JP5252803B2 - Two-component curable adhesive - Google Patents

Description

  The present invention relates to a two-component curable adhesive for laminating which can be coated with a high nonvolatile content. More specifically, the present invention relates to a two-component curable adhesive for laminating that can be used for manufacturing flexible packaging used for packaging of foods and the like and can be coated with a high nonvolatile content.

  Conventionally, various methods such as dry lamination, sandwich lamination, extrusion coating, coextrusion, etc. have been used for the production of flexible packaging materials, but solvent-based adhesives that can use most plastic and metal foils as substrates. Dry lamination using occupies 90%.

  As the solvent adhesive for dry lamination, a two-component curable polyurethane adhesive is mainly used. Typical main agents in practical use include polyester polyols having terminal hydroxyl groups obtained from polyols and dicarboxylic acids, polyester polyurethane polyols obtained from polyester polyols and organic diisocyanates, and polyether polyurethanes obtained from polyether polyols and organic diisocyanates. Polyester, a polyether polyether polyurethane polyol obtained from a mixture of a polyester polyol and a polyether polyol and an organic diisocyanate may be mentioned, both of which are bifunctional and trifunctional polyols. As these polyols, those having a number average molecular weight of 15,000 or more are mainly used.

  On the other hand, as a curing agent, an adduct obtained by adding 3 mol of organic diisocyanate to 1 mol of trimethylolpropane, a burette obtained by reacting 1 mol of water with 3 mol of organic diisocyanate, or 3 mol of Polyfunctional organic polyisocyanate having a bonding form such as isocyanurate obtained by polymerization of organic diisocyanate is used, and it is also obtained by reacting polyisocyanate with polyester polyol, polyether polyol or, if necessary, low molecular polyol. Polyurethane polyisocyanate compounds are mainly used.

The above main agent and curing agent are generally mixed at a ratio of hydroxyl group / isocyanate group equivalent ratio of 1/1 to 1/3.
In addition, these adhesives are used by adjusting the non-volatile content of the adhesive at the time of coating to 30% by weight by adding a diluent such as ethyl acetate according to the composition of the adhesive in order to ensure appropriate coating properties. Is done.
On the other hand, in order to dry such a diluted solvent, it must be heated and dried in a drying furnace. However, in recent years, from the viewpoint of environmental protection, it is necessary to avoid discharging the solvent into the atmosphere, and the dried solvent is recovered. However, if it is necessary to incinerate and the production volume is increased, it is necessary to add expensive equipment such as a solvent recovery device and an incinerator, which is expensive to maintain and causes an increase in cost. There is a strong demand for high solid adhesives that can be used with conventional equipment even if the production volume increases, and that the amount of dilution with solvents is reduced to improve the working environment.

  However, the existing high solid type adhesive is merely a reduction in the molecular weight of a conventional polyol having a molecular weight of tens of thousands, and the adhesive can be applied with a nonvolatile content of 40% by weight or more. At present, an adhesive having high adhesive strength and high adhesive strength in a normal state and excellent in boil resistance has not yet been obtained.

JP 2000-290631 A

Therefore, it is necessary to design an adhesive resin that has a non-volatile content of 40% by weight or more when applied and that has good coatability, initial adhesion, and adhesion to various adherends.
In view of the above problems, the present invention provides an adhesive that is optimal for dry lamination. Also, a two-component curable adhesive that can be applied with a non-volatile content of 40% by weight or more, has a high initial adhesive strength immediately after lamination, a high normal adhesive strength, and excellent boil resistance. To do.

  As a result of various studies to solve the above problems, the present inventors have identified a specific polyhydric alcohol as the polyol component of the polyester polyol, which is the main component of the two-part curable adhesive, and a monofunctional fatty acid as the acid component. The present invention has been reached by controlling the molecular weight.

That is, the present invention is a two-component curable adhesive comprising [1] polyester polyol and polyisocyanate as a curing agent, wherein the polyester polyol has a number average molecular weight of 5,000 to 10 The polyester polyol can be obtained by reacting a polyol component with a mixture of a monofunctional fatty acid containing a straight or branched hydrocarbon group having 8 or more carbon atoms and a dibasic acid. There is a polyhydric alcohol 0.5-3% by weight in the polyol component has three or more hydroxyl groups, Ru Oh glycolic more than 30 wt% in the remaining polyol component having a side-chain alkyl group, two It is a liquid curable adhesive.

