JP7031190B2 - Polishing film and method for manufacturing the polishing film - Google Patents

Description

The present invention relates to a polishing film, and more specifically, an optical connector ferrule, a semiconductor wafer, flattening at the time of forming an integrated circuit of a semiconductor, a metal, ceramics, a color filter (for liquid crystal display, etc.), a plasma display, an optical lens, and the like. Polishing films for polishing the surface and end faces of precision parts such as magnetic disks or optical disk substrates, magnetic heads, and optical reading heads, especially high-durability polishing films for polishing the end faces of optical connector ferrules, and methods for manufacturing them. Is.

Conventionally, the quality of precision parts such as optical connector ferrules and semiconductor wafers depends on the accuracy of the final finishing polishing process, and the final finishing polishing is performed by polishing called mechanical polishing. ..
In this mechanical polishing, first, abrasive particles having a particle diameter of 5 to 300 nm are suspended in an alkaline solution such as caustic soda, ammonia, ethanolamine, etc. to prepare an abrasive solution consisting of a colloidal solution having a pH of 9 to 12, and then a polishing solution is prepared. While supplying this polishing solution onto a polishing cloth made of a resin sheet such as polyurethane, precision parts such as optical connector ferrules and semiconductor wafers are polished on the polishing cloth.

In mechanical polishing using such a polishing liquid and a polishing cloth, the concentration of the polishing material particles in the polishing liquid changes during polishing, or the particle size distribution of the polishing material particles changes due to the aggregation of the polishing material particles. Therefore, polishing scratches and polishing spots may occur on the object to be polished such as an optical connector ferrule and a semiconductor wafer. Further, after the polishing is completed, a step of washing and removing the abrasive particles adhering to the surface of the object to be polished such as an optical connector ferrule and a semiconductor wafer is required, which has a drawback that the polishing step is complicated.

On the other hand, the base material for a polishing film made of a plastic film is coated with a coating agent in which abrasive particles are dispersed in a resin solution for a binder (also referred to as a binder) and dried. , It is considered to form a polishing layer to produce a polishing film.
Optical connector ferrules, semiconductor wafers, etc. are polished on this polishing film, but when producing a polishing film, it is difficult to uniformly disperse the polishing material particles with a particle diameter of 1 μm or less in the resin solution for the binder, and the final finish. There was a drawback that it could not be used as a polishing film for use.

That is, high-precision polishing of the final finish is performed by polishing with fine abrasive particles, but the surface energy of the abrasive particles increases as the particle size decreases and the abrasive particles tend to aggregate, so that the fine abrasive particles are likely to aggregate. Has the drawback that it is difficult to evenly disperse the particles in the binder. Further, when the polishing layer is formed by a coating agent containing agglomerated abrasive particles, coarse particles of 5 to 10 μm are generated in the polishing layer, which causes polishing scratches on the surface of the object to be polished. It had the drawback of being unavoidable.

Further, the polishing film has a drawback that it can be used only once or twice, cannot be used repeatedly many times, lacks durability, and is inferior in energy saving.

Therefore, the polishing film does not generate coarse particles of 5 to 10 μm in the polishing layer, can reduce the occurrence of polishing scratches on the surface of the object to be polished, can be used for high-precision polishing of the final finish, and is used many times repeatedly. Durability that can be done is required. The coating agent for the polishing film is required to uniformly disperse even fine abrasive particles having a small particle size and easily agglomerating in the binder. As a method for producing a polishing film, there is a demand for a manufacturing method capable of forming a stable and uniform polishing layer by using a coating agent containing dispersed abrasive particles even when the polishing layer is formed by a coating method. ..

It is possible to accurately perform precision component mirror finishing such as the end face of an optical connector ferrule and the surface of a semiconductor wafer by allowing only fine abrasive particles to exist without the presence of abrasive particles composed of coarse particles in the abrasive layer. Abrasive films are known, but they can only be used once or twice for finishing, and from the viewpoint of energy saving, they cannot be used repeatedly many times, leading to the invention of a highly durable abrasive film. There is a point. (See Patent Documents 1 and 2.)

Patent No. 3305557 Patent No. 3279912

An object of the present invention is that it has high durability, can be used many times repeatedly, does not damage the polishing layer during polishing, does not peel off from the base material, and has little decrease in polishing efficiency, especially for high-precision polishing of the final finish. It is to provide a usable polishing film and the manufacturing method thereof.

As a result of various studies, the present inventor has a polishing film having a structure in which a base material layer and a polishing layer are laminated via a primer layer, and the primer layer is formed from a primer organic resin composition. The polishing film is made of a resin composition containing inorganic nanoparticles and a silicone-based resin made of a condensate of an alkoxy group-containing silicone oligomer, so that the polishing film achieves the above object. I found it.

