Ink for non-absorbent surface and application tool

Abstract

To provide an ink for non-absorbent surfaces, the ink being excellent in erasability after writing has been performed on the non-absorbent surface.SOLUTION: An ink for non-absorbent surfaces comprises a pigment and a synthetic latex, the ink having a vapor pressure within a range of 10.0 to 12.3 kPa at 50°C.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to inks and applicators for non-absorbent surfaces that can be rubbed off after writing. [Background technology]

[0002] When manufacturing leather products such as leather shoes, a marker called a "silver pen" is used to mark the cutting and sewing stages, leaving lines and marks. These lines and marks need to be erased during the manufacturing process, but existing silver pens have poor erasability and leave some marks unerased, which can affect workability.

[0003] Inks with excellent erasability have been proposed that take into consideration the penetrability into paper surfaces (see, for example, Patent Documents 1 to 3), but erasability from non-absorbent surfaces such as leather has not been studied. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 10-46093 [Patent Document 2] Japanese Patent Application Publication No. 5-279614 [Patent Document 3] Japanese Patent Application Publication No. 5-214285 Summary of the Invention [Problem to be solved by the invention]

[0005] An object of the present invention is to provide an ink for non-absorbent surfaces that has excellent erasability after writing on the non-absorbent surface, and to provide an applicator that uses this ink for non-absorbent surfaces. [Means for solving the problem]

[0006] As a result of extensive research, the present inventors have found that the above problems can be solved by including a predetermined component and further adjusting the vapor pressure within a predetermined range, and have thus completed the present invention.

[0007] That is, according to the present invention, (1) An ink for non-absorbent surfaces, which contains a pigment and a synthetic latex, and which has a vapor pressure of 10.0 to 12.3 kPa at 50°C. (2) The ink for non-absorbent surfaces according to (1), wherein the ratio of the solid content mass of the pigment to the solid content mass of the synthetic latex (pigment solid content mass / synthetic latex solid content mass) is 0.01 to 0.50. (3) The ink for non-absorbent surfaces according to (1) or (2), wherein the glass transition temperature (Tg) of the synthetic latex is 25° C. or lower. (4) The ink for non-absorbent surfaces according to (3), wherein the synthetic latex is at least one of an acrylonitrile-butadiene-based latex and a styrene-butadiene-based latex. (5) The ink for non-absorbent surfaces according to (1) or (2), wherein the pigment is a hollow particle. (6) An applicator for non-absorbent surfaces, in which the non-absorbent ink according to (1) or (2) is filled in a container, and which is provided with an eraser at one end of the container. is provided. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide an ink for non-absorbent surfaces that has excellent erasability after writing on a non-absorbent surface, and also to provide an applicator that uses this ink for non-absorbent surfaces. [Brief explanation of the drawings]

[0009] [Figure 1] 1A and 1B are drawings showing an example of an applicator, in which (a) is a front view and (b) is a plan view. [Figure 2] 1A and 1B are diagrams showing an example of an applicator, in which (a) is a longitudinal cross-sectional view in front view, and (b) is a transverse cross-sectional view in plan view. DETAILED DESCRIPTION OF THE INVENTION

[0010] The ink for non-absorbent surfaces of the present invention is described below. The ink for non-absorbent surfaces of the present invention is an ink for non-absorbent surfaces containing a pigment and a synthetic latex, and the vapor pressure of the ink for non-absorbent surfaces at 50°C is 10.0 to 12.3 kPa.

[0011] (pigment) The pigment used in the ink for non-absorbent surfaces of the present invention may be a colorant used in writing instruments, and examples thereof include dyes that dissolve or disperse in water, conventionally known inorganic and organic pigments such as titanium oxide, colored resin microparticles or dispersions thereof (including resin particle pigments containing pigments, pseudo-pigments in which resin emulsions are colored with dyes, white plastic pigments, hollow resin pigments (particles), etc.), pigments with a silica or mica base and a surface layer coated with a multilayer of iron oxide, titanium oxide, etc., and composite pigments of these. Examples of the dye include fluorescent dyes, water-soluble dyes, and oil-soluble dyes.

