JP2005297456A - Abrasion-resistant resin member and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enhance abrasion resistance in a resin member. <P>SOLUTION: The abrasion-resistant resin member contains a liquid crystal polymer and the molecular chain of the liquid crystal polymer is oriented in the direction crossing at least one surface of the resin member. By this constitution, the abrasion resistance of the surface of the resin member is enhanced. The degree α of orientation of the liquid crystal polymer is preferably set to 0.5 to 1.0. In the manufacturing method of the abrasion-resistant resin member, the molecular chain of the liquid crystal polymer is oriented by a magnetic field. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a wear-resistant resin member member having excellent wear resistance, which can be used for a sliding portion of an electronic device or a machine part, a surface in contact with the outside, or the like.

  Among plastics, engineering plastics are particularly excellent in heat resistance and mechanical strength, and are lighter than metals, and thus serve as substitutes for metallic members in electrical / electronic devices and mechanical parts. Among these, especially when used for a member having a surface that slides against other members (sliding member) such as a bearing, a large shearing force is generated at the contact portion with the corresponding member. The material forming the moving member is required to have high wear resistance. As a method of improving wear resistance in engineering plastics, a method of forming an alloy with an engineering plastic as a base material and another polymer having desired characteristics, an organic, inorganic or metal powder or short fiber in the base material, There are methods for filling whiskers and the like.

  However, when other polymers are added to the engineering plastic, the friction coefficient is lowered, but the desired wear resistance may not be obtained. In addition, simply adding fillers such as short fibers and powders to engineering plastics may not provide sufficient wear resistance, and may cause problems that the corresponding members are worn by the filler. . In order to cope with such a problem, a technique using molecular orientation of a resin as a base material has been proposed.

  For example, Patent Document 1 discloses a cylindrical resin bearing in which the constituent material is oriented in the circumferential direction of the bearing depending on injection molding conditions. By orienting the constituent materials in the circumferential direction of the bearing, the wear resistance and friction characteristics on the bearing surface are improved.

Patent Document 2 discloses a sliding sheet material in which a fluorine resin, an aromatic polyester resin, or the like is rolled or stretched so that the molecules thereof are oriented in a direction parallel to the sheet surface. In this sliding sheet material, the frictional resistance on the sheet surface is reduced by the orientation of the molecules.
JP 2000-145786 A JP-A-9-95543

  However, all of the conventional sheets are obtained by orienting resin molecules parallel to a surface that requires wear resistance. According to the study by the present inventors, such a method sometimes fails to provide sufficient wear resistance on the surface of the resin member.

  The present inventors have developed a technique for orienting resin molecular chains in an arbitrary direction in a resin member, and by orienting the resin molecular chains in a direction perpendicular to the surface of the resin member, wear resistance on the surface thereof is developed. I found that sex improved dramatically.

  The present invention is based on such knowledge, and an object thereof is to provide a wear-resistant resin member having more excellent wear resistance.

  In order to solve the above problems, the invention according to claim 1 is a resin member containing a liquid crystalline polymer, and in order to improve wear resistance, the molecular chain of the liquid crystalline polymer is The gist is that the resin member is oriented in a direction crossing at least one surface of the resin member.

According to a second aspect of the present invention, in the wear-resistant resin member according to the first aspect, the degree of orientation α of the liquid crystalline polymer determined by the following formula from X-ray diffraction measurement of the member is 0.5 or more. A range of less than 1.0,
Orientation degree α = (180−Δβ) / 180 (1)
In the above formula, Δβ represents the full width at half maximum when measuring the intensity distribution from 0 to 360 degrees in the azimuth direction while fixing the peak scattering angle by X-ray diffraction measurement.

The gist of the invention described in claim 3 is the wear-resistant resin member according to claim 1 or 2, wherein the liquid crystalline polymer is a thermal liquid crystalline polymer.
The invention according to claim 4 is the wear resistant resin member according to claim 3, wherein the thermal liquid crystalline polymer is at least one selected from aromatic polyester and aromatic polyester amide. .

  The invention according to claim 5 is the wear-resistant resin member according to claim 1 or 2, wherein the liquid crystalline polymer is a polymer obtained by crosslinking or polymerizing a liquid crystalline monomer. Is the gist.

The gist of the invention described in claim 6 is the wear-resistant resin member according to claim 5, wherein the liquid crystalline monomer is a liquid crystalline epoxy resin.
The invention according to claim 7 comprises a liquid crystalline polymer, and in order to improve the wear resistance, the molecular chain of the liquid crystalline polymer is oriented in a direction intersecting at least one surface. A method for producing a liquid crystalline resin member, the step of preparing a liquid crystalline composition containing either a liquid crystalline polymer or a liquid crystalline monomer, and the liquid crystalline polymer and liquid crystalline monomer in the liquid crystalline composition Applying a magnetic field to the liquid crystal composition in a direction perpendicular to at least one surface thereof, and any of the liquid crystalline polymer and the liquid crystalline monomer in the direction The gist is to have a step of orienting molecular chains and a step of solidifying the liquid crystalline composition while maintaining the orientation of the molecular chains.

  The gist of the invention described in claim 8 is that, in the method described in claim 7, the step of developing the liquid crystal property is performed by melting the liquid crystal composition.

  According to the first aspect of the present invention, in the resin member, by orienting the molecular chain of the liquid crystalline polymer in a direction intersecting with at least one surface, the wear resistance is dramatically improved on the surface. be able to.

According to the second aspect of the present invention, the molecular chains of the liquid crystalline polymer are more highly oriented, and higher wear resistance is obtained on the surface intersecting the orientation direction.
According to invention of Claim 3, the resin member which has high abrasion resistance can be obtained easily.

According to invention of Claim 4, the resin member which has higher abrasion resistance can be obtained.
According to invention of Claim 5, the resin member which has higher abrasion resistance can be obtained.

According to invention of Claim 6, the resin member which has higher abrasion resistance can be obtained.
According to invention of Claim 7, the resin member which has the outstanding abrasion resistance can be manufactured easily.

  According to invention of Claim 8, the resin member which has the outstanding abrasion resistance can be manufactured more easily.

