JP2916489B2 - Marking ink composition for writing board - Google Patents

Description

The present invention relates to a marking ink composition for a writing board,
In particular, it is possible to write on a non-permeable writing surface, that is, a writing plate such as a polypropylene plate, a melamine baked painted plate, an enamel plate, a glass plate, a fluororesin film, etc. The present invention relates to a marking ink composition that can be easily erased by gently rubbing with a soft paper.

(Prior art) Conventionally, attempts have been made to add various fatty acid ester liquid paraffins, plasticizers or surfactants to a marking ink composition comprising a colorant / resin and a solvent, and to improve a method of erasing handwriting by various methods. It has been done.

(Problems to be Solved by the Invention) The conventional marking inks described above do not particularly have sufficient erasing ability of handwriting over time, and handwriting that has passed for a long time after writing has to be rubbed several times with a dry cloth or the like. Has the problem that it cannot be erased.

(Means for Solving the Problems) In view of the above-mentioned problems, the present invention aims to improve the initial erasability and particularly the erasability over time. That is, the present invention provides a pigment and polyvinyl alcohol. (1) pentaerythritol-tetrafatty acid ester derivative and (2) ester of aliphatic monocarboxylic acid having 8 or more carbon atoms and aliphatic monohydric alcohol having 8 or more carbon atoms as butyral resin and lower aliphatic alcohol as additives. 3) It has been found that the combined use of a phosphoric acid ester of polyoxyethylene alkyl ether or a phosphoric acid ester of polyoxyethylene alkyl phenyl ether significantly improves the day-to-day erasability, thereby completing the present invention.

(Action) It is presumed why the marking ink composition of the present invention is excellent in day erasability.

The handwriting by the marking ink composition of the present invention shows that when the solvent evaporates, the pentaerythritol-tetrafatty acid ester derivative and the polyoxyethylene alkyl ether phosphate or the phosphate of polyoxyethylene alkyl phenyl ether plasticize the butyral resin for a long time. The ester of aliphatic monocarboxylic acid having 8 or more carbon atoms and aliphatic monohydric alcohol having 8 or more carbon atoms is incompatible with butyral resin and exists at the interface between the writing board and the resin film. Further, it is considered that a part of the above-mentioned phosphate ester-based surfactant is also present at the interface and facilitates peeling and erasing when rubbed with a cloth or the like.

Any one of the three additives of the above-mentioned phosphate ester surfactant, pentaerythritol-tetrafatty acid ester, ester of aliphatic monocarboxylic acid having 8 or more carbon atoms and aliphatic monohydric alcohol having 8 or more carbon atoms can be used. If it is missing, the erasability or the erasability over time will deteriorate, and it is considered that the three additives contribute to the improvement of the erasability by some synergistic effect.

(Constitution of the Invention) Each component of the present invention will be described below.

Pigments can be used as long as they are used as a colorant and can be used as long as they are stably dispersed as fine particles in the ink composition. It is preferable from the viewpoint of stability over time and workability. The amount of the pigment used is 1 to 10%, preferably 2 to 6%, based on the total amount of the ink.

The resin is used to give the ink a film-forming ability and to impart the viscosity of the ink to the surface to be written and the dispersion stability of the pigment. In order to lower the value, a resin having a low degree of polymerization, for example, butyral 2000-L (manufactured by Denki Kagaku Kogyo) is preferred. The amount used is 1 to 10 based on the total amount of ink.
% By weight, preferably 2 to 6%. In the case of the processed pigment, the resin in the processed pigment can be substituted.

The lower alcohol is used as a solvent, and may be one or two of ethanol, normal propanol, isopropanol, normanbutanol, secondary butanol and the like.
More than one kind can be used, and the mixing ratio of various alcohols is determined in consideration of the miscibility with the additives used. These are used in an amount of 65 to 90%, preferably 72 to 85% based on the total amount of the ink.
%.

Pentaerythritol represented by the following general formula (I)
Tetra fatty acid ester derivatives R _{1 to} R ₄ represent an alkyl group having 3 to 21 carbon atoms.R _{1 to} R ₄ may be the same or different. Compatible with a butyral resin, and when written, the handwriting is softened for a long time and the handwriting is It imparts a property that can be easily erased by scratching, and is a tetraester of pentaerythritol with caproic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, behenic acid or oleic acid, and more specifically. Pentalan 408 (pentaerythritol tetraoctanoate Nikko Chemical) Unistar HP3106M [pentaerythritol tetra (capron, capryl, caprin) acid ester Nippon Yushi] Unistar H4812 [pentaerythritol tetra (caprylic caprin, lauric acid) ester Japan Fats and oils] UNISTAR H407R (pentaerythritol tetraoctanoic acid Ester Japan Oil & Fat) Unistar H481R (pentaerythritol tetrastearate Japan Oil & Fat). Its use amount is 1 to 10%, preferably 2 to 10%.
~ 6%.

