JP5474452B2 - Solvent-type re-peeling pressure-sensitive adhesive composition - Google Patents

Description

  The present invention relates to a solvent-type re-peeling pressure-sensitive adhesive composition. More specifically, the present invention relates to a solvent-type re-peeling pressure-sensitive adhesive composition and a re-peeling pressure-sensitive adhesive product having a pressure-sensitive adhesive layer formed of the solvent-type re-peeling pressure-sensitive adhesive composition. As an adhesive product for re-peeling, for example, for protecting the surface of an optical member such as an optical polarizing plate (TAC), a retardation plate, an electromagnetic wave (EMI) shield film, an antiglare (antiglare) film, an antireflection film, etc. Examples include adhesive products.

  Optical films such as an optical polarizing plate (TAC), a retardation plate, an electromagnetic wave (EMI) shield film, an antiglare film, and an antireflection film are laminated on a display such as a liquid crystal display and a plasma display. In order to prevent the surface of the optical film from being damaged when manufacturing the display or inspecting the performance of the display, a surface protective film is stuck on the surface, and the protective film is finally Will be removed.

  In recent years, the surface protective film has a property (hereinafter referred to as “familiarity”) that can be quickly applied to an adherend without biting air, adhesiveness to the adherend, and at the time of manufacturing a display. A property capable of being peeled at high speed (hereinafter referred to as “high-speed peelability”) is required. Therefore, in recent years, an acrylic copolymer containing a (meth) acrylic acid alkyl ester having an alkyl group having 16 to 22 carbon atoms is provided in order to maintain wettability to an adherend and give a moist peeling property. The adhesive composition containing is proposed (for example, refer patent document 1). Moreover, as a pressure-sensitive adhesive composition that can be peeled at high speed and has excellent wettability, a (meth) acrylic heavy polymer containing a (meth) acrylic acid alkylene oxide adduct, a (meth) acrylic polymer, or the like as a monomer component is used. A pressure-sensitive adhesive composition containing a coalescence and a crosslinking agent has been proposed (for example, see Patent Document 2).

  However, in order to improve the high-speed peelability and wettability in these pressure-sensitive adhesive compositions, increasing the amount of the (meth) acrylic monomer having an alkylene oxide chain or a long-chain alkyl group increases the adhesive strength during low-speed release. When the degree of cross-linking of the polymer is controlled in order to improve the adhesive force and the high-speed peelability at the time of low-speed peeling, there is a drawback that the conformability is lowered.

  Therefore, in recent years, the development of a solvent-type re-peeling pressure-sensitive adhesive composition excellent in all of high-speed peelability, conformability, and adhesive strength at the time of low-speed peel has been awaited.

JP-A-9-208910 Japanese Patent Laid-Open No. 2005-200540

  The present invention has been made in view of the prior art, and is a solvent-type re-peeling pressure-sensitive adhesive composition excellent in all of high-speed peelability, conformability, and adhesive strength during low-speed peel, and the solvent-type re-peeling It is an object to provide a re-peeling pressure-sensitive adhesive product having a pressure-sensitive adhesive layer formed of a pressure-sensitive adhesive composition.

The present invention is a solvent-type releasable pressure-sensitive adhesive composition containing a pressure-sensitive adhesive polymer and a crosslinking agent, wherein the pressure-sensitive adhesive polymer contains at least one of vinyl acetate and methyl (meth) acrylate in an amount of 50% by mass or more. A macromonomer having a radically polymerizable unsaturated double bond at the end and having a glass transition temperature of 0 to 160 ° C., and an alkyl group having 4 to 12 carbon atoms. A graft copolymer having a graft side chain made of a polymer having a glass transition temperature of 0 to 160 ° C. as a side chain, which is obtained by polymerizing a monomer component containing an alkyl (meth) acrylate having a functional group and a functional group-containing monomer. Further, the present invention relates to a solvent-type re-peeling pressure-sensitive adhesive composition, wherein the cross-linking agent is isocyanurate.

  The solvent-type re-peeling pressure-sensitive adhesive composition of the present invention is excellent in all of high-speed peelability, conformability, and adhesive force during low-speed peel. Therefore, the pressure-sensitive adhesive product for re-peeling of the present invention has a pressure-sensitive adhesive layer formed of the solvent-type re-peeling pressure-sensitive adhesive composition, so that any of high-speed peelability, conformability, and low-pressure peel-off pressure can be obtained. Are better.

  The solvent-type re-peeling pressure-sensitive adhesive composition of the present invention contains a pressure-sensitive polymer and a crosslinking agent. The adhesive polymer is a monomer component containing an alkyl (meth) acrylate (A) having an alkyl group having 4 to 12 carbon atoms (hereinafter referred to as alkyl (meth) acrylate (A)) and a functional group-containing monomer (B). It is obtained by polymerizing.

  In the present specification, “(meth) acrylate” means acrylate and / or methacrylate.

  The number of carbon atoms of the alkyl group of the alkyl (meth) acrylate (A) is 4 to 12, preferably 4 to 10, and more preferably 4 to 9 from the viewpoint of increasing the adhesive strength. In addition, the said alkyl group is a thing of the concept containing a cycloalkyl group.

  Specific examples of the alkyl (meth) acrylate (A) include n-butyl (meth) acrylate, isobutyl (meth) acrylate, sec-butyl (meth) acrylate, tert-butyl (meth) acrylate, and n-amyl (meth). Acrylate, isoamyl (meth) acrylate, n-hexyl (meth) acrylate, cyclohexyl (meth) acrylate, n-heptyl (meth) acrylate, n-octyl (meth) acrylate, isooctyl (meth) acrylate, 2-ethylhexyl (meth) Examples include acrylate, n-nonyl (meth) acrylate, isononyl (meth) acrylate, n-decyl (meth) acrylate, and n-dodecyl (meth) acrylate, but the present invention is not limited to such examples. Absent. These alkyl (meth) acrylates (A) may be used alone or in combination of two or more. Among these alkyl (meth) acrylates (A), since they have excellent polymerizability and the adhesive strength can be arbitrarily adjusted, n-butyl (meth) acrylate, isobutyl (meth) acrylate, sec-butyl (meth) ) Acrylate, tert-butyl (meth) acrylate, n-octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate and isononyl (meth) acrylate are preferred, n-butyl (meth) acrylate and 2-ethylhexyl (meth) acrylate Is more preferable.

  In the functional group-containing monomer (B), the functional group means a group that reacts with the crosslinking agent. Examples of the functional group include a hydroxyl group, a carboxyl group, an amino group, an amide group, and an epoxy group.

  Specific examples of the functional group-containing monomer (B) include 2-hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, caprolactone-modified hydroxy (meth) acrylate, α- (hydroxy Hydroxyl group-containing (meth) acrylates such as methyl) methyl acrylate, α- (hydroxymethyl) ethyl acrylate, and polyester diol mono (meth) acrylate; unsaturated monocarboxylic acids such as (meth) acrylic acid, cinnamic acid, and crotonic acid; Unsaturated dicarboxylic acids such as maleic acid, fumaric acid, itaconic acid and citraconic acid; carboxyl group-containing monomers such as monoesters of the unsaturated dicarboxylic acids; (meth) acrylates having amino groups, amide groups or epoxy groups However, the present invention is not limited to such examples. These functional group-containing monomers (B) may be used alone or in combination of two or more. Among these functional group-containing monomers (B), a hydroxyl group-containing (meth) acrylate is preferable from the viewpoint of improving reactivity and compatibility with a crosslinking agent, and 2-hydroxyethyl (meth) acrylate and 4-hydroxybutyl. (Meth) acrylate is more preferred, and 4-hydroxybutyl (meth) acrylate is more preferred.

  The ratio of the alkyl (meth) acrylate (A) to the functional group-containing monomer (B) [alkyl (meth) acrylate (A) / functional group-containing monomer (B): mass ratio] is high-speed peelability, conformability and low speed. From the viewpoint of maintaining the balance of the adhesive strength during peeling, it is preferably 50/50 to 99/1, more preferably 50/50 to 98/2, still more preferably 65/35 to 98/2, and still more preferably 80. / 20 to 98/2, particularly preferably 90/10 to 98/2.

  The monomer component preferably contains at least one long-chain-containing monomer selected from the group consisting of an alkylene oxide group-containing monomer and a long-chain alkyl group-containing monomer from the viewpoint of improving compatibility. . Among these long-chain-containing monomers, an alkylene oxide group-containing monomer is used from the viewpoint of further reducing the viscosity of the pressure-sensitive adhesive composition of the present invention and further improving the conformability without reducing the molecular weight of the pressure-sensitive adhesive polymer. Is preferred.

  Examples of the alkylene oxide group-containing monomer include, for example, an alkylene oxide group-containing (meth) acrylate, formula (I):

(In the formula, R ¹ is an alkenyl group having 2 to 5 carbon atoms, R ² is a hydrogen atom or a monovalent hydrocarbon group having 1 to 8 carbon atoms, and any of R ³ and R ⁴ is a hydrogen atom. Are methyl groups, or both are hydrogen atoms, p is a number from 1 to 50)
The alkylene oxide group containing monomer etc. which are represented by these, etc. are mentioned, These may each be used independently and may use 2 or more types.

  Examples of the alkylene oxide group contained in the alkylene oxide group-containing (meth) acrylate include an ethylene oxide group and a propylene oxide group, and these may be used alone or in combination. The terminal of the alkylene oxide group contained in the alkylene oxide group-containing (meth) acrylate may be a hydroxyl group or a group such as an alkyl group having 1 to 4 carbon atoms such as a methyl group.

