CN115181530A - Adhesive, adhesive sheet, and laminate - Google Patents

Abstract

The invention provides an adhesive, an adhesive sheet and a laminated body, which can form an adhesive layer with good yield and difficult reduction of removability after high temperature time. The adhesive comprises: a urethane polyol (A) having a weight average molecular weight of 10 to 50 ten thousand as a reaction product of a polyol (a) and a polyisocyanate (B), an isocyanate curing agent (B), an antioxidant (D), an antistatic agent (E), and a polyfunctional polyol (F). Further, the number of hydroxyl groups in one molecule of the polyfunctional polyol (F) is preferably 3 or more.

Description

Adhesive, adhesive sheet, and laminate

The invention is a divisional application of invention patent application with application number 201811523267.3 and invention name "adhesive, adhesive sheet and laminate" which is proposed in 2018, 12 and 13.

Technical Field

The invention relates to an adhesive with antistatic property. Also disclosed are an adhesive sheet and a laminate using such an adhesive.

Background

Display devices such as Flat Panel Displays (FPDs) such as Liquid Crystal Displays (LCDs) and Organic Light Emitting Displays (OLEDs), and touch screen displays (TSPs) in which FPDs and touch screens are combined are widely used in Televisions (TVs), personal Computers (PCs), portable information terminals, and the like.

Conventionally, surface protection sheets have been widely used to protect optical members used in display devices from scratches, dust adhesion, and the like.

An adhesive containing a urethane resin (hereinafter referred to as a urethane adhesive) is used in an adhesive layer of a surface protective sheet because it has excellent proper adhesive force and removability for various adherends such as glass. Such a surface protective sheet may require antistatic performance in order to prevent damage to electronic devices inside the FPD or TSP due to static electricity generated when the sheet is peeled from the adherend.

Patent document 1 discloses a urethane adhesive composition containing a hydroxyl group-containing polyurethane resin (a), a polyfunctional isocyanate compound (B), a compound (C) having a molecular weight of 250 to 1000 and no hydroxyl group or isocyanate group, and an ionic compound (D), and containing 0.05 to 5 parts by weight of the component (D) per 100 parts by weight of the total of the components (a) to (C).

Patent document 2 discloses a urethane adhesive containing a polyurethane resin obtained by hardening a composition containing a polyol (a) and a polyfunctional isocyanate compound (B), wherein the equivalent ratio of NCO groups to OH groups in the polyol (a) and the polyfunctional isocyanate compound (B) is more than 1.0 and 5.0 or less in terms of NCO groups/OH groups, and the urethane adhesive contains an ionic liquid containing a fluorine organic anion.

[ Prior art documents ]

[ patent document ]

[ patent document 1] Japanese patent laid-open publication No. 2017-105866

[ patent document 2] Japanese patent laid-open No. 2015-098503

Disclosure of Invention

[ problems to be solved by the invention ]

However, although the conventional adhesive has required antistatic properties by including an antistatic agent, the metal catalyst in the adhesive coordinates with the antistatic agent to decrease the reaction rate of the isocyanate curing agent, and thus the curing rate is decreased. Further, if the surface protection sheet is manufactured not sheet by sheet but roll-to-roll (roll-to-roll), a step generated when the leading end of the surface protection sheet is attached to a winding roll of the coating apparatus is applied to the adhesive layer by a winding pressure and is wound, and therefore, the influence of the step remains in the adhesive layer as an indentation. Therefore, the surface protection sheet needs to be discarded until the indentations disappear. Further, the decrease in the curing rate caused by the blending of the antistatic agent decreases the cohesive force of the adhesive layer immediately after application, and therefore, there are the following problems: the sheet length until the indentation disappears increases, and the yield of the surface protection sheet decreases. In addition, the decrease in the hardening speed has the following problems: the crosslinking density of the pressure-sensitive adhesive layer is reduced, and the adhesive strength after the lapse of high temperature is increased, thereby reducing the removability. Further, the adhesive of patent document 2 is produced by a so-called one-shot method (one-shot method) without using a urethane polyol, and therefore, the cohesive force of the adhesive layer immediately after application is low and the yield is poor.

The invention aims to provide an adhesive, an adhesive sheet and a laminated body, which can form an adhesive layer with good yield and difficult reduction of removability after high temperature time.

[ means for solving problems ]

The present inventors have made extensive studies to solve the above problems, and as a result, have found that the above problems can be solved by the following embodiments, thereby completing the present invention.

[1] An adhesive, comprising: urethane polyol (A) having a weight average molecular weight of 10 to 50 ten thousand as a reactant of polyol (a) and polyisocyanate (B), isocyanate curing agent (B), antioxidant (D), antistatic agent (E), and polyfunctional polyol (F).

[2] The adhesive according to [1], wherein the number of hydroxyl groups in one molecule of the polyfunctional polyol (F) is 3 or more.

[3] The adhesive according to [1] or [2], which further comprises a plasticizer (C).

[4] The adhesive according to [3], wherein the plasticizer (C) is contained in an amount of 0.1 to 100 parts by mass based on 100 parts by mass of the urethane polyol (A).

[5] The adhesive according to any one of [1] to [4], wherein the polyfunctional polyol (F) is contained in an amount of 2 to 50 parts by mass with respect to 100 parts by mass of the urethane polyol (A).

[6] The adhesive according to any one of [1] to [5], wherein the polyfunctional polyol (F) has a primary hydroxyl group at a terminal.

[7] An adhesive sheet, comprising: a substrate, and an adhesive layer which is a cured product of the adhesive according to any one of [1] to [6 ].

[8] A laminate, comprising: a member selected from the group consisting of a transparent conductive film, glass, acrylic plate, polycarbonate plate, olefin plate, and inorganic barrier layer; and the adhesive sheet according to [7 ].

[ Effect of the invention ]

According to the present invention, an adhesive sheet, and a laminate are provided, which can form an adhesive layer having a good yield and a low tendency to decrease in removability after a lapse of time at a high temperature.

Detailed Description

Before describing the present invention, terms are defined. In the present specification, the adherend refers to an object to which the adhesive tape is attached. The adhesive sheet includes: a substrate, and an adhesive layer comprising a cured product of the adhesive of the present specification. In addition, "tape", "film" and "sheet" have the same meaning. The main component is a component that is blended in the largest amount among a plurality of blended components.

In the present specification, unless otherwise specified, "molecular weight" refers to number average molecular weight (Mn). The "Mn" is a polystyrene-equivalent number average molecular weight determined by Gel Permeation Chromatography (GPC).

The adhesive of the present embodiment includes: urethane polyol (A) having a weight average molecular weight of 10 to 50 ten thousand as a reactant of polyol (a) and polyisocyanate (B), isocyanate curing agent (B), antioxidant (D), antistatic agent (E), and polyfunctional polyol (F).

The adhesive of the present embodiment is preferably used as an adhesive sheet in which an adhesive layer is formed by coating. The adhesive sheet preferably includes a substrate.

The adhesive of the present embodiment can eliminate the disadvantage of the decrease in the curing rate caused by the formulation of the antistatic agent (E) by setting the weight average molecular weight of the urethane polyol (a) high and combining it with the polyfunctional polyol (F), thereby improving the decrease in the yield. Further, the adhesive of the present embodiment contains the antioxidant (D) to obtain an adhesive layer which is less likely to decrease in removability after the lapse of time at a high temperature.

The adhesive of the present embodiment can be used for displays such as LCD and OLED having a flat portion or a curved portion, and touch panels using the displays. In addition, the present invention is widely applicable to surface protection of electronic devices such as mobile phones, smart phones, mobile terminals of tablet terminals, and computers equipped with such displays and touch panels.

The material of the adherend is not limited to glass, and may be used for protection of materials that are easily damaged, such as polyolefin, gold, silver, copper, and Indium Tin Oxide (ITO).

In addition, the adhesive is used for, for example, members such as window glass, light Emitting Diode (LED), vehicle, and wiring, and laminates thereof, in addition to displays.

The pressure-sensitive adhesive sheet of the present embodiment can also be used for protection in the production steps of various members and for products after production. The adhesive of the present embodiment can be used for applications other than surface protection.

