JP2006219626A - Polybutylene terephthalate resin composition and molded article made thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polybutylene terephthalate resin composition having low specific gravity, excellent emboss pattern transferability, small shrinkage, and excellent mechanical strength and high-temperature moldability and provide a molded article having precisely transferred emboss pattern and produced by molding the composition. <P>SOLUTION: The polybutylene terephthalate resin composition is produced by compounding (A) 25-90 wt.% polybutylene terephthalate resin, (B) 25-1 wt.% polyester resin except for polybutylene terephthalate and having a crystallization temperature of 140-210°C, (C) 35-3 wt.% rubber-modified polystyrene resin and (D) 15-1 wt.% one or more polymers selected from aromatic polycarbonate resin and polystyrene-maleic anhydride copolymer (the sum of A to D is 100 wt.%). The invention further provides a molded article produced by molding the resin composition. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

The present invention relates to a low specific gravity polybutylene terephthalate resin composition that provides a molded product excellent in texture transferability, small shrinkage, and excellent in mechanical strength and high-temperature moldability, and a molded product formed by molding the same. About.

  Polybutylene terephthalate resin (hereinafter sometimes abbreviated as PBT resin) is excellent in ease of processing, mechanical properties, heat resistance, and other physical and chemical properties. It is widely used as a material resin for manufacturing equipment parts and other precision equipment parts.

  From the viewpoint of recent exhaust gas regulations in the automobile field, the demand for weight reduction of molded products has become strict, and at the same time, the demand for economy such as material cost reduction has become strict. Further, in order to be used for automobile interior parts, those having good dimensional accuracy are required, and parts having a textured surface are often seen from the viewpoint of design. Accordingly, there is a demand for a material that meets such demands and has excellent texture transferability, a small shrinkage rate, and a low specific gravity.

  By the way, the specific gravity of PBT is 1.32, and there is a problem that it cannot be said that it is lighter than other resins such as polyamide and polyphenylene oxide. In addition, PBT has a high crystallization speed, so the molding cycle is fast and the manufacturing cost of the parts can be kept low. On the other hand, it is not suitable for molding parts with fine surface characteristics such as warpage of the molded product and wrinkles. There is a place.

  Therefore, the present inventors have made various studies from the viewpoint of weight reduction and low shrinkage, and disclosed Patent Documents 1 and 2. Patent Document 1 discloses a thermoplastic resin composition containing a resin component composed of 95 to 10% by weight of a polybutylene terephthalate resin, 4 to 50% of a rubber-modified polystyrene resin, and 1 to 40% by weight of an aromatic polycarbonate resin. It is shown that it is excellent in reducing molding shrinkage and improving weight reduction.

Patent Document 2 discloses a resin component total amount of 100% by weight comprising 95 to 10% by weight of a polybutylene terephthalate resin, 4 to 50% by weight of a rubber-modified polystyrene resin, and 1 to 40% by weight of a maleic anhydride-modified polystyrene resin. The thermoplastic resin composition characterized by containing 0.1 to 150 parts by weight of the reinforcing filler with respect to the part is excellent in improvement of moldability and impact resistance, warpage, and dimensional accuracy. It is shown.
However, in Patent Documents 1 and 2 described above, the texture transferability of the polycarbonate resin composition is not considered at all, and the texture transferability, shrinkage rate, mechanical properties of the resin compositions disclosed in these documents are not considered. There was a need to further improve the strength.

JP 2002-127552 A JP 2004-10856 A

  The object of the present invention is to provide a low specific gravity polybutylene terephthalate resin composition excellent in texture transferability, small shrinkage, and excellent in mechanical strength and high temperature moldability, and texture formed by molding it. The object is to provide a transferred molded article.

  The present inventors have conducted extensive studies to solve the above-mentioned problems. As a result, a polybutylene terephthalate resin composition comprising (A) a polybutylene terephthalate resin and (C) a rubber-modified polystyrene resin. In (B), by blending a specific amount of a specific polyester resin other than polybutylene terephthalate, a low specific gravity is particularly excellent in emboss transferability, small in shrinkage, and excellent in mechanical strength and high temperature moldability. The present invention was completed by finding that a resin composition was obtained.

That is, the first gist of the present invention is:
(A) 25-90% by weight of polybutylene terephthalate resin
(B) A polyester resin other than polybutylene terephthalate having a crystallization temperature of 140 to 210 ° C.
(C) 35-3% by weight of rubber-modified polystyrene resin
(D) 15 to 1% by weight of at least one selected from an aromatic polycarbonate resin and a polystyrene-maleic anhydride copolymer,
The polybutylene terephthalate resin composition is characterized by being blended with each other (provided that the total amount of (A) to (D) is 100% by weight).

  The second gist of the present invention resides in a molded product obtained by molding the polybutylene terephthalate resin composition described in the first gist.

