Invisible logos using hydrophobic and hydrophilic coatings on substrates

• US 20030207090A1
• Filed: 04/30/2003
• Published: 11/06/2003
• Est. Priority Date: 05/01/2002
• Status: Active Grant

• Current Assignee: Technology and Innovation Fund LP
• Original Assignee: Technology and Innovation Fund LP
• Inventors: Arora, Pramod K.
• Granted Patent: US 7,048,971 B2
• Time in Patent Office: Days
• US Class Current: 428/195.1
• CPC Class Codes: B05D 5/00 Processes for applying liquids or other fluent materials to surfaces to obtain special surface effects, finishes or structures
• CPC Class Codes: B05D 5/08 to obtain an anti-friction or anti-adhesive surface rendering particulate materials free-flowing in general, e.g. making them hydrophobic B01J2/30
• CPC Class Codes: B41M 3/14 Security printing securities B42D25/29
• CPC Class Codes: Y10T 428/24802 Discontinuous or differential coating, impregnation or bond [e.g., artwork, printing, retouched photograph, etc.]

Abstract

Disclosed are invisible logos, undetectable to the human eye, that may be temporarily viewed in response to stimuli. The invisible logo may be made by forming a hydrophilic coating and a hydrophobic coating on a substrate surface, so that a portion of the hydrophilic coating and a portion of the hydrophobic coating are exposed.

Claims

1. A substrate having an invisible logo undetectable to a human eye, comprising:

the substrate having a surface;

a hydrophilic coating over a first portion of the substrate surface; and

a hydrophobic coating comprising an amphiphilic material over a second portion of the substrate surface, the hydrophobic coating capable of undergoing a temporary, visible change in response to stimuli thereby forming a visible logo detectable by a human eye;

wherein the hydrophilic coating and the hydrophobic coating are positioned to form the invisible logo.

2. The substrate of claim 1, the hydrophilic coating comprising at least one from the group consisting of silica, titania, alumina, chromia, tantalum oxide, zirconia, yttria, zinc oxide, magnesia, vanadia, indium oxide, tin oxide, germanium oxide, hafnium oxide, potassium oxide, sodium oxide, calcium oxide, silicon nitride, titanium nitride, tantalum nitride, carbon nitride, boron nitride, hafnium nitride, zirconium nitride, silicon oxynitride, boron carbide, silicon carbide, germanium carbide, magnesium fluoride, tetraethylorthosilicate, phosphosilicate glass, fluorosilicate glass, borophosphosilicate glass, borophospho-tetraethylorthosilicate, germanium phosphosilicate, germanium posophosphosilicate, tetramethoxysilane, and tetraethoxysilane.

3. The substrate of claim 1, the hydrophobic coating comprising at least one from the group consisting of polymerizable amphiphilic molecules, hydrolyzable alkyl silanes, hydrolyzable perhaloalkyl silanes, chlorosilanes, polysiloxanes, alkyl silazanes, perfluoroalkyl silazanes, disilazanes, silsesquioxanes, and polyhedral oligomeric silsesquioxanes.

4. The substrate of claim 1, the amphiphilic material comprising at least one from the group consisting of

an amphiphilic molecule represented by Formula II:

R_mSH_n 

 

(II)

where R is an alkyl, fluorinated alkyl, an alkyl ether or a fluorinated alkyl ether containing from about 1 to about 30 carbon atoms;

S is sulfur;

H is hydrogen;

m is from about 1 to about 2 and n is from 0 to 1;

an amphiphilic molecule represented by RY, where R is an alkyl, fluorinated alkyl, an alkyl ether or a fluorinated alkyl ether containing from about 1 to about 30 carbon atoms and Y is one of —

COOH, —

SO₃H, —

PO₃, —

OH, and —

NH₂;

an amphiphilic molecule represented by one of Formulae (III) and (IV);

CF₃(CF₂)₇CH₂CH₂—

Si(CH₃)₂Cl 

 

(III)CF₃(CF₂)₇CH₂CH₂—

Si(OEt)₃ 

 

(IV);

an amphiphilic molecule represented by Formula V;

RSiNSiR 

 

(V)

where R is an alkyl, fluorinated alkyl, an alkyl ether or a fluorinated alkyl ether containing from about 1 to about 30 carbon atoms; and

an amphiphilic molecule represented by Formula VI;

R(CH₂CH₂O)_qP(O)_x(OH)_y 

 

(VI)

where R is an alkyl, fluorinated alkyl, an alkyl ether or a fluorinated alkyl ether containing from about 1 to about 30 carbon atoms, q is from about 1 to about 10, and x and y are independently from about 1 to about 4.

