JPS61152724A - Thermosetting resin composition for composite material - Google Patents

Abstract

PURPOSE:To obtain the titled composition having excellent toughness, by compounding a polyepoxide, an aromatic amine hardener and a copolymerized polyamide having a specific glass transition temperature and containing a copolymerized component comprising an alicyclic diamine expressed by a specific formula, as copolymerizing components. CONSTITUTION:The objective composition can be produced by compounding (A) a polyepoxide [e.g. 1,4-bis(2,3-epoxypropoxy)benzene], (B) an aromatic amine hardener (e.g. m-phenylenediamine) and (C) a copolymerized polyamide having a glass transition temperature of >=60 deg.C and containing an alicyclic diamine of formula (R1, R2, R3 and R4 are H or methyl; n is 0-6) [e.g. a polyamide derived from bis(4-aminocyclohexyl)methane, etc.] as a copolymerized component. EFFECT:The toughness can be improved without lowering the heat-resistance. USE:Golf-shaft, fishing rod, structural material of aircraft, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a thermosetting resin composition for composite materials having excellent toughness.

[Conventional technology]

Composite materials made of reinforcing materials such as carbon fibers, glass fibers, and aromatic polyamide fibers and epoxy resins take advantage of their high specific strength and specific modulus to be used in premium sports applications such as golf shafts and fishing rods, as well as structures such as aviation acid. Widely used for materials. However, the epoxy resins used in these composite materials have insufficient performance for applications that require greater strength and toughness, and there is a strong desire for the emergence of epoxy resins with excellent toughness.

Many techniques have been proposed for improving the toughness of epoxy resins. One method is to add rubber such as acrylonitrile-butadiene copolymer to epoxy resin, and then cure the epoxy resin to form a rubber phase as a dispersed phase, which prevents cracks and improves adhesive strength. (For example, Japanese Patent Application Laid-Open No. 57-21
450). Other methods include adding and mixing thermoplastic resins such as polysulfone and polyarylates to epoxy resins to suppress the propagation of cracks in cured resins, and using these resins to improve the toughness of carbon fiber reinforced composite materials. There are methods (for example, THE BRITISHPOLYt
4ERJOURNAL, vol, 15. HARCH,1
983, P, 71°28THSAMPE SYMPO3
ItJH, 1983, P, 367, JP-A-58-1
34126). However, these methods are unsatisfactory in dramatically improving the toughness of composite materials, and furthermore, when these rubbers and thermoplastic resins are mixed, the viscosity of the epoxy resin becomes extremely high, making it difficult to manufacture or mold prepregs. Poor impregnation with reinforcing materials is likely to occur.

Modification of epoxy resins with various polyamide resins has also been studied for a long time. Japanese Patent Publication No. 40-1874 discloses an adhesive composition comprising an epoxy resin and methanol-soluble nylon, and Japanese Patent Publication No. 55-71771 discloses an adhesive composition comprising an epoxy resin, an alkenylphenol polymer, and copolymerized nylon or nylon 12. JP-A-56-1.52832 discloses a powder epoxy resin composition for coating films comprising a solid epoxy resin, a solid resol type phenol resin, and a linear polyamide resin. There is. Also, U.S. Patent No. 2,705.223, 2,986
, 539 and JP-A-58-53913 disclose a composition comprising a dimer acid polyamide and an epoxy resin, or a prepreg comprising this composition and reinforcing fibers.

The compositions made of epoxy resin and polyamide resin exemplified above are clearly different in structure and effect of the present invention, and are unsatisfactory as thermosetting resins for composite materials with excellent toughness.

(Problems to be Solved by the Invention) The purpose of the present invention is to provide a thermosetting resin composition for composite materials with excellent toughness, and more specifically, to provide a thermosetting resin composition for composite materials that has excellent toughness. The present invention provides a resin composition that enables the production of composite materials with less damage.

[Means for solving problems]

The present invention provides (1) a thermosetting resin composition for a composite material comprising the following [A], [B] and [C] as essential components.

