JP2015209501A - Polyacetal resin composition and molded product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polyacetal resin composition that has excellent mechanical properties, particularly rigidity, toughness, and impact resistance in a good balance, and is also extremely excellent in thermochromic properties and the appearance of a molded product, and provide a molded product.SOLUTION: This invention relates to a polyacetal resin composition that comprises polyacetal resin (A), and crystalline calcium silicate hydrate (B) of more than 1.0 pts. mass and 25.0 pts. mass or less relative to the polyacetal resin (A) 100 pts. mass, and a molded product.

Description

  The present invention relates to a polyacetal resin composition and a molded article.

  The polyacetal resin is a crystalline resin and is a resin material having excellent rigidity, strength, toughness, slidability, and creep properties. The use of the polyacetal resin covers a wide range such as materials for mechanical parts such as automobile parts, electric or electronic parts, and industrial parts.

  In particular, parts such as gears and cams for water purifiers, water meters, and the like are examples of characteristic uses of polyacetal resin. However, as the use expands and diversifies, the demand for quality has become higher. Especially in the parts around water, there are many opportunities to touch not only cold water but also hot water and hot water. Long-term strength retention is required. Conventional polyacetal resins do not have physical properties that satisfy such requirements, and their use is currently limited.

  Conventionally, as a technique for improving mechanical properties such as rigidity and strength of polyacetal resin, a technique of blending an inorganic filler such as glass fiber or carbon fiber has been used. Although this method is effective in improving rigidity, strength, heat resistance, etc., the toughness, impact resistance, etc. are significantly impaired, and the appearance of the molded product tends to deteriorate. I couldn't.

  As a technique for suppressing deterioration in toughness and impact resistance and improving the appearance of molded products, polyacetal resin, inorganic fillers having a small particle diameter, such as wollastonite (Patent Document 1), calcium carbonate (Patent Document) 2) and the like are known.

JP 49-21451 Japanese Patent Laid-Open No. 1-170641

  However, in the polyacetal resin composition described in Patent Document 1, the rigidity is increased, but the improvement in toughness and appearance of the molded product is insufficient. In the polyacetal resin composition described in Patent Document 2, rigidity and toughness are not achieved. Although the appearance of the molded product can be improved in a well-balanced manner, the thermal discoloration is large. As described above, the conventional polyacetal resin compositions described in Patent Documents 1 and 2 and the like further improve mechanical properties such as rigidity, toughness and impact resistance, thermal discoloration, and appearance of molded products. There is a need for improvement.

  Accordingly, an object of the present invention is to provide a polyacetal resin composition and a molded product that have an excellent balance of mechanical properties, particularly rigidity, toughness, and impact resistance, and are extremely excellent in thermal discoloration and appearance of molded products. To do.

As a result of intensive studies to solve the above problems, the present inventors have found that a polyacetal resin composition containing a polyacetal resin and crystalline calcium silicate hydrate improves the inherent rigidity of the polyacetal resin, while improving toughness. by minimizing a decrease in impact resistance, to achieve good mechanical properties balance, further suppressing the discoloration at high temperatures molding, found to give the appearance of excellent molded article, the present invention It came to complete.

That is, the present invention relates to the following.
[1] A polyacetal resin containing a polyacetal resin (A) and a crystalline calcium silicate hydrate (B) in an amount of more than 1.0 to 25.0 parts by mass with respect to 100 parts by mass of the polyacetal resin (A). Composition.
[2] The polyacetal resin composition according to [1], wherein the crystalline calcium silicate hydrate (B) has a layered structure and / or a card house structure.
[3] The polyacetal resin composition according to [1] or [2], wherein the crystalline calcium silicate hydrate (B) is tobermorite.
[4] A molded article comprising the polyacetal resin composition according to any one of [1] to [3].

  The polyacetal resin composition and molded product of the present invention have an effect that the mechanical properties are well-balanced, and further, the discoloration in high temperature molding is suppressed and the appearance of the molded product is excellent.

  Hereinafter, a mode for carrying out the present invention (hereinafter referred to as “the present embodiment”) will be described in detail. The following embodiment is an exemplification for explaining the present invention, and is not intended to limit the present invention only to this embodiment. And this invention can be deform | transformed suitably and implemented within the range of the summary.

(Polyacetal resin composition)
The polyacetal resin composition of the present embodiment comprises a polyacetal resin (A) and a crystalline calcium silicate hydrate of more than 1.0 part by weight and less than 25.0 parts by weight with respect to 100 parts by weight of the polyacetal resin (A) ( B).

-Polyacetal resin (A)-
The polyacetal resin (A) used in the present embodiment may be a known polyacetal resin, and is not particularly limited.

Although it does not specifically limit as polyacetal resin (A) used by this embodiment, Specifically, a polyacetal homopolymer and a polyacetal copolymer are mentioned, for example.
Although it does not specifically limit as a polyacetal homopolymer, For example, the polyacetal homopolymer obtained by homopolymerizing a formaldehyde monomer or the cyclic oligomer of formaldehyde is mentioned as a representative example. Further, as a polyacetal homopolymer, for example, a block component obtained by polymerizing a formaldehyde monomer or a cyclic oligomer of formaldehyde in the presence of a compound having a functional group such as a hydroxyl group at both ends or one end, for example, polyalkylene glycol. The polyacetal homopolymer which has can also be used. Here, the cyclic oligomer of formaldehyde is not particularly limited, and examples thereof include formaldehyde trimer (trioxane) and tetramer (tetraoxane).

