JPH07173368A - Oxymethylene copolymer resin composition - Google Patents

Abstract

PURPOSE:To obtain an oxymethylene copolymer resin composition having excel lent thermal stability in the compounding of a coloring pigment by compounding an oxymethylene copolymer with plural specific kinds of compounds. CONSTITUTION:This resin composition is produced by compounding 100 pts.wt. of an oxymethylene copolymer with (A) 0.01-5 pts.wt. of a hindered phenol such as N,N'-hexamethylene-bis(3,5-di-t-butyl-4-hydroxy-hydroxycinnamamide), (B) 0.01-7 pts.wt. of an amine-substituted triazine compound such as (methylol) melamine, (C) 0.001-5 pts.wt. of a metal-containing compound selected from hydroxide, inorganic acid salt and alkoxide of alkali metal or alkaline earth metal, (D) 0.001-5 pts.wt. of a 10-36C fatty acid alkali metal or alkaline earth metal salt such as calcium laurate and (E) 0.01-5.0 pts.wt. of a fatty acid ester of a 2-10C polyhydric alcohol and a 10-32C higher fatty acid such as behenic acid glyceride and 0.01-5.0 pts.wt. of a >=10C higher fatty acid amide such as stearic acid amide.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION This invention relates to heat stabilized oxymethylene copolymer resin compositions, especially those having improved heat stability to color pigments.

[0002]

2. Description of the Related Art An oxymethylene copolymer obtained by copolymerizing trioxane with a cyclic ether having a C--C bond in the molecule (hereinafter sometimes abbreviated as "oxymethylene copolymer") is a copolymer thereof. It is well known that the components are easily decomposed from the terminal end, that they are decomposed by autoxidation accompanied by main chain scission, and that the thermal stability is greatly impaired as a result of these decompositions.

Further, when a coloring pigment represented by carbon black, titanium oxide or the like is blended for the purpose of coloring, the decomposition of these pigments is further promoted and the thermal stability of the oxymethylene copolymer is greatly impaired. It is also a fact that it is difficult to use as a plastic material.

So far, techniques for incorporating various stabilizers have been proposed for the purpose of improving the thermal stability of oxymethylene copolymers. For example, Japanese Examined Patent Publication No. 55-22508 discloses an alkaline earth metal salt of a sterically hindered phenol and a fatty acid having 10 to 22 carbon atoms and / or a hydroxide of an alkaline earth metal in Japanese Examined Patent Publication No. 60-56748. Japanese Patent Publication No. 62-44227 discloses an alkaline earth metal salt of a sterically hindered phenol and a fatty acid having 22 to 36 carbon atoms.
In the publication, polyamide and fatty acid having 12 to 35 carbon atoms,
Calcium salt of fatty acid having 12 to 35 carbon atoms, 12 carbon atoms
A combination of at least one of the group consisting of calcium or magnesium salts of 35 to 35 aliphatic alcohols with an amine-substituted triazine compound, a sterically hindered phenol and an alkali is disclosed in JP-B-62-58387.
Alternatively, a combination of an alkaline earth metal hydroxide, an inorganic acid salt, a carboxylate salt, or an alkoxide,
JP-A-4-63857 discloses a fatty acid ester of a polyhydric alcohol derived from a polyhydric alcohol having 2 to 10 carbon atoms and a higher fatty acid having 22 to 32 carbon atoms and a fatty acid having 12 to 35 carbon atoms. A combination of alkaline earth metal salts has been proposed. However, with these techniques, the thermal stability of oxymethylene copolymers is
Although improved, it is still inadequate, and the decrease in thermal stability when the color pigment is incorporated was hardly improved.

[0005]

The problem to be solved by the present invention is that when a coloring pigment represented by carbon black, titanium oxide or the like is blended for the purpose of coloring the oxymethylene copolymer, the copolymer is obtained. The purpose is to prevent the thermal stability of the material from being significantly impaired.

