Adhesive composition, cured product and laminate

Abstract

To provide an adhesive composition which gives a cured product and an adhesive sheet having low dielectric properties and high transparency and showing excellent adhesion to various base materials such as a difficult-to-adhere base material.SOLUTION: There are provided an adhesive composition, a cured product and a laminate, the adhesive composition containing a polyester resin (A) which is a reaction product of a polycarboxylic acid (a1) including a polycarboxylic acid containing an aromatic and / or a heterocyclic ring (a1-1) and a polyol (a2) consisting of a polyolefin polyol (a2-1) having a hydroxyl value of 10 mgKOH / g or more and less than 100 mgKOH / g, a polyol (a2-2) having a hydroxyl value of 100 mgKOH / g or more and less than 500 mgKOH / g and a polyol (a2-3) having a hydroxyl value of 500 mgKOH / g or more and 2000 mgKOH / g or less and satisfies specific formulas (1) and (2) and a polyisocyanate (B).SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a pressure-sensitive adhesive composition, a cured product, and a laminate. [Background technology]

[0002] Polyester resins are excellent in heat resistance, chemical resistance, durability, etc., and are widely used in applications such as films, electronic components, PET bottles, adhesives, etc. In addition, polyester resins have high polarity due to their structure, and are known to exhibit excellent adhesion to highly polar plastic films such as polyimide and polyester, and metals such as copper and aluminum.

[0003] In recent years, in laminating components such as transparent film antennas and radio wave reflective sheets, the components are sometimes bonded together using a transparent adhesive or adhesive sheet.

[0004] As such a pressure-sensitive adhesive composition, for example, a polyester-based pressure-sensitive adhesive composition containing a polyester resin having a unit derived from a hydrogenated polybutadiene structure and an aromatic ring structure is known (Patent Document 1). However, although this composition shows excellent adhesion to olefin substrates, it has poor adhesion to difficult-to-adhere substrates such as cycloolefin polymers (COPs). In addition, in recent years, with the increasing frequency of transmission signals, pressure-sensitive adhesive compositions for this application are also required to have low dielectric properties (low dielectric constant, low dielectric loss tangent), but this has not been taken into consideration in the technology. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2020-041137 A Summary of the Invention [Problem to be solved by the invention]

[0006] An object of the present invention is to provide an adhesive composition that gives a cured product and an adhesive sheet having low dielectric properties, high transparency, and excellent adhesiveness to various substrates such as hard-to-adhere substrates. [Means for Solving the Problems]

[0007] As a result of intensive studies, the present inventors have found a solution to the above problems and completed the present invention. That is, the present invention relates to the following adhesive composition, cured product, and laminate.

[0008] 1. A polyester resin (A) which is a reaction product of a polycarboxylic acid (a1) containing a polycarboxylic acid (a1-1) having an aromatic ring and / or a heterocyclic ring, and a polyol (a2) composed of a polyolefin polyol (a2-1) having a hydroxyl value of 10 mgKOH / g or more and less than 100 mgKOH / g, a polyol (a2-2) having a hydroxyl value of 100 mgKOH / g or more and less than 500 mgKOH / g, and a polyol (a2-3) having a hydroxyl value of 500 mgKOH / g or more and 2000 mgKOH / g or less, and satisfies the formulas (1) and (2), and an adhesive composition containing a polyisocyanate (B). (Formula 1) 0.8 ≦ w ≦ 1 (In Formula 1, w represents the molar fraction of the aromatic polycarboxylic acid and / or the polycarboxylic acid having a heterocyclic ring contained in the polycarboxylic acid (a1).) (Formula 2) 0 < x ≦ 0.5, 0 < y < 0.74, and z > 0.1 (In Formula 2, x represents the molar fraction of the (a2-1) component contained in the polyol (a2), y represents the molar fraction of the (a2-2) component contained in the polyol (a2), z represents the molar fraction of the (a2-3) component contained in the polyol (a2), and x + y + z = 1.)

[0009] 2. The adhesive composition according to the above item 1, wherein the (a2-2) component contains a dimer diol.

[0010] 3. The pressure-sensitive adhesive composition according to item 1 or 2 above, wherein the component (a2-3) contains an alkanediol and / or an alkylalkanediol.

[0011] 4. The pressure-sensitive adhesive composition according to item 1 or 2 above, wherein the component (B) comprises at least one member selected from the group consisting of an aliphatic polyisocyanate, an alicyclic polyisocyanate, a nurate form of an aliphatic polyisocyanate, and a nurate form of an alicyclic polyisocyanate.

[0012] 5. The pressure-sensitive adhesive composition according to item 1 or 2 above, further comprising a hydrogenated petroleum resin (C).

[0013] 6. A cured product of the pressure-sensitive adhesive composition described in the preceding item 1.

[0014] 7. A laminate having the cured product described in item 6 above on at least one surface of a substrate. Effect of the Invention

[0015] The pressure-sensitive adhesive composition of the present invention gives a cured product and a pressure-sensitive adhesive sheet which have low dielectric properties and high transparency, and also exhibit excellent adhesion to various substrates including poorly adherent substrates. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] The pressure-sensitive adhesive composition of the present invention comprises a polycarboxylic acid (a1) (hereinafter referred to as polycarboxylic acid (a1)) containing a polycarboxylic acid (a1-1) (hereinafter referred to as component (a1-1)) having an aromatic ring and / or a heterocyclic ring, A polyolefin polyol (a2-1) having a hydroxyl value of 10 mgKOH / g or more and less than 100 mgKOH / g (hereinafter referred to as component (a2-1)), A polyol (a2-2) having a hydroxyl value of 100 mgKOH / g or more and less than 500 mgKOH / g (hereinafter referred to as component (a2-2)), and a polyester resin (A) which is a reaction product of a polyol (a2) (hereinafter referred to as polyol (a2)) consisting of a polyol (a2-3) (hereinafter referred to as component (a2-3)) having a hydroxyl value of 500 mgKOH / g or more and 2000 mgKOH / g or less; and a polyisocyanate (B).

[0017] <About polyester resin (A)> The polyester resin (A) is a reaction product of a polycarboxylic acid (a1) and a polyol (a2).

[0018] The polycarboxylic acid (a1) essentially contains the component (a1-1). By using the component (a1-1) as a reactive component, the cured product of the pressure-sensitive adhesive composition (hereinafter simply referred to as the "cured product") tends to have low dielectric properties.

