JPH037757A - Polyester resin composition for molding - Google Patents

Abstract

PURPOSE:To obtain the subject composition capable of providing molded products, having good surface gloss and excellent in mechanical properties such as impact resistance and rigidity by blending prescribed amounts of a reinforcing material with a specific olefinic copolymer and polyfunctional compound. CONSTITUTION:A polyester resin composition obtained by blending (A) 100 pts.wt. polyethylene terephthalate with (B) 1-150 pts.wt. fibrous and/or particulate reinforcing material, (C) 1-100 pts.wt. olefinic copolymer composed of a 2-4C alpha-olefin and glycidyl ester of an alpha,beta-unsaturated acid expressed by the formula (R is H or lower alkyl) and (D) 0.001-10 pts.wt. at least one of polyfunctional compound selected from epoxysilanes, diepoxy compounds, epoxidized polybutadienes, triglycidyl isocyanurate, diisocyanates, both-terminal isocyanate polyurethanes and tetracarboxylic acid dianhydrides.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a polyester resin composition that has good surface gloss and can provide molded articles with excellent mechanical properties such as impact resistance and rigidity.

Due to its excellent properties, polyethylene terephthalate is used in a wide range of fields such as electrical and electronic equipment parts and automobile parts. Among these, polyethylene terephthalate is used in fibrous materials such as glass fiber in applications that require particularly high rigidity and high heat distortion temperature. Most commonly used are methods of modifying materials by adding reinforcing materials or granular reinforcing materials such as talc. However, molded products obtained from polyethylene terephthalate blended with reinforcing agents in this manner are extremely poor in appearance, including surface gloss, and there is a strong desire to improve this drawback. For this reason, attempts have been made to improve the appearance of molded products by adding various third additives, and even if the surface gloss can be improved to some extent, there are problems such as having to sacrifice impact resistance. However, the current situation is that no satisfactory means have yet been found.

Therefore, the present inventors conducted extensive studies with the aim of obtaining a polyester resin composition that has good surface gloss and can provide molded products with excellent mechanical properties such as impact resistance and rigidity. On the other hand, the present inventors have discovered that the above object can be achieved by blending specific amounts of a reinforcing material, a specific olefin copolymer, and a specific polyfunctional compound.

That is, the present invention uses polyethylene terephthalate 100
Based on parts by weight, (^) 1 to 150 parts by weight of fibrous and/or granular reinforcing material, (B) α-olefin having 2 to 4 carbon atoms, and α,β-unsaturated acid of general 2G) below. 1 to 100 parts by weight of an olefin copolymer consisting of glycidyl ester (in the formula, R is a hydrogen atom or a lower alkyl group) and fc) epoxysilane, jepoxy compound,
At least one polyfunctional compound selected from the group consisting of epoxidized polybutadiene, triglycidyl isocyanurate, diisocyanate, polyurethane with isocyanate at both ends, and tetracarboxylic dianhydride 0.001
The object of the present invention is to provide a polyester resin composition for molding comprising 10 parts by weight.

The polyethylene terephthalate used in the present invention is a polyester obtained by a condensation reaction of a dicarboxylic acid component in which at least 40 mol% of the dicarboxylic acid component is terephthalic acid and an ethylene glycol component. ,
2 carbon atoms such as sebacic acid, adipic acid, dodecanedioic acid, etc.
~20 aliphatic dicarboxylic acids, isophthalic acid, orthophthalic acid, two-phthalenedicarbodiic acid, diphenyl-4,
Examples include aromatic dicarboxylic acids such as 4'-dicarboxylic acid and diphenylethane-4,4'-dicarboxylic acid, and alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid, alone or in mixtures.

In addition, the above polyethylene terephthalate is 0.5%
It is preferable that the relative viscosity of the orthochlorophenol solution measured at 25°C is in the range of 1.2 to 2.0, particularly 1.3 to 1.8, and if it is less than 1.2, there is sufficient mechanical strength. If it exceeds 2.0, a molded product with good surface gloss cannot be obtained, so both are undesirable.

The reinforcing material used in the present invention is fibrous, granular, or a mixture of both. Fibrous reinforcement materials include glass fiber, glass fiber, alumina fiber, silicon carbide fiber,
Examples include inorganic fibers such as ceramic fibers, asbestos fibers, gypsum fibers, metal fibers (such as stainless steel fibers), and carbon fibers. In addition, granular reinforcing materials include wollastenite, sericite, cathartic, mica, clay, bentonite, asbestos, talc, silicates such as alumina silicate, alumina, silicon oxide, magnesium oxide, zirconium oxide, titanium oxide, etc. metal oxides, carbonates such as calcium carbonate, magnesine carbonate, and dolomite, sulfates such as calcium sulfate and barium sulfate, glass peas, boron nitride, silicon carbide, Saroyan, etc., and these may be hollow. (
For example, hollow glass fiber, glass micro balloon, glass balloon, carbon balloon, etc.). The above-mentioned reinforcing materials may be used after being pretreated with coupling agents such as silane-based and titanium-based, if necessary.

