JPH05222166A - Resin composition containing bisoxazoline - Google Patents

Abstract

PURPOSE:To prepare a resin compsn. suitable for a high-grade composite material and having an improved toughness by reacting a mixture comprising a diepoxide, a bisphenol compd., and a bisoxazoline compd. and specifying the cross-link density and toughness of the reaction product. CONSTITUTION:A mixture of 10-20mol% diepoxide. 40-45mol% bisphenol compd., and 40-45mol% bisoxazoline compd. is reacted to give a resin compsn. having a cross-link density of 35-60% and a toughness of 78.4kg/cm<3/2> (700psi-in<1/2>). The mixture is cured by heating to a temp. effective in intiating the reaction among functional groups of the diepoxide, bisphenol compd., and bisoxazoline compd., generally 140 deg.C or higher, pref. 140-180 deg.C, for about 2hr or longer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bisoxazoline resin composition, and more particularly to a bisoxazoline resin composition having excellent properties for high-grade composite use.

[0002]

BACKGROUND OF THE INVENTION Bisoxazoline is a thermosetting material which is known to provide high glass transition materials in the cured state. U.S. Pat.No. 4,652,260 discloses a reaction mixture of a bisoxazoline, an aromatic hydroxyl compound and an epoxy resin epoxide, and U.S. Pat. A curable prepolymer consisting of is disclosed. In the space industry there is a continuous need for high Tg materials such as bisoxazoline as matrix materials for high grade composites. However, in such applications, the additional required properties of the matrix material are toughness.
ess) and cured bisoxazolines tend to be fairly brittle. The present invention is suitable for use in high end composite applications,
An object of the present invention is to provide a bisoxazoline resin composition having improved toughness.

[0003]

DISCLOSURE OF THE INVENTION The present invention provides 10 to 20 mol% of diepoxide (a), 40 to 40 mol, per mixture.
A crosslink density of 35-60% and 7 produced by reacting a mixture containing 45 mol% bisphenol (b) and 40-45 mol% bisoxazoline.
A resin composition having a toughness of 8.4 kg / cm ^3/2 (700 psi in ^1/2 ) or more.

The composition of the present invention comprises bisoxazoline, diepoxide and bisphenol. In order to achieve the desired toughness, the proportions of these three components should be chosen such that after their interaction, a partially crosslinked bisoxazoline composition is obtained. The degree of crosslinking can be represented by the crosslinking density. The crosslink density of the cured bisoxazoline is 35-60%, preferably 37-57% to obtain a resin having a toughness of about 78.4 kg / cm ^3/2 (700 psi in ^1/2 ) or more, About 89.6kg / cm ^3/2 (800psiin
^In order to obtain a resin having a toughness of ^1/2 ) or more, it is most preferably 42 to 52%. Generally, highly crosslinked resins have toughness values of about 44.8 kg / cm ^3/2 (400 psi in ^1/2 ).

The term "crosslink density" used herein means that calculated by the following equation. Crosslinking density (%) = (excess equivalent weight / total equivalent weight) × 200 In the above formula, the “excess equivalent weight” means the excess of the equivalent weight of bisoxazoline and the stoichiometric amount required to react with bisphenol. It is the total equivalent of jiepoxide. This excess resin is 4 in the composition of the invention.
This value is 4 times the number of moles of the resin in excess of the stoichiometric amount because it can be considered to function as a functional molecule. The functionality of bisphenols is always 2, and the functionality of diepoxide / bisoxazoline (residual resin), which is less than or equal to the stoichiometric amount, based on bisphenol is 2. "Total equivalent weight" means [excess mole number x 4] +
[Remaining number of moles x 2] + [Number of moles of bisphenol x
2].

Therefore, in order to obtain a cured bisoxazoline resin having improved toughness, the mol% of bisoxazoline is 40-45%, preferably 4%, per mixture of bisoxazoline, bisphenol and diepoxide.
It has been found that it should be in the range of 2-45%. The mole% of diepoxide is 10-20% per mixture,
It should preferably be in the range of 10-16%. Generally, the bisphenol is present in an amount effective to cure the bisoxazoline and diepoxide. Generally, the mole% of bisphenol is 40-4 per mixture.
It is in the range of 5%, preferably 42 to 45%.

