JPWO2006134805A1 - Polishing fibers and abrasives - Google Patents

Abstract

A fiber containing diamond particles and a hydrophilic resin is prepared, and the diamond particles have a hydrophilic group on the surface thereof. The diamond particles may be partially embedded in a hydrophilic resin, and the hydrophilic resin may cover 50% or more of the fiber surface. The average particle diameter of the diamond particles may be 1 μm or less. The diamond particles may have a hydrophilic group such as a hydroxyl group and may be particles obtained by decomposing and removing impurities from synthetic diamond obtained by an explosion method. An abrasive obtained by using such a polishing fiber is suitable for precision polishing because it hardly causes detachment of abrasive grains (diamond particles) due to polishing treatment and has high polishing ability.

Description

  The present invention relates to a polishing fiber suitable for surface polishing or cleaning of metal, synthetic resin, wood, stone, etc. and an abrasive using the same, and particularly in the electronic or optical field where high surface roughness is required. The present invention relates to a polishing fiber and an abrasive suitable for precision polishing of electronic / optical components (for example, silicon wafer, hard disk, magnetic head, optical fiber, ferrule, liquid crystal panel, etc.).

  Conventionally, for polishing and cleaning electronic parts and various materials (metals, synthetic resins, wood, stones, etc.), a polishing cloth with abrasive abrasive grains attached to the surface of a nonwoven fabric made of synthetic fibers has been used. I came. This polishing cloth is sprayed with a mixture of thermosetting resin (binding material) such as phenol resin, epoxy resin, urethane resin and abrasive abrasive grains such as alundum, carborundum, aluminum hydroxide, diamond, etc. It was manufactured by a method of curing a resin or a method of immersing the nonwoven fabric in the mixed solution and then curing the resin by taking it out of the solution.

  However, the polishing cloth obtained by these methods has a short abrasive life because the mixture of the binder and abrasive grains easily falls off the fiber surface, and the fiber-only part and the non-dropping part after the abrasive grains fall off. Since this causes uneven polishing, it was unsuitable for precise polishing.

  On the other hand, in precision polishing of silicon wafers, hard disk substrates, liquid crystal display panels and the like, a method of polishing by holding an abrasive slurry on a polishing pad made of polyurethane foam is widely performed. However, this method is uneconomical because the expensive abrasive slurry is in a dripping state, and it is difficult to maintain the slurry concentration uniformly for a long time. Furthermore, since the abrasive grains are clogged in the bubbles of the foam, it is necessary to periodically scrape and regenerate the pad surface.

  As a technique for solving these problems, Japanese Patent Application Laid-Open No. 3-55155 (Patent Document 1) discloses that a composite fiber composed of a water-soluble resin component containing abrasive grains and a low melting point resin component is processed into a nonwoven fabric. A polishing material has been proposed in which a thermosetting resin that may contain abrasive grains is fixed to a non-woven fabric in which the low-melting-point resin component is heat-sealed. This document describes the use of inorganic abrasive grains such as alundum, carbon random, aluminum hydroxide and diamond as abrasive grains.

  However, with this abrasive, the grain size of the abrasive grains to be used is originally large, or the abrasive grains are aggregated due to insufficient dispersion of the abrasive grains in the resin, and abrasive grains having a size exceeding 1 μm are formed on the fiber surface. Exposed to. Therefore, in a fiber manufacturing process and a polishing cloth manufacturing process, processing machines such as a spinning machine, a card machine, and a loom are easily worn and damaged, and abrasive grains easily fall off from the fiber surface during the polishing operation. Furthermore, when water is used for polishing, since the resin constituting the fiber is water-soluble, the nonwoven fabric dissolves and may not have a function as an abrasive.

  Among such problems, as a method for solving the problem of processability, for example, JP-A-60-21966 (Patent Document 2) discloses a polishing layer made of a granular abrasive-containing polymer as an abrasive. A method for producing a polishing fiber is disclosed in which at least a part of the coating layer is dissolved or decomposed and removed by a solvent or a decomposing agent from the composite fiber coated with a coating layer containing no slag. In this document, the particle size of a granular abrasive such as diamond is most preferably 20 μm or less, about 1 to 100 μm is used for medium polishing, and about 0.01 to 3 μm is used for high-precision finish polishing. Are listed.

  Japanese Patent Application Laid-Open No. 10-245720 (Patent Document 3) includes an island component composed of a first component made of a thermoplastic resin containing abrasive abrasive grains and a second component made of a different kind of thermoplastic resin. Disclosed is a split type composite fiber that is 95% or more of the second component exposed to the fiber surface.

  In JP-A-2001-98425 (Patent Document 4), in the core-sheath type bicomponent composite fiber, the core sheath is also made of a thermoplastic polymer, the core component contains inorganic particles having an average particle diameter of 0.1 to 4 μm, and fracture occurs. An abrasive composite fiber having a point strength of 2.1 cN / dtex or more is disclosed.

However, these fibers are insufficient in strength, or the fibers after splitting contain fibers that do not contain abrasive grains, so that the polishing efficiency is low, and further, the abrasive grains easily fall off from the fibers during the polishing operation. Has drawbacks.
JP-A-3-55155 (Claims, page 2, upper right column, lines 16 to 19) JP-A-60-21966 (Claims, page 2, upper right column, line 4 to lower left column, line 9) Japanese Patent Laid-Open No. 10-245720 (Claim 1) JP 2001-98425 A (Claim 1)

  An object of the present invention is to provide a polishing fiber that has almost no loss of abrasive grains (diamond particles, etc.) due to polishing treatment and has high polishing ability, and an abrasive using the fiber.

  Another object of the present invention is to provide a polishing fiber capable of suppressing wear and damage of a processing machine in the fiberizing process, improving productivity, and capable of precise polishing, and an abrasive using the fiber. It is in.

  Still another object of the present invention is to provide an abrasive fiber having high mechanical properties such as strength and an abrasive using the fiber.

  Another object of the present invention is to provide a uniform and well-ground abrasive suitable for precision polishing.

  In order to solve the above-mentioned problems, the present inventors have intensively studied. As a result of combining diamond particles having hydrophilicity and a hydrophilic resin, the abrasive grains (diamond particles) are almost removed by polishing treatment. And the present invention has been completed.

  That is, the polishing fiber of the present invention is a fiber containing diamond particles and a hydrophilic resin, and the diamond particles have a hydrophilic group on the surface. In this fiber, the diamond particles may be partially embedded in the hydrophilic resin, and the hydrophilic resin may cover 50% or more of the fiber surface. The diamond particles may have an average particle size of 1 μm or less. The hydrophilic group may be a carboxyl group, a carbonyl group, an amino group, a hydroxyl group, a sulfonyl group, a nitric acid group, a nitrous acid group, or the like. The diamond particles may be particles obtained by decomposing and removing impurities from synthetic diamond obtained by an explosion method. The hydrophilic resin may be a vinyl resin and / or a polyamide resin. The polishing fiber of the present invention may be a core-sheath type composite fiber having a sheath part made of a hydrophilic resin containing diamond particles. In this core-sheath type composite fiber, the core part may be composed of a thermotropic liquid crystal polymer. The average fiber diameter of the polishing fiber of the present invention may be 1 dtex or less.

