JPS6337813B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a curable resin composition that can be used in a wide range of applications such as molding materials, laminated materials, paints, and adhesives. More specifically, the present invention relates to a thermosetting resin composition that has good curability, excellent workability during molding, and provides a cured product with excellent heat resistance, adhesiveness, and dimensional stability. 2. Description of the Related Art Thermosetting resin compositions made by blending an epoxy resin with a compound having a phenolic hydroxyl group are conventionally known. For example, thermosetting resin compositions made by blending novolak type phenolic resins with epoxy resins are used in fields such as molding materials, laminated materials, and paints. However, the dimensional stability of the cured product is poor and it cannot be used for electronic industrial materials that require dimensional accuracy. In addition, heat resistance,
In particular, the heat deformation temperature is low at around 100℃, and electrical parts,
It has been difficult to use them as so-called engineering plastics for industrial equipment such as mechanical parts, automobiles, aircraft, and vehicles. However, in recent years, thermosetting resin compositions containing paraisopropenylphenol polymers, paravinylphenol polymers, and epoxy resins have been developed. Although the cured product made from this composition is superior in heat resistance and dimensional stability compared to the cured product made by blending conventional epoxy resin and novolak type phenolic resin, it has the following drawbacks. There were restrictions in terms of usage. In other words, the adhesion is poor and, for example, when used on copper-clad laminates based on glass cloth, the adhesive strength is insufficient, resulting in delamination between the glass cloth and further damage between the copper foil and the laminate. However, it had the disadvantage of requiring a separate adhesive. Furthermore, in terms of heat resistance, when used at temperatures below 200°C, the strength retention rate of various physical properties such as mechanical strength is sufficient, but at high temperatures above 300°C, the cured product undergoes thermal decomposition, resulting in a decrease in physical properties. There is a drawback that it cannot be used in applications where it is used under harsh conditions. In addition, when a compound having a phenolic hydroxyl group such as the above-mentioned novolak type phenol resin, paraisopropenylphenol polymer, and paravinylphenol polymer is blended with an epoxy resin and cured, a tertiary amine or the like is usually used to accelerate the curing. A method is being used to shorten the curing time using a curing agent. In this case, although curing is faster, some of the amine volatilizes during compounding or molding operations, resulting in a bad odor and furthermore, there are operational problems such as skin irritation when the volatilized amine vapor comes into contact with it. Furthermore, the obtained cured product also has a problem in terms of physical properties, such as poor adhesion. As a result of intensive studies to solve the above-mentioned drawbacks, the present inventors have developed a copolymer (hereinafter referred to as "A copolymer") containing a polymerizable monomer having a basic group and an alkenylphenol as essential components in an epoxy resin. A thermosetting resin composition containing the compound (abbreviated as "Kogo") has good curability, has excellent workability during molding, and provides a cured product with excellent heat resistance, adhesiveness, and dimensional stability. This discovery led to the completion of the present invention. By using the thermosetting resin composition of the present invention, a molded product with excellent heat resistance and high dimensional accuracy can be obtained, and the molded product also has high rigidity when heated and can be easily removed from the mold after molding. As a result, molding efficiency can be further improved. When used in laminated materials, the adhesive strength is high, and in the case of copper-clad laminates, the interlayer peeling strength between base materials such as paper and glass is extremely high, and the peeling strength between the copper foil and the laminated material is extremely high. Its copper peeling strength is also extremely high. The thermosetting resin composition of the present invention is also characterized in that, without using a curing accelerator such as a tertiary amine, a sufficient curing rate equivalent to or higher than that obtained using a curing accelerator can be obtained. Therefore, it fully satisfies the requirement for curing at low temperatures and in a short time, and has excellent workability, with no odor or skin damage caused by amine volatilization. In addition, since the obtained cured product has high adhesive strength, it can be expected