JPH0275676A - Thermosetting epoxy resin varnish - Google Patents

Abstract

PURPOSE:To improve stability near room temp. and curing properties at a high temp. by compounding an epoxy resin, a polyphenol, a specific compd. and a solvent. CONSTITUTION:An epoxy resin, a polyphenol (e.g., polymeric cresol novolac resin of with number average MW of 1500 or more) in an equivalent ratio the hydroxyl group of said polyphenol to the epoxy group of said epoxy resin of (0.5:1)-(2.0:1), and 0.01-20 pts.wt. (based on 100 pts.wt. said epoxy resin) N-(imidazolylalkyl)-urea or N-(imidazolylalkyl)amine compd. [e.g., N-(2- methylimidazolyl-1-ethyl)-urea] are dissolved in 10-1000 pts.wt. (based on 100 pts.wt. the sum of said epoxy resin and said polyphenol) solvent capable of dissolving the above-mentioned three components (e.g., acetone).

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to a thermosetting epoxy resin face, particularly at room temperature to
It relates to a one-component type face that is extremely stable up to 50°C and has fast curing properties at high temperatures.

The so-called one-component type FES is used for resistive pastes and conductive pastes that form electric circuits, solder resists used when manufacturing circuit boards, and adhesives used in heat-press bonding, which are provided in a semi-cured B-stage state. It can be advantageously used in manufacturing, etc.

[Conventional technology]

Resistive pastes and conductive pastes that form electric circuits, solder resists used when manufacturing circuit boards, adhesives that are provided in a semi-cured 8-stage state and used for heat compression bonding, and fiber-reinforced laminates. Epoxy resins have traditionally been used.

In particular, it is known that when an epoxy resin and polyphenol are combined, a highly reliable epoxy resin face with excellent heat resistance and water resistance can be obtained. A compound consisting of an epoxy resin and a polyphenol compound reacts very slowly and is stable at room temperature, but the curing speed is slow even at high temperatures, so a curing accelerator is added to achieve practical fast curing at high temperatures. is normal.

[Wire waste that the invention attempts to solve]

As such curing accelerators, tertiary amine imidazole compounds, phosphorus compounds, etc. are known, but when curing accelerators are usually added, stability at room temperature is lost, resulting in so-called -liquid type festivals and pastes. It was difficult to create a laminate material with good prepreg stability.

An object of the present invention is to provide an epoxy resin face that has good stability near normal temperatures and reacts rapidly at high temperatures.

[Means to solve the problem]

The present invention has solved the above problems as follows: 0.5 to 2.0% polyphenol per equivalent of epoxy resin.
0 equivalent, 0.01 to 20 parts by weight of N-(imidazolylalkyl)urea or N-(imidazolylalkyl)amide compound per 100 parts by weight of epoxy resin, and the solvent for dissolving these compounds is the sum of the epoxy resin and polyphenol. The present invention provides a thermosetting epoxy resin face containing 10 to 1000 parts by weight per 1 part of 11 oz.

A wide variety of epoxy resins can be used in the present invention. For example, bisphenol A1 bisphenol F, bisphenol S1 phenol novolac,
Epoxy resins produced from epihalohydrin and polyphenols such as O-cresol novolac, tris(4-hydroxyphenyl)methane, and 1,1,2.2-f trakis(4-hydroxyphenyl)ethane; catechol, resorcinol, and Epoxy resins manufactured from polyhydric phenols such as droquinone and epihalohydrin; glycidyl ether type epoxy resins of polyhydric alcohols such as ethylene glycol, butanediol, pentaerythritol, and polyethylene glycol, herring clopentadiene dioxide, 3,4-epoxy cyclohexylmethyl-3,4-epoxycyclohexanecarboxylate,
Alicyclic epoxy resins such as vinyl cyclohexene dioxide; polyglycidyl ester-type epoxy resins of polycarboxylic acids such as phthalic acid and hexahydrophthalic acid; polyglycidylamines such as glycidylated products of diamino diphenylmethane; glycidylated products of aminophenols, etc. Epoxy resin fails. Further, as the epoxy resin, various flame-retardant epoxy resins containing a halogenated aromatic nucleus can be used. If such a flame-retardant epoxy resin is used, the cured resin from the festival can be rendered flame-retardant. Examples of the flame-retardant epoxy resin containing such a halogenated aromatic nucleus include glycidyl ether of tetrabromobisphenol A, glycidyl ether of frominated phenol novolak resin, and the like.

