JPS5912920A - Thermosetting epoxy resin composition - Google Patents

Abstract

PURPOSE:The titled composition, prepared by incorporating an epoxy resin with a phenolic novolak resin and a copolymer containing isopropenylphenol as one component as a hardener, and capable of giving hardened articles having improved heat and water resistance and felxibility and adhesive property. CONSTITUTION:A thermosetting epoxy resin composition prepared by incorporating an epoxy resin, e.g. bisphenol A type, with a phenolic novolak resin, e.g. a reaction product of an excess amount of phenol with a formaldehyde in the presence of an acidic catalyst, and a copolymer containing isopropenylphenol having a moderately controlled content of phenolic OH groups in one molecule as one component in the presence of a radical polymerization initiator, e.g. azoisobutyronitrile, by the solution polymerization method, etc. as a hardener. USE:Molding, laminating, coating, adhesive materials, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel thermosetting epoxy resin composition comprising an epoxy resin mixed with a copolymer containing phenol novolac and impropenylphenol as one component.

More specifically, the present invention relates to a thermosetting epoxy resin composition that provides a cured product with excellent heat resistance, flexibility, adhesiveness, and water resistance.

Conventionally, thermosetting resin compositions made by blending phenol novolak resins with epoxy resins have excellent curability and provide cured products with excellent heat resistance, so they have been used as molding materials, laminated materials, paints, adhesive additives, etc. It is widely used.

However, in recent industrial fields such as electronic equipment,
With miniaturization and higher density, high reliability is required, and there is a tendency for demands for flexibility as well as heat resistance to increase.

However, compositions made by blending phenol novolac resins with epoxy resins have poor flexibility and can cause cracks in molded products that encapsulate electronic components such as semiconductors, and cracks during cooling and heating cycles in laminates housing electronic devices. This caused problems such as outbreaks.

Furthermore, the cured product of the above composition has poor adhesion and water resistance, so when it is made into a molded product, there are problems such as a decrease in strength due to a decrease in the adhesive force between the resin and the filler, and a decrease in electrical properties after water absorption treatment. there were. Furthermore, laminated materials such as
When used on copper-clad laminates and laminates based on glass cloth, the adhesive strength is not sufficient, resulting in interlayer peeling between the glass cloths and the need for a separate adhesive between the copper foil and the laminate material. There was a drawback.

As a result of intensive studies to solve the above-mentioned drawbacks, the present inventors have developed a thermosetting epoxy made by blending an epoxy resin with a copolymer containing phenol novolak resin and impropenylphenol as a curing agent. The inventors have discovered that a resin composition can provide a cured product with excellent heat resistance, flexibility, adhesiveness, and water resistance, leading to the present invention.

The present invention uses phenolic O as a curing agent for epoxy resin.
Polymers with H, i.e., phenol novolak (grease-resistant, - polymers with an appropriately controlled content of phenolic OH in the molecule, i.e., copolymers containing isopropenylphenol as one component) (hereinafter abbreviated as p copolymer), in addition to the heat resistance of cured products conventionally obtained with compositions consisting of epoxy resin and phenol novolac resin, flexibility is further improved, and The present invention provides a completely new thermosetting epoxy resin composition with improved adhesiveness and water resistance.

The p-copolymer used in the present invention is a copolymer of impropenylphenol and one or more other polymerizable monomers. Other polymerizable monomers include the following. For example, styrene, chlorstyrene,
Styrenes such as bromustyrene, α-methylstyrene, vinyltoluene, vinylxylene, methyl acrylate,
Acrylic esters such as ethyl acrylate, n-butyl acrylate, and 2-ethylhexyl acrylate, methacrylic esters such as methyl methacrylate, ethyl methacrylate, and 9-butyl methacrylate, acrylonitrile, and methacrylate. There are polymerizable monomers that can be coarranged, such as nitrile, fumaronitrile, acrylic acid, methacrylic acid, maleic anhydride, acrylamide, methacrylamide, isoprene, butadiene, and dicyclopentadiene.