  According to the present invention, a polybutylene terephthalate resin composition having a low specific gravity, excellent in texture transferability, small shrinkage, excellent in mechanical strength and high-temperature moldability, and texture formed by molding the same is transferred well. Molded products can be used for highly designed automotive parts, electrical and electronic parts, machine parts, building material parts, luggage products such as trunks (daily necessities), and the like. Moreover, since the flame retardancy can be imparted to the resin composition of the present invention, it is suitable for use in electrical system parts such as gas stove parts and parts around a heating appliance (switches, etc.) that require designability and flame retardancy. It is.

(A) Polybutylene terephthalate resin (A) Polybutylene terephthalate resin (hereinafter referred to as PBT resin) which is the first resin component constituting the polybutylene terephthalate resin composition (hereinafter referred to as PBT resin composition) of the present invention. ) Is a polymer or copolymer having an ester group composed of a dicarboxylic acid unit containing terephthalic acid as a main component and a diol unit containing tetramethylene glycol as a main component in a chain unit, It is obtained by polycondensation reaction containing dicarboxylic acid or its ester derivative and diol as main components.

  Examples of dicarboxylic acid units that may be contained in addition to terephthalic acid include isophthalic acid, orthophthalic acid, 1,5-naphthalenedicarboxylic acid, 2,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, biphenyl-2, 2'-dicarboxylic acid, biphenyl-3,3'-dicarboxylic acid, biphenyl-4,4'-dicarboxylic acid, bis (4,4'-carboxyphenyl) methane, anthracene dicarboxylic acid, 4,4'-diphenyl ether dicarboxylic acid Aromatic dicarboxylic acids such as 1,4-cyclohexanedicarboxylic acid, alicyclic dicarboxylic acids such as 4,4′-dicyclohexyldicarboxylic acid, and aliphatic dicarboxylic acids such as adipic acid, sebacic acid, azelaic acid, dimer acid, etc. Is mentioned.

  Examples of the diol unit that may be contained in addition to tetramethylene glycol include aliphatic or alicyclic diols having 2 to 20 carbon atoms, bisphenol derivatives, and the like. Specific examples include ethylene glycol, propylene glycol, 1, 5-pentanediol, 1,6-hexanediol, neopentyl glycol, decamethylene glycol, cyclohexanedimethanol, 4,4'-dicyclohexylhydroxymethane, 4,4'-dicyclohexylhydroxypropane, ethylene oxide addition diol of bisphenol A, etc. Can be mentioned. Furthermore, triols such as glycerin and trimethylolpropane can also be used.

  Among the above-mentioned (A) PBT resins of the present invention, a polybutylene terephthalate homopolymer having terephthalic acid as the only dicarboxylic acid unit and tetramethylene glycol as the only diol unit is preferable. Of course, it may be a polybutylene terephthalate copolymer containing at least one dicarboxylic acid other than terephthalic acid as the dicarboxylic acid unit and / or at least one diol other than tetramethylene glycol as the diol unit. As (A) PBT resin of this invention, the ratio of the terephthalic acid in a dicarboxylic acid unit becomes like this. Preferably it is 90 mol% or more, More preferably, it is 95 mol% or more. Similarly, the proportion of tetramethylene glycol in the diol unit is preferably 90 mol% or more, more preferably 95 mol% or more.

  The intrinsic viscosity of the (A) PBT resin of the present invention is preferably 0.5 to 1.5 dl / g measured at 30 ° C. in a 1: 1 (weight ratio) tetrachloroethane and phenol mixed solvent, more preferably 0.6 to 1.3 dl / g.

(B) Polyester resin A polyester resin other than polybutylene terephthalate, which is the second resin component constituting the PBT resin composition of the present invention, (B) has a crystallization temperature of 140 to 210 ° C., manufactured by SEIKO The temperature is raised from room temperature to 300 ° C. by DSC at 20 ° C./min, then held at 300 ° C. for 3 minutes, and then the peak temperature (crystallization temperature) that appears when the temperature is lowered at 20 ° C./min is 140 to 210 ° C. Polyester resin. In this invention, the crystallization temperature of (B) polyester resin becomes like this. Preferably it is 145-195 degreeC, More preferably, it is 155-185 degreeC.

Preferable examples of the (B) polyester resin of the present invention include a polyalkylene terephthalate resin and an alicyclic polyester resin from the viewpoint of utilizing the heat resistance of the PBT resin. (B) When the polyester resin is a polyalkylene terephthalate resin, the crystallization temperature is 140 to 210 ° C, more preferably 160 to 200 ° C, and particularly preferably 170 to 190 ° C. When the (B) polyester resin is an alicyclic polyester resin, the crystallization temperature is preferably 140 to 210 ° C, more preferably 150 to 190 ° C, and particularly preferably 160 to 180 ° C.

