JPH0987491A - Resin composition improved in weather resistance and molding for illuminator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a resin composition, having excellent weather resistance and useful as an illuminator hardly causing the discoloration by using a polyester resin, titanium oxide and an epoxy compound in combination. SOLUTION: This resin composition improved in weather resistance is obtained by blending (A) 100 pts.wt. polyester with (B) 1-40 pts.wt. titanium oxide and (C) 0.01-10 pts.wt. epoxy compound which has a polyfunctional epoxy such as a monoepoxy or a diepoxy and comprising a derivative of, e.g. the formula (R is phthalimide, phenyl, phenoxy, benzoyloxy, a cycloalkyl, etc.), and further (D) glass fibers in an amount of 1-150 pts.wt. based on 100 pts.wt. component (A). Furthermore, the component (A) is preferably a polyester containing >=80mol% terephthalic acid (derivative) as an acid component and >=80mol% ethylene glycol and 1,4-butanediol (derivative) as alcohol components or a blended resin of mutual polyesters, preferably polyethylene terephthalate or polybutylene terephthalate.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin composition, and more particularly to a weather resistance improving resin composition suitable for use in a portion to which heat is applied together with ultraviolet rays and visible rays, and a molding for a lighting fixture formed by such a composition. Regarding goods.

[0002]

2. Description of the Related Art Conventionally, polyester has been used for electric and electronic parts, connectors and the like because of its excellent electrical properties, mechanical properties and chemical resistance. In addition, when used for lighting equipment applications, the weather resistance has been improved by adding an organic ultraviolet absorber or by compounding titanium oxide in order to improve the weather resistance. However, the addition of organic UV absorbers is costly and non-persistent, and causes so-called blooming, where additives and other components exude to the surface.

Titanium oxide is inexpensive and exhibits excellent weather resistance, but it needs to be added in a large amount, and if it becomes a certain amount, the effect of improving weather resistance is lost and physical properties deteriorate. Further, it is not sufficient for applications requiring high weather resistance, for example, molded articles for lighting equipment, and a technique for improving weather resistance while maintaining toughness to some extent was expected.

[0004]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned drawbacks of the prior art and provides a resin composition exhibiting excellent weather resistance, and a molded article for a lighting fixture made of such a composition. It is to be.

[0005]

As a result of studies to further improve weather resistance, it was found that weather resistance can be improved by using titanium oxide and an epoxy compound in combination. That is, by using titanium oxide and an epoxy compound in combination, the same weather resistance can be obtained with a small amount of titanium oxide, and as a result, toughness is restored.

Here, the polyester is a polymer or copolymer obtained by a condensation reaction containing an aromatic dicarboxylic acid (or its ester-forming derivative) and a diol (or its ester-forming derivative) as the main components. It is united.

Here, examples of the aromatic dicarboxylic acid include terephthalic acid, isophthalic acid, phthalic acid, 2,6-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid (or its ester-forming derivative). However, it is preferable that 80 mol% or more of terephthalic acid is contained.

The diol component is preferably an aliphatic diol having 2 to 10 carbon atoms, that is, ethylene glycol, propylene glycol, 1,4-butanediol, neopentyl glycol, 1,5-pentanediglycol, 1,6. -Hexanediol, cyclohexanediol, cyclohexanedimethanol, etc., some of which are substituted with long chain glycols having a molecular weight of 400 to 6,000, that is, polyethylene glycol, polytetramethylene glycol, etc., and mixtures thereof. May be.

Examples of the aromatic polyester used in the present invention include polyethylene terephthalate, polybutylene terephthalate, polycyclohexane dimethylene terephthalate, polyethylene-2,6-naphthalate and polybutylene-2,6-naphthalate.

Titanium oxide is a commonly used titanium oxide, which may or may not be surface-treated, but is preferably surface-treated with alumina / silica in view of influence on the resin and weather resistance. . Titanium oxide includes rutile type and anatase type, but is not particularly limited, but rutile type is preferable in consideration of weather resistance.

As the epoxy compound, a commonly used monoepoxy or polyfunctional epoxy is used. The type of epoxy is not particularly limited, but the following formula (Formula 1) can be used as an example.

[0012]

Embedded image (Wherein R is phthalimide, phenyl, phenoxy, benzoyloxy, cycloalkyl, cycloalkyloxy, cycloalkylcarbonyloxy, or a monoepoxy derivative derived from an aliphatic alcohol. Or bis (3,4-epoxycyclohexylmethyl) adipate ,
It is a multifunctional epoxy consisting of vinylcyclohexene japoxide, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexylcarboxylate, bisphenol diglycidyl ether, diglycidyl adduct of carboxylic acid, triglycidyl isocyanurate and a mixture thereof. Particularly preferred is diepoxy.

In the present invention, it can be reinforced with glass fiber (hereinafter abbreviated as GF) or the like. As GF, GF which is generally used is preferably surface-treated. Examples of the surface treatment include aminosilane and epoxysilane, but are not particularly limited. The diameter of GF is also not particularly limited, but those in the range of 6 to 15 μm are preferable.

