KR20220053636A - Adhesives, adhesive sheets and optical members - Google Patents

Abstract

The present invention exhibits excellent flexibility, has small temperature dependence of viscoelasticity from low to high temperature, has excellent adhesion to a polar adherend, and can easily control high molecular weight, so that the strength of the adhesive film is improved. An object of the present invention is to provide a urethane pressure-sensitive adhesive having a high balance of performance and less contamination of an adherend.
The present invention is an adhesive containing a polyurethane resin comprising a polyol component (A) having no amino group and an isocyanate component (B) as essential constituent monomers, wherein the weight average molecular weight of the polyurethane resin is 50,000 to 2 million, The polyol component (A) having no amino group contains the polyoxyalkylene polyol (a1), the molecular terminal of the polyoxyalkylene polyol (a1) is a hydroxypropyl group, and the primary hydroxyl group content is It is at least 40 % and is an adhesive whose 180 degree peeling strength on the conditions of 300 mm/min of tensile rate in 23 degreeC when bonding together, crimping|bonding with a 2 kg roller to a glass plate is 5-50 N/25 mm.

Description

Adhesives, adhesive sheets and optical members

The present invention relates to an adhesive, an adhesive sheet, and an optical member.

For optical member sheets, those obtained by laminating an adhesive on a base material (polar adherends such as polyester, polyethylene, polypropylene, and glass) are used. Moreover, in manufacturers of image display apparatuses, such as a liquid crystal display, it is used for the protection use of the optical member in the manufacturing process of a display apparatus (liquid crystal module), pasting of optical members, etc.

Although an acrylic adhesive is mainly used for these optical member sheets, the followability with respect to a to-be-adhered body is good, and the urethane adhesive is also examined for reasons, such as being excellent in a low-temperature characteristic (for example, patent document 1).

However, in the urethane pressure-sensitive adhesive disclosed in Patent Document 1, in order to express the strength of the pressure-sensitive adhesive sheet, it is necessary to use a large amount of a curing agent, increase the crosslinking point, or increase the urethane group concentration, so that the flexibility is insufficient or the low-temperature characteristics are poor. It deteriorated, and there existed a problem, such as an adhesive force falling depending on the kind of to-be-adhered body.

In addition, as in Patent Document 2, when a urethane adhesive is used as a one-component curable adhesive, it is difficult to control the molecular weight during production and it is difficult to raise the molecular weight, so there is a problem such as insufficient cohesive force or a decrease in adhesive strength at high temperature. there was.

Moreover, in the polyurethane urea resin adhesive of patent document 3, when it was difficult to raise molecular weight and it was going to raise molecular weight, there existed a problem, such as the risk of thickening and gelatinization becoming high.

Japanese Laid-Open Patent Publication No. 2006-182795 Japanese Patent Publication No. 6480176 Japanese Patent Laid-Open No. 2001-192636

The object of the present invention is to exhibit excellent flexibility, low temperature dependence of viscoelasticity from low to high temperature, excellent adhesion to a polar adherend, and easy control of high molecular weight. To provide a urethane pressure-sensitive adhesive having high strength and less contamination of an adherend and having a well-balanced performance.

MEANS TO SOLVE THE PROBLEM The present inventors arrived at this invention, as a result of earnestly examining in order to solve the said subject.

That is, this invention is an adhesive containing a polyurethane resin which has an amino group-free polyol component (A) and an isocyanate component (B) as essential constituent monomers, The weight average molecular weight of the said polyurethane resin is 50,000-200 However, the polyol component (A) not having an amino group contains a polyoxyalkylene polyol (a1), and the molecular terminal of the polyoxyalkylene polyol (a1) is a hydroxypropyl group, and The primary hydroxyl group content is at least 40%, and the 180° peeling strength under the condition of a tensile rate of 300 mm/min at 23°C when bonding to a glass plate while pressure-bonding with a 2 kg roller is 5 to 50 N/25 mm adhesive; The adhesive sheet using the said adhesive; It is an optical member using the said adhesive.

The pressure-sensitive adhesive of the present invention exhibits excellent flexibility, has a small temperature dependence of viscoelasticity from low to high temperature, has particularly excellent adhesion to a polar adherend, and can easily control high molecular weight, so the strength of the pressure-sensitive adhesive film It has a good balance performance with high contamination and less contamination of the adherend.

[adhesive]

The pressure-sensitive adhesive of the present invention is an pressure-sensitive adhesive containing a polyurethane resin comprising a polyol component (A) having no amino group and an isocyanate component (B) as essential constituent monomers, and the weight average molecular weight of the polyurethane resin is 50,000 to 200 However, the polyol component (A) not having an amino group contains a polyoxyalkylene polyol (a1), and the molecular terminal of the polyoxyalkylene polyol (a1) is a hydroxypropyl group, and The primary hydroxyl group content is at least 40%, and the 180° peeling strength under the conditions of a tensile rate of 300 mm/min at 23°C when bonding together while being crimped with a 2 kg roller to a glass plate is 5 to 50 N/25 mm .

Hereinafter, the adhesive of this invention is demonstrated.

The adhesive of this invention contains the polyurethane resin which uses the polyol component (A) which does not have an amino group, and the isocyanate component (B) as essential structural monomers.

(Polyol component (A) having no amino group)

The polyol component (A) having no amino group (hereinafter, abbreviated as polyol component (A)) contains a polyoxyalkylene polyol (a1), and the molecular terminal of the polyoxyalkylene polyol (a1) is hydroxy It is a propyl group, and the primary hydroxyl group content rate is at least 40 %.

Confirmation that the polyoxyalkylene polyol (a1) has a hydroxypropyl group at the molecular terminal can be performed, for example, by ¹ H-NMR method.

The hydroxypropyl group includes a primary hydroxyl group (hydroxyl group bonded to a primary carbon atom)-containing group represented by the following formula (1) and a secondary hydroxyl group (hydroxyl group bonded to a secondary carbon atom)-containing group represented by the general formula (1') .

Among all the hydroxypropyl groups contained in the polyoxyalkylene polyol (a1), the ratio of the number of hydroxyl groups bonded to primary carbon atoms (hereinafter referred to as primary hydroxyl group content) is 40% or more, preferably 60 % or more, and more preferably 70% or more.

When the primary hydroxyl group content of all the hydroxypropyl groups contained in the polyoxyalkylene polyol (a1) is less than 40%, sufficient cohesive force and film strength cannot be obtained.

[Formula 1]

[Formula 2]

After pre-processing (esterification) a sample beforehand, the primary hydroxyl group content can measure and calculate|require by ¹ H-NMR method.

The details of the ¹ H-NMR method will be described below.

<Sample preparation method>

About 30 mg of a measurement sample is weighed in the sample tube for NMR with a diameter of 5 mm, and about 0.5 ml of deuterated solvent is added and melt|dissolved. After that, about 0.1 ml of trifluoroacetic anhydride is added to prepare a sample for analysis.

As the deuterated solvent, a solvent capable of dissolving the sample is appropriately selected from, for example, deuterated chloroform, deuterated toluene, deuterated dimethyl sulfoxide, deuterated dimethylformamide, and the like.

<NMR measurement>

¹ H-NMR measurement is performed under normal conditions.

<Calculation method of primary hydroxyl group content>

By the above-mentioned pretreatment method, the hydroxyl group at the terminal of the polyoxyalkylene polyol reacts with the added trifluoroacetic anhydride to form trifluoroacetic acid ester. As a result, the signal derived from the methylene group to which the primary hydroxyl group is bonded is observed at around 4.3 ppm, and the signal derived from the methine group to which the secondary hydroxyl group is bonded is observed at around 5.2 ppm. Primary hydroxyl group content is computed by the following formula.

Primary hydroxyl group content (%) = [x/(x + 2 × y)] × 100

However, x is the integral value of the signal derived from the methylene group couple|bonded with the primary hydroxyl group around 4.3 ppm, and y is the integral value of the signal derived from the methine group couple|bonded with the secondary hydroxyl group around 5.2 ppm.

It is preferable to use the compound represented by General formula (2) as said polyoxyalkylene polyol (a1) from a viewpoint of flexibility, temperature dependence of adhesive force, and adherend species dependence and film thickness dependence of adhesive force.

R ¹ [-(R ² -O)p-(R ³ -O)qH]m (2)

R ¹ in the general formula (2) is an m-valent residue obtained by removing active hydrogen atoms from a compound having m active hydrogen atoms, and m is preferably an integer of 2 to 20.

When m exceeds 20, the viscosity of a polyoxyalkylene polyol (a1) may become high, and the viscosity at the time of coating of a urethane resin solution may become high.

Examples of the compound having m active hydrogen atoms constituting the residue R ¹ include compounds having at least one group selected from a hydroxyl group, a carboxyl group, and a mercapto group, such as a hydroxyl group-containing compound, a carboxyl group-containing compound, and a thiol group.

Examples of the hydroxyl group-containing compound include a low molecular weight polyhydric alcohol having a hydroxyl equivalent of 160 or less [aliphatic polyhydric alcohol [aliphatic dihydric alcohol having 2 to 20 carbon atoms] alkylene glycol, such as ethylene glycol, propylene glycol, 1,3-butylene glycol , 1,4-butanediol, 1,6-hexanediol, 3-methylpentanediol, neopentyl glycol and 1,9-nonanediol; polyhydric alcohols having 3 to 8 carbon atoms or more, such as glycerin, trimethylolpropane, pentaerythritol, sorbitol, xylitol, and mannitol; their intermolecular or intramolecular dehydrates such as dipentaerythritol, polyglycerin (degree of polymerization 2 to 20) and sorbitan; saccharides and their derivatives (glycoside, etc.), for example, glucose, fructose, sucrose and α-methylglucoside; (non)cycloalkylenediol having 6 to 15 carbon atoms {e.g., 1,4-dihydroxycyclohexane, 1,4-bis(hydroxymethyl)cyclohexane and 2,2-bis(4,4'-) hydroxycyclohexyl)propane etc.]; polyhydric alcohols containing an aromatic ring having 8 to 15 carbon atoms [such as m- or p-xylylene glycol and 1,4-bis(hydroxyethyl)benzene]; Castor oil-based polyols (such as castor oil, partially dehydrated castor oil, and partially acylated castor oil); Polymers or oligomers of 2,000 or less number average molecular weight (hereinafter abbreviated as Mn) having m hydroxyl groups [polyalkadiene (C4-10) polyols such as polybutadiene polyol and hydrogenated products thereof; (co)polymer of hydroxyalkyl (C2-4) (meth)acrylate; polyvinyl alcohol (a degree of saponification of 60% or more), etc.]; polyhydric phenols [monocyclic polyhydric phenols (such as pyrogallol, catechol and hydroquinone), bisphenols (such as bisphenol A, bisphenol F and bisphenol S)]; phosphoric acid compounds (such as phosphoric acid, phosphorous acid and phosphonic acid); and mixtures of two or more thereof.