  Although it does not specifically limit as a polyacetal copolymer, For example, the polyacetal copolymer obtained by copolymerizing a formaldehyde monomer or the cyclic oligomer of formaldehyde, and cyclic ether and / or cyclic formal is mentioned as a representative example. Further, as the polyacetal copolymer, for example, a compound having a functional group such as a hydroxyl group at both ends or one end, for example, a hydrogenated polybutadiene glycol, a formaldehyde monomer or a cyclic oligomer of formaldehyde, a cyclic ether and / or a cyclic A polyacetal copolymer having a block component obtained by copolymerizing with formal can also be used. Furthermore, as the polyacetal copolymer, for example, a polyacetal copolymer having a branch obtained by copolymerizing a monofunctional glycidyl ether or a polyacetal copolymer having a crosslinked structure obtained by copolymerizing a polyfunctional glycidyl ether can be used. Here, the cyclic ether and the cyclic formal are not particularly limited, but examples thereof include ethylene oxide, propylene oxide, epichlorohydrin, glycols such as 1,3-dioxolane and 1,4-butanediol formal, and cyclic formals of diglycol. Can be mentioned.

  In this embodiment, any of a polyacetal homopolymer and a polyacetal copolymer may be used as the polyacetal resin (A), and is not particularly limited. These polyacetal resins (A) may be used alone or in combination of two or more.

-Crystalline calcium silicate hydrate (B)-
The crystalline calcium silicate hydrate (B) used in the present embodiment is not particularly limited, and examples thereof include a wollastonite system, a tobermorite system, a gyrolite system, and the wollastonite system. , Zonolite, catite, okenite, foshygite, hillbrandite, and the tobermorite system includes tobermorite (9Å, 11Å, 14Å, etc.), C · S · H (I), C · S · H (II The gyrolite system includes gyrolite, trusscot stone, and Z-phase. The crystalline calcium silicate hydrate (B) used in the present embodiment is preferably zonolite or tobermorite from the viewpoint of industrial availability, and more preferably tobermorite from the viewpoint of availability. .

  These crystalline calcium silicate hydrates (B) may be used alone or in combination of two or more.

  The structure of the crystalline calcium silicate hydrate (B) is not particularly limited, and examples thereof include a layered structure, a card house structure, a fiber structure, a strip structure, a fiber bundle structure, and a foil structure. A layered structure and / or a card house structure is preferable. The structure provided in the crystalline calcium silicate hydrate (B) may be a combination of the above structures.

The average particle diameter of the crystalline calcium silicate hydrate (B) is preferably 0.01 μm or more, more preferably 0.05 μm or more, from the viewpoints of rigidity improvement and toughness balance and appearance. More preferably, it is 0.1 μm or more, and from the viewpoint of imparting sufficient dispersibility, it is preferably 100.0 μm or less, more preferably 80 μm, and even more preferably 50 μm or less. In addition, the average particle diameter of crystalline calcium silicate hydrate (B) is the center particle diameter D50 of the particle size distribution obtained by measuring by a laser beam diffraction measurement method.
The method for controlling the average particle size of the crystalline calcium silicate hydrate (B) within the above range is not particularly limited. For example, the axial flow mill method, the annular mill method, the roll mill method, the ball mill method, Examples thereof include a jet mill method, a container rotary compression shear type mill method, and a method of pulverizing with a porcelain mortar.

The tobermorite used in the present embodiment is not particularly limited. For example, it is represented by a referential formula of 5CaO · 6SiO ₂ · 0 to 4H ₂ O.

  The method for preparing tobermorite is not particularly limited, and for example, a well-known method such as a hydrothermal synthesis technique in which a siliceous raw material and a calcareous raw material are dispersed in water and then cured under high temperature and high pressure conditions may be used. .

  The polyacetal resin composition of the present embodiment contains a specific amount (as described above) of crystalline calcium silicate hydrate (B) in the polyacetal resin (A), thereby effectively improving rigidity and improving toughness. It is possible to suppress deterioration and maintain balanced rigidity and toughness. More specifically, it achieves well-balanced mechanical properties, and further suppresses discoloration during high-temperature molding, resulting in excellent molded products. It becomes possible to give the appearance of.

  In the polyacetal resin composition of the present embodiment, the blending ratio of the crystalline calcium silicate hydrate (B) is 1.0 part by mass with respect to 100 parts by mass of the polyacetal resin (A) from the viewpoint of enhancing mechanical properties. From the viewpoint of facilitating the molding of the composition, it may be 25 parts by mass or less with respect to 100 parts by mass of the polyacetal resin (A), and 10 parts by mass or more. Preferably there is.

-Others-
In the polyacetal resin composition of this embodiment, together with the polyacetal resin (A) and crystalline calcium silicate hydrate (B), other inorganic fillers, organic fillers, and inorganic fillers treated with an organic agent An agent powder may be used. In addition, the polyacetal resin composition of the present embodiment is further imparted with other characteristics, so that other additives such as antioxidants, formic acid scavengers, weather resistance (light ) Stabilizers such as stabilizers and heat stabilizers, antistatic agents, mold release (lubricating) agents and the like may be added. Furthermore, in the polyacetal resin composition of the present embodiment, a suitable known additive, for example, a polyolefin resin, a sliding agent, a pigment, or the like is blended as necessary within a range not impairing the object of the present invention. Can do.

-Other inorganic fillers-
Specific examples of other inorganic fillers are not particularly limited, and examples thereof include metal fibers such as talc, glass fiber, carbon fiber, boron nitride, hydrotalcite, aluminum, titanium, copper, and brass.

--Organic filler--
Specific examples of the organic filler are not particularly limited, and examples thereof include cellulose, polyurethane resin, aromatic polyamide resin, and fluorine resin.

--Inorganic filler powder treated with organic agent--
The inorganic filler powder treated with the organic agent is not particularly limited, and examples thereof include silane-based, titanate-based, aluminum-based, and zirconium-based powders.

--Antioxidant--
As the antioxidant, a hindered phenol antioxidant is preferable. Specifically, although not particularly limited, 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-tert-butyl-5-methyl-4-hydroxyphenyl) -propionate], pentaerythritol te Lakis [methylene-3- (3 ′, 5′-di-t-butyl-4′-hydroxyphenyl) propionate] methane and the like, and triethylene glycol-bis- [3- (3-t-butyl-5 -Methyl-4-hydroxyphenyl) -propionate] and pentaerythritol tetrakis [methylene-3- (3 ′, 5′-di-t-butyl-4′-hydroxyphenyl) propionate] methane are preferred.

