JP2010253842A - Thermally discoloring writing instrument - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a writing instrument equipped with a special hand writing performance and an excellent decorating property and having a high novelty effect, by which internally contained ink does not carelessly decolor by direct rays even when the thermally discoloring ink which decolors in a living temperature region is contained in the writing instrument, even when the exterior has a decoration by a film transfer, and reproducibility of the tone of a transferred image can be obtained without using a white solid layer. <P>SOLUTION: As for this thermal discoloring writing instrument 1 containing the ink 4 which can be decolored or discolored by heating, the brightness value of the exterior 6 of the writing instrument is 6.3 or higher, and at the same time, a transfer layer 9 formed by the film transfer is laminated on the surface of the exterior. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a thermochromic writing instrument. More specifically, the present invention relates to a thermochromic writing instrument having an exterior with a high decorative effect that can be decolored or discolored by heating the handwriting.

Conventionally, direct printing by pad printing or the like, thermal transfer printing using a transfer film, or the like has been used as a means for decorating a writing instrument or putting a name (for example, see Patent Document 1).
Printing by the transfer film has been widely used in recent years because it can form delicate colors and images in a large area compared to direct printing and can easily print on a curved surface. In general, when a photograph or a pattern is formed on a transfer film, a technique such as gravure printing is used. However, in this technique, it is necessary to prepare a printing plate, and special printing techniques such as color change and alignment are required. Required. For this reason, it takes time and cost to produce the film, and it is not suitable for adapting to a small-lot, multi-product product such as name insertion corresponding to customer needs.

Therefore, on-demand printing has been attracting attention as a printing technology that can be applied to small-lot, multi-product products and does not require a printing plate, and a transfer film by a printing method such as an inkjet method or an electrophotographic method using toner. Is produced (see, for example, Patent Document 2).
Since the on-demand printing does not require printing plate preparation or specialized printing technology, it can quickly produce a transfer film designed with desired photos, designs, letters, etc. in response to customer needs. However, ink and toner used for on-demand printing are generally limited to the three basic colors (yellow, cyan, magenta) and black. For this reason, when the color of the material to be transferred (writing instrument exterior) is a dark color, the design is erased to the background color and the color tone reproducibility is deteriorated. In order to solve this problem, a white solid layer is required, but application in a separate process is required due to restrictions on the printer head, which requires more specialized printing technology and takes time and cost. End up.

Apart from this, a marking pen containing thermochromic ink is disclosed as a writing instrument that can be decorated as described above (see, for example, Patent Document 3).
Since the writing instrument contains ink that discolors at temperatures above body temperature, the shaft tube (exterior member) is heated and left inside the shaft tube when left in a place where it is exposed to direct sunlight during storage. The temperature of the space (the portion where the thermochromic ink is accommodated) rises and the ink tends to be decolored. In particular, when the shaft tube is colored in a dark color such as black or blue (that is, a color with high brightness), the shaft tube absorbs sunlight and the inside is heated to a high temperature in a short time. There is a case where the color is easily erased and the handwriting cannot be visually recognized at the time of writing.

Japanese Utility Model Publication No. 7-12289 JP 2000-141992 Japanese Utility Model Publication No. 2-30425

  The present invention contains a thermochromic ink that is erased in the living temperature range in a writing instrument, and even if the exterior decorated with film transfer is used, the built-in ink is unintentionally erased by direct sunlight. The present invention provides a writing instrument with a high novelty effect, which has special handwriting performance and excellent decorativeness, which can obtain the reproducibility of the color tone of a transferred image without using a white solid layer.

The present invention is a thermochromic writing instrument that contains ink that can be decolored or discolored by heating. The writing instrument exterior has a brightness value of 6.3 or more, and a transfer layer formed by film transfer is laminated on the exterior surface. It is a requirement that
Furthermore, the transfer layer is laminated using a transfer film imaged by an on-demand printing method, the transfer film is imaged by an ink jet method, and the ink is Including a reversible thermochromic composition comprising at least a donating color-forming organic compound, (b) an electron-accepting compound, and (c) a reaction medium for controlling the color reaction of (i) and (b) above. And a microcapsule pigment that changes color from colorless to colorless by heating, the microcapsule pigment exhibits a large hysteresis characteristic with respect to a color density-temperature curve, exhibits a tautomerism between a colored state and a colorless state, holding the temperature range which can coexist are pigments in the normal temperature range, the pigment is the process of temperature increase from the colored state, begins decolorized to reach the temperature T _3, the temperature T ₃ Become completely colorless state at a temperature T ₄ or more temperature region Ri in the course of the temperature is lowered from colorless state, said temperature T ₃ begins to coloration from reaching the lower temperature T _2, a temperature lower than the temperature T ₂ T ₁ become completely colored state at a temperature range, it shows a hysteresis characteristic which can hold the colored state or a colorless state at a temperature range between the temperature T ₂ and the temperature T _3, temperatures T ₁ in the range of -30～10 ° C. There, the temperature T ₄ is in the range of 30 to 80 ° C., the writing instrument is a requirement to become comprises a rubbing member.

