WO2021039003A1 - Polyacetal resin composition and production method therefor - Google Patents

Abstract

The purpose of the present invention is to improve the mechanical strength of a polyacetal resin, in particular, the tensile strength and the bending strength.　The purpose of the present invention is achieved by a polyacetal resin composition that is obtained by blending at least: (A) 100 parts by mass of a polyacetal resin; (B) 0.01-1.0 part by mass of a hindered phenol-based antioxidant; (C) 1-100 parts by mass of a glass fiber; and (D) 0.1-20 parts by mass of a copolymer obtained by polymerizing (a) trioxane, (b) a cyclic acetal compound having an oxyalkylene group having 2 or more carbon atoms in a ring, and (c) a silicon compound having an alkoxy group bonded to silicon.

Description

Polyacetal resin composition and its manufacturing method

The present invention relates to a polyacetal resin composition having excellent mechanical properties and a method for producing the same.

It has been conventionally known to blend glass fiber in order to improve the mechanical strength of polyacetal resin. However, since the polyacetal resin has poor chemical activity, it is difficult to obtain a sufficient reinforcing effect even if glass fibers are simply mixed with the polyacetal resin and melt-kneaded.

In order to improve this point, a glass-based inorganic filler surface-treated with an epoxy-based compound, a silane-based compound, a titanate-based compound, or the like is used, or these compounds are used in combination with the glass-based inorganic filler. It has been proposed to blend (Patent Documents 1, 2 and 3).

Japanese Unexamined Patent Publication No. 62-91551 JP-A-61-236851 Japanese Unexamined Patent Publication No. 2018-100355

As in Patent Documents 1, 2 and 3, a method of blending a glass-based inorganic filler surface-treated with an epoxy-based compound, a silane-based compound, a titanate-based compound, or the like into a polyacetal resin, or using these compounds as a glass-based inorganic filler. The method of blending the polyacetal resin in combination with the polyacetal resin could not sufficiently improve the mechanical strength, particularly the tensile strength and the bending strength of the polyacetal resin, and was not yet satisfactory.

As described above, it has been difficult to impart a high degree of mechanical strength to the polyacetal resin by a conventionally known method.

An object of the present invention is to solve the problems of the prior art and to provide a polyacetal resin material having further excellent mechanical properties.

As a result of diligent studies to solve the problem and obtain a polyacetal resin composition having the above-mentioned excellent properties, the present inventor has confirmed that the problem is remarkably improved by a specific composition. The invention was completed.

An object of the present invention has been achieved by:
1. 1. at least,
(A) 100 parts by mass of polyacetal resin and
(B) Hindered phenolic antioxidant 0.01 to 1.0 parts by mass and
(C) 1 to 100 parts by mass of glass fiber
(D) (a) Trioxane and
(B) A cyclic acetal compound having an oxyalkylene group having 2 or more carbon atoms in the ring,
(C) A silicon compound containing an alkoxy group bonded to silicon.
0.1 to 20 parts by mass of the copolymer reacted with the polymerization reaction
A polyacetal resin composition containing.
2. 2. The compound (c) is
It has at least one trioxane copolymerizable functional group selected from an epoxy group and a cyclic acetal group and an alkoxysilyl group, and the trioxane copolymerizable functional group and the alkoxysilyl group are selected from a carbon-carbon bond or an ether bond. Compounds that are bound only by a binding chain,
The polyacetal resin composition according to 1 above.
3. 3. The compound (c) is
The polyacetal resin composition according to 1 or 2 above, which is at least one selected from 2- (3,4-epoxycyclohexyl) -ethyltrimethoxysilane and 2- (3,4-epoxycyclohexyl) -ethyltriethoxysilane. ..
4. The compound (c) is
The polyacetal resin composition according to 1 above, which is a condensate of one or more silane compounds selected from the compounds represented by the following formula (1) and is an organopolysiloxane having an alkoxy group.
R ¹ _n Si (OR ² ) _4-n (1)
(In the formula (1), R ¹ represents a monovalent hydrocarbon group, R ² represents an alkyl group having 4 or less carbon atoms, and n is an integer of 0 to 3.)
5. ^{The polyacetal resin composition according to 4 above, wherein R 1} in the formula (1) is at least one selected from a methyl group or a phenyl group.
6. The polyacetal resin composition according to any one of 1 to 5 above, further comprising (E) a triazine derivative having a nitrogen-containing functional group in an amount of 0.001 to 3 parts by mass with respect to 100 parts by mass of the (A) polyacetal resin.
7. The polyacetal resin composition according to any one of 1 to 6, wherein the polyacetal resin (A) is a polyacetal copolymer.