[A] Polyepoxide CB) Aromatic amine curing agent [C] A resin represented by the general formula (wherein R1, R2, R3 and R4 represent a hydrogen atom or a methyl group, and n represents an integer of O to 6) Cyclic diamine is used as a copolymerization component, and the glass transition temperature is 60.
Copolymerized polyamide above °C.

(2) A thermosetting resin composition for a composite material, wherein the component [B] in claim (1) is diaminodiphenylsulfone.

(3) A thermosetting resin composition for a composite material in claim (1), wherein R1, R2, R3, and R4 in general formula (1) of component [C] are hydrogen atoms.

(4) In claim (1), R1 and R2 of general formula (1) of component [C] are methyl groups, R3 and R4
A thermosetting resin composition for composite materials in which is a hydrogen atom.

(5) In claim (1), R1 and R2 in general formula (1) of component [C] are hydrogen atoms, R3 and R4
A thermosetting resin composition for composite materials, wherein is a methyl group.

It is related to.

Polyepoxides that can be used in the present invention are compounds that have on average more than one epoxy group in the molecule, and this epoxy group may be present as a terminal group or may be internal to the molecule. . The polyepoxide may be a saturated or unsaturated aliphatic, cycloaliphatic, aromatic or heterocyclic compound, and may also be a compound containing a halogen atom, a hydroxyl group, an ether group, etc., such as bisphenol. Examples include glycidyl compounds of A, F, and S, glycidyl compounds of cresol novolacs or fluorinol novolacs, glycidyl compounds of aromatic amines, and cycloaliphatic epoxy resins.

Specific examples of such polyepoxides include 1,4-bis(2,3-epoxypropoxy)benzene, 4.4'
-Bis(2,3-epoxypropoxy)diphenyl ether.

Another example of a polyepoxide is a glycidyl compound of polyhydric phenol. Polyhydric phenols that can be used for this purpose include, for example, resorcinol, catechol, hydroquinone, 2,2-bis(4-hydroxyphenyl)propane (bisphenol A), 2,2-bis(4-hydroxyphenyl)butane, bis( 4-hydroxyphenyl)
Sulfone (bisphael S), his(4-hydroxyphenyl)methane, tris(4-hydroxyphenyl)methane, 3,9-bis(3-methoxy,4-hydroxyphenyl)-2,4,8,10-tetra Oxaspiro [5
, 5] undecane, and further 2,2-bis(4-hydroxytetrabromofluoride) as a halogen-containing phenol.
This includes propane.

Another example of a polyepoxide is a glycidyl compound of a polyhydric alcohol. Alcohols that can be used for this purpose include, for example, glycerol, ethylene glycol,
Examples include pentaerythritol and 2,2-bis(4-hydroxycyclohexyl)propane.

Examples of polyepoxides with internal epoxy groups include 4
-(1,2-epoxyethyl)-1,2-epoxycyclohexane, bis(2,3-epoxycyclopentyl)
Ether, 3.4-epoxycyclohexylmethyl-(
Examples include 3,4-epoxy)cyclohexanecarboxylate.

Another example of a polyepoxide is a glycidyl compound of an aromatic amine. Aromatic amines that can be used for this purpose include diaminodiphenylmethane, metaxylylene diamine, m-amine phenol, p-amine phenol, and the like.

Among these polyepoxides, diglycidyl ether of bisphenol A, a glycidyl compound of talesol novolac or phenol novolak, a glycidyl compound of diaminodiphenylmethane, and a glycidyl compound of aminephenol are preferably used.

Specific examples of the aromatic amine curing agent used in the present invention include metaphenylene diamine, diaminodiphenylmethane, diaminodiphenylsulfone, para-aminobenzoic acid diester of neopentyl glycol, and diaminodiphenylsulfone is particularly preferably used. Ru. Furthermore, boron trifluoride/amine complexes, imidazole compounds, and the like can also be used as curing accelerators.

