JP4438471B2 - Polyester resin composition - Google Patents

Description

  The present invention relates to a polyester resin composition, and more particularly to a polyester resin composition excellent in flame retardancy, heat resistance, high impact property, high strength, and low warpage.

  Thermoplastic polyester resins, especially polybutylene terephthalate resins, have excellent heat resistance, moldability, chemical resistance, electrical insulation, and other suitable properties as engineering plastics. It is used for applications such as parts, electrical parts, machine parts and construction parts. However, since the thermoplastic polyester resin alone has low mechanical strength and impact strength, a fibrous reinforcing material is usually added to avoid the drawbacks. However, the fibrous reinforcing material has high fiber anisotropy and warpage is remarkable. Therefore, a method of blending AS resin or the like is known in order to suppress the occurrence of warping in a system in which a fibrous reinforcing material is added to a thermoplastic polyester resin.

A thermoplastic polyester resin composition obtained by blending a polybutylene terephthalate resin and an AS resin is blended with a thermoplastic polyester, a styrene resin, and a halogenated bisphenol A type epoxy resin as described in Patent Document 1, for example. Therefore, a thermoplastic polyester resin composition excellent in flame retardancy and low warpage has been proposed. Further, as described in Patent Document 2, for example, by blending a thermoplastic polyester and an epoxy group-containing vinyl polymer, in addition to mechanical properties, heat resistance, and impact resistance, it is excellent in low warpage. Thermoplastic polyester resin compositions have been proposed.
JP 2003-26904 A JP-A-6-287422

However, the thermoplastic polyester resin composition described in Patent Document 1 has a problem that the styrenic resin is inferior in terms of compatibility with the thermoplastic polyester and causes a decrease in mechanical properties.
Moreover, since the thermoplastic polyester resin composition described in Patent Document 2 has a low viscosity of the epoxy group-containing vinyl polymer, it is considered that the dispersion diameter of the polymer in the thermoplastic polyester increases. Sufficient warpage is not exhibited.

As a result of diligent research to solve the problems of the prior art, the present inventors have completed the present invention, and the object is low warpage and flame retardancy, and mechanical strength. Is a good polyester resin composition. That is, the present invention includes (1) 100% by weight of the entire resin composition, (A) 30 to 80% by weight of a thermoplastic polyester resin, (B) 1 to 20% by weight of an epoxy group-containing vinyl copolymer, (C ) Composed of 0-50% by weight of glass fiber, (D) 3-20% by weight of brominated flame retardant, (E) 1-10% by weight of antimony compound, and measured with 0.2% dimethylformamide solution of (B) Polyester having a reduced viscosity of 0.7 to 0.9, a brominated flame retardant of (D) being brominated epoxy, having both ends blocked with tribromophenol, and a molecular weight of 2000 to 4000 Resin composition,
(2) The polyester-based resin composition according to claim 1, wherein the thermoplastic polyester resin (A) is polybutylene terephthalate,
(3) (B) Epoxy group-containing vinyl copolymer is (B-1) vinyl cyanide monomer, (B-2) aromatic vinyl monomer, (B-3) epoxy group-containing vinyl monomer. A polyester resin composition according to claim 1 or 2, which is a copolymer obtained by polymerizing a monomer as a main component.
(4) The weight ratio of each monomer of (B) epoxy group-containing vinyl copolymer is (B-1) 22-25 parts by weight of vinyl cyanide monomer, (B-2) aromatic vinyl monomer 74 to 77 parts by weight of a monomer, (B-3) 0.1 to 0.5 parts by weight of an epoxy group-containing vinyl monomer, The polyester resin composition according to any one of claims 1 to 3,
(5) The polyester resin composition according to any one of claims 1 to 4, which is 1/32 inch V0.

  The polyester-based resin composition of the present invention is a resin composition excellent in flame retardancy, heat resistance, high impact properties, high strength, and low warpage. Taking advantage of such properties, cases as electrical and electronic parts, It can be used for covers, fixing machine parts, electrical parts, etc.

