when each refractive index of a thermoplastic copolymer (C) and a rubber-containing polymer (D) is approximated, it is preferable. Specifically, the difference in refractive index between the two is preferably 0.05 or less, more preferably 0.02 or less, and particularly preferably 0.01 or less. In order to satisfy such a refractive index condition, a method for adjusting the composition ratio of each monomer unit of the thermoplastic copolymer (C) and / or a rubber material used for the rubber-containing polymer (D) Examples thereof include a method for preparing a polymer or monomer composition.

  In addition, the refractive index difference said here is the value measured by the method shown below. In the solvent in which the thermoplastic copolymer (C) is soluble, the thermoplastic resin composition of the present invention is sufficiently dissolved under appropriate conditions to obtain a cloudy solution. Separate into insoluble parts. After refining the soluble part (part containing the thermoplastic copolymer (C)) and the insoluble part (part containing the rubbery-containing polymer (D)), the measured refractive index (23 ° C., measurement wavelength: 550 nm) is defined as the difference in refractive index.

  In addition, the copolymer composition of the thermoplastic copolymer (C) and the rubber-containing polymer (D) in the resin composition is obtained by separating each component after the separation operation of the soluble component and the insoluble component with the solvent. Analyze individually.

  In the present invention, the weight ratio when blending the thermoplastic copolymer (C) and the rubbery-containing polymer (D) is preferably in the range of 99/1 to 50/50, and moreover 99/1. More preferably, it is in the range of ˜60 / 40, and most preferably in the range of 99/1 to 70/30.

When producing the thermoplastic resin composition of the present invention, a method is used in which the thermoplastic copolymer (C) and the rubber-containing polymer (D) are heated and melted and mixed under an appropriate shear field. In the present invention, the thermoplastic copolymer (C) and the rubber-containing polymer (D) can be heated and mixed by mixing the thermoplastic copolymer (C) and other optional components in advance, A method of uniformly kneading with a twin screw extruder is preferably used from the viewpoint of dispersibility and productivity.
In order to suppress agglomeration of the rubber-containing polymer particles in the thermoplastic resin composition to be produced, it is preferable to melt and knead so that the shearing force is not excessively applied at a relatively low temperature and a low rotational speed. Specifically, assuming that the resin temperature in the kneading zone is T, it is controlled within the range of (Tg of thermoplastic copolymer (C) + 100 ° C.) ≦ T ≦ (1% decomposition temperature of rubber-containing polymer (D)). Further, it is more preferable to control within the range of (Tg of the thermoplastic copolymer (C) + 120 ° C.) ≦ T ≦ (0.5% decomposition temperature of the rubber-containing polymer (D)). . Here, 1% decomposition temperature of the rubber-containing polymer (D) is 100 to 450 ° C. using a differential thermogravimetric simultaneous measurement apparatus (TG / DTA-200, manufactured by Seiko Denshi Kogyo Co., Ltd.) in nitrogen. This is the temperature when the weight reduction rate reaches 1% when the weight before heating is 100% by the heating test conducted in the temperature range of 20 ° C./min. When the resin temperature is lower than the range of the present invention, the melt viscosity becomes extremely high, and melt kneading becomes virtually impossible, which is not preferable. On the other hand, when the resin temperature is higher than the range of the present invention, re-aggregation and coloring of the rubber-containing polymer (D) become remarkable, which is not preferable.

  It was also found that by controlling the shear rate during melt-kneading to be low, aggregation of the rubber-containing polymer particles is suppressed as described above, and an extremely good color tone is obtained. That is, when the screw rotation speed during melt kneading is N (rpm), the melt-kneading is performed under the condition of N ≦ 150, so that the dispersibility of the rubber-containing polymer (D) remains good and the thermoplastic resin composition Since decomposition is suppressed, a significant color tone improving effect can be obtained, preferably 10 ≦ N ≦ 100, and more preferably 20 ≦ N ≦ 50. When the value of N exceeds 150, coloring due to decomposition and re-aggregation of the dispersed rubber-containing polymer (D) due to the action of shearing force and the accompanying heat generation is not preferable. On the other hand, when the value of N is smaller than 10, the shearing force is not sufficient, and the dispersion of the rubber-containing polymer (D) becomes insufficient, resulting in deterioration of surface smoothness, impact strength and heat resistance. Therefore, it is not preferable.

  In the present invention, the screw length in the melting zone and kneading zone of the extruder used for melt-kneading should not be too long compared to the screw diameter. Here, the melting zone refers to the area between the resin when the resin is supplied to the screw and reaches the first kneading zone, and the position where the resin is completely melted is the start point and the position of the discharge port is the end point. Define. The kneading zone is composed of a kneading disk and a reverse full flight disk, and is an area intended for kneading and staying of the resin. When the screw length in the melting zone is Lm, the screw length in the kneading zone is Lk, and the screw diameter is D, it is preferable that Lm / D ≦ 30 and Lk / D ≦ 5, Lm / D ≦ 25 and Lk /D≦4.5 is more preferable, and Lm / D ≦ 20 and Lk / D ≦ 4 are even more preferable. The lower limit is preferably Lm / D ≧ 10 and Lk / D ≧ 3 from the viewpoint of rubber dispersibility due to shear force. When the value of Lm / D exceeds 30 or the value of Lk / D exceeds 5, the shearing force becomes too strong, and coloring due to decomposition / reaggregation of the dispersed rubber-containing polymer (D) becomes significant, It is not preferable. On the other hand, when the value of Lm / D is less than 15 or the value of Lk / D is less than 3, the dispersion of the rubber-containing polymer (D) becomes insufficient, resulting in deterioration of surface smoothness, impact strength and heat resistance. Prone to cause. Moreover, it is preferable that there are two or more melting zones. In the case of one or none, it tends to cause a decrease in surface smoothness, impact strength and heat resistance.