[0012] The fluorescent dyes that can be used are not particularly limited as long as they have good color development properties, and examples thereof include Basic Yellow 1, Basic Yellow 40, Basic Red 1, Basic Red 1:1, Basic Violet 13, Basic Violet 7, Basic Violet 10, Basic Violet 11:1, Basic Orange 22, Basic Blue 7, Basic Green 1, Acid Yellow 3, Acid Yellow 7, Acid Red 52, Acid Red 77, Acid Red 87, Acid Red 92, Acid Blue 9, Disperse Yellow 121, Disperse Yellow 82, Disperse Yellow 83, Disperse Orange 11, Disperse Red 58, Disperse Blue 7, Direct Yellow 85, Direct Orange 8, Direct Red 9, Direct Blue 22, Direct Green 6, Solvent Yellow 44, Solvent Red 49, Solvent Blue 5, and Solvent Green 7. Among the fluorescent dyes, azomethine-based, xanthene-based, and triphenylmethane-based fluorescent dyes are particularly preferred from the standpoints of color development properties and ink stability. Specifically, particularly preferred fluorescent dyes include azomethine fluorescent dyes such as Basic Yellow 1 and Basic Yellow 40, xanthene fluorescent dyes such as Basic Red 1:1 and Basic Violet 11:1, and triphenylmethane fluorescent dyes such as Basic Violet 1. These dyes may be used alone or in combination of two or more.

[0013] Examples of oil-soluble dyes include CI Solvent Black 7, 123, CI Solvent Blue 2, 25, 55, 70, CI Solvent Red 8, 49, 100, CI Solvent Violet 8, 21, CI Solvent Green 3, CI Solvent Yellow 21, 44, 61, and CI Solvent Orange 37.

[0014] Examples of water-soluble dyes include acid dyes, basic dyes, direct dyes, and food dyes. For example, CI Acid Black 1, 2, 24, 26, 31, 52, 107, 109, 110, 119, and 154, CI Acid Yellow 1, 7, 17, 19, 23, 25, 29, 38, 42, 49, 61, 72, 78, 110, 127, 135, 141, and 142, and CI Acid Red 8, 9, 14, 18, 26, 27, 35, and 37. CI 51, CI 52, CI 57, CI 82, CI 83, CI 87, CI 92, CI 94, CI 111, CI 129, CI 131, CI 138, CI 186, CI 249, CI 254, CI 265, CI 276, CI Acid Violet 15, CI 17, CI 49, CI Acid Blue 1, CI 7, CI 9, CI 15, CI 22, CI 23, CI 25, CI 40, CI 41, CI 43, CI 62, CI 78, CI 83, CI 90, CI 93, CI 100, CI 103, CI 104, CI 11 Acid dyes such as CI 2, CI 113, CI 158, CI Acid Green 3, CI 9, CI 16, CI 25, CI 27, CI Acid Orange 56, basic dyes such as Malachite Green (CI 42000), Victoria Blue FB (CI 44045), Methyl Violet FN (CI 42535), Rhodamine F4G (CI 45160), Rhodamine 6GCP (CI 45160), CI Direct Black 17, CI 19, CI 2 2, 32, 38, 51, 71, CI Direct Yellow 4, 26, 44, 50, CI Direct Red 1, 4, 23, 31, 37, 39, 75, 80, 81, 83, 225, 226, 227, CI Direct Blue 1, 15, 41, 71, 86, 87, 106, 108, 199, and other direct dyes, as well as food dyes such as CI Food Yellow 3.

[0015] Examples of inorganic pigments include carbon black, titanium black, zinc white, red iron oxide, aluminum, chromium oxide, iron black, cobalt blue, iron oxide yellow, viridian, zinc sulfide, lithopone, cadmium yellow, vermilion, cadmium red, yellow lead, molybdate orange, zinc chromate, strontium chromate, white carbon, clay, talc, ultramarine, precipitated barium sulfate, baryte powder, calcium carbonate, white lead, dark blue, iron blue, manganese violet, aluminum powder, and brass powder.

[0016] Examples of organic pigments include azo lakes, insoluble azo pigments, chelate azo pigments, phthalocyanine pigments, perylene and perinone pigments, and nitroso pigments. Specific examples include CI Pigment Blue 15, 17, CI Pigment Red 5, 22, 38, 48, 49, 53, 57, 81, 146, and 245, CI Pigment Yellow 1, 3, 12, 13, 14, 17, 55, 74, 95, 166, and 167, CI Pigment Orange 5, 13, and 16, CI Pigment Violet 1, 3, 19, 23, and 50, and CI Pigment Green 7.

