JP5783685B2 - Polyoxymethylene slide parts - Google Patents

Description

  The present invention relates to a polyoxymethylene slide part.

  Oxymethylene resin is a resin with high mechanical strength and rigidity, excellent oil resistance and organic solvent resistance, balanced in a wide temperature range, and easy to process. It is used for a wide range of applications, centering on mechanical parts of equipment, automobile parts and other mechanical parts. Oxymethylene resins are originally used for various slide parts because of their excellent self-lubricating properties.

  For slide parts, the durability of the members depends on the shape of the various slide parts such as faces and faces, faces and lines, faces and points, and the sliding environment such as the contact state where the slide faces are always constant or updated. Friction and wear changes. In particular, since a tendency has not been simply derived for the friction resistance and wear resistance between resins, many proposals have been made so far.

  About an oxymethylene resin composition, in order to improve friction resistance and abrasion resistance, various structures are mentioned. For example, a polyoxymethylene resin composition comprising a polyacetal resin, diester, or monoester is excellent in friction resistance and wear resistance in discontinuous contact and discontinuous movement between a test piece made of the composition and a sphere made of SUS material. (For example, refer to Patent Document 1) and a polyoxymethylene molding composition containing a polyoxymethylene copolymer and a lubricant such as ester wax and polyethylene wax, a shaft comprising a ring made of the composition and steel It has been reported that it is excellent in friction resistance and wear resistance in continuous contact / continuous movement, and the use of the composition and a molded product have been proposed (for example, see Patent Document 2). ).

  Various reports have been made on the combination of a member for sliding and a mating member of the member. For example, in a guide slider for a window raising / lowering mechanism, by combining a spherical material made of PBT resin and a guide made of polyacetal resin, the occurrence of looseness in discontinuous contact / discontinuous movement can be improved (for example, ), And a wear resistant connector for modular link type conveyor belts, by combining a polyester or polyamide coated rod with an acetal link, it is resistant to continuous contact and discontinuous movement. There have been reports of excellent friction and wear properties (see, for example, Patent Document 4).

  Moreover, various forms are mentioned about utilization to the slide components of oxymethylene resin. For example, in a sliding member and a door check device using the sliding member, a polyacetal is used as a shoe to obtain discontinuous contact between the shoe and an arm, wear resistance and smooth slidability during discontinuous movement. A composition comprising a resin, a thermoplastic polyester elastomer, and a lubricant is used, and polyamide is used as an arm (see, for example, Patent Document 5), or in a steering device, a continuation by a cam made of carbon steel and a non-rotating member. In order to improve the slidability and the hitting sound at the time of general contact and discontinuous movement, there has been proposed such as using polyacetal as a material for the rotation preventing member (for example, see Patent Document 6).

JP-A-8-283530 Special table 2004-503646 gazette JP-A-10-227176 Special table 2009-506962 gazette Japanese Patent Laid-Open No. 2005-187591 JP 2008-307959 A

  In recent years, from the viewpoint of weight reduction and economy, there has been an active movement to change the material used from metal to resin, and the slide mechanism of resin and resin is also increasing in slide parts. For these resin slide parts, smooth operation and long-term durability are required as in the conventional case.

  However, various members using oxymethylene resins disclosed in Patent Documents 1 to 6 still have room for improvement in terms of operability and durability when sliding with a resin material having a specific hardness.

  Accordingly, an object of the present invention is to provide a polyoxymethylene slide part capable of realizing high operability and excellent durability while ensuring practically sufficient productivity.

  As a result of intensive studies in order to solve the above problems, the present inventors, as a member contacting when sliding with a resin material having a specific hardness, a member formed using a specific oxymethylene resin composition As a result, it has been found that a slide part having high operability and excellent durability can be obtained, and the present invention has been completed.

  That is, the present invention is as follows.

[1]
A slide component comprising a member (I) formed using an oxymethylene resin composition and a counterpart material (II) in contact with the member (I),
The oxymethylene resin composition contains 90% by mass or more of polyoxymethylene (A) and 0.5 to 2.5% by mass of fatty acid ester (B),
A slide part made of polyoxymethylene, wherein the counterpart material (II) is formed using a resin other than polyoxymethylene resin and has a Rockwell hardness (M scale) of 50 to 110.

[2]
The polyoxymethylene slide part according to [1], wherein the fatty acid ester (B) is a diester.

[3]
The polyoxymethylene slide part according to [1] or [2], wherein the fatty acid ester (B) is solid at room temperature.

[4]
The polyoxymethylene slide part according to any one of [1] to [3], wherein the counterpart material is formed using a polyamide-based resin.

[5]
[1] to [4], wherein the polyoxymethylene (A) contains a comonomer component other than the oxymethylene component in an amount of 0 to 1.35 mol% with respect to 100 mol% of the oxymethylene component. The slide part made from polyoxymethylene in any one.

[6]
Use of the polyoxymethylene slide part according to any one of [1] to [5], wherein the polyoxymethylene slide part is used.

[7]
A method of using a slide component comprising a member (I) formed using an oxymethylene resin composition and a counterpart material (II) in contact with the member (I),
The method for using a polyoxymethylene slide part according to [6], wherein the steady sliding surface pressure between the member (I) and the counterpart material (II) is 20 to 150 MPa.

[8]
A method of using a slide component comprising a member (I) formed using an oxymethylene resin composition and a counterpart material (II) in contact with the member (I),
Use of the slide part made of polyoxymethylene according to [6], wherein the steady sliding linear velocity between the member (I) and the counterpart material (II) is 0.08 to 2.3 m / sec. Method.

[9]
The method for using a polyoxymethylene slide part according to any one of [1] to [5], wherein the polyoxymethylene slide part is constantly and intermittently operated.

  According to the present invention, it is possible to obtain a polyoxymethylene slide part which is improved in terms of operability and durability when sliding with a resin material having a specific hardness while ensuring practically sufficient productivity.

It is the figure which showed an example (example 1) of the slide component which concerns on this embodiment. It is the figure which showed an example (example 2) of the slide component which concerns on this embodiment. It is the figure which showed an example (example 3) of the slide components which concern on this embodiment. It is the schematic of the apparatus which evaluates the slide components obtained in the present Example.

  Hereinafter, modes 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.

  The usage aspect of the polyoxymethylene slide part and the polyoxymethylene slide part of this embodiment will be described in detail sequentially.

[Polyoxymethylene slide parts]
The slide part made of polyoxymethylene of this embodiment is a slide part including a member (I) formed using an oxymethylene resin composition, and a counterpart material (II) in contact with the member (I), The oxymethylene resin composition contains 90% by mass or more of polyoxymethylene (A) and 0.5 to 2.5% by mass of fatty acid ester (B), and the counterpart material (II) is other than polyoxymethylene resin. The resin has a Rockwell hardness (M scale) of 50 to 110.

[Member (I)]
The polyoxymethylene slide part of the present embodiment includes a member (I) formed using a specific oxymethylene resin composition described later.

[Oxymethylene resin composition]
The oxymethylene resin composition used in the present embodiment contains the following polyoxymethylene (A) as a main component, and further contains a specific amount of fatty acid ester (B). Here, the “main component” means that polyoxymethylene (A) is contained in an amount of 90% by mass or more, preferably 95% by mass or more in the oxymethylene resin composition.

(Polyoxymethylene (A))
The polyoxymethylene (A) used in this embodiment is a polyoxymethylene homopolymer (A-1) having only an oxymethylene group in the main chain, or an oxyalkylene unit having 2 or more carbon atoms in the molecule. It is a polyoxymethylene copolymer (A-2).

  The polyoxymethylene (A) preferably contains a comonomer component other than the oxymethylene component in an amount of 0 to 1.35 mol% with respect to 100 mol% of the oxymethylene component, and contains 0 to 1.33 mol%. More preferably, it is more preferably 0 to 1.31 mol%. When the content of the comonomer component other than the oxymethylene component is within the above range, the slide part including the member (I) formed using the oxymethylene resin composition can maintain high productivity and has excellent operability. And tends to be durable.

For quantification of the comonomer component, ¹ H-NMR method is used. As the procedure, the obtained polyoxymethylene (A) was dissolved in hexafluoroisopropanol (HFIP) so as to have a concentration of 1.5% by mass over 24 hours, and ¹ H-NMR was used using this solution. The ratio of the comonomer component b to 100 mol% of the oxymethylene component (from the ratio of the integral value of the assigned peak of the oxymethylene component a and the comonomer component other than the oxymethylene component a (for example, the oxyalkylene component) b is analyzed. b / a) can be determined.