(urethane polyol (A))

The urethane polyol (a) is a reaction product obtained by subjecting one or more polyols (a) and one or more polyisocyanates (b) to a urethanization reaction. The polyisocyanate (b) is preferably a difunctional isocyanate (b 1) (also referred to as a diisocyanate) having two isocyanate groups in one molecule. The polyol (a) is preferably a polyol (a 1) having two or more hydroxyl groups in one molecule. The isocyanate groups (isocyanate groups) of the polyisocyanate (b) are used in a molar ratio (NCO/OH ratio) which is less than that of the hydroxyl groups of the polyol (a). Thereby, a urethane polyol having a hydroxyl group can be obtained. In the urethane reaction, a catalyst is preferably used to promote the reaction. A solvent may be used as necessary in the carbamation reaction.

The urethane polyol (A) may be used alone or in combination of two or more.

< polyol (a) >

The polyol (a) is a compound having two or more hydroxyl groups. The polyol (a) is preferably a polyol such as a polyether polyol, a polyester polyol, a polybutadiene modified polyol, a polycarbonate polyol, or a castor oil polyol, and more preferably a polyether polyol, a polyester polyol, or a polybutadiene modified polyol.

The polyol (a) of the present embodiment may be one type, and when two or more types are used in combination, the cohesive force and the adhesive force of the adhesive layer can be easily adjusted. In the case of using one kind of polyol (a), it is preferable to use a polyol having 3 or more hydroxyl groups. In the case of using two or more kinds of polyols (a), it is preferable to use a polyol having two hydroxyl groups and a polyol having three or more hydroxyl groups in combination. In the case of using a polyol having three or more hydroxyl groups in combination, the NCO/OH ratio (molar ratio) of the polyisocyanate (b) to the polyol (a) is preferably set to 0.80 or less. When the NCO/OH ratio (molar ratio) is used in an appropriate range, the reaction can be easily controlled in the synthesis of the urethane polyol (a).

Examples of the polyether polyol include a reaction product obtained by addition polymerization of one or more oxirane compounds using an active hydrogen-containing compound having two or more active hydrogens in one molecule as an initiator.

The active hydrogen-containing compound is preferably a hydroxyl-containing compound, an amine, or the like.

Examples of the hydroxyl group-containing compound include: difunctional active hydrogen-containing compounds such as Ethylene Glycol (EG), propylene Glycol (PG), 1, 4-butanediol, neopentyl Glycol, butyl ethyl pentanediol, and the like; trifunctional active hydrogen-containing compounds such as glycerin and trimethylolpropane; tetrafunctional active hydrogen-containing compounds such as pentaerythritol, and the like.

Examples of amines include: difunctional active hydrogen-containing compounds such as N-aminoethylethanolamine, isophoronediamine, xylylenediamine, and the like; trifunctional active hydrogen-containing compounds such as triethanolamine; tetrafunctional active hydrogen-containing compounds such as ethylenediamine and aromatic diamines; and pentafunctional active hydrogen-containing compounds such as diethylenetriamine.

Examples of the oxirane compound include: alkylene Oxide (AO) such as Ethylene Oxide (EO), propylene Oxide (PO), and Butylene Oxide (BO); tetrahydrofuran (THF), and the like.

The polyether polyol is preferably an alkyleneoxy group derived from an active hydrogen-containing compound in the molecule (the polyol is also referred to as "polyoxyalkylene polyol"). The hydroxyl group-containing compound constituting the polyoxyalkylene polyol is preferably a polyether polyol such as polyethylene glycol, polypropylene glycol, polytetramethylene glycol, or the like, and particularly preferably polypropylene glycol having low crystallinity and easily exhibiting flexibility.

The number average molecular weight (Mn) of the polyether polyol is not particularly limited, but is preferably 200 to 6,000, more preferably 400 to 5,000, and still more preferably 600 to 4,000, from the viewpoint of easily developing transparency and flexibility. When Mn is 200 or more, the reaction control at the time of synthesizing the urethane polyol (a) is facilitated. Further, by setting Mn to 6,000 or less, the cohesive force of the urethane polyol (a) can be easily adjusted to an appropriate range.

The polyester polyol is preferably a compound (esterified product) obtained by esterification reaction of one or more polyol components and one or more acid components, a compound (ring-opening polymer) synthesized by ring-opening polymerization of an lactone, or the like.

Examples of lactones are: polycaprolactone, poly (beta-methyl-gamma-valerolactone), and polypentanolactone, and the like.

Examples of the polyol component include, in addition to the active hydrogen-containing compound: diethylene glycol, 1, 3-butanediol, 3-methyl-1, 5-pentanediol, 2-butyl-2-ethyl-1, 3-propanediol, 2, 4-diethyl-1, 5-pentanediol, 1, 2-hexanediol, 1, 6-hexanediol, 2-ethyl-1, 3-hexanediol, 1, 8-octanediol, 1, 9-nonanediol, 2-methyl-1, 8-octanediol, 1, 8-decanediol, octadecanediol, hexanetriol, etc.

Examples of the acid component include: succinic acid, methylsuccinic acid, adipic acid, pimelic acid, azelaic acid, sebacic acid, 1, 12-dodecanedioic acid, 1, 14-tetradecanedioic acid, 2-methyl-1, 4-cyclohexanedicarboxylic acid, 2-ethyl-1, 4-cyclohexanedicarboxylic acid, terephthalic acid, isophthalic acid, phthalic acid, 1, 4-naphthalenedicarboxylic acid, 4' -biphenyldicarboxylic acid, dimer acids, trimer acids, acid anhydrides thereof, and the like.

The number average molecular weight (Mn) of the polyester polyol is preferably 200 to 6,000, more preferably 500 to 6,000, still more preferably 500 to 4,000, and particularly preferably 500 to 3,000. When Mn is 200 or more, the reaction control at the time of synthesizing the urethane polyol (a) is facilitated. Further, by setting Mn to 6,000 or less, the cohesive force of the urethane polyol (a) can be easily adjusted to an appropriate range.

The polybutadiene-modified polyol is, for example, a linear or branched polybutadiene having two or more hydroxyl terminals, a1, 2-vinyl moiety, a1, 4-cis moiety, a1, 4-trans moiety, or a hydrogenated structure thereof.

The number average molecular weight (Mn) of the polybutadiene-modified polyol is preferably 200 to 6,000, more preferably 500 to 6,000, still more preferably 500 to 4,000, and particularly preferably 500 to 3,000. When Mn is 200 or more, the reaction control at the time of synthesizing the urethane polyol (a) is facilitated. Further, by setting Mn to 6,000 or less, the cohesive force of the urethane polyol (a) can be easily adjusted to an appropriate range.

The degree of hydrogenation of the polybutadiene-modified polyol is preferably such that all of the double bond sites present before hydrogenation are hydrogenated, but in the present invention, a small amount of double bond sites may remain.

Examples of the other polyols than the above-mentioned polyols include polycarbonate polyols, castor oil polyols, and the like. The other polyols are preferably used in combination with polyether polyols or polyester polyols.

The number average molecular weight (Mn) of the other polyhydric alcohols is about 200 to 6,000.

Further, since the polyol (a) containing an acidic functional group such as a carboxyl group or a sulfo group may corrode an adherend, it is preferable to use a polyol having no acidic functional group.

Among these, the polyol (a) is preferably aliphatic, and thus, the removability after the high temperature test is further improved and the transparency of the adhesive layer is easily maintained.

< polyisocyanate (b) >

As the polyisocyanate (b), for example, known polyisocyanates such as aromatic polyisocyanate, aliphatic polyisocyanate, aromatic aliphatic polyisocyanate and alicyclic polyisocyanate can be used.

Examples of the aromatic polyisocyanate include: 1, 3-phenylene diisocyanate, 4' -diphenyl diisocyanate, 1, 4-phenylene diisocyanate, 4' -diphenylmethane diisocyanate, 2, 4-tolylene diisocyanate, 2, 6-tolylene diisocyanate, 4' -toluidine diisocyanate, 2,4, 6-triisocyanate toluene, 1,3, 5-triisocyanate benzene, dianisidine diisocyanate, 4' -diphenyl ether diisocyanate, and 4,4',4 "-triphenylmethane triisocyanate, and the like.

Examples of the aliphatic polyisocyanate include: trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, pentamethylene diisocyanate, 1, 2-propylene diisocyanate, 2, 3-butylene diisocyanate, 1, 3-butylene diisocyanate, dodecamethylene diisocyanate, and 2, 4-trimethylhexamethylene diisocyanate, and the like.

Examples of the aromatic aliphatic polyisocyanate include: omega, omega '-diisocyanate-1, 3-dimethylbenzene, omega' -diisocyanate-1, 4-diethylbenzene, 1, 4-tetramethylxylene diisocyanate, 1, 3-tetramethylxylene diisocyanate, and the like.