[0017] Examples of colored resin microparticles or dispersions thereof include a dispersion of colored resin microparticles in which colored resin microparticles composed of at least a carboxyl group-containing vinyl monomer (A) having a solubility in water of 10% by mass or less as an acidic functional group, an ester monomer (B) of acrylic acid or methacrylic acid with a linear or cyclic alcohol having 2 to 18 carbon atoms, and a basic dye or oil-soluble dye are dispersed in water; and a dispersion of colored resin microparticles in which colored resin microparticles composed of a cyclohexyl (meth)acrylate monomer and a basic dye or oil-soluble dye are dispersed in water, wherein the content of the cyclohexyl (meth)acrylate monomer is 30% by mass or more relative to the total polymer components constituting the colored resin microparticles, and the content of the basic dye or oil-soluble dye is 15% by mass or more relative to the total polymer components.

[0018] These pigments can be used alone or in combination of two or more. For example, from the viewpoint of being usable on both black non-absorbent surfaces and white non-absorbent surfaces, it is preferable to use a white pigment (also known as a masking agent) in combination with a non-white pigment (i.e., a coloring pigment). The total solid content of these pigments is preferably 0.1 to 40% by mass, and more preferably 1 to 30% by mass, based on the total amount of the ink for non-absorbent surfaces.

[0019] By ensuring that the total pigment solids content is at least as high as the lower limit of the above range, sufficient line density can be obtained, while by ensuring that the total pigment solids content is at most the upper limit of the above range, an increase in viscosity can be suppressed, and the fluidity of the ink can be improved.

[0020] From the viewpoint of improving erasability, the particle size of the pigment used in the present invention is preferably 50 to 1,000 nm, more preferably 100 to 500 nm. In the present invention, the "particle size of the pigment" is the D50 value calculated on a volume basis with a refractive index of 1.81 using an FPAR-1000 (manufactured by Otsuka Electronics Co., Ltd.) or a particle size distribution analyzer HR9320-X100 (manufactured by Nikkiso Co., Ltd.).

[0021] (synthetic latex) The synthetic latex used in the ink for non-absorbent surfaces of the present invention preferably has a glass transition temperature (Tg) of 25°C or lower, more preferably 0°C or lower, and even more preferably -30°C or lower. When the Tg is within this range, a film suitable for erasing after writing can be formed. In other words, in the present invention, the synthetic latex functions as a film-forming agent. As such synthetic latex, it is preferable to use an acrylonitrile-butadiene latex or a styrene-butadiene latex.

[0022] The mass ratio of the solid content of the pigment to the solid content of the synthetic latex (mass of pigment solid content / mass of synthetic latex) is preferably 0.01 to 0.50, more preferably 0.05 to 0.30, and even more preferably 0.25 to 0.30.

[0023] (Other ingredients) The ink for non-absorbent surfaces of the present invention may contain, in addition to the above-mentioned pigment, synthetic latex, and the remainder water (tap water, purified water, distilled water, ion-exchanged water, pure water, etc.) as a solvent, various components commonly used in aqueous inks, such as dispersants, surfactants, water-soluble organic solvents, hydrophilic polyhydric alcohols, water-soluble betaines, viscosity adjusters, fixing resins, rust inhibitors, preservatives or antibacterial agents, pH adjusters, etc., as needed, within the scope of the present invention.

[0024] Examples of water-soluble organic solvents include glycols such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, polyethylene glycol, 3-butylene glycol, thiodiethylene glycol, and glycerin, as well as ethylene glycol monomethyl ether and diethylene glycol monomethyl ether, and these can be used alone or in combination of two or more.

[0025] The hydrophilic polyhydric alcohols are preferably not solvents but powders at room temperature, such as pentaerythritol, trimethylolethane, and trimethylolpropane, and examples of water-soluble betaines (amphoteric compounds) include trimethylglycine.

[0026] (Ink for non-absorbent surfaces) The ink for non-absorbent surfaces of the present invention can be obtained by mixing the above-mentioned pigment, synthetic latex, solvent, and other components used as needed. The mixing method is not particularly limited, and the ink can be stirred and mixed using a stirrer such as a homomixer, homogenizer, or disperser. Furthermore, if necessary, coarse particles in the ink for non-absorbent surfaces can be removed by filtration or centrifugation.

[0027] The vapor pressure of the ink for non-absorbent surfaces of the present invention at 50°C is 10.0 to 12.3 kPa, preferably 11 to 12.3 kPa, and more preferably 11.5 to 12.0 kPa. Here, the vapor pressure is measured by the static method. When the vapor pressure is within the above range, the effect of achieving both drying of the pen tip and drying of the drawn line is achieved. If the vapor pressure is below the above range, there is a concern that the pen tip may dry up, and if it is above the above range, there is a concern that drying of the drawn line may be impaired.

