JP2010144043A - Uv ray-curable viscoelastic material, uv ray-curable pressure-sensitive adhesive tape or sheet, and method for producing uv ray-curable viscoelastic material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a UV ray-curable viscoelastic material having a high polymerization rate and concealing property, a UV ray-curable pressure-sensitive adhesive tape or sheet, and a method of producing a UV ray-curable viscoelastic material. <P>SOLUTION: The UV ray-curable viscoelastic material contains a thermochromic pigment that reversibly decolors and colors by temperature changes. In particular, a preferable UV ray-curable viscoelastic material is obtained by polymerizing a UV ray-polymerizable composition through irradiation with UV rays, the composition containing 70 to 99.9 parts by weight of an alkyl (meth)acrylate having an alkyl group having 2 to 20 carbon atoms, 0.1 to 30 parts by weight of a vinyl monomer, in total 100 parts by weight of the monomer component, and 0.01 to 30 parts by weight of a thermochromic pigment and 0.01 to 5.0 parts by weight of a photopolymerization initiator. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a thermochromic pigment that reversibly loses color and develops color when temperature changes. Specifically, it is a thermochromic pigment that is colored at room temperature but is decolored by increasing the temperature during UV curing and transmits UV rays. The present invention relates to an ultraviolet curable viscoelastic body, an ultraviolet curable adhesive tape or sheet, and a method for producing the ultraviolet curable viscoelastic body.

  Conventionally, ultraviolet curable viscoelastic bodies have been widely applied because of their rapid polymerizability by ultraviolet rays. Depending on the application, it is desirable to conceal the presence of this ultraviolet curable viscoelastic body, and moreover, it is more desirable to be colored black.

  However, when a sufficient amount of a pigment such as carbon black is added in order to make the appearance of the ultraviolet curable viscoelastic body a desired black color, the pigment interferes with the ultraviolet ray and causes poor curing.

In order to solve the problems such as poor curing described above, in Patent Document 1 below, a pressure-sensitive adhesive material, in particular, a vinyl-based monomer having a (meth) acrylate having 1 to 14 carbon atoms as a main component or its An acrylic pressure-sensitive adhesive composition comprising a partially polymerized product, a photopolymerizable pressure-sensitive adhesive material containing a photopolymerization initiator, and a heat discoloring agent that changes color irreversibly by heating is disclosed. Patent Document 2 below discloses a sealing adhesive tape having a material that changes color irreversibly. Furthermore, in the following Patent Document 3, a reversible thermochromic laminate containing an acrylic material is disclosed. However, even if it is what is disclosed in any of the above-mentioned patent documents, there is a limit to satisfying both a sufficient polymerization rate of the acrylic material and a shielding property such as a laminate, and there is room for further improvement.
JP 2004-175978 A JP 2006-293938 A JP 2002-127287 A

  The present invention has been made in view of various problems in the above-described conventional acrylic pressure-sensitive adhesive sheet, and has a high polymerization rate and a concealment ultraviolet-curable viscoelastic body, ultraviolet-curable pressure-sensitive adhesive tape or sheet. And a method for producing an ultraviolet curable viscoelastic body.

  The inventors of the present invention have made extensive studies in order to achieve the above object, and are ultraviolet curable viscoelastic bodies characterized by containing a thermochromic pigment that reversibly loses color and develops color due to temperature changes. Can be erased from dark to transparent by heat such as curing heat (polymerization heat) and radiant heat generated during UV irradiation, can be cured quickly without hindering UV rays, and has concealment in the normal temperature range. The present inventors have found that it is possible to provide a UV curable viscoelastic body that has been provided.

  In the ultraviolet curable viscoelastic body, the temperature at which the thermochromic pigment is reversibly decolored and colored is preferably in the range of 30 to 100 ° C.

  If the temperature for decolorization and color development is less than 30 ° C, the hue of the elastic body may change during use in a normal environment. If it exceeds 100 ° C, heating during ultraviolet irradiation is required. The cost may increase.

  In the ultraviolet curable viscoelastic body, the transmittance at 25 ° C. is 30% or less in the wavelength region of 400 to 500 nm, the transmittance value increases as the temperature rises, and the transmittance at a temperature exceeding 30 ° C. However, it is preferable that it is 10% or more in a 400-500 nm wavelength range.

  When the transmittance at 25 ° C. exceeds 30% in the wavelength region of 400 to 500 nm, the coloring effect of the thermochromic pigment, particularly the blackening effect, may be reduced. When the obtained transmittance is less than 10% in the wavelength region of 400 to 500 nm, the transmittance is not sufficient, and a large amount of energy may be required to completely cure the ultraviolet curable viscoelastic body. is there.

  The ultraviolet curable viscoelastic body is prepared by adding 100 to 9 parts by weight of a monomer component containing 70 to 99.9 parts by weight of an alkyl (meth) acrylate having 2 to 20 carbon atoms and 0.1 to 30 parts by weight of a vinyl monomer. On the other hand, it is obtained by polymerizing an ultraviolet polymerizable composition containing 0.01 to 30 parts by weight of the thermochromic pigment and 0.01 to 5.0 parts by weight of a photopolymerization initiator by ultraviolet irradiation. Is preferred.

  The UV curable viscoelastic body obtained by polymerizing the above UV polymerizable composition by UV irradiation has a particularly high concealment property and a high monomer component polymerization rate, and further has adhesive properties and heat resistance. Excellent in properties.

  The ultraviolet curable viscoelastic body preferably contains 0.001 to 30 parts by weight of a polyfunctional (meth) acrylate with respect to 100 parts by weight of the monomer component.

  The ultraviolet curable viscoelastic body obtained by polymerizing the above ultraviolet polymerizable composition by irradiating with ultraviolet rays retains good cohesive force due to its crosslinking effect, and is particularly excellent in heat resistance.

  In the ultraviolet curable viscoelastic body, it is preferable that 0.5 to 20 parts by weight of fine particles are further contained with respect to 100 parts by weight of the monomer component.

  Furthermore, by containing the predetermined amount of fine particles, the shear adhesive force in the ultraviolet curable viscoelastic body can be increased, and the workability can be improved.

  The ultraviolet curable pressure-sensitive adhesive tape or sheet according to the present invention is composed of any one of the above-mentioned ultraviolet curable viscoelastic bodies, or the ultraviolet curable viscoelastic body according to any one of the above is at least a base material. It is on one side.

  As described above, since the ultraviolet curable viscoelastic body according to the present invention has high concealment and a high polymerization rate of the monomer component, the ultraviolet curable adhesive tape or sheet provided with this ultraviolet curable viscoelastic body. Similarly, the concealability is high and the polymerization rate of the monomer component is high.

  The method for producing an ultraviolet curable viscoelastic material according to the present invention includes 70 to 99.9 parts by weight of an alkyl (meth) acrylate having an alkyl group having 2 to 20 carbon atoms and 0.1 to 30 parts by weight of a vinyl monomer. An ultraviolet polymerizable composition containing 0.01 to 30 parts by weight of the thermochromic pigment and 0.01 to 5.0 parts by weight of a photopolymerization initiator with respect to 100 parts by weight of the monomer component is irradiated with ultraviolet rays. A curable viscoelastic body is formed.

  According to the above method for producing an ultraviolet curable viscoelastic material, an ultraviolet curable viscoelastic material having a particularly high concealment property and a high polymerization rate of the monomer component, and further excellent in adhesive properties and heat resistance is produced. can do.

  In the method for producing an ultraviolet curable viscoelastic body, the ultraviolet polymerizable composition preferably further contains 0.001 to 30 parts by weight of a polyfunctional (meth) acrylate with respect to 100 parts by weight of the monomer component.

  The ultraviolet curable viscoelastic body obtained by polymerizing the above ultraviolet polymerizable composition by irradiating with ultraviolet rays retains good cohesive force due to its crosslinking effect, and is particularly excellent in heat resistance.

In the method for producing an ultraviolet curable viscoelastic body, it is preferable to form an ultraviolet curable viscoelastic body by irradiating ultraviolet rays having an intensity of 1 to 50 mW / cm ² at a wavelength of 300 to 400 nm.

If the illuminance of the ultraviolet rays is higher than 50 mW / cm ² , the molecular weight of the polymer to be produced may be reduced, and sufficient adhesive properties may not be obtained. If it is lower than 1 mW / cm ² , until the desired adhesive is obtained. In some cases, the UV irradiation time required for the process is significantly increased.

