JP2009155464A - Active energy ray curable hotmelt adhesive composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an active energy ray curable hotmelt adhesive composition having low temperature dependency and peeling speed dependency of peeling strength and low curing volume contraction. <P>SOLUTION: The active energy ray curable hotmelt adhesive composition includes: a thermoplastic polyurethane resin (A) having one or more active energy ray polymerizable groups (e) in its molecule and a number average molecular weight of 2,500 to 100,000; a thermoplastic polyurethane resin (B) having one or more active energy ray polymerizable groups (e) in its molecule, an alkylene oxide added bisphenol compound in its molecule and a number average molecular weight of 600 to 1,800; and an active energy ray polymerization initiator (C). <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an adhesive that is cured by irradiation with active energy rays. More specifically, the present invention relates to an active energy ray-curable hot-melt pressure-sensitive adhesive composition having a small peel strength dependency on temperature and peel rate and a small cure volume shrinkage.

In recent years, adhesives using organic solvents have problems such as toxicity to workers, fire hazard, environmental pollution, drying speed, and waste of solvent. An acrylic resin-based pressure-sensitive adhesive (see, for example, Patent Document 2) that does not contain an organic solvent as an essential component and uses a curing reaction by ultraviolet (UV) irradiation has been studied.
JP-A-5-302071 JP 7-278500 A

However, the hot-melt pressure-sensitive adhesive has an essential problem that it usually lacks the heat-resistant holding property because it needs to be kept in a molten state when it is heated and applied. In addition, it is difficult to completely remove the acrylic monomer remaining in the acrylic resin with an acrylic resin adhesive that uses a curing reaction by UV irradiation, and a strong irritating odor caused by the residual monomer is generated from the adhesive of the final product. There is a problem of doing. Furthermore, since the molecular weight of the acrylic resin as the main component is relatively small, the adhesive holding power is weak, the temperature dependence and the peeling speed dependence of the peel strength are large, and the volume shrinkage at the time of curing is large, so the range of use is limited. is there.
An object of the present invention is to provide an active energy ray-curable hot-melt pressure-sensitive adhesive composition that solves the above problems.

  The inventors of the present invention have arrived at the present invention as a result of intensive studies to solve the above problems. That is, the present invention relates to a thermoplastic polyurethane resin (A) having one or more active energy ray polymerizable groups (e) in the molecule and having a number average molecular weight of 2,500 to 100,000, an active energy ray polymerizable group ( a thermoplastic polyurethane resin (B) having a number average molecular weight of 600 to 1,800 and an active energy ray polymerization initiator (C) having at least one e) in the molecule and an alkylene oxide adduct of a bisphenol compound in the molecule. Is an active energy ray-curable hot-melt pressure-sensitive adhesive composition.

The pressure-sensitive adhesive obtained by curing the active energy ray-curable hot melt pressure-sensitive adhesive composition of the present invention has the following effects.
(1) Temperature dependence of peel strength is small.
(2) Peeling speed dependence of peel strength is small.
(3) Volume shrinkage during curing is small.

[Thermoplastic polyurethane resin (A)]
The thermoplastic polyurethane resin (A) in the present invention has one or more (preferably 2 to 12) active energy ray polymerizable groups (e) in the molecule. Here, the content (number) of (e) in the molecule is a number average molecular weight [hereinafter abbreviated as Mn] by gel permeation chromatography (GPC) method described later. ] And the nuclear magnetic resonance spectrum.
(A) is formed from an active hydrogen-containing compound (a) and an isocyanate compound (b), and the active energy ray polymerizable group (e) is derived from (a) and / or (b).
(E) includes an active energy ray cationic polymerizable group (e1) (propenyl ether group, vinyl ether group, glycidyl group, etc.) and an active energy ray radical polymerizable group (e2) [(meth) acryloyl group, propenyl ether group, Vinyl ether group, allyl ether group, etc.].

(A) includes an active hydrogen-containing compound (a1) having one or more (preferably 2 to 6) (e) in the molecule, wherein (a1) includes mono- and polyols having a hydroxyl group. (A11), ketimine (a12) having a ketimine group and monoamine (a13) having a primary or secondary amino group are included.
In addition, (b) includes an isocyanate compound (b1) having one or more (preferably 2 to 6) (e) in the molecule.

  (A11), (a12) and (a13) each further contain an active energy ray cationically polymerizable group (e1) [(a11-1), (a12-1) and (a13-1)] And those containing an active energy ray radical polymerizable group (e2) [(a11-2), (a12-2) and (a13-2)].

The mono- and polyol (a11-1) having an active energy ray cationically polymerizable group (e1) and an active hydrogen-containing group have 3 or more carbon atoms (hereinafter abbreviated as C) and Mn (measurement conditions are as described below). 3,000 or less, for example, mono- and diols having propenyl ether groups [2-hydroxyethyl-, 2-hydroxypropyl- and 2,3-dihydroxypropylpropenyl ethers, etc.]; mono- and diols having vinyl ether groups [2 -Hydroxyethyl-, 2-hydroxypropyl-, 2,3-dihydroxypropyl vinyl ether, etc.]; mono- and diols having a glycidyl group [glycidol, ethylene glycol (hereinafter abbreviated as EG) monoglycidyl ether, glycerin (hereinafter abbreviated as GR) ) Monoglycidyle These alkylene oxides (hereinafter abbreviated as AO) [ethylene oxide (hereinafter abbreviated as EO), propylene oxide (hereinafter abbreviated as PO), 1,2-, 1,3- and 2,3-butylene oxide ( And the like (hereinafter abbreviated as BO), tetrahydrofuran (hereinafter abbreviated as THF), styrene oxide, and a combination of two or more thereof] adduct (Mn 5,000 or less).
Of these, from the viewpoint of curability, mono- and diols having a propenyl ether group are preferable, and 2-hydroxyethyl propenyl ether, 2,3-dihydroxypropyl propenyl ether, and their EO and / or PO adducts are more preferable. It is.

The measurement conditions of Mn in the present invention are as follows.
Apparatus: Gel permeation chromatography solvent: Tetrahydrofuran (hereinafter abbreviated as THF)
Reference substance: Polyethylene glycol (hereinafter abbreviated as PEG)
Sample concentration: 0.25 wt / vol%
Column temperature: 23 ° C
Column type: Cross-linked styrene fine particle gel [trade names “Super H4000”, “Super H3000”, and “Super H2000”, all manufactured by Tosoh Corporation. Use these in series. ]

  Examples of ketimine (a12-1) having an active energy ray cationically polymerizable group (e1) and an active hydrogen-containing group include dialkylene (alkylene group C is 2 to 6) triamine derivative ketimine, for example, (e1) Glycidyl compound [C3-18, for example, propenyl glycidyl ether, vinyl glycidyl ether], dialkylene (C is 2-6 of alkylene group) triamine (diethylenetriamine, dipropylenetriamine, dibutylenetriamine, etc.) and ketone (C3-18) And an equimolar addition reaction product with diketimine formed from, for example, acetone, methyl ethyl ketone, methyl isobutyl ketone). Among these, from the viewpoint of curability, an equimolar addition reaction product of propenyl glycidyl ether and diethylene triamine diacetimine is preferable.

  Examples of the monoamine (a13-1) having an active energy ray cationically polymerizable group (e1) and an active hydrogen-containing group include primary monoamines [monoalkylamines (C1-8, such as methylamine, ethylamine, n-butylamine, Octylamine), monoalkanolamines (C2-18, such as monoethanolamine, monoisopropanolamine) and the like, and glycidyl compounds having (e1) (C3-18, such as propenyl glycidyl ether, vinyl glycidyl ether), etc. Mole addition reactants may be mentioned. Among these, an equimolar addition reaction product of n-butylamine and propenyl glycidyl ether is preferable from the viewpoint of curability.

