JPH05105738A - Modified epoxy resin and its production - Google Patents

Abstract

PURPOSE:To easily obtain the subject new resin having rubber elasticity without lowering the heat-resistance, etc., of epoxy resin, using a simple process by using a specific block copolymer as a modifying agent and reacting the agent with an epoxy resin under specific condition. CONSTITUTION:The objective resin of formula V is produced by mixing (A) an aramid-polybutadiene-acrylonitrile block copolymer containing phenolic hydroxyl group and expressed by formula I [Ar and Ar' are bivalent aromatic group and at least one of Ar and Ar' contains phenolic hydroxyl group; Ar1 is aromatic group having the unit of formula II, formula III, etc. ; (n) and (m) are charging ratio of Ar and Ar'; (1) is average polymerization degree and 1<=(1)<=100; (x) and (y) are compositional ratios of the butadiene unit and the acrylonitrile unit; y/(x+y) is 0.1-0.27; (z) is 1-15] and (B) an epoxy resin of formula IV (R is phenyl, H, etc.; R' and R'' are H or methyl; (q) is 0-10) at a ratio of 30/70 to 95/5, dissolving the mixture in an ether solvent and heating and reacting under refluxing in the presence of a tertiary amine catalyst.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a novel modified epoxy resin and a film-shaped molded product thereof, more specifically,
The present invention relates to an epoxy resin modified product composed of an aramid-polybutadiene-acrylonitrile block copolymer and an epoxy resin, and a method for producing the same.

[0002]

2. Description of the Related Art Epoxy resin has been extensively modified and its application range has been expanded. Epoxy resin has excellent electrical properties, adhesiveness, thermal properties, etc., but is generally fragile and easily cracks due to internal stress strain during curing reaction and use, and external stress such as heat and mechanical shock. There was a problem such as. To solve this problem, use of epoxy resin curing agents having long-chain aliphatic groups or rubbery properties, addition of compounds having elastomeric properties, addition of plasticizers such as asphalts and glycols, glass fibers, aramid fibers ,
The toughness of the epoxy resin itself has been increased by adding reinforcing fibers such as carbon fibers and short metal fibers and introducing molecular groups showing rubber elasticity into the epoxy resin itself (Koichi Ochi, Polymer 3
8 (3), 200 (1989)).

[0003]

However, these modifying substances are not sufficiently compatible with the epoxy resin, and satisfactory composite properties such as improvement in toughness cannot be obtained. The excellent heat resistance and adhesiveness of the resin are impaired, and problems such as extremely high cost occur.

The present invention has been made in view of these problems, and is represented by the above-mentioned general formula (I) which is a modifier without reducing the heat resistance and adhesiveness of the epoxy resin. It is an object of the present invention to provide a method for arbitrarily controlling the addition amount of an aramid-polybutadiene-acrylonitrile block copolymer having a phenolic hydroxyl group, and a method for producing a modified epoxy resin and a film-shaped molded product thereof.

[0005]

Means for Solving the Problems As a result of intensive studies for solving the above problems, the present inventors have found that an aramid-polybutadiene-acrylonitrile block copolymer having a phenolic hydroxyl group represented by the general formula (I). (First component),

[Chemical 8] (In the formula, Ar and Ar ′ are divalent aromatic groups, which may or may not have the same structure, and at least one of which has one or more phenolic hydroxyl groups. ₁
Is an aromatic group having a structural unit represented by the following general formulas (1) to (6). In the formula, n and m represent the charging ratio of Ar and Ar ′ constituting the block unit, and 1 represents the degree of polymerization and is represented by an integer of 1 ≦ l ≦ 100.

