Hardcoat composition comprising methyl or ethyl trialkoxy silane, articles and methods

Patent metadata

Field	Value
Publication number	US-12486373-B2
Application number	US-202118026268-A
Country	US
Kind code	B2
Filing date	Sep 23, 2021
Priority date	Oct 8, 2020
Publication date	Dec 2, 2025
Grant date	Dec 2, 2025

Abstract

Articles are described comprising a substrate and a hardcoat layer disposed on the substrate. The hardcoat layer comprises the hydrolyzed and condensed reaction product of a composition comprising: i) first hydrophobic silane monomer(s) having the formula R 1 Si(OR) 3 wherein R and R 1 is methyl or ethyl; ii) optional second silane monomer(s) having the formula (R 2 ) 4-m Si(OR) m or Si(OR) 4 , wherein R, R 1 and R 2 are organic groups with the proviso that R 1 is not methyl or ethyl and m ranges from 1 to 3. The hardcoat layer may further comprises 10 to 30 wt. % silica nanoparticles. A surface layer comprising a hydrophilic silane may be disposed on the hardcoat layer. Also described is a method of using an article having a rewritable surface, hardcoat coating compositions, and methods of making hardcoat compositions and articles.

First claim

What is claimed is:

1 . An article comprising:
A) a substrate; B) a hardcoat layer disposed on the substrate wherein the hardcoat layer comprises the hydrolyzed and condensed reaction product of a composition comprising:
i) first hydrophobic silane monomer(s) having the formula R 1 Si(OR) 3 wherein R and R 1 is methyl or ethyl;
ii) optional second silane monomer(s) having the formula (R 2 ) 4-m Si(OR) m or Si(OR) 4
wherein R, R 1 and R 2 are organic groups with the proviso that R 2 is not methyl or ethyl and m ranges from 1 to 3;
wherein when present, the second silane monomer(s) is present in an amount less than 20 wt. % based on the sum of first and second silane monomers;
iii) optionally 10 to 30 wt. % silica nanoparticles;
C) a surface layer comprising a hydrophilic silane disposed on the hardcoat layer.

2 . The article of claim 1 wherein said hydrophilic silane comprises a zwitterionic silane.

3 . The article of claim 2 wherein the surface layer further comprises lithium silicate, sodium silicate, potassium silicate, or combinations thereof.

4 . The article of claim 1 wherein the hardcoat layer comprises silica nanoparticles have an average primary particle size of less than 25, 15, or 10 nm.

5 . The article of claim 1 wherein the first silane monomer(s) is present in at amount of at least 85, 90, or 95 wt. % based on the sum of first and second silane monomers.

6 . The article of claim 1 wherein the hardcoat layer comprises silica nanoparticles that comprise a hydrophilic silane surface treatment.

7 . The article of claim 6 wherein the hydrophilic silane surface treatment is an epoxy alkoxy silane.

8 . The article of claim 1 wherein the substrate comprises an organic polymeric material.

9 . The article of claim 1 wherein the surface layer is a rewritable surface.

10 . The article of claim 9 wherein the article is a dry erase board or film, label, file folder, file tab, or notebook cover or divider.

11 . A method of using an article having a rewritable surface comprising:
providing an article according to claim 1 ; writing on the rewritable surface layer with a marker; and removing the writing.

12 . The method of claim 11 wherein said hydrophilic silane comprises a zwitterionic silane.

13 . The method of claim 11 wherein the surface layer further comprises lithium silicate, sodium silicate, potassium silicate, or combinations thereof.

14 . The method of claim 11 wherein the hardcoat layer comprises silica nanoparticles have an average primary particle size of less than 25, 15, or 10 nm.

15 . The method of claim 11 wherein the first silane monomer(s) is present in at amount of at least 85, 90, or 95 wt. % based on the sum of first and second silane monomers.

16 . The method of claim 11 wherein the hardcoat layer comprises silica nanoparticles that comprise a hydrophilic silane surface treatment.

17 . The method of claim 16 wherein the hydrophilic silane surface treatment is an epoxy alkoxy silane.

18 . The method of claim 11 wherein the substrate comprises an organic polymeric material.

19 . The method of claim 11 wherein the surface layer is a rewritable surface.

20 . The method of claim 19 wherein the article is a dry erase board or film, label, file folder, file tab, or notebook cover or divider.

21 . The method of claim 11 wherein the marker is a permanent marker.

22 . The method of claim 11 wherein removing the writing comprises wiping the rewritable surface with a dry eraser, dry cloth or dry paper towel.

Assignees

• 3M Innovative Properties Company

Inventors

• Jing Naiyong
• Tian Xue
• Ma Jun
• Ducharme Jordan C
• Damte Gezahegn D
• Chen Xi

Classifications

• C09D183/06

  containing silicon bound to oxygen-containing groups (C09D183/12 takes precedence) · CPC title

• C08K5/541

  containing oxygen · CPC title

• C08K3/36

  Silica · CPC title

• C08J2367/02

  Polyesters derived from dicarboxylic acids and dihydroxy compounds; (C08J2367/06 takes precedence) · CPC title

• C08G77/18

  to alkoxy or aryloxy groups · CPC title