JP2006299194A - (Meth) acrylic copolymer - Google Patents

Abstract

（式中、Ｘは、水素または炭素数１〜２０の炭化水素基を表し、ｎは、２以上２０以下のいずれかの整数を表す。）
【選択図】なし[PROBLEMS] As a material for a molded product that requires high-precision dimensional stability, such as an optical material or a sheet that warps due to water absorption, and a molded product that is used in an environment where water absorption and drying are repeated over a long period of time. To provide a novel (meth) acrylic copolymer having a suitable low water absorption.
A unit derived from a (meth) acrylic acid ester monomer (A) and a unit derived from an alicyclic methylene monomer (B) represented by the following general formula (I) (meth) Acrylic copolymer.
[Chemical 1]

(In the formula, X represents hydrogen or a hydrocarbon group having 1 to 20 carbon atoms, and n represents any integer of 2 or more and 20 or less.)
[Selection figure] None

Description

  The present invention relates to a (meth) acrylic copolymer obtained by polymerizing a (meth) acrylic acid ester monomer and an alicyclic methylene monomer.

  Methacrylic resins have properties that are balanced in mechanical strength, molding processability, weather resistance, and the like, and are used in various fields as sheet materials or molding materials. Furthermore, the methacrylic resin has excellent optical properties such as high transparency and low birefringence. Recently, taking advantage of these characteristics, disk materials such as video discs, audio discs, write-once discs for computers, lens materials for cameras, video cameras, projection televisions, optical pickups, etc., as well as various types of light such as optical fibers and optical connectors. Applications as transmission materials are expanding.

  However, methacrylic resins have a problem of high water absorption, and the molded product may undergo dimensional changes and warping due to water absorption, and cracks may occur when used in an environment where water absorption and drying are repeated over a long period of time. May occur, and its use is restricted depending on the application. In particular, applications that require high-precision dimensional stability, such as disk materials, optical pickup lenses and connectors used in those optical systems, and sheets where warpage due to water absorption is a problem, and water absorption and drying are repeated over a long period of time. The use is limited for molded products for applications under certain environments.

  Therefore, in recent years, many proposals have been made regarding techniques for improving water absorption while maintaining the optical properties of methacrylic resins. As a methacrylic resin having low water absorption, a copolymer of methyl methacrylate and cyclohexyl methacrylate (for example, see Patent Document 1), a method of forming a copolymer of methyl methacrylate, cyclohexyl methacrylate and benzyl methacrylate (for example, Patent Document 2) has been reported.

  Further, there is a method of introducing an olefin segment into the main chain as a method for reducing the water absorption of methacrylic acid ester, and a copolymer consisting of methacrylic acid ester / isobutene / maleimide has been proposed as a water-absorbing methacrylic acid ester copolymer. (For example, refer to Patent Document 3). An acryl-norbornene copolymer having a monomer-derived unit having a norbornene skeleton as an olefin segment has also been proposed (see, for example, Patent Document 4).

However, the above conventional method has the following problems. Copolymerization with cyclohexyl methacrylate cannot achieve water absorption as low as the method of introducing an olefin segment, and methacrylic acid in which an olefin segment is introduced into the main chain as a methacrylic acid ester copolymer having low water absorption. The copolymer of ester / isobutene / maleimide and the acrylic-norbornene copolymer having a monomer-derived unit having a norbornene skeleton as an olefin segment also contain maleic anhydride or maleimide as the monomer unit. There was a problem that water absorption was not significantly improved.
JP 58-5318 A Japanese Patent Laid-Open No. 58-13652 Japanese Patent Laid-Open No. 6-136058 Japanese Patent Laid-Open No. 4-63810

  The present invention has been made in order to solve the above-mentioned problems, and the object thereof is a molded product for applications requiring high-precision dimensional stability, such as a sheet in which warpage due to optical material or water absorption is a problem. Even if it is used, the molded product has dimensional stability, and it is suitable for use as a material that suppresses the occurrence of cracks even if it is used for molded products in applications where water absorption and drying are repeated over a long period of time. An object of the present invention is to provide a novel low water-absorbing (meth) acrylic copolymer that can be used.