  Examples of the mono- and polyol (a11-2) having an active energy ray radical polymerizable group (e2) and an active hydrogen-containing group include mono- and diols having a (meth) acryloyl group [C4-18, for example, 2- Hydroxyethyl-, 2-hydroxypropyl- and 2,3-dihydroxypropyl (meth) acrylate]; mono- and diols having an allyl group [C3-6, such as 2-hydroxyethyl-, 2-hydroxypropyl- and 2, 3-dihydroxypropyl allyl ether]; mono- and diols having propenyl group or vinyl group exemplified as the above (a1-11); these AO [EO, PO, BO, THF, styrene oxide and two or more kinds thereof Combined use] adduct (Mn 5,000 or less) . Of these, from the viewpoint of curability, mono- and diols having a (meth) acryloyl group are preferred, and 2-hydroxyethyl-, 2-hydroxypropyl- and 2,3-dihydroxypropyl (meth) acrylates are more preferred. And their EO and / or PO adducts.

  Examples of the ketimine (a12-2) having an active energy ray radical polymerizable group (e2) and an active hydrogen-containing group include glycidyl compounds having the (e2) [C4-18, such as glycidyl (meth) acrylate, propenyl glycidyl Ethers, vinyl glycidyl ethers, allyl glycidyl ethers] and dialkylene (C 2-6 alkylene groups) triamines (diethylenetriamine, dipropylenetriamine, dibutylenetriamine, etc.) and ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.) An equimolar addition reaction product with the diketimine formed is mentioned. Among these, from the viewpoint of curability, an equimolar addition reaction product of glycidyl (meth) acrylate and diethylenetriamine diacetimine is preferable.

  Examples of the monoamine (a13-2) having an active energy ray radical polymerizable group (e2) and an active hydrogen-containing group include primary monoamines [monoalkylamines (C1-8, such as methylamine, ethylamine, n-butylamine, Octylamine), monoalkanolamines (C1-18, such as monoethanolamine, monoisopropanolamine)] and glycidyl compounds [C4-18, such as glycidyl (meth) acrylate, propenyl glycidyl ether, vinyl glycidyl ether] Ether, allyl glycidyl ether] and an equimolar addition reaction product. Among these, an equimolar addition reaction product of n-butylamine and glycidyl (meth) acrylate is preferable from the viewpoint of curability.

  Examples of the active hydrogen-containing compound (a) constituting (A) other than the above (a1) include the polymer polyol (a2), the low-molecular active hydrogen-containing compound (a3), and a combination thereof.

The polymer polyol (a2) is a polyol having an OH equivalent of 250 or more. As (a2), a polyether polyol, a polyester polyol, a polyether ester polyol, a polycarbonate polyol, a polymer polyol, a polyolefin polyol, a polyalkadiene polyol, Acrylic polyols and mixtures of two or more of these include.
Mn in (a2) is preferably 1,000 to 99,000, more preferably 1,500 to 80,000, from the viewpoints of adhesive strength and melt viscosity.

  Examples of polyether polyols include AO adducts of compounds having two active hydrogens (C2-18, for example, dihydric alcohols, dihydric phenols), and mixtures of two or more thereof.

Examples of the dihydric alcohol include EG, diethylene glycol, propylene glycol, 1,3- and 1,4-butanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, neopentyl glycol (hereinafter referred to as DEG, Alkylene glycols such as PG, BD, MPD, HD, and NPG; dihydric alcohols having a cyclic group [for example, those described in JP-B No. 45-1474: 1,4-bis (hydroxymethyl) cyclohexane , M- and p-xylylene glycol, etc.].
As the dihydric phenol, monocyclic polyhydric phenol (C6-18, such as pyrogallol, hydroquinone, phloroglucin); polycyclic polyhydric phenol (C12-30, such as dihydroxynaphthalene) bisphenol compound (C12-30, such as bisphenol A, -S) And -F). Of the compounds having two active hydrogens, a dihydric alcohol is preferred from the viewpoint of the flexibility of the pressure-sensitive adhesive.

  Examples of AO include EO, PO, BO, THF, styrene oxide, and combinations of two or more of these (block and / or random addition). Among these, PO, EO, BO, and combinations thereof are preferable from the viewpoint of the flexibility of the pressure-sensitive adhesive.

  Examples of the polyester polyol include (1) a condensation polyester polyol obtained by condensation polymerization of one or more of the dihydric alcohol and one or more of a polycarboxylic acid or an ester-forming derivative thereof; (2) starting the dihydric alcohol. And a polylactone polyol obtained by ring-opening polymerization of a lactone used as an agent; and a mixture of two or more of these.

  Examples of the polycarboxylic acid (1) include aliphatic dicarboxylic acids (C4-18, such as succinic acid, adipic acid, sebacic acid, glutaric acid, azelaic acid, maleic acid, fumaric acid), aromatic dicarboxylic acids (C8- 24, for example, terephthalic acid, isophthalic acid), ester-forming derivatives of these dicarboxylic acids (acid anhydrides, lower alkyl esters having an alkyl group of C 1-4), and combinations of two or more thereof.

  Examples of the lactone of (2) above include C4-12, such as γ-butyrolactone, γ-valerolactone, ε-caprolactone, and combinations of two or more thereof.

  As the polyether ester polyol, for example, one obtained by esterifying one or more of the above polyether polyols and one or more of the polycarboxylic acids exemplified as the raw materials of the polyester polyol or ester forming derivatives thereof, Examples thereof include those obtained by ring-opening addition of one or more lactones to one or more of the polyether polyols.

  Examples of the polycarbonate polyol include polyhexamethylene carbonate diol, polytetramethylene carbonate diol, and combinations of two or more thereof.

  As the polymer polyol, a polyol obtained by polymerizing a vinyl monomer (C3-24, for example, styrene, acrylonitrile) in the presence of a radical polymerization initiator in one or more of the above-described polymer polyols and stabilizing the dispersion. (The polymer content is, for example, 5 to 30% by weight).

  Examples of the polyolefin polyol include polyisobutene polyol.

  Examples of the polyalkadiene polyol include polyisoprene polyol, polybutadiene polyol, hydrogenated polyisoprene polyol, and hydrogenated polybutadiene polyol.

  Examples of the acrylic polyol include a copolymer of an alkyl (meth) acrylate (C1-30) ester [butyl (meth) acrylate and the like] and a hydroxyl group-containing acrylic monomer [hydroxyethyl (meth) acrylate and the like].

  Of these polymer polyols (a2), polyether polyols, polyether ester polyols, polyester polyols and polycarbonate polyols are preferable from the viewpoint of the flexibility of the pressure-sensitive adhesive.

  The low molecular active hydrogen-containing compound (a3) has an OH equivalent or an amine equivalent of less than 250, and (a3) includes a low molecular polyol (a31), a polyamine compound and their ketimines (a32), and a polymerization terminator. And monoamine (a33) and monohydric alcohol (a34).

  The low molecular polyol (a31) has, for example, an aliphatic low molecular diol [C2-12, such as EG, DEG, triethylene glycol (hereinafter abbreviated as TEG), PG, BD, HD, NPG, MPD] and a cyclic group. Low molecular diols (for example, those described in JP-B No. 45-1474: 1,4-bis (hydroxymethyl) cyclohexane, m- or p-xylylene glycol, etc.), and these AO low molar adducts (Mn500 Less than); and combinations of two or more of these.

