JP2006282903A - Resin composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polyoxymethylene resin composition having excellent impact resistance without damaging appearance of its molding, its molding, and its part. <P>SOLUTION: This polyoxymethylene resin composition contains 5-60 parts by weight modified olefinic polymer (B) and 0-10 parts by weight lubricant (C) to 100 parts by weight total polyoxymethylene resin composition (A) containing 100-50 wt.% polyoxymethylene copolymer (a-1) containing a hydroxyalkyl group on the end of the molecule and 0-50 wt.% oxymethylene resin (a-2), and the Mooney viscosity of the component (B) is 5-60 ML<SB>1+4</SB>at 100&deg;C. <P>COPYRIGHT: (C)2007,JPO&amp;INPIT

Description

  The present invention relates to a composition that retains rigidity and molded appearance in a polyoxymethylene resin with improved toughness, and further has excellent weld properties, and a molded body using the composition, a precision device, a home appliance OA device, and an automobile. , Parts for industrial materials and miscellaneous goods.

  Polyoxymethylene resins are widely used as engineering resins with balanced mechanical properties in various mechanical parts, office automation equipment, and the like. However, polyoxymethylene resin does not have sufficient toughness depending on the application to which it is applied, and in order to improve this, a method of adding a component that imparts flexibility has been made, but the strength and elongation of the weld part have been increased. There was a problem of lowering.

  As a method of adding a component that imparts flexibility, for example, a technique of adding an olefin polymer or an α-olefin polymer (see, for example, Patent Document 1) is known. However, since the olefin polymer or α-olefin polymer used and the polyoxymethylene resin lack affinity, the resulting composition tends to peel off in layers, and even if a molded product is obtained, the appearance is poor. May occur. Further, in the injection molded product, the strength / elongation of the weld part is lowered, so that it is often seen as a starting point of fracture.

  Therefore, various methods for improving the affinity between the polyoxymethylene resin and the olefin polymer have been proposed. For example, a technique using a polar group-containing α-olefin polymer such as an ethylene-vinyl acetate copolymer and an ethylene-acrylic acid copolymer is known (for example, see Patent Document 2). However, since the affinity is still insufficiently improved, the toughness is not expressed and the rigidity is lowered, the thermal stability of the polyoxymethylene resin is lowered, a form odor is generated during granulation, and foaming is said to occur. There is a problem, and the problem has not been solved completely.

  In addition, a technique of adding a liquid α-olefin or an isocyanate compound in order to increase affinity (for example, see Patent Document 3) is known. However, the improvement in toughness is insufficient with respect to the amount added, and new problems such as bleeding in the molded body and coloring of the molded body have occurred.

Japanese Patent Publication No.41-2730 Japanese Patent Publication No.43-22669 JP 2002-030197 A

  An object of the present invention is to provide a composition having excellent weld properties while maintaining the rigidity and molding appearance of a polyoxymethylene resin with improved toughness, and a molded article and a part formed by molding the composition. And

The present inventor has modified a polyoxymethylene resin and an olefin polymer with a polyoxymethylene copolymer having a hydroxylalkyl group at a terminal, a carboxylic acid having a specific plasticity, or an acid anhydride thereof. It has been found that when an olefin polymer is used, stable mixing is possible and the affinity between polymers is improved. As a result, a polyoxymethylene copolymer composition having improved toughness while maintaining an excellent molded appearance was obtained, and the composition was found to have excellent weld characteristics, thereby completing the present invention.
That is, this invention relates to the polyoxymethylene resin composition and molded object which have the following structure.

[1] Polyoxymethylene resin (A) 100 parts by weight, modified olefin polymer (B) 5 to 60 parts by weight and lubricant (C) 0 to 10 parts by weight. 100 to 50% by weight of a polyoxymethylene copolymer (a-1) containing an alkyl group and having a hydroxyalkyl group terminal concentration of 5 × 10 ⁻⁵ mol or more per mol of oxymethylene units and an oxymethylene resin (a- 2) It is 0 to 50% by weight, the component (B) contains 20% by weight or more of an olefin polymer having a modifying group of 0.01 to 8% by weight, and its Mooney viscosity is 5 to 60 ML _{1 + 4} 100 ° C. A polyoxymethylene resin composition [2] characterized in that the polyoxymethylene copolymer (a-1) is converted into at least one quaternary ammonium compound represented by the following [Formula 1]: Using things, polyoxymethylene resin composition according to processing the thermally unstable end, characterized in that the stabilized [1].

(In the formula, R ₁ , R ₂ , R ₃ , and R ₄ each independently represent an unsubstituted alkyl group or substituted alkyl group having 1 to 30 carbon atoms, an aryl group having 6 to 20 carbon atoms, or 1 to 1 carbon atoms. An aralkyl group in which 30 unsubstituted alkyl groups or substituted alkyl groups are substituted with at least one aryl group having 6 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms has at least one carbon atom having 1 to 30 carbon atoms Represents an unsubstituted alkyl group or an alkylaryl group substituted with a substituted alkyl group, and the unsubstituted alkyl group or substituted alkyl group is linear, branched, or cyclic, the above-mentioned unsubstituted alkyl group, aryl group, aralkyl group; In the alkylaryl group, a hydrogen atom may be substituted with a halogen, n represents an integer of 1 to 3. X is a hydroxyl group, or a carboxylic acid having 1 to 20 carbon atoms, a hydrogen acid, an oxo acid inorganic thioacid. Or, it represents an acid residue of an organic thioacid having 1 to 20 carbon atoms.)
[3] A polymer having a number average molecular weight of 400 or more, wherein the polyoxymethylene copolymer (a-1) has at least one hydroxyl group, carboxyl group, amino group, ester group, or alkoxy group. The polyoxymethylene resin composition according to [1] or [2], which is a polyoxymethylene block copolymer obtained by chain transfer.
[4] The polyoxymethylene block copolymer according to [3], wherein the polyoxymethylene block copolymer is a polyoxymethylene copolymer having a number average molecular weight of 10,000 to 500,000 represented by the following [Formula 2]. Methylene resin composition.

(In the formula, other than A (referred to as B block) is m = 2 to 98 mol%, n = 2 to 98 mol%, m + n = 100 mol%, and m is present randomly or in blocks with respect to n. hydrogenated liquid polybutadiene residue at both ends was hydroxyalkylated with a number average molecular weight of 500 to 10,000. However, B block may be those having the following unsaturated bond iodine value _20g-I 2 / 100g. k is an integer selected from 2 to 6, and two k's may be the same or different, and R is selected from hydrogen, an alkyl group, a substituted alkyl group, an aryl group, and a substituted aryl group. The A block is a polyoxymethylene copolymer residue represented by the following [Formula 3].

(R ′ is selected from hydrogen, an alkyl group, a substituted alkyl group, an aryl group, and a substituted aryl group, and each may be the same or different. J is an integer selected from 2 to 6. x = 95 to 99.9 mol%, y = 5 to 0.1 mol%, x + y = 100 mol%, y is present randomly with respect to x.) In [Formula 2], the average number average molecular weight of the two A blocks 5,000 to 250,000. )
[5] The modified olefin polymer (B) is dispersed in the polyoxymethylene resin (A), and 60% or more of the dispersed particles have a minor axis diameter of 3 μm or less. 4]. The polyoxymethylene resin composition according to any one of [4].
[6] The modified olefin polymer (B) contains at least 20 wt% or more of an olefin polymer modified by 0.01 to 8 wt% with a carboxylic acid or an acid anhydride thereof [1] To [5], a polyoxymethylene resin composition according to any one of
[7] Obtained by substantially mixing the polyoxymethylene copolymer (a-1), the modified olefin polymer (B) and the lubricant (C) and then mixing the oxymethylene resin (a-2). The polyoxymethylene resin composition according to any one of [1] to [6], wherein
[8] A molded article obtained by subjecting the polyoxymethylene resin composition according to any one of [1] to [7] to injection molding, gas injection molding, multilayer injection molding, extrusion molding or blow molding .

