JPS62256806A - Acrylic random copolymer and thermosetting resin composition containing said copolymer - Google Patents

Abstract

PURPOSE:To obtain an acrylic random copolymer which, when added to a thermosetting resin, can impact flexibility to the resin without detriment to its strength, by copolymerizing two specified alpha,beta-unsaturated compounds with a copolymerizable acrylate monomer, etc. CONSTITUTION:The title copolymer comprising 1-30wt% carboxyl group- containing alpha,beta-unsaturated compound component units (A) of formula I (wherein R<1> is hydrogen or methyl, R<2> is a 2-6C alkylene and R<3> is phenylene or the like), 1-20wt% methylol group-containing alpha,beta-unsaturated compound component units of formula II (wherein X is H or a 1-6C alkyl) and/or epoxy group- containing alpha,b-unsaturated compound components units (b) of formula III (wherein Y is a 1-6C alkylene) and 98-50wt% 4-16C alkyl (meth)acrylate component units and/or alkoxy (meth)acrylate component units (C) copolymerizable with components A and B and having weight-average MW (in terms of polystyrene) of 1,000-30,000.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an acrylic random copolymer suitable for thermosetting resin blends and to the adhesion between metal and polar resin using the copolymer. The present invention relates to suitable thermosetting resin compositions.

[Conventional technology]

-S, thermosetting resins such as epoxy resins and phenolic resins have low curing shrinkage, excellent dimensional stability, strong mechanical strength, and excellent electrical properties as insulators, as well as heat resistance, water resistance, Flexible printed circuit boards that are excellent in many aspects such as chemical resistance, and have a basic structure of bonding metal, porcelain, concrete, or even base materials with copper foil, especially when used as adhesives, paints, coatings, etc. It has strong adhesive strength, adhesion strength, and mechanical strength, as well as excellent shear strength and tensile strength.

However, such thermosetting resins lack flexibility, so when used as adhesives, coatings, paints, etc., their peel strength and impact strength are extremely low, causing cracks and peeling. The problem is that it is easy to do.

In addition, when using thermosetting resin as a molding material,
There is a problem in that the molded product is brittle and easily destroyed due to various types of curvature.

Conventionally, as a method to improve the brittleness of thermosetting resins such as epoxy resins and phenolic resins, for example, taking the following epoxy resin as a thermosetting resin, The use of various materials such as nitrile rubber is being considered.

On the other hand, in recent years, as electronic and electrical equipment has become smaller and lighter,
Flexible printed circuit boards are showing remarkable growth for the purpose of saving space for various wiring types. The basic structure of a flexible print board is a base material and a single foil bonded together, and a thermosetting resin is used for adhesion between them due to its properties such as heat resistance and electrical insulation. Furthermore, epoxy resin or phenol resin mixed with rubber to impart flexibility is used.

However, the simple blending of rubber, while imparting flexibility, causes a decrease in adhesive strength, and also has the disadvantage that phase separation between the resin and rubber occurs at high temperatures, resulting in separation of the rubber component.

On the other hand, carboxyl groups, epoxy groups,
Attempts have also been made to solve the above problem by using a rubber having a functional group such as a hydroxyl group and causing the functional group to react with a thermosetting resin. In this case, if the reaction between the functional groups of the rubber and the thermosetting resin is sufficient, adhesion and phase separation between the resin and the rubber can be improved, but gelation of the blend occurs and the viscosity The increase is significant and the workability when used as an adhesive is reduced.

Furthermore, if the reaction between the functional groups of the rubber and the thermosetting resin is insufficient, the effect of improving adhesion and preventing phase separation cannot be obtained, and the problem cannot be solved.

[Problem that the invention seeks to solve]

The present invention has been made against the background of the above-mentioned conventional technical problems, and solves the problem that flexibility cannot be sufficiently improved in conventional means for modifying thermosetting resins such as epoxy resins and phenolic resins. While maintaining the excellent mechanical strength that is characteristic of thermosetting resins, it is possible to significantly improve flexibility, thus providing excellent peel strength and impact strength in addition to mechanical strength. Flexible vinyl for thermosetting resins that can produce thermosetting resins, does not cause gelation when reacted with thermosetting resins, and does not cause viscosity increase when used as an adhesive, and has good workability. The object of the present invention is to provide a novel acrylic copolymer that can be used as a riser and a thermosetting resin composition using the same.