  Examples of (a32) include polyamines, polyamide polyamines, and ketimines thereof.

  Examples of the polyamine include aromatic diamines [C6-24, such as phenylenediamine, toluenediamine, 4,4′-diaminodiphenylmethane, m- and p-xylylenediamine, diethyltoluenediamine, 2,4- and 2,6- Dimethylthiotoluenediamine]; cycloaliphatic diamine [C6-24, such as isophoronediamine, 4,4′-diaminodicyclohexylmethane, 4,4′-diamino-3,3′-dimethyldicyclohexylmethane, 4,4′-diamino -3,3'-dimethyldicyclohexyl, diaminocyclohexane]; aliphatic diamines [C1-18, such as ethylenediamine, 1,6-hexamethylenediamine]; alkanolamine derivatives [C2-18, such as N- (2-aminoethyl) Ethanolamine]; hydra Emissions or derivatives thereof [C2~18, such as adipic acid dihydrazide]; and mixtures of two or more thereof.

  Examples of the polyamide polyamine include a condensation reaction product of dimer acid (polymerized fatty acid) and excess equivalent amount of ethylenediamine.

  Examples of the ketimine include a reaction product of the above polyamine and a ketone (C3-12, such as acetone, methyl ethyl ketone, methyl isobutyl ketone).

  Of these, ketimine (acetimine) of aliphatic diamine with acetone and acetimine of alicyclic diamine are preferable from the viewpoint of easy molecular weight adjustment.

  Monoamine (a33) used as a polymerization terminator as necessary includes alkyl (C1-8) amine (C1-12, such as ethylamine, butylamine, diethylamine, di-n-butylamine), alkanolamine (C1-12, such as monoamine). Ethanolamine, dipropanolamine, diethanolamine) and the like.

  As monohydric alcohol (a34), C1 or more and Mn300 or less, for example, methanol, ethanol, n-butanol, cellosolve, these AO adducts (less than Mn300), monohydric phenol AO adducts (less than Mn400), etc. are mentioned. It is done.

In the isocyanate compound (b) constituting the thermoplastic polyurethane resin (A) in the present invention, an isocyanate compound (b2) other than the isocyanate compounds (b1) and (b1) having an active energy ray polymerizable group (e) in the molecule is used. ) Is included.
Examples of (b1) include C (excluding carbon in the NCO group) 3 to 13, such as 2- (meth) acryloyloxyethyl isocyanate and 1,1-bis [(meth) acryloyloxymethyl] ethyl isocyanate. .

  As (b2), C (excluding carbon in the NCO group) 2 to 12 aliphatic polyisocyanate [ethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate (HDI), dodecamethylene diisocyanate, 2,2,4-trimethyl Hexane diisocyanate, lysine diisocyanate, 2,6-diisocyanatomethylcaproate, etc.]; C (excluding carbon in NCO group) 4-15 alicyclic polyisocyanate [isophorone diisocyanate (IPDI), dicyclohexylmethane diisocyanate (HMDI) Cyclohexylene diisocyanate, methylcyclohexylene diisocyanate, etc.]; C (excluding carbon in NCO group) 8-12 araliphatic diisocyanate [xylylene diisocyanate (XDI) α, α, α ′, α′-tetramethylxylylene diisocyanate (TMXDI) and the like]; aromatic diisocyanates [2,4- and 2,6-tolylene diisocyanate (TDI), diethylbenzene diisocyanate, 4,4′- and 2,4′-diphenylmethane diisocyanate (MDI), naphthylene diisocyanate, etc.]; modified products of these diisocyanates (modified products containing urethane groups, carbodiimide groups, uretdione groups, isocyanurate groups, burette groups, etc.); and these Two or more types are used in combination.

  Of those exemplified as (b2), aliphatic diisocyanates and alicyclic diisocyanates are preferable from the viewpoint of weather resistance, and HDI, IPDI and HMDI are more preferable.

Examples of the method for producing the thermoplastic polyurethane resin (A) include the following methods (1) to (3), but are not limited thereto.
(1) One-shot method (I)
Active energy ray polymerization with an isocyanate compound (b1) and / or (b2) in the absence of a solvent or in the presence of a solvent (toluene, xylene, ethyl acetate, butyl acetate, dimethylformamide, acetone, methyl ethyl ketone, etc.). Mono and / or polyol of the active hydrogen-containing compound (a1) having a functional group (e), and optionally a high molecular polyol (a2), a low molecular polyol (a31) and / or a monohydric alcohol (a34), The NCO / OH equivalent ratio is preferably 0.8 to 1.0, and more preferably 0.85 to 0.98. A method of removing (A).
(2) One-shot method (II)
In the absence of solvent or in the presence of a solvent, the isocyanate compound (b1) is reacted with the high-molecular polyol (a2) and, if necessary, the low-molecular polyol (a31). [NCO / OH equivalent ratio is a viewpoint of adhesive strength and resin strength. From 0.8 to 1.0, more preferably from 0.85 to 0.98], and in the case of using a solvent, the solvent is removed under reduced pressure to obtain (A).

(3) Prepolymer method An excess isocyanate compound (b2) is reacted with a high molecular polyol (a2) and / or a low molecular polyol (a31) in the absence of a solvent or in the presence of a solvent [NCO / OH equivalent ratio. Is preferably 1.1 to 2.8, more preferably 1.3 to 2.5] an isocyanate group-terminated urethane prepolymer (b-1), and the active hydrogen having (e) in (b-1) The containing compound (a1) and, if necessary, a low molecular polyol (a31) as a chain extender, a polyamine compound and their ketimines (a32), a monoamine (a33) and a monohydric alcohol (a34) as a polymerization terminator In the case of using a solvent, the solvent is removed under reduced pressure to obtain (A). As the active hydrogen-containing compound having (e), monovalent (a1) (monool, monoketimine, monoamine) is reacted with (b-1) to produce (A) having (e) at the molecular end. can do.

Here, the NCO content (% by weight, hereinafter the same) of the prepolymer (b-1) is preferably 1 to 20%, more preferably 2 to 10%, from the viewpoint of melt viscosity and the flexibility of the pressure-sensitive adhesive; The amount of the active hydrogen-containing compound (a1) having (e) is preferably 0.8 to 1. based on 1 equivalent of NCO group in the prepolymer (b-1) from the viewpoint of adhesive strength and resin strength. 0 equivalents, more preferably 0.85 to 0.98 equivalents; the amount of (a31) and / or (a32) used as chain extender is based on 1 equivalent of NCO groups in the prepolymer (b-1) Preferably 0.5 equivalent or less, more preferably 0.3 equivalent or less from the viewpoint of melt viscosity; and the amount of (a33) and / or (a34) used as a polymerization terminator is the prepolymer (b-1) NCO group 1 in Per amount, preferably 0.5 equivalent or less, more preferably from the viewpoint of adhesion and holding power of the pressure-sensitive adhesive is less than 0.3 equivalents.
Among the above methods, a method of producing without solvent is preferable from the viewpoint of no residual solvent, and the method of (2) or (3) is more preferable from the viewpoint of easy molecular weight control.

The thermoplastic polyurethane resin (A) in the present invention has an active energy ray polymerizable group (e) [active energy ray cationic polymerizable group (e1) [propenyl ether] in the molecule (molecular end and / or molecular side chain). Group, vinyl ether group, glycidyl group, etc.] and / or active energy ray radical polymerizable group (e2) [(meth) acryloyl group, propenyl ether group, vinyl ether group, allyl ether group, etc.]] (preferably 2 to 12).
The method for introducing the polymerizable group (e) into the molecule of (A) is not particularly limited. For example, the method using (a1) like the method (1) above; the method (2) above A method using (b1) in the above; a method of synthesizing prepolymer (b-1) and reacting it with (a1) as in the method (3) above.
Among (A) having (e) in the molecule, those having (e) at the molecular ends are preferred from the viewpoint of the adhesiveness of the cured adhesive.