  The present invention is a composition that retains the rigidity and molding appearance of a polyoxymethylene resin with improved toughness and has excellent weld characteristics. When the composition of the present invention is used, it is a precision instrument, home appliance OA apparatus, automobile. Suitable for parts in industrial materials and sundries.

Details of the present invention will be described below.
[Component (A)-(a-1) Polyoxymethylene Copolymer]
The polyoxymethylene copolymer used as the component (a-1) will be described. The polyoxymethylene copolymer is obtained by polymerizing cyclic oligomers such as formaldehyde, its trimer trioxane or tetramer tetraoxane, and containing 80 mol% or more of oxymethylene units, and other 20 mol% or less. Polymers having, as components, ethylene oxide, propylene oxide, 1,3-dioxolane, cyclic ethers such as glycol formal, diglycol formal, and / or hydroxyl group, carboxyl group, amino group, ester group, alkoxy group Obtained by copolymerization and / or block copolymerization thereof.

Furthermore, the molecular end of the polyoxymethylene copolymer particularly contains a hydroxyalkyl group, and the hydroxyalkyl group end concentration is preferably 5 × 10 ⁻⁵ mol or more per 1 mol of oxymethylene unit. More preferably, it is 10 × 10 ⁻⁵ mol or more, and further preferably 30 × 10 ⁻⁵ mol or more. There are various methods for adjusting the hydroxyalkyl group terminal concentration in the polyoxymethylene copolymer. For example, water, alcohol (for example, methanol or ethylene glycol), acid (for example, formic acid) or the like may be chain-transferred. A polymer containing a hydroxyl group, a carboxyl group, an amino group, an ester group, or an alkoxy group may be chain-transferred. Moreover, you may add formal, such as a methylal, as needed.

  Particularly preferred is a polyoxymethylene block copolymer obtained by chain transfer of a polymer having a hydroxyl group-containing molecular weight of 500 to 10,000, such as polyethylene having one or both terminal hydroxyl groups, hydrogenated polybutadiene, hydrogenated poly It is a polyoxymethylene block copolymer using isoprene or the like. More preferably, it is a polyoxymethylene copolymer having a number average molecular weight of 10,000 to 500,000 represented by the following [Formula 2].

(In the formula, other than A (referred to as B block) is m = 2 to 98 mol%, n = 2 to 98 mol%, m + n = 100 mol%, and m is present randomly or in blocks with respect to n. hydrogenated liquid polybutadiene residue at both ends was hydroxyalkylated with a number average molecular weight of 500 to 10,000. However, B block may be those having the following unsaturated bond iodine value _20g-I 2 / 100g. k is an integer selected from 2 to 6, and two k's may be the same or different, and R is selected from hydrogen, an alkyl group, a substituted alkyl group, an aryl group, and a substituted aryl group. The A block is a polyoxymethylene copolymer residue represented by the following [Formula 3].

(R ′ is selected from hydrogen, an alkyl group, a substituted alkyl group, an aryl group, and a substituted aryl group, and each may be the same or different. J is an integer selected from 2 to 6. x = 95 to 99.9 mol%, y = 5 to 0.1 mol%, x + y = 100 mol%, y is present randomly with respect to x.) In [Formula 2], the average number average molecular weight of the two A blocks 5,000 to 250,000. )

The terminal concentration of hydroxyalkyl groups in the polyoxymethylene copolymer is less than 5 × 10 ⁻⁵ mole per mole of oxymethylene from the viewpoint of compatibility with the thermoplastic elastomer.
As the polymerization catalyst, cationically active catalysts such as Lewis acids, proton acids and esters or anhydrides thereof are preferable. Examples of the Lewis acid include boric acid, tin, titanium, phosphorus, arsenic and antimony halides. Specifically, boron trifluoride, tin tetrachloride, titanium tetrachloride, phosphorus pentafluoride, pentachloride. Examples thereof include phosphorus, antimony pentafluoride, and complex compounds or salts thereof. Specific examples of the protonic acid, its ester or anhydride include perchloric acid, trifluoromethanesulfonic acid, perchloric acid-tertiary butyl ester, acetyl perchlorate, trimethyloxonium hexafluorophosphate, and the like. Among these, boron trifluoride; boron trifluoride hydrate; and a coordination complex compound of an organic compound containing an oxygen atom or a sulfur atom and boron trifluoride are preferable. Specifically, boron trifluoride diethyl ether is used. Boron trifluoride di-n-butyl ether can be cited as a preferred example. The amount of these polymerization catalysts used is 1 × 10 ⁻⁶ mol to 1 mol per 1 mol of the total amount of trioxane and cyclic ether and / or cyclic formal. × 10 ⁻³ mol is preferable, and 5 × 10 ⁻⁶ mol to 1 × 10 ⁻⁴ mol is more preferable.

  Although there is no restriction | limiting in particular as a polymerization method, For example, block polymerization can be mentioned, This block polymerization may be any of a batch type and a continuous type. In this bulk polymerization, a monomer in a molten state is generally used, and a solid bulk polymer is obtained as the polymerization proceeds.

  The polymerization catalyst in the polymerized polyoxymethylene copolymer is deactivated by converting the polyoxymethylene copolymer obtained by the above polymerization reaction into amines such as ammonia, triethylamine, tri-n-butylamine, or alkali. It is generally charged for several minutes in a slurry state after being put into an aqueous solution or organic solvent solution containing at least one catalyst neutralization deactivator such as a metal or alkaline earth metal hydroxide, inorganic acid salt, or organic acid salt. It is performed by stirring for several hours. The slurry after deactivation of the catalyst neutralization is dried after filtration and washing to remove unreacted monomers, the catalyst neutralization deactivator, and the catalyst neutralization deactivation salt.

  Also, a method of deactivating the polymerization catalyst by contacting a vapor such as ammonia or triethylamine with a polyoxymethylene copolymer, or a polyoxymethylene copolymer with at least one of hindered amines, triphenylphosphine, calcium hydroxide, and the like. A method of deactivating the catalyst by contacting the polymer with a mixer can also be used.

  Next, terminal stabilization treatment of the polyoxymethylene copolymer after deactivation of the polymerization catalyst will be described. Examples of the method for decomposing and removing the unstable end include ammonia, aliphatic amines such as triethylamine and tributylamine, hydroxylation using a single screw extruder with a vent and a twin screw extruder with a vent. In the presence of a basic substance capable of decomposing known unstable terminals such as hydroxides, inorganic weak acid salts, and organic weak acid salts of alkali metals or alkaline earth metals represented by calcium, polyoxymethylene copolymer The polymer can be melted and the unstable ends can be decomposed and removed.

  Particularly preferred is a method of treating a thermally unstable terminal with at least one quaternary ammonium compound represented by the following [Formula 1], and the polyoxy stabilized by the above method. Almost unstable terminal portions remain in the methylene copolymer.

(In the formula, R ₁ , R ₂ , R ₃ , and R ₄ each independently represent an unsubstituted alkyl group or substituted alkyl group having 1 to 30 carbon atoms; an aryl group having 6 to 20 carbon atoms; An aralkyl group having 30 unsubstituted alkyl groups or substituted alkyl groups substituted with at least one aryl group having 6 to 20 carbon atoms; or an aryl group having 6 to 20 carbon atoms having at least one carbon atom having 1 to 30 carbon atoms Represents an unsubstituted alkyl group or an alkylaryl group substituted with a substituted alkyl group, and the unsubstituted alkyl group or substituted alkyl group is linear, branched, or cyclic, the above-mentioned unsubstituted alkyl group, aryl group, aralkyl group; In the alkylaryl group, a hydrogen atom may be substituted with a halogen, n represents an integer of 1 to 3. X is a hydroxyl group, or a carboxylic acid having 1 to 20 carbon atoms, a hydrogen acid, an oxo acid inorganic thioacid. Or, it represents an acid residue of an organic thioacid having 1 to 20 carbon atoms.)