Examples of the alicyclic polyisocyanate include: 3-isocyanatomethyl-3, 5-trimethylcyclohexyl isocyanate, 1, 3-cyclopentane diisocyanate, 1, 3-cyclohexane diisocyanate, 1, 4-cyclohexane diisocyanate, methyl-2, 6-cyclohexane diisocyanate, 4' -methylenebis (cyclohexyl isocyanate), 1, 4-bis (isocyanatomethyl) cyclohexane, and the like.

The polyisocyanate is a diisocyanate, but triisocyanates in which the diisocyanate is modified may also be used. Examples of the triisocyanate include trimethylolpropane adducts, biuret (biuret) bodies, and trimers (the trimer including an isocyanurate ring) of the above-mentioned diisocyanates.

The polyisocyanate (b) is preferably 4,4' -diphenylmethane diisocyanate, hexamethylene diisocyanate, 3-isocyanatomethyl-3, 5-trimethylcyclohexyl isocyanate (isophorone diisocyanate), or the like.

The polyisocyanate (b) may be used alone or in combination of two or more.

< catalyst >

The catalyst is preferably a tertiary amine compound, an organometallic compound, or the like.

Examples of the tertiary amine compound include: triethylamine, triethylenediamine, and 1,8-Diazabicyclo [5.4.0] -undecene-7 (1, 8-Diazabicyclo [5.4.0] -undecene-7, DBU), and the like.

The organometallic compound is preferably a tin compound, a non-tin compound, or the like.

Examples of the tin-based compound include: dibutyltin dichloride, dibutyltin oxide, dibutyltin dibromide, dibutyltin dimaleate (dibutyl tin dimaleate), dibutyltin dilaurate (DBTDL), dibutyltin diacetate, dibutyltin sulfide, tributyltin oxide, tributyltin acetate, triethyltin acetate (triethyl acetate), tributyltin acetate (tributyl acetate), dioctyltin oxide, tributyltin chloride, tributyltin trichloroacetate, and tin 2-ethylhexanoate, and the like.

Examples of the non-tin compound include: titanium compounds such as dibutyltitanium dichloride, tetrabutyl titanate, and butoxytitanium trichloride; lead compounds such as lead oleate, lead 2-ethylhexoate, lead benzoate, and lead naphthenate; iron compounds such as iron 2-ethylhexanoate and iron acetylacetonate; cobalt compounds such as cobalt benzoate and cobalt 2-ethylhexanoate; zinc compounds such as zinc naphthenate and zinc 2-ethylhexanoate; zirconium compounds such as zirconium naphthenate. Of these, tin-based compounds are more preferable because of an increase in reaction rate and less coloring.

The catalyst may be used alone or in combination of two or more.

The catalyst is preferably used in an amount of 0.01 to 1.0 part by mass based on 100 parts by mass of the total of the polyisocyanate (b) and the polyol (a).

< solvent >

If necessary, one or more solvents can be used for producing the urethane polyol (a). Examples of the solvent include: ketone solvents such as acetone and methyl ethyl ketone; ester solvents such as ethyl acetate; hydrocarbon solvents such as toluene and xylene. Among these, ester solvents, hydrocarbon solvents, and the like are preferable in terms of solubility of the urethane polyol (a), boiling point of the solvent, and the like.

< method for producing urethane polyol (A) >

The method for producing the urethane polyol (a) is not particularly limited, and it can be produced by a known polymerization method such as a bulk polymerization method or a solution polymerization method.

The order of the production method includes, for example:

(sequence 1) a sequence in which one or more polyols (a), one or more polyisocyanates (b), optionally one or more catalysts, and optionally one or more solvents are charged into a flask together;

(sequence 2) A sequence in which one or more polyols (a), optionally one or more catalysts, and optionally one or more solvents are charged into a flask, and one or more polyisocyanates (b) are added dropwise thereto.

(sequence 3) A sequence in which the remaining part of the one or more polyols (a) after leaving the final dropwise addition part, optionally one or more catalysts, and optionally one or more solvents are charged into a flask, and one or more polyisocyanates (b) are dropwise added thereto, followed by dropwise addition of the remaining part of the one or more polyols (a).

Of these, it is preferable that the reaction heat be easily controlled (step 2) (step 3).

When a catalyst is used, the reaction temperature is preferably less than 100 ℃ and more preferably 70 to 95 ℃. When the reaction temperature is less than 100 ℃, the desired urethane polyol (a) can be easily obtained because side reactions other than the urethane reaction can be suppressed. In the case where no catalyst is used, the reaction temperature is preferably 100 ℃ or higher, more preferably 110 ℃ or higher.

The isocyanate group (NCO) of the polyisocyanate (b) and the hydroxyl group (OH) of the polyol (a) in producing the urethane polyol (a) are preferably 0.3 to 0.95, more preferably 0.4 to 0.90, and still more preferably 0.5 to 0.80 in terms of the molar ratio NCO/OH. When the NCO/OH ratio is within the above range, a urethane polyol (a) having an appropriate molecular chain can be formed, and thus wettability and productivity are further improved.

When a catalyst is used for the synthesis, the catalyst is preferably made inert. The reaction terminator may be, for example, acetylacetone.

The reaction terminator may be used alone or in combination of two or more.

The weight average molecular weight (Mw) of the urethane polyol (a) is preferably 100,000 to 500,000, more preferably 100,000 to 400,000, and still more preferably 150,000 to 400,000. By adjusting the weight average molecular weight (Mw) to the above range, the adhesive layer has a certain cohesive force immediately after winding, and therefore, the indentation can be suppressed and the yield can be improved.

< isocyanate curing agent (B) >

The isocyanate hardener (B) is a known compound having a plurality of isocyanate groups. The isocyanate hardener (B) is preferably the polyisocyanate (B), and more preferably aromatic polyisocyanate, aliphatic polyisocyanate, aromatic aliphatic polyisocyanate and alicyclic polyisocyanate, trimethylolpropane adducts thereof, biuret products thereof, and trifunctional isocyanate which is a trimer thereof.

The isocyanate hardener (B) may be used alone or in combination of two or more.

The amount of the isocyanate curing agent (B) blended is preferably 0.1 to 30 parts by mass, more preferably 1 to 25 parts by mass, even more preferably 3 to 20 parts by mass, and particularly preferably 5 to 15 parts by mass, based on 100 parts by mass of the urethane polyol (a). When an appropriate amount of the isocyanate curing agent (B) is blended, appropriate adhesive force and cohesive force can be easily obtained.

< plasticizer (C) >

The adhesive of the present embodiment may further include a plasticizer (C). By containing the plasticizer (C), the wettability of the adhesive layer with respect to the adherend is further improved. The plasticizer (C) is preferably a fatty acid ester or a phosphate ester having 8 to 30 carbon atoms from the viewpoint of compatibility with other components.

The total number of carbon atoms of the fatty acid ester having 8 to 30 carbon atoms is 8 to 30, and examples thereof include: esters of C6-18 monobasic or polybasic acids with branched alcohols having not more than 18 carbon atoms, esters of C14-18 unsaturated fatty acids or branched acids with tetravalent or less alcohols, esters of C6-18 monobasic or polybasic acids with polyalkylene glycols, fatty acid esters obtained by epoxidizing unsaturated sites with peroxides, and the like.

Examples of the ester of a C6-18 monobasic or polybasic acid and a C18 or less branched alcohol include: isostearyl laurate, isopropyl myristate, isocetyl myristate, octyldodecyl myristate, isostearyl palmitate, isocetyl stearate, octyldodecyl oleate, diisostearyl adipate, diisocetyl sebacate, trioleyl trimellitate, triisocetyl trimellitate, and the like.

The unsaturated fatty acid having 14 to 18 carbon atoms and the branched acid and the tetravalent or lower alcohol constituting the ester of the unsaturated fatty acid having 14 to 18 carbon atoms or the branched acid and the tetravalent or lower alcohol are as follows. Examples of the unsaturated fatty acid or branched acid having 14 to 18 carbon atoms include: myristoleic acid, oleic acid, linoleic acid, linolenic acid, isopalmitic acid, isostearic acid, etc. As tetravalent alcohols, mention may be made of: ethylene glycol, propylene glycol, glycerin, trimethylolpropane, pentaerythritol, sorbitan, and the like.

Examples of the ester of a monovalent or polyvalent acid having 6 to 18 carbon atoms and a polyalkylene glycol include: polyethylene glycol dihexyl acid, polyethylene glycol di-2-ethylhexyl acid, polyethylene glycol dilaurate, polyethylene glycol dioleate, and polyethylene glycol dimethyl adipate.

