JPH11130949A - Polyethylene terephthalate resin composition and molded article prepared therefrom - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polyethylene terephthalate resin compsn. excellent in mechanical properties, heat resistance, injection moldability, surface appearance, and fatigue resistance and a molded article prepd. therefrom. SOLUTION: This compsn. is prepd. by compounding 100 pts.wt. polyethylene terephthalate resin comprising 60-95 wt.% polyethylene terephthalate having an intrinsic viscosity of 0.5-0.8 dl/g and 5-40 wt.% polyethylene terephthalate having an intrinsic viscosity of 0.85-1.45 dl/g with 10-100 pts.wt. glass fibers with 0.6-1.5 wt.% binder attached thereto, 0.1-10 pts.wt. inorg. layered compd. having an average particle size of 0.1-4 μm, and 0.1-10 pts.wt. lubricant.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyethylene terephthalate resin composition having excellent mechanical properties, heat resistance, injection moldability, surface appearance, and fatigue resistance, and a molded article comprising the same.

[0002]

2. Description of the Related Art Polyethylene terephthalate resins are widely used as injection molded articles because of their excellent heat resistance, mechanical properties, chemical resistance and the like. Further, when the mechanical properties and heat resistance are insufficient, the composite is used by improving the mechanical properties and heat resistance by compounding an inorganic reinforcing agent. Among the inorganic reinforcing agents, glass fibers are widely used because of their great effect of improving the strength, but there is a problem that mechanical properties, heat resistance, injection moldability and surface appearance are inferior.

[0003] Therefore, many proposals have been made to improve the above-mentioned problems of glass fiber reinforced polyethylene terephthalate resin. For example, JP-B-48-6175,
JP-B-58-46151, JP-B-62-5354
No. 7, Japanese Patent Publication No. 1-60179, Japanese Patent Publication No. 63-
44786, JP-B-4-4341, JP-A-4-7351, JP-A-6-212065,
JP-B-44-15191 and JP-B-4-434.
In JP-A No. 1 (1999), compositions with epoxy compounds, compositions with glass fibers surface-treated with epoxy compounds, compositions with epoxy compounds and montan wax salts or montan wax ester salts, compositions with fillers such as talc Products, compositions of epoxy compounds and organic crystallization accelerators and solid inorganic fillers, and compositions of epoxy compounds and thermoplastic resins and phosphorus-based stabilizers have been proposed.

[0004]

However, in the above-mentioned prior art, although some of the above-mentioned problems of the glass fiber reinforced polyethylene terephthalate resin are improved, mechanical properties, heat resistance, injection moldability, surface appearance and resistance to heat are improved. No excellent fatigue properties have been obtained.

[0005] In addition, injection molded articles of the polyethylene terephthalate resin composition are required to be thinner for cost reduction and weight reduction, and are excellent in moldability and heat resistance as well as fluidity during injection molding. There is a need.

Accordingly, the present invention solves the above-mentioned problems of the prior art, and provides a polyethylene terephthalate resin composition excellent in mechanical properties, heat resistance, injection moldability, surface appearance, and fatigue resistance, and a molding comprising the same. It is an object to provide goods.

[0007]

Means for Solving the Problems The present inventors have made intensive studies to achieve the above object, and as a result, have reached the present invention.
That is, the present invention relates to a polyethylene terephthalate comprising 60 to 95% by weight of polyethylene terephthalate having an intrinsic viscosity of 0.5 to 0.8 dl / g and 5 to 40% by weight of polyethylene terephthalate having an intrinsic viscosity of 0.85 to 1.45 dl / g. (A) 0.6 to 100 parts by weight of resin
0.6-1.5% by weight with 1.5% by weight of sizing agent attached
10 to 100 parts by weight of glass fiber of (b)
A polyethylene terephthalate resin composition comprising 0.1 to 10 parts by weight of an inorganic layered compound of 1 to 4 μm and (c) 0.1 to 10 parts by weight of a lubricant, and a molded article comprising the same. .

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. The polyethylene terephthalate used in the present invention refers to a high-molecular-weight thermoplastic polyester having an ester bond in a main chain, using terephthalic acid as an acid component and ethylene glycol as a glycol component. Acids, orthophthalic acid, naphthalenedicarboxylic acid, oxalic acid, adipic acid, 1,4-cyclohexanedicarboxylic acid, etc. as glycol components such as propylene glycol, 1,4-butanediol, 1,6-hexanediol, , 4-cyclohexanedimethano-
And copolymerized polyethylene terephthalate using 20 mol% or less of bisphenol A or the like.