  Specific examples of the quaternary ammonium salt compounds include tetramethylammonium, tetraethylammonium, tetrapropylammonium, tetra-n-butylammonium, cetyltrimethylammonium, tetradecyltrimethylammonium, 1,6-hexamethylenebis. (Trimethylammonium), decamethylene-bis- (trimethylammonium), trimethyl-3-chloro-2-hydroxypropylammonium, trimethyl (2-hydroxyethyl) ammonium, triethyl (2-hydroxyethyl) ammonium, tripropyl (2-hydroxy) Ethyl) ammonium, tri-n-butyl (2-hydroxyethyl) ammonium, trimethylbenzylammonium, triethylbenzylammonium, trip Pyrbenzylammonium, tri-n-butylbenzylammonium, trimethylphenylammonium, triethylphenylammonium, trimethyl-2-oxyethylammonium, monomethyltrihydroxyethylammonium, monoethyltrihydroxyethylammonium, okdadecyltri (2-hydroxyethyl) Examples thereof include hydroxides such as ammonium and tetrakis (hydroxyethyl) ammonium.

Hydrohalates other than halogenated, such as hydrogen azide; sulfuric acid, nitric acid, phosphoric acid, carbonic acid, boric acid, chloric acid, iodic acid, silicic acid, perchloric acid, chlorous acid, hypochlorous acid, chlorosulfuric acid Oxo acid salts such as amidosulfuric acid, disulfuric acid and tripolyphosphoric acid; thioic acid salts such as thiosulfuric acid; formic acid, acetic acid, propionic acid, butanoic acid, isobutyric acid, pentanoic acid, caproic acid, caprylic acid, capric acid, benzoic acid And carboxylates such as oxalic acid. Among them, hydroxide (OH ⁻ ), sulfuric acid (HSO ₄ ⁻ , SO ₄ ²⁻ ), carbonic acid (HCO ₃ ⁻ , CO ₃ ²⁻ ), boric acid (B (OH) ₄ ⁻ ), and carboxylic acid salts are included. preferable. Of the carboxylic acids, formic acid, acetic acid, and propionic acid are particularly preferred. These quaternary ammonium compounds may be used alone or in combination of two or more. The addition amount of the quaternary ammonium compound is 0.05 to 50 ppm by weight in terms of the amount of nitrogen derived from the quaternary ammonium compound represented by the following [Formula 1] with respect to the polyoxymethylene copolymer. It is.
P × 14 / Q ... [Formula 1]
(In the formula, P represents the concentration (weight ppm) of the quaternary ammonium compound relative to the polyoxymethylene copolymer, 14 represents the atomic weight of nitrogen, and Q represents the molecular weight of the quaternary ammonium compound.)

Melting is performed, for example, with a vented short screw extruder, a vented twin screw extruder, or the like. The temperature is not lower than the melting point of the polyoxymethylene copolymer and not higher than 260 ° C. The quaternary ammonium compound may be added in advance before the polyoxymethylene copolymer is melted, or may be added to the melted polyoxymethylene copolymer.
In the present invention, ammonia, triethylamine, a boric acid compound or the like, which is a known stabilizer for stabilizing unstable terminals, may be used in combination.

[Component (A)-(a-2) Oxymethylene resin]
The oxymethylene resin used as the component (a-2) will be described. The oxymethylene resin is not necessarily an essential component, but is preferably blended in order to control the dispersed particle size of the modified olefin polymer that imparts improved molding appearance and toughness. The oxymethylene resin used as the component (a-2) is a polymer compound having an oxymethylene unit as a main repeating structural unit, and is a so-called polyacetal homopolymer obtained by homopolymerizing formaldehyde, trioxane, or tetraoxane, or the single amount thereof. The polymer may be a copolymer of ethylene oxide, propion oxide, 1,3-dioxolane, or a so-called polyacetal copolymer. The oxymethylene resin here can be manufactured according to a well-known method similarly to (a-1) component.

The melt index MFR (measured under the conditions of ASTM-D1238-57T) of the component (a-2) oxymethylene resin is 0.5 to 100.0 g / 10 minutes, preferably 1.0 to 80.0 g / 10 minutes. It is.
When blending, in order to maintain thermal stability, it is preferable to perform catalyst deactivation and terminal stabilization treatment similar to the component (a-1).
Moreover, in order to improve toughness at the time of mixing | blending, it is preferable to mix | blend a component (a-2), after (a-1) component, (B) component, and (C) component are mixed substantially.

[Component (B)]
The modified olefin polymer used as the component (B) will be described.
The modified olefin polymer refers to a polymer containing 20% by weight or more of an olefin copolymer having a modifying group with respect to the polyolefin polymer.
As the modifying group having, carboxylic acid or its acid anhydride is preferable, and as its component unit, acrylic acid, methacrylic acid, α-ethylacrylic acid, maleic acid, fumaric acid, itaconic acid, citraconic acid, tetrahydrophthalic acid, Endocis-bicyclo [2,2,1] hept-5-ene-2,3dicarboxylic acid (nadic acid), methyl-endocis-bicyclo [2,2,1] hept-5-ene-2,3 dicarboxylic acid ( Unsaturated carboxylic acids such as methyl nadic acid), anhydrides of the unsaturated carboxylic acids, specifically maleic anhydride, citraconic anhydride, itaconic anhydride, tetrahydrophthalic anhydride, nadic anhydride, methyl nadic anhydride, etc. It is done. In these, unsaturated dicarboxylic acid or its acid anhydride is preferable, and also maleic acid or maleic anhydride is especially preferable. The amount of modification is 0.01% by weight or more based on the polyolefin polymer as the base material from the viewpoint of affinity with the polyoxymethylene resin, and 8% by weight or less is appropriate from the viewpoint of thermal stability. is there.

  The olefin polymer that is the base material of the modified olefin polymer is a homopolymer of an olefin monomer such as polyethylene, polypropylene, polybutylene, polyisobutylene, and ethylene, propylene, butene-1, pentene-1, 4-methyl. Pentene-1, hexene-1, heptene-1, octene-1, nonene-1, decene-1, undecene-1, dodecene-1, tridecene-1, tetradecene-1, pentadecene-1, hexadecene-1, heptadecene-1 , Octadecene-1, nonadecene-1, or eicosene-1, aliphatic substituted vinyl monomers such as isobutylene, aromatic vinyl monomers such as styrene and substituted styrene, vinyl acetate, acrylic ester, methacrylic ester, glycidyl acrylic acid Esters, glycidylme Ester-based vinyl monomers such as acrylic acid ester and hydroxyethyl methacrylate, nitrogen-containing vinyl monomers such as acrylamide, allylamine, vinyl-p-aminobenzene, acrylonitrile, butadiene, cyclopentadiene, 1,4-hexadiene, isoprene, etc. These are α-olefin polymers and other copolymers composed of one or more of the components listed as dienes.

Further, this olefin polymer is preferably produced using a single site catalyst, and the single site catalyst is referred to as JP-B-4-12283, JP-A-60-35006, JP-A-60-35007. , JP-A-60-35008, JP-A-63-280703, JP-A-5-155930, JP-A-3-163088, and US Pat. No. 5,272,236. It is a catalyst having uniform properties of active sites such as a metallocene catalyst containing 1 to 3 molecules of pentadienyl or substituted cyclopentadienyl and a catalyst by geometric control.
The preferred cyclopentadienyl or substituted cyclopentadienyl content is 1 to 2 molecules. Furthermore, the metal component used more preferably is titanium, zirconium, silicon, or hafnium.

  Specific preferred metallocene catalysts include cyclopentadienyl zirconium trichloride, pentamethylcyclopentadienyl zirconium trichloride, bis (cyclopentadienyl) zirconium dichloride, bis (cyclopentadienyl) zirconium monomethyl monochloride, bis (Methylcyclopentadienyl) zirconium dichloride, bis (pentamethylcyclopentadienyl) zirconium dichloride, bis (ethylcyclopentadienyl) zirconium dichloride, bis (cyclopentadienyl) zirconium dialkyl, bis (cyclopentadienyl) Zirconium diphenyl, dimethylsilyl dicyclopentadienyl zirconium dimethyl, methylphosphine dicyclopentadienyl zirconium dimethyl Zirconium compounds such as bis (indenyl) titanium diphenyl, bis (cyclopentadienyl) titanium dialkyl, bis (cyclopentadienyl) titanium diphenyl, bis (methylcyclopentadienyl) titanium dialkyl, bis (1,2- Hafnium such as dimethylcyclopentadienyl) titanium diphenyl, titanium compounds such as bis (1,2-dimethylcyclopentadienyl) titanium dichloride, bis (cyclopentadienyl) hafnium dichloride, bis (cyclopentadienyl) hafnium dimethyl Compounds and vanadium compounds such as bis (cyclopentadienyl) vanadium dichloride.