5. The substrate of claim 1, the hydrophilic coating having a thickness from about 0.1 nm to about 250 nm and the hydrophobic coating having a thickness from about 0.1 nm to about 250 nm.

6. The substrate of claim 1, the substrate comprising at least one from the group consisting of glasses, paper, marble, ceramics, porcelains, fiberglass, metals, thermosets, and thermoplastics.

7. A lens having an invisible logo undetectable to a human eye, comprising:

the lens substrate having a surface;

a hydrophilic coating over a first portion of the lens substrate surface; and

a hydrophobic coating comprising an amphiphilic material over a second portion of the lens substrate surface, the hydrophobic coating capable of undergoing a temporary, visible change in response to stimuli thereby forming a visible logo detectable by a human eye;

wherein the hydrophilic coating and the hydrophobic coating are positioned to form the invisible logo.

8. The lens of claim 7, the hydrophilic coating comprising at least one from the group consisting of metal oxides, metal nitrides, metal carbides, metal fluorides, and silicates.

9. The lens of claim 7, the hydrophobic coating comprising at least one from the group consisting of polymerizable amphiphilic molecules, hydrolyzable alkyl silanes, hydrolyzable perhaloalkyl silanes, chlorosilanes, polysiloxanes, alkyl silazanes, perfluoroalkyl silazanes, disilazanes, silsesquioxanes, and polyhedral oligomeric silsesquioxanes.

10. The lens of claim 7, the lens substrate comprising at least one from the group consisting of an eyewear lens, a microscope slide, a binocular lens, a microscope lens, a telescope lens, a camera lens, and a video lens.

11. A method of making an invisible logo undetectable to a human eye on a substrate, comprising:

forming a hydrophilic coating over a first portion of the substrate; and

forming a hydrophobic coating comprising an amphiphilic material over a second portion of the substrate, the hydrophobic coating capable of undergoing a temporary, visible change in response to stimuli thereby forming a visible logo detectable by a human eye;

wherein the hydrophilic coating and the hydrophobic coating are positioned to form the invisible logo.

12. The method of claim 11, the hydrophilic coating is formed by one selected from the group consisting of wet application;

vapor deposition;

vacuum deposition;

vacuum coating;

box coating;

sputter coating;

chemical vapor deposition;

sputtering; and

spin-on techniques.

13. The method of claim 11, the hydrophobic coating is formed by one selected from the group consisting of wet application;

vapor deposition;

vacuum deposition;

vacuum coating;

box coating;

sputter coating;

chemical vapor deposition;

sputtering; and

pin-on techniques.

14. The method of claim 11, the hydrophobic coating is formed by vapor deposition using a porous carrier.

15. The method of claim 11, the hydrophilic coating is formed over a substantial portion of the substrate, a mask with openings corresponding to the invisible logo exposing portions of the hydrophilic coating is formed over the hydrophilic coating, oxidizing the exposed portions of the hydrophilic hydrophobic coating to form a hydrophobic coating within the openings of the mask, and removing mask from the substrate.

16. The method of claim 11, the hydrophilic coating is formed over a substantial portion of the substrate, a mask with openings corresponding to the invisible logo is formed over the hydrophilic coating, the hydrophobic coating is formed within the openings of the mask, and mask is removed from the substrate.

17. The method of claim 11, the hydrophilic coating is formed over a substantial portion of the substrate, the hydrophobic coating is formed over the hydrophilic coating, and an etching solution is contacted with portions of the hydrophobic coating to remove those portions of the hydrophobic coating.

18. A method of making an invisible logo undetectable to a human eye on a substrate, comprising:

forming a hydrophobic coating over a first portion of the substrate, the hydrophobic coating comprising an amphiphilic material, the hydrophobic coating capable of undergoing a temporary, visible change in response to stimuli thereby forming a visible logo detectable by a human eye; and

forming a hydrophilic coating over a second portion of the substrate;

wherein the hydrophilic coating and the hydrophobic coating are positioned to form the invisible logo.

19. The method of claim 18, the hydrophobic coating is formed by one of vapor deposition or wet application.

20. The method of claim 18, the hydrophilic coating is formed by one selected from the group consisting of vacuum deposition;

vacuum coating;

sputter coating; and

chemical vapor deposition.