When the urethanization reaction is carried out in the methods (1) to (3), a catalyst usually used for polyurethane can be used if necessary. Specific examples of the catalyst include organic metal compounds [dibutyltin dilaurate, dioctyltin laurate, bismuth carboxylate, bismuth alkoxide, a chelate compound of bismuth with a compound having a dicarbonyl group, etc.], inorganic metal compounds [bismuth oxide, etc. Bismuth hydroxide, bismuth halide, etc.]; amines [triethylamine, triethylenediamine, diazabicycloundecene, etc.] and combinations of two or more of these.
The amount of the catalyst used is not particularly limited, but is usually 0.0001 to 0.1%, preferably 0.001 to 0.01%, based on the weight of (A).
Moreover, in the method of said (1)-(3), when using the compound which has radical polymerizable group (e1) as active hydrogen containing compound (a1) which has active energy ray polymeric group (e), it is an adhesive. For the purpose of maintaining the storage stability of the composition, a polymerization inhibitor (hydroquinone, 4-methoxyphenol, p-benzoquinone, etc.) can be used.
The amount of the polymerization inhibitor used is usually 3,000 ppm or less, preferably 100 to 2,000 ppm, based on the weight of (a1).

Mn of the thermoplastic polyurethane resin (A) in the present invention is 2,500 to 100,000, preferably 4,000 to 80,000. If it is less than 2,500, good adhesive strength cannot be obtained, and if it exceeds 100,000, the melt viscosity becomes high and the coatability deteriorates.
The Mn per active energy ray polymerizable group (e) is preferably 500 to 20,000, more preferably 1,000 to 10,000, and particularly preferably 1,500 to 5,000. By setting Mn per (e) within the above range, a pressure-sensitive adhesive having excellent flexibility and resin strength after curing can be obtained.

  The total content of urethane groups and urea groups in (A) is preferably 0.2 to 20% by weight, more preferably 0.5 to 15% by weight, and particularly preferably 1 to 10%. By setting it as the said range, the adhesive which is excellent in the softness | flexibility and resin strength of the adhesive after hardening can be obtained.

[Thermoplastic polyurethane resin (B)]
In the present invention, the heat of Mn 500 to 1,800 having one or more (preferably 2 to 6) active energy ray polymerizable groups (e) in the molecule and an AO adduct of a bisphenol compound in the molecule. The plastic polyurethane resin (B) is an AO adduct of a bisphenol compound, an active hydrogen-containing compound (a1) having an active energy ray polymerizable group (e), and an isocyanate compound (b) having an Mn of 600 or less. Obtained by reaction.

Examples of AO added to the bisphenol compound constituting (B) include EO, PO, BO, THF, styrene oxide, and combinations of two or more thereof (block and / or random addition). Of these, PO, EO and combinations thereof are preferable from the viewpoint of the resin strength after curing.
The number of moles of AO added is preferably 2 to 20 moles, more preferably 2 to 10 moles, from the viewpoint of reactivity and cohesive strength, with respect to 1 mole of the bisphenol compound. Particularly preferred is 2 to 5 mol.

  Mn of (B) is 600 to 1,800, preferably 900 to 1,300. When Mn is less than 600, the tackiness of the cured product is lowered, and when it exceeds 1,800, the resin strength is lowered.

  Although it does not specifically limit as a manufacturing method of (B), It replaces with high molecular polyol (a2) in the manufacturing method of said (A), and the same manufacturing method by using the AO adduct of a bisphenol compound is used. Can be mentioned.

  The weight ratio of (A) to (B) in the pressure-sensitive adhesive composition of the present invention is preferably 40/60 to 99/1, more preferably 70/30 to 95 /, from the viewpoint of adhesiveness after curing and resin strength. 5.

[Active energy ray polymerization initiator (C)]
Examples of the active energy ray polymerization initiator (C) used in the present invention include an active energy ray cationic polymerization initiator (C1) and an active energy ray radical polymerization initiator (C2).
In the active energy ray-curable hot melt pressure-sensitive adhesive composition of the present invention, when (A) and / or (B) has an active energy ray cationic polymerizable group (e1), (C1) is used, and (A) When (B) has an active energy ray radical polymerizable group (e2), (C2) is used. Further, when (A) and / or (B) has both the active energy ray cationic polymerizable group (e1) and the active energy ray radical polymerizable group (e2), (C1) and (C2) are used in combination. Used.

Examples of the active energy ray cationic polymerization initiator (C1) include a diazonium salt represented by the following general formula (1), an iodonium salt represented by the following general formula (2), and a selenonium salt represented by the following general formula (3). And sulfonium salts represented by the following general formula (4).
[R ¹ N = N] ⁺ · X ⁻ (1)
^{[R 1 R 1 'I]} + · X - (2)
[R ¹ R ¹ 'SeR ² ] ⁺ · X ⁻ (3)
^{[R 1 R 1 'SR 2} ] + · X - (4)
[Wherein R ¹ and R ¹ ′ are C1-12 alkyl group, alkenyl group, aryl group, alkylaryl group and cycloalkyl group (wherein R ¹ and R ¹ ′ are bonded to each other to form N, P, O Or a heterocycle having S as a heteroatom) or a derivative group thereof, wherein R ² is a C1-12 alkyl group, alkenyl group, aryl group, alkylaryl group, a derivative group thereof, or H represents, and X ⁻ represents SbF ₆ ⁻ , AsF ₆ ⁻ , PF ₆ ⁻ or BF ₄ ⁻ . ]

Said (C1) can be used 1 type or in combination of 2 or more types. Among these, an aromatic sulfonium salt in which X ⁻ is SbF ₆ ⁻ or PF ₆ ⁻ among the sulfonium salts represented by the general formula (4) is particularly preferable from the viewpoint of active energy ray cationic polymerization curability. For example, triphenylsulfonium hexafluoroantimonate, triphenylsulfonium hexafluorophosphate, P- (phenylthio) phenyldiphenylsulfonium hexafluoroantimonate, P- (phenylthio) phenyldiphenylsulfonium hexafluorophosphate, 4-chlorophenyldiphenylsulfonium hexa Fluorophosphate, 4-chlorophenyldiphenylsulfonium hexafluoroantimonate, bis [4-diphenyl-sulfonio) phenyl] sulfide-bis-hexaful Orophosphate, bis [4-diphenyl-sulfonio) phenyl] sulfide-bis-hexafluoroantimonate, (2,4-cyclopentadien-1-yl) [(1-methylethyl) benzene] -Fe-hexafluorophosphate, Examples thereof include diphenyl (phenylthiophenyl) sulfonium hexafluorophosphate and diphenyl (phenylthiophenyl) sulfonium hexafluoroantimonate.
These can be easily obtained as commercial products. For example, SP-150, SP-170 [trade names, both manufactured by Asahi Denka Co., Ltd.], Irgacure 261 [trade names, manufactured by Ciba Geigy Co., Ltd.] ], UVR-6974, UVR-6990 [trade names, all manufactured by Union Carbide Co., Ltd.], CPI-100P, CPI-101A [trade names, both manufactured by San Apro Co., Ltd.].

