JP3399483B2 - Oxymethylene copolymer resin composition - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a thermally stabilized oxymethylene copolymer resin composition, in particular to a copolymer having improved thermal stability to color pigments. The present invention relates to a united resin composition. [0002] An oxymethylene copolymer obtained by copolymerizing trioxane and a cyclic ether having a CC bond in a molecule (hereinafter sometimes abbreviated as an oxymethylene copolymer) has a It is well known that it is easily decomposed from the terminal of the copolymer component, and that the main chain is decomposed by autoxidation, and that the thermal stability is greatly impaired as a result of these decompositions. I have. [0003] When a coloring pigment represented by carbon black, titanium oxide or the like is blended for coloring purposes, the decomposition of these pigments is further promoted and the thermal stability of the oxymethylene copolymer is greatly impaired. It is also true that it is difficult to use as a plastic material. Heretofore, techniques for blending various stabilizers have been proposed for the purpose of improving the thermal stability of oxymethylene copolymers. For example, Japanese Patent Publication No. 55-22508 discloses an alkaline earth metal salt and / or a hydroxide of an alkaline earth metal of a sterically hindered phenol and a fatty acid having 10 to 22 carbon atoms. JP-A-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 acids having 12 to 35 carbon atoms,
Calcium salt of fatty acid having 12 to 35 carbon atoms, 12 carbon atoms
Japanese Patent Publication No. Sho 62-58387 discloses an amine-substituted triazine compound and a sterically hindered phenol and an alkali,
Or, a combination of an alkaline earth metal hydroxide, an inorganic acid salt, a carboxylate 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. Combinations of alkaline earth metal salts have been proposed. However, depending on these techniques, the thermal stability of the oxymethylene copolymer is
Although improved, it was still insufficient, and furthermore, the reduction in thermal stability when the coloring pigment was blended 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 problem is caused by the following problem. in Rukoto to prevent the thermal stability of the copolymer is significantly impaired. [0006] solving problems you try of the problem-solving means for the invention, oxymethylene copolymer 100 weight obtained by copolymerizing Polymerization of cyclic ethers have C-C bonds at in trioxane and molecular Parts by weight: (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) a hydroxide or inorganic acid salt of an alkaline earth metal. , Arco
At least one 0.001-5 parts by weight (D) an alkali metal fatty acid from 10 to 36 carbon atoms of the metal-containing compound represented by the group consisting of Kishido, or a 0.001 part by weight of an alkaline earth metal salt (E) at least one fatty acid ester of a polyhydric alcohol derived from a polyhydric alcohol having 2 to 10 carbon atoms and a higher fatty acid having 10 to 32 carbon atoms, from 0.01 to 5.0.
The parts by weight (F) oxymethylene copolymer resin composition obtained by blending a 0.01 to 5.0 weight of one or more higher fatty acid amides having a number 10 or more long chain carbon, excellent thermal stability Was achieved. In the present invention, the term "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, for example,
It is obtained by allowing a cyclic ether or a cyclic acetal to act on trioxane or tetraoxane in the presence of a polymerization catalyst. As the polymerization catalyst, a generally known cationic polymerization catalyst can be used. In particular, a compound containing boron fluoride is preferable, and a hydrate and a coordination complex compound are used. boron trifluoride diethyl over Terato place a complex is preferable. As the cyclic ether or cyclic acetal used as a comonomer, a compound represented by the following general formula (1) is preferable. [0009] Wherein R ₁ , R ₂ , R ₃ and R
