JP2005225975A - Pressure-sensitive adhesive composition and pressure-sensitive adhesive sheet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a pressure-sensitive adhesive composition capable of developing excellent tackiness even when the blending amount of a metal hydroxide is increased so that the effect of affording flame-retardancy is fully developed, and to prepare a pressure-sensitive adhesive tape provided with a tacky layer comprising the pressure-sensitive adhesive composition. <P>SOLUTION: The pressure-sensitive adhesive composition is prepared by blending a pressure-sensitive adhesive component, an emulsifier and a metal hydroxide so that the amount of the metal hydroxide becomes 100-300 pts.wt. based on 100 pts.wt. solid of the pressure-sensitive adhesive component. The pressure-sensitive adhesive sheet is provided with the tacky layer comprising the pressure-sensitive adhesive composition. The pressure-sensitive composition can exhibit a water-activation property exhibiting tackiness in the presence of water through the coexistence of the emulsifier and the metal hydroxide. Thereby the pressure-sensitive adhesive sheet can exhibit excellent flame-retardancy as well as excellent tackiness by the development of the water-activation property. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a pressure-sensitive adhesive composition and a pressure-sensitive adhesive sheet, and particularly relates to a pressure-sensitive adhesive composition and a pressure-sensitive adhesive sheet including a pressure-sensitive adhesive layer made of the pressure-sensitive adhesive composition and used as a tape, film, sheet, or the like.

  In recent years, in various fields such as electronic equipment, home electric appliances, vehicles, and housing construction materials, various studies have been made on the flame retardancy of plastic materials, and the flame retardancy is also considered for the adhesive sheets used for them. ing.

  As a method for imparting flame retardancy to an adhesive sheet, for example, a method of incorporating an olefin polymer and an inorganic flame retardant into a base material of an adhesive sheet is known (see, for example, Patent Document 1).

  However, since the base material is highly flammable, it is necessary to increase the blending amount of the flame retardant in order to obtain sufficient flame retardancy. However, if the blending amount of the flame retardant is increased, the physical properties of the base material may change and the adhesiveness may decrease. In addition, since a plurality of types of base materials are usually prepared for a specific pressure-sensitive adhesive corresponding to various applications, it is very complicated to mix a flame retardant for each of the plurality of types of base materials. It is.

  On the other hand, a method of adding a flame retardant to the adhesive layer is also known. According to this, if a flame retardant is blended with a specific pressure-sensitive adhesive, it is not necessary to blend a flame retardant for each of a plurality of types of base materials, and the troublesome work can be saved.

  Halogen flame retardants are generally used as flame retardants in the adhesive, but various use of non-halogen flame retardants has been studied from the viewpoint of environmental safety. The non-halogen flame retardant has a lower effect of imparting flame retardancy than the halogen flame retardant, and therefore it is necessary to increase the blending amount of the flame retardant in order to obtain sufficient flame retardancy. However, when the blending amount of the flame retardant is increased, the physical properties of the pressure-sensitive adhesive may change and the tackiness may decrease, as in the case of blending with the base material.

Therefore, the blending amount of the non-halogen flame retardant with respect to the pressure-sensitive adhesive is limited. For example, the metal hydroxide 40 having a particle size of 0.01 to 20 μm with respect to 100 parts by weight of the rubber-based pressure-sensitive adhesive or the acrylic pressure-sensitive adhesive. A flame retardant pressure-sensitive adhesive composition obtained by blending ˜150 parts by weight as a flame retardant has been proposed (for example, see Patent Document 2).
JP 2003-13022 A JP 2003-105295 A

  However, the compounding amount of the metal hydroxide described in Patent Document 2 is insufficient in providing flame retardancy.

  An object of the present invention is to provide a pressure-sensitive adhesive composition that can exhibit excellent adhesiveness even when the amount of the metal hydroxide is increased so that the effect of imparting flame retardancy is sufficiently exhibited, and It is providing the adhesive sheet provided with the adhesion layer which consists of an adhesion composition.

  In order to achieve the above object, the pressure-sensitive adhesive composition of the present invention contains a pressure-sensitive adhesive component, an emulsifier, and a metal hydroxide, and the metal hydroxide is 100 to 100 parts by weight based on 100 parts by weight of the solid content of the pressure-sensitive adhesive component. It is characterized by containing it at a ratio of 300 parts by weight.

  Moreover, the pressure-sensitive adhesive composition of the present invention comprises a pressure-sensitive adhesive component containing an emulsifier and a metal hydroxide in a proportion of 100 to 300 parts by weight of the metal hydroxide with respect to 100 parts by weight of the solid content of the pressure-sensitive adhesive component. It is characterized by containing.

  In the pressure-sensitive adhesive composition of the present invention, it is preferable that the metal hydroxide is aluminum hydroxide and / or magnesium hydroxide.

  In the pressure-sensitive adhesive composition of the present invention, it is preferable that the pressure-sensitive adhesive component contains an acrylic polymer as a main component.