8. at least,
(A) 100 parts by mass of polyacetal resin and
(B) Hindered phenolic antioxidant 0.1 to 1.0 parts by mass and
(C) 1 to 100 parts by mass of glass fiber
(D) (a) a trioxane, (b) a cyclic acetal compound having an oxyalkylene group having 2 or more carbon atoms in the ring, and (c) a silicon compound containing an alkoxy group bonded to silicon.
0.1 to 20 parts by mass of the copolymer reacted with the polymerization reaction
A method for producing a polyacetal resin composition containing
A method for producing a polyacetal resin composition, wherein the copolymer (D) is a polyacetal copolymer obtained by using a cationic polymerization catalyst.
9. The method for producing a polyacetal resin composition according to 8 above, wherein the cationic polymerization catalyst is one or more selected from perfluoroalkanesulfonic acid, heteropolyacid, and isopolyacid.

According to the present invention, a polyacetal resin composition having further excellent mechanical properties is provided.

Hereinafter, specific embodiments of the present invention will be described in detail, but the present invention is not limited to the following embodiments, and the present invention is carried out with appropriate modifications within the scope of the object of the present invention. can do.

<Polyacetal resin composition>
The polyacetal resin composition of the present invention contains at least (A) a polyacetal resin, (B) a hindered phenolic antioxidant, (C) glass fiber, (D) (a) trioxane, and (b) 2 carbon atoms. It is characterized by containing a cyclic acetal compound having the above oxyalkylene group in the ring and a polyacetal copolymer obtained by polymerizing (c) a silicon compound containing an alkoxy group bonded to silicon.

<(A) Polyacetal resin>
Hereinafter, the constitution of the polyacetal resin composition of the present invention will be described in detail.
The (A) polyacetal resin, which is the base of the resin composition of the present invention, _{is a polymer compound having an oximethylene unit (-CH 2} O-) as a main constituent unit, and is an acetal homopolymer (for example, manufactured by Dupont, USA, etc.). (Commercial name "Delrin" etc.), acetal copolymers containing other comonomer units in addition to oxymethylene groups (for example, manufactured by Polyplastics Co., Ltd., trade name "Duracon" etc.) are included.

In the acetal copolymer, the comonomer unit contains an oxyalkylene unit having about 2 to 6 carbon atoms (preferably about 2 to 4 carbon atoms) (for example, an oxyethylene group (-CH ₂ CH ₂ O-), an oxypropylene group, or an oxy). Tetramethylene group, etc.) is included.

The content of the comonomer unit is generally 0.01 to 20 mol% as an amount that does not significantly impair the crystallinity and chemical stability of the resin, for example, as a ratio to the constituent units of the polyacetal polymer. , Preferably, it can be selected from the range of 0.03 to 10 mol%, and more preferably 0.1 to 7 mol%.

The acetal copolymer may be a copolymer composed of two components, a terpolymer composed of three components, or the like. The acetal copolymer may be a block copolymer, a graft copolymer or the like, in addition to a random copolymer.

Further, the degree of polymerization, the degree of bifurcation and the degree of cross-linking of the (A) polyacetal resin are not particularly limited as long as they can be melt-molded. As the polyacetal resin (A) blended in the present invention, an acetal copolymer is particularly preferable in terms of its thermal stability and the like.

