JP2017061644A - Resin guide component, polyacetal resin composition for resin guide component, method for producing the same, and method for producing resin guide component - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a guide member having high abrasion resistance under presence of a foreign substance.SOLUTION: A resin guide member includes a rib part. In the resin guide member, a strain amount c(%) is obtained after conducting loading of 75 MPa and unloading from 75 MPa to 15 MPa to a test piece cut out from the rib part, once, and a strain amount d(%) is obtained after conducting loading of 75 MPa and unloading from 75 MPa to 15 MPa to a test piece cut out from the rib part, 50 times. A difference (d-c: residual strain) between the strain amount c(%) and the strain amount d(%) is 0.9 point or less.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a resin guide part, a polyacetal resin composition for a resin guide part, a manufacturing method thereof, and a method of manufacturing a resin guide part.

Resin guide parts are used as a power transmission mechanism and a drive transmission mechanism in a wide range of applications such as window glass, seats, and sunroofs in automobiles. In particular, since resin guide parts are lightweight, replacement with metal guide parts is progressing.
A typical resin guide component is a carrier plate for an automobile window glass. The carrier plate has a structure as illustrated in FIG. It has a function to raise and lower the window glass attached to the carrier plate by fitting and sliding a metal rail-shaped guide mainly on the guide sliding portion (1) and the guide sliding auxiliary portion (2).
Polyacetal resins are characterized by excellent balance of mechanical strength such as flexural modulus and tensile fracture stress, chemical resistance, slidability, and wear resistance, and easy processing. Therefore, polyacetal resin is used as a material for various guide parts such as mechanical parts for automobiles and automobile parts as typical engineering plastics.
In particular, polyacetal resin compositions reinforced with inorganic fillers are used for automotive parts that require high durability.
Here, “durability” means, for example, a long fracture life under a constant stress.

  In the polyacetal resin composition reinforced with the inorganic filler, in order to further improve the durability, the polyacetal resin is usually made high in molecular weight and the end group of the polyacetal resin is controlled.

  Patent Document 1 discloses a polyacetal resin composition containing a polyacetal resin and a fibrous inorganic filler for the purpose of improving durability. Patent Document 1 discloses that durability is improved as the molecular weight of the polyacetal resin is increased.

  Patent Document 2 discloses a polyacetal resin composition containing a glass-based inorganic filler and a polyacetal resin. In order to improve the adhesion at the interface between the glass-based inorganic filler and the polyacetal resin, the inclusion of a terminal hydroxyl group is disclosed. A method of using a plurality of polyacetal resins having different amounts in combination is disclosed.

Patent Document 3 discloses that the use of an ABA type block copolymer containing a polyacetal skeleton improves the adhesion to glass fibers and the like.
In addition, from the viewpoint of improving wear resistance in accordance with the expansion of the application field of polyacetal resin, it has been studied to improve wear resistance by adding ultrahigh molecular weight polyethylene to the resin composition. Yes.

  Patent Document 4 discloses blending a lubricant in order to improve the wear resistance of a polyacetal resin composition containing glass fibers. Patent Document 4 discloses that ultrahigh molecular weight polyethylene is preferable as the lubricant.

Patent Document 5 discloses that a tribology modifier is added to a polyacetal resin composition containing glass fibers for the purpose of improving mechanical strength, wear resistance, and slidability. In particular, it is disclosed that the tribology modifier is preferably ultrahigh molecular weight polyethylene having an average molecular weight of more than 1.0 × 10 ⁶ g / mol.

JP-A-11-181231 JP 2004-359791 A International Publication No. 2001/009213 JP-A-9-272802 Special table 2014-534301 gazette

  In recent years, resin guide parts have been required to have improved mechanical strength, durability, wear resistance, and quietness. In particular, wear resistance in the presence of foreign matter is required for application to automobiles and outdoor applications. In particular, a carrier plate for an automobile window glass is operated in an environment where sand particles, dust, and the like are likely to adhere, so that higher wear resistance is required in the presence of foreign matter.

However, when the molecular weight of the polyacetal resin is increased, the fluidity is lowered and the molding becomes difficult, which causes a deterioration in the quality of the guide parts such as a defective appearance.
In addition, when ultra high molecular weight polyethylene is added to improve wear resistance, chips are easily generated during the production of resin pellets due to dropping off of the ultra high molecular weight polyethylene in the manufacturing process. As a result, an appearance defect may occur, which may cause a decrease in wear resistance.
As described above, the conventional techniques as disclosed in Patent Documents 1 to 5 cannot manufacture a guide component that is excellent in durability, has high mechanical strength, and wear resistance in the presence of foreign matter.

  Therefore, a problem to be solved by the present invention is to provide a guide component having high wear resistance in the presence of foreign matter.

As a result of intensive studies to solve the above-mentioned problems, the present inventors performed loading and unloading of a predetermined value on a test piece cut out from a rib portion of a resin guide part having a rib portion. It has been found that a guide component having a specific amount of distortion (%) later can solve the above problem, and has completed the present invention.
That is, the present invention is as follows.

[1]
A resin guide part having a rib part,
With respect to the test piece cut out from the rib part, a strain amount c (%) after performing a load of 75 MPa and unloading from 75 MPa to 15 MPa once,
The difference (dc: residual strain) from the strain amount d (%) after the load of 75 MPa and the unloading from 75 MPa to 15 MPa were repeated 50 times for the test piece cut out from the rib portion, Resin guide parts with 0.9 points or less.
[2]
A resin guide part having a rib part,
The amount of strain b (%) when a load of 75 MPa is applied once to the test piece cut out from the rib portion, and the amount of strain c (%) after the unloading from 75 MPa to 15 MPa is performed once thereafter. Resin guide parts whose difference (bc: elastic strain) is 2.5 points or less.
[3]
A resin guide part having a rib part,
With respect to the test piece cut out from the rib part, a load of 75 MPa and a strain amount c (%) after performing unloading from 75 MPa to 15 MPa once, and with respect to the test piece cut out from the rib part, 75 MPa The difference between the load and the amount of strain d (%) after repeating unloading from 75 MPa to 15 MPa 50 times (dc: residual strain),
With respect to the test piece cut out from the rib part, the strain amount d (%) after the load of 75 MPa and the unloading from 75 MPa to 15 MPa were repeated 50 times, and the test piece cut out from the rib part, A value ((dc) / (da)) divided by the difference (da) in the strain amount a (%) when the load reaches 15 MPa when the load up to 15 MPa is performed once. : Residual guide component having a residual strain ratio) of 0.50 or less.
[4]
The resin guide component according to any one of [1] to [3], including a polyacetal resin.
[5]
For 100 parts by mass of the polyacetal resin,
The resin guide component according to [4], including 10 to 100 parts by mass of the glass filler.
[6]
When the test piece cut out from the rib portion is pulled and fractured, the surface of the glass-based filler protruding from the fracture surface is covered with a component containing a polyacetal resin having an average thickness of 0.2 μm or more and 3.0 μm or less. [5] The resin guide component according to [5].
[7]
The resin guide part according to [5] or [6], which contains at least one acid as a substance having a function of modifying the surface of the glass filler.
[8]
The resin guide component according to [7], wherein the acid is a carboxylic acid.
[9]
The resin guide component according to any one of [4] to [8], wherein the polyacetal resin includes a block component.
[10]
[9] The resin guide part according to [9], wherein the block component is a hydrogenated polybutadiene component in which both ends are hydroxyalkylated.
[11]
The resin guide component according to any one of [4] to [10], wherein the content of the terminal OH group in the polyacetal resin is 0.006 mol% or more with respect to 1 mol of the oxymethylene unit of the main chain.
[12]
For 100 parts by mass of the polyacetal resin,
The resin guide component according to any one of [4] to [11], further including 0.5 to 8 parts by mass of a polyethylene resin having a weight average molecular weight of 500,000 or less.
[13]
The resin guide component according to [12], wherein the polyethylene resin has a melting point of 115 ° C or lower.
[14]
The abundance of the polyethylene resin in the surface layer within 10 nm of the test piece cut out from the rib part is from the abundance of the polyethylene resin in the surface layer within 10 nm of the surface cut out from the surface layer of the test piece cut out from the rib part from 1,000 μm. The resin guide component according to [12] or [13].
[15]
The resin guide component according to any one of [1] to [14], which is a carrier plate for an automobile window glass.
[16]
[1] to a polyacetal resin composition used for the resin guide part according to any one of [3],
A polyacetal resin composition for resin guide parts, comprising 100 parts by mass of a polyacetal resin and 10 to 100 parts by mass of a glass-based filler.
[17]
For 100 parts by mass of the polyacetal resin,
The polyacetal resin composition for resin guide parts according to [16], further comprising 0.5 parts by mass or more and 8 parts by mass or less of a polyethylene resin having a weight average molecular weight of 500,000 or less.
[18]
The polyacetal resin composition for resin guide parts according to [17], wherein the polyethylene resin has a melting point of 115 ° C or lower.
[19]
The polyacetal resin for resin guide parts according to any one of [16] to [18], which contains at least one acid as a substance having a function of modifying the surface of the glass filler of the glass filler. Composition.
[20]
The polyacetal resin composition for resin guide parts according to [19], wherein the acid is a carboxylic acid.
[21]
The polyacetal resin composition for resin guide parts according to any one of [16] to [20], wherein the polyacetal resin contains a block component.
[22]
The polyacetal resin composition for resin guide parts according to [21], wherein the block component is a hydrogenated polybutadiene component having both ends hydroxyalkylated.
[23]
The polyacetal for resin guide parts according to any one of [16] to [22], wherein the content of the terminal OH group in the polyacetal resin is 0.006 mol% or more with respect to 1 mol of the oxymethylene unit of the main chain. Resin composition.
[24]
[16] to [23], a method for producing a polyacetal resin composition for resin guide parts according to any one of the above,
A step of modifying the surface of the glass-based filler with a substance containing at least one acid and having a function of modifying the surface of the glass-based filler;
Mixing the modified glass-based filler and a polyacetal resin;
The manufacturing method of the polyacetal resin composition for resin guide parts containing this.
[25]
[16] A method for producing a resin guide part, comprising a step of molding the polyacetal resin composition for a resin guide part according to any one of [23].

