JP2002212384A - Polyacetal-based resin composition and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a polyacetal-based resin composition which can remarkably control the production of formaldehyde. SOLUTION: The polyacetal-based resin composition comprises (A) 100 pts.wt. of a polyacetal resin and (B) 0.001 to 100 pts.wt. of the condensate of a phenol compound with a basic nitrogen-containing compound and an aldehyde compound. The component (B) may be the condensate of phenol with an aminotriazine compound and formaldehyde. The polyacetal-based resin composition may contain an antioxidant, a heat-resistance stabilibizer, a processing stability, a weather (light) stabilizer, a colorant and the like.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a polyacetal-based resin composition in which the amount of formaldehyde generated is suppressed, a method for producing the same, and a molded article formed from the composition.

[0002]

2. Description of the Related Art Polyacetal resins have mechanical properties,
Because of its excellent fatigue resistance, friction and wear resistance, chemical resistance and moldability, automotive parts, electrical and electronic equipment parts, other precision machine parts, building materials and piping parts, living and cosmetic parts,
It is widely used in the field of medical parts and the like. However, with the expansion and diversification of applications, the demand for the quality thereof has been increasing. The characteristics required of the polyacetal-based resin are that the mechanical strength does not decrease in the processing steps such as the extrusion or molding step, that there is no deposit on the mold (mold deposit), and that long-term heating conditions (heat aging) , The mechanical properties are not reduced, and molding defects such as silver streaks and voids do not occur. One of the important factors of these phenomena is decomposition of the polymer upon heating. In particular, polyacetal resins are
Due to its chemical structure, it is inherently easily decomposed under a heated oxidizing atmosphere under acidic or alkaline conditions. Therefore, an essential problem of the polyacetal-based resin is to improve the thermal stability and suppress the generation of formaldehyde from a molding process or a molded product. Formaldehyde is chemically active and becomes formic acid by oxidation, which adversely affects heat resistance.When used for parts of electric and electronic equipment, metal contact parts are corroded or discolored by the attachment of organic compounds, resulting in poor contact. Is generated. Furthermore, formaldehyde itself pollutes the working environment in the parts assembling process and the living environment around the use of the final product.

[0003] In order to stabilize the chemically active terminal, a homopolymer is obtained by esterifying the terminal of the polymer by acetylation or the like. For a copolymer, trioxane and a cyclic ether or cyclic formal are used during polymerization. After copolymerizing with a monomer having a carbon bond,
There is known a method of decomposing and removing an unstable terminal to make an inactive stable terminal. However, at the time of heating, cleavage and decomposition of the main chain portion of the polymer also occur, and the prevention cannot be dealt with only by the above treatment, and the addition of an antioxidant and other stabilizers is practically essential. .

However, even if these stabilizers are blended, it is difficult to completely suppress the decomposition of the polyacetal-based resin, and in practice, melt processing in the extrusion or molding process for preparing the composition is required. At this time, heat and oxygen are exerted in the cylinder of the extruder or the molding machine, and the main chain is decomposed or formaldehyde is generated from the terminal which is not sufficiently stabilized, thereby deteriorating the working environment during extrusion molding. In addition, when molding is performed for a long time, fine powders and tars adhere to the mold (mold deposit), which reduces the work efficiency and is one of the biggest factors in lowering the surface condition of the molded product. I have. Further, degradation of the polymer causes a decrease in mechanical strength and discoloration of the resin. From such a point, great efforts have been made for polyacetal resins in search of more effective stabilizing formulations.

As antioxidants to be added to polyacetal resins, sterically hindered phenol compounds (hindered phenols) and sterically hindered amine compounds (hindered amines) are known, and melamine is used as another stabilizer. Alternatively, specific nitrogen-containing compounds such as derivatives thereof, polyamides and polyacrylamide derivatives, amidine compounds, alkali metal hydroxides and alkaline earth metal hydroxides, and organic or inorganic acid salts are used. Usually, antioxidants are used in combination with other stabilizers. However, even if such an additive is used, it is difficult to impart high stability to the polyacetal resin.

[0006] JP-A-52-59646 discloses a polyacetal copolymer which is free from coloring by improving the stability against heat and oxidizing atmosphere by adding an antioxidant, alkylene urethanes and urea to a polyacetal copolymer. A resin composition is disclosed. However, it is still difficult to significantly suppress the generation of formaldehyde only by adding an antioxidant and urea.

Japanese Unexamined Patent Publication (Kokai) No. 61-145245 discloses that, in order to improve the thermal stability of a polyacetal, the acetal polymer is made of an ionic copolymer of a low molecular weight copolymer of an α-olefin and an α, β-ethylenically unsaturated carboxylic acid. A molding composition containing a small amount of salt is disclosed. It also describes that cyanoguanidines, triazines, and the like are used as amidine-based stabilizers.

Japanese Patent Application Laid-Open No. 63-260949 discloses that a polyacetal resin is prepared by adding a hindered phenol, a metal salt of hydroxycarboxylic acid, a lubricant, a nitrogen-containing heat stabilizer (amidine compound such as melamine, cyanoguanidine, etc.), nucleation. A polyacetal molding composition to which an agent, an antistatic agent and the like are added is disclosed. In this document, the additives provide resistance to yellowing during heat aging, mechanical properties,
It improves processability, stability against ultraviolet light, and resistance to accumulation of static electricity.

However, in these documents, although heat stability, mechanical properties, moldability and the like can be improved, it is difficult to significantly suppress the generation of formaldehyde, and the additive oozes out of the molded article. Therefore, it cannot be added in large amounts.

On the other hand, in order to improve the properties of the polyacetal-based resin, a combination with another material may be considered. However, polyacetal resins have high crystallinity, so their affinity and compatibility with other materials are extremely small.For example, among various polymers, the degree of compatibility with phenol novolak resin has been recognized. (Polymer Transactions, Vol. 48, No. 7, pp. 443-447 (Jul., 1991)). JP-A-5-98039 discloses a biaxially stretched polyoxymethylene film composition comprising a polyoxymethylene polymer and a novolak-type phenol resin. However, even in this composition, although the stretching stability is improved, the generation of formaldehyde is not suppressed.

[0011]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a polyacetal-based resin composition capable of remarkably suppressing the formation of formaldehyde, a method for producing the same, and a molded article.

Another object of the present invention is to provide a resin composition capable of improving the thermal stability of a polyacetal resin, particularly the melt stability during molding, a method for producing the same, and a molded article.

Still another object of the present invention is to suppress the formation of formaldehyde even under severe conditions, to adhere decomposed substances to a mold, to exude decomposed substances from a molded article, and to form a molded article. It is an object of the present invention to provide a polyacetal-based resin composition that can suppress thermal deterioration, improve the quality of a molded article, and improve moldability, a method for producing the same, and a molded article.

[0014]

Means for Solving the Problems The present inventors have conducted intensive studies to achieve the above object, and as a result, when combined with a phenol resin modified with a basic nitrogen-containing compound, the heat stability, especially the melting during molding processing, While improving stability,
The inventors have found that generation of formaldehyde from a polyacetal resin can be suppressed, and completed the present invention.

That is, the polyacetal resin composition of the present invention comprises a polyacetal resin (A) and a condensate (B) of a phenol, a basic nitrogen-containing compound and an aldehyde. In the component (B), examples of the basic nitrogen-containing compound include cyclic basic nitrogen-containing compounds (for example, triazines), for example, aminotriazines. The component (B) may be obtained by reacting in the presence of a basic catalyst or an acidic catalyst (particularly a basic catalyst such as amines). The ratio of the component (B) is about 0.001 to 100 parts by weight, preferably about 0.01 to 50 parts by weight, based on 100 parts by weight of the component (A). The resin composition may further contain an antioxidant, a heat stabilizer, a processing stabilizer, a weather (light) stabilizer, a colorant, and the like.

The present invention also includes a method for producing a polyacetal resin composition by mixing the above components (A) and (B). The present invention also includes a molded article formed from the composition.

[0017]

DETAILED DESCRIPTION OF THE INVENTION [(A) Polyacetal resin]
A polyacetal resin is an oxymethylene group (—CH
A polymer compound having ₂ O-) as a main structural unit,
Polyacetal homopolymer or polyoxymethylene (for example, trade name “Delrin” manufactured by DuPont, USA, trade name “Tenac 4010” manufactured by Asahi Kasei Corporation), and polyacetal copolymer containing oxymethylene unit and comonomer unit ( For example, the product name is "Duracon" manufactured by Polyplastics Co., Ltd.). In the copolymer, the comonomer unit includes an oxyalkylene unit having about 2 to 6 (preferably about 2 to 4) carbon atoms (for example, an oxyethylene group (—CH ₂ C)
H ₂ O-), oxypropylene group, and oxytetramethylene group) include. The content of the comonomer unit is small, for example, 0.1% based on the whole polyacetal resin.
01 to 20 mol%, preferably 0.03 to 10 mol%
(E.g., 0.05 to 5 mol%), and more preferably from the range of about 0.1 to 5 mol%.

