JPH04213353A - Liquid crystal polyester resin composition - Google Patents

Abstract

PURPOSE:To obtain a liq. crystal polyester resin compsn. with small mechanical anisotropy by compounding a liq. crystal polyester resin forming a specified anisotropic molten phase with a specified silane-contg. compd. CONSTITUTION:A liq. crystal polyester resin compsn. prepd. by compounding 100 pts.wt. liq. crystal polyester resin (A) which consists of the repeating units of formulas I, II and IV or I, II, III and IV and forms an anisotropic molten phase, 0-200 pts.wt. filler (B) and 0.01-20 pts.wt. silane-contg. compd. of formula V. In the formulas, R1 is a group of formula VI, etc., and R2 is a group of formula VII, etc. In addition, the structural unit of formula IV is equimolar with the structural unit of formulas (II+III). Examples of the filler induce glass fibers, ceramic fibers, metal fibers, carbon fiber, clay and titanium oxide. As the compsn. exhibits small mechanical anisotropy, it can be used for various purposes where dimensional accuracy is required, such as electric and electronic parts.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal polyester resin composition having low mechanical anisotropy.

0002

[Background Art] In recent years, the demand for higher performance plastics has increased, and many polymers with various new performances have been developed. Among them, optically anisotropic liquid crystal polymers have excellent chemical resistance and mechanical resistance. It has attracted attention because of its characteristic properties (Japanese Patent Application Laid-Open No. 51-8395, Japanese Patent Application Laid-open No. 49-
72393).

[0003] As the liquid crystal polymer, for example, a liquid crystal polyester obtained by copolymerizing p-hydroxybenzoic acid with polyethylene terephthalate (Japanese Patent Laid-Open No. 49-723
93), liquid crystalline polyester obtained by copolymerizing p-hydroxybenzoic acid with 4,4'-dihydroxybiphenyl, terephthalic acid, and isophthalic acid (Japanese Patent Publication No. 57-24407)
Publication No.) etc. are known.

0004

[Problems to be Solved by the Invention] However, it has been found that liquid crystal polyesters generally have a problem in practicality because they have large mechanical anisotropy as represented by the dimensional accuracy of molded products.

[0005] Therefore, the present invention solves the above problems and
The object of the present invention is to obtain a liquid crystalline polyester resin composition with low mechanical anisotropy.

[0006]

[Means for Solving the Problems] As a result of intensive studies to achieve the above-mentioned problems, the present inventors have developed a liquid crystal polyester consisting of a specific structural unit by adding a specific silane-containing compound such as γ-ureidopropyltriethoxysilane. It was discovered that a resin composition to which the above-mentioned compound was added satisfies the above-mentioned problems, and the present invention was achieved.

That is, the present invention provides (A) the following structural units (I), (II), (IV) or (I), (II)
, (III), (IV) For 100 parts by weight of a liquid crystal polyester resin forming an anisotropic melt phase consisting of:
(B) 0 to 200 parts by weight of a filler and (C) 0.01 to 0.01 to 200 parts by weight of a silane-containing compound represented by the following general formula (i)
This is a liquid crystal polyester resin composition containing 20 parts by weight.

[0008]

[C5]

[0009] (However, R1 in the formula is

0010

[C6]

represents one or more groups selected from R2
teeth

0012

[C7]

Indicates a group selected from: Also, the structural unit (
IV) is substantially a structural unit [(II)+(III)]
is equimolar. )

[0014]

[Chemical formula 8]