  Specific preferred geometrically controlled catalysts include (tertiary butylamide) (tetramethyl-η5-cyclopentadienyl) -1,2-ethanediylzirconium dichloride, (tertiary butylamide)-( Tetramethyl-η5-cyclopentadienyl) -1,2-ethanediyltitanium dichloride, (methylamide) (tetramethyl-η5-cyclopentadienyl) -1,2-ethanediylzirconium dichloride, (methylamide) (tetramethyl) -Η5-cyclopentadienyl) -1,2-ethanediyltitanium dichloride, (ethylamide) (tetramethyl-η5-cyclopentadienyl) -methylenetitanium dichloride, (tertiary butylamide) dimethyl- (tetramethyl-η5 -Cyclopentadienyl) silane titanium dic Ride, (tertiary butylamido) dimethyl (tetramethyl-η5-cyclopentadienyl) silane zirconium dibenzyl, (benzylamido) dimethyl (tetramethyl-η5-cyclopentadienyl) silane titanium dichloride, (phenylphosphide) Examples include dimethyl (tetramethyl-η5-cyclopentadienyl) silane zirconium dibenzyl.

Further, the single site catalyst in the present invention can use a cocatalyst at the same time. As specific promoters, those described in the above publication can be used. Preferred cocatalysts include organoaluminum oxy compounds having an alkyloxyaluminum unit as a repeating unit such as methylaluminoxane and ethylaluminoxane, organoaluminum compounds such as alkylaluminum and trialkylaluminum, [Bu ₃ NH] [B (C ₆ H ₄ R) ₄ ], C ₂ B ₉ H ₁₃ , water, Lewis acid, ammonium salt and the like.
Among the olefin polymers produced using the single-site catalyst, a copolymer of ethylene and one or more α-olefins having 3 to 20 carbon atoms is particularly preferable.

The compounding amount of the component (B) is 5 parts by weight or more from the viewpoint of imparting toughness with respect to 100 parts by weight of the component (A), and 60 parts by weight or less is necessary from the viewpoint of rigidity. Preferably it is 10-50 weight part.
Two or more kinds of the modified olefin polymers of the component (B) may be used in combination. The effects of the present invention cannot be obtained sufficiently if the blending amount and modification amount of the modified olefin polymer are not appropriate.

The modified olefin polymer is preferably a solid at normal temperature in handling, but it is preferable that the Mooney viscosity is 5 ML _{1 + 4} 100 ° C. or higher in order to maintain the quantitativeness at the time of measurement. Thereby, blocking is suppressed, and even if a dusting material is used, only a small amount is required, and the influence on the final physical properties is reduced. In order to maintain weld characteristics, the Mooney viscosity is preferably 50 ML _{1 + 4} 100 ° C. or less. The excellent plasticity improves the toughness and molded appearance because the dispersed particles become fine. Here, Mooney viscosity is a test stipulated by ASTM, and the notation unit ML _{1 + 4} 100 ° C evaluates plasticity by rotating the rotor after 1 minute of preheating and reading the gauge after 4 minutes at the time of evaluation at 100 ° C. It is a thing.

  In addition, the glass transition temperature of the modified olefin polymer is preferably −10 ° C. or less, more preferably −20 ° C. or less, from the viewpoint of improving toughness. Furthermore, from the viewpoint of stability, when a weight loss due to thermal decomposition using a thermobalance is measured in a nitrogen stream at a heating rate of 10 ° C./min, it has a weight retention of 75% or more at 350 ° C. A modified olefin polymer is preferred.

  In order to maintain the rigidity of the oxymethylene resin and to impart toughness, the component (B) is changed to the component (A) polyoxy by blending the lubricant (a-2) or the lubricant (C), devising the granulation conditions, etc. It must be present in a dispersed phase in the form of spheres and spheres overlapping in the methylene component.

  When the elastomer particles are dispersed in a spherical shape, from the viewpoint of molding appearance and weld characteristics, the minor axis diameter of the dispersed particles is preferably 60% or more of the particles is 3 μm or less, more preferably 2 μm or less, More preferably, it is 1 μm or less. Here, 60% of the particles means that when the minor axis diameter of arbitrarily sampled n representative particles (n ≧ 50) is examined, n × 0.6 or more is 3 μm or less (n = In the case of 50, 30 or more are 3 μm or less). When the elastomer particles are overlapped (having a network structure or a salami structure), 60% or more of the thickness (width) of the elastomer is preferably 3 μm or less, more preferably 2 μm or less, and even more preferably 1 μm. It is as follows. Here, 60% of the thickness means that 60% of the thickness of the arbitrarily measured mesh portion is 3 μm or less.

[Component (C)]
Although the component (C) lubricant is not necessarily required, it improves the fluidity between the polymer of the modified olefin polymer and the polyoxymethylene copolymer at the time of melt-kneading, and adjusts the dispersed particle size. It is preferable to blend in order to efficiently impart. Furthermore, since the resin temperature at the time of melt-kneading can be lowered, it is preferable to blend from the viewpoint that a decrease in the thermal stability of the polyoxymethylene resin due to shearing heat generation is suppressed. The amount added is preferably 10 parts by weight or less from the viewpoint of stability during granulation and retention of rigidity.

  The lubricant may be either an internal lubricant or an external lubricant, and it is preferable to add one or more of these. As used herein, the internal lubricant is one that dissolves in the modified olefin resin, reduces friction between resin molecules, and improves fluidity. The external lubricant is less soluble in the resin but forms a lubricating layer between the metal and the resin and between the resin and the resin to improve the fluidity.

  For example, various alcohols, ketones, aliphatic hydrocarbons, halogenated hydrocarbons such as solvents, polyoxyalkylene glycols, olefin compounds having an average polymerization degree of 10 to 5000, and modified products thereof, paraffin oil And paraffin wax, silicone oil, silicone gum, polyolefin compounds such as polyolefin graft silicone obtained by gently grafting silicone gum onto polyolefin, other oils, tertiary amines or derivatives thereof, quaternary ammonium salts or derivatives thereof, aliphatic alcohols Esters of fatty acids and fatty acids, esters of fatty alcohols and dicarboxylic acids, esters of glycerin and other short chain fatty alcohols and esters of fatty acids and oligomers of fatty acids, fatty acid amides and amide waxes Scan, metallic soaps such as higher fatty acid metal salts, zinc oxide or other zinc compounds, fluorine-based polymer, water and the substance, such as those obtained by adding water. Among these, silicone oil is preferable.

[Other additives]
In the polyoxymethylene resin composition of the present invention, stabilizers used in conventional polyoxymethylene resins, such as heat stabilizers and weathering (light) stabilizers, can be used alone or in combination.
As heat stabilizers, antioxidants, formaldehyde and formic acid scavengers, and combinations thereof are effective.

The antioxidant is preferably a hindered phenol antioxidant, such as 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), triethyleneglycol-bis- (3- (3-t-butyl-5-methyl-4-hydroxyphenyl) -propionate ) I am.
Tetrakis- (methylene-3- (3 ′, 5′-di-t-butyl-4′-hydroxyphenyl) propionate methane, 3,9-bis (2- (3- (3-t-butyl) -4-hydroxy-5-methylphenyl) propionyloxy) -1,1-dimethylethyl) 2,4,8,10-tetraoxaspiro (5,5) undecane, N, N'-bis-3- (3 '5'-di-t-butyl-4-hydroxyphenol) priionyl hexamethylenediamine, N, N'-tetramethylenebis-3- (3'-methyl-5'-t-butyl-4-hydroxyphenol) ) Propionyldiamine, N, N′-bis- (3- (3,5-di-tert-butyl-4-hydroxyphenol) propionyl) hydrazine, N-salicyloyl-N′-salicylidenehydrazine, 3- (N - Chiroiru) amino-1,2,4 - there - (butyl-4-hydroxyphenyl) propionyloxy 2- (3- (3,5-di) ethyl) Oxyamide etc. Le, N, N'-bis.

