JPH0264122A - Thermosetting resin composition - Google Patents

Abstract

PURPOSE:To obtain the title composition useful as adhesive, electrical insulating material, etc., having excellent flexibility, mechanical strength, electrical characteristics, comprising a prepolymer prepared by reacting an epoxy resin with a specific butadiene low polymer derivative under a specific condition and curing agent. CONSTITUTION:The aimed composition comprising a prepolymer obtained by reacting (A) an epoxy resin (one having preferably 200-7,000 molecular weight) with (B) a butadiene low polymer derivative prepared by adding 0.1-1.5 mol, preferably 0.2-1.0 mol maleic anhydride to 10g butadiene low polymer having 300-5,000 number-average molecular weight and further adding 0.5-1.1 equivalent, preferably 0.7-0.9 equivalent (based on succinic anhydride group formed by adding maleic anhydride) in the weight ratio of the component A/B of (95/5)-(40/60) at 0-300 deg.C and (C) a curing agent (e.g., amine-based curing agent).

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a thermosetting resin composition comprising a prepolymer obtained by reacting (A) an epoxy resin and (B) a derivative of a butadiene low polymer, and (C) a curing agent. It is.

In general, epoxy resins have excellent mechanical properties, adhesive properties, and chemical resistance, so they are widely used in paints, blue tints, and electrical insulation materials, but their cured products lack flexibility. However, it has poor impact strength, thermal shock, and peel strength, and has various limitations on its use.

In order to compensate for these drawbacks, a method has been proposed in which a prepolymer obtained by reacting a butadiene low polymer containing a terminal hydroxyl group with an acid anhydride is used as a curing agent for an epoxy resin to improve flexibility (for example, as described in Japanese Patent Application Laid-Open No. Japanese Patent Publication No. 50-3800 discloses a method of improving flexibility by curing a butadiene low polymer containing a terminal carboxyl group and an epoxy resin (for example, Japanese Patent Publication No. 3800/1982). However, in these known methods, butadiene-111 containing carboxyl or hydroxyl groups at both ends
f Since coalescence is used, it has poor compatibility with epoxy resins, making it impossible to obtain truly uniformly cured resins, making it difficult to obtain cured products with satisfactory performance in terms of mechanical strength, chemical resistance, etc. .

The purpose of the present invention is to improve the shortcomings of the above-mentioned known techniques, and to provide excellent flexibility and good mechanical strength by using a modified butadiene low polymer that has excellent compatibility with epoxy resins. and to provide a thermosetting resin composition having electrical properties.

As a result of intensive research, the present inventors have found that a butadiene low polymer derivative obtained by adding a specific amount of maleic anhydride to a butadiene low polymer having a specified molecular weight and further adding a specific amount of amino acids. It has been found that the above object can be achieved by using the present invention, and the present invention has been completed.

That is, the present invention involves adding 0.1 to 1.5 moles of maleic anhydride to (A) an epoxy resin and (B) 100 g of a butadiene low polymer having a number average molecular weight of 300 to 5,000, and then adding 0.1 to 1.5 moles of an amino acid.゜5-1.1 equivalent (based on the succinic anhydride group generated by adding maleic anhydride)
A derivative of butadiene low polymer obtained by addition reaction (A
)/(B) in a weight ratio of 9515 to 40/60 and a prepolymer obtained by reacting at 0 to 300°C and (
C) A thermosetting resin composition comprising a curing agent.

The present invention will be explained in more detail below.

The epoxy resin that is component (A) of the present invention is a conventionally known commercially available product, that is, an epoxy resin with a molecular weight of 200 to 7.
000 compounds. For details on these, please see, for example, Monthly Polymer Processing, Special Issue 9 "Epoxy Resin" (1939
(June 2008). Specifically, bisphenol A type products, such as Epicote 828.100
1. Novolac type such as 1004 and 1007 (manufactured by Shell Chemical ■), such as Epicote 152,
and glycidyl ether type of aliphatic alcohol such as 154 (manufactured by Shell Chemical ■).