In addition, Mn in this specification can be measured by gel permeation chromatography on condition of the following, for example.

Device: "Waters Alliance 2695" [manufactured by Waters]

Guard column: “Guardcolumn Super H-L” (1 pc.), “TSKgel Super H2000, TSKgel Super H3000, TSKgel Super H4000 [all manufactured by Tosoh Corporation] connected to each”

Sample solution: 0.25 wt% tetrahydrofuran (hereinafter abbreviated as THF) solution

Solution injection volume: 10 μl

Flow rate: 0.6 ml/min

Measuring temperature: 40℃

Detection device: refractive index detector

Reference material: standard polyethylene glycol

In addition, by the weight average molecular weight (Mw) mentioned later in this specification, and gel permeation chromatography, it can measure on condition of the following, for example.

Device:「HLC-8320」[manufactured by Tosoh Corporation]

Guard column: Guardcolumn α [manufactured by Toso Co., Ltd.]

Column: TSKgel α-M [manufactured by Tosoh Corporation]

Sample solution: 0.125% by weight of dimethylformamide (containing 0.01 M LiBr) solution

Solution injection volume: 100 μl

Flow rate: 1 ml/min

Measuring temperature: 40℃

Detection device: refractive index detector

Reference material: standard polystyrene

Examples of the carboxyl group-containing compound include aliphatic polycarboxylic acids having 2 to 36 carbon atoms (succinic acid, glutaric acid, adipic acid, sebacic acid, maleic acid, fumaric acid, dimerized linoleic acid, etc.) and aromatic polycarboxylic acids having 8 to 15 carbon atoms. acids (phthalic acid, isophthalic acid, terephthalic acid, trimellitic acid, pyromellitic acid, etc.), unsaturated carboxylic acid polymers [(meth)acrylic acid (co)polymers having Mn of 2,000 or less], and mixtures of two or more thereof there is.

As the thiol, a polythiol having 2 to 8 valences having 2 to 6 or more carbon atoms (ethanedithiol, propanedithiol, 1,3- or 1,4-butanedithiol, 1,6-hexanedithiol and 3- methyl-1,5-pentanedithiol etc.) and the like.

Among them, from the viewpoint of curability, it is preferably a hydroxyl group-containing compound, more preferably an aliphatic polyhydric alcohol having a hydroxyl equivalent of 160 or less and a castor oil-based polyol, particularly preferably propylene glycol, glycerin, pentaerythritol, dipentaerythritol, polyglycerin (degree of polymerization 2 to 10) and castor oil.

R< ² > in General formula (2) is a C2-C12 alkylene group which may be substituted with a phenyl group or a halogen atom, A C2-C12 linear or branched alkylene group, A C6-C10 cycloalkylene group and those substituted with these phenyl groups, halophenyl groups, or halogen atoms (such as Cl and Br).

Specific examples of R ² include ethylene group, 1,2- or 1,3-propylene group, 1,2-, 2,3-, 1,3- or 1,4-butylene group, and having 5 to 12 carbon atoms. 1,2-alkylene group (1,2-dodecylene group, etc.), 1,2-cyclohexylene group, chloropropylene group, bromopropylene group, phenylethylene group and chlorophenylethylene group.

(R ² -O) in the general formula (2) is obtained by adding an alkylene oxide (hereinafter, abbreviated to AO) to a compound having m active hydrogen atoms constituting the residue R ¹ . As AO used, ethylene oxide (hereinafter, abbreviated as EO), 1,2-propylene oxide (hereinafter, abbreviated as PO), 1,3-propylene oxide, 1,2-, 1,3-, 2,3- or 1,4-butylene oxide (hereinafter, butylene oxide is abbreviated as BO), α-olefin oxide having a carbon urethane group concentration of 5 to 12, epihalohydrin (epichlorohydrin, epibromohydrin, etc.) ), styrene oxide, 1,2-cyclohexene oxide, and combinations of two or more thereof, and when p (R ² -O) is composed of two or more oxyalkylene groups, the bonding mode is either block or random. Any may be sufficient. Among them, PO and 1,2-BO are preferable from the viewpoint of flexibility.

R ³ in the general formula (2) is a propylene group.

p is preferably an integer of 0 to 199, more preferably an integer of 1 to 100, and most preferably an integer of 3 to 30. q is an integer of 1 to 200, preferably 1 ≤ p + q ≤ 200, more preferably 3 ≤ p + q ≤ 100.

Polyoxyalkylene polyol (a1) can be manufactured by the method described in Unexamined-Japanese-Patent No. 2000-344881, for example. Preferred examples of the polyoxyalkylene polyol (a1) include an active hydrogen-containing compound (a0) represented by the following general formula (3) in the presence of a tris(pentafluorophenyl)borane catalyst (hereinafter abbreviated as TPB), The thing obtained by ring-opening addition polymerization of PO, etc. are mentioned. When PO is subjected to ring-opening addition polymerization with a conventional catalyst, β cleavage becomes dominant, so the ratio of secondary hydroxyl groups increases. The polyoxyalkylene polyol (a1) which satisfies the content rate of a radical hydroxyl group can be obtained.

R ¹ [-(R ² -O)pH]m (3)

R ¹ , R ² and m in the general formula (3) are the same as in the general formula (2), and p is 0 or an integer of 1 to 199.

Specific examples of (R ² -O) include the same compounds as those exemplified as compounds having m active hydrogen atoms constituting the residue of the general formula (2) when p is 0.

The active hydrogen-containing compound (a0) when p is 1 or more is a polyol obtained by (co)addition of R ² -O to a compound constituting the residue R ¹ using a conventionally known catalyst (alkali metal hydroxide, etc.) , preferred examples include PO adduct of propylene glycol, PO adduct of glycerin, PO adduct of polyglycerin, 1,2-BO adduct of propylene glycol, 1,2-BO adduct of glycerin, 1 of polyglycerin, 2-BO adduct, PO/1,2-BO co-adduct of glycerin (block or random), and the like.

The amount of TPB to be used in producing the polyoxyalkylene polyol (a1) by ring-opening addition polymerization of PO to the active hydrogen-containing compound (a0) is not particularly limited, but is preferably based on the weight of the polyoxyalkylene polyol (a1) Preferably it is 0.00005 to 10 weight%, More preferably, it is 0.0001 to 1 weight%.

The number of moles added of PO is 1 to 200 moles, preferably 2 to 100 moles, more preferably 3 to 30 moles per active hydrogen atom of the active hydrogen-containing compound (a0).

The number of added moles of all AOs (the sum of AO in the first step and PO in the second step) per one active hydrogen atom of the compound constituting the residue R ¹ is 1 to 200 moles, preferably 3 to 100 moles. When the number of these added moles exceeds 200 moles, the viscosity of the polyoxyalkylene polyol (a1) increases, and the viscosity at the time of coating the mixed solution of the main agent and the curing agent increases.

The reaction temperature at the time of ring-opening addition polymerization of PO becomes like this. Preferably it is 0-250 degreeC, More preferably, it is 20-180 degreeC. From the viewpoint of controlling the reaction temperature, a method in which PO is added dropwise to a mixture of the active hydrogen-containing compound (a0) and TPB or a mixture of PO and TPB is added dropwise to the active hydrogen-containing compound (a0) is preferred.

Since the prepared addition polymer contains TPB, it is adsorbed and removed using an adsorbent such as synthetic silicate (magnesium silicate and aluminum silicate, etc.) and activated clay.

As a preferable specific example of polyoxyalkylene polyol (a1), polypropylene glycol, polypropylene triol, etc. are mentioned.

Polyoxyalkylene polyol (a1) may be used individually by 1 type, or may use 2 or more types together.

The total degree of unsaturation of the polyoxyalkylene polyol (a1) is preferably 0.025 meq/g or less, more preferably 0.015 meq/g or less, and still more preferably 0.010 meq/g or less.

By setting the total degree of unsaturation of the polyoxyalkylene polyol (a1) to 0.025 meq/g or less, the cohesive force of the cured product of the urethane pressure-sensitive adhesive is improved, and contamination of the adherend can be reduced by reducing the low molecular weight component. In addition, the total unsaturation in this invention can be measured by the method of JISK1557-3.

The total degree of unsaturation of all the polyol components contained in the polyol component (A) having no amino group is preferably 0.001 to 0.025 meq/g, more preferably 0.003 to 0.020 meq/g, particularly preferably 0.005 to 0.015 meq/g. is meq/g.

When the total degree of unsaturation of all polyol components contained in the polyol component (A) is 0.025 meq/g or less, the cohesive force of the cured product of the urethane pressure-sensitive adhesive is improved, and the total unsaturation of (A) is 0.001 meq/g or more. this is obtained That is, by setting it as the said range, the performance of cohesive force and adhesive force can be made compatible.

The hydroxyl value of the polyoxyalkylene polyol (a1) depends on the presence or absence of a polyol (a2) other than the polyoxyalkylene polyol (a1) described later and the type of polyol used in combination from the viewpoint of adhesive strength and viscoelastic properties of the pressure-sensitive adhesive. Although different, Preferably it is 5-800 mgKOH/g, More preferably, it is 10-450 mgKOH/g, Especially preferably, it is 20-300 mgKOH/g.

The content of the polyoxyalkylene polyol (a1) in the polyol component (A) is preferably 20% by weight or more, more preferably 50% by weight or more, particularly preferably based on the weight of the polyol component (A). is 70% by weight or more. When the content of the polyoxyalkylene polyol (a1) is 20% by weight or more, flexibility, temperature dependence of adhesive force, and adherend species dependence and film thickness dependence of adhesive force are favorable.

The polyol component (A) may contain a polyol (a2) [hereinafter, abbreviated as polyol (a2)] other than the polyoxyalkylene polyol (a1).

