JPS62263218A - Epoxy resin composition - Google Patents

Abstract

PURPOSE:To provide the titled composition with body and low specific gravity, outstanding in processing accuracy, dimensional stability and heat resistance, comprising an epoxy resin, curing agent made up of specific amine compound, and microballoons of low specific gravity. CONSTITUTION:The objective composition comprising (A) an epoxy resin, (B) a curing agent made up of an amine compound of formula [R is H or 1-3C alkyl (where, H accounting for <=50mol% in the whole aniline skeleton), X is H or 1-3C alkyl, n is 1-5], and (C) pref. 5-30wt% of microballoons with a specific gravity 0.05-0.6 (pref. 0.15-0.4).

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to epoxy resin compositions.

[Conventional technology]

Traditionally, in the vehicle industry, electrical industry, etc., epoxy resins, hollow microspheres, and epoxy resins made of hardening agents such as diethylenetriamine have been used as various model materials that require dimensional accuracy, such as master models, copy models, and preservation models that serve as the basis for molded products. There are resin compositions.

[Problems to be Solved by the Invention] However, the molded products of conventional epoxy resin compositions are hard and brittle, so there are problems with processing accuracy such as easy chipping of edges.

[Means for solving problems]

The present inventor has arrived at the present invention as a result of repeated studies on epoxy resin compositions with good processing accuracy.

That is, the present invention provides an epoxy resin (A) with the general formula [wherein R is H or an alkyl group having 1 to 3 carbon atoms (however, H is 50 mol% or less of the total aniline skeleton), and X is H1
A curing agent CB consisting of an amine compound (hereinafter abbreviated as AF amine) represented by an alkyl group having 1 to 3 carbon atoms, where n represents 1 to 5; and hollow microspheres with a specific gravity of 0.05 to 0.6 ( C) It is a drying epoxy resin composition.

In the general formula (1), the alkyl group having 1 to 3 carbon atoms for R is a methyl group, an ethyl group, an n-propyl group and an i-
Examples include propyl group. Among these, preferred are methyl and ethyl groups. When the carbon of R is a prime number of 4 or more, the heat resistance of the molded product becomes low. R that exists multiple times
is not limited to one type, and two or more types may be mixed.H in R is 50 mol% or less, preferably 30 mol% or less in the total aniline skeleton. If the amount of the primary aniline skeleton is more than 50 mol % when R is H, the molded product will be hard and brittle, and edges will be easily chipped.

In general formula (1), the alkyl group having 1 to 3 carbon atoms in X includes methyl group, ethyl group, n-propyl group, and i
-propyl group.

Among these, preferred are H1 methyl group and ethyl group. In the general formula (1), the plurality of Xs is not limited to one type, and two or more types may be mixed.

In general formula (1), n is preferably 1-4. n
When n is less than 1, the heat resistance decreases, and when n is more than 5, the heat resistance improves, but the material becomes hard and brittle, and edges are easily chipped.

As a specific example of AP thiamine represented by general formula (1),
For example, AF aniline, in which each symbol in general formula (1) is shown in Table 1, can be mentioned.

Table 1 AF aniline known methods, such as N- having 1 to 3 carbon atoms
Furkylaniline or its alkyl nuclear substituted product or N
- It can be obtained by condensing a mixture of furkylaniline or its alkyl substituted product with formaldehyde under acidic conditions, but this method is not limited to this method. After condensing primary aniline with formaldehyde, it can be N-alkylated. Alternatively, the condensed aromatic hydrocarbon may be nitrated, reduced, and further N-alkylated, AF
A single compound in which aniline n is an integer may be used, but from the viewpoint of compatibility with the epoxy resin, it is better to use a mixture of various single compounds. Preferably, the compound where n=O is 0 to 30%, and n=
1 is 10-60%, n = 2 is 10-50%, n = 3
-5 is about 0 to 40%, and n=6 or more is about 0 to 30%. AF anilines obtained by condensation of N-alkylanilines and formaldehyde under acidic conditions are usually such mixtures. The value of n can be determined by n=(23'-'')/(ry) when A-F amine is prepared from X moles of N-methylaniline and y moles of formaldehyde.