[0006]

The problem to be solved by the present invention is based on 100 parts by weight of an oxymethylene copolymer obtained by copolymerizing trioxane and a cyclic ether having a C—C bond in the molecule. (A) 0.01 to 5 parts by weight of sterically hindered phenol, (B) 0.01 to 7 parts by weight of amine-substituted triazine compound, and (C) hydroxide of alkali metal or alkaline earth metal, or inorganic acid At least one of the metal-containing compounds represented by the group consisting of salts or alkoxides 0.0
01 to 5 parts by weight, (D) 0.001 to 5 parts by weight of an alkali metal or an alkaline earth metal salt of a fatty acid having 10 to 36 carbon atoms, and (E) a polyhydric alcohol and carbon having 2 to 10 carbon atoms One or more fatty acid esters of polyhydric alcohols derived from higher fatty acids having the numbers 10 to 32, 0.01 to 5.0
And an oxymethylene copolymer resin composition obtained by blending 0.01 part by weight and (F) 0.01 to 5.0 parts by weight of one or more higher fatty acid amides having a long chain of 10 or more carbon atoms. Thermal stability was achieved.

In the present invention, the oxymethylene copolymer refers to a copolymer containing 0.4 to 40 mol%, preferably 0.4 to 10 mol% of oxyalkylene units in the oxymethylene main chain. Such copolymers include formaldehyde and / or cyclic oligomers thereof, such as
It can be obtained by reacting trioxane or tetraoxane with a cyclic ether or a cyclic acetal in the presence of a polymerization catalyst. As the polymerization catalyst, a generally known cationic polymerization catalyst can be used, but a compound containing boron fluoride is particularly preferable, and a hydrate and a coordination complex compound are used, and particularly, a compound with an ether is preferably used. The coordination complex boron trifluoride diethyl etherate is preferred.

As the cyclic ether or cyclic acetal used as a comonomer, compounds represented by the following general formula (1) are suitable.

[0009]

[Chemical 1]

Where R ₁ , R ₂ , R ₃ and R
₄ are the same or different and represent a hydrogen atom, an alkyl group, or a halogen-substituted alkyl group. R5 represents a methylene group, an oxymethylene group, a methylene group substituted with an alkyl group or a halogenated alkyl group, or an oxymethylene group (wherein n is an integer of 0 to 3) Or,
Further, it means a divalent group represented by the general formulas (2) and (3). In this case, n is 1 and m is an integer of 1 to 4. The above alkyl group has 1 to 5 carbon atoms and has 0 to 3 hydrogen atoms. It may be replaced by an atom, especially a chlorine atom.

Specific cyclic acetals or cyclic ethers include ethylene oxide, propylene oxide, epichlorohydrin, 1,3-dioxolane, 1,3-dioxepane, 1,3,5-trioxepane, 1,3,6-. Examples thereof include trioxocane.

The oxymethylene copolymer obtained by the polymerization reaction is diethylamine, triethylamine, di-
Primary amines, secondary amines, tertiary amines, and alkali metals shown in specific examples of iso-propylamine, tri-iso-propylamine, mono-n-butylamine, dibutylamine, tributylamine, piperidine, morpholine and the like. The catalyst can be inactivated and removed by a known method using a hydroxide of an alkaline earth metal, a trivalent organic phosphorus compound, or the like. Among these,
Method using a tertiary amine, and JP-B-55-42
The catalyst deactivation treatment method using a trivalent organic phosphorus compound shown in 085 is a preferable method.

The sterically hindered phenol which is the component (A) of the resin composition of the present invention basically means a compound having at least one structure represented by the general formula (4).

[0014]

[Chemical 2]

In the formula, R ₆ and R ₇ represent an alkyl group or a substituted alkyl group.