  Examples of the alkylene oxide group-containing (meth) acrylate include methoxydiethylene glycol (meth) acrylate, methoxytriethylene glycol (meth) acrylate, methoxydipropylene glycol (meth) acrylate, methoxytripropylene glycol (meth) acrylate, ethoxydiethylene glycol ( Alkoxy polyalkylene glycol (meth) acrylates having 1 to 4 carbon atoms in the alkoxy group such as (meth) acrylate, ethoxytriethylene glycol (meth) acrylate, butoxydiethylene glycol (meth) acrylate, butoxytriethylene glycol (meth) acrylate; Phenoxydiethylene glycol (meth) acrylate, phenoxytriethylene glycol (meth) acrylate Examples include aryloxy polyalkylene glycol (meth) acrylates having 6 to 12 carbon atoms in aryl groups such as a rate; 2-ethylhexyl diglycol (meth) acrylate, polyethylene glycol (meth) acrylate, and polypropylene glycol (meth) acrylate. However, the present invention is not limited to such examples. These alkylene oxide group-containing (meth) acrylates may be used alone or in combination of two or more.

  As a suitable alkylene oxide group-containing (meth) acrylate, from the viewpoint of improving compatibility, (meth) acrylate having an ethylene oxide group, (meth) acrylate having a propylene oxide group, and an ethylene oxide group and a propylene oxide group (Meth) acrylates having the formula (II):

(In the formula, R ³ and R ⁴ are the same as described above, q represents a number of 1 to 30)
An alkylene oxide group-containing (meth) acrylate represented by As described above, R ³ and R ⁴ are either a hydrogen atom and either a methyl group or both are hydrogen atoms. q is a number from 1 to 30.

  In the alkylene oxide group-containing (meth) acrylate represented by the formula (II), q indicating the number of added moles of ethylene oxide and / or propylene oxide is preferably 1 to 30 mol from the viewpoint of improving the conformability. Preferably it is 2-20 mol, More preferably, it is 2-10 mol.

In the alkylene oxide group-containing monomer represented by the formula (I), R ¹ is an alkenyl group having 2 to 5 carbon atoms. Examples of the alkenyl group having 2 to 5 carbon atoms include a vinyl (CH ₂ ═CH—) group, an isopropenyl [CH ₂ ═C (CH) ₃ —] group, and an allyl (CH ₂ ═CH—CH ₂ —) group. Methallyl [CH ₂ ═C (CH ₃ ) —CH ₂ —] group, 3-butenyl group, 2-methyl-1-butenyl group, 3-methyl-1-butenyl group, 2-methyl-3-butenyl group, 3-methyl-3-butenyl group etc. are mentioned. Among these alkenyl groups, an allyl group and a methallyl group are preferred because of excellent polymerizability with the alkyl (meth) acrylate (A).

In the alkylene oxide group-containing monomer represented by the formula (I), R ² represents a hydrogen atom or a monovalent hydrocarbon group having 1 to 8 carbon atoms. Examples of the monovalent hydrocarbon group having 1 to 8 carbon atoms include alkyl groups having 1 to 8 carbon atoms such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a neopentyl group, a hexyl group, a heptyl group, and an octyl group. An aryl group having 6 to 8 carbon atoms such as a phenyl group, an aralkyl group having 7 to 8 carbon atoms such as a benzyl group, and an alkylaryl group having 7 to 8 carbon atoms such as a cresyl group. Among R ² , from the viewpoint of handleability, a hydrogen atom and an alkyl group having 1 to 4 carbon atoms are preferable, and a hydrogen atom and a methyl group are more preferable.

In the alkylene oxide group-containing monomer represented by the formula (I), either R ³ and R ⁴ are hydrogen atoms and either are methyl groups or both are hydrogen atoms. p represents the number of moles of ethylene oxide and / or propylene oxide added. p represents a number of 1 to 50, preferably a number of 2 to 20, from the viewpoint of improving the conformability.

  In the alkylene oxide group-containing monomer represented by the formula (I), as a preferable monomer from the viewpoint of improving the conformability, the formula (Ia):

(Wherein R ³ , R ⁴ and p are the same as above)
The alkylene oxide group containing monomer represented by these is mentioned.

  A typical example of the long chain alkyl group-containing monomer is a long chain alkyl group-containing (meth) acrylate having 16 to 22 carbon atoms. Specific examples of the long chain alkyl group-containing (meth) acrylate having 16 to 22 carbon atoms include palmityl (meth) acrylate, stearyl (meth) acrylate, isostearyl (meth) acrylate, and behenyl (meth) acrylate. The present invention is not limited to such examples. These long chain alkyl group-containing (meth) acrylates may be used alone or in combination of two or more.

  Among the long chain alkyl group-containing (meth) acrylates having 16 to 22 carbon atoms, since they are excellent in polymerizability and compatibility with the alkyl (meth) acrylate (A), the formula (III):

(Wherein r represents the number of 15-21)
A long chain alkyl group-containing (meth) acrylate represented by

  From the above, from the viewpoint of improving the conformability, as the long-chain-containing monomer, the alkylene oxide group-containing (meth) acrylate, the alkylene oxide group-containing monomer represented by the formula (I), and a long chain having 16 to 22 carbon atoms are used. At least one monomer selected from the group consisting of chain alkyl group-containing (meth) acrylates is preferred. Further, from the viewpoint of reducing the viscosity of the pressure-sensitive adhesive composition of the present invention and improving the conformability without reducing the molecular weight of the pressure-sensitive polymer, the alkylene oxide group-containing (meth) acrylate and the formula (I) are used. The alkylene oxide group-containing monomer is preferably used, and these monomers may be used alone or in combination.

  The amount of the long chain-containing monomer per 100 parts by mass of the total amount of the alkyl (meth) acrylate (A) and the functional group-containing monomer (B) is preferably 3 parts by mass or more, more preferably from the viewpoint of improving the conformability. Is 5 parts by mass or more, more preferably 10 parts by mass or more, and preferably 40 parts by mass or less, more preferably 35 parts by mass or less, and further preferably 30 parts by mass or less, from the viewpoint of increasing the cohesive force of the adhesive polymer. is there.

  The adhesive polymer used in the present invention preferably has a graft side chain made of a polymer having a glass transition temperature of 0 ° C. or more from the viewpoint of improving the high-speed peelability and the adhesive force at the time of low-speed peel in a balanced manner.

  The glass transition temperature of the polymer constituting the graft side chain is preferably 0 ° C. or higher, more preferably 0 to 160 ° C., more preferably from the viewpoint of improving the high-speed peelability and the adhesive force at the time of low-speed peel in a balanced manner. Preferably it is 5-80 degreeC, More preferably, it is 5-40 degreeC.

  The mass average molecular weight of the polymer constituting the graft side chain is preferably 15000 to 100,000, more preferably 20,000 to 70,000, from the viewpoint of improving high-speed peelability.

  The content of the polymer constituting the graft side chain in the adhesive polymer is 3% by mass or more, more preferably 5% by mass or more from the viewpoint of enhancing the high-speed peelability, and increases the adhesive force during low-speed peeling. From the viewpoint of improving the conformability, it is preferably 30% by mass or less, more preferably 25% by mass or less.

  As a raw material for the polymer constituting the graft side chain, for example, a macromonomer can be used. The macromonomer has a radically polymerizable unsaturated double bond at the terminal.

  The macromonomer is prepared by, for example, polymerizing a macromonomer raw material monomer in the presence of a chain transfer agent to prepare a polymer for macromonomer, and the resulting polymer for macromonomer and a radical polymerizable unsaturated double bond. It can be prepared by reacting with a radically polymerizable monomer.

  First, for example, a macromonomer polymer is prepared by polymerizing a macromonomer raw material monomer in the presence of a chain transfer agent.

  In order to prevent gelation, the raw material monomer for macromonomer is preferably a monomer having one unsaturated double bond from the viewpoint of preventing the resulting macromonomer from having crosslinkability.

  Suitable raw material monomers for macromonomer include, for example, vinyl acetate [glass transition temperature of the homopolymer (hereinafter referred to as Tg): 30.0 ° C., the same applies hereinafter], methyl acrylate (Tg: 10.0 ° C.), acrylic Acid (Tg: 106.0 ° C), methyl methacrylate (Tg: 104.9 ° C), cyclohexyl methacrylate (Tg: 65.9 ° C), benzyl acrylate (Tg: 6.0 ° C), isobornyl acrylate (Tg: 94.0 ° C.), isobornyl methacrylate (Tg: 145.0 ° C.), acrylonitrile (Tg: 95.0 ° C.), styrene (Tg: 100.0 ° C.), and the like. It is not limited to only. These macromonomer raw material monomers may be used alone or in combination of two or more. The macromonomer raw material monomer may contain other monomers as long as the glass transition temperature of the polymer constituting the graft side chain is within the above temperature range. From the viewpoint of improving the transparency of the coating film, the macromonomer raw material monomer preferably contains at least one of vinyl acetate and methyl (meth) acrylate in an amount of 50% by mass or more.

  In addition, the glass transition temperature of the said homopolymer is described in the polymer handbook etc., for example. Further, the glass transition temperature of the copolymer is calculated from the glass transition temperature (absolute temperature) of the homopolymer of each monomer constituting the copolymer and its mass fraction:

Wherein, W _n is the mass fraction of each monomer, Tg _n represents a glass transition temperature (K) of homopolymer consisting each monomer]
Can be determined based on

  Examples of the chain transfer agent include compounds having a carboxyl group and / or a hydroxyl group and at least one thiol group.

  Specific examples of the chain transfer agent include thioglycolic acid, 2-mercaptopropionic acid, 3-mercaptopropionic acid, thiomalic acid, mercaptostearic acid, mercaptoacetic acid, mercaptobutyric acid, mercaptooctanoic acid, mercaptobenzoic acid, mercaptonicotinic acid, Examples thereof include carboxyl group-containing mercapto compounds such as cysteine, N-acetylcysteine and mercaptothiazole acetic acid; and hydroxyl group-containing mercapto compounds such as mercaptoethanol, but the present invention is not limited to such examples.

  Although the quantity of a chain transfer agent is not specifically limited, Usually, it is preferable that it is about 0.05-1 mass part per 100 mass parts of raw material monomers for macromonomers.