  These antioxidants may be used alone or in combination of two or more.

--Formic acid scavenger--
The formic acid scavenger used in the present embodiment is not particularly limited, and examples thereof include amino-substituted triazine compounds, condensates of amino-substituted triazine compounds and formaldehyde (for example, condensates of melamine and formaldehyde).

Specific examples of the amino-substituted triazine compound are not particularly limited. For example, 2,4-diamino-sym-triazine, 2,4,6-triamino-sym-triazine, N-butylmelamine, N-phenylmelamine, N , N-diphenylmelamine, N, N-diallylmelamine, benzoguanamine (2,4-diamino-6-phenyl-sym-triazine), acetoguanamine (2,4-diamino-6-methyl-sym-triazine), 2, 4-diamino-6-butyl-sym-triazine and the like can be mentioned.
Specific examples of the adduct of an amino-substituted triazine compound and formaldehyde are not particularly limited, and examples thereof include N-methylol melamine, N, N′-dimethylol melamine, N, N ′, N ″ -trimethylol melamine. Etc.

  The formic acid scavenger is not particularly limited, and examples thereof include alkali metal or alkaline earth metal hydroxides, inorganic acid salts, carboxylate salts, and alkoxides. Specific examples of these include, but are not limited to, for example, metal hydroxides such as sodium, potassium, magnesium, calcium or barium, carbonates of the metals, phosphates of the metals, and silicates of the metals. , Borate of the metal, carboxylate of the metal, layered double hydroxide of the metal, and the like. In particular, the metal carboxylate is preferable from the viewpoint of thermal stability and mold deposit property. .

Although it does not specifically limit as said layered double hydroxide of a metal, For example, the hydrotalcite represented by following General formula (1) is mentioned.
[(M ²⁺ ) _1-X (M ³⁺ ) _X (OH) ₂ ] _X ⁺ [(A ⁿ⁻ ) _{x / n} · mH ₂ O] _X ⁻
... (1)
Wherein, M ²⁺ is a divalent metal, M ³⁺ represents an anion of trivalent metal, A ^n-n-valent (n is an integer of 1 or more), X is 0 <X ≦ 0.33, m represents a positive number. ]
In the general formula (1), examples of M ²⁺ are not particularly limited. For example, Mg ²⁺ , Mn ²⁺ , Fe ²⁺ , Co ²⁺ , Ni ²⁺ , Cu ²⁺ , Zn ²⁺ etc., and examples of M ^3+, but are not limited to, for ^{example, Al 3+, Fe 3+, Cr} 3+, Co 3+, in 3+ , and the like, as examples of a ^n- Is not particularly limited, for example, OH ⁻ , F ⁻ , Cl ⁻ , Br ⁻ , NO ₃ ⁻ , CO ₃ ²⁻ , SO ₄ ²⁻ , Fe (CN) ₆ ³⁻ , CH ₃ COO ⁻ , oxalic acid Ion, salicylate ion, and the like, and CO ₃ ²⁻ and OH ^{2 −} are particularly preferable.
Specific examples of the hydrotalcites represented by the general formula (1) are not particularly limited. For example, natural hydrotalcites represented by Mg _0.75 Al _0.25 (OH) ₂ (CO ₃ ) _0.125 · 0.5H ₂ O Examples thereof include synthetic hydrotalcite represented by hydrotalcite, Mg _4.5 Al ₂ (OH) ₁₃ CO ₃ .3.5H ₂ O, Mg _4.3 Al ₂ (OH) _12.6 CO _{3, and the} like.

  The carboxylic acid constituting the metal carboxylate is preferably a saturated or unsaturated aliphatic carboxylic acid having 10 to 36 carbon atoms, and these carboxylic acids may be substituted with a hydroxyl group. Specific examples of the saturated or unsaturated aliphatic carboxylate are not particularly limited. For example, calcium dimyristate, calcium dipalmitate, calcium distearate, (myristic acid-palmitic acid) calcium, (myristic acid-stearic acid) Acid) calcium, (palmitic acid-stearic acid) calcium, and calcium di-12-hydroxystearate, and calcium dipalmitate, calcium distearate, and calcium di-12-hydroxystearate are preferable.

  In this embodiment, these formic acid scavengers may be used alone or in combination of two or more.

--- Weather resistance (light) stabilizer ---
The weathering (light) stabilizer used in the present embodiment is preferably at least one selected from the group consisting of benzotriazole-based and oxalic acid anilide-based ultraviolet absorbers and hindered amine-based light stabilizers.

Although it does not specifically limit as an example of a benzotriazole type ultraviolet absorber, For example, 2- (2'-hydroxy-5'-methyl-phenyl) benzotriazole, 2- (2'-hydroxy-3 ', 5'-) Di-t-butyl-phenyl) benzotriazole, 2- [2′-hydroxy-3 ′, 5′-bis (α, α-dimethylbenzyl) phenyl] -2H-benzotriazole, 2- [2′-hydroxy- 3 ′, 5′-bis- (α, α-dimethylbenzyl) phenyl] -2H-benzotriazole, 2- (2′-hydroxy-4′-octoxyphenyl) benzotriazole and the like. These benzotriazole-based ultraviolet absorbers may be used alone or in combination of two or more.
Although it does not specifically limit as an example of an oxalic acid alinide type ultraviolet absorber, For example, 2-ethoxy-2'-ethyl oxalic acid bisanilide, 2-ethoxy-5-t-butyl-2'-ethyl oxalic Acid bisanilide, 2-ethoxy-3'-dodecyl oxalic acid bisanilide, etc. are mentioned. Preferably 2- [2′-hydroxy-3 ′, 5′-bis- (α, α-dimethylbenzyl) phenyl] -2H-benzotriazole, 2- (2′-hydroxy-3 ′, 5′-di- t-butyl-phenyl) benzotriazole. These oxalic acid alinide ultraviolet absorbers may be used alone or in combination of two or more.

