JPH0481451A - Liquid crystal polyester resin composition - Google Patents

Abstract

PURPOSE:To obtain the subject composition having excellent heat-resistance, moldability and fluidity, giving a molded article having high mechanical strength and small mechanical anisotropy and suitable for electrical and electronic parts, etc., by compounding a liquid crystal polyester with a specific amount of a flaky or granular filler having a specific free water percentage. CONSTITUTION:The objective composition is produced by compounding (A) 100 pts. wt. of a liquid crystal polyester containing ethylenedioxy unit as essential component and having a melting point of 280-350 deg.C and a melt viscosity of 10-15,000 poise and (B) 1-200 pts.wt. (preferably 20-150 pts.wt.) of a flaky or granular filler (e.g. calcium silicate and calcium phosphate) having a free water percentage of >0.l5% (preferably >=0.2%) after drying the filler to a free water percentage of <=0.15% (preferably <=0.1%).

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention provides a liquid crystal polyester resin composition that has excellent heat resistance, moldability, and fluidity, has high mechanical strength in molded products, and has low mechanical anisotropy. It is related to.

<Conventional technology> In recent years, the demand for higher performance plastics has been increasing, and many polymers with various new performances have been developed and put on the market. Optically anisotropic liquid crystalline polyesters have attracted attention because of their excellent mechanical properties.

However, this liquid crystal polyester is known to have large mechanical anisotropy and low mechanical strength perpendicular to the flow direction, and it is also known that the anisotropy can be reduced by adding fillers. .

<Problems to be Solved by the Invention> However, resin compositions in which liquid crystal polyester is filled with plate-like or granular fillers, which are known to be effective fillers for reducing orientation, often have poor mechanical strength. was found to decrease significantly.

Therefore, it is an object of the present invention to solve the above-mentioned problems and to obtain a liquid crystal polyester resin composition that has excellent heat resistance, moldability, and fluidity, has high mechanical strength of molded products, and has low mechanical anisotropy. shall be.

<Means for Solving the Problems> That is, the present invention provides: (1) 1 to 200 parts by weight of a plate-shaped or granular filler having an attached moisture content of more than 0.15% with respect to 100 parts by weight of liquid crystal polyester (A); A liquid crystal polyester resin composition, which is filled after being dried to an adhering moisture content of 0.15% or less.

(2) The present invention provides a liquid crystal polyester resin composition according to claim (1), wherein the liquid crystal polyester contains an ethylenedioxy unit as an essential component.

The liquid crystal polyester referred to in the present invention is a polyester consisting of units selected from aromatic oxycarbonyl units, aromatic dioxy units, aromatic dicarbonyl units, ethylenedioxy units, etc., and preferably contains ethylenedioxy units as an essential component. It is a polyester selected from the following structural units (I) to (IV).

→○−R1−0+− +0CH2CH20+ 1+C0−R2−C0+ ...(II) ...(III) ...(IV) H3, R2 is selected from Indicates one or more groups. In addition, the structural unit (I
V) is substantially equimolar to the structural unit [(, I[) + (1) ]. ) Among these, polyesters consisting of (I) to (IV) are most preferred, and R1 is also a monoester.

Among the above structural units (I) to (IV), the structural unit [(I) + (I[l) ] is [(1) + (II>+
(III)] is 75 to 95 mol%, preferably 82 to 92 mol%, and more preferably 85 to 90 mol%. Moreover, the structural unit (III) is [(I) + (
If) + (III)] is 25 to 5 mol%,
Preferably 18 to 8 mol%, more preferably 15 to 1
It is 0 mol%. Structural unit [(II) + (III)
] is [(II + <It) + (III)] 9
If it is larger than 5 mol%, the effect of the present invention will be reduced, and 75
If it is less than mol%, the effect of the present invention will be reduced.

In addition, the structural unit (I)/(■) molar ratio is 75/25 to 9
515, preferably 78/22 to 93/7. If it is less than 75/25 or greater than 9515, the heat resistance and fluidity will be poor, which is not preferable. Moreover, the structural unit (IV) is the structural unit [(■) + (III>
] is substantially equimolar.

The method for producing the liquid crystal polyester used in the present invention is not particularly limited, and it can be produced according to known polyester polycondensation methods.

The melting point of the liquid crystal polyester used in the present invention is 280-3
The temperature is preferably 50°C, particularly preferably 290 to 330°C. Further, the melt viscosity is preferably 10 to 15,000 voids, particularly preferably 20 to 5,000 voids.

Note that this melt viscosity is (melting point + 10°C) at a slip rate of 1,
000 (1/sec) using a Koka type flow tester.

On the other hand, the logarithmic viscosity of this liquid crystal polyester is 0°1 g/d
, I! The concentration can be measured in pentafluorophenol at 60°C, and for polyesters consisting of structural units (I) to (IV), the concentration is preferably 0.5 to 5°0617g; 1.
0-3. Particularly preferred is OdN/g.

