JPS6325607B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a flame-retardant epoxy resin composition used for adhesives, molding materials, laminates, etc. BACKGROUND ART In recent years, the integration and performance of electronic devices have become remarkable, and along with this, the requirements for various performances such as heat resistance, dimensional stability, and moisture resistance of the materials and components used therein have become stricter. Furthermore, from the viewpoint of preventing electrical fires, these materials and parts are also required to be flame retardant. However, it is extremely difficult to achieve both high performance and flame retardancy, and the current situation is that it is unavoidable that performance will deteriorate to some extent when flame retardance is achieved. For example, glass epoxy copper-clad laminates that require particularly high heat resistance use brominated epoxy resins to make them flame retardant, but the desorption of bromine, which is effective in imparting flame retardance, occurs at relatively low temperatures. The generated gas accumulates between the copper foil and the base material, causing blistering and peeling of the copper foil. That is, the problem is that the adhesiveness between the base material and the copper foil deteriorates even though the strength of the base material is sufficiently maintained. In view of the current situation, the inventors of the present invention have conducted extensive studies on epoxy resin compositions that are flame retardant and have good heat resistance. As a result, the present inventors have developed a copolymer containing a halogenated epoxy resin and isopropenylphenol as a curing agent as one component. In a heat resistance test at 200°C, a copper-clad laminate made using a composition containing a small amount of aromatic diamine and a small amount of aromatic diamine hardly caused the blistering of the copper foil seen in conventional flame-retardant glass-epoxy copper-clad laminates. After further research, they finally completed the present invention. That is, the present invention provides a halogenated epoxy resin or a mixture of a halogenated epoxy resin and an epoxy resin.
A flame-retardant epoxy resin composition characterized by blending 100 parts by weight with 50 to 150 parts by weight of a copolymer containing isopropenylphenol as a curing agent and 0.1 to 5 parts by weight of an aromatic diamine. It is. The halogenated epoxy resin used in the present invention is a so-called halogen atom-substituted epoxy resin consisting of a commonly used compound having at least two epoxy groups in one molecule. Namely, bisphenol-based epoxy resins, novolak-based epoxy resins, polyphenol-based epoxy resins, polyhydroxybenzene-based epoxy resins, polyglycol-based epoxy resins, aromatic and aliphatic carboxylic acid-based epoxy resins, alicyclic epoxy resins, etc. It is a halogen atom-substituted product of general epoxy resins such as nitrogen epoxy resins and metal-containing epoxy resins. Among them, preferred examples include bromine-substituted bisphenol epoxy resins and bromine-substituted alicyclic epoxy resins. These halogenated epoxy resins may be used alone or in combination of two or more. Moreover, if necessary, it can be used in combination with a general epoxy resin. Note that any of the general epoxy resins mentioned above can be used in the present invention. The amount of halogenated epoxy resin to be used is determined depending on the properties required for the cured product.
Generally, the halogen content in the composition is 8 to 25% by weight, preferably 10 to 20% by weight. The copolymer containing isopropenylphenol as one component (hereinafter abbreviated as isopropenylphenol polymer) used in the present invention is a copolymer of isopropenylphenol and one or more polymerizable monomers. . Examples of polymerizable monomers that can be used include styrenes such as styrene, α-methylstyrene, chlorostyrene, bromustyrene, vinyltoluene, and vinylxylene, methyl acrylate, ethyl acrylate, n-butyl acrylate, Acrylic esters such as 2-ethylxyl acrylate, methacrylic esters such as methyl methacrylate, ethyl methacrylate, and n-butyl methacrylate, unsaturated nitriles such as acrylonitrile, methacrylonitrile, fumaronitrile, etc. ,
Acrylic acid, methacrylic acid, maleic anhydride, acrylamide, methacrylamide, isoprene,
Examples include butadiene and cyclopentadiene. Further, the isopropenylphenol used may be used alone or in a mixture of two or more of ortho, meta or para forms. Particularly preferred is P
-isopropenylphenol. The amount of isopropenylphenol component in the isopropenylphenol-based polymer may vary depending on the blending ratio with the epoxy resin, but is usually between 20 and 80%.
% by weight, preferably 25-75% by weight. As isopropenylphenol polymers,
A copolymer containing isopropenylphenol and acrylonitrile is preferred because it provides excellent flame retardancy and heat resistance. In this copolymer containing acrylonitrile and isopropenylphenol, the content of acrylonitrile and isopropenylphenol is 20 to 40% by weight, preferably 20 to 35% by weight in the copolymer for acrylonitrile.