to have a wide range of applications when used in paints and adhesives. Furthermore, the thermosetting resin composition of the present invention is characterized by being able to obtain a cured product having a wide range of heat distortion temperatures by changing the content of the alkenylphenol component in the A copolymer, and also being flexible. The advantage is that it can be manufactured as desired, from those with high density to those with high rigidity. Moreover, they have an excellent heat resistance, especially the thermal decomposition initiation temperature, which shows a high value of around 350° C. or higher regardless of the amount of alkenylphenol component. Examples of the polymerizable monomer having a basic group in copolymer A used in the present invention include N,N-dimethylaminoethyl acrylate, N-acrylate,
N-dimethylaminopropyl, acrylic acid N,N
-Acrylic acid N,N such as diethylaminoethyl
-Dialkylaminoalkyl esters, N,N-dialkylaminoalkyl esters of methacrylate such as N,N-dimethylaminoethyl methacrylate, N,N-diethylaminoethyl methacrylate, N,N-dimethylaminopropyl methacrylate, vinyl Aniline, isopropenylaniline, N-vinyldimethylamine, N-vinyldiethylamine, N-vinyldiphenylamine, N-
Vinylpyrrole, N-vinylindole, N-vinylcarbazole, N-vinylimidazole, N
-vinylpyrrolidone, 2-methyl N-vinylimidazole, 2-vinylquinoline, 3-vinylpiperidine, N-methyl-3-vinylpiperidine, vinylpyrazine, 2-vinylpyridine, 3-vinylpyridine, 4-vinylpyridine, 2 -methyl-5
-vinylpyridine, 5-ethyl-2-vinylpyridine, N-(2-dimethylaminomethyl)acrylamide, N-(2-dimethylaminoethyl)acrylamide, N-(3-dimethylaminopropyl)acrylamide, N-(2-dimethylaminoethyl)acrylamide, N-(2-dimethylaminopropyl)acrylamide, -diethylaminoethyl)acrylamide, N-(2-morpholinoethyl)acrylamide, N-(2-dimethylaminomethyl)methacrylamide, N-(2-
diethylaminoethyl)methacrylamide, N
-(2-dibutylaminomethyl)methacrylamide and the like, and one or more of these can be used. The alkenylphenols in copolymer A include vinylphenol, isopropenylphenol, n-butenylphenol, 2- or 3-butenylphenol, etc., including ortho-, meta-, para-, or mixtures thereof. It can be either. The content of the polymerizable monomer having a basic group and the alkenylphenol in the copolymer A of the present invention is preferably within the following range. That is, for polymerizable monomers having basic groups, 0.01 parts by weight or more in 100 parts by weight of A copolymer.
Less than 20 parts by weight, preferably 0.05 parts by weight or more and less than 10 parts by weight. If the amount of the polymerizable monomer having a basic group is less than 0.01 parts by weight, curability will be poor, and if it is more than 20 parts by weight, sufficient performance in heat resistance, adhesiveness, and dimensional stability will not be obtained. do not have. In addition, the content of alkenylphenol in copolymer A is 5 parts by weight or more based on 100 parts by weight of copolymer A.
It is preferably less than 90 parts by weight, preferably 10 parts by weight or more and less than 80 parts by weight. If the alkenylphenol content is less than 5 parts by weight, heat resistance and dimensional stability will decrease,
If the amount exceeds 90 parts by weight, the adhesiveness will decrease. Next, if the polymerizable monomer having a basic group in copolymer A, alkenylphenol, is within the above range, a known polymerizable monomer such as styrene, chlorstyrene, bromstyrene, α-methyl Styrene, vinyl toluene, vinyl xylene and other styrenes, methyl acrylate, ethyl acrylate,
Acrylic acid esters such as n-butyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, n-methacrylate
Methacrylic acid esters such as butyl, acrylonitrile, methacrylonitrile, fumaronitrile,
Acrylic acid, methacrylic acid, maleic anhydride, acrylamide, methacrylamide, isoprene,
One or more types of butadiene etc. may be used in combination. The molecular weight of copolymer A is preferably 300 or more and less than 200,000, preferably 500 or more and less than 50,000. If it is less than 300 or more than 200,000, a thermosetting resin composition with excellent curability, heat resistance, adhesiveness, and dimensional stability, which is the object of the present invention, cannot be obtained. Moreover, any epoxy resin used in the present invention can be used as long as it has at least two or more epoxy groups in one molecule. For example, bisphenol type A, halogenated bisphenol type, resorcin type, bisphenol type F, tetrahydroxyphenylmethane type, novolak type, polyglycol type, glycerin triether type, polyolefin type, epoxidized soybean oil, alicyclic type. There are various epoxy resins such as formulas, and two or more of these may be used in combination. The thermosetting resin composition according to the present invention is constructed by blending the A copolymer with an epoxy resin, but the constituent proportions thereof can be blended in various proportions as necessary. That is, the ratio of the number of phenolic hydroxyl groups in the A copolymer to the number of epoxy groups in the epoxy resin (OH group/epoxy group ratio) is preferably 0.2 or more and less than 5, preferably 0.5 or more and less than 2. When the OH group/epoxy group ratio is less than 0.2 and 5 or more, the characteristics of the present invention such as heat resistance, adhesiveness,
