阅读说明：本技术 水易分解性粘接剂组合物 (Water-decomposable adhesive composition ) 是由 一色绘利香 石崎谦一 堀江洋慈 冈崎荣一 于 2019-02-08 设计创作，主要内容包括：一种水易分解性粘接剂组合物为粘接剂组合物,上述粘接剂组合物含有2-氰基丙烯酸酯化合物和水溶性化合物,将上述粘接剂组合物的固化物在40℃的水中浸渍24小时时的吸水率为5％以上。将上述粘接剂组合物的固化物在23℃的水中浸渍24小时时的吸水率优选为5％以上。(An easily water-decomposable adhesive composition which contains a 2-cyanoacrylate compound and a water-soluble compound, and in which the water absorption rate of a cured product of the adhesive composition when the cured product is immersed in water at 40 ℃ for 24 hours is 5% or more. The water absorption rate of the cured product of the adhesive composition is preferably 5% or more when the cured product is immersed in water at 23 ℃ for 24 hours.)

1. A water-decomposable adhesive composition which is an adhesive composition,

the adhesive composition contains a 2-cyanoacrylate compound and a water-soluble compound,

the water absorption rate of a cured product of the adhesive composition is 5% or more when the cured product is immersed in water at 40 ℃ for 24 hours.

2. The easily water-decomposable adhesive composition according to claim 1, wherein a water absorption rate of a cured product of the adhesive composition when immersed in water at 23 ℃ for 24 hours is 5% or more.

3. The easily water-decomposable adhesive composition according to claim 1 or claim 2, wherein a cured product of the adhesive composition has a dissolution rate of 5% or more when immersed in water at 40 ℃ for 24 hours.

4. The easily water-decomposable adhesive composition according to any one of claims 1 to 3, wherein a dissolution rate of a cured product of the adhesive composition when immersed in water at 23 ℃ for 24 hours is 2% or more.

5. The water-decomposable adhesive composition according to any one of claims 1 to 4, wherein the water-soluble compound has a solubility parameter of 8.0 (cal/cm)³)^0.5Above and 23.4 (cal/cm)³)⁰ _. ⁵The following.

6. The water-decomposable adhesive composition according to any one of claims 1 to 5, wherein the 2-cyanoacrylate compound has a solubility parameter of 10.0 (cal/cm)³)^0.5Above and 23.4 (cal/cm)³)^0.5The following.

7. The easily water-decomposable adhesive composition according to any one of claims 1 to 6, wherein a cured product of the adhesive composition has a total light transmittance of 80% or more as measured according to JIS K7361-1, and a total light transmittance of 50% or less as measured according to JIS K7361-1 after the cured product is immersed in water at 40 ℃ for 24 hours.

8. The easily water-decomposable adhesive composition according to any one of claims 1 to 7, wherein the total light transmittance measured according to JIS K7361-1 after immersing the cured product in water at 23 ℃ for 24 hours is 70% or less.

9. The easily water-decomposable adhesive composition according to any one of claims 1 to 8, wherein a cured product of the adhesive composition has a haze value measured according to JIS K7136 of 1% or more and 70% or less, and the cured product has a haze value measured according to JIS K7136 of 95% or more after being immersed in water at 40 ℃ for 24 hours.

10. The easily water-decomposable adhesive composition according to any one of claims 1 to 9, wherein the cured product has a haze value of 95% or more as measured according to JIS K7136 after being immersed in water at 23 ℃ for 24 hours.

11. The easily water-decomposable adhesive composition according to any one of claims 1 to 10, wherein the content of the water-soluble compound is 0.5 parts by mass or more and 50 parts by mass or less based on 100 parts by mass of the total content of the 2-cyanoacrylate compound and the water-soluble compound.

12. The water-decomposable adhesive composition according to any one of claims 1 to 11, wherein the 2-cyanoacrylate compound is a 2-cyanoacrylate alkyl ester compound or a 2-cyanoacrylate compound having an ether bond, a carbonate bond or a sulfonyl bond.

13. The water-decomposable adhesive composition according to any one of claims 1 to 12, wherein the 2-cyanoacrylate compound is at least 1 compound selected from the group consisting of ethyl 2-cyanoacrylate, ethoxyethyl 2-cyanoacrylate, methoxyethyl 2-cyanoacrylate, methoxypropoxypropyl 2-cyanoacrylate, tetrahydrofurfuryl 2-cyanoacrylate, glycerol carbonate-2-cyanoacrylate, sulfolane methyl 2-cyanoacrylate, and methoxyethoxyethyl 2-cyanoacrylate.

14. The water-easily decomposable adhesive composition according to any one of claims 1 to 13, wherein the water-soluble compound is at least 1 compound selected from the group consisting of ethylene carbonate, dimethyl sulfone, sulfolane, γ -butylene carbonate, propylene carbonate, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, polyoxyalkylene alkyl ether, polyoxyalkylene dialkyl ether, polyoxyalkylene acetate, polyoxyalkylene diacetate, and polyoxyethylene glycerol borate fatty acid ester.

15. The water-decomposable adhesive composition according to any one of claims 1 to 14, which is a water-decomposable adhesive composition for temporary fixation.

16. The water-decomposable adhesive composition according to any one of claims 1 to 15, which is a water-decomposable adhesive composition for teaching materials.

Technical Field

The present invention relates to a water-decomposable adhesive composition.

Background

The adhesive composition containing a 2-cyanoacrylate compound can utilize the specific anionic polymerizability of the 2-cyanoacrylate compound as a main component and can initiate polymerization by a small amount of weak anions such as moisture attached to the surface of an adherend, thereby firmly bonding various materials in a short time. Therefore, the instant adhesive is used in a wide range of fields such as industrial use, medical use, and household use.

Since a cured product of an adhesive composition containing a 2-cyanoacrylate compound is hard and has excellent shear adhesive strength, and on the other hand, the adhesive composition has too strong adhesiveness, it takes time to peel or remove the cured product after curing the adhesive composition, or an adherend may be damaged.

As a technique for peeling off an adhesive composition containing a 2-cyanoacrylate compound, for example, patent document 1 describes: a cyanoacrylate adhesive composition which is obtained by blending a water-soluble polyoxyalkylene glycol solvent and a water-soluble surfactant into cyanoacrylate and has improved water solubility after curing is immersed in hot water or pressurized hot water for peeling.