The polyethylene terephthalate resin of the present invention has an intrinsic viscosity of 0.5 to 0.8 dl / g, a polyethylene terephthalate content of 60 to 95% by weight, and an intrinsic viscosity of 0.85 to 0.8 dl / g.
1.45 dl / g polyethylene terephthalate 5-4
0% by weight. The former intrinsic viscosity 0.5
0.8 dl / g polyethylene terephthalate is 60
When the amount is less than 5% by weight, the fluidity during injection molding is impaired, and when the latter is less than 5% by weight, the polyethylene terephthalate having an intrinsic viscosity of 0.85 to 1.45 dl / g is unsuitable because the fatigue resistance is impaired. In addition, the intrinsic viscosity is 0.85 to 1.45 d.
It is convenient to produce polyethylene terephthalate of 1 / g by solid-phase polymerization of polyethylene terephthalate having an intrinsic viscosity as low as 0.5 to 0.8 dl / g, and it is also preferable to obtain the performance of the present invention. On the other hand, as an unfavorable production example, there is a method in which a polyfunctional (acid anhydride, epoxy compound, etc.) compound is melt-mixed to increase the viscosity, thereby impairing the fluidity during injection molding of the present invention.

[0010] The glass fiber (a) used in the present invention is not particularly limited as long as it is generally used for resin reinforcement, and can be selected from roving, chopped strands, and the like. Surface-treated with agents and sizing agents. Preferred coupling agents include silane coupling agents such as epoxysilane and aminosilane, titanate coupling agents, and zircoaluminate coupling agents. Preferred sizing agents include those containing bisphenol A diglycidyl ether and / or phenol novolak type epoxy compound as a main component. Further, the above-mentioned coupling agent and / or sizing agent may be used in an aqueous emulsion mixed with a urethane resin or a vinyl acetate resin. Also,
The amount of the sizing agent is 0.6 to 1.5% by weight.
If the amount is less than the weight percentage, mechanical properties are impaired.
If it exceeds 5% by weight, it is unsuitable in that the fluidity during molding is impaired. It is not preferable to use a cresol novolak type epoxy compound instead of the above-mentioned phenol novolak type epoxy compound, because the color tone of the glass fiber is deteriorated.

The average fiber diameter of the glass fibers is 2 to 20 μm,
It is particularly preferably 5 to 15 μm, and the number average length in the molded product is preferably 0.03 to 1.0 mm, particularly preferably 0.05 to 0.7 mm.

The amount of glass fiber added is 10 to 100 parts by weight, preferably 15 to 80 parts by weight, based on 100 parts by weight of the polyethylene terephthalate resin. If the amount is less than 10 parts by weight, the desired effect is hardly exhibited, and if it exceeds 100 parts by weight, the mechanical properties are impaired, so that it is inappropriate.

The (b) inorganic layered compound used in the present invention comprises:
An inorganic compound in which unit crystal layers are stacked one on top of the other and have a layered crystal structure and have cleavage properties. Specific examples of the inorganic layer compound include kaolinite, talc, smectite,
Examples include silicates such as vermiculite and mica, and phosphates such as zirconium phosphate and titanium phosphate.These inorganic layered compounds may be subjected to a coupling agent treatment or an organic treatment for ion exchange of inorganic ions between layers with organic ions. It may be performed.

The amount of the inorganic layer compound is 0.1 to 10 parts by weight, preferably 0.2 to 7 parts by weight, based on 100 parts by weight of the polyethylene terephthalate resin.
If the amount is less than 1 part by weight, the desired effect is hardly exhibited, and if it exceeds 10 parts by weight, the mechanical properties are impaired, so that it is inappropriate. Also,
The average particle size of the inorganic layered compound is 0.1 to 4 μm, preferably 0.3 to 3 μm, and if it exceeds 4 μm, the mechanical properties are impaired, so that it is inappropriate.

As the lubricant (c) in the present invention, lubricants for plastics are used. For example, metal soaps such as calcium stearate and barium stearate, fatty acid esters, and salts of fatty acid esters (parts of which are salted) Fatty acid amides such as ethylenebisstearamide, polycondensates of ethylenediamine with stearic acid and sebacic acid, or fatty acid amides of polycondensates of phenylenediamine with stearic acid and sebacic acid, polyalkylene wax, acid anhydride Product-modified polyalkylene wax, but is not limited thereto.