Dimensional stability cannot be achieved. The thermosetting resin composition according to the present invention can be used as follows. In other words, the epoxy resin and the A copolymer are mixed and then pulverized, or after mixing,
It can also be used by heating at 80-170°C for several minutes to partially cure it and then crushing it. Furthermore, common solvents for the epoxy resin and copolymer A, such as alcohols such as methanol, ethanol, propanol, benzyl alcohol, and diacetone alcohol, ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone, dioxane, and tetrahydrofuran are also used. , ethers such as methyl cellosolve, ethyl cellosolve,
Esters such as ethyl acetate and butyl acetate, dimethylformamide, dimethylacetamide, N-
It can also be used in the form of a varnish using one or more solvents such as nitrogen-containing solvents such as methyl-2-pyrrolidone, hydrocarbons such as benzene, toluene, and xylene, and dimethyl sulfoxide. It can also be used as a powder to be crushed after removing the solvent from the varnish. Next, examples of uses 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 made into a molded body by compression molding, transfer molding, or injection molding at a temperature of 80 to 250°C. In this case, 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 a varnish prepared by dissolving the composition of the present invention in a solvent, and then the solvent is removed to form a prepreg, which is made into several sheets or more.
Stack several dozen sheets at a temperature of 100 to 200℃, 20 to 100 kg/
With a pressure of cm ² it is possible to obtain a laminate. The laminate may be further post-cured at 150-250° C. for several hours if necessary. When used as a paint, the varnish of the composition of the present invention is applied to a support and heated and dried at 100 to 200°C, or the mixed pulverized product or partially cured powder product is coated with an electrostatic coating machine. For example, it can be applied onto a steel plate and baked at 100 to 200°C to obtain a coating film with a uniform thickness. In addition, for use as an adhesive, reactive diluents such as phenyl glycidyl ether, fillers such as silica, asbestos, etc. may be added to the composition of the present invention as necessary.
After being applied to an adherend, it can be cured and bonded by applying the adhesive to the adherend and heating it to 80 to 200°C. Hereinafter, the effects of the present invention will be specifically explained using production examples, examples, and measurement results of various physical properties. Production example 1 2-vinylpyridine 1g, paraisopropenylphenol 50g, methyl methacrylate 30g, acrylonitrile 20g, methyl ethyl ketone 200g,
and 3.6 g of azobisisobutyronitrile were placed in a flask and polymerized at reflux temperature for 10 hours.
A copolymer solution with a solid content concentration of 31% by weight was obtained. After vacuum drying this solution at a temperature of 170°C for 4 hours,
It was ground to obtain 93 g of copolymer powder (1). The content of 2-vinylpyridine in this copolymer was determined to be 0.8% by weight by non-aqueous titration using a perchloric acid standard solution in dioxane solvent. In addition, gel permeation chromatography (hereinafter referred to as
Weight average molecular weight according to GPC (abbreviated as GPC) is 10000
It was hot. Production example 2 N-(2-diethylaminoethyl)acrylamide 3g, paraisopropenylphenol 50g,
Methyl methacrylate 30g, acrylonitrile 20g
g, 200 g of methyl ethyl ketone and 3.6 g of azobisisobutyronitrile were placed in a flask,
Polymerization was carried out at reflux temperature for 10 hours to obtain a copolymer solution with a solid content concentration of 31% by weight. This solution was vacuum dried at a temperature of 170°C for 4 hours, and then ground to form a copolymer powder.
(2) 92g was obtained. The N-(2-diethylaminoethyl)acrylamide content in this copolymer was measured in the same manner as in Production Example 1 and was found to be 2.6% by weight.
In addition, the weight average molecular weight of the copolymer by GPC is
It was 10,000. Production example 3 N,N-diethylaminoethyl acrylate 1.5
g, 70 g of paraisopropenylphenol, 30 g of acrylonitrile, 200 g of methyl ethyl ketone, and 4 g of azobisisobutyronitrile were charged into a flask and polymerized at reflux temperature for 10 hours to obtain a copolymer solution with a solid content concentration of 32% by weight. This solution
After vacuum drying at a temperature of 170° C. for 4 hours, the mixture was pulverized to obtain 97 g of copolymer powder (3). The diethylaminoethyl acrylate content in this copolymer was determined in Production Example 1.