(However, n in the formula is an integer of 1 to 5, R
are CH3, C2 H5, C3 H7, C4 H9
represents one or more alkyl groups selected from ) The above structural unit (I) of the liquid crystal polyester (A) in the present invention
is the structural unit of polyester produced from p-hydroxybenzoic acid, and the above structural unit (II) is 4,4'-dihydroxybiphenyl, 3,3',5,5'-tetramethyl-4,4'-dihydroxy Structures generated from biphenyl, hydroquinone, t-butylhydroquinone, phenylhydroquinone, 2,6-dihydroxynaphthalene, 2,7-dihydroxynaphthalene, 2,2-bis(4-hydroxyphenyl)propane and 4,4'-dihydroxydiphenyl ether unit, structural unit (III
) is a structural unit produced from ethylene glycol, and the structural unit (IV) is terephthalic acid, isophthalic acid, 4,4
One or more aromatic compounds selected from '-diphenyldicarboxylic acid, 2,6-naphthalene dicarboxylic acid, 4,4'-diphenyl ether dicarboxylic acid, and 1,2-bis(phenoxy)ethane-4,4'-dicarboxylic acid Each structural unit produced from dicarboxylic acid is shown.

When containing the structural unit (III), when the structural unit produced from 4,4'-dihydroxybiphenyl as the structural unit (II) does not contain the structural unit (III), as the structural unit (II), Structural units formed from 4,4'-dihydroxybiphenyl and 2,6-dihydroxynaphthalene are preferred;
V) is preferably a structural unit produced from terephthalic acid.

The liquid crystal polyester (A) in the present invention comprises the above structural units (I), (II) and (IV) or (
It is a copolymer consisting of I), (II), (III) and (IV).

[0018] The above structural units (I), (II), (III)
) and (IV) can be copolymerized in any amount. 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 [(I)+(II)] is [(I)+(II)+(I
II)] is preferably 60 to 95 mol%,
Particularly preferred is 85 to 93 mol%. Moreover, the structural unit (III) is [(I)+(II)+(III
)] is preferably 40 to 5 mol%, particularly preferably 15 to 7 mol%. In addition, the structural unit (I)/(II
The molar ratio of I) is preferably 75/25 to 95/5, and 8
Particularly preferred is 3/17 to 93/7. Also, the structural unit (
IV) is substantially a structural unit [(II)+(III)]
is equimolar. On the other hand, when the above structural unit (III) is not included, the structural unit (I) is preferably 40 to 90 mol%, particularly preferably 60 to 88 mol% of [(I)+(II)], and the structural unit (IV ) is substantially equimolar with structural unit (II).

The method for producing the liquid crystal polyester (A) in the present invention is not particularly limited, and can be produced in accordance with known polyester polycondensation methods.

For example, when the above structural unit (III) is not included, the following (1), (2), the above structural unit (III)
), the production method (5) is preferably used.

(1) A method for producing a diacylated aromatic dihydroxy compound such as p-acetoxybenzoic acid or 4,4'-diacetoxybiphenyl from 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 or 4,4'-dihydroxybiphenyl with 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 (however, for 2,6-dihydroxynaphthalene, it is preferable to use 2,6-diacetoxynaphthalene).

(3) p-hydroxybenzoic acid phenyl ester,
A method for producing by dephenolization polycondensation reaction from an aromatic dihydroxy compound such as 4,4'-dihydroxybiphenyl 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 dihydroxy compounds such as 4,4′-dihydroxybiphenyl are prepared. A method of manufacturing by adding and removing phenol polycondensation reaction.

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

[0026] According to the production method (5), the oligomer or polymer consisting of ethylene glycol and aromatic dicarboxylic acid is randomly incorporated into the molecular chain by transesterification,
It is considered that a liquid crystal polyester containing the above structural unit (III) can be obtained.

[0027] During the polymerization reaction, a catalyst may be used if necessary. 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

[0028] Some of the liquid crystalline polyesters (A) in the present invention can be measured for their logarithmic viscosity in pentafluorophenol, and in this case, the value measured at 60°C at a concentration of 0.1 g/dl. 0.5 dl/g or more is preferable, and when the structural unit (III) is included, it is 0.5 to 3.0
dl/g, 1. if structural unit (III) is not included.
Particularly preferred is 0 to 15.0 dl/g.

