JPS6138213B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a stabilized polyphenylene oxide resin composition, and in particular to a stabilizer that exhibits an excellent effect in preventing polyphenylene oxide from deteriorating under various effects of heat and atmospheric conditions. The present invention relates to a blended polyphenylene oxide resin composition. Polyphenylene oxides are susceptible to oxidative deterioration due to heat, atmospheric oxygen, ozone, and various other influences, and the aging process causes a decrease in mechanical strength.
This results in a decrease in molecular weight, loss of electrical insulation, and often a change in color. When putting polyphenylene oxides into practical use, in order to prevent such deterioration, for example, acid anhydrides, 2-mercaptobenzimidazoles, hydrazine derivatives, boric acid derivatives, phenol compounds, phosphite compounds, etc. are used. Although methods have been proposed, not only are they not always sufficiently effective, but they often cause staining and discoloration of the appearance. The object of the present invention is to stabilize polyphenylene oxides against oxygen-induced deterioration under the action of light and heat without the drawbacks mentioned above. As a result of repeated research, the present inventors discovered that Tris(2.
It was revealed for the first time that by blending 4-di-tert-butylphenyl) phosphite, a polyphenylene oxide resin composition that is stabilized against the effects of heat, light, oxygen, etc. can be obtained. The amount of the phosphite compound added is 0.01 to 5 parts by weight, particularly preferably 0.05 to 3 parts by weight, per 100 parts by weight of the polyphenylene oxide resin. Various additives commonly used for polyphenylene oxide resins can be added to the composition of the present invention. These other additives include 2,6-di-tert-butyl-p-cresol, 4,4'-n-butylidenebis (2-tert-butyl-5-methylphenol), 1,1,3- Tris(2-methyl-4-hydroxy-5-tert-butylphenyl)butane, tris(3,5-di-tert-butyl-4-hydroxybenzyl)isocyanurate, 1,3,5-tris(3,5- di-tert-butyl-4-hydroxybenzyl)-2,4,6-trimethylbenzene, β
-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid and monohydric to tetrahydric alcohol {e.g. methanol, decanol, stearyl alcohol, ethylene glycol, thiodiethylene glycol, 1,6-hexanediol, tris (2-hydroxyethyl)isocyanurate, phenolic antioxidants such as esters with pentaerythritol}, organic sulfides such as dilauryl-, dimyristyl- or distearylthiodipropionate, pentaerythritol tetra (lauryl mercaptopropionate) antioxidants, acid anhydrides such as phthalic anhydride and benzoic anhydride, Ca,
Carboxylate salts such as Mg, Ba, and Zn, hydrazine, hydrazine derivatives such as adipic dihydrazide, boric acid, boric anhydride, boric acid derivatives such as boric ester, organotin compounds, alkanolamines, and amines such as diphenylamine. , 2-hydroxybenzophenones, 2-hydroxyphenylbenzotriazoles, nickel chelate, hindered piperidyl compounds, and other light stabilizers, pigments, dyes, flame retardants, fillers, antistatic agents, antifungal agents, etc. can be given. In the present invention, the stabilized polyphenylene oxide resin has the formula (In the formula, Ra represents a hydrogen atom, an alkyl group, an alkoxy group, a haloalkyl group, or a haloalkoxy group, Rb, Rd, and Re represent the group represented by Ra or a halogen atom, and Rc represents a hydrogen atom or a halogen atom. Polymers produced by oxidative polycondensation of phenols shown in Graft copolymer or polystyrene, styrene copolymer, polycarbonate,
Examples include copolymers obtained by oxidative coupling of the above phenols in the presence of other polymers such as polysulfone, nylon, polyolefin, and rubbery polymers, and blends of the above polymers or copolymers with other polymers mentioned above. It will be done. Hereinafter, the present invention will be explained in more detail with reference to Examples. Example 1 50 parts by weight of poly(2,6-dimethyl-1,4-phenylene oxide) with an intrinsic viscosity of 0.56 dl/g (in chloroform at 25°C), 47.5 parts by weight of polystyrene,
2.5 parts by weight of polycarbonate, 3.0 parts by weight of titanium oxide, and 0.5 parts by weight of a stabilizer were added, thoroughly mixed in a Henschel mixer, pelletized in an extruder, and then injection molded to prepare a test piece. This sample was heated in a gear oven at 125°C for 100 hours, and the elongation and Izod impact value retention were measured. The results are shown in Table-1.

[Table] Example 2 0.3 parts by weight of a stabilizer was blended with 100 parts by weight of poly(2,6-dimethyl-1,4-phenylene oxide) with an intrinsic viscosity of 0.60 dl/g (in chloroform at 25°C), and a sufficient After mixing, the mixture was pressed at 300°C to prepare a test piece. Using this test piece, the temperature was 160℃ in an oxygen stream.
The mixture was heated for 3 hours and the amount of oxygen absorbed was measured. The results are shown in Table-2.

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Claims (1)

[Claims] 1. A stabilized polyphenylene oxide resin composition containing 0.01 to 5 parts by weight of tris(2,4-di-tert-butylphenyl) phosphite to 100 parts by weight of a polyphenylene oxide resin.