[0019] Among the components (a1-1), examples of the polycarboxylic acids having an aromatic ring include dicarboxylic acids having an aromatic ring, such as phthalic acid, phthalic anhydride, isophthalic acid, terephthalic acid, diphenylmethane-4,4'-dicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 1,8-naphthalenedicarboxylic acid, 2,3-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 1,8-naphthalenedicarboxylic acid anhydride, and 2,3-naphthalenedicarboxylic acid anhydride; Tricarboxylic acids having an aromatic ring, such as trimellitic acid, trimellitic anhydride, 1,2,3-benzenetricarboxylic acid, and 1,3,5-benzenetricarboxylic acid; tetracarboxylic acids having an aromatic ring, such as 1,2,4,5-benzenetetracarboxylic acid (pyromellitic acid), 1,2,4,5-benzenetetracarboxylic dianhydride (pyromellitic dianhydride), 2,3,6,7-naphthalenetetracarboxylic acid, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 9,9-bis(3,4-dicarboxyphenyl)fluorene, and 9,9-bis(3,4-dicarboxyphenyl)fluorene dianhydride; Examples of the esters include esters of these carboxylic acids (monoesters, diesters, triesters, tetraesters), etc. These may be used alone or in combination of two or more.

[0020] Among the (a1-1) components, examples of the polycarboxylic acid having a heterocycle include dicarboxylic acids having an oxygen atom in the ring, such as 2,4-furandicarboxylic acid, 2,5-furandicarboxylic acid, and 1,4-dioxane-2,5-dicarboxylic acid; dicarboxylic acids having a nitrogen atom in the ring, such as 2,3-piperidinedicarboxylic acid, 2,3-piperidinedicarboxylic acid anhydride, 2,4-piperidinedicarboxylic acid, 2,5-piperidinedicarboxylic acid, 2,6-piperidinedicarboxylic acid, 2,3-pyridinedicarboxylic acid, 2,3-pyridinedicarboxylic acid anhydride, 2,4-pyridinedicarboxylic acid, 2,5-pyridinedicarboxylic acid, 2,6-pyridinedicarboxylic acid, and imidazole-4,5-dicarboxylic acid; and esters (monoesters, diesters) of the above-mentioned carboxylic acids. These may be used alone or in combination of two or more.

[0021] Among these, from the viewpoint of the tendency of the cured product to have low dielectric properties, preferred are dicarboxylic acids having an aromatic ring and dicarboxylic acids having an oxygen atom in the ring, more preferred are dicarboxylic acids having an aromatic ring, and even more preferred are one or more selected from phthalic acid, phthalic anhydride, isophthalic acid, terephthalic acid, 2,6-naphthalenedicarboxylic acid, and diesters of these carboxylic acids.

[0022] The molar fraction of the (a1-1) component contained in the polycarboxylic acid (a1) satisfies (Formula 1): 0.8≦w≦1 (w represents the molar fraction of the (a1-1) component contained in the polycarboxylic acid (a1). When w satisfies this range, the cured product tends to have a low dielectric tangent. From the same viewpoint, the molar fraction w is preferably 0.9≦w≦1, and more preferably 0.95≦w≦1.

[0023] As the polycarboxylic acid (a1), a polycarboxylic acid (a1-2) (hereinafter referred to as component (a1-2)) other than the component (a1-1) can also be used.

[0024] Examples of the component (a1-2) include aliphatic dicarboxylic acids such as oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, azelaic acid, pimelic acid, suberic acid, sebacic acid, undecanoic acid, dodecanedioic acid, tridecanedioic acid, and hydrogenated dimer acid; Alicyclic dicarboxylic acids such as hexahydrophthalic acid, hexahydrophthalic anhydride, 1,3-cyclohexanedicarboxylic acid, and 1,4-cyclohexanedicarboxylic acid; Unsaturated aliphatic dicarboxylic acids such as fumaric acid, maleic acid, maleic anhydride, itaconic acid, and dimer acid; Aliphatic tricarboxylic acids such as 1,2,3-propanetricarboxylic acid and 1,3,5-pentanetricarboxylic acid; Alicyclic tricarboxylic acids such as cyclohexane-1,2,4-tricarboxylic acid, cyclohexane-1,2,4-tricarboxylic anhydride, and cyclohexane-1,3,5-tricarboxylic acid; Examples of the esters include esters of these carboxylic acids (monoesters, diesters, triesters), etc. These may be used alone or in combination of two or more.

[0025] The molar fraction of the (a1-2) component contained in the polycarboxylic acid (a1) is preferably less than 0.2, more preferably less than 0.1, and even more preferably less than 0.05.

[0026] Polyol (a2) consists of components (a2-1), (a2-2) and (a2-3). By using these as reactive components, the cured product has low dielectric properties and high transparency, and also exhibits excellent adhesive strength. The hydroxyl value of each polyol is a value calculated from the following formula A using the molecular weight of potassium hydroxide, the number of hydroxyl groups in the polyol and the molecular weight of the polyol. (Formula A) (Hydroxyl value of polyol) = {(molecular weight of potassium hydroxide (56.11)) × 1000 × (number of hydroxyl groups in polyol)} / (molecular weight of polyol)

[0027] The component (a2-1) is a polyolefin polyol having a hydroxyl value of 10 mgKOH / g or more and less than 100 mgKOH / g.

[0028] Examples of the (a2-1) component include polybutadiene polyol, polyisoprene polyol, polyhexadiene polyol, hydrogenated polybutadiene polyol, hydrogenated polyisoprene polyol, and hydrogenated polyhexadiene polyol. These may be used alone or in combination of two or more. Commercially available products include "NISSO-PB G-1000", "NISSO-PB G-2000", "NISSO-PB G-3000", "NISSO-PB GI-1000", "NISSO-PB GI-2000", and "NISSO-PB GI-3000" (all manufactured by Nippon Soda Co., Ltd.), "Poly bd", "Poly ip", and "EPOL" (all manufactured by Idemitsu Kosan Co., Ltd.).

[0029] Among these, hydrogenated polybutadiene polyol and hydrogenated polyisoprene polyol are preferred from the viewpoint of suppressing gelation during production of the polyester resin (A).