  According to the present invention, even when a writing instrument exterior that contains a thermochromic ink that is decolored in a living temperature range is decorated by film transfer, the ink that is accommodated by direct sunlight is not inadvertently erased. In addition, reproducibility of the color tone of the transferred image can be obtained without using a white solid layer on the image of the transfer film. Therefore, it is particularly useful for transfer films imaged by the on-demand printing method, and can be applied to small-lot, high-variety products. The writing instrument has a high novelty effect with special handwriting performance and excellent decorativeness. It becomes.

It is a graph explaining the hysteresis characteristic in the color density-temperature curve of the reversible thermochromic composition used for this invention. It is a longitudinal section explanatory view showing an example of the thermochromic writing instrument of the present invention. FIG. 3 is an enlarged view of a main part of a transfer portion in FIG. 2.

The thermochromic writing instrument of the present invention contains ink that can be decolored or discolored by heating, and a transfer layer by film transfer is laminated on the exterior surface.
If the writing instrument has an exterior with a brightness value of 6.3 or more (upper limit is 10.0), a marking pen or ballpoint pen using an exterior made of a material such as resin or metal, and a fountain pen, etc. A general-purpose writing instrument can be applied. Note that the writing instrument exterior is the part that constitutes the outer surface of the writing instrument such as a shaft cylinder or cap, and is used directly as the outermost surface. A double cylinder type shaft cylinder covering the inner cylinder in which the layers are formed is also included.
In order to obtain the lightness value, a coloring material such as a color pigment or titanium oxide is added to the resin for molding, and means such as coating or film sticking on the surface of a resin molded product or metal workpiece are used. In particular, the one formed by adding titanium oxide in the resin can improve the hiding property (internal impermeability) of the writing instrument exterior without post-processing such as painting, and the metallic pigment in the molding resin. It is preferable because the generation of a weld line when adding a pigment having a large particle size such as can be suppressed and the entire exterior can be visually recognized uniformly.
When the brightness value is smaller than 6.3, the heat storage property of the writing instrument exterior due to sunlight irradiation increases, so that ink decoloration easily occurs due to the temperature rise in the internal space, and the contrast between the image layer and the color tone of the background is unclear. Therefore, the reproducibility of the image color tone is deteriorated.

  As the marking pen, for example, a pen tip for a marking pen such as a fiber tip, a felt tip, a plastic tip, etc. is attached to the writing tip, and an ink occlusion body made of a fiber bundle housed inside the shaft tube is impregnated with ink, Structure that supplies ink to the writing tip, ink is stored directly inside the shaft tube, and a predetermined amount of ink is applied to the writing tip by interposing an ink flow rate adjusting member made of comb grooves and fiber bundles Examples include a structure for supplying ink, a marking pen for storing ink directly inside the shaft cylinder, and a structure for supplying a predetermined amount of ink to the writing tip by a valve mechanism.

  The ballpoint pen has, for example, an ink containing tube filled with an ink composition in a shaft cylinder, and the ink containing tube communicates with a chip having a ball attached to the tip, and further, an ink backflow is provided on the ink end surface. The structure in which the prevention body is in close contact, the tip is connected to the tip of the shaft cylinder, the ink composition is directly filled in the shaft cylinder, and the structure in which the ink backflow prevention body is in close contact with the end face of the ink is accommodated in the shaft cylinder. A structure that supplies ink to the chip by impregnating the ink occlusion body made of a fiber bundle and supplies the ink to the chip, and a predetermined amount of ink is supplied to the chip via a comb groove-shaped ink flow rate adjustment member and an ink flow rate adjustment member made of a fiber bundle. For example, a ballpoint pen having a structure as described above can be used. Further, the ballpoint pen having a structure in which the tip is connected to the tip of the shaft cylinder and directly filled with ink may have a structure in which the transfer layer is formed on the exterior filled with ink and then accommodated in the transparent outer shaft.

  As the ballpoint pen member, the ballpoint pen tip is a tip formed by holding a ball in a ball holding portion in which the vicinity of the tip of a metal pipe is pressed and deformed inward from the outer surface, or a metal material is cut by a drill or the like A chip that holds a ball in a ball holding part formed by processing, or a ball that is held by a chip formed by cutting a metal pipe or metal material, and is biased forward by a spring body Etc. can be applied. Further, cemented carbide, stainless steel, ruby, ceramic or the like can be applied to the balls used for the chips.

