JPH0753906A - Water-base erasable ink composition for marking pen - Google Patents

Abstract

PURPOSE:To provide the compsn. which provides written lines of which only the part rubbed with dry cloth, etc., is easily removed from the surface of a writing board regardless of the material of the board, i.e., regardless of whether the board is a white board, a plastic board, or a coated board. CONSTITUTION:The compsn. comprises water as the solvent, a colorant dissolved or dispersed in water, a polyvinyl acetal resin as the film-forming agent, a water-base emulsion of a liq. aliph. carboxylic ester hardly volatile at normal temp. as the release agent, and at least either a polyoxythylene polyoxypropylene block copolymer or a lanolin deriv. as the release assistant.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water-based erasable marking pen ink composition, and more particularly to a water-based, non-absorptive or non-permeable writing surface, typically a so-called white board. The present invention relates to a water-based marking pen ink composition which is excellent in erasability of the handwriting written in.

[0002]

2. Description of the Related Art Conventionally, the surface of a non-absorbent or impermeable writing surface made of enamel or resin is lightly rubbed with a dry cloth or soft paper to wipe it off from the writing surface. Various erasable marking pen ink compositions for erasing handwriting are known. Such a conventional erasable marking pen ink composition generally contains an organic solvent, a pigment, a resin and an additive called a release agent. For example, Japanese Patent Publication No. 62-9149 discloses that
There is described an erasable marking pen ink composition obtained by dissolving a substance selected from a surfactant and a saturated aliphatic carboxylic acid triglyceride in an organic solvent together with an aliphatic dibasic acid ester and an aliphatic monobasic acid ester.

However, in the conventional erasable marking pen ink composition, as described above, ketones and alcohols are used as the solvent. Particularly, among these solvents, ketones are highly toxic, and among alcohols, methanol is highly toxic and has a bad odor. On the other hand, ethanol is relatively less toxic,
Raw material cost will be increased.

Therefore, for example, JP-A-60-17947
As described in JP-A No. 8 and JP-A-60-219273, a resin emulsion such as a polyvinyl acetate resin as a release agent is dissolved in water together with a dye or pigment as a colorant and a predetermined surfactant. Aqueous erasable marking pen ink compositions containing the same have been proposed. However, since such a water-based ink composition uses a resin emulsion as a release agent, as with so-called strippable paint, in handwriting on a non-absorbing surface, after drying,
The resin emulsion forms a continuous film on the writing surface, and accordingly, the handwriting is to be peeled off in a continuous film shape, and the handwriting is easily rubbed from the writing surface as long as the handwriting is rubbed lightly. It is difficult to say that it does not peel off and has excellent erasability.

Accordingly, various improvements have recently been proposed for aqueous erasable marking pen ink compositions. For example, in JP-A-64-11174 and JP-A-1-188576, an aqueous erasability using a water-soluble polyvinyl alcohol as a resin component for forming a film and a silicone-based surfactant as a release agent is disclosed. Ink compositions have been proposed. In addition, JP-A-1
JP-A-252681 discloses, as a resin component for forming a film, a water-soluble resin or a resin which is originally water-insoluble but is water-solubilized by salt formation with a base, for example,
In addition to using a styrene-maleic anhydride resin and an emulsion of an aliphatic carboxylic acid ester, a higher hydrocarbon or a higher alcohol which is liquid at room temperature as a release agent, an aqueous erasable marking pen ink composition has been proposed.

Further, in JP-A-2-117975, a polyvinyl acetal resin is used as a resin component,
An aqueous erasable marking pen ink composition using a polyalkylene glycol ether ester compound as a release agent has been proposed.

[0007]

However, the conventionally known aqueous erasable marking pen ink composition as described above is still insufficient in erasability and is not practically satisfactory. That is, the erasability of the handwriting deteriorates over time, or depending on the environmental atmosphere, especially humidity conditions,
The erasability is inferior, and the erasability is inferior in the case of a white plate material, particularly a resin plate or a coated plate.