₄ is the same or different and represents a hydrogen atom, an alkyl group, or an alkyl group substituted with halogen. R ₅ is a methylene group or an oxymethylene group,
Or a methylene group or an oxymethylene group each substituted with an alkyl group or a halogenated alkyl group (where n is an integer of 0 to 3), or a compound represented by the general formula (2): It means a divalent group represented by (3). In this case, n is 1 and m is an integer of 1 to 4. Further, the above alkyl group has 1 to 5 carbon atoms, and its hydrogen atom is 0 to 3 halogen atoms. It may be replaced by an atom, especially a chlorine atom. Specific examples of the cyclic acetal or cyclic ether include ethylene oxide, propylene oxide, epichlorohydrin, and 1,3-dioxolan, 1,3-dioxepane, 1,3,5-trioxepane, 1,3,6- Trioxocan and the like can be exemplified. The oxymethylene copolymer obtained by the polymerization reaction includes diethylamine, triethylamine, di-
Primary amine, secondary amine, tertiary amine, and alkali metal represented by specific examples such as iso-propylamine, tri-iso-propylamine, mono-n-butylamine, dibutylamine, tributylamine, piperidine, and morpholine The catalyst can be deactivated and removed by a known method using a hydroxide of an alkaline earth metal, a trivalent organic phosphorus compound, or the like. Among these,
A method using a tertiary amine, and JP-B-55-42
The catalyst deactivation treatment method using a trivalent organic phosphorus compound shown in No. 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). Embedded image 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-tert-butylphenol), 1,3,5-trimethyl-2,4,6-tris (3,5-di-tert-butyl-4-)
(Hydroxobenzyl) benzene, 3,5-di-tert-butyl-4-hydroxybenzyldimethylamine, stearyl-3,5-di-tert-butyl-4-hydroxybenzylphosphonate, diethyl-3,5-di-tert- 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, and among them, particularly preferred are compounds having at least one structure represented by the general formula (5). Embedded image That is, preferred examples of these are 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]
Corresponds to this. Further, of these, more preferred 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 of the initial polycondensates of aldehydes and formaldehyde. Embedded image In the formula, R ₈ , R ₉ and R ₁₀ represent a hydrogen atom,
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 polycondensate of the amino-substituted triazine compound with formaldehyde include guanamine, melamine, and the like.
N-butylmelamine, N-phenylmelamine, N, N-
Diphenylmelamine, N, N-diallylmelamine, N,
N ', N "-triphenylmelamine, N, N', N"-
Trimethylolmelamine, 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
m-triazine, amelin (N, N, N ', N'-tetracyanoethylbenzoguanamine), or an initial polycondensate thereof with formaldehyde. Among them, melamine, methylolmelamine, benzoguanamine and water-soluble melamine-formaldehyde resin are particularly preferred. The component (C) of the resin composition of the present invention, alkaline earth metal, inorganic acid salt, an alkoxide. Preferred are calcium hydroxide, magnesium hydroxide, calcium carbonate, and magnesium carbonate. The 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 a saturated or 10 to 36 carbon atom saturated or It is an alkaline earth metal salt of an unsaturated fatty acid, which means a magnesium salt, a calcium salt, a barium salt, a strontium salt, and the like. Preferred specific examples of the fatty acid include lauric acid, palmitic acid, stearic acid, and behenic acid. , Montanic acid, 12-hydroxystearic acid, oleic acid, erucic acid and the like.
Further, more preferred are saturated ones having 10 to 21 carbon atoms,
Alternatively, it is an alkaline earth metal salt of an unsaturated fatty acid. The fatty acid ester of the polyhydric alcohol as the component (E) of the resin composition of the present invention may be 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 preferred polyhydric alcohols include glycerin, diglycerin, pentaerythritol, sorbitan, ethylene glycol, diethylene glycol, trimethylolmethane, and triethylolethane. Preferred higher fatty acids have 22 to 3 carbon atoms.
