JP2007138143A - Liquid crystalline resin composition and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a highly rigid material, in which fine particles are singly dispersed in a liquid crystalline resin without causing aggregation, having high storage elastic modulus even in non-orientation state, lowered in crystallization rate though fine particles are formulated therein. <P>SOLUTION: The liquid crystalline resin is obtained by formulating 100 pts.wt. liquid crystalline polyester with 1-5 pts.wt. fine particles having ≥0.08 μm and <0.2 μm average particle diameter. The fine particles are preferably those of spherical amorphous silica and are preferably kneaded at ≥1MPa resin pressure when producing a resin composition. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention has a high storage elastic modulus even in a non-oriented state in which the fine particles are monodispersed without agglomerating into a liquid crystalline resin, and excellent moldability with a reduced crystallization speed despite the incorporation of fine particles. The present invention relates to a liquid crystal resin composition optimal as a highly rigid material and a method for producing the same.

  In recent years, there has been an increasing demand for higher performance of plastics, and many polymers with various new performances have been developed and put on the market. Among them, optically anisotropic liquid crystals characterized by parallel arrangement of molecular chains Liquid crystalline polymers such as water-soluble polyesters are attracting attention because of their excellent moldability and mechanical properties, and demand is growing for injection molded products, mainly for electrical and electronic parts.

  On the other hand, the liquid crystalline polyester has a large thickness dependency of the elastic modulus, and when it is thin and highly oriented, a high elastic modulus can be obtained. Since the rate is greatly reduced and the anisotropy is large, there is a problem that it is difficult to use as a large structural material.

Therefore, from the viewpoint of reducing the anisotropy, and for improving the surface smoothness, etc., investigations have been made so far for blending spherical silica particles alone or in combination with other fillers. (For example, refer to Patent Documents 1 and 2).
International Publication No. 95/25770 (first page, Example 30) Japanese Patent Laying-Open No. 2003-192878 (first page)

  In these patent documents, an effect of anisotropy and surface smoothness is obtained by blending a large amount of silica fine particles. As described in Patent Document 2, an aggregate of silica fine particles of 60 μm or more is obtained. It is easy to do this, and in Patent Document 2, the silica microparticles of 0.5 μmφ are used and special pretreatment is performed to suppress aggregation. However, the single-particle cohesion force of the silica microparticles increases as the particle diameter decreases. In the past, silica fine particles of less than 0.2 μm caused aggregation when incorporated, and could not be used because they caused significant thickening and uneven physical properties.

  The present invention has been made in view of the background of such prior art, and as a result of studying monodispersion of fine particles, an object of the present invention is to provide a liquid crystalline resin composition in which fine particles having an average particle diameter of less than 0.2 μm are monodispersed.

  As a result of intensive studies to solve the above problems, the present inventors have succeeded in monodispersing fine particles having a size of 0.08 μm or more and less than 0.2 μm in a liquid crystalline polyester, and anisotropy reduction expected by the composition In addition to the high effect of addition of a smaller amount of surface smoothness and surface smoothness, it is a characteristic contrary to the known effect of conventional particle addition, that is, special effects such as a decrease in crystallization rate and a significant increase in storage elastic modulus. The headline, the present invention has been reached.

That is, the present invention is (1) a liquid crystalline resin composition comprising 1 to 5 parts by weight of fine particles having an average particle size of 0.08 or more and less than 0.2 μm in 100 parts by weight of a liquid crystalline polyester,
(2) The liquid crystalline resin composition according to the above (1), wherein the fine particles are silica fine particles,
(3) The liquid crystalline resin composition according to the above (2), wherein the silica fine particles are composed of amorphous silica.
(4) The liquid crystalline resin composition according to the above (2) or (3), wherein the silica fine particles are spherical silica.
(5) The liquid crystalline resin composition according to any one of (1) to (4) above, wherein the fine particles are monodispersed,
(6) The liquid crystalline polyester is composed of structural units (I) to (V), and the structural unit (I) is 65 to 80 mol% based on the total of the structural units (I), (II), and (III). The structural unit (II) is 60 to 75 mol% based on the total of the structural units (II) and (III), and the structural unit (IV) is based on the total of the structural units (IV) and (V). (1) to (5), wherein the total of structural units (II) and (III) and the total of (IV) and (V) are substantially equimolar. ) The liquid crystalline resin composition according to any one of

(7) A liquid crystalline resin composition obtained by further blending 5 to 200 parts by weight of a filler with the liquid crystalline resin composition according to any one of (1) to (6) above, and (8) a liquid crystalline resin and silica. The present invention provides a method for producing a liquid crystalline resin composition according to any one of (1) to (7) above, wherein the resin pressure is 1 MPa or more when kneading the fine particles.

  The liquid crystalline resin composition of the present invention is a molded article or sheet having excellent surface appearance (color tone) and mechanical properties, heat resistance, and flame retardancy by a molding method such as normal injection molding, extrusion molding or press molding. It can be processed into pipes, films, fibers and the like. Especially, since it is excellent in thin-wall rigidity and thin-wall fluidity, it is suitable for electric / electronic component applications that are being used with thin-wall molded products having a portion of 0.2 mm or less obtained by injection molding.

  The liquid crystalline polyester of the present invention is a polyester capable of forming an anisotropic melt phase, and includes, for example, aromatic oxycarbonyl units, aromatic and / or aliphatic dioxy units, aromatic and / or aliphatic dicarbonyl units, and the like. It is a liquid crystalline polyester composed of selected structural units and forming an anisotropic molten phase.

  Examples of the aromatic oxycarbonyl unit include a structural unit generated from p-hydroxybenzoic acid, 6-hydroxy-2-naphthoic acid, and the like, and examples of the aromatic and / or aliphatic dioxy unit include 4,4′- Dihydroxybiphenyl, hydroquinone, 3,3 ′, 5,5′-tetramethyl-4,4′-dihydroxybiphenyl, t-butylhydroquinone, phenylhydroquinone, 2,6-dihydroxynaphthalene, 2,7-dihydroxynaphthalene, 2, Structural units formed from 2-bis (4-hydroxyphenyl) propane and 4,4′-dihydroxydiphenyl ether, ethylene glycol, 1,3-propylene glycol, 1,4-butanediol, aromatic and / or aliphatic di Examples of the carbonyl unit include terephthalate. Acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, 4,4′-diphenyldicarboxylic acid, 1,2-bis (phenoxy) ethane-4,4′-dicarboxylic acid, 1,2-bis (2-chlorophenoxy) ) Structural units generated from ethane-4,4′-dicarboxylic acid and 4,4′-diphenyl ether dicarboxylic acid, adipic acid, sebacic acid and the like.