The polyalkylene terephthalate resin, which is a preferred example of the above-mentioned (B) polyester resin, is a terephthalate having 2 to 6 carbon atoms of an alkylene group such as polyethylene terephthalate, polytrimethylene terephthalate, polyhexamethylene terephthalate, polypentamethylene terephthalate. Resins are preferred, and among them, polyethylene terephthalate resin (hereinafter sometimes abbreviated as PET resin) is more preferred.
The polyalkylene terephthalate resin is preferable in that it is highly miscible with the PBT resin and has high mechanical strength and high-temperature rigidity when blended with the PBT resin.

  The PET resin as the polyester resin (B) of the present invention is a polyethylene terephthalate polymer having terephthalic acid as the main component of dicarboxylic acid units and ethylene glycol as the main component of diol units, and a dicarboxylic acid other than the above-mentioned terephthalic acid. It may be a polyethylene terephthalate copolymer containing one or more and / or one or more diols other than the above-mentioned ethylene glycol as the diol unit, for example, a polyethylene terephthalate / isophthalate copolymer. Here, as (B) PET resin, the ratio of the terephthalic acid in a dicarboxylic acid unit becomes like this. Preferably it is 90 mol% or more, More preferably, it is 95 mol% or more. Similarly, the proportion of ethylene glycol in the diol unit is preferably 90 mol% or more, more preferably 95 mol% or more.

  (B) An alicyclic polyester resin (hereinafter sometimes abbreviated as PCC), which is another preferred example of the polyester resin, comprises 1,4-cyclohexanedicarboxylic acid as a dicarboxylic acid component, and 1,4-cyclohexanedi It is a polyester polymer with the glycol component which has methanol as a main component. Examples of the glycol component other than 1,4-cyclohexanedimethanol include ethylene glycol, trimethylene glycol, tetramethylene glycol, and poly (oxyalkylene) glycol, but a condensate of alkylene glycol having 2 to 5 carbon atoms. The poly (oxyalkylene) glycol is preferred. When a low molecular weight glycol is copolymerized, the melting point tends to decrease rapidly.

The alicyclic polyester resin of the present invention is more preferably a polyester polymer having repeating units from the following carboxylic acid component (a) and glycol component (b).
(A) dicarboxylic acid component: a component composed of 1,4-cyclohexanedicarboxylic acid having a trans isomer content of 70% or more, more preferably 80% or more,
(B) Glycol component:
(B-1) Condensation of trans isomer content of 50% or more, further 100% to 90% by mole of 1,4-cyclohexanedimethanol having 60% or more, and (b-2) alkylene glycol having 2 to 5 carbon atoms. Poly (oxyalkylene) glycol having a molecular weight of 500 to 2000, 0 to 10 mol%,
Ingredients consisting of

When the ratio of the trans isomers of 1,4-cyclohexanedicarboxylic acid and 1,4-cyclohexanedimethanol is less than 70% and 50%, respectively, the melting point is lowered and the heat resistance tends to be lowered. In addition, the content of poly (oxyalkylene) glycol in the glycol component is preferably 0 to 7 mol% in the ratio with 1,4-cyclohexyldimethanol, and more preferably from the viewpoint of heat resistance, When it exceeds 10 mol%, the melting point tends to decrease. The poly (oxyalkylene) glycol is preferably poly (oxytetramethylene) glycol, and the molecular weight thereof is more preferably in the range of 700 to 1500. An alicyclic polyester resin that satisfies the above-described conditions provides excellent mechanical properties without impairing heat resistance and crystallinity.
These alicyclic polyester resins are produced by polymerization by a known method shown in, for example, US Pat. No. 2,891,930 or US Pat. No. 2,901,466.

  In the resin composition of the present invention, the above-mentioned (B) polyester resin is used as (B) :( A) in the range of 1:90 to 1: 1, preferably 1:50 to 1 with respect to (A) PBT resin. : 2, more preferably in a ratio (weight ratio) of 1:30 to 1: 4.

(C) Rubber-modified polystyrene resin (C) Rubber-modified polystyrene resin, which is the third component constituting the PBT resin composition of the present invention, is obtained by mixing a rubbery polymer in polystyrene. As a mixing method, (1) a method of mechanically blending both, (2) a so-called graft copolymerization method in which a styrene monomer or the like is graft copolymerized in the presence of a rubbery polymer, The graft polymer obtained by the method includes a so-called graft-blend method in which polystyrene obtained by another method is mixed. In order to obtain good compatibility, among these methods, (2) or ( Those obtained by 3) are preferred.

  As the graft copolymerization method described above, an emulsion polymerization method, a solution polymerization method, a suspension polymerization method, or the like can be applied. Such a rubber-modified polystyrene resin is generally called high impact polystyrene (HIPS).

  (C) Specific examples of the rubbery polymer to be included in the rubber-modified polystyrene resin include conjugated diene rubbers such as polybutadiene, styrene-butadiene copolymer, hydrogenated styrene-butadiene block copolymer, and ethylene-propylene. Non-conjugated diene rubbers such as copolymers are exemplified, and polybutadiene is particularly preferable.