[0028] The viscosity of the ink for non-absorbent surfaces of the present invention is preferably 1 to 50 mPa·s (25°C, 10 rpm), more preferably 10 to 30 mPa·s (25°C, 10 rpm), and the surface tension is preferably 20 to 50 mN / m. Having a viscosity within the above range provides the effect of suppressing ink dripping and blurred lines. If the viscosity is below the above range, there is a risk of ink dripping, and if it is above the above range, there is a problem of blurred lines occurring during writing.

[0029] Furthermore, by ensuring that the surface tension is within the above range, it is possible to obtain the effect of achieving both good ink resistance and good ink impregnation. If the surface tension is below the above range, there is a concern that the ink may drip, and if it is above the above range, there is a concern that the ink may not impregnate the pen core.

[0030] The ink for non-absorbent surfaces of the present invention can be suitably used on leather products or leather materials, glass-plastic products or glass-plastic materials. That is, non-absorbent surfaces include leather, glass, plastic, etc. Among these, the ink is particularly suitable for use on leather products or leather materials, and is even more suitable for use on leather shoes.

[0031] (applicator) Furthermore, in the present invention, from the viewpoint of ink ejection properties, visibility, and erasability after writing, an applicator in which the non-absorbent ink is filled in a padded or valve-type container is preferred, and the writing flow rate of the applicator is preferably 50 mg / 100 m to 1000 mg / 100 m. By having a writing flow rate within the above range, the effect of achieving both smearing and quick drying of drawn lines can be achieved. However, if the writing flow rate is greater than the above range, there is a problem that the lines do not dry.

[0032] That is, the ink for non-absorbent surfaces of the present invention can be filled into a padded, valve-type container and used as an applicator. The applicator is preferably one having an eraser at one end. The eraser is not particularly limited as long as it can erase drawn lines by rubbing, but examples include those made of rubber, such as erasers, and cloth, such as towels soaked in water.

[0033] Although there is no particular limitation on such applicators having an eraser at one end, an example is the applicator shown in Fig. 1. As shown in Figs. 1(a) to (b) and 2(a) to (b), applicator 2 is a twin-type applicator equipped with a flat-shaped nib 6 that guides the ink for non-absorbent surfaces of the present invention supplied from applicator body (barrel) 4, and also equipped with a rod-shaped nib 8 on the opposite side of nib 6. Here, nib 6 is made of, for example, a porous material, and nib 8 is made of, for example, polyacetal resin.

[0034] A cap 10 for protecting the pen tip 6 and a stand-type cap 12 for protecting the pen tip 8 are detachably provided on both ends of the applicator body 4. An eraser 14 made of elastomer is provided at the tip of the cap 10.

[0035] The applicator body 4 is composed of a cylindrical rear barrel 16 and a generally circular front barrel 18. The rear barrel 16 contains a filler 20 impregnated with the ink for use on non-absorbent surfaces of the present invention. The filler 20 is an ink absorbing body and is porous. The filler having a porous structure can be obtained by combining one or more materials selected from the group consisting of natural fibers, animal hair fibers, polyacetal resins, acrylic resins, polyester resins, polyamide resins, polyurethane resins, polyolefin resins, polyvinyl resins, polycarbonate resins, polyether resins, and polyphenylene resins.

[0036] In addition, flat portions 22 are formed on the upper and lower surfaces of the outer periphery on the axially forward side of rear barrel 16, and are configured so that when flat portion 22 is gripped with the fingers, writing can be performed without changing the grip. In other words, flat portion 22 serves as a gripping indication surface that makes it easy to determine the orientation of flat-shaped pen tip 6.

[0037] In this way, by filling a container with the non-absorbent surface ink of the present invention and using an applicator equipped with an eraser at one end of the container, it is possible to write effectively on non-absorbent surfaces and to erase the drawn lines effectively after writing. [Example]

[0038] The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited to these examples. In the following, "parts" are based on mass unless otherwise specified. Measurements and evaluations in the examples and comparative examples were carried out as follows.

