Adhesive for endoscope, cured product, endoscope, and method for producing endoscope

1. A method, comprising:

fixing at least one of a metal member or a glass member constituting an endoscope with a two-component adhesive,

the two-component adhesive comprising:

a base that includes at least one epoxy resin (A) selected from the group consisting of bisphenol A epoxy resins, bisphenol F epoxy resins, and phenol novolac epoxy resins; and

a curing agent that includes at least one polyamine compound (B) represented by general formula (I) or (II),

H 2 N-L 1 NH 2 ) n   general formula (I)

H 2 N-L 3 -L 2 -L 4 -NH 2   general formula (II)

where in general formula (I), n represents an integer of 1 to 3, and L 1 represents an aliphatic or alicyclic hydrocarbon group with a valence of (n+1), an aromatic hydrocarbon group with a valence of (n+1), or a group with a valence of (n+1) having an aliphatic hydrocarbon chain into which at least one oxygen atom is incorporated, provided that when n is 1, the aliphatic or alicyclic hydrocarbon group represented by L 1 is a linear alkylene group having 5 to 12 carbon atoms, a cyclic alkylene group having 5 to 12 carbon atoms, or an alkylene group having 5 to 12 carbon atoms constituted by a linear alkylene group and a cyclic alkylene group, and when n is 1 and the hydrocarbon group is an alicyclic saturated hydrocarbon group, the alicyclic saturated hydrocarbon group does not include a quaternary carbon atom as an annular atom, and

in general formula (II), L 2 represents an alkylene group having 2 or more carbon atoms, —O—, or a divalent group having a combination thereof, and L 3 and L 4 each independently represent an arylene group, and

wherein the at least one polyamine compound (B) does not include xylylenediamine.

2. The method according to claim 1 , wherein the adhesive fixes a member in a tip portion of an insertion section of the endoscope.

3. The method according to claim 2 , wherein the adhesive seals peripheries of an observation window and an illumination window in the tip portion of the insertion section of the endoscope.

4. The method according to claim 2 , wherein the adhesive fixes a prism in an optical device constituting the endoscope.

5. The method according to claim 1 , wherein the adhesive is a mixture of the base and the curing agent with the polyamine compound (B) being present in an amount of 10 to 75 parts by mass based on 100 parts by mass of the epoxy resin (A).

6. A cured product, comprising the adhesive that was formed by curing the adhesive that fixes the at least one of a metal member or a glass member according to the method of claim 1 .

7. The method according to claim 1 , wherein

in a case where L 1 represents an aromatic hydrocarbon group with a valence of (n+1) and n is 1, the aromatic hydrocarbon group is an arylene group;

in a case where L 1 represents an aromatic hydrocarbon group with a valence of (n+1) and n is 2, the aromatic hydrocarbon group is an arenetriyl group; and

in a case where L 1 represents an aromatic hydrocarbon group with a valence of (n+1) and n is 3, the aromatic hydrocarbon group is an arenetetrayl group.

8. The method according to claim 7 , wherein

the arylene group is a phenylene group or a naphthylene group,

the arenetriyl group is a benzenetriyl group or a naphthalenetriyl group, and

the arenetetrayl group is a benzenetetrayl group or a naphthalenetetrayl group.

9. An endoscope comprising:

at least one of a metal member or a glass member,

wherein the at least one of the metal member or the glass member is fixed with a two-component adhesive by curing the two-component adhesive,

the two-component adhesive comprising:

a base that includes at least one epoxy resin (A) selected from the group consisting of bisphenol A epoxy resins, bisphenol F epoxy resins, and phenol novolac epoxy resins; and

a curing agent that includes at least one polyamine compound (B) represented by general formula (I) or (II),

H 2 N-L 1 NH 2 ) n   general formula (I)

