JP2008133482A - Water-dispersed self-adhesive composition, self-adhesive sheet, and self-adhesive foamed rubber sheet using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a water-dispersed self-adhesive composition which is excellent in adhesion to a foamed material and releasability in a terminal area and shows a stable adhesion force over time, and to provide a self-adhesive sheet obtained by forming a self-adhesive layer comprising the composition on a base material and a self-adhesive foamed rubber sheet obtained by forming the layer on one or both sides of a foamed rubber. <P>SOLUTION: The water-dispersed self-adhesive composition is obtained by adding a tackifier to a polymer, wherein the polymer is obtained by copolymerizing a monomer mixture containing an alkyl (meth)acrylate as an essential component and further containing a silane monomer, and the tackifier contains a phenol skeleton. The self-adhesive sheet and the self-adhesive foamed rubber sheet are each obtained by using the composition. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a water-dispersed pressure-sensitive adhesive composition, a pressure-sensitive adhesive sheet (including forms such as tape, sheet, and film) provided on a base material, and rubber provided with these on one or both sides of a rubber foam. The present invention relates to a foam adhesive sheet.

  Conventionally, rubber foams are used for various purposes such as architectural civil engineering, electrical equipment, housing equipment, and members of ships, vehicles, automobiles, etc. for the purpose of dustproofing, heat insulation, soundproofing, vibration proofing, buffering, watertightness and airtightness. Are widely used as sealing materials for filling gaps. In recent years, it has been widely used in the field of information equipment such as personal computers, mobile phones, and PDAs.

  These rubber foams are vulcanized by adding a vulcanizing agent and a blowing agent to a rubber-based polymer such as EPDM (ethylene / propylene / diene rubber), which has excellent weather resistance, cold resistance, heat resistance, chemical resistance, etc. It is foamed and has an adhesive layer attached to facilitate construction.

  Conventionally, the pressure-sensitive adhesive composition used for this purpose is mainly a solvent-type pressure-sensitive adhesive composition in which an acrylic or rubber-based polymer is dissolved in an organic solvent. However, from the viewpoint of environmental problems in recent years and hygiene problems in the working environment, it is desired to switch to a solvent-free type.

  A pressure-sensitive adhesive sheet using a water-dispersed pressure-sensitive adhesive composition, which is a solvent-free type, does not use an organic solvent, and therefore has advantages such as desirable environmental hygiene and excellent solvent resistance. However, such a water-dispersed pressure-sensitive adhesive sheet is difficult to achieve both adhesion and retainability to an adherend (particularly a rough surface such as a foam) as compared with a solvent-type pressure-sensitive adhesive sheet, It had the disadvantage of being inferior in practical properties.

  The present inventors have intensively studied to solve the above problems, and in a monomer mixture mainly composed of water-dispersed (meth) acrylic acid alkyl ester, a silane monomer and, if necessary, a chain. It has been found that, when a transfer agent is added and polymerized, both adhesion and retention to an adherend can be achieved at a high level, and practical properties (such as terminal peelability) equivalent to those of a solvent-type pressure-sensitive adhesive can be obtained ( Patent Document 1).

  However, even with the above-mentioned pressure-sensitive adhesive, it is difficult to obtain a satisfactory adhesive force with respect to the rubber foam. Further, depending on the type of the rubber foam, the adhesiveness may deteriorate with time. This decrease in adhesiveness over time is a phenomenon that is observed not only when the foam is used as an adherend but also when the foam is a foam-based adhesive sheet.

JP 2001-131511 A

  An object of the present invention is to provide a water-dispersed pressure-sensitive adhesive composition having excellent adhesiveness to foam and terminal peeling performance and having stable adhesive force over time. The present invention also provides a pressure-sensitive adhesive sheet provided with a pressure-sensitive adhesive layer comprising the water-dispersed pressure-sensitive adhesive composition on a base material, and a rubber foam pressure-sensitive adhesive sheet in which these are provided on one side or both sides of a rubber foam. It is aimed.

  As a result of intensive studies on the above problems, the inventors of the present invention have decreased adhesiveness over time because the nonpolar components (paraffin oil, asphalt, etc.) of the rubber foam are transferred to the pressure-sensitive adhesive layer. By finding that, by adding a tackifier containing a phenol skeleton to a polymer obtained by copolymerizing a silane monomer in a monomer mixture mainly composed of water-dispersed (meth) acrylic acid ester, It has been found that a non-polar component of a rubber foam can be prevented from being transferred, a pressure-sensitive adhesive having excellent adhesion to rubber foam and terminal peeling performance, and excellent adhesion stability over time can be obtained. The present invention has been completed.

  The reason why an excellent effect by adding a tackifier containing a phenol skeleton to the pressure-sensitive adhesive composition is not clear, but when the pressure-sensitive adhesive is low, the non-polarity of the rubber foam The component easily migrates to the pressure-sensitive adhesive layer and causes a decrease in adhesive strength over time. However, when the polarity is high, the migration of the component is suppressed, and it is considered that the adhesive strength does not decrease. Specifically, when a polymerized rosin ester having a low polarity is added as a tackifier, a decrease in adhesiveness is observed, whereas when a highly polar rosin phenol or terpene phenol is added, the adhesiveness is decreased. Since it is suppressed, it is guessed that the phenol skeleton in the tackifier molecule acts effectively.

  That is, the present invention relates to an adhesive containing a phenol skeleton in an aqueous dispersion of a polymer obtained by copolymerizing a monomer mixture containing a (meth) acrylic acid alkyl ester as a main component and containing a silane monomer. A water-dispersed pressure-sensitive adhesive composition obtained by adding an imparting agent (Claim 1), in particular, polymerized with a composition containing (meth) acrylic acid alkyl ester as a main component and no silane monomer. A monomer mixture that gives a resin composition having a solvent insoluble content of 5% or less, and 0.005 to 1 part by weight of a silane monomer with respect to 100 parts by weight of the monomer mixture. It is a polymer obtained by copolymerization under the same conditions as described above, and relates to the water-dispersed pressure-sensitive adhesive composition (claim 2).

  The present invention also provides the above water-dispersed pressure-sensitive adhesive composition, which is a polymer obtained by copolymerizing a monomer mixture containing (meth) acrylic acid alkyl ester as a main component and containing a silane monomer. The present invention relates to a water-dispersed pressure-sensitive adhesive composition (Claim 3) obtained by adding 0.005 to 1 part by weight of an organic compound capable of binding to a silane monomer to 100 parts by weight, particularly the silane-based single monomer. The organic compound that can bind to the body is a water-dispersed pressure-sensitive adhesive composition (claim 4), which is a silane compound.

  The present invention also relates to the water-dispersed pressure-sensitive adhesive composition, wherein the silane-based monomer is a methoxysilane-based monomer (claim 5), and the polymer It relates to a water-dispersed pressure-sensitive adhesive composition (claim 6), characterized in that methacrylic acid is copolymerized therein.

  The present invention also relates to a water-dispersed pressure-sensitive adhesive composition (claim 7), wherein the tackifier is a rosin phenol-based or terpene phenol-based tackifier.

