TWI546532B - A method of selecting a separator and an adhesive sheet using the separator selected by the selected method - Google Patents

Description

Method for selecting a separator and an adhesive sheet using the separator selected by the selected method

The present invention relates to a method of selecting a separator and an adhesive sheet using the separator selected by the selected method.

As a method for producing an adhesive sheet having an adhesive layer and a substrate layer, a molding method in which a material constituting a base material layer and a material constituting the adhesive layer are co-extruded due to excellent production efficiency and cost is known (for example, Patent Document 1). Further, the adhesive sheet is usually provided with a separator as a protective material until use in contact with the adhesive layer. In such an adhesive sheet, when the adhesive sheet is formed by co-extrusion, foreign matter is prevented from being mixed between the adhesive layer and the separator, and the surface where the adhesive layer is in contact with the separator is smooth. The sheet is adhered, and therefore, a method of bonding the coextruded adhesive layer forming material to the separator in a molten state is studied. However, in many cases, the adhesive sheet obtained in this manner is difficult to peel off the separator, and the sheet is rationally lowered. Moreover, when the separator which is lightly peeled is used, the handleability improves, but in many cases, the adhesive force of the adhesive layer at the time of storage of the adhesive sheet is reduced. In this way, it is difficult to achieve the good and rational adhesion of the adhesive sheet at the same time.

The separator used in the adhesive sheet is appropriately selected according to the kind of the release agent, its peeling force, and the like. However, as described above, in the case of bonding with the molten adhesive layer forming material, there is a case where the original ability of the separator in the obtained adhesive sheet is not exerted. Therefore, the separator used in the adhesive sheet produced by melt co-extrusion must first be selected. Select the replacement piece and study the fit of the piece after actually making the adhesive sheet. Therefore, each time the structure of the adhesive sheet is changed, it is necessary to prepare an adhesive sheet and study the suitability of the separator. Therefore, it is not easy to select an appropriate separator.

Prior technical literature Patent literature

Patent Document 1: Japanese Patent Laid-Open Publication No. 2009-275209

The present invention has been made to solve the above problems, and an object of the invention is to provide a method for easily selecting a separator suitable for an adhesive sheet having at least an adhesive layer.

The method for selecting a separator of the present invention comprises the steps of: bonding at least a material forming an adhesive layer to a separator in a molten state to obtain an adhesive sheet having at least an adhesive layer and a separator; and self-obtaining adhesive sheets The separator is peeled off, and the adhesive sheet of the adhesive sheet is bonded to the evaluation separator to form a pressure-sensitive adhesive sheet for evaluation; and the evaluation adhesive is sandwiched between the pair of cushioning materials and the pair of pressure plates. The sheet was subjected to a step of evaluating the peeling force of the separator for separation by a 180° peel test at a peeling speed of 300 mm/min after the sheet temperature was maintained at 140 ° C and a pressure of 5 MPa for 1 minute.

In a preferred embodiment, the separator having a peeling force measured in the above evaluation step of 2.0 N/50 mm or less is selected.

In a preferred embodiment, the adhesive layer of the adhesive sheet comprises a polyolefin resin.

In a preferred embodiment, the polyolefin-based resin comprises an amorphous propylene-(1-butene) copolymer polymerized using a metallocene catalyst.

In another embodiment of the invention, an adhesive sheet is provided. The adhesive sheet comprises a substrate layer, an adhesive layer, and a separator selected by the above selected method.

According to the present invention, the separator suitable for the adhesive sheet can be easily selected.