For example, alicyclic epoxy resins such as Epon 812 (manufactured by Shell Chemical Co., Ltd.), Chissonox 221 (manufactured by Chisso Chemical Co., Ltd.),
Oligomers with a molecular weight of 200 or more having two or more epoxy groups in one molecule, such as glycidyl methacrylate or copolymers containing glycidyl acrylate, such as epoxidized oils such as epoxidized Soyura and Timer acid Alternatively, polymers and synthetic resins such as polyester, acrylic resin, polyurethane, and polybutadiene may be modified with polyepoxides to introduce epoxy groups into the resin skeleton. Among these, bisphenol A type is particularly preferred. Further, these various epoxy resins can be used alone or as a mixture of two or more.

The derivative of butadiene low polymer, which is component (B) of the present invention, can be obtained by adding a specific amount of maleic anhydride to a butadiene low polymer and then adding a specific amount of amino acid.

The starting material, butadiene low polymer, has a number average molecular weight of 3.
00-5000. Preferably it is a butadiene homopolymer and/or copolymer having a molecular weight of 400 to 3,000. As the copolymer, butadiene vinyl monomer or butadiene-diolefin copolymer can be used, and butadiene-styrenes (styrene, α-methylstyrene, vinyltoluene) or butadiene-isoprene copolymer are particularly preferred. In addition, the butadiene unit in the copolymer is 50
It is preferable that it is at least % by weight. If the number average molecular weight is less than the above range, the cured resin or coating film will not have the required strength, and various properties such as heat resistance, water resistance, and chemical resistance will deteriorate. On the other hand, if it exceeds the above range, gelation tends to occur during the maleic anhydride addition reaction described below, and the compatibility with the epoxy resin also decreases.

There are no particular restrictions on the microstructure of the butadiene low polymer, and both polymers with many vinyl bonds and polymers with many 1,4-bonds can be used.

Conventionally known methods can be used to produce these butadiene low polymers, such as polymerization in a hydrocarbon solvent using lithium, sodium or an organometallic compound thereof as a catalyst, polycyclic aromatic compounds, e.g. an alkali metal in a polar solvent 1, e.g.
For example, a method of polymerization using sodium as a catalyst, a method of using a coordination anion polymerization catalyst, or a method of telomerization using a radical polymerization catalyst is preferable.

To add maleic anhydride to butadiene oligomers,
It is obtained by adding 0.1 to 1.5 mol, preferably 0.2 to 1.0 mol, of maleic anhydride to 100 g of the butadiene low polymer. If the amount of maleic anhydride added is less than this range, the compatibility with the epoxy resin will be insufficient, while if it exceeds this range, gelation will easily occur during the addition reaction, and the cured product will deteriorate. This is not preferable because it also reduces water resistance and chemical resistance. Conventionally known addition reaction conditions can be employed.

That is, the reaction temperature is preferably 100 to 300°C, and the gelation reaction can be prevented by adding a small amount of phenylenediamine, pyrogallol, naphthol, or the like.

The butadiene low polymer derivative (B) can be obtained by reacting the maleic anhydride-added butadiene low polymer with 0.5 to 1.1 equivalents, preferably 0.7 to 0.6 g equivalent, of an amino acid. The equivalent here is based on the succinic anhydride group formed by addition of maleic anhydride. If the amount of amino acids added is less than this range, it will not be possible to provide the cured product with sufficient flexibility, which is a feature of the present invention.On the other hand, if it exceeds this range, unreacted amino acids will remain and the cured product will not have sufficient flexibility. This is not preferable because it reduces water resistance, chemical resistance, etc. The addition reaction is carried out at a temperature of 50 to 300°C, preferably 100 to 200°C, and a method of distilling the produced water out of the reaction system to promote the reaction can also be adopted.