  The ultraviolet curable viscoelastic body according to the present invention is characterized by containing a thermochromic pigment that reversibly loses color and develops color when temperature changes. Particularly, the ultraviolet curable viscoelastic body has a monomer component of 100 parts by weight containing 70 to 99.9 parts by weight of an alkyl (meth) acrylate having an alkyl group having 2 to 20 carbon atoms and 0.1 to 30 parts by weight of a vinyl monomer. In contrast, 0.01 to 30 parts by weight of a thermochromic pigment and 0.01 to 5.0 parts by weight of a photopolymerization initiator, preferably 0.001 to 0.001 of a polyfunctional (meth) acrylate. It is preferable that it is obtained by polymerizing an ultraviolet polymerizable composition containing 30 parts by weight with ultraviolet irradiation. Hereinafter, the ultraviolet curable viscoelastic body according to the present invention will be described.

(Alkyl (meth) acrylate having an alkyl group having 2 to 20 carbon atoms)
Examples of the alkyl (meth) acrylate having an alkyl group having 2 to 20 carbon atoms include an ethyl group, a propyl group, a butyl group, an amyl group, a hexyl group, a heptyl group, a 2-ethylhexyl group, an isooctyl group, an isononyl group, An isodecyl group, a dodecyl group, a lauryl group, a tridecyl group, a tetradecyl group, a pentadecyl group, a hexadecyl group, a heptadecyl group, an octadecyl group, a nonadecyl group, an eicosyl group, and more preferably a straight chain having 4 to 18 carbon atoms. Examples thereof include those using one or more esters of acrylic or methacrylic esters having a chain or branched alkyl group.

  Moreover, there is no limitation in particular as a vinyl monomer, What is necessary is just to be copolymerizable with the said alkyl (meth) acrylate which has a C2-C20 alkyl group.

(Vinyl monomer)
Examples of the vinyl monomer include (meth) acrylic acid, carboxyethyl (meth) acrylate, carboxypentyl (meth) acrylate, itaconic acid, maleic acid, fumaric acid, crotonic acid and other carboxyl group-containing monomers; maleic anhydride, Acid anhydride monomers such as itaconic anhydride; 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, Hydroxy group-containing monomers such as 8-hydroxyoctyl (meth) acrylate, 10-hydroxydecyl (meth) acrylate, 12-hydroxylauryl (meth) acrylate, (4-hydroxymethylcyclohexyl) methyl (meth) acrylate; styrene Sulfo Sulfone group-containing monomers such as acid, allyl sulfonic acid, 2- (meth) acrylamide-2-methylpropane sulfonic acid, (meth) acrylamide propane sulfonic acid, sulfopropyl (meth) acrylate, (meth) acryloyloxynaphthalene sulfonic acid; Phosphoric acid group-containing monomers such as 2-hydroxyethyl acryloyl phosphate; Amide monomers such as (meth) acrylamide, N-methylol acrylamide and acryloylmorpholine; N- (meth) acryloyloxymethylene succinimide, N- (meth) acryloyl-6 -Succinimide monomers such as oxyhexamethylene succinimide and N- (meth) acryloyl-8-oxyoctamethylene succinimide; vinyl acetate, N-vinylpyrrolidone, N-vinyl Vinyl monomers such as carboxylic acid amide, styrene, N-vinylcaprolactam; acrylonitrile, methacrylonitrile, glycidyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, polyethylene glycol (meth) acrylate, polypropylene glycol (meth) acrylate , Acrylic ester monomers such as fluorine (meth) acrylate, silicone (meth) acrylate and 2-methoxyethyl acrylate; monomers having an alicyclic structure such as cyclohexyl (meth) acrylate and isobornyl acrylate; methyl (meth) Examples thereof include alkyl (meth) acrylates having an alkyl group other than an alkyl group having 2 to 20 carbon atoms (an alkyl group having 1 or 20 carbon atoms) such as acrylate. Can.

  In the monomer component, the ratio of the (meth) acrylate having 2 to 20 carbon atoms in the alkyl group and the vinyl monomer having a polar group is preferably the former: the latter (parts by weight) = 70 to 99.9: It is 0.1-30 (weight part), More preferably, it is 75-99.5: 0.5-25 (weight part), More preferably, it is 80-99.0: 1.0-20 (weight part). Within these ranges, it is preferable in terms of adhesive properties to adjust the vinyl monomer.

(Multifunctional (meth) acrylate)
Examples of the polyfunctional (meth) acrylate include hexanediol di (meth) acrylate, (poly) ethylene glycol di (meth) acrylate, (poly) propylene glycol di (meth) acrylate, and neopentyl glycol di (meth) acrylate. , Pentaerythritol di (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, trimethylolpropane tri (meth) acrylate, tetramethylol methanetri (meth) Acrylate, aryl (meth) acrylate, vinyl (meth) acrylate, divinylbenzene, epoxy acrylate, polyester acrylate, urethane acrylate, Tildi (meth) acrylate, hexyldi (meth) acrylate, trimethylolpropane tri (meth) acrylate, 1,2-ethylene glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, 1,12-dodecane Examples thereof include diol di (meth) acrylate.

  The amount of the polyfunctional (meth) acrylate used is preferably 0.001 to 30 parts by weight, more preferably 0.05 to 100 parts by weight of the monomer component for preparing the ultraviolet curable viscoelastic body. ~ 20 parts by weight. When the amount of polyfunctional (meth) acrylate used exceeds 30 parts by weight with respect to the total amount of monomer components for preparing an ultraviolet curable viscoelastic body, for example, the cohesive force of the ultraviolet curable adhesive tape or sheet increases. Too much pressure-sensitive adhesiveness may be reduced. On the other hand, when the amount of the polyfunctional (meth) acrylate used is, for example, less than 0.001 part by weight based on the total amount of monomer components for preparing the ultraviolet curable viscoelastic body, the ultraviolet curable adhesive tape or sheet Cohesive force is reduced. By using polyfunctional (meth) acrylate at such a ratio, a good cohesive force is maintained due to the crosslinking effect on the ultraviolet curable viscoelastic body, and high heat resistance can be obtained.

(Thermochromic pigment)
The thermochromic pigment that is reversibly decolored and colored by temperature change used in the present invention is decolored (preferably becomes colorless and transparent) by heating such as ultraviolet irradiation, and is colored when used at room temperature. It is a pigment (colored). The color at the time of coloring the thermochromic pigment is more preferably black in terms of concealment.

  The temperature at which the thermochromic pigment is reversibly decolored and developed, that is, the temperature at which it is discolored (hereinafter referred to as “discoloring temperature”) is preferably in the range of 30 to 100 ° C. If the discoloration temperature is less than 30 ° C., the hue of the elastic body may change when used in a normal environment. If the discoloration temperature exceeds 100 ° C., heating during ultraviolet irradiation is required, resulting in an increase in cost. There is a case. The “discoloration temperature” is a value of L * measured by measuring L * from a low temperature (usually 20 ° C. or less) according to the darkness measurement method described later, and leaving the viscoelastic body for 5 minutes at the temperature after the temperature increase. Indicates a temperature that changes by 10% or more from the initial low temperature value.

  The thermochromic pigment of the present invention is preferably added in an amount of 0.01 to 30 parts by weight, more preferably 0.02 to 20 parts by weight, and still more preferably 0.03 to 10 parts by weight. If the amount to be added is less than 0.01 parts by weight, the effect of blackening by the thermochromic pigment is reduced. On the other hand, if it exceeds 30 parts by weight, the color-changing effect by the thermochromic pigment is reduced.

  Although the specific example of a thermochromic pigment is not restrict | limited in particular, The microencapsulated thing which changes color rapidly with temperature can be used conveniently. For example, the product name “temperature reaction capsule” (manufactured by Chemitech Co., Ltd.), the product name “Thermo lock 48”, “Thermo lock 72”, “Thermo lock 79” (manufactured by Matsui Pigment Chemical Industry Co., Ltd.), the product name “ST” Color "(manufactured by Kuboti Ink Co., Ltd.) is used.

  By using the thermochromic pigment of the present invention, the transmittance at 25 ° C. is 30% or less in the wavelength region of 400 to 500 nm, the transmittance value increases as the temperature rises, and the transmittance at 30 ° C. or higher. An ultraviolet curable viscoelastic body having a rate of 10% or more in a wavelength region of 400 to 500 nm can be obtained.