The polyacetal copolymer may be a copolymer composed of two components, a terpolymer composed of three components, or the like. Polyacetal copolymers include, in addition to random copolymers, block copolymers (eg,
JP-B-2-24307, manufactured by Asahi Kasei Kogyo Co., Ltd., trade names such as "Tenac LA" and "Tenac LM"), and graft copolymers. Further, the polyacetal resin may have a branched structure as well as a linear structure,
It may have a crosslinked structure. Further, the terminal of the polyacetal resin may be stabilized by, for example, esterification with a carboxylic acid such as acetic acid or propionic acid or an anhydride thereof, urethaneization with an isocyanate compound, etherification, or the like. The degree of polymerization, the degree of branching and the degree of crosslinking of the polyacetal resin are not particularly limited as long as they can be melt-molded. The molecular weight of the polyacetal resin is not particularly limited,
For example, a weight average molecular weight of 5,000 to 500,000,
Preferably it is about 10,000 to 400,000.

The polyacetal resin includes, for example, aldehydes (eg, formaldehyde, paraformaldehyde, acetaldehyde, etc.) and cyclic ethers (eg, trioxane, ethylene oxide, propylene oxide, butylene oxide, styrene oxide, cyclohexene oxide, It can be produced by polymerizing a cyclic formal (eg, diethylene glycol formal, 1,4-butanediol formal, etc.) and the like. Furthermore, as a copolymerization component, an alkyl or aryl glycidyl ether (for example, methyl glycidyl ether, ethyl glycidyl ether, phenyl glycidyl ether, naphthyl glycidyl ether, etc.), an alkylene or polyoxyalkylene glycol diglycidyl ether (for example, ethylene glycol diglycidyl) Ether, triethylene glycol diglycidyl ether, butanediol diglycidyl ether, etc.), alkyl or aryl glycidyl alcohol, cyclic ester (eg, β-propiolactone), and vinyl compound (eg, styrene,
Vinyl ether) can also be used.

[(B) Phenols and basic nitrogen content
Of aldehydes and compounds] as phenols
Is particularly limited as long as it is an aromatic compound having a hydroxyl group.
Not a low molecular weight or high molecular weight
No. For example, phenol, C _1-20Alkyl group (preferably
Is C_1-10Phenol substituted with an alkyl group) (for example,
Cresols such as p- and m-cresol;
Cresols such as silenol, ethylphenol,
Propyl phenol, butyl phenol, t-butyl phenol
Knol, octylphenol, nonylphenol, dode
Silphenol, etc.), cyanophenol, arylphen
Phenol (eg, phenylphenol, benzylpheno)
, Cumylphenol, etc.), biphenols (eg
For example, biphenols), bisphenols (for example,
Bisphenol A, Bisphenol F, Bisphenol
S), polyhydric phenols (for example, resorcin,
Coal), aminophenols (for example, aminophen
Naphthols), naphthols (eg, α-naphthol)
, Β-naphthol, etc.), novolak resins (for example,
Phenol novolak resin, cresol novolak tree
Fat, phenol phenylene aralkyl resin, phenol
Biphenyl aralkyl resin, phenol diphenyl acrylate
Tel aralkyl resin, naphthol phenylene aralkyl
And the like). In addition, phenols include
An alkylene oxide (for example, ethyl
Denatured with propylene oxide)
Phenols are also included. These phenols
Phenol or alkyl (C_1-4Alkyl) pheno
In particular, phenol such as phenol is preferred. These fenault
Can be used alone or in combination of two or more.

Examples of the basic nitrogen-containing compound include triazines, amines, amino acids, ureas, imidazolones, amidine derivatives, pyrroles, pyrimidines, hydrazines, pyrazoles, triazoles, amide compounds, urethane compounds. Compounds and imide compounds can be exemplified. Among these basic nitrogen-containing compounds, cyclic basic nitrogen-containing compounds, particularly triazines [aminotriazines, (iso) cyanuric acid or derivatives thereof, etc.] are preferable.

As the aminotriazines, 1,3,5-triazines having an amino group are usually used. For example, melamines [melamine, substituted melamine (C _1-4 alkylmelamine such as 2-methylmelamine, Guanylmelamine, etc.)], melamine condensates (melam, melem, melon, etc.), guanamines [guanamine; C _1-4 alkyl guanamine, such as methylguanamine; acylguanamine, such as acetoguanamine; benzoguanamine, phenylacetoguanamine, phthaloguanamine, etc. Aromatic guanamines such as cyclohexane guanamine; aliphatic guanamines such as succino diguanamine and azibodiguanamine; CTU guanamine (2,4,8,10
-Tetraoxaspiro (5.5) undecane-3,9-
Bis (2-ethylguanamine)); acryloganamin and the like]. Aminotriazines are methylol compounds (monomethylolmelamine, dimethylolmelamine, trimethylolmelamine, tetramethylolmelamine, pentamethylolmelamine, hexamethylolmelamine,
Derivatives such as dimethylol benzoguanamine or condensates thereof, and alkoxymethyl derivatives (eg, methylated methylol melamine, ethylated methylol melamine, butylated methylol melamine) may be used.

(Iso) cyanuric acid or a derivative thereof includes cyanuric acid; C _1-4 alkyl cyanurate such as methyl cyanurate and ethyl cyanurate; acyl cyanurate such as acetyl cyanurate; cyanuric chloride;
Isocyanuric acid; C _1-4 alkyl isocyanurate such as methyl isocyanurate and ethyl isocyanurate;
Allyl isocyanurate; 2-hydroxyethyl isocyanurate; 2-carboxylethyl isocyanurate; chlorinated isocyanuric acid;

The basic nitrogen-containing compound preferably has an amino group, and aminotriazines are particularly preferable.
Of the aminotriazines, melamines, guanamines (guanamine, acetoguanamine, benzoguanamine, etc.) are usually used, and melamine is particularly preferred.
When aminotriazines are used as the co-condensation component, a co-condensate can be easily obtained, and the generation of formaldehyde from the polyacetal resin can be significantly suppressed.

The ratio (molar ratio) of the phenols to the basic nitrogen-containing compound is the former / the latter = 1 / 0.01 to 1 /
7, preferably about 1 / 0.04 to 1/3, more preferably about 1 / 0.1 to 1/1.

The aldehydes include aliphatic aldehydes (formaldehyde, acetaldehyde, propionaldehyde, etc.), aromatic aldehydes (benzaldehyde,
Examples thereof include hydroxybenzaldehyde, phenylacetaldehyde and the like, and formaldehyde condensate (trioxane, paraformaldehyde and the like). Of these aldehydes, aliphatic aldehydes, especially formaldehyde, are preferred. These aldehydes can be used alone or in combination of two or more.

The component (B) is obtained by reacting the phenol, the basic nitrogen-containing compound, and the aldehyde. The component (B) is a phenol resin modified with a basic nitrogen-containing compound (hereinafter sometimes referred to as a modified phenol resin), and may be a resol type or a novolak type. The novolak type is preferred from the viewpoint of compatibility with the component ()). As the novolak-type modified phenolic resin, for example, a random phenol novolak-type resin in which the position of a methylene bond is random with respect to a phenolic hydroxyl group, a high ortho-novolak-type resin having many methylene bonds at an ortho position to the phenolic hydroxyl group ( For example, a resin having an ortho / para ratio of 1 or more) can be exemplified. Among these novolak-type modified phenol resins, monomer-less resins and dimer-less resins in which residual phenols are reduced are preferred. The component (B) is
It is preferred that it contains substantially no unreacted formaldehyde or methylol groups.

The condensation reaction between a phenol, a basic nitrogen-containing compound and an aldehyde is usually carried out in the presence or absence of at least one selected from a basic catalyst and an acidic catalyst. Examples of the basic catalyst include amines (aliphatic primary amines such as methylamine, ethylamine, ethanolamine and propanolamine; aliphatic secondary amines such as dimethylamine, diethylamine and diethanolamine); trimethylamine, triethylamine and triethanolamine. Such as aliphatic tertiary amines; hexamethylenetetramine and the like; metal hydroxides (such as hydroxides of alkali or alkaline earth metals such as sodium hydroxide, potassium hydroxide and barium hydroxide); Alkali or alkaline earth metal oxides such as sodium oxide, potassium oxide, barium oxide, etc.), metal carbonates (eg, alkali metal carbonates such as sodium carbonate and potassium carbonate),
Ammonia (water) can be exemplified. As the acidic catalyst,
Inorganic acids (hydrochloric acid, sulfuric acid, sulfonic acid, phosphoric acid, etc.) and organic acids (aliphatic carboxylic acids such as formic acid, acetic acid, etc .; aliphatic dicarboxylic acids such as oxalic acid, malonic acid, succinic acid, etc .; alicyclics, such as naphthenic acid Carboxylic acids; organic sulfonic acids such as p-toluenesulfonic acid and methanesulfonic acid), Lewis acids, and divalent metal salts (such as zinc acetate). Among these catalysts, amines (eg, triethylamine), ammonia (water), aliphatic dicarboxylic acids (eg, oxalic acid)
In particular, amines and ammonia (water) are preferable.

When a novolak-type modified phenolic resin is produced as a basic nitrogen-containing compound, it may be used under basic (weakly basic) or acidic conditions, particularly under weakly basic conditions (for example,
The reaction is preferably performed at a pH of about 7 to 10.