[Means for solving problems]

That is, the present invention provides (A) a carboxyl group-containing α,β-unsaturated compound component represented by general formula (1) at flower positions 1 to 3;
0% by weight, 0... (1) (In the formula, R1 is a hydrogen atom or a methyl group, R2 is an alkylene group having 2 to 6 carbon atoms, R3 is a phenylene group, cyclohexylene group, or a carbon number 2 group. ~6 alkylene group or a divalent unsaturated hydrocarbon group having 2 to 6 carbon atoms), (B) a methylol group-containing α, β-unsaturated compound component unit represented by the general formula (n), and / or epoxy group-containing α, β-unsaturated compound component unit 1 represented by the general formula (I[[)
20% by weight, R'X i / C11□ = C-CoN ・ ・ ・ ・
・ ・ ・ (■) CH2O,8 (In the formula, R1 is the same as above, and X represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.) (In the formula, R1 is the same as above, and Y is the number of carbon atoms. 1 to 6 alkylene groups.) (C) C4 to C16 alkyl (meth)acrylate component unit and/or alkoxy (meth)acrylate component unit copolymerizable with the components (A) and (B). 50 to 98% by weight, and (D) the above (A), (B
) and 0 to 30% by weight of other monomer component units copolymerizable with component (C), and has a weight average molecular weight in terms of polystyrene of 1,000 to 30,000. Provided is a thermosetting resin composition characterized in that an acrylic random copolymer, and further (a) the above-mentioned acrylic random copolymer is blended with (b) a thermosetting resin (Prevo" J-mer). It is something to do.

First, the novel acrylic copolymer of the present invention will be explained.

That is, the carboxyl group-containing α,β-unsaturated compound of the S-mer (A) component constituting this copolymer is a compound represented by the above general formula (1), and is a preferable compound in the cough formula. R2 is an ethylene group, (iso)propylene group, butylene group, or hexylene group. In addition, when the number of carbon atoms in R2 is 1 or 7 or more, the above general formula (1)
It is difficult to prepare the diol compound used in the synthesis of the compound.

In addition, preferable R3 in the formula is a phenylene group,
They are cyclohexylene group, ethylene group, butylene group, and hexylene group. Note that if the number of carbon atoms in R3 is 1 or 7 or more, it is difficult to obtain the dicarboxylic acid compound used for synthesizing the compound of the general formula ([).

Such carboxyl group-containing α. Examples of the β-unsaturated compounds include the following.

CH.

[Succinic acid mono-(methacrylooxyethyl) ester], CH.

[Maleic acid mono-(methacrylooxyethyl) ester], [phthalic acid mono-(methacrylooxyethyl) ester], [hexahydrophthalic acid mono-(methacrylooxyethyl) ester], succinic acid mono-( acrylooxyethyl) ester, maleic acid mono(acrylooxyethyl) ester, phthalic acid mono-(acrylooxyethyl) ester, hexahydrophthalic acid mono-(acrylooxyethyl) ester
ester, succinic acid mono-(meth)acryloxypropyl ester, maleic acid mono-(meth)acryloxypropyl ester, phthalic acid mono-(meth)acryloxypropyl ester, hexahydrophthalic acid mono-(meth) Acryloxypropyl ester, Adipic acid mono-(meth)acryloxyethyl ester, Malonic acid mono-(meth)acryloxyethyl ester, Adipic acid mono-(meth)acryloxypropyl ester, Malonic acid mono-( meth)acryloxypropyl ester.

Carboxyl group-containing α, β-unsaturated compound component unit (A
) are mainly repeated as follows.

(In the formula, R1, R2, and R3 are the same as above) The content of component (A) is 1 to 30% by weight, preferably 2 to 20% by weight.
If it is less than 1% by weight, the compatibility with the thermosetting resin prepolymer is insufficient, and the adhesiveness and strength of the thermosetting resin composition containing the copolymer of the present invention are insufficient, especially when thermosetting. This tendency is strong when a phenolic resin initial condensate is used as the phenolic resin prepolymer. On the other hand, if it exceeds 30% by weight, the viscosity after mixing with the thermosetting resin prepolymer will increase, making it extremely difficult to handle, and the flexibility of the resulting resin composition will decrease.