  The present invention also includes an abrasive containing the polishing fiber. In this abrasive, the average particle diameter of the diamond particles may be 1 μm or less. Such an abrasive is suitable for precision polishing.

  In the present invention, since diamond particles having hydrophilicity are used as abrasive grains and combined with a hydrophilic resin, the abrasive grains (diamond particles) are hardly dropped by the polishing treatment. That is, it is possible to reduce the abrasive grains falling off the fiber surface during the polishing operation. Moreover, it has excellent polishing ability and can be precisely polished. Furthermore, wear and damage of the processing machine in the fiberizing process can be suppressed, and productivity can be improved. In addition, mechanical properties such as strength are high. Therefore, when an abrasive obtained from such a polishing fiber is used for polishing, abrasive grains can be used effectively, and a reduction in polishing cost can be expected. Furthermore, the abrasive of the present invention is uniform and has a good texture and is suitable for precision polishing.

Detailed Description of the Invention

  Next, the present invention will be described in detail. The polishing fiber of the present invention contains hydrophilic diamond particles and a hydrophilic resin. The diamond particles may have a hydrophilic group on the surface. In particular, both are highly compatible, and diamond particles are contained in the hydrophilic resin.

(Diamond particles)
In the present invention, diamond particles are used as abrasive grains (abrasive abrasive grains) of the polishing fibers. The particle diameter of the diamond particles is preferably smaller in view of suppressing polishing unevenness and scratches and enabling precise polishing. Specifically, the average particle diameter of the diamond particles may be 1 μm or less (for example, 0.003 to 1 μm), for example, 0.8 μm or less (for example, 0.005 to 0.8 μm), preferably 0. It may be 0.5 μm or less (for example, 0.01 to 0.5 μm), more preferably 0.3 μm or less (for example, 0.05 to 0.3 μm). The particle diameter of the diamond particles may be agglomerated or pulverized in the manufacturing process, but the particle diameter is a particle diameter in a state existing in the fiber (that is, a particle diameter when processed into a fiber). Diamond particles can be observed by enlarging the fiber surface with an electron microscope about 3000 times, but most of them are not true spheres, so they are expressed as sizes when converted into spheres. A method for measuring the particle size of the diamond particles in the state existing in the fiber will be described later. In addition, when a particle size is too small, a handleability and a grinding | polishing effect will fall.

The diamond particles used in the present invention have a hydrophilic group on the surface. When the surface of the diamond particles is hydrophobic, the compatibility with the hydrophilic resin containing the diamond particles is reduced, and the particle size may agglomerate to a size exceeding 1 μm. Diamond particles can easily fall off the resin and are not suitable for precision polishing. Examples of the hydrophilic group include a carboxyl group, a carbonyl group, an amino group, a hydroxyl group, a sulfonyl group, a nitric acid group, and a nitrous acid group. These hydrophilic groups may be groups derived from these hydrophilic groups (for example, quaternary ammonium bases such as alkyl ammonium halides, carbamoyl groups, —NHCONH ₂ groups, —OSO ₃ H groups, etc.). Furthermore, these hydrophilic groups may be in the form of a salt (for example, an alkali metal salt such as sodium or a base such as ammonia). Among these hydrophilic groups, plural kinds of hydrophilic groups may exist on the particle surface. Especially, the diamond particle which has a hydroxyl group is preferable at the point of easiness of manufacture, and the difficulty of dropping off of an abrasive grain.

  The diamond particles used in the present invention may be either natural or synthetic, but synthetic diamond produced by an explosion method is preferred from the viewpoint of economy. The hydrophilicity of the diamond particles and the hydrophilic groups on the surface are, for example, diamonds containing impurities (carbon components that have not been completely diamondized) obtained by the explosion method, acids such as sulfuric acid, nitric acid, hydrochloric acid, chromic anhydride, The impurities can be decomposed and applied during cleaning. Simply by applying a surfactant to the surface of the diamond particles or immersing the diamond particles in a surfactant solution, a durable hydrophilic group cannot be obtained. By carrying out an extreme treatment such as removing impurities from synthetic diamond, diamond particles having a durable hydrophilic property (hydrophilic group) suitable for the present invention can be obtained.

  In the present invention, by imparting hydrophilicity to the diamond surface, the agglomeration of diamond particles that inevitably occurs when melt-melt kneading to spin the resin is reduced. Furthermore, it can be excellent in adhesiveness with the hydrophilic resin constituting the fiber.

  Furthermore, the diamond particles may be either single crystal or polycrystal, but polycrystal is preferable because there are many sharp parts that contribute to polishing in terms of structure.

  The proportion of diamond particles may be set as appropriate according to the purpose of polishing, but the precision polishing closer to the finish becomes lower in concentration. When used for precision polishing, it is 0.01 to 30% by weight, preferably 0.05 to 15% by weight, more preferably about 0.1 to 10% by weight, based on the hydrophilic resin containing diamond. .

(Hydrophilic resin)
The hydrophilic resin used in the present invention is not particularly limited as long as it is hydrophilic, for example, highly compatible with diamond particles having a hydrophilic group on the particle surface. For example, cellulose resins, polyalkylene glycol resins, vinyl resins are used. In addition to resins, polyamide-based resins, polyester-based resins, and the like, polymers having a hydrophilic group introduced may also be mentioned. When fibers are used, the equilibrium moisture content is 2.5% by weight or more (for example, 2.5 to 30% by weight). Resin) is preferred. Such resins include vinyl resins and / or polyamide resins. Here, the equilibrium moisture content means the moisture content of a polymer that has been allowed to stand in air at a constant temperature and humidity (for example, 23 ° C., 65% RH) and has reached an equilibrium state. (Mass) x 100 (%).