The ratio (molar ratio) of the total amount of phenols and basic nitrogen-containing compounds to aldehydes is the former / the latter = 1 / 0.2 to 1 / 1.2, preferably 1 / 0.4 to 1 / 0.2.
It is 1/1, preferably about 1 / 0.4 to 1 / 0.9.

The number average molecular weight of the component (B) is not particularly limited and is, for example, 300 to 50,000, preferably 300.
It can be selected from the range of about 10,000 to 10,000, more preferably about 300 to 8000. The component (B) also includes a modified form in which a phenolic hydroxyl group is glycidyl-etherified, or a (poly) alkylene oxide adduct in which an alkylene oxide (eg, ethylene oxide, propylene oxide, etc.) is added.

The preparation of the component (B) is described in
-253557, JP-A-10-279657, JP-A-2000-351822, DIC Technica
l Review No.3 / 1997, p.47. Also,
The component (B) has a trade name of “Phenolite” [for example, phenolite 7050 series (KA-7051, KA-7
052, KA-7052-L, KA-7054, KA-
7055-L etc.), Fenolite 7750 series (K
A-7751, KA-7752, KA-7754, KA
-7755 etc.) [Dai Nippon Ink Chemical Industry Co., Ltd.]
Available as The component (B) can be used alone or in combination of two or more.

The proportion of the component (B) is 0.01 to 300 parts by weight, preferably 0.05 to 200 parts by weight, more preferably 0.1 to 1 part by weight, per 100 parts by weight of the component (A).
It is about 00 parts by weight (particularly 0.1 to 50 parts by weight).
The proportion of the component (B) is, in terms of a basic nitrogen-containing compound,
0.001 to 100 parts by weight of component (A)
Parts by weight, preferably about 0.01 to 50 parts by weight, and more preferably about 0.05 to 30 parts by weight.

[Additives] The resin composition of the present invention contains an antioxidant, a heat stabilizer, a processing stabilizer, a weather (light) stabilizer,
An additive such as a coloring agent may be included. These additives are
They can be used alone or in combination of two or more.

(Antioxidant) Antioxidants include, for example,
Phenol, amine, phosphorus, sulfur, hydroquinone and quinoline antioxidants are included.

As phenolic antioxidants, hindered phenols, for example, 2,2'-methylenebis (4-methyl-6-t-butylphenol), 4,4 '
-Methylenebis (2,6-di-t-butylphenol)
2,6-di-t-butyl-p-cresol, 1,3,5
-Trimethyl-2,4,6-tris (3,5-di-t-
Butyl-4-hydroxybenzyl) benzene, 1,6-
Hexanediol-bis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], pentaerythritol tetrakis [3- (3,5-di-t-
Butyl-4-hydroxyphenyl) propionate],
Triethylene glycol-bis [3- (3-t-butyl-5-methyl-4-hydroxyphenyl) propionate], n-octadecyl-3- (4 ', 5'-di-t-
Butylphenyl) propionate, stearyl-2-
(3,5-di-t-butyl-4-hydroxyphenyl)
Propionate, 2-tert-butyl-6- (3-tert-butyl-5-methyl-2-hydroxybenzyl) -4-methylphenylacrylate, 4,4'-thiobis (3-methyl-6-tert-butylphenol) And the like.

As the amine-based antioxidants, hindered amines such as 4-methoxy-2,2,6,6-tetramethylpiperidine, 4-benzoyloxy-2,
2,6,6-tetramethylpiperidine, bis- (2,
2,6,6-tetramethyl-4-piperidyl) oxalate, 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, phenyl-1-naphthylamine, phenyl-2-naphthylamine, N, N'-diphenyl-
Examples include 1,4-phenylenediamine, N-phenyl-N'-cyclohexyl-1,4-phenylenediamine and the like.

Examples of the phosphorus antioxidant include triisodecyl phosphite, triphenyl phosphite, diphenyl isodecyl phosphite, 2,2-methylenebis (4,6-di-t-butylphenyl) octyl phosphite, Tris (2,4-di-t-butylphenyl) phosphite, tris (2-t-butylphenyl) phosphite, bis (2-t-butylphenyl) phenyl phosphite, tris [2- (1,1- Dimethylpropyl)
-Phenyl] phosphite, tris (2-t-butyl-
4-phenylphenyl) phosphite and the like.

Hydroquinone-based antioxidants include, for example, 2,5-di-t-butylhydroquinone, and quinoline-based antioxidants include, for example, 6-ethoxy-2,2,4-trimethyl- Examples include 1,2-dihydroquinoline, and examples of the sulfur-based antioxidant include dilauryl thiodipropionate.

These antioxidants can be used alone or in combination of two or more. Among these antioxidants, at least one selected from hindered phenols and hindered amines, particularly hindered phenols [for example, C _2-10 alkylenediol-bis [(di-branched C _3-6 alkylhydroxyphenyl)] Propionate], di or trioxy C _2-4 alkylene diol-bis [(di-branched C _3-6 alkylhydroxyphenyl) propionate], C _3-8 alkylene triol-bis [(di-branched C _3-6 alkylhydroxyphenyl) propionate And C _4-8 alkylenetetraol tetrakis [(dibranched C _3-6 alkylhydroxyphenyl) propionate] and the like] are preferred.

The proportion of the antioxidant is 0.01 to 5 parts by weight, preferably 0.05 to 2.5 parts by weight, more preferably 0.1 to 100 parts by weight based on 100 parts by weight of the polyacetal resin.
It can be selected from a range of about 1 part by weight.

(Heat Stabilizer) The heat stabilizer includes (a) a basic nitrogen-containing compound, (b) a metal salt of an organic carboxylic acid,
(C) alkali or alkaline earth metal compounds, (d) hydrotalcite, (e) zeolite, and the like.

(A) Basic Nitrogen-Containing Compound The basic nitrogen-containing compound includes a low-molecular compound and a high-molecular compound (nitrogen-containing resin).

Examples of the low molecular weight compound include aliphatic amines (monoethanolamine, diethanolamine, etc.), aromatic amines (aromatic secondary amines such as o-toluidine, p-toluidine, p-phenylenediamine, etc.) Tertiary amines), amide compounds (polycarboxylic amides such as malonamide, isophthalic diamide, p-aminobenzamide, etc.), hydrazine or derivatives thereof (hydrazines such as hydrazine, hydrazone, polycarboxylic hydrazide, etc.), amino Triazines [guanamine,
Acetoguanamine, benzoguanamine, succinoguanamine, adipoguanamine, phthaloguanamine, CTU-
Guanamines such as guanamine or derivatives thereof, melamine or derivatives thereof (melamine; melamine condensates such as melam, melem, melon, etc.)], uracil or derivatives thereof (uracil, uridine or the like), cytosines or derivatives thereof (cytosine, cytidine) Guanidine or a derivative thereof (acyclic guanidine such as guanidine or cyanoguanidine; a cyclic guanidine such as creatinine); urea or a derivative thereof [biuret, biurea, ethylene urea,
Acetylene urea, isobutylidene diurea, clotilidene diurea, condensates of urea and formaldehyde, hydantoins, substituted hydantoin derivatives (mono- or di-C _1- such as 1-methylhydantoin, 5-propylhydantoin, and 5,5-dimethylhydantoin) ₄ alkyl substituents;
Aryl-substituted products such as 5-phenylhydantoin and 5,5-diphenylhydantoin; alkylaryl-substituted products such as 5-methyl-5-phenylhydantoin);
Allantoin, substituted allantoin derivatives (eg, mono-, di- or tri-C _1-4 alkyl-substituted, aryl-substituted, etc.), metal salts of allantoin (eg, salts with metals of Group 3B of the Periodic Table such as allantoin dihydroxyaluminum), allantoin and Reaction products with aldehyde compounds (such as adducts of allantoin-formaldehyde), compounds of allantoin and imidazole compounds (such as allantoin-sodium-dl-pyrrolidone carboxylate), and organic acid salts].

Examples of the nitrogen-containing resin include amino resins (condensation resins such as guanamine resin, melamine resin, and guanidine resin) formed by reaction with formaldehyde;
Benzoguanamine-melamine resin, aromatic polyamine-
A co-condensation resin such as a melamine resin), an aromatic amine-formaldehyde resin (such as an aniline resin), and a polyamide resin [for example, nylon 3 (poly β-alanine), nylon 46, nylon 6, nylon 66, nylon 11,
Nylon 12, nylon MXD6, nylon 6-10,
Nylon 6-11, Nylon 6-12, Nylon 6-6
Homo- or copolymerized polyamides such as 6-610; substituted polyamides having a methylol group or an alkoxymethyl group, etc.],
Examples thereof include polyesteramide, polyamideimide, polyurethane, polyacrylamide, poly (N-vinylcarboxylic acid amide), and a copolymer of N-vinylcarboxylic acid amide with another vinyl monomer.

