JPH02102257A - Resin composition - Google Patents

Abstract

PURPOSE:To make it possible to form a resin composition excellent in heat resistance, rigidity and dimensional accuracy by mixing a liquid crystal polyester of a specified structure with a polycarbonate. CONSTITUTION:This resin composition is prepared by mixing 99-1wt.% liquid crystal polyester comprising structural units of formulas I, II and III (wherein X is at least one group selected from among those of formulas IV, V and VI, -CH2CH2-, etc., the carbonyl groups of each structural unit II or III are para or meta to each other, and at least 50mol% carbonyl pairs are in the para position), having a heat distortion temperature of 190-280 deg.C, a liquid crystal initiation temperature <=330 deg.C and a melt viscosity <=10000P and forming an anisotropic molten phase of a specified structure with 1-99wt.% polycarbonate.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a resin composition with high dimensional accuracy and excellent heat resistance, rigidity and dimensional stability.

<Conventional technology> In recent years, the demand for higher performance plastics has increased, and many polymers with various new performances have been developed and are on the market. Optically anisotropic liquid crystal polymers are attracting attention because they have excellent mechanical properties.

Examples of polymers that form an anisotropic melt phase include p-droxybenzoic acid and 4,4-d-droxybiphenyl, terephthalic acid and t-butylhydroquinone, hydroquinone, 2,6-d-droxynaphthalene, Liquid crystalline polyester copolymerized with isophthalic acid, polyethylene terephthalate, etc. is known (Japanese Unexamined Patent Publication No. 62-39622).
No. 62-164719, Japanese Patent Application Laid-Open No. 1982-164719
Publication No. 292832, Japanese Unexamined Patent Publication No. 63-30523,
(Japanese Unexamined Patent Publication No. 63-33418).

In addition, JP-A No. 57-40551 discloses a composition made of liquid crystal polyester and polycarbonate that has an insufficient balance between heat resistance and moldability and is intended to improve mechanical properties such as tensile strength and impact strength. Disclosed in the official gazette.

<Problem to be solved by the invention> When p-droxybenzoic acid and 4,4-monodihydroxybiphenyl, terephthalic acid are combined with t-butylhydroquinone, hydroquinone, 2,6-dihydroxynaphthalene, isophthalic acid, polyethylene terephthalate, etc. Polymerized liquid crystal polyester has a good balance of heat resistance and fluidity, but there is anisotropy in the molding shrinkage rate during injection molding, and the value in the polymer flow direction is extremely small, but compared to the direction perpendicular to this, the mold shrinkage rate is anisotropic. On the other hand, polycarbonate lacks heat resistance and homogeneity, and unlike crystalline polymers, even if it is reinforced with glass fiber to improve rigidity, the improvement in heat distortion temperature is small, and There was a problem that warpage occurred on the product.

Furthermore, the composition described in JP-A No. 57-40551 has the problem of not having a balance between heat resistance and moldability, and furthermore, the problem of warpage cannot always be fully resolved. I understand.

Therefore, an object of the present invention is to solve the above-mentioned problems and obtain a resin composition with high dimensional accuracy that is excellent in heat resistance, rigidity, and dimensional accuracy.

Means for Solving the Problems〉 That is, the present invention has the following structural units whose thermal deformation temperature is 190 to 280°C, the liquid crystal start temperature is 330°C or less,
This is a resin composition consisting of 99 to 1% by weight of a liquid crystal polyester (A) that forms an anisotropic melt phase with a specific structure and a melt viscosity of 10,000 poise or less, and 1 to 99% by weight of a polycarbonate (B).

It represents one or more groups selected from CH2CH2-, and the carbonyl groups of the structural unit (II), (I[[) are in a para- or meta-position relationship with each other - 50 mol% or more of them are in the para-position) The structural unit (I) of the liquid crystal polyester (A) in the present invention is a W4 structural unit of a polyester produced from p-hydroxybenzoic acid, and the structural unit (n) is a 4,4-
- The structural unit of a polyester produced from di-doxybiphenyl and terephthalic acid and/or isophthalic acid, the structural unit (1) is hydroquinone, t-butylhydroquinone, phenylhydroquinone, 2,6-di-doxynaphthalene, one or more dihydroxy compounds selected from ethylene glycol and terephthalic acid and/or
or the structural unit of polyester produced from isophthalic acid.

The liquid crystal polyester (A) of the present invention has the structural unit (I)
, (n) and (In).

The copolymer of the #IJ structural units (I>, (II) and (DI)) is optional. From the viewpoint of fluidity, the following copolymerization amount is preferable. That is, the structural unit (I> is It is preferably 40 to 90 mol% of the total, particularly 60 to 90 mol%.
It is preferable that it is 78 mol%. Further, the molar ratio of the structural unit (U)/(I[) is preferably 9/1 to 1/9, and in the structural unit (1), -X- is -CH2CH
In cases other than 2-, 7.5/2.5 to 2.5/7.5 is preferable, and 7.5/2.5 to 4/6 is particularly preferable.

