JP2013144788A - Temporary fixing material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a temporary fixing material which does not break even after repeated use and which can maintain adhesiveness and detachability at a high level.SOLUTION: A temporary fixing material contains a foam having a continuous bubble structure having through-holes between adjacent spherical bubbles, wherein an average diameter of the spherical bubbles is less than 20 μm, an average diameter of the through-holes is 5 μm or less, surface openings having an average diameter of 20 μm or less are provided on the surface, and normal shear bond force is 1 N/cmor greater.

Description

  The present invention relates to a temporary fixing material.

  In general, a pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer is used for temporarily fixing a post such as an advertisement or a calendar to a wall or window glass.

  In recent years, a temporary fixing sheet in which an acrylic foam layer is provided on both surfaces of a base material has been proposed (Patent Document 1). Since the temporary fixing sheet does not have an adhesive layer, there is an advantage that it can be easily peeled off and the problem of adhesive residue does not occur. However, when the thickness of the acrylic foam layer constituting the temporary fixing sheet is 0.3 mm or less, the mechanical strength may be insufficient and may break at the time of desorption. Therefore, there is a need for further development of a temporary fixing material that can maintain adhesiveness and peelability at a high level without breaking even when used repeatedly. Further, the temporary fixing sheet contains a foaming aid and a foam stabilizer in the acrylic foam layer, and these are bleed over time, and there is a concern about contamination of the adherend.

JP 2010-234536 A

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a temporary fixing material that can maintain adhesiveness and peelability at a high level without breaking even when repeatedly used. That is.

According to the present invention, a temporary fixing material is provided. The temporary fixing material is a temporary fixing material including a foam having an open cell structure having through-holes between adjacent spherical bubbles, and the average pore diameter of the spherical bubbles is less than 20 μm, and the average pore diameter of the through-holes Is 5 μm or less, has a surface opening with an average pore diameter of 20 μm or less on the surface, and has a normal shear adhesive strength of 1 N / cm ² or more.
In a preferred embodiment, the temporarily fixed material has a 180 ° peel test force of 1 N / 25 mm or less.
In a preferred embodiment, the 60 ° C. holding force of the temporary fixing material is 0.5 mm or less.
In a preferred embodiment, the dimensional change rate when the temporary fixing material is stored at 125 ° C. for 22 hours is less than ± 5%.
In a preferred embodiment, the temporary fixing material is stored at 80 ° C. for 22 hours in a 50% compression state, then cooled to 23 ° C., and then, after 30 minutes have passed after the compression state is released, 50% compression strain recovery is achieved. The rate is 70% or more.
In a preferred embodiment, the foam has a density in the ^{0.15g / cm 3 ~0.6g / cm 3} .
In a preferred embodiment, the foam ratio of the foam is 30% or more.

  ADVANTAGE OF THE INVENTION According to this invention, even if it uses repeatedly, the temporary fixing material which can maintain adhesiveness and peelability at a high level without fracture | rupture can be provided. The temporary fixing material of the present invention is practical even if the total thickness is 0.5 mm or less, for example.

It is a schematic sectional drawing of the temporary fixing material by preferable embodiment of this invention. It is a schematic sectional drawing of the temporary fixing material by another preferable embodiment of this invention. It is a schematic sectional drawing of the temporary fixing material by another preferable embodiment of this invention. It is a schematic sectional drawing of the temporary fixing material by another preferable embodiment of this invention. It is a photographic view of a cross-sectional SEM photograph of a foam, and is a photographic view clearly showing an open cell structure having through holes between adjacent spherical bubbles. It is a photograph figure of the surface / cross-section SEM photograph which image | photographed the temporarily fixing sheet produced in Example 1 from diagonally. It is explanatory drawing explaining the measuring method of a 50% compression-strain recovery rate.

≪A. Temporary fixing material >>
The temporarily fixing material of this invention contains the foam which has a predetermined structure, and may further contain an adhesive layer as needed. FIG. 1A is a schematic cross-sectional view of a temporary fixing material according to a preferred embodiment of the present invention. The temporary fixing material 100a includes a foam 10 having a predetermined structure. FIG. 1B is a schematic cross-sectional view of a temporary fixing material according to another preferred embodiment of the present invention. The temporary fixing material 100b includes a first foam 10a having a predetermined structure, a base material 20, and a second foam 10b having a predetermined structure in this order. FIG. 2A is a schematic cross-sectional view of a temporary fixing member according to still another preferred embodiment of the present invention. The temporary fixing material 100c includes a foam 10 having a predetermined structure and an adhesive layer 40 disposed on one surface thereof. The pressure-sensitive adhesive layer 40 is composed of a first pressure-sensitive adhesive layer 40a, a second pressure-sensitive adhesive layer 40b, and a support body 41 disposed therebetween. FIG. 2B is a schematic cross-sectional view of a temporary fixing material according to still another preferred embodiment of the present invention. The temporary fixing material 100d includes a first foam 10a having a predetermined structure, a base member 20, a second foam 10b having a predetermined structure, and an adhesive layer 40 in this order. In FIG. 1A, FIG. 1B, FIG. 2A and FIG. 2B, a release film 30 is provided to protect the adhesive surface (foam surface or adhesive layer surface) of the temporary fixing material. May not be provided. According to the temporary fixing material 100a or 100b, since the foam itself has adhesive strength, the article is temporarily fixed at a desired place without using an adhesive layer (that is, without causing a problem of adhesive residue). Can do. In addition, with one surface of the temporary fixing material 100a or 100b fixed to a desired location via any appropriate pressure-sensitive adhesive layer, the product is temporarily fixed on the other surface to bring the product to a desired location. It can be temporarily fixed. On the other hand, according to the temporary fixing material 100c or 100d, the temporary fixing material can be firmly fixed to a desired place by one pressure-sensitive adhesive layer surface, and the article can be temporarily fixed by the other foam surface without a problem of adhesive residue. .

  The temporary fixing material of the present invention has a surface opening on the surface. The average pore diameter of the surface opening is 20 μm or less, preferably less than 20 μm, more preferably 15 μm or less, further preferably 10 μm or less, further preferably 5 μm or less, and particularly preferably 4 μm or less. And most preferably 3 μm or less. The lower limit of the average pore diameter of the surface opening is not particularly limited, and is preferably 0.001 μm, and more preferably 0.01 μm, for example. When the temporary fixing material of the present invention has a surface opening and the average pore diameter of the surface opening is within the above range, the surface opening plays a role of a micro suction cup and expresses sufficient adhesive force. A temporary fixing material can be provided, and a temporary fixing material having high flexibility and high heat resistance can be provided.

The temporary fixing material of the present invention has a normal shear adhesive strength of 1 N / cm ² or more, preferably 3 N / cm ² or more, more preferably 5 N / cm ² or more, and further preferably 7 N / cm ^2. Or more, particularly preferably 9 N / cm ² or more, and most preferably 10 N / cm ² or more. When the normal shear adhesive force of the temporary fixing material of the present invention falls within the above range, the temporary fixing material of the present invention can exhibit sufficient adhesive force.

  The temporary fixing material of the present invention has a 180 ° peel test force (for example, a 180 ° peel test force on the foam surface) of preferably 1 N / 25 mm or less, more preferably 0.8 N / 25 mm or less, and still more preferably. Is 0.5 N / 25 mm or less, particularly preferably 0.3 N / 25 mm or less. When the 180 ° peel test force of the temporary fixing material of the present invention falls within the above range, the temporary fixing material of the present invention can be easily peeled despite the high adhesive strength as described above. An excellent effect can be exhibited.

  The temporary fixing material of the present invention has a 60 ° C. holding force (for example, 60 ° C. holding force of the foam surface), preferably 0.5 mm or less, more preferably 0.4 mm or less, and still more preferably 0.3 mm. Or less, particularly preferably 0.2 mm or less. When the 60 ° C. holding force of the temporarily fixing material of the present invention falls within the above range, the temporarily fixing material of the present invention can achieve both excellent heat resistance and sufficient adhesive force.

  The temporary fixing material of the present invention has a dimensional change rate when stored at 125 ° C. for 22 hours, preferably less than ± 5%, more preferably ± 3% or less, and further preferably ± 1% or less. . In the temporary fixing material of the present invention, the dimensional change rate when stored at 125 ° C. for 22 hours is within the above range, whereby the temporary fixing material of the present invention can have excellent heat resistance.

  The temporary fixing material of the present invention is stored at 80 ° C. for 22 hours in a 50% compressed state, then cooled to 23 ° C., and then, when 30 minutes have elapsed after the compression state is released, the 50% compression strain recovery rate is Preferably it is 70% or more, More preferably, it is 75% or more, More preferably, it is 80% or more, Most preferably, it is 85% or more. The upper limit of the 50% compression strain recovery rate is preferably 100%. When the 50% compression strain recovery rate of the temporary fixing material of the present invention falls within the above range, the temporary fixing material of the present invention can exhibit excellent compressive strain recovery properties. A specific method for measuring the 50% compression strain recovery rate is as described in the examples described later.

  The temporary fixing material of the present invention can take any appropriate shape. Practically, preferably, the temporary fixing material of the present invention is a sheet-like temporary fixing sheet. When the temporarily fixed material of the present invention is a temporarily fixed sheet, the thickness, the long side, and the length of the short side can take any appropriate value. The thickness of the temporary fixing material can be, for example, 0.05 mm to 5.0 mm.

<< A-1. Foam >>
The foam contained in the temporarily fixing material of the present invention has an open cell structure having through holes between adjacent spherical cells. In the present specification, the “spherical bubble” does not have to be a strict true spherical bubble, and may be, for example, a substantially spherical bubble having a partial strain or a bubble composed of a space having a large strain. .

  The average pore diameter of the spherical bubbles of the foam is less than 20 μm, preferably 15 μm or less, and more preferably 10 μm or less. The lower limit value of the average pore diameter of the spherical bubbles of the foam is not particularly limited. For example, it is preferably 0.01 μm, more preferably 0.1 μm, and further preferably 1 μm. By keeping the average pore diameter of the spherical bubbles in the foam within the above range, the average pore diameter of the spherical bubbles in the foam can be precisely controlled to be small, excellent in flexibility and heat resistance, and practical even if the total thickness is 0.5 mm or less Possible temporary fixing materials can be provided.