The method of selecting the separator of the present invention is a method of selecting a separator suitable for adhering the sheet. According to the method of the present invention, it is possible to easily select a separator suitable for an adhesive sheet obtained by laminating at least a material forming an adhesive layer with a separator in a molten state. The method for selecting a separator of the present invention comprises the steps of: bonding at least a material forming an adhesive layer to a separator in a molten state to obtain an adhesive sheet having at least an adhesive layer and a separator; and self-obtaining adhesive sheets The separator is peeled off, and the adhesive sheet of the adhesive sheet is bonded to the evaluation separator to form a pressure-sensitive adhesive sheet for evaluation; and the evaluation adhesive is sandwiched between a pair of cushioning materials and a pair of pressure plates. The sheet was subjected to a step of evaluating the peeling force of the separator for evaluation by a 180° peeling test at a peeling speed of 300 mm/min after the sheet temperature was maintained at 140 ° C and a pressure of 5 MPa for 1 minute. According to the selected method of the present invention, the separator suitable for the adhesive sheet can be easily selected by evaluating the peeling force of the separator.

A. Step of obtaining an adhesive sheet having at least an adhesive layer and a separator

The selected method of the present invention comprises the step of bonding at least a material forming the adhesive layer to the separator in a molten state to obtain an adhesive sheet having at least an adhesive layer and a separator. The adhesive sheet typically has a substrate layer, an adhesive layer, and a separator in sequence.

The method for forming the above-mentioned adhesive sheet is not particularly limited, and may include a step of bonding at least a material forming the pressure-sensitive adhesive layer to the separator in a molten state. The above-mentioned forming method includes, for example, a step of extruding a material forming the adhesive layer and a material forming the substrate layer after melting to obtain a laminate of the adhesive layer and the substrate layer, and a material for forming at least the adhesive layer The step of bonding the adhesive layer of the laminate to the separator in a molten state to obtain an adhesive sheet.

In the step of obtaining the laminate of the adhesive layer and the substrate layer, the laminate may be supplied with a material forming an adhesive layer, for example, by one of at least two extruders attached to the mold. The stage is supplied with a material forming the substrate layer, and is obtained by extrusion after melting. The conditions (for example, the mold temperature) at the time of molding the above-mentioned adhesive sheet can be appropriately set depending on the materials constituting the respective layers of the adhesive sheet. For example, the mold temperature can be set to a temperature at which the material forming the layers of the adhesive sheet becomes a molten state. In one embodiment, the mold temperature can be set to 160 ° C to 220 ° C.

Specifically, the step of bonding the laminate to the separator may be carried out by: in the step of obtaining the laminate, at least the material of the adhesive layer forming the extruded laminate is melted In this state, the adhesive layer of the laminate is brought into contact with the separator, and the contact roll forming method is used. Line pull. The conditions (for example, the temperature at which the material constituting the adhesive layer is brought into contact with the separator and the contact pressure) when the material forming the pressure-sensitive adhesive layer is brought into contact with the separator can be appropriately set depending on the material constituting each layer of the pressure-sensitive adhesive sheet. For example, the temperature at which the material constituting the adhesive layer is brought into contact with the separator may be set to a temperature at which at least the state in which the material forming the adhesive layer is melted is maintained. In one embodiment, the temperature at which the material constituting the adhesive layer is brought into contact with the separator may be set to 120 ° C to 200 ° C.

As the separator used in this step (hereinafter also referred to as a separator for production), any appropriate separator can be used. For example, in the technical field, a general separator can be used as a separator for an adhesive sheet. Specific examples include MRF-38 manufactured by Mitsubishi Plastics Co., Ltd., and HY-S06 manufactured by Higashiyama Film Co., Ltd., and the like.

B. Steps for making an adhesive sheet for evaluation

The evaluation adhesive sheet used in the evaluation step in the selected method of the present invention is obtained in the following manner. First, the adhesive sheet is peeled off from the adhesive sheet obtained by the method of the above item A. The peeling of the separator can be carried out by any appropriate mechanism, and peeling can be carried out using any appropriate peeling machine, or peeling can be carried out by hand.

Then, the adhesive layer from which the adhesive sheet of the separator was peeled off was bonded to the evaluation separator which was selected as the object to be selected. Since the pressurization is performed in the evaluation step of the peeling force described below, it is not necessary to firmly bond the adhesive sheet to the evaluation separator in the step of producing the adhesive sheet for evaluation, and the adhesive sheet is bonded to the adhesive sheet. The degree of the laminated state with the separator for evaluation may be sufficient.