Examples of the fatty acid ester obtained by epoxidizing an unsaturated site with a peroxide or the like include epoxidized oils such as epoxidized soybean oil, epoxidized linseed oil and epoxidized cottonseed oil, compounds obtained by epoxidizing unsaturated fatty acids having 8 to 18 carbon atoms, ester compounds with linear alcohols or branched alcohols having 1 to 6 carbon atoms, and the like.

Examples of the phosphate ester include ester compounds of phosphorous acid or phosphoric acid and a linear or branched alcohol having 2 to 18 carbon atoms.

The plasticizer (C) may be used alone or in combination of two or more.

The plasticizer (C) preferably has a formula weight or number average molecular weight (Mn) of 300 to 1000, more preferably 300 to 900, and even more preferably 350 to 850, from the viewpoint of improvement in wetting rate and the like.

The amount of the plasticizer (C) to be blended is preferably 0.1 to 100 parts by mass, more preferably 1 to 80 parts by mass, and still more preferably 5 to 60 parts by mass, based on 100 parts by mass of the urethane polyol (a). When an appropriate amount of the plasticizer (C) is blended, the wettability is further improved.

< antioxidant (D) >

The adhesive of the present embodiment contains an antioxidant (D). When the antioxidant (D) is contained, thermal decomposition of the crosslinked network of the urethane polyol (a) and the isocyanate curing agent (B) can be suppressed, and thus an adhesive layer which is less likely to be deteriorated in removability after a lapse of time at a high temperature can be obtained.

Examples of the antioxidant (D) include a radical chain inhibitor such as a phenol-based antioxidant and an amine-based antioxidant, a sulfur-based antioxidant, and a phosphorus-based antioxidant. Of these, phenol antioxidants are preferable.

Examples of the phenolic antioxidant include: monophenol antioxidants such as 2, 6-di-tert-butyl-p-cresol, butylated hydroxyanisole, 2, 6-di-tert-butyl-4-ethylphenol, and stearyl β - (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate;

bisphenol-based antioxidants such as 2,2 '-methylenebis (4-methyl-6-tert-butylphenol), 2' -methylenebis (4-ethyl-6-tert-butylphenol), 4 '-thiobis (3-methyl-6-tert-butylphenol), 4' -butylidenebis (3-methyl-6-tert-butylphenol), and 3, 9-bis [1, 1-dimethyl-2- [ beta- (3-tert-butyl-4-hydroxy-5-methylphenyl) propionyloxy ] ethyl ]2,4,8, 10-tetraoxaspiro [5,5] undecane;

examples of the antioxidant include high molecular phenol antioxidants such as 1, 3-tris (2-methyl-4-hydroxy-5-t-butylphenyl) butane, 1,3, 5-trimethyl-2, 4, 6-tris (3, 5-di-t-butyl-4-hydroxybenzyl) benzene, tetrakis- [ methylene-3- (3 ',5' -di-t-butyl-4 ' -hydroxyphenyl) propionate ] methane, ethylene glycol bis [3,3' -bis- (4 ' -hydroxy-3 ' -t-butylphenyl) butyrate ], and 1,3, 5-tris (3 ',5' -di-t-butyl-4 ' -hydroxybenzyl) -s-triazine-2, 4,6- (1h, 3h, 5h) trione, and tocopherol.

Examples of the sulfur-based antioxidant include: dilauryl 3,3' -thiodipropionate, ditetradecyl 3,3' -thiodipropionate, distearyl 3,3' -thiodipropionate, and the like.

Examples of the phosphorus-containing antioxidant include: triphenyl phosphite, diphenylisodecyl phosphite, and phenyldiisodecyl phosphite, and the like.

The antioxidant (D) may be used singly or in combination of two or more.

The amount of the antioxidant (D) blended is preferably 0.1 to 10 parts by mass, more preferably 0.3 to 5 parts by mass, and still more preferably 0.5 to 3 parts by mass, based on 100 parts by mass of the urethane polyol (a).

< antistatic agent (E) >

The adhesive of the present embodiment contains an antistatic agent (E). If the antistatic agent (E) is contained, electrostatic discharge at the time of peeling the adhesive sheet is easily suppressed, and for example, breakage of parts and the like incorporated in a display and the like is easily prevented.

Examples of antistatic agents include: inorganic salts, ionic liquids, ionic solids, surfactants, and the like. Of these, ionic liquids are preferred. The "ionic liquid" is also referred to as an ambient temperature molten salt, and exhibits a liquid state at 25 ℃.

Examples of the inorganic salt include: sodium chloride, potassium chloride, lithium perchlorate, ammonium chloride, potassium chlorate, aluminum chloride, copper chloride, ferrous chloride, ferric chloride, ammonium sulfate, potassium nitrate, sodium carbonate, sodium thiocyanate, and the like.

The ionic liquid is a salt of a cation and an anion, and the cation is preferably an imidazolium ion, a pyridinium ion, an ammonium ion, or the like.

Examples of the ionic liquid containing an imidazolium ion include: 1-ethyl-3-methylimidazolium bis (trifluoromethylsulfonyl) imide, 1, 3-dimethylimidazolium bis (trifluoromethylsulfonyl) imide, and 1-butyl-3-methylimidazolium bis (trifluoromethylsulfonyl) imide, and the like.

Examples of the ionic liquid containing pyridinium ions include: 1-methylpyridinium bis (trifluoromethylsulfonyl) imide, 1-butylpyridinium bis (trifluoromethylsulfonyl) imide, 1-hexylpyridinium bis (trifluoromethylsulfonyl) imide, 1-octylpyridinium bis (trifluoromethylsulfonyl) imide, 1-hexyl-4-methylpyridinium hexafluorophosphate, 1-octyl-4-methylpyridinium bis (trifluoromethylsulfonyl) imide, 1-octyl-4-methylpyridinium bis (fluorosulfonyl) imide, 1-methylpyridinium bis (perfluoroethylsulfonyl) imide, 1-methylpyridinium bis (perfluorobutylsulfonyl) imide, and the like.

Examples of the ionic liquid containing ammonium ions include: trimethylheptylammonium bis (trifluoromethanesulfonyl) imide, N-diethyl-N-methyl-N-propylammonium bis (trifluoromethanesulfonyl) imide, N-diethyl-N-methyl-N-pentylammonium bis (trifluoromethanesulfonyl) imide, N-diethyl-N-methyl-N-heptylammonium bis (trifluoromethanesulfonyl) imide, tri-N-butylmethylammonium bis (trifluoromethanesulfonyl) imide, and the like.

In addition to these, known ionic liquids having a cation such as pyrrolidinium ion, phosphonium ion, sulfonium ion and the like can be suitably used.

The ionic solid is a salt of a cation and an anion, as in the case of the ionic liquid, but exhibits a solid state at 25 ℃ under normal pressure. The cation is preferably an alkali metal ion, phosphonium ion, pyridinium ion, ammonium ion, or the like.

Examples of the ionic solid containing an alkali metal ion include: lithium bis (fluorosulfonyl) imide, lithium bis (trifluoromethylsulfonyl) imide, lithium bis (pentafluoroethylsulfonyl) imide, lithium bis (heptafluoropropylsulfonyl) imide, lithium bis (nonafluorobutylsulfonyl) imide, sodium bis (fluorosulfonyl) imide, sodium bis (trifluoromethylsulfonyl) imide, sodium bis (pentafluoroethylsulfonyl) imide, sodium bis (heptafluoropropylsulfonyl) imide, sodium bis (nonafluorobutylsulfonyl) imide, potassium bis (fluorosulfonyl) imide, potassium bis (trifluoromethylsulfonyl) imide, potassium bis (pentafluoroethylsulfonyl) imide, potassium bis (heptafluoropropylsulfonyl) imide, potassium bis (nonafluorobutylsulfonyl) imide, and the like.

Examples of ionic solids containing phosphonium ions include: tetrabutylphosphonium difluorosulfonimide, tetrabutylphosphonium bistrifluoromethylsulfonimide, tetrabutylphosphonium dipentafluoroethylsulfonylimide, tetrabutylphosphonium bistheptafluoropropylsulfonimide, tetrabutylphosphonium bistrifluorobutylsulfonylimine, tributylhexadecylphosphonium difluorosulfonimide, tributylhexadecylphosphonium bistrifluoromethylsulfonimide, tributylhexadecylphosphonium dipentafluoroethylsulfonylimide, tributylhexadecylphosphonium bisteptafluoropropylsulfonylimine, tributylhexadecylphosphonium bistrifluorobutylsulfonylimine, tetraoctylphosphonium bistrifluoromethylsulfonimide, tetraoctylphosphonium dipentafluoroethylsulfonimide, tetraoctylphosphonium bistheptafluoropropylsulfonimide, tetraoctylphosphonium bistrifluorobutylsulfonylimine, etc.