Specific examples of the sterically hindered phenol include:
2,2'-methylene-bis (4-methyl-6-t-butylphenol), 4,4'-methylene-bis (2,6-
Di-t-butylphenol), 1,3,5-trimethyl-2,4,6-tris (3,5-di-t-butyl-4-)
Hydroxobenzyl) benzene, 3,5-di-t-butyl-4-hydroxybenzyldimethylamine, stearyl-3,5-di-t-butyl-4-hydroxybenzylphosphonate, diethyl-3,5-di-t- Butyl-4
-Hydroxybenzylphosphonate, 2,6,7-trioxa-1-phospha-bicyclo [2,2,2] -oct-4-yl-methyl-3,5-di-t-butyl-4-
Hydroxyhydrocinnamate, 3,5-di-t-butyl-4-hydroxyphenyl-3,5-distearyl-
Thiotriazylamine, 2 (2'-hydroxy-3 ',
5'-di-t-butylphenyl) -5-chlorobenzotriazole, 2,6-di-t-butyl-4-hydroxymethylphenol, 2,4-bis- (n-octylthio) -6- (4- Hydroxy-3,5-di-t-butylanilino) -1,3,5-triazine, N, N′-hexamethylenebis (3,5-di-t-butyl-4-hydroxy-hydrocinnamamide), Octadecyl-3-
(3,5-Di-butyl-4-hydroxyphenyl) propionate, 1,6-hexanediol-bis [3-
(3,5-di-t-butyl-4-hydroxyphenyl)
Propionate], pentaerythrityl-tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], triethylene glycol-
Bis [3- (3,5-dimethyl-4-hydroxyphenyl) propionate], triethylene glycol-bis [3- (3-t-butyl-5-methyl-4-hydroxyphenyl) propionate] triethylene glycol-
Bis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], 2,2′-thiodiethyl-bis [3- (3,5-di-t-butyl-4-hydroxyphenyl) Propionate] and the like can be mentioned, but among these, particularly preferred are compounds having at least one structure represented by the general formula (5).

[0017]

[Chemical 3]

That is, as preferable specific examples thereof, among the above, N, N'-hexamethylenebis (3,3)
5-di-t-butyl-4-hydroxy-hydrocinnamamide), octadecyl-3- (3,5-di-butyl-4)
-Hydroxyphenyl) propionate, 1,6-hexanediol-bis [3- (3,5-di-t-butyl-
4-hydroxyphenyl) propionate], pentaerythrityl-tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], triethyleneglycol-bis [3- (3,5-dimethyl) -4-Hydroxyphenyl) propionate], triethylene glycol-bis [3- (3-t-butyl-5-
Methyl-4-hydroxyphenyl) propionate] triethylene glycol-bis [3- (3,5-di-t-
Butyl-4-hydroxyphenyl) propionate],
2,2'-thiodiethyl-bis [3- (3,5-di-t
-Butyl-4-hydroxyphenyl) propionate]
However, this is the case.

Among these, more preferable ones are:
1,6-hexanediol-bis [3- (3,5-di-
t-butyl-4-hydroxyphenyl) propionate], pentaerythrityl-tetrakis [3- (3,5
-Di-t-butyl-4-hydroxyphenyl) propionate], triethylene glycol-bis [3-
(3,5-dimethyl-4-hydroxyphenyl) propionate], triethylene glycol-bis [3- (3
-T-butyl-5-methyl-4-hydroxyphenyl)
Propionate] triethylene glycol-bis [3-
(3,5-di-t-butyl-4-hydroxyphenyl)
Propionate], 2,2′-thiodiethyl-bis [3
-(3,5-di-t-butyl-4-hydroxyphenyl) propionate].

The amine-substituted triazine compound which is the component (B) of the resin composition of the present invention is basically an amine-substituted triazine having a structure represented by the general formula (6), or the amino-substituted triazine. Means at least one initial polycondensation product of a class with formaldehyde.

