JPH1160927A - Thermotropic liquid crystal polymer composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject composition excellent in fluidity, usable in a low pressure injection molding and useful as a raw material for thin wall molding or element sealing by including a specific amount of terpene-based resin based on a thermotropic liquid crystal polymer. SOLUTION: This composition is obtained by including a terpene-based resin [e.g. a resin mainly containing a homopolymer of terpene-based compound, or a copolymer of terpene-based compound and polar compound (e.g. aromatic vinyl monomer), the copolymer comprising 3 to 20 monomer molecules] in a thermotropic liquid crystal monomer [e.g. a (co)polymer with a molecular weight of 2,000 to 200,000, pref. 10,000 to 100,000, containing >=5 mol.% of the monomer unit of the formula, pref. aromatic polyester] in the ratio of 0.5 to 10 wt.%, pref. 1 to 3 wt.% based on the whole composition.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermotropic liquid crystal polymer (hereinafter sometimes referred to as "LCP") which has excellent fluidity and can be injection molded at a low pressure.

[0002]

2. Description of the Related Art A wide variety of engineering plastics are commercially available, and resins having excellent heat resistance and mechanical strength are widely used in electric and electronic parts, automobile parts, precision machine parts, etc. according to their characteristics. ing. However, the demand for higher performance is increasing, and various materials are being studied.In particular, the thermotropic liquid crystal polymer composed of rigid molecular chains has low apparent viscosity during injection molding and good injection moldability. In addition, it has attracted attention because of its excellent mechanical properties, chemical resistance, heat resistance, nonflammability, low outgas pollution, and the like.

In recent years, there has been an increasing demand for replacing epoxy resin, which is a thermosetting resin, used as a resin material for encapsulating elements in fields such as electricity, electronics, and optics, with LCP. The production of a sealed part is usually performed by placing an element in a mold cavity of an injection molding machine and injection-injecting molten LCP into the remaining gap. However, in many cases, the pressure required for mold filling by injection injection (hereinafter sometimes referred to as “filling pressure”) is high,
The element may be deformed, damaged, broken, or the like, resulting in a product defect. In order to avoid this, it is necessary to lower the filling pressure of LCP. Similarly, in the case of thin-wall molding, a reduction in filling pressure is required.

[0004]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to reduce the filling pressure so as to reduce the filling pressure, thereby making it possible to use thermotropic material for thin-wall molding or as a sealing material for elements in the fields of electric, electronic and optical. It is to provide a liquid crystal polymer composition.

[0005]

The present invention has been completed by finding that the filling pressure of the thermotropic liquid crystal polymer can be reduced by adding a terpene resin. That is, the present invention provides a terpene-based resin of 0.5 to 1
The present invention relates to a thermotropic liquid crystal polymer composition containing 0% by weight. Hereinafter, the present invention will be further described.

The thermotropic liquid crystal polymer used in the present invention is a polymer that exhibits optical anisotropy in a molten state. Such a polymer has a property that the polymer molecular chains take a regular parallel arrangement in a molten state. The fact that the melt phase exhibits optical anisotropy can be confirmed by a normal polarization inspection method using an orthogonal polarizer. A general polymer becomes isotropic in a molten state, but when it shows anisotropy in a melting process, it changes from a solid phase to an isotropic phase through an anisotropic liquid crystal phase in a certain temperature range. In addition, mechanical anisotropy can be confirmed in the thermotropic liquid crystal polymer. That is, it is confirmed by the fact that the surface of the molded product is remarkably exfoliated and fibrillated when injection molding is performed, and the difference in physical properties between the direction of flow of the resin and the direction perpendicular thereto is large. Thermotropic liquid crystal polymers are generally made from monomers that are elongated, flat, rigid along the long chain of the molecule, and have multiple coaxial or parallel chain extension bonds.

The thermotropic liquid crystal polymer includes, for example, liquid crystalline polyesters, liquid crystalline polyesterimides, etc., and more specifically, (wholly) aromatic polyesters, polyester amides, polyester carbonates and the like. Preferred is a liquid crystalline polyester, which is included in the category of polyester as long as it contains a plurality of ester bonds in the molecule. Preferred polyesters are aromatic polyesters.

