JP6184766B2 - Porous laminate, adsorption buffer material, and adsorption method - Google Patents

Description

  The present invention relates to a porous laminate, an adsorption buffer material including the porous laminate, and an adsorption method using the adsorption buffer material.

  One of the means for fixing or transporting thin-film, plate- or film-like objects such as liquid crystal glass plates and multilayer ceramic capacitor green sheets. Alternatively, there is a method of sucking and conveying. The adsorption stage is provided with a porous resin body having air permeability as an adsorption buffer material on the adsorption surface. Thereby, it can prevent that a damage | wound and a contact trace arise in a to-be-adsorbed member. As such a resin porous body, a sintered molded body obtained by sintering and molding polyethylene powder may be used from the viewpoints of rigidity and cushioning properties.

  In recent years, liquid crystal and multilayer ceramic capacitors have been rapidly reduced in size and performance, and glass plates and ceramic green sheets, which are raw materials, have been reduced in thickness. For this reason, it is necessary to perform very precise adsorption fixation or adsorption conveyance. Therefore, excellent surface smoothness, strength rigidity, antistatic property and the like are also demanded as an adsorption buffer material to be attached to the adsorption stage by vacuum suction.

  As such a porous sheet having excellent surface smoothness, a porous sheet provided with a particle layer including plastic fine particles on at least one surface has been proposed (for example, see Patent Document 1). In addition, as a suction fixing plate that has excellent strength and rigidity and prevents the deformation of the sucked material, a suction fixing plate in which a mesh screen is attached to a metal plate or a resin plate having suction holes has been proposed (for example, see Patent Document 2). .) Furthermore, a porous body having sufficient antistatic properties while maintaining air permeability and strength has been proposed (see, for example, Patent Document 3).

JP 2006-26981 A Japanese Patent Laid-Open No. 9-57561 JP 2003-103723 A

  In precision parts such as liquid crystals and multilayer ceramic capacitors, the entry of foreign substances is extremely limited. Therefore, it is required not to generate foreign matter in various parts used in the manufacturing process. There is also a demand for a sintered body of resin powder used as an adsorption buffer material used during adsorption fixation and adsorption conveyance so that raw material resin powder does not fall off.

  However, the porous sheet disclosed in Patent Document 1 has not been studied for dropping off the resin powder. In addition, the film suction holding jig disclosed in Patent Document 2 has not been studied for surface smoothness. Furthermore, the porous body having antistatic properties disclosed in Patent Document 3 has not been studied on the dropping of the resin powder and the surface smoothness.

  Furthermore, the adsorption buffer material is also required to have no partial unevenness in surface smoothness, and a technique for solving all of these is required.

  The present invention has been made in view of the above-mentioned problems, has excellent surface smoothness, has little variation in surface smoothness, has antistatic properties, and further drops of raw material particles. An object of the present invention is to provide a porous laminate having no adsorption, an adsorption buffer material including the porous laminate, and an adsorption method using the adsorption buffer material.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have laminated a sheet having air permeability on at least one surface of the porous resin body and having a predetermined surface roughness and a predetermined surface low efficiency. The present inventors have found that the above-described problems can be solved by using a porous laminate, and have completed the present invention.

That is, the present invention is as follows.
[1]
Having a porous resin body (a),
Sheet (b) having air permeability, surface roughness (Ra) of 0.1 to 20 μm, and surface resistivity of 1.0 × 10 ¹² Ω or less on at least one side of the porous resin body (a) ) Are stacked,
Porous laminate.
[2]
The porous laminate according to [1], wherein the porous resin body (a) includes a polyolefin-based resin.
[3]
The porous laminate according to [2], wherein the polyolefin-based resin contains polyethylene.
[4]
The porous laminate according to [3] above, wherein the polyethylene has a density of 890 to 970 kg / m ³ .
[5]
The porous laminate according to any one of [1] to [4], wherein the porous resin body (a) includes a sintered compact of resin powder.
[6]
The porous laminate according to any one of [1] to [5], wherein the sheet (b) is any one of a woven fabric, a nonwoven fabric, and a pore sheet.
[7]
The porous laminate according to any one of [1] to [6], wherein the sheet (b) has a surface roughness (Ra) of 0.1 to 10 μm.
[8]
The porous laminate according to any one of [1] to [7], wherein the sheet (b) has a surface resistivity of 1.0 × 10 ⁶ Ω or less.
[9]
The porous laminate according to any one of [1] to [8], wherein the thickness is 0.06 to 15 mm.
[10]
The flexural modulus is 30 to 3000 MPa,
The porous laminate according to any one of [1] to [9], wherein the air flow rate is 0.3 to ³⁰ cm ³ / cm ² / s.
[11]
An adsorption buffer material comprising the porous laminate according to any one of [1] to [10] above.
[12]
An adsorption method in which a thin film is adsorbed using the adsorption buffer material according to [11] above.
[13]
The adsorption method according to [12], wherein the adsorption buffer material is attached to an adsorption surface of an adsorption stage, and a thin film is adsorbed on the adsorption buffer material.
[14]
The resin porous body (a) is attached to the adsorption surface of the adsorption stage, the sheet (b) is laminated on the resin porous body (a) to form the adsorption buffer material, and a thin film is adsorbed on the adsorption buffer material. The adsorption method according to item [12].
[15]
The adsorption method according to any one of [12] to [14], wherein the thin film is a ceramic green sheet.

  According to the present invention, there is provided a porous laminate having excellent surface smoothness, little variation in the surface smoothness, antistatic properties, and no dropping of raw material particles, and the porous An adsorption buffer material including a laminate, and an adsorption method using the adsorption buffer material can be provided.

