JPH0359067A - Optically anisotropic polyester resin composition - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to an optically anisotropic polyester resin composition that has excellent heat resistance, moldability, fluidity, and mechanical properties, particularly high weld strength. .

<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 crystal polymers have attracted attention because of their excellent mechanical properties.

Examples of polymers that form an anisotropic melt phase include liquid crystal polymers obtained by copolymerizing p-hydroxybenzoic acid with polyethylene terephthalate (Japanese Patent Application Laid-open No. 72393/1983);
Liquid crystal polymer copolymerized with p-hydroxybenzoic acid and 6-hydroxy-2-naphthoic acid
Also known are liquid crystal polymers prepared by copolymerizing p-hydroxybenzoic acid with 4°4''-dihydroxybiphenyl, terephthalic acid, and isophthalic acid (Japanese Patent Publication No. 57-24407).

Furthermore, it is known that glass fibers are blended in order to improve the heat resistance and weld strength of liquid crystal polymers.

<Problems to be Solved by the Invention> However, the liquid crystal polymers known so far have a low heat distortion temperature of less than 190°C, and have insufficient heat resistance, or have a heat distortion temperature of 190°C. The above shows good heat resistance, but the liquid crystal start temperature is too high, reaching 400°C.
It has been difficult to obtain a liquid crystal polymer that has a good balance between heat resistance, moldability, and fluidity, as it cannot be molded unless it is higher than the above, and has a high melt viscosity.

In addition, attempts have been made to incorporate glass fiber to improve the weld strength of liquid crystal polymer molded products, but the weld strength improvement effect is not necessarily large and there is a problem in that fluidity is significantly reduced.

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, fluidity, and mechanical properties, particularly high weld strength of molded products.

Means for Solving the Problems> That is, the present invention consists of the following structural units [(TECH>, (IT> and (IV))] or [(I), (I[>, (III) and (IV)]). , 99 to 20% by weight of an optically anisotropic polyester (A) forming an anisotropic melt phase with a liquid crystal onset temperature of 330°C or lower and a melt viscosity of 10.000 poise or lower, acicular titanium oxide whiskers (B), and/or or acicular aluminum borate whiskers (C>1 to 80% by weight)
The present invention relates to an optically anisotropic polyester resin composition comprising:

+O-R, -0-)- (II) represents one or more groups selected from 10-CH2 CH2-○← (III) +CO-R2-CO-)- (IV), and R2 is selected from or chlorine or hydrogen, and the structural unit (IV) is substantially the structural unit [(II) +
(III) ]. > The above structural unit (I) of the optically anisotropic polyester (A) in the present invention is p
- The structural unit (II) of the polyester produced from hydroxybenzoic acid is 4.4-dihydroxybiphenyl, 3.3-. 5.5--tetramethyl-4
, 4-dihydroxybiphenyl, hydroquinone, t
-Butylhydroquinone, phenylhydroquinone, 2
．． 6-hydroxynaphthalene, 2.7-hydroxynaphthalene, 2.2-bis(4-hydroxyphenyl)
Structural unit (I) is a structural unit produced from propane and 4.4'-dihydroxydiphenyl ether, structural unit (I) is a structural unit produced from ethylene glycol, and structural unit (I) is a structural unit produced from ethylene glycol.
IV) is terephthalic acid, isophthalic acid, 4,4-diphenyldicarboxylic acid, 2,6-naphthalene dicarboxylic acid, 1,2-bis(phenoxy>ethane-4,4゛-dicarboxylic acid, 1,2-bis(phenoxy)ethane-4,4゛-dicarboxylic acid, Each structural unit produced from one or more aromatic dicarboxylic acids selected from 2-chlorophenoxy>ethane-4,4'-dicarboxylic acid is shown.

