JP4803803B2 - Manufacturing method of adsorption fixing sheet - Google Patents

Description

  The present invention relates to a method for producing a suction fixing sheet including a porous sheet, and particularly for suction fixing for suction conveyance, vacuum suction fixing, etc. in the production of glass plates for liquid crystals, semiconductor wafers or laminated ceramic capacitors. The present invention relates to a sheet manufacturing method.

  For example, in the case of an electronic component such as a ceramic capacitor configured by laminating dielectric sheets, the dielectric sheet is sucked and fixed and conveyed, and as one of the members to be further laminated, a plastic porous as a sheet for adsorbing and fixing conveyance A sheet is used.

  It has been proposed to use a porous sheet made of ultra high molecular weight polyethylene (hereinafter referred to as “UHMWPE”) having an average molecular weight of 500,000 or more in consideration of air permeability, rigidity, cushioning properties, and the like. .

  A porous sheet made of UHMWPE is generally manufactured by filling a mold with UHMWPE and sintering. However, this method is a batch production and cannot be continuous or lengthened.

  For this reason, we have proposed a characteristic method in which UHMWPE powder filled in a mold is sintered with heated steam and then cut after cooling as a method for obtaining a long porous sheet. (For example, see Patent Document 1 below).

  Since the porous sheet obtained by this method is long, it can be used for various purposes, and has a feature of high strength and excellent air permeability.

  The porous sheet produced by this method has a surface roughness of about 2.0 μm. This is due to the cutting performed during the manufacturing process. Further, for example, when a porous sheet is produced using fine particles having an average particle diameter of 30 μm or less, there is a problem that pinholes are generated or cracks are formed at the time of filling and after molding, so that molding is difficult.

  Therefore, as a countermeasure against surface roughness, a method of laminating with a plastic film and heating to smooth the surface has been proposed (see, for example, Patent Documents 2 and 3 below). By using these methods, the surface smoothness can be improved. However, more surface smoothness has been demanded recently.

  In addition, as a method for molding small-diameter particles, a dispersion liquid in which plastic particles are dispersed in a solvent is applied to a carrier sheet, dried to form a coating film, and then the contact points between the particles are fused, A method for obtaining a porous sheet by peeling is disclosed (for example, see Patent Document 4 below).

  In this method, it is possible to form small-diameter particles into a sheet. Further, the present invention is applied when the strength is lower than that of a porous sheet manufactured by cutting and the strength is not a problem. In terms of the manufacturing method, for example, it is suitable for manufacturing a thin porous sheet rather than producing a thick product exceeding 1 mm.

Further, in Patent Document 5 below, after a plastic particle is dispersed in a solvent having a boiling point higher than the melting point of the particle, a dispersion is prepared, and this dispersion is applied onto a film to form a coating layer. A method for forming a particle layer on a UHMWPE sheet having a relatively high strength by placing and transferring a porous sheet on the coating layer is described. However, in the case of continuous production, the production line for the process of placing and transferring the porous sheet on the coating layer is complicated in the case of continuous production. For this reason, manufacturing management is difficult and the equipment cost increases.
JP-B-5-66855 JP 09-174694 A JP 2001-28390 A JP 2001-172577 A JP 2006-26981 A

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a production method capable of continuously producing a sheet for adsorption and fixing excellent in surface smoothness and strength as a long and thick product. There is.

  In order to achieve the above-mentioned object, the inventors of the present application have intensively studied a method for producing a suction fixing sheet. As a result, it has been found that the object can be achieved by employing the following method, and the present invention has been completed.

  That is, in order to solve the above-described problems, the method for manufacturing a suction fixing sheet according to the present invention is used for suction fixing of a member to be sucked, and a method for manufacturing a suction fixing sheet including at least a porous sheet. A step of producing a dispersion in which plastic particles are dispersed in a solvent, a step of directly applying the dispersion on a porous sheet to form a coating layer, and placing a film on the coating layer And a step of firing the coating layer, and a step of removing the solvent contained in the coating layer to form a particle layer made of the plastic particles.