[Chemical 9] Furthermore, x and y represent the composition ratio of the butadiene gene unit and the acrylonitrile unit, and y / (x + y) = 0.1
In the range of 0.27, z represents an integer of 1 to 15. ), By reacting with an epoxy resin represented by the general formula (II) (second component)

[Chemical 10] (In the formula, R represents a substituent, a phenyl group, a phenyl group having an alkyl group, a phenyl group having an alkoxy group, an aromatic group consisting of a phenyl group having chlorine or bromine as a substituent, or a methyl group. Etc. means an alkyl group having 4 or less carbon atoms, or a hydrogen atom, or chlorine or bromine, and R ′ and R ″ represent a methyl group or a hydrogen atom,
q represents the number of repeating units and is represented by the number 0 ≦ q ≦ 10). By using the obtained modified epoxy resin represented by the following general formula (III), the heat resistance of the epoxy resin and To obtain an epoxy resin-modified body having rubber elasticity without reducing properties such as mechanical strength.
Further, they have found that the mixing ratio of the first component and the second component can be freely controlled, and completed the present invention.

[Chemical 11] (In the formula, Ar, Ar ′, Ar ₁ , n, m, 1, x, y,
z and q have the above meanings, and the phenolic hydroxyl group contained in the aramid part reacts with one of the epoxide groups at both ends of the epoxy resin, while the other epoxide group remains unreacted. Is in a state)

The epoxy resin-modified product and the film-shaped molded product thereof of the present invention are obtained by subjecting the first component represented by the general formula (I) and the second component represented by the general formula (II) to a third component in an ether solvent. It can be produced by reacting under reflux conditions in the presence of a primary amine. Explaining the production method of the present invention further, the phenolic hydroxyl group-containing block copolymer as the first component is an ether solvent that does not react with the phenolic hydroxyl group of the block copolymer, in relation to the ether solvent. 1 to 30% by weight, preferably 1
It is used by dissolving it in a concentration of 10% by weight. The phenolic hydroxyl group-containing block copolymer has a mixing weight ratio of 30/70 to 95 to the epoxy resin as the second component.
It is necessary to mix and use in the range of / 5. If the mixing weight ratio is less than 30/70, the viscosity of the modified epoxy resin will increase, and it will be difficult to produce a film-like molded product having self-supporting properties. On the other hand, if the mixing weight ratio is higher than 95/5, unreacted phenolic hydroxyl groups in the aramid block copolymer increase, and the heat resistance and mechanical strength of the modified epoxy resin are lowered, which is not preferable.

Examples of the ether solvent used in the present invention include cyclic ethers such as tetrahydrofuran, dioxane, ethylene oxide and propylene oxide, and chain ethers such as diglyme. Tetrahydrofuran, 1,4-dioxane and diglyme are preferably used in that they dissolve the epoxy resin together and do not form by-products during the reaction.

The phenolic hydroxyl group-containing block copolymer [general formula (1)] used in the present invention can be produced by the following method. That is, an aromatic dicarboxylic acid not having a phenolic hydroxyl group and an aromatic dicarboxylic acid component having a phenolic hydroxyl group are added with an excess amount of an aromatic diamine such as oxydianiline, and the presence of, for example, a phosphite ester and a pyridine derivative Under an organic solvent represented by N-methyl-2-pyrrolidone,
In an inert atmosphere such as nitrogen, polycondensation having a carboxyl group at both ends is formed in the aramid oligomer solution by heat polycondensation to form an aramid oligomer solution having a phenolic hydroxyl group whose both ends are aminoaryl groups. -A block copolymer [general formula (1)] used in the present invention can be obtained by adding an acrylonitrile copolymer and polycondensing it.

Examples of the dicarboxylic acid component having a phenolic hydroxyl group include 4-hydroxyisophthalic acid and 5-hydroxyisophthalic acid.
Hydroxyisophthalic acid, 2-hydroxyphthalic acid, 3
-Hydroxyphthalic acid, 4-hydroxyterephthalic acid, 2-hydroxyterephthalic acid and the like can be mentioned. Further, examples of the aromatic dicarboxylic acid having no phenolic hydroxyl group include phthalic acid, isophthalic acid, terephthalic acid and the like. Furthermore, 3,3 'as oxydianiline
-Oxydianiline, 3,4'-oxydianiline,
4,4'-oxydianiline and the like are used, and diamines containing Ar represented by the general formulas (1) to (6) are preferable. As the polybutadiene-acrylonitrile copolymer having a carboxyl group at both ends, for example, Hycar CTBN manufactured by Goodrich Co. can be applied.

