KR100683092B1 - Abrasive Material Having Abrasive Layer of Three-Dimensional Structure - Google Patents

Abstract

To provide an abrasive material which is excellent in loading resistance and durability, allows no attachments to attach to an abraded surface even when the end surface of the optical fiber is abraded, and is particularly suited for use in abrading a hard material such as an end surface of an optical fiber connector effectively and smoothly into a predetermined shape. The present invention provides an abrasive material for abrading an end surface of an optical fiber connector into a predetermined shape, the abrasive material having a base material (101) and an abrasive layer (102) disposed on the base material, the abrasive layer having a top layer (105) comprising an abrasive composite containing abrasive grains and a binder and a foot portion (106) comprising a binder in the absence of abrasive particles, the abrasive layer having a three-dimensional structure constructed with a plurality of regularly arranged three-dimensional elements (104) having a predetermined shape. Further, the present invention provides a method for producing an abrasive material having an abrasive layer of a three-dimensional structure, the method comprising the steps of: (1) filling a mold sheet having a plurality of regularly arranged recesses, with an abrasive material coating solution containing abrasive grains, a binder, a solvent, to a predetermined depth; (2) removing the solvent from the abrasive material coating solution in the recesses by evaporation; (3) filling the recesses further with a binder; (4) laminating a base material on the mold sheet to bond the binder to the base material; and (5) hardening the binder.

Description

Abrasive Material Having Abrasive Layer of Three-Dimensional Structure

The present invention provides an abrasive having a three-dimensional abrasive layer, and more specifically, an end face of an optical fiber having a three-dimensional abrasive layer and a ferrule installed thereon, that is, an end face of an optical fiber connector, in a predetermined shape. A abrasive suitable for the following.

Conventionally, easily removable fiber optic connectors have been widely used for the connection of optical fibers in optical fiber communications networks. In the connection of the optical fiber connector, the end faces of the optical fiber ferrules, which consist of the optical fiber and the optical fiber shielding shield (ferrule), come into direct contact with each other. Therefore, the optical properties at the time of connection, in particular the connection loss, are determined by the processing properties and precision of the end face of the optical fiber.

The end face of the optical fiber ferrule is processed through many polishing steps. The quality of the end face is influenced by the processing characteristics and precision in the final finishing polishing step. That is, the main factors of the connection loss of the optical fiber are the degree of roughness of the end face and its slope.

As for the finish roughness of the end face of the optical fiber ferrule, a relationship with the particle size of the abrasive used for polishing has been reported. For example, in the case of step index type fibers, the connection loss is about 0.5 mm when the grain size of the abrasive grain is about 1 μm, whereas the connection loss is about 15 μm when the grain size of the abrasive grain is about 15 μm. Is greater than about 1.0 ms.

In observing the above relevance, in order to satisfy the standard value requiring the connection loss of the optical fiber to be less than 1 mW, abrasive grains having a particle size of 10 to 15 µm should be used, and the connection loss of the optical fiber is required to be less than 0.5 mW. It will be appreciated that fine grade abrasive grains having a particle size of less than 1 μm must be used to meet the standard.

Japanese Patent Application Laid-Open No. 09-248771 / 1997 discloses an abrasive tape for the end face of an optical fiber connector having a base material and an abrasive layer disposed on the base material, wherein the abrasive layer has an average particle size of 5 to 30. It consists of silica particles having a thickness and has a binder for connecting these abrasive particles, and the center line average roughness Ra of the surface of the polishing layer is 0.005 to 0.2 µm.

Fine grade abrasives, for example abrasive tapes for the end faces of optical fiber connectors, have a loading problem. The term "loading" means that the space between the abrasive grains is filled with abrasive dust that protrudes and suppresses abrasive properties. For example, in the case of polishing the end face of the optical fiber connector, particles of abrasive dust stay in the space between the abrasive grains and degrade the cutting ability of the abrasive grains. In addition, the liquid used as the coolant and lubricant does not function sufficiently between the abrasive and the end face of the optical fiber connector, so that a part of the polishing layer adheres to the surface of the optical fiber connector after polishing, and a cumbersome process is required to remove it.

In addition, when the fine particles are used as the abrasive grains, the time required for polishing will be long. On the other hand, as the grain size of the abrasive grains increases, the finished end face of the optical fiber connector will become rough and fail to meet the criterion for connection loss of the optical fiber. Using both methods in combination will increase the number of times the polishing step is performed.

International Patent Publications W092 / 13680 and W096 / 27189 disclose abrasives having an abrasive layer having a three-dimensional structure. The abrasive includes a substrate material and an abrasive layer disposed on the substrate material, the abrasive layer comprising an abrasive composite containing abrasive particles and a binder, wherein the abrasive layers are arranged in a plurality of regularly arranged shapes. It has a three-dimensional structure consisting of a three-dimensional member.

The abrasive is loading resistant and excellent in durability. However, since the polishing grains are uniformly dispersed throughout the polishing layer and the polishing grains located below the polishing layer do not work effectively, the manufacturing cost is high.

In addition, the abrasive having an abrasive layer having a three-dimensional structure applies an abrasive slurry containing abrasive particles and a binder to a mold sheet having a structure, overlays the base material on the mold sheet to bond the binder to the base material, and irradiates with ultraviolet rays. It is produced by curing the binder by removing the mold sheet. In this case, the polishing slurry must have sufficient fluidity to be introduced into the structure in the mold sheet. In addition, since the ultraviolet irradiation is performed after covering the polishing slurry with the base material, the polishing slurry should not contain volatile components.

Therefore, the content of abrasive grains in the polishing slurry cannot exceed the critical pigment volume concentration. Therefore, the conventional abrasive having the abrasive layer of the three-dimensional structure has a problem that the content of abrasive grain in the abrasive layer cannot be sufficiently increased.

When the particle size of the abrasive grains, the polishing means and others are compared under the same polishing conditions, the abrasive properties of the abrasive will decrease as the content of the abrasive grains decreases. In particular, in fine grade abrasives, insufficient polishing grain content will result in poor polishing efficiency and increase the time required for polishing.

Therefore, since the abrasive grain content is insufficient, the conventional abrasive having a three-dimensional abrasive layer has poor polishing characteristics, and thus, it is possible to efficiently and smoothly polish a hard material such as the end face of the optical fiber connector into a predetermined shape. Inappropriate.

The present invention is to solve the above problems of the prior art, the object of the present invention is excellent loading resistance and durability, even when polishing the end surface of the optical fiber, there is no attachment (attachment) attached to the polished surface, It is to provide an abrasive which is particularly suitable for use in grinding hard materials, such as the end faces of optical fiber connectors, efficiently and smoothly to a desired shape.

Summary of the Invention

In order to achieve the above object of the present invention, the present invention provides an abrasive for polishing an end surface of an optical fiber connector into a predetermined shape, the abrasive comprising a base material and an abrasive layer disposed on the base material. And the abrasive layer has a three-dimensional structure consisting of a plurality of regularly arranged three-dimensional members having a predetermined shape, wherein the three-dimensional member comprises (1) an abrasive composite comprising abrasive grains dispersed in a binder. Layer and (2) a foot portion comprising a binder in the absence of abrasive particles.