  Hereinafter, a mode for carrying out the present invention (hereinafter referred to as “the present embodiment”) will be described in detail. The present invention is not limited to the following embodiment, and can be implemented with various modifications within the scope of the gist.

[Porous laminate]
The porous laminate according to this embodiment is
Having a porous resin body (a),
Sheet (b) having air permeability, surface roughness (Ra) of 0.1 to 20 μm, and surface resistivity of 1.0 × 10 ¹² Ω or less on at least one side of the porous resin body (a) ) Are stacked.

[Resin porous body (a)]
Although it does not specifically limit as resin which comprises the resin porous body (a), For example, a thermoplastic resin or a thermosetting resin is mentioned. The thermoplastic resin is not particularly limited. Specifically, polyolefin resin, polyester resin, polyarylate, liquid crystal polyester, polyvinyl chloride, polyvinyl alcohol, ethylene vinyl acetate, polystyrene, acrylonitrile-butadiene-styrene copolymer Examples include coalesced resin, acrylonitrile-styrene copolymer resin, polymethyl methacrylate, polyamide resin, polyacetal, polycarbonate, fluorine resin, polyether ether ketone, polyether sulfone, polyphenylene sulfide, and the like.

  In addition, the thermosetting resin is not particularly limited, and specific examples include phenol resin, urea resin, melamine resin, allyl resin, and epoxy resin.

  Among these, a thermoplastic resin is preferable from the viewpoints of formability and secondary processability. Furthermore, among thermoplastic resins, polyolefin resins represented by polyethylene and polypropylene are more preferable. When the resin porous body (a) contains a polyolefin-based resin, it becomes cheaper, has better chemical resistance and processability, and tends to have lower moisture absorption and water absorption. Such a polyolefin resin is not particularly limited, and specifically, an ethylene homopolymer such as polyethylene, or one or more of ethylene and propylene, butene-1, hexene-1, octene-1, etc. Copolymer of α-olefin, ethylene, vinyl acetate, acrylic acid, methacrylic acid, acrylic ester, methacrylic ester, etc., propylene homopolymer, and propylene, Examples thereof include copolymers with one or more α-olefins such as ethylene and butene-1.

  Among polyolefin resins, polyethylene is preferable. By using polyethylene, the cost becomes lower, the sintering molding becomes easier, the workability and chemical resistance after molding are excellent, and the hygroscopicity and water absorption of the material itself tend to be lower.

The density of polyethylene is preferably 890 to 970 kg / m ³ . From the viewpoint of imparting sufficient rigidity to the porous resin body (a), the lower limit of the density is preferably 890 kg / m ^3, more preferably 920 kg / m ^3, more preferably ^{930kg / m 3, 940kg / m} 3 Gayori Further preferred. From the viewpoint of handling ease, the upper limit of the density is preferably 970 kg / m ^3, more preferably 960 kg / m ^3. Here, the density of polyethylene can be obtained by measuring by the density gradient tube method (23 ° C.) in accordance with JIS K 7112: 1999.

The viscosity average molecular weight of polyethylene is preferably from 1,000 to 10,000,000, more preferably from 10,000 to 10,000,000, and even more preferably from 100,000 to 10,000,000. When the viscosity average molecular weight is within the above range, the flow of the resin, which is a factor that hinders the formation of pores during sintering molding, is reduced, and the fusing property between adjacent resin particles tends to be superior. A viscosity average molecular weight can be calculated | required by the method shown below, for example. First, polyethylene is dissolved in decalin (decahydronaphthalene) to prepare a plurality of solutions having different concentrations. The respective reduced viscosities (ηsp / C) of these solutions are determined in a thermostatic bath at 135 ° C. using an Ubbelohde viscometer. A linear expression of the concentration (C) and the reduced viscosity (ηsp / C) of the polymer is derived, and the intrinsic viscosity ([η]) extrapolated to the concentration 0 is obtained. From this intrinsic viscosity ([η]), the viscosity average molecular weight (Mv) can be determined according to the following formula.
Mv = 5.34 × 10 ⁴ × [η] ^1.49

  The raw material resin of the resin porous body (a) may be a mixed raw material of polyethylene having different densities and / or viscosity average molecular weights, or may be a mixed raw material of polyethylene and a raw material resin other than polyethylene.

  The resin porous body (a) preferably includes a sintered compact of resin powder. By including a sintered compact of the resin powder as described above, the rigidity and cushioning properties tend to be superior.

  The method for forming the resin porous body (a) is not particularly limited, and a known method can be used, and examples thereof include foam molding and sintering molding. In addition, it is also possible to form a porous body having continuous pores by mixing a component that can be extracted and a melted resin to form a molded body and then extracting the extractable component from the molded body. . Among these, sintering molding is performed by filling a mold with raw materials, putting it in a heating furnace maintained at a temperature above the melting point in a pressurized or non-pressurized state, and then cooling and molding from the mold. By taking out the body, a porous body having continuous pores can be more easily formed, which is more preferable. When obtaining a sheet-like porous body, molding is performed using a molding method using a mold, an extrusion molding method, a molding method in which raw material resin is deposited on an endless belt and then sintered by heating, or the molding method described above. A method of slicing or skiving the porous body is preferably used. Further, in the present embodiment, “continuous pores” refers to pores that are continuous from one surface of the molded body to another surface. The pores may be straight or curved. The pores may have uniform dimensions as a whole, or may be, for example, those whose pore sizes are changed between the surface layer and the inside, or one surface layer and another surface layer.