  In the conventional method for producing a sheet for adsorption and fixation, a dispersion is applied to a film to form a coating layer, and then a porous sheet is placed on the coating layer, and the coating layer is formed on the porous sheet. Transcribed. However, in this method, the production line for bonding the film coated with the dispersion to the porous sheet becomes complicated, and the production cost increases. On the other hand, in the method of the present invention, the dispersion is directly applied on the porous sheet to form a coating layer, and then a laminate is obtained simply by placing a film on the coating layer. As a result, the production line can be simplified and the production cost can be reduced. In addition, the suction fixing sheet obtained by the above method enables the contact state with the member to be sucked to be multipoint contact instead of surface contact, and reduces the effective contact area between the member to be sucked and the suction surface. Excellent peelability. Furthermore, since the sheet for adsorbing and fixing is a laminated structure in which a particle layer is formed on a porous sheet, the strength can be increased as compared with, for example, a sheet in which small diameter particles are formed.

  In the above method, it is preferable to use the plastic particles having an average particle size of 100 μm or less.

  In the case of the above method, since a particle layer including plastic particles having an average particle diameter of 100 μm or less is formed, an adsorption-fixing sheet having excellent surface smoothness can be produced. As a result, even if the member to be adsorbed is extremely thin, it is possible to prevent tearing, scratching, and the like from occurring during peeling.

  Further, in the above method, the porous sheet comprises a step of filling an ultra high molecular weight polyethylene powder in a mold and sintering under a predetermined condition to produce a block porous body, and the block porous It is produced by cutting the material into a sheet having a predetermined thickness and producing a porous sheet at least.

  According to the above method, since ultra-high molecular weight polyethylene is used as the material for the porous sheet, a porous sheet having a low friction coefficient and excellent wear resistance and impact resistance can be obtained. Moreover, since ultra high molecular weight polyethylene is inexpensive, the manufacturing cost can be reduced. Moreover, since a porous sheet is prepared by cutting a block-like porous body made of ultrahigh molecular weight polyethylene, a continuous and long adsorbing and fixing sheet can be manufactured. Furthermore, since the thickness at the time of cutting can be changed arbitrarily, it is also possible to manufacture a thick adsorption fixing sheet exceeding 1 mm, for example.

  In order to solve the above-mentioned problems, an adsorption / fixation sheet according to the present invention is an adsorption / fixation sheet obtained by the method for producing an adsorption / fixation sheet described above, and is at least one surface of the porous sheet. In addition, a particle layer including plastic particles is provided, and the particle layer has a surface roughness (Ra) of 0.5 μm or less.

  According to the above configuration, since the particle layer is formed on at least the porous sheet, the strength is excellent. Moreover, since the surface roughness (Ra) of a particle layer is 0.5 micrometer or less, it is excellent in surface smoothness. Further, since the particle layer is a layer including plastic particles, the contact state with the member to be adsorbed is not a surface contact but a multipoint contact. Thereby, the effective contact area of a to-be-adsorbed member and an adsorption | suction surface is reduced, and the peelability of a to-be-adsorbed member and the sheet | seat for adsorption fixation is improved. As a result, even if the member to be adsorbed is extremely thin, it is possible to prevent tearing, scratching, and the like from occurring during peeling.

