JP2004148744A - Friction body and writing utensil - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a friction body which can change colors from a first state to a second state without requiring a protecting member such as an overcoat layer and without peeling off an image and a handwriting formed by a reversible thermal color changing ink, and at the same time, in which damages and wear caused by friction hardly occur, and which is high in durability due to repeated use, and further, to provide a writing utensil by which images can be freely formed with the reversible thermal color changing ink. <P>SOLUTION: The friction body 1 has elasticity to change the colors of an image formed by using the reversible thermal color changing ink 6 from the first state to the second state by frictional heat. The friction body 1 is made of a silicone rubber. Further, at least the reversible thermal color changing ink 6 is incorporated in the writing utensil 2. The writing utensil 2, which is provided with the friction body 1 having the elasticity to change the colors of the handwriting formed by the writing utensil 2 from the first state to the second state by the frictional heat, is provided. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a friction body and a writing instrument. More specifically, the present invention relates to a friction body and a writing instrument having elasticity for discoloring an image or a handwriting formed from a reversible thermochromic ink from a first state to a second state by frictional heat.
[0002]
[Prior art]
BACKGROUND ART Conventionally, a thermochromic set including a friction body that changes the color of a reversible thermochromic layer formed on a support with frictional heat caused by manual friction has been proposed (see Patent Document 1).
The friction body used in the above proposal, when rubbed to generate frictional heat, peels off the reversible thermochromic layer and impairs the reversible color change, so that an overcoat layer is provided on the reversible thermochromic layer. It is necessary to prevent peeling.
Further, in the exemplified resin used for the rubbing portion of the friction body described in Patent Literature 1, the resin itself is scraped off by rubbing, so that scum may come out and contaminate the surroundings. Further, the number of times of rubbing may increase due to low efficiency of generating frictional heat.
Further, since the reversible thermochromic layer of Patent Document 1 is provided with an overcoat layer for preventing the rubbed portion of the reversible thermochromic image from peeling off, only the existing reversible thermochromic image can be discolored. It was not possible to change the color of the reversible thermochromic image freely formed by the user.
[0003]
[Patent Document 1]
JP-A-7-241388
[0004]
[Problems to be solved by the invention]
The present invention solves the above-mentioned problems, and does not require a protective member such as an overcoat layer, and discolors from the first state to the second state without peeling off the image or handwriting formed by the reversible thermochromic ink. An object of the present invention is to provide a friction member which is hardly damaged by friction and has high durability in repeated use.
It is still another object of the present invention to provide a writing implement provided with a friction body, which can change the color of an image formed freely with a reversible thermochromic ink.
[0005]
[Means for Solving the Problems]
The present invention provides a frictional body 1 having an elasticity for discoloring an image formed by using a reversible thermochromic ink 6 from a first state to a second state by frictional heat, wherein the frictional body 1 is made of silicone rubber. It is required that the friction body 1 contains a colorant, and that the colorant be contained in an amount of 0.1 to 1.0% by weight based on the total amount of the friction body 1.
Further, the writing implement 2 including at least the reversible thermochromic ink 6, comprising the friction body 1 having elasticity that changes the handwriting formed by the writing implement 2 from the first state to the second state by frictional heat, The friction body 1 is made of silicone rubber, the friction body 1 contains a colorant, the colorant is contained in an amount of 0.1 to 1.0% by weight based on the total amount of the friction body 1, That the rubbing portion 11 has a convex curved surface shape, the radius of curvature R of the convex curved surface is 1 mm to 10 mm, and the outer diameter D and the length L of the friction body 1 satisfy L <D. The frictional member 1 has a release force of 10 N or more, and the frictional member 1 satisfies L <D between an outer diameter D and an extension length L, and has a release force of 10 N or more. The reversible thermochromic ink 6 contains at least a microcapsule pigment. Contained, the microcapsule pigment is a requirement such that it has a maximum hot side color change point in the range of 25 ° C. to 65 ° C..
Further, the reversible thermochromic ink 6 is a heat-decoloring type in which a color is erased by heating from a color-developed state, a color storage-maintaining type in which a color-developed state or a decolored state is alternately stored and held in a specific temperature range, or It is required to be selected from any of the heating and coloring types in which a color is formed by heating from a color state and returned to a decolored state by cooling from the colored state.
[0006]
The present invention will be described with reference to the drawings (see FIGS. 1 to 6).