  According to the present invention, it is possible to provide a guide component having high wear resistance in the presence of foreign matter.

It is a figure showing an example (carrier plate) of a guide component. It is a figure showing the surface which has a rib part in the guide component of FIG. 2 is a load-unloading curve obtained by a compression test in Example 1. FIG. 10 is a load-unloading curve obtained by a compression test in Comparative Example 5.

  Hereinafter, although the form for implementing this invention (henceforth "this embodiment") is demonstrated in detail, this invention is not limited to the following description, In the range of the summary Various modifications can be made.

[Resin guide parts]
(Resin guide component of the first embodiment)
The resin guide component in the first embodiment is
A resin guide part having a rib part,
With respect to the test piece cut out from the rib part, a strain amount c (%) after performing a load of 75 MPa and unloading from 75 MPa to 15 MPa once,
The difference (dc: residual strain) from the strain amount d (%) after the load of 75 MPa and the unloading from 75 MPa to 15 MPa were repeated 50 times for the test piece cut out from the rib portion, 0.9 points or less.

(Resin guide component of the second embodiment)
The resin guide component in the second embodiment is
A resin guide part having a rib part,
The amount of strain b (%) when a load of 75 MPa is applied once to the test piece cut out from the rib portion, and the amount of strain c (%) after the unloading from 75 MPa to 15 MPa is performed once thereafter. Difference (bc: elastic strain) is 2.5 points or less.

(Resin guide component of the third embodiment)
The resin guide component in the third embodiment is
A resin guide part having a rib part,
With respect to the test piece cut out from the rib part, a load of 75 MPa and a strain amount c (%) after performing unloading from 75 MPa to 15 MPa once, and with respect to the test piece cut out from the rib part, 75 MPa The difference between the load and the amount of strain d (%) after repeating unloading from 75 MPa to 15 MPa 50 times (dc: residual strain),
With respect to the test piece cut out from the rib part, the strain amount d (%) after the load of 75 MPa and unloading from 75 MPa to 15 MPa were repeated 50 times for the test piece cut out from the rib part, and the test piece cut out from the rib part, A value ((dc) / (da)) divided by the difference (da) in the strain amount a (%) when the load reaches 15 MPa when the load up to 15 MPa is performed once. : Residual strain ratio) is 0.50 or less.

(Polyacetal resin composition)
The resin guide component of the present embodiment preferably contains a polyacetal resin. Moreover, the resin-made guide component of this embodiment can be obtained by shape | molding the polyacetal resin composition containing the said polyacetal resin, for example.

<Polyacetal resin>
The polyacetal resin composition used for the resin guide part of the present embodiment contains a polyacetal resin.
Polyacetal resins include polyacetal homopolymers, polyacetal copolymers, polyacetal copolymers having a crosslinked structure, homopolymer-based block copolymers having a block component, and copolymer-based block copolymers having a block component.
A polyacetal resin may be used individually by 1 type, or may be used in combination of 2 or more type.

The polyacetal resin is not limited to the following, but for example, a combination of polymers having different molecular weights, a combination of polyacetal copolymers having different comonomer amounts, and the like can be used as appropriate.
In the present embodiment, it is preferable to use a block copolymer containing a block component as the polyacetal resin.
The “block component” refers to each polymer constituting a polyacetal resin and bound in one molecule.

  The polyacetal resin is not limited to the following, but for example, a substance obtained by homopolymerizing a formaldehyde monomer or a cyclic oligomer of formaldehyde such as a trimer (trioxane) or a tetramer (tetraoxane). Polyacetal homopolymer consisting only of the upper oxymethylene unit, formaldehyde monomer or cyclic oligomer of formaldehyde such as trimer (trioxane) and tetramer (tetraoxane), ethylene oxide, propylene oxide, epichlorohydrin, 1,3 -Polyacetal copolymers obtained by copolymerizing glycols such as dioxolane and 1,4-butanediol formal, and cyclic ethers such as cyclic formal of diglycol or cyclic formal.

  As the polyacetal copolymer, a formaldehyde monomer and / or a cyclic oligomer of formaldehyde and a monofunctional glycidyl ether are copolymerized with a branched polyacetal copolymer obtained by copolymerization, and a polyfunctional glycidyl ether. The resulting polyacetal copolymer having a crosslinked structure can also be used.

The polyacetal copolymer may be a block copolymer having different types of block components different from the repeating structural units of the polyacetal.
In the present embodiment, as the block copolymer, an acetal homopolymer or acetal copolymer having at least a block component represented by any one of the following general formulas (1), (2), and (3) (hereinafter, both are combined to form a block) May be described as a copolymer).

In the general formulas (1) and (2), R ₁ and R ₂ each independently represent one selected from the group consisting of a hydrogen atom, an alkyl group, a substituted alkyl group, an aryl group, and a substituted aryl group. The plurality of R ₁ and R ₂ may be the same or different.
R ₃ represents one selected from the group consisting of an alkyl group, a substituted alkyl group, an aryl group, and a substituted aryl group.
m shows the integer of 1-6, and the integer of 1-4 is preferable.
n shows the integer of 1-10000, and the integer of 10-2500 is preferable.

The block component represented by the general formula (1) is a residue obtained by eliminating a hydrogen atom from an alkylene oxide adduct of alcohol. The block component represented by the general formula (2) is an alkylene of a carboxylic acid. It is a residue in which a hydrogen atom is eliminated from an oxide adduct.
The polyacetal homopolymer having a block component represented by the general formula (1) or (2) can be produced, for example, by the method described in JP-A-57-31918.

In the general formula (3), R ₄ represents one selected from the group consisting of a hydrogen atom, an alkyl group, a substituted alkyl group, an aryl group and a substituted aryl group, and a plurality of R ₄ may be the same. May be different.
p represents an integer of 2 to 6, and two p's may be the same or different.
q and r each represent a positive number, and when the sum of q and r is 100 mol%, q is 2 to 100 mol%, r is 0 to 98 mol%, and-(CH (CH ₂ CH ₃ ) CH ₂ ) -units and-(CH ₂ CH ₂ CH ₂ CH ₂ ) -units are present in random or block form, respectively.

The block component represented by any one of the following formulas (1), (2), and (3) is a compound that constitutes a block component having a functional group such as a hydroxyl group at both ends or one end, during the polymerization process of polyacetal. It can be inserted into the polyacetal resin by reacting with the terminal portion of the polyacetal.
The insertion amount of the block component represented by the general formula (1), (2) or (3) in the block copolymer which is a polyacetal resin is not particularly limited. It is preferable that it is 001 mass% or more and 30 mass% or less.
From the viewpoint of obtaining a practically sufficient bending elastic modulus in the resin guide part, the amount of the block component represented by the general formulas (1) to (3) is preferably 30% by mass or less. From the viewpoint of the tensile strength of the part, the insertion amount of the block component is preferably 0.001% by mass or more.
The lower limit of the amount of the block component inserted is more preferably 0.01% by mass, still more preferably 0.1% by mass, and even more preferably 1% by mass.
The upper limit of the amount of the block component inserted is more preferably 15% by mass, still more preferably 10% by mass, and still more preferably 8% by mass.

The molecular weight of the block component in the block copolymer is preferably 10,000 or less from the viewpoint of obtaining a practically sufficient bending elastic modulus in the resin guide part, more preferably 8000 or less, and even more preferably 5000 or less. .
The lower limit of the molecular weight of the block component is not particularly limited, but is preferably 100 or more from the viewpoint of maintaining stable slidability.

The compound that forms the block component in the block copolymer is not limited to the following, but for example, C ₁₈ H ₃₇ O (CH ₂ CH ₂ O) ₄₀ C ₁₈ H ₃₇ , C ₁₁ H ₂₃ CO ₂ (CH _{2 CH 2 O) 30 H,} C 18 H 37 O (CH 2 CH 2 O) 70 H, C 18 H 37 O (CH 2 CH 2 O) 40 H and, both ends hydroxyalkylated hydrogenated polybutadiene is mentioned It is done.
The block copolymer is preferably an ABA type block copolymer as a bonding form.
The ABA type block copolymer is a block copolymer having a block component represented by the general formula (3). Specifically, the polyacetal segment A (hereinafter referred to as A) and both ends are hydroxyalkylated. It means a block copolymer in which the hydrogenated polybutadiene segment B (hereinafter referred to as B) is composed in the order of ABA.

