JP6853020B2 - Granular composition for polyacetal resin and polyacetal resin composition - Google Patents

Description

The present invention relates to a granular composition for a polyacetal resin and a polyacetal resin composition.

Since the polyacetal resin is excellent in processability and productivity, it has an advantage that products and parts having a desired shape can be efficiently produced by various molding methods such as melt injection molding and melt extrusion molding.
On the other hand, polyacetal resins have conventionally been blended with various additives such as antioxidants and heat stabilizers in order to prevent deterioration due to heat and oxygen in the process of melting, and then melt-kneaded. Then, the polyacetal resin composition is produced. Such polyacetal resins are widely used in the fields of electrical and electronic materials, automobiles, various other industrial materials, food packaging, and parts materials.

As described above, polyacetal resin compositions containing various additives have been conventionally used, but there are also problems such as dusting of the additives themselves and dust explosion. In view of this problem, a technique has been proposed in which an additive composition containing calcium stearate is granulated into granules and then blended into a predetermined thermoplastic resin (see, for example, Patent Document 1).
Further, a technique for suppressing coloration caused by calcium stearate by heat when melting a resin has also been proposed (see, for example, Patent Document 2).

Japanese Unexamined Patent Publication No. 8-333477 Japanese Patent No. 5206093

However, the above-mentioned Patent Documents 1 and 2 describe a technique relating to the suppression of coloring of a nitrogen-containing compound, and a polyacetal resin composition having high purity, excellent production stability, and an extremely small amount of formaldehyde generated from a molded product after molding. No mention is made of the technology to be produced, and there is room for improvement in this respect.

Therefore, in the present invention, the granular additive for a polyacetal resin, which suppresses the coloring of the nitrogen-containing compound and has excellent uniformity, and the granular composition for the polyacetal resin are contained, and the product has high purity and long-term production. It is an object of the present invention to provide a polyacetal resin composition which can stably exhibit its performance, has excellent production stability, has extremely high thermal stability, and emits a significantly small amount of formaldehyde from a molded product after molding.

As a result of diligent research on the above-mentioned problems of the prior art, the present inventors can suppress the coloring of the nitrogen-containing compound by using a nitrogen-containing compound having a specific structure and an antioxidant, and the uniformity can be suppressed. An excellent granular composition for polyacetal resin can be obtained. By using the granular composition for polyacetal resin, the purity is high, the performance can be stably exhibited even in long-term production, and the production stability is excellent. We have found that we can provide a polyacetal resin composition having high thermal stability and an extremely small amount of formaldehyde emitted from the molded product after molding, and have completed the present invention.
That is, the present invention is as follows.

[1]
At least one type of (A) antioxidant and
A nitrogen-containing compound having two or more nitrogen atoms in at least one (B) molecule,
The, containing,
The average particle size is 100 μm or more and 861 μm or less.
Granular composition for polyacetal resin.
[2]
The granular composition for a polyacetal resin according to the above [1], wherein the loosened apparent specific gravity is 0.3 or more and 0.8 or less.
[3]
The granular composition for a polyacetal resin according to the above [1] or [2] , wherein the antioxidant (A) has a melting point of 30 ° C. or higher.
[4]
(C) The granular composition for a polyacetal resin according to any one of [1] to [3] above, further comprising a fatty acid ester.
[5]
(B) A nitrogen-containing compound having two or more nitrogen atoms in the molecule
The granular composition for a polyacetal resin according to any one of the above [1] to [4] , which is at least one selected from the group consisting of an imidazole compound, an aminotriazine compound, a triazole compound, and a hydrazide compound. Stuff.
[6]
The granular composition for a polyacetal resin according to any one of the above [1] to [5] , wherein the content of the (A) antioxidant is 20% by mass or more.
[7]
(D) The granular composition for a polyacetal resin according to any one of [1] to [6] above, further comprising a thermoplastic polymer (excluding a polyamide compound).
[8]
(E) The granular composition for a polyacetal resin according to any one of the above [1] to [7], further comprising an inorganic filler.
[9]
The granular composition for a polyacetal resin according to any one of [1] to [8] above,
Polyacetal resin and
, A polyacetal resin composition containing.
[10]
With 100 parts by mass of polyacetal resin,
0.1 to 10 parts by mass of the granular composition for polyacetal resin according to any one of [1] to [8] above.
The polyacetal resin composition according to the above [9].
[11]
The method for producing a polyacetal resin composition according to the above [10].
A method for producing a polyacetal resin composition, which comprises a step of melt-kneading the polyacetal resin and the granular composition for the polyacetal resin.
[12]
0.1 to 50 parts by mass of the granular composition for a polyacetal resin and the polyacetal resin 1
The process of melting and kneading 00 parts by mass to make a masterbatch,
After masterbatch, the process of melt-kneading the polyacetal resin and
The method for producing a polyacetal resin composition according to the above [11].

According to the present invention, coloring of a nitrogen-containing compound can be suppressed, and a uniform granular composition for a polyacetal resin can be obtained.
Further, by adding this granular composition for polyacetal resin, it has high purity, stable performance can be exhibited even in long-term production, excellent production stability, extremely high thermal stability, and a molded product after molding. A polyacetal resin composition in which the amount of formaldehyde released from is significantly small can be obtained.

Hereinafter, embodiments for carrying out the present invention (hereinafter, referred to as “the present embodiment”) will be described in detail. The following embodiments are examples for explaining the present invention, and are not intended to limit the present invention to the following contents. The present invention can be appropriately modified and implemented within the scope of the gist thereof.

[Granular composition for polyacetal resin]
The granular composition for a polyacetal resin of the present embodiment is
(A) At least one selected from antioxidants and
(B) At least one selected from nitrogen-containing compounds having two or more nitrogen atoms in the molecule,
, Contain.

((A) Antioxidant)
The granular composition for a polyacetal resin of the present embodiment contains at least one kind of (A) antioxidant.
The antioxidant (A) has a melting point of 30 ° C. or higher, more preferably 40 ° C. or higher, and even more preferably 50 ° C. or higher.
When the melting point is 30 ° C. or higher, melting during storage in summer can be prevented, and good handleability as an additive can be obtained.