The effects of the present invention are remarkable in liquid crystalline polyesters that satisfy these conditions, and these effects are extremely small in ordinary non-liquid crystalline polyesters (such as polyethylene terephthalate and polybutylene terephthalate).

In addition, when polycondensing the liquid crystal polyester (A>) used in the present invention, in addition to the components constituting the above (I) to (IV), 4,4-1-diphenyldicarphonic acid, 3,3-diphenyl Aromatic dicarboxylic acids such as dicarboxylic acid, 3,4-diphenyl dicarboxylic acid, 2,2-mono-diphenyl dicarboxylic acid, and 1,2-bis(2-chlorophenoxy)ethane-4,4-mono-dicarboxylic acid. acids, alicyclic dicarboxylic acids such as hexahydroterephthalic acid, aromatic dihydroxy compounds such as resorcinol, chlorohydroquinone, methylhydroquinone, 2,7-hydroxynaphthalene, m
- aromatic oxycarboxylic acids such as oxybenzoic acid, 2,6-oxynaphthoic acid and p-aminophenol, p
-Aminobenzoic acid or the like may be further copolymerized within a small proportion that does not impair the purpose of the present invention.

The plate-like or granular filler (B) in the present invention is not particularly limited, and known ones can be used. For example, calcium silicate (wallastenite), calcium phosphate, calcium sulfate, calcium carbonate, magnesium carbonate, barium sulfate, titanium oxide, aluminum oxide, magnesium oxide, tin oxide, silicon oxide, iron oxide,
Zirconium oxide, molybdenum dioxide, molybdenum disulfide, mica, sericite, talc, kaolin, clay, feldspar, vermiculite, silica, glass powder, carbon black, graphite, resin powder, ebonite powder, etc. are preferably used; It is essential that the moisture content is more than 0.15%, preferably 0.2% or more, and after drying the filler to a moisture content of 0.15% or less, preferably 0.1% or less, the liquid crystal Filling with polyester is essential.

If the moisture content before drying is 0.15% or less, the mechanical strength of the molded product will not be significantly affected even if it is undried, and it will be omitted from the filler in the present invention.

This moisture content is the moisture content measured according to JIS-5101, and is 0.00% by drying in a hot air dryer or vacuum dryer at 100'C or more, preferably 110 to 120°C for 3 hours or more. It can be reduced to 15% or less.

The amount of this filler is 1 to 200 parts by weight, preferably 20 to 150 parts by weight, based on 100 parts by weight of the liquid crystal polyester. If it is less than 1 part by weight, the drying effect will be small and the mechanical anisotropy reducing effect will not be achieved. However, if it exceeds 200 parts by weight, it is difficult to fill and is not preferred. Further, the surface of the filler may be treated with a silane coupling agent, a titanate coupling agent, or the like. In addition, glass fiber,
Reinforcing materials such as carbon fiber and whiskers may also be used.

Note that 0.00% of the epoxy compound is added to the resin composition of the present invention.
It is preferable to contain 5 to 20 parts by weight, preferably 0.1 to 5 parts by weight, from the viewpoint of mechanical strength and mechanical anisotropy.

Examples of this epoxy compound include glycidyl ethers such as bisphenol A diglycidyl, ortho-phenylphenol glycidyl ether, and bisphenol A type epoxy compounds of the following structural formula (1), hexahydrophthalic acid diglycidyl ester, and tetrahydrophthalic acid diglycidyl ester. glycidyl esters such as, glycidyl ether esters of the following structural formula (2), ethylene/glycidyl methacrylate copolymers and ethylene/glycidyl methacrylate/vinyl acetate copolymers containing 1 to 30% by weight of glycidyl methacrylate. Epoxysilanes such as γ-glycidoxypropyltrimethoxysilane, γ-crisitoxypropylmethyldimethoxysilane, and 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, etc. Of these, epoxysilanes are most preferred.

(n is O~20) (Ar is 1,4-phenylene, 1,3-phenylene, 2
, 6-naphthylene, etc., and n is ◯ to 20. ) In the present invention, it is also preferable to fill with an organic flame retardant, brominated polystyrene, brominated epoxy compound, brominated polycarbonate, brominated polyphenylene ether, etc., since mechanical anisotropy can be reduced.

The composition of the present invention contains antioxidants and heat stabilizers (for example, hindered phenols, silicoquinones, phosphites, and substituted products thereof), ultraviolet rays, etc., to the extent that the objects of the present invention are not impaired. Absorbents (e.g. resorcinol, saliterate, penztriazole, benzophenone, etc.), lubricants and mold release agents (e.g. montanic acid and its salts, its esters, its half esters, stearyl alcohol, stearamide and polyethylene waxes), dyes (e.g. nitrosine, etc.) and customary additives such as colorants, plasticizers, antistatic agents, including pigments (e.g. cadmium sulphide, phthalocyanines, carbon fibers, etc.) and other thermoplastics can be added to impart the desired properties. .