The present invention is characterized by the following points.
1. 1. A polishing film having a structure in which a base material layer and a polishing layer are laminated via a primer layer.
The polishing layer contains inorganic nanoparticles and a silicone-based resin made of a condensate of an alkoxy group-containing silicone oligomer.
The average particle size of the inorganic nanoparticles is 1 nm or more and 100 nm or less.
The content of the inorganic nanoparticles in the polishing layer is 80% by mass or more and 99.7% by mass or less.
The primer layer is formed from a primer organic resin composition.
Polishing film.
2. 2. The polishing film according to 1 above, wherein the thickness of the primer layer is 10 nm or more and 200 nm or less.
3. 3. The polishing film according to 1 or 2 above, wherein the primer organic resin composition contains a polyester resin.
4. The polishing film according to 3 above, wherein the polyester resin is a polyester resin having a functional group.
5. The polishing film according to 4 above, wherein the functional groups are a hydroxyl group and a carboxyl group.
6. The polishing film according to any one of 1 to 5 above, wherein the primer organic resin composition is a thermosetting organic resin composition.
7. The polishing film according to any one of 1 to 6 above, wherein the primer organic resin composition is a thermosetting organic resin composition containing a polyester resin having a hydroxyl group and a carboxyl group and an isocyanate compound.

8. The alkoxy group-containing silicone oligomer has a methyl group, a phenyl group, and an alkoxy group.
The content of the alkoxy group in the total alkoxy group-containing silicone oligomer is 10 to 30% by mass.
The content in the total alkoxy group-containing silicone oligomer of SiO ₂ is 30 to 50% by mass.
The polishing film according to any one of 1 to 7 above.
9. The polishing film according to any one of 1 to 8 above, wherein the inorganic nanoparticles are true spherical or elliptical spherical.
10. The polishing film according to any one of 1 to 9 above, wherein the modified Mohs hardness of the inorganic nanoparticles is 7 or more and 12 or less.
11. The polishing film according to any one of 1 to 10 above, wherein the inorganic nanoparticles are one or more selected from the group consisting of silica, alumina, ceria, and zirconia.
12. The polishing film according to any one of 1 to 11 above, wherein the thickness of the polishing layer is 0.5 μm or more and 100 μm or less.
13. The method for producing a polishing film according to any one of 1 to 12 above, which comprises the following steps a to d.
Step a: A step of preparing a solution A, which is a primer organic resin composition, at 20 to 50 ° C.
Step b: A step of applying the solution A to the base material layer and heating to 50 to 120 ° C. to obtain a coating material B.
Step c: A step of preparing a solution C, which is a polishing layer resin composition, at 20 to 40 ° C.
Step d: A step of applying the solution C to the surface of the coated material B to which the solution A has been applied and dried and heating to 100 to 150 ° C. to obtain a polishing film D.
14. The method for producing a polishing film according to 13 above, wherein the method for applying the solution C in the step d is a gravure reverse method.

According to the present invention, it has high durability, can be used many times repeatedly, does not damage the polishing layer during polishing and does not peel off from the base material, has little decrease in polishing efficiency, and can be used especially for high-precision polishing of the final finish. It is possible to obtain a polishing film and a method for producing the same, which are most suitable as a film for polishing the end face of an optical fiber.

It is the schematic sectional drawing which shows an example about the layer structure of the polishing film of this invention. It is schematic cross-sectional view which shows an example of the case where the base material layer contains a printing layer about the layer structure of the polishing film of this invention. It is sectional drawing of the main part explaining the polishing of the semiconductor wafer using the polishing film of this invention. It is sectional drawing of the main part explaining the polishing of an optical connector ferrule using the polishing film of this invention.

The polishing film of the present invention will be described in detail below with reference to the drawings.
FIG. 1 is a schematic cross-sectional view showing an example of the layer structure of the polishing film of the present invention.
As shown in FIG. 1, the polishing film of the present invention has a basic structure in which a base material layer and a polishing layer are laminated via a primer layer. Further, if necessary, as shown in FIG. 2, it is possible to include a functional material layer such as a printing layer in the base material layer.

[Base layer]
As the base material layer, it is excellent in chemical or physical strength, can withstand the conditions for forming the primer layer and the polishing layer, and can be held well without impairing the characteristics of the primer layer and the polishing layer. Inorganic materials such as metals and metal oxides and organic materials such as resins, which have little dimensional change and have strength and heat resistance to withstand the mechanical load and temperature during polishing, can be used as, for example, films and sheets. .. It is also possible to include a functional material layer such as a printing layer in the base material layer.
As the base material layer, a single-layer film or a multilayer laminated film is used, but is not particularly limited, and any film used for various packaging materials can be used. From these, a suitable one is freely selected and used according to the preparation conditions and the polishing conditions of the primer layer and the polishing layer.

Specific examples of the film preferably used as the base material layer include paper, aluminum foil, cellophane, polyamide-based resin film, polyester-based resin film, olefin-based resin film, acid-modified polyolefin-based resin film, polystyrene-based resin film, and polyurethane. System-based resin film, acetal-based resin film, uniaxially or biaxially stretched film, K-coated film, for example, low-density polyethylene, medium-density polyethylene, high-density polyethylene, linear low-density polyethylene, polypropylene, polybutene, polyvinyl alcohol, Ethylene-vinyl acetate copolymer, ionomer, ethylene- (meth) acrylic acid copolymer, ethylene- (meth) acrylic acid ester copolymer, ethylene-propylene copolymer, methylpentene, polyacrylonitrile, acrylonitrile-styrene Polymer, acrylonitrile-butadiene-styrene copolymer, polycarbonate, polyvinyl chloride (PVC), polyvinylidene chloride (PVDC), vinylidene fluoride (PVDF), ethylene-tetrafluoroethylene copolymer (ETFE), polytetrafluoro Resin films made of ethylene (PTFE), polyethylene terephthalate (PET), polybutylene terephthalate, polyethylene naphthalate, etc., K-coated stretched polypropylene film, K-coated stretched nylon film, composite films made by laminating two or more of these films, etc. Be done.