The friction body 1 of the present invention is to easily change the color of an image or handwriting formed by the reversible thermochromic ink 6 from the first state to the second state by frictional heat. The color changes alternately to a different color.
Silicone rubber is preferably used as the friction body 1.
[0007]
In addition, since the friction body 1 of the present invention can generate heat by manual operation without using power or the like, it can be manufactured at a low cost without requiring a large-scale device, and the writing implement 2 having the reversible thermochromic ink 6 incorporated therein. It can be provided at the rear end of the shaft barrel 5 or the top of the writing instrument cap 3 by fitting, two-color molding, or the like. Further, the writing implement 2 and the friction body 1 may be provided separately to form a reversible thermochromic set. In these cases, a free image can be formed by the writing implement 2, and the image can be easily discolored using the friction body 1.
A general-purpose elastic body can be used as the friction body 1 provided on the writing instrument 2, but it is preferable that the friction body 1 is silicone rubber.
[0008]
The silicone rubber can repeatedly and reversibly change color without peeling off the thermochromic image, whereas the eraser and other rubbers have a high erasing power when rubbed, so that the rubbing portion of the thermochromic image is high. Is peeled off, and the discoloration effect is impaired. Therefore, when the eraser or other rubber is used, it is preferable to provide a coating layer or the like to protect the image.
The silicone rubber has a high heat generation efficiency, and since the silicone rubber itself is hard to be scraped, the thermochromic image can be easily discolored without needing to scrape many times, and stains around the scraped portion with shavings. Can be used without. Further, since the resistance at the time of rubbing is small, rubbing can be performed smoothly.
[0009]
Further, a coloring agent can be added to the friction body 1. By coloring the friction body 1, it becomes rich in design. Further, when the friction body 1 is mounted on the writing instrument 2, the friction body 1 is colored in the ink color in the first state or the second state, and may be a color display function part for notifying the user of the color appearing in the first state or the discoloration. By coloring according to the exterior of the writing implement 2, the design can be unified.
The amount of the colorant added is preferably 0.1 to 1.0% by weight based on the total amount of the friction body 1. If the content is less than 0.1%, the friction body 1 cannot be colored sharply. If the content is more than 1.0%, the colorant is transferred around the handwriting when rubbed.
Generally, general-purpose dyes, pigments and the like can be appropriately used as the colorant.
Further, various additives such as a filler can be added to the friction body 1 as needed.
[0010]
Moreover, in the friction body 1 attached to the writing implement 2, the shape of the rubbing portion 11 can be a convex curved surface. By using a convex curved surface, the handwriting can be rubbed with an appropriate softness without peeling. In addition, a constant contact area can be obtained regardless of the contact angle with the handwriting, and only the target portion can be rubbed without rubbing over a wide area, the abrasion of the friction body 1 itself can be reduced, and the heat generation efficiency can be increased. As a result, it is possible to accurately and easily change the color of the portion to be changed without shavings.
Further, by setting the radius of curvature R of the convex curved surface in a range of 1 mm to 10 mm, the handwriting having a narrow width formed by the writing instrument 2 can be accurately and easily discolored.
[0011]
When the outer diameter D and the length L of the friction body 1 attached to the writing instrument 2 satisfy L <D, the friction body 1 can be prevented from wobbling or falling off during rubbing, and poor rubbing occurs. No more. It is preferable that the outer diameter D and the protruding length L satisfy 0.25 ≦ L / D ≦ 0.85.
[0012]
Furthermore, by setting the frictional force of the frictional body 1 to 10 N or more, the frictional body 1 cannot be easily removed from the writing instrument 2, and accidental ingestion of an infant or the like can be prevented. When the friction body 1 is attached to the writing implement 2, a locking rib 32 may be provided on the inner surface of the friction body fitting portion 31 of the writing implement 2 for the purpose of improving the detaching force.
[0013]
In addition, when the friction body 1 satisfies L <D between the outer diameter D and the protruding length L and has a pulling force of 10 N or more, the friction body 1 does not wobble or fall off during rubbing, and In addition, since it does not come off easily when pulled, the applicability as a product is high.
[0014]
Further, by providing the friction body 1 with a ventilation hole or a ventilation groove, the safety becomes higher even when an infant or the like ingests accidentally.
[0015]
Next, the reversible thermochromic ink 6 will be described.