  Among these hindered phenolic antioxidants, triethylene glycol-bis- (3- (3-tert-butyl-5-methyl-4-hydroxyphenyl) -propionate), tetrakis- (methylene-3- (3 ′ , 5'-di-t-butyl-4'-hydroxyphenyl) propionate methane is preferred.

  Examples of formaldehyde and formic acid scavengers include (a) compounds and polymers containing formaldehyde-reactive nitrogen, (b) alkali metal or alkaline earth metal hydroxides, inorganic acid salts, carboxylate salts, or alkoxides. It is done.

  (I) Examples of the compound containing formaldehyde-reactive nitrogen include (1) dicyandiamide, (2) amino-substituted triazine, and (3) a co-condensate of amino-substituted triazine and formaldehyde.

(2) Examples of amino-substituted triazines include guanamine (2,4-diamino-sym-triazine), melamine (2,4,6-triamino-sym-triazine), N-butylmelamine, N-phenylmelamine, N , N-diphenylmelamine, N, N-diallylmelamine, N, N ′, N ″ -triphenylmelamine, N-methylolmelamine, N, N′-dimethylolmelamine, N, N ′, N ″ -tri Methylolmelamine and benzoguanamine (2,4-diamino-6-phenyl-sym-triazine).
2,4-diamino-6-methyl-sym-triazine, 2,4-diamino-6-butyl-sym-triazine, 2,4-diamino-6-benzyloxy-sym-triazine, 2,4-diamino -6-butoxy-sym-triazine, 2,4-diamino-6-cyclohexyl-sym-triazine, 2,4-diamino-6-chloro-sym-triazine, 2,4-diamino-6-mercapto-sym-triazine 2,4-dioxy-6-amino-sym-triazine (Amelite), 2-oxy-4,6-diamino-sym-triazine (Ameline), N, N ′, N′-tetracyanoethylbenzoguanamine and the like.

  (3) Examples of the cocondensate of amino-substituted triazine and formaldehyde include melamine-formaldehyde polycondensate. Of these, dicyandiamide, melamine and melamine-formaldehyde polycondensate are preferred.

  Further, (a) polymers having formaldehyde-reactive nitrogen groups include (1) polyamide resin, (2) acrylamide and derivatives thereof, or acrylamide and derivatives thereof and other vinyl monomers in the presence of metal alcoholates. (3) Polymer obtained by polymerizing acrylamide and its derivative or acrylamide and its derivative and other vinyl monomer in the presence of radical polymerization, (4) Nitrogen such as amine, amide, urea and urethane Polymers containing groups may also be used.

  As the polyamide resin of (1), nylon 4-6, nylon 6, nylon 6-6, nylon 6-10, nylon 6-12, nylon 12, etc. and copolymers thereof, for example, nylon 6 / 6-6, Nylon 6 / 6-6 / 6-10, nylon 6 / 6-12, etc. are mentioned.

  Examples of the polymer obtained by polymerizing acrylamide and derivatives thereof (2) or acrylamide and derivatives thereof and other vinyl monomers in the presence of a metal alcoholate include poly-β-alanine copolymers. These polymers are described in JP-B-6-10259 (corresponding to US Pat. No. 5,015,707), JP-B-5-87096, JP-B-5-47568 and JP-A-3-234729. It can be manufactured by the method.

  (3) Polymers obtained by polymerizing acrylamide and derivatives thereof or acrylamide and derivatives thereof with other vinyl monomers in the presence of radical polymerization are disclosed in JP-A-3-28260 (corresponding to US Pat. No. 5,011,890). ) Can be produced by the method described.

  (B) Alkali metal or alkaline earth metal hydroxide, inorganic acid salt, carboxylate or alkoxide, for example, hydroxide such as sodium, potassium, magnesium, calcium or barium, carbonate of the above metal, Examples include phosphates, silicates, borates, and carboxylates. The carboxylic acid of the carboxylate is a saturated or unsaturated aliphatic carboxylic acid having 10 to 36 carbon atoms, and these carboxylic acids may be substituted with a hydroxyl group. Examples of saturated aliphatic carboxylic acids include capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid, behenic acid, lignoceric acid, serotic acid, montanic acid, melicic acid, and celloplastic acid. Examples of the unsaturated aliphatic carboxylic acid include undecylenic acid, oleic acid, elaidic acid, celetic acid, erucic acid, brassic acid, sorbic acid, linoleic acid, linolenic acid, arachidonic acid, propiolic acid, stearic acid and the like. Examples of the alkoxide include methoxide and ethoxide of the above metals.

  Among them, the fatty acid is preferably myristic acid, palmitic acid, and stearic acid, and the metal compound is calcium hydroxide, oxide, and chloride. Specific examples of fatty acid metal salts include calcium dimyristic acid, calcium dipalmitate, calcium distearate, (myristic acid-palmitic acid) calcium, (myristic acid-stearic acid) calcium, and (palmitic acid-stearic acid). It is calcium. Of these, calcium dipalmitate and calcium distearate are preferable.

  In the present invention, two or more fatty acid metal salts may be added at the same time, and there is no limitation. For example, calcium stearate and calcium palmitate may be added simultaneously, or a metal salt composed of fatty acids having different carbon numbers, for example, (palmitic acid-stearic acid) calcium may be mixed. The method for producing the fatty acid metal salt is not particularly limited, and a fatty acid metal salt having a substantially unreacted metal compound of 500 ppm by weight or less is preferable.

  For example, a crude fatty acid metal salt obtained by a neutralization reaction between a fatty acid and a metal hydroxide, a metathesis reaction between a fatty acid and a metal chloride, or a neutralization reaction between a fatty acid and a metal oxide is further washed with water and dried. By performing the treatment, a desired fatty acid metal salt used in the present invention can be obtained. The unreacted metal compound in the obtained fatty acid metal salt is obtained by ultrasonically treating the fatty acid metal salt, quantifying the metal component extracted into the filtrate by atomic absorption, and using the obtained quantitative value as a raw material metal hydroxide. It can be calculated in terms of metal oxide or metal chloride.

  Further, a hydrazide compound may be added to reduce the amount of formaldehyde generated. The hydrazide compound used in the present invention is preferably a dicarboxylic acid dihydrazide represented by the following [formula 4], and malonic acid dihydrazide, succinic acid dihydrazide, glutaric acid dihydrazide, adipic acid dihydrazide, pimelic acid dihydrazide, superic acid dihydrazide, azelaic acid Examples include dihydrazide, sebacic acid dihydrazide, dodecanedioic acid dihydrazide, isophthalic acid dihydrazide, and phthalic acid dihydrazide.

(Wherein R is a hydrocarbon having 2 to 20 carbon atoms)
Of these dicarboxylic acid dihydrazides, preferred are sebacic acid dihydrazide, dodecanedioic acid dihydrazide, and isophthalic acid dihydrazide, and more preferred is sebacic acid dihydrazide. The addition amount of the hydrazide compound is 0.01 to 5 parts by weight with respect to 100 parts by weight of the oxymethylene resin of the present invention. Preferably it is 0.03-3 weight part. Moreover, melting | fusing point of a hydrazide compound is 160-250 degreeC, Preferably it is 170-230 degreeC, More preferably, it is 175-225 degreeC.

  As the weathering (light) stabilizer, (i) a benzotriazole-based material, (b) an oxalic acid anilide-based material, and (c) a hindered amine-based material are preferable. (I) Examples of the benzotriazole-based substance include 2- (2′-hydroxy-5′-methyl-phenyl) benzotriazole, 2- [2′-hydroxy-3,5-di-t-butyl-phenyl] benzo Triazole, 2- [2′-hydroxy-3,5-di-isoamyl-phenyl] benzotriazole, 2- [2′-hydroxy-3,5-bis- (α, α-dimethylbenzyl) phenyl] -2H— Examples include benzotriazole, 2- (2′-hydroxy-4′-octoxyphenyl) benzotriazole, and preferably 2- [2′-hydroxy-3,5-bis- (α, α-dimethylbenzyl) phenyl. ] -2H-benzotriazole, 2- [2'-hydroxy-3,5-di-t-butyl-phenyl] benzotriazole.