Then, the inventors of the present invention have conducted extensive studies to solve the above-mentioned problems in the conventional water-based erasable marking pen ink composition, and as a result, as a resin component for forming a film, a water-soluble polyvinyl acetal resin was used. Used,
Further, as a release agent for handwriting, an aqueous emulsion of a non-volatile aliphatic carboxylic acid ester which is liquid at room temperature is used, and in order to assist the action of this release agent, a polyoxyethylene polyoxypropylene block is used as a release assistant. Combined use of a copolymer or a lanolin derivative, particularly preferably, by using both of these peeling aids at the same time, not only the handwriting part rubbed with a dry cloth etc. can be easily peeled from the writing surface, Further, the present invention has been completed by finding that a white plate made of a resin can have excellent erasability in writing, regardless of the material of the white plate.

[0009]

The water-based erasable marking pen ink composition according to the present invention comprises (a) water as a solvent,
(b) a colorant dissolved or dispersed in water, (c) a polyvinyl acetal resin as a film-forming agent, (d) a release agent, an aqueous emulsion of a liquid aliphatic carboxylic acid ester which is hardly volatile at room temperature, And (e) at least one selected from polyoxyethylene-polyoxypropylene block copolymers and lanolin derivatives as a release aid.

In the aqueous erasable marking pen ink composition according to the present invention, water is used as a solvent.
The amount of water in the ink composition is usually 50 to 90% by weight, preferably 60 to 80% by weight.

In the marking pen ink composition according to the present invention, a pigment is preferably used as the colorant. Examples of the pigment include inorganic pigments such as carbon black, titanium oxide, and iron oxide, phthalocyanine-based such as copper phthalocyanine blue, azo-based, quinacridone-based, anthraquinone-based, dioxane-based, indigo-based, thioindigo-based, perinone-based, perylene-based Any of indolenone-based and azo-azomethine-based organic pigments and the like may be used depending on the characteristics and use of the ink composition.

By the way, a dispersion prepared by dispersing various pigments in water is already on the market, and in the present invention as well,
Such commercial products can be preferably used. Since various resin dispersants, surfactants and the like may be blended in the pigment dispersion as a pigment dispersant, such resins, surfactants and the like may be used in the ink composition of the present invention. May be contained. Pigment dispersants are known per se, and generally 1 to 3 parts by weight of pigment.
It is used in an amount of 00 parts by weight, preferably 5 to 100 parts by weight.

When preparing the aqueous erasable ink composition according to the present invention, the pigment may be previously made into an aqueous dispersion by using a resin dispersant, and this may be mixed with other components to obtain an ink composition. . As described below, the water-soluble polyvinyl acetal resin used as the film forming agent in the present invention can be preferably used as this resin dispersant.

In the present invention, a dye can also be used as a colorant. In this case, a water-soluble dye is preferably used as the dye. In the present invention, the colorant as described above is usually contained in the ink composition in an amount of 0.5 to 0.5.
It is contained in the range of 20% by weight, preferably in the range of 1 to 15% by weight. When the colorant is contained in an excessive amount, the viscosity of the ink composition is too high, so that the flow of the ink composition is deteriorated, the writing property is deteriorated, and the erasability is also deteriorated. On the other hand, if the colorant content is too low,
The concentration of handwriting is so low that a practical marking pen ink composition cannot be obtained.

The ink composition according to the present invention has a coating or layer on the non-absorption surface, which is written on the non-absorption surface, and has a coating or a layer made of a resin containing the above-mentioned colorant on the handwriting. A water-soluble polyvinyl acetal resin is contained so that it can be separated from the layer of the release agent described later. Generally, a polyvinyl acetal resin can be obtained by reacting polyvinyl alcohol with an aliphatic aldehyde, but in such an acetalization reaction, polyvinyl alcohol cannot be completely acetalized,
In addition, some acetyl groups remain at the stage of producing polyvinyl alcohol by saponification. Therefore, in general, the polyvinyl acetal resin has the following formula (I):

[0016]

[Chemical 1]

(In the formula, R represents hydrogen or an alkyl group having 1 to 3 carbon atoms.) And has an acetal structure and a considerable amount of hydroxyl group and acetyl group in the molecule.