  As a result of diligent research, the present inventors obtained knowledge that a copolymer obtained by polymerizing (meth) acrylic acid ester and a specific alicyclic methylene monomer has excellent low water absorption. Thus, the present invention has been made based on such findings.

  That is, the gist of the present invention includes a unit derived from a (meth) acrylic acid ester monomer (A) and a unit derived from an alicyclic methylene monomer (B) represented by the following general formula (I). The present invention relates to a (meth) acrylic copolymer.

(In the formula, X represents hydrogen or a hydrocarbon group having 1 to 20 carbon atoms, and n represents any integer of 2 or more and 20 or less.)

  The (meth) acrylic copolymer of the present invention is a novel (meth) acrylic copolymer with low water absorption, and has high dimensional stability such as optical materials and sheets that warp due to water absorption. Even if it is used for a molded product for the required application, the molded product has dimensional stability, and even if it is used for a molded product for an application in an environment where water absorption and drying are repeated over a long period of time, cracks and the like are generated. It can be suitably used as a material to be suppressed.

  The (meth) acrylic copolymer of the present invention includes a unit derived from a (meth) acrylic acid ester monomer (A) and an alicyclic methylene monomer (B) represented by the following general formula (I). If it contains the unit derived, it will not be restrict | limited in particular.

(Meth) acrylic acid ester monomer (A):
The unit derived from the (meth) acrylic acid ester monomer (A) in the (meth) acrylic copolymer of the present invention is obtained by copolymerizing the (meth) acrylic acid ester monomer (A) as a monomer. It is obtained. “(Meth) acrylic acid ester” represents an acrylic acid ester or a methacrylic acid ester.

  Although it does not specifically limit as said (meth) acrylic acid ester monomer (A), For example, methyl methacrylate (MMA), ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, methacryl Isobutyl acid, t-butyl methacrylate, isoamyl methacrylate, lauryl methacrylate, stearyl methacrylate, phenyl methacrylate, benzyl methacrylate, cyclohexyl methacrylate, glycidyl methacrylate, 2-ethylhexyl methacrylate, 4-tert-butyl methacrylate Cyclohexyl, tricyclodecanyl methacrylate, dicyclopentadienyl methacrylate, adamantyl methacrylate, trifluoroethyl methacrylate, tetrafluoropropyl methacrylate, methacrylic acid Methacrylates such as n-fluoropropyl, octafluoropentyl methacrylate, 2- (perfluorooctyl) ethyl methacrylate, methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate , Isobutyl acrylate, t-butyl acrylate, isoamyl acrylate, lauryl acrylate, phenyl acrylate, benzyl acrylate, cyclohexyl acrylate, glycidyl acrylate, 2-ethylhexyl acrylate, 4-tert-butylcyclohexyl acrylate, Acrylic acid esters such as tricyclodecanyl acrylate, dicyclopentadienyl acrylate, adamantyl acrylate, and the like can be exemplified, but the invention is not limited thereto. These can be used alone or in combination of two or more.

  The content of the (meth) acrylic acid ester monomer (A) unit in the acrylic copolymer of the present invention is appropriately set according to the properties of the desired resin, but is in the range of 50 to 99 mol%. It is preferable that the range is 60 to 95 mol%. If the content of the (meth) acrylic acid ester monomer (A) unit in the copolymer is 50 mol% or more, good mechanical strength can be obtained in the molded product, and if it is 60 mol% or more. The above effects can be obtained more remarkably. Further, if the content of the (meth) acrylic acid ester monomer (A) unit is 99 mol% or less, the water absorption in the molded product can be reduced, and if it is 95 mol% or less, the above effect is more remarkable. Can get to.

Alicyclic methylene monomer (B):
The unit derived from the alicyclic methylene monomer (B) represented by the general formula (I) in the (meth) acrylic copolymer of the present invention is represented by the general formula (I).