Examples of the polyol (a2) include a polyoxyalkylene polyol (a21) other than the polyoxyalkylene polyol (a1), and a hydroxyl group-containing compound (a22) described as a compound having m active hydrogen atoms constituting the residue R ¹ . ), polyester polyol (a23), and the like.

Examples of the polyoxyalkylene polyol (a21) other than the polyoxyalkylene polyol (a1) include a polyoxyalkylene polyol whose molecular terminal is not a hydroxypropyl group, and a hydroxypropyl group whose molecular terminal is a primary hydroxyl group The polyoxyalkylene polyol etc. whose content rate is less than 40 % are mentioned.

Examples of the polyester polyol (a23) include castor oil fatty acid ester polyols (eg, castor oil, partially dehydrated castor oil, and castor oil fatty acid ester); poly (n = 2 to 3 or more) carboxylic acids [aliphatic saturated or unsaturated polycarboxylic acids having 2 to 40 carbon atoms, such as oxalic acid, adipic acid, azelaic acid, dodecanoic acid, maleic acid, fumaric acid, it Conic acid and dimerized linoleic acid), aromatic ring-containing polycarboxylic acids (8 to 15 carbon atoms, such as phthalic acid, isophthalic acid, terephthalic acid and 2,6-naphthalenedicarboxylic acid) and alicyclic polycarboxylic acids (7 carbon atoms) to 15, for example 1,3-pentanedicarboxylic acid and 1,4-hexanedicarboxylic acid) and polyols [for example, the hydroxyl group-containing compound, polyoxyalkylene polyol (a1) and polyol ( a2) etc.] linear or branched polyester polyols; A polylactone polyol [for example, one or a mixture of two or more of the above hydroxyl group-containing compounds (2 to trivalent) is used as an initiator, and (substituted) caprolactone (6 to 10 carbon atoms, for example ε-caprolactone, A polyol obtained by addition polymerization of α-methyl-ε-caprolactone and ε-methyl-ε-caprolactone in the presence of a catalyst (organometallic compound, metal chelate compound, fatty acid metal acyl compound, etc.) (e.g. polycaprolactone polyol) )] ; Polyether ester polyol obtained by adding AO (EO, PO, etc.) to polyester which has a carboxyl group and/or a hydroxyl group at the terminal; polycarbonate polyol; and the like.

Of the polyol (a2), from the viewpoints of curability and flexibility and toughness of the cured product of the pressure-sensitive adhesive, a low molecular weight polyhydric alcohol having a hydroxyl equivalent of 160 or less in the hydroxyl group-containing compound (a22), an aliphatic polycarboxylic acid having 2 to 6 carbon atoms and a carbon number It is polyesterdiol which consists of 2-8 alkyldiol.

A polyol (a2) may be used individually by 1 type, or may use 2 or more types together.

The hydroxyl value of the polyol (a2) is preferably 10 to 1500 mgKOH/g, more preferably 20 to 500 mgKOH/g, and particularly preferably 30 to 150 mgKOH/g from the viewpoint of flexibility and curability. .

From a sclerosis|hardenable viewpoint, the number average functional group number of a polyol (a2) becomes like this. Preferably it is 2-5, More preferably, it is 2-4, Especially preferably, it is 2-3.

When the polyol (a2) is used, the content of the polyol (a2) is preferably 5 to 95 wt%, more preferably 10 to 95 wt%, based on the weight of the polyol component (A) from the viewpoint of the viscoelastic properties of the adhesive It is 90 weight%, Especially preferably, it is 20 to 80 weight%.

A polyol component (A) may contain a monool, unless the effect of this invention is affected. Methanol, ethanol, etc. are mentioned as a monool.

(isocyanate component (B))

Examples of the isocyanate component (B) include a C4-C22 chain aliphatic polyisocyanate (b1) having 2 to 3 or more isocyanate groups, an alicyclic polyisocyanate (b2) having 8 to 18 carbon atoms, and an alicyclic polyisocyanate (b2) having 8 to 26 carbon atoms. and aromatic polyisocyanate (b3), aromatic aliphatic polyisocyanate (b4) having 10 to 18 carbon atoms, and modified products (b5) of these polyisocyanates. An isocyanate component (B) may be used individually by 1 type, and may use 2 or more types together.

Examples of the chain aliphatic polyisocyanate (b1) having 4 to 22 carbon atoms include ethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate (hereinafter abbreviated as HDI), dodecamethylene diisocyanate, 1,6,11 -Undecanetriisocyanate, 2,2,4-trimethylhexamethylenediisocyanate, lysine diisocyanate, 2,6-diisocyanatomethylcaproate, bis(2-isocyanatoethyl)fumarate, bis(2-iso Cyanatoethyl) carbonate and 2-isocyanatoethyl-2,6-diisocyanatohexanoate, etc. are mentioned.

Examples of the alicyclic polyisocyanate (b2) having 8 to 18 carbon atoms include isophorone diisocyanate (hereinafter abbreviated as IPDI), 4,4'-dicyclohexylmethane diisocyanate (hereinafter abbreviated as hydrogenated MDI), Cyclohexylene diisocyanate, methylcyclohexylene diisocyanate, bis(2-isocyanatoethyl)-4-cyclohexene-1,2-dicarboxylate and 2,5- or 2,6-norbornane diisocyanate and the like.

Examples of the aromatic polyisocyanate (b3) having 8 to 26 carbon atoms include 1,3- or 1,4-phenylene diisocyanate, 2,4- or 2,6-tolylene diisocyanate (hereinafter abbreviated as TDI), and preparation. (粗製) TDI, 4,4'- or 2,4'-diphenylmethane diisocyanate (hereinafter abbreviated as MDI), crude MDI, polyallyl polyisocyanate, 4,4'-diisocyanatobiphenyl, 3, 3'-dimethyl-4,4'-diisocyanatobiphenyl, 3,3'-dimethyl-4,4'-diisocyanatodiphenylmethane, 1,5-naphthylene diisocyanate, 4,4',4 "-triphenylmethane triisocyanate and m- or p-isocyanatophenylsulfonyl isocyanate, etc. are mentioned.

Examples of the aromatic aliphatic polyisocyanate (b4) having 10 to 18 carbon atoms include m- or p-xylylene diisocyanate and α,α,α′,α′-tetramethylxylylene diisocyanate.

As the polyisocyanate modified product (b5) of the polyisocyanates (b1) to (b4), the modified product of the polyisocyanate (urethane group, carbodiimide group, allophanate group, urea group, biuret group, uretodione group, A modified product containing a uretoimine group, an isocyanurate group, or an oxazolidone group, etc. The free isocyanate group content is preferably 8 to 33% by weight, more preferably 10 to 30% by weight, particularly 12 to 29% by weight ), for example, modified MDI (urethane modified MDI, carbodiimide modified MDI and trihydrocarbyl phosphate modified MDI, etc.), urethane modified TDI, biuret modified HDI, isocyanurate modified HDI and isocyanurate modified IPDI, etc. and modified products of polyisocyanate of

Among these organic polyisocyanates, from the viewpoint of the color of the cured product of the pressure-sensitive adhesive, chain aliphatic polyisocyanate (b1) having 4 to 22 carbon atoms and alicyclic polyisocyanate (b2) having 8 to 18 carbon atoms are more preferred, and more preferably It is a C4-C22 linear aliphatic polyisocyanate (b1).

(Amine having a hydroxyl group (C))

It is preferable that the polyurethane resin further contains an amine (C) having a hydroxyl group as a constituent monomer, the hydroxyl value of the amine (C) having a hydroxyl group is 50 to 1200 mgKOH/g, and the amine value is 50 to 1200 mgKOH/g Do.

The hydroxyl value of the amine (C) having a hydroxyl group is preferably 50 to 1200 mgKOH/g, more preferably 100 to 1100 mgKOH/g, particularly preferably 200 to 1000 mgKOH, from the viewpoint of cohesive force and adhesive force of the pressure-sensitive adhesive. /g.

The hydroxyl value in this invention can be measured by the method of JISK1557-1.

The amine titer of the amine (C) having a hydroxyl group is preferably 50 to 1200 mgKOH/g, more preferably 100 to 1150 mgKOH/g, particularly preferably 200 to 1100 mgKOH/g, from the viewpoint of cohesive force and adhesive force of the pressure-sensitive adhesive. is g. The amine titer in this invention can be measured by the method of JISK7237.

As the amine (C) having a hydroxyl group, a monoamine (c1) having a hydroxyl group and a diamine (c2) having a hydroxyl group are contained, and the content of the monoamine (c1) having a hydroxyl group is that of the amine (C) having a hydroxyl group It is 0.5 to 50 weight% based on the total weight, and it is preferable that content of the diamine (c2) which has a hydroxyl group is 50 to 99.5 weight% based on the total weight of the amine (C) which has a hydroxyl group.

As monoamine (c1) which has a hydroxyl group, a C2-C18 mono- or dialkanol monoamine of a hydroxyalkyl group, etc. are mentioned.

Specific examples of the mono or dialkanol monoamine having 2 to 18 carbon atoms in the hydroxyalkyl group include monoethanolamine, diethanolamine, propanolamine and monoisopropanolamine.

Monoamine (c1) which has a hydroxyl group may be used individually by 1 type, or may use 2 or more types together.

Among these, from the viewpoint of adhesive force and cohesive force of the pressure-sensitive adhesive, it is preferably mono or dialkanol monoamine having 2 to 18 carbon atoms in the hydroxyalkyl group, and more preferably monoalkanol monoamine having 2 to 18 carbon atoms in the hydroxyalkyl group. am.

As diamine (c2) which has a hydroxyl group, C2-C18 mono- or dialkanoldiamine of a hydroxyalkyl group is mentioned.

Specific examples of the monoalkanoldiamine having 2 to 18 carbon atoms in the hydroxyalkyl group include N-(2-aminoethyl)ethanolamine and N-(2-hydroxypropyl)ethylenediamine.

Diamine (c2) which has a hydroxyl group may be used individually by 1 type, or may use 2 or more types together.

Among these, from the viewpoint of ease of making the polyurethane resin high in molecular weight, adhesive force and cohesive force of the pressure-sensitive adhesive, etc., it is preferably mono or dialkanoldiamine having 2 to 18 carbon atoms in the hydroxyalkyl group, more preferably the hydroxyalkyl group It is a C2-C18 monoalkanoldiamine.