% by weight, and for isopropenylphenol it is 20-80% by weight in the copolymer, preferably 25-75% by weight.
Weight%. Copolymers within this range are particularly preferred since they are flame retardant and provide cured products with excellent flame resistance, solvent resistance, and chemical resistance. Furthermore, the isopropenylphenol-based polymer used in the present invention is preferably a copolymer of isopropenylphenol, acrylonitrile, and styrene, and the isopropenylphenol component is 20 to 80% by weight, preferably 25 to 75% by weight. %, the acrylonitrile component is 20-40% by weight, preferably 20-35% by weight, and the styrene component is 1-40% by weight.
Particularly preferred is 60% by weight, preferably 2-50% by weight. By using this isopropenylphenol polymer in the present invention, it is possible to obtain a cured product that has even more excellent flame retardancy, good heat resistance, and excellent solvent resistance and chemical resistance. Further, in the present invention, the molecular weight of the isopropenylphenol polymer is 300 to 200,000, preferably 500
~50000 is desirable. less than 300 or
If it exceeds 200,000, it will not be possible to obtain a composition that is flame retardant and has excellent heat resistance as the object of the present invention. The amount of isopropenylphenol polymer used is 50 to 150 parts per 100 parts by weight of brominated epoxy resin or a mixture of brominated epoxy resin and epoxy resin.
The parts by weight are appropriate, and it is usually desirable to adjust the amount to 0.7 to 1.5 moles of phenolic hydroxyl groups in the isopropenylphenol polymer per mole of epoxy groups in the composition. If the amount of the isopropenylphenol polymer used is less than 50 parts by weight or more than 150 parts by weight, either flame retardancy or heat resistance will deteriorate. The aromatic diamine used in the present invention includes:
Diaminodiphenylmethane, dihalogenated diaminodiphenylmethane, tetrahalogenated diaminodiphenylmethane, diaminodiphenyl sulfone, diaminophenyl ether, m-phenylenediamine, P-phenylenediamine, diaminodiphenylpropane, diaminodiphenyl methane Nilsulfide, di(P-aminophenoxy)benzene, diaminodiphenyl ether disulfonamide, diaminodiphenylmethane dicarbonamide, diaminodiphenylmethane disulfonamide, sulfanilamide, dinitrodiaminodiphenyl ether, dinitrodiaminodiphenylmethane, etc. These can be used singly or in a mixture of two or more. Preferred among these aromatic diamines are diaminodiphenylmethane, diaminodiphenyl sulfone, and the like. The aromatic diamine is used in an amount of 0.1 to 5 parts by weight, preferably 0.5 to 3 parts by weight, per 100 parts by weight of the epoxy resin. If it is less than 0.1 parts by weight, the addition has no effect, and if it is added in excess of 5 parts by weight, the heat resistance of the laminate, especially the heat resistance of the copper foil bonding strength, decreases. The composition of the present invention is prepared by mixing a halogenated epoxy resin or a mixture of a halogenated epoxy resin and an epoxy resin, an isopropenylphenol polymer, and an aromatic diamine, and if necessary, dissolves it in a solvent to form a varnish. Solvents used for making varnish include:
Alcohols such as methanol, ethanol, propanol, benzyl alcohol, diacetone alcohol, ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, ethers such as dioxane, tetrahydrofuran, methyl cellosolve, ethyl cellosolve, ethyl acetate,
Esters such as butyl acetate, dimethylformamide, dimethylacetamide, N-methyl-2-
Examples include nitrogen-containing solvents such as pyrosodone, aromatic hydrocarbons such as benzene, toluene, and xylene, and dimethyl sulfoxide. These solvents may be used alone or in combination of two or more. Although the composition of the present invention is sufficiently cured without a catalyst, a catalyst may be added if necessary.
