JP2005179413A - Flame retardant polyester resin composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a flame-retardant polyester resin composition which has excellent flame retardancy and high heat resistance and can be molded with a low temperature mold. <P>SOLUTION: This flame-retardant polyester resin composition comprises (A) 100 pts. wt. of polyethylene terephthalate, (B) 3 to 30 pts. wt. of a brominated aromatic compound, (C) 1 to 20 pts. wt. of antimony trioxide compound, (D) 0.1 to 3 pts. wt. of a bisphenol A type epoxy compound having an epoxy equivalent of 500 to 1,500, (E) 20 to 125 pts. wt. of an inorganic filler, (F) 0.1 to 10 pts. wt. of an ionomer, and (G) 0.5 to 10 pts. wt. of a crystallization-accelerating agent. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a flame retardant polyester resin composition that has excellent flame resistance and high heat resistance and can be molded with a low temperature mold.

  Thermoplastic polyester resins represented by polyethylene terephthalate are used as engineering plastics, making use of their excellent heat resistance, mechanical properties, chemical resistance, etc. By adding various additives, for example, fibrous reinforcing agents such as glass fibers and carbon fibers, and function-imparting agents such as inorganic fillers, by further improving the physical properties, the application area is as described above. It is spreading.

  In addition, the shapes required for these moldings in recent years tend to be more complicated, thinner and smaller than before, reflecting social needs such as higher functionality, lighter weight, and resource saving. . Accordingly, the thermoplastic polyester resin as a molding material has become an indispensable requirement as a material characteristic that it has excellent fluidity in a mold during molding.

  It is known that the melt flowability of a thermoplastic polyester resin greatly depends on its molecular weight, and the smaller the molecular weight, the greater the fluidity. Accordingly, the thermoplastic polyester resin having excellent fluidity may be one having a low molecular weight. On the other hand, the mechanical strength of the molded product, particularly so-called toughness such as tensile elongation and bending deflection, is also used as the thermoplastic polyester resin. It is known that the lower the molecular weight, the lower the toughness strength. This means that if a thermoplastic polyester resin with a low molecular weight is used to improve the fluidity of the molding material, only moldings with low toughness strength can be obtained, especially in response to thinning of the moldings. In many cases, such as when the improvement is required, the strength reduction due to the thinning and the strength reduction due to the molecular weight reduction are combined, making it impossible to use in actual use.

  In order to improve the strength of the molded product, for example, an α-olefin and an α, β-unsaturated carboxylate, a copolymer of an acrylate ester and an ethylene, a polyacrylic acid aliphatic ester with respect to a thermoplastic polyester resin. There are known methods of adding a rubbery polymer such as butyl rubber, or various epoxy compounds, but these methods are all in the direction of deteriorating the fluidity of the thermoplastic polyester resin. Application involves substantial constraints.

  In general, for electrical and electronic parts, flame retardance is required for fire safety, a composition containing a flame retardant is applied, and the thinnest part of a molded product is specified in UL-94. The flame retardancy of rank V-0 is required. In order to make a thermoplastic polyester resin flame retardant in electrical / electronic component applications, a brominated aromatic compound and sodium antimonate are blended as disclosed in Patent Document 1 from the balance of properties and economy. Although the method is known, when sodium antimonate is used, the fluidity tends to decrease.

Furthermore, polyethylene terephthalate has a very low crystallization rate, and a crystallization accelerator is usually blended for molding at a molding temperature of 100 ° C. or lower. As a crystallization accelerator, a low molecular weight organic compound as disclosed in Patent Document 2 is known. However, when such a low molecular weight organic compound is blended, the flame retardancy is remarkably lowered and V-0 is difficult. It was further difficult to obtain a resin composition exhibiting high heat resistance over a long period of time while maintaining flammability.
JP-A-8-225719 JP-A-2-58561

  The present invention has been made against the background described above, and the object of the present invention is to provide high flame retardancy and high heat resistance over a long period of time, and furthermore, easy crystallinity that can be molded with a low-temperature mold. It is providing the flame-retardant polyester resin composition provided.

  As a result of intensive investigations to solve the above problems, the present inventors have found that it is extremely effective to combine a specific additive with polyethylene terephthalate, and that a composition in which the above problems have been achieved can be obtained. The headline and the present invention were completed.