≪ (B) Hindered phenolic antioxidant≫
The (B) hindered phenolic antioxidant that can be used in the present invention is not particularly limited, and is, for example, a monocyclic hindered phenol compound (for example, 2,6-di-t-butyl-p-. Cresol, etc.), polycyclic hindered phenolic compounds linked by groups containing hydrocarbon groups or sulfur atoms (eg, 2,2'-methylenebis (4-methyl-6-t-butylphenol), 4,4'- Methylenebis (2,6-di-t-butylphenol), 1,1,3-tris (2-methyl-4-hydroxy-5-t-butylphenyl) butane, 4,4'-butylidenebis (3-methyl-6) -T-butylphenol), 1,3,5-trimethyl-2,4,6-tris (3,5-di-t-butyl-4-hydroxybenzyl) benzene, 4,4'-thiobis (3-methyl-) 6-t-butylphenol), etc.), hindered phenol compounds having an ester group or an amide group (eg, n-octadecyl-3- (4'-hydroxy-3', 5'-di-t-butylphenyl) propionate, n-Octadecyl-2- (4'-hydroxy-3', 5'-di-t-butylphenyl) propionate, 1,6-hexanediol-bis [3- (3,5-di-t-butyl-4) -Hydroxyphenyl) propionate], triethylene glycol-bis [3- (3-t-butyl-5-methyl-4-hydroxyphenyl) propionate], pentaerythritol tetrakis [3- (3,5-di-t-butyl) -4-Hydroxyphenyl) propionate], 3,9-bis {2- [3- (3-t-butyl-4-hydroxy-5-methylphenyl) propionyloxy] -1,1-dimethylethyl} -2, 4,8,10-Tetraoxaspiro [5.5] undecane, 2-t-butyl-6- (3'-t-butyl-5'-methyl-2'-hydroxybenzyl) -4-methylphenylacrylate, 2- [1- (2-Hydroxy-3,5-di-t-pentylphenyl) ethyl] -4,6-di-t-pentylphenyl acrylate, di-n-octadecyl-3,5-di-t- Butyl-4-hydroxybenzylphosphonate, N, N'-hexamethylenebis (3,5-di-t-butyl-4-hydroxy-dihydrocinnamamide), N, N'-ethylenebis [3- (3,3) 5-Di-t-butyl-4-hydroxyphenyl) propionamide], N, N'-tetramethylenebis [3- (3) , 5-Di-t-Butyl-4-hydroxyphenyl) propionamide], N, N'-hexamethylenebis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionamide], N , N'-ethylenebis [3- (3-t-butyl-5-methyl-4-hydroxyphenyl) propionamide], N, N'-hexamethylenebis [3- (3-t-butyl-5-methyl) -4-Hydroxyphenyl) propionamide], N, N'-bis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionyl] hydrazine, N, N'-bis [3- (3) -T-Butyl-5-methyl-4-hydroxyphenyl) propionyl] hydrazine, 1,3,5-tris (3,5-di-t-butyl-4-hydroxybenzyl) isocyanurate, 1,3,5- Examples thereof include tris (4-t-butyl-3-hydroxy-2,6-dimethylbenzyl) isocyanurate.

In the present invention, at least one or two or more selected from these antioxidants can be used.

The content of the (B) hindered phenolic antioxidant in the present invention is 0.01 part by mass or more and 1 part by mass or less, preferably 0.02 part by mass or more, with respect to 100 parts by mass of the (A) polyacetal resin. It is 0.5 parts by mass or less.

(B) By setting the antioxidant in the above range, sufficient antioxidant properties can be obtained, and it is resistant to short-term oxidative deterioration at high temperatures such as during molding and oxidative deterioration under long-term use at room temperature. (A) The stability of the polyacetal resin is also sufficient, which is preferable.

<(C) Glass fiber>
Next, the glass fiber (C) used in the present invention has a single fiber diameter (minor diameter) of not particularly limited, but is particularly preferably 5 μm or more and 15 μm or less from the viewpoint of mechanical properties.
In this specification, the single fiber diameter of the glass fiber means the average value of the diameters of the cross sections of 25 filaments measured according to JIS R 3420.

The average fiber length (major axis) can be appropriately selected from 1 to 30 mm, and 1 to 10 mm is preferable. In this specification, the average fiber length is the average of the lengths of 100 arbitrarily selected glass fibers.
Since chopped strands are manufactured by bundling dozens to thousands of glass fibers and cutting them to a predetermined length, they are preferable in that the major axes of the glass fibers are uniform.

The glass fiber (C) used in the present invention does not ask whether or not the surface treatment is applied, but the glass fiber without the surface treatment may not stably produce the effect intended by the present invention. In order to stably achieve various properties, it is preferable to use one surface-treated with a coupling agent and a binding agent.

As the coupling agent, a titanate-based coupling agent or a silane-based coupling agent can be used.
Examples of the titanate-based coupling agent include titanium-i-propoxyoctylene glycolate, tetra-n-butoxytitanium, and tetrakis (2-ethylhexoxy) titanium.

Examples of the silane-based coupling agent include vinylalkoxysilane, epoxyalkoxysilane, aminoalkoxysilane, mercaptoalkoxysilane, and allylalkoxysilane.

Examples of the vinylalkoxysilane include vinyltriethoxysilane, vinyltrimethoxysilane, and vinyltris (β-methoxyethoxy) silane.
Examples of the epoxy alkoxysilane include γ-glycidoxypropyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, and γ-glycidoxypropyltriethoxysilane.

Examples of aminoalkoxysilanes include γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropylmethyldimethoxysilane, γ-aminopropylmethyldiethoxysilane, and N- (β-aminoethyl) -γ. -Aminopropyltrimethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane and the like can be mentioned.