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

If the liquid crystal start temperature exceeds 330° C., it is necessary to increase the molding temperature, which is not practical from the viewpoint of moldability. The liquid crystal start temperature is the temperature at which a liquid crystal emits opalescent light under shear stress when placed on a sample stage of a polarizing microscope.

The melt viscosity is usually 10,000 poise or less, preferably 6,000 poise or less, particularly 4.0 poise or less.
00 poise or less is more preferable.

[0032] This melt viscosity is the same as that of liquid crystal polyester (
When A) contains the structural unit (III), the melting point (T
m) At a temperature of +10°C, if the structural unit (III) is not included, the shear rate is 1 at a temperature of (liquid crystal starting temperature +40°C).
,000 (1/sec) using a Koka type flow tester.

Here, the melting point (Tm) refers to the endothermic peak temperature (T
After observing Tm1), the temperature was maintained at +20°C for 5 minutes, then cooled to room temperature at a cooling rate of -20°C/min, and then measured again at a temperature increase of 20°C/min. It refers to the endothermic peak temperature (Tm2).

Note that the liquid crystal polyester (
When polycondensing A), the above (I), (II), (II
In addition to the components constituting I) and (IV), 3,3'
- Aromatic dicarboxylic acids such as diphenyldicarboxylic acid, 3,4'-diphenyldicarboxylic acid, and 2,2'-diphenyldicarboxylic acid, alicyclic dicarboxylic acids such as hexahydroterephthalic acid, resorcinol, chlorohydroquinone, methylhydroquinone, bis Aromatic dihydroxy compounds such as (4-hydroxyphenyl) sulfone and their ethylene oxide adducts, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, 1,4-cyclohexanediol, 1,4- Aliphatic and cycloaliphatic diols such as cyclohexanedimethanol, aromatic hydroxycarboxylic acids such as m-oxybenzoic acid and 6-hydroxy-2-naphthoic acid, and p-aminophenol and p-aminobenzoic acid are used in the present invention. Further copolymerization can be carried out within a small proportion that does not impair the purpose.

Fillers (B) used in the present invention include inorganic fibers such as glass fibers, alumina fibers, silicon carbide fibers, ceramic fibers, asbestos fibers, gypsum fibers, metal fibers (such as stainless steel fibers), and carbon fibers. fibrous fillers and silicates such as wollastenite, sericite, kaolin, mica, clay, bentonite, asbestos, talc, alumina silicate, metal oxides such as alumina, silicon oxide, magnesium oxide, zirconium oxide, titanium oxide, Examples include powdery or granular fillers such as carbonates such as calcium carbonate, magnesium carbonate, and dolomite, sulfates such as calcium sulfate and barium sulfate, glass beads, boron nitride, silicon carbide, and Saroyan, which are hollow and (e.g., hollow glass fibers, glass microballoons, glass balloons, carbon balloons, etc.). Further, the above-mentioned reinforcing material may be used after being pretreated with a coupling agent such as a silane type or a titanium type, if necessary.

The amount of these fillers (B) added is in the range of 0 to 200 parts by weight, preferably 10 to 150 parts by weight, based on 100 parts by weight of the liquid crystal polyester (A). If the amount exceeds 200 parts by weight, the mechanical properties and moldability will deteriorate significantly, which is not preferable.

The silane-containing compound (C) used in the present invention is represented by the following general formula (i).

[0038]

[Chemical formula 9]

(However, n in the formula is an integer of 1 to 5, R
are CH3, C2 H5, C3 H7, C4 H9
represents one or more alkyl groups selected from ) Among these, γ-ureidoxypropyltriethoxysilane is most preferably used.

[0040] The amount added is 100% of liquid crystal polyester (A).
0.01 to 20 parts by weight, preferably 0.01 to 20 parts by weight.
05 to 15 parts by weight, more preferably 0.1 to 10 parts by weight. If the amount added is 20 parts by weight or more, fluidity will be poor and mechanical properties will be adversely affected, and if it is less than 0.01 part by weight, no substantial effect will be obtained, which is not preferable. It is also possible to use two or more types of γ-ureidoxypropyltriethoxysilane and other silane-containing compounds (eg, epoxysilane, isocyanate silane, etc.) in combination.

