JP2009191248A - Thermoplastic resin composition, and resin molded article and polarizer protective film made by using the same, and method for producing resin molded article - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thermoplastic resin composition suppressed in occurrence of bleedout, etc., and having less problem development caused by the volatilization of an ultraviolet light absorber (UVA) on its high temperature-molding. <P>SOLUTION: This thermoplastic resin composition is provided by containing a 100 pts.wt. thermoplastic resin consisting mainly of an acrylic resin having a prescribed ring structure in its main chain and a 0.1 to 5 pts.wt. UVA having a structure expressed by formula (3), and having a ≥110°C glass transition temperature. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a thermoplastic resin composition suitable as a heat-resistant transparent material, a resin molded product comprising the composition, and a polarizer protective film as a specific example of the resin molded product. Moreover, this invention relates to the polarizing plate provided with the said protective film, an image display apparatus provided with the said polarizing plate, and also relates to the manufacturing method of a resin molded product.

  An acrylic resin typified by polymethyl methacrylate (PMMA) has excellent optical properties such as high light transmittance, and is excellent in the balance of mechanical strength, molding processability and surface hardness. Widely used as a transparent material in various industrial products such as home appliances. In recent years, the use of optical members such as optical members used in image display devices has increased.

  Acrylic resins may turn yellow when exposed to light containing ultraviolet rays, resulting in a decrease in transparency. As a method for preventing this, a method of adding an ultraviolet absorber (UVA) is known. However, the molecular weight of UVA is generally small, and foaming may occur or UVA may bleed out when a resin composition containing an acrylic resin and UVA is molded. In addition, UVA may evaporate due to heat applied at the time of molding, resulting in a problem that the ultraviolet absorption ability of the obtained resin molded product is lowered or the molding apparatus is contaminated by the evaporated UVA.

  By the way, as an acrylic resin having both transparency and heat resistance, a resin having a ring structure in the main chain is known. A resin having a ring structure in the main chain has a higher glass transition temperature (Tg) than a resin having no ring structure in the main chain. For example, it is easy to dispose a resin near a heat generating part such as a light source in an image display device. It has various practical advantages such as. For example, Patent Document 1 discloses an acrylic resin having an N-substituted maleimide structure in the main chain as a ring structure, and Patent Document 2 discloses an acrylic resin having a glutarimide structure in the main chain as a ring structure. It is disclosed.

  As the Tg of the resin or resin composition increases, a higher molding temperature is required. For this reason, when UVA is added to an acrylic resin having a ring structure in the main chain, foaming and bleed-out are likely to occur in the obtained resin molded product. In addition, UVA transpiration during molding is likely to decrease, resulting in a decrease in ultraviolet absorption capacity and contamination of the molding apparatus.

  Considering these problems, triazine compounds, benzotriazole compounds, and benzophenone compounds, which are considered to have a high ultraviolet absorption effect with a small amount of addition, have been used in combination with acrylic resins as UVA. Yes. The above-mentioned compound is also disclosed in Patent Document 2 described above.

However, these compounds have a problem in compatibility with acrylic resins having a ring structure in the main chain. Suppression of foaming and bleeding out during molding at high temperatures is not always sufficient, and further improvement is desired. In addition, when forming an optical member from a resin composition containing an acrylic resin and UVA, the resin composition may be filtered with a polymer filter for the purpose of reducing defects in appearance of the obtained member. In this case, it is necessary to further increase the molding temperature of the resin composition. When the molding temperature becomes high, foaming and bleed-out are likely to occur, and problems associated with UVA transpiration (decrease in ultraviolet absorption ability in the obtained resin molded product, contamination of the molding apparatus due to transpiration UVA) are likely to occur. .
JP 2007-31537 A JP 2006-328334 A

  The present invention is a thermoplastic resin composition containing an acrylic resin having a ring structure in the main chain and UVA, and has excellent heat resistance based on the high glass transition temperature, and at the time of molding at a high temperature. The purpose of the present invention is to provide a resin composition in which the occurrence of bleeding out and the like is suppressed and the occurrence of problems due to UVA transpiration can be reduced.

  The thermoplastic resin composition of the present invention is a thermoplastic resin mainly composed of an acrylic resin (resin (A)) having a ring structure represented by the following formula (1) and / or formula (2) in the main chain. Including 100 parts by weight and 0.1 to 5 parts by weight of an ultraviolet absorber (UVA (B)) having a structure represented by the following formula (3), the glass transition temperature is 110 ° C. or higher.

In the above formula (1), R ¹ and R ² are each independently a hydrogen atom or a methyl group, and X ¹ is an oxygen atom or a nitrogen atom. When X ¹ is an oxygen atom, R ³ does not exist, and when X ¹ is a nitrogen atom, R ³ is a hydrogen atom, a linear alkyl group having 1 to 6 carbon atoms, a cyclopentyl group, a cyclohexyl group, or a phenyl group. . In the above formula (2), R ⁴ and R ⁵ are each independently a hydrogen atom or a methyl group, and X ² is an oxygen atom or a nitrogen atom. When X ² is an oxygen atom, R ⁶ does not exist, and when X ² is a nitrogen atom, R ⁶ is a hydrogen atom, a linear alkyl group having 1 to 6 carbon atoms, a cyclopentyl group, a cyclohexyl group, or a phenyl group. . R ⁷ in the above formula (3) is a hydrogen atom or a group represented by the formula “—OR ¹¹ ”, and R ¹¹ is a hydrogen atom, an alkyl group having 1 to 18 carbon atoms or an alkyl ester group. R ^{8 to} R ¹⁰ in the above formula (3) are each independently a hydrogen atom, an alkyl group having 1 to 18 carbon atoms or an alkyl ester group.

  The resin molded product of the present invention is composed of the thermoplastic resin composition of the present invention.

  The polarizer protective film of this invention is 1 type of the resin molded product of this invention, and consists of the thermoplastic resin composition of this invention.

  The polarizing plate of the present invention includes a polarizer and the polarizer protective film of the present invention.

  The image display device of the present invention includes the polarizing plate of the present invention.

  In the method for producing a resin molded product of the present invention, the thermoplastic resin composition of the present invention is extrusion molded into a molded product.

  The resin composition of the present invention has excellent heat resistance based on a high Tg of 110 ° C. or higher by containing a thermoplastic resin mainly composed of the resin (A) and UVA (B) at a predetermined ratio. Even during molding at high temperatures, the occurrence of bleeding out and the like is suppressed, and the occurrence of problems due to UVA transpiration is small.

The resin molded product of the present invention composed of such a resin composition has excellent heat resistance based on the height of Tg, high ultraviolet absorbing ability based on UVA (B), and high transparency based on acrylic resin (A). , Mechanical strength and moldability. Further, the resin molded product of the present invention has few appearance or optical defects due to bleed-out, etc., and this effect is particularly effective when the resin molded product of the present invention is a film or sheet, such as an optical film such as a polarizer protective film. This is particularly noticeable when it is a member.

[Resin composition]
Hereinafter, the resin composition of the present invention will be described in detail.

[Resin (A)]
The resin (A) is not particularly limited as long as it is an acrylic resin having a ring structure represented by the following formula (1) and / or formula (2) in the main chain. However, the resin (A) needs to be an acrylic resin having a Tg of 110 ° C. or more as the resin composition.

