Reactive adhesive, laminate, packaging material, and packaged article

Abstract

To provide: a reactive adhesive that has excellent alkali releasability and does not undergo strength degradation over time even when the contents include acidic components, alkaline components, volatile components, surfactant components, and the like, and that also exhibits excellent recyclability and long-term content resistance; and a laminate, a packaging material and a packaged article that achieve both recyclability and long-term content resistance.SOLUTION: The reactive adhesive comprises a polyol composition and a polyisocyanate. The polyol composition comprises a polyester polyol (A) and a rosin-modified resin (B) having a hydroxyl group and an acidic group. The polyester polyol (A) is produced from polybasic acids or derivatives thereof and polyhydric alcohols as essential raw materials. The content of polybasic acids or derivatives thereof having an aromatic ring in the total amount of polybasic acids or derivatives thereof is 35 mass% or more. The mass ratio ((B) / (A)) of the rosin-modified resin (B) to the polyester polyol (A) is from 0.03 to 1.5.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a reactive adhesive containing a polyol composition and a polyisocyanate, which has alkali releasing properties, does not experience a decrease in strength over time, and has excellent resistance to contents. [Background technology]

[0002] In recent years, packaging made from plastic film, plastic bottles, and other plastic products have been discarded and dumped as garbage in the ocean, causing environmental pollution. These plastic products break down in seawater and become submicron-sized fragments (microplastics), which float in the seawater. When these microplastics are ingested by marine organisms such as fish, they become concentrated in the organisms' bodies, and there are concerns that they may affect the health of seabirds and humans who consume these marine organisms as food.

[0003] In recent years, efforts have been made to separate, recover, and recycle plastic films from packaging materials by using adhesives that can be released between films using a release liquid such as water or an alkaline aqueous solution as the adhesive used when laminating plastic films in packaging materials.

[0004] As an example of a packaging material that can be recycled using such a specific treatment liquid and an adhesive composition having releasability, Patent Document 1 describes the use of a reactive adhesive in which a resin having an acidic group or a low molecular weight compound is added to a polyisocyanate composition and a polyol composition.

[0005] [Patent Document 1] International Publication No. 2020 / 066652 Summary of the Invention [Problem to be solved by the invention]

[0006] However, Patent Document 1 does not describe the problem of the present invention, which is to achieve both alkali release property and resistance to contents over time for contents containing acid components, alkali components, volatile components such as fragrances, surfactant components, etc., such as shampoos and conditioners. In addition, the adhesive using a resin having an acidic group or a low molecular weight compound described in Patent Document 1 cannot solve the problem of resistance to contents. In detail, when the adhesive is used for contents such as packaging materials, shampoos, conditioners, laundry detergents, bath detergents, kitchen detergents, fabric softeners, and bleaches, the adhesive layer is damaged by acid components, alkali components, volatile components such as fragrances, surfactant components, etc., in the contents during long-term display, reducing the adhesive strength, and there is a problem that release property and resistance to contents over time cannot be achieved at the same time. Therefore, an object of the present invention is to provide a reactive adhesive that has excellent alkali release properties and does not experience a decrease in strength over time even when the contents contain acid components, alkaline components, volatile components, surfactant components, etc., and that has excellent recyclability and resistance to contents over time, as well as a laminate, packaging material, and package that use the reactive adhesive and achieve both recyclability and resistance to contents over time. [Means for solving the problem]

[0007] <1> A reactive adhesive comprising a polyol composition and a polyisocyanate, the polyol composition comprising a polyester polyol (A) and a rosin-modified resin (B) having a hydroxyl group and an acidic group, the polyester polyol (A) having a polybasic acid or a derivative thereof and a polyhydric alcohol as essential raw materials, the polybasic acid or a derivative thereof containing a polybasic acid or a derivative thereof having an aromatic ring in the polybasic acid or a derivative thereof being 35 mass% or more, and the mass ratio ((B) / (A)) of the rosin-modified resin (B) to the polyester polyol (A) being 0.03 to 1.5.

[0008] <2> : The acid value (AV) of the rosin-modified resin (B) B ) and hydroxyl value (OHV B ) satisfies the following formula (1), <1> The reactive adhesive according to claim 1. Formula (1): AV B (mgKOH / g) / OHV B (mgKOH / g) = 0.25 to 1.0

[0009] <3> : The acid value (AV) of the polyester polyol (A) A ) and the acid value (AV B ) satisfies the following formula (2), <1> or <2> The reactive adhesive according to claim 1. Formula 2: AV A (mgKOH / g) / AV B (mgKOH / g) = 0.2 to 1.7

[0010] <4> The rosin-modified resin (B) includes a reactant having an ester bond, which is formed by reacting a carboxylic acid in a compound obtained by a Diels-Alder reaction between an organic acid having a conjugated double bond, which is included in a rosin acid (b1), and an α,β-unsaturated carboxylic acid or an acid anhydride thereof (b2), with a polyol (b3). <1> ~ <3> 13. The reactive adhesive according to any one of claims 1 to 12.

[0011] <5> The polyester polyol (A) has a number average molecular weight of 5,000 to 20,000. <1> ~ <4> 13. The reactive adhesive according to any one of claims 1 to 12.

[0012] <6> The polyisocyanate includes at least one selected from the group consisting of aliphatic polyisocyanates and araliphatic polyisocyanates. <1> ~ <5> 13. The reactive adhesive according to any one of claims 1 to 12.

[0013] <7> : <1> ~ <6> A cured product obtained by curing the reactive adhesive described in any one of claims 1 to 4.

[0014] <8> A laminate having an adhesive layer between at least two resin layers, the adhesive layer being <7> A laminate which is the cured product according to claim 1.

[0015] <9> : <8> A packaging material using the laminate described in claim 1.

[0016] <10> A package using the packaging material according to claim 9. Effect of the Invention

[0017] The present invention can provide a reactive adhesive that has excellent alkali release properties, and does not experience a decrease in strength over time even when the contents contain components that are highly damaging to the adhesive layer, such as acid components, alkaline components, volatile components, or surfactant components, and that has excellent recyclability and resistance to contents over time, as well as a laminate, packaging material, and package that use the reactive adhesive and achieve both recyclability and resistance to contents over time. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] The following describes in detail the embodiments of the present invention. However, the following description of the embodiments or requirements is merely an example of the embodiments of the present invention, and the present invention is not limited to these contents as long as it does not deviate from the gist of the present invention.

[0019] <<Reactive adhesives>> The reactive adhesive of the present invention comprises a polyol composition containing polyester polyol (A) and a rosin-modified resin (B) having a hydroxyl group and an acidic group, and a polyisocyanate, wherein the polyester polyol (A) has a polybasic acid or a derivative thereof and a polyhydric alcohol as essential raw materials, the proportion of a polybasic acid or a derivative thereof having an aromatic ring in the polybasic acid or derivative thereof is 35 mass% or more, and the mass ratio of the rosin-modified resin (B) to the polyester polyol (A) ((B) / (A)) is 0.03 to 1.5. By using a combination of polyester polyol (A) having a proportion of polybasic acid having an aromatic ring of 35 mass% or more and rosin-modified resin (B) having a specified range of hydroxyl groups and acidic groups, it is possible to achieve both resistance to contents over time and alkali release properties (recyclability).

[0020] The above effects are believed to be due to the following mechanism. Regarding the use of a rosin modified resin having a hydroxyl group and an acidic group in a predetermined range of amount, first, by using a rosin resin, the adhesion is improved as a tackifier. Furthermore, the acidic groups of the rosin resin not only promote dissolution or swelling of the adhesive in a release liquid such as an alkaline aqueous solution, but also facilitate penetration of the alkaline aqueous solution, thereby promoting hydrolysis of the polyester polyol and improving the release property. In addition, the hydroxyl groups of the rosin resin react with the isocyanate groups of the polyisocyanate to introduce highly crystalline sites derived from the rosin resin into the adhesive layer, suppressing the penetration of the contents into the adhesive layer and improving the resistance to the contents. Furthermore, when the mass ratio (B) / (A) is 0.03 or more and 1.5 or less, it is possible to achieve both resistance to the contents and recyclability. In addition, by having the polyester polyol contain 35% by mass or more of a polybasic acid or a derivative thereof having an aromatic ring, the adhesive layer is less likely to be damaged even if the contents components penetrate the plastic film and reach the adhesive layer during storage, and the adhesive strength can be maintained for a long period of time.

[0021] In other words, the reactive adhesive of the present invention utilizes a polyester polyol (A) having a proportion of polybasic acid or a derivative thereof having an aromatic ring of 35 mass% or more, a rosin-modified resin (B) having an acid group and an acidic group, and a (B) / (A) ratio within a specified range, which act synergistically to achieve both excellent alkali release properties and excellent resistance to contents over time for contents that contain components that cause significant damage to the adhesive layer.

[0022] <Polyol Composition> As described above, it is important that the polyol composition in the present invention contains polyester polyol (A) in which the proportion of polybasic acid or derivatives thereof having an aromatic ring is 35 mass% or more, and rosin-modified resin (B) having hydroxyl groups and acidic groups, with (B) / (A) being in the range of 0.03 to 1.5. When the polyester polyol (A) contains 35% by mass or more of polybasic acid or its derivative having an aromatic ring, the adhesive layer is less likely to be damaged even if the content component penetrates the plastic film and reaches the adhesive layer during storage, and the adhesive strength can be maintained for a long period of time. The proportion of polybasic acid or its derivative having an aromatic ring is preferably 40% by mass or more, more preferably 45% by mass or more. Also, it is preferably 90% by mass or less, more preferably 85% by mass or less. In addition, by making the mass ratio (B) / (A) 0.03 or more and 1.5 or less, the hydroxyl group of the rosin resin reacts with the isocyanate group of the polyisocyanate, and a highly crystalline portion derived from the rosin resin is introduced into the adhesive layer, and the penetration of the contents into the adhesive layer can be suppressed. From the viewpoint of achieving both content resistance and recyclability, the mass ratio (B) / (A) is preferably 0.1 or more, more preferably 0.15 or more. In addition, it is preferably 1.25 or less, more preferably 1.0 or less.