The present invention also provides a method for preparing a mold sheet comprising (1) filling a mold sheet having a plurality of regularly arranged recesses with an abrasive coating solution containing abrasive grains, a binder and a solvent to a predetermined depth; (2) evaporating off the solvent from the abrasive coating solution in the groove; (3) further filling the grooves with a binder in the absence of abrasive particles; (4) laminating the base material on the mold sheet to bond the binder to the base material; And (5) curing the binder to provide a method for producing an abrasive having an abrasive layer having a three-dimensional structure.

It is preferable to manufacture the abrasive | polishing material which has an abrasive layer of a three-dimensional structure by the manufacturing method mentioned above.

The above objects and features of the present invention and other further objects and features will become more fully apparent from the following detailed description taken in conjunction with the accompanying drawings.

1 is a cross-sectional view illustrating an abrasive having a three-dimensional abrasive layer in accordance with an embodiment of the present invention.

2 is a front view illustrating an abrasive having an abrasive layer of a three-dimensional structure according to an embodiment of the present invention.

3 is a front view illustrating an abrasive having an abrasive layer of a three-dimensional structure according to an embodiment of the present invention.                 

4 is a perspective sectional view illustrating an abrasive having a three-dimensional abrasive layer in accordance with an embodiment of the present invention.

5 is a front view illustrating an abrasive having an abrasive layer of a three-dimensional structure according to an embodiment of the present invention.

6A-6E are schematic diagrams illustrating the steps of producing an abrasive having an abrasive layer of a three-dimensional structure.

7 is a graph showing a change with time of polishing amount when polishing the end surface of the optical fiber connector with various abrasives.

8 is a micrograph of the end face of the optical fiber connector after polishing with the abrasive of the present invention.

9 is a micrograph of an end face of an optical fiber connector after polishing with an abrasive of the present invention.

10 is a micrograph of the end face of the optical fiber connector after polishing with the abrasive of the prior art.

11 is a photomicrograph of the end face of an optical fiber connector after polishing with an abrasive of the prior art.

12 is a micrograph of an end face of an optical fiber connector after polishing with a polishing material of the prior art.

Fig. 13 is a micrograph of an end face of an optical fiber connector after polishing with the abrasive of the present invention.                 

Fig. 14 is a micrograph of the end face of the optical fiber connector after polishing with the abrasive of the present invention.

Fig. 15 is a micrograph of the end face of the optical fiber connector after polishing with the abrasive of the prior art.

FIG. 16 is a graph showing changes with time of polishing amount when zirconia round bars are polished with various abrasives.

Fig. 17 is a micrograph of the end face of the optical fiber connector after polishing with the abrasive of the present invention.

18 is a photomicrograph of the end face of an optical fiber connector after polishing with the abrasive of the present invention.

Fig. 19 is a micrograph of the end face of the optical fiber connector after polishing with the abrasive of the present invention.

20 is a micrograph of the end face of an optical fiber connector after polishing with an abrasive of the present invention.

Fig. 21 is a micrograph of the end face of the optical fiber connector after polishing with the abrasive of the prior art.

Fig. 22 is a micrograph of the end face of the optical fiber connector after polishing with the abrasive of the prior art.

Fig. 23 is a micrograph of the end face of the optical fiber connector after polishing with the abrasive of the present invention.                 

Fig. 24 is a micrograph of the end face of the optical fiber connector after polishing with the abrasive of the present invention.

Fig. 25 is a micrograph of the end face of the optical fiber connector after polishing with the abrasive of the present invention.

1 is a cross-sectional view illustrating an abrasive having an abrasive layer having a three-dimensional structure as an embodiment of the present invention. The abrasive 100 includes a base material 101 and an abrasive layer 102 disposed on the surface of the base material 101.

Preferred examples of the base material of the present invention include polymer films, papers, fabrics, metal films, vulcanized fibers, nonwoven base materials, combinations thereof and processed articles thereof. In the case of grinding the end face of the optical fiber connector into a spherical shape, the base material is preferably flexible, thereby promoting the formation of a spherical shape. Since the base material is convenient in the manufacturing process, it is preferable to be transparent to ultraviolet rays.

For example, the base material may be a polymer film such as a polyester film. The polymer film may be underlaid with a material such as polyethylene acrylic acid to promote bonding of the abrasive composite to the base material.

The abrasive layer 102 has an abrasive composite comprising, as a constituent, a matrix of binder and abrasive grains 103 dispersed therein.

The abrasive composite is formed from a slurry containing a plurality of abrasive grains dispersed in a binder present in an uncured or ungelled state. Upon curing or gelling, the abrasive composites solidify, ie are fixed to have the desired shape and the desired structure.

The dimensions of the abrasive grains may vary depending on the type of abrasive grain or the intended use of the abrasive. For example, the dimension is from 0.01 to 1 μm, preferably from 0.01 to 0.5 μm, more preferably from 0.01 to 0.1 μm for final finish polishing, and from 0.5 to 20 μm for rough polishing in curved formation, preferably Is 0.5 to 10 μm. Preferred examples of abrasive grains of the present invention are diamond, cubic boron nitride, cerium oxide, fused aluminum oxide, heat treated aluminum oxide, sol-gel aluminum oxide, silicon carbide, chromium oxide, silica, zirconia, alumina zirconia, iron oxide, garnet And mixtures thereof. Diamond, cubic boron nitride, aluminum oxide and silicon carbide are particularly preferred for rough polishing, and silica and aluminum oxide are particularly preferred for finishing polishing.

The binder is cured or gelled to form an abrasive layer. Preferred examples of the binder include phenolic resins, resol-phenolic resins, aminoplast resins, urethane resins, epoxy resins, acrylate resins, polyester resins, vinyl resins, melamine resins, acrylated isocyanurate resins, ureas -Formaldehyde resins, isocyanurate resins, acrylated urethane resins, acrylated epoxy resins and mixtures thereof. The binder may be a thermoplastic resin. Particularly preferred examples of the binder include phenolic resins, resol-phenolic resins, epoxy resins and urethane resins.

The binder can be cured by radiation. A radiation curable binder is a binder that can be at least partially cured or at least partially polymerized by radiation energy. Depending on the binder used, energy sources such as heat, infrared radiation, electron beam irradiation, ultraviolet radiation or visible light irradiation are used.

Typically, these binders are polymerized by the free radical mechanism. Preferably, the binder is an acrylated urethane, an acrylated epoxy, an aminoplast derivative having an α, β unsaturated carbonyl group, an ethylenically unsaturated compound, an isocyanurate derivative having at least one acrylate group, at least one acrylate group Isocyanate having and mixtures thereof.

When the binder is cured by ultraviolet irradiation, a photoinitiator is required to initiate free radical polymerization. Preferred examples of photoinitiators used for this purpose are organic peroxides, azo compounds, quinones, benzophenones, nitroso compounds, acryl halides, hydrazones, mercapto compounds, pyryllium compounds, triacrylimidazoles, bisimidazoles, Chloroalkyltriazines, benzoin ethers, benzyl ketals, thioxanthones and acetophenone derivatives. Preferred photoinitiators are 2,2-dimethoxy-1,2-diphenyl-1-ethanone.