The reversible thermochromic ink 6 that forms a reversible thermochromic image and handwriting reversibly discolored by the friction body 1 of the present invention has a heat-decoloring type in which a color is erased by heating from a colored state, a colored state or a decolored state. To be composed of various types such as a color storage type that alternately stores and retains data in a specific temperature range, or a heated color type that generates color by heating from an erased state and returns to an erased state by cooling from the colored state Accordingly, an image having a high magic property can be formed, such as an image in which an image discolored due to abrasion returns to the original color instantaneously, and an image capable of maintaining the discoloration due to abrasion in a wide temperature range. In addition, the reversible thermochromic ink 6 specifies the lowest color change point in the range of −30 ° C. to + 10 ° C., and the maximum high temperature color change point in the range of 36 ° C. to 65 ° C., so that the ink is in a normal state (every day). It is possible to effectively maintain the color exhibited in the living temperature range), and the practicality is high.
[0016]
In addition, the reversible thermochromic microcapsule pigment contained in the reversible thermochromic ink 6 incorporated in the writing implement 2 includes a conventionally known (A) electron donating color-forming organic compound and (B) electron accepting compound. And (c) a microcapsule containing a reversible thermochromic composition containing at least three essential components of a reaction medium for determining the temperature at which the two color development reactions occur, is effective. As the heating decoloring type for decoloring by heating, those described in JP-B-51-44706, JP-B-51-44707, and JP-B-1-29398, etc. proposed by the present applicant can be used. . The color change occurs before and after a predetermined temperature (color change point), and the color change state is exhibited in a temperature range equal to or higher than the complete decoloration temperature, a color development state in a temperature range equal to or lower than the full color development temperature, There is only one particular state in the region. That is, the other state is maintained while the heat or cold required for the state to develop is applied, but returns to the state exhibited in the normal temperature range when the heat or cold is no longer applied, hysteresis. Characteristics with relatively small width (ΔH _A = 1-7 ° C).
ΔH _A Is 3 ° C. or lower (a system in which a fatty acid ester having a ΔT value (melting point−cloud point) of 3 ° C. or lower and applied as a discoloration temperature controlling compound disclosed in Japanese Patent Publication No. 1-29398) is completely erased. Color temperature (t ₄ ) And full color temperature (t ₁ ), And shows a highly sensitive color change in response to temperature change. _A However, in a system of about 4 to 7 ° C., after discoloration, the appearance gradually returns to the original appearance, and the visual recognition effect can be enhanced (see FIG. 5).
In addition, the large hysteresis characteristics (ΔH) described in Japanese Patent Publication No. 4-17154, JP-A-7-179777, JP-A-7-33997, and JP-A-8-39936 proposed by the present applicant have been proposed. _B = 8 to 50 ° C), that is, the shape of the curve plotting the change in the coloring density due to the temperature change is opposite to the case where the temperature is increased from a lower temperature side than the discoloration temperature range. The color changes along a route that is significantly different from that when the color is lowered, and the full color development temperature (t ₁ ) Color development state in the following low temperature range or complete decolorization temperature (t ₄ ) The decoloring state in the above high temperature range is a specific temperature range [t ₂ ~ T ₃ (A substantially two-phase holding temperature range)], a color storage-maintaining thermochromic composition capable of storing and storing in a temperature range (see FIG. 6).
Although the substantial two-phase holding temperature range can be set according to the purpose, in the present invention, the high-temperature side discoloration point is set in a range of 25 ° C to 65 ° C (preferably 36 ° C to 65 ° C).
In addition, the discoloration point at the lowest temperature [complete color development temperature (t ₁ )] Can be set to any temperature selected from the range of −30 ° C. to + 20 ° C. (preferably −30 ° C. to + 10 ° C.).
By the temperature setting, the color development start temperature (t ₂ ) And decolorization start temperature (t ₃ ) At any temperature, the color-developed state or the decolored state can be stored alternately and visualized.
Further, as a heat-colorable composition, a specific color having a linear or side chain alkyl group having 3 to 18 carbon atoms as an electron accepting compound according to the proposal of the present applicant, which develops a color by heating from a decolored state. A system to which an alkoxyphenol compound is applied (JP-A-11-129623 and JP-A-11-5973), a system to which a specific hydroxybenzoic acid ester is applied (JP-A-2001-105732), and further decolorization A system using a gallic acid ester or the like that develops a color at the maximum high-temperature side discoloration point (complete coloring temperature) by heating from a state can be applied.