The density of the foam is preferably ^{0.15g / cm 3 ~0.6g / cm 3} , more preferably from ^{0.15g / cm 3 ~0.5g / cm 3} , more preferably 0.15g / ^cm 3 was ～0.45G / cm ^3, particularly preferably from ^{0.15g / cm 3 ~0.4g / cm 3} . When the density of the foam falls within the above range, it is possible to provide a temporary fixing material excellent in flexibility and heat resistance while widely controlling the density range of the foam.

  The open cell structure of the foam may be an open cell structure having through holes between most or all adjacent spherical cells, or a semi-independent semi open cell structure having a relatively small number of through holes. There may be. By using the foam having such an open cell structure, the temporary fixing material of the present invention can have sufficient adhesive force. This is because when the article to be temporarily fixed is pressed against the adherend via the temporary fixing material of the present invention, the spherical bubbles and the through-holes inside the foam are compressed, and air is released to the outside, resulting in a large external damage. It is presumed that the adsorptivity is exhibited due to the pressure difference. Specifically, since the open cell structure extends in all directions inside the foam, air easily escapes outward by pressing. As a result, the air caught between the article and / or the adherend and the temporary fixing material at the time of pasting can be easily removed using the open cell structure, and a sufficient atmospheric pressure difference is generated. It is estimated that the excellent adsorptivity is exhibited. Moreover, since the adhesive force of the temporary fixing material of the present invention uses the adsorptive force as described above, the adhesiveness is not substantially lowered even when peeling and sticking are repeated, and the peelability is excellent. Further, even when the adhesiveness is reduced due to adhesion of dust or the like, the adhesiveness can be recovered by wiping with water washing or wet tissue.

  The through-holes between adjacent spherical bubbles affect the physical properties of the temporary fixing material. For example, the strength of the temporary fixing material tends to increase as the average hole diameter of the through holes decreases. FIG. 3 is a photographic view of a cross-sectional SEM photograph of a foam, and a photographic view clearly showing an open cell structure having through holes between adjacent spherical bubbles.

  The average pore diameter of the through holes between adjacent spherical bubbles is 5 μm or less, preferably 4 μm or less, more preferably 3 μm or less. The lower limit value of the average pore diameter of the through holes between adjacent spherical bubbles is not particularly limited, and is preferably 0.001 μm, and more preferably 0.01 μm, for example. When the average pore diameter of the through holes between adjacent spherical bubbles is within the above range, a temporary fixing material having excellent flexibility and heat resistance can be provided.

  The foam has a cell ratio of preferably 30% or more, more preferably 40% or more, and further preferably 50% or more. When the foam ratio of the foam falls within the above range, the temporary fixing material of the present invention can exhibit sufficient adhesive force, and can exhibit high flexibility and high heat resistance.

  In a preferred embodiment, the foam does not crack in a 180 ° bending test. By using a foam having such very good toughness, a temporarily fixing material that can be wound up like paper can be obtained.

  The foam has a tensile strength of preferably 0.1 MPa or more, more preferably 0.15 MPa or more, and further preferably 0.2 MPa or more. When the tensile strength of the foam is within the above range, the temporary fixing material of the present invention can have very excellent mechanical properties. The tensile strength is a value measured at a tensile speed of 50 mm / min according to JIS-K-7113.

  The foam has a tensile strength change rate of preferably less than ± 20% and more preferably ± 18% or less when stored at 125 ° C. for 14 days. In the said foam, when the tensile strength change rate when preserve | saved at 125 degreeC for 14 days is settled in the said range, the temporary fixing material of this invention may have the outstanding heat resistance. The rate of change in tensile strength was measured when the tensile strength was measured at a tensile speed of 50 mm / min in accordance with JIS-K-7113 before and after the measurement sample was stored in an oven at 125 ° C. for 14 days. It is the rate of change in tensile strength before and after the heat storage treatment.

  The above foam is stored for 22 hours at 80 ° C. in a 50% compressed state, then cooled to 23 ° C., and then the 50% compression strain recovery rate when 30 minutes have passed after releasing the compressed state is preferably 70%. Or more, more preferably 75% or more. In the foam having a 50% compression strain recovery rate in the above range, when a heavy article is placed on the foam or when a weight load is applied, the portion where pressure is applied is dented, but the pressure is released. In particular, the dent is excellent in recoverability (compression strain recovery). By using the foam having such excellent compressive strain recovery property, it is possible to obtain a temporary fixing material that is extremely excellent in repeated usability.

  Any appropriate material may be adopted as the foam forming material depending on the purpose. Moreover, arbitrary appropriate thickness can be employ | adopted as thickness of a foam according to the objective.

<< A-2. Base material >>
The temporary fixing material of the present invention may contain any appropriate base material as long as the effects of the present invention are not impaired. As a form in which the base material is contained in the temporarily fixing material of the present invention, for example, a form in which a base material layer is provided inside the temporarily fixed material can be mentioned. Examples of such a substrate include fiber woven fabric, fiber nonwoven fabric, fiber laminated fabric, fiber knitted fabric, resin sheet, metal foil film sheet, and inorganic fiber. Arbitrary appropriate thickness can be employ | adopted for the thickness of a base material according to material and the objective.

  As the fiber woven fabric, a woven fabric formed of any appropriate fiber can be adopted. Examples of such fibers include natural fibers such as plant fibers, animal fibers, and mineral fibers; artificial fibers such as regenerated fibers, synthetic fibers, semi-synthetic fibers, and artificial inorganic fibers. Examples of synthetic fibers include fibers obtained by melt spinning thermoplastic fibers. Further, the fiber woven fabric may be metallic processed by plating or sputtering.

  As a fiber nonwoven fabric, the nonwoven fabric formed from arbitrary appropriate fibers can be employ | adopted. Examples of such fibers include natural fibers such as plant fibers, animal fibers, and mineral fibers; artificial fibers such as regenerated fibers, synthetic fibers, semi-synthetic fibers, and artificial inorganic fibers. Examples of synthetic fibers include fibers obtained by melt spinning thermoplastic fibers. Moreover, the fiber nonwoven fabric may be metallic-processed by plating, sputtering, etc. More specifically, for example, a spunbond nonwoven fabric can be mentioned.

  As the fiber laminated fabric, a laminated fabric formed of any appropriate fiber can be adopted. Examples of such fibers include natural fibers such as plant fibers, animal fibers, and mineral fibers; artificial fibers such as regenerated fibers, synthetic fibers, semi-synthetic fibers, and artificial inorganic fibers. Examples of synthetic fibers include fibers obtained by melt spinning thermoplastic fibers. In addition, the fiber laminated fabric may be metallic processed by plating, sputtering, or the like. More specifically, for example, a polyester fiber laminated fabric can be mentioned.

  As a fiber knitted fabric, the knitted fabric formed from arbitrary appropriate fibers can be employ | adopted, for example. Examples of such fibers include natural fibers such as plant fibers, animal fibers, and mineral fibers; artificial fibers such as regenerated fibers, synthetic fibers, semi-synthetic fibers, and artificial inorganic fibers. Examples of synthetic fibers include fibers obtained by melt spinning thermoplastic fibers. Further, the fiber knitted fabric may be metallically processed by plating or sputtering.

  As the resin sheet, a sheet formed of any appropriate resin can be adopted. An example of such a resin is a thermoplastic resin. The resin sheet may be metallic processed by plating or sputtering.

  As the metal foil film sheet, a sheet formed from any appropriate metal foil film can be adopted.

  Any appropriate inorganic fiber can be adopted as the inorganic fiber. Specific examples of such inorganic fibers include glass fibers, metal fibers, and carbon fibers.

  In the temporarily fixing material of this invention, when a space | gap exists in a base material, the same material as the said foam may exist in a part or all of this space | gap.

  Only 1 type may be used for a base material and it may use 2 or more types together.

<< A-3. Adhesive layer >>
The temporary fixing material of the present invention may contain any appropriate pressure-sensitive adhesive layer as long as the effects of the present invention are not impaired. As a form in which the pressure-sensitive adhesive layer is contained in the temporarily fixing material of the present invention, for example, one of a foam or a laminate of a foam and a base material (first foam / base material / second foam) A form in which a pressure-sensitive adhesive layer is provided on the surface. As the pressure-sensitive adhesive forming the pressure-sensitive adhesive layer, any appropriate pressure-sensitive adhesive can be used depending on the purpose and the like. For example, acrylic adhesives, rubber adhesives, epoxy resin adhesives, silicone adhesives and the like can be mentioned. An adhesive can be used individually or in combination of 2 or more types.

  As the acrylic pressure-sensitive adhesive, a homopolymer of (meth) acrylic acid alkyl ester having 1 to 18 carbon atoms in the alkyl group, or a copolymerizable monomer such as the (meth) acrylic acid alkyl ester and other functional monomers A copolymer obtained by using as a base polymer can be preferably used. As a copolymer of (meth) acrylic acid alkyl ester and other copolymer monomer, a monomer composition containing (meth) acrylic acid alkyl ester is 50% by weight or more, more preferably 60% by weight or more is copolymerized. A copolymer obtained in this manner is preferred.

  Examples of the (meth) acrylic acid alkyl ester include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate, hexyl (meth) acrylate, ( Octyl acrylate, 2-ethylhexyl (meth) acrylate, isooctyl (meth) acrylate, decyl (meth) acrylate, isodecyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, etc. Is mentioned.

  Examples of the functional monomer include a monomer having a hydroxyl group, a monomer having a carboxyl group, a monomer having an amide group, and a monomer having an amino group. Examples of the hydroxyl group-containing monomer include hydroxyalkyl (meth) acrylates such as 2-hydroxyethyl (meth) acrylate and hydroxypropyl (meth) acrylate. Monomers having a carboxyl group include α, β-unsaturated carboxylic acids such as acrylic acid, methacrylic acid and crotonic acid; maleic acid monoalkyl esters such as butyl maleate; unsaturated compounds such as maleic acid, fumaric acid and itaconic acid Examples of the dibasic acid anhydride include dibasic acid anhydrides such as maleic anhydride. Examples of the monomer having an amide group include acrylamide, dimethyl (meth) acrylamide, alkyl (meth) acrylamide such as diethyl (meth) acrylamide, N-butoxymethyl (meth) acrylamide, N-ethoxymethyl (meth) acrylamide and the like. Examples thereof include alkoxymethyl (meth) acrylamide and diacetone (meth) acrylamide. Examples of the monomer having an amino group include dimethylaminoethyl (meth) acrylate. As copolymerizable monomers other than those described above, vinyl acetate, styrene, α-methylstyrene, vinyl chloride, acrylonitrile, ethylene, propylene, and the like can also be used.