The optically anisotropic polyester in the present invention (A> is the above structural unit [(I), (II) and (IV)] or [(
I), (I), (III), (III) and (IV)
] It is a copolymer consisting of

The above structural units (), (III), (II), (III)
The amount of copolymerization of (IV) and (IV) is arbitrary. However, from the viewpoint of fluidity, the following copolymerization amount is preferred.

That is, when the above structural unit (III) is included, the above structural unit [(), (III)+(n)] is [(II+(I)
I)+(m)] is preferably 660 to 95% by weight, particularly preferably 80 to 92% by weight. Moreover, the structural unit (I[I) is [(■) + (II) +
(III)] is preferably 440 to 5 mol, and 20 to 8 mol
Particularly preferred is mole %.

In addition, the molar ratio of structural unit (I)/(If> is 75/2
5 to 9515 is preferable, and the structural unit (IV) is substantially equimolar to the structural unit [(I[>+(III)]).On the other hand, when the above structural unit (I[I) is not included, the structural unit (), (III) is 44 of [(I) + (II)]
It is preferably 0 to 90 mol%, particularly preferably 60 to 88 mol%, and the structural unit (IV) is substantially equimolar to the structural unit (If>).

Further, the liquid crystal initiation temperature of the optically anisotropic polyester (A) is essential to be 330°C or lower, and preferably from 240 to 330°C from the viewpoint of fluidity and heat resistance.

If the liquid crystal start temperature exceeds 330° C., it becomes necessary to raise the molding temperature, which is not practical in terms of moldability.

preferable.

The melt viscosity is a value measured using a Koka type flow tester at a liquid crystal start temperature +40° C. and a slip rate of 1.000 (1/sec).

The method for producing the optically anisotropic polyester (A) in the present invention is not particularly limited, and can be produced according to known polyester polycondensation methods.

For example, when the above-mentioned structural unit (III) is not contained, the following manufacturing methods (1> to (4)) are preferably used, and when the above-mentioned structural unit (III) is contained, the following manufacturing methods are preferably used.

(1) A method for producing a diacylated aromatic dihydroxy compound such as p-acetoxybenzoic acid, 4,4'-diacetoxybiphenyl, para-acetoxybenzene, etc. and an aromatic dicarboxylic acid such as terephthalic acid by deacetic acid polycondensation reaction.

(2) After reacting an aromatic dihydroxy compound such as p-hydroxybenzoic acid, 4.4-monodihydroxybiphenyl, or hydroquinone, or an aromatic dicarboxylic acid such as terephthalic acid with acetic anhydride to acylate the phenolic hydroxyl group, A method of producing by deacetic acid polycondensation reaction.

(3) Phenyl ester of p-hydroxybenzoic acid, 4
, 4-dihydroxybiphenyl, hydroquinone and other aromatic dihydroxy compounds and diphenyl esters of aromatic dicarboxylic acids such as terephthalic acid by dephenol polycondensation reaction.

(4) Aromatic dicarboxylic acids such as p-hydroxybenzoic acid and terephthalic acid are reacted with a desired amount of diphenyl carbonate to form diphenyl esters, and then aromatic dihydroxy compounds such as 4.4-dihydroxybiphenyl and hydroquinone are reacted. In addition, a method of producing by dephenol polycondensation reaction.

(5) In the presence of an oligomer or polymer consisting of ethylene glycol and aromatic dicarboxylic acid or bis(β-hydroxyethyl) ester of aromatic dicarboxylic acid (1
〉 or method of manufacturing by method (2).

According to the production method (5), an oligomer or polymer consisting of ethylene glycol and aromatic dicarboxylic acid is randomly incorporated into the molecular chain by transesterification,
It is thought that a liquid crystal polyester containing the above structural unit (nI) can be obtained.

A catalyst may be used as necessary during the polymerization reaction. Typical catalysts used in polycondensation reactions include metal compounds such as stannous acetate, tetrabutyl titanate, potassium acetate, antimony trioxide, magnesium, sodium acetate, and zinc acetate. It is effective for

Some of the optically anisotropic polyesters (A) in the present invention can be measured for their intrinsic viscosity in pentafluorophenol;
The value measured at 0°C is preferably 0.5 dN/g or more, and if the structural unit (III) is included, it is 0.5 to 3.0 dd)/
g, 'jf4 structural unit (1 if it does not contain I[[).
Particularly preferred is 0 to 15.0 dfl/g.