Here, a coloring agent such as a non-thermochromic dye or pigment is blended into the reversible thermochromic microcapsules or the ink to change the color change from color (1) to color (2). A configuration can be provided.
[0017]
It is preferable that the microcapsule pigment has an average particle diameter in the range of 0.5 to 5.0 μm, preferably 1 to 4 μm. In a system having an average particle size of more than 5.0 μm, the outflow from the capillary gap is reduced, and in a system having an average particle size of 0.5 μm or less, it is difficult to exhibit high-density coloring.
[0018]
The reversible thermochromic microcapsule pigment can be blended in an amount of 2 to 50% by weight (preferably 3 to 40% by weight, more preferably 4 to 30% by weight) based on the total amount of the ink composition. If it is less than 2% by weight, the color density is insufficient, and if it exceeds 50% by weight, the ink outflow property is reduced and the writing property is impaired.
[0019]
As the form of the capsule in the reversible thermochromic microcapsule pigment of the present invention, a form having a circular cross section is not refused, but a form having a non-circular cross section is effective.
In the reversible thermochromic handwriting formed by writing, the microcapsule pigment is densely oriented and fixed with the long diameter side (maximum outer diameter side) in close contact with the surface to be written, and has a high density of coloring. In addition, the microcapsule pigment is delicately elastically deformed into a shape that relieves the external force due to external force due to rubbing of the handwriting by the friction body 1 and the like, and destruction of the wall film of the microcapsule is suppressed, and the thermochromic function is exhibited. It can be effectively expressed without any loss.
Here, the microcapsule pigment having a non-circular cross-sectional shape has an average maximum outer diameter in the range of 0.5 to 5.0 μm, and has a reversible thermochromic composition / wall film = 7/1 to 1 / 1 (weight ratio).
In the microcapsule pigments (including those having a circular cross-sectional shape), in a system in which the average value of the maximum outer diameter exceeds 5.0 μm, the outflow from the capillary gap is reduced. In a system having a value of 0.5 μm or less, it is difficult to exhibit high-density color development. Preferably, the average value of the maximum outer diameter is in the range of 1 to 4 μm, and the average particle diameter of the microcapsule [(maximum outer diameter + center Is preferably in the range of 1 to 3 μm.
When the ratio of the reversible thermochromic composition to the wall film is larger than the above range, the thickness of the wall film becomes too thin, causing a decrease in resistance to pressure and heat, and conversely, the reversible thermochromic composition of the wall film. When the ratio to is larger than the above range, a decrease in color density and sharpness at the time of color development is unavoidable, and preferably, the reversible thermochromic composition / wall film = 6/1 to 1/1 (weight ratio). .
[0020]
For the microencapsulation of the reversible thermochromic composition, known means such as an interfacial polymerization method, an interfacial polycondensation method, an in-situ polymerization method, and a coacervate method can be used. In order to obtain a microcapsule pigment in the range, it is effective to apply an interfacial polymerization method or an interfacial polycondensation method in which aggregation and coalescence hardly occur.
[0021]
Here, a coloring agent such as a non-thermochromic dye or a pigment is blended into the reversible thermochromic microcapsule pigment or the ink to change the color from (1) to (2). Is adopted.
As the dye, acid dyes, basic dyes, direct dyes, and fluorescent dyes can all be used.
Examples of pigments include inorganic pigments such as carbon black, ultramarine blue, and titanium dioxide pigments, azo pigments, phthalocyanine pigments, indigo pigments, thioindigo pigments, sullen pigments, quinacridone pigments, anthraquinone pigments, sulphone pigments, and diketopyrrolopyrroles. Organic pigments such as organic pigments, dioxazine pigments, perylene pigments, perinone pigments, and isoindolinone pigments, and fluorescent pigments can be exemplified.
[0022]
The reversible thermochromic ink 6 incorporated in the writing implement 2 of the present invention has a maximum high-temperature side discoloration point in the range of 25 to 65 ° C. and an average particle diameter in the range of 0.5 to 5 μm. It is effective to disperse the microcapsule pigment in an aqueous medium and blend a binder resin as necessary.
