JP2012021095A - Polyoxymethylene resin composition and molding - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a polyoxymethylene resin composition having excellent blocking properties (degree of clustering) producible of a molding having excellent oil resistance in addition to excellent impact resistance, damping performance and slidability.SOLUTION: There are provided a polyoxymethylene resin composition including (A) 20-95 pts.mass polyoxymethylene resin, (B) 3-78 pts.mass polymer having at least one vinylaromatic compound-conjugated diene compound copolymer block, and a principal dispersion peak temperature of tan δ of 60°C or lower in the viscoelasticity spectrum, or a hydrogenated product thereof, (C) 1-10 pts.mass oil and (D) 1-10 pts.mass lubricant, where the total amount of the components (A), (B), (C) and (D) is 100 pts.mass. A molding of the polyoxymethylene resin composition is also provided.

Description

  The present invention relates to a polyoxymethylene resin composition and a molded body.

Polyoxymethylene resins are widely used in various mechanical parts, OA equipment, and the like as engineering resins that have balanced mechanical properties and excellent friction and wear performance.
However, conventionally, polyoxymethylene resins do not have a sufficient level of impact resistance, so attempts have been made to prepare them as a composition in combination with an elastomer component.
Specifically, a technique for blending a polyurethane resin with a polyoxymethylene resin (for example, see Patent Documents 1 and 2), a technique for blending an olefin-based elastomer and polyurethane with a polyoxymethylene resin (for example, see Patent Document 3). ), A technique for blending a polyacetal resin with a multilayer interpolymer and a thermoplastic polyurethane (for example, see Patent Document 4), a technique for blending a thermoplastic polyurethane and a polyether block copolyamide with polyoxymethylene (for example, a patent) Reference 5) is known.
Among these techniques, a technique for adding polyurethane to a polyacetal resin has been put into practical use.
However, these conventionally proposed compositions are not practically sufficient from the viewpoint of vibration damping performance, and are also inferior in sliding performance, so they are suitable for applications intended for vibration damping and noise reduction. Have the problem of not.

As a material that may be developed for applications intended for vibration suppression, a composition comprising a resin composed of a thermoplastic polyurethane block, a block of a conjugated diene compound unit and an aromatic vinyl compound unit and a polyacetal resin (for example, a patent) Reference 6) is known.
However, although this composition has excellent vibration damping performance, it has a problem that a sufficient silencing effect cannot be obtained due to poor sliding performance.

  As a technique for solving the above-mentioned problem concerning the silencing effect, a main dispersion peak of tan δ in a viscoelastic spectrum having at least one polyoxymethylene resin and a hydrogenated aromatic vinyl-conjugated diene random copolymer is 60 ° C. or less. A composition (for example, refer to Patent Document 7) in which a polymer and optionally a polyolefin-based resin are blended at a ratio in a specific range has been proposed.

JP 59-155453 A JP 59-145243 JP 54-155248 A JP-A-62-036451 JP 63-280758 A JP-A-9-310017 International Publication No. 2005/035652

  However, although the composition proposed in Patent Document 7 is a composition that solves the problems of the prior art, such as exhibiting excellent vibration damping performance and silencing effect, it has sufficient characteristics for oil resistance. It has not been obtained and there is room for further improvement.

  Therefore, in the present invention, in view of the above-mentioned problems of the prior art, in addition to excellent impact resistance and vibration damping performance, it is possible to produce a molded product imparted with excellent oil resistance and excellent blocking properties. Another object of the present invention is to provide a polyoxymethylene resin composition and a molded article having the above characteristics.

In order to impart excellent oil resistance to the polyoxymethylene resin composition in addition to excellent impact resistance and vibration damping performance, the present inventors have examined various polymer compounds. A polyoxymethylene resin composition containing a polymer having at least one predetermined vinyl aromatic compound-conjugated diene compound copolymer block or a hydrogenated product thereof, an oil, and a lubricant in a predetermined ratio is described above. It has been found that the problems can be solved, and the present invention has been completed.
That is, the present invention is as follows.

[1]
(A) Polyoxymethylene resin: 20 to 95 parts by mass;
(B) A polymer having at least one vinyl aromatic compound-conjugated diene compound copolymer block and a tan δ main dispersion peak temperature in a viscoelastic spectrum of 60 ° C. or lower, or a hydrogenated product thereof: 3 to 78 Part by mass;
(C) Oil: 1 to 10 parts by mass,
(D) Lubricant: 1 to 10 parts by mass,
The polyoxymethylene resin composition in which the total amount of the component (A), the component (B), the component (C), and the component (D) is 100 parts by mass.

[2]
Said (A) component contains the polyoxymethylene block copolymer (A-1) of the number average molecular weight 10000-500000 represented by following General formula (1), The polyoxymethylene resin as described in said [1] Composition.
HR ³ —O— (CR ¹ ₂ ) _k —R ⁴ — (CR ¹ ₂ ) _k —O—R ³ —H (1)
(In General Formula (1), each R ¹ independently represents a chemical species selected from the group consisting of a hydrogen atom, a substituted or unsubstituted alkyl group, and a substituted or unsubstituted aryl group, and is the same as each other. It may or may not be.
k shows the integer of 2-6 each independently.
R ³ represents a block having a plurality of oxymethylene units represented by the following general formula (2a) and oxyhydrocarbon units represented by the following general formula (2b), wherein the oxymethylene unit and the oxyhydrocarbon unit Are present at random, and the total amount of the oxymethylene unit and the oxyhydrocarbon unit is 100 mol%, the content of the oxymethylene unit is 95-99.9 mol%, Content is 0.1-5 mol%, and the average of the number average molecular weight of two R < ³ > is 5000-250,000.
In the following general formula (2b), each R ² independently represents a chemical species selected from the group consisting of a hydrogen atom, a substituted or unsubstituted alkyl group, and a substituted or unsubstituted aryl group, and is the same as each other. It may be present or different, and j represents an integer of 2 to 6.
R ⁴ represents a block having a plurality of ethylene units represented by the following general formula (3a) and n-butylene units represented by the following general formula (3b), and the ethylene unit and the n-butylene unit are: Relative to each other or in blocks, the ethylene unit content is 2 to 98 mol% and the n-butylene unit content is 2 with respect to 100 mol% of the total amount of the ethylene unit and the n-butylene unit. It is -98 mol%, A number average molecular weight is 500-10000, You may have an unsaturated bond of iodine number 20g-I < ₂ > / 100g or less. )
— (CH ₂ O) — (2a)
-((CR ² ₂ ) _j -O)-(2b)
_{- (CH 2 CH 2) -} ··· (3a)
_{- (CH 2 CH 2 CH 2} CH 2) - ··· (3b)

[3]
The component (A) has an oxymethylene unit and an oxyalkylene unit having 2 or more carbon atoms as the component (A-2) different from the component (A-1), and the oxymethylene unit and the oxyalkylene. A polyoxymethylene copolymer having a content of the oxyalkylene unit of 0.1 to 10 mol% based on the total amount of the unit,
The polyoxy according to [2], wherein the mass ratio (A-1) / (A-2) of the component (A-1) to the component (A-2) is 99/1 to 10/90. Methylene resin composition.

[4]
The polyoxymethylene resin composition according to [2], wherein the component (A) is the component (A-1).

[5]
The polyoxymethylene resin composition according to any one of [1] to [4], wherein a main dispersion peak temperature of the tan δ in the viscoelastic spectrum of the component (B) is in the range of 60 ° C to -20 ° C. object.

[6]
The component (D) is a silicone-grafted polyolefin resin, alcohol, fatty acid, ester of alcohol and fatty acid, ester of alcohol and dicarboxylic acid, polyoxyalkylene glycol, and olefin compound having an average degree of polymerization of 10 to 500 The polyoxymethylene resin composition according to any one of [1] to [5], which is at least one resin selected from the group consisting of:

[7]
The molded object shape | molded using the polyoxymethylene resin composition as described in any one of said [1] thru | or [6].

  According to the present invention, there is provided a polyoxymethylene resin composition capable of producing a molded article having excellent oil resistance in addition to excellent impact resistance, vibration damping performance and slidability, and also having excellent blocking properties. A molded body having the above characteristics is obtained.

Hereinafter, a mode for carrying out the present invention (hereinafter referred to as “the present embodiment”) will be described.
The present invention is not limited to the following description, and various modifications can be made within the scope of the gist thereof.

[Polyoxymethylene resin composition]
The polyoxymethylene resin composition of the present embodiment (hereinafter also simply referred to as “resin composition”) contains the following (A) to (D).
(A): polyoxymethylene resin (B): a polymer having at least one vinyl aromatic compound-conjugated diene compound copolymer block and a main dispersion peak of tan δ in a viscoelastic spectrum of 60 ° C. or lower The hydrogenated product (C): Oil (D): Lubricant These are also simply referred to as “components (A) to (D)” in the present specification.

((A) polyoxymethylene resin)
Examples of the (A) polyoxymethylene resin contained in the polyoxymethylene resin composition of the present embodiment include polyoxymethylene homopolymers and polyoxymethylene copolymers.
A polyoxymethylene homopolymer is obtained by homopolymerizing a formaldehyde monomer or a cyclic oligomer of formaldehyde such as a trimer (trioxane) or tetramer (tetraoxane). Therefore, the polyoxymethylene homopolymer substantially consists of oxymethylene units.
On the other hand, the polyoxymethylene copolymer is a formaldehyde monomer or a cyclic oligomer of formaldehyde such as a trimer (trioxane) or tetramer (tetraoxane), ethylene oxide, propylene oxide, epichlorohydrin, 1,3- It is obtained by copolymerizing glycol such as dioxolane and 1,4-butanediol formal, cyclic ether such as cyclic formal of diglycol, and cyclic formal.
The polyoxymethylene copolymers include branched polyoxymethylene copolymers obtained by copolymerizing formaldehyde monomers and / or cyclic oligomers of formaldehyde with monofunctional glycidyl ethers, and formaldehyde A polyoxymethylene copolymer having a cross-linked structure obtained by copolymerizing a monomer and / or a cyclic oligomer of formaldehyde and a polyfunctional glycidyl ether can also be used.