Examples of the ionic solid containing a pyridinium ion include: 1-hexadecyl-4-methylpyridinium bis-fluorosulfonyl imide, 1-hexadecyl-4-methylpyridinium bis-trifluoromethylsulfonyl imide, 1-hexadecyl-4-methylpyridinium bis-pentafluoroethylsulfonyl imide, 1-hexadecyl-4-methylpyridinium bis-heptafluoropropylsulfonyl imide, 1-hexadecyl-4-methylpyridinium bis-nonafluorobutylsulfonyl imide, and the like.

Examples of the ionic solid containing ammonium ions include: tributylmethyl bis (trifluoromethyl) sulfonyl imide, tributylmethyl bis (pentafluoroethyl) sulfonyl imide, tributylmethyl bis (heptafluoropropyl) sulfonyl imide, tributylmethyl bis (nonafluorobutyl) sulfonyl imide, octyl tributyl bis (trifluoromethyl) sulfonyl imide, octyl tributyl bis (pentafluoroethyl) sulfonyl imide octyl tributyl bis heptafluoro propyl sulfonyl imide, octyl tributyl bis nonafluoro butyl sulfonyl imide, tetrabutyl bis fluoro sulfonyl imide, tetrabutyl bis trifluoromethyl sulfonyl imide, tetrabutyl bis pentafluoroethyl sulfonyl imide, tetrabutyl bis heptafluoro propyl sulfonyl imide, tetrabutyl bis nonafluoro butyl sulfonyl imide, and the like.

In addition to these, known ionic solids having a cation such as a pyrrolidinium ion, an imidazolium ion, and a sulfonium ion can be suitably used.

Surfactants can be classified as nonionic, anionic, cationic, and amphoteric types.

Examples of the nonionic surfactant include: glycerin fatty acid ester, polyoxyalkylene alkyl ether, polyoxyethylene alkylphenyl ether, polyoxyethylene alkylamine fatty acid ester, fatty acid diethanolamide, polyether ester amide type, ethylene oxide-epichlorohydrin type, polyether ester type, and the like.

Examples of the anionic surfactant (excluding ionic liquids and ionic solids) include: alkyl sulfonates, alkylbenzene sulfonates, alkyl phosphates, polystyrene sulfonic acid types, and the like.

Examples of the cationic surfactant include: tetraalkylammonium salts, trialkylbenzylammonium salts, and quaternary ammonium salt group-containing acrylate polymers.

Examples of the amphoteric surfactant include: and betaine-type amphoteric surfactants such as alkyl betaines, alkyl imidazolium betaines, higher alkyl aminopropionates and the like, higher alkyl dimethyl betaines, higher alkyl dihydroxyethyl betaines and the like.

The antistatic agent (E) is liquid or solid at 25 ℃.

The antistatic agent (E) which is liquid at 25 ℃ is more likely to be transferred to the interface between the pressure-sensitive adhesive layer and the adherend than a solid, and thus more excellent antistatic properties are more likely to be obtained.

In addition, the antistatic agent (E) which is solid at 25 ℃ is likely to partially exist in the adhesive layer in the form of islands of sea-island structure, as compared with a liquid. This improves the stress relaxation property of the pressure-sensitive adhesive layer, and thus makes it easy to obtain good adhesion to a substrate.

Of these, the antistatic agent (E) is preferably 1-octyl-4-methylpyridinium bis (fluorosulfonyl) imide or tetrabutylphosphonium bis (trifluoromethanesulfonylimide).

The antistatic agents (E) may be used singly or in combination of two or more.

The blending amount of the antistatic agent (E) is preferably 0.01 to 3 parts by mass, more preferably 0.03 to 2 parts by mass, and still more preferably 0.06 to 1 part by mass, based on 100 parts by mass of the urethane polyol (a). When an appropriate amount of the antistatic agent (E) is blended, the removability after the lapse of high temperature becomes less liable to decrease, and the yield in the production of the adhesive sheet is further improved.

< polyfunctional polyol (F) >

The polyfunctional polyol (F) of the present embodiment reacts with the urethane polyol (a) together with the isocyanate curing agent (B) to form a segment having a high crosslinking density in the crosslinked structure of the adhesive layer. Since the molecular weight of the segment having a high crosslinking density is low immediately before the reaction, the following effects are exhibited: the surface orientation is excellent, the surface of the coating film is firm, and the indentation is reduced. The polyfunctional polyol (F) can be used as the polyol (a) remaining in the synthesis of the urethane polyol (A) or can be reconstituted. Furthermore, it is also possible to use residual polyols (a) in combination with the novel formulations.

The polyfunctional polyol (F) can be used in the polyol (a) described above, and the number of hydroxyl groups in one molecule is 3 or more. By setting the number of hydroxyl groups in one molecule to 3 or more, the segment having a high crosslinking density can be appropriately adjusted on the surface of the adhesive layer, and therefore, the indentation is further reduced.

When the polyol having a primary hydroxyl group at the end is used as the polyfunctional polyol (F), the curing rate with the isocyanate curing agent (B) is improved, the indentation is suppressed, and the yield is easily further improved.

When the polyfunctional polyol (F) is a polyol having a secondary hydroxyl group at the molecular terminal, it takes time until the crosslinking is completed, and therefore an adhesive layer with less curing strain can be formed. Thus, the adhesive layer may be sufficiently closely adhered to a substrate which is not subjected to an easy adhesion treatment such as corona treatment.

The polyfunctional polyol (F) is preferably contained in an amount of 2 to 50 parts by mass, more preferably 2 to 30 parts by mass, and still more preferably 4 to 20 parts by mass, based on 100 parts by mass of the urethane polyol (a). By containing 2 to 50 parts by mass of the polyfunctional polyol (F), the proportion of the segment having a high crosslinking density can be appropriately adjusted on the surface of the adhesive layer, and therefore, the indentation can be further reduced.

As the polyfunctional polyol (F), those having 3 or more hydroxyl groups in one molecule and having a primary hydroxyl group or a secondary hydroxyl group at the molecular terminal in the polyol (a) listed above can be used. Particularly preferred are polyester polyols or polyether polyols.

The number average molecular weight (Mn) of the polyfunctional polyol (F) is preferably in the range of 500 to 6,000, more preferably 1,000 to 5,000, and still more preferably 1,000 to 4,000. When the amount is 500 or more, the formation of microgel which partially reacts with the isocyanate curing agent (B) can be suppressed, and when the amount is 6,000 or less, the molecular weight between crosslinks can be reduced, and therefore, indentation can be suppressed, and the removability after the lapse of time at high temperature can be further improved.

< solvent >

The solvent used in the production of the urethane polyol (a) may be a solvent, but an ester-based solvent, a hydrocarbon-based solvent, or the like is preferable. The solvents may be used singly or in combination of two or more.

< other additives >

The adhesive of the present embodiment may contain other additives as needed as long as the problem can be solved. Examples of other additives include: resins, fillers, metal powders, pigments, foils, softening agents, ultraviolet absorbers, light stabilizers, surface lubricants, leveling agents, corrosion inhibitors, heat stabilizers, polymerization inhibitors, antifoaming agents, lubricants, and the like.

Examples of the filler include: talc, calcium carbonate, titanium oxide, and the like.

Examples of the ultraviolet absorber include: benzophenone-based ultraviolet absorbers, benzotriazole-based ultraviolet absorbers, salicylic acid-based ultraviolet absorbers, oxanilide-based ultraviolet absorbers, cyanoacrylate-based ultraviolet absorbers, triazine-based ultraviolet absorbers, and the like.

Examples of the benzophenone-based ultraviolet absorber include; 2, 4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-octyloxybenzophenone, 2-hydroxy-4-dodecyloxybenzophenone, 2' -dihydroxy-4-dimethoxybenzophenone, 2' -dihydroxy-4, 4' -dimethoxybenzophenone, 2-hydroxy-4-methoxy-5-sulfobenzophenone, bis (2-methoxy-4-hydroxy-5-benzoylphenyl) methane and the like.