  When the transmittance at 25 ° C. exceeds 30% in the wavelength region of 400 to 500 nm, the blackening effect of the thermochromic pigment is reduced, while the transmittance whose value is increased by the temperature rise is 400 to 500 nm. If it is less than 10% in the wavelength region, sufficient transmittance is not obtained, and a great amount of energy is required to completely cure the ultraviolet curable viscoelastic body. In order to exhibit the blackening effect of the thermochromic pigment more effectively, the transmittance at 25 ° C. is preferably 25% or less in the wavelength region of 400 to 500 nm, and preferably 15% or less. More preferably, it is 5% or less. Further, in order to cure the UV curable viscoelastic body more surely, the transmittance having a larger value due to the temperature rise, for example, the transmittance at 90 ° C. is 20% or more in the wavelength region of 400 to 500 nm. It is preferably 25% or more, more preferably 40% or more.

(Photopolymerization initiator)
The photopolymerization initiator is not particularly limited. For example, acylphosphine photopolymerization initiator, acetophenone photopolymerization initiator, benzoin ether photopolymerization initiator, α-ketol photopolymerization initiator, aromatic Sulfonyl chloride photoinitiator, photoactive oxime photoinitiator, benzoin photoinitiator, benzyl photoinitiator, benzophenone photoinitiator, ketal photoinitiator, thioxanthone photoinitiator An optical radical polymerization initiator such as an agent can be used.

  Examples of the acylphosphine photopolymerization initiator include bis (2,6-dimethoxybenzoyl) phenylphosphine oxide, bis (2,6-dimethoxybenzoyl) (2,4,4-trimethylpentyl) phosphine oxide, Bis (2,6-dimethoxybenzoyl) -n-butylphosphine oxide, bis (2,6-dimethoxybenzoyl)-(2-methylpropan-1-yl) phosphine oxide, bis (2,6-dimethoxybenzoyl) -(1-methylpropan-1-yl) phosphine oxide, bis (2,6-dimethoxybenzoyl) -t-butylphosphine oxide, bis (2,6-dimethoxybenzoyl) cyclohexylphosphine oxide, bis (2, 6-Dimethoxybenzoyl) octylfo Fin oxide, bis (2-methoxybenzoyl) (2-methylpropan-1-yl) phosphine oxide, bis (2-methoxybenzoyl) (1-methylpropan-1-yl) phosphine oxide, bis (2,6 -Diethoxybenzoyl) (2-methylpropan-1-yl) phosphine oxide, bis (2,6-diethoxybenzoyl) (1-methylpropan-1-yl) phosphine oxide, bis (2,6-di) Butoxybenzoyl) (2-methylpropan-1-yl) phosphine oxide, bis (2,4-dimethoxybenzoyl) (2-methylpropan-1-yl) phosphine oxide, bis (2,4,6-trimethylbenzoyl) ) (2,4-dipentoxyphenyl) phosphine oxide, bis (2, -Dimethoxybenzoyl) benzylphosphine oxide, bis (2,6-dimethoxybenzoyl) -2-phenylpropylphosphine oxide, bis (2,6-dimethoxybenzoyl) -2-phenylethylphosphine oxide, bis (2,6- Dimethoxybenzoyl) benzylphosphine oxide, bis (2,6-dimethoxybenzoyl) -2-phenylpropylphosphine oxide, bis (2,6-dimethoxybenzoyl) -2-phenylethylphosphine oxide, 2,6-dimethoxybenzoylbenzyl Butylphosphine oxide, 2,6-dimethoxybenzoylbenzyloctylphosphine oxide, bis (2,4,6-trimethylbenzoyl) -2,5-diisopropylphenylphosphine Oxide, bis (2,4,6-trimethylbenzoyl) -2-methylphenylphosphine oxide, bis (2,4,6-trimethylbenzoyl) -4-methylphenylphosphine oxide, bis (2,4,6- Trimethylbenzoyl) -2,5-diethylphenylphosphine oxide, bis (2,4,6-trimethylbenzoyl) -2,3,5,6-tetramethylphenylphosphine oxide, bis (2,4,6-trimethyl) Benzoyl) -2,4-di-n-butoxyphenylphosphine oxide, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis (2,6-dimethoxybenzoyl) -2,4,4-trimethylpentylphenylphosphine Fin oxide, bis (2,4,6-trimethylbenzene) Zoyl) isobutylphosphine oxide, 2,6-dimethoxybenzoyl-2,4,6-trimethylbenzoyl-n-butylphosphine oxide, bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide, bis (2, 4,6-trimethylbenzoyl) -2,4-dibutoxyphenylphosphine oxide, 1,10-bis [bis (2,4,6-trimethylbenzoyl) phosphine oxide] decane, tri (2-methylbenzoyl) phos And fin oxides. Among these, bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide, bis (2,4,6-trimethylbenzoyl) -2,4-di-n-butoxyphenylphosphine oxide, 2,4 , 6-trimethylbenzoyldiphenylphosphine oxide and bis (2,6-dimethoxybenzoyl) -2,4,4-trimethylpentylphenylphosphine oxide are preferred.

  Examples of the acetophenone photopolymerization initiator include 4- (2-hydroxyethoxy) phenyl (2-hydroxy-2-propyl) ketone (Darocur 2959; manufactured by Ciba Japan), α-hydroxy-α, α′-. Dimethylacetophenone (Darocur 1173; manufactured by Ciba Japan), methoxyacetophenone, 2,2'-dimethoxy-2-phenylacetophenone (Irgacure 651; manufactured by Ciba Japan), 2-hydroxy-2-cyclohexylacetophenone (Irga) Cure 184; manufactured by Ciba Japan Ltd.), 2,2-diethoxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 1-hydroxycyclohexyl phenyl ketone, 4-phenoxydichloroacetophenone, 4-t-butyl-di Such Rollo acetophenone.

  Examples of the benzoin ether photopolymerization initiator include benzoin methyl ether, benzoin ethyl ether, benzoin propyl ether, benzoin isopropyl ether, benzoin isobutyl ether, 2,2-dimethoxy-1,2-diphenylethane-1-one, and anisole. Examples include methyl ether.

  Examples of the α-ketol photopolymerization initiator include 2-methyl-2-hydroxypropiophenone, 1- [4- (2-hydroxyethyl) -phenyl] -2-hydroxy-2-methylpropane-1- ON etc. are mentioned.

  Examples of the aromatic sulfonyl chloride photopolymerization initiator include 2-naphthalenesulfonyl chloride. Examples of the photoactive oxime photopolymerization initiator include 1-phenyl-1,1-propanedione-2- (o-ethoxycarbonyl) -oxime.

  The benzoin photopolymerization initiator includes, for example, benzoin. Examples of the benzyl photopolymerization initiator include benzyl. Examples of the benzophenone photopolymerization initiator include benzophenone, benzoylbenzoic acid, 3,3′-dimethyl-4-methoxybenzophenone, polyvinyl benzophenone, α-hydroxycyclohexyl phenyl ketone, and the like. Examples of the ketal photopolymerization initiator include benzyl dimethyl ketal. Examples of the thioxanthone photopolymerization initiator include thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, 2,4-dimethylthioxanthone, isopropylthioxanthone, 2,4-dichlorothioxanthone, 2,4-diethylthioxanthone, 2,4. -Diisopropylthioxanthone, dodecylthioxanthone and the like are included.

  Moreover, in this invention, the photocationic polymerization initiator which generate | occur | produces an acid by light irradiation as a photoinitiator may be sufficient. Examples of the acid generator include onium salts such as diazonium salts, sulfonium salts, and iodonium salts; organometallic complexes such as iron-allene complexes, titanocene complexes, and arylsilanol-aluminum complexes.

  The amount of the photopolymerization initiator used is preferably 0.01 to 5.0 parts by weight, more preferably 0.1 to 3 parts by weight with respect to 100 parts by weight of the monomer component. The When the addition amount is less than 0.01 parts by weight, the polymerization reaction may be insufficient, and when it exceeds 5.0 parts by weight, the polymer may have a low molecular weight. A photoinitiator can also be used individually or in combination of 2 or more types.

(Fine particles)
In the ultraviolet curable viscoelastic body of the present invention, fine particles can be used.

  By using the fine particles, the shielding property can be improved. Further, for example, the shear adhesive strength in the ultraviolet curable viscoelastic body can be increased, and the workability can be improved. The fine particles may be used alone or in combination of two or more.