Hereinafter, an embodiment of the present invention will be described in detail.
An embodiment in which the wear-resistant resin member of the present invention is embodied as the wear-resistant resin sheet 11 will be described with reference to FIG. The abrasion-resistant resin sheet 11 contains a liquid crystalline polymer, and the molecular chain of the liquid crystalline polymer intersects the surface of the abrasion-resistant resin sheet 11, preferably in the orthogonal direction (in this embodiment, FIG. 1 In the Z-axis direction). By orienting the rigid molecular chain of the liquid crystalline polymer in a direction perpendicular to the surface of the abrasion-resistant resin sheet 11, the abrasion resistance on the surface is dramatically improved.

In this wear-resistant resin sheet 11, the orientation degree α of the liquid crystalline polymer obtained by the following formula (1) from wide-angle X-ray diffraction measurement is preferably in the range of 0.5 or more and less than 1.0.
Orientation degree α = (180−Δβ) / 180 (1)
(In the above formula, Δβ represents the half width when the intensity distribution from 0 to 360 degrees in the azimuth direction is measured with the peak scattering angle determined by X-ray diffraction measurement fixed.)
Below, each component of the abrasion-resistant resin sheet 11 of this invention is explained in full detail.

<Liquid crystal polymer>
The liquid crystalline polymer exhibits optical anisotropy by regularly arranging molecular chains of the polymer in a liquid crystal state. This optical anisotropy can be confirmed by developing a strong birefringence characteristic of liquid crystal in a normal polarization inspection method using orthogonal polarizers. In the present invention, the “liquid crystalline polymer” includes a polymer that can take at least part of a liquid crystal structure and a polymer that at least partly maintains the liquid crystal structure depending on conditions such as temperature or concentration. . Specific examples of the liquid crystalline polymer include a thermal liquid crystalline polymer (thermotropic liquid crystalline polymer), a cured product of a liquid crystalline monomer, and a lyotropic liquid crystalline polymer.

The thermal liquid crystalline polymer is a polymer having thermoplasticity, and is a liquid crystalline polymer in a liquid crystal state exhibiting optical anisotropy in a predetermined temperature range.
The cured product of the liquid crystalline monomer maintains the liquid crystal structure by polymerizing and curing the liquid crystalline monomer exhibiting optical anisotropy in a predetermined temperature range by crosslinking reaction or polymerization reaction while maintaining the liquid crystal state. It is a liquid crystalline polymer solidified as it is.

Such a liquid crystalline polymer is elongated, flat, and has a molecular chain having high rigidity along its long axis.
A lyotropic liquid crystalline polymer is a liquid crystalline polymer that, when dissolved in a solvent, becomes a liquid crystal state exhibiting optical anisotropy in a certain concentration range. Specific examples of the lyotropic liquid crystalline polymer include liquid crystalline polyimide and liquid crystalline polyamide.

Among the above liquid crystalline polymers, the abrasion-resistant resin sheet 11 preferably contains a cured product of a thermal liquid crystalline polymer or a liquid crystalline monomer. When the abrasion-resistant resin sheet 11 contains a cured product of a thermal liquid crystalline polymer or liquid crystalline monomer, the thermal liquid crystalline polymer or liquid crystalline monomer is heated by heating without using a solvent in the production process. It can be easily made into a liquid crystal state by melting.

  Specific examples of thermal liquid crystalline polymers include thermal liquid crystalline polyesters, thermal liquid crystalline polyester amides, thermal liquid crystalline polyester ethers, thermal liquid crystalline polyester carbonates, thermal liquid crystalline polyester imides, and liquid crystalline thermoplastic elastomers. It is done.

Examples of the thermal liquid crystalline polyester include (A) a thermal liquid crystalline aromatic polyester and (B) an aromatic polyester amide.
Among the above thermal liquid crystalline polymers, since an abrasion-resistant resin member having excellent abrasion resistance can be easily obtained, at least one selected from (A) aromatic polyester or (B) aromatic polyester amide, particularly ( A) It is preferable to use an aromatic polyester.

  (A) Thermal liquid crystalline aromatic polyester generally refers to those having a segment composed of an ester of an aromatic carboxylic acid and an aromatic alcohol. The thermal liquid crystalline aromatic polyester in the present embodiment has (1) a segment part that forms a liquid crystal phase is composed of an ester of an aromatic carboxylic acid and an aromatic alcohol, and a segment part that does not form a liquid crystal phase is aliphatic or fatty. Those composed of esters of cyclic acids and alcohols, (2) segments in which the segment portion forming the liquid crystal phase is composed of esters of aliphatic or alicyclic acids and alcohols and does not form a liquid crystal phase Part composed of ester of aromatic carboxylic acid and aromatic alcohol, (3) Segment part forming liquid crystal phase composed of ester of aromatic carboxylic acid and aromatic alcohol, not forming liquid crystal phase The segment part is composed of an ester of an aliphatic or alicyclic acid and an aromatic alcohol, and (4) forms a liquid crystal phase Segment part composed of an ester of an aromatic carboxylic acid and an aromatic alcohol, and a segment part not forming a liquid crystal phase composed of an ester of an aliphatic or alicyclic alcohol and an aromatic carboxylic acid Is mentioned.

  The components of the thermal liquid crystalline aromatic polyester include (a) an aromatic dicarboxylic acid compound or alicyclic dicarboxylic acid compound, (b) an aromatic hydroxycarboxylic acid compound, (c) an aromatic diol, a fat Aromatic diol-based or alicyclic diol-based compound, (d) aromatic dithiol-based, aromatic thiophenol-based or aromatic thiolcarboxylic acid-based compound, (e) aromatic hydroxyamine or aromatic diamine-based compound, etc. It is done. The thermal liquid crystalline aromatic polyester may be composed of any one of these components (a) to (e), but preferably (a) and (c), (a) and (d), ( Several components are combined such as a), (b) and (c), (a), (b) and (e), (a), (b), (c) and (e), etc. Composed.