C. Evaluation procedure for peeling force of the separator for evaluation

The peeling force evaluation step of the above-mentioned evaluation separator sheet was carried out as follows. The evaluation adhesive sheet obtained in the above step B was sandwiched between a pair of cushioning materials, and further sandwiched between a pair of pressure plates, and held at a pressure plate surface temperature of 140 ° C and a pressure of 5 MPa for 1 minute. Pressure. In the separator used for the adhesive sheet, if the temperature of the pressure plate surface exceeds 140 ° C, the peeling of the separator sheet and the pressure-sensitive adhesive layer tends to be difficult. Therefore, the pressure of the pressure-sensitive adhesive sheet for evaluation can be increased by setting the temperature of the pressure plate surface to 140 ° C, and the peeling force of the evaluation separator sheet in the pressure-sensitive adhesive sheet after pressurization can be evaluated and selected. The separator is used as a separator for the adhesive sheet. Further, the pressure plate surface temperature in the peeling force evaluation test of the present invention means the temperature of the surface of the pressure plate.

In the above pressurization, a cushioning material is disposed between the evaluation adhesive sheet and the pressure plate in order to prevent excessive pressure from being applied to the adhesive sheet. As the cushioning material, any appropriate cushioning material which can be used for hot pressing can be used. Examples of the cushioning material include a rubber, a heat-resistant elastic body, a combination of an organic or inorganic fiber with a binder, a non-woven fabric, a laminate of a rubber and a non-woven fabric, and the like. The cushioning material used for pressurization may be selected from a suitable cushioning material which allows the pressure applied to the pressure-sensitive adhesive sheet for evaluation to be an appropriate pressure. For example, the pressure applied to the evaluation adhesive sheet can be adjusted by adjusting the constituent material and size (area) of the cushioning material. More specifically, for a separator having a size of 150 mm × 200 mm, a rubber sheet having an area of 130 mm × 160 mm can be used.

Moreover, in order to prevent sticking of the cushioning material and the adhesive sheet for evaluation at the time of pressurization Further, a resin sheet may be placed between the cushioning material and the pressure-sensitive adhesive sheet for evaluation, and pressurized. The resin sheet may be any resin sheet that can be used as a separator, and any suitable sheet may be used. For example, a polyethylene terephthalate resin sheet or a polyimide film may be used. . The thickness of the resin sheet is usually from 38 μm to 75 μm.

The pressurization of the pressure-sensitive adhesive sheet for evaluation can be carried out by any appropriate mechanism capable of setting the temperature and pressure of the pressure plate surface. For example, it can be carried out using a commercially available press machine, and specifically, MINI TEST PRESS-10 manufactured by Toyo Seiki Co., Ltd., and the like can be mentioned.

The adhesive sheet for evaluation after pressurization was left to room temperature, and the peeling test of the separator for evaluation was performed. This peeling test was performed by peeling the evaluation separator sheet at a peeling speed of 300 mm/min and a peeling angle of 180°.

The desired separator can be selected according to the peeling force measured by the above peeling test and depending on the characteristics required for the separator. For example, in the case of a separator which is excellent in handleability and maintains an appropriate adhesive strength, a separator having a peeling force measured in the above peeling test of 2.0 N/50 mm or less can be preferably used. Further, in the case where a separator having a higher adhesiveness between the adhesive layer and the separator is required, the separator having a peeling force measured in the above peeling test exceeding 2.0 N/50 mm may be used. In terms of handling in a commercially available tape attaching device (for example, a protective tape attaching device for back grinding manufactured by Nitto Seiki Co., Ltd., trade name DR3000III, etc.), the peeling force measured in the above peeling test is 2.0 N/ With a 50 mm reference, you can choose the separator you want. Furthermore, in the case of a separator which requires a higher degree of handling, the above peeling is used. The separator having a smaller peeling force measured in the test may be used.

D. Adhesive sheet

The adhesive sheet used in the present invention typically comprises a substrate layer, an adhesive layer and a separator. Further, the adhesive sheet may optionally contain any other suitable layer. As the other layer, for example, a surface layer to which heat resistance is imparted can be mentioned.