The present invention has the following effects by the means described above.
That is, according to the method for producing an adsorbing and fixing sheet according to the present invention, the dispersion is directly applied on the porous sheet to form a coating layer, and then the laminate is simply placed on the coating layer. Is obtained. For this reason, compared with the manufacturing method of the conventional sheet | seat for adsorption fixation, a manufacturing line can be simplified and reduction of manufacturing cost can be aimed at. In addition, since the adsorption fixing sheet obtained by the above method forms a particle layer including plastic particles on the porous sheet, it has higher strength, surface smoothness, and peelability than the conventional adsorption fixing sheet. Are better. Furthermore, when ultrahigh molecular weight polyethylene is used as the material for the porous sheet, the porous porous sheet is prepared by cutting the block-shaped porous body made of ultrahigh molecular weight polyethylene. An adsorption fixing sheet can also be manufactured. Furthermore, since the thickness at the time of cutting can be changed arbitrarily, it is also possible to manufacture a thick suction fixing sheet.

  In addition, since the adsorption fixing sheet according to the present invention is excellent in surface smoothness with a surface roughness (Ra) of the particle layer of 0.5 μm or less, even if the adsorbed member is flexible, for example. The surface state of the particle layer is prevented from being transferred to the suction surface of the attracted member. As a result, the product yield can be improved. In addition, since it includes a particle layer including plastic particles, it has excellent releasability, and even when the member to be adsorbed is extremely thin, it can prevent tearing, scratching, and the like during peeling.

  Embodiments of the present invention will be described below with reference to the drawings. However, parts that are not necessary for the description are omitted, and some parts are illustrated by being enlarged or reduced for easy explanation.

  As shown in FIG. 1, the adsorption-fixing sheet obtained by the production method of the present embodiment is used for suction-fixing a member to be adsorbed, and is an adsorption in which a particle layer 13 is provided on a porous sheet 12. It includes at least a fixing sheet 11.

  The method for producing the adsorption and fixing sheet 11 according to the present embodiment includes a step of producing a porous sheet 12, a step of producing a dispersion in which plastic particles are dispersed in a solvent, and the dispersion liquid using the porous sheet 12. A step of directly applying the coating layer to form a coating layer; a step of placing a film on the coating layer; a step of firing the coating layer; and a step of removing the solvent contained in the coating layer. Including. Hereinafter, a case where UHMWPE is used will be described as an example.

  For producing the porous sheet 12 made of UHMWPE, various conventionally known methods can be adopted. Specifically, for example, an extraction method, a sintering method (Japanese Patent Publication No. 5-66855) and the like can be mentioned.

  The sintering method is performed as follows, for example. That is, first, UHMWPE powder (particle size is usually 30 to 200 μm) is filled in a mold, and then this is sintered in a steam atmosphere heated above the melting point of UHMWPE to obtain a block porous body. In this way, the UHMWPE powder is filled in a mold and sintered in a heated steam atmosphere, and therefore, a mold having at least one opening (for heating steam introduction) is used. The time required for sintering varies depending on the amount of powder filling, the temperature of water vapor, and the like, but is usually about 1 to 12 hours.

  Since the water vapor used at this time raises the temperature to the melting point of UHMWPE or higher, it is in a pressurized state, so that it can easily enter between the UHMWPE powders filled in the mold. In order to facilitate the entry of heated water vapor between the UHMWPE powders, the powder was filled in a mold, the mold was placed in a pressure vessel, subjected to a degassing operation to reduce the pressure, and then heated. You may make it sinter in water vapor | steam atmosphere. The degree of decompression at this time is not particularly limited, but is preferably about 0.13 to 13 kPa.

  Therefore, the sintering of the UHMWPE powder filled in the mold is performed by providing a steam inlet pipe and its open / close valve in the pressure vessel, degassing the air between the powders, and stopping the decompression or continuing the decompression. The method can be carried out by opening a steam valve and introducing heated steam.

  During this sintering, the UHMWPE powder is heated to a temperature above its melting point, but its melt viscosity is high, so it does not flow very much, and part or most of the powder shape is maintained. Heat-sealing forms a block-like porous body (non-contact portions between the powders become pores of the porous molded body). In addition, although it can also pressurize if desired in the case of sintering, it is preferable that the pressure shall be about 1 Mpa or less normally.