Furthermore, (A) polyoxymethylene resin is obtained by polymerizing a formaldehyde monomer or a formaldehyde cyclic oligomer in the presence of a compound having a functional group such as a hydroxyl group at both ends or one end, such as polyalkylene glycol. It may be a polyoxymethylene homopolymer having a block component to be obtained.
Similarly, (A) polyoxymethylene resin is a formaldehyde monomer or its trimer (trioxane) in the presence of a compound having a functional group such as a hydroxyl group at both ends or one end, such as hydrogenated polybutadiene glycol. And a polyoxymethylene copolymer having a block component obtained by copolymerizing a cyclic oligomer of formaldehyde such as tetramer and tetraether or cyclic formal.
As mentioned above, both (A) polyoxymethylene resin which comprises the polyoxymethylene resin composition of this embodiment can use a polyoxymethylene homopolymer and a polyoxymethylene copolymer.
(A) It is preferable that polyoxymethylene resin contains a polyoxymethylene copolymer especially.

<Method for producing polyoxymethylene copolymer>
An example of a polyoxymethylene copolymer is a copolymer of formaldehyde trimer (trioxane) and 1,3-dioxolane.
When obtaining this polyoxymethylene copolymer, the comonomer such as 1,3-dioxolane is generally 0.1 to 60 mol, preferably 0.1 to 20 mol, more preferably 0, relative to 100 mol of trioxane. Use 13 to 10 mol.
The melting point of the polyoxymethylene copolymer is preferably 162 ° C to 173 ° C, more preferably 167 ° C to 173 ° C, and further preferably 167 ° C to 171 ° C. A polyoxymethylene copolymer having a melting point of 167 ° C. to 171 ° C. can be obtained by using a comonomer of about 1.3 to 3.5 mol with respect to 100 mol of trioxane.
Regarding the melting point of the polyoxymethylene copolymer, first, as a pretreatment, the crude polyoxymethylene copolymer obtained from the polymerization machine was formed into a film with a compression press set at 190 ° C., and 5 mg of the film was cut out. Next, the temperature was increased from room temperature to 200 ° C. at 40 ° C./min, held at 200 ° C. for 1 minute, and held at 130 ° C. at 40 ° C./min using Perkin Elmer (DSC-7). After the temperature was lowered, the peak top of the endothermic curve when the temperature was raised to 200 ° C. at 2.5 ° C./min was measured, and this was taken as the melting point.

In the polymerization step of the polyoxymethylene copolymer, it is preferable to use a predetermined polymerization catalyst.
As a polymerization catalyst used for the polymerization of the polyoxymethylene copolymer, for example, a cationically active catalyst such as a Lewis acid, a protonic acid and an ester or an anhydride thereof is preferable.
Examples of Lewis acids include boric acid, tin, titanium, phosphorus, arsenic and antimony halides. More specifically, boron trifluoride, tin tetrachloride, titanium tetrachloride, phosphorus pentafluoride, Examples thereof include phosphorus pentachloride, antimony pentafluoride, and complex compounds or salts thereof.
Examples of the protonic acid, ester or anhydride thereof include perchloric acid, trifluoromethanesulfonic acid, perchloric acid-tertiary butyl ester, acetyl perchlorate, and trimethyloxonium hexafluorophosphate.
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, trifluoride is used. Boron diethyl ether and boron trifluoride di-n-butyl ether are preferred.

As a polymerization method for producing the polyoxymethylene copolymer, conventionally known methods can be applied.
For example, U.S. Pat. Nos. 3,027,352, 3,803,094, German Patents 1,161,421, 1,495,228, 1,720,358, 3,018,898, JP Polymerization can be carried out by the methods described in JP-A-58-98322 and JP-A-7-70267.

Since the polyoxymethylene copolymer obtained by the above polymerization has a thermally unstable terminal portion [-(OCH ₂ ) _n —OH group], it is difficult to put it into practical use as it is. . Therefore, it is preferable to perform the decomposition and removal treatment of the unstable terminal portion, and specifically, it is preferable to perform the decomposition and removal processing of the specific unstable terminal portion described below.
That is, in the presence of at least one quaternary ammonium compound represented by the following general formula (4), the polyoxymethylene copolymer is reacted at a temperature not lower than the melting point of the polyoxymethylene copolymer and not higher than 260 ° C. There is a method in which a specific unstable terminal portion is decomposed and removed by performing a heat treatment in a melted state.

[R ⁵ R ⁶ R ⁷ R ⁸ N ⁺ ] _n X ⁻ⁿ (4)
In general formula (4), R ⁵ , R ⁶ , R ⁷ and R ⁸ are each independently a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms; an aryl group having 6 to 20 carbon atoms; An aralkyl group in which at least one hydrogen atom in a substituted or unsubstituted alkyl group having 1 to 30 is substituted with an aryl group having 6 to 20 carbon atoms; or at least one hydrogen in an aryl group having 6 to 20 carbon atoms An alkylaryl group in which an atom is substituted with a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms is represented, and the substituted or unsubstituted alkyl group is linear, branched, or cyclic.
The substituent in the substituted alkyl group is a halogen atom, a hydroxyl group, an aldehyde group, a carboxyl group, an amino group, or an amide group.
In the unsubstituted alkyl group, aryl group, aralkyl group, and alkylaryl group, a hydrogen atom may be substituted with a halogen atom.
n shows the integer of 1-3.
X represents a hydroxyl group or an acid residue of a carboxylic acid having 1 to 20 carbon atoms, a hydrogen acid other than a hydrogen halide, an oxo acid, an inorganic thioacid, or an organic thioacid having 1 to 20 carbon atoms.

The quaternary ammonium compound used for decomposing and removing the thermally unstable terminal portion [— (OCH ₂ ) _n —OH group] of the polyoxymethylene copolymer is represented by the general formula (4). In general formula (4), R ⁵ , R ⁶ , R ⁷ , and R ⁸ are each independently an alkyl group having 1 to 5 carbon atoms or a carbon number. It is preferably 2 to 4 hydroxyalkyl groups, and more preferably at least one of R ⁵ , R ⁶ , R ⁷ and R ⁸ is a hydroxyethyl group.
Specific examples of the quaternary ammonium compound include tetramethylammonium, tetoethylammonium, 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-hydroxyethyl) ammonium , Tri-n-butyl (2-hydroxyethyl) ammonium, trimethylbenzylammonium, triethylbenzylammonium, tripropylbenzylan Nium, tri-n-butylbenzylammonium, trimethylphenylammonium, triethylphenylammonium, trimethyl-2-oxyethylammonium, monomethyltrihydroxyethylammonium, monoethyltrihydroxyethylammonium, okdadecyltri (2-hydroxyethyl) ammonium, Hydroxides such as tetrakis (hydroxyethyl) ammonium; Hydrochloric acid salts such as hydrochloric acid, odorous acid and hydrofluoric acid; sulfuric acid, nitric acid, phosphoric acid, carbonic acid, boric acid, chloric acid, iodic acid, silicic acid, perchloric acid, nitrous acid Oxo acid salts such as chloric acid, hypochlorous acid, chlorosulfuric acid, 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, capron Acid, caprylic acid, capric acid, benzoic acid, Shu They include carboxylic acid salts such as. Among these, hydroxide (OH ⁻ ), sulfuric acid (HSO ₄ ⁻ , SO ₄ ²⁻ ), carbonic acid (HCO ₃ ⁻ , CO ₃ ²⁻ ), boric acid (B (OH) ₄ ⁻ ), and carboxylic acid The salt of is preferred.
Among the carboxylic acids, formic acid, acetic acid, and propionic acid are particularly preferable.
A quaternary ammonium compound may be used individually by 1 type, and may be used in combination of 2 or more type.
Further, in addition to the quaternary ammonium compound, amines such as ammonia and triethylamine, which are known decomposition accelerators for unstable terminals, may be used in combination.

The amount of the quaternary ammonium compound used for decomposing and removing the thermally unstable terminal portion [— (OCH ₂ ) _n —OH group] of the polyoxymethylene copolymer is as follows. In terms of the amount of nitrogen derived from the quaternary ammonium compound represented by the following formula (5) with respect to the total mass of the copolymer and the quaternary ammonium compound, preferably 0.05 to 50 ppm by mass, more preferably 1 to 30 ppm by mass.
Amount of quaternary ammonium compound used = P × 14 / Q (5)
Here, in the above formula (5), P represents the concentration (mass ppm) of the quaternary ammonium compound relative to the polyoxymethylene copolymer, 14 is the atomic weight of nitrogen, and Q is the molecular weight of the quaternary ammonium compound. Indicates.

The amount of the quaternary ammonium compound used to decompose and remove the thermally unstable terminal portion [— (OCH ₂ ) _n —OH group] of the polyoxymethylene copolymer is 0.05. When it is in the range of ˜50 mass ppm, a practically sufficient decomposition / removal rate of the unstable terminal portion can be secured, and the color tone of the polyoxymethylene copolymer obtained after decomposition / removal becomes good.

As described above, the thermally unstable terminal portion [— (OCH ₂ ) _n —OH group] of the (A) polyoxymethylene resin is (A) the polyoxymethylene resin at a temperature of the melting point to 260 ° C. When it is heat-treated in a molten state, it is decomposed and removed.
The apparatus used for the decomposition and removal treatment is not particularly limited, but an extruder, a kneader and the like are preferable.
Formaldehyde is generated by decomposition, but is usually removed under reduced pressure.
There is no particular limitation on the method for allowing the quaternary ammonium compound to be present in the polyoxymethylene copolymer when the thermally unstable terminal portion is decomposed and removed, for example, a step of deactivating the polymerization catalyst. And a method of spraying on a polyoxymethylene copolymer powder produced by polymerization.
Whichever method is used, the quaternary ammonium compound may be present in the resin in the step of heat-treating the polyoxymethylene copolymer.
For example, a quaternary ammonium compound may be injected into an extruder in which a polyoxymethylene copolymer is melt-kneaded and extruded. Alternatively, when a filler or pigment is added to the polyoxymethylene copolymer using the extruder or the like, a quaternary ammonium compound is first attached to the resin pellet of the polyoxymethylene copolymer, and then the filler or pigment is added. The unstable end portion may be decomposed and removed at the time of blending.

  (A) The thermally unstable terminal portion of the polyoxymethylene resin can be decomposed and removed after the polymerization catalyst coexisting with the polyoxymethylene copolymer obtained by polymerization is deactivated. It is also possible to carry out without deactivating the polymerization catalyst.

Examples of the deactivation treatment of the polymerization catalyst include a method of neutralizing and deactivating the polymerization catalyst in a basic aqueous solution such as amines.
When the polymerization catalyst is not deactivated, the copolymer is heated under an inert gas atmosphere at a temperature below the melting point of the polyoxymethylene copolymer, and the polymerization catalyst is reduced by volatilization, and then the unstable terminal. It is also an effective method to perform the disassembly and removal operation of the part.