The present invention is described in detail below.
The thermoplastic polyester used in the present invention includes a polymer or copolymer obtained by a polycondensation reaction mainly composed of a dicarboxylic acid (or an ester-forming derivative thereof) and a diol (or an ester-forming derivative thereof). Can be used.

  Examples of the dicarboxylic acid include terephthalic acid, isophthalic acid, orthophthalic acid, 1,5-naphthalenedicarboxylic acid, 2,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 2,2 ″ -biphenyldicarboxylic acid, 3,3 '-Biphenyl dicarboxylic acid, 4,4'-biphenyl dicarboxylic acid, 4,4'-diphenyl ether dicarboxylic acid, 4,4'-diphenylmethane dicarboxylic acid, 4,4'-diphenylsulfone dicarboxylic acid, 4,4'-diphenyl isopropyl Redene dicarboxylic acid, 1,2-bis (phenoxy) ethane-4,4'-dicarboxylic acid, 2,5-anthracene dicarboxylic acid, 2,6-anthracene dicarboxylic acid, 4,4'-p-terphenylene dicarboxylic acid, 2,5-pyridinedicarboxylic acid and the like, terephthalic acid It can be preferably used.

  These dicarboxylic acids may be used by mixing two types of abnormalities. In addition, it is possible to use a mixture of one or more alicyclic dicarboxylic acids such as adipic acid, azelaic acid, dodecanedioic acid, sebacic acid and the like, and cyclohexanedicarboxylic acid together with these dicarboxylic acids in a small amount. it can.

  Examples of the diol component include ethylene glycol, propylene glycol, butylene glycol, hexylene glycol, neopentyl glycol, 2-methyl 1,3-propanediol, diethylene glycol, triethylene glycol and other aliphatic diols, 1,4-cyclohexane. Examples thereof include alicyclic diols such as dimethanol, and mixtures thereof. If the amount is small, one or more long-chain diols having a molecular weight of 400 to 6,000, that is, polyethylene glycol, poly-1,3-propylene glycol, polytetramethylene glycol, and the like may be copolymerized.

  Preferable examples of these polymers and copolymers include polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polyethylene-1,2-bis (phenoxy) ethane-4,4'-. In addition to dicarboxylate, there may be mentioned copolyesters such as polyethylene isophthalate / terephthalate, polybutylene terephthalate / isophthalate, polybutylene terephthalate / decane dicarboxylate. Of these, polybutylene terephthalate can be preferably used. These thermoplastic polyester resins preferably have a relative viscosity in the range of 1.2 to 2.0 when measured with a 0.5% o-chlorophenol solution at 25 ° C. Within the above range, a composition having excellent mechanical properties and excellent moldability can be obtained. The thermoplastic polyester resin (hereinafter also referred to as component (A)) is at least one acid component selected from terephthalic acid, 2,6-naphthalenedicarboxylic acid, isophthalic acid, and the like, ethylene glycol, propylene glycol, butylene It is obtained by polycondensation with at least one diol component selected from glycol, hexylene glycol, polyethylene glycol, polyalkylene glycol such as polytetramethylene glycol, and the like. Specifically, polybutylene terephthalate (PBT) , Polypropylene terephthalate (PPT), polyethylene terephthalate (PET), polyhexylene terephthalate (PHT), polyethylene naphthalate (PEN), polybutylene naphthalate (PBN), polycyclohexa In addition to such 1,4-dimethylolcyclohexane terephthalate, and the like polyethylene isophthalate terephthalate (PET / I), polybutylene isophthalate-isophthalate (PET / I) copolymerized polyesters such as.

  The (A) thermoplastic polyester resin in the present invention needs to be 30 to 80% by weight, with the entire resin composition being 100% by weight. Preferably it is 40 to 70% by weight. If it is less than 30% by weight, mechanical properties are impaired, and if it is 80% by weight or more, sufficient combustibility and low warpage cannot be exhibited.

  Examples of the (B-1) vinyl cyanide monomer in the component (B) used in the present invention include acrylonitrile, methacrylonitrile, ethacrylonitrile, fumaronitrile, and among them, acrylonitrile is preferable. In addition, 22-25 weight part of (B-1) vinyl cyanide monomers are required with respect to the whole epoxy group containing vinyl-type copolymer. The amount is preferably 23 to 24 parts by weight, and if it is less than 22 parts by weight, sufficient warpage cannot be exhibited. If the amount is more than 25 parts by weight, the fluidity is impaired, which is not preferable.