And higher specific fatty acids, such as behenic acid, cerotic acid, montanic acid, and lacceric acid. The higher fatty acid amide having a long chain of 10 or more carbon atoms as 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 0 or more linear chains and an aliphatic amine. Preferred specific examples thereof include stearic acid amide, ethylenebisstearamide, methylenebisstearamide, and methylenebislauroamide. , Palmitic acid amide, oleic acid amide and the like, and more preferred specific examples include ethylene bis stearoamide, methylene bis stearoamide, and methylene bis lauroamide. Next, the oxymethylene copolymer and each of the components (A) to (F) constituting the resin composition of the present invention are used in the amount of (A) steric hindrance based on 100 parts by weight of the oxymethylene copolymer. Sex phenol 0.01 to 5 parts by weight, preferably
0.01 to 1 part by weight and (B) 0.01 to 7 parts by weight, preferably 0.1 to 1 part by weight, of an amine-substituted triazine compound and (C) a hydroxide or inorganic acid salt of an alkaline earth metal Alternatively, 0.001 to 5 parts by weight of at least one metal-containing compound represented by the group consisting of alkoxides,
Preferably, 0.001 to 3 parts by weight and (D) carbon number 10
From 36 to 36 parts by weight of an alkali metal or alkaline earth metal salt of a fatty acid, preferably 0.01 to 5 parts by weight
At least one fatty acid ester of a polyhydric alcohol derived from (C) 2 to 3 parts by weight, (E) a polyhydric alcohol having 2 to 10 carbon atoms and a higher fatty acid having 22 to 32 carbon atoms.
01-5 parts by weight, preferably 0.01 to 3 parts by weight, and your <br/>, 0.01 to 5 wt one or more higher fatty acid amides having the (F) having 10 or more long chain carbon, preferably Is 0.
A composition comprising (A), (B), (C), (D), (E) and (F) is preferred, although the composition may contain from 0 to 1 to 3 parts by weight. Also, regarding the amount of each component,
When the amount is less than the above amount, the stabilizing effect is insufficient, and when the amount is too large, gas generation during molding and poor appearance of the molded product are caused, which is not preferable. As the method for producing the oxymethylene copolymer resin composition of the present invention, various known methods can be employed. Basically, the oxymethylene copolymer and (A) to (A) are used.
(E), and is produced by benefit melt-kneading the respective components (F). Prior to melt-kneading, it is a preferable method to pre-mix the components with a mixing device such as a blender or a Henschel mixer. The premix is
In the dry state, or in the form of a humidified substance, emulsion, or suspension,
It can also be implemented. Wet products, emulsions, and suspensions are prepared by adding oxymethylene copolymer to water, methanol, acetone,
It is prepared by adding benzene, toluene, cyclohexane and the like, and other known solvents. The components (A) to (F) are directly mixed with the oxymethylene copolymer in a molten state from an addition port or the like attached to a barrel or the like of an extruder without performing the premixing described above. 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 kneading machine such as various single-screw or twin-screw extruders, kneaders and Banbury mixers, but is preferred. Is an extruder. More preferably, a single-screw or twin-screw extruder having a vent port and capable of degassing and removing decomposed formalin and impurities under reduced pressure is used. The melt-kneading temperature is usually set to be equal to or higher than the melting point of the oxymethylene copolymer, and a preferable temperature range is 170 to 270 ° C. The resin composition of the present invention may further contain, if desired, various additives such as stabilizers, fillers, pigments, lubricants, plasticizers, ultraviolet absorbers, flame retardants, and flame retardant auxiliaries. resin,
Other components such as an elastomer can be appropriately compounded. Examples of fillers include mineral fillers such as glass beads, wollastonite, mica, talc, kaolin, silicon dioxide, clay, asbestos, silica, diatomaceous earth, graphite, molybdenum disulfide, and glass. Examples thereof include inorganic fibers such as fibers, milled fibers, potassium titanate fibers, and boron fibers, and organic fibers represented by carbon fibers and aramid fibers. Hereinafter, the present invention will be described with reference examples, working examples,