  Specific examples of the liquid crystalline polyester include a liquid crystalline polyester composed of a structural unit generated from p-hydroxybenzoic acid and 6-hydroxy-2-naphthoic acid, a structural unit generated from p-hydroxybenzoic acid, and 6-hydroxy-2. A structural unit produced from naphthoic acid, a liquid crystalline polyester comprising a structural unit produced from an aromatic dihydroxy compound, an aromatic dicarboxylic acid and / or an aliphatic dicarboxylic acid, a structural unit produced from p-hydroxybenzoic acid, 4, 4 A liquid crystalline polyester comprising a structural unit produced from a structural unit produced from '-dihydroxybiphenyl, an aromatic dicarboxylic acid such as terephthalic acid or isophthalic acid and / or an aliphatic dicarboxylic acid such as adipic acid or sebacic acid, p-hydroxybenzoic acid Structural units generated from acids, 4,4 ' Liquid crystalline polyester comprising structural units generated from dihydroxybiphenyl, structural units generated from hydroquinone, aromatic dicarboxylic acids such as terephthalic acid and isophthalic acid and / or structural units generated from aliphatic dicarboxylic acids such as adipic acid and sebacic acid , A structural unit produced from p-hydroxybenzoic acid, a structural unit produced from ethylene glycol, a liquid crystalline polyester comprising a structural unit produced from terephthalic acid and / or isophthalic acid, a structural unit produced from p-hydroxybenzoic acid, ethylene A liquid crystalline polyester comprising a structural unit produced from glycol, a structural unit produced from 4,4′-dihydroxybiphenyl, a structural unit produced from an aliphatic dicarboxylic such as terephthalic acid and / or adipic acid or sebacic acid, p-hydride Structural units generated from xylbenzoic acid, structural units generated from ethylene glycol, structural units generated from aromatic dihydroxy compounds, structures generated from aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, and 2,6-naphthalenedicarboxylic acid Examples thereof include liquid crystalline polyester composed of units.

  Particularly preferred are liquid crystalline polyesters composed of the following structural units (I), (II), (III), (IV) and (V).

  The structural unit (I) is a structural unit generated from p-hydroxybenzoic acid, the structural unit (II) is a structural unit generated from 4,4′-dihydroxybiphenyl, and the structural unit (III) is generated from hydroquinone. The structural unit, the structural unit (IV) represents a structural unit produced from terephthalic acid, and the structural unit (V) represents a structural unit produced from isophthalic acid.

  The structural unit (I) is 65 to 80 mol%, more preferably 68 to 75 mol%, based on the total of the structural units (I), (II) and (III). Moreover, structural unit (II) is 60 to 75 mol% with respect to the sum total of structural units (II) and (III), More preferably, it is 65 to 73 mol%. The structural unit (IV) is 60 to 92 mol%, preferably 60 to 70 mol%, more preferably 62 to 68 mol%, based on the total of the structural units (IV) and (V). .

  In particular, when the structural unit (IV) is 62 to 68 mol% with respect to the total of the structural units (IV) and (V), the moldability, which is a characteristic of the present invention, is preferably expressed in a balanced manner.

  The sum of structural units (II) and (III) and (IV) and (V) is substantially equimolar, but an excess of carboxylic acid component or hydroxyl component is added to control the end groups of the polymer. May be. That is, “substantially equimolar” means that the unit constituting the polymer main chain excluding the terminal is equimolar, but the unit constituting the terminal is not necessarily equimolar.

  There is no restriction | limiting in particular in the manufacturing method of the said liquid crystalline polyester used in this invention, It can manufacture according to the well-known polyester polycondensation method.

For example, in the production of the liquid crystalline polyester, the following production method is preferred.
(1) A method for producing a liquid crystalline polyester from p-acetoxybenzoic acid and 4,4′-diacetoxybiphenyl, diacetoxybenzene, terephthalic acid and isophthalic acid by a deacetic acid condensation polymerization reaction.
(2) p-hydroxybenzoic acid and 4,4′-dihydroxybiphenyl, hydroquinone, terephthalic acid, isophthalic acid are reacted with acetic anhydride to acylate the phenolic hydroxyl group, and then the liquid crystalline polyester is subjected to deacetic acid polycondensation reaction. How to manufacture.
(3) A method for producing a liquid crystalline polyester from a phenyl ester of p-hydroxybenzoic acid and 4,4′-dihydroxybiphenyl, hydroquinone, terephthalic acid, and diphenyl ester of isophthalic acid by a dephenol polycondensation reaction.
(4) A predetermined amount of diphenyl carbonate is reacted with p-hydroxybenzoic acid and aromatic dicarboxylic acid such as terephthalic acid and isophthalic acid to form a diphenyl ester, and then aromatics such as 4,4′-dihydroxybiphenyl and hydroquinone. A method for producing a liquid crystalline polyester by adding a group dihydroxy compound and dephenol polycondensation reaction.

  Among them, p-hydroxybenzoic acid and 4,4′-dihydroxybiphenyl, hydroquinone, terephthalic acid, isophthalic acid are reacted with acetic anhydride to acylate the phenolic hydroxyl group, and then the liquid crystalline polyester is obtained by deacetic acid polycondensation reaction. The manufacturing method is preferred.

  Furthermore, the total amount used of 4,4'-dihydroxybiphenyl and hydroquinone and the total amount used of terephthalic acid and isophthalic acid are substantially equimolar. The amount of acetic anhydride used is preferably 1.15 equivalents or less, more preferably 1.10 equivalents or less, of the total of the phenolic hydroxyl groups of p-hydroxybenzoic acid, 4,4′-dihydroxybiphenyl and hydroquinone. Preferably, the lower limit is 1.0 equivalent or more.