Block component represented by the general formula (1) to (3) may have the following unsaturated bond iodine value 20g-I ₂ / 100g. Although it does not specifically limit as an unsaturated bond, For example, a carbon-carbon double bond is mentioned.
Examples of the polyacetal copolymer having the block component represented by the general formulas (1) to (3) include the polyacetal block copolymer disclosed in International Publication No. 2001/09213, and the method described in the publication. Can be prepared.
By using the ABA type block copolymer described above as the block copolymer, the adhesion to the surface of the glass-based filler described later tends to be improved. As a result, the mechanical strength and wear resistance of the resin guide component of the present embodiment tend to be improved.

The ratio of the block copolymer in the polyacetal resin is preferably 5% by mass or more and 95% by mass or less when the entire polyacetal resin is 100% by mass.
The lower limit value of the ratio of the block copolymer is more preferably 10% by mass, still more preferably 20% by mass, and still more preferably 25% by mass.
The upper limit of the ratio of the block copolymer is more preferably 90% by mass, still more preferably 80% by mass, and still more preferably 75% by mass.
The ratio of the block copolymer in the polyacetal resin can be measured by ¹ H-NMR, ¹³ C-NMR, or the like.

Further, it is preferable to use a polyacetal resin having a terminal OH group content of 0.006 mol% or more with respect to 1 mol of the main chain oxymethylene unit. More preferably, it is 0.007 mol% or more, More preferably, it is 0.008 mol% or more, More preferably, it is 0.01 mol% or more. There is no particular upper limit for the content of the terminal OH group, but it is preferably 1 mol% or less.
The content of the terminal OH group can be measured by an integration ratio in the ¹ H NMR spectrum. As the solvent to be used, deuterated hexafluoroisopropyl alcohol, deuterated chloroform and a mixed solvent thereof are preferable.
By using a polyacetal resin having the above-mentioned block copolymer or terminal OH group content of 0.006 mol% or more, the durability and wear resistance of the resin guide part of this embodiment are improved.

<Glass-based filler>
It is preferable that the polyacetal resin composition used for the resin guide part of the present embodiment includes 10 parts by mass or more and 100 parts by mass or less of the glass-based filler with respect to 100 parts by mass of the polyacetal resin.
When the content of the glass filler is 10 parts by mass or more, mechanical strength and durability are improved. Moreover, when the content of the glass-based filler is 100 parts by mass or less, it is possible to suppress breakage of the glass-based filler due to contact between the glass-based fillers during molding. For this reason, mechanical strength and durability are improved. Furthermore, when the content of the glass-based filler is 100 parts by mass or less, stable extrusion can be performed, appearance defects of the resin guide parts can be suppressed, and wear resistance can be improved.

The lower limit of the content of the glass filler is preferably 12 parts by mass, more preferably 15 parts by mass, still more preferably 20 parts by mass, and even more preferably 25 parts by mass.
The upper limit of the content of the glass-based filler is preferably 90 parts by mass, more preferably 80 parts by mass, still more preferably 75 parts by mass, and even more preferably 70 parts by mass.

The glass-based filler that can be used in the polyacetal resin composition used for the resin guide part of the present embodiment is not limited to the following, but examples thereof include glass fiber, glass beads, and flaky glass. Is mentioned.
Examples of the glass fiber include, but are not limited to, chopped strand glass fiber, milled glass fiber, and glass fiber roving. Among these, chopped strand glass fibers are preferable from the viewpoints of handleability and mechanical strength of guide parts.
A glass type filler may be used individually by 1 type, or may be used in combination of 2 or more type.

The particle size, fiber diameter, fiber length, etc. of the glass-based filler are not particularly limited, and any form of glass-based filler may be used, but the larger the surface area, the greater the contact area with the polyacetal resin. It is preferable because durability and wear resistance of the resin guide parts are improved.
When the glass filler is chopped strand glass fiber, the average fiber diameter is preferably 7 μm or more and 15 μm or less.
When the average fiber diameter of the chopped strand glass fiber is within the above range, the surface of the resin guide component of the present embodiment becomes smooth, and the wear resistance can be improved. In addition, the durability of the resin guide component of the present embodiment can be enhanced, and the die surface can be prevented from being scraped during molding.
The lower limit value of the average fiber diameter of the chopped strand glass fibers is more preferably 8 μm, and even more preferably 9 μm.
The upper limit value of the average fiber diameter is more preferably 14 μm, still more preferably 12 μm.

In this embodiment, the average fiber diameter of the glass filler is obtained after incineration of the resin guide component of this embodiment at a sufficiently high temperature (400 ° C. or higher) to remove the resin component and the organic component. The ash content can be easily measured by observing the ash content with a scanning electron microscope and measuring the diameter. In order to reduce the error, the diameter of at least 100 chopped strand glass fibers is measured, and the average value of the fiber diameters is calculated.
As the glass filler, two or more kinds of glass fibers having different fiber diameters may be blended and used.

The glass filler is preferably treated with a film forming agent and the surface thereof is modified.
The film forming agent may be referred to as a sizing agent.
Examples of the coating forming agent include, but are not limited to, urethane resins, epoxy resins, and copolymer resins having at least one acid component.
Among these, a film forming agent containing a copolymer resin having at least one acid component is preferable.
The copolymer resin having at least one acid component is preferably one in which the acid component is a carboxylic acid, and is not limited to the following, for example, a carboxylic acid-containing unsaturated vinyl monomer and Copolymer containing unsaturated vinyl monomer other than carboxylic acid-containing unsaturated vinyl monomer as a constituent unit, carboxylic acid anhydride-containing unsaturated vinyl monomer, and carboxylic acid anhydride-containing unsaturated vinyl monomer And a copolymer containing an unsaturated vinyl monomer other than a monomer as a constituent unit. Among these, it is more preferable to use a copolymer containing as constituent units a carboxylic acid-containing unsaturated vinyl monomer and an unsaturated vinyl monomer other than the carboxylic acid-containing unsaturated vinyl monomer.
Only one type of film forming agent may be used alone, or two or more types may be used in combination.
Examples of the carboxylic acid-containing unsaturated vinyl monomer include, but are not limited to, acrylic acid, methacrylic acid, fumaric acid, itaconic acid, maleic acid, and the like, and acrylic acid is preferable.
A carboxylic acid containing unsaturated vinyl monomer may be used individually by 1 type, and may be used in combination of 2 or more type.
Examples of the carboxylic acid anhydride-containing unsaturated vinyl monomer include, but are not limited to, maleic acid or itaconic acid anhydride.
The carboxylic acid anhydride-containing unsaturated vinyl monomer may be used alone or in combination of two or more.

By modifying the surface of the glass-based filler with a film forming agent, the adhesive strength at the interface with the polyacetal resin can be increased, and the average thickness of the component containing the polyacetal resin covering the surface of the glass-based filler is increased. Thereby, durability improves. Furthermore, wear during sliding can be suppressed.
Among them, a polyacetal resin containing a block component and / or a polyacetal resin in which the content of terminal OH groups is 0.006 mol% or more with respect to 1 mol of the main chain oxymethylene unit, and a glass-based filler modified with a film forming agent By combining these, durability and wear resistance are dramatically improved.

In the present embodiment, the glass-based filler may be surface-modified with a coupling agent.
A coupling agent is not specifically limited, A well-known thing can be used.
Examples of the coupling agent include, but are not limited to, organic silane compounds, organic titanate compounds, organic aluminate compounds, and the like.
A coupling agent may be used individually by 1 type, or may be used in combination of 2 or more type.

Examples of the organic silane compound include, but are not limited to, vinyltriethoxysilane, vinyl-tris- (2-methoxyethoxy) silane, γ-methacryloxypropylmethoxysilane, and γ-aminopropyltrimethoxy. Silane, γ-aminopropyltriethoxysilane, N-β- (aminoethyl) -γ-aminopropyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltriethoxysilane, γ-glycidoxypropylmethoxysilane , Γ-mercaptopropyltrimethoxysilane and the like.
Among them, vinyltriethoxysilane, vinyl-tris- (2-methoxyethoxy) silane, γ-methacryloxypropylmethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, and γ-glycidoxy Propylmethoxysilane is preferred. Vinyltriethoxysilane, γ-glycidoxypropylmethoxysilane and γ-aminopropyltriethoxysilane are preferred from the viewpoints of economy and the thermal stability of the polyacetal resin composition constituting the resin guide component of the present embodiment.
Examples of organic titanate compounds include, but are not limited to, tetra-i-propyl titanate, tetra-n-butyl titanate, butyl titanate dimer, tetrastearyl titanate, triethanolamine titanate, titanium acetylacetonate, Examples thereof include titanium lactate, octylene bricol titanate, and isopropyl (N-aminoethylaminoethyl) titanate.
Examples of the organic aluminate compound include, but are not limited to, acetoalkoxyaluminum diisopropylate and the like.
By using a glass-based filler surface-treated with a coupling agent, the durability and wear resistance of the resin guide component of the present embodiment tend to be further increased, and the thermal stability of the resin guide component is increased. It tends to improve.

<Polyethylene resin>
The polyacetal resin composition used for the resin guide part of the present embodiment preferably contains a polyethylene resin having a weight average molecular weight of 500,000 or less.
A polyethylene resin may be used individually by 1 type, or may be used in combination of 2 or more type.
The weight average molecular weight of the polyethylene resin is preferably 500,000 or less. When the weight average molecular weight of the polyethylene resin is 500,000 or less, the generation of chips during molding can be suppressed, and the friction coefficient is lowered when the resin guide part of the present embodiment is slid. And wear resistance are improved.
The weight average molecular weight of the polyethylene resin is more preferably from 10,000 to 400,000, more preferably from 15,000 to 300,000, still more preferably from 20,000 to 200,000, and even more preferably. Is from 30,000 to 150,000.

