JPS6360788B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a thermosetting resin composition obtained by mixing or co-condensing a melamine resin produced from a self-polymerizable alcohol, melamines and formaldehydes, and a phenolic resin and/or an epoxy resin. . Melamine resin has excellent heat resistance, flame resistance, arc resistance, etc., and is widely used for various molded products, laminated products, paints, fiber processing, etc. Melamine resin is especially noteworthy for its flame retardance, and it is cheap and recent. It is attracting attention as a flame retardant filler with low toxicity. However, low condensation melamine resins, which generally have good impregnating properties, have poor storage stability and poor compatibility with various resins and organic solvents, so their use is limited. Therefore, in order to improve the stability of melamine resin and its compatibility with organic solvents, a method of etherification with butanol, methanol, etc. has been conventionally used. However, the effect of imparting flame retardance to melamine resins stabilized in this way is insufficient because the alkyl ether group remains in the resin composition even after curing, and when further heat-treated, gas generation due to dealcoholization reaction occurs. There are problems such as swelling, especially the latter problem,
In applications such as printed wiring board laminates that require high flame retardancy, this method leads to a significant decrease in soldering heat resistance, and as a result, this method does not provide a satisfactory effect. The inventors of the present invention conducted extensive research in light of these circumstances, and found that when producing melamine resin, if the reaction is carried out in the presence of an alcohol that has self-polymerizability, the stability of melamine resin and its compatibility with organic solvents will be improved. Furthermore, these resin compositions not only have excellent flame retardancy and heat retardancy, but also have excellent electrical properties, mechanical properties, soldering heat resistance, etc. The inventors have also discovered that a good laminate can also be obtained, leading to the completion of the present invention. That is, the present invention relates to a thermosetting resin composition comprising a melamine resin (A), a phenolic resin and/or an epoxy resin (B) produced from self-polymerizable alcohols, melamines and formaldehydes, and particularly The present invention relates to a thermosetting resin composition characterized in that the self-polymerizable alcohol is furfuryl alcohol or a (meth)acrylic ester having a hydroxyl group. The present invention is characterized by mixing or co-condensing a melamine resin produced using self-polymerizable alcohols, melamines, and formaldehydes with a phenolic resin and/or an epoxy resin, and the melamine resin is self-polymerized. By using polymerizable alcohols, conventional butyl etherified melamine resin,
Unlike when using methyl etherified melamine resin, the alcohol self-polymerizes and turns into a resin when the resin composition is molded into a laminate or heat treated, so problems such as blistering due to gas generation are completely eliminated. This can be solved by In the present invention, the self-polymerizable alcohols refer to alcohols that react with each other to form oligomers or polymers, such as β-
Acrylic esters with hydroxyl groups such as hydroxyethyl acrylate, β-hydroxyethyl methacrylate, β-hydroxypropyl acrylate, and trimethylolethane diacrylate, or those with radical polymerizability such as allyl alcohol, and under acidic conditions such as furfuryl alcohol. Among these, furfuryl alcohol is preferable from the viewpoint of flame retardancy of the resin composition, and from the viewpoint of flexibility and electrical performance. From this point of view, acrylic esters having a hydroxyl group are preferred. Also, two or more of these may be used in combination. Melamines in the present invention include melamine and guanamines such as benzoguanamine, acetoguanamine, and vinylguanamine, and melamine with a high nitrogen content is preferred from the viewpoint of flame retardant effect. Examples of formaldehydes include formalin, paraformaldehyde, trioxane, hexamethylenetetramine, and the like. The melamine resin of the present invention is produced using the melamine, formaldehyde, and the self-polymerizable alcohol, but the blending ratio of the raw materials, the order of blending, etc. are not particularly limited. Moreover, the conditions such as use of various reaction catalysts, reaction temperature, reaction time, etc. can be applied under all usual conditions. To give general conditions, the molar ratio of formaldehyde to melamine is 1.5 or more, preferably 1.5 to 6, and the catalyst is alkali metal, alkaline earth metal hydroxide, carbonate, A basic catalyst such as acetate or amines, or an acid catalyst such as hydrochloric acid, carbonic acid, oxalic acid, formic acid, or phosphoric acid is usually used, but it is not necessary to use a catalyst, and the reaction temperature is usually 60°C. The above is done. The amount of self-polymerizable alcohols is suitably 0.3 mol or more, preferably 0.3 to 6 mol, per 1 mol of melamine in terms of compatibility with organic solvents and stability. Appropriate timing of addition is at the beginning of the reaction between melamines and formaldehyde, or during the reaction, and then adding it during the reaction to further advance the reaction. Preferably, melamines and formaldehydes are added and the temperature is raised, or the self-polymerizable alcohol is allowed to react after the temperature is raised. Further, after adding the self-polymerizable alcohol, it is preferable to react at a pH of 1 to 6 or 8 to 14, and particularly desirable conditions are a pH of 2 to 4 or 9 to 12. If necessary, alcohols such as methanol and ethanol, glycols such as diethylene glycol and polyethylene glycol, urea, thiourea, and dicyandiamide may be added before, during or after the reaction. The phenolic resin used in the present invention generally refers to those produced by addition condensation of phenols and formaldehyde, and also those modified with tung oil, aromatic hydrocarbons, polybutadiene, polyether, polyurethane, polyester, etc. Also included.