  Examples of the hindered amine light stabilizer are not particularly limited, and examples thereof include N, N ′, N ″, N ′ ″-tetrakis- (4,6-bis- (butyl- (N-methyl 2,2 , 6,6-tetramethylpiperidin-4-yl) amino) -triazin-2-yl) -4,7-diazadecane-1,10-diamine, dibutylamine, 1,3,5-triazine, N, N ′ A polycondensate of bis (2,2,6,6-tetramethyl-4-piperidyl-1,6-hexamethylenediamine and N- (2,2,6,6-tetramethyl-4-piperidyl) butylamine; Poly [{6- (1,1,3,3-tetramethylbutyl) amino-1,3,5-triazine-2,4-diyl} {(2,2,6,6-tetramethyl-4-piperidyl ) Imino} hexamethylene {(2,2,6,6-teto Lamethyl-4-piperidyl) imino}], a condensate of dimethyl succinate and 4-hydroxy-2,2,6,6-tetramethyl-1-piperidineethanol, bis (2,2,6,6) decanoate -Reaction product of tetramethyl-1 (octyloxy) -4-piperidinyl) ester, 1,1-dimethylethyl hydroperoxide and octane, bis (1,2,2,6,6-pentamethyl-4-piperidyl) [[3,5-bis (1,1-dimethylethyl) -4-hydroxyphenyl] methyl] butyl malonate, methyl, 1,2,2,6,6-pentamethyl-4-piperidyl sebacate, bis (2 , 2,6,6-tetramethyl-4-piperidyl) -sebacate, 1,2,3,4-butanetetracarboxylic acid and 1,2,2,6,6-pentamethyl-4-pipe And a condensate of dinol and β, β, β ′, β′-tetramethyl-3,9- [2,4,8,10-tetraoxaspiro (5,5) undecane] diethanol, and the like. 2,2,6,6-tetramethyl-4-piperidyl) -sebacate, bis- (N-methyl-2,2,6,6-tetramethyl-4-piperidinyl) sebacate, 1,2,3,4 Butanetetracarboxylic acid, 1,2,2,6,6-pentamethyl-4-piperidinol and β, β, β ′, β′-tetramethyl-3,9- [2,4,8,10-tetraoxaspiro (5,5) undecane] A condensate with diethanol is preferred, and these hindered amine light stabilizers may be used alone or in combination of two or more.

-Antistatic agent-
Although it does not specifically limit as an antistatic agent, For example, electroconductive carbon black, a metal powder, or a fiber is mentioned.

--- Release (lubricant) ---
Although it does not specifically limit as a mold release (lubricant), For example, alcohol, fatty acid and those esters, polyoxyalkylene glycol, an olefin compound whose average degree of polymerization is 10-500, silicone etc. are mentioned, especially carbon. Ethylene glycol dipalmitate derived from a fatty acid of several 12 to 22 and ethylene glycol diheptadecylate are preferable.

［式中、Ｒ¹は水素原子又はメチル基を表し、Ｒ²は水素原子、炭素数１〜１０のアルキル基、カルボキシル基、２〜５個の炭素原子を含むアルキル化カルボキシ基、２〜５個の炭素原子を有するアシルオキシ基、又はビニル基を表す。］ --- Polyolefin resin--
Although it does not specifically limit as polyolefin resin, For example, the homopolymer or copolymer of the olefin type unsaturated compound shown by following General formula (2), or its modified body is mentioned.

[Wherein, R ¹ represents a hydrogen atom or a methyl group, R ² represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, a carboxyl group, an alkylated carboxy group containing 2 to 5 carbon atoms, 2 to 5 An acyloxy group having one carbon atom or a vinyl group is represented. ]

Specific examples of the homopolymer or copolymer of the olefinically unsaturated compound represented by the general formula (2) are not particularly limited. For example, polyethylene (high density polyethylene, medium density polyethylene, high pressure method low density polyethylene, linear chain) Low density polyethylene, ultra low density polyethylene), polypropylene, polybutene, polybutadiene, ethylene-propylene copolymer, ethylene-butene copolymer, polypropylene-butene copolymer, ethylene-acrylic acid ester copolymer, ethylene-methacrylic acid ester copolymer, ethylene-acrylic Examples include acid copolymers and ethylene-vinyl acetate copolymers. The modified products of these polymers and copolymers are not particularly limited, and examples thereof include hydrogenated polybutadiene, and graft copolymers obtained by grafting one or more other vinyl compounds to the above polymers and copolymers.
As the polyolefin resin, polyethylene (high pressure method low density polyethylene, linear low density polyethylene, ultra low density polyethylene), ethylene-propylene copolymer, and ethylene-butene copolymer are particularly preferable.

  The weight average molecular weight (Mw) of these polyolefin resins is not particularly limited, but is preferably 10,000 or more, more preferably 15,000, from the viewpoint of improving the friction and wear performance between the self-materials. Further, from the viewpoint of improving the friction and wear performance with the polyacetal resin (A), it is preferably 300,000 or less, more preferably 100,000 or less, and particularly preferably 80,000 or less.

The blending ratio of the polyolefin resin is preferably 0.1 parts by mass or more with respect to 100 parts by mass of the polyacetal resin (A) from the viewpoint of obtaining a sufficient slidability improving effect, and 0.2 parts by mass or more. More preferably, it is preferably 10 parts by mass or less, more preferably 5 parts by mass or less, based on 100 parts by mass of the polyacetal resin (A) from the viewpoint of preventing peeling in the molded product.
In particular, when the blending ratio of the polyolefin resin is 0.1 to 10 parts by mass with respect to 100 parts by mass of the polyacetal resin (A), it is possible to obtain a good balance of slidability, impact property, and rigidity. Good molding processing is possible.

--- Sliding agent--
Although it does not specifically limit as a sliding agent, For example, ester of alcohol and a fatty acid, ester of alcohol and dicarboxylic acid, a polyoxyalkylene glycol compound, etc. are mentioned.