Note that such a carboxyl group-containing α. The β-unsaturated compound includes the corresponding (meth)acrylooxydialkanol constituting the compound, succinic acid, maleic acid, phthalic acid,
Dicarboxylic acid compounds such as hexahydrophthalic acid, adipic acid or malonic acid #! ! A (hereinafter referred to as "dicarboxylic acid compound") in accordance with a conventional method, for example, 1 mole of (meth)acrylooxydialkanol and 1 mole of dicarboxylic acid compound are mixed with toluene, using an acid such as sulfuric acid or p-toluenesulfonic acid as a catalyst. Hensen, xylene, octane, etc. are used as organic solvents under reflux (e.g. 80-150°C).
), can be easily produced by reacting for 5 to 10 hours.

Furthermore, the methylol group- or epoxy group-containing α,β-unsaturated compound of the monomer (B) component constituting the copolymer of the present invention refers to a compound represented by the general formula (1) or (n) above. Preferably, X in the formula is a hydrogen atom or a methyl group, and Y is preferably a methylene group or an ethylene group.

When X and Y have 7 or more carbon atoms, the copolymerizability of the monomers decreases, which is not preferable.

Methylol group-containing α represented by general formula (II).

Examples of the β-unsaturated compound include acrylamide derivatives such as N-methylol (meth)acrylamide, N-methylol, N-methyl (meth)acrylamide, N-methylol, and N-ethyl (meth)acrylamide.

Further, examples of the epoxy group-containing α,β-unsaturated compound represented by the general formula (III) include glycidyl (meth)acrylate, 4-(meth)acryloyloxybutylene oxide, 5-(meth)acryloyloxy Examples include epoxy group-containing lt-isomers such as pentene oxide and acryloylcyclohexene oxide.

These methylol group- or epoxy group-containing α. β−
The unsaturated compounds can be used alone or in combination of two or more.

The repeating units of the methylol group- or epoxy group-containing α,β-unsaturated compound component unit (B) are mainly as follows.

(In the formula, R' and X are the same as above.) (In the formula, R1,
Y is the same as above. ) The content of component (B) is 1 to 20% by weight, preferably 2% by weight.
~15% by weight, and if it is less than 1% by weight, the self-curing properties of the copolymer of the present invention are insufficient, and the copolymer is blended with a thermosetting resin prepolymer to form a composition and cured. However, if the content exceeds 20%, the self-curing properties of the copolymer are sufficient, but the copolymer becomes resistant to heat and light. The copolymer itself becomes unstable, causing storage problems, and the copolymer itself becomes poor in rubber elasticity due to excessive curing.

The alkyl (meth)acrylate and/or alkoxy (meth)acrylate as the monomer (C) component constituting the copolymer of the present invention has 4 to I6 carbon atoms, and if it is 17 or more, (A) The copolymerization reactivity with the component and component (B) is poor, which is not preferable.

Examples of the monomer (C) component include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, 2- Alkyl (meth)acrylates such as ethylhexyl (meth)acrylate, octyl (meth)acrylate, nonyl (meth)acrylate, nonyl (meth)acrylate, decyl (meth)acrylate, cyanoethyl (meth)acrylate; also methoxyethyl (meth)acrylate Examples include alkoxy(meth)acrylates such as acrylate, ethoxyethyl(meth)acrylate, butoxyethyl(meth)acrylate, and ethoxypropyl(meth)acrylate.

These alkyl (meth)acrylates and/or alkoxy (meth)acrylates may be used alone or in combination of two or more.

The repeating unit of the alkyl (meth)acrylate and/or alkoxy (meth)acrylate component unit (C) is mainly as follows.

Old H2-old-Coo-R (In the formula, R1 is the same as above, and R is an alkyl group or an alkoxyalkyl group.) The content of component (C) is 50 to 98% by weight, preferably 65 to 96% by weight. If it is less than 50% by weight, it is difficult to obtain a copolymer that has good compatibility with the thermosetting resin (prepolymer) and provides good adhesive strength,
On the other hand, if it exceeds 98% by weight, the amounts of components (A>component and (B)) containing other specific functional groups introduced will decrease, making it impossible to obtain a copolymer that provides good adhesive properties.

The copolymer of the present invention may optionally include the above (A) to (C).
) component and other monomer component units copolymerizable with the component, such as other vinyl compound component units, conjugated diene component units, polyhydric (
It is also possible to copolymerize 30% by weight or less of meth)acrylate component units.