  Examples of the aromatic dicarboxylic acid compound (a) include aromatic dicarboxylic acids and derivatives thereof. Aromatic dicarboxylic acids include terephthalic acid, 4,4'-diphenyldicarboxylic acid, 4,4'-triphenyldicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 2,7-naphthalene Dicarboxylic acid, diphenyl ether-4,4'-dicarboxylic acid, diphenoxyethane-4,4'-dicarboxylic acid, diphenoxybutane-4,4'-dicarboxylic acid, diphenylethane-4,4'-dicarboxylic acid, isophthalic acid , Diphenyl ether-3,3'-dicarboxylic acid, diphenoxyethane-3,3'-dicarboxylic acid, diphenylethane-3,3'-dicarboxylic acid, 1,6-naphthalenedicarboxylic acid and the like. Aromatic dicarboxylic acid derivatives are those in which substituents such as alkyl, alkoxy and halogen are introduced into aromatic dicarboxylic acid, and include chloroterephthalic acid, dichloroterephthalic acid, bromoterephthalic acid, methylterephthalic acid, dimethylterephthalic acid, ethyl Examples include terephthalic acid, methoxyterephthalic acid, and ethoxyterephthalic acid.

  Examples of the alicyclic dicarboxylic acid compound (a) include alicyclic dicarboxylic acids and derivatives thereof. Examples of the alicyclic dicarboxylic acid include trans-1,4-cyclohexanedicarboxylic acid, cis-1,4-cyclohexanedicarboxylic acid, and 1,3-cyclohexanedicarboxylic acid. The alicyclic dicarboxylic acid derivative is obtained by introducing a substituent such as alkyl, alkoxy, halogen or the like into the alicyclic dicarboxylic acid, and trans-1,4- (2-methyl) cyclohexanedicarboxylic acid trans-1,4. -(2-Chloro) cyclohexanedicarboxylic acid and the like.

  Examples of the aromatic hydroxycarboxylic acid compound (b) include aromatic hydroxycarboxylic acids and derivatives thereof. Examples of the aromatic hydroxycarboxylic acid include aromatic hydroxycarboxylic acids such as 4-hydroxybenzoic acid, 3-hydroxybenzoic acid, 6-hydroxy-2-naphthoic acid, and 6-hydroxy-1-naphthoic acid. The aromatic hydroxycarboxylic acid derivative is a compound in which a substituent such as alkyl, alkoxy, halogen or the like is introduced into the aromatic hydroxycarboxylic acid, and includes 3-methyl-4-hydroxybenzoic acid, 3,5-dimethyl-4-hydroxy Benzoic acid, 2,6-dimethyl-4-hydroxybenzoic acid, 3-methoxy-4-hydroxybenzoic acid, 3,5-dimethoxy-4-hydroxybenzoic acid, 6-hydroxy-5-methyl-2-naphthoic acid, 6-hydroxy-5-methoxy-2-naphthoic acid, 2-chloro-4-hydroxybenzoic acid, 3-chloro-4-hydroxybenzoic acid, 2,3-dichloro-4-hydroxybenzoic acid, 3,5-dichloro -4-hydroxybenzoic acid, 2,5-dichloro-4-hydroxybenzoic acid, 3-bromo-4-hydroxybenzoic acid, 6-hydro Shi-5-chloro-2-naphthoic acid, 6-hydroxy-7-chloro-2-naphthoic acid, 6-hydroxy-5,7-dichloro-2-naphthoic acid.

  Examples of the aromatic diol compound (c) include aromatic diols and derivatives thereof. Aromatic diols include 4,4'-dihydroxydiphenyl, 3,3'-dihydroxydiphenyl, 4,4'-dihydroxytriphenyl, hydroquinone, resorcin, 2,6-naphthalenediol, 4,4'-dihydroxydiphenyl ether, Bis (4-hydroxyphenoxy) ethane, 3,3′-dihydroxydiphenyl ether, 1,6-naphthalenediol, 2,2-bis (4-hydroxyphenyl) propane, bis (4-hydroxyphenyl) methane and the like can be mentioned. Aromatic diol derivatives are those obtained by introducing substituents such as alkyl, alkoxy, halogen, etc. into aromatic diols, such as chlorohydroquinone, methylhydroquinone, t-butylhydroquinone, phenylhydroquinone, methoxyhydroquinone, phenoxyhydroquinone, 4-chloro. Resorcin, 4-methylresorcin, etc. are mentioned.

  Examples of the alicyclic diol compound (c) include alicyclic diols and derivatives thereof. Examples of the alicyclic diol include trans-1,4-cyclohexanediol, cis-1,4-cyclohexanediol, trans-1,4-cyclohexanedimethanol, cis-1,4-cyclohexanedimethanol, and trans-1,3. -Cyclohexanediol, cis-1,2-cyclohexanediol, trans-1,3-cyclohexanedimethanol and the like. The alicyclic diol derivative is obtained by introducing a substituent such as alkyl, alkoxy, halogen or the like into the alicyclic diol, and trans-1,4- (2-methyl) cyclohexanediol, trans-1,4- ( 2-chloro) cyclohexanediol and the like.

  Examples of the aliphatic diol compound (c) include linear or branched aliphatic diols such as ethylene glycol, 1,3-propanediol, 1,4-butanediol, and neopentyl glycol.

Examples of the aromatic dithiol compound (d) include benzene-1,4-dithiol, benzene-1,3-dithiol, 2,6-naphthalene-dithiol, 2,7-naphthalene-dithiol, and the like.

Examples of the aromatic thiophenol compound (d) include 4-mercaptophenol, 3-mercaptophenol, and 6-mercaptophenol.
Examples of the aromatic thiolcarboxylic acid compound (d) include 4-mercaptobenzoic acid, 3-mercaptobenzoic acid, 6-mercapto-2-naphthoic acid, 7-mercapto-2-naphthoic acid and the like.

  Examples of the aromatic hydroxyamine compound (e) include 4-aminophenol, N-methyl-4-aminophenol, 3-aminophenol, 3-methyl-4-aminophenol, 2-chloro-4-aminophenol, 4 -Amino-1-naphthol, 4-amino-4'-hydroxydiphenyl, 4-amino-4'-hydroxydiphenyl ether, 4-amino-4'-hydroxydiphenylmethane, 4-amino-4'-hydroxydiphenyl sulfide, 4, 4'-ethylenedianiline etc. are mentioned.

  As aromatic diamine compounds (e), 1,4-phenylenediamine, N-methyl-1,4-phenylenediamine, N, N'-dimethyl-1,4-phenylenediamine, 4,4'-diaminophenyl Sulfide (thiodianiline), 4,4'-diaminodiphenylsulfone, 2,5-diaminotoluene, 4,4'-diaminodiphenoxyethane, 4,4'-diaminodiphenylmethane (methylenedianiline), 4,4'-diamino And diphenyl ether (oxydianiline).

