JPH0735469B2 - Molding polymerizable composition containing polymer particles - Google Patents

Description

TECHNICAL FIELD The present invention relates to a novel molding polymerizable composition. More specifically, by using an epoxy resin as a base material and depositing and dispersing fine particles of wholly aromatic polyamide in this base material, there is little radical reaction heat generation during the polymerization (curing) reaction in reaction injection molding (RIM), etc. The present invention also relates to a novel molding polymer composition having improved characteristics such as molding shrinkage, dispersion stability of compounding agents (fine particles), flow characteristics, and homogeneity of molded articles.

[Prior art] RIM (Reaction Injection Molding, that is, reaction injection molding), RTM (Resin Transfer Molding, that is, resin transfer molding), Cast molding (that is, cast molding)
Molding methods for resin molded products and composite materials, which are referred to as "etc.", have been known per se for a long time, but these are plastics utilizing the advantage of using a relatively low-viscosity polymerizable liquid composition as a raw material for molding. As an energy-saving molding method for large-scale members and composite materials of plastics, it has recently attracted particular attention (see, for example, "Thermosetting Resin" Vol. 7, NO., 2, p87-98).

Epoxy resin (epoxy curing system) is known as a typical resin used for such RIM and RTM.

When molding an epoxy resin, conventionally, a curing agent is added to a liquid epoxy monomer (or prepolymer), and if necessary, a curing accelerator, a polymerization catalyst, a polymerization accelerator, an inhibitor, a chain transfer agent, A sensitizer, a release agent, a rubber component, etc. are added and mixed in a one-, two-, or three-component type composition, and the mixture is directly subjected to molding in a liquid monomer (or prepolymer) state. For the purpose of improving various physical properties such as heat resistance, mechanical properties, and surface properties of the product, for example, an inorganic filler such as calcium carbonate powder or glass short fiber is blended.

However, many of the above-mentioned inorganic fillers have a large specific gravity and are effective in the case of a relatively high-viscosity epoxy resin, but the resin liquid (monomer or oligomer) is relatively large in the mold such as RIM. In the case of the molding method in which the viscosity is low, the filler gradually settles and the filler is unevenly distributed in the resin before curing, so that the upper and lower parts of the molded product have thermal and mechanical properties. There was a difficulty that they were different. Particularly, in the case of a large-sized molded product whose curing time is intentionally delayed, ensuring homogeneity is an important technical issue.
Further, since the filler is settled and unevenly distributed in the molded product, there is a problem that an extreme heat is easily generated locally during curing. In addition, the inclusion of the inorganic filler increases the specific gravity of the molded product and impairs the lightweight property which is an advantage of the composite material.

[Problems to be Solved by the Invention] The present invention solves the above-mentioned problems in a conventional epoxy-based polymerizable composition containing an inorganic filler,
Provided is a novel molding polymerizable composition containing a special organic filler capable of reducing the local heat generation during the curing reaction and preferably improving the homogeneity, surface property and dimensional stability of the molded product. The purpose is to do.

[Means for Solving the Problems] According to the present invention, the above-mentioned object is for molding, which comprises a liquid epoxy resin composition (A) and wholly aromatic polyamide fine particles (B) suspended therein. A composition, and
A wholly aromatic polyamide fine particle (B) is prepared by a polymerization reaction in the epoxy resin composition (A) and is deposited in the epoxy resin. It

The present invention relates to a suspension composition consisting essentially of an epoxy resin composition (A) that can be cured to form a resin without substantially generating volatile components and fine particles (B) of wholly aromatic polyamide. However, in the present invention, in the epoxy resin composition (A), the monomer component of the wholly aromatic polyamide that is the filler, that is, the aromatic diamine and the aromatic dicarboxylic acid chloride are polycondensed. By forming a polymer and precipitating it as fine particles (B), the finely divided particles (B) of wholly aromatic polyamide are uniformly suspended and dispersed in the epoxy resin (A) of the substrate. A polymerizable composition is formed. Therefore, here, the epoxy resin (A) is a basic resin and at the same time serves as a polymerization solvent (reaction medium) for the wholly aromatic polyamide.

Hereinafter, the above (A) and (B) will be described in detail.

Epoxy resin composition (A) As the epoxy resin composition (A) component, a composition mainly containing a liquid epoxy monomer and / or a prepolymer is used. Such a composition consists essentially of an epoxy monomer and / or prepolymer, a curing agent and a catalyst for curing the same, and curing (polymerization) and shaping without substantially releasing volatile components in the molding step. An epoxy resin composition is used which is capable of simultaneously performing (molding) in a relatively short time and which is substantially liquid at the molding temperature.

As such an epoxy monomer, various glycidyl ethers and / or glycidyl esters are used, and as a particularly preferable example of the epoxy monomer, bisphenol A is used.
Examples thereof include glycidyl ether and phenol novolac glycidyl ether. Further, as the curing agent, phenylenediamines as shown in Examples below are preferable.

