JPH1149854A - Thermosetting resin composition to be preparatorily set by active energy ray - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject resin composition excellent in heat resistance, electric insulation after a pressure cooker resistance treatment, chemical resistance, etc., and useful for a formation of coating film by including a multifunctional cyanic ester compound, alicyclic epoxy group-containing unsaturated compound, photopolymerization initiator, and thermosetting catalyst. SOLUTION: This resin composition is obtained by including 10 to 80 wt.%, pref. 20 to 70 wt.%, of a multifunctional cyanic ester compound or the cyanic ester prepolymer [e.g. 2,2-bis(4-cyanatophenyl)propane], 20 to 90 wt.%, pref. 25 to 80 wt.%, of alicyclic epoxy group-containing unsaturated compound (e.g. 3,4-epoxycyclohexyl methyl acrylate), 0.1 to 20 wt.%, pref. 0.5 to 15 wt.%, of photopolymerization initiator [e.g. 2-methyl-1-(4-methylthio-phenyl)-2- morpholinopropane-1-one], and 0.005 to 5 wt.%, pref. 0.01 to 3 wt.%, of thermosetting catalyst [e.g. zinc octylate].

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an active energy ray precurable thermosetting resin composition having excellent heat resistance, moisture absorption, electrical insulation after pressure cooker treatment, chemical resistance and the like, and relates to a printed wiring board and the like. And used for applications such as forming a permanent protective film.

[0002]

2. Description of the Related Art Conventionally, various types of active energy ray precurable thermosetting resin compositions have been developed and used. As these resins, resins containing unsaturated groups, such as (meth) acrylate resins and vinyl resins, are used. However, heat resistance, moisture absorption, electric insulation after pressure cooker treatment, chemical resistance, etc. are now a step away. There was a problem with reliability.

As a countermeasure, attempts have been made to increase heat resistance and the like by adding epoxy acrylate and epoxy resin to (meth) acrylate resin and vinyl resin, but this has not been sufficient.

[0004]

DISCLOSURE OF THE INVENTION The present invention relates to a heat-resistant, moisture-absorptive, and electrically insulating film after pressure cooker treatment of a permanent protective film using a conventional active energy ray-curable resin, which can be pre-cured with an active energy ray. It is intended to greatly improve the properties and chemical resistance.

[0005]

The present invention has been made as a result of intensive studies to solve the above-mentioned problems. As a result, a polyfunctional cyanate ester compound, an alicyclic epoxy group-containing unsaturated compound and a photopolymerization initiator have been developed. It has been found that by using a resin composition containing a thermosetting catalyst as an essential component, it is possible to obtain a permanent protective coating excellent in heat resistance, electric insulation after moisture absorption and pressure cooker treatment, chemical resistance, and the like. To complete the invention.

That is, the present invention provides (a) a polyfunctional cyanate compound or 10 to 80% by weight of the cyanate ester prepolymer, and (b) an alicyclic epoxy group-containing unsaturated compound of 20 to 90% by weight. %, (C) 0.1-20% by weight of a photopolymerization initiator and (d) 0.005-5% by weight of a thermosetting catalyst as an active energy ray precurable thermosetting resin composition. .

Hereinafter, the configuration of the present invention will be described. First, (a). The polyfunctional cyanate compound of the present invention is an aromatic organic compound having usually 2 to 5 cyanato groups (—O—C≡N) in a molecule, The cyanato group is directly bonded to the aromatic ring of the aromatic organic compound. Specific examples include 1,3- or 1,4-dicyanatobenzene, 1,3,5-tricyanatobenzene, 1,3-, 1,4-, 1,
6-, 1,8-, 2,6- or 2,7-dicyanatonaphthalene, 1,3,6-
Tricyanatonaphthalene, 4,4-dicyanatobiphenyl,
Bis (4-dicyanatophenyl) methane, 2,2-bis (4-cyanatophenyl) propane, 2,2-bis (3,5-dibromo-4
-Cyanatophenyl) propane, bis (4-cyanatophenyl) ether, bis (4-cyanatophenyl) thioether, bis (4-cyanatophenyl) sulfone, tris (4-cyanatophenyl) phosphite, tris ( 4-cyanatophenyl) phosphate, and cyanates obtained by reacting novolak with cyanogen halide.

