JPS61188446A - Flame-retardant polyethylene terephthalate resin composition - Google Patents

Abstract

PURPOSE:To provide the title compsn. which is highly crystalline, has excellent moldability and gives moldings having excellent dimensional stability, by blending a polyethylene terephthalate resin, glass fiber, a nucleating agent, a specified compd., a flame retarder and antimony oxide. CONSTITUTION:30-85wt% polyethylene terephthalate resin having an intrinsic viscosity of 0.4-1.4, 5-60wt% glass fiber having a length of 0.4-6mm, 0.03-20wt% nucleating agent, 0.1-10wt% at least one member selected from among monoepoxy compds. of the formula (wherein R1 is a 2-6C or higher hydrocarbon group; R2 is a C2-6 hydrocarbon group; n is o or at least 1), 2-20wt% high-molecular brominated flame retarder contg. a brominated arom. ring on its high-molecular side chain, 0.5-10wt% antimony oxide as flame retardant aid and optionally, additives such as filler, light or thermal stabilizer, dye, pigment, etc., are blended together.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a flame-retardant polyethylene terephthalate resin composition, and more particularly to a highly crystalline glass fiber reinforced flame-retardant polyethylene terephthalate resin composition. .

[Conventional technology]

It is known that glass fiber reinforced polyethylene terephthalate resins have excellent mechanical properties, chemical resistance, and the like.

Therefore, it is used in electrical and electronic parts, including parts for heating appliances. In particular, flame-retardant glass fiber-reinforced polyethylene terephthalate resin is suitable for electrical and electronic parts.

However, since ordinary glass fiber-reinforced polyethylene terephthalate resin has a slow crystallization rate, a molded article with complete crystallization cannot be obtained unless molding is performed using a high-temperature mold. Therefore, products molded using low-temperature molds have insufficient crystallization, resulting in poor moldability of the resulting resin.
In addition, shrinkage and warpage due to post-heating increase.

In other words, in fields such as electrical and electronic parts, where there are many light, thin, and short products, molding with low-temperature molds and high cycles is required in order to shorten the molding cycle, and the dimensional stability of the resulting molded products is required. Gender is strictly required. Therefore, in this field, there is a large difference in the amount used since high cycle performance and dimensional stability are significantly inferior to polybutylene terephthalate resin, which is the same polyester resin, and improvement in crystallinity is desired.

[Problem that the invention seeks to solve]

The present invention solves the above-mentioned drawbacks and solves the problem of high crystallinity, making it possible to produce molded products with a high heat distortion temperature and excellent moldability, mold releasability, and dimensional stability without reducing mechanical strength. The purpose of the present invention is to provide a flammable polyethylene terephthalate resin composition.

[Means for solving problems]

As a result of intensive studies to eliminate the above-mentioned drawbacks, the present inventor has developed a glass fiber-reinforced polyethylene terephthalate resin composition using a polymeric flame retardant with a specific structure and a specific monoepoxy compound as a crystallization accelerator. It has been discovered that the composition obtained when a specific amount is blended can undergo sufficient crystallization even at a mold temperature of 100° C. or less and has excellent moldability, and has completed the present invention.

That is, the flame-retardant polyethylene terephthalate resin composition of the present invention contains: 30% by weight of polyethylene terephthalate resin
85% by weight (Bl Glass fiber 5% to 60% by weight (
C1 nucleating agent 0.03% to 20% by weight (Dl
0.1% to 10% by weight of at least one selected from the monoepoxy compounds represented by the general formula (I), where R2: Hydrocarbon having 6 or more carbon atoms R7: Hydrocarbon having 2 to 6 carbon atoms n: An integer of 0 or 1 or more fEl A polymer-type brominated flame retardant having a brominated aromatic ring in the side chain of the polymer 2% to 20% by weight (n Comprising 0.5% to 10% by weight of antimony oxide) , and tA) to (Fl), the total amount of each component is 100% by weight.

The polybutylene terephthalate resin used in the present invention refers to a homopolymer of linear polyethylene terephthalate having ethylene terephthalate as a constituent unit; a copolymer of the unit component and other copolymerizable components; or a homopolymer thereof. and a copolymer, but the invention is not particularly limited to these. As the components that can be copolymerized here, conventionally known acid components and glycol components can be used, and specifically, for example, heptalic acid, isophthalic acid, adipic acid, sebacic acid, naphthalene-1
, 4-Also L<bar 2.6-Silyrboxylic acid, diphenyl ether-4,4'-dicarboxylic acid and other acid components; propylene glycol, butylene glycol, neopentyl glycol, cyclohexane dimetatool, 2.2- Glycol components such as bis(4-hydroxyphenyl)propane; p-oxybenzoic acid, p-hydroxybenzoic acid, p
-oxyacids such as hydroxyethoxybenzoic acid. The resin can be obtained by a normal polymerization method such as polycondensation of terephthalic acid and ethylene glycol by transesterification or direct esterification, but in this case, the intrinsic viscosity [η] of the resin is set to 0. It is preferable to set it in the range of 4 to 1.4.