When the binder is cured by visible light irradiation, it is necessary for the photoinitiator to initiate free radical polymerization. Preferred examples of photoinitiators for this purpose are described in US Pat. No. 4,735,632, column 3, line 25 to column 4, line 10, column 5, row 1 to 7, and column 6, row 1 to 35. Is disclosed.

The weight ratio of abrasive grains to binder is generally about 1.5 to 10 parts by weight of abrasive grains, preferably about 2 to 7 parts by weight of abrasive grains, based on 1 part by weight of binder. These ratios may vary depending on the size of the abrasive grains, the type of binder used and the intended purpose of the abrasive.

For smooth and fine grinding of hard materials such as the end faces of optical fiber connectors, the concentration of the abrasive grains contained in the abrasive composites is preferably 43 to 90% by weight when the abrasive grains are made of silicon carbide, and the abrasive grains are It is 70 to 90 weight% when it consists of spherical abrasive particles, such as alumina and a silica, 37 to 90 weight% when an abrasive grain consists of an alumina, and 39 to 90 weight% when an abrasive grain consists of diamond.

The abrasive composites may include materials other than abrasive grains and binders. For example, the abrasive may include conventional additives such as coupling agents, lubricants, dyes, pigments, plasticizers, fillers, stripping agents, abrasive aids, and mixtures thereof.

The abrasive composites may comprise a coupling agent. The addition of a coupling agent can significantly reduce the covering viscosity of the slurry used to form the abrasive composites. Preferred examples of coupling agents for the present invention include organosilanes, zircoaluminates and titanates. The amount of coupling agent is generally less than 5% by weight, preferably less than 1% by weight of the binder.

The abrasive layer 102 has a three-dimensional structure composed of a plurality of regularly arranged three-dimensional members 104 having a predetermined shape. Each three-dimensional member 104 has a tetrahedral shape in which the ridges are connected at a point on the top. In this case, the angle α formed between the two ridges is generally 30 to 150 degrees, preferably 45 to 140 degrees. The three-dimensional member 104 may have a pyramid shape. In this case, the angle α formed between the two raised lines is generally 30 to 150 degrees, preferably 45 to 140 degrees.

The points on top of the three-dimensional member 104 lie on a plane that is substantially parallel to the surface of the base material over the entire area of the abrasive. In FIG. 1, the symbol h means the height of the three-dimensional member 104 from the surface of the base material. The height h is generally 2 to 300 μm, preferably 5 to 150 μm. The height deviation of the points on the top is preferably less than 20%, more preferably less than 10% of the height of the three-dimensional member.

The three-dimensional member 104 is arranged in a predetermined configuration. In FIG. 1, the three-dimensional member 104 is filled most densely. Generally, the three-dimensional member is repeated at a predetermined period. This repeating shape is unidirectional or preferably bidirectional.

The abrasive grains do not protrude above the surface of the shape of the three-dimensional member. That is, the three-dimensional member 104 is made to have a flat plane. For example, the surface roughness Ra of the surface constituting the three-dimensional member 104 is less than 2 μm, preferably less than 1 μm.

In the three-dimensional member 104, its upper end 105 performs a polishing function. In the case of polishing with an abrasive, the three-dimensional member starts to disintegrate from the upper end to reveal the unused abrasive grain. Thus, to increase the abrasive properties of the abrasive, it is possible to increase the concentration of abrasive grains in the abrasive composite located at the upper end of the three-dimensional member as much as possible so that the abrasive has higher abrasive properties to be suitable for polishing hard materials. desirable. More preferably, the concentration of abrasive grains in the abrasive composite located at the upper end of the three-dimensional member exceeds the critical pigment volume concentration.                 

In general, the critical pigment volume concentration is considered to be the pigment volume concentration at which sufficient binder is present just to coat the pigment surface to provide a continuous phase throughout the film. As used herein, the critical pigment volume concentration means the volume concentration of abrasive grain when the gap between the grains is directly filled with the binder. If the binder is a liquid, the mixture has fluidity if the concentration is below the critical pigment volume concentration, while the mixture loses fluidity if the concentration is above the critical pigment volume concentration. If the concentration of abrasive grains in the abrasive composite located at the top of the three-dimensional member is below the critical pigment volume concentration, the abrasive properties of the abrasive will be insufficient, and the abrasive will be unsuitable for polishing hard materials such as the end face of the optical fiber connector.

The foot portion 106 of the three-dimensional member, ie, the lower portion of the abrasive layer that adheres to the base material, usually does not perform a polishing function. This is because when the abrasive layer is worn down to the lower part, the abrasive is usually discarded. The base 106 of the three-dimensional member that does not perform the polishing function does not need to contain abrasive grains, so the base 106 may be made of only a binder.

By making the three-dimensional member 104 have the two-layer structure described above, the amount of relatively expensive polishing grains can be saved, and the abrasive can be provided at a lower cost. In addition, since the binder of the base 106 can be designed considering only the adhesion of the binder to the base material, hardly any adhesion failure to the base material occurs.

In Fig. 1, the symbol s means the height of the upper end portion 105 of the three-dimensional member. The height s is, for example, 5 to 95%, preferably 10 to 90% of the height h of the three-dimensional member.

2 is a front view of the abrasive. In Fig. 2, the symbol o means the base side length of the three-dimensional member. The symbol p means the distance between the tops of adjacent three-dimensional members. The length o is for example between 5 and 1000 μm, preferably between 10 and 500 μm. The distance p is for example 5 to 1000 μm, preferably 10 to 500 μm.

In other embodiments, the three-dimensional member may be tetrahedral or pyramidal in shape with its top cut off at a predetermined height. In this case, the top of the three-dimensional member is preferably formed in a triangular or quadrilateral plane parallel to the surface of the base material, and substantially all of these planes preferably lie in a plane parallel to the surface of the base material. The height of the three-dimensional member is 5 to 95%, preferably 10 to 90% of the height h of the three-dimensional member before being cut from the top. 3 is a front view of an abrasive according to the above embodiment.

In Fig. 3, the symbol o means the base side length of the three-dimensional member. The symbol u means the distance between the base sides of adjacent three-dimensional members. The symbol y means the length of one side of the top plane. The length o is for example between 5 and 2000 μm, preferably between 10 and 1000 μm. The distance u is for example 0 to 1000 μm, preferably 2 to 500 μm. The length y is for example 0.5 to 1800 μm, preferably 1 to 900 μm.

4 is a perspective cross-sectional view of an abrasive having a three-dimensional abrasive layer in accordance with another embodiment of the present invention. The abrasive 400 is an abrasive having a base material 401 and an abrasive layer 402 disposed on the surface of the base material.                 

The abrasive layer 402 has an abrasive composite containing, as a constituent, a matrix of binder and abrasive grains 403 dispersed therein.

The polishing layer 402 has a three-dimensional structure composed of a plurality of regularly arranged three-dimensional members having a predetermined shape. The three-dimensional member 404 has a prism shape formed by triangular prisms lying laterally. The angle β of the three-dimensional member 404 is generally 30 to 150 degrees, preferably 45 to 140 degrees.

The ridges on the top of the three-dimensional member 404 lie on a plane substantially parallel to the surface of the base material over the entire area of the abrasive. In FIG. 4, the symbol h means the height of the three-dimensional member from the surface of the base material. The height h is generally 2 to 600 μm, preferably 4 to 300 μm. The height deviation of the top lines is preferably less than 20%, more preferably less than 10% of the height of the three-dimensional member 404.