It is a unit obtained by copolymerizing the alicyclic methylene monomer (B) shown by the above as a monomer. In formula (I), X represents hydrogen or a hydrocarbon group having 1 to 20 carbon atoms, and n represents any integer of 2 or more and 20 or less. From the viewpoint of availability of the monomer, the effect of improving water absorption, and the thermal mechanical properties, n preferably represents any integer of 3 to 12. Examples of the hydrocarbon group having 1 to 20 carbon atoms include methyl group, ethyl group, normal propyl group, isopropyl group, normal butyl group, isobutyl group, t-butyl group, normal propyl group, normal hexyl group, normal heptyl group, and normal. Octyl group, normal nonyl group, normal decanyl group, 2-ethylhexyl group, cyclopentyl group, cyclohexyl group, methylcyclohexyl group, dimethylcyclohexyl group, trimethylcyclohexyl group, t-butylcyclohexyl group, etc. X is preferably hydrogen or a methyl group from the viewpoint of easy availability of the body, water absorption improvement effect, or thermal mechanical properties. Specific examples of the alicyclic methylene monomer (B) represented by the general formula (I) include methylenecyclopropane, methylenecyclobutane, methylenecyclopentane, methylenecyclohexane, methylenecycloheptane, methylenecyclooctane, and methylene. Monocyclic alicyclic methylene compounds such as cyclononane, methylenecyclodecane, and methylenecyclododecane; 2-methylenebicyclo [2.2.1] heptane, (+)-camphene, (−)-camphene, β-pinene, etc. Bicyclic alicyclic methylene compounds; Tricyclic alicyclic methylene compounds such as methylene adamantane; 3-methylenetetracyclo [4.4.0.1 ^2.5 . 1 ^7.10 ] and tetracyclic alicyclic methylene compounds such as dodecane. These can be used alone or in combination of two or more. Among these, methylenecyclobutane, methylenecyclopentane, methylenecyclohexane, 2-methylenebicyclo [2.2.1] heptane from the viewpoint of availability of monomers, the effect of improving water absorption, and thermal mechanical properties. , (+)-Camphene, (−)-camphene, β-pinene, and methylenetetracyclododecane are preferred.

  The content of the alicyclic methylene monomer (B) unit in the (meth) acrylic copolymer of the present invention is preferably in the range of 1 to 50 mol%, and in the range of 5 to 40 mol%. Is more preferable. If the content of the alicyclic methylene monomer (B) unit in the (meth) acrylic copolymer is 50 mol% or less, good mechanical strength can be obtained in the molded product, and it should be 40 mol% or less. The above effects can be obtained more remarkably. Moreover, if content of an alicyclic methylene monomer (B) unit is 1 mol% or more, a water absorption can be reduced in a molded article, and if it is 5 mol% or more, the said effect will be acquired more notably. be able to.

Copolymerizable monomer (C):
The (meth) acrylic copolymer of the present invention is further provided with a third configuration derived from another copolymerizable monomer (C) depending on the use, moldability, and other quality requirements as required. It may contain units.

  Examples of the other copolymerizable monomer (C) copolymerized to obtain the third structural unit include ethylene, propylene, 1-butene, 2-butene, isobutene, 1-pentene, 3- Linear or branched chain olefins such as methyl-1-butene, 1-hexene, 4-methyl-1-pentene, 3-methyl-1-pentene, 1-octene; cyclopentene, cycloheptene, norbornene, 5 -Methyl-2-norbornene, tetracyclododecene, 2-methyl-1,4,5,8-dimethano-1,2,3,4,4a, 5,8,8a-octahydronaphthalene, vinylnorbornene, di Cyclic olefins (cycloalkenes) such as cyclopentadiene; fumaric acid, maleic anhydride, itaconic acid, itaconic anhydride, bicyclo [2.2.1] -5-hept Α, β-unsaturated carboxylic acid and its anhydride such as dimethyl-2,3-dicarboxylic acid anhydride; dimethyl fumarate, diethyl fumarate, diisopropyl fumarate, dicyclohexyl fumarate, dimethyl maleate, diethyl maleate, itacon Α, β-unsaturated carboxylic acid esters such as dimethyl acid and diethyl itaconate; maleimides such as maleimide, methylmaleimide, ethylmaleimide, cyclohexylmaleimide, and phenylmaleimide; vinyl caprate, vinyl laurate, vinyl stearate, Vinyl esters such as vinyl trifluoroacetate; dienes such as butadiene, isoprene, 4-methyl-1,3-pentadiene, 1,3-pentadiene; styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene O, p-Dimethyls It can rise the aromatic vinyl compounds such as mono- or polyalkyl styrene Len like.