  The polyoxymethylene homopolymer (A-1) and the polyoxymethylene copolymer (A-2) can be produced by the following polymerization process, terminal stabilization process and granulation process.

<Polyoxymethylene homopolymer (A-1)>
(1) Polymerization process The polyoxymethylene homopolymer (A-1) used in the present embodiment represents a polymer having an oxymethylene group in the main chain. Both ends of the polymer chain may be blocked with an ester group or an ether group. The polymerization form in the production of the polyoxymethylene homopolymer (A-1) can be carried out using a known slurry polymerization method (for example, Japanese Patent Publication Nos. 47-6420 and 47-10059). Thereby, the crude polyoxymethylene whose terminal is not stabilized can be obtained.

1) Monomer As the monomer used for the production of the polyoxymethylene homopolymer (A-1), for example, formaldehyde can be used. At this time, in order to continuously obtain a polyoxymethylene homopolymer (A-1) having a stable molecular weight, it is preferable to use a formaldehyde gas which is purified and has a low impurity concentration and is stable. A known method (for example, Japanese Patent Publication No. 5-32374 and Japanese Patent Publication No. 2001-521916) can be used as a purification method of formaldehyde.

  The formaldehyde gas used in the present embodiment is preferably one that contains as little impurities as possible, such as water, methanol, and formic acid, which have a polymerization termination and chain transfer action during the polymerization reaction. When these impurities are excessively present, there is a tendency that the polyoxymethylene homopolymer (A-1) having a target molecular weight cannot be obtained due to an unexpected chain transfer reaction. In particular, water is preferably 100 ppm or less, and more preferably 50 ppm or less.

2) Chain transfer agent As chain transfer agent used for manufacture of polyoxymethylene homopolymer (A-1), alcohols and acid anhydrides can be generally used. In order to obtain a block polymer or a branched polymer, a polyol, a polyether polyol, or a polyether polyol / alkylene oxide may be used.

  Moreover, it is preferable to use a chain transfer agent that does not contain impurities as much as possible. Among these, water is preferably 2000 ppm or less, more preferably 1000 ppm or less. As a method for obtaining these chain transfer agents with a small amount of impurities, for example, a general-purpose chain transfer agent having a water content exceeding a specified amount is obtained, and this is bubbled with dry nitrogen, and an adsorbent such as activated carbon or zeolite. And a method of removing impurities and purifying them. The chain transfer agent used here may be used alone or in combination of two or more.

3) Polymerization catalyst Examples of the polymerization catalyst used for the polymerization reaction in the production of the polyoxymethylene homopolymer (A-1) include onium salt polymerization catalysts. As the onium salt-based polymerization catalyst used in the polymerization reaction, those represented by the following general formula (1) can be used.

[R ₁ R ₂ R ₃ R ₄ M] ⁺ X ⁻ (1)
In the general formula (1), R ₁ , R ₂ , R ₃ and R ₄ each independently represents an alkyl group, M represents an element having a lone pair, and X represents a nucleophilic group.

  Among the onium salt polymerization catalysts represented by the general formula (1), quaternary ammonium salt compounds and quaternary phosphonium salt compounds are preferably used. More preferably, tetramethylammonium bromide, dimethyl distearyl ammonium acetate, tetraethylphosphonium iodide, or tributylethylphosphonium iodide is used.

4) Reactor As a polymerization reactor in the production of the polyoxymethylene homopolymer (A-1), there are a batch type reaction vessel with a stirrer, a continuous type kneader, a twin screw type continuous extrusion kneader, and a twin screw paddle. A type continuous mixer or the like can be used. The outer peripheries of these cylinders preferably have a structure capable of heating or cooling the reaction mixture.

(2) Terminal stabilization step As a method for blocking the terminal stabilization of the crude polyoxymethylene with an ether group, there is a method described in JP-B 63-452, and a method for blocking with an acetyl group is the United States. A method of using a large amount of acid anhydride described in Japanese Patent No. 3,459,709 in a slurry state and an acid anhydride gas described in US Pat. No. 3,172,736 There is a method in the gas phase. In the present embodiment, any of the above methods can be adopted and is not particularly limited.

  The etherifying agent used for blocking with an ether group includes orthoesters, usually orthoesters of aliphatic or aromatic acids with aliphatic, alicyclic or aromatic alcohols. Specific examples of such orthoesters include methyl or ethyl orthoformate, methyl or ethyl orthoacetate and methyl or ethyl orthobenzoate, and orthocarbonates such as ethyl orthocarbonate.

  The etherification reaction is carried out using a Lewis acid type catalyst such as p-toluenesulfonic acid, medium strength organic acids such as acetic acid and hydrobromic acid, medium strength mineral acids such as dimethyl and diethyl sulfate, etc. It may be performed by introducing 0.001 to 0.02 part by weight with respect to part.

  Preferred solvents used in the etherification reaction include low-boiling aliphatics such as pentane, hexane, cyclohexane and benzene, alicyclic and aromatic hydrocarbons, halogenated lower aliphatic compounds such as methylene chloride, chloroform and carbon tetrachloride, etc. These organic solvents are mentioned.

  On the other hand, when the terminal of the polymer is blocked with an ester group, examples of the organic acid anhydride used for esterification include organic acid anhydrides represented by the following general formula (2).

R ₅ COOCOR ₆ (2)
In the general formula (2), R ₅ and R ₆ each independently represents an alkyl group. R ₅ and R ₆ may be the same or different.

  Among the organic acid anhydrides represented by the general formula (2), propionic anhydride, benzoic anhydride, acetic anhydride, succinic anhydride, maleic anhydride, glutaric anhydride, phthalic anhydride and the like are preferable, and acetic anhydride is preferable. Particularly preferred. One organic acid anhydride may be used, but two or more organic acid anhydrides may be used.

  Further, in the method of performing ester group blocking in the gas phase, if the onium salt polymerization catalyst remains in the polyoxymethylene, the onium salt polymerization catalyst will cause the polyoxymethylene decomposition reaction when the end blockage occurs. Since the problem of facilitating the reduction of the polymer yield in the stabilization reaction and the problem of coloring the polyoxymethylene appears particularly prominently, the onium salt-based polymerization catalyst is removed by the method described in JP-A-11-92542. It is particularly preferable to perform end capping after the treatment.

The end of polyoxymethylene is preferably blocked with an ether group and / or an ester group, so that the concentration of the terminal hydroxyl group is reduced to 5 × 10 ⁻⁷ mol / g or less. When the concentration of the terminal hydroxyl group is more than 5 × 10 ⁻⁷ mol / g, the thermal stability is impaired, and the quality of the original polyoxymethylene resin is lowered, which is not preferable. More preferably, the concentration of the terminal hydroxyl group is 0.5 × 10 ⁻⁷ mol / g or less.

(3) Granulation step After the terminal stabilized polyoxymethylene powder is dried, it may be granulated using an extruder in order to improve the handleability. At this time, it is preferable to perform granulation by melt mixing while adding a known stabilizer that can be added to ordinary polyoxymethylene. When performing melt-kneading, it is preferable to carry out replacement with an inert gas and deaeration with a single-stage or multistage vent in order to maintain quality and working environment. The temperature at the time of melt-kneading is preferably from the melting point of the polyoxymethylene homopolymer (A-1) to 250 ° C.

<Polyoxymethylene copolymer (A-2)>
(1) Polymerization process The polymerization form in the production of the polyoxymethylene copolymer (A-2) used in the present embodiment is 1.35 mol% or less of comonomer components other than the oxymethylene component with respect to 100 mol% of oxymethylene. It is preferably contained, more preferably 1.33 mol% or less, and even more preferably 1.31 mol% or less.
Both ends of the polymer chain may be blocked with an ester group or an ether group. The polymerization form in the production of the polyoxymethylene homopolymer (A-2) is a known polymerization method (for example, US-A-3027352, US-A-3803094, DE-C-11141421, DE-C-1495228, DE- C-1720358, DE-C-3018898, JP-A-58-98322, and JP-A-7-70267) can be used. Such a polymerization step yields a crude polymer in which the end of the polyoxymethylene copolymer is not stabilized.

  Materials such as main monomers used in the polymerization step will be described below.

1) Main monomer As the main monomer used in the production of the polyoxymethylene copolymer (A-2), it is preferable to use cyclic oligomers such as formaldehyde or its trimer trioxane or tetramer tetraoxane.

  Here, the “main monomer” in this specification refers to a monomer component contained in an amount of 50% by mass or more based on the total amount of monomers.