The polyvinyl acetal resin suitable for use in the present invention is a polyvinyl acetal resin in which R is hydrogen or an alkyl group having 1 to 3 carbon atoms in the above formula,
That is, polyvinyl formal resin, (narrowly defined) polyvinyl acetal resin, polyvinyl butyral resin, etc., having an acetalization degree in the range of 5 to 40 mol% and a pH of
Of 7 ± 2 and solid content of 18 ± 4% have a viscosity of 4000
It is in the range of ± 3000 centipoise. In the present invention, a polyvinyl acetal resin or a polyvinyl butyral resin in a narrow sense or a mixture thereof is particularly preferably used. As such a water-soluble polyvinyl acetal resin, a commercially available product can be obtained, and in the present invention, such a commercially available product can be preferably used.

In the present invention, the water-soluble polyvinyl acetal resin is contained in the ink composition in an amount of 0.1 to 15% by weight, preferably 0.2 to 10% by weight. When the blending amount of the water-soluble polyvinyl acetal resin in the ink composition exceeds 15% by weight, the viscosity of the ink composition becomes excessively high, the writability deteriorates, and the erasability also decreases. However, when the content is less than 0.1% by weight, the erasability of handwriting is inferior.

Next, in the ink composition according to the present invention, a sparingly volatile aliphatic carboxylic acid ester which is liquid at room temperature is used as a release agent for handwriting. The aliphatic carboxylic acid ester as such a release agent is contained in the aqueous emulsion state in the ink composition according to the present invention. As the above-mentioned aliphatic carboxylic acid ester, the ester is preferably a monobasic acid ester, a dibasic acid diester, or a trihydric alcohol, particularly a mono-, di-, or triester of glycerin.

Particularly preferred specific examples include monobasic acid esters, particularly higher fatty acid esters such as propyl myristate, butyl palmitate, butyl stearate,
Octyl stearate, butyl isostearate, dialkyl aliphatic dibasic acid ester dioctyl dodecanedioate, dipropyl adipate, dioctyl sebacate, dioctyl azelate, and other trihydric alcohol triesters, natural or synthetic fatty acid triglycerides and triglycerides. Methylolpropane triisostearate and the like can be mentioned. These are used alone or as a mixture of two or more kinds.

In the ink composition according to the present invention, the aliphatic carboxylic acid ester as a release agent is contained in the ink composition in an amount of 1 to 20% by weight, preferably 2 to 15% by weight. In the ink composition, when the blending amount of the aliphatic carboxylic acid ester is less than 1% by weight, sufficient handwriting erasability cannot be obtained. On the other hand, when the blending amount exceeds 20% by weight, it is excessively blended. , The handwriting grows and the writing surface is soiled, and the erasability of the handwriting deteriorates.

In the ink composition according to the present invention, a polyoxyethylene polyoxypropylene block is used as a release aid together with the above aliphatic carboxylic acid ester as a release agent in order to further improve the effect of the release agent. At least one selected from a polymer and a lanolin derivative is used in combination.

First, the polyoxyethylene-polyoxypropylene block copolymer used in the present invention is a water-soluble polymer and is a kind of surfactant, and the amount of oxyethylene in the molecule is usually 40% by weight or less. Is. Further, the polyoxyethylene polyoxypropylene block copolymer used in the present invention has a molecular weight of 700.
It is preferably in the range of ˜3000.

Such a polyoxyethylene-polyoxypropylene block copolymer has, for example, the following formula (II):

[0026]

[Chemical 2]

(In the formulae, m, n and p are numbers such that the molecular weight of the copolymer is in the range of 700 to 3000.)
It is represented by.