Suitable bisoxazolines can be represented by the general formula:

[0008]

[Chemical 1]

In the formula, each R independently represents hydrogen and C ₁ -C.
_{10 represents} an alkyl group, and Z represents a divalent residue having 2 to 40 carbon atoms. Z can be an aliphatic, cycloaliphatic, aromatic or heterocyclic residue, preferably an aromatic residue. Examples of such bisoxazolines include, for example, 4,4 ′, 5,5′-tetrahydro-2,2′-bisoxazole; 2,2 ′-(alkylene) bis (4,5-dihydrooxazole), For example, 1,2-ethylene-2,2'-bis (4,5-dihydrooxazole), 1,2- (1,4-butylene) -2,2'-bis (4,5-dihydrooxazole); 2 ,
2 '-(arylene) bis (4,5-dihydrooxazole), such as 1,3-phenylene-2,2'-bis (4,5-dihydrooxazole) (PBO), 1,4-phenylene-2,2 '-
Bis (4,5-dihydrooxazole), 1,5-phenylene-2,2'-bis (4,5-dihydrooxazole) and 1,8-
It is phenylene-2,2'-bis (4,5-dihydrooxazole). In a preferred embodiment, the bisoxazoline has the formula:

[0010]

[Chemical 2]

(Wherein Z is a substituted or unsubstituted arylene group or a C ₁ -C ₁₀ alkylene group), and 2,2 '-(phenylene) bis (4,5-dihydrooxazole ) Is preferred.

Suitable diepoxides have a 1,2-epoxy equivalent weight of about 2. The diepoxides can be saturated, unsaturated, aliphatic, cycloaliphatic, aromatic and heterocyclic. Examples of diepoxides suitable for use in the present invention are diglycidyl ethers of divalent compounds such as diglycidyl ethers of dihydric phenols and diglycidyl ethers of bisphenolfluorenone. Preferred diepoxides are diglycidyl ethers of dihydric phenols, such as 2,2-bis (4-hydroxyphenyl) propane [bisphenol A], 2,2-bis (4-hydroxy-tert-butylphenyl) propane, 1 , 1-bis (4-hydroxyphenyl) ethane, bis (4-hydroxyphenyl) methane [bisphenol F], 1.1-bis (4-hydroxyphenyl) isobutane,
Bis (2-hydroxynaphthyl) methane, 1,5-dihydroxynaphthalene, 1,1-bis (4-hydroxy-3-alkylphenyl) ethane, 9,9-bis (4-hydroxyphenyl) fluorene, 1,1- Bis (4-hydroxyphenyl) indane, 9,9-bis (4-hydroxyphenyl) xanthene, 1
0,10-bis (4-hydroxyphenyl) anthrone, 9,9-
Examples include bis (4-hydroxyphenyl) phenanthrone.

The diglycidyl ether of dihydric phenol can be produced by reacting an epihalohydrin such as epichlorohydrin with a dihydric phenol in the presence of an alkali. A commercially available product of a suitable epoxy resin is EPO provided by Shell Chemical Company.
N (trade name) resin 828, 826, 825 and EPON
HPT resin 1079 can be mentioned. Suitable bisphenols can be represented by the general formula:

[0014]

[Chemical 3]

In the formula, R ^1's are each independently H, Cl, B
r and a C _{1 to} C ₅ alkyl group, Z is a carbon number of about 2
40 divalent groups, which can be aliphatic, cycloaliphatic, aromatic and heterocyclic groups.

Examples of bisphenol include 2,2-bis (4-hydroxyphenyl) propane [bisphenol A], 2,2-bis (4-hydroxy-tert-butylphenyl) propane, 1,1-bis (4 -Hydroxyphenyl)
Ethane, 1.1-bis (4-hydroxyphenyl) isobutane, bis (2-hydroxynaphthyl) methane, 1,5-dihydroxynaphthalene, 1,1-bis (4-hydroxy-3-alkylphenyl) ethane, 9,9- Bis (4-hydroxyphenyl) fluorene, 1,1-bis (4-hydroxyphenyl) indane, 9,9-bis (4-hydroxyphenyl) xanthene, 10,10-bis (4-hydroxyphenyl) anthrone,
Examples include 9,9-bis (4-hydroxyphenyl) phenanthrone.

The bisoxazoline, diepoxide and bisphenol can be mixed in any desired manner such as by melt or solution blending. A preferred technique is to melt the liquid or solid reactant mixture at a temperature above the melting point but below the polymerization temperature of the monomers and stir the melt until it becomes a homogeneous mixture. Typically, the mixture is about 120-180 ° C, preferably about 120-140 ° C.
Stir at a temperature in the range.

Curing is accomplished by heating the mixture to a temperature effective to initiate the reaction between the bisoxazoline, diepoxide and bisphenol functional groups. Generally, the temperature is at least about 140 ° C, preferably about 1
It is maintained within the range of 40 to 180 ° C. for about 2 hours or longer.

The cured bisoxazoline / diepoxide / bisphenol composition is useful as a resin matrix in space and electronics composites. The composition is optional, but preferably contains a reinforcing substrate for high performance applications. Wet or dry lamination techniques can be used for the production of high-grade composites. Typically, continuous filaments of fibrous base material are impregnated with a liquid bisoxazoline / diepoxide / bisphenol mixture. The impregnated filaments are then imparted with dimensional stability by processing techniques such as prepreg, filament wind, wet lay-up, vacuum bag molding, autoclaving and other molding techniques. This resin is then cured and formed into a shaped article. The compositions of the present invention are also suitable for adhesive applications.