Desirable curing accelerators include tertiary amines such as N,N-dimethylbenzylamine, triethylamine, and triethanolamine, nitrogen-containing heterocyclic compounds such as pyridine, piperidine, and imidazole, BF ₃ ·pyridine, and BF ₃ ·piperidine. ,BF ₃・
Examples include complex salts of Lewis acids and amines such as monoethylamine, and carboxylates of amines such as N,N-dimethylbenzylamine acetate and piperidine acetate. Other pigments, colorants, stabilizers, reinforcing agents, etc. may be added to the composition of the present invention. The composition of the present invention can be used after being molded into various shapes. For curing, normal epoxy resin curing conditions can be used. When the composition of the present invention is cured, it not only has excellent heat resistance but also excellent flame retardancy and is good in that it becomes a molded product having chemical resistance and solvent resistance. The present invention will be explained below with reference to Examples. In addition,
Parts and percentages are by weight unless otherwise specified. Reference example 1 [Production of isopropenylphenol polymer-
A] Charge 1000 parts of cyclohexanone into a reactor equipped with a stirrer, reflux condenser, and thermometer, and raise the temperature while stirring. When cyclohexanone started to reflux, 300 parts of P-isopropenylphenol,
370 parts of styrene, 330 parts of acrylonitrile, 35 parts of azobisisobutyronitrile, cyclohexanone
Start dropping 500 parts of the mixed solution. The dropwise addition was completed in 3 hours under reflux, and the reaction was continued for an additional 1 hour after the dropwise addition was completed. After the reaction was completed, unreacted monomers and cyclohexanone were removed under normal pressure and further under reduced pressure to obtain 960 parts of an isopropenylphenol polymer having a weight average molecular weight of 8,800 and a hydroxyl group equivalent of 446 g/eq.
The polymer obtained here is called Resin-A. Reference example 2 [Production of isopropenylphenol polymer-
B] Charge 1000 parts of cyclohexanone into a reactor equipped with a stirrer, reflux condenser, and thermometer, and raise the temperature while stirring. When cyclohexanone starts to reflux, add 500 parts of P-isopropenylphenol, 180 parts of styrene, 320 parts of acrylonitrile, 35 parts of azobisisobutyronitrile, and 500 parts of cyclohexanone.
Start dropping the mixed solution consisting of 1. A polymer having a weight average molecular weight of 8500 and a hydroxyl equivalent of 268 g/eq (hereinafter referred to as Resin-B) was obtained in the same manner as in Reference Example 1. Example 1 Brominated epoxy resin “YDB-400” (trademark,
Manufactured by Toto Kasei Co., Ltd., bromine content 49.1%, epoxy equivalent
397 g/eq, softening point 67.0°C) 82 parts, 18 parts of epoxy resin "Epikoat #828" (trademark, manufactured by Yuka Shell Co., Ltd., epoxy equivalent: 189 g/eq), 135 parts of resin-A prepared in Reference Example 1, Diaminodiph enylmethane 0.5
1 part was added to 210 parts of methyl ethyl ketone and uniformly dissolved while stirring at room temperature. 150℃ of this varnish
The gelation time (according to JIS C-2104) was 540 seconds. A 0.18 mm thick glass cloth (WE-18K-104-BZ-2 manufactured by Nittobo Co., Ltd.) was impregnated with this varnish and air-dried overnight at room temperature. Furthermore, in a hot air circulation dryer
A prepreg was prepared by processing at 150°C for 5 minutes.
Copper foil (electrolytic copper foil made by Furukawa Electric Co., Ltd., thickness: 35 μm) was layered on both sides of these 9 prepreg sheets, and press molded at 170°C and 25 kg/cm ² for 20 minutes, resulting in a thickness of 1.6 mm and a resin content of 41.0%. A double-sided copper-clad laminate was obtained. From the obtained double-sided copper-clad laminate, JIS C-6481
After cutting out the specified test piece and removing the foil on the surface by etching, a heat deterioration test was conducted in a constant temperature bath at 200°C. After a predetermined time, the sample was allowed to cool to room temperature in a desiccator, and then the bending strength was measured at room temperature. Similarly, a test piece cut to a specified size is
A heating deterioration test was conducted in a constant temperature bath at 200°C, and after a predetermined period of time, it was allowed to cool to room temperature in a desiccator, and the peel strength of the copper foil was measured at room temperature. The above results are shown in Table 1 together with other physical properties. Example 2 75 parts of brominated epoxy resin “YDB-400”,
25 parts of “Epicote #828”, 115 parts of resin-A, 1 part of diaminodiphenylmethane, and methyl ethyl ketone.