Further, the present invention is [2] Polyester polyol is a two-component curable adhesive according to SL above that Yusuke average 1.9 to 2.1 hydroxyl groups per molecule [1].

  Moreover, this invention is a two-component curable adhesive as described in said [1] or said [2] whose monofunctional fatty acid is a fatty acid derived from natural fats and oils.

  Furthermore, the present invention provides the two-component curable adhesive according to any one of [1] to [3], wherein the nonvolatile content is 40% by weight or more and the Zahn cup viscosity at 25 ° C. is 15 to 25 seconds. is there.

  The present invention can apply an adhesive with a nonvolatile content of 40% by weight or more, has a high initial adhesive strength immediately after lamination, has a high normal adhesive strength, and is excellent in boil resistance. Can be provided.

  The two-part curable adhesive of the present invention is a polyhydric alcohol in which 0.5 to 3% by weight in the polyol component has 3 or more hydroxyl groups, and 30% by weight or more in the remaining polyol component is a side chain alkyl group. And a number average molecular weight obtained by reacting a mixture of a monofunctional fatty acid containing a straight chain or branched chain hydrocarbon group having 8 or more carbon atoms and a dibasic acid as an acid component with a polyol mixture which is a glycol having a number of 5,000. It is characterized by being a two-component curable adhesive using a polyester polyol of 10,000 to 10,000 and a polyisocyanate as a curing agent.

  Any known glycol can be used as the glycol having a side chain alkyl group as the polyol component used in the present invention. For example, propylene glycol, 1,3-butanediol, 2-methyl-1,3-propanediol, 3-methyl-1,5-pentanediol, neopentyl glycol, dimethylbutanediol, butylethylpropanediol, dipropylene glycol, Tripropylene glycol is mentioned. In addition, any of these glycols having a side chain alkyl chain can be used alone or as a mixture of two or more, and is preferably 30% by weight or more in the polyol component. If it is less than 30% by weight, the solubility in a solvent is lowered, and coating with a nonvolatile content of 40% by weight or more becomes impossible.

  Examples of the polyol composed of a polyhydric alcohol having 3 or more hydroxyl groups as the polyol component used in the present invention include trivalent or higher polyols such as trimethylolpropane, glycerin, trimethylolethane, pentaerythritol carbitol, and sorbitol. It is done. Any of these polyols having three or more hydroxyl groups can be used alone or as a mixture of two or more, and it is preferably 0.5 to 3% by weight in the polyol component. If it exceeds 3% by weight, the number of cross-linking points in the polyester polyol will increase, so that the solubility in the solvent will be reduced, and coating with a non-volatile content of 40% by weight or more will not be possible. Decreases. Moreover, the crosslinking point in polyester polyol decreases that it is less than 0.5 weight%, and adhesive strength falls.

  Further, as the polyol other than the glycol having a side chain alkyl group or a polyol having three or more hydroxyl groups, any known glycol can be used. For example, ethylene glycol, 1,3-propanediol, 1 , 4-butanediol, 1,5-pentanediol, 1,6-hexanediol, diethylene glycol, triethylene glycol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, polycaprolactone diol, dimer diol, bisphenol A Polyesters obtained by ring-opening polymerization reaction of cyclic ester compounds such as propiolactone, butyrolactone, ε-caprolactone, δ-valerolactone, β-methyl-δ-valerolactone, etc. Kind, and the like.

  The monofunctional fatty acid is not limited as long as it contains a straight or branched hydrocarbon group having 8 or more carbon atoms, and includes caprylic acid, capric acid, octylic acid, lauric acid, palmitic acid, stearic acid and the like. Further, castor oil fatty acid, soybean oil fatty acid and the like, which are fatty acids derived from natural fats and oils, may be mentioned. Palm oil fatty acid having a low content of unsaturated fatty acid is preferred because the resulting polyester polyol can be less colored and inexpensive.

As the dibasic acid, any raw material can be used as long as it is known. For example, succinic acid, adipic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid, maleic anhydride, fumaric acid, 1,3-cyclopentanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, terephthalic acid, isophthalic acid, phthalic acid 1,4-naphthalenedicarboxylic acid, 2,5-naphthalenedicarboxylic acid, and 2,6-naphthalenedicarboxylic acid. These can be used alone or in a mixture of two or more.
In addition, polybasic acids such as dimer acid, trimellitic acid and pyromellitic acid can be used singly or in a mixture of two or more, as long as the effects of the present invention are not impaired.