As the ink containing tube, a molded body made of a thermoplastic resin such as polyethylene, polypropylene, polyethylene terephthalate is preferably used, and a transparent, colored transparent, or translucent molded body can be confirmed because the ink color, ink remaining amount, etc. can be confirmed. Is preferred.
When the ink storage tube is used, the back end of the ink to be stored is filled with an ink backflow prevention body. The ink backflow preventer can be either liquid or solid, and the liquid ink backflow preventive includes non-volatile media such as polybutene and silicone oil. Aluminum silicate or the like can also be added. In addition, examples of the solid ink backflow preventive body include resin molded products, and the liquid and solid ink backflow preventive bodies can be used in combination.

The marking pen, ballpoint pen, and fountain pen have a cap type with a cap that covers the nib (tip), as well as a knock type, rotary type, slide type, etc., and a pen tip is accommodated in the shaft cylinder. Possible intrusive form is also possible. In the case of the form of appearance, it is possible to adopt not only a type in which one refill is accommodated, but also a duplex type in which two or more refills are accommodated and a desired refill can be selectively emerged.
Alternatively, a double-headed form may be used in which different types of pen nibs are attached, or pen nibs that lead out different colors of ink are attached.

Conventionally used inks that can be decolored or discolored by heating are contained in the writing instrument, and in particular, as the colorant blended in the ink, (i) an electron-donating color-forming organic material. A pigment encapsulating in a microcapsule a reversible thermochromic composition comprising at least three essential components of a compound, (b) an electron-accepting compound, and (c) a reaction medium that determines the temperature at which the color reaction of both occurs. It is valid.
Among the reversible thermochromic compositions, the compositions that can be decolored by heating are described in JP-B-51-44706, JP-B-51-44707, JP-B-1-29398, and the like. The color changes before and after the temperature (discoloration point), shows a decolored state in the temperature range above the high temperature side discoloration point, and develops a color state in the temperature range below the low temperature side discoloration point. There is only one specific state, and the other state is maintained while the heat or cold required to develop that state is applied, but if the heat or cold is no longer applied, The composition which has the characteristic ((DELTA) H = 1-7 degreeC) with a comparatively small hysteresis width | variety which returns to the state exhibited in a region can be illustrated.
In addition, large hysteresis characteristics described in JP-B-4-17154, JP-A-7-179777, JP-A-7-33997, JP-A-8-39936, JP-A-2005-1369, and the like. (ΔH = 8 to 70 ° C.), and the shape of the curve plotting the change in color density due to the temperature change is from the higher temperature side than the color change temperature range, contrary to the case where the temperature is raised from the lower temperature side than the color change temperature range. Use a reversible thermochromic composition that changes color by following a path that differs greatly from that of lowering, and can store and retain the color development state in the low temperature range or the decoloration state in the high temperature range in the specific temperature range. You can also.

The hysteresis characteristic in the color density-temperature curve of the composition will be described in detail.
In FIG. 1, the vertical axis represents color density and the horizontal axis represents temperature. The change in color density due to the temperature change proceeds along the arrow. Here, A is a point indicating the density at the lowest temperature T ₄ (hereinafter referred to as the complete color erasing temperature) reaching the complete color erasing state, and B is the maximum temperature T ₃ (hereinafter referred to as the color erasing) capable of maintaining the complete color development state. C is a point indicating the density at the lowest temperature T ₂ (hereinafter referred to as a color development start temperature) at which a completely decolored state can be maintained, and D reaches a complete color development state. This is a point indicating the density at the maximum temperature T ₁ (hereinafter referred to as a complete color development temperature).
Discoloration temperature region is a temperature region between the T ₁ and T _4, the first hue and can co-exist two phases of the second color, the temperature range between T ₂ and T ₃ is a large area of the difference in color density Is a substantial discoloration temperature range (two-phase holding temperature range).
The length of the line segment EF is a scale indicating the discoloration contrast, and the length of the line segment HG passing through the midpoint of the line segment EF is a temperature width indicating the degree of hysteresis (hereinafter referred to as hysteresis width ΔH). If this ΔH value is small, only one specific state can exist in the normal temperature range among both states before and after the color change. Further, when the ΔH value is large, it is easy to maintain each state before and after the color change.

By using a reversible thermochromic composition having a color memory property among the above-described compositions, the color can be easily changed from the first state (colored) to the second state (colorless). And different colors can be seen interchangeably.
Specifically, the complete color development temperature T ₁ is a temperature that can be obtained only in a freezing room, a cold district, etc., that is, −30 to 10 ° C., preferably −30 to 0 ° C., more preferably −30 to −10 ° C., and , complete decoloring temperature _{T 4} frictional heat generated by friction body, the temperature obtained from the hair dryer familiar heating body, i.e. 30 to 80 ° C., preferably 50 to 80 ° C., and more preferably specific in the range of 60-80 ° C. However, by specifying the ΔH value at 40 to 60 ° C., it is possible to effectively function to maintain the color exhibited in the normal state (daily life temperature range).
The writing instrument applied in the present invention contains an ink containing a microcapsule pigment encapsulating a reversible thermochromic composition in a colored state, and the handwriting formed by the writing instrument can be easily erased by touch or the like. It is preferable that the configuration is not performed, and it is preferable that the erased handwriting does not appear again. Therefore, the above-described temperature setting of T ₁ and T ₄ is an extremely important requirement.