  After performing the sintering as described above, it is cooled. In cooling, it is preferable to avoid rapid cooling in order to prevent the occurrence of cracks in the block-like porous body. As a cooling method, for example, a method of leaving it at room temperature can be employed. The cooling may be performed while the block-shaped porous body is placed in a mold, or may be performed by removing it from the mold. After cooling the block-like porous body, the block-like porous body is cut to a predetermined thickness using a lathe or the like. Thereby, the porous sheet 12 can be obtained.

  The pore size and porosity of the porous sheet 12 obtained by the above method are determined by the particle size of the UHMWPE powder used and the presence or absence of pressure during sintering. If the other conditions are the same, the larger the particle diameter of the powder used, the larger the pore diameter and the higher the porosity of the porous sheet 12. Further, when no pressure is applied at the time of sintering, a porous sheet 12 having a larger pore diameter and a higher porosity can be obtained than when pressurized. Further, when the pressure is applied during sintering, the porous sheet 12 having a smaller pore diameter and lower porosity can be obtained as the pressure is higher.

  As described above, the UHMWPE porous sheet 12 obtained by such a method has a sheet shape in which the adjacent UHMWPE powder maintains a part or most of the shape thereof and the powders are thermally fused at the contact portion. And has a microstructure with pores in non-contact portions between the powders. The microstructure of the porous sheet is obtained by, for example, cutting the porous sheet 12 along the thickness direction and observing the cut surface with a scanning electron microscope (the magnification is appropriately set, but is usually about 100 to 1000 times). Can be)

  Next, a method for forming the particle layer 13 will be described. First, plastic particles according to the purpose are dispersed in an arbitrary solvent to prepare a dispersion. It does not specifically limit as a solvent, A conventionally well-known thing is employable. However, it is preferable to use a solvent having a boiling point equal to or higher than the temperature at the time of plastic particle sintering described later. From this viewpoint, specific examples include glycerin, ethylene glycol, polyethylene glycol, and the like.

  The mixing ratio of the plastic particles and the solvent is not particularly limited, but the solvent is preferably within the range of about 0.5 to 10 (volume ratio) with respect to the plastic particles 1 and within the range of 1 to 3. Is more preferable.

  In addition, a dispersion aid such as a surfactant or an antifoaming agent can be added to the dispersion. Thereby, it is possible to improve the dispersibility of the plastic particles and to prevent generation of bubbles when the dispersion liquid 14 is applied on a film described later.

  Next, the coating liquid 14 is directly coated on the porous sheet 12 using the coating jig 15 to form the coating layer 14 (see FIG. 2A). Application | coating can be performed by the general method used when applying a viscous material. The thickness of the coating layer 14 may be appropriately set depending on the purpose of use and the size of the plastic particles contained in the dispersion. However, the thickness of the coating layer 14 after sintering is preferably in the range of about 10 to 500 μm, and more preferably in the range of about 20 to 200 μm. If the thickness is smaller than 10 μm, it may be difficult to arrange the plastic particles in the plane. On the other hand, if it is larger than 500 μm, the air permeability may be lowered.

  Next, the film 16 is laminated | stacked on the application layer 14 formed in the porous sheet 12 (refer FIG.2 (b)). As a lamination method, a film may be simply placed on the coating layer 14. Moreover, you may nip by passing between the rolls 17 which become a pair as needed. When the nip is formed, the plastic particles on the surface layer portion (contact portion with the member to be adsorbed) of the particle layer 13 to be formed can be flattened. As a result, when the member to be attracted is fixed by suction, the adhesion with the member to be attracted can be improved.

  The porous sheet 12 may be used as it is, or may be impregnated with a solvent used for the dispersion. Further, the film 16 may be further provided on the back side of the porous sheet 12 (the side opposite to the side in contact with the coating layer). By impregnating the porous sheet 12 with a solvent or providing the film 16 on the back side of the porous sheet 12, evaporation of the solvent during molding can be suppressed.