The weight average molecular weight of the polyethylene resin can be measured by the following method.
A sample of the polyacetal resin composition or a part of the rib portion of the resin guide part is cut out, immersed in hexafluoroisopropanol (hereinafter abbreviated as HFIP), and the dissolved polyacetal resin component is filtered off. When not dissolved in HFIP, the polyacetal resin component may be removed by hydrochloric acid decomposition or the like.
Next, the unmelted residue is dissolved in trichlorobenzene (hereinafter abbreviated as TCB) at 140 ° C. and filtered to separate the glass filler. The obtained filtrate is used for measurement by gel permeation chromatography (hereinafter abbreviated as GPC).
As a column to be used, UT-807 (one) manufactured by Showa Denko KK and GMHHR-H (S) HT (two) manufactured by Tosoh Corporation are connected in series.
TCB is used as the mobile phase, and the sample concentration is 20 to 30 mg (polyethylene resin) / 20 ml (TCB).
The column temperature is 140 ° C., the flow rate is 1.0 ml / min, and measurement is performed using a differential refractometer as a detector.
The weight average molecular weight is calculated using polymethyl methacrylate (hereinafter abbreviated as PMMA) as a standard substance. In this case, the PMMA standard substance has a number average molecular weight of at least 4 samples in the range of about 2,000 to about 1,000,000.

The content of the polyethylene resin is preferably 0.5 parts by mass or more and 8 parts by mass or less, more preferably 1 part by mass or more and 6 parts by mass or less, and still more preferably 1.5 parts by mass with respect to 100 parts by mass of the polyacetal resin. It is 5 parts by mass or less.
By setting the content of the polyethylene resin to 0.5 parts by mass or more, the resin guide component of the present embodiment has good slidability and stable slidability over a long period of time. Also, wear resistance is improved.
Further, by setting the content of the polyethylene resin to 8 parts by mass or less, the mechanical strength of the resin guide component of the present embodiment is reduced, the chips during melt kneading of the resin composition, and the polyethylene in the resin guide component Desorption of the resin component can be suppressed.

The content of the polyethylene resin can be confirmed, for example, by the following method.
The polyacetal resin composition or the resin guide part is incinerated at a sufficiently high temperature (400 ° C. or higher) to remove the resin component. The content of the glass-based filler is determined by the weight of the obtained ash.
Next, the content of the polyethylene resin is obtained by hydrolyzing the polyacetal resin contained in the polyacetal resin composition or the resin-made guide component and subtracting the compounding ratio of the glass filler obtained previously from the residue. Depending on the situation, the presence or absence of other components may be confirmed by IR or the like, and an additional removal operation may be performed.

Examples of the polyethylene resin that can be used in the present embodiment include, but are not limited to, ultra-low density polyethylene, low density polyethylene, high density polyethylene, and linear low density polyethylene. Further, an ethylene copolymer containing 5% by mass or less of a comonomer such as propylene, butene, and octene may be used.
Among these, low-density polyethylene is preferable from the viewpoints of reducing the friction coefficient and quietness.

The polyethylene resin that can be used in this embodiment preferably contains at least one resin having a melting point (hereinafter abbreviated as Tm) of 115 ° C. or less. More preferably, those having a Tm of 110 ° C. or lower are included.
Among the polyethylene resins, when at least one Tm is 115 ° C. or lower, the friction coefficient is low and it becomes very stable, and the wear resistance is improved. Moreover, when manufacturing a polyacetal resin composition by melt-kneading, there also exists an effect which can reduce the torque of an extruder significantly. Thereby, the increase of the discharge amount which was difficult with the composite material of the conventional polyacetal resin and the glass-type filler can be achieved.
In this embodiment, Tm is 4 to 6 mg of a sample of a polyacetal resin composition or a sample cut from a rib part of a resin guide part (preferably thinned with a press or the like), and differential scanning calorimetry (DSC) ), The endothermic peak value obtained when the temperature is raised by 10 ° C./min is used.

<Stabilizer>
The polyacetal resin composition used for the resin guide part of the present embodiment may contain various stabilizers usually used in the polyacetal resin composition as long as the object of the present invention is not impaired.
Examples of the stabilizer include, but are not limited to, antioxidants, formaldehyde, formic acid scavengers, and the like.
Only one stabilizer may be used alone, or two or more stabilizers may be used in combination.
The antioxidant is preferably a hindered phenol antioxidant from the viewpoint of improving the thermal stability of the resin guide part. It does not specifically limit as a hindered phenolic antioxidant, A well-known thing can be used suitably.
The addition amount of the antioxidant is preferably 0.1 parts by mass or more and 2 parts by mass or less with respect to 100 parts by mass of the polyacetal resin.
Formaldehyde and formic acid scavengers are not limited to the following, but include, for example, compounds containing formaldehyde-reactive nitrogen such as melamine and polyamide resins and polymers thereof; hydroxylation of alkali metals or alkaline earth metals Product, inorganic acid salt, carboxylate and the like.
More specifically, calcium hydroxide, calcium carbonate, calcium phosphate, calcium silicate, calcium borate, fatty acid calcium salts (calcium stearate, calcium myristate, etc.) and the like can be mentioned. These fatty acids may be substituted with hydroxyl groups.
The amount of the formaldehyde or formic acid scavenger added is 0.1 to 3 parts by mass of a polymer containing formaldehyde-reactive nitrogen as a formaldehyde or formic acid scavenger for 100 parts by mass of the polyacetal resin. The earth metal fatty acid salt is preferably in the range of 0.1 to 1 part by mass.

<Other ingredients>
The polyacetal resin composition used for the resin guide part of the present embodiment is a filler other than the known glass-based fillers (talc) used in the conventional polyacetal resin compositions, as long as the object of the present invention is not impaired. , Wollastonite, mica, calcium carbonate, etc.), conductivity imparting agents (carbon black, graphite, carbon nanotubes, etc.), colorants (titanium oxide, zinc oxide, iron oxide, aluminum oxide, organic dyes, etc.), sliding imparting Various stabilizers such as agents (various ester compounds, metal salts of organic acids, etc.), ultraviolet absorbers, light stabilizers, and lubricants can also be contained.
The amount of the other components added is preferably 30% by mass or less when the polyacetal resin is taken as 100% by mass for fillers other than glass-based fillers, conductivity-imparting agents, and colorants. About an agent, a ultraviolet absorber, a light stabilizer, and a lubricating material, Preferably it is 5 mass% or less with respect to 100 mass% of polyacetal resins.
Other components may be used alone or in combination of two or more.

[Method for producing polyacetal resin composition]
The polyacetal resin composition used for the resin guide part of the present embodiment is manufactured by mixing and melt-kneading the above-described polyacetal resin, glass-based filler, if necessary, stabilizer, and other components by a known method. can do.
The step of modifying the surface of the glass filler with a substance containing at least one acid and having the function of modifying the surface of the glass filler, and the modified glass filler and the polyacetal resin are mixed. It is preferable to have the process to do.
A method for mixing and melt-kneading the raw material components is not particularly limited, and methods known to those skilled in the art can be used.
Specifically, the components are mixed in advance with a super mixer, tumbler, V-shaped blender, etc., and melt melt kneaded with a twin screw extruder; while the components are supplied to the main throat of the twin screw extruder and melt kneaded And a method of adding components from the middle of the extruder.
Any of these can be used, but in order to improve the mechanical properties of the resin guide part of the present embodiment, the components are fed from the middle of the extruder while being supplied to the main throat of the twin screw extruder and melt kneaded. The method of adding is preferable.
Since the optimum conditions vary depending on the size of the extruder, it is preferable to appropriately adjust the conditions within a range that can be adjusted by those skilled in the art. More preferably, the screw design of the extruder is adjusted in various ways within a range adjustable by those skilled in the art.
When blending the components, it can be added from the middle of the extruder, but is preferably supplied from the main throat. By taking such a manufacturing method, it is surprising that the effect of greatly reducing the torque of the extruder tends to be obtained. Thereby, productivity can be improved significantly.

[Production method of resin guide parts]
The resin guide part of this embodiment can be manufactured by molding the polyacetal resin composition by a known method.
The molding method is not particularly limited, and a known molding method can be used.
Specifically, extrusion molding, injection molding, vacuum molding, blow molding, injection compression molding, decorative molding, other material molding, gas assist injection molding, foam injection molding, low pressure molding, ultra-thin injection molding (ultra-high-speed injection) And molding methods such as molding) and in-mold composite molding (insert molding, outsert molding). Among these, injection molding is preferable.