[0030] The component (a2-2) is a polyol having a hydroxyl value of 100 mgKOH / g or more and less than 500 mgKOH / g.

[0031] Examples of the component (a2-2) include dimer diol, hydrogenated dimer diol (commercially available products include "Pripol 2033" (manufactured by Equus Japan Ltd.) and "SOVERMOL 908" (manufactured by BASF)), castor oil polyol (commercially available products include "YH403" (manufactured by Ito Oil Mills Ltd.)), polyethylene glycol (commercially available products include "PEG300", "PEG400", "PEG600", "PEG1000", and "PEG1500" (all manufactured by Sanyo Chemical Industries, Ltd.)), and polypropylene glycol (commercially available products include Examples of such polypropylene triols include "Sannix PP-400", "Sannix PP-600", "Sannix PP-950", and "Sannix PP-1000" (all manufactured by Sanyo Chemical Industries, Ltd.), polypropylene triols (commercially available products include "Sannix GP-400", "Sannix GP-600", "Sannix GP-1000", and "Sannix GP-1500" (all manufactured by Sanyo Chemical Industries, Ltd.), 1,12-octadecanediol, an ethylene oxide adduct of bisphenol A, and an ethylene oxide adduct of hydrogenated bisphenol A. These may be used alone or in combination of two or more.

[0032] Among these, dimer diol and hydrogenated dimer diol are preferred because they are easily miscible with the (a2-1) and (a2-3) components, and hydrogenated dimer diol is more preferred because it prevents gelation during the production of the polyester resin (A).

[0033] The component (a2-3) is a polyol having a hydroxyl value of 500 mgKOH / g or more and 2000 mgKOH / g or less.

[0034] Examples of the component (a2-3) include alkanediols such as ethylene glycol, diethylene glycol, triethylene glycol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, and 1,10-decanediol; Alkylalkanediols such as neopentyl glycol, 1,2-propanediol (propylene glycol), 2-methyl-1,3-propanediol, butylethylpropanediol, 3-methyl-1,5-pentanediol; Alkanetriols such as trimethylolethane, trimethylolpropane, glycerin, 1,2,4-butanetriol, 1,2,6-hexanetriol; Tetraols such as pentaerythritol, diglycerin; Cycloalkanediols such as 1,2-cyclohexanediol, 1,3-cyclohexanediol, 1,4-cyclohexanediol, 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol; Aryldiols such as catechol, xylylene glycol and the like can be mentioned. These may be used alone or in combination of two or more.

[0035] Among them, alkanediols and alkylalkanediols are preferable, and alkylalkanediols are more preferable because the cured product is likely to have low dielectric characteristics and is also likely to exhibit high adhesive strength.

[0036] The molar fractions of the (a2-1) component, (a2-2) component, and (a2-3) component contained in the polyol (a2) satisfy the following formula 2. (Formula 2) 0 < x ≦ 0.5, 0 < y < 0.74, and z > 0.1 (In Formula 2, x represents the molar fraction of the (a2-1) component contained in the polyol (a2), y represents the molar fraction of the (a2-2) component contained in the polyol (a2), z represents the molar fraction of the (a2-3) component contained in the polyol (a2), and x + y + z = 1.)

[0037] When the molar fraction (x) of the component (a2-1) satisfies 0 < x ≤ 0.5 (exceeding 0 and being 0.5 or less), the cured product is likely to have low dielectric characteristics. Also, since the cohesive force of the cured product can be maintained, no glue residue is observed when the adhesive layer (layer of the cured product) is peeled off from the base material. Also, from the same point, the molar fraction (x) is preferably 0.1 ≤ x ≤ 0.5, and more preferably 0.15 ≤ x ≤ 0.4.

[0038] When the molar fraction (y) of the component (a2-2) satisfies 0 < y < 0.74 (exceeding 0 and being less than 0.74), it becomes easy to be well compatible with the components (a2-1) and (a2-3), and the cured product is likely to exhibit high transparency. Also, from the same point, the molar fraction (y) is preferably 0.2 ≤ y < 0.74, and more preferably 0.3 ≤ y < 0.74.

[0039] When the molar fraction (z) of the component (a2-3) satisfies z > 0.1 (exceeding 0.1), the cohesive force of the cured product is likely to be exhibited. On the other hand, if z is too high, the molar fraction of the component (a2-1) and / or (a2-2) becomes relatively low, and there is a risk of impairing the low dielectric characteristics. Therefore, the molar fraction (z) is preferably 0.1 < z ≤ 0.5, and more preferably 0.15 ≤ z ≤ 0.4.

[0040] The polyester resin (A) is obtained by reacting the components (a1) and (a2). These components may be reacted all at once or sequentially. Also, as the reaction conditions, for example, the temperature is usually 150 to 270 °C, preferably 150 to 250 °C. Also, regarding the reaction time, it can be freely set as long as the reaction proceeds sufficiently and the polyester resin (A) is obtained.

[0041] As the usage amounts of the components (a1) and (a2), in order to make it easy to react with the polyisocyanate (B) described later with the hydroxy group at the molecular end of the polyester resin (A), the total molar ratio of the components (a1) and (a2) is set to 100 mol%, and (a1) component / (a2) component = 25 / 75 to 50 / 50 is preferable, and 33 / 67 to 45 / 55 is more preferable.

[0042] In the reaction, for example, a catalyst such as zinc acetate, tetrabutyl titanate, antimony trioxide, dibutyltin oxide, etc.; an organic solvent as described below, etc. may be used.

[0043] As for the physical properties of the polyester resin (A) obtained by the reaction, for example, the glass transition temperature (Tg) is preferably from −70 to 0° C., more preferably from −60 to −10° C., and even more preferably from −50 to −20° C., since the cured product is likely to exhibit excellent adhesive strength. The glass transition temperature (Tg) of the polyester resin (A) refers to a value measured with a commercially available differential scanning calorimeter (DSC).

[0044] The hydroxyl value of the polyester resin (A) is preferably 2 to 50 mgKOH / g, more preferably 2 to 30 mgKOH / g, and even more preferably 2 to 20 mgKOH / g, since the cured product is likely to have low dielectric properties. The hydroxyl value of the polyester resin (A) is a value measured in accordance with JIS K-0070.