The thickness of the adhesive sheet (excluding the thickness of the separator) is preferably from 90 μm to 285 μm, more preferably from 105 μm to 225 μm, and still more preferably from 130 μm to 210 μm.

D-1. Separator

The separator is selected by the method of selecting the separator of the present invention. The separator usually has a substrate layer and a release agent layer. The base material layer and the release agent layer may be formed of any suitable material. Preferably, the separator has a peeling force of 2.0 N/50 mm or less, more preferably 0.05 N/50 mm to 2.0 N/50 mm, and still more preferably 0.05 N, which is evaluated in the selected method of the present invention. /50 mm~1.8 N/50 mm. By using such a separator, an adhesive sheet having excellent practicability and maintaining a moderate adhesive force is obtained. Further, in the case of forming an adhesive sheet in which the separator is less likely to be peeled off from the adhesive layer, the separator having an evaluation peeling force exceeding 2.0 N/50 mm in the selected method of the present invention may be used.

The thickness of the separator is not particularly limited and can be set to any appropriate thickness. The thickness of the separator can be set, for example, from 25 μm to 250 μm.

D-2. Adhesive layer

The above adhesive layer is formed by any suitable adhesive, for example An adhesive containing a thermoplastic resin such as a polyolefin resin, an acrylic resin or a styrene resin is used. The pressure-sensitive adhesive layer preferably contains a polyolefin-based resin, and specific examples thereof include low-density polyethylene, ultra-low-density polyethylene, low-crystalline polypropylene, and amorphous propylene-(1-butene) copolymer. Ethylene polymer resin, ethylene-vinyl acetate copolymer, ethylene-(meth)acrylic acid copolymer, ethylene-(meth)acrylate-maleic anhydride copolymer, ethylene-glycidyl methacrylate copolymer, etc. Copolymer or polyolefin modified polymer, and the like. The adhesive layer more preferably contains an amorphous propylene-(1-butene) copolymer. By using such an adhesive layer, it is possible to obtain an adhesive sheet which is less contaminated by the adherend, achieves adhesiveness and peelability, and can be produced by co-extrusion molding. Further, in the case of such an adhesive layer, an adhesive sheet can be produced by co-extrusion with a base material layer, and an adhesive sheet can be obtained with a small number of steps and without using an organic solvent. In the present specification, "amorphous" means a property which does not have a melting point as defined by crystallinity.

The above amorphous propylene-(1-butene) copolymer is preferably obtained by polymerizing propylene and 1-butene using a metallocene catalyst. More specifically, the amorphous propylene-(1-butene) copolymer can be subjected to, for example, a polymerization step of polymerizing propylene and 1-butene using a metallocene catalyst and performing residual catalyst removal after the polymerization step. Obtained by a post-treatment step such as a step, a foreign matter removal step, and the like. The amorphous propylene-(1-butene) copolymer is obtained in such a form as a powder, a pellet or the like through such a step. Examples of the metallocene catalyst include a metallocene supported catalyst containing a metallocene compound and a metallocene uniformly mixed catalyst, and a metallocene compound supported on a fine particle carrier. Amorphous propylene-(1-butene) copolymer polymerized using metallocene catalyst shows narrow Narrow molecular weight distribution.

The content ratio of the constituent unit derived from propylene in the amorphous propylene-(1-butene) copolymer is preferably from 80 mol% to 99 mol%, more preferably from 85 mol% to 99 mol%, and further It is preferably 90% by mole to 99% by mole.

The content ratio of the constituent unit derived from 1-butene in the amorphous propylene-(1-butene) copolymer is preferably from 1 mol% to 15 mol%, more preferably from 1 mol% to 10 mol%. %. When it is such a range, an adhesive sheet excellent in the balance of toughness and flexibility can be obtained.

The above amorphous propylene-(1-butene) copolymer may be a block copolymer or a random copolymer.