In the above formula (1), R ¹ and R ² are each independently a hydrogen atom or a methyl group, and X ¹ is an oxygen atom or a nitrogen atom. When X ¹ is an oxygen atom, R ³ does not exist, and when X ¹ is a nitrogen atom, R ³ is a hydrogen atom, a linear alkyl group having 1 to 6 carbon atoms, a cyclopentyl group, a cyclohexyl group, or a phenyl group. .

When X ¹ is a nitrogen atom, the ring structure represented by the formula (1) is a glutarimide structure. The glutarimide structure can be formed, for example, by imidizing a (meth) acrylic acid ester polymer with an imidizing agent such as methylamine.

When X ¹ is an oxygen atom, the ring structure represented by the formula (1) is a glutaric anhydride structure. The glutaric anhydride structure can be formed, for example, by subjecting a copolymer of (meth) acrylic acid ester and (meth) acrylic acid to dealcoholization cyclocondensation within the molecule.

In the above formula (2), R ⁴ and R ⁵ are each independently a hydrogen atom or a methyl group, and X ² is an oxygen atom or a nitrogen atom. When X ² is an oxygen atom, R ⁶ does not exist, and when X ² is a nitrogen atom, R ⁶ is a hydrogen atom, a linear alkyl group having 1 to 6 carbon atoms, a cyclopentyl group, a cyclohexyl group, or a phenyl group. .

When X ² is a nitrogen atom, the ring structure represented by the formula (2) is an N-substituted maleimide structure. An acrylic resin having an N-substituted maleimide structure in the main chain can be formed, for example, by copolymerization of an N-substituted maleimide and a (meth) acrylic acid ester.

When X ² is an oxygen atom, the ring structure represented by the formula (2) is a maleic anhydride structure. The acrylic resin having a maleic anhydride structure in the main chain can be formed, for example, by copolymerization of maleic anhydride and (meth) acrylic acid ester.

  Here, the acrylic resin is a resin having a (meth) acrylic acid ester unit and / or a (meth) acrylic acid unit as a structural unit. The total ratio of the (meth) acrylic acid ester unit and the (meth) acrylic acid unit in all the structural units of the acrylic resin is usually 50 mol% or more, preferably 60 mol% or more, more preferably 70 mol%. That's it. Resin (A) has a ring structure in the main chain. When the ring structure is a derivative of a (meth) acrylate unit, a (meth) acrylate unit or (meth) acrylic unit in all structural units If the total ratio of the ring structure is 50 mol% or more, an acrylic resin is obtained.

  (Meth) acrylic acid ester units are, for example, methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, n-butyl (meth) acrylate, t- (meth) acrylic acid t- Butyl, n-hexyl (meth) acrylate, cyclohexyl (meth) acrylate, benzyl (meth) acrylate, chloromethyl (meth) acrylate, 2-chloroethyl (meth) acrylate, 2-hydroxy (meth) acrylate Ethyl, 3-hydroxypropyl (meth) acrylate, 2,3,4,5,6-pentahydroxyhexyl (meth) acrylate, 2,3,4,5-tetrahydroxypentyl (meth) acrylate, 2- Α-hydroxyacrylates such as methyl (hydroxymethyl) acrylate and methyl 2- (hydroxyethyl) acrylate Methyl acid, a structural unit derived from the monomers such. Resin (A) may have 2 or more types of these structural units as a (meth) acrylic acid ester unit. The resin (A) preferably has a methyl (meth) acrylate unit. In this case, a resin composition containing the resin (A) and the resin (A) and a resin molded product obtained by molding the composition Thermal stability is improved.

  In each method for forming a ring structure exemplified in the description of formulas (1) and (2), all the polymers used for forming each ring structure have (meth) acrylate units as constituent units. The resin obtained by the above methods is an acrylic resin.

  The content of the ring structure in the resin (A) is not particularly limited, but is usually 5 to 90% by weight, preferably 10 to 70% by weight, more preferably 10 to 60% by weight, and further 10 to 50% by weight. preferable. When the said content rate becomes small too much, the heat resistance of the resin composition and the resin molded product obtained by shape | molding the said composition may fall, or solvent resistance and surface hardness may become inadequate. On the other hand, when the said content rate becomes large too much, the moldability and handling property of a resin composition will fall.

The Tg of the resin (A) is usually 110 ° C. or higher because the Tg of the resin composition containing the resin (A) and UVA (B) is 110 ° C. or higher. The Tg of the resin (A) is preferably 115 ° C. or higher, more preferably 120 ° C. or higher, and further preferably 130 ° C. or higher.

  A high Tg of the resin (A) of 110 ° C. or higher, and in some cases 130 ° C. or higher is achieved by the resin (A) having a ring structure in the main chain. For example, Tg of polymethyl methacrylate (PMMA), which is a typical acrylic resin having no ring structure in the main chain, is 105 ° C. That is, the resin (A) having a ring structure in the main chain improves the heat resistance of a resin molded product obtained from the composition of the present invention containing the resin (A). Thus, a resin molded product with improved heat resistance, such as a resin film, is suitable for use as an optical member because it can be easily placed near a heat generating part such as a light source in an image display device.

  By the way, when Tg of a resin composition becomes high by including resin (A) which has ring structure in a principal chain, it is necessary to make the molding temperature of the said composition high. The acrylic resin composition is usually formed into a molded product by extrusion molding, and at that time, a molding temperature equal to or higher than Tg of the composition is required. When the molding temperature is high, foaming and UVA bleed out are likely to occur during molding, and UVA transpiration tends to be strong. However, in the resin composition of the present invention, even in such a case, the occurrence of bleed-out is small, and the occurrence of problems due to UVA transpiration can be suppressed.

  The resin (A) may have a structural unit other than the (meth) acrylic acid ester unit and the (meth) acrylic acid unit. Examples of such a structural unit include styrene, vinyltoluene, and α-methylstyrene. , Acrylonitrile, methyl vinyl ketone, ethylene, propylene, vinyl acetate, methallyl alcohol, allyl alcohol, 2-hydroxymethyl-1-butene, α-hydroxymethylstyrene, α-hydroxyethylstyrene, etc. It is a structural unit. The resin (A) may have two or more of these structural units.

  Resin (A) may have a structural unit having an effect of giving negative intrinsic birefringence to the resin. In this case, the degree of freedom in controlling the birefringence of the resin composition and the resin molded product obtained by molding the composition is improved, and the resin molded product (for example, resin film) formed from the resin composition of the present invention. Use as an optical member is expanded.

  Intrinsic birefringence refers to the orientation axis from the refractive index n1 of light in a direction parallel to the direction (orientation axis) in which molecular chains are oriented in a layer (for example, a sheet or film) in which resin molecular chains are uniaxially oriented. A value obtained by subtracting the refractive index n2 of the light in the direction perpendicular to (i.e., "n1-n2"). The sign of the intrinsic birefringence of the resin (A) itself is determined by the balance between the action of the structural unit with respect to the intrinsic birefringence and the action of the other structural unit of the resin (A).

  An example of a structural unit having an effect of giving negative intrinsic birefringence to the resin (A) is a styrene unit.

  The resin (A) may have a structural unit (UVA unit) having ultraviolet absorbing ability. In this case, the ultraviolet absorbing ability of the resin composition and the resin molded product obtained by molding the composition is further improved. Depending on the structure of the UVA unit, the compatibility between the resin (A) and the UVA (B) is improved.

  The monomer (C) that is the source of the UVA unit is not particularly limited, and is, for example, a benzotriazole derivative, a triazine derivative, or a benzophenone derivative into which a polymerizable group is introduced. The polymerizable group to be introduced can be appropriately selected according to the structural unit of the resin (A).