Moreover, isopropenylphenol in the p copolymer may be any of ortho form, meta form, para form, or a mixture thereof.

The content of isopropenylphenol in the p copolymer used in the composition of the present invention is 5 to 90% by weight in the p copolymer,
Preferably jO to 80% by weight. If the content of impropenylphenol is less than 5% by weight, it will not be possible to obtain a composition that provides a cured product with excellent heat resistance and water resistance, which is the objective of the present invention, and if it exceeds 90% by weight, flexibility and adhesion will occur. A cured product with excellent properties cannot be obtained.

When producing a p-copolymer, it is possible to perform polymerization by radical polymerization, ionic polymerization, charge transfer polymerization, etc., but radical polymerization using a radical polymerization initiator is preferable because it is easy to control the reaction. Excellent in every respect. Examples of the radical polymerization initiator include azo initiators such as azopisisobutylonitrinoheazobis-2,4-dimethylvaleronitrile, azobiscyclohexanecarbonitrile, azobis-2-amidinopropane・ll0JJ, M, and benzoyl peroxide. , peroxide-based initiators such as lauroyl peroxide, acetyl peroxide, cumene hydroperoxide, differential-butyl hydroperoxide, and seed-butyl hydroperoxide, benzoyl peroxide-N, N-dimethylaniline, beroxonisulfate-bisulfite Examples include redox initiators such as sodium. The amount of initiator used is 0.001% relative to the total amount of various monomers that are the raw materials for the p copolymer.
~10% by weight is preferred. A method known as a polymerization method,
That is, the p copolymer can be easily produced using solution polymerization, suspension polymerization, emulsion polymerization, bulk polymerization, or the like.

The p copolymer used has a molecular weight of 500 to 50,000, preferably 1.000 to 30,000. 50
If it is less than 0 or exceeds 50,000, it will not be possible to obtain a composition that provides a cured product with excellent heat resistance, flexibility, adhesiveness, and water resistance, which is the objective of the present invention.

Next, the phenol novolak resin used in the present invention is generally prepared by using an acid as a catalyst to combine phenols such as phenol, cresol, xylenol, and resorcinol with formaldehydes such as an aqueous formaldehyde solution, paraformaldehyde, and trioxane in an excess amount of moles of the phenol. It is obtained by reacting in the state of Further, for the purpose of the present invention, it is desirable for the amount of free phenol in the phenol novolac to be 1 part or less.

Moreover, any epoxy resin used in the present invention can be used as long as it has at least two or more types of -H epoxy groups in one molecule. For example, various epoxies such as bisphenol A type, halogenated bisphenol type, resorcin type, bisphenol F type, tetrahydroxyphenylmethane type, novolak type, polyglygol type, glycerin triether type, polyolefin type, epoxidized soybean oil, and alicyclic type. Examples include resin.

The constituent proportions of the epoxy resin, phenol novolak resin, and p-copolymerization in the thermosetting epoxy resin composition of the present invention can be blended in various proportions as necessary. First, the composition ratio of the phenol novolac resin and the p copolymer is 0.05 to 20, preferably 0.01 to 0.01 by weight.
It is desirable to use it in the range of ~10. When the weight ratio of the phenol novolac resin to the p copolymer is less than 0.005 and more than 20, the heat resistance, which is a feature of the present invention, is excellent;
Moreover, it is difficult to obtain a cured product with good flexibility.

Furthermore, the composition ratio of the phenol novolak resin and p copolymer to the epoxy resin is determined by calculating the sum of the number of hydroxyl groups in the phenol novolac and the number of hydroxyl groups in the p copolymer to the number of epoxy groups in the epoxy resin (7). It is desirable to use it within the range of 02 to 50, preferably 05 to 2.0 (number of OH groups/number of epoxy groups). If the OH group/epoxy group ratio is less than 0.2 or more than 50, a cured product with excellent heat resistance, flexibility, and adhesiveness cannot be obtained.