Although it does not specifically limit as ester of alcohol and a fatty acid, For example, ester of the alcohol shown below and a fatty acid is mentioned. Here, alcohol is monohydric alcohol and polyhydric alcohol.
Although it does not specifically limit as monohydric alcohol, For example, methyl alcohol, ethyl alcohol, propyl alcohol, butyl alcohol, amyl alcohol, hexyl alcohol, heptyl alcohol, octyl alcohol, nonyl alcohol, decyl alcohol, undecyl alcohol, lauryl alcohol, Tridecyl alcohol, myristyl alcohol, pentadecyl alcohol, cetyl alcohol, heptadecyl alcohol, stearyl alcohol, oleyl alcohol, nonadecyl alcohol, eicosyl alcohol, ceryl alcohol, behenyl alcohol, melyl alcohol, hexyldecyl alcohol, octyldodecyl alcohol, decyl Saturated or unsaturated alcohols such as myristyl alcohol and decylstearyl alcohol Lumpur, and the like.
The polyhydric alcohol is not particularly limited. For example, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, butanediol, pentanediol, hexanediol, glycerin, diglycerin, triglycerin, pentaerythritol, and arabitol. , Ribitol, xylitol, sorbite, sorbitan, sorbitol, mannitol and the like.
The fatty acid is not particularly limited, for example, caproic acid, enanthic acid, caprylic acid, pelargonic acid, capric acid, undecyl acid, lauric acid, tridecyl acid, myristic acid, pentadecylic acid, palmitic acid, pentadecylic acid, stearic acid, Nanodecanoic acid, arachidic acid, behenic acid, lignoceric acid, serotic acid, heptaconic acid, montanic acid, mellicic acid, lacteric acid, undecylenic acid, oleic acid, elaidic acid, celetic acid, erucic acid, brassic acid, sorbic acid, linoleic acid , Linolenic acid, arachidonic acid, propiolic acid, stearic acid. The fatty acid used in the present embodiment may include a mixture of the fatty acids, a natural product containing the fatty acid as a component, and the fatty acid substituted with a hydroxy group.

  In particular, the ester of alcohol and fatty acid is preferably an ester of a fatty acid having 10 or more carbon atoms and an alcohol having 10 or more carbon atoms from the viewpoint of improving frictional wear performance, and a fatty acid having 12 or more carbon atoms and 10 or more carbon atoms. An ester with an alcohol is more preferable, and an ester with a fatty acid having 12 to 30 carbon atoms and an alcohol having 10 to 20 carbon atoms is still more preferable.

The ester of alcohol and dicarboxylic acid is not particularly limited. For example, octyl alcohol, nonyl alcohol, decyl alcohol, undecyl alcohol, lauryl alcohol, tridecyl alcohol, myristyl alcohol, pentadecyl alcohol, cetyl alcohol, heptadecyl alcohol Saturated or unsaturated primary alcohols such as stearyl alcohol, oleyl alcohol, nonadecyl alcohol, eicosyl alcohol, seryl alcohol, behenyl alcohol, melyl alcohol, hexyl decyl alcohol, octyl dodecyl alcohol, decyl myristyl alcohol, decyl stearyl alcohol; Oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, Shin acid, maleic acid, of a dicarboxylic acid such as fumaric acid, monoesters and diesters, and mixtures thereof, and the like.
In particular, the ester of alcohol and dicarboxylic acid is preferably an ester of alcohol having 10 or more carbon atoms and dicarboxylic acid.

Although it does not specifically limit as a polyoxyalkylene glycol compound, For example, the following 1st-3rd group compounds are mentioned.
Although it does not specifically limit as a compound of the 1st group, For example, the polycondensate which uses alkylene glycol as a monomer is mentioned, Specifically, Although it does not specifically limit, For example, polyethylene glycol, polypropylene glycol, ethylene glycol and Examples thereof include a propylene glycol block polymer. The degree of polymerization of these compounds is preferably 5 to 1,000, and more preferably 10 to 500.
The second group of compounds is an etherified product of the first group of compounds and an aliphatic alcohol. Specifically, the compound is not particularly limited. For example, polyethylene glycol oleyl ether (degree of ethylene oxide polymerization: 5 to 50) , Polyethylene glycol cetyl ether (ethylene oxide polymerization degree 5-50), polyethylene glycol stearyl ether (ethylene oxide polymerization degree 5-30), polyethylene glycol lauryl ether (ethylene oxide polymerization degree 5-30), polyethylene glycol tridecyl ether (ethylene Oxide polymerization degree 5-30), polyethylene glycol nonyl phenyl ether (ethylene oxide polymerization degree 2-100), polyethylene glycol octyl phenyl ether (ethylene oxide polymerization) 4 to 50), and the like.
The third group of compounds is an ester of the first group of compounds and a higher fatty acid, and specifically, although not particularly limited, for example, polyethylene glycol monolaurate (ethylene oxide polymerization degree 2 to 30), Examples include polyethylene glycol monostearate (ethylene oxide polymerization degree 2-50), polyethylene glycol monooleate (ethylene oxide polymerization degree 2-50), and the like.

--Pigment--
Although it does not specifically limit as a pigment, For example, an inorganic pigment, an organic pigment, a metallic pigment, a fluorescent pigment etc. are mentioned. Examples of the inorganic pigment include those generally used for resin coloring. The inorganic pigment is not particularly limited. For example, zinc sulfide, titanium oxide, barium sulfate, titanium yellow, cobalt blue, fuel pigment, carbonate, phosphate, acetate, carbon black, acetylene black, lamp black Etc. Examples of organic pigments include, but are not limited to, condensed azo, inone, furothocyanin, monoazo, diazo, polyazo, anthraquinone, heterocyclic, pennon, quinacridone, thioindico, and berylene. And pigments such as pigments, dioxazines, and phthalocyanines.

  In the polyacetal resin composition of the present embodiment, the blending ratio of the pigment may be determined according to the color tone of the resin composition, for example, 0.05 to 5 parts by mass with respect to 100 parts by mass of the polyacetal resin (A). .