Among them, uniaxially or biaxially stretched polyester films such as polyethylene terephthalate and polyethylene naphthalate, uniaxially or biaxially stretched polyamide films such as nylon 6, nylon 66 and MXD6 (polymethoxylylen adipamide), and biaxially Stretched polypropylene film (OPP) or the like can be preferably used. In particular, polyethylene terephthalate is most suitable.

The resin film or sheet used for the base material layer can be processed, heat resistant, weather resistant, mechanical properties, dimensional stability, antioxidant, slipperiness, releasability, flame retardancy, and anti resistance, if necessary. Plastic compounding of lubricants, cross-linking agents, antioxidants, UV absorbers, light stabilizers, fillers, reinforcing agents, antistatic agents, pigments, etc. for the purpose of improving and modifying mold properties, electrical properties, strength, etc. Agents, additives and the like can be added, and the amount thereof can be arbitrarily added according to the purpose within a range that does not adversely affect other performance.

The thickness of the base material layer can be arbitrarily selected, but from the viewpoint of durability, it is preferably 10 μm or more and 300 μm or less, more preferably 20 μm or more and 200 μm or less, and particularly preferably 50 μm or more and 100 μm or less. If it is thinner than the above range, the strength is insufficient, and if it is thicker than the above range, the rigidity becomes too high, which may make processing difficult.

For the film or sheet of the base material layer, for example, one kind or two or more kinds of resins selected from the above-mentioned resin group are used, and the extrusion method, the cast molding method, the T-die method, the cutting method, the inflation method, etc. have been conventionally used. It can be produced by the film-forming method used, or by the multi-layer co-extrusion film-forming method using two or more kinds of resins. Further, from the viewpoint of film strength, dimensional stability, and heat resistance, for example, a tenter method, a tubular method, or the like can be used to stretch the film in the uniaxial or biaxial direction.

[Primer layer]
The primer layer is interposed between the polishing layer and the base material layer to bond both layers. The presence of the primer layer prevents the polishing layer from peeling off from the base material during polishing, enabling repeated and stable polishing work.
Since the primer layer is formed from the primer organic resin composition, the polishing layer and the base material layer are more firmly adhered to each other than in the case of a normal non-organic resin-based primer.

The primer organic resin composition may be either a thermoplastic resin composition or a thermosetting resin composition. In the case of a thermosetting resin composition, the hardness and adhesiveness of the primer layer are further improved, the polishing layer and the base material layer are adhered more firmly, and the mechanism is not clear, but the durability of the polishing film is high. It is possible to improve it, and it is considered possible to improve the polishability by applying a wide range of polishing conditions.
The primer organic resin composition contains an organic resin and a solvent, and may further contain a curing agent, if necessary. Further, if necessary, a curing accelerator, a cross-linking agent, a leveling agent, or the like may be contained.

Examples of the organic resin or curing agent include polyester resin, isocyanate resin, polyamide resin, polyvinyl chloride resin, polyvinyl acetate resin, polyacrylic or polymethacrylic resin, polyvinyl alcohol resin, and ethylene. Ethylene copolymer with vinyl acetate or acrylic acid, polyvinyl acetal resin, rubber resin, phenol resin, amino-plast resin, epoxy resin, polyurethane resin, organic silicone resin, cellulose resin and them The monomer of is mentioned. Further, each organic resin or curing agent may be a copolymer with a different kind of monomer, or may have one kind or two or more kinds of functional groups. In addition, two or more of these organic resins or curing agents can be used in combination.

As the organic resin, a polyester resin is preferable from the viewpoints of coating properties, adhesiveness, hardness, film properties, heat resistance properties, flexibility, toughness, long-term stability, etc., and a polyester resin having a hydroxyl group or a carboxyl group is preferable. Is more preferable, and a saturated copolymer polyester resin having a hydroxyl group or a carboxyl group at the molecular terminal is particularly preferable.
Although the molecular weight and softening point of the organic resin are not particularly limited, those which can form a coating film and are solid at 30 ° C. are preferable.

As the curing agent, isocyanate compounds, melamine compounds, epoxy resins and the like are preferable, and isocyanate compounds are particularly preferable. The isocyanate compound may be either aromatic or aliphatic, and may be either a small molecule compound or a high molecular weight compound. Further, those having two or more isocyanate groups in the molecule are preferable, and known diisocyanate compounds having two or more isocyanate groups, polyisocyanate compounds having three or more isocyanate groups, and the like can be used. Of these, polyisocyanate compounds are particularly preferred from the viewpoint of adhesiveness and water resistance.

Specific examples of the isocyanate compound include, for example, tetramethylene diisocyanate, hexamethylene diisocyanate, toluene diisocyanate, diphenylmethane diisocyanate, hydride diphenylmethane diisocyanate, methoxylylene diisocyanate, hydride oxylylene diisocyanate, isophorone diisocyanate, or three amounts of these isocyanate compounds. Excess amounts of the body and these isocyanate compounds, such as ethylene glycol, propylene glycol, metaxylylene alcohol, 1,3-
Low molecular weight active hydrogen compounds such as bishydroxyethylbenzene, 1,4-bishydroxyethylbenzene, trimethylolpropane, glycerol, pentaerythritol, erythritol, sorbitol, ethylenediamine, monoethanolamine, diethanolamine, triethanolamine, metaxylylene diamine and their like. Examples thereof include an adduct, a buretto, and an allophanate obtained by reacting with an alkylene oxide adduct, various polyester resins, polyether polyols, and high molecular weight active hydrogen compounds of polyamides. In addition, two or more of these curing agents can be used in combination.