  The content of the third structural unit in the (meth) acrylic copolymer of the present invention is preferably 20 mol% or less. If content of a 3rd structural unit is 20 mol% or less, the fall of light resistance can be suppressed.

  The number average molecular weight of the (meth) acrylic copolymer of the present invention is preferably 5,000 to 500,000. If the number average molecular weight is 5000 or more, it has good mechanical strength, and if it is 500,000 or less, it is possible to suppress a decrease in moldability.

Production of (meth) acrylic copolymer:
The (meth) acrylic copolymer of the present invention comprises the above (meth) acrylic acid ester monomer (A), the alicyclic methylene monomer (B) represented by the general formula (I), and if necessary. These can be produced by polymerizing the copolymerizable monomer (C). There is no restriction | limiting in particular as a polymerization method in this invention, A well-known polymerization method is employable. For example, a thermal radical polymerization method, a photo radical polymerization method, an ionic polymerization method, a coordination ion polymerization method, a photo cation polymerization method and the like can be mentioned. A radical polymerization method such as a photo radical polymerization method is preferred. As a polymerization form, a known polymerization form can be employed, and for example, bulk polymerization, suspension polymerization, emulsion polymerization, solution polymerization using an appropriate solvent, slurry polymerization, and the like can be employed.

  When the (meth) acrylic copolymer of the present invention is produced by radical polymerization, a known radical polymerization initiator generally used in radical polymerization can be used as the radical polymerization initiator to be used. For example, peroxide initiators such as benzoyl peroxide, di-t-butyl peroxide, isobutyl peroxide, 2,2′-azobisisobutyronitrile, 2,2′-azobis-2,4-dimethylvalero Examples thereof include azo initiators such as nitrile, 2,2′-azobis- (4-methoxy-2,4-dimethylvaleronitrile), and 2,2′-azobis-2-methylbutyronitrile. Of these, benzoyl peroxide, 2,2′-azobisisobutyronitrile, 2,2′-azobis-2,4-dimethylvaleronitrile, 2,2′-azobis- (4-methoxy-2, 4-dimethylvaleronitrile) and the like, but are not limited thereto.

  The amount of these radical polymerization initiators used is preferably 0.00001 to 10 parts by weight, more preferably 0.001 to 100 parts by weight based on 100 parts by weight of the monomer used for the production of the (meth) acrylic copolymer. 0001 to 1 part by weight.

  When manufacturing the (meth) acrylic-type copolymer of this invention by radical polymerization, it is preferable to use a Lewis' acid compound (D) as needed. As a Lewis acid compound (D) used for manufacture of the (meth) acrylic-type copolymer of this invention, an organoaluminum compound (D-1), an organoaluminum oxy compound (D-2), and ionization ionicity, for example. The compound which combined 1 type (s) or 2 or more types chosen from a compound (D-3) can be mentioned.

  A known organoaluminum compound can be used as the organoaluminum compound (D-1). An organoaluminum compound having a structure represented by the following formula (II) is preferable.

E ¹ _a AlZ _(3-a) (II)
In formula (II), E ¹ represents a hydrocarbon group having 1 to 8 carbon atoms, preferably an alkyl group, Z represents hydrogen or halogen, and a represents an integer of 1 to 3. When a represents 2 or 3, all of the plurality of E ¹ may be the same or different from each other, and when a represents 1, the two Z are the same or different from each other May represent things.

