JP2007217566A - High specific gravity composite material composition and its molded article - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a composite material composition which can form high specific gravity molded articles having extremely good appearances and excellent in mechanical strengths, rigidity, surface hardness, dimensional stability, hydrolysis resistance, chemical resistance and magnetic characteristics. <P>SOLUTION: This composite material composition comprises (A) 100 pts.wt. of polytrimethylene terephthalate resin having an intrinsic viscosity [η] of 0.6 to 2.0 dl/g, (B) 100 to 9,900 pts.wt. of a metal material, and (C) 0 to 50 pts.wt. of a crystal-nucleating agent. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a thermoplastic resin advanced composite material composition capable of forming a high specific gravity molded body excellent in appearance, and a high specific gravity molded body formed by molding the composite material composition.

  Thermoplastic resin moldings are excellent in moldability, appearance, lightness, mechanical properties, recyclability, etc., and are therefore used in many industrial parts, electrical / electronic parts, automobile parts, housing parts, and the like. However, there are cases where rigidity, surface hardness, etc. are inferior compared to metal materials and ceramic materials, and many materials and molded bodies in which thermoplastic resin materials are filled with inorganic materials to reinforce them are proposed and manufactured. It has been. In general, thermoplastic resins are non-magnetic materials and insulators. Therefore, by adding magnetic materials and conductive materials as inorganic fillers to impart magnetic properties and conductivity, the original moldability of thermoplastic materials can be utilized. On the other hand, many proposals have been made on composite materials having functions that were difficult to obtain with a single thermoplastic resin.

  On the other hand, lead with high specific gravity and high economic efficiency has been widely used for weights, etc. as high specific gravity parts, but there is a high risk of contaminating soil and water quality after disposal, which is a big social problem in terms of environmental harmony .

  Therefore, many proposals have been made for high specific gravity materials that do not use lead, and among them, proposals have been made for materials that are excellent in formability and environmental friendliness by combining tungsten, which has a higher specific gravity than lead, with plastic. Specific examples of materials filled with plastic include polytetramethylene terephthalate (also known as polybutylene terephthalate resin) and metals such as copper, brass, stainless steel, iron alloys, nickel, nickel alloys, tin, aluminum, gold, and platinum. A composite material with powder has been proposed (Patent Document 1).

  Moreover, regarding the composite material of a high specific gravity metal and resin, the proposal of the composite material of nylon resin and tungsten (patent document 2), tungsten, a saturated aliphatic carboxylic acid compound, a thermoplastic resin composition (patent document 3) In addition, proposals have been made on an inorganic powder having a specific gravity of 10 or less, a thermoplastic resin filled with an inorganic powder having a specific gravity of 10 or more (Patent Document 4), and the like.

  However, when the inorganic material is filled, if the content of the inorganic filler is increased, kneading becomes difficult. Especially when compounded using a highly productive extruder, the problem that the strand does not break well often occurs. It was.

  Moreover, even if a composite material composition is made, in an injection molded product using the composite material composition, there is often a problem that the filling material is exposed to the surface of the thermoplastic resin molded body and the appearance is deteriorated. Further, when the exposed inorganic material is a metal material, there has been a problem that the characteristics and appearance of the composite material are impaired by corrosion.

  Therefore, when these composite materials are used for external parts, troublesome problems such as painting to compensate for poor external appearance, covering the surface with a thermoplastic resin, and covering the molded product with a cover arise. It was.

JP-A-56-159248 JP-A-10-229785 JP-A-3-215563 JP 2001-164039 A

  An object of the present invention is to provide a composite material composition that can form a high specific gravity molded article having an extremely good appearance and excellent mechanical strength, rigidity, surface hardness, dimensional stability, hydrolysis resistance, and chemical resistance. And a composite material molded body obtained by molding the composite material composition.

  The present inventor has found a molded product that solves the problems in the previous term and has reached the present invention.