  The present invention also relates to a pressure-sensitive adhesive sheet in which a pressure-sensitive adhesive layer comprising the water-dispersed pressure-sensitive adhesive composition is provided on one side (Claim 8) or both sides (Claim 9).

  The present invention also provides a rubber foam pressure-sensitive adhesive sheet (Claim 10), wherein the pressure-sensitive adhesive layer comprising the water-dispersed pressure-sensitive adhesive composition is provided on one or both sides of the rubber foam, and the pressure-sensitive adhesive sheet. The present invention relates to a rubber foam pressure-sensitive adhesive sheet (Claim 11) provided on one or both sides of a rubber foam.

In the present specification, “solvent insoluble matter” means that a predetermined amount (about 500 mg) of a sample is precisely weighed (of which the weight of non-volatile matter is W ₁ mg), and this is placed in ethyl acetate at room temperature. After soaking for days, the insoluble matter was taken out, this insoluble matter was dried at 100 ° C. for 2 hours, and the weight (W ₂ mg) was measured. The following formula solvent-insoluble matter (wt%) = (W ₂ / W ₁ ) × It is calculated according to 100.

  Since the water-dispersed pressure-sensitive adhesive composition of the present invention uses a water-dispersed acrylic pressure-sensitive adhesive, it is desirable for environmental hygiene. The pressure-sensitive adhesive sheet and the rubber foam pressure-sensitive adhesive sheet provided on the base material are excellent rubber foams. Adhesive properties with excellent adhesion stability over time and excellent adhesion stability over time.

  The present invention provides an aqueous dispersion of a polymer obtained by copolymerizing a monomer mixture containing (meth) acrylic acid alkyl ester as a main component and containing a silane monomer, and containing a phenol skeleton. A water-dispersed pressure-sensitive adhesive composition obtained by adding an agent is provided.

The (meth) acrylic acid alkyl ester used as the main constituent monomer in the present invention is represented by the general formula (1).
CH ₂ = C (R ₁ ) COOR ₂ (1)
(Wherein R ₁ represents a hydrogen atom or a methyl group, and R ₂ represents an alkyl group having 2 to 14 carbon atoms).

Examples of R ₂ include an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, an isoamyl group, a hexyl group, a heptyl group, a 2-ethylhexyl group, an isooctyl group, an isononyl group, and an isodecyl group. Among these, R ₂ is preferably an alkyl group having 2 to 10 carbon atoms such as a butyl group or a 2-ethylhexyl group. The said (meth) acrylic-acid alkylester can be used individually or in mixture of 2 or more types. For example, butyl acrylate alone or a combination of butyl acrylate and 2-ethylhexyl acrylate can be used as the alkyl acrylate ester. In this case, the ratio of 2-ethylhexyl acrylate to butyl acrylate is about the former / the latter = 0/100 to 55/45 (for example, 5/95 to 60/40).

The proportion of the (meth) acrylic acid alkyl ester [for example, the above (meth) acrylic acid C _2-14 alkyl ester] in the monomer mixture mainly composed of (meth) acrylic acid alkyl ester is generally 80% by weight. It is more than (for example, about 80 to 99.8% by weight), preferably 85% by weight or more (for example, about 85 to 99.5% by weight), and more preferably 90% by weight or more (for example, about 90 to 99% by weight).

  The monomer mixture usually contains a functional group-containing monomer (thermally crosslinkable functional group-containing monomer) in order to introduce a crosslinking point for thermal crosslinking. By using the functional group-containing monomer as a comonomer component, adhesion to an adherend is also improved.

  Examples of the functional group-containing monomer include carboxyl group-containing monomers such as acrylic acid, methacrylic acid, itaconic acid, maleic acid, crotonic acid, and maleic anhydride, or acid anhydrides thereof; (meth) acrylic acid 2 Hydroxyl group-containing monomers such as hydroxyethyl, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate; (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N-methylol ( Amide group-containing monomers such as (meth) acrylamide, N-methoxymethyl (meth) acrylamide, N-butoxymethyl (meth) acrylamide; dimethylaminoethyl (meth) acrylate, t-butylaminoethyl (meth) acrylate, etc. Amino group-containing monomers; glycidyl such as glycidyl (meth) acrylate Containing monomers; (meth) acrylonitrile, N- (meth) acryloyl morpholine, N- vinyl-2-pyrrolidone. Among these, carboxyl group-containing monomers such as acrylic acid or acid anhydrides thereof are preferable. One or more of the above functional group-containing monomers can be used.

  The usage-amount of the said functional group containing monomer is 0.5-12 weight part with respect to 100 weight part of said (meth) acrylic-acid alkylesters, Preferably it is about 1-8 weight part.

  Moreover, in order to improve characteristics, such as cohesion force, the said monomer mixture may contain the other copolymerizable monomer as needed. Examples of such copolymerizable monomers include vinyl esters such as methyl (meth) acrylate and vinyl acetate; aromatic vinyl compounds such as styrene and vinyl toluene; cyclopentyl di (meth) acrylate, isobornyl (meta ) (Meth) acrylic esters of cyclic alcohols such as acrylate; neopentyl glycol di (meth) acrylate, hexanediol di (meth) acrylate, propylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, And (meth) acrylic acid esters of polyhydric alcohols such as tetramethylol methane tri (meth) acrylate and dipentaerythritol hexa (meth) acrylate. These copolymerizable monomers can also be used alone or in combination of two or more.

  In the present invention, the silane monomer copolymerized with the (meth) acrylic acid alkyl ester is not particularly limited as long as it is a polymerizable compound having a silicon atom. A silane compound having a (meth) acryloyl group such as a (meth) acryloyloxyalkylsilane derivative is preferable in terms of excellent polymerizability. Examples of the silane monomer include 3-methacryloyloxypropyltrimethoxysilane, 3-acryloyloxypropyltrimethoxysilane, 3-methacryloyloxypropyltriethoxysilane, 3-acryloyloxypropyltriethoxysilane, and 3-methacryloyloxy. Examples include propylmethyldimethoxysilane, 3-acryloyloxypropylmethyldimethoxysilane, 3-methacryloyloxypropylmethyldiethoxysilane, and 3-acryloyloxypropylmethyldiethoxysilane. These silane monomers can be used alone or in combination of two or more.

  In addition to the above, as copolymerizable silane monomers, for example, vinyltrimethoxysilane, vinyltriethoxysilane, 4-vinylbutyltrimethoxysilane, 4-vinylbutyltriethoxysilane, 8-vinyloctyltri Methoxysilane, 8-vinyloctyltriethoxysilane, 10-methacryloyloxydecyltrimethoxysilane, 10-acryloyloxydecyltrimethoxysilane, 10-methacryloyloxydecyltriethoxysilane, 10-acryloyloxydecyltriethoxysilane and the like can also be used. .

