JPS5989347A - Polyester resin composition - Google Patents

Abstract

PURPOSE:To obtain a composition having small temperature-dependence of the melt viscosity and broad injection temperature range, and giving a molded article having excellent surface appearance, by compounding an epoxy compound to a modified polyethylene terephthalate resin. CONSTITUTION:The objective resin is prepared by compounding 95-99.98pts.wt. of a modified polyethylene terephthalate resin copolymerized with a polyoxyalkylene compound with 5-0.02pts.wt. of an epoxy compound. The modified polyethylene terephthalate resin is preferably the one copolymerized with a polyoxyalkylene compound containing organic acid metal salt, especially with 4-40wt% of a polyoxyalkylene compound, and the epoxy compound is preferably diglycidyl phthalate.

Description

[Detailed description of the invention] The present invention relates to a polyester resin composition.

More specifically, the present invention relates to a polyester resin composition in which the injection molding temperature is increased by incorporating an epoxy compound into a modified polyethylene terephthalate resin whose crystallinity has been increased by copolymerizing a polyoxyalkylene compound.

A high molecular weight linear polyethylene terephthalate resin obtained from a dicarboxylic acid or its ester-forming derivative mainly consisting of brellataric acid and a diol mainly consisting of ethylene glycol or its ester-forming derivative has a high softening point and is heat resistant. It is widely used in fibers, films, and molded products because it has excellent electrical, physical, and mechanical properties, including durability, chemical resistance, and light resistance.

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. However, the viscosity of modified polyethylene terephthalate resins generally has a large temperature dependence in the molten state, and depending on the modification method, thermal decomposition may occur, resulting in an extreme decrease in viscosity, which limits the temperature during injection molding. In addition, the surface appearance of the molded product may be significantly impaired.

In view of the above circumstances, the inventors of the present invention have conducted intensive studies to solve these problems, and have surprisingly found that by incorporating a specific amount of an epoxy compound into the modified polyethylene terephthalate resin, the viscosity temperature in the molten state can be increased. The inventors have discovered that a composition with slow dependence, a wide range of injection molding temperatures, and an excellent surface appearance of molded articles can be obtained, and has thus arrived at the present invention.

That is, the present invention provides modified polyethylene terephthalate resins 95 to 99 copolymerized with polyoxyalkylene compounds.
．． The content is a polyester resin composition consisting of 98 parts by weight and 5 to 0.02 parts by weight of an epoxy compound.

The modified polyethylene terephthalate resin used in the present invention refers to a resin obtained by copolymerizing a polymer containing ethylene terephthalate units as a main component with a modifier component that promotes crystallization.

Polymers containing ethylene terephthalate units as a main component include, after direct esterification or transesterification from a dicarboxylic acid component in which at least 90 mol% is terephthalic acid and a diol component in which at least 90 mol% is ethylene glycol; It is obtained by polycondensation.

0 to 10 mol% of the dicarboxylic acid component is other aromatic dicarboxylic acid having 6 to 14 carbon atoms, aliphatic dicarboxylic acid having 4 to 8 carbon atoms, or alicyclic dicarboxylic acid having 8 to 12 carbon atoms. Examples of such dicarboxylic acids include phthalic acid, iso-esteric acid, 2,6-knuclendicarboxylic acid, 4,4'-diphenyldicarboxylic acid, diphenylethane-4,4'-dicarboxylic acid. , adipic acid, sebacic acid, cyclohexanedicarboxylic acid, and the like.

0 to 10 mol% of the diol component has 3 to 10 carbon atoms
may be an aliphatic diol having 6 to 15 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 propane-1,3-diol, butane-1,4-diol, pentane-1,5-diol,
-diol, hexane-1,6-diol, cyclohexane-1,4-dimetatool, 2,2-dimethylpropane-1,3-diol, 2,2-bis(4'-hydroxycyclohegycyl)-propane , 2,2-bis-(4'
-hydroxyphenyl)propane, hydroquinone, =
It can be mentioned. Furthermore, oxycarboxylic acids, e.g.
-Oxycaproic acid, hydroxybenzoic acid, etc. may be copolymerized. Of course, it may be branched with trihydric or tetrahydric alcohols or tribasic or tetrabasic acids; examples of suitable branching agents include trimesic acid, trimellitic acid, trimethylolpropane, Examples include erythritol.

The modifier component to be copolymerized includes all types of polyoxyalkylene compounds that can promote crystallization. A specific example will be shown below.

(a) Polyalkylene glycols; examples include polyethylene glycol, polypropylene glycol, polytetramethylene glycol, and the like.

