JPH054417B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a polyarylene ester resin composition having high heat resistance, excellent mechanical properties, low mold shrinkage, and good mold release properties. Polyarylene esters are attracting attention as engineering plastics with excellent heat resistance, strength, rigidity, flame retardance, and chemical resistance, especially in applications such as electrical parts and automobile parts. However, in this field, there is a need for a material that has even higher heat resistance, rigidity, and dimensional accuracy (low mold shrinkage) while maintaining the characteristics of the resin, such as flame retardancy, chemical resistance, and electrical properties. This is required in conjunction with technological advances in the field. Generally, resins are supplemented with fibrous reinforcement materials such as glass fibers and carbon fibers, as well as talc, calcium carbonate, magnesium carbonate, calcium sulfite, aluminum hydroxide, mica, molybdenum disulfide, wollastonite, graphite, white titanium, glass beads, etc. It is known that heat resistance, rigidity, and molding shrinkage rate can be improved by blending inorganic fillers in the form of powder, needles, or flakes. When the above-mentioned reinforcing materials and fillers are added to the polyarylene ester resin, improvements in heat resistance and rigidity and reduction in mold shrinkage rate are observed depending on the amount added. The molding shrinkage rate decreases as the amount of the reinforcing material or filler increases, and the mold fidelity in injection molding etc. becomes better, but as the molding shrinkage rate decreases, the mold releasability during injection molding decreases. , it becomes extremely difficult to remove the molded product from the mold. Therefore,
Excessive stress is applied during ejection of the molded product, causing problems such as distortion remaining in the molded product, stress cracks, deformation during ejection, and even breakage. Therefore, although there is a great need for resin compositions that have low mold shrinkage, good mold fidelity, and good dimensional accuracy, they usually do not have problems in releasability from molds. In reality, the amounts of reinforcing materials and fillers blended are limited in order to achieve a molding shrinkage rate that is negligible. As a result of intensive research in view of the above situation, the present inventor has found that by blending wollastonite into polyarylene ester resin and further using a specific amount of fluororesin, it has high heat resistance, rigidity, and strength. It has been discovered that it is possible to obtain a composition having good mold shrinkage, low mold shrinkage, and good mold release properties, and the present invention has been achieved. The present invention contains 20 to 80 wt% polyarylene ester,
Wolastonite 10~70wt%, fluororesin 0.5~
This is a polyarylene ester resin composition characterized by comprising 20 wt%. The polyarylene ester used in the present invention is a polyester synthesized from dihydric phenol or its derivative and aromatic dibasic acid or its derivative. Specifically, the dihydric phenol is represented by the following general formula. In the above, Ar represents an aromatic nucleus such as a phenylene nucleus, a biphenylene nucleus, or a naphthylene nucleus, and R represents a hydrogen atom, an alkyl group (such as a methyl group and an ethyl group), a halogenated alkyl group, or an aryl group (such as a phenyl group and a naphthyl group). , represents a halogenated aryl group, an aralkyl group (e.g. benzyl group and phenylethyl group), a halogenated aralkyl group, an alkyl-substituted aryl group, a halogenated alkyl-substituted aryl group, an alicyclic group or a halogenated alicyclic group, and X is a methylene group. , ethylene group, propylene group, ethylidene group, propylidene group and isopropylidene group: aromatic group, tertiary amino group (-N(alk)
-), ether group (-O-), carbonyl group (-
CO-), or two or more alkylene or alkylidene groups interconnected by sulfur-containing groups, such as sulfide (-S-), sulfoxide (-SO-) or sulfonyl ( _-SO2- ) groups. shows. X may also be an alicyclic group, or a sulfur-containing group, such as a sulfide, sulfoxide or sulfonyl group, an ether group, a carbonyl group or a tertiary amino group. Y is a halogen atom, a nitro group, or R' or OR' (however,