  (C) Styrene monomers constituting the rubber-modified polystyrene resin include styrene, α-methylstyrene, p-methylstyrene, bromostyrene, etc. Among them, styrene and / or α-methylstyrene is used. Is the best. As monomers other than the styrene monomer, vinyl monomers such as acrylonitrile and methyl methacrylate may be contained.

  (C) The content of the rubbery polymer in the rubber-modified polystyrene resin is preferably 1 to 40% by weight, and more preferably 3 to 30% by weight. The average rubber particle diameter is preferably 0.1 to 10, more preferably 0.2 to 5. Furthermore, even when the monomer component other than the styrene monomer is included, the total content of the rubbery polymer and the styrene monomer in the rubber-modified polystyrene resin is preferably 90% by weight or more, Furthermore, 95 weight% or more is preferable.

The MFR (melt flow rate), which is a value reflecting the molecular weight of the rubber-modified polystyrene resin, is preferably 0.5 to 15 g / 10 min in a measuring apparatus under the conditions of 200 ° C. and a load of 5 kg, more preferably 1. 0-10 g / 10 min. The number average molecular weight of the rubber-modified polystyrene resin is usually 10,000 to 300,000, preferably 20,000 to 200,000, more preferably 30,000 to 150,000, and the weight average molecular weight is usually 30,000 to 1,000,000. 50,000 to 600,000 are preferable, and 100,000 to 300,000 are more preferable.
By blending this (C) rubber-modified polystyrene resin into the resin composition, the texture transfer property and shrinkage rate are improved, and a molded product having a low specific gravity can be obtained.

(D) Aromatic polycarbonate resin and / or polystyrene-maleic anhydride copolymer The fourth resin component constituting the PBT resin composition of the present invention is a component that serves as a compatibilizing agent for rubber-modified polystyrene resin. It is at least one selected from D-1) aromatic polycarbonate resin and (D-2) polystyrene-maleic anhydride copolymer. By blending these compatibilizing agents, there is an advantage that the compatibility of (A) PBT resin and (C) rubber-modified polystyrene resin is improved and the strength is improved.

  (D-1) The aromatic polycarbonate resin can be obtained by reacting an aromatic dihydroxy compound or a small amount thereof with a phosgene or a carbonic acid diester. As aromatic dihydroxy compounds, 2,2-bis (4-hydroxyphenyl) propane (also called bisphenol A), tetramethylbisphenol A, bis (4-hydroxyphenyl) -p-diisopropylbenzene, hydroquinone, resorcinol, 4,4 -Dihydroxy diphenyl etc. are mentioned.

  The (D-1) aromatic polycarbonate resin of the present invention includes, among others, a polycarbonate resin derived from 2,2-bis (4-hydroxyphenyl) propane (also called bisphenol A), or 2,2-bis (4- Polycarbonate copolymers derived from (hydroxyphenyl) propane and other aromatic dihydroxy compounds are preferred.

  (D-1) The molecular weight of the aromatic polycarbonate resin is 10,000 to 30,000 as a viscosity average molecular weight converted from the solution viscosity measured at a temperature of 25 ° C. using methylene chloride as a solvent, preferably 12, A low-viscosity polycarbonate resin that is used as an optical disk material can be suitably used.

  The (D-2) styrene-maleic anhydride copolymer, which is another component of the fourth resin component constituting the PBT resin composition of the present invention, has a weight average molecular weight of 5 to 1,000,000, preferably The polymer is 150,000 to 400,000, more preferably 200,000 to 300,000, and the content of maleic anhydride in the styrene-maleic anhydride copolymer is usually 1 to 40% by weight, preferably 2 to 30%. % By weight, more preferably 3 to 20% by weight. The copolymerization form of styrene and maleic anhydride may be a block copolymer or a graft copolymer in addition to a normal copolymer. An example of such a copolymer is Dilark (registered trademark) manufactured by Nova Chemical Japan.

Only one of the (D-1) aromatic polycarbonate resin and the (D-2) polystyrene-maleic anhydride copolymer, which are the fourth component of the present invention, is sufficiently effective. You may mix | blend.
In the resin composition of the present invention, the blending amount of the total amount of the fourth component (D) with respect to (C) the rubber-modified polystyrene resin is 1: 100 to 1: 1 as (D) :( C), and further 1: 50 to 1: 2, in particular 1:10 to 1:25 (weight ratio). Moreover, the compounding quantity with respect to (B) polyester resin of the total amount of 4th component (D) in the resin composition of this invention is 1: 20-5: 1 as (D) :( B), Furthermore, 1: 10-2: 1, in particular 1: 5-1: 1 (weight ratio).

  The composition ratio of each of the above resin components constituting the PBT resin composition of the present invention is (A) 25 to 90% by weight, preferably 57, with respect to 100% by weight of the total amount of (A) to (D). -85 wt%, more preferably 60-80 wt%, (B) 25 to 1 wt% polyester resin other than polybutylene terephthalate having a crystallization temperature of 140 to 210 ° C, preferably 20 to 3 wt%, Preferably 15 to 4% by weight, (C) rubber-modified polystyrene resin 35 to 3%, preferably 30 to 5% by weight, more preferably 25 to 7% by weight, and (D) aromatic polycarbonate resin and / or styrene The maleic anhydride copolymer is 15 to 1% by weight, preferably 13 to 2% by weight, and more preferably 10 to 3% by weight.