[0039] (Visibility (black leather)) The inks obtained in the examples and comparative examples were filled into applicators 2 shown in Figs. 1 and 2, respectively, and writing was carried out on black leather using pen tip 6, and visibility was evaluated according to the following criteria. 〇…The lines were visible ×: The lines could not be confirmed

[0040] (Visibility (white leather)) The inks obtained in the examples and comparative examples were filled into applicators 2 shown in Figs. 1 and 2, respectively, and writing was carried out on white leather using pen tip 6, and visibility was evaluated according to the following criteria. 〇…The lines were visible ×: The lines could not be confirmed

[0041] (erasability) For those that were rated "good" in the visibility (black leather) and visibility (white leather) ratings, the written lines were rubbed with the eraser 14 attached to the applicator 2 shown in Figures 1 and 2. The erasability was evaluated according to the following criteria. 〇…The lines were visible ×: The lines could not be confirmed

[0042] Example 1 An ink for non-absorbent surfaces was obtained by combining 17.6 parts of a white pigment (Ultra E (30% solids); hollow particles, particle size 200-500 nm), 64.6 parts of Nipol 1571C2 (acrylonitrile-butadiene latex; Tg -30°C) as a film-forming agent, 9.4 parts of Nutristim Pure AH as a solvent (humectant), 0.2 parts of Biocide 1700 as a preservative, and 8.2 parts of ion-exchanged water. The vapor pressure of the resulting ink was measured at 50°C using the static method. The visibility and erasability on black and white leather were also evaluated. The results are shown in Table 1.

[0043] Example 2 A non-absorbing surface ink was obtained in the same manner as in Example 1, except that a blue pigment (blue pigment (pigment content 17%), particle size 100 to 130 nm) was used instead of the white pigment (ultra E (solid content 30%)). The vapor pressure of the resulting ink was measured at 50°C using the static method. The visibility and erasability on black and white leather were also evaluated. The results are shown in Table 1.

[0044] Example 3 A non-absorbent surface ink was obtained in the same manner as in Example 1, except that the pigment formulation was changed to 8.8 parts of white material (Ultra E (solid content 30%); hollow particles, particle size 200 to 500 nm) and 8.8 parts of blue material (blue pigment (pigment content 17%), particle size 100 to 130 nm). The vapor pressure of the resulting ink was measured at 50°C using the static method. The visibility and erasability on black and white leather were also evaluated. The results are shown in Table 1.

[0045] Examples 4 to 6 In Examples 4 to 6, non-absorbent inks were obtained in the same manner as in Examples 1 to 3, except that C4850A (styrene-butadiene latex; Tg -58°C) was used as the film-forming agent instead of Nipol 1571C2 (acrylonitrile-butadiene latex; Tg -30°C). The vapor pressure of the resulting ink was measured at 50°C using the static method. The visibility and erasability on black and white leather were also evaluated. The results are shown in Table 1.

[0046] (Comparative Examples 1 to 3) In Comparative Examples 1 to 3, inks were obtained in the same manner as in Examples 1 to 3, except that no film-forming agent (latex) was added. The vapor pressure of the obtained inks at 50°C was measured using the static method. In addition, the visibility and erasability on black and white leather were evaluated. The results are shown in Table 1.

[0047] [Table 1]

[0048] As shown in Table 1, it was found that ink for non-absorbent surfaces containing a pigment and synthetic latex, and having a vapor pressure of 10.0 to 12.3 kPa at 50°C, had excellent visibility and erasability. [Industrial Applicability]

[0049] The ink for non-absorbent surfaces of the present invention can be suitably used on leather products or leather materials, glass-plastic products or glass-plastic materials, and is particularly suitable for leather products or leather materials, and particularly suitable for leather shoes. [Explanation of symbols]

[0050] 2...applicator, 4...applicator body, 6...pen tip, 8...pen tip, 10...cap, 12...stand-type cap, 14...eraser, 20...filling

Claims

1. An ink for non-absorbent surfaces, comprising a pigment and a synthetic latex, wherein the ink for non-absorbent surfaces has a vapor pressure of 10.0 to 12.3 kPa at 50°C.

2. 2. The ink for non-absorbent surfaces according to claim 1, wherein the ratio of the solid content mass of the pigment to the solid content mass of the synthetic latex (solid content mass of pigment / solid content mass of synthetic latex) is 0.01 to 0.

50.

3. 3. The ink for non-absorbent surfaces according to claim 1, wherein the synthetic latex has a glass transition temperature (Tg) of 25[deg.] C. or less.

4. 4. The ink for non-absorbent surfaces according to claim 3, wherein said synthetic latex is at least one of an acrylonitrile-butadiene-based latex and a styrene-butadiene-based latex.

5. 3. The ink for non-absorbent surfaces according to claim 1, wherein said pigment is a hollow particle.

6. 3. An applicator for non-absorbent surfaces, comprising a container filled with the ink for non-absorbent surfaces according to claim 1 or 2, and an eraser provided at one end of the container.

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