That is, the present invention
(A) For 100 parts by weight of polyethylene terephthalate,
(B) 3 to 30 parts by weight of a brominated aromatic compound,
(C) 1-20 parts by weight of an antimony trioxide compound,
(D) 0.1-3 parts by weight of a bisphenol A type epoxy compound having an epoxy equivalent of 500-1500,
(E) 20 to 125 parts by weight of an inorganic filler,
(F) 0.1-10 parts by weight of ionomer,
(G) A flame retardant polyester resin composition comprising 0.5 to 10 parts by weight of a crystallization accelerator.

  ADVANTAGE OF THE INVENTION According to this invention, the flame-retardant polyester resin composition which has high flame retardance and heat resistance, and can be shape | molded with a low temperature metal mold | die can be provided. The molded product obtained from the flame-retardant polyester resin composition of the present invention is particularly useful for electric / electronic parts and greatly contributes to the industrial world.

Hereinafter, the present invention will be described in detail.
[(A) Polyethylene terephthalate]
(A) Polyethylene terephthalate used in the present invention is a polyester resin mainly composed of terephthalic acid or its ester-forming derivative as a dicarboxylic acid component, and ethylene glycol or its ester-forming derivative as a diol component. is there.

  The (A) polyethylene terephthalate may be partially substituted with a copolymer component. Examples of such copolymer components include phthalic acid derivatives such as isophthalic acid, phthalic acid, methyl terephthalic acid, and methyl isophthalic acid; 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid Naphthalenedicarboxylic acid and its derivatives such as acids; diphenyldicarboxylic acid and its derivatives such as 4,4′-diphenyldicarboxylic acid and 3,4′-diphenyldicarboxylic acid; 4,4′-diphenoxymethanedicarboxylic acid and 4,4 Aromatic dicarboxylic acids such as' -diphenoxyethanedicarboxylic acid; aliphatic or alicyclic carboxylic acids such as succinic acid, adipic acid, sebacic acid, azelaic acid, decanedicarboxylic acid, cyclohexanedicarboxylic acid and derivatives thereof; propylene glycol; Tetramethylene glycol, hexame Aliphatic diols such as lenglycol, neopentyl glycol, diethylene glycol; alicyclic diols such as 1,4-cyclohexanedimethanol; dihydroxybenzenes such as hydroquinone and resorcin and derivatives thereof; 2,2-bis (4-hydroxyphenyl) Bisphenol compounds such as propane and 2,2-bis (4-hydroxyphenyl) sulfone; aromatic diols such as ether diols obtained from bisphenol compounds and glycols such as ethylene glycol; ε-oxycaproic acid, hydroxybenzoic acid, hydroxy And oxydicarboxylic acids such as ethoxybenzoic acid.

  Further, polyalkylene glycols such as polyethylene glycol and polytetramethylene glycol may be copolymerized.

  The copolymerization ratio of these components is preferably 40 mol% or less, more preferably 10 mol% or less.

  In the present invention, (A) polyethylene terephthalate may be used in combination of two or more.

  In addition, (A) polyethylene terephthalate having an intrinsic viscosity of 0.5 or more can be used when measured at 35 ° C. using o-chlorophenol, preferably 0.6 to 1.2.

(A) Polyethylene terephthalate can be produced by an ordinary polyester production method, for example, melt polycondensation or a method combining this with solid phase polycondensation. Polyethylene terephthalate is prepared by, for example, reacting terephthalic acid or an ester-forming derivative thereof (for example, a lower alkyl ester such as dimethyl ester or monomethyl ester) with ethylene glycol or an ester-forming derivative thereof by heating in the presence of a transesterification catalyst. It can be produced by obtaining a glycol ester of an acid and subjecting it to a predetermined polymerization degree in the presence of a polymerization catalyst.
[(B) Brominated aromatic compounds]
(B) As a brominated aromatic compound, what is generally used as a flame retardant can be used. Specifically, a brominated bisphenol A type epoxy resin and / or a modified product in which part or all of the terminal glycidyl group is blocked, brominated polyacrylate, brominated polystyrene, brominated polyphenylene ether, brominated bisphenol A are used as raw materials. Polycarbonate oligomers, brominated biphenyl ethers, brominated diphthalimide compounds and the like produced as Among these, brominated polystyrene and brominated polyacrylate are preferable, and brominated polystyrene is particularly preferable because there is little decrease in electrical insulation due to blending with polyethylene terephthalate.