Examples of the vinyl compound as the monomer (D) component constituting the copolymer of the present invention include α,β-unsaturated nitriles such as acrylonitrile and methacrylonitrile. In particular, the copolymer of the present invention in which α,β-unsaturated nitrile is copolymerized as component (D) is preferable because it has improved compatibility with the thermosetting resin prepolymer. The repeating unit of the α,β-unsaturated nitrile component unit (D) is mainly as follows.

(However, R1 is the same as above and represents a hydrogen atom or a methyl group.) In addition, the conjugated diene of the monomer (D) component is 1.3
Examples include -butadiene, isoprene, chloroprene, 1,3-pentadiene, hexadiene, etc., but butadiene and/or isoprene is preferred because of ease of copolymerization with other monomers.

The repeating units of the conjugated diene component unit (D) are mainly as follows.

I CH.

(However, R4 represents a hydrogen atom, a methyl group, or a chlorine atom.) Furthermore, as the polyvalent (meth)acrylate of the monomer (D) component, ethylene glycol di(meth)acrylate, propylene glycol (meth)acrylate , diethylene glycol di(meth)acrylate, and the like.

Taking ethylene glycol di(meth)acrylate as an example, the repeating unit of the polyvalent (meth)acrylate component unit (D) is mainly as follows.

(However, R1 is the same as above.) These vinyl compounds, conjugated dienes, and polyvalent (meth)acrylates can be used alone or in combination of two or more.

The content of component (D) to be used and copolymerized as necessary is:
30% by weight or less, preferably 25% by weight or less, and 3
If the amount exceeds 0% by weight, the elastic modulus of the resulting copolymer will decrease if component (D) is α, β-unsaturated nitrile or polyvalent (meth)acrylate, and it may not be added to the thermosetting resin prepolymer. When this happens, the flexibility imparting effect is poor,
When component (D) is a conjugated diene, heat resistance becomes poor, which is not preferable.

Next, the molecular weight of the copolymer of the present invention is preferably liquid from the viewpoint of dispersibility, compatibility and workability with the thermosetting resin prepolymer, and gel permeation chromatography of the copolymer The weight average molecular weight in terms of polystyrene by (G P C) is 1.000 to 30.0
00, preferably 3,000 to 10,000.

The copolymer of the present invention has a weight average molecular weight of 1.000.
If it is less than 3, sufficient flexibility cannot be imparted;
If it exceeds 0,000, it becomes difficult to handle it as a liquid, and therefore the dispersibility and compatibility with the thermosetting resin prepolymer may deteriorate.

The structure of the novel acrylic copolymer of the present invention shows α, β-
Caused by unsaturated compounds [(meth)acrylic acid derivatives that are components (A), (B), and (C), or in the case of polyvalent (meth)acrylate as component (D), the acrylic ester derivative] It can be confirmed by the absorption of the carbonyl group at 2250c+n-', the absorption of the nitrile group due to (meth)acrylonitrile at 2250c+n-', the absorption of the hydroxyl group at 3350cm-' due to the methylol group, etc., and the composition ratio of these is The (meth)acrylonitrile content was determined from the nitrogen content by elemental analysis, the content of component (A) was determined from the carboxy equivalent analysis by neutralization titration, and the (meth)acrylonitrile content was determined from the quantification by the infrared absorption spectrum calibration curve method.
B) The content of the ingredients can be known.

Such an acrylic random copolymer includes, for example, (A) 1 to 30% by weight of a carpoquinyl group-containing α,β-unsaturated compound represented by general formula (1), and (B) -i represented by formula (II). Methylol group-containing α, β-unsaturated compounds and/or epoxy group-containing α, β compounds represented by general formula (III)
- 1 to 20% by weight of an unsaturated compound; (C) 50 to 98% by weight of an alkyl (meth)acrylate and/or alkoxy (meth)acrylate having 4 to 16 carbon atoms copolymerizable with the above (A) and (B); , and (D) the above (A
), other monomers copolymerizable with (B) and (C) 0-
A 30% by weight mixture can be easily prepared as a random copolymer by emulsion radical polymerization or suspension radical polymerization in an aqueous medium or by solution radical polymerization in an organic solvent.