[Characteristics of resin guide parts]
(Residual distortion of resin guide parts)
The guide component in the present embodiment is combined with a counterpart material having a structure such as a rail-shaped portion or a groove-shaped portion, and is slid along the rail-shaped portion or the groove-shaped portion, so that the specific direction and range are met. This is a sliding part intended to perform the operation. Examples of such a component include a carrier plate used for raising and lowering a window glass in an automobile.
The guide component in this embodiment is a test cut out from the rib part and the strain amount c (%) after performing a load of 75 MPa and unloading from 75 MPa to 15 MPa once on the test piece cut out from the rib part. The difference (dc): (hereinafter referred to as “residual strain”) from the strain amount d (%) after the load of 75 MPa and the unloading from 75 MPa to 15 MPa are repeatedly performed 50 times on the piece. 0.9 points or less.
The residual strain (dc) is preferably 0.8 points or less, more preferably 0.7 points or less, and even more preferably 0.6 points or less.
Residual strain (dc) correlates with plastic deformation under stress. When this value is 0.9 point or less, the wear resistance of the resin guide component of this embodiment is excellent.
Residual strain of the resin guide part can be measured by the method described in Examples described later.

(Elastic strain of resin guide parts)
Further, the resin guide component in the present embodiment has a rib portion, and a strain amount b (%) when a load of 75 MPa is applied to a test piece cut out from the rib portion, and then cut out from the rib portion. The difference (b−c) from the strain amount c (%) after unloading from 75 MPa to 15 MPa is performed on the test piece (hereinafter referred to as “elastic strain”) is 2.5 points. It is as follows. The elastic strain (bc) is preferably 2.0 points or less, more preferably 1.8 points or less, and even more preferably 1.6 points or less.
Elastic strain (bc) correlates with elastic deformation under stress. When this value is 2.5 points or less, the wear resistance of the resin guide component of this embodiment is excellent.
The elastic strain of the resin guide part can be measured by the method described in Examples described later.

(Residual strain rate of resin guide parts)
In addition, the resin guide component in this embodiment is
The residual strain (dc) is
Up to 15 MPa for the test piece cut out from the rib part and the amount of strain d (%) after repeatedly performing unloading up to 75 MPa and unloading up to 15 MPa for the test piece cut out from the rib part. Value ((dc) / (da)) divided by the difference (da) in the strain amount a (%) when the load reaches 15 MPa when the load is applied once. (Distortion rate) is 0.50 or less. Preferably it is 0.48 or less, More preferably, it is 0.46 or less, More preferably, it is 0.44 or less.
The residual strain rate ((dc) / (da)) correlates with plastic deformation under stress. When this value is 0.50 or less, the wear resistance of the resin guide component of this embodiment is excellent.
The residual strain rate of the resin guide part can be measured by the method described in Examples described later.

As shown in FIG. 2, the rib portion is a portion having a lattice shape in many cases, provided for weight reduction and reinforcement of the guide component. Very often the guide parts are provided with ribs. In this embodiment, a flat test piece is cut out from the rib portion of the guide part, and a flat indenter is brought into contact with the plate to load and unload. The load calculates a value at which the stress becomes 15 MPa and 75 MPa from the contact area between the test piece and the indenter. The loading and unloading speed is 1 mm / min. The test is performed on at least test pieces cut out from three or more points, and an average value is calculated.
Note that the contact area between the test piece and the indenter hardly affects the values of residual strain, elastic strain, and residual strain rate. Also, the thickness of the test piece has little effect on these values.
Moreover, when it is a guide component which does not have a rib part, it can substitute by cutting out the part used as a flat plate with uniform thickness, and using it as a test piece.
When the guide component is an integrally molded product, the residual strain, elastic strain, and residual strain rate are substantially the same regardless of the position of the component. In this embodiment, the test piece cut out from the rib part is used for the measurement from the viewpoint that a flat test piece having a certain thickness can be collected.
When the guide part contains an anisotropic filler, the test piece is cut out so that the filler is oriented in a parallel manner with the flat plate, and the compression test is performed in such a way that the load direction is the orientation direction of the filler. Do so as to be vertical.

An example of a load-unloading curve obtained in the measurement of the residual strain, elastic strain, and residual strain rate of the resin guide component of this embodiment is shown in FIG.
The point that reached 15 MPa in the process of performing the first load up to 75 MPa is A, the point that the load of 75 MPa was performed once, B, and the point that the unloading from 75 MPa to 15 MPa was performed once was C, and the load And D is the point where unloading was repeated 50 times.
The amount of strain (%) is calculated by dividing the displacement at each point by the thickness of the test piece.
The residual strain (dc) is the difference between the strain amount (%) at the point D (corresponding to the strain amount d described above) and the strain amount (%) at the point C (corresponding to the strain amount c described above). (Point).
The elastic strain (bc) is the difference between the strain amount (%) at the point B (corresponding to the strain amount b described above) and the strain amount (%) at the point C (corresponding to the strain amount c described above). (Point).
Further, the residual strain rate ((dc) / (da)) is obtained by changing the residual strain (dc) by the strain amount (%) at the point D (corresponding to the strain amount d described above). It is a value divided by the difference (d−a) of the distortion amount (%) in A (corresponding to the distortion amount a described above).

The method for controlling the residual strain (dc), the elastic strain (bc), and the residual strain rate ((dc) / (da)) within a predetermined range is not particularly limited, but is described above. As described above, a polyacetal resin having a block copolymer and / or a terminal OH group content of 0.006 mol% or more with respect to 1 mol of the main chain oxymethylene unit is treated with a film forming agent containing an acid. It is effective to use a glass filler.
In particular, when a film forming agent containing a block copolymer and an acid is used in combination, the adhesiveness at the interface between the polyacetal resin and the glass-based filler is dramatically improved, and the residual strain, elastic strain, and residual strain rate are set as described above. It becomes easy to control within the range.
In order to make the wear resistance of the resin guide part of this embodiment within the above range, when the polyacetal resin composition that is the material of the resin guide part is produced by melt kneading, the glass-based filler is made of polyacetal resin. It is also effective to knead for a longer time. In general, it is considered that the glass-based filler is preferably kneaded in a shorter time during the melt-kneading of the polyacetal resin composition, but in this embodiment, the reverse tendency occurs. Specifically, when the glass filler is supplied from the side feeder at the time of extrusion kneading, it is preferable to supply from the upstream side.
Residual strain is a value that correlates with the amount of strain accumulated by sliding in the presence of foreign matter. In sliding in the presence of foreign matter, foreign matter is repeatedly entered and discharged between the guide component and the counterpart material. For this reason, the load is repeatedly loaded and unloaded by the foreign matter. The smaller the amount of strain accumulated at that time, the harder the guide component is deformed. For this reason, abrasion resistance improves.
Elastic strain is a value that correlates with elastic deformation when a load is locally applied by a foreign object. When this value is large, the amount of local deformation of the guide component increases in the portion where the foreign object is bitten. Then, it becomes difficult for foreign matter to be discharged from a dent generated by the deformation of the guide component. Therefore, the smaller this value, the better the wear resistance in the presence of foreign matter.
Similarly to the residual strain, the residual strain rate is also a value that correlates with the amount of strain accumulated by sliding in the presence of foreign matter. The smaller this value, the better the wear resistance in the presence of foreign matter.

(Component covering the surface of glass filler)
As described above, when the resin guide component of the present embodiment is formed using a resin composition containing a polyacetal resin and a glass-based filler, the resin guide component is cut out from the rib portion of the resin guide component. When the test piece is pulled and fractured, the surface of the glass-based filler protruding from the fracture surface of the broken test piece is covered with a component containing a polyacetal resin having an average thickness of 0.2 μm or more and 3.0 μm or less. preferable.
When the average thickness of the component containing the polyacetal resin is 0.2 μm or more, durability and mechanical strength tend to be improved. Moreover, since chip | tip can be suppressed and the external appearance defect of the guide component obtained can be suppressed, it exists in the tendency for abrasion resistance to improve. Furthermore, productivity tends to be improved because the molding cycle is shortened.
Moreover, when the average thickness of the component containing the polyacetal resin is 3.0 μm or less, a decrease in the fluidity of the polyacetal resin composition is suppressed, and the appearance defect of the resin guide component tends to be suppressed. .
The lower limit value of the average thickness is more preferably 0.3 μm, and still more preferably 0.4 μm.
The upper limit value of the average thickness is more preferably 2.5 μm, still more preferably 2.0 μm.

The tensile break of the resin guide part is performed at a pulling speed of 50 mm / min.
In this embodiment, the average thickness of the component including the polyacetal resin composition covering the surface of the glass-based filler protruding from the fracture surface of the tensile-breaking resin guide part is scanned by the fracture surface of the tensile-breaking resin guide part. It can obtain | require by observing with an electron microscope (SEM).

Although not particularly limited, taking glass fiber as an example of the glass-based filler, a method for measuring the average thickness of the component containing the polyacetal resin described above will be specifically described below.
In the resin guide part of the present embodiment, when measuring the average thickness of the component containing the polyacetal resin composition covering the surface of the glass fiber, as the glass fiber to be measured, the center of the fracture surface of the resin guide part that has been tensile fractured It is preferable to select a glass fiber present in the vicinity.
First, at least 50 glass fibers protruding from the fracture surface are selected at random. Next, the layer of the component covering the surface of the glass fiber is observed, and the thickness of the layer is measured. When the thickness of the layer is not uniform, the maximum value is adopted as the thickness of the layer. Then, the average thickness is calculated by averaging the thicknesses of the 50 layers.
When the resin component uniformly covers the surface of the glass fiber, the boundary between the glass fiber and the component layer covering the surface may not be clear. In such a case, the thickness of the layer covering the surface may be calculated using the diameter of the glass fiber alone. For example, when the resin component uniformly covers the surface of the glass fiber having a circular cross section, the thickness of the layer covering the surface is obtained by the following formula.
The thickness of the layer covering the surface = (the diameter including the layer−the diameter of the glass fiber) / 2

The diameter of the glass fiber alone can be obtained by measuring a residue obtained by removing the resin component from the resin guide part.
As a method for removing the resin component from the resin guide part, for example, a method of incinerating the resin component in the resin guide part at a sufficiently high temperature (400 ° C. or higher), a resin immersed in a solvent that dissolves the polyacetal resin Examples thereof include a method for removing a resin component in the guide part.