(b) Polyoxyalkylene compounds having organic acid metal salts; for example, monosuccinate potassium salts, monosuccinate potassium salts, calcium salts of polyethylene glycol, polypropylene glycol, polytetramethylene glycol, ethylene oxide-propylene oxide copolymers, etc. , zinc salt, aluminum salt, monotetrabromophthalic acid ester sodium salt, chrycerin-alkylene/oxide adduct, phthalic acid ester sodium salt of tri5methylolprohane-alkylene oxide adduct, and tetrabromophthalic acid ester sodium salt, Sodium salts and calcium salts of sulfonic acid or valic acid of phenyl ethers such as polyethylene glycol, polypropylene glycol, polytetramethylene glycol, ethylene oxide-propylene oxide copolymer, and polyhydric alcohol-alkylene oxide adducts can be used.

(c) Polyoxyalkylene compounds having epoxy groups; for example, polyethylene glycol, polypropylene dalycol, polytetramethylene glycol, mono- and dicrycidyl ethers such as ethylene oxide-propylene 7 oxide copolymer, methoxy polyethylene glycol, Examples include monoglycidyl ether of polyethylene glycol, glycerin-alkylene oxide adduct, trimethylolpropane-alkylene oxide adduct, and glycidyl ether of benquerythritol-alkylene oxide adduct.

Although specific examples have been shown above, the modifying material of the present invention is not limited to these only. Further, the modifier may be used alone or in combination of two or more.

These modifiers can be introduced directly after esterification or after transesterification, or they can be added in the middle or final stage of polycondensation to cause copolymerization, but depending on the type of modifier, an advantageous method may be selected. You can choose. The amount of modifier added varies depending on the individual and the degree of crystallization promotion, but generally speaking, when considering the balance of moldability, physical properties, etc., a range of 4 to 40% by weight is suitable for the purpose. achieved. Among these modifiers, a modified polyethylene terephthalate resin copolymerized with a polyoxyalkylene compound having an organic acid metal salt is most advantageous.

The epoxy compound used in the present invention refers to a compound having an oxirane ring in the molecule, and various commercially available epoxy compounds can be used. Specifically, bisphenol-type epoxides, novolak-type epoxides, resol-type epoxides, aliphatic-type epoxides, alicyclic-type epoxides, polyhydric alcohol epoxides, epoxides having an aromatic ring, etc. can be mentioned, among others,
Bisphenol"A diepoxide, terephthalic acid diglycidyl ester, and phthalic acid diglycidyl ester are preferred. The amount added varies depending on the epoxy equivalent, but is generally 0.02 to 5 parts by weight. Less than 0.02 parts by weight. There is no effect if the amount added exceeds 5 parts by weight, and injection molding often becomes difficult.

If necessary, a reinforcing filler can be added to the composition of the present invention to further improve its physical properties.

Suitable reinforcing fillers include glass fibers, mineral fibers, talc, mica, camelin, and the like. Moreover, a flame retardant can be added to the composition of the present invention as needed to impart twist resistance. Suitable flame retardants include halogenated diphenyl ether compounds, halogenated polycarbonate compounds, halogenated polyphenylene oxide compounds, halogenated bisphenol resins, halogen-containing s-v azine compounds, and red phosphorus flame retardants. If necessary, flame retardant aids such as antimony trioxide and zinc borate may be added to these to develop a synergistic effect.

To produce the composition of the present invention, a modified polyethylene terephthalate resin and an epoxy compound may be mixed by a known method. Examples include a method of adding and blending during the production of modified polyethylene terephthalate resin, and a method of mixing and extruding using an extruder.

The composition of the present invention may contain polyamide-based polymers, polycarbonate-based polymers, etc. for the purpose of improving mechanical and electrical properties, and may also contain diene-based rubber, acrylic rubber-based polymer, butyl rubber, etc. It may contain thermoplastic rubbers such as ethylene-propylene copolymers, ethylene-vinyl acetate copolymers, urethane rubbers, epichlorohydrin rubbers, and silicone rubbers. Furthermore, other additives,
For example, thermal antioxidants, light stabilizers, pigments, dyes, nucleating agents, plasticizers, lubricants, etc. may be added to the extent that the physical properties are not impaired.

By doing so, it is possible to obtain a composition whose viscosity in a molten state has a slow temperature dependence, which can be used over a wide range of injection molding temperatures, and which has an excellent surface appearance of a molded article. The composition of the present invention comprises:
Can be widely used for forming various molded parts, pipes, containers, etc.
It is particularly suitable for use in electrical parts, building material parts, automobile parts, etc., and can also be used in fibers, films, and sheets.