Various commercially available products can be used as the polyoxyethylene-polyoxypropylene block copolymer. Examples of such commercially available products include Newpole PE-61, PE-62, PE-71 (all manufactured by Sanyo Chemical Industry Co., Ltd.), Pluronic L-31,
L-44, L-61, L-64, F-68, P-84,
F-83, L-101 (both Asahi Denka Co., Ltd.
Manufactured), Epan 420, 720 (all manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.), Emulgen PP-150, PP-230.
(All manufactured by Kao Corporation), Pronon 102, 201
(All manufactured by NOF CORPORATION), Actinol P-30
35 (Matsumoto Yushi-Seiyaku Co., Ltd.), Lionol PL-3
2, PL-42, PL-712 (all manufactured by Lion Corp.) and the like can be mentioned.

The polyoxyethylene polyoxypropylene block copolymer is useful for increasing the erasability of the ink composition as a whole. According to the present invention, such a polyoxyethylene polyoxypropylene block copolymer is contained in the ink composition in the range of 0.1 to 5% by weight. If the blending amount is too small, the ink composition obtained will be inferior in erasability. On the other hand, if the blending amount is too large, the handwriting will extend when the handwriting is erased, and the white plate will be stained. In particular, according to the present invention, the polyoxyethylene polyoxypropylene block copolymer is preferably contained in the range of 0.2 to 3% by weight based on the ink composition.

In the ink composition according to the present invention, the lanolin derivative used as a peeling aid is, for example, lanolin alcohol derived from purified lanolin, alkoxylated lanolin, or the like, or an alkoxy obtained by alkoxylating lanolin alcohol. Lanolin alcohol, lanolin alcohol fatty acid ester obtained by esterifying lanolin alcohol with a fatty acid, acetylated lanolin alcohol obtained by acetylating lanolin alcohol, hydrogenated lanolin alcohol obtained by hydrogenating lanolin alcohol, solvent fractionation of lanolin alcohol, Cholesterol or isocholesterol, and alkoxylated cholesterol or alkoxylated isocholesterol obtained by alkoxylating these are particularly preferably used. In the above, alkoxylation means ethoxylation by addition of ethylene oxide.

Particularly, ethoxylated cholesterol is preferably used in the present invention. This ethoxylated cholesterol is usually dissolved in a mixed solvent of water and ethanol and mixed into the ink composition.

Commercially available products can be used as these lanolin derivatives. Examples of such commercially available products include Bellpol A-2 which is an ethoxylated lanolin alcohol.
0, ethoxylated cholesterol bellpol C-2
4, ethoxylated lanolin Bellpol L-19, Bellpol L-30, Bellpol L-75, etc. (all are
Yoshikawa Essential Oil Co., Ltd. etc. can be mentioned. The lanolin derivative imparts excellent erasability to a white plate made of a resin such as a melamine resin or a polyester resin in the ink composition.

The ink composition according to the present invention contains the lanolin derivative in an amount of 0.01 to 5% by weight, preferably 0.1 to 2%.
It is contained in the range of% by weight. When the amount of the ink composition is too much over 5% by weight based on the ink composition, the viscosity of the ink composition becomes too high, resulting in poor writability.
If the amount is less than wt%, the ink composition cannot have sufficient erasability.

Particularly, in the present invention, as the release agent,
With the use of a liquid volatile aliphatic carboxylic acid ester that is liquid at room temperature as described above, as a release aid, by simultaneously using both the polyoxyethylene polyoxypropylene block copolymer and the lanolin derivative described above,
It is possible to obtain an aqueous erasable ink composition having excellent erasability regardless of the passage of time and the environment and the material of the white board.