  When the porous resin body (a) is obtained by sintering, a powdery resin is used as the raw material resin. In this case, the average particle diameter of the raw material resin is preferably 30 μm to 1000 μm, more preferably 30 μm to 300 μm, further preferably 100 μm to 300 μm, and still more preferably 120 μm to 250 μm. When the average particle diameter of the raw material resin is within the above range, the pore diameter of the resin porous body (a) is controlled, and the air-permeable sheet (b) is sucked into the resin porous body (a) and bent. It tends to be possible to prevent the In addition, the average particle diameter of the raw material resin is a particle diameter in which the cumulative weight is 50%, that is, a median diameter, and a laser diffraction particle size distribution measuring device (“SALD-2100” manufactured by Shimadzu Corporation) is used. Methanol can be measured as a dispersion medium.

  From the viewpoint that the resin porous body (a) is excellent in handleability, the thickness is preferably 0.05 to 10 mm, more preferably 0.05 to 3 mm, and further preferably 0.1 mm to 3 mm. 0.2 to 3 mm is even more preferable. The thickness of the resin porous body (a) here may be the thickness before the sheet (b) is laminated, or the thickness of only the resin porous body (a) after the sheet (b) is laminated. It may be measured. The thickness of only the resin porous body (a) after laminating the sheet (b) is obtained by cutting the porous laminated body along the thickness direction, and cutting the cut surface with an optical microscope (manufactured by Keyence Corporation, “Microscope”). VH-Z100UR ") can be used for observation.

Similarly to the sheet (b) having air permeability, the surface resistivity of the porous resin body (a) is preferably 1.0 × 10 ¹² Ω or less, more preferably 1.0 × 10 ⁹ Ω or less, and 1.0 More preferably, it is 10 ⁶ Ω or less. When the low surface efficiency of the resin porous body (a) is within the above range, the adhesion of particles due to charging tends to be further suppressed. In addition, the surface resistivity in the range of 1.0 × 10 ⁶ Ω to 1.0 × 10 ¹² Ω can be measured by a double ring method in accordance with JIS K 6911: 1995. The surface resistivity in the range of 1.0 × 10 ⁶ Ω or less can be measured by a four-terminal method in accordance with JIS K 7194: 1994.

[Bleeding sheet (b)]
The porous laminate according to the present embodiment has air permeability on at least one surface of the porous resin body (a), the surface roughness (Ra) is 0.1 to 20 μm, and the surface resistivity is 1. A sheet (b) of 0 × 10 ¹² Ω or less is laminated. By using such a sheet (b), there is little partial variation in surface smoothness, it has excellent surface smoothness, and it is possible to further suppress the dropping of raw material particles from the resin porous body (a). it can.

  Here, “breathability” means the property that air passes from the high pressure surface side to the low pressure surface side (air) when there is a difference in air pressure between the one surface side and the opposite surface side of the sheet (b). Property).

  Although it does not specifically limit as a sheet | seat (b), A woven fabric, a nonwoven fabric, a pore sheet | seat, sponge, a porous membrane is mentioned. Among these, any of a woven fabric, a nonwoven fabric, or a pore sheet is preferable. In general, it is known that a woven fabric, a non-woven fabric, or a pore sheet has a uniform thickness and a uniform opening. By using these as a sheet (b), a certain quality is maintained and surface smoothness is maintained. It is possible to obtain a porous laminate with less partial variation.

  “Woven fabric” refers to a woven fabric made by combining fibers with a background, or a knitted fabric in which fibers are knitted. The woven fabric can be obtained by a conventionally known method.

  “Nonwoven fabric” refers to a sheet obtained by laminating and superposing fibers without being woven together and bonding them by various methods. The method for producing the nonwoven fabric is not particularly limited, and examples thereof include a wet method, a spunlace method, a melt blow method, and an electrospinning method. Among non-woven fabrics, a long-fiber non-woven fabric having excellent wear resistance and high strength is preferred because there are no falling fibers.

  The “pore sheet” refers to a sheet produced by punching holes using a punch or the like in a thin film, plate, or film sheet. The pores of the pore sheet are not particularly limited, and may be various shapes such as a polygon as well as a circle. The arrangement may also be various arrangements such as a lattice shape and a staggered shape.

  Among these, woven fabrics and pore sheets are widely used as sieve screens. Furthermore, it is widely known that fabrics made by combining fibers among woven fabrics are also used for screen printing plates.

  The material used for the sheet (b) in the case of a woven fabric or a non-woven fabric is not particularly limited. For example, polyamide-based fibers such as nylon 6, nylon 66, copolymer polyamide; polyethylene terephthalate, polybutylene terephthalate, polytrimethylene Polyester fibers such as terephthalate and copolyester; Polyolefin fibers such as polyethylene, polypropylene, and copolypropylene; Fluorine fibers such as polytetrafluoroethylene, polyvinylidin fluoride, and perfluoropolymer; Polyurethane fibers such as polyether urethane Vinylon fiber, polyvinyl chloride fiber, polyvinylidene chloride fiber, acrylic fiber, polyimide fiber, polyetherimide fiber, polyarylate fiber, polyphenylene sulfide fiber, polyvinyl Synthetic fibers typified by lucor fiber, polycarbonate fiber, polylactic acid fiber, polyoxide fiber, polyethylene oxide fiber, polystyrene fiber, polyethylene glycol derivative fiber, polyphosphazene fiber, etc .; cellulose acetate, cellulose acetate butyrate, cellulose acetate propionate, Semi-synthetic fibers represented by promixes, etc .; inorganic fibers represented by glass fibers, carbon fibers, etc .; recycled fibers represented by rayon, cupra, etc .; represented by cotton, cotton, asbestos, wool, hemp, silk, etc. Natural fibers; or metal fibers. These may be used alone or in combination of two or more. Moreover, the sheath part may be made of polyethylene, polypropylene, copolyester or the like, and the core part may be a composite fiber made of polypropylene, polyester or the like. Furthermore, the crossing portions of the fibers may be joined by melting or may be joined by an adhesive substance.