  The amount of the silane monomer can be appropriately selected according to the kind and use of the (meth) acrylic acid alkyl ester, but the copolymerization amount of the silane monomer is mainly composed of the (meth) acrylic acid alkyl ester. For 100 parts by weight of the monomer mixture (excluding silane monomers) as the component, the adhesive strength may be reduced to the extent that it cannot be adhered if it exceeds 1 part by weight. Cohesive force tends to decrease due to insufficient polymer strength. Therefore, in the present invention, the amount of the silane monomer relative to 100 parts by weight of the monomer mixture (excluding the silane monomer) is preferably 0.005 to 1 part by weight, more preferably 0.01 to The range is 0.5 parts by weight.

  For example, the polymer constituting the water-dispersed pressure-sensitive adhesive composition of the present invention is obtained by subjecting a monomer mixture containing the above (meth) acrylic acid alkyl ester as a main component and a silane monomer to conventional emulsion polymerization. Then, it can be prepared as an aqueous dispersion of a (meth) acrylic acid ester copolymer.

  In the water-dispersed pressure-sensitive adhesive composition of the present invention, in particular, when polymerized with a composition containing (meth) acrylic acid alkyl ester as a main component and no silane monomer, the solvent-insoluble content is 5% or less. A monomer mixture obtained from the resin composition, and 0.005 to 1 part by weight of a silane monomer with respect to 100 parts by weight of the monomer mixture, the composition not containing the silane monomer In the water-dispersed pressure-sensitive adhesive composition containing a polymer obtained by polymerizing under the same conditions as when polymerized in the above, excellent terminal peelability and high retainability, despite being water-dispersed It is possible to achieve both.

  The above "same conditions" refers to other polymerization conditions excluding the presence or absence of silane monomers, such as reaction temperature, reaction time, type and amount of polymerization initiator, type and amount of chain transfer agent, etc. Means the same.

  In addition, when polymerizing a monomer mixture and a silane monomer, which gives a resin composition having a solvent insoluble content exceeding 5% when polymerized with a composition not containing a silane monomer, a terminal is used. Peelability tends to decrease.

  As a method of emulsion polymerization that can be used in the present invention, general batch polymerization, continuous dropping polymerization, divided dropping polymerization and the like can be employed, and the polymerization temperature is, for example, about 20 to 100 ° C.

  Examples of the polymerization initiator used for the polymerization include 2,2′-azobisisobutyronitrile, 2,2′-azobis (2-methylpropionamidine) disulfate, 2,2′-azobis (2-amidino). Propane) dihydrochloride, 2,2'-azobis [2- (5-methyl-2-imidazolin-2-yl) propane] dihydrochloride, 2,2'-azobis (N, N'-dimethyleneisobutylamidine), etc. Azo initiators; persulfates such as potassium persulfate and ammonium persulfate; peroxide initiators such as benzoyl peroxide, t-butyl hydroperoxide and hydrogen peroxide; substituted ethane initiators such as phenyl substituted ethane Agent; aromatic carbonyl compound; combination of persulfate and sodium bisulfite, peroxide and sodium ascorbate And redox initiators such as combinations with but are exemplified, but the invention is not limited thereto. The usage-amount of a polymerization initiator is about 0.005-1 weight part with respect to 100 weight part of total amounts of a monomer mixture, for example.

  Moreover, you may use a chain transfer agent for superposition | polymerization. Examples of chain transfer agents include conventional chain transfer agents such as mercaptans such as dodecanethiol. The amount of the chain transfer agent used is, for example, about 0.001 to 0.5 parts by weight with respect to 100 parts by weight of the total amount of the monomer mixture.

  In addition, as an emulsifier, anionic emulsifiers such as sodium lauryl sulfate, ammonium lauryl sulfate, sodium dodecylbenzenesulfonate, sodium polyoxyethylene alkyl ether sulfate, ammonium polyoxyethylene alkyl phenyl ether sulfate, sodium polyoxyethylene alkyl phenyl ether sulfate; polyoxy Nonionic emulsifiers such as ethylene alkyl ether and polyoxyethylene alkyl phenyl ether can be used. These emulsifiers may be used independently and may use 2 or more types together. The usage-amount of an emulsifier is 0.2-10 weight part with respect to 100 weight part of total amounts of a monomer mixture, Preferably it is about 0.5-5 weight part.

  The water-dispersed pressure-sensitive adhesive composition of the present invention is obtained by dispersing the above (meth) acrylic acid ester copolymer in water by using an emulsifier after obtaining the above (meth) acrylic acid ester copolymer by a method other than emulsion polymerization. An aqueous dispersion may be prepared.

  The water-dispersed pressure-sensitive adhesive composition of the present invention contains the above silane monomer in order to prevent heavy release over time with respect to a release liner or back treatment layer coated with a silicone release agent (meta ) You may add the organic compound which can be couple | bonded with a silane monomer to the aqueous dispersion of an acrylate ester copolymer. An organic compound capable of binding to a silane monomer can react with and bond to a Si—OH group generated by hydrolysis of a Si—OR group (R is an alkyl group such as methyl or ethyl) of the silane monomer. Although it will not specifically limit if it has an active group (for example, a hydroxyl group or a carboxyl group), A silane compound with favorable reactivity with a silane monomer is desirable.

  Examples of the silane compound include compounds having a Si—H group, a Si—OH group, and a Si—OR group (R is an alkyl group such as methyl or ethyl) in the molecule, such as methyltrimethoxysilane and butyltrimethoxy. Silane, dodecyltrimethoxysilane, hexadecyltrimethoxysilane, octadecyldimethylmethoxysilane, dimethoxydimethylsilane, methoxytrimethylsilane, diethoxydimethylsilane, methyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, dimethoxydiphenylsilane, Examples thereof include diphenylethoxymethylsilane, dimethoxymethylphenylsilane, triethylsilane, tripropylsilane, trimethylsilanol, triethylsilanol and the like.

  The silane compound preferably has no functional group that reacts with the polymer, but any functional group that does not significantly react can be used. Examples of the silane compound having such a functional group include (meth) acrylic acid-based silane compounds such as 3-methacryloyloxypropyltrimethoxysilane and 3-acryloyloxypropyltrimethoxysilane, and dimethoxy-3-mercaptopropylmethylsilane. , 3-mercaptopropyltrimethoxysilane and the like. These silane compounds may be used alone or in combination of two or more.

  When the amount of the organic compound capable of binding to the silane monomer is less than 0.005 parts by weight with respect to 100 parts by weight of the polymer having the (meth) acrylic acid alkyl ester as a main component, heavy peeling cannot be prevented. There is. When the amount exceeds 1 part by weight, the cohesive force may be reduced or the adherend may be contaminated. Further, when an organic compound that can be combined with a polyfunctional silane monomer is used, peeling may occur. May be heavy. This is presumed to function as a crosslinking agent when an unreacted organic compound is present. Therefore, in the present invention, the amount of the organic compound that can be combined with the silane monomer relative to 100 parts by weight of the polymer is preferably 0.005 to 1 part by weight, more preferably 0.01 to 0.5 part by weight. Range.