The aramid-polybutadiene-acrylonitrile block copolymer having a phenolic hydroxyl group and used in the present invention represented by the general formula (I) has a η value of 0.01 in the viscosity formula represented by the following formula. ≤η≤
2.0, preferably 0.1 ≦ η ≦ 0.8. If the η value is less than 0.01, the rubber elasticity of the obtained modified epoxy resin is not satisfied, and if the η value exceeds 2.0,
It is not preferable because the heat resistance and mechanical strength of the modified epoxy resin are not satisfied. η = 1n (t ₁ / t ₀ ) / (polymer solution concentration: C) (In the formula, t ₁ represents the polymer solution drop time in the Oswald-type viscometer, and t ₀ represents the drop time of the organic solvent that dissolves the polymer. Polymer concentration: C is 0.1 ≦ C ≦
It shows that it is 0.5 (g / dl). The measurement conditions are constant temperature of 30 ° C. and dimethylacetamide. )

The above general formula (I
Examples of the epoxy resin represented by I) include bisphenol A type, bisphenol F type, bisphenol AD type, bisphenol S type, and bisphenol type epoxy resins such as chlorinated or brominated products thereof.

The reaction catalyst used in the present invention is a tertiary catalyst such as dimethylbenzylamine, dimethylethylamine, N-dimethylnaphthylamine, triallylamine and 1,8-diazabicyclo [5,4,0] -undec-7-ene. Examples thereof include primary amines, and dimethylbenzylamine and 1,8-diazabicyclo [5,4,0] -undec-7-ene are preferably used because they do not react with phenolic hydroxyl groups and epoxide groups.

In the present invention, the epoxy resin-modified film-like molded product is obtained by casting the epoxy resin-modified product dissolved in an ether solvent onto a suitable substrate such as a glass plate, a metal plate or a Teflon plate, By spontaneously evaporating the ether solvent and then drying it under reduced pressure, an elastomeric film-like molded product can be easily obtained. Further, it is possible to produce a heat resistant film by curing the film-shaped molded article by heating.

[0014]

EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited thereto. Synthesis example 1. <Preparation of Aramid-Polybutadiene-Acrylonitrile Block Copolymer (A) Having Phenolic Hydroxyl Group (phenolic hydroxyl group content of aramid portion: 10 mmol%)>3,4'-oxydianiline 2.202 (11 mmo
l) and 0.182 g of 5-hydroxyisophthalic acid (1 m
mol) and 1.495 g (9 mmol) of isophthalic acid,
0.33 g of lithium chloride, 1.01 g of calcium chloride,
20 ml of N-methyl-2-pyrrolidone, 3 m of pyridine
1, and 6.2 g of triphenyl phosphite were placed in a 100 ml three-necked round bottom flask and reacted under dry nitrogen at 90 ° C. for 2 hours to prepare an aramid oligomer solution. next,
In the aramid oligomer solution, a polybutadiene-acrylonitrile copolymer having both carboxyl groups at both ends [H
ycarCTBN (trade name, average molecular weight 3600, Go
odrich)] 3.6 g (corresponding to 1 mmol) 4
What was made into a solution by dissolving in 0 ml of pyridine was added to the reactor, and after reacting for 2 hours, it was cooled to room temperature,
The reaction solution was poured into 11 methanol to precipitate a polymer, which was further washed with methanol and refluxed with methanol for purification to obtain an aramid-polybutachen-acrylonitrile block copolymer used in the present invention. The intrinsic viscosity of this block copolymer was 0.92 dl / g.
Was measured infrared spectrum by diffusion reflection method the block copolymer fines, amide carbonyl group 1674Cm ^-1, the absorption by C-H stretching of butadiene portion 2850-2975Cm ^-1, nitrile groups to 2245 cm ^-1 Based on the above, absorption was confirmed.