The amount of the lubricant to be added is 0.1 to 10 parts by weight, preferably 0.2 to 7 parts by weight, based on 100 parts by weight of the polyethylene terephthalate resin. If the amount is less than 0.1 part by weight, the intended effect is hardly exhibited, and if the amount exceeds 10 parts by weight, the mechanical properties are impaired, which is inappropriate.

The (d) heat-resistant agent used in the present invention includes a heat-resistant agent such as a hindered phenol-based heat-resistant agent, a phosphite-based heat-resistant agent, and a thioether-based heat-resistant agent.
A combined heat-resistant agent of a hindered phenol heat-resistant agent and a phosphite heat-resistant agent is preferably used.

Specific examples of the above hindered phenol-based heat-resistant agent are not limited, but for example, triethylene glycol-bis {3- (3-t-butyl-5)
-Methyl-4-hydroxyphenyl) propionate {1.6-hexanediol-bis- {3- (3
5-di-tert-butyl-4-hydroxyphenyl) propionate {, pentaerythritol-tetrakis} 3-
(3,5-di-t-butyl-4-hydroxyphenyl)
Propionate}, 2,4-bis- (n-octylthio) -6- (4-hydroxy-3,5-di-t-butylanilino) -1,3,5-triazine, 2,2-thio-
Diethylenebis {3- (3,5-di-t-butyl-4-)
Hydroxyphenyl) propionate {octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate}, N, N'-hexamethylenebis (3,5-di-t-butyl-4-) Hydroxy-hydrocinnamide), 3,5-di-t-butyl-4-hydroxy-benzylphosphonate-diethyl ester,
1,3,5-trimethyl-2,4,6-tris (3,5
-Di-t-butyl-4-hydroxybenzyl) benzene and the like are preferably used.

The phosphite-based heat-resistant agent is a phosphite compound represented by the following general formula: (RO) ₃ P (wherein R is a cyclic hydrocarbon group having 2 to 20 carbon atoms or Specific examples thereof include trisalkyl phosphite, tris (alkylaryl) phosphite, bisphenol type phosphite, and pentaerythritol type phosphite.

Specific examples of the thioether-based heat-resistant agent include pentaerythritol tetrakis (dodecyl thiopropionate), pentaerythritol tetrakis (dodecyl thiobutyrate), pentaerythritol tetrakis (dodecyl thioacetate), and pentaerythritol tetrakis (octadecyl). Thioerypionate), pentaerythritol bis (dodecylthiopropionate), pentaerythritol tris (dodecylthiobutyrate) and the like.

The amount of the heat-resistant agent to be added is 0.01 to 100 parts by weight of the polyethylene terephthalate resin.
To 5 parts by weight, preferably 0.02 to 4.5 parts by weight. If the amount is less than 0.01 part by weight, the effect of the heat-resistant agent is hardly exhibited, and if it exceeds 5 parts by weight, the mechanical properties are impaired, which is not preferable.

The polyethylene terephthalate resin composition of the present invention may contain usual additives such as an ultraviolet absorber, a coloring agent containing a dye and a pigment, a nucleating agent and a flame retardant, as long as the object of the present invention is not impaired. One or more kinds can be further contained.

In addition, the polyethylene terephthalate resin composition of the present invention contains, within a range that does not impair the object of the present invention,
A small amount of other thermoplastic resins (eg, polyethylene, acrylic resin, fluororesin, polyamide, polybutylene terephthalate, polycyclohexylene dimethylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polyphenylene sulfide, polyether ether ketone, polyacetal, polycarbonate , Polysulfone, polyphenylene oxide, etc.), thermosetting resins (eg, phenolic resins, melamine resins, polyester resins, silicone resins, epoxy resins, etc.) and soft thermoplastic resins (eg, ethylene / vinyl acetate copolymers, ethylene / ethyl acrylate copolymers). Polymers, polyester elastomers, ethylene / propylene terpolymer, ethylene / butene-1 copolymer, etc.).

In the polyethylene terephthalate resin composition of the present invention, a small amount of other inorganic fillers can be used so long as the object of the present invention is not impaired. The inorganic filler herein means a fibrous, plate-like or particulate filler, such as carbon fiber, silica fiber, potassium titanate whisker, aluminum borate whisker,
Wollastenite, glass beads, glass flakes, fine silica, feldspar powder, shirasu balloon, magnesium hydroxide, aluminum hydroxide, calcium carbonate, magnesium carbonate, calcium sulfate, barium sulfate, calcium oxide, aluminum oxide, titanium oxide, magnesium oxide , Zirconium oxide, aluminum silicate, silicon oxide, aluminum oxide, iron oxide, barium titanate, calcium fluoride, boron nitride, silicon nitride, metal powder, novacurite, dawsonite, terra alba, and carbon black.