Here, phenols include, for example, phenol, cresol, nonylphenol, octylphenol, halogenated phenol, bisphenol A,
It is a general term for monovalent or polyvalent phenols such as bisphenol F, halogenated bisphenol A, resorcinol, and catechol. The formaldehydes used here are those mentioned above, and epoxy resin is a general term for compounds having epoxy groups such as polyglycidyl ether, polyglycidyl ester, and polyglycidyl amine. Typical examples include the above-mentioned phenols, novolac type phenolic resins, hydrogenated bisphenol A, polyhydric alcohols such as glycerin, polycarboxylic acids such as phthalic acid, terephthalic acid, trimellitic acid, and adipic acid, and diaminodiphenyl. Some are obtained by reacting methane, para-aminophenol, aniline, etc. with epichlorohydrin. In the present invention, flame retardance is imparted to phenolic resins and/or epoxy resins using melamine resins with improved stability and compatibility. Such melamine resin exhibits an effect in imparting flame retardance even in a small amount due to the triazine ring it structurally contains, and the effect increases proportionately as the amount of melamine resin blended increases. Therefore, the blending amount may be appropriately selected depending on the use, purpose, required performance, etc. For example, in the case of a paper phenol laminate, if the melamine resin of the present invention is blended to account for 5% by weight or more of the melamine structure based on the solid content of the resin composition, it has flame retardancy that passes UL94V-0. A laminate is obtained. However, in modified phenolic resins modified with flammable modifiers such as tung oil, it is necessary to use more melamine resin. When producing a resin composition using a melamine resin and a phenol resin, the two may be mixed or co-condensed. The present invention is characterized by the use of a melamine resin with excellent stability and compatibility, which is produced by the reaction of melamines, formaldehyde, and self-polymerizable alcohols, and is particularly useful when cocondensing with a phenolic resin. The method is not limited. For example, a method in which phenols, melamines, formaldehyde and self-polymerizable alcohols are simultaneously charged to proceed the synthesis and co-condensation of each resin at the same time may be carried out as necessary. When manufacturing a resin composition using epoxy resin and melamine resin, it is common to manufacture the melamine resin in advance and mix it with the epoxy resin. Flame retardancy is imparted according to the proportion. Further, if necessary, a resin composition may be manufactured by using a melamine resin, a phenol resin, and an epoxy resin in combination. The resin composition of the present invention has significantly improved compatibility with organic solvents compared to conventional compositions containing melamine resins, so it can be used by diluting with an organic solvent or replacing the solvent as necessary. It is. Examples of solvents that can be used are:
Alcohols such as methanol, ethanol and isopropyl alcohol, ketones such as acetone and methyl ethyl ketone, aromatic hydrocarbons such as toluene and xylene, amides such as dimethylformamide, dimethylacetamide and N-methylpyrrolidone, and esters such as ethyl acetate. , and mixed solvents thereof. The resin composition of the present invention is easily cured by heat treatment, etc., but in order to accelerate curing, curing agents such as amines, acids, carboxylic acid anhydrides, polymerization initiators such as peroxides, reactive diluents, etc. If necessary, a polymerization inhibitor or the like may be added during or after the resin composition production process. The resin composition of the present invention can be applied to a wide range of applications including laminates, molding materials, and adhesives.