Specific examples of the monomer (C) include 2- (2′-hydroxy-5′-methacryloyloxy) ethylphenyl-2H-benzotriazole (manufactured by Otsuka Chemical Co., Ltd., trade name RUVA-93), 2-
(2′-hydroxy-5′-methacryloyloxy) phenyl-2H-benzotriazole, 2- (2′-hydroxy-3′-t-butyl-5′-methacryloyloxy) phenyl-2H-benzotriazole.

  Specific examples of the monomer (C) other than the above are triazine derivatives represented by the following formulas (4), (5) and (6) or benzotriazole derivatives represented by the following formula (7). .

  When resin (A) contains a UVA unit, the content of the unit in resin (A) is preferably 20% by weight or less, and more preferably 15% by weight or less. When the content of the UVA unit in the resin (A) exceeds 20% by weight, the heat resistance as the resin composition is lowered.

  The weight average molecular weight of the resin (A) is, for example, in the range of 1,000 to 300,000, preferably in the range of 5,000 to 250,000, more preferably in the range of 10,000 to 200,000, and still more preferably in the range of 50,000 to 200,000.

  Resin (A) can be manufactured by a well-known method. A resin (A) having an N-substituted maleimide structure in the main chain, a resin (A) having a glutaric anhydride structure in the main chain, and a resin (A) having a glutarimide structure in the main chain are disclosed in, for example, JP-A-2007- It can be produced by the methods described in Japanese Patent No. 31537, WO2007 / 26659, and WO2005 / 108438. The resin (A) having a maleic anhydride structure in the main chain can be produced, for example, by the method described in JP-A-57-153008.

[UVA (B)]
UVA (B) has a structure represented by the following formula (3).

R ⁷ in the above formula (3) is a hydrogen atom or a group represented by the formula “—OR ¹¹ ”, and R ¹¹ is a hydrogen atom, an alkyl group having 1 to 18 carbon atoms or an alkyl ester group. R ^{8 to} R ¹⁰ in the above formula (3) are each independently a hydrogen atom, an alkyl group having 1 to 18 carbon atoms or an alkyl ester group. The alkyl ester group is preferably a group represented by the formula “—CH (—R ¹² ) C (═O) OR ¹³ ”. In the above formula, R ¹² is a hydrogen atom or a methyl group, and R ¹³ is an alkyl group. R ^{8 to} R ^10, R ^11, and R ¹³ that are alkyl groups may be linear alkyl groups or branched alkyl groups.

  UVA (B) has a phenyltriazine skeleton, and has at least two hydroxyphenyl groups bonded to the triazine in the skeleton. The hydrogen atom of the hydroxyl group in this hydroxyphenyl group forms a hydrogen bond with the nitrogen atom of triazine, and the formed hydrogen bond increases the action as a chromophore of the phenyltriazine skeleton. In UVA (B), since at least two hydrogen bonds are formed, the action of the phenyltriazine skeleton as a chromophore can be further increased, and a high UV absorbing ability can be obtained with a small amount of UVA (B) added. it can.

  In addition, since the resin (A) is an acrylic resin having a ring structure in the main chain and the compatibility between the resin (A) and UVA (B) is high, the resin composition of the present invention provides heat resistance. A resin molded product having excellent properties and transparency can be obtained.

R ⁷ in the above formula (3) is preferably a group represented by the above formula “—OR ¹¹ ”, that is, a hydroxyl group, an alkoxy group or an alkyl esteroxy group. In this case, the action of the phenyl triazine skeleton as a chromophore is further increased. Since the effect of increasing the above action is high, it is preferable that R ¹¹ is a hydrogen atom, that is, R ⁷ is a hydroxyl group.

When R ⁷ is a hydroxyl group, UVA (B) has a hydroxyphenyl triazine skeleton ((2-hydroxyphenyl) -1,3,5-triazine skeleton) in which three hydroxyphenyl groups are bonded to triazine.

R ^{8 to} R ¹⁰ in the above formula (3) are preferably alkyl groups or alkyl ester groups, and in this case, compatibility between the resin (A) and the UVA (B) is improved. Since the effect which can improve the said compatibility is high, it is preferable that R < ⁸ > -R < ¹⁰ > is an alkylester group.

  Specific examples of UVA (B) are given in the following formulas (8) to (12). However, UVA (B) is not limited to the example shown below.

Commercially available ultraviolet absorbers containing UVA (B) represented by the above formula (8) as a main component and UVA (B) represented by the above formulas (9) and (10) as subcomponents include, for example, CGL777MPAD (Ciba Specialty Chemicals). In addition, commercially available ultraviolet absorbers containing UVA (B) represented by the above formula (11) as a main component include, for example, T
INUVIN460 (manufactured by Ciba Specialty Chemicals) is available. In addition, the main component in this specification means a component with most content (content rate), and the content rate is typically 50 weight% or more.

In UVA (B), the molar extinction coefficient of the maximum absorption wavelength for light in the wavelength range of 300 nm to 380 nm is preferably 10,000 (L · mol ⁻¹ · cm ⁻¹ ) or more in the chloroform solution.

  Since the Tg of the resin composition of the present invention is 110 ° C. or higher and the temperature required for molding (for example, extrusion molding) is high, a gel may be formed during molding. Gels are more likely to occur as the molding temperature increases. For this reason, the higher the Tg of the composition, the higher the required molding temperature, and the easier it is to produce a gel.

  Here, UVA (B) does not have a structure that can be a crosslinking point of the resin (A) such as a thiol group, a hydroxyl group, an amine group, and a carbon-carbon double bond. For this reason, in the resin composition of this invention, generation | occurrence | production of the gel at the time of the shaping | molding can be suppressed, and the resin film (for example, optical films, such as a polarizer protective film) with few external appearance or an optical defect is obtained. Moreover, since the molding temperature of the composition can be further increased by suppressing the generation of gel, (1) the melt viscosity of the composition during molding is lowered and the productivity of the resin molded product is improved. (2) When filtering with a polymer filter at the time of molding for the purpose of removing foreign substances such as gel, effects such as a longer filter replacement cycle can be obtained by suppressing the generation of gel.

  The hydroxyphenyl group in UVA (B) represented by the formula (3) has a hydroxyl group as a substituent, but the hydroxyl group directly bonded to the benzene ring does not form a crosslinked structure with the resin (A), so that it becomes a crosslinking point. I don't think it's a possible structure.

  By the way, there is triacetyl cellulose (TAC) as one of the materials used as an optical member. However, since TAC has a decomposition temperature as low as about 250 ° C., extrusion molding cannot be used. It is formed into a film by (cast method). That is, since the TAC itself is not exposed to a high temperature during the formation of the TAC film, whether or not there is a structure in the UVA that can be a crosslinking point with the TAC depends on the occurrence frequency and productivity of optical defects in the TAC film. Does not affect.

[Resin composition]
The resin composition of the present invention contains a resin (A) and UVA (B), and the content of UVA (B) in the composition is 100 parts by weight of the thermoplastic resin including the resin (A). That is, when the total weight of the thermoplastic resin contained in the composition is 100 parts by weight, the range is 0.1 to 5 parts by weight. When the content of UVA (B) is smaller than the above range, sufficient ultraviolet absorbing ability cannot be obtained. On the other hand, when the content of UVA (B) is larger than the above range, the demerit that foaming or bleed-out occurs at the time of molding becomes larger than the merit of increasing the ultraviolet absorbing ability.