  Examples of the (B-2) aromatic vinyl monomer include styrene, α-methyl styrene, p-methyl styrene, pt-butyl styrene, etc. Among them, styrene and α-methyl styrene are preferable. In addition, 74-77 weight part is required as (B-2) aromatic vinyl monomer with respect to the whole epoxy group containing vinyl-type copolymer. The amount is preferably 75 to 76 parts by weight, and if it is less than 74 parts by weight, sufficient warpage cannot be exhibited. If the amount is more than 77 parts by weight, the fluidity is impaired, which is not preferable.

  Furthermore, examples of the (B-3) epoxy group-containing vinyl monomer include glycidyl acrylate, glycidyl methacrylate, glycidyl ethacrylate, etc. Among them, glycidyl methacrylate is preferable. The (B-3) epoxy group-containing vinyl monomer in the component (B) is suitably 0.05 to 1.0% by weight, particularly 0.1 to 0.5% by weight, and 0.05% by weight. If it is less than 1, the mechanical properties, particularly impact properties are impaired, and if it exceeds 1.0% by weight, the fluidity is impaired.

Component (B) should be added in an amount of 1 to 20 parts by weight, preferably 5 to 18 parts by weight, and less than 1 part by weight has a poor effect of improving dimensional stability. Exceeding this is not preferred because the moldability is impaired. It is necessary from the viewpoint of reducing the dispersed particle size of the component (B) that the reduced viscosity (ηsp / C) measured with a 0.2% dimethylformamide solution is 0.7 to 0.9. Further, the reduced viscosity is preferably 0.75 to 0.85. If the reduced viscosity is less than 0.7, the viscosity is low, the dispersion deteriorates, and the warp is adversely affected. On the other hand, when the reduced viscosity is higher than 0.9, the injection pressure required for filling at the time of molding increases, residual stress remains in the molded product, and warpage occurs.
Further, the epoxy group-containing vinyl copolymer is 22 to 25 parts by weight of vinyl cyanide monomer, 74 to 77 parts by weight of aromatic vinyl monomer, and 0.1 to 1.0 part by weight of epoxy group-containing vinyl monomer. By making it part, it is optimal for mechanical strength and warpage.
(C) As a glass fiber of a component, it is possible to use a well-known glass fiber. The glass fiber can be added in an amount of 0 to 50% by weight.
The brominated flame retardant as the component (D) is a brominated epoxy having a structure in which both ends are blocked with tribromophenol and having a molecular weight of 2000 to 4000. The molecular weight is more preferably 2500-3500. If the molecular weight is less than 2000, the flame retardant may bleed on the surface, and if it is 4000 or more, the fluidity is not good and the injection pressure at the time of molding rises, and the residual stress remains in the molded product. There is a high possibility that the warpage will get worse.

  In addition, brominated epoxy thickens due to molding retention, making it difficult to ensure fluidity, and residual stress remains in the molded product in the same way as when the molecular weight is high.To prevent this, both ends of the flame retardant are tribromo. It is necessary to block with phenol. The amount of brominated flame retardant added is 3 to 20% by weight, and 5 to 15% by weight is particularly preferable. If it is less than 3% by weight, sufficient flame retardancy cannot be expressed. On the other hand, if it exceeds 20% by weight, the mechanical properties of the resin composition are lowered.

The antimony compound (E) can be used in combination with an organic bromine compound to synergistically improve flame retardancy, such as antimony trioxide, antimony pentoxide, sodium antimonate and antimony phosphate. The antimony compound of which surface treatment etc. are given can be used. Of these, antimony trioxide is suitable. In addition, an antimony compound needs 1 to 10 weight%. Preferably it is 3 to 8% by weight. If it is less than 1% by weight, sufficient flame retardancy cannot be expressed. On the other hand, if it exceeds 10% by weight, the mechanical properties of the resin composition are lowered.
In the polyester-based resin composition of the present invention, usual additives such as a reinforcing material, a filler, an antioxidant, a stabilizer, an ultraviolet absorber, a colorant, a release agent, etc., as long as the effects of the present invention are not impaired. And small amounts of other polymers can be added.