  As a method for polymerizing the raw material monomer for the macromonomer, a solution polymerization method is preferable because it is easy to remove the polymerization heat. An organic solvent is used when the macromonomer raw material monomer is polymerized by the solution polymerization method. Examples of the organic solvent include aromatic hydrocarbon compounds such as toluene and xylene; fatty acid esters such as ethyl acetate and butyl acetate; alicyclic hydrocarbon compounds such as cyclohexane; and aliphatic hydrocarbon compounds such as hexane and pentane. Although mentioned, this invention is not limited only to this illustration. These organic solvents may be used alone or in combination of two or more. The amount of the organic solvent is not particularly limited, and an amount suitable for solution polymerization is selected.

  Since the reaction conditions such as the polymerization temperature and polymerization time of the raw material monomer for macromonomer vary depending on the type of raw material monomer for macromonomer and the chain transfer agent, etc., it cannot be determined unconditionally. It is preferable to determine appropriately. Moreover, it is preferable that the atmosphere at the time of superposing | polymerizing the raw material monomer for macromonomers is inert gas atmosphere, such as nitrogen gas, for example. Further, the pressure of the atmosphere may be normal pressure (atmospheric pressure), reduced pressure, or increased pressure.

  When polymerizing the raw monomer for the macromonomer, a polymerization initiator can be used. Examples of the polymerization initiator include methyl ethyl ketone peroxide, benzoyl peroxide, dicumyl peroxide, tert-butyl hydroperoxide, cumene hydroperoxide, lauroyl peroxide, tert-butyl peroxyoctate, and tert-butyl peroxy. Organic peroxides such as benzoate, a mixture of m-toluoyl peroxide and benzoyl peroxide [manufactured by NOF Corporation, trade name: Nyper BMTERT-K40]; 2,2′-azobisisobutyronitrile, 2 , 2′-azobis (2-methylbutyronitrile), 2,2′-azobis (2,4-dimethylvaleronitrile) and the like, but the present invention is limited only to such examples. It is not something.

  Although the quantity of a polymerization initiator is not specifically limited, Usually, it is preferable that it is about 0.01-5 mass parts per 100 mass parts of raw material monomers for macromonomers.

  As described above, the macromonomer polymer is obtained by polymerizing the macromonomer raw material monomer in the presence of the chain transfer agent. The resulting polymer for macromonomer has a functional group introduced by a chain transfer agent introduced at its terminal.

  When a monomer having one unsaturated double bond is used as a raw material monomer for macromonomer, a functional group based on a chain transfer agent is introduced into one end of the obtained polymer for macromonomer. The macromonomer polymer in which a functional group by a chain transfer agent is introduced at one end in this way is a monofunctional polymer, and therefore, unlike a polyfunctional macromonomer polymer, it prevents gelation during polymerization. There is an advantage that you can. Therefore, the macromonomer polymer is preferably a monofunctional macromonomer polymer.

  Next, the macromonomer polymer thus obtained is reacted with a radical polymerizable monomer having a radical polymerizable unsaturated double bond (hereinafter referred to as a radical polymerizable unsaturated double bond-containing monomer). Thus, a macromonomer can be prepared.

  This radical polymerizable unsaturated double bond-containing monomer can be added to the reaction mixture obtained by preparing the polymer for macromonomer. At that time, the radical polymerizable unsaturated double bond-containing monomer may be diluted with an organic solvent, if necessary.

  The amount of the radical polymerizable unsaturated double bond-containing monomer is usually preferably about 0.8 to 1 mole per mole of the functional group of the macromonomer polymer.

  Examples of the radical polymerizable unsaturated double bond-containing monomer include aliphatic epoxy monomers such as glycidyl (meth) acrylate, allyl glycidyl ether, 4-hydroxybutyl acrylate glycidyl ether, and 3,4-epoxycyclohexylmethyl (meth). Epoxy monomers such as alicyclic epoxy monomers such as acrylate; 2- (vinyloxyethoxy) ethyl (meth) acrylate; 2-isopropenyl-2-oxazoline; N- (meth) acryloylaziridine; 3- (meth) (Meth) acryloyl isocyanate; (meth) acryloyl ethyl isocyanate, (meth) acryloyl propyl isocyanate and other (meth) acryloyl alkyl isocyanates; 2- (meth) acrylic; (Meth) acryloyloxyalkyl isocyanates such as royloxyethyl isocyanate and 3- (meth) acryloyloxypropyl isocyanate; isocyanate monomers such as 3-isopropenyl-α, α′-dimethylbenzyl isocyanate; 2- (vinyloxyethoxy) Although ethyl (meth) acrylate etc. are mentioned, this invention is not limited only to this illustration.

  In addition, when a carboxyl group is introduced as a functional group by a chain transfer agent to the macromonomer polymer, from the viewpoint of increasing the reactivity with the functional group of the macromonomer polymer, a radical polymerizable unsaturated double bond Examples of the containing monomer include aliphatic epoxy monomers such as glycidyl (meth) acrylate, allyl glycidyl ether, 4-hydroxybutyl acrylate glycidyl ether, and alicyclic epoxy monomers such as 3,4-epoxycyclohexylmethyl (meth) acrylate. 2- (vinyloxyethoxy) ethyl (meth) acrylate; 2-isopropenyl-2-oxazoline; N- (meth) acryloylaziridine; 3- (meth) acryloxymethyloxetane, etc. preferable

  In addition, when a hydroxyl group is introduced as a functional group by a chain transfer agent to the macromonomer polymer, it contains a radical polymerizable unsaturated double bond from the viewpoint of increasing the reactivity with the functional group of the macromonomer polymer. Examples of the monomer include (meth) acryloyl isocyanate; (meth) acryloyl alkyl isocyanate such as (meth) acryloyl ethyl isocyanate and (meth) acryloyl propyl isocyanate; 2- (meth) acryloyloxyethyl isocyanate, 3- (meth) acryloyloxy (Meth) acryloyloxyalkyl isocyanates such as propyl isocyanate; isocyanate monomers such as 3-isopropenyl-α, α'-dimethylbenzyl isocyanate; 2- (vinyloxyethoxy) ethyl ( It is preferable to use (meth) acrylate or the like.

  When using a polymer for a macromonomer having a carboxyl group introduced as a functional group by a chain transfer agent and using an epoxy monomer as a radical polymerizable unsaturated double bond-containing monomer, the reaction temperature is usually 70 to 120 ° C. The reaction time is preferably about 2 to 10 hours. The end point of the reaction can be determined, for example, by measuring the acid value. An esterification catalyst can be used when the macromonomer polymer introduced with a carboxyl group is reacted with an epoxy monomer. Examples of the esterification catalyst include amines such as triethylamine; quaternary ammonium salts such as tetraethylammonium chloride; and phosphorus compounds such as triphenylphosphine. However, the present invention is not limited only to such examples. .

Moreover, when using the polymer for macromonomers into which the hydroxyl group was introduce | transduced as a functional group with the chain transfer agent, and using an isocyanate type monomer as a radically polymerizable unsaturated double bond containing monomer, reaction temperature is 50-50 normally. It is preferable that the reaction time is about 30 minutes to 10 hours. The end point of the reaction can be confirmed, for example, by disappearance of a peak around 2270 cm ⁻¹ derived from the NCO group by infrared absorption analysis. In addition, when reacting the polymer for macromonomer introduced with a hydroxyl group and the isocyanate monomer, a metal catalyst, an amine catalyst, or the like can be used. Examples of the metal catalyst include dibutyltin dilaurate, tin octoate, dibutyltin di (2-ethylhexanoate), 2-ethylhexanoate lead, 2-ethylhexyl titanate, 2-ethylhexanoate iron, Examples include 2-ethylhexanoate cobalt, zinc naphthenate, cobalt naphthenate, and tetra-n-butyltin, but the present invention is not limited to such examples. Examples of the amine-based catalyst include tertiary amines such as tetramethylbutanediamine, but the present invention is not limited to such examples.

  In addition, when making the polymer for macromonomers react with a radically polymerizable unsaturated double bond containing monomer, a polymerization inhibitor can be used in an appropriate amount. Examples of the polymerization inhibitor include hydroquinone, methylhydroquinone, tert-butylhydroquinone, p-methoxyphenol, and the like, but the present invention is not limited to such examples.

  As described above, a macromonomer having a radical polymerizable unsaturated double bond at the terminal is obtained. When a monofunctional macromonomer is used as the macromonomer, unlike the polyfunctional macromonomer, there is an advantage that gelation during polymerization can be prevented. Therefore, in the present invention, the macromonomer is preferably a monofunctional macromonomer. The monofunctional macromonomer can be prepared by using a monofunctional macromonomer polymer in which a functional group by a chain transfer agent is introduced at one end as a macromonomer polymer. The obtained macromonomer reaction mixture may be used as it is for the monomer component.

  The mass average molecular weight of the macromonomer is preferably 15000 to 100,000, more preferably 20,000 to 70,000, from the viewpoint of improving the high-speed peelability. The mass average molecular weight of the macromonomer can be easily adjusted by adjusting the amount of the chain transfer agent used as a raw material for the macromonomer.

  The glass transition temperature of the macromonomer is preferably 0 ° C. or higher, more preferably 0 to 160 ° C., and even more preferably 5 to 80 from the viewpoint of improving the high-speed peelability and the adhesive force at the time of low-speed peel in a balanced manner. ° C, more preferably 5 to 40 ° C.

  The amount of the macromonomer relative to the total amount of the alkyl (meth) acrylate (A) and the functional group-containing monomer (B) is such that the content of the polymer constituting the graft side chain in the adhesive polymer is as described above. From the viewpoint of improving the high-speed peelability, it is adjusted to 3% by mass or more, more preferably 5% by mass or more, and from the viewpoint of increasing the adhesive force at the time of low-speed peeling and improving the conformability, preferably 30% by mass or less. More preferably, it is desirable to adjust the content to 25% by mass or less.