  By decomposing and removing the unstable terminal portion as described above, (A) to obtain a polyoxymethylene copolymer suitable as a polyoxymethylene resin having very excellent unstable thermal stability and almost no unstable terminal portion. Can do.

In this embodiment, (A) polyoxymethylene resin is (A-1) described later: a polyoxymethylene block copolymer having a number average molecular weight of 10,000 to 500,000 represented by the following general formula (1) (hereinafter, “ (A-1) is also referred to as a component ".
Furthermore, (A) the polyoxymethylene resin is different from the above (A-1) (A-2): having an oxymethylene unit and an oxyalkylene unit having 2 or more carbon atoms, the oxymethylene unit and the oxyalkylene A polyoxymethylene copolymer containing 0.1 to 10 mol%, preferably 0.1 to 5 mol%, more preferably 0.2 to 3 mol% of oxyalkylene units based on the total amount of units. It is preferable.
This (A-1) polyoxymethylene block copolymer can be produced by the method described in WO 01/009213.
The number average molecular weight is a molecular weight in terms of PMMA (polymethyl methacrylate) as determined by gel permeation chromatography.

HR ³ —O— (CR ¹ ₂ ) _k —R ⁴ — (CR ¹ ₂ ) _k —O—R ³ —H (1)

Here, in the general formula (1), each R ¹ independently represents any chemical species selected from the group consisting of a hydrogen atom, a substituted or unsubstituted alkyl group, and a substituted or unsubstituted aryl group. These may be the same or different.
k shows the integer of 2-6 each independently.
R ³ represents a block having a plurality of oxymethylene units represented by the following general formula (2a) and oxyhydrocarbon units represented by the following general formula (2b). What are oxymethylene units and oxyhydrocarbon units? Relative to each other, the total amount of oxymethylene units and oxyhydrocarbon units is 100 mol%, the content of oxymethylene units is 95 to 99.9 mol%, and the content of oxyhydrocarbon units is 0.1. a 5 mole%, a number average molecular weight of the average of the two R ³ is from 5,000 to 250,000.
In the formula (2b), R ² each independently represents any chemical species selected from the group consisting of a hydrogen atom, a substituted or unsubstituted alkyl group, and a substituted or unsubstituted aryl group, and is the same as each other Or different.
j represents an integer of 2 to 6.
The hydrogen atoms at both ends in the general formula (1) are bonded to oxygen atoms in the following general formula (2a) or (2b).
R ⁴ represents a block having a plurality of ethylene units represented by the following general formula (3a) and n-butylene units represented by the following general formula (3b), and the ethylene units and n-butylene units are random or The ethylene unit content is 2 to 98 mol% and the n-butylene unit content is 2 to 98 mol% with respect to 100 mol% of the total amount of ethylene units and n-butylene units. Further, R ⁴ has a number average molecular weight thereof is 500 to 10,000, may have the following unsaturated bond iodine value 20g-I ₂ / 100g.

— (CH ₂ O) — (2a)
-((CR ² ₂ ) _j -O)-(2b)
_{- (CH 2 CH 2) -} ··· (3a)
_{- (CH 2 CH 2 CH 2} CH 2) - ··· (3b)

  Examples of the substituent in the substituted alkyl group and the substituted aryl group include a halogen atom, a hydroxyl group, an aldehyde group, a carboxyl group, an amino group, and an amide group.

The component (A-1) is effective for improving compatibility with a polymer containing an olefin component, and in this respect, the component (A-1) is particularly preferably used alone.
Moreover, when using (A-1) component together with (A-2) component, those mass ratios (A-1) / (A-2) are preferable in the range of 99/1 to 10/90. The range of 95/5 to 20/80 is more preferable, and the range of 95/5 to 70/30 is more preferable.

<(A) Physical properties of polyoxymethylene resin>
(A) The melt flow rate of the polyoxymethylene resin (measured under the conditions of ASTM-D1238-57T) is preferably 0.5 g / 10 min or more from the surface of molding, and 100 g / 10 min from the surface of durability. The range is preferably 1.0 to 80 g / 10 minutes, more preferably 5 to 60 g / 10 minutes, and still more preferably 7 to 50 g / 10 minutes.

<(A) Other components contained in polyoxymethylene resin>
In the polyoxymethylene resin (A) used in the present embodiment, one type of stabilizer used in conventional polyoxymethylene resins, for example, one type of thermal stabilizer is used alone or in combination of two or more types.
As the heat stabilizer, antioxidants, formaldehyde and formic acid scavengers, and combinations thereof are suitable.

As the antioxidant, a hindered phenol-based antioxidant is preferable.
Examples of the hindered phenol antioxidant include n-octadecyl-3- (3 ′, 5′-di-t-butyl-4′-hydroxyphenyl) -propionate, n-octadecyl-3- (3′- Methyl-5′-t-butyl-4′-hydroxyphenyl) -propionate, n-tetradecyl-3- (3 ′, 5′-di-t-butyl-4′-hydroxyphenyl) -propionate, 1,6- Hexanediol-bis- (3- (3,5-di-t-butyl-4-hydroxyphenyl) -propionate), 1,4-butanediol-bis- (3- (3,5-di-t-butyl) -4-hydroxyphenyl) -propionate), triethylene glycol-bis- (3- (3-tert-butyl-5-methyl-4-hydroxyphenyl) -propionate).

  Examples of hindered phenol antioxidants include tetrakis- (methylene-3- (3 ′, 5′-di-t-butyl-4′-hydroxyphenyl) propionate methane, 3,9-bis ( 2- (3- (3-tert-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) prepionylhexamethylenediamine, N, N′-tetramethylenebis-3- (3′- Methyl-5′-t-butyl-4-hydroxyphenol) propionyldiamine, N, N′-bis- (3- (3,5-di-t-butyl-4-hydroxyphenol) propionyl) hydra N-salicyloyl-N′-salicylidenehydrazine, 3- (N-salicyloyl) amino-1,2,4-triazole, N, N′-bis (2- (3- (3,5-di- Mention may also be made of butyl-4-hydroxyphenyl) propionyloxy) ethyl) oxyamide.

  Among the hindered phenol antioxidants described above, 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 the formaldehyde and formic acid scavengers include compounds and polymers containing formaldehyde-reactive nitrogen, alkali metal or alkaline earth metal hydroxides, inorganic acid salts, and carboxylate salts. Examples of compounds and polymers containing formaldehyde-reactive nitrogen include dicyandiamide, melamine, co-condensates of melamine and formaldehyde, nylon 4-6, nylon 6, nylon 6-6, nylon 6-10, nylon 6-12. , Nylon 12, nylon 6 / 6-6, nylon 6 / 6-6 / 6-10, nylon 6 / 6-12 and other polyamide resins, poly-β-alanine, and polyacrylamide. Among these, a co-condensate of melamine and formaldehyde, polyamide resin, poly-β-alanine and polyacrylamide are preferable, and polyamide resin and poly-β-alanine are more preferable.

Examples of the alkali metal or alkaline earth metal hydroxide, inorganic acid salt, and carboxylate include hydroxides such as sodium, potassium, magnesium, calcium or barium, carbonates and phosphates of the above metals. Silicates, borates and carboxylates.
Specifically, calcium salts are preferable, and examples include calcium hydroxide, calcium carbonate, calcium phosphate, calcium silicate, calcium borate, and fatty acid calcium salts (calcium stearate, calcium myristate, etc.), and these fatty acids are substituted with hydroxyl groups. It may be. Among these, fatty acid calcium salts (calcium stearate, calcium myristate, etc.) are more preferable.

Preferred combinations of the stabilizers are in particular triethylene glycol-bis- (3- (3-tert-butyl-5-methyl-4-hydroxyphenyl) -propionate) or tetrakis- (methylene-3- (3 ′, 5 Heavy weight containing hindered phenolic antioxidants typified by '-di-t-butyl-4'-hydroxyphenyl) propionate) methane and formaldehyde reactive nitrogen typified by polyamide resin and poly-β-alanine in particular. It is a combination of a coalescence and a fatty acid salt of an alkaline earth metal typified by a fatty acid calcium salt.
The amount of each stabilizer added is 0.1 to 2 parts by mass of a hindered phenol antioxidant and 0.1% of a polymer containing formaldehyde-reactive nitrogen with respect to 100 parts by mass of (A) polyoxymethylene resin. It is preferable that 1-3 mass parts and the fatty-acid salt of alkaline-earth metal are the range of 0.1-1 mass%.

<Content of (A) polyoxymethylene resin>
The content (mixing ratio) of the component (A) in the polyoxymethylene resin composition of the present embodiment is the component (A), the component (B) described later, the component (C) described later, and the component (D) described later. ) The component is 20 to 95 parts by mass, more preferably 25 to 90 parts by mass, and even more preferably 30 to 80 parts by mass with respect to 100 parts by mass as a total.
When the component (A) is 20 parts by mass or more, the fluidity during molding and the appearance of the molded product are good, and excellent vibration damping performance is imparted at 99.5 parts by mass or less.

((B) Polymer having at least one vinyl aromatic compound-conjugated diene compound copolymer block or hydrogenated product thereof)
The polyoxymethylene resin composition of this embodiment contains (B) component.
The component (B) may be a polymer having at least one vinyl aromatic compound-conjugated diene compound copolymer block and a tan δ main dispersion peak temperature in a viscoelastic spectrum of 60 ° C. or lower, or a hydrogenated product thereof. Any polymer may be used.

By adding the component (B) to the polyoxymethylene resin composition of the present embodiment, there is an effect in improving impact resistance and vibration damping performance.
Specific examples of the component (B) include: (1) at least one polymer block X mainly composed of a vinyl aromatic compound and at least one vinyl aromatic compound-conjugated diene compound copolymer block Y. A block copolymer comprising (2) at least one polymer block Z mainly composed of a conjugated diene compound and at least one vinyl aromatic compound-conjugated diene compound copolymer block Y (3) At least one polymer block X mainly composed of a vinyl aromatic compound, and at least one polymer composed mainly of at least one vinyl aromatic compound-conjugated diene compound copolymer block Y and a conjugated diene compound. A block copolymer comprising a polymer block Z of (4), a vinyl aromatic compound-conjugated diene compound random copolymer, and Luo hydrogenated products, and the like.
Here, the content of the vinyl aromatic compound in the polymer block X mainly composed of the vinyl aromatic compound is preferably 90% by mass or more, and the vinyl aromatic compound in the vinyl aromatic compound-conjugated diene compound copolymer block Y is used. The content of the group compound is preferably 3% by mass or more and less than 90% by mass, and the content of the conjugated diene compound in the polymer block Z mainly composed of the conjugated diene compound is preferably 97% by mass or more.