These basic nitrogen-containing compounds can be used alone or in combination of two or more. Among these basic nitrogen-containing compounds, guanamines (adipguanamine, CTU-guanamine, etc.), melamine or derivatives thereof (especially melamine or melamine condensates (melam, melem, etc.)), guanidine derivatives (cyanoguanidine, creatinine, etc.) ), Urea derivatives [biurea, condensates of urea and formaldehyde, allantoin, metal salts of allantoin (such as allantoin dihydroxyaluminum)],
Nitrogen-containing resin [amino resin (melamine resin, melamine-
Amino resin such as formaldehyde resin; cross-linked amino resin such as cross-linked melamine resin); and polyamide resin.

(B) Organic Carboxylic Acid Metal Salts Organic carboxylic acid metal salts include organic carboxylic acids and metals (eg, alkali metals such as Na and K; alkaline earth metals such as Mg and Ca; transition metals such as Zn). And salts thereof.

The organic carboxylic acids include saturated or unsaturated aliphatic carboxylic acids, polymers of unsaturated aliphatic carboxylic acids, and the like. Further, these aliphatic carboxylic acids may have a hydroxyl group.

The saturated aliphatic carboxylic acids include saturated C
_1-34 monocarboxylic acids (acetic acid, propionic acid, butyric acid, isobutyric acid, valeric acid, isovaleric acid, pivalic acid, caproic acid, caprylic acid, capric acid, lauric acid, myristic acid, pentadecylic acid, palmitic acid, stearic acid , Arachinic acid, behenic acid, montanic acid, etc.), saturated _C2-30 dicarboxylic acid (oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, corkic acid, azelaic acid, sebacic acid, dodecane diacid) , Tetradecandioic acid, tapsiaic acid), and their oxy acids (glycolic acid, lactic acid, glyceric acid, hydroxybutyric acid, citric acid, 12-hydroxystearic acid, etc.).

The unsaturated aliphatic carboxylic acids include unsaturated C _3-34 monocarboxylic acids [(meth) acrylic acid, crotonic acid, isocrotonic acid, myristoleic acid, palmitoleic acid, oleic acid, linoleic acid, linolenic acid, Arachidonic acid, erucic acid, etc.], unsaturated C _4-30 dicarboxylic acids (maleic acid, fumaric acid, decenedioic acid, dodecenedioic acid, etc.), and their oxy acids (propiolic acid, etc.).

Examples of the polymer of the unsaturated aliphatic carboxylic acid include a polymerizable unsaturated carboxylic acid [α, β-ethylenically unsaturated carboxylic acid, for example, a polymerizable unsaturated monocarboxylic acid such as (meth) acrylic acid, and the like. Polymerizable unsaturated polycarboxylic acids (such as itaconic acid, maleic acid, and fumaric acid), and acid anhydrides or monoesters of the polycarboxylic acids (such as mono-C _1-10 alkyl esters such as monoethyl maleate).
And olefins (such as α-C _2-10 olefins such as ethylene and propylene).

These metal salts of organic carboxylic acids can be used alone or in combination of two or more. Among these organic carboxylic acid metal salts, alkaline earth metal organic carboxylate (calcium acetate, calcium citrate, magnesium stearate, calcium 12-hydroxystearate, etc.), ionomer resin (the above-mentioned polymerizable unsaturated polycarboxylic acid) And a resin in which at least a part of the carboxyl group contained in the copolymer of olefin and olefin is neutralized by the metal ion. The ionomer resin is commercially available, for example, as A-CARYN (manufactured by Allied Signal), Himilan (manufactured by DuPont Mitsui Polychemicals), Surlyn (manufactured by DuPont), and the like.

(C) Alkali or alkaline earth metal compounds
Products Alkali or alkaline earth metal compounds include metal oxides
(CaO, MgO, etc.), metal hydroxide [Ca (OH)_Two,
Mg (OH)_TwoEtc.], metal inorganic acid salts [metal carbonates (Na_TwoC
O_Three, K_TwoCO_Three, CaCO_Three, MgCO_ThreeEtc.), metal hoes
Acid salt (Ca_Three(PO _Four)_TwoEtc.), metal phosphates (Mg_Three(B
O_Three)_TwoEtc.] etc. are included. These metal compounds
Can be used alone or in combination of two or more. this
Among these metal compounds, metal oxides and metal hydroxides,
Especially alkaline earth metal oxides and alkaline earth metal hydroxides
Are preferred.

(D) Hydrotalcite Hydrotalcite includes hydrotalcites described in JP-A-60-1241 and JP-A-9-59475, for example, represented by the following formula: Hydrotalcite compounds and the like can be used.

[M²⁺ _1-xM³⁺ _x(OH)_Two]^{x +}[A^n- _{x / n}・ M
H_TwoO]^x- [Where M²⁺Is Mg²⁺, Mn²⁺, Fe²⁺, Co²⁺Etc.
A valent metal ion, M ³⁺Is Al³⁺, Fe³⁺, Cr³⁺etc
Shows a trivalent metal ion. A^n-Is CO_Three ^2-, OH^-, HP
O_Four ^2-, SO_Four ^2-(An especially monovalent or divalent) anion such as
To indicate x is 0 <x <0.5, and m is 0 ≦ m
<1> Hydrotalcite may be used alone or in combination of two or more.
Can be used. In addition, hydrotalcite is referred to as “DHA
-4A "," DHA-4A-2 "," Alkamizer "
Available from Kyowa Chemical Industry Co., Ltd.

(E) Zeolite The zeolite is not particularly limited, but zeolites other than H type, for example, zeolites described in JP-A-7-62142 [the minimum unit cell is an alkali and / or alkaline earth metal Zeolite which is a crystalline aluminosilicate (A-type, X-type, Y-type, L-type and ZSM-type zeolite, mordenite zeolite; chabazite;
And natural zeolites such as mordenite and faujasite).

Zeolites can be used alone or in combination of two or more. The A-type zeolite is referred to as “Zeolam A-3”, “Zeolam A-4”, “Zeolam A-5” and the like, and the X-type zeolite is referred to as “Zeolam F-
9 "and Y-type zeolite are available from Tosoh Corporation as" HSZ-320NAA "or the like.

The heat stabilizers can be used alone or in combination of two or more. The heat stabilizer includes the component (a) and
When used in combination with at least one selected from the above components (b) to (e), heat resistance can be imparted with a small amount.

The ratio of the heat stabilizer is, for example, 0.001 to 10 parts by weight, preferably 0.001 to 5 parts by weight, more preferably 0.01 to 2 parts by weight, based on 100 parts by weight of the polyacetal resin. You can choose from a range of degrees.
When the component (a) and the component [(b) to (e)] are used in combination, the ratio of both is (a) / [(b) to
(E)] = 90/10 to 10/90, preferably 70 /
It is about 30 to 30/70.

(Processing Stabilizer) As the processing stabilizer,
(A) a long-chain fatty acid or a derivative thereof, (b) a polyoxyalkylene glycol, (c) a silicone compound,
(D) waxes and the like. And at least one selected from the group consisting of:

(A) Long chain fatty acid or derivative thereof The long chain fatty acid may be a saturated fatty acid or an unsaturated fatty acid. In addition, those in which some hydrogen atoms are substituted with a substituent such as a hydroxyl group can also be used. As such long-chain fatty acids, monovalent or divalent fatty acids having 10 or more carbon atoms, for example, monovalent saturated fatty acids having 10 or more carbon atoms [capric acid, lauric acid, myristic acid, pentadecyl acid, palmitic acid, Stearic acid, arachidic acid,
C _10-34 saturated fatty acids such as behenic acid and montanic acid (preferably C _10-26 saturated fatty acids) and the like], monovalent unsaturated fatty acids having 10 or more carbon atoms [oleic acid, linoleic acid, linolenic acid, arachidonic acid, C _10-34 unsaturated fatty acids such as erucic acid (preferably C _10-26 saturated fatty acids) and the like;
The above divalent fatty acids (dibasic fatty acids) [sebacic acid,
Divalent C _10-30 saturated fatty acids (preferably divalent C _10-20 saturated fatty acids) such as dodecandioic acid, tetradecandioic acid, and thapsiic acid; and divalent C10 such as decenedioic acid and dodecenedioic acid.
_10-30 unsaturated fatty acids (preferably divalent C _10-20 unsaturated fatty acids) and the like]. The fatty acids also include fatty acids having one or more hydroxyl groups in the molecule (e.g., hydroxy saturated _C10-26 fatty acids such as 12-hydroxystearic acid). These fatty acids can be used alone or in combination of two or more.

The derivatives of long-chain fatty acids include fatty acid esters and fatty acid amides. The structure of the long-chain fatty acid ester is not particularly limited, and any of a linear or branched fatty acid ester can be used. One or more esters of a long-chain fatty acid and an alcohol (eg, monoester, diester, triester, etc.) And an ester having an ester bond). The type of the alcohol constituting the long-chain fatty acid ester is not particularly limited, but a polyhydric alcohol is preferable. As the polyhydric alcohol, a polyhydric alcohol having about 2 to 8 carbon atoms, preferably about 2 to 6 carbon atoms, or a polymer thereof, for example, an alkylene glycol [for example, C _2-8 alkylene such as ethylene glycol, diethylene glycol, propylene glycol and the like] Glycol (preferably C _2-6 alkylene glycol)], triols such as glycerin, trimethylolpropane or derivatives thereof, tetraols such as pentaerythritol, sorbitan or derivatives thereof, and the like. Examples thereof include homo- or copolymers of polyhydric alcohols (for example, homo- or copolymers of polyoxyalkylene glycol such as polyethylene glycol and polypropylene glycol, and polyglycerin). The average polymerization degree of the polyalkylene glycol is 2 or more (for example, 2 to 500), preferably about 2 to 400 (for example, 2 to 300), and the average polymerization degree is 16 or more (for example, about 20 to 200). Such a polyalkylene glycol is suitably used as an ester with a fatty acid having 12 or more carbon atoms. Preferred polyhydric alcohols are polyalkylene glycols having an average degree of polymerization of 2 or more. These polyhydric alcohols can be used alone or in combination of two or more.