  The content of UVA (B) in the resin composition of the present invention is preferably 0.5 to 4 parts by weight, more preferably 1 to 3 parts by weight with respect to 100 parts by weight of the thermoplastic resin.

The main component of the thermoplastic resin contained in the resin composition of the present invention is the resin (A). Specifically, the proportion of the resin (A) in the entire thermoplastic resin contained in the resin composition of the present invention is usually 60% by weight or more, preferably 70% by weight or more, more preferably 85% by weight or more. It is. In other words, the resin composition of the present invention has a thermoplastic resin other than the resin (A) in a proportion of less than 40% by weight (preferably 30% by weight) based on the total thermoplastic resin contained in the composition. Less than 15% by weight, more preferably less than 15% by weight.

  Such thermoplastic resins include, for example, olefin polymers such as polyethylene, polypropylene, ethylene-propylene copolymer, poly (4-methyl-1-pentene); halogen-containing polymers such as vinyl chloride and chlorinated vinyl resins; polystyrene Styrene polymers such as styrene-methyl methacrylate copolymer, styrene-acrylonitrile copolymer, acrylonitrile-butadiene-styrene block copolymer; polyesters such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate; nylon 6, nylon 66 Polyamide, Polyamide, Polyphenylene oxide, Polyphenylene sulfide, Polyether ether ketone, Polysulfone, Polyether Rusaruhon; polyoxyethylene Penji alkylene; polyamideimide; polybutadiene rubber or ABS resin containing an acrylic rubber, rubber-like polymer such as ASA resin; and the like. The rubbery polymer preferably has on its surface a graft portion having a composition compatible with the resin (A). When the rubbery polymer is in the form of particles, the average particle size is determined according to the present invention. From the viewpoint of improving transparency when the resin composition is a resin film, 300 nm or less is preferable, and 150 nm or less is more preferable.

  Among the above-exemplified thermoplastic resins, since it has excellent compatibility with the resin (A), it includes a structural unit derived from a vinyl cyanide monomer and a structural unit derived from an aromatic vinyl monomer. A copolymer is preferred. The copolymer is, for example, a styrene-acrylonitrile copolymer or a vinyl chloride resin.

  The resin composition of the present invention has a high glass transition temperature (Tg) of 110 ° C. or higher based on the resin (A). Depending on the structure of the resin (A) (for example, the kind of ring structure in the resin (A), the content, etc.), the Tg of the resin composition of the present invention is 115 ° C. or higher, 120 ° C. or higher, and further 130 ° C. or higher. .

  The resin composition of the present invention has a high ultraviolet absorbing ability based on UVA (B). For example, when the film has a thickness of 100 μm, the transmittance of light having a wavelength of 380 nm is less than 30%, and in some cases, 20 %, Further less than 10%, and less than 1%. What is necessary is just to measure this transmittance | permeability based on prescription | regulation of JISK7361: 1997.

  The resin composition of the present invention has a high visible light transmittance based on the compatibility between the resin (A) and the UVA (B). For example, when the film has a thickness of 100 μm, it transmits light having a wavelength of 500 nm. The rate can be 80% or more, in some cases 85% or more, and even 90% or more. This transmittance can be measured in the same manner as the transmittance of light having a wavelength of 380 nm.

  In the resin composition of the present invention, the combination of the resin (A) and UVA (B) described above can improve the hue of the composition and a resin molded product obtained by molding the composition.

  The resin composition of the present invention may contain a polymer having negative intrinsic birefringence. In this case, the degree of freedom in controlling the birefringence of the resin composition and the resin molded product obtained by molding the composition is improved.

  The polymer having negative intrinsic birefringence is, for example, a copolymer of a vinyl cyanide monomer and an aromatic vinyl monomer. The copolymer is, for example, a styrene-acrylonitrile copolymer, and the styrene-acrylonitrile copolymer is excellent in compatibility with the resin (A) in a wide range of copolymer compositions.

The styrene-acrylonitrile copolymer can be produced by various polymerization methods such as emulsion polymerization, suspension polymerization, solution polymerization, and bulk polymerization. When a resin molded article formed from the resin composition of the present invention is used as an optical member, it is preferable to use a styrene-acrylonitrile copolymer produced by solution polymerization or bulk polymerization because transparency and optical properties are improved. .

  The resin composition of the present invention may contain an antioxidant. Although antioxidant is not specifically limited, For example, well-known antioxidants, such as a hindered phenol type, a phosphorus type, or a sulfur type, can be used by 1 type or in combination of 2 or more types. In particular, 2,4-di-t-amyl-6- [1- (3,5-di-t-amyl-2-hydroxyphenyl) ethyl] phenyl acrylate (e.g., Sumitizer Chemicals Sumitizer GS), and 2 -T-Butyl-6- (3-t-butyl-2-hydroxy-5-methylbenzyl) -4-methylphenyl acrylate (for example, Sumitomo Chemical's Smither GM) deteriorates the resin composition during high temperature molding It is preferable because of its high effect of suppressing the above.

  The addition amount of the antioxidant in the resin composition of the present invention is, for example, 0 to 3% by weight, preferably 0.02 to 1% by weight, and more preferably 0.05 to 1% by weight.

  The resin composition of the present invention may contain other additives. Other additives include, for example, a stabilizer such as a light stabilizer, a weather stabilizer, and a heat stabilizer; a reinforcing material such as a glass fiber and a carbon fiber; a near infrared absorber; a tris (dibromopropyl) phosphate, a triallyl phosphate, Flame retardants such as antimony oxide; antistatic agents typified by anionic, cationic, and nonionic surfactants; colorants such as inorganic pigments, organic pigments, dyes; organic fillers, inorganic fillers; resin modifiers; Plasticizers; lubricants; flame retardants. The amount of the other additives added in the resin composition of the present invention is, for example, 0 to 5% by weight, preferably 0 to 2% by weight, and more preferably 0 to 0.5% by weight.

  The resin composition of the present invention can be formed into an arbitrary shape such as a film or sheet by a known molding technique such as injection molding, blow molding, extrusion molding or cast molding. The molding temperature may be appropriately set according to the Tg and characteristics of the resin composition, and is not particularly limited, but is, for example, 150 to 350 ° C, and preferably 200 to 300 ° C.

  The resin molded product obtained by molding the resin composition of the present invention has few defects due to bleed-out and the like, and has high ultraviolet absorbing ability, heat resistance and transparency.

[Method for Producing Resin Composition]
The resin composition of the present invention can be produced by mixing a thermoplastic resin mainly composed of the resin (A) and UVA (B) by a known method. The produced resin composition may be pelletized with a pelletizer or the like, if necessary.

  The timing which mixes a thermoplastic resin and UVA (B) is not specifically limited unless the above-mentioned various characteristics as a resin composition are inhibited. UVA (B) may be added during polymerization of a thermoplastic resin (for example, resin (A)), or after polymerization of the thermoplastic resin, the obtained thermoplastic resin and UVA (B) are mixed (for example, Melt kneading). The specific method for melt-kneading the thermoplastic resin and UVA (B) is not particularly limited. For example, the thermoplastic resin, UVA (B) and other components to be added may be simultaneously heated and melted and kneaded. Alternatively, after the thermoplastic resin and other components to be added are heated and melted, UVA (B) may be further added thereto and kneaded. Further, after the thermoplastic resin is heated and melted, UVA (B) and other components to be added may be further added and kneaded.