[0045] Furthermore, the number average molecular weight of the polyester resin (A) is preferably 5,000 to 100,000, more preferably 7,000 to 50,000, and even more preferably 10,000 to 30,000, in that the cured product is likely to have low dielectric properties and exhibit excellent adhesive strength. The number average molecular weight of the polyester resin (A) refers to a polystyrene-equivalent value measured by gel permeation chromatography (GPC method).

[0046] Polyisocyanate (B) is a compound that has two or more isocyanate groups in the molecule. When component (B) is added, the hydroxyl groups at the molecular terminals of polyester resin (A) are consumed through a reaction, making the cured product more likely to have low dielectric properties and more likely to express cohesive strength.

[0047] Examples of the polyisocyanate (B) include aliphatic polyisocyanates such as methylene diisocyanate, butane-1,4-diisocyanate, hexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, and dimer diisocyanate in which the carboxyl group of a dimer acid is substituted with an isocyanate group; Alicyclic polyisocyanates such as cyclohexane-1,2-diisocyanate, cyclohexane-1,3-diisocyanate, cyclohexane-1,4-diisocyanate, isophorone diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, 1,2-di(isocyanatemethyl)cyclohexane (hydrogenated o-xylylene diisocyanate), 1,3-di(isocyanatemethyl)cyclohexane (hydrogenated m-xylylene diisocyanate), 1,4-di(isocyanatemethyl)cyclohexane (hydrogenated p-xylylene diisocyanate, methylcyclohexane diisocyanate, etc.; Aromatic polyisocyanates such as 4,4'-diphenylmethane diisocyanate, 4,4'-diphenyldimethylmethane diisocyanate, 4,4'-diphenyltetramethylmethane diisocyanate, 1,4-phenylene diisocyanate, tolylene diisocyanate, 1,2-di(isocyanatomethyl)benzene (o-xylylene diisocyanate), 1,3-di(isocyanatomethyl)benzene (m-xylylene diisocyanate), 1,4-di(isocyanatomethyl)benzene (p-xylylene diisocyanate), m-tetramethylxylylene diisocyanate, 1,5-naphthylene diisocyanate, 4,4'-dibenzyl isocyanate, and 1,3-phenylene diisocyanate; Examples include amino acid polyisocyanates such as lysine diisocyanate. As the polyisocyanate (B), nurates, adducts, biurets and allophanates of the above polyisocyanates can also be used, either alone or in combination of two or more.

[0048] Among these, from the viewpoint of the cured product being likely to have low dielectric properties and to exhibit excellent adhesive strength, one or more selected from the group consisting of aliphatic polyisocyanates, alicyclic polyisocyanates, nurate forms of aliphatic polyisocyanates, and nurate forms of alicyclic polyisocyanates are preferred, and one or more selected from the group consisting of hexamethylene diisocyanate, 1,3-di(isocyanatemethyl)cyclohexane (hydrogenated m-xylylene diisocyanate), dicyclohexylmethane-4,4'-diisocyanate, nurate forms of hexamethylene diisocyanate, and nurate forms of 1,3-di(isocyanatemethyl)cyclohexane (hydrogenated m-xylylene diisocyanate) are more preferred.

[0049] The content of polyisocyanate (B) is preferably 0.1 to 20 parts by weight, more preferably 0.5 to 10 parts by weight, and even more preferably 1 to 7 parts by weight, based on the non-volatile weight of 100 parts by weight of polyester resin (A), because the cured product is likely to have low dielectric properties and to exhibit excellent adhesive strength.

[0050] The pressure-sensitive adhesive composition of the present invention may contain a curing agent (B') other than the polyisocyanate (B) (hereinafter referred to as curing agent (B')).

[0051] Examples of the curing agent (B') include amino resins and phenol resins.

[0052] Examples of amino resins include melamine resins, guanamine resins, urea resins, etc., and specific examples of each resin are as described in JP-A-2019-131799. These may be used alone or in combination of two or more.

[0053] Examples of the phenol resin include resol type phenol resin, novolac type phenol resin, etc. These may be used alone or in combination of two or more kinds.

[0054] The content of the curing agent (B') is preferably 5 parts by weight or less, and more preferably 3 parts by weight or less, based on 100 parts by weight of the polyester resin (A) in terms of non-volatile weight.

[0055] The pressure-sensitive adhesive composition of the present invention may contain a hydrogenated petroleum resin (C). When the pressure-sensitive adhesive composition contains a hydrogenated petroleum resin (C), the cured product tends to have low dielectric properties and tends to exhibit excellent adhesive strength.

[0056] Hydrogenated petroleum resins are resins obtained by subjecting petroleum resins to a hydrogenation reaction, and are classified into fully hydrogenated petroleum resins and partially hydrogenated petroleum resins depending on the degree of hydrogenation.

[0057] Examples of the petroleum resin include C5 petroleum resin, C9 petroleum resin, and C5 / C9 petroleum resin. These may be used alone or in combination of two or more.

[0058] C5 petroleum resins are petroleum resins obtained from the C5 fraction of naphtha, and examples of the C5 fraction include cyclopentadiene, pentene, pentadiene, and isoprene. C9 petroleum resins are petroleum resins obtained from the C9 fraction of naphtha, and examples of the C9 fraction include indene, methylindene, vinyltoluene, styrene, α-methylstyrene, and β-methylstyrene. The C5 / C9 petroleum resin is a petroleum resin obtained from the C5 fraction and the C9 fraction. In addition, these petroleum resins may also contain olefins such as coumarone, dicyclopentadiene, butene, pentene, hexene, heptene, octene, butadiene, pentadiene, cyclopentadiene, octadiene, etc. These olefins may be used alone or in combination of two or more.

[0059] The petroleum resin is obtained by cationic polymerization of the above-mentioned fraction as a raw material in the presence of a Friedel-Crafts catalyst such as aluminum chloride or boron trifluoride. The obtained cationic polymer is hydrogenated in the presence of various known hydrogenation catalysts to obtain a hydrogenated petroleum resin (C).

[0060] Examples of the hydrogenation catalyst include metals such as nickel, palladium, cobalt, ruthenium, platinum, and rhodium; and oxides of these metals. The hydrogenation conditions are usually a temperature of 200 to 300° C. and a pressure of 10 to 300 kg / cm. 2 It is.