Patent document 2 describes a method of fixing a quartz glass workpiece to a surface plate with a fixing agent and peeling the workpiece from the surface plate by heating after machining, wherein the fixing agent is an ultraviolet curable resin, and the workpiece is impregnated with a halogen-containing organic solvent before being peeled from the surface plate, and further describes: as the fixing agent, a cyanoacrylate adhesive is used.

Patent document 1: japanese patent laid-open No. 2000-73015

Patent document 2: japanese patent laid-open publication No. 2011-104747

Disclosure of Invention

Problems to be solved by the invention

However, in the technique described in patent document 1, in order to peel off the adhesive composition, it is necessary to dip the cured product in hot water or hot water under pressure (100 ℃ C. to 130 ℃ C.) for 20 minutes to 80 minutes; in the technique described in patent document 2, the cured product is heated in water until the water boils, and the temperature is maintained for about 5 minutes to about 20 minutes after the water boils.

Therefore, for example, in the case of adhering human fingers to each other, the methods described in these documents cannot be adopted because of the risk of scalding, and in the case of temporary adhesion for industrial use, there is a problem of increasing the cost in order to secure and maintain the amount of heat required for peeling.

Accordingly, an object of the present invention is to provide a water-decomposable adhesive composition which can be easily peeled or removed with water after curing, as compared with the case where only the corresponding cyanoacrylate compound is contained.

Means for solving the problems

The means for solving the above problems include the following means.

< 1 > a water-decomposable adhesive composition which is an adhesive composition,

the adhesive composition contains a 2-cyanoacrylate compound and a water-soluble compound,

the water absorption rate of the cured product of the adhesive composition is 5% or more when the cured product is immersed in water at 40 ℃ for 24 hours.

< 2 > the easily water-decomposable adhesive composition according to < 1 >, wherein a cured product of the adhesive composition has a water absorption of 5% or more when immersed in water at 23 ℃ for 24 hours.

< 3 > the easily water-decomposable adhesive composition according to < 1 > or < 2 >, wherein a dissolution rate of a cured product of the adhesive composition when immersed in water at 40 ℃ for 24 hours is 5% or more.

< 4 > the water-decomposable adhesive composition according to any one of < 1 > to < 3 >, wherein a cured product of the adhesive composition has a dissolution rate of 2% or more when immersed in water at 23 ℃ for 24 hours.

< 5 > the water-decomposable adhesive composition according to any one of < 1 > to < 4 >, wherein the water-soluble compound has a solubility parameter of 8.0 (cal/cm)³)^0.5Above and 23.4 (cal/cm)³)^0.5The following.

< 6 > the water-decomposable adhesive composition according to any one of < 1 > to < 5 >, wherein the 2-cyanoacrylate compound has a solubility parameter of 10.0 (cal/cm)³)^0.5Above and 23.4 (cal/cm)³)^0.5The following.

< 7 > the easily water-decomposable adhesive composition according to any one of < 1 > to < 6 >, wherein a total light transmittance measured according to JIS K7361-1 of a cured product of the adhesive composition is 80% or more, and a total light transmittance measured according to JIS K7361-1 of the cured product after immersion in water at 40 ℃ for 24 hours is 50% or less.

< 8 > the easily water-decomposable adhesive composition according to any one of < 1 > to < 7 >, wherein the total light transmittance measured according to JIS K7361-1 after immersing the cured product in water at 23 ℃ for 24 hours is 70% or less.

< 9 > the easily water-decomposable adhesive composition according to any one of < 1 > to < 8 >, wherein a cured product of the adhesive composition has a haze value of 1% or more and 70% or less as measured according to JIS K7136, and the haze value of 95% or more as measured according to JIS K7136 after the cured product is immersed in water at 40 ℃ for 24 hours.

< 10 > the easily water-decomposable adhesive composition according to any one of < 1 > to < 9 >, wherein the cured product has a haze value of 95% or more as measured according to JIS K7136 after being immersed in water at 23 ℃ for 24 hours.

< 11 > the water-decomposable adhesive composition according to any one of < 1 > to < 10 >, wherein the content of the water-soluble compound is 0.5 to 50 parts by mass based on 100 parts by mass of the total content of the 2-cyanoacrylate compound and the water-soluble compound.

< 12 > the water-decomposable adhesive composition according to any one of < 1 > to < 11 >, wherein the 2-cyanoacrylate compound is an alkyl 2-cyanoacrylate compound or a 2-cyanoacrylate compound having an ether bond, a carbonate bond or a sulfonyl bond.

< 13 > the water-decomposable adhesive composition according to any one of < 1 > to < 12 >, wherein the 2-cyanoacrylate compound is at least 1 compound selected from the group consisting of ethyl 2-cyanoacrylate, ethoxyethyl 2-cyanoacrylate, methoxyethyl 2-cyanoacrylate, methoxypropoxypropyl 2-cyanoacrylate, tetrahydrofurfuryl 2-cyanoacrylate, glycerol carbonate-2-cyanoacrylate, sulfolane methyl 2-cyanoacrylate, and methoxyethoxyethyl 2-cyanoacrylate.

< 14 > the water-decomposable adhesive composition according to any one of < 1 > to < 13 >, wherein the water-soluble compound is at least 1 compound selected from the group consisting of ethylene carbonate, dimethyl sulfone, sulfolane, γ -butylene carbonate, propylene carbonate, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, polyoxyethylene decyl ether, and polyoxyethylene glycerol borate fatty acid ester.

< 15 > the water-decomposable adhesive composition according to any one of < 1 > to < 14 >, which is a water-decomposable adhesive composition for temporary fixation.

< 16 > the water-decomposable adhesive composition according to any one of < 1 > to < 15 >, which is a water-decomposable adhesive composition for teaching materials.

< 2-1 > A water-decomposable adhesive composition comprising a 2-cyanoacrylate compound and a water-soluble compound having a solubility parameter of 8.0 (cal/cm)³)^0.5Above and 23.4 (cal/cm)³)^0.5The following.

< 2-2 > the water-decomposable adhesive composition < 2-1 > wherein the 2-cyanoacrylate compound has a solubility parameter of 10.0 (cal/cm)³)^0.5Above and 23.4 (cal/cm)³)^0.5The following.

< 2-3 > the water-decomposable adhesive composition according to < 2-1 > or < 2-2 >, wherein the water-soluble compound is contained in an amount of 0.5 to 50 parts by mass based on 100 parts by mass of the total content of the 2-cyanoacrylate compound and the water-soluble compound.

< 2-4 > the water-decomposable adhesive composition according to any one of < 2-1 > < 2-3 >, wherein the 2-cyanoacrylate compound is an alkyl 2-cyanoacrylate compound or a 2-cyanoacrylate compound having an ether bond, a carbonate bond or a sulfonyl bond.