Furthermore, the following curing aids can be used in combination with the thermosetting epoxy resin composition according to the present invention, if necessary. That is, as curing aids, tertiary amines such as N,N-dimethylbenzylamine, triethylamine, and triethanolamine, heterocyclic compounds such as pyridine, piperidine, and imidazole, BF3/pyridine, and BF3/piperidine are used. , complex salts of Lewis acids and amines such as BF3.monoethylamine, amine carboxylates such as N,N-dimethylbenzylamine acetate, piperidine-acetate, etc. may be used in combination. In this case, the amount used is preferably 01 to 10% by weight relative to the composition.

The thermosetting epoxy 1 resin composition according to the present invention can be used as follows. That is, the phenol novolac resin and the p copolymer may be mixed with the epoxy resin and then pulverized, or the mixture may be heated at 80 to 170° C. for several minutes to melt and then pulverized. Furthermore, common solvents for epoxy resins, phenol novolac resins, and p copolymers, such as alcohols such as methanol, ethanol, propatool, benzyl alcohol, and diacetone alcohol, acetone, methyl ethyl ketone,
Ketones such as methyl isobutyl ketone and cyclohexanone, ethers such as dioxane, tetrahydrofuran, methyl cellosolve, and ethyl cellosolve, esters such as ethyl flI acid and butyl acetate, dimethylformamide, dimethylacetamide, N-methyl-2-pyrrolidone, etc. It can also be used in a phenol state using one or more solvents such as nitrogen-containing solvents, benzene, toluene, xylene, etc., hydrocarbons, dimethyl sulfoxide, etc.

The thermosetting epoxy resin composition of the present invention has excellent heat resistance and flexibility, and can yield a well-balanced cured product with excellent adhesiveness and water resistance, so it can be used as a molding material, It can be used in a wide range of applications such as laminated materials, paints, and adhesives.

Next, various application examples of the composition according to the present invention will be described.

When used as a molding material, a mixed powder product or a partially cured powder product can be molded into a molded product at a temperature of 80 to 250 ° C by compression molding, transfer molding, or injection molding. Silica, calcium carbonate, talc, clay, wood flour, asbestos, glass powder, glass fiber, etc. may be added as fillers.

When making a laminated material, paper or glass fiber is impregnated with pheno in which the composition of the present invention is dissolved in a solvent, the solvent is removed to form a prepreg, and several to dozens of sheets are stacked to form a 100-layer prepreg.
Temperatures of ~200°C and pressures of 20 to 100 kV/cd make it possible to obtain laminates. The laminate may be further post-cured for several hours at 160-250°C, if desired.

For use in paints, apply the phenol etc. of the composition of the present invention to a support and heat-dry it at 100 to 200°C, or mix the pulverized or milk-hardened powder to dielectric. Coat and spread on the copper plate using a coating machine etc.,
A coating film with uniform thickness can be obtained by baking at 200°C.

In addition, for use in adhesives, a reactive diluent such as phenyl glycidyl ether, filler such as silica, asbestos, etc. may be added to the composition of the present invention as required, and after coating on the adherend, the adherend is applied for 80 minutes. It can be cured and bonded by heating to ~2000C.

Hereinafter, the composition of the present invention and its characteristics will be explained in more detail with reference to Examples and Test Examples, but the present invention is not limited to the following Examples and Test Examples.

In the following, unless otherwise specified, parts and Tohoku rates are based on weight.

Production Example 1 In a flask equipped with a stirrer and a condenser, 10 parts of lysopropenylphenol (hereinafter referred to as P, IPFi and In), 90 parts of n-butyl acrylate, methyl ethyl ketone (
263 parts of MEK (hereinafter abbreviated as MEK) and 4.8 parts of azobisisobutyronitrile (hereinafter abbreviated as AIBN) were charged all at once, and the mixture was heated and refluxed with stirring to polymerize for 4 hours. Further, 2.4 parts of AIBN was added, and the mixture was heated and refluxed for 4 hours to obtain a copolymer solution with a solid content concentration of 280%. This solution was dried under reduced pressure at 170°C for 2 hours to obtain p copolymer (1).
Obtained 91 copies.