Examples of vinyl resins include vinyl acetate resins (eg, polyvinyl acetate, ethylene-vinyl acetate copolymers), polyvinyl pyrrolidone, polyvinyl ether resins (eg, polyvinyl methyl ether, polyvinyl ethyl ether, etc.), vinyl, and the like. Examples thereof include alcohol resins (for example, polyvinyl alcohol, ethylene-vinyl alcohol copolymer), vinyl acetal resins (for example, polyvinyl formal, polyvinyl butyral, and the like). These vinyl resins can be used alone or in combination of two or more. Among these vinyl resins, vinyl acetate resins, vinyl alcohol resins, vinyl acetal resins, particularly vinyl alcohol resins (for example, polyvinyl alcohol polymers such as polyvinyl alcohol, α-C ₂₋ such as ethylene, etc.) _A copolymer of _4- olefin and vinyl alcohol is preferred. In addition, you may acetalize vinyl alcohol-type resin (especially polyvinyl alcohol-type polymer which has a vinyl alcohol unit as a main unit) by aldehydes, such as formaldehyde and butyraldehyde. The degree of acetalization is about 10 to 45 mol%, preferably about 20 to 40 mol% in all hydroxyl groups. In the copolymer of α-C _2-4 olefin (particularly ethylene) and vinyl alcohol, the proportion of α-C _2-4 olefin (particularly ethylene) is selected from the range of about 5 to 70 mol% in the copolymer. It may be, for example, about 5 to 20 mol%, but from the viewpoint of hydrophilicity, melt spinnability and prevention of falling off of abrasive grains, for example, 20 to 65 mol%, preferably 25 to 60 mol%, More preferably, it may be about 30 to 55 mol%.

Examples of polyamide resins include aliphatic polyamide resins (for example, polyamide 46, poly 6, polyamide 66, polyamide 610, polyamide 10, polyamide 11, polyamide 12, polyamide 612, etc.), semi-aromatic polyamide resins (for example, polyamide). 6IT, polyamide 66IT, polyamide 9T, etc.), wholly aromatic polyamide resins (for example, polyparaphenylene terephthalamide, polymetaphenylene terephthalamide, MXD-6, etc.). The abbreviation “I” is isophthalic acid, and “T” is terephthalic acid. These polyamide resins can be used alone or in combination of two or more. Among these polyamide-based resins, aliphatic polyamides (polyamides mainly composed of C _4-12 alkane units such as polyamide 6 and polyamide 66) and semi-aromatic polyamides (C _8-12 such as 1,9-nonanediamine) are used. Polyamides containing alkanediamine and aromatic dicarboxylic acid such as terephthalic acid as main polymerization components are preferred.

  In particular, an ethylene-vinyl alcohol copolymer from the viewpoint of excellent affinity (familiarity) with water generally used for cooling at the time of polishing, fiber strength at the time of polishing, processability to fibers and fiber structures, Polyamide 6 is preferred, and polyamide 66 and polyamide 9T are preferred in applications where heat resistance is also required. Furthermore, as will be described later, when the polishing fiber is a core-sheath type composite fiber having a core part composed of a thermotropic liquid crystal polymer, as a hydrophilic resin constituting the sheath part from the viewpoint of easy spinning. Polyamide 66 may be used.

(Polishing fiber)
The polishing fiber of the present invention only needs to contain the hydrophilic resin containing the diamond particles, but the fiber surface is preferably coated with the hydrophilic resin from the standpoint of polishing properties. In particular, the hydrophilic resin is, for example, 50% or more (for example, 50 to 100%) of the fiber surface, preferably 70% or more (for example, 70 to 100%), and more preferably 90% or more (for example, 90 to 90%). 100%).

  Further, it is preferable that at least a part of the diamond particles (particles located on the fiber surface side) is partially embedded in the hydrophilic resin. The diamond particles partially protrude from the hydrophilic resin on the fiber surface, thereby improving the polishing properties. It is preferable that the diamond particles protrude on the fiber surface to such an extent that particles having the same size as the particle diameter can be confirmed.

  The fiber having such a surface structure may be a fiber composed solely of a hydrophilic resin containing diamond particles, or a composite fiber combined with a hydrophilic resin or non-hydrophilic resin containing no diamond particles. May be. Composite fibers include fibers that are compounded in a cross section perpendicular to the length direction thereof, for example, core-sheath type composite fibers having a hydrophilic resin containing diamond particles as a sheath, sea-island type composite fibers, and bonded type composites. Fiber etc. are included. Among these fibers, a composite fiber is preferable because fiber characteristics such as strength and productivity can be controlled. Among these, a core-sheath type composite fiber is particularly preferable because it can easily control the fineness, the coverage, the content of diamond particles, and the like. The core-sheath type composite fiber is a composite fiber obtained by a method of coating a solution in which the hydrophilic resin is dissolved in a hydrophilic solvent such as water, or a method of coating by hot melting like a cover yarn. However, from the viewpoint of simplicity and the like, fibers obtained by composite spinning are preferable.

  The polishing fiber production method of the present invention may be any of melt spinning, dry spinning, dry and wet spinning, and wet spinning, but a composite fiber using a plurality of types of resins (particularly, a core-sheath type composite fiber) is used. In some cases, melt spinning is suitable because it can be easily combined.

  The method for producing such a core-sheath type composite fiber is not particularly limited as long as it is a method capable of obtaining a composite fiber satisfying the requirements specified in the present invention. As a suitable method, a composite spinning apparatus is used and a core is used. It can be produced by introducing the composite flow of both polymers toward the center of the nozzle inlet and discharging from the nozzle while covering the entire polymer flow constituting the component with the polymer constituting the sheath component. The spinneret temperature is, for example, Mp ° C. to (Mp + 80) ° C., preferably (Mp + 10) ° C. to (Mp + 70) ° C., where Mp is the melting point of a polymer having a high melting point among the polymers constituting the composite fiber. More preferably, it is about (Mp + 20) ° C. to (Mp + 60) ° C.

  The yarn discharged from the spinning nozzle may be wound as it is without being stretched, or may be stretched as necessary. The stretching may be performed at a temperature of not less than 0.5 to 10 times (for example, 1 to 7 times, preferably 1.5 to 5 times) at a temperature equal to or higher than the glass transition point (Tg) of the composite fiber. Furthermore, the stretched fiber may be heat-treated (heat set) in the range of the glass transition point (Tm) to (Tm-10) ° C. of the resin constituting the core component.

  In the core-sheath type composite cross-section fiber, the core component constituting the core part is preferably a resin excellent in adhesiveness with the sheath component constituting the sheath part and excellent in strength. As a core component, it can select suitably from intensity | strength, chemical-resistance, adhesiveness with a sheath component, etc., for example, polyolefin resin, polyester resin, polyamide resin, polyphenylene sulfide resin, polycarbonate resin, acrylic Resin, polyurethane resin, rubber component and the like. These core components can be used alone or in combination of two or more. Among these core components, from the viewpoint of strength, polyolefin resins (for example, polypropylene resins such as polypropylene and propylene-ethylene copolymer), polyester resins (for example, polyethylene terephthalate (PET), polybutylene terephthalate, etc.) And polyalkylene arylate resins, polyarylate, molten liquid crystalline aromatic polyester, etc.) and polyamide resins (eg, aliphatic polyamides such as polyamide 6 and polyamide 66) are preferred.