  In the above, the method for preparing an adhesive polymer having a graft side chain using a macromonomer, that is, the macromonomer method has been described. However, in addition to the macromonomer method, an adhesive polymer having a graft side chain is, for example, an ion It can be prepared by a polymerization method, a method of introducing a polymer for a macromonomer by polymerization, or the like. The macromonomer method makes it easy to control the molecular weight of the backbone polymer and the polymer constituting the graft side chain, suppresses the formation of a homopolymer, and constitutes the backbone polymer and the graft side chain. This has the advantage that the polymer can be easily bonded.

  In the present invention, other monomers (hereinafter referred to as other monomers) other than the above-described monomers may be included in the monomer component within a range in which the object of the present invention is not inhibited.

  Examples of other monomers include alkyl (meth) acrylates having 1 to 3 carbon atoms in alkyl groups such as methyl (meth) acrylate and ethyl (meth) acrylate; aromatic ring containing (meth) such as benzyl (meth) acrylate Acrylate; Aliphatic unsaturated hydrocarbon compound such as ethylene and butadiene; Halogenated aliphatic unsaturated hydrocarbon compound such as vinyl chloride; Aromatic unsaturated hydrocarbon compound such as styrene and α-methylstyrene; Vinyl ether; Allyl alcohol Examples include esters with organic acids; ethers of allyl alcohol with other alcohols; unsaturated cyanide compounds such as acrylonitrile; vinyl acetate. The present invention is not limited to such examples. These other monomers may be used alone or in combination of two or more.

  The content of other monomers in the monomer component is preferably adjusted as appropriate as long as the object of the present invention is not impaired, but is usually 10% by mass or less.

  The polymerization method of the monomer component is preferably a solution polymerization method because heat removal and molecular weight adjustment are easy.

  Examples of the solvent used in the solution polymerization method include aromatic hydrocarbon compounds such as toluene and xylene; fatty acid esters such as ethyl acetate and butyl acetate; alicyclic hydrocarbon compounds such as cyclohexane; and aliphatics such as hexane and pentane. Although a hydrocarbon compound etc. are mentioned, this invention is not limited only to this illustration. These organic solvents may be used alone or in combination of two or more.

  Since the reaction conditions such as the polymerization temperature and polymerization time of the monomer component vary depending on the composition of the monomer component and the like and cannot be determined unconditionally, it is preferable to determine appropriately according to the composition. Moreover, it is preferable that the atmosphere at the time of polymerizing a monomer component is inert gas atmosphere, such as nitrogen gas, for example. Further, the pressure of the atmosphere may be normal pressure (atmospheric pressure), reduced pressure, or increased pressure.

  When the monomer component is polymerized, a polymerization initiator can be used. Examples of the polymerization initiator include methyl ethyl ketone peroxide, benzoyl peroxide, dicumyl peroxide, tert-butyl hydroperoxide, cumene hydroperoxide, lauroyl peroxide, tert-butyl peroxyoctate, and tert-butyl peroxy. Organic peroxides such as benzoate, a mixture of m-toluoyl peroxide and benzoyl peroxide [manufactured by NOF Corporation, trade name: Nyper BMTERT-K40]; 2,2′-azobisisobutyronitrile, 2 , 2′-azobis (2-methylbutyronitrile), 2,2′-azobis (2,4-dimethylvaleronitrile) and the like, but the present invention is limited only to such examples. It is not something.

  Although the quantity of a polymerization initiator is not specifically limited, Usually, it is preferable that it is about 0.01-5 mass parts per 100 mass parts of monomer components.

  For the monomer component, a chain transfer agent such as dodecyl mercaptan may be used as necessary.

  As described above, an adhesive polymer is obtained by polymerizing the monomer component. The mass average molecular weight of the obtained adhesive polymer is preferably 50,000 from the viewpoint of suppressing the adhesive force from becoming too strong when the adherend using the adhesive polymer is heat-treated by an autoclave or the like. Above, more preferably 100,000 or more, and preferably 800,000 or less, more preferably 600,000 or less from the viewpoint of improving the conformability.

  The glass transition temperature of the adhesive polymer is 0 ° C. even when it has a graft side chain because the monomer component containing the alkyl (meth) acrylate (A) and the functional group-containing monomer (B) is used. Lower than. The glass transition temperature of the adhesive polymer can be easily adjusted by adjusting the composition of the monomer component. The glass transition temperature of the adhesive polymer is preferably −20 ° C. or less, more preferably −35 ° C. or less, from the viewpoint that the adherend is less likely to be contaminated by increasing the cohesive force of the adhesive composition of the present invention. From the viewpoint of improving the cohesive force and preventing contamination of the adherend, it is preferably −80 ° C. or higher, more preferably −70 ° C. or higher.

  In the present invention, the adhesive polymer may contain another polymer other than the adhesive polymer as long as the object of the present invention is not hindered.

  The viscosity at 25 ° C. (viscosity when measured at 25 ° C. using a B-type viscometer, rotor No. 3) of the adhesive polymer solution having a nonvolatile content of 50% by mass is the pressure-sensitive adhesive of the present invention. From the viewpoint of facilitating mixing of the crosslinking agent and additives contained in the composition, reducing coating unevenness, increasing the drying speed and coating speed, and extending the pot life of the pressure-sensitive adhesive composition of the present invention. It is preferably 2500 mPa · s or less. In the present invention, the monomer component includes a long-chain-containing monomer and / or a macromonomer from the viewpoint that the viscosity at 25 ° C. of the adhesive polymer solution having a nonvolatile content concentration of 50% by mass is 2500 mPa · s or less. It is preferable to contain.

  The pressure-sensitive adhesive composition of the present invention contains a pressure-sensitive polymer and a crosslinking agent. In addition, since an adhesive polymer has a function as an adhesive, it can be used as an adhesive. As said crosslinking agent, the compound which has 2 or more of functional groups which have reactivity with respect to the functional group which an adhesive polymer has in 1 molecule can be used.

  Examples of the compound having two or more functional groups reactive to the functional group of the adhesive polymer in one molecule include polyisocyanates and polyfunctional epoxy compounds.

  Examples of the polyisocyanate include aliphatic polyisocyanates such as xylylene diisocyanate, diphenylmethane diisocyanate, triphenylmethane triisocyanate, and tolylene diisocyanate, aliphatics such as hexamethylene diisocyanate, isophorone diisocyanate, and hydrogenated products of the above aromatic polyisocyanates. Alternatively, alicyclic polyisocyanates, dimers or trimers of these polyisocyanates, adducts composed of these polyisocyanates and polyols such as trimethylolpropane, and the like may be used alone or in combination The above can be used together.

  Polyisocyanates are, for example, “Coronate L”, “Coronate L-55E”, “Coronate HX”, “Coronate HL”, “Coronate HL-S”, “Coronate 2234”, “Aquanate 200”, “Aquanate 210”. [The above is made by Nippon Polyurethane Industry Co., Ltd., “Coronate” and “Aquanate” are registered trademarks], “Desmodule N3400” (manufactured by Sumitomo Bayer Urethane Co., Ltd. (currently Bayer AG), “Death” "Module" is a registered trademark), "Duranate D-201", "Duranate TSE-100", "Duranate TSS-100", "Duranate 24A-100", "Duranate E-405-80T" [above, Asahi Kasei Corporation "Duranate" is a registered trademark], "Takenate D-110N", "Takenate D 120N "," Takenate M-631N "," MTERT-Olestar NP1200 "(Mitsui Takeda Chemical Co., Ltd. (currently Mitsui Chemicals Polyurethanes Co., Ltd.)," Takenate "and" Olestar "are registered trademarks), etc. As commercially available. These polyisocyanates may be used alone or in combination of two or more.

  Examples of the polyfunctional epoxy compound include ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, bisphenol A type epoxy resin, N, N, N ′, N′-tetraglycidyl- m-xylenediamine, 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane, N, N-diglycidylaniline, N, N-diglycidyltoluidine and the like may be mentioned, each of which may be used alone or as 2 More than one species can be used in combination.

  Among the compounds having two or more functional groups in one molecule that are reactive with the functional group of the adhesive polymer, the amount of polyisocyanate is 2 from the viewpoint of improving the high-speed peelability while maintaining the compatibility. At least one polyisocyanate selected from the group consisting of a polyisocyanate, a polyisocyanate trimer, a polyisocyanate bifunctional prepolymer and a polyisocyanate adduct, and more preferably a polyisocyanate trimer. Furthermore, among compounds having two or more functional groups in one molecule that are reactive to the functional group of the adhesive polymer, the balance of high-speed peelability, conformability, and adhesive force during low-speed release is maintained. From the viewpoint, a dimer of hexamethylene diisocyanate, an isocyanurate of hexamethylene diisocyanate (trimer) and an adduct of tolylene diisocyanate and trimethylolpropane are preferable, and an isocyanurate of hexamethylene diisocyanate is more preferable. Examples of the isocyanurate form of hexamethylene diisocyanate include Asahi Kasei Chemicals Corporation, trade name: Duranate (registered trademark) TSE-100, trade name: Duranate (registered trademark) TSS-100, and the like.

  The amount of the crosslinking agent is preferably 0.1 equivalents or more, more preferably 0.3 equivalents or more, from the viewpoint of improving the high-speed peelability when the total amount of functional groups of the adhesive polymer is 1 equivalent. From the viewpoint of improving the conformability, it is preferably 2 equivalents or less, more preferably 1.5 equivalents or less.

  The solvent-type re-peeling pressure-sensitive adhesive composition of the present invention can be obtained by mixing a pressure-sensitive polymer and a crosslinking agent. The nonvolatile content in the solvent-type re-peeling pressure-sensitive adhesive composition of the present invention is not particularly limited, but is preferably 10% by mass or more, and more preferably 20% by mass, from the viewpoint of improving dryability and improving productivity. % Or more, more preferably 25% by weight or more, from the viewpoint of improving the coatability, more preferably 50% by weight or more, from the viewpoint of improving the handleability and the coatability by setting an appropriate viscosity, Preferably it is 80 mass% or less, More preferably, it is 70 mass% or less, More preferably, it is 60 mass% or less. In addition, content of the non volatile matter in a solvent-type re-peeling adhesive composition can be suitably adjusted by using the organic solvent used for the said solution polymerization.