The content of the curing agent is adjusted according to the functional group equivalent of the organic resin and the target physical characteristics, and may be an extremely small amount, for example, 0.1 to 30% by mass with respect to 100 parts by mass of the organic resin. It doesn't matter if it's a department.
As the curing accelerator, a known compound suitable for the type of resin or curing agent to be used is selected, and two or more of them can be used in combination.

The solvent can be used without particular limitation as long as it dissolves the organic resin used in the primer organic resin composition and has an appropriate boiling point and volatility in the manufacturing process of the polishing film of the present invention. The above can be used together.
Specific examples of the solvent include toluene, methyl ethyl ketone, ethyl acetate, cyclohexanone, petroleum-based solvents, and mixed systems thereof. Among them, ketone-based solvents and toluene are easy to handle in terms of solubility and volatility, and cost. In terms of aspects, for example, a toluene / methyl ethyl ketone mixture having a mass ratio of 1/1 is particularly preferable.

These organic resins, curing agents, curing accelerators and the like are appropriately dissolved in a solvent and mixed at 20 ° C to 50 ° C, preferably at 20 ° C to 50 ° C, in order to suppress chemical reactions and evaporation to prepare a primer organic resin composition. be able to.

The primer layer is obtained by applying the primer organic resin composition to the base material layer and drying it. Further, the curing reaction may be allowed to proceed as needed, and further, an aging treatment may be carried out as needed.

The coating method is not particularly limited, and for example, roll coat, reverse roll coat, transfer roll coat, gravure coat, gravure reverse coat, kiss coat, comma coat, rod coat, blade coat, bar coat, wire bar coat, etc. Die coat etc. can be applied. Preferably, it can be applied by a known method such as a gravure reverse method or a three-roll reverse method.

In addition, before coating, the surface of the substrate layer may be subjected to physical treatment such as corona discharge treatment, ozone treatment, low temperature plasma treatment using oxygen gas or nitrogen gas, glow discharge treatment, etc., if necessary. , Chemical treatment such as oxidation treatment using chemicals may be performed.

When it is dry, it may be heated if necessary. The heating temperature may be a sufficient temperature at which the solvent used is removed without bumping, and is preferably 50 to 120 ° C. The heating time may be a sufficient time depending on the volatility and temperature of the solvent used, and is preferably 0.5 to 10 minutes.
When the curing reaction is allowed to proceed, the curing reaction is usually promoted by heating, but depending on the type of the organic resin used, the curing reaction may be promoted by UV irradiation or electron beam irradiation. The temperature at which the curing reaction proceeds by heating is preferably 100 to 150 ° C., depending on the type of the functional group of the organic resin.
The aging conditions for performing the aging treatment are preferably 50 to 80 ° C. for 1 to 7 days.

The thickness of the primer layer is preferably 10 nm or more and 200 nm or less, more preferably 20 nm or more and 100 nm or less, and particularly preferably 30 nm or more and 70 nm or less. If it is thinner than the above range, the effect of the primer tends to be too small, and if it is thicker than the above range, aggregation failure in the primer layer tends to occur and peeling tends to occur easily.

[Abrasive layer]
In the present invention, the polishing layer is a layer containing inorganic nanoparticles as polishing particles and a silicone-based resin composed of a condensate of an alkoxy group-containing silicone oligomer as a binder, and the polishing layer resin composition is used as a primer layer. It is a layer obtained by advancing the condensation reaction by applying and drying.
The polishing layer has an appropriate hardness because inorganic nanoparticles serving as abrasive grains and a silicone resin composed of a condensate of an alkoxy group-containing silicone oligomer as a binder are uniformly dispersed in the polishing layer in an appropriate ratio. Further, other non-silicone-based resins may be contained in order to modify the chemical or physical properties.

The abrasive layer resin composition contains at least inorganic nanoparticles, an alkoxy group-containing silicone oligomer, and a solvent, and further, if necessary, to modify the physical or physical properties of the rubber fine particles. It can also contain a leveling agent, other non-silicone resin, and the like.
When preparing the polishing layer resin composition, in order to suppress chemical reaction and evaporation, the compounding raw materials can be appropriately mixed and dissolved at preferably 20 ° C. to 50 ° C. to obtain a polishing layer resin composition.

The polishing layer is obtained by applying the polishing layer resin composition to the primer layer and drying it. Further, if necessary, the chemical reaction at the primer layer / polishing layer interface may be allowed to proceed, and at the same time, the curing reaction in the primer layer may be allowed to proceed, and further, aging treatment may be performed as necessary. May be good.

In the present invention, the above-mentioned polishing particles of the inorganic nanoparticles having an extremely fine particle size are obtained by using the above-mentioned silicone-based resin in the polishing layer resin composition, in the polishing layer, and in the polishing liquid. In any of the above, the state of the primary particles is maintained without agglomeration and becomes monodisperse, and has a special advantage that the state suitable for high-definition fine polishing can be maintained.