Moreover, as said active energy ray radical polymerization initiator (C2), benzoyl compound [Hydroxybenzoyl compound (2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxycyclohexyl phenyl ketone, benzoin alkyl ether) ), Benzoylformate compound (methylbenzoylformate, etc.)], thioxanthone compound (isopropylthioxanthone, etc.), benzophenone compound (benzophenone, etc.), phosphate ester (1,3,5-trimethylbenzoyldiphenylphosphine oxide, etc.) and benzyl Examples thereof include dimethyl ketal.
These can be easily obtained as commercial products, and examples thereof include Irgacure 184 [trade name, manufactured by Ciba Specialty Chemicals Co., Ltd.].

  Said (C2) can be used 1 type or in combination of 2 or more types. Of these, benzoyl compounds are preferred from the viewpoint of curability, and hydroxybenzoyl compounds are more preferred.

  The amount of (C) used is preferably 0.01 to 10%, more preferably 0.05 to 5%, based on the total weight of (A) and (B). When the amount of (C) used is within the above range, sufficient active energy ray curability and good adhesive strength can be obtained.

[Active energy ray sensitizer (D)]
A known active energy ray sensitizer (D) can be added to the active energy ray-curable hot melt pressure-sensitive adhesive composition of the present invention, if necessary. Examples of the active energy ray cationic polymerization sensitizer include aromatic compounds such as perylene, pyrene, anthracene, coronene, and phenothiazine, and derivatives thereof.
Examples of the active energy ray radical polymerization sensitizer include thiopyrylium salt, merocyanine, quinoline, stilquinoline, aryl ketones, aromatic ketones, and ketocoumarin derivatives.
Examples of the commercially available product (D) include anthracure UVS-1331 [trade name, manufactured by Kawasaki Kasei Kogyo Co., Ltd.].

  The amount of (D) used is preferably 0.01 to 10%, more preferably 0.05 to 5%, based on the total weight of (A) and (B). When the amount of (D) used is within the above range, sufficient active energy ray curability and good adhesive strength can be obtained.

[Additive (E)]
In the active energy ray-curable hot-melt pressure-sensitive adhesive composition of the present invention, a tackifier resin (E1), a plasticizer (E2), a filler (E3), a filler as necessary, as long as the effects of the present invention are not impaired. At least one additive selected from the group consisting of a pigment (E4), an ultraviolet absorber (E5) and an antioxidant (E6) can be further contained.

Examples of the tackifier resin (E1) include terpene resins, terpene phenol resins, phenol resins, aromatic hydrocarbon modified terpene resins, rosin resins, modified rosin resins, synthetic petroleum resins (aliphatic, aromatic and alicyclic synthetic petroleums). Resin), coumarone-indene resin, xylene resin, styrene resin, dicyclopentadiene resin, and hydrogenated products of these having hydrogenated unsaturated double bonds. (E1) may be used alone or in combination of two or more.
The amount of (E1) used is usually 100% or less based on the total weight of (A) and (B), and preferably 5 to 50% from the viewpoint of the adhesive strength and tack of the adhesive.

As the plasticizer (E2), hydrocarbon [process oil, liquid polybutadiene, liquid polyisobutylene, liquid polyisoprene, liquid paraffin, chlorinated paraffin, paraffin wax, copolymer of ethylene and α-olefin (C3-20) (weight) 99.9 / 0.1 to 0.1 / 99.9) oligomer [weight average molecular weight (hereinafter abbreviated as Mw; measured by GPC method) 5,000 to 100,000), α excluding propylene and ethylene -Copolymerized oligomer of olefin (C4-20) (weight ratio 99.9 / 0.1-0.1 / 99.9) oligomer (Mw 5,000-100,000)]; chlorinated paraffin; ester [phthalic acid Esters [diethyl phthalate (DEP), dibutyl phthalate (DBP), di-2-ethylhexyl phthalate (DOP), Didecyl phthalate, dilauryl phthalate, distearyl phthalate, diisononyl phthalate, etc.], adipic acid ester [di (2-ethylhexyl) adipate (DOA), dioctyl adipate, etc.] and sebacic acid ester (dioctyl sebacate, etc.)]; Fats and oils (linoleic acid, linolenic acid, etc.); and hydrogenated products of these having hydrogenated unsaturated double bonds. (E2) may be used alone or in combination of two or more.
The amount of (E2) used is usually 80% or less based on the total weight of (A) and (B), and preferably 2 to 30% from the viewpoint of the adhesive strength and cohesive strength of the adhesive.

As filler (E3), carbonate (magnesium carbonate, calcium carbonate, etc.), sulfate (aluminum sulfate, calcium sulfate, barium sulfate, etc.), sulfite (calcium sulfite, etc.), molybdenum disulfide, silicate (silicate) Aluminum silicate, calcium silicate, etc.), diatomaceous earth, quartzite powder, talc, silica, zeolite and the like.
(E3) is a fine particle having a volume average particle diameter of preferably about 0.01 to 5 μm, and may be used alone or in combination of two or more.
The amount of (E3) used is usually 100% or less based on the total weight of (A) and (B), and preferably 5 to 50% from the viewpoint of tackiness and cohesive strength of the pressure-sensitive adhesive.

As pigment (E4), inorganic pigments (alumina white, graphite, titanium oxide, ultrafine titanium oxide, zinc white, black iron oxide, mica-like iron oxide, lead white, white carbon, molybdenum white, carbon black, resurge, lithopone , Barite, cadmium red, cadmium mercury red, bengara, molybdenum red, red lead, yellow lead, cadmium yellow, barium yellow, strontium yellow, titanium yellow, titanium black, chromium oxide green, cobalt oxide, cobalt green, cobalt chrome green , Ultramarine blue, bituminous blue, cobalt blue, cerulean blue, manganese violet, cobalt violet, etc.) and organic pigments (shellac, insoluble azo pigments, soluble azo pigments, condensed azo pigments, phthalocyanine blue, dyed lakes, etc.).
(E4) is a fine particle having a volume average particle diameter of preferably about 0.01 to 5 μm, and may be used alone or in combination of two or more.
The amount of (E4) used is usually 50% or less based on the total weight of (A) and (B), and preferably 1 to 25% from the viewpoint of tackiness and cohesive strength of the pressure-sensitive adhesive.

Examples of the ultraviolet absorber (E5) include salicylic acid derivatives (phenyl salicylate, salicylic acid-P-octylphenyl, salicylic acid-pt-butylphenyl, etc.), benzophenone compounds [2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxy. Benzophenone, 2,2′-dihydroxy-4-methoxybenzophenone, 2,2′-dihydroxy-4,4′-dimethoxybenzophenone, 2,2′-dihydroxy-4,4′-dimethoxy-5-sulfobenzophenone, 2- Hydroxy-4-methoxy-2′-carboxybenzophenone, 2-hydroxy-4-methoxy-5-sulfobenzophenone trihydrate, 2-hydroxy-4-n-octoxybenzophenone, 2-hydroxy-4-octadecyloxybenzophenone, 2, 2 ', 4 , 4'-tetrahydroxybenzophenone, 4-dodecyloxy-2-hydroxybenzophenone, 2-hydroxy-4- (2-hydroxy-3-methacryloxy) propoxybenzophenone, bis (2-methoxy-4-hydroxy-5-benzoylphenyl) Methane etc.], benzotriazole compounds [2- (2′-hydroxy-5′-methyl-phenyl) benzotriazole, 2- (2′-hydroxy-3 ′, 5′-di-t-butyl-phenyl) benzotriazole 2- (2′-hydroxy-3′-t-butyl-5′-methyl-phenyl) -5-chlorobenzotriazole, 2- (2′-hydroxy-3 ′, 5′-di-t -Butyl-phenyl) -5-chlorobenzotriazole, 2- (2'-hydroxy-4'-n-octoxyphenyl) benzotriazole 2- (2′-hydroxy-5′-t-butylphenyl) benzotriazole, 2- (2′-hydroxy-3 ′, 5′-di-t-amylphenyl) benzotriazole, 2- [2′- Hydroxy-3 '-(3 ", 4", 5 ", 6" -tetrahydrophthalimidomethyl) -5'-methylphenyl] benzotriazole, 2,2-methylenebis [4- (1,1,3,3-tetra Methylbutyl) -6- (2H-benzotriazol-2-yl) phenol], etc.], cyanoacrylate compounds (2-ethylhexyl-2-cyano-3,3′-diphenylacrylate, ethyl-2-cyano-3,3 '-Diphenyl acrylate, etc.). (E5) may be used alone or in combination of two or more.
The amount of (E5) used is usually 5% or less based on the total weight of (A) and (B), and preferably 0.1 to 1% from the viewpoint of the adhesive strength of the adhesive.