  Further, in the present invention, in order to prevent heavy release over time with respect to the release liner or back treatment layer coated with the silicone release agent, the main component is (meth) acrylic acid alkyl ester, and the silane type single amount. In the polymer obtained by copolymerizing the monomer mixture containing the silane monomer, the Si-OR group of the silane monomer is used as the silane monomer copolymerized with the above (meth) acrylic acid alkyl ester. It is preferable to use a methoxysilane monomer in which R is a methyl group. Examples of the methoxysilane monomer include 3-methacryloyloxypropyltrimethoxysilane, 3-acryloyloxypropyltrimethoxysilane, 3-methacryloyloxypropylmethyldimethoxysilane, 3-acryloyloxypropylmethyldimethoxysilane, and vinyltrimethoxysilane. 4-vinylbutyltrimethoxysilane, 8-vinyloctyltrimethoxysilane, 10-methacryloyloxydecyltrimethoxysilane, 10-acryloyloxydecyltrimethoxysilane, and the like.

  When a methoxysilane monomer is used, the hydrolysis rate of the methoxysilane monomer is high, and most of the methoxy groups are hydrolyzed to silanol groups during polymerization, so that they are incorporated into the polymer during drying. It is presumed that the majority of the silane-based monomer consumed for crosslinking reduces the amount of silane-based monomer that can react with the release layer during storage over time.

  In order to achieve the same object, in the polymer obtained by copolymerizing a monomer mixture containing (meth) acrylic acid alkyl ester as a main component and containing a silane monomer, the functional group-containing monomer described above is used. It is preferable to use methacrylic acid as a monomer. When using a polymer copolymerized with methacrylic acid, the increase in peel strength can be prevented because methacrylic acid is more hydrophobic than acrylic acid in the aqueous dispersion and is distributed to the inside of the fine particles. This is presumed to be because the hydrolysis of the silane monomer incorporated in was promoted.

  In this invention, a crosslinking agent can be used according to the use of an adhesive. As the crosslinking agent, a commonly used crosslinking agent can be used, and examples thereof include an isocyanate crosslinking agent, an epoxy crosslinking agent, an oxazoline crosslinking agent, an aziridine crosslinking agent, and a metal chelate crosslinking agent. The cross-linking agent may be either oil-soluble or water-soluble.

  The water-dispersed pressure-sensitive adhesive composition of the present invention is obtained by adding a tackifier containing a phenol skeleton to an aqueous dispersion of a (meth) acrylic acid ester polymer containing the silane monomer. .

  The tackifier used in the present invention is a compound containing a phenol skeleton in the molecule, and examples thereof include rosin phenol resin, terpene phenol resin, and alkylphenol resin.

  Here, rosin phenolic resins include “Tamanol” manufactured by Arakawa Chemical Industry Co., Ltd., “Sumilite Resin” manufactured by Sumitomo Durez Co., Ltd., and terpene phenolic resins manufactured by Yashara Chemical Co., Ltd. “Nanolet” and “YS”. Polystar ”,“ Mighty Ace ”, etc., and alkylphenol resins such as“ Hitanol ”manufactured by Hitachi Chemical Co., Ltd.,“ Tacchirol ”manufactured by Sumitomo Chemical Co., Ltd.,“ PP Series ”manufactured by Gunei Chemical Co., Ltd., etc. Commercial products can be used. These tackifiers may be used alone or in combination of two or more.

  When the amount of the tackifier is less than 5 parts by weight or more than 50 parts by weight with respect to 100 parts by weight of the polymer having the (meth) acrylic acid alkyl ester as a main component, practically sufficient adhesive properties can be obtained. In some cases, for example, adhesion to rubber-based foams may be insufficient. Therefore, in the present invention, the amount of the tackifier based on 100 parts by weight of the polymer is preferably 5 to 50 parts by weight, more preferably 10 to 40 parts by weight.

  In addition, the water-dispersed pressure-sensitive adhesive composition of the present invention is added with additives usually used for pressure-sensitive adhesives, for example, anti-aging agents, fillers, pigments, colorants and the like, if necessary. Also good.

  The water-dispersed pressure-sensitive adhesive composition of the present invention is usually adjusted to a pH of 7 to 9 using a base such as ammonia in order to stabilize the particles. In this case, if there is a large amount of residual ammonia, the release liner or back treatment layer coated with the silicone release agent will progress to heavy release over time, so the amount added is preferably small, and the pH is preferably about 7-8. preferable.

  Next, although the example of the adhesive sheet of this invention is demonstrated based on drawing, this invention is not limited to these at all.

  The pressure-sensitive adhesive sheet of the present invention has a configuration in which a pressure-sensitive adhesive layer made of the water-dispersed pressure-sensitive adhesive composition is provided on one side or both sides of a substrate. Drawing 1 is a sectional view showing typically an example of an adhesive sheet which has an adhesive layer on both sides of a substrate film.

  In FIG. 1, 5 is a pressure-sensitive adhesive sheet, 1 is a pressure-sensitive adhesive layer made of the water-dispersed pressure-sensitive adhesive composition, 2 is a base material, and 3 is a release liner. The pressure-sensitive adhesive sheet 5 is a water-dispersed type obtained by adding a tackifier containing a phenol skeleton to a copolymer of a monomer mixture containing a silane-based monomer and mainly composed of (meth) acrylic acid alkyl ester. The pressure-sensitive adhesive composition is obtained by applying the pressure-sensitive adhesive composition on the substrate 2 and thermally crosslinking to form the pressure-sensitive adhesive layer 1. And it is bonded with the release liner 3 to protect the adhesive surface. This is preferably wound as shown, but can also be stored as is. Further, after the pressure-sensitive adhesive layer 1 is formed on the release liner 3, it can be bonded to the substrate 2.

  In the present invention, examples of the substrate 2 include plastic films such as polypropylene film, ethylene-propylene copolymer film, polyester film, and polyvinyl chloride; papers such as Japanese paper and kraft paper; cloths such as cotton cloth and soft cloth Non-woven fabrics such as polyester non-woven fabric and vinylon non-woven fabric; metal foil can be used. The plastic film may be an unstretched film or a stretched (uniaxially stretched or biaxially stretched) film. Further, the surface of the base material to which the pressure-sensitive adhesive is applied may be subjected to a surface treatment such as a commonly used primer or a corona discharge method. Although the thickness of a base material can be suitably selected according to the objective, generally it is about 10-500 micrometers.

  The pressure-sensitive adhesive layer 1 is formed by using the water-dispersed pressure-sensitive adhesive composition as a base material by using a conventional coater such as a gravure roll coater, a reverse roll coater, a kiss roll coater, a dip roll coater, a bar coater, a knife coater, or a spray coater. 1 can be applied. The water-dispersed pressure-sensitive adhesive composition is applied so that the thickness of the pressure-sensitive adhesive layer after drying is, for example, about 10 to 100 μm.

  The applied water-dispersed pressure-sensitive adhesive composition is thermally crosslinked by heating to form the pressure-sensitive adhesive layer 1. Thermal crosslinking is performed by a conventional method, for example, by heating to a temperature at which a crosslinking reaction proceeds according to the type of silane monomer or crosslinking agent. The solvent insoluble content of the pressure-sensitive adhesive layer after crosslinking is, for example, about 15 to 70% by weight. Moreover, the molecular weight (weight average molecular weight; standard polystyrene conversion) of the solvent soluble part of the pressure-sensitive adhesive layer after crosslinking is, for example, about 100,000 to 600,000, preferably about 200,000 to 450,000. The molecular weight of the solvent-insoluble part and solvent-soluble part of the pressure-sensitive adhesive layer after crosslinking is, for example, the ratio of the silane monomer or functional group-containing monomer to the total amount of the monomer mixture, the chain transfer agent and the crosslinking agent. It can be arbitrarily set by appropriately adjusting the type and amount, particularly the amount of the silane monomer and the chain transfer agent.