Examples of the mercaptoalkoxysilane include γ-mercaptopropyltrimethoxysilane and γ-mercaptopropyltriethoxysilane.
Examples of the allylalkoxysilane include γ-diallylaminopropyltrimethoxysilane, γ-allylaminopropyltrimethoxysilane, and γ-allylthiopropyltrimethoxysilane.

As the binding agent, those using a polymer binder, an adhesion accelerator, other auxiliary agents, etc. are preferably used. As the polymer binder, generally known organic materials such as water-dispersible / water-soluble polyvinyl acetate, polyester, epoxide, polyurethane, polyacrylate or polyolefin resin, and mixtures thereof are preferably used.

In the present invention, the content of the glass fiber (C) is 1 to 100 parts by mass, preferably 5 to 90 parts by mass, particularly preferably 10 with respect to 100 parts by mass of the polyacetal resin (A) from the viewpoint of mechanical properties. ~ 70 parts by mass.

<(D) Polyacetal copolymer>
The (D) polyacetal copolymer of the present invention comprises at least (a) a trioxane, (b) a cyclic acetal compound having an oxyalkylene group having 2 or more carbon atoms in the ring, and (c) an alkoxy group bonded to silicon. It is characterized by being a polyacetal copolymer obtained by polymerizing a containing silicon compound.

≪ (a) Trioxan≫
The (a) trioxane used in the present invention is a cyclic trimer of formaldehyde, which is generally obtained by reacting an aqueous formaldehyde solution in the presence of an acidic catalyst, and is purified by a method such as distillation. Used for polymerization reaction.

<< (b) Cyclic acetal compound having an oxyalkylene group having 2 or more carbon atoms in the ring >>
In the present invention, (b) a cyclic acetal compound having an oxyalkylene group having 2 or more carbon atoms in the ring can be used as a comonomer.

The cyclic acetal compound having an oxyalkylene group having 2 or more carbon atoms in the ring of the present invention is a compound generally used as a comonomer in the production of a polyacetal copolymer. Specific examples thereof include 1,3-dioxolane, 1,3,6-trioxocan, 1,4-butanediol formal and the like.

In the present invention, the component (b) is preferably used in the range of 0.01 to 20 parts by mass with respect to 100 parts by mass of (a) trioxane, and more preferably 0.05 to 5 parts by mass. The range.

<< (c) Silicon compound containing an alkoxy group bonded to silicon >>
The silicon compound (c) containing an alkoxy group bonded to silicon used in the present invention is characterized by being a compound containing an alkoxy group bonded to silicon in the molecule, and among them, the following two compounds (c1) ( c2) is preferable.

<< (c1) It has at least one trioxane copolymerizable functional group and an alkoxysilyl group selected from an epoxy group and a cyclic acetal group, and the trioxane copolymerizable functional group and the alkoxysilyl group are carbon-carbon bonds or ethers. Compounds that are bound only by the binding chain selected from the bonds >>

The component (c1) used in the present invention has at least one trioxane copolymerizable functional group and an alkoxysilyl group selected from an epoxy group and a cyclic acetal group, and the trioxane copolymerizable functional group and the alkoxysilyl group are , A compound that is bound only by a bond chain selected from a carbon-carbon bond or an ether bond.

In the component (c1) of the present invention, the trioxane copolymerizable functional group and the alkoxysilyl group are bonded only by a bond chain selected from a carbon-carbon bond or an ether bond.

That is, it means that only a carbon chain or an ether bond exists between the trioxane copolymer functional group and the alkoxysilyl group. The distance is preferably 2 to 20 as the number of carbon atoms, and the number of ether bonds is preferably 0 to 5, and more preferably 0 to 2.

The component (c1) can be easily obtained as a silane coupling agent.
Preferred compounds are illustrated below. In addition, Me represents a methyl group and Et represents an ethyl group. Of these, the most preferable compounds are c1-1 (2- (3,4-epoxycyclohexyl) -ethyltrimethoxysilane) or c1-2 (2- (3,4-epoxycyclohexyl)) from the viewpoint of polymerization yield. -Ethyltriethoxysilane).

<< Organopolysiloxane obtained by condensing one or more silane compounds selected from the silane compounds represented by the formula (1) in (c2) and having an alkoxy group >>
R ¹ _n Si (OR ² ) _4-n (1)
(In the formula (1), R ¹ represents a monovalent hydrocarbon group, R ² represents an alkyl group having 4 or less carbon atoms, and n is an integer of 0 to 3.)

Examples of the silane compound represented by the formula (1) include phenyltrimethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, methyltripropoxysilane, methyltributoxysilane, ethyltrimethoxysilane, and ethyltriethoxysilane. Examples thereof include tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, tetrabutoxysilane, methylphenyldimethoxysilane, trimethylmethoxysilane, trimethylethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, diphenyldimethoxysilane, and diphenyldiethoxysilane. ..