  (B) As an aromatic polyester amide, two or more kinds selected from aromatic diamine, aromatic dicarboxylic acid, aromatic diol, aromatic aminocarboxylic acid, aromatic oxycarboxylic acid, aromatic oxyamino compound and derivatives thereof Those that can be combined from the above components are mentioned.

  The liquid crystalline monomer constituting the cured product of the liquid crystalline monomer contains a mesogenic group. Examples of mesogenic groups include azomethine, biphenyl, cyanobiphenyl, terphenyl, cyanoterphenyl, phenylbenzoate, azobenzene, azoxybenzene, stilbene, phenylcyclohexyl, biphenylcyclohexyl, phenoxyphenyl, benzylideneaniline, benzylbenzoate, phenylpyrimidine, Examples thereof include phenyldioxane, benzoylaniline, and derivatives thereof such as tolan. The liquid crystalline monomer may contain two or more mesogenic groups. In that case, there is a flexible structure called a bent chain (spacer) composed of an aliphatic hydrocarbon group, aliphatic ether group, aliphatic ester group, siloxane bond, etc. between the mesogenic group and the mesogenic group. You may do it. Further, a small amount of a monomer that does not contain a mesogenic group in the molecule can be blended to such an extent that the effects of the present invention are not impaired.

  Specific examples of the liquid crystalline monomer include liquid crystalline epoxy, liquid crystalline (meth) acrylic ester, liquid crystalline isocyanate, liquid crystalline vinyl, liquid crystalline amine, liquid crystalline phenol, liquid crystalline diol, liquid crystalline dicarboxylic acid, and the like. . Among these liquid crystalline monomers, it is preferable to use liquid crystalline epoxy because an abrasion resistant resin member having excellent abrasion resistance can be easily obtained.

In order to cure the liquid crystalline epoxy, a cationic polymerization, a photocuring reaction in which ultraviolet rays are irradiated in a liquid crystal state and radical polymerization may be used, or a thermosetting reaction that is crosslinked by heating may be used. Curing agents used for the thermosetting reaction include amine curing agents, acid anhydride curing agents, phenol curing agents, latent curing agents, polymercaptan curing agents, polyamideimide curing agents, isocyanates, block isocyanates, etc. These curing agents may be used in combination of two or more. A curing agent containing a mesogenic group in the molecule may be used. Moreover, you may self-polymerize an epoxy group, without using a hardening | curing agent.

<Liquid crystal composition>
The abrasion-resistant resin sheet 11 of the present invention is formed from a liquid crystalline composition containing the liquid crystalline polymer or liquid crystalline monomer described above.

  In the liquid crystalline composition, a small amount of other polymers can be blended for the purpose of improving wear resistance, heat resistance, molding processability and the like. Other polymers include fluororesins such as polytetrafluoroethylene, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polyarylate, polyester carbonate, polycarbonate, polyimide, polyetherimide, polyamide, polyurethane, and polyester. Elastomer, polystyrene, acrylic polymer, polysulfone, silicone polymer, halogen polymer, olefin polymer and the like can be mentioned.

  In addition, for liquid crystalline compositions, pigments, dyes, fluorescent brighteners, dispersants, stabilizers, ultraviolet absorbers, energy quenchers, antistatic agents, antioxidants, flame retardants, and heat stabilizers as necessary. It is also possible to add a small amount of a plasticizer, a solvent or the like.

  Furthermore, an appropriate amount of an abrasion resistance improver can be added to the liquid crystalline composition in order to improve the abrasion resistance of the resulting abrasion resistant resin member. Such wear resistance improvers include natural graphite, artificial graphite, spherical graphite particles, glassy carbon, tungsten disulfide, molybdenum disulfide, phosphate, alumina, silicon carbide (SiC), boron nitride (BN). And glass fiber. The compounding amount of these wear resistance improvers is preferably less than 100 parts by weight with respect to 100 parts by weight of the liquid crystalline polymer. More preferably, it is less than 70 weight part, More preferably, it is less than 50 weight part. There exists a possibility that the moldability of a liquid crystalline composition may deteriorate that this compounding quantity is 100 weight part or more with respect to 100 weight part of liquid crystalline polymer. Moreover, it is also conceivable that the specific gravity of the obtained wear-resistant resin member is increased and hinders weight reduction. When weight reduction is required, it is preferable that the liquid crystalline composition does not substantially contain an abrasion resistance improver.

  When a lyotropic liquid crystalline polymer is used as the liquid crystalline polymer, a solvent for dissolving the lyotropic liquid crystalline polymer is added to the liquid crystalline composition. Such a solvent will not be specifically limited if the lyotropic liquid crystalline polymer to be used melt | dissolves. In addition, when an abrasion resistance improver is added to the liquid crystalline composition, the solvent also serves as a dispersion medium for the abrasion resistance improver, and therefore should be selected in consideration of the dispersibility of the abrasion resistance improver. Is preferred. The amount of the solvent is set to an amount that the lyotropic liquid crystalline polymer exhibits a liquid crystal state.

<Orientation degree α>
In order to obtain the orientation degree α of the molecular chain of the liquid crystalline polymer in the wear-resistant resin sheet 11, wide-angle X-ray diffraction measurement (transmission) is performed on the wear-resistant resin sheet 11. In an X-ray diffractometer, when a sample is irradiated with X-rays, a concentric arc-shaped diffraction pattern (Debye ring) is obtained when the particles (molecular chains) contained in the sample are oriented. Therefore, in order to determine the orientation degree α of the molecular chain of the liquid crystalline polymer in the wear resistant resin sheet 11, the orientation direction of the molecular chain of the liquid crystalline polymer in the wear resistant resin sheet 11 (Z axis in FIG. 1). The surface along the direction) is irradiated with X-rays to obtain a concentric arc Debye ring. Next, a diffraction pattern showing an X-ray diffraction intensity distribution in the radial direction from the center of the Debye ring is obtained (see FIG. 5). In this diffraction pattern, the horizontal axis represents an angle 2θ that is twice the X-ray diffraction angle θ, and the peak confirmed at a position of 2θ = 20 degrees represents the distance between the molecular chains of the liquid crystalline polymer. It is considered.

