JPS6377965A - Flame-retardant polyester resin composition - Google Patents

Abstract

PURPOSE:To provide the title compsn. having excellent thermal stability, etc. and improved properties with regard to dripping, by mixing a specified modified polyethylene terephthalate resin with a polyphenylene sulfide resin, a brominated polystyrene and a reinforcing filler. CONSTITUTION:100pts.wt. modified polyethylene terephthalate resin (A) having a heat crystallization temp. Tc(H) of not higher than 120 deg.C is mixed with 0.5-5 pts.wt. polyphenylene sulfide resin (B), 3-30pts.wt. brominated polystyrene (C) (e.g., polytribromostyrene) and 5-200pts.wt. reinforcing filler (D) (e.g., glass fiber) to obtain the desired flame-retardant polyester resin compsn. The component A can be prepd. by introducing a modifier component such as polyethylene glycol, an adduct of ethylene oxide to bisphenol A or sodium polypropylene glycol diphthalate into a polyethylene terephthalate resin.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a flame-retardant polyester resin composition for molding.

[Prior art/problems to be solved by the invention] A high molecular weight line obtained from a dicarboxylic acid mainly consisting of terephthalic acid or its ester-forming derivative, and a diol mainly consisting of ethylene glycol or its ester-forming derivative Polyethylene terephthalate resin has a high softening point, heat resistance, chemical resistance, light resistance, and excellent electrical properties and physical and mechanical properties, so it is widely used as fibers, films, and molded products. It is used.

Since such polyethylene terephthalate resin has a slow crystallization rate, it is industrially advantageous to use it as a modified polyethylene terephthalate resin whose crystallization rate is increased by introducing various crystallization promoters, mainly for injection molding applications. It is.

Such polyethylene terephthalate resins originally have poor flame retardancy, and modified polyethylene terephthalate resins are also difficult to make flame retardant.

Conventionally, methods for making modified polyethylene terephthalate resin flame retardant include using halogen compounds, phosphorus compounds, nitrogen compounds, etc. together with flame retardant additives, as with ordinary polyethylene terephthalate. When a flame retardant is used, poor dispersion tends to occur, resulting in a decrease in mechanical properties such as tensile strength, and bleeding, where the flame retardant leaches onto the surface of the molded product. There are many problems.

By adding halogen-containing polymers such as halogenated polyphenylene oxide and halogen-containing S-)riazine compounds, or a combination of these and other flame retardants to modified polyethylene terephthalate resin, mechanical properties can be improved. Methods have also been discovered that provide superior flame retardancy, virtually no bleeding, and yet a high degree of flame retardancy.

However, when flame retardant test pieces are subjected to flame retardant tests using a method compliant with UL-94, a phenomenon called dripping occurs in which the burned resin particles ignite the cotton underneath. This is often seen, and there are cases where it cannot be said that it has a stable and high degree of flame retardancy.

In order to solve this problem, increasing the amount of flame retardant has been considered, but although it may be possible to impart a stable high degree of flame retardancy, it generally impairs the mechanical properties and economic efficiency of the product. It is true.

Additionally, modified polyethylene terephthalate resins containing these flame retardants have low thermal stability at high temperatures;
This poses a major obstacle to its application to electrical components.

The present invention has been made to solve the above problems.

[Means for Solving the Problems] As a result of intensive studies based on this viewpoint, the present inventors surprisingly found that when making modified polyethylene terephthalate resin flame retardant, it was found that By using brominated polystyrene and a specific small amount of polyphenylene sulfide resin, dripping is improved, and a composition that has stable high flame retardancy and excellent thermal stability at high temperatures can be obtained. They discovered this and completed the present invention.

That is, the present invention comprises: (a) 100 parts (parts by weight, the same applies hereinafter) of a modified polyethylene terephthalate resin whose heating crystallization temperature Tc (H) is 120°C or less +b + 0.5 to 5 parts of polyphenylene sulfide resin (c) The present invention relates to a flame-retardant polyester resin composition containing 3 to 30 parts of brominated polystyrene and 5 to 200 parts of a small reinforcing filler.

[Example] In the present invention, the modified polyethylene terephthalate resin (a) having a heating crystallization temperature Tc (H) of 120°C or less is a resin in a glass state that is heated to room temperature using a scanning differential calorimeter (DSC). The heating crystallization temperature when heated at a heating rate of 10°C/min is called Tc(1), and this is 12
Refers to temperatures below 0°C.