  When the liquid crystalline polyester of the present invention is produced by a deacetic acid polycondensation reaction, a melt polymerization method in which the polycondensation reaction is completed by reacting under reduced pressure at a temperature at which the liquid crystalline polyester melts is preferable. For example, in a reaction vessel having a predetermined amount of p-hydroxybenzoic acid and 4,4′-dihydroxybiphenyl, hydroquinone, terephthalic acid, isophthalic acid, acetic anhydride, a stirring blade, a distillation pipe, and a discharge port at the bottom. There is a method in which the reaction is completed after charging and heating under stirring in a nitrogen gas atmosphere to acetylate the hydroxyl group, raising the temperature to the melting temperature of the liquid crystalline polyester, and performing polycondensation under reduced pressure. The conditions for the acetylation are usually 130 to 300 ° C., preferably 135 to 200 ° C., usually 1 to 6 hours, preferably 140 to 180 ° C. for 2 to 4 hours. The polycondensation temperature is a melting temperature of the liquid crystalline polyester, for example, in the range of 250 to 350 ° C., and preferably a melting point of the liquid crystalline polyester + 10 ° C. or higher. The degree of vacuum during polycondensation is usually 0.1 mmHg (13.3 Pa) to 20 mmHg (2660 Pa), preferably 10 mmHg (1330 Pa) or less, more preferably 5 mmHg (665 Pa) or less. In addition, although acetylation and polycondensation may be performed continuously in the same reaction vessel, acetylation and polycondensation may be performed in different reaction vessels.

The obtained polymer is pressurized in the reaction vessel to, for example, approximately 1.0 kg / cm ² (0.1 MPa) at a temperature at which it melts, and discharged in a strand form from the discharge port provided in the lower portion of the reaction vessel. Can do. The melt polymerization method is an advantageous method for producing a uniform polymer, and an excellent polymer with less gas generation can be obtained, which is preferable.

  When producing the liquid crystalline polyester of the present invention, the polycondensation reaction can be completed by a solid phase polymerization method. For example, the polymer or oligomer of the liquid crystalline polyester of the present invention is pulverized by a pulverizer and the melting point of the liquid crystalline polyester is −5 ° C. to the melting point −50 ° C. (for example, 200 to 300 ° C.) under a nitrogen stream or under reduced pressure. A method of heating in the range for 1 to 50 hours, polycondensing to a desired degree of polymerization, and completing the reaction can be mentioned. Solid phase polymerization is an advantageous method for producing polymers with a high degree of polymerization.

  The polycondensation reaction of the liquid crystalline polyester proceeds even without a catalyst, but metal compounds such as stannous acetate, tetrabutyl titanate, potassium acetate and sodium acetate, antimony trioxide, and magnesium metal can also be used.

  The liquid crystalline polyester of the present invention preferably has a number average molecular weight of 3,000 to 25,000, more preferably 5,000 to 20,000, and more preferably 8,000 to 18,000. .

  The number average molecular weight can be measured by GPC-LS (gel permeation chromatography-light scattering) method using a solvent in which liquid crystalline polyester is soluble.

  The melt viscosity of the liquid crystalline polyester in the present invention is preferably 1 to 200 Pa · s, more preferably 10 to 200 Pa · s, and still more preferably 10 to 100 Pa · s.

  The melt viscosity is a value measured by a Koka flow tester under the condition of melting point of liquid crystalline polyester + 10 ° C. and shear rate of 1,000 / s.

  In the present invention, the melting point (Tm) refers to the endothermic peak temperature (Tm1) observed when the polymer having been polymerized is measured under the temperature rising condition from room temperature to 20 ° C./min in differential calorimetry. , After being held at a temperature of Tm1 + 20 ° C. for 5 minutes, once cooled to room temperature under a temperature decrease condition of 20 ° C./min, and then endothermic peak temperature (Tm2) observed when measured again under a temperature increase condition of 20 ° C./min Point to.

  The fine particles used in the present invention have an average particle size of 0.08 μm or more and less than 0.2 μm.

  The average particle size referred to here is the number average particle size.

  The number average particle size is calculated, for example, by measuring the ash content obtained by baking the composition with a laser diffraction particle size distribution meter, or by measuring any 50 particles by observing an arbitrary cross section of the composition with an electron microscope. be able to.

  About an average particle diameter, it is essential that it is 0.08 micrometer or more and less than 0.2 micrometer, Preferably it is 0.1-0.2 micrometer.

  When the average particle size is in the above range, it is preferable because a nano effect is exhibited and a significant improvement in storage elastic modulus, which is an effect of the present invention, is obtained.

  When the average particle size is 0.2 μm or more, the nano effect is hardly exhibited, and when the average particle size is less than 0.08 μm, the single product has a strong cohesion. Since it is not dispersed, the effects of the present invention cannot be obtained.

  The particle size here means the particle size in the composition of the particles. When the particles before blending are coated with a polymer, a coupling agent, etc., only the particles excluding these coating layers are used. The diameter.

  Specific fine particles include mainly inorganic fine particles. Examples of inorganic fine particles include metal fine particles, mineral particles, micro glass beads, micro glass balloons, and silica fine particles.

  Examples of the metal fine particles include molybdenum disulfide, titanium oxide, alumina, zirconia, ceramic, zinc oxide, strontium oxide, barium sulfate, calcium polyphosphate, calcium phosphate, aluminum borate, potassium titanate, barium titanate, and silicon nitride. Examples of the mineral particles include mica, talc, kaolin, calcium carbonate, shirasu balloon, clay, and wollastonite.

  Among these, titanium oxide, alumina, mica, talc, and silica fine particles are preferable, and silica fine particles are particularly preferable. The silica fine particles may be crystalline silica or amorphous silica, but amorphous silica is preferred, and synthetic silica is more preferred than mineral.

  Examples of the synthesis method include a sol-gel method, a heat melting method, and a VMC method, and the heat melting method is preferable.

  The shape may be granular, plate-like, or fibrous, but is preferably granular, of which spherical particles are preferred, and true spherical particles are particularly preferred. The sphericity is not particularly limited, but the major axis / minor axis ratio is preferably 0.95 to 1.05, more preferably 0.99 to 1.01, and most preferably 0.999 to 1.001. preferable.