(B) The compounding quantity of a bromine-type aromatic compound is 3-30 weight part with respect to 100 weight part of (A) polyethylene terephthalate, Preferably it is 15-25 weight part. When the blending amount is less than 3 parts by weight, the flame retarding effect of the composition is small, and when it exceeds 30 parts by weight, the fluidity and mechanical properties of the composition are deteriorated.
[(C) Antimony trioxide compound]
(C) The antimony trioxide compound functions to enhance the flame retardancy of the composition by a synergistic effect with the (B) bromine-based aromatic compound. (C) As the antimony trioxide compound, those having a particle size of 0.02 to 10 μm are particularly preferably used.

(C) The compounding quantity of an antimony trioxide compound is 1-20 weight part with respect to 100 weight part of (A) polyethylene terephthalate, Preferably it is 7.5-12.5 weight part. If the blending amount is less than 1 part by weight, the flame retardant effect of the composition due to the synergistic effect with (B) brominated aromatic compound is small, and if it exceeds 20 parts by weight, the fluidity and mechanical properties of the composition are lowered. To do.
[(D) Bisphenol A epoxy compound]
As the (D) bisphenol A type epoxy compound used in the present invention, a monofunctional, difunctional, trifunctional or polyfunctional epoxy compound is used. Among them, monofunctional and bifunctional bisphenol A types are used. Epoxy compounds are preferred. The (D) component bisphenol A type epoxy compound must have an epoxy equivalent of 500-1500. When the epoxy equivalent is less than 500, the heat resistance is poor, and when it exceeds 1500, the fluidity tends to be lowered. Examples of such component (D) include Epicoat 1004K (manufactured by Yuka Shell Epoxy Co., Ltd.).

The blending amount of the (D) bisphenol A type epoxy compound is 0.1 to 3 parts by weight, preferably 0.3 to 1.5 parts by weight, based on 100 parts by weight of (A) polyethylene terephthalate. If the blending amount is less than 0.1 parts by weight, the effect of improving hydrolyzability is small, and if it exceeds 3 parts by weight, the mechanical properties of the molded product obtained from the composition are insufficient.
[(E) Inorganic filler]
(E) Examples of inorganic fillers include fibrous fillers such as glass fiber, graphite fiber, silica fiber, alumina fiber, boron fiber, feldspar, potassium titanate whisker, potassium borate whisker, etc .; plates such as mica and glass flakes And particulate fillers such as silica, glass beads, glass bubbles, kaolin, wollastonite, calcium silicate, calcium carbonate, and the like. These may be used alone or in combination of two or more. Glass fibers are particularly preferably used because of the mechanical strength, heat resistance and dimensional stability of the composition.

  (E) The inorganic filler may be surface-treated if necessary. Examples of compounds used for the surface treatment include functional compounds such as epoxy compounds, isocyanate compounds, silane compounds, and titanate compounds. These compounds may be used after being surface-treated on an inorganic filler, or may be added during material preparation.

(E) The compounding quantity of an inorganic filler is 20-125 weight part with respect to 100 weight part of (A) polyethylene terephthalate, Preferably it is 50-100 weight part. And it is preferable to mix | blend in the range of 15 to 50 weight% of the composition total weight. By mix | blending in this range, a moldability is favorable and the composition which is excellent also in mechanical strength can be obtained.
[(F) Ionomer]
The ionomer (F) used in the present invention is a polymer ionomer having a metal ion having an interaction with the main chain or side chain of the polymer compound, for example, polyacrylic acid ionomer, ethylene / unsaturated carboxylic acid copolymer. Combined ionomers can be used. In particular, an ionomer of an ethylene / unsaturated carboxylic acid copolymer is preferably used.

  The polymer compound constituting the ionomer of the ethylene / unsaturated carboxylic acid copolymer is preferably a random copolymer of ethylene and an unsaturated carboxylic acid, an ethylene / unsaturated carboxylic acid and another copolymerizable monomer. And a random copolymer.

  The polymerization rate of the unsaturated carboxylic acid in the random copolymer is usually 5 to 30% by weight, preferably 10 to 25% by weight, and the polymerization rate of other copolymerizable monomers is usually 0 to 40% by weight. %, Preferably 0 to 25% by weight, more preferably 0 to 10% by weight.

  Examples of the unsaturated carboxylic acid include acrylic acid, methacrylic acid, monomethyl maleate, monoethyl maleate, maleic anhydride, itaconic acid, etc. Among them, acrylic acid and methacrylic acid are preferable.