< 2-5 > the water-decomposable adhesive composition according to any one of < 2-1 > < 2-4 >, wherein the 2-cyanoacrylate compound is at least 1 compound selected from the group consisting of ethyl 2-cyanoacrylate, methoxyethyl 2-cyanoacrylate, ethoxyethyl 2-cyanoacrylate, methoxypropoxypropyl 2-cyanoacrylate, tetrahydrofurfuryl 2-cyanoacrylate, glycerol-1, 2-carbonate-3- (2-cyanoacrylate), sulfolane methyl 2-cyanoacrylate, and methoxyethoxyethyl 2-cyanoacrylate.

< 2-6 > the water-easily decomposable adhesive composition according to any one of < 2-1 > -2-5, wherein the water-soluble compound is at least 1 compound selected from the group consisting of ethylene carbonate, dimethyl sulfone, sulfolane, γ -butylene carbonate, propylene carbonate, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, polyoxyalkylene alkyl ether, polyoxyalkylene dialkyl ether, polyoxyalkylene acetate, polyoxyalkylene diacetate, and polyoxyethylene glycerol borate fatty acid ester.

< 2-7 > the water-decomposable adhesive composition according to any one of < 2-1 > -2-6, which is a water-decomposable adhesive composition for temporary fixation.

< 2-8 > the water-decomposable adhesive composition according to any one of < 2-1 > -2-7, which is a water-decomposable adhesive composition for teaching materials.

< 3-1 > a water-decomposable adhesive composition which is an adhesive composition,

the adhesive composition contains a 2-cyanoacrylate compound and a water-soluble compound,

the total light transmittance of the cured product of the adhesive composition measured according to JIS K7361-1 is 80% or more,

the cured product is immersed in water at 40 ℃ for 24 hours, and then the total light transmittance measured according to JIS K7361-1 is 50% or less.

< 3-2 > the water-decomposable adhesive composition < 3-1 > wherein the total light transmittance measured according to JIS K7361-1 after immersing the cured product in water at 23 ℃ for 24 hours is 70% or less.

< 3-3 > the water-decomposable adhesive composition according to < 3-1 > or < 3-2 >, wherein a cured product of the adhesive composition has a haze value of 1% or more and 70% or less as measured according to JIS K7136, and the cured product has a haze value of 95% or more as measured according to JIS K7136 after being immersed in water at 40 ℃ for 24 hours.

< 3-4 > the water-decomposable adhesive composition according to any one of < 3-1 > -3 >, wherein the cured product has a haze value of 95% or more as measured according to JIS K7136 after being immersed in water at 23 ℃ for 24 hours.

< 3-5 > the water-decomposable adhesive composition according to any one of < 3-1 > -3-4, wherein the water-soluble compound is contained in an amount of 0.5 to 50 parts by mass based on 100 parts by mass of the total content of the 2-cyanoacrylate compound and the water-soluble compound.

< 3-6 > the water-decomposable adhesive composition according to any one of < 3-1 > < 3-5 >, wherein the 2-cyanoacrylate compound is an alkyl 2-cyanoacrylate compound or a 2-cyanoacrylate compound having an ether bond, a carbonate bond or a sulfonyl bond.

< 3-7 > the water-decomposable adhesive composition according to any one of < 3-1 > - < 3-6 >, wherein the 2-cyanoacrylate compound is at least 1 compound selected from the group consisting of ethyl 2-cyanoacrylate, ethoxyethyl 2-cyanoacrylate, methoxyethyl 2-cyanoacrylate, methoxypropoxypropyl 2-cyanoacrylate, tetrahydrofurfuryl 2-cyanoacrylate, glycerol carbonate-2-cyanoacrylate, sulfolane methyl 2-cyanoacrylate, and methoxyethoxyethyl 2-cyanoacrylate.

< 3-8 > the water-easily decomposable adhesive composition according to any one of < 3-1 > -to < 3-7 >, wherein the water-soluble compound is at least 1 compound selected from the group consisting of ethylene carbonate, dimethyl sulfone, sulfolane, γ -butylene carbonate, propylene carbonate, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, polyoxyalkylene alkyl ether, polyoxyalkylene dialkyl ether, polyoxyalkylene acetate, polyoxyalkylene diacetate, and polyoxyethylene glycerol borate fatty acid ester.

< 3-9 > the water-decomposable adhesive composition according to any one of < 3-1 > -3-8, which is a water-decomposable adhesive composition for temporary fixation.

< 3-10 > the water-decomposable adhesive composition according to any one of < 3-1 > -3-9, which is a water-decomposable adhesive composition for teaching materials.

Effects of the invention

According to the present invention, there can be provided a water-decomposable adhesive composition which can be easily peeled or removed with water after curing, as compared with the case where only the corresponding cyanoacrylate compound is contained.

Detailed Description

The following description of the constituent elements may be based on a representative embodiment of the present invention, but the present invention is not limited to such an embodiment. In the present specification, "to" is used in the sense of including the numerical values before and after the "to" as the lower limit value and the upper limit value.

In the numerical ranges recited in the present specification in stages, the upper limit or the lower limit recited in one numerical range may be replaced with the upper limit or the lower limit recited in another numerical range recited in stages. In the numerical ranges described in the present specification, the upper limit or the lower limit of the numerical range may be replaced with the values shown in the examples.

In the present invention, "mass%" and "weight%" have the same meaning, and "parts by mass" and "parts by weight" have the same meaning.

In the present invention, a combination of 2 or more preferred embodiments is a more preferred embodiment.

The present invention will be described in detail below.

(Water-decomposable adhesive composition)

A first embodiment of the easily water-decomposable adhesive composition of the present invention (hereinafter also simply referred to as "adhesive composition") is an adhesive composition containing a 2-cyanoacrylate compound and a water-soluble compound, and a cured product of the adhesive composition has a water absorption rate of 5% or more when immersed in water at 40 ℃ for 24 hours.

As a result of intensive studies, the present inventors have found that an adhesive composition which is easily decomposable by water and can be peeled or removed by water after curing can be provided by adopting the above-mentioned constitution.

The mechanism of action of the excellent effect by this is not clear, but is estimated as follows.