In this embodiment, the surface of the glass-based filler is preferably a component containing a polyacetal resin in an area ratio of preferably 50% or more, more preferably 70% or more, still more preferably 80% or more, and even more preferably 90% or more. It is preferable that it is covered with.
When the area ratio of the component including the polyacetal resin that covers the surface of the glass filler is 50% or more, the wear resistance of the resin guide component of the present embodiment is further improved.

In order to cover the surface of the glass-based filler with a component containing a polyacetal resin having an average thickness of 0.2 μm or more and 3.0 μm or less, for example, the polyacetal resin contains the aforementioned block copolymer and / or terminal OH group Examples thereof include the use of an amount of 0.006 mol% or more based on 1 mol of the main chain oxymethylene unit, and the use of a film forming agent containing the aforementioned acid.
Above all, when a film-forming agent containing a block copolymer and an acid is used in combination, the adhesion of the interface between the polyacetal resin and the glass filler is dramatically improved, and the average of the components containing the polyacetal resin covering the surface of the glass filler Thickness increases.
Moreover, in order to make the said average thickness in the said range, when manufacturing a polyacetal resin composition by melt-kneading, it is also effective to knead | mix a glass-type filler with polyacetal resin for a long time. In general, it is considered that it is desirable to knead the glass-based filler in a shorter time when the resin composition is melt-kneaded. However, in this embodiment, the reverse tendency occurs. Specifically, when the glass filler is supplied from the side feeder during extrusion kneading, it may be supplied from the upstream side.

  In this embodiment, the component containing the polyacetal resin composition constituting the layer covering the surface of the glass-based filler is a polyacetal resin as a main component, but is a resin component containing the aforementioned polyethylene resin and / or stabilizer. There may be.

(Abundance of polyethylene resin on the surface of guide parts)
In the resin guide part of the present embodiment, the abundance of the polyethylene resin within the surface layer of 10 nm of the test piece cut out from the rib part of the resin guide part is from the surface layer of the test piece cut out from the rib part of the resin guide part. It is preferable that the amount of polyethylene resin is larger than the existing amount of the surface layer within 10 nm of the surface obtained by cutting out a deep layer from 1,000 μm.
The abundance of the polyethylene resin can be calculated from the relative element concentration (atomic%) of carbon C measured using X-ray photoelectron spectroscopy (XPS).
Examples of the measuring device include ESCALAB250 manufactured by Fisher Scientific Co., Ltd.
As an excitation source at the time of measurement, it is preferable to use monoAlKα.
In addition, in order to remove the influence of adhering contamination components adhering to the rib part surface of the guide part, the rib part surface of the guide part is ultrasonically cleaned with a cleaning agent (for example, an aqueous solution of VALTRON DP97031), washed with pure water, Dry in an oven.
In XPS measurement, Binding Energy 286 to 288 eV is carbon derived from a polyacetal resin, and 284 to 286 eV is carbon derived from an olefin such as polyethylene. Therefore, when the peak can be separated, only carbon of a component derived from polyethylene is used. If separation is not possible, a peak area in the range of 284 to 288 eV may be used.

The surface layer of the surface obtained by cutting out the carbon concentration within 10 nm from the surface layer of the rib part of the resin guide part and C ₁ and the center part of the rib part of the resin guide part (deeper than 1,000 μm of the rib part of the guide part) When the carbon concentration C ₂ within 10 nm is used, it is preferable that the following equation holds.
[C ₁ ] / [C ₂ ]> 1
When the above equation holds, it can be said that a large amount of (C) polyethylene resin is present within 10 nm from the surface layer.
More preferably, 1.01 ≦ [C ₁ ] / [C ₂ ] ≦ 1.20, still more preferably 1.02 ≦ [C ₁ ] / [C ₂ ] ≦ 1.18, and even more preferably. Is 1.05 ≦ [C ₁ ] / [C ₂ ] ≦ 1.15.

When a block copolymer having a block component represented by the above formula (3) is used as the polyacetal resin, the carbon concentration itself of the polyacetal resin increases.
However, since there is no difference in the carbon concentration derived from the polyacetal resin within 10 nm from the surface layer and deeper than 1,000 μm, it can be said that a large amount of polyethylene resin exists within 10 nm from the surface layer when the above equation holds.

In the resin guide part of the present embodiment, the portion where C ₂ is measured is a deeper part than the 1,000 μm of the rib part of the resin guide part, but in the resin guide part of the present embodiment, If it is deeper than 100 μm from the surface layer, the abundance of the polyethylene resin is almost the same value as the charging ratio regardless of the location.

  As described above, the presence of the polyethylene resin in the surface layer within 10 nm is larger than the amount of the polyethylene resin in the surface layer within 10 nm on the surface of the resin guide component surface cut out from the surface of 1000 μm. Abrasion resistance is improved. In addition, since the effect of wear resistance in the presence of foreign matter can be drastically improved with a small amount of polyethylene blended, a decrease in mechanical strength such as bending elastic modulus can be suppressed. Furthermore, a surprising effect of drastically suppressing chips during melt kneading with the resin can also be obtained.

In the case of the rib portion having a thickness of less than 2,000 μm, the carbon concentration in the central portion in the depth direction of the rib portion can be used instead of the carbon concentration in the deep layer portion from 1,000 μm.
In order to make the polyethylene resin within 10 nm from the surface layer of the rib portion more than the deep layer portion than 1,000 μm of the rib portion, it is achieved by setting the weight average molecular weight of the blended polyethylene resin to 500,000 or less. it can. Further, by setting the melting point of the polyethylene resin to 115 ° C. or less, the abundance of the polyethylene resin within 10 nm from the surface layer of the rib part can be made larger than the deep part of 1,000 μm of the rib part.
[Partner material]
The resin guide component in the present embodiment is used in combination with a counterpart material. The counterpart material is not particularly limited, and examples thereof include synthetic resins such as polyacetal resin, polyamide resin, and polybutylene terephthalate resin, and metals such as aluminum, iron, galvanized steel, and stainless steel.

[Use]
Since the resin guide component of this embodiment is excellent in durability, mechanical strength, and wear resistance in the presence of foreign matter, it can be suitably used for various applications.
In particular, there are mechanical parts for automobiles, mechanical parts for electronic devices, and guide parts for mechanical parts for electric vehicles. In particular, it can be suitably used as a carrier plate used for raising and lowering window glass in automobiles.
Specific applications of the resin guide parts are not limited to the following, but include, for example, mechanism parts for office automation equipment, mechanism parts for cameras or video equipment, mechanism parts for music, video or information equipment, and mechanisms for communication equipment. Parts, mechanical parts for electrical equipment, mechanical parts for electronic equipment, automotive mechanical parts (door peripheral parts, seat peripheral parts, air conditioner peripheral parts), bicycle mechanical parts (drive motor transmission, etc.), switch parts, stationery mechanism Examples include mechanical parts for housing equipment, mechanical parts for vending machines, mechanical parts for sports / leisure / recreational equipment, and mechanical parts for industrial equipment.
In addition, the resin guide component according to the present embodiment can be applied to automobiles and electric vehicles in general from the viewpoint of maintaining remarkably superior slidability and wear resistance compared to conventional guide components. . Here, examples of the electric vehicle include, but are not limited to, senior four-wheels, motorcycles, and electric motorcycles.
The resin guide component is preferably used by applying grease. Thereby, durability and abrasion resistance can be greatly improved.

Hereinafter, the present embodiment will be described with specific examples and comparative examples. However, the present embodiment is not limited to the examples described later.
The production conditions and evaluation items of the polyacetal resin compositions and resin guide parts used in the examples and comparative examples are as follows.

[Production conditions of polyacetal resin composition and resin guide parts]
((1) Production conditions of polyacetal resin composition: extrusion conditions)
In the production of the polyacetal resin composition, the ratio of the screw length L to the screw diameter D (L / D) = 48 (number of barrels 12), side feeders in the sixth barrel and the eighth barrel, A co-rotating twin screw extruder (TEM-48SS extruder manufactured by Toshiba Machine Co., Ltd.) equipped with a vacuum vent in the barrel was used.
The first barrel was water-cooled, the second to fifth barrels were set to 210 ° C, and the sixth to twelfth barrels were set to 180 ° C.
The screw used for extrusion was designed as follows.
Two kneading discs (hereinafter abbreviated as RKD) having a flight capability at the position of the first barrel to the fourth barrel and a flight screw (hereinafter abbreviated as FS) at the position of the fifth barrel. Two kneading discs (hereinafter abbreviated as NKD) and one kneading disc (hereinafter abbreviated as LKD) capable of feeding in the reverse direction were arranged in this order.
FS was arranged at the positions of the sixth to eighth barrels, RKD and NKD were arranged one by one at the position of the ninth barrel in this order, and FS was arranged at the positions of the tenth to eleventh barrels.
A glass-based filler was supplied from the side feeder of the eighth barrel, extruded at a screw rotation speed of 150 rpm, and a total extrusion rate of 70 kg / h to obtain pellets of a polyacetal resin composition.