  Further, in the pressure-sensitive adhesive composition of the present invention, the acrylic polymer is obtained by emulsion polymerization of a monomer component mainly composed of (meth) acrylic acid alkyl ester with the emulsifier. The system polymer preferably contains a water-dispersed polymer dispersed in water.

  Moreover, this invention contains the adhesive sheet provided with the adhesion layer which consists of an above-mentioned adhesive composition.

  Since the pressure-sensitive adhesive composition of the present invention contains a pressure-sensitive adhesive component, an emulsifier, and a metal hydroxide, the coexistence of the emulsifier and the metal hydroxide provides a water rejuvenating activity that develops adhesiveness in the presence of water. be able to. Therefore, in the pressure-sensitive adhesive composition of the present invention, even if the compounding amount of the metal hydroxide is increased so that the effect of imparting flame retardancy is sufficiently manifested by the expression of such water-hydrating activity, excellent adhesion Sex can be expressed.

  The pressure-sensitive adhesive composition of the present invention contains a pressure-sensitive adhesive component, an emulsifier and a metal hydroxide, and contains the metal hydroxide in a proportion of 100 to 300 parts by weight with respect to 100 parts by weight of the solid content of the pressure-sensitive adhesive component. Preferably, the pressure-sensitive adhesive composition of the present invention comprises a pressure-sensitive adhesive component containing an emulsifier and a metal hydroxide, and the metal hydroxide is 100 to 300 parts by weight with respect to 100 parts by weight of the solid content of the pressure-sensitive adhesive component. It is contained at a ratio of parts.

  In the present invention, the pressure-sensitive adhesive component is not particularly limited, and a known pressure-sensitive adhesive component usually used for a pressure-sensitive adhesive sheet is used. For example, water-dispersed pressure-sensitive adhesives such as acrylic water-dispersed pressure-sensitive adhesives and natural rubber latex-based water-dispersed pressure-sensitive adhesives, preferably those containing an emulsifier described later. Preferably, an acrylic water-dispersed pressure-sensitive adhesive, more specifically, an acrylic water-dispersed polymer containing an acrylic polymer as a main component, preferably containing an emulsifier described later. The acrylic water-dispersed polymer can exhibit excellent tackiness and weather resistance.

  The acrylic water-dispersed polymer is a water-dispersed polymer in which an acrylic polymer obtained by polymerization of a monomer component mainly composed of (meth) acrylic acid ester is dispersed in water. It can be produced by subjecting a monomer component mainly composed of (meth) acrylic acid alkyl ester to emulsion polymerization with an emulsifier described later. If it manufactures in this way, the adhesion ingredient containing an emulsifier can be manufactured simply and efficiently.

  The (meth) acrylic acid ester is a methacrylic acid ester and / or an acrylic acid ester, and examples thereof include a compound represented by the following general formula (1).

CH ₂ = CR1COOR2 (1)
(In the formula, R 1 represents hydrogen or a methyl group, and R 2 represents a linear or branched alkyl group having 1 to 17 carbon atoms.)
As R2, for example, methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, sec-butyl group, t-butyl group, pentyl group, neopentyl group, isoamyl group, hexyl group, heptyl group, Examples include octyl group, isooctyl group, 2-ethylhexyl group, isononyl group, decyl group, isodecyl group, lauryl group, myristyl group, pentadecyl group, stearyl group and the like.

  More specifically, for example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate, Sec-butyl (meth) acrylate, t-butyl (meth) acrylate, pentyl (meth) acrylate, neopentyl (meth) acrylate, isoamyl (meth) acrylate, hexyl (meth) acrylate, (meth) acrylic Acid heptyl, octyl (meth) acrylate, isooctyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isononyl (meth) acrylate, decyl (meth) acrylate, isodecyl (meth) acrylate, (Meth) lauryl acrylate, (meth) acrylate myristyl, (meth) acrylate pen Decyl, and the like (meth) stearyl acrylate.

  These (meth) acrylic acid esters are appropriately used alone or in combination. For example, butyl acrylate can be used alone, or butyl acrylate and 2-ethylhexyl acrylate can be used in combination. In such a case, the weight ratio of butyl acrylate to 2-ethylhexyl acrylate Are used in the range of 0/100 to 55/45 (for example, 5/95 to 60/40).

  Moreover, the compounding quantity of (meth) acrylic acid ester is 80 weight part or more (for example, 85-99.8 weight part) with respect to 100 weight part of monomer components, Preferably, 85 weight part or more (for example, 85-85 weight part). 99.5 parts by weight), more preferably 90 parts by weight or more (for example, 90 to 99.0 parts by weight).

  The monomer component usually contains a functional group-containing monomer containing a functional group (thermally crosslinkable functional group-containing monomer) in order to introduce a crosslinking point for thermal crosslinking. By copolymerizing such a functional group-containing monomer, it is possible to improve the adhesion to the adherend.