  Other copolymerizable monomers include unsaturated carboxylic acids such as methyl acrylate, ethyl acrylate, isobutyl acrylate, nbutyl acrylate, isooctyl acrylate, methyl methacrylate, isobutyl methacrylate, and diethyl maleate. Examples include esters, vinyl acetate, vinyl esters such as vinyl propionate, and carbon monoxide. Among them, methyl acrylate, ethyl acrylate, isobutyl acrylate, nbutyl acrylate, isooctyl acrylate, methacrylic acid Methyl and isobutyl methacrylate are preferred.

  (F) The metal ions constituting the ionomer are, for example, zinc, magnesium, calcium, barium, sodium, potassium, lithium, lead, tin, aluminum, copper, cobalt, nickel, and zinc and sodium are particularly preferable.

  (F) The ionomer polymer compound is neutralized by these metal ions, but the degree of neutralization of the ionomer by the metal ions is usually 5 to 100%, preferably 20 to 80%.

  (F) The ionomer preferably has a melt flow rate of 0.01 to 20 g / 10 min at 190 ° C. and 2160 g weight, particularly preferably 0.1 to 10 g / 10 min.

The compounding amount of (F) ionomer is 0.1 to 10 parts by weight, preferably 0.3 to 5 parts by weight with respect to 100 parts by weight of (A) polyethylene terephthalate. When the blending amount is less than 0.1 parts by weight or more than 10 parts by weight, both flame retardancy and heat resistance are inferior.
[(G) Crystallization accelerator]
In the present invention, the composition contains (G) a crystallization accelerator. (G) As a crystallization accelerator, an inorganic compound, organic carboxylic acid metal salt, polyalkyne glycol, polycaprolactone, kaolin, etc. can be illustrated, and 1 type, or 2 or more types can be used. Polycaprolactone is particularly preferable.

(G) The compounding quantity of a crystallization accelerator is 0.5-10 weight part with respect to 100 weight part of (A) polyethylene terephthalate, Preferably it is 5-10 weight part. When the blending amount is less than 0.5 parts by weight, a molded product with high crystallinity cannot be obtained, and deformation due to crystallization may occur when used under high temperature conditions. On the other hand, if it exceeds 10 parts by weight, the mechanical properties, particularly the impact properties, of the molded product obtained from the composition will be insufficient.
[Other additives]
In the composition of the present invention, flame retardants other than the above components (B) and (C), flame retardant aids, pigments and other additives are added in the expression amount as long as the intended effect of the present invention is not impaired. May be.

  That is, as a flame retardant, for example, expandable graphite, metal hydroxide, triazine compound, silicone compound, phosphorus compound, etc., as a flame retardant aid, for example, boron oxide, zinc borate, zinc stannate, oxidation Metal compounds such as iron can be blended.

  In order to further enhance the effect of the flame retardant, a compound that suppresses dripping of molten particles during combustion may be blended. Examples of the compound that exhibits such an effect include polytetrafluoroethylene and fumed silica created by emulsion polymerization.

  In addition, for the purpose of improving heat resistance, antioxidants or heat stabilizers such as hindered phenol compounds, aromatic amine compounds, organic phosphorus compounds, sulfur compounds may be blended, and other stabilizers, colorants, lubricants. UV absorbers, antistatic agents, and the like may be blended.

In addition, the composition of the present invention may contain, in small proportions, any other thermoplastic resin such as aliphatic polyester, polyamide, polyphenylene sulfide, polyphenylene ether, phenoxy resin, polyethylene and its copolymers, polypropylene and its copolymers. Polymers, polystyrene and copolymers thereof, acrylic resins and acrylic copolymers, polyamide elastomers, polyester elastomers, thermoplastic phenol resins, thermosetting resins such as phenol resins, melamine resins, unsaturated polyester resins, silicone resins Etc. may be blended.
[Production method]
In the flame-retardant resin composition of the present invention, it is preferable that the compounding components are uniformly dispersed. The ingredients can be blended using known methods. For example, all or a part of the compounding components are supplied to a heated single-screw or twin-screw extruder in a batch or divided, homogenized by melt kneading, and then the molten resin is extruded into a wire shape. The pellets of the flame retardant resin composition used for molding can be formed by cooling and solidifying, then cutting into a desired length and granulating.

  You may manufacture a flame-retardant resin composition by the method using other mixers, such as a blender, a kneader, and a roll. Moreover, you may take the method of using these in combination or adding a compounding ingredient one by one by repeating several times.

  The flame-retardant resin composition for molding produced in this way can be formed into a molded product by being subjected to shaping with a molding machine such as an injection molding machine while usually kept in a sufficiently dried state. Alternatively, the blended components may be dry blended, directly charged into a molding machine hopper, and melt-kneaded in the molding machine to obtain a flame retardant resin composition.