The (c2) organopolysiloxane component used in the present invention is a known condensation reaction catalyst, specifically, an acid catalyst or a base catalyst, which comprises one or more silane compounds selected from the silane compounds represented by the formula (1). It is obtained by condensation using an organic metal compound catalyst or the like.

Specifically, for example, the (alkoxy) silane compound is partially hydrolyzed and condensed by the method described in Japanese Patent No. 2904317, Japanese Patent No. 3389338, etc., and contains an alkoxy group to the extent that the effect of the present invention is obtained. ..

The fact that the (c2) organopolysiloxane component of the present invention has an alkoxy group can be known by quantifying the alkoxy group in the organopolysiloxane. For example, ^{it can be quantified by 29} Si-NMR measurement or the amount of alcohol produced when KOH is added and thermally decomposed.

The (c2) organopolysiloxane component of the present invention is a compound containing an alkoxy group and optionally a hydrocarbon group and having a siloxane skeleton. Specific examples of the alkoxy group include a methoxy group, an ethoxy group, a propoxy group, and a butoxy group.

Specific examples of the above-mentioned hydrocarbon group include saturated hydrocarbon groups such as methyl group, ethyl group and propyl group, and aromatic hydrocarbon groups such as phenyl group and naphthyl group.

^{R 2} in the above formula (1) relating to the (c2) organopolysiloxane component of the present invention is preferably at least one selected from a methyl group and an ethyl group from the viewpoint of the mechanical properties of the obtained polyacetal resin composition.

^{Further, it is preferable that R 1} in the above formula (1) relating to the (c2) organopolysiloxane component is at least one selected from a methyl group or a phenyl group from the viewpoint of the mechanical properties of the obtained polyacetal resin composition.

Examples of commercially available products of the (c2) organopolysiloxane component of the present invention include "SR2402Resin", "AY42-163", "DC-3074intermediate" and "DC-3037intermediate" (all manufactured by Dow Toray Co., Ltd.). "KC-89S", "KR-500", "X-40-9225", "X-40-9246", "X-40-9250", "KR-9218", "KR-213", "KR" -510, "X-40-9227", "X-40-9247", "KR-401N" (all manufactured by Shin-Etsu Chemical Co., Ltd.) and the like.

In the present invention, the component (c) is preferably used in the range of 0.01 to 5 parts by mass with respect to 100 parts by mass of (a) trioxane, and more preferably 0.03 to 1 part by mass. The range.
In the present invention, the content of the (D) polyacetal copolymer is 0.1 to 20 parts by mass, preferably 1 to 20 parts by mass with respect to 100 parts by mass of the polyacetal resin (A) from the viewpoint of mechanical properties. is there.

<(D) Polymerization method of polyacetal copolymer>
The method for polymerizing the (D) polyacetal copolymer of the present invention comprises at least (a) a trioxane, (b) a cyclic acetal compound having an oxyalkylene group having 2 or more carbon atoms in the ring, and (c) an alkoxy group. It is characterized in that the contained silicon compound is polymerized in the presence of a cationic polymerization catalyst.

<Cationic polymerization catalyst>
As the cationic polymerization catalyst, a polymerization catalyst known for cationic copolymerization using trioxane as a main monomer can be used. Typical examples include Lewis acid and protonic acid. In particular, the following protonic acids are preferable.

≪Protonic acid≫
Examples of the protonic acid include perfluoroalkanesulfonic acid, heteropolyacid, and isopolyacid.
Specific examples of perfluoroalcan sulfonic acid include trifluoromethanesulfonic acid, pentafluoroethanesulfonic acid, heptafluoropropanesulfonic acid, nonafluorobutanesulfonic acid, undecafluoropentanesulfonic acid, tridecafluorohexanesulfonic acid, and pentadecafluoro. Examples thereof include heptane sulfonic acid and heptadecafluorooctane sulfonic acid.

Heteropolyacid refers to a polyacid produced by dehydration condensation of different types of oxygen acids, which is mononuclear or dinuclear formed by the presence of a specific different element in the center and the condensation of condensed acid groups sharing oxygen atoms. Has complex ions. The isopolyacid is also referred to as an isopolyxic acid, a homonuclear condensate acid, or an allogeneic multiplex acid, and refers to a high molecular weight inorganic oxygen acid composed of a condensate of an inorganic oxygen acid having a single type of metal having a V valence or a VI valence. ..