As an amine (C) which has a hydroxyl group, you may contain the amine (c3) which has a hydroxyl group and a trifunctional or more than trifunctional amino group.

Examples of the amine (c3) having a hydroxyl group and a trifunctional or higher amino group include N,N'-bis(hydroxyethyl)diethylenetriamine, N,N'-bis(hydroxyethyl)triethylenetetramine, and the like. there is.

The amine (c3) which has a hydroxyl group and a trifunctional or more than trifunctional amino group may be used individually by 1 type, or may use 2 or more types together.

The amine (C) having a hydroxyl group preferably contains a diamine (c2) having a hydroxyl group from the viewpoints of ease of high molecular weight of the polyurethane resin, adhesive force and cohesive force of the pressure-sensitive adhesive, and a monoamine (c1) having a hydroxyl group. ) and diamine (c2) having a hydroxyl group are more preferably contained.

The content of the monoamine (c1) having a hydroxyl group is preferably 0.5 to 50% by weight based on the total weight of the amine (C) having a hydroxyl group from the viewpoint of the viscosity and adhesive strength of the polyurethane resin solution, and more preferably is 1 to 40% by weight, particularly preferably 3 to 30% by weight.

The content of the diamine (c2) having a hydroxyl group is preferably 50 to 99.5% by weight based on the total weight of the amine (C) having a hydroxyl group from the viewpoint of film strength and adhesive strength of the polyurethane resin solution, more preferably is 60 to 99% by weight, particularly preferably 70 to 97% by weight.

The content of the amine (c3) having a hydroxyl group and a trifunctional or higher amino group is preferably 0 to 30% by weight based on the total weight of the amine (C) having a hydroxyl group from the viewpoint of the viscosity of the polyurethane resin solution, further Preferably it is 0 to 15 weight%, Especially preferably, it is 0 to 5 weight%.

(Polyurethane resin)

The polyurethane resin contained in the pressure-sensitive adhesive of the present invention may be obtained by polymerizing the polyol component (A), the organic polyisocyanate component (B), and, if necessary, the amine (C) having a hydroxyl group by a known method. there is.

Among them, a chain extender (X) in which the polyurethane resin includes a urethane prepolymer (P) obtained by reacting the polyol component (A) and the isocyanate component (B), and an amine (C) having a hydroxyl group ), the amine (C) having a hydroxyl group is a mixture containing a monoamine (c1) having a hydroxyl group and a diamine (c2) having a hydroxyl group, the content of the monoamine (c1) having a hydroxyl group and a hydroxyl group It is preferable that the sum total of content of a diamine (c2) is 5 to 100 weight% based on the total weight of the chain extender (X) containing the amine (C) which has a hydroxyl group.

The said urethane prepolymer (P) can be obtained by making a polyol component (A) and an isocyanate component (B) react by a conventional method.

The isocyanate group concentration of the urethane prepolymer (P) is preferably 0.4 to 15% by weight, more preferably 0.6 to 8.4% by weight, particularly preferably 0.8 to 4.2% by weight, and most preferably 1.1 to 2.8% by weight.

When the isocyanate group concentration of the urethane prepolymer (P) exceeds 15% by weight, the elastic modulus of the polyurethane resin obtained is excessively high and the adhesive force may be lowered. There are cases.

As the method for producing the urethane prepolymer (P), a known method for producing urethane can be used, and for example, a solvent (toluene, xylene, ethyl acetate, butyl acetate, dimethylformamide, acetone, methyl ethyl ketone and THF). etc.) in presence or absence, the method of making a polyol component (A) and an isocyanate component (B) react is mentioned. By adjusting the ratio of the number of moles of active hydrogen-containing groups of the polyol component (A) to the number of moles of isocyanate in the isocyanate component (B), a urethane prepolymer having a hydroxyl group at the terminal or a urethane prepolymer having an isocyanate group at the terminal can be prepared can

For the reaction of the polyol component (A) and the isocyanate component (B), a known reaction apparatus (a mixing tank equipped with a stirrer, a static mixer, etc.) can be used, and the reaction temperature is preferably from the viewpoint of reactivity and suppression of thermal deterioration. is 10 to 160°C, more preferably 25 to 120°C, and from the viewpoint of stability, it is preferable to replace the gas phase part with nitrogen.

The ratio of moles of isocyanate groups in the isocyanate component (B) to the moles of active hydrogen-containing groups in (A) in the case of reacting the polyol component (A) with the isocyanate component (B) (number of moles of isocyanate groups/active hydrogen-containing groups) from the viewpoint of the strength and adhesive force of the cured product of the pressure-sensitive adhesive obtained, preferably 0.5 to 2.0, more preferably 0.6 to 1.9, and most preferably 0.7 to 1.8.

The polyurethane resin contained in the pressure-sensitive adhesive of the present invention is obtained by reacting a chain extender (X) containing an amine (C) having a hydroxyl group with the urethane prepolymer (P), and the urethane prepolymer (P) is chain-extended. It is preferable to obtain

As a method of reacting the chain extender (X) with the urethane prepolymer (P), a solvent (toluene, xylene, ethyl acetate, butyl acetate, dimethylformamide, acetone, isopropyl alcohol, methyl ethyl ketone and tetrahydrofuran) etc.) in the presence or absence of a chain extender (X) and a method of reacting the urethane prepolymer (P).

It is preferable that the chain extender (X) is a mixture containing, as the amine (C) having a hydroxyl group, the monoamine (c1) having a hydroxyl group and the diamine (c2) having a hydroxyl group.

The chain extender (X) may contain, in addition to the hydroxyl group-containing amine (C), an amine (x1) not having a hydroxyl group and a hydroxyl group-containing compound (x2) not having an amino group.

Examples of the hydroxyl group-free amine (x1) include mono or diamine having 2 to 12 carbon atoms, poly (n = 2 to 6) alkylene (2 to 6 carbon atoms) poly (n = 3 to 7) amine and polyoxyalkylene. Glycol polyamine etc. are mentioned.

Examples of the mono or diamine having 2 to 12 carbon atoms include n-butylamine, di-n-butylamine, ethylenediamine, propylenediamine, hexamethylenediamine, isophoronediamine, toluenediamine and piperazine.

Examples of poly(n = 2 to 6) alkylene (2 to 6 carbon atoms) poly (n = 3 to 7) amines include diethylenetriamine, dipropylenetriamine, dihexylenetriamine, triethylenetetramine, tetra Ethylene pentamine, pentaethylene hexamine, hexaethylene heptamine, etc. are mentioned.

Examples of the polyoxyalkylene glycol polyamine include polypropylene glycol diamine and polytetramethylene ether glycol diamine.

Examples of the hydroxyl group-containing compound (x2) having no amino group include an aliphatic dihydric alcohol having 2 to 20 carbon atoms (alkylene glycol, such as ethylene glycol, propylene glycol, 1,3-butylene glycol, 1,4-butanediol, 1 , 6-hexanediol, 3-methylpentanediol, neopentyl glycol, 1,9-nonanediol, etc.) are mentioned.

The amine (x1) which does not have a hydroxyl group, and the hydroxyl-containing compound (x2) which does not have an amino group may be used individually by 1 type, or may use 2 or more types together.

Among the amine (x1) having no hydroxyl group and the hydroxyl group-containing compound (x2) not having an amino group, from the viewpoint of easiness of increasing the molecular weight of the polyurethane resin and the color of the cured product of the adhesive, preferably an amine having no hydroxyl group (x1) ), more preferably mono or diamine having 2 to 12 carbon atoms, and particularly preferably aliphatic or alicyclic diamine having 6 to 10 carbon atoms.

The amine (C) having a hydroxyl group contained in the chain extender (X) is a mixture containing a monoamine (c1) having a hydroxyl group and a diamine (c2) having a hydroxyl group from the viewpoint of the curability of the obtained urethane resin, The sum of the content of the monoamine (c1) having a hydroxyl group and the content of the diamine (c2) having a hydroxyl group is 5 based on the total weight of the chain extender (X) containing the amine (C) having a hydroxyl group It is preferable that it is -100 weight%, 10-100 weight% is more preferable, 20-100 weight% is especially preferable, and 30-100 weight% is the most preferable.

When the chain extender (X) and the urethane prepolymer (P) are reacted, the weight ratio of the chain extender (X) to the urethane prepolymer (P) [chain extender (X)/urethane prepolymer (P)] is preferably Preferably it is 0.01/1 to 1/1, More preferably, it is 0.015/1 to 0.7/1, Most preferably, it is 0.02/1 to 0.5/1.

When the weight ratio of the chain extender (X) to the urethane prepolymer (P) [chain extender (X)/urethane prepolymer (P)] exceeds 1/1 or is less than 0.01/1, the molecular weight of the urethane resin is insufficient. The adhesive force and cohesive force of an adhesive may be insufficient.

When the chain extender (X) and the urethane prepolymer (P) are reacted, the hydroxyl group-containing amine (C) contained in the chain extender (X) is the hydroxyl group-containing monoamine (c1) and the hydroxyl group It is preferable to contain a mixture of diamines (c2), and from the viewpoint of molecular weight control, the weight ratio of the monoamine (c1) having a hydroxyl group to the diamine (c2) having a hydroxyl group is the monoamine (c1)/hydroxyl group having a hydroxyl group. The diamine (c2)b to have is preferably 0.001/1 to 1/1, more preferably 0.01/1 to 0.7/1, and most preferably 0.03/1 to 0.5/1.

The weight average molecular weight of the polyurethane resin is 50,000 to 2 million, preferably 80,000 to 2 million, more preferably 100,000 to 1 million, particularly preferably 150,000 to 800,000, most preferably It is usually between 200,000 and 600,000.

When the weight average molecular weight of the polyurethane resin exceeds 2 million, there is a problem that the viscosity becomes too high to impair productivity and workability at the time of coating, and when it is less than 50,000, there is a problem that the adhesive force and cohesive force of the pressure-sensitive adhesive are insufficient.

The hydroxyl value of the polyurethane resin is preferably 1 to 50 mgKOH/g, more preferably 2 to 40 mgKOH/g, particularly preferably 3 to 30 mgKOH/g, from the viewpoint of the adhesive force and cohesive force of the adhesive. and most preferably 5 to 20 mgKOH/g.