  Furthermore, in the present invention, a thermotropic liquid crystal polymer (melted liquid crystalline polymer) is particularly preferable because of excellent melt spinnability, high strength and high elastic modulus in an undrawn yarn state. Usually, the fiber obtained by spinning is stretched to increase the strength, but when spinning and stretching a resin containing diamond particles, the resin is stretched but the diamond particles are not stretched. Therefore, peeling occurs between the diamond particles and the resin existing therearound, a space is formed between the diamond particles and the resin, and the diamond particles easily fall off the fiber surface. In this invention, since the diamond particle to be used has a hydrophilic group, there exists a merit that the adhesive force of a diamond particle and resin is high and it is hard to peel. However, it is still difficult to completely prevent peeling. On the other hand, as described above, the molten liquid crystalline aromatic polyester does not need to be stretched like normal fibers, and has high strength even when unstretched. Therefore, by using a thermotropic liquid crystal polymer as the core component, the resin of the sheath component and the diamond particles can be prevented from peeling due to stretching, and when used as polishing fibers, the diamond particles are more highly prevented from falling off. it can.

  Furthermore, since the thermotropic liquid crystal polymer has a remarkably high elastic modulus compared to other resins, the fiber using the thermotropic liquid crystal polymer has a property that it is difficult to bend. Therefore, even if polishing, only the polished surface can be accurately polished without changing the target surface structure of the object. For example, accurate or precise polishing with a rounded corner can be performed without rounding the target corner.

  In the present invention, the melt liquid crystallinity (anisotropic) means a characteristic showing optical liquid crystallinity (anisotropic) in the melt phase. Melt liquid crystallinity can be recognized by, for example, placing a sample on a hot stage, heating and heating in a nitrogen atmosphere, and observing the transmitted light of the sample.

The thermotropic liquid crystal polymer includes a liquid crystal polyester resin, a liquid crystal polyamide resin, a liquid crystal polyester amide resin, and the like. Among these thermotropic liquid crystal polymers, molten liquid crystalline aromatic polyester resins are widely used. The molten liquid crystalline aromatic polyester resin is an aromatic polyester resin having a mesogen group (group having liquid crystal forming ability) such as a p-substituted aromatic ring, a linear biphenyl group, and a naphthyl group as a structural unit. Also good. Specifically, aromatic hydroxycarboxylic acid (for example, p-hydroxybenzoic acid, 2-oxy-6-naphthoic acid, etc.), aromatic dicarboxylic acid (for example, terephthalic acid, isophthalic acid, etc.), diol component (for example, Examples thereof include copolymers obtained by using at least one monomer selected from hydroquinone, aromatic diols such as 4,4′-dihydroxybiphenyl, C _2-6 alkanediols such as ethylene glycol, and the like. . These monomers may have a substituent (for example, an alkyl group such as a methyl group, an aryl group such as a phenyl group, or a halogen atom such as a chlorine atom or a bromine atom).

  Specific molten liquid crystalline aromatic polyester resins include the following polymers (1) to (10).

  Polymer (1): Polyester composed of a combination of units represented by the following formula (1)

ポリマー（２）：下記式（２）で表される単位の組み合わせで構成されたポリエステル

Polymer (2): Polyester composed of a combination of units represented by the following formula (2)

ポリマー（３）：下記式（３）で表される単位の組み合わせで構成されたポリエステル

Polymer (3): polyester composed of a combination of units represented by the following formula (3)

ポリマー（４）：下記式（４）で表される単位の組み合わせで構成されたポリエステル

Polymer (4): polyester composed of a combination of units represented by the following formula (4)

［式中、Ｘ^１、Ｘ^２、Ｙ^１及びＹ^２は、同一又は異なって、水素原子、ハロゲン原子（塩素原子、臭素原子など）又はアルキル基（メチルなどのＣ_１−４アルキル基など）を示し、Ｚは、

[Wherein, X ¹ , X ² , Y ¹ and Y ² are the same or different and represent a hydrogen atom, a halogen atom (a chlorine atom, a bromine atom, etc.) or an alkyl group (a C _1-4 alkyl group such as methyl, etc.) Z is

又は

Or

を示す］。

Is shown].

  Polymer (5): Polyester composed of a combination of units represented by the following formula (5)

ポリマー（６）：下記式（６）で表される単位の組み合わせで構成されたポリエステル

Polymer (6): Polyester composed of a combination of units represented by the following formula (6)

ポリマー（７）：下記式（７）で表される単位の組み合わせで構成されたポリエステル

Polymer (7): Polyester composed of a combination of units represented by the following formula (7)

ポリマー（８）：下記式（８）で表される単位の組み合わせで構成されたポリエステル

Polymer (8): Polyester composed of a combination of units represented by the following formula (8)

ポリマー（９）：下記式（９）で表される単位の組み合わせで構成されたポリエステル

Polymer (9): Polyester composed of a combination of units represented by the following formula (9)

ポリマー（１０）：下記式（１０）で表される単位の組み合わせで構成されたポリエステル

Polymer (10): Polyester composed of a combination of units represented by the following formula (10)

ポリマー（１１）：下記式（１１）で表される単位の組み合わせで構成されたポリエステル

Polymer (11): Polyester composed of a combination of units represented by the following formula (11)

これらの溶融液晶性芳香族ポリエステル系樹脂のうち、ｐ−ヒドロキシ安息香酸と、２−オキシ−６−ナフトエ酸、テレフタル酸及びイソフタル酸からなる群から選択された少なくとも一種とから得られる共重合体（例えば、ポリマー（５）、ポリマー（１１））などが好ましい。中でも、単環式芳香族オキシカルボン酸（特にｐ−ヒドロキシ安息香酸）と、多環式芳香族オキシカルボン酸（特に２−オキシ−６−ナフトエ酸）とから得られるポリマー（特にポリマー（５））が特に好ましい。このポリマーにおいて、単環式芳香族オキシカルボン酸単位と、多環式芳香族オキシカルボン酸単位との割合（重量比）は、前者／後者＝３０／７０〜９９／１、好ましくは４０／６０〜９７／３、さらに好ましくは５０／５０〜９６／４（特に６５／３５〜９０／１０）程度である。

Of these molten liquid crystalline aromatic polyester resins, a copolymer obtained from p-hydroxybenzoic acid and at least one selected from the group consisting of 2-oxy-6-naphthoic acid, terephthalic acid and isophthalic acid (For example, polymer (5), polymer (11)) and the like are preferable. Among them, a polymer (particularly polymer (5)) obtained from a monocyclic aromatic oxycarboxylic acid (particularly p-hydroxybenzoic acid) and a polycyclic aromatic oxycarboxylic acid (particularly 2-oxy-6-naphthoic acid). Is particularly preferred. In this polymer, the ratio (weight ratio) of the monocyclic aromatic oxycarboxylic acid unit to the polycyclic aromatic oxycarboxylic acid unit is the former / the latter = 30/70 to 99/1, preferably 40/60. It is about -97/3, More preferably, it is about 50 / 50-96 / 4 (especially 65 / 35-90 / 10).