[0021]

[Chemical 4]

In the formula, R ₈ , R ₉ and R ₁₀ are hydrogen atoms,
It means a halogen atom, a hydroxyl group, an alkyl group, an alkoxy group, an aryl group, a hydrogenated aryl group, an amino group, or a substituted amino group, at least one of which is an amino group or a substituted amino group.

Specific examples of the amine-substituted triazine compound or the initial polycondensation product of the amino-substituted triazine compound and formaldehyde include guanamine, melamine, and
N-butyl melamine, N-phenyl melamine, N, N-
Diphenylmelamine, N, N-diallylmelamine, N,
N ', N "-triphenylmelamine, N, N', N"-
Trimethylol melamine, benzoguanamine, 2,4-
Diamino-6-methyl-sym-triazine, 2,4-
Diamino-6-butyl-sym-triazine, 2,4-
Diamino-6-benzyloxy-sym-triazine,
2,4-diamino-6-butoxy-sym-triazine, 2,4-diamino-6-cyclohexyl-sym-
Triazine, 2,4-diamino-6-chloro-sym-
Triazine, 2,4-diamino-6-mercapto-sy
Examples thereof include m-triazine, amelin (N, N, N ', N'-tetracyanoethylbenzoguanamine), and initial polycondensates of them and formaldehyde. Among them, melamine, methylol melamine, benzoguanamine, and water-soluble melamine-formaldehyde resin are particularly preferable.

The component (C) of the resin composition of the present invention is a hydroxide of an alkali metal or an alkaline earth metal, or an inorganic acid salt or an alkoxide thereof, and the inorganic salt is a carbonate salt. , Phosphate, silicate, borate and the like. Examples of the alkoxide include methoxide and ethoxide. Among these, preferred are alkaline earth metal hydroxides, inorganic acid salts, and alkoxides, but more preferred are calcium hydroxide, magnesium hydroxide, potassium hydroxide calcium carbonate, and magnesium carbonate. Is.

Component (D) of the resin composition of the present invention is an alkali metal or alkaline earth metal salt of a fatty acid having 10 to 36 carbon atoms, preferably saturated having 10 to 36 carbon atoms, or The alkaline earth metal salts of unsaturated fatty acids include magnesium salts, calcium salts, barium salts, and strontium salts. Preferred specific examples of fatty acids include lauric acid, palmitic acid, stearic acid, and behenic acid. , Montanic acid, 12-hydroxystearic acid, oleic acid, erucic acid and the like.
Further, more preferable one is saturated one having 10 to 21 carbon atoms,
Alternatively, it is an alkaline earth metal salt of an unsaturated fatty acid.

The fatty acid ester of polyhydric alcohol as the component (E) of the resin composition of the present invention is a polyhydric alcohol having 2 to 10 carbon atoms and a higher alcohol having 10 to 32 carbon atoms, preferably 22 to 32 carbon atoms. It means an ester compound derived from a fatty acid. Specific examples of preferable polyhydric alcohols include glycerin, diglycerin, pentaerythritol, sorbitan, ethylene glycol, diethylene glycol, trimethylolmethane, and trimethylolethane. Preferred higher fatty acids have 22 to 3 carbon atoms.
It is a higher fatty acid of 2, and specific examples thereof include behenic acid, cerotic acid, montanic acid, laxeric acid and the like.

The higher fatty acid amide having a long chain having 10 or more carbon atoms, which is the component (F) of the resin composition of the present invention, has 1 carbon atom.
It means an amide compound derived from a higher fatty acid having a straight chain of 0 or more and an aliphatic amine, and preferable specific examples thereof include stearic acid amide, ethylene bis stearoamide, methylene bis stearoamide, and methylene bis lauroamide. , Palmitic acid amide, oleic acid amide and the like, and more preferable specific examples thereof include ethylene bis stearamide, methylene bis stearamide, and methylene bis lauroamide.