In the thermotropic liquid crystal polymer used in the present invention, a part of one polymer chain is composed of a polymer segment forming an anisotropic molten phase, and the remaining part does not form an anisotropic molten phase. Also included are polymers composed of polymer segments. Further, a composite of a plurality of thermotropic liquid crystal polymers is also included.

Representative examples of the monomers constituting the thermotropic liquid crystal polyester include (a) at least one kind of aromatic dicarboxylic acid, (b) at least one kind of aromatic hydroxycarboxylic acid compound, and (c) aromatic diol. At least one of (d) (d ₁ ) aromatic dithiol, (d ₂ ) aromatic thiophenol and (d ₃ ) aromatic thiol carboxylic acid compound,
And (e) at least one of aromatic hydroxylamine and aromatic diamine compounds. These may be used alone, but many are (a) and (c); (a) and (d); (a), (b) and (c); (a), (b) and ( e); or (a),
(B), (c) and (e).

The aromatic dicarboxylic acid compound (a) includes terephthalic acid, 4,4'-biphenyldicarboxylic acid, 4,4'-triphenyldicarboxylic acid, 2,6-naphthalenedicarboxylic acid, and 1,4- Naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, diphenyl ether-4,4'-dicarboxylic acid, diphenoxyethane-
4,4'-dicarboxylic acid, diphenoxybutane-4,4'-
Dicarboxylic acid, diphenylethane-4,4'-dicarboxylic acid, isophthalic acid, diphenylether-3,3'-dicarboxylic acid, diphenoxyethane-3,3'-dicarboxylic acid, diphenylethane-3,3'-dicarboxylic acid, 1,6
Aromatic dicarboxylic acids such as naphthalenedicarboxylic acid, or chloroterephthalic acid, dichloroterephthalic acid, bromoterephthalic acid, methylterephthalic acid, dimethylterephthalic acid, ethylterephthalic acid, methoxyterephthalic acid,
Alkyl, alkoxy or halogen substituents of the above aromatic dicarboxylic acids represented by ethoxy terephthalic acid and the like.

(B) The aromatic hydroxycarboxylic acid compounds include aromatic hydroxycarboxylic acids such as 4-hydroxybenzoic acid, 3-hydroxybenzoic acid, 6-hydroxy-2-naphthoic acid and 6-hydroxy-1-naphthoic acid. Carboxylic acid, or 3-methyl-4-hydroxybenzoic acid, 3,
5-dimethyl-4-hydroxybenzoic acid, 2,6-dimethyl-4-hydroxybenzoic acid, 3-methoxy-4-hydroxybenzoic acid, 3,5-dimethoxy-4-hydroxybenzoic acid, 6-hydroxy-5 Methyl-2-naphthoic acid, 6-hydroxy-5-methoxy-2-naphthoic acid, 2-chloro-4-hydroxybenzoic acid, 3-chloro-4-hydroxybenzoic acid, 2,3-dichloro-4-hydroxybenzoic acid Acid, 3,5-dichloro-4-hydroxybenzoic acid, 2,5-dichloro-4-hydroxybenzoic acid, 3-bromo-4-hydroxybenzoic acid, 6-hydroxy-5-chloro-2-naphthoic acid, 6 -Hydroxy-
7-chloro-2-naphthoic acid, 6-hydroxy-5,7
And alkyl-, alkoxy-, or halogen-substituted aromatic hydroxycarboxylic acids such as -dichloro-2-naphthoic acid.

(C) As the aromatic diol, 4,4′-
Dihydroxybiphenyl, 3,3′-dihydroxybiphenyl, 4,4′-dihydroxyterphenyl, hydroquinone, resorcin, 2,6-naphthalenediol,
4'-dihydroxydiphenyl ether, bis (4-hydroxyphenoxy) ethane, 3,3'-dihydroxydiphenyl ether, 1,6-naphthalenediol, 2,2-
Bis (4-hydroxyphenyl) propane, aromatic diol such as bis (4-hydroxyphenyl) methane, or chlorohydroquinone, methylhydroquinone, tert-
Butylhydroquinone, phenylhydroquinone, methoxyhydroquinone, phenoxyhydroquinone, 4-
Alkyl, alkoxy or halogen-substituted aromatic diols such as chlororesorcin and 4-methylresorcin.