Antioxidants (E6) include hindered phenol compounds [triethylene glycol-bis [3- (3-tert-butyl-5-methyl-4-hydroxyphenyl) propionate], pentaerythrityl-tetrakis [3- ( 3,5-di-t-butyl-4-hydroxyphenyl) propionate], 2,2-thio-diethylenebis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] and the like Phosphite compound [Tris (2,4-di-t-butylphenyl) phosphite, 2,2-methylenebis (4,6-di-t-butylphenyl) octyl phosphite, bis (2,6-di -T-butylphenyl) pentaerythritol-di-phosphite, tetrakis (2,4-di-t-butylphenyl) 4,4'-biphe Nylene-di-phosphonite etc.]. These antioxidants may be used alone or in combination of two or more.
The amount of (E6) used is usually 5% or less based on the total weight of (A) and (B), and preferably 0.05 to 1% from the viewpoint of the adhesive strength of the adhesive.

  The total content of the various additives is usually 150% or less based on the total weight of (A) and (B), preferably 100% or less, more preferably 0.1% from the viewpoint of the adhesive strength and tack of the adhesive. ~ 50%.

The active energy ray-curable hot-melt pressure-sensitive adhesive composition of the present invention comprises (A) to (C) and, if necessary, (D) and (E), a known mixing device (a mixing tank equipped with a stirrer, a static mixer). Etc.) can be produced by mixing uniformly. (C), (D), and (E) are preferably mixed after the production of (A) and (B), but some or all of (C), (D), and (E) are pre- It may be added at any stage in the production stage of A) or (B).
The temperature at which (A) to (C) and, if necessary, (D) and (E) are mixed is usually 40 to 200 ° C., and preferably 60 to 180 ° C. from the viewpoint of mixing properties and suppression of thermal deterioration.

As a coating apparatus for the pressure-sensitive adhesive composition of the present invention, a normal hot melt adhesive applicator [a roll coater having a heatable melting tank (gravure roll, reverse roll, etc.), a curtain coater, and a bead, spiral, spray And slot coating machines, etc.], heatable extruders [single- and twin-screw extruders, kneaders, etc.] and the like.
The melting temperature of the pressure-sensitive adhesive composition when applied to an adherend or a support is usually 40 to 180 ° C., preferably 60 to 160 ° C. from the viewpoint of coating properties and thermal deterioration suppression, and melting at the coating temperature. Viscosity is usually from 100 to 200,000 mPa · s, preferably from 500 to 100,000 mPa · s from the viewpoint of moldability (can be thickly coated and free from defects such as warping and sink marks after curing) and coating properties. Preferably, it is 1,000 to 50,000 mPa · s.

  As a support on which the pressure-sensitive adhesive composition is applied, various plastics [polyolefin (polyethylene, polypropylene, etc.), polyurethane, polyethylene terephthalate, polyvinyl chloride, polyamide, etc.] films, sheets, foams and flat yarns, paper (Japanese paper, Crepe paper), metal plate or metal foil, woven fabric, non-woven fabric, and wood.

The active energy ray-curable hot-melt pressure-sensitive adhesive composition of the present invention is applied directly to at least a part of at least one side of these supports to form a coating film, and the coating film is irradiated with active energy rays and cured. By doing so, it is possible to produce a pressure-sensitive adhesive coating (pressure-sensitive adhesive tape, pressure-sensitive adhesive sheet, etc.) having the pressure-sensitive adhesive on at least a part of at least one side of the support. Here, the pressure-sensitive adhesive tape refers to a pressure-sensitive adhesive layer having a thickness of 1 to 500 μm (the thickness of the whole pressure-sensitive adhesive tape is 10 to 1,000 μm), and the pressure-sensitive adhesive sheet has a pressure-sensitive adhesive layer thickness of 0.1 to 5 mm (adhesive). The thickness of the whole sheet is 0.15 to 8 mm).
Also, the pressure-sensitive adhesive composition of the present invention can be applied to a release film or the like in the same manner as described above, and then the pressure-sensitive adhesive molded product obtained by curing with active energy rays is (pressurized) transferred to a support. An agent covering (adhesive tape, adhesive sheet, etc.) can be produced. Moreover, it can peel from a release film and can also be used as an adhesive film as it is.
Moreover, the adhesive of this invention is applicable also as an adhesive or adhesive between two to-be-adhered bodies by replacing the said support body with an to-be-adhered body.
The coating thickness of the pressure-sensitive adhesive after curing with active energy rays is usually from 1 to 5,000 μm, preferably from 5 to 500 μm, more preferably from 10 to 100 μm from the viewpoint of the adhesive strength and curability of the pressure-sensitive adhesive.

The active energy rays in the present invention include ultraviolet rays, electron beams, X-rays, infrared rays and visible rays. Of these active energy rays, ultraviolet rays, visible rays, and infrared rays are preferable from the viewpoints of curability and prevention of resin deterioration.
The wavelength of the active energy ray is preferably 200 to 750 nm, more preferably 200 to 450 nm from the viewpoint of the decomposition efficiency of the active energy ray polymerization initiator (C).

When the pressure-sensitive adhesive composition of the present invention is cured by ultraviolet irradiation, various light sources such as mercury lamp (low pressure, high pressure, ultrahigh pressure, etc.), hydrogen lamp, deuterium lamp, halogen lamp, xenon lamp, carbon arc lamp, fluorescent lamp A lamp, a He—Cd laser, or the like can be used, and a high-pressure mercury lamp is preferable.
The irradiation amount of ultraviolet rays is usually 1 to 1,000 mJ / cm ² , and preferably 10 to 500 mJ / cm ² from the viewpoint of the curability of the composition and the pressure-sensitive adhesive and avoiding damage to the support.

  When the composition of the present invention is cured by electron beam irradiation, various electron beam irradiation apparatuses [for example, Electron Beam, manufactured by Iwasaki Electric Co., Ltd.] can be used. The irradiation amount (Mrad) of the electron beam is preferably 0.5 to 20, and preferably 1 to 15 from the viewpoint of the curability of the composition and the pressure-sensitive adhesive and avoiding damage to the support.

The volume shrinkage ratio of the pressure-sensitive adhesive before and after curing with active energy rays is preferably −3 to 5%, more preferably −from the viewpoint of moldability (thickness can be applied, and there is no appearance defect such as warpage or sink after curing). It is 2 to 4%, particularly preferably -1 to 3%, most preferably 0 to 2%. Here, the cured volume shrinkage is a value calculated based on the following equation by measuring the pressure-sensitive adhesive density (25 ° C.) before and after curing by the method described later.