  The polyacetal resin composition of this embodiment can improve long-term heat aging property by mix | blending a suitable additive according to a use. Below, the polyacetal resin composition especially suitable in the polyacetal resin composition of this embodiment is described.

  As a preferred specific example, together with the components (A) and (B) described above, 0.01 to 5 parts by mass of an antioxidant and / or formic acid scavenger is added to 100 parts by mass of the polyacetal resin (A). And polyacetal resin compositions. According to this composition, a polyacetal resin composition with improved long-term heat aging resistance can be obtained.

  As another suitable specific example, 0.01-10 mass parts antioxidant and formaldehyde reactive nitrogen are included with respect to 100 mass parts of polyacetal resin (A) with the component of said (A) and (B). Examples thereof include a polyacetal resin composition containing at least one selected from the group consisting of a polymer or compound, a formic acid scavenger, a weather resistance (light) stabilizer, and a release (lubricant) agent. According to this composition, a polyacetal resin composition having further improved long-term heat aging resistance can be obtained.

Details of the polymer or compound containing formaldehyde-reactive nitrogen will be described below.
The polymer or compound containing formaldehyde-reactive nitrogen is not particularly limited, and examples thereof include polyamide resins such as nylon 4,6, nylon 6, nylon 6,6, nylon 6,10, nylon 6,12, nylon 12, and the like, and These polymers (for example, nylon 6/6, 6/6, 10, nylon 6/6, 12, etc.) can be mentioned.

  Examples of the polymer or compound containing formaldehyde-reactive nitrogen include acrylamide and its derivatives, and copolymers of acrylamide and its derivatives and other vinyl monomers. For example, acrylamide and its derivatives and other vinyl monomers are converted into metal alcoholates. And a poly-β-alanine copolymer obtained by polymerization in the presence of

Further, the polymer or compound containing formaldehyde-reactive nitrogen includes amide compounds, amino-substituted triazine compounds, adducts of amino-substituted triazine compounds and formaldehyde, condensates of amino-substituted triazine compounds and formaldehyde, urea derivatives, hydrazine derivatives, Examples include imide compounds, imidazole compounds, and urea.
Here, specific examples of the amide compound are not particularly limited, and examples thereof include polyvalent carboxylic acid amides such as isophthalic acid diamide and anthranilamides.
Specific examples of the amino-substituted triazine compound are not particularly limited. For example, 2,4-diamino-sym-triazine, 2,4,6-triamino-sym-triazine, N-butylmelamine, N-phenylmelamine, N , N-diphenylmelamine, N, N-diallylmelamine, benzoguanamine (2,4-diamino-6-phenyl-sym-triazine), acetoguanamine (2,4-diamino-6-methyl-sym-triazine), 2, 4-diamino-6-butyl-sym-triazine and the like can be mentioned.
Specific examples of the adduct of an amino-substituted triazine compound and formaldehyde are not particularly limited, and examples thereof include N-methylol melamine, N, N′-dimethylol melamine, N, N ′, N ″ -trimethylol melamine. Etc.
Although the specific example of the condensate of an amino substituted triazine compound and formaldehyde is not specifically limited, For example, the condensate of melamine and formaldehyde etc. are mentioned.
Although it does not specifically limit as a specific example of a urea derivative, For example, N-substituted urea, a urea condensate, ethylene urea, a hydantoin compound, a ureido compound etc. are mentioned, Here, as a specific example of N-substituted urea, Although not particularly limited, for example, methylurea substituted with a substituent such as an alkyl group, alkylenebisurea, aryl substituted urea, and the like can be mentioned, and specific examples of the urea condensate are not particularly limited. For example, urea and formaldehyde Specific examples of hydantoin compounds include, but are not particularly limited to, for example, hydantoin, 5,5-dimethylhydantoin, 5,5-diphenylhydantoin, and the like, and specific examples of ureido compounds Is not particularly limited, and examples thereof include allantoin.
Although it does not specifically limit as a hydrazine derivative, For example, a hydrazide compound is mentioned, Here, Although it does not specifically limit as a specific example of a hydrazide compound, For example, dicarboxylic acid dihydrazide can be mentioned, More specifically, , Malonic acid dihydrazide, succinic acid dihydrazide, glutaric acid dihydrazide, adipic acid dihydrazide, pimelic acid dihydrazide, speric acid dihydrazide, azelaic acid dihydrazide, sebacic acid dihydrazide, dodecanedioic acid dihydrazide, isophthalic acid dihydrazide, phthalic acid dihydrazide And naphthalene carbodihydrazide.
Specific examples of the imide compound are not particularly limited, and examples thereof include succinimide, glutarimide, and phthalimide.
These polymers or compounds containing formaldehyde-reactive nitrogen atoms may be used alone or in combination of two or more.

(Production method of polyacetal resin composition)
The polyacetal resin composition of the present embodiment is not particularly limited. For example, the polyacetal resin composition can be produced by mixing the components (A) and (B) described above and other components and kneading them using a kneader. it can.
Examples of the kneading machine include an extruder, a heating roll, a kneader, a Banbury mixer, and the like. In particular, from the viewpoint of productivity, an extruder is preferable, and from the viewpoint of stable mass productivity, a uniaxial or biaxial An extruder is more preferred.
The kneading temperature may be determined according to a preferable processing temperature of the base polyacetal resin, for example, 140 to 260 ° C, and preferably 180 to 230 ° C.
The order in which each component is added to the kneader is not particularly limited. For example, one component or a plurality of components may be added to the kneader, or a mixture composed of a plurality of components may be prepared in advance.

(Molding)
The molded product of the present embodiment includes the polyacetal resin composition of the present embodiment described above.
As described above, the polyacetal resin composition of the present embodiment has a balance of mechanical properties, further suppresses discoloration during high-temperature molding, and has an effect of excellent appearance of the molded product. Excellent deposit and creep resistance. Thus, since the polyacetal resin composition of this embodiment has the outstanding heat-aging property, the molded product of this embodiment can be used as a molded product of various uses.