(D ₁ ) Examples of the aromatic dithiol include benzene-1,4-dithiol, benzene-1,3-dithiol, 2,6-naphthalene-dithiol, and 2,7-naphthalene-dithiol. (D ₂ ) Examples of the aromatic thiophenol include 4-mercaptophenol, 3-mercaptophenol, and 6-mercaptophenol. (D ₃ ) Examples of the aromatic thiolcarboxylic acid include 4-mercaptobenzoic acid, 3-mercaptobenzoic acid, 6-mercapto-2-naphthoic acid, and 7-mercapto-2-naphthoic acid.

(E) As the aromatic hydroxylamine or aromatic diamine compound, 4-aminophenol, N-methyl-4-aminophenol, 1,4-phenylenediamine, N-methyl-1,4-phenylenediamine , N, N'-dimethyl-1,4-phenylenediamine, 3-aminophenol, 3-methyl-4-aminophenol, 2-chloro-4-aminophenol, 4-amino-1-naphthol, 4-amino- 4'-hydroxybiphenyl, 4-amino-4'-hydroxydiphenyl ether, 4-amino-4'-hydroxydiphenylmethane, 4-amino-4'-hydroxydiphenyl sulfide, 4,4'-diaminodiphenyl sulfide (thiodianiline), , 4'-diaminodiphenyl sulfone,
2,5-diaminotoluene, 4,4′-ethylenedianiline, 4,4′-diaminodiphenoxyethane, 4,4′-diaminodiphenylmethane (methylenedianiline),
4'-diaminodiphenyl ether (oxydianiline) and the like.

The thermotropic liquid crystal polyester used in the present invention can be produced from the above monomers by various ester forming methods such as a melt acidification method and a slurry polymerization method. Suitable thermotropic liquid crystal polyesters for use in the present invention have a molecular weight of about 2,000 to
200,000, preferably about 10,000-100,0
00. The value of the molecular weight can be determined, for example, by measuring end groups of the compressed film by infrared spectroscopy. GP, which is a general measurement method performed in a solution state
C can also be used.

Among the thermotropic liquid crystal polymers obtained from these monomers, an aromatic polyester which is a (co) polymer containing a monomer unit represented by the following general formula [I] as an essential component is preferable. Those containing about 5 mol% or more of the above monomer units are preferred.

[0017]

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A particularly preferred aromatic polyester for use in the present invention is a compound represented by the following general formula [II] having a repeating unit having a structure derived respectively from three compounds of p-hydroxybenzoic acid, phthalic acid and dihydroxybiphenyl.
Is a polyester represented by In this polyester, part or all of the repeating units having a structure derived from dihydroxybiphenyl can be replaced with repeating units derived from dihydroxybenzene. Further, a polyester represented by the following general formula [III] having a repeating unit having a structure derived from two compounds of p-hydroxybenzoic acid and hydroxynaphthalenecarboxylic acid is also preferably used.

[0019]

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The terpene resin used in the present invention is a homopolymer of a terpene compound or a copolymer of a terpene compound and a polar compound.
It refers to a polymer mainly composed of a polymer composed of individual monomer molecules. In addition, these hydrogenated products can also be mentioned. Examples of the polar compound copolymerizable with the terpene compound include an aromatic vinyl monomer, a phenol compound, and an unsaturated carboxylic acid. These terpene-based compound homopolymers or terpene-based compound and polar compound-based copolymers can be used in an organic solvent in the presence of a Friedel-Crafts catalyst in the presence of a terpene-based compound alone or a terpene-based compound and an aromatic compound. It is obtained by reacting a vinyl monomer, a phenolic compound, an unsaturated carboxylic acid or a mixture thereof. These hydrogenated products can be produced by a known hydrogenation process.

As the terpene compound, α-pinene,
Examples include β-pinene, limonene, α-terpinene, β-terpinene, γ-terpinene, dipentene and the like. Examples of the aromatic vinyl monomer include styrene, α-methylstyrene, and vinyl toluene. Examples of the phenol compound include phenol, cresol, and bisphenol A. Examples of unsaturated carboxylic acids include α, β-unsaturated carboxylic acids and anhydrides thereof, for example, maleic anhydride. In the case of a copolymer of a terpene compound and an unsaturated carboxylic acid,
In addition to lowering the filling pressure, it is possible to obtain the effect of improving the bonding strength with metal.