Specifically, a shear-thinning-based ink containing a shear-thinning substance or an aggregation-based ink in which a reversible thermochromic microcapsule pigment is suspended in a gently aggregated state with a water-soluble polymer coagulant is effective. . Furthermore, a specific gravity-controllable ink in which the reversible thermochromic microcapsule pigment is adjusted to have a specific gravity difference of 0.05 or less with the aqueous vehicle can be applied.
[0023]
The shear thinning substance may be a nonionic surfactant having an HLB value in the range of 8 to 12, xanthan gum, welan gum, or succinoglycan whose constituent monosaccharide is an organic acid-modified heteropolysaccharide of glucose and galactose (average molecular weight of about 1-8 million), guar gum, locust bean gum and derivatives thereof, hydroxyethyl cellulose, alginic acid alkyl esters, methacrylic acid alkyl esters as main components, polymers having a molecular weight of 100,000 to 150,000, glucomannan, agar and carrageenan Carbohydrates having a gelling ability extracted from seaweed, such as benzylidene sorbitol and benzylidene xylitol or derivatives thereof, and a crosslinkable acrylic acid polymer can be used alone or in combination. In particular, xanthan gum, succinoglycan, and a crosslinkable acrylic acid polymer have excellent storage stability.
[0024]
As the water-soluble polymer coagulant, a nonionic water-soluble polymer compound is suitably used.
Specific examples include polyvinylpyrrolidone, polyethylene oxide, water-soluble polysaccharides, and nonionic water-soluble cellulose derivatives. Among these, specific examples of the water-soluble polysaccharide include tragacanth gum, guar gum, pullulan, and cyclodextrin. Specific examples of the nonionic water-soluble cellulose derivative include methylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, hydroxyethylmethylcellulose, and hydroxyethylcellulose. Propylmethylcellulose and the like. In the reversible thermochromic aqueous ink composition of the present invention, any water-soluble polymer that exhibits a loose bridging effect between the microcapsule pigment particles can be used, and among them, the above-mentioned nonionic water-soluble cellulose can be used. The derivative acts most effectively on the reversible thermochromic aqueous ink composition of the present invention.
The polymer coagulant can be blended in an amount of 0.05 to 20% by weight based on the total amount of the ink composition.
[0025]
Further, as a humectant to suppress drying with the pen tip, glycerin, propylene glycol, ethylene glycol, diethylene glycol, glycols such as low molecular weight polyethylene glycol and their lower alkyl ethers, 2-pyrrolidone, N-vinylpyrrolidone, An appropriate amount such as urea can be blended.
The humectant can be blended in an amount of 5 to 40% by weight based on the total amount of the ink.
[0026]
Further, an appropriate amount of a binder resin may be added for the purpose of adjusting the stickiness and the viscosity of the handwriting. The binder resin is selected from a resin emulsion, an alkali-soluble resin, and a water-soluble resin.
Examples of the resin emulsion include polyacrylate, styrene-acrylic acid copolymer, polyvinyl acetate, ethylene-vinyl acetate copolymer, ethylene-vinyl chloride copolymer, methacrylic acid-maleic acid copolymer, ethylene- Aqueous dispersions such as methacrylic acid copolymers, α-olefin-maleic acid copolymers, polyesters, polyurethanes, and the like are mentioned. Examples of the alkali-soluble resin include styrene-maleic acid copolymers and ethylene-maleic acid copolymers. And a styrene-acrylic acid copolymer. Examples of the water-soluble resin include polyvinyl alcohol and polyvinyl butyral, and one or a mixture of two or more thereof can be used.
In addition, various conventional dispersants such as surfactants can be blended as required.
[0027]
When the ink composition of the present invention is used by filling it into a ballpoint pen, a higher fatty acid such as oleic acid, a nonionic surfactant having a long-chain alkyl group, a polyether-modified silicone oil, a thiophosphorous tri (alkoxycarbonylmethyl ester) ) And thiophosphorous acid triesters such as triphosphorous acid tri (alkoxycarbonylethyl ester); monoesters of polyoxyethylene alkyl ethers or polyoxyethylene alkylaryl ethers; polyoxyethylene alkyl ethers or polyoxyethylene alkyl aryl ethers It is preferable to add a lubricant such as a phosphoric diester or a metal salt, an ammonium salt, an amine salt or an alkanolamine salt thereof to impart an effect of preventing wear of the ball seat.
[0028]
The shear-thinning ink and the coagulation ink are filled in a general-purpose writing instrument 2 and put to practical use.