The amorphous propylene-(1-butene) copolymer may further contain constituent units derived from other monomers within the range which does not impair the effects of the present invention. Examples of the other monomer include ethylene, 1-pentene, 1-hexene, 1-octene, 1-decene, 4-methyl-1-pentene, and 3-methyl-1-pentene. Such as α-olefins and the like.

The above-mentioned adhesive layer may further contain other components within the range which does not impair the effects of the present invention. Examples of the other component include an antioxidant, an ultraviolet absorber, a light stabilizer, a heat stabilizer, and an antistatic agent. The type and amount of other components can be appropriately selected depending on the purpose.

The thickness of the adhesive layer is preferably from 20 μm to 100 μm, more preferably from 30 μm to 65 μm.

D-3. Substrate layer

The base material layer may be formed using any appropriate material, and examples thereof include polyester (polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, and polynaphthalene dicarboxylic acid). Butadiene ester, etc., polyolefin (polyethyl b Alkene, polypropylene, ethylene-propylene copolymer, etc.), polyvinyl alcohol, polydivinylidene chloride, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, ethylene-vinyl acetate copolymer, polyvinyl acetate, poly Amidoxime, polyimine, cellulose, fluorine resin, polyether, polystyrene resin (polystyrene, etc.), polycarbonate, polyether oxime or the like. Preferably, the substrate layer comprises an ethylene-vinyl acetate copolymer.

The base material layer may further contain other components within the range which does not impair the effects of the present invention. As the other component, for example, the same components as those other components which can be contained in the above-mentioned adhesive layer can be used.

The thickness of the substrate layer is preferably from 30 μm to 185 μm, more preferably from 65 μm to 175 μm.

D-4. Other layers

Examples of the other layer included in the adhesive sheet of the present invention include a surface layer which can impart heat resistance to the adhesive sheet. As the surface layer, any suitable resin having heat resistance can be used, and a polypropylene resin is preferable. The above polypropylene-based resin is preferably obtained by polymerization using a metallocene catalyst. More specifically, the polypropylene-based resin can be subjected to, for example, a polymerization step of polymerizing a monomer composition containing propylene using a metallocene catalyst, and a post-treatment such as a residual catalyst removal step or a foreign matter removal step after the polymerization step. Obtained by the steps. The polypropylene resin is obtained in such a form as a powder or a pellet by such a procedure. As the metallocene catalyst, for example, those exemplified above can be cited.

Commercially available products can also be used as the polypropylene resin. Specific examples of the polypropylene-based resin which is commercially available include Japan Polypropylene Co., Ltd. The company's trade names are "WINTEC" and "WELNEX" series.

The above surface layer may further contain other components within the range which does not impair the effects of the present invention. The other component may be the same as the other components which may be included in the adhesive layer described above. The type and amount of other components can be appropriately selected depending on the purpose.

Example

Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited by the examples. Furthermore, the test and evaluation methods in the examples and the like are as follows. Also, parts mean parts by weight.

(Reference Example 1) Production of adhesive sheets for testing

As a material for forming a surface layer capable of imparting heat resistance, a polypropylene resin polymerized by a metallocene catalyst (manufactured by Japan Polypropylene Co., Ltd., trade name "WELNEX: RFGV4A"; melting point 130 ° C, softening point 120 ° C, Mw is used. /Mn = 2.9).

As a material for forming the base material layer, an ethylene-vinyl acetate copolymer (manufactured by Mitsui Dupont Co., Ltd., trade name "EVAFLEX P-1007") was used.

As a material for forming the adhesive layer, an amorphous propylene-(1-butene) copolymer polymerized by a metallocene catalyst (manufactured by Sumitomo Chemical Co., Ltd., trade name "TAFTHREN H5002": constituent unit derived from propylene 90 is used. Molar % / constituent unit from 1-butene 10 mol%, Mw = 230,000, Mw / Mn = 1.8).