As the (A) antioxidant, a hindered phenolic antioxidant is preferable from the viewpoint of easy availability.
The antioxidant (A) is not limited to the following, but is, for example, n-octadecyl-3- (3', 5'-di-t-butyl-4'-hydroxyphenyl) -propionate, n. -Octadecyl-3- (3'-methyl-5-t-butyl-4'-hydroxyphenyl) -propionate, n-tetradecyl-3- (3', 5'-di-t-butyl-4'-hydroxyphenyl ) -Propionate, 1,6-hexanediol-bis- (3- (3,5-di-t-butyl-4-hydroxyphenyl) -propionate), 1,4-butanediol-bis- (3- (3) , 5-Di-t-Butyl-4-hydroxyphenyl) -propionate), triethylene glycol-bis- (3- (3-t-butyl-5-methyl-4-hydroxyphenyl) -propionate), tetrakis- ( Methylene-3- (3', 5'-di-t-butyl-4'-hydroxyphenyl) propionate methane, 3,9-bis (2- (3- (3-t-butyl-4-hydroxy-) 5-Methylphenyl) propionyloxy) -1,1-dimethylethyl) 2,4,8,10-tetraoxaspiro (5,5) undecane, N, N'-bis-3- (3', 5'- Di-t-Butyl-4-hydroxyphenol) Pripyonyl hexamethylenediamine, N, N'-tetramethylenebis-3- (3'-methyl-5'-t-butyl-4-hydroxyphenol) propionyldiamine, N, N'-bis- (3- (3,5-di-t-butyl-4-hydroxyphenol) propionyl) hydrazine, N-salicyloyl-N'-salicylidene hydrazine, 3- (N-salicyloyl) amino -1,2,4-triazole, N, N'-bis (2- (3- (3,5-di-butyl-4-hydroxyphenyl) propionyloxy) ethyl) oxyamide and the like can be mentioned.

Among the hindered phenolic antioxidants, triethylene glycol-bis- (3- (3-t-butyl-5-methyl-4-hydroxyphenyl) -propionate), especially from the viewpoint of availability. Tetrax- (methylene-3- (3', 5'-di-t-butyl-4'-hydroxyphenyl) propionate) methane, 3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionic acid Stearyl is preferred.
As the antioxidant, only one type may be used alone, or two or more types may be used in combination.

The content of the (A) antioxidant in the granular composition for a polyacetal resin of the present embodiment is preferably 20% by mass or more, more preferably 30% by mass or more, still more preferably 40% by mass or more.
When it is 20% by mass or more, the coloring of the nitrogen-containing compound (B) described later can be effectively suppressed.

((B) Nitrogen-containing compound having two or more nitrogen atoms in the molecule)
The granular composition for a polyacetal resin of the present embodiment contains a nitrogen-containing compound having two or more nitrogen atoms in at least one kind of (B) molecule.
(B) The nitrogen-containing compound having two or more nitrogen atoms in the molecule is not limited to the following, but is, for example, an aminotriazine-based compound, an imidazole-based compound, an amide-based compound, a urea-based compound, and a hydrazide-based compound. Examples thereof include compounds, guanidine-based compounds, and triazole-based compounds.
(B) As the nitrogen-containing compound having two or more nitrogen atoms in the molecule, only one type may be used alone, or two or more types may be used in combination.

Examples of the aminotriazine-based compound include, but are not limited to, (1) dicyandiamide, (2) amino-substituted triazine, and (3) a cocondensate of amino-substituted triazine and formaldehyde.
(2) The amino-substituted triazine is not limited to the following, but is, for example, guanamine (2,4-diamino-sim-triazine), melamine (2,4,6-triamino-sim-triazine), N. -Butyl melamine, N-phenyl melamine, N, N-diphenyl melamine, N, N-diallyl melamine, N, N', N''-triphenyl melamine, N-methylol melamine, N, N'-dimethylol melamine, N, N', N''-trimethylol melamine, benzoguanamine (2,4-diamino-6-phenyl-sim-triazine), 2,4-diamino-6-methyl-sim-triazine, 2,4-diamino- 6-Butyl-thym-triazine, 2,4-diamino-6-benzyloxy-sim-triazine, 2,4-diamino-6-butoxy-sim-triazine, 2,4-diamino-6-cyclohexyl-sim-triazine , 2,4-Diamino-6-Chloro-Sym-Triazine, 2,4-Diamino-6-Mercapto-Sym-Triazine, 2,4-Dioxy-6-Amino-Sym-Triazine (Amerite), 2-Oxy- Examples thereof include 4,6-diamino-sim-triazine (amelin), N, N', N'-tetracyanoethylbenzoguanamine and the like.
(3) Examples of the cocondensate of amino-substituted triazine and formaldehyde include, but are not limited to, a melamine-formaldehyde polycondensate.
Among these, dicyandiamide, melamine and melamine-formaldehyde polycondensate are preferable.

Examples of the imidazole compound include, but are not limited to, imidazole, 1-methylimidazole, 2-methylimidazole, 1,2-dimethylimidazole, 2-phenylimidazole and the like.

The amide-based compound is not limited to the following, but is, for example, polyamide 6, polyamide 66, polymethoxylylene diadipamide (polyamide MXD6), polyamide dimerate, polyamide 12, 6/66/610/12. Examples thereof include a quaternary copolymerized polyamide, a 6/66/610 ternary copolymerized polyamide, and a 6/12 copolymerized polyamide.

Examples of the urea-based compound include, but are not limited to, alkylene urea such as biuret, biurea, ethylene urea, and propylene urea. Among these, ethylene urea is preferable.

