Solid writing body

Abstract

To accomplish compatibility between erasability and enhanced strength.SOLUTION: A solid writing body comprises N-hydroxyalkyl-12-hydroxy fatty acid amide, a surfactant having an HLB value of 8 or more, and a colorant.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a solid writing implement.

Background Art

[0002] Conventionally, solid writing implements that can write on smooth writing surfaces (hereinafter referred to as writing boards) such as whiteboards, color boards, glass, holographic plates, plastic plates, etc. and can erase the writing with water have been studied. In addition, solid writing implements with improved erasability of writing with water and water resistance of the writing have been disclosed (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the conventional solid writing implement with improved erasability of writing with water, the strength is low, and it has been difficult to achieve both erasability and improved strength.

[0005] An object of the present invention is to provide a solid writing implement capable of achieving both erasability and improved strength.

Means for Solving the Problems

[0006] In order to solve the above problems, the present invention provides "1. A solid writing implement comprising an N-hydroxyalkyl-12-hydroxy fatty acid amide, a surfactant having an HLB value of 8 or more, and a coloring material. 2. The solid writing implement according to Item 1, wherein the surfactant has an HLB value of 8 or more and 14 or less. 3. The N-hydroxyalkyl-hydroxy fatty acid amide is ​N-hydroxyalkyl-12-hydroxystearic acid amide The solid writing implement according to claim 1. 4. The content of the N-hydroxyalkyl-12-hydroxy fatty acid amide with respect to the total amount of the solid writing implement is 5% by mass or more and 60% by mass or less. The solid writing implement according to claim 1. 5. The content of the surfactant with respect to the total amount of the solid writing implement is 1% by mass or more and 50% by mass or less. The solid writing implement according to claim 1. 6. The ratio of the content of the N-hydroxyalkyl-12-hydroxy fatty acid amide and the surfactant with respect to the total amount of the solid writing implement is in the range of 1:10 to 10:1 by mass ratio. The solid writing implement according to claim 1 is used.

Effect of the Invention

[0007] The present invention can achieve both erasability and strength improvement.

Mode for Carrying Out the Invention

[0008] Hereinafter, embodiments of the present invention will be described in detail. In this specification, "parts", "%", "ratio", etc. indicating formulation are based on mass unless otherwise specified.

[0009] (Solid writing implement) The solid writing implement of this embodiment contains an N-hydroxyalkyl-12-hydroxy fatty acid amide, a surfactant having an HLB (Hydrophilic-Lipophilic Balance) value of 8 or more, and a coloring material.

[0010] The solid writing implement of this embodiment contains an N-hydroxyalkyl-12-hydroxy fatty acid amide, a surfactant having an HLB value of 8 or more, and a coloring material. Therefore, the solid writing implement of this embodiment can achieve both erasability and strength improvement.

[0011] In addition, the solid writing body of the present embodiment contains an N-hydroxyalkyl-12-hydroxy fatty acid amide and a surfactant with an HLB value of 8 or more. By doing so, in addition to the above effects, it is possible to improve water resistance, writing performance, and writing feel.

[0012] Hereinafter, each component constituting the solid writing body of the present embodiment will be described in detail.

[0013] (N-hydroxyalkyl-12-hydroxy fatty acid amide) The N-hydroxyalkyl-12-hydroxy fatty acid amide contained in the solid writing body of the present embodiment is a solid substance at normal temperature having formability. Therefore, since the solid writing body contains the N-hydroxyalkyl-12-hydroxy fatty acid amide, the solid writing body of the present embodiment can impart high heat resistance and strength to the solid writing body without impairing the handwriting formability, water resistance of the handwriting, and erasability with respect to a writing board wetted with water.