  The film 16 is preferably one having excellent heat resistance and surface smoothness. In the case of selecting the film 16 from the viewpoint of heat resistance, the film 16 may be appropriately adopted depending on the material of the plastic particles. For example, in the case of UHMWPE or polypropylene particles, the film 16 is preferably polyethylene terephthalate or polyimide. This is because the films 16 made of these materials have sufficient heat resistance, and their surfaces are generally smooth. Further, when the film 16 is selected from the viewpoint of surface smoothness, the smoothness of the flat surface becomes good when the contact portion of the plastic particles with the support is flattened. As a result, when the member to be attracted is fixed by suction, the adhesion with the member to be attracted is improved.

  The surface of the film 16 may be subjected to a hydrophilic treatment in order to increase the affinity with the dispersion. Examples of the hydrophilic treatment method include corona treatment, plasma treatment, and hydrophilic monomer graft treatment.

  Next, it heats to predetermined temperature with the structure which mounted the film 16 on the coating layer 14. FIG. As a result, the contacts between the plastic particles are fused (sintered). As said heating temperature, when using UHMWPE for the material of the porous sheet 12, for example, it is preferably within a range of 130 to 200 ° C, and more preferably within a range of 140 to 180 ° C. Moreover, when using a polypropylene, it is preferable to exist in the range of 150-220 degreeC, and it is more preferable to exist in the range of 170-200 degreeC.

  Cool after sintering. Further, after the film 16 is peeled off, the solvent contained in the coating layer 14 is evaporated at a high temperature. Or the target sheet | seat 11 for adsorption fixation can be manufactured by extracting and drying with another solvent. The adsorbing and fixing sheet 11 obtained by the production method of the present invention is suitable for application to materials and fields that do not require, for example, air permeability and require a certain level of smoothness. In addition, what is necessary is just to select the extraction of a solvent suitably according to the kind of solvent contained in this application layer. In addition, when extracting the solvent, the solvent can be efficiently extracted by applying vibration or applying humidification, for example, by applying ultrasonic waves.

  Next, each component of the adsorption fixing sheet 11 obtained by the above method will be described in detail.

  The porous sheet 12 is a sheet made of, for example, a plastic porous body. The plastic is not particularly limited, and various conventionally known plastics can be employed. Specifically, for example, polyethylene, ultra high molecular weight polyethylene (hereinafter referred to as “UHMWPE”), polypropylene, polystyrene, polyamide, polyester, polyacryl, fluororesin (polytetrafluoroethylene, etc.), butadiene rubber, styrene butadiene rubber, isoprene. Examples thereof include those made of polymer materials such as rubber and nitrile rubber.

  Of these plastics, UHMWPE is preferred in the present invention. This is because the porous sheet 12 made of UHMWPE has a low coefficient of friction, excellent wear resistance and impact resistance, and low cost. Here, the molecular weight of UHMWPE is preferably 500,000 or more, and more preferably 1,000,000 or more from the viewpoint of wear resistance. Specific examples of UHMWPE include commercially available Hi-Zex Million (trade name, manufactured by Mitsui Chemicals), Hostalen GUR (trade name, manufactured by Ticona), and the like. In addition, the said molecular weight says the measured value by ASTMD4020 (viscosity method).

  When the porous sheet 12 is made of UHMWPE, the thickness of the porous sheet 12 can be appropriately set according to the use etc., but is preferably in the range of 0.1 mm to 3.0 mm. . If the thickness is less than 0.1 mm, the mechanical strength of the suction fixing sheet 11 may be reduced and may be broken during use, and workability when attaching the suction fixing sheet 11 to a stacking jig or the like may be reduced. There is. On the other hand, if the thickness is larger than 3.0 mm, the air permeability of the porous sheet 12 is lowered.