  In addition, the material used for the sheet (b) in the case of the pore sheet is not particularly limited, but for example, polyethylene, polypropylene, ethylene vinyl acetate copolymer, ethylene-vinyl alcohol copolymer, ethylene-methacrylic acid copolymer. Polyolefin resin represented by polymer, cyclic olefin copolymer, polymethylpentene, etc .; ethylene-tetrafluoroethylene copolymer, tetrafluoroethylene-hexafluoropropylene copolymer, ethylene-chlorotrifluoroethylene copolymer Fluorine resin represented by coalescence, perfluoroalkoxy fluororesin, polytetrafluoroethylene, polychlorotrifluoroethylene, polyvinylidene fluoride, polyvinyl fluoride, etc .; polyamide resin such as nylon 6, nylon 66, copolymer polyamide; polyethylene Telef Polyester resins such as rate, polybutylene terephthalate, polytrimethylene terephthalate, and copolyester; ionomer, polyurethane, cellophane, polylactic acid, triacetyl cellulose, polyether ether ketone, polyimide, polyether imide, polyarylate, polyacetal, modified Examples include polyphenylene ether, polyvinyl chloride, polyvinylidene chloride, polyphenylene sulfide, polyvinyl alcohol, polyvinyl butyral, polycarbonate, polystyrene, polyacrylonitrile and the like. These may be used alone or in combination of two or more.

  The surface roughness (Ra) of the sheet (b) used in the present embodiment is 0.1 to 20 μm, preferably 0.1 to 10 μm, more preferably 0.1 to 5 μm, and further 0.1 to 3 μm. preferable. When the surface roughness (Ra) is within the above range, the surface smoothness is less likely to be partially varied, and the surface smoothness is more excellent. Surface roughness (Ra) was measured using a stylus type surface roughness meter (“Handy Surf E-35B” manufactured by Tokyo Seimitsu Co., Ltd.), tip diameter R: 5 μm, speed: 0.6 mm / s, measurement length: It can be measured under the conditions of 12.5 mm, cut-off value λc: 2.5 mm, number of measurements: n = 5. More specifically, the surface roughness (Ra) can be measured by the method described in the examples.

  The surface roughness (Ra) of the sheet can be adjusted by the fiber diameter and the number of meshes of fibers used in the case of a woven fabric, the pore diameter in the case of a nonwoven fabric, and the shape and size of the pores in the case of a pore sheet. it can. The surface roughness (Ra) can be reduced to 20 μm or less by changing the number of meshes to 150 mesh or more if it is a plain woven fabric, although it depends on the material used. Moreover, if it is a nonwoven fabric, surface roughness (Ra) can be 20 micrometers or less by making the average pore diameter which can be measured with a palm porometer into 100 micrometers or less. In the case of a woven fabric made by combining fibers with the background, the number of meshes is preferably 150 mesh or more, more preferably 250 mesh or more, and further preferably 420 mesh or more. When the number of meshes is 150 mesh or more, the surface smoothness tends to be superior. Furthermore, the sheet | seat (b) which performed the calendar process which improves surface smoothness, and the shrink process which makes an opening part small for the textile fabric of 420 mesh or more is also preferable. By using the sheet (b) subjected to such processing, the surface smoothness tends to be further improved. Here, the “number of meshes” is the number of yarns per inch.

  On the other hand, if the sheet is a pore sheet, the surface roughness (Ra) can be reduced to 20 μm or less by setting the opening diameter to 100 μm or less, for example, if the thickness is 0.05 mm.

The surface resistivity of the sheet (b) used in the present embodiment is 1.0 × 10 ¹² Ω or less, preferably 1.0 × 10 ⁹ Ω or less, and more preferably 1.0 × 10 ⁶ Ω or less. When the surface resistivity is 1.0 × 10 ¹² Ω or less, it has antistatic properties. In addition, when the charged object comes in contact with 1.0 × 10 ⁹ Ω or less, the charge can be dissipated relatively quickly. Furthermore, it has conductivity by being 1.0 × 10 ⁶ Ω or less. In addition, the surface resistivity in the range of 1.0 × 10 ⁶ Ω to 1.0 × 10 ¹² Ω can be measured by a double ring method in accordance with JIS K 6911: 1995. The surface resistivity in the range of 1.0 × 10 ⁶ Ω or less can be measured by a four-terminal method in accordance with JIS K 7194: 1994.

As a method for controlling the surface resistivity to 1.0 × 10 ¹² Ω or less, an antistatic agent, a conductive polymer, a hydrophilic compound solution, carbon, a conductive material, a spray method, a coating method, a dipping method, or the like is used. For example, a method of supporting on the surface of the sheet (b), a method of kneading into the inside, and the like.

  Although it does not specifically limit as an antistatic agent, For example, a nonionic surfactant, anionic surfactant, a cationic surfactant, an amphoteric surfactant etc. are mentioned.

  The conductive polymer is not particularly limited, and examples thereof include polyaniline, poly (p-phenylene vinylene), poly (p-phenylene sulfide), polypyrrole, polythiophene, and polyacetylene.