Examples of such fatty acid esters include:
Ethylene glycol distearate, glycerin monostearate, glycerin tripalmitate, polyglycerin tristearate, trimethylolpropane monopalmitate, pentaerythritol monoundecylate,
Sorbitan monostearate, polyalkylene glycol (polyethylene glycol, polypropylene glycol, etc.) monolaurate, monopalmitate, monostearate, dilaurate, dipalmitate, distearate, dibehenate, dimontanate,
And dioleate and dilinoleate. These fatty acid esters can be used alone or in combination of two or more.

As the fatty acid amide, an acid amide (monoamide, bisamide, etc.) of the above long-chain fatty acid (monovalent or divalent long-chain fatty acid) with an amine (monoamine, diamine, polyamine, etc.) can be used. Examples of the monoamide include, for example, primary acid amides of saturated fatty acids such as capric acid amide, lauric acid amide, myristic acid amide, palmitic acid amide, stearic acid amide, arachidic acid amide, and behenic acid amide, and oleic acid amides. Saturation of saturated fatty acids such as primary acid amide, stearyl stearamide, stearyl oleamide and / or the like;
Or, a secondary acid amide of an unsaturated fatty acid and a monoamine can be exemplified. Of these fatty acid amides, bisamides are preferred. The bisamide, C _1-6 alkylenediamine (particularly, C _{1 -2} alkylenediamine) contains such bisamide and the fatty acid, and specific examples thereof include ethylenediamine - distearate amide (ethylenebisstearylamide), hexa Methylenediamine-distearic acid amide, ethylenediamine-dioleic acid amide, ethylenediamine-dierucamide and the like, and further ethylenediamine- (stearic acid amide)
Bisamides having a structure in which a different acyl group is bonded to an amine moiety of an alkylenediamine such as oleic acid amide can also be used. In the acid amide, the fatty acid constituting the acid amide is preferably a saturated fatty acid. These fatty acid amides can be used alone or in combination of two or more.

[0065] The (b) a polyoxyalkylene glycol polyoxyalkylene glycols, alkylene glycol [such as ethylene glycol, propylene glycol, C _2-6 alkylene glycols such as tetramethylene glycol (preferably a C _2-4 alkylene glycol), such as ], A homopolymer, a copolymer, a derivative thereof and the like. Specific examples include poly C _2-6 oxyalkylene glycol (preferably poly C _2-4 oxyalkylene glycol) such as polyethylene glycol, polypropylene glycol, and polytetramethylene glycol, and polyoxyethylene-polyoxypropylene copolymer (random). Or a block copolymer), polyoxyethylene polyoxypropylene glyceryl ether,
And polyoxyethylene polyoxypropylene monobutyl ether.

These polyoxyalkylene glycols can be used alone or in combination of two or more. Among these polyoxyalkylene glycols, polymers having oxyethylene units, for example, polyethylene glycol, polyoxyethylene polyoxypropylene copolymer and derivatives thereof are preferable. The number average molecular weight of the polyoxyalkylene glycol is 1 × 1
0 ³ to 1 × 10 ⁶ (for example, 1 × 10 ^{3 to} 5 × 10 ⁵ ), preferably 2 × 10 ³ to 1 × 10 ⁵ (for example, 2 × 10 ³ to ⁵ )
It is about 5 × 10 ⁴ ).

(C) Silicone Compound The silicone compound includes (poly) organosiloxane and the like. Examples of the (poly) organosiloxane include monoorganosiloxanes such as dialkylsiloxanes (eg, dimethylsiloxane), alkylarylsiloxanes (eg, phenylmethylsiloxane), diarylsiloxanes (eg, diphenylsiloxane), and homopolymers thereof. (For example, polydimethylsiloxane, polyphenylmethylsiloxane, etc.) or a copolymer. In addition, (poly) organosiloxane includes modified (poly) organosiloxane (for example, modified silicone) having a substituent such as an epoxy group, a hydroxyl group, a carboxyl group, an amino group, or an ether group at a molecular terminal or a main chain. Is also included. These silicone compounds can be used alone or in combination of two or more.

(D) Waxes The waxes include polyolefin-based waxes and the like. Examples of the polyolefin wax include poly C _2-4 olefin wax such as polyethylene wax and polypropylene wax, and olefin copolymer wax such as ethylene copolymer wax, and also include partial oxides or mixtures thereof. Examples of the olefin copolymer include olefins (ethylene, propylene, 1-
Butene, 2-butene, isobutene, 3-methyl-1-butene, 4-methyl-1-butene, 2-methyl-2-butene, 4-methyl-1-pentene, 1-hexene, 2,3
Α-olefins such as -dimethyl-2-butene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-dodecene, etc.) and monomers copolymerizable with these olefins, , Unsaturated carboxylic acids or acid anhydrides thereof [maleic anhydride, (meth) acrylic acid, etc.],
(Meth) acrylic acid ester [(meth) acrylic acid such as methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate And a polymerizable monomer such as C _1-10 alkyl (preferably C _1-4 alkyl) ester. Also,
These copolymers include a random copolymer, a block copolymer, or a graft copolymer. The olefin copolymer wax is generally a copolymer of ethylene and at least one monomer selected from other olefins and polymerizable monomers.

These waxes can be used alone or in combination of two or more. Of these waxes,
Polyethylene wax is preferred. The number average molecular weight of the wax is from 100 to 20,000, preferably from 500 to 1.
5000, more preferably about 1,000 to 12,000.

The processing stabilizers can be used alone or in combination of two or more. The proportion of the processing stabilizer is 0.01 to 10 parts by weight, based on 100 parts by weight of the polyacetal resin.
Preferably 0.03 to 5 parts by weight (for example, 0.05 to 3 parts by weight)
Parts by weight), particularly about 0.05 to 2 parts by weight.

(Weather (light) Stabilizer) Examples of the weather (light) stabilizer include (a) a benzotriazole compound, (b) a benzophenone compound, (c) an aromatic benzoate compound, and (d) a cyanoacrylate compound. Compounds, (e) oxalic anilide compounds, (f) hindered amine compounds, and the like.

(A) Benzotriazole-based compounds Examples of benzotriazole-based compounds include 2- (2'-hydroxy-5'-methylphenyl) benzotriazole and 2- (2'-hydroxy-3 ', 5'-di- t-butylphenyl) benzotriazole, 2- (2'-hydroxy-3 ', 5'-di-t-amylphenyl) benzotriazole, 2- (2'-hydroxy-3', 5'-
Benzotriazoles having a hydroxyl group and an alkyl (C _1-6 alkyl) group-substituted aryl group such as di-isoamylphenyl) benzotriazole; 2- [2′-hydroxy-3 ′, 5′-bis (α, α- Benzotriazoles having a hydroxyl group such as dimethylbenzyl) phenyl] benzotriazole and an aryl group substituted with an aralkyl (or aryl) group; hydroxyl groups and alkoxy such as 2- (2'-hydroxy-4'-octoxyphenyl) benzotriazole (C _1-12 alkoxy)
Benzotriazoles having a group-substituted aryl group are exemplified. These benzotriazole compounds can be used alone or in combination of two or more. Among these benzotriazole compounds, a hydroxyl group and C
Benzotriazoles having _3-6 alkyl substituted C _6-10 aryl (especially phenyl) groups, and hydroxyl groups and C _6-10 aryl-C _1-6 alkyl (especially phenyl-
Benzotriazoles having a C _1-4 alkyl) -substituted aryl group.

(B) Benzophenone Compounds Benzophenone compounds include benzophenones having a plurality of hydroxyl groups (di to tetrahydroxybenzophenone such as 2,4-dihydroxybenzophenone; hydroxyl such as 2-hydroxy-4-oxybenzylbenzophenone). Groups and benzophenones having a hydroxyl-substituted aryl or aralkyl group);
Benzophenones having a hydroxyl group and an alkoxy (C _1-16 alkoxy) group (2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-octoxybenzophenone, 2-hydroxy-4-dodecyloxybenzophenone, 2,2 ′ -Dihydroxy-4-methoxybenzophenone, 2,2'-dihydroxy-4,4 '
-Dimethoxybenzophenone, 2-hydroxy-4-methoxy-5-sulfobenzophenone, etc.). These benzophenone compounds can be used alone or in combination of two or more. Among these benzophenone-based compounds, benzophenones having a hydroxyl group-substituted C _6-10 aryl (or C _6-10 aryl-C _1-4 alkyl) group together with a hydroxyl group, in particular, a hydroxyl group-substituted phenyl-C with a hydroxyl group Benzophenones having a _1-2 alkyl group are preferred.