(2) Manufacture of resin guide parts (carrier plate) An injection molding machine (FANUC Robot (registered trademark) i50B type, manufactured by FANUC CORPORATION) was used. As molding conditions, the resin temperature was 200 ° C., the mold temperature was 80 ° C., and the injection pressure and holding pressure were 150 MPa. A carrier plate having a length of 120 mm, a width of 80 mm, a thickness of 3 mm, a guide sliding portion at the center, and a cross-shaped rib was formed by injection molding. Two gates were placed on the long side of the carrier plate, and the distance from the center was uniform.

[Characteristic evaluation of resin guide parts]
((1) Distortion amount of resin guide parts (carrier plate))
Three flat test pieces of 6 mm × 6 mm × 2.5 mm were arbitrarily cut out from the rib portion of the carrier plate. A universal testing machine (Instron (registered trademark) 5566, manufactured by Instron) was used for the measurement. A test piece was placed on a flat surface and evaluated by applying a compressive load. The indenter used was a circular plane having a diameter of 1 cm. From the contact area between the test piece and the indenter, the load at which the stress was 15 MPa and 75 MPa was calculated, and the load and unloading up to the corresponding compressive load were repeated 50 times. The loading and unloading speed was 1 mm / min. Measure the strain after loading once, then strain after unloading once, and strain after repeated loading and unloading 50 times. The amount of each strain is the thickness of the rib part. The amount of strain (%) was calculated by dividing.
In FIG. 3, the load-unloading curve obtained by the compression test in Example 1 mentioned later is shown.
In FIG. 4, the load-unloading curve obtained by the compression test in the comparative example 5 mentioned later is shown.
Residual strain: the difference (point) between the strain amount (%) at point D (corresponding to the strain amount d described above) and the strain amount (%) at point C (corresponding to the strain amount c described above). .
Elastic strain: the difference (point) between the strain amount (%) at point B (corresponding to the strain amount b described above) and the strain amount at point C (corresponding to the strain amount c described above).
Residual strain rate: The residual strain (dc) is the strain amount (%) at the point D (corresponding to the strain amount d described above) and the strain amount (%) at the point A (the strain amount a described above). It is ((dc) / (da)) divided by the difference (da).
From the above, residual strain, elastic strain and residual strain rate were calculated. The test was performed on three test pieces, and an average value was adopted.

((2) Average thickness of the component layer covering the surface of the glass-based filler)
A test piece of 6 mm × 6 mm × 2.5 mm was cut out from the rib portion of the carrier plate and was broken using a tensile tester at a tensile speed of 50 mm / min.
A specimen for observation was prepared by depositing platinum on the fracture surface of the specimen.
The thickness of the component layer covering the surface of the glass-based filler was measured by observing with a scanning electron microscope (SEM) using the observation specimen.
The observation magnification was 5,000 times.
As an observation site | part, it was set as the fracture surface center part of the test piece, and it adjusted so that the said fracture surface center part could be observed.
Arbitrary 50 pieces of glass-based fillers protruding from the fracture surface were selected.
In all the glass-based fillers, it was confirmed that the resin component uniformly covered the surface of the glass-based filler having a circular cross section.
Next, the diameter of the glass-type filler covered with the resin component was measured.
Separately, the thickness of the resin component adhering to the surface was determined based on the difference from the diameter of the glass-based filler (average value of 100) obtained by incinerating the test piece at 450 ° C. for 3 hours to remove the resin component. Asked.
The 50 samples were averaged to obtain the average thickness of the component layers covering the surface of the glass filler.

((3) Ratio of polyethylene resin in the surface layer (surface polyethylene ratio))
A 6 mm × 6 mm × 2.5 mm flat test piece was cut out from the rib portion of the carrier plate. X-ray photoelectron spectroscopy (XPS) ESCALAB250 manufactured by Thermo Fisher Scientific Co., Ltd. was used, and monoALKα (15 kV × 10 mA) was used as an excitation source.
The analysis size was 1 mm square.
To remove surface deposits, use a commercially available 1.5% aqueous solution for precision equipment (VALTRON DP97031) for ultrasonic cleaning at 50 ° C for 3 minutes to remove organic substances on the surface. Then, ultrasonic treatment was performed with distilled water for high performance liquid chromatography at room temperature for 15 minutes, and washing was performed.
Next, the test piece after washing was subjected to a drying treatment at 80 ° C. for 1 hour in a drying oven and subjected to measurement.
In the measurement, the photoelectron take-off angle was 0 ° (perpendicular to the surface of the test piece), and the take-in area was 0 to 1100 eV for Survey Scan and 1 s for Narrow Scan carbon C.
In addition, the Pass Energy was conducted at a survey scan of 100 eV and a narrow scan of 20 eV.
The C concentration at this time was a peak area ratio in the range of 284 eV to 288 eV.
The relative element concentration was calculated from the area ratio and rounded off, and those with 1 atomic% or more were calculated with 2 significant digits, and those with less than 1 atomic% were calculated with 1 significant digit.
The carbon concentration in the surface layer of the test piece was defined as [C ₁ ].
Subsequently, the center in the thickness direction of the test piece was cut out with a microtome, and the carbon concentration [C ₂ ] in the vicinity of the center portion in the thickness direction (1.25 mm from the surface layer portion) was measured by the same measurement.
[C ₁ ] / [C ₂ ] was calculated, and this was defined as “the abundance ratio of the polyethylene resin in the surface layer”.

(4) Thrust sliding characteristics in the presence of foreign matter Using an injection molding machine (FANUC Robot (registered trademark) i50B type, manufactured by FANUC CORPORATION), a hollow shape having an outer diameter of 25.6 mm, an inner diameter of 20 mm, and a thickness of 15 mm A thrust ring was formed. As molding conditions, the resin temperature was 200 ° C., the mold temperature was 80 ° C., and the injection pressure and holding pressure were 80 MPa.
A viscous material obtained by mixing 5 g of grease and 5 g of sand having an average particle diameter of 200 μm was applied to a SUS flat plate, and a thrust sliding test was performed using the thrust ring. The test is based on JIS K7218, with a surface pressure of 1 MPa and a speed of 5 cm / sec. It was. The coefficient of friction after sliding for 4 hours was evaluated. The lower the coefficient of friction, the better the sliding characteristics in the presence of foreign matter.

(5) Durability of guide parts A carrier in which a viscous material mixed with 10 g of grease and 10 g of sand having an average particle diameter of 200 μm is applied to the sliding surface of an aluminum guide rail and a load of 2 kg in the vertical direction is applied. The plate was moved up and down. The state of the sliding surface of the carrier plate after driving 10,000 times was visually observed. Evaluation was based on the following criteria A: No scratches were observed.
○: Although scratches are visible, deformation such as shaving was not observed.
Δ: Some shaving was observed, but there was no problem in driving.
X: Scraping occurred during driving and stopped.

[Polyacetal resin composition and raw material components of resin guide parts]
Next, the raw material components of the polyacetal resin compositions and resin guide parts used in Examples and Comparative Examples will be described below.
(Polyacetal resin)
As the polyacetal resin, the following (A1) to (A4) were used.
(A1) Product name: Tenac (registered trademark) -C 4520 (manufactured by Asahi Kasei Chemicals Corporation), copolymer, melt flow rate (MFR) = 9.0 g / 10 min, number average molecular weight Mn = about 70,000, main chain Terminal OH group content with respect to 1 mol of oxymethylene unit of 0.0055 mol%
(A2) Product name: Tenac (registered trademark) MG210 (manufactured by Asahi Kasei Chemicals Corporation), homopolymer, melt flow rate (MFR) = 1.7 g / 10 minutes (A3) A polyacetal block copolymer is prepared as follows. Prepared.
A twin-screw paddle type continuous polymerization machine with a jacket through which a heat medium can pass was adjusted to 80 ° C. 40 mol / hr of trioxane, 1,3-dioxolane as a cyclic formal 2 mol / hour, trioxane boron trifluoride di -n- butyl etherate dissolved in cyclohexane as a polymerization catalyst relative to 1 mol 5 × 10 ^{- An} amount of ⁵ moles, and a hydrogenated polybutadiene (number average molecular weight Mn = 2,330) represented by the following formula (4) as a chain transfer agent is 1 × 10 ⁻³ moles per mole of trioxane. Polymerization was conducted by continuously feeding the polymerizer in an amount.