The hydrazide compounds are not limited to the following, but for example, 3,9-bis (2-carboxyethyl) -2,4,8,10-tetraoxaspiro [5,5] undecandidihydrazide, 1 , 3,5-Tris (3-carboxypropyl) isocyanurate trihydrazide and the like; polymer-type hydrazide compounds such as (meth) acrylic acid hydrazide alone or a copolymer can be mentioned.
Among these, it is preferable to use a dihydrazide compound. More preferably, aliphatic dihydrazide compounds such as 1,12-dodecanedicarboxylic acid dihydrazide, sebacic acid dihydrazide and adipic acid dihydrazide; 1,8-naphthalenedicarboxylic acid dihydrazide, 2,6-naphthalenecarboxylic acid dihydrazide, terephthalic acid dihydrazide and the like. It is an aromatic dihydrazide compound.

Examples of the guanidine compound include, but are not limited to, glycosiamine, guanolin, glycosiamidin, oxalylguanidine, creatinine, iminourazole, malonylguanidine, mesoxalylguanidine and the like.

The triazole-based compound is not limited to the following, and is, for example, 2- (2'-hydroxy-5'-methylphenyl) benzotriazole, 2- (2'-hydroxy-3', 5'-di. -T-butylphenyl) benzotriazole, 2- (2'-hydroxy-3', 5'-di-t-amylphenyl) benzotriazole, 2- (2'-hydroxy-3', 5'-diisoamylphenyl) ) Benzotriazoles having a hydroxyl group such as benzotriazole and an alkyl group (preferably C _1-6 alkyl group) substituted aryl group; 2- [2'-hydroxy-3', 5'-bis (α, α-) Dimethylbenzyl) phenyl] Benzotriazoles having a hydroxyl group such as benzotriazole and an aralkyl group or an aryl group substituted aryl group; a hydroxyl group such as 2- (2'-hydroxy-4'-octoxyphenyl) benzotriazole and an alkoxy _Examples thereof include benzotriazoles having a group (preferably C 1-12 alkoxy group) substituted aryl group. Among the above, benzotriazole compounds include benzotriazoles having a hydroxyl group and a C _3-6 alkyl group-substituted C _6-10 aryl group (particularly a phenyl group), and a hydroxyl group and a C _6-10 aryl-. _{Bentriazoles having a} C 1-6 alkyl group (particularly a phenyl C _1-4 alkyl group) substituted aryl group are preferred.

(Characteristics of granular composition for polyacetal resin)
Since the granular composition for polyacetal resin of the present embodiment is granular, the addition concentration can be increased with high productivity with respect to the polyacetal resin.
Here, "granular" means a powder having a loosened apparent specific gravity, that is, a powder having a specific gravity of 0.3 or more in a natural state containing a gas such as air, and an average particle size of 100 μm or more. ..
The granular composition for a polyacetal resin of the present embodiment is preferably a powder having a loosened apparent specific gravity, that is, a specific gravity of 0.3 or more in a natural state containing a gas such as air.
As a result, it becomes excellent in transport efficiency when packed in a predetermined container and transported, measurable when handling polyacetal, and powder handleability.
The loosened apparent specific gravity is more preferably 0.4 or more, and further preferably 0.45 or more.
The upper limit is preferably 0.8 or less from the viewpoint of improving the accuracy of the weighing and the quantitative feeder when the loosened apparent specific gravity is 0.8 or less when the amount of the granular composition for polyacetal resin used is small. ..
The loosened apparent specific gravity can be measured by a powder tester (manufactured by Hosokawa Micron Co., Ltd .: powder tester TYPE PT-E) using a metal container having a volume of 100 mL.
Specifically, it can be measured by the method described in Examples described later.
In the granular composition for polyacetal resin of the present embodiment, the loosened apparent specific gravity can be controlled within the above-mentioned numerical range by controlling the operating conditions.

The granular composition for a polyacetal resin of the present embodiment preferably has an average particle size of 100 μm or more and 2 mm or less.
When the average particle size is 100 μm or more, good production stability can be obtained even when the polyacetal resin composition is produced for a long period of time. In addition, it is possible to prevent the generation of powder residue in the additive hopper, and it is excellent in handleability.
When the thickness is 2 mm or less, it does not take an excessive amount of time to uniformly knead with the polyacetal resin, and an effect that the degree of freedom of processing conditions is high can be obtained.
From the viewpoint of the uniformity of the granular composition for polyacetal resin in the polyacetal resin composition pellets and the suppression of foreign substances in the polyacetal resin composition pellets, the average particle size is more preferably 1.5 mm or less, further preferably 1.0 mm or less. preferable.
Further, from the viewpoint that the performance can be stably exhibited and the production stability is enhanced, 200 μm or more is more preferable, and 400 μm or more is further preferable.
The average particle size of the granular composition for polyacetal resin of the present embodiment can be measured by the method described in Examples described later.

((C) Fatty Acid Ester)
The granular composition for a polyacetal resin of the present embodiment may further contain (C) fatty acid ester.
The fatty acid ester (C) is not limited to the following, and includes, for example, glycerin monopalmitate, glycerin dipalmitate, glycerin tripalmitate, glycerin monostearate, glycerin distearate, glycerin tristearate, and the like. Glycerin monobehenate, glycerin dibehenate, glycerin tribehenate, glycerin monomontanate, glycerin dimontanate, glycerin trimontanate, pentaerythritol monopalmitate, pentaerythritol dipalmitate, pentaerythritol tripalmitate, penta Ellisritol tetrapalmitate, pentaerythritol monostearate, pentaerythritol distearate, pentaerythritol tristearate, pentaerythritol tetrastearate, pentaerythritol monobehenate, pentaerythritol dibehenate, pentaerythritol tribehenate, pentaerythritol Tetrabehenate, pentaerythritol monomontanate, pentaerythritol dimontanate, pentaerythritol trimontanate, pentaerythritol tetramontanate, sorbitan monopalmitate, sorbitan dipalmitate, sorbitan tripalmitate, sorbitan monostearate, sorbitan Glycerate, sorbitan tristearate, sorbitan monobehenate, sorbitan dibehenate, sorbitan tribehenate, sorbitan monomontanate, sorbitan dimontanate, sorbitan trimontanate, sorbitol monopalmitate, sorbitol dipalmitate, Sorbitol glycermitate, sorbitol monostearate, sorbitol distearate, sorbitol tristearate, sorbitol monobehenate, sorbitol dibehenate, sorbitol tribehenate sorbitol monomontanate, sorbitol dimontanate, sorbitol trimontane, etc. Can be mentioned.
Further, a fatty acid ester compound in which a hydroxyl group is blocked with boric acid or the like can also be used, and examples thereof include, but are not limited to, a glycerin monofatty acid ester borate ester.
Further, an ester of an alcohol and a dicarboxylic acid can also be used, and examples of the alcohol include methyl alcohol, ethyl alcohol, propyl alcohol, n-butyl alcohol, isobutyl alcohol, t-butyl alcohol, n-amyl alcohol, 2-pentanol, and n. Saturated / unsaturated alcohols such as −heptyl alcohol, n-octyl alcohol, n-nonyl alcohol, lauryl alcohol, myristyl alcohol, cetyl alcohol, stearyl alcohol, and behenyl alcohol can be mentioned, and examples of the dicarboxylic acid include oxalic acid, malonic acid, and the like. Examples thereof include succinic acid, glutaric acid, adipic acid, pimeric acid, suberic acid, azelaic acid, sebacic acid, undecanic acid, brushphosphoric acid, maleic acid, fumaric acid, and glutaconic acid. The ester of these alcohols and a dicarboxylic acid may be a monoester or a diester.