A comparative example will be described to specifically explain the embodiments and effects, but the examples shown below are for specifically explaining and limit the embodiments and the scope of the present invention. Not as intended. Reference Example 1 100 parts by weight of trioxane, 2.5 parts by weight of ethylene oxide as a comonomer, boron triboride etherate as a catalyst, and methylal as a chain transfer agent. The polymerization was carried out in a shaft kneader. After 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 (α-pinene added)
The intrinsic viscosity at a medium temperature of 60 ° C. was 1.4 dl / g. Reference Example 2 100 parts by weight of trioxane and 1,3-
Using 4.3 parts by weight of dioxolane as a catalyst with boron triboride etherate and methylal as a chain transfer agent, polymerization was carried out in a biaxial kneader having intermeshing paddles. 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 (α-pinene added)
The intrinsic viscosity at medium 60 ° C. was 1.46 dl / g. Example 1 To 100 parts by weight of the oxymethylene copolymer produced in Reference Example 1, triethylene glycol-bis [3- (3-t-
[Butyl-5-methyl-4-hydroxyphenyl) propionate] (Sterically hindered phenol, trade name Irganox 245, manufactured by Ciba-Geigy), 0.5 parts by weight of melamine, 0.2 parts by weight of magnesium hydroxide, and 0.2 parts by weight of magnesium hydroxide. After adding and blending 0.05 parts by weight, 0.1 part by weight of calcium stearate, 0.12 parts by weight of behenic acid monoglyceride, and 0.15 parts by weight of ethylenebisstearamide, premixed using a Henschel mixer, According to a conventional method, melt kneading (cylinder temperature: 200 ° C.) was performed using a twin screw extruder, followed by pelletization to obtain a resin composition. The thermal stability of the resin composition was evaluated by using the pellets and measuring the retention heat stability and the amount of formalin generated during molding. The thermal stability evaluation of the resin composition with respect to the color pigment was performed by blending 0.3 parts by weight of carbon black with the above pellets, then remelting and kneading with a twin screw extruder, and then using the pellets obtained by pelletizing. , Retention heat stability, and the amount of formalin generated during molding were measured. Table 1 shows the results of the evaluation test. The retention heat stability and the amount of formalin generated during molding were measured as follows. Retention heat stability: Using an injection molding machine having a mold clamping force of 75 tons, the cylinder temperature was set to 240 ° C. and the molding cycle was set to 30 seconds, and the time until silver was generated on the test piece was measured.・
Amount of formalin generated during molding: A cylinder temperature of 190 ° C., a mold temperature of 65 ° C., a molding cycle of 15 seconds, and a weight of 1.
5 g of a molded product [test sample] was molded. The test sample molded here was immediately placed in a closed sample container, and the amount of formaldehyde contained in the gas generated from the test sample was quantified. Example 2 The procedure of Example 1 was repeated, except that the oxymethylene copolymer produced in Reference Example 2 was used instead of the oxymethylene copolymer produced in Reference Example 1. Thus, the results shown in Table 1 were obtained. Example 3 Example 1 was repeated except that behenic acid monoglyceride 0.12 was used.
0.06 behenic acid monoglyceride in place of parts by weight
Parts by weight, except that 0.075 part by weight of ethylene bis stearamide was used instead of 0.15 part by weight of ethylene bis stearamide, in the same manner as in Example 1,
The results shown in Table 1 were obtained. COMPARATIVE EXAMPLE 1 The procedure of Example 1 was repeated except that the amount of ethylenebisstearamide was changed from 0.15 part by weight to 0.00 part by weight. The results shown were obtained. Comparative Example 2 In Example 1, except that the compounding amount of behenic acid monoglyceride was changed from 0.12 parts by weight to 0.00 parts by weight.
In all, the results shown in Table 1 were obtained in the same manner as in Example 1. Comparative Example 3 In Example 1, the amount of behenic acid monoglyceride was changed from 0.12 part by weight to 0.00 part by weight, and the amount of ethylenebisstearamide was changed from 0.15 part by weight to 0.0 part by weight.