  In the PBT resin composition of the present invention, the total amount of the resin components of component (A) and component (B) described above is 50 to 96% by weight, preferably 60 to 93% by weight, more preferably 70 to 90% by weight. It is good to be. When the total amount of the component (A) and the component (B) is less than 50% by weight, the mechanical strength, heat resistance, moldability, fluidity and the like, which are the characteristics of the polyester resin, tend not to be expressed. On the other hand, when the polyester resin component exceeds 96% by weight, reduction in molding shrinkage and weight reduction due to (C) rubber-modified polystyrene resin and (D) aromatic polycarbonate resin and / or styrene-maleic anhydride copolymer. The effect tends to be insufficient.

(E) Flame retardant In this invention, in addition to each resin component mentioned above, a (E) flame retardant can further be mix | blended as needed. (E) As the flame retardant, any of flame retardants widely used in resins can be used. Specifically, organic halogen compounds such as brominated flame retardants, and antimony such as antimony oxide as flame retardant aids. And hydrated inorganic compounds such as magnesium compounds, nitrogen compounds such as cyanuric acid and melamine, phosphorus compounds such as red phosphorus and phosphoric acid, and the like.

  As the flame retardant (E) of the present invention, an organic halogen compound such as a brominated flame retardant is preferable. Specifically, an epoxy oligomer of tetrabromobisphenol A, poly (pentabromobenzyl acrylate), polybromophenyl ether, Brominated polystyrene, brominated epoxy, brominated imide, brominated polycarbonate and the like are preferred. Further, poly (pentabromobenzyl acrylate), tetrabromobisphenol A epoxy oligomer, and brominated polycarbonate are particularly preferred from the viewpoint of good thermal stability.

Moreover, it is preferable to mix | blend an antimony type compound as a flame retardant adjuvant, and specific examples include antimony trioxide (Sb ₂ O ₃ ), antimony tetroxide (Sb ₂ O ₄ ), and antimony pentoxide (Sb ₂ O _5). It is preferable to mix antimony oxide such as), double salts of these antimony oxides with other metals, antimonate such as sodium antimonate, and the like.
The flame retardant (E) of the present invention is 1 to 50 parts by weight, more preferably 3 to 45 parts by weight, particularly 10 parts per 100 parts by weight of the total amount of the resin components comprising (A) to (D). It is preferable to add -40 parts by weight, and if it exceeds 50 parts by weight, the strength tends to decrease. In order to improve flame retardancy, it is preferable to add 1 part by weight or more.

(F) Inorganic filler In addition to each resin component mentioned above in this invention, (F) inorganic filler can be further mix | blended as needed. (F) As an inorganic filler, a fibrous material, a plate-shaped material, a granular material, and these mixtures are mentioned. Specifically, glass fibers, carbon fibers, mineral fibers, metal fibers, ceramic whiskers, wollastonite and other fibrous materials, glass flakes, mica, talc, lamellar silicate plates, silica, alumina, glass beads Well-known materials such as granular materials such as carbon black and calcium carbonate are included. The type of (F) inorganic filler to be blended is selected according to the required characteristics of the product. However, when importance is placed on mechanical strength and rigidity, fibrous materials, particularly glass fibers, are selected. When importance is attached to reduction of directionality and warpage, a plate-like object, particularly mica, is selected. In addition, an optimum granular material is selected based on an overall balance in consideration of fluidity during molding.

  (F) When glass fiber is used as the inorganic filler, it is preferably glass fiber that has been treated with a sizing agent. By treating the glass fiber with the sizing agent, handling workability of the glass fiber can be improved and damage to the glass fiber can be prevented. Examples of the sizing agent to be used include resin emulsions such as vinyl acetate resin, ethylene / vinyl acetate copolymer, acrylic resin, epoxy resin, polyurethane resin, and polyester resin.

  In the present invention, (F) the inorganic filler is 1 to 100 parts by weight, more preferably 5 to 80 parts by weight, particularly 100 parts by weight of the total amount of the resin components comprising (A) to (D). It is preferable to mix 10 to 60 parts by weight, and when it exceeds 100 parts by weight, there is a tendency to cause a decrease in strength, and in order to improve mechanical properties, it is preferable to add 1 part by weight or more. In the present invention, by blending the inorganic filler (F), the molded product obtained from the PBT resin composition has an advantage of excellent tensile strength and molding shrinkage.