[0014] In consideration of highly improving various performances of the solid writing body, it is preferable that the N-hydroxyalkyl-12-hydroxy fatty acid amide has 1 to 4 carbon atoms in the hydroxyalkyl group and 12 to 20 carbon atoms in the hydroxy fatty acid amide. Further, it is more preferable that the N-hydroxyalkyl-12-hydroxy fatty acid amide has 1 to 3 carbon atoms in the hydroxyalkyl group and 14 to 20 carbon atoms in the hydroxy fatty acid amide. Moreover, it is particularly preferable that the N-hydroxyalkyl-12-hydroxy fatty acid amide has 1 to 3 carbon atoms in the hydroxyalkyl group and 16 to 20 carbon atoms in the hydroxy fatty acid amide.

[0015] By the solid writing body containing the N-hydroxyalkyl-12-hydroxy fatty acid amide having the carbon number within the above range, a smooth writing feel can be realized.

[0016] Examples of N-hydroxyalkyl-12-hydroxy fatty acid amides applicable to the solid writing instrument of the present embodiment specifically include product name: ITOHWAX J-420 (N-hydroxyethyl-12-hydroxystearic acid amide) manufactured by Ito Oil Co., Ltd., and product name: Parisin 220 (N-hydroxyethyl-12-hydroxystearic acid amide) manufactured by Vertellus Specialties. Note that the N-hydroxyalkyl-12-hydroxy fatty acid amides applicable to the solid writing instrument are not limited to these, and one or more types can be applied.

[0017] The content of N-hydroxyalkyl-12-hydroxy fatty acid amide with respect to the total amount of the solid writing instrument is preferably 5% by mass or more and 60% by mass or less, more preferably 8% by mass or more and 40% by mass or less, and particularly preferably 10% by mass or more and 35% by mass or less.

[0018] By adjusting the content of N-hydroxyalkyl-12-hydroxy fatty acid amide with respect to the total amount of the solid writing instrument within the above range, it is possible to improve the heat resistance, core strength, erasability and water resistance of the handwriting, and the handwriting formability on a writing board wetted with water of the solid writing instrument.

[0019] (Other waxes) The solid writing instrument of the present embodiment may further contain waxes other than the above N-hydroxyalkyl-12-hydroxy fatty acid amide. For example, the solid writing instrument of the present embodiment may further contain waxes such as 12-hydroxystearic acid, hydrogenated castor oil, acid-modified polyethylene wax, polypropylene wax, paraffin wax, fatty acid amide wax, polyethylene glycol fatty acid ester wax, etc.

[0020] (Surfactant) The solid writing instrument of the present embodiment contains a surfactant having an HLB value of 8 or more.

[0021] The HLB value of the surfactant in the present embodiment is a value obtained by the following Griffin's formula (1).

[0022] HLB value = (Molecular weight of hydrophilic group part / Molecular weight of surfactant) × 20 ··· Formula (1)

[0023] The surfactant used in the solid writing body of this embodiment preferably has an HLB value of 8 or more and 14 or less, more preferably 9 or more and 13 or less, and particularly preferably 10 or more and 12 or less.

[0024] By including a surfactant having an HLB value within the above range, the solid writing body of this embodiment can achieve the effect of having good water resistance of the handwriting as well as erasability of the handwriting.

[0025] Examples of the surfactant having an HLB value within the above range include glycerin fatty acid ester, polyglycerin fatty acid ester, sucrose fatty acid ester, sorbitan fatty acid ester, polyoxyethylene alkyl ether, polyalkylene alkyl ether, and the like.

[0026] Among these, from the viewpoints of high core strength and good handwriting formability, as the surfactant used in the solid writing body of this embodiment, it is more preferable to use one or more selected from glycerin fatty acid ester, polyglycerin fatty acid ester (SY Glister), and polyoxyethylene alkyl ether (Emulgen).