Like the three-dimensional member 104, the three-dimensional member 404 preferably has a two-layered structure comprising an upper end 405 made of abrasive composites and a base 406 made of a binder. In Fig. 4, the symbol s means the height of the upper end of the three-dimensional member. The height s is, for example, 5 to 95%, preferably 10 to 90% of the height h of the three-dimensional member.

In general, the three-dimensional member 404 is arranged in a stripe pattern. In Fig. 4, the symbol w means the length (width of the three-dimensional member) of the short base side of the three-dimensional member. The symbol p means the distance between the tops of adjacent three-dimensional members. The symbol u means the distance between the long base sides of adjacent three-dimensional members. The length w is, for example, 2 to 2000 mu m, preferably 4 to 1000 mu m. The distance p is for example 2 to 4000 μm, preferably 4 to 2000 μm. The distance u is for example 0 to 2000 μm, preferably 0 to 1000 μm.

The length of the three-dimensional member can extend substantially over the entire area of the abrasive. Alternatively, the length of the three-dimensional member can be cut to a suitable length. The ends of the three-dimensional member may or may not be aligned in line. The ends of the prismatic three-dimensional member can be cut at an acute angle from its base to form a house shape with four inclined surfaces. 5 is a front view of an abrasive according to the above embodiment.

The symbol l in FIG. 5 means the length of the long base side of the three-dimensional member. The symbol v means the distance of the part cut at an acute angle of the three-dimensional member. The symbol x means the distance between the short base sides of adjacent three-dimensional members. The symbols w, p and u have the same meanings as in FIG. The length (l) is for example 5 to 10000 m, preferably 10 to 5000 m. The distance v is for example 0 to 2000 μm, preferably 1 to 1000 μm. The distance (x) is for example 0 to 2000 μm, preferably 0 to 1000 μm. The length w is, for example, 2 to 2000 μm, preferably 4 to 1000 μm. The distance p is for example 2 to 4000 μm, preferably 4 to 2000 μm. The distance u is for example 0 to 2000 μm, preferably 0 to 1000 μm.

The abrasive having the abrasive layer of the three-dimensional structure of the present invention illustrated in Figs. 1 to 5 is particularly suitable for use in polishing the end face of the optical fiber connector, and can make the connection loss of the end face of the optical fiber connector extremely small. . For example, an abrasive having an abrasive layer of three-dimensional structure according to the present invention makes the connection loss of the end face of the optical fiber connector less than 1.0 kPa, or less than 0.5 kPa.

The abrasive of the present invention is preferably produced by the following method.

First, an abrasive slurry containing abrasive grains, a binder and a solvent is prepared. As used herein, the polishing slurry contains a binder, abrasive grains, and optical additives, such as photoinitiators, in an amount sufficient to make up the abrasive composite, and additionally, a volatile solvent in an amount sufficient to impart fluidity to the mixture. to be. Even when the content of abrasive grains in the abrasive composites exceeds the critical pigment volume concentration, fluidity can be maintained by allowing the polishing slurry to contain a volatile solvent.

Preferred volatile solvents are organic solvents which dissolve the binder and exhibit volatility at room temperature to 170 ° C. Specific examples of organic solvents include methyl ethyl ketone, methyl isobutyl ketone, toluene, xylene, ethanol, isopropyl alcohol, ethyl acetate, butyl acetate, tetrahydrofuran, propylene glycol monomethyl ether and propylene glycol monomethyl ether acetate . Another preferred solvent is water.

Next, a mold sheet having a plurality of regularly arranged grooves tapered toward the base is produced. The shape of the grooves can be opposite of the three-dimensional member being formed. The mold sheet may be made of metal such as nickel or plastic such as polypropylene. Thermoplastic resins, such as polypropylene, for example, are preferred because they can be embossed on a metal tool at their melting point to form grooves having a predetermined shape. In addition, when the binder is a radiation curable resin, it is preferable to use a material that transmits ultraviolet rays and visible light. 6A-6E are schematic diagrams illustrating the steps of producing an abrasive having an abrasive layer of a three-dimensional structure.

Referring to FIG. 6A, the manufactured mold sheet 601 is filled with an abrasive slurry 602. The amount of polishing slurry used to fill the mold sheet is such that the top portion 105, 405 can be formed after the solvent has evaporated and the binder has cured. In general, the amount of polishing slurry is such that its depth from the base can be such that the dimensions shown in FIGS. 1 and 4 after evaporation of the solvent.

The mold sheet can be filled with the polishing slurry by applying the polishing slurry onto the mold sheet by a coating apparatus such as a roll coater. The viscosity of the polishing slurry for application is preferably adjusted to 10 to 106 cps, in particular 100 to 105 cps.

Referring to FIG. 6B, the solvent is evaporated to remove from the polishing slurry. In carrying out this, the mold sheet filled with the polishing slurry is heated to 50 to 150 ° C. for 0.2 to 10 minutes. If the binder is a thermoplastic resin, the mold sheet can be heated at its curing temperature to simultaneously perform the curing step. If the solvent is high in volatility, the mold sheet may be left at room temperature for several minutes to several hours.

Referring to FIG. 6C, the mold sheet is further filled with a laminating binder 603 to fill the groove with the binder. The laminated binder may be the same or different than the one used to prepare the polishing slurry. Binders with good adhesion to the base material are preferred as laminated binders.

Preferred examples of laminated binders are acrylate resins, epoxy resins and urethane resins. The mold sheet may be filled with a lamination binder in the same manner as the polishing slurry.

Referring to FIG. 6D, the base material 604 is superimposed on the mold sheet 601 to allow the binder to adhere to the base material. Adhesion is performed by pressing using a lamination roll.

The binder is cured. As used herein, the term “curing” means that the binder is polymerized in the solid state. After curing, the specific shape of the abrasive layer does not change. The curing of the binder in the polishing slurry and the lamination binder introduced alone in a subsequent step may be carried out separately or simultaneously.

The binder is cured by heat, infrared radiation or by other radiation energy such as electron beam irradiation, ultraviolet radiation or visible light irradiation. The amount of radiation energy applied may vary depending on the type of binder and the radiation energy source. In general, one skilled in the art can appropriately determine the amount of radiation energy applied. The time required for curing may vary depending on the thickness, density, temperature, properties of the composition, and the like.

For example, the binder can be cured by irradiating ultraviolet (UV) from above the transparent base material.

Referring to FIG. 6E, the mold sheet is removed to produce an abrasive 606 composed of a base material 604 and an abrasive layer 605 having a three-dimensional structure. The binder can be cured after the mold sheet is removed.

The invention will be explained in more detail by the following examples. However, the present invention is not limited by these examples.