100 parts of the material for forming the surface layer, 100 parts of the material for forming the substrate layer, and 100 parts of the material for forming the adhesive layer were put into respective extruders, and T-die melt co-extrusion was carried out (mold temperature: 180 ° C). By The contact roll was bonded to a manufacturing separator (Mitsubishi Resin, MRF38, thickness 38 μm) (air gap: 150 mm, contact temperature: 165 ° C) on the surface layer/substrate layer/adhesive co-extruded from the mold. The adhesive layer of the laminate of the agent layer was obtained to obtain a test adhesive sheet of a surface layer (thickness: 30 μm) / a substrate layer (thickness: 130 μm) / an adhesive layer (thickness: 45 μm) / separator. Furthermore, the thickness of the surface layer, the substrate layer and the adhesive layer is controlled by the shape of the T-die exit.

[Example 1] Selection of a separator suitable for an adhesive sheet (evaluation separator 1)

The adhesive sheet obtained in Reference Example 1 peeled off the separator on the side of the adhesive layer. Then, the separator 1 for evaluation (HY-S30, manufactured by Higashiyama Film Co., Ltd., thickness: 38 μm) was bonded to the pressure-sensitive adhesive layer to obtain an adhesive sheet for evaluation.

The evaluation adhesive sheet obtained was pressed using a press machine (manufactured by Toyo Seiki Co., Ltd., MINI TEST PRESS-10, panel area: 250 mm × 250 mm). MRN38 made of Mitsubishi resin was used as a resin sheet (separator), and a rubber sheet (thickness: 1 mm, 130 mm × 160 mm) was used as a cushioning material. Adhesive sheet for evaluation is laminated with stainless steel plate (SUS (Steel Use Stainless) plate) / resin sheet / cushioning material / resin sheet / evaluation adhesive sheet / resin sheet / cushioning material / After the resin sheet/stainless steel plate, it was sandwiched by a pressurizing plate, and held at a press plate surface temperature of 140 ° C and a pressurizing pressure of 5 MPa for 1 minute. Then, the adhesive sheet was allowed to stand at room temperature, and the peeling force of the evaluation sheet for the adhesive sheet (peeling speed: 300 mm/min, peeling angle: 180°) was measured. Peeling The force is shown in Table 1.

(evaluation separator 2)

The peeling force of the evaluation separator sheet was measured in the same manner as the evaluation separator sheet 1 except that the evaluation separator sheet 2 (Higashiyama Film Co., Ltd., HY-TS11, thickness: 75 μm) was used instead of the evaluation separator sheet 1. The measured peeling force is shown in Table 1.

(evaluation separator 3)

The peeling force of the evaluation separator sheet was measured in the same manner as the evaluation separator sheet 1 except that the separator sheet for evaluation 3 (HY-TS15, thickness: 75 μm, manufactured by Higashiyama Film Co., Ltd.) was used instead of the separator sheet 1 for evaluation. The measured peeling force is shown in Table 1.

(evaluation separator 4)

The peeling force of the evaluation separator sheet was measured in the same manner as the evaluation separator sheet 1 except that the evaluation separator sheet 4 (manufactured by Mitsubishi Plastics Co., Ltd., MRE 38, thickness: 38 μm) was used instead of the evaluation separator sheet 1. The measured peeling force is shown in Table 1.

(evaluation separator 5)

The peeling force of the evaluation separator sheet was measured in the same manner as the evaluation separator sheet 1 except that the separator sheet for evaluation 5 (manufactured by Mitsubishi Plastics Co., Ltd., MRN 38, thickness: 38 μm) was used instead of the separator sheet 1 for evaluation. The measured peeling force is shown in Table 1.

(evaluation separator 6)

The peeling force of the evaluation separator sheet was measured in the same manner as the evaluation separator sheet 1 except that the evaluation separator sheet 6 (MRF38, thickness: 38 μm, manufactured by Mitsubishi Plastics Co., Ltd.) was used instead of the evaluation separator sheet 1. The measured peeling force is shown in Table 1.