  The shaping can be performed using an injection molding machine or the like. The injection molding machine may be a normal one, but is preferably molded at a cylinder temperature of 260 to 300 ° C., further 260 to 280 ° C., a mold temperature of 80 to 130 ° C., and further 100 to 130 ° C. The cooling time varies depending on the shape and size of the molded product, but is usually preferably 10 to 60 seconds.

  By using the flame retardant polyester resin composition of the present invention, the heat resistance is good, and when classified according to the UL94 standard vertical combustion test evaluation method, the flame retardancy using a 0.8 mm thick test piece is A molded product that is V-0, in particular, a thin molded product can be obtained.

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited thereto. In addition, the measuring method of the characteristic evaluation shown in the following examples is as follows.
(Combustion quality)
The flammability was evaluated using a test piece having a thickness of 0.8 mm by the UL94 standard vertical combustion test method. Flammability was classified according to the evaluation method described in UL94.
(MFR)
Measurement was performed at 280 ° C. in accordance with ISO1133.
(Heat-resistant)
In accordance with ISO527-1, the tensile strength was measured, and the tensile strength of the test piece after being left at 170 ° C. for 1500 hours was measured, and the strength retention rate was used as an index of heat resistance.
Examples 1-3, Comparative Examples 1-4
Each component shown in Table 1 is uniformly mixed with a tumbler at the ratio shown in Table 1, and using a twin screw extruder with a vent with a screw diameter of 44 mm, while pulling a vacuum, a cylinder temperature of 270 ° C., a screw rotation speed of 120 rpm, The mixture was melt-kneaded at a discharge rate of 15 kg / hr, and the thread discharged from the die was cooled and cut to obtain resin composition pellets.

  Next, using this pellet, a molded product for measuring each characteristic is molded on an injection molding machine under the conditions of a cylinder temperature of 280 ° C, a mold temperature of 100 ° C, an injection pressure of 60 MPa, a cooling time of 30 seconds, and a total molding cycle of 60 seconds. And evaluated. The results are shown in Table 1.

In addition, each component used for the Example and the comparative example is as showing below.
(A) Component ・ Polyethylene terephthalate (Polyethylene terephthalate (PET) manufactured by Teijin Limited)
(B) Ingredients Brominated polystyrene (Pyrocheck 68PB: manufactured by Ferro Corporation)
(C) Component ・ (C-1) Antimony trioxide (PATOX-M: NIPPON SEIKO CO., LTD.)
・ (C-2) Sodium antimonate (SAA: manufactured by Nippon Seiko Co., Ltd.)
(D) Component ・ (D-1) Bisphenol A type epoxy (Epicoat 1004K: manufactured by Yuka Shell Epoxy Co., Ltd., average molecular weight 1600, epoxy equivalent 930)
・ (D-2) Bisphenol A type epoxy (Epicoat 828: Yuka Shell Epoxy Co., Ltd., average molecular weight 800, epoxy equivalent 190)
・ (D-3) Bisphenol A type epoxy (Epicoat 1010: manufactured by Yuka Shell Epoxy Co., Ltd., average molecular weight 5500, epoxy equivalent 4000)
(E) Component / (E-1) Glass fiber (ECS03T187: manufactured by NEC Glass)
・ (E-2) Mica (Suzolite Mica 180S: Kuraray Co., Ltd.)
(F) Ionomer of component / ethylene / methacrylic acid copolymer (Himiran 1707: manufactured by Mitsui DuPont Co., Ltd., MFR in ASTM D-1238 is 0.9)
(G) Component / Polycaprolactone (Placcel BCL2: manufactured by Daicel Chemical Industries, Ltd.)

Claims (2)

(A) For 100 parts by weight of polyethylene terephthalate,
(B) 3 to 30 parts by weight of a brominated aromatic compound,
(C) 1-20 parts by weight of an antimony trioxide compound,
(D) 0.1-3 parts by weight of a bisphenol A type epoxy compound having an epoxy equivalent of 500-1500,
(E) 20 to 125 parts by weight of an inorganic filler,
(F) 0.1-10 parts by weight of ionomer,
(G) A flame retardant polyester resin composition comprising 0.5 to 10 parts by weight of a crystallization accelerator.   (G) The flame retardant polyester resin composition according to claim 1, wherein the crystallization accelerator is polycaprolactone.