<Example 1>

An abrasive coating solution was prepared by mixing the components shown in Table 1.

ingredient Weight (g) Nonvolatile Components (%) Weight after drying (g) Diamond Polishing Grain (Particle Size: 2 to 4 μm) “LS600F 2-4” (Lands Superabrasives, Co.) 100.000 100.000 100.000 Epoxy Resin "YD-20N" (Toto Kasei Co., Ltd.) (as 50% MEK solution) 17.500 50.000 8.750 Urethane Resin Solution "EA-1443" (Daicel Kagaku Kogyo Co., Ltd.) 29.545 55.000 16.250 Methyl Ethyl Ketone (MEK) 75.000 0.000 0.000 Aerosol AY (AMERICAN CYANAMID COMPANY) (as 50% MEK solution) 1.000 50.000 0.500 Polyfunctional Isocyanate "Coronate L" (Nippon Polyurethane Kogyo Co., Ltd.) 12.564 75.000 9.423 Total amount 235.609 57.266 134.923 Abrasive Grain / Binder Ratio = 2.91 Abrasive Grain / (Binder + Additive) Ratio = 2.86

Laminated binders were prepared by mixing the components shown in Table 2.

ingredient Weight (g) Nonvolatile Components (%) Weight after drying (g) Monoacrylate Monomer "KAYARAD R-564" (Nippon Kayaku Co., Ltd.) 50.000 100.000 50.000 Diacrylate Monomer "KAYARAD R-551" (Nippon Kayaku Co., Ltd.) 50.000 100.000 50.000 Benzophenone 4.000 100.000 4.000 1,4-diazabicyclo [2.2.2] octane (DABCO) 1.000 100.000 1.000 Total amount 105.000 400 105.000

A mold sheet made of polypropylene was prepared, having a groove having the shape of an inverted three-dimensional member shown in FIG. The abrasive slurry was applied onto the mold sheet by a roll coater and dried at 50 ° C. for 5 minutes. The lamination binder was applied thereon and further laminated with a roll of 75 μm thick transparent polyester film and pressed with a roll. Ultraviolet rays were irradiated from the polyester film side to cure the laminated binder. Subsequently, the binder of the polishing slurry was cured by heating at 70 ° C. for 24 hours.

The mold sheet was removed and the product cooled to room temperature to produce an abrasive. In the abrasive, the abrasive layer had a three-dimensional structure having a prism shape arranged in the stripe pattern shown in FIG. The dimensions are shown in Table 3.

sign Dimensions (μm) h 25 s 15 w 50 p 50 u 0 β 90 °

This abrasive was cut into a circular shape having a diameter of 110 mm to prepare an abrasive disc. The end face of the optical connector ferrule was polished using the obtained polishing disk. Polishing conditions are shown in Table 4.

Grinder "OFL-12", Seiko Denshi Kogyo Co., Ltd. product Load Point 2 (about 1.5 ㎏ / ㎠) Coolant Purified water Number of samples polished 12

The change with time of polishing amount is shown in FIG. After polishing, the end face of the optical connector ferrule was observed under an electron microscope, thereby confirming a flat surface. The obtained micrograph is shown in FIG.

<Example 2>

The polishing slurry was prepared by mixing the components shown in Table 5.

ingredient Weight (g) Nonvolatile Components (%) Weight after drying (g) Diamond Polishing Grain (Particle Size: 2 to 4 μm) “LS600F 2-4” (Lands Superabrasives, Co.) 150.000 100.000 150.000 Epoxy Resin Solution "YDCN-703PEK75" (Toto Kasei Co., Ltd.) 66.670 75.000 50.003 Methyl Ethyl Ketone (MEK) 40.500 0.000 0.000 Propylene Glycol Monomethyl Ether (PGM) 34.500 0.000 0.000 2-methylimidazole (2MZ) (20% propylene glycol monomethyl ether solution) 12.501 20.000 2.500 Total amount 304.171 66.575 202.503 Abrasive Grain / Binder Ratio = 2.86 Abrasive Grain / (Binder + Additive) Ratio = 2.86

A polishing disk was produced in the same manner as in Example 1 except that the polishing slurry was used, and the end face of the optical connector ferrule was polished. The change with time of polishing amount is shown in FIG. After polishing, the end face of the optical connector ferrule was observed under an electron microscope, thereby confirming a flat surface. The obtained micrograph is shown in FIG.

Comparative Example 1

The abrasive disc "Imperial Sign Diamond Lapping Film 3 Mil 3 Micron Type H" (manufactured by Minnesota Mining and Manufacturing Co., Ltd.) was cut into a circular shape having a diameter of 110 mm to prepare an abrasive disc. The end face of the optical connector ferrule was polished in the same manner as in Example 1, except that the polishing disk was used. The change with time of polishing amount is shown in FIG. After polishing, the end face of the optical connector ferrule was observed with an electron microscope, whereby a rough surface was confirmed. The obtained micrograph is shown in FIG.

Comparative Example 2

The polishing slurry prepared in Example 1 was applied onto a polyester film having a thickness of 75 μm by a knife coater, and the solvent was evaporated to remove an abrasive layer having a thickness of 11 μm. The abrasive layer was heated at 70 ° C. for 24 hours to cure the binder. The obtained abrasive was cut out in the shape of a circle having a diameter of 110 mm to prepare an abrasive disc.

The end face of the optical connector ferrule was polished in the same manner as in Example 1, except that the polishing disk was used. The change with time of polishing amount is shown in FIG. After polishing, the end face of the optical connector ferrule was observed with an electron microscope, whereby a rough surface was confirmed. The obtained micrograph is shown in FIG.

Comparative Example 3

The polishing slurry prepared in Example 2 was applied onto a polyester film having a thickness of 75 μm by a knife coater, and the solvent was evaporated to remove an abrasive layer having a thickness of 11 μm. The abrasive layer was heated at 70 ° C. for 24 hours to cure the binder. The obtained abrasive was cut out in the shape of a circle having a diameter of 110 mm to prepare an abrasive disc.                 

The end face of the optical connector ferrule was polished in the same manner as in Example 1, except that the polishing disk was used. The change with time of polishing amount is shown in FIG. After polishing, the end face of the optical connector ferrule was observed with an electron microscope, whereby a rough surface was confirmed. The obtained micrograph is shown in FIG.

By comparing FIGS. 8 and 9 with FIG. 10, it will be understood that the abrasives of Examples 1 and 2 provide a smoother polished surface than the abrasive of Comparative Example 1, which is a conventional product. Further, by comparing FIG. 8 with FIG. 11, it will be understood that the abrasive of Example 1 provides a flatter surface than the abrasive of Comparative Example 2, which is made of the same slurry but has an abrasive layer free of three-dimensional structures. By comparing FIG. 9 with FIG. 12, it will be understood that the abrasive of Example 2 provides a flatter surface than the abrasive of Comparative Example 3, which is made of the same slurry but has an abrasive layer without a three-dimensional structure.

From the graph shown in FIG. 7, it will be understood that the abrasive disc of Example 2 exhibits higher abrasive properties than the abrasive discs of Comparative Examples 1-3.