  Further, the thermoplastic polymer and thermoplastic resin composition of the present invention are not limited to the purpose of the present invention, and other thermoplastic resins such as polyethylene, polypropylene, acrylic resin, polyamide, polyphenylene sulfide resin, polyether ether Further contains at least one selected from thermosetting resins such as ketone resins, polyesters, polysulfones, polyphenylene oxides, polyacetals, polyimides, polyetherimides, such as phenol resins, melamine resins, polyester resins, silicone resins, epoxy resins, etc. Can be made. In addition, hindered phenol, benzotriazole, benzophenone, benzoate, and cyanoacrylate UV absorbers and antioxidants, higher fatty acids, acid esters and acid amides, and higher alcohol and other lubricants and plasticizers , Montanic acid and its salts, its esters, its half esters, release agents such as stearyl alcohol, stearamide and ethylene wax, anti-coloring agents such as phosphites and hypophosphites, halogen flame retardants, phosphorus And additives such as coloring agents such as non-halogen flame retardants, nucleating agents, amines, sulfonic acids, and polyethers, pigments, dyes, and optical brighteners. May be. However, in light of the characteristics required by the application to be applied, it is preferable to add the additive within a range where the color of the additive does not adversely affect the thermoplastic polymer and the transparency is not lowered.

  The thermoplastic resin composition of the present invention is excellent in mechanical properties and molding processability, and can be melt-molded. Therefore, extrusion molding, injection molding, press molding, etc. are possible, and films, sheets, tubes, It can be used after being molded into a rod or other molded article having any desired shape and size.

  A well-known method can be used for the manufacturing method of the film which consists of a thermoplastic resin composition of this invention. That is, production methods such as an inflation method, a T-die method, a calendar method, a cutting method, a casting method, an emulsion method, and a hot press method can be used. Preferably, an inflation method, a T-die method, a cast method or a hot press method can be used. In the case of a production method using an inflation method or a T-die method, an extruder type melt extrusion apparatus equipped with a single screw or twin screw can be used. The melt extrusion temperature for producing the film of the present invention is preferably 150 to 350 ° C, more preferably 200 to 300 ° C. Moreover, when melt-kneading using a melt-extrusion apparatus, it is preferable to perform the melt-kneading under reduced pressure or the melt-kneading under nitrogen stream from a viewpoint of coloring suppression. When the film of the present invention is produced by the casting method, solvents such as tetrahydrofuran, acetone, methyl ethyl ketone, dimethylformamide, dimethyl sulfoxide, N-methylpyrrolidone can be used. Preferred solvents are acetone, methyl ethyl ketone, N-methylpyrrolidone and the like. The film is prepared by dissolving the thermoplastic resin composition of the present invention in one or more of the above solvents, and using the solution with a bar coater, a T die, a T die with a bar, a die coat, etc. It can be produced by casting on a flat plate or curved plate (roll) such as a film, steel belt, or metal foil and using a dry method in which the solvent is removed by evaporation, or a wet method in which the solution is solidified with a coagulating liquid.

  Specific uses of the molded article comprising the thermoplastic copolymer (C) and / or the thermoplastic resin composition produced according to the present invention include, for example, a housing for electrical equipment, a housing for OA equipment, various covers, and various gears. , Various cases, sensors, LED lamps, connectors, sockets, resistors, relay cases, switches, coil bobbins, capacitors, variable capacitor cases, optical pickups, oscillators, various terminal boards, transformers, plugs, printed wiring boards, tuners, speakers , Microphones, headphones, small motors, magnetic head bases, power modules, housings, semiconductors, liquid crystals, FDD carriages, FDD chassis, motor brush holders, parabolic antennas, computer-related parts and other electrical and electronic parts; VTR parts, Representative for Levi parts, irons, hair dryers, rice cooker parts, microwave oven parts, acoustic parts, audio equipment parts such as audio / laser discs / compact discs, lighting parts, refrigerator parts, air conditioner parts, typewriter parts, word processor parts, etc. Household, office electrical product parts, office computer related parts, telephone related parts, facsimile related parts, copier related parts, cleaning jigs, oilless bearings, stern bearings, underwater bearings, various bearings, motor parts, Machine-related parts such as lighters and typewriters, optical equipment such as microscopes, binoculars, cameras and watches, precision machine-related parts; alternator terminals, alternator connectors, IC regulators, various valves such as exhaust gas valves, fuel Relationship Exhaust / intake system pipes, air intake nozzle snorkel, intake manifold, fuel pump, engine coolant joint, carburetor main body, carburetor spacer, exhaust gas sensor, coolant sensor, oil temperature sensor, brake pad wear sensor, throttle position Sensor, crankshaft position sensor, air flow meter, thermostat base for air conditioner, heating hot air flow control valve, brush holder for radiator motor, water pump impeller, turbine vane, wiper motor related parts, dust distributor, starter switch, starter Relay, transmission wire harness, window washer nozzle, air conditioner panel switch PCB, fuel-related solenoid valve coil, fuse connector, horn terminal, electrical component insulation plate, step motor rotor, lamp socket, lamp reflector, lamp housing, brake piston, solenoid bobbin, engine oil filter, ignition device case, etc. It is done. In addition, because of its excellent transparency and heat resistance, it is used as a component for optical recording / communications, such as imaging equipment, such as cameras, VTRs, projection TVs, viewfinders, filters, prisms, and Fresnel lenses. Various optical equipment (VD, CD, DVD, MD, LD, etc.) substrates, various disc substrate protective films, optical disc player pickup lenses, optical fibers, optical switches, optical connectors, and other information equipment related parts such as liquid crystal displays, flat panel displays, plasmas Display light guide plate, Fresnel lens, polarizing plate, polarizing plate protective film, retardation film, light diffusion film, viewing angle widening film, reflective film, antireflection film, antiglare film, brightness enhancement film, prism sheet, pickup lens , Light guide films for touch panels, covers, etc., as parts related to transportation equipment such as automobiles, tail lamp lenses, head lamp lenses, inner lenses, amber caps, reflectors, extensions, side mirrors, room mirrors, side visors, instrument needles, instrument covers , Glazing typified by window glass, etc. as medical equipment related parts, spectacle lenses, spectacle frames, contact lenses, endoscopes, optical cells for analysis, etc., as building material related parts, lighting windows, road translucent plates, lighting covers It can also be applied to signboards, translucent sound insulation walls, bathtub materials, etc., and is extremely useful for these various applications.

  EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to these examples. In addition, the polymerization apparatus, each measurement, and evaluation were performed by the following method.

[Continuous polymerization equipment]
The carboxyl group-containing acrylic copolymer (A) and copolymer solution (a) obtained in this example were obtained by an apparatus arranged as shown in FIG. The mixed solution containing the monomer and the solvent is sent to the circulation polymerization line (I) by the plunger pump (1). Circulation polymerization line (I) has a 2.5-inch inner diameter tubular reactor in order from the inlet (30 built-in SMX type static mixer and 30 static mixing structures manufactured by Gebrüter Sulzer, Switzerland), (2), (3) And (4) and a gear pump (5) for circulating the mixed solution. A non-circulating polymerization line (II) is connected between the tubular reactor (4) and the gear pump (5). The tubular reactors (7), (8) and (9) are the same as described above in order from the inlet. The gear pump (10) is directly connected. A side line (6) is connected between the circulation polymerization line (I) and the non-circulation polymerization line (main polymerization line, II).

[Each measurement method and evaluation]
(1) Polymer content (solid content) (wt%)
5 g of the copolymer solution (a) obtained in the polymerization step is dissolved in 50 g of tetrahydrofuran, reprecipitated in 500 g of hexane, filtered, and then vacuum-dried at 140 ° C. for 1 hour to obtain a carboxyl group-containing acrylic copolymer ( A) white powder was obtained. The weight of the obtained carboxyl group-containing acrylic copolymer (A) was measured, and the polymer content in the copolymer solution (a) was calculated from the following formula.
Polymer content (% by weight) = {(A1-S0) / S0} × 100
Each symbol indicates the following numerical value.
A1 = weight (g) of the carboxyl group-containing acrylic copolymer (A) after drying
S0 = weight of copolymer solution (a) (g)

(2) Polymerization rate (φ)
The unreacted monomer concentration (% by weight) in the copolymer solution (a) and the charged raw material solution was quantified by gas chromatography, and calculated from the following formula.
Polymerization rate (φ) = 100 × (1−M1 / M0)
Each symbol indicates the following numerical value.
M1 = Unreacted monomer concentration (% by weight) in the copolymer solution (a)
M0 = monomer concentration in the charged raw material solution (wt%)

(3) Content of Volatile Component 1 g each of the carboxyl group-containing acrylic copolymer (A) before introduction into the cyclization step and the cyclized thermoplastic copolymer (C) were dissolved in 20 g of tetrahydrofuran, and gas chromatograph was used. The remaining unreacted monomer and / or organic solvent (B) was quantified, and the content of volatile components was calculated from the following formula.
Volatile component content (% by weight) = {(α + β) / P1} × 100
Each symbol indicates the following numerical value.
α = weight of residual monomer determined by gas chromatograph (g)
β = weight of organic solvent (B) determined from gas chromatograph (g)
P1 = weight (g) of sampled carboxyl group-containing acrylic copolymer (A) or thermoplastic copolymer (C)

(4) Weight average molecular weight / molecular weight distribution 10 mg of the obtained carboxyl group-containing acrylic copolymer (A) and thermoplastic copolymer (C) were dissolved in 2 g of tetrahydrofuran to prepare a measurement sample. Gel permeation chromatograph equipped with a DAWN-DSP type multi-angle light scattering photometer (manufactured by Wyatt Technology) using tetrahydrofuran as a solvent (pump: model 515, manufactured by Waters, column: TSK-gel-GMHXL, manufactured by Tosoh Corporation) ) Was used to measure the weight average molecular weight (absolute molecular weight) and the number average molecular weight (absolute molecular weight). The molecular weight distribution was calculated by weight average molecular weight (absolute molecular weight) / number average molecular weight (absolute molecular weight).

(5) Composition analysis of each component ¹ H-NMR was measured at 30 ° C. in deuterated dimethyl sulfoxide to determine the composition of each copolymer unit.