  Examples of the reinforcing material and filler include glass fiber, carbon fiber, asbestos fiber, rock wool, calcium carbonate, silica sand, bentonite, kaolin, clay, wollastonite, barium sulfate, glass beads, mica and the like.

  Examples of antioxidants include 2,6-di-t-butyl-4-methylphenol, tetrakis (methylene-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate) methane, tris Phenol compounds such as (3,5-di-t-butyl-4-hydroxybenzyl) isocyanurate, sulfur such as dilauryl-3,3′-thiodipropionate, dimyristyl-3,3′-thiodipropionate And phosphorous compounds such as trisnonylphenyl phosphite and distearyl pentaerythritol diphosphite.

  Stabilizers include benzotriazole compounds including 2- (2′-hydroxy-5′-methylphenyl) benzotriazole, and benzophenone compounds such as 2,4-dihydroxybenzophenone, mono- or distearyl phosphate, trimethyl phosphate And phosphoric acid esters.

  These various additives may have a synergistic effect by combining two or more kinds, and may be used in combination.

  For example, the additive exemplified as the antioxidant may act as a stabilizer or an ultraviolet absorber. Some of those exemplified as stabilizers also have an antioxidant action and an ultraviolet absorption action. In other words, the classification is for convenience and does not limit the action.

Mold release agents include plant waxes such as carnauba wax and rice wax, animal waxes such as beeswax and lanolin, mineral waxes such as montan wax, petroleum waxes such as paraffin wax and polyethylene wax, castor oil and its Derivatives, fatty acids, and oil-based waxes such as derivatives thereof, and higher fatty acid derivatives include higher fatty acids such as lauric acid, myristic acid, palmitic acid, stearic acid, and montanic acid, and monovalent or divalent or higher alcohols Esters, partially saponified by partially saponifying these higher fatty acid esters with metal oxides such as Ca (OH) ₂ , NaOH, Mg (OH) ₂ , Zn (OH) ₂ , LiOH, Al (OH) ₃ Complete saponified product obtained from an esterified ester, a higher fatty acid and a metal oxide or metal hydroxide, Grade fatty acids, complex ester condensed with dicarboxylic acids such as adipic acid as bridging agent esters of polyhydric alcohols, such as mono- or diamides derived from a higher fatty acid with a monoamine or diamine.

  As the various polymers, ABS resin, polycarbonate resin, nylon resin, PPS resin and the like can be added.

  The resin composition of the present invention is preferably flame retardant and has a 1/32 inch V0. The resin composition of the present invention may be used at a product wall thickness of 1/32 inch and needs to clear V0.

  What is necessary is just to implement about the manufacturing method of the polyester-type resin composition of this invention by the method generally known, and does not need to specifically limit. A typical example is a method of melt-kneading at a temperature of 200 to 350 ° C. using a known melt mixer such as a single-screw or twin-screw extruder, a Banbury mixer, a kneader, or a mixing roll. Each component may be mixed in advance and then melt kneaded. Alternatively, for 100 parts by weight of the total amount of the components (A) to (E), for a small amount of additive component such as 1 part by weight or less, after other components are kneaded and pelletized by the above method, It can also be added before molding. In addition, although it is better that the water | moisture content adhering to each component is less and it is desirable to dry beforehand, not all the components need to be dried.

  As an example of a preferable production method, a twin-screw extruder having a cylinder temperature of 230 to 300 ° C. is used, and a raw material containing components (A) to (E) and other additives is supplied to the extruder and kneaded. Is mentioned.

  The resin composition of the present invention is generally molded by a known thermoplastic resin molding method such as injection molding, extrusion molding, blow molding, transfer molding, vacuum molding, etc., among which injection molding is preferable.

  The polyester-based resin composition of the present invention is a resin composition excellent in flame retardancy, heat resistance, high impact properties, high strength, and low warpage. Taking advantage of such properties, cases as electrical and electronic parts, It can be used for covers, fixing machine parts, electrical parts, etc.