R′ has the same meaning as R mentioned above), m is an integer from O to the number of substitutable hydrogen atoms on X, n is a substitutable hydrogen atom from O to aromatic nucleus Ar p is an integer of at least 1, q is an integer from 0 to 1, and r is an integer (however, when q is 0, r may be 0). In the diphenol shown in the above formula, when there is one or more substituents Y, these substituents may be the same or different. The same is true for R and R'. The substituent Y and the hydroxyl group on the aromatic nucleus may be in the ortho-, meta- or para-position. Alternatively, a mixture of these may be used. Examples of diphenols represented by the above general formula and suitable for carrying out the method of the present invention are as follows. Bis(4-hydroxyphenyl)-methane, bis(4-hydroxy-3-methylphenyl)-methane, bis(4-hydroxy-3,5-dichlorophenyl)-methane, bis(4-hydroxy-3,
5-dibromophenyl)-methane, bis(4-hydroxy-3,5-difluorophenyl)-methane, bis(4-hydroxyphenyl)ketone, bis(4-hydroxyphenyl)-sulfide,
bis(4-hydroxyphenyl)-sulfone,
4,4-dihydroxydiphenyl ether, 1,
1-bis(4-hydroxyphenyl)-ethane,
2,2-bis(4-hydroxyphenyl)-propane, 2,2-bis(hydroxy-3-methylphenyl)-propane, 2,2-bis(4-hydroxy-3-chlorophenyl)-propane, 2,2-bis(4-hydroxyphenyl)-propane
-bis(4-hydroxy-3,5-dichlorophenyl)-propane, 2,2-bis(4-hydroxynaphthyl)-propane, bis(4-hydroxyphenyl)-phenylmethane, bis(4-hydroxyphenyl) )-diphenylmethane, bis(4-
hydroxyphenyl)-4-methylphenylmethane, 1,1-bis(4-hydroxyphenyl)-
2,2,2-trichloroethane, bis(4-hydroxyphenyl)-(4-chlorophenyl)-methane, 1,1-bis(4-hydroxyphenyl)-
Dihydroxynaphthalenes such as cyclohexane, bis(4-hydroxyphenyl)-cyclohexacylmethane, 4,4-dihydroxydiphenyl, 2,2-dihydroxydiphenyl, 2,6-dihydroxynaphthalene, hydroquinone, resorcinol, 2,6-dihydroxy Toluene, 2,6-
Dihydroxychlorobenzene, 3,6-dihydroxytoluene. Specifically, the divalent phenol derivative is a diester of the divalent phenol such as alkyl or phenyl. A mixture of these may also be used. The aromatic dibasic acid is represented by the following general formula. HOOC-Ar'-COOH In the above formula, Ar' represents an arylene group such as o-phenylene group, m-phenylene group, p-phenylene group and naphthylene group, and these arylene groups are substituted with an alkyl group or a halogen atom. It's okay. A mixture of these may also be used. The derivatives of aromatic dibasic acids are dichlorides or diesters of alkyl, phenyl, etc. of the aromatic dibasic acids. A mixture of these may also be used. The derivatives of aromatic dibasic acids are dichlorides or diesters of alkyl, phenyl, etc. of the aromatic dibasic acids. A mixture of these may also be used. The polyarylene ester used as a component of the composition of the present invention is prepared by combining the above-mentioned dihydric phenol or its derivative and the above-mentioned aromatic dibasic acid or its derivative by interfacial polycondensation method, solution polycondensation method, melt polycondensation method, etc. Synthesized using any method. A preferred polyarylene ester is bisphenol A (2,2-bis(4-hydroxyphenyl)
-propane) residue, terephthalic acid residue, and isophthalic acid residue. This is marketed as "U Polymer" by Unitika Co., Ltd. Wollastonite is used as the inorganic filler used as a component of the composition of the present invention. Wollastonite can normally be used without any treatment, but in order to make it compatible with polyarylene ester, silane coupling agents such as aminosilane and epoxysilane, chromic chloride, and other surface treatment agents are used depending on the purpose. can do. The fluororesin used as a component of the composition of the present invention refers to a synthetic polymer containing fluorine atoms (F) in the molecule, examples of which include tetrafluoroethylene resin, tetrafluoroethylene resin, Examples include perfluoroalkyl vinyl ether copolymer resin, tetrafluoroethylene-hexafluoride propylene copolymer resin, tetrafluoroethylene-ethylene copolymer resin, trifluorochloride ethylene resin, vinylidene fluoride resin, and the like. Among the fluororesins mentioned above, tetrafluoroethylene resin (polytetrafluoroethylene) has a melting point of approximately 330°C.
However, it has a high melt viscosity and does not flow even above the melting point. Therefore, it is preferable because the dispersion state in the composition does not change easily depending on the molding processing conditions, and the properties, mechanical strength, and mold releasability during injection molding of the composition do not change easily. The blending amount is polyarylene ester 20~
80wt%, wollastonite 10-70wt%, fluororesin 0.5-20wt% (the total amount of wollastonite and fluororesin is 20-80wt% of the total resin composition)
%) is effective. In other words, when the total amount of wollastonite and fluororesin exceeds 80 wt% in the resin composition and the amount of polyarylene ester is less than 20 wt%, mixing is insufficient and a uniform composition cannot be obtained. First, the fluidity of the resin composition is lost, making molding difficult.