  Among the above-mentioned components, as the component (a), that is, the electron donating color-forming organic compound, conventionally known diphenylmethane phthalides, phenyl indolyl phthalides, indolyl phthalides, diphenyl methane azaphthalides, Phenylindolyl azaphthalides, fluorans, stylinoquinolines, diazarhodamine lactones and the like can be mentioned.

As the electron-accepting compound of component (b), a group of compounds having active protons, a group of pseudo-acidic compounds (a group of compounds that are not acids but act as an acid in the composition and cause component (a) to develop color), electrons There is a group of compounds having pores.
Examples of compounds having active protons include monophenols to polyphenols as compounds having phenolic hydroxyl groups, and alkyl groups, aryl groups, acyl groups, alkoxycarbonyl groups, carboxy groups and esters thereof as substituents. Or what has an amide group, a halogen group, etc., phenol-aldehyde condensation resin etc., such as a bis type and a tris type phenol, are mentioned. Moreover, the metal salt of the compound which has the said phenolic hydroxyl group may be sufficient.

Examples of the reaction medium (c) for reversibly causing the electron transfer reaction by the components (a) and (b) in a specific temperature range include alcohols, esters, ketones, ethers, and acid amides. It is done.
The component (c) is preferably a large hysteresis characteristic regarding the color density-temperature curve (a curve plotting a change in color density due to a temperature change changes the temperature from the low temperature side to the high temperature side and the high temperature side to the low temperature side). A carboxylic acid ester compound that exhibits a ΔT value (melting point-cloud point) of 5 ° C. or higher and lower than 50 ° C., which can form a reversible thermochromic composition that exhibits color memory, and changes color when changing to the side) For example, a carboxylic acid ester having a substituted aromatic ring in the molecule, an ester of a carboxylic acid having an unsubstituted aromatic ring and an aliphatic alcohol having 10 or more carbon atoms, a carboxylic acid ester having a cyclohexyl group in the molecule, 6 carbon atoms Fatty acid and unsubstituted aromatic alcohol or phenol ester, fatty acid having 8 or more carbon atoms and branched aliphatic alcohol or ester, dicarboxylic acid And esters of aromatic alcohols or branched aliphatic alcohols, dibenzyl cinnamate, heptyl stearate, didecyl adipate, dilauryl adipate, dimyristyl adipate, dicetyl adipate, distearyl adipate, trilaurin, trimyristin, tristearin, Dimyristin, distearin and the like are used. More preferably, compounds described in JP-A-2006-137886 and JP-A-2006-188660 are used as the component (c).

  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, a coacervate method, etc. can be applied. Application of a polymerization method or an interfacial polycondensation method is effective.

As the reversible thermochromic ink applied in the present application, an ink in which a microcapsule pigment showing a colored state is dispersed in a vehicle is effective, and the vehicle is preferably an aqueous vehicle, but may be an oil vehicle.
Specific water-based inks include a shear-thinning ink containing a shear-thinning agent and an aggregating ink in which a reversibly thermochromic microcapsule pigment is suspended in a loosely aggregated state with a water-soluble polymer flocculant. It is done. Furthermore, there is an ink in which the specific gravity difference between the reversible thermochromic pigment and the vehicle is adjusted to 0.05 or less.

By adding the shear thinning agent, it is possible to suppress the aggregation / sedimentation of the microcapsule pigment and to suppress the bleeding of the handwriting. Even if writing on the material, good handwriting can be formed without bleeding.
Furthermore, when the writing instrument to be filled with the ink is in the form of a ballpoint pen, it prevents ink leakage from the gap between the ball and the tip when not in use, or the ink when the writing tip is left upward (upright state). Backflow can be prevented.

  Examples of the shear thinning agent include xanthan gum, welan gum, succinoglycan (average molecular weight of about 1 to 8 million) whose constituent monosaccharide is an organic acid-modified heteropolysaccharide of glucose and galactose, guar gum, locust bean gum and derivatives thereof , Hydroxyethyl cellulose, alginic acid alkyl esters, polymers having a molecular weight of 100,000 to 150,000, mainly composed of alkyl esters of methacrylic acid, thickening agent having gelling ability extracted from seaweed such as glucomannan, agar and carrageenan Sugars, benzylidene sorbitol and benzylidene xylitol or their derivatives, crosslinkable acrylic acid polymer, inorganic fine particles, polyglycerin fatty acid ester, polyoxyethylene sorbitan fatty acid ester, polyethylene glycol fatty acid ester, polio Shi polyoxyethylene alkyl ether-polyoxypropylene alkyl ethers, polyoxyethylene alkyl phenyl ether, nonionic HLB value, such as fatty acid amide is 8-12 surfactants, salts of dialkyl or dialkenyl sulfosuccinic acid. Examples thereof include a mixture of N-alkyl-2-pyrrolidone and an anionic surfactant, and a mixture of polyvinyl alcohol and an acrylic resin.

