JPH06107917A - Resin composition - Google Patents

Abstract

PURPOSE:To provide a polybutylene 2,6-naphthalene dicarboxylate excellent in light resistance. CONSTITUTION:The resin composition is obtained by adding 0.5-10wt.% of titanium oxide to polybutylene 2,6-naphthalene dicarboxylate. The resin composition has good light resistance, and can especially prevent its UV light deterioration.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to polybutylene-2,6-
It relates to improvement of light resistance of naphthalene dicarboxylate (hereinafter abbreviated as PBN or polybutylene naphthalate).

[0002]

2. Description of the Related Art Polybutylene naphthalate is a resin having excellent heat resistance and mechanical strength and is said to have a wide range of fields of use such as electric / electronic parts, automobile parts or mechanical parts.

However, PBN is not always excellent in light resistance. Since almost no research and development has been carried out in the prior art, there is no accumulated technology regarding PBN and no means for improving light resistance has been known.

According to the research conducted by the present inventors, PBN is light,
It has been found that there is a tendency for discoloration to occur particularly when exposed to ultraviolet light. Then, as a result of earnestly researching in order to solve this problem, it was found that PBN containing a specific amount of titanium oxide has unexpectedly good resistance to ultraviolet ray deterioration, and arrived at the present invention.

[0005]

According to the present invention, titanium oxide is added to PBN in an amount of 0.5 to 10% by weight.

The present invention will be described in detail below.

The polybutylene naphthalate used in the present invention comprises naphthalene dicarboxylic acid, preferably naphthalene-2,6-dicarboxylic acid as a main acid component, and 1,4-
Polyester containing butanediol as a main glycol component, that is, all or most of repeating units (usually 90
A polyester in which butylene naphthalate is used in an amount of not less than mol%, preferably not less than 95 mol%.

Further, this polyester can be copolymerized with the following components as long as the physical properties are not impaired. That is, as the acid component, an aromatic dicarboxylic acid other than naphthalenedicarboxylic acid, for example, phthalic acid, isophthalic acid, terephthalic acid, diphenyldicarboxylic acid, diphenyletherdicarboxylic acid, diphenoxyethanedicarboxylic acid, diphenylmethanedicarboxylic acid, diphenylketonedicarboxylic acid, Examples thereof include diphenyl sulfide dicarboxylic acid, diphenyl sulfone dicarboxylic acid, aliphatic dicarboxylic acid such as succinic acid, adipic acid, sebacic acid, alicyclic dicarboxylic acid such as cyclohexanedicarboxylic acid, tetralindicarboxylic acid and decalindicarboxylic acid.

As the glycol component, ethylene glycol, propylene glycol, trimethylene glycol,
Pentamethylene glycol, hexamethylene glycol, octamethylene glycol, neopentyl glycol, cyclohexanedimethanol, xylylene glycol, diethylene glycol, polyethylene glycol,
Examples include bisphenol A, catechol, resorcinol, hydroquinone, dihydroxydiphenyl, dihydroxydiphenyl ether, dihydroxydiphenylmethane, dihydroxydiphenylketone, dihydroxydiphenylsulfide, dihydroxydiphenylsulfone and the like.

Examples of the oxycarboxylic acid component include oxybenzoic acid, hydroxynaphthoic acid, hydroxydiphenylcarboxylic acid and ω-hydroxycaproic acid.

Further, trifunctional or higher functional compounds such as glycerin, trimethylpropane, pentaerythritol, trimellitic acid and pyromellitic acid may be copolymerized as long as the polyester does not substantially lose the molding performance.

Such a polyester can be obtained by polycondensing naphthalenedicarboxylic acid and / or a functional derivative thereof and butylene glycol and / or a functional derivative thereof by a conventionally known method for producing an aromatic polyester.

The titanium oxide used in the present invention may be of any type such as rutile type or anatase type, and the average particle size is not particularly limited as long as it does not adversely affect the appearance of the obtained molded product. Regarding the method of blending titanium oxide with PBN, for example, a method of feeding PBN and titanium oxide to an extruder such as a single-screw or twin-screw extruder and kneading,
There is a method of adding titanium oxide before N-polycondensation or during polymerization.

The amount of titanium oxide added is 0.5 to 10 parts by weight based on 100 parts by weight of PBN. If it is less than 0.5 part by weight, the effect of suppressing discoloration is small. On the other hand, if it exceeds 10 parts by weight, the tensile strength is lowered and it becomes unsuitable for the purpose of use as engineering plastics.

In the PBN of the present invention, in addition to titanium oxide,
Various additives depending on the purpose of use, for example, reinforcing agents having various shapes such as fibrous, plate-like, powdery, etc., stabilizers, colorants, release agents, antistatic agents, crystallization accelerators, crystal nucleating agents. , A filler, an impact modifier, a flame retardant, a flame retardant aid, etc. can be added, and an ultraviolet absorber is particularly preferable because it enhances the effect of adding titanium oxide.

The injection molding method is the most preferable method for obtaining a molded product from the composition of PBN and titanium oxide of the present invention, but in addition to this, an extrusion molding method, a compression molding method, a transfer molding method, a blow molding method and the like. In addition to the known molding methods, it is also possible to subject the molded products obtained by these molding methods to secondary processing such as cutting, welding, bonding, joining, bending, plating vapor deposition, printing and painting. is there.

[0017]

EXAMPLES The present invention will be supplemented with examples below.

The main characteristic measuring methods are as follows.

Light resistance test A resin test piece was mounted on a Sunshine Super Long Life Weather Meter (WEL-SUN-HCH) manufactured by Suga Test Instruments Co., Ltd. and irradiated with ultraviolet rays by carbon arc for 500 hours.

Next, the hue of the test piece was measured for yellowness (YI) with a color difference meter (CR-100) manufactured by Minolta Co., Ltd. did.

Preparation of Resin The resin compositions used in Examples and Comparative Examples were obtained as follows.

PBN having an intrinsic viscosity of 0.85 measured in ortho-chlorophenol and rutile-type titanium oxide having an average particle size of 0.25 μm were fed to a single-screw extruder in predetermined amounts and melt-kneaded. A pelletized resin composition was obtained.

A pellet having a smooth surface (50 mm diameter × 2) was obtained from the pellet of the resin composition thus obtained by using an injection molding machine.
(mm thickness) was molded and used as a sample for an ultraviolet irradiation test.

The composition ratio of the resin composition and the result of the ultraviolet irradiation test are summarized in Table 1.

[0025]

[Table 1]

The value of YI is JIS Z8701-195.
Formula based on the X, Y, and Z values defined in 8, YI = 100
It was calculated using (1.28X-1.06Z) / Y.

Claims (1)

[Claims] 1. A resin composition comprising 0.5 to 10 parts by weight of titanium oxide mixed with 100 parts by weight of polybutylene naphthalate.