JPH0689225B2 - Polyester composition - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a linear polyester composition having improved light resistance, and more specifically to a specific hindered phenol compound and a specific alkylidene bis (benzotriazolyl). The present invention relates to a linear polyester composition containing a (phenolic) compound and not containing a hindered amine light stabilizer and having significantly improved light resistance.

[Problems to be Solved by Prior Art and Invention]

Polyalkylene terephthalates are used in various applications as materials for fibers, films and molded articles.

In particular, polyethylene terephthalate has extremely excellent performance as a material for fibers and films, and has become a main product in the textile industry. Further, recently, a combination of polyethylene terephthalate or polybutylene terephthalate and glass fiber has come to be used as an engineering plastic as a molding resin material because of its extremely high heat distortion temperature and mechanical properties.

However, these linear polyesters do not have sufficient light resistance and, for example, in outdoor use or indoor use under fluorescent lamp irradiation, their use was significantly limited due to discoloration of the product or reduction in strength.

For this reason, various light stabilizers have been conventionally used singly or in combination of several kinds, and in particular, a benzotriazole-based ultraviolet absorber is generally used because its effect is relatively large, but the effect is not yet obtained. It was inadequate and needed further improvement.

[Means for solving problems]

The present inventors have conducted diligent studies in view of the present situation, and as a result, have found that 3,5-dialkyl-4-hydroxyphenylpropionic acid ester compounds and alkylidene bis (benzotriazolyl) represented by the following general formula (I): Luphenol)
It has been found that the linear polyester can be stabilized for a long period of time by using the compound in combination.

That is, the present invention, for 100 parts by weight of linear polyester,
3,5-dialkyl-4-hydroxyphenylpropionic acid ester compound 0.001 to 5 parts by weight and a compound represented by the following general formula (I) 0.001 to 5 parts by weight, containing a hindered amine light stabilizer A linear polyester composition having improved light resistance is provided.

(In the formula, R represents an alkyl group or an aralkyl group.) Hereinafter, the linear polyester composition of the present invention will be described in detail.

In the compound represented by the general formula (I) used in the present invention, the aalkyl group represented by R is methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, sec-butyl, amyl, 3rd Amil,
Hexyl, heptyl, octyl, isooctyl, 2-ethylhexyl, 1,1,3,3-tetramethylbutyl, nonyl, decyl, isodecyl, dodecyl, octadecyl and the like, and the aralkyl group includes benzyl, α-methylbenzyl, Examples include cumyl.

Therefore, the alkylidene bis (benzotriazolylphenol) represented by the general formula (I) used in the present invention is used.
Examples of the compound include the following compounds.

No.1 2,2'-methylenebis (4-methyl-6-benzotriazolylphenol) No.2 2,2'-methylenebis [4- (1,1,3,3-tetramethylbutyl) -6- Benzotriazolylphenol] No.3 2,2'-methylenebis (4-cumyl-6-benzotriazolylphenol) The addition amount of the compound represented by the general formula (I) is 100 parts by weight of linear polyester. On the other hand, it is 0.001 to 5 parts by weight, preferably 0.01 to 3 parts by weight.

The linear polyester stabilized in the present invention is a polyalkylene terephthalate obtained by a polycondensation reaction of terephthalic acid or a dialkyl ester thereof and an aliphatic glycol, or a copolymer mainly composed of polyalkylene terephthalate. Examples thereof include polyethylene terephthalate and polybutylene terephthalate.

Examples of the aliphatic glycols include ethylene glycol, propylene glycol, tetramethylene glycol, hexamethylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, cyclohexanediol, cyclohexanedimethanol, and benzenedimethanol. Other diols or polyhydric alcohols together with aliphatic glycols, eg, 30% by weight or less of 2,2-bis (4-hydroxyphenyl) based on aliphatic glycols
Propane (bisphenol A), 2,2-bis (4-hydroxy-3,5-dibromophenyl) propane, 2,2-bis (4-
Hydroxyethoxyphenyl) propane, 2,2-bis (4-
Hydroxyethoxy-3,5-dibromophenyl) propane, glycerin, pentaerythritol and the like may be mixed and used.