Except that the amount was changed to 0 parts by weight, the same results as in Example 1 were obtained, and the results shown in Table 1 were obtained. [0043] In Comparative Example 4 Example 3, except for using sodium caprate in place of calcium stearate are all in the same manner as in Example 1 to obtain the results shown in Table 1. [0044] In Comparative Example 5 Example 3, sodium caprate instead of calcium stearate, except for using caprylic acid ethyl instead of behenic acid monoglyceride are all in the same manner as in Example 1, are shown in Table 1 The result was obtained. Comparative Example 6 In Example 3, except that propionamide was used instead of ethylenebisstearamide and ethyl caprylate was used instead of behenic acid monoglyceride,
The results shown in Table 1 were obtained in the same manner as in Example 1. Example 4 In Example 1, triethylene glycol-bis [3
Pentaerythrityl-tetrakis [3- (3,5-di-tert-butyl-4-)-4-substituted- (3-tert-butyl-5-methyl-4-hydroxyphenyl) propionate]
Hydroxyphenyl) propionate] (Sterically hindered phenol, trade name Irganox 1010 manufactured by Ciba-Geigy), calcium hydroxide in place of magnesium hydroxide, and sodium montanate in place of calcium stearate. In the same manner as in Example 1, the results shown in Table 2 were obtained. Example 5 Example 4 was repeated except that the amount of behenic acid monoglyceride was changed to 0.06 parts by weight and the amount of ethylenebisstearamide was changed to 0.075 parts by weight. In the same manner as described above, the results shown in Table 2 were obtained. Comparative Example 7 In Example 4 , except that the blending amount of ethylene bis stearamide was changed from 0.15 part by weight to 0.00 part by weight, all were the same as in Example 4 and the results are shown in Table 2. The results shown were obtained. Comparative Example 8 Example 4 was repeated except that the amount of behenic acid monoglyceride was changed from 0.12 part by weight to 0.00 part by weight.
In all, the results shown in Table 2 were obtained in the same manner as in Example 4 . Comparative Example 9 In Example 4 , the amount of behenic acid monoglyceride was changed from 0.12 part by weight to 0.00 part by weight, and the amount of ethylenebisstearamide was changed from 0.15 part by weight to 0.00 part by weight.
Except for changing to parts by weight, all were the same as in Example 4 ,
The results shown in Table 2 were obtained. The oxymethylene copolymer resin composition of the present invention exhibits, in oxymethylene copolymer (A) ~ (E), and contact <br/>, each component of (F) is effective Work, thermal stability was achieved that was not achieved with conventional stabilizer combinations. In particular, excellent thermal stability when compounding a coloring pigment represented by carbon black and titanium oxide is difficult to predict from conventional stabilizer compounding techniques. [Table 1] [Table 2]

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI C08K 5/103 C08K 5/103 5/13 5/13 5/20 5/20 5/3492 5/3492 (56) References Kaihei 5-156118 (JP, A) European Patent Application Publication 289142 (EP, A2) (58) Fields investigated (Int. Cl. ⁷ , DB name) C08L 59/04

Claims (1)

(57) [Claims 1] With respect to 100 parts by weight of an oxymethylene copolymer, (A) 0.01 to 5 parts by weight of a sterically hindered phenol and (B) an amine-substituted triazine compound 0.1 part by weight. (C) alkaline earth metal hydroxide, inorganic acid salt, alcohol
At least one 0.001-5 parts by weight (D) an alkali metal fatty acid from 10 to 36 carbon atoms of the metal-containing compound represented by the group consisting of Kishido, or a 0.001 part by weight of an alkaline earth metal salt (E) at least one fatty acid ester of a polyhydric alcohol derived from a polyhydric alcohol having 2 to 10 carbon atoms and a higher fatty acid having 10 to 32 carbon atoms, from 0.01 to 5.0.
Parts by weight (F) excellent oxymethylene copolymer resin composition in thermal stability obtained by blending with one or more of 0.01 to 5.0 weight of a higher fatty acid amide having a number 10 or more long chain carbon.