The weight average molecular weight of this copolymer determined by gel permeation chromatography (hereinafter referred to as GPC) was 110'O.
, O, and the OH value by the acetylation method is 44 KOH.
/,! It was il.

Production Example 2 PIPE30 in a flask equipped with a stirrer and condenser
1 part, 70 parts of methyl methacrylate, 00 parts of MEK i, and 4.8 parts of AIBN were charged all at once and heated while stirring.
The mixture was refluxed and polymerized for 4 hours. Furthermore, 24 parts of AlBN was added, heated for 4 hours, and refluxed to obtain a solid content of 43.0.
% copolymer solution was obtained. This FEW was heated to 170°C for 2
The mixture was dried under reduced pressure for hours to obtain 84 parts of copolymer (2). G.P.O.
The polymerization average molecular weight of this copolymer according to the method is 62-00, and the OH value according to the acetylation method is 137 WKOH/9.
Met.

Production example 6 PIPE5 in a flask with a stirrer and a condenser
0 parts, 50 parts of styrene, 70 parts of MEK and AIBN
Add 4.8 parts at once, heat and reflux while stirring.
Polymerized for hours. Furthermore, AIBN 2. After adding part a, heating and refluxing were continued for 4 hours to obtain a copolymer solution with a solid content concentration of 495%. This solution was dried under reduced pressure at 17,000 for 2 hours to obtain 84.5 parts of copolymer (3). The weight average molecular weight of this copolymer by OPO is 5300, and the OH value by acetylation method is 195~+<on/fl
Met.

Production example 4 PIPE60 in a flask equipped with a stirrer and condenser
parts, 40 parts of ethyl acrylate (hereinafter abbreviated as gA'), M
233 parts of BK and 4.8 parts of AIBN were charged all at once, heated under stirring to reflux, and polymerized for 4 hours. Furthermore, 2.4 parts of AIBN was added and heated for 4 hours.
The mixture was refluxed to obtain a copolymer solution with a solid content of 284%.

This solution was dried under reduced pressure at 170°C for 2 hours to obtain 92 parts of copolymer (4). The weight average molecular weight of this copolymer according to GPO is 8600, and the OH
The value was 237 qKOH/g.

Production Example 5 65 parts of PIPE, 25 parts of EA, and acrylonitrile (hereinafter abbreviated as AN) in a flask equipped with a stirrer and a condenser.
Prepare 10 parts and 4.8 parts of AIBN at once,
The mixture was heated and refluxed while stirring to polymerize for 4 hours. Furthermore, AI
2.4 parts of BN was added, and the mixture was heated and refluxed for 4 hours to obtain a copolymer solution with a solid content concentration of 290 cm. Add this solution to 17
It was dried under reduced pressure at 0°0 for 2 hours to obtain 93 parts of copolymer (5). The weight average molecular weight of this copolymer according to GPO is 89
00, and the OH value by the acetylation method is 27 D I
IIPKOH/, 9.

Production Example 6 In a flask equipped with a stirrer and a condenser, add pIprg7.
5 parts, AN 25 parts, MFiK 233 parts, and AI
48 parts of BN was charged in one batch, heated under stirring to reflux, and polymerized for 4 hours. Furthermore, 2.4 parts of AIBN was added, and the mixture was heated and refluxed for 4 hours to obtain a copolymer FE liquid with a solid content concentration of 28.0. This solution was heated at 170°C for 2
The mixture was dried under reduced pressure for hours to obtain 92 parts of copolymer (6).

The average molecular weight of this copolymer by GPO was 950, and the OH value by acetylation was 606 to KOH.