The transparent polyamide used in the present invention is a copolymerized polyamide containing an alicyclic diamine represented by the general formula as a copolymerized component and having a glass transition temperature of 60° C. or higher. This alicyclic diamine can be produced by nuclear hydrogenation of the corresponding aromatic diamine, and is usually obtained as a mixture of trans-trans, trans-cis and cis-cis stereoisomers.

Preferred examples of alicyclic diamines and examples of copolyamides using the same are listed below.

A preferred example of a copolyamide containing bis(4-aminocyclohexyl)methane diamine as a copolymerization component is produced from a mixture of ε-caprolactam, bis(4-aminocyclohexyl)methane, hexamethylene diamine, and adipic acid. Other preferred examples include JP-A-54-22495 and JP-A-48-65.
No. 295 and Japanese Unexamined Patent Publication No. 115420/1983.

A preferred example of a copolyamide containing bis(4-amine, 3-methylcyclohexyl)methane diamine as a copolymerization component is disclosed in West German Published Patent Application No. 2,642,244.

2.2-His(4-aminocyclohexyl)propane:
Preferred examples of copolyamides containing this diamine as a copolymerization component include Japanese Patent Publication No. 52-20517 and U.S. Patent No. 4.
No. 028.476 and POLYHERENGINEE
RING AND 5CIENCE, VOL, 18. N
O,1,P36゜Disclosed in 1978.

The copolyamide used in the present invention must have a glass transition temperature of 60''C or higher, and must also have appropriate rigidity and toughness.

Polyamides whose glass transition temperature is lower than 60'C are difficult to mix homogeneously with epoxy resins, and the prepregs have poor flexibility and are not easy to handle.

In general, using a copolyamide having a glass transition temperature of 100'C or higher has the advantage of increasing the toughness without impairing the heat resistance of the epoxy resin. T! A polyamide having a temperature of 11100°C or higher can be obtained by increasing the amount of copolymerized alicyclic diamine. That is, TF is usually determined by the amount of alicyclic diamine.

The amount of polyamide used is 5 to 100 parts by weight, preferably 10 to 30 parts by weight, based on 100 parts by weight of the total amount of polyepoxide and curing agent.

If the amount of polyamide used is less than 5 parts by weight, the effect of improving the toughness of the composite material will not be sufficient, while if it is more than 100 parts by weight, homogeneous mixing of the composition will be difficult and the composition will deteriorate. The viscosity increases, making it difficult to uniformly impregnate reinforcing fibers.

There is no particular restriction on the method of mixing each component to obtain the composition of the present invention, but as an example, a homogeneous solution is prepared using a common solvent for each component (A>, [B], and [C]). There is a mixing method, and in this case, a method is preferably used in which component [C] is dissolved at a relatively high temperature, and then components (A> and [B] are added and dissolved after lowering the temperature.On the other hand, When mixing without using a solvent, it is preferable to uniformly mix component (A) and component [C] at a relatively high temperature, and then lower the temperature and mix component [B]. .

[Effect]

In the present invention, by combining polyepoxide, an aromatic amine curing agent, and a specific copolyamide,
A thermosetting resin composition is provided that improves the brittleness of an epoxy resin and provides a tough composite material. By selecting a combination of polyepoxide and an aromatic amine curing agent, it is possible to obtain an epoxy resin with heat resistance according to the application and purpose, and by combining a copolymerized polyamide with excellent heat resistance, the heat resistance of the epoxy resin can be improved. The toughness can be increased without compromising the strength.

〔Example〕

The invention will be explained in more detail by the following examples. In the following examples, the amounts of each component are in parts by weight, and the content of the polyepoxide is as follows.

Epoxy A: bisphenol A diglycidyl ether,
Epicoat 828° manufactured by Yuka Shell Epoxy Co., Ltd. Epoxy B Nidiaminodiphenylmethane tetraglycidyl compound, ELM434° manufactured by Sumitomo Chemical Co., Ltd. Epoxy C: Tetrabromo bisphenol A diglycidyl ether, Epiclon 152° manufactured by Dainippon Ink Co., Ltd. Moreover, the following copolyamide was used.