  The fine particles used in the ultraviolet curable viscoelastic material of the present invention include metal particles such as copper, nickel, aluminum, chromium, iron, and stainless steel, or metal oxide particles of these metal particles; silicon carbide, boron carbide, carbonized Carbide particles such as nitrogen; nitride particles such as aluminum nitride, silicon nitride and boron nitride; ceramic particles typified by oxides such as alumina and zirconium; inorganic fine particles such as calcium carbide, aluminum hydroxide, glass and silica; volcano Natural raw material particles such as shirasu and sand; polymer particles such as polystyrene, polymethyl methacrylate, phenol resin, benzoguanamine resin, urea resin, silicone resin, nylon, polyester, polyurethane, polyethylene, polypropylene, polyamide, polyimide, etc. It can be. Among these, hollow inorganic fine particles may be used, glass hollow balloons such as hollow glass balloons such as hollow organic fine particles; hollow balloons made of metal compounds such as hollow alumina balloons; hollow ceramics As hollow fine particles such as porcelain hollow balloons and hollow organic fine particles such as balloons, for example, hollow acrylic balloons, resin hollow balloons such as hollow vinylidene chloride balloons, and the like can be preferably used. .

Although it does not restrict | limit especially as specific gravity of microparticles | fine-particles, For example, it can select from the range of 0.1-1.8 g / cm < ³ >. More preferably, it can be selected from the range of 0.2 to 1.5 g / cm ³ , more preferably 0.3 to 1.2 g / cm ³ .

When the specific gravity of the fine particles is smaller than 0.1 g / cm ³ , when the fine particles are mixed and mixed in the ultraviolet curable viscoelastic body, there is a case where the floating becomes large and it is difficult to uniformly disperse the fine particles. . In addition, the glass strength is weak and easily breaks. On the contrary, if it is larger than 1.8 g / cm ³ , there is a risk that the transmittance of ultraviolet rays is lowered and the polymerization rate is lowered. In addition, the ultraviolet curable pressure-sensitive adhesive tape or sheet becomes heavy and workability is deteriorated.

  The amount of the fine particles used is not particularly limited, and is, for example, 0.5 to 20 parts by weight, preferably 1.0 to 18 parts by weight with respect to 100 parts by weight of the monomer component in the ultraviolet curable viscoelastic body. More preferably, it can be selected from a range of 1.5 to 15 parts by weight.

  If the amount of the fine particles used is less than 0.5 parts by weight with respect to 100 parts by weight of the monomer component in the ultraviolet curable viscoelastic body, the effect of adding the fine particles may be reduced. On the other hand, if the amount used exceeds 20 parts by weight, the adhesive strength may be reduced.

(Bubbles)
Moreover, the ultraviolet curable viscoelastic body of the present invention may contain bubbles. The amount of bubbles that can be mixed with the ultraviolet curable viscoelastic material containing bubbles is not particularly limited, and can be appropriately selected depending on the intended use.

  For example, the bubble content is preferably 5 to 40% by volume, more preferably 8 to 35% by volume, and still more preferably 10 to 30% by volume with respect to the total volume of the ultraviolet curable viscoelastic body. When the mixing amount is less than 5% by volume, the effect of mixing the bubbles may not be sufficiently obtained. When the mixing amount is more than 40% by volume, bubbles penetrating the ultraviolet curable viscoelastic material enter, and the adhesion performance and appearance deteriorate. There is a case.

  The bubbles mixed in the ultraviolet-polymerizable composition containing the bubbles can be either closed-cell type or open-cell type, but may be a mixture of them.

  Such bubbles usually have a spherical shape (particularly true spherical shape), but may have an irregular spherical shape, and the particle diameter (average particle diameter) is particularly large. Although it does not restrict | limit, For example, 1-1000 micrometers, Preferably, it is 5-500 micrometers, More preferably, it can select from the range of 10-300 micrometers.

  The gas component contained in the bubbles is not particularly limited, and various gas components such as air can be used in addition to an inert gas such as nitrogen, carbon dioxide, and argon.

  When a reaction such as a polymerization reaction is performed after mixing gas components contained in the bubbles, it is important to use one that does not inhibit the polymerization reaction. Nitrogen is suitable as the gas component contained in the bubbles from the viewpoint of not inhibiting the reaction and cost.

(Surfactant)
In order to stably mix fine bubbles, a surfactant may be added to the ultraviolet polymerizable composition. As the surfactant to be used, a surfactant having a structure of —CH ₂ —CH ₂ —O— or —CH ₂ —CH (CH ₃ ) —O— in the molecule is used. By having this structure in the molecule, the adhesion between the hollow fine particle-like body and the ultraviolet curable viscoelastic body is improved, the stress dispersibility is expressed, and the adhesive strength is expressed.

  The surfactant to be used is not particularly limited as long as it is a surfactant having the structure in the molecule, but from the viewpoint of dispersibility with respect to the monomer component, a nonionic surfactant is preferably used, and a hydrocarbon-based interface is used. An activator, a silicone-based surfactant, a fluorine-based surfactant, or the like can be used.

  Examples of the hydrocarbon surfactant include polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, polyoxyethylene sorbitan alkylate, polyethylene glycol alkylate, and polyoxyethylene alkylamine.

  In particular, a fluorosurfactant containing a fluoropolymer having a weight average molecular weight of 20000 or more is preferable.

  When a fluorine-containing surfactant containing a fluorine-based polymer having a weight average molecular weight of 20000 or more is used, a sufficient amount of bubbles is stabilized in the ultraviolet curable viscoelastic body containing bubbles. Are mixed.

  This is because, since the weight average molecular weight of the fluorine-based polymer constituting the fluorine-based surfactant is as large as 20000 or more, the film strength of the generated bubbles is increased, so that the amount of bubbles that can be mixed increases, This is presumably because the stability of the bubbles is increased and the coalescence of the bubbles is difficult to proceed.

  As the fluorosurfactant, it is preferable to use a fluorosurfactant containing a fluoropolymer having a weight average molecular weight of 20000 or more, 20,000 to 100,000, preferably 22,000 to 80,000, more preferably 24,000 to 60,000. You can select from a range.

  When the weight average molecular weight of the fluoropolymer of the fluorosurfactant is less than 20000, the mixing property of the bubbles and the stability of the mixed bubbles decrease, and the amount of bubbles that can be mixed decreases. In addition, even if mixed, it is easy for the bubbles to coalesce between the mixing of the bubbles and the formation of the ultraviolet curable viscoelastic material containing the bubbles, and as a result, the ultraviolet rays containing the bubbles. The amount of bubbles in the curable viscoelastic body is reduced, and bubbles (holes) penetrating through the ultraviolet curable viscoelastic body containing bubbles are formed.

  In addition, only 1 type may be used for the said fluorine-type polymer, and 2 or more types may be used together.

  Such a fluorine-containing polymer contains at least a monomer having a fluorine atom-containing group (hereinafter sometimes referred to as “fluorine-based monomer”) as a monomer component. As for a fluorine-type monomer, only 1 type may be used and 2 or more types may be used in combination.

  As the fluorine monomer, for example, a vinyl monomer having a fluorine atom-containing group can be suitably used. In such a vinyl monomer having a fluorine atom-containing group, the fluorine atom-containing group is preferably a perfluoro group, and the perfluoro group may be monovalent or a divalent or higher polyvalent. May be a valence.

As the monovalent fluorine atom-containing group (particularly perfluoro group), for example, a perfluoroalkyl group (for example, CF ₃ CF ₂ group, CF ₃ CF ₂ CF ₂ group, etc.) can be preferably used.

  The perfluoroalkyl group may be bonded to the vinyl monomer via another group (for example, —O— group, —OCO— group, alkylene group, etc.). Specifically, the monovalent fluorine atom-containing group includes a perfluoroether group (perfluoroalkyl-oxy group, etc.), a perfluoroester group (perfluoroalkyl-oxycarbonyl group, perfluoroalkyl-carbonyloxy group, etc.). ) Or the like.

Examples of the perfluoroether group include a CF ₃ CF ₂ O group and a CF ₃ CF ₂ CF ₂ O group. Examples of the perfluoroester group include a CF ₃ CF ₂ OCO group, a CF ₃ CF ₂ CF ₂ OCO group, a CF ₃ CF ₂ COO group, and a CF ₃ CF ₂ CF ₂ COO group.