  In the present invention, the release liner 3 is provided with a release layer composed of a silicone release agent, a long-chain alkyl release agent, a fluorine release agent, etc. on one or both sides of a thin-leaf substrate, and has been conventionally used. Is used. Although the thickness is not specifically limited, Preferably it is 15 micrometers or more, More preferably, it is 25-500 micrometers.

  FIG. 2 is a cross-sectional view schematically showing another example of the pressure-sensitive adhesive sheet of the present invention, in which the pressure-sensitive adhesive layer 1 is provided on one side of the substrate 2 and the pressure-sensitive adhesive is different from the pressure-sensitive adhesive layer 1 on the other side. A pressure-sensitive adhesive layer 4 made of an adhesive composition is provided to form a pressure-sensitive adhesive sheet 6. A release liner 3 is bonded to protect the adhesive surface. Here, the pressure-sensitive adhesive layer 4 is not particularly limited, and conventionally known pressure-sensitive adhesive compositions such as acrylic, rubber-based, and silicone-based materials can be used depending on the application and the type of adherend. This is preferably wound as shown, but can also be stored as is. In FIG. 2, the release liner 3 is configured to contact the pressure-sensitive adhesive layer 4, but may be configured to contact the pressure-sensitive adhesive layer 1. In this case, what is necessary is just to change the structure according to the kind of to-be-adhered body which sticks an adhesive sheet first.

  FIG. 3 is a cross-sectional view schematically showing another example of the pressure-sensitive adhesive sheet of the present invention, in which a pressure-sensitive adhesive layer 1 is provided on one side of a substrate 2 and a release liner 3 is bonded thereto. Show. This is preferably wound as shown, but can also be stored as is.

  FIG. 4 is a cross-sectional view schematically showing another example of the pressure-sensitive adhesive sheet of the present invention, and shows a configuration in which the pressure-sensitive adhesive layer 1 is attached to the base material 2 provided with the back treatment layer 7. As shown in the figure, this is wound and stored so that the pressure-sensitive adhesive layer 1 is in contact with the back treatment layer 4.

  In the present invention, the back treatment layer 7 may be formed by providing the base material 1 with a silicone-based release agent, a long-chain alkyl-type release agent, a fluorine-type release agent, or the like by a conventionally known method.

  The pressure-sensitive adhesive sheet of the present invention has an excellent adhesive force to rubber foam, and is usually 3 N / 20 mm or more, preferably 4 N / 20 mm or more, more preferably 5 N / 20 mm or more (180 Degree peel, peel rate 300 mm / min, 23 ° C., 60% RH atmosphere).

  The present invention also provides a rubber foam pressure-sensitive adhesive sheet, wherein the pressure-sensitive adhesive layer comprising the water-dispersed pressure-sensitive adhesive composition is provided on one side or both sides of the rubber foam, and the pressure-sensitive adhesive sheet is provided on one side of the rubber foam. Or the rubber foam adhesive sheet characterized by providing in both surfaces is provided.

  FIG. 5 is a cross-sectional view schematically showing an example of a rubber foam pressure-sensitive adhesive sheet in which the pressure-sensitive adhesive sheet 5 illustrated in FIG. 1 is provided on one surface of the rubber foam. In FIG. 5, 8 indicates a rubber foam, and the others are as described above. Moreover, the adhesive sheet 5 can also be provided on both surfaces of the rubber foam 8.

  FIG. 6 is a cross-sectional view showing another example of the foam pressure-sensitive adhesive sheet of the present invention, in which the pressure-sensitive adhesive sheet 6 illustrated in FIG. 2 is provided on one surface of the rubber foam 8. In this case, the pressure-sensitive adhesive sheet 6 is configured to adhere to the foam 8 via the pressure-sensitive adhesive layer 1. Moreover, the adhesive sheet 6 can also be provided on both surfaces of the rubber foam 8.

  Moreover, this invention can also be set as the so-called base material-less double-sided adhesive sheet which does not contain a base material by forming the adhesive layer 1 on the release liner 3. FIG. For example, as shown in the cross-sectional view of FIG. 7, a rubber foam adhesive having a pressure-sensitive adhesive layer made of a water-dispersed pressure-sensitive adhesive composition provided on one side (or both sides) of a rubber foam by bonding to the foam 8. It can be a sheet.

  In the present invention, the rubber foam 8 can be prepared by vulcanizing and foaming an admixture containing a rubber polymer, a vulcanizing agent, a foaming agent, a vulcanization accelerator, a foaming aid and the like by heating.

  The rubber-based polymer is not particularly limited and may be any suitable one according to conventional methods. For example, ethylene / propylene / diene rubber (EPDM), ethylene / propylene rubber, ethylene / propylene terpolymer, silicone rubber, fluorine Rubber, acrylic rubber, polyurethane rubber, polyamide rubber, natural rubber, polyisobutylene, polyisoprene, chloroprene rubber, butyl rubber, nitrile butyl rubber, styrene-butadiene rubber, styrene-butadiene-styrene rubber, styrene-isoprene-styrene rubber Styrene-ethylene-butadiene rubber, styrene-ethylene-butylene-styrene rubber, styrene-isoprene-propylene-styrene rubber, α-olefins such as chlorosulfonated polyethylene and butene-1 Rubber copolymer containing cyclic or acyclic polyene component has a non-conjugated double bonds, such as Ropentajien and ethylidene norbornene. From the standpoint of practicality and the like, EPDM can be preferably used.

  There are no particular limitations on the vulcanizing agent, and any suitable vulcanizing agent can be used. Examples include sulfur, sulfur compounds, selenium, magnesium oxide, lead monoxide, zinc oxide, organic peroxides, and polyamines. Oximes (eg, p-quinone dioxime, p, p′-dibenzoylquinone dioxime, etc.), nitroso compounds (eg, p-dinitrosobenzidine), resins (eg, alkylphenol-formaldehyde resin, melamine-formaldehyde condensate) And ammonium salts (for example, ammonium benzoate).

  These vulcanizing agents can be used by appropriately selecting one or more kinds, and from the viewpoint of physical properties such as durability resulting from vulcanization and foamability of the obtained rubber foam, Sulfur and sulfur compounds, particularly sulfur can be preferably used. The amount of the vulcanizing agent can be appropriately determined according to the vulcanization efficiency based on the type of the vulcanizing agent. For example, in the case of sulfur or sulfur compounds, the amount is usually 0.1 per 100 parts by weight of the rubber-based polymer. -10 parts by weight, preferably 0.5-5 parts by weight are used.

  Moreover, there is no restriction | limiting in particular as a foaming agent, For example, an inorganic type foaming agent and an organic type foaming agent are used.