Polyamide A: Polyamide obtained by polycondensation of a mixture consisting of 35 parts of ε-caprolactam, 308IS, an equimolar salt of hexamethylenediamine/adipic acid, and 35 parts of an equimolar salt of bis(4-aminocyclohexyl)methane/adipic acid. Relative viscosity (measured by dissolving 1 g of sample in 100 ml of 98% sulfuric acid and using an Ostwald viscometer at 25°C>2.
45. Glass transition temperature (measured using a DuPont 990 differential calorimeter at a heating rate of 40°C/min) 75°C
0 Polyamide B: Polyamide obtained by polycondensation of a mixture consisting of 40 parts of ε-caprolactam, 35 parts of an equimolar salt of hexamethylenediamine/adipic acid, and 25 parts of an equimolar salt of hexamethylenediamine/sebacic acid. Relative viscosity 2.6
0, glass transition temperature 42°C.

Polyamide C: 60 parts and 2.2 parts of equimolar salt of 2,2-bis(4-aminocyclohexyl)propane azelaic acid
- A polyamide obtained by polycondensing a mixture consisting of 40 parts of an equimolar salt of bis(4-aminocyclohexyl)propane/adipic acid. Relative viscosity, 2°64, glass transition temperature 185°C
.

Polyamide 033 parts (4-amino, 3-methylcyclohexyl) A polyamide obtained by polycondensing a mixture consisting of 70 parts of an equimolar salt of methane-isophthalic acid and 30 parts of laurolactam. Relative viscosity 1.95, glass transition temperature 150°C.

Example 1 33 parts of polyamide A was placed in a mixed solvent consisting of 200 parts of methanol and 200 parts of trichlene, and uniformly dissolved while stirring at 50°C. After cooling this solution to room temperature, 100 parts of epoxy A and 3 parts of diaminodiphenylsulfone were added.
2 parts were added to prevent dissolution. Apply this solution to a plain weave cloth using carbon fiber "Torayka" T300 manufactured by Toshiku Co., Ltd. with a resin content of 4.
It was applied and impregnated to a concentration of 1%. - After sun drying, 12
24 homogeneous prepregs obtained by heating and drying at 0°C for 5 minutes were laminated and heated at 180°C using an autoclave.
Cured for 12 hours at a pressure of 6 kg/c+f,
A composite material with a thickness of about 5 mm was obtained. This composite material has a R16 tip.
A dropping energy of 680 ki·cm/cm (sample thickness) was applied using a weight of m1. The area of damage caused by this impact was measured using an ultrasonic flaw detection imaging device M400B manufactured by Canon Holosonic, and the result was 9. O
It was ci. Further, the glass transition temperature was 128°C.

Comparative Example 1 100 parts of epoxy A and 32 parts of diaminodiphenylsulfone were dissolved in 198 parts of methyl ethyl ketone at room temperature. A composite material was produced in the same manner as in Example 1 using this solution. The damage area of this composite material due to impact is 15.
5cIIf, the glass transition temperature was 180°C.

Example 2 33 parts of polyamide A was added to a mixed solvent consisting of 200 parts of methanol and 200 parts of trichlene, and uniformly dissolved while stirring at 50'C. After cooling this solution to room temperature,
Epoxy A 35 parts, Epoxy 835 parts, Epoxy 030
1 part and 34 parts of diaminodiphenylsulfone were added and dissolved.

A composite material was produced in the same manner as in Example 1 using this solution. As a result of measuring this composite material in the same manner as in Example 1, the damage area after impact was 9°1clf, and the glass transition temperature was 142°C.

Comparative Example 2 35 parts of epoxy A, 835 parts of epoxy, 030 epoxy
and 34 parts of diaminodiphenylsulfone were dissolved in 200 parts of methyl ethyl ketone.

A composite material was prepared using this solution in the same manner as in Example 1, and its impact properties were examined. Damage area after impact is 16.0
Q7f, the glass transition temperature was 210'C.

Comparative Example 3 820 parts of polyamide was heated and dissolved at 50° C. using a mixed solvent consisting of 150 parts of methanol and 150 parts of trichlene to obtain a uniformly dissolved solution.