  The polyester polyol of the present invention needs to have an average of 1.9 to 2.1 hydroxyl groups per molecule. When the hydroxyl group is less than 1.9, the crosslinking density is lowered and the adhesiveness such as heat resistance is lowered. On the other hand, when the hydroxyl group exceeds 2.1, the crosslinking density increases too much and the adhesiveness decreases.

  Further, the polyester polyol of the present invention needs to have a number average molecular weight of 5,000 to 10,000. When the number average molecular weight is less than 5,000, the initial adhesive strength is lowered. On the other hand, when the number average molecular weight exceeds 10,000, coating with a nonvolatile content of 40% by weight or more becomes impossible.

  The two-part curable adhesive of the present invention preferably has a Zahn cup viscosity (No. 3) at a temperature of 25 ° C. for 15 to 25 seconds when the nonvolatile content during coating is 40% by weight or more. If it is out of this range, the coatability becomes worse.

  These polyester polyols can also be used by blending the above-mentioned polyhydric alcohol or polyether polyol components.

(Polyisocyanate component)
The polyisocyanate that is a curing agent used in the present invention is, for example, tolylene diisocyanate, diphenylmethane diisocyanate, orthotolidine diisocyanate, naphthalene diisocyanate, metaxylylene diisocyanate, hexamethylene diisocyanate, dimer acid diisocyanate, dicyclohexylmethane diisocyanate, methylcyclohexane diisocyanate, trimethyl. Examples include hexamethylene diisocyanate, phenylene diisocyanate, triphenylmethane triisocyanate, diphenyl ether-4,4′-diisocyanate, isophorone diisocyanate, isopropylidenebis-4-cyclohexyl isocyanate, and the like.

  Moreover, what has at least 2 isocyanate group in 1 molecule, such as an adduct body of the above-mentioned diisocyanate and a polyol, the isocyanurate body of the said diisocyanate, a burette body, and an allophanate body, is mentioned. For example, an adduct obtained by adding 3 mol of diisocyanate to 1 mol of trimethylolpropane, a burette obtained by reacting 1 mol of water with 3 mol of diisocyanate, or an isocyanate obtained by polymerization of 3 mol of diisocyanate. A polyfunctional organic polyisocyanate having a bonding form such as nurate is used, and a polyurethane polyisocyanate compound obtained by reacting a polyisocyanate with a polyester polyol, a polyether polyol or, if necessary, a low molecular weight polyol can be used.

  The ratio of the hydroxyl group attributed to the polyol component such as polyester polyol having a number average molecular weight of 5,000 to 10,000 and the isocyanate group attributed to the polyisocyanate component is such that OH: NCO is 1: 1 to 1: 4. Preferably, it is about 1: 1 to 1: 3.

  Moreover, an adhesion promoter can also be added to the two-component curable adhesive of the present invention after the synthesis of the polyol component. Examples of the adhesion promoter include silane coupling agents, titanate coupling agents, aluminate coupling agents, and epoxy resins.

  Examples of the silane coupling agent include 3-glycidoxypropyltrimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, vinyltriethoxysilane, vinyl tris (2-methoxyethoxy) silane, 3-methacryloxypropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N-2- (aminoethyl) -3-aminopropyltrimethoxysilane, N-2- (aminoethyl) -3-aminopropylmethyldimethoxysilane , 3-mercaptopropyltrimethoxysilane, 3-chloropropyltrimethoxysilane and the like.

  Examples of titanate coupling agents include tetraisopropyl titanate, tetra-n-butoxy titanate, tetrastearyl titanate, polyhydroxy titanium stearate, triisopropyl stearyl titanate, tri-n-butoxy titanium monostearate, butyl titanate dimer, etc. Can be mentioned.

  Examples of the aluminate coupling agent include alkyl acetoacetate aluminum diisopropylate.

  Epoxy resins include phenol novolak type epoxy resins, orthocresol novolak type epoxy resins and other epoxy and aldehyde novolak resins epoxidized, bisphenol A, bisphenol B, bisphenol F, bisphenol S and other diglycidyl Glycidyl ester type epoxy resin obtained by the reaction of polybasic acids such as ether and phthalic acid dimer acid and epichlorohydrin, polyamine such as diaminodiphenylmethane and isocyanuric acid and epichlorohydrin, and olefin bond There are linear aliphatic epoxy resins obtained by oxidation with peracid such as peracetic acid, and alicyclic epoxy resins, and any number of these can be used in combination.