  As the inorganic foaming agent, for example, ammonium carbonate, ammonium hydrogen carbonate, sodium hydrogen carbonate, ammonium nitrite, sodium borohydride, azides and the like are used. Examples of the organic foaming agent include azo compounds (for example, azobisisobutyronitrile, azodicarboxylic acid amide (ADCA), barium azodicarboxylate, etc.), fluorinated alkanes (for example, trichloromonofluoromethane, dichloromonofluoro). Methane, etc.), hydrazine compounds (eg, p-toluenesulfonyl hydrazide, diphenylsulfone-3,3′-disulfonyl hydrazide, 4,4′-oxybis (benzenesulfonyl hydrazide), etc.), semicarbazide compounds (eg, p-toluene) Irenesulfonyl semicarbazide, 4,4'-oxybis (benzenesulfonyl semicarbazide), etc.), triazole compounds (for example, 5-morpholyl-1,2,3,4-thiatriazole), N-nitroso compounds (N, N'- Gini Nitroso pentamethylene tetramine, N, N'-dimethyl -N, N'-dinitrosoterephthalamide) and the like.

  These foaming agents can be used by appropriately selecting one or more kinds, and from the viewpoint of physical properties resulting from foamability of the resulting rubber foam, preferably an azo compound or an N-nitroso compound Organic foaming agents such as are used. The blending ratio of the foaming agent can be appropriately determined according to the physical properties of the desired foam, and is generally 0.1 to 100 parts by weight, preferably 0.5 to 100 parts by weight per 100 parts by weight of the rubber-based polymer. 50 parts by weight, more preferably 1 to 30 parts by weight.

  Moreover, in this rubber foam, it is preferable to blend a vulcanization accelerator to promote vulcanization and a foaming aid to ensure good foaming.

  Examples of the vulcanization accelerator include dithiocarbamic acids (for example, sodium dimethyldithiocarbamate, sodium diethyldithiocarbamate, zinc dimethyldithiocarbamate, zinc diethyldithiocarbamate), thiaazoles (for example, 2-mercaptobenzothiazole, dibenzothiazyl disulfide, etc.) , Guanidines (eg, diphenylguanidine, geo-tolylguanidine, etc.), sulfenamides (eg, benzothiazyl-2-diethylsulfenamide, N-cyclohexyl-2-benzothiazylsulfenamide, etc.), thiurams (eg, Tetramethylthiuram monosulfide, tetramethylthiuram disulfide, etc.), xanthates (eg, sodium isopropylxanthate, isopropyl Zinc santogenate), aldehyde ammonia (eg, acetaldehyde ammonia, hexamethylenetetramine, etc.), aldehyde amines (eg, n-butyraldehyde aniline, butyraldehyde monobutylamine, etc.), thioureas (eg, diethylthiourea, trimethylthiourea, etc.) Used. Such vulcanization accelerators can be used by appropriately selecting one or more kinds. For example, from the viewpoint of vulcanization speed and the like, it is preferable to use dithiocarbamic acids and thiazoles in combination.

  Further, the blending ratio of the vulcanization accelerator is, for example, 0.1 to 10 parts by weight, preferably 0.5 to 5 parts by weight with respect to 100 parts by weight of the rubber polymer, from the viewpoint of bloom resistance, vulcanization speed and the like. is there.

  Contrary to the vulcanization accelerator, for the purpose of controlling molding processability, for example, organic acids (for example, phthalic anhydride, benzoic acid, salicylic acid, etc.) and amines (for example, N-nitroso-diphenylamine, N-nitroso-) Vulcanization retarders such as phenyl-β-naphthylamine) may be added as appropriate.

  Examples of foaming aids include urea compounds, salicylic acid compounds, benzoic acid compounds, and the like. These foaming auxiliaries can be used by appropriately selecting one or more kinds, and urea-based compounds are preferably used from the viewpoints of little influence on vulcanization and low cost. The blending ratio of the foaming aid is, for example, 1 to 15 parts by weight, preferably 2 to 10 parts by weight, and more preferably 3 to 8 parts by weight with respect to 100 parts by weight of the rubber polymer.

  Furthermore, in this rubber foam, it is preferable to blend a filler, processing oil, lubricant, etc. according to its use. For example, plasticizer, flame retardant, anti-aging agent, antioxidant, pigment, colorant Moreover, you may mix | blend well-known additives, such as a fungicide, suitably.

  As the filler, for example, zinc white, carbon black, calcium carbonate, magnesium carbonate, silicic acid or salts thereof, talc, mica, bentonite, silica, alumina, aluminum silicate, acetylene black, aluminum powder and the like are used. One or more of these fillers can be appropriately selected and used. Zinc white is also preferably used because it acts as a stabilizer and carbon black also acts as a reinforcing material. In general, calcium carbonate is awarded. The blending ratio of the filler is, for example, 80 to 200 parts by weight, preferably 10 to 180 parts by weight with respect to 100 parts by weight of the rubber polymer.

  As the processing oil, paraffinic oil or petroleum oil is used, and preferably process oil is used. The blending ratio of the processing oil is, for example, 10 to 60 parts by weight, preferably 30 to 50 parts by weight with respect to 100 parts by weight of the rubber polymer. By adding the processing oil, the mixture can be easily kneaded and foamed easily.

  As the lubricant, for example, stearic acid or esters thereof are used, and the blending ratio thereof is, for example, 1 to 5 parts by weight, preferably 2 to 4 parts by weight with respect to 100 parts by weight of the rubber-based polymer. By adding a lubricant, for example, it becomes difficult to adhere to a roll during kneading, and processability can be improved.

  Further, examples of the plasticizer include paraffins (for example, chlorinated paraffin), waxes, naphthenes, aromas, asphalts, dry oils (for example linseed oil), animal and vegetable oils, low molecular weight polymers, and phthalates. , Phosphoric acid esters, alkylsulfonic acid esters, tackifiers and the like are used. By adding a plasticizer, the mixture becomes soft and easily foamed.

  As the flame retardant, for example, aluminum hydroxide or magnesium hydroxide is used.

Further, in this rubber foam, a non-rubber polymer may be appropriately blended depending on the purpose and application, for example, acrylic polymer (for example, poly (meth) acrylic acid alkyl ester), polyvinyl chloride, polyethylene, polypropylene. , Ethylene-vinyl acetate copolymer, polyvinyl acetate, polyamide, polyester, chlorinated polyethylene, urethane polymer, styrene polymer, silicone polymer, epoxy resin and the like are used.

  These non-rubber polymers can be used by appropriately selecting one or more kinds according to the purpose and application, and the blending ratio thereof is, for example, 50% by weight or less, preferably 30% by weight of the rubber polymer. % Or less, more preferably 15% by weight or less.

  The rubber foam admixture of the present invention is prepared by first kneading compounding components such as a rubber polymer, a vulcanization aid, a filler, and processing oil through a kneader such as a kneader or a mixing roll. Adjust things. In this kneading, heating may be appropriately performed. Next, a vulcanizing agent, a foaming agent and a foaming aid are further appropriately selected and blended into the blend, and this is further kneaded using a mixing roll or the like and then heated.