And (3) deducing: when a cured product of the adhesive composition contains a water-soluble compound and is immersed in water at 40 ℃ for 24 hours, the water absorption rate is 5% or more, whereby embrittlement and decomposition due to deformation caused by water absorption and swelling of the cured product or elution of the water-soluble compound easily occur, and further, water penetration into the adhesive interface and a decrease in adhesive strength easily occur, and therefore, the peeling or removal properties by water after curing (also referred to as "water-disintegrability" in the present invention) are excellent.

The first embodiment of the adhesive composition of the present invention is excellent in water-decomposability and can be easily peeled or removed in a short time by hot water or hot water under pressure, and it is needless to say that the adhesive composition of the present invention can be peeled or removed by immersion in water at a temperature ranging from normal temperature (15 ℃ C. to 25 ℃ C.) to warm water (30 ℃ C. to 45 ℃ C.), for example.

A second embodiment of the easily water-decomposable adhesive composition of the present invention comprises a 2-cyanoacrylate compound and a water-soluble compound having a solubility parameter of 8.0 (cal/cm)³)^0.5Above and 23.4 (cal/cm)³)^0.5The following.

The present inventors have conducted intensive studies and as a result, have found that the above-mentioned constitution can provide a water-decomposable adhesive composition which can be peeled off or removed by water after curing.

The mechanism of action of the excellent effect by this is not clear, but is estimated as follows.

And (3) deducing: by containing a compound which is soluble in a 2-cyanoacrylate compound and has a solubility parameter of 8.0 (cal/cm)³)^0.5Above and 23.4 (cal/cm)³)^0.5The following water-soluble compound is excellent in compatibility between the 2-cyanoacrylate compound and the water-soluble compound in the adhesive composition, and therefore, the water-soluble compound is sufficiently dispersed in the polymer of the 2-cyanoacrylate compound even after curing, and when the polymer comes into contact with water, the water-soluble compound is dissolved in water as a starting point, so that the water-soluble compound is excellent in permeability into a cured product, and the water-soluble compound is decomposed by embrittlement of the cured product caused by water absorption and swelling of the cured product or dissolution deformation of the water-soluble compound and a slight external force, and the water-soluble compound is reduced in permeability into an adhesive interface and adhesive force, so that the water-soluble compound is excellent in releasability or removability (also referred to as "water-easily-decomposable" in the present invention) by water after curing.

The second embodiment of the adhesive composition of the present invention is excellent in water-decomposability and can be easily peeled or removed in a short time by hot water or hot water under pressure, and it is needless to say that the adhesive composition of the present invention can be peeled or removed by immersion in water at a temperature ranging from normal temperature (15 ℃ C. to 25 ℃ C.) to warm water (30 ℃ C. to 45 ℃ C.), for example.

A third embodiment of the water-decomposable adhesive composition of the present invention is an adhesive composition containing a 2-cyanoacrylate compound and a water-soluble compound, wherein a total light transmittance of a cured product of the adhesive composition measured according to JIS K7361-1 is 80% or more, and a total light transmittance of the cured product measured according to JIS K7361-1 after immersion in water at 40 ℃ for 24 hours is 50% or less.

The present inventors have conducted intensive studies and as a result, have found that the above-mentioned constitution can provide a water-decomposable adhesive composition which can be peeled off or removed by water after curing.

The mechanism of action of the excellent effect by this is not clear, but is estimated as follows.

And (3) deducing: when the total light transmittance of a cured product of the adhesive composition containing a water-soluble compound is 80% or more as measured according to JIS K7361-1 and the total light transmittance of the cured product as measured according to JIS K7361-1 after immersion in water at 40 ℃ for 24 hours is 50% or less, deformation and decomposition due to water absorption and swelling of the cured product are likely to occur, and the penetration of water into the adhesive interface and the decrease in adhesive force are likely to occur, the peeling or removal properties by water after curing (also referred to as "water-easily-decomposable" in the present invention) are excellent.

The third embodiment of the adhesive composition of the present invention is excellent in water-decomposability and can be easily peeled or removed in a short time by hot water or hot water under pressure, and it is needless to say that the third embodiment of the present invention can be peeled or removed by immersion in water at a temperature ranging from normal temperature (15 ℃ C. to 25 ℃ C.) to warm water (30 ℃ C. to 45 ℃ C.) or the like.

The details of each constituent element of the present invention will be described below. In the following description, the term "adhesive composition of the present invention" or "easily water-decomposable adhesive composition of the present invention" is used to refer to all of the first to third embodiments of easily water-decomposable adhesive compositions of the present invention.

< Water absorption (40 ℃ C.) >)

In the first embodiment of the adhesive composition of the present invention, the water absorption rate of the cured product of the adhesive composition when immersed in water at 40 ℃ for 24 hours is 5% or more, preferably 10% or more, and more preferably 20% or more, from the viewpoint of peelability with water.

In the second or third embodiment of the adhesive composition of the present invention, the water absorption rate when the cured product of the adhesive composition is immersed in water at 40 ℃ for 24 hours is preferably 5% or more, more preferably 10% or more, and even more preferably 20% or more, from the viewpoint of utilizing the releasability from water.

The upper limit of the water absorption rate is not particularly limited, but is preferably 1000% or less.

< Water absorption (23 ℃ C.) >)

In particular, from the viewpoint of peelability with water at room temperature (15 to 25 ℃), the water absorption rate of a cured product of the adhesive composition of the present invention when immersed in water at 23 ℃ for 24 hours is preferably 5% or more, more preferably 10% or more, and even more preferably 20% or more.

The upper limit of the water absorption rate is not particularly limited, but is preferably 1000% or less.

< dissolution rate (40 ℃ C.) >)

From the viewpoint of peelability with water, the dissolution rate when a cured product of the adhesive composition of the present invention is immersed in water at 40 ℃ for 24 hours is preferably 5% or more.

The upper limit of the dissolution rate is not particularly limited, and may be 100% or less.

< dissolution rate (23 ℃) >)

In particular, the dissolution rate of the cured product of the adhesive composition of the present invention when immersed in water at 23 ℃ for 24 hours is preferably 2% or more from the viewpoint of peelability with water at room temperature (15 ℃ to 25 ℃).

The upper limit of the dissolution rate is not particularly limited, and may be 100% or less.

< method for measuring Water absorption and dissolution Rate >

The water absorption and the dissolution rate were measured by the following methods.

About 4g of the adhesive composition was poured into a polyethylene container having a diameter of 50mm, 3. mu.L to 4. mu.L of N, N-dimethyl-p-toluidine was added thereto, and the mixture was stirred and then allowed to stand until completely cured to prepare a cured product having a diameter of 50 mm.