  Examples of such functional group-containing monomers include carboxyl group-containing monomers such as acrylic acid, methacrylic acid, itaconic acid, maleic acid, crotonic acid, and maleic anhydride, or acid anhydrides thereof such as (meta ) Hydroxyl-containing monomers such as 2-hydroxyethyl acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, such as (meth) acrylamide, N, N-dimethyl (meth) Amide group-containing monomers such as acrylamide, N-methylol (meth) acrylamide, N-methoxymethyl (meth) acrylamide, N-butoxymethyl (meth) acrylamide, for example, dimethylaminoethyl (meth) acrylate, (meth) Amino group-containing monomers such as t-butylaminoethyl acrylate, such as (Me ) Glycidyl group-containing monomers such as glycidyl acrylate, other (meth) acrylonitrile, N- (meth) acryloyl morpholine, N- vinyl-2-pyrrolidone.

  These functional group-containing monomers are appropriately used alone or in combination. Moreover, the compounding quantity of a functional group containing monomer is 0.5-12 weight part with respect to 100 weight part of (meth) acrylic acid ester, Preferably, it is 1-8 weight part. Among these, as the functional group-containing monomer, a carboxyl group-containing monomer such as acrylic acid or methacrylic acid or an acid anhydride thereof is preferably used.

  Further, the monomer component includes, for example, a copolymerizable monomer copolymerizable with (meth) acrylic acid ester, if necessary, in order to improve various characteristics such as cohesive force. It may be. Examples of such copolymerizable monomers include vinyl esters such as methyl (meth) acrylate and vinyl acetate, aromatic vinyl compounds such as styrene and vinyltoluene, such as cyclopentyl di (meth) acrylate, and the like. (Meth) acrylic esters of cyclic alcohols such as isobornyl (meth) acrylate, eg neopentyl glycol di (meth) acrylate, hexanediol di (meth) acrylate, propylene glycol di (meth) acrylate, trimethylolpropane And (meth) acrylic acid esters of polyhydric alcohols such as tri (meth) acrylate, tetramethylolmethane tri (meth) acrylate, and dipentaerythritol hexa (meth) acrylate.

  These copolymerizable monomers are used alone or in combination as appropriate. Moreover, the compounding quantity of a copolymerizable monomer is 0-30 weight part with respect to 100 weight part of (meth) acrylic acid ester, Preferably, it is 0-15 weight part.

  The acrylic water-dispersed polymer has (meth) acrylic acid ester as the main component, and the monomer component containing the various monomers described above is not particularly limited depending on the purpose and application, but is not limited to the above. Thus, it can be obtained by emulsion polymerization.

  Emulsion polymerization may be performed by, for example, polymerizing a monomer component containing (meth) acrylic acid ester as a main component, a polymerization initiator, an emulsifier, and a chain transfer agent as necessary, in water, as appropriate. Specifically, for example, known emulsion polymerization methods such as a batch polymerization method, a continuous dropping polymerization method, and a divided dropping polymerization method can be employed. In addition, although reaction conditions etc. are selected suitably, superposition | polymerization temperature is about 20-100 degreeC, for example.

  The polymerization initiator is not particularly limited, and a known radical polymerization initiator usually used for emulsion polymerization is used. For example, 2,2′-azobisisobutyronitrile, 2,2′-azobis (2-methylpropionamidine) disulfate, 2,2′-azobis (2-amidinopropane) dihydrochloride, 2,2 ′ -Azo initiators such as azobis [2- (5-methyl-2-imidazolin-2-yl) propane] dihydrochloride, 2,2'-azobis (N, N'-dimethyleneisobutylamidine), Persulfate initiators such as potassium sulfate and ammonium persulfate, eg peroxide initiators such as benzoyl peroxide, t-butyl hydroperoxide, hydrogen peroxide, eg substituted ethane initiators such as phenyl substituted ethane Agents, for example, carbonyl initiators such as aromatic carbonyl compounds, for example, a combination of persulfate and sodium bisulfite Align, like redox initiators such as a combination of a peroxide and sodium ascorbate.

  These polymerization initiators are suitably used alone or in combination. Moreover, the compounding quantity of a polymerization initiator is about 0.005-1 weight part with respect to 100 weight part of monomer components, for example.

  The emulsifier is not particularly limited, and a known emulsifier usually used for emulsion polymerization is used. For example, sodium lauryl sulfate, ammonium lauryl sulfate, sodium dodecylbenzene sulfonate, sodium polyoxyethylene lauryl sulfate, sodium polyoxyethylene alkyl ether sulfate, ammonium polyoxyethylene alkyl phenyl ether sulfate, sodium polyoxyethylene alkyl phenyl ether sulfate, polyoxyethylene Anionic emulsifiers such as sodium alkylsulfosuccinate, for example, nonionic emulsifiers such as polyoxyethylene alkyl ether, polyoxyethylene alkylphenyl ether, polyoxyethylene fatty acid ester, polyoxyethylene polyoxypropylene block polymer, and others such as propenyl And radical polymerizable emulsifiers having a group introduced therein.