Among these, (1) a block copolymer comprising at least one polymer block X mainly composed of a vinyl aromatic compound and at least one vinyl aromatic compound-conjugated diene compound copolymer block Y; (2) a block copolymer comprising at least one polymer block Z mainly composed of a conjugated diene compound and at least one vinyl aromatic compound-conjugated diene compound copolymer block Y; (3) vinyl aroma At least one polymer block X mainly composed of an aromatic compound, at least one vinyl aromatic compound-conjugated diene compound copolymer block Y and at least one polymer block Z mainly composed of a conjugated diene compound; Of these, block copolymers consisting of these and hydrogenated products thereof are preferred.
The copolymer block in the block copolymer may be a random copolymer block, and the vinyl aromatic compound in the copolymer block may be uniformly distributed or tapered, that is, a copolymer. You may distribute so that the content may increase as it goes to the other from one side of a polymer block chain.
Further, in the copolymer block, a plurality of blocks in which vinyl aromatic compounds are uniformly distributed and / or a plurality of blocks distributed in a tapered shape may coexist.
Further, a plurality of blocks having different vinyl aromatic compound contents may coexist in the copolymer block.

Examples of the block copolymer comprising (1) at least one polymer block X mainly composed of a vinyl aromatic compound and at least one vinyl aromatic compound-conjugated diene compound copolymer block Y include: , Block copolymers having the following structures: (XY) _n , X- (Y-X) _n- Y, Y- (XY) _{n + 1} , [(XY) _k ] _{m + 1-} W, [(XY) _k- X] _{m + 1-} W, [(Y-X) _k ] _{m + 1-} W, [(Y-X) _k- Y] _{m + 1-} W. Is mentioned.
Here, W represents the residue of the coupling agent or the residue of the initiator of the polyfunctional organolithium compound.
n, k, and m are each independently an integer of 1 or more, and are generally 1-5.

Further, as the block copolymer comprising (2) at least one polymer block Z mainly composed of a conjugated diene compound and at least one vinyl aromatic compound-conjugated diene compound copolymer block Y, For example, a block copolymer having the following structure, that is, (ZY) _n , Z- (YZ) _n -Y, Y- (ZY) _{n + 1} , [(ZY) _k ] _{m + 1} −W, [(Z−Y) _k −Z] _{m + 1} −W, [(Y−Z) _k ] _{m + 1} −W, [(Y−Z) _k −Y] _{m + 1} − W is mentioned.
Here, W represents a residue of a coupling agent or a residue of an initiator of a polyfunctional organolithium compound.
n, k, and m are each independently an integer of 1 or more, and are generally 1-5.

Further, (3) at least one polymer block X mainly composed of a vinyl aromatic compound, at least one vinyl aromatic compound-conjugated diene compound copolymer block Y and at least one composed mainly of a conjugated diene compound. Examples of the block copolymer composed of a single polymer block Z include, for example, block copolymers having the following structures, that is, (X—Y—Z) _n , X— (Y—X) _n —Z, Z -(XY) _{n + 1} , [(XYZ) _k ] _{m + 1-} W, [(XYZ) _k- X] _{m + 1-} W, [(YX- Z) _k ] _{m + 1-} W, [(Y-X) _k- Z] _{m + 1-} W.
Here, W represents a residue of a coupling agent or a residue of an initiator of a polyfunctional organolithium compound.
n, k, and m are each independently an integer of 1 or more, and are generally 1-5.

Examples of the vinyl aromatic compound used in the polymer having at least one vinyl aromatic compound-conjugated diene compound copolymer block (B) contained in the polyoxymethylene resin composition of the present embodiment include styrene, α -1 type, or 2 or more types chosen from the group which consists of methylstyrene, vinyltoluene, p-tert-butylstyrene, and diphenylethylene is preferable, and styrene is more preferable.
The content of the vinyl aromatic compound in the polymer having at least one vinyl aromatic compound-conjugated diene compound copolymer block (B) is 3 to 90% by mass based on the total amount of the polymer (B). Is more preferable, 5-88 mass% is more preferable, More preferably, it is 10-86 mass%.
When the content of the vinyl aromatic compound in the polymer having at least one vinyl aromatic compound-conjugated diene compound copolymer block (B) is 50% by mass or less, preferably 40% by mass or less, The polymer exhibits rubber-like elastic properties, and when it exceeds 50% by mass, and preferably exceeds 60% by mass, it exhibits high vibration damping performance.
From the viewpoint of obtaining a polyoxymethylene resin composition that can produce a molded product having excellent oil resistance in addition to excellent impact resistance, vibration damping performance and sliding property, and also has excellent blocking properties. It is preferable that content of an aromatic compound is 50-80 mass%, More preferably, it is the range of 55-75 mass%, More preferably, it is the range of 60-75 mass%.

Examples of the conjugated diene compound in the polymer having at least one vinyl aromatic compound-conjugated diene compound copolymer block (B) contained in the polyoxymethylene resin composition of the present embodiment include butadiene, isoprene, and piperylene. And 1,3-pentadiene.
The microstructure which is a polymerization form of the conjugated diene compound in the polymer having at least one vinyl aromatic compound-conjugated diene compound copolymer block (B) is not particularly limited.
For example, when the conjugated diene compound is butadiene, the amount of 1,2-vinyl bonds is preferably 2 to 2 with respect to the total amount of 1,2-vinyl bonds, 3,4-vinyl bonds and 1,4-vinyl bonds. 85%, more preferably 8 to 85%, still more preferably 10 to 85%.
In the case where the conjugated diene compound is isoprene, the 1,2-vinyl bond and the 3,4-vinyl bond with respect to the total amount of 1,2-vinyl bond, 3,4-vinyl bond and 1,4-vinyl bond. The total amount is preferably 2 to 85%, more preferably 3 to 75%, and still more preferably 3 to 60%.
And the conjugated diene compound polymer which is a precursor (prepolymer) of (B) component, and the number average of the polymer which has at least one vinyl aromatic compound-conjugated diene compound copolymer block which is (B) component The molecular weight (molecular weight in terms of polystyrene by gel permeation chromatography) is preferably 1,000 to 1,000,000, more preferably 10,000 to 800,000, still more preferably 30,000 to 500,000.

The polymer having at least one (B) vinyl aromatic compound-conjugated diene compound copolymer block or the hydrogenated product thereof has a tan δ main dispersion peak temperature of 60 ° C. or less in the viscoelastic spectrum. . When the main dispersion peak temperature is 60 ° C. or less, the molded product of the polyoxymethylene resin composition of the present embodiment has excellent vibration damping / noise reduction performance at room temperature (23 ° C.).
Furthermore, from the viewpoint of improving the vibration damping / noise reduction performance, the main dispersion peak temperature is preferably in the range of 60 ° C to -30 ° C, more preferably in the range of 60 ° C to -20 ° C, and 50 ° C to 0 ° C. More preferably in the range of ° C.

The main dispersion peak temperature of tan δ in the viscoelastic spectrum is measured as follows.
First, a sheet-like sample is cut into a size of 10 mm in width and 35 mm in length, and the sample is set in a twist type geometry of a rheometer device (trade name “ARES”, manufactured by TI Instruments Inc.). .
Next, the effective measurement length is set to 25 mm, the strain is set to 0.5%, the frequency is set to 1 Hz, and the temperature is increased from −80 ° C. to 80 ° C. at a temperature increase rate of 3 ° C./min to obtain a viscoelastic spectrum.
The main dispersion peak temperature of tan δ in the obtained viscoelastic spectrum is obtained from a peak detected by automatic measurement of predetermined software (trade name “RSI Orchestrator”, manufactured by TI Instruments Inc.).

<(B) Production Method of Polymer Having at least One Vinyl Aromatic Compound-Conjugated Diene Compound Copolymer Block>
The polymer having at least one vinyl aromatic compound-conjugated diene compound copolymer block (B) in a hydrocarbon solvent, using an organic lithium compound as a polymerization initiator, a conjugated diene compound and a vinyl aromatic compound, It can manufacture by superposing | polymerizing by anionic polymerization.

  Aliphatic, alicyclic and aromatic hydrocarbons can be used as the hydrocarbon solvent, and specific examples include propane, isobutane, n-hexane, isooctane, cyclopentane, cyclohexane, benzene and toluene. It is done. Among these, preferred solvents are n-hexane, cyclohexane and benzene. A hydrocarbon solvent is used individually by 1 type or in mixture of 2 or more types.

Moreover, as an organic lithium compound which is a polymerization initiator used for polymerization, for example, mono-organic lithium compounds such as n-propyl lithium, isopropyl lithium, n-butyl lithium, sec-butyl lithium and tert-butyl lithium, and And polyfunctional organolithium compounds such as dilithiomethane, 1,4-dilithiobutane, 1,4-dilithio-2-ethylcyclohexane, 1,2-dilithio-1,2-diphenylmethane and 1,3,5-trilithiobenzene. It is done. These can be used individually by 1 type or in mixture of 2 or more types.
The amount of the organolithium compound used as a polymerization initiator depends on the number average molecular weight of the polymer having at least one vinyl aromatic compound-conjugated diene compound copolymer block as a monodisperse polymer (weight average molecular weight / The calculation can be appropriately selected based on the assumption that the number average molecular weight = 1).

In addition, in the polymerization step when producing a polymer having at least one vinyl aromatic compound-conjugated diene compound copolymer block (B), the microstructure 1, 2 is a polymerization mode of the conjugated diene compound. -Ethers and tertiary amines for suppressing the increase in the amount of vinyl bonds and 3,4-vinyl bonds, or for adjusting the randomness in the vinyl aromatic compound-conjugated diene compound copolymer chain Polar compounds such as alkali metal alkoxides can be used.
Examples of such polar compounds include diethyl ether, ethylene glycol dimethyl ether, ethylene glycol di-n-butyl ether, ethylene glycol n-butyl-tert-butyl ether, ethylene glycol di-tert-butyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, Examples include tetrahydrofuran, α-methoxymethyltetrahydrofuran, dioxane, 1,2-dimethoxybenzene, triethylamine, N, N, N ′, N′-tetramethylethylenediamine, potassium tert-amyl oxide, and potassium tert-butyl oxide. These can be used alone or as a mixture of two or more.
The amount used in the case of using such a polar compound may be more than 0 mol, preferably more than 0 mol and 300 mol or less with respect to 1 mol of the organic lithium compound.

