An easily water-disintegrable adhesive composition contains a 2-cyanoacrylate compound and a water-soluble compound, and wherein a cured product of the adhesive composition has a water absorption rate of 5% or higher when immersed in 40° C. water for 24 hours. The cured product of the adhesive composition preferably has a water absorption rate of 5% or higher when immersed in 23° C. water for 24 hours.

An easily water-disintegrable adhesive composition contains a 2-cyanoacrylate compound and a water-soluble compound, and wherein a cured product of the adhesive composition has a water absorption rate of 5% or higher when immersed in 40° C. water for 24 hours. The cured product of the adhesive composition preferably has a water absorption rate of 5% or higher when immersed in 23° C. water for 24 hours.

A resin composition contains a 2-methylene-1,3-dicarbonyl compound and an initiator. The 2-methylene-1,3-dicarbonyl compound has a molecular weight of 180 to 10,000, and the initiator contains a basic substance having a pK.sub.a of 8 or greater. The 2-methylene-1,3-dicarbonyl compound contains a structural unit represented by the following formula (I) ##STR00001##

A resin composition contains a 2-methylene-1,3-dicarbonyl compound and an initiator. The 2-methylene-1,3-dicarbonyl compound has a molecular weight of 180 to 10,000, and the initiator contains a basic substance having a pK.sub.a of 8 or greater. The 2-methylene-1,3-dicarbonyl compound contains a structural unit represented by the following formula (I) ##STR00001##

Two-part cyanoacrylate/free radically curable adhesive systems demonstrating improved toughness are provided.

Two-part cyanoacrylate/free radically curable adhesive systems demonstrating improved toughness are provided.

Two-part cyanoacrylate/free radically curable adhesive systems demonstrating improved toughness are provided.

This composition contains (A) 100 parts of an organopolysiloxane having two groups represented by general formula (1) ##STR00001## (R.sup.1 represents a monovalent hydrocarbon group having 1-20 carbon atoms, R.sup.2 represents an oxygen atom or the like, R.sup.3 represents an acryloyloxyalkyl group or the like, p represents a number satisfying 0≤p≤10, and “a” represents a number satisfying 1≤a≤3) per molecule, (B) 1-500 parts of a monofunctional (meth)acrylate compound not containing a siloxane structure, (C) 1-5,000 parts of an organopolysiloxane resin containing (a) an R.sup.4.sub.3SiO.sub.1/2 unit (in the formula, R.sup.4 represents a monovalent hydrocarbon group having 1-10 carbon atoms) and (b) a SiO.sub.4/2 unit, where the molar ratio of the unit (a) to the unit (b) is in the range of 0.6 to 1.2:1, (D) 1-100 parts of fine powder silica, and (E) 0.01-20 parts of an optical polymerization initiator. The compound has good shape retention properties and curability for irradiation with ultraviolet light, and provides a cured product which has excellent adhesion suitable for a temporary fixing material.

This composition contains (A) 100 parts of an organopolysiloxane having two groups represented by general formula (1) ##STR00001## (R.sup.1 represents a monovalent hydrocarbon group having 1-20 carbon atoms, R.sup.2 represents an oxygen atom or the like, R.sup.3 represents an acryloyloxyalkyl group or the like, p represents a number satisfying 0≤p≤10, and “a” represents a number satisfying 1≤a≤3) per molecule, (B) 1-500 parts of a monofunctional (meth)acrylate compound not containing a siloxane structure, (C) 1-5,000 parts of an organopolysiloxane resin containing (a) an R.sup.4.sub.3SiO.sub.1/2 unit (in the formula, R.sup.4 represents a monovalent hydrocarbon group having 1-10 carbon atoms) and (b) a SiO.sub.4/2 unit, where the molar ratio of the unit (a) to the unit (b) is in the range of 0.6 to 1.2:1, (D) 1-100 parts of fine powder silica, and (E) 0.01-20 parts of an optical polymerization initiator. The compound has good shape retention properties and curability for irradiation with ultraviolet light, and provides a cured product which has excellent adhesion suitable for a temporary fixing material.

Described herein is an actinically curable adhesive composition, suitable for sealing flexible packaging, that includes an inert urethane polymer and an ethylenically unsaturated monomer component selected from at least one monofunctional ethylenically unsaturated monomer, at least one multifunctional ethylenically unsaturated monomer, and a combination thereof, wherein the ethylenically unsaturated monomer component disperses the inert urethane polymer. The compositions are suitable for forming flexible packaging materials for foods and other materials, particularly sensitive materials. Also described are flexible packaging materials and a method for preparing an actinically curable adhesive composition.