  In the core-sheath type composite fiber, the ratio (weight ratio) between the core component and the sheath component is, for example, core component / sheath component = 1 / 0.1 to 1/3, preferably 1 / 0.2. Is about 1/2, more preferably about 1 / 0.25 to 1 / 1.5.

  As described above, the polishing fiber of the present invention can be produced by a conventional method such as melt spinning. In the fiber production process, in order to suppress wear and damage of the processing machine, a layer not containing the diamond particles is provided. You may form as an outermost layer of a fiber. By making the fiber temporarily have such a structure, diamond particles are not exposed on the fiber surface, so that the surface of the guide, roller, heating plate, etc. can be prevented from being damaged in the fiber manufacturing process. It is excellent in terms of manufacturing processability.

  Such an outermost layer is a layer used from the viewpoint of productivity, and is removed after fiber formation. As a removal method, the target fiber (the polishing fiber of the present invention in the lower layer of the outermost layer, for example, a layer composed of the hydrophilic resin containing the diamond particles) is not dissolved, and the outermost layer is formed. A method of dissolving and removing the outermost layer by treating with a dissolving solvent is used. Such a solvent can be selected according to the type of fiber in the lower layer of the outermost layer, and examples thereof include water, an alkali or acidic aqueous solution, an aqueous solution containing a surfactant, and an organic solvent. Furthermore, as a removal method, a method of immersing in a high-temperature solvent is preferable. The temperature of the solvent may be, for example, about 60 to 100 ° C. (particularly 70 to 100 ° C.).

The component constituting the outermost layer may be any component that is different in solubility from the fibers in the lower layer of the outermost layer and that can be easily dissolved and removed with the solvent. Examples of such components include cellulose fibers (such as hydroxy C _1-3 alkyl cellulose fibers such as hydroxymethyl cellulose), vinyl fibers (such as polyvinyl pyrrolidone, polyvinyl ether, polyvinyl alcohol fibers, and polyvinyl acetal fibers), acrylics, and the like. Copolymers or alkali metal salts thereof (such as copolymers containing units composed of acrylic monomers such as (meth) acrylic acid and hydroxyl group-containing (meth) acrylic acid esters), water-soluble polyamide fibers (Polyamide fibers having polyoxyethylene units, polyamide fibers introduced with sulfonic acid groups, hydroxyl groups, etc.), water-soluble polyester fibers (polyester fibers having polyoxyethylene units, sulfonic acid groups, amino groups, etc.) Introduced po Reester fiber, etc.). Among them, hot water-soluble copolymer polyester resins and alkali-soluble copolymer polyester resins (for example, water-soluble aromatic polyester resins having a sulfonic acid group and a polyoxyethylene group) can be melt-spun. Easy-to-removable resins such as polyvinyl alcohol resins (for example, ethylene-vinyl alcohol copolymer), in particular, ethylene from the point that melt spinning is easy and the outermost layer is difficult to peel off until dissolution and removal. An ethylene-vinyl alcohol copolymer copolymerized at a ratio of 20 mol% (particularly 3 to 15 mol%) is preferred. In the case of forming such an outermost layer, the ratio of the outermost layer is, for example, 1 to 150 parts by weight, preferably 5 to 100 parts by weight with respect to 100 parts by weight of the polishing fibers (fibers excluding the outermost layer). Part, more preferably about 10 to 80 parts by weight (particularly 30 to 60 parts by weight). Further, the ratio of the outermost layer may be about 60 to 10%, particularly about 40 to 20% of the total weight of the fiber including the outermost layer.

  Specifically, when a core-sheath type composite fiber is obtained as the polishing fiber of the present invention, a layer composed of a hydrophilic resin containing diamond particles is present further inside than the outermost layer in the melt spinning step. After composite spinning of the core-sheath type composite fiber of the layer, the sheath component of the outermost layer is removed by treatment with a solvent, and a fiber in which a layer composed of a hydrophilic resin containing diamond particles appears on the surface can be obtained. .

  The polishing fiber of the present invention is a conventional additive that imparts other functionality according to the application, for example, a colorant, a flame retardant, a stabilizer (thermal stabilizer, ultraviolet absorber, light stabilizer, antioxidant). Etc.), an antistatic agent, a hydrophilizing agent, a plasticizer, a lubricant, a crystallization rate retarder, and the like. These additives can be used alone or in combination of two or more.

  The shape of the polishing fiber of the present invention (the shape of the entire fiber) may be a circular cross section in a direction perpendicular to the length direction of the fiber, but may be an irregular cross section (for example, an elliptical cross section, a tri-octagon, etc. Polygonal cross section, T-shaped cross section, Y-shaped cross section, C-shaped cross section, etc.).

  The fineness of the polishing fiber of the present invention can be appropriately set in the range of about 0.01 to 100 decitex (dtex) according to the use of the abrasive, but finer fineness fibers are suitable for precision processing. ing. The ultrafine fiber can be directly made fine at the time of spinning, but can also be obtained by splitting from a split type composite fiber or sea-island type composite fiber, or by removing sea components. In particular, in the case of a sea-island type composite fiber, an ultrafine polishing fiber excellent in strength and processability can be obtained by using a core-sheath composite fiber as the island component. The fineness of the ultrafine polishing fiber thus obtained is, for example, 5 dtex or less (for example, 0.01 to 5 dtex), preferably 1 dtex or less (for example, 0.03 to 1 dtex), and more preferably 0.5 dtex or less ( For example, 0.05 to 0.5 dtex).

  The polishing fiber of the present invention may be appropriately set according to the single fiber fineness, and may be a long fiber or a short fiber. The average fiber length is, for example, about 0.1 to 20 mm, preferably about 0.5 to 10 mm, preferably about 1 to 5 mm. In particular, as described later, when used as a flock (flockey) process or when used as a wet nonwoven fabric, a shortcut product having a length of several mm may be used.

  The strength of the polishing fiber of the present invention is not particularly limited, but in order to suppress yarn breakage and fluff when processed into a fiber structure and prevent damage to the fiber when used as an abrasive, for example, 2 cN / Dtex or more (for example, 2 to 30 cN / dtex), preferably 2.5 cN / dtex or more (for example, 2.5 to 20 cN / dtex), more preferably 3 cN / dtex or more (for example, 3 to 15 cN / dtex), In particular, it is 5 cN / dtex or more (for example, 5 to 10 cN / dtex). In order to achieve such strength, the fiber may be highly stretched or a molten liquid crystalline aromatic polyester may be used.

  The polishing fiber of the present invention has high elongation, for example, 5 to 100%, preferably 10 to 70%, more preferably about 15 to 50%.