Curing volume shrinkage (%) = {(density after curing−density before curing) / density before curing} × 100

The active energy ray-curable hot-melt pressure-sensitive adhesive composition of the present invention is applied to one of the adherends through which active energy rays are transmitted, in addition to the use for the above-mentioned pressure-sensitive adhesive tape and pressure-sensitive adhesive sheet. It can also be used as an adhesive that cures and adheres by irradiating active energy rays after the bodies are bonded together.
EXAMPLES Hereinafter, although an Example demonstrates this invention further, this invention is not limited to these. In the following description, “parts” represents parts by weight and “%” represents% by weight.

Synthesis example 1
(Synthesis of OH group-containing propenyl ether)
A SUS autoclave was charged with 200 parts of EO 1 mol adduct of allyl alcohol, 100 parts of polyethylene glycol (Mn400) and 10 parts of KOH, and aged at 160 ° C. for 8 hours (rearrangement reaction) while being agitated. Then, the product was distilled by vacuum distillation to obtain 180 parts of OH group-containing propenyl ether (a-1). As for (a-1), it was confirmed by ¹ H-NMR and ¹³ C-NMR that the rearrangement ratio of the allyl group to the propenyl group was 99%.

Synthesis example 2
(Synthesis of OH group-containing propenyl ether)
An SUS autoclave was charged with 57.1 parts (1 mole) of allyl alcohol and 0.5 parts of KOH, and 232 parts (4 moles) of PO was dropped from a pressure dropping funnel, and the mixture was reacted and aged at 110 ° C. for 5 hours. Further, 0.5 part of KOH was added, and the reaction (rearrangement reaction) was carried out at 160 ° C. for 5 hours, followed by aging. Thereafter, 400 parts of water was added, and excess alkali was washed with water and separated and removed to obtain 231 parts of OH group-containing propenyl ether (a-2). (A-2) confirmed that the rearrangement rate of the allyl group to the propenyl group was 98% by ¹ H-NMR and ¹³ C-NMR.

Synthesis example 3
(Synthesis of OH group-containing acrylic copolymer)
In a four-necked flask equipped with a stirrer, a thermometer, a reflux condenser, a dropping funnel and a nitrogen gas introduction tube, 60 parts of ethyl acetate was charged and the temperature was raised to 75 ° C. Next, with stirring, 182 parts of 2-ethylhexyl acrylate, 1.2 parts of hydroxyethyl acrylate and 90 parts of ethyl acetate were mixed with a monomer, and 0.18 part of 2,2′-azobis (2,4-dimethylvaleronitrile) An initiator solution in which 10 parts of ethyl acetate was dissolved was continuously dropped with a dropping funnel over 4 hours while nitrogen was blown into a four-necked flask to effect radical polymerization. After the completion of dropping, an initiator solution prepared by dissolving 0.36 part of 2,2′-azobis (2,4-dimethylvaleronitrile) in 5 parts of ethyl acetate was continuously added dropwise over 2 hours using a dropping funnel. Added and matured. Furthermore, after continuing the polymerization reaction at the boiling point for 4 hours, the solvent was distilled off under reduced pressure to obtain an OH group-containing acrylic copolymer (a-3). Mn of (a-3) was 40,000.

Synthesis example 4
(Synthesis of OH group-containing acrylic copolymer)
In Synthesis Example 3, 0.18 part of 2,2′-azobis (2,4-dimethylvaleronitrile) during polymerization was replaced with 0.08 part, and 0.36 part during aging was replaced with 0.16 part. Otherwise, an OH group-containing acrylic copolymer (a-4) was obtained in the same manner as in Synthesis Example 3. Mn of (a-4) was 80,000.

Production Example 1
A reaction vessel equipped with a stirrer and a thermometer was charged with 250 parts of PEG-1500 [trade name, PEG of Mn 1,500, manufactured by Sanyo Chemical Industries, Ltd.] and dehydrated at 110 ° C. under a reduced pressure of 10 mmHg for 1 hour. It was. Thereafter, 75 parts of IPDI was added and reacted at the same temperature for 8 hours to obtain a urethane prepolymer having an isocyanate group at the terminal. The NCO content of the prepolymer was 4.4%. Next, 35 parts of OH group-containing propenyl ether (a-1) is added to 325 parts of the prepolymer and reacted at 110 ° C. for 8 hours, so that a thermoplastic polyurethane resin having two propenyl ether groups at the molecular ends (A-1 ) Mn of (A-1) was 2,500.

Production Example 2
In Production Example 1, PEG-1500 was replaced with PTMG-3000 [trade name, manufactured by Mitsubishi Chemical Corporation, polytetramethylene glycol of Mn 3,000], and IPDI 75 parts were replaced with 39 parts Production Example 1 To obtain a urethane prepolymer having an isocyanate group at the terminal. The NCO content of the prepolymer was 2.6%. Next, 18 parts of OH group-containing propenyl ether (a-1) was added to 289 parts of the prepolymer and reacted at 110 ° C. for 8 hours to give a thermoplastic polyurethane resin having two propenyl ether groups (A- 2) was obtained. Mn of (A-2) was 4,000.

Production Example 3
Manufacturing Example 1 except that Kuraray Polyol P6010 [trade name, manufactured by Kuraray Co., Ltd., polyester polyol of Mn 6,000] 250 parts and HDI 14.5 parts were used instead of PEG-1500 and IPDI. In the same manner as in Example 1, a urethane prepolymer having an isocyanate group at the terminal was obtained. The NCO content of the prepolymer was 1.4%. Next, 104.5 parts of hydroxyethyl acrylate and Neostan U-100 [trade name, manufactured by Nitto Kasei Co., Ltd., dibutyltin dilaurate were added to 264.5 parts of the prepolymer whose temperature was adjusted to 85 ° C. same as below. 0.02 part was added and reacted at the same temperature for 8 hours to obtain a thermoplastic polyurethane resin (A-3) having two acryloyl groups at the molecular ends. Mn of (A-3) was 8,000.

Production Example 4
In a reaction vessel equipped with a stirrer and a thermometer, 250 parts of an OH group-containing acrylic copolymer (a-3) was charged, and dehydration was performed at 110 ° C. under a reduced pressure of 10 mmHg for 1 hour. Next, the temperature is adjusted to 85 ° C., and 2.2 parts of 2-acryloyloxyethyl isocyanate and 0.02 part of neostane U-100 are added and reacted at the same temperature for 8 hours. Thermoplastic having 4 acryloyl groups in the molecular side chain A polyurethane resin (A-4) was obtained. The Mn of (A-4) was 40,000.

Production Example 5
In Production Example 4, it has 10 acryloyl groups in the molecular side chain in the same manner as in Production Example 4 except that OH group-containing acrylic copolymer (a-4) was used instead of (a-3). A thermoplastic polyurethane resin (A-5) was obtained. The Mn of (A-5) was 100,000.

Production Example 6
In a reaction vessel equipped with a stirrer and a thermometer, New Paul BPE-20T [trade name, manufactured by Sanyo Chemical Industries, Ltd., EO2 molar adduct of bisphenol A. same as below. 250 parts were charged and dehydrated by heating to 110 ° C. under a reduced pressure of 10 mmHg for 1 hour. Next, the temperature is adjusted to 85 ° C., 202 parts of 2-acryloyloxyethyl isocyanate and 0.02 part of neostane U-100 are added and reacted at the same temperature for 8 hours, and a thermoplastic polyurethane resin having two acryloyl groups at the molecular ends ( B-1) was obtained. Mn of (B-1) was 600.