2) Comonomer As the comonomer used for producing the polyoxymethylene copolymer (A-2), it is preferable to use a cyclic ether compound having an oxyalkylene unit having 2 or more carbon atoms in the molecule.

  Examples of such cyclic ether compounds include ethylene oxide, propylene oxide, 1,3-dioxolane, 1,3-propanediol formal, 1,4-butanediol formal, 1,5-pentanediol formal, and 1,6-hexanediol. One compound selected from the group consisting of formal, diethylene glycol formal, 1,3,5-trioxepane, 1,3,6-trioxycan, and a mono- or di-glycidyl compound capable of constituting a branched or crosslinked structure in the molecule or Mixtures of two or more are listed as suitable.

  When polymerizing the polyoxymethylene copolymer (A-2), as the main monomer and comonomer, those containing as little impurities as possible, such as water, methanol and formic acid, which have a polymerization stopping action and a chain transfer action during the polymerization reaction are used. It is preferable.

  By using a main monomer and a comonomer containing as little impurities as possible, an unexpected chain transfer reaction can be avoided, and a polymer having a desired molecular weight can be obtained.

  In particular, the content of impurities that induce hydroxyl groups in the polymer end groups is preferably 30 ppm by mass or less, more preferably 10 ppm by mass or less, and even more preferably 3 ppm by mass or less, based on the total amount of monomers. .

  As a method for obtaining a desired low-impurity main monomer and comonomer, known methods (for example, for the main monomer, JP-A-3-123777 and JP-A-7-33761, for the comonomer, No. 49-62469 and JP-A-5-271217) can be used.

3) Chain transfer agent It is preferable to use a chain transfer agent in the polymerization step of the polyoxymethylene copolymer (A-2).

  As the chain transfer agent, for example, formaldehyde dialkyl acetals and oligomers thereof, and lower aliphatic alcohols such as methanol, ethanol, propanol, isopropanol and butanol are preferably used. The alkyl group of the dialkyl acetal is preferably a lower aliphatic alkyl group such as methyl, ethyl, propyl, isopropyl and butyl.

  In order to obtain a long-chain branched polyoxymethylene, it is preferable to use a polyether polyol and an alkylene oxide adduct of the polyether polyol.

  Moreover, as a chain transfer agent, you may use the polymer which has 1 or more types of groups selected from the group which consists of a hydroxyl group, a carboxyl group, an amino group, an ester group, and an alkoxy group.

  Furthermore, the said chain transfer agent may be used individually by 1 type, and may use 2 or more types. In any case, those having a small number of unstable terminals are preferred.

4) Polymerization catalyst The polymerization catalyst used in the polymerization step of the polyoxymethylene copolymer (A-2) is preferably a cationically active catalyst such as Lewis acid, protonic acid, and ester or anhydride of protonic acid.

  The Lewis acid is not particularly limited, and examples thereof include boric acid, tin, titanium, phosphorus, arsenic, and antimony halides. Specific examples include boron trifluoride, tin tetrachloride, titanium tetrachloride, phosphorus pentafluoride, phosphorus pentachloride and antimony pentafluoride, and complex compounds or salts thereof.

  Specific examples of the protonic acid, its ester or anhydride are not particularly limited, but perchloric acid, trifluoromethanesulfonic acid, perchloric acid-tertiary butyl ester, acetyl perchlorate, and trimethyloxonium hexafluorophosphate are included. Can be mentioned. If necessary, for example, a catalyst for reducing the formation of terminal formate groups described in JP-A No. 05-05017 may be used in combination. Among these, boron trifluoride; boron trifluoride hydrate; a coordination complex compound of an organic compound containing oxygen atom or sulfur atom and boron trifluoride is preferable, boron trifluoride diethyl ether, trifluoride Boron di-n-butyl ether is more preferred.

For example, when trioxane and cyclic ether and / or cyclic formal are used, the polymerization catalyst is preferably used in an amount of 1 × 10 ⁻⁶ mol to 1 × 10 ⁻³ mol with respect to 1 mol of the total monomer. ^-6 mol to 1 × 10 ^-4 mol is more preferable.

  When the usage-amount of a polymerization catalyst is in the said range, the reaction stability at the time of superposition | polymerization and the thermal stability of the molded object obtained will improve more.

  The polymerization catalyst can be deactivated after the polymerization step by introducing the polymer into an aqueous solution or organic solvent solution containing a catalyst neutralization deactivator and stirring in a slurry state for generally several minutes to several hours. it can.

  The catalyst neutralization deactivator is not particularly limited, but examples thereof include amines such as ammonia, triethylamine and tri-n-butylamine, and alkali metal and alkaline earth metal hydroxides, inorganic acid salts, and organic acids. 1 or more types selected from the group which consists of salt are mentioned.

  In addition, the catalyst is deactivated by contacting a vapor such as ammonia and triethylamine with polyoxymethylene to deactivate the polymerization catalyst, or by contacting with at least one of hindered amines, triphenylphosphine and calcium hydroxide in a mixer. A deactivation method can also be used.

(2) Terminal stabilization step and granulation step An oxymethylene resin composition is obtained by decomposing and removing unstable terminal portions contained in the crude polymer of the polyoxymethylene copolymer (A-2) obtained by the polymerization step described above. To obtain a polyoxymethylene copolymer (A-2).

  The method for decomposing and removing the unstable terminal portion contained in the crude polymer is not particularly limited. For example, a known basic substance can be obtained using a vented single-screw extruder or a vented twin-screw extruder. In the presence of a decomposition / removal agent to be described later, there is a method in which the crude polymer is melted to decompose and remove the unstable terminal portion.

  When performing melt-kneading for terminal stabilization, it is preferable to perform replacement with an inert gas and deaeration with single-stage and multistage vents in order to maintain quality and working environment.

  The temperature at the time of melt-kneading is preferably not lower than the melting point of the polyoxymethylene copolymer (A-2) and not higher than 260 ° C.

  Furthermore, it is preferable to perform granulation by melt mixing while adding a known stabilizer that can be added to ordinary polyoxymethylene.

1) Decomposition removing agent Examples of the decomposing / removing agent used for decomposing and removing the unstable terminal portion contained in the crude polymer of the polyoxymethylene copolymer (A-2) include aliphatic amines such as ammonia, triethylamine and tributylamine, and Well-known basic substances such as alkali metal or alkaline earth metal hydroxides such as calcium hydroxide, inorganic weak acid salts and organic weak acid salts may be mentioned.

  Among the decomposition and removal agents, at least one quaternary ammonium compound represented by the following general formula (3) is preferable.

  A method of treating a thermally unstable terminal using such a quaternary ammonium compound can be suitably used.

[R ₇ R ₈ R ₉ R ₁₀ N ⁺ ] _n Y _n ⁻ (3)
In the formula (3), R ₇ , R ₈ , R ₉ and R ₁₀ are each independently an unsubstituted alkyl group or substituted alkyl group having 1 to 30 carbon atoms; an aryl group having 6 to 20 carbon atoms; carbon An unsubstituted alkyl group having 1 to 30 carbon atoms or an aralkyl group in which the substituted alkyl group is substituted with at least one aryl group having 6 to 20 carbon atoms; an aryl group having 6 to 20 carbon atoms having 1 to 1 carbon atoms It represents one selected from the group consisting of 30 unsubstituted alkyl groups or alkylaryl groups substituted with substituted alkyl groups.

  The unsubstituted alkyl group or substituted alkyl group may be linear, branched or cyclic.

  In the above unsubstituted alkyl group, aryl group, aralkyl group, and alkylaryl group, a hydrogen atom may be substituted with a halogen.

  n represents an integer of 1 to 3.

  Y represents a hydroxyl group or any acid residue selected from the group consisting of carboxylic acids having 1 to 20 carbon atoms, hydrogen acids, oxo acid inorganic thioacids, and organic thioacids having 1 to 20 carbon atoms.

  The quaternary ammonium compound is not particularly limited. For example, 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 , Tripropylbenzylammonium, tri-n-butylbenzylammonium, trimethylphenylammonium, triethylphenylammonium, trimethyl-2-oxyethylammonium, monomethyltrihydroxyethylammonium, monoethyltrihydroxyethylammonium, okdadecyltri (2-hydroxy And hydroxides such as ethyl) ammonium and tetrakis (hydroxyethyl) ammonium.

