JP3526077B2 - Polyester resin composition and molded article thereof - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyester resin composition composed of a polyethylene naphthalate resin and a polycarbonate resin, and is particularly used as a door handle for automobile doors and buildings.

[0002]

2. Description of the Related Art Conventional resins used for door handles are polycarbonate resin, mineral-reinforced polyamide resin, polyacetal resin, alloy resin of polycarbonate resin and polyethylene terephthalate resin, polycarbonate resin and ABS resin in terms of appearance, rigidity and feel. Alloy resin was mainly used.

However, each of these resins has the following characteristics, and any of them has a problem in being used as a door handle molded product.

That is, although the polycarbonate resin has a high glass transition temperature and excellent rigidity at high temperatures, it may have low chemical resistance and cause stress cracking. Polyacetal resin has poor weather resistance and is unsatisfactory for door handles for outdoor applications. The alloy resin of polycarbonate resin and polyethylene terephthalate resin has improved stress cracking property, but the alloy of polyethylene terephthalate resin reduces the rigidity at high temperature. In order to compensate for this, glass fibers are further compounded and used in high temperature applications, but compounding glass fibers lowers the surface smoothness and impairs the appearance. Polycarbonate resin and ABS resin alloy resin are used as plating because of insufficient stress cracking resistance and weather resistance, but they cannot be used for general-purpose painting or sown handle. Mineral reinforced polyamide resin is inferior in surface appearance due to dimensional change due to water absorption and sink marks in thick parts.

As described above, the conventional materials used for door handles have advantages and disadvantages, and it has been desired to develop a material satisfying all of rigidity, appearance and chemical resistance.

[0006]

SUMMARY OF THE INVENTION The present invention was devised to solve the problems of the prior art,
It is an object of the present invention to provide a polyester resin composition which is excellent in rigidity, appearance and chemical resistance and has a degree of freedom in design, and a door handle formed by molding the same.

[0007]

Means for Solving the Problems As a result of various studies by the present inventors in order to achieve the above-mentioned object, a resin composition obtained by blending a polyethylene naphthalate resin, a polycarbonate resin and an elastomer resin in a specific ratio was obtained. The present invention has been completed by finding that it is excellent as a door handle molded product satisfying all of rigidity, appearance and chemical resistance.

That is, the present invention comprises 10 to 90 parts by weight of polyethylene naphthalate resin and 90 to 1 of polycarbonate resin.
It is a polyester resin composition containing 0 part by weight and a composition comprising 0 to 30 parts by weight of an elastomer resin.

The polyethylene naphthalate resin used in the present invention includes polyethylene naphthalate resin, acid components such as terephthalic acid, isophthalic acid, adipic acid, sebacic acid, propylene glycol, butylene glycol, diethylene glycol, neopentyl glycol,
Examples thereof include those obtained by copolymerizing one or more selected from glycol components such as cyclohexanedimethanol, polyethylene glycol and polytetramethylene glycol at a ratio of 30 mol% or less.

In the present invention, the molecular weight of the polyethylene naphthalate resin is not particularly limited, but it is preferable that the intrinsic viscosity number determined by measuring at 30 ° C. with a phenol / tetrachloroethane mixed solvent (6/4 weight ratio) is 0. Four
The above polyethylene naphthalate resin is used. If the intrinsic viscosity is less than 0.4, the strength of the door handle is reduced, which is not preferable.

The polycarbonate resin used in the present invention is produced by a phosgene method or a transesterification method using bisphenol as a main raw material. The raw material bisphenol includes 2,2-bis (4-hydroxyphenyl) -propane (commonly called bisphenol A), 1,2
Examples thereof include 1'-bis (4-hydroxyphenyl) -cyclohexane (commonly called bisphenol Z), 4,4-dioxydiphenylalkane and the like. Also, 4,4'-dihydroxydiphenyl sulfone or 4,4'-dihydroxyphenyl ether can be copolymerized. Further, two or more kinds of polycarbonate may be mixed and used. From the viewpoint of fluidity and strength during molding, the molecular weight is 1000.
A polycarbonate resin of about 0 to 100,000 is preferable.

The weight ratio of polyethylene naphthalate resin to polycarbonate resin is 10:90 to 90: 1.
It is 0, preferably 25:75 to 90:10, and more preferably 60:40 to 30:70. If the proportion of polyethylene naphthalate resin is lower than this range, the effect of preventing stress cracking resistance against chemicals is insufficient, and if it is higher than this range, the impact resistance decreases, which is not preferable.

The elastomer resin to be blended in the present invention as required includes a graft copolymer of a vinyl monomer of a conjugated diene polymer or a methacrylic acid ester polymer, a conjugated diene polymer and a vinyl monomer. Block copolymers and hydrogenated products thereof, ethylene-α-olefin copolymers, polyether polyester elastomers, polyester polyester elastomers and unsaturated acids and unsaturated anhydrides, and monomers having vinyl groups and glycidyl groups. A modified product obtained by graft reaction or copolymerization is used.

Examples of the conjugated diene include butadiene and isoprene, and examples of the methacrylic acid ester include ethyl methacrylate and butyl methacrylate. Further, as the vinyl-based monomer, methacrylic acid ester, styrene, acrylonitrile and the like are preferable. Ethylene-α
Examples of the α-olefin of the olefin copolymer include propylene, butylene, pentene and the like. The modified product can be obtained by copolymerizing monomers such as maleic anhydride, methacrylic acid and glycidyl methacrylate, or by reacting an organic peroxide with these monomers by melt-kneading and grafting. More specifically, an epoxy modified product of an ethylene propylene copolymer, an epoxy modified product of a hydrogenated styrene butadiene block copolymer, a methyl methacrylate / methacrylic acid graft copolymer of a butadiene polymer, and a butadiene / butyl acrylate polymer Examples include methyl methacrylate graft copolymers, polytetramethylene glycol polybutylene terephthalate block copolymers, polylactone polybutylene terephthalate block copolymers, and the like.