Other Components Various release agents can be blended in the PBT resin composition of the present invention, specifically, from fatty acid residues having 12 to 36 carbon atoms and alcohol residues having 1 to 36 carbon atoms. At least one mold release agent selected from the group consisting of fatty acid esters, paraffin waxes and polyethylene waxes. Among these, the blending of polyethylene wax having a molecular weight of 900 to 8000 is preferable in that the dispersibility of polyolefin is good. The compounding amount of the release agent is preferably 0.01 to 2% by weight with respect to 100 parts by weight of the total amount of the resin components composed of (A) to (D) described above.

  The PBT resin composition of the present invention can be blended with an organophosphorus compound from the viewpoint of improving heat stability and heat retention stability. Examples of the organic phosphorus compound include an organic phosphate compound, an organic phosphite compound, an organic phosphonite compound, and the like. Among these, an organic phosphate compound is preferable. Moreover, you may use an organic phosphorus compound in combination of 1 type, or 2 or more types.

  As the organic phosphate compound, a long-chain dialkyl acid phosphate compound represented by the following general formula (1) is preferable in that the effect of heat stability is high.

（一般式（１）中、Ｒ¹及びＲ²は、各々独立して、炭素数８〜３０のアルキル基を表す。）

(In general formula (1), R ¹ and R ² each independently represents an alkyl group having 8 to 30 carbon atoms.)

Specific examples of the alkyl group having 8 to 30 carbon atoms represented by R ¹ or R ² in the general formula (1) include octyl group, 2-ethylhexyl group, isooctyl group, nonyl group, isononyl group, decyl group, isodecyl group. Group, dodecyl group, tridecyl group, isotridecyl group, tetradecyl group, hexadecyl group, octadecyl group, eicosyl group, triacontyl group, and the like. Among them, those having 12 to 25 carbon atoms, more preferably 15 to 20 carbon atoms are preferable.

  Specific examples of the long-chain dialkyl acid phosphate compound represented by the general formula (1) include dioctyl phosphate, di (2-ethylhexyl) phosphate, diisooctyl phosphate, dinonyl phosphate, diisononyl phosphate, didecyl phosphate, Examples thereof include diisodecyl phosphate, dilauryl phosphate, ditridecyl phosphate, diisotridecyl phosphate, dimyristyl phosphate, dipalmityl phosphate, distearyl phosphate, dieicosyl phosphate, ditriacontyl phosphate and the like. Of these, distearyl phosphate, dipalmityl phosphate, and dimyristyl phosphate are preferable.

  The compounding amount of the organophosphorus compound is 0.01 to 0.5 parts by weight, more preferably 0.05 to 0.3 parts per 100 parts by weight of the total amount of the resin components composed of (A) to (D). It is preferable that it is 0.1 to 0.2 weight part by weight. When the compounding amount of the organophosphorus compound is less than 0.01 parts by weight, the effect of improving the heat stability and heat retention stability of the material inherent to the organophosphorus compound tends to be hardly exhibited, and the compounding amount is 0. When the amount exceeds 5 parts by weight, there is a tendency to adversely affect performances other than heating stability and residence stability.

  In the PBT resin composition of the present invention, various additives other than the above-mentioned mold release agent and organic phosphorus compound can be blended within a range that does not impair the object of the present invention. Additives include crystallization accelerators (such as talc), antioxidants, UV absorbers, heat stabilizers, lubricants, colorants including pigments and dyes, foaming agents, crosslinking agents (epoxy compounds, acid anhydrides, isocyanates) Compounds), anti-dripping agents (fluorine-containing resins, etc.).

  In the PBT resin composition of the present invention, other thermoplastic resins (for example, acrylic resin, polyamide, polyphenylene sulfide resin, liquid crystal polyester resin, polyacetal, polyphenylene oxide) and thermosetting resins (for example, phenol) are included in the PBT resin composition of the present invention as necessary. Resin, melamine resin, silicone resin, epoxy resin) and the like.

Production method of PBT resin composition and molded product The production method of the PBT resin composition of the present invention is not limited to a specific method, but is preferably a method of melt-kneading each component, and is usually used for thermoplastic resins. Any kneading method can be applied. Specifically, for example, after each resin component (A) to (D) is uniformly mixed with other additional components, if necessary, using a Henschel mixer, a ribbon blender, a V-type blender, etc. It can knead | mix using kneading machines, such as a shaft kneading extruder, a roll, a Banbury mixer, and a Laboplast mill (Brabender). Each resin component (A) to (D), including other additional components, may be fed all at once to the kneader or sequentially. Further, two or more kinds of components selected from each resin component including an additional component may be mixed in advance, and this mixture may be fed to a kneader.

The molding method of the PBT resin composition of the present invention is not particularly limited, and a molding method generally used for thermoplastic resins can be applied. Specifically, an injection molding method, a hollow molding method, an extrusion method can be applied. A molding method such as a molding method or a press molding method can be applied.
With the PBT resin composition of the present invention, it is possible to provide a molded article having a low specific gravity which is excellent in texture transferability, has a small shrinkage rate, and is excellent in mechanical strength and high temperature moldability. In addition, since this molded article has a good transfer of wrinkles, it can be used for highly-designed automobile parts, electrical and electronic parts, machine parts, building material parts, trunk bags and other bag products (daily necessities). Moreover, since the flame retardancy can be imparted to the resin composition of the present invention, it is suitable for use in electrical system parts such as gas stove parts and parts around a heating appliance (switches, etc.) that require designability and flame retardancy. It is.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not restrict | limited to a following example, unless the summary is exceeded.