  Other examples of quaternary ammonium compounds include hydrogenates other than halogenated compounds such as hydrogen azide; sulfuric acid, nitric acid, phosphoric acid, carbonic acid, boric acid, chloric acid, iodic acid, silicic acid, perchloric acid Oxo acid salts such as chlorous 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 And carboxylates such as caproic acid, caprylic acid, capric acid, benzoic acid and oxalic acid.

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 such carboxylic acids, formic acid, acetic acid and propionic acid are more preferable.

  The said quaternary ammonium compound may be used individually by 1 type, and may be used in combination of 2 or more type.

  The addition amount of the quaternary ammonium compound is 0.05 to 50 mass ppm in terms of the amount of nitrogen derived from the quaternary ammonium compound represented by the following formula (i) with respect to the crude polymer. Is preferred.

Addition amount of quaternary ammonium compound = P × 14 / Q (i)
In said formula (i), P represents the density | concentration (mass ppm) with respect to the crude polymer of a quaternary ammonium compound, "14" is the atomic weight of nitrogen, Q represents the molecular weight of a quaternary ammonium compound.

  A decomposition removing agent such as a quaternary ammonium compound may be added in advance before the crude polymer is melted, or may be added to the melted crude polymer.

  The decomposition / removal agent may be a combination of ammonia, triethylamine and boric acid compounds, which are known decomposition / removal agents, and a quaternary ammonium compound.

<Additives>
The oxymethylene resin composition used to form the polyoxymethylene slide part of this embodiment contains a fatty acid ester (B) described later as an additive. Moreover, the other additive (C) may be included. Thereby, productivity, operability, and durability can be improved.

(Fatty acid ester (B))
The fatty acid ester (B) used in the present embodiment refers to a compound in which a hydroxyl group of an aliphatic alcohol and a carboxyl group of a fatty acid are ester-bonded.

  The term “aliphatic alcohol” as used herein refers to a compound having a form in which a hydrogen atom of an aliphatic hydrocarbon is substituted with a hydroxyl group. For example, monohydric, divalent and higher polyhydric alcohols depending on the number of hydroxyl groups, saturated alcohols and double bonds due to intramolecular bonds, unsaturated alcohols having triple bonds, and carbon atoms to which hydroxyl groups are bonded. There are monoalcohols, secondary alcohols, and tertiary alcohols. Specifically, methyl alcohol, ethyl alcohol, propyl alcohol, n-butyl alcohol, isobutyl alcohol, tert-butyl alcohol, n-amyl alcohol, 2-pentanol, n-peptyl alcohol, n-octyl alcohol, n- Saturated / unsaturated monoalcohols such as nonyl alcohol, lauryl alcohol, myristyl alcohol, cetyl alcohol, vinyl alcohol, allyl alcohol, crotyl alcohol, methyl vinyl carbinol, allyl carbinol, ethylene glycol, propylene glycol, trimethylene glycol, 1 , 4-butanediol, β-butylene glycol, 2,4-pentanediol, 2-methyl-2,4-butanediol, γ-pentylene glycol, 1,4-hexanediol 2,5-hexanediol, pentamethylene glycol, hexamethylene glycol, glycerin, 1,2,3-butanetriol, 1,2,3-pentanetriol, 2,3,4-hexanetriol, 2-methyl-2 -Oxymethyl-1,3-propanediol, 2-isopropyl-2-oxymethyl-1,3-propanediol, trimethylolpropane, erythritol, 1,2,3,4-pentanetetrol, adnit, alit, etc. Examples include aliphatic polyhydric alcohols. Among these, an aliphatic saturated hydrocarbon alcohol having 8 to 18 carbon atoms is preferable.

  The fatty acid here is a compound in a form in which a part of the aliphatic hydrocarbon is substituted with a carboxyl group. For example, saturated fatty acid (saturated aliphatic monocarboxylic acid, saturated aliphatic dicarboxylic acid, saturated aliphatic tricarboxylic acid, or a branched one more than that), unsaturated fatty acid.

  Specific examples of monocarboxylic acids include formic acid, acetic acid, propionic acid, butyric acid, isobutyric acid, valeric acid, isovaleric acid, pivalic acid, caproic acid, octanoic acid, decanoic acid, lauric acid, myristic acid, palmitic acid, stearic acid Acid, arachidic acid, behenic acid, lignoceric acid and the like can be mentioned.

  Specific examples of the dicarboxylic acid include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid and the like. Examples of the unsaturated fatty acid include acrylic acid, propiolic acid, methacrylic acid, crotonic acid, isocrotonic acid, oleic acid, ricinolenic acid, fumaric acid, maleic acid and the like. Among these, an aliphatic hydrocarbon fatty acid having 4 to 18 carbon atoms is preferable.

  Examples of the fatty acid ester (B) used in this embodiment include didodecyl adipate, ethylene glycol distearate, cetyl myristate, diisodecyl adipate, and ethylene glycol diacetate.

  Two or more types of the fatty acid ester (B) composed of the aliphatic alcohol and the aliphatic carboxylic acid may be added.

  The content (addition amount) of the total fatty acid ester (B) is 0.5 to 2.5% by mass, and further 0.6 to 2.0% by mass with respect to the oxymethylene resin composition. Is preferred. By making it into this range, it is possible to improve the productivity, operability and durability of the slide parts.

  Moreover, it is preferable that fatty acid ester (B) is solid at normal temperature. Examples of the fatty acid ester (B) that is solid at room temperature include didodecyl adipate, ethylene glycol distearate, cetyl myristate, and the like. When the fatty acid ester (B) that is solid at room temperature is used, the productivity of the polyoxymethylene slide parts can be maintained high.

  Furthermore, the fatty acid ester is preferably a diester. Examples of the fatty acid diester include didodecyl adipate, ethylene glycol distearate, diisodecyl adipate, ethylene glycol diacetate, and the like. When the fatty acid diester is used, durability of the polyoxymethylene slide part can be improved.

(Other additives (C))
The oxymethylene resin composition used in the present embodiment may contain other conventionally known additives (C) as long as the object of the present embodiment is not impaired.

  Other additives (C) include, for example, antioxidants, heat stabilizers, formaldehyde and formic acid scavengers, weathering (light) agents, lubricants, various inorganic and organic fillers, other thermoplastic resins, softeners, Examples include crystal nucleating agents, mold release agents, and appearance improving agents such as pigments and dyes.

  The content of the additive (C) in the oxymethylene resin composition is preferably 9.5% by mass or less, more preferably 3.4% by mass or less, and preferably 2% by mass or less. Further preferred.

(Method for producing oxymethylene resin composition)
The oxymethylene resin composition is a component constituting the polyoxymethylene slide part of the present embodiment, and contains polyoxymethylene (A) and fatty acid ester (B) as described above, and further if necessary. It contains the other additive (C).

  Below, the manufacturing method of the oxymethylene resin composition containing all the polyoxymethylene (A), fatty acid ester (B), and another additive (C) is demonstrated exemplarily.

  Mixing of the above polyoxymethylene (A), fatty acid ester (B), and other additives (C) adds the components (B) and (C) during granulation of polyoxymethylene (A). Alternatively, it may be carried out by melt-kneading.

  Moreover, after granulating (A) component, after newly mixing (A) component-(C) component using a Henschel mixer, a tumbler, and a V-shaped blender, a kneader, a roll mill, a single screw extruder, two An oxymethylene resin composition can also be obtained by melt-kneading using a screw extruder or a multi-screw extruder.

  When granulated pellets are used, the dispersibility may be enhanced using an additive. Examples of such an additive include aliphatic hydrocarbons and aromatic hydrocarbons, modified products thereof and mixtures thereof, and fatty acid esters of polyols.

  Moreover, in order to improve the dispersibility of the component (B) and the component (C) with respect to the polyoxymethylene (A), after pulverizing a part or all of the pellets of the polyoxymethylene (A) to be mixed, You may melt-mix.

  It is preferable that the temperature of the said melt mixing is 180-230 degreeC. Furthermore, from the viewpoint of maintaining the quality and working environment, it is preferable to perform deaeration by replacement with an inert gas or single-stage and multistage vents.

(Physical properties of oxymethylene resin composition)
The melt flow rate (MFR) (ASTM 1238, temperature 190 ° C.) of the oxymethylene resin composition used in the present embodiment is preferably 2 to 8 g / 10 minutes, and more preferably 3 to 7 g / 10 minutes. preferable. Depending on the influence of the addition of the fatty acid ester (B) and other additives (C) on the MFR of the oxymethylene resin composition, the chain transfer agent described above is converted into 0.02 to 0 in terms of 1 mol of formaldehyde. It is preferable to polymerize polyoxymethylene (A) by adding 0.08 mol%. By setting the MFR within the above range, the productivity of the slide parts made of polyoxymethylene tends to be maintained, and the operability and durability tend to be improved.