  That is, the composite material composition of the present invention comprises (A) 100 parts by weight of a polytrimethylene terephthalate resin having an intrinsic viscosity [η] of 0.6 dl / g or more and 2.0 dl / g or less; -9900 parts by weight and (C) 0-15 parts by weight of a crystal nucleating agent.

  In the composite material composition of the present invention, it is preferable that at least one of the (B) metal material is a high specific gravity material having a specific gravity of 10 or more.

  Moreover, the composite material molded body of the present invention is formed by molding the composite material composition described above.

  In the composite material molded body of the present invention, it is preferable that 95% or more of the surface of the composite material molded body is covered with a resin.

  The composite composition of the present invention has a good appearance with little exposure of metal materials to the surface, mechanical strength, rigidity, surface hardness, dimensional stability, hydrolysis resistance, chemical resistance, corrosion resistance, conductivity It is possible to form a high specific gravity molded body having excellent weight and feeling of weight.

  Therefore, the composite material molded body of the present invention can be used, for example, for entertainment / fishing parts such as fishing weights, electrical / electronic parts such as acoustic-related members, automobile parts such as tire balancers, industrial parts, clay shooting, etc. Used for a wide range of purposes, such as bullets for use.

  The present invention will be specifically described below.

<(A) Polytrimethylene terephthalate resin>
The (A) polytrimethylene terephthalate resin (hereinafter sometimes abbreviated as “PTT resin”) of the present invention refers to a polyester polymer using terephthalic acid as the acid component and trimethylene glycol as the glycol component. ing.

  Here, the trimethylene glycol is selected from 1,3-propanediol, 1,2-propanediol, 1,1-propanediol, 2,2-propanediol, or a mixture thereof. From this viewpoint, 1,3-propanediol is particularly preferable.

  In addition, as long as the object of the present invention is not impaired, an aromatic dicarboxylic acid other than terephthalic acid, for example, phthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, diphenyldicarboxylic acid, diphenyletherdicarboxylic acid, Diphenoxyethane dicarboxylic acid, diphenylmethane dicarboxylic acid, diphenyl ketone dicarboxylic acid, diphenyl sulfone dicarboxylic acid, etc .; aliphatic dicarboxylic acids such as succinic acid, adipic acid, and sebacic acid; alicyclic dicarboxylic acids such as cyclohexane dicarboxylic acid; ε-oxy Using oxydicarboxylic acid such as caproic acid, hydroxybenzoic acid, hydroxyethoxybenzoic acid, etc., as glycol components, ethylene glycol, tetramethylene glycol, pentamethylene glycol, hexamethylene glycol, Kuta glycol, neopentyl glycol, cyclohexanedimethanol, xylylene glycol, diethylene glycol, polyoxyalkylene glycol, may be copolymerized with some hydroquinone.

  The amount of the copolymer component in the copolymerization is not particularly limited as long as it does not impair the object of the present invention, but is usually 20 mol% or less of the total acid component or 20 mol% or less of the total glycol component. It is desirable to be.

  In addition, the polyester component described above may be branched components such as tricarbaric acid, trimesic acid, trimellitic acid and other trifunctional or tetrafunctional group-forming acids, or glycerin, trimethylolpropane, pentaerythritol and the like. Alcohols having a functional or tetrafunctional ester-forming ability may be copolymerized, and in this case, the amount of these branching components is 1.0 mol% or less of the total acid component or the total glycol component, preferably 0.8. 5 mol% or less, more preferably 0.3 mol% or less.

  Further, PTT may be used in combination of two or more of these copolymer components.

  The method for producing the PTT used in the present invention is not particularly limited. For example, it is described in JP-A-51-140992, JP-A-5-262862, JP-A-8-311177, and the like. Can be obtained according to the method.

  For example, terephthalic acid or an ester-forming derivative thereof (for example, a lower alkyl ester such as dimethyl ester or monomethyl ester) is reacted with trimethylene glycol or an ester-forming derivative thereof at a suitable temperature and time in the presence of a catalyst. Further, there is a method in which the glycol ester of terephthalic acid obtained is subjected to a polycondensation reaction to a desired degree of polymerization at a suitable temperature and time in the presence of a catalyst.