Synthesis Example 2. <Preparation of Aramid-Polybutadiene-Acrylonitrile Block Copolymer (B) Having Phenolic Hydroxyl Group (phenolic hydroxyl group content of aramid portion: 5 mmol%)> Synthesis Example 1. 5-hydroxyisophthalic acid 0.182g
(1 mmol) and 1.495 g of isophthalic acid (9 mmo
l) of 5-hydroxyisophthalic acid 0.091 g (0.
5 mmol) and isophthalic acid 1.578 g (9.5 mm)
ol) was used, and the same synthesis was performed to obtain an aramid-polybutadiene-acrylonitrile block copolymer used in the present invention. The intrinsic viscosity of the obtained block copolymer was 0.80 dl / g. Was measured infrared spectrum by diffusion reflection method fines of this block copolymer, amide carbonyl group 1675 cm ^-1, 2
Absorption in 854-2976Cm ^-1 by C-H stretching of butadiene portion was confirmed based on mutual agreement absorbing the nitrile group in 2240 cm ^-1.

Example 1 Phenolic hydroxyl group-containing aramid obtained in Synthesis Example 1
Polybutadiene-acrylonitrile block copolymer (A) 1.0 g, Epicoat 828 as epoxy resin
(Average molecular weight 380, epoxy equivalent 190 ± 5, manufactured by Yuka Shell Epoxy Co., Ltd.) 1.0 g was put in a 200 ml round bottom flask and dehydrated 100 ml of tetrahydrofuran
And 0.05 g of dimethylbenzylamine are added and reacted for 4 hours under reflux to obtain the epoxy resin-modified product solution of the present invention. Then, the epoxy resin-modified product solution is entirely poured onto a glass Petri dish and dried as it is to form a film. A shaped article was obtained. The obtained film-shaped molded product was reduced under reduced pressure (1
It was heat-cured at 180 ° C. (0 ⁻⁴ torr).

Example 2 The same procedure as in Example 1 was repeated except that the tetrahydrofuran used as the reaction solvent in Example 1 was replaced with 1,4-dioxane to obtain the modified epoxy resin of the present invention. The film-shaped molded product was obtained.

Example 3 1.0 block copolymer (B) of the present invention obtained in Synthesis Example 2
g, epoxy resin (Epicoat 828, average molecular weight 38
0, epoxy equivalent 190 ± 5, manufactured by Yuka Shell Epoxy Co., Ltd.) 1.0 g, and 1,8-ditezabicyclo [5,4,0] -undec-7-ene as a reaction catalyst.
To obtain a modified epoxy resin of the present invention,
Further, the film-shaped molded product obtained by casting the modified epoxy resin on a substrate was subjected to a reduced pressure (10 ⁻⁴ torr),
Heat cured at 0 ° C.

Example 4 The epoxy resin-modified product of the present invention was obtained in the same manner as in Example 3 except that the reaction solvent used in Example 3 was changed from tetrahydrofuran to 1,4-dioxane. The film-shaped molded product obtained by casting the solution was thermally cured at 180 ° C. under reduced pressure.

Example 5 The same procedure as in Example 1 was carried out except that the reaction solvent tetrahydrofuran used in Example 1 was replaced with diglyme to obtain the epoxy resin modified product solution of the present invention, which was further cast to form a film. A shaped article was obtained.

Comparative Example Epicoat 828 (10 g, 10 parts by weight) and butadiene-acrylonitrile copolymer having carboxyl groups at both ends (10 g, 10 parts by weight) were heated and mixed at 130 ° C. to prepare an epoxy resin mixture. After that, 1.291 g (6.6 mmol) of melted bis (4-aminophenyl) methane was added all at once, and after uniformly mixing, the surface was cast on a 200 μm polyester film having a release treatment, and under vacuum. The mixture was heated at 90 ° C. for 3 hours and then cured at 180 ° C. for 6 hours to prepare a film-shaped molded product of a modified epoxy resin for comparison.