[Method for producing member (I)]
The member (I) used in this embodiment can be obtained, for example, by molding the oxymethylene resin composition described above.

  As a manufacturing method of member (I) used for this embodiment, the various well-known shaping | molding methods using the conventional oxymethylene resin composition used as a raw material are mentioned.

  The molding method is not particularly limited. For example, extrusion molding, injection molding, vacuum molding, blow molding, injection compression molding, decorative molding, multicolor molding, gas assist injection molding, firing injection molding, low pressure molding, super molding, etc. It can be molded by any one of molding methods such as thin-wall injection molding (ultra-high speed injection molding) and in-mold composite molding (insert molding, outsert molding).

  In particular, from the viewpoint of productivity, extrusion molding, injection molding, injection compression molding, or multicolor molding in which different materials are combined and in-mold composite molding are preferable.

  As the molding conditions, recommended conditions under which polyoxymethylene is usually molded are used. For example, it is preferable to perform molding at a resin temperature of 180 to 230 ° C. and a mold temperature of 60 to 90 ° C.

[Partner material (II)]
The slide component made of polyoxymethylene of the present embodiment includes a counterpart material (II) in contact with the member (I) described above.

  The counterpart material (II) used in the present embodiment refers to a material that faces the member (I) when sliding.

  The counterpart material (II) used in the present embodiment has a Rockwell hardness (M scale) of 50 to 110, preferably 55 to 105. The slide component including the counterpart material (II) having such Rockwell hardness is excellent in operability and durability.

  In this embodiment, the Rockwell hardness (M scale) is a value measured by the method described in the examples described later.

  Further, the counterpart material (II) used in the present embodiment is formed using a resin other than the polyoxymethylene resin. Examples of resins other than polyoxymethylene resins include polyamide resins, polypropylene resins, polystyrene resins, nitrile resins, polyphenylene sulfide resins, polyphenylene ether resins, and other resins containing fillers.

  Among these, a polyamide-based resin is preferable from the viewpoint of durability. Examples of the polyamide resin include polyamide 6, polyamide 11, polyamide 12, polyamide 66, polyamide 610, polyamide 6T, polyamide 6I, polyamide 9T, polyamide M5T, polyamide 612, and aramid. The polyamide-based resin used in the present embodiment includes a resin that can form a counterpart material within a specified Rockwell hardness range, and that is obtained by adding a filler, a flexible material, or the like to the polyamide-based resin.

[Manufacturing method of counterpart material (II)]
As a manufacturing method of member (II) used for this embodiment, the various well-known shaping | molding methods using resin other than the polyoxymethylene resin mentioned above used as a raw material are mentioned.

  The molding method is not particularly limited. For example, extrusion molding, injection molding, vacuum molding, blow molding, injection compression molding, decorative molding, multicolor molding, gas assist injection molding, firing injection molding, low pressure molding, super molding, etc. It can be molded by any one of molding methods such as thin-wall injection molding (ultra-high speed injection molding) and in-mold composite molding (insert molding, outsert molding).

  In particular, from the viewpoint of productivity, extrusion molding, injection molding, injection compression molding, or multicolor molding / in-mold composite molding in which different materials are combined is preferable.

  As the molding conditions, recommended conditions for molding a resin other than the polyoxymethylene resin described above are usually used. For example, in the case of a thermoplastic resin, the resin temperature is 10 ° C. or more from the melting point or softening point, and in the range of 10 ° C. or less from the decomposition temperature, and in the case of a thermosetting resin, molding is performed at a curing temperature and a curing time according to the curing agent. Do.

[Usage of Polyoxymethylene Slide Parts]
The slide part made of polyoxymethylene of the present embodiment may be the entire slide part of the apparatus or a part including the slide surface.

  The polyoxymethylene slide part of the present embodiment may have a different material insert and / or a joint with a different material for the purpose of improving workability and functionality. The polyoxymethylene slide part of the present embodiment is formed into a complicated shape or post-processed because the above-described oxymethylene resin composition has excellent productivity and is also excellent in workability. And the operability and durability can be further improved. Further, the surface state of the polyoxymethylene slide part of the present embodiment may be smooth or subjected to various embossing processes.

  The polyoxymethylene slide part of the present embodiment is preferably a slide part used at a steady sliding surface pressure of 20 to 150 MPa between the member (I) and the counterpart material (II). A slide part used at 40 to 120 MPa is preferable.

  In addition, the polyoxymethylene slide part of this embodiment is a slide part that is used at a steady sliding linear velocity of 0.08 to 2.3 m / sec between the above-described member (I) and the counterpart material (II). Preferably, it is a slide part used at 0.1 to 2.0 m / sec. The use of the polyoxymethylene slide component of the present embodiment at the preferred sliding surface pressure and / or sliding linear velocity described above can improve the operability and durability. In the present embodiment, the sliding surface pressure refers to the maximum load per unit area when the member (I) is in pressure contact with the opposing material (II) that is constantly opposed.

  The slide part made of polyoxymethylene of the present embodiment is a contact form when the contact between the member (I) and the counterpart material (II) is a surface or a surface, or a case where the sliding surface is not constant but contacts discontinuously It is preferable to be used in the contact form. It is preferable that the movement of the member (I) or the counterpart material (II) is intermittent or intermittent. As a result, excellent operability and durability can be improved.

  In addition, the slide part made of polyoxymethylene according to the present embodiment can change the sliding speed by changing the sliding surface pressure, changing the shape of the sliding surface, the member (I) or the counterpart material (II). Can be determined.

  The example of the specific form of the polyoxymethylene slide part of this embodiment is shown in FIGS. The member (I) may be either (x) or (y) in FIGS.

  Specific applications of slide parts made of polyoxymethylene include washers, spacers, bushes, rotors, pads, swivels, rollers, and parts thereof used in electrical equipment, automotive parts and other various mechanical parts. Is mentioned.

[How to use slide parts made of polyoxymethylene]
The method of using the polyoxymethylene slide part of the present embodiment uses the above-described polyoxymethylene slide part.

  The method of using the polyoxymethylene slide component of the present embodiment includes a member (I) formed using the above-described oxymethylene resin composition, and a counterpart (II) in contact with the member (I). It is the usage method using components, Comprising: It is preferable that the steady sliding surface pressure of member (I) and the other party material (II) is 20-150 MPa, Furthermore, it is preferable that it is 40-120 MPa.

  Further, the method of using the polyoxymethylene slide part of the present embodiment includes a member (I) formed using the above-described oxymethylene resin composition and a counterpart material (II) in contact with the member (I). It is preferable that the steady sliding linear velocity between the member (I) and the counterpart material (II) is 0.08 to 2.3 m / sec, and more preferably 0. It is preferable that it is 1-2.0 m / sec.

  As for the method for using the polyoxymethylene slide part, it is preferable that the above-mentioned polyoxymethylene slide part operates regularly and intermittently.

  Hereinafter, although a specific Example and a comparative example with this are given and demonstrated, this embodiment is not limited to the following Examples.

  First, the oxymethylene resin composition (P) and the counterpart material (II) that form the member (I) included in the slide part in Examples and Comparative Examples will be described.

[Oxymethylene resin composition (P) forming member (I)]
As raw materials for preparing the oxymethylene resin composition (P), the following polyoxymethylene (A) and fatty acid ester (B) were used.

(raw materials)
<Polyoxymethylene (A)>
As polyoxymethylene (A), polyoxymethylene homopolymer and polyoxymethylene copolymer obtained by the following procedure were used.

-(A-1) Polyoxymethylene homopolymer The polyoxymethylene homopolymer was prepared as follows.

  A jacketed 5 L tank polymerization vessel 1 equipped with a stirrer was filled with 2 L of n-hexane and provided with a circulation line (inner diameter: 6 mm, length: 2.5 m). The n-hexane was circulated at 20 L / hr by a pump. 200 g / hr of dehydrated formaldehyde gas was directly supplied to this circulation line. Further, a catalyst (dimethyl distearyl ammonium acetate) was supplied to a circulation line immediately before the reactor. Furthermore, a chain transfer agent (acetic anhydride) is added to the hexane supplied to compensate for the decrease in the polymerization slurry sent to the next step, and the adjustment is performed within the range of 0.13 to 0.52 g / hr. Polymerization was carried out at 58 ° C. while feeding to a slurry to obtain a polymerization slurry containing a crude polymer. The polymerization catalyst and chain transfer agent used were adjusted according to the final product composition.

