JPH0576502B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to polyphenylene ether resin compositions. More specifically, the present invention relates to a polyphenylene ether resin composition that has improved light resistance, particularly light resistance to light through glass. Polyphenylene ether resins, especially resins made of polyphenylene ether resins and styrene polymers, have low water absorption;
Although it has good dimensional stability and is well-balanced in heat resistance, mechanical properties, and electrical properties, it has the disadvantage of severe yellowing due to ultraviolet rays. In order to improve this drawback, it is generally known to incorporate compounds such as benzotriazole, cyanoacrylate, and salicylic ester compounds into polyphenylene ether resins as light stabilizers. However, even with the improvements made using these stabilizers, it is difficult to control not only the discoloration that occurs outdoors when exposed to direct sunlight, but also the discoloration that occurs indoors due to sunlight that shines through glass. The current situation is that this color is not suitable for use because it causes noticeable discoloration. On the other hand, polyphenylene ether resins have excellent mechanical properties and flame retardant properties, so demand has increased in recent years especially for use in housings for computers and office equipment. These products used indoors are rarely exposed to sunlight directly, and light passing through window glass poses a problem. Although the amount of light energy in the ultraviolet region is considerably reduced by passing through glass, satisfactory light resistance cannot currently be obtained by methods such as adding the above-mentioned stabilizers. The present inventors have carried out intensive studies aimed at improving the light resistance, particularly the light resistance to light through glass, of polyphenylene ether resins or resins made of polyphenylene ether resins and styrene polymers. The inventors have discovered that light resistance can be significantly improved by combining a heterocyclic hindered amine compound and an epoxy compound with a resin mixture consisting of a polyphenylene ether resin and a styrene polymer, leading to the present invention. That is, the present invention provides a polyphenylene ether resin or a resin mixture comprising this and a styrene polymer.
This is a novel thermoplastic resin composition containing 0.1 to 5.0 parts by weight of each of (a) a heterocyclic hindered amine compound and (b) an epoxy compound in 100 parts by weight. In the resin composition of the present invention, both the polyphenylene ether resin and the styrene polymer have a molecular weight of 30 to 70%.
Preferably, the heterocyclic hindered amine compound and the epoxy compound are mixed in a range of 0.1 to 5 parts by weight based on a total of 100 parts by weight. In the resin composition provided by the present invention, the excellent mechanical properties originally possessed by the resin are not significantly deteriorated, and there is no initial discoloration at all, and the light resistance to light through glass is greatly improved. . This is an excellent property that cannot be achieved using conventional methods. The polyphenylene ether resin used in the resin composition of the present invention is known per se, and has the general formula

[Formula R ₁ , R ₂ , R _{3 and} R ₄ are hydrogen atoms, halogen atoms, alkyl groups, alkoxy groups, haloalkyl groups having at least 2 carbon atoms between the halogen atom and the phenyl ring] A general term for polymers represented by the above general formula The polymer represented by the above may be used alone, or may be a copolymer in which two or more thereof are combined. In a preferred example, R ₁ and R ₂ are alkyl groups having 1 to 4 carbon atoms, and R ₃ and R ₄ are hydrogen atoms or alkyl groups having 1 to 4 carbon atoms. For example, poly(2,6-dimethyl-1,4-phenylene) ether, poly(2,6-diethyl-1,4-phenylene) ether, poly(2-methyl-6-ethyl-
1,4-phenylene) ether, poly(2-methyl-6-propyl-1,4-phenylene) ether, poly(2,6-dipropyl-1,4-phenylene) ether, poly(2-ethyl-6- Examples include propyl-1,4-phenylene) ether. A particularly preferred polyphenylene ether resin is poly(2,6-dimethyl-1,4-phenylene) ether. Examples of the polyphenylene ether copolymer include copolymers containing a portion of alkyl trisubstituted phenol such as 2,3,6-trimethylphenol in the polyphenylene ether repeating unit. It may also be a copolymer in which a styrene compound is grafted onto these polyphenylene ethers. The styrene-based compound grafted polyphenylene ether referred to in the present invention is a copolymer obtained by graft polymerizing a styrene-based compound such as styrene, α-methylstyrene, vinyltoluene chlorostyrene, etc. to the above-mentioned polyphenylene ether. It is. The styrenic polymer used in the present invention is also known per se, and has the general formula