  The pressure-sensitive adhesive composition of the present invention includes, for example, a cationic antistatic agent, an anionic antistatic agent, an amphoteric antistatic agent, a nonionic antistatic agent, and an ionic conductivity as long as the object of the present invention is not impaired. You may contain additives, such as antistatic agents, such as a polymer, a crosslinking accelerator, a tackifier, a modifier, a pigment, a coloring agent, a filler, an anti-aging agent, a ultraviolet absorber, and a ultraviolet stabilizer.

  The pressure-sensitive adhesive composition of the present invention can be used for, for example, a re-peeling pressure-sensitive adhesive product. As an adhesive product for re-peeling, for example, an adhesive product in which an adhesive layer is formed on one side of a substrate such as an adhesive tape, an adhesive sheet, and a release paper, an adhesive in which an adhesive layer is formed on both sides of the substrate Examples include products and pressure-sensitive adhesive products having only a pressure-sensitive adhesive layer having no substrate, but the present invention is not limited to such examples.

  The adhesive product for re-peeling is, for example, a method of applying a pressure-sensitive adhesive composition on a substrate, a method of applying a pressure-sensitive adhesive composition to a release paper, and then transferring the applied product onto the substrate, or sticking to a release paper. Although it can manufacture by the method of apply | coating an agent composition etc., this invention is not limited only to this illustration.

  Examples of the base material include paper such as high-quality paper, kraft paper, crepe paper, and glassine paper; films, sheets, and plates made of resin such as polyethylene, polypropylene, polyester, polystyrene, polyvinyl chloride, and cellophane; woven fabric And fiber products such as nonwoven fabrics; and laminates of these. When used for protecting the surface of an optical film, the substrate is preferably a transparent film made of a resin having transparency such as polyester. In addition, from the viewpoint of improving the adhesiveness with the pressure-sensitive adhesive layer formed on the surface of the base material, an easy adhesion treatment such as a corona discharge treatment may be performed on the surface.

  An antistatic layer may be formed on one side or both sides of the base material in order to prevent charging during peeling. The antistatic layer can be formed of the antistatic agent.

  Although the thickness of a base material is not specifically limited, Usually, Preferably it is 200 micrometers or less, More preferably, it is 5-100 micrometers, More preferably, it is 10-50 micrometers.

  Examples of a method for applying the pressure-sensitive adhesive composition of the present invention to a substrate include a roll coating method, a spray coating method, a dipping method, and the like, but the present invention is not limited to such a method.

  Next, an adhesive layer is formed on a base material by drying the applied adhesive composition. Drying can be performed, for example, by heating the pressure-sensitive adhesive layer at a temperature of about 50 to 120 ° C. for a time of about 30 to 180 seconds.

  For example, a release paper may be attached to the pressure-sensitive adhesive layer formed on the substrate. This release paper can be removed when the adhesive product is used. In addition, when winding a substrate having a sheet shape, tape shape or the like having a pressure-sensitive adhesive layer formed on one side in a roll shape, a release agent layer should be formed on the opposite surface of the pressure-sensitive adhesive layer. Thus, the pressure-sensitive adhesive layer can be protected.

  The 180 ° adhesive strength of a pressure-sensitive adhesive product in which a pressure-sensitive adhesive layer made of the pressure-sensitive adhesive composition of the present invention is formed on a 38 μm-thick polyethylene terephthalate film base material is in an atmosphere of 23 ° C. and a relative humidity of 65%. When the peeling speed is 0.3 m / min (low speed peeling) with respect to the acrylic resin plate, it is preferably 0.08 N / 25 mm (adhered body) from the viewpoint of preventing the end of the protective film from being turned up and off. This means that the width of the pressure-sensitive adhesive sheet is 25 mm. The same applies to the following. More preferably, it is 0.11 N / 25 mm or more. From the viewpoint of preventing damage to the body, it is preferably 0.2 N / 25 mm or less, more preferably 0.18 N / mm or less.

  The 180 ° adhesive strength of a pressure-sensitive adhesive product in which a pressure-sensitive adhesive layer made of the pressure-sensitive adhesive composition of the present invention is formed on a 38 μm-thick polyethylene terephthalate film base material is in an atmosphere of 23 ° C. and a relative humidity of 65%. Then, when the peeling speed is 30 m / min (high speed peeling) with respect to the acrylic resin plate, it is preferably 0.1 N / 25 mm or more, more preferably 0.2 N / min. From the viewpoint of reducing resistance during peeling, improving workability, and preventing damage to the adherend, it is preferably 1.5 N / 25 mm or less, more preferably 1.3 N / mm or less. .

  The value obtained by dividing the adhesive force in the high-speed peeling by the adhesive force in the low-speed peeling is preferably 15 or less, more preferably 10 from the viewpoint of enabling easy peeling even when the peeling speed increases. It is as follows. The lower limit of the value obtained by dividing the adhesive force in the high-speed peeling by the adhesive force in the low-speed peeling is not particularly limited, and is preferably as close to 0 as possible.

  In addition, a 4 cm × 4 cm sample cut out from the adhesive product in the same manner as described above was placed in an atmosphere at a temperature of 23 ° C. and a relative humidity of 65%. When placed on an adherend having a surface where the unevenness height difference is 5 to 6 μm placed in a horizontal state, the time until the entire surface of the laminate is wetted with the film (familiar time) is It is preferably 60 seconds or shorter, more preferably 45 seconds or shorter, because it naturally restores when floating or peeling occurs. When measuring the familiarity time, when the sample is placed on the adherend, about 1 to 2 mm from one side of the sample is attached to the adherend by hand in advance, and then the familiarity time is measured.

  The uneven height difference of the surface means the distance between the highest vertex of the convex part and the lowest bottom part of the concave part when the surface of the adherend is analyzed by a laser microscope or the like. In addition, “the entire surface of the sample gets wet with respect to the adherend” means that the air existing between the adhesive product sample and the adherend surface is released and the sample is in close contact with the unevenness of the adherend surface. Say. More specifically, it means that the air existing between the adhesive product sample and the adherend surface is released and the adhesive product sample is in close contact with the adherend surface. When the entire surface of the sample is wet with respect to the adherend, the sample can be seen through, so that the adhesion state can be visually observed.

  The adhesive product for re-peeling of the present invention can also be suitably used for an anti-glare film that is considered to be a film that is difficult to adjust among optical members. The anti-glare film is provided to improve the visibility by suppressing the reflection of light emitted from an external light source such as a fluorescent lamp in an image display such as a liquid crystal display (LCD) or a cathode ray tube display (CRT). Means film. On the surface of the anti-glare film, fine irregularities for diffusing reflected light are formed in order to reduce glare. An anti-glare film is generally applied to a surface of a transparent substrate made of polyester or the like by applying a coating liquid in which a light-transmitting diffusing agent such as silica or resin beads is dispersed in a binder resin. Manufactured by curing by curing or the like. The surface roughness (Ra) of the antiglare film is usually about 0.05 to 0.4 μm.

  As described above, since the pressure-sensitive adhesive composition of the present invention uses the above-mentioned pressure-sensitive adhesive polymer, it is excellent in high-speed peelability, low-speed adhesive strength, and conformability to an adherend. Therefore, the pressure-sensitive adhesive product in which the pressure-sensitive adhesive composition of the present invention is used is an optical member such as an optical polarizing plate (TAC), a retardation plate, an electromagnetic wave (EMI) shield film, an antiglare film, and an antireflection film. In addition to being suitable for use as a re-peeling pressure-sensitive adhesive product for protecting the surface, it can be used as a protective film for the surface of a resin substrate or a metal plate.

  Next, the present invention will be described in more detail based on examples. However, the present invention is not limited to such examples.

In addition, the glass transition temperature of the homopolymer used by each Example etc. is as follows.
Polymethyl acrylate: 10.0 ° C
Polyethyl acrylate: -24 ° C
Polymethyl methacrylate: 105 ° C
Polyvinyl acetate: 30 ° C
Poly n-butyl acrylate: -54.2 ° C
Poly-2-ethylhexyl acrylate: -70.0 ° C
Poly 2-hydroxyethyl acrylate: -15.0 ° C
Poly-4-hydroxybutyl acrylate: -32.0 ° C
Methoxytriethylene glycol acrylate: -50.0 ° C

Preparation Example 1 [Preparation of Macromonomer (E1)]
280 parts of methyl acrylate (parts by mass, the same applies hereinafter), 0.9 part of 2-mercaptoethanol as a chain transfer agent and 521 parts of ethyl acetate as a solvent, thermometer, stirrer, inert gas introduction tube, reflux condenser and dropping Added into a flask equipped with a funnel. While introducing nitrogen gas into the flask under stirring, the internal temperature of the flask was raised to 80 ° C., and 2,2′-azobisisobutyronitrile diluted with 14 parts of ethyl acetate as a polymerization initiator [Nippon Fine Chem. Co., Ltd., product number: ABN-R] 0.14 part was put into the flask to initiate the polymerization reaction.

  After 10 minutes from the start of the polymerization reaction, 420 parts of methyl acrylate, 1.34 parts of 2-mercaptoethanol and 2,2′-azobisisobutyronitrile diluted with 56 parts of ethyl acetate as a polymerization initiator [Japan Finechem Co., Ltd., product number: ABN-R] A mixture of 0.14 part was dropped into the flask over 1 hour. After completion of dropping, the ethyl acetate was added to the flask while washing the dropping funnel with 112 parts of ethyl acetate. Thereafter, aging was carried out at 80 ° C. for 2 hours and 50 minutes, the reaction was terminated, and polymethyl acrylate was obtained.