  Specific examples of the molded product of this embodiment include, for example, mechanical parts such as gears, cams, sliders, levers, shafts, bearings, guides, etc .; resin parts for outsert molding, resin parts for insert molding, chassis, trays, side plates , Printers, photocopiers and other cameras (cameras, digital cameras, digital video cameras, etc.) or video equipment parts; music, video, information equipment; communication equipment parts; electrical equipment parts; electronic equipment parts; Fuel pump modules, valves, fuel parts such as gasoline tank flanges, door parts, seat belt peripheral parts, combination switch parts, automotive parts such as switches; housing equipment, etc., industrial parts, etc. In particular, from the viewpoint of sufficiently obtaining the effect of the polyacetal resin composition of the present invention, a gear, a cam, a slider, a lever , Shaft, bearings, it is preferable that the mechanical parts of the guide and the like.

  The molded product of the present embodiment is not particularly limited. For example, extrusion molding, injection molding, vacuum molding, blow molding, injection compression molding, decorative molding, other material molding, gas assist injection molding, foam injection molding, low pressure molding It can be produced using a known molding method such as ultra-thin injection molding (ultra-high-speed injection molding) or in-mold composite molding (insert molding, outsert molding).

  EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention concretely, this invention is not limited at all by these.

  The raw material and the measuring method of the physical property of the resin composition of an Example and a comparative example are shown below.

〔raw materials〕
-Polyacetal resin (A)-
The temperature of a biaxial self-cleaning type polymerization machine (L / D = 8) with a jacket capable of passing a heating medium was adjusted to 80 ° C.
In the polymerization machine, trioxane as a monomer was 4 kg / hour, 1,3-dioxolane as a comonomer was 128.3 g / hour (3.9 mol% with respect to 1 mol of trioxane), methylal as a chain transfer agent was 690 mg / hour (trioxane). 0.20 × 10 ⁻³ mol) was continuously added to 1 mol.
Further, 153.4 mg / hour of boron trifluoride di-n-butyl etherate as a polymerization catalyst was continuously added to the polymerization machine (1.5 × 10 ⁻⁵ mol with respect to 1 mol of trioxane). Thus, the polymerization reaction was carried out continuously. The polyacetal copolymer discharged from the polymerization machine was put into a 0.1% triethylamine aqueous solution to deactivate the polymerization catalyst. The resulting polyacetal copolymer was filtered using a centrifuge and dried. The dried polyacetal copolymer is supplied to a twin screw extruder with a vent, and 0.5 parts by mass of water is added to 100 parts by mass of the polyacetal copolymer in the molten polyacetal copolymer in the extruder. Then, the conditions of the extruder were set at a temperature of 200 ° C. and the residence time was 7 minutes, and the unstable terminal portion (— (OCH ₂ ) _n —OH) of the polyacetal copolymer was decomposed and removed. The polyacetal copolymer from which the unstable terminal portion was decomposed and removed was devolatilized under a condition of a vent vacuum of 20 Torr, extruded as a strand from the die portion of the extruder, and pelletized. The obtained pellet was designated as polyacetal resin (A-1).

-Crystalline calcium silicate hydrate (B)-
After forming a slurry by dispersing silicon dioxide (manufactured by Nichetsu Co., Ltd., trade name: refined silica powder high silica F3) and calcium oxide (trade name: quick lime special trade name, manufactured by Kawai Lime Industry Co., Ltd.) in water, Tobermorite was prepared by curing under saturated steam at 190 ° C. for 15 hours using an autoclave. Here, the molar ratio of calcium oxide to silicon dioxide was 0.83, and the weight ratio of water to the total solid content of silicon dioxide and calcium oxide was 1.5. The tobermorite obtained was pulverized using a porcelain mortar (manufactured by Ishikawa Factory, trade name: Ishikawa-type stirring crusher 16). The ground tobermorite was used as crystalline calcium silicate hydrate (B-1).
The average particle size of the crystalline calcium silicate hydrate (B-1) was 45 μm. Further, when the crystalline calcium silicate hydrate (B-1) was observed using a scanning electron microscope, it was confirmed to be a mixture of a layered structure and a card house structure.
Also, wollastonite (manufactured by Sakai Kogyo Co., Ltd., trade name: NYAD1250, fiber length = 9 μm, fiber diameter = 3 μm, aspect ratio = 3) is used as crystalline calcium silicate hydrate (B-2) It was.

-Inorganic filler (X)-
X-1: Calcium carbonate (Shiraishi Kogyo Co., Ltd., trade name: Brilliant-15, primary particle: 150 nm)
X-2: Glass reinforcing fiber (manufactured by Central Glass Fiber Co., Ltd., trade name: ECS03-631K, cut length = 3 mm, fiber diameter = 13 μm)
X-3: Talc (made by Nippon Talc Co., Ltd., trade name: MS, particle diameter (D50) = 14 μm)

[Method for measuring physical properties]
(1) Mechanical properties The polyacetal resin compositions obtained in the following Examples and Comparative Examples were prepared by using an injection molding machine (manufactured by Toshiba Machine Co., Ltd., IS-100GN), cylinder temperature: 205 ° C., mold temperature. A test piece (dumbbell) compliant with ISO was produced by injection molding under the injection conditions of: 90 ° C., injection pressure: 100 MPa, injection time: 35 seconds, and cooling time: 15 seconds. About the produced test piece, based on ISO527, the tensile elongation and the tensile elasticity modulus were measured. The tensile elongation was calculated from the following formula.
Tensile elongation (%) = elongation to break (mm) / chuck interval (= 115 mm) × 100