After curing, the cured product was taken out from the container, and the semicircular cured product obtained by dividing the container into two parts was used as a test piece for test and evaluation.

Then, one of the 2 semicircular test pieces was used as a soaking sample (a), and the other was used as a pre-test comparison sample (B, no soaking).

The test piece A was immersed in 80mL of distilled water at a temperature of 23 ℃. After standing for 24 hours, the test piece was taken out from the distilled water, and the surface water was wiped off, and the water absorption and dissolution rate at 23 ℃ were calculated according to the following formulas, respectively.

Similarly, test piece A prepared with the same formulation was immersed in 80mL of distilled water at a temperature of 40 ℃. After standing for 24 hours, the test piece was taken out from the distilled water, and the surface water was wiped off to evaluate as a test at 40 ℃.

For the test at 23 ℃ or the test at 40 ℃, the mass (a) of the test piece a before the soaking test, the mass (B) of the test piece a after the soaking test, and the mass (c) when the test piece a was recovered to 23 ℃ after dehydration by vacuum drying at 50 ℃ for 20 hours, the mass (d) of the test piece B before the test without soaking, and the mass (e) when the test piece B was recovered to 23 ℃ after dehydration by vacuum drying at 50 ℃ for 20 hours were measured, respectively.

Using the values of a to e described above, the water absorption and dissolution rate were calculated as follows.

Water absorption (%):

((b-c)-(a×(d-e)/d))/(a-a×(d-e/d))×100

dissolution rate (%):

((a-c)-(a×(d-e)/d))/(a-a×(d-e/d))×100

< Total light transmittance (after immersion at 40 ℃) >

In the third embodiment of the adhesive composition of the present invention, the total light transmittance measured according to JIS K7361-1 after immersing the cured product of the adhesive composition in water at 40 ℃ for 24 hours is 50% or less, preferably 40% or less, and more preferably 30% or less, from the viewpoint of peelability by water.

In the first or second embodiment of the adhesive composition of the present invention, the total light transmittance measured according to JIS K7361-1 after immersing the cured product of the adhesive composition in water at 40 ℃ for 24 hours is preferably 50% or less, more preferably 40% or less, and further preferably 30% or less, from the viewpoint of utilizing the peelability of water.

The lower limit is preferably 0% or more.

< Total light transmittance (after immersion at 23 ℃) >

In particular, from the viewpoint of peelability with water at room temperature (15 ℃ to 25 ℃), the total light transmittance measured according to JIS K7361-1 after immersing a cured product of the adhesive composition of the present invention in water at 23 ℃ for 24 hours is preferably 70% or less, more preferably 40% or less, and even more preferably 30% or less. The lower limit is preferably 0% or more.

< Total light transmittance (before immersion) >)

In particular, the total light transmittance of the cured product of the adhesive composition of the present invention measured at 23 ℃ or 40 ℃ according to JIS K7361-1 is preferably 80% or more, more preferably 85% or more, from the viewpoint of peelability with water at room temperature (15 ℃ to 25 ℃). The upper limit value may be 100% or less.

< haze value (after immersion at 40 ℃)

From the viewpoint of peelability with water, the haze value measured according to JIS K7136 after immersing a cured product of the adhesive composition of the present invention in water at 40 ℃ for 24 hours is preferably 95% or more, preferably 98% or more, and more preferably 99% or more.

The upper limit of the haze value is not particularly limited, and may be 100% or less.

< haze value (after 23 ℃ C. impregnation) >

In particular, from the viewpoint of peelability with water at room temperature (15 to 25 ℃), the haze value measured according to JIS K7136 after immersing a cured product of the adhesive composition of the present invention in water at 23 ℃ for 24 hours is preferably 90% or more, preferably 95% or more, and more preferably 98% or more.

The upper limit of the haze value is not particularly limited, and may be 100% or less.

< method for measuring Total light transmittance and haze >

The total light transmittance and the haze were measured by the following methods.

About 4g of the adhesive composition was poured into a polyethylene container having a diameter of 50mm, 3. mu.L to 4. mu.L of N, N-dimethyl-p-toluidine was added thereto, and the mixture was stirred and then allowed to stand until completely cured to prepare a cured product having a diameter of 50 mm.

After curing, the cured product was taken out from the container, and the semicircular cured product obtained by dividing the container into two parts was used as a test piece for test and evaluation.

Then, one of the 2 semicircular test pieces was tested as a test piece (a).

First, the total light transmittance of the test piece A was measured using a haze meter (NHD-2000, manufactured by Nippon Denshoku industries Co., Ltd.) according to JIS K7361-1.

Then, the haze of the test piece a was measured using a haze meter (NHD-2000, manufactured by japan electrochrome industry, ltd.) based on JIS K7136, and calculated by the following formula.

Haze (%) - (total light transmittance-parallel light transmittance)/total light transmittance

In any of the tests, the test piece was pressed so as to be perpendicular to the light source of the haze meter.

After the above measurement, the test piece A was immersed in 80mL of distilled water at a temperature of 23 ℃. After standing for 24 hours, the test piece was taken out from the distilled water and wiped to dry the water on the surface. Then, the total light transmittance (after dipping at 23 ℃) and the haze value (after dipping at 23 ℃) were measured by the same methods as those for measuring the total light transmittance and the haze value described above.

Similarly, test piece A prepared with the same formulation was immersed in 80mL of distilled water at a temperature of 40 ℃. After standing for 24 hours, the test piece was taken out from the distilled water and wiped to dry the water on the surface. Then, the total light transmittance (after dipping at 40 ℃) and the haze value (after dipping at 40 ℃) were measured by the same methods as those for measuring the total light transmittance and the haze value described above.

< 2-cyanoacrylate compound >

The adhesive composition of the present invention contains a 2-cyanoacrylate compound.

The 2-cyanoacrylate compound is not particularly limited and may be a 2-cyanoacrylate compound generally used in such adhesive compositions. Examples of the 2-cyanoacrylate compound include: methyl, ethyl, chloroethyl, n-propyl, isopropyl, allyl, propargyl, n-butyl, isobutyl, n-pentyl, n-hexyl, cyclohexyl, phenyl, tetrahydrofuryl, heptyl, 2-ethylhexyl, n-octyl, 2-octyl, n-nonyl, oxononyl, n-decyl, n-dodecyl, methoxyethyl, methoxypropyl, methoxyisopropyl, methoxybutyl, ethoxyethyl, ethoxypropyl, ethoxyisopropyl, propoxymethyl, propoxyethyl, isopropoxyethyl, propoxypropyl, butoxymethyl, butoxyethyl, butoxypropyl, butoxyisopropyl, butoxybutyl, methoxyethoxyethyl, 2,2, 2-trifluoroethyl, hexafluoroisopropyl, phenylethyl, phenoxyethyl, alkoxypolyethenoxyethyl esters, Esters such as alkoxypolypropyloxypropyl ester, glycerol carbonate, 2-sulfolane methyl ester, and 3-sulfolane methyl ester.