H 2 N-L 3 -L 2 -L 4 -NH 2   general formula (II)

where in general formula (I), n represents an integer of 1 to 3, and L 1 represents an aliphatic or alicyclic hydrocarbon group with a valence of (n+1), an aromatic hydrocarbon group with a valence of (n+1), or a group with a valence of (n+1) having an aliphatic hydrocarbon chain into which at least one oxygen atom is incorporated, provided that when n is 1, the aliphatic or alicyclic hydrocarbon group represented by L 1 is a linear alkylene group having 5 to 12 carbon atoms, a cyclic alkylene group having 5 to 12 carbon atoms, or an alkylene group having 5 to 12 carbon atoms constituted by a linear alkylene group and a cyclic alkylene group, and when n is 1 and the hydrocarbon group is an alicyclic saturated hydrocarbon group, the alicyclic saturated hydrocarbon group does not include a quaternary carbon atom as an annular atom, and

in general formula (II), L 2 represents an alkylene group having 2 or more carbon atoms, —O—, or a divalent group having a combination thereof, and L 3 and L 4 each independently represent an arylene group, and

wherein the at least one polyamine compound (B) does not include xylylenediamine.

10. The endoscope according to claim 9 , wherein the adhesive fixes a member in a tip portion of an insertion section of the endoscope.

11. The endoscope according to claim 10 , wherein the adhesive seals peripheries of an observation window and an illumination window in the tip portion of the insertion section of the endoscope.

12. The endoscope according to claim 10 , wherein the adhesive fixes a prism in an optical device constituting the endoscope.

13. The endoscope according to claim 9 , wherein the adhesive is in the form of a mixture of the base and the curing agent with the polyamine compound (B) being present in an amount of 10 to 75 parts by mass based on 100 parts by mass of the epoxy resin (A).

14. A method for producing an endoscope, comprising:

fixing at least one of a metal member or a glass member with a two-component adhesive to form the endoscope,

the two-component adhesive comprising:

a base that includes at least one epoxy resin (A) selected from the group consisting of bisphenol A epoxy resins, bisphenol F epoxy resins, and phenol novolac epoxy resins; and

a curing agent that includes at least one polyamine compound (B) represented by general formula (I) or (II),

H 2 N-L 1 NH 2 ) n   general formula (I)

H 2 N-L 3 -L 2 -L 4 -NH 2   general formula (II)

where in general formula (I), n represents an integer of 1 to 3, and L 1 represents an aliphatic or alicyclic hydrocarbon group with a valence of (n+1), an aromatic hydrocarbon group with a valence of (n+1), or a group with a valence of (n+1) having an aliphatic hydrocarbon chain into which at least one oxygen atom is incorporated, provided that when n is 1, the aliphatic or alicyclic hydrocarbon group represented by L 1 is a linear alkylene group having 5 to 12 carbon atoms, a cyclic alkylene group having 5 to 12 carbon atoms, or an alkylene group having 5 to 12 carbon atoms constituted by a linear alkylene group and a cyclic alkylene group, and when n is 1 and the hydrocarbon group is an alicyclic saturated hydrocarbon group, the alicyclic saturated hydrocarbon group does not include a quaternary carbon atom as an annular atom, and

in general formula (II), L 2 represents an alkylene group having 2 or more carbon atoms, —O—, or a divalent group having a combination thereof, and L 3 and L 4 each independently represent an arylene group, and

wherein the at least one polyamine compound (B) does not include xylylenediamine.

15. The method according to claim 14 , wherein the adhesive fixes a member in a tip portion of an insertion section of the endoscope.

16. The method according to claim 15 , wherein the adhesive seals peripheries of an observation window and an illumination window in the tip portion of the insertion section of the endoscope.

17. The method according to claim 15 , wherein the adhesive fixes a prism in an optical device constituting the endoscope.

18. The method according to claim 14 , wherein the adhesive is in the form of a mixture of the base and the curing agent with the polyamine compound (B) being present in an amount of 10 to 75 parts by mass based on 100 parts by mass of the epoxy resin (A).