When producing a copolymer by emulsion radical polymerization,
- Methods known in the art, for example, using conventional radical initiators such as peroxide catalysts or redox catalysts as polymerization initiators, and anionic, cationic, nonionic and amphoteric surfactants as emulsifiers. Emulsion polymerization is carried out at a temperature of 0 to 50 °C in the presence of a molecular ff1311 moderating agent such as mercaptans or halogenated hydrocarbon compounds using either or a mixed system, and after reaching a predetermined polymerization conversion rate. The polymerization reaction is stopped by adding a reaction terminator such as Anti-aging agents such as di-t-butyl cresol are added, and aluminum sulfate water? A random copolymer can be obtained by coagulating latefux by mixing it with an aqueous solution of a metal salt such as liquid 8 or an aqueous solution of calcium chloride, and then drying it.

In this emulsion polymerization reaction, when a nonionic surfactant/active agent is used as an emulsifier, the copolymer latex obtained after carrying out the emulsion polymerization at a temperature below the cloud point of the nonionic surfactant is By heating to a temperature above its clouding point, it can be solidified without using a questioner (see Japanese Patent Application No. 170390/1982). In addition, during emulsion polymerization, after performing emulsion polymerization using at least an ionic surfactant as an emulsifier, the obtained copolymer latex is then heated in the presence of a nonionic surfactant and a metal-free electrolyte. (See Japanese Patent Application No. 60-215969)
. When the acrylic random copolymer of the present invention obtained by emulsion polymerization and iJJ hardening of the resulting latex is blended into a thermosetting resin prepolymer, electrical Excellent effects can be obtained on property modification.

In addition, when producing a copolymer by suspension radical polymerization, saponified polyvinyl alcohol is added as a dispersant, and polymerization is carried out using an oil-soluble radical initiator such as azobisisobutyronitrile or benzoyl peroxide. After the polymerization is completed, a polymer can be obtained by removing water.

Furthermore, when producing a copolymer by solution radical polymerization, generally known methods can be employed.

In this case, it is preferable to introduce a sulfur-carbon bond or a sulfur-hydrogen bond at the end of the molecular chain by using a mercaptan such as t-dodecyl mercaptan as a chain transfer agent. When blended with a thermosetting resin prepolymer, it can have a particularly remarkable effect on improving flexibility.

The polymerization method can be either continuous or batchwise.

The novel acrylic random copolymer of the present invention can be used as a flexibleizer by using thermosetting resin prepolymers such as melamine resins, urea resins or initial condensates of phenolic resins, or epoxy resin prepolymers (epoxy resin prepolymers and/or or modified epoxy resin prepolymer), especially a phenol resin initial condensate and/or an epoxy resin prepolymer, and used as a thermosetting resin composition as a paint, adhesive, coating agent, molding material, etc.

At this time, the copolymer of the present invention is blended with a thermosetting resin prepolymer or a curing agent for a thermosetting resin prepolymer and pre-reacted before the final preparation of the thermosetting resin composition. It is also possible to create an adduct of the two.

The copolymer of the present invention is used as a flexibleizer, and the thermosetting resin prepolymer used in combination with the copolymer is appropriately selected depending on the use of the obtained thermosetting resin composition, and various types are used. be able to. For example, the phenolic resin may include phenol, cresol,
List the condensates of formaldehyde and phenolic compounds such as xylenol, alkylphenols having an alkyl group having 2 to 12 carbon atoms, cyclohexylphenol, phenyl/L/phenol, halogen-substituted phenols, bishydroxyphenylphenol, and bisphenol A2 resorcinol. When the phenol resin is blended into the copolymer of the present invention, it is desirable that the phenol resin is an initial condensate having a degree of condensation of 1 to 10, preferably 1 to 5, based on the benzene nucleus.

Examples of epoxy resin prepolymers include condensation products of epichlorohydrin and polyhydric alcohols or polyhydric phenols, cyclohexane oxide epoxy resins, cyclopenkune oxide epoxy resins, and polymers or copolymers of polyolefins. Examples include epoxy resins obtained by copolymerizing glycidyl methacrylate and vinylated polymers, and epoxy resin prepolymers obtained from glycerides of highly unsaturated fatty acids. Further, these thermosetting resin prepolymers may be used in combination with other thermoplastic resins or thermosetting resins.