  Furthermore, the two-component curable adhesive of the present invention can be used in combination with a known acid anhydride as a method for improving the acid resistance of the adhesive layer. For example, succinic acid anhydride, phthalic acid anhydride, Himic Acid anhydride, het acid anhydride, maleic acid anhydride, tetrahydrophthalic acid anhydride, hexahydraphthalic acid anhydride, tetrabromophthalic acid anhydride, tetrachlorophthalic acid anhydride, trimellitic acid anhydride, pyromellitic acid Anhydride, benzophenotetracarboxylic anhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 5- (2,5-oxotetrahydrofuryl) -3-methyl-3-cyclohexene-1,2 -Dicarboxylic anhydride, a styrene maleic anhydride copolymer, etc. are mentioned.

  The two-component curable adhesive of the present invention is used by mixing a polyol component having a nonvolatile content of 60 to 80% by weight and a polyisocyanate component having a nonvolatile content of approximately 70 to 100% by weight and diluting with a diluent solvent as necessary. To do. The non-volatile content of the two-component curable adhesive of the present invention is preferably about 40 to 60% by weight at the time of preparation.

  Additives such as a leveling agent, an antifoaming agent, an antioxidant, and an ultraviolet absorber can be further added to the two-component curable adhesive of the present invention.

  The two-component curable adhesive of the present invention is made of stretched, non-stretched, metal-deposited polypropylene, polyethylene terephthalate, nylon, polyethylene, or other plastic films, plastic films deposited with aluminum, alumina, silica-deposited plastic films, or aluminum. It is used when creating a laminate with a foil of stainless steel, iron, copper or the like.

  Hereinafter, the contents and effects of the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples. In the examples, “parts” and “%” indicate “parts by weight” and “% by weight”.

[Synthesis Example 1]
In a polyester reaction vessel equipped with a stirrer, thermometer, nitrogen gas introduction tube, rectification tube, moisture separator, etc., 50.0 parts of isophthalic acid, 18.9 parts of adipic acid, 0.77 parts of coconut oil fatty acid, Charge 37.8 parts of neopentyl glycol, 9.1 parts of diethylene glycol, 0.48 part of trimethylolpropane and 0.03 part of tetrabutyl titanate, and gradually heat so that the upper temperature of the rectification tube does not exceed 100 ° C. The internal temperature was kept at 240 ° C. When the acid value reached 5 mgKOH / g, the pressure was reduced to 20 mmHg or less, the acid value was confirmed to be 1 mgKOH / g or less, the esterification reaction was terminated, and 25 parts of ethyl acetate was added to dilute to obtain a non-volatile content of 75.1. A weight percent of polyester polyol was obtained. When the molecular weight distribution of this polyol was measured by GPC, the number average molecular weight in terms of styrene was 6000.

[Synthesis Example 2]
In the above polyester reaction vessel, terephthalic acid 25.0 parts, isophthalic acid 25.0 parts, adipic acid 18.9 parts, palm oil fatty acid 0.77 parts, neopentyl glycol 37.8 parts, diethylene glycol 9.1 parts Then, 0.48 part of trimethylolpropane and 0.03 part of tetrabutyl titanate were charged, and a polyester polyol was obtained in the same manner as in Synthesis Example 1. When the molecular weight distribution of this polyol was measured by GPC, the number average molecular weight in terms of styrene was 6000.

[Synthesis Example 3]
In the above polyester reaction vessel, 50.0 parts isophthalic acid, 18.9 parts adipic acid, 1.38 parts coconut oil fatty acid, 37.5 parts neopentyl glycol, 9.1 parts diethylene glycol, 0.86 trimethylolpropane Part and tetrabutyl titanate 0.03 part were charged, and a polyester polyol was obtained in the same manner as in Synthesis Example 1. When the molecular weight distribution of this polyol was measured by GPC, the number average molecular weight in terms of styrene was 6000.