Although the reason why the inorganic nanoparticles can maintain the state of the primary particles is not clear, if the resin used as the binder resin contains a siloxane bond (Si—O bond), the inorganic nanoparticles are, for example, nanosilica. When particles are used, they both have a structure in which Si atoms are common to each other.

As a result, since both have an affinity, the above-mentioned inorganic nanoparticles can easily maintain the state of the primary particles in any of the polishing layer resin composition, the polishing layer, and the polishing liquid being polished. It is considered that it can be monodisperse.
Even in the case of inorganic nanoparticles other than nanosilica particles, it is considered that they can easily maintain the state of the primary particles and become monodisperse for the same reason because they have a common composition of being inorganic.

When water is dropped onto the polishing layer for polishing, at the same time, the silicone-based resin in the polishing layer is also polished and dissolved in the water or dispersed as fine particles, and the inorganic nanoparticles are released into the water. Abrasive particles are formed, and a polishing liquid in a slurry-like state having a stable concentration and viscosity is formed, and polishing performance can be exhibited.
In addition, the surface of the polishing layer is constantly polished with the silicone resin of the binder, inorganic nanoparticles are always released into the water, and the latest surface is always exposed, so that from the first use to after multiple uses. It exhibits a stable slurry concentration and a stable surface condition of the polishing layer, and can always exhibit stable polishing performance.

(Silicone resin)
The silicone-based resin composed of a condensate of an alkoxy group-containing silicone oligomer contained in the polishing layer in the present invention has a siloxane bond (Si—O bond) and an alkoxy group in the polishing layer resin composition before condensation. , An alkoxy group-containing silicone oligomer having a methyl group and / or a phenyl group is contained in a hydrolyzed state.

The alkoxy group-containing silicone oligomer may have a functional group other than the methoxy group, may be modified with a resin having no siloxane bond, and may be further modified with a resin having no siloxane bond. As the main chain, the side chain portion may be composed of an alkoxy group-containing silicone oligomer.
Examples of the alkoxy group include a methoxy group and an ethoxy group.
When there are many methyl groups, the hydrolysis reactivity is excellent, and when there are many phenyl groups, the compatibility with organic resins such as acrylic, epoxy and polyester is good, and having both makes the hydrolysis reaction. An alkoxy group-containing silicone oligomer having an excellent balance between properties and reactivity can be obtained.

In the hydrolyzate of the alkoxy group-containing silicone oligomer, the alkoxy group is hydrolyzed to form a silanol group, and when it is applied and dried to form a polishing layer, a dehydration condensation reaction between the silanol groups or the said A dehydration condensation reaction is allowed to proceed between the silanol group and a component having an alcoholic hydroxyl group or a phenolic hydroxyl group in the polishing layer resin composition or on the surface of the primer layer to obtain a silicone resin composed of a condensate of an alkoxy group-containing silicone oligomer. Generate.

Examples of the resin having no siloxane bond include polyester resin, polyvinyl chloride resin, polyvinyl acetate resin, polyacrylic or polymethacrylic resin, polyvinyl alcohol resin, ethylene copolymer, and polyvinyl acetal type. Examples thereof include resins, rubber resins, polyamide resins, phenol resins, amino-plast resins, epoxy resins, polyurethane resins, cellulose resins and the like.

The content of the alkoxy group in the total alkoxy group-containing silicone oligomer is preferably 10 to 30% by mass, more preferably 15 to 25% by mass. If it is less than the above range, the strength of the silicone-based resin that is the condensation product tends to be too low, and the durability of the polishing layer tends to decrease. If it is more than the above range, the silicone-based resin that is the condensation product is hard. It becomes difficult to polish due to excessive polishing, and the amount of inorganic nanoparticles released is reduced, so that it becomes difficult to form a polishing liquid in a slurry-like state having a good concentration and viscosity.

The content of the SiO ₂ content in the total alkoxy group-containing silicone oligomer is preferably 30 to 50% by mass, more preferably 35 to 45% by mass. If it is less than the above range, the affinity between the silicone-based resin, which is a condensation product, and the inorganic nanoparticles becomes low, and the inorganic nanoparticles are in the state of primary particles in the polishing layer resin composition, the polishing layer, and the polishing liquid. If it is more than the above range, the amount of the alkoxy group and the organic substituent is relatively low, so that the durability of the polishing layer is lowered.
The molecular weight of the alkoxy group-containing silicone oligomer is preferably 300 to 2000, more preferably 500 to 1500. The average degree of polymerization is preferably 20 to 200, more preferably 50 to 150.

(Inorganic nanoparticles)
In the present invention, the average particle size of the inorganic nanoparticles is preferably 1 nm or more and 100 nm or less, more preferably 5 to 50 nm, and 10 to 50 nm, particularly for finish polishing, in order to stably obtain a clean polished surface state. 30 nm is particularly preferable. If it is smaller than the above range, the polishing efficiency tends to decrease, and if it is larger than the above range, uniform dispersion in a thin polishing layer becomes difficult, and the polishing surface condition is not stable, causing polishing scratches and the like. It tends to be easier. However, in rough polishing applications, it is possible to apply not only the above range but also inorganic nanoparticles having a large average particle size according to the desired polishing.

