JP2000044777A - Flame-retardant polyester resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a flame-retardant polyester resin compsn. which can be molded into thin-walled molded articles and is excellent in impact resistance by compounding polybutylene terephthalate with an inorg. filler, an ethylene-α- olefin copolymer, a specific bromine compd., and an antimony compd. SOLUTION: At least one compd. selected from among a brominated polyacrylate of formula I, an adduct of a brominated bisphenol A diglycidyl ether with a brominated bisphenol A of formula II, an ethylene-bis-brominated imide of formula III, and a brominated polystyrene of formula IV is used as the bromine compd. In formula I, R is H or methyl; (n) is an integer of 10 or higher; and (m) is an integer of 1-5. In formula II, (n) is an integer of 10 or higher; and (m) is an integer of 1-5. In formula III, (n) is an integer of 1-5. In formula IV, R, (n) and (m) are each the same as in formula I. The ethylene-α- olefin copolymer is pref. the one prepd. by the graft polymn. of an acid deriv. of an α,β-unsatd. carboxylic acid.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a flame-retardant polyester resin composition, and more particularly to a flame-retardant polyester resin composition having excellent impact resistance.

[0002]

2. Description of the Related Art Polybutylene terephthalate (hereinafter referred to as PBT)
(May be abbreviated as ``) '' is a thermoplastic material that has excellent moldability, has various excellent properties including solvent resistance, and has good physical and mechanical properties by melt molding and injection molding. It is used for various purposes. Typical applications include electrical and electronic component applications, electrical appliance housings, and automotive applications. Among these applications, materials used in electric and electronic applications are required to have flame retardancy. On the other hand, with the miniaturization of products, the demand for materials is also shifting to higher strength and higher impact. In view of such demands, a method of improving the impact resistance by a method such as adding a flame retardant of a brominated polycarbonate and an acrylic rubber or an olefin rubber has conventionally been used.

[0003]

However, the conventional method cannot meet the recent demand for a thinner molded product, and further improvement is desired.

[0004] It is an object of the present invention to provide a flame-retardant thermoplastic polyester resin composition having excellent impact resistance that can cope with a reduction in the thickness of a molded product.

[0005]

Means for Solving the Problems As a result of diligent studies, the present inventors have found that when flame retardation and high impact of polybutylene terephthalate are to be achieved, an ethylene-α-olefin copolymer and a specific bromine compound are combined and compounded. As a result, the present inventors have found that flame retardancy and impact resistance can be improved to a very high degree.

That is, the present invention relates to a polybutylene terephthalate (A), an inorganic filler (B), an ethylene-α-olefin copolymer (C), and a compound represented by formulas (I) to (IV). One or more selected bromine compounds (D)

[0007]

Embedded image

And a flame-retardant polyester resin composition comprising an antimony compound (E).

The polybutylene terephthalate (A) used in the present invention contains terephthalic acid as a main acid component,
Polyester containing 1,4-butanediol as the main glycol component. Here, the main component is at least 80 mol%, preferably 9 mol%, based on all acid components or all glycol components.
A component that accounts for 0 mol% or more.

The acid component which can be copolymerized is, for example, an aromatic dicarboxylic acid other than terephthalic acid, for example, isophthalic acid,
Naphthalene dicarboxylic acid, diphenyl dicarboxylic acid, diphenyl ether dicarboxylic acid, diphenoxyethane dicarboxylic acid, diphenyl ketone dicarboxylic acid; aliphatic dicarboxylic acids such as succinic acid, adipic acid, sebacic acid and the like; alicyclic dicarboxylic acids such as cyclohexane dicarboxylic acid, And tetralin dicarboxylic acid.

The glycol components which can be copolymerized include, for example, ethylene glycol, hexamethylene glycol, neopentyl glycol, cyclohexane dimethanol, tricyclodecane dimethylol, shikirenylene glycol, bisphenol A, bisphenol B, bishydroxyethoxybisphenol A. is there.

Further, a polyfunctional compound such as glycerin, trimethylolpropane, pentaerythritol, trimellitic acid or pyromellitic acid is copolymerized in a range where the polyester does not substantially lose the molding performance, for example, in a range of 3 mol% or less. May be.

Examples of other copolymerizable components that can be used in obtaining polybutylene terephthalate include oxyacids such as p-hydroxybenzoic acid and p-hydroxyethoxybenzoic acid.

The inorganic filler (B) used in the present invention includes, for example, fibrous fillers such as glass fiber, graphite fiber, silica fiber, alumina fiber, boron fiber, feldspar, potassium titanate whisker and potassium borate whisker. A plate-like filler such as mica and glass flakes; and silica, glass beads, glass bubbles, kaolin,
Granular fillers such as wollastonite, calcium silicate and calcium carbonate can be exemplified, and these can be used alone or in combination of two or more. Glass fibers are particularly preferred in view of the mechanical strength, heat resistance and dimensional stability of the material.