As a curing agent for a thermosetting resin prepolymer, such as an epoxy resin prepolymer, used in combination with the copolymer of the present invention as a flexibilizer, the curing type of the epoxy resin composition, such as a room temperature curing type (two-component type)
Alternatively, it is selected depending on the type of heat-curing type (-molding, two-component type), etc., and various types can be used.

Such curing agents include, for example, methylnadic anhydride,
dodecenyl succinic anhydride, tetrahydrophthalic anhydride,
Acid anhydrides such as hexahydrophthalic anhydride, methylcondomethylenetetrahydrophthalic anhydride, chlorendic anhydride, ethylene glycol trimellitic anhydride, methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, imidazole, 2-methyl Imidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-undecylimidazole, 2-heptadecyl imidazole, 1-benzyl-2-methylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl- 2-phenylimidazole, l
-cyanoethyl-2-ethyl-4-methylimidazole, ■-cyanoethyl-2-undecylimidazole, 1
-cyanoethyl-2-methylimidazole trimellitate, 1-cyanoethyl-2-phenylimidazole trimellitate, 2,4-diamino-6-(2'-methylimidazolyl-(1'))-ethyl-S-triazine,
2.4-diamino-6-(2'-undecylimidazolyl-(1'))-ethyl/1z-3-triazine, 2,4
-diamino-6-(2'-ethylimidazolyl-(1')
) -xf-S-triazine, 1-cyanoethyl-2-ethyl-4-methylimidazole trimellitate, ■-cyanoethyl-2-undecylimidazole trimellitate, 1-dodecyl-2-methinoυ-henzimidazolium chloride , l,3-dibenzyl-2
- imidazole derivatives such as methylimidazolium chloride, dicyandiamide or its derivatives, organic acid dihydrazides such as cehatate dihydrazide, 3-(p-
chlorophenyl)-1,1-dimethylurea, 3-(3
,4-dichlorophenyl)-1,1,-dimethylurea and other urea derivatives, polyamidoamines, modified polyamines,
Examples include boron fluoride-monoethylamine complex.

Additionally, polymers such as polyamide and novolak resin can be used.

The novel acrylic random copolymer of the present invention is used as a thermosetting resin composition as a flexibleizer in combination with a thermosetting resin prepolymer and its curing agent. The amount is 1 to 200 parts by weight, preferably 10 to 100 parts by weight, per 100 parts by weight of the curable resin prepolymer.

The amount of the curing agent to be blended is appropriately selected depending on the thermosetting resin (prepolymer) and curing agent.

The acrylic random copolymer of the present invention can be used as a flexibleizer together with a thermosetting resin prepolymer (and its curing agent), as well as ordinary fillers, diluents, resin solvents, rust preventives, dyes, etc. It can be used in combination with various additives such as pigments and anti-aging agents.

In addition, the copolymer of the present invention and the thermosetting resin prepolymer can be mixed as they are using a mixer such as a kneader, roll, or Banbury mixer, or they can be mixed separately using a mixer. Yong Qi Suni? capacity)? 8
It can also be combined as a liquid.

Furthermore, the copolymer or copolymer solution of the present invention can be allowed to coexist during the production of a thermosetting resin prepolymer to prepare a thermosetting resin composition containing the copolymer.

[Effect]

The acrylic random copolymer of the present invention is a copolymer in which carboxyl groups are randomly distributed as side chains in the molecular chain.

The reason why this copolymer is particularly effective as a flexibilizer is not necessarily clear, but the reason is that the interface between the micro-separated thermoplastic resin prepolymer phase and the copolymer base is bonded by randomly distributed carboxyl groups. This is thought to allow external energy to be efficiently transmitted to the elastic copolymer phase and dissipate the external energy effectively.Furthermore, the acrylic random copolymer of the present invention is Since the distribution of the groups is uniform, no gelation occurs when pre-reacted with a thermosetting resin prepolymer.

Furthermore, since the acrylic random copolymer of the present invention has a methylol group or an epoxy group in the copolymer chain, it not only has self-curing properties and enhances the interaction with the resin, but also increases the elastomer content at high temperatures. The problem of migration does not occur.

〔Example〕

EXAMPLES Hereinafter, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited to these Examples. In addition, "parts" and "%" in the examples are, in principle, based on weight.