Next, the oxymethylene copolymer constituting the resin composition of the present invention and each of the components (A) to (F) are sterically hindered (A) with respect to 100 parts by weight of the oxymethylene copolymer. 0.01-5 parts by weight, preferably
0.01 to 1 part by weight and (B) amine-substituted triazine compound 0.01 to 7 parts by weight, preferably 0.1 to 1 part by weight and (C) alkali metal or alkaline earth metal hydroxide, or An inorganic acid salt or at least one of the metal-containing compounds represented by the group consisting of alkoxides
01 to 5 parts by weight, preferably 0.001 to 3 parts by weight and (D) an alkali metal salt of a fatty acid having 10 to 36 carbon atoms or an alkaline earth metal salt, 0.001 to 5 parts by weight, preferably 0. 0.01 to 5 parts by weight of one or more fatty acid ester of polyhydric alcohol derived from 0.01 to 3 parts by weight and (E) polyhydric alcohol having 2 to 10 carbon atoms and higher fatty acid having 22 to 32 carbon atoms. Parts, preferably 0.0
1 to 3 parts by weight and / or (F) 0.01 to 1 or more higher fatty acid amide having a long chain having 10 or more carbon atoms
5% by weight, preferably 0.01 to 3% by weight may be blended, but a composition comprising (A), (B), (C), (D), (E) and (F) components is preferred. Is. Also,
Regarding the blending amount of each component, if the amount is less than the above amount, the stabilizing effect is insufficient, and if it is too large, gas is generated during molding, the appearance of the molded product is deteriorated, etc., which is not preferable.

As the method for producing the oxymethylene copolymer resin composition of the present invention, various known methods can be adopted, but basically, the oxymethylene copolymer and (A) to
It is manufactured by melt-kneading the respective components of (E) and / or (F). Prior to melt-kneading, it is a preferred method to pre-mix each component with a mixing device such as a blender or a Henschel mixer. The premixing can be carried out in the dry state or in the form of a moistened substance, an emulsion or a suspension. The moisturizer, emulsion and suspension are prepared by adding water, methanol, acetone, benzene, toluene, cyclohexane, and other known solvents to the oxymethylene copolymer.

Further, the components (A) to (F) are directly converted into a molten oxymethylene copolymer through the addition port or the like attached to the barrel of the extruder or the like without the above-mentioned premixing. It is also possible to add.

The melt kneading of the components (A) to (F) and the oxymethylene copolymer may be carried out by any kneader such as various uniaxial or biaxial extruders, kneaders, Banbury mixers and the like. Is an extruder. More preferred is a single-screw or twin-screw extruder having a vent port and capable of degassing and removing decomposed formalin and impurities under reduced pressure. The melt-kneading temperature is usually set above the melting point of the oxymethylene copolymer, but 170 to 270 ° C. is a suitable temperature range.

In the resin composition of the present invention, if desired, other additives such as other stabilizers, fillers, pigments, lubricants, plasticizers, ultraviolet absorbers, flame retardants, flame retardant aids, etc. resin,
Other components such as an elastomer may be appropriately mixed.

Examples of fillers are mineral beads such as glass beads, wollastonite, mica, talc, kaolin, silicon dioxide, clay, asbestos, silica, diatomaceous earth, graphite and molybdenum disulfide, and glass. Inorganic fibers such as fibers, milled fibers, potassium titanate fibers, and boron fibers, and organic fibers represented by carbon fibers and aramid fibers can be used.

Hereinafter, the present invention will be described with reference to Examples, Examples, and
The embodiments and effects thereof will be specifically described with reference to comparative examples, but the following examples are for specific description and limit the embodiments of the present invention or the scope of the invention. As is not intended.

[0035]

【Example】

Reference Example 1 100 parts by weight of trioxane and 2.5 parts by weight of ethylene oxide as a comonomer were used as catalysts of boron trifluoride etherate and methylal as a chain transfer agent, and polymerization was carried out in a biaxial kneader having intermeshing paddles. went. After the completion of the polymerization, the catalyst was deactivated with a small amount of a benzene solution of triphenylphosphine and then pulverized to obtain an oxymethylene copolymer. p-chloroform (added α-pinene)
The intrinsic viscosity at medium temperature of 60 ° C. was 1.4 dl / g.