Among these, to increase heat resistance, glycidyl ether of novolak obtained by reacting phenol or cresol with formaldehyde, glycidyl ether of polyphenol obtained by reacting matahaphenol or cresol with salicylaldehyde, vanillin, or terephthalaldehyde. It is recommended to use Glycidyl ether of novolak obtained by reacting bisphenol with formaldehyde is also good. Particularly low viscosity
To increase thermal stability and heat resistance, 4+4'-dihydro aQ
Preferably, an epoxy resin made from C3e3'#414'-tetramethylbiphenyl and epihalohydrin is used.

The polyphenols used in the present invention include phenol,
Alkyl-substituted phenols, such as 0-cresol, p
Examples include phenol novolak resins obtained by condensing phenols such as -cresol, t-butylphenol, cumylphenol, and vinylphenol with formaldehyde under an acidic catalyst. Especially when the number average molecular weight is 15
It is preferable to use a high molecular weight cresol novolac resin having a molecular weight of more than 0.00, since this increases heat resistance and thermal stability.

In addition, phenol, substituted phenol, and aldehydes other than formaldehyde, such as salicylaldehyde,
Vanillin, terephthalaldehyde, benzaldehyde,
Boriax/-ol compounds condensed with crotonaldehyde, cryoxal, etc. in the presence of an acidic catalyst, polyphenols condensed with resorcinol or hydroquinone bisphenol A and formaldehyde, polymers of vinylphenol or impropenylphenol, or polymers with these compounds. Examples include polyphenols, which are copolymers with compounds having sexually unsaturated groups.

The polyphenol is blended at a ratio of 0.5 to 2.0 equivalents, preferably 0.7 to 1.5 equivalents of OH groups per 1 equivalent of epoxy groups in the epoxy resin.

The N-(imidazolyl-1-alkyl) urea or amide compound used together with the epoxy resin and polyphenol in the thermosetting epoxy resin varnish of the present invention is a urea or amide derivative of imidazole;
It is a compound substituted with an alkyl group having a urea or amide bond at the position thereof, such as an imidazole compound represented by the following general formula (1) or (If).

[In the formula, R1-R4 represent a hydrogen atom, an alkyl group, or an aryl group, X represents -NHC-NH2, and Y represents a carboxylic acid residue.] n and m are integers of 1 to 10 . ] These imidazole compounds are thought to act as a curing accelerator. By using these imidazoles, the varnish becomes a liquid varnish that is stable at around room temperature and hardens quickly at high temperatures.

Moreover, the prepreg for laminates produced using this varnish is stable at around room temperature and cures quickly when molded in a press.

Specific examples of the compound represented by the general formula (1) include N-(2-methylimidazolyl-1-difyb)RL
N-(2-phenylimidazolyl-1-ethyl)urea, N-(2-undecylimidazolyl-1-ethyl)
Urea, N-(2-ethel 4-methylimidazolyl-1-
Examples include ethyl)urea, N-(2-methylimidazolyl-1-propyl)urea, and the like.

In the compound represented by the general formula (1), Y is -N
Compounds that are HCN&-, i.e., N,N'-substituted imidazole compounds of urea, include N,N'-bis-(2-methylimidazolyl-1-ethyl)urea, N,N'-bis-(2-phenyl imidazolyl-1-ethyl) Urine L
N,N'-bis-(2-undecylimidazolyl-l-
ethyl) urea, N, N'-bis-(2-ethyl-4-methylimidazolyl-1-ethyl") ffl element, N, N
'-bis-(2-methylimidazolyl-1-propyl)
Examples include urea.