The epoxy resin (A) in the present invention may be any ordinary one, such as (1) phenol ether epoxy resin [condensate of bisphenols and epichlorohydrin, condensate of novolak phenol resin and epichlorohydrin, etc.], (2) Ether-based epoxy resins (e.g., condensates of polyols, polyether polyols, etc. and epichlorohydrin), (3) Ester-based epoxy silanes (e.g., glycidyl methacrylate, ster and ethylenic double bond monomers (acrylonitrile, etc.)), (4) Glycidyl-type epoxy resins such as glycidylamine-based epoxy resins [condensates of amines and epichlorohydrin, etc.]; and non-glycidyl-type epoxy resins such as cyclic epoxy resins, epoxidized polybutadiene, and epoxidized soybean oil. epoxy resins and mixtures of two or more of the above epoxy resins. For details on epoxy resins, please refer to "Basic Chemistry of Synthetic Resins (New Edition)" (1932).
0th edition) written by Tadahiro Miba, published by Gihodo, pages 371-392.

Among the epoxy resins, preferred are phenol ether epoxy resins and glycidylamine epoxy resins.

Hollow microspheres ((') in the present invention include (1) inorganic hollow microspheres (hollow microspheres made from glass, whitebait, etc.), (2) organic microballoons (thermosetting resins such as phenolic resin and epoxy resin). Hollow microspheres made from resin or thermoplastic resin such as acrylonitrile-vinylidene chloride copolymer]. Preferred among hollow microspheres are hollow microspheres made from glass;
and hollow microspheres made from phenolic resin.

The specific gravity of the hollow microspheres is usually 0.05 to 0.6, preferably 0.15 to 0.4. If the specific gravity is less than 0.05, the microspheres will separate in the epoxy resin composition, making it difficult to obtain a uniformly dispersed molded product.

If it is larger than 0.6, the lightweight effect cannot be sufficiently exhibited.The particle size of the hollow microspheres is usually 5 to 300μ, preferably 10 to 300μ.
If the zero particle size (180μ) is smaller than 5μ, the fluidity during molding will decrease, and the mechanical strength of the resulting molded product will tend to decrease; if it is larger than 300μ, the microspheres will separate, resulting in a uniformly dispersed molding. It's hard to get things.

In the composition of the present invention, the amount of curing agent CB/) is usually 0.5 to 1.5 in terms of active hydrogen per equivalent of epoxy resin.
Preferably the ratio is 0.8 to 1.2. If the active hydrogen equivalent ratio of the curing agent is less than 0.5, or if i is greater than 1.5, the heat resistance of the molded product will decrease.

The content of the hollow microspheres (C) is usually 5 to 30%, preferably 7 to 20%, based on the weight of the composition. If the blending amount of (C) is less than 5%, the lightening effect is sufficiently exhibited, but if the flaw is greater than 1.30%, the fluidity of the epoxy resin composition during molding is reduced.

In the composition of the present invention, the curing agent may contain other curing agents for epoxy resins, if necessary.

For example, amine curing agents (aliphatic amines (triethylenetetramine, tetraethylenepentamine, etc.), polyamide 7mine (condensate of dimer acid and polyamine), aromatic amines (4,4'-diaminodiphenylsulfone,
．． 4'-diaminodiphenylmethane, N,N'-dimethyl-44I-diaminodiphenylmethane, N,N'-
diethyl-4,4'-diaminodiphenylmethane, N,
(N'-dimethyl-3,3'-diaminodiphenylmethane, etc.)), 7z-nol curing agents (bisphenols (bisphenol A1, bisphenol F1, bisphenol S, etc.), phenolic resins (novolak phenol resin, novolak cresol resin), vinyl phenol (bo'J-P-vinylphenol, etc.)).

The amount of other curing agents for epoxy resins is usually 0 to 50% based on the weight of the total curing agent from the viewpoint of heat resistance, processability, and dimensional stability.
, preferably from ( ) to 30%. When using the composition of the present invention, reactive diluents such as olefin oxide, glycidyl methacrylate, styrene oxide, phenyl glycidyl ether, and phenyls/-ols may be added as necessary. 1. Curing accelerators such as tertiary amines, imidazoles, amino) IJ azoles,
Fillers such as silica powder, aluminum powder, mica, calcium carbonate, and wood flour, coupling agents such as epoxy silane and amino silane, and coloring agents such as inorganic pigments and organic pigments may be added.The amount of these used depends on the epoxy resin. Based on the total weight of the curing agent and curing agent, typically 0 to 15% reactive diluent, 0 to 5% accelerator, 0 to 10% filler, 0 to 1% coupling agent, and 0 to 5% colorant. be.

The curing temperature of the composition of the present invention is usually 50 to 200°C, preferably 70 to 180°C. Curing time is usually 0.5~
15 hours, preferably 1 to 10 hours.

〔Example〕

Hereinafter, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited thereto. Among the Examples and Comparative Examples,
Parts indicate parts by weight.