The reaction between a butadiene low polymer to which maleic anhydride has been added and an amino acid as used in the present invention is a reaction in which an imide bond is produced by the reaction between the succinic anhydride group produced by the addition of maleic acid and the amino group of the amino acid.

The reaction can be carried out in the presence or absence of a solvent. Preferred solvents include water and ether solvents such as diethylene glycol dimethyl ether and anisole.

The amino acids used in the present invention are preferably monoaminomonocarboxylic acids (neutral amino acids) and monoaminodicarboxylic acids (acidic amino acids), such as glycine, alanine, valine, leucine, isoleucine, γ-aminocaproic acid, aspartic acid, glutamic acid, etc. can be mentioned.

Epoxy resin (A) and butadiene low polymer derivative (B)
) The blending ratio (A)/(B) is 9515 to 4 in weight ratio
It is preferable to adjust the ratio to 0/60. (B)
If the weight ratio is less than the above range, the flexibility of the cured product will not be improved, while if it exceeds this range, the mechanical strength of the cured product will decrease. This prepolymer of components (A) and (B) can be obtained without side reactions by using, for example, triphenylphosphine, triethylamine, N-N-dimethylbenzylamine, triethylammonium chloride, etc. as a catalyst. The reaction temperature is 0 to 300°C, preferably 50 to 200°C, and a solvent inert to the reaction,
That is, hydrocarbon solvents such as toluene and xylene, and ether solvents such as diethylene glycol dimethyl ether and anisole may be used.

In order to cure the prepolymer that is the composition of the present invention, a curing agent (C) which is usually known as a curing agent for epoxy resins is used.
After blending, the room temperature to 250℃, preferably 50 to 2
A temperature condition of 00°C is used.

Examples of the curing agent (C) include amine-based curing agents (aliphatic polyamines, aromatic polyamines, tertiary amines, polyamide resins), polysulfide resins, acid anhydrides, dicyandiamide, BF, -amine complexes, acid hydra seeds, imidazoles. etc. can be mentioned.

Furthermore, pigments, fillers, antioxidants, ultraviolet absorbers, etc. can be added as necessary.

Possible uses of the resin composition of the present invention include paints, adhesives, electrical insulation materials, etc. In all cases, it exhibits excellent mechanical strength, electrical properties, and chemical resistance, as well as excellent flexibility and impact resistance. , indicates peeling strength.

The present invention will be explained in more detail below with reference to Synthesis Examples, Examples, and Comparative Examples.

Synthesis Example 1 Using benzyl sodium as an initiator and toluene as a chain transfer agent, butadiene was polymerized at 40°C in a benzene solvent to obtain a number average molecular weight lo00, 1°2-bond-containing ffi
6096 butadiene low polymer was obtained.

1000 g of this butadiene low polymer, 1 maleic anhydride
89.6g (0 for 100g of butadiene low polymer)
．． 19 mol), 2 g of Antigen 3C (gelling inhibitor, trade name manufactured by Sumima Kagaku Kogyo Co., Ltd.) and 10 g of xylene were placed in a 3N separable flask equipped with a reflux condenser, and after purging the system with nitrogen, the mixture was heated at 195°C for 5 hours. A maleation reaction was performed. After the reaction was completed, the solvent and unreacted substances were distilled off under reduced pressure to obtain a maleated butadiene low polymer (A-1) with an acid value of 100 mg KOH/g.

200 g of this maleated butadiene low polymer (A-1)
39.9g of γ-aminocaproic acid, 100g of MIBK
1. After reacting at 100°C for 1 hour in a separable flask of Il, the water and MIBK produced were distilled off at 150°C under a reduced pressure of 5 mmHg to give an acid value of 83 ag KO.
II/g of a butadiene low polymer derivative (B-1) was obtained.

Synthesis Example 2 1000 g of high CLS-1,4-type butadiene low polymer having a number average molecular weight of 900 obtained by coordination anionic polymerization using a nickel-based catalyst and 356 g of maleic anhydride.
(0.36 mol per 100 g of butadiene low polymer)
From, the acid value was 150 a+g by the same operation as in Synthesis Example 1.
KOH/f maleated butadiene low polymer (A-2)
I got it.