  (B) Examples of oxalic acid anilide-based substances include 2-ethoxy-2′-ethyloxalic acid bisanilide, 2-ethoxy-5-tert-butyl-2′-ethyloxalic acid bisanilide, 2 -Ethoxy-3'-dodecyl oxalic acid bisanilide and the like. These substances may be used alone or in combination of two or more.

(C) As hindered amine substances, 4-acetoxy-2,2,6,6-tetramethylpiperidine, 4-stearoyloxy-2,2,6,6-tetramethylpiperidine, 4-acryloyloxy-2,2 , 6,6-tetramethylpiperidine, 4- (phenylacetoxy) -2,2,6,6-tetramethylpiperidine 4-benzoyloxy-2,2,6,6-tetramethylpiperidine, 4-methoxy-2, Examples include 2,6,6-tetramethylpiperidine and 4-stearyloxy-2,2,6,6-tetramethylpiperidine.
In addition, 4-cyclohexyloxy-2,2,6,6-tetramethylpiperidine, 4-benzyloxy-2,2,6,6-tetramethylpiperidine, 4-phenoxy-2,2,6,6-tetramethyl Piperidine, 4- (ethylcarbamoyloxy) -2,2,6,6-tetramethylpiperidine, 4- (cyclohexylcarbamoyloxy) -2,2,6,6-tetramethylpiperidine, 4- (phenylcarbamoyloxy)- 2,2,6,6-tetramethylpiperidine, bis (2,2,6,6-tetramethyl-4-piperidine) -carbonate, bis (2,2,6,6-tetramethyl-4-piperidyl)- Oxalate, bis (2,2,6,6-tetramethyl-4-piperidyl) -malonate, bis (2,2,6,6-tetramethyl-4-piperi Le) - sebacate, bis (2,2,6,6-tetramethyl-4-piperidyl) - adipate, bis (2,2,6,6-tetramethyl-4-piperidyl) - terephthalate and the like.

  Furthermore, 1,2-bis (2,2,6,6-tetramethyl-4-piperidyloxy) -ethane, α, α′-bis (2,2,6,6-tetramethyl-4-piperidyloxy) ) -P-xylene, bis (2,2,6,6-tetramethyl-4-piperidyl) tolylene-2,4-dicarbamate, bis (2,2,6,6-tetramethyl-4-piperidyl)- Hexamethylene-1,6-dicarbamate, tris (2,2,6,6-tetramethyl-4-piperidyl) -benzene-1,3,5-tricarboxylate, tris (2,2,6,6- Tetramethyl-4-piperidyl) -benzene-1,3,4-tricarboxylate and the like, and bis (2,2,6,6-tetramethyl-4-piperidyl) -sebacate is preferred.

  The above hindered amine materials may be used alone or in combination of two or more. A combination of at least one of the above benzotriazole-based materials and oxalic acid anilide-based materials and a hindered amine-based material is most preferable.

  Furthermore, the polyoxymethylene resin composition of the present invention is, as desired, various inorganic fillers, other thermoplastic resins, softeners, crystal nuclei conventionally used in polyoxymethylene resins as long as the object of the present invention is not impaired. Agents, mold release agents, dyes, pigments and the like can be used.

  The inorganic filler may be fibrous, powdery, plate-like, or hollow. Examples of fibrous fillers include glass fiber, asbestos fiber, carbon fiber, silica fiber, silica / alumina fiber, zirconia fiber, boron nitride fiber, silicon nitride fiber, boron fiber, potassium titanate fiber, stainless steel, aluminum, titanium, Examples thereof include inorganic fibers such as copper, brass, and other metal fibers. Also included are whiskers such as potassium titanate, zinc oxide, and titanium oxide with short fiber lengths, and acicular wollastonite (calcium silicate).

  Powdery fillers include carbon black, silica, quartz powder, glass beads, glass powder, aluminum silicate, kaolin, talc, clay, diatomaceous earth, nepheline sinite, cristobalite, wollastonite (calcium silicate), iron oxide, oxidation Examples thereof include titanium, alumina, calcium sulfate, barium sulfate, calcium carbonate, magnesium carbonate, dolomite, calcium phosphate, hydroxyapatite, silicon carbide, silicon nitride, boron nitride, and various metal powders.

Examples of the plate-like filler include mica, glass flakes, and various metal foils. Examples of the hollow filler include glass balloons, silica balloons, shirasu balloons, metal balloons and the like, and these fillers can be used alone or in combination of two or more.
In addition, these fillers can be used either surface-treated or non-surface-treated, but the use of surface-treated ones in terms of the smoothness and mechanical properties of the molded product surface. It may be preferable. A conventionally well-known thing can be used as a surface treating agent. For example, various coupling treatment agents such as silane, titanate, aluminum, and zirconium can be used. Specifically, N- (2-aminoethyl) -3-aminopropyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, isopropyl trisstearoyl titanate, diisopropoxyammonium ethyl acetate, n-butyl zirconate, etc. can give.

  The method for producing the composition of the present invention can use a generally used melt kneader. Examples of the melt kneader include a kneader, a roll mill, a single screw extruder, a twin screw extruder, and a multi screw extruder. The processing temperature at this time is preferably 180 to 230 ° C., and in order to maintain the quality and the working environment, it is preferable to perform deaeration by substitution with an inert gas or single-stage and multistage vents.

As described above, the composition of the present invention can be molded by gas injection molding to obtain a hollow molded body or a gas fine dispersion molded body. Thereby, dimensional stability, molding stability, weight reduction, etc. are attained.
Furthermore, a molded product having two or more layers is formed by bonding the composition and various resins (regardless of methods such as ultrasonic bonding, high frequency bonding, hot plate bonding, hot press molding, multilayer injection molding, and multilayer blow molding). Thus, it is possible to impart excellent performance (toughness, rigidity, slidability, chemical resistance, gasoline permeation resistance, etc.) of various resins and maintain the excellent characteristics of the polyacetal resin.

  The composition of the present invention is at least one part selected from the group consisting of a structural part or a mechanical part obtained by molding, cutting, or molding / cutting, a resin part of an outsert chassis, a chassis, a tray, and a side plate. It is preferable that the mechanism component is used as at least one selected from the group consisting of a gear, a cam, a slider, a lever, an arm, a clutch, a joint, a shaft, a bearing, a key stem, and a key top.

  Furthermore, the applications in which these parts are used include OA equipment represented by printers and copiers, video equipment represented by VTR and video movies, cassette players, LD, MD, CD (including CD-ROM, CD-). R, CD-RW), DVD (including DVD-ROM, DVD-R, DVD-RAM, DVD-Audio), music, video, or information equipment represented by navigation systems and mobile computers, represented by mobile phones and facsimiles Communication equipment, clips, through anchors, tongues, fuel tanks, automotive interior and exterior parts represented by fuel tank peripheral parts, disposable cameras, toys, fasteners, conveyors, buckles, and industrial goods represented by residential equipment, etc. Can be given.

The present invention will be specifically described based on examples.
Hereinafter, the present invention will be described specifically by way of examples. First, contents of components used in Examples and Comparative Examples and evaluation methods are shown below.

[Contents of ingredients used]
(A) Component <A-1>
A jacketed biaxial paddle type continuous polymerization apparatus that allows heat medium to pass through is adjusted to 80 ° C., and trioxane with water + formic acid = 4 ppm is fed at 40 mol / hr, and 1,3-dioxolane as cyclic formal is simultaneously supplied. Was added at 2 mol / Hr, and boron trifluoride di-n-butyl etherate dissolved in cyclohexane as a polymerization catalyst was adjusted to 10 × 10 ⁻⁵ mol per 1 mol of trioxane, and the chain transfer agent was as follows. Polymerization was carried out by continuously feeding hydroxylated hydrogenated polybutadiene (Mn = 3390) of [Formula 5] to 2 × 10 ⁻³ mol per 1 mol of trioxane.