In addition, the total amount of wollastonite and fluororesin
If it is less than 20wt%, a sufficient molding shrinkage reduction effect cannot be obtained. Furthermore, even if the total amount of the reinforcing material or filler and fluororesin is 20 to 80 wt%, if the amount of wollastonite is less than 10 wt%, the effect of reducing the molding shrinkage rate is insufficient, and vice versa. The amount of fluororesin in
If it is less than 0.5 wt%, mold releasability during injection molding etc. will not be sufficient. In addition, when wollastonite exceeds 70wt%,
Mixing becomes insufficient, the compounding process becomes difficult, and a uniform composition cannot be obtained. If the amount of fluororesin exceeds 20 wt%, the strength of the obtained molded product will decrease significantly, which is not preferable. The means of blending the composition of the present invention is not particularly limited. It is possible to feed polyarylene ester, wollastonite, and fluororesin separately to a melt mixer, and these raw materials can be added in advance to a mortar, Henschel mixer, ball mill,
It is also possible to pre-mix using a ribbon blender or the like and then supply it to the melt mixer. The composition of the present invention may contain antioxidants, heat stabilizers, ultraviolet absorbers, lubricants, mold release agents, colorants such as dyes and pigments, flame retardants, One or more conventional additives such as flame retardant aids and antistatic agents can be added. In addition, other thermoplastic resins (for example, polyethylene, polypropylene, polyamide, polycarbonate, polyester carbonate, polyethylene terephthalate, polybutylene terephthalate, polysulfone, polyether sulfone, modified polyphenylene oxide, acrylonitrile-
Styrene-butadiene resin (ABS resin), polyphenylene sulfide resin, etc.), thermosetting resin (for example, phenol resin, epoxy resin, etc.) can be blended depending on the purpose. In particular, polycarbonate, polyester carbonate, polyethylene terephthalate, and polybutylene terephthalate are preferred because they have good compatibility with the polyarylene ester and have excellent improving effects such as improved processability. Further, polyamides such as nylon 6 and nylon 66 are preferable because they improve the processability of the polyarylene ester and improve chemical resistance. Hereinafter, the present invention will be specifically explained with reference to Examples, but these are illustrative of preferred embodiments and are not limited to the compositions of Examples. Examples 1 to 5 Polyarylene ester having the following structure as the main structure (manufactured by Unitika Co., Ltd., U-Polymer U-100) (However, m/n = approximately 5/5), wollastonite (NYAD-G manufactured by Nagase Sangyo, CaSiO ₃ needles) and tetrafluoroethylene resin (Fluon L169 manufactured by ICI) in the composition shown in Table 1. After melt-kneading at a temperature of 340° C. using a twin-screw extruder (PCM-30 manufactured by Ikegai Iron Works), the strands were water-cooled and cut to obtain pellets. The obtained pellets were injection molded (Sumitomo-Nestal 47/28 injection molding machine, cylinder temperature 360℃,
A bending test piece was molded using a mold temperature of 180°C.
After opening the mold, the resistance when ejecting the molded product with an ejector pin was measured using a strain gauge type pressure sensor. Further, using the obtained bending test piece, bending strength, bending elastic modulus, heat deformation temperature, and molding shrinkage rate were measured. Bending strength is ASTM D-790, heat distortion temperature is
Measured in accordance with ASTM D-648 (18.6 Kg/cm ² ). The results are shown in Table 1. Comparative Examples 1 to 5 The polyarylene ester and wollastonite tetrafluoroethylene resin used in Examples 1 to 5 were
They were mixed in the proportions shown in the table, processed in the same manner as in Examples 1 to 5, and measured for physical properties. The results are shown in Table 1.

【table】

[Table] It can be seen that the composition of the present invention has improved heat resistance and rigidity (modulus of elasticity) of polyarylene ester, high strength, low mold shrinkage rate, and good mold release properties (Examples 1 to 3). 5). In addition, in compositions other than the composition of the present invention, the improvement in molding shrinkage rate was not sufficient (Comparative Example 2),
It does not have the desired good properties, such as a large decrease in strength (Comparative Example 4) and insufficient mold releasability (Comparative Example 5).

Claims (1)

[Claims] 1 Polyarylene ester 20-80wt%, wollastonite 10-70wt% and fluororesin 0.5-80wt%
A polyarylene ester resin composition comprising 20wt%.