Particularly when applied to electrically insulating laminates, it is possible to obtain laminates with excellent flame retardancy, solder heat resistance, electrical insulation, chemical resistance, etc. as a resin varnish with good stability. The resin composition of the present invention itself has excellent flame retardancy, but in order to further improve the effect, it may be used in combination with other flame retardants such as halogen compounds, phosphorus compounds, and antimony compounds, as necessary. Examples will be shown below, in which parts and percentages are based on weight. Example 1 Add 126 parts of melamine and 243 parts of 37% formalin,
The pH was adjusted to 11 with barium hydroxide. After raising the temperature to 70°C, add 260 parts of β-hydroxyethyl acrylate, react at 90°C for 2 hours, and further react at 60°C for 6 hours while dehydrating under reduced pressure. Carbon dioxide gas is blown into the pH.
7.5 and filtered to remove alkali ions to obtain a highly viscous resin M-1. M-1 is soluble in methanol, methyl ethyl ketone, toluene, and mixed solvents thereof, and the resin liquid diluted with these solvents to a non-volatile content of 50% did not change even after being left at room temperature for two months. On the other hand, 460 parts of phenol, 460 parts of 37% formalin, and 18.4 parts of 25% aqueous ammonia were mixed and reacted at 80°C for 3 hours. After that, melamine resin M-
1100 parts, epoxy resin (Dainippon Ink & Chemicals Co., Ltd.)
After adding 30 parts of Epicron 850) and dehydrating under reduced pressure,
A homogeneous resin varnish was prepared by diluting with 750 parts of methyl ethyl ketone. Kraft paper with a thickness of 10 mils was impregnated with this varnish to form a resin-impregnated laminated base material with a resin adhesion content of 50%. Next, a predetermined number of sheets of this impregnated laminated base material are stacked together.
A laminate plate with a thickness of 1.6 mm was produced by heat-pressing the lamination under the lamination conditions of 150° C., 80 kg/cm ² , and 1 hour. Example 2 126 parts of melamine, 180 parts of 37% formalin, and 171 parts of furfuryl alcohol were added, and the pH was adjusted to 9.5 with triethylamine. After raising the temperature to 95°C, the mixture was reacted at 95°C for 6 hours while dehydrating at normal pressure. During this time, PH
Triethylamine was added at appropriate times to maintain the temperature between 9.5 and 10.0. Further, water was removed under reduced pressure to obtain melamine resin M-2 with high viscosity. This M-2 is soluble in methanol, toluene, methyl ethyl ketone, toluene, and mixed solvents thereof, and a resin liquid with a nonvolatile content of 50% diluted with these solvents did not change even after being left at room temperature for two months. On the other hand, a mixture consisting of 540 parts of metacresol, 300 parts of tung oil, 240 parts of nonylphenol and 6 parts of phosphoric acid was reacted at 120°C for 3 hours. After this was cooled to 90°C, 650 parts of 37% formalin and 10 parts of aqueous ammonia were added, and the mixture was further reacted at 95°C for 5 hours. After dehydration under reduced pressure, a solution of 2,300 parts of melamine resin M-2 dissolved in 1,300 parts of a mixed solvent of methanol and toluene was added to obtain a uniform resin varnish. Next, using this modified phenolic resin varnish, the same operation as in Example 1 was repeated to prepare a laminate plate with a thickness of 1.6 mm. Example 3 Add 126 parts of melamine, 300 parts of 37% formalin, 40 parts of phenol, and 280 parts of furfuryl alcohol, adjust the pH to 3 using phosphoric acid, raise the temperature to 80°C, and react at 80°C for 9 hours while dehydrating under reduced pressure. and high viscosity melamine resin M-3 was synthesized. This melamine resin is soluble in methanol, methyl ethyl ketone, toluene, and mixed solvents thereof, and a resin liquid with a nonvolatile content of 50% diluted with these solvents did not change even after being left at room temperature for two months. On the other hand, a mixture consisting of 470 parts of phenol, 200 parts of tung oil, 450 parts of butylphenol, and 5 parts of phosphoric acid was reacted at 120°C for 3 hours, and then cooled to 90°C.