Further, a hydrogenation catalyst and hydrogen gas are added to a polymer having at least one vinyl aromatic compound-conjugated diene compound copolymer block produced as described above in a hydrocarbon solvent to form hydrogen. By performing the addition reaction, the olefinically unsaturated bond derived from the conjugated diene compound present in the polymer is 90% or less, preferably 80% or less, more preferably 55% or less, more preferably 20% before hydrogenation. %, A hydrogenated polymer having at least one vinyl aromatic compound-conjugated diene compound copolymer block can be obtained. This hydrogenated product can also be used as the component (B).
The smaller the amount of olefinically unsaturated bonds derived from the conjugated diene compound, the higher the aging resistance and light resistance. If the hydrogenation reaction can reduce the olefinic unsaturated bond derived from the conjugated diene compound present in the polymer having at least one vinyl aromatic compound-conjugated diene compound copolymer block, the production method thereof There is no limitation to this, and any manufacturing method may be used.
Examples of the hydrogenation reaction include, for example, JP-B-42-8704, JP-B-43-6636, JP-A-60-220147, JP-A-61-33132, JP-A-62-207303. Examples thereof include methods described in Japanese Patent Publication No. GB1020720, U.S. Pat. Nos. 3,330,024 and 4,501,857. The hydrogenation rate of the hydrogenated product obtained by these methods can be easily known by infrared spectroscopic analysis, nuclear magnetic resonance analysis or the like.

<(B) Other usage mode of polymer having at least one vinyl aromatic compound-conjugated diene compound copolymer block or hydrogenated product thereof>
(B) A polymer having at least one vinyl aromatic compound-conjugated diene compound copolymer block or a hydrogenated product thereof can also be used as a dynamic crosslinking polymer.

<(B) Content of polymer having at least one vinyl aromatic compound-conjugated diene compound copolymer block or hydrogenated product thereof>
The content (mixing ratio) of the component (B) in the polyoxymethylene resin composition of the present embodiment is the component (A), the component (B), the component (C) described later, and the component (D) described later. 3) to 78 parts by weight, more preferably 10 to 70 parts by weight, and even more preferably 20 to 70 parts by weight with respect to 100 parts by weight as a total of the component.
When the content (mixing ratio) of the component (B) is 78 parts by mass or less, the fluidity during molding and the appearance of the molded product are good, and excellent vibration damping performance is imparted at 3 parts by mass or more.

((C) Oil)
The polyoxymethylene resin composition of this embodiment contains (C) oil.
Component (C): By adding oil, the oil resistance of the polyoxymethylene resin composition and the molded product of the present embodiment is improved.
Here, the (C) oil may be either a mineral oil softener or a synthetic resin softener.
The mineral oil softener is generally one or more softeners selected from the group consisting of aromatic hydrocarbons, naphthene hydrocarbons, and paraffin hydrocarbons, and is usually a mixture of these three softeners. is there.
A paraffinic oil in which the number of carbon atoms in the paraffinic hydrocarbon occupies 50% or more of the total carbon atoms is called paraffinic oil, and the number of carbon atoms in the naphthenic hydrocarbon is 30 to 45% of the total carbon atoms. Are called naphthenic oils, and those having 35% or more carbon atoms of the aromatic hydrocarbons are called aromatic oils.
Among the above, paraffinic oil is more preferable.

The paraffinic oil preferably has a kinematic viscosity at 40 ° C of 20 to 800 cst (centistokes), more preferably 50 to 600 cst, and a fluidity of preferably 0 to -40 ° C, more preferably 0 to -30 ° C. The flash point (COC method) is preferably 200 to 400 ° C, more preferably 250 to 300 ° C.
The kinematic viscosity can be measured by the method of JIS-K-2283, and the fluidity can be measured by the method of JIS-K-2269.

  Examples of the synthetic resin softener include polyalphaolefin softeners such as polybutene and low molecular weight polybutadiene, ester softeners such as polyol esters, diesters, and complex esters, dimethyl silicone, methylphenyl silicone, Examples include, but are not limited to, silicone softeners such as Gen silicone and organically modified silicone.

<(C) Oil content>
The content (mixing ratio) of the component (C) in the polyoxymethylene resin composition of the present embodiment is the component (A) described above, the component (B) described above, the component (C), and (D) described later. ) 1 to 10 parts by mass, preferably 1 to 7 parts by mass, more preferably 2 to 5 parts by mass with respect to 100 parts by mass as a total of the components.
When the content is 1 part by mass or more, the effect of oil resistance is enhanced, and when the content is 10 parts by mass or less, the impact resistance is extremely improved.

((D) Lubricant)
The polyoxymethylene resin composition of the present embodiment contains (D) a lubricant.
By adding the lubricant which is component (D), the slidability and blocking property of the polyoxymethylene resin composition of the present embodiment are improved.
Here, (D) the lubricant is a silicone-grafted polyolefin resin, alcohol, fatty acid, ester of alcohol and fatty acid, ester of alcohol and dicarboxylic acid, polyoxyalkylene glycol, and average degree of polymerization of 10 to 500. It is preferably at least one resin selected from the group consisting of certain olefin compounds.

  The silicone grafted polyolefin resin is a polyolefin resin such as low density polyethylene, linear low density polyethylene, high density polyethylene, ethylene-vinyl acetate copolymer, ethylene-methyl methacrylate copolymer, polymethylpentene. , At least one polyolefin resin selected from the group consisting of polypropylene, tetrafluoroethylene-ethylene copolymer, and the like (these may contain a small amount of a vinyl monomer such as vinyl acetate if necessary) )) Is obtained by graft polymerization of a silicone compound such as polydimethylsiloxane represented by the following general formula (6).

The methyl group in the general formula (6) is hydrogen, alkyl group, phenyl group, ether group, ester group or reactive substituents such as hydroxy group, amino group, epoxy group, cardoxyl group, carbinol group, polyether. Group, methacryl group, mercapto group, phenol group, vinyl group, allyl group, polyether group, fluorine-containing alkyl group, etc., may be substituted, and for grafting, vinyl group or allyl group It is preferably substituted with a substituent having a vinyl group, and more preferably substituted with a substituent having a vinyl group.
In addition, the average degree of polymerization n of the silicone compound represented by the general formula (6) is preferably in the range of 1000 to 10,000, and the polyoxymethylene resin of the present embodiment can be obtained by setting the average degree of polymerization n in such a range. The frictional wear characteristics and durability of the composition and the molded body thereof are excellent in practical use.

(D) A silicone-grafted polyolefin resin as a lubricant is produced by melt-kneading a polyolefin resin and a silicone compound under specific temperature and shearing conditions as described in US Pat. No. 3,658,597. can do.
Similar techniques are disclosed in U.S. Pat. No. 4,252,915 and JP-A-2-30652.
Further, these silicone compounds are more preferably those in which the contents of cyclic low-molecular monomers and oligomers are reduced as much as possible from the viewpoint of resistance to electrical contact contamination.

(D) The alcohol as the lubricant may be either a monohydric alcohol or a polyhydric alcohol. Examples of monohydric alcohols include octyl alcohol, nonyl alcohol, decyl alcohol, undecyl alcohol, lauryl alcohol, tridecyl alcohol, myristyl alcohol, pentadecyl alcohol, cetyl alcohol, heptadecyl alcohol, stearyl alcohol, Euler alcohol, nona Examples thereof include saturated or unsaturated alcohols such as decyl alcohol, eicosyl alcohol, ceryl alcohol, behenyl alcohol, melysilyl alcohol, hexyl decyl alcohol, octyldodecyl alcohol, decyl myristyl alcohol, decyl outer aryl alcohol, and unilin alcohol.
Examples of the polyhydric alcohol include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, butanediol, heptanediol, hexanediol, glycerin, diglycerin, triglycerin, threitol, erythritol, pentaerythritol, and arabitol. , Ribitol, xylitol, sorbite, sorbitan, sorbitol, mannitol and the like.

(D) Fatty acids as lubricants include, for example, caproic acid, enanthic acid, caprylic acid, pelargonic acid, capric acid, undecylic acid, lauric acid, tridecylic acid, myristic acid, pentadecylic acid, palmitic acid, stearic acid, nanodecanoic acid , Arachidic acid, behenic acid, lignoceric acid, serotic acid, heptaconic acid, montanic acid, melicic acid, laccelic acid, undecylenic acid, oleic acid, elaidic acid, celetic acid, erucic acid, brassic acid, sorbic acid, linoleic acid, linolenic acid Examples include acids, arachidonic acid, propiolic acid and stearic acid.
It may also be a naturally occurring fatty acid containing such components or a mixture thereof.
These fatty acids may be substituted with a hydroxy group.
Furthermore, the synthetic fatty acid which carried out the carboxyl modification | denaturation of the terminal of unilin alcohol which is synthetic fatty alcohol may be sufficient.

(D) The ester of alcohol and fatty acid as a lubricant is an ester of alcohol and fatty acid exemplified below.
The alcohol may be either a monohydric alcohol or a polyhydric alcohol. Examples of the monohydric alcohol include methyl alcohol, ethyl alcohol, propyl alcohol, butyl alcohol, amyl alcohol, hexyl alcohol, heptyl alcohol, octyl alcohol, and nonyl alcohol. Decyl alcohol, undecyl alcohol, lauryl alcohol, tridecyl alcohol, myristyl alcohol, pentadecyl alcohol, cetyl alcohol, heptadecyl alcohol, stearyl alcohol, euler alcohol, nonadecyl alcohol, eicoxy alcohol, ceryl alcohol, behenyl alcohol, meri Silyl alcohol, hexyl decyl alcohol, octyl dodecyl alcohol, decyl myristyl alcohol Decyl stearyl alcohol, saturated, unsaturated alcohols such as uni-phosphorus alcohol.
The polyhydric alcohol is preferably a polyhydric alcohol containing 2 to 6 carbon atoms, such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, butanediol, pentanediol, hexanediol, and glycerin. , Diglycerol, triglycerol, pentaerythritol, arabitol, ribitol, xylitol, sorbite, sorbitan, sorbitol, mannitol and the like.
Examples of fatty acids include caproic acid, enanthic acid, caprylic acid, pelargonic acid, capric acid, undecyl acid, lauric acid, tridecyl acid, myristic acid, pentadecylic acid, palmitic acid, stearic acid, nanodecanoic acid, arachic acid, behenic acid , Lignoceric acid, serotic acid, heptaconic acid, montanic acid, melicic acid, laccellic acid, undecyl acid, oleic acid, elaidic acid, celetic acid, erucic acid, brassic acid, sorbic acid, linolenic acid, linolenic acid, arachidonic acid, propiol Examples include acids and stearol acids.
It may also be a naturally occurring fatty acid containing such components or a mixture thereof.
These fatty acids may be substituted with a hydroxy group.
Moreover, the synthetic fatty acid which carried out carboxyl modification | denaturation of the terminal of unilin alcohol which is a synthetic aliphatic alcohol may be sufficient.