[0023] [Polyester polyol (A)] The polyester polyol (A) is essentially made of a polybasic acid or its derivative and a polyhydric alcohol, and it is important that the proportion of the polybasic acid or its derivative having an aromatic ring is 35% by mass or more based on the total mass of the polybasic acid or its derivative. By including such a polyester polyol (A), it is possible to impart excellent resistance to contents over time, which is preferable. The polyester polyol (A) may be used alone, or two or more types having different molecular weights or glass transition temperatures may be used in combination from the viewpoint of coatability and performance improvement.

[0024] (Polybasic acids or their derivatives, polyhydric alcohols) Examples of the polybasic acid or a derivative thereof include polybasic acids having an aromatic ring, such as terephthalic acid, isophthalic acid, naphthalenedicarboxylic acid, phthalic anhydride, trimellitic acid, trimellitic anhydride, pyromellitic acid, pyromellitic anhydride, naphthalic acid, and naphthalic anhydride; aliphatic polybasic acids, such as adipic acid, azelaic acid, sebacic acid, succinic acid, glutaric acid, dodecanecarboxylic acid, fumaric acid, 1,3-cyclopentanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, maleic anhydride, and itaconic anhydride; alkyl esters thereof; and mixtures thereof. Furthermore, a monofunctional carboxylic acid such as benzoic acid, phenylacetic acid, or 3-phenylpropionic acid may be used in combination to adjust the molecular weight.

[0025] Examples of the polyhydric alcohol include polyhydric alcohols having an alkylene oxide chain, such as diethylene glycol, dipropylene glycol, triethylene glycol, dineopentyl glycol, polyoxyethylene glycol, polyoxypropylene glycol, polytetramethylene ether glycol, and polyether polyol; polyhydric alcohols not having an alkylene oxide chain, such as ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, neopentyl glycol, trimethylolpropane, glycerin, 1,6-hexanediol, 1,4-butanediol, 1,4-cyclohexanedimethanol, 3-methyl-1,5-pentanediol, 2-methyl-1,3-propanediol, 3,3'-dimethylolheptane, and 1,9-nonanediol; and mixtures thereof. As the hydroxyl group component, polycarbonate polyol, polyolefin polyol, acrylic polyol, polyurethane polyol, or a mixture thereof may be used. Furthermore, a monofunctional alcohol may be used in combination to adjust the molecular weight.

[0026] The above polybasic acids or derivatives thereof, and polyhydric alcohols may be used alone or in combination of two or more kinds.

[0027] The polyester polyol (A) may be one in which a urethane bond is introduced by reacting a polyisocyanate with a hydroxyl group in the polyester polyol. The inclusion of a urethane bond provides excellent heat resistance and adhesiveness. Examples of the polyisocyanate include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, xylylene diisocyanate, diphenylmethane diisocyanate, isophorone diisocyanate, 1,5-naphthalene diisocyanate, hexamethylene diisocyanate, and hydrogenated diphenylmethane diisocyanate.

[0028] The polyester polyol (A) may be an acid-modified product in which a part of the hydroxyl groups in the polyester polyol is modified with an acid, and may be, for example, a product in which a carboxyl group is introduced by reacting with an acid anhydride. Examples of the acid anhydride include pyromellitic anhydride, mellitic anhydride, trimellitic anhydride, and trimellitic ester anhydride. Examples of the trimellitic ester anhydride include ethylene glycol bisanhydrotrimellitate and propylene glycol bisanhydrotrimellitate. The polyester polyol (A) preferably has an acidic group, since this improves the alkali releasability.

[0029] Acid value (AV) of polyester polyol (A) A ) is preferably 5.0 mgKOH / g or more, more preferably 10.0 mgKOH / g or more. Also, it is preferably 100 mgKOH / g or less, more preferably 80 mgKOH / g or less. When the acid value of the polyester polyol (A) is within the above range, when the polyester polyol (A) is brought into contact with a release liquid which is an alkaline aqueous solution, the penetration and decomposition of the alkaline aqueous solution is promoted, and the release property is improved.

[0030] The number average molecular weight (Mn) of the polyester polyol (A) is preferably 3,000 or more, more preferably 5,000 or more, and even more preferably 7,000 or more. It is also preferably 25,000 or less, more preferably 20,000 or less, and even more preferably 15,000 or less. When the number average molecular weight of the polyester polyol (A) is 3,000 or more, the coating property and the content resistance are improved. When it is 25,000 or less, the coating property and the release property are improved. For example, this ratio may be 3,000 to 25,000, 5,000 to 20,000, or 7,000 to 15,000.

[0031] When the polyol composition contains two or more polyester polyols (A), the above-mentioned effects can be obtained by having at least one polyester polyol (A) contained as a main component (e.g., 60 mass% or more) have the above-mentioned acid value and number average molecular weight.

[0032] When the polyol composition contains two or more polyester polyols (A), at least one of the polyester polyols (A) may have a number average molecular weight of less than 3,000 from the viewpoints of substrate adhesion and coatability. The content of the polyester polyol having a number average molecular weight of less than 3,000 is preferably 0 to 40 mass%, more preferably 0 to 30 mass%, based on the total mass of the polyester polyol (A). When it is 40 mass% or less, resistance to contents can be maintained. That is, based on the total mass of the polyester polyol (A), the content of the polyester polyol having a number average molecular weight of less than 3,000 may be preferably 40 mass% or less, more preferably 30 mass% or less. In one embodiment, the blending amount may be 0 mass%.

[0033] [Rosin-modified resin having hydroxyl groups and acidic groups (B)] The rosin-modified resin (B) in the present invention contains a rosin-derived skeleton in the resin skeleton, and has a hydroxyl group and an acidic group. By having a rosin-derived skeleton, a hydroxyl group, and an acidic group, it is possible to impart releasability and resistance to contents over time to the adhesive layer, which is the cured product of the adhesive. Examples of such rosin-modified resin (B) include various derivatives using rosin, which is mainly composed of abietic acid, palustric acid, isopimaric acid, etc., as a starting material, such as maleic anhydride or fumaric acid modified products of rosin, phenolic resin modified products of rosin, and polyol modified products of rosin.

[0034] In one embodiment, from the viewpoint of resistance to contents over time, the rosin-modified resin (B) preferably contains a reactant having an ester bond formed by a reaction between a carboxylic acid in a compound obtained by a Diels-Alder reaction between an organic acid having a conjugated double bond, contained in the rosin acids (b1), and an α,β-unsaturated carboxylic acid or an acid anhydride thereof (b2), and a polyol (b3).

[0035] In one embodiment, from the viewpoints of resistance to contents over time and coatability, the rosin-modified resin (B) more preferably contains a compound obtained by a Diels-Alder reaction between an organic acid having a conjugated double bond, contained in the rosin acids (b1), and an α,β-unsaturated carboxylic acid or an acid anhydride thereof (b2), and a reactant having an ester bond formed by a reaction between a carboxylic acid in an organic acid having no conjugated double bond, among the rosin acids (b1), and a polyol (b3).

[0036] In one embodiment, from the viewpoints of resistance to contents over time and coatability, the rosin-modified resin (B) more preferably contains a reactant having an ester bond formed by a reaction between a carboxylic acid in each of a compound obtained by a Diels-Alder reaction between an organic acid having a conjugated double bond, contained in the rosin acids (b1), and an α,β-unsaturated carboxylic acid or an acid anhydride thereof (a2), an organic acid among the rosin acids (b1) that does not have a conjugated double bond, and an organic acid or an acid anhydride thereof (b4) (excluding rosin acid (b1) and an α,β-unsaturated carboxylic acid or an acid anhydride thereof (b2)), and a polyol (b3).

[0037] [Rosin acids (b1)] The rosin acids (b1) in the present invention refer to monobasic acids having a cyclic diterpene skeleton, and may be rosin acid, disproportionated rosin acid, hydrogenated rosin acid, or alkali metal salts of the above compounds. Specific examples include abietic acid having a conjugated double bond, and its conjugated compounds, such as neoabietic acid, palustric acid, and levopimaric acid. Other examples include pimaric acid, isopimaric acid, sandaracopimaric acid, and dehydroabietic acid, which do not have a conjugated double bond. Examples of natural resins containing these rosin acids (b1) include gum rosin, tall oil rosin, and wood rosin.

[0038] The amount of rosin acids (b1) used to obtain the rosin-based resin (B) is preferably 10 to 60 mass%, more preferably 20 to 60 mass%, based on the total mass of the raw material for the rosin-modified resin (B). When the amount of rosin acids (b1) is 10 mass% or more, the alkali solubility is improved and the release property is good. When the amount of rosin acids (b1) is 60 mass% or less, the resistance to contents over time is good.

[0039] [α,β-unsaturated carboxylic acid or its anhydride (b2)] Examples of the α,β-unsaturated carboxylic acid or its anhydride (b2) include maleic acid, fumaric acid, citraconic acid, itaconic acid, crotonic acid, isocrotonic acid, and their anhydrides. From the viewpoint of reactivity with the rosin acids (b1), maleic acid or its anhydride is preferred.