((D) Thermoplastic polymer)
The granular composition for a polyacetal resin of the present embodiment can further contain (D) a thermoplastic polymer.
As the thermoplastic polymer (D), polyacetal, polyamide-based resin, and polyolefin-based resin are preferable.

((E) Inorganic filler)
The granular composition for a polyacetal resin of the present embodiment may contain (E) an inorganic filler. Examples of the inorganic filler include, but are not limited to, fibrous reinforcing agents such as glass fiber and carbon fiber; glass beads, calcium carbonate, talc, clay and the like.
In particular, talc, clay, and calcium carbonate are preferable from the viewpoint of availability and price.

(Other additives)
The granular composition for a polyacetal resin of the present embodiment may contain various conventionally known additives.
For example, formic acid scavengers, various stabilizers, for example, weather resistant (light) stabilizers, mold release agents, etc. can be used alone or in combination thereof.

Examples of the formic acid trapping agent include, but are not limited to, formic acid trapping agents such as hydroxides, inorganic acid salts, carboxylates and alkoxides of alkali metals or alkaline earth metals. Be done.
Hydroxides, inorganic acid salts, carboxylates and alkoxides of alkali metals or alkaline earth metals are not limited to the following, but are not limited to, for example, hydroxides such as sodium, potassium, magnesium, calcium or barium. , Carbonates, phosphates, silicates, borates, and carboxylates of the metal. The carboxylic acid of the carboxylic acid salt is a saturated or unsaturated aliphatic carboxylic acid having 10 to 36 carbon atoms, and these carboxylic acids may be substituted with a hydroxyl group. Examples of saturated aliphatic carboxylic acids include capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid, behenic acid, lignoceric acid, cerotic acid, montanic acid, melissic acid, and seroplastic acid. Examples of the unsaturated aliphatic carboxylic acid include undecylenic acid, oleic acid, elaidic acid, setreic acid, erucic acid, brassic acid, sorbic acid, linoleic acid, linolenic acid, arachidonic acid, propiole acid, stearolic acid and the like. Examples of the alkoxide include methoxide and ethoxide of the above metals.

As the weather resistant (light) stabilizer, (a) a benzotriazole-based substance, (b) an oxalic acid anilide-based substance, and (c) a hindered amine-based substance are preferable.
The (a) benzotriazole-based substance is not limited to the following, but is, for example, 2- (2'-hydroxy-5'-methyl-phenyl) benzotriazole, 2- [2'-hydroxy-3. , 5-di-t-butyl-phenyl) benzotriazole, 2- [2'-hydroxy-3,5-di-isoamyl-phenyl) benzotriazole, 2- [2'-hydroxy-3,5-bis- (Α, α-Dimethylbenzyl) phenyl] -2H-benzotriazole, 2- (2'-hydroxy-4'-octoxyphenyl) benzotriazole and the like can be mentioned, with preference given to 2- [2'-hydroxy-3. , 5-Bis- (α, α-Dimethylbenzyl) phenyl] -2H-benzotriazole, 2- [2'-hydroxy-3,5-di-t-butyl-phenyl) benzotriazole.
The (b) oxalic acid anilide-based substance is not limited to the following, and is, for example, 2-ethoxy-2'-ethyloxalic acid bisanilide, 2-ethoxy-5-t-butyl-2. '-Ethyl oxalic acid bisanilide, 2-ethoxy-3'-dodecyl oxalic acid bisanilide and the like can be mentioned.
Only one of these substances may be used alone, or two or more of these substances may be used in combination.
The (c) hindered amine-based substance is not limited to the following, but is, for example, 4-acetoxy-2,2,6,6-tetramethylpiperidine, 4-stearoyloxy-2,2,6,6. -Tetramethylpiperidine, 4-acryloyloxy-2,2,6,6-tetramethylpiperidine, 4- (phenylacetoxy) -2,2,6,6-tetramethylpiperidine 4-benzoyloxy-2,2,6 , 6-Tetramethylpiperidine, 4-methoxy-2,2,6,6-tetramethylpiperidine, 4-stearyloxy-2,2,6,6-tetramethylpiperidine, 4-cyclohexyloxy-2,2,6 , 6-Tetramethylpiperidine, 4-benzyloxy-2,2,6,6-tetramethylpiperidine, 4-phenoxy-2,2,6,6-tetramethylpiperidine, 4- (ethylcarbamoyloxy) -2, 2,6,6-tetramethylpiperidine, 4- (cyclohexylcarbamoyloxy) -2,2,6,6-tetramethylpiperidine, 4- (phenylcarbamoyloxy) -2,2,6,6-tetramethylpiperidine , Bis (2,2,6,6-tetramethyl-4-piperidine) -carbonate, bis (2,2,6,6-tetramethyl-4-piperidyl) -oxalate, bis (2,2,6,6) -Tetramethyl-4-piperidyl) -malonate, bis (2,2,6,6-tetramethyl-4-piperidyl) -sevacate, bis (2,2,6,6-tetramethyl-4-piperidyl) -adipate , Bis (2,2,6,6-tetramethyl-4-piperidyl) -terephthalate, 1,2-bis (2,2,6,6-tetramethyl-4-piperidyloxy) -ethane, α, α' -Bis (2,2,6,6-tetramethyl-4-piperidyloxy) -p-xylene, bis (2,2,6,6-tetramethyl-4-piperidyl) trilen-2,4-dicarbamate, Bis (2,2,6,6-tetramethyl-4-piperidyl) -hexamethylene-1,6-dicarbamate, tris (2,2,6,6-tetramethyl-4-piperidyl) -benzene-1, Examples thereof include 3,5-tricarboxylate, tris (2,2,6,6-tetramethyl-4-piperidyl) -benzene-1,3,4-tricarboxylate, and bis (2,2) is preferable. , 6,6-tetramethyl-4-piperidyl) -sevacate. Only one kind of each of the above hindered amine substances may be used alone, or two or more kinds thereof may be used in combination. Further, a combination of the above-mentioned benzotriazole-based substance, oxalic acid anilide-based substance and hindered amine-based substance is more preferable.