  Although it does not specifically limit as a hydrophilic compound contained in a hydrophilic compound solution, For example, the alkyl-ester type | system | group of a C8-C26 polyhydric alcohol containing polyoxyethylene, an alkyl-ether type | system | group, a fatty acid amide group containing polyhydric acid is included. Examples include ethers, fatty acid monoglycerides, sorbitan ester derivatives, acetyl phosphate metal salts, alkyl sulfate metal salts, polyoxyethylene alkyl ether sulfate metal salts, alkyl sulfosuccinate metal salts, and sugar derivatives having a glucose ring.

  Although it does not specifically limit as carbon, For example, Carbon black, such as acetylene black, oil furnace black, and thermal black; Carbon fiber, such as a polyacrylonitrile type and a pitch type; Graphite etc. are mentioned. The conductive material is not particularly limited, and examples thereof include metal fine powders such as silver, copper, and nickel; metal oxides such as zinc, tin, and antimony; metal fibers such as aluminum and stainless steel.

As a method for controlling the surface resistivity to 1.0 × 10 ⁹ Ω or less, in the method for controlling the surface resistivity to 1.0 × 10 ¹² Ω or less, an antistatic agent, a conductive polymer or a hydrophilic compound is used. Examples thereof include a method for adjusting the concentration and application amount of the solution, a method for doping using a dopant corresponding to the type of the conductive polymer, and a method for increasing the content of carbon and a conductive material.

Examples of a method for setting the surface resistivity to 1.0 × 10 ⁶ Ω or less include a method using a sheet (b) made of a metal or a metal coating.

  The material of the metal used for the sheet (b) is not particularly limited. For example, stainless steel represented by SUS304, SUS316, etc .; copper alloy represented by bronze, phosphor bronze, brass, etc .; aluminum, aluminum alloy , Gold, silver, iron, brass, copper, galvanized steel, titanium, inconel, tungsten, hastelloy, nickel and the like. These may be used alone or in combination of two or more. Also representative of graphite, molybdenum, molybdenum disulfide, tungsten carbide, cobalt carbide, nickel, manganese, titanium, tantalum, zirconium, strontium fluoride, etc., from the viewpoint of increasing hardness and improving heat resistance, corrosion resistance, and machinability Metal fluorides, barium, calcium and the like can be mixed.

  The material of the sheet (b) to which the metal coating is applied is not particularly specified. For example, the surface is represented by stainless steel represented by SUS304, SUS316, etc .; represented by bronze, phosphor bronze, brass, etc. Copper alloy: conductive carbon, copper / nickel alloy, zinc / nickel alloy, nickel / tungsten alloy, zinc / iron alloy, tin / zinc alloy, tin / silver alloy, tin / cobalt alloy, aluminum, aluminum alloy, silica, alumina , Zirconia, titanium, titanium oxide, silicon dioxide, magnesium, magnesium fluoride, platinum, gold, silver, copper, iron, zinc, cadmium, tin, palladium, nickel, chromium, hafnium, iridium, molybdenum, rhodium, ruthenium, tantalum , Cobalt, terbium, tellurium, vanadium, tungsten , Copper gallium alloy, copper-indium-gallium alloy, those coated with indium tin oxide or the like physical vapor deposition film or a chemical vapor deposition film, and the like. These may be used alone or in combination of two or more.

  In the case where the sheet (b) is a woven fabric made by combining fibers with the background, a woven fabric having conductivity anisotropy can also be used. A woven fabric having conductivity anisotropy can be realized by using metal or metal-coated yarn for warp or weft, and using chemical fiber or natural fiber for the vertical yarn.

  Since the sheet (b) has antistatic properties, it is possible to prevent adhesion of particles due to charging, and it is possible to prevent electric charges from remaining due to generation of static electricity and short circuit. When the member to be adsorbed is a silicon wafer, a probing process is usually performed to evaluate the electrical characteristics of a device formed on the processed wafer. At this time, a vertical insulated gate bipolar transistor (IGBT) is used. In a device such as a vertical metal-oxide-semiconductor field-effect transistor (MOSFET), an electrode terminal is required on the back side of the processing wafer. If the surface of the adsorption buffer material that adheres to the adsorption stage that is in contact with the processing wafer is conductive, current can flow through that surface, so that the probing process can be performed with the processing wafer installed on the adsorption stage. .

  The thickness of the sheet (b) is preferably 0.001 to 5 mm, more preferably 0.01 to 2 mm, further preferably 0.01 to 0.2 mm, and still more preferably 0.02 to 0.1 mm. When the thickness is within the above range, the handling tends to be easier and the cost tends to be better. When measuring the thickness of the sheet (b) in the porous laminate, the porous laminate is cut along the thickness direction, and the cut surface is optical microscope ("Microscope VH-Z100UR" manufactured by Keyence Corporation). It can measure by observing using ").

  The sheet (b) is very effective in the industry from the viewpoint of the stability of the area and thickness of the opening, since it is easy to produce a sheet having different porosity even in the same opening area.

[Method for producing porous laminate]
In order to laminate the resin porous body (a) and the sheet (b), they may be bonded using an adhesive or the like, or may be fused by heat.