  Stabilization was performed by reacting the obtained polymerization slurry in a 1: 1 mixture of hexane and acetic anhydride at 140 ° C. for 2 hours and acetylating the molecular ends. The polymer after the reaction was collected by filtration, depressurized to 2 mmHg or less, and dried for 3 hours with a vacuum dryer set at 80 ° C. to obtain a polyoxymethylene homopolymer powder.

  Furthermore, 100 parts by mass of this powder, 0.2 parts by mass of Irganox 245 (manufactured by Ciba Specialty Chemicals Co., Ltd.) and 0.2 parts by mass of H-3 (manufactured by Asahi Kasei Finechem Co., Ltd.) as stabilizers Mix for 1 minute with a Henschel mixer. Thereafter, the obtained mixture was adjusted to a screw rotation speed of 100 rpm with a screw-type twin screw extruder with a vent set to 200 ° C. (BT-30, L / D = 44 manufactured by Plastic Industry Co., Ltd.) at 24 amps. The mixture was melt-kneaded to obtain polyoxymethylene homopolymer pellets. From raw material input to pellet collection, the operation was performed while avoiding oxygen contamination as much as possible.

-(A-2) Polyoxymethylene copolymer The polyoxymethylene copolymer was prepared as follows.

  First, the polymerization process was performed as follows.

  A self-cleaning type biaxial paddle type continuous mixing reactor with a jacket through which a heat medium can pass (screw diameter 3 inches, length ratio to diameter (L / D) = 10) was adjusted to 80 ° C. Trioxane as the main monomer, 3750 g / hr, 1,3-dioxolane as the comonomer, 25-150 g / hr, and methylal as the chain transfer agent (both used for impurities reduction treatment) 2.0-8. Adjustment was made in the range of 0.0 g / hr, and the mixture was continuously fed to the continuous mixing reactor.

In addition, a 1% by mass cyclohexane solution of boron trifluoride di-n-butyl etherate as a polymerization catalyst is mixed continuously so that the catalyst is 2.0 × 10 ⁻⁵ mol per 1 mol of trioxane. Polymerization was performed by adding to a machine to obtain polymerized flakes. The polymerization catalyst, chain transfer agent and comonomer used were prepared for each composition as the final product.

  After pulverizing the obtained polymerization flakes, the pulverized product was put into a 1% aqueous solution of triethylamine and stirred to deactivate the polymerization catalyst. Thereafter, a 1% aqueous solution of triethylamine containing polymer flakes was sequentially filtered, washed and dried to obtain a crude polymer.

  Equivalent to an amount of 20 ppm when triethyl (2-hydroxyethyl) ammonium formate is converted to an amount of nitrogen using the following formula (i) as a quaternary ammonium compound with respect to 1 part by mass of the obtained crude polymer. Was added and mixed uniformly, followed by drying at 120 ° C. for 3 hours to obtain a dry polymer.

Addition amount of quaternary ammonium compound = P × 14 / Q (i)
(In formula (i), P represents the concentration (mass ppm) of the quaternary ammonium compound relative to the crude polymer, “14” represents the atomic weight of nitrogen, and Q represents the molecular weight of the quaternary ammonium compound.)
Next, the terminal stabilization and granulation process were implemented using the obtained dry polymer.

  The obtained dry polymer is added to the front part of a screw-type twin screw extruder with a vent (Plastic Industry Co., Ltd., BT-30, L / D = 44, set temperature 200 ° C., rotation speed 80 rpm), and further dried. 0.5 parts by mass of water was added to 100 parts by mass of the polymer. The average residence time was set to 1 minute, and vacuum degassing was performed while stabilizing the polymer ends.

  Next, with respect to 100 parts by mass of the dried polymer, 0.2 parts by mass of Irganox 245 (manufactured by Ciba Specialty Chemicals Co., Ltd.) and H-3 (manufactured by Asahi Kasei Finechem Co., Ltd.) 0.2 as stabilizers. Part by mass was previously mixed with a Henschel mixer for 1 minute. The obtained mixture was added from the side feeder in the latter part of the above twin screw extruder and a screw type twin screw extruder with a vent set to 200 ° C. (BT-30, L / D manufactured by Plastic Industry Co., Ltd.) = 44), the screw speed was 100 rpm, and melt kneading was performed at 24 amps to obtain polyoxymethylene copolymer pellets. From raw material input to pellet collection, the operation was performed while avoiding oxygen contamination as much as possible.

  The ratio of the oxyalkylene component b to the oxymethylene component a (100 mol%) (hereinafter also referred to as “b / a”) in the three types of oxymethylene copolymers obtained by adjusting the comonomer is shown in Table 1 below. Here, (b / a) was obtained as follows.

The obtained polyoxymethylene copolymer was dissolved in a solvent, hexafluoroisopropanol (HFIP) -d ₂ (D conversion rate 97%, Wako Pure Chemicals 98% assay) over 24 hours, thereby polyoxymethylene. A 1.5% by weight solution of the copolymer was prepared.

Using a 1.5% by mass solution of the above polyoxymethylene copolymer as a specimen, using a JEOL-400 nuclear magnetic resonance spectrometer ( ¹ H: 400 MHz), under conditions of 55 ° C. and 500 accumulations, the oxymethylene component a and The attribution peaks with the oxyalkylene component b excluding the component a were integrated. From the integrated value thus obtained, the ratio of the oxyalkylene component b to the oxymethylene component a (100 mol%) was determined.

<Fatty acid ester (B)>
The following (B-1) to (B-5) were used as the fatty acid ester (B).
(B-1): didodecyl adipate (made by Kitahiro Chemical Co., Ltd., solid at room temperature)
(B-2): Ethylene glycol distearate (made by Kitahiro Chemical Co., Ltd., solid at room temperature)
(B-3): Cetyl myristate (Nippon Yushi Co., Ltd., solid at room temperature)
(B-4): Diisodecyl adipate (manufactured by Daihachi Chemical Industry Co., Ltd., liquid at normal temperature)
(B-5): Ethylene glycol diacetate (Wako Chemical Co., Ltd., liquid at normal temperature)
(Preparation of oxymethylene resin composition (P))
Said raw material (A) and (B) were mix | blended according to the composition shown in following Table 1, and it mixed uniformly using the Henschel mixer. The obtained mixture was melt-mixed using a screw-type twin screw extruder with a vent (Plastic Industry Co., Ltd., BT-30, L / D = 44, set temperature 200 ° C., rotation speed 80 rpm), and granulation was performed. Then, pellets of the oxymethylene resin compositions (P1) to (P16) were obtained.

  The melt flow rate (MFR) of the oxymethylene resin compositions (P1) to (P16) is shown in Table 1 below. Adjustment of MFR in oxymethylene resin composition (P1)-(P16) was performed by controlling the addition amount of the chain transfer agent and fatty acid ester (B) at the time of preparing the said raw material (A). Here, MFR was determined as follows.

  About the pellet of the obtained oxymethylene resin composition (P1)-(P16), the melt flow rate (ASTM 1238, temperature 190 degreeC) was measured using the melt indexer (Toyo Seiki Co., Ltd. product, F-W01). .

The productivity of the oxymethylene resin composition pellets was evaluated by the following method. The evaluation results are shown in Tables 2-4.

<Productivity evaluation of oxymethylene resin composition>
The productivity evaluation of the oxymethylene resin composition was carried out by adjusting the average granulation amount per unit time of the oxymethylene resin composition when the granulation was carried out by adjusting the extruder torque to be constant at 25 amperes. It was performed comprehensively according to the condition, appearance and odor of the pellets.

  As evaluation criteria, it was defined as follows in comparison with the evaluation of productivity when the oxymethylene resin composition P1 not containing a fatty acid ester was passed through an extruder.

  Compared with the productivity evaluation of the oxymethylene resin composition P1 containing no fatty acid ester, ○ is good, ◇ is the same level, △ is slightly reduced, × is clearly reduced As a result, productivity evaluation of each oxymethylene resin composition was performed.

  In addition, said "good" means the state where the increase in the average granulation amount per unit time was 10% or more when compared with the oxymethylene resin composition P1.

  The above “slightly reduced” means that the average granulated amount per unit time is within 20% to 40% when compared with the oxymethylene resin composition P1, and the resulting strand is stable without blistering or breaking. The pellets thus obtained can be wound up, and the resulting pellets have a slight facet and have an odor but do not deteriorate the workability.