More specifically, the shear-thinning ink is filled in a shaft barrel 5 having a tip holding a ball rotatably holding a ball, and a viscous follower (liquid tap 7) is arranged at a rear portion. The thermochromic writing implement 2 in the form of a ballpoint pen can be configured. Further, in the coagulation-based ink, a large number of fibers are arranged in close contact with each other, and a fiber body in which a capillary is formed between adjacent fibers is used as a pen body 4, and a capillary is formed between adjacent fibers. The coagulated ink is impregnated into a marker assembled so that the rear end of the pen body 4 is connected to the front end of the ink occluder, and the thermochromic writing implement 2 in the form of a marker is obtained. Can be configured.
[0029]
BEST MODE FOR CARRYING OUT THE INVENTION
Examples are shown below, but the present invention is not limited to these examples.
Further, as the writing implement 2, a reversible thermochromic ink 6 is incorporated in a general-purpose writing implement 2 such as a ball-point pen, a felt-tip pen, a marking pen, and the like, and the friction implement 1 is provided. And a friction body 1 formed at the rear end of the shaft body 5 (see FIG. 4).
[0030]
【Example】
Examples will be described below. The parts in the examples are parts by weight.
[0031]
Example 1
0.09 parts of purple pigment [manufactured by Shin-Etsu Chemical Co., Ltd., trade name: KE-Color R2301], red pigment [manufactured by Shin-Etsu Chemical Co., Ltd., trade name: KE-Color X-93-942] 0.13 After kneading a silicone material (trade name: DY32-7040U, manufactured by Dow Corning Toray Silicone Co., Ltd.) to which a part was added, a red friction body 1 was obtained by molding the resulting mixture.
The friction body 1 was able to instantaneously change the color of the reversible thermochromic image printed on the paper surface by rubbing, and was not transferred to the paper surface.
[0032]
Example 2
Preparation of reversible thermochromic ink 6
A reversible thermochromic pigment (t) in which a thermochromic color memory composition is encapsulated in microcapsules ₁ : 2 ° C, t ₂ : 6 ° C, t ₃ : 37 ° C, t ₄ : 44 ° C, average particle size: 2.5 µm, reversible thermochromic composition / wall film = 2.6 / 1.0, changes color from dark green to colorless) 12.5 parts, thermochromic color memory Reversible thermochromic pigment (t ₁ : 3 ° C, t ₂ : 6 ° C, t ₃ : 38 ° C, t ₄ : 45 ° C, average particle size: 2.5 µm, reversible thermochromic composition / wall film = 2.6 / 1.0, changing color from blue to colorless) 5.5 parts, red dye [Eisen Hodogaya ( Co., Ltd., trade name: New Koksin, C.I. I. 16255] 0.25 part, xanthan gum (shear-thinning agent) 0.33 part, urea 10 parts, glycerin 10 parts, nonionic penetrating agent [manufactured by San Nopco Co., Ltd., trade name: Nopco SW-WET-366] 0.6 parts, modified silicone-based defoaming agent [manufactured by San Nopco Co., Ltd., trade name: Nopco 8034] 0.1 part, fungicide [Zeneca Co., Ltd., trade name: Proxel XL-2] A reversible thermochromic ink consisting of 1 part and 60.62 parts of water was prepared (FIG. 6).
[0033]
Production of writing implements
0.97 g of the above-mentioned ink (which was previously cooled to 2 ° C. or less to form a reversible thermochromic pigment and allowed to stand at room temperature) was suction-filled into a polypropylene pipe having an inner diameter of 4.4 mm, and a resin holder was placed therein. A 0.7 mm stainless steel ball was connected to a ball-point pen tip held at the tip via a pin.
Next, a viscoelastic ink backflow preventive body (liquid stopper 7) containing polybutene as a main component is filled from the rear part of the polypropylene pipe and assembled into the shaft cylinder 5, and the friction body 2 prepared in Example 1 is removed. A cap 3 fitted to the top with a pulling force of 10 N, an outer diameter D and an extension length L of L / D = 0.48 is attached, and then removed by centrifugation. Air-treatment was performed to obtain a shear-thinning type thermochromic ballpoint pen (FIG. 1).
When the ballpoint pen was used to write on the report paper, the handwriting was not erased by long-time writing or shorthand, and a clear thermochromic handwriting of black with stable density was obtained.