  The polymerization method is not particularly limited, and melt polymerization, interfacial polymerization, solution polymerization, bulk polymerization, solid phase polymerization, and a combination of these can be used.

  The intrinsic viscosity [η] of the polytrimethylene terephthalate resin of the present invention is preferably 0.60 dl / g or more from the viewpoint of mechanical properties, particularly toughness, and [η] is 0.68 dl / g or more. In view of moldability, particularly burr characteristics, [η] is most preferably 0.75 dl / g or more. [Η] is preferably 2.0 dl / g or less, more preferably 1.6 dl / g or less, in order to obtain a molded article having an excellent appearance in terms of fluidity and moldability.

The intrinsic viscosity [η] of the PTT resin described above was determined based on the following defining formula.
[Η] = lim (1 / C) × (ηr−1) C → 0

  The definition formula ηr is a value obtained by dividing the viscosity of a diluted polytrimethylene terephthalate solution dissolved in o-chlorophenol having a purity of 98% or more at 35 ° C. by the viscosity of the solvent itself measured at the same temperature. Is defined. C is the solute weight value in grams in 100 ml of the solution.

<(B) Metal material>
Next, the metal material of the present invention will be described.

  The metal material in the present invention is a material that is generally filled into a resin for the purpose of strengthening physical properties such as rigidity and strength, improving surface hardness, conductivity, high specific gravity characteristics, and the like. There is no limitation, but there are powder, fiber, flake, plate, bead and the like.

  Particularly preferred metal materials include high specific gravity materials having a specific gravity of 10 or more. Specific examples of high specific gravity metal materials include palladium, platinum, gold, silver, lead, mercury, cadmium, etc., but from the viewpoint of economy and safety, especially environmental harmony with little environmental pollution. Tungsten is preferred. The shape of tungsten is preferably in the form of powder in view of appearance and performance of the molded body, and the average particle size is 1 to 50 μm, preferably 3 to 20 μm, and most preferably 5 to 15 μm.

  The addition amount of the metal material in the present invention is 100 to 9900 parts by weight with respect to 100 parts by weight of the PTT resin, and it is possible to provide a composite material and a composite molded body that have never existed at such a high concentration. it can. In particular, the characteristics of the present invention can be utilized more effectively in a high filling region of 1000 parts by weight or more of a metal material, or even 5000 parts by weight or more.

  That is, it has been difficult to easily obtain a high-quality, high-concentration metal-filled material composition by combining conventional thermoplastic resins and metal materials. For example, when trying to create a composite material composition using a PBT resin, which is a polyester resin similar to a PTT resin, as a thermoplastic resin, in a high filling region, a strand is good at the time of extrusion molding for pellet production. There were problems that the composite material composition with good dispersibility could not be produced with good mass productivity, such as the problem that it could not be formed, the torque of the extruder increased, and molding was impossible, and the screw wear was severe.

  Surprisingly, however, it has been found that by using PTT resin, it is possible to compound a metal material to a higher concentration filling region into a pellet shape, and at the same time, to create a composite material composition with good dispersibility. Invented. Furthermore, it has been found that a molded article using the composite material composition of the present invention has a good appearance, excellent quality and mechanical properties, and has reached the present invention.

<(C) Crystal nucleating agent>
In the present invention, (C) a crystal nucleating agent may be added in order to control the crystallization rate of the PTT resin.

  That is, the composite material composition of the present invention has a crystallization temperature of 170 to 190 ° C. when the temperature is lowered from the molten state using DSC, from the viewpoint of suppressing the productivity and heat shrinkage rate of the molded body. Preferably, it is 175-185 degreeC. The crystallization temperature was increased from room temperature to 270 ° C. at a set temperature increase rate of 20 ° C./minute using DSC, held at 270 ° C. for 3 minutes, and then lowered to 0 ° C. at 20 ° C./minute. Can be obtained as an index.