In the present invention, flame retardancy can be imparted by adding a flame retardant / flame retardant aid. The flame retardant is not particularly limited, but a brominated flame retardant usually used for polyester (for example, brominated polycarbonate (hereinafter also abbreviated as PC), brominated PC oligomer, brominated epoxy, brominated imide, bromine). Acrylate). If necessary, it may be used in combination with a flame retardant auxiliary such as an antimony compound (eg, antimony trioxide, antimony pentoxide, sodium antimonate, etc.).

It is also possible to add a thermoplastic resin (for example, PC, polystyrene, polyphenylene ether, polyamide) as another component.

In addition to GF, carbon fibers, potassium titanate fibers, gypsum fibers, styrene fibers, mica, talc, silica, calcium carbonate, glass beads, glass flakes, clay, warrasnite, titanium oxide and other fibrous and granular materials. It is also possible to add one kind or two or more kinds of inorganic fillers such as powder, plate and the like.

In addition, the composition of the present invention may contain conventional additives such as antioxidants, ultraviolet absorbers, mold release agents, lubricants, and colorants within the range not impairing the object of the present invention. And also other thermoplastics (eg polyethylene, polypropylene, ethylene / propylene copolymers,
Ethylene / propylene / diene terpolymer, ethylene / glycidyl methacrylate copolymer) Addition of ethylene / ethyl acrylate, SEBS, core-shell type rubber (eg, core: butyl acrylate, shell: methyl methacrylate) as a rubber component These additives can be used alone or in combination of two or more.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION Examples of the present invention will be shown below.
The present invention is not limited to these. Examples 1 to 6 The parts shown below in parts by weight shown in Table 1 were thoroughly mixed using a super mixer. Component A: Polybutylene terephthalate (PBT) was used as the polyester component. Val for PBT
ox295 (trademark: manufactured by General Electric Company) was used. Component B: R-680 (trademark: manufactured by Ishihara Sangyo Co., Ltd.) was used as titanium oxide. Component C: As the epoxy compound, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexycarboxylate was used. Component D: GF manufactured by Nippon Electric Glass Co., Ltd. was used as GF. Aminosilane and epoxy are used for the surface treatment. The fiber diameter is 13 μm. Component E: SR-T5000 (trademark: manufactured by Sakamoto Yakuhin Co., Ltd.) was used as the flame retardant. SR-T5000 is a brominated epoxy and is a flame retardant having a molecular weight of about 10,000. Component F: Antimony trioxide was used as the flame retardant aid.

Comparative Examples 1 to 3 PBT was used as a polyester component, and changes in properties due to the presence or absence of the titanium oxide and the epoxy compound were compared.

After blending the formulations shown in Table 1 in both the examples and comparative examples, a 65 mm single screw / 2
Extrusion was carried out at 50 ° C to pelletize. After drying the pellets at 120 ° C. for about 4 hours, a 1/32 ″ flam bar and a 50 * 50 * 3 mm square plate were molded using an 80 ton molding machine.

[0021]

[Table 1] Composition ratio and physical property measurement results

Evaluation of toughness A 1/32 "flam bar was evaluated by breaking energy (F. Energy) by a bending test with a span of 30 mm and a cross head speed of 3.0 mm. The unit is kgf.
-Mm.

Weather resistance test A 50 * 50 * 3 mm square plate was attached to a fluorescent lamp (250 nm / 12
After aging at 0 ℃ for 100 hours, HITA
CHI CA-35 Spectro Photome
The color difference was measured with a ter to evaluate the change in Δb ^* (yellowness).

Moldings for luminaires, such as incandescent luminaires, which have been exposed to visible light, ultraviolet light, and high heat for a long time because they have improved weather resistance as described above.
Suitable for use as fluorescent lamp fixtures, sockets for other discharge lamp fixtures, and other parts.

[0025]

As is clear from the comparison of the measurement results described in Table 1 above, by combining polyester with titanium oxide and an epoxy compound, a resin composition exhibiting even more excellent weather resistance can be obtained. In this case, equivalent weather resistance can be achieved with a small amount of titanium oxide added, and a decrease in toughness can be suppressed. Further, a weather resistance improving resin composition is obtained which can minimize discoloration even when the composition is used for lighting equipment.

Claims (5)

[Claims] 1. A weather resistance improving resin composition comprising 1 to 40 parts by weight of titanium oxide and 0.01 to 10 parts by weight of an epoxy compound based on 100 parts of polyester. 2. The polyester component contains 80 mol% or more of terephthalic acid or a derivative thereof as an acid component, and ethylene glycol 1, 4, as an alcohol component.
The weather resistance improving resin composition according to claim 1, which is a polyester or a blend resin of polyesters containing butanediol or a derivative thereof in an amount of 80 mol% or more. 3. The weather resistance improving resin composition according to claim 1, wherein the polyester component is either polyethylene terephthalate or polybutylene terephthalate. 4. The weather resistance improving resin composition according to claim 1, which contains 1 to 150 parts by weight of glass fiber with respect to the polyester 100. 5. A molded article for a lighting fixture, comprising the weather resistance improving resin composition according to any one of claims 1 to 4.