  In addition, the porosity of the porous sheet 12 can be appropriately set according to the use and the like when the porous sheet 12 is made of UHMWPE, but is preferably within a range of 10 to 70%. When the porosity is less than 10%, there is a tendency that the air permeability decreases and the friction coefficient increases. On the other hand, when it exceeds 70%, the mechanical strength of the porous sheet 12 decreases. The porosity is calculated from the following formula (1).

  The sheet for adsorbing and fixing 11 according to the present invention may be impregnated with an antistatic agent such as a surfactant or a conductive polymer for the purpose of antistatic. In addition, carbon black or a conductive polymer may be mixed at the time of molding to impart antistatic properties. Moreover, you may impregnate an antistatic agent with the sheet form after cutting. Thereby, for example, spark due to charging of the porous sheet 12 can be avoided in the dicing process of the semiconductor wafer, and damage to the wafer due to the spark can be prevented. Moreover, it is possible to prevent dust and dirt from adhering to a workpiece such as a semiconductor wafer.

  The particle layer 13 is a layer including plastic particles. There are places where adjacent plastic particles are fused (sintered) at the contact portions. The particle layer 13 is on the suction surface side for sucking and fixing a semiconductor wafer or the like.

  The surface roughness (Ra) of the particle layer 13 is preferably 0.5 μm or less, and more preferably in the range of 0.1 to 0.4. When the surface roughness exceeds 0.5 μm, the surface becomes rough, and there is a risk of damaging the member to be adsorbed such as when the member to be adsorbed is extremely thin. On the other hand, when the thickness is less than 0.1 μm, the surface becomes smooth, and the peelability when the attracted member is peeled may be lowered. When the surface roughness (Ra) is 0.5 μm or less, even if the member to be adsorbed is extremely thin and has a small rigidity, such as a green sheet for a multilayer ceramic capacitor, the adsorbed member is adsorbed in the pores of the particle layer 13 It is possible to prevent the member from entering. As a result, it is possible to prevent defects such as irregularities and scratches from occurring in the thin member to be adsorbed, and to improve workability.

  Further, since the particle layer 13 is a layer including plastic particles, when the member to be attracted is fixed by suction, the member to be attracted is not a surface contact but a multipoint contact. Thereby, even if it is excellent in peelability and a to-be-adsorbed member is very thin, it can prevent that a tear, a crack, etc. generate | occur | produce in the case of peeling. In addition, the time required for suction / desorption of the member to be attracted, that is, the cycle time of the manufacturing process can be reduced.

  The constituent material of the plastic particles can be appropriately selected depending on the application. For example, when adopting the manufacturing method described later, it is desirable to be thermoplastic. From the viewpoint of surface roughness and strength, polyethylene, polypropylene and the like are preferable. Furthermore, ultra high molecular weight polyethylene is particularly preferable among the exemplified compounds.

  The average particle size of the plastic particles can be set as appropriate according to the application. However, in order to reduce the surface roughness, it is preferably 100 μm or less, more preferably 30 μm or less. Thereby, the surface smoothness of the adsorption fixing sheet 11 itself can be improved. Therefore, for example, even if the member to be adsorbed has great flexibility, it is possible to prevent the surface state of the particle layer 13 from being transferred to the member to be adsorbed when the member to be adsorbed is sucked and fixed. However, if the average particle size is 1 μm or less, the air permeability may be remarkably lowered or non-porous in the formation of the particle layer 13. Moreover, in order to prevent this non-porous formation, when the particle layer 13 is formed, it is necessary to control the heating temperature, which complicates the process. The average particle diameter of the plastic particles is preferably uniform. This is because the thickness and pore diameter of the particle layer 13 can be made uniform. The average particle diameter is a value measured by a Coulter counter method.