About wholly aromatic polyamide fine particles (B) As is well known, wholly aromatic polyamide is a heat-resistant thermoplastic polymer obtained by reacting an aromatic diamine with an aromatic dicarboxylic acid chloride. Then, this polycondensation reaction is carried out in an epoxy resin composition, and wholly aromatic polyamide is deposited as fine particles in the composition.

Although hydrogen chloride is generated as a by-product in the above reaction,
When the removal is difficult due to the possibility of corrosion of the equipment material, for example, by reacting propylene oxide to produce chlorohydrin, and changing it to another compound that can be distilled off, it is distilled under reduced pressure. It is possible to leave it.

Examples of the monomer used for producing the wholly aromatic polyamide fine particles (B) include the following aromatic diamines and aromatic dicarboxylic acid chlorides.

(A) aromatic diamine (i) para-type (coaxial, parallel axis) para-phenylenediamine (and one or more lower alkyl group, lower alkoxy group, halogeno group in its aromatic ring,
Those containing non-reactive functional groups such as lower carboalcooxy groups and nitro groups; the same applies hereinafter), benzidine, 4,4'-diamine-para-phenyl, 2,7-diaminefluorenone, 2,8- Diamine phenoxatin, 1,4-, 1,5- or 2,6-naphthylene diamine and the like.

(Ii) non-para-metaphenylenediamine (and one or more lower alkyl group, lower alkoxy group, halogeno group in its aromatic ring,
Those containing non-reactive functional groups such as lower carboalkoxy groups and nitro groups; the same applies hereinafter), diamines in which two or more phenylene groups are bonded with one or more atoms; (In the above formula, X is a divalent group, for example, -O.
-, -S-, -SO-, etc.) Specifically, 3,3-, 3,4'- or 4,4'-diaminodiphenyl ether, 3,3-, 3,4'- or 4, 4'-diaminodiphenyl thioether, 3,3-, 3,4'- or 4,4'-
Diaminophenylmethane, 3,3-, 3,4'- or 4,4'-
Diaminophenyl sulfone, 3,3-, 3,4'- or 4,4 '
-Benzophenonediamine and the like.

(B) Aromatic dicarboxylic acid chloride (i) Para type (coaxial, parallel axis) terephthalic acid dichloride (and one or more lower alkyl group, lower alcooxy group, halogen group, lower carboalcooxy group in its aromatic ring) , Those containing non-reactive functional groups such as nitro groups; the same shall apply hereinafter), 4,4'-dibenzoyl chloride, 1,5- or 2,6-naphthylene dicarboxylic acid dichloride, 2,5-pyridylene dicarboxylic acid Acid dichloride, dichloride of 4,8-quinolinedicarboxylic acid,
Dichloride of 4,4′-stilbene dicarboxylic acid, 4,4 ′
-Such as dichloride of azoxybenzenedicarboxylic acid.

(Ii) non-para type isophthalic acid dichloride, (one or more lower alkyl group, lower alkoxy group, halogeno group in its aromatic ring,
Those containing non-reactive functional groups such as lower carboaroxy groups and nitro groups; the same shall apply hereinafter), 4,4'-oxydibenzoyl chloride, 3,4'-oxydibenzoyl chloride, 3,3'-oxy Dibenzoyl chloride, 4,4'-sulfonyldibenzoyl chloride, 3,4'-sulfonylbenzoyl chloride, 3,3'-sulfonyldibenzoyl chloride, 4,4'-benzophenone dicarboxylic acid chloride, 3,3'-di Benzoyl chloride etc.

Diacid chlorides in which two phenylene groups are bonded by one atom; eg 3,3-, 3,4'- or 4,4'-dichloroformyldiphenyl ether, 3,3-, 3,4'- or 4,4 ′
-Dichloroformyl diphenyl thioether, 3,3-,
3,4'- or 4,4'-dichloroformyldiphenylmethane, 3,3-, 3,4'- or 4,4'-dichloroformyldiphenylsulfone, 3,3-, 3,4'- or 4,4 ′ -Benzophenone didicarboxylic acid dichloride and the like.

In the present invention, the wholly aromatic polyamide polymer fine particles (B) are prepared by polymerizing the above-mentioned monomers (a) and (b) in the epoxy resin composition (A). The polymerization reaction condition is not particularly limited as long as it is a reaction condition that allows polymerization in the epoxy resin composition (A). However, when the reaction requires a high temperature and the fluidity of the epoxy resin composition (A) is substantially impaired, the reaction temperature is reduced by the selection of a highly active catalyst or a highly reactive monomer, and the polymerization of the epoxy resin is prohibited. It is necessary to take measures such as adding agents.

As described above in part, in the present invention, the precipitation of fine particles often occurs during the process of polymerization of aromatic polyamide in the epoxy resin composition (A), but the precipitation of wholly aromatic polyamide fine particles (B) occurs. At this point, by applying a shearing force by stirring or the like, it is possible to change the form, size, etc. of the fine particles (B) that precipitate. For example, when the fine particles (B) precipitate extremely slowly, the gel may have poor fluidity without stirring. However, by precipitating with stirring, a suspension having relatively good fluidity can be obtained. It is possible to prepare. It is also possible to add solid wholly aromatic polyamide particles produced in advance as a so-called "nucleus" for the purpose of promoting precipitation, if necessary.