  Rubber-based adhesives include rubber elastic materials such as natural rubber, styrene-isoprene block copolymer, styrene-butadiene block copolymer, polyisoprene, polybutene, polyisobutylene, and ethylene-vinyl acetate copolymer. The thing made into a polymer is mentioned. In addition to the rubber elastic body, for example, an appropriate amount of a tackifier such as a rosin resin, a polyterpene resin, a coumarone-indene resin, a petroleum resin, a terpene-phenol resin, etc. Softening agents such as liquid polybutene, mineral oil, liquid polyisoprene, and liquid polyacrylate can be blended.

  Examples of the silicone pressure-sensitive adhesive include those containing silicone rubber and silicone resin. As the silicone rubber and the silicone resin, any appropriate silicone rubber component and resin used in ordinary silicone pressure-sensitive adhesives can be used.

  The pressure-sensitive adhesive layer may contain any appropriate support depending on the purpose and the like. Examples of the form in which the pressure-sensitive adhesive layer contains a support include a form in which a support layer is provided inside the pressure-sensitive adhesive layer. The pressure-sensitive adhesive layer containing the support can be, for example, a first pressure-sensitive adhesive layer / support / second pressure-sensitive adhesive layer. Examples of such a support include fiber woven fabric, fiber nonwoven fabric, fiber laminated fabric, fiber knitted fabric, resin sheet, metal foil membrane sheet, inorganic fiber, etc. Similar explanations are applicable. The support may be formed from one type of material, or may be formed from two or more types of materials. The support may be a single layer or a laminate. Arbitrary appropriate thickness can be employ | adopted for the thickness of a support body according to material and the objective.

  The pressure-sensitive adhesive layer may have a thickness (total thickness in the case of a laminated structure) of, for example, 5 μm to 500 μm, preferably 5 μm to 200 μm.

≪B. Temporary fixing material manufacturing method 1 >>
The temporary fixing material of the present invention can be manufactured by any appropriate method. For example, the temporary fixing material of the present invention comprising the foam can be obtained by the foam production method described in detail below.

  As a method for producing the foam, for example, a continuous oil phase component and an aqueous phase component are continuously supplied to an emulsifier to prepare a W / O emulsion that can be used to obtain the foam, There is a “continuous method” in which the obtained W / O emulsion is polymerized to produce a water-containing polymer, and then the obtained water-containing polymer is dehydrated. As the method for producing the foam, for example, an appropriate amount of an aqueous phase component with respect to a continuous oil phase component is charged into an emulsifier, and the aqueous phase component is continuously supplied while stirring, to thereby produce the foam. A W / O emulsion that can be used to obtain a polymer, and the resulting W / O emulsion is polymerized to produce a hydrous polymer, followed by dehydration of the hydrous polymer obtained. ".

  The continuous polymerization method in which the W / O emulsion is continuously polymerized is a preferable method because the production efficiency is high and the effect of shortening the polymerization time and the shortening of the polymerization apparatus can be most effectively utilized.

More specifically, the method for producing the foam is as follows.
A step (I) of preparing a W / O type emulsion;
Step (II) of shaping the obtained W / O emulsion,
Polymerizing the shaped W / O emulsion (III);
Step (IV) of dehydrating the obtained hydrous polymer;
including. Here, at least a part of the step (II) for shaping the obtained W / O emulsion and the step (III) for polymerizing the shaped W / O emulsion may be performed simultaneously.

<< B-1. Step for preparing W / O type emulsion (I) >>
The W / O type emulsion is a W / O type emulsion containing a continuous oil phase component and an aqueous phase component immiscible with the continuous oil phase component. More specifically, the W / O type emulsion is obtained by dispersing an aqueous phase component in a continuous oil phase component.

  The ratio of the water phase component to the continuous oil phase component in the W / O type emulsion may be any appropriate ratio as long as the W / O type emulsion can be formed. The ratio of the water phase component to the continuous oil phase component in the W / O emulsion determines the structural, mechanical and performance characteristics of the porous polymer material obtained by polymerization of the W / O emulsion. Can be an important factor. Specifically, the ratio of the water phase component to the continuous oil phase component in the W / O type emulsion that can be used to obtain the foam is determined by the porous polymer material obtained by polymerization of the W / O type emulsion. It can be an important factor in determining the density, the bubble size, the bubble structure, and the dimensions of the walls forming the porous structure.

  The ratio of the water phase component in the W / O type emulsion is preferably 30% by weight, more preferably 40% by weight, still more preferably 50% by weight, and particularly preferably 55% by weight as the lower limit. The upper limit is preferably 95% by weight, more preferably 90% by weight, still more preferably 85% by weight, and particularly preferably 80% by weight. If the ratio of the aqueous phase component in the W / O emulsion is within the above range, the effects of the present invention can be sufficiently exhibited.

  The W / O emulsion can contain any appropriate additive as long as the effects of the present invention are not impaired. Examples of such additives include tackifying resins; talc; calcium carbonate, magnesium carbonate, silicic acid and salts thereof, clay, mica powder, aluminum hydroxide, magnesium hydroxide, zinc white, bentonine, carbon black, Examples thereof include fillers such as silica, alumina, aluminum silicate, acetylene black, and aluminum powder; pigments; dyes; Only one kind of such an additive may be contained, or two or more kinds thereof may be contained.

  Arbitrary appropriate methods can be employ | adopted as a method of manufacturing a W / O type | mold emulsion. As a method for producing a W / O type emulsion that can be used to obtain the foam, for example, a continuous oil phase component and an aqueous phase component are continuously supplied to an emulsifier to form a W / O type emulsion. “Batch” to form a W / O type emulsion by adding an appropriate amount of aqueous phase component to the continuous oil phase component in an emulsifier and continuously supplying the aqueous phase component while stirring. Law ".

  Examples of the shearing means for obtaining the emulsion state when producing the W / O type emulsion include application of high shear conditions using a rotor-stator mixer, a homogenizer, a microfluidizer, and the like. In addition, as another shearing means for obtaining an emulsion state, for example, gentle mixing of continuous and dispersed phases by application of low shear conditions using a moving blade mixer or a pin mixer, low stirring conditions using a magnetic stir bar, etc. Can be mentioned. Specifically, “TK Aji homomixer” and “TK combimix” manufactured by Primix Co., Ltd. can produce a desired W / O emulsion under reduced pressure. In the W / O type emulsion, mixing of bubbles can be significantly reduced.

  Examples of the apparatus for preparing the W / O emulsion by the “continuous method” include a static mixer, a rotor stator mixer, and a pin mixer. More intense agitation may be achieved by increasing the agitation speed or by using an apparatus designed to finely disperse the aqueous phase component in the W / O emulsion by a mixing method.

  Examples of the apparatus for preparing the W / O type emulsion by the “batch method” include manual mixing and shaking, a driven blade mixer, and three propeller mixing blades.

  Arbitrary appropriate methods can be employ | adopted as a method of preparing a continuous oil phase component. As a method for preparing the continuous oil phase component, typically, for example, a mixed syrup containing a hydrophilic polyurethane-based polymer and an ethylenically unsaturated monomer is prepared, and subsequently, a polymerization initiator, It is preferable to prepare a continuous oil phase component by blending a crosslinking agent and any other appropriate components.

  Any appropriate method can be adopted as a method of preparing the hydrophilic polyurethane-based polymer. A typical method for preparing a hydrophilic polyurethane-based polymer is, for example, by reacting polyoxyethylene polyoxypropylene glycol and a diisocyanate compound in the presence of a urethane reaction catalyst.

<< B-1-1. Water phase component >>
The aqueous phase component can be any aqueous fluid that is substantially immiscible with the continuous oil phase component. From the viewpoint of ease of handling and low cost, water such as ion-exchanged water is preferable.

  Any appropriate additive may be contained in the aqueous phase component as long as the effects of the present invention are not impaired. Examples of such additives include polymerization initiators and water-soluble salts. The water-soluble salt can be an effective additive for further stabilizing the W / O emulsion. Examples of such water-soluble salts include sodium carbonate, calcium carbonate, potassium carbonate, sodium phosphate, calcium phosphate, potassium phosphate, sodium chloride, potassium chloride and the like. Only one kind of such an additive may be contained, or two or more kinds thereof may be contained. The additive that can be contained in the aqueous phase component may be only one kind or two or more kinds.

<< B-1-2. Continuous oil phase component >>
The continuous oil phase component includes a hydrophilic polyurethane polymer, an ethylenically unsaturated monomer, and a crosslinking agent. The content ratio of the hydrophilic polyurethane polymer and the ethylenically unsaturated monomer in the continuous oil phase component can take any appropriate content ratio as long as the effects of the present invention are not impaired.

  The hydrophilic polyurethane-based polymer depends on the polyoxyethylene ratio in the polyoxyethylene polyoxypropylene glycol unit constituting the hydrophilic polyurethane-based polymer or the amount of the aqueous phase component to be blended. The hydrophilic polyurethane polymer is in the range of 10 to 30 parts by weight with respect to 70 to 90 parts by weight of the ethylenically unsaturated monomer, and more preferably hydrophilic to 75 to 90 parts by weight of the ethylenically unsaturated monomer. The polyurethane polymer is in the range of 10 to 25 parts by weight. Further, for example, the hydrophilic polyurethane polymer is preferably in the range of 1 to 30 parts by weight, more preferably 1 to 25 parts by weight of the hydrophilic polyurethane polymer with respect to 100 parts by weight of the aqueous phase component. It is a range. If the content ratio of the hydrophilic polyurethane polymer is within the above range, the effects of the present invention can be sufficiently exhibited.