<Example 3>

The polishing slurry was prepared by mixing the components shown in Table 6.

ingredient Weight (g) Nonvolatile Components (%) Weight after drying (g) Colloidal Silica "Snowtechs IPA-ST" (Nissan Kagaku Kogyo Co., Ltd.) 100.00 30.000 30.00 Diacrylate Monomer "KAYARAD HDDA" (Nippon Kayaku Co., Ltd.) 15.00 100.000 15.00 Photoinitiator "Irgacure 369" (CIBA-GEIGY) 0.30 100.000 0.30 Total amount 115.30 46.030 45.30 Abrasive Grain / Binder Ratio = 2.00 Abrasive Grain / (Binder + Additive) Ratio = 1.96

A mold sheet made of the same polypropylene as used in Example 1 was prepared. The abrasive slurry was applied onto the mold sheet by a roll coater and dried at 60 ° C. for 5 minutes. The laminated binder prepared in Example 1 was applied thereon and further laminated with a roll of 75 μm thick transparent polyester film and pressed with a roll. Ultraviolet rays were irradiated from the polyester film side to cure the binder. The mold sheet was removed and the product cooled to room temperature to produce an abrasive. This abrasive was cut into a circular shape having a diameter of 110 mm to prepare an abrasive disc.

In the meantime, an optical connector ferrule was prepared and its end face was subjected to the same polishing conditions as in Table 7 using the abrasive "Imperial Sign Diamond Lapping Film 3 Mil 0.5 Micron Type H" (manufactured by Minnesota Mining and Manufacturing Co., Ltd.). Polished. The end face of the optical connector ferrule was further polished using the manufactured polishing disk. Polishing conditions are shown in Table 7.

Grinder "OFL-12", Seiko Denshi Kogyo Co., Ltd. product road Point 3 (about 2 kg / ㎠) Number of samples polished 6

After polishing, the end face of the optical connector ferrule was observed under an electron microscope, thereby confirming a flat surface. The obtained micrograph is shown in FIG.

After grinding, the shape of the end face of the optical connector ferrule is measured using the "Zoom Interferometer ZX-1 Mini PMS" (manufactured by Direct Optical Research Company (DORC)), and the amount of reflected damping is reflected by the "Back Reflection Meter RM300A". It was measured using (product of JDS FITEL). The results are shown in Table 9.

<Example 4>

The polishing slurry was prepared by mixing the components shown in Table 8.

ingredient Weight (g) Nonvolatile Components (%) Weight after drying (g) Colloidal Silica "Snowtechs IPA-ST" (Nissan Kagaku Kogyo Co., Ltd.) 100.00 30.000 30.00 Diacrylate Monomer "KAYARAD HDDA" (Nippon Kayaku Co., Ltd.) 7.50 100.000 7.50 Monoacrylate Monomer "KAYARAD R-564" (Nippon Kayaku Co., Ltd.) 7.50 100.000 7.50 Photoinitiator "Irgacure 369" (CIBA-GEIGY) 0.30 100.000 0.30 Total amount 115.30 46.030 45.30 Abrasive Grain / Binder Ratio = 2.00 Abrasive Grain / (Binder + Additive) Ratio = 1.96

A polishing disk was produced in the same manner as in Example 3 except that the polishing slurry was used, and the end face of the optical connector ferrule was polished. A micrograph of the end face after polishing is shown in FIG. 14. The shape of the end face and the amount of damping reflected are shown in Table 9.

<Comparative Example 4>

An abrasive disc was produced by dipping an abrasive "Imperial Sign Diamond Lapping Film 3 Mil 0.05 Micron AO Type P" (manufactured by Minnesota Mining and Manufacturing Co., Ltd.) into a circular shape having a diameter of 110 mm. The end face of the optical connector ferrule was polished in the same manner as in Example 3, except that the polishing disk was used. A micrograph of the end face after polishing is shown in FIG. 15. The shape of the end face and the amount of damping reflected are shown in Table 9.

Comparative Example 5

The polishing slurry prepared in Example 3 was applied onto a polyester film having a thickness of 75 μm by a knife coater, and the solvent was evaporated to remove an abrasive layer having a thickness of 4 μm. A polyester film having a thickness of 31 μm was laminated on the polishing layer, and ultraviolet light was irradiated to cure the binder. The obtained abrasive was cut out in the shape of a circle having a diameter of 110 mm to prepare an abrasive disc.

The end face of the optical connector ferrule was polished in the same manner as in Example 3, except that the polishing disk was used. However, deposits accumulated on the end faces during polishing, making it impossible to perform effective polishing.

Comparative Example 6

The polishing slurry prepared in Example 4 was applied onto a polyester film having a thickness of 75 mu m by a knife coater, and the solvent was evaporated to remove an abrasive layer having a thickness of 4 mu m. A polyester film having a thickness of 31 μm was laminated on the polishing layer, and ultraviolet light was irradiated to cure the binder. The obtained abrasive was cut out in the shape of a circle having a diameter of 110 mm to prepare an abrasive disc.                 

The end face of the optical connector ferrule was polished in the same manner as in Example 3, except that the polishing disk was used. However, deposits accumulated on the end faces during polishing, making it impossible to perform effective polishing.

Abrasive samples Example 3 Example 4 Example 4 Comparative Example 4 refrigerant Pure water Pure water 2-propanol Pure water Measurement parameters Average δ Average δ Average δ Average δ Radius of curvature (mm) 15.10 1.56 17.15 3.90 18.91 5.05 14.73 0.84 Fiber height (spherical fit: nm) 28.06 7.7 9.4 8.4 -60.3 34.9 -31.5 3.9 Fiber height (flat feet: nm) 163.0 20.7 132.9 38.9 52.9 10.1 106.1 8.7 Diameter (m) 126.9 0.3 126.7 0.3 126.6 0.3 127.3 0.4 Reflected damping volume 46.1 0.2 44.7 1.1 47.3 2.2 41.7 0.5

As shown in FIGS. 13 and 14, when the abrasive of Examples 3 and 4 was used, the abrasive “Imperial Sign Diamond Lapping Film 3 Mil 0.5 Micron Type H” (manufactured by Minnesota Mining and Manufacturing Co., Ltd.) The resulting polish streaks (FIG. 10) disappeared by 60 seconds of polishing. This end face of the optical connector ferrule was very flat and finely ground, and as shown in Table 9, the amount of reflected damping was very small compared to Comparative Example 4. The abrasive of Example 4 showed very good results when polishing was carried out using 2-propanol as the coolant.

Example 5

The polishing slurry was prepared by mixing the components shown in Table 10.

ingredient Weight (g) Nonvolatile Components (%) Weight after drying (g) Diamond Polishing Grain (Particle Size: 7-10 μm) “LS600F 7-10” (Lands Superabrasives, Co.) 100.000 100.000 100.000 Epoxy Resin Solution "YDCN-703PEK75" (Toto Kasei Co., Ltd.) 46.667 75.000 35.000 Methyl Ethyl Ketone (MEK) 40.000 0.000 0.000 Aerosol AY (AMERICAN CYANAMID COMPANY) (as 50% MEK solution) 1.000 50.000 0.500 2-methylimidazole (2MZ) (20% propylene glycol monomethyl ether solution) 8.750 20.000 1.750 Total amount 196.417 69.877 137.25 Abrasive Grain / Binder Ratio = 2.72 Abrasive Grain / (Binder + Additive) Ratio = 2.69

A mold sheet made of the same polypropylene as used in Example 1 was prepared. The abrasive slurry was applied onto the mold sheet by a roll coater and dried at 70 ° C. for 5 minutes. The laminated binder prepared in Example 1 was applied thereon, and further laminated with a roll of 75 µm thick transparent polyester film and pressed with a roll. Ultraviolet rays were irradiated from the polyester film side to cure the laminated binder. Subsequently, the binder in the polishing slurry was cured by heating at 70 ° C. for 24 hours.