  Hereinafter, the present invention will be described in more detail with reference to examples.

The compounding composition used for the Example and the comparative example is shown.
(Aa) Polybutylene terephthalate resin Inherent viscosity 0.85
(Ba) (B-1) Acrylonitrile / (B-2) Styrene / (B-3) Glycidyl methacrylate copolymer The weight ratio of each component is 24 / 75.7 / 0.3 parts by weight, and the reduced viscosity. (B) epoxy group-containing vinyl copolymer (Bb) (B-1) acrylonitrile / (B-2) styrene / (B-3) glycidyl methacrylate copolymer The ratio is 24 / 75.7 / 0.3 parts by weight and the reduced viscosity is 0.49. (B) Epoxy group-containing vinyl copolymer (Bc) (B-1) Acrylonitrile / (B-2 ) Styrene / (B-3) Glycidyl methacrylate copolymer The weight ratio of each component is 24 / 75.7 / 0.3 parts by weight and the reduced viscosity is 1.74. (B) Epoxy group-containing vinyl copolymer Combined (Bd) (B-1) Acrylonitrile (B-2) Styrene / (B-3) Glycidyl methacrylate copolymer The weight ratio of each component is 18 / 8.75 / 0.25 parts by weight and the reduced viscosity is 0.79. Vinyl copolymer (Be) (B-1) Acrylonitrile / (B-2) Styrene The weight ratio of each component is 24/76 parts by weight and the reduced viscosity is 0.79. (B) Vinyl copolymer Polymer (C-a) glass fiber Fiber diameter 13 μm Fiber length 3 mm glass fiber (T-187 manufactured by Nippon Electric Glass Co., Ltd.)
(Da) Brominated flame retardant Brominated epoxy Molecular weight 3000 Flame retardant blocked with tribromophenol at both ends (Db) Brominated flame retardant Brominated epoxy Molecular weight 10000 Flame retardant without blocking at both ends (D- c) Brominated flame retardant Brominated epoxy Molecular weight 3000 Flame retardant without blocking at both ends (Dd) Brominated flame retardant Brominated epoxy Molecular weight 1900 Flame retardant blocked with tribromophenol at both ends (Ea) Antimony Compound Fire cut AT-3 from Suzuhiro Chemical.

  The Examples and Comparative Examples were evaluated by the following methods.

  (I) The tensile test was measured according to ASTM-D638 using an ASTM Type 1 dumbbell. Those with 140 MPa or less were rejected.

  (Ii) The impact test was measured according to ASTM-D256. Those of 45 J / m or less were rejected.

  (Iii) Flame retardancy was measured according to UL94 using a rod-shaped test piece (125.0 × 13.0 × 0.72 mm thickness). The test piece was injection molded, and the molding conditions were a cylinder temperature of 260 ° C. and a mold temperature of 80 ° C.

  (Iv) The viscosity increase during residence was determined by measuring the lower limit pressure after staying in the molding machine for 30 minutes, and determining that the retention rate was 120% or more as NG.

  (V) Bleed-out characteristics were determined by visually treating 150 ° C. for 50 hours using an ASTM Type 1 dumbbell, visually confirming that the flame retardant did not appear on the surface, and rejecting some.

  (Vi) The amount of inward warping is 30 mm in width, 30 mm in height, 30 mm in depth, and 1.5 mm in thickness. A box-shaped molded product is molded from the side pin gate, and the amount of inclining of the side to the inner side of the side opposite to the gate is measured. The amount of warpage was used. The thing of 0.45 mm or more was made disqualified.

  (Vii) Comprehensive judgment made all the items which do not have a rejection pass, and made what has even one failure a failure.