Examples of imidazole compounds in which Y is a divalent carboxylic acid amide residue include N,N'-(2-methylimidazolyl-l-ethyl)-adipoyldiamide, N,N'-
(2-Phenylimidazolyl-1-ethyl)-adipoyldiamide, N,N'-(2-undecylimidazolyl-1-ethyl)-adipoyldiamide, N,N'-(2
-Ether-4-methylimidazolyl-1-ethyl)-adipoyldiamide, N,N'-(2-methylimidazolyl-1-ethyl)-sepatyldiamide, N,N'-(2
-Methylimidazolyl-1-ethyl-phthalic acid diamide, N,N'-(2-methylimidazolyl-1-propyl)-al)-trimellitic acid trisamide, N,N',
d'-(2-undecylimidazolyl-1-ethyl)-
trimellitic acid trisamide, N, N-N':N'''-
Examples include (2-methylimidazolyl-1-ethyl)-pyromellitic acid tetraamide.

Among these, the urea compound represented by the general formula (1) or the urea N represented by the general formula (If)
, N'-substituted imidazole or N , N'-substituted imidazole of divalent carboxylic acid diamide is preferred.

Among them, especially N-(2-methylimidazolyl-1-
ethyl)urea, N,N'-(2-methylimidazolyl-
1-ethyl)-adipoyldiamide is preferred, and furthermore N-(2-methylimidazolyl-1-ethyl)urea, N
-(2-phenylimidazolyl-1-ethyl)urea, N
-(2-')ntecylimidazolyl-1-ethyl)urea is more preferred.

The imidazole compound is used in an amount of 0.01 to 20 parts by weight, preferably 0.2 to 5 parts by weight, per 100 parts by weight of the epoxy resin.

Preferable solvents for the present invention include ketones such as acetone, methyl ethyl ketone, methyl imbutyl ketone, and cyclohexanone; glycols such as methoxyethanol, ethoxyethanol, butoxycetanol, methoxyethoxyethanol, ethoxyethoxyethanol, and butoxyethoxyethanol. Ethers; esters such as methyl acetate, ethyl acetate, methoxyethanol acetate, ethoxyethanol acetate, butoxycetanol acetate, methoxyethoxyethanol acetate, ethoxyethoxyethanol acetate, butoxyethoxyethanol acetate;
Examples include alkyl alcohols such as methyl alcohol, ethyl alcohol, flobyl alcohol, and butyral alcohol. These solvents may be used alone, or in some cases, two or more types may be used in combination. ~1
．． 000 weight parts, preferably 20-3o.

In the heavy clothing section.

This varnish contains metal powders such as steel powder, silver powder, aluminum powder, and carbon black that provide conductivity, and fillers used in the manufacture of paints and pastes such as mica, talc, silica, calcium carbonate, alumina, etc. Category: Mixing. Furthermore, flame retardants such as antimony trioxide, antifoaming agents such as silicone resins, etc. can be contained as necessary.

In addition, to impart flexibility, rubber components such as butadiene acrylonitrile polymers, polybutadiene and polybutadiene acrylonitrile having carboxyl groups, silicone resins, polyvinyl butyral, nylon resins, etc. may be added. I'll come.

〔Effect of the invention〕

The epoxy resin varnish of the present invention is stable at room temperature and cures quickly at high temperatures, so it is useful as a liquid varnish, paste, or adhesive.