In addition, when polycondensing the optically anisotropic polyester (A> used in the present invention), in addition to the components constituting the above (I), (II), (III), and (IV), 3,3--diphenyl dicarbonate is added. acid, 3,4-monodiphenyldicarboxylic acid,
2. Aromatic dicarboxylic acids such as 2-1-diphenyldicarboxylic acid, alicyclic dicarboxylic acids such as hexahydroterephthalic acid, aromatic dihydroxy compounds such as resorcinol, chlorohydroquinone, methylhydroquinone, and bis(4-hydroxyphenyl>sulfone) , 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, L4-cyclohexanediol, 1,4-cyclohexanediol, aliphatic, cycloaliphatic diols and m-oxybenzoic acid, 6- Aromatic hydroxycarboxylic acids such as hydroxy-2-naphthoic acid, p-aminophenol, p-aminobenzoic acid, etc. can be further copolymerized within a small proportion that does not impair the object of the present invention.

The acicular titanium oxide whisker (B) used in the present invention has a chemical composition of TiOz, has a rutile crystal form, and has an acicular shape. The average fiber length of the whiskers is preferably 1 to 50 μm, particularly preferably 3 to 15 μm. Also, the average fiber diameter of the whiskers is 0
゜01~0.5μm is preferable, and 0.02~0.
Particularly preferred is 2 μm.

Further, the acicular aluminum borate whisker (C) used in the present invention has a chemical composition of 9 A 1203 .2B203 and has an acicular shape. The average fiber length of the whiskers is preferably from 5 to 100 μm, particularly preferably from 10 to 50 μm. Further, the average fiber diameter of the whiskers is preferably 0.05 to 1.5 μm, particularly preferably 0.5 to 1.0 μm.

In addition, the acicular titanium oxide whiskers (B) and the acicular aluminum borate whiskers (C) are coated with coupling agents such as γ-(2-aminoethyl)aminopropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, and γ-glycidoxypropyltrimethoxysilane. Silane coupling materials such as methoxysilane, γ-mercaptopropyltrimethoxysilane, methyltrimethoxysilane, γ-anilinopropyltrimethoxysilane, hydroxypropyltrimethoxysilane, γ-ureidopropyltriethoxysilane, vinyl acetoxysilane, etc. Isopropyl tris isostearoyl titanate, isopropyl tris (dioctyl pyrophosphate) titanate, isopropyl tris (N-aminoethyl-
Titanate coupling agents such as aminoethyl titanate, tetraoctyl bis(ditridecyl phosphite) titanate, bis(dioctyl pyrophosphate) ethylene titanate, isopropyl tridecylbenzenesulfonyl titanate, isopropyl tri(dioctyl phosphate) titanate, and acetate It may be used after being subjected to coupling treatment with an aluminum coupling agent such as alkoxyaluminum diisopropylate, a zircoaluminate coupling agent, or the like.

Glass fibers may further be added to the composition of the present invention. Preferred specific examples of the glass fiber include chopped strand and roving type glass fibers with a diameter of 5 to 15 μm for ordinary reinforced resins.

1 to 6 from the viewpoint of ease of handling, imparting surface gloss to the molded product, etc.
Long chopped strands are particularly preferably used.

The glass fibers are preferably treated with a conventional coupling agent such as silane or titanium, and may also be treated with a conventional binding agent such as epoxy resin or vinyl acetate.