Table 1 shows the mechanical strength of the film-shaped molded products obtained from the modified epoxy resin in Examples 1 to 5 and Comparative Example. As a result, the modified epoxy resin of the present invention had practically sufficient mechanical strength and excellent flexibility.

[0023]

[Table 1]

Mechanical Strength Testing Method Testing machine. Universal tensile tester (UC made by Orientec Co., Ltd.
T-100) Measurement conditions. Tensile speed: 50 mm / min, load cell: 1
0 kgf (25 ° C) test piece. 10 mm x 100 mm x 50 μm

[0025]

INDUSTRIAL APPLICABILITY The modified epoxy resin of the present invention is useful because it can be easily and conveniently produced in a highly volatile organic solvent and can be handled as a film, so that it can be used as a film adhesive. .. In addition, it has higher heat resistance than ordinary epoxy resins and is highly useful as a material with a wide range of applications.

Claims (5)

[Claims] 1. The following general formula (I): (In the formula, Ar and Ar ′ are divalent aromatic groups, which may be the same or different, and at least one is
Ar ₁ has at least one phenolic hydroxyl group, and Ar ₁ represents an aromatic group having a structural unit represented by the following formulas (1) to (6). [Chemical 2] In addition, n and m represent the charging ratios of Ar and Ar ′ constituting the block unit, l is the average degree of polymerization, and 1 ≦ l ≦
Represents an integer of 100. Furthermore, x and y represent the composition ratio of the butadiene gene unit and the acrylonitrile unit,
y / (x + y) = 0.1 to 0.27, and z
= 1 to 15 is an integer. ) An aramid-polybutadiene-acrylonitrile block copolymer having a phenolic hydroxyl group represented by the following general formula (II): (In the formula, R represents a substituent, and is a phenyl group, a phenyl group having an alkyl group, a phenyl group having an alkoxy group, an aromatic group consisting of a phenyl group having chlorine or bromine as a substituent, or having 4 carbon atoms. The following alkyl groups,
Or a hydrogen atom, chlorine, bromine, R ′,
R ″ represents a hydrogen atom or a methyl group, q represents the number of repeating units, and represents an epoxy resin represented by 0 ≦ q ≦ 10), represented by the following general formula (III): (In the formula, Ar, Ar ′, Ar ₁ , x, y, z, 1, m,
n, R, R ', R "and q have the same meanings as above.)
A modified epoxy resin, having a structure represented by: 2. The following general formula (I): (In the formula, Ar, Ar ′, Ar ₁ , l, m, n, x, y,
z has the same meaning as above. ) An aramid-polybutadiene-acrylonitrile block copolymer having a phenolic hydroxyl group represented by the following general formula (II): (Wherein R, R ′, R ″, and q have the same meanings as described above) and a mixing weight ratio of 30 /
70 to 95/5 are mixed, the mixture is dissolved in an ether solvent, and the mixture is heated and reacted under reflux conditions in the presence of a tertiary amine as a reaction catalyst, to produce a modified epoxy resin. Method. 3. The production of modified epoxy resin according to claim 2, wherein the reaction catalyst is dimethylbenzylamine or 1,8-diazabicyclo [5,4,0] -undec-7-ene. Method. 4. The method for producing a modified epoxy resin according to claim 2, wherein the ether solvent is tetrahydrofuran, dioxane or diglyme. 5. The following general formula (III): (In the formula, Ar, Ar ′, Ar ₁ , x, y, z, 1, m,
(n, R, R ', R ", and q have the same meanings as described above), and a solution containing the modified epoxy resin is cast onto a surface-treated substrate to form a film-shaped molded product. Then, a method for producing a film-like cured product of an epoxy resin-modified body, which comprises heating and curing without using a catalyst.