  The angle of the diffraction peak (peak scattering angle) of the liquid crystalline polymer may be in the range of about 15 to 30 degrees depending on the structure of the liquid crystalline polymer and the composition of the liquid crystalline polymer composition. Appears around 20 degrees. By fixing the angle (peak scattering angle) at which this diffraction peak was obtained and measuring the X-ray diffraction intensity distribution from 0 ° to 360 ° in the azimuth angle direction (circumferential direction of the Debye ring), FIG. An X-ray diffraction intensity distribution in the azimuth direction as shown is obtained. The steeper peak in the intensity distribution indicates that the molecular chains of the liquid crystalline polymer are highly oriented in a certain direction. Accordingly, in this intensity distribution in the azimuth direction, the width (half width Δβ) at the half height of the peak height is obtained, and the half width Δβ is substituted into the above formula (1), whereby the molecules of the liquid crystalline polymer are obtained. The degree of chain orientation α can be calculated. In the case of the intensity distribution in the azimuth direction shown in FIG. 6, the orientation degree α is 0.90.

  In the wear-resistant resin member of the present invention, the range of the orientation degree α is 0.5 or more and less than 1.0, preferably 0.55 or more and less than 1.0, more preferably 0.6 or more and less than 1.0. Preferably it is 0.7 or more and less than 1.0. In the wear-resistant resin member, when the degree of orientation α is less than 0.5, sufficient wear resistance cannot be obtained on the surface intersecting the orientation direction. On the other hand, since the half-value width Δβ always shows a positive value, the degree of orientation α cannot take a value of 1.0 or more from the above equation (1).

<Manufacturing method>
Next, a method for forming an abrasion-resistant resin member from a thermal liquid crystalline composition containing a liquid crystalline polymer will be described.

  In the case where a thermal liquid crystalline polymer is used as the liquid crystalline polymer, first, the liquid crystalline composition containing the thermal liquid crystalline polymer is heated and melted in a molding apparatus to thereby convert the thermal liquid crystalline polymer into a liquid crystal. Put it in a state. Next, while maintaining the liquid crystalline state of the thermal liquid crystalline polymer, the direction in which the molecular chain of the thermal liquid crystalline polymer in the liquid crystalline composition intersects at least one surface of the obtained resin member, preferably Orient in the orthogonal direction. Next, while maintaining the oriented state of the thermal liquid crystalline polymer, the liquid crystalline composition is cooled and solidified to cause a phase transition from the liquid crystalline state to the solid state, whereby at least one molecular chain of the thermal liquid crystalline polymer is formed. A wear-resistant resin member oriented in the direction intersecting the two surfaces can be obtained.

  When the liquid crystalline polymer is a cured product of the liquid crystalline monomer formed from the liquid crystalline monomer, first, in the molding apparatus, the liquid crystalline composition containing only the liquid crystalline monomer or a mixture of the liquid crystalline monomer and the curing agent. The object is heated and melted to a liquid crystal state. Next, with the liquid crystalline monomer in the liquid crystalline composition kept in a liquid crystal state, the molecular chain of the liquid crystalline monomer is aligned in a direction intersecting at least one surface of the obtained resin member, preferably in a perpendicular direction. . Next, while maintaining the aligned state of the liquid crystalline monomer, the liquid crystalline monomer in the liquid crystalline composition is polymerized and cured by a crosslinking reaction or a polymerization reaction so that the molecular chain of the liquid crystalline polymer is at least A wear-resistant resin member oriented in a direction intersecting one surface can be obtained.

  When a lyotropic liquid crystalline polymer is used as the liquid crystalline polymer, first, a liquid crystalline composition containing the lyotropic liquid crystalline polymer at a concentration exhibiting liquid crystallinity is prepared. Next, while maintaining the liquid crystal state of the lyotropic liquid crystalline polymer, the liquid crystalline composition is molded by a molding apparatus and intersects with at least one surface of a resin member from which a molecular chain of the lyotropic liquid crystalline polymer can be obtained. , Preferably oriented in an orthogonal direction. Then, while maintaining the state in which the lyotropic liquid crystalline polymer is aligned, the solvent is removed from the liquid crystalline composition by volatilization or the like, thereby causing the lyotropic liquid crystalline polymer to undergo a phase transition from the liquid crystal state to the solid state, thereby Thus, it is possible to obtain a wear-resistant resin member in which the molecular chains of the liquid crystalline polymer are aligned in a direction intersecting at least one surface.

Examples of the method for aligning the liquid crystalline polymer include an alignment method using at least one field selected from a flow field, a shear field, a magnetic field, and an electric field.
Among these alignment methods, it is preferable to use an alignment method using a magnetic field because the alignment direction and the alignment degree can be easily controlled. By applying a magnetic field to the liquid crystal polymer or monomer in the liquid crystal state, the rigid molecular chain of the liquid crystal polymer or monomer can be aligned in a direction parallel to the magnetic field lines. Here, by adjusting the magnetic flux density of the magnetic field, the application time of the magnetic field, and the like, it is possible to easily adjust the orientation degree α of the liquid crystalline polymer in the range of 0.5 or more and less than 1.0.

  Examples of the magnetic field generator that generates a magnetic field include a permanent magnet, an electromagnet, a superconducting magnet, and a coil. Among these magnetic field generators, a superconducting magnet is preferable because a magnetic field having a high magnetic flux density can be generated.

  The magnetic flux density of the magnetic field applied to the liquid crystalline composition is preferably 1 to 20 Tesla (T), more preferably 2 to 20 T when aligning the thermal liquid crystalline polymer and the lyotropic liquid crystalline polymer. Preferably it is 3-20T. If the magnetic flux density is less than 1T, the rigid molecular chain of the liquid crystalline polymer may not be sufficiently aligned. On the other hand, a magnetic field having a magnetic flux density exceeding 20T is difficult to obtain in practice. Similarly, when aligning a liquid crystalline monomer, Preferably it is 0.2-20T, More preferably, it is 0.5-15T, More preferably, it is 1-10T.