<< B-2-1-1. Hydrophilic polyurethane polymer >>
The hydrophilic polyurethane-based polymer contains polyoxyethylene polyoxypropylene units derived from polyoxyethylene polyoxypropylene glycol, and 5 wt% to 25 wt% in the polyoxyethylene polyoxypropylene units is polyoxyethylene. It is preferable.

  The content ratio of polyoxyethylene in the polyoxyethylene polyoxypropylene unit is preferably 5% by weight to 25% by weight as described above, and preferably 10% by weight as a lower limit, and more preferably 15%. The upper limit is preferably 25% by weight, and more preferably 20% by weight. The polyoxyethylene in the polyoxyethylene polyoxypropylene unit exhibits an effect of stably dispersing the aqueous phase component in the continuous oil phase component. When the content of polyoxyethylene in the polyoxyethylene polyoxypropylene unit is less than 5% by weight, it may be difficult to stably disperse the water phase component in the continuous oil phase component. If the polyoxyethylene content in the polyoxyethylene polyoxypropylene unit exceeds 25% by weight, there is a risk of phase inversion from a W / O type emulsion to an O / W type (oil-in-water type) emulsion as it approaches the HIPE condition. There is.

  A conventional hydrophilic polyurethane polymer can be obtained by reacting a diisocyanate compound with a hydrophobic long-chain diol, polyoxyethylene glycol and derivatives thereof, and a low molecular active hydrogen compound (chain extender). Since the number of polyoxyethylene groups contained in the hydrophilic polyurethane polymer obtained in 1) is uneven, the emulsion stability of such a W / O emulsion containing such a hydrophilic polyurethane polymer may be reduced. There is. On the other hand, the hydrophilic polyurethane-based polymer contained in the continuous oil phase component of the W / O emulsion has the characteristic structure as described above, so that it is included in the continuous oil phase component of the W / O emulsion. In some cases, excellent emulsifying properties and excellent stationary storage stability can be exhibited without positively adding an emulsifier or the like.

  The hydrophilic polyurethane-based polymer is preferably obtained by reacting polyoxyethylene polyoxypropylene glycol and a diisocyanate compound. In this case, the ratio between the polyoxyethylene polyoxypropylene glycol and the diisocyanate compound is NCO / OH (equivalent ratio), and the lower limit is preferably 1, more preferably 1.2, and still more preferably 1. .4, particularly preferably 1.6, and the upper limit is preferably 3, more preferably 2.5, and even more preferably 2. When NCO / OH (equivalent ratio) is less than 1, a gelled product may be easily formed when a hydrophilic polyurethane polymer is produced. When NCO / OH (equivalent ratio) exceeds 3, the amount of residual diisocyanate compound increases and the W / O emulsion may become unstable.

  As polyoxyethylene polyoxypropylene glycol, for example, polyether polyol (ADEKA (registered trademark) Pluronic L-31, L-61, L-71, L-101, L-121, L-42 manufactured by ADEKA Corporation) , L-62, L-72, L-122, 25R-1, 25R-2, 17R-2) and polyoxyethylene polyoxypropylene glycol (Pronon (registered trademark) 052, 102, manufactured by NOF Corporation. 202). As for polyoxyethylene polyoxypropylene glycol, only 1 type may be used and 2 or more types may be used together.

  Examples of the diisocyanate compound include aromatic, aliphatic, and alicyclic diisocyanates, dimers and trimers of these diisocyanates, polyphenylmethane polyisocyanate, and the like. Aromatic, aliphatic, and alicyclic diisocyanates include tolylene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, xylylene diisocyanate, hydrogenated xylylene diisocyanate, isophorone diisocyanate, hydrogenated diphenylmethane diisocyanate, 1,5-naphthylene diisocyanate. 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, butane-1,4-diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, cyclohexane-1,4 -Diisocyanate, dicyclohexylmethane-4,4-diisocyanate, 1,3-bis (isocyanatemethyl) cyclohexane, methyl Cyclohexane diisocyanate, m- tetramethylxylylene diisocyanate. Examples of the diisocyanate trimer include isocyanurate type, burette type, and allophanate type. Only 1 type may be used for a diisocyanate compound and it may use 2 or more types together.

  The diisocyanate compound may be selected as appropriate from the viewpoint of urethane reactivity with the polyol and the like, as well as the type and combination thereof. From the viewpoint of rapid urethane reactivity with polyol and suppression of reaction with water, it is preferable to use alicyclic diisocyanate.

  The weight average molecular weight of the hydrophilic polyurethane polymer is preferably 5000 as a lower limit, more preferably 7000, still more preferably 8000, particularly preferably 10,000, and preferably 50,000 as an upper limit. More preferably, it is 40000, more preferably 30000, and particularly preferably 20000.

  The hydrophilic polyurethane polymer may have an unsaturated double bond capable of radical polymerization at the terminal. By having an unsaturated double bond capable of radical polymerization at the terminal of the hydrophilic polyurethane-based polymer, the effects of the present invention can be further exhibited.

<< B-1-2-2. Ethylenically unsaturated monomer >>
As the ethylenically unsaturated monomer, any appropriate monomer can be adopted as long as it is a monomer having an ethylenically unsaturated double bond. Only one type of ethylenically unsaturated monomer may be used, or two or more types may be used.

  The ethylenically unsaturated monomer preferably comprises a (meth) acrylic ester. The content ratio of the (meth) acrylic acid ester in the ethylenically unsaturated monomer is preferably 80% by weight, more preferably 85% by weight as the lower limit, and preferably 100% by weight as the upper limit. More preferably, it is 98% by weight. Only one (meth) acrylic acid ester may be used, or two or more may be used.

  The (meth) acrylic acid ester is preferably an alkyl (meth) acrylate having an alkyl group having 1 to 20 carbon atoms (a concept including a cycloalkyl group, an alkyl (cycloalkyl) group, and a (cycloalkyl) alkyl group). It is. Preferably the carbon number of the said alkyl group is 4-18. In addition, (meth) acryl means acryl and / or methacryl, and (meth) acrylate means acrylate and / or methacrylate.

  Examples of the alkyl (meth) acrylate having an alkyl group having 1 to 20 carbon atoms include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate, and s-butyl. (Meth) acrylate, t-butyl (meth) acrylate, isobutyl (meth) acrylate, n-pentyl (meth) acrylate, isopentyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, isoamyl (meth) Acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, isooctyl (meth) acrylate, n-nonyl (meth) acrylate, isononyl (meth) acrylate, n-decyl (meth) acrylate, isode Ru (meth) acrylate, n-dodecyl (meth) acrylate, isomyristyl (meth) acrylate, n-tridecyl (meth) acrylate, n-tetradecyl (meth) acrylate, stearyl (meth) acrylate, lauryl (meth) acrylate, pentadecyl Examples include (meth) acrylate, hexadecyl (meth) acrylate, heptadecyl (meth) acrylate, octadecyl (meth) acrylate, nonadecyl (meth) acrylate, eicosyl (meth) acrylate, and isostearyl (meth) acrylate. Among these, n-butyl (meth) acrylate and 2-ethylhexyl (meth) acrylate are preferable. Only 1 type may be sufficient as the alkyl (meth) acrylate which has a C1-C20 alkyl group, and 2 or more types may be sufficient as it.

  The ethylenically unsaturated monomer preferably further comprises a polar monomer copolymerizable with the (meth) acrylic acid ester. The content of the polar monomer in the ethylenically unsaturated monomer is preferably 0% by weight, more preferably 2% by weight as the lower limit, and preferably 20% by weight, more preferably as the upper limit. 15% by weight. Only one type of polar monomer may be used, or two or more types may be used.

  Examples of polar monomers include (meth) acrylic acid, carboxyethyl (meth) acrylate, carboxypentyl (meth) acrylate, ω-carboxy-polycaprolactone monoacrylate, phthalic acid monohydroxyethyl acrylate, itaconic acid, maleic acid, fumaric acid Carboxyl group-containing monomers such as acid and crotonic acid; acid anhydride monomers such as maleic anhydride and itaconic anhydride; 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, and (meth) acrylic acid 4-hydroxybutyl, 6-hydroxyhexyl (meth) acrylate, 8-hydroxyoctyl (meth) acrylate, 10-hydroxydecyl (meth) acrylate, 12-hydroxylauryl (meth) acrylate, (4-hydroxymethyl Shi Hydroxyl group-containing monomers such as cyclohexyl) methyl (meth) acrylate; amide group-containing monomers such as N, N-dimethyl (meth) acrylamide, N, N-diethyl (meth) acrylamide, and hydroxyethyl (meth) acrylamide; It is done.

<< B-1-2-3. Polymerization initiator >>
The continuous oil phase component preferably contains a polymerization initiator.

  Examples of the polymerization initiator include radical polymerization initiators and redox polymerization initiators. Examples of the radical polymerization initiator include a thermal polymerization initiator and a photopolymerization initiator.

  Examples of the thermal polymerization initiator include azo compounds, peroxides, peroxycarbonic acid, peroxycarboxylic acid, potassium persulfate, t-butylperoxyisobutyrate, and 2,2′-azobisisobutyronitrile. .

  Examples of the photopolymerization initiator include 4- (2-hydroxyethoxy) phenyl (2-hydroxy-2-propyl) ketone (for example, Ciba Japan, trade name: Darocur-2959), α-hydroxy- α, α'-dimethylacetophenone (for example, Ciba Japan, trade name: Darocur-1173), methoxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone (for example, Ciba Japan, trade name) Acetophenone photopolymerization initiators such as Irgacure-651) and 2-hydroxy-2-cyclohexylacetophenone (for example, Ciba Japan, trade name; Irgacure-184); Ketal photopolymerization initiator such as benzyldimethyl ketal Agents; Other halogenated ketones; Acylphosphine oxides (As an example, Ciba Japan Co., Ltd., trade name: Irgacure -819); and the like.

  The polymerization initiator may contain only 1 type and may contain 2 or more types.