  Examples of the organoaluminum compound (D-1) represented by the formula (II) include trialkylaluminum such as trimethylaluminum, triethylaluminum, tripropylaluminum, triisobutylaluminum, trihexylaluminum; dimethylaluminum chloride, diethylaluminum chloride, Dialkylaluminum chlorides such as dipropylaluminum chloride, diisobutylaluminum chloride, dihexylaluminum chloride; alkylaluminum dichlorides such as methylaluminum dichloride, ethylaluminum dichloride, propylaluminum dichloride, isobutylaluminum dichloride, hexylaluminum dichloride; dimethylaluminum hydride, di Chill aluminum hydride, may be mentioned dipropyl aluminum hydride, diisobutyl aluminum hydride, dialkyl aluminum hydride such as dihexyl aluminum hydride. Among these, alkyl aluminum dichloride is preferable, and ethyl aluminum dichloride, propyl aluminum dichloride, and isobutyl aluminum dichloride are more preferable.

As the organoaluminum oxy compound (D-2), a known organoaluminum oxy compound can be used, and preferably the formula (III)
[—Al (E ² ) —O—] _b (III)
Cyclic aluminoxane (D-2-1) represented by the formula (IV)
E ³ [—Al (E ³ ) —O—] _c AlE ³ ₂ (IV)
The linear aluminoxane (D-2-2) shown by these can be mentioned.

In the formula (III) representing the cyclic aluminoxane (D-2-1), E ² is a hydrocarbon group having 1 to 8 carbon atoms, preferably an alkyl group, more preferably a methyl group, an ethyl group, a normal propyl group, or isopropyl. Represents a group, a normal butyl group, an isobutyl group, a normal pentyl group or a neopentyl group, more preferably a methyl group or an isobutyl group. All E ² may be the same or different from each other. In the formula (III), b represents an integer of 2 or more, preferably any integer of 2-40.

In formula (IV) representing linear aluminoxane (D-2-2), E ³ is a hydrocarbon group having 1 to 8 carbon atoms, preferably an alkyl group, more preferably a methyl group, an ethyl group, a normal propyl group, It represents an isopropyl group, a normal butyl group, an isobutyl group, a normal pentyl group or a neopentyl group, more preferably a methyl group or an isobutyl group. All E ³ may be the same or different from each other. In formula (IV), c represents an integer of 1 or more, preferably any integer of 1 to 40.

As the ionized ionic compound (D-3), formula (V)
J ⁺ (BQ ¹ Q ² Q ³ Q ⁴ ) ^- (V)
A boron compound (D-3-1) represented by formula (VI)
(L-H) ⁺ (BQ ⁵ Q ⁶ Q ⁷ Q ⁸ ) ^- (VI)
The boron compound (D-3-2) shown by can be mentioned.

In the formula (V) representing the boron compound (D-3-1), B represents a tetravalent boron atom, and Q ¹ , Q ² , Q ^3, and Q ⁴ are each bonded to the boron atom. , A halogen atom, a hydrocarbon group having 1 to 20 carbon atoms, a halogenated hydrocarbon group having 1 to 20 carbon atoms, a hydrocarbon-substituted silyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, or 2 carbon atoms Represents a disubstituted amino group of ˜20, and the groups represented by Q ^{1 to} Q ⁴ may be the same or one or more of them may be different. Q ^{1 to} Q ⁴ each preferably represent a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms, or a halogenated hydrocarbon group having 1 to 20 carbon atoms. In the formula (V), examples of the anion represented by (BQ ¹ Q ² Q ³ Q ⁴ ) ⁻ include tetrakis (pentafluorophenyl) borate, tetrakis (2,3,5,6-tetrafluorophenyl) borate, tetrakis (2,3,4,5-tetrafluorophenyl) borate, tetrakis (3,4,5-trifluorophenyl) borate, tetrakis (2,2,4-trifluorophenyl) borate, phenyltris (pentafluorophenyl) Examples thereof include borates and tetrakis (3,5-bistrifluoromethylphenyl) borate.