In the present invention, if necessary, an aqueous emulsion of a refractory higher hydrocarbon that is liquid at room temperature or a refractory higher alcohol that is liquid at room temperature is used as a release agent of the aliphatic carboxylic acid ester. You may use together with aqueous emulsion. As the higher hydrocarbon, usually,
What is called fluid paraffin, squalane, or the like is preferably used, but it may be partially oxidized, for example, polyethylene oxide wax. Also,
The higher alcohol is not particularly limited, but for example, hexyl alcohol, octyl alcohol, lauryl alcohol and the like are preferably used.

The above-mentioned aliphatic carboxylic acid ester and the aqueous emulsion of higher hydrocarbon or higher alcohol can be prepared by a usual emulsification method.
Moreover, a commercial item can also be used. Thus, when a higher hydrocarbon or higher alcohol is used together with the above aliphatic carboxylic acid ester as the release agent, the total amount of the compound is 1 to 20% by weight, preferably 2% by weight in the ink composition. Is in the range of 15% by weight.

In the ink composition according to the present invention, a water-soluble polyhydric alcohol may be used in combination as a further release aid in order to enhance the effect of the release agent. Examples of such polyhydric alcohols include ethylene glycol, diethylene glycol, triethylene glycol,
In addition to (poly) alkylene glycols such as propylene glycol, dipropylene glycol, tripropylene glycol, polyethylene glycol having a molecular weight of about 200 to 600 and polypropylene glycol having a molecular weight of 1000 to 3000, glycerin, trimethylolpropane and the like can be mentioned. Such a water-soluble polyhydric alcohol is blended in the ink composition in a range of 20% by weight or less, preferably 10% by weight or less. If the amount of the ink composition is too much over 20% by weight, the viscosity of the ink composition becomes excessively high and the writability is deteriorated, which is not preferable.

In the ink composition according to the present invention, in addition to the above-mentioned polyvinyl acetal resin, a conventionally known resin having a film-forming property at room temperature can be used as a resin component as a film-forming auxiliary. . In the present invention, as the room temperature film-forming resin, in particular, (1) water-insoluble resin, for example, polyvinyl acetate, vinyl acetate copolymer, alkyd resin, acrylic resin, urethane resin or other emulsion or hydrosol, or ( 2) Resin that is originally water-insoluble but is water-solubilized by salt formation, for example, vinyl acetate copolymer, acrylic resin, styrene-maleic anhydride resin, maleated oil, maleated polybutadiene, malein Alkyd resin, maleated petroleum resin, maleated rosin ester resin, alkyd resin, urethane resin, etc., which is originally water-insoluble, but is water-solubilized by salt formation, or (3) A resin that is originally water-soluble is preferably used.

As the comonomer in the emulsion or hydrosol or the water-solubilized vinyl acetate copolymer, vinyl ester compounds other than vinyl acetate, such as vinyl propionate and vinyl versatate, and unsaturated carboxylic acids, such as vinyl acetate, can be used. , Acrylic acid, methacrylic acid, maleic acid, maleic anhydride, fumaric acid, itaconic acid, crotonic acid, citraconic acid, etc., or vinyl hydrocarbons such as ethylene, propylene, styrene, α-methylstyrene, etc. . These may be mixed and used as a comonomer. Furthermore, in addition to the above, esters of the above unsaturated carboxylic acids such as methyl acrylate, ethyl acrylate, methyl methacrylate, dimethyl maleate and the like can be used as a comonomer. Also,
The vinyl acetate copolymer may be a graft copolymer to polyvinyl acetate.

As a specific example of a particularly preferable vinyl acetate copolymer, for example, a vinyl acetate-acrylic acid copolymer,
Vinyl acetate-methacrylic acid copolymer, vinyl acetate-styrene-acrylic acid copolymer, vinyl acetate-styrene-maleic anhydride copolymer, vinyl acetate-acrylic acid-methyl acrylate copolymer, vinyl acetate-methacrylic acid -Methyl acrylate copolymer, vinyl acetate-acrylic acid-ethyl acrylate copolymer, vinyl acetate-methacrylic acid-
Examples thereof include a methyl methacrylate copolymer and a vinyl acetate-maleic anhydride copolymer.

