JP6896270B2 - Erasing colorant composition - Google Patents

Description

The present invention relates to an erasable colorant composition.

Pigment-containing compositions that can be erased by washing even if the colorant composition adheres to clothes or the like are known as described in Patent Documents 1 to 3 below.
The composition described as an example of Patent Document 1 contains a coloring pigment + a dispersion resin and anionic resins A and B, the dispersion resin is Joncryl678, and the anionic resin A is ammonia. The summed Joncryl 690 or methylamine neutralized HIROS X-1, the anionic resin B is triethanolamine neutralized Joncryl 690 or PVA.
The composition described as, for example, Example 2 of Patent Document 2 contains a black pigment dispersion (Joncryl678 neutralized with sodium hydroxide) and a styrene maleic acid copolymer neutralized with ethylamine. doing.
Further, the composition described as, for example, Example 2 of Patent Document 3 contains a black pigment dispersion (Joncryl 678 neutralized with sodium hydroxide) and Joncryl 690 neutralized with sodium hydroxide. ..

Japanese Unexamined Patent Publication No. 2007-186581 JP-A-2007-217538 Japanese Unexamined Patent Publication No. 2006-57084

According to the pigment-containing compositions described in Patent Documents 1 to 3 above, it was possible to certainly have a washing erasable property. However, the case where the washing erasability can be exhibited is limited, and the washing erasability can be exhibited when washing with a so-called basic detergent (pH about 10).
When such a detergent showing basicity of about pH 10 is used, the conventional pigment-containing composition showing washing erasability exhibits sufficient washing erasing property when a neutral washing detergent is used. Was difficult.
Furthermore, since it contained an alkali-soluble resin, the carbon black used was limited to those having a pH exceeding 6 from the viewpoint of maintaining good stability over time.
An object of the present invention is to obtain a colorant-containing composition exhibiting sufficient washing erasability when a laundry detergent having such a neutral property is used.

As a result of diligent studies to solve the above problems, the present inventors have been able to sufficiently exhibit washing erasability even when using a neutral laundry detergent, have excellent dispersion stability, and have a wider range. Carbon black can be used, and an erasable colorant composition in which the outline of characters does not blur after writing with carbon black can be obtained.
Specifically, it is as follows.
1. 1. 1.5 to 20.0% by weight of polyvinyl alcohol with a saponification degree of 70.0 to 95.0
An erasable colorant composition containing carbon black and water.
2. The scavenging colorant composition according to 1, wherein the polyvinyl alcohol has a viscosity of 30 mPa · s or less when made into an aqueous solution containing only polyvinyl alcohol in an amount of 4% by weight.
3. 3. The scavenging colorant composition according to 1 or 2, wherein the polyvinyl alcohol has a degree of polymerization of 300 to 1000.

According to the present invention, even if a neutral laundry detergent is used, the washing erasability can be sufficiently exhibited, the dispersion stability is excellent, a wider range of carbon black can be used, and the characters are written after writing the carbon black. It exerts the effect that it is possible to obtain an erasable coloring material composition in which the outline of the material does not blur.

Diagram showing the effect of handwriting Diagram showing the effect of handwriting Diagram showing the effect of handwriting Diagram showing the effect of hand washing Diagram showing the effect of hand washing Diagram showing the effect of hand washing

The erasable colorant composition of the present invention has an excellent erasable property that it can be washed off by washing with a neutral laundry detergent even after it has adhered to clothes and the like and dried. Even a colorant composition containing carbon black having a pH of 6 or less can achieve both sufficient erasability and excellent stability over time.