  Among the alcohols, fatty acids, and alcohol and fatty acid esters as the lubricant (D) described above, esters of fatty acids having 12 or more carbon atoms and alcohols are preferred, and fatty acids having 12 or more carbon atoms and alcohols having 10 or more carbon atoms and Ester is more preferable, and ester of a fatty acid having 12 to 30 carbon atoms and an alcohol having 10 to 30 carbon atoms is more preferable.

(D) The ester of alcohol and dicarboxylic acid as a lubricant is, for example, octyl alcohol, nonyl alcohol, decyl alcohol, undecyl alcohol, lauryl alcohol, tridecyl alcohol, myristyl alcohol, pentadecyl alcohol, cetyl alcohol, heptadecyl alcohol , Stearyl alcohol, Euler alcohol, Nonadecyl alcohol, Eicosyl alcohol, Seryl alcohol, Behenyl alcohol, Melylyl alcohol, Hexyldecyl alcohol, Octyldodecyl alcohol, Decylmyristyl alcohol, Decylstearyl alcohol, Unilin alcohol, etc. Primary alcohol of alcohol and oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberin , Azelaic acid, sebacic acid, Undekanin acid, Burashirin acid, maleic acid, fumaric acid, monoesters of dicarboxylic acids such as glutaconic acid, diester, and mixtures thereof.
Among these esters of alcohol and dicarboxylic acid, esters of alcohol having 10 or more carbon atoms and dicarboxylic acid are preferable.

(D) As a polyalkylene glycol compound as a lubricant, three kinds of compound groups shown in the 1st-3rd group mentioned below are mentioned.
The first group is a polycondensate having alkylene glycol as a monomer.
Examples thereof include polyethylene glycol, polypropylene glycol, block polymers of ethylene glycol and propylene glycol, and the like.
A preferable range of the number of moles of polymerization is 5 to 1000, and a more preferable range is 10 to 500.

The second group is an ether compound of a compound of the first group and an aliphatic alcohol.
For example, polyethylene glycol oil ether (ethylene oxide polymerization mole number 5-50), polyethylene glycol cetyl ether (ethylene oxide polymerization mole number 5-30), polyethylene glycol lauryl ether (ethylene oxide polymerization mole number 5-30), polyethylene glycol Examples include tridecyl ether (ethylene oxide polymerization mol number 5 to 30), polyethylene glycol nonylphenyl ether (ethylene oxide polymerization mol number 2 to 100), polyethylene glycol octyl phenyl ether (ethylene oxide polymerization mol number 4 to 50), and the like. .

The third group is an ester compound of a compound of the first group and a higher fatty acid.
For example, polyethylene glycol monolaurate (ethylene oxide polymerization mole number 2 to 30), polyethylene glycol monostearate (ethylene oxide polymerization mole number 2 to 50), polyethylene glycol monooleate (ethylene oxide polymerization mole number 2 to 50), etc. Can be mentioned.

  (D) The olefin compound having an average degree of polymerization of 10 to 500 as a lubricant is an olefin compound represented by the following general formula (7).

In the general formula (7), R ₁ and R ₂ are each independently selected from the group consisting of hydrogen, an alkyl group, an aryl group, and an ether group. The average degree of polymerization m is 10 to 500.
Examples of the alkyl group include an ethyl group, a propyl group, a butyl group, a hexyl group, an octyl group, a decyl group, a lauryl group, a cetyl group, and a stearyl group. Examples of the aryl group include a phenyl group, p -Butylphenyl group, p-octylphenyl group, p-nonylphenyl group, benzyl group, p-butylbenzyl group, tolyl group, xylyl group and the like can be mentioned.
Moreover, as an ether group, an ethyl ether group, a propyl ether group, a butyl ether group etc. are mentioned, for example.

Examples of the monomer constituting the olefin compound represented by the general formula (7) include ethylene, propylene, 1-butene, 2-butene, isobutylene, 1-pentene, 2-pentene, 4-methyl-pentene, 2 Olefins represented by -methyl-1-butene, 2-methyl-2-butene, 1-hexene, 2,3-dimethyl-2-butene, 1-heptene, 1-octene, 1-nonene, 1-decene, etc. Or diolefin monomers represented by allene, 1,2-butadiene, 1,3-butadiene, 1,3-pentadiene, 1,4-pentadiene, 1,5-hexadiene, cyclopentadiene, etc. .
A compound obtained by copolymerizing two or more of these olefinic monomers and diolefinic monomers may also be used.

  (D) When the olefin compound represented by the general formula (7) as a lubricant is a compound obtained by polymerizing a diolefin monomer, a conventional hydrogenation method is used from the viewpoint of improving thermal stability. It is preferable to use an olefin compound with as few carbon-carbon unsaturated bonds as possible.

It is preferable that the average degree of polymerization m of the olefin unit which comprises the olefin compound represented by the said General formula (7) exists in the range of 10-500, More preferably, it is the range of 15-300, More preferably, 15- A range of 100.
When the average degree of polymerization is in the range of 10 to 500, practically sufficient frictional wear characteristics can be obtained in the molded product of the polyoxymethylene resin composition of the present embodiment, and gold in molding the polyoxymethylene resin composition Good evaluation is also obtained for mold contamination.

<(D) Lubricant content>
The content (mixing ratio) of the component (D) in the polyoxymethylene resin composition of the present embodiment is the above-described (A) component, the above-described (B) component, the above-described (C) component, and (D ) 1 to 10 parts by mass, preferably 1 to 7 parts by mass, and more preferably 1 to 5 parts by mass with respect to 100 parts by mass as a total with the component.
(D) When the content (mixing ratio) of the lubricant is 1 part by mass or more, the effect of slidability and blocking is enhanced, and when the content is 10 parts by mass or less, the appearance and Impact resistance is maintained.

[Method for producing polyoxymethylene resin composition]
The polyoxymethylene resin composition of the present embodiment can be produced by melt-kneading the components (A) to (D) described above.
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 the time of melt kneading is preferably 180 to 240 ° C., and in order to maintain the quality and working environment, the inside of the system is replaced with an inert gas, or deaeration is performed with one-stage and multistage vents. It is preferable.

In addition, a method in which the components (A), (B), (C) and (D) are uniformly blended with a blender and then kneaded with a melt kneader such as an extruder may be used. After mixing the component (A) and the component (B), the mixture may be mixed with the component (A) and the component (D) and melt-kneaded.
Also, after kneading the component (B) and the component (C) at the front stage of the melt kneader such as an extruder, the components (A) and (D) are supplied to the melt kneader such as an extruder by side feed. And kneading the component (A), the component (B) and the component (D) in the previous stage of the melt kneader such as an extruder, and then the component (C) by side feed. Alternatively, a method may be used in which these are supplied to a melt kneader such as an extruder and kneaded.

[Use of polyoxymethylene resin composition]
The polyoxymethylene resin composition of the present embodiment is a material that imparts excellent impact resistance, vibration damping and noise reduction performance to the polyoxymethylene resin, and further improves oil resistance (grease resistance).
The resin composition of the present embodiment is suitable as a material for parts in precision equipment, home appliances / OA equipment, automobiles, industrial materials, miscellaneous goods, and the like.
The resin composition of the present embodiment is suitable for materials for office automation equipment, VTR equipment, music / video / information equipment, communication equipment, automobile interior / exterior parts, and industrial goods.

[Molded body using polyoxymethylene resin composition]
The molded body of the present embodiment is formed by a predetermined molding method using the above-described polyoxymethylene resin composition.
Examples of molding methods include injection molding, hot runner injection molding, outsert molding, insert molding, gas-assisted hollow injection molding, high-frequency heat injection molding of molds, compression molding, inflation molding, and blow molding. Examples include molding methods such as molding, extrusion molding, and cutting of extruded products.

  Examples of molded products include gears, cams, sliders, levers, arms, clutches, felt clutches, idler gears, pulleys, rollers, rollers, key stems, key tops, shutters, reels, shafts, joints, shafts, bearings, and guides. And mechanical parts typified by, outsert molded resin parts, and insert molded resin parts. Examples of the molded body include parts for office automation equipment such as chassis, tray, side plate, printer and copying machine, VTR (Video Tape Recorder), video movie, digital video camera, camera and digital camera. Camera or video equipment parts, cassette player, DAT, LD (Laser Disk), MD (Mini Disk), CD (CompactDisk) (CD-ROM (Read Only Memory), CD-R (Recordable), CD-RW (Including Rewritable)), DVD (Digital Versatile Disk) (including DVD-ROM, DVD-R, DVD-RW, DVD-RAM (Random Access Memory), DVD-Audio), other optical disk drives, MFD, Music, video or information represented by MO, navigation system and mobile personal computer Vessels, cellular phone and facsimile parts for communication equipment represented, parts for electrical equipment, and a component for electronic devices.

  In addition, the molded body is represented by automobile parts such as gasoline tanks, fuel pump modules, valves, fuel-related parts represented by gasoline tank flanges, door locks, door handles, window regulators, and speaker grills. Examples include parts around doors, slip rings for seat belts, press buttons, through anchors, seat belt peripheral parts represented by tongues, combination switch parts, switches and clips. Further, as the molded body, mechanical pencil parts for mechanical pencils and mechanical pencil cores, wash basins and drain outlets, drain plug opening / closing mechanism parts, vending machine opening / closing mechanism locking mechanism and product discharge mechanism parts, clothing Cord stoppers, adjusters and buttons, sprinkling nozzles and sprinkling hose connection joints, building supplies that support stair railings and flooring, disposable cameras, toys, fasteners, chains, conveyors, buckles, sports equipment, automatic Preferable examples include industrial parts such as vending machines, furniture, musical instruments, and housing equipment.

  EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited to the Example mentioned later.

First, components and evaluation methods used in Examples and Comparative Examples described later are shown below.
〔component〕
((A) polyoxymethylene resin)
<(A-1) component>
A twin-screw paddle type continuous polymerization machine with a jacket through which a heat medium can pass was adjusted to 80 ° C.
Boron trifluoride di-n-butyl etherate in which trioxane containing 4 ppm of water and formic acid is combined at 40 mol / hour, 1,3-dioxolane as cyclic formal is dissolved at 2 mol / hour in cyclohexane as a polymerization catalyst In an amount of 5 × 10 ⁻⁵ mole per 1 mole of trioxane, 1 × 10 ⁵ moles of hydroxylated hydrogenated polybutadiene (Mn = 2330) represented by the following formula (8) as a chain transfer agent per mole of trioxane: Polymerization was carried out by continuously supplying the polymerizer in an amount of ^-3 mol.
The polymer discharged from the polymerization machine was put into a 1% aqueous solution of triethylamine to completely deactivate the polymerization catalyst, and then the polymer was filtered and washed.
As a quaternary ammonium compound, triethyl (2-hydroxyethyl) ammonium formate is added to 1 part by mass of the crude polyoxymethylene copolymer after filtration and washing so that the amount of nitrogen is 20 ppm by mass. They were mixed uniformly and then dried at 120 ° C.

Next, triethylene glycol-bis [3- (3-t-butyl-5-methyl-4-hydroxyphenyl) propionate] is used as an antioxidant with respect to 100 parts by mass of the crude polyoxymethylene copolymer after drying. 0.3 parts by mass and 0.02 parts by mass of calcium stearate were added and fed to a twin screw extruder with a vent.
If necessary, water and / or triethylamine is added to the molten polyoxymethylene copolymer in the extruder under the conditions of a preset temperature of the extruder of 200 ° C. and a residence time of 5 minutes in the extruder. The unstable end was decomposed.
The polyoxymethylene copolymer (formula (9) below) having the unstable terminal portion decomposed was devolatilized under the condition of a vent vacuum of 20 Torr, and extruded from the die portion of the extruder as a strand to form a pellet.
The resulting block copolymer of the following formula (9) (A-1) has a flexural modulus of 2550 MPa and a melt flow rate of 9.3 g / 10 min (ASTM D-1238-57T). The number average molecular weight was 52,000.
In this example, the flexural modulus was measured based on ISO178, and the number average molecular weight was calculated in terms of PMMA (polymethyl methacrylate) using gel permeation chromatography (GPC).

<(A-2) component>
A jacketed twin-screw paddle type continuous polymerization machine capable of passing a heat medium was adjusted to 80 ° C., and trioxane containing 4 ppm of water and formic acid was combined at 40 mol / hour, and at the same time as cyclic formal, 1,3-dioxolane was 2 mol / hour of boron trifluoride di-n-butyl etherate dissolved in cyclohexane as a polymerization catalyst in an amount of 5 × 10 ⁻⁵ mol per 1 mol of trioxane, methylal [(CH ₃ O ) ₂ CH ₂ ] was continuously fed to the polymerization machine in an amount of 2 × 10 ⁻³ mol per 1 mol of trioxane for polymerization.
The polymer discharged from the polymerization machine was put into a 1% aqueous solution of triethylamine to completely deactivate the polymerization catalyst, and then the polymer was filtered and washed.
As a quaternary ammonium compound, triethyl (2-hydroxyethyl) ammonium formate is added to 1 part by mass of the crude polyoxymethylene copolymer after filtration and washing so that the amount of nitrogen is 20 ppm by mass. They were mixed uniformly and then dried at 120 ° C.

Next, triethylene glycol-bis [3- (3-t-butyl-5-methyl-4-hydroxyphenyl) propionate] is used as an antioxidant with respect to 100 parts by mass of the crude polyoxymethylene copolymer after drying. 0.3 parts by mass and 0.02 parts by mass of calcium stearate were added and fed to a twin screw extruder with a vent.
Water and / or triethylamine is added to the molten polyoxymethylene copolymer in the extruder as necessary, under the conditions of a preset temperature of the extruder of 200 ° C. and a residence time of 5 minutes in the extruder, The unstable end was decomposed.
The polyoxymethylene copolymer with the unstable terminal portion decomposed was devolatilized under the condition of a vent vacuum of 20 Torr, extruded as a strand from the extruder die portion, and pelletized to obtain a polyoxymethylene copolymer (A-2) (hereinafter referred to as “polyoxymethylene copolymer”). , Simply obtained pellets of “(A-2)”.
The obtained (A-2) polyoxymethylene resin had a flexural modulus of 2600 MPa, a melt flow rate of 9.0 g / 10 min (ASTM D-1238-57T), and a number average molecular weight of 55,000. .
Further, (A-2) has an oxymethylene unit and an oxyalkylene unit having 2 or more carbon atoms, and the total amount of the oxymethylene unit and the oxyalkylene unit is 100 mol%, The content was 1.3 mol%.

((B) Polymer having at least one aromatic vinyl compound-conjugated diene compound copolymer block or hydrogenated product thereof)
In a cyclohexane solvent in a reactor equipped with a stirrer substituted with nitrogen gas, n-butyllithium is used as a polymerization initiator, and an XYX structure (X: at least one polymer block mainly composed of styrene, Y A styrene-butadiene copolymer having a number average molecular weight of 100,000 and a molecular weight distribution of 1.1.
The content of all blocks X in the styrene-butadiene copolymer was 15% by mass, the total amount of bound styrene was 62% by mass, and the 1,2-vinyl bond amount of the butadiene portion was 30%.
Thereafter, the polymerization liquid is transferred to another reactor substituted with nitrogen gas, and a hydrogenation reaction is performed on the ethylenically unsaturated bond of the polybutadiene portion by the method described in US Pat. No. 4,501,857, A polymer with an addition rate of 50% was obtained.
To this polymer solution after the hydrogenation reaction, octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate as a heat deterioration stabilizer was added in an amount of 0.3 mass relative to 100 mass parts of the polymer. Then, cyclohexane as a solvent was removed by heating.
In this way, a hydrogenated polymer having at least one aromatic vinyl compound-conjugated diene compound copolymer block having a hydrogenated XYX structure was obtained.
The main dispersion peak temperature of tan δ in the viscoelastic spectrum of this polymer was 10 ° C.
In addition, in a present Example, the weight average molecular weight and the number average molecular weight were computed by polystyrene conversion by gel permeation chromatography (GPC), and molecular weight distribution was computed from the weight average molecular weight and the number average molecular weight.
The main dispersion peak temperature of tan δ in the viscoelastic spectrum was measured as follows.
First, a sheet-like sample for measurement having a width of 10 mm and a length of 35 mm was set in a twist type geometry of a rheometer device (trade name “ARES”, manufactured by TI Instruments Inc.).
Next, the effective measurement length was set to 25 mm, the strain was set to 0.5%, the frequency was set to 1 Hz, and the temperature was increased from −80 ° C. to 80 ° C. at a rate of temperature increase of 3 ° C./min to obtain a viscoelastic spectrum.
The main dispersion peak temperature of tan δ in the obtained viscoelastic spectrum was determined from a peak detected by automatic measurement of predetermined software (trade name “RSI Orchestrator”, manufactured by TI Instruments Inc.).

((C) Oil)
(C) Diana process oil PW380 (made by Idemitsu Kosan Co., Ltd., trade name) was used as the oil.

((D) Lubricant)
<(D-1)> Melt index MI (ASTM-D1238-57T) containing 5% by mass of methyl methacrylate using Labo Plastomil (manufactured by Toyo Seiki Co., Ltd.) = A silicone compound was added to a polyolefin obtained by melt-kneading 30 g of an ethylene-methyl methacrylate copolymer of 5 g / 10 min and 30 g of a silicone compound of the following formula (10) at a temperature = 180 ° C. and a rotation speed = 60 rpm for 20 minutes. Grafted resin was used.

  The graft ratio of the silicone compound in the silicone-grafted polyolefin resin was 85% by mass, and the free silicone compound was 11% by mass.

<(D-2)> Cetyl myristate

〔Evaluation methods〕
(1) Evaluation of mechanical properties (impact resistance) 5 ounce molding machine (Toshiba Machine Co., Ltd.) set at a cylinder temperature of 205 ° C after drying the pellets obtained in Examples and Comparative Examples at 80 ° C for 3 hours. ISO dumbbell test pieces for physical property evaluation were molded under the conditions of a mold temperature of 90 ° C., an injection time of 35 seconds, and a cooling time of 15 seconds using a product name “IS-100GN”).
The following tests were performed on this test piece.
(I) Tensile elongation: measured based on ISO 527-1 & -2.
(Ii) Charpy impact strength; measured based on ISO 179 / 1eA.

(2) Oil resistance After the pellets obtained in Examples and Comparative Examples were dried at 80 ° C. for 3 hours, a 5-ounce molding machine set to a cylinder temperature of 200 ° C. (trade name “IS-” manufactured by Toshiba Machine Co., Ltd.) 100 GN "), a 30φ gear test piece was molded under conditions of a mold temperature of 70 ° C, an injection time of 20 seconds, and a cooling time of 15 seconds. The test piece was tested for oil resistance as follows.
First, the gear inner diameter (D1) of the test piece was measured using a micro gauge. Thereafter, grease (trade name “PG641”, olefin grease, manufactured by Dow Corning) was applied to the opening of the test piece, and heat treatment was performed in a gear oven heated to 70 ° C. for 9 hours.
After removing the test piece from the oven, the grease was wiped off, the gear inner diameter (D2) of the test piece was measured, and ((D1)-(D2)) was evaluated as oil resistance (μm). The “oil resistance” was judged to be better when the above value was smaller.

(3) Loss coefficient In the anechoic chamber, one end of a test piece similar to that used for mechanical property evaluation was fixed, and the sound emitted when the root of the fixed end was struck with an impulse hammer. The loss coefficient was obtained from the frequency response function of the hammer excitation force signal and the microphone sound pressure signal using an acoustic analysis system manufactured by Ono Sokki Co., Ltd.
A large loss factor (%) was judged to mean excellent vibration damping and noise reduction performance.