The urethane group concentration of the polyurethane resin is preferably 1 to 40% by weight, more preferably 2 to 30% by weight, particularly preferably 3 to 20% by weight, most preferably from the viewpoint of adhesive strength. It is 5 to 15 weight%.

The urea group concentration of the polyurethane resin is preferably 0.5 to 15% by weight, more preferably 1 to 10% by weight, particularly preferably 1.5 to 7% by weight, most preferably from the viewpoint of adhesive strength. It is 2 to 5 weight%.

(adhesive)

The pressure-sensitive adhesive of the present invention may be a single-component curable pressure-sensitive adhesive or a two-component curable pressure-sensitive adhesive containing the polyurethane resin as a main component.

The 180 degree peeling strength in the conditions of the tensile rate 300 mm/min in 23 degreeC when the adhesive of this invention is bonded together, pressure-bonding with a 2 kg roller to a glass plate is 5-50 N/25 mm.

The said peeling strength bonds together, for example, crimping|bonding the adhesive sheet cut to the size of 200 mm x 25 mm to a glass plate with a 2 kg roller, and produces the sheet|seat for peeling tests. Thereafter, 180° peel strength (unit: N/25 mm) is measured with respect to the sheet for peel test using a tensile tester under the conditions of a tensile rate of 300 mm/min.

Peeling strength of the adhesive of this invention is 5 N/25 mm or more, It is preferable that it is 10 N/25 mm or more, It is more preferable that it is 15 N/25 mm or more.

When the pressure-sensitive adhesive of the present invention is a one-component curable pressure-sensitive adhesive, additives such as antioxidants, ultraviolet absorbers, plasticizers, tackifiers, fillers, pigments, antistatic agents and anti-gelling agents may be additionally contained as needed.

As the antioxidant, a hindered phenol compound [triethylene glycol-bis[3-(3-t-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] and a phosphorous acid ester compound [tris(2,4-di-t-butylphenyl)phosphite, 2,2-methylenebis(4,6-di-t-butylphenyl)octylphosphite, Bis(2,6-di-t-butylphenyl)pentaerythritol-di-phosphite, tetrakis(2,4-di-t-butylphenyl)4,4'-biphenylene-di-phosphonite etc.] can be mentioned.

These antioxidants may be used individually by 1 type, or may use 2 or more types together.

The amount of the antioxidant used is preferably 5% by weight or less, and more preferably 0.05 to 1% by weight from the viewpoint of the antioxidant effect and adhesive strength based on the weight of the one-component curable pressure-sensitive adhesive.

Examples of the ultraviolet absorber include salicylic acid derivatives (phenyl salicylate, salicylic acid-P-octylphenyl, salicylic acid-P-tertbutylphenyl, etc.), benzophenone compounds [2,4-dihydroxybenzophenone, 2-hydroxy-4- Methoxybenzophenone, 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 compound ｛2-(2'-hydroxyl-5'-methyl-phenyl)benzotriazole, 2-(2'-hydroxyl-3',5'-di-t-butyl-phenyl)benzotriazole Sol, 2-(2'-hydroxyl-3'-t-butyl-5'-methyl-phenyl)-5-chlorobenzotriazole, 2-(2'-hydroxyl-3',5'-di- t-Butyl-phenyl)-5-chlorobenzotriazole, 2-(2'-hydroxyl-4'-n-octoxyphenyl)benzotriazole, 2-(2'-hydroxyl-5'-t- Butylphenyl)benzotriazole, 2-(2'-hydroxyl-3',5'-di-t-amylphenyl)benzotriazole, 2-[2'-hydroxyl-3'-(3",4) ",5",6"-tetrahydrophthalimidemethyl)-5'-methylphenyl]benzotriazole, 2,2-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6 -(2H-benzotriazol-2-yl)phenol] etc., cyanoacrylate compound (2-ethylhexyl-2-cyano-3,3'-diphenyl acrylate, ethyl-2-cyano- 3,3'-diphenyl acrylate etc.) etc. are mentioned.

A ultraviolet absorber may be used individually by 1 type, or may use 2 or more types together.

The amount of the ultraviolet absorber to be used is preferably 5% by weight or less, and more preferably 0.1 to 1% by weight from the viewpoint of the ultraviolet absorption effect and adhesive strength based on the weight of the one-component curable pressure-sensitive adhesive.

As the plasticizer, hydrocarbons [process oil, liquid polybutadiene, liquid polyisobutylene, liquid polyisoprene, liquid paraffin, chlorinated paraffin, paraffin wax, ethylene and α-olefin (3 to 20 carbon atoms) copolymerization (weight ratio 99.9/0.1) to 0.1/99.9) oligomer (weight average molecular weight 5,000 to 100,000), copolymer oligomer (weight ratio 99.9/0.1 to 0.1/99.9) of propylene and α-olefin (C 4 to 20) excluding ethylene (weight average molecular weight 5,000 to 100,000)] ; chlorinated paraffin; Ester [phthalic acid ester [diethyl phthalate (DEP), dibutyl phthalate (DBP), di-2-ethylhexyl phthalate (DOP), didecyl phthalate, dilauryl phthalate, distearyl phthalate, diisononyl phthalate, etc.], adipic acid esters [di(2-ethylhexyl)adipate (DOA), dioctyl adipate, etc.] and sebacate esters (dioctyl sebacate, etc.); Animal and plant oils and fats (linoleic acid, linolenic acid, etc.); and the hydrogenated substance of what has an unsaturated double bond which can be hydrogenated in these; Fatty acid ester (butyl stearate, 2-ethylhexyl palmitate, 2-ethylhexyl stearate, monoglyceride behenate, cetyl 2-ethylhexanoate, isopropyl palmitate, cholesteryl isostearate, palm fatty acid Methyl, methyl laurate, methyl oleate, methyl stearate, isopropyl myristate, octyldodecyl myristate, myristyl myristate, stearyl stearate, 2-ethylhexyl stearate, isotridecyl stearate , 2-ethylhexanoic acid triglyceride, butyl laurate, octyl oleate) and the like. A plasticizer may be used individually by 1 type, or may use 2 or more types together. The amount of the plasticizer to be used is preferably 100% by weight or less, more preferably 1 to 50% by weight, particularly preferably 3 to 40% by weight, particularly Preferably it is 5 to 35 weight%, Most preferably, it is 10 to 30 weight%.

Examples of the tackifier include terpene resins, terpene phenol resins, phenol resins, aromatic hydrocarbon-modified terpene resins, rosin resins, modified rosin resins, synthetic petroleum resins (aliphatic, aromatic or alicyclic synthetic petroleum resins, etc.), coumarone- Indene resin, xylene resin, styrene resin, dicyclopentadiene resin, and the hydrogenated substance of what has an unsaturated double bond which can be hydrogenated among these, etc. are mentioned. A tackifier may be used individually by 1 type, or may use 2 or more types together.

Among these, those having polarity from the viewpoint of adhesive strength are preferable, rosin resins, phenol resins, terpene phenol resins, xylene resins, and hydrogenated substances thereof are more preferable, and terpene phenol resins and hydrogenated substances thereof are particularly preferable. The amount of the tackifier used is preferably 100% by weight or less, more preferably 1 to 50% by weight, particularly preferably 3 to 40% by weight, from the viewpoint of adhesive strength and heat resistance, based on the weight of the one-component curable pressure-sensitive adhesive. , more preferably 5 to 35% by weight, and most preferably 10 to 30% by weight.

As fillers, carbonates (magnesium carbonate, calcium carbonate, etc.), sulfates (aluminum sulfate, calcium sulfate, barium sulfate, etc.), sulfites (calcium sulfite, etc.), molybdenum disulfide, silicates (aluminum silicate, calcium silicate, etc.), diatomaceous earth, silicate powder, talc, silica, zeolite, and the like. The said filler becomes like this. Preferably they are microparticles|fine-particles of about 0.01-5 micrometers in volume average particle diameter, and may use individually by 1 type, or may use 2 or more types together. The amount of the filler used is preferably 250 wt% or less, more preferably 0.5 to 100 wt%, from the viewpoint of the cohesive force of the pressure-sensitive adhesive based on the weight of the one-component curable pressure-sensitive adhesive.

As pigments, inorganic pigments (alumina white, graphite, titanium oxide, ultrafine titanium oxide, zinc oxide, black iron oxide, mica-like iron oxide, light white, white carbon, molybdenum white, carbon black, lisage, lithopone, barite, cadmium red , Cadmium Mercury Red, Bengal, Molybdenum Red, Podium, Yellow Lead, Cadmium Sulfur, Barium Sulfur, Strontium Sulfur, Titanium Sulfur, Titanium Black, Chromium Oxide Rust, Cobalt Oxide, Cobalt Rust, Cobalt Chrome Rust, Ultramarine Blue, Wire Blue, Cobalt Blue , cerulean blue, manganese purple, cobalt purple, etc.) and organic pigments (shellac, insoluble azo pigment, soluble azo pigment, condensed azo pigment, phthalocyanine blue, dyeing lake, etc.). The said pigment becomes like this. Preferably they are microparticles|fine-particles of about 0.01-5 micrometers in volume average particle diameter, and may use individually by 1 type, or may use 2 or more types together. Based on the weight of the 21-liquid curable pressure-sensitive adhesive, the amount of the pigment used is preferably 250% by weight or less from the viewpoint of the cohesive force of the pressure-sensitive adhesive, and more preferably 0.1 to 50% by weight.

Examples of the antistatic agent include polyether polyols, surfactants, metallic conductive fillers, carbon black, and quaternary ammonium salts having a weight average molecular weight of less than 5000.

As an antigelling agent (urethanization retarder), the compound represented by General formula (4) is mentioned.

The antigelling agent exhibits the effect of preventing gelation due to a side reaction at the time of urethanization, securing a pot life at the time of two-component curing, and shortening the curing time at the time of curing.

[Formula 3]

R ⁴ and R ⁵ in the general formula (4) each independently represent a hydrocarbon group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or a heterocyclic group having 3 to 5 carbon atoms.

An antigelling agent may be used individually by 1 type, or may use 2 or more types together.

Specific examples of the compound represented by the general formula (4) include β-diketone, β-ketoester, and malonic acid dialkyl ester.