In the present invention, the blending amount of the optically anisotropic polyester (A) is 99 to 20% by weight, preferably 95 to 30% by weight.
, the blending amount of the acicular titanium oxide whiskers (B) and/or the acicular aluminum borate whiskers (C) is 1 to 1.
80% by weight, preferably 5 to 70% by weight, and the amount when adding glass fiber is liquid crystal polyester (A)
and acicular titanium oxide whiskers (B) and/or acicular aluminum borate whiskers (C) in a total of 100 parts by weight, preferably less than 200 parts by weight,
Particularly preferred is 5 to 150 parts by weight. If the blending amount of the optically anisotropic polyester (A) exceeds 99% by weight, the effect of improving heat resistance and mechanical properties will be insufficient, and if it is less than 20% by weight, the moldability and fluidity will significantly deteriorate, making it impractical. .

The composition of the present invention may contain antioxidants, heat stabilizers (for example, hindered phenol, hydroquinone, phosphites, and substituted products thereof), ultraviolet absorbers ( (e.g. resorcinol, salicylates, benzotriazoles, benzophenones, 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 pigments (e.g.
Customary additives such as colorants, flame retardants, plasticizers, antistatic agents, other fillers, reinforcing agents, and other thermoplastic resins, including colorants such as cadmium sulfide, phthalocyanine, carbon black, etc. characteristics can be imparted.

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 Nigu, a single-screw extruder, or a single-screw or twin-screw extruder.

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

Reference Example 1 466 parts by weight of P-hydroxybenzoic acid, 84 parts by weight of 4°4°-dihydroxybiphenyl, 480 parts by weight of acetic anhydride, 75 parts by weight of terephthalic acid, and an intrinsic viscosity of about 0.6 c.
130 parts by weight of polyethylene terephthalate (Nl/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 50-300℃ for 1.5 hours, 300℃
, the pressure was reduced to 0.5 nwnHg in 1 hour, and then 2.25
When the reaction was carried out for a period of time to complete the polycondensation, a nearly theoretical amount of acetic acid was distilled out, and a resin having the following theoretical structural formula was obtained.

+0-CH2 CH2-0←/k/fI/m/n=75/10/15/25 Also, place this polyester on the sample stage of a polarizing microscope and raise the temperature.
As a result of confirming the optical anisotropy, the liquid crystal starting temperature was 264
℃, showing good optical anisotropy. The logarithmic viscosity of this polyester (o, measured at 60°C in pentafluorophenol at a concentration of Ig/dfJ) is 1.96 dJ2/g.
The melt viscosity at 304° C. and a shear rate of 1.000 weight seconds was 910 poise.

Reference Example 2 541 parts by weight of P-acetoxybenzoic acid, 184 parts by weight of 4゜4゛-diacetoxybiphenyl! , 62 parts by weight of hydroquinone diacetate and 124 parts by weight of terephthalic acid,
42 parts by weight of isophthalic acid was charged into a reaction vessel equipped with a stirring blade and a distillation tube, and the reaction was carried out at 250 to 360°C for 3 hours in a nitrogen gas atmosphere, then the pressure was reduced to 1 nw Hg, and the mixture was further heated for 1 hour. The condensation was completed to obtain a resin (b) having the following theoretical structural formula.

k/1 /m/n10=75/13.13/6.7/1
8.75/6.25 When this polyester was placed on the sample stage of a polarizing microscope and heated to confirm the optical anisotropy, the liquid crystal onset temperature was 30
5° C., showing good optical anisotropy. The logarithmic viscosity of this polyester (measured under the same conditions as Reference Example 1) is 4.1
cH1/g, and the melt viscosity at 345° C. and a shear rate of 1,000 weight seconds was 3,500 poise.

Examples 1-7. Comparative Example 1.2 Liquid crystal polyester (A), acicular titanium oxide whiskers (
B), acicular aluminum borate whiskers <C>, and glass fibers (D) at the ratio shown in the table from 300 to 360
Melt and mix using a 40-diameter single-screw extruder set at ℃,
A resin composition was prepared.