Examples 1 to 4 and Comparative Examples 1 to 7 Production of copolymers a%k Using the polymerization respi shown below, solution polymerization was carried out under the following conditions in a glass autoclave with an internal volume of 41 at 70°C under a nitrogen atmosphere. Manufactured by doing.

Polymerization Respi (part) monomer; 100 toluene;
100 Azobisisobutyronitrile l Tertiary dodecyl mercaptan;
4- The polymerization conversion rate reached 97% in a polymerization reaction time of 7 hours. Next, unreacted monomers and toluene as a solvent are removed by heating under reduced pressure,
The desired copolymer a was obtained. The infrared absorption spectrum of copolymer a is shown in FIG. 1, and the results are shown in Table 1. Thereafter, copolymers bk shown in Table 1 were produced in the same manner. The weight average molecular weight of the produced copolymer is the polystyrene equivalent value determined by gel permeation chromatography, and its composition was determined by elemental analysis and infrared absorption spectrum, and the results are shown in Table 1. .

Production of epoxy resin composition The copolymers ad (Examples 1 to 4) and e to k (Comparative Examples 1 to 7) were each used as a flexibleizer,
An epoxy resin composition was prepared using the following blending ratio.

For formulation of epoxy resin composition (Part) Epoxy resin prepolymer (manufactured by Mitsui Petrochemical Industries, Ltd., EPO
MIK R140); 10 Copolymer; 15 Methyl ethyl ketone; 75 Curing agent = 2-ethyl-4-methylimidazole; O In Examples 1 to 4 and Comparative Examples 1 to 7, tetrabutylammonium iodide was used as a catalyst in advance. The flexibilizer and the epoxy resin prepolymer were mixed, and a preliminary reaction was carried out at 40° C. for 7 days, at which point gelation was checked.

Characteristic test regarding adhesive properties of epoxy resin composition Using the epoxy resin composition obtained as described above as an adhesive, the following characteristic test regarding adhesive properties was conducted.

That is, the above adhesive was applied to a thickness of 50 μm between a 30 μm thick copper foil and a 100 μm thick polyester film, and after drying at 150° C. for 30 minutes, JIS C64 was applied.
The peeling force was measured according to 81. The average peeling force of 5 tests using copolymer a was 1.2 kg/c
It was +a.

The peeling force values shown in Table 1 are the lowest values of five tests in accordance with the JIS display method.

Moreover, flexibility was evaluated by the following method.

That is, the bonded portion between the polyester film and the copper foil was repeatedly bent at 180° C. 20 times, and the presence or absence of cracks in the adhesive layer was visually observed. The flexibility shown in Table 1 is based on the above evaluation, with ○ indicating that no cracks were generated, and × indicating that cracks were present.

When an adhesion test was conducted using this in the same manner as in Example 1, the peeling force was 0.80 kg/cm.

Example 6 A composition was prepared in the same manner as in Example 5 except that the copolymer was used, and an adhesion test was conducted, and the peeling force was 0. 7
It was 4 kg/cm.

Comparative Example 8 A composition was prepared in the same manner as in Example 5 except that copolymer f was used, and an adhesion test was performed. The peel force was 0.
It was 36 kg/cm.

Comparative Examples 9-10 When compositions were prepared in the same manner as in Example 5 except for using copolymer e or g, the compositions were not uniform at the stage of preparation, making it impossible to evaluate adhesion.

As mentioned above, from Examples 5 to 6 and Comparative Examples 8 to 10, it can be seen that the copolymer of the present invention provides a composition that has good compatibility with the phenol resin initial condensate and has excellent adhesive strength.

〔Effect of the invention〕

When the novel acrylic copolymer of the present invention is blended into a thermosetting resin prepolymer as a flexibilizer, it exhibits good flexibility while retaining the excellent mechanical strength originally possessed by thermosetting resins. In addition to mechanical strength, adhesives and paints that require high peel strength and flexibility, coatings that require crack resistance, molded products that require impact resistance, etc. It is possible to provide a thermosetting resin composition suitable for.

Furthermore, the thermosetting resin composition containing the copolymer of the present invention as a flexibleizer can be blended with thermosetting resins other than those mentioned above, as well as polyamides, novolac resins, polyesters, etc., to cure these resins. physical,
It is also useful for modifying chemical properties.