  Regardless of the shape, the average of the longest diameters is defined as the average particle diameter.

  The measurement of the sphericity can be calculated by measuring the major axis and minor axis of an arbitrary particle cross section by observing an arbitrary cross section of the composition with an electron microscope.

  The fine particles of the present invention can be further improved in dispersibility in the resin by surface treatment or the like, but may cause primary aggregation depending on the treatment, and is not essential.

  The surface treatment may be performed on the particles in advance or at the same time when blended with the liquid crystalline polyester. When the particles are pretreated, for example, a method of spraying a solution of a surface treatment agent onto the particles is used. The concentration of the solution is preferably less than 5%, more preferably less than 1%.

  As the surface treatment agent, a titanate coupling agent, a silane coupling agent, or the like can be used. The functional group of the silane coupling agent is preferably an epoxy group, an amino group, an oxazolinyl group, an alkoxy group, a carboxyl group, or the like.

  The amount of fine particles in the present invention can be up to 100 parts by weight with respect to 100 parts by weight of the liquid crystalline polyester, but is preferably 1 to 5 parts by weight, and more preferably 1 to 3 parts by weight.

  If the blending amount is less than 1 part by weight, the effect is small, and if it is more than 5 parts by weight, the aggregate formation rate is increased, which is not preferable.

  The liquid crystalline resin composition of the present invention includes mica, talc, kaolin, silica (spherical, pulverized product), glass beads, glass flakes, glass microballoons, clay, molybdenum disulfide, wollastonite, calcium carbonate, titanium oxide, Among powdered, granular or plate-like fillers such as zinc oxide, calcium polyphosphate and graphite, if the average particle diameter is more than 0.2 μm and not more than 1.5 μm, the characteristics are not significantly affected. Can be blended.

  In order to ensure fluidity, it is preferable to use together spherical silica and talc having an average particle size of 0.5 to 1.0 μm.

  The above filler can also be used by treating the surface thereof with a known coupling agent (for example, silane coupling agent, titanate coupling agent, etc.) or other surface treatment agents.

  In the present invention, in order to impart mechanical strength and other characteristics of the liquid crystalline polyester, it is possible to further blend fillers other than those described above. The filler is not particularly limited, but fillers such as a fiber, a plate, a powder, and a granule can be used. Specifically, for example, glass fibers, PAN and pitch carbon fibers, stainless fibers, metal fibers such as aluminum fibers and brass fibers, organic fibers such as aromatic polyamide fibers and liquid crystalline polyester fibers, gypsum fibers, ceramic fibers , Asbestos fiber, zirconia fiber, alumina fiber, silica fiber, titanium oxide fiber, silicon carbide fiber, rock wool, potassium titanate whisker, barium titanate whisker, aluminum borate whisker, silicon nitride whisker, etc. Powder, granular or plate-like filling of wood, mica, talc, kaolin, silica, glass beads, glass flakes, glass microballoons, clay, molybdenum disulfide, wollastonite, titanium oxide, zinc oxide, calcium polyphosphate and graphite Material And the like. The above-mentioned filler used in the present invention can be used by treating the surface thereof with a known coupling agent (for example, a silane coupling agent, a titanate coupling agent, etc.) or other surface treatment agents. .

  Among these fillers, glass fiber is particularly preferably used from the viewpoint of balance between availability and mechanical strength. The type of glass fiber is not particularly limited as long as it is generally used for reinforcing resin, and can be selected from, for example, long fiber type or short fiber type chopped strands and milled fibers. Two or more of these can be used in combination. As the glass fiber used in the present invention, a weakly alkaline glass fiber is excellent in terms of mechanical strength and can be preferably used. The glass fiber is preferably treated with an epoxy-based, urethane-based, acrylic-based coating or sizing agent, and epoxy-based is particularly preferable. Further, it is preferably treated with a silane-based or titanate-based coupling agent or other surface treatment agent, and an epoxysilane or aminosilane-based coupling agent is particularly preferable.

  The glass fiber may be coated or bundled with a thermoplastic resin such as an ethylene / vinyl acetate copolymer or a thermosetting resin such as an epoxy resin.

  The blending amount of the filler is usually 5 to 500 parts by weight, preferably 20 to 400 parts by weight with respect to 100 parts by weight of the liquid crystalline polyester.