[0027] Specific examples of the polyglycerin fatty acid ester include SY Glister MS-5S (manufactured by Sakamoto Yakuhin Kogyo Co., Ltd.), SY Glister TS-7S (manufactured by Sakamoto Yakuhin Kogyo Co., Ltd.), SY Glister MS-3S (manufactured by Sakamoto Yakuhin Kogyo Co., Ltd.), SY Glister MM-750 (manufactured by Sakamoto Yakuhin Kogyo Co., Ltd.), Ryoto Sugar Ester S-1570 (manufactured by Mitsubishi Chemical Corporation), and the like.

[0028] The content of the surfactant having an HLB value of 8 or more with respect to the total amount of the solid writing body is preferably 1% by mass or more and 50% by mass or less, more preferably 3% by mass or more and 40% by mass or less, and particularly preferably 5% by mass or more and 30% by mass or less.

[0029] By setting the content of the surfactant within the above range, the solid writing implement of the present embodiment can achieve the effect that while maintaining high core strength, the erasability and water resistance of the writing are improved.

[0030] (Ratio of the content of N-hydroxyalkyl-12-hydroxy fatty acid amide and a surfactant with an HLB value of 8 or more) The ratio of the content of N-hydroxyalkyl-12-hydroxy fatty acid amide contained in the solid writing implement of the present embodiment to a surfactant with an HLB value of 8 or more is preferably in the range of 1:10 to 10:1, more preferably in the range of 1:5 to 5:1, and particularly preferably in the range of 1:3 to 3:1 in terms of mass ratio (N-hydroxyalkyl-12-hydroxy fatty acid amide: surfactant with an HLB value of 8 or more).

[0031] When the ratio of the content of N-hydroxyalkyl-12-hydroxy fatty acid amide contained in the solid writing implement to a surfactant with an HLB value of 8 or more is within the above range, it is possible to achieve both excellent water erasability of the writing and improvement in the strength of the solid writing implement, as well as improvement in water resistance, writability on a non-permeable surface, and writing feel.

[0032] (Colorant) The colorant used in the solid writing implement of the present embodiment is not particularly limited, and conventionally known dyes and pigments can be applied.

[0033] Examples of the dye include acid dyes, basic dyes, direct dyes, reactive dyes, vat dyes, sulfur dyes, metal-containing dyes, cationic dyes, and disperse dyes. Further, phthalocyanine-based dyes, pyrazolone-based dyes, nigrosine-based dyes, anthraquinone-based dyes, azo-based dyes, etc. can be mentioned.

[0034] Examples of pigments include inorganic pigments, organic pigments, white pigments, fluorescent pigments, and metallic pigments. Specifically, examples of inorganic pigments include carbon black, iron black, ultramarine, yellow iron oxide, cadmium red, and composite oxide-based pigments. Examples of organic pigments include azo-based pigments, indigo-based pigments, phthalocyanine-based pigments, quinacridone-based pigments, thioindigo-based pigments, perylene-based pigments, perinone-based pigments, dioxane-based pigments, isoindolinone-based pigments, metal complex-based pigments, methine-azomethine-based pigments, and diketopyrrolopyrrole-based pigments. Examples of white pigments include titanium oxide, zinc oxide, and zinc white. Examples of metallic pigments include pearl pigments, metal foil pigments, glass flake pigments, and flaky metal pigments coated with a resin film.

[0035] Considering the clarity and erasability of the handwriting, it is preferable to use a pigment as the coloring material. Further, as the coloring material, one or more of the plurality of types of coloring materials listed above can be used.

[0036] The content of the coloring material with respect to the total amount of the solid writing body is preferably 1% by mass or more and 50% by mass or less, more preferably 2% by mass or more and 45% by mass or less, still more preferably 5% by mass or more and 40% by mass or less, and particularly preferably 10% by mass or more and 40% by mass or less with respect to the total amount of the solid writing body.

[0037] When the content of the colorant with respect to the total amount of the solid writing body is within the above range, the visibility and erasability of the handwriting can be improved.

[0038] (Aliphatic alcohol) An aliphatic alcohol that is solid at normal temperature and pressure may be added to the solid writing body of the present embodiment.