300 g of this maleated butadiene low polymer (A-2)
After adding 94.3 g of β-alanine and 50 g of water to the mixture and reacting at 100°C for 2 hours in a separable flask,
Water was distilled off at 160° C. under a reduced pressure of 5+++ mHg to obtain a butadiene low polymer derivative (B-2) with an acid value of 114 mgKOH/g.

Synthesis Example 3 Using benzyl sodium as an initiator and toluene as a chain transfer agent, butadiene was polymerized at 40°C in a benzene solvent, and the number average molecular weight was 650, 1°2-bond containing 1i 6
096 butadiene low polymer was obtained.

2000 g of this butadiene low polymer, 3 maleic anhydride
25.6g (0 per 100g of butadiene low polymer)
．． 17 mol) and antigen (306 g) were placed in a 5,11 separable flask equipped with a reflux condenser, the flask was purged with nitrogen, and a maleation reaction was carried out at 195° C. for 6 hours. After the reaction, the solvent and unreacted substances were distilled off under reduced pressure to reduce the acid value to 8.
A maleated butadiene low polymer (A-3) of 0 o+g KOH/g was obtained.

500 g of this maleated butadiene low polymer (A-3)
52.5 g of glycine was added to the mixture, and the mixture was reacted at 120°C for 1 hour. The water produced was distilled off at 160°C under a reduced pressure of 5 mm Hg to obtain a butadiene low polymer derivative (B- 3) was obtained.

Synthesis Example 4 Using benzyl sodium as an initiator and toluene as a chain transfer agent, butadiene was polymerized in a benzene solvent at 40°C to obtain a number average molecule m 1500.1° 2-bond containing m63
% butadiene oligomer was obtained.

1000 g of this butadiene low polymer, 1 maleic anhydride
87g (0.1 per 100g of butadiene low polymer)
9 mol) and Antigen 3C (4 g) were placed in a 3-vertical separable flask equipped with a reflux condenser, and the atmosphere was replaced with nitrogen.
The maleation reaction was carried out at 95°C for 6 hours. After the reaction is complete,
The solvent and unreacted substances were distilled off under reduced pressure, and the acid value was 90 a+.
g KOH/g of maleated butadiene oligomer (A
-4) was obtained.

100 g of this maleated butadiene low polymer (A-4)
11.8 g of glycine and 20 g of water were added to the mixture, and after reacting at 95°C for 2 hours in a 500-cm separable flask, the mixture was heated to 150°C.
Water was distilled off under a reduced pressure of 5 mm Hg, and the acid value was 80 m
g KOII/g of butadiene low polymer derivative (B
-4) was obtained.

Synthesis Example 5 In Synthesis Example 3, 2000 g of butadiene low polymer, 531.6 g of maleic anhydride (100 g of butadiene low polymer
0.27 mol) and 4 g of Antigen 3C were placed in a 3-vertical separable flask equipped with a reflux condenser, and after purging with nitrogen, a maleation reaction was carried out at 195° C. for 6 hours. After the reaction, the solvent and unreacted substances were distilled off under reduced pressure,
A maleated butadiene low polymer (A-5) having an acid value of 120 mgKOH/g was obtained.

200g of this maleated butadiene low polymer (A-5)
31.5 g of glycine was added to the solution, and the reaction was carried out at 110°C for 2 hours. The water produced in the reaction was distilled off at 160°C under a reduced pressure of 3 rats Hg, and the acid value was 104 tag K.
OII/g derivative of butadiene low polymer (B-5)
I got it.

Comparative Example 1 A coating composition was prepared by dissolving 80 g of Beckamine P-138 (manufactured by Dainippon Ink ■, urea resin), which is commercially available as a crosslinking agent for epoxy resin, and 100 g of Epicoat 1001/1001 in xylene and 100 g of butanol. The physical properties of this coating film were evaluated in accordance with J I 5K5400. The results are shown in Table 1.