[0061] Commercially available hydrogenated petroleum resins include, for example, the "Arcon P Series" and "Arcon M Series" (both manufactured by Arakawa Chemical Industries, Ltd.), the "Imarv S Series" and "Imarv P Series" (both manufactured by Idemitsu Kosan Co., Ltd.), the "T-REZ R Series" and "T-REZ H Series" (both manufactured by ENEOS Corporation), etc. These may be used alone or in combination of two or more kinds.

[0062] The content of the hydrogenated petroleum resin (C) is preferably 5 to 100 parts by weight, more preferably 10 to 80 parts by weight, and even more preferably 20 to 60 parts by weight, based on the non-volatile weight of 100 parts by weight of the polyester resin (A), because the cured product is likely to have low dielectric properties and to exhibit excellent adhesive strength.

[0063] The pressure-sensitive adhesive composition of the present invention may further contain a curing catalyst (D). Examples of the curing catalyst (D) include organic sulfonic acids such as paratoluenesulfonic acid, dodecylbenzenesulfonic acid, dinonylnaphthalenesulfonic acid, polystyrenesulfonic acid, and dinonylnaphthalenesulfonic acid; inorganic acids such as hydrochloric acid, nitric acid, sulfuric acid, and phosphoric acid; organic acids such as acetic acid, propionic acid, oxalic acid, succinic acid, citric acid, lactic acid, and glycolic acid; and alkyl tin esters such as tin octylate, dibutyltin (2-ethylhexanoate), dioctyltin (2-ethylhexanoate), dioctyltin diacetate, dioctyltin dilaurate, dibutyltin oxide, dioctyltin oxide, dibutyltin dioctate, and monobutyltin trioctate. These may be used alone or in combination of two or more.

[0064] The content of the curing catalyst (D) is preferably 0 to 2 parts by weight, more preferably 0.005 to 1 part by weight, and even more preferably 0.01 to 0.5 part by weight, based on 100 parts by weight of the polyester resin (A) in terms of non-volatile weight.

[0065] The pressure-sensitive adhesive composition of the present invention may further contain an organic solvent (E).

[0066] Examples of the organic solvent (E) include aromatic hydrocarbons such as T-SOL100, T-SOL150 (both manufactured by ENEOS Corporation), toluene, and xylene; aliphatic hydrocarbons such as hexane, heptane, octane, and decane; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; esters such as methyl acetate, ethyl acetate, isopropyl acetate, butyl acetate, amyl acetate, ethyl formate, butyl propionate, methoxypropyl acetate, methyl cellosolve acetate, cellosolve acetate, ethyl cellosolve, and butyl cellosolve; and ethers such as dioxane and tetrahydrofuran. These may be used alone or in combination of two or more.

[0067] The content of the organic solvent (E) is preferably adjusted so that the non-volatile concentration of the pressure-sensitive adhesive composition is preferably 20 to 80% by weight, more preferably 30 to 60% by weight.

[0068] The pressure-sensitive adhesive composition of the present invention may further contain additives such as resins such as acrylic resins, urethane resins, and epoxy resins, fillers such as silica, and additives such as surface conditioners, pigments, bulking agents, release agents, flame retardants, viscosity regulators, plasticizers, antibacterial agents, UV absorbers, antifungal agents, defoamers, colorants, and stabilizers. These may be used alone or in combination of two or more.

[0069] The pressure-sensitive adhesive composition of the present invention can be obtained by mixing the polyester resin (A) and the polyisocyanate (B), and optionally the curing agent (B'), the hydrogenated petroleum resin (C), the curing catalyst (D), the organic solvent (E) and additives. The method and order of adding each component are not particularly limited.

[0070] The present invention also includes a cured product of the adhesive composition. For example, the method includes coating the adhesive composition of the present invention on a substrate and drying it under heating. Note that a substrate may be further laminated on the coated adhesive composition.

[0071] Examples of the substrate include metal, plastic film, release film, glass, etc. These may be used alone or in combination of two or more.

[0072] Examples of metals include iron, copper, silver, aluminum, aluminum-plated steel sheet, tin-free steel sheet, stainless steel sheet, zinc phosphate-treated sheet, zinc / zinc alloy-plated steel sheet (bonded steel sheet), and the like.

[0073] Examples of plastic films include polyesters such as acetonitrile-butadiene-styrene (ABS), polycarbonate, polyethylene, polypropylene, polyethylene terephthalate, and polyethylene naphthalate; acrylics such as polymethyl methacrylate; fluorine-based resins such as polytetrafluoroethylene (PTFE), perfluoroalkoxyalkane (PFA), and polyvinylidene fluoride (PVDF); polyimide, polyamide, polyphenylene ether, polyphenylene sulfide, polystyrene, polycarbonate, liquid crystal polymer, and cycloolefin polymer. In addition, the plastic film may have a metal pattern printed on the surface of the film, or a metal or metal oxide may be vapor-deposited on the film.

[0074] A release film is a film in which a release agent is applied to the surface of a substrate, and is classified into heavy release films, medium release films, and light release films depending on the force required to peel the film off.

[0075] Examples of the coating method include spraying, natural roll coating, reverse roll coating, curtain flow coating, gravure roll coating, bar coating, knife coating, dip roll coating, and comma coating. The coating amount is 10 to 500 g / m. 2 is preferable, and 20 to 200 g / m 2 is more preferred.

[0076] Examples of the heating method include a circulating air dryer and a heating furnace.

[0077] As drying conditions, for example, the temperature is preferably 50 to 200° C., more preferably 80 to 150° C., and the drying time is preferably 30 seconds to 1 hour, more preferably 1 minute to 20 minutes.

[0078] When one or both sides of the substrate have a release film, the cured product of the present invention can be used as a pressure-sensitive adhesive sheet by peeling off the release film.

[0079] The laminate of the present invention has the above-mentioned cured product on at least one side of a substrate. The substrate to be used, the method for applying the pressure-sensitive adhesive composition, the irradiation conditions, etc. are the same as those described above. EXAMPLES

[0080] The present invention will be specifically described below through examples and comparative examples. Note that the technical scope of the present invention is not limited thereto. In addition, "parts" and "%" in the examples are by weight unless otherwise specified.

[0081] (Hydroxyl value of polyester resin (A)) The hydroxyl value was measured according to JIS K-0070.