  In addition, the particle shape of the plastic particles can be set as appropriate according to the application. For example, when the particle layer 13 is spherical or substantially spherical, the particle layer 13 has a structure in which plastic particles are arranged in a plane. As a result, the contact area can be reduced, and an adsorption fixing sheet having an extremely small friction coefficient can be obtained. As the particle shape, a potato shape, a grape shape, or the like can be adopted in addition to a spherical shape or a substantially spherical shape. The particle shape of the plastic particles is preferably uniform. This is because the thickness and pore diameter of the particle layer 13 can be made uniform.

  The thickness of the particle layer 13 can be appropriately set according to the application and the like, but is preferably within a range of 10 mm to 500 mm, and more preferably within a range of 20 mm to 200 mm.

  In the case where the adsorbing and fixing sheet 11 according to the present embodiment is peeled after the attracted member is sucked and fixed and conveyed, it is preferable that the adhering and fixing sheet 11 is as excellent in peelability as possible. When this peelability is evaluated by the adhesive strength of a general pressure-sensitive adhesive tape (No. 31, manufactured by Nitto Denko Corporation), the smaller the adhesive strength, the better the peelability. Specifically, the adhesive strength is preferably 2.0 N / 19 mm or less, and more preferably 1.5 N / 19 mm or less. If the adhesive force is greater than 2.0 N / 19 mm, when the dielectric sheet is peeled off, the adsorbed member remains on the surface of the particle layer 13 and there is a possibility that a peeling failure may occur. Moreover, this adhesive force tends to decrease as the surface roughness increases. For this reason, if the adhesive force is too small, the surface roughness is too large, and scratches or the like are generated when the attracted member is sucked and fixed. Therefore, from this point of view, the adhesive strength is preferably 0.3 N / 19 mm or more.

In addition, it is preferable that the suction fixing sheet 11 according to the present embodiment is excellent in air permeability from the problem of takt time for sucking the member to be sucked. Specifically, the air permeability by the Fracigil tester is preferably 0.3 cm ³ / cm ² · sec or more, more preferably 1.0 cm ³ / cm ² · sec or more. When the air permeability is lowered, as described above, the tact time required for adsorbing and fixing the member to be adsorbed becomes long, and the productivity may be lowered.

  The adsorption-fixing sheet according to the present invention may be the adsorption-fixing sheet 11 alone, or may be a laminate in which a plurality of other porous sheets having different hole diameters, strengths, air permeability, and the like are laminated. . In this case, the other porous sheet is laminated on the surface opposite to the adsorption surface (that is, the particle layer 13) of the adsorption fixing sheet 11. When another porous sheet is laminated on the adsorption-fixing sheet 11, it is possible to provide sufficient strength for suction-fixed conveyance as well as good surface smoothness.

  Hereinafter, preferred embodiments of the present invention will be described in detail by way of example. However, the materials, blending amounts, and the like described in the examples are not intended to limit the scope of the present invention only to them, but are merely illustrative examples, unless otherwise specified.

Example 1
UHMWPE powder (molecular weight 5 million, melting point 135 ° C., average particle diameter 180 μm) is filled into a metal mold having an inner diameter of 500 mm and a height of 1000 mm, and this is put into a metal pressure vessel, and the inside of the container reaches about 4 × 10 ³ Pa. The pressure was reduced.

  Thereafter, heated water vapor was introduced, heated at 160 ° C. × 6 atm for 5 hours, and then slowly cooled to produce a cylindrical sintered porous body (block-shaped porous body). This sintered porous body was cut into a sheet by cutting to a thickness of 1.0 mm using a lathe to obtain a porous sheet made of UHMWPE.

  Next, UHMWPE powders having different particle diameters (average molecular weight 2 million, melting point 135 ° C., average particle diameter 30 μm, particle shape: spherical) were mixed with glycerin and a surfactant to prepare a dispersion. The solid content of the dispersion was 40% by volume.

  Subsequently, this dispersion was directly applied onto the porous sheet with a single plate coater using a slit die (lip gap 0.4 mm). The thickness of the coating layer (including the solvent) was 100 μm.