Polyvinyl acetate and emulsions and hydrosols of the above vinyl acetate copolymers can be easily obtained as commercial products. Furthermore, emulsions and hydrosols of alkyd resins and urethane resins can be easily obtained as commercial products. Also, originally,
A resin that is water-insoluble but is water-solubilized by salt formation, etc. is a resin that is originally water-insoluble and is water-solubilized by salt formation with an inorganic or organic base. Examples thereof include alkali metal salts such as potassium and potassium, organic salts such as ammonium salts and organic amine salts.
A variety of such water-solubilized resins can be obtained as commercial products.

For example, the water-solubilized alkyd resin is
An alkyd resin having a free carboxyl group obtained from an excess amount of a polybasic acid and a polyhydric alcohol is neutralized and salted with an alkali metal base, an ammonium base, an organic amine, or the like, which is solubilized in water. These can be obtained as commercial products. For example, a water-solubilized urethane resin has, for example, a carboxyl group in the polymer main chain, and the carboxyl group is neutralized with an alkali metal base, an ammonium base, an organic amine or the like to form a water-solubilized urethane resin. These are also available as commercial products.

As the water-soluble resin, polyvinylpyrrolidone, a polymerization degree of 100 to 3000,
A water-soluble synthetic resin such as polyvinyl alcohol having a saponification degree of 50 mol% or more can be preferably used. But,
Natural water-soluble resins such as gum arabic and serratsk can also be used. The above resin is contained in the ink composition according to the present invention in a resin content of 0.1 to 15% by weight, preferably 0.3 to 10% by weight. When the resin is contained in an excessive amount, the viscosity of the ink composition is too high, so that the writability is poor and the erasability is also reduced. On the other hand, if the resin content is too low, the erasability of the handwriting will be poor.

Among the various room-temperature film-forming resins described above, in the present invention, emulsions and hydrosols of water-insoluble resins, or resins that are originally water-insoluble but are water-solubilized by salt formation or the like. Is preferably used. According to the ink composition containing such a room temperature film-forming resin,
As will be described later, when written, since such a resin contains a coloring agent together with the above-mentioned polyvinyl acetal resin and forms a film as a carrier for the coloring agent, the handwriting is excellent in water resistance,
Furthermore, it has stable erasability regardless of temperature and humidity conditions.

Further, the ink composition according to the present invention may contain various surfactants as a further peeling aid together with the above-mentioned peeling aid. As such a surfactant, any of anion, nonion, cation, and amphoteric can be used. However, in particular, nonionic surfactants such as carboxylic acid having a polyoxyethylene chain, sulfonic acid type, sulfuric acid ester type, phosphoric acid ester type and the like, anionic surfactants, amphoteric surfactants of alkyl betaine type, fluorine type Surfactants and the like are preferably used. Such a surfactant is usually contained in the ink composition in an amount of 10% by weight or less, preferably 0.2 to 5% by weight. When blended excessively, the erasability of handwriting is reduced.

The handwriting with the ink composition according to the present invention on the non-absorbent or non-permeable writing surface is such that the polyvinyl acetal, which is the above-mentioned film-forming agent, is formed when the water is evaporated, that is, when the handwriting is dried. While the resin and the resin component as a film forming aid contains a colorant, a film is formed, while
The emulsion of the aliphatic carboxylic acid ester as the release agent or the emulsion of the mixture of the aliphatic carboxylic acid ester and the higher hydrocarbon or higher alcohol is destroyed, and a continuous oily layer composed of the aliphatic carboxylic acid ester or the mixture thereof is not formed. Since it is formed so as to be interposed between the absorbent writing surface and the resin film, the handwriting has erasability.

Here, such a surfactant has an effect of assisting the separation of the oil layer and the resin film containing the pigment in handwriting during writing. However, the surfactant also enhances the leveling property at the time of writing, eliminates uneven distribution of the release agent emulsion in the handwriting before drying on the writing surface, and imparts uniform erasability after the handwriting is dried. Have.