  These emulsifiers are used alone or in combination as appropriate. Moreover, the compounding quantity of an emulsifier is 0.2-10 weight part with respect to 100 weight part of monomer components, Preferably, it is about 0.5-5 weight part.

  The chain transfer agent adjusts the molecular weight of the copolymer as necessary, and a chain transfer agent usually used for emulsion polymerization is used. For example, 1-dodecanethiol, mercaptoacetic acid, 2-mercaptoethanol, And mercaptans such as 2-ethylhexyl thioglycolate and 2,3-dimethylcapto-1-propanol.

  These chain transfer agents are appropriately used alone or in combination. Moreover, the compounding quantity of a chain transfer agent is about 0.001-0.5 weight part with respect to 100 weight part of monomer components, for example.

  By such emulsion polymerization, an acrylic water-dispersed polymer containing an emulsifier and an acrylic polymer dispersed in water, that is, an adhesive component containing the emulsifier can be obtained.

  The acrylic water-dispersed polymer containing an emulsifier is, for example, such that a monomer component mainly composed of (meth) acrylic acid ester is polymerized by a method other than emulsion polymerization and then dispersed in water by the above-described emulsifier. You can also get it.

  Moreover, you may mix | blend well-known additives, such as a crosslinking agent and water dispersion type tackifying resin, with an adhesive component according to the objective and use as needed.

  As the cross-linking agent, known cross-linking agents usually used in pressure-sensitive adhesives are used, and examples thereof include isocyanate-based cross-linking agents, epoxy-based cross-linking agents, oxazoline-based cross-linking agents, aziridine-based cross-linking agents, and metal chelate-based cross-linking agents. It is done. The crosslinking agent is not particularly limited, such as oil solubility or water solubility. These crosslinking agents are appropriately used alone or in combination. The amount of the crosslinking agent is, for example, about 0.1 to 10 parts by weight with respect to 100 parts by weight of the solid content (mainly monomer component) of the adhesive component. is there.

  Examples of water-dispersed tackifying resins include rosin resins, rosin phenol resins, terpene resins, aliphatic petroleum resins, aromatic petroleum resins, copolymer petroleum resins, alicyclic petroleum resins, and xylene. Examples thereof include resins and elastomers. These water-dispersed tackifying resins can be used by being dispersed in water using an emulsifier as appropriate. Moreover, these are used individually or in combination, and the compounding quantity is about 1-100 weight part with respect to 100 weight part of solid content (mainly monomer component) of an adhesion component, for example.

  The adhesive component is preferably adjusted to a pH of, for example, 7 to 9, preferably 7 to 8, using a base such as ammonia for stabilization.

  In addition, the adhesive component is usually added to the adhesive depending on its purpose and application, such as an anti-aging agent, a filler, a pigment, a colorant, and a flame retardant other than the metal hydroxide described below. Additives may be added as appropriate.

  The solid content of the pressure-sensitive adhesive component thus obtained is, for example, the weight ratio of the residual component obtained by evaporating a solvent such as water (including volatile content) to the total weight of the pressure-sensitive adhesive component. In the case of a water-dispersed polymer or the like, it mainly comprises a monomer component (including other non-volatile components) and is, for example, 20 to 80 parts by weight, preferably 30 to 70 parts by weight with respect to 100 parts by weight of the adhesive component. Part.

  In the present invention, examples of the metal hydroxide include aluminum hydroxide, magnesium hydroxide, zinc hydroxide, silicic acid, iron hydroxide, copper hydroxide, tin hydroxide, and titanium hydroxide. Preferably, aluminum hydroxide and magnesium hydroxide are used. These metal hydroxides are used alone or in combination as appropriate.

  In addition, it is preferable that the average particle diameter of such a metal hydroxide is 20 micrometers or less. If the average particle diameter is 20 μm or less, good surface smoothness can be ensured in the formation of the adhesive layer described later. In addition, an average particle diameter is calculated | required as a median diameter when measuring with a laser scattering type particle size distribution analyzer and analyzing by refractive index 1.2.

  Moreover, the compounding quantity of a metal hydroxide is 100-300 weight part with respect to 100 weight part of solid content of an adhesion component, Preferably, it is 100-250 weight part. If it is less than 100 parts by weight, sufficient flame retardancy cannot be obtained, and if it exceeds 300 parts by weight, water activation cannot be obtained.

  And the adhesion composition of this invention can be obtained by mix | blending the adhesion component containing an above-described emulsifier, and a metal hydroxide in the above-mentioned weight ratio.

  There are no particular restrictions on blending the adhesive component and the metal hydroxide. For example, first, a metal hydroxide is dispersed in water using an emulsifier to prepare an aqueous dispersion of the metal hydroxide. Then, the aqueous dispersion may be blended with the adhesive component and mixed with stirring.

  For the preparation of the aqueous dispersion of metal hydroxide, a polymer surfactant having a carboxyl group in the molecule can be used as an emulsifier in addition to the above-mentioned emulsifier.