  A thermoplastic resin can be blended with the liquid crystalline resin composition of the present invention as long as the characteristics of the present invention are not impaired. The thermoplastic resin is not particularly limited as long as it is a resin that exhibits thermoplasticity. For example, a styrene polymer such as PS (polystyrene), a rubber-reinforced styrene polymer such as HIPS (high impact polystyrene), AS (acrylonitrile), and the like. / Styrene copolymer), AES (acrylonitrile / ethylene / propylene / nonconjugated diene rubber / styrene copolymer), ABS (acrylonitrile / butadiene / styrene copolymer), MBS (methyl methacrylate / Rubber reinforced (co) polymers such as butadiene / styrene copolymers), and in particular, styrene polymers such as PS (polystyrene), styrene copolymers such as AS (acrylonitrile / styrene copolymer). Polymer, ABS (acrylonitrile / butadiene / styrene copolymer), etc. Fats such as len resin, ethylene-vinyl acetate copolymer, fluororesin, polyoxymethylene, nylon 6, nylon 4,6, nylon 6,6, nylon 6,10, nylon 6,12, nylon 11, nylon 12, etc. Polyamide, poly (meta-xylene adipamide), poly (hexamethylene terephthalamide), poly (hexamethylene isophthalamide), poly (tetramethylene isophthalamide), polynonanemethylene terephthalamide, poly (methylpentamethylene terephthalamide) Aliphatic-aromatic polyamide such as nylon 6 / poly (hexamethylene terephthalamide), nylon 66 / poly (hexamethylene terephthalamide), poly (hexamethylene isophthalamide) / Poly (F Samethylene terephthalamide), nylon 6 / poly (hexamethylene isophthalamide) / poly (hexamethylene terephthalamide), nylon 12 / poly (hexamethylene terephthalamide), poly (methylpentamethylene terephthalamide) / poly (hexamethylene) Terephthalamide, polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate, polyethylene-2,6-naphthalate, polybutylene naphthalate, poly-1,4-cyclohexylenedimethylene terephthalate and polyethylene-1,2-bis (phenoxy) ethane-4 , 4'-dicarboxylate, polyethylene isophthalate / terephthalate, polybutylene terephthalate / isophthalate, polybutylene terephthalate / Copolymerized polyesters such as decanedicarboxylate and polycyclohexanedimethylene terephthalate / isophthalate, olefin polymers such as polyimide, polyamideimide, acrylic, vinyl chloride, polypropylene, polyethylene, novel polyolefins (linear low density polyethylene, ultra low Density polyethylene, cyclic olefin resin or copolymer, isotactic polypropylene, syndiotactic polypropylene, syndiotactic polystyrene, ethylene / carbon monoxide copolymer), ethylene / propylene copolymer, ethylene / 1-butene copolymer Polymer, ethylene / propylene / non-conjugated diene copolymer, ethylene / ethyl acrylate copolymer, ethylene / glycidyl methacrylate copolymer, ethylene / vinyl acetate / meta Glycidyl acrylate copolymer and ethylene / propylene-g-maleic anhydride copolymer, olefin copolymer such as ABS, polyester polyether elastomer, polyester polyester elastomer, thermoplastic polyurethane elastomer, thermoplastic styrene butadiene elastomer, heat One or a mixture of two or more selected from elastomers such as plastic olefin elastomers and thermoplastic polyamide elastomers, polyacrylates, polyphenylene ethers, polycarbonates, thermoplastic polyurethanes, polyether sulfones, polyether imides, polyether ketones, polyether ethers Ketones, polyarylene sulfides such as polyphenylene sulfide, cellulose acetate cellulose acetate butyrate, Cellulose derivatives Le cellulose, liquid resin or the like, and melt-moldable resin such as those modified material or one or more of the blend (including alloy material) and the like.

  Among these resins, those classified as engineering plastics and super engineering plastics are preferable. Specifically, nylon, polyalkylene terephthalate, polyphenylene ether, polycarbonate, thermoplastic polyurethane, polyethersulfone, polyetherimide, polyether Polyarylene sulfides such as ketones, polyether ether ketones, and polyphenylene sulfides are preferable, and polyphenylene ethers, polyphenylene sulfides, polyether sulfones, polyether imides, and the like are particularly preferable, and polyether imides are most preferable. When blending a thermoplastic resin such as polyetherimide, it is preferable to blend 1 to 30 parts by weight with respect to 100 parts by weight of the liquid crystalline polyester.

When these preferable thermoplastic resins are blended, the dispersibility of the fine particles can be made more uniform, or the fine particles can be arranged at the interface depending on the kind of the thermoplastic resin.

The liquid crystalline resin composition of the present invention includes an antioxidant and a heat stabilizer (for example, hindered phenol, hydroquinone, phosphites and substituted products thereof), an ultraviolet absorber (for example, resorcinol, salicylate), phosphorous acid. Colorants including salts, anti-coloring agents such as hypophosphite, lubricants and mold release agents (such as montanic acid and its metal salts, its esters, their half esters, stearyl alcohol, stearamide and polyethylene wax), dyes and pigments Carbon black, crystal nucleating agent, plasticizer, flame retardant (bromine flame retardant, phosphorus flame retardant, red phosphorus, silicone flame retardant, etc.), flame retardant aid, antistatic agent, etc. The conventional additive and a polymer other than the thermoplastic resin can be blended to further impart predetermined characteristics.

  Silicone resin, silicone oligomer, and silane coupling agent can be added as a fine particle dispersion aid. Of these, addition of a silicone resin and a silicone oligomer is effective, and the structure is not particularly limited, but 2-branch and 3-branch copolymers are preferable, and 3-branch is more preferable. . Of the alkyl group, alkoxy group, allyl group, etc., the substituent is preferably a methyl group, a methoxy group or a phenyl group. Among them, a methyl group and a phenyl group are preferred, and the ratio thereof is a phenyl group content of 30% or more. More preferably, it is 50% or more, More preferably, it is 70% or more.

  The addition of a tri-branched methylphenyl silicone resin oligomer as a dispersion aid is preferred because the dispersion of fine particles is stable even during a stay exceeding 20 minutes.

  Although it does not specifically limit as addition amount of a dispersing aid, 0.01-3 weight part is preferable with respect to 100 weight part of liquid crystalline polyester, More preferably, it is 0.1-0.5 weight part. is there.

  The production method of the composition of the present invention is preferably by melt kneading, and known methods can be used for melt kneading. For example, using a Banbury mixer, a rubber roll machine, a kneader, a single-screw or twin-screw extruder, etc., it can be melt kneaded at a temperature not lower than the liquid crystal starting temperature of the liquid crystalline polyester and not higher than the melting point to obtain a liquid crystalline resin composition. Among these, a twin screw extruder is preferable.

  Liquid crystalline polyester has the property of flowing when a physical shearing force is applied in the temperature range from the liquid crystal starting temperature to the melting point and below, and in the present invention, this property can be used to knead at a very high pressure. It has been found that, when kneading is performed under such a high pressure state, it is possible to monodisperse fine particles that normally agglomerate and do not monodisperse.

  Here, the liquid crystal start temperature is a temperature at which flow starts under the condition of a shear rate of 1000 (1 / second). For example, the shear rate is 1,000 (1 / second) by a shear stress heating device (CSS-450), It is determined by measuring the temperature at a heating rate of 5.0 ° C./min at an objective lens of 60 times and measuring the temperature at which the entire field of view starts to flow.

  Since the liquid crystal starting temperature changes by about ± 5 ° C. depending on the applied shear rate, the appropriate temperature changes depending on the extrusion conditions, but is preferably the liquid crystal starting temperature of −5 ° C. to the melting point or lower, more preferably the liquid crystal starting temperature. The temperature is −2 ° C. to the liquid crystal starting temperature + 5 ° C., and more preferably the liquid crystal starting temperature is ± 2 ° C.