Furthermore, the varnish of the present invention is stable at room temperature, and semi-cured B-stage prepregs, such as prepregs for laminates, are also stable at room temperature. It can be advantageously used in manufacturing reinforced laminates and the like. For example, the varnish of the present invention is impregnated into a base material such as glass cloth, glass non-woven fabric, polyester cloth, polyester non-woven fabric, asbestos paper, capobon fiber cloth, etc. and then dried or semi-cured to form a prepreg, and this prepreg is formed into a single layer. , or laminated and molded by heating and pressing.
By curing it, a molded article with excellent heat resistance and strength can be obtained.

In particular, if one or more of the prepregs described above are laminated with steel foil on one or both sides and hot pressed to form a steel clad laminate and etched to form a circuit, a single layer printed wiring circuit board can be obtained. By stacking several such circuit boards with the prepreg interposed in between and hot pressing, a multilayered printed wiring circuit board can be obtained. Manufacturers who draw circuits often purchase and press prepregs for multilayer laminates, and the stability of the prepregs is particularly important.

[Examples, etc.]

The present invention will be explained in more detail below using experimental examples.

Synthesis Example 1 O-cresol 10B? , paraformaldehyde 3
21 and ethyl seronulp 240 ft: 10 t of sulfuric acid
The mixture was charged into a reactor, and the reaction was carried out at 115° C. for 4 hours with stirring.

After the reaction was completed, 179 of Na HCOs and 3 of water were added to neutralize, and then the reaction solution was poured into 2 of water under high speed stirring, and the precipitated resin was separated from F and dried, resulting in 1152 of Talesol. A novolak resin was obtained.

This resin was soluble in methanol, ethanol, butanol, octatool, methyl cellosolve, ethyl cellosolve, tetrahydrofuran, dioxane, acetone, methyl ethyl ketone, and ethyl acetate, and no gel content was observed. However, it was insoluble in benzene, toluene, xylene, chloroform, and carbon tetrachloride.

The molecular weight of this resin was determined by the steam method (in methyl ether ketone,
When measured at 40°C (the same applies hereafter), the number average molecular weight was 2600. The softening point of the resin determined by microscopy was 155°C. Furthermore, the Q
The value was 3.0. The hydroxyl equivalent was 120.

Example 1 Glycidyl ether of phenol novolac resin (Epicote 154 epoxy equivalent 178, trade name of Yuka Shell Epoxy Co., Ltd.) 6 (1) Glycidyl ether of brominated phenol novolac (prene epoxy equivalent [3287,
Including Brom! t36%, Nippon Kayaku Co., Ltd. trade name) 40 parts, phenol novolak resin (Tamanol 752, hydroxyl group equivalent weight 104, part chemical trade name) 50 parts, N,N'-bis-(
An epoxy varnish was prepared by dissolving 1.5 parts of 2-methylimidazolyl-1-ethyl)urea in 65 parts of n-ethylcarpitol.

Finely powdered silica (Japan Aerosil Co., Ltd. product name 38) is added to this varnish.
0) 4 parts, 20 parts of talc, 0.5 parts of antifoaming agent (Nippon Unicar Co., Ltd. trade name 2-722), Phthalocyanine Green 3
A mixed ML router resist was prepared using three rolls. This ink was screen printed onto a steel through-hole epoxy substrate (XSO mesh polyester plate,
Emulsion J120μ) was applied to give a film thickness of approximately 25μ, and the coating was cured by heating at 175°C for 60 minutes to obtain a copper-clad printed wiring board having a protective film.

This solder resist ink is kept at 40℃ for about 6 months at 20℃.
However, it maintained stable and sufficient printability for two months.

Table 1 shows the properties of the protective film.

Comparative Example I Soldering was carried out in the same manner as in Example 1, except that 1.0 part of BF, 2-methylimidazole salt was used instead of N,N'-bis-(2-methylimidazolyl-1-ethyl)urea. A resist ink was prepared. BFa 2-methylimidazole salt has traditionally been said to have good stability at room temperature and harden quickly at high temperatures, but it still cures at 20°C for 3 months and 4 months.
At 0°C, it was stable for only one month, after which time the viscosity increased, the screen printability deteriorated, and the properties of the protective film also deteriorated.