In addition to terephthalic acid or its dialkyl ester, other dibasic acid, polybasic acid or their alkyl ester, such as terephthalic acid or its dialkyl ester, may be contained in an amount of 30% by weight or less of phthalic acid, isophthalic acid, naphthalene dicarboxylic acid or diphenyl dicarboxylic acid. Acids, adipic acid, sebacic acid, trimesic acid, trimellitic acid, their alkyl esters and the like may be mixed.

Examples of the 3,5-dialkyl-4-hydroxyphenylpropionic acid ester compound used in the present invention include stearyl-β- (3,5-ditert-butyl-4-hydroxyphenyl) propionate and thiodiethylenebis [β. -(3,5-di-tert-butyl-4-hydroxyphenyl) propionate], hexamethylenebis [β- (3,
5-di-tert-butyl-4-hydroxyphenyl) propionate], 3,6-dioxaoctylenebis [β- (3-
Methyl-5-tert-butyl-4-hydroxyphenyl) propionate], 1,3,5-tris [β- (3,5-di-tert-butyl-4-hydroxyphenyl) propionyloxyethyl] isocyanurate, tetrakis [ Methylene-β-
(3,5-di-tert-butyl-4-hydroxyphenyl) propionate] methane and the like.

The amount of these phenolic antioxidants added is 0.001 to 3 parts by weight, preferably 100 to 3 parts by weight of the linear polyester.
0.005 to 1 part by weight.

In addition, an organic phosphite compound, a flame retardant, a coloring agent, a lubricant, a filler and the like can be used together in the composition of the present invention, if necessary.

Hereinafter, the present invention will be described in more detail with reference to Examples.

Example 1 100 parts of polybutylene terephthalate having an intrinsic viscosity of 1.2, 0.1 part of pentaerythritol tetra (3,5-ditert-butyl-4-hydroxyphenylpropionate) and 0.5 part of the light stabilizer shown in Table 1 were mixed. , Using extruder 260
The mixture was melt-kneaded at ℃ and extruded into pellets.

The pellets were injection-molded using an injection molding machine and a test piece molding die defined by ASTM at a resin temperature of 265 ° C., a die temperature of 90 ° C., an injection time of 10 seconds, and a cooling time of 30 seconds.

The obtained test piece was used for irradiation in a weatherometer for 3000 hours, and the tensile strength after irradiation was measured. The residual ratio of the tensile strength was calculated from the ratio of the tensile strength before irradiation to the light resistance.

The results are shown in Table 1.

Example 2 100 parts of polyethylene terephthalate having an intrinsic viscosity of 0.72, 0.1 part of pentaerythritol tetra (3,5-ditert-butyl-4-hydroxyphenylpropionate) and 1 part of the light stabilizer described in Table 1 were mixed, Melt extrusion was performed at 300 ° C, and a sheet was prepared on a quenching drum at 45 ° C. next
It was stretched at a draw ratio of 3.5 times in the machine direction at a temperature of 90 ° C., stretched axially at a rate of 3.6 times at 100 ° C., and then heat set at 200 ° C. for 30 seconds to prepare a biaxially stretched film having a thickness of 0.125 mm.

The polyester film deteriorates due to light irradiation,
Since the surface condition deteriorates and haze increases, the obtained film is put in a weatherometer, the change with time of the haze value is measured, and the time until the haze value reaches 50% is determined by extrapolation. , Lightfast.

The results are shown in Table 2.

Claims (1)

[Claims] 1. 1,5-weight parts per 100 parts by weight of linear polyester
Dialkyl-4-hydroxyphenylpropionic acid ester compound 0.001 to 5 parts by weight and 0.001 to 5 parts by weight of a compound represented by the following general formula (I) are contained, and a hindered amine light stabilizer-free light fastness Improved linear polyester composition. (In the formula, R represents an alkyl group or an aralkyl group.)