  As such a polymeric surfactant, it has a carboxyl group in the molecule, the carboxyl group content is 4 to 12 mmol / g, and in consideration of dispersion stability, preferably 4.2 to 8.0 mmol / g, more preferably 4.5 to 6.0 mmol / g.

  When the carboxyl group content is less than 4 mmol / g, the effect of adsorption and repulsion on the adhesive component of aluminum hydroxide cannot be imparted, resulting in poor mechanical stability. Moreover, when carboxyl group content exceeds 12 mmol / g, it will become difficult to obtain as a commercial item and it is not practical.

  The carboxyl group content of the polymer surfactant can be determined by quantification by neutralization titration.

  Examples of such polymeric surfactants include polyacrylic acid-based, polymethacrylic acid-based, acrylic acid / maleic acid copolymer systems, styrene / maleic acid copolymer systems, sulfonic acid systems, and isobutylene / maleic acid copolymers. System, polycarboxylate-based polymer surfactants and the like. Preferably, polyacrylic acid-based, polymethacrylic acid-based, acrylic acid / maleic acid copolymer system, styrene / maleic acid copolymer system polymer surfactant, more preferably polyacrylic acid system, polymethacrylic acid system, Examples thereof include polymer surfactants based on acrylic acid / maleic acid copolymers.

  In addition, as such a polymer surfactant, a commercially available product can be used. As such a commercially available product, for example, as a polyacrylic acid polymer surfactant, “AQUALIC” series manufactured by Nippon Shokubai Co., Ltd., Examples include “Aron” series manufactured by Toagosei Co., Ltd. and “Charol” series manufactured by Daiichi Kogyo Seiyaku. Examples of the polymethacrylic acid type polymer surfactant include “Primal” series manufactured by Rohm & Haas. Examples of the acrylic acid / maleic acid copolymer based polymer surfactant include “AQUALIC” series manufactured by Nippon Shokubai Co., Ltd. and “Poise” series manufactured by Kao Corporation. In addition, as a polycarboxylate polymer surfactant, “Demol” series manufactured by Kao Corporation, “SN Dispersant” series manufactured by San Nopco, “Nopco Santo” series, “Nopcos Perth” series, “Adeka Coal” series manufactured by Asahi Denka Co., Ltd. Etc.

  More specifically, as the polyacrylic acid polymer surfactant, for example, “Aquaric DL-40” (carboxyl group content: 9.2 mmol / g) manufactured by Nippon Shokubai Co., Ltd. 365 "(carboxyl group content 9.1 mmol / g), Nippon Shokubai" Aquaric DL-453 "(carboxyl group content 9.3 mmol / g), Nippon Shokubai" Aquaric DL-522 "(carboxyl group content 9.1 mmol / g), “Aron A-20U” manufactured by Toagosei Co., Ltd. (carboxyl group content 8.9 mmol / g), “Aron A-208” manufactured by Toagosei Co., Ltd. (carboxyl group content 6.5 mmol / g), Toago “Aron A-30SL” (carboxyl group content: 9.8 mmol / g) manufactured by Synthetic Co., Ltd. “Charol AN-103P” (Carbo) Sill group content 8.4 mmol / g), "Shallol AH-103P" (carboxyl group content 7.8 mmol / g) and the like. Examples of the polymethacrylic acid polymer surfactant include “Primal 850-FF” (carboxyl group content: 7.8 mmol / g) manufactured by Rohm & Haas. Examples of the acrylic acid / maleic acid copolymer based polymer surfactant include “AQUALIC TL-37” (carboxyl group content 6.4 mmol / g), “AQUALIC TL-213” (carboxyl) manufactured by Nippon Shokubai Co., Ltd. Group content 6.7 mmol / g), Nippon Shokubai Co., Ltd. “AQUALIC TL-300” (carboxyl group content 7.2 mmol / g), Kao Corporation “Poise 521” (carboxyl group content 4.7 mmol / g), “ Poise 530 ”(carboxyl group content 8.5 mmol / g) and“ Poise 532A ”(carboxyl group content 7.9 mmol / g) manufactured by Kao Corporation. Examples of the polycarboxylate-based polymer surfactant include “Demol P” (carboxyl group content: 9.1 mmol / g) manufactured by Kao Corporation and “Demol ST” (carboxyl group content: 4.0 mmol / g) manufactured by Kao Corporation. ), “SN Dispersant 5468” (carboxyl group content 5.9 mmol / g) manufactured by San Nopco, “SN Dispersant 5034” (carboxyl group content 7.0 mmol / g) manufactured by San Nopco, “SN Dispersant 5041 manufactured by San Nopco (Carboxyl group content: 8.8 mmol / g), San Nopco “SN Dispersant 5045” (carboxyl group content: 5.7 mmol / g), Sannopco “Nopcosanto R” (carboxyl group content: 8.3 mmol / g), Sannopco's “Nopcosperth 44-C” (carboxyl Content 8.6mmol / g), Asahi Denka Co., Ltd., "Adekacol W-304" (a carboxyl group content of 8.0mmol / g), and the like.