Here, as a method for obtaining a resin having a high intrinsic viscosity, it is also possible to obtain a resin having a relatively low intrinsic viscosity by a conventional solid phase polymerization method. Furthermore, the intrinsic viscosity mentioned here is
This is a value determined from the viscosity of a solution measured at 25° C. in a solvent of phenol/tetrachloroethane=50150 (weight ratio). Such polyethylene terephthalate resin is blended in an amount of 30 to 85% by weight in the total resin composition. 3
If it is less than 0% by weight, the flow processability will decrease, and if it is less than 85% by weight,
If it exceeds 20%, the moldability in a low-temperature mold will decrease. As the glass fiber used in the present invention, any type of glass fiber such as a roving type or a chopped strand type can be used, but a chopped strand type is preferable from the viewpoint of productivity. In addition, considering workability during mixing of the resin composition of the present invention, wear of the molding machine, and cutting during the molding process, glass fibers having a length of approximately 0.4 to 6 mm may be used during mixing to form the final molded product. Its length in about 0.2~
It is preferable to set it in the range of 2 occlusions. As such glass fibers, commercially available products that have been subjected to various treatments can be used as they are, and the mixing method is not particularly limited.

Incidentally, the glass fiber is blended in a range of 5 to 60% by weight in the total resin composition.

When the blending amount exceeds 60% by weight, fluid processability decreases,
If it is less than 5% by weight, the reinforcing effect of the glass fibers will be insufficient.

The nucleating agent (C1) used in the present invention is a nucleating agent of polyethylene terephthalate, such as sodium stearate, calcium stearate, sodium benzoate, calcium benzoate, sodium terephthalate, lithium terephthalate, etc. Metal salts of Group I or Group A of carboxylic acids, monovalent or divalent metal salts of ionic copolymers consisting of α-olefins and α,β-unsaturated carboxylic acid salts, neutral clays kind of Merck,
Examples include oxides, sulfates, and silicates of group metals in the periodic table, such as zinc oxide, magnesium oxide, calcium silicate, magnesium silicate, calcium sulfate, and barium sulfate.

These nucleating agents may be used alone or in combination, and may be incorporated in a weight range of 0.5 to 20 percent by weight based on the total resin composition. That is, even when a metal salt of an organic carboxylic acid with a relatively high nucleating effect is used, if the amount is less than 0.03% by weight, the excellent heat resistance and appearance improvement effect will be insufficient, and on the contrary, the strength will be relatively low. Even when using Merck with a small amount of 20%
Weight t% or less is sufficient.

The monoepoxy compound constituting the present invention has the general formula (I)
Specifically, 2-ethylhexyl glycidyl ether, lauryl glycidyl ether,
Tridecyl glycidyl ether, stearyl glycidyl ether, polyethylene glycol monophenyl monocrycidyl ether, polypropylene glycol monophenyl monoglycidyl ether, polyethylene glycol monolauryl monoglycidyl ether-7-#, HoIJ ethylene glycol monostearyl monoglycidyl ether, etc. In addition, glycidyl ethers of alcohols having long-chain alkyl groups, monocricidyl ethers containing polyoxyalkylene chains, and polyethylene terephthalate resins are preferred because they have a small decrease in molecular weight. The monoepoxy compounds represented by formula (I) are used alone or in combination, and are blended in an amount of 0.1 to 10iif% in the total resin composition.

If the amount is 0.1% by weight, the crystallization promoting effect will be insufficient, and if it exceeds 10% by weight, the mechanical strength of the resulting molded product will decrease.

Furthermore, the polymer-type brominated flame retardant (El is a polymer having a brominated aromatic ring □ in the side chain of the polymer, specifically, polybentab d-muhensyl acrylate, polypentab rombenzyl methacrylate, polytetrabrom xylylene bis acrylate, polytetra brom xylylene bis methacrylate, poly(2,4
, 6) repromo) styrene, poly(2,4,5toIJ)
7" lomo) styrene, etc. The polymeric brominated flame retardant is blended in an amount of 2 to 20% by weight in the total resin composition. If it is less than 2% by weight, the flame retardant effect will be reduced. It is hardly expected, and the crystallization promoting effect as a combined effect with the monoepoxy compound (DJ) does not appear significantly. Also, if it exceeds 20% by weight, the mechanical strength of the molded product obtained decreases.

Antimony oxide tFl constituting the present invention is a component (
It acts as a flame retardant auxiliary agent for El flame retardants and has a temperature control effect, specifically antimony trioxide and antimony pentoxide. In order to exhibit the effect as a flame retardant aid in the total resin composition, it is necessary to add 0.5% by weight or more, and in order not to reduce the mechanical strength of the resulting molded product, 1% or more is required.
It is necessary to make the blending amount 0% by weight or less.