The product was cooled to room temperature and the mold sheet was removed to prepare an abrasive. This abrasive was cut into a circular shape having a diameter of 110 mm to prepare an abrasive disc.

Zirconia round rods (diameter: 3 mm) were polished using the prepared polishing disks. Polishing conditions are shown in Table 11.

Grinder "OFL-12", Seiko Denshi Kogyo Co., Ltd. product road Point 1 (about 2.5 ㎏ / ㎠) Coolant Purified water Number of samples polished 6

The change with time of polishing amount is shown in FIG.

Subsequently, the polishing disk was replaced with a new one, and the end face of the optical connector ferrule was polished. Polishing conditions are shown in Table 12.

Grinder "OFL-12", Seiko Denshi Kogyo Co., Ltd. product road Point 1 (about 2.5 ㎏ / ㎠) Coolant Purified water Number of samples polished 12

After polishing, the end face of the optical connector ferrule was observed under an electron microscope, thereby confirming a flat surface. Micrographs are shown in FIG. 17.

<Example 6>

An abrasive was prepared in the same manner as in Example 5 except that a mold sheet made of polypropylene having a groove having the shape of the inverted three-dimensional member shown in FIG. 5 was used. In this abrasive, the abrasive layer had a house-shaped three-dimensional structure arranged in a stripe pattern as shown in FIG. The dimensions are shown in Table 13.

sign Dimensions (μm) h * 20 μm s * 14 μm w 40 μm p 50 μm u 10 μm l 280 μm v 40 to 80 μm x 30 μm β * 90 °

The symbols h, s and β mean the height of the three-dimensional member, the height of the upper end of the three-dimensional member, and the angle shown in FIG. 4, respectively.

The obtained abrasive was cut out with a circular disk having a diameter of 110 mm to prepare an abrasive disk. The end faces of the zirconia circular rod and the optical connector ferrule were polished in the same manner as in Example 5 using the polishing disk. The change in the polishing amount of the zirconia round rod with time is shown in FIG. 16. The end face of the optical connector ferrule was observed under an electron microscope, whereby a flat surface was confirmed. The micrograph is shown in FIG. 18.

<Example 7>

The abrasive was produced in the same manner as in Example 5 except that a mold sheet made of polypropylene having a groove having the shape of the inverted three-dimensional member shown in FIGS. 1 and 2 was used. In this abrasive, the abrasive layer had the most compactly filled tetrahedral three-dimensional structure as shown in Figs. The dimensions are shown in Table 14.

sign Dimensions (μm) h 63 μm s 50 μm o 190 μm p 190 μm α 90 °

The obtained abrasive was cut out with a circular disk having a diameter of 110 mm to prepare an abrasive disk. The end faces of the zirconia circular rod and the optical connector ferrule were polished in the same manner as in Example 5 using the polishing disk. The change in the polishing amount of the zirconia round rod with time is shown in FIG. 16. The end face of the optical connector ferrule was observed under an electron microscope, whereby a flat surface was confirmed. The micrograph is shown in FIG. 19.

<Example 8>

Same manner as in Example 5 except for using a mold sheet made of polypropylene, having a groove having the shape of the inverted three-dimensional member shown in FIG. 4 and of a different kind from that used in Example 5. An abrasive was produced. In this abrasive, the abrasive layer had a prism-shaped three-dimensional structure arranged in a stripe pattern as shown in FIG. The dimensions are shown in Table 15.

sign Dimensions (μm) h 75 μm s 50 μm w 180 μm p 180 μm u 0 μm β 100 °

The obtained abrasive was cut out with a circular disk having a diameter of 110 mm to prepare an abrasive disk. The end faces of the zirconia circular rod and the optical connector ferrule were polished in the same manner as in Example 5 using the polishing disk. The change with time of the grinding | polishing amount of a zirconia round rod is shown in FIG. The end face of the optical connector ferrule was observed under an electron microscope, whereby a flat surface was confirmed. The micrograph is shown in FIG. 20.

Comparative Example 7

The abrasive disc "Imperial Sign Diamond Lapping Film 3 Mil 9 Micron Type H" (manufactured by Minnesota Mining and Manufacturing Co., Ltd.) was cut into a circular shape having a diameter of 110 mm to prepare an abrasive disc. The end faces of the zirconia circular rod and optical connector ferrule were polished in the same manner as in Example 5 except that the abrasive disk was used. The change in the polishing amount of the zirconia round rod with time is shown in FIG. 16. The end face of the optical connector ferrule was observed under an electron microscope, thereby confirming the rough surface. The micrograph is shown in FIG. 21.

<Comparative Example 8>

The polishing slurry prepared in Example 5 was applied onto a polyester film having a thickness of 75 mu m by a knife coater, and the solvent was evaporated to remove an abrasive layer having a thickness of 14 mu m. The abrasive layer was heated at 70 ° C. for 24 hours and further heated at 100 ° C. for 24 hours to cure the binder. The abrasive obtained by cooling to room temperature was cut out into a circular shape having a diameter of 110 mm to prepare an abrasive disc.

The end faces of the zirconia circular rod and the optical connector ferrule were polished in the same manner as in Example 6 except that the abrasive disk was used. The change in the polishing amount of the zirconia round rod with time is shown in FIG. 16. The end face of the optical connector ferrule was observed under an electron microscope, thereby confirming the rough surface. The micrograph is shown in FIG. 22.

Example 9

The polishing slurry was prepared by mixing the components shown in Table 16.

ingredient Weight (g) Nonvolatile Components (%) Weight after drying (g) Diamond Polishing Grain (Particle Size: 7-10 μm) “LS600F 7-10” (Lands Superabrasives, Co.) 100.000 100.000 100.000 Resol-phenolic resin (60% nonvolatile component, 20% water, 20% organic solvent) 58.333 60.000 35.000 Propylene Glycol Monomethyl Ether (PGM) 50.000 0.000 0.000 Aerosol AY (AMERICAN CYANAMID COMPANY) (as 50% MEK solution) 1.000 50.000 0.500 Total amount 209.333 64.729 135.500 Abrasive Grain / Binder Ratio = 2.86 Abrasive Grain / (Binder + Additive) Ratio = 2.82

Laminated binders were prepared by mixing the components shown in Table 17.

ingredient Weight (g) Nonvolatile Components (%) Weight after drying (g) Epoxy Resin "YD-128R" (Toto Kasei Co., Ltd.) 96.000 100.000 96.000 2-ethyl-4-methylimidazole (2E4MZ) 4.000 100.000 4.000 Total amount 100.000 100.000 100.000

A mold sheet made of the same polypropylene as used in Example 1 was prepared. The abrasive slurry was applied onto the mold sheet by a roll coater and dried at 70 ° C. for 5 minutes. The lamination binder was applied thereon and further laminated with a roll of 75 μm thick transparent polyester film and pressed with a roll. Ultraviolet rays were irradiated from the polyester film side to cure the laminated binder. Subsequently, the binder in the polishing slurry was cured by heating at 70 ° C. for 24 hours.

The product was cooled to room temperature and the mold sheet was removed. The binder in the abrasive layer was cured by further heating at 100 ° C. for 24 hours. This abrasive was cut into a circular shape having a diameter of 110 mm to prepare an abrasive disc.