(C) Aromatic benzoate-based compound Examples of the aromatic benzoate-based compound include alkylaryl salicylates such as pt-butylphenyl salicylate and p-octylphenyl salicylate. The aromatic benzoate compounds can be used alone or in combination of two or more.

(D) Cyanoacrylate compound As the cyanoacrylate compound, 2-ethylhexyl-2-cyano-3,3-diphenylacrylate,
Examples include cyano group-containing diaryl acrylates such as ethyl-2-cyano-3,3-diphenyl acrylate. The cyanoacrylate compounds can be used alone or in combination of two or more.

(E) Oxalic acid anilide compound N- (2-ethylphenyl) -N '-(2-ethoxy-5-t-butylphenyl) oxalic acid diamide, N- ( Examples thereof include oxalic acid diamides having an aryl group which may be substituted on a nitrogen atom, such as 2-ethylphenyl) -N '-(2-ethoxy-phenyl) oxalic acid diamide. The oxalic acid anilide compounds can be used alone or in combination of two or more.

(F) Hindered amine compound As the hindered amine compound, a piperidine derivative having a sterically hindered group, for example, an ester group-containing piperidine derivative [4-acetoxy-2,2,6,6-tetramethylpiperidine, 4- Stearoyloxy-2,2,
Aliphatic acyloxypiperidines such as 6,6-tetramethylpiperidine and 4-acryloyloxy-2,2,6,6-tetramethylpiperidine (such as _C2-20 aliphatic acyloxy-tetramethylpiperidine); 4-benzoyloxy- Aromatic acyloxypiperidines such as 2,2,6,6-tetramethylpiperidine (such as _C7-11 aromatic acyloxy-tetramethylpiperidine);
2,6,6-tetramethyl-4-piperidyl) oxalate, bis (2,2,6,6-tetramethyl-4-piperidyl) malonate, bis (2,2,6,6-tetramethyl-4-piperidyl) ) Adipate, bis (1, 2,
2,6,6-pentamethyl-4-piperidyl) adipate, bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, bis (1,2,2,6,6-pentamethyl-4-piperidyl) ) Aliphatic di- or tricarboxylic acid-bis or tripiperidyl esters such as sebacate (such as _C2-20 aliphatic dicarboxylic acid-bispiperidyl ester); bis (2,2,6,6-tetramethyl-4-piperidyl) terephthalate , Tris (2,2,6,6-
Tetramethyl-4-piperidyl) benzene-1,3,5
-Aromatic di to tetracarboxylic acid-bis to tetraxiperidyl esters (such as aromatic di- or tricarboxylic acid-bis or tripiperidyl esters) such as tricarboxylate], ether group-containing piperidine derivatives [4-methoxy-2,2 , 6,6-C _1-10 alkoxy piperidine such as tetramethylpiperidine (C _1-6 alkoxy - tetramethyl piperidine); such as 4-cyclohexyloxy-2,2,6,6-tetramethylpiperidine C _{5- 8-} cycloalkyloxy-piperidine; 4-
Aryloxypiperidines such as phenoxy-2,2,6,6-tetramethylpiperidine; C _6-10 such as 4-benzyloxy-2,2,6,6-tetramethylpiperidine
Aryl-C _1-4 alkyloxy-piperidine and the like;
Alkylenedioxybispiperidines (such as C _1-10 alkylenedioxy-bispiperidine) such as 1,2-bis (2,2,6,6-tetramethyl-4-piperidyloxy) ethane and the like; amide group-containing piperidine Derivative [4-
Carbamoyloxypiperidine such as (phenylcarbamoyloxy) -2,2,6,6-tetramethylpiperidine; bis (2,2,6,6-tetramethyl-4-piperidyl) hexamethylene-1,6-dicarbamate Of carbamoyloxy-substituted alkylenedioxy-bispiperidine, etc.]. Further, a high-molecular-weight piperidine derivative polycondensate (dimethyl succinate-1- (2
-Hydroxyethyl) -4-hydroxy-2,2,6
6-tetramethylpiperidine polycondensate). These hindered amine compounds can be used alone or in combination of two or more.

Among these hindered amine compounds, ester group-containing piperidine derivatives, particularly, piperidyl esters of aliphatic carboxylic acids (preferably C _2-16 aliphatic dicarboxylic acid-bispiperidyl esters, more preferably C _6-14 aliphatic compounds) Dicarboxylic acid-bistetramethylpiperidyl ester), aromatic di- or tricarboxylic acid-
Bis or trispiperidyl ester is preferred.

The weather (light) stabilizers can be used alone or in combination of two or more. The proportion of weather (light) stabilizer is
0.01 to 100 parts by weight of polyacetal resin
It is about 5 parts by weight, preferably about 0.01 to 2 parts by weight, and more preferably about 0.1 to 2 parts by weight. Also, weather resistance (light)
As the stabilizer, it is preferable to use the component (f) in combination with at least one selected from the other components (a) to (e),
In particular, it is preferable to use (a) a benzotriazole compound and (f) a hindered amine compound in combination. In this case, the ratio (weight ratio) of the component (f) and the components [(a) to (e)] is the former / the latter = 0/100 to 80/20,
It is preferably about 10/90 to 70/30, and more preferably about 20/80 to 60/40.

(Colorant) As the colorant, various dyes or pigments can be used. The dye is preferably a solvent dye,
Examples include azo dyes, anthraquinone dyes, phthalocyanine dyes, and naphthoquinone dyes. As the pigment, any of an inorganic pigment and an organic pigment can be used.

Examples of the inorganic pigments include titanium pigments, zinc pigments, carbon black (furnace black, channel black, acetylene black, ketjen black, etc.), iron pigments, molybdenum pigments, cadmium pigments, lead pigments, Examples thereof include a cobalt-based pigment and an aluminum-based pigment.

Examples of the organic pigment include azo pigments, anthraquinone pigments, phthalocyanine pigments, quinacridone pigments, perylene pigments, perinone pigments, isoindoline pigments, dioxazine pigments, and sulene pigments. .

The coloring agents can be used alone or in combination of two or more. When a coloring agent having high light shielding effect [carbon black, titanium white (titanium oxide), phthalocyanine-based pigment], particularly carbon black, among these coloring agents, weather resistance (light) can be improved.

The proportion of the colorant is, for example, 0 to 5 parts by weight (for example, 100 parts by weight of the polyacetal resin).
0.01 to 5 parts by weight), preferably 0.1 to 4 parts by weight,
More preferably, it is about 0.1 to 2 parts by weight.

(Other Additives) The polyacetal resin composition of the present invention may contain, if necessary, conventional additives such as a releasing agent, a nucleating agent, an antistatic agent, a slidability improving agent, An impact modifier, a flame retardant, a surfactant, various polymers (for example, an olefin resin, a polyester resin, a urethane resin, and the like), a filler, and the like may be added alone or in combination of two or more. Also, if necessary, a resin having excellent weather resistance (light) resistance, for example, an acrylic resin [homologous or copolymer of C _1-10 alkyl (meth) acrylate such as polymethyl methacrylate], an acrylic core-shell polymer, A polycarbonate resin or the like may be added.

[Production Method of Polyacetal Resin Composition] The polyacetal resin composition of the present invention may be a powdery or granular mixture or a molten mixture.
It can be prepared by mixing the component (B) and, if necessary, other additives with a conventional method. For example, (1) a method in which the components are mixed, kneaded and extruded with a single-screw or twin-screw extruder to prepare pellets, and then molded, (2) a pellet (master batch) having a once different composition is prepared. A method of mixing (diluting) the pellets in a predetermined amount and subjecting the mixture to molding to obtain a molded body having a predetermined composition can be adopted.

The resin composition of the present invention can be prepared by a conventional molding method,
For example, injection molding, extrusion molding, compression molding, blow molding,
It is useful for molding various molded articles by a method such as vacuum molding, foam molding, rotational molding, and gas injection molding.

[Molded Article] The polyacetal-based resin molded article of the present invention composed of the above-mentioned polyacetal-based resin composition contains the component (A) and the component (B) in combination, and has stable weather (light) stability. Excellent formability and extremely low formaldehyde generation. That is, a molded article made of a conventional polyacetal resin containing a stabilizer such as an antioxidant generates a relatively large amount of formaldehyde, and contaminates a living environment and a working environment in addition to corrosion and discoloration. For example, the amount of formaldehyde generated from a commercially available polyacetal-based resin molded product is ^{2 to} 5 per 1 cm ^{2 of} surface area in a dry system (under a constant temperature drying atmosphere).
μg, and in a wet method (under a constant temperature and humid atmosphere)
It is about 3 to 6 μg per 1 cm ^{2 of} surface area.

On the other hand, in the polyacetal-based resin molded article of the present invention, the amount of formaldehyde generated is ² μg or less per 1 cm ² of surface area of the molded article (0 to 1.
About 5 μg), preferably about 0 to 1 μg, more preferably about 0 to 0.8 μg, and usually 0.01 to 0.7 μg.
It is about μg. In the wet method, the amount of formaldehyde generated is 3 μg or less (about 0 to 2.5 μg), preferably 0 to ² μg, more preferably about 0 to 1.7 μg, and usually about 0 to 1.7 μg per 1 cm ² of the surface area of the molded body.
It is about 1 to 1.5 μg.