Specific examples of heteropolyacids include phosphomolybdic acid, phosphotungstic acid, phosphomolybdate tungstic acid, phosphomolybd vanadic acid, phosphomolybd tongue tungstic acid, phosphotungstic acid, silicate tungstic acid, silicate molybdate, and keimolybd. Examples thereof include tungstic acid and molybdate tungsten tungstic acid. In particular, from the viewpoint of polymerization activity, the heteropolyacid is preferably selected from silicolybdic acid, silicotungstic acid, phosphomolybdic acid, and phosphotungstic acid.

Specific examples of isopolyacids include isopolytungstic acid such as paratungstic acid and metatungstic acid, paramolybdic acid, isopolymolybdic acid such as metamolybdic acid, metapolyvanadium acid, and isopolyvanadium acid. And so on. Of these, isopolytungstic acid is preferable from the viewpoint of polymerization activity.

≪Lewis acid≫
Examples of Lewis acid include halides of boron, tin, titanium, phosphorus, arsenic and antimony, and specific examples thereof include boron trifluoride, tin tetrachloride, titanium tetrachloride, phosphorus pentafluoride and phosphorus pentafluoride. , Antimony pentafluoride and its complex compounds or salts.

The amount of the polymerization catalyst is not particularly limited, but is preferably 0.1 ppm or more and 50 ppm or less, and more preferably 0.1 ppm or more and 30 ppm or less with respect to the total of all the monomers. Particularly preferably, it is 0.1 ppm or more and 10 ppm or less. (Hereinafter, the unit ppm is the mass standard.)

The method for polymerizing the polyacetal copolymer (D) of the present invention is not particularly limited. The polymerization apparatus is not particularly limited in the production, and a known apparatus is used, and any method such as a batch type or a continuous type is possible. Moreover, it is preferable to keep the polymerization temperature at 65 ° C. or higher and 135 ° C. or lower.
The cationic polymerization catalyst is preferably diluted with an inert solvent that does not adversely affect the polymerization.

The deactivation of the polymerization catalyst after the polymerization can be carried out by a conventionally known method. For example, after the polymerization reaction, a basic compound or an aqueous solution thereof may be added to the product reaction product discharged from the polymerization machine or the reaction product in the polymerization machine.
The basic compound for neutralizing and inactivating the polymerization catalyst is not particularly limited. After polymerization and deactivation, if necessary, further washing, separation and recovery of unreacted monomers, drying and the like are carried out by conventionally known methods.

The molecular weight of the (D) polyacetal copolymer obtained as described above preferably has a weight average molecular weight equivalent to methyl polymethacrylate measured by size exclusion chromatography of 10,000 to 500,000, and particularly preferably 20,000 to 150,000. Is. As for the terminal group, the _{amount of hemiformal terminal group represented by −OCH 2} OH is preferably 0 to 4 mmol / kg, and particularly preferably 0 to 2 mmol / kg. The amount of hemiformal terminal groups ^{can be determined by 1} H-NMR measurement, and the specific measurement method thereof can be referred to the method described in JP-A-2001-11143.

In order to control the amount of hemiformal terminal groups within the above range, the amount of impurities in the total amount of monomers and comonomer to be polymerized, particularly water content, is preferably 20 ppm or less, particularly preferably 10 ppm or less.

<Various stabilizers / additives>
The polyacetal resin composition of the present embodiment may further contain various known stabilizers and additives. Examples of the stabilizer include one or more of a nitrogen-containing basic compound, an alkali or alkaline earth metal hydroxide, an inorganic salt, a carboxylate, and the like. As the additive, one or more of general additives for thermoplastic resins, for example, colorants such as dyes and pigments, lubricants, nucleating agents, mold release agents, antistatic agents, and surfactants are used. Can be mentioned.

Among them, the nitrogen-containing basic compound is used to enhance the heat resistance stability and mechanical properties of the polyacetal resin composition. The type of the nitrogen-containing basic compound is not particularly limited, and examples thereof include (E) a triazine derivative having a nitrogen-containing functional group.