(6) Glass transition temperature (Tg)
Using a differential scanning calorimeter (DSC-7 manufactured by Perkin Elmer), the measurement was performed at a temperature increase rate of 20 ° C./min in a nitrogen atmosphere.

(7) Transparency (total light transmittance, haze)
The obtained thermoplastic copolymer was injection molded at a glass transition temperature + 140 ° C., and the total light transmittance (%) at 23 ° C. of the obtained 1 mm-thick molded product was measured using a direct reading haze meter manufactured by Toyo Seiki Co., Ltd. And measured to evaluate transparency.

(8) Yellowness Index
The obtained thermoplastic copolymer was injection molded at a glass transition temperature of + 140 ° C., and the YI value of the obtained 1 mm-thick molded product was measured using an SM color computer (manufactured by Suga Test Instruments Co., Ltd.) according to JIS-K7103. did.

(9) Number of foreign substances The obtained thermoplastic copolymer pellets were dissolved in methyl ethyl ketone at a concentration of 25% by weight at room temperature with stirring for 24 hours, and the obtained thermoplastic copolymer solution was cast into a glass plate shape. Thereafter, a drying process was performed at 50 ° C. for 20 minutes, and then at 80 ° C. for 30 minutes, thereby forming a film having a thickness of 100 ± 5 μm. This film was observed with an optical microscope, and the number of foreign matters of 20 μm or more per 1 mm square unit area was counted. This was observed at 10 points at random per sample and the count of the number of foreign matters was repeated, and the average value was evaluated as the number of foreign matters per 1 mm square unit area (pieces / mm ² ).

(10) Gas generation amount during residence 5 g of the obtained thermoplastic copolymer (C) pellets were pre-dried at 80 ° C. for 12 hours and heat-treated for 30 minutes in a heating furnace adjusted to a glass transition temperature of + 130 ° C. The weight before and after was measured, and the weight reduction rate calculated by the following equation was evaluated as the amount of gas generated during residence.
Weight reduction rate (% by weight) = {(W0−W1) / W0} × 100
Each symbol indicates the following numerical value.
W0 = weight of thermoplastic copolymer (C) before heat treatment (g)
W1 = weight (g) of thermoplastic copolymer (C) after heat treatment

(11) Melt viscosity of thermoplastic copolymer (C) The obtained thermoplastic copolymer (C) pellets were pre-dried at 80 ° C. for 12 hours, and Capillograph 1C type (die diameter φ1 mm, die length 5 mm, manufactured by Toyo Seiki Co., Ltd.) ) At a glass transition temperature of + 130 ° C. and a shear rate of 12 / sec.

(A) Production of carboxyl group-containing acrylic carboxyl group-containing acrylic copolymer (A) and copolymer solution (a) [Example 1: (A-1): continuous bulk polymerization method]
Using the continuous polymerization apparatus shown in FIG. 1, a monomer mixture having the following formulation is continuously supplied from the plunger pump (1) at a rate of 6 kg / h, and further, non-circular polymerization is performed from the circulation polymerization line (I). 5 parts by weight of a methyl methacrylate solution in which 0.001 part by weight of 1,1-di-t-butylperoxycyclohexane is dissolved from the side line (6) at the position of the connecting part toward the line (main polymerization line, II) (0.3 kg / h) was added to carry out continuous polymerization. At this time, the polymerization temperature of the circulation polymerization line (I) was 130 ° C., the polymerization temperature of the non-circulation polymerization line was 150 ° C., and the reflux ratio (R = F1 / F2) was 6. The polymerization rate of the polymerization solution obtained in the polymerization step was 80%, and the carboxyl group-containing acrylic copolymer (A) content, that is, the solid content was also 80% by weight. Moreover, it was 1200 Pa * s as a result of measuring the solution viscosity of the copolymer solution (a) at 30 degreeC. 10 g of the obtained copolymer solution (a) was dissolved in 40 g of tetrahydrofuran and reprecipitated in 500 mL of hexane to obtain a powdery copolymer (A-1). This copolymer (A-1) had a weight average molecular weight of 85,000.
Methacrylic acid 25 parts by weight Methyl methacrylate 75 parts by weight 1,1-di-t-butylperoxycyclohexane 0.01 part by weight n-dodecyl mercaptan 0.8 part by weight.

[Examples 2 to 4: (A-2) to (A-4): continuous bulk polymerization method]
Except having changed the raw material into the monomer mixture shown in Table 1, copolymers (A-2) to (A-4) were obtained by the same production method as (A-1). The properties of the obtained copolymer solution (a) and copolymers (A-2) to (A-4) are shown in Tables 1 and 2.

[Examples 5 to 11: (A-5) to (A-11): Continuous solution polymerization method]
Copolymers (A-5) to (A-11) in the same production method as (A-1) except that methyl ethyl ketone was used as the organic solvent (B) and the monomer mixture shown in Table 1 was changed. Got. The properties of the obtained copolymer solution (a) and copolymers (A-5) to (A-11) are shown in Tables 1 and 2.