The amount of reinforcing material added above is polyethylene terephthalate 1
The amount is 1 to 150 parts by weight, preferably 3 to 80 parts by weight.

If the amount added is less than 1 part by weight, sufficient mechanical strength cannot be obtained, and if it exceeds 150 parts by weight, the surface gloss tends to be impaired, making it difficult to achieve the object of the present invention.

The α-olefins used in the present invention are ethylene, propylene, butene,
1, and ethylene is preferably used. Also α
, glycidyl esters of β-unsaturated acids are compounds represented by the general formula (in the formula, R is a hydrogen atom or a lower alkyl group), and specifically glycidyl acrylate, glycidyl methacrylate, ethacrylic acid Among them, glycidyl methacrylate is preferably used. The amount of the copolymer of glycidyl ester of α,β-unsaturated acid is suitably in the range of 1 to 50% by weight. Furthermore, 4
If it is 0% by weight or less, unsaturated monomers that can be copolymerized with the above copolymers, such as vinyl ethers, vinyl ester acids such as vinyl acetate and vinyl propionate, acrylic acids and methacrylic acids such as methyl, ethyl, and propyl, are used. One or more types of esters, acrylonitrile, styrene, carbon oxide, etc. may be copolymerized.

The amount of the olefin copolymer added is 1 to 100 parts by weight, preferably 3 to 50 parts by weight, per 100 parts by weight of polyethylene terephthalate. If the amount added is less than 1 part by weight, the surface gloss will not be improved sufficiently, and if it exceeds 100 parts by weight, the surface gloss will tend to be impaired, making it difficult to achieve the object of the present invention.

Next, examples of the polyfunctional compound used in the present invention include epoxysilane, jepoxy compound, epoxidized polybutadiene, triglycidyl isocyanurate, diisocyanate, polyurethane with isocyanate at both terminals, and tetracarboxylic dianhydride. Specifically, epoxysilanes such as γ-glycidoxyzolopyltriethoxysilane, γ-glycidoxypropylmethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, bisphenol A type epoxy compounds, Bisphenol F-type epoxy compounds, resorcinol-type epoxy compounds, tetrahydroxyphenylmethane-type epoxy compounds, novolac-type epoxy compounds, alicyclic compound-type epoxy compounds such as vinylcyclohexene dioxide, dicyclopentadiene oxide, glycidyl ethers,
Epoxidized polybutadiene, polyepoxy compounds such as triglycidyl isocyanurate, 2,4-tolylene diisocyanate, 4,4-mono-diphenylmethane diisocyanate, tridene diisocyanate, hexamethylene di-unsocyanate, metaxylylene di-isocyanate,
Incyanate compounds such as 1,5-naphthalene diisocyanate, polyphenylisocyanate, and derivatives of the above isocyanates (polymer urethane, oligomers higher than uretidione dimer, cyanurate polymer), pyromellitic anhydride, naphthalene tetracarboxylic Acid dianhydride and general formula (wherein X is -0-1-8
O2--co- or divalent hydrocarbon. ), for example, carboxylic acid anhydrides such as bis(3,4-dicarboxyphenyl)alkane dianhydride. Among these polyfunctional compounds, preferred are bisphenol A-type epoxy compounds represented by the general formula (where n is a number of 0 to 20). Note that the above polyfunctional compounds can be used alone or in combination of two or more,
The total amount added is 0.001 to 10 parts by weight, preferably 0.0 parts by weight, per 100 parts by weight of polyethylene terephthalate.
It is used in a range of 0.05 to 5 parts by weight. The amount added is 0.00
If the amount is less than 1 part by weight, the surface gloss will not be improved sufficiently;
If the amount exceeds 10 parts by weight, the surface gloss tends to be impaired, making it difficult to achieve the object of the present invention.