[0040] In the Diels-Alder reaction, the amount of the α,β-unsaturated carboxylic acid or its anhydride (b2) is preferably 60 to 200 mol %, more preferably 70 to 180 mol %, and even more preferably 80 to 160 mol %, based on the rosin acids (b1). When the amount of the α,β-unsaturated carboxylic acid or its anhydride (b2) is within the above range, a rosin-modified resin (B) having excellent adhesion to substrates and resistance to contents over time can be easily obtained.

[0041] [Organic acids or their acid anhydrides (b4) (excluding rosin acids (b1) and α,β-unsaturated carboxylic acids or their acid anhydrides (b2)] In one embodiment, in order to obtain a rosin-modified resin, in addition to the rosin acids (b1) and the α,β-unsaturated carboxylic acid or its anhydride (b2), other organic acids or their anhydrides (a4) may be used alone or in combination of two or more. Examples of the organic acids or their anhydrides (b4) include the following:

[0042] (organic monobasic acid) Aromatic monobasic acids such as benzoic acid, methylbenzoic acid, tertiary butylbenzoic acid, naphthoic acid, and orthobenzoylbenzoic acid; compounds having conjugated double bonds but not a cyclic diterpene skeleton, such as conjugated linoleic acid, eleostearic acid, parinaric acid, and calendic acid.

[0043] (fatty acid) Linseed oil fatty acids, tung oil fatty acids, castor oil fatty acids, soybean oil fatty acids, tall oil fatty acids, rice bran oil fatty acids, palm oil fatty acids, coconut oil fatty acids, dehydrated castor oil fatty acids, capric acid, undecanoic acid, lauric acid, myristic acid, palmitic acid, stearic acid, isostearic acid, oleic acid, linoleic acid, and linolenic acid, etc.

[0044] (Alicyclic polybasic acid or its anhydride) 1,2,3,6-tetrahydrophthalic acid, 3-methyl-1,2,3,6-tetrahydrophthalic acid, 4-methyl-1,2,3,6-tetrahydrophthalic acid, 1,2-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, and acid anhydrides thereof, etc.

[0045] (Other organic polybasic acids or their anhydrides) Examples of suitable acid anhydrides include oxalic acid, malonic acid, succinic acid, glutaric acid, pimelic acid, adipic acid, sebacic acid, azelaic acid, alkenylsuccinic acids such as dodecenylsuccinic acid and pentadecenylsuccinic acid, o-phthalic acid, isophthalic acid, terephthalic acid, trimellitic acid, pyromellitic acid, and acid anhydrides thereof.

[0046] The amount of the organic acid or its acid anhydride (b4) is preferably 0 to 60 mass%, more preferably 0 to 50 mass%, based on the total mass of the raw material for the rosin modified resin (B). That is, based on the total amount of the raw material for the rosin modified resin, the amount of the organic acid or its acid anhydride (b4) may be preferably 60 mass% or less, more preferably 50 mass% or less. In one embodiment, the amount may be 0 mass%.

[0047] [Polyol (b3)] The polyol (b3) forms an ester bond by a reaction with a carboxylic acid in each of a compound obtained by a Diels-Alder reaction between an organic acid having a conjugated double bond contained in the rosin acids (b1) and an α,β-unsaturated carboxylic acid or its acid anhydride (a2), an organic acid having no conjugated double bond among the rosin acids (b1), and an organic acid or its acid anhydride (b4). Specific examples of the polyol (b3) include the following.

[0048] (Linear alkylene dihydric polyol) Ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,4-butanediol, 1,2-pentanediol, 1,5-pentanediol, 1,6-hexanediol, 1,2-hexanediol, 1,5-hexanediol, 2,5-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,2-octanediol, 1,9-nonanediol, 1,2-decanediol, 1,10-decanediol, 1,12-dodecanediol, 1,2-dodecanediol, 1,14-tetradecanediol, 1,2-tetradecanediol, 1,16-hexadecanediol, and 1,2-hexadecanediol, etc.

[0049] (Branched alkylene dihydric polyol) 2-methyl-2,4-pentanediol, 3-methyl-1,5-pentanediol, 2-methyl-2-propyl-1,3-propanediol, 2-butyl-2-ethyl-1,3-propanediol, 2,4-dimethyl-2,4-pentanediol, 2,2-dimethyl-1,3-propanediol, 2,2,4-trimethyl-1,3-pentanediol, dimethylol octane, 2-ethyl-1,3-hexanediol, 2,5-dimethyl-2,5-hexanediol, 2-methyl-1,8-octanediol, 2-butyl-2-ethyl-1,3-propanediol, and 2,4-diethyl-1,5-pentanediol, etc.

[0050] (Cyclic dihydric polyol) Cyclic alkylene dihydric polyols such as 1,2-cycloheptanediol, tricyclodecane dimethanol, 1,2-cyclohexanediol, 1,2-cyclohexanedimethanol, 1,3-cyclohexanediol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, hydrogenated bisphenol A, hydrogenated bisphenol F, hydrogenated bisphenol S, hydrogenated catechol, hydrogenated resorcinol, and hydrogenated hydroquinone; and aromatic dihydric polyols such as bisphenol A, bisphenol F, bisphenol S, catechol, resorcinol, and hydroquinone.

[0051] (Other dihydric polyols) Divalent polyether polyols such as polyethylene glycol (n=2 to 20), polypropylene glycol (n=2 to 20), and polytetramethylene glycol (n=2 to 20), as well as polyester polyols.

[0052] (Trivalent polyol) Glycerin, trimethylolpropane, 1,2,6-hexanetriol, 3-methylpentane-1,3,5-triol, hydroxymethylhexanediol, trimethylol octane, and the like.

[0053] (4 or more polyols) Pentaerythritol, diglycerin, ditrimethylolpropane, dipentaerythritol, sorbitol, inositol, tripentaerythritol, and the like.

[0054] [Properties of rosin-modified resin (B)] The rosin-modified resin (B) in the present invention has an acid value (AV B ) is preferably 10 mgKOH / g or more. Also, it is preferably 100 mgKOH / g or less, more preferably 80 mgKOH / g or less. When the acid value of the rosin-modified resin (B) is 10 mgKOH / g or more, the alkali solubility is excellent and the release property is improved. When it is 100 mgKOH / g or less, the resistance to the contents is improved. For example, this ratio may be 10 to 100 mgKOH / g, or 10 to 80 mgKOH / g.

[0055] The hydroxyl value (OHV) of rosin modified resin (B) B ) is preferably 10 mgKOH / g or more, more preferably 15 mgKOH / g or more. Also, it is preferably 300 mgKOH / g or less, more preferably 250 mgKOH / g or less. When it is in this range, the resistance to the contents is improved. For example, this ratio may be 10 to 300 mgKOH / g, or 15 to 250 mgKOH / g.

[0056] Acid value (AV) of rosin modified resin (B) B ) and hydroxyl value (OHV B From the viewpoint of resistance to contents over time, it is preferable that the value of (1) satisfies the following formula (1). Formula (1): AV B (mgKOH / g) / OHV B (mgKOH / g) = 0.25 to 1.0 The value of the above formula (1) is more preferably 0.3 to 0.8.

[0057] Acid value (AV) of polyester polyol (A) A ) and the acid value (AV) of the rosin-modified resin (B) B It is preferable that the value of ) satisfies the following formula (2). When it is 0.2 or more, it is excellent in terms of releasability and resistance to contents over time. When it is 1.7 or less, it is excellent in terms of resistance to contents. Formula 2: AV A (mgKOH / g) / AV B (mgKOH / g) = 0.2 to 1.7 The value of the above formula (2) is more preferably 0.3 to 1.5.

[0058] From the viewpoint of durability of the contents over time, the melting point of the rosin-modified resin (B) is preferably 50° C. or higher, more preferably 60° C. or higher, and preferably 100° C. or lower. The melting point can be measured using a Melting Point M-565 manufactured by BUCHI under conditions of a temperature rise rate of 0.5° C. / min.

[0059] The weight average molecular weight (Mw) of the rosin-modified resin (B) is preferably 3,000 to 50,000, and more preferably 3,000 to 30,000. Within this range, it is excellent in terms of achieving both resistance to contents over time and releasability.

[0060] The number average molecular weight (Mn) of the rosin-modified resin (B) is preferably from 500 to 3,000, more preferably from 500 to 2,500. When within this range, excellent coatability as an adhesive is achieved.

[0061] The ratio of the weight average molecular weight to the number average molecular weight (Mw / Mn) of the rosin-modified resin (B) is preferably 5 to 35, and more preferably 7 to 30. Within this range, the adhesive has excellent coatability, and is also excellent in terms of both content resistance over time and releasability.

[0062] [Other components that may be contained in the polyol composition] The polyol composition may contain a polyol other than the polyester polyol (A) (hereinafter, referred to as other polyol) within the range that does not impair the effects of the present invention. Examples of such other polyols include polyester polyols, polycarbonate polyols, polycaprolactone polyols, polyether polyols, polyolefin polyols, acrylic polyols, silicone polyols, castor oil-based polyols, and fluorine-based polyols, in which the proportion of polybasic acids or derivatives thereof having aromatic rings in the polybasic acids or derivatives thereof is less than 35 mass%.

[0063] From the viewpoint of improving the releasability, the polyol composition may contain a compound having an acidic group (excluding the polyester polyol (A) and the rosin-modified resin (B)). As the compound having an acidic group, for example, a resin having an acidic group or a low molecular weight compound having an acidic group can be used.