  Next, 1400 parts of the reaction solution containing polymethyl acrylate obtained above, 2-isocyanatoethyl methacrylate [manufactured by Showa Denko KK, trade name: Karenz (registered trademark) MOI] 3.99 parts, polymerization inhibitor 2,2′-methylenebis (4-methyl-6-tert-butylphenol) [manufactured by Kawaguchi Chemical Industry Co., Ltd., product number: ANTAGE-W400] 0.42 parts and ethyl acetate 42 parts as a dilution / cleaning solvent It added in the flask provided with the meter, the stirrer, the gas introduction pipe | tube, the reflux condenser, and the dropping funnel. While the mixed gas of nitrogen gas and oxygen gas was blown into the contents in the flask under stirring, the internal temperature of the flask was raised to 70 ° C., and dibutyltin dilaurate 0.98 diluted with 14 parts of ethyl acetate as a reaction catalyst. Part was added to initiate addition reaction of 2-isocyanatoethyl methacrylate to polymethyl acrylate. A macromonomer (E1) solution was obtained by performing an addition reaction for 4 hours while maintaining the internal temperature of the flask at 70 ° C.

  The non-volatile content concentration in the obtained macromonomer (E1) solution was 45.8% by mass, the glass transition temperature of the macromonomer (E1) was 10 ° C., and the mass average molecular weight was 45,000. The mass average molecular weight was measured based on the following method (hereinafter the same).

[Measurement method of mass average molecular weight]
As a measuring device for gel permeation chromatography (GPC), Tosoh Co., Ltd., product number: HLC-8220GPC was used, and measurement was performed under the following measurement conditions, and a polystyrene standard sample converted value was defined as a mass average molecular weight.
(Measurement condition)
Column: Tosoh Co., Ltd., product number: TSKgel Super HZM-H x 3 Solvent: Tetrahydrofuran Flow rate: 0.35 mL / min
・ Injection volume: 10 μL / time ・ Sample concentration: 0.2 mass%

Preparation Example 2 [Preparation of Macromonomer (E2)]
In Preparation Example 1, the amount of 2-mercaptoethanol initially charged in the flask was changed to 0.45 parts, and the amount of 2-mercaptoethanol in the dropped monomer was changed to 0.67 parts. A macromonomer (E2) solution was prepared in the same manner as in Preparation Example 1, except that the amount of methacrylate (manufactured by Showa Denko KK, trade name: Karenz (registered trademark) MOI) was changed to 2.00 parts. .

  The solution of the obtained macromonomer (E2) had a nonvolatile content concentration of 46.0% by mass, the macromonomer (E2) had a glass transition temperature of 10 ° C., and a mass average molecular weight of 85,000.

Preparation Example 3 [Preparation of Macromonomer (E3)]
112 parts of methyl acrylate, 168 parts of methyl methacrylate, 0.9 part of 2-mercaptoethanol as a chain transfer agent and 521 parts of ethyl acetate as a solvent, thermometer, stirrer, inert gas introduction tube, reflux condenser and dropping funnel Added into the equipped flask. While introducing nitrogen gas into the flask under stirring, the internal temperature of the flask was raised to 80 ° C., and 2,2′-azobisisobutyronitrile diluted with 14 parts of ethyl acetate as a polymerization initiator [Nippon Fine Chem. Co., Ltd., product number: ABN-R] 0.14 part was put into the flask to initiate the polymerization reaction.

  After 10 minutes from the start of the polymerization reaction, 168 parts of methyl acrylate, 252 parts of methyl methacrylate, 1.34 parts of 2-mercaptoethanol and 2,2′-azobisisodiluted with 56 parts of ethyl acetate as a polymerization initiator. A mixture consisting of 0.14 parts of butyronitrile (manufactured by Nippon Finechem Co., Ltd., product number: ABN-R) was dropped into the flask over 1 hour. After completion of dropping, the ethyl acetate was added to the flask while washing the dropping funnel with 112 parts of ethyl acetate. Thereafter, aging was carried out at 80 ° C. for 2 hours and 50 minutes, the reaction was terminated, and polymethyl acrylate was obtained.

  Next, 1400 parts of the reaction solution containing polymethyl acrylate obtained above, 2-isocyanatoethyl acrylate [manufactured by Showa Denko KK, trade name: Karenz (registered trademark) AOI], 3.63 parts, polymerization inhibitor 2,2′-methylenebis (4-methyl-6-tert-butylphenol) (manufactured by Kawaguchi Chemical Industry Co., Ltd., product number: ANTAGE-W400) 0.42 parts and 42 parts of ethyl acetate as a diluting / cleaning solvent at a temperature of It added in the flask provided with the meter, the stirrer, the gas introduction pipe | tube, the reflux condenser, and the dropping funnel. While the mixed gas of nitrogen gas and oxygen gas was blown into the contents in the flask under stirring, the internal temperature of the flask was raised to 70 ° C., and dibutyltin dilaurate 0.98 diluted with 14 parts of ethyl acetate as a reaction catalyst. Part was added to initiate addition reaction of 2-isocyanatoethyl methacrylate to polymethyl acrylate. A macromonomer (E3) solution was obtained by performing an addition reaction for 4 hours while maintaining the internal temperature of the flask at 70 ° C.

  The non-volatile content concentration in the obtained macromonomer (E3) solution was 46.0 mass%, the glass transition temperature of the macromonomer (E3) was 60 ° C., and the mass average molecular weight was 49,000.

Preparation Example 4 [Preparation of Macromonomer (E4)]
In a flask equipped with 280 parts of vinyl acetate, 0.9 part of 2-mercaptoethanol as a chain transfer agent and 521 parts of ethyl acetate as a solvent, a thermometer, a stirrer, an inert gas introduction tube, a reflux condenser and a dropping funnel. Added. While introducing nitrogen gas into the flask under stirring, the internal temperature of the flask was raised to 80 ° C., and 2,2′-azobisisobutyronitrile diluted with 14 parts of ethyl acetate as a polymerization initiator [Nippon Fine Chem. Co., Ltd., product number: ABN-R] 0.14 part was put into the flask to initiate the polymerization reaction.

  After 10 minutes from the start of the polymerization reaction, 2,2′-azobisisobutyronitrile diluted with 420 parts of vinyl acetate, 1.34 parts of 2-mercaptoethanol and 56 parts of ethyl acetate as a polymerization initiator [Nippon Finechem Co., Ltd., product number: ABN-R] A mixture of 0.14 parts was dropped into the flask over 1 hour. After completion of dropping, the ethyl acetate was added to the flask while washing the dropping funnel with 112 parts of ethyl acetate. Thereafter, aging was carried out at 80 ° C. for 2 hours and 50 minutes, the reaction was terminated, and polymethyl acrylate was obtained.

  Next, 1400 parts of the reaction solution containing polymethyl acrylate obtained above, 2-isocyanatoethyl acrylate [manufactured by Showa Denko KK, trade name: Karenz (registered trademark) AOI], 3.63 parts, polymerization inhibitor 2,2′-methylenebis (4-methyl-6-tert-butylphenol) [manufactured by Kawaguchi Chemical Industry Co., Ltd., product number: ANTAGE-W400] 0.42 parts and ethyl acetate 42 parts as a dilution / cleaning solvent It added in the flask provided with the meter, the stirrer, the gas introduction pipe | tube, the reflux condenser, and the dropping funnel. While the mixed gas of nitrogen gas and oxygen gas was blown into the contents in the flask under stirring, the internal temperature of the flask was raised to 70 ° C., and dibutyltin dilaurate 0.98 diluted with 14 parts of ethyl acetate as a reaction catalyst. Part was added to initiate addition reaction of 2-isocyanatoethyl methacrylate to polymethyl acrylate. A macromonomer (E4) solution was obtained by performing an addition reaction for 4 hours while maintaining the internal temperature of the flask at 70 ° C.

  The non-volatile content concentration in the obtained macromonomer (E4) solution was 43.0% by mass, the glass transition temperature of the macromonomer (E4) was 30 ° C., and the mass average molecular weight was 35,000.

Preparation Example 5 [Preparation of Macromonomer (E5)]
112 parts of ethyl acrylate, 168 parts of methyl methacrylate, 0.9 part of 2-mercaptoethanol as a chain transfer agent and 521 parts of ethyl acetate as a solvent, thermometer, stirrer, inert gas introduction tube, reflux condenser and dropping funnel Added into the equipped flask. While introducing nitrogen gas into the flask under stirring, the internal temperature of the flask was raised to 80 ° C., and 2,2′-azobisisobutyronitrile diluted with 14 parts of ethyl acetate as a polymerization initiator [Nippon Fine Chem. Co., Ltd., product number: ABN-R] 0.14 part was put into the flask to initiate the polymerization reaction.

  After 10 minutes from the start of the polymerization reaction, 168 parts of ethyl acrylate, 252 parts of methyl methacrylate, 1.34 parts of 2-mercaptoethanol and 2,2′-azobisisobuty diluted with 56 parts of ethyl acetate as a polymerization initiator. A mixture composed of ronitrile [manufactured by Nippon Finechem Co., Ltd., product number: ABN-R] 0.14 was dropped into the flask over 1 hour. After completion of dropping, the ethyl acetate was added to the flask while washing the dropping funnel with 112 parts of ethyl acetate. Thereafter, aging was carried out at 80 ° C. for 2 hours and 50 minutes, the reaction was terminated, and polymethyl acrylate was obtained.

  Next, 1400 parts of the reaction solution containing polymethyl acrylate obtained above, 2-isocyanatoethyl acrylate [manufactured by Showa Denko KK, trade name: Karenz (registered trademark) AOI], 3.63 parts, polymerization inhibitor 2,2′-methylenebis (4-methyl-6-tert-butylphenol) [manufactured by Kawaguchi Chemical Industry Co., Ltd., product number: ANTAGE-W400] 0.42 parts and ethyl acetate 42 parts as a dilution / cleaning solvent It added in the flask provided with the meter, the stirrer, the gas introduction pipe | tube, the reflux condenser, and the dropping funnel. While the mixed gas of nitrogen gas and oxygen gas was blown into the contents in the flask under stirring, the internal temperature of the flask was raised to 70 ° C., and dibutyltin dilaurate 0.98 diluted with 14 parts of ethyl acetate as a reaction catalyst. Part was added to initiate addition reaction of 2-isocyanatoethyl methacrylate to polymethyl acrylate. A macromonomer (E5) solution was obtained by performing an addition reaction for 4 hours while maintaining the internal temperature of the flask at 70 ° C.