  Such crystallization of the PTT resin can be achieved by appropriately adjusting the conditions at the time of producing the molded article, but can be more easily achieved by including a crystal nucleating agent in the composition. Become. The content of the crystal nucleating agent is 0 to 50 parts by weight with respect to 100 parts by weight of the PTT resin, and the preferable amount is determined depending on the type of the crystal nucleating agent.

  The (C) crystal nucleating agent used in the present invention is not particularly limited as long as it is a compound that can control the crystallization rate of the PTT resin, and specific examples include talc and alkali metal inorganic salts. Specific examples of the alkali metal inorganic salt include sodium montanate, sodium stearate, sodium carbonate, sodium bicarbonate, monosodium hydrogen phosphate, trisodium phosphate, and sodium dihydrogen phosphate. As these content, it is preferable that it is 0.001-1 weight part with respect to 100 weight part of PTT resin, and it is more preferable that it is 0.1-0.6 weight part.

  As other crystal nucleating agents, ionomer resins are also preferable. The ionomer resin is obtained by neutralizing a copolymer mainly composed of an α-olefin and an α, β-unsaturated carboxylic acid having 3 to 8 carbon atoms with 1 to 3 metal ions. Specific examples of the α-olefin include ethylene, propylene, butene-1, etc. Among them, ethylene is particularly preferable. Specific examples of the α, β-unsaturated carboxylic acid having 3 to 8 carbon atoms include acrylic acid, methacrylic acid, ethacrylic acid, itaconic acid, maleic acid and the like. Among these, acrylic acid, methacrylic acid, etc. An acid is used. As content of ionomer resin, it is preferable that it is 0.1-18 weight part with respect to 100 weight part of PTT resin, and it is more preferable that it is 0.3-6 weight part.

  In addition, polyesters other than PTT, such as polyethylene terephthalate and polybutylene terephthalate, exhibit effects as crystal nucleating agents. As these content, it is preferable that it is 1-43 weight part with respect to 100 weight part of PTT resin, It is more preferable that it is 2-34 weight part, It is still more preferable that it is 5-25 weight part.

  Furthermore, a styrene copolymer containing an epoxy group having an epoxy value of 0.1 to 10 meq / g is also preferable as a crystal nucleating agent. Here, the styrene copolymer is obtained by copolymerizing a vinyl monomer having an epoxy group and styrene. Examples of the vinyl monomer having an epoxy group include glycidyl (meth) acrylate, (meth) acrylic acid ester having a cyclohexene oxide structure, (meth) allyl glycidyl ether, and the like, preferably glycidyl (meth) acrylate. is there. As these content, it is preferable that it is 0.01-15 weight part with respect to 100 weight part of PTT resin, It is more preferable that it is 0.1-5 weight part, 0.3-3 weight part More preferably it is.

  In addition, the (B) metal material used in the present invention can be used as a crystal nucleating agent, and if a desired effect can be obtained, it is not necessary to use a crystal nucleating agent in addition to the metal material. In this case, the content of (B) metal material is selected within the range of 100 to 9900 parts by weight of (C) metal material with respect to 100 parts by weight of (A) PTT resin required as the metal material, C) The content as a crystal nucleating agent is not limited to 0 to 50 parts by weight.

<Other ingredients>
In the present invention, a thermoplastic resin other than (A) PTT resin may be used. Specific examples of the thermoplastic resin include, for example, polycarbonate resin, polyamide resin, polyphenylene sulfide resin, polyoxymethylene resin, polyphenylene ether resin, ethylene / propylene / non-conjugated diene resin, ethylene / ethyl acrylate resin, ethylene / glycidyl methacrylate. Resin, ethylene / vinyl acetate / glycidyl methacrylate resin, ethylene / vinyl acetate / glycidyl methacrylate resin, ethylene / propylene-g-maleic anhydride resin, styrenic resin, or a mixture of two or more of these thermoplastic resins. .