Examples 1-4
Components (A) to (E) were blended in combinations shown in Table 1.
The manufacturing method of the material described in each Example is as follows. That is, it was manufactured using a twin screw extruder having a screw diameter of 57 mmφ set at a cylinder temperature of 250 ° C. (A) a thermoplastic polyester resin, (B) an epoxy group-containing vinyl copolymer, (D) a bromine flame retardant, (E) an antimony compound and other additives from the base portion, and (C) glass fiber Was supplied from the side feeder and melted and kneaded. The strand discharged from the die was cooled in a cooling bath, and then pelletized by a strand cutter. Each of the obtained materials was dried for 3 hours or more with a 130 ° C. hot air dryer, and then molded and evaluated using the method described in the evaluation method. The results are also shown in Table 1. All of the obtained compositions had low warpage, mechanical strength, impact characteristics, and excellent moldability.
Table 1 shows the formulation of Examples 1 to 3 and the evaluation results.
In Examples 1 to 3 which are the polyester resin compositions of the present invention, all obtained excellent results in the amount of warpage, tensile strength, thickening during residence, bleed out, and Izod impact strength.

  Table 2 shows the formulation of the comparative examples 1 to 6 and the evaluation results.

Comparative Example 1
Manufactured and evaluated in the same manner as in Example 1 except that the epoxy group-containing vinyl copolymer of (Bb) having a reduced viscosity of 0.49 is used as the epoxy group-containing vinyl copolymer of component (B). Went. The value is lower than that of the resin composition of the present invention. As a result, the dispersion state of the epoxy group-containing vinyl copolymer is deteriorated, and the amount of inner warp is increased.

Comparative Example 2
Production and evaluation in the same manner as in Example 1 except that the epoxy group-containing vinyl copolymer (Bc) having a reduced viscosity of 1.74 as the epoxy group-containing vinyl copolymer of the component (B) was used. Went. As a result, the lower limit pressure is increased and the amount of warpage is increased.

Comparative Example 3
Production and evaluation were carried out in the same manner as in Example 1 except that the vinyl copolymer (Be) was used as the component (B). As a result, the tensile strength / Izod impact value is reduced.

Comparative Example 4
Production and evaluation were performed in the same manner as in Example 1 except that a flame retardant having a molecular weight of 10,000 (Db) and having no end-blocking agent was used as the component (D). The lower limit pressure is higher and the amount of warpage is larger.

Comparative Example 5
Production and evaluation were carried out in the same manner as in Example 1 except that a flame retardant having a molecular weight of 3000 (Dc) brominated epoxy and having no endblocker was used as the component (D). Although there was no problem in warping and physical properties, thickening during the stay occurred.

Comparative Example 6
Production and evaluation were performed in the same manner as in Example 1 except that a flame retardant blocked with tribromophenol at both ends of the molecular weight 1900 of the brominated epoxy (Dd) was used as the component (D). Although there is no problem with low warpage and physical properties, bleeding occurred in a bleed-out test after heat treatment (150 ° C. × 24 h).

Claims (5)

100% by weight of the entire resin composition, (A) 30-80% by weight of thermoplastic polyester resin, (B) 1-20% by weight of epoxy group-containing vinyl copolymer, (C) 0-50% by weight of glass fiber (D) a brominated flame retardant 3 to 20% by weight, (E) an antimony compound 1 to 10% by weight, and a reduced viscosity measured with a 0.2% dimethylformamide solution of (B) is 0.7 to 0 A polyester resin composition having a molecular weight of 2000 to 4000, having a structure in which the brominated flame retardant of (D) is brominated epoxy and both ends are blocked with tribromophenol. (A) The polyester resin composition according to claim 1, wherein the thermoplastic polyester resin is polybutylene terephthalate. (B) An epoxy group-containing vinyl-based copolymer comprises (B-1) a vinyl cyanide monomer, (B-2) an aromatic vinyl monomer, and (B-3) an epoxy group-containing vinyl monomer. The polyester resin composition according to claim 1 or 2, which is a copolymer obtained by polymerization as a main component. (B) The weight ratio of each monomer of the epoxy group-containing vinyl copolymer is (B-1) 22-25 parts by weight of vinyl cyanide monomer, (B-2) aromatic vinyl monomer 74. The polyester-based resin composition according to any one of claims 1 to 3, which is ˜77 parts by weight and (B-3) 0.1 to 0.5 parts by weight of an epoxy group-containing vinyl monomer. The polyester resin composition according to any one of claims 1 to 4, which is 1/32 inch V0.