In addition to these, Japanese Patent Publication Nos. 41-1928 and 43-184
68, 44-4791, 45-11712, 46-1112, 47-26853
And polyfunctional cyanate compounds described in JP-A-51-63149 and the like can also be used. These can be used alone or 2
Used in combination of more than one species. The content of impurities such as hydrolyzable Cl and Na in these components is extremely small, and by mixing them as one component of the present invention, the total amount of impurities is reduced, making them ideal as semiconductor peripheral materials.

Further, a prepolymer having a molecular weight of 200 to 6,000 having a triazine ring formed by trimerization of a cyanato group of these polyfunctional cyanate compounds is used. The prepolymer is prepared by converting the above-mentioned polyfunctional cyanate monomer into an acid such as a mineral acid or a Lewis acid;
Bases such as sodium alcoholates and tertiary amines;
It can be obtained by polymerization using a salt such as sodium carbonate as a catalyst. The prepolymer contains a part of the monomer and is in the form of a mixture of the monomer and the polymer. Such a raw material is suitably used for the purpose of the present invention. The component (a) in the composition is 10 to 80% by weight,
Preferably it is 20 to 70% by weight. If the amount is too small, heat resistance, moisture absorption and electric insulation after pressure cooker are insufficient, and if the amount is too large, problems such as insufficient pre-curing with active energy rays occur.

The (b) unsaturated compound containing an alicyclic epoxy group of the present invention is a compound having a radically polymerizable unsaturated group and an alicyclic epoxy group in the molecule. Specifically, 3,4-epoxycyclohexylmethyl acrylate which is an acrylic acid ester of epoxycyclohexanemethanol
(Product name: Cyclomer A2, manufactured by Daicel Chemical Industries, Ltd.)
00), 3,4-epoxycyclohexylmethyl methacrylate (manufactured by Daicel Chemical Industries, Ltd., trade name: Cyclomer M100) which is a methacrylate of epoxycyclohexanemethanol, and those represented by the following general formula: It is suitable. Further, compounds described in JP-A-01-2899820 can also be used. The component (b) in the composition is used in an amount of 20 to 90% by weight, preferably 25 to 80% by weight.

[0011]

Embedded image (In the formula, R ¹ is a hydrogen atom or a methyl group, and R ² has 1 to 20 carbon atoms.
Represents an alkylene group)

The photopolymerization initiator (c) of the present invention comprises a radical photopolymerization initiator, which is used to polymerize the radically polymerizable unsaturated group of the component (b) with light. In order to polymerize the alicyclic epoxy group of the component with light, a cationic photopolymerization initiator is used. Examples of the radical photopolymerization initiator include α-diketones such as benzyl and diacetyl, acyloins such as benzoyl, acyloin ethers such as benzoin methyl ether, benzoin ethyl ether and benzoin propyl ether, thioxanthone, and 2,4- Thioxanthones such as diethylthioxanthone, benzophenone, 4,4'-bis (dimethylamino)
Benzophenones such as benzophenone, acetophenone, acetophenones such as 2,2'-dimethoxy-2-phenylacetophenone and p-methoxyacetophenone, quinones such as anthraquinone and 1,4-naphthoquinone, di-t-butyl peroxide and the like. A peroxide or the like is used alone or in combination of two or more.

Examples of the cationic photopolymerization initiator include aromatic sulfonium salts, (η ⁵ -2,4-cyclopentadien-1-yl) [(1,2,3,4,5,6-η) -(1-methylethyl)
An iron complex represented by [benzene] -iron (1 +)-hexafluorophosphate (1-) is exemplified,
More than seeds are used. The photopolymerization initiator is used in an amount of 0.1 to 20% by weight, preferably 0.5 to 15% by weight.

The (d) thermosetting catalyst of the present invention is mainly used for promoting the reaction of the cyanato group of the component (a). As this catalyst, for example, zinc octylate, tin octylate,
Examples of known thermosetting catalysts of polyfunctional cyanate compounds such as iron acetylacetone, dibutyltin dioctoate, and cobalt naphthenate are exemplified. The amount used is 0.005 to 5% by weight, preferably 0.01 to 3% by weight.