  The content of the polymerization initiator is preferably 0.05% by weight, more preferably 0.1% by weight, more preferably 0.1%, and preferably 5.0% as a lower limit with respect to the entire continuous oil phase component. % By weight, more preferably 1.0% by weight. If the content of the polymerization initiator is less than 0.05% by weight based on the entire continuous oil phase component, the amount of unreacted monomer components increases, and the amount of residual monomers in the resulting porous material may increase. is there. When the content of the polymerization initiator exceeds 5.0% by weight with respect to the entire continuous oil phase component, the mechanical properties of the resulting porous material may be reduced.

  Note that the amount of radicals generated by the photopolymerization initiator varies depending on the type and intensity of light to be irradiated, the irradiation time, the amount of dissolved oxygen in the monomer and solvent mixture, and the like. And when there is much dissolved oxygen, the radical generation amount by a photoinitiator is suppressed, superposition | polymerization does not fully advance and an unreacted substance may increase. Therefore, it is preferable that an inert gas such as nitrogen is blown into the reaction system before the light irradiation, and oxygen is replaced with an inert gas or deaerated by a reduced pressure treatment.

<< B-1-2-4. Cross-linking agent >>
The continuous oil phase component includes a crosslinking agent.

  Crosslinking agents are typically used to link polymer chains together to build a more three-dimensional molecular structure. The choice of the type and content of the cross-linking agent depends on the structural properties, mechanical properties, and fluid treatment properties desired for the resulting porous material. The selection of the specific type and content of the cross-linking agent is important in achieving the desired combination of structural properties, mechanical properties, and fluid treatment properties of the porous material.

  In the foam production method, it is preferable to use at least two types of crosslinking agents having different weight average molecular weights as crosslinking agents.

  In the foam production method, more preferably, the crosslinking agent is “one kind selected from polyfunctional (meth) acrylates having a weight average molecular weight of 800 or more, polyfunctional (meth) acrylamides, and polymerization-reactive oligomers”. “Above” and “one or more selected from polyfunctional (meth) acrylates and polyfunctional (meth) acrylamides having a weight average molecular weight of 500 or less” are used in combination. Here, the polyfunctional (meth) acrylate is specifically a polyfunctional (meth) acrylate having at least two ethylenically unsaturated groups in one molecule, and the polyfunctional (meth) acrylamide is Specifically, it is polyfunctional (meth) acrylamide having at least two ethylenically unsaturated groups in one molecule.

  Examples of the polyfunctional (meth) acrylate include diacrylates, triacrylates, tetraacrylates, dimethacrylates, trimethacrylates, and tetramethacrylates.

  Examples of the polyfunctional (meth) acrylamide include diacrylamides, triacrylamides, tetraacrylamides, dimethacrylamides, trimethacrylamides, tetramethacrylamides and the like.

  The polyfunctional (meth) acrylate can be derived from, for example, diols, triols, tetraols, bisphenol A and the like. Specifically, for example, 1,10-decanediol, 1,8-octanediol, 1,6 hexane-diol, 1,4-butanediol, 1,3-butanediol, 1,4 butane-2-enedi It can be derived from all, ethylene glycol, diethylene glycol, trimethylolpropane, pentaerythritol, hydroquinone, catechol, resorcinol, triethylene glycol, polyethylene glycol, sorbitol, polypropylene glycol, polytetramethylene glycol, bisphenol A propylene oxide modified product, and the like.

  The polyfunctional (meth) acrylamide can be derived from, for example, corresponding diamines, triamines, tetraamines and the like.

  Examples of the polymerization reactive oligomer include urethane (meth) acrylate, epoxy (meth) acrylate, copolyester (meth) acrylate, oligomer di (meth) acrylate and the like. Preferably, it is hydrophobic urethane (meth) acrylate.

  The weight average molecular weight of the polymerization reactive oligomer is preferably 1500 or more, more preferably 2000 or more. Although the upper limit of the weight average molecular weight of a polymerization reactive oligomer is not specifically limited, For example, Preferably it is 10,000 or less.

  As the cross-linking agent, “one or more selected from polyfunctional (meth) acrylates having a weight average molecular weight of 800 or more, polyfunctional (meth) acrylamides, and polymerization reactive oligomers” and “a weight average molecular weight of 500 or less. When using together with “one or more selected from functional (meth) acrylate and polyfunctional (meth) acrylamide” ”,“ polyfunctional (meth) acrylate having a weight average molecular weight of 800 or more, polyfunctional (meth) acrylamide, and polymerization ” The amount of “one or more selected from reactive oligomers” is preferably 30% by weight as a lower limit with respect to the total amount of the hydrophilic polyurethane polymer and the ethylenically unsaturated monomer in the continuous oil phase component. The upper limit is preferably 100% by weight, and more preferably 80% by weight. The amount of use of “one or more selected from a polyfunctional (meth) acrylate having a weight average molecular weight of 800 or more, a polyfunctional (meth) acrylamide, and a polymerization reactive oligomer” is a hydrophilic polyurethane-based heavy in the continuous oil phase component If it is less than 30% by weight based on the total amount of coalesced and ethylenically unsaturated monomer, the cohesive strength of the resulting foam may be reduced, and it may be difficult to achieve both toughness and flexibility. . The amount of use of “one or more selected from a polyfunctional (meth) acrylate having a weight average molecular weight of 800 or more, a polyfunctional (meth) acrylamide, and a polymerization reactive oligomer” is a hydrophilic polyurethane-based heavy in the continuous oil phase component When it exceeds 100 weight% with respect to the total amount of a coalescence and an ethylenically unsaturated monomer, the emulsion stability of a W / O type emulsion will fall, and there exists a possibility that a desired foam may not be obtained.

  As the cross-linking agent, “one or more selected from polyfunctional (meth) acrylates having a weight average molecular weight of 800 or more, polyfunctional (meth) acrylamides, and polymerization reactive oligomers” and “a weight average molecular weight of 500 or less. When using together with “one or more selected from functional (meth) acrylate and polyfunctional (meth) acrylamide” ”,“ selected from polyfunctional (meth) acrylate and polyfunctional (meth) acrylamide having a weight average molecular weight of 500 or less ” The amount of “one or more” used is preferably 1% by weight, more preferably 5% as a lower limit with respect to the total amount of the hydrophilic polyurethane polymer and the ethylenically unsaturated monomer in the continuous oil phase component. The upper limit is preferably 30% by weight, and more preferably 20% by weight. Use amount of “one or more selected from polyfunctional (meth) acrylate having a weight average molecular weight of 500 or less and polyfunctional (meth) acrylamide” is a hydrophilic polyurethane polymer and ethylenic unsaturated in a continuous oil phase component When the amount is less than 1% by weight based on the total amount of monomers, the heat resistance is lowered, and the cell structure may be crushed by contraction in the step (IV) of dehydrating the water-containing polymer. Use amount of “one or more selected from polyfunctional (meth) acrylate having a weight average molecular weight of 500 or less and polyfunctional (meth) acrylamide” is a hydrophilic polyurethane polymer and ethylenic unsaturated in a continuous oil phase component When it exceeds 30 weight% with respect to the total amount of a monomer, the toughness of the foam obtained may fall and there exists a possibility of showing brittleness.

  The crosslinking agent may contain only 1 type and may contain 2 or more types.

<< B-1-2-5. Other components in the continuous oil phase component >>
The continuous oil phase component may contain any appropriate other component as long as the effects of the present invention are not impaired. Examples of such other components typically include a catalyst, an antioxidant, a light stabilizer, and an organic solvent. Such other components may be only one type or two or more types.

  Examples of the catalyst include a urethane reaction catalyst. Any appropriate catalyst can be adopted as the urethane reaction catalyst. Specific examples include dibutyltin dilaurate and acetylacetone metal complexes.

  Arbitrary appropriate content rates can be employ | adopted for the content rate of a catalyst according to the target catalytic reaction.

  The catalyst may contain only 1 type and may contain 2 or more types.

  Examples of the antioxidant include a phenol-based antioxidant, a thioether-based antioxidant, and a phosphorus-based antioxidant.

  Arbitrary appropriate content rates can be employ | adopted for the content rate of antioxidant in the range which does not impair the effect of this invention.

  Antioxidant may contain only 1 type and may contain 2 or more types.

  Any appropriate light stabilizer can be adopted as the light stabilizer as long as the effects of the present invention are not impaired.

  Arbitrary appropriate content rates can be employ | adopted for the content rate of a light stabilizer in the range which does not impair the effect of this invention.

  The light stabilizer may contain only 1 type and may contain 2 or more types.

  Any appropriate organic solvent can be adopted as the organic solvent as long as the effects of the present invention are not impaired.

  Arbitrary appropriate content rates can be employ | adopted for the content rate of an organic solvent in the range which does not impair the effect of this invention.

  The organic solvent may contain only 1 type and may contain 2 or more types.

<< B-2. Step of shaping W / O type emulsion (II) >>
In the step (II), any appropriate shaping method can be adopted as a method for shaping the W / O type emulsion. For example, there is a method in which a W / O emulsion is continuously supplied onto a traveling belt and shaped into a smooth sheet on the belt. Moreover, the method of apply | coating to one surface of a thermoplastic resin film, and shaping is mentioned.

  In the step (II), as a method of shaping the W / O type emulsion, when adopting a method of coating and shaping on one surface of a thermoplastic resin film, as a method of coating, for example, a roll coater, Examples include a method using a die coater, a knife coater, or the like.

<< B-3. Step of polymerizing shaped W / O emulsion (III) >>
In the step (III), any appropriate polymerization method can be adopted as a method for polymerizing the shaped W / O emulsion. For example, the belt surface of a belt conveyor is heated by a heating device, and a W / O type emulsion is continuously supplied onto a traveling belt and shaped into a smooth sheet on the belt by heating. A W / O emulsion is continuously supplied onto the running belt, with a method of polymerization and a structure in which the belt surface of the belt conveyor is heated by irradiation of active energy rays, and a smooth sheet is formed on the belt. The method of superposing | polymerizing by irradiation of an active energy ray is mentioned, shaping.