The end faces of the zirconia circular rod and the optical fiber connector were polished in the same manner as in Example 5 except that the abrasive disk was used. The change in the polishing amount of the zirconia round rod with time is shown in FIG. 16. The end face of the optical fiber connector was observed with an electron microscope, whereby a flat surface was confirmed. The micrograph is shown in FIG. 23.

<Example 10>

The abrasive was prepared in the same manner as in Example 9 except that a mold sheet made of the same polypropylene as used in Example 6 was used. This abrasive was cut into a circular shape having a diameter of 110 mm to prepare an abrasive disc.

The end faces of the zirconia circular rod and the optical fiber connector were polished in the same manner as in Example 5 except that the abrasive disk was used. The change in the polishing amount of the zirconia round rod with time is shown in FIG. 16. The end face of the optical fiber connector was observed with an electron microscope, whereby a flat surface was confirmed. The micrograph is shown in FIG. 24.

<Example 11>                 

An abrasive was prepared in the same manner as in Example 9 except that a mold sheet made of polypropylene having a groove having the shape of the inverted three-dimensional member shown in FIG. 3 was used. In this abrasive, the abrasive layer had a pyramidal three-dimensional structure shown in Fig. 3 with the top cut at a predetermined height. The dimensions are shown in Table 18.

sign Dimensions (μm) h * 175 μm s * 90 μm o 250 μm u 50 μm y 150 μm α * 30 °

The symbols h, s and α respectively mean the angle formed between the height of the three-dimensional member, the height of the upper end of the three-dimensional member and the two ridges of the three-dimensional member before the upper end is cut off.

The obtained abrasive was cut out in the shape of a circle having a diameter of 110 mm to prepare an abrasive disc. The end faces of the zirconia circular rod and the optical fiber connector were polished in the same manner as in Example 5 except that the abrasive disk was used. The change in the polishing amount of the zirconia round rod with time is shown in FIG. 16. The end face of the optical fiber connector was observed with an electron microscope, whereby a flat surface was confirmed. The micrograph is shown in FIG. 25.

It will be appreciated from the graph shown in FIG. 16 that the abrasive discs of Examples 5-11 show greater abrasive properties and longer product life than the abrasive discs of Comparative Examples 7 and 8. Further, by comparing FIGS. 17 to 20 and FIGS. 23 to 25 with FIGS. 21 and 22, the abrasive disk of Comparative Example 7 in which the abrasive disks of Examples 5 to 11 were conventional products and the abrasive layer without three-dimensional structure were obtained. It will be appreciated that it provides a smoother polished surface than the abrasive disc of Comparative Example 8.

Since the present invention can be embodied in various forms without departing from the spirit of the essential features thereof, the embodiments are intended to be illustrative and not restrictive, and the scope of the present invention is defined by the appended claims rather than by the detailed description. As such, all changes that fall within the bounds and limits of the claims or the equivalents of such bounds and limits are intended to be included in the claims.

Claims (21)

(1) filling a mold sheet having a plurality of regularly arranged recesses with an abrasive coating solution containing abrasive grains, a binder and a solvent to a predetermined depth; (2) evaporating off the solvent from the abrasive coating solution in the groove; (3) further filling the grooves with a binder in the absence of abrasive particles; (4) laminating the base material on the mold sheet to bond the binder to the base material; And (5) curing the binder A manufacturing method of an abrasive having an abrasive layer of a three-dimensional structure comprising a. The method of claim 1, wherein the binder is cured by ultraviolet radiation. The method of claim 1, wherein the binder contained in the abrasive coating solution used in step (1) is a phenolic resin, aminoplast resin, urethane resin, epoxy resin, acrylate resin, acrylated isocyanurate resin, Selected from the group consisting of urea-formaldehyde resins, isocyanurate resins, acrylated urethane resins, acrylated epoxy resins, resol-phenolic resins, polyester resins, vinyl resins, melamine resins and mixtures thereof How to be. The method of claim 1, wherein the binder used in step (3) is a phenolic resin, aminoplast resin, urethane resin, epoxy resin, acrylate resin, acrylated isocyanurate resin, urea-formaldehyde resin, Isocyanurate resin, acrylated urethane resin, acrylated epoxy resin, resol-phenolic resin, polyester resin, vinyl resin, melamine resin, and mixtures thereof. An abrasive for polishing an end surface of an optical fiber connector into a predetermined shape, The abrasive has a substrate material and an abrasive layer disposed on the substrate material, The polishing layer has a three-dimensional structure consisting of a plurality of regularly arranged three-dimensional members having a predetermined shape, Wherein the three-dimensional member has (1) a top layer comprising an abrasive composite comprising abrasive grain dispersed within the binder and (2) a foot portion comprising the binder in the absence of abrasive particles. 6. The abrasive of claim 5, wherein the top of the three-dimensional member consists of points or lines parallel to the surface of the base material, and substantially all of the points or lines lie on a plane parallel to the surface of the base material. 6. The abrasive according to claim 5, wherein the concentration of abrasive grains in the top layer of said abrasive layer exceeds a critical pigment volume concentration. 6. The abrasive according to claim 5, wherein the shape of the three-dimensional member is tetrahedral or pyramidal with ridges connected at the top. 6. The abrasive of claim 5, wherein the three-dimensional member has a height of about 2 micrometers to about 300 micrometers. 10. The abrasive according to claim 9, wherein the height of the three-dimensional member changes to less than 20%. The abrasive according to claim 5, wherein the shape of the three-dimensional member is a prism shape having ridges parallel to the surface of the base material at the top. The abrasive according to claim 5, wherein the abrasive grains have a size of about 0.01 to about 1 micrometer. The abrasive according to claim 5, wherein the abrasive grains have a size of about 0.5 to about 20 micrometers. 6. The abrasive of claim 5, wherein the abrasive grain has a nominal size of about 2 to about 4 microns. 6. The abrasive of claim 5, wherein the abrasive grain has a nominal size of about 7 to about 10 micrometers. 6. The abrasive of claim 5, wherein the maximum size of the abrasive grain is about 16 micrometers. 6. The abrasive of claim 5, wherein the abrasive grains have an average size of about 7.5 to about 9.5 micrometers. The method of claim 5, wherein the binder is a phenolic resin, aminoplast resin, urethane resin, epoxy resin, acrylate resin, acrylated isocyanurate resin, urea-formaldehyde resin, isocyanurate resin, acrylic An abrasive material selected from the group consisting of a rate urethane resin, an acrylated epoxy resin, a resol-phenolic resin, a polyester resin, a vinyl resin, a melamine resin, and mixtures thereof. 6. The polishing grain according to claim 5, wherein the abrasive grain is fused aluminum oxide, heat treated aluminum oxide, silicon carbide, alumina zirconia, garnet, diamond, cubic boron nitride, silica, cerium oxide, sol-gel aluminum oxide, chromium oxide, zirconia , Iron oxide and mixtures thereof. 6. The abrasive according to claim 5, wherein the base material is flexible so that it is particularly suitable for spherically polishing the end face of the optical fiber connector. 21. The abrasive according to claim 20, wherein the abrasive can provide an end face of the optical fiber connector having a connection loss of 1.0 kPa or less.

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