As the terpene resin thus obtained, for example, “YS Resin PX”, “YS Resin TO”, “YS Resin T” from Yashara Chemical Co., Ltd.
Products having trade names such as “R”, “Cloarin”, “YS Polystar”, “Mighty Ace”, “YP-90”, and “TM-60” are commercially available and can be easily obtained.

A petroleum resin having an alicyclic structure obtained by hydrogenating an aromatic ring of a C ₉ petroleum resin has a structure similar to that of a so-called terpene resin, and the same effect is expected. . Thus, the terpene resin used in the present invention also include hydrogenated C ₉ petroleum resin. Examples of such a petroleum resin include “Alcon P” (trade name, fully hydrogenated product) and “Alcon M” (trade name, partial hydrogen), which are alicyclic saturated hydrocarbon resins manufactured by Arakawa Chemical Co., Ltd. Chemical)
Can be obtained.

Of these, those containing as a main component a polymer of 3 to 10 molecules obtained by reacting a terpene compound with a phenol compound are preferred. The compounding amount of the terpene resin used in the present invention is 0.5 to 10% by weight, preferably 1 to 3% by weight, based on the whole composition. If the amount is less than 0.5% by weight, the effect of lowering the filling pressure is poor.

The reason why the effects of the present invention can be obtained by blending a terpene resin is not clear, but the terpene resin can be easily thermostated due to the terpene structure or the affinity of the hydroxyl group of the phenolic compound contained as a component. This is considered to be due to penetration between the tropic liquid crystal polymer molecules to improve the slip between the molecules. Therefore, among terpene resins, those containing a polymer obtained by reacting a terpene compound with a phenol compound as a main component are preferable.

The composition of the present invention may further contain other resins. The other resin to be blended may be any of a thermoplastic column resin and a thermosetting resin, but is preferably a polyamide resin, a polycarbonate resin, a polyethylene terephthalate resin, a polybutylene terephthalate resin, a polyphenylene sulfide resin,
So-called thermoplastic engineering plastics such as polyethersulfone resin, polysulfone resin, polyetherketone resin, and polyetheretherketone resin are exemplified. The blending amount of the other thermoplastic resin is
The amount is 1 to 200 parts by weight, preferably 1 to 100 parts by weight, more preferably 1 to 50 parts by weight per 100 parts by weight of the LCP used in the present invention.

Further, a reinforcing agent or a filler can be added to the resin composition of the present invention in order to improve heat resistance and mechanical properties. Specific examples of reinforcing agents or fillers include fibrous, powdery and mixtures of both. Examples of the fibrous reinforcing agent include inorganic fibers such as glass fibers, shirasu glass fibers, alumina fibers, silicon carbide fibers, ceramic fibers, asbestos fibers, gypsum fibers, and metal fibers (eg, stainless steel fibers) and carbon fibers. . In addition, as powdery and granular reinforcing agents, wollastonite, sericite, kaolin, mica, clay,
Silicates such as bentonite, asbestos, talc, alumina silicate, alumina, metal oxides such as silicon oxide, magnesium oxide, zirconium oxide, titanium oxide, carbonates such as calcium carbonate, magnesium carbonate, dolomite, calcium sulfate, pyrosulfuric acid Calcium, sulfate such as barium sulfate, glass beads, boron nitride,
Silicon carbide, Saroyan and the like can be mentioned. These may be hollow, and examples thereof include hollow glass fibers, glass microballoons, shirasu balloons, and carbon balloons. The reinforcing agent may be used after being subjected to a preliminary treatment with a silane-based or titanium-based coupling agent, if necessary. 80% by weight or less, preferably 70% by weight or less of the reinforcing composition, filler and the like can be blended with respect to the whole composition.

Further, the resin composition of the present invention contains an antioxidant, a heat stabilizer, an ultraviolet absorber, a skeleton and a release agent, a coloring agent containing a dye or a pigment, a flame retardant, a plasticizer, an antistatic agent. Ordinary additives such as the above can be added to impart predetermined characteristics. Examples of the heat stabilizer include hindered phenol, hydroquinone, phosphites, and substituted products thereof. As the ultraviolet absorber, for example, resorcinol, salicylate, benzotriazole, benzophenone and the like are used. Nitrosine or the like can be added as a dye, and cadmium sulfide, phthalocyanine, carbon black, or the like can be added as a pigment.