[0082] (Glass transition temperature of polyester resin (A)) 5 mg of polyester resin (A) was placed in an aluminum pressure-lid container, sealed, and cooled to −80° C. using liquid nitrogen. Using a commercially available differential scanning calorimeter (product name: “EXSTAR6000 DSC 6200”, manufactured by Seiko Instruments Inc.), the temperature was raised to 150° C. at a rate of 20° C. / min., and in the obtained endothermic curve, the temperature at the intersection of the extension of the baseline before the endothermic peak (below the glass transition temperature) and the tangent to the endothermic peak (the tangent showing the maximum slope between the rising part of the peak and the apex of the peak) was taken as the glass transition temperature (Tg, unit: ° C.).

[0083] (Number average molecular weight of polyester resin (A)) The number average molecular weight was measured in terms of polystyrene by gel permeation chromatography (measuring device: HCL-8320 (manufactured by Tosoh Corporation), columns: TSKgel G2000H, TSKgel G4000H (manufactured by Tosoh Corporation)).

[0084] Synthesis Example 1 A reactor equipped with a stirrer, a thermometer, a nitrogen gas inlet tube, and a reflux dehydration device was charged with 10.3 parts of dimethyl terephthalate, 93.9 parts of hydrogenated polybutadiene polyol (product name: "NISSO-PB GI-3000", hydroxyl value: 25 to 35 mg KOH / g, manufactured by Nippon Soda Co., Ltd.) (hereinafter abbreviated as "GI-3000"), 65.9 parts of hydrogenated dimer diol (product name: "Pripol 2033", hydroxyl value: 202 to 212 mg KOH / g, manufactured by Equus Japan Co., Ltd.) (hereinafter abbreviated as "Pripol 2033"), 13.6 parts of 2-methyl-1,3-propanediol, and 0.02 parts of tetrabutyl titanate, and the reaction system was gradually heated to 220 ° C. while removing the by-product methanol from the system by heating and melting, and further stirred for 3 hours. Next, 16.3 parts of isophthalic acid was added, and the reaction system was gradually heated to 250°C while removing by-product water from the system, and further stirred for 3 hours. Next, a vacuum pressure reducing device was connected, and polycondensation reaction was carried out at 250°C and 1.0 kPa or less for 4 hours to obtain polyester resin (A-1). The hydroxyl value, glass transition temperature, and number average molecular weight of the obtained polyester resin (A-1) are shown in Table 1 (same below).

[0085] Synthesis Example 2 In a reaction apparatus similar to that of Synthesis Example 1, 11.0 parts of dimethyl terephthalate, 98.0 parts of GI-3000, 68.8 parts of Pripol2033, 4.8 parts of 2-methyl-1,3-propanediol, and 0.02 parts of tetrabutyl titanate were charged, and the reaction system was gradually heated to 220 ° C. while removing the by-product methanol from the system by heating and melting, and further stirred for 3 hours. Next, 17.0 parts of isophthalic acid and 0.4 parts of trimellitic anhydride were charged, and the reaction system was gradually heated to 250 ° C. while removing the by-product water from the system, and further stirred for 3 hours. Next, a vacuum pressure reduction device was connected, and a polycondensation reaction was carried out at 250 ° C. at 1.0 kPa or less for 10 hours to obtain a polyester resin (A-2).

[0086] Synthesis Example 3 In a reaction apparatus similar to that of Synthesis Example 1, 8.9 parts of dimethyl terephthalate, 3.7 parts of dimethyl 2,6-naphthalenedicarboxylate, 94.5 parts of GI-3000, 66.3 parts of Pripol2033, 11.4 parts of 1,3-propanediol, 0.3 parts of trimethylolpropane, and 0.02 parts of tetrabutyl titanate were charged, and the reaction system was gradually heated to 220°C while removing the by-product methanol from the system by heating and melting, and further stirred for 3 hours. Next, 12.7 parts of isophthalic acid, 1.1 parts of phthalic anhydride, 0.8 parts of 1,4-cyclohexanedicarboxylic acid, and 0.4 parts of adipic acid were charged, and the reaction system was gradually heated to 250°C while removing the by-product water from the system, and further stirred for 3 hours. Next, a vacuum pressure reducing device was connected, and a polycondensation reaction was carried out at 250°C at 1.0 kPa or less for 5 hours to obtain a polyester resin (A-3).

[0087] Synthesis Example 4 In a reaction apparatus similar to that of Synthesis Example 1, 27.4 parts of 2,5-dimethyl furan dicarboxylate, 93.3 parts of GI-3000, 65.5 parts of Pripol 2033, and 13.6 parts of 2-methyl-1,3-propanediol were charged, and the reaction system was gradually heated to 220 ° C. while removing the by-produced methanol from the system by heating and melting, and further stirred for 3 hours. Next, 0.2 parts of trimellitic anhydride were charged, and the reaction system was gradually heated to 250 ° C. while removing the by-produced water from the system, and further stirred for 3 hours. Next, a vacuum pressure reduction device was connected, and a polycondensation reaction was carried out at 250 ° C. at 1.0 kPa or less for 3 hours to obtain a polyester resin (A-4).

[0088] Synthesis Example 5 In a reaction apparatus similar to that of Synthesis Example 1, 11.8 parts of dimethyl terephthalate, 78.1 parts of hydrogenated polyisoprene polyol (product name: "EPOL", hydroxyl value: 50 mgKOH / g, manufactured by Idemitsu Kosan Co., Ltd.), 75.7 parts of Pripol2033, 15.7 parts of 2-methyl-1,3-propanediol, and 0.02 parts of tetrabutyl titanate were charged, and the reaction system was gradually heated to 220 ° C. while removing the by-produced methanol from the system by heating and melting, and further stirred for 3 hours. Next, 18.5 parts of isophthalic acid and 0.2 parts of trimellitic anhydride were charged, and the reaction system was gradually heated to 250 ° C. while removing the by-produced water from the system, and further stirred for 3 hours. Next, a vacuum pressure reducing device was connected, and a polycondensation reaction was carried out at 245 ° C. and 1.0 kPa or less for 2 hours to obtain a polyester resin (A-5).