Example 1 Derivative of butadiene low polymer synthesized in Synthesis Example 2 (B
2) 76.5g and 100g of Epicoat 828 (manufactured by Yuka Shell Epoxy ■, epoxy equivalent 184-194)
was dissolved in 50 g of MIBK, 0.5 g of triphenylphosphine was added to the catalyst, and the mixture was reacted at 100° C. for 1 hour. 17 g of isophoronediamine was added to the varnish containing the obtained prepolymer and cured at room temperature. The physical properties of the coating film after 7 days of the cured product were evaluated in the same manner as in Comparative Example 1. The results are shown in Table 1, and even compared to Comparative Example 1, it showed extremely excellent flexibility.

Comparative Example 2 20 g of Epicote 1004 dissolved in methyl isobutyl ketone was added to 100 g of Niraso PBC-1000 (manufactured by Nippon Naeda), which is a commercially available carboxyl group-containing polybutadiene.
0g was added and stirred to make it uniform, but phase separation occurred after -8 and it was impossible to apply it uniformly.

Example 2 Derivative of butadiene low polymer synthesized in Synthesis Example 3 (B-
3) 30g of Epicoat 828/70g was reacted with 0.1g of triphenylphosphine as a catalyst at 100°C for 1 hour to obtain a prepolymer.

Add to this prepolymer dicyandiamide IOK, 2-phenyl-4-methyl-5-hydroxymethylimidazole Q, 2 g, Aerosil A-300 (11 pieces of Aerosil ■
JI 5K6850, JISK685
The shear adhesive strength and T-peel adhesive strength of test panels cured at 180° C. for 30 minutes in accordance with 4 were measured.

As shown in Table 2, the results showed excellent shear bond strength and peel bond strength. It can be seen that the peel adhesion strength has been improved to 11] compared to Comparative Example 3.4, which will be described later.

Comparative Example 3 dicyandiamide 16g in Epicote 828/100g
, 0.2 g of 2-phenyl-4-methyl-5-hydroxymethylimidazole, and 3002 g of Aerosil A-3 were cured in the same manner as in Example 2, and the shear adhesive strength and T-peel adhesive strength were determined. Ta. The results are shown in Table 2.

Comparative Example 4 Epicote 828/70g, Niraso PBC-1000
(Same as Comparative Example 2) 30g of catalyst was reacted with 0.2g of triphenylphosphine at 100°C for 1 hour. After that, curing agent etc. were blended as in Example 6, and shear adhesive strength, T-peel The adhesive strength was determined. The results are shown in Table 2.

It can be seen that the T-peel adhesion strength is inferior compared to Example 2 or Example 3, which will be described later.

Example 3 Derivative of butadiene low polymer synthesized in Synthesis Example 5 (B
-5) 30 tr, Epicote 828/70g was reacted according to Example 2. After that, 8 g of adipic acid dihydrazide, 0.2 g of 12-phenyl-4-methyl-5-hydroxymethylimidazole, Aerosil A-300
2g was blended, and the shear adhesive strength and T-peel adhesive strength were determined in the same manner as in Example 2. The results are shown in Table 2.

Table-2

Claims (1)

[Scope of Claims] [1] (A) epoxy resin, (B) 100 g of butadiene low polymer having a number average molecular weight of 300 to 5,000, and 0.1 to 0.1 to 100 g of maleic anhydride.
After adding 1.5 mol, an additional 0.5-1.
1 equivalent (to the succinic anhydride group produced by adding maleic anhydride) of a derivative of a butadiene low polymer obtained by an addition reaction in a weight ratio of (A)/(B) of 95/5 to 40/
A thermosetting resin composition comprising: a prepolymer obtained by reacting at 0 to 300°C in a ratio of 60% to 300°C, and (C) a curing agent.