Examples of the benzotriazole-based ultraviolet absorber include: 2- (2 '-hydroxy-5' -methylphenyl) benzotriazole, 2- (2 '-hydroxy-5' -tert-butylphenyl) benzotriazole, 2- (2 '-hydroxy-3', 5 '-di-tert-butylphenyl) benzotriazole, 2- (2' -hydroxy-3 '-tert-butyl-5' -methylphenyl) -5-chlorobenzotriazole, 2- (2 '-hydroxy-3', 5 '-di-tert-butylphenyl), 5' -di-tert-amylphenyl) benzotriazole, 2- (2 '-hydroxy-4' -octyloxyphenyl) benzotriazole, 2- [2 '-hydroxy-3' - (3 ", 4", 5", 6" -tetrahydrophthalimidomethyl) -5 '-methylphenyl ] benzotriazole, 2' -methylenebis [4- (1, 3-tetramethylbutyl) -6- (2H-benzotriazol-2-yl) phenol ], and 2 (2 '-hydroxy-5' - (meth) acryloyloxyphenyl) -2H-benzotriazole, and the like.

Examples of the salicylic acid-based ultraviolet absorber include: phenyl salicylate, p-tert-butylphenyl salicylate, p-octylphenyl salicylate, and the like.

Examples of the cyanoacrylate-based ultraviolet absorber include: 2-ethylhexyl-2-cyano-3, 3 '-diphenylacrylate and ethyl-2-cyano-3, 3' -diphenylacrylate.

Examples of the light stabilizer include hindered amine light stabilizers and ultraviolet light stabilizers.

Examples of the hindered amine light stabilizer include: [ bis (2, 6-tetramethyl-4-piperidyl) sebacate ] bis (1, 2, 6-pentamethyl-4-piperidyl) sebacate, methyl 1,2, 6-pentamethyl-4-piperidyl sebacate and the like.

Examples of the ultraviolet stabilizer include: nickel bis (octylphenyl) sulfide, [2,2' -thiobis (4-tert-octylphenolate) ] -n-butylaminonickel, nickel complex-3, 5-di-tert-butyl-4-hydroxybenzyl-phosphoric acid monoethanol salt, nickel-dibutyldithiocarbamate, benzoate-type quencher, and nickel-dibutyldithiocarbamate, and the like.

Examples of the leveling agent include acrylic leveling agents, fluorine leveling agents, and silicon leveling agents. When a commercially available leveling agent is used, examples of the acrylic leveling agent include: perifolol (Polyflow) No.36, perifolol (Polyflow) No.56, perifolol (Polyflow) No.85HF, perifolol (Polyflow) No.99C (all manufactured by Kyoeisha chemical Co., ltd.), and the like. Examples of the fluorine-based leveling agent include Megafac (Megafac) F470N and Megafac (Megafac) F556 (both produced by DIC). Examples of the silicon leveling agent include Gelandi (grand) PC4100 (manufactured by DIC).

< adhesive sheet >

The adhesive sheet of the present embodiment includes a base material and an adhesive layer of a cured product as an adhesive. The adhesive layer may be formed on one or both sides of the substrate. Further, the surface of the adhesive layer not in contact with the substrate is usually protected with a release sheet immediately before use in order to prevent adhesion of foreign matter.

The substrate can be a flexible sheet or a plate without limitation. Examples of the substrate include: plastic, paper, and metal foil, and a substrate obtained by laminating these materials.

For the surface of the substrate in contact with the pressure-sensitive adhesive layer, for example, an easy adhesion treatment such as a dry treatment such as corona discharge treatment or a wet treatment such as anchor coating agent (anchor coating agent) coating may be performed in advance to improve the adhesion.

Examples of the plastic of the substrate include: ester resins such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN); olefin resins such as Polyethylene (PE), polypropylene (PP), and cycloolefin polymer (COP); vinyl resins such as polyvinyl chloride; amide resins such as nylon 66; urethane resins (including foams), and the like.

The thickness of the substrate is usually about 10 μm to 300. Mu.m. When a polyurethane sheet (including a foam) is used as the base material, the thickness is usually about 20 to 50,000 μm. Examples of the paper include plain paper, coated paper, and coated paper. Examples of the metal foil include aluminum foil and copper foil.

As the release sheet, a known release sheet obtained by applying a known release treatment such as a silicone release agent to the surface of plastic, paper, or the like can be used.

Examples of the method for producing the adhesive sheet include the following methods: the adhesive is applied to the surface of the base material to form a coating layer, and the coating layer is dried and cured to form an adhesive layer. The heating and drying temperature is usually about 60 ℃ to 150 ℃. The thickness of the adhesive layer is usually about 0.1 μm to 200. Mu.m.

Examples of the coating method include known methods such as a roll coater method, a comma coater method, a die coater method, a reverse coater method, a screen printing method, and a gravure coater method.

Further, the following methods can be exemplified: in contrast to the above method, a coating layer is formed by coating an adhesive on the surface of the release sheet, and then the coating layer is dried and cured to form an adhesive layer containing a cured product of the adhesive of the present embodiment, and finally, a substrate is bonded to the exposed surface of the adhesive layer. When the release sheet is attached by the above method in place of the substrate, a cast adhesive sheet of release sheet/adhesive layer/release sheet can be obtained.

< layered product >

The laminate of the present embodiment includes a member selected from the group consisting of a transparent conductive film, glass, an acrylic plate, a polycarbonate plate, an olefin plate, and an inorganic barrier layer, and an adhesive sheet.

Since the laminate includes the adhesive sheet formed of the adhesive of the present embodiment, for example, when a display is manufactured, a member of the display which is easily broken can be protected, and peeling can be easily performed after the manufacturing. The display is, for example, an LCD, an OLED, or the like, and as other components, a touch panel is often included.

The touch panel includes, for example, a transparent electrode film. The transparent electrode film is formed by, for example, forming a conductive layer of ITO (indium tin oxide) or the like on the surface of a transparent film of polyethylene terephthalate (PET) or the like by sputtering or vapor deposition to a thickness of about 0.1 μm to 0.3 μm. A conductive layer (electrode layer) formed using ITO or the like is easily broken. Therefore, if the adhesive layer is included, the conductive layer is less likely to be damaged during handling, processing, and the like.

In order to protect the vulnerable light emitting elements, the OLED includes an inorganic blocking layer. The inorganic barrier layer is formed by, for example, vapor deposition or sputtering of an inorganic compound such as silicon nitride to a thickness of about 15nm to 100 nm. Therefore, if the adhesive sheet is included, the inorganic barrier layer is less likely to be damaged during handling, processing, and the like of the OLED.

Glass, acrylic sheets, polycarbonate sheets, and olefin sheets are optical members constituting a part of a laminate constituting a display such as an LCD and an OLED. The optical member is used, for example, for protecting a liquid crystal element, or for the outermost surface of a touch panel, or the like. Since the touch panel is required to be thin, the optical member is also thin and is easily broken. Therefore, if the adhesive sheet is included, the optical member is less likely to be damaged during operations such as conveyance and processing of the touch panel. The optical member may have an optical function such as a hard coat layer, a retardation layer, and a polarizing plate. The thickness of the optical member is about 10 μm to 1000 μm.

[ examples ]

Hereinafter, embodiments of the present invention will be described with reference to examples. It is needless to say that the embodiments of the present invention are not limited to the examples. Hereinafter, "part" means "part by mass". In addition, "%" means "% by mass". The blending amounts in the table are parts by mass.

[ Synthesis example of urethane polyol (A) ]

(Synthesis example 1)

Into a four-necked flask equipped with a stirrer, a reflux condenser, a nitrogen inlet, a thermometer and a dropping funnel were charged 500 parts of a Polyol (Kuraray Polyol) P-1010 (a bifunctional polyester Polyol, manufactured by the company "Kuraray"), 500 parts of a Polyol (Kuraray Polyol) F-1010 (a trifunctional polyester Polyol, manufactured by the company "Kuraray"), 140 parts of hexamethylene diisocyanate, 760 parts of toluene and 0.05 part of dioctyltin dilaurate as a catalyst, and the temperature was gradually raised to 75 ℃ to carry out a reaction for 3 hours. NCO characteristic absorption (2,270cm) in the Infrared Spectrum (IR) chart was confirmed ^-1 ) After disappearance, the reaction mixture was cooled to 30 ℃ to terminate the reaction. The urethane polyol (A1) has a weight-average molecular weight (Mw) of 150,000 and a conversion of more than 99%.