[0089] Synthesis Example 6 A reactor equipped with a stirrer, a thermometer, a nitrogen gas inlet tube, and a reflux dehydration device was charged with 6.4 parts of dimethyl terephthalate, 145.0 parts of GI-3000, 28.7 parts of Pripol2033, 9.0 parts of 2-methyl-1,3-propanediol, and 0.02 parts of tetrabutyl titanate, and the reaction system was gradually heated to 220 ° C. while removing the by-product methanol from the system by heating and melting, and further stirred for 3 hours. Next, 10.7 parts of isophthalic acid and 0.3 parts of trimellitic anhydride were charged, and the reaction system was gradually heated to 250 ° C. while removing the by-product water from the system, and further stirred for 3 hours. Next, a vacuum pressure reduction device was connected, and a polycondensation reaction was carried out at 250 ° C. at 1.0 kPa or less for 2 hours to obtain a polyester resin (A-6).

[0090] Synthesis Example 7 A reactor equipped with a stirrer, a thermometer, a nitrogen gas inlet tube, and a reflux dehydration device was charged with 8.6 parts of dimethyl terephthalate, 125.3 parts of GI-3000, 36.7 parts of Pripol2033, 14.6 parts of 2-methyl-1,3-propanediol, and 0.02 parts of tetrabutyl titanate, and the reaction system was gradually heated to 220 ° C. while removing the by-product methanol from the system by heating and melting, and further stirred for 3 hours. Next, 14.5 parts of isophthalic acid and 0.3 parts of trimellitic anhydride were charged, and the reaction system was gradually heated to 250 ° C. while removing the by-product water from the system, and further stirred for 3 hours. Next, a vacuum pressure reduction device was connected, and a polycondensation reaction was carried out at 250 ° C. at 1.0 kPa or less for 2 hours to obtain a polyester resin (A-7).

[0091] Comparative synthesis example 1 In a reaction apparatus similar to that of Synthesis Example 1, 13.8 parts of dimethyl terephthalate, 126.0 parts of GI-3000, 8.2 parts of 2-methyl-1,3-propanediol, 30.0 parts of 1,10-decanediol, and 0.02 parts of tetrabutyl titanate were charged, and the reaction system was gradually heated to 220°C while removing the by-product methanol from the system by heating and melting, and further stirred for 3 hours. Next, 21.9 parts of isophthalic acid were charged, and the reaction system was gradually heated to 250°C while removing the by-product water from the system, and further stirred for 3 hours. Next, a vacuum pressure reducing device was connected, and a polycondensation reaction was carried out at 250°C at 1.0 kPa or less for 3 hours to obtain a polyester resin (F-1).

[0092] Comparative synthesis example 2 In a reaction apparatus similar to that of Synthesis Example 1, 4.0 parts of dimethyl terephthalate, 184.2 parts of GI-3000, 5.4 parts of 2-methyl-1,3-propanediol, and 0.02 parts of tetrabutyl titanate were charged, and the reaction system was gradually heated to 220°C while removing the by-product methanol from the system by heating and melting, and further stirred for 3 hours. Next, 6.4 parts of isophthalic acid were charged, and the reaction system was gradually heated to 250°C while removing the by-product water from the system, and further stirred for 3 hours. Next, a vacuum pressure reduction device was connected, and a polycondensation reaction was carried out at 250°C at 1.0 kPa or less for 3 hours to obtain a polyester resin (F-2).

[0093] Comparative synthesis example 3 In a reaction apparatus similar to that of Synthesis Example 1, 14.3 parts of isophthalic acid, 0.2 parts of trimellitic anhydride, 6.9 parts of adipic acid, 97.0 parts of GI-3000, 67.9 parts of Pripol2033, and 13.8 parts of 2-methyl-1,3-propanediol were charged, and the reaction system was gradually heated to 250 ° C. while removing the by-product water from the system by heating and melting, and further stirred for 2 hours. Next, a vacuum pressure reducing device was connected, and a polycondensation reaction was carried out at 250 ° C. and 1.0 kPa or less for 2 hours to obtain a polyester resin (F-3).

[0094] Comparative synthesis example 4 In a reaction apparatus similar to that of Synthesis Example 1, 18.3 parts of dimethyl terephthalate, 145.0 parts of Pripol 2033, and 7.6 parts of 2-methyl-1,3-propanediol were charged, and the reaction system was gradually heated to 220°C while removing the by-product methanol from the system by heating and melting, and further stirred for 3 hours. Next, 29.1 parts of isophthalic acid were charged, and the reaction system was gradually heated to 250°C while removing the by-product water from the system, and further stirred for 3 hours. Next, a vacuum pressure reduction device was connected, and a polycondensation reaction was carried out at 250°C at 1.0 kPa or less for 8 hours to obtain a polyester resin (F-4).

[0095] [Table 1]

[0096] Example 1 100 parts of polyester resin (A-1), 2.5 parts of hydrogenated xylylene diisocyanate nurate (product name: "Takenate D-127N", manufactured by Mitsui Chemicals, Inc.), 0.02 parts of curing catalyst (product name: "Neostan U-810", dioctyltin dilaurate, manufactured by Nitto Kasei Co., Ltd.), and 153.8 parts of butyl acetate were charged and stirred at 25°C for 1 hour to obtain a pressure-sensitive adhesive composition with a non-volatile content of 40% by weight.

[0097] Examples 2 to 12, Comparative Examples 1 to 5 The same procedure as in Example 1 was carried out except that the components and amounts used were changed as shown in Table 2, to obtain each of the pressure-sensitive adhesive compositions.

[0098] (Preparation of cured product (adhesive sheet)) Each adhesive composition was coated on a heavy release treated polyester film (product name: "SP-PET-03-75BU", thickness: 75 μm, manufactured by PANAC Co., Ltd.) so that the thickness after curing was 75 μm, and then dried for 5 minutes in a 120 ° C. circulating air dryer, and the release treated surface of a light release treated polyester film (product name: "SP-PET-01-38BU", thickness: 38 μm, manufactured by PANAC Co., Ltd.) was attached onto the coating layer to obtain a laminate (1) (light release treated polyester film / adhesive layer / heavy release treated polyester film). This was cut into a test piece of 1 cm × 1 cm, and the light release treated polyester film and the heavy release treated polyester film were peeled off from the test piece to obtain each cured product (adhesive sheet).