  The above “obviously reduced” means that when compared with the oxymethylene resin composition P1, a decrease in average granulation amount per unit time is larger than 40%, or a biting defect or strand breakage occurs. This is the case where the removal has become unstable, or the appearance (color or shape) of the pellet is bad, or the odor of the pellet is strong, which affects workability.

[Resin forming the counterpart material (II)]
The following resins were used as the resin for forming the counterpart material (II).

(B-1): Polyamide 66 (PA66) (1402S manufactured by Asahi Kasei Chemicals Corporation)
(B-2): Impact-resistant polystyrene (HIPS) (H0130 manufactured by PS Japan Co., Ltd.)
(B-3): Acrylonitrile-styrene copolymer (AS) (709, manufactured by Asahi Kasei Chemicals Corporation)
(B-4): Polyoxymethylene resin (POM) (C4520 manufactured by Asahi Kasei Chemicals Corporation)
(B-5): Polyethylene (PE) (M7620 manufactured by Asahi Kasei Chemicals Corporation)
(B-6): Epoxy resin (EP) (Adeka Co., Ltd. 4100 / curing agent EH101)
[Formation of mating material (II)]
Using the resins (b-1) to (b-6) as the counterpart material (II), the counterpart materials (II-1) to (II-6) were formed as follows.

-Formation of counterpart material (II-1) Using the resin (b-1), the counterpart material (II-1) was formed by a heat press as follows. The heating press was carried out using a heating press (manufactured by Sansho Industry Co., Ltd., two-stage heater press) at a press temperature of 280 ° C., a press pressure of 20 MPa, and a press time of 15 seconds. After the heating press, the plate was cooled at 80 ° C. for 45 seconds, and the obtained flat plate (thickness 3 mm) was used as the counterpart material (II-1). The counterpart material (II-1) had a Rockwell hardness (M scale) of 80.

  In this example, the Rockwell hardness (M scale) was measured using a hardness meter (ATK-F3000, manufactured by Akashi Seisakusho Co., Ltd.) by stacking two flat plates obtained by the heating press.

-Formation of counterpart material (II-2) Using the resin (b-2), except that the press temperature was 210 ° C and the cooling temperature after press was 40 ° C, the same as the formation of the counterpart material (II-1) Thus, a counterpart material (II-2) was obtained. The counterpart material (II-2) had a Rockwell hardness (M scale) of 60.

-Formation of counterpart material (II-3) Using the resin (b-3), except that the press temperature was 210 ° C and the cooling temperature after press was 40 ° C, the same as the formation of the counterpart material (II-1) Thus, a counterpart material (II-3) was obtained. The Rockwell hardness (M scale) of the counterpart material (II-3) was 95.

-Formation of counterpart material (II-4) Using the resin (b-4), except that the press temperature was 200 ° C and the cooling temperature after press was 40 ° C, the same as the formation of the counterpart material (II-1) Thus, a counterpart material (II-4) was obtained. The Rockwell hardness (M scale) of the counterpart material (II-4) was 80.

-Formation of mating material (II-5) Using the resin (b-5), except that the pressing temperature was 200 ° C and the cooling temperature after pressing was 40 ° C, the same as the mating material (II-1). Thus, a counterpart material (II-5) was obtained. The counterpart material (II-5) had a Rockwell hardness (M scale) of 40.

-Formation of counterpart material (II-6) The above-mentioned resin (b-6) was used except that the press temperature was 150 ° C, the press time was 10 hours, and the cooling temperature after press was 80 ° C. ) To obtain a counterpart material (II-6). The Rockwell hardness (M scale) of the counterpart material (II-6) was 115.

[Example 1]
As a member (I) formed using the oxymethylene resin composition, a slide pin (Ia) is produced as follows, and the following guide part (IIb) is used as a counterpart material (II) in contact with the member (I). It produced as follows.

(Production of slide pin (Ia))
Using the oxymethylene resin composition (P2) prepared above, a slide pin (Ia) was produced by injection molding as follows.

  The injection molding was performed using an injection molding machine (TI-30G, manufactured by Toyo Machine Metal Co., Ltd.) with a cylinder temperature of 200 ° C. and a mold temperature of 80 ° C. as a guide.

  As shown in FIG. 4C, the dimensions of the slide pin (Ia) were 5 mm in diameter, 5 mm in width, and 15 mm in length of the slide pin.

(Quality evaluation of slide pin (Ia))
The quality evaluation of the slide pin (Ia) produced using the oxymethylene resin composition was comprehensively performed by visually checking the appearance (silver, flow mark, etc.) and coloring of the molded product.

  The evaluation criteria are ○ when the mold transferability is good and the appearance such as smoothness and glossiness is good, ○ the case equivalent to Comparative Example 1 that does not contain fatty acid ester, and some defects such as silver and flow mark The evaluation was made with Δ when the defect was confirmed, and x when the defect was clearly confirmed on the sliding surface. Evaluation took the average of five of the produced slide pins (Ia).

(Production of guide part (IIb))
A strip of 25 mm × 30 mm was cut out from the formed counterpart material (II-1), and the strip was fixed to a SUS jig of a slide component evaluation device described later to be a guide portion (IIb).

(Production of slide parts)
Using the slide pin (Ia) and the guide part (IIb) produced as described above, a slide part having a configuration as shown in FIG. 4 (a) was produced. The slide part was evaluated as follows.

(Evaluation of productivity of slide parts)
The evaluation of the productivity of the slide part was performed based on the productivity of the oxymethylene resin composition described above and the quality evaluation of the slide pin (Ia) described above.

(Evaluation of operability and durability of slide parts)
The evaluation of the operability and durability of the slide part was performed using a slide part evaluation apparatus described later. The sliding surface pressure between the slide pin (Ia) and the guide part (IIb) during the evaluation is 80 MPa, and the sliding linear velocity between the slide pin (Ia) and the guide part (IIb) is 1.0 m. Per second. In this example, the sliding surface pressure was measured with an existing pressure-sensitive paper (manufactured by Fuji Film Co., Ltd., prescale) before starting evaluation of the slide parts. The sliding linear velocity was measured with a tachometer (manufactured by Ono Sokki Co., Ltd., HT5500).

[Slide parts evaluation system]
4A to 4C show a slide part evaluation apparatus used for evaluating the operability and durability of the slide part.

  FIG. 4A is a schematic diagram of the slide part evaluation apparatus. As shown to Fig.4 (a), this slide component evaluation apparatus was equipped with the slide pin (Ia) and the guide part (IIb). A load was applied from the upper part of the slide pin (Ia), and the guide part (IIb) was reciprocated in the longitudinal direction. FIG. 4B shows a front view and dimensions of the guide portion (IIb), and FIG. 4C shows a front view and dimensions of the slide pin (a).

  For the evaluation of slide parts, a reciprocating tester (AFT-15MS manufactured by Tokyu Seimitsu Co., Ltd.) was improved, and the motor capacity and load resistance were increased so that evaluation under each condition of this example was possible. Using. The measurement conditions were a reciprocating distance of 20 mm, an environmental temperature of 23 ° C., and a humidity of 50%. The load was balanced at the center position of the guide portion (IIb).

(Evaluation criteria for operability and durability)
The operability of the slide parts was evaluated by observing the operation state (sound generation and slide pin movement) when the slide test was started.

  The durability of the slide component was evaluated by observing changes (shape change and appearance) between the slide pin and the guide portion when a long-term slide test was performed. Specifically, the operability and durability of the slide parts were evaluated as follows.

<Operability>
About the generation | occurrence | production of a sound and the movement of a slide pin, when reciprocating 1 to 10 times from the start of a reciprocation test was observed. Each test was performed three times and evaluated by averaging.

  About generation | occurrence | production of a sound, it listened from the distance of 30 cm from the sliding part of a slide component evaluation apparatus, and evaluated as follows by confirming the presence or absence of a sound. When no sound was generated, ◎, when the sound was generated within 5 times, ◯, when a short sound was always confirmed ◇, and when a large continuous sound was always confirmed, ×.

  The evaluation criteria for the movement of the slide pin are as follows: smooth operation from the first time ◎ smooth operation within 5 times, always stick slip confirmed ◇, stick slip always When it was confirmed and the sound was also confirmed, it was set as x.

<Durability>
In addition, the durability of the slide parts was evaluated by observing changes in the shape of the slide pins and the appearance of the slide pins and guide portions when the reciprocating test was performed 100,000 times.