Next, 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 to obtain a crude polyacetal block copolymer.
To 100 parts by mass of the obtained crude polyacetal block copolymer, 1 part by mass of an aqueous solution containing a quaternary ammonium compound (described in Japanese Patent No. 3087912) was added and mixed uniformly. The amount of the quaternary ammonium compound added was 20 mass ppm in terms of nitrogen. This was supplied to a twin screw extruder with a vent, and 0.5 parts by mass of water was added to 100 parts by mass of the melted polyacetal block copolymer in the extruder. The unstable terminal portion of the polyacetal block copolymer was decomposed and removed at an extruder set temperature of 200 ° C. and a residence time of 7 minutes in the extruder.
To the polyacetal block copolymer in which the unstable terminal portion is decomposed, 0.3 parts by mass of triethylene glycol-bis- [3- (3-tert-butyl-5-methyl-4-hydroxyphenyl) -propionate] as an antioxidant Was extruded as a strand from the extruder die and pelletized while devolatilizing under a condition of a vacuum of 20 Torr with an extruder equipped with a vent.
The polyacetal block copolymer thus obtained was used as (A3) polyacetal block copolymer. This block copolymer was an ABA type block copolymer, and the melt flow rate was 15 g / 10 min (ISO-1133 condition D). The number average molecular weight Mn calculated from the melt flow rate was about 50,000. The terminal OH group content relative to 1 mol of oxymethylene units in the main chain was 0.0103 mol%.
(A4) A polyacetal resin was obtained in the same manner as in the above (A3) except that ethylene glycol was used instead of the both-end hydroxyl group-hydrogenated polybutadiene. The terminal OH group content relative to 1 mol of oxymethylene units in the main chain was 0.0078 mol%.
The terminal OH group content in the polyacetal resin was measured by the following method.
10 mg of polyacetal resin was added to 1 mL of a mixed solvent of hexafluoroisopropyl alcohol and chloroform (mass ratio 1/1) and allowed to stand overnight. Furthermore, it heated at 40 degreeC for 4 hours, and made it melt | dissolve.
Next, 0.2 mL of N, O-bis (trimethylsilyl) trifluoroacetamide was added as a silylating agent and heated at 40 ° C. for 2.5 hours. After releasing into the atmosphere and air-drying overnight, it was confirmed that the solvent was volatilized, and then vacuum-dried at 80 ° C. overnight.
10 mg of the polyacetal resin terminally trimethylsilylated by the above operation was dissolved in 0.8 mL of a mixed solvent of hexafluoroisopropyl alcohol-d and chloroform-d (volume ratio 1/1) at 55 ° C. A sample for measurement was obtained.
Using ECA500 type manufactured by JEOL Ltd., ¹ H NMR was measured. From the obtained spectrum, based on the integrated value of the peak of 4.95 ppm (attributed to the oxymethylene unit), the integrated value of the peak of 0.17 to 0.23 ppm (attributed to the trimethylsilylated terminal OH group), The terminal OH group content was calculated.

(Glass filler)
The following glass fillers were used.
(B1) Glass fiber treated with a film-forming agent (containing a copolymer of acrylic acid and methyl acrylate) described in Production Example 1 of Japanese Patent No. 4060831.
(B2) Sample No. of Japanese Unexamined Patent Publication No. 2009-7179. A glass fiber treated with the film-forming agent according to 1 (containing no acid).

(Polyethylene resin)
As the polyethylene resin, Santec (registered trademark) LD L1850A (weight average molecular weight 132,000, Tm = 107 ° C., density 918 kg / m ³ ) manufactured by Asahi Kasei Chemicals Corporation was used.
The weight average molecular weight was measured by GPC as follows using a solution obtained by dissolving polyethylene resin in TCB at 140 ° C.
As a column to be used, UT-807 (one) manufactured by Showa Denko KK and GMHHR-H (S) HT (two) manufactured by Tosoh Corporation were connected in series.
TCB was used as the mobile phase, and the sample concentration was 20 to 30 mg (polyethylene resin) / 20 ml (TCB). The column temperature was 140 ° C., the flow rate was 1.0 ml / min, and measurement was performed using a differential refractometer as a detector. The weight average molecular weight was calculated using PMMA as a standard substance.

[Examples 1 to 6]
Each component was blended as shown in Table 1, kneaded and molded to obtain a carrier plate and a thrust ring. The evaluation results are shown in Table 1. In all examples, the difference in residual strain (%) was 0.9 point or less, and the wear resistance in the presence of foreign matter was good.

[Comparative Examples 1-5]
Each component was blended as shown in Table 1, kneaded and molded to obtain a carrier plate and a thrust ring. The evaluation results are shown in Table 1. In any of the comparative examples, the difference in residual strain (%) exceeded 0.9 point, which resulted in poor wear resistance in the presence of foreign matter.

  The guide component of the present invention has industrial applicability particularly in the field of automotive mechanism components that require wear resistance in the presence of foreign matter.

1 Guide sliding part 2 Guide sliding assist part 3 Rib part

Claims (25)

A resin guide part having a rib part,
With respect to the test piece cut out from the rib part, a strain amount c (%) after performing a load of 75 MPa and unloading from 75 MPa to 15 MPa once,
The difference (dc: residual strain) from the strain amount d (%) after the load of 75 MPa and the unloading from 75 MPa to 15 MPa were repeated 50 times for the test piece cut out from the rib portion, Resin guide parts with 0.9 points or less. A resin guide part having a rib part,
The amount of strain b (%) when a load of 75 MPa is applied once to the test piece cut out from the rib portion, and the amount of strain c (%) after the unloading from 75 MPa to 15 MPa is performed once thereafter. Resin guide parts whose difference (bc: elastic strain) is 2.5 points or less. A resin guide part having a rib part,
With respect to the test piece cut out from the rib part, a load of 75 MPa and a strain amount c (%) after performing unloading from 75 MPa to 15 MPa once, and with respect to the test piece cut out from the rib part, 75 MPa The difference between the load and the amount of strain d (%) after repeating unloading from 75 MPa to 15 MPa 50 times (dc: residual strain),
With respect to the test piece cut out from the rib part, the strain amount d (%) after the load of 75 MPa and unloading from 75 MPa to 15 MPa were repeated 50 times for the test piece cut out from the rib part, and the test piece cut out from the rib part, A value ((dc) / (da)) divided by the difference (da) in the strain amount a (%) when the load reaches 15 MPa when the load up to 15 MPa is performed once. : Residual guide component having a residual strain ratio) of 0.50 or less.   The resin guide part according to any one of claims 1 to 3, comprising a polyacetal resin. For 100 parts by mass of the polyacetal resin,
The resin guide component according to claim 4, comprising 10 to 100 parts by mass of the glass filler.   When the test piece cut out from the rib portion is pulled and fractured, the surface of the glass-based filler protruding from the fracture surface is covered with a component containing a polyacetal resin having an average thickness of 0.2 μm or more and 3.0 μm or less. The resin guide component according to claim 5.   The resin guide component according to claim 5 or 6, comprising at least one acid as a substance having a function of modifying the surface of the glass filler.   The resin guide component according to claim 7, wherein the acid is a carboxylic acid.   The resin guide part according to any one of claims 4 to 8, wherein the polyacetal resin contains a block component.   The resin guide component according to claim 9, wherein the block component is a hydrogenated polybutadiene component in which both ends are hydroxyalkylated.   The resin-made guide component according to any one of claims 4 to 10, wherein a content of the terminal OH group in the polyacetal resin is 0.006 mol% or more with respect to 1 mol of oxymethylene units of the main chain. For 100 parts by mass of the polyacetal resin,
The resin guide component according to any one of claims 4 to 11, further comprising 0.5 parts by mass or more and 8 parts by mass or less of a polyethylene resin having a weight average molecular weight of 500,000 or less.   The resin guide component according to claim 12, wherein the polyethylene resin has a melting point of 115 ° C. or less.   The abundance of the polyethylene resin in the surface layer within 10 nm of the test piece cut out from the rib part is from the abundance of the polyethylene resin in the surface layer within 10 nm of the surface cut out from the surface layer of the test piece cut out from the rib part from 1,000 μm. The resin guide component according to claim 12 or 13, wherein there are many.   The resin guide part according to any one of claims 1 to 14, which is a carrier plate for an automobile window glass. A polyacetal resin composition used for the resin guide part according to any one of claims 1 to 3,
A polyacetal resin composition for resin guide parts, comprising 100 parts by mass of a polyacetal resin and 10 to 100 parts by mass of a glass-based filler. For 100 parts by mass of the polyacetal resin,
The polyacetal resin composition for resin guide parts according to claim 16, further comprising 0.5 parts by mass or more and 8 parts by mass or less of a polyethylene resin having a weight average molecular weight of 500,000 or less.   The polyacetal resin composition for resin guide parts of Claim 17 whose melting | fusing point of the said polyethylene resin is 115 degrees C or less.   The polyacetal resin composition for resin guide parts according to any one of claims 16 to 18, comprising at least one acid as a substance having a function of modifying the surface of the glass filler of the glass filler. object.   The polyacetal resin composition for resin guide parts according to claim 19, wherein the acid is a carboxylic acid.   The polyacetal resin composition for resin guide parts according to any one of claims 16 to 20, wherein the polyacetal resin contains a block component.   The polyacetal resin composition for resin guide parts according to claim 21, wherein the block component is a hydrogenated polybutadiene component in which both ends are hydroxyalkylated.   The polyacetal resin for resin guide parts according to any one of claims 16 to 22, wherein the content of the terminal OH group in the polyacetal resin is 0.006 mol% or more based on 1 mol of the oxymethylene unit of the main chain. Composition. A method for producing a polyacetal resin composition for resin guide parts according to any one of claims 16 to 23,
A step of modifying the surface of the glass-based filler with a substance containing at least one acid and having a function of modifying the surface of the glass-based filler;
Mixing the modified glass-based filler and a polyacetal resin;
The manufacturing method of the polyacetal resin composition for resin guide parts containing this.   A method for producing a resin guide part, comprising a step of molding the polyacetal resin composition for a resin guide part according to any one of claims 16 to 23.