Peelable ink composition with color-changing for porous substrates
An aqueous peelable ink composition with color-changing comprises: at least one film-forming elastomeric polymer, at least one polyoxyethylene sorbitan ester, at least one dye, at least one pigment, and water, wherein the film-forming elastomeric polymer (a) is acrylonitrile butadiene rubber (NBR) and/or hydrogenated acrylonitrile butadiene rubber (HNBR).
1 . An ink composition comprising:
(a) at least one film-forming elastomeric polymer,
(b) at least one polyoxyethylene sorbitan ester,
(c) at least one dye,
(d) at least one pigment, and
(e) water,
wherein the at least one film-forming elastomeric polymer (a) includes hydrogenated acrylonitrile butadiene rubber (HNBR).
2 . The ink composition according to claim 1 , wherein the at least one polyoxyethylene sorbitan ester (b) is a polyoxyethylene sorbitan fatty acid ester.
3 . The ink composition according to claim 1 , wherein the at least one dye (c) is chosen in the group consisting of direct dyes, acid dyes, food dyes, Malachite green (C.I 4200) Victoria blue FB (C.I. 44045) methyl violet FN (C.I. 42535), rhodamine F4G (C.I. 45160), and rhodamine 6GCP (C.I 45160), and mixtures thereof.
4 . The ink composition according to claim 3 , wherein the at least one pigment (d) is provided as a pigment dispersion.
5 . The ink composition according to claim 1 , wherein the composition further comprises at least one plasticizer.
6 . The ink composition according to claim 5 , wherein the at least one plasticizer is chosen in the group consisting of alcohols, benzoate esters, diisobutyrate esters, and mixtures thereof.
7 . The ink composition according to claim 5 , wherein the at least one plasticizer is present in a content ranging from 1 to 25% by weight, relative to the total weight of the ink composition.
8 . The ink composition according to claim 1 , wherein the content of the at least one film-forming elastomeric polymer (a) represents at least 8% by weight, relative to the total weight of the ink composition.
9 . The ink composition according to claim 1 , wherein the content of the at least one polyoxyethylene sorbitan ester (b) ranges from 0.1 to 5% by weight, relative to the total weight of the ink composition.
10 . The ink composition according to claim 1 , wherein the total content of the at least one dye (c) ranges from 0.1 to 10% by weight, relative to the total weight of the ink composition.
11 . The ink composition according to claim 4 , wherein the content of the at least one pigment d) provided as a pigment dispersion ranges from 0.1 to 10% by weight, relative to the total weight of the ink composition.
12 . The ink composition according to claim 1 , wherein the content of water (e) ranges from 10 to 80% by weight, relative to the total weight of the ink composition.
13 . The ink composition according to claim 1 , wherein the composition further comprises at least one additive chosen in the group consisting of antimicrobial agents, antifungal agents, dispersing agents, wetting agents, pH regulators, and mixtures thereof.
14 . The ink composition according to claim 1 , wherein the ink composition is able to change its initial color to another color by peeling.
15 . A method for preparing the ink composition according to claim 1 , comprising the steps of:
(i) under stirring, adding the at least one dye (c) to the water (e),
(ii) under stirring, adding the at least one film-forming elastomeric polymer (a) to the mixture obtained in step (i),
(iii) under stirring, adding the at least one polyoxyethylene sorbitan ester (b), the at least one pigment (d), and optionally at least one plasticizer, to the mixture obtained in step (ii), and
(iv) under stirring, adding optional additives to the mixture obtained in step (iii), wherein the additives are chosen in the group consisting of antimicrobial agents, antifungal agents, dispersing agents, wetting agents, pH regulators, and mixtures thereof.
16 . A writing instrument containing the ink composition according to claim 1 , wherein the writing instrument is a pen.
17 . The writing instrument according to claim 16 , wherein the writing instrument comprises an eraser.
18 . A method for writing on a porous substrate, comprising the step of applying the ink composition according to claim 1 to a porous substrate.
19 . The method according to claim 18 , wherein the method further comprises changing the initial color (first color) of the writing into another color (second color) by peeling.
20 . The ink composition according to claim 1 , wherein the at least one film-forming elastomeric polymer (a) includes acrylonitrile butadiene rubber (NBR).