(4) Reciprocating slidability Set a test piece similar to that used for mechanical property evaluation on a reciprocating friction and wear tester (trade name “AFT-15MS” manufactured by Toyo Seimitsu Co., Ltd.) and load The sample was reciprocated 10,000 times under the conditions of 1 kg, linear velocity of 30 mm / second, reciprocating distance of 20 mm, and environmental temperature of 23 ° C., and the coefficient of friction and the amount of wear were measured.
As a sliding partner material, SUS304 (austenitic stainless steel) precision sphere (diameter 5 mm, tip R = 2.5 mm) was used.
Evaluation method: Friction coefficient and wear amount are measured. Friction coefficient is 0.35μ or less, wear amount (depth) is 50μm or less as standard, 1 satisfying at the same time, 2 satisfying only one, 3 as not satisfying evaluated.

(5) Blocking properties The pellets obtained in the examples and comparative examples were put in a metal pad, dried at 80 ° C. for 3 hours, and then evaluated for blocking properties (degree of lump).
Evaluation method: Evaluation was made as 1 for non-blocking, 2 for small blocking and easy to mold similarly to 1, and 3 for large blocking and difficult to mold.

[Example 1]
(A-1) 20 parts by mass of component, 70 parts by mass of (B) component, and 3 parts by mass of (D-1) component were mixed uniformly with a blender, and then the mixture was set at 200 ° C. / D = 48 was supplied to the top of a 26 mmφ twin screw extruder (trade name “TEM-26SS” manufactured by Toshiba Machine Co., Ltd.) using a weight type feeder.
Furthermore, 7 parts by mass of component (C) was supplied to the extruder using a liquid addition device, and melt kneaded under the conditions of a screw rotation speed of 120 rpm and an extrusion speed of 11 kg / hour to obtain a resin composition. .
The extruded resin composition was pelletized with a strand cutter.
The above various measurements were performed using the obtained pellets. The results are shown in Table 1 below.

[Example 2]
(A-1) component 20 parts by mass, (B) component 70 parts by mass, (D-1) component 3 parts by mass, and triethylene glycol-bis- [3- (3-t-butyl- 5-methyl-4-hydroxyphenyl) propionate] 0.3 parts by mass, polyamide 66 0.05 parts by mass, and calcium stearate 0.13 parts by mass were mixed uniformly with a blender, and then set to 200 ° C. In addition, a 26 mmφ twin screw extruder (trade name “TEM-26SS” manufactured by Toshiba Machine Co., Ltd.) with L / D = 48 was supplied using a weight type feeder.
Furthermore, 7 parts by mass of component (C) are supplied to the extruder using a liquid addition apparatus, and melt kneaded under the conditions of a screw rotation speed of 120 rpm and an extrusion speed of 11 kg / hour to obtain a resin composition. It was.
The extruded resin composition was pelletized with a strand cutter.
The above various measurements were performed using the obtained pellets. The results are shown in Table 1 below.

Example 3
(B) A weight type feeder is placed on the top of a 26 mmφ twin screw extruder (trade name “TEM-26SS” manufactured by Toshiba Machine Co., Ltd.) with L / D = 48 set to 90.9 parts by mass of component 90.9 parts. 9.1 parts by mass of component (C) is supplied to the extruder using a liquid addition device, and melt kneading is performed under the conditions of a screw rotation speed of 150 rpm and an extrusion speed of 15 kg / hour. A resin composition of component B) and component (C) was obtained. The extruded resin composition was pelletized with a strand cutter.
77 parts by mass of the obtained resin composition of component (B) and component (C), 20 parts by mass of component (A-1), 3 parts by mass of component (D-1), and triethylene glycol as a stabilizer -0.3 parts by weight of bis- [3- (3-tert-butyl-5-methyl-4-hydroxyphenyl) propionate], 0.05 parts by weight of polyamide 66, and 0.13 parts by weight of calcium stearate were added. After mixing uniformly with a blender, a weight type feeder is used at the top of a 26 mmφ twin screw extruder (trade name “TEM-26SS” manufactured by Toshiba Machine Co., Ltd.) with L / D = 48 set to 200 ° C. The mixture was melt kneaded under the conditions of a screw rotation speed of 120 rpm and an extrusion speed of 11 kg / hour to obtain a resin composition.
The extruded resin composition was pelletized with a strand cutter.
The above various measurements were performed using the obtained pellets. The results are shown in Table 1 below.

[Examples 4 to 10]
The composition of the component (A-1), the component (B), the component (C), and the component (D-1) (unit: parts by mass, the same applies hereinafter) was changed as shown in Table 1 below.
Other conditions were the same as in Example 1 to obtain pellets of the resin composition.
The above various measurements were performed using the obtained pellets. The results are shown in Table 1 below.

[Examples 11 to 13]
As the component (A), the components (A-1) and (A-2) were used in the composition shown in Table 1 below.
Other conditions were the same as in Example 5 to obtain pellets of the resin composition.
The above various measurements were performed using the obtained pellets. The results are shown in Table 1 below.

Example 14
As the component (D), the component (D-1) was changed to the component (D-2).
Other conditions were the same as in Example 10 to obtain pellets of the resin composition.
The above various measurements were performed using the obtained pellets. The results are shown in Table 1 below.

[Comparative Examples 1-5]
Component (A), component (B), component (C), and component (D) were used in the composition shown in Table 1 below.
Other conditions were the same as in Example 1 to obtain pellets of the resin composition.
The above various measurements were performed using the obtained pellets. The results are shown in Table 2 below.

  By using the polyoxymethylene resin compositions of Examples 1 to 14, a molded product having excellent oil resistance in addition to excellent impact resistance, vibration damping performance and sliding property can be obtained, and polyoxymethylene resin It was found that the composition also has excellent blocking properties.

The polyoxymethylene resin composition of the present invention is a mechanical component (for example, gear, cam, slider, lever, arm, clutch, joint, shaft, bearing, key stem and key) obtained by molding, cutting, or molding / cutting. At least one member selected from the group consisting of the top), at least one member selected from the group consisting of the resin component of the outsert chassis, the chassis, the tray, and the side plate, and can be used for the following applications.
(1) Parts used for OA equipment represented by printers and copiers, (2) Parts used for video equipment represented by VTRs and video movies, (3) Cassette players, LD, MD, CD (including CD-ROM, CD-R, CD-RW), DVD (including DVD-ROM, DVD-R, DVD-RAM, DVD-Audio), music, video represented by navigation systems and mobile computers, or Parts used for information equipment, (4) Parts used for communication equipment represented by mobile phones and facsimiles, (5) Clips, through anchors, tongues, fuel tanks, fuel used for automobile interior and exterior parts Parts used for the tank and its peripheral parts, and (6) disposable cameras, toys, fasteners, conveyors, buckles And there is a APPLICABILITY industry parts used in industrial goods represented by housing equipment.

Claims (7)

(A) Polyoxymethylene resin: 20 to 95 parts by mass;
(B) A polymer having at least one vinyl aromatic compound-conjugated diene compound copolymer block and a tan δ main dispersion peak temperature in a viscoelastic spectrum of 60 ° C. or lower, or a hydrogenated product thereof: 3 to 78 Part by mass;
(C) Oil: 1 to 10 parts by mass,
(D) Lubricant: 1 to 10 parts by mass,
The polyoxymethylene resin composition in which the total amount of the component (A), the component (B), the component (C), and the component (D) is 100 parts by mass. The said (A) component contains the polyoxymethylene block copolymer of the number average molecular weight 10000-500000 represented by following General formula (1) as (A-1) component. Methylene resin composition.
HR ³ —O— (CR ¹ ₂ ) _k —R ⁴ — (CR ¹ ₂ ) _k —O—R ³ —H (1)
(In general formula (1),
R ¹ each independently represents a chemical species selected from the group consisting of a hydrogen atom, a substituted or unsubstituted alkyl group, and a substituted or unsubstituted aryl group, and may be the same or different from each other. .
k shows the integer of 2-6 each independently.
R ³ represents a block having a plurality of oxymethylene units represented by the following general formula (2a) and oxyhydrocarbon units represented by the following general formula (2b), wherein the oxymethylene unit and the oxyhydrocarbon unit Are present at random, and the total amount of the oxymethylene unit and the oxyhydrocarbon unit is 100 mol%, the content of the oxymethylene unit is 95-99.9 mol%, Content is 0.1-5 mol%, and the average of the number average molecular weight of two R < ³ > is 5000-250,000.
In the following general formula (2b), each R ² independently represents a chemical species selected from the group consisting of a hydrogen atom, a substituted or unsubstituted alkyl group, and a substituted or unsubstituted aryl group, and is the same as each other. It may be present or different, and j represents an integer of 2 to 6.
R ⁴ represents a block having a plurality of ethylene units represented by the following general formula (3a) and n-butylene units represented by the following general formula (3b), and the ethylene unit and the n-butylene unit are: Relative to each other or in blocks, the ethylene unit content is 2 to 98 mol% and the n-butylene unit content is 2 with respect to 100 mol% of the total amount of the ethylene unit and the n-butylene unit. It is -98 mol%, A number average molecular weight is 500-10000, You may have an unsaturated bond of iodine number 20g-I < ₂ > / 100g or less. )
— (CH ₂ O) — (2a)
-((CR ² ₂ ) _j -O)-(2b)
_{- (CH 2 CH 2) -} ··· (3a)
_{- (CH 2 CH 2 CH 2} CH 2) - ··· (3b) The component (A) has an oxymethylene unit and an oxyalkylene unit having 2 or more carbon atoms as the component (A-2) different from the component (A-1), and the oxymethylene unit and the oxyalkylene. A polyoxymethylene copolymer having a content of the oxyalkylene unit of 0.1 to 10 mol% based on the total amount of the unit,
The polyoxymethylene according to claim 2, wherein a mass ratio (A-1) / (A-2) of the component (A-1) to the component (A-2) is 99/1 to 10/90. Resin composition.   The polyoxymethylene resin composition according to claim 2, wherein the component (A) is the component (A-1).   5. The polyoxymethylene resin composition according to claim 1, wherein a main dispersion peak temperature of the tan δ in the viscoelastic spectrum of the component (B) is in a range of 60 ° C. to −20 ° C. 6.   The component (D) is a silicone-grafted polyolefin resin, alcohol, fatty acid, ester of alcohol and fatty acid, ester of alcohol and dicarboxylic acid, polyoxyalkylene glycol, and olefin compound having an average degree of polymerization of 10 to 500 The polyoxymethylene resin composition according to any one of claims 1 to 5, which is at least one resin selected from the group consisting of:   The molded object shape | molded using the polyoxymethylene resin composition as described in any one of Claims 1 thru | or 6.