  In the divalent or higher valent fluorine atom-containing group, for example, as the divalent fluorine atom-containing group, a perfluoroalkylene group corresponding to the perfluoroalkyl group (for example, a tetrafluoroethylene group, a hexafluoropropylene group, etc.) Etc.

  The perfluoroalkylene group may be bonded to the main chain via another group (for example, —O— group, —OCO— group, alkylene group, etc.) as in the case of the perfluoroalkyl group. Perfluoroalkylene-oxy groups such as tetrafluoroethylene-oxy group and hexafluoropropylene-oxy group; forms such as perfluoroalkylene-oxycarbonyl groups such as tetrafluoroethylene-oxycarbonyl group and hexafluoropropylene-oxycarbonyl group It may be.

  In such a fluorine-containing group such as a perfluoro group (perfluoroalkyl group, perfluoroalkylene group, etc.), the carbon number of the perfluoro group is not particularly limited, and is, for example, 1 or 2 (preferably 4). To 20, more preferably 4 to 8, and still more preferably 4 to 6).

  As the vinyl monomer having a fluorine atom-containing group, a (meth) acrylic acid ester having a fluorine atom-containing group is particularly suitable. As the (meth) acrylic acid ester having such a fluorine atom-containing group, for example, perfluoroalkyl (meth) acrylate is suitable.

  Examples of perfluoroalkyl (meth) acrylate include perfluoromethyl (meth) acrylate, perfluoroethyl (meth) acrylate, perfluoropropyl (meth) acrylate, perfluoroisopropyl (meth) acrylate, and perfluorobutyl (meth). Acrylate, perfluoroisobutyl (meth) acrylate, perfluoro s-butyl (meth) acrylate, perfluoro t-butyl (meth) acrylate, perfluoropentyl (meth) acrylate, perfluorohexyl (meth) acrylate, perfluoroheptyl ( Examples thereof include perfluoro C1-20 alkyl (meth) acrylate such as (meth) acrylate and perfluorooctyl (meth) acrylate.

  As the fluorine-based polymer, a monomer component capable of copolymerization with the fluorine-based monomer (hereinafter sometimes referred to as “non-fluorine-based monomer”) may be used as a monomer component together with the fluorine-based monomer. A non-fluorine-type monomer can be used individually or in combination of 2 or more types.

  For example, when the fluorine monomer is a vinyl monomer having a fluorine atom-containing group [particularly, a (meth) acrylate ester having a fluorine atom-containing group], the non-fluorine monomer may be a (meth) acrylate ester Can be preferably used, and (meth) acrylic acid alkyl ester is particularly preferable.

  Examples of the (meth) acrylic acid alkyl ester include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, (meth) Isobutyl acrylate, s-butyl (meth) acrylate, t-butyl (meth) acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, octyl (meth) acrylate, 2-Methylhexyl acrylate, isooctyl (meth) acrylate, nonyl (meth) acrylate, isononyl (meth) acrylate, decyl (meth) acrylate, isodecyl (meth) acrylate, undecyl (meth) acrylate , Dodecyl (meth) acrylate, tridecyl (meth) acrylate, (me ) Tetradecyl acrylate, pentadecyl (meth) acrylate, hexadecyl (meth) acrylate, heptadecyl (meth) acrylate, octadecyl (meth) acrylate, nonadecyl (meth) acrylate, eicosyl (meth) acrylate (meta) ) Acrylic acid C1-20 alkyl ester [preferably (meth) acrylic acid C4-18 alkyl ester] and the like.

  In addition, as (meth) acrylic acid esters other than (meth) acrylic acid alkyl ester, for example, it has an alicyclic hydrocarbon group such as cyclopentyl (meth) acrylate, cyclohexyl (meth) acrylate, isobornyl (meth) acrylate ( Examples thereof include (meth) acrylic acid and (meth) acrylic acid having an aromatic hydrocarbon group such as phenyl (meth) acrylate.

  Non-fluorinated monomers include (meth) acrylic acid, itaconic acid, maleic acid, fumaric acid, crotonic acid, isocrotonic acid and other carboxyl group-containing monomers or anhydrides thereof; sulfonic acid such as sodium vinyl sulfonate Group-containing monomers; aromatic vinyl compounds such as styrene and vinyltoluene; cyano group-containing monomers such as acrylonitrile and methacrylonitrile; olefins or dienes such as ethylene, butadiene, isoprene, and isobutylene; vinyl such as vinyl acetate Esters; Vinyl ethers such as vinyl alkyl ethers; Vinyl chloride; Acrylamide, methacrylamide, N-vinylpyrrolidone, N, N-dimethyl (meth) acrylamide, N-methylol (meth) acrylamide, N-methoxymethyl (meth) actyl Amide group-containing monomers such as luamide and N-butoxymethyl (meth) acrylamide; hydroxy (meth) acrylates such as hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate Hydroxyl group-containing monomers such as alkyl; amino group-containing monomers such as aminoethyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, t-butylaminoethyl (meth) acrylate, and (meth) acryloylmorpholine Imide group-containing monomers such as cyclohexylmaleimide and isopropylmaleimide; glycidyl group-containing monomers such as glycidyl (meth) acrylate and methyl glycidyl (meth) acrylate; isocyanate group-containing monomers such as 2-methacryloyloxyethyl isocyanate Mass Etc., and the like.

  Furthermore, as the non-fluorinated monomer, for example, triethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, ethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, neopentyl glycol di ( Multifunctional such as (meth) acrylate, 1,6-hexanediol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, divinylbenzene A copolymerizable monomer (polyfunctional monomer) may be used.

  In the present invention, the fluorine-containing surfactant contains a fluorine-containing polymer having at least a monomer component of a vinyl monomer having a fluorine atom-containing group [particularly, a (meth) acrylic acid ester having a fluorine-containing group]. Fluorosurfactants are preferred, and among them, vinyl monomers having a fluorine atom-containing group [in particular, (meth) acrylic acid ester having a fluorine atom-containing group] and (meth) acrylic acid ester [ In particular, a fluorosurfactant containing a fluoropolymer having at least a (meth) acrylic acid alkyl ester] as a monomer component can be suitably used.

  Specifically, as the fluorosurfactant, trade name “Futgent 251” (manufactured by Neos Co., Ltd.), trade name “FTX-218” (manufactured by Neos Co., Ltd.), trade name “F-top EF-352” (Manufactured by Gemco Co., Ltd.), trade name “F-top EF-801” (manufactured by Gemco Co., Ltd.), trade name “Megafac F-477” (manufactured by Dainippon Ink & Chemicals, Inc.), trade name “Megafuck F- 470 "(Dainippon Ink Chemical Co., Ltd.), trade name" Surflon S-381 "(Seimi Chemical Co., Ltd.), trade name" Surflon S-383 "(Seimi Chemical Co., Ltd.), trade name" Surflon S " -393 "(manufactured by Seimi Chemical Co., Ltd.), trade name" KH-20 "(manufactured by Seimi Chemical Co., Ltd.), trade names" KH-40 "," SC-101 "," SA-100 " (Manufactured by Seimi Chemical Co., Ltd.), "S-381", "S-383", "S-393", and the like can be used trade name "Unidyne TG-65" (manufactured by Daikin Industries, Ltd.).

  The amount of use (solid content) of the fluorosurfactant is not particularly limited. For example, 0.01 to 2.0 parts by weight with respect to 100 parts by weight of the monomer component in the ultraviolet polymerizable composition containing bubbles, Preferably it can select from the range of 0.03-1.5 weight part, More preferably, it is 0.05-1.0 weight part.

  When the amount of the fluorosurfactant used is less than 0.01 parts by weight with respect to 100 parts by weight of the monomer component in the ultraviolet-polymerizable composition containing bubbles, the amount of mixing of the bubbles is lowered and the amount is sufficient. It is difficult to mix the bubbles in the ultraviolet-polymerizable composition containing the bubbles. On the other hand, when the amount exceeds 2.0 parts by weight, the adhesive performance is deteriorated.

  In the present invention, in order to allow bubbles to be stably mixed and present in the ultraviolet polymerizable composition, the bubbles are preferably blended and mixed as the last component to be blended in the ultraviolet polymerizable composition.