  The non-volatile content concentration in the obtained macromonomer (E5) solution was 45.5% by mass, the glass transition temperature of the macromonomer (E5) was 40 ° C., and the mass average molecular weight was 52,000.

Production Example 1 [Production of Adhesive Polymer A]
Macromonomer (E1) in a non-volatile content of 120 parts, 368 parts of 2-ethylhexyl acrylate, 20 parts of n-butyl acrylate, 12 parts of 2-hydroxyethyl acrylate, 0.6 part of n-dodecyl mercaptan as a chain transfer agent and 320 parts of ethyl acetate The parts were mixed well and the resulting mixture was added into a flask equipped with a thermometer, stirrer, inert gas inlet tube, reflux condenser and dropping funnel. While introducing nitrogen gas into the flask under stirring, the internal temperature of the flask was raised to 89 ° C., and 2,2′-azobis (2-methylbutyronitrile) diluted with 4 parts of ethyl acetate as a polymerization initiator [Nippon Finechem Co., Ltd., product number: ABN-E] 0.08 part was charged into the flask to initiate the polymerization reaction.

  After 1 hour from the start of the polymerization reaction, 2,2′-azobis (2-methylbutyronitrile) diluted with 4 parts of ethyl acetate as a polymerization initiator [manufactured by Nippon Finechem Co., Ltd., product number: ABN-E] 0.04 part was added into the flask. 2,2′-azobisisobutyronitrile diluted with 36.8 parts of ethyl acetate as a booster (post-added polymerization initiator) from 3 to 4 hours after the start of the polymerization reaction [Nippon Finechem ( Co., Ltd., product number: ABN-R] 1.2 parts were added in three portions. Then, the reaction solution of adhesive polymer A was obtained by further aging for 2 hours while adjusting the internal temperature of the flask to 78 ° C.

  The non-volatile content concentration in the reaction solution of the obtained adhesive polymer A is 50.8% by mass, and the viscosity when the non-volatile content concentration is 50% by mass (25 ° C. using a B-type viscometer, rotor No. 3). The viscosity of the adhesive polymer A obtained was 1600 mPa · s, the mass average molecular weight of the obtained adhesive polymer A was 138,000, the glass transition temperature was −68 ° C., and the ratio of the macromonomer in the adhesive polymer A Was 23.1% by mass.

Production Example 2 [Production of Adhesive Polymer B]
In Production Example 1, as a mixture, 80 parts of macromonomer (E1) (nonvolatile amount), 308 parts of 2-ethylhexyl acrylate, 12 parts of 2-hydroxyethyl acrylate, methoxytriethylene glycol acrylate [manufactured by Kyoeisha Chemical Co., Ltd., product number: MTG-A] Adhesive in the same manner as in Production Example 1 except that a mixture obtained by thoroughly mixing 80 parts, 0.08 part of n-dodecyl mercaptan and 320 parts of ethyl acetate as a chain transfer agent was used. A reaction solution of the conductive polymer B was obtained.

  The non-volatile content concentration in the reaction solution of the obtained adhesive polymer B is 50.5% by mass, and the viscosity when the non-volatile content concentration is 50% by mass (25 ° C. using a B-type viscometer, rotor No. 3). The viscosity of the adhesive polymer B obtained is 2200 mPa · s, the weight average molecular weight of the obtained adhesive polymer B is 263,000, the glass transition temperature is −65 ° C., and the ratio of the macromonomer in the adhesive polymer B Was 16.7% by mass.

Production Example 3 [Production of Adhesive Polymer C]
In Production Example 1, 80 parts of macromonomer (E2) (nonvolatile content), 368 parts of 2-ethylhexyl acrylate, 20 parts of n-butyl acrylate, 12 parts of 2-hydroxyethyl acrylate, methoxytriethylene glycol acrylate [Kyoeisha Chemical Co., Ltd.] Manufactured by Co., Ltd., product number: MTG-A], except that a mixture obtained by thoroughly mixing 0.8 parts of n-dodecyl mercaptan and 320 parts of ethyl acetate as a chain transfer agent was used. In the same manner as in Example 1, a reaction solution of adhesive polymer C was obtained.

  The non-volatile content concentration in the reaction solution of the obtained adhesive polymer C was 50.2% by mass, and the viscosity when the non-volatile content concentration was 50% by mass (25 ° C. using a B-type viscometer, rotor No. 3). The viscosity of the adhesive polymer C obtained is 1850 mPa · s, the mass average molecular weight of the obtained adhesive polymer C is 142,000, the glass transition temperature is −68 ° C., and the ratio of the macromonomer in the adhesive polymer C Was 16.7% by mass.

Production Example 4 [Production of Adhesive Polymer D]
In Production Example 1, instead of 120 parts (nonvolatile content) of macromonomer (E2), 120 parts (nonvolatile content) of macromonomer (E3) was used in the same manner as Production Example 1, except that the adhesive polymer D A reaction solution was obtained.

  The non-volatile content concentration in the reaction solution of the obtained adhesive polymer D was 50.6% by mass, and the viscosity when the non-volatile content concentration was 50% by mass (B type viscometer, rotor No. 3 was used at 25 ° C. The viscosity of the adhesive polymer D obtained is 1700 mPa · s, the mass average molecular weight of the obtained adhesive polymer D is 16,000, the glass transition temperature is −68 ° C., and the ratio of the macromonomer in the adhesive polymer D Was 23.1% by mass.

Production Example 5 [Production of Adhesive Polymer E]
In Production Example 1, as a mixture, 120 parts of macromonomer (E4) (non-volatile content), 365 parts of 2-ethylhexyl acrylate, 20 parts of n-butyl acrylate, 15 parts of 2-hydroxybutyl acrylate, n-dodecyl mercaptan as a chain transfer agent A reaction solution of adhesive polymer E was obtained in the same manner as in Production Example 1 except that a mixture obtained by sufficiently mixing 0.6 part and 320 parts of ethyl acetate was used.

  The non-volatile content concentration in the reaction solution of the obtained adhesive polymer E is 50.5% by mass, and the viscosity when the non-volatile content concentration is 50% by mass (25 ° C. using a B-type viscometer, rotor No. 3). The viscosity of the adhesive polymer E is 1900 mPa · s, the weight average molecular weight of the obtained adhesive polymer E is 130,000, the glass transition temperature is −68 ° C., and the ratio of the macromonomer in the adhesive polymer E Was 23.1% by mass.

Production Example 6 [Production of Adhesive Polymer F]
In Production Example 5, instead of 120 parts (nonvolatile content) of macromonomer (E4), 120 parts (nonvolatile content) of macromonomer (E5) was used, and in the same manner as Production Example 5, the adhesive polymer F A reaction solution was obtained.

  The non-volatile content concentration in the reaction solution of the obtained adhesive polymer F is 50.8% by mass, and the viscosity when the non-volatile content concentration is 50% by mass (25 ° C. using a B-type viscometer, rotor No. 3). The viscosity of the adhesive polymer F obtained is 2100 mPa · s, the mass average molecular weight of the obtained adhesive polymer F is 152,000, the glass transition temperature is −68 ° C., and the ratio of the macromonomer in the adhesive polymer F Was 23.1% by mass.

Production Example 7 (Production of adhesive polymer G)
2-ethylhexyl acrylate 265.12 parts, n-butyl acrylate 80 parts, 4-hydroxybutyl acrylate 14.9 parts, methoxytriethylene glycol acrylate [manufactured by Kyoeisha Chemical Co., Ltd., product number: MTG-A] 40 parts, chain transfer As a reagent, 0.32 part of n-dodecyl mercaptan and 384 parts of ethyl acetate were thoroughly mixed, and the resulting mixture was placed in a flask equipped with a thermometer, a stirrer, an inert gas introduction tube, a reflux condenser and a dropping funnel. Added to. While introducing nitrogen gas into the flask under stirring, the internal temperature of the flask was raised to 92 ° C., and 2,2′-azobis (2-methylbutyrodiluted with 0.9 part of ethyl acetate as a polymerization initiator was used. Nitrile) [manufactured by Nippon Finechem Co., Ltd., product number: ABN-E] 0.1 part was charged into the flask to initiate the polymerization reaction.

  One hour after the initiation of the polymerization reaction, 2,2′-azobis (2-methylbutyronitrile) diluted with 1.8 parts of ethyl acetate as a polymerization initiator [manufactured by Nippon Finechem Co., Ltd., product number: ABN- E] 0.2 part was added into the flask. 2,2′-azobis (2,4-dimethyl) diluted with 7.2 parts of ethyl acetate as a booster (post-added polymerization initiator) from 3.5 hours to 5 hours after the start of the polymerization reaction 0.8 parts of valeronitrile) [manufactured by Nippon Finechem Co., Ltd., product number: ABN-V] was added in four portions. Then, the reaction solution of adhesive polymer G was obtained by further aging for 2 hours while adjusting the internal temperature of the flask to 78 ° C.

  The concentration of the non-volatile content in the reaction solution of the obtained adhesive polymer G is 50.0% by mass, and the viscosity when the non-volatile content is 50% by mass (25 ° C. using a B-type viscometer, rotor No. 3). The viscosity of the adhesive polymer G obtained is 2400 mPa · s, the weight average molecular weight of the obtained adhesive polymer G is 485 thousand, the glass transition temperature is −64 ° C., and the ratio of the macromonomer in the adhesive polymer G Was 0% by mass because no macromonomer was used.

Production Example 8 [Production of Adhesive Polymer H]
In Production Example 7, 268 parts of 2-ethylhexyl acrylate, 120 parts of n-butyl acrylate, 12 parts of 2-hydroxyethyl acrylate, 0.32 part of n-dodecyl mercaptan and 384 parts of ethyl acetate as a chain transfer agent A reaction solution of adhesive polymer H was obtained in the same manner as in Production Example 7, except that the mixture obtained by mixing was used.