[Raw materials used in Examples and Comparative Examples]
The raw materials used in the examples and comparative examples are as follows.
(A) PBT: Polybutylene terephthalate resin (Novaduran (registered trademark) 5008 manufactured by Mitsubishi Engineering Plastics Co., Ltd., intrinsic viscosity [η] = 0.85)

(B) Polyester resin other than PBT resin (B-1) PET: Polyethylene terephthalate resin (Novapex GS385 manufactured by Mitsubishi Chemical Corporation, intrinsic viscosity [η] = 0.65, crystallization temperature 183 ° C., melting point 256 ° C., specific gravity 1.34)
Here, the crystallization temperature appears when DSC manufactured by SEIKO is heated from room temperature to 300 ° C. at 20 ° C./min, held at 300 ° C. for 3 minutes, and then cooled at 20 ° C./min. The peak temperature (crystallization temperature) was measured. The same applies to the following PCCs.
(B-2) PCC: alicyclic polyester resin produced by the method of Production Example 1 below (crystallization temperature: 165 ° C., melting point: 225 ° C., specific gravity: 1.14)

(C) HIPS: Rubber-modified polystyrene resin (Dialex HT478 manufactured by A & M, content of rubber polymer (polybutadiene) 8.8% by weight, average rubber particle diameter 1.8 μm, number average molecular weight 92,000, weight Average molecular weight 230,0000, MFR (temperature 200 ° C., load 5 kgf) 1.8 g / 10 min)
(D) Compatibilizer (D-1) PC: Aromatic polycarbonate resin (Mitsubishi Chemical Corporation Novalex (registered trademark) 7020AD2 raw material powder, viscosity average molecular weight about 15,000)
(D-2) M-PS: Styrene-maleic anhydride copolymer (Dilark D232 made by Nova Chemical Japan, content of maleic anhydride 9% by weight, weight average molecular weight 240,000, MFR (temperature 230 ° C. , Load 2.16kgf) 2.0g / 10min)

(E) Flame retardant (E-1) Br-PC: Brominated polycarbonate oligomer (FR-53 manufactured by Mitsubishi Engineering Plastics Co., Ltd.)
(E-2) Sb ₂ O ₃ : Antimony trioxide (Moroku 6)
(F) Inorganic filler (GF): Glass fiber (T-187 manufactured by Nippon Electric Glass Co., Ltd.)

<Example of production of alicyclic polyester resin>
A stainless steel reactor equipped with a stirrer, a reflux condenser, a heating device, a pressure gauge, a thermometer, and a pressure reduction device was charged with 101.5 parts by weight of trans-1,4-cyclohexanedicarboxylic acid (trans body 100%), 1, 4 -87.5 parts by weight of cyclohexanedimethanol (trans isomer: cis cis ratio of about 7: 3 (molar ratio)) and 0.005 part by weight of a 6 wt% butanol solution of tetra-n-butyl titanate. The inside of the reactor was replaced with nitrogen gas. While flowing nitrogen gas through the reactor, the temperature was raised to 200 ° C. to carry out the esterification reaction for 1 hour. Thereafter, the polycondensation reaction was started while raising the temperature to 250 ° C. and reducing the pressure in the reactor. After maintaining the pressure in the reactor at 0.1 KPa and the temperature at 250 ° C., a polycondensation reaction was carried out for 2.2 hours to complete the reaction. After completion of the polycondensation reaction, the obtained resin was drawn out into strands in water and cut into alicyclic polyester resin pellets. Hereinafter, this resin is abbreviated as PCC.

[Method for Producing PBT Resin Composition]

  Each resin component was uniformly mixed with a tumbler mixer so as to have the ratio shown in Table-1 and Table-2, and then used with a twin-screw extruder (TEX30XCT manufactured by Nippon Steel Works, L / D = 42, number of barrels 12). The mixture of each resin component was fed from the barrel 1 under the conditions of a cylinder temperature of 260 ° C. and a screw rotation speed of 400 rpm, and melt mixed to produce a PBT resin composition. Moreover, in the example which mix | blended (F) inorganic filler, resin components other than an inorganic filler are mixed uniformly with a tumbler mixer, the mixture is fed from the barrel 1 and melt-mixed, and then from the barrel 5 ( F) An inorganic filler was fed and melt-mixed to produce a PBT resin composition. The results of the following evaluations are shown in Table-1 and Table-2 for molded articles obtained from the obtained resin composition.