As β-diketone, 2,4-pentanedione (acetylacetone), 3-methyl-2,4-pentanedione, 2,4-hexanedione, 2,2-dimethyl-3,5-hexanedione, 2 ,4-heptanedione, 3,5-heptanedione, 2,2,6,6-tetramethyl-3,5-heptanedione, 2,4-octanedione, 2,2,7-trimethyl-3,5- Octanedione, 2,4-nonanedione, 3-methyl-2,4-nonanedione, 2-methyl-4,6-nonanedione, 1-phenyl-1,3-butanedione (benzoylacetone), dibenzoylmethane and 2-furoylbenzoylmethane.

As β-ketoester, methyl acetoacetate, ethyl acetoacetate, propyl acetoacetate, butyl acetoacetate, methyl propionyl acetate, ethyl propionyl acetate, propyl propionyl acetate, isopropyl propionyl acetate, butyl propionyl acetate, buty methyl reyl acetate, ethyl butyryl acetate, propyl butyryl acetate, methyl caproyl acetate, ethyl caproyl acetate, propyl caproyl acetate, butyl caproyl acetate, etc. are mentioned.

As malonic acid dialkyl ester, dimethyl malonate, diethyl malonate, methyl ethyl malonate, diisopropyl malonate, dibutyl malonate, etc. are mentioned.

An antigelling agent may be used individually by 1 type, or may use 2 or more types together.

The amount of the antigelling agent to be used is appropriately selected depending on the desired reaction rate and pot life, but from the viewpoint of contamination to the adherend due to curing and bleed-out, preferably 0.01 to 1% by weight, based on the weight of the polyurethane resin, further Preferably it is 0.02 to 0.5 weight%, Especially preferably, it is 0.03 to 0.3 weight%.

There is no restriction|limiting in particular about the addition time of an additive, When manufacturing a polyurethane resin, you may add to a polyol component (A) beforehand, and you may add in arbitrary manufacturing processes of a polyurethane resin.

In the adhesive of the present invention, when the main agent is a polyurethane resin and it is a two-component curable adhesive, it is preferable to use a curing agent containing a crosslinking agent (D) having an active hydrogen group or an isocyanate group.

Examples of the crosslinking agent (D) having an active hydrogen group or an isocyanate group include a crosslinking agent (D1) having an active hydrogen group and a crosslinking agent (D2) having an isocyanate group.

When the polyurethane resin as a main subject has an isocyanate group, it is preferable to use the hardening|curing agent containing the crosslinking agent (D1) which has an active hydrogen group.

On the other hand, when the polyurethane resin as a main component has an active hydrogen group, it is preferable to use the hardening|curing agent containing the crosslinking agent (D2) which has an isocyanate group.

As the crosslinking agent (D1) having an active hydrogen group, the hydroxyl group-containing compound (a hydroxyl group-containing compound described as a compound having m active hydrogen atoms constituting the residue R ¹ ), the hydroxyl group-containing amine (C), the thiol (residue Thiol described as a compound having m active hydrogen atoms constituting R ¹ ), the polyoxyalkylene polyol (a1), the polyol (a2) and the other polyols (a3), and an isocyanate component (B) with them As a reaction product with the organic polyisocyanate exemplified as , a compound having an active hydrogen group at the terminal, etc. are exemplified.

Examples of the crosslinking agent (D2) having an isocyanate group include an isocyanate exemplified as the isocyanate component (B) and a compound having an isocyanate group at the terminal as a reaction product of the isocyanate exemplified as the crosslinking agent (D1) and the isocyanate exemplified as the isocyanate component (B). can

It is preferable that the number average functional group number of a crosslinking agent (D) is 2-6 or more from a sclerosing|hardenable viewpoint, More preferably, it is 2-5, Especially preferably, it is 3-4.

In the case of using the pressure-sensitive adhesive of the present invention as a two-component curable pressure-sensitive adhesive, the solvent, antioxidant, ultraviolet absorber, plasticizer, tackifier, filler, pigment, antistatic agent and gelation agent are further provided to the extent that the effect of the present invention is not impaired. It can contain additives, such as an inhibitor (urethanization retarder). Specifically, it is an additive described in the one-component curable urethane pressure-sensitive adhesive. The additive may be added to any of the main agent and the curing agent, or may be added at the time of mixing the main agent and the curing agent. desirable.

The NCO/OH ratio (ratio of the number of moles of isocyanate groups to the number of moles of hydroxyl groups) when mixing the main agent and the curing agent is preferably 0.01 to 2.0, more preferably from the viewpoint of the strength and adhesive strength of the cured product of the obtained pressure-sensitive adhesive It is 0.02-1.5, Especially preferably, it is 0.05-1.3.

Although the use of the adhesive of this invention is not specifically limited, For example, apply|coating to base films, such as a polyester film and a polyolefin film, and hardening to obtain an adhesive sheet, It can be bonded to an optical member, and can be used as a surface protection film etc.

The adhesive sheet using the adhesive of this invention and the optical member using the adhesive of this invention are also contained in this invention.

When manufacturing the pressure-sensitive adhesive sheet using the urethane prepolymer (P), the two-component curable pressure-sensitive adhesive, the two-component curable pressure-sensitive adhesive, and the pressure-sensitive adhesive sheet using the one-component curable pressure-sensitive adhesive, a urethanization catalyst can be used depending on the use and curability requirements.

As a urethanation catalyst, a metal catalyst, an amine catalyst, etc. are mentioned.

Examples of the metal catalyst include tin-based catalysts [trimethyltin laurate, trimethyltin hydroxide, dimethyltindilaurate, dibutyltindiacetate, dibutyltindilaurate, stannus octoate and dibutyltin maleate], lead-based catalysts Catalyst [lead oleate, lead 2-ethylhexanoate, lead naphthenate, lead octhenate, etc.], bismuth catalyst [beta-, such as salt of bismuth and monocarboxylic acid having 1 to 12 carbon atoms, bismuth alkoxide, and bismuth and acetylacetone chelate compound with diketone], titanium catalysts [isopropoxytriN-ethylaminoethylaminate titanium, tetrabutyl titanate and tetraisopropoxybisdioctylphosphite titanium, etc.], iron catalysts [iron carboxylate, etc.] carboxylate compounds (such as iron lactate and iron ricinolate), ferrocene-based compounds (such as ferrocene and acetylferrocene) and iron phthalocyanine] and other metal catalysts [metal salts of naphthenate such as cobalt naphthenate and phenylmercuric propionate] can be heard

Examples of the amine catalyst include triethylenediamine, tetramethylethylenediamine, diazabicycloalkene [1,8-diazabicyclo[5,4,0]undecene-7 [DBU (manufactured by San Apro Co., Ltd., registered trademark)] ], dialkyl (1 to 3 carbon atoms) aminoalkyl (2 to 4 carbon atoms) amine [dimethylaminoethylamine, dimethylaminopropylamine, diethylaminopropylamine, dipropylaminopropylamine, etc.], heterocyclic amino alkyl (C2-6) amine [2-(1-aziridinyl)ethylamine, 4-(1-piperidinyl)-2-hexylamine, etc.] and N-methyl and N-ethylmorpholine can

Among these, diazabicycloalkene, a bismuth catalyst, and a tin catalyst are preferable, and DBU, a salt of bismuth and a monocarboxylic acid having 1 to 12 carbon atoms, and dibutyltin dilaurate are more preferable.

The amount of the urethanization catalyst used varies depending on the application, but when high fast curing is required, preferably 5000 ppm or less, more preferably 1 to 3000 ppm, particularly preferably 10 based on the weight of the two-component curing type urethane pressure-sensitive adhesive. to 1000 ppm. A urethanation catalyst may be used individually by 1 type, or may use 2 or more types together.

As an optical member to which the pressure-sensitive adhesive and pressure-sensitive adhesive sheet are applied, a polarizing plate, a retardation plate, a light diffusion plate, an antireflection film, an electromagnetic wave shielding film, and a glass substrate used in liquid crystal displays, organic EL displays, plasma displays, field emission displays, etc. can be heard

The following method etc. are mentioned as a specific example of the method of forming an adhesive sheet.

A gravure coater, a reverse roll coater, a comma coater, a spin coater, a curtain coater, a slot coater, a bar coater, a die coater, or a knife coater can be used for coating the urethane pressure sensitive adhesive on the base film. The application amount (solid content) of the pressure-sensitive adhesive at the time of coating is preferably 0.5 to 300 g/m 2 , more preferably 1 to 200 g/m 2 , and particularly preferably 10 to 100 g/m 2 .

Preferably the coating temperature of the adhesive at the time of applying to a base film is 10-160 degreeC, More preferably, it is 25-120 degreeC from a viewpoint of coatability and thermal deterioration suppression, The viscosity of the adhesive in coating temperature is shaping|molding From the viewpoint of properties (thick coating can be applied and there is no appearance defects such as warpage and sink marks after curing) and coatability, preferably 0.01 to 100 Pa·s, more preferably 0.02 to 50 Pa·s, particularly preferred It is preferably 0.03 to 10 Pa·s.

A general dry laminator or an extrusion laminator is used for lamination. After lamination, an adhesive completely hardens by curing at 10-50 degreeC for 20-150 hours.

The storage modulus of the cured product of the pressure-sensitive adhesive of the present invention (hereinafter, denoted by G') is preferably 0.01 to 5 MPa at -30°C, more preferably 0.02 to 2 MPa, particularly preferably 0.05 to 1 MPa. and at 100°C, preferably 0.005 to 3 MPa, more preferably 0.01 to 1 MPa, and particularly preferably 0.05 to 0.5 MPa. The ratio of G' at -30 °C to G' at 100 °C [G' at -30 °C/100 G' at °C] is preferably 10 or less, more preferably 8 or less, particularly preferably preferably 5 or less, most preferably 3 or less.

When the ratio of G' at -30°C to 100°C is 10 or less, better adhesive force is obtained from a low temperature to a high temperature.

The storage elastic modulus G' in this specification is measured with the following method.

<Method for measuring storage modulus>

Measuring device: Rheogel-E4000 [manufactured by UBM Co., Ltd.]

Measuring Jig: Solid Shear

Measurement temperature: -50 ~ 180 ℃

Temperature increase rate: 5 ℃/min

Measurement frequency: 1 Hz

Example

Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited to these Examples.

The composition, preference, etc. of the raw material used in the Example are as follows.

<Polyol component>

(a1-1) The polyoxyalkylene polyol described in Production Example 1 below.