  As the molding apparatus, an apparatus for molding a synthetic resin such as an injection molding apparatus, an extrusion molding apparatus, a press molding apparatus, a blow molding apparatus, a transfer molding apparatus, or a calendar molding apparatus can be used. The liquid crystalline composition can be formed into a wear-resistant resin member having various shapes such as a sheet shape, a block shape, and a cylindrical shape.

  Hereinafter, as an example, a method for producing the abrasion-resistant resin sheet 11 shown in FIG. 1 from a liquid crystalline composition containing a thermal liquid crystalline polymer as the liquid crystalline polymer will be described in more detail based on FIG. To do.

  As shown in FIG. 2, the apparatus for manufacturing the abrasion-resistant resin sheet 11 includes a mold 12a having a cavity 13a having a shape corresponding to the shape of the abrasion-resistant resin sheet 11, and upper and lower portions of the mold 12a. And permanent magnets 14a respectively disposed thereon. The magnetic field lines M of the magnetic field generated by the permanent magnet 14a coincide with the depth direction of the cavity 13a.

  First, the cavity 13a is filled with a liquid crystalline composition 15 containing a thermal liquid crystalline polymer. The mold 12a is provided with a heating device (not shown), and the thermal liquid crystalline polymer contained in the liquid crystalline composition 15 in the cavity 13a is maintained in a molten state by the heating device. Next, a magnetic field having a predetermined magnetic flux density is applied to the liquid crystalline composition 15 in the cavity 13a by the permanent magnet 14a. At this time, the magnetic lines of force M1 coincide with the thickness direction of the liquid crystalline composition 15 in the cavity 13a, so that the rigid molecular chain of the thermal liquid crystalline polymer is aligned in the thickness direction of the liquid crystalline composition 15. While maintaining this alignment state, the liquid crystalline composition 15 is cooled and solidified and taken out from the mold 12a. Thereby, the abrasion-resistant resin sheet 11 in which the rigid molecular chains of the thermal liquid crystalline polymer are oriented in the thickness direction can be obtained.

In the above embodiment, the method for producing the wear-resistant resin sheet 11 having a flat surface requiring wear resistance has been described in detail, but the surface requiring wear resistance is a curved surface (for example, a spherical surface). It is also possible to form a wear-resistant resin member. For example, a bowl-shaped wear-resistant resin member can be formed by an apparatus as shown in FIGS. The apparatus includes a mold 12b having a cavity 13b having a shape corresponding to a desired bowl-shaped member, an S-pole permanent magnet 14c having a concave surface along the lower surface of the mold 12b, and a mold 12b. , And a substantially conical N-pole permanent magnet 14b having a tip opposed to the permanent magnet 14c. In such an apparatus, as indicated by the broken line in FIG. 4, the magnetic field lines M are radial from the tip of the N-pole permanent magnet 14b toward the S-pole permanent magnet 14c, that is, the spherical bottom surface of the cavity 13b. It extends in a direction orthogonal to. Therefore, the molecular chains of the liquid crystalline polymer contained in the liquid crystalline composition 15 in the cavity 13b are also aligned in this direction. As a result, it is possible to obtain an abrasion-resistant resin member in which the molecular chains of the liquid crystalline polymer are aligned in a direction perpendicular to the spherical surface of the bowl-shaped resin member.

  The wear-resistant resin member of the present invention can be used for resin members that require wear resistance on contact surfaces with other members, such as gears, bearings, joints, keyboards, chassis, brake pads, and semiconductor wafer carriers.

The effects exhibited by the above embodiment will be described below.
The wear-resistant resin member of the present invention contains a liquid crystalline polymer, and the molecular chain of the liquid crystalline polymer is oriented in a direction intersecting at least one surface of the member. Thereby, the wear-resistant resin member can exhibit excellent wear resistance on the surface.

  In one embodiment, the orientation degree α of the molecular chain of the liquid crystalline polymer is 0.5 or more and less than 1.0. By setting the orientation degree α of the liquid crystalline polymer within the above range, the liquid crystalline polymer chain is more highly oriented, and as a result, the surface intersecting with the molecular chain of the oriented liquid crystalline polymer is more Excellent wear resistance can be exhibited.

  -In one Embodiment, an abrasion-resistant resin member is formed from the liquid crystalline composition containing a liquid crystalline polymer or a liquid crystalline monomer. In this case, the molecular chains are aligned while maintaining the liquid crystalline polymer or liquid crystalline monomer in the liquid crystalline composition in a liquid crystal state. Therefore, since the liquid crystalline polymer is more highly oriented, it is possible to easily obtain a wear resistant resin member having better wear resistance on the surface that intersects the orientation direction.

  In the above embodiment, when the liquid crystalline polymer or liquid crystalline monomer is a thermal liquid crystalline, the liquid crystallinity can be controlled by temperature, so there is no need to use a solvent, and it is easier to wear. It is possible to obtain a functional resin member.

  In one embodiment, the wear resistant resin member is formed from a thermal liquid crystalline polymer of either (A) aromatic polyester or (B) aromatic polyester amide. When comprised in this way, the liquid crystal phase of those thermo-liquid crystalline polymers can be expressed easily. Further, these thermo-liquid crystalline polymers have good moldability and can be easily molded into various shapes. Therefore, it is possible to obtain a wear-resistant resin member that is easy to mold and that has a highly oriented thermal liquid crystalline polymer and that has excellent wear resistance.

  -In one Embodiment, a liquid crystalline composition contains liquid crystalline epoxy as a liquid crystalline monomer. In this case, such a liquid crystal composition can easily develop a liquid crystal phase. Furthermore, since such a liquid crystalline composition is a low-viscosity liquid, it has good moldability. Therefore, it is easy to mold, and a highly wearable resin having excellent wear resistance in which a liquid crystalline polymer is highly oriented by highly aligning and curing the liquid crystalline monomer in the liquid crystalline composition. A member is obtained.

-In the abrasion-resistant resin member of this invention, the abrasion resistance is improved by orienting the molecular chain of a liquid crystalline polymer. Therefore, in the case of further improving the wear resistance by using the wear resistance improver in combination, the content of the wear resistance improver is 1 with respect to 100 parts by weight of the liquid crystalline polymer.
Even if it is less than 00 parts by weight, high wear resistance can be obtained. Therefore, it is possible to reduce the weight of the obtained wear-resistant resin member.