[0099] (Dielectric constant and dielectric loss tangent) Using a network analyzer (Keysight Technologies, device name: "P5003A") and a split post dielectric resonator (QWED) with a measurement frequency of 10.124 GHz, the resonant frequency and peak Q value of the resonator alone with nothing inserted were measured. Next, the pressure-sensitive adhesive sheet was inserted into a resonator, and the resonance frequency and Q value were measured when the test piece was inserted. The dielectric constant (Dk) was calculated from the difference in resonance frequency between the resonator alone and when the test piece was inserted, and the dielectric loss tangent (Df) was calculated from the difference in Q value and the difference in resonance frequency between the resonator alone and when the test piece was inserted. The results are shown in Table 2.

[0100] (Adhesive strength) Each adhesive composition was coated onto a polyester film (product name: "Lumirror 50T60", thickness: 50 μm, manufactured by PANAC Corporation) so that the thickness after curing would be 75 μm, and dried for 5 minutes in a circulating air dryer at 120° C. The release-treated surface of a light release-treated polyester film (product name: "SP-PET-01-38BU", thickness: 38 μm, manufactured by PANAC Corporation) was then bonded onto the coating layer to obtain a laminate (1) (light release-treated polyester film / adhesive layer / polyester film). A test piece of 10 cm x 25 mm was cut from this laminate (1), the light release treated polyester film was peeled off, the adhesive layer side was placed on a glass plate (manufactured by Nippon Test Panel Co., Ltd.), and the adhesive layer was pressed against a glass plate using a 2 kg roller to produce a laminate (2) (polyester film / adhesive layer / glass plate). The laminate was left to stand for 24 hours under conditions of a temperature of 25°C and a humidity of 50%. The adhesive layer was then peeled off from the glass plate in a 180° direction at a speed of 300 mm / min to measure the adhesive strength (N / 25 mm). A commercially available tester (product name: "Tensilon Universal Material Tester", manufactured by AND Co., Ltd.) was used for the measurement. Furthermore, using the same procedure, laminates (2) were produced by changing the glass plate to an acrylic resin (product name: "Standard Test Plate Acrylic (Transparent)", manufactured by Nippon Testpanel Co., Ltd.) or a cycloolefin polymer (product name: "ZeonorFilm ZF-16", manufactured by Zeon Corporation), and the adhesive strength was measured in the same manner. The results are shown in Table 2. Note that in the adhesive compositions of Comparative Examples 1 and 2, cohesive failure (CF) occurred and measurement was not possible.

[0101] (transparency) Using the same procedure as described in the previous paragraph on adhesive strength, the polyester film of laminate (1) was changed to a glass plate (10 cm × 10 cm × 2 mm), and laminate (3) (light release-treated polyester film / adhesive layer / glass plate) was prepared. The light release treated polyester film was peeled off from the laminate (3), and the transparency (haze) was measured in accordance with JIS K 7136:2000 using a commercially available measuring device (product name "Haze / Transmittance Meter HM-150", manufactured by Murakami Color Research Laboratory Co., Ltd.). The obtained haze value includes the haze value of the substrate (glass plate). The results are shown in Table 2.

[0102] [Table 2]

[0103] The symbols shown in Table 2 represent the following components. (polyester resin) A-1 to A-7: Polyester resins of synthesis examples 1 to 7 (composite in the same order) F-1 to F-4: Comparative synthesis examples 1 to 4 polyester resins (composite in the same order) (hardening agent) B-1 - Hydrogenated xylylene diisocyanate nurate, product name: Takenate D-127N, manufactured by Mitsui Chemicals, Inc. B-2-Nurate form of hexamethylene diisocyanate, product name: "Coronate HX", manufactured by Asahi Kasei Chemicals Corporation B-3-Dicyclohexylmethane-4,4'-diisocyanate, product name: "Desmodur W", manufactured by Sumika Covestro Urethane Co., Ltd. G-1-Full ether type methylated melamine resin, product name: Cymel 303LF, manufactured by Allnex Japan Co., Ltd. (Hydrogenated petroleum resin) C-1 - Product name: "Alcon M-100", manufactured by Arakawa Chemical Industries, Ltd. C-2-Product name: "Alcon P-100", manufactured by Arakawa Chemical Industries, Ltd. (curing catalyst) U-810-Dioctyltin dilaurate, product name: "Neostan U-810", manufactured by Nitto Kasei Co., Ltd. ·PTS-Para Toluene Sulfonic Acid

Claims

1. Polycarboxylic acid (a1) containing polycarboxylic acid (a1-1) having an aromatic ring and / or a heterocyclic ring; Polyolefin polyol (a2-1) with a hydroxyl value of 10 mgKOH / g or more and less than 100 mgKOH / g; Polyol (a2-2) having a hydroxyl value of 100 mgKOH / g or more and less than 500 mgKOH / g, and A polyester resin (A) which is a reaction product of a polyol (a2) composed of a polyol (a2-3) having a hydroxyl value of 500 mgKOH / g or more and 2000 mgKOH / g or less and satisfies formulas (1) and (2); A pressure-sensitive adhesive composition comprising a polyisocyanate (B). (Formula 1) 0.8≦w≦1 (In formula 1, w represents the molar fraction of the polycarboxylic acid having an aromatic ring and / or a heterocyclic ring contained in the polycarboxylic acid (a1).) (Formula 2) 0<x≦0.5, 0<y<0.74, and z>0.1 (In formula 2, x represents the molar fraction of the component (a2-1) contained in the polyol (a2), y represents the molar fraction of the component (a2-2) contained in the polyol (a2), z represents the molar fraction of the component (a2-3) contained in the polyol (a2), and x+y+z=1.)

2. The pressure-sensitive adhesive composition according to claim 1, wherein the component (a2-2) comprises a dimer diol.

3. The pressure-sensitive adhesive composition according to claim 1 or 2, wherein the component (a2-3) comprises an alkanediol and / or an alkylalkanediol.

4. 3. The pressure-sensitive adhesive composition according to claim 1, wherein the component (B) comprises at least one member selected from the group consisting of an aliphatic polyisocyanate, an alicyclic polyisocyanate, a nurate form of an aliphatic polyisocyanate, and a nurate form of an alicyclic polyisocyanate.

5. The pressure-sensitive adhesive composition according to claim 1 or 2, further comprising a hydrogenated petroleum resin (C).

6. A cured product of the pressure-sensitive adhesive composition according to claim 1.

7. A laminate having the cured product according to claim 6 on at least one surface of a substrate.

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