[0064] The term "resin" in the term "resin having an acidic group" refers to a compound having a weight average molecular weight of 1,000 or more. Examples of resins having an acidic group include cellulose resins, urethane resins, polyamide resins, vinyl chloride / vinyl acetate copolymers, ketone resins, polyester resins, and (meth)acrylic resins. Examples of the acidic group include a carboxy group, a phosphoric acid group, a sulfo group, a sulfino group, and the like, or esters or salts thereof. As the resin having an acidic group, for example, a rosin-modified resin having an acid value, such as maleic rosin or fumaric rosin, can be used. In addition, radical copolymers such as styrene-(meth)acrylic resin, styrene-maleic acid (anhydride) resin, and terpene-maleic acid (anhydride) resin, which are copolymerized with polymerizable monomers having an acidic group, such as polymerizable monomers having a carboxy group, such as itaconic acid, maleic acid, fumaric acid, and cinnamic acid; polymerizable monomers which are acid anhydrides, such as itaconic acid anhydride and maleic acid anhydride; polymerizable monomers having a sulfonic acid group, such as sulfonated styrene; and polymerizable monomers having a sulfonamide group, such as vinylbenzenesulfonamide, and the like, and acid-modified polyolefin resins can be used.

[0065] The low molecular weight compound having an acidic group refers to a compound having a molecular weight of less than 1,000. Examples of such compounds include saturated fatty acids such as lauric acid, myristic acid, palmitic acid, margaric acid, and stearic acid; unsaturated fatty acids such as oleic acid, linoleic acid, linolenic acid, arachidonic acid, eicosapentaenoic acid, docosahexaenoic acid, and sorbic acid; hydroxy acids such as lactic acid, malic acid, and citric acid; aromatic carboxylic acids such as benzoic acid, phthalic acid, isophthalic acid, terephthalic acid, salicylic acid, gallic acid, mellitic acid, and cinnamic acid; dicarboxylic acids such as oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, fumaric acid, and maleic acid; tricarboxylic acids such as aconitic acid; oxocarboxylic acids such as pyruvic acid and oxaloacetic acid; carboxylic acid derivatives such as amino acids and nitrocarboxylic acids; and acid anhydrides such as trimellitic anhydride and pyromellitic anhydride.

[0066] The acid value of the polyol composition as a whole is preferably 5 to 130 mgKOH / g, more preferably 5 to 100 mgKOH / g, which is excellent in terms of achieving both resistance to contents over time and releasability.

[0067] <Polyisocyanate> The polyisocyanate in the present invention is a compound having two or more isocyanate groups in one molecule. Examples of the polyisocyanate include aromatic polyisocyanates, aliphatic polyisocyanates, and aromatic aliphatic polyisocyanates. The above polyisocyanates may be used alone or in combination of two or more.

[0068] Examples of aromatic polyisocyanates include aromatic diisocyanates such as diphenylmethane diisocyanate, carbodiimide-modified diphenylmethane diisocyanate, phenylene diisocyanate, tolylene diisocyanate, and naphthalene diisocyanate; and polyisocyanates such as allophanate type, nurate type, biuret type, and adduct type derivatives derived from the above diisocyanates, or complexes thereof (e.g., polymethylene polyphenyl polyisocyanate, etc.).

[0069] Examples of the aliphatic polyisocyanate include acyclic aliphatic diisocyanates such as trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, 1,2-propylene diisocyanate, and 1,2-butylene diisocyanate; alicyclic diisocyanates such as 1,4-cyclohexane diisocyanate, 1,3-cyclohexane diisocyanate, and 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate (hereinafter, referred to as isophorone diisocyanate); and polyisocyanates such as allophanate type, nurate type, biuret type, and adduct type derivatives derived from the above diisocyanates, or complexes thereof. The derivatives are preferably of the nurate type or adduct type. As the aliphatic polyisocyanate, a polyisocyanate derived from hexamethylene diisocyanate (hereinafter also referred to as HDI) is preferred, which can easily ensure a balance between releasability and laminate properties.

[0070] Examples of the aromatic aliphatic polyisocyanate include aromatic aliphatic diisocyanates such as 1,3- or 1,4-xylylene diisocyanate or a mixture thereof, ω,ω'-diisocyanato-1,4-diethylbenzene, 1,3- or 1,4-bis(1-isocyanato-1-methylethyl)benzene or a mixture thereof; and polyisocyanates such as allophanate type, nurate type, biuret type, and adduct type derivatives derived from the above diisocyanates, or complexes thereof.

[0071] From the viewpoint of releasability, the polyisocyanate preferably contains at least one selected from the group consisting of aliphatic polyisocyanates and araliphatic polyisocyanates.

[0072] <<Reactive adhesive manufacturing>> The reactive adhesive of the present invention can be produced by mixing a polyol composition, a polyisocyanate, and optionally an organic solvent and other components. The polyisocyanate may be blended in such an amount that the ratio (NCO / OH) of the total number of isocyanate groups in the polyisocyanate to the total number of hydroxyl groups in the polyol composition is 0.3 to 10.0. The ratio (NCO / OH) is preferably 0.3 to 7.0, more preferably 0.5 to 5.0.

[0073] <Organic solvent> The reactive adhesive of the present invention may be either a solvent type or a solventless type, and may contain an organic solvent as necessary. As the organic solvent, one that can dissolve the polyol composition and polyisocyanate described above and is inactive to polyisocyanate is preferably used. Examples of such organic solvents include ester-based solvents such as ethyl acetate and n-butyl acetate; ketone-based solvents such as methyl ethyl ketone; and aromatic hydrocarbon-based solvents such as toluene and xylene, and can be appropriately selected and used.

[0074] <Other ingredients> (Silane coupling agent) The reactive adhesive of the present invention may further contain a silane coupling agent in order to enhance hot water resistance. Examples of the silane coupling agent include trialkoxysilanes having a vinyl group, such as vinyltrimethoxysilane and vinyltriethoxysilane; trialkoxysilanes having an amino group, such as 3-aminopropyltriethoxysilane and N-(2-aminoethyl)3-aminopropyltrimethoxysilane; and trialkoxysilanes having a glycidyl group, such as 3-glycidoxypropyltrimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane and 3-glycidoxypropyltriethoxysilane. The amount of the silane coupling agent is preferably 0.1 to 5% by mass, more preferably 0.5 to 3% by mass, based on the solid content of the reactive adhesive.

[0075] (Phosphorus oxygen acid or its derivatives) The reactive adhesive of the present invention may further contain a phosphorus oxyacid or a derivative thereof in order to enhance acid resistance. The phosphorus oxyacid may be any one having at least one free oxyacid, and examples of such phosphorus oxyacids include phosphoric acids such as hypophosphorous acid, phosphorous acid, orthophosphoric acid, and hypophosphoric acid; and condensed phosphoric acids such as metaphosphoric acid, pyrophosphoric acid, tripolyphosphoric acid, polyphosphoric acid, and ultraphosphoric acid. Examples of derivatives of phosphorus oxyacids include those obtained by partially esterifying the phosphorus oxyacids with alcohols while leaving at least one free oxyacid. Examples of such alcohols include aliphatic alcohols such as methanol, ethanol, ethylene glycol, and glycerin; and aromatic alcohols such as phenol, xylenol, hydroquinone, catechol, and phloroglucinol. Two or more kinds of phosphorus oxygen acids or derivatives thereof may be used in combination. The amount of phosphorus oxygen acids or derivatives thereof is preferably 0.01 to 10 mass %, more preferably 0.05 to 5 mass %, and even more preferably 0.1 to 1 mass %, based on the solid content of the reactive adhesive.

[0076] (Leveling agent or defoamer) The reactive adhesive of the present invention may further contain a leveling agent or a defoaming agent in order to improve the appearance of the laminate. Examples of the leveling agent include polyether-modified polydimethylsiloxane, polyester-modified polydimethylsiloxane, aralkyl-modified polymethylalkylsiloxane, polyester-modified hydroxyl-containing polydimethylsiloxane, polyetherester-modified hydroxyl-containing polydimethylsiloxane, acrylic copolymer, methacrylic copolymer, polyether-modified polymethylalkylsiloxane, acrylic acid alkyl ester copolymer, methacrylic acid alkyl ester copolymer, and lecithin. Examples of the defoaming agent include silicone resin, silicone solution, and copolymers of alkyl vinyl ether, alkyl acrylate, and alkyl methacrylate.

[0077] (Epoxy resin) The reactive adhesive of the present invention may contain an epoxy resin. The epoxy resin acts as an acid catcher to suppress hydrolysis of the polyester polyol, improving the resistance to contents. From the viewpoint of releasability, the amount of the epoxy resin is preferably 3 to 40 mass% based on the solid content in the polyol composition.

[0078] The reactive adhesive of the present invention may further contain additives such as antioxidants, ultraviolet absorbers, hydrolysis inhibitors, antifungal agents, thickeners, plasticizers, pigments, fillers, and catalysts for adjusting the curing reaction.

[0079] The viscosity of the reactive adhesive of the present invention is preferably 100 to 10,000 mPa·s at room temperature to 150° C., and more preferably 100 to 10,000 mPa·s at room temperature to 100° C., and when it is 100 to 5,000 mPa·s, it can be used as a solventless type. When the viscosity of the reactive adhesive is higher than the above range, it may be diluted with an organic solvent.

[0080] <<Laminate>> The laminate of the present invention has an adhesive layer between at least two resin layers, which is a cured product of a reactive adhesive. The adhesive layer is cured by laminating the reactive adhesive by a known method such as roll coating, and then curing the reactive adhesive for about 24 hours to one week under conditions of 20 to 60°C to form a cured product. The amount of reactive adhesive applied after drying can be appropriately selected depending on the application, and is usually 1 to 10 g / m 2 and preferably 1 to 2.5 g / m for the solventless type. 2 , Solvent-based 1-6g / m 2 The thickness of the adhesive layer is usually in the range of 1 to 6 μm, preferably in the range of 1 to 2.5 μm for a solventless type and 1 to 6 μm for a solvent type.