The polyacetal resin molded article of the present invention
It is sufficient that the amount of formaldehyde generated is at least one of the dry type and the wet type. Usually, both the dry type and the wet type have the formaldehyde generated amount.

The amount of formaldehyde generated in a dry system can be measured as follows.

After cutting the polyacetal-based resin molded product as required and measuring the surface area, an appropriate amount of the molded product (for example, about 10 to 50 cm ² in surface area) is placed in a closed container (capacity: 20 ml), and the temperature is measured. Leave at 80 ° C. for 24 hours. After that, 5 ml of water is poured into this closed container,
The amount of formalin in this aqueous solution was determined according to JIS K0102,29.
(Formaldehyde), the amount of formaldehyde generated per surface area of the molded body (μg / cm ² )
Ask for.

Further, the amount of formaldehyde generated in a wet system can be measured as follows.

After the polyacetal-based resin molded product is cut as necessary and the surface area is measured, an appropriate amount of the molded product (for example, a surface area of about 10 to 100 cm ² ) is measured.
It is hung on the lid of a sealed container (volume: 1 L) containing 50 ml of distilled water, sealed, and left in a thermostat at a temperature of 60 ° C. for 3 hours.
Thereafter, the mixture is allowed to stand at room temperature for 1 hour, and the amount of formalin in the aqueous solution in the closed container is quantified in accordance with JIS K0102, 29 (formaldehyde) to determine the amount of formaldehyde generated (μg / cm ² ) per surface area of the molded product.

The numerical definition of the amount of formaldehyde generated in the present invention includes conventional additives (ordinary antioxidants, stabilizers, coloring agents, etc.) as long as the components (A) and (B) are included. Most of the surface (for example, 50 to 100%) of the surface of the molded product of the polyacetal-based resin composition is not limited to the molded product of the polyacetal-based resin composition, but also the molded product of the composition containing an inorganic filler, another polymer, and the like. (For example, a multi-colored molded article, a coated molded article, and the like).

The molded article of the present invention can be used in any application where formaldehyde is detrimental (for example, knobs and levers as bicycle parts), but it can be used for automobile parts and electric / electronic parts (active parts and passive parts). Parts), building materials / piping parts, daily necessities (life) / cosmetic parts, and medical (medical / medical) parts.

More specifically, automotive parts include inner handles, fuel trunk openers, seat belt buckles, assist wraps, various switches, knobs, levers, clips, interior parts such as speaker grills, and electric parts such as meters and connectors. System parts, in-vehicle electric and electronic parts such as audio equipment and car navigation equipment, parts that come into contact with metals represented by the carrier plate of window regulators, door lock actuator parts, mirror parts, wiper motor system parts, fuel system parts And other mechanical components.

As electric / electronic parts (mechanical parts), parts or members of equipment made of a polyacetal resin molding and having many metal contacts [for example, audio equipment such as a cassette tape recorder, VTR (video tape) Recorders), video equipment such as 8mm video and video cameras, or OA (office automation) equipment such as copiers, facsimile machines, word processors, computers, etc., as well as toys, telephones, computers, etc., which are driven by driving power such as motors and splicers. And the like attached to the keyboard). Specific examples include a chassis (base), gears, levers, cams, pulleys, bearings, and the like. Furthermore, optical and magnetic media components (for example, metal thin film type magnetic tape cassettes, magnetic disk cartridges, magneto-optical disk cartridges, etc.) at least partially composed of a polyacetal-based resin molded product, and more specifically, metal tape cassettes for music , Digital audio tape cassette, 8 mm video tape cassette, floppy (registered trademark) disk cartridge, mini disk cartridge and the like. Specific examples of optical and magnetic media components include tape cassette components (tape cassette body, reel, hub,
Guides, rollers, stoppers, lids, etc.), disk cartridge parts (disk cartridge body (case), shutters, clamping plates, etc.).

Further, the polyacetal-based resin molded article of the present invention can be used for building materials and piping parts such as lighting fixtures, fittings, pipes, cocks, faucets, toilet peripheral parts, stationery, lip cream / lipstick containers, washing machines, water purifiers. It is suitably used for a wide range of life-related parts, cosmetic parts, and medical parts, such as spray nozzles, spray containers, aerosol containers, general containers, and injection needle holders.

[0100]

Since the polyacetal resin composition of the present invention contains a condensate of a phenol, a basic nitrogen-containing compound and an aldehyde, it has improved heat stability, especially melt stability during molding. In addition, the amount of formaldehyde generated from the polyacetal resin and the molded article can be suppressed to an extremely low level, and the surrounding environment (work environment, use environment, etc.) can be greatly improved. Furthermore, even under severe conditions, the formation of formaldehyde can be suppressed, decomposition products and additives adhere to the mold (mold deposit),
It is possible to suppress leaching of resin decomposition products and additives from the molded body and thermal deterioration of the molded body, and improve the quality and moldability of the molded body.

[0101]

EXAMPLES The present invention will be described below in more detail with reference to Examples, but the present invention is not limited to these Examples.

In Examples and Comparative Examples, the moldability (the amount of deposits on the mold) and the amount of formaldehyde generated from the dry and wet compacts were evaluated as follows. The polyacetal resin, modified phenolic resin, antioxidant, heat stabilizer, processing stabilizer, weather (light) stabilizer and colorant used in Examples and Comparative Examples are as follows.

[Moldability (Amount of Die Attached)] A molded article having a specific shape (diameter: 20 mm × thickness: 1 mm) was continuously molded from a pellet formed from the polyacetal resin composition by using an injection molding machine (1000 mm). Shots), and the degree of adhesion to the mold was evaluated on a five-point scale. It should be noted that the smaller the number, the smaller the amount of deposits on the mold, that is, the smaller the amount of mold deposit.

[Amount of Formaldehyde Generated from Molded Product in Dry Process] Ten test pieces (2 mm × 2 mm × 50 mm) (total surface area: about 40 cm ² ) of resin samples were placed in a closed container (capacity: 20 ml), and the temperature was 80 ° C. After heating in a thermostat for 24 hours, the mixture was air-cooled to room temperature, and 5 ml of distilled water was injected with a syringe. The amount of formaldehyde in this aqueous solution was quantified according to JIS K0102,29 (formaldehyde), and the amount of formaldehyde gas generated per surface area (μg / cm ² ) was calculated.

[Amount of Formaldehyde Emitted from Wet Molded Body] Flat molded body (120 mm × 120 mm × 2 m
m) to obtain a test piece (100 mm × 40
mm × 2 mm; total surface area 85.6 cm ² ) with distilled water 50
ml of polyethylene bottle (capacity: 1 L), which was hung on a lid and hermetically sealed, and left in a thermostat at a temperature of 60 ° C. for 3 hours.
It was left at room temperature for 1 hour. The amount of formalin in the aqueous solution in the polyethylene bottle was determined according to JIS K0102, 29 (formaldehyde), and the amount of formaldehyde generated per surface area (μg / cm ² ) was calculated.

[Polyacetal resin A] A-1: Polyacetal resin copolymer (melt hydrolysis stabilized resin, melt index = 9 g / 10 min) A-2: Polyacetal resin copolymer (solution hydrolyzed resin, melt index) = 9 g / 10 min) The melt index was measured using ASTM-D123.
This is a value (g / 10 minutes) determined under the conditions of 190 ° C. and 2169 g according to 8.

[Modified phenolic resin B] B-1 to B-5: Modified phenolic resin obtained by the following Synthesis Examples 1 to 5 B-6: Aminotriazine-modified phenolic resin [manufactured by Dainippon Ink and Chemicals, Inc. Phenolite KA-7054
(Nitrogen content: 12% by weight, softening point: 132 ° C)] B'-1: Unmodified phenolic resin obtained according to Synthesis Example 6 below.

[Antioxidant C] C-1: Triethylene glycol-bis [3- (3-t)
-Butyl-5-methyl-4-hydroxyphenyl) propionate] C-2: pentaerythritol tetrakis [3- (3,
5-Di-t-butyl-4-hydroxyphenyl) propionate] [Irganox 1010, manufactured by Ciba-Geigy Corporation].

[Heat-resistant stabilizer D] D-1: melamine D-2: melamine formaldehyde resin A reaction was carried out at pH 8 and a temperature of 70 ° C. in an aqueous solution using 1.2 mol of formaldehyde with respect to 1 mol of melamine. Melamine-water-soluble precondensate without clouding
A formaldehyde resin was formed. Next, the reaction system was adjusted to pH 6.5 while stirring, and stirring was continued to precipitate a melamine-formaldehyde resin, followed by drying to obtain a crude melamine-formaldehyde resin powder.
The granules were washed with warm water at 60 ° C. for 30 minutes, filtered, and the residue was washed with acetone, and dried to obtain a purified melamine-formaldehyde resin as a white powder.