Examples of the release agent include alcohols, esters of alcohols and fatty acids, esters of alcohols and dicarboxylic acids, silicone oils, and the like.
The alcohol is not limited to the following, but includes, for example, monohydric alcohol and polyhydric alcohol, and the monohydric alcohol is not limited to the following, but is not limited to, for example, octyl alcohol, capryl alcohol, and the like. Nonyl alcohol, decyl alcohol, undecyl alcohol, lauryl alcohol, tridecyl alcohol, myristyl alcohol, bentadecyl alcohol, cetyl alcohol, hebutadecyl alcohol, stearyl alcohol, oleyl alcohol, nonadecil alcohol, eikosyl alcohol, pehenyl alcohol, Examples thereof include ceryl alcohol, melisyl alcohol, 2-hexyldecanol, 2-octyldodecanol, 2-decyltetradecanol, uniline alcohol and the like.
Examples of the polyhydric alcohol include, but are not limited to, polyhydric alcohols containing 2 to 6 carbon atoms, and specific examples thereof include ethylene glycol, diethylene glycol, triethylene glycol, and propylene. Glycoldipropylene glycol, butanediol, pentanediol, hexanediol, glycerin, diglycerin, triglycerin, threitol, erythritol, pentaerythritol, arabitol, libitol, xylitol, sorbite, sorbitan, sorbitol, mannitol and the like can be mentioned.
As the ester of the alcohol and the fatty acid, among the fatty acid compounds, a fatty acid selected from palmitic acid, stearic acid, bechenic acid and montanic acid is preferably used, and a polyhydric alcohol selected from glycerin, pentaerythritol, sorbitan and sorbitol. Examples include fatty acid esters.
The hydroxyl groups of these fatty acid ester compounds may or may not be present, and do not limit the fatty acid ester compounds. The ester of the alcohol and the fatty acid may be a monoester, a diester, or a triester. Further, the hydroxyl group may be blocked by boric acid or the like.
Preferred fatty acid esters include, but are not limited to, glycerin monopalmitate, glycerin dipalmitate, glycerin tripalmitate, glycerin monostearate, glycerin disstearate, glycerin tristearate, glycerin monobe. Henate, glycerin dibehenate, glycerin tribehenate, glycerin monomontanate, glycerin dimontanate, glycerin trimontanate, pentaerythritol monopalmitate, pentaerythritol dipalmitate, pentaerythritol tripalmitate, pentaerythritol tetra Palmitate, pentaerythritol monostearate, pentaerythritol distearate, pentaerythritol tristearate, pentaerythritol tetrastearate, pentaerythritol monobehenate, pentaerythritol dibehenate, pentaerythritol tribehenate, pentaerythritol tetrabe Henate, pentaerythritol monomontanate, pentaerythritol dimontanate, pentaerythritol trimontanate, pentaerythritol tetramontanate, sorbitan monopalmitate, sorbitan dipalmitate, sorbitan tripalmitate, sorbitan monostearate, sorbitan disteer Rate, sorbitan tristearate, sorbitan monobehenate, sorbitan dibehenate, sorbitan tribehenate, sorbitan monomontanate, sorbitan dimontanate, sorbitan trimontanate, sorbitol monopalmitate, sorbitol dipalmitate, sorbitol tri Palmitate, sorbitol monostearate, sorbitol distearate, sorbitol tristearate, sorbitol monobehenate, sorbitol dibehenate, sorbitol tribehenate sorbitol monomontanate, sorbitol dimontanate, sorbitol trimontanate, etc. Be done.
The fatty acid ester compound in which the hydroxyl group is blocked with boric acid or the like is not limited to the following, and examples thereof include a borate ester of a glycerin monofatty acid ester.
Regarding the esters of alcohol and dicarboxylic acid, the alcohols are methyl alcohol, ethyl alcohol, propyl alcohol, n-butyl alcohol, isobutyl alcohol, t-butyl alcohol, n-amyl alcohol, 2-pentanol, n-heptyl alcohol, n-. Saturated / unsaturated alcohols such as octyl alcohol, n-nonyl alcohol, lauryl alcohol, myristyl alcohol, cetyl alcohol, stearyl alcohol, and behenyl alcohol are used. Dicarboxylic acids include oxalic acid, malonic acid, succinic acid, glutaric acid, and adipic acid. , Pimeric acid, suberic acid, azelaic acid, sebacic acid, undecanic acid, brush phosphate, maleic acid, fumaric acid, glutaconic acid and the like are used, and the esters of these alcohols and dicarboxylic acids may be monoesters. It may be a diester.