Further, as the 2-cyanoacrylate compound, from the viewpoint of easy degradability with water, an alkyl 2-cyanoacrylate compound or a 2-cyanoacrylate compound having an ether bond, a carbonate bond or a sulfonyl bond is preferable, a 2-cyanoacrylate compound having an ether bond, a carbonate bond or a sulfonyl bond is more preferable, and a 2-cyanoacrylate compound having an ether bond or a sulfonyl bond is particularly preferable.

Among them, from the viewpoint of easy water-decomposability, the 2-cyanoacrylate compound is preferably at least 1 compound selected from the group consisting of ethyl 2-cyanoacrylate, ethoxyethyl 2-cyanoacrylate, methoxyethyl 2-cyanoacrylate, methoxypropoxypropyl 2-cyanoacrylate, tetrahydrofurfuryl 2-cyanoacrylate, glycerol carbonate-2-cyanoacrylate, sulfolane methyl 2-cyanoacrylate, and methoxyethoxyethyl 2-cyanoacrylate.

[ solution 1]

From the viewpoint of easy water-decomposability and dispersibility of the water-soluble compound, the solubility parameter (SP value) of the 2-cyanoacrylate compound is preferably 8.0 (cal/cm)³)^0.5Above and 23.4 (cal/cm)³)^0.5More preferably 10.0 (cal/cm) or less³)^0.5Above and 23.4 (cal/cm)³)^0.5More preferably 10.0 (cal/cm) or less³)^0.5Above and 15.0 (cal/cm)³)^0.5Particularly preferably 10.0 (cal/cm) or less³)^0.5Above and 14.0 (cal/cm)³)^0.5The most preferable range is 10.0 (cal/cm) or less³)^0.512.0 (cal/cm) or more³)^0.5The following.

The solubility parameter (SP value) in the present invention is a value calculated by the calculation method described in "Polymer Engineering and Science" 14(2), 147(1974) by r.f. fedors. Specifically, the calculation method shown in equation (3) is used. Note that 2.0455 (cal/cm)³)^0.5＝1MPa^0.5。

[ number 1]

: SP value ((cal/cm)³)^1/2)

Δ Evap: heat of vaporization (cal/mol) of each atomic group

V: each sourceMolar volume (cm) of the sub-clusters³/mol)

When two or more kinds are used in combination, the calculation is performed by the following equation.

(SP value of mixture)²× (SP value of component 1) ((volume fraction of component 1))²+ (volume fraction of component 2) × (SP value of component 2)²+···

The 2-cyanoacrylate compound used in the adhesive composition of the present invention may be used alone or in combination of two or more.

From the viewpoint of easy water decomposability, adhesiveness, and curability, the content of the 2-cyanoacrylate compound in the adhesive composition of the present invention is preferably 40% by mass or more and 99.5% by mass or less, more preferably 50% by mass or more and 99.5% by mass or less, further preferably 60% by mass or more and 90% by mass or less, and particularly preferably 70% by mass or more and 85% by mass or less, relative to the total mass of the adhesive composition.

< Water-soluble Compound >

The adhesive composition of the present invention contains a water-soluble compound.

The water-soluble compound is preferably soluble in the above-mentioned 2-cyanoacrylate compound.

In the present invention, the fact that the water-soluble compound is soluble in the 2-cyanoacrylate compound means that: 1 part by mass of the water-soluble compound used was mixed at 25 ℃ with stirring to 100 parts by mass of the 2-cyanoacrylate compound used, and a uniform mixture was formed without visual phase separation.

In addition, in the present invention, the "water-soluble compound" means: and water in an arbitrary mixing ratio to form a solution or a compound having a solubility (25 ℃) of 1g/100g or more with respect to water.

In a second embodiment of the adhesive composition of the present invention, the water-soluble compound has a solubility parameter (SP value) of 8.0 (cal/cm)³)^0.5Above and 23.4 (cal/cm)³)^0.5Hereinafter, from the viewpoint of easy water-decomposability and compatibility with the 2-cyanoacrylate compound, preferred areIs 8.3 (cal/cm)³)^0.5Above and 15.0 (cal/cm)³)^0.5Hereinafter, more preferably 8.3 (cal/cm)³)^0.5Above and 14.0 (cal/cm)³)^0.5Hereinafter, particularly preferably 9.0 (cal/cm)³)^0.5Above and 14.0 (cal/cm)³)^0.5The following.

In the first or third embodiment of the adhesive composition of the present invention, the solubility parameter (SP value) of the water-soluble compound is preferably 8.0 (cal/cm) from the viewpoint of easy water-decomposability and compatibility with the 2-cyanoacrylate compound³)^0.5Above and 23.4 (cal/cm)³)^0.5Hereinafter, more preferably 8.3 (cal/cm)³)^0.5Above and 15.0 (cal/cm)³)^0.5Hereinafter, more preferably 8.3 (cal/cm)³)^0.5Above and 14.0 (cal/cm)³)^0.5Hereinafter, particularly preferably 9.0 (cal/cm)³)^0.5Above and 14.0 (cal/cm)³)^0.5The following.

In addition, the SP value of the water-soluble compound is preferably high from the viewpoint of utilizing the peeling and decomposition rate of water.

The water-soluble compound used in the present invention may be a low-molecular compound or a high-molecular compound. The low-molecular weight compound preferably has a molecular weight of less than 1,000, and the high-molecular weight compound preferably has a weight average molecular weight of 1,000 or more, more preferably 1,000 to 1,000,000.

The values of the number average molecular weight (Mn) and the weight average molecular weight (Mw) of the polymer compound in the present invention are measured by Gel Permeation Chromatography (GPC).

The water-soluble compound is not particularly limited, and from the viewpoint of easy water-degradability and compatibility with the 2-cyanoacrylate compound, a compound having at least 1 type of bond selected from the group consisting of an ester bond, a carbonate bond, and a sulfonyl bond is preferable, and a compound having at least 1 type of bond selected from the group consisting of a carbonate bond and a sulfonyl bond is more preferable.