In the formula (V), J ⁺ represents an inorganic or organic cation. Examples of the inorganic cation represented by J ⁺ include a ferrocenium cation, an alkyl-substituted ferrocenium cation, and a silver cation. Examples of the organic cation include a triphenylmethyl cation.

  Examples of the boron compound (D-3-1) represented by the formula (V) include ferrocenium tetrakis (pentafluorophenyl) borate, 1,1′-dimethylferrocenium tetrakis (pentafluorophenyl) borate, Examples thereof include silver tetrakis (pentafluorophenyl) borate, triphenylmethyltetrakis (pentafluorophenyl) borate and triphenylmethyltetrakis (3,5-bistrifluoromethylphenyl) borate. Among these, triphenylmethyltetrakis (pentafluorophenyl) borate is preferable.

In the formula (VI) showing the boron compound (D-3-2), B represents a tetravalent boron atom, and Q ⁵ , Q ⁶ , Q ⁷ and Q ⁸ are each a boron atom. Bonded, a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms, a halogenated hydrocarbon group having 1 to 20 carbon atoms, a hydrocarbon-substituted silyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, or carbon represents a 2-substituted amino group having 2 to 20, Q ⁵ group to Q ⁸ represents may be different one or more may be the same all. Q ^{5 to} Q ⁸ each preferably represent a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms, or a halogenated hydrocarbon group having 1 to 20 carbon atoms. In the formula (VI), L represents a neutral Lewis base, and (L—H) ⁺ represents a Bronsted acid. Examples of the Bronsted acid represented by (L—H) ^{+ in} formula (VI) include trialkyl-substituted ammonium, N, N-dialkylanilinium, dialkylammonium, and triarylphosphonium. In the formula (VI), examples of the anion represented by (BQ ⁵ Q ⁶ Q ⁷ Q ⁸ ) ⁻ include, for example, (BQ ¹ Q ² Q in the formula (V) representing the boron compound (D-3-1). ³ Q ^{4) -} identical between those exemplified as the like.

  Examples of the boron compound (D-3-2) represented by the formula (VI) include triethylammonium tetrakis (pentafluorophenyl) borate, tripropylammonium tetrakis (pentafluorophenyl) borate, tri (normal butyl) ammonium tetrakis. (Pentafluorophenyl) borate, tri (normal butyl) ammonium tetrakis (3,5-bistrifluoromethylphenyl) borate, N, N-dimethylanilinium tetrakis (pentafluorophenyl) borate, N, N-diethylanilinium tetrakis ( Pentafluorophenyl) borate, N, N-2,4,6-pentamethylanilinium tetrakis (pentafluorophenyl) borate, N, N-dimethylanilinium tetrakis (3,5-bi Trifluoromethylphenyl) borate, diisopropylammonium tetrakis (pentafluorophenyl) borate, dicyclohexylammonium tetrakis (pentafluorophenyl) borate, triphenylphosphoniumtetrakis (pentafluorophenyl) borate, tri (methylphenyl) phosphoniumtetrakis (pentafluorophenyl) Examples thereof include borate and tri (dimethylphenyl) phosphonium tetrakis (pentafluorophenyl) borate. Among these, tri (normal butyl) ammonium tetrakis (pentafluorophenyl) borate or N, N-dimethylanilinium tetrakis (pentafluorophenyl) borate is preferable.

  The amount of the Lewis acid compound used is preferably 0.001 to 10 moles, more preferably 0.001 to 2 moles, with respect to 1 mole of the (meth) acrylic acid ester monomer. Although depending on the kind of the Lewis acid compound, the copolymerization ratio of the alicyclic methylene monomer (B) can be arbitrarily controlled between 1 and 50 mol% depending on the amount of the Lewis acid compound used. When the amount of the Lewis acid compound used is 10 mol or less with respect to 1 mol of the (meth) acrylic acid ester monomer, a decrease in transparency due to the organoaluminum compound residue contained in the copolymer is suppressed, and 2 mol or less. If so, such an effect can be remarkably obtained. Moreover, if the usage-amount of a Lewis acid compound is 0.001 mol or more with respect to 1 mol of (meth) acrylic acid ester monomers, the copolymerization of an alicyclic methylene monomer (B) will not be inhibited.