The shape of the inorganic nanoparticles is preferably a true spherical shape or an elliptical spherical shape in order to stably obtain a clean polished surface state, and particularly preferably a true spherical shape for finish polishing. A shape with corners such as a crushed shape does not have a stable polishing surface condition and tends to easily generate polishing scratches. However, in rough polishing applications, it is possible to apply not only the above-mentioned shape but also inorganic nanoparticles having a crushed shape or other cornered shapes according to the desired polishing.
The elliptical sphere in the present invention refers to a sphere that is not a true sphere or a general shape with rounded corners.

The modified Mohs hardness of the inorganic nanoparticles is preferably 7 or more and 12 or less. If it is smaller than the above range, the polishing efficiency tends to decrease, and if it is larger than the above range, the polishing surface state is not stable and scratches and the like tend to occur easily. However, in rough polishing applications, it is possible to apply not only the above range but also inorganic nanoparticles having a large modified Mohs hardness according to the desired polishing.

Examples of the inorganic nanoparticles include alumina (aluminum oxide), titanium oxide, zirconia (zirconium oxide), ceria, lithium silicate, diamond, silicon nitride, silicon carbide, iron oxide, chromium oxide, silica (silicon oxide), and antimony oxide. Etc. are preferably used.
Among these, silica (modified Mohs hardness 7-8), alumina (12), ceria (9), which have the above-mentioned average particle size, shape, and modified Mohs hardness, are easily available, and are relatively easy to handle. ), Zirconia (11) is more preferable, and silica is particularly preferable. These inorganic nanoparticles may be used alone or in combination of two or more.

The surface of the inorganic nanoparticles may be organically modified. By organic modification, the affinity of the silicone-based resin with the organic part, the organic resin, the organic solvent, etc. is improved, the aggregation is reduced, and the uniform dispersibility in the polishing layer can be improved. It is possible to reduce scratches during polishing.

The content of the inorganic nanoparticles in the polishing layer is preferably 80% by mass or more and 99.9% by mass or less, more preferably 85% by mass or more and 99% by mass or less, and particularly preferably 86% by mass or more and 93% by mass or less. preferable. Within the above range, the rate at which the silicone-based resin in the polishing layer is polished and the rate at which the inorganic nanoparticles are released are appropriate, and a slurry with an appropriate viscosity and inorganic nanoparticle concentration can be generated, and is always stable. It is possible to demonstrate polishing performance.
If it is less than the above range, the speed at which the silicone-based resin is polished becomes too slow, the release rate of the inorganic nanoparticles becomes slow, the number of inorganic nanoparticles adsorbed from the slurry to the silicone-based resin increases, and the viscosity of the slurry becomes high. It tends to decrease and the polishing efficiency tends to decrease.
If it is more than the above range, the polishing layer becomes brittle, it becomes difficult to stably form the polishing layer, the polishing layer tends to undergo coagulation fracture during polishing, and polishing tends to become unstable.

(solvent)
There is no particular limitation as long as it can dissolve the silicone-based resin, uniformly disperse the inorganic nanoparticles, and have an appropriate boiling point and volatility in the manufacturing process of the polishing film of the present invention. Alcohol is especially good because it is easy to handle.

[Abrasive film]
As shown in FIG. 1, the polishing film of the present invention has a base material, a primer layer, and a polishing layer, and is usually manufactured by wide winding, but is wound into a tape shape cut to a desired width. In addition to taking a primer, it may have a strip shape, a circular shape, or any other desired shape, or may be formed in any shape.

The present invention will be specifically described with reference to examples.
PET film 1: S-10 (manufactured by Toray Industries, Inc., untreated PET film, thickness 75 μm) PET film 2: E5100 (manufactured by Toyobo Co., Ltd., single-sided corona-treated PET film, thickness 50 μm)
PET film 3: A4100 (PET film manufactured by Toyobo Co., Ltd., one-sided easy-adhesive treatment, thickness 100 μm)
Primer Organic Resin 1: Elitel UE-3500 (manufactured by Unitika Ltd. Saturated copolymerized polyester containing a hydroxyl group and a carboxyl group at the end of the molecular chain. Hydroxyl group value 4, acid value 1.)
Isocyanate compound 1: D-110N (manufactured by Mitsui Takeda Chemical Co., Ltd. Trimethylolpropane adduct of metaxylylene diisocyanate. Solid content: 75% by mass, NCO: 11.5% by mass.)
Alkoxy group-containing silicone oligomer 1: KR-9218 (manufactured by Shin-Etsu Chemical Co., Ltd. Silicone resin varnish, solid content 100% by mass, methoxy group content 15% by mass, SiO 2 content 40% by mass)
Alkoxy group-containing silicone oligomer 2: KR-213 (manufactured by Shin-Etsu Chemical Co., Ltd. Silicone resin varnish, solid content 100% by mass, methoxy group content 20% by mass, SiO 2 content content 38% by mass)
Inorganic nanoparticle dispersion 1: IPA-ST (manufactured by Nissan Chemical Industries, Ltd. Nanosilica silica dispersion, solid content 30% by mass, isopropyl alcohol solvent. Average particle size of nanosilica 12.5 nm.)
Inorganic nanoparticle dispersion liquid 2: IPA-ST-L (manufactured by Nissan Chemical Industries, Ltd. Nanosilica silica dispersion liquid, solid content 30% by mass, isopropyl alcohol solvent. Average particle diameter of nanosilica 45 nm.)
Inorganic nanoparticle dispersion liquid 3: YC100C-SM1 / MEK (manufactured by Admatex Co., Ltd. Nanosilica silica dispersion liquid, solid content 30% by mass, MEK solvent. Average particle diameter of nanosilica 100 nm.)
Aluminum oxide powder: (manufactured by Sigma-Aldrich Co., Ltd., average particle size 13 nm.)