For the production of reinforced laminate materials for high-grade composite applications, glass, carbon, quartz, Kevla (Kevla)
r), polyester, polyamide, poly (p-phenylene terephthalamide), polytetrafluoroethylene, poly (p-phenylene benzobisthiazole), boron, paper or paper-like material, in the form of chips, mats or fabrics And preferably bisoxazoline in the molten state /
Impregnated with the diepoxide / bisphenol composition to form a prepreg. A laminate is manufactured by stacking prepregs and subjecting the prepregs to a condition that the resin is cured and the prepreg has a laminated structure. Lamination is generally accomplished by subjecting the prepreg to temperatures of about 140 ° C or higher, preferably 140-350 ° C. Lamination conditions are generally heating for at least 1 hour. The lamination can also be performed under pressure or vacuum conditions. The laminate is optionally effective for improving the thermal properties, typically at least 30 minutes. By heating to a temperature slightly higher than the lamination temperature,
It can be post-cured.

For the production of composites by filament winding, continuous filaments (yarns, rovings or tapes) are wrapped around a mandrel or mold. The fibers are either impregnated with the molten bisoxazoline / diepoxide / bisphenol composition during winding on a mandrel (wet winding) or in the form of prepreg (dry winding). In the winding process, the mandrel generally rotates about a central horizontal axis and the fibers are applied in a pre-defined pattern from a carriage that moves back and forth parallel to the axis of the mandrel. Once the required wall thickness is reached, the bisoxazoline / diepoxide / bisphenol composition is cured, typically by heating in an autoclave or oven at a temperature of about 140-350 ° C or by heating the mandrel. ..

The composition of the present invention contains other additives such as accelerators, fillers, pigments, UV inhibitors, antioxidants, rubber modifiers and other typical additives depending on the desired application. can do.

[0023]

【Example】

Examples 1-5 A series of experiments were conducted to demonstrate the preparation of bisoxazoline / diepoxide / bisphenol compositions according to the present invention. In addition, Examples 1, 4 and 5 are comparative examples in which the crosslink densities are 60, 30, and 10, respectively. 1,3-phenylene
-2,2'-bis (4,5-dihydrooxazole) (PBO),
About 172-178 weight of 2,2-bis (4-hydroxyphenyl) propane and bisphenol-A per epoxy
(BPA) was supplied in the amount shown in Table 1 to a 125 ml filter flask dried under a nitrogen atmosphere. Fourteen flasks
The contents were placed in an oil bath maintained at 0 to 180 ° C. and the contents were vigorously stirred. When the sample was approximately half dissolved, the flask was sealed with a rubber stopper, evacuated to 1 mm Hg and stirred until the sample was completely dissolved and gas evolution ceased.
The hot mixture was then poured into a 1/8 inch glass casting plate that had been preheated to 160 ° C and demolded with silicon. Curing the sample at 180 ° C. for 16 hours,
It was removed from the plate and used for mechanical testing. The toughness (Kq) was measured according to ASTM E-399-83, and the glass transition temperature was measured by a differential scanning calorimeter. The flexural modulus of Example 2 was 42,900 kg / cm ² (610ks
i), the stress was 1,340 kg / cm ² (19 ksi), and the strain was 4%.

As can be seen from Table 2 and FIG. 1, the toughness of the cured bisoxazoline composition is good (ie, about 700 psi in ^{1) at} a crosslink density of 35-60% without a significant decrease in glass transition temperature. ^{/ 2} ). At a crosslink density of 60% as in Example 1, the toughness is significantly reduced compared to Example 2 which has a crosslink density of 50% and a toughness of 92.1 kg / cm ^3/2 (822 psi in ^1/2 ). When the crosslink density is 30% as in Example 4, the crosslink density is 40% and the toughness is 8
Its toughness is considerably reduced compared to Example 3 which has 6.4 kg / cm ^3/2 (771 psi in ^1/2 ).

[0025]

[Table 1]

[0026]

[Table 2]

[Brief description of drawings]

FIG. 1 is a graph showing the relationship between the crosslink density (%) and toughness (Kq) of the composition of the present invention.

Claims (2)

[Claims] 1. Prepared by reacting a mixture containing 10 to 20 mol% diepoxide (a), 40 to 45 mol% bisphenol (b) and 40 to 45 mol% bisoxazoline per mixture. 35
-60% crosslink density and 78.4 kg / cm ^3/2 (700 psi in
A resin composition having a toughness of ^1/2 ) or more. 2. A) impregnating a fibrous base material with a resin mixture containing the following components i) to iii): i) 10 to 20 mol% diepoxide per mixture ii) 40 to 45 mol% per mixture Bisphenol iii) 40-45 mol% bisoxazoline per mixture b) Stabilizing the dimension of the impregnated fibrous substrate, and c) curing the dimensionally stabilized impregnated fibrous substrate with the liquid resin composition. A method for producing a laminated body, which comprises forming a shaped article under effective conditions.