As the water-soluble polymer flocculant, nonionic water-soluble polymer compounds are preferably used, and specific examples include polyvinylpyrrolidone, polyethylene oxide, water-soluble polysaccharides, and nonionic water-soluble cellulose derivatives. . Among these, specific examples of water-soluble polysaccharides include tragacanth gum, guar gum, pullulan, cyclodextrin, and specific examples of nonionic water-soluble cellulose derivatives include methylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, hydroxyethylmethylcellulose, hydroxy Examples thereof include propylmethylcellulose.
Any water-soluble polymer flocculant can be applied as long as it is a water-soluble polymer that exhibits a gentle bridging action between pigment particles in the ink, but a nonionic water-soluble cellulose derivative works most effectively.

In addition, general-purpose water-soluble organic solvents, lubricants such as higher fatty acids, nonionic surfactants, polyether-modified silicone oils and phosphate esters, and resins such as acrylic resins and polyvinylpyrrolidone are added as necessary. Thus, it is possible to impart adhesion to the paper surface and viscosity.
In addition, pH adjusters such as inorganic salts such as sodium carbonate, sodium phosphate and sodium acetate, organic basic compounds such as water-soluble amine compounds, benzotriazole, tolyltriazole, dicyclohexylammonium nitrite, diisopropylammonium nitrite, saponin, etc. Rust preventive agent, coalic acid, sodium salt of 1,2-benzthiazolin-3-one, sodium benzoate, sodium dehydroacetate, potassium sorbate, propyl paraoxybenzoate, 2,3,5,6-tetrachloro-4- (Methylsulfonyl) pyridine and other preservatives or antifungal agents, urea, nonionic surfactants, reduced or non-reduced starch hydrolysates, oligosaccharides such as trehalose, sucrose, cyclodextrin, glucose, dextrin, sorbit, man Knit, Pi Wetting agents such as phosphoric acid sodium, defoamers, dispersing agents, a surfactant may be added a fluorine-based surfactant or a nonionic improve the ink permeability.
Furthermore, a color-changing ink can be constituted by adding a general-purpose non-color-changing colorant.

The handwriting formed with the thermochromic ink can be changed in color from a colored state to a colorless state by applying a heating means such as scratching with a finger or a heating tool, but it is easy to write and erase with one writing tool. And in order to perform reliably, it is preferable to provide a scraping member (friction body) in a writing instrument.
As the rubbing member, an elastic body such as an elastomer or plastic foam which is rich in elasticity and can generate frictional heat by rubbing at the time of rubbing is preferable, but a plastic molded body, stone material, wood, Metals and fabrics may be used.
Although it is possible to scrape the handwriting by using an eraser, it is preferable to use a rubbing member as described above because erase scraps are generated at the time of rubbing.
As the material of the rubbing member, silicone resin, SBS resin (styrene-butadiene-styrene copolymer), SEBS resin (styrene-ethylene-butylene-styrene block copolymer), etc. are preferably used. SBS resin or SEBS resin is more preferably used because the resin tends to adhere to the parts erased by rubbing and the handwriting may be repelled when writing repeatedly. Further, as the scraping member, a member having a Shore hardness A of 55 degrees or more in JIS K6253A is more preferable.

The transfer layer laminated on the outer surface of the writing instrument (the surface visible from the outside of the shaft cylinder or cap) is a general-purpose transfer such as thermal transfer using a transfer film on which images such as photographs, designs and characters are formed ( Printing) method.
Printing by the transfer film is useful as a decorative means with high decorativeness because it can form delicate colors and images in a large area compared to direct printing and can easily print on a curved surface.
As an image forming method on the transfer film, a method using a printing plate such as general gravure printing may be used, but a printing plate that can be applied to a small lot and various types of products such as engraving is used. An on-demand printing method that can be performed without using the printer is preferable.
Specific examples of the on-demand printing method include an inkjet method, an electrophotographic method (a method using a wet or dry toner), a thermal melting type or a dye sublimation type thermal transfer method, a magnetic head recording, or a magneto for magnetic recording. Examples of the printing method include a graphic method. Among these, the ink jet method and the toner method are preferable, and the ink jet method is most suitable because the image forming property is particularly high and the manufacturing cost is low.

As the colorant used in the ink jet method and the toner method, organic pigments and inorganic pigments applicable to general three basic colors (yellow, cyan, magenta) and black, and dyes can be used.
As the black colorant, for example, an inorganic colorant such as carbon black or iron trioxide, or an organic colorant such as cyanine black can be used.