(Synthesis examples 2 to 36, 38 and 39)

Urethane polyols (a) of synthesis examples 2 to 36, 38 and 39 were obtained in the same manner as in synthesis example 1, except that the materials and formulation ratios of example 1 were changed to those shown in tables 1 to 4. The Mw and conversion of the obtained urethane polyol (a) are shown in table 1. The amounts of the raw materials in the tables are calculated as nonvolatile components, and the units of numerical values not specifically described are "parts".

(Synthesis example 37)

Into a four-necked flask equipped with a stirrer, a reflux condenser, a nitrogen inlet, a thermometer and a dropping funnel were charged 200 parts of a Polyol (Kuraray Polyol) P-1010 (a bifunctional polyester Polyol, manufactured by Kuraray corporation), 550 parts of an exocanol (exocanol) 240 (a trifunctional polyether Polyol, manufactured by asahi glass corporation), 170 parts of hexamethylene diisocyanate, 547 parts of toluene and 0.05 part of dioctyltin dilaurate as a catalyst, and the temperature was gradually raised to 90 ℃ to carry out a reaction for 30 minutes. Then, a mixed solution of 100 parts of a Polyol (Kuraray Polyol) P-1010, 150 parts of an icacinol (Excenol) and 167 parts of toluene was added dropwise from the dropping funnel over 30 minutes. NCO characteristic absorption (2,270cm) in the IR chart was confirmed ^-1 ) After disappearing, coolThe reaction was terminated at 30 ℃. The urethane polyol (a 37) has Mw of 210,000 and conversion of over 90%.

[ Material ]

The materials used in the tables are as follows.

< polyol (a) >

(a1) The method comprises the following steps P1010 ("Korea Polyol) P-1010", polyester Polyol, mn1000, hydroxyl number 2, primary hydroxyl group, manufactured by Korea (Kuraray) Co., ltd.)

(a2) The method comprises the following steps P3199 ("prirast 3199", polyester polyol, mn2000, hydroxyl number 2, primary hydroxyl group, manufactured by Heda (CRODA))

(a3) The method comprises the following steps PP1000 ("Sunik (Sannix) PP-1000", polyoxypropylene glycol, mn1000, hydroxyl number 2, secondary hydroxyl, available from Sanyo chemical industries Co., ltd.)

(a4) The method comprises the following steps PP2000 ("Sunik (Sannix) PP-2000", polyoxypropylene glycol, mn2000, hydroxyl number 2, secondary hydroxyl, available from Sanyo chemical industries Co., ltd.)

(a5) The method comprises the following steps Excex 510 (Exceol 510;, polyether polyol, mn4000, hydroxyl number 2, primary hydroxyl, manufactured by Asahi glass company)

(a6) The method comprises the following steps GI1000 ("Nisso (NISSO) -PB GI-1000", hydrogenated polybutadiene with hydroxyl groups at both ends, mn1500, hydroxyl number 2, primary hydroxyl group, manufactured by Nippon Caoda corporation)

(a7) The method comprises the following steps GI3000 ("Nisso (NISSO) -PB GI-3000", hydrogenated polybutadiene having hydroxyl groups at both ends, mn3100, hydroxyl number 2, primary hydroxyl group, manufactured by Nicoyota Co., ltd.)

(a8) The method comprises the following steps HLBH P2000 ("Karsol (registered trademark) HLBH P2000", hydroxyl-terminated modified liquid polybutadiene, mn2000, hydroxyl number 1.95, primary hydroxyl group, manufactured by Kliviley (CRYVALLEY) Inc.)

(a9) The method comprises the following steps F1010 ("Kuraray Polyol F-1010", polyester Polyol, mn1000, hydroxyl number 3, primary hydroxyl group, manufactured by Kuraray Co., ltd.)

(a10) The method comprises the following steps F3010 ("Kuraray Polyol F-3010", polyester Polyol, mn3000, hydroxyl number 3, primary hydroxyl group, manufactured by Kuraray Co., ltd.)

(a11) The method comprises the following steps Aiksciri (Exce) 1030 (Excenol 1030;, polyether polyol, mn1000, hydroxyl number 3, secondary hydroxyl, manufactured by Asahi glass company)

(a12) The method comprises the following steps Excex 240 (Exceol 240;, polyether polyol, mn3000, hydroxyl number 3, primary hydroxyl group, available from Asahi glass Co., ltd.)

(a13) The method comprises the following steps Excise 4030 ("Excenol 4030", polyether polyol, mn4000, hydroxyl number 3, secondary hydroxyl group, manufactured by Asahi glass company)

(a14) The method comprises the following steps Aiksril (Exce) 828 (Excenol 828;, polyether polyol, mn5000, hydroxyl number 3, primary hydroxyl, manufactured by Asahi glass company)

(a15) The method comprises the following steps P3010 ("Kuraray Polyol) P-3010", polyester Polyol, mn1000, hydroxyl number 3, primary hydroxyl group, manufactured by Kuraray Co., ltd.)

(a16) The method comprises the following steps GP3000 ("Sunik (Sannix) GP-3000", polyether polyol, mn3000, hydroxyl number 3, secondary hydroxyl, made by Sanyo chemical industries Co., ltd.)

(a17) The method comprises the following steps AM302 ("Adeka polyether AM-302", polyether polyol, mn3000, hydroxyl number 3, primary hydroxyl group, made by Adeka corporation)

(a18) The method comprises the following steps PTMG1000 ("PTMG 1000", polytetramethylene ether glycol, mn1000, hydroxyl number 2, primary hydroxyl group, manufactured by Mitsubishi chemical corporation)

(a19) The method comprises the following steps S3011 ("Preminol S-3011", polyether polyol, mn10000, hydroxyl number 3, secondary hydroxyl group, manufactured by Asahi glass Co., ltd.)

(a20) The method comprises the following steps GP1000 ("Sunik (Sannix) GP-1000", polyether polyol, mn1000, hydroxyl number 3, secondary hydroxyl, available from Sanyo chemical industries Co., ltd.)

< polyisocyanate (b) >

(b1) The method comprises the following steps HDI ("Desmodur) H", manufactured by Sumika Covestro Urethane, inc.),

(b2) The method comprises the following steps TDI (toluene diisocyanate, "Desmodur (Desmodur) T-80" available from Sumika Covestro Urethane, inc.),

< isocyanate curing agent (B) >

(B1) The method comprises the following steps HDI adduct ("Sumidur HT"), trimethylolpropane adduct of hexamethylene diisocyanate, sumika Covestro Urethane (Sumika Covestro Urethane)

(B2) The method comprises the following steps HDI urate (nurate) ("Sumitour N3300", a urate ester of hexamethylene diisocyanate, sumika Covestro Urethane)

< plasticizer (C) >

(C1) The method comprises the following steps M182A ("friend letter M182A", methyl oleate, manufactured by Nichiol Co., ltd.)

(C2) The method comprises the following steps W262 ("Mosaize (Monocizer) W262", manufactured by DIC Inc., ether ester plasticizer)

(C3) The method comprises the following steps D55 ("Adecassizer (ADEKACIZER) D-55", epoxidized fatty acid alkyl ester, manufactured by Adeca (ADEKA) Co., ltd.)

(C4) The method comprises the following steps TOP ("TOP", tris (2-ethylhexyl) phosphate manufactured by Dai eight Industrial chemical Co., ltd.)

(C5) The method comprises the following steps IPP (Exceparl IPP), isopropyl palmitate, king flower)

< antioxidant (D) >

(D1) The method comprises the following steps Irg1010 ("Irganox 1010", pentaerythritol tetrakis [3- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate ], phenol antioxidant, manufactured by BASF corporation)

(D2) The method comprises the following steps IrgL135 ("Irganox L135", phenylpropionic acid 3, 5-bis (1, 1-dimethyl-ethyl) -4-hydroxy-, C7-C9 side chain alkyl ester, phenolic antioxidant, manufactured by BASF corporation)

< antistatic agent (E) >

(E1) The method comprises the following steps TFSI ammonium salt (tri-n-butyl methyl ammonium bis (trifluoromethane) sulfonyl imide, ionic liquid)

(E2) The method comprises the following steps TFSI lithium salt (lithium bis (trifluoromethane) sulfonyl imide, ionic solid)

(E3) The method comprises the following steps FSI pyridinium salt (1-octyl-4-methylpyridinium-bis (fluorosulfonyl) imide, ionic liquid)

(E4) The method comprises the following steps FSI imidazolium salt (1-ethyl-3-methyl-imidazolium-bis-fluorosulfonylimide, ionic liquid)

(E5) The method comprises the following steps TFSI phosphonium salts (tetrabutylphosphonium bistrifluoromethanesulfonylimide, ionic solids)

< polyfunctional polyol (F) >

The above-mentioned (a 9) to (a 20) are also used as the polyfunctional polyols, respectively.