  The compounding quantity of an emulsifier is 0.01-10 weight part with respect to 100 weight part of metal hydroxides, Preferably, it is 0.1-5 weight part. Moreover, the compounding quantity of water is 10-1000 weight part with respect to 100 weight part of metal hydroxides, Preferably, it is 20-100 weight part.

  The aqueous dispersion of metal hydroxide can be prepared by appropriately mixing a metal hydroxide and an emulsifier in water and stirring and mixing them.

  Then, the pressure-sensitive adhesive composition of the present invention is obtained by blending the aqueous dispersion of the metal hydroxide thus prepared in the above-mentioned pressure-sensitive adhesive component and stirring and mixing.

  In the present invention, in this way, when the metal hydroxide is prepared as an aqueous dispersion containing an emulsifier, and the aqueous dispersion is mixed with the adhesive component, the adhesive component contains an emulsifier in advance. It does not have to be.

  Since the pressure-sensitive adhesive composition of the present invention thus obtained contains a pressure-sensitive adhesive component, an emulsifier, and a metal hydroxide, the coexistence of the emulsifier and the metal hydroxide exhibits adhesiveness in the presence of water. It is possible to obtain a water activation activity. Therefore, in the pressure-sensitive adhesive composition of the present invention, even if the compounding amount of the metal hydroxide is increased so that the effect of imparting flame retardancy is sufficiently manifested by the expression of such water-hydrating activity, excellent adhesion Sex can be expressed. In addition, since the metal hydroxide is excellent in environmental safety, when only the metal hydroxide is blended as a flame retardant in the pressure-sensitive adhesive composition of the present invention, further improvement in environmental safety is intended. Can do.

  Therefore, the pressure-sensitive adhesive sheet of the present invention comprising the pressure-sensitive adhesive layer made of the pressure-sensitive adhesive composition of the present invention is an adhesive sheet excellent in both flame retardancy and pressure-sensitive adhesive properties in various fields such as electronic devices, home appliances, vehicles, and housing construction materials. Used effectively.

  Next, an embodiment of the pressure-sensitive adhesive sheet of the present invention will be described with reference to FIG.

  In FIG. 1, the pressure-sensitive adhesive sheet 1 has a pressure-sensitive adhesive layer 2 made of the above-described pressure-sensitive adhesive composition of the present invention laminated on a substrate 3.

  The substrate 3 is not particularly limited, and a substrate usually used for an adhesive sheet is used. For example, plastic films such as a polypropylene film, an ethylene-propylene copolymer film, a polyester film, and polyvinyl chloride, for example, Paper such as kraft paper, for example, cloth such as cotton cloth and sufu cloth, for example, non-woven cloth such as polyester non-woven fabric and vinylon non-woven fabric, for example, metal foil and the like are used. In addition, as the plastic film, any of an unstretched film and a stretched (uniaxially stretched or biaxially stretched) film can be used. Moreover, in the base material 3, the surface treatment by the undercoat process of the normally used primer, the corona discharge system etc. may be given to the application surface of the adhesion composition. Although the thickness of the base material 3 is suitably selected according to the purpose, use, etc., it is about 10-500 micrometers, for example.

  In order to laminate | stack the adhesion layer 2 which consists of an adhesion composition of this invention on the base material 3, it does not restrict | limit, What is necessary is just to apply | coat the adhesion composition of this invention on the base material 3, and heat-dry. For the application, a known coating method is used. For example, the adhesive composition of the present invention is applied onto the substrate 3 using a coater, and then dried by heating, whereby the adhesive composition of the present invention is adhered. The layer 2 can be stacked.

  The coater is not particularly limited. For example, a coater usually used for laminating the adhesive layer 2 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 is used. It is done.

  Moreover, in application | coating by such a coater, it applies so that the thickness of the adhesion layer 2 after drying may be set to about 10-100 micrometers, for example.

  Next, the adhesive layer 2 is formed by heating. The heating is performed by a known method, for example, at 50 to 200 ° C., preferably about 80 to 160 ° C.

  The pressure-sensitive adhesive sheet 1 is not particularly limited. For example, the pressure-sensitive adhesive sheet 1 is obtained by laminating the pressure-sensitive adhesive layer 2 on the substrate 3 as described above and, if necessary, further sticking the release liner 4 and then winding it. be able to. The release liner 4 is not particularly limited, and a release liner usually used for an adhesive sheet is used. For example, a release agent made of a silicone release agent is laminated on one side or both sides of a thin-leaf base material. Etc. are used. Moreover, the thickness in particular is although it does not restrict | limit, For example, it is 15 micrometers or more, Preferably, it is about 25-500 micrometers.