Fatty acid esters, which are esters of monocarboxylic acids having 8 or more carbon atoms and aliphatic monohydric alcohols having 8 or more carbon atoms, are used to improve the erasability of handwriting,
It is present at the interface between the plate of the handwriting written on the writing plate and the coating film and is easily peeled and erased from the plate by rubbing with a cloth or the like. Specific examples thereof include 2-earhexyl palmitate, octyldodecyl myristate, 2-ethylhexyl stearate, octyl oleate, ralyl oleate, and octyldodecyl oleate. These can be used alone or in combination of two or more, and the amount used is preferably 0.5 to 10% based on the total amount of the ink.
3 to 8%.

Phosphate ester of polyoxyethylene alkyl ether, phosphate ester surfactant of polyoxyethylene nonyl phenyl ether is compatible with polyvinyl butyral resin, softens butyral resin, and added to ink composition for writing board, When writing on a writing board, a part of the total surfactant moves around the interface between the handwriting and the writing board, and improves the erasability by rubbing with a cloth. It also acts as a pigment dispersant and improves storage stability. Specifically, Nikkor DD
P-2, DDP-4, and DNPP-4 (hereinafter Nikko Chemical Co., Ltd.) Plysurf A207H, A208S, and A212S (all manufactured by Daiichi Kogyo Seiyaku Co., Ltd.). Its usage is
It is 1 to 8%, preferably 2 to 4%.

The ink composition of the present invention is produced as follows.
The processed pigment is put into a ball mill, and a lower alcohol is added thereto to make the processed pigment content 20%, and the mixture is ground overnight to obtain a uniform pigment dispersion. The various additives and the rest of the lower alcohol are added to the tank and dissolved by stirring to form a uniform solution. The pigment dispersion is added to this and stirred to form an ink.

However, the above-mentioned production method is merely an example, and the order of addition of each component is not limited at all, as long as a uniform ink composition can be obtained.

(Examples) Hereinafter, the present invention will be described in more detail with reference to Examples.
The composition in Table 1 indicates "% by weight".

The processed pigments of Examples and Comparative Examples shown in Table 1 below were first prepared as a pigment dispersion of a lower alcohol liquid having a processed pigment content of 20% by a ball mill, and then an additive and the remaining lower alcohol were added to a tank and stirred. The pigment ink dispersion was added to the solution to obtain a marking ink composition which was uniformly dispersed. However, lower alcohols are indicated as total amounts in the table.

<Supplementary explanation of Table-1> (1) Fuji AS Black810: manufactured by Fuji Dye Co., Ltd.
Pigment: carbon black (50%), resin: polyvinyl butyral resin (50%) (2) Fuji AS Blue650: manufactured by Fuji Dye Co., Ltd., processed pigment,
Pigment: phthalocyanine blue (50%), resin: polyvinyl butyral resin (50%) (3) Fuji AS Red575: manufactured by Fuji Dye Co., Ltd., processed pigment, pigment: azo pigment (50%), resin: polyvinyl butyral Resin (50%) (4) Fuji AS Green710: manufactured by Fuji Dye Co., Ltd.
Pigment: phthalocyanine green (50%), resin: polyvinyl butyral resin (50%) (5) Nikkor DDP-2: polyoxyethylene alkyl ether phosphate ester manufactured by Nikko Chemicals Co., Ltd. (6) Nikkor DNPP-4: Nikko Polyoxyethylene alkyl phenyl ether phosphate ester manufactured by Chemicals Co., Ltd. (Effects of the Invention) The marking compositions obtained in Examples 1 to 4 and Comparative Examples 1 to 3 were written on a polypropylene plate and initially erased. Table 2 shows the results of tests on the properties and erasing properties over time (one month after writing and standing at room temperature).

In the table. ◎: extremely good, ○: good, ×: bad * 1-Initial erasability test: A spiral wire of a certain size was drawn on a polypropylene plate, dried, and the handwriting was loaded with a 50 g load using a dry cloth. And the state of erasure of the handwriting was visually determined.

* 2-Day erasure test: A spiral wire of a certain size is drawn on a polypropylene plate, left at room temperature for one month, and a 50 g load is applied on the handwriting using a dry cloth.
And the erased state of the handwriting was visually determined.

As described above, the marking ink composition of the present invention can be written on a writing board having a smooth and impervious surface, and can be easily erased by gently rubbing the handwriting with a dry cloth or the like, and erased after a lapse of time. It is also excellent.

Claims (1)

(57) [Claims] 1. An erasable marking ink comprising a pigment, a polyvinyl butyral resin, a lower aliphatic alcohol and an additive, wherein the additive is (1) a pentaerythritol-tetrafatty acid ester represented by the following general formula (I): A derivative, (2) an ester of an aliphatic monocarboxylic acid having 8 or more carbon atoms and an aliphatic monohydric alcohol having 8 or more carbon atoms, and (3) a phosphoric acid ester of polyoxyethylene alkyl ether or
A marking ink composition for a writing board, comprising at least a polyoxyethylene alkylphenyl ether phosphate. R _{1 to} R ₄ represent an alkyl group having 3 to 21 carbon atoms. R _{1 to} R ₄ may be the same or different.