In particular, the thermosetting resin composition of the present invention has excellent adhesion between resins such as polyester and metals such as copper, and has good storage stability as an adhesive. When a phenol resin is used, it has extremely good compatibility with the copolymer of the present invention, so it can be prepared as a uniform adhesive solution. In addition, by blending the copolymer of the present invention as a flexibilizer, the adhesive has excellent flexibility after curing, so it can be used as an adhesive for metals and resins, such as adhesives for flexible printed circuit boards. It is also used as a surface coating agent for metals.

[Brief explanation of drawings]

FIG. 1 is an infrared absorption spectrum of the copolymer of the present invention.

Claims (7)

[Claims] (1) (A) Carboxyl group-containing α,β-unsaturated compound component unit represented by general formula (I) 1 to 30% by weight, ▲There are mathematical formulas, chemical formulas, tables, etc.▼...(I) ( In the formula, R^1 is a hydrogen atom or a methyl group, R^2 is an alkylene group having 2 to 6 carbon atoms, and R^3 is a phenylene group, a cyclohexylene group, an alkylene group having 2 to 6 carbon atoms, or an alkylene group having 2 to 6 carbon atoms. 6 divalent unsaturated hydrocarbon group.), (
B) Methylol group-containing α,β- represented by general formula (II)
Unsaturated compound component units and/or epoxy group-containing α,β-unsaturated compound component units represented by general formula (III) 1 to 20% by weight, ▲Mathematical formulas, chemical formulas, tables, etc.▼...(II ) (In the formula, R^1 is the same as above, and X represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.) ▲There are numerical formulas, chemical formulas, tables, etc.▼...(III) (In the formula, R^1 is the same as above, Y represents an alkylene group having 1 to 6 carbon atoms.) (C) Alkyl (meth)acrylate having 4 to 16 carbon atoms that can be copolymerized with the components (A) and (B) above. 50 to 98% by weight of component units and/or alkoxy (meth)acrylate component units, and (D) the above (A), (B)
and 0 other monomer component units copolymerizable with component (C)
30% by weight, and has a weight average molecular weight in terms of polystyrene of 1,000 to 30,000. (2) The acrylic random copolymer according to claim 1, wherein component (A) is a phthalic acid mono(methacrylooxyethyl) ester component unit. (3) component (D) is an acrylonitrile component unit,
Claim 1 in which the content is 5 to 30% by weight
The acrylic random copolymer described in . (4) (A) (A) Carboxyl group-containing α,β-unsaturated compound component unit represented by general formula (I) 1 to 30% by weight, ▲Mathematical formulas, chemical formulas, tables, etc. are available▼・・・( I) (In the formula, R^1 is a hydrogen atom or a methyl group, R^2 is an alkylene group having 2 to 6 carbon atoms, and R^3 is a phenylene group, a cyclohexylene group, an alkylene group having 2 to 6 carbon atoms, or a carbon Indicates a divalent unsaturated hydrocarbon group having numbers 2 to 6.), (
B) Methylol group-containing α,β- represented by general formula (II)
Unsaturated compound component units and/or epoxy group-containing α,β-unsaturated compound component units represented by general formula (III) 1 to 20% by weight, ▲Mathematical formulas, chemical formulas, tables, etc.▼...(II ) (In the formula, R^1 is the same as above, and X represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.) ▲There are numerical formulas, chemical formulas, tables, etc.▼...(III) (In the formula, R^1 is the same as above, Y represents an alkylene group having 1 to 6 carbon atoms.) (C) Alkyl (meth)acrylate having 4 to 16 carbon atoms that can be copolymerized with the components (A) and (B) above. 50 to 98% by weight of component units and/or alkoxy (meth)acrylate component units, and (D) the above (A), (B)
and 0 other monomer component units copolymerizable with component (C)
-30% by weight, and has a weight average molecular weight of 1,000 to 30,000 in terms of polystyrene, is blended into (b) a thermosetting resin prepolymer. A thermosetting resin composition. (5) For 100 parts by weight of thermosetting resin prepolymer,
The thermosetting resin composition according to claim 4, which contains 1 to 200 parts by weight of an acrylic random copolymer. (6) The thermosetting resin composition according to claim 4 or 5, wherein the thermosetting resin prepolymer is an epoxy resin prepolymer and/or a modified epoxy resin prepolymer. (7) The thermosetting resin composition according to claim 4 or 5, wherein the thermosetting resin prepolymer is a phenolic resin initial condensate.