Example 1 Orthocresol novolak type epoxy resin (YDON-22OL manufactured by Tobu Kasei Co., Ltd. Epoxy equivalent weight 225, hereinafter referred to as YDO
214 parts of phenol novolac resin (abbreviated as N-22OL) (manufactured by Mitsui Toatsu Chemical Co., Ltd., ≠2000, OH1 piece 536
vxo++/g, hereinafter abbreviated as Novolak 42000) 9
0 parts and 10 parts of the copolymer (1) obtained in Production Example 1 were added, and the mixture was ground into 100 meshes or less using a grinder to obtain a thermosetting epoxy resin composition.

Example 2 Bisphenol A type epoxy resin (Epicote 828 manufactured by Yuka Shell, epoxy equivalent 190, hereinafter referred to as Epicote 82)
8), 137 parts of novolac≠200070 parts, and 30 parts of copolymer (2) obtained in Production Example 2 were added to γSe)'/2
The solution was dissolved in 40 parts to obtain a uniform bath solution. This solution was dried under reduced pressure at room temperature to remove most of the acetone, and a thermosetting epoxy resin composition was obtained.

Example 3 Novolak in 124 parts of Epicote 828: #8200
050 parts and 50 parts of the copolymer (3) obtained in Production Example 3 were added, melt-kneaded with a heated roll at 90°C, cooled down, and then pulverized to obtain a thermosetting epoxy resin composition.

Example 4 Novolac type epoxy resin (Epicoat 1 manufactured by Yuka Shell Co., Ltd.
54, epoxy equivalent 17B) 86 parts, novolac-! #
-200010 parts and copolymer (4) obtained in Production Example 4
90 parts were dissolved in 190 parts of acetone to form a homogeneous solution.

This solution was dried under reduced pressure at room temperature to remove most of the acetone, and a thermosetting epoxy resin composition was obtained.

Example 5 Epicote 828110 parts, Novolac≠200020
and 80 parts of the copolymer (5) obtained in Production Example 5 were dissolved in 210 parts of acetone to form a uniform solution. This solution was dried under reduced pressure at room temperature to remove most of the acetone, yielding a thermosetting epoxy resin composition.

Example 6 Ebiko) 828 1.50 parts, Novolac≠2000
60 parts of the copolymer (6) obtained in Production Example 6 were dissolved in 250 parts of acetone to form a uniform solution. This solution was dried under reduced pressure at room temperature to remove most of the acetone and obtain a thermosetting epoxy resin composition.

Comparative Example 1 Novolac≠200 in 214 parts of YDON 220L
0,100 parts were added, and the mixture was ground to 100 mcg or less using a grinder to obtain a thermosetting epoxy resin composition.

Comparative Example 2 181 parts of Epicote 828 and Novolak≠200
0 was dissolved in 200 parts of acetone to form a homogeneous solution. This solution was dried under reduced pressure at room temperature to remove most of the acetone, thereby obtaining a thermosetting epoxy resin composition.

The following tests were conducted on each thermosetting epoxy composition obtained in Examples 1 to 6 and Comparative Examples 1 to 2.

Test method A) Heating weight loss rate of molded body, Charpy impact test, metal insert crack test and water absorption rate.

■Preparation of molded bodies 100% of each composition obtained in Examples 1 to 5 and Comparative Examples 1 to 2
0.1 part of N,N-dimethylbenzylamine and 0.5 parts of BF3/piperidine as a hardening agent, 1 part of magnesium stearate and 1 part of carnauba wax as a mold release agent, and 200 parts of fused silica and carbon as a filler. 5 parts of black was added, melted and kneaded for 6 minutes using hot rolls at 110°C, cooled, and then crushed to obtain a molded powder.

This molded powder was compressed using a compression molding machine at a temperature of 160°C and a pressure of ao ha/cd to obtain a molded product. Bost cured at a temperature of 160°C for 10 hours, the resulting molded product was It was used for each test.