The active energy ray precurable thermosetting resin composition of the present invention, which contains the above-mentioned components as essential components, may contain various additives as required within a range that does not impair the inherent properties of the composition. can do. These additives include polyfunctional liquid or solid epoxy resins; polyfunctional maleimides; polyimides; unsaturated polyesters,
Polymerizable double bond-containing monomers such as (meth) acrylates and prepolymers thereof; polybutadiene, epoxidized butadiene, maleated butadiene, butadiene-acrylonitrile copolymer and its carboxyl group-containing resin, polychloroprene, butadiene-styrene Low molecular weight liquid to high molecular weight elastic rubbers such as copolymers, polyisoprene, butyl rubber, fluoro rubber, and natural rubber;
Polyethylene, polypropylene, polybutene, poly-4-
Methyl pentene, polystyrene, AS resin, ABS resin, polyethylene-propylene copolymer, tetrafluoroethylene-hexafluoropropylene copolymers; high molecular weight polymers such as polycarbonate, polyphenylene ether, polysulfone, polyester, polyphenylene sulfide and the like; Examples of a molecular weight prepolymer or oligomer; polyurethanes and the like are used as appropriate. When these compounds are blended, the curing agent and the catalyst can be appropriately added.

Other known inorganic and organic fillers, dyes, pigments, thickeners, lubricants, defoamers, dispersants, leveling agents, coupling agents, photosensitizers, flame retardants, brighteners , Polymerization inhibitors, various additives such as thixotropic agents,
They are used in combination as needed. If necessary, the compound having a reactive group is appropriately blended with its curing agent and catalyst. The active energy ray precurable thermosetting resin composition of the present invention can be used in any state of a liquid non-solvent, a solution dissolved in a solvent, or a solution dispersed in a suspension. A generally known solvent can be used.

The method of applying the resin composition of the present invention on a printed wiring board or the like includes a roll coater method, a screen printing method, a bar coater method, a spray coater method and the like.
It can be carried out by generally known methods. After the application, when applied as a solution, the solvent is removed by heating and drying. General equipment such as a hot air drying oven can be used for drying. Temperature is 60
~ 200 ° C, preferably 80-160 ° C. The time varies depending on the amount of the catalyst and the like, but is generally 20 minutes to 2 hours, preferably 30 to 60 minutes.

The resin composition of the present invention is pre-cured by an active energy ray and then post-cured by heat. As a light source of an active energy ray for pre-curing the active energy ray pre-curable thermosetting resin composition of the present invention,
Low-pressure mercury lamp, medium-pressure mercury lamp, high-pressure mercury lamp, ultra-high-pressure mercury lamp,
A quinocene lamp, a metal halide lamp, or the like is used. Exposure amount 100 to 2000 mJ / cm ^2, preferably 200 to
1000 mJ / cm ² . In addition, an electron beam, a laser beam, or the like may be used. The resin composition of the present invention is used after being pre-cured with light and then post-cured with heat as it is.In some cases, after photo-curing, the uncured portion is dissolved and removed using an organic solvent and then heated. Can be post-cured.

The conditions for curing the active energy ray precurable thermosetting resin composition of the present invention with heat are as follows:
C., preferably at 120 to 200.degree. C., for 30 minutes to 2 hours, preferably 45 minutes to 60 minutes.

[0020]

The present invention will be specifically described below with reference to examples and comparative examples. In addition, “parts” indicates parts by weight unless otherwise specified. Examples 1 to 3 and Comparative Examples 1 to 3 The components described below are appropriately blended as shown in Table 1, and the active energy ray precurable thermosetting resin composition of the present invention, and for comparison Was prepared. Using the obtained resin composition, line / space = 70 μm
/ 70 [mu] m of comb pattern, the copper-clad laminate, is applied onto the laminate, after skipping those containing solvent and dried 20 minutes at 80 ° C. the solvent, 160 ° C. The ultraviolet rays are irradiated 700 mJ / cm ² For 60 minutes. The properties of this coating film are shown in Table 2.

Component (a): Synthesis of polyfunctional cyanate prepolymer Synthesis Example 1 1,000 parts of 2,2-bis (4-cyanatophenyl) propane
The mixture was melted at 50 ° C. and reacted with stirring for 6 hours to obtain a solid prepolymer (component a-1). This was dissolved in ethyl acetate to form a solution. Synthesis Example 2 1,000 parts of 1,4-dicyanatobenzene was melted at 140 ° C.
The mixture was reacted for 2 hours with stirring to obtain a viscous prepolymer (component a-2).