(Abrasive)
The abrasive of the present invention only needs to contain the polishing fiber. That is, the abrasive of the present invention is a fiber structure containing the above-mentioned abrasive fibers. Specific shapes include monofilaments, multifilaments, cords, woven fabrics (plain weave, oblique weave, satin weave, etc.), knitted fabrics. (Machine knitting, crochet knitting, bar needle knitting, Afghan knitting, lace knitting, etc.), dry nonwoven fabric (needle punch nonwoven fabric, hydroentangled nonwoven fabric, spunbond nonwoven fabric, melt blown nonwoven fabric, electrospun nonwoven fabric, etc.), wet nonwoven fabric, and the like.

  The nonwoven fabric composed of the abrasive fiber of the present invention is produced, for example, by using a sea-island composite fiber having a hydrophilic resin containing diamond particles as abrasive grains as an island component and a soluble resin as a sea component. It may be a napped fiber fabric in which ultrafine fibers containing abrasive grains are present on the nonwoven fabric surface by raising the surface of the nonwoven fabric after impregnating and solidifying the binder resin and dissolving and removing sea components.

  Furthermore, the abrasive of the present invention may be an abrasive in which abrasive fibers are applied to the base fabric. For example, after the abrasive fiber of the present invention is cut to a length of several millimeters, a polishing material in which the cut abrasive fiber is planted on the surface of the base fabric by a flocking process, and the abrasive fiber of the present invention is low Examples thereof include an abrasive in which a fabric serving as a base fabric is laminated and integrated with a fabric of basis weight, and an abrasive in which the polishing fibers of the present invention are aligned on the surface of the fabric serving as a base fabric.

  Examples of the base fabric include natural fibers such as cotton, hemp, wool, and silk, polyolefin fibers, vinyl acetate fibers, acrylonitrile fibers, polyamide fibers, polyester fibers, and polyacetal fibers, and acetate fibers. And semi-synthetic fibers such as rayon, cupra and tencel. These fibers can be used alone or in combination of two or more. When a fabric is used as the base fabric of the abrasive, it is not necessary to have abrasive grains in the base fabric. If the strength is high, the purpose of the base fabric can be achieved.

  Examples of binder resins used in napped fiber fabrics and flocking processes include polyolefin resins, acrylic resins, styrene resins, vinyl acetate polymers, polyvinyl alcohol polymers, ethylene-vinyl alcohol copolymers, An adhesive resin such as a polyamide-based resin can be used. These binder resins can be used alone or in combination of two or more.

  In the present invention, an abrasive can be appropriately selected from these shapes according to the purpose of polishing.

  In the abrasive of the present invention, other fibers (for example, fibers exemplified in the above-mentioned base fabric) can be mixed and used as necessary within the range not impeding the effects of the present invention. Other fibers may be either short fibers or long fibers.

  In the abrasive of the present invention, the diamond abrasive grains are firmly fixed and held on the constituent resin by the interaction between the hydrophilic group of the diamond particles and the hydrophilic resin, and part of the diamond abrasive grains are exposed on the fiber surface. Therefore, there is almost no loss of abrasive grains during polishing. However, when water-soluble vinyl alcohol resin (especially vinyl alcohol resin with low ethylene content) is used as the hydrophilic resin and subjected to wet polishing, the abrasive grains are close to the fiber surface in order. Although it falls off the fiber and is released, the abrasive grains are uniformly grown one after another from the inside of the fiber, so that it is difficult to cause uneven polishing.

  Since the polishing fiber of the present invention has a high elongation and the fiber structure also has elasticity, it is less likely to exert excessive pressure on the object to be polished. This works effectively as an appropriate buffering action even when used under high-speed polishing conditions, and can be polished without degrading the accuracy of the finished surface. In addition, since it has elasticity, it can be used for lapping because it can polish a curved surface or some uneven surface. Further, if the fibrous structure is impregnated with a hard resin, the elasticity becomes low and a hard abrasive becomes possible, and polishing with less edge sagging becomes possible.

  The shape of the abrasive of the present invention is not particularly limited, and examples thereof include a shape of a roll, a sheet, and a disk. For example, a roll-shaped abrasive can be used as an abrasive tape for texturing an aluminum substrate or a glass substrate hard disk. Further, examples of the polishing method include wheel polishing, belt polishing, and vibration polishing. Any method can be used by appropriately selecting the shape of the abrasive.

  The polishing fiber of the present invention hardly loses abrasive grains (diamond particles) due to the polishing treatment and has high polishing ability. Therefore, the abrasive using this abrasive fiber can be used for surface polishing and cleaning of metals, synthetic resins, wood, stones and the like. In particular, it is possible to suppress wear and damage of processing machines in the fiberizing process, improve productivity, and enable precise polishing, so electronic or optical parts in the field of electronics or optical fields that require high surface roughness. It is effective for precision polishing (for example, silicon wafer, hard disk, magnetic head, optical fiber, ferrule, liquid crystal panel, etc.).

  EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention concretely, this invention is not limited by this. In addition, physical property evaluation and performance evaluation in Examples and Comparative Examples were performed by the following methods.

(1) Passability of fiberizing process The fiber is spun, and if necessary, is subjected to a treatment such as stretching and wound on a bobbin, the surface of the guide, roller, heating plate, etc. is made of fiber-containing diamond. It was investigated whether or not it was cut. When it was clearly recognized by the naked eye that it was cut by 10 hours of implementation, it was determined as “Yes”, and when it was not recognized, it was determined as “No”.

(2) Fiber properties (strength and elongation)
It measured according to JIS L1013.

(3) Weight per unit area Measured according to JIS L1096.

(4) Particle size of diamond contained in the fiber The surface of the fiber is magnified 10,000 times with a scanning electron microscope (SEM), and a photograph is taken. The size of the projections in the vertical and horizontal directions was measured, and the arithmetic average was defined as the particle diameter (μm).

(5) Polishability evaluation A silicon wafer was wet-polished, and the surface roughness Ra of the polished silicon wafer surface was measured with an atomic force microscope (AFM) (nm).

  In addition, the state of diamond particles contained in the polishing fiber after the abrasiveness evaluation test was observed with a scanning electron microscope, the diamond particles were observed to drop off, and the self-generated state was observed. evaluated.

A: Almost no omission is observed. O: Some omission is observed. X: Obviously many omissions are observed.

Example 1
As the abrasive grains, polycrystalline diamond particles having an average particle diameter of 0.25 μm and having hydroxyl groups on the particle surface (manufactured by Sumitomo Coal Mining Co., Ltd., Lot. No. 0503H1025: the particle surface is made hydrophilic by impurity removal work) are used. , Ethylene-vinyl alcohol copolymer resin (EVOH; manufactured by Kuraray Co., Ltd., EVAL, E112BY) is used as the sheath component resin, and polyamide 6 (UBE Nylon, UBE nylon, 1013BK1) is used as the core component resin. A core-sheath type composite cross-section fiber was produced by composite spinning of a sheath component resin containing 10% by weight of abrasive grains and a core component resin in a weight ratio of 3: 7. Regarding mixing of the sheath component resin and the diamond particles, before the spinning, the sheath component resin was dry blended with the diamond particles, and then the sheath component resin containing the diamond particles and the core component resin were melt-spun at 280 ° C. . The fiber obtained by spinning was stretched 2.5 times at 50 ° C. and then heat-set at 140 ° C. to obtain a core-sheath composite cross-section fiber of 72 dtex / 24 filament. The fiber strength was 5.51 cN / dtex, and it had sufficient strength.