  After the polymer discharged from the polymerization machine is put into a 1% aqueous solution of triethylamine to completely deactivate the polymerization catalyst, the polymer is filtered and washed, and 1 part by weight of the crude polyoxymethylene copolymer after filtration and washing On the other hand, triethyl (2-hydroxyethyl) ammonium formate is added as a quaternary ammonium compound using the above [Formula 1] so as to be 20 ppm by weight in terms of the amount of nitrogen, and mixed uniformly. And then dried at 120 ° C.

  Next, triethylene glycol-bis [3- (3-t-butyl-5-methyl-4-hydroxyphenyl) propionate] was added as an antioxidant to 100 parts by weight of the dried crude polyoxymethylene copolymer. .3 parts by weight were added and fed to a vented twin screw extruder. 0.5% by weight of water was added to the molten oxymethylene copolymer in the extruder, and the unstable end portion was decomposed at a setting temperature of the extruder of 200 ° C. and a residence time of 5 minutes. The polyoxymethylene copolymer having the unstable terminal portion decomposed was degassed under reduced pressure under a condition of 21 KPa, then extruded as a strand from the extruder die portion and pelletized with a cutter to obtain a sample. The sample thus obtained was subjected to molecular weight measurement and terminal hydroxyalkyl group quantification.

<A-2>
Water + formic acid = 40 ppm of trioxane 40 mol / Hr, and at the same time, 1,3-dioxolane was fed as cyclic formal at 2 mol / Hr, and both ends hydroxyl group polyethylene (Mn = 5000) as chain transfer agent was 1 mol of trioxane. Samples were prepared and quantified in the same manner as in <A-1>, except that the polymerization was carried out by continuously feeding to 1.0 × 10 ⁻³ mol with respect to 1 mol.

<A-3>
As chain transfer agents, hydroxylated hydrogenated polybutadiene (Mn = 3390) at both ends was 1 × 10 ⁻³ mol per 1 mol of trioxane, and further methylal [(CH ₃ O) ₂ CH ₂ ] was 1 × per mol of trioxane. Samples were prepared and quantified in the same manner as in <A-1> except that polymerization was carried out by continuously feeding to 10 ⁻³ mol.

<A-4>
Similar to [A-1] except that methylal [(CH ₃ O) ₂ CH ₂ ] is continuously fed as a chain transfer agent so as to be 2 × 10 ⁻³ mol per 1 mol of trioxane for polymerization. The sample was prepared and quantified by operating.

<A-5>
<A-1> The same operation as described in <A-1>, except that methylal [(CH ₃ O) ₂ CH ₂ ] is continuously fed as a chain transfer agent to 3 × 10 ⁻³ mol per mol of trioxane for polymerization. The sample was prepared and quantified.

<A-6>
Without adding a quaternary ammonium compound, in addition to water in an extruder, triethylamine was added so as to be 50 ppm by weight in terms of nitrogen using the above [Formula 1], The same operations as in <A-1> were performed, and samples were prepared and quantified.

<A-7>
Instead of the quaternary ammonium compound, the same operation as in <A-1> was performed except that calcium hydroxide was added to 0.1 wt% to the obtained crude polyoxymethylene copolymer, Samples were prepared and quantified.

(B) Component <B-1>
Using (tertiary butylamide) (tetramethyl-η5-cyclopentadienyl) -1,2-ethanediyltitanium dichloride as a catalyst, the molar ratio of ethylene-octene is obtained by the method described in JP-A-3-163088. A modified olefin copolymer obtained by graft-polymerizing a reactive substance shown in Table 2 to 100 parts by weight of an ethylene-octene copolymer produced in 80/20 at a ratio in the same table.

<B-2-6>
A modified olefin copolymer produced by the composition and ratio shown in Table 2 in the same manner as <B-1> and graft-polymerized to the reactive substances and ratios in the table.

<B-7>
An ethylene-octene copolymer produced in the same manner as <B-1> without grafting a reactive substance.

[Evaluation methods]
(1) Molding appearance <Visual appearance evaluation>
After the pellets were dried at 100 ° C. for 3 hours, a 3 mm thick flat plate was molded at a mold temperature of 70 ° C. with a Nestal injection molding machine (manufactured by Sumitomo Heavy Industries, Ltd.) set at a cylinder temperature of 200 ° C. The flat plate was visually evaluated. The case where it was good in use was marked as ◎, the case where there was no problem in using such as glossiness and avatar was marked as △, and the case where the molding appearance such as silver and foreign matter was lowered was marked as x.

(2) Evaluation of physical properties After the pellets were dried at 80 ° C. for 3 hours, a mold temperature of 70 ° C. was cooled using a 5-ounce molding machine (IS-100E manufactured by Toshiba Machine Co., Ltd.) set at a cylinder temperature of 200 ° C. A test piece for evaluating physical properties was molded under the condition of time 30 seconds. The following test was done using this test piece. Evaluation was performed at n = 5, and an average value was shown.
<Bending elastic modulus>
The elastic modulus measured based on ASTM D790 is shown.
<Tensile elongation>
Based on ASTM D638, the crosshead speed was measured at 50 mm / min, and the degree of elongation relative to the chuck was shown.

(3) Dispersed particle morphology Using the molded product used for measuring physical properties in (2) above, the center of the molded product was cut at right angles to the flow direction, and the dispersion state of the elastomer was measured using a transmission electron microscope. I took a picture. Based on this photograph, the short axis diameter of 50 randomly selected dispersed particles was examined to determine the short axis diameter of the particles.

(4) Weld characteristics The injection gates are provided on both sides with the same shape as the dumbbell for tensile elongation measurement, and the weld part is forcibly used by using a mold designed so that the weld position is between the dumbbell marks. Samples were prepared and their characteristics were evaluated. Evaluation was performed at n = 5, and the weld elongation was measured based on ASTM D638 at a crosshead speed of 5 mm / min.

[Example 1]
<A-1> 100 parts by weight as a polyoxymethylene copolymer, maleic anhydride-modified ethylene-octene copolymer as a modified olefin polymer, <B-1> 15 parts by weight are blended with a Henschel mixer, and bent. Extrusion kneading was performed (QE / NS = 5 kg / 50 rpm) with a twin screw extruder (PCM30, L / D = 32). The extruded resin was pelletized with a strand cutter and dried at 80 ° C. for 3 hours. This pellet was molded into a desired shape using an injection molding machine, and physical properties were evaluated and the dispersed particle size was measured including molding appearance and weld characteristics. The results are shown in Table 3. Granulation and molding can be performed in the same manner as ordinary polyoxymethylene resin, and foaming and the like were not observed.

[Examples 2 to 5]
Under the conditions shown in Table 3 or 4, a polyoxymethylene copolymer and a modified olefin polymer were blended and blended with a Henschel mixer. Thereafter, the same operation and evaluation as in Example 1 were performed. The results are shown in Table 3 or 4. Granulation and molding can be performed in the same manner as ordinary polyoxymethylene resin, and foaming and the like were not observed.

[Example 6]
Under the conditions shown in Table 4, polyoxymethylene copolymer <A-1>, polyoxymethylene resin <A-5>, and modified olefin polymer <B-1> were blended at the same time and blended with a Henschel mixer. Thereafter, the same operation and evaluation as in Example 1 were performed. The results are shown in Table 4. Granulation and molding can be performed in the same manner as ordinary polyoxymethylene resin, and foaming and the like were not observed.

[Example 7]
70 parts by weight of polyoxymethylene copolymer <A-1> and 25 parts by weight of modified olefin polymer <B-1> were blended at the same time, blended with a Henschel mixer, and a twin screw extruder with a vent (PCM30, L / D = 32), and extrusion kneading was performed (QE / NS = 5 kg / 50 rpm). Thereafter, the pellets and the oxymethylene resin <A-5> were again extruded and kneaded at 95:30 under the same conditions. The pellets thus obtained were evaluated in the same manner as in Example 1. The results are shown in Table 4. Granulation and molding could be carried out without any problems, and no foaming was observed. By mixing <A-5> later, the weld elongation was further improved as compared with the method of granulating at once.