  In the wear-resistant resin member of one embodiment, a rigid magnetic chain of the liquid crystalline polymer or liquid crystalline monomer is applied to the liquid crystalline polymer or liquid crystalline monomer by applying a magnetic field to the liquid crystalline polymer or liquid crystalline monomer. Oriented in a direction perpendicular to the surface. In this case, the liquid crystalline polymer can be easily oriented, and an abrasion-resistant resin member having excellent abrasion resistance can be easily obtained. In addition, the orientation direction of the liquid crystalline polymer can be easily controlled by the direction of the magnetic field lines of the applied magnetic field. It is possible to align them as follows.

The above embodiment can be modified as follows.
・ In order to improve the elastic modulus, etc., filler improvers such as organic fibers such as glass fiber, carbon fiber, and aramid fiber, metal fibers, and inorganic fibers are blended in the liquid crystalline composition so as not to impair the effects of the present invention. May be.

The permanent magnets 14a and 14b are arranged in pairs so as to sandwich the mold 12a, but one of the permanent magnets 14a and 14b may be omitted.
The permanent magnets 14a and 14b are arranged in pairs so that the S pole and the N pole face each other, but may be arranged so that the S poles or the N poles face each other. .

  ・ In the wear-resistant resin member, even when there are multiple surfaces where wear resistance is required, by arranging the magnetic field generator so that the magnetic lines of force pass in directions orthogonal to each surface, the multiple It is possible to obtain a wear-resistant resin member in which molecular chains of liquid crystalline polymers are oriented in a direction perpendicular to the surface.

The magnetic field lines M are linear, but may be curved. Furthermore, you may rotate any one of the magnetic force line M and the metal mold | die 12a.
Next, the embodiment will be described more specifically with reference to examples and comparative examples.

(Example 1)
Pellets of aromatic polyester (i) (“Rodlan LC5000” manufactured by Unitika Ltd.) having a copolymerization ratio of 4-hydroxybenzoic acid / (terephthalic acid and ethylene glycol) = 80/20 mol% as the thermal liquid crystalline polymer The sheet was dehumidified and dried, and a sheet 20 mm long x 20 mm wide x 2 mm thick was produced by injection molding. This sheet was placed in a cavity 13a of a mold heated to 310 ° C., melted in a magnetic field having a magnetic flux density of 10 Tesla by a superconducting magnet, and then held in the same magnetic field for 15 minutes. Thereafter, the liquid crystalline composition 15 in the cavity 13a was cooled and solidified to room temperature, whereby the wear-resistant resin sheet 11 was produced. The direction of the lines of magnetic force was matched with the thickness direction of the wear-resistant resin sheet 11.

(Example 2)
As the thermal liquid crystalline polymer, aromatic polyester (ii) having a copolymerization ratio of 4-hydroxybenzoic acid / (terephthalic acid and ethylene glycol) = 60/40 mol% (“Rodlan LC3000” manufactured by Unitika Ltd.) is used. And the abrasion-resistant resin sheet 11 was produced similarly to Example 1 except having set the temperature of the metal mold | die 12a to 250 degreeC.

(Example 3)
A mixture in which 100 parts by weight of the same aromatic polyester (i) as in Example 1 was blended with 50 parts by weight of glassy carbon powder as an abrasion resistance improver was melt-kneaded by an extruder, and a pellet-like liquid crystalline composition Product 15 was obtained. This liquid crystalline composition 15 was dehumidified and dried, and a sheet having a length of 20 mm, a width of 20 mm, and a thickness of 2 mm was produced by injection molding. This sheet-like liquid crystalline composition 15 is placed in a cavity 13a of a mold 12a heated to 310 ° C., melted in a magnetic field having a magnetic flux density of 10 Tesla by a superconducting magnet, and then in the same magnetic field for 15 minutes. Retained. Thereafter, the liquid crystalline composition 15 in the cavity 13a was cooled and solidified to room temperature, whereby the wear-resistant resin sheet 11 was produced. The direction of the line of magnetic force was made to coincide with the thickness direction of the sheet-like molded body.

Example 4
1 mol of terephthalylidene-bis- (4-amino-3-methylphenol) diglycidyl ether having an azomethine group in the molecule as a liquid crystalline epoxy and 4,4′-diamino-1,2-diphenylethane as a curing agent : It mixed by the ratio of 0.5 mol, and prepared the liquid crystalline composition 15. Next, this liquid crystalline composition 15 was placed in the cavity 13a of the mold 12a heated to 170 ° C. After melting the liquid crystalline composition 15 in the cavity 13a in a magnetic field having a magnetic flux density of 10 Tesla by a superconducting magnet, the liquid crystalline composition 15 is cured by holding the liquid crystalline composition 15 in the same magnetic field for 10 minutes. A wear-resistant resin sheet 11 having a size of 20 mm × width 20 mm × thickness 2 mm was produced. The direction of the line of magnetic force was made to coincide with the thickness direction of the sheet-like molded body.

(Comparative Example 1)
A wear-resistant resin sheet 11 was produced in the same manner as in Example 1 except that the same aromatic polyester (i) as in Example 1 was used and molding was performed without applying a magnetic field during melting.

(Comparative Example 2)
A wear-resistant resin sheet 11 was produced in the same manner as in Example 2 except that the same aromatic polyester (ii) as in Example 2 was used and molding was performed without applying a magnetic field during melting.

(Comparative Example 3)
Similarly to Example 3, as the liquid crystalline composition 15, a mixture in which 50 parts by weight of glassy carbon powder as an abrasion resistance improver was blended with 100 parts by weight of the aromatic polyester (i) was used, and a magnetic field was applied during melting. Abrasion-resistant resin sheet 11 was produced in the same manner as in Example 3 except that it was molded without applying.

(Comparative Example 4)
As in Example 4, terephthalylidene-bis- (4-amino-3-methylphenol) diglycidyl ether having an azomethine group in the molecule as a liquid crystalline epoxy, and 4,4′-diamino-1,2 as a curing agent Abrasion resistance in the same manner as in Example 4 except that liquid crystalline composition 15 in which diphenylethane was mixed at a ratio of 1 mol: 0.5 mol was used and molding was performed without applying a magnetic field during melting. A resin sheet 11 was produced.