This fiber was cut to a length of 1.5 mm, and then a base cloth obtained by applying an acrylic emulsion resin (FK6600, manufactured by Chuo Rika Kogyo Co., Ltd.) to a cotton cloth with a basis weight of 80 g / m ² was flocked to obtain an abrasive. Using the obtained flocky, a silicon wafer was polished, and the surface roughness after polishing was measured by AFM. Further, when the Flocky fibers after polishing were observed with an SEM, almost no diamond particles dropped off. The evaluation results are shown in Table 1. In addition, as a result of taking an electron micrograph of the polishing fiber used in this example and measuring the size of the protrusion, it was confirmed that the value was almost the same as the average particle diameter used as a raw material. It was confirmed that there was almost no agglomeration of abrasive grains in the fiber production process.

Example 2
A core-sheath composite fiber (51 dtex) was prepared in exactly the same manner as in Example 1 except that the polyamide 6 used as the core component resin in Example 1 was used instead of EVOH used in Example 1 and stretched 3.5 times. / 24 filament) and flocky. This abrasive was used for the same polishing treatment as in Example 1. The evaluation results of fiber properties and polishing performance are shown in Table 1. Also in this polishing fiber, the size of the protrusion was almost the same as the fiber of Example 1.

Example 3
Instead of EVOH used in Example 1, polyvinyl alcohol resin [manufactured by Kuraray Co., Ltd., EXCEVAL (ethylene copolymerization amount: 10 mol%, average polymerization degree: 330, saponification degree: 98.4 mol%, melting point: 206 ° C.) and CP4104B2] were used in the same manner as in Example 1 to obtain core-sheath composite fiber core-sheath composite fiber (78 dtex / 24 filament) and flocky. This abrasive was used for the same polishing treatment as in Example 1. The evaluation results of fiber properties and polishing performance are shown in Table 1. SEM observation of the fiber after polishing evaluation showed that the sheath component of the water-soluble resin was partially worn, but the core component was not completely exposed, and new diamond particles were spontaneously generated from the worn fiber surface. The ratio of diamond particles exposed on the surface was the same. Also in this polishing fiber, the size of the protrusion was almost the same as the fiber of Example 1.

Example 4
Using the sheath component of Example 1 as the island component, and using the polyvinyl alcohol resin used in Example 3 as the sea component, the sea-island ratio is sea component / island component = 30: 70 (weight ratio). Fusion composite spinning was performed at 250 ° C., stretched 2.3 times at 70 ° C., heat-set at 140 ° C., and a sea-island composite fiber having 72 dtex / 24 filaments and 36 island components in cross section was obtained. . The fibers were bundled, crimped and cut to obtain a raw cotton having a number of crimps of 15/25 mm and a cut length of 51 mm. This raw cotton is carded and needled, and this nonwoven fabric is fixed with an aqueous urethane resin (Daiichi Kogyo Seiyaku Co., Ltd., Superflex E4000), and then the sea components in the composite fiber are extracted and removed with hot water at 80 ° C. Thus, a nonwoven fabric composed of 0.06 dtex ultrafine polishing fibers containing diamond particles was obtained. The evaluation results of the polishing performance of this nonwoven fabric are shown in Table 1. Also in this polishing fiber, the size of the protrusion was almost the same as the fiber of Example 1.

Example 5
The discharge amount is adjusted so that the fineness after stretching of the sea-island fibers of Example 4 is 360 dtex / 24 filaments, and converging, crushing (cut length of 0.15-0.25 mm), and hot water extraction of sea components are performed. (80 ° C.) to obtain a polishing fiber powder having a fineness of 0.3 dtex. Using this fiber powder, a flock was obtained in the same manner as in Example 1. Table 1 shows the evaluation results of the polishing performance. Also in this polishing fiber, the size of the protrusion was almost the same as the fiber of Example 1.

Example 6
A fiber and an abrasive were prepared and evaluated in exactly the same manner as in Example 1 except that the diamond particles in Example 1 were replaced with diamond particles having an average particle diameter of 0.1 μm. The evaluation results are shown in Table 1. In this example, when the size of the abrasive grains present in the polishing fiber was observed from the size of the protrusions by an electron micrograph, a value almost the same as the particle size of the diamond particles used was obtained, and the fiber It was confirmed that almost no aggregation of particles occurred during the production.

Example 7
EVOH containing diamond particles used in Example 1 is a sheath component, polyamide 6 is a core component, and the outermost layer of these core-sheath components is a sheath component. Modified polyethylene terephthalate (5 mol% sulfoisophthalic acid, polyethylene glycol 8) Using an intrinsic viscosity measured at 30 ° C. in an equal weight mixed solvent of phenol / tetrachloroethane: 0.51), a sheath component resin in the outermost layer and a sheath component resin containing 3% by weight of abrasive grains The core component resin is subjected to three-component composite spinning at 280 ° C. so that the weight ratio of the outermost sheath component: sheath component: core component = 3: 3: 4, and the resulting fiber is obtained at 2.degree. After 5-fold stretching, heat setting was performed at 120 ° C. to obtain a three-component core-sheath type composite cross-section fiber of 53 dtex / 16 filament. This was immersed in a 40 g / liter sodium hydroxide solution at 90 ° C. for 15 minutes to decompose and remove the modified polyethylene terephthalate component to obtain a core-sheath fiber having diamond particles on the fiber surface. The fiber strength was 5.13 cN / dtex, and the fiber strength was sufficient.

Example 8
A plain weave is prepared using the three-component core-sheath composite cross-section fiber obtained in Example 7, and the modified polyethylene terephthalate is decomposed and removed in the same manner as in Example 7 to obtain a woven fabric having diamond particles on the fiber surface. It was. The evaluation results of the polishing performance of this fabric are shown in Table 1. Also in this polishing fiber, the size of the protrusion was almost the same as the fiber of Example 1.

Example 9
Except that the island component was the core-sheath component of Example 1, a nonwoven fabric composed of 0.06 dtex ultrafine core-sheath fibers containing diamond particles was obtained in exactly the same manner as in Example 4. The evaluation results of the polishing performance of this nonwoven fabric are shown in Table 1. Also in this polishing fiber, the size of the protrusions was almost the same as that of Example 1.