The modified polyethylene terephthalate resin has at least 9
A dicarboxylic acid component containing up to 0 mol% of terephthalic acid and a diol component containing at least 90 mol% of ethylene glycol are either directly esterified or obtained by polycondensation after a transesterification reaction, etc. This is the base, and a modifier component is further introduced.

0 to 10 mol% of the remainder of the dicarboxylic acid component has 6 carbon atoms.
-14 other aromatic dicarboxylic acids, aliphatic dicarboxylic acids having 4 to 8 carbon atoms, or alicyclic dicarboxylic acids having 8 to 12 carbon atoms. Examples of such dicarboxylic acids include, for example, phthalic acid, isophthalic acid, 2,6-naphthalene dicarboxylic acid, 4,4°-diphenyldicarboxylic acid, diphenylethane-4,4°-dicarboxylic acid, adipic acid, sebacic acid. , cyclohexanedicarboxylic acid, etc.

Further, 0 to 10 mol % of the remainder of the diol component may be an aliphatic diol having 3 to 10 carbon atoms, an alicyclic diol having 6 to 15 carbon atoms, or an aromatic diol having 6 to 12 carbon atoms. Examples of such diols include, for example, propane-1,3-diol, butane-1,4-diol, pentane-1,5-diol, hexane-1,6-diol, cyclohexane-1,4-dimetatool, 2,
2-dimethylpropane-1,3-diol, 2.2-bis(4°-hydroxycyclohexyl)propane, 2.
Examples include 2-bis(4-hydroxyphenyl)propane and hydroquinone.

Furthermore, oxycarboxylic acids such as ε-oxycaproic acid, hydroxybenzoic acid, etc. may be copolymerized in an amount of 10 mol % or less of the dicarboxylic acid component and diol component.

Of course, modified polyethylene terephthalate resin is
It may also be branched with a trihydric or tetrahydric alcohol or a tribasic or tetrabasic acid. Examples of such branching agents include trimesic acid, trimellitic acid, trimethylolpropane, pentaerythritol, and the like.

The modifier component to be introduced is not particularly limited as long as it is a variety of compounds that can reduce the above-mentioned Tc (II) to 120° C. or lower.

Specific examples of such compounds are shown below.

(1) Polyoxyalkylene compounds (a) Polyalkylene glycols Examples include polyethylene glycol, polypropylene glycol, polytetramethylene glycol, ethylene oxide/propylene oxide copolymer (random or block), and the like.

(b) alkylene oxide adducts of bisphenols, such as ethylene oxide adducts of bisphenol A;
Examples include a propylene oxide adduct of bisphenol A and an ethylene oxide/propylene oxide adduct of bisphenol A.

(/) Polyoxyalkylene compounds containing organic acid metal salts, such as mono- and/or disuccinate potassium salts, mono- and () or) cyphthalic acid ester sodium salt, calcium salt, zinc salt, aluminum salt, mono- and (or) di(tetrabromo) phthalic acid ester sodium salt,
Monotrimellitic acid ester sodium salt of monomethoxypolyethylene glycol, glycerin-alkylene oxide adduct, mono-, di- or triphthalic acid ester sodium salt of trimethylolpropane-alkylene oxide adduct, and/or mono-, di- or tribromophthalate. Acid ester sodium salt, polyethylene glycol, polypropylene glycol, polytetrameryl ester glycol, ethylene oxide-propylene oxide copolymer, polyhydric alcohol-alkylene oxide adduct, etc. Sulfonic acid or mono-, di-, tri- or tetra-phenyl ethers Examples include sodium salt and calcium salt of phosphoric acid.

) Polyoxyalkylene compounds having epoxy groups such as mono- and/or diglycidyl ethers such as polyethylene glycol, polypropylene glycol, polytetramethylene glycol, ethylene oxide-propylene oxide copolymer, methoxy polyethylene glycol, ethoxy polyethylene glycol Examples include monoglycidyl ethers of, glycerin-alkylene oxide adducts, trimethylolpropane-alkylene oxide adducts, and pentaerythritol-alkylene oxide adducts.

(e) Polyoxyalkylene compounds having a hydrocarbon group, such as mono- and/or di-nonylphenyl ether, octylphenyl ether, such as polyethylene glycol, polypropylene glycol, polytetramethylene glycol, ethylene oxide-propylene oxide copolymer, etc. Examples include oleyl ether, stearyl ether, lauryl ether, and palmityl ether.