These inorganic fillers may be surface-treated or non-surface-treated.
Examples of compounds used for surface treatment include functional compounds such as epoxy compounds, isocyanate compounds, silane compounds, and titanate compounds. These compounds may be used after surface-treating the inorganic filler in advance, or may be added when adjusting the material.

The amount of the inorganic filler (B) is preferably 1 to 1 based on 100 parts by weight of the polybutylene terephthalate (A).
25 parts by weight, preferably 15 to 45 parts by weight of the total resin composition
% Range. Within this range, a molded product having good moldability and excellent mechanical strength can be obtained.

As the ethylene-α-olefin copolymer (C) used in the present invention, an ethylene polymer or a copolymer of ethylene and an α-olefin having 3 or more carbon atoms (hereinafter, both are collectively referred to as “ A modified ethylene polymer obtained by graft-polymerizing an α, β-unsaturated carboxylic acid or an acid derivative thereof onto a modified ethylene polymer) is used.

The unmodified ethylene polymer is preferably a copolymer type, and the α-olefin as a copolymer component is propylene, butene-1, hexene-1, decene-1, or the like.
4-methylbutene-1, 4-methylpentene-1 and the like. Of these, propylene and butene-1 are particularly preferred.

The α, β-unsaturated carboxylic acid or its acid derivative (hereinafter collectively simply referred to as α, β-unsaturated carboxylic acid) to be graft-polymerized to an unmodified ethylene polymer includes acrylic acid and methacrylic acid. Examples thereof include acids, ethacrylic acid, maleic acid, fumaric acid, esters of the above acids, glycidyl esters, acid anhydrides and imides. Of these, glycidyl esters, maleic anhydride and maleic imide are particularly preferred.

When the amount of the α, β-unsaturated carboxylic acid to be graft-polymerized to the unmodified ethylene polymer is too small,
It is difficult to achieve the initial purpose, and when it is too large, there is a problem that the obtained thermoplastic polyester resin composition is colored yellow or red and only a molded article having a poor appearance can be obtained. Therefore, the amount to be graft-polymerized is preferably 0.1 to 100% by weight of the unmodified ethylene polymer.
-1% by weight.

The term "graft polymerization" as used herein means that a part or all of an unmodified ethylene polymer is chemically bonded to a monomer or polymer of an α, β-unsaturated carboxylic acid or a derivative thereof.

Such a modified ethylene polymer can be easily produced by adding an α, β-unsaturated carboxylic acid to an unmodified ethylene polymer according to a conventional method, and usually kneading the mixture at 150 to 300 ° C.

For melt kneading, a screw type extruder is often used. Of course, in order to efficiently cause graft polymerization, an organic peroxide such as α, α * -bis-t-butylperoxy-p-diisopropylbenzene is added in an amount of 0.001 to 100% by weight based on the unmodified ethylene polymer. 0.05% by weight
May be used.

As the unmodified ethylene polymer which is a raw material of the modified ethylene polymer, for example, a vanadium compound such as vanadium oxytrichloride or vanadium tetrachloride and an organoaluminum compound in a low-density polyethylene or Ziegler-Natta catalyst are used. Use 50 mol% or more, preferably 50
Products obtained by copolymerizing 〜95 mol% of ethylene with 50 mol% or less, preferably 20-5 mol%, of α-olefin are exemplified. As particularly suitable as such an unmodified ethylene polymer, a series of polymers marketed by Mitsui Petrochemical Industry Co., Ltd. under the trademark Tuffmer, for example, Tuffmer A-4085, Tuffmer A-4090, Tuffmer A-20090 And Tuffmer P series (ethylene-propylene copolymer) such as Tuffmer P-0180, Tuffmer P-0280, Tuffmer P-0480, and Tuffmer P-0680.

The amount of the ethylene-α-olefin copolymer (C) is 5 to 20 parts by weight based on 100 parts by weight of polybutylene terephthalate (A), preferably 5 to 10% by weight based on the total composition. Is the amount Ethylene-α-olefin copolymer
When the amount of (C) is less than 5 parts by weight, there is no effect of improving thermal shock resistance, and when it exceeds 20 parts by weight, the rigidity is remarkably reduced, which causes a problem in use as engineering plastics.

As the bromine compound of the component (D) used in the present invention, at least one compound selected from the group consisting of compounds represented by the following general formulas (I) to (IV) is used.