[Resin molded product]
The resin molded product of the present invention comprises the resin composition of the present invention. The resin molded product of the present invention has various characteristics based on the characteristics of the above-described resin composition of the present invention. For example, the resin molded product of the present invention has high ultraviolet absorption ability, heat resistance and transparency. For example, the resin molded product of the present invention has few defects such as bleed out.

  Due to these characteristics, the resin molded product of the present invention can be suitably used as an optical member. Further, due to the high heat resistance, it can be placed close to a heat generating part such as a light source.

  The shape of the resin molded product of the present invention is not particularly limited, and is, for example, a film or a sheet.

  The thickness of the resin molded product of the present invention that is a film is, for example, 1 μm or more and less than 350 μm, and preferably 10 μm or more and less than 350 μm. When the thickness is less than 1 μm, the strength as a resin film may be insufficient, and breakage or the like is likely to occur during post-processing such as stretching.

  The thickness of the resin molded product of the present invention which is a sheet is, for example, 350 μm or more and 10 mm or less, preferably 350 μm or more and 5 mm or less. When the thickness exceeds 10 mm, it becomes difficult to make the sheet thickness uniform, and it becomes difficult to use the resin sheet as an optical member.

  The resin sheet and the resin film can be formed, for example, by extruding the resin composition of the present invention.

  The resin molded product of the present invention has a high Tg, for example, a value of 110 ° C. or higher. Depending on the composition of the resin composition constituting the resin molded product, Tg is 115 ° C. or higher, 120 ° C. or higher, and further 130 ° C. or higher.

  The resin molded product of the present invention has a high ultraviolet absorbing ability. For example, in the case of a film having a thickness of 100 μm, the transmittance of light having a wavelength of 380 nm can be less than 30%, sometimes less than 20%, further less than 10%, and less than 1%.

  The resin molded product of the present invention has a high visible light transmittance. For example, when a film having a thickness of 100 μm is used, the transmittance of light having a wavelength of 500 nm can be 80% or more, in some cases 85% or more, 90% or more, and further 92% or more. The transmittance of the film (sheet) with respect to light having a wavelength of 380 nm and light having a wavelength of 500 nm may be measured according to the method described above.

  The resin molded product of the present invention preferably has a tensile strength measured according to ASTM-D-882-61T of 10 MPa or more and less than 100 MPa, and more preferably 30 MPa or more and less than 100 MPa. When the said tensile strength is less than 10 Mpa, the mechanical strength as a resin sheet (film) may become inadequate. On the other hand, when the tensile strength exceeds 100 MPa, the workability decreases.

  The resin molded article of the present invention preferably has an elongation percentage measured according to ASTM-D-882-61T of 1% or more. Although the upper limit of the said elongation rate is not specifically limited, Usually, it is 100% or less. When the said elongation rate is less than 1%, the toughness as a resin sheet (film) may become inadequate.

The resin molded product of the present invention preferably has a tensile elastic modulus measured according to ASTM-D-882-61T of 0.5 GPa or more, more preferably 1 GPa or more, and 2 GPa or more. More preferably. Although the upper limit of the said tensile elasticity modulus is not specifically limited, Usually, it is 20 GPa or less. When the said tensile elasticity modulus is less than 0.5 GPa, the mechanical strength as a resin sheet (film) may become inadequate.

  Various functional coating layers may be formed on the surface of the resin molded product of the present invention which is a sheet or a film, if necessary. Functional coating layers include, for example, antistatic layers, adhesive layers, adhesive layers, easy adhesion layers, antiglare (non-glare) layers, antifouling layers such as photocatalyst layers, antireflection layers, hard coat layers, and UV shielding layers. Layers, heat ray shielding layers, electromagnetic wave shielding layers, gas barrier layers, and the like. Moreover, the member which has the functional coating layer mentioned above may be laminated | stacked on the resin molded product of this invention. Lamination of the member can be performed via an adhesive or an adhesive.

  Although the use of the resin molded product of the present invention which is a sheet or a film is not particularly limited, it can be suitably used as an optical member due to its high transparency, heat resistance and ultraviolet absorbing ability. The optical member is, for example, an optical protective film (sheet), specifically, a protective film for various optical disk (VD, CD, DVD, MD, LD, etc.) substrates, and an image display device such as a liquid crystal display (LCD). It is a polarizer protective film used for the polarizing plate with which is provided. Retardation film, viewing angle compensation film, light diffusion film, reflection film, antireflection film, antiglare film, brightness enhancement film, optical film such as touch panel conductive film, or diffusion plate, light guide, retardation plate The resin molded product of the present invention may be used as an optical sheet such as a prism sheet.

  A polarizer protective film will be described as an example. A pair of polarizing plates is arranged in the LCD so as to sandwich the liquid crystal cell based on the principle of image display. The polarizing plate generally includes a polarizer made of a resin film such as polyvinyl alcohol, and a polarizer protective film for protecting the polarizer. According to the polarizer protective film of the present invention, deterioration of the polarizer due to ultraviolet rays can be suppressed due to its high ultraviolet absorbing ability. Further, the high heat resistance makes it possible to dispose the polarizing plate close to the light source, and the high transparency makes it possible to form an image display device having excellent image display characteristics.

  Although the structure of a polarizing plate is not specifically limited, Usually, it has the structure where the polarizer was pinched | interposed by a pair of polarizer protective film.

  The polarizing plate provided with the polarizer protective film of the present invention (polarizing plate of the present invention) is, for example, a reflective, transmissive, or transflective LCD; TN type, STN type, OCB type, HAN type, VA type, IPS It can be used for image display devices such as LCDs having various driving methods such as molds, electroluminescence (EL) displays, plasma displays (PD), and field emission displays (FEDs).

[Production method of resin molded product]
As described above, the method for producing a resin molded product of the present invention is not particularly limited, but an example of a method for producing a resin film as a resin molded product will be shown below. This manufacturing method can also be applied to a method for manufacturing a resin sheet.

  As a method for producing a resin film from the resin composition of the present invention, there is an extrusion molding method. As a specific example, after each component constituting the resin composition is pre-blended with a mixer such as an omni mixer, the resulting mixture may be extrusion kneaded from a kneader. The kneader used for the extrusion kneading is not particularly limited, and for example, a known kneader such as a single screw extruder, a twin screw extruder, or a pressure kneader can be used.

Alternatively, a separately formed resin composition may be melt-extruded. In the melt extrusion method, for example,
There are T-die method, inflation method, etc., and the molding temperature at that time is preferably 200 to 350 ° C., more preferably 250 to 300 ° C., further preferably 255 to 300 ° C., particularly preferably 260 to 300 ° C. is there.

  When the T-die method is used, a resin film wound into a roll can be obtained by attaching a T-die to the tip of the extruder and winding the film extruded from the T-die. At this time, it is also possible to control the temperature and speed of winding and to stretch (uniaxial stretching) in the extrusion direction of the film. Further, the film may be stretched in a direction perpendicular to the extrusion direction, and sequential biaxial stretching or simultaneous biaxial stretching may be performed.

  When an extruder is used for extrusion molding, the type is not particularly limited and may be uniaxial, biaxial, or multiaxial, but its L / D value is (L is the value of the extruder) 10 to 100, preferably 20 to 50, more preferably 25 to 40, in order to sufficiently plasticize the resin composition and obtain a good kneaded state. preferable. When the L / D value is less than 10, the resin composition cannot be sufficiently plasticized and a good kneaded state may not be obtained. On the other hand, if the L / D value exceeds 100, the resin in the composition may be thermally decomposed due to excessive generation of shear heat to the resin composition.