[0081] The adhesive layer in the laminate of the present invention exhibits excellent releasability to an alkaline aqueous solution, and the adhesive layer can be detached (separated) from the resin layer of the resin substrate or the like, so that the resin layer can be separated and recovered, and recycled. The alkaline aqueous solution is not particularly limited, and an aqueous solution of a known basic compound can be used, but it is preferably an aqueous solution containing at least one selected from the group consisting of sodium hydroxide and potassium hydroxide, and is, for example, 25 to 120°C and 0.5 to 20 mass%. The alkaline aqueous solution may contain components such as a surfactant, an antifoaming agent, and a compatibilizer from the viewpoints of improving separation and recovery properties, improving compatibility when used as a recycled material, and the like.

[0082] The laminate of the present invention has excellent alkali release properties and, even when the contents contain acid components, alkaline components, volatile components, surfactant components, etc., it does not experience a decrease in strength over time and has excellent resistance to the contents. Therefore, it can be suitably used not only for packaging beverages and food, but also for refill pouches for liquid hair care agents such as shampoo, hair conditioner, and hair rinse, liquid soaps such as body soap and hand soap, liquid detergents for clothing and dishes, finishing agents such as fabric softeners and bleaches, liquid detergents for bathrooms, toilets, and floors, liquid cosmetics, pharmaceuticals, and the like.

[0083] (Resin layer) As the resin layer, for example, a plastic film, a sealant, or the like that is generally used in packaging laminates can be used. Examples of plastic films that can be used include polyester resin films such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), and polylactic acid (PLA); polyolefin resin films such as polyethylene (PE) and polypropylene (PP); polystyrene resin films; polyamide resin films such as nylon 6 and poly-p-xylylene adipamide (MXD6 nylon); polycarbonate resin films; polyacrylonitrile resin films; polyimide resin films; laminates thereof (e.g., nylon 6 / MXD6 / nylon 6, nylon 6 / ethylene-vinyl alcohol copolymer / nylon 6), and mixtures thereof. Among these, those having mechanical strength and dimensional stability are preferred.

[0084] Examples of the sealant include polyethylenes such as low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), and high-density polyethylene (HDPE), acid-modified polyethylene, unoriented polypropylene (CPP), acid-modified polypropylene, copolymerized polypropylene, ethylene-vinyl acetate copolymer, ethylene-(meth)acrylic acid ester copolymer, ethylene-(meth)acrylic acid copolymer, and polyolefin resins such as ionomers. The above plastic films and sealants may have a gas barrier layer which is a vapor-deposited layer of aluminum, silica, alumina, or the like.

[0085] The method for laminating the sealant is not particularly limited, and examples thereof include a method in which an adhesive layer and a sealant film are thermally laminated together (thermal lamination method), and a method in which a sealant resin is melted and extruded onto an adhesive layer, cooled and solidified, and laminated (extrusion lamination method), and can be appropriately selected depending on the application. The thickness of the sealant is not particularly limited, but is preferably 10 to 200 μm, more preferably 15 to 150 μm, from the viewpoints of processability, heat sealability, etc. The sealant may be provided with unevenness with a height difference of 5 to 20 μm to impart slipperiness and tearability.

[0086] The laminate of the present invention may have a printed layer. The printed layer is a layer that forms an arbitrary printed pattern for the purpose of decoration, imparting an aesthetic feel, displaying the contents, expiration date, manufacturer or seller, etc., and also includes a solid printed layer. The printed layer contains a colorant, a dispersant, a binder resin, etc., may be formed of a single layer or multiple layers, and may have alkali release properties.

[0087] The laminate of the present invention may have a primer layer or a known layer having alkali releasability. When the primer layer has alkali releasability, the primer layer is disposed in contact with the resin layer and may have a water-soluble resin or a compound having an acidic group.

[0088] The laminate of the present invention may have a layer of metal foil, paper, etc. An example of the metal foil is aluminum foil. From an economical point of view, the thickness of the metal foil is preferably about 3 to 50 μm. An example of the paper is natural paper, synthetic paper, etc.

[0089] The configuration of the laminate is not particularly limited, but from the viewpoints of resistance to contents and strength when the contents include acid components, alkaline components, volatile components, surfactant components, etc., it is preferable for the laminate to have a configuration having a plastic film, a metal foil or a gas barrier layer, and a sealant. Specific configurations include, but are not limited to, the following: Biaxially oriented polypropylene (OPP) / adhesive layer / CPP, OPP / adhesive layer / AL vapor-deposited CPP, Nylon (NY) / adhesive layer / LLDPE, NY / adhesive layer / CPP, PET / adhesive layer / NY / adhesive layer / LLDPE, NY / adhesive layer / PET / adhesive layer / LLDPE, PET / adhesive layer / AL vapor-deposited PET / adhesive layer / LLDPE, PET / adhesive layer / NY / adhesive layer / CPP, transparent vapor-deposited PET / adhesive layer / NY / adhesive layer / CPP, PET / adhesive layer / AL / adhesive layer / CPP, PET / adhesive layer / AL / adhesive layer / LLDPE, PET / adhesive layer / NY / adhesive layer / AL / adhesive layer / CPP, PET / adhesive layer / AL / adhesive layer / NY / adhesive layer / CPP. EXAMPLES

[0090] The present invention will be described in detail below with reference to examples. The present invention is not limited to the following examples as long as it does not deviate from the gist of the present invention. In addition, unless otherwise specified, "parts" and "%" represent "parts by mass" and "% by mass".

[0091] <Molecular weight and molecular weight distribution> The weight average molecular weight (Mw), number average molecular weight (Mn), and molecular weight distribution (Mw / Mn) were measured by GPC (gel permeation chromatography) and calculated as molecular weights using polystyrene as a standard substance. The measurement conditions are shown below. GPC equipment: Shodex GPC-104 manufactured by Resonac Columns: The following columns were used in series connection: 2 Shodex LF-404 made by Resonac Shodex LF-G made by Resonac Detector: RI (differential refractometer) Measurement conditions: Column temperature 40℃ Eluent: Tetrahydrofuran Flow rate: 0.3mL / min

[0092] <Acid value, hydroxyl value> The acid value and the hydroxyl value were measured according to the method described in JIS K 0070 (1992).

[0093] <Gas Chromatography Mass Spectrometry> The reaction solution of the Diels-Alder addition reaction was analyzed by a gas chromatography mass spectrometer, and the progress of the reaction was confirmed by the decrease in the detection peaks of the rosin acids (b1) and α,β-unsaturated carboxylic acid or its acid anhydride (b2) used as raw materials. The completion of the reaction was confirmed when no change was observed in the decrease in the detection peaks.

[0094] <Synthesis of Resin for Primer Layer> [Synthesis Example 1-1] (Polyurethane Resin P1) In a reactor equipped with a reflux condenser, a dropping funnel, a gas inlet tube, a stirrer, and a thermometer, while introducing nitrogen gas, 115.7 parts of PPA (a polyester polyol made of a polycondensation product of propylene glycol and adipic acid and having a number average molecular weight of 2,000), 11.6 parts of PPG (a polyether polyol made of polypropylene glycol and having a number average molecular weight of 2,000), 19.7 parts of DMPA (2,2-dimethylolpropanoic acid), 81.0 parts of IPDI (isophorone diisocyanate), and 160 parts of NPAC (normal propyl acetate) were charged and reacted at 90°C for 5 hours to obtain a urethane prepolymer solution having an isocyanate group at the end. Next, a mixture of 12.0 parts of AEA (2-(2-aminoethylamino)ethanol) and 280 parts of IPA (isopropyl alcohol) was added dropwise at room temperature over 60 minutes, and then reacted at 70°C for 3 hours to obtain a polyurethane resin solution. To the resulting polyurethane resin solution, 64 parts of NPAC and 56 parts of IPA were added to adjust the solid content, yielding a solution of polyurethane resin P1 with a solid content concentration of 30%, a weight average molecular weight of 25,000, Mw / Mn=3.2, and an acid value of 34.0 mgKOH / g.

[0095] [Synthesis Example 1-2] (Polyurethane Resin P2) A solution of polyurethane resin P2 was obtained in the same manner as in Synthesis Example 1-1, except that the raw materials and the amounts charged were as shown in Table 1.

[0096] [Table 1]

[0097] The abbreviations in Table 1 are shown below. PPA: A polyester polyol with a number average molecular weight of 2,000, made from the polycondensation of propylene glycol and adipic acid. PPG: A polyether polyol made of polypropylene glycol with a number average molecular weight of 2,000. DMPA: 2,2-dimethylolpropanoic acid BD: 1,4-butanediol IPDI: Isophorone diisocyanate NPAC: n-propyl acetate AEA: 2-(2-aminoethylamino)ethanol IPA: Isopropyl alcohol

[0098] <Production of primer layer-forming composition> [Production Example 1-1] (Primer composition S1) 87 parts of polyurethane resin P1 solution, 5 parts of EA (ethyl acetate), 5 parts of IPA, and 3 parts of silica particles (P-73 made by Mizusawa Chemicals: hydrophilic silica particles with an average particle size of 3.8 μm) were stirred and mixed using a disper to obtain primer composition S1.

[0099] [Production Example 1-2] (Primer composition S2) A primer composition S2 was obtained in the same manner as in Production Example 1-1, except that the raw materials and compounding ratios were changed to those shown in Table 2.