Further, as the water-soluble polymer compound, polyacrylic acid, polyacrylate, cellulose acetate butyrate, and the like are preferably mentioned.

Further, as the water-soluble compound, a low-molecular compound and a high-molecular compound are preferably used in combination from the viewpoint of easy water-decomposability and viscosity.

Among them, from the viewpoint of easy water-decomposability and compatibility with the 2-cyanoacrylate compound, the water-soluble compound is preferably at least 1 compound selected from the group consisting of ethylene carbonate, dimethyl sulfone, sulfolane, γ -butylene carbonate, propylene carbonate, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol diethyl ether, ethylene glycol monomethyl ether acetate, polyoxyalkylene alkyl ether, polyoxyalkylene dialkyl ether, polyoxyalkylene acetate, polyoxyalkylene diacetate, and polyoxyethylene glycerol borate fatty acid ester, and more preferably selected from the group consisting of ethylene carbonate, dimethyl sulfone, sulfolane, propylene carbonate, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, polyoxyalkylene alkyl ether, polyoxyalkylene dialkyl ether, polyoxyalkylene acetate, tetraethylene glycol dimethyl ether, and polyoxyethylene glycerol borate fatty acid ester, At least 1 compound of the group consisting of a polyoxyalkylene diacetate and a polyoxyethylene glycerol borate fatty acid ester.

From the viewpoint of general versatility, the water-soluble compound is preferably at least 1 compound selected from the group consisting of ethylene carbonate, γ -butylene carbonate, dimethyl sulfone, propylene carbonate, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol diethyl ether, ethylene glycol monomethyl ether acetate, polyoxyalkylene alkyl ether, polyoxyalkylene dialkyl ether, polyoxyalkylene acetate, and polyoxyalkylene diacetate.

As the polyoxyalkylene alkyl ether, polyoxyalkylene dialkyl ether, polyoxyalkylene acetate, and polyoxyalkylene diacetate, for example, a compound having a structure represented by the following formula (1) is preferable.

R-(OCH₂CHX)_n·(OCH₂CH₂)_m-OR’

(in the formula (1), R, R' represents a hydrogen atom or a linear or branched alkyl or alkyl acetate group having 1 to 20 carbon atoms, X represents an alkyl group having 1 to 10 carbon atoms, n represents an integer of 0 to 20, and m represents an integer of 0 to 20.)

Preferred examples of the polyoxyethylene glycerol borate fatty acid ester include: examples of the compound include those prepared by Toho chemical industry, EMBLON (registered trademark) T-20 (polyoxyethylene glyceryl borate laurate), EMBLON T-40 (polyoxyethylene glyceryl borate palmitate), EMBLON T-60 (polyoxyethylene glyceryl borate stearate), EMBLON T-66 (polyoxyethylene glyceryl borate stearate), EMBLON T-80 (polyoxyethylene glyceryl borate oleate), EMBLON T-83 (polyoxyethylene glyceryl borate oleate), and EMBLON T-160 (polyoxyethylene glyceryl borate isostearate).

The water-soluble compound used in the adhesive composition of the present invention may be used alone or in combination of two or more.

From the viewpoint of easy water decomposability, the content of the water-soluble compound in the adhesive composition of the present invention is preferably 0.5% by mass or more and 50% by mass or less, more preferably 1% by mass or more and 40% by mass or less, further preferably 5% by mass or more and 35% by mass or less, and particularly preferably 10% by mass or more and 30% by mass or less, based on the total mass of the adhesive composition.

< other ingredients >

The adhesive composition of the present invention may contain other components than the above-mentioned 2-cyanoacrylate compound and the above-mentioned water-soluble compound.

As other components, a stabilizer, a curing accelerator, a plasticizer, a thickener, particles, a colorant, a fragrance, a solvent, a strength improver, and the like, which have been conventionally formulated in adhesive compositions containing 2-cyanoacrylate, may be blended in appropriate amounts within a range not impairing curability, adhesive strength, and the like of the adhesive composition according to the purpose.

As the stabilizer, there may be mentioned: (1) aliphatic sulfonic acids such as sulfur dioxide and methanesulfonic acid; aromatic sulfonic acids such as p-toluenesulfonic acid; boron trifluoride complexes such as boron trifluoride methanol and boron trifluoride diethyl ether; HBF₄(ii) a Anionic polymerization inhibitors such as trialkyl borate, and radical polymerization inhibitors such as (2) hydroquinone, hydroquinone monomethyl ether, t-butyl catechol, and pyrogallol. These stabilizers may be used alone or in combination of two or more.

Any curing accelerator may be used as long as it promotes anionic polymerization of the 2-cyanoacrylate-based adhesive composition. Examples of the curing accelerator include polyether compounds, calixarenes, thiacalixarenes, pyrogallol aromatics, onium salts and the like. These curing accelerators may be used alone or in combination of two or more.

Further, examples of the plasticizer include: acetyl triethyl citrate, acetyl tributyl citrate, dimethyl adipate, diethyl adipate, dimethyl sebacate, dimethyl phthalate, diethyl phthalate, dibutyl phthalate, diisodecyl phthalate, dihexyl phthalate, diheptyl phthalate, dioctyl phthalate, bis (2-ethylhexyl) phthalate, diisononyl phthalate, diisotridecyl phthalate, dipentadecyl phthalate, dioctyl terephthalate, diisononyl isophthalate, decyl toluate, bis (2-ethylhexyl) camphorate, 2-ethylhexyl cyclohexylcarboxylate, diisobutyl fumarate, diisobutyl maleate, trihexyl triglyceride, 2-ethylhexyl benzoate, dipropylene glycol dibenzoate, and the like. Among these, acetyl tributyl citrate, dimethyl adipate, dimethyl phthalate, 2-ethylhexyl benzoate, and dipropylene glycol dibenzoate are preferable in terms of good compatibility with the 2-cyanoacrylate compound and high plasticizing efficiency. These plasticizers may be used alone or in combination of two or more.

As the thickener, there may be mentioned: polymethyl methacrylate, a copolymer of methyl methacrylate and acrylic acid ester, a copolymer of methyl methacrylate and other methacrylic acid ester, acrylic rubber, polyvinyl acetate, polyvinyl chloride, polyurethane resin, polyamide resin, polystyrene, cellulose ester, poly-2-alkyl cyanoacrylate, ethylene-vinyl acetate copolymer, and the like. These thickeners may be used alone or in combination of two or more.

The particles that can be mixed in the adhesive composition are components for adjusting the thickness of the adhesive layer when the adhesive composition is used.