Although the method for producing the composition of the present invention is not particularly limited, it is produced using a known melt mixer, that is, a single or twin screw extruder, a Banbury mixer, a kneader, a mixing roll, or the like. Is preferred.

The composition melt-mixed by the above-mentioned melt-mixer is processed into a molded product by a usual method such as injection molding, press molding, sheet molding and blow molding. In particular, the effect can be exhibited. The obtained molded article has excellent mechanical properties, heat resistance, surface appearance, and fatigue resistance, and can be suitably used for various applications such as electric / electronic parts, automobile parts, and machine parts.

[0027]

The present invention will be described in detail with reference to the following examples. All copies in the examples are on a weight basis. The glass fiber, the inorganic layer compound, the lubricant and the heat-resistant agent used in the present invention are shown below.

Glass fiber A-1: bisphenol A diglycidyl ether ("Epicoat 828" made by Yuka Shell), epoxy equivalent 140 g
/ Eq) glass fiber having an average fiber diameter of about 10 μm and treated with about 1% of a sizing agent having as a main component A-2: bisphenol A diglycidyl ether (A
A glass fiber having an average fiber diameter of about 10 μm, which is treated with about 1% of a sizing agent containing phenol novolak type epoxy resin (“Epicoat E152” manufactured by Yuka Shell Co., epoxy equivalent 175 g / eq) as a main component; A-3: Bisphenol A diglycidyl ether (A
Glass fiber having an average fiber diameter of about 10 μm treated with about 0.5% of a sizing agent whose main component is the same as the sizing agent of A-1 to A-3. An aqueous emulsion mixed with a urethane resin is used.

Inorganic layered compound B-1: talc having an average particle size of 2 μm (“Himicron HE5” manufactured by Takehara Chemical Industry) B-2: talc having an average particle size of 5 μm (“Hitron” manufactured by Takehara Chemical Industry)

Lubricant C-1: Calcium stearate (reagent product of Katayama Chemical Industry) C-2: "Hoechst wax-OP" (a lubricant made by Hoechst Japan, in which a part of a fatty acid ester is salted) C-3: " Light Amide WH-255 "(polycondensate composed of ethylenediamine, stearic acid and sebacic acid manufactured by Kyoeisha Chemical) C-4: Mitsui High Wax 1105A" (acid anhydride-modified polyalkylene wax manufactured by Mitsui Petrochemical Industries)

Heat Resistant D-1: "IR-1010" (Hindered Phenol Heat Resistant manufactured by Ciba-Geigy) D-2: "PEP-36" (Phosphite Heat Resistant manufactured by Asahi Denka) D-3: " 1: 1 mixture of IR-1010 "and" PEP-36 "

Epoxy compound E-1: bisphenol A diglycidyl ether (A
Same substance as -1)

Examples 1 to 10, Comparative Examples 1 to 10 Intrinsic viscosities 0.65 dl / g, 0.82 dl / g and 1.25 dl / g (using o-chlorophenol, 25
Measured in ° C. In addition, the intrinsic viscosities of 0.82 dl / g and 1.25
Was produced from 0.65 dl / g polyethylene terephthalate by increasing the viscosity by an ordinary solid phase polymerization method. ) Of polyethylene terephthalate, glass fiber, inorganic layered compound, lubricant and heat-resistant agent at the ratios shown in Tables 1 and 2 by kneading and compounding at 280 ° C. with a vented twin-screw extruder having a diameter of 40 mm, extrusion, cooling, The resultant was cut to obtain pellets of the polyethylene terephthalate resin composition.

The obtained polyethylene terephthalate resin composition was molded using a screw-type injection molding machine at a cylinder temperature of 280 ° C., a mold temperature of 140 ° C., and a molding cycle of 30 minutes.
Test piece and AST for physical property test under molding condition
An M.D671.Type A (4 mm thick) molded product for a bending fatigue test was obtained.

From the obtained test piece for physical property test, A
The mechanical properties were measured according to the STM standard. Further, the obtained molded article for bending fatigue test was subjected to a repeated fatigue tester manufactured by Toyo Seiki Co., Ltd.
The bending stress at the time of 100,000 cycles was determined.