[0100] [Table 2]

[0101] The abbreviations in Table 2 are shown below. Maleated rosin solution: A solution of Arakawa Chemical's Malkied No. 32 (acid value 130 mg KOH / g, solids concentration 100%) diluted with ethyl acetate to a solids concentration of 30%.

[0102] <Synthesis of polyester polyol (A)> [Synthesis Example 2-1] (Polyester polyol A1) In a reaction vessel equipped with a stirrer, a thermometer, a reflux condenser, a dropping tank and a nitrogen gas inlet tube, 156 parts of ethylene glycol, 262 parts of neopentyl glycol, 310 parts of isophthalic acid and 272 parts of adipic acid were charged, and the temperature was raised to 250 ° C. while stirring under a nitrogen stream to carry out an esterification reaction. After a predetermined amount of water was distilled and the reaction was continued until the acid value was 5 or less, the pressure was gradually reduced and a deglycolization reaction was carried out at 1 mmHg or less for 5 hours to obtain a polyester polyol. 3.9 parts of trimellitic anhydride were added to 100 parts of this polyester polyol, and the reaction was carried out at 180 ° C. for about 2 hours, and then the mixture was diluted with ethyl acetate until the non-volatile content was 50%, to obtain a solution of partially acid-modified polyester polyol A1 with a number average molecular weight (Mn) of 2,500 and an acid value of 22.1 mgKOH / g.

[0103] [Synthesis Example 2-2] (Polyester polyol A2) In a reaction vessel equipped with a stirrer, a thermometer, a reflux condenser, a dropping tank and a nitrogen gas inlet tube, 114 parts of ethylene glycol, 143 parts of neopentyl glycol, 163 parts of 1,6-hexanediol, 122 parts of terephthalic acid, 244 parts of isophthalic acid and 215 parts of adipic acid were charged, and the mixture was heated to 250 ° C. while stirring under a nitrogen stream to carry out an esterification reaction. After a predetermined amount of water was distilled and the reaction was continued until the acid value was 5 or less, the pressure was gradually reduced and a deglycolization reaction was carried out at 1 mmHg or less for 5 hours to obtain a polyester polyol. 7.4 parts of trimellitic anhydride were added to 100 parts of this polyester polyol, and the mixture was reacted at 180 ° C. for about 2 hours, and then diluted with ethyl acetate until the non-volatile content was 50%, to obtain a solution of partially acid-modified polyester polyol A2 with Mn 5,100 and an acid value of 40.2 mg KOH / g.

[0104] [Synthesis Example 2-3] (Polyester polyol A3) In a reaction vessel equipped with a stirrer, a thermometer, a reflux condenser, a dropping tank and a nitrogen gas inlet tube, 121 parts of ethylene glycol, 135 parts of neopentyl glycol, 128 parts of 1,6-hexanediol, 419 parts of isophthalic acid, 53 parts of adipic acid and 146 parts of sebacic acid were charged, and the mixture was heated to 250°C while stirring under a nitrogen stream to carry out an esterification reaction. After a predetermined amount of water was distilled and the reaction was continued until the acid value was 5 or less, the pressure was gradually reduced and a deglycolization reaction was carried out at 1 mmHg or less for 5 hours to obtain a polyester polyol. Then, 23 parts of isophorone diisocyanate was gradually added, and the reaction was carried out at 150°C for about 2 hours to obtain a polyester polyurethane polyol. 13.2 parts of ethylene glycol bis-anhydrotrimellitate were added to 100 parts of this polyester polyurethane polyol and reacted at 180°C for approximately 2 hours, and then the mixture was diluted with ethyl acetate until the non-volatile content reached 50%, yielding a solution of partially acid-modified polyester polyol A3 with Mn of 10,000 and an acid value of 32.2 mg KOH / g.

[0105] [Synthesis Example 2-4] (Polyester polyol A4) In a reaction vessel equipped with a stirrer, a thermometer, a reflux condenser, a dropping tank and a nitrogen gas inlet tube, 106 parts of ethylene glycol, 177 parts of neopentyl glycol, 101 parts of 1,6-hexanediol, 177 parts of terephthalic acid, 177 parts of isophthalic acid, 62 parts of adipic acid and 201 parts of sebacic acid were charged, and the mixture was heated to 250°C while stirring under a nitrogen stream to carry out an esterification reaction. After a predetermined amount of water was distilled and the reaction was continued until the acid value was 5 or less, the pressure was gradually reduced and a deglycolization reaction was carried out at 1 mmHg or less for 5 hours to obtain a polyester polyol. Then, 5.0 parts of isophorone diisocyanate was gradually added, and the reaction was carried out at 150°C for about 2 hours to obtain a polyester polyurethane polyol. 0.5 parts of trimellitic anhydride was added to 100 parts of this polyester polyurethane polyol and reacted at 180°C for approximately 2 hours, and then the mixture was diluted with ethyl acetate until the solid concentration reached 50%, yielding a solution of partially acid-modified polyester polyol A4 with Mn of 12,000 and an acid value of 2.4 mgKOH / g.

[0106] [Synthesis Example 2-5] (Polyester polyol A5) In a reaction vessel equipped with a stirrer, a thermometer, a reflux condenser, a dropping tank and a nitrogen gas inlet tube, 88 parts of ethylene glycol, 127 parts of neopentyl glycol, 96 parts of 1,6-hexanediol, 65 parts of diethylene glycol, 92 parts of terephthalic acid, 276 parts of isophthalic acid, 108 parts of adipic acid and 149 parts of sebacic acid were charged, and the mixture was heated to 250°C while stirring under a nitrogen stream to carry out an esterification reaction. After a predetermined amount of water was distilled and the reaction was continued until the acid value was 5 or less, the pressure was gradually reduced and a deglycolization reaction was carried out at 1 mmHg or less for 5 hours to obtain a polyester polyol. Then, 28.0 parts of isophorone diisocyanate was gradually added, and the reaction was carried out at 150°C for about 2 hours to obtain a polyester polyurethane polyol. 5.6 parts of ethylene glycol bis-anhydrotrimellitate were added to 100 parts of this polyester polyurethane polyol, and the mixture was allowed to react at 180°C for approximately 2 hours. The mixture was then diluted with ethyl acetate until the solids concentration reached 50%, yielding a solution of partially acid-modified polyester polyol A5 with an Mn of 19,100 and an acid value of 14.7 mg KOH / g.

[0107] [Synthesis Example 2-6] (Polyester polyol A6) In a reaction vessel equipped with a stirrer, a thermometer, a reflux condenser, a dropping tank and a nitrogen gas inlet tube, 89 parts of ethylene glycol, 128 parts of neopentyl glycol, 97 parts of 1,6-hexanediol, 65 parts of diethylene glycol, 93 parts of terephthalic acid, 279 parts of isophthalic acid, 136 parts of adipic acid and 113 parts of sebacic acid were charged, and the mixture was heated to 250°C while stirring under a nitrogen stream to carry out an esterification reaction. After a predetermined amount of water was distilled and the reaction was continued until the acid value was 5 or less, the pressure was gradually reduced and a deglycolization reaction was carried out at 1 mmHg or less for 5 hours to obtain a polyester polyol. Then, 30.0 parts of isophorone diisocyanate was gradually added, and the reaction was carried out at 150°C for about 2 hours to obtain a polyester polyurethane polyol. 3.9 parts of ethylene glycol bis-anhydrotrimellitate were added to 100 parts of this polyester polyurethane polyol and reacted at 180°C for approximately 2 hours. The mixture was then diluted with ethyl acetate until the solids concentration reached 50%, yielding a solution of partially acid-modified polyester polyol A6 with Mn of 22,600 and an acid value of 10.0 mg KOH / g.

[0108] [Synthesis Example 2-7] (Polyester polyol A7) A reaction vessel equipped with a stirrer, a thermometer, a reflux condenser, a dropping tank and a nitrogen gas inlet tube was charged with 124 parts of ethylene glycol, 138 parts of neopentyl glycol, 131 parts of 1,6-hexanediol, 214 parts of isophthalic acid, 243 parts of adipic acid and 149 parts of sebacic acid, and the mixture was heated to 250 ° C. while stirring under a nitrogen stream to carry out an esterification reaction. After a predetermined amount of water was distilled and the reaction was continued until the acid value was 5 or less, the pressure was gradually reduced and a deglycolization reaction was carried out at 1 mmHg or less for 5 hours to obtain a polyester polyol. 12.8 parts of ethylene glycol bis anhydro trimellitate were added to 100 parts of this polyester polyol, and the mixture was reacted at 180 ° C. for about 2 hours, and then diluted with ethyl acetate until the solid content concentration was 50%, to obtain a solution of partially acid-modified polyester polyol A7 with Mn 10,500 and acid value 31.3 mg KOH / g.

[0109] [Synthesis Example 2-8] (Polyester polyol A8) A reaction vessel equipped with a stirrer, a thermometer, a reflux condenser, a dropping tank and a nitrogen gas inlet tube was charged with 122 parts of ethylene glycol, 137 parts of neopentyl glycol, 129 parts of 1,6-hexanediol, 190 parts of isophthalic acid, 306 parts of adipic acid and 116 parts of sebacic acid, and the mixture was heated to 250 ° C. while stirring under a nitrogen stream to carry out an esterification reaction. After a predetermined amount of water was distilled and the reaction was continued until the acid value was 5 or less, the pressure was gradually reduced and a deglycolization reaction was carried out at 1 mmHg or less for 5 hours to obtain a polyester polyol. 12.8 parts of ethylene glycol bis anhydro trimellitate was added to 100 parts of this polyester polyol, and the mixture was reacted at 180 ° C. for about 2 hours, and then diluted with ethyl acetate until the solid content concentration was 50%, to obtain a solution of partially acid-modified polyester polyol A8 with Mn 11,000 and acid value 31.0 mg KOH / g.