  In this case, the set temperature of the cylinder is preferably 200 ° C. or higher and 300 ° C. or lower, and more preferably 250 ° C. or higher and 300 ° C. or lower. If setting temperature is less than 200 degreeC, the melt viscosity of a resin composition will become high too much, and the productivity of a resin film will fall. On the other hand, if the set temperature exceeds 300 ° C., the resin in the resin composition may be thermally decomposed.

  When an extruder is used for extrusion molding, the shape is not particularly limited, but the extruder preferably has one or more open vent portions. By using such an extruder, the decomposition gas can be sucked from the open vent portion, and the amount of volatile components remaining in the obtained resin film can be reduced. In order to suck the decomposition gas from the open vent portion, for example, the open vent portion may be in a reduced pressure state, and the degree of pressure reduction is 931 to 1.3 hPa (700 to 1 mmHg) as the pressure of the open vent portion. The range is preferable, and the range of 798 to 13.3 hPa (600 to 10 mmHg) is more preferable. When the pressure in the open vent portion is higher than 931 hPa, volatile components or monomer components generated by decomposition of the resin tend to remain in the resin composition. On the other hand, it is industrially difficult to keep the pressure of the open vent part lower than 1.3 hPa.

  When producing a resin film used as an optical member such as an optical film, a resin composition filtered with a polymer filter may be molded. Since the foreign matter present in the resin composition can be removed by the polymer filter, defects in the appearance of the obtained film can be reduced. In addition, the resin composition will be in a high temperature molten state at the time of filtration with a polymer filter. For this reason, the resin composition deteriorates when passing through the polymer filter, gas components and colored deterioration products formed by the deterioration flow into the composition, and the resulting film is perforated, flow pattern, flow Defects such as streaks may be observed. This defect is particularly easily observed during continuous molding of a resin film. For this reason, when molding the resin composition filtered through the polymer filter, the molding temperature decreases the melt viscosity of the resin composition and shortens the residence time of the resin composition in the polymer filter, for example, 255. It is -300 degreeC and 260-320 degreeC is preferable.

The configuration of the polymer filter is not particularly limited, but a polymer filter in which a large number of leaf disk filters are arranged in a housing can be suitably used. The filter material of the leaf disk type filter may be any of a type in which a metal fiber nonwoven fabric is sintered, a type in which metal powder is sintered, a type in which several metal meshes are laminated, or a hybrid type in which they are combined. The sintered type is most preferred.

  The filtration accuracy by the polymer filter is not particularly limited, but is usually 15 μm or less, preferably 10 μm or less, more preferably 5 μm or less. When the filtration accuracy is 1 μm or less, the residence time of the resin composition becomes longer, so that the thermal degradation of the composition increases and the productivity of the resin film decreases. On the other hand, when the filtration accuracy exceeds 15 μm, it is difficult to remove foreign substances in the resin composition.

The filtration area with respect to the resin treatment amount per hour in the polymer filter is not particularly limited, and can be appropriately set according to the treatment amount of the resin composition. The filtration area is, for example, 0.001 to 0.15 m ² / (kg / h).

  The shape of the polymer filter is not particularly limited. For example, an inner flow type having a plurality of resin flow ports and a resin flow path in the center pole; an inner peripheral surface of the leaf disk filter at a plurality of vertices or faces And an external flow type having a resin flow path on the outer surface of the center pole. In particular, it is preferable to use an external flow type in which the resin stays are small.

  Although there is no restriction | limiting in particular in the residence time of the resin composition in a polymer filter, 20 minutes or less are preferable, 10 minutes or less are more preferable, and 5 minutes or less are further more preferable. Moreover, the filter inlet pressure and the filter outlet pressure at the time of filtration are, for example, 3 to 15 MPa and 0.3 to 10 MPa, respectively, and the pressure loss (pressure difference between the filter inlet pressure and the outlet pressure) is 1 MPa to 15 MPa. A range is preferred. When the pressure loss is 1 MPa or less, the resin composition tends to be biased in the flow path through the filter, and the quality of the obtained resin film tends to deteriorate. On the other hand, when the pressure loss exceeds 15 MPa, the polymer filter is easily damaged.

  What is necessary is just to set suitably the temperature of the resin composition introduce | transduced into a polymer filter according to the melt viscosity, for example, it is 250-300 degreeC, 255-300 degreeC is preferable and 260-300 degreeC is more preferable.

  The specific process of obtaining a resin film with few foreign substances and colored substances by filtration using a polymer filter is not particularly limited. For example, (1) a process in which a resin composition is formed and filtered in a clean environment, and then the resin composition is molded in a clean environment; (2) a resin composition having foreign matters or colored substances is cleaned A process in which the resin composition is subsequently molded in a clean environment after being filtered in an environment; (3) a process in which a resin composition having a foreign substance or a colored product is simultaneously filtered and molded in a clean environment; Etc. You may perform the filtration process of the resin composition by a polymer filter in multiple times for each process.

  When filtering the resin composition with the polymer filter, it is preferable to install a gear pump between the extruder and the polymer filter to stabilize the pressure of the resin composition in the filter.

  The resin composition of the present invention is preferably extruded as it is after the production to obtain a resin film. Since heat history can be reduced as compared with the case where a resin film is formed by remelting the pellet obtained after pelletizing the resin composition, thermal deterioration of the resin composition can be suppressed. Moreover, in this method, since mixing of the foreign material from an environment can be suppressed, it can suppress that a foreign material exists in the obtained resin film, or coloring of the obtained resin film. A gear pump and a polymer filter are preferably arranged between the extruder and the T die.

The resin film obtained by extrusion may be stretched as necessary. The type of stretching is not particularly limited, and may be uniaxial stretching or biaxial stretching. The mechanical strength of the resin film can be improved by stretching, and in some cases, birefringence can be imparted to the resin film. In addition, the resin composition of this invention can maintain optical isotropy after extending | stretching depending on the composition. The stretching temperature is not particularly limited, and a temperature in the vicinity of Tg of the resin composition is preferable. The draw ratio and the draw speed are not particularly limited.

  In order to stabilize the optical properties and mechanical properties of the resin film, heat treatment (annealing) may be performed as necessary after stretching.

  Hereinafter, the present invention will be described in more detail with reference to examples. The present invention is not limited to the examples shown below.

  Initially, the evaluation method of the resin composition sample produced in the present Example is shown.

[Glass-transition temperature]
The glass transition temperature (Tg) of each sample was determined in accordance with JIS K7121 regulations. Specifically, a differential scanning calorimeter (manufactured by Rigaku Corporation, DSC-8230) is used to raise a temperature of about 10 mg from room temperature to 200 ° C. (temperature increase rate: 20 ° C./min) in a nitrogen gas atmosphere. From the obtained DSC curve, it evaluated by the starting point method. Α-alumina was used as a reference.

[Light transmittance]
The light transmittance of each sample was obtained by forming the film with a thickness of 100 μm by extrusion molding, and then using the spectrophotometer (manufactured by Shimadzu Corporation, UV-3100) to determine the transmittance of the film with respect to light with wavelengths of 380 nm and 500 nm. It evaluated by measuring. A specific method for forming a 100 μm thick film from each sample will be described later.