■Put the molded body produced with heating weight reduction rate A-■ into a hot air circulation dryer,
The weight loss rate after heating at a temperature of 250°C for a predetermined time was measured.

■Charpy impact test According to JISK6911.

(2) Crack resistance of a metal insert A molded body having a diameter of 60 am and a thickness of 7 mm in which a brass panel with a thickness of 5 pieces having a square shape of 35 mm on a side was inserted was prepared by the method A-(2). This molded body is 150°0
The sample was immersed in dry ice-methanol for 60 minutes, and then left in a hot air circulation dryer at 120'O for 30 minutes. This operation is considered as one cycle, and the size until crack generation is 5.
I checked the number of clusters.

(2) Water absorption rate The water absorption rate was measured in accordance with JIS K6911 under normal conditions and after being immersed in boiling water for 24 hours.

B) Hot bending strength, copper peeling strength of copper-clad laminates,
Water absorption rate.

■Preparation of copper-clad laminate 100g of each of the above compositions was mixed with 100g of methyl ethyl ketone.
g to obtain a uniform mW. This solution, i.e. glass cloth (104BZ-2 for Nitto Boseki WE18)
, thickness 0.1/1 fi), and the glass cloth impregnated with the cloth was taken out and air-dried for 10 minutes. This is 14
It was dried for 5 minutes in a dryer at 0'O to obtain a prepreg.

Nine sheets of this prepreg were stacked, the top and bottom surfaces were sandwiched between 65μ thick copper foils, and pressed at 160°0. 30 kg
Compression molding was performed for 20 minutes under loA conditions.

Next, the temperature was increased to 170° C. and the pressure was increased to 70 kq/cd, and heating and pressurization was further performed for 6 hours to obtain a double-sided copper-clad laminate having a thickness of 16 rum.

■Bending strength at heat The bending strength at 150°C was measured according to JIS 06481.

■Copper peeling strength According to J'(, 4 06481.

■Water absorption rate Measure the water absorption rate after treatment at 23°C for 24 hours according to JIS 06481.

C) DuPont impact test and tensile shear test of coatings.

■Dupont impact test 100 parts of each of the above compositions plus 0.1 part of N,N-dimethylbe/zylamine and 1 part of BF3/piperidine as a curing aid.
04 parts were added, melt-kneaded with a hot roll at 120°C, cooled, and ground to 80 mesh or less. Using this powder 1
Powder coating was performed on an annealed copper plate preheated to 60°C by a fluidized dipping method, followed by post-curing at 180°C for 2 hours to produce a coating film with a thickness of 300μ. Next, the maximum height at which no cracks would occur was determined by a DuPont impact test using a 1 part 8 inch JIA diameter and a 500I drop 7 (j).

■Powder coated to a thickness of 100μ in the same way as the tensile shear test■, and JI
According to S K6850, a tensile shear test piece was prepared under curing conditions of 180°0 and 2 hours, and the tensile shear force at room temperature and 150°0 was measured.

Test Example 1 Using each composition obtained in Examples 1 to 3 and Comparative Examples 1 to 2, each physical property was measured according to test method A) in order to examine the heat resistance, flexibility, and water resistance of the molded article. did. The results are shown in Table-1.

Test Example 2 Using each composition obtained in Examples 4 to 6 and Comparative Example 2, each physical property was measured according to test method B) in order to examine the heat resistance, adhesiveness, and water resistance of a copper-clad laminate.

The results are shown in Table-2.

Test Example 3 Using each composition obtained in Examples 5 to 6 and Comparative Example 2, each physical property was measured according to test method C) in order to examine the flexibility and adhesiveness of the coating film. The results are shown in Table-3.

Table-1 Table-2 Patent applicant: Mitsui Toatsu Chemical Co., Ltd.

Claims (1)

[Claims] 1) A thermosetting Hokuriku epoxy resin composition comprising an epoxy resin mixed with a phenol novolac resin as a cured pongee and a copolymer containing impropenylphenol as a component.