[0110] [Table 3]

[0111] <Synthesis of rosin-modified resin (B)> [Synthesis Example 3-1] (Rosin-modified resin B1) 229 parts of gum rosin and 74 parts of maleic anhydride were charged into a reaction vessel equipped with a stirrer, a thermometer, a reflux condenser and a nitrogen gas inlet tube, and the mixture was heated to 180°C for 1 hour while stirring under a nitrogen stream to obtain a reaction mixture. The reaction mixture was then analyzed by gas chromatography mass spectrometry to confirm that the Diels-Alder addition reaction had been completed. Next, 215 parts of benzoic acid, 60 parts of pentaerythritol, 27 parts of glycerin, 321 parts of neopentyl glycol, and 0.05 parts of p-toluenesulfonic acid hydrate as a catalyst were added to the reaction mixture, and the mixture was reacted at 240°C for 6 hours. The mixture was then diluted with ethyl acetate until the solid content concentration reached 50%, to obtain a solution of rosin-modified resin B1 with a weight average molecular weight (Mw) of 6,500, a number average molecular weight (Mn) of 1,100, Mw / Mn=5.9, an acid value of 61.1 mgKOH / g, and a hydroxyl value of 244.0 mgKOH / g.

[0112] [Synthesis Example 3-2] (Rosin-modified resin B2) 288 parts of gum rosin and 124 parts of maleic anhydride were charged into a reaction vessel equipped with a stirrer, a thermometer, a reflux condenser and a nitrogen gas inlet tube, and the mixture was heated to 180°C for 1 hour while stirring under a nitrogen stream to obtain a reaction mixture. The reaction mixture was then subjected to gas chromatography mass spectrometry to confirm that the Diels-Alder addition reaction had been completed. Next, 348 parts of benzoic acid, 161 parts of pentaerythritol, 78 parts of glycerin, and 0.05 parts of p-toluenesulfonic acid hydrate as a catalyst were added to the reaction mixture, and the mixture was reacted at 240°C for 9 hours. The mixture was then diluted with ethyl acetate until the solid content concentration reached 50%, to obtain a solution of rosin-modified resin B2 with Mw 2,2000, Mn 1,200, Mw / Mn = 18.3, acid value 35.2 mgKOH / g, and hydroxyl value 51.1 mgKOH / g.

[0113] [Synthesis Example 3-3] (Rosin-modified resin B3) A reaction vessel equipped with a stirrer, a thermometer, a reflux condenser and a nitrogen gas inlet tube was charged with 619 parts of gum rosin and 151 parts of maleic anhydride, and heated to 180°C for 1 hour while stirring under a nitrogen stream to obtain a reaction mixture. The reaction mixture was then subjected to gas chromatography mass spectrometry to confirm that the Diels-Alder addition reaction had been completed. Next, 216 parts of neopentyl glycol, 14 parts of ethylene glycol, and 0.05 parts of p-toluenesulfonic acid hydrate as a catalyst were added to the reaction mixture, and the mixture was reacted at 240°C for 8 hours. The mixture was then diluted with ethyl acetate until the solid content concentration reached 50%, to obtain a solution of rosin-modified resin B3 with Mw 6,400, Mn 900, Mw / Mn = 7.1, acid value 70.2 mgKOH / g and hydroxyl value 72.1 mgKOH / g.

[0114] [Synthesis Example 3-4] (Rosin-modified resin B4) 230 parts of gum rosin and 75 parts of maleic anhydride were charged into a reaction vessel equipped with a stirrer, a thermometer, a reflux condenser and a nitrogen gas inlet tube, and the mixture was heated to 180°C for 1 hour while stirring under a nitrogen stream to obtain a reaction mixture. The reaction mixture was then analyzed by gas chromatography mass spectrometry to confirm that the Diels-Alder addition reaction had been completed. Next, 217 parts of benzoic acid, 62 parts of pentaerythritol, 28 parts of glycerin, 285 parts of neopentyl glycol, 28 parts of ethylene glycol, and 0.05 parts of p-toluenesulfonic acid hydrate as a catalyst were added to the reaction mixture, and the mixture was reacted at 240°C for 6 hours. The mixture was then diluted with ethyl acetate until the solid content concentration reached 50%, to obtain a solution of rosin-modified resin B4 with Mw4,700, Mn810, Mw / Mn=5.8, acid value 52.6mgKOH / g and hydroxyl value 257.4mgKOH / g.

[0115] [Synthesis Example 3-5] (Rosin-modified resin B5) A reaction vessel equipped with a stirrer, a thermometer, a reflux condenser and a nitrogen gas inlet tube was charged with 630 parts of gum rosin and 153 parts of maleic anhydride, and heated to 180°C for 1 hour while stirring under a nitrogen stream to obtain a reaction mixture. The reaction mixture was then subjected to gas chromatography mass spectrometry to confirm that the Diels-Alder addition reaction had been completed. Next, 196 parts of neopentyl glycol, 21 parts of ethylene glycol, and 0.05 parts of p-toluenesulfonic acid hydrate as a catalyst were added to the reaction mixture, and the mixture was reacted at 240°C for 8 hours. The mixture was then diluted with ethyl acetate until the solid content concentration reached 50%, to obtain a solution of rosin-modified resin B5 with Mw 5,300, Mn 890, Mw / Mn = 6.0, acid value 65.0mgKOH / g and hydroxyl value 59.2mgKOH / g.

[0116] [Synthesis Example 3-6] (Rosin-modified resin B6) 282 parts of gum rosin and 107 parts of maleic anhydride were charged into a reaction vessel equipped with a stirrer, a thermometer, a reflux condenser and a nitrogen gas inlet tube, and the mixture was heated to 180°C for 1 hour while stirring under a nitrogen stream to obtain a reaction mixture. The reaction mixture was then subjected to gas chromatography mass spectrometry to confirm that the Diels-Alder addition reaction had been completed. Next, 380 parts of benzoic acid, 122 parts of pentaerythritol, 66 parts of glycerin, 44 parts of ethylene glycol, and 0.05 parts of p-toluenesulfonic acid hydrate as a catalyst were added to the reaction mixture, and the mixture was reacted at 240°C for 10 hours. The mixture was then diluted with ethyl acetate until the solid content concentration reached 50%, to obtain a solution of rosin-modified resin B6 with Mw 15,000, Mn 1,100, Mw / Mn = 13.6, acid value 25.2 mgKOH / g, and hydroxyl value 34.0 mgKOH / g.

[0117] [Synthesis Example 3-7] (Rosin-modified resin B7) 282 parts of gum rosin and 107 parts of maleic anhydride were charged into a reaction vessel equipped with a stirrer, a thermometer, a reflux condenser and a nitrogen gas inlet tube, and the mixture was heated to 180°C for 1 hour while stirring under a nitrogen stream to obtain a reaction mixture. The reaction mixture was then analyzed by gas chromatography mass spectrometry to confirm that the Diels-Alder addition reaction had been completed. Next, 379 parts of benzoic acid, 134 parts of pentaerythritol, 55 parts of glycerin, 44 parts of ethylene glycol, and 0.05 parts of p-toluenesulfonic acid hydrate as a catalyst were added to the reaction mixture, and the mixture was reacted at 240°C for 10 hours. The mixture was then diluted with ethyl acetate until the solid content concentration reached 50%, to obtain a solution of rosin-modified resin B7 with Mw 17,200, Mn 1,100, Mw / Mn = 15.6, acid value 19.9 mgKOH / g, and hydroxyl value 28.0 mgKOH / g.

[0118] [Synthesis Example 3-8] (Rosin-modified resin B8) A reaction vessel equipped with a stirrer, a thermometer, a reflux condenser, and a nitrogen gas inlet tube was charged with 854 parts of polymerized rosin B-140 (manufactured by Xinzhou (Wu Ping) Hayashi Chemical Co., Ltd.), 139 parts of pentaerythritol, and 7 parts of glycerin, and the mixture was reacted at 250°C for 2 hours with stirring under a nitrogen stream, and then further reacted at 280°C for 10 hours to obtain a solution of rosin modified resin B8 with Mw 3,200, Mn 610, Mw / Mn = 5.2, acid value 12.3 mg KOH / g, and hydroxyl value 39.1 mg KOH / g.

[0119] (Rosin modified resin B9) A solution of Pine Crystal KR-120 (acid value 320 mg KOH / g, hydroxyl value 0 mg KOH / g, solids concentration 100%) manufactured by Arakawa Chemical Industry Co., Ltd. was diluted with ethyl acetate to a solids concentration of 50%, to prepare a solution of rosin modified resin B9.

[0120] [Table 4]

[0121] <Production of polyisocyanate> [Production Example 2-1] (Polyisocyanate C1) BASONAT HB 100 (a biuret type polyisocyanate derived from hexamethylene diisocyanate (hereinafter, HDI), manufactured by BASF) was diluted with ethyl acetate to adjust the nonvolatile content to 40% and NCO% to 9.4%, to obtain a solution of polyisocyanate C1.

[0122] [Production Example 2-2] (Polyisocyanate C2) Takenate D-110NB (trimethylolpropane adduct type polyisocyanate derived from xylylene diisocyanate (hereinafter, XDI), manufactured by Mitsui Chemicals) was diluted with ethyl acetate to adjust the non-volatile content to 50% and NCO% to 7.9%, to obtain a solution of polyisocyanate C2.