As the yellow colorant, inorganic pigments such as chrome lead, cadmium yellow, yellow iron oxide, titanium yellow, and ocher can be used. Further, hardly soluble metal salts (azo lakes) such as acetoacetate allylide monoazo pigments, acetoacetate allylide disazo pigments, condensed azo pigments, benzimidazolone monoazo pigments, and isoindolinone pigments can be used.
Furthermore, selenium pigments, azo nickel complex pigments, nitroso nickel complex pigments, metal complex pigments such as azomethine copper complex pigments, phthalimidoquinophthalone pigments that are quinophthalone pigments, and the like can be used.

As the magenta colorant, inorganic pigments such as cadmium red, bengara, silver vermilion, red lead, and antimony vermilion can be used.
In addition to azo lake pigments and insoluble azo pigments (monoazo, disazo, and condensed azo pigments), anthraquinone pigments, thioindigo pigments, perinone pigments, perylene pigments, quinacridone pigments, pyrocholine pigments, red Condensed polycyclic pigments such as fluorvin pigments can be used.

  As the cyan colorant, inorganic pigments such as ultramarine blue, bitumen, cobalt blue and cerulean blue can be used. Also, phthalocyanine pigments, selenium pigments, basic dye lake pigments, and the like can be used.

In addition, it is also possible to use a luster pigment or a mat pigment as necessary.
Examples of the luster pigment include pearl pigments such as scaly foil pieces (titanium dioxide-coated mica) obtained by baking titanium oxide or iron oxide on the inner part of shells, ground pearls, mica fine particles, aluminum, Examples thereof include metal powders such as brass, bronze, gold and silver.
Examples of the matte pigment include clay minerals such as kaolinite, halosite, muscovite, and talc, and synthetic achromatic pigments such as anhydrous silica, anhydrous alumina, calcium carbonate, magnesium carbonate, and barium carbonate.

  As the dye, water-soluble direct dyes, acid dyes, basic dyes, food dyes, reactive dyes, water-insoluble oil-soluble dyes, and disperse dyes can be used in the form of being dispersed or dissolved in a solvent.

  Examples of the water-soluble dye include C.I. I. Acid Yellow 17, 23, 42, 44, 79, 142, C.I. I. Acid Red 1, 8, 13, 14, 18, 26, 27, 35, 37, 42, 52, 82, 87, 89, 92, 97, 106, 111, 114, 115, 134, 186, 249, 254, 289 , C.I. I. Acid Blue 9, 29, 45, 92, 249, C.I. I. Acid Black 1, 2, 7, 24, 26, 94, C.I. I. Food Yellow 3, 4, C.I. I. Food Red 7, 9, 14, C.I. I. Food Black 2, C.I. I. Direct yellow 1, 12, 24, 26, 33, 44, 50, 142, 144, 86, C.I. I. Direct Red 1, 4, 9, 13, 17, 20, 28, 31, 39, 80, 81, 83, 89, 225, 227, C.I. I. Direct Orange 26, 29, 62, 102, C.I. I. Direct Blue 1, 2, 6, 15, 22, 25, 71, 76, 79, 86, 87, 90, 98, 163, 165, 199, 202, C.I. I. Direct plaques 19, 22, 32, 38, 51, 56, 71, 74, 75, 77, 154, 168, C.I. I. Basic Yellow 1, 2, 11, 13, 14, 15, 19, 21, 23, 24, 25, 28, 29, 32, 36, 40, 41, 45, 49, 51, 53, 63, 65, 67, 70, 73, 77, 87, 91, C.I. I. Basic Red 1, 2, 12, 13, 14, 15, 18, 22, 23, 24, 27, 29, 35, 36, 38, 39, 46, 49, 51, 52, 54, 59, 68, 69, 70, 73, 78, 82, 102, 14, 109, 112, C.I. I. Basic blue 1,3,5,7,9,21,22,26,35,41,45,47,54,62,65,66,67,69,75,77,78,89,92, 93, 105, 117, 120, 122, 124, 129, 137, 141, 147, 155, C.I. I. A dye indicated by a color index such as Basic Black 2 or 8 is used.

  Examples of water-insoluble dyes include diarylmethane, triarylmethane, thiazole, methine, azomethine, xanthine, oxazine, azo and azo derivatives, anthraquinone derivatives, quinophthalone derivatives, spirodipyrans, Isodolinosviropyran and fluoran dyes are preferably used. Specifically, the C.I. I. Disperse Yellow 51, 3, 54, 79, 60, 23, 7, 141, C.I. I. Day Sparse Blue 24, 56, 14, 301, 334, 165, 19, 72, 87, 287, 154, 26, 359, C.I. I. Disper thread 135,146,59,1,73,60,167, C.I. I. Disperse violet 4, 13, 26, 36, 56, 31, C.I. I. Solvent Violet 13, C.I. I. Solvent Black 3, C.I. I. Solvent Green 3, C.I. I. Solvent Yellow 66, 14, 16, 29, 105, C.I. I. Solvent Blue 70, 35, 63, 36, 50, 49, 111, 105, 97, 11, C.I. I. Solvent Red 135, 81, 18, 25, 19, 23, 24, 143, 146, 182 and the like.