  In order to ensure air permeability, it is preferable that the porous resin body (a) and the sheet (b) are partially bonded and / or fused by heat. Such a laminating method is not particularly limited, but includes, for example, a spray-type pressure-sensitive adhesive, a method of forming an adhesive surface such as a dot or fiber using an adhesive, a gravure coater, a roll coater, a screen printing machine, or the like. Method of forming adhesive surfaces in the form of dots, meshes, streaks, etc., method of pressurizing and fusing through a thermoplastic resin of particle shape or net shape, ultrasonic welder machine, ultrasonic sewing machine Or the like, or a method of fusing the surface of the porous resin body (a) in contact with the sheet (b) by slightly melting it. Among these, a method of forming a dotted or fibrous adhesive surface using a spray adhesive is preferable because it is simple.

  Although it does not specifically limit as a spray-type adhesive and an adhesive agent, For example, polyester-type resin, acrylic resin, polyamide-type resin, polyimide-type resin, alpha-olefin resin, polyolefin-type resin, urethane type resin, ether-type cellulose, for example , Nitrocellulose, polyvinyl acetate resin, polystyrene resin, polyvinyl alcohol resin, polyvinyl pyrrolidone resin, polyvinyl butyral resin, polybenzimidazole resin, polymethacrylate resin, melamine resin, urea resin, Resorcinol resin, ethylene vinyl acetate resin, vinyl acetate resin, epoxy resin, vinyl chloride resin, chloroprene rubber resin, styrene butadiene rubber resin, nitrile rubber resin, cyanoacrylate resin, aqueous polymer, Nate resin, silicone resin, modified silicone resin, phenol resin, fluorine resin, or ethylene vinyl acetate resin hot melt, reactive hot melt, polyamide resin hot melt, polyurethane hot melt, polyolefin hot melt, etc. Can be adopted.

  In order to laminate the porous resin body (a) and the sheet (b), a woven fabric with an adhesive can also be used. A known method (for example, described in JP-A No. 2009-167275) can be used as a production method in which the adhesive layer is provided only on the linear portion of the woven fabric.

  The thickness of the porous laminate according to this embodiment is preferably 0.06 to 15 mm, more preferably 0.06 to 5 mm, still more preferably 0.1 to 3 mm, and still more preferably 0.2 to 3 mm. When the thickness is within the above range, it tends to be superior in terms of ease of handling and cost. Here, the “thickness” is measured using a micrometer having a reading of 1/1000 mm (“MDC-SB” manufactured by Mitutoyo Corporation).

  The bending elastic modulus of the porous laminate according to this embodiment is preferably 30 to 3000 MPa, more preferably 200 to 3000 MPa, further preferably 200 to 1000 MPa, and still more preferably 200 to 800 MPa. When the bending elastic modulus is within the above range, the rigidity as an adsorption buffer material and an appropriate cushioning property tend to be excellent. Here, the “flexural modulus” is measured according to JIS K 7171: 1994 under the conditions of a test speed of 5 mm / min and a support point distance of 30 mm.

Aeration rate of the porous laminate according to the present embodiment is preferably 0.3~30cm ³ / cm ² / s, more preferably ^{0.3~10cm 3 / cm 2 / s,} 1~10cm 3 / cm 2 / S is more preferable. When the air flow rate is within the above range, the air permeability as an adsorption buffer material tends to be superior. Here, the “aeration amount” is measured using a permeability measuring device (“FX3360PORTAIR” manufactured by TEXTEST) under the conditions of a measurement range of 20 cm ² and a measurement differential pressure of 125 Pa.

[Adsorption buffer material]
The adsorption buffer material according to the present embodiment includes the porous laminate. Since the porous laminate according to the present embodiment has excellent surface smoothness, there are few partial variations in the surface smoothness, it has antistatic properties, and there is no falling off of raw material particles, it is used as an adsorption buffer material. It can be used suitably. Adsorption buffer is one of the means for fixing or transporting thin-film, plate- or film-like objects such as liquid crystal glass plates and multilayer ceramic capacitor sheets, and is a suction stage using vacuum suction. There is a method of suction fixation or suction conveyance, which is attached to the suction surface of the suction stage.

  As the adsorption buffer material, the porous laminate may be used as it is. In addition, the method of processing as an adsorption buffer material is not particularly limited, for example, when attached to the adsorption stage, if necessary, subjecting the adsorption stage or the porous laminate to partial adhesion processing, Examples include a method of cutting, fusing, and laser cutting the porous laminate into a predetermined size.

[Adsorption method]
The adsorption method according to the present embodiment includes a step of adsorbing a thin film using an adsorption buffer material. More specifically, an adsorption buffer material is attached to the adsorption surface of the adsorption stage, and a thin film, plate, or film object is adsorbed and fixed on the adsorption buffer material by vacuum suction or the like, and can be conveyed by adsorption. .

  The method for attaching the adsorption buffer material is not particularly limited. For example, an adsorption buffer material having a porous laminate in which a porous resin body (a) and a sheet (b) are laminated is attached to the adsorption surface of the adsorption stage. A method of stacking a sheet (b) on the porous resin body (a) after mounting the porous resin body (a) on the suction surface of the suction stage, and a sheet on the porous resin body (a) immediately before mounting. Examples thereof include a method of laminating (b) and a method of attaching the porous resin body (a) after attaching the sheet (b). In addition, the sheet (b) may be mounted either as a woven fabric, a nonwoven fabric or a pore sheet, or may be mounted as two or more types of multilayers.

  Here, the thin film to be fixed or conveyed is not particularly limited, and examples thereof include a ceramic green sheet. Ceramic green sheets are usually ceramic powder, binders (acrylic resin, butyral resin, etc.), plasticizers (phthalates, glycols, adipic acid, phosphates) and organic solvents (toluene, MEK, acetone). Etc.) is prepared, and this ceramic paint is applied onto a carrier sheet by the doctor blade method or the like and dried by heating.