[Sublimation]
The sublimation property of UVA in each sample was evaluated as follows. First, each sample was formed into a film having a thickness of 100 μm by extrusion, and a part (size: 1 cm × 3 cm) was cut out. Next, after the cut film was sealed in a test tube, it was heated in a metal bath at 150 ° C. for 10 hours. Next, after taking out the film from the test tube, 1 mL of chloroform was put into the test tube, and UVA sublimated from the film and adhered to the inner wall of the test tube was dissolved in chloroform. Next, chloroform in which UVA was dissolved was accommodated in a quartz cell having an optical path length of 1 cm, and the absorbance with respect to light having a wavelength of 350 nm was measured using an absorptiometer (manufactured by Shimadzu Corporation, UV-3100). The greater the amount of UVA sublimation, the greater the measured absorbance.

[Spattering]
The degree of contamination of the molding apparatus when molding each sample was evaluated by measuring the amount of UVA attached to the cast roll (the metal roll with which the molten resin film extruded from the T-die first contacts). The amount of adhesion was evaluated as follows. First, after a resin film was continuously extrusion-molded for 1 hour by a molding apparatus equipped with a cast roll, a 10 cm × 10 cm range at the center of the roll was wiped off with a cellulose wiper dipped in chloroform. Next, the wiper used for wiping was immersed in 30 mL of chloroform, and UVA wiped off from the cast roll was dissolved in chloroform. Next, chloroform in which UVA was dissolved was accommodated in a quartz cell having an optical path length of 1 cm, and the absorbance with respect to light having a wavelength of 350 nm was measured using an absorptiometer (manufactured by Shimadzu Corporation, UV-3100). The greater the amount of UVA attached to the cast roll (ie, the higher the UVA scattering property), the greater the measured absorbance.

[Change in turbidity of film]
The amount of change in turbidity of the film formed from each sample was evaluated as follows. First, each sample was formed into a film having a thickness of 100 μm by extrusion, and a part (size: 5 cm × 5 cm) was cut out. Next, the turbidity of the cut out film was measured using a turbidimeter (Nippon Denshoku Industries Co., Ltd., NDH-1001DP), and the measured value was taken as the initial value. Next, the cut film is left in a hot air dryer (made by Tabai Co., Ltd.) maintained at 100 ° C. for 200 hours, and then the turbidity of the film after being left is measured again to determine the amount of change from the initial value. Asked. As a factor that changes the turbidity of the film after molding, bleedout of UVA due to heat can be considered.

Example 1
As a resin (A), a glutarimide-containing acrylic resin (Rohm and Haas, KAMAX T-240) is charged into a hopper, and a twin screw extruder (Φ30 mm, L / D = 42) having two vents, The resin was melted under the conditions of a barrel temperature of 260 ° C., a rotation speed of 100 rpm, a reduced pressure of 13 hPa, and a treatment speed of 10 kg / hour. Next, a solution obtained by mixing 19 parts by weight of CGL777MPAD (manufactured by Ciba Specialty Chemicals Co., Ltd., active ingredient 80% by weight) and 11 parts by weight of toluene as UVA (B) with the melt of resin (A) The resin composition (D-1) was obtained by pressure injection at a rate of 0.30 kg / hr. When calculated from the processing speed of the resin (A) and the injection speed of the UVA (B), the amount of UVA (B) added to the resin composition (D-1) is 100 parts by weight of the resin (A) (that is, 1.5 parts by weight) (100 parts by weight of the thermoplastic resin contained in the composition (D-1)).

The glutarimide-containing acrylic resin used as the resin (A) has a glutarimide structure in which X ¹ is a nitrogen atom and R ^{1 to} R ³ are CH ₃ in the main chain in the above formula (1).

(Example 2)
As resin (A), a glutaric anhydride-containing acrylic resin (Sumitomo Chemical Co., Sumipex B-TR) was charged into a hopper, and a twin screw extruder (Φ30 mm, L / D = 42) having two vents, The resin was melted under the conditions of a barrel temperature of 260 ° C., a rotation speed of 100 rpm, a reduced pressure of 13 hPa, and a treatment speed of 10 kg / hour. Next, a solution obtained by mixing 19 parts by weight of CGL777MPAD (manufactured by Ciba Specialty Chemicals Co., Ltd., active ingredient 80% by weight) and 11 parts by weight of toluene as UVA (B) with the melt of resin (A) The resin composition (D-2) was obtained by pressure injection at a rate of 0.30 kg / hr. When calculated from the processing speed of the resin (A) and the injection speed of the UVA (B), the amount of UVA (B) added to the resin composition (D-2) is 100 parts by weight of the resin (A) (that is, 1.5 parts by weight) (100 parts by weight of the thermoplastic resin contained in the composition (D-2)).

The glutaric anhydride-containing acrylic resin used as the resin (A) has a glutaric anhydride structure in which X ¹ is an oxygen atom and R ¹ and R ² are CH ₃ in the above formula (1) as a main chain. Have.

(Example 3)
In a 100-liter stainless steel polymerization tank equipped with a submerged tank and a stirrer, 42.5 parts by weight of methyl methacrylate, 5 parts by weight of N-phenylmaleimide, 0.5 parts by weight of styrene, 50 weights as a polymerization solvent Of toluene, 0.2 parts by weight of acetic anhydride as an organic acid, and 0.06 parts by weight of n-dodecyl mercaptan as a chain transfer agent were added, and nitrogen gas was bubbled for 10 minutes while stirring at a rotational speed of 100 rpm. I let you. Next, while maintaining the inside of the tank in a nitrogen atmosphere, the temperature in the polymerization tank was raised, and when the temperature in the tank reached 100 ° C., 0.07
5 parts by weight of t-butylperoxyisopropyl carbonate was added, and simultaneously, bubbling of nitrogen was started in the submerged tank. Next, while adding a mixed solution of 2 parts by weight of styrene and 0.075 parts by weight of t-butylperoxyisopropyl carbonate to the tank at a rate over 5 hours, refluxing at a polymerization temperature of 105 to 110 ° C. The polymerization reaction was allowed to proceed for 15 hours.

  Next, 9,10-dihydro-9-oxa-10-phosphanenanthrene-10-oxide (manufactured by Sanko Co., Ltd., HCA) as a phosphoric acid-based antioxidant and phenol-based polymer solution were obtained. As an antioxidant, 0.1 parts by weight of pentaerythrityl-tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] (AO-60 manufactured by Asahi Denka Co., Ltd.) And 0.02 parts by weight were added.

  Next, the polymerization solution to which the antioxidant was added was converted into a vent type screw having a barrel temperature of 240 ° C., a rotation speed of 100 rpm, a degree of vacuum of 13.3 to 400 hPa (10 to 300 mmHg), a rear vent number of 1, and a forevent number of 4. It was introduced into a shaft extruder (Φ = 29.75 mm, L / D = 30) at a processing rate of 2.0 kg / hour in terms of resin amount, and further 19 parts by weight of CGL777MPAD (Ciba Specialty Chemicals) as UVA (B) A solution prepared by mixing 80 parts by weight of an active ingredient) and 11 parts by weight of toluene was pressure-injected at a rate of 0.06 kg / hour from an inlet before the third for vent to obtain a resin composition (D -3) was obtained. When calculated from the processing speed of the acrylic resin (A) and the injection speed of the UVA (B), the amount of UVA (B) added to the resin composition (D-3) is 100 parts by weight of the acrylic resin (A). (That is, 1.5 parts by weight with respect to 100 parts by weight of the thermoplastic resin contained in the composition (D-3)).

  In Example 3, the acrylic resin formed by the polymerization reaction has an N-substituted maleimide structure in the main chain.