The method of evaluating fluidity during injection molding is to determine the minimum molding pressure at which a test piece for a physical property test is obtained,
The lower the molding lower pressure, the better the fluidity. Also,
Using Toyo Seiki's melt indexer, 280 ° C, 5k
MI value (g / g) for 5 minutes and 15 minutes retention under g load
10 minutes). A material having a larger MI value has a higher fluidity as the number is larger, and a material having a smaller change in the MI value at the time of retention for 5 minutes and 15 minutes is superior in heat resistance.

Further, the bending fatigue molded article was visually observed, and the appearance of the molded article was determined under the following judgment conditions. 〇: The whole molded product has gloss (excellent appearance of molded product). Δ: Part of the molded article has no luster. ×: There is no gloss in the whole molded product.

The results of the above Examples and Comparative Examples are shown in Tables 1 and 2.

[Table 1]

[0039]

[Table 2]

As is clear from the comparison between the examples shown in Table 1 and the comparative examples shown in Table 2, the polyethylene terephthalate resin composition of the present invention and the molded article comprising the same have excellent mechanical properties, injection moldability and surface appearance. Excellent and excellent fatigue resistance. In addition, as in Examples 8 to 10, a polyethylene terephthalate resin composition having heat resistance and a molded article made thereof were also obtained.

[0041]

The polyethylene terephthalate resin composition according to the present invention and the molded article comprising the same have excellent mechanical properties,
Excellent injection moldability, surface appearance, and excellent fatigue resistance. Further, a polyethylene terephthalate resin composition having heat resistance and a molded article made thereof can also be obtained. Therefore, it can be suitably used for various applications such as electric / electronic parts, automobile parts, and mechanical parts. It is also effective when the obtained molded product is used for a component exhibiting a function to be combined with other components, for example, various components such as a component for an automobile brake booster, a cap, a lever or a component for a switch. It is useful for applications.

Continued on the front page (51) Int.Cl. ⁶ Identification code FI C08K 5/13 C08K 5/13 5/20 5/20 7/14 7/14 9/08 9/08 // (C08L 67/02 91: 06)

Claims (11)

[Claims] 1. A polyethylene terephthalate comprising 60 to 95% by weight of polyethylene terephthalate having an intrinsic viscosity of 0.5 to 0.8 dl / g and 5 to 40% by weight of polyethylene terephthalate having an intrinsic viscosity of 0.85 to 1.45 dl / g. (A) 0.6 to 1.5 with respect to 100 parts by weight of the resin.
Glass fiber 10 to 100% by weight with sizing agent attached
Parts by weight, (b) 0.1 to 10 parts by weight of an inorganic stratiform compound having an average particle diameter of 0.1 to 4 μm, and (c) 0.1 to 10 parts by weight of a lubricant.
A polyethylene terephthalate resin composition containing parts by weight. 2. The sizing agent attached to the glass fiber (a) is a sizing agent containing an epoxy compound as a main component.
The polyethylene terephthalate resin composition according to the above. 3. The polyethylene terephthalate resin composition according to claim 2, wherein the epoxy compound is a bisphenol A diglycidyl ether and / or a phenol novolak type epoxy compound. 4. The polyethylene terephthalate resin composition according to claim 1, wherein (c) the lubricant is a fatty acid ester and / or a salt thereof. 5. The polyethylene terephthalate resin composition according to claim 1, wherein (c) the lubricant is a fatty acid amide. 6. The polyethylene terephthalate resin composition according to claim 1, wherein (c) the lubricant is a polyalkylene wax and / or an acid anhydride-modified polyalkylene wax. 7. The method according to claim 1, wherein the polyethylene terephthalate having an intrinsic viscosity of 0.85 to 1.45 dl / g is a polyethylene terephthalate whose viscosity is increased by a solid phase polymerization method.
The polyethylene terephthalate resin composition according to the above. 8. The polyethylene terephthalate resin composition according to claim 1, further comprising (d) 0.01 to 5 parts by weight of a heat-resistant agent. 9. The polyethylene terephthalate resin composition according to claim 8, wherein (d) the heat-resistant agent is a hindered phenol-based stabilizer and / or a phosphite-based stabilizer. 10. A molded article comprising the polyethylene terephthalate resin composition according to claim 1. 11. The molded product according to claim 10, which is a component for a vehicle brake booster, a cap, a lever, or a switch.