[Polyacetal resin composition]
The polyacetal resin composition of the present embodiment includes the above-mentioned granular composition for polyacetal resin of the present embodiment and the above-mentioned granular composition for polyacetal resin.
Polyacetal resin and
, Contain.

(Polyacetal resin)
The polyacetal resin used in the polyacetal resin composition of the present embodiment is a polyoxymethylene homopolymer composed of _{substantially oxymethylene units − (CH 2 O) − obtained by copolymerization of cyclic oligomers such as formaldehyde, trioxane or tetraoxane.} Or, an oximethylene unit obtained by copolymerizing formaldehyde and / or trioxane with cyclic formal to which cyclic ether and / or cyclic formal or hindered phenolic antioxidant is added in an amount of 1% by mass or more and 500% by mass or less. Examples thereof include a polyoxymethylene copolymer having a structure in which an oxyalkylene unit represented by the following general formula (1) is randomly inserted in a chain consisting of (CH _{2 O) −.}

_{R 1} and R ₂ in the formula (1) are independently hydrogen atoms, alkyl groups, or aryl groups, and they may be the same or different. n is an integer of 2-6.

Polyoxymethylene copolymers also include branched polyoxymethylene copolymers with branched molecular chains and polyoxymethylene block copolymers with dissimilar component blocks containing 50% by mass or more of oxymethylene repeating units.
The insertion rate of the oxyalkylene unit in the polyoxymethylene copolymer is preferably 0.01 mol or more and 50 mol or less, more preferably 0.03 mol or more and 20 mol or less, with respect to 100 mol of the oxymethylene unit. is there. Examples of the oxyalkylene unit include an oxyethylene unit, an oxypropylene unit, an oxytetramethylene unit, an oxybutylene unit, an oxyphenylethylene unit and the like. Among these oxyalkylene units, from the viewpoint of improving the physical properties of the polyacetal resin composition of the present embodiment, the oxyethylene unit-[(CH ₂ ) ₂ O]-and the oxytetramethylene unit-[(CH ₂ ) ₄ O ] -Preferably.

The content of the granular composition for polyacetal resin in the polyacetal resin composition of the present embodiment is preferably 0.01 to 10 parts by mass with respect to 100 parts by mass of the polyacetal resin.
It is more preferably 0.1 to 8 parts by mass, and further preferably 0.1 to 6 parts by mass.
When the content of the granular composition for polyacetal resin is 0.01 parts by mass or more, the effect of high thermal stability is obtained, and when it is 10 parts by mass or less, the mechanical strength of the polymer is maintained.

[Manufacturing method of polyacetal resin composition]
The polyacetal resin composition of the present embodiment can be produced by melt-kneading the granular composition for a polyacetal resin of the present embodiment and the polyacetal resin.
Melt kneading can be carried out using a kneader such as an extruder, a heating roll, a kneader, or a Banbury mixer, and kneading by an extruder is particularly preferable from the viewpoint of productivity.
The kneading temperature may follow a preferable processing temperature of the base resin, and as a guide, it is in the range of 140 to 260 ° C., preferably in the range of 180 to 230 ° C.

Since the granular composition for a polyacetal resin of the present embodiment is granular, the addition concentration can be increased with respect to the polyacetal resin without lowering the productivity. Taking advantage of these characteristics, in the method for producing a polyacetal resin composition of the present embodiment, 100 parts by mass of the polyacetal resin is masterbatched by using 0.1 to 50 parts by mass of the granular composition for the polyacetal resin. The target polyacetal resin composition can be obtained by melt-kneading the polyacetal resin and the masterbatch.
When an additive is mixed with a polyacetal resin and melt-kneaded multiple times, deterioration of the polyacetal resin and deterioration of the additive may occur. However, a master batch using a granular composition for a polyacetal resin is made of a polyacetal resin. It is possible to obtain a highly pure polyacetal resin composition without causing deterioration or deterioration of additives.
By making a masterbatch, it is possible to mix more additives and suppress the amount of formaldehyde generated from the molded product after molding.

Hereinafter, the present embodiment will be described in detail with reference to specific examples and comparative examples, but the present embodiment is not limited to the following examples.

The measurement methods for various characteristics are shown below.
[Characteristic measurement method]
((1) Measurement of loosened apparent specific gravity)
The measurement was performed using a powder tester (manufactured by Hosokawa Micron Co., Ltd .: powder tester TYPE PT-E) and a metal container having a volume of 100 mL.

((2) Measurement of average particle size)
The average particle size is 30 minutes by installing meshes with eye openings of 1700 μm, 1000 μm, 710 μm, 500 μm, 355 μm, 250 μm, 150 μm, 106 μm and 46 μm on a micro-type electromagnetic vibration sieve (manufactured by Tsutsui Rikagaku Kikai). Was performed, and the 50% diameter of the weight cumulative particle size distribution was measured as the average particle size.

((3) Evaluation of uniformity)
<Evaluation of uniformity of granular composition for polyacetal resin>
A polyethylene bag was installed under a vinyl chloride pipe having a height of 3 m and a diameter of 15 cm.
From the upper part, 1 kg of the granular composition for polyacetal resin measured in another polyethylene bag was dropped at once.
The granular composition for polyacetal resin accumulated in the polyethylene bag under the vinyl chloride pipe was measured at 10 points from the top, 10 points from the middle part, 10 points from the bottom, and 1.00 mg at random. It was measured with a nitrogen analyzer TN-2100H.
Percentages of the relative standard deviations of the values of each 30 nitrogen analyzes were calculated.
It was evaluated that the smaller the value, the higher the uniformity.
When it was larger than 10%, it was judged that the variation was large and the uniformity was insufficient.
<Evaluation of uniformity of polyacetal resin composition pellets>
Each time for 10 mg of each polyacetal resin composition pellet at the start of operation, that is, 10 minutes after the resin starts to come out from the die portion of the extruder, 1 hour, 2 hours, 3 hours, and the end of the operation. The measurement was performed 10 times each with a nitrogen analyzer TN-2100H manufactured by Mitsubishi Analytech.
Each measurement was performed 10 times, and the percentage of the relative standard deviation of the numerical values of the nitrogen analysis was calculated.
It was evaluated that the smaller the value, the higher the uniformity.
When it was larger than 10%, it was judged that the variation was large and the uniformity was insufficient.