The obtained resin composition was subjected to a Sumitomo Necool injection molding machine Promat 40/25 (manufactured by Sumitomo Heavy Industries, Ltd.) under the conditions of a cylinder temperature of 300 to 360°C and a mold temperature of 100°C. A test piece of ``x 1/2'' x 5'' and an ASTM Nα4 dumbbell were molded., ASTM Nα4
The dumbbells were molded using both a regular mold (dumbbell I) in which the gate was located at one end of the dumbbell and a weld mold (dumbbell ■) in which the gate was located at both ends of the dumbbell. Then, according to the ASTM D648 standard, the load deflection temperature (18,6 kgf/a ( ) of the 1/8" thick test piece was measured. Also, according to the ASTM D638 standard, the AS
The breaking strength of the TMNα4 dumbbell was measured, and the ratio of the breaking strength of the dumbbell ■ to that of the dumbbell ■ was taken as the weld strength retention rate.

Comparative Examples 3 and 4 1/8" x 1/2 under the conditions of cylinder temperature 300 to 3 50 °C and mold temperature 100 °C, similar to 1 °C 12
A ``x5'' test piece and an ASTM Na4 dumbbell were molded.

Then, the deflection temperature under load, breaking strength, and melt viscosity were measured, and the weld strength retention rate was calculated. These results are shown together in the table.

Comparative Example 5 It has the following theoretical structural formula and has a liquid crystal starting temperature of 359°C.
Melt viscosity at 9℃ and sliding speed of 1.000/sec is 8.80
Using 0 poise liquid crystalline polyester, acicular titanium oxide whiskers (B) and acicular aluminum borate whiskers (C) were added in the proportions shown in the table in Examples 1 to 7.
) and glass fiber (C) are melt-mixed (set temperature 400
℃), molding (cylinder temperature 400℃, mold temperature 210℃)
°C), evaluated. These results are also shown in the table.

,l! /m/n=67/33/33 Compared to Comparative Examples 1 to 5, the resin compositions of Examples 1 to 7 of the present invention had a well-balanced heat distortion temperature and melt viscosity, and had excellent heat resistance and fluidity. ing. In addition, the weld strength retention rate is 26
% or more, and has excellent mechanical properties.

Although the resin composition of Comparative Example 5 has a high deflection temperature under load, its melt viscosity at a molding temperature of 400° C. is as high as 16,000 poise, and its fluidity is low. When the molding temperature exceeded 400°C, generation of pyrolysis gas was observed. Furthermore, the weld strength retention rate was as low as 8%.

<Effects of the Invention> The present invention improves heat resistance by adding acicular titanium oxide whiskers and/or acicular aluminum borate whiskers and, if necessary, glass fiber to a specific liquid crystalline polyester having a limited structural formula. A resin composition having excellent properties, moldability, and fluidity, and high mechanical properties, particularly weld strength, can be obtained.

Patent application Daitoshi Co., Ltd.

Claims (1)

[Claims] Consisting of the following structural units [(I), (II) and (IV)] or [(I), (II), (III) and (IV)],
Liquid crystal start temperature is 330℃ or less, melt viscosity is 10,000
Optically anisotropic polyester (A) 99 to 20% by weight that forms an anisotropic melt phase of less than Poise, acicular titanium oxide whiskers (B) and/or acicular aluminum borate whiskers (C) 1 to 80% by weight An optically anisotropic polyester resin composition consisting of. ▲There are mathematical formulas, chemical formulas, tables, etc.▼(I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼(II) ▲There are mathematical formulas, chemical formulas, tables, etc.▼(III) ▲There are mathematical formulas, chemical formulas, tables, etc.▼( IV) (However, R_1 in the formula represents one or more groups selected from ▲There are mathematical formulas, chemical formulas, tables, etc.▼, and R_2 represents a group selected from ▲There are mathematical formulas, chemical formulas, tables, etc.▼ , X is chlorine or hydrogen, and the structural unit (IV) is substantially the structural unit [(II) + (III)]
is equimolar. )