(E) As the triazine derivative having a nitrogen-containing functional group, specifically, guanamine, melamine, N-butyl melamine, N-phenyl melamine, N, N-diphenyl melamine, N, N-diallyl melamine, N, N'. , N''-triphenylmelamine, benzoguanamine, acetoguanamine, 2,4-diamino-6-butyl-sim-triazine, amerin, 2,4-diamino-6-benzyloxy-sim-triazine, 2,4-diamino -6-Butoxy-sim-triazine, 2,4-diamino-6-cyclohexyl-sim-triazine, 2,4-diamino-6-chloro-sim-triazine, 2,4-diamino-6-mercapto-sim-triazine , 2,4-Dioxy-6-amino-sim-triazine, 2-oxy-4,6-diaminosym-triazine, 1,1-bis- (3,5-diamino-2,4,6-triazine) methane , 1,2-bis- (3,5-diamino2,4,6-triazineyl) ethane [also known as succinoguanamine], 1,3-bis- (3,5) -diamino-2,4,6 -Triazinyl) propane, 1,4-bis- (3,5-diamino-2,4,6-triazinyl) butane, melamine methylene, ethylenedimelamine, triguanamine, melaminecyanurate, ethylenedimelaminecyanurate, tri Guanamin cyanurate, etc.

These triazine derivatives may be used alone or in combination of two or more. Guanamin and melamine are preferable, and melamine is particularly preferable.

In the present embodiment, when the (E) triazine derivative having a nitrogen-containing functional group is contained, the content thereof is 0.001 to 3 parts by mass or less with respect to 100 parts by mass of the (A) polyacetal resin. It is preferably 0.01 to 2 parts by mass or less, and particularly preferably 0.03 to 1 part by mass or less. If the content of the triazine derivative (E) is 0.001 part by mass or more, the thermal stability of the polyacetal resin can be improved, and if it is 3 parts by mass or less, problems such as exudation from the polyacetal resin can occur. It is preferable because there is no such thing.

Further, as long as the performance of the molded product, which is the object of the present embodiment, is not significantly deteriorated, known inorganic, organic, metal and other fibrous, plate-like, powder-granular and the like other than glass fiber can be used. It is also possible to mix one kind or two or more kinds of fillers in combination. Examples of such fillers include, but are not limited to, talc, mica, wollastonite, carbon fibers, glass beads and the like.

<Manufacturing method of polyacetal resin composition>
In the production of the polyacetal resin composition of the present invention, an apparatus having a function of melting the polyacetal resin and the polyacetal copolymer and kneading them together with surface-treated glass fibers and the like, and preferably having a venting function is used. For example, a single-screw or multi-screw continuous extrusion kneader having at least one vent hole, a conider, and the like can be mentioned. For the melt-kneading treatment, the temperature range of the polyacetal resin and the polyacetal copolymer from the melting point to 260 ° C. is preferable. If the temperature is higher than 260 ° C., decomposition and deterioration of the polymer will occur, which is not preferable.

Hereinafter, the present invention will be specifically described with reference to Examples, but the present invention is not limited thereto.
The (D) polyacetal copolymer used in the examples was prepared as follows.

<Preparation of (D) polyacetal copolymer>
300 g of trioxane (TOX) (a) was placed in a closed autoclave having a jacket through which a heat medium could pass and a stirring blade, and further, 1,3-dioxolane (DO) as a component (b) and table as a component (c). The compounds described in 1 were added so as to have parts by mass shown in Table 1. These contents are stirred, and after keeping the internal temperature at about 80 ° C. by passing hot water at 80 ° C. through the jacket, phosphotungstic acid (PWA) is used as a catalyst in the form of a methyl formate solution by the masses of (a) and (b). 4.5 ppm or trifluoromethanesulfonic acid (TfOH) was added in the form of a cyclohexane solution to the sum of the masses of (a) and (b) at 1.0 ppm, and the polymerization reaction was carried out.

The component (c) used in the examples was (c1-1) 2- (3,4-epoxide cyclohexyl) -ethyltrimethoxysilane (trade name: KBM-303), (c1-2) 2- (3,4). -Epoxide cyclohexyl) -Ethyltriethoxysilane (reagent; manufactured by Tokyo Kasei Kogyo Co., Ltd.), (c2-1) ^{Trade name: KR-500 (R 1} : methyl group, R ² : methyl group), (c2-2) ) Trade name: KR-401N (R ¹ : methyl group / phenyl group, R ² : methyl group) (all except (c1-2) are manufactured by Shin-Etsu Chemical Industry Co., Ltd.).

After 5 minutes, 300 g of water containing 1000 ppm of triethylamine was added to this autoclave to stop the reaction, and the contents were taken out and pulverized to 200 mesh or less. Then, after washing with acetone, it was dried to obtain a (D) polyacetal copolymer.

<Examples and Comparative Examples>
<Preparation of polyacetal resin composition>
The various components shown in Table 2 are mixed in the amount of addition (unit: parts by mass) shown in Table 2, melt-kneaded at a cylinder temperature of 200 ° C. using a twin-screw extruder with a vent, and the present invention relates to Examples and Comparative Examples. A pellet-shaped polyacetal resin composition was prepared.
The various components used in Examples and Comparative Examples of the present invention shown in Table 2 are as follows.