The specific composition of the erasable colorant composition of the present invention will be described below.
<Polyvinyl alcohol>
The polyvinyl alcohol that can be used in the present invention is not particularly limited, but one having a saponification degree of 70.0 to 95.0% is preferable in consideration of solubility, washing erasability and the like. When a plurality of types of polyvinyl alcohols are used, the saponification degree in the present invention is a weighted average of the saponification degrees in consideration of the concentration of each polyvinyl alcohol. If the saponification degree is less than 70.0, the rewriting property may be deteriorated, and if the saponification degree is 95.0 or more, the writing performance and the rewriting property may be deteriorated. Further, those having a degree of polymerization of 300 to 1000 are preferable.
Examples of the aqueous solution containing only 4% by weight of polyvinyl alcohol having a viscosity of 30 mPa · s or less include PVA102, 103, 104A, 105, 617, 706, 203, 205, 210, 217, 403, 405, L-. 8, L-9, L-10, 505, and among them, PVA203, 205, 403, 405, and 505 are preferable.
Such polyvinyl alcohol is preferably contained in an amount of 1.5 to 20.0% by weight, more preferably 1.5 to 10.0% by weight, based on the entire composition of the present invention. Yes, more preferably 5.0 to 10.0% by weight.
If the content of polyvinyl alcohol exceeds 20.0% by weight, the viscosity of the composition may become too high, resulting in poor brush transfer and poor water resistance.
Further, when the content of polyvinyl alcohol is less than 1.5% by weight, it may not be possible to exhibit sufficient washing erasability.

<Resin other than polyvinyl alcohol>
The resin other than polyvinyl alcohol that can be added in the erasable colorant composition of the present invention is a salt of a styrene-acrylic acid copolymer and / or a styrene-acrylic acid copolymer having a weight average molecular weight of about 7,000 to 20,000. The salt is an alkali metal salt or an ammonium salt, which can be used as long as it dissolves in the composition of the present invention and does not impair the effects of the present invention such as dispersibility of carbon black and wash erasability. By using such a styrene-acrylic acid copolymer in combination, there is a possibility that the effect of preventing bleeding of writing, the prevention of newspaper adhesion, and the improvement of surface appearance can be obtained.

<Carbon black>
The carbon black that can be used in the present invention is not particularly limited.
The pH range of carbon black is not limited to the range having characteristics as a coloring material.
Examples of carbon blacks that can be used include PRINTEX 75, 80, 85, 90, SPECIAL BLACK 4A, 6, Monarch 900, 800, CLOUR BLACK S170 and the like.
The content of carbon black is 0.5 to 20.0% by weight, preferably 1.0 to 10.0% by weight, based on the entire composition.
If the content exceeds 20.0% by weight, the amount of solid content is high, and as a result, the viscosity may become too high, and if the content is less than 0.5% by weight, it is sufficiently thick. It cannot be a black handwriting.

<Pigments other than carbon black>
Color pigments other than carbon black that can be added in the erasable colorant composition of the present invention include copper phthalocyanine pigments, slene pigments, and azo as long as the effects of the present invention are not impaired for the purpose of adjusting color development and the like. Known pigments such as quinacridone pigments, anthracinone pigments, dioxane pigments, indigo pigments, thioindigo pigments, perinone pigments, perylene pigments, isoindolinone pigments, and diketopyrrolopyrrole pigments. Organic pigments can be used.

<Water>
As the water used as the solvent in the composition of the present invention, any water such as tap water, purified water, distilled water and the like can be adopted. The amount of water in the composition of the present invention is preferably 60.0 to 90.0% by weight, more preferably 70.0 to 80.0% by weight. If it is less than 60.0% by weight, the viscosity may become too high and the brush stroke may deteriorate, and if it exceeds 90.0% by weight, the viscosity becomes too low and wrinkles occur on the calligraphy after writing. May be easier to do.

<Other additives>
Others, if necessary, polyhydric alcohols such as glycerin, propylene glycol, ethylene glycol, rust preventives (eg, benzotriazole, tolyltriazole, dicyclohexylammonium nitrate, etc.), antiseptic and antifungal agents (eg, benzoisothiazolin-based antiseptic). Antifungal agents, pentachlorophenol-based antiseptic antifungal agents, cresol-based antiseptic fungicides, etc.), surfactants, wetting agents, antifoaming agents, leveling agents, anti-aggregation agents, pH adjusters, pseudoplastic excipients, fragrances Conventional additives such as, etc. can be added.

