ITTO20000004A1 - COLORED PAPER THAT CHANGES COLOR. - Google Patents

Description

Description of the industrial invention entitled:

"Colored paper that changes color".

DESCRIPTION

The present invention relates to a colored paper which changes color, ie undergoes a toning, upon the passage of a reducing substance.

There are known papers impregnated with colored ink capable of turning to a different color when placed in contact with a reducing substance.

Thanks to the impregnation of the paper with an ink capable of turning and the subsequent use of a pen containing the reducing substance, which can advantageously be a transparent substance, it is possible to obtain surprising effects on the inked paper such as written and colored fantasy signs. The aforementioned cards capable of changing color therefore find particular application in the field of drawing and playing cards for children.

According to the known technique described in the Italian patent for industrial invention No. 1157992, monochromatic colored papers have been produced which, upon passing a pen or changer containing the reducing substance, change their color to a different color.

According to the teaching of the cited patent, for example, blue-colored papers have been produced, which take on a white color when the reducing pen passes, or yellow-colored papers that turn red when the changer passes or, again, bright green papers that allow to obtain white lettering and signs.

The object of the present invention is to provide a new paper which changes color upon contact with a reducing substance, with an even more surprising effect than known papers.

This and other purposes are achieved with the paper which changes color, as claimed in the appended claims.

The invention will now be described with reference to the attached drawings, relating to preferred but not limiting embodiments of the invention, in which:

Fig.1 illustrates a card according to the invention in a first example of use; And

Fig.2 illustrates a card according to the invention in a second example of use.

With reference to Figure 1 there is provided a paper F inked with four different inks which change to different colors, but which are substantially of the same color before the color change.

In the illustrated example, the four inks are all blue and are used to impregnate corresponding adjacent strips of paper I1-I4 by printing. Once inked, the paper will therefore be monochromatic, but as the reducing solution passes it will assume a surprisingly different color depending on the ink used to impregnate the corresponding strip.

In the example shown in the figure, when the pen P containing the reducing solution passes along the R curve, the r1-r5 portions of the R curve will change to four different colors.

Figure 2 illustrates a second example of use of the invention in which on the sheet G, inked in parallel strips M1-M4 with corresponding four inks of the same color, but which change to different colors, a t-shirt was represented whose A1-A4 areas will have different colors due to the reducing ink effect.

According to the invention, the ink used comprises:

a dye, chosen for example from the "Color Index" dyes Acid Blue 93: 2, Solvent Green 7, Reactive Blue 116, Reactive Red 24, in a concentration between 1 and 10%;

a thickening resin, for example a polyvinylpyrrolidone, a carboxymethylcellulose or a hydroxymethylcellulose in a concentration between 10 and 40%;

- an organic acid in a concentration between 0.1 and 3%;

water in a concentration between 50 and 90%.

The reducing substance will be a reducing ink with a basic pH.

The colors that can be obtained as a result of the toning are pink, fluorescent green, fluorescent yellow, turquoise and orange.

However, it is also possible to obtain a greater number of colors by suitably combining the described dyes together.

Furthermore, still according to the invention it will be possible to impregnate by printing portions of paper other than strips, such as particular shapes and marks, to obtain different ornamental effects when the inks change color.

Although the invention has been illustrated with reference to a currently preferred example, it is generally susceptible of other applications and modifications which are understood to be included in the protective scope, as will be evident to those skilled in the art.

Claims (8)

CLAIMS 1. Inked paper that changes color, that is, it changes in contact with a reducing substance, characterized by the fact that on said paper at least two areas inked with different inks are defined, but of the same color before the color change, and that said areas turn to different colors between them when placed in contact with a reducing substance. 2. Card according to claim 1, wherein said zones are four in number or multiples thereof. Paper according to claim 2, wherein each zone is inked with an ink comprises: a dye in a concentration of between 1 and 10%; a thickening resin in a concentration comprised between 10 and 40%; an organic acid in a concentration of between 0.1 and 3%; water in a concentration between 50 and 90%. 4. Paper according to claim 3, wherein said dye is selected from the "Color Index" group: Acid Blue 93: 2, Solvent Green 7, Reactive Blue 116, Reactive Red 24. 5. Paper according to claim 4, wherein said resin is selected from the group of: polyvinylpyrrolidone, carboxymethylcellulose, hydroxymethylcellulose. 6. A paper according to claim 3, wherein said ink is blue in color before the color change. 7. Paper according to claim 6, wherein said ink changes to a color comprised in the group of: pink, fluorescent green, fluorescent yellow, turquoise and orange. 8. Paper according to any one of the preceding claims in which said areas are parallel strips.