(evaluation separator 7)

The peeling force of the evaluation separator sheet was measured in the same manner as the evaluation separator sheet 1 except that the separator sheet for evaluation 7 (HY-S10, thickness: 75 μm, manufactured by Higashiyama Film Co., Ltd.) was used instead of the separator sheet 1 for evaluation. The measured peeling force is shown in Table 1.

(evaluation separator 8)

The peeling force of the evaluation separator sheet was measured in the same manner as the evaluation separator sheet 1 except that the separator sheet for evaluation 8 (HY-S06, thickness: 75 μm, manufactured by Higashiyama Film Co., Ltd.) was used instead of the separator sheet 1 for evaluation. The measured peeling force is shown in Table 1.

(evaluation separator 9)

The peeling force of the evaluation separator sheet was measured in the same manner as the evaluation separator sheet 1 except that the separator sheet for evaluation 9 (HY-TS05G, thickness: 75 μm, manufactured by Higashiyama Film Co., Ltd.) was used instead of the separator sheet 1 for evaluation. The measured peeling force is shown in Table 1.

(evaluation separator 10)

The peeling force of the evaluation separator sheet was measured in the same manner as the evaluation separator sheet 1 except that the evaluation separator sheet 10 (Higashiyama Film Co., Ltd., HY-US20, thickness: 75 μm) was used instead of the evaluation separator sheet 1. The measured peeling force is shown in Table 1.

[Example 2] Evaluation of an adhesive sheet using a selected separator

Adhesive sheets 1 to 10 were obtained in the same manner as in Reference Example 1 except that the evaluation separators 1 to 10 were used. The obtained adhesive sheets 1 to 10 were used in the following evaluations. The results are shown in Table 2.

[Evaluation] (1) Peel force of the separator

The peeling force of the separator in the obtained adhesive sheet was measured (peeling speed: 300 mm/min, peeling angle: 180°).

(2) Adhesion of the adhesive layer

After the obtained adhesive sheet was aged at 50 ° C for 2 days, the separator attached to the adhesive layer was peeled off by a method in accordance with JIS Z 0237 (2000) (adhesion conditions: 2 kg roller reciprocating once, peeling off Speed: 300 mm/min, peeling angle 180°) The adhesion of the adhesive layer to the mirror surface of a 4 Å semiconductor wafer was measured. When the measured value is 0.005 N/20 mm or more, it has sufficient adhesion as an adhesive sheet.

In the adhesive sheets 1 to 5 of the separators 1 to 5 having a peeling force of 2.0 N/50 mm or less in the separator measured in Example 1, the peeling of the separator was easy and the adhesion of the pressure-sensitive adhesive layer was moderately maintained. Further, the measurement was carried out in Example 1. In the adhesive sheets 6 to 10 of the separators 6 to 10 in which the peeling force of the separator exceeds 2.0 N/50 mm, the force required for peeling off the separator is larger than that of the separators 1 to 5.

Industrial availability

The method of selecting the separator of the present invention can be preferably used, for example, for the selection of the separator used in the adhesive sheet.

Claims (4)

A method for selecting a separator, comprising: laminating at least a material forming an adhesive layer with a separator in a molten state to obtain an adhesive sheet having at least an adhesive layer and a separator; and self-adhesive bonding The sheet is peeled off from the separator, and the adhesive sheet of the adhesive sheet is bonded to the evaluation separator to form a pressure-sensitive adhesive sheet for evaluation; and the evaluation is performed by a pair of cushioning materials and a pair of pressure plates. After the adhesive sheet was held at a pressure plate surface temperature of 140 ° C and a pressure of 5 MPa for 1 minute, the peeling force of the evaluation separator sheet was evaluated by a 180° peel test at a peeling speed of 300 mm/min. The method for selecting a separator according to claim 1 is a separator selected from the above-mentioned evaluation step and having a peeling force of 2.0 N/50 mm or less. A method of selecting a separator according to claim 1, wherein the adhesive layer of the adhesive sheet comprises a polyolefin resin. A method of selecting a separator according to claim 3, wherein the polyolefin-based resin comprises an amorphous propylene-(1-butene) copolymer polymerized using a metallocene catalyst.