  Among these, polycarbonate resin is most preferable from the viewpoint of mechanical properties.

  The polycarbonate resin is produced from a dihydric phenol and a carbonate precursor by a melting method or a solution method. That is, a known acid acceptor in a solvent such as methylene chloride, a reaction between a dihydric phenol and a carbonate precursor such as phosgene in the presence of a molecular weight modifier, or a carbonate precursor such as dihydric phenol and diphenyl carbonate. It can be produced by transesterification with

  Preferred dihydric phenols here include bisphenols, and 2,2-bis (4-hydroxyphenyl) propane, that is, bisphenol A is particularly preferred. Moreover, what substituted a part or all of phenol A with the bihydric phenol may be used. Examples of dihydric phenols other than bisphenol A include hydroquinone, 4,4-dihydroxydiphenyl, bis (4-hydroxyphenyl) alkane, bis (4-hydroxyphenyl) cycloalkane, bis (4-hydroxyphenyl) sulfide, bis ( Examples include compounds such as 4-hydroxyphenyl) sulfone, bis (4-hydroxyphenyl) sulfoxide, and bis (4-hydroxyphenyl) ether. These dihydric phenols may be a dihydric phenol homopolymer or two or more types of copolymers.

  Examples of the carbonate precursor include carbonyl halides and carbonyl esters, and phosgene, diphenyl carbonate, and mixtures thereof are preferably used. In addition, the weight average molecular weight (MW) of the polycarbonate resin used in the present invention is preferably in the range of 5000 to 200000, more preferably 15000 to 40000.

  There is no restriction | limiting in particular as a polyamide resin, A well-known polyamide resin or those 2 or more types of mixtures can be used. Particularly suitable polyamide resins include polycaprolactam (nylon 6), polyhexamethylene adipamide (nylon 6,6), polyhexamethylene dodecamide (nylon 612), polyhexamethylene isophthalamide (nylon 6I) or these Of these, a polyamide copolymer containing at least two different polyamides.

  Examples of the styrene resin include polystyrene resin, rubber-modified polystyrene resin, AS resin, ABS resin, or a mixture thereof.

  It is preferable that the compounding quantity of a thermoplastic resin does not exceed the compounding quantity of (A) polytrimethylene terephthalate resin from a viewpoint of an external appearance and surface hardness. More preferably, it is 0-100 weight part with respect to 100 weight part of PTT resin, and it is still more preferable that it is 0-50 weight part.

  In the present invention, a thermosetting resin may be further filled as necessary. Specifically, an epoxy resin etc. are mentioned.

  Here, the epoxy resin refers to a thermosetting compound having two or more epoxy resins (oxirane rings) in the molecule. Specifically, the so-called bisphenol A type epoxy resin, bisphenol S type epoxy resin, bisphenol F type epoxy resin, resorcin type epoxy resin, phenol novolac and linear high molecular weight cresol produced by the condensation polymerization reaction of bisphenol A and epichlorohydrin. Examples thereof include novolak-type epoxy resins, aliphatic epoxy resins, alicyclic epoxy resins, polyglycidylamine-type epoxies, which are polyfunctional epoxies obtained by glycidylation of novolak.

  As an epoxy resin used in the present invention, a novolak type epoxy resin having an epoxy equivalent of 150 to 280 (/ eq.) Or a bisphenol A having an epoxy equivalent of 600 to 3000 (/ eq.) From the viewpoint of chemical resistance and dispersion in the resin. A type epoxy resin is preferably used. More preferably, it is a novolak type epoxy resin having an epoxy equivalent of 180 to 250 (/ eq.) And a molecular weight of 1000 to 6000, or a bisphenol A type epoxy resin having an epoxy equivalent of 600 to 3000 (/ eq.) And a molecular weight of 1200 to 6000. If the epoxy equivalent and molecular weight are too small, sufficient chemical resistance cannot be obtained, and if it is too large, sufficient dispersibility in the resin cannot be obtained and a uniform composition is difficult to obtain.