  The rubber foam of the present invention can be formed by heating the above-mentioned admixture and subjecting it to vulcanization and foaming treatment. In forming the rubber foam, the admixture is formed into a predetermined form such as a sheet as necessary. The molded body can be heat-treated to obtain a vulcanized foam. In that case, the molded body may be molded into an arbitrary form by an appropriate method, and the form is not particularly limited.

  Therefore, the molded product before the vulcanization foaming treatment may be obtained by molding the admixture into a sheet or other form by an appropriate method such as a mixing roll, a calender roll, or extrusion molding. It may be formed into a predetermined form having irregularities by an appropriate method such as injection molding or press molding.

  In the above, in the formation of a foam having a concavo-convex shape, an unvulcanized molded body is placed on a mold having a concavo-convex shape and heated to allow the mixture forming the molded body to flow intrude into the concavo-convex shape of the mold. A method of vulcanizing and foaming can also be adopted. Such a method has an advantage that the concavo-convex shape can be accurately formed even in the case of a mold having a complex and deep concavo-convex structure.

  Therefore, the size of the molded body is arbitrary and can be appropriately determined according to the form of the target rubber foam. In the case of a sheet or the like, the thickness is generally 100 mm or less, preferably 1 μm to 80 mm, particularly 10 μm to 50 mm.

  The vulcanization foaming treatment described above can be performed under appropriate conditions according to the prior art depending on the vulcanization start temperature, foaming temperature, and the like using the vulcanizing agent and the foaming agent used. The general vulcanization foaming temperature is about 200 ° C. or less, preferably 120 to 180 ° C. In general, the vulcanization and foaming treatment softens the admixture and decomposes the foaming agent to form a foam structure, and vulcanization proceeds to form the desired vulcanized foam. The vulcanization and foaming treatment can be performed under pressure for the purpose of adjusting the expansion ratio. The pressurizing condition can be based on the conventional one.

The expansion ratio (density ratio before and after foaming) of the rubber foam to be formed is appropriately determined according to the purpose of use. Generally, it is 0.5 g / cm ³ or less, preferably 0.20 g / cm ³ or less, more preferably 0.15 g / cm ³ or less based on the density. Such density can be controlled by adjusting the foaming ratio and the like according to the blending amount of the foaming agent described above, the processing time and temperature of vulcanization foaming, and the like. In addition, the foamed structure such as the independent and continuous vulcanized foams and the mixture thereof can be controlled through adjustment of the foaming ratio.

  The rubber foam pressure-sensitive adhesive sheet according to the present invention is desirable in terms of environmental hygiene because it uses a water-dispersed acrylic pressure-sensitive adhesive, exhibits excellent terminal peeling properties and retention properties, and has a stable adhesive force over time. A foam pressure-sensitive adhesive sheet can be obtained. Therefore, it can be used for various applications according to the prior art, such as cushioning materials, pad materials, sealing materials for various purposes such as airtightness and waterproofing, heat insulating materials, vibration reducing materials such as soundproofing and vibration damping.

  The following examples further illustrate the present invention in detail but are not to be construed to limit the scope thereof. “Parts” and “%” are based on weight unless otherwise specified.

Example 1
Using a reaction vessel equipped with a cooling pipe, a nitrogen introduction pipe, a thermometer and a stirrer, 70 parts of butyl acrylate, 30 parts of 2-ethylhexyl acrylate, 3 parts of acrylic acid, 3-methacryloyloxypropyltrimethoxysilane (Shin-Etsu Silicone Co., Ltd.) Company "KBM-503") 0.05 parts, dodecanethiol (chain transfer agent) 0.05 parts, 2,2'-azobis [2- (5-methyl-2-imidazolin-2-yl) propane] dihydro 0.1 parts of chloride (initiator) was added to 100 parts of water to which 1.5 parts of sodium polyoxyethylene lauryl sulfate (emulsifier) was added, followed by emulsion polymerization to obtain a polymer. In addition, the solvent-insoluble matter of the polymer at the time of completion | finish of superposition | polymerization at the time of superposing | polymerizing similarly with the composition which does not mix a silane type monomer was 0%.

  After adjusting the pH to 8 by adding 10% ammonium water, 0.06 part of n-decyltrimethoxysilane (“AY43-210MC” manufactured by Toray Dow Corning Silicone Co., Ltd.) as a silane compound was added and water was added. A dispersion was obtained. To this, 30 parts of rosin phenolic resin (“TAMANOL E-100” manufactured by Arakawa Chemical Industries, Ltd.) as a tackifier was added as a tackifier to 100 parts of solid content to obtain a water-dispersed adhesive.

  This is coated on the heavy release surface of a release liner (“SLB-80W5D” manufactured by Kite Chemical Industries, Ltd.) coated with a silicone release agent, and dried at 120 ° C. for 3 minutes to provide a 70 μm thick adhesive layer Thus, an adhesive sheet was prepared. This pressure-sensitive adhesive sheet was bonded to both surfaces of a nonwoven fabric (PR-14 manufactured by Nippon Paperboard Co., Ltd.) to produce a pressure-sensitive adhesive sheet.

Example 2
In Example 1 above, instead of adding a rosin phenolic resin (“Tamanol E-100” manufactured by Arakawa Chemical Industries, Ltd.) as a tackifier, a rosin phenolic resin (“Sumilite Resin PR12603” manufactured by Sumitomo Duretz Co., Ltd.) A pressure-sensitive adhesive sheet was prepared in the same manner as in Example 1 except that 30 parts of the aqueous dispersion was added in solid content.

Example 3
In Example 1 above, instead of adding a rosin phenolic resin (“Tamanol E-100” manufactured by Arakawa Chemical Industries, Ltd.) as a tackifier, water dispersion of a terpene phenolic resin (“Nanolet G1450” manufactured by Yashara Chemical Co., Ltd.) A pressure-sensitive adhesive sheet was prepared in the same manner as in Example 1 except that 30 parts of the liquid was added in solid content.

Comparative Example 1
In Example 1 above, instead of adding a rosin phenolic resin (“Tamanol E-100” manufactured by Arakawa Chemical Industries, Ltd.) as a tackifier, a polymerized rosin ester resin (“Super Ester E- manufactured by Arakawa Chemical Industries, Ltd.”) was used. 625)) was added in the same manner as in Example 1 except that 30 parts of solid content was added.

Comparative Example 2
In the said Example 1, the adhesive sheet was produced like Example 1 except not having added the tackifier.

Comparative Example 3
Using a reaction vessel equipped with a cooling pipe, a nitrogen introduction pipe, a thermometer and a stirrer, 70 parts of butyl acrylate, 30 parts of 2-ethylhexyl acrylate, 3 parts of acrylic acid, 0.07 part of dodecanethiol (chain transfer agent), 2,2′-azobis [2- (5-methyl-2-imidazolin-2-yl) propane] dihydrochloride (initiator) 0.1 part, polyoxyethylene nonylphenyl ether sodium sulfate (emulsifier) 1.5 In addition to 100 parts of water to which parts were added, emulsion polymerization was performed to obtain a polymer.