The resin composition of the present invention is preferably melt-kneaded, and known methods can be used for melt-kneading. For example, the composition can be prepared by melt-kneading at a temperature of 200 to 400°C using a Banbury mixer, a rubber roll machine, a kneader with two axles, or a twin-screw extruder, but especially at a temperature of 290 to 330°C. The effect of the present invention is greatest when the composition is melt-kneaded.

<Example> Hereinafter, the present invention will be explained in detail with reference to Examples.

Reference Example 1 1105 parts by weight of p-hydroxybenzoic acid, 140 parts by weight of 44-dihydroxybiphenyl, 1067 parts by weight of acetic anhydride, 125 parts by weight of terephthalic acid, and an intrinsic viscosity of about 0.
．． 240 parts by weight of polyethylene terephthalate of 6 dρ/g was charged into a reaction vessel equipped with a stirring blade and a distillation tube, and acetic acid depolycondensation was carried out under the following conditions.

First, under a nitrogen gas atmosphere at 100 to 250°C for 5 hours,
After reacting at 50-315℃ for 1.5 hours, 315℃
, the pressure was reduced to 0.5 mmHg in 1.5 hours, and then 1.0
When the reaction was carried out for a period of time to complete the polycondensation, almost a theoretical amount of acetic acid was distilled out, and a resin having the following theoretical structural formula (a>
I got it.

+0CH2CH20→-/ ni/, Q /m/n=80/7.5/12.5/Also,
This polyester was placed on the sample stage of a polarizing microscope and the temperature was raised to confirm the optical anisotropy. As a result, the melting point measured with a differential scanning calorimeter was 312°C, indicating good optical anisotropy. . Logarithmic viscosity of this polyester (measured at 60 °C in pentafluorophenol at a concentration of 0.1 g/dρ)
is 1.96dρ/g, 322℃, sliding speed 1.0
The melt viscosity at 0.00/sec was 10 voids.

Example 1 Liquid crystal polyester 10 obtained according to the method of Reference Example 1
Talc (Hytron A, manufactured by Takehara Chemical Industry ■, moisture content 0.4%, dried in a hot air dryer at 115°C for 10 hours to give a moisture content of 0.10%)
43 parts by weight and 1 part by weight of epoxy silane (Toshi Dow Corning Silicone ■5H-6040) were melt-mixed and pelletized using a 30 mmφ twin screw extruder set at 310°C.

Next, the obtained pellets were subjected to a Susumu Nestar injection molding machine Promat 40/25 (manufactured by Susumu Heavy Industries), and 70×
A square plate (side gate) of 70 x 2 mm was molded.

Cut out 1/2" width pieces from this square plate in the resin flow direction (MD) and in the direction perpendicular to the flow direction (TD), respectively.
Flexural strength was measured according to TM D790.

The MD force direction strength was 1250 kgf/*, the TD force direction strength was 730 kgf/-, and the anisotropy (MD/TD) was 1.71.

Comparative Example 1 After extrusion and molding in the same manner as in Example 1 except that the talc (moisture content 0.4%) of Example 1 was used without drying, the bending strength was measured, and the MD force direction was Strength 1
00100O/ca, TD force direction strength 520kgf/=
Both have low strength and anisotropy (MD/TD) of 1.9.
2, which was larger than that of Example 1.

Example 2 Instead of 43 parts by weight of talc in Example 1, mica (Micalet A-21PE, manufactured by Yamaguchi Mica Aji, moisture content 0.3%) was dried in a hot air dryer at 115°C for 110 hours to reduce the moisture content. After extrusion and molding using 67 parts by weight (0.07%) in the same manner as in Example 1, the bending strength was measured, and the MD force direction strength was 1210 kgf/crM, TD
The force direction strength was 760 kgf/- and the anisotropy (MD/TD) was 1.59.

Comparative Example 2 After extrusion and molding in the same manner as in Example 2 except that the mica (moisture content 0.3%) of Example 2 was used without drying, the bending strength was measured, and the MD force direction was Strength 1
040 kg f/oa, TD force direction strength 620
kg f/*, both have low strength and anisotropy (MD
/TD) was also 1.68, which was larger than in Example 2.

<Effects of the Invention> The liquid crystal polyester resin composition of the present invention has high mechanical strength and low mechanical anisotropy, so it can be used for various purposes such as electrical and electronic parts.

Patent application Daitoshi Co., Ltd.

Claims (1)

Scope of Claims: (1) 1 to 200 parts by weight of a plate-shaped or granular filler with a moisture content of more than 0.15% is added to 100 parts by weight of liquid crystal polyester (A) with a moisture content of 0.15%. A liquid crystal polyester resin composition characterized in that it is filled after being dried to less than %. (2) The liquid crystal polyester resin composition according to claim (1), wherein the liquid crystal polyester contains an ethylenedioxy unit as an essential component.