The polyethylene terephthalate resin composition of the present invention may optionally contain various additives such as fillers such as wollastonite, mica glass foil, clay or kaolin, stabilizers against light or heat, dyes or pigments. It is also possible to add

When manufacturing a molded article from the resin composition of the present invention,
As in the past, a predetermined amount of the components are put into a suitable mixing machine such as an extruder, and after being mixed and kneaded to form pellets,
A molded article can be obtained by injection molding or pressure molding. In this case, a feature is that even if a relatively thin-walled molded product is molded at a mold temperature of 100° C. or less, a molded product with sufficiently advanced crystallization can be obtained.

In the resin composition of the present invention, it is necessary to blend the above-mentioned (C1 to CF+ components together with the glass fiber reinforced polyethylene terephthalate resin, and in particular, a combination of (C1 to (g)) is necessary. If even one of these types is not included, sufficient effects cannot be obtained.If the resin composition of the present invention is used, the degree of crystallinity can be maintained even at a mold temperature of 100°C or less without reducing mechanical strength. A highly flame-retardant polyethylene terephthalate resin molded article can be obtained. Therefore, the resin molded article has excellent properties in terms of moldability, mold releasability, dimensional stability, etc.

〔Example〕

Hereinafter, the present invention will be explained in detail with reference to Examples. In the examples, parts indicate parts by weight.

Examples 1 to 9 A polyethylene terephthalate homopolymer with an intrinsic viscosity [η] of 0672, chopped strand glass fiber of 3u length (abbreviated as GF in the table) and the above (C)
~ (The Fl components were blended in the proportions shown in the table, and mixed for 5 minutes in a V-type blender to make it homogeneous.The resulting mixture was charged into a vent-type melt extruder with a diameter of 65 ml and the cylinder temperature was 260 ml. Pellets of the resin composition of the present invention were obtained by extrusion at a temperature of .degree. C. to 280.degree.

The pellet obtained here was molded into 3 ounces using an injection molding machine with a screw set of 30 mm in diameter, and the cylinder temperature was 270°C.
127X12 at mold temperature 80℃, molding cycle 30 seconds
, 7 x 1.6 mm and an ASTM-1 dumbbell were obtained. Using the strip specimen having a thickness of 1.6 mm, the crystallization energy ΔH during heating was measured using a differential calorimeter, and a combustion test using UL-94V was conducted.

A tensile test was also conducted using an ASTM-1 dumbbell.

Here, to measure ΔH using a differential calorimeter, cut out approximately the center of a 1.6-plate strip specimen and heat it at a heating rate of 10°C/min under a nitrogen stream. It was determined from the area of the peak Tc. In other words, this ΔH is the thermal energy when the amorphous portion, which was rapidly frozen during molding, progresses to crystallization by reheating, and the smaller ΔH is, the more advanced the crystallization is during molding. This indicates that there is less shrinkage and warping due to

Comparative Examples 1 to 4 Resin compositions were produced in the same manner as in the above Examples, except that the compounds shown in the table were used as additives, and the same tests were conducted. The results obtained are also listed in the table.

As is clear from the results in the table, by using components (C1 to (F)) together, the ΔH of the thin-walled molded products of 1 and 6 at a mold temperature of 80°C was extremely small, and crystallization progressed sufficiently. It can be seen that a molded article can be obtained.On the other hand, as shown in Comparative Examples 2 and 3, just by changing the flame retardant component (g), ΔH increases by 3 to 4 times, resulting in poor crystallization. Become.

[Effects of the Invention] As detailed above, the polyethylene terephthalate resin composition of the present invention has (C) to
(By blending the Fl component with the glass fiber-reinforced polyethylene terephthalate resin, it is possible to obtain a product that has a high crystallization rate and exhibits good moldability and mechanical strength even under molding conditions of 100°C or lower. .

Claims (1)

[Claims] (A) Polyethylene terephthalate resin 30% to 85% by weight (B) Glass fiber 5% to 60% by weight (C) Nucleating agent 0.03% to 20% by weight (D) General At least one type selected from monoepoxy compounds represented by formula (I) 0.1% to 10% by weight ▲ Numerical formulas, chemical formulas, tables, etc. are available ▼ (I) However, R_1: Hydrocarbon having 6 or more carbon atoms R_2 : Hydrocarbon having 2 to 6 carbon atoms n: An integer of 0 or 1 or more (E) 2% to 20% by weight of a polymer-type brominated flame retardant having a brominated aromatic ring in the side chain of the polymer (F ) A flame-retardant polyethylene terephthalate resin composition comprising 0.5% to 10% by weight of antimony oxide, and the total amount of each component (A) to (F) is 100% by weight.