  Multilayer ceramic capacitors are used in electronic devices and automobiles such as smartphones and tablet terminals. Not only the number of production increases, but also the performance of electronic devices and the electronic control of automobiles advance. The number of units used per vehicle is also increasing. In order to meet the growing demand and higher performance, it is extremely important in the industry to adsorb, fix and convey ceramic green sheets with high precision.

  The porous laminate according to the present embodiment can be used as an adsorption buffer material attached to the adsorption surface of the adsorption stage when performing the above-described adsorption fixation and adsorption conveyance, thereby enabling very precise adsorption fixation and adsorption conveyance. .

  Next, the present embodiment will be described more specifically with reference to examples and comparative examples. However, the present embodiment is not limited to the following examples unless it exceeds the gist.

Each physical property of each material was measured as follows.
[Measurement method of surface roughness (Ra) average and surface roughness (Ra) variation]
The surface roughness (Ra) of the porous layer laminate and the sheet (b) was measured using a stylus type surface roughness meter (“Handy Surf E-35B” manufactured by Tokyo Seimitsu Co., Ltd.), and tip diameter R: 5 μm. , Speed: 0.6 mm / s, measurement length: 12.5 mm, cut-off value λc: 2.5 mm. The measurement position was measured at a total of five locations, one at the center of the surface of the object to be measured and one at the center of the four equally divided surfaces when the surface was equally divided into four as much as possible.
The average surface roughness (Ra) was determined as the average value of the above five measurements.
The surface roughness (Ra) variation is a difference between the maximum value and the minimum value of the above five measurements, and was evaluated based on the following criteria.
○: The difference between the maximum value and the minimum value is 10% or less of the average value.
X: The difference between the maximum value and the minimum value exceeds 10% of the average value.

[Surface resistivity]
In the range of 1.0 × 10 ⁶ Ω to 1.0 × 10 ¹² Ω, the measurement of the surface resistivity of the porous layer laminate and the sheet (b) is based on JIS K 6911: 1995. Measurement was performed by a method, and in the range of 1.0 × 10 ⁶ Ω or less, measurement was performed by a four-terminal method in accordance with JIS K 7194: 1994. And it evaluated based on the following criteria.
A: 1.0 × 10 ⁶ Ω or less
○: It was larger than 1.0 × 10 ⁶ Ω and 1.0 × 10 ¹² Ω or less.
×: It was larger than 1.0 × 10 ¹² Ω.

[Dust adhesion amount]
The amount of dust adhesion was measured by measuring the weight of a single porous layer laminate having a size of 200 mm × 200 mm prepared in Examples and Comparative Examples, and then in an environment of a temperature of 26 ° C. and a humidity of 35%. 1-10 kinds of powder for JIS testing (fly ash) were placed on top of each other, and the taken porous layer laminate was vertically placed on a vibrator (“Vibrated Repacker VP-15D” manufactured by Shinko Electric Co., Ltd.). Fixed in state. After applying vibration of the vibrator for 3 seconds to the porous layered product, the weight of the porous layered product was measured, and the difference in weight between the porous layered product before and after adhering 1-10 kinds of powder for JIS test Evaluated.

[Powder removal]
The measurement of powder fall-off is performed by placing a single porous layer laminate having a size of 200 mm × 200 mm on a paper having a color opposite to that of the raw material particles of the resin porous body (a). After applying vibration for 2 minutes using Packer VP-15D "), it was visually confirmed whether or not the raw material particles were on the opposite color paper, and evaluated based on the following criteria.
A: There was almost no dropout of the raw material resin.
○: Dropping of the raw material resin was extremely small.
X: There were many dropouts of the raw material resin.

[Bending elastic modulus]
The flexural modulus was measured according to JIS K 7171: 1994 under the conditions of a test speed of 5 mm / min and a support point distance of 30 mm.

[Air flow rate]
The air flow rate was measured using an air permeability measuring device (“FX3360PORTAIR” manufactured by TEXTEST) under the conditions of a measurement range of 20 cm ² and a measurement differential pressure of 125 Pa.

[thickness]
The thickness of the porous laminate in the present embodiment was measured using a micrometer having a reading of 1/1000 mm (“MDC-SB” manufactured by Mitutoyo Corporation). In addition, the measured numerical value was measured to the third decimal place, and the value of the third decimal place was rounded off.

  The thickness of the laminated resin porous body (a) and sheet (b) is determined by cutting the laminated porous laminate along the thickness direction, and cutting the cut surface with an optical microscope (Keyence Corporation). It was measured by observing using “Microscope VH-Z100UR”. In addition, the measured numerical value was measured to the third decimal place, and the value of the third decimal place was rounded off.

[Example 1]
High-density polyethylene powder Sun Fine (trademark) SH801 (made by Asahi Kasei Chemicals Corporation, density 955 kg / m ³ ) is deposited on a metal flat plate with a thickness of 2.1 mm or more to provide a clearance of 2.1 mm from the metal flat plate. By passing through the scraped portion, the material uniformly deposited with a thickness of 2.1 mm was put into a heating furnace set at 180 ° C., allowed to stand for 10 minutes, then removed from the heating furnace, and at room temperature. By cooling, a sintered compact having a thickness of 2.0 mm was obtained as a porous resin body (a). A polyolefin hot melt adhesive was spray-coated on the porous resin body in a fibrous form at 20 g / m ² using a hot melt applicator set at 160 ° C. As sheet (b), fabric (warp / weft: polyethylene terephthalate monofilament) L-screen165-027 / 420PW subjected to antistatic treatment AS L-screen165-027 / 420PW (manufactured by NBC Meshtec Co., Ltd.) This was laminated on the resin porous body (a) to obtain a porous laminated body. Table 1 shows the characteristics of the porous laminate.