The average particle diameter of the particles is preferably 10 to 200. mu.m, more preferably 15 to 200. mu.m, and still more preferably 15 to 150. mu.m.

The material of the particles is not particularly limited as long as it is insoluble in the 2-cyanoacrylate compound used and does not cause modification such as polymerization. Examples thereof include: thermoplastic resins such as polyethylene, polypropylene, polymethylpentene, acrylic resins, polyvinyl chloride, polytetrafluoroethylene, polyethylene terephthalate, polybutylene terephthalate, polysulfone, and polyphenylene oxide; crosslinked resins such as unsaturated polyesters, divinylbenzene polymers, divinylbenzene-styrene copolymers, divinylbenzene- (meth) acrylate copolymers, and diallyl phthalate polymers; inorganic compounds such as spherical silica, glass beads, and glass fibers; an organosilicon compound; organic-inorganic composite particles comprising an organic polymer skeleton and a polysiloxane skeleton, and the like.

The content of the particles is not particularly limited, and is preferably 0.1 to 10 parts by mass, more preferably 1 to 5 parts by mass, and still more preferably 1 to 3 parts by mass, based on 100 parts by mass of the 2-cyanoacrylate compound. When the amount is in the range of 0.1 to 10 parts by mass, the influence on the curing rate and the adhesive strength can be reduced.

The average particle diameter of the particles in the present invention is a volume-based average value measured by a laser diffraction particle size distribution measuring apparatus.

The water-decomposable adhesive composition of the present invention can be used for various applications without particular limitation.

Among them, the water-easily decomposable adhesive composition of the present invention can be suitably used as, for example, a water-easily decomposable adhesive composition for temporary fixation or a water-easily decomposable adhesive composition for teaching materials, because the adhesive composition at the bonding site or the cured adhesive composition adhered to an unnecessary site can be easily peeled or removed with water. The water-easily decomposable adhesive composition of the present invention can be peeled or removed by, for example, immersing in water or the like at a temperature ranging from room temperature (15 ℃ C. to 25 ℃ C.) to a temperature of about warm water (30 ℃ C. to 45 ℃ C.), and therefore can be easily peeled or removed by water even if it is attached to or cured at an unnecessary position such as a finger, for example. Further, since water can be peeled or removed in a temperature range from normal temperature to warm water, the amount of heat required for peeling can be reduced and the cost can be reduced when the temporary fixing is used for industrial purposes.

Here, as temporary fixing for industrial use, for example, temporary fixing of various electronic materials such as a semiconductor wafer, optical materials, and the like with various jigs such as a polishing platen, and the like can be cited.

The material to be bonded by the water-decomposable adhesive composition of the present invention is not particularly limited, and may be an inorganic compound, an organic compound, an inorganic-organic composite, or the same material or different materials. The water-decomposable adhesive composition of the present invention can be used for bonding solid articles of any shape.

The water-decomposable adhesive composition of the present invention can also be suitably used for temporary fixing.

That is, the temporary fixation method of the present invention includes, in order:

a step of preparing the water-decomposable adhesive composition of the present invention by mixing a 2-cyanoacrylate compound and a water-soluble compound (hereinafter referred to as "adhesive composition preparation step");

a step of forming an adhesive layer containing the adhesive composition between a plurality of members (hereinafter referred to as "adhesive layer forming step");

a step of curing the adhesive layer formed between the plurality of members to obtain a cured product, and temporarily bonding the plurality of members to each other by the cured product (hereinafter referred to as "temporary bonding step"); and

and a step (hereinafter referred to as "separation step") of separating the plurality of members by decomposing the cured product by contacting the cured product with water.

The temporary fixing method of the present invention may further include a step of processing the temporarily bonded member into a desired shape (hereinafter referred to as "processing step") between the temporary bonding and the separation step.

The respective steps of the temporary fixing method of the present invention will be described below.

The adhesive composition preparation step is a step of mixing a 2-cyanoacrylate compound and a water-soluble compound to prepare the water-decomposable adhesive composition of the present invention.

The 2-cyanoacrylate compound and the water-soluble compound which can be used in the present step are as described above.

In this step, the 2-cyanoacrylate and the water-soluble compound are mixed and stirred to obtain a uniform liquid, whereby an adhesive composition can be produced. The method for mixing the 2-cyanoacrylate and the water-soluble compound is not particularly limited, and the mixture may be left at a temperature of room temperature to 60 ℃ or lower, or may be mixed by using a stirrer or the like.

The adhesive layer forming step is a step of forming an adhesive layer containing the adhesive composition on at least 1 member of the plurality of members or between the plurality of members.

The adhesive layer forming step may be, for example, the following steps: the adhesive composition is applied to the surface to be bonded of the fixed member or members, and the other members are superposed on the applied position and the process is repeated. In this embodiment, for coating, a dispenser, a coater, a roller, a brush, a doctor blade, a spray, a coating jig, or the like may be used depending on the shape of the adherend. Alternatively, a method of impregnating the adhesive composition into the gaps of the adherend by immersing the adherend previously laminated in the adhesive composition can be mentioned. As the adherend, any article may be used as long as it is not deteriorated by the adhesive composition and water at a temperature of from room temperature to about warm water, and metals, ceramics, plastics, and the like can be used.

The temporary bonding step is a step of curing the adhesive composition applied between the plurality of members to obtain a cured product, and temporarily bonding the plurality of members to each other with the cured product.

Since the adhesive composition can be instantly cured by a small amount of moisture, a cured product can be obtained without providing a special apparatus or special conditions. In order to accelerate the curing reaction, the material may be heated to a temperature range not affecting the adherend, for example, about 40 ℃ to 100 ℃ to cure the material.

The separation step is a step of bringing the cured product into contact with water to decompose the cured product, thereby separating the plurality of members from each other.

In the separation step, as a method of bringing the cured product into contact with water, there are mentioned a method of immersing the adherend in water, exposing the adherend to flowing water, and spraying water onto the adherend. The treatment time depends on the contact method of water and the heating temperature, but is preferably in the range of, for example, 10 seconds to 3 minutes. Further, it is also preferable that separation is promoted by applying a mechanical external force or irradiating ultrasonic waves to the adherend when the adherend is brought into contact with water at a temperature of from room temperature to about warm water.

The processing step is a step of processing the temporarily bonded member into a desired shape between the temporary bonding and fixing step and the separating step. In the processing step, processing such as cutting, grinding, polishing, etching, etc. may be performed to form a desired shape.