  The blending amount of the thermosetting resin is preferably 0.1 to 25 parts by weight with respect to 100 parts by weight of the PTT resin, from the viewpoints of mechanical properties, surface hardness, chemical resistance, and prevention of fluidity reduction. More preferably, it is 3 to 10 parts by weight.

  Further, in the present invention, metal powder having a specific gravity of 10 or less, and alloys thereof, alumina, magnesia, silica, metal oxides such as iron oxide, zinc oxide and barium oxide, carbides such as silicon carbide and boron carbide, aluminum boride Borides such as molybdenum boride, nitrides such as boron nitride, silicon nitride, and aluminum nitride, and sulfides such as molybdenum sulfide may be added as necessary. Further, sulfates such as barium sulfate and calcium sulfate, sulfates such as calcium carbonate, carbonates such as calcium carbonate and magnesium carbonate, carbon such as graphite, carbon black and pitch may be used in combination.

  In this invention, you may mix an inorganic filler as needed.

  Examples of fibrous inorganic fillers include carbon fibers, silica fibers, silica / alumina fibers, zirconia fibers, boron nitride fibers, silicon nitride fibers, boron fibers, potassium titanate whiskers, calcium carbonate whiskers, wollastonite, Furthermore, inorganic fibrous substances, such as stainless steel, aluminum, titanium, copper, and brass, are mentioned.

  The average fiber length (L), average fiber diameter (D), and aspect ratio (L / D) of the fibrous inorganic filler are not particularly limited, but from the viewpoint of mechanical properties, the average fiber length is 50 μm or more, and the average fiber The diameter is preferably 5 μm or more, and the aspect ratio is preferably 10 or more. Carbon fibers having an average fiber length of 100 to 750 μm, a number average fiber diameter of 3 to 30 μm, and an aspect ratio of 10 to 100 are preferably used. Further, wollastonite having an average fiber diameter of 3 to 30 μm, an average fiber length of 10 to 500 μm, and an aspect ratio of 3 to 100 is preferably used.

  Examples of granular inorganic fillers include carbon black, silica, quartz powder, calcium borate, aluminum silicate, carillon, clay, silicates such as diatomaceous earth, oxides of metals such as iron oxide, titanium oxide, zinc oxide, and alumina, carbonic acid Examples thereof include metal carbonates such as calcium and magnesium carbonate, metal sulfates such as calcium sulfate and barium sulfate, silicon carbide, silicon nitride, boron nitride, and various metal powders.

  Examples of the plate-like inorganic filler include mica and various metal foils. Mica, kaolin, calcium carbonate, and potassium titanate preferably have an average particle size of 0.1 to 100 μm.

  In the composite material composition of the present invention, other components can be appropriately blended according to various uses and purposes. Formability improvers include phosphate esters, phosphites, higher fatty acids, higher fatty acid metal salts, higher fatty acid esters, higher fatty acid amide compounds, polyalkylene glycols or terminal modified products thereof, low molecular weight Examples include polyethylene or oxidized low molecular weight polyethylenes, substituted benzylidene saw beets, polysiloxanes, and caprolactones.

  In addition, the composite material composition of the present invention includes generally used flame retardants, ultraviolet absorbers, heat stabilizers, antioxidants, plasticizers, colorants, and color-adjusting materials as long as the object of the present invention is not impaired. In addition, additives such as an antistatic agent, a fluorescent whitening material, a matting material, and an impact strength improving agent can be blended.

<Production method>
The compounding method of (A) polytrimethylene terephthalate resin and (B) metal material, and (C) crystal nucleating agent added as necessary is not particularly limited, but generally used roll, kneader, Banbury mixer, short axis extrusion It can be carried out using a machine, a twin screw extruder or the like. When kneading with an extruder, it may be pre-blended using a Henschel mixer or the like in advance. In this case, the PTT resin may be in the form of pellets, but a powder is preferable for achieving a uniform blend. In order to perform uniform kneading with high productivity, a twin screw extruder is suitable. When using a twin screw extruder, each material may be mixed in advance with a Henschel mixer or the like, or a metal material may be charged from a side feeder of the extruder. In this case, the PTT resin may be either a powder or a pellet.