Furthermore, the ink composition according to the present invention, as a drying accelerator for improving the dryness of handwriting, is usually 15% by weight or less based on the ink composition, as long as it does not destroy the emulsion contained in the ink composition. The lower aliphatic alcohol may be contained in an amount of preferably 1 to 10% by weight. In particular, ethanol, propanol or butanol is preferably used.

In addition to the above, the ink composition may be any of those usually added to the water-based ink composition, if necessary.
It may contain a pH adjuster, an antiseptic, an antiseptic and the like.

[0050]

The water-based erasable marking pen ink composition according to the present invention contains water as a solvent, a water-soluble polyvinyl acetal resin as a resin having a film-forming property at room temperature, and a liquid at room temperature as a release agent. And a sparingly volatile aliphatic carboxylic acid ester, and a polyoxyethylene-polyoxypropylene block copolymer or a lanolin derivative (particularly ethoxylated cholesterol) or an aqueous solution containing them together as a release aid. Since it is the ink composition of the above, there is almost no problem of toxicity, odor, and irritating odor in the conventional oil-based ink composition, and the above-mentioned release agent, together with the above-mentioned release assistant, cooperates after the handwriting is dried. Then, a continuous oily layer is formed on the writing surface, and the resin film containing the colorant is effectively separated from the writing surface. Like the Kingupen, Yotsute in lightening abraded handwriting in cloth or paper, it is possible to erase only the easily peeled its abrading portion.

Further, according to the ink composition of the present invention, since the release agent is a hardly volatile liquid substance, even after a long time has passed after writing, the writing surface and the resin layer containing the colorant still remain. Since it exists in between, the erasability of the handwriting is effectively retained. In particular, the ink composition of the present invention contains a water-soluble polyvinyl acetal resin as a film forming agent, and as an exfoliating agent, contains an aliphatic carboxylic acid ester which is liquid at room temperature and is hardly volatile as described above. Together, as a peeling aid, since it contains a polyoxyethylene polyoxypropylene block copolymer or a lanolin derivative or both together, due to their synergistic effect, not only excellent erasability with time, but also the material of the white plate Nevertheless, it has excellent erasability of handwriting, that is, there is no dependence of erasability on the material of the white board, and in particular, it has been difficult to obtain sufficient erasability in the past. Even in the case of plastic boards and painted boards, such as, etc., the erasability of handwriting is excellent.

In addition, when the ink composition of the present invention contains an emulsion or hydrosol of a water-insoluble resin or a water-solubilized resin as a film-forming auxiliary, when the ink is written, the resin is combined with the polyvinyl acetal resin. Since a handwriting is formed by forming a film while containing a colorant in cooperation with each other, the handwriting has not only excellent water resistance but also stable erasability regardless of temperature and humidity conditions.

[0053]

The present invention will be described below with reference to examples.
The present invention is not limited to these examples. In addition, in the following examples, the component amounts represent the amount by weight as an effective amount in the ink composition, and the balance is water. The block copolymer means a polyoxyethylene polyoxypropylene block copolymer.

Example 1 Colorant Carbon black 5 Dispersant Polyvinyl acetal resin ¹⁾ 1 Film forming agent Polyvinyl acetal resin ¹⁾ 1 Release agent Butyl isostearate (Emulgion) 4 Block copolymer 0.5 Surfactant Nonionic surfactant Activator 1 Antiseptic and antifungal agent (effective amount)

Example 2 Colorant Slenblue 3 Dispersant Polyvinyl acetal resin 2 Film forming auxiliary agent Polyurethane (Emulsion) ²⁾ 1.5 Release agent Cetyl stearate (Emulsion) 6 Block copolymer 2 Surfactant Nonionic interface Activator 0.5 Antiseptic and antifungal agent (effective amount)