  As the configuration of the twin screw extruder, a meshing type and a twin screw co-rotating screw are preferable, and the screw length / diameter ratio (L / D) is preferably 25 to 60, more preferably 30 to 50, and most preferably. 40-45.

  It has an original feeder or side feeder, preferably liquid crystalline polyester, and fine particles can be added from the original feeder or from the side feeder, but the fine particles were blended in a stable plasticized state of the liquid crystalline resin. Since the dispersion state can be made more uniform, it is preferable to add fine particles from the side feeder, and the side feeder is controlled so that the resin pressure does not become excessively higher than 1 MPa, and at least two knees are provided after the side feeder. The resin pressure of the ding block part and the die head is preferably controlled to 1 MPa or more, more preferably 2 MPa or more.

  The resin pressure referred to here is the pressure received by the resin, and can be measured, for example, by attaching a resin pressure gauge to the extruder part to be measured.

  Resin pressure can be controlled by kneading temperature, screw arrangement and die diameter, screw L / D, feed amount, and the like, and mainly by changing the feed amount.

  In the present invention, the resin pressure is kept high by controlling the feed amount in a range larger than the conventional control range. For example, in a conventional 35 mmφ extruder with a discharge range of 10 to 12 kg / hour, if the feed amount is increased to 18 to 20 kg / hour, the resin pressure can be doubled. However, in the present invention, the shear rate applied to the resin is increased to 500 to 3000 / by increasing the screw rotation speed, which has been impossible in the prior art. It has been found that when s, more preferably 800 to 2000 / s, the liquid crystalline resin composition can increase the resin pressure without causing such an abnormality.

  By keeping the resin pressure high, the free volume of the resin can be increased, and active energy sufficient to solve the primary aggregation of the particles can be given to the field, and the particles can be monodispersed.

  The monodispersion defined in the present invention can be determined, for example, by cutting an arbitrary cross section of the composition and observing with an electron microscope. Of the 100 observed fine particles, the number of fine particles in contact with each other is the number. The number is 4 or less, preferably 2 or less, and more preferably 0. However, the number here refers to two particles that are in contact with each other as two particles, and if three particles are aggregated, it is counted as three particles, and those that appear to be in contact with each other in the depth direction are not counted. And

  Usually, the liquid crystalline polyester is kneaded at a melting point or higher. In this case, since the resin in the system easily flows, the resin pressure is in a region of less than 1 MPa, and the average particle size is 0.5 μmφ having high cohesive force. Monodispersion cannot be achieved with fine particles less than, particularly less than 0.2 μmφ.

  It is preferable to have one or more vents, more preferably two or more vents, the vent location is preferably installed behind the kneading block after the side feeder, More preferably, it is also installed in front of the kneading block in front of the side feeder because the generated gas of the resin can be efficiently removed.

  As the kneading method, 1) batch kneading method with liquid crystalline polyester, fine particles, optional filler and other additives, 2) liquid crystalline polyester composition containing other additives at high concentration in liquid crystalline polyester Product (master pellet), then adding liquid crystalline polyester, fine particles, optional fillers and the remaining additives to the specified concentration (master pellet method), 3) liquid crystalline polyester Any method may be used, such as a split addition method in which a part of other additives is once kneaded and then the remaining fine particles, optional fillers and the remaining additives are added.

  In the liquid crystalline resin composition of the present invention thus obtained, the fine particles are monodispersed, resulting in a new structure due to the interaction between the fine particles and the liquid crystalline resin. Even though it is blended, it is monodispersed, thereby preventing the crystal structure of the conventional liquid crystalline resin from being generated, and the crystallization speed is significantly reduced.

  Due to these two specific effects, the liquid crystalline resin composition of the present invention has an excellent surface appearance (color tone) and mechanical properties, heat resistance, and the like, by a molding method such as normal injection molding, extrusion molding, and press molding. It can be processed into a flame-retardant molded article, sheet, pipe, film, fiber or the like. Especially, since it is excellent in thin-wall rigidity and thin-wall fluidity, it is suitable for electric / electronic component applications that are being used with thin-wall molded products having a portion of 0.2 mm or less obtained by injection molding.

  The liquid crystalline resin composition thus obtained includes, for example, various gears, various cases, sensors, LED lamps, connectors, sockets, resistors, relay cases, switches, coil bobbins, capacitors, variable capacitor cases, optical pickups, and oscillations. Terminals, various terminal boards, transformers, plugs, printed wiring boards, tuners, speakers, microphones, headphones, small motors, magnetic head bases, power modules, housings, semiconductors, liquid crystal display parts, FDD carriages, FDD chassis, HDD parts, Electric and electronic parts such as motor brush holders, parabolic antennas, computer-related parts; VTR parts, TV parts, irons, hair dryers, rice cooker parts, microwave oven parts, acoustic parts, audio lasers Audio equipment parts such as disk (registered trademark) / compact disk, lighting parts, refrigerator parts, air conditioner parts, typewriter parts, word processor parts, home appliances, office computer parts, telephone parts, Facsimile-related parts, copier-related parts, cleaning jigs, oil-less bearings, stern bearings, underwater bearings and other bearings, motor-related parts such as motor parts, lighters, typewriters, microscopes, binoculars, cameras, Optical equipment such as watches, precision machinery-related parts: alternator terminals, alternator connectors, IC regulators, light meter potentiometer bases, various valves such as exhaust gas valves, fuel-related / exhaust / intake system pipes, air intakes No Snorkel, intake manifold, fuel pump, engine coolant joint, carburetor main body, carburetor spacer, exhaust gas sensor, coolant sensor, oil temperature sensor, throttle position sensor, crankshaft position sensor, air flow meter, brake butt wear sensor , Air conditioner thermostat base, air conditioner motor insulator, heating air flow control valve, radiator motor brush holder, water pump impeller, turbine vane, wiper motor related parts, dust distributor, starter switch, starter relay, transmission wire Harness, window washer nozzle, air conditioner panel switch board, fuel related Solenoid valve coil, fuse connector, horn terminal, electrical component insulation plate, step motor rotor, lamp socket, lamp reflector, lamp housing, brake piston, solenoid bobbin, engine oil filter, ignition device case, etc. Can be used. When used as a film, magnetic recording media film, photographic film, capacitor film, electrical insulation film, packaging film, drafting film, ribbon film, and sheet use as automotive interior ceiling, door trim, instrument panel It is useful for pad materials, bumper and side frame cushioning materials, sound absorbing pads such as the back of bonnets, seat materials, pillars, fuel tanks, brake hoses, nozzles for window washer fluid, air conditioner refrigerant tubes and their peripheral components.