  The observation of the shape change was performed using a microscope (VHX-1000, manufactured by Keyence Corporation). The case where the amount of wear of the slide pin is 20 μm or less is indicated by “◎”, the case where it exceeds 20 μm and 40 μm or less is indicated by “◯”, the case where it exceeds 40 μm and 60 μm or less is indicated by ◇

  Regarding the appearance observation, the evaluation was made with ◎ when it was very good, ◯ when it was very good, ◇ when it was good, and × when it was bad.

  The above “very good” refers to a state in which almost no peeling or the like was observed on the slide pin and the guide part.

  The above “very good” means a state in which the slide pin and / or the guide part is peeled off but almost no powder is generated.

  The above “good” means a state in which the slide pin and / or the guide part are peeled off, but the generation of powder is small.

  The term “defective” refers to a state in which the slide pin and / or the guide part are peeled off and the generation of powder is large.

[Examples 2 to 5 and Comparative Examples 1 and 2]
A slide pin (Ia), a guide part (IIb), and a slide part were produced and evaluated in the same manner as in Example 1 except that the oxymethylene resin composition of the type shown in Table 2 was used. The evaluation results are shown in Table 2. In Comparative Example 2, the slide pin (Ia) was clearly defective on the sliding surface, so no subsequent evaluation was performed.

As shown in Table 2 above, from the evaluation results of Examples 1 to 3 and Comparative Examples 1 and 2, a slide part made of polyoxymethylene using an oxymethylene resin composition containing a fatty acid ester defined in this embodiment, It was found that high productivity can be maintained, and excellent operability and durability. It was found that the slide part using the oxymethylene resin composition not containing the prescribed fatty acid ester in this embodiment is inferior in operability and durability.

  In addition, when an oxymethylene resin composition having a fatty acid ester content higher than specified in the present embodiment is used, surging or strand breakage occurs in the extruder, and further, the polyoxymethylene slide parts are confirmed to be colored and quality. It was found that productivity was lowered.

[Examples 4 and 5 and Comparative Examples 3 to 5]
A slide pin (Ia) and a slide part were produced in the same manner as in Example 2 except that the guide part (IIb) was produced from the counterpart materials (b-2) to (b-6) as shown in Table 2. Each evaluation was conducted. Table 2 shows the evaluation results of Examples 4 and 5 and Comparative Examples 3 to 5.

  As shown in Table 2, from the evaluation results of Examples 2, 4, 5 and Comparative Examples 3 to 5, formed using a resin other than polyoxymethylene resin, and Rockwell hardness (M scale) is 50 to 110. It was found that the slide part using the mating material has excellent operability and durability. Both the sound and the stick slip were confirmed in the operability evaluation of the slide part using the counterpart material formed from polyoxymethylene resin (POM). In addition, slide parts using a mating material softer than the prescribed Rockwell hardness had a change in appearance, such as peeling at the guide part after completion of the slide test, and further generation of dents and powder in the guide part. . In addition, the slide part using the counterpart material harder than the prescribed Rockwell hardness showed a large change in the shape of the slide pin, and further, a part of the slide pin was peeled off. Among the counterpart materials specified in the present embodiment, it has been found that the counterpart material formed from PA 66 is particularly preferable from the balance of operability and durability.

[Examples 6 to 9]
A slide pin (Ia), a guide part (IIb), and a slide part were produced in the same manner as in Example 1 except that the oxymethylene resin composition of the type shown in Table 3 was used, and each evaluation was performed. The evaluation results of Examples 6 to 9 are shown in Table 3.

As shown in Table 3 above, from the evaluation results of Examples 6 to 9, the slide part including the member formed using the oxymethylene resin composition containing the preferred fatty acid ester of the present embodiment maintains high productivity. And was found to have excellent operability and durability. When monoester was used as the fatty acid ester, the operability of the slide part was improved, but the durability of the slide part tended to be less improved. In addition, when diester having a low melting point was used as the fatty acid ester, surging in an extruder, strand breakage, silver, etc. were confirmed in the slide pin, and the productivity tended to decrease.

[Examples 10 to 12]
A slide pin (Ia), a guide part (IIb), and a slide part were produced in the same manner as in Example 1 except that the oxymethylene resin composition of the type shown in Table 3 was used, and each evaluation was performed. The evaluation results of Examples 10 to 12 are shown in Table 3.

  As shown in Table 3 above, from the evaluation results of Examples 10 to 12, the slide part including the member formed using the polyoxymethylene-containing composition in which the preferred comonomer amount of this embodiment is inserted is high. It was found that productivity can be maintained, and excellent operability and durability are achieved. When the amount of inserted comonomer was large, the shape change of the slide pin tended to increase.

[Examples 13 to 16]
A slide pin (Ia), a guide part (IIb), and a slide part were produced in the same manner as in Example 1 except that the oxymethylene resin composition of the type shown in Table 3 was used, and each evaluation was performed. Table 3 shows the evaluation results of Examples 13 to 16.

  As shown in Table 3 above, from the evaluation results of Examples 13 to 16, the slide part including the member formed using the preferred MFR oxymethylene resin composition of the present embodiment can maintain productivity and is excellent. It was found to have excellent operability and durability. When the MFR of the oxymethylene resin composition was low, the productivity showed a tendency to decrease, and when it was high, the part of the guide part tended to peel.

[Examples 17 to 20]
The slide pin is the same as in Example 2 except that the sliding surface pressure between the slide pin (Ia) and the guide portion (IIb) when the operability and durability are evaluated is changed as shown in Table 4. (Ia), a guide part (IIb), and a slide part were produced and evaluated. The evaluation results of Examples 17 to 20 are shown in Table 4.

As shown in Table 4 above, from the evaluation results of Examples 2 and 17 to 20, excellent operability and durability are obtained by using a slide part made of polyoxymethylene within the preferred sliding surface pressure range of this embodiment. It has been found that it exhibits sex. When the sliding surface pressure decreases, the slide pin tends to move less smoothly, and when the sliding surface pressure increases, the sound tends to be generated.

[Examples 21 to 24]
The slide pin (Ia) and the guide portion (IIb) at the time of evaluating operability and durability were changed in the same manner as in Example 2 except that the sliding linear velocity was changed as shown in Table 4. (Ia), a guide part (IIb), and a slide part were produced and evaluated. Table 4 shows the evaluation results of Examples 21 to 24.

  As shown in Table 4 above, from the evaluation results of Examples 2 and 21 to 24, in this embodiment, by using a polyoxymethylene slide part within a preferable sliding linear velocity range, excellent operability and It was found to be durable. When the sliding linear velocity is decreased, the slide pin tends to be unsmooth, and when the sliding linear velocity is increased, noise is generated.

  The present invention relates to one or more slide parts selected from the group consisting of washers, spacers, bushes, rotors, buds, swivels, rollers, etc., and parts thereof in electrical equipment, automobile parts and other various mechanical parts. As an industrial applicability.

Claims (8)

A member (I) formed using the oxymethylene resin composition; and a partner material (II) in contact with the member (I), wherein the member (I) and the partner material (II) are at least partially A sliding part that is used by sliding the member (I) and the counterpart material (II),
In the oxymethylene resin composition, the content of polyoxymethylene (A) is not less than 95 wt%, the content of the fatty acid ester (B) is 0.5 to 2.5 wt%, other additives The content of (C) is 3.4% by mass or less,
It said mating member (II) is formed using a polyamide-based resin, Rockwell hardness (M scale) characteristics and be away Ride component that is 50 to 110. Slide component according to claim 1, wherein the fatty acid ester (B) is a diester. Slide component according to claim 1 or 2, wherein the fatty acid ester (B) is solid at room temperature. The polyoxymethylene (A) is a polyoxymethylene copolymer (A-2) containing 1.35 mol% or less of a comonomer component other than the oxymethylene component with respect to 100 mol% of the oxymethylene component. slide component according to any one of claims 1 to 3. Using features and be away ride part the use of slide component according to any one of claims 1-4. A method of using a slide component comprising a member (I) formed using an oxymethylene resin composition and a counterpart material (II) in contact with the member (I),
Using slide part according to claim 5, stationary sliding surface pressure of the member (I) and partner material and (II) is characterized in that it is a 20～150MPa. A method of using a slide component comprising a member (I) formed using an oxymethylene resin composition and a counterpart material (II) in contact with the member (I),
Using slide part according to claim 5, steady sliding linear velocity member (I) and partner material and (II) is characterized in that it is a 0.08~2.3m / sec. Slide component according to any one of claims 1 to 4, constantly intermittently operated using the features and to Luz ride components to.