  To this, 10% by weight ammonium water was added to adjust the pH to 8. To this, 100 parts of rosin phenolic resin (“TAMANOL E-100” manufactured by Arakawa Chemical Industries, Ltd.) as a tackifier is added to 100 parts of solid content, and further water-soluble epoxy type cross-linking agent (TEPIC: Mitsubishi). 0.14 part of Gas Chemical Co., Ltd.) was added to obtain a water-dispersed pressure-sensitive adhesive.

  A pressure-sensitive adhesive sheet was produced in the same manner as in Example 1.

  The following characteristics were examined for the pressure-sensitive adhesive sheets obtained in the above Examples and Comparative Examples. The results are shown in Table 1.

(Adhesive strength to rubber foam)
A PET film having a thickness of 40 μm was bonded to one side of the pressure-sensitive adhesive sheets obtained in Examples and Comparative Examples, and this was cut into a width of 20 mm and a length of 100 mm to prepare a test piece for evaluation. This test piece was pressure-bonded by a method in which an EPDM rubber foam containing a paraffinic oil and asphalt as a plasticizer was affixed to a metal plate, and a 2 kg roller was reciprocated once, and the test piece was 30 ° C at 23 ° C. The force required for peeling after standing for a minute was measured. The measurement conditions were performed using a universal tensile tester “TCM-1kNB” manufactured by Minebea Co., Ltd. in a 180 ° peel, a peeling rate of 300 mm / min, 23 ° C., and 60% RH atmosphere (see FIG. 8).

(Terminal peelability test)
The pressure-sensitive adhesive sheets prepared in Examples and Comparative Examples were attached to an EPDM rubber foam (thickness 5 mm) containing paraffinic oil and asphalt as plasticizers, cut into a width of 10 mm and a length of 50 mm for evaluation. A test piece was prepared. One end of the test piece was attached to the end of the ABS plate with a contact area of 10 mm × 10 mm (front surface), and the remaining portion (width 10 mm × 40 mm) was folded and attached to the back surface of the ABS plate. After leaving this in an atmosphere of 70 ° C. for 2 hours, the presence or absence of peeling of the rubber foam from the ABS plate on the front surface was evaluated (see FIG. 9).

(Adhesive strength of rubber foam adhesive sheet)
The pressure-sensitive adhesive sheets prepared in Examples and Comparative Examples were attached to an EPDM rubber foam (thickness 5 mm) containing paraffinic oil and asphalt as plasticizers, cut into a width of 20 mm and a length of 100 mm for evaluation. A test piece was prepared. This test piece was pressure-bonded by a method in which a 2 kg roller was reciprocated once using an SUS plate as an adherend, left at 23 ° C. for 30 minutes (initial value), and left at 60 ° C./90% RH atmosphere for 7 days. After the storage (after storage over time), the force required for peeling was measured. The measurement conditions were 90 ° peel, peeling rate 300 mm / min, 23 ° C., 60% RH atmosphere using a Minebea Co., Ltd. universal tensile tester “TCM-1kNB” (see FIG. 10).

  As is clear from Table 1, the water-dispersed pressure-sensitive adhesives (Examples 1 to 3) of the present invention have satisfactory performance in all of the adhesive strength to rubber foam, terminal peelability, and adhesive strength after storage over time. Indicated.

In contrast, Comparative Example 1 using a polymerized rosin ester not containing a phenol skeleton as a tackifier showed satisfactory performance in adhesion to rubber foam and terminal peelability, but adhesion after storage over time. It was inferior to. Moreover, the comparative example 2 which does not add a tackifier was inferior to the adhesive force to a rubber foam, and terminal peelability. Furthermore, the water-dispersed pressure-sensitive adhesive (Comparative Example 3) that was crosslinked using an epoxy crosslinking agent without copolymerizing a silane monomer was inferior in terminal peelability.

It is sectional drawing which shows an example of the adhesive sheet of this invention typically. It is sectional drawing which shows another example of the adhesive sheet of this invention typically. It is sectional drawing which shows another example of the adhesive sheet of this invention typically. It is sectional drawing which shows another example of the adhesive sheet of this invention typically. It is sectional drawing which shows typically an example of the rubber foaming adhesive sheet of this invention. It is sectional drawing which shows typically another example of the rubber foaming adhesive sheet of this invention. It is sectional drawing which shows typically another example of the rubber foaming adhesive sheet of this invention. It is explanatory drawing which shows typically the measuring method of the adhesive force to the rubber foam in the Example of this invention. It is explanatory drawing which shows typically the measuring method of the terminal peelability test in the Example of this invention. It is explanatory drawing which shows typically the measuring method of the adhesive force of the rubber foam adhesive sheet in the Example of this invention.

Explanation of symbols

1: Adhesive layer 2: Base material 3: Release liner 4: Adhesive layer 5: Adhesive sheet 6: Adhesive sheet 7: Back treatment layer 8: Foam

Claims (11)

A tackifier containing a phenol skeleton is added to an aqueous dispersion of a polymer obtained by copolymerizing a monomer mixture containing a (meth) acrylic acid alkyl ester and containing a silane monomer. A water-dispersed pressure-sensitive adhesive composition. The water-dispersed pressure-sensitive adhesive composition according to claim 1, wherein when the polymer is polymerized with a composition containing (meth) acrylic acid alkyl ester as a main component and no silane monomer, the solvent-insoluble component is present. A monomer mixture from which a resin composition of 5% or less is obtained and 0.005 to 1 part by weight of a silane monomer based on 100 parts by weight of the monomer mixture are combined under the same conditions as described above. A water-dispersed pressure-sensitive adhesive composition, which is a polymer obtained by polymerization. 3. The water-dispersed pressure-sensitive adhesive composition according to claim 1, wherein 0.005 to 1 part by weight of an organic compound capable of binding to a silane monomer is added to 100 parts by weight of the polymer. Water-dispersed pressure-sensitive adhesive composition. The water-dispersed pressure-sensitive adhesive composition according to claim 3, wherein the organic compound capable of binding to the silane monomer is a silane compound. The water-dispersed pressure-sensitive adhesive composition according to claim 1, wherein the silane monomer is a methoxysilane monomer. The water-dispersed pressure-sensitive adhesive composition according to any one of claims 1 to 5, wherein methacrylic acid is copolymerized in the polymer. The water-dispersed pressure-sensitive adhesive composition according to any one of claims 1 to 6, wherein the tackifier is a rosin phenol-based or terpene phenol-based tackifier. The adhesive sheet which provided the adhesive layer which consists of a water-dispersed adhesive composition in any one of Claims 1-7 on the single side | surface of the base material. The adhesive sheet which provided the adhesive layer which consists of a water-dispersed adhesive composition in any one of Claims 1-7 on both surfaces of the base material. A rubber foam pressure-sensitive adhesive sheet, wherein a pressure-sensitive adhesive layer comprising the water-dispersed pressure-sensitive adhesive composition according to claim 1 is provided on one side or both sides of a rubber foam. A rubber foam pressure-sensitive adhesive sheet, wherein the pressure-sensitive adhesive sheet according to claim 8 is provided on one side or both sides of a rubber foam.

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