[0039] The aliphatic alcohol can improve the handwriting formability and heat resistance of the solid writing body, the water resistance and erasability of the handwriting, and can increase the strength of the solid writing body.

[0040] Examples of the aliphatic alcohol include linear aliphatic alcohols having 14 or more carbon atoms such as myristyl alcohol, palmityl alcohol, stearyl alcohol, arachyl alcohol, behenyl alcohol, lignoceryl alcohol, 1-triacontanol, 1-tetracosanol, and 1-pentacosanol. From the viewpoint of enhancing the strength of the solid writing implement, the linear aliphatic alcohol is preferably a primary alcohol. Further, from the viewpoints of improving the writing traceability, heat resistance, water resistance, and erasability of the writing trace of the solid writing implement, the number of carbon atoms of the linear aliphatic alcohol is preferably 50 or less.

[0041] (Gelling agent) A gelling agent may be added to the solid writing implement of the present embodiment. By adding the gelling agent, the writing feel of the solid writing implement can be improved. Examples of the gelling agent include benzylidene sorbitols, 12-hydroxystearic acid, and the like.

[0042] (Extender) An extender may be added to the solid writing implement of the present embodiment. Examples of the extender include talc, clay, silica, calcium carbonate, barium sulfate, alumina, mica, potassium titanate, corn starch, starch, boron nitride, and the like.

[0043] In addition, resins such as polyvinyl alcohol, polyvinylpyrrolidone, polyethylene glycol, and cellulose derivatives, a viscosity modifier, a fragrance, an antibacterial agent, a fungicide, and the like can be added to the solid writing implement as needed.

[0044] (Method for manufacturing a solid writing implement) The solid writing implement of the present embodiment is produced by fractionating a predetermined amount of a wax containing N-hydroxyalkyl-12-hydroxy fatty acid amide and a surfactant having an HLB value of 8 or more, melting these by heating them to their melting temperatures (for example, 90°C to 120°C). Then, a predetermined amount of a coloring material is further fractionated, added to the melt, and kneaded uniformly. Then, the kneaded product is extruded through an extruder as a core having a predetermined diameter to produce the solid writing implement.

Example

[0045] Hereinafter, the present invention will be specifically described by way of examples. However, the present invention is not limited to the following examples.

[0046] (Examples 1 to 19, Comparative Examples 1 to 4) The wax shown in the table (N-hydroxyalkyl-12-hydroxy fatty acid amide), other waxes other than the wax, and the surfactant were weighed in the compounding amounts shown in the table and melted by heating to 90°C to 120°C. Then, the coloring material weighed was added to the melted material in the compounding amount shown in the table and kneaded for 1 hour. Then, the kneaded product obtained by kneading was extruded by an extruder as a columnar core with a diameter of 3 mm to produce a solid writing body. The content of each material shown in the table is expressed as a mass percentage of the content with respect to the total amount of the solid writing body or the comparative solid writing body.

[0047] (Evaluation) For each of the produced solid writing bodies of the examples and the comparative solid writing bodies of the comparative examples, the following evaluations were carried out. In the evaluation criteria, "〇" indicates the best evaluation result, "△" indicates an intermediate evaluation result between "〇" and "×", and "×" indicates the worst evaluation result.

[0048] (Evaluation of the strength of the solid writing body) For each of the solid writing body and the comparative solid writing body, a test was carried out according to the test method described in JIS S 6006:2020 (Pencils, colored pencils and leads used for them), and the numerical value when the core body broke was read. A small desktop tester (product name: EZ-SX, manufactured by Shimadzu Corporation) was used as the tester. The evaluation results are shown in the table.

[0049] (Evaluation of the writing performance of the solid writing body) For each of the solid writing body and the comparative solid writing body, handwriting was done on high-quality paper and a plastic plate (PP) by hand, and the density of the handwriting was observed visually. Then, the writing performance was evaluated by a sensory test according to the following evaluation criteria. The evaluation results are shown in the table.