  When the (meth) acrylic copolymer of the present invention is produced using a solvent by radical polymerization, examples of the solvent used include various solvents that do not deactivate the radical polymerization initiator and the Lewis acid. For example, hydrocarbons such as benzene, toluene, o, m, p-xylene, pentane, hexane, cyclohexane; halogenated hydrocarbons such as chloroform, dichloromethane, ethylene dichloride, chlorobenzene, benzonitrile, acetonitrile, 1,4-dioxane , Tetrahydrofuran, dimethyl sulfoxide, dimethylformamide and the like.

  About superposition | polymerization temperature, -50-200 degreeC is preferable and 0-150 degreeC is more preferable.

  In the radical polymerization, other known chain transfer agents such as mercaptan compounds, α-methylstyrene dimers, terpenoid compounds, etc. may be added to adjust the molecular weight of the (meth) acrylic copolymer of the present invention. .

  The (meth) acrylic copolymer of the present invention is provided with a deterioration inhibitor such as an antioxidant or an ultraviolet absorber, a plasticizer, a stabilizer, a thickener, a tackifier resin, etc. when used for various purposes. Further, from the viewpoint of being an olefin resin to which a polar group is added, a colorant, a pigment, an extender, and the like can be contained.

  The (meth) acrylic copolymer of the present invention utilizes its excellent transparency, low water absorption, etc. to provide elastomers, transparent heat-resistant resins, sheets, films in the electric / electronic field, automobile field, medical field, etc. , Tubes, hoses, optical materials, sealants, adhesives, adhesives, sealants, paints, coating agents, automotive parts, electrical parts, aerospace parts, electronic parts, battery parts, electronics-related parts, multimedia-related It is useful as a material for various molded products and parts such as parts. Furthermore, from the viewpoint of being an olefin resin with a polar group added, by adding it to thermoplastic resins such as polyolefin resins, thermosetting resins, etc., impact resistance, paintability, printing of these resins It is also possible to improve suitability, weather resistance and the like. Furthermore, it can also be used as a compatibilizing agent between different resins such as a compatibilizing agent for polyolefin resins and acrylic resins, and an adhesion improving agent.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, the technical scope of this invention is not limited to these Examples.

The copolymer composition of the polymers obtained in the examples was determined by ¹ H-NMR (JNM-EX270, manufactured by JEOL Ltd.). The number average molecular weight and molecular weight distribution (Mw / Mn) were measured by GPC (product of Waters, GPC150C) using polymethyl methacrylate as a standard (chloroform, 40 ° C.).

The water absorption was determined by measuring the weight increase after standing in water at 25 ° C. for 24 hours using the obtained polymer cast film, and calculating the water absorption by the following formula.
Water Absorption Rate (%) = Water Absorption Weight × 100 / Polymer Weight [Example 1]
1.0 g (10 mmol) of methyl methacrylate was added into a 100 mL flask substituted with argon, and cooled to -78 ° C. To this was added dropwise 1.25 mL of toluene, followed by 3.0 mL (5.4 mmol) of 1.8 M toluene solution of ethylaluminum dichloride, and then the solution was raised to room temperature and stirred for 30 minutes.

  After stirring, the mixture was cooled again to −78 ° C., and 0.96 g (10 mmol) of methylenecyclohexane and 10 mg of 2,2′-azobisisobutyronitrile were added. Copolymerization was carried out by stirring at 70 ° C. for 12 hours.

Thereafter, the reaction solution was poured into a mixture of 10 mL of 1N hydrochloric acid and 100 mL of methanol, and the precipitate was filtered to obtain a white solid. This white solid was washed with 1N hydrochloric acid and methanol and dried under reduced pressure to obtain a copolymer (yield 34 mass%). A 0.4 g / mL chloroform solution of this copolymer was prepared, and a cast film was prepared on a Teflon sheet (film thickness 180 μm). The cast film was about 1 cm ² , vacuum-dried at 70 ° C. for 24 hours, and used for the water absorption test.