[Method of evaluating physical properties of molded products]
(1) Wrinkle transfer property: Using a die having a width of 40 mm, a length of 100 mm, and a thickness of 2 mm, which has been subjected to a surface treatment with an injection molding machine (PS40 manufactured by Nissei Co., Ltd.), a cylinder temperature of 250 ° C. and a mold temperature of 40 Molding was performed under conditions of ° C and a filling time of 1.6 seconds to obtain a molded product. Sensory evaluation was performed on the feel of the textured transfer surface of the molded product. In Table-1 and Table-2, the thing with a rough feeling was set to (circle), and the thing with little rough feeling was set to x.
Furthermore, using a surface roughness measuring machine Surfcom 3000A manufactured by Tokyo Seimitsu, the ten-point average roughness Rz of the embossed transfer surface of the molded product was measured in accordance with JIS-B0601 standard. Since the ten-point average roughness of the mold texture surface is 22 μm, it is considered that the texture transfer property is better as the measured value of the molded product is closer to 22 μm.

(2) Tensile strength: Tensile strength was measured according to ISO 527 for tensile test pieces molded under conditions of a cylinder temperature of 250 ° C. and a mold temperature of 80 ° C. using an injection molding machine (SG75M manufactured by Sumitomo Heavy Industries). .
(3) Specific gravity: About the tensile test piece shape | molded by said method, the weight in the air and the weight in water were measured using the Shimadzu Corporation electronic specific gravity meter AW320, and specific gravity was calculated | required.

(4) Mold Shrinkage: Using an injection molding machine (SG75M manufactured by Sumitomo Heavy Industries), a rectangular flat plate having a length of 100 mm, a width of 100 mm, and a thickness of 2 mm under the conditions of a cylinder temperature of 250 ° C. and a mold temperature of 80 ° C. is a film gate. Molding was performed using a mold, and molding shrinkage in the flow direction (MD) and the direction perpendicular to the flow (TD) was measured.
(5) Flame retardancy: Using a injection molding machine (SG75M manufactured by Sumitomo Heavy Industries, Ltd.), a test piece having a thickness of 0.8 mm molded under conditions of a cylinder temperature of 250 ° C. and a mold temperature of 80 ° C. is based on UL94. The flammability was evaluated.

（１）実施例２，３と比較例２、実施例５と比較例５とを各々比較すると、本発明の特定の（Ｂ）ポリエステル樹脂を配合した実施例においては、配合しない比較例に比べて、シボ転写性及び成形収縮率が優れることが分かる。
（２）実施例４と比較例３とを比較すると、本発明の特定の（Ｂ）ポリエステル樹脂の配合量が２５重量％を超えると、引張強度が低下することが分かる。

(1) When Examples 2 and 3 are compared with Comparative Example 2 and Example 5 and Comparative Example 5 are compared with each other, in the Example in which the specific (B) polyester resin of the present invention is blended, compared with the Comparative Example without blending Thus, it is understood that the texture transfer property and the molding shrinkage ratio are excellent.
(2) When Example 4 and Comparative Example 3 are compared, it can be seen that when the blending amount of the specific (B) polyester resin of the present invention exceeds 25% by weight, the tensile strength decreases.

(3) When Examples 1 and 2 and Comparative Example 1 are compared with Examples 5 and 6 and Comparative Example 4, respectively, when the components (C) and (D) of the present invention are blended, these are not blended. It can be seen that not only the mold shrinkage but also the texture transfer property is excellent.
(4) When Examples 7 and 8 are compared with Examples 2 and 3, when (F) inorganic filler is blended, the tensile strength and molding shrinkage ratio are superior to those when not blending these. I understand.

Claims (7)

(A) 25-90% by weight of polybutylene terephthalate resin,
(B) 25 to 1% by weight of a polyester resin other than polybutylene terephthalate having a crystallization temperature of 140 to 210 ° C.
(C) 35-3% by weight of rubber-modified polystyrene resin
(D) 15 to 1% by weight of at least one selected from an aromatic polycarbonate resin and a polystyrene-maleic anhydride copolymer,
A polybutylene terephthalate resin composition, wherein each is blended (however, the total amount of (A) to (D) is 100% by weight).   (B) The polybutylene terephthalate resin composition of Claim 1 whose compounding quantity of the said polyester resin is 20 to 3 weight%.   (B) The polybutylene terephthalate resin composition according to claim 1 or 2, wherein the polyester resin is a polyalkylene terephthalate resin.   (B) The polybutylene terephthalate resin composition according to claim 1, wherein the polyester resin is an alicyclic polyester resin.   The polybutylene according to any one of claims 1 to 4, wherein (E) the flame retardant is blended in an amount of 1 to 50 parts by weight with respect to 100 parts by weight of the total amount of the resin components comprising (A) to (D). Terephthalate resin composition.   The inorganic filler is blended in an amount of 1 to 100 parts by weight with respect to 100 parts by weight of the total amount of the resin components consisting of (A) to (D). Butylene terephthalate resin composition.   A molded article obtained by molding the polybutylene terephthalate resin composition according to any one of claims 1 to 6.