Furthermore, in the present invention, by using the silane coupling agent of the present invention in combination with an organic flame retardant, brominated polystyrene, brominated epoxy compound, brominated polycarbonate, brominated polyphenylene ether, etc.,
The effect of reducing mechanical anisotropy can be further increased.

The liquid crystal polyester composition of the present invention may contain antioxidants and heat stabilizers (for example, hindered phenol, hydroquinone, phosphites, and substituted products thereof) to the extent that the object of the present invention is not impaired. , UV absorbers (e.g. resorcinol, salicylates,
benzotriazole and benzophenone), lubricants and mold release agents (such as montanic acid and its salts, its esters, its half esters, stearyl alcohol, stearamide and polyethylene wax), dyes (such as nigrosine) and pigments (such as cadmium sulfide, phthalocyanine). Conventional additives such as colorants, plasticizers and antistatic agents, including colorants, plasticizers, carbon black, etc., and other thermoplastics can be added to impart desired properties.

The resin composition of the present invention is preferably produced by melt-kneading, and known methods can be used for melt-kneading. For example, using a Banbury mixer, rubber roll machine, kneader, single screw or twin screw extruder, etc.
The composition can be prepared by melt-kneading at a temperature of 250 to 370°C.

[0044]

[Examples] The present invention will be explained in detail with reference to Examples below.

Reference Example 1 994 parts by weight of p-hydroxybenzoic acid, 126 parts by weight of 4,4'-dihydroxybiphenyl, 960 parts by weight of acetic anhydride, 112 parts by weight of terephthalic acid, and polyethylene terephthalate 216 having an intrinsic viscosity of about 0.6 dl/g. Parts by weight were charged into a reaction vessel equipped with a stirring blade and a distillation tube, and acetic acid depolymerization was carried out under the following conditions.

[0046] First, the temperature was set at 100 to 250°C under a nitrogen gas atmosphere.
After reacting for 6 hours at 250-315°C for 1.5 hours, the pressure was reduced to 0.5 mmHg at 315°C for 2 hours, and the reaction was further carried out for 1 hour to complete the polycondensation. was distilled out to obtain a liquid crystal polyester having the following theoretical structural formula.

[0047]

[Chemical formula 10]

The melting point (Tm) of this polyester is 314
℃, and showed good optical anisotropy at 293°C or higher. The logarithmic viscosity of this polyester (measured at 60°C in pentafluorophenol at a concentration of 0.1 g/dl) is 1.9.
6 dl/g, and the melt viscosity at 324° C. and a shear rate of 1,000/sec was 910 poise.

Reference Example 2 994 parts by weight of p-hydroxybenzoic acid, 223 parts by weight of 4,4'-dihydroxybiphenyl, 147 parts by weight of 2,6-diacetoxynaphthalene, and terephthalene were placed in a reaction vessel equipped with a stirrer and a distillation tube. 299 parts by weight of acid and 1,077 parts by weight of acetic anhydride were charged, and acetic acid depolycondensation was carried out under the following conditions.

[0050] First, the temperature was set at 100 to 250°C under a nitrogen gas atmosphere.
After reacting for 5 hours at 250 to 330°C for 1.5 hours, the pressure was reduced to 0.5 mmHg at 330°C for 1.5 hours, and the reaction was further carried out for 1.0 hours to complete the polycondensation.
Approximately the theoretical amount of acetic acid was distilled out, and a liquid crystalline polyester having the following theoretical structural formula was obtained.

[0051]

[Chemical formula 11]

The liquid crystal initiation temperature of this polyester is 296
℃, and exhibited good optical anisotropy above this temperature. The logarithmic viscosity of this polyester (measured under the same conditions as Reference Example 1) was 4.9 dl/g. Further, the melt viscosity at 336° C. and a shear rate of 1,000/sec was 520 poise.