[0123] [Production Example 2-3] (Polyisocyanate C3) VESTANAT T1890 / 100 (nurate type polyisocyanate derived from isophorone diisocyanate (hereinafter, IPDI), manufactured by Evonik Corporation) was diluted with ethyl acetate to adjust the nonvolatile content to 50% and NCO% to 8.7%, to obtain a solution of polyisocyanate C3.

[0124] [Production Example 2-4] (Polyisocyanate C4) Takenate D-103H (trimethylolpropane adduct type polyisocyanate derived from tolylene diisocyanate (hereinafter, TDI), manufactured by Mitsui Chemicals) was diluted with ethyl acetate to adjust the non-volatile content to 50% and NCO% to 8.5%, to obtain a solution of polyisocyanate C4.

[0125] [Production Example 2-5] (Polyisocyanate C5) Millionate MR-200 (a polymeric polyisocyanate derived from diphenylmethane diisocyanate (hereinafter, MDI), manufactured by Tosoh Corporation) was diluted with ethyl acetate to adjust the non-volatile content to 25% and NCO% to 7.9%, to obtain a solution of polyisocyanate C5.

[0126] <Adhesive manufacturing> [Examples 1 to 22 and Comparative Examples 1 to 4] Adhesives T1 to T26 The obtained polyester polyol solution, rosin modified resin solution, epoxy resin, and polyisocyanate solution were mixed in the ratios shown in Table 5, and ethyl acetate was added to obtain adhesives T1 to T26 with a non-volatile content of 30 mass %.

[0127] [Table 5]

[0128] The abbreviations in Table 5 are as follows. Epoxy resin solution E1: Mitsubishi Chemical's JER1002 (100% solids) diluted with ethyl acetate to a solids concentration of 50%.

[0129] <Manufacture of Laminate> In the manufacture of the laminates described below, the printing ink used was Rio Alpha R681 White (manufactured by Toyo Ink Co., Ltd.) diluted with a mixed solvent of ethyl acetate / isopropyl alcohol (mass ratio 70 / 30) to a viscosity of 15 seconds (25°C, Zahn cup #3 (Rigo Co., Ltd.)). Similarly, the primer composition was diluted with a mixed solvent of ethyl acetate / isopropyl alcohol (mass ratio 70 / 30) to a viscosity of 15 seconds (25°C, Zahn cup #3 (Rigo Co., Ltd.)).

[0130] [Example 101] Laminate F1 The above printing ink was printed on the entire surface of a NY film (thickness 15 μm) using a gravure printing machine equipped with a gravure plate with a plate depth of 30 μm, and dried at 50° C. to obtain a print (NY / printed layer). The thickness of the printed layer was adjusted to 1.5 μm. Next, adhesive T1 was applied onto the printed layer using a dry laminator until the coating amount was 3.5 g / m2. 2 After coating and drying so that the thickness became 12 μm, the resultant was bonded to the AL surface of an AL-deposited PET sheet (thickness: 12 μm) to obtain an intermediate laminate (NY / printed layer / adhesive layer / AL-deposited PET sheet). Furthermore, adhesive T1 was applied to the PET surface of the intermediate laminate in the same manner as described above, and after drying, it was laminated with an LLDPE film (thickness 150 μm) and kept at 40°C for 4 days to harden the adhesive, thereby obtaining laminate F1 (NY / printed layer / adhesive layer / AL-vapor-deposited PET / adhesive / LLDPE).

[0131] [Example 102] Laminate F2 The diluted solution of primer composition S1 and then the printing ink were printed on the entire surface of a NY film (thickness 15 μm) using a gravure printing machine equipped with a gravure plate with a plate depth of 30 μm, and dried at 50° C. to obtain a print (NY / primer layer / printed layer). The thicknesses of the primer layer and the printed layer were each adjusted to 1.5 μm. Next, adhesive T1 was applied onto the printed layer using a dry laminator until the coating amount was 3.5 g / m2. 2After coating and drying so that the thickness became 12 μm, the laminate was attached to the AL surface of an AL-deposited PET sheet (thickness: 12 μm) to obtain an intermediate laminate (NY / primer layer / printed layer / adhesive layer / AL-deposited PET sheet). Furthermore, adhesive T1 was applied to the PET surface of the intermediate laminate in the same manner as described above, and after drying, it was laminated with an LLDPE film (thickness 150 μm) and kept at 40°C for 4 days to harden the adhesive, thereby obtaining laminate F2 (NY / primer layer / printed layer / adhesive layer / AL-vapor-deposited PET / adhesive / LLDPE).

[0132] [Example 103] Laminate F3 Except for changing the primer composition to the content shown in Table 6, the same procedure as in Example 102 was carried out to obtain a laminate F3.

[0133] [Examples 104 to 124, Comparative Examples 101 to 104] Laminates F4 to F28 Except for changing the adhesive to the one shown in Table 6, the same procedure as in Example 101 was carried out to obtain laminates F4 to F28.

[0134] <Evaluation of the laminate> The obtained laminate was subjected to the following evaluations, and the results are shown in Table 6.

[0135] [Initial adhesive strength] The obtained laminate was cut into a size of 15 mm x 300 mm to prepare a test piece. Using a tensile tester, T-type peeling was performed at a peeling speed of 30 cm / min under conditions of 20°C and 65% relative humidity, and the adhesive strength (N / 15 mm) between the AL-deposited PET and LLDPE was measured. The practical range of adhesive strength is 4 N / 15 mm or more.

[0136] [Resistance to contents over time] The obtained laminate was cut into two pieces measuring 9 cm x 13 cm, and placed so that the LLDPE was on the inside to prepare a pouch filled with conditioner. The obtained pouch was stored at 60°C for two weeks, after which the contents were removed and the pouch was cut into a size of 15 mm to prepare a test piece. The adhesive strength (N / 15 mm) between the AL-deposited PET / LLDPE was measured in the same manner as for the initial adhesive strength. The practical range of adhesive strength is 3 N / 15 mm or more.

[0137] [Change in adhesive strength] The rate of change in adhesive strength from the above [initial adhesive strength] to [resistance to contents over time] was calculated using the following formula. Percentage change: [(Adhesive strength with resistance to contents over time) - (Initial adhesive strength)] / (Initial adhesive strength) x 100

[0138] [Alkaline release] The obtained laminate was cut into a size of 1.5 cm x 1.5 cm to prepare a test piece. 45 g of test piece was placed in a 2000 ml flask, 1500 ml of 2% aqueous sodium hydroxide solution was added, and the mixture was stirred at 70°C and 200 rpm for 2 hours. After stirring was completed, 30 films containing LLDPE were randomly sampled and their thickness was measured. From the measured thickness, the number of samples in which the LLDPE and the AL-deposited PET did not peel off was counted and evaluated according to the following criteria. S(Excellent): 0~1 piece A(Good): 2-3 sheets B (acceptable): 4~6 pieces C (impossible): 7 or more pieces

[0139] [Table 6]

[0140] According to the above evaluation results, the reactive adhesive of the present invention, which uses a polyol composition containing, in a specified ratio, polyester polyol (A) in which the proportion of aromatic rings in the polybasic acid or its derivative is 35% by mass or more, and rosin-modified resin (B) having a hydroxyl value and acidic groups, exhibited excellent alkali release properties (recyclability) and resistance to contents over time. On the other hand, the comparative examples that did not satisfy any one of the following points, that is, the use of a polyester polyol (A) having a proportion of a polybasic acid or its derivative having an aromatic ring of 35 mass% or more, the use of a rosin-modified resin (B) having an acid group and an acidic group, and the (B) / (A) ratio being within the specified range, all showed a decrease in adhesive strength over time and showed values ​​outside the practical range.

Claims

1. A reactive adhesive comprising a polyol composition and a polyisocyanate, The polyol composition comprises a polyester polyol (A) and a rosin-modified resin (B) having a hydroxyl group and an acidic group, the polyester polyol (A) is made from a polybasic acid or a derivative thereof and a polyhydric alcohol as essential raw materials, and the proportion of a polybasic acid or a derivative thereof having an aromatic ring in the polybasic acid or the derivative thereof is 35 mass% or more; A reactive adhesive, wherein the mass ratio ((B) / (A)) of the rosin-modified resin (B) to the polyester polyol (A) is 0.03 to 1.

5.

2. The acid value (AV) of the rosin-modified resin (B) Ｂ ) and hydroxyl value (OHV Ｂ 2. The reactive adhesive according to claim 1 , wherein the value of Formula (1): AV Ｂ (mgKOH / g) / OHV Ｂ (mgKOH / g)=0.25~1.0

3. The acid value (AV Ａ ) and the acid value (AV Ｂ 2. The reactive adhesive according to claim 1 , wherein the value of Formula 2: AV Ａ (mgKOH / ') / AV Ｂ (mgKOH / g)=0.2~1.7

4. The reactive adhesive according to claim 1, wherein the rosin-modified resin (B) comprises a reactant having an ester bond formed by a reaction between a carboxylic acid in a compound obtained by a Diels-Alder reaction between an organic acid having a conjugated double bond, contained in a rosin acid (b1), and an α,β-unsaturated carboxylic acid or an acid anhydride thereof (b2), and a polyol (b3).

5. The reactive adhesive according to claim 1, wherein the polyester polyol (A) has a number average molecular weight of 5,000 to 20,000.

6. The reactive adhesive according to claim 1 , wherein the polyisocyanate comprises at least one selected from the group consisting of aliphatic polyisocyanates and araliphatic polyisocyanates.

7. A cured product obtained by curing the reactive adhesive according to claim 1.

8. A laminate comprising at least two resin layers and an adhesive layer between them, the adhesive layer being the cured product according to claim 7.

9. A packaging material using the laminate according to claim 8.

10. A package using the packaging material according to claim 9.

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