In the Examples and Comparative Examples, the curing agent I-1 listed in Table 1 was used. The analytical values for curing agents 1 to 3 are shown in Table 2.

Table-2 Note that the method for producing the curing agent is as follows.

1/In a flask, N-methyl or N-ethylaniline or N-ethyltoluidine (3 moles) and 36%
Hydrochloric acid (3 mol) was charged, and 37% formaldehyde aqueous solution (2 mol) was added dropwise from the dropping funnel over 1 hour while maintaining the liquid temperature at 30 to 40°C. After stirring at 30-40°C for 2 hours, the temperature was raised to 90-95°C and stirred for an additional 2 hours. The reaction solution was cooled to room temperature and neutralized with a 48% aqueous sodium hydroxide solution (3.15 mol). After 1. toluene 300c
The condensate was extracted with c, and the toluene layer was diluted with 4 IUOcc of water.
Washed twice. Toluene was distilled off at 160° C. under reduced pressure (13 mm HP) to obtain a curing agent.

Examples 1 to 3, Comparative Example 1.2 Compositions of the present invention (Examples 1 to 3) and comparative products (Comparative Examples 1 and 2) are shown in Table-1.

Test Example 1 The compositions of the present invention (Examples 1 to 3) were uniformly mixed and devoured at 80°C for 10 minutes, then poured into a mold, and heated at 90°C.
, cured for 2 hours + 160°C x 2 hours,
cfnX 11) c! A molded product of nX 5- was obtained.

In addition, comparative products (Comparative Examples 1 and 2) were uniformly mixed and devoured at 25°C for 10 minutes, and then poured into a mold.
Cured under 24 hour conditions, 20cmX I Qcmx
A molded product of 5 crn was obtained.

Test pieces were cut out from the molded products obtained from the compositions of Examples 1 to 3 and Comparative Example 1.2, and the specific gravity, bending and compressive strength,
Thermal deformation temperature, coefficient of linear expansion, water absorption, hardness, and workability were investigated.

The results are shown in Table-3.

Table 3 (Note) 5 Specific gravity: Petsukuman air comparison type hydrometer, the smaller the value, the lighter it is.

(Note) 6 Bending strength, compressive strength: The larger the JIS K6911 value, the stronger it is against mechanical stress.

(Note) 7 Heat distortion temperature: ASTM D 648 The larger the value, the better the heat resistance.

(Note) 8 Linear expansion coefficient: TMA method, the smaller the value, the better the dimensional stability against temperature changes.

(Note) 9 Water absorption rate: The smaller the JISK6911 value, the better the dimensional stability under humid conditions).

(Note) 10 Hardness: ASTM D-2
When the 240 value is large, the tool is hard, and the tool blade is likely to chip and become severely damaged.

If the value is small, cutting with a tool will be difficult and machining accuracy will deteriorate. 50-70 is good.

(Note) 11 Workability: Cutting and drilling were performed using a plane and a drill press. The case where the chips were connected was rated as 0, and the case where the chips became powder was rated as ×.

When the chips are connected, the edges of the cutting surface become sharp and the machining accuracy is good.

〔Effect of the invention〕

The composition of the present invention provides molded articles with the following properties.

(1) It is soft and can be easily cut into cylinders, and has good workability (manual and machine workability).

(2) It is sticky, has good processing accuracy, and has no problems such as easy chipping of edges.

(3) Good dimensional stability.

(4) Good heat resistance.

(5) It is a lightweight epoxy resin composition that has a low specific gravity and therefore provides a lightweight molded product.

The above properties (particularly (1/) to (4)) were insufficient in the case of conventional compositions using curing agents such as diethylenetriamine, but these properties do not exist in the case of the composition of the present invention. It should be completely satisfying.

The composition of the present invention can be used as a material suitable for applications that require processing accuracy, dimensional stability, hand and machinability, and heat resistance, such as master models, copy models, and storage models that serve as the basis for molded products. Can be done.

Claims (1)

[Claims] 1. Epoxy resin (A), general formula ▲ Numerical formula, chemical formula, table, etc. ▼ (I) [In the formula, R is H or an alkyl group having 1 to 3 carbon atoms (however, H is (50 mol% or less of the total aniline skeleton), X represents H or an alkyl group having 1 to 3 carbon atoms, and n represents 1 to 5. ] An epoxy resin composition comprising a curing agent (B) consisting of an amine compound represented by the following formula and hollow microspheres (C) having a specific gravity of 0.05 to 0.6. 2. The composition according to claim 1, wherein the content of (C) is 5 to 30% based on the weight of the composition.