  In the case of polymerization by heating, the polymerization temperature (heating temperature) is preferably 23 ° C., more preferably 50 ° C., still more preferably 70 ° C., particularly preferably 80 ° C. as the lower limit. The upper limit is preferably 90 ° C, and is preferably 150 ° C, more preferably 130 ° C, and even more preferably 110 ° C. When the polymerization temperature is less than 23 ° C., the polymerization takes a long time, and industrial productivity may be reduced. When the polymerization temperature exceeds 150 ° C., the pore size of the obtained foam may be non-uniform or the strength of the foam may be reduced. The polymerization temperature need not be constant. For example, the polymerization temperature may be varied in two stages or multiple stages during the polymerization.

  In the case of polymerization by irradiation with active energy rays, examples of the active energy rays include ultraviolet rays, visible rays, and electron beams. The active energy ray is preferably ultraviolet light or visible light, and more preferably visible to ultraviolet light having a wavelength of 200 nm to 800 nm. Since the W / O type emulsion has a strong tendency to scatter light, it is possible to penetrate the W / O type emulsion by using visible to ultraviolet light having a wavelength of 200 nm to 800 nm. Moreover, the photoinitiator which can be activated with a wavelength of 200 nm-800 nm is easy to obtain, and a light source is easy to obtain.

  The wavelength of the active energy ray is preferably 200 nm, more preferably 300 nm as the lower limit value, and preferably 800 nm, more preferably 450 nm as the upper limit value.

  As a typical apparatus used for irradiation of active energy rays, for example, an ultraviolet lamp capable of performing ultraviolet irradiation includes an apparatus having a spectral distribution in a wavelength region of 300 to 400 nm. , Black light (trade name manufactured by Toshiba Lighting & Technology Co., Ltd.), metal halide lamp and the like.

  The illuminance at the time of irradiation with active energy rays can be set to any appropriate illuminance by adjusting the distance from the irradiation device to the irradiation object and the voltage. For example, by the method disclosed in Japanese Patent Application Laid-Open No. 2003-13015, ultraviolet irradiation in each step is performed in a plurality of stages, and thereby the efficiency of the polymerization reaction can be precisely adjusted.

  In order to prevent the adverse effect of oxygen having an inhibitory action on the ultraviolet rays, for example, a W / O emulsion is applied to one surface of a substrate such as a thermoplastic resin film and then shaped under an inert gas atmosphere. UV rays such as polyethylene terephthalate coated with a release agent such as silicone after passing through a W / O emulsion on one surface of a substrate such as a thermoplastic resin film and shaping, but blocking oxygen It is preferable to carry out by covering the film.

  As the thermoplastic resin film, any appropriate thermoplastic resin film can be adopted as long as it can be formed by coating a W / O emulsion on one surface. Examples of the thermoplastic resin film include plastic films and sheets such as polyester, olefin resin, and polyvinyl chloride. Further, the film may be subjected to a peeling treatment on one side or both sides thereof.

  The inert gas atmosphere refers to an atmosphere in which oxygen in the light irradiation zone is replaced with an inert gas. Therefore, in the inert gas atmosphere, it is necessary that oxygen is not present as much as possible, and the oxygen concentration is preferably 5000 ppm or less.

<< B-4. Step of dehydrating the obtained water-containing polymer (IV) >>
In step (IV), the obtained water-containing polymer is dehydrated. In the water-containing polymer obtained in step (III), the aqueous phase component is present in a dispersed state. By removing the aqueous phase component by dehydration and drying, a foam is obtained.

  Arbitrary appropriate drying methods can be employ | adopted as a dehydration method in process (IV). Examples of such a drying method include vacuum drying, freeze drying, press drying, microwave drying, drying in a heat oven, drying with infrared rays, or a combination of these techniques.

≪C. Temporary fixing material manufacturing method 2 >>
When the temporary fixing material of the present invention includes a base material, a preferred method for producing the temporary fixing material of the present invention is to apply a W / O emulsion to one surface of an ultraviolet transmissive film coated with a release agent such as silicone. Two of the two are prepared, a base material is laminated on the coated surface of one of the two W / O emulsion coated sheets, and another W / O is placed on the other surface of the laminated base material. In a state where the coated surfaces of the O-type emulsion coated sheets are laminated, the W / O-type emulsion is polymerized by heating or irradiation with active energy rays to form a hydrous polymer, and the obtained hydrous polymer is dehydrated. By doing, the method of obtaining the temporary fixing material which has the laminated structure of a foam layer / base material / foam layer is mentioned.

  When the base material is a non-woven fabric or other air-permeable sheet, as another manufacturing method, a tension is applied to a W / O emulsion applied to one surface of an ultraviolet transmissive film coated with a release agent such as silicone. The substrate was laminated while being applied, impregnated with the W / O emulsion applied in the laminated substrate, and another peeling treatment was performed on the W / O emulsion layer formed on the substrate by leaching. In a state where the films are laminated, the W / O emulsion is polymerized by heating or irradiation with active energy rays to form a water-containing polymer, and the resulting water-containing polymer is dehydrated to obtain a foam layer / substrate / A method for obtaining a temporary fixing material having a laminated structure of foamed layers is exemplified.

  Examples of the method of coating the W / O type emulsion on one side of the base material or one surface of the ultraviolet ray transmissive film coated with a release agent such as silicone include a roll coater, a die coater, and a knife coater.

≪D. Temporary fixing material manufacturing method 3 >>
When the temporary fixing material of the present invention includes an adhesive layer, a preferred method for producing the temporary fixing material of the present invention is a foam or a laminate of a foam and a substrate obtained in the same manner as in the above manufacturing method 1 or 2. A method of laminating an adhesive layer on one surface of the body is mentioned. The laminating means is not particularly limited, and for example, the pressure-sensitive adhesive layer is laminated by directly applying and drying a pressure-sensitive adhesive composition containing a pressure-sensitive adhesive, a solvent, etc. to the foam or a laminate of the foam and the substrate. be able to. Alternatively, the pressure-sensitive adhesive layer may be formed in advance by applying and drying the pressure-sensitive adhesive composition on the release film, and the pressure-sensitive adhesive layer may be transferred to one side of the foam or laminate. The temporary fixing material in which the pressure-sensitive adhesive layer includes a support is, for example, provided with a pressure-sensitive adhesive layer on both sides of the support by transferring the pressure-sensitive adhesive layer formed on the release film to the support in the same manner as described above. It can be obtained by bonding to one side of a foam or a laminate of a foam and a substrate.

≪E. Applications of temporary fixing materials >>
The temporary fixing material of the present invention is typically used for temporarily fixing a desired article to any appropriate adherend surface. As specific application examples of the temporary fixing material of the present invention, for example, advertisements, calendars, drawings, memos, photographs, various products (for example, portable electronic devices such as mobile phones and portable game machines) or the like are exhibited or Temporary fixing material or temporary fixing board for posting; Temporary fixing material for temporarily fixing cards, coins, touch pens, accessories, etc. to mobile phones, etc .; Coins, glasses, mobile phones, accessories, etc. on automobile dashboards Temporary fixing material or temporary fixing board for placing small items; light-shielding sheet in the car; temporary fixing material that is stacked on the wireless transmission charging equipment and temporarily fixing the object to be charged on the equipment; processing and holding materials such as semiconductor materials and color filters ; Carrier sheets such as circuit boards and thin film glass modules; alternative materials such as suction cups and magnet hooks; wig fixing materials; temporary materials such as book stands and book ends Fixed materials; Board-like teaching materials or toys for infants that can be attached and peeled off various objects; Board game pieces or boards; Document holders for re-sealing ((Registered Trademark) Velcro) and (Registered Trademark) Magic Fasteners And alternative materials such as a dust removal roller. The surface of the adherend is preferably smooth to such an extent that the adhesive strength of the temporary fixing material of the present invention can be sufficiently exerted.

  Hereinafter, although the present invention is explained based on an example, the present invention is not limited to these. The normal temperature means 23 ° C.

(Molecular weight measurement)
The weight average molecular weight was determined by GPC (gel permeation chromatography).
Equipment: “HLC-8020” manufactured by Tosoh Corporation
Column: “TSKgel GMH _HR- H (20)” manufactured by Tosoh Corporation
Solvent: Tetrahydrofuran Standard: Polystyrene

(Measurement of average pore diameter)
A sample for measurement was prepared by cutting the produced foam sheet in the thickness direction with a microtome cutter. The cut surface of the sample for measurement was photographed with a low vacuum scanning electron microscope (Hitachi, S-3400N) at a magnification of 800 to 5000 times. Using the obtained image, the major axis lengths of up to about 30 large-sized spherical bubbles, through holes and surface openings were measured, and the average value of the measured values was taken as the average pore diameter.

(180 ° bending test)
The produced foam was cut into 100 mm × 100 mm in the longitudinal direction (MD: Machine Direction) or transverse direction (TD: Transverse Direction) to obtain a measurement sample. After the end of the measurement sample was bent at about 50 mm and bent by 180 ° in the longitudinal direction, the ends were overlapped, and then moved back and forth from the overlapped end to the bending point with a 1 kg roller. The occurrence of cracks at the bending point was visually confirmed. Samples were measured at n = 3.

(Measurement of density of foam (or foam part))
Five pieces of the obtained foam (or foam part) were cut into a size of 100 mm × 100 mm to obtain test pieces, and the apparent density was determined by dividing the weight by the volume. The average value of the apparent density obtained was taken as the density of the foam (or foam part).

(Measurement of bubble rate)
Only the oil phase component at the time of producing the emulsion was polymerized, and the obtained polymer sheet was cut into five pieces of 100 mm × 100 mm to obtain test pieces, and the apparent density was obtained by dividing the weight by the volume. The average value of the apparent density obtained was taken as the density of the resin component constituting the foam (or foam part). The cell ratio of the foam (or foam part) was calculated by the following formula using the relative density obtained by dividing the density of the foam (or foam part) by the density of the resin component.
Bubble ratio = (1−relative density) × 100

(Measurement of normal shear adhesive strength)
The obtained foam or the like was cut into 20 mm × 20 mm, and BA plates (SUS304) were attached to both surfaces of the foam or the like. A 2 kg roller was reciprocated once to press the sample placed horizontally. After crimping, the sample was left at room temperature overnight, fixed to Tensilon so that the sample was vertical at room temperature, pulled at a pulling rate of 50 mm / min, and the shear adhesive force was measured. Samples were measured at n = 2, and the average value was defined as normal shear adhesive strength.