<Manufacturing method>
In the method for producing an erasable colorant composition of the present invention, a carbon black dispersion and an aqueous resin solution may be prepared and mixed, or the carbon black and the resin may be added to water and stirred. You may.
Preferably, first, a polyvinyl alcohol-dissolved carbon black dispersion and a polyvinyl alcohol aqueous solution are prepared separately. Then, the dispersion and the aqueous solution are mixed to obtain the erasable colorant composition of the present invention.
A known disperser or stirrer can be used in the steps of preparing the dispersion and the aqueous solution and the step of mixing the dispersion and the aqueous solution. Specific examples thereof include a disperser such as a bead mill, a ball mill, a sand mill, a roll mill and a kneader, and a stirrer such as a turbo mixer.

(Manufacturing of carbon black dispersion)
Production of Base Formulation 1 (Printex85, PVA105) As shown in Table 1 below, 15.0% by weight of Printex85 (pH 9.5, particle size 16 nm) and polyvinyl alcohol (PVA105 (saponification)) were added to the total amount of carbon black dispersion. Degree 98.0-99.0 mol%, degree of polymerization 500, 4% by weight 20 ° C. 20 ° C. aqueous solution viscosity 5.2-6.0 mPa · s)) 15% by weight aqueous solution 50.0 % by weight, isopropyl alcohol 6.0 A carbon black (CB) dispersion prepared by dispersing water at a peripheral speed of 10 m / s for 20 minutes with a bead mill (Dynomill: manufactured by Simmal Enterprises) so that the weight% and water are 29.0% by weight. Manufactured.
The viscosity is a value measured according to the JIS standard K6726-1994 polyvinyl alcohol test method.

Production of Base Formulation 2 (Printex85, PVA205) Polyvinyl alcohol was PVA205 (saponification degree 86.5 to 89.0 mol%, degree of polymerization 500, viscosity of 4 wt% 20 ° C aqueous solution 4.6 to 5.4 mPa · s). A carbon black dispersion was produced in the same manner as in Base Formulation 1 (Printex85, PVA105) except for the above.

Production of Base Formulation 3 (Printex85, PVA403) Polyvinyl alcohol was used as PVA403 (saponification degree 78.5 to 81.5 mol%, degree of polymerization 300, viscosity of 4 wt% 20 ° C aqueous solution 2.8 to 3.3 mPa · s). A carbon black dispersion was produced in the same manner as in Base Formulation 1 (Printex85, PVA105) except for the above.

Production of Base Formulation 4 (Printex85, PVA505) Polyvinyl alcohol was PVA505 (saponification degree 72.5 to 74.5 mol%, degree of polymerization 500, viscosity of 4 wt% 20 ° C aqueous solution 4.2 to 5.0 mPa · s). A carbon black dispersion was produced in the same manner as in Base Formulation 1 (Printex85, PVA105) except for the above.

Production of Base Formulation 5 (SPECIAL BLACK 4A, PVA105) A carbon black dispersion was produced in the same manner as in Base Formulation 1 (Printex85, PVA105) except that the carbon black was SPECIAL BLACK 4A (pH 3, particle size 25 nm).

Production of Base Formulation 6 (SPECIAL BLACK 4A, PVA205) A carbon black dispersion was produced in the same manner as in Base Formulation 2 (Printex85, PVA205) except that the carbon black was SPECIAL BLACK 4A (pH 3, particle size 25 nm).

Production of Base Formulation 7 (SPECIAL BLACK 4A, PVA505) A carbon black dispersion was produced in the same manner as in Base Formulation 4 (Printex85, PVA505) except that the carbon black was SPECIAL BLACK 4A (pH 3, particle size 25 nm).

(Washing erasability)
-Preparation of test sample Using a water-free drawing brush (flat brush No. 4), apply the prepared erasable coloring material composition to each test cloth of cotton broad (bleached), polyester taffeta, and silk habutae. It was left at room temperature until it was dry to the touch.

-Washing with powder detergent The dried test sample was placed in a 0.4 wt% 20 ° C aqueous solution (pH 10) of a weak alkaline synthetic powder detergent for 2 hours, and then washed by hand for 3 minutes.
Then, using a washing machine, it was washed in a 0.1 wt% 20 ° C. aqueous solution (pH 10) of a weak alkaline synthetic powder detergent for 15 minutes, and then washed with water for 15 minutes.