[Synthesis Example 4]
In the above polyester reaction vessel, 49.5 parts of isophthalic acid, 18.7 parts of adipic acid, 0.77 parts of palm oil fatty acid, 39.0 parts of neopentyl glycol, 9.1 parts of diethylene glycol, 0.48 of trimethylolpropane Part and tetrabutyl titanate 0.03 part were charged, and a polyester polyol was obtained in the same manner as in Synthesis Example 1. When the molecular weight distribution of this polyol was measured by GPC, the number average molecular weight in terms of styrene was 4000.

[Synthesis Example 5]
In the above polyester reaction vessel, 50.5 parts of isophthalic acid, 19.6 parts of adipic acid, 0.75 parts of palm oil fatty acid, 37.5 parts of neopentyl glycol, 9.1 parts of diethylene glycol, 0.47 of trimethylolpropane Part and tetrabutyl titanate 0.03 part were charged, and a polyester polyol was obtained in the same manner as in Synthesis Example 1. When the molecular weight distribution of this polyol was measured by GPC, the number average molecular weight in terms of styrene was 14,000.

[Synthesis Example 6]
In the above polyester reaction vessel, 50.0 parts of isophthalic acid, 18.9 parts of adipic acid, 1.54 parts of palm oil fatty acid, 38.5 parts of neopentyl glycol, 9.1 parts of diethylene glycol and 0.03 of tetrabutyl titanate The polyester polyol was obtained in the same manner as in Synthesis Example 1. When the molecular weight distribution of this polyol was measured by GPC, the number average molecular weight in terms of styrene was 6000.

[Synthesis Example 7]
In the above polyester reaction vessel, 50.0 parts of isophthalic acid, 18.9 parts of adipic acid, 37.2 parts of neopentyl glycol, 9.1 parts of diethylene glycol, 0.86 part of trimethylolpropane and 0.03 part of tetrabutyl titanate And a polyester polyol was obtained in the same manner as in Synthesis Example 1. When the molecular weight distribution of this polyol was measured by GPC, the number average molecular weight in terms of styrene was 6000.

[Synthesis Example 8]
In the above polyester reaction vessel, 50.1 parts of isophthalic acid, 18.9 parts of adipic acid, 2.99 parts of coconut oil fatty acid, 37.0 parts of neopentyl glycol, 9.1 parts of diethylene glycol, 1.86 of trimethylolpropane Part and tetrabutyl titanate 0.03 part were charged, and a polyester polyol was obtained in the same manner as in Synthesis Example 1. When the molecular weight distribution of this polyol was measured by GPC, the number average molecular weight in terms of styrene was 6000.

[Synthesis Example 9]
In the above polyester reaction vessel, 50.0 parts isophthalic acid, 18.1 parts adipic acid, 0.77 parts palm oil fatty acid, 47.7 parts diethylene glycol, 0.48 parts trimethylolpropane and 0.03 parts tetrabutyl titanate. And a polyester polyol was obtained in the same manner as in Synthesis Example 1. When the molecular weight distribution of this polyol was measured by GPC, the number average molecular weight in terms of styrene was 6000.

  The polyester polyol and polyisocyanate prepared above were blended as shown in Table 2 and Table 3 below. Viscosity at Zahn Cup # 3 with non-volatile content of 40% by weight, initial adhesive strength immediately after composite film in which nylon film and LLDPE (linear low density polyethylene) are bonded, normal adhesive strength after aging, and boil resistance The measurement was also shown.

The manufacturing method of a composite film is shown below. As shown in Tables 2 and 3, a two-part curable adhesive containing ethyl acetate, which is a main agent, a curing agent, and a diluent solvent, was applied using a bar coater to a coating amount of 3.5 g (nonvolatile content) / m. A 15 μm adhesive surface coated with a biaxially stretched nylon film so as to be ² and volatilized with a drier set at a temperature of 70 ° C. and dried to dry the adhesive composition, and an LLDPE (60 μm) film. Were laminated to prepare a composite film composed of two layers of nylon / LLDPE. Next, this composite film was aged at 40 ° C. for 3 days to cure the adhesive to obtain a two-layer composite film.

[Initial bond strength]
The composite film was measured by T-type peeling using a tensile tester at a peeling speed of 300 mm / min and room temperature (25 ° C.), and the tensile strength was defined as adhesive strength. The adhesive strength (kgf / 15 mm) is preferably 0.05 kgf / 15 mm or more.

[Normal adhesive strength]
The aged composite film was measured by T-type peeling using a tensile tester at a peeling speed of 300 mm / min and room temperature (25 ° C.), and the tensile strength was defined as adhesive strength. The unit of adhesive strength is kgf / 15 mm. The normal state adhesive strength (kgf / 15 mm) is preferably 1.0 kgf / 15 mm or more.