Add 830 parts of 37% formalin and 10 parts of ammonia water,
The reaction was further carried out at 90°C. Next, the mixture was dehydrated under reduced pressure, and 1,400 parts of a mixed solvent of methanol and toluene were added to synthesize tung oil-modified phenolic resin P-1. To 100 parts of this tung oil modified phenolic resin P-1,
15 parts of melamine resin M-3 were mixed to produce a uniform modified phenolic resin varnish. Next, using this modified phenolic resin varnish, the same operation as in Example 1 was repeated to prepare a 1.6 mm thick laminate. Example 4 450 parts of epoxy resin (Epicron 1051, manufactured by Dainippon Ink and Chemicals Co., Ltd.), 170 parts of novolac type phenolic resin (Barcam TD2123-60M, manufactured by Dainippon Ink and Chemicals Co., Ltd.), and melamine resin M-1 of Example 1 A uniform epoxy resin varnish was produced by dissolving and mixing 160 parts with 640 parts of methyl ethyl ketone. A glass cloth base material was impregnated with this epoxy resin varnish to obtain a resin-impregnated laminated base material with a resin adhesion content of 50%.
Next, a predetermined number of sheets of this impregnated laminated base material are stacked together.
A laminate plate with a thickness of 1.6 mm was produced by heating and pressing under lamination conditions of 150°C, 40 kg/cm ² and 1 hour. Example 5 100 parts of epoxy resin (Epicron 1051 manufactured by Dainippon Ink and Chemicals Co., Ltd.), 4 parts of dicyandiamide, and 30 parts of melamine resin M-2 of Example 2 were dissolved and mixed in 130 parts of methyl ethyl ketone to produce a uniform epoxy resin varnish. Manufactured. Next, using this epoxy resin varnish, the same operations as in Example 4 were repeated to create a 1.6 mm thick laminate. Example 6 180 parts of epoxy resin (Epicron 850 manufactured by Dainippon Ink and Chemicals Co., Ltd.), 120 parts of polyvinylphenol (Resin M manufactured by Maruzen Oil Co., Ltd.) and Example 3
A uniform epoxy resin varnish was prepared by dissolving and mixing 30 parts of melamine resin M-3 with 330 parts of methyl ethyl ketone. Next, using this epoxy resin varnish, the same operation as in Example 4 was repeated to create a laminate plate with a thickness of 1.6 mm. Comparative Example 1 Add 126 parts of melamine and 180 parts of 37% formalin, adjust the pH to 10.5 with triethylamine, raise the temperature to 95°C, add triethylamine as needed, and react at 95°C for 8 hours while maintaining the pH between 10 and 11. A uniform melamine resin aqueous solution M-4 was produced. This melamine resin M-4 precipitated after 6 days at room temperature, and even when methanol, methyl ethyl ketone, toluene, and a mixed solvent thereof were added to the resin liquid or its dehydrate, a homogeneous solution could not be obtained.After dehydration and concentration, methyl ethyl ketone, Attempts were made to add methanol and mix with epoxy resin, but the resultant resin solution was not uniform and had poor impregnation into glass and paper base materials, so we had no choice but to abandon the idea of making a laminate. Comparative Example 2 126 parts of melamine, 243 parts of 37% formalin, and 200 parts of methanol were added, the pH was adjusted to 3 with phosphoric acid, and the mixture was heated to reflux temperature and refluxed for 10 hours to obtain a uniform melamine resin liquid M-5. Manufactured. Thirty parts of this melamine resin liquid M-5 was mixed with 100 parts of tung oil modified phenolic resin P-1 of Example 3 to produce a uniform modified phenolic resin varnish. Next, the same operation as in Example 1 was repeated except for using this modified phenolic resin varnish to determine the thickness.
A 1.6mm laminate was made. Comparative Example 3 60 parts of the melamine resin of Comparative Example 2 and epoxy resin (Epicron, a product of Dainippon Ink and Chemicals Co., Ltd.)
1050) and 4 parts of dicyandiamide were mixed and dissolved in 160 parts of methyl ethyl ketone to prepare an epoxy resin varnish. A laminate plate having a thickness of 1.6 mm was produced by repeating the same operations as in Example 4 except for using this varnish. Table 1 below shows the properties of the paper-based phenolic resin laminate, and Table 2 shows the properties of the glass cloth-based epoxy resin laminate.

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Claims (1)

[Scope of Claims] 1. A thermosetting resin composition comprising a melamine resin (A), a phenolic resin and/or an epoxy resin (B) produced from self-polymerizable alcohols, melamines and formaldehydes. 2. The thermosetting resin composition according to claim 1, wherein the self-polymerizable alcohol is furfuryl alcohol or a (meth)acrylic ester having a hydroxyl group.