The size and morphology of the fine particles (B) in the suspension composition of the present invention affect various physical properties (and moldability) of the molded product finally obtained by the curing reaction. As described above, in addition to the shearing force at the time of precipitation, the polymer concentration, the temperature at the time of precipitation, and the size / morphology / amount of the “nucleus” added as necessary are the main factors that control the size / morphology of the fine particles (B). Is.

The size of the fine particles (B) to be precipitated is preferably 0.1 μm.
m or less, and preferably 0.01 μm or less depending on the purpose of use.

In the present invention, when the wholly aromatic polyamide fine particles (B) are produced and precipitated by polycondensation, the by-produced condensate may foam during curing or may remain in the molded product after molding, impairing the performance. In such a case, its removal is necessary. That is, hydrogen chloride is generated by polycondensation during the production of wholly aromatic polyamide, but since it has a relatively strong corrosive property, it is preferable to distill it off in the form of chlorohydrin with propylene oxide.

The amount of wholly aromatic polyamide fine particles (B) in the molding composition according to the present invention is the same as that of the epoxy resin (A) and (B).
Is selected according to the type of wholly aromatic polyamide, the properties required for the molded product, etc. In general, (B) is (A)
A range of 0.5 to 50 parts by weight per 100 parts by weight is preferable.

Curing of the composition comprising (A) and (B) of the present invention: The composition of the present invention prepared as described above is combined with an appropriate curing agent / catalyst to release substantially volatile components in the molding process. The curing (polymerization) and the shaping (molding) of the epoxy resin can be performed simultaneously (in a relatively short time) without performing the above.

As the curing agent / catalyst, amines, acid anhydrides, imidazoles and various cationic catalysts can be used, and as the curing agent, phenylenediamines as shown in Examples below are particularly preferable.

[Effects of the Invention] The resin molded product obtained from the polymerizable composition for molding of the present invention having the above-mentioned constitution has a low specific gravity as compared with the case where an inorganic filler is used, and the composition is liquid. There is little sedimentation during storage at the time of injection / filling into a mold, etc., so there is little local heat generation during curing. Furthermore, the physical and chemical affinity with the resin obtained by the curing reaction of the liquid epoxy monomer
Since it is excellent in reactivity, the molding shrinkage is small as compared with the case where such a filler is not mixed, and the polymerized (cured) molded product exhibits excellent heat resistance and mechanical properties.

[Examples] Hereinafter, the present invention will be described in detail with reference to Examples.

The abbreviations shown in the examples (including tables) mean the following compounds, respectively.

BSA-GLY; Bisphenol A diglycidyl ether FNV-GLY; Phenol novolac glycidyl ether PPDA; Paraphenylenediamine MPDA; Metaphenylenediamine PPDA-Si; Bistrimethylsilyl paraphenylenediamine MPDA-Si; Bistrimethylsilylmetaphenylenediamine TPC; Terephthalic acid chloride IPC; Isophthalic acid chloride Examples 1 to 5 Phenylenediamine (or its derivative) shown in the following table was dissolved in BSA-GLY (bisphenol A diglycidyl ether; epoxy value = 190). On the other hand, aromatic dicarboxylic acid chlorides shown in the table below were dissolved or dispersed in FNV-GLY (phenol novolac glycidyl ether; epoxy value = 174) having a low water content.

The following two methods were used for mixing the monomers.

Liquid solid: Amine solution is mixed with finely pulverized powder of aromatic dicarboxylic acid chloride and stirred. (Examples 1, 4, 5).

Liquid-liquid: The above two solutions are mixed and stirred. (Example 2,
3).

Each composition obtained was a molding polymerizable composition in which a predetermined amount of wholly aromatic polyamide polymer fine particles were suspended in an epoxy monomer. Acetone was added to this composition, the epoxy monomer was eluted, and the composition was thoroughly washed, and the intrinsic viscosity (ηinh) of the precipitated wholly aromatic polyamide polymer was measured. The results are shown in the rightmost column of the above table.

When this composition was injection molded by a conventional method, the liquid stability during storage and the injection moldability were good, and the heat generation during curing was small. In addition, the physical properties of the obtained molded product were also excellent.

Claims (2)

[Claims] 1. A molding composition comprising a liquid epoxy resin composition (A) and wholly aromatic polyamide fine particles (B) suspended therein, wherein the wholly aromatic polyamide fine particles ( A polymerizable composition for molding, characterized in that B) is prepared by a polymerization reaction in the epoxy resin composition (A) and deposited in the epoxy resin. 2. The polymerizable composition for molding according to claim 1, which contains phenylenediamine as a curing agent in the epoxy resin composition (A).