[0034]
Discoloration behavior of handwriting
The thermochromic handwriting written on the paper having normal permeability by the ballpoint pen is in a black color developing state at room temperature (25 ° C.). When the hand is rubbed several times with the friction body 1, the rubbed portion immediately changes color. It turned red and this state could be maintained at room temperature. Next, when the thermochromic handwriting was left in a freezer (about -15 ° C.), the decolored portion was colored black again and returned to the state before rubbing. This discoloration behavior could be reproduced repeatedly.
[0035]
Example 3
Preparation of reversible thermochromic ink 6
Heat decoloring type reversible thermochromic microcapsule pigment (t ₁ : 35 ° C, t ₂ : 38 ° C, t ₃ : 37 ° C, t ₄ : 40 ° C, average particle size: 2.5 µm, reversible thermochromic composition / wall film = 2.6 / 1.0, color change from blue to colorless) 44.00 parts (solid content 13) .2%) with 0.50 parts of a pink dye (trade name: Erythrosin (CI No. 45430), manufactured by Eisen Hodogaya Co., Ltd.), 5.00 parts of glycerin, a fungicide, [Zeneca ( Co., Ltd., trade name: Proxel XL-2] 0.70 part, silicone antifoaming agent, [San Nopco Co., Ltd., trade name: SN Deformer 381] 0.1 part, and water 41.70 parts. An aqueous solution containing 5.00% by weight of a water-soluble polymer flocculant (hydroxyethyl cellulose) [manufactured by Union Carbide Japan Co., Ltd., trade name: Cellosize WP-09L] after being uniformly dispersed in an aqueous medium. While stirring 00 parts It was added in the liquid in the serial dispersed state, and the reversible thermochromic ink 6 suspension of the reversible thermal discoloration microcapsule pigment gradual aggregation state was prepared.
[0036]
Production of writing implement 2
The fiber reversible thermochromic ink 6 was impregnated into a fiber sizing ink occlusion body (porosity of about 80%) in which a polyester sliver was covered with a synthetic resin film immediately after being stirred in a uniform state, and was obtained in Example 1. The friction body 1 is formed into a convex curved surface having a radius of curvature of 4.0 mm, and is accommodated in a shaft body 5 formed at a rear end portion with an outer diameter D and an extension length L of L / D = 0.63. Was assembled in contact with the resin-processed pen body 4 (porosity of about 50%) of polyester fiber attached to the tip of the above to form an aqueous marker.
When writing was performed on report paper using the water-based marker, the handwriting did not change color even after prolonged writing or shorthand, and a clear purple handwriting having a stable color tone was obtained.
[0037]
Discoloration behavior of handwriting
The handwriting written on the paper having normal permeability by the aqueous marker is in a purple discolored state at room temperature (25 ° C.). It changed color. Further, when the container was left at room temperature in this discolored state, the pink portion was discolored again to purple and returned to the state before rubbing. The discoloration behavior could be reproduced repeatedly.
[0038]
【The invention's effect】
The friction body of the present invention and the writing instrument provided with the friction body according to claim 1, which can easily change color without rubbing the thermochromic image many times, and repeatedly and reversibly change color without peeling the thermochromic image. obtain. In addition, it can be rubbed smoothly and can be used without staining the area around the rubbed portion with shavings.
[0039]
According to the second aspect, a friction body rich in design can be formed.
[0040]
In the third aspect, the frictional body is colored vividly, and the thermochromic image and the thermochromic image can be discolored without color transfer to the peripheral portion at the time of rubbing.
[0041]
According to the fourth aspect, the user can freely form an image, and the color of the image can be easily changed using a friction body attached or attached.
[0042]
In the fifth aspect, the thermochromic image formed by the user can be easily changed in color without being rubbed many times, and the thermochromic image can be repeatedly and reversibly changed without peeling. In addition, it can be rubbed smoothly and can be used without staining the area around the rubbed portion with shavings.
[0043]
According to the sixth aspect, it is possible to form a friction body having a good design property, to unify the design of the writing implement appearance, and to easily inform the user of the ink color in the writing implement.
[0044]
According to the seventh aspect, the friction body is colored vividly, and the handwriting can be discolored without transferring color to the handwriting and its peripheral portion at the time of rubbing.