[Comparative Example 1: (A-12): Suspension polymerization method]
In a stainless steel autoclave having a capacity of 20 liters and equipped with a baffle and a foudra type stirring blade, a methyl methacrylate / acrylamide copolymer suspension (prepared by the following method: 20 parts by weight of methyl methacrylate, 80 parts by weight of acrylamide) Then, 0.3 parts by weight of potassium persulfate and 1500 parts by weight of ion-exchanged water are charged into the reactor, and the reactor is replaced with nitrogen gas and maintained at 70 ° C. The reaction completely converts the monomer into a polymer. Then, a solution obtained by dissolving 2.5 g of the obtained aqueous solution as a suspending agent in 8250 g of ion-exchanged water is supplied and stirred at 400 rpm. The system was replaced with nitrogen gas. Next, a total of 5000 g of the following monomer mixture was added while stirring the reaction system, and the temperature was raised to 70 ° C. The time when the internal temperature reached 70 ° C. was set as the start of polymerization, and kept for 180 minutes to complete the polymerization. Thereafter, the reaction system was cooled, the polymer was separated, washed and dried according to the usual method to obtain a bead-shaped copolymer (A-12). The polymerization rate of this copolymer (A-12) was 98%, and the weight average molecular weight was 130,000.
Methacrylic acid 27 parts by weight Methyl methacrylate 73 parts by weight n-dodecyl mercaptan 0.8 parts by weight Lauroyl peroxide 0.3 parts by weight.

[Comparative Example 2: (A-13): Continuous solution polymerization method]
A copolymer (A-13) was obtained by the production method disclosed in Patent Document 2 and Example 7. The characteristics of the obtained copolymer solution (a) and copolymer (A-13) are shown in Tables 1 and 2.

[Comparative Example 3: (A-14): Continuous solution polymerization method]
A copolymer (A-14) was obtained by the production method disclosed in Patent Document 3 and Example 2. The characteristics of the obtained copolymer solution (a) and copolymer (A-14) are shown in Tables 1 and 2.

[Comparative Example 4: (A-15): Continuous solution polymerization method]
A copolymer (A-15) was obtained by the production method disclosed in Patent Document 4 and Example 17. The characteristics of the obtained copolymer solution (a) and copolymer (A-15) are shown in Tables 1 and 2.

  Tables 1 and 2 show the respective component compositions and copolymerization results of the carboxyl group-containing acrylic carboxyl group-containing acrylic copolymer (A) obtained in the reference example.

(A) Production of thermoplastic copolymer (C) (devolatilization step, cyclization step)
[Examples 12 to 22: (C-1) to (C-11)]
The copolymer solution (a) containing the copolymers (A-1) to (A-11) obtained in Examples 1 to 6 was subjected to a 44 mmφ twin-screw extruder (TEX-44 (manufactured by Nippon Steel Works) by a gear pump. , L / D = 28.0, vent part: 3 places) at a feed rate of 5.0 kg / h, while purging nitrogen from the hopper part at a rate of 10 L / min, screw rotation speed 75 rpm, cylinder temperature Volatilization was performed at a pressure of 20 Torr by depressurizing from a vent part at 250 ° C. At this time, the carboxylic component-containing acrylic carboxyl group-containing acrylic copolymer (A) after devolatilization was sampled, and the volatile components contained therein were sampled. Subsequently, it was supplied to a 38 mmφ biaxial / uniaxial composite continuous kneading extruder (HTM38 (manufactured by CTE, L / D = 47.5, vent part: 2 places). Nitrogen from the hopper part was 10 L / In minutes While purging, an intramolecular cyclization reaction was performed at a screw rotation speed of 75 rpm, a raw material supply rate of 5.0 kg / h, and a cylinder temperature of 300 ° C., and the pellet-shaped thermoplastic copolymer (C) ((C-1) to ( C-11)) was obtained.

[Comparative Example 5: (C-12)]
The copolymer (A-12) beads obtained in Comparative Example 1 were used in a 38 mmφ biaxial / uniaxial composite continuous kneading extruder (HTM38 (manufactured by CTE, L / D = 47.5, vent portion: 2 locations). While purging nitrogen from the hopper at an amount of 10 L / min, an intramolecular cyclization reaction was performed under the cylinder temperature conditions shown in Table 1 at a screw rotation speed of 75 rpm and a raw material supply rate of 10 kg / h, respectively. A pellet-like glutaric anhydride-containing thermoplastic copolymer (C-7) was obtained.

[Comparative Example 6: (C-13)]
According to the method disclosed in Patent Document 3 and Example 7, the copolymer solution (a) containing the copolymer (A-13) obtained in Comparative Example 2 was supplied to a high-temperature vacuum chamber heated to 250 ° C. The devolatilization and cyclization reaction was performed for 60 minutes at a pressure of 50 Torr, and the bulk product was pulverized to obtain a thermoplastic copolymer (C-13).

[Comparative Example 7: (C-14)]
According to the method disclosed in Patent Document 4, the copolymer solution (a) containing the copolymer (A-14) obtained in Comparative Example 3 is supplied to a devolatilization tank heated to 260 ° C., for 30 minutes. Volatilization and cyclization were performed at a pressure of 20 Torr to obtain a pellet-shaped thermoplastic copolymer (C-14).

[Comparative Example 8: (C-15)]
According to the method disclosed in Patent Document 4 and Example 17, the copolymer solution (a) containing the copolymer (A-10) obtained in Comparative Example 4 was supplied to a devolatilization tank heated to 260 ° C. The devolatilization and cyclization reaction was performed for 30 minutes at a pressure of 20 Torr to obtain a pellet-shaped thermoplastic copolymer (C-15).

Next, the pellets were dried at 100 ° C. for 8 hours, and each copolymer component composition and various characteristics evaluation results determined by ¹ H-NMR are shown in Tables 3 and 4.