  The viscosity of the ultraviolet-polymerizable composition containing bubbles is not particularly limited as long as it is a viscosity capable of stably holding the mixed bubbles. For example, a rotor using a BH viscometer as a viscometer : No. The viscosity measured under the conditions of 5 rotors, rotation speed: 10 rpm, measurement temperature: 30 ° C. is 5 to 50 Pa · s, preferably 10 to 40 Pa · s, and more preferably 15 to 30 Pa · s. desirable.

  When the viscosity (BH viscometer, No. 5 rotor, 10 rpm, 30 ° C.) of the ultraviolet-polymerizable composition containing bubbles is less than 5 Pa · s, the viscosity is too low and the mixed bubbles are immediately combined. On the other hand, if it exceeds 50 Pa · s, the viscosity becomes too high when forming an ultraviolet polymerizable composition containing bubbles, which makes it difficult.

  As described above, the viscosity of the ultraviolet-polymerizable composition containing bubbles is determined by a method of blending various polymer components such as acrylic rubber and a thickening additive, and by partially polymerizing the monomer component to obtain a partially polymerized product. It can be adjusted by a method or the like.

  And the ultraviolet-ray polymerizable composition containing the bubble which contains the bubble stably can be obtained by introduce | transducing and mixing a bubble to this ultraviolet-ray polymerizable composition containing the bubble.

  The method for mixing the bubbles is not particularly limited, and a known bubble mixing method can be used. For example, as an example of the device, a stator having a large number of fine teeth and a stator having teeth are opposed to a disk having a through hole in the center, and the same fine teeth as the stator are on the disk. And a device having a rotor with a mark.

  In this apparatus, an ultraviolet polymerizable composition containing bubbles is introduced between the teeth on the stator and the teeth on the rotor, and gas components (bubbles) are formed to form bubbles through the through-holes while rotating the rotor at a high speed. Forming a gas) into a UV-polymerizable composition containing bubbles, thereby forming a UV-polymerizable composition containing bubbles in which the bubble-forming gas is finely dispersed and mixed in the UV-polymerizable composition containing bubbles. Obtainable.

  In order to suppress or prevent the coalescence of bubbles, it is preferable to continuously perform the steps from the mixing of bubbles to the formation of the ultraviolet polymerizable composition containing the bubbles as a series of steps. That is, after preparing a UV-polymerizable composition containing bubbles by mixing bubbles as described above, a known pressure-sensitive adhesive layer is then used using the UV-polymerizable composition containing the bubbles. It is preferable to form an ultraviolet curable viscoelastic body containing bubbles using the forming method.

  The ultraviolet curable viscoelastic body containing such bubbles is unlikely to cause coalescence of bubbles and stably contains a sufficient amount of bubbles, and thus constitutes an ultraviolet polymerizable composition containing bubbles. By appropriately selecting a polymer, an additive and the like, it can be suitably used as bubbles for forming an ultraviolet polymerizable composition containing bubbles.

  In addition to the above, the ultraviolet-polymerizable composition may contain, as an optional component, a functional group such as an isocyanate group, an epoxy group, an aziridinyl group, an oxazoline group, or a carbodiimide group that can react with a polar functional group of a monomer containing a polar group. Crosslinkable compound, rosin derivative resin, polyterpene resin, petroleum resin, oil-soluble phenol resin, etc., normal, solid, semi-solid or liquid tackifier, plasticizer, softener, filler, aging Various conventionally known additives such as inhibitors, colorants such as pigments and dyes can be appropriately blended within a range that does not impair their photopolymerizability.

(Pigment)
When black is desired as the coloring of the ultraviolet curable viscoelastic body, for example, carbon black can be used in combination. The amount of carbon black used is, for example, 0.001 with respect to 100 parts by weight of the total monomer components for forming the base polymer in the ultraviolet curable viscoelastic body from the viewpoint of not inhibiting the degree of coloring and the photopolymerization reaction. It is preferable to select from a range of ˜0.10 parts by weight, preferably 0.01 to 0.09 parts by weight.

[UV curable adhesive tape or sheet]
The ultraviolet curable pressure-sensitive adhesive tape or sheet of the present invention includes the ultraviolet curable viscoelastic body. Specifically, the ultraviolet curable pressure-sensitive adhesive tape or sheet of the present invention may be composed of an ultraviolet curable viscoelastic body, and has an ultraviolet curable viscoelastic body on at least one side of a substrate, that is, a base. It may have the form of an ultraviolet curable adhesive tape or sheet in which an ultraviolet curable viscoelastic body is laminated on one side of the material, and one side is an adhesive surface, and both surfaces are adhesive surfaces (adhesive surfaces). It may have the form of an ultraviolet curable pressure-sensitive adhesive tape or sheet made of an ultraviolet curable viscoelastic material.

  Below, the manufacturing method of an ultraviolet curable adhesive tape or a sheet | seat is illustrated using FIG.1, FIG.2 and FIG.3. However, the manufacturing method in the present invention is not limited by FIGS. 1, 2, and 3.

  FIG. 1 relates to an ultraviolet curable pressure-sensitive adhesive tape having a structure in which only one surface is an adhesive surface with respect to a substrate 2 in the present invention. Reference numeral 2 denotes a substrate. Reference numeral 1 denotes an ultraviolet polymerizable composition. FIG. 1A shows a state in which the ultraviolet polymerizable composition 1 is directly applied to the substrate 2.

(Base material)
Examples of the substrate 2 include paper-based substrates such as paper; fiber-based substrates such as cloth, non-woven fabric, and net; metal-based substrates such as metal foil and metal plate; plastic-based substrates such as plastic films and sheets. Materials: Rubber base materials such as rubber sheets; Foams such as foam sheets, and laminates thereof (particularly laminates of plastic base materials and other base materials, laminates of plastic films, etc.), etc. Any suitable thin leaf body can be used. As the substrate 2, a plastic substrate such as a plastic film or sheet can be suitably used.

  As a material in such a plastic film or sheet, for example, an α-olefin such as polyethylene (PE), polypropylene (PP), ethylene-propylene copolymer, ethylene-vinyl acetate copolymer (EVA), or the like is used as a monomer component. Olefin resins: Polyester resins such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polybutylene terephthalate (PBT); polyvinyl chloride (PVC); vinyl acetate resin; polyphenylene sulfide (PPS); polyamide (Nylon), amide resins such as wholly aromatic polyamide (aramid); polyimide resins; polyether ether ketone (PEEK). These materials may be used alone or in combination of two.

  In addition, when the plastic base material is used as the base material 2, you may control deformability, such as elongation rate, by extending | stretching process. Moreover, as a base material 2, when an adhesive layer is formed by hardening by an ultraviolet-ray, it is preferable to use what does not inhibit the permeation | transmission of an ultraviolet-ray.

  The thickness of the base material 2 can be appropriately selected according to the strength, flexibility, purpose of use, and the like. For example, it is generally 1 to 1000 μm, preferably 2 to 500 μm, more preferably about 3 to 300 μm. However, it is not limited to these. In addition, the base material 2 may have a single layer form or may have a laminated form.

  The surface of the substrate 2 is chemically treated by conventional surface treatments such as corona treatment, chromic acid treatment, ozone exposure, flame exposure, high-voltage impact exposure, ionizing radiation treatment, etc. in order to improve the adhesion to the adhesive layer. Alternatively, oxidation treatment by a physical method or the like may be performed, or coating treatment by an undercoat agent or a release agent may be performed.

(Application method)
The method in particular of apply | coating the ultraviolet-polymerizable composition 1 to the base material 2 is not restrict | limited, A normal method is employable. Examples thereof include a slot die method, a reverse gravure coating method, a micro gravure method, a dip method, a spin coating method, a brush coating method, a roll coating method, and a flexographic printing method.

  As a coater used at the time of coating, any coating method such as a commonly used roll coater such as a reverse coater or a gravure coater, a curtain coater, a lip coater, a die coater, or a knife coater can be adopted.

(UV curable viscoelastic body)
The thickness of the ultraviolet curable viscoelastic body 3 is not particularly limited, and can be selected from the range of, for example, 10 to 3000 μm, preferably 20 to 2000 μm, and more preferably 30 to 2000 μm. When the thickness of the ultraviolet curable viscoelastic body 3 is smaller than 10 μm, the cushioning property is lowered and the adhesiveness to a curved surface or an uneven surface is lowered. On the other hand, when the thickness is larger than 3000 μm, the ultraviolet polymerization becomes difficult.