Examples 1 to 3 Glass fiber (B), γ-ureidoxypropyltriethoxysilane (Toray Dow Corning Silicone) were added to 100 parts of the liquid crystal polyester (A) obtained in Reference Example 1.
) (C) and brominated polystyrene "Pyrocheck" 68PB (Nissan Fellow Co., Ltd.) as a flame retardant.
) (D) were dry blended in the proportions listed in Table 1, and 314
The mixture was melt-kneaded using a 30 mmφ twin-screw extruder set at ℃ and then pelletized.

[0054] The pellets were processed using a Sumitomo Nestal injection molding machine Promat 40/25 (manufactured by Sumitomo Heavy Industries, Ltd.).
7 at a cylinder temperature of 324℃ and a mold temperature of 90℃.
A square plate measuring 0 x 70 x 2 mm was molded.

[0055] From this square plate, a 1/2" width was cut in the flow direction (MD) and the transverse direction (TD) of the resin, and AST
Measure the flexural modulus according to the MD790 standard, and
The ratio of the bending elastic modulus of /TD was determined as the mechanical anisotropy ratio.

Example 4 100 parts of the liquid crystal polyester obtained in Reference Example 2, 40 parts by weight of glass fiber, and γ-ureidoxypropyltriethoxysilane (Toray Dow Corning Silicone Co., Ltd.)
) 1 part by weight was dry blended, extruded, and molded at a temperature of 3.
70× under the same conditions as Example 1 except that the temperature was changed to 40°C.
A square plate of 70×2 mm was molded, and the ratio of MD/TD flexural modulus was measured.

Comparative Example 1 The liquid crystal polyester obtained in Reference Example 1 was molded under the same conditions as in Examples 1 to 3, and the ratio of the MD/TD flexural modulus of the square plate was measured.

Comparative Example 2 40 parts by weight of glass fiber was dry-blended with 100 parts by weight of the liquid crystal polyester obtained in Reference Example 1, and the mixture was extruded and molded under the same conditions as Examples 1 to 3 to determine the MD/TD of the square plate. The ratio of flexural modulus was measured.

Comparative Example 3 γ-ureidoxypropyltriethoxysilane was converted into γ-(
2-aminoethyl)aminopropyltrimethoxysilane (manufactured by Toray Dow Corning Silicone Co., Ltd.: S
Dry blending, extrusion, and molding were carried out using the same composition as in Example 1 except that the composition was changed to (H-6020). The bending elastic modulus of the obtained square plate was measured under the same conditions as in Example 1, and the ratio of MD/TD bending elastic modulus was measured.

[0060]

[Table 1]

It can be seen that compared to Comparative Examples 1 to 3, the resin compositions (Examples 1 to 4) to which the γ-ureidoxypropyltriethoxysilane of the present invention was added had smaller mechanical anisotropy. Furthermore, the resin composition (Example 3) to which a flame retardant was added had even smaller mechanical anisotropy.

[0062]

Effects of the Invention The liquid crystalline polyester resin composition of the present invention has a small mechanical anisotropy, so it can be used in various applications such as electrical and electronic parts that require dimensional accuracy.

Claims (1)

[Claims] [Claim 1] (A) The following structural units (I), (II
), (IV) or (I), (II), (III),
(B) 0 to 200 parts by weight of a filler and (C) 0 to 200 parts by weight of a silane-containing compound represented by the following general formula (i) based on 100 parts by weight of a liquid crystal polyester resin forming an anisotropic melt phase consisting of (IV) .01～
A liquid crystal polyester resin composition containing 20 parts by weight. [Chemical 1] (However, R1 in the formula represents one or more groups selected from [Chemical 2], and R2 represents a group selected from [Chemical 3]. In addition, the structural unit (IV) is It is substantially equimolar to the structural unit [(II) + (III)].) [Formula 4] (However, n in the formula is an integer of 1 to 5, R is CH3,
It represents one or more alkyl groups selected from C2 H5, C3 H7, and C4 H9. )