(2) Discoloration in high-temperature molding An ISO-compliant test piece was prepared in the same manner as in the case of “(1) Mechanical properties” except that the cylinder temperature was 220 ° C. About the produced test piece, the yellowness (b value) was measured using the light source of D65, and the color difference meter (the Konica Minolta company make, brand name: CR-200).
Compared with the yellowness (b value) when the cylinder temperature is 205 ° C., the smaller the amount of change in the yellowness (b value) when the cylinder temperature is 220 ° C., the lower the yellowness level due to high temperature molding. It was determined to be small and have good discoloration in high temperature molding (excellent color tone characteristics due to heat). The determination was made in three stages according to the following criteria.
<Judgment Criteria: “Yellowness (b Value) Change: Determined”)>
Less than 0.5: ○, 0.5 or more and less than 1.5: Δ, 1.5 or more: ×

(3) Appearance of molded product By injection-molding the polyacetal resin compositions obtained in the following Examples and Comparative Examples in the same manner as in the case of “(1) Mechanical properties after immersion in hot water”. A flat (130 mm × 110 mm × 3 mm) test piece was prepared. About the produced test piece, the external appearance of the surface was determined visually. The determination was made in three stages according to the following criteria. As a judgment criterion, gloss, jetting, flow mark, etc., compared with the appearance of the surface of the base polyacetal resin were used.
<Judgment criteria “Appearance: Judgment”)>
The entire surface is glossy and jetting and flow marks are not seen: ○
There is gloss on the entire surface, and jetting and flow marks are seen on part of the surface:
There is no gloss on the entire surface, and jetting and flow marks can be seen: ×

  The resin composition of an Example and a comparative example is shown below.

Example 1
Using a Henschel mixer, 100 parts by mass of the polyacetal resin (A-1) obtained by the above method and 2 parts by mass of the crystalline calcium silicate hydrate (B-1) obtained by the above method are used. A mixture was obtained by mixing uniformly. This mixture is fed to a twin screw extruder with a vent (L / D = 30, screw diameter: 30 mm, set temperature: 200 ° C.) from the main feed port of the extruder, and then melt mixed at a screw rotation speed of 100 rpm. By smelting, a polyacetal resin composition was obtained. The obtained polyacetal resin composition was evaluated for mechanical properties, discoloration at high temperature molding, and appearance of molded products. The evaluation results are shown in Table 1.

(Examples 2 to 4)
A polyacetal resin composition was produced in the same manner as in Example 1 except that the blending ratio of the crystalline calcium silicate hydrate (B-1) was changed as shown in Table 1, and the polyacetal resin composition thus obtained was manufactured. The characteristics were evaluated. The evaluation results are shown in Table 1.

(Example 5)
Example 1 except that the crystalline calcium silicate hydrate (B-2) was used instead of the crystalline calcium silicate hydrate (B-1) and the blending ratio was changed as shown in Table 1. A polyacetal resin composition was produced in the same manner as described above, and the properties of the obtained polyacetal resin composition were evaluated. The evaluation results are shown in Table 1.

(Comparative Example 1)
Except not having used crystalline calcium silicate hydrate (B-1), the polyacetal resin composition was manufactured similarly to Example 1, and the characteristic of the obtained polyacetal resin composition was evaluated. The evaluation results are shown in Table 1.

(Comparative Example 2)
A polyacetal resin composition was produced in the same manner as in Example 1 except that the blending ratio of the crystalline calcium silicate hydrate (B-1) was changed as shown in Table 1, and the polyacetal resin composition thus obtained was manufactured. The characteristics were evaluated. The evaluation results are shown in Table 1.

(Comparative Example 3)
Except that the blending ratio of the crystalline calcium silicate hydrate (B-1) was changed as shown in Table 1, an attempt was made to produce a polyacetal resin composition in the same manner as in Example 1; A polyacetal resin composition was not obtained.

(Comparative Examples 4 and 5)
The polyacetal is the same as in Example 1 except that the calcium carbonate (X-1) is used without using the crystalline calcium silicate hydrate (B-1) and the blending ratio of each component is as shown in Table 1. The resin composition was manufactured, and the characteristics of the obtained polyacetal resin composition were evaluated. The evaluation results are shown in Table 1.

(Comparative Example 6)
The same as Example 1 except that the crystalline calcium silicate hydrate (B-1) was not used, the glass reinforcing fiber (X-2) was used, and the blending ratio of each component was changed as shown in Table 1. A polyacetal resin composition was manufactured in the same manner, and the properties of the obtained polyacetal resin composition were evaluated. The evaluation results are shown in Table 1.

(Comparative Example 7)
Polyacetal is the same as in Example 1 except that crystalline calcium silicate hydrate (B-1) is not used, talc (X-3) is used, and the blending ratio of each component is changed as shown in Table 1. The resin composition was manufactured, and the characteristics of the obtained polyacetal resin composition were evaluated. The evaluation results are shown in Table 1.

The evaluation results shown in Table 1 will be discussed below.
By comparing the polyacetal resin composition obtained in Examples 1 to 5 with the polyacetal resin composition obtained in Comparative Examples 1 to 7, crystalline calcium silicate hydrate (B-1) (tobermorite) ) And crystalline calcium silicate hydrate (B-2) (wollastonite) at a predetermined blending ratio, the tensile elastic modulus is improved and the decrease in tensile elongation is suppressed. It was confirmed that the balance of properties was good, the discoloration in high temperature molding was suppressed, and the appearance of the molded product was good.

  The polyacetal resin composition of the present invention has an effect that the mechanical properties are provided in a well-balanced manner, the discoloration in high temperature molding is suppressed, and the appearance of the molded product is excellent. The molded article of the present invention containing the polyacetal resin composition of the present invention is also suitably used in a wide range of fields such as automobiles, electricity, and electronics.

Claims (4)

Polyacetal resin (A);
A polyacetal resin composition comprising: 1.0 part by mass or more and 25.0 parts by mass or less of crystalline calcium silicate hydrate (B) with respect to 100 parts by mass of the polyacetal resin (A).   The polyacetal resin composition according to claim 1, wherein the crystalline calcium silicate hydrate (B) has a layered structure and / or a card house structure.   The polyacetal resin composition according to claim 1 or 2, wherein the crystalline calcium silicate hydrate (B) is tobermorite.   The molded article containing the polyacetal resin composition as described in any one of Claims 1-3.