  From Examples 1-22 and Comparative Examples 1-8, the production method of the present invention performs bulk polymerization or solution polymerization under specific polymerization conditions in the polymerization step, and further removes unreacted monomers from the obtained polymerization solution. After removing the devolatilization, by carrying out the cyclization reaction under specific conditions, while having high heat resistance and thermal stability with a small amount of gas generated even during residence, it is excellent in colorless transparency, It turns out that few thermoplastic copolymers (C) can be manufactured.

  On the other hand, when the polymerization is carried out by a method outside the scope of the present invention, it can be seen that the color tone of the thermoplastic copolymer after the heat treatment and the number of foreign matters are inferior under any other conditions.

[Example 23]: Production example by continuous process <Polymerization step>
Using the continuous polymerization apparatus shown in FIG. 1, a monomer mixture having the following formulation is continuously supplied from the plunger pump (1) at a rate of 6 kg / h, and further, non-circular polymerization is performed from the circulation polymerization line (I). 5 parts by weight of a methyl methacrylate solution in which 0.001 part by weight of 1,1-di-t-butylperoxycyclohexane is dissolved from the side line (6) at the position of the connecting part toward the line (main polymerization line, II) (0.3 kg / h) was added to carry out continuous polymerization. At this time, the polymerization temperature of the circulation polymerization line (I) was 130 ° C., the polymerization temperature of the non-circulation polymerization line was 150 ° C., and the reflux ratio (R = F1 / F2) was 6. The polymerization rate of the polymerization solution obtained in the polymerization step was 80%, and the carboxyl group-containing acrylic copolymer (A) content, that is, the solid content was also 80% by weight. Moreover, it was 1200 Pa * s as a result of measuring the solution viscosity of the copolymer solution (a) at 30 degreeC. 10 g of the obtained copolymer solution (a) was dissolved in 40 g of tetrahydrofuran and reprecipitated in 500 mL of hexane to obtain a powdery copolymer (A-1). This copolymer (A-1) had a weight average molecular weight of 85,000.
Methacrylic acid 30 parts by weight Methyl methacrylate 70 parts by weight 1,1-di-t-butylperoxycyclohexane 0.01 parts by weight n-dodecyl mercaptan 0.6 parts by weight

<Devolatile process>
Subsequently, the copolymer solution (a) obtained in the polymerization step was subjected to a 44 mmφ twin screw extruder (TEX-44 (manufactured by Nippon Steel Works, L / D = 45.0, back vent part: 1) using a gear pump. , Depressurization treatment at a pressure of 20 Torr, with a screw rotation speed of 75 rpm and a cylinder temperature of 150 ° C. At this point, the carboxylic component-containing acrylic carboxyl group-containing acrylic copolymer (A) after devolatilization was sampled and the volatile components contained were measured.

<Cyclization process>
Subsequently, the carboxyl group-containing acrylic carboxyl group-containing acrylic copolymer (A) obtained in the devolatilization step is driven by a gear pump, and the glasses blade is turned into a horizontal biaxial agitator (“Hitachi Glasses Blade Polymerizer (trade name) manufactured by Hitachi, Ltd.). ”, Capacity 24L, vent part: 1 place), continuously fed at a feed rate of 3.8 kg / h, screw rotation speed 10 rpm, cylinder temperature 300 ° C., decompression from the vent part, and cyclization reaction at pressure 10 Torr And pelletized with a strand cutter to produce a thermoplastic copolymer (C-16) at a rate of 3.6 kg / h. The average residence time of the cyclizer at this time was 60 minutes.

  The obtained pellets of (C-16) are dried at 100 ° C. for 8 hours, and each copolymer component composition and various characteristics evaluation results determined by 1H-NMR are shown in Table 5.

<Volatile component recovery step>: Recovery of unreacted monomer and organic solvent (B) The vent portion of the twin screw extruder in the pre-devolatilization step is connected to a cooler, and volatile components are recovered at 4.2 kg / h. did. Subsequently, the obtained recovered liquid was supplied to a distillation column and distilled under reduced pressure at 90 ° C. and 400 Torr, and the recovered liquid was continuously purified to obtain 97% as a recovered raw material. The obtained recovered raw material was recycled as a raw material mixture in the polymerization step.

[Example 24]: Production example by continuous process <Polymerization step>
Using the continuous polymerization apparatus shown in FIG. 1, a monomer mixture having the following formulation is continuously supplied from the plunger pump (1) at a rate of 6 kg / h, and further, non-circular polymerization is performed from the circulation polymerization line (I). 5 parts by weight of a methyl methacrylate solution in which 0.001 part by weight of 1,1-di-t-butylperoxycyclohexane is dissolved from the side line (6) at the position of the connecting part toward the line (main polymerization line, II) (0.3 kg / h) was added to carry out continuous polymerization. At this time, the polymerization temperature of the circulation polymerization line (I) was 130 ° C., the polymerization temperature of the non-circulation polymerization line was 150 ° C., and the reflux ratio (R = F1 / F2) was 6. The polymerization rate of the polymerization solution obtained in the polymerization step was 80%, and the carboxyl group-containing acrylic copolymer (A) content, that is, the solid content was also 80% by weight. Moreover, it was 1200 Pa * s as a result of measuring the solution viscosity of the copolymer solution (a) at 30 degreeC. 10 g of the obtained copolymer solution (a) was dissolved in 40 g of tetrahydrofuran and reprecipitated in 500 mL of hexane to obtain a powdery copolymer (A-1). This copolymer (A-1) had a weight average molecular weight of 85,000.
Methacrylic acid 20 parts by weight Methyl methacrylate 80 parts by weight 1,1-di-t-butylperoxycyclohexane 0.01 parts by weight n-dodecyl mercaptan 0.6 parts by weight