  Immediately after the formation of the coating layer, a polyimide film (Kapton 200H) subjected to corona treatment on the surface was placed. Further, a similar polyimide film was disposed on the back side of the porous sheet.

  This laminate was put into a drier set at 150 ° C. and allowed to stand for 30 minutes. Thereafter, the laminate was taken out and naturally cooled to room temperature. Further, the front and back polyimide films were peeled off and immersed in ethyl alcohol to extract the dispersion solvent. At this time, in order to extract the dispersed solvent efficiently, ultrasonic vibration was applied. Then, ethyl alcohol was volatilized at room temperature, and the sheet for adsorption fixation according to Example 1 was obtained.

(Comparative Example 1)
UHMWPE powder (molecular weight 5 million, melting point 135 ° C., average particle diameter 180 μm) is filled into a metal mold having an inner diameter of 500 mm and a height of 1000 mm, and this is put into a metal pressure vessel, and the inside of the container reaches about 4 × 10 ³ Pa. The pressure was reduced.

  Thereafter, heated water vapor was introduced, heated at 160 ° C. × 6 atm for 5 hours, and then slowly cooled to produce a cylindrical sintered porous body (block-shaped porous body). This sintered porous body was cut into a sheet shape by cutting to a thickness of 1.0 mm using a lathe to obtain a UHMWPE porous sheet as a sheet for adsorption fixation according to Comparative Example 1.

(Various measurements and evaluations)
About each sheet | seat for adsorption fixation produced as mentioned above, surface roughness and air permeability were measured, respectively. The results are shown in Table 1 below. Measurement methods and measurement conditions are as follows.

[Surface roughness]
The surface roughness of the adsorption fixing sheet was measured using a stylus type surface roughness meter (Tokyo Seimitsu Co., Ltd., Surfcom 550A). The measurement conditions were a tip diameter R of 250 μm, a speed of 0.3 mm / sec, and a measurement length of 4 mm.

[thickness]
The thickness of each adsorption fixing sheet was measured using a 1/1000 micrometer.

[Breathable]
The air permeability of each adsorption fixing sheet was measured using a Frazier tester (manufactured by Toyo Seiki Co., Ltd.). The air permeability is a value with respect to the thickness direction of each adsorption fixing sheet.

  As is clear from Table 1, the adsorption-fixing sheet according to Example 1 has a structure in which a particle layer is formed on the porous sheet using a porous sheet made of UHMWPE as a base layer. It was confirmed that Ra) was low and the surface smoothness was excellent. On the other hand, in Comparative Example 1, since the adsorption fixing sheet was only a porous sheet made of UHMWPE, it was confirmed that the surface roughness (Ra) was large and the surface smoothness was inferior.

It is a cross-sectional schematic diagram which shows the outline of the sheet | seat for adsorption fixation which concerns on one Embodiment of this invention. It is a perspective view for demonstrating the manufacturing method of the said sheet | seat for adsorption fixation.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Sheet | seat for adsorption fixation 12 Porous sheet 13 Particle layer 14 Application layer 15 Coating jig 16 Film

Claims (3)

A method for producing a suction fixing sheet that is used for suction fixing of a member to be adsorbed and includes at least a porous sheet,
Producing a dispersion in which plastic particles are dispersed in a solvent;
Applying the dispersion directly on the porous sheet to form a coating layer;
Placing a film on the coating layer;
Baking the coating layer;
And removing the solvent contained in the coating layer to form a particle layer made of the plastic particles. The method for producing a sheet for adsorption and fixation according to claim 1, wherein the plastic particles are those having an average particle diameter of 100 µm or less. The porous sheet is
Filling the mold with ultra high molecular weight polyethylene powder and sintering under predetermined conditions to produce a block-shaped porous body;
It is produced by cutting the block-like porous body into a sheet with a predetermined thickness and producing a porous sheet at least. Sheet manufacturing method.

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