  Examples of the transfer film substrate on which an image is formed with the ink include general-purpose resin films such as polyethylene, polypropylene, nylon, polyethylene terephthalate, and the like, in particular as long as they can withstand heat treatment during transfer. Either can be applied.

  A transparent release layer is provided on the image forming surface of the transfer film (that is, a position between the film and the ink image). The release layer is peeled off from the film during transfer, and the image layer is removed after transfer. It is something to protect. Examples of the release layer include known materials such as (meth) acrylic acid resins, copolymers of styrene and (meth) acrylic acid lower alkyl esters, vinyl chloride-vinyl acetate copolymers, chlorinated rubber, and nitrocellulose. Can be formed. Moreover, you may add mold release substances, such as a wax, a silicone resin, and a fluororesin, to these peeling layers.

  After printing the image layer on the release layer, an adhesive layer is applied on the film. The adhesive layer is composed of, for example, a hot melt adhesive, and specifically includes acrylic resin, vinyl acetate resin, rubber resin, polystyrene, polyolefin, epoxy resin, vinyl chloride-vinyl acetate copolymer, diallyl. A phthalate resin, a chlorinated polyolefin, a polyamide resin, and a mixture thereof can be selected and used.

Examples are shown below, but the present invention is not limited to these examples.
In addition, the part in an Example is a weight part. Moreover, about the lightness value, the plate of the resin composition which comprises each exterior was measured using the color difference meter TC-3600 by Tokyo Electric Decoration Co., Ltd.
Example 1 (see FIGS. 1 to 3)
Preparation of reversible thermochromic ink (i) 4.5 parts of 2- (2-chloroanilino) -6-di-n-butylaminofluorane as component (1,) 1,1-bis (4'-hydroxy) as component (b) Phenyl) reversible consisting of 4.5 parts of n-decane, 7.5 parts of 2,2-bis (4'-hydroxyphenyl) hexafluoropropane, and 50.0 parts of 4-benzyloxyphenylethyl caprate as component (c) Microcapsule pigment encapsulating thermochromic composition (T ₁ : −20 ° C., T ₂ : −9 ° C., T ₃ : 40 ° C., T ₄ : 57 ° C., ΔH: 63 ° C., average particle size: 2.5 μm) 12.5 parts, succinoglycan (shear thinning agent) 0.33 parts, urea 10 parts, glycerin 10 parts, nonionic permeability imparting agent 0.6 parts, modified silicone 0.1 part of an antifoaming agent, A reversible thermochromic ink consisting of 0.1 part of an antifungal agent and 66.37 parts of water was prepared.

Preparation of reversible thermochromic writing instrument 1 The ink 4 (cooled to 0 ° C. or lower in advance to develop the color of the microcapsule pigment in black and then allowed to stand at room temperature) is sucked into a polypropylene pipe (ink containing cylinder 21). It was filled and connected to the ballpoint pen tip 3 through the resin holder 22.
Next, from the rear part of the polypropylene pipe 21, the ink backflow prevention body 5 (liquid stopper) having a viscoelasticity mainly composed of polybutene is filled, and the tail plug 23 is fitted to the rear part of the pipe, and the front shaft cylinder Then, after the rear barrel (shaft barrel 6) was assembled and the cap 7 was fitted, a degassing treatment was performed by centrifugal treatment to obtain a reversible thermochromic ballpoint pen.
The ball-point pen tip 3 is formed by holding a stainless steel ball having a diameter of 0.5 mm in a ball holding portion formed by cutting a metal material, and the ball is urged forward by a spring body. is there. Further, a SEBS resin member having a convex curved top is attached as a rubbing member 8 to the rear portion of the rear barrel 6.
In addition, the shaft cylinder 6 which is the writing instrument exterior had a white appearance obtained by injection molding a polycarbonate resin to which titanium oxide was added, and the lightness value was 9.52.
When writing on paper with the obtained ballpoint pen, a black handwriting was obtained. When the handwriting was rubbed with the rubbing member 8, the handwriting was discolored and was no longer visible. Since this state could be maintained at room temperature, the characters could be written again in the area where the scratch was erased. Furthermore, after the ballpoint pen was left for 2 hours in direct sunlight, it was written on the paper again. As a result, a black handwriting similar to the previous handwriting was obtained, and the handwriting was erasable.