  Hereinafter, although an example explains the present invention still in detail, the gist of the present invention is not limited only to the following example.

(Reference Example 1)
In a 5 L reaction vessel equipped with a stirring blade and a distilling tube, 870 g (6.300 mol) of p-hydroxybenzoic acid, 327 g of 4,4′-dihydroxybiphenyl (1.890 mol), 89 g of hydroquinone (0.810 mol) , 292 g (1.755 mol) of terephthalic acid, 157 g (0.945 mol) of isophthalic acid and 1367 g of acetic anhydride (1.03 equivalent of the total of phenolic hydroxyl groups) were added at 145 ° C. with stirring in a nitrogen gas atmosphere. After reacting for 4 hours, the temperature was raised to 320 ° C. over 4 hours. Thereafter, the polymerization temperature was maintained at 320 ° C., the pressure was reduced to 1.0 mmHg (133 Pa) in 1.0 hour, the reaction was continued for 90 minutes, and the polycondensation was completed when the torque reached 12 kg · cm. Next, the inside of the reaction vessel was pressurized to 1.0 kg / cm ² (0.1 MPa), the polymer was discharged to a strand-like material via a die having one circular discharge port having a diameter of 10 mm, and pelletized by a cutter.

  In this liquid crystalline polyester (A-1), the p-oxybenzoate unit was 70 mol% based on the total of the p-oxybenzoate unit, the 4,4′-dioxybiphenyl unit and the 1,4-dioxybenzene unit. , 4′-dioxybiphenyl units are 70 mol% based on the total of 4,4′-dioxybiphenyl units and 1,4-dioxybenzene units, and terephthalate units are based on the total of terephthalate units and isophthalate units. It consists of 65 mol%, Tm (melting point of liquid crystalline polyester) is 314 ° C., liquid crystal starting temperature is 295 ° C., number average molecular weight is 12,000, and Koka type flow tester (orifice 0.5φ × 10 mm) is used. The melt viscosity measured at a temperature of 324 ° C. and a shear rate of 1000 / s was 20 Pa · s.

  The melting point (Tm) is determined by differential calorimetry. After observing the endothermic peak temperature (Tm1) observed when the polymer is measured at room temperature to 20 ° C./minute, the temperature is maintained at Tm1 + 20 ° C. for 5 minutes. Then, after cooling to room temperature under a temperature drop condition of 20 ° C./minute, the endothermic peak temperature (Tm 2) observed when measured again under a temperature rise condition of 20 ° C./minute was used.

  The molecular weight was measured by GPC-LS (gel permeation chromatography-light scattering) method using pentafluorophenol which is a solvent in which liquid crystalline polyester is soluble, and the number average molecular weight was determined.

(Reference Example 2)
In a 5 L reaction vessel equipped with a stirring blade and a distillation tube, 994 g (7.20 mol) of p-hydroxybenzoic acid, 338.7 g (1.80 mol) of 6-hydroxy-2-naphthoic acid, and 965 g of acetic anhydride (1.05 equivalents of total phenolic hydroxyl groups) was added and reacted at 145 ° C. for 2 hours with stirring under a nitrogen gas atmosphere, and then heated to 330 ° C. over 4 hours. Thereafter, the polymerization temperature was maintained at 330 ° C., nitrogen was pressurized to 0.1 MPa, and the mixture was heated and stirred for 20 minutes. Thereafter, the pressure was released, the pressure was reduced to 133 Pa in 1.0 hour, and the reaction was continued for another 120 minutes. When the torque reached 12 kg · cm, the polycondensation was completed. Next, the inside of the reaction vessel was pressurized to 0.1 MPa, the polymer was discharged to a strand through a die having one circular discharge port having a diameter of 10 mm, and pelletized by a cutter.

  This liquid crystalline polyester (A-2) has 80 mol% of p-oxybenzoate units and 20 mol% of 6-oxy-2-naphthalate units, Tm (melting point of liquid crystalline polyester) is 320 ° C., liquid crystal starting temperature. It had a number average molecular weight of 11,100 at 298 ° C., a melt viscosity of 20 Pa · s measured using a Koka flow tester (orifice 0.5φ × 10 mm) at a temperature of 330 ° C. and a shear rate of 1000 / s. .

(Reference Example 3)
In a 5 L reaction vessel equipped with a stirring blade and a distillation pipe, 994 parts by weight of p-hydroxybenzoic acid (7.20 mol), 126 parts by weight of 4,4′-dihydroxybiphenyl (0.67 mol), 112 weights of terephthalic acid Parts (0.67 mol), 216 parts by weight (1.12 mol) of polyethylene terephthalate having an intrinsic viscosity of about 0.6 dl / g and 960 parts by weight of acetic anhydride (1.10 equivalents of total phenolic hydroxyl groups) The mixture was charged and reacted at 145 ° C. for 2 hours with stirring in a nitrogen gas atmosphere, and then heated to 325 ° C. in 4 hours. Thereafter, the polymerization temperature was maintained at 325 ° C., nitrogen was pressurized to 0.1 MPa, and the mixture was heated and stirred for 20 minutes. Thereafter, the pressure was released, the pressure was reduced to 133 Pa in 1.0 hour, and the reaction was continued for another 120 minutes. When the torque reached 12 kg · cm, the polycondensation was completed. Next, the inside of the reaction vessel was pressurized to 0.1 MPa, the polymer was discharged to a strand through a die having one circular discharge port having a diameter of 10 mm, and pelletized by a cutter.