The liquid crystal polyester (A) used in the present invention has a heat distortion temperature of 190 to 280°C when no filler is blended.

If the heat distortion temperature is less than 190°C, the heat resistance is insufficient,
If the temperature exceeds 280°C, a problem arises in that the molding temperature of the resulting resin composition becomes high.

Here, the heat distortion temperature is 1 based on ASTM D648.
/ 8" thick test piece measured at a stress of 18.6 kg/-.

In addition, the liquid crystal starting temperature of the liquid crystal polyester (A) is 33
It is essential that the temperature is 0°C or lower, and preferably 260 to 330°C from the viewpoint of fluidity and heat resistance.

If the liquid crystal start temperature exceeds 330'C, it will be necessary to increase the molding temperature, which is not practical from the viewpoint of moldability.

In addition, it is essential that the melt viscosity is 10,000 poise or less, preferably 5,000 poise or less, especially 2
,000 poise or less is more preferable.

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

The method for producing liquid crystal polyester (A) in the present invention is as follows:
There are no particular restrictions, and it can be produced according to known polyester polycondensation methods.

For example, in the structural unit (I), -X- is CH2CH
In cases other than 2-, in the following (1) to (4), X- is -〇 H
In the case of 2CH2-, the production method (5) is preferably mentioned.

(1) Manufactured by deacetic acid polycondensation reaction from diacylated aromatic dihydroxy compounds such as p-acetoxybenzoic acid, 4.4-diacetoxybiphenyl, and 4.4-diacetoxybenzene and aromatic dicarboxylic acids such as terephthalic acid. how to.

(2) After reacting an aromatic dihydroxy compound such as P-hydroxybenzoic acid, 4,4-dihydroxybiphenyl, 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-droxybenzoic acid, 4
．． A method for producing by dephenol polycondensation reaction from an aromatic dihydroxy compound such as 4-1 dihydroxybiphenyl or hydroquinone and a diphenyl ester of an aromatic dicarboxylic acid such as terephthalic acid.

(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 dicarboxylic acids such as 4,4-di-hydroxybiphenyl and hydroquinone are prepared. A method of manufacturing by adding a dihydroxy compound and performing a phenol-free polycondensation reaction.

(5) A method of producing by method (1) or (2) in the presence of polyethylene terephthalate.

Since liquid crystal polyester (A) with a high degree of polymerization is obtained, (
It is more preferable to use method 2).

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

The liquid crystal polyester (A) of the present invention can be measured for intrinsic viscosity in pentafluorophenol, and in this case, Q, 1 g/ct, l! The value measured at 60°C at a concentration of 0.5 dJ/g or more is preferable, especially 1.
0 to 15.0 dl/g is preferred.

In addition, when polycondensing the liquid crystal polyester (A) used in the present invention, in addition to the components constituting the above (I), (II), and (1), 4,4--diphenyl dicarbonate! 13
．． 3--diphenyldicarboxylic acid, 3,4--diphenyldicarboxylic acid, 2゜2-diphenyldicarboxylic acid,
Aromatic dicarboxylic acids such as 1,2-bis(phenoxy)ethane-4,4-monodicarboxylic acid, 1,2-bis(2-chlorophenoxy)ethane-4,4-dicarboxylic acid, hexadroterephthalic acid, etc. alicyclic dicarboxylic acids, resorcinol, chlorohydroquinone, methylhydroquinone, aromatic dihydroxy compounds such as 2,7-hydroxynaphthalene, aromatic oxycarboxylic acids such as m-oxybenzoic acid, 2,6-oxynaphthoic acid, and 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 polycarbonate (B) in the present invention is a carbonized carbonate containing bis(4-hydroxyphenyl), bis(3゜5-dialkyl-4-hydroxyphenyl) or bis(3,5-dihalo-4-hydroxyphenyl) substitution. Polycarbonates based on hydrogen derivatives are preferred;
Particularly preferred are polycarbonates based on 2,2-bis(4-hydroxyphenyl)propane (bisphenol A).

In the present invention, the blending amount of liquid crystal polyester (A) is 9
9 to 1% by weight, preferably 95 to 5% by weight, particularly preferably 90 to 10% by weight, and the blending amount of polycarbonate (B) is 1 to 99% by weight, preferably 5 to 95% by weight, particularly preferably 10 to 10% by weight. It is 90% by weight. Liquid crystal polyester (
If A) exceeds 99% by weight, the dimensional stability will be insufficient, and if it is less than 1% by weight, the heat resistance and rigidity will be insufficient.

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, salitate, benzotriazole, 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, etc.), dyes (e.g. nitrosine, etc.) and pigments (e.g. Common additives such as colorants, flame retardants, plasticizers, antistatic agents, reinforcing agents (e.g. glass fibres, talc, clay, mica, silica, wollastenite, etc.) Other thermoplastics can be added to impart certain 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 1 single-screw or twin-screw extruder, or the like.