[ measurement of weight-average molecular weight (Mw) and number-average molecular weight (Mn) ]

The weight average molecular weight (Mw) and the number average molecular weight (Mn) were measured by a Gel Permeation Chromatography (GPC) method. The measurement conditions are as follows. Furthermore, mw and Mn are both polystyrene equivalent values.

< measurement conditions >

The device comprises the following steps: shimadzu excellence (Shimadzu corporation),

Pipe column: three Soidex LF-804 (Shorex) were connected in series,

A detector: differential refractive index detector

Solvent: tetrahydrofuran (THF)

Flow rate: 0.5mL/min

Temperature of the solvent: 40 deg.C

Sample concentration: 0.1 percent

Sample injection amount: 100 μ L

(example 1)

100 parts of the urethane polyol (A1), 2 parts of the isocyanate curing agent (B1), 30 parts of the plasticizer (C1), 0.7 part of the antioxidant (D1), 0.1 part of the antistatic agent (E1), 10 parts of the polyfunctional polyol (F4 = a 12), and 100 parts of ethyl acetate as a solvent were mixed and stirred by a disperser to obtain an adhesive. The amounts of the respective materials except the solvent used are expressed as nonvolatile components [ parts ].

A polyethylene terephthalate (PET) having a thickness of 50 μm ("Lumiler T-60", manufactured by Toray corporation) was prepared as a substrate. The obtained adhesive was applied to the substrate at a coating speed of 3m/min and a width of 30cm using a comma coater (registered trademark) so that the thickness after drying became 12 μm, thereby forming a coating layer.

Next, the coating layer thus formed was dried at 100 ℃ for 1 minute using a drying oven to form an adhesive layer. A commercially available release sheet having a thickness of 38 μm was bonded to the pressure-sensitive adhesive layer, and curing was further carried out for 1 week under the conditions of 23-50% RH.

(example 2 to example 73, comparative example 1 to comparative example 5)

Adhesives and adhesive sheets of examples 2 to 73 and comparative examples 1 to 5 were obtained in the same manner as in example 1, except that the materials and formulation ratios of example 1 were changed to those shown in tables 5 to 13.

[ evaluation items and evaluation methods ]

Evaluation items and evaluation methods of the obtained adhesive and adhesive sheet are as follows.

(indentation)

An adhesive sheet was produced in the same manner as in example 1, except that the coating speed in example 1 was changed to 30m/min and the width was changed to 150cm, and the adhesive sheet was wound at regular intervals to visually evaluate the trace (indentation) of the tape connecting the roll and the adhesive sheet. The evaluation criteria are as follows.

Excellent: no tape trace was confirmed at the 10m site. Is excellent.

O: no tape trace was confirmed at the 25m spot. Is good.

And (delta): no tape trace was confirmed at the 50m spot. It is practical.

X: a tape trace was confirmed at a 50m spot. It is not practical.

(removability after lapse of time at high temperature)

The resulting adhesive sheet was prepared in a width of 25mm and a length of 100mm, and used as a measurement sample. Subsequently, the peel-off sheet was peeled off from the measurement sample in an environment of 23 to 50% rh, and the exposed adhesive layer was adhered to a caustic soda glass plate, and a 2kg roller was reciprocated once and pressure-bonded. Then, the mixture was left at 100 ℃ for 24 hours. Then, after air-cooling for 30 minutes in an environment of 23 to 50% RH, the adhesion was measured under conditions of a peeling speed of 300mm/min and a peeling angle of 180 ℃ using a tensile tester (Tencilon, manufactured by Orientec corporation) in accordance with Japanese Industrial Standards (JIS) Z0237. The measurement of the adhesive force was carried out in the same manner as described above except that the adherend was changed to an ITO film ("teterlight TCF", manufactured by kokushi industries), or a PET ("lumirar T-60", manufactured by dongli).

The evaluation criteria are as follows.

Very good: less than 100mN/25mm. Is excellent.

O: 100mN/25mm or more and less than 200mN/25mm. Is good.

And (delta): 200mN/25mm or more and 300mN/25mm or less. It is practical.

X: more than 300mN/25mm. It is not practical.

(staining by adherend)

The ITO surface after the "removability after a lapse of time at a high temperature" was evaluated for the staining property due to the adhesive.

The evaluation was carried out by irradiating the adherend with an LED lamp in a dark room under visual observation. The evaluation criteria are as follows.

O: contamination was not confirmed at all. Is good.

And (delta): a small amount of blurring was confirmed. It is practical.

X: a clear blur was confirmed. It is not practical.

(substrate adhesion)

The adhesive sheet thus obtained was prepared in a size of 50mm in width and 50mm in length and used as a measurement sample. Subsequently, the release sheet was peeled from the test sample in an environment of 23 to 50% rh, and 11 cracks were cut at intervals of 2mm in the adhesive layer by a cutter to a depth reaching the base material but not cut. Then, 11 slits were cut in the direction perpendicular to the slits in the same manner as described above, thereby forming 100 meshes in a grid shape. When the adhesive layer was strongly scratched 10 times from above with a finger, the number of the grids remaining without the adhesive layer being peeled off from the substrate was evaluated. The evaluation criteria are as follows.

Very good: 100 pieces remained. Is excellent.

O: more than 90 blocks and less than 100 blocks remain. Is good.

And (delta): more than 75 and less than 90 blocks remained. It is practical.

X: the remaining blocks were less than 75. It is not practical.

(antistatic Property)

The obtained adhesive sheet was prepared in a size of 50mm in width and 50mm in length and used as a measurement sample. Subsequently, the release sheet was peeled from the test sample in an environment of 23 to 50% RH, and the surface resistance value was evaluated by bringing the probe of a surface resistance value measuring instrument (Halaston (Hiresta) -UX MCP-HT800, manufactured by Mitsubishi Chemical analysis technology, inc.) into contact with the adhesive layer. The evaluation criteria are as follows.

Very good: the surface resistance value is less than 1 x 10 to the power of 8. Is excellent.

O: the surface resistance value is more than 8 times of 1 x 10 and less than 9 times of 1 x 10. Is good.

And (delta): the surface resistance value is more than 9 times of 1 x 10 and less than 10 times of 1 x 10. It is practical.

X: the surface resistance value is more than 10 times of 1 multiplied by 10. It is not practical.

[ Table 12]

[ Table 13]

Claims (10)

1. An adhesive, comprising:

urethane polyol (A) having a weight average molecular weight of 10 to 50 ten thousand as a reactant of polyol (a) and polyisocyanate (b),

An isocyanate hardener (B),

An antioxidant (D),

Antistatic agents (E) and

a polyfunctional polyol (F),

0.5 to 10 parts by mass of the antioxidant (D) per 100 parts by mass of the urethane polyol (A),

the polyfunctional polyol (F) has a secondary hydroxyl group at the terminal, has a number average molecular weight of 500 to 6,000, and has 3 or more hydroxyl groups per molecule.

2. Adhesive according to claim 1, further comprising a plasticizer (C).

3. The adhesive according to claim 2, wherein the plasticizer (C) is contained in an amount of 0.1 to 100 parts by mass based on 100 parts by mass of the urethane polyol (a).

4. The adhesive according to claim 1 or 2, wherein the polyfunctional polyol (F) is contained in an amount of 2 to 50 parts by mass per 100 parts by mass of the urethane polyol (a).

5. The adhesive according to claim 1 or 2, wherein the isocyanate hardener (B) is contained in an amount of 0.1 to 30 parts by mass based on 100 parts by mass of the urethane polyol (a).

6. The adhesive according to claim 1 or 2, wherein the antistatic agent (E) is contained in an amount of 0.01 to 3 parts by mass per 100 parts by mass of the urethane polyol (A).

7. Adhesive according to claim 1 or 2, characterized in that the antistatic agent (E) is liquid or solid at 25 ℃.

8. Adhesive according to claim 1 or 2, characterized in that the multifunctional polyol (F) comprises the same compound as the polyol (a).

9. An adhesive sheet, comprising:

base material, and

an adhesive layer which is a cured product of the adhesive according to any one of claims 1 to 8.

10. A laminate, comprising:

a member selected from the group consisting of a transparent conductive film, glass, an acrylic plate, a polycarbonate plate, an olefin plate, and an inorganic barrier layer; and

an adhesive sheet according to claim 9.