[0027]

Embedded image

Of these, compounds having a bromine content of at least 65% are preferred, and compounds having a bromine content of at least 70% are particularly preferred.

The thermoplastic polyester resin composition of the present invention may contain various additives such as a stabilizer, an ultraviolet absorber, an antistatic agent, a pigment, and a release agent in any ratio.

[0030]

The present invention will be described below in more detail with reference to Examples and Comparative Examples. The evaluation methods in the examples are as follows. In the tables, the units of the components constituting the composition are parts by weight unless otherwise specified.

[Evaluation method] [Impact resistance (impact strength)] Using an injection molding machine having a cylinder capacity of 147 cm ³ and a mold clamping force of 80 t, conditions of a cylinder temperature of 260 ° C., a mold temperature of 80 ° C., and a total molding cycle of 45 seconds. After forming an impact test specimen specified in ASTM-D256 by, a notch processing was performed by machining so that the remaining thickness of the test specimen became 0.4 inch, to obtain a test specimen. The physical properties were evaluated for impact resistance according to ASTM-D256.

[Flame-retardant (combustible)] Cylinder capacity 147c
m ³ , cylinder temperature 260 using an injection molding machine with a mold clamping force of 80t
Unde under the conditions of 80 ° C, mold temperature 80 ° C, and total molding cycle 45 seconds.
A 0.8 mm thick test piece specified by UL94, a vertical flammability standard of rwriters Laboratories, was molded. Flammability is UL94
It was evaluated according to the vertical combustion test.

[Production of modified EPR] α, α-bis-t-butylperoxy- dissolved in 100 parts by weight of unmodified ethylene-propylene copolymer (Tuffmer P0680) manufactured by Mitsui Chemicals, Inc. and a small amount of acetone After blending 0.025 parts by weight of p-diisopropylbenzene and 0.5 parts by weight of maleic anhydride in a Henschel mixer, the mixture is extruded at a cylinder temperature of 230 ° C. using a twin-screw extruder having a screw diameter of 44 mm to form a pellet, and the modified ethylene polymer (hereinafter, denatured) EPR).

[Examples 1 to 4] Polybutylene terephthalate (hereinafter sometimes referred to as PBT) having an intrinsic viscosity of 0.70 dl / g (in orthochlorophenol at 35 ° C.) and glass fiber are shown in Table 1. Bromine compounds, modified EPR mentioned above as an impact modifier, and Nippon Concentrate as antimony trioxide.
ATOX-S manufactured by Polytetrafluoroethylene resin as a dripping inhibitor was uniformly premixed as shown in Table 2 (in parts by weight), and using a twin-screw extruder with a screw diameter of 44 mm, barrel temperature was 250 ° C. , Discharge rate 50kg / h, screw rotation speed 120r.pm
And melt-kneaded into pellets. 13 pellets obtained
After preliminary drying at 0 ° C. × 5 hours, injection molding was performed, and physical properties were evaluated by the above-described methods. Table 2 shows the results.

Comparative Example 1 Evaluation was made in the same manner as in Example 1 except that no impact modifier was added. Table 2 shows the results.

Comparative Example 2 Evaluation was made in the same manner as in Examples 1 to 4, except that the brominated compound was changed to a brominated polycarbonate oligomer. Table 2 shows the results.

Comparative Example 3 Ethylene as impact modifier
Evaluation was performed in the same manner as in Example 1 except that NUC894 manufactured by Nippon Unicar was used as the ethyl acrylate resin. Table 2 shows the results.

[0038]

[Table 1]

[0039]

[Table 2]

[0040]

The flame-retardant polyester obtained by the present invention is a flame-retardant polyester resin composition which has remarkably improved flame retardancy and impact resistance, and can be suitably used for small-sized thin molded products.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08L 25/18 C08L 25/18 33/16 33/16 51/06 51/06 F-term (Reference) 4J002 BB212 BC113 BG083 BN052 CF071 CF081 DA026 DE146 DE186 DE236 DJ006 DJ016 DJ056 DK006 DL006 EU027 FA046 FA066 FD016 FD133 FD137 GN00 GQ00

Claims (2)

[Claims] 1. Polybutylene terephthalate (A), inorganic filler (B), ethylene-α-olefin copolymer (C),
One or more bromine compounds (D) selected from the group consisting of compounds represented by (I) to (IV) And a flame-retardant polyester resin composition comprising an antimony compound (E). 2. An ethylene-α-olefin copolymer (C)
2. The flame-retardant polyester resin composition according to claim 1, wherein is a ethylene-α-olefin copolymer obtained by graft-polymerizing an acid derivative of an α-β unsaturated carboxylic acid.