<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 approximately 0.6dj
/g of polyethylene terephthalate was charged into a reaction vessel equipped with a stirring blade and a distillation tube, and acetic acid depolycondensation was performed under the following conditions.

First, under a nitrogen gas atmosphere at 100-250'C for 5 hours 2
After reacting at 50-300℃ for 1.5 hours, 300℃
When the pressure was reduced to 0.5 Hg in 1 hour and the reaction was further carried out for 2.25 hours to complete the polycondensation, an almost theoretical amount of acetic acid was distilled out and a resin (A- 1)
I got it.

1/m/n75=10/15 Also, place this polyester on the sample stage of a polarizing microscope,
As a result of confirming the optical anisotropy by increasing the temperature, the liquid crystal initiation temperature was 264° C., indicating good optical anisotropy. The logarithmic viscosity of this polyester (0.1 g/d, measured at 60° C. in pentafluorophenol at a concentration of Q) is 1.96
dj/, and the melt viscosity at 304° C. and a rubbing speed of 1,000/sec was 910 poise.

Reference Example 2 p-Droxybenzoic acid 62.44 parts by weight, 4°4--
14.03 parts by weight of di-hydroxybiphenyl, 18.40 parts by weight of 2,6-diacedoxynaphthalene, 25.03 parts by weight of terephthalic acid and 67.69 parts by weight of acetic anhydride were added to a reactor equipped with a stirring blade and a distillation tube. Pour into a reaction container and heat at 130-250°C for 4.5 hours at 250-300°C under nitrogen gas atmosphere.
After reacting at ℃ for 2.5 hours, the temperature was raised to 330℃ and 1
When the pressure was reduced to 0.3 mm+Hg and the reaction was further carried out for 2 hours to complete the polycondensation, almost a theoretical amount of acetic acid was distilled out, and a resin (A-2) having the following theoretical structural formula was obtained.

1/m/n=75/12. 5/12. 5 In addition, when this polyester was placed on the sample stage of a polarizing microscope and the temperature was raised to confirm the optical anisotropy, the liquid crystal initiation temperature was 263
℃, showing good optical anisotropy. The logarithmic viscosity of this polyester (measured under the same conditions as Reference Example 1) is 6.3
dJl/g, and the melt viscosity at 303° C. and a rubbing speed of 1,000/sec was 1,200 poise.

Examples 1 to 4 Liquid crystal polyester (A) and polycarbonate (B) were used in the ratio shown in Table 1 at a temperature of 280 to 300°C.
The mixture was melt-mixed using a twin-screw extruder with a diameter of 1.5 mm to obtain a composition. The resulting composition was molded using an injection molding machine with an injection capacity of 5°2, at a molding temperature of 280-300°C and a mold temperature of 90-300°C.
A test piece of 1/4" x 1/2" x 5" and a square plate of 70 city x 7011 Il x 2 city were molded at 110°C.

Then, using the test piece, the heat distortion temperature (18.6hg/a++t) was determined according to the ASTM D648 standard.
Flexural modulus was measured according to TM D790 standard.

In addition, the dimensions of the square plate in the direction perpendicular to the flow direction of the polymer were measured to determine the molding shrinkage rate.

These results are shown in Table 1.

Comparative Examples 1 to 3 Molding and evaluation were performed in the same manner as Examples 1 to 4 using liquid crystal polyester (A) and polycarbonate (B).

These results are shown in Table 1.

As shown in Table 1, the compositions of the present invention of Examples 1 to 4 have high heat distortion temperatures, excellent heat resistance, high flexural modulus, and excellent rigidity. In addition, the molding shrinkage rate and its anisotropy are small, and the dimensional stability is excellent.

<Effects of the Invention> According to the present invention, a resin composition with high dimensional accuracy and excellent heat resistance, machinability, and dimensional stability can be obtained by blending polycarbonate with a liquid crystal polyester having a specific structure.

Claims (1)

[Claims] Consisting of the following structural unit, the heat deformation temperature is 190 to 280°C,
Liquid crystal start temperature is 330℃ or less, melt viscosity is 10,000
A resin composition comprising 99 to 1% by weight of a liquid crystal polyester (A) and 1 to 99% by weight of a polycarbonate (B), which form an anisotropic melt phase with a specific structure of poise or less. ▲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) (However, X in the formula is ▲Mathematical formula, chemical formula, etc.) There are tables, etc.▼
, ▲There are mathematical formulas, chemical formulas, tables, etc.▼,▲Mathematical formulas, chemical formulas,
There are tables, etc. ▼, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼
, -CH_2CH_2-, the carbonyl groups of the structural units (II) and (III) are in a para- or meta-position relationship with each other, and 50 mol% or more of them are in the para-position)