<Devolatile process>
Subsequently, the copolymer solution (a) obtained in the polymerization step was subjected to a 44 mmφ twin screw extruder (TEX-44 (manufactured by Nippon Steel Works, L / D = 45.0, back vent part: 1) using a gear pump. , Depressurization treatment at a pressure of 20 Torr, with a screw rotation speed of 75 rpm and a cylinder temperature of 150 ° C. At this point, the carboxylic component-containing acrylic carboxyl group-containing acrylic copolymer (A) after devolatilization was sampled and the volatile components contained were measured.

<Cyclization process>
Subsequently, the carboxyl group-containing acrylic carboxyl group-containing acrylic copolymer (A) obtained in the devolatilization step is driven by a gear pump, and the glasses blade is turned into a horizontal biaxial agitator (“Hitachi Glasses Blade Polymerizer (trade name) manufactured by Hitachi, Ltd.). ”, Capacity 24L, vent part: 1 place), continuously fed at a feed rate of 3.8 kg / h, screw rotation speed 10 rpm, cylinder temperature 300 ° C., decompression from the vent part, and cyclization reaction at pressure 10 Torr And pelletized with a strand cutter to produce a thermoplastic copolymer (C-17) at a rate of 3.6 kg / h. The average residence time of the cyclizer at this time was 60 minutes.

  The obtained pellets of (C-17) are dried at 100 ° C. for 8 hours, and each copolymer component composition and various characteristics evaluation results determined by 1H-NMR are shown in Table 5.

<Volatile component recovery step>: Recovery of unreacted monomer and organic solvent (B) The vent portion of the twin screw extruder in the pre-devolatilization step is connected to a cooler, and volatile components are recovered at 4.2 kg / h. did. Subsequently, the obtained recovered liquid was supplied to a distillation column and distilled under reduced pressure at 90 ° C. and 400 Torr, and the recovered liquid was continuously purified to obtain 97% as a recovered raw material. The obtained recovered raw material was recycled as a raw material mixture in the polymerization step.

[Examples 25 to 37, Comparative Examples 9 to 12]: Production of thermoplastic resin composition (1) Reference example: Production of rubber-containing polymer (D) In a glass container with a cooler (capacity 5 liters) Charge 120 parts by weight of deionized water, 0.5 parts by weight of potassium carbonate, 0.5 parts by weight of dioctyl sulfosuccinate, 0.005 parts by weight of potassium persulfate, and stir in a nitrogen atmosphere. Then, 53 parts by weight of butyl acrylate, styrene 17 parts by weight and 1 part by weight of allyl methacrylate (crosslinking agent) were charged. These mixtures were reacted at 70 ° C. for 30 minutes to obtain a core layer polymer. Next, a mixture of 21 parts by weight of methyl methacrylate, 9 parts by weight of methacrylic acid, and 0.005 parts by weight of potassium persulfate was continuously added over 90 minutes, and the mixture was further maintained for 90 minutes to polymerize the shell layer. This polymer latex was coagulated with sulfuric acid, neutralized with caustic soda, washed, filtered and dried to obtain a rubber-containing polymer (D) having a two-layer structure. The number average particle diameter of the polymer particles measured with an electron microscope was 155 nm.

(2) Production of thermoplastic resin composition The thermoplastic copolymers (C) obtained in Examples 12 to 24 and Comparative Examples 5 to 8 and the rubbery polymer (D) obtained in Reference Examples were used. Blended with the composition shown in Table 6 and kneaded using a twin-screw extruder (TEX30 (manufactured by Nippon Steel Co., Ltd., L / D = 44.5)) at a cylinder temperature of 280 ° C. and a screw rotation speed of 100 rpm, pelletized heat Next, the obtained pellet-shaped thermoplastic resin composition was subjected to an injection molding machine (SG75H-MIV manufactured by Sumitomo Heavy Industries, Ltd.) to mold each test piece. Molding temperature: (Glass transition temperature of thermoplastic copolymer (C) +150) ° C., mold temperature: 80 ° C., injection time: 5 seconds, cooling time: 10 seconds, molding pressure: all molds are filled with resin Pressure (molding lower limit pressure) +1 MPa.
Table 6 shows the evaluation results of the obtained thermoplastic resin composition.

  From comparison of Examples 25 to 37 and Comparative Examples 9 to 12, the thermoplastic resin composition of the present invention contains the thermoplastic copolymer (C) obtained in Examples 12 to 24. It can be seen that the weight loss during residence can be suppressed, and the thermal stability is excellent. That is, it can be seen that the thermoplastic resin composition of the present invention is excellent in high transparency, heat resistance, and toughness, and particularly excellent in thermal stability and color tone. On the other hand, it can be seen that the thermoplastic resin composition outside the scope of the present invention is inferior in terms of color tone and loss on heating.

It is process drawing which shows one example of the continuous polymerization line of the continuous polymerization apparatus incorporating the tubular reactor which has the structure part for static mixing of this invention. It is a schematic process drawing which shows an example of the manufacturing method of the thermoplastic copolymer of this invention. It is a schematic process drawing which shows the other example of the manufacturing method of the thermoplastic copolymer of this invention. It is a schematic process drawing which shows the other example of the manufacturing method of the thermoplastic copolymer of this invention. It is a schematic process drawing which shows the other example of the manufacturing method of the thermoplastic copolymer of this invention. It is a schematic process drawing which shows the other example of the manufacturing method of the thermoplastic copolymer of this invention.