D-3: Melem [manufactured by Nissan Chemical Industries, Ltd.] D-4: Nylon 6-66-610 D-5: Allantoin [Kawaken Fine Chemical Co., Ltd.]
D-6: Allantindihydroxyaluminum [manufactured by Kawaken Fine Chemical Co., Ltd., "ALDA"] D-7: CTU guanamine [manufactured by Ajinomoto Fine Techno Co., Ltd.] D-8: 12-Calcium hydroxyhydroxystearate D-9: Magnesium oxide D-10: Ionomer [Himilan 1702, manufactured by Dupont Mitsui Polychemicals Ltd.] D-11: Calcium citrate D-12: Calcium acetate D-13: Hydrotalcite [Kyowa Chemical Industry Co., Ltd.]
DHA-4] D-14: Zeolite A-4 [manufactured by Tosoh Corporation, Zeolam A-4].

[Processing Stabilizer E] E-1: Ethylenebisstearylamide E-2: Glycerin monostearate E-3: Polyethylene glycol monostearate (Nonion S-40, manufactured by Nippon Oil Co., Ltd.) -4: ethylene glycol distearate.

[Weather (Light) Stabilizer F] F-1: 2- (2'-hydroxy-3 ', 5'-di-t)
-Amylphenyl) benzotriazole F-2: 2-hydroxy-4-oxybenzylbenzophenone F-3: 2- [2'-hydroxy-3 ', 5'-bis (α, α-dimethylbenzyl) phenyl] benzotriazole F-4: bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate.

[Colorant G] G-1: carbon black (acetylene black) G-2: phthalocyanine blue pigment G-3: titanium oxide.

Synthesis Example 1 [Modified phenol resin (B-1)
Synthesis of 100 parts by weight of phenol and 10 parts by weight of melamine
54 parts by weight of a 2% by weight aqueous formaldehyde solution and 0.5 parts by weight of triethylamine were added, and the temperature was gradually raised to 100 ° C. Furthermore, after reacting at 100 ° C. for 2 hours,
The temperature was raised to 180 ° C. over 2 hours while removing water under normal pressure, and then unreacted phenol was removed under reduced pressure to obtain a modified phenol resin (softening point: 105 ° C.).

Synthesis Example 2 [Modified phenol resin (B-2)
Synthesis of 31 parts by weight of a 42% by weight aqueous solution of formaldehyde and 0.5 parts by weight of triethylamine were added to 100 parts by weight of phenol, and the temperature was raised to 80 ° C. To this was added 20 parts by weight of melamine and reacted for 1 hour. The temperature was raised to 120 ° C. while removing water under normal pressure, and the reaction was further performed for 2 hours. Next, the temperature was raised to 180 ° C. over 2 hours while removing water at normal pressure, and then unreacted phenol was removed under reduced pressure to obtain a modified phenol resin (softening point: 135 ° C.).

Synthesis Example 3 [Modified phenol resin (B-3)
Synthesis of 38 parts by weight of a 42% by weight aqueous solution of formaldehyde and 0.5 parts by weight of triethylamine were added to 100 parts by weight of phenol and reacted at 80 ° C. for 3 hours. To this, 15 parts by weight of melamine and 15 parts by weight of benzoguanamine were added to give 2 parts.
The reaction was allowed to proceed for 120 hours, the temperature was raised to 120 ° C. while removing water under normal pressure, and the reaction was further performed for 2 hours. Then, the temperature was raised to 180 ° C. over 2 hours while removing water under normal pressure, and then unreacted phenol was removed under reduced pressure to obtain a modified phenol resin (softening point: 129 ° C.).

Synthesis Example 4 [Modified phenol resin (B-4)
Synthesis of 55 parts by weight of a 42% by weight aqueous solution of formaldehyde and 0.5 parts by weight of oxalic acid were added to 100 parts by weight of phenol and 10 parts by weight of benzoguanamine, and the temperature was gradually raised to 100 ° C. Furthermore, after performing the reaction at 100 ° C. for 5 hours,
The temperature was raised to 180 ° C. over 2 hours while removing water under normal pressure, and then unreacted phenol was removed under reduced pressure to obtain a modified phenol resin (softening point: 105 ° C.).

Synthesis Example 5 [Modified phenol resin (B-5)
Synthesis of phenol phenylene aralkyl resin (JP-A-2000-
100 parts by weight of a mixture of binuclear and trinuclear bodies prepared according to Example 4 of JP-A-351822) and melamine 41
13 parts by weight of a 42% by weight aqueous solution of formaldehyde and 0.3 parts by weight of a 25% by weight aqueous ammonia solution were added to the weight parts, and the temperature was gradually raised to 100 ° C. Further, after performing a reaction at 100 ° C. for 5 hours, water was removed at normal pressure while removing water for 18 hours.
The temperature was raised to 0 ° C. over 2 hours, and then unreacted phenol was removed under reduced pressure to obtain a modified phenol resin (softening point: 93 ° C.).

Synthesis Example 6 [Synthesis of Unmodified Phenolic Resin (B'-1) Used in Comparative Example] 65 parts by weight of a 42% by weight aqueous solution of formaldehyde and 0.1 part by weight of 35% by weight concentrated hydrochloric acid were added to 100 parts by weight of phenol. Was added, and the temperature was gradually raised to 85 ° C. 85 ° C
After reacting for 1 hour at room temperature, removing water under normal pressure
The temperature was raised to 75 ° C. over 2 hours, and then unreacted phenol was removed under reduced pressure to obtain an unmodified phenol resin.

Examples 1 to 15 and Comparative Examples 1 to 5 To 100 parts by weight of polyacetal resin A, modified phenol resin B, antioxidant C, heat stabilizer D, processing stabilizer E, weather (light) stabilizer F, After mixing the coloring agent G at the ratio shown in Table 1, the mixture was melt-mixed with a twin-screw extruder to prepare a pellet-shaped composition. Using the pellets, a predetermined test piece was molded by an injection molding machine, and a mold deposit at the time of molding was evaluated. Further, the amount of formaldehyde generated from a predetermined test piece was measured. Table 1 shows the results.

For comparison, an example in which the modified phenol resin was not added and an example in which the unmodified phenol resin was added instead of the modified phenol resin were evaluated in the same manner as described above. Table 2 shows the results.

[0122]

[Table 1]

[0123]

[Table 2]

As is clear from the table, compared with the comparative example,
The resin compositions of the examples have less mold deposit during molding and have improved moldability. Also, the amount of formaldehyde generated has been greatly reduced.

 ──────────────────────────────────────────────────続 き Continuing on the front page F term (reference) 4F071 AA40 AA41 AE05 AE09 AF45 AH07 AH08 AH12 BA01 BB05 BC07 4J002 CB001 CC282 DA036 DE076 DE086 DE226 DE236 DE286 DH046 DJ006 DK006 EE036 EE056 EG026 EG036 EJ046 EP016 EQ026 ER026 ET006 ET016 EU076 EU176 EU186 EV066 EV076 EW066 FD036 FD066 FD076 FD096 GB00 GC00 GL00 GN00 GQ00

Claims (14)

[Claims] 1. A polyacetal resin composition comprising a polyacetal resin (A) and a condensate (B) of a phenol, a basic nitrogen-containing compound and an aldehyde. 2. The composition according to claim 1, wherein in the component (B), the basic nitrogen-containing compound is a cyclic basic nitrogen-containing compound. 3. The composition according to claim 1, wherein in the component (B), the basic nitrogen-containing compound is a triazine. 4. The composition according to claim 1, wherein the component (B) is obtained by reacting in the presence of at least one selected from a basic catalyst and an acidic catalyst. 5. The composition according to claim 1, wherein the component (B) is obtained by reacting in the presence of a basic catalyst. 6. The composition according to claim 1, wherein the component (B) is obtained by reacting under weakly basic conditions. 7. The composition according to claim 1, wherein the component (B) is a novolak-type condensate. 8. The ratio of the component (B) is 0.0%, based on 100 parts by weight of the component (A), in terms of a basic nitrogen-containing compound.
The composition according to claim 1, wherein the amount is from 01 to 100 parts by weight. 9. The composition according to claim 1, further comprising at least one selected from an antioxidant, a heat stabilizer, a processing stabilizer, a weather (light) stabilizer and a coloring agent. 10. A resin composition comprising a polyacetal resin (A) and a novolak condensate (B) of phenol, aminotriazines and formaldehyde, wherein the proportion of the component (B) is as follows: 0.01 to 100 parts by weight of component (A) in terms of a basic nitrogen-containing compound.
50 parts by weight of a polyacetal resin composition. 11. A method for producing a polyacetal resin composition by mixing a polyacetal resin (A) and a condensate (B) of a phenol, a basic nitrogen-containing compound and an aldehyde. 12. A molded article formed from the composition according to claim 1. 13. (1) When stored in a closed space at a temperature of 80 ° C. for 24 hours, the amount of formaldehyde generated is ² μg or less per 1 cm ² of surface area of the molded article, and / or (2) a temperature of 60
13. The molded article according to claim 12, wherein the amount of formaldehyde generated is 3 μg or less per 1 cm ² of surface area of the molded article when stored for 3 hours in a closed space at a temperature of 50 ° C. and a saturated humidity. 14. The molded article according to claim 12, wherein the molded article is at least one selected from an automobile part, an electric / electronic part, a building material / piping part, a living / cosmetic part, and a medical part.