Table 1 shows the copolymerization ratio, number average molecular weight, molecular weight distribution, and water absorption rate of the film produced.
[Example 2]
A copolymer was obtained by copolymerizing in the same manner as in Example 1 except that 0.82 g (10 mmol) of methylenecyclopentane was used instead of methylenecyclohexane in Example 1, and the yield was 20% by mass. A film (thickness: 160 μm) was prepared in the same manner as in Example 1.

The copolymerization ratio, number average molecular weight, molecular weight distribution, and water absorption rate of the obtained copolymer were measured in the same manner as in Example 1. The results are shown in Table 1.
[Example 3]
A copolymer was obtained by copolymerizing in the same manner as in Example 1 except that 1.68 g (10 mmol) of cyclohexyl methacrylate was used instead of methyl methacrylate in Example 1 (yield 38 mass%). ), And a film (thickness: 160 μm) was prepared in the same manner as in Example 1.

The copolymerization ratio, number average molecular weight, molecular weight distribution, and water absorption rate of the obtained copolymer were measured in the same manner as in Example 1. The results are shown in Table 1.
[Example 4]
In Example 1, instead of methyl methacrylate, 0.8 g (8 mmol) of methyl methacrylate and 0.17 g (2 mmol) of methyl acrylate were used, and copolymerization was carried out by copolymerization in the same manner as in Example 1. A coalescence was obtained (yield 39% by mass), and a film (thickness: 145 μm) was prepared in the same manner as in Example 1.

The copolymerization ratio, number average molecular weight, molecular weight distribution, and water absorption rate of the obtained copolymer were measured in the same manner as in Example 1. The results are shown in Table 1.
[Comparative Example 1]
Methyl methacrylate 2.0 mL (20 mmol), toluene 4.25 mL, and 2,2′-azobisisobutyronitrile 10 mg were added to a 100 mL flask purged with argon. Polymerization was carried out by stirring at 65 ° C. for 24 hours.

  Thereafter, the reaction solution was poured into a mixture with 100 mL of methanol, and the precipitate was filtered to obtain a white solid. This white solid was washed with methanol and dried under reduced pressure to obtain a polymer (yield 64% by mass). A 0.4 g / mL chloroform solution of this copolymer was prepared, and a cast film was formed on a Teflon sheet (film thickness 160 μm).

The copolymerization ratio, number average molecular weight, molecular weight distribution, and water absorption rate of the obtained copolymer were measured in the same manner as in Example 1. The results are shown in Table 1.
[Comparative Example 2]
A copolymer was obtained by copolymerizing in the same manner as in Example 1 except that the 1.8M toluene solution of ethylaluminum dichloride used in Example 1 was not used (yield: 58% by mass).

  The copolymerization ratio, number average molecular weight, molecular weight distribution, and water absorption rate of the obtained copolymer were measured in the same manner as in Example 1. The results are shown in Table 1.

Abbreviation: MMA methyl methacrylate CHMA cyclohexyl methacrylate MA methyl acrylate

Claims (4)

A (meth) acrylic copolymer containing a unit derived from a (meth) acrylic acid ester monomer (A) and a unit derived from an alicyclic methylene monomer (B) represented by the following general formula (I) Coalescence.

(In the formula, X represents hydrogen or a hydrocarbon group having 1 to 20 carbon atoms, and n represents any integer of 2 or more and 20 or less.) It has 50 to 99 mol% of units derived from the (meth) acrylic acid ester monomer (A), and has 1 to 50 mol% of units derived from the alicyclic methylene monomer (B). (Meth) acrylic copolymer. The (meth) acrylic copolymer according to claim 1 or 2 obtained by radical polymerization. The (meth) acrylic copolymer according to claim 3, which is obtained by radical polymerization in the presence of the Lewis acid compound (D).