<Composite material compact>
The composite material molded body according to the present invention is formed by molding the composite material composition of the present invention, and is preferably a molded body with a good appearance in which the surface of the molded body is substantially covered with a resin, more preferably, A molded body in which 95% or more of the surface of the molded body is covered with a resin. As described above, since the exposure of the metal material to the surface of the molded body is small, the appearance is excellent, and at the same time, the risk of corrosion and deterioration due to contact of the metal with the atmosphere due to the exposure can be reduced.

  The molding method is not particularly limited as long as it is a normal thermoplastic resin molding method, but an injection molding method is preferred to obtain a molded article having a good appearance. Furthermore, the injection molding conditions such as the resin temperature, injection pressure, injection speed, and mold temperature are important for determining the surface state of the molded body, and among them, the mold temperature should be controlled in the range of 90 ° C to 110 ° C. Is the most important.

<Example 1>
(A) 100 parts by weight of PTT resin (intrinsic viscosity [η] 1.0 dl / g) powder, and (B) tungsten powder as a metal material (specific gravity 19.3, average particle size of about 3.5 μm, purity 99. 9%) 300 parts by weight were pre-blended using a Henschel mixer and kneaded using a twin-screw extruder to prepare pellets. The compound was able to form continuous strands and could be pelletized.

  A flat plate was prepared by injection molding using the obtained pellets. Injection molding was performed under molding conditions of a mold temperature of 100 ° C. and a cylinder temperature of 275 ° C.

  The obtained molded body was a high specific gravity molded body having a specific gravity of 4 and excellent in appearance with little exposure to the surface of the tungsten powder.

<Example 2>
100 parts by weight of PTT resin powder used in Example 1, 3000 parts by weight of tungsten powder used in Example 1, 5 parts of orthocresol novolac type epoxy resin (AER ECN1299, manufactured by Asahi Kasei Epoxy), polycarbonate resin (MFR10 (300 10 parts in advance using a Henschel mixer, and this is supplied to the hopper of a twin-screw extruder, so that the ratio is 50 parts by weight of wollastonite (NIGLOSS 8 manufactured by NICO). The pellets were prepared by kneading from the side feeder. The compound was able to form continuous strands and could be pelletized.

  A flat plate was prepared in the same manner as in Example 1 using the obtained pellet.

  The obtained molded body was a high specific gravity molded body with a specific gravity of 13 having a surface hardness of 3H with little exposure to the surface of the tungsten powder and excellent appearance.

<Comparative Example 1>
(A) Pellets were made in the same manner as in Example 1 except that polybutylene terephthalate (manufactured by Polyplastics Co., Ltd., Juranex 2002) was used instead of the PTT resin. The composition could not be made.

<Comparative example 2>
(A) An attempt was made to produce pellets in the same manner as in Example 2 except that the polybutylene terephthalate used in Comparative Example 1 was used instead of the PTT resin, but the magnetic powder and the resin separated at the exit of the extruder die. As a result, it was difficult to compound and a composite material composition could not be prepared.

Claims (4)

  (A) 100 parts by weight of polytrimethylene terephthalate resin having an intrinsic viscosity [η] of 0.6 dl / g to 2.0 dl / g, (B) 100 to 9900 parts by weight of a metal material, and (C) crystals A composite material composition comprising 0 to 50 parts by weight of a nucleating agent.   The composite material composition according to claim 1, wherein at least one of the (B) metal material is a high specific gravity material having a specific gravity of 10 or more.   A composite material molded body obtained by molding the composite material composition according to claim 1.   The composite material molded body according to claim 3, wherein 95% or more of the surface of the composite material molded body is covered with a resin.