Coating film

Patent metadata

Field	Value
Publication number	US-11629218-B2
Application number	US-201917273534-A
Country	US
Kind code	B2
Filing date	Oct 31, 2019
Priority date	Oct 31, 2018
Publication date	Apr 18, 2023
Grant date	Apr 18, 2023

Abstract

The present invention provides a coating film having a structure represented by the following general formula (1) (in the formula, R 11 is a residue formed by removing one isocyanate group from a polyisocyanate, and R 12 is an alkyl group or an alkoxy group having 2 to 12 carbon atoms, R 13 is a residue formed by removing one hydroxyl group from a polyol), wherein a König hardness of the coating film is 20 or more, in an SS curve measurement of a tensile test, the coating film has an elastic deformation region and a plastic deformation region, and in the SS curve measurement, a stress at an inflection point stress between the elastic deformation region and the plastic deformation region is 5 MPa or more.

First claim

The invention claimed is:

1. A coating film having a structure represented by the following general formula (1), wherein
a König hardness of the coating film is 20 or more,
in an SS curve measurement of a tensile test, the coating film has an elastic deformation region and a plastic deformation region,
in the SS curve measurement, a stress at an inflection point stress between the elastic deformation region and the plastic deformation region is 5 MPa or more,
the coating film is formed by curing a coating composition containing a blocked polyisocyanate component and a polyol,
in the coating composition, a molar ratio of the isocyanate group of the blocked polyisocyanate component to a hydroxyl group of the polyol is 0.4 or more and 2.0 or less, and
the blocked polyisocyanate component contains a blocked polyisocyanate obtained from a polyisocyanate and a compound represented by the following general formula (3),

wherein, in (the general formula (1), R 11 is a residue formed by removing one isocyanate group from any one of isocyanurate-type polyisocyanates, biuret-type polyisocyanates, urethane-modified isocyanurate-type polyisocyanates, and allophanate-type polyisocyanates, R 12 is a secondary alkoxy group or a tertiary alkoxy group having 2 to 12 carbon atoms, R 13 is an alkyl group,

wherein, in the general formula (3), R 31 is an alkyl group, and R 32 is a secondary alkoxy group or a tertiary alkoxy group having 2 to 12 carbon atoms.

2. The coating film according to claim 1 , wherein the stress at an inflection point is 20 MPa or more.

3. The coating film according to claim 1 , wherein the molar ratio of the isocyanate group of the polyisocyanate component to the hydroxyl group of the polyol is 0.4 or more 1.0 or less.

4. The coating film according claim 1 , wherein R 31 is a secondary alkyl group or a tertiary alkyl group.

5. The coating film according to claim 1 , wherein R 31 is a tertiary alkyl group.

6. The coating film according to claim 1 , wherein R 32 is a tertiary alkoxy group having 2 to 12 carbon atoms.

7. A method for producing a coating film, comprising:
applying a coating composition containing a blocked polyisocyanate component and a polyol and drying at 100 to 200° C. for 10 to 60 minutes or at 70 to 90° C. for 1 to 14 days, wherein
in the coating composition, a molar ratio of the isocyanate group of the blocked polyisocyanate component to a hydroxyl group of the polyol is 0.4 or more and 2.0 or less, and
the blocked polyisocyanate component contains a blocked polyisocyanate obtained from a polyisocyanate and a compound represented by the following general formula (3),

wherein, in (the general formula (3), R 31 is an alkyl group, and R 32 is a secondary alkoxy group or a tertiary alkoxy group.

8. The method for producing a coating film according to claim 7 , wherein the molar ratio of the isocyanate group of the blocked polyisocyanate component to the hydroxyl group of the polyol is 0.4 or more and 1.0 or less.

9. The method for producing a coating film according to claim 7 , wherein R 32 has 2 to 12 carbon atoms.

Assignees

• Asahi Chemical Ind

Inventors

• Tanaka Eiko
• Azuma Koichiro

Classifications

• C08G18/80

  Masked polyisocyanates · CPC title

• C08G18/73

  acyclic · CPC title

• C08G18/792

  formed by oligomerisation of aliphatic and/or cycloaliphatic isocyanates or isothiocyanates · CPC title

• C08G18/022 Primary

  the polymeric products containing isocyanurate groups · CPC title

• C08G18/2865

  Compounds having only one primary or secondary amino group; Ammonia · CPC title