(2) Low molecular weight organic esters such as neopentyl glycol dibenzoate, diethylene glycol dibenzoate, triethylene glycol dibenzoate, dipropylene glycol dibenzoate, butane-1,3-diol adipate oligomer, butane-1,4-diol adipate oligomer ,
Examples include hexane-1,6-diol adipate oligomer, dibutyl sebacate, and dioctyl sebacate.

(3) Ionic copolymers Refers to salts such as copolymers of α-olefins and α,β-unsaturated carboxylic acids, such as sodium salts, potassium salts, or zinc salts of ethylene/maleic acid copolymers, ethylene /Sodium salt, potassium salt or zinc salt of methacrylic acid copolymer, sodium salt, potassium salt or zinc salt of ethylene/itaconic acid copolymer, styrene/
Examples include sodium salt, potassium salt, or zinc salt of maleic anhydride copolymer. The carboxylic acid may be only partially or completely neutralized.

(4) Polyether polyester block copolymers Examples include copolymers of the compounds shown in (a) and (b) of (1) above with polyethylene terephthalate and/or polybutylene terephthalate.

Although the above description has been made based on specific examples, the modifier is not limited to these. Further, the modifier may be used alone or in combination of two or more.

These modifiers can be introduced by copolymerization and/or mixing, and an advantageous method may be selected depending on the type of modifier.

The amount of modifier added varies depending on the modifier, and Tc
(H) is added to bring the temperature below 120°C.

Generally speaking, when considering the balance of moldability, physical properties, etc., the objective can be achieved within a range of 4 to 40% (weight %, hereinafter the same).

Preferred modified polyethylene terephthalate resins include those obtained by copolymerizing alkylene oxide adducts of bisphenols, and mixtures of polyethylene terephthalate and polyether polyester block copolymers.

The scope of modified polyethylene terephthalate resin in the present invention does not include regular polyethylene terephthalate. If Tc(II) exceeds 120°C, no effect will be obtained even if a composition similar to that of the present invention is prepared.

Although the reason for this is not clear, it is thought that the crystallization promoter also has the effect of assisting the dispersion of flame retardants and the like.

The polyphenylene sulfide resin surface in the present invention has a repeating structure in which p-substituted benzene rings are bonded by sulfur atoms, which can be represented by the following general formula (I), and any commercially available polyphenylene sulfide resin (In the formula, n is an integer.) The amount added to 100 parts of the modified polyethylene terephthalate resin is a specific small amount of 0.5 to 5 parts, preferably 1 to 4 parts. If the amount added is less than 0.5 parts, the effect of improving dripping or improving the thermal stability under high temperatures is insufficient, and if the amount added exceeds 5 parts, the effect of improving the thermal stability under high temperatures is not sufficient. This is not preferable because it will impair the tensile strength.

The brominated polystyrene (c) in the present invention is a compound represented by the following general formula (I[), and any commercially available brominated polystyrene may be used.

(In the formula, X is a bromine atom, m is an integer of 1 to 5, and g is an integer.

) The amount added to 100 parts of the modified polyethylene terephthalate resin is 3 to 30 parts, and if it is less than 3 parts, flame retardation is insufficient, and if it exceeds 30 parts, the mechanical properties of the molded product will be impaired, so it is not preferable. .

Further, in order to efficiently exhibit the flame retardant effect, it is common to use flame retardant aids such as antimony trioxide and sodium antimonate together.

The reinforcing filler +d+ in the present invention refers to an inorganic filler in the form of fibers, plates, or particles, and by blending these, mechanical strength, heat distortion temperature, etc. can be further increased. Specific examples of such reinforcing fillers include glass fiber, mineral fiber, carbon fiber, silicon carbide fiber, boron carbide fiber, potassium titanate fiber, gypsum fiber, mica, talc, kaolin, clay, asbestos, calcium silicate, Examples include calcium sulfate and calcium carbonate, but glass fiber, mica, and talc are particularly preferred.
These may be used alone or in combination of two or more. Further, the surface may be treated with a silane coupling agent or the like in order to improve the affinity with the resin.

The amount of the modified polyethylene terephthalate resin is 1
If the amount is less than 5 parts, the mechanical strength cannot be sufficiently improved, and if it exceeds 200 parts, extrusion processing becomes difficult.