In the present invention, a conventionally known method can be used to mix the LCP and the terpene resin. For example, a method of heating and melting and mixing using an extruder,
A method of mixing a terpene-based resin in the process of melt-synthesizing LCP may be used. In the present invention, a method of melt-kneading with an extruder is particularly preferred because it is simple and can be uniformly mixed. At this time, a small amount of a solvent can be appropriately added. As a device for performing the melt kneading, a Banbury mixer, a static mixer roller, a kneader, or the like can be used continuously or batchwise, but it is effective to use a single-screw extruder or a twin-screw extruder continuously. is there.

As a method of mixing the other thermoplastic resin, the thermoplastic resin may be mixed simultaneously with the production of the composition of the present invention, or may be mixed with the composition of the present invention prepared in advance. Alternatively, the terpene-based resin may be mixed after the other resin is mixed with the LCP in advance.

[0031]

The present invention will be described below in detail with reference to examples. First, materials used in Examples and Comparative Examples will be described. <Materials Used> (1) Thermotropic liquid crystal polymer (LCP) LCP polymerized from phthalic acid, isophthalic acid, 4-hydroxybenzoic acid and 4,4-dihydroxybiphenyl
Was used. The molar ratio of each of the above components is 0.75 / 0.7.
25/3/1. Observation of optical anisotropy using a polarizing microscope equipped with a hot stage revealed that the temperature was 340 ° C.
Optical anisotropy was exhibited in the above molten state. (2) Terpene resin ・ Mighty Ace G-150 (trade name) A hydrogenated product of a Friedel-Crafts reaction product of a terpene compound and phenol, manufactured by Yashara Chemical Corporation. Abbreviated as "G-150" in the table.・ YP-90 (trade name) Terpene-diphenol resin, Yashara Chemical Co., Ltd.
Made. -TM-60 (trade name) Diels-Alder reaction product of a terpene compound and maleic anhydride, manufactured by Yashara Chemical Corporation.

<Method of Measuring Minimum Filling Pressure> The minimum filling pressure at the time of injection molding a test piece having a specific shape is determined. FIG.
(A) and (b) are a side view and a front view, respectively, of a test piece molded for minimum filling pressure measurement. A resin material is injected from a tab gate of a mold and injection molded to form a rectangular test piece 1. The illustrated test piece 1 is taken out of a mold and has a tab gate portion 2. The dimensions of the test piece were a = 100 mm and b
= 20 mm, and the thickness (t) was made variable in the range of 0.5 to 2 mm, and was set to the value shown in the table according to each composition. In addition, the value of the minimum filling pressure is 100 corresponding to the value of the comparative example.
And expressed as a relative value (%).

<Examples 1 to 11, Comparative Examples 1 to 3> Using a twin-screw extruder, the temperature of the kneading section was set to 350 ° C.
The raw materials shown in Tables 1 and 2 were melt-mixed and extruded to produce pellets. Injection molding was performed using the pellets, and the minimum filling pressure was determined. Tables 1 and 2 show the above results. In Table 1, the minimum filling pressure was set to 100 in Comparative Example 1, and in Table 2, the values of Comparative Example 2 were obtained for Examples 7 and 8, and the values of Comparative Example 3 were obtained for Examples 9 to 11. Each was set to 100.

[0034]

[Table 1]

[0035]

[Table 2]

[0036]

According to the present invention, by adding a terpene compound resin to LCP, it is possible to reduce the minimum filling pressure in mold filling, and the application range of LCP, particularly as a sealing material, The range of application can be expanded.

[Brief description of the drawings]

FIG. 1 (a) is a side view of a test piece molded for measuring a minimum filling pressure, and FIG. 1 (b) is a front view thereof.

[Explanation of symbols]

 1 Test piece 2 Tab gate

Claims (1)

[Claims] 1. A thermotropic liquid crystal polymer composition containing 0.5 to 10% by weight of a terpene resin.