Example 3 Colorant Carbon black 5 Dispersant Polyvinyl acetal resin 1 Film-forming agent Polyvinyl acetal resin 1 Release agent Butyl isostearate (emulsion) 4 Ethoxylated cholesterol ³⁾ 0.8 Surfactant Nonionic surfactant 1 Antiseptic and antifungal agent (effective amount)

Example 4 Colorant Slenblue 3 Dispersant Polyvinyl acetal resin 2 Film forming aid Polyurethane (Emulgion) 1.5 Release agent Cetyl stearate (emulsion) 6 Ethoxylated cholesterol 0.2 Surfactant Nonionic surfactant 0.5 Antiseptic and antifungal agent (effective amount)

Example 5 Colorant Carbon black 5 Dispersant Polyvinyl acetal resin 1 Film forming agent Polyvinyl acetal resin 1 Release agent Butyl isostearate (emulsion) 4 Block copolymer 0.5 Ethoxylated cholesterol 0.8 Surfactant nonion Surfactant 1 Antiseptic and antifungal agent (effective amount)

Example 6 Colorant Slenblue 3 Dispersant Polyvinyl acetal resin 2 Film forming aid Polyurethane (Emulgion) 1.5 Release agent Cetyl isostearate (Emulgion) 6 Block copolymer 2 Ethoxylated cholesterol 0.2 Surfactant Agent Nonionic surfactant 0.5 Antiseptic and antifungal agent (effective amount)

Comparative Example 1 Colorant Carbon black 5 Dispersant Polyvinyl acetal resin 1 Film forming agent Polyvinyl acetal resin 1 Release agent Butyl isostearate (Emulgion) 4 Surfactant Nonionic surfactant 1 Antiseptic and fungicide (effective amount)

Comparative Example 2 Colorant Slenblue 3 Film forming agent Polyvinyl acetal resin 2 Film forming auxiliary agent Polyurethane (Emulgion) 1.5 Release agent Cetyl stearate (Emulgion) 6 Surfactant Nonionic surfactant 0.5 Antiseptic Mold agent (effective amount)

(Note) 1) Esretk K manufactured by Sekisui Chemical Co., Ltd., aqueous solution (solid content 20% by weight) 2) Rikabond GL-39 manufactured by Chuo Rika Kogyo Co., Ltd., aqueous solution (solid content 30% by weight) 3) BELLPOL C-24 manufactured by Yoshikawa Essential Oil Co., Ltd. Using each of these ink compositions, write on a enamel white plate, a melamine resin white plate or a polyester white plate, and after 12 hours, write the dried handwriting with a load of 100 to 20.
The erasability of the handwriting was examined by rubbing with a dry cloth at 0 g. ◎
Indicates that the handwriting was erased after 1 to 3 times of rubbing (extremely good), ○ indicates that the handwriting was erased after 4 to 6 times (good), and Δ indicates that the handwriting was erased after 7 to 9 times of abrasion (slightly). Bad), ×
Indicates that the handwriting was erased after the number of rubbing was 10 or more, or the handwriting was not erased even after the number of rubbing was 10 or more. The results are shown in Table 1.

[0063]

[Table 1]

Claims (3)

[Claims] 1. (a) Water as a solvent, (b) a colorant dissolved or dispersed in water, (c) a polyvinyl acetal resin as a film-forming agent, and (d) a release agent, which is hardly volatilized at room temperature. Aqueous emulsion of water-soluble aliphatic carboxylic acid ester, and (e) Aqueous solution containing at least one selected from polyoxyethylene polyoxypropylene block copolymer and lanolin derivative as a release aid. Erasable marking pen ink composition. 2. A water-soluble resin, an emulsion or a hydrosol of a water-insoluble resin, or a resin which is essentially water-insoluble but is water-solubilized with a base as a film-forming auxiliary. Item 2. The water-based erasable marking pen ink composition according to item 1. 3. The aqueous erasable marking pen ink composition according to claim 1, wherein the lanolin derivative is ethoxylated cholesterol.