To produce the composition of the present invention, (■ modified polyethylene terephthalate resin) polyphenylene sulfide resin, (c) brominated polystyrene, and (d) reinforcing filler may be mixed in a conventional manner, and the extruder A common method is mixing and extrusion using a

The composition of the present invention contains commonly used nucleating agents such as Na palmitate, Na montanate, Na benzoate, p
-t-Butylbenzoic acid Na or the like may be added. Furthermore, with the aim of improving mechanical and electrical properties,
It may contain polyamide polymers, polycarbonate polymers, etc., diene rubbers, acrylic rubber polymers, butyl rubber polymers, ethylene-propylene copolymers, ethylene-vinyl acetate copolymers, urethane. Thermoplastic rubbers such as rubber, epichlorohydrin rubber, and silicone rubber may also be contained. Furthermore, other additives such as thermal antioxidants, light stabilizers, pigments, dyes, and lubricants are added to the extent that flame retardancy and other properties are not impaired.
May be blended.

In this way, it is possible to obtain a composition that has improved dripping, has a stable high degree of flame retardancy, and provides a molded article with excellent thermal stability at high temperatures.

The present invention will be described in detail below with reference to Examples, but the present invention is not limited to these Examples.

In the examples, the logarithmic viscosity (IV) of the modified polyethylene terephthalate resin was measured in phenol/tetrachloroethane (1:1 (weight ratio)) at 25° C. at a concentration of 0.5 g/dg. The heating crystallization temperature Tc (H) from the melting point Tl111 glass state was measured using a Perkin-Elmer DSC-I B type device. The tensile strength of the molded product is determined by ASTM-0838, heat distortion temperature (18,6 kg
/cj) is ASTM-0848, flame retardant is UL-9
4. Measured using a method based on the vertical test method.

Thermal stability was evaluated by tensile strength retention after being left in an oven at 180°C for 7 days.

Examples 1 to 2 and Comparative Examples 1 to 3 Modified polyethylene terephthalate resin (IV-0,60STm -2
53°C, Tc(H) -100°C), 100 parts of polyphenylene sulfide resin (Philips Vetroleum Co., trade name Rydon), polytribromostyrene (Nissan IC7■, trade name PC-811PI3), antimony trioxide. , glass fibers with a fiber length of 3 mm were mixed in the proportions shown in Table 1 and then injection molded, and test pieces were obtained and evaluated. The results are shown in Table 1.

Comparative Example 1 is a case in which polyphenylene sulfide resin is excluded, Comparative Example 2 is a case in which brominated polycarbonate (Ondai Kasei ■, trade name Fire Card) is used instead of polytribromostyrene, and Comparative Example 3 is a case in which brominated polycarbonate (Ondai Kasei ■, trade name Fire Card) is used. Evaluation was made in the same manner when 10 parts of polyphenylene sulfide was used. The results are shown in Table 1.

[Margin below] From the results in Table 1, it can be seen that the examples are excellent in flame retardancy and thermal stability.

However, in Comparative Example 2, flame retardant and
It can be seen that the thermal stability is poor, and that of Comparative Example 3 has decreased tensile strength and thermal stability.

Examples 3-4 Polyethylene terephthalate (IV-0,80) 85
and 15 parts of a polyether polyester block copolymer (IV-0,80) obtained by copolymerizing 30% of an ethylene oxide adduct of bisphenol A (number average molecular weight approximately 1000) with polyethylene terephthalate. Terephthalate resin (IV-
0,82, Ta+ -252°C, Tc(Il) -11
5° C.) to give the composition shown in Table 2, injection molding was performed, and test pieces were prepared and evaluated. Second result
Shown in the table.

From the results shown in Table 2, it can be seen that the flame retardance and thermal stability are excellent.

Comparative Example 4 In place of the modified polyethylene terephthalate resin of Example 1, polyethylene terephthalate (IV fine 0.θO, Tm -255°C) having a Tc (H) of 138°C was used and tested in the same manner. Flame retardancy 1 (W) was V-2, and thermal stability was also at a low level of 55%.

[Effects of the Invention] Molded articles made from the composition of the present invention have improved dripping, stable high flame retardancy, and excellent thermal stability at high temperatures.

Claims (1)

[Claims] 1(a) Modified polyethylene terephthalate resin having a heating crystallization temperature Tc (H) of 120°C or less
A flame-retardant polyester resin composition containing 100 parts by weight (b) 0.5 to 5 parts by weight of polyphenylene sulfide resin, (c) 3 to 30 parts by weight of brominated polystyrene, and (d) 5 to 200 parts by weight of a reinforcing filler.