[Examples 8 to 10]
Under the conditions shown in Table 4 or 5, the polyoxymethylene copolymer and the modified olefin polymer were blended and blended with a Henschel mixer. Thereafter, the same operation and evaluation as in Example 1 were performed. The results are shown in Table 4 or 5. Granulation and molding can be performed in the same manner as ordinary polyoxymethylene resin, and foaming and the like were not observed.

[Example 11]
Under the conditions shown in Table 5, the polyoxymethylene copolymer <A-1> and the modified olefin polymers <B-1> and <B-7> were simultaneously blended and blended with a Henschel mixer. Thereafter, the same operation and evaluation as in Example 1 were performed. The results are shown in Table 5. Granulation and molding can be performed in the same manner as ordinary polyoxymethylene resin, and foaming and the like were not observed.

[Example 12]
Under the conditions shown in Table 5, polyoxymethylene copolymer <A-1>, modified olefin polymer <B-3>, and silicon oil (Toray Dow Corning / SH100-100CS) as a lubricant were blended simultaneously, Henschel Blended with a mixer. Thereafter, the same operation and evaluation as in Example 1 were performed. The results are shown in Table 5. Granulation and molding can be performed in the same manner as ordinary polyoxymethylene resin, and foaming and the like were not observed. By adding silicone oil, the dispersed particles became smaller and the weld elongation was further improved.

[Comparative Example 1]
Evaluation similar to Example 1 was implemented about the polyoxymethylene copolymer <A-1> which has not added the modified olefin type polymer. The results are shown in Table 3. The rigidity was excellent, but the toughness was low.

[Comparative Example 2]
Evaluation was carried out by operating in the same manner as in Example 1 under the conditions shown in Table 3. The results are shown in Table 3. Although the toughness was improved by adding 75 parts, the rigidity inherent to the oxymethylene resin was lowered, and the balance as a resin was poor.

[Comparative Example 3]
The same operation as in Example 1 was performed under the conditions shown in Table 4. When a normal oxymethylene resin that was not modified was blended, the end concentration of the hydroxyalkyl group was insufficient, resulting in a strand of foam during granulation, which was inferior to a normal polyoxymethylene resin in visual appearance evaluation.

[Comparative Example 4]
The same operation as in Example 1 was performed under the conditions shown in Table 5. The raw material after blending with a Henschel mixer was put into the hopper of the extruder, but the raw material did not fall from the hopper during granulation, and a sample with quantitativeness could not be obtained. When the Mooney viscosity is low, the handleability is inferior.

[Comparative Example 5]
The operation was performed in the same manner as in Example 1 under the conditions shown in Table 5, and evaluation was performed. The results are shown in Table 5.
When the modified olefin polymer <B-5> having a high Mooney viscosity was blended, sufficient weld elongation could not be obtained.

[Comparative Example 6]
The same operation as in Example 1 was performed under the conditions shown in Table 6. When the modified olefin polymer <B-6> having a modifying group of 15% by weight was blended, the odor during granulation was remarkable, the strands were foamed, and pellets were not obtained.

[Comparative Example 7]
The operation was performed in the same manner as in Example 1 under the conditions shown in Table 5, and evaluation was performed. The results are shown in Table 5. When a modified olefin polymer having no modifying group was blended, sufficient weld elongation could not be obtained due to poor affinity.

  The present invention is a composition that retains the thermal stability and rigidity of the polyoxymethylene resin and has excellent impact resistance without impairing the molding appearance. When the composition of the present invention is used, It is suitable for parts in office automation equipment, automobiles, industrial materials and general merchandise.

Claims (8)

Including 100 parts by weight of polyoxymethylene resin (A), 5 to 60 parts by weight of modified olefin polymer (B) and 0 to 10 parts by weight of lubricant (C), component (A) has a hydroxyalkyl group at the molecular end. And a polyoxymethylene copolymer (a-1) of 100 to 50% by weight and an oxymethylene resin (a-2) 0 having a hydroxyalkyl group terminal concentration of 5 × 10 ⁻⁵ mol or more per mol of oxymethylene units. -50% by weight, the component (B) contains 20% by weight or more of an olefin polymer having a modified group of 0.01-8% by weight, and its Mooney viscosity is 5-60 ML _{1 + 4} 100 ° C. A polyoxymethylene resin composition. The polyoxymethylene copolymer (a-1) was stabilized by treating a thermally unstable terminal with at least one quaternary ammonium compound represented by the following [Formula 1]. The polyoxymethylene resin composition according to claim 1.

(In the formula, R ₁ , R ₂ , R ₃ , and R ₄ each independently represent an unsubstituted alkyl group or substituted alkyl group having 1 to 30 carbon atoms, an aryl group having 6 to 20 carbon atoms, or 1 to 1 carbon atoms. An aralkyl group in which 30 unsubstituted alkyl groups or substituted alkyl groups are substituted with at least one aryl group having 6 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms has at least one carbon atom having 1 to 30 carbon atoms Represents an unsubstituted alkyl group or an alkylaryl group substituted with a substituted alkyl group, and the unsubstituted alkyl group or substituted alkyl group is linear, branched, or cyclic, the above-mentioned unsubstituted alkyl group, aryl group, aralkyl group; In the alkylaryl group, a hydrogen atom may be substituted with a halogen, n represents an integer of 1 to 3. X is a hydroxyl group, or a carboxylic acid having 1 to 20 carbon atoms, a hydrogen acid, an oxo acid inorganic thioacid. Or, it represents an acid residue of an organic thioacid having 1 to 20 carbon atoms.) The polyoxymethylene copolymer (a-1) causes at least one hydroxyl group, carboxyl group, amino group, ester group, or alkoxy group to chain transfer a polymer having a number average molecular weight of 400 or more. 3. The polyoxymethylene resin composition according to claim 1, which is a polyoxymethylene block copolymer obtained in the above manner. The polyoxymethylene resin composition according to claim 3, wherein the polyoxymethylene block copolymer is a polyoxymethylene copolymer having a number average molecular weight of 10,000 to 500,000 represented by the following [Formula 2]. .

(In the formula, other than A (referred to as B block) is m = 2 to 98 mol%, n = 2 to 98 mol%, m + n = 100 mol%, and m is present randomly or in blocks with respect to n. hydrogenated liquid polybutadiene residue at both ends was hydroxyalkylated with a number average molecular weight of 500 to 10,000. However, B block may be those having the following unsaturated bond iodine value _20g-I 2 / 100g. k is an integer selected from 2 to 6, and two k's may be the same or different, and R is selected from hydrogen, an alkyl group, a substituted alkyl group, an aryl group, and a substituted aryl group. The A block is a polyoxymethylene copolymer residue represented by the following [Formula 3].

(R ′ is selected from hydrogen, an alkyl group, a substituted alkyl group, an aryl group, and a substituted aryl group, and each may be the same or different. J is an integer selected from 2 to 6. x = 95 to 99.9 mol%, y = 5 to 0.1 mol%, x + y = 100 mol%, y is present randomly with respect to x.) In [Formula 2], the average number average molecular weight of the two A blocks 5,000 to 250,000. ) The modified olefin polymer (B) is dispersed in the polyoxymethylene resin (A), and 60% or more of the dispersed particles have a minor axis diameter of 3 µm or less. The polyoxymethylene resin composition described in 1. The modified olefin polymer (B) contains at least 20% by weight or more of an olefin polymer modified by 0.01 to 8% by weight with a carboxylic acid or an acid anhydride thereof. The polyoxymethylene resin composition according to any one of the above. After substantially mixing the polyoxymethylene copolymer (a-1), the modified olefin polymer (B) and the lubricant (C), it was obtained by mixing the oxymethylene resin (a-2). The polyoxymethylene resin composition according to claim 1, wherein the composition is a polyoxymethylene resin composition. A molded product, wherein the polyoxymethylene resin composition according to any one of claims 1 to 7 is obtained by injection molding, gas injection molding, multilayer injection molding, extrusion molding or blow molding.