  The non-volatile content concentration in the reaction solution of the obtained adhesive polymer H is 50.8% by mass, and the viscosity when the non-volatile content concentration is 50% by mass (25 ° C. using a B-type viscometer, rotor No. 3). The viscosity of the resulting adhesive polymer H is 49,800,000, the glass transition temperature is −64 ° C., and the ratio of the macromonomer in the adhesive polymer H is 5600 mPa · s. Was 0% by mass because no macromonomer was used.

Examples 1 to 7 and Comparative Examples 1 to 6 (Preparation of pressure-sensitive adhesive composition)
After diluting the adhesive polymer reaction solution with ethyl acetate so that the nonvolatile content in the adhesive polymer reaction solution obtained in each production example was 34% by mass, 100 parts of the adhesive polymer were crosslinked with A pressure-sensitive adhesive composition was prepared by mixing 250 ppm (by mass) of dibutyltin dilaurate as an accelerator and a cross-linking agent shown in Table 1 and stirring sufficiently.

  In addition, “equivalent to the hydroxyl group” described in Table 1 means an equivalent of the isocyanate group of the crosslinking agent to the hydroxyl group of the adhesive polymer.

Example 8
In Example 3 , the amount of the macromonomer (E1) used in the monomer component constituting the adhesive polymer B was changed from 80 parts (nonvolatile content) to 40 parts (nonvolatile content), and methoxytriethylene glycol acrylate [ A pressure-sensitive adhesive composition was prepared in the same manner as in Example 3 except that the amount of Kyoeisha Chemical Co., Ltd., product number: MTG-A] was changed from 80 parts to 120 parts (adhesive polymer I). Prepared.

Example 9
In Example 3 , the amount of the macromonomer (E1) used in the monomer component constituting the adhesive polymer B was changed from 80 parts (nonvolatile content) to 120 parts (nonvolatile content), and methoxytriethylene glycol acrylate [ A pressure-sensitive adhesive composition was prepared in the same manner as in Example 3 except that the amount of Kyoeisha Chemical Co., Ltd., product number: MTG-A] was changed from 80 parts to 40 parts (adhesive polymer J). Prepared.

Experimental Example A polyethylene terephthalate film (manufactured by Toray Industries, Inc.) having a thickness of 38 μm was used as a base material, and the pressure-sensitive adhesive composition obtained in each example or each comparative example had a thickness after drying of 20 μm. After the coating, an adhesive film was produced by drying at 100 ° C. for 2 minutes.

  A polyethylene terephthalate film that had been subjected to a release treatment was attached to the surface of the pressure-sensitive adhesive film on which the layer of the pressure-sensitive adhesive composition was formed, and was then cured in an atmosphere at 23 ° C. for 1 week.

  Next, the cured adhesive film was allowed to stand for 24 hours at 23 ° C. in an atmosphere with a relative humidity of 65%, and then cut to an appropriate length with a width of 25 mm to prepare a test tape. The following physical properties were measured using the obtained test tape. The results are shown in Table 1.

(1) Adhesive force during low-speed peeling In an atmosphere of a temperature of 23 ° C. and a relative humidity of 65%, a test tape is attached to a 3 mm thick acrylic resin plate (manufactured by Nippon Test Panel Co., Ltd., standard test plate) with a rubber roller (mass: 2 kg) and reciprocated for 1 minute and allowed to stand for 25 minutes.

  Thereafter, the 180 ° peel adhesive strength was measured at a peel rate of 0.3 m / min in an atmosphere of 23 ° C. according to JIS K 6854, and evaluated based on the following evaluation criteria.

(Evaluation criteria)
○: Adhesive strength is 0.11 N / 25 mm or more Δ: Adhesive strength is 0.08 N / 25 mm or more and less than 0.11 N / 25 mm ×: Adhesive force is less than 0.08 N / 25 mm

(2) High-speed peelability In an atmosphere at a temperature of 23 ° C. and a relative humidity of 65%, a test tape is placed on a 3 mm thick acrylic resin plate (manufactured by Nippon Test Panel Co., Ltd., standard test plate) with a rubber roller (mass: 2 kg). The sample was reciprocated once for pressure bonding and left for 25 minutes.

  Thereafter, the 180 ° peel adhesive strength was measured at a peel rate of 30 m / min in an atmosphere of 23 ° C. in accordance with JIS K 6854, and evaluated based on the following evaluation criteria.

(Evaluation criteria)
○: Adhesive strength is 1.3 N / 25 mm or less △: Adhesive strength exceeds 1.3 N / 25 mm and 1.5 N / 25 mm or less ×: Adhesive strength exceeds 1.5 N / 25 mm

(3) Ratio of adhesive strength at high speed peeling to adhesive strength at low speed peeling (“High speed / Low speed” in Table 1)
Based on the results of the adhesive force at the time of high speed peeling and the adhesive force at the time of low speed peeling determined in the above (1) and (2), by dividing the adhesive force at the time of high speed peeling by the adhesive force at the time of low speed peeling, The value of the ratio between the adhesive strength at high speed peeling and the adhesive strength at low speed peeling was determined and evaluated based on the following evaluation criteria.

(Evaluation criteria)
○: The value of the ratio of the adhesive force at the time of high speed peeling to the adhesive strength at the time of the low speed peeling is 10 or less. Δ: The value of the ratio of the adhesive strength at the time of high speed peeling to the adhesive strength at the time of low speed peeling exceeds 10 and is 15 or less. X: The ratio value of the adhesive strength at the time of high speed peeling and the adhesive strength at the time of low speed peeling exceeds 15.

(4) Conformability The test tape was cut to produce a 4 cm × 4 cm test piece, and the width of about 1 to 2 mm from the end of one side of the test piece in an atmosphere at a temperature of 23 ° C. and a relative humidity of 65%. Liquid crystal protective film which is an anti-glare film placed in a horizontal state [manufactured by Buffalo Co., Ltd., product number: BOF-H141S, surface roughness (Ra): 0.35 μm, uneven height difference: 5.7 μm (laser The sample was gently placed on the liquid crystal protective film, and the test piece began to get wet with the liquid crystal protective film after bonding to the rough surface of the microscope: manufactured by Keyence Corporation, product number: value measured with VK-9710] The time required for the entire test piece to be completely adapted to the liquid crystal protective film (hereinafter referred to as “familiar time”) was measured and evaluated based on the following evaluation criteria.

(Evaluation criteria)
○: Familiar time is less than 40 seconds Δ: Familiar time is 40 seconds or longer and less than 60 seconds X: Familiar time is 60 seconds or longer

In addition, the symbol in Table 1 means the following.
C1: Hexamethylene diisocyanate bifunctional prepolymer [manufactured by Asahi Kasei Co., Ltd., trade name: Duranate (registered trademark) D-201]
C2: Hexamethylene diisocyanate adduct (manufactured by Nippon Polyurethane Industry Co., Ltd., trade name: Coronate HL)
C3: Isocyanurate of hexamethylene diisocyanate [Asahi Kasei Co., Ltd., trade name: Duranate (registered trademark) TSE-100]
C4: isocyanurate of hexamethylene diisocyanate [Asahi Kasei Co., Ltd., trade name: Duranate (registered trademark) TSS-100]
C5: Tolylene diisocyanate adduct body (manufactured by Nippon Polyurethane Industry Co., Ltd., trade name: Coronate L)
C6: Hexamethylene diisocynate biuret [Asahi Kasei Co., Ltd., trade name: Duranate (registered trademark) 24A-100]

From the results shown in Table 1, according to each example, a pressure-sensitive adhesive composition excellent in the balance of high-speed peelability, adhesive strength at the time of low-speed peel and conformability was obtained , and the pressure-sensitive adhesive obtained in each example Since the isocyanurate is used as the crosslinking agent in the agent composition, it can be seen that the agent composition is more excellent in the balance between the high-speed release property, the adhesive force at the time of low-speed release, and the conformability.

Claims (6)

A solvent-type re-peeling pressure-sensitive adhesive composition containing a pressure-sensitive adhesive polymer and a crosslinking agent, wherein the pressure-sensitive adhesive polymer contains at least one of vinyl acetate and methyl (meth) acrylate in an amount of 50% by mass or more. A macromonomer having one radical polymerizable unsaturated double bond at the terminal and having a glass transition temperature of 0 to 160 ° C., and an alkyl having an alkyl group having 4 to 12 carbon atoms ( It is a graft copolymer obtained by polymerizing a monomer component containing a (meth) acrylate and a functional group-containing monomer, and having a graft side chain made of a polymer having a glass transition temperature of 0 to 160 ° C. as a side chain, and the crosslinking agent Is a solvent type re-peeling pressure-sensitive adhesive composition, characterized in that isocyanurate. The pressure-sensitive adhesive composition for solvent-type re-peeling according to claim 1 , wherein the polymer constituting the graft side chain has a mass average molecular weight of 15,000 to 100,000. Monomer component, to claim 1 or 2 which further comprises at least one motor Nomar selected from the group consisting of (meth) acrylate containing a long chain alkyl group having an alkylene oxide group-containing monomer and 16 to 22 carbon atoms The solvent-type re-peeling pressure-sensitive adhesive composition according to the description. The alkylene oxide group-containing monomer is an alkylene oxide group-containing (meth) acrylate and formula (I):
(In the formula, R ¹ is an alkenyl group having 2 to 5 carbon atoms, R ² is a hydrogen atom or a monovalent hydrocarbon group having 1 to 8 carbon atoms, and any of R ³ and R ⁴ is a hydrogen atom. Is a methyl group or both are hydrogen atoms, p is a number from 1 to 50)
The solvent-type re-peeling pressure-sensitive adhesive composition according to claim 3 , which is at least one monomer selected from the group consisting of an alkylene oxide group-containing monomer represented by: Solvent-removable pressure-sensitive adhesive article comprising formed on at least one surface of the removable pressure-sensitive adhesive adhesive layer which is formed by the composition substrate according to any one of claims 1-4. The adhesive product for re-peeling according to claim 5 , wherein the use is a surface protective film for optical members.