Example 10
Polyamide 66 containing 5% by weight of diamond particles used in Example 1 (UBE Nylon 66, manufactured by Ube Industries, Ltd.) is a sheath component, a molten liquid crystalline aromatic polyester (73 mol% of p-hydroxybenzoic acid units and 2 Example 7 using the same modified polyethylene terephthalate as in Example 7 as a core component in the outermost layer of these core-sheath components, a copolymer comprising 27 mol% of hydroxy-naphthalene-6-carboxylic acid units) In the same manner as above, spinning was performed at 320 ° C., and the sheath component of the outermost layer: sheath component: core component = 3: 3: 4 in a weight ratio and 112 dtex / 16 filament 3-component core-sheath composite fiber was wound on a bobbin I took it. This was treated with an alkaline solution in the same manner as in Example 7 to remove the outermost layer, and a core-sheath composite fiber having diamond particles on the surface was obtained. The fiber strength was 6.55 cN / dtex and the initial elastic modulus was 400 cN / dtex, which had sufficient strength and elastic modulus. Further, when this filament was used to polish the inner surface of an alumina tube having an inner diameter of 0.1 mm, the inner surface was glossy and could be mirror-finished. Furthermore, when this fiber was pressed against an alumina plate having a thickness of 1 mm at a speed of 800 m / min, the alumina plate could be cut with a width of 0.1 mm.

Example 11
A plain weave is prepared using the three-component core-sheath type composite cross-section fiber obtained in Example 10, and the modified polyethylene terephthalate is decomposed and removed in the same manner as in Example 10 to obtain a woven fabric having diamond particles on the fiber surface. It was. The evaluation results of the polishing performance of this fabric are shown in Table 1. Also in this polishing fiber, the size of the protrusion was almost the same as the fiber of Example 1.

Example 12
In Example 3, polyamide 6 containing 3% by weight of diamond particles used in Example 1 was used as a sheath component, polyamide 6 containing no diamond particles was used as a core component, and the outermost layer of these core-sheath components was further used as a sheath component. Using the polyvinyl alcohol used, in the same manner as in Example 7, three-component composite spinning was carried out at 260 ° C. so that the weight ratio of sheath component: sheath component: core component = 3: 3: 4 of the outermost layer was obtained. The resulting fiber was stretched 2.5 times at 100 ° C. and then heat-set at 120 ° C. to obtain a three-component core-sheath type composite cross-section fiber of 53 dtex / 16 filament. This was immersed in 90 ° C. hot water for 30 minutes to dissolve and remove the polyvinyl alcohol, thereby obtaining a nylon-sheath composite fiber having diamond particles on the fiber surface. The fiber strength was 5.01 cN / dtex, and the fiber had sufficient strength.

Comparative Example 1
A fiber and an abrasive were prepared and evaluated in exactly the same manner as in Example 1 except that the diamond particles in Example 1 were replaced with diamond particles having an average particle diameter of 3 μm. The evaluation results are shown in Table 1. Although a small amount of the sample for evaluation could be collected, the processability was not good, such as fluffing in the spinning process and the drawing process. Also, the surface roughness was low in polishing performance. In this comparative example, when the size of the abrasive grains present in the polishing fiber was observed from the size of the projections by an electron micrograph, a value almost the same as the particle size of the diamond particles used was obtained.

Comparative Example 2
In place of EVOH used in Example 1, a hydrophobic resin [polypropylene (manufactured by Prime Polymer Co., Ltd., Y2005GP)] was used, and the same diamond particles used in Example 1 were dry blended to this hydrophobic resin. Except for the above, fibers and abrasives were prepared and evaluated in the same manner as in Example 1. The evaluation results are shown in Table 1. Although a small amount of the sample for evaluation could be collected, the processability was not good, such as fluffing in the spinning process and the drawing process. Also, the surface roughness was low in polishing performance. Furthermore, when the fiber after polishing evaluation was observed with an SEM, a location where diamond particles were removed from the sheath component was observed, and the ratio of diamond particles on the fiber surface was reduced. In this comparative example, when the size of the abrasive grains present in the polishing fiber was observed from the size of the projections by an electron micrograph, it was confirmed that the size was much larger than the particle size of the diamond particles used. It is expected that abrasive grains aggregated during the fiber manufacturing process.

Example 13
The diamond particles used in Example 1 were blended with polyvinyl alcohol having a water content of 50% by weight (PVA; manufactured by Kuraray Co., Ltd., EC117), discharged from a nozzle at a spinning temperature of 110 ° C., dried, and 6 times at 200 ° C. To obtain a dry-spun fiber having a diamond content of 10% by weight and a single fiber fineness of 2.5 dtex. This fiber was cut and flocked in the same manner as in Example 1 to obtain an abrasive. Table 1 shows the results of the polishing performance evaluation. In this example, when the size of the abrasive grains present in the polishing fiber was observed from the size of the projections by an electron micrograph, a value almost the same as the particle size of the diamond particles used was obtained, and the production of the fiber In the middle, it was confirmed that almost no aggregation of particles occurred.

Example 14
After the diamond particles used in Example 1 are dispersed in water, mixed with a PVA aqueous solution so as to be 20% by weight with respect to PVA used in Example 13, discharged from a nozzle into an alkaline coagulation bath, dried and stretched. A wet-spun fiber having a short fiber fineness of 2 dtex was obtained by acetalization. This fiber was cut and flocked in the same manner as in Example 1 to obtain an abrasive. Table 1 shows the results of the polishing performance evaluation. In this example, when the size of the abrasive grains present in the polishing fiber was observed from the size of the protrusions obtained by an electron micrograph, a value almost the same as the particle size of the diamond particles used was obtained. That is, it was confirmed that almost no particle aggregation occurred during the production of the fiber.

Claims (11)

  A polishing fiber, comprising diamond particles and a hydrophilic resin, wherein the diamond particles have a hydrophilic group on the surface.   The abrasive fiber according to claim 1, wherein diamond particles are partially embedded in the hydrophilic resin, and the hydrophilic resin covers 50% or more of the fiber surface.   The polishing fiber according to claim 1, wherein the diamond particles have an average particle size of 1 μm or less.   The polishing fiber according to claim 1, wherein the hydrophilic group is at least one group selected from a carboxyl group, a carbonyl group, an amino group, a hydroxyl group, a sulfonyl group, a nitrate group, and a nitrite group.   The abrasive fiber according to claim 1, wherein the diamond particles are particles obtained by decomposing and removing impurities from synthetic diamond obtained by an explosion method.   The polishing fiber according to claim 2, wherein the hydrophilic resin is at least one selected from the group consisting of vinyl resins and polyamide resins.   The polishing fiber according to claim 1, which is a core-sheath type composite fiber having a sheath part made of a hydrophilic resin containing diamond particles.   The polishing fiber according to claim 7, wherein the core is composed of a thermotropic liquid crystal polymer.   The polishing fiber according to claim 1, wherein the average fiber diameter is 1 dtex or less.   An abrasive comprising the polishing fiber according to claim 1.   The abrasive according to claim 10, wherein the diamond particles have an average particle diameter of 1 µm or less and are used for precision polishing.