  When the ultraviolet polymerizable composition 1 is applied to the substrate 2 or the like, the viscosity can be increased in order to perform the operation smoothly. Thickening can be adjusted by, for example, a method of blending various polymer components such as acrylic rubber and a thickening additive, a method of partially polymerizing monomer components for forming a base polymer, and the like.

  FIG. 1B shows a step of irradiating with ultraviolet rays. The process of irradiating the ultraviolet ray polymerizable composition 1 with the ultraviolet ray 4 in a state where oxygen is blocked through the peeling film 5 is shown.

  FIG. 1C shows an ultraviolet curable pressure-sensitive adhesive sheet obtained by laminating an ultraviolet curable viscoelastic body 3 on one surface of a substrate 2.

(Peeling film)
In the present invention, in order to form and protect the ultraviolet curable viscoelastic body 3, it is preferable to use a release film 5 that transmits ultraviolet rays such as polyethylene terephthalate coated with a release agent such as silicone but blocks oxygen. In order to minimize the influence of oxygen having a polymerization inhibiting effect on the polymer polymerization rate, molecular weight, and molecular weight distribution obtained, it is preferable to carry out lamination in a state where oxygen is blocked by the peeling film 5. In addition, the peeling film 5 can protect the ultraviolet curable viscoelastic body 3 until it peels when using the adhesive surface protected by the peeling film 5.

  As such a release film 5, a conventional release paper or the like can be used. Specifically, the release film 5 includes, for example, a substrate having a release treatment layer with a release treatment agent on at least one surface, and a fluorine-based polymer (eg, polytetrafluoroethylene, polychlorotrifluoroethylene, polyfilm). Low adhesive substrates made of vinyl fluoride, polyvinylidene fluoride, tetrafluoroethylene / hexafluoropropylene copolymer, chlorofluoroethylene / vinylidene fluoride copolymer, etc., and nonpolar polymers (eg, polyethylene, polypropylene, etc.) A low-adhesive base material made of an olefin resin or the like can be used. The peeling film 5 can also be used as the base material 2 for supporting the ultraviolet curable viscoelastic body 3.

  As the release film 5, for example, a release film in which a release treatment layer is formed on at least one surface of a release liner base material can be suitably used. Examples of such release liner substrates include polyester films (polyethylene terephthalate film, etc.), olefin resin films (polyethylene film, polypropylene film, etc.), polyvinyl chloride films, polyimide films, polyamide films (nylon films), rayon films. In addition to plastic base film (synthetic resin film) such as paper, paper (quality paper, Japanese paper, kraft paper, glassine paper, synthetic paper, topcoat paper, etc.), these can be combined by lamination or coextrusion. Examples include layered materials (2 to 3 layer composites).

  On the other hand, the release treatment agent constituting the release treatment layer is not particularly limited, and for example, a silicone release treatment agent, a fluorine release treatment agent, a long-chain alkyl release treatment agent, or the like can be used. The release treatment agents can be used alone or in combination of two or more.

  Peeling using a plastic-based substrate film (especially polyethylene terephthalate film) that can block oxygen when light irradiation is not performed in air or in an inert gas atmosphere as the substrate for the peeling film. A film base material can be suitably used.

  As another method that does not use the peeling film 5, the ultraviolet polymerizable composition 1 is irradiated with light in an inert gas atmosphere such as nitrogen gas instead of the peeling film 5 in the ultraviolet irradiation process of FIG. It may be a process.

  In an inert gas atmosphere, it is desirable that oxygen is not present as much as possible, and the oxygen concentration is preferably 5000 ppm or less. When the amount of dissolved oxygen is large, the amount of radical generation is suppressed, polymerization does not proceed sufficiently, and the resulting polymer polymerization rate, molecular weight and molecular weight distribution may be adversely affected.

(UV irradiation)
In the present invention, as an ultraviolet lamp used for ultraviolet irradiation, a lamp having a spectral distribution in a wavelength region of 300 to 400 nm is used. , Low pressure mercury lamp, high pressure mercury lamp, and ultra high pressure mercury lamp. The illuminance of light can be set to a desired illuminance by adjusting not only the type of lamp but also the distance from the light lamp to the ultraviolet polymerizable composition and the voltage.

In particular, the intensity at a wavelength of 300 to 400 nm is preferably 1 to 50 mW / cm ² , preferably 3 to 30 mW / cm ² . When the illuminance of ultraviolet rays is higher than 50 mW / cm ^2, the molecular weight of the polymer produced due to the influence of the heat of polymerization is lowered and sufficient adhesive properties cannot be obtained, and when it is lower than 1 mW / cm ² , the desired adhesive It takes a lot of UV irradiation time to get The ultraviolet illuminance can be measured with a metal halide lamp “UVR-T1” (manufactured by Topcon Corporation) having a peak sensitivity maximum wave of 350 nm.

  In the method for producing an ultraviolet curable pressure-sensitive adhesive tape or sheet provided with the ultraviolet curable viscoelastic material of the present invention, after coating the specific monomer composition on one surface of the substrate, the monomer composition is polymerized by photopolymerization. An ultraviolet curable viscoelastic body is formed.

(Figure 2)
FIG. 2 shows an example of a method for producing an ultraviolet curable pressure-sensitive adhesive sheet provided with an ultraviolet curable viscoelastic body according to the present invention.

  In FIG. 2A, the ultraviolet polymerizable composition 1 is applied to both surfaces of the substrate 2. FIG. 2B shows an ultraviolet irradiation process, which shows a process of irradiating the ultraviolet polymerizable composition 1 with the ultraviolet rays 4 through the peeling film 5 on both surfaces of the substrate 2. FIG. 2 (c) shows an ultraviolet curable pressure-sensitive adhesive sheet having the ultraviolet curable viscoelastic body 3 on both surfaces of the substrate 2.

(Figure 3)
FIG. 3 shows an example of a method for producing an ultraviolet curable pressure-sensitive adhesive sheet provided with an ultraviolet curable viscoelastic body according to the present invention. In (a), the UV-polymerizable composition 1 is applied on the release film 5. (B) shows the irradiation process of the ultraviolet ray 4, and shows the process of irradiating the ultraviolet polymerizable composition 1 with the ultraviolet ray 4 through the peeling film 5. (C) has shown the obtained ultraviolet curable adhesive sheet.

  Since the ultraviolet curable pressure-sensitive adhesive sheet obtained by the present invention contains a thermochromic pigment, the ultraviolet curable adhesive sheet transmits ultraviolet rays during ultraviolet curing and is sufficiently blackened at room temperature.

  Next, based on an Example, this invention is demonstrated in detail. In addition, this invention is not restrict | limited at all by these examples.

Example 1
(Preparation of UV-polymerizable composition)
To a mixed monomer solution consisting of 90 parts by weight of 2-ethylhexyl acrylate and 10 parts by weight of acrylic acid, 0.10 weight of bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide (Irg819 (manufactured by Ciba Japan)) A syrup containing a prepolymer with a Mw of 5 million is placed in a four-necked flask and exposed to ultraviolet rays in a nitrogen atmosphere and partially photopolymerized (a polymerization rate of 7.0%). I was obtained.

  With respect to 100 parts by weight of this partially polymerized syrup I, 0.08 parts by weight of hexanediol diacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., hereinafter abbreviated as HDDA) and an average particle size of 45 μm glass balloon (manufactured by Tokai Kogyo Co., Ltd.) , Product name “CEL-STAR Z27”, specific gravity 0.27, hereinafter abbreviated as Z27), 9.5 parts by weight, temperature-responsive capsule (discolored at 40 ° C. black → colorless type) (made by Chemtech Co., Ltd., hereinafter abbreviated as black microcapsule) ) 1.0 part by weight was uniformly mixed and defoamed to prepare an ultraviolet polymerizable composition.

(Production of double-sided PSA sheet)
The UV-polymerizable composition is applied to a release surface of a 38 μm-thick polyethylene terephthalate film, one side of which has been subjected to release treatment with silicone, and further, the one side of the 38 μm-thickness is further peel-treated on the surface. A terephthalate film was covered to form a coating layer. This sheet is irradiated with ultraviolet light having a light intensity of 5 mW / cm ² (measured with Topcon UVR-T1 having a peak sensitivity maximum wave of 350 nm) using a black light at a dose of 100 mJ / cm ² , thereby achieving the target ultraviolet curable viscoelasticity. An ultraviolet curable pressure-sensitive adhesive sheet comprising a body was obtained.