Explanation of symbols

(I): Circulation line (II): Main polymerization line (non-circulation polymerization line)
1: a plunger pump 2: a tubular reactor having a structure for static mixing 3: a tubular reactor having a structure for static mixing 4: a tubular reactor having a structure for static mixing 5: a gear pump 6: a side line 7: Tubular reactor having a static mixing structure 8: Tubular reactor having a static mixing structure 9: Tubular reactor having a static mixing structure 10: Gear pump 11: Carboxyl group-containing acrylic copolymer Copolymer solution containing coalesce (a)
12: polymerization apparatus 13: devolatilization apparatus 13-1: devolatilization apparatus in pre-devolatilization process 13-2: devolatilization apparatus in post-devolatilization process 14: cyclization apparatus 15: cooling apparatus 16: purification apparatus 17: thermoplastic Copolymer (C)

Claims (13)

Using a continuous tubular reactor having a structure for static mixing therein, a carboxyl group-containing acrylic copolymer (A) containing (i) an unsaturated carboxylic acid alkyl ester unit and (ii) an unsaturated carboxylic acid unit When producing, a raw material mixture comprising an unsaturated carboxylic acid alkyl ester monomer and an unsaturated carboxylic acid monomer mixture, a chain transfer agent, and a radical polymerization initiator, A recirculation line (I) for initial polymerization incorporating one or more tubular reactors having an interior thereof, and one or more continuing from this recirculation line (I) and having a static mixing structure therein To a continuous reactor having a non-circulating main polymerization line (II) incorporating a tubular reactor, and passing the reaction solution while polymerizing it, and carbocycle at the outlet of the main polymerization line (II). Polymerization is carried out so that the content of the syl group-containing acrylic copolymer (A) is 50 to 90% by weight, and a copolymer solution comprising a carboxyl group-containing acrylic copolymer (A) and an unreacted raw material mixture (a A process for producing a carboxyl group-containing acrylic copolymer (A), characterized in that The organic solvent (B) for dissolving the carboxyl group-containing acrylic copolymer (A) in the raw material mixture is added in an amount of 1 to 200 parts by weight with respect to 100 parts by weight of the monomer and continuously polymerized. Item 2. A method for producing a carboxyl group-containing acrylic copolymer (A) according to Item 1. The method for producing a carboxyl group-containing acrylic copolymer (A) according to claim 2, wherein the organic solvent (B) is at least one selected from ketones, ether compounds and alcohols. The monomer mixture is composed of 100% by weight of the total monomer mixture, 5 to 50% by weight of unsaturated carboxylic acid, 50 to 95% by weight of unsaturated carboxylic acid alkyl ester, and other copolymerizable monomers. The process for producing a thermoplastic copolymer according to any one of claims 1 to 3, comprising 0 to 15% by weight of the component. 5. The carboxyl group-containing acrylic copolymer according to claim 1, wherein the addition amount of the chain transfer agent is 0.1 to 2.0 parts by weight with respect to 100 parts by weight of the monomer mixture. Manufacturing method of union (A). The method for producing a carboxyl group-containing acrylic copolymer (A) according to any one of claims 1 to 5, wherein the chain transfer agent is a mercaptan compound. The carboxyl group-containing group according to any one of claims 1 to 6, wherein the radical polymerization initiator has a half-life of 0.01 to 60 minutes at each polymerization temperature of the circulation line (I) and the non-circulation line (II). The manufacturing method of an acrylic copolymer (A). The polymerization temperature in the said circulation line (I) is 110-140 degreeC, The manufacturing method of the carboxyl group-containing acrylic copolymer (A) in any one of Claims 1-6 characterized by the above-mentioned. The carboxyl group-containing acrylic copolymer according to any one of claims 1 to 8, wherein the polymerization temperature in the non-circulation line (II) is not lower than the polymerization temperature of the circulation line (I) and not higher than 200 ° C. Manufacturing method of union (A). Subsequently to the main polymerization line (II) (devolatilization step), the copolymer solution (a) is supplied to the continuous devolatilizer, and the unreacted monomer or the unreacted monomer and the organic solvent (B) The method for producing a carboxyl group-containing acrylic copolymer (A) according to any one of claims 1 to 9, wherein the mixture is separated and removed. The unreacted monomer separated or removed in the devolatilization step or a mixture of the unreacted monomer and the organic solvent (B) is recycled to the prepolymerization step. The manufacturing method of an acrylic copolymer (A). Intramolecular cyclization by heat-treating the carboxyl group-containing acrylic copolymer (A) obtained by the production method according to claim 1, and (a) dehydration and / or (b) dealcoholization reaction. (Iii) A method for producing a thermoplastic copolymer (C) comprising (iii) a glutaric anhydride unit represented by the following general formula (1) and (i) an unsaturated carboxylic acid alkyl ester unit.

(However, R ¹ and R ² are the same or different and represent any one selected from a hydrogen atom and an alkyl group having 1 to 5 carbon atoms.) The manufacturing method of the thermoplastic resin composition which mix | blends a rubber-containing polymer (D) further with the thermoplastic copolymer (C) obtained by the method of Claim 12.

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