Component (b): alicyclic epoxy group-containing unsaturated compound 3,4-epoxycyclohexylmethyl acrylate (component
b-1) and 3,4-epoxycyclohexylmethyl methacrylate (component b-2) were used. Component (c): Photopolymerization initiator 2-methyl-1- (4-methylthio-phenyl) -2-morpholinopropan-1-one (component c-1) as a radical photopolymerization initiator, cationic light As the polymerization initiator, (η ⁵ -2,4-
Cyclopentadien-1-yl) [(1,2,3,4,5,6-η)-(1-
Methylethyl) benzene] -iron (1 +)-hexafluorophosphate (1-) (component c-2) was used. Component (d): heat curing catalyst Zinc octylate (component d-1) was used.

As an additional component other than the above, as an epoxy resin, a cresol novolak type epoxy resin (trade name: ESCN-220F, manufactured by Sumitomo Chemical Co., Ltd.) (component
e-1), dicyandiamide (component f-1) as a curing agent, and 2-ethylimidazole (component g-1) as a catalyst were appropriately used.

[0024]

[Table 1] Component a-1 a-2 b-1 b-2 c-1 c-2 d-1 e-1 f-1 g-1 Example 1 25 60 7 3 0.05 5 〃 250 43 5 2 0.1 〃 3 70 25 3 2 0.3 Comparative Example 1 100 3 1 0.5 〃 2 100 10 5 ３ 3 43 5 50 5 1

The properties of the obtained coating film were evaluated by the following methods. Pencil hardness: Evaluation was performed according to JIS K5400. Adhesion: According to JIS K5400, 100 1-mm squares were formed on a test piece, a peeling test was performed with a cellophane tape, and the peeling state was observed. Heat resistance: After immersion in a solder bath at 260 ° C. for 30 seconds, the presence or absence of abnormality in the coating film was visually observed. Glass transition temperature: A 0.5mm thick plate is created by applying multiple layers of coating, and DMA (Differential Mechanical Analys
is).

Chemical resistance: After irradiating with 1,000 mJ / cm ^{2 of} ultraviolet rays, it was immersed in methyl ethyl ketone for 1 minute to check for dissolution. Insulation resistance: Measurement of electrical insulation after moisture absorption and pressure cooker treatment. Using a test piece applied to the comb pattern described above,
After 500 hours of treatment at 25% RH, leave it in an atmosphere of 25 ° C and 60% RH for 10 minutes (after absorbing moisture), and after treating for 200 hours at 121 ° C and 2 atm.
After leaving in a 60 ° C / 60% RH atmosphere for 90 minutes (after PCT), and 85 ° C
・ Apply 100V under 85% RH atmosphere, and after 200 hours (M
The value of the insulation resistance after CT) was measured.

[0027]

[Table 2] Example Comparative example Measurement items 1 2 3 1 2 3 Pencil hardness 6H 6H 6H 6H 6H 6H Adhesion (on copper foil) 100/100 Same as left Same as left 100/100 Same as left Same as left (on board) Same as left 100/100 Same as left 100/100 Same as left Same as left Heat resistance (normal) ○ ○ ○ ○ ○ ○ (after boiling for 2 hours) ○ ○ ○ ○ × × Glass transition temperature (° C) 157 188 213 180 98 144 Chemical resistance ○ ○ ○ × ○ ○ Insulation Resistance (Ω × 10 ¹⁰ ) After moisture absorption 20 60 100 400 3 40 After PCT 3 4 10 70 0.8 1 After MCT 10 40 70 100 0.07 0.9

[0028]

The active-energy-ray precurable thermosetting resin composition of the present invention is rapidly cured by active energy rays and heat, and the resulting coating film has heat resistance, adhesion, and resistance to heat. Excellent chemical properties, migration resistance, moisture absorption and electrical insulation after pressure cooker treatment,
Suitable for use as a permanent protective coating.

Claims (2)

[Claims] (A) a polyfunctional cyanate compound or 10 to 80% by weight of the cyanate ester prepolymer;
(b). 20 to 90% by weight of an alicyclic epoxy group-containing unsaturated compound, (c). 0.1 to 20% by weight of a photopolymerization initiator and (d). 0.005 to 5% by weight of a thermosetting catalyst as essential components. An active energy ray precurable thermosetting resin composition comprising: 2. The active energy ray precurable thermosetting resin composition according to claim 1, wherein the component (b) is represented by the following general formula. Embedded image (In the formula, R ¹ is a hydrogen atom or a methyl group, and R ² has 1 to 20 carbon atoms.
Represents an alkylene group)