To the composition of the present invention, antioxidants and heat stabilizers (including, for example, hindered phenols, hydroquinones, thioethers, phosphites, substituted products thereof, and combinations thereof), to the extent that the objects of the present invention are not impaired; UV absorbers (e.g. various resorcinols, salicyle-1)
-, benzotriazole, benzophenone, etc.), lubrication and mold release agents (e.g. stearic acid and its salts, montanic acid and its salts, esters, half esters, stearyl alcohol, stearamide, etc.), dyes (e.g. nitrosine, etc.) and pigments. (e.g. cadmium sulfide,
phthalocyanine, carbon black, etc.), flame retardants (e.g., decabromodiphenyl ether, halogen-based materials such as brominated polycarbonate I~, melamine or cyanuric acid-based materials, phosphorus-based materials, etc.), flame retardants (e.g., antimony oxide, etc.); ), antistatic agents (eg, sodium dodecylbenzenesulfonate, polyalkylene glycol, etc.), crystallization promoters, and the like can be added. Also small amounts of other thermoplastics (
For example, polyethylene, polypropylene, acrylic resin,
Fluororesin, polyamide, polyacetal, polycarbonate, polysulfone, polyphenylene oxide, etc.), thermosetting resin (e.g. phenol resin, melamine resin, polyester resin, silicone resin, epoxy resin, etc.), soft thermoplastic resin (e.g. ethylene/vinyl acetate) Polymers such as polyester elastomer 1 2 ethylene/propylene terpolymer) may also be added, and these resins may be used not only alone but in combination of two or more.

Although the method for producing the composition of the present invention is not particularly limited, a preferred method is to melt-knead polyethylene terephthalate, an olefin copolymer, a polyfunctional compound, and a reinforcing material in an extruder, and then cut it into pellets. Can be mentioned. Furthermore, as a method for adding a polyfunctional compound, a method in which glass fibers are pretreated and added is also often used.

The resin composition of the present invention can be easily molded by conventional methods such as injection molding and extrusion molding, and the resulting molded product exhibits excellent properties.

The present invention will be explained below with reference to Examples.

<Example> Examples 1 to 6, Comparative Examples 1 to 6 Polyethylene terephthalate 100 with a relative viscosity of 1.34
Based on parts by weight, ethylene/glycidyl methacrylate (
90/10 weight ratio) copolymer, γ-crisitoxypropylmethoxysilane and glass fiber (3 long chopped strands) were tri-blended in the proportions shown in Table 1, and 28
The mixture was melted and mixed into pellets using a screw extruder set at 0°C. Next, the obtained pellet was molded using an injection molding machine set at 280°C, with the mold temperature set in the range of 70°C to 120°C, to form a mold of 80 nm x 80 in x 2.
Prepare 1/2 inch wide Izot impact test specimens according to the ASTM D256 standard. Using these test pieces, the appearance (surface gloss, color tone) of the molded products was observed, and the Izod impact value was measured, and the results shown in Table 1 were obtained.

For comparison, a composition obtained by appropriately removing additives other than polyethylene terephthalate and glass fiber from the above composition was similarly evaluated.

It can be seen that by using the ethylene/glycidyl methacrylate copolymer, a molded article having a good appearance can be obtained even at a mold temperature of 70°C, and that the surface gloss is further increased by increasing the mold temperature to 120°C.

Furthermore, it can be seen that such a copolymer increases the Izot impact strength, and that γ-glycidoxypropylmethoxysilane is essential for imparting surface gloss in the coexistence of a modified polyolefin copolymer.

Examples 7 to 15, Comparative Examples 7 to 16 Polyethylene prephthalate 100 with a relative viscosity of 1.39
Based on the weight part, ethylene/glycidyl methacrylate/vinyl acetate (82/12/
6 polymerization ratio) 20 parts by weight of copolymer, 40 parts by weight of glass fiber (3-length chopped strand), 20 parts by weight of wollastenite
After triblending the types and amounts of polyfunctional compounds shown in the parts by weight and in Table 2, melt mixing, injection molding and property evaluation were carried out in the same manner as in Example 1. The results obtained are shown in Table 2.

As is clear from the results in Table 2, the composition of the present invention, which uses both an olefin copolymer and a polyfunctional compound,
The impact strength is synergistically improved and the surface gloss of the molded product is improved.

Regarding the surface gloss of the molded product, the difference from the comparative example becomes large especially when the mold temperature becomes low, and it is clear that the effect of the composition of the present invention is excellent.

Claims (1)

[Claims] For 100 parts by weight of polyethylene terephthalate, (A
) 1 to 150 parts by weight of fibrous and/or granular reinforcing material, (B) α-olefin having 2 to 4 carbon atoms and the following general formula (
1 to 100 parts by weight of an olefin copolymer consisting of α, β-unsaturated acid glycidyl ester of I) ▲ Numerical formulas, chemical formulas, tables, etc. are available▼・・・・・・(
) (In the formula, R is a hydrogen atom or a lower alkyl group.)
and (C) at least one polyfunctional compound selected from the group consisting of epoxysilane, diepoxy compound, epoxidized polybutadiene, triglycidyl isocyanurate, diisocyanate, polyurethane with isocyanate at both ends, and tetracarboxylic dianhydride 0.001 ~1
A molding polyester resin composition containing 0 parts by weight.