((4) Measurement of foreign matter in polyacetal resin composition pellets)
Pellets containing foreign substances were visually selected with respect to 3 kg of polyacetal resin composition pellets.
Then, for each pellet, the size of the foreign matter contained in the pellet containing the foreign matter was measured with a caliper.
Then, 100 g of pellets was pressed at 200 ° C. at a pressure of 10 MPa for 5 minutes to prepare 10 molded pieces of 30 cm × 30 cm × about 1.2 mm, and the content of foreign matter was visually confirmed and evaluated according to the following criteria. ..
When there is a foreign substance of 1.0 mm or more: ×
When there is no foreign matter of 1.0 mm or more and there is foreign matter of 0.3 mm or more and less than 1.0 mm: △
If there is no foreign matter of 0.3 mm or more and there is a foreign matter of less than 0.3 mm, the number is counted and if there are 30 or more in total: ○
Other than the above: ◎

((5) Amount of formaldehyde generated in polyacetal resin composition pellets)
The amount of formaldehyde generated in the polyacetal resin composition pellets was measured as follows.
20.00 g of polyacetal resin composition pellets were placed in a Tedlar® bag having a valve, and nitrogen substitution was sufficiently performed. Then, 5.00 L of nitrogen was sealed in a Tedlar (registered trademark) bag. Then, a Tedlar (registered trademark) bag was placed in an oven having a sampling port penetrating the outside at the upper part of the inside, and the sampling bag was connected to the sampling port and then left at 80 ° C. for 3 hours.
Then, a DNPH (2,4-dinitrophenylhydrazine) cartridge was connected to the sampling port, the valve of the sampling bag was opened, and 4.00 L of the polyacetal resin composition was passed through the DNPH cartridge.
5 mL of acetonitrile was passed through the DNPH cartridge at a constant rate, and formaldehyde was collected in a 10 mL volumetric flask.
Then, it was scalpel-up to 10 mL with water and mixed thoroughly.
Dispense this mixed solution into a vial, use Shimadzu HPLC, use DNPH standard solution as the standard solution, use water / acetonitrile (52/48) as the separation solution, flow rate 1 mL / min, column temperature 40. It was quantified at ° C., and the formaldehyde generated per mass of the polyacetal resin composition pellet was measured in ppm.
The upper limit of measurement is 15 ppm or less, and if the upper limit of measurement is exceeded, O.D. D. (Measurement is not possible).
The measurement was carried out with pellets 10 minutes after the start of operation, 1 hour after the start of operation, 2 hours, 3 hours after the start of operation, and at the end of the operation, and the maximum value among them was described.

[Raw material for granular composition for polyacetal resin]
((A) Antioxidant)
A-1: Tetrakis [methylene-3- (3,5'-di-t-butyl-4'-hydroxyphenylpropionate)] methane Melting point 120 ° C.
A-2: Triethylene glycol-bis- [3- (3-t-butyl-5-methyl-4-hydroxyphenyl) propionate]
Melting point 77 ° C
A-3: Stearyl 3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate Melting point 53 ° C

((B) Nitrogen-containing compound)
B-1: Melamine B-2: Benzoguanamine B-3: Adipic acid dihydrazide B-4: 2-Methylbenzimidazole B-5: Sebacate dihydrazide B-6: Dodecanoic acid dihydrazide

((C) Fatty Acid Ester)
C-1: Ethylene glycol distearate C-2: Stearyl stearate

((D) Thermoplastic polymer)
D-1: Polyacetal D-2: Polyamide 66

((E) Fatty acid metal salt)
E-1: Calcium distearate E-2: Calcium di-12 hydroxystearate

((F) Inorganic filler)
F-1: Talc F-2: Calcium carbonate

[Method for Producing Granular Composition for Polyacetal Resin (I)]
A co-directional twin-screw extruder with a screw diameter of 30 mm was used. All screw shapes are full flight type, and the die of the resin outlet is open.
A predetermined material was selected from the above raw materials, and a granular composition for a polyacetal resin was produced by a twin-screw extruder.
Specifically, the raw material was put into a twin-screw extruder and operated under the conditions between a state in which the whole was not melted and a state in which the particles did not grow at all and passed through the extruder. During operation, the feed amount of the additive was increased when the raw material was about to melt, and conversely decreased when the raw material was not melted at all, and controlled.
While checking the state of the granular composition for polyacetal resin discharged from the discharge port of the twin-screw extruder, the barrel temperature of the extruder was set to 80 ° C. and the rotation speed was set to 30 rpm.
The obtained granular composition for polyacetal resin was placed in a sieve having a 10-mesh sieve on the top and a 35-mesh sieve on the bottom, and vibrated vigorously to separate the sieves.
What remained on the 10-mesh sieve was crushed and dropped onto the 35-mesh sieve.
The fine powder that had passed through the 35-mesh sieve was appropriately returned to the raw material supply side of the extruder and reused.
The temperature of the barrel was appropriately controlled in the range of 60 to 100 ° C. after confirming the discharged particles.

[Method for Producing Granular Composition for Polyacetal Resin (II)]
30 g of the raw material of the granular composition for polyacetal resin was placed in a 110 mL screw tube, and the mixture was stirred with a spatula while heating on a mantle heater stirrer.
During stirring, it was visually confirmed that the particle size of the additive increased, and the particles were made into granules.
This work was repeated as appropriate.