Reference Example 2 100 parts by weight of trioxane and 1,3-as a comonomer
Polymerization was carried out in a biaxial kneader with intermeshing paddles using 4.3 parts by weight of dioxolane as catalyst with boron triboride etherate and methylal as chain transfer agent. After completion of the polymerization, the catalyst was deactivated with a small amount of a benzene solution of tributylamine and then pulverized to obtain an oxymethine copolymer. p-chloroform (added α-pinene)
The intrinsic viscosity at medium temperature of 60 ° C. was 1.46 dl / g.

Example 1 100 parts by weight of the oxymethylene copolymer prepared in Reference Example 1 was mixed with triethylene glycol-bis [3- (3-t-
Butyl-5-methyl-4-hydroxyphenyl) propionate] (Ciba Geigy Corp. sterically hindered phenol, trade name Irganox 245) 0.5 part by weight, melamine 0.2 part by weight, and magnesium hydroxide 0. After adding 05 parts by weight, 0.1 parts by weight of calcium stearate, 0.12 parts by weight of behenic acid monoglyceride, and 0.15 parts by weight of ethylenebisstearamide, and pre-mixing with a Henschel mixer, According to a conventional method, a twin screw extruder was used for melt kneading [cylinder temperature: 200 ° C.], and then pelletization was performed to obtain a resin composition. The thermal stability of the resin composition was evaluated by using the pellets and measuring the retention thermal stability and the amount of formalin generated during molding. The thermal stability of the resin composition with respect to the coloring pigment was evaluated by blending 0.3 parts by weight of carbon black into the pellets, remelting and kneading with a twin-screw extruder, and then pelletizing the pellets. It was carried out by measuring the retention heat stability, and the amount of formalin generated during molding. The results of the evaluation test are shown in Table 1. The retention heat stability and the amount of formalin generated during molding were measured as follows. -Residual heat stability: Cylinder temperature 240 ° C, molding cycle 30 using injection molding machine with 75 ton clamping force
It was set to seconds and the time until silver was generated on the test piece was measured. -Amount of formalin generated during molding: Using an injection molding machine having a mold clamping pressure of 25 tons, a cylinder temperature of 190 ° C, a mold temperature of 65 ° C, a molding cycle of 15 seconds, and a molded product weighing 1.5 g [test Sample] was molded. The test sample molded here was immediately put in a closed sample container, and the amount of formaldehyde contained in the gas generated from the test sample was quantified.

Example 2 The same procedure as in Example 1 was carried out except that the oxymethylene copolymer prepared in Reference Example 1 was replaced by the oxymethylene copolymer prepared in Reference Example 2. The results shown in Table 1 were obtained.

Example 3 In Example 1, behenic acid monoglyceride 0.12
Behenic acid monoglyceride 0.06 instead of parts by weight
In the same manner as in Example 1 except that 0.075 parts by weight of ethylenebisstearoamide was used instead of 0.15 parts by weight of ethylenebisstearoamide,
The results shown in Table 1 were obtained.

Example 4 Table 1 shows the same procedure as in Example 1 except that the amount of ethylenebisstearamide was changed from 0.15 parts by weight to 0.00 parts by weight. The results shown were obtained.

Example 5 Example 5 was repeated except that the amount of behenic acid monoglyceride was changed from 0.12 parts by weight to 0.00 parts by weight.
The results shown in Table 1 were obtained in the same manner as in Example 1.

Comparative Example 1 In Example 1, the amount of behenic acid monoglyceride was changed from 0.12 parts by weight to 0.00 parts by weight, and the amount of ethylenebisstearoamide was changed from 0.15 parts by weight to 0.05 parts by weight.
The results shown in Table 1 were obtained in the same manner as in Example 1 except that the amount was changed to 0 part by weight.