Production Example 7
In Production Example 1, a urethane prepolymer having an isocyanate group at the terminal was obtained in the same manner as in Production Example 1 except that 150 parts of Newpol BPE-20T and 158 parts of HDI were used instead of PEG-1500 and IPDI, respectively. It was. The prepolymer had an NCO content of 12.8%. Next, 110 parts of 4-hydroxybutyl vinyl ether was added to 308 parts of the prepolymer whose temperature was adjusted to 110 ° C. and reacted at the same temperature for 8 hours, and a thermoplastic polyurethane resin having two vinyl ether groups at the molecular ends (B-2 ) Mn of (B-2) was 900.

Production Example 8
In Production Example 7, two propenyl ether groups were added at the molecular ends in the same manner as in Production Example 7 except that 288 parts of OH group-containing propenyl ether (a-2) was used instead of 110 parts of 4-hydroxybutyl vinyl ether. A thermoplastic polyurethane resin (B-3) was obtained. Mn of (B-3) was 1,300.

Production Example 9
In Production Example 1, urethane having an isocyanate group at the end was produced in the same manner as in Production Example 1 except that 150 parts of New Pole BPE-20T and 208 parts of IPDI were used instead of 250 parts of PEG-1500 and 75 parts of IPDI, respectively. A prepolymer was obtained. The NCO content of the prepolymer was 11.0%. Next, 109 parts of hydroxyethyl acrylate and 0.02 part of neostane U-100 were added to 358 parts of the prepolymer whose temperature was adjusted to 85 ° C., and reacted at the same temperature for 8 hours, thereby thermoplastic polyurethane having two acryloyl groups at the molecular terminals. Resin (B-4) was obtained. Mn of (B-4) was 1,000.

Production Example 10
In Production Example 1, instead of 250 parts of PEG-1500 and 75 parts of IPDI, 150 parts of Newpol BPE-180 [trade name, manufactured by Sanyo Chemical Industries, Ltd., EO18 mol adduct of bisphenol A] and 65 parts of IPDI, respectively. A urethane prepolymer having an isocyanate group at the terminal was obtained in the same manner as in Production Example 1 except that was used. The prepolymer had an NCO content of 6.2%. Next, 34 parts of hydroxyethyl acrylate and 0.02 part of neostane U-100 are added to 215 parts of the prepolymer adjusted to 85 ° C. and reacted at the same temperature for 8 hours, and thermoplastic having two acryloyl groups at the molecular ends. A polyurethane resin (B-5) was obtained. Mn of (B-5) was 1,800.

Examples 1-9, Comparative Examples 1-3
A hot melt pressure-sensitive adhesive composition is prepared by charging a mixture blended according to the formulation shown in Table 1 into a stainless steel pressurized reaction vessel capable of melting and stirring, raising the temperature to 85 ° C. by sealing, and performing melt mixing for 1 hour with stirring. I got a thing. The number of parts in Table 1 represents parts by weight. The active energy ray polymerization initiator (C) and the active energy ray sensitizer (D) used for the blending are as follows.
(C): CPI-101A [trade name, manufactured by Sun Apro Co., Ltd.]
Irgacure 184 [trade name, manufactured by Ciba Specialty Chemicals Co., Ltd.]
(D): Anthracure UVS-1331 [trade name, manufactured by Kawasaki Kasei Kogyo Co., Ltd.]

<Performance evaluation>
The following performance was evaluated about the said adhesive composition and the adhesive after hardening. The results are shown in Table 2.
(1) Evaluation of melt viscosity The melt viscosity at 100 ° C was measured using a B-type viscometer. (JIS K7117)
(2) Evaluation of cure volume shrinkage (density before cure)
The density at 25 ° C. was measured using a hydrometer. [JIS K7112 (Method A underwater replacement method)]
(Density after curing)
Using a bar coater, apply a polyester film of 250 x 250 x 0.025 mm with a silicone release treatment to a thickness of 300 µm (thickness at the time of application), and use an ultraviolet irradiation device (one 80 W / cm high-pressure mercury lamp). Then, the density at 25 ° C. was measured using a hydrometer (same as before curing) of the pressure-sensitive adhesive film (thickened from the polyester film) cured at an irradiation amount of 500 mJ / cm ² .
Based on the obtained density before and after curing, the cured volume shrinkage was calculated from the following formula.

Curing volume shrinkage (%) = {(density after curing−density before curing) / density before curing} × 100

(3) Evaluation of peel strength (preparation of coated specimen)
It is applied to a polyester film of 250 × 250 × 0.025 mm with a bar coater at 80 ° C. so as to be 30 μm (thickness at the time of application), and 500 mJ using an ultraviolet irradiation device (one 80 W / cm high-pressure mercury lamp). Cured with a dose of / cm ² to obtain a coated specimen.
(Measurement of peel strength)
Adhesive surface of the coated specimen is pasted on a stainless steel plate (SUS304) so that the pasting area is 25 mm wide × 100 mm long [one reciprocation with a 2 kg load roller], and 30 minutes after pasting, according to JIS Z0237 The peel strength (unit: N / 25 mm) was evaluated by the following items.
(I) Temperature Dependence of Peeling Strength Peeling strength was measured under the respective atmospheric temperature conditions of 0 ° C., 23 ° C., and 80 ° C. with a peeling speed of 100 mm / min.
(Ii) Dependence of peel strength on peel rate The peel strength was measured under the peel rate conditions of 10 and 1,000 mm / min with the atmospheric temperature kept constant at 23 ° C.

  As is clear from the results in Table 2, the hot melt pressure-sensitive adhesive composition of the present invention has a low viscosity, and the pressure-sensitive adhesive obtained from the composition has a small cured volume shrinkage, and also has a peel strength of the pressure-sensitive adhesive. Since the temperature dependence and the peeling speed dependence are small, it can be seen that it is remarkably superior to the comparative one.

  The active energy ray-curable hot melt pressure-sensitive adhesive composition of the present invention is excellent in coating property because of its low melt viscosity, and excellent in workability (moldability) because of its low cured volume shrinkage. Further, the cured adhesive has a small temperature dependency of the peel strength, and can maintain a good peel strength (adhesive strength) from a low temperature (0 ° C.) to a high temperature (80 ° C.). Because of its low speed dependence, it has an almost constant peel strength (adhesive strength) under various peel speed conditions and is easy to peel off when peeled off. Wiping mats, dust-removing adhesive sheets, photomask adhesive sheets, insulating adhesive sheets for protection of wire connections and conductor connections, hard disk adhesive labels, stickers, inkjet image-receiving adhesive sheets, floor curing adhesives It can be suitably used for a wide range of applications such as a sheet and an adhesive sheet for plating etching protection.

Claims (5)

A thermoplastic polyurethane resin (A) having a number average molecular weight of 2,500 to 100,000 having at least one active energy ray polymerizable group (e) in the molecule, and an active energy ray polymerizable group (e) in the molecule. A thermoplastic polyurethane resin (B) having a number average molecular weight of 600 to 1,800 and an active energy ray polymerization initiator (C) having at least one and having an alkylene oxide adduct of a bisphenol compound in the molecule. An active energy ray-curable hot-melt pressure-sensitive adhesive composition. The pressure-sensitive adhesive composition according to claim 1, wherein the weight ratio of (A) to (B) is 40/60 to 99/1. A pressure-sensitive adhesive obtained by curing the pressure-sensitive adhesive composition according to claim 1 by irradiating active energy rays. The pressure-sensitive adhesive according to claim 3, having a cured volume shrinkage of -3 to 5%. The pressure-sensitive adhesive composition according to claim 1 or 2 is melted and applied to at least a part of at least one side of a support to form a coating film, and the coating film is irradiated with active energy rays and cured. A method for producing a pressure-sensitive adhesive coating.