  More specifically, as shown in FIG. 1, the pressure-sensitive adhesive sheet 1 is formed by laminating the pressure-sensitive adhesive layer 2 on one side of the base material 3, attaching a release liner 4 to the pressure-sensitive adhesive layer 2, and winding it. Can be obtained by:

  In the above method, the pressure-sensitive adhesive layer 2 is laminated on the release liner 4 by applying the pressure-sensitive adhesive composition of the present invention on the release liner 4 and drying it by heating. You may stick on the material 3.

  Further, for example, as shown in FIG. 2, the adhesive layer 2 is laminated on both surfaces of the base material 3, and the liner 4 is adhered to each adhesive layer 2 laminated on both surfaces of the base material 3. It can also be obtained by turning.

  Also in this case, the adhesive composition of the present invention is applied onto each release liner 4 in the same manner as described above, followed by heating and drying, thereby laminating the adhesive layers 2. The base material 3 may be attached to both surfaces.

  The pressure-sensitive adhesive sheet of the present invention is used in various forms such as a tape, a sheet, and a film regardless of the above forms, and can be stored and maintained in various forms depending on the purpose and application without winding. Can be used.

  Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples. However, the present invention is not limited to the following examples and comparative examples. In the following description, “parts” and “%” are based on weight unless otherwise specified.

Production Example 1 (Preparation of acrylic water-dispersed polymer)
In 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-methacryloxypropyltrimethoxysilane (KBM-503, Shin-Etsu Silicone Co., Ltd.) 0.05 part, 2,2′-azobis [2- (5-methyl-2-imidazolin-2-yl) propane] dihydrochloride 0.1 part, 1-dodecanethiol 0.05 part Was added to 100 parts of water to which 2.0 parts of sodium polyoxyethylene lauryl sulfate was added and polymerized at 60 ° C. for 7 hours. After polymerization, 10% aqueous ammonia was added to adjust the pH to 8, thereby obtaining an acrylic water-dispersed polymer.

Production Example 2 (Preparation of aqueous aluminum hydroxide dispersion)
Water 45 to which 100 parts of aluminum hydroxide (average particle size 1.2 μm, BF013, manufactured by Nippon Light Metal Co., Ltd.) and 2 parts of acrylic acid / maleic acid copolymer polymer surfactant (Poise 521, manufactured by Kao Corporation) were added In addition to the parts, the mixture was stirred at 3000 min ⁻¹ for 10 minutes with a high-speed stirrer to obtain an aqueous aluminum hydroxide dispersion.

Production Example 3 (Preparation of acrylic solvent-based polymer)
Add 70 parts of butyl acrylate, 30 parts of 2-ethylhexyl acrylate, 3 parts of acrylic acid, 0.2 part of benzoyl peroxide, and 100 parts of toluene to a reaction vessel equipped with a cooling tube, a nitrogen introduction tube, a thermometer and a stirrer. And polymerized at 60 ° C. for 7 hours to obtain an acrylic solvent-type polymer.

Example 1
To the acrylic water-dispersed polymer obtained in Production Example 1, an aluminum hydroxide aqueous dispersion is blended at a weight ratio of 100 parts of aluminum hydroxide to 100 parts of the solid content of the acrylic water-dispersed polymer. The pressure-sensitive adhesive composition was obtained by mixing.

  The obtained pressure-sensitive adhesive composition was applied to one side (release agent application surface) of a release liner (thickness 135 μm, SLB-80W5D, manufactured by Kite Chemical Industries, Ltd.) to which a silicone release agent was applied. It was dried for minutes to form an adhesive layer having a thickness of 70 μm. Subsequently, the double-sided adhesive sheet (refer FIG. 2) was obtained by sticking the obtained adhesion layer on both surfaces of a nonwoven fabric (PR-14, Nippon Paperboard Co., Ltd.).

Example 2
To the acrylic water-dispersed polymer obtained in Production Example 1, an aluminum hydroxide aqueous dispersion is blended in a weight ratio of 150 parts of aluminum hydroxide with respect to 100 parts of the solid content of the acrylic water-dispersed polymer. The pressure-sensitive adhesive composition was obtained by mixing.

  Then, the double-sided adhesive sheet (refer FIG. 2) was obtained by the method similar to Example 1. FIG.

Comparative Example 1
Without blending the aluminum hydroxide aqueous dispersion obtained in Production Example 2, using only the acrylic water-dispersed polymer obtained in Production Example 1 as the adhesive composition, the same method as in Example 1, A double-sided adhesive sheet (see FIG. 2) was obtained.

Comparative Example 2
To the acrylic water-dispersed polymer obtained in Production Example 1, an aluminum hydroxide aqueous dispersion is blended at a weight ratio of 50 parts of aluminum hydroxide to 100 parts of the solid content of the acrylic water-dispersed polymer. The pressure-sensitive adhesive composition was obtained by mixing.

  Then, the double-sided adhesive sheet (refer FIG. 2) was obtained by the method similar to Example 1. FIG.

Comparative Example 3
To the acrylic water-dispersed polymer obtained in Production Example 1, an aluminum hydroxide aqueous dispersion is blended at a weight ratio of 400 parts of aluminum hydroxide to 100 parts of the solid content of the acrylic water-dispersed polymer. The pressure-sensitive adhesive composition was obtained by mixing.