[Chemical formula] (In the formula, R is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, Z is a halogen atom or an alkyl group having 1 to 4 carbon atoms, and P is 0 to 5
The polymer must contain at least 25% by weight of repeating structural units derived from a vinyl aromatic compound represented by (an integer of ). Examples of such styrenic polymers include homopolymers of styrene or derivatives thereof, and natural or synthetic elastomers such as polybutadiene, polyisoprene, butyl rubber, EPDM, ethylene-propylene copolymers, natural rubber, and epichlorohydrin. Mixtures of substances or styrenic polymers modified with these, as well as styrene-containing copolymers, such as styrene-acrylonitrile copolymers (BAN), styrene-butadiene copolymers, styrene-maleic anhydride copolymers , styrene-acrylonitrile-butadiene copolymer (ABS). Preferred styrenic polymers for the present invention are homopolystyrene and rubber reinforced polystyrene. The mixing ratio of the styrene polymer to the polyphenylene ether resin is preferably within a range that does not impair the excellent properties of the polyphenylene ether resin. ~70 parts by weight are preferred. The heterocyclic hindered amine compound used in the present invention consists of a 6-membered heterocycle containing a hindered amine nitrogen atom and optionally a different atom, preferably nitrogen or oxygen. For example, di-(2,2,6,6-tetramethyl-4-piperidyl)sebacate, 4-benzoyloxy-2,2,6,6-tetramethylpiperidine, succinic acid and N-(2-hydroxyethyl) −
Condensation product with 2,2,6,6-tetramethyl-4-hydroxypiperidine, 1234-tetra(2,2,
6,6-tetramethyl-4-piperidyl)-butanetetracarboxylate, 1,4-di-(2,
2,6,6-tetramethyl-4-piperidyl)-
2,3-butanedione, tris-(2,2,6,
6-tetramethyl-4-piperidyl) trimellitate, 1,2,2,6,6-pentamethyl-4-
Piperidyl stearate, 1,2,2,6,6-
Pentamethyl-4-piperidyl-n-octoate, bis-(1,2,2,6,6-pentamethyl-4-piperidyl) sebacate, tris-(2,
2,6,6-tetramethyl-4-piperidyl)-
Nitrile acetate, 4-hydroxy-1,2,
Examples include 2,6,6-pentamethylpiperidine. A particularly preferred heterocyclic hindered amine compound is di-(2,2,6,6-tetramethyl-4-piperidyl)sepacate. The amount of the heterocyclic hindered amine compound added is preferably 0.1 to 5.0 parts by weight based on 100 parts by weight of the polyphenylene ether resin or a resin mixture consisting of this and a styrene polymer.
More preferably, it is 0.5 to 3.0 parts by weight. The epoxy compound used in the present invention is
Compounds containing one or more, especially two or more, epoxy groups in the molecule are used. For example, compounds included in the glycidyl ether type, glycidyl ester type, glycidyl amine type, linear aliphatic epoxide type, and alicyclic epoxide type can be mentioned. The amount of the epoxy compound added is 0.1 to 100 parts by weight of the polyphenylene ether resin or a resin mixture consisting of this and a styrene polymer.
It is preferably 5.0 parts by weight, more preferably 0.5 to 3.0 parts by weight. The resin composition of the present invention can be obtained by blending the components detailed above, and these components can be mixed by methods known per se. For example, by mixing pellets together or by mixing pellets and powder. Examples include a method of kneading in an extruder and extrusion, a method of kneading and kneading using a kneader or roll and extruding into a sheet, and a method of mixing as a solution. The thermoplastic resin composition of the present invention contains commonly used additives such as plasticizers, lubricants, flame retardants,
Thermal antioxidants, reinforcing fillers, pigments, dyes or other light stabilizers can be added. EXAMPLES Hereinafter, the present invention will be explained in detail with reference to Examples, but the present invention is not limited thereto.
In addition, parts of each component in the examples indicate parts by weight, and the light resistance time is measured using a 75 x 45 x 3 mm injection molded piece and a 2.5KW xenon weatherometer (black panel temperature 63℃, relative humidity 50%). An accelerated light fastness test was performed through a 3 mm thick window glass (with no rain), and the color difference with the unirradiated specimen was measured (light source C, L*a*b), and yellowing was observed △
It means the irradiation time until YI=1. Comparative example 1 Intrinsic viscosity [η] (chloroform 25℃) is 0.47
Contains 45 parts of poly(2,6-dimethyl-1,4-phenylene) ether of dl/g and 8% rubber content,
MI value measured at 200℃ and 5Kg load is 2.2g/10
A total of 100 parts of a resin consisting of 55 parts of commercially available rubber-reinforced polystyrene, 13 parts of TPP (Triphenyl Phosphate manufactured by Daihachi Chemical Co., Ltd.) as a flame retardant,
After thoroughly mixing 0.5 parts of TDP (triisodecyl phosphite manufactured by Borg Warner) as a stabilizer and 5 parts of white pigment titanium oxide in a Henschel mixer until homogeneous, the mixture was subjected to twin-screw extrusion with a vacuum vent. The mixture was extruded using a machine at a set temperature of 290°C to form pellets. The obtained pellets were molded into 75 x 45 x 3 mm light resistance test pieces under injection molding conditions of an injection pressure of 1300 Kg/cm ² and a molding temperature of 240°C, and the light resistance time was measured using a 2.5 KW xenon weatherometer. did. The results are shown in Table 1. Comparative Examples 2 to 4 Test pieces were prepared in the same manner as in Comparative Example 1 using the types of ultraviolet absorbers shown in Table 3 in the proportions shown in Table 1 to 100 parts of the resin composition shown in Comparative Example 1, The light fastness time was measured. The results are shown in Table 1. Comparative Examples 5 and 6 Same as Comparative Example 1, using the heterocyclic hindered amine compound and epoxy compound of the types shown in Table 3 in the proportions shown in Table 1 based on 100 parts of the resin composition shown in Comparative Example 1. A test piece was prepared and the light resistance time was measured. The results are shown in Table 1. Examples 1 to 12 In the same manner as in Comparative Example 1, using the types of heterocyclic hindered amine compounds and epoxy compounds shown in Table 3 in the proportions shown in Table 1 based on 100 parts of the resin composition shown in Comparative Example 1. Prepare the specimen,
The light fastness time was measured. . The results are shown in Table 1. Examples 13 to 15 The amounts of poly(2,6-dimethyl-1,4-phenylene) ether and rubber-reinforced polystyrene in the resin composition used in Comparative Example 1 were changed as shown in Table 2, and further heterogeneous A test piece was prepared in the same manner as in Comparative Example 1 using a cyclic hindered amine compound and an epoxy compound in the proportions shown in Table 2, and then the light resistance time was measured. The results are shown in Table 2.

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Claims (1)

[Claims] 1 To 100 parts by weight of a polyphenylene ether resin or a resin mixture consisting of this and a styrene polymer,
(a) Heterocyclic hindered amine compound
1. A thermoplastic resin composition comprising 0.1 to 5.0 parts by weight and (b) 0.1 to 5.0 parts by weight of an epoxy compound.