When measured in the same manner as above, it was 1.4% by weight. Also,
The weight average molecular weight of the copolymer by GPC was 8,000. Production example 4 N,N-dimethylaminoethyl methacrylate
0.5 g, paraisopropenylphenol 30 g, acrylonitrile 30 g, styrene 40 g, methyl ethyl ketone 200 g and azobisisobutyronitrile 4.6 g were charged into a flask and polymerized at reflux temperature for 10 hours to produce a copolymer with a solid content concentration of 33% by weight. A solution was obtained. This solution was vacuum dried at a temperature of 170° C. for 4 hours and then ground to obtain 98 g of copolymer powder (4). The content of dimethylaminoethyl methacrylate in this copolymer was measured in the same manner as in Production Example 1.
It was 0.5% by weight. Furthermore, the weight average molecular weight of the copolymer by GPC was 5,000. Production example 5 3-vinylpiperidine 1g, paraisopropenylphenol 20g, α-methylstyrene 50g, acrylonitrile 30g, methyl ethyl ketone 200g
and 4.6 g of azobisisobutyronitrile were charged into a flask and polymerized at reflux temperature for 10 hours to obtain a copolymer solution with a solid content concentration of 32% by weight. This solution was vacuum dried at a temperature of 170° C. for 4 hours and then ground to obtain 95 g of copolymer powder (5). The 3-vinylpiperidine content in this copolymer was measured in the same manner as in Production Example 1, and was found to be 0.8% by weight. Also,
The weight average molecular weight of the copolymer by GPC was 6000. Production example 6 Paraisopropenylaniline 1g, paraisopropenylphenol 50g, methyl acrylate 50g
g, 200 g of methyl ethyl ketone and 4.6 g of azobisisobutyronitrile were charged into a flask and polymerized at reflux temperature for 10 hours to obtain a copolymer solution with a solid content concentration of 29%. After vacuum drying this solution at a temperature of 170°C for 4 hours, it was pulverized to form a copolymer powder (6).
Obtained 90g. The content of paraisopropenylaniline in this copolymer was measured in the same manner as in Production Example 1, and was found to be 0.9% by weight. Furthermore, the weight average molecular weight of the copolymer by GPC was 4,500. Other polymerizable monomers having basic groups and alkenylphenols used in the present invention can also be used in the same manner as in Production Examples 1 to 6. Example 1 59 g of copolymer powder (1) obtained in Production Example 1 and bisphenol A type epoxy resin (Epicoat 828 manufactured by Ciel Chemical Co., Ltd., epoxy equivalent 190, hereinafter referred to as "Epicoat")
828'') was dissolved in 100 g of acetone to form a homogeneous solution. This solution was vacuum-dried at room temperature for 24 hours to remove most of the acetone, and 101 g of a thermosetting resin composition was obtained. Example 2 59 g of the copolymer powder (2) obtained in Production Example 2 and 41 g of Epicoat 828 were dissolved in 100 g of acetone to form a uniform solution. This solution was vacuum-dried at room temperature for 24 hours to remove most of the acetone, and 100 g of a thermosetting resin composition was obtained. Example 3 59 g of the copolymer powder (3) obtained in Production Example 3 and 50 g of Epicote 828 were dissolved in 100 g of acetone to form a uniform solution. This solution was vacuum-dried at room temperature for 24 hours to remove most of the acetone, and 100 g of a thermosetting resin composition was obtained. Example 4 70 g of the copolymer powder (4) obtained in Production Example 4 and 30 g of Epicoat 828 were melt-mixed at a temperature of 60°C. This is pulverized using a crusher to form a thermosetting resin composition powder of 96%.
I got g. Example 5 78 g of the copolymer powder (5) obtained in Production Example 5 and 22 g of Epicote 828 were dissolved in 100 g of acetone to form a uniform solution. This solution was vacuum-dried at room temperature for 24 hours to remove most of the acetone, and 101 g of a thermosetting resin composition was obtained. Example 6 59 g of the copolymer powder (6) obtained in Production Example 6 and 41 g of Epicoat 828 were dissolved in 100 g of acetone to form a uniform solution. This solution was vacuum dried at room temperature for 24 hours,
After removing most of the acetone, 102 g of a thermosetting resin composition was obtained. The above-mentioned epoxy resins other than Epicoat 828 used in the present invention can also be used in the same manner as in Examples 1 to 6. Comparative Example 1 35 g of general-purpose novolac type phenolic resin (Novolac 2000 manufactured by Mitsui Toatsu Chemical Co., Ltd.) with a softening point of 92 to 98°C,
65g of Epicoat 828 and N as a curing accelerator.