(A) Polyacetal resin A polyacetal copolymer obtained by copolymerizing 96.7% by mass of trioxane and 3.3% by mass of 1,3-dioxolane (melt index (measured at 190 ° C. and a load of 2160 g according to ISO1133)). : 9g / 10min)
(B) Hindered phenolic antioxidant Irganox245 (manufactured by BASF)
Triethylene glycol-bis [3- (3-t-butyl-5-methyl-4-hydroxyphenyl) propionate]
(C) Glass fiber Chopped strand with average fiber minor axis 9 μm and average fiber major axis 3 mm, surface treatment agent: aminosilane coupling agent, binding agent: urethane surface-treated (D) polyacetal copolymer Table 1 (D-1) to (D-6) of the above were used.
(E) Triazine derivative melamine having a nitrogen-containing functional group

<Evaluation>
The evaluation items and evaluation methods for mechanical properties in the examples are as follows. The results are shown in Table 2.
[Tensile test]
The tensile strength (TS) of the ISO Type1A test piece was measured according to ISO527-1,2. The measurement room maintained an atmosphere of 23 ° C. and 50% RH. The unit of numerical value is MPa.
[Bending test]
Bending strength (FS) and flexural modulus (FM) conforming to ISO178 were measured as mechanical properties. The conditions of the measurement room were 23 ° C. and 50% RH. The unit of numerical value is MPa.

From the evaluation of mechanical properties in Table 2, it can be seen that the resin composition of the present invention is excellent in mechanical properties (tensile strength, bending strength, flexural modulus).

Claims (9)

at least,
(A) 100 parts by mass of polyacetal resin and
(B) Hindered phenolic antioxidant 0.01 to 1.0 parts by mass and
(C) 1 to 100 parts by mass of glass fiber
(D) (a) Trioxane and
(B) A cyclic acetal compound having an oxyalkylene group having 2 or more carbon atoms in the ring,
(C) A silicon compound containing an alkoxy group bonded to silicon.
0.1 to 20 parts by mass of the copolymer reacted with the polymerization reaction
A polyacetal resin composition containing. The compound (c) is
It has at least one trioxane copolymerizable functional group selected from an epoxy group and a cyclic acetal group and an alkoxysilyl group, and the trioxane copolymerizable functional group and the alkoxysilyl group are selected from a carbon-carbon bond or an ether bond. Compounds that are bound only by a binding chain,
The polyacetal resin composition according to claim 1. The compound (c) is
The polyacetal resin composition according to claim 1 or 2, which is at least one selected from 2- (3,4-epoxycyclohexyl) -ethyltrimethoxysilane and 2- (3,4-epoxycyclohexyl) -ethyltriethoxysilane. Stuff. The compound (c) is
It is a condensate of one or more silane compounds selected from the compounds represented by the following formula (1), and is an organopolysiloxane having an alkoxy group.
The polyacetal resin composition according to claim 1.
R ¹ _n Si (OR ² ) _4-n (1)
(In the formula (1), R ¹ represents a monovalent hydrocarbon group, R ² represents an alkyl group having 4 or less carbon atoms, and n is an integer of 0 to 3.) ^{R 1} in the formula (1) is at least one selected from a methyl group or a phenyl group.
The polyacetal resin composition according to claim 4. Further, (E) a triazine derivative having a nitrogen-containing functional group is contained in an amount of 0.001 to 3 parts by mass with respect to 100 parts by mass of the (A) polyacetal resin.
The polyacetal resin composition according to any one of claims 1 to 5. The polyacetal resin composition according to any one of claims 1 to 6, wherein the polyacetal resin (A) is a polyacetal copolymer. at least,
(A) 100 parts by mass of polyacetal resin and
(B) Hindered phenolic antioxidant 0.1 to 1.0 parts by mass and
(C) 1 to 100 parts by mass of glass fiber
(D) (a) a trioxane, (b) a cyclic acetal compound having an oxyalkylene group having 2 or more carbon atoms in the ring, and (c) a silicon compound containing an alkoxy group bonded to silicon.
0.1 to 20 parts by mass of the copolymer reacted with the polymerization reaction
A method for producing a polyacetal resin composition containing
A method for producing a polyacetal resin composition, wherein the copolymer (D) is a polyacetal copolymer obtained by using a cationic polymerization catalyst. The method for producing a polyacetal resin composition according to claim 8, wherein the cationic polymerization catalyst is one or more selected from perfluoroalkanesulfonic acid, heteropolyacid, and isopolyacid.