[Example 2]
As sheet (b), L-screen165-027 / 420PW (stock) instead of AS L-screen165-027 / 420PW (manufactured by NBC Meshtec Co., Ltd.) obtained by applying antistatic treatment to L-screen165-027 / 420PW A porous laminate was obtained in the same manner as in Example 1 except that woven fabric masa420 (manufactured by Sekisui Nanocoat Technology Co., Ltd.) was used. Evaluation similar to Example 1 was performed, and the measurement results are shown in Table 1.

[Example 3]
As sheet (b), instead of AS L-screen165-027 / 420PW (manufactured by NBC Meshtec Co., Ltd.) obtained by subjecting L-screen165-027 / 420PW to antistatic treatment, a woven fabric (warp / weft: stainless steel) A porous laminate was obtained in the same manner as in Example 1 except that BS-400 / 25 (manufactured by Asada Mesh Co., Ltd.) was used. Evaluation similar to Example 1 was performed, and the measurement results are shown in Table 1.

[Example 4]
As sheet (b), instead of AS L-screen165-027 / 420PW (manufactured by NBC Meshtec Co., Ltd.) obtained by subjecting L-screen165-027 / 420PW to antistatic treatment, a woven fabric (warp / weft: stainless steel) A porous laminate was obtained in the same manner as in Example 1 except that BS-200 / 40 (manufactured by Asada Mesh Co., Ltd.) was used. Evaluation similar to Example 1 was performed, and the measurement results are shown in Table 1.

[Comparative Example 1]
Using a high-density polyethylene powder Sun Fine (trademark) SH801 (manufactured by Asahi Kasei Chemicals Corporation), a sintered molded body having a thickness of 2 mm was obtained as a porous resin body in the same manner as in Example 1. The same characteristics as in Example 1 were evaluated using the resin porous material as it was without laminating the sheet (b). The results are shown in Table 1.

[Comparative Example 2]
The same operation and evaluation as in Comparative Example 1 were performed except that ultra high molecular weight polyethylene powder XM-220 (Mitsui Chemicals, Inc.) was used as the porous resin body (a). The results are shown in Table 1.

[Comparative Example 3]
Example 1 using a woven fabric (warp / weft: polyethylene terephthalate monofilament) L-screen165-027 / 420PW (manufactured by NBC Meshtec Co., Ltd.) as the sheet (b) without laminating the porous resin body (a). The same characteristics were evaluated. The results are shown in Table 1.

[Comparative Example 4]
As sheet (b), L-screen165-027 / 420PW (stock) instead of AS L-screen165-027 / 420PW (manufactured by NBC Meshtec Co., Ltd.) obtained by applying antistatic treatment to L-screen165-027 / 420PW A porous laminate was obtained in the same manner as in Example 1 except that the company NBC Meshtec) was used. Evaluation similar to Example 1 was performed, and the measurement results are shown in Table 1.

  From the results shown in Table 1, in the porous resin body having air permeability, the porous laminate formed by substantially integrating a sheet having air permeability and excellent surface smoothness on at least one side has excellent surface smoothness, It has been found that it has antistatic properties, rigidity, and air permeability, and there is little partial variation in the surface smoothness, and there is little dropout of raw material particles.

  The porous laminate of the present invention has industrial applicability in a method for fixing or transporting thin-film, plate-like, or film-like objects such as glass plates for liquid crystals and green sheets for multilayer ceramic capacitors. Have.

Claims (13)

Having a porous resin body (a),
At least one surface of the porous resin body (a) has air permeability, a surface roughness (Ra) of 4.7 to 12.9 μm, and a surface resistivity of 1.0 × 10 ¹² Ω or less. A sheet (b) that is either a woven fabric, a nonwoven fabric, or a pore sheet is laminated,
Porous laminate.   The porous laminate according to claim 1, wherein the resin porous body (a) contains a polyolefin-based resin.   The porous laminate according to claim 2, wherein the polyolefin-based resin contains polyethylene. The porous laminate according to claim ³ , wherein the polyethylene has a density of 890 to 970 kg / m ³ .   The porous laminated body of any one of Claims 1-4 in which the said resin porous body (a) contains the sintered compact of a resin powder. The porous laminate according to any one of claims 1 to 5 , wherein the sheet (b) has a surface resistivity of 1.0 x 10 ⁶ Ω or less. The porous laminate according to any one of claims 1 to 6 , wherein the thickness is 0.06 to 15 mm. The flexural modulus is 30 to 3000 MPa,
Aeration is 0.3~30cm ³ / cm ² / s, the porous laminate according to any one of claims 1-7. The adsorption buffer material containing the porous laminated body of any one of Claims 1-8 . An adsorption method for adsorbing a thin film using the adsorption buffer material according to claim 9 . The adsorption method according to claim 10 , wherein the adsorption buffer material is attached to an adsorption surface of an adsorption stage, and a thin film is adsorbed on the adsorption buffer material. The resin porous body (a) is attached to the adsorption surface of the adsorption stage, the sheet (b) is laminated on the resin porous body (a) to form the adsorption buffer material, and a thin film is adsorbed on the adsorption buffer material. The adsorption method according to claim 10 . The adsorption method according to any one of claims 10 to 12 , wherein the thin film is a ceramic green sheet.