Also, since it was a salt, the insulation resistance between the lines at high temperatures decreased.

The results are shown in Table-1.

Example 2 Brominated bisphenol A type epoxy resin (Epicoat 1045 epoxy equivalent weight 450, bromination rate 21%,
60 parts of Yuka Shell Epoxy (trade name), 40 parts of brominated phenol novolak resin (Frene epoxy equivalent: 287, bromine content: 36%, Nipponka brand name), phenol novolac resin (Tamanol 752, hydroxyl group #104, Kagaku Co., Ltd.) 28 parts of N,N'-(bis-2-methylimidazolyl-1-ethyl)urea were blended together and dissolved in 105 parts of a mixed solvent of methyl ether ketone and ethyl cellosolve in a weight ratio of 2 parts and 1. An epoxy resin varnish was prepared.

This varnish was impregnated into a silane-treated plain woven glass cloth having a thickness of 0.18 m and heated at 140° C. for 5 minutes to produce a B-staged prepreg.

This prepreg is stable for 6 months at 20℃ and 2
It remained stable for several months. Copper foil with a thickness of 35 μm was layered on both sides of these 8 sheets of prepreg, and heated at 175°C for 60 minutes.
It was molded under heat and pressure of A9/d to obtain a copper-clad laminate with a thickness of 1.6-0. The characteristics are shown in Table 2.

Example 3 N,N'-(2-methylimidazolyl-1-ethyl)-adipoyldiamide was used instead of N,N'-bis-(2-methylimidazolyl-1-ethyl)urea as a curing accelerator.2. A prepreg was prepared in the same manner as in Example 2 except that 0 part was used, and the prepregs were stacked and pressed to obtain a copper-clad laminate.

The prepreg was stable at 20°C for 6 months and at 40°C for 2 months.

The properties of the laminate are shown in Table 2.

Example 4 As a curing accelerator, 1.5 parts of N-(2-methylimidazolyl-1-ethyl)urea was used in place of N,N'-bis-(2-methylimidazolyl-1-ethyl)urea. A prepreg was prepared in the same manner as in Example 1, and the prepregs were stacked and pressed to obtain a copper-clad laminate. The prepreg was stable at 20°C for 6 months and at 40°C for 2 months. The properties of the laminate are shown in Table 2.

Example 5 Among the epoxy resin varnish components of Example 2, Synthesis Example 1 was used instead of the phenol novolak resin as the polyphenol.
A varnish was produced in the same manner except that 33 parts of the high molecular weight cresol novolak resin produced in Example 1 was used. Also, Example 2
Gripreg and copper-clad laminates were manufactured in the same manner as above. Gripreg was stable at 20°C for 6 months and at 40°C for 2 months.

The properties of the laminate are shown in Table 2.

Comparative Example 2 1-cyanoethyl- instead of N,N'-bis-(2-methylimidazolyl-1-ethyl)urea as a curing accelerator
An epoxy resin varnish was produced in the same manner as in Example 1, except that 1.5 parts of 2-undecylimidazole was used. Since the prepreg gels too quickly when heated to 140°C, it was heated at 120°C for 5 minutes to produce a B-staged prepreg. This prepreg was stable at 20°C for 2 months and at 40°C for 1 week. A copper-clad laminate was manufactured from this prepreg in the same manner as in Example 2. Table of characteristics -
Shown in 2.

(Margin below)

Claims (1)

[Claims] Polyphenol 0.5 to 1 equivalent of epoxy resin
2.0 equivalents, 0.01 to 20 parts by weight of N-(imidazolylalkyl)urea or N-(imidazolylalkyl)amide compound per 100 parts by weight of epoxy resin, and a solvent for dissolving these compounds is a mixture of epoxy resin and polyphenol. A thermosetting epoxy resin varnish containing 10 to 1000 parts by weight based on 100 parts by weight of the total amount.