Comparative Example 2 The results shown in Table 1 were obtained in the same manner as in Example 1 except that sodium caprate was used instead of calcium stearate.

COMPARATIVE EXAMPLE 3 Table 1 shows the same procedure as in Example 1 except that sodium caprate was used in place of calcium stearate and ethyl caprylate was used in place of behenic acid monoglyceride. I got the result.

Comparative Example 4 In Example 3, except that ethylene bis stearamide was replaced with propionic amide and behenic acid monoglyceride was replaced with ethyl caprylate,
The results shown in Table 1 were obtained in the same manner as in Example 1.

Example 6 In Example 1, triethylene glycol-bis [3
-(3-t-butyl-5-methyl-4-hydroxyphenyl) propionate] instead of pentaerythrityl-tetrakis [3- (3,5-di-t-butyl-4-]
Hydroxyphenyl) propionate] (Ciba Geigy's sterically hindered phenol, trade name Irganox 1010), except that calcium hydroxide was used instead of magnesium hydroxide and sodium montanate was used instead of calcium stearate. The results shown in Table 2 were obtained in the same manner as in Example 1.

Example 7 Example 1 was repeated except that the amount of behenic acid monoglyceride was changed to 0.60 parts by weight and the amount of ethylenebisstearoamide was changed to 0.075 parts by weight. The results shown in Table 2 were obtained in the same manner as in.

Example 8 Table 2 shows the same procedure as in Example 6 except that the amount of ethylenebisstearamide was changed from 0.15 parts by weight to 0.00 parts by weight. The results shown were obtained.

Example 9 Example 6 was repeated except that the amount of behenic acid monoglyceride was changed from 0.12 parts by weight to 0.00 parts by weight.
The results shown in Table 2 were obtained in the same manner as in Example 6.

Comparative Example 5 In Example 6, the compounding amount of behenic acid monoglyceride was 0.12 part by weight to 0.00 part by weight, and the compounding amount of ethylenebisstearoamide was 0.15 part by weight to 0.00 part by weight.
All except that the amount was changed to parts by weight, in the same manner as in Example 6,
The results shown in Table 2 were obtained.

[0051]

INDUSTRIAL APPLICABILITY The oxymethylene copolymer resin composition of the present invention contains the components (A) to (E) and / or (F) effectively acting on the oxymethylene copolymer. Thermal stability was achieved that was not achieved with conventional stabilizer combinations. In particular, the excellent thermal stability when blending color pigments typified by carbon black and titanium oxide is
It is difficult to predict from the conventional stabilizer compounding technology.

[0052]

[Table 1]

[0053]

[Table 2]

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takao Matsumura 2-4-16 Hinagahigashi, Yokkaichi-shi, Mie Sanryo Gas Chemical Co., Ltd. Yokkaichi Plant

Claims (1)

[Claims] 1. (A) 0.01 to 5 parts by weight of a sterically hindered phenol, (B) 0.01 to 7 parts by weight of an amine-substituted triazine compound, and (C) with respect to 100 parts by weight of an oxymethylene copolymer. At least one of the metal-containing compounds represented by the group consisting of alkali metal or alkaline earth metal hydroxides, inorganic acid salts, or alkoxides 0.0
01 to 5 parts by weight, (D) 0.001 to 5 parts by weight of an alkali metal or an alkaline earth metal salt of a fatty acid having 10 to 36 carbon atoms, and (E) a polyhydric alcohol and carbon having 2 to 10 carbon atoms One or more fatty acid esters of polyhydric alcohols derived from higher fatty acids having the numbers 10 to 32, 0.01 to 5.0
An oxymethylene copolymer having excellent thermal stability, which is obtained by mixing 0.01 part by weight and (F) 0.01 to 5.0 parts by weight of at least one higher fatty acid amide having a long chain having 10 or more carbon atoms. Resin composition.