  The degree of orientation α in the thickness direction of each wear-resistant resin sheet 11 obtained in Examples 1 to 4 and Comparative Examples 1 to 4 was determined. The orientation degree α was calculated from the X-ray diffraction pattern of each wear-resistant resin sheet 11 measured by an X-ray diffractometer (“RINT RAPID” manufactured by Rigaku Corporation). As an example, FIG. 5 shows a diffraction pattern in the radial direction of the Debye ring by X-ray diffraction measurement of Example 1, and FIG. 6 shows an intensity distribution in the azimuth direction at a diffraction peak angle 2θ = 20 degrees. Further, FIG. 7 shows a diffraction pattern in the radial direction of the Debye ring by X-ray diffraction measurement of Comparative Example 1, and FIG. 8 shows an intensity distribution in the azimuth direction at a diffraction peak angle 2θ = 20 degrees.

About each abrasion-resistant resin sheet 11 obtained in Examples 1-4 and Comparative Examples 1-4, abrasion resistance was evaluated using the apparatus shown in FIG. In the apparatus shown in FIG. 9, polishing paper 16 having a particle size of 600 is arranged on an aluminum plate 17. Each wear-resistant resin sheet 11 (20 mm × 20 mm × 2 mm) is placed on the abrasive paper 16, and a 500 g weight 19 is placed on the wear-resistant resin sheet 11 via a fixing jig 18. In this state, the wear-resistant resin sheet 11 is polished with the abrasive paper 16 by reciprocatingly sliding the aluminum plate 17 in the direction of the arrow (stroke: 30 cm, number of times: 50 reciprocations). The mass difference between the abrasion-resistant resin member before and after polishing was measured to obtain the amount of wear (mg). Table 1 shows the orientation degree α and the wear amount of Examples 1 to 4 and Comparative Examples 1 to 4.

表１の結果から明らかなように、実施例１〜４の耐摩耗性シートでは、配向度αが０．７２〜０．９０を示し、液晶性高分子の分子鎖が高度に配向していることが分かる。このような耐摩耗性シートは、摩耗量が少なく、優れた耐摩耗性を有した。一方、比較例１〜４の耐摩耗性シートでは、配向度αが０となり、実施例と比較して、摩耗量が多く、耐摩耗性が不十分であった。

As is clear from the results in Table 1, in the wear-resistant sheets of Examples 1 to 4, the degree of orientation α is 0.72 to 0.90, and the molecular chains of the liquid crystalline polymer are highly oriented. I understand that. Such an abrasion-resistant sheet has a small amount of abrasion and has excellent abrasion resistance. On the other hand, in the wear resistant sheets of Comparative Examples 1 to 4, the degree of orientation α was 0, and the wear amount was large and the wear resistance was insufficient as compared with the Examples.

The perspective view which shows the abrasion resistant resin sheet in one Embodiment of this invention. The figure which shows the manufacturing method of the abrasion-resistant resin sheet which has high orientation degree (alpha) in the thickness direction. The figure which shows the apparatus for manufacturing the hook-shaped abrasion-resistant resin member in another embodiment of this invention. The figure which shows the method for manufacturing the hook-shaped abrasion-resistant resin member in another embodiment of this invention. The X-ray-diffraction pattern which shows X-ray-diffraction intensity distribution in the radial direction of the Debye ring of the abrasion-resistant resin sheet (Example 1) in one Embodiment of this invention. The graph which shows the X-ray-diffraction intensity distribution of the azimuth direction of the abrasion resistant resin sheet (Example 1) in one Embodiment of this invention. The diffraction pattern which shows the X-ray-diffraction intensity distribution of the radial direction of the Debye ring of the conventional abrasion-resistant resin sheet (comparative example 1). The graph which shows the X-ray-diffraction intensity distribution of the azimuth direction of the conventional abrasion-resistant resin sheet (comparative example 1). The figure which shows an abrasion-resistant evaluation apparatus.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11 ... Wear-resistant sheet | seat, 12a, 12b ... Metal mold | die, 13a, 13b ... Cavity, 14a, b, c ... Permanent magnet, 15 ... Liquid crystalline composition, 16 ... Polishing paper, 17 ... Aluminum plate, 18 ... For fixation Jig, 19: Weight, Δβ: Half width, M: Magnetic field line.

Claims (8)

  It is a resin member containing a liquid crystalline polymer, and in order to improve wear resistance, the molecular chain of the liquid crystalline polymer is aligned in a direction intersecting at least one surface of the resin member. A characteristic wear-resistant resin member. In the wear-resistant resin member, the orientation degree α of the liquid crystalline polymer obtained by the following formula (1) from the X-ray diffraction measurement of the member is in the range of 0.5 or more and less than 1.0.
Orientation degree α = (180−Δβ) / 180 (1)
In the above formula, Δβ represents a half width when an intensity distribution from 0 to 360 degrees in the azimuth angle direction is measured while fixing a peak scattering angle by X-ray diffraction measurement. Wear-resistant resin member.   The wear-resistant resin member according to claim 1, wherein the liquid crystalline polymer is a thermal liquid crystalline polymer.   The wear-resistant resin member according to claim 3, wherein the thermal liquid crystalline polymer is at least one selected from an aromatic polyester and an aromatic polyester amide.   The wear-resistant resin member according to claim 1 or 2, wherein the liquid crystalline polymer is a polymer obtained by crosslinking or polymerizing a liquid crystalline monomer.   The wear-resistant resin member according to claim 5, wherein the liquid crystalline monomer is a liquid crystalline epoxy resin. This is a method for producing an abrasion-resistant resin member containing a liquid crystalline polymer and having molecular chains of the liquid crystalline polymer aligned in a direction intersecting at least one surface in order to improve the abrasion resistance. And
A step of preparing a liquid crystalline composition containing either a liquid crystalline polymer or a liquid crystalline monomer;
A step of expressing liquid crystallinity of any of the liquid crystalline polymer and the liquid crystalline monomer in the liquid crystalline composition;
Applying a magnetic field to the liquid crystalline composition in a direction orthogonal to at least one surface thereof and orienting molecular chains of either the liquid crystalline polymer or the liquid crystalline monomer in the direction;
And solidifying the liquid crystalline composition while maintaining the orientation of the molecular chain.   The method according to claim 7, wherein the step of developing liquid crystallinity is performed by melting the liquid crystalline composition.

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