(Example 2)
In the preparation of the ultraviolet polymerizable composition of Example 1, an ultraviolet polymerizable composition was prepared in the same manner as in Example 1 except that the amount of black microcapsules added was 3.0 parts by weight. Moreover, the ultraviolet curable adhesive sheet which consists of an ultraviolet curable viscoelastic body was produced like Example 1 using the said ultraviolet polymerizable composition.

(Example 3)
In the preparation of the ultraviolet polymerizable composition of Example 1, the ultraviolet polymerizable composition was prepared in the same manner as in Example 1 except that the amount of black microcapsules added was 6.0 parts by weight. Moreover, the ultraviolet curable adhesive sheet which consists of an ultraviolet curable viscoelastic body was produced like Example 1 using the said ultraviolet polymerizable composition.

(Comparative Example 1)
In the preparation of the ultraviolet polymerizable composition of Example 1, the addition amount of black pigment (manufactured by Nissei Kasei Co., Ltd., trade name “AT-DN101” or below, abbreviated as DN101) instead of 1 part by weight of the black microcapsules is 0. An ultraviolet polymerizable composition was prepared in the same manner as in Example 1 except that the content was 0.03 part by weight. Moreover, it produced similarly to the preparation method of the ultraviolet curable adhesive sheet which consists of an ultraviolet curable viscoelastic body in Example 1 using the said ultraviolet polymerizable composition.

(Comparative Example 2)
In the preparation of the ultraviolet polymerizable composition of Comparative Example 1, the ultraviolet polymerizable composition was prepared in the same manner as in Comparative Example 1 except that the amount of the pigment (DN101) added was 0.05 parts by weight. Moreover, it produced similarly to the preparation method of the ultraviolet curable adhesive sheet which consists of an ultraviolet curable viscoelastic body in the comparative example 1 using the said ultraviolet polymerizable composition.

(Comparative Example 3)
In the preparation of the ultraviolet polymerizable composition of Comparative Example 1, the ultraviolet polymerizable composition was prepared in the same manner as Comparative Example 1 except that the amount of the pigment (DN101) added was 0.15 parts by weight. Moreover, it produced similarly to the preparation method of the ultraviolet curable adhesive sheet which consists of an ultraviolet curable viscoelastic body in the comparative example 1 using the said ultraviolet polymerizable composition.

(Measurement method of darkness of ultraviolet polymerizable composition)
The degree of darkness was measured by measuring the ultraviolet polymerizable composition on a white plate with a simple method spectral color difference meter (trade name “NF333” manufactured by Nippon Denshoku Industries Co., Ltd.).

(Measurement method of transmittance)
The transmittance of the measurement sample was measured with an ultraviolet-visible spectrophotometer (trade name “UV-2550” manufactured by Shimadzu Corporation). The measurement was performed using an integrating sphere attachment device (trade name “ISR-2200”, manufactured by Shimadzu Corporation) in a wavelength range of 300 to 500 nm.

(Examples and comparative examples)
Table 1 below shows the compositions, darkness (L *) and polymerization rate (%) in Examples 1 to 3 and Comparative Examples 1 to 3. The composition is expressed in parts by weight. Moreover, the graph which shows the relationship between the transmittance | permeability of the measurement sample in Examples 1-3 and Comparative Examples 1-3 and a wavelength (measurement range 300-500 nm) is shown to FIGS.

  As can be seen from Examples 1 to 3 and Comparative Examples 1 to 3, by using an ultraviolet curable viscoelastic material characterized by containing a thermochromic pigment that reversibly and transparently discolors due to a temperature rise, It can be seen that the polymerization rate is higher in the examples containing the thermochromic pigments at the same UV irradiation dose, despite the darkness.

  For example, when Example 2 is compared with Comparative Example 2 and Example 3 is compared with Comparative Example 3, the transmittance at 25 ° C. is approximately the same. In Comparative Example 2 and Comparative Example 3, even if ultraviolet irradiation is performed in this state, the ultraviolet-polymerizable composition does not sufficiently transmit ultraviolet rays, and polymerization does not proceed rapidly. However, in Examples 2 and 3, the temperature rises to 100 ° C. or more due to radiation heat accompanying ultraviolet irradiation or polymerization heat due to the polymerization reaction, so that the thermochromic pigment discolors colorless during curing, and light transmittance The polymerization proceeds efficiently by increasing. For this reason, compared with the comparative example using the black pigment which does not discolor by heat, a higher polymerization rate can be obtained, and since it returns to high darkness by being cooled again to 25 ° C., when used in a room temperature atmosphere It can have a well-shielded appearance.

The figure which shows an example of the manufacturing method of the ultraviolet curable adhesive tape or sheet which concerns on this invention The figure which shows an example of the manufacturing method of the ultraviolet curable adhesive tape or sheet which concerns on this invention The figure which shows an example of the manufacturing method of the ultraviolet curable adhesive tape or sheet which concerns on this invention The graph which shows the relationship between the transmittance | permeability of a measurement sample and wavelength (measurement range 300-500 nm) in Example 1 and Comparative Example 1. The graph which shows the relationship between the transmittance | permeability of the measurement sample in Example 2 and Comparative Example 2, and a wavelength (measurement range 300-500 nm). The graph which shows the relationship between the transmittance | permeability of a measurement sample in Example 3 and Comparative Example 3, and a wavelength (measurement range 300-500 nm).

Explanation of symbols

1: UV polymerizable composition 2: Substrate 3: UV curable viscoelastic body 4: UV 5: Release film

Claims (11)

  An ultraviolet curable viscoelastic material comprising a thermochromic pigment that reversibly loses color and develops color when temperature changes.   The ultraviolet curable viscoelastic body according to claim 1, wherein a temperature at which the thermochromic pigment is reversibly decolored and colored is in a range of 30 to 100 ° C.   The transmittance at 25 ° C. is 30% or less in the wavelength region of 400 to 500 nm, the transmittance value increases as the temperature rises, and the transmittance at a temperature exceeding 30 ° C. is in the wavelength region of 400 to 500 nm. The ultraviolet curable viscoelastic body according to claim 1 or 2, which is 10% or more.   The thermochromic pigment 0.01 to 100 parts by weight of the monomer component containing 70 to 99.9 parts by weight of an alkyl (meth) acrylate having an alkyl group having 2 to 20 carbon atoms and 0.1 to 30 parts by weight of a vinyl monomer. The ultraviolet-ray polymerizable composition containing -30 weight part and 0.01-5.0 weight part of photoinitiators is obtained by superposing | polymerizing by irradiating with ultraviolet rays, The any one of Claims 1-3 obtained UV curable viscoelastic material.   The ultraviolet curable viscoelastic body according to claim 4, further comprising 0.001 to 30 parts by weight of a polyfunctional (meth) acrylate with respect to 100 parts by weight of the monomer component.   The ultraviolet curable viscoelastic body according to claim 4 or 5, further comprising 0.5 to 20 parts by weight of fine particles with respect to 100 parts by weight of the monomer component.   The ultraviolet curable adhesive tape or sheet which consists of an ultraviolet curable viscoelastic body of any one of Claims 1-6.   The ultraviolet curable adhesive tape or sheet which has the ultraviolet curable viscoelastic body of any one of Claims 1-6 on the at least single side | surface of a base material.   The thermochromic pigment 0.01 to 100 parts by weight of the monomer component containing 70 to 99.9 parts by weight of an alkyl (meth) acrylate having an alkyl group having 2 to 20 carbon atoms and 0.1 to 30 parts by weight of a vinyl monomer. An ultraviolet curable viscoelastic body that forms an ultraviolet curable viscoelastic body by irradiating ultraviolet rays to an ultraviolet polymerizable composition containing ˜30 parts by weight and a photopolymerization initiator 0.01 to 5.0 parts by weight Production method.   The method for producing an ultraviolet curable viscoelastic body according to claim 9, wherein the ultraviolet polymerizable composition further contains 0.001 to 30 parts by weight of a polyfunctional (meth) acrylate with respect to 100 parts by weight of the monomer component. The method for producing an ultraviolet curable viscoelastic body according to claim 9 or 10, wherein an ultraviolet curable viscoelastic body is formed by irradiating an ultraviolet ray having an intensity of 1 to 50 mW / cm ² at a wavelength of 300 to 400 nm.

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