The present invention will be explained below with reference to Examples 7', but the present invention is not limited to these Examples.

In the examples, the intrinsic viscosity of the modified polyethylene terephthalate resin [η] was determined from the logarithmic viscosity measured in haphenol/tetrachloroethane (1:1 parts by weight) at 25°C at a concentration of 5 g/d1. .

Open I point Tm, cooling crystallization temperature from molten state':'c(
C) The heating crystallization temperature Tc (H) from the glass state was measured using a Perkin-Elmer DSC-type. The tensile strength of the molded product is AST M-D638, and the heat distortion temperature (i 8.61cg/cA) is AST
M-D648, flame retardancy was measured in accordance with the U L-94 vertical test method. Molding temperature 1] was investigated by injection molding by changing the barrel temperature of a Yero molding machine, and evaluating the surface appearance and tensile strength retention rate. Further, the amounts added in each example are parts by weight.

Examples 1 to 2, Comparative Example 1 Modified polyethylene teret)PV-te resin (A) obtained by copolymerizing 15% by weight of polyethylene glycol monotrimellitic acid ester disodium salt having an average molecular weight of 1740 (
(η) Twenty. 69, Tm=258°C, Tc (H)
= 86°C, Tc(C)-210°C], sodium palmitate, diglycidyl terephthalate (epoxy equivalent: 119), mineral fiber (processed mineral fiber), and glass fiber (fiber length 3πm) as shown in Table 1. After extrusion mixing at the ratio of , various molding temperatures, holding pressure for 10 seconds,
Injection molding was performed with cooling for 30 seconds to obtain a test piece. Incidentally, as Comparative Example 1, a similar test was conducted in the case where diglycidyl terephthalate was not used.

The obtained results are shown in Table 1. All of the Examples of the present invention maintained their physical properties, had little decrease in retention rate, and had excellent surface appearance. On the other hand, the comparative example had poor retention rate and poor surface appearance.

Table 1 Examples 3 to 4, Comparative Example 2 Bot. 1 with an average molecular weight of 1740. +Ethylene glycol mono-1-limeriz;-Modified polyethylene tere-Vtate resin (B
) (C77) 20.73, T+r+=250”C
, Tc (H) = 96°Q, TC(C) = 212°
C), terephthalic acid dichloride/I/(epoxy dichloromethane)
139), decabromodiphenyl ether, antimony trioxide, 'MIA YJJ, processed mineral fine veneer, and glass fiber (fiber length 3 mm) were extruded and mixed in various ratios as shown in Table 2, and then various A test piece was obtained by injection molding at a molding temperature of 10 seconds while holding pressure and cooling for 30 seconds.As Comparative Example 2, the same operation was performed for a sample that did not contain denfucuric acid or diglycidyl.

As is clear from the results in Table 2, the examples of the present invention maintained their physical properties, had little decrease in retention rate, and had excellent front appearance. On the other hand, the comparative examples were also unsatisfactory in both retention rate and surface appearance.

Table 2 Examples 5 to 6, Comparative Example 3 Modified polycoach lentithhalet-1-resin (A) used in Examples 1 to 2, bisphenol A diglycidyl ether (jfl 180 per epoxy), cyanuric acid '4A and tetrabromobisphenol j′1. and (−
Libromophenol condensate (average molecular weight approximately 8000,
Softening point: 220°C, bromine content: 62% by weight), antimony trioxide, and glass fiber were extruded and mixed at various ratios shown in Table 3, followed by various molding temperatures, holding pressure for 10 seconds, and cooling for 30 seconds. A test piece was obtained by injection molding.

The results are shown in Table 3, and all of the Examples of the present invention maintained their physical properties, had little decrease in retention rate, and had excellent surface appearance. On the other hand, in Comparative Example 3, which did not contain bisphenol A diglycidyl ether, both the retention rate and the surface appearance were poor.

Table 3

Claims (1)

[Scope of Claims] (1) A polyester resin composition comprising 95 to 99.98 parts by weight of a modified polyethylene terephthalate resin copolymerized with a polyoxyalkylene compound and 5 to 0.02 parts by weight of an epoxy compound. 2. The composition according to claim 1, which is a copolymer of a modified polyethylene terephthalate resin or a polyoxyalkylene compound having an organic acid metal salt. 8 Modified polyethylene terephthalate resin is 4 to 40
The composition according to claim 1 or 2, which is obtained by copolymerizing i% of a polyoxyalkylene compound.