  Then, the double-sided adhesive sheet (refer FIG. 2) was obtained by the method similar to Example 1. FIG.

Comparative Example 4
Into the acrylic solvent-based polymer obtained in Production Example 3, an aqueous aluminum hydroxide dispersion is blended at a weight ratio of 150 parts of aluminum hydroxide with respect to 100 parts of the solid content of the acrylic solvent-based polymer. After stirring and mixing for 10 minutes at 3000 min ⁻¹ with a stirrer, an adhesive composition was obtained by adding 2 parts of an isocyanate-based crosslinking agent (Coronate L, manufactured by Nippon Polyurethane Co., Ltd.).

  Then, the double-sided adhesive sheet (refer FIG. 2) was obtained by the method similar to Example 1. FIG.

Evaluation 1) Oxygen index About the double-sided adhesive sheet obtained in each Example and each comparative example, the oxygen index was measured based on JIS K7201. The results are shown in Table 1. The oxygen index was 25 or more.
2) Normal-state adhesive strength The double-sided adhesive tape obtained in each Example and each Comparative Example was attached to one side of a polyester film (Lumirror S-10, # 38, manufactured by Toray Industries, Inc.), and then 20 mm in width and length. A test piece was prepared by cutting to 100 mm.

Next, each test piece is pressure-bonded to one side of a polypropylene plate so that a rubber roller having a weight of 2 kg is reciprocated once, left at 23 ° C. for 30 minutes, and then peeled off in an atmosphere of 23 ° C. and 65% RH. The normal state adhesive force was determined by measuring the force (180 degree peel, peeling speed 300 mm / min). The results are shown in Table 1.
3) Adhesive strength under humidity The double-sided adhesive tape obtained in each Example and each Comparative Example was attached to one side of a polyester film (Lumirror S-10, # 38, manufactured by Toray Industries, Inc.), and then 20 mm wide and long The specimen was cut to a length of 100 mm.

  Next, each test piece was pressed against one side of a polypropylene plate by reciprocating a rubber roller having a weight of 2 kg, and left at 40 ° C. and 92% RH for 7 days. Thereafter, each test piece is taken out, left in a 23 ° C., 65% RH atmosphere for 60 minutes, and then the force required for peeling in the same atmosphere is measured (180 ° peel, peeling speed 300 mm / min) to determine the humidity. The lower adhesive strength was determined. The results are shown in Table 1. The adhesive strength under humidity was determined to be 5 N / 20 mm or more.

  As shown in Table 1, each example shows good results in all of the oxygen index, the normal state adhesive force, and the adhesive force under humidity. On the other hand, it can be seen that each of the comparative examples is defective in any of the oxygen index, the normal state adhesive force, and the adhesive force under humidity.

  That is, in Comparative Example 1 in which the metal oxide is not blended, the oxygen index and the adhesive strength under humidity are poor, and in Comparative Example 2 in which the amount of the metal oxide is small, the oxygen index is poor, and the blend of the metal oxide It can be seen that Comparative Example 3 with a large amount has poor adhesive strength under humidity, and Comparative Example 4 in which no emulsifier is blended has poor adhesive strength under humidity.

It is sectional drawing which shows typically one Embodiment (The aspect by which the adhesion layer is laminated | stacked on the single side | surface of a base material, and the liner was stuck to the adhesion layer) of this invention. Sectional drawing which shows typically other embodiment (The aspect by which the adhesive layer is laminated | stacked on both surfaces of a base material, and the state wound by the state in which the release liner was stuck on both adhesive layers) of this invention. It is.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Adhesive sheet 2 Adhesive layer 3 Base material 4 Release liner

Claims (6)

Contains adhesive components, emulsifiers and metal hydroxides,
The pressure-sensitive adhesive composition comprising the metal hydroxide in a proportion of 100 to 300 parts by weight with respect to 100 parts by weight of the solid content of the pressure-sensitive adhesive component. An adhesive component containing an emulsifier and a metal hydroxide,
The pressure-sensitive adhesive composition comprising the metal hydroxide in a proportion of 100 to 300 parts by weight with respect to 100 parts by weight of the solid content of the pressure-sensitive adhesive component. The pressure-sensitive adhesive composition according to claim 1 or 2, wherein the metal hydroxide is aluminum hydroxide and / or magnesium hydroxide. The pressure-sensitive adhesive composition according to claim 1, wherein the pressure-sensitive adhesive component contains an acrylic polymer as a main component. The acrylic polymer is obtained by emulsion polymerization of a monomer component mainly composed of (meth) acrylic acid alkyl ester with the emulsifier,
The pressure-sensitive adhesive composition according to claim 4, wherein the pressure-sensitive adhesive component contains a water-dispersed polymer in which the acrylic polymer is dispersed in water. An adhesive sheet comprising an adhesive layer made of the adhesive composition according to claim 1.

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