[Boil resistance]
A 120 mm square pouch was prepared from the aged composite film, and the contents were filled with 70 g of pseudo food prepared by mixing vinegar, salad oil, and meat sauce at a weight ratio of 1: 1: 1. The produced pouch was sterilized by boiling at 98 ° C. for 60 minutes, and the appearance of the pouch was visually observed. The case where floating occurred after boil sterilization was evaluated as “x”, and the case where there was no floating was evaluated as “◯”.

ＮＰＧ：ネオペンチルグリコール ＤＥＧ：ジエチレングリコール
ＴＭＰ：トリメチロールプロパン ＡＡ：アジピン酸
ＩＰＡ：イソフタル酸 ＴＰＡ：テレフタル酸 ＣＯＡ：やし油脂肪酸
｛ ｝ポリオール成分中の重量％
［ ］酸成分中の重量％

NPG: neopentyl glycol DEG: diethylene glycol TMP: trimethylolpropane AA: adipic acid IPA: isophthalic acid TPA: terephthalic acid COA: palm oil fatty acid {} wt% in polyol component
[]% By weight in acid component

As is apparent from the results in Tables 2 and 3, it can be seen that the two-part curable adhesive of the present invention can be applied at a high non-volatile content and exhibits excellent adhesion performance and boil resistance.
In Comparative Example 1 (number average molecular weight 4000) in which the number average molecular weight of the polyester polyol is outside the range of 5,000 to 10,000, the initial adhesive strength and the normal adhesive strength are low, and the boil resistance is also poor. In Comparative Example 2 (number average molecular weight 14000), the compounding viscosity is high and the coating property is poor. Comparative Example 3 does not use a polyhydric alcohol having 3 or more hydroxyl groups, has low initial adhesive strength and normal adhesive strength, and poor boil resistance. In Comparative Example 5 using 3.9% by weight of polyhydric alcohol having 3 or more hydroxyl groups, which is outside the range of 0.5 to 3% by weight, the compounding viscosity is high and the coating property is inferior.
In the present invention, 0.5 to 3% by weight of a monofunctional fatty acid containing a linear or branched hydrocarbon group having 8 or more carbon atoms is used as the acid component. Low bond strength and normal bond strength. Further, Comparative Example 6 using 0.5 to 3% by weight of a polyhydric alcohol having 3 or more hydroxyl groups and not using a glycol having 30% by weight or more of side chain alkyl groups in the remaining polyol component has a compounding viscosity. High and inferior in coatability.
In the present invention, as the polyol component, (a) a polyhydric alcohol having 3 or more of 0.5 to 3% by weight of a hydroxyl group, and (b) 30% by weight or more of the remaining polyol component has a side chain alkyl group. Using glycol, the acid component is reacted with (c) a monofunctional fatty acid containing a straight or branched hydrocarbon group having 8 or more carbon atoms and (d) a dibasic acid, and the number average molecular weight is 5, By using polyester polyol of 000 to 10,000 as the main agent, a dry lamination adhesive having both high initial adhesive strength immediately after lamination and normal adhesive strength and excellent boil resistance can be obtained.

Claims (4)

A two-component curable adhesive comprising a polyester polyol and a polyisocyanate that is a curing agent,
The polyester polyol has a number average molecular weight of 5,000 to 10,000;
The polyester polyol is obtained by reacting a polyol component with a mixture of a monofunctional fatty acid containing a hydrocarbon group having a straight chain or branched chain having 8 or more carbon atoms and a dibasic acid,
Wherein 0.5 to 3 wt% of the polyol component is a polyhydric alcohol having 3 or more hydroxyl groups, Ru Oh glycolic more than 30 wt% in the remaining polyol component having a side-chain alkyl group, two-component curing Mold adhesive. Two-component curable adhesive according to 請 Motomeko 1 that the polyester polyol having a mean 1.9 to 2.1 hydroxyl groups per molecule. The two-component curable adhesive according to claim 1 or 2, wherein the monofunctional fatty acid is a fatty acid derived from natural fats and oils. The two-component curable adhesive according to any one of claims 1 to 3, having a nonvolatile content of 40% by weight or more and a Zahn cup viscosity at 25 ° C of 15 to 25 seconds.