(a1-2) The polyoxyalkylene polyol described in Production Example 2 below.

(a1-3) The polyoxyalkylene polyol described in Production Example 3 below.

(a2-1) The polyoxyalkylene polyol described in Production Example 4 below.

(a1-4) The polyoxyalkylene polyol described in Production Example 5 below.

(a2-2) polypropylene glycol ["Sannix PP-1000" manufactured by Sanyo Chemical Industry Co., Ltd., primary hydroxyl group content = 2%, hydroxyl value 112 mgKOH/g, total unsaturation = 0.010 meq/g]

(a2-3) polypropylene glycol ["Sannix PP-2000" manufactured by Sanyo Chemical Industry Co., Ltd., primary hydroxyl group content = 2%, hydroxyl value 56 mgKOH/g, total unsaturation = 0.04 meq/g]

(a2-4) polypropylene glycol [Sanyo Chemical Industry Co., Ltd. "Sannix PP-4000", primary hydroxyl group content = 2%, hydroxyl value 28 mgKOH/g, total unsaturation = 0.12 meq/g]

(a2-5) PO/EO block adduct of propylene glycol ["Sannix PL-910" manufactured by Sanyo Chemical Industry Co., Ltd., primary hydroxyl group content = 2%, hydroxyl value 125 mgKOH/g, total unsaturation = 0.010 meq/g]

(a2-6) polytetramethylene ether glycol ["PTMG2000" manufactured by Mitsubishi Chemical Co., Ltd., hydroxyl value 56 mgKOH/g, total unsaturation = 0.000 meq/g]

(a2-7) Copolymer of tetrahydrofuran and methylated tetrahydrofuran ["PTGL-2000" manufactured by Hodogaya Chemical Co., Ltd., hydroxyl value 56 mgKOH/g, total unsaturation = 0.000 meq/g]

<isocyanate component>

(b1-1) HDI [Duranate 50M manufactured by Asahi Chemical Co., Ltd.]

<Amine>

(c1-1) monoethanolamine (hydroxyl value: 918 mgKOH/g, amine value: 918 mgKOH/g)

(c2-1) N-(2-aminoethyl)ethanolamine (hydroxyl value: 539 mgKOH/g, amine value: 1077 mgKOH/g)

(x1-1) isophorone diamine

(x1-2) hexamethylenediamine

(x1-3) poly(propylene glycol) diamine [Handman Japan Co., Ltd. “JEFFAMINE D-2000”]

(x1-4) n-butylamine

<crosslinking agent>

(d-1) isocyanurate form of HDI [Asahi Chemical Co., Ltd. product, Duranate TKA-100]

[Production of polyoxyalkylene polyol]

<Production Example 1>

1100 g of polyoxypropylene glycol (primary hydroxyl group content = 2%, hydroxyl value 204 mgKOH/g, total unsaturation = 0.004 meq/g) prepared by reacting PO in the presence of a KOH catalyst using propylene glycol as an initiator was stirred After putting in a stainless steel autoclave equipped with a device, a temperature control device, a heat exchanger as a condensation facility, a raw material supply line and an exhaust line, 0.09 g of tris(pentafluorophenyl)borane is injected, and the reaction temperature of PO is 70 to It was continuously added in the liquid phase while controlling to maintain 80 °C. When the amount of liquid in the autoclave reached 2000 ml, the input of PO was stopped, and after aging at 70°C for 4 hours, 200 g of water was added and heating was performed at 130-140°C for 1 hour. After heating for 1 hour, water was distilled off under atmospheric pressure for 2 hours, and then the remaining water and low boiling point compounds were distilled off under reduced pressure over 3 hours while continuously introducing steam while maintaining the pressure at 30 to 50 torr. After that, 30 g of synthetic silicate [Kyowa Chemical Industry Co., Ltd., "Kyoward 600"] and 40 g of water were added, stirred at 60 DEG C for 3 hours, taken out from the autoclave, and filtered through a 1 micron filter. After drying, it dehydrated and obtained polyoxyalkylene polyol (a1-1). The polyoxyalkylene polyol (a1-1) had a hydroxyl value of 112 mgKOH/g, a viscosity of 150 mPa·s/25°C, a primary hydroxyl group content of 71%, and a total degree of unsaturation of 0.004 meq/g.

<Production Example 2>

1300 g of polyoxypropylene glycol prepared by reacting PO in the presence of a KOH catalyst using propylene glycol as an initiator (primary hydroxyl group content = 2%, hydroxyl value 173 mgKOH/g, total unsaturation = 0.006 meq/g) was stirred After putting in a stainless steel autoclave equipped with a device, a temperature control device, a heat exchanger as a condensation facility, a raw material supply line and an exhaust line, 0.09 g of tris(pentafluorophenyl)borane is injected, and the reaction temperature of PO is 70 to It was continuously added in the liquid phase while controlling to maintain 80 °C. When the amount of liquid in the autoclave reached 2000 ml, the input of PO was stopped, and after aging at 70°C for 4 hours, 200 g of water was added and heating was performed at 130-140°C for 1 hour. After heating for 1 hour, water was distilled off under atmospheric pressure for 2 hours, and then the remaining water and low boiling point compounds were distilled off under reduced pressure over 3 hours while continuously introducing steam while maintaining the pressure at 30 to 50 torr. After that, 30 g of synthetic silicate [Kyowa Chemical Industry Co., Ltd., "Kyoward 600"] and 40 g of water were added, stirred at 60 DEG C for 3 hours, taken out from the autoclave, and filtered through a 1 micron filter. After drying, it dehydrated and obtained polyoxyalkylene polyol (a1-2). The polyoxyalkylene polyol (a1-2) had a hydroxyl value of 112 mgKOH/g, a viscosity of 150 mPa·s/25°C, a primary hydroxyl group content of 63%, and a total degree of unsaturation of 0.006 meq/g.

<Production Example 3>

1700 g of polyoxypropylene glycol (primary hydroxyl group content = 2%, hydroxyl value 132 mgKOH/g, total unsaturation level = 0.009 meq/g) prepared by reacting PO in the presence of a KOH catalyst using propylene glycol as an initiator was stirred After putting in a stainless steel autoclave equipped with a device, a temperature control device, a heat exchanger as a condensation facility, a raw material supply line and an exhaust line, 0.09 g of tris(pentafluorophenyl)borane is injected, and the reaction temperature of PO is 70 to It was continuously added in the liquid phase while controlling to maintain 80 °C. When the amount of liquid in the autoclave reached 2000 ml, input of PO was stopped, and after aging at 70°C for 4 hours, 200 g of water was added thereto, followed by heating at 130 to 140°C for 1 hour. After heating for 1 hour, water was distilled off under atmospheric pressure for 2 hours, and then the remaining water and low boiling point compounds were distilled off under reduced pressure over 3 hours while continuously introducing steam while maintaining the pressure at 30 to 50 torr. Thereafter, 30 g of synthetic silicate [Kyowa Chemical Industry Co., Ltd., "Kyoward 600"] and 40 g of water were added, stirred at 60° C. for 3 hours, taken out from the autoclave, and filtered through a 1 micron filter. After filtering, it dehydrated and obtained polyoxyalkylene polyol (a1-3). The polyoxyalkylene polyol (a1-3) had a hydroxyl value of 112 mgKOH/g, a viscosity of 150 mPa·s/25°C, a primary hydroxyl group content of 45%, and a total degree of unsaturation of 0.009 meq/g.

<Production Example 4>

1800 g of polyoxypropylene glycol (primary hydroxyl group content = 2%, hydroxyl value 125 mgKOH/g, total unsaturation = 0.011 meq/g) prepared by reacting PO in the presence of a KOH catalyst using propylene glycol as an initiator was stirred Put in a stainless steel autoclave equipped with a device, a temperature control device, a heat exchanger as a condensation facility, a raw material supply line and an exhaust line, and after 0.09 g of tris(pentafluorophenyl)borane is injected, the reaction temperature of PO is 70 to It was continuously added in the liquid phase while controlling to maintain 80 °C. When the amount of liquid in the autoclave reached 2000 ml, input of PO was stopped, and after aging at 70°C for 4 hours, 200 g of water was added thereto, followed by heating at 130 to 140°C for 1 hour. After heating for 1 hour, water was distilled off under atmospheric pressure for 2 hours, and then the remaining water and low-boiling point compounds were distilled off under reduced pressure over 3 hours while continuously introducing steam while maintaining the pressure at 30 to 50 torr. After that, 30 g of synthetic silicate [Kyowa Chemical Industry Co., Ltd., “Kyoward 600”] and 40 g of water were added, stirred at 60° C. for 3 hours, taken out from the autoclave, and filtered through a 1 micron filter. After filtration, it dehydrated and obtained polyoxyalkylene polyol (a2-1). The polyoxyalkylene polyol (a2-1) had a hydroxyl value of 112 mgKOH/g, a viscosity of 150 mPa·s/25°C, a primary hydroxyl group content of 35%, and a total degree of unsaturation of 0.011 meq/g.

<Production Example 5>

After injecting 116 g of propylene glycol and 0.09 g of tris(pentafluorophenyl)borane into a stainless steel autoclave equipped with a stirring device, a temperature control device, a heat exchanger as a condensation facility, a raw material supply line and an exhaust line, PO is reacted The liquid was continuously introduced while controlling the temperature to be maintained at 70 to 80°C. When the amount of liquid in the autoclave reached 2000 ml, input of PO was stopped, and after aging at 70°C for 4 hours, 200 g of water was added thereto, followed by heating at 130 to 140°C for 1 hour. After heating for 1 hour, water was distilled off under atmospheric pressure for 2 hours, and then the remaining water and low boiling point compounds were distilled off under reduced pressure over 3 hours while continuously introducing steam while maintaining the pressure at 30 to 50 torr. Thereafter, 30 g of synthetic silicate [Kyowa Chemical Industry Co., Ltd., "Kyoward 600"] and 40 g of water were added, stirred at 60° C. for 3 hours, taken out from the autoclave, and filtered through a 1 micron filter. After filtering, it dehydrated and obtained polyoxyalkylene polyol (a1-4). The polyoxyalkylene polyol (a1-4) had a hydroxyl value of 112 mgKOH/g, a viscosity of 150 mPa·s/25°C, a primary hydroxyl group content of 85%, and a total degree of unsaturation of 0.000 meq/g.