After cooling this solution to room temperature, 100 parts of epoxy A and 7 parts of dicyandiamide were added and dissolved.

A prepreg was produced using this solution in the same manner as in Example 1, but the epoxy resin and polyamide were not completely dissolved and the prepreg was heterogeneous.

Example 3 033 parts of polyamide was placed in a mixed solvent consisting of 230 parts of ethanol and 230 parts of trichlene, and uniformly dissolved while stirring at 50'C. To this solution were added and dissolved 35 parts of epoxy A, 835 parts of epoxy, and 030 parts of epoxy while stirring. After cooling the resulting solution to room temperature, 34 parts of diaminodiphenylsulfone was added to 2 parts of methyl ethyl ketone.
00 parts of the solution was added with stirring to obtain 1 q of a homogeneous solution. A composite material was produced in the same manner as in Example 1 using this solution. The damage area of this composite material due to impact is 8
．． 3 rA, and the glass transition temperature was 180'C.

Example 4 A composite material was produced in the same manner as in Example 3 except that polyamide D was used instead of polyamide C, and its properties were measured. As a result, the damaged area was 7.9 cnf and the glass transition temperature was 2.
It was 17°C.

(Effect of the invention〕 (1) Damage to the composite material due to impact is reduced.

(2) A homogeneous resin composition with excellent toughness can be obtained.

(3) A composite material with excellent heat resistance is provided.

(4) Prepreg and composite materials with stable quality can be produced.

(5) Composite materials can be molded using an autoclave without requiring special conditions.

Patent Applicant Higashishi Co., Ltd. Company procedure amendment method) 1. Indication of the case Patent Application No. 273861 filed in 1982 2. Name of the invention Thermosetting resin composition for composite materials 3. Person making the amendment Related Patent Applicant Address 2-2 Nihonbashi Muromachi, Chuo-ku, Tokyo 1982
April 30, 2017 (shipment date) 5. Number of inventions increased by amendment None 6. Column X6 of "Detailed description of the invention" of the specification subject to the amendment 7. Contents of the amendment (1) Specification No. 3 Page lines 15-18 “(For example, T
HE BRITISH POLYMER JOURNAL,
vol, 15. )iARCH, 1983゜P, 71.2
8th 5AHPE 5Y) IPO3IU) 1.198
3. P, 367, Japanese Unexamined Patent Publication No. 134126/1983)
[For example, The British Polymer Journal Vol. 15, March 1983 (THE BRIT
ISHPOLYMERJOUllNAL, vol, 15
．． ) IARCH, 1983), P, 71. 28th Sanpe Simposi 961983 (8th 5AHPE
5YHPO3IUH, 1983) P, 367, ¥
Ff Patent Publication No. 58-134126].

Claims (5)

[Claims] (1) A thermosetting resin composition for composite materials comprising the following [A], [B] and [C] as essential components. [A] Polyepoxide [B] Aromatic amine curing agent [C] General formula ▲ Numerical formula, chemical formula, table, etc. ▼ (1) (In the formula, R_1, R_2, R_3 and R_4 are hydrogen atoms or methyl groups, A copolymerized polyamide containing an alicyclic diamine represented by (n represents an integer of 0 to 6) as a copolymerization component and having a glass transition temperature of 60°C or higher. (2) A thermosetting resin composition for a composite material in claim (1), wherein component [B] is diaminodiphenylsulfone. (3) A thermosetting resin composition for a composite material in claim (1), wherein R_1, R_2, R_3, and R_4 in general formula (1) of component [C] are hydrogen atoms. (4) In claim (1), R_1 and R_2 of the general formula (1) of component [C] are methyl groups, R_3, R
A thermosetting resin composition for composite materials, wherein _4 is a hydrogen atom. (5) In claim (1), R_1 and R_2 of the general formula (1) of component [C] are hydrogen atoms, R_3, R
A thermosetting resin composition for composite materials, wherein _4 is a methyl group.