Thermochromic pigment composition

Patent metadata

Field	Value
Publication number	US-11629256-B2
Application number	US-201816486778-A
Country	US
Kind code	B2
Filing date	Feb 16, 2018
Priority date	Feb 17, 2017
Publication date	Apr 18, 2023
Grant date	Apr 18, 2023

Abstract

A thermochromic pigment composition comprising: (A) at least one electron-donor organic dye compound, (B) at least one electron-acceptor compound, and (C) at least one compound. The thermochromic pigment composition is microencapsulated and is useable in writing instruments.

First claim

The invention claimed is:

1. Thermochromic pigment composition comprising:
(A) at least one electron-donor organic dye compound,
(B) at least one electron-acceptor compound, and
(C) at least one compound serving as a reaction medium capable of bringing about a reversible electron-acceptance/donation reaction attributable to compounds (A) and (B), the at least one compound including:

wherein:
n=0-2, and
m=5-19

wherein the thermochromic pigment composition has
(A) from 1 to 10% by weight of the at least one electron-donor organic dye compound,
(B) from 1 to 20% by weight of the at least one electron-acceptor compound, and
(C) from 70 to 98% by weight of the at least one compound including formula (I) based on the total weight of the thermochromic pigment composition.

2. The thermochromic pigment composition according to claim 1 , wherein a compound of formula (I) is chosen from one of the following compounds:

3. The thermochromic pigment composition according to claim 1 , comprising:
(A) from 2 to 4% by weight of the at least one electron-donor organic dye compound,
(B) from 4 to 10% by weight of the at least one electron-acceptor compound, and
(C) from 86 to 94% by weight of the at least one compound including formula (I) based on the total weight of the thermochromic pigment composition.

4. The thermochromic pigment composition according to claim 1 , wherein the electron-donor organic dye is selected from the group consisting of 3-(4-diethylamino-2-ethoxyphenyl)-3-(1-ethyl-2-methylindol-3-yl)-4-azaphthalide (Blue 63), 2′-(dibenzylamino)-6′-(diethylamino) fluorane, N,N-dimethyl-4-[2-[2-(octyloxy)phenyl]-6-phenyl-4-pyridinyl]benzenamine (Yellow CK37), 7-(4-diethylamino-2-hexyloxyphenyl)-7-(1-ethyl-2-methyl-1H-indol-3-yl)-7H-furo[3,4-b]pyridine-5-one (Blue 203), 2-(2,4-dimethylphenylamino)-3-methyl-6-diethylaminofluoran (Black 15) and 3,3,-bis-(1-butyl-2-methyl-indol-3-yl)-3H-isobenzofuran-1-one (Red 40).

5. The thermochromic pigment composition according to claim 1 , wherein the electron-acceptor is selected from the group consisting of 2,2-bis(4-hydroxy-3-methylphenyl)propane (Bisphenol C), 4-hexyl-1,3-dihydroxybenzene (4-hexylresorcinol), 4,4′-cyclohexylidenebisphenol (BZP), 4,4′-(hexafluoroisopropylidene) diphenol (Bisphenol AF), 4,4′-(1-phenylethylidene) bisphenol, 2,2′-dihydroxybiphenyl, 4,4′-(1,4-phenylenediisopropylidene) bisphenol, 1,1-bis(4-hydroxy-3-methylphenyl) cyclohexane, 9,9-bis(4-hydroxyphenyl) fluorine, 4,4′-(1,3-phenylenediisopropylidene) bisphenol, 1,1,1-tris(4-hydroxyphenyl) ethane, 4,4′-(2-ethylhexylidene) diphenol, and α,α,α′-tris(4-hydroxyphenyl)-1-ethyl-4-isopropylbenzene.

6. A microencapsulated thermochromic pigment comprising a composition according to claim 1 .

7. An ink composition comprising the microencapsulated thermochromic pigment according to claim 6 .

8. A writing instrument comprising an ink composition according to claim 7 .

9. The writing instrument according to claim 8 , wherein the writing instrument is selected from the group consisting of pens, friction-erasable ink pens, ballpoint pens, pencils, and chalks.

10. The writing instrument according to claim 9 , wherein the writing instrument includes a friction element.

11. The writing instrument according to claim 9 , wherein the writing instrument includes an eraser.

12. A method of writing, comprising contacting a writing instrument including the microencapsulated thermochromic pigment composition of claim 6 with a media.

13. A method of writing, comprising contacting a writing instrument including the thermochromic pigment composition of claim 1 with a media.

14. Thermochromic pigment composition comprising:
(A) at least one electron-donor organic dye compound,
(B) at least one electron-acceptor compound, and
(C) at least one compound including:

wherein:
n=0-2,
m=5-19,

wherein when m=17, n≠2.

15. Thermochromic pigment composition comprising:
(A) at least one electron-donor organic dye compound,
(B) at least one electron-acceptor compound, and
(C) at least one compound including:

16. A method for making a thermochromic pigment composition, comprising: admixing
(A) at least one electron-donor organic dye compound,
(B) at least one electron-acceptor compound, and
(C) at least one compound serving as a reaction medium capable of bringing about a reversible electron-acceptance/donation reaction attributable to compounds (A) and (B), the at least one compound including:

wherein:
n=0-2, and
m=5-19.

Assignees

• SOCIéTé BIC

Inventors

• Debrauwer Christelle
• Damiano Anne-Lise
• Bourque Alexander

Classifications

• C09B11/04 Primary

  derived from triarylmethanes {, i.e. central C-atom is substituted by amino, cyano, alkyl} · CPC title

• C09B67/0097 Primary

  Dye preparations of special physical nature; Tablets, films, extrusion, microcapsules, sheets, pads, bags with dyes · CPC title

• C09K9/02

  Organic tenebrescent materials · CPC title

• C09B11/08 Primary

  Phthaleins; {Phenolphthaleins; Fluorescein} · CPC title

• B43K7/00 Primary

  Ball-point pens ({B43M11/085 takes precedence}; multiple-point writing implements B43K27/00) · CPC title