[0050] Evaluation Criteria for Handwriting ○: Dark and Clear △: Slightly Light but Visible ×: Unable to Write

[0051] (Evaluation of Erasability of Handwriting) After writing on a plastic plate (PP) using each of the solid writing bodies and relatively solid writing bodies, the remaining state of the handwriting after reciprocating the handwriting 10 times with a tissue containing water was visually observed. Then, the erasability was evaluated by a sensory test according to the following evaluation criteria. The evaluation results are shown in a table.

[0052] Evaluation Criteria for Erasability ○: No Handwriting Remains ×: Handwriting Remains

[0053] (Evaluation of Water Flow Resistance of Handwriting) After writing on a plastic plate (PP) using each of the solid writing bodies and relatively solid writing bodies, the handwriting after flowing water was applied to the handwriting for 10 minutes was visually observed. Then, the water flow resistance was evaluated by a sensory test according to the following evaluation criteria. The evaluation results are shown in a table.

[0054] Evaluation Criteria for Water Flow Resistance ○: No Change in Handwriting △: Traces of partial loss of handwriting can be seen ×: No Handwriting Remains

[0055] (Evaluation of Water Resistance of Handwriting in Water) After writing on a plastic plate (PP) using each of the solid writing bodies and relatively solid writing bodies, the handwriting after immersing the plastic plate in water for 1 day was visually observed. Then, the water resistance in water was evaluated by a sensory test according to the following evaluation criteria. The evaluation results are shown in a table.

[0056] Evaluation Criteria for Water Resistance in Water ○: No Change in Handwriting △: Traces of partial loss of handwriting can be seen ×: No Handwriting Remains

[0057] (Evaluation of writing feel) The feel when writing by hand on high-quality paper using each of the solid writing bodies and the relatively solid writing bodies was confirmed. Then, the writing feel was evaluated by a sensory test according to the following evaluation criteria. The evaluation results are shown in a table.

[0058] Evaluation criteria for writing feel ○: Smooth and no snagging. △: Slight feeling of weight or snagging. ×: Heavy and snagging.

[0059] [Table 1]

[0060] [Table 2]

[0061] [Table 3]

[0062] [Table 4]

[0063] As shown in Tables 1 to 4, it was confirmed that the solid writing body of the example can achieve both excellent water erasability and strength improvement compared to the relatively solid writing body. In addition, it was confirmed that the solid writing body of the example can obtain good results in terms of any of writing property, running water resistance, water resistance in water, and writing feel, compared to the relatively solid body. [Industrial applicability]

[0064] The present invention can be used as a solid writing body. In particular, it can be suitably used when writing in an environment such as outdoors where it is easily wetted by rain or water.

Claims

1. A solid writing implement comprising an N-hydroxyalkyl-12-hydroxy fatty acid amide, a surfactant having an HLB value of 8 or more, and a coloring material.

2. The solid writing implement according to Claim 1, wherein the surfactant has an HLB value of 8 or more and 14 or less.

3. The N-hydroxyalkyl-12-hydroxy fatty acid amide is N-hydroxyalkyl-12-hydroxystearic acid amide. The solid writing implement according to Claim 1.

4. The content of the N-hydroxyalkyl-12-hydroxy fatty acid amide relative to the total amount of the solid writing implement is 5% by mass or more and 60% by mass or less. The solid writing implement according to Claim 1.

5. The content of the surfactant relative to the total amount of the solid writing implement is 1% by mass or more and 50% by mass or less. The solid writing implement according to Claim 1.

6. The ratio of the content of the N-hydroxyalkyl-12-hydroxy fatty acid amide and the surfactant relative to the total amount of the solid writing implement is in the range of 1:10 to 10:1 by mass ratio. The solid writing implement according to Claim 1. ​ ​

Images