Example 4
90 parts by weight of the glutarimide-containing acrylic resin used in Example 1, 10 parts by weight of acrylonitrile-styrene copolymer (manufactured by Asahi Kasei Chemicals Co., Ltd., Stylac AS783), and 4 parts by weight of TINUVIN 460 (Ciba) as UVA (B) A mixture with Specialty Chemicals Co., Ltd. was charged into the hopper, and the mixture was subjected to the twin-screw extruder used in Example 1 under conditions of a barrel temperature of 260 ° C., a rotation speed of 100 rpm, a degree of vacuum of 13 hPa, and a processing speed of 10 kg / hour. To obtain a resin composition (D-4). The amount of UVA (B) added in the resin composition (D-4) is 100 parts by weight of the thermoplastic resin (glutarimide-containing acrylic resin and acrylonitrile-styrene copolymer) contained in the composition (D-4). 4 parts by weight.

(Comparative Example 1)
A mixture of 100 parts by weight of the glutaric anhydride-containing acrylic resin used in Example 2 and 1.5 parts by weight of SUMISORB300 (manufactured by Sumitomo Chemical Co., Ltd.) as UVA was charged into the hopper, and the mixture was used in Example 1. In a twin-screw extruder, the resin composition (D-5) as a comparative example was obtained by melting under conditions of a barrel temperature of 260 ° C., a rotation speed of 100 rpm, a degree of vacuum of 13 hPa, and a processing speed of 10 kg / hour. The addition amount of UVA in the resin composition (D-5) is 1.5 parts by weight with respect to 100 parts by weight of the thermoplastic resin (glutaric anhydride-containing acrylic resin) contained in the composition (D-5).

  Note that SUMISORB300 is a benzotriazole-based ultraviolet absorber, and its structure is different from the structure represented by the above formula (3).

(Comparative Example 2)
90 parts by weight of the glutarimide-containing acrylic resin used in Example 1, 10 parts by weight of acrylonitrile-styrene copolymer (manufactured by Asahi Kasei Chemicals Co., Ltd., Stylac AS783), and 6 parts by weight of TINUVIN 460 (Ciba) as UVA (B) A mixture with Specialty Chemicals Co., Ltd. was charged into the hopper, and the mixture was subjected to the twin-screw extruder used in Example 1 under conditions of a barrel temperature of 260 ° C., a rotation speed of 100 rpm, a degree of vacuum of 13 hPa, and a processing speed of 10 kg / hour. To obtain a resin composition (D-6) as a comparative example. The addition amount of UVA (B) in the resin composition (D-6) is 6 parts by weight with respect to 100 parts by weight of the thermoplastic resin (glutarimide-containing acrylic resin) contained in the composition (D-6).

(Comparative Example 3)
Instead of a solution in which CGL777MPAD and toluene are mixed, a solution prepared by mixing 10 parts by weight of SUMISORB300 (manufactured by Sumitomo Chemical Co., Ltd.) and 10 parts by weight of toluene as UVA is injected under pressure into a polymerization solution to which an antioxidant is added. Except having carried out, it carried out similarly to Example 3, and obtained the resin composition (D-7) which is a comparative example. When calculated from the processing speed of the acrylic resin (A) and the UVA injection speed, the amount of UVA added to the resin composition (D-7) is 100 parts by weight of the acrylic resin (A) (that is, the composition). 1.5 parts by weight (with respect to 100 parts by weight of the thermoplastic resin contained in (D-7)).

  The results of evaluating the above properties for the resin composition samples of Examples 1 to 4 and Comparative Examples 1 to 3 are shown in Table 1 below. A resin film having a thickness of 100 μm was produced under the following extrusion conditions using a single-screw extruder having a cylinder diameter of 20 mm, a T-die having a width of 120 mm, and a roll for winding the formed film. Temperature 280 ° C., T die temperature 280 ° C., winding speed 2.5 m / min, roll temperature 110 ° C.

  As shown in Table 1, in each resin composition of the examples, UVA sublimation and scattering properties at the time of molding were achieved while realizing a high glass transition temperature, ultraviolet absorption ability and visible light transmittance equivalent to those of the comparative examples. It was able to suppress compared with the comparative example.

  Moreover, the turbidity change amount of the resin film formed from each resin composition of the Example was smaller than that of the resin film formed from each resin composition of the comparative example. In the resin films formed from the resin compositions of the examples, it is considered that UVA bleedout due to heat after film formation was suppressed as compared with the comparative example.

  According to the present invention, a thermoplastic resin composition containing an acrylic resin having a ring structure in the main chain and UVA, and the occurrence of bleeding out and the like is suppressed even during molding at a high temperature, and UVA is evaporated. Thus, it is possible to provide a resin composition in which the occurrence of problems due to the above is small.

  From the resin composition of the present invention, it is possible to produce a resin molded product having few defects due to bleed-out and the like, and having high ultraviolet absorption ability, heat resistance and transparency. The obtained resin molded product, for example, a resin film is an optical member. It can use suitably for the use as.

Claims (11)

100 parts by weight of a thermoplastic resin mainly composed of an acrylic resin having a ring structure represented by the following formula (1) and / or formula (2) in the main chain;
0.1 to 5 parts by weight of an ultraviolet absorber having a structure represented by the following formula (3),
A thermoplastic resin composition having a glass transition temperature of 110 ° C. or higher.

In the above formula (1), R ¹ and R ² are each independently a hydrogen atom or a methyl group, and X ¹ is an oxygen atom or a nitrogen atom. When X ¹ is an oxygen atom, R ³ does not exist, and when X ¹ is a nitrogen atom, R ³ is a hydrogen atom, a linear alkyl group having 1 to 6 carbon atoms, a cyclopentyl group, a cyclohexyl group, or a phenyl group. .
In the above formula (2), R ⁴ and R ⁵ are each independently a hydrogen atom or a methyl group, and X ² is an oxygen atom or a nitrogen atom. When X ² is an oxygen atom, R ⁶ does not exist, and when X ² is a nitrogen atom, R ⁶ is a hydrogen atom, a linear alkyl group having 1 to 6 carbon atoms, a cyclopentyl group, a cyclohexyl group, or a phenyl group. .
R ⁷ in the above formula (3) is a hydrogen atom or a group represented by the formula “—OR ¹¹ ”, and R ¹¹ is a hydrogen atom, an alkyl group having 1 to 18 carbon atoms or an alkyl ester group. R ^{8 to} R ¹⁰ in the above formula (3) are each independently a hydrogen atom, an alkyl group having 1 to 18 carbon atoms or an alkyl ester group. The thermoplastic resin composition according to claim 1, wherein R ⁷ in the formula (3) is a group represented by the formula “—OR ¹¹ ”. The thermoplastic resin composition according to claim 2, wherein R ¹¹ is a hydrogen atom.   The thermoplastic resin composition according to claim 1, further comprising a copolymer of a vinyl cyanide monomer and an aromatic vinyl monomer.   The thermoplastic resin composition according to claim 1, wherein the acrylic resin has a styrene unit as a constituent unit.   The resin molded product which consists of a thermoplastic resin composition in any one of Claims 1-5.   The resin molded product according to claim 6, which is a sheet or a film.   The polarizer protective film which consists of a thermoplastic resin composition in any one of Claims 1-5.   A polarizing plate comprising a polarizer and the polarizer protective film according to claim 8.   An image display device comprising the polarizing plate according to claim 9.   A method for producing a resin molded product, wherein the thermoplastic resin composition according to claim 1 is extruded to obtain a molded product.