-Washing with liquid detergent The dried test sample was placed in a 0.2 wt% 20 ° C aqueous solution (pH 7.4) of a neutral liquid detergent for 2 hours, and then washed by hand for 3 minutes.
Then, using a washing machine, it was washed in a 0.03 wt% 20 ° C. aqueous solution (pH 7.4) of a neutral liquid detergent for 15 minutes, and then washed with water for 15 minutes.

ΔE * was measured between the test sample after washing and the cloth of the same material that was washed in the same manner as the test sample and was not coated with the erasable colorant composition, and the wash erasability was determined according to the following criteria. It was judged.

(Handwriting)
The test was conducted according to the test method of "Japan Writing Tools Industry Association Brush Pen".
I handwritten the letters "Ei" on a piece of paper with a calligraphy brush, and checked if I could stop, splash, and shave. An example of ◯ is shown in FIG. 1, an example of Δ is shown in FIG. 2, and an example of × is shown in FIG.
◯: Stop, splash, and flutter can be done smoothly.
△: You can stop, splash, and flutter, but the brush strokes are a little slow. (Refer to the payment part on the left and the splash part below)
×: Stop, splash, and flutter are not enough. (Refer to the payment part on the left and the splash part below)

(Returnability)
A calligraphy brush was impregnated with an erasable colorant composition, and in that state, 20 ° C. 65% R. It was dried in H for 1 week. The entire brush hair that has hardened after drying is immersed in the erasable colorant composition for 3 minutes.
After the immersion, the brush was smoothed in the erasable coloring material composition, and the looseness of the hair was confirmed.
In addition, one letter of the Chinese numeral "1" was written on the calligraphy (Otaka Paper Co., Ltd. "Fuji Tenryu" Japan Thick Mouth) without adding the erasable coloring material composition, and the degree of faintness of the handwriting was confirmed.
○: Can be written without being loosened and blurred.
Δ: It is hard to loosen, but it can be written without fading.
×: It is hard to loosen and cannot be written faintly.

(Hand washability)
Lightly wipe the dirt off your palm with alcohol.
With a calligraphy brush containing an erasable colorant composition, a circle with a diameter of about 2 cm was drawn on the palm and completely dried at room temperature.
After confirming that it was dry to the touch, the drawn circular portion was rubbed with the pad of the finger while being exposed to running water for 1 minute, and it was confirmed to what extent the erasable colorant composition had fallen. An example of ◯ is shown in FIG. 4, an example of Δ is shown in FIG. 5, and an example of × is shown in FIG.
◯: It fell completely. (See center of palm)
Δ: Almost fell. (See center of palm)
X: Although it fell off, more than half of the dirt remained. (See center of palm)

As shown in Table 2 below, each base formulation was mixed with a 15% (% by weight) aqueous solution of PVA to obtain an erasable colorant composition of Examples and Comparative Examples.
Evaluation was performed from each of the above viewpoints using these erasable colorant compositions, products of other companies containing dyes, and products of other companies containing raw materials. The results are shown in Table 2.

According to Table 2, Examples 1 to 10 are examples according to the present invention, and sufficient erasability could be exhibited by a neutral liquid detergent.
On the other hand, Comparative Examples 1 to 12 and the commercially available products containing pigments could not be sufficiently erased even when washed with a liquid detergent neutral to cotton broadcloth. In particular, in Comparative Examples 1 and 2, since the degree of saponification of PVA was high, the writing performance and the rewriting property were poor. According to Comparative Examples 3, 4, 9 to 12, the hand-washing property of the adhered composition was insufficient.

Claims (3)

Contains polyvinyl alcohol, carbon black, and water,
The polyvinyl alcohol contains polyvinyl alcohol having a saponification degree of 86.5 to 89.0 mol% and polyvinyl alcohol having a saponification degree of 98.0 to 99.0 mol%.
An erasable colorant composition containing 1.5 to 20.0% by weight of polyvinyl alcohol having a saponification degree of 70.0 to 95.0 mol% with respect to the entire erasable colorant composition. The erasable coloring material composition according to claim 1, wherein the polyvinyl alcohol has a viscosity of 30 mPa · s or less when made into an aqueous solution containing only polyvinyl alcohol in an amount of 4% by weight. The scavenging colorant composition according to claim 1 or 2, wherein the polyvinyl alcohol has a degree of polymerization of 300 to 1000.

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