[Manufacturing method of polyacetal resin A]
A twin-screw self-cleaning type polymerization machine with a jacket capable of passing a heat medium was adjusted to 80 ° C.
Then, trioxane was 12 kg / hr, 1,3-dioxolane as a comonomer was 414.6 g / hr (4.2 mol% with respect to 1 mol of trioxane), and methylal as a chain transfer agent was 6.8 g / hr with respect to 1 mol of trioxane. Then, it was continuously added to the polymerization machine.
Further, as a polymerization catalyst, 38 g / hr of a cyclohexane solution of 1% by mass of boron trifluoride di-n-butyl etherate was continuously added to the polymerization machine to carry out the polymerization.
The form of polymerization was bulk polymerization.
The powder of the polyacetal copolymer discharged from the polymerization machine was put into a 0.1% aqueous solution of triethylamine to deactivate the polymerization catalyst.
The inactivated polyacetal copolymer was filtered through a centrifuge, washed, and dried at 140 ° C. to obtain a crude polyacetal resin.
A tetramethylammonium formate aqueous solution was used as a quaternary ammonium compound with respect to 100 parts by mass of the crude polyacetal resin, mixed at 20 ppm in terms of the amount of nitrogen atoms, and then supplied to a twin-screw screw extruder with a vent.
The unstable end portion of the polyacetal resin was decomposed at a set temperature of the extruder of 200 ° C. and a residence time of 5 minutes in the extruder.
The decomposed polyacetal copolymer at the unstable end portion was devolatile under the condition of a vent vacuum degree of 20 Torr, extruded as a strand from the die section of the extruder, and pelletized to obtain a polyacetal resin A.

[Manufacturing method of polyacetal resin composition]
The polyacetal resin produced as described above and the granular composition or additive for the polyacetal resin are added in accordance with the compositions shown in Tables 1 and 2 below so that the total amount of the 36 L stainless sealed tank is about 18 kg, and the tumbler mini TMC is added. Using -36S, the mixture was mixed for 15 minutes to obtain a mixture.
The mixture was dropped into the hopper of a twin-screw extruder installed 2 meters below.
The twin-screw extruder was set to 200 ° C., and a twin-screw extruder with a 30 mm vent having L / D = 30 was used.
The mixture was fed from the main feed port and melt-kneaded at a screw rotation speed of 100 rpm to obtain a polyacetal resin composition.

(Examples 1 to 12)
According to the above-mentioned "Method for producing a granular composition for a polyacetal resin (I)", a granular composition for a polyacetal resin was produced according to the composition shown in Table 1 below, and various evaluations were performed.
The evaluation results are shown in Table 1.

(Examples 13 and 14)
According to the above-mentioned "Method for producing a granular composition for a polyacetal resin (II)", a granular composition for a polyacetal resin was produced according to the composition shown in Table 1 below, and various evaluations were performed.
The evaluation results are shown in Table 1.

(Comparative Examples 1 to 12)
According to the composition shown in Table 2 below, the raw materials were placed in a polyethylene bag and hand-blended to produce additives, which were evaluated in various ways.
The evaluation results are shown in Table 2.

( Reference example 15)
A granular composition for a polyacetal resin was produced in the same manner as in Example 6 except that the 10-mesh sieve was replaced with a 5-mesh sieve, and various evaluations were performed.
The evaluation results are shown in Table 1.

( Reference example 16)
A granular composition for a polyacetal resin was produced in the same manner as in Example 7 except that the 10-mesh sieve was replaced with a 5-mesh sieve, and various evaluations were performed.
The evaluation results are shown in Table 1.

(Examples 17 to 28, Reference Examples 29 to 30)
The granular compositions for polyacetal resin produced in the above (Examples 1 to 14 and Reference Examples 15 to 16) were used as granular samples K-1 to K-16, respectively, and these and the materials shown in Table 3 below were used. To produce a polyacetal resin composition.
The evaluation results are shown in Table 3.

(Comparative Examples 13 to 22)
The additives produced in (Comparative Examples 1 to 12) described above were used as additive samples P-1 to P-12, respectively, and a polyacetal resin composition was produced using these and the materials shown in Table 4 below. The evaluation results are shown in Table 4.

The polyacetal resin composition using the granular composition for the polyacetal resin composition of the present invention can be used as a material in the fields of electrical and electronic materials, automobiles, various other industrial materials, food packaging, and parts materials. Has the above availability.

Claims (12)

At least one type of (A) antioxidant and
A nitrogen-containing compound having two or more nitrogen atoms in at least one (B) molecule,
The, containing,
The average particle size is 100 μm or more and 861 μm or less.
Granular composition for polyacetal resin. Loose apparent specific gravity is 0.3 or more and 0.8 or less.
The granular composition for a polyacetal resin according to claim 1. The melting point of the antioxidant (A) is 30 ° C. or higher.
The granular composition for a polyacetal resin according to claim 1 or 2. (C) Further containing a fatty acid ester,
The granular composition for a polyacetal resin according to any one of claims 1 to 3. (B) A nitrogen-containing compound having two or more nitrogen atoms in the molecule
At least one selected from the group consisting of imidazole compounds, aminotriazine compounds, triazole compounds, and hydrazide compounds.
The granular composition for a polyacetal resin according to any one of claims 1 to 4. The content of the (A) antioxidant is 20% by mass or more.
The granular composition for a polyacetal resin according to any one of claims 1 to 5. (D) Further containing a thermoplastic polymer (excluding polyamide compounds),
The granular composition for a polyacetal resin according to any one of claims 1 to 6. (E) Further containing an inorganic filler,
The granular composition for a polyacetal resin according to any one of claims 1 to 7. The granular composition for a polyacetal resin according to any one of claims 1 to 8.
Polyacetal resin and
, A polyacetal resin composition containing. With 100 parts by mass of polyacetal resin,
0.1 to 10 parts by mass of the granular composition for a polyacetal resin according to any one of claims 1 to 8.
The polyacetal resin composition according to claim 9, which comprises. The method for producing a polyacetal resin composition according to claim 10.
A method for producing a polyacetal resin composition, which comprises a step of melt-kneading the polyacetal resin and the granular composition for the polyacetal resin. 0.1 to 50 parts by mass of the granular composition for a polyacetal resin and the polyacetal resin 1
The process of melting and kneading 00 parts by mass to make a masterbatch,
After masterbatch, the process of melt-kneading the polyacetal resin and
The method for producing a polyacetal resin composition according to claim 11.