[Production of Urethane Prepolymer]

<Production Example 6>

100 parts by weight of the polyoxyalkylene polyol (a1-1) obtained in Production Example 1 and 21 parts by weight of HDI (b1-1) were added to a 4-neck flask equipped with a stirring bar and a thermometer, and reacted at 110° C. for 15 hours under a nitrogen stream. to obtain a urethane prepolymer (P-1).

<Production Examples 7 to 18>

Except having changed the raw material and compounding quantity as Table 1, it carried out similarly to manufacture example 6, and obtained urethane prepolymer (P-2) - (P-13).

<Example 1>

20 parts by weight of urethane prepolymer (P-1) and 50 parts by weight of ethyl acetate as a solvent were injected into a four-neck flask equipped with a stirring bar and a thermometer, and after uniform stirring, 0.021 parts by weight of monoethanolamine (c1-1); 0.3 parts by weight of N-(2-aminoethyl)ethanolamine (c2-1) and 0.12 parts by weight of isophoronediamine (x1-1) were added, and it was made to react while stirring at room temperature for 1 hour, to obtain a polyurethane resin solution. The weight average molecular weight of this polyurethane resin was 250,000, and the hydroxyl value of the polyurethane resin was 8.7 mgKOH/g. Subsequently, 0.1 parts by weight of the crosslinking agent (d-1) and 0.004 parts by weight of dibutyltin laurate as a catalyst are mixed with the obtained polyurethane resin solution, and the film thickness in terms of solid content is 30 μm to a 38 μm thick polyethylene terephthalate film. It was applied using a bar coater as much as possible. After drying at 120 degreeC for 3 minutes, it cured at 50 degreeC for 2 days, and the adhesive sheet using the adhesive containing a polyurethane resin was obtained.

<Examples 2 to 15, Comparative Examples 1 to 6>

Except having changed the urethane prepolymer, raw material, and compounding quantity as shown in Table 2, it carried out similarly to Example 1, and obtained the adhesive sheet using the adhesive containing a polyurethane resin solution and a polyurethane resin.

Table 2 shows the weight average molecular weight and hydroxyl value of the obtained polyurethane resin. In addition, in the urethane resin solution of Comparative Example 5, since the polyurethane resin gelled, an analysis and evaluation below were not performed.

(1) Method for measuring adhesion and low staining properties

The pressure-sensitive adhesive sheets obtained in Examples 1 to 15 and Comparative Examples 1 to 4 and 6 were cut to a size of 200 mm × 25 mm, and a stainless steel plate, glass plate, or PET sheet (Lumiror T60 manufactured by Toray Co., Ltd.) was used as an adherend. Bonding while crimping with a 2 kg roller, using a tensile tester (Autograph AG-IS, manufactured by Shimadzu Corporation), 180° peel strength (unit: N/ 25 mm) was measured. The measurement was performed about 5 samples, the average value was made into the value of adhesive force, and the following reference|standard evaluated adhesive force. Moreover, the to-be-adhered body after peeling of an adhesive sheet was observed visually, and the following reference|standard evaluated the low contamination with respect to a to-be-adhered body. These results are shown in Table 3.

<Adhesive force>

(double-circle): 180 degree peeling strength is 15 N/25 mm or more and 50 N/25 mm or less.

(circle): 180 degree peeling strength is 10 N/25 mm or more and less than 15 N/25 mm.

(triangle|delta): 180 degree peeling strength is 5 N/25 mm or more and less than 10 N/25 mm.

x: 180 degree peeling strength is less than 5 N/25 mm.

<Low pollution>

(circle): The adhesive does not remain on to-be-adhered body, and there is also no blurring.

(triangle|delta): The adhesive or blurring remains in a part of the part to which the adhesive of the to-be-adhered body was pasted.

x: The adhesive or blurring remains over the substantially entire surface of the part where the adhesive of the to-be-adhered body was pasted.

(2) Evaluation method of storage modulus

In the preparation of the pressure-sensitive adhesive sheets of Examples 1 to 15 and Comparative Examples 1 to 4 and 6, a polyethylene terephthalate film having a thickness of 38 µm was changed to an OPP film having a thickness of 100 µm, and the film thickness of 30 µm in terms of solid content was changed to 1000 µm. It produced similarly except that, and the adhesive was peeled off from the OPP film, and the hardened|cured material of the urethane adhesive with a film thickness of 1000 micrometers was obtained. The storage elastic modulus of the hardened|cured material of the obtained urethane adhesive was measured by the said method, and the following references|standards evaluated the viscoelasticity in -30 degreeC and 100 degreeC. The results are shown in Table 3.

<Viscoelasticity at -30°C>

(double-circle): G' is less than 0.5 Mpa at -30 degreeC.

(circle): In -30 degreeC, G' is 0.5 Mpa or more and less than 1.5 Mpa.

(triangle|delta): In -30 degreeC, G' is 1.5 Mpa or more and less than 2.5 Mpa.

x: G' is 2.5 Mpa or more in -30 degreeC.

<Viscoelasticity at 100°C>

(double-circle): G' is 0.1 Mpa or more in 100 degreeC.

(circle): In 100 degreeC, G' is 0.04 Mpa or more and less than 0.1 Mpa.

(triangle|delta): In 100 degreeC, G' is 0.02 MPa or more and less than 0.04 MPa.

x: It is less than G'0.02 MPa in 100 degreeC.

(3) Evaluation method of breaking strength and breaking elongation of a cured adhesive product

In the preparation of the pressure-sensitive adhesive sheets of Examples 1 to 15 and Comparative Examples 1 to 4 and 6, a polyethylene terephthalate film having a thickness of 38 μm was applied to an OPP film having a thickness of 100 μm, and the film thickness of 30 μm in terms of solid content was changed to 100 μm. It produced similarly except that, and the adhesive was peeled off from the OPP film, and the hardened|cured material of the urethane adhesive with a film thickness of 100 micrometers was obtained. A dumbbell-shaped No. 3 test piece was produced from the obtained hardened|cured material of the urethane adhesive, and the breaking strength and breaking elongation were measured under the conditions of 100 mm/min of tensile speed in the environment of 23 degreeC 50%RH using the tensile tester. The measurement was performed about 5 test pieces, the average value was computed, and the following criteria evaluated the breaking strength and breaking elongation. The results are shown in Table 3.

<breaking strength>

(double-circle): It is 2 MPa or more.

○: 1 MPa or more and less than 2 MPa.

(triangle|delta): 0.5 MPa or more and less than 1 MPa.

x: It is less than 0.5 MPa.

<Elongation at break>

(double-circle): It is 1000 % or more.

(circle): 500 % or more and less than 1000 %.

(triangle|delta): 200 % or more and less than 500 %.

x: It is less than 200 %.

From the evaluation results in Table 3, the urethane pressure-sensitive adhesive of Examples has less fear of gelation when manufacturing a polyurethane resin compared to the pressure-sensitive adhesive of Comparative Examples, enables stable molecular weight control, and has a low storage elastic modulus at -30 ° C. Because the elastic modulus decrease at 100 ° C is small, it can be used at a wide temperature range, and exhibits high adhesive force to any of PET sheet, stainless steel plate and glass plate, and the breaking strength and breaking elongation of the adhesive film are also improved. It turns out that there is also little contamination of a complex.

Industrial Applicability

The urethane adhesive of this invention is an adhesive for bonding various optical members, such as a polarizing plate, retardation plate, and a light-diffusion plate, and a glass substrate, Various image display devices, such as a liquid crystal display, an organic electroluminescent display, a plasma display, and a field emission display, etc. , it is very useful because it can be used for a wide range of applications.

Claims (10)

A pressure-sensitive adhesive comprising a polyurethane resin comprising an amino group-free polyol component (A) and an isocyanate component (B) as essential constituent monomers,
The weight average molecular weight of the said polyurethane resin is 50,000-2 million, and the polyol component (A) which does not have the said amino group contains polyoxyalkylene polyol (a1),
The molecular terminal of the polyoxyalkylene polyol (a1) is a hydroxypropyl group, and the primary hydroxyl group content is at least 40%;
The adhesive whose 180 degree peeling strength on the conditions of 300 mm/min of tensile rate in 23 degreeC when bonding together crimping|bonding with a 2 kg roller to a glass plate is 5-50 N/25 mm. The method of claim 1,
The total degree of unsaturation of the polyoxyalkylene polyol (a1) is 0.010 meq/g or less, and the total degree of total unsaturation of all polyol components contained in the polyol component (A) not having an amino group is 0.025 meq/g or less. 3. The method of claim 1 or 2,
The polyurethane resin further contains an amine (C) having a hydroxyl group as a constituent monomer, the hydroxyl value of the amine (C) having a hydroxyl group is 50 to 1200 mgKOH/g, and the amine value is 50 to 1200 mgKOH/g adhesive. 4. The method of claim 3,
As the hydroxyl group-containing amine (C), the hydroxyl group-containing monoamine (c1) and the hydroxyl group-containing diamine (c2) are contained, and the content of the hydroxyl group-containing monoamine (c1) is the hydroxyl group-containing amine ( It is 0.5 to 50 weight% based on the total weight of C), Content of the diamine (c2) which has the said hydroxyl group is 50 to 99.5 weight% based on the total weight of the said amine (C) which has a hydroxyl group. 5. The method according to claim 3 or 4,
A chain extender comprising a urethane prepolymer (P) in which the polyurethane resin is obtained by reacting the polyol component (A) having no amino group and the isocyanate component (B), and an amine (C) having a hydroxyl group ( X), wherein the amine (C) having a hydroxyl group is a mixture containing the monoamine (c1) having a hydroxyl group and the diamine (c2) having a hydroxyl group, and the monoamine (c1) having a hydroxyl group The adhesive whose sum total of content and content of the diamine (c2) which has the said hydroxyl group is 5 to 100 weight% based on the total weight of the said chain extender (X). 6. The method according to any one of claims 1 to 5,
An adhesive having a hydroxyl value of 1 to 50 mgKOH/g of the polyurethane resin. 7. The method according to any one of claims 1 to 6,
A one-component curing type adhesive. 7. The method according to any one of claims 1 to 6,
The main subject is the polyurethane resin, and the adhesive is a two-component curing type adhesive. The adhesive sheet using the adhesive in any one of Claims 1-8. The optical member using the adhesive in any one of Claims 1-8.