  This liquid crystalline polyester (A-3) has a p-oxybenzoate unit of 74.4 mol%, a 4,4'-dioxybiphenyl unit of 7 mol%, a terephthalate unit of 7 mol% and an ethylenedioxy unit of 11. 6 mol%, Tm (melting point of liquid crystalline polyester) is 314 ° C., liquid crystal starting temperature is 292 ° C., number average molecular weight is 11,100, and Koka type flow tester (orifice 0.5φ × 10 mm) is used. The melt viscosity measured at a temperature of 325 ° C. and a shear rate of 1000 / s was 12 Pa · s.

(Fine particles)
B-1 X24-9163A manufactured by Shin-Etsu Chemical Co., Ltd. (amorphous true spherical silica: average particle size 0.15 μmφ, hydrophobized product)
B-2 Crystallite cut product (0.18μmφ, granular) of crystallite (0.9μmφ crystalline silica) made by Tatsumori
B-3 Kumi Kogyo HTPULTRA 5C (0.5 μmφ talc) crushed granule cut product (0.16 μmφ, plate-like)
B-4 Admatechs SO-C1 (Amorphous true spherical silica: average particle size 0.28 μm, hydrophobized product)
B-5 Sakai Kogyo HTPULTRA 5C (0.5μm talc)

(Additive)
C-1 Shin-Etsu Silicone X40-9805 (2, 3-branch copolymer methylphenyl silicone resin)
D-1 Polyetherimide Ultem 1000 made by GE Plastics Japan

Examples 1-12, Comparative Examples 1-7
A side feeder is installed in C3 part of cylinder C1 (former feeder side heater) to C6 (die side heater) in TEM35B type twin screw extruder (meshing type same direction) manufactured by Toshiba Machine, and a vacuum vent is provided in C5 part. installed.

  Using a screw arrangement in which kneading blocks were incorporated in C2 part and C4 part, 100 parts by weight of the liquid crystalline polyester (A-1 to A-3) obtained in the reference example was introduced from the hopper, and the blending amounts shown in Table 1 were used. Fine particles and other additives and fillers (GF: ECS03T747H manufactured by Nippon Electric Glass Co., Ltd.) are introduced from the side, and the resin temperature of the resin thermometer attached to C4 part and C6 part is liquid crystal polyester liquid crystal starting temperature ± 2 ° C. Adjust the heater set temperature of the cylinder so that the resin pressure is measured with the resin pressure gauge attached to the C4 and C6 parts, and adjust the rotational speed of the feed feeder and side feeder and the screw rotational speed. The mixture was melt-kneaded under the specified finger pressure conditions to form pellets.

  After drying with hot air, the pellets were subjected to a FANUC α30C injection molding machine (manufactured by FANUC CORPORATION), and the following (1) to (3) were evaluated.

(1) Solidification (crystallization) speed The resin temperature is set to 330 ° C., the injection speed is set to 100 mm / s, the injection pressure is set to 30 MPa, the mold temperature is changed from 220 ° C. to 30 ° C., 150 mm length × 3 The rod flow length was measured with a rod flow test piece mold having a width of 2 mm and a thickness of 0.5 mm, and the inflection point temperature (Tc) at which the rod flow length began to become remarkably short was evaluated.

(2) Storage elastic modulus A resin temperature of 330 ° C., a mold temperature of 130 ° C., an injection speed of 120 mm / s, an injection pressure of 80 MPa, a square plate of 100 mm square × 2 mm thickness is formed, and a skin layer from the center of the molded product A core part 50 mm long × 10 mm wide × 1 mm thick with the TD direction peeled off is cut out and stored at 23 ° C. and 100 ° C. in a bending sine wave mode using an EXSTAR6000 DMS viscoelastic spectrometer manufactured by Seiko Instruments Inc. The elastic modulus was measured.

  Moreover, the same evaluation was performed also about what made the residence time in a molding machine into 20 minutes normally 4 minutes.

(3) Dispersibility The arbitrary cross section of the molded product obtained in (1) was cut and observed using a transmission electron microscope (TEM). Ignoring overlap in the depth direction, the following determination was made. A: 0 of 100 fine particles in contact with each other, ○: 2 or less fine particles in contact with each other in 100 fine particles, and Δ: 100 fine particles in contact with each other 4 or less fine particles, x: 5 or more fine particles in contact with each other among 100 fine particles

  As is clear from Table 1, the liquid crystalline resin composition of the present invention does not decrease fluidity even when the mold temperature is lowered, and has a high storage elastic modulus at high temperature. Deformation defects such as deformation are unlikely to occur.

  Moreover, the improvement effect of storage elastic modulus is much higher than the effect by the conventional filler, and it turns out that the effect is maintained also by combined use with a filler.

  The effect of the present invention can be obtained slightly even when aggregation has occurred, but it can be seen that the effect is high when kneaded at high pressure and monodispersed.

  Such an effect of the present invention is not obtained with fine particles having a large particle size, and thus it is understood that this effect is a specific effect obtained with fine particles having a very limited particle size.

Claims (8)

A liquid crystalline resin composition comprising 1 to 5 parts by weight of fine particles having an average particle size of 0.08 μm or more and less than 0.2 μm in 100 parts by weight of liquid crystalline polyester. The liquid crystalline resin composition according to claim 1, wherein the fine particles are silica fine particles. 3. The liquid crystalline resin composition according to claim 2, wherein the silica fine particles are made of amorphous silica. 4. The liquid crystalline resin composition according to claim 2, wherein the silica fine particles are spherical silica. The liquid crystalline resin composition according to claim 1, wherein the fine particles are monodispersed. The liquid crystalline polyester is composed of the structural units (I) to (V), the structural unit (I) is 65 to 80 mol% with respect to the total of the structural units (I), (II) and (III), and the structure The unit (II) is 60 to 75 mol% based on the total of the structural units (II) and (III), and the structural unit (IV) is 60 to 92 based on the total of the structural units (IV) and (V). 6. The liquid crystal according to claim 1, wherein the total number of structural units (II) and (III) and the total of (IV) and (V) are substantially equimolar. Resin composition.

A liquid crystalline resin composition obtained by further blending 5 to 200 parts by weight of a filler with the liquid crystalline resin composition according to claim 1. The method for producing a liquid crystalline resin composition according to any one of claims 1 to 7, wherein when the liquid crystalline resin and the silica fine particles are kneaded, the resin pressure is 1 MPa or more.