The polyester resin composition containing the above elastomer resin is used for a door handle which is required to have a particularly high impact resistance. In the present invention, the elastomer resin is arbitrarily blended up to a ratio of 30 parts by weight with respect to a total of 100 parts by weight of the polyethylene naphthalate resin and the polycarbonate resin. If the weight ratio of the elastomer resin exceeds the above range, the rigidity at high temperature is lowered and the deformation during coating is not preferable.

Although it is not clear why the alloy resin of polyethylene naphthalate resin and polycarbonate resin is suitable for the purpose of the present invention and useful as a door handle, polyethylene naphthalate resin has a high glass transition temperature of 115 ° C. Alloy resin also has a high glass transition temperature, is excellent in high-temperature rigidity, and since the crystallization rate is slow despite being a crystalline resin originally,
It is considered that the ordinary molded product is obtained in an amorphous state, and thus it has no sink mark and an excellent appearance, and that the polyethylene naphthalate resin prevents the stress cracking property of the polycarbonate resin.

The polyester resin composition of the present invention further comprises talc, wollastonite, calcium carbonate, clay, whiskers, glass fiber, carbon fiber and other reinforcing materials, antioxidants, and ultraviolet absorbers, depending on the purpose and application. Additives such as a plasticizer, a lubricant, an antistatic agent, a release agent, and a colorant can also be added.

The method for producing a door handle formed by molding the polyester resin composition of the present invention is not particularly limited and may be any method. For example, there may be mentioned a method in which pellets obtained by melt-kneading in an extruder or a kneader are injection-molded into a door handle molding die in the same manner as usual thermoplastic polyester molding. No special molding conditions are required to mold the door handle of the present invention. In the manufacture of door handles, a pigment such as carbon black is added to the composition of the present invention for coloring, or a molded product is used for coating in many cases.

The present invention will be specifically described with reference to the following examples, but the present invention is not limited thereto.
Parts and% in the examples are by weight.

The physical properties of Examples and Comparative Examples were measured by the following methods. (1) Flexural strength: ASTM D790 (2) Flexural modulus: ASTM D790 (3) Deflection temperature under load: ASTM D648 4.6k
g / cm ² load measurement (4) Gasoline resistance: Immersed in gasoline for 24 hours under 0.5% bending strain and observed for cracks. The observation result of the presence or absence of cracks is displayed as follows. ◯: No crack, ×: Crack (5) Appearance: 150 mm × 70 mm × 3 mm
Was molded, and its surface appearance was observed and classified into 5 stages as shown below. Good 5>4>3> 2
> 1 bad

Examples 1 to 10 and Comparative Examples 1 to 10 Each of the preblends shown in Tables 1 and 2 was fed to the hopper of a 30φ twin-screw extruder whose temperature was controlled at 280 ° C., and the screw was rotated. Each compound pellet was obtained by melt-kneading at several 60 RPM. 120 ° C for these
After preliminary drying for 5 hours, the cylinder temperature was adjusted to 280 ° C. and the mold temperature was adjusted to 100 ° C., and each test piece was injection molded and evaluated. The measurement results of those physical properties are shown in Table 1 and Table 2.
Are also shown.

[0022]

[Table 1]

[0023]

[Table 2]

As is clear from the measurement results of Tables 1 and 2, the polyester resin composition of the present invention (Examples 1 to 1)
Bending strength and flexural modulus (20,000 kg)
/ Cm ² or more), deflection temperature under load (110 ° C. or more), gasoline resistance, and appearance are all excellent, while polyester resin compositions outside the scope of the present invention (Comparative Examples 1 to 10) The molded product did not give satisfactory results in any of the physical properties.

[0025]

As described above, the polyester resin composition of the present invention is excellent in rigidity, appearance, and chemical resistance, and has a degree of freedom in design, so that it is highly useful as a molded product of a door handle of an automobile or a building. It has the effect of satisfying the requirements.

Front page continuation (58) Fields surveyed (Int.Cl. ⁷ , DB name) C08L 67/00-67/02 C08L 69/00

Claims (4)

(57) [Claims] 1. A polyethylene naphthalate resin 10-9.
A polyester resin composition comprising 0 part by weight, 90 to 10 parts by weight of a polycarbonate resin, and 0 to 30 parts by weight of an elastomer resin. 2. The polyester resin composition according to claim 1, wherein the elastomer resin is 1 to 30 parts by weight. 3. The elastomer resin is a graft copolymer of a vinyl monomer of a conjugated diene polymer or a methacrylic acid ester polymer, a block copolymer of a conjugated diene polymer and a vinyl monomer, or hydrogenation thereof. Thing, ethylene
1 selected from an α-olefin copolymer, a polyether polyester elastomer, a polyester polyester elastomer and a modified product obtained by graft-reacting or copolymerizing an unsaturated acid or an unsaturated anhydride with a monomer having a vinyl group and a glycidyl group. The polyester resin composition according to claim 1, which comprises one or more kinds. 4. A door handle formed by molding the polyester resin composition according to claim 1.