(Preparation of Primer Organic Resin Composition 1)
In an environment of room temperature of 25 ° C., the following parts by mass of toluene and methyl ethyl ketone were mixed, and then the primer organic resin 1 was added and stirred to dissolve the primer organic resin composition 1.
Toluene 49.5 parts by mass Methyl ethyl ketone 49.5 parts by mass Primer Organic resin 1 1.0 parts by mass

(Preparation of Primer Organic Resin Composition 2)
In an environment of room temperature of 25 ° C., the following parts by mass of toluene and methyl ethyl ketone were mixed, and then the primer organic resin 1 and the isocyanate compound 1 were added and dissolved by stirring to prepare the primer organic resin composition 2.
Toluene 49.5 parts by mass Methyl ethyl ketone 49.5 parts by mass Primer Organic resin 1 1.0 parts by mass Isocyanate compound 1 0.4 parts by mass

(Example 1)
The following parts by mass of the alkoxy group-containing silicone oligomer 1 and the inorganic nanoparticle dispersion liquid 1 were mixed, stirred and homogenized, and the alkoxy group-containing silicone oligomer 1 was hydrolyzed to prepare a polishing layer resin composition 1.
Alkoxy group-containing silicone oligomer 1 10 parts by mass Inorganic nanoparticle dispersion 1: 200 parts by mass The primer organic resin composition 1 is coated on the surface of the PET film 1 by bar coating, and then dried at 100 ° C. for 1 minute by a dryer. Then, the solvent was removed to form a primer layer (coating amount after drying: 0.05 g / m ² ) on the PET film 1.
Then, the polishing layer resin composition 1 was applied onto the primer layer by bar coating. Then, it was dried at 120 ° C. for 1 minute with a dryer to remove the solvent to form a polishing layer (coating amount after drying: 6 g / m ² ) to obtain a polishing film.

Using the obtained polishing film, the polishability and durability were evaluated.
The content of inorganic nanoparticles in the polishing layer before and after condensation was calculated as follows.

Amount of Hydrolyze of Silicone Oligomer Containing Alkoxy Group Before Condensation:
10 × 0.85 + 10 × 0.15 × 17/31 = 8.50 + 0.82 = 9.32 parts by mass Inorganic nanoparticles amount: 200 × 0.3 = 60 parts by mass Therefore, the content of inorganic nanoparticles = 60 / (60 + 9.32) × 100 = 86.56% by mass
After condensation Amount of alkoxy group-containing silicone oligomer hydrolyzate:
10 × 0.85 + 10 × 0.15 × (16/2) / 31 = 8.5 + 0.39 = 8.89 parts by mass Inorganic nanoparticles amount: 200 × 0.3 = 60 parts by mass Therefore, the content of inorganic nanoparticles Rate = 60 / (60 + 8.89) x 100 = 87.10% by mass

(Example 2)
Each polishing film was obtained and evaluated in the same manner as in Example 1 except that the alkoxy group-containing silicone oligomer 1 was changed to the alkoxy group-containing silicone oligomer 2 according to the compounding composition in Table 1.

(Examples 3 to 9)
According to Table 1, the polishing layer resin composition was prepared in the same manner as in Example 1, and the primer organic resin composition 1 or the primer organic resin composition 2 was applied by replacing the bar coat with the gravure reverse coat, and the polishing layer resin composition was applied. Each polishing film was obtained in the same manner as in Example 1 except that the material was applied by changing from the bar coat to the gravure coat, and evaluated in the same manner.

(Comparative Examples 1 to 3)
According to the description in Table 1, a polishing film was obtained by the same operation as in Example 1 except that the substrate was surface-treated and the primer layer was not formed as described below.
Comparative Example 1: The surface on the substrate coating side remains as it is, and a polishing layer is formed without forming a primer layer.
Comparative Example 2: The surface on the substrate coating side is corona-treated to form a polishing layer without forming a primer layer.
Comparative Example 3: The surface on the base material coated side is treated with a urethane-based anchor coating agent to form a polishing layer without forming a primer layer.

[Evaluation of hardness of polishing layer]
The scratch hardness (pencil method) of the polishing layer of the polishing film was measured according to JIS K 5600-5-4 and used as the pencil hardness. H or higher was regarded as a pass.

[Evaluation of abrasiveness and durability]
The optical fiber was polished using an optical fiber polishing machine ACP-8000 (manufactured by Ogiko Sangyo Co., Ltd.). The produced polishing film was cut into a circle with a diameter of 127 mm and fixed on a rubber pad having the same size and a hardness of 60 duro.
Next, 12 optical fibers subjected to rough polishing with a diamond film on which diamond particles having an average particle diameter of 1 μm were immobilized were set in an optical fiber jig and adjusted so that a load was evenly applied at the time of polishing. Polishing was performed under three conditions of load of 300 g, 350 g, and 400 g per connector.