(Measurement of 180 ° peel test force)
The obtained foam or the like was cut into 25 mm × 100 mm, one of the separators was peeled off and attached to a BA plate (SUS304), and a 2 kg roller was reciprocated once for pressure bonding. After crimping, the sample was allowed to stand at room temperature for 30 minutes, peeled in the direction of 180 ° at a tensile speed of 50 mm / min using Tensilon, and the peel adhesive force was measured. Samples were measured at n = 2, and the average value was defined as a 180 ° peel test force. The 180 ° peel test force of the temporarily fixing material having the pressure-sensitive adhesive layer was measured by attaching the surface of the foam to a BA plate.

(Measurement of 60 ° C holding power)
The obtained foam or the like was cut into 10 mm × 100 mm, and one separator was peeled off and pasted on a baking plate so as to have a pasting area of 10 mm × 20 mm. After the pressure bonding, the baking plate was fixed so that the sample was vertical in an atmosphere of 60 ° C., and a load of 500 g was applied to one foam and left for 2 hours. After leaving, the amount of deviation of the sample application position after 2 hours was measured. In addition, the 60 degreeC retention strength of the temporarily fixed material which has an adhesive layer measured the surface by affixing a foam side on a bake board.

(Measurement of 50% compression strain recovery rate)
In the present invention, the 50% compression strain recovery rate (80 ° C. atmosphere, 50% compression set) of the temporarily fixed material or the like is determined by the method described below.
FIG. 5 is a diagram illustrating a method for measuring a 50% compression strain recovery rate. In FIGS. 5 (a), (b), and (c), 1, 2, and 3 represent a temporary fixing material, a spacer, and a plate, respectively. The temporary fixing material 1 uses a sheet having a thickness of about 1 mm as a sample. The thickness a of the sample was accurately measured so that the thickness b of the spacer 2 was half of a. As shown in FIG. 5A, the sample and the spacer 2 were placed between the two plates 3. A vertical pressure was applied to the plate 3, and the sample was compressed until the thickness of the sample was equal to the thickness b of the spacer 2, as shown in FIG. While maintaining this compressed state, it was stored in an atmosphere at 80 ° C. for 22 hours. After 22 hours, the temperature was returned to 23 ° C. while maintaining the compressed state. After the temporarily fixing material 1 returned to 23 ° C., the compressed state was released and left at 23 ° C. FIG. 5C shows a state after the compressed state is released. The sample thickness c was measured 30 minutes after the compression state was released. The value obtained by the following calculation formula (1) was defined as 50% compression strain recovery rate (at 80 ° C. atmosphere, 50% compression set).
Formula (1): 50% compression strain recovery rate (at 80 ° C. atmosphere, 50% compression set) (%) = [(c−b) / (a−b)] × 100

(Dimensional change rate when stored at 125 ° C for 22 hours)
The dimensional change in heating of the obtained foam or the like was measured according to JIS-K-6767 dimensional stability evaluation at high temperature. That is, the obtained foam or the like was cut into a size of 100 mm × 100 mm to obtain a test piece, which was stored in an oven at 125 ° C. for 22 hours, and then conformed to the dimensional stability evaluation at high temperature of JIS-K-6767. Thus, the dimensional change rate before and after the heat storage treatment was determined.

[Production Example 1]: Preparation of mixed syrup 1 In a reaction vessel equipped with a cooling tube, a thermometer, and a stirrer, 2-ethylhexyl acrylate (produced by Toagosei Co., Ltd., hereinafter abbreviated as “2EHA”) as an ethylenically unsaturated monomer 173.2 parts by weight of a monomer solution, 100 parts by weight of Adeka (registered trademark) Pluronic L-62 (molecular weight 2500, manufactured by ADEKA Corporation, polyether polyol) as a polyoxyethylene polyoxypropylene glycol, and urethane reaction Dibutyltin dilaurate (manufactured by Kishida Chemical Co., Ltd., hereinafter abbreviated as “DBTL”) as a catalyst was added in an amount of 0.014 part by weight, and while stirring, hydrogenated xylylene diisocyanate (Takeda Pharmaceutical Co., Ltd., Takenate 600, (Hereinafter abbreviated as “HXDI”) 12.4 parts by weight were added dropwise and reacted at 65 ° C. for 4 hours. . In addition, the usage-amount of the polyisocyanate component and the polyol component was NCO / OH (equivalent ratio) = 1.6. Thereafter, 5.6 parts by weight of 2-hydroxyethyl acrylate (manufactured by Kishida Chemical Co., Ltd., hereinafter abbreviated as “HEA”) is dropped and reacted at 65 ° C. for 2 hours, and a hydrophilic polyurethane system having acryloyl groups at both ends. A polymer / ethylenically unsaturated monomer mixed syrup was obtained. The weight average molecular weight of the obtained hydrophilic polyurethane polymer having acryloyl groups at both ends was 15,000. 27.3 parts by weight of 2EHA, n-butyl acrylate (manufactured by Toagosei Co., Ltd., hereinafter abbreviated as “BA”) with respect to 100 parts by weight of the obtained hydrophilic polyurethane polymer / ethylenically unsaturated monomer mixed syrup 51. 8 parts by weight, 17.6 parts by weight of isobornyl acrylate (for example, Osaka Organic Chemical Industries, Ltd., hereinafter abbreviated as “IBXA”), acrylic acid as a polar monomer (for example, manufactured by Toa Gosei Co., Ltd., hereinafter “AA”) 10.5 parts by weight) was added to obtain a hydrophilic polyurethane polymer / ethylenically unsaturated monomer mixed syrup 1.

[Production Example 2]: Preparation of mixed syrup 2 In a reaction vessel equipped with a condenser, a thermometer, and a stirrer, 173.2 parts by weight of a monomer solution composed of 2EHA as an ethylenically unsaturated monomer, and polyoxyethylene polyoxy While adding 100 parts by weight of Adeka (registered trademark) Pluronic L-62 (molecular weight 2500, manufactured by ADEKA, polyether polyol) as propylene glycol and 0.014 parts by weight of DBTL as a urethane reaction catalyst, while stirring. 12.4 parts by weight of HXDI was added dropwise and reacted at 65 ° C. for 4 hours. In addition, the usage-amount of the polyisocyanate component and the polyol component was NCO / OH (equivalent ratio) = 1.6. Then, 5.6 parts by weight of HEA was added dropwise and reacted at 65 ° C. for 2 hours to obtain a hydrophilic polyurethane polymer / ethylenically unsaturated monomer mixed syrup having acryloyl groups at both ends. The weight average molecular weight of the obtained hydrophilic polyurethane polymer having acryloyl groups at both ends was 15,000. 95.8 parts by weight of 2EHA, 92.5 parts by weight of BA, 31.3 parts by weight of IBXA, and 31.3 parts by weight of polar monomer based on 100 parts by weight of the obtained hydrophilic polyurethane polymer / ethylenically unsaturated monomer mixed syrup 18.8 parts by weight of AA was added to obtain a hydrophilic polyurethane polymer / ethylenically unsaturated monomer mixed syrup 2.

[Production Example 3]: Preparation of mixed syrup 3 In a reaction vessel equipped with a condenser, a thermometer, and a stirrer, 173.2 parts by weight of a monomer solution composed of 2EHA as an ethylenically unsaturated monomer, and polyoxyethylene polyoxy While adding 100 parts by weight of Adeka (registered trademark) Pluronic L-62 (molecular weight 2500, manufactured by ADEKA, polyether polyol) as propylene glycol and 0.014 parts by weight of DBTL as a urethane reaction catalyst, while stirring. 12.4 parts by weight of HXDI was added dropwise and reacted at 65 ° C. for 4 hours. In addition, the usage-amount of the polyisocyanate component and the polyol component was NCO / OH (equivalent ratio) = 1.6. Then, 5.6 parts by weight of HEA was added dropwise and reacted at 65 ° C. for 2 hours to obtain a hydrophilic polyurethane polymer / ethylenically unsaturated monomer mixed syrup having acryloyl groups at both ends. The weight average molecular weight of the obtained hydrophilic polyurethane polymer having acryloyl groups at both ends was 15,000. 24.7 parts by weight of 2EHA, 41.9 parts by weight of BA, and 4-hydroxybutyl acrylate (Toagosei Co., Ltd.) as polar monomers with respect to 100 parts by weight of the resulting hydrophilic polyurethane polymer / ethylenically unsaturated monomer mixed syrup (Hereinafter, abbreviated as “4HBA”) was added to 8.5 parts by weight to obtain a hydrophilic polyurethane polymer / ethylenically unsaturated monomer mixed syrup 3.