0.7 g of N-dimethylbenzylamine to 100 g of acetone
g to make a homogeneous solution. This solution was vacuum dried at room temperature for 24 hours to remove most of the acetone, and 99 g of a thermosetting resin composition was obtained. Comparative Example 2 59 g of paraisopropenylphenol polymer having a weight average molecular weight of 10,000, 41 g of Epicoat 828, and 0.5 g of triethanolamine as a hardening accelerator were dissolved in 100 g of acetone to form a uniform solution. After vacuum drying this solution at room temperature for 24 hours to remove most of the acetone, 103g of thermosetting resin composition was obtained.
I got it. Comparative Example 3 59 g of copolymer powder with a weight average molecular weight of 4500 obtained in exactly the same manner as Production Example 6 except that 1 g of paraisopropenylaniline was not added as a polymerizable monomer.
41 g of Epikote 828 and 0.5 g of aniline as a curing accelerator were dissolved in 100 g of acetone to form a uniform solution. This solution was vacuum dried at room temperature for 24 hours to remove most of the acetone, yielding 102 g of a thermosetting resin composition. As mentioned above, the following physical properties were measured for the thermosetting resin compositions of Examples 1 to 6 and Comparative Examples 1 to 3. (A) Gel time According to JIS K6910, each of the above compositions is placed on a hot plate at 150°C, and the time until stringiness disappears. (B) Presence or absence of amine odor Place 10 g of each of the above compositions in a 20 c.c. test tube,
Immerse it in a constant temperature bath at 100℃, and after 30 minutes check for amine odor at the top of the test tube. (C) Soldering heat resistance and copper peeling strength of copper-clad laminates. Preparation of copper-clad laminate 100 g of each of the above compositions was dissolved in 100 g of methyl ethyl ketone to form a uniform solution. Glass cloth (manufactured by Nitto Boseki Co., Ltd.) was added to this solution, i.e., varnish.
WE18K104BZ-2, thickness 0.16mm) was immersed,
Take out the glass cloth impregnated with varnish and 10
Air dried for a minute. This was dried for 5 minutes in a dryer at 140°C to obtain a prepreg. Nine sheets of this prepreg were stacked, the top and bottom sides were sandwiched between 35μ thick copper foils, and pressed at 160℃ and 30Kg/ ^cm2 .
Compression molded for 20 minutes. Next, the temperature was increased to 170° C. and the pressure was increased to 70 Kg/cm ² , and heating and pressurization was further performed for 3 hours to obtain a double-sided copper-clad laminate with a thickness of 1.6 mm. Soldering heat resistance: Based on JIS C6481. Copper peeling strength: Conformed to JIS C6481. (D) Molding shrinkage rate Preparation of molding powder 200g of silica powder for 100g of each of the above compositions,
Add 1g of magnesium stearate to each
The mixture was melt-kneaded for 4 minutes using a heated roll at 100°C. Next, it was ground into 20 meshes or less using a grinder to form a molded powder. Mold Shrinkage Rate Using the molding powder described above, the molding shrinkage rate was determined according to JIS K6911. (E) Thermal decomposition initiation temperature Each of the above compositions was heated and cured in a dryer at 170°C for 5 hours. Next, the thermal decomposition onset temperature (5% weight loss temperature) of this cured product was determined by thermogravimetric analysis (TGA). The results of the above measurements are shown in Table 1. As can be seen from this table, the curable resin composition of the present invention was shown to have good curability, excellent workability, and gave a cured product with excellent heat resistance, adhesiveness, and dimensional stability. 【table】

Claims (1)

[Scope of Claims] 1. In an epoxy resin, 0.05 to 10 parts by weight of a polymerizable monomer having a basic group and 5 to 10 parts by weight of an alkenylphenol.
In a curable resin composition formed by blending a copolymer containing 90 parts by weight as an essential component, (1) the ratio of the number of phenolic hydroxyl groups in the copolymer to the number of epoxy groups in the epoxy resin (OH Base/
(2) the polymerizable monomer having a basic group in the copolymer is an acrylic acid N, N-dialkylaminoalkyl ester, a methacrylic acid N, N-dialkyl A curable resin composition characterized in that it is selected from the group consisting of aminoalkyl esters, alkenylanilines, vinylpyridines, vinylpiperidines, and N-dialkylaminoalkylacrylamides.