Then, 1 ml of water was dropped onto the polishing film, the polishing film was rotated together with the rubber pad at 60 rpm, and the polishing was performed for 30 seconds by pressing an optical fiber as one set.

(Evaluation of polishability)
After one set of polishing was completed, the degree of scratches and adhered foreign matter on the end face of the polished optical fiber was observed with a microscope at a magnification of 400 times. The evaluation result criteria for scratches and foreign matter are as follows.
◎: None ○: Almost none △: Somewhat Yes ×: Many

(Durability evaluation)
After each set of polishing, it was observed whether the polishing film had any abnormalities such as tearing. If there were no abnormalities, it was judged that the product could be used, and one set of polishing and observation of the presence or absence of abnormalities were repeated again. Polishing was performed up to 10 sets. The evaluation result criteria for the durability of the polishing film are as follows.
⊚: No tear after 10 times of polishing ○: There is tear after 8 to 9 times of polishing △: There is tear after 4 to 10 times of polishing ×: There is tear after 1 to 3 times of polishing

[Result Summary]
All examples with a primer layer showed higher pencil hardness than comparative examples without a primer layer.
In all the examples having the primer layer, the polishing layer showed good adhesion, but in the comparative example without the primer layer, in the polishing property and durability evaluation, polishing was performed immediately after the start of the first set with a load of 300 g. Since the layer was peeled off, the evaluation of polishability and durability was stopped.
Examples 3 and 4, which are similar to Examples 1 and 2 in which the primer layer does not contain a curing agent and contain a curing agent, showed better pencil hardness, abrasiveness, and durability than Examples 1 and 2. ..
Example 7 in which nanoaluminum oxide was used as the inorganic nanoparticles also showed good pencil hardness, abrasiveness, and durability.
Examples 8 and 9 having a higher content of silica particles as compared with Examples 1 and 2 showed good polishability even at a lower load, although the durability was inferior.

The main applications of the polishing film of the present invention are optical connector ferrules, semiconductor wafers, flattening when forming integrated circuits of semiconductors, metals, ceramics, color filters (for liquid crystal displays, etc.), plasma displays, optical lenses, magnetic disks. Alternatively, it can be used for precision parts such as an optical disk substrate, a magnetic head, and an optical reading head, and can be polished with high accuracy while suppressing the occurrence of scratches. However, the surface and end faces of precision parts are not particularly limited as long as they are used for high-precision polishing.

1: Polishing film 2: Polishing layer 3: Primer layer 4: Base material layer 4a: Base material layer 1
4b: Print layer 4c: Base material layer 2
5: Semiconductor wafer 6: Optical connector ferrule 7: Optical fiber 8: Cover 9: End face

Claims (10)

A polishing film having a structure in which a base material layer and a polishing layer are laminated via a primer layer.
The polishing layer contains inorganic nanoparticles and a silicone-based resin made of a condensate of an alkoxy group-containing silicone oligomer.
The average particle size of the inorganic nanoparticles is 1 nm or more and 100 nm or less.
The content of the inorganic nanoparticles in the polishing layer is 80% by mass or more and 99.9 % by mass or less.
The primer layer is formed from a primer organic resin composition, and is formed from the primer organic resin composition.
The primer organic resin composition contains a polyester resin having a hydroxyl group and a carboxyl group.
Polishing film. The polishing film according to claim 1, wherein the thickness of the primer layer is 10 nm or more and 200 nm or less. The polishing film according to claim 1 or 2 , wherein the primer organic resin composition is a thermosetting organic resin composition. The one according to any one of claims 1 to 3 , wherein the primer organic resin composition is a thermosetting organic resin composition containing a polyester resin having a hydroxyl group and a carboxyl group and an isocyanate compound. Polished film. The alkoxy group-containing silicone oligomer has a methyl group, a phenyl group, and an alkoxy group.
The content of the alkoxy group in the total alkoxy group-containing silicone oligomer is 10 to 30% by mass.
The content in the total alkoxy group-containing silicone oligomer of SiO ₂ is 30 to 50% by mass.
The polishing film according to any one of claims 1 to 4 . The polishing film according to any one of claims 1 to 5 , wherein the inorganic nanoparticles are true spherical or elliptical spherical. The polishing film according to any one of claims 1 to 6 , wherein the modified Mohs hardness of the inorganic nanoparticles is 7 or more and 12 or less. The polishing film according to any one of claims 1 to 7 , wherein the inorganic nanoparticles are one or more selected from the group consisting of silica, alumina, ceria, and zirconia. The method for producing a polishing film according to any one of claims 1 to 8 , wherein the method comprises the following steps a to d.
Step a: A step of preparing a solution A, which is a primer organic resin composition, at 20 to 50 ° C.
Step b: A step of applying the solution A to the base material layer and heating to 50 to 120 ° C. to obtain a coating material B.
Step c: A step of preparing a solution C, which is a polishing layer resin composition, at 20 to 40 ° C.
Step d: A step of applying the solution C to the surface of the coated material B to which the solution A has been applied and dried and heating to 100 to 150 ° C. to obtain a polishing film D. The method for producing a polishing film according to claim 9 , wherein the method for applying the solution C in the step d is a gravure reverse method.

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