[Example 1]
To 100 parts by weight of the hydrophilic polyurethane polymer / ethylenically unsaturated monomer mixed syrup 1 obtained in Production Example 1, 1,6-hexanediol diacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., trade name “NK Ester A” -HD-N ") (molecular weight 226) 11.9 parts by weight, synthesized as a reactive oligomer from polytetramethylene glycol (hereinafter abbreviated as" PTMG ") and isophorone diisocyanate (hereinafter abbreviated as" IPDI "). 47.7 parts by weight of urethane acrylate having both ends of polyurethane treated with HEA and having ethylenically unsaturated groups at both ends (hereinafter abbreviated as “UA”) (molecular weight 3720) as a photoinitiator, 2,4,6-trimethylbenzoyl) phosphine oxide (BASF, trade name “Lucirin TPO”) 8 parts by weight, 0.95 parts by weight of hindered phenol antioxidant (Ciba Japan, trade name “Irganox 1010”), 2 parts by weight of light stabilizer (for example, BASF, trade name: TINUVIN 123) The parts were uniformly mixed to obtain a continuous oil phase component (hereinafter referred to as “oil phase”). On the other hand, 300 parts by weight of ion-exchanged water as an aqueous phase component (hereinafter referred to as “aqueous phase”) with respect to 100 parts by weight of the oil phase is continuously introduced into a stirring mixer that is an emulsifier charged with the oil phase at room temperature. Were added dropwise to prepare a stable W / O emulsion. The weight ratio of the water phase to the oil phase was 75/25.
The foamed layer after light irradiation was prepared on a polyethylene terephthalate film (hereinafter referred to as “PET film”) having a thickness of 38 μm, and a W / O emulsion that had been stored at room temperature for 30 minutes by standing. The film was applied so as to have a thickness of 150 μm and continuously formed into a sheet shape. Furthermore, a 50 μm thick polyester fiber laminated fabric (manufactured by JX Nippon Mining & Chemicals, Inc., trade name “MILIFE (registered trademark) TY0503FE”) in which stretched polyester long fibers were laminated in a vertical arrangement was laminated. . Further, separately from the preparation, the W / O type emulsion, which was stored at room temperature for 30 minutes, was placed on a PET film having a thickness of 38 μm, and the foamed layer after light irradiation had a thickness of 150 μm. A coated material was prepared, and the coated surface was covered with the polyester fiber laminated fabric. This sheet was irradiated with ultraviolet light having a light illuminance of 5 mW / cm ² (measured with Topcon UVR-T1 having a maximum peak sensitivity wavelength of 350 nm) using black light (15 W / cm) to obtain a highly hydrous crosslinked polymer having a thickness of 310 μm. . Next, the top film was peeled off, and the high water content crosslinked polymer was heated at 130 ° C. for 10 minutes to obtain a temporary fixing sheet (1) having a thickness of about 0.3 mm.
Table 1 shows the evaluation results of the temporarily fixed sheet (1) obtained.
In addition, the temporary fixing sheet (1) was not cracked in a 180 ° bending test.
Moreover, the photograph figure of the surface / cross-section SEM photograph which image | photographed the produced temporarily fixing sheet from diagonally was shown in FIG.

  When the four corners of a calendar made of A3 size paper were pressed against the window glass through the temporary fixing sheet (1) cut to a size of 3 cm × 3 cm, the calendar could be fixed. Moreover, the calendar could be easily peeled from the temporarily fixed sheet (1), and the temporarily fixed sheet (1) could also be easily peeled from the window glass. Even when this operation was repeated 20 times, no decrease in adhesiveness and breakage of the sheet were observed.

[Example 2]
To 100 parts by weight of the hydrophilic polyurethane polymer / ethylenically unsaturated monomer mixed syrup 2 obtained in Production Example 2, 1,6-hexanediol diacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., trade name “NK Ester A” -HD-N ") (molecular weight 226) 10.0 parts by weight, as reactive oligomer, UA (molecular weight 3720) 47.7 parts by weight, photoinitiator, lucillin TPO 0.49 parts by weight, hindered phenol Irganox 1010 was 0.99 parts by weight as a system antioxidant, and 2.05 parts by weight of TINUVIN 123 as a light stabilizer was uniformly mixed to obtain a continuous oil phase component (hereinafter referred to as “oil phase”). On the other hand, 186 parts by weight of ion-exchanged water as an aqueous phase component (hereinafter referred to as “aqueous phase”) with respect to 100 parts by weight of the oil phase is continuously placed in a stirring mixer which is an emulsifier charged with the oil phase at room temperature. Were added dropwise to prepare a stable W / O emulsion. The weight ratio of the water phase to the oil phase was 65/35.
Next, a temporary fixing sheet (2) having a thickness of about 0.3 mm was obtained by the same operation as in Example 1.
Table 1 shows the evaluation results of the temporarily fixed sheet (2) obtained.
The temporary fixing sheet (2) did not crack in the 180 ° bending test.

  When the four corners of an acrylic board (Mitsubishi Rayon Co., Ltd. acrylite board; 200 mm x 300 mm x 2 mm) are pressed against a metal door via the temporary fixing sheet (2) cut into 1 cm x 1 cm dimensions The acrylic plate could be fixed. Moreover, the acrylic board could be easily peeled from the temporarily fixing sheet (2), and the temporarily fixing sheet (2) could also be easily peeled from the door. Even when this operation was repeated 20 times, no decrease in adhesiveness and breakage of the sheet were observed.

[Example 3]
To 100 parts by weight of the hydrophilic polyurethane polymer / ethylenically unsaturated monomer mixed syrup 3 obtained in Production Example 3, 1,6-hexanediol diacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., trade name “NK Ester A” -HD-N ") (molecular weight 226) 20 parts by weight, as reactive oligomer, UA (molecular weight 3720) 47.7 parts by weight, photoinitiator, lucillin TPO 0.49 parts by weight, hindered phenol oxidation Irganox 1010 as an inhibitor, 0.99 parts by weight, and TINUVIN 123 as a light stabilizer, 2.05 parts by weight, were uniformly mixed to obtain a continuous oil phase component (hereinafter referred to as “oil phase”). On the other hand, with respect to 100 parts by weight of the oil phase, 567 parts by weight of ion-exchanged water as an aqueous phase component (hereinafter referred to as “aqueous phase”) is continuously added in a stirring mixer which is an emulsifier charged with the oil phase at room temperature. Were added dropwise to prepare a stable W / O emulsion. The weight ratio of the water phase to the oil phase was 85/15.
Next, a temporary fixing sheet (3) having a thickness of about 0.4 mm was obtained by the same operation as in Example 1.
Table 1 shows the evaluation results of the temporarily fixed sheet (3) obtained.
In addition, the temporary fixing sheet (3) did not generate cracks in the 180 ° bending test.

  When a SUS304 plate (100 mm × 49 mm × 5 mm; 180 g) was pressed against the resin display board through the temporary fixing sheet (3) cut into the same dimensions, the SUS plate could be fixed. Further, the SUS plate could be easily peeled off from the temporary fixing sheet (3), and the temporary fixing sheet (3) could also be easily peeled off from the display board. Even when this operation was repeated 20 times, no decrease in adhesiveness and breakage of the sheet were observed.

[Example 4]
The thickness of the foamed layer after light irradiation on the 50 μm-thick polyethylene terephthalate film (hereinafter referred to as “PET film”) obtained by releasing the stable W / O emulsion obtained in Example 1 Was applied to a thickness of 300 μm, and a PET film having a thickness of 38 μm that had been subjected to a mold release treatment was placed thereon. This sheet was irradiated with ultraviolet rays having a light illuminance of 5 mW / cm ² (measured with Topcon UVR-T1 having a maximum peak sensitivity wavelength of 350 nm) using a chemical lamp (15 W / cm) to obtain a highly hydrous crosslinked polymer having a thickness of 300 μm. . Next, the top film was peeled off, and the high water content crosslinked polymer was heated at 130 ° C. for 10 minutes to obtain a foam having a thickness of about 0.3 mm. Next, a double-sided tape (made by Nitto Denko Corporation, trade name “No. 5603” having a configuration of [adhesive layer / support (PET film) / adhesive layer] as an adhesive layer on one side of the obtained foam. ]) Was laminated | stacked and the temporarily fixed sheet | seat (4) was obtained. The temporary fixing sheet (4) did not crack in the 180 ° bending test.
Each evaluation result of the temporarily fixed sheet (4) obtained is shown in Table 2. In addition, the measuring method of 90 degree peel test force is as follows.

(Measurement of 90 ° peel test force)
The temporary fixing sheet (4) was pasted and fixed on one side of a 110 mm × 80 mm × 5 mm SUS304 plate so that the pressure-sensitive adhesive layer surface was in contact with the SUS304 plate. A 50 μm thick PET film (trade name “Lumirror S10 # 50”) cut to a size of 50 mm × 150 mm is pressure-bonded to the foam surface of the temporarily fixed sheet (4) with a 2 kg roller, and stored at room temperature for 30 minutes. did. Then, it peeled in the direction of 90 degree | times with the tensile speed of 300 mm / min using Tensilon, and the peeling adhesive force in the middle was measured. Samples were measured at n = 3, and the average value was taken as 90 ° peel test force.

  The temporary fixing material of the present invention is a temporary fixing material or temporary temporary material for displaying or displaying advertisements, calendars, drawings, memos, photographs, various products (for example, portable electronic devices such as mobile phones and portable game machines) and the like. Fixed board: Temporary fixing material for temporarily fixing cards, coins, touch pens, accessories, etc. to mobile phones, etc .; Temporary fixing material for placing small items such as coins, glasses, mobile phones, accessories, etc. on the dashboard of an automobile Or a temporary fixing board; a light shielding sheet in a vehicle; a temporary fixing material that is laminated on a wireless transmission charging device and temporarily fixes a charging target on the device; a processing material such as a semiconductor material or a color filter; a circuit board, a thin film glass module, etc. Carrier sheets; alternative materials such as suction cups and magnet hooks; wig fixing materials; temporary fixing materials such as book stands and book ends; Removable board-shaped educational materials or toys for infants; Board game pieces or boards; Alternative materials such as re-sealing document holders ((registered trademark) Velcro) and (registered trademark) magic fasteners; It can be suitably applied to.

DESCRIPTION OF SYMBOLS 100 Temporary fixing material 10 Foam 20 Base material 30 Release film 40 Adhesive layer 41 Support body

Claims (7)

A temporary fixing material comprising a foam having an open cell structure having a through-hole between adjacent spherical bubbles,
The average pore size of the spherical bubbles is less than 20 μm,
The average pore diameter of the through holes is 5 μm or less,
The surface has a surface opening with an average pore diameter of 20 μm or less on the surface,
The normal shear adhesive strength is 1 N / cm ² or more,
Temporary fixing material.   The temporarily fixed material of Claim 1 whose 180 degree peel test force is 1 N / 25mm or less.   The temporarily fixed material of Claim 1 or 2 whose 60 degreeC retention strength is 0.5 mm or less.   The 50% compression strain recovery rate is 70% or more after 30 minutes of storage at 80 ° C in a 50% compression state and then cooling to 23 ° C and then 30 minutes after releasing the compression state. To temporary fixing material according to any one of items 3 to 3.   The temporary fixing material according to any one of claims 1 to 4, wherein a dimensional change rate when stored at 125 ° C for 22 hours is less than ± 5%. Wherein the foam has a density in the ^{0.15g / cm 3 ~0.6g / cm 3} , the temporary fixing material according to any one of claims 1 to 5.   The temporary fixing material according to any one of claims 1 to 6, wherein a foam ratio of the foam is 30% or more.