The mixture was added to 190 parts and uniformly dissolved while stirring at room temperature. The gelation time of this varnish at 150°C was 525 seconds. A glass cloth was impregnated with this varnish, air-dried overnight at room temperature, and then treated in a hot air circulation dryer at 150° C. for 5 minutes to prepare a prepreg. Thereafter, in the same manner as in Example 1, a double-sided copper-clad laminate having a thickness of 1.6 mm and a resin content of 40.8% was obtained. Table 1 shows the performance of this double-sided copper-clad laminate. Example 3 67 parts of brominated epoxy resin "YDB-400", 33 parts of epoxy resin "Epicote #828", 92 parts of resin B prepared in Reference Example 2, and 3 parts of diaminodiphenylsulfone were added to 170 parts of methyl ethyl ketone, and the mixture was stirred at room temperature. It was dissolved uniformly. of this varnish
The gelation time at 150°C was 680 seconds. A glass cloth was impregnated with this varnish, air-dried overnight at room temperature, and then treated in a hot air circulation dryer at 150°C for 5.5 minutes to produce a prepreg. Thereafter, in the same manner as in Example 1, a double-sided copper-clad laminate having a thickness of 1.6 mm and a resin content of 40.5% was obtained. Table 1 shows the performance of this double-sided copper-clad laminate. Example 4 74 parts of brominated epoxy resin “YDB-400”, 26 parts of epoxy resin “Epicoat #828”, resin-
113 parts of B and 1 part of diaminodiphenylsulfone were added to 190 parts of methyl ethyl ketone and uniformly dissolved with stirring at room temperature. The gelation time of this varnish at 150°C was 575 seconds. A glass cloth was impregnated with this varnish, air-dried overnight at room temperature, and then treated in a hot air circulation dryer at 150° C. for 5 minutes to prepare a prepreg. Thereafter, in the same manner as in Example 1, a double-sided copper-clad laminate having a thickness of 1.6 mm and a resin content of 40.0% was obtained. Table 1 shows the performance of this double-sided copper-clad laminate. Comparative Example 1 The thickness was changed in the same manner as in Example 1 except that diaminodiphenylmethane was not used in Example 1.
A double-sided laminate with a diameter of 1.6 mm and a resin content of 40.9% was obtained. Table 1 shows the performance of this double-sided copper-clad laminate. Comparative Example 2 Brominated epoxy resin “YDB-400” 82 parts, epoxy resin “Epicoat #828” 18 parts Resin-A135
10 parts of diaminodiphenylmethane were added to 210 parts of methyl ethyl ketone and uniformly dissolved with stirring at room temperature. The gelation time of this varnish at 150°C was 360 seconds. A glass cloth was impregnated with this varnish, air-dried overnight at room temperature, and then treated in a hot air circulation dryer at 150° C. for 4 minutes to prepare a prepreg. Thereafter, in the same manner as in Example 1, a double-sided copper-clad laminate having a thickness of 1.6 mm and a resin content of 40.7% was obtained. Table 1 shows the performance of this double-sided copper-clad laminate. Comparative Example 3 A double-sided copper-clad laminate having a thickness of 1.6 mm and a resin content of 41.1% was obtained in the same manner as in Example 3, except that diaminodiphenylsulfone was not used in Example 3. Table 1 shows the performance of this double-sided copper-clad laminate. Comparative example 4 (Flame retardant glass epoxy copper clad laminate NEMA
Production example equivalent to standard FR-4) Brominated epoxy resin "Epicoto #1045-
B80” (trademark, manufactured by Yuka Ciel Co., Ltd., brome content 19.0
%, epoxy equivalent 475g/eq, solid content 80wt%)
125 parts of dicyandiamide, 4 parts of benzyldimethylamine as a curing accelerator, and 0.2 parts of benzyldimethylamine as a curing accelerator were added to a mixed solvent of 34 parts of methyl ethyl ketone, 15 parts of dimethyl formamide, and 15 parts of methyl cellosolve, and the mixture was uniformly dissolved with stirring at room temperature. The gelation time of this varnish at 150°C was 465 seconds. A glass cloth was impregnated with this varnish, air-dried overnight at room temperature, and then treated in a hot air circulation dryer at 150°C for 4.5 minutes to prepare a prepreg. Thereafter, in the same manner as in Example 1, a double-sided copper-clad laminate having a thickness of 1.6 mm and a resin content of 39.6% was obtained. Table 1 shows the performance of this double-sided copper-clad laminate.

【table】

[Table] As shown in Table 1, the composition of the present invention provides an epoxy resin composition that is flame retardant and has excellent heat resistance, particularly excellent heat resistance in terms of copper foil adhesive strength.

Claims (1)

[Claims] 1 To 100 parts by weight of a halogenated epoxy resin or a mixture of a halogenated epoxy resin and an epoxy resin,
50-150 parts by weight of a copolymer containing 20-80% by weight of isopropenylphenol and 20-40% by weight of acrylonitrile as curing agent and 0.1 part by weight of aromatic diamine
A flame-retardant epoxy resin composition characterized in that it contains 5 parts by weight.