[0045]
In claim 8, the handwriting can be rubbed with an appropriate softness without peeling. In addition, a constant contact area can be obtained regardless of the contact angle with the handwriting, and only the target portion can be rubbed without rubbing over a wide area, the abrasion of the friction body itself can be reduced, and the heat generation efficiency can be increased. Therefore, the portion to be discolored can be accurately and easily discolored without shavings.
[0046]
In the ninth aspect, the handwriting having a small width formed by the writing instrument can be accurately and easily discolored.
[0047]
According to the tenth aspect, wobbling and falling off of the friction body at the time of rubbing can be prevented, and poor rubbing does not occur.
[0048]
In the eleventh aspect, the friction body cannot be easily removed from the writing instrument, and accidental ingestion of an infant or the like can be prevented.
[0049]
According to the twelfth aspect of the present invention, the friction body does not wobble or fall off when rubbed, and does not easily come off when pulled, so that the applicability as a product is high.
[0050]
According to the thirteenth aspect, the ink has a high-density color-forming property, and provides a writing implement that reliably changes color by rubbing.
[0051]
According to the fourteenth aspect, it is possible to form a highly magical image which is reversibly discolored by heating and cooling, and can be applied and developed in various ways such as learning, training, and toy elements according to the purpose.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view showing an embodiment of a writing instrument provided with a friction body of the present invention.
FIG. 2 is an enlarged view of a main part of FIG.
FIG. 3 is a sectional view taken along line AA of FIG. 2;
FIG. 4 is an explanatory view showing one embodiment of a writing instrument provided with the friction body of the present invention.
FIG. 5 is an explanatory diagram showing the color change behavior of a heat decoloring type thermochromic ink.
FIG. 6 is an explanatory diagram showing a color change behavior of a color memory holding type thermochromic ink.
[Explanation of symbols]
1 Friction body
11 rubbing part
2 Writing implements
3 caps
31 Fitting part
32 ribs
4 Pen body
5 shaft barrel
6 Thermochromic ink
7 liquid stopper
8 Refill
t ₁ Complete coloring temperature of heat-decolorable thermochromic ink and color-memory-preserving thermochromic ink (minimum low-temperature discoloration point)
t ₂ Color development start temperature of heat-decolorable thermochromic ink and color-memory-preserving thermochromic ink
t ₃ Decoloring start temperature of heat-decolorable thermochromic ink and color-memory retaining thermochromic ink
t ₄ Complete decoloration temperature of heat-decolorable thermochromic ink and color-memory-preserving thermochromic ink (maximum high-temperature color change point)

Claims (14)

A friction member having elasticity for discoloring an image formed using a reversible thermochromic ink from a first state to a second state by frictional heat, wherein the friction member is made of silicone rubber. The friction body according to claim 1, wherein the friction body contains a coloring agent. The friction body according to claim 2, wherein the colorant is contained in an amount of 0.1 to 1.0% by weight based on the total amount of the friction body. A writing implement including at least a reversible thermochromic ink, wherein the writing implement includes a frictional body having elasticity to change a handwriting formed by the writing implement from a first state to a second state by frictional heat. The writing implement according to claim 4, wherein the friction body is made of silicone rubber. The writing implement according to claim 4, wherein the friction body contains a coloring agent. The writing implement according to claim 6, wherein the coloring agent is contained in an amount of 0.1 to 1.0% by weight based on the total amount of the friction body. The writing implement according to claim 4, wherein the rubbing part of the friction body has a convex curved shape. The writing implement according to claim 8, wherein a radius of curvature R of the convex curved surface is 1 mm to 10 mm. The writing instrument according to claim 4, wherein an outer diameter D and an extension length L of the friction body satisfy L <D. The writing instrument according to claim 4, wherein the frictional member has a detachment force of 10N or more. 5. The writing instrument according to claim 4, wherein the friction body satisfies L <D between an outer diameter D and an extension length L and has a pulling force of 10 N or more. 6. The writing implement provided with a friction body according to claim 4, wherein the reversible thermochromic ink contains a microcapsule pigment having a maximum high-temperature side color change point in a range of at least 25C to 65C. The reversible thermochromic ink is a heat-erasing type in which the color is erased by heating from a color-developing state, a color-memory-holding type that alternately stores and retains a color-developing state or a decoloring state in a specific temperature range, or from a decoloring state. 14. The friction body and the friction body according to claim 1, wherein the friction body is selected from any one of a heating and coloring type in which a color is formed by heating and the color is restored to a decolored state by cooling from the color development state. Writing implement.

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