Furthermore, the reversible thermochromic writing instrument 1 was obtained by laminating (transferring) the transfer layer 9 using film transfer printing so that the surface of the shaft cylinder 6 of the reversible thermochromic ballpoint pen circulates in the radial direction.
The transfer film is formed by forming an image layer 92 by on-demand inkjet printing on the release layer 91 side of the PET film (support) provided with the release layer 91, and further providing an adhesive layer 93. Laminated body. Therefore, since a transfer film having a desired design can be quickly produced without requiring preparation of a printing plate or specialized printing technology, the reversible thermochromic writing instrument 1 can be produced with a small lot corresponding to customer needs.
In the reversible thermochromic writing instrument 1 on which the transfer layer 9 was formed, the contrast between the image layer 92 and the color tone of the shaft tube 6 was clear, and the reproducibility of the image color tone was high.
Therefore, it became a writing instrument with high novelty effect with special handwriting performance and excellent decoration.

Example 2 (see FIGS. 1 and 3)
Preparation of reversible thermochromic ink (i) 1.0 part of 1,2-benz-6- (N-ethyl-N-isoamylamino) fluorane as component, 1,3-dimethyl-6-diethylaminofluorane 2.0 Part (b), 1,1-bis (4′-hydroxyphenyl) 2-ethylhexane 8.0 parts, (c) color memory comprising 40.0 parts palmitic acid-4-methylbenzyl as component (c) A microcapsule pigment (T ₁ : -2 ° C., T ₂ : 10 ° C., T ₃ : 35 ° C., T ₄ : 48 ° C., ΔH: 38 ° C., average particle size: 2. 12.5 parts, succinoglycan 0.33 parts, urea 10 parts, glycerin 10 parts, nonionic permeability imparting agent 0.6 parts, modified silicone antifoaming agent 0.1 Part, antifungal agent 0.1 part, water 6 A reversible thermochromic ink consisting of 6.37 parts was prepared.

Production of reversible thermochromic writing instrument 1 The ink 4 (cooled in advance to −2 ° C. or less to cause the microcapsule pigment to develop a red color and then allowed to stand at room temperature) is placed on a polypropylene pipe (ink containing cylinder 21). The resin was sucked and filled and connected to the ballpoint pen tip 3 through the resin holder 22.
Next, from the rear part of the polypropylene pipe 21, the ink backflow prevention body 5 (liquid stopper) having viscoelasticity mainly composed of polybutene is filled, and the tail plug 23 is fitted to the rear part of the pipe, followed by centrifugation. The ball-point pen refill was obtained by performing a deaeration process.
Further, reversible thermal discoloration is achieved by assembling the obtained ballpoint pen refill into the shaft cylinder 6 equipped with a rear end knock type protruding and retracting mechanism (a mechanism in which the pen tip protrudes and retracts from the base portion of the front of the shaft cylinder by pressing the rear end). A sex ballpoint pen was obtained.
The ball-point pen tip 3 is formed by holding a stainless steel ball having a diameter of 0.5 mm in a ball holding portion formed by cutting a metal material, and the ball is urged forward by a spring body. is there. Further, the front portion (base portion) of the shaft tube 6 is made of SEBS resin and can be used as a scraping member when the pen tip is immersed.
The shaft cylinder 6 as the writing instrument exterior has a pastel pink-like appearance obtained by injection molding a polycarbonate resin to which a red pigment and titanium oxide are added, and has a lightness value of 8.45. Met.
When writing on the paper surface using the obtained ballpoint pen, a red handwriting was obtained, and when the handwriting was rubbed with a rubbing member (a base part after immersion of the pen tip), the handwriting was discolored and was not visually recognized. . Since this state could be maintained at room temperature, the characters could be written again in the area where the scratch was erased. Furthermore, after the ballpoint pen was left for 2 hours in direct sunlight, it was written again on the paper surface. As a result, a red handwriting similar to the previous handwriting was obtained, and the handwriting was erasable.

Furthermore, the reversible thermochromic writing instrument 1 was obtained by laminating (transferring) the transfer layer 9 using film transfer printing so that the surface of the shaft cylinder 6 of the reversible thermochromic ballpoint pen circulates in the radial direction.
The transfer film is formed by forming an image layer 92 by on-demand inkjet printing on the release layer 91 side of the PET film (support) provided with the release layer 91, and further providing an adhesive layer 93. Laminated body. Therefore, since a transfer film having a desired design can be quickly produced without requiring preparation of a printing plate or specialized printing technology, the reversible thermochromic writing instrument 1 can be produced with a small lot corresponding to customer needs.
In the reversible thermochromic writing instrument 1 on which the transfer layer 9 was formed, the contrast between the image layer 92 and the color tone of the shaft tube 6 was clear, and the reproducibility of the image color tone was high.
Therefore, it became a writing instrument with high novelty effect with special handwriting performance and excellent decoration.

Comparative Example 1
The thermochromic writing instrument 1 (ballpoint pen) is formed in the same configuration except that the shaft cylinder 6 is a black shaft cylinder having a lightness value of 5.17 obtained by injection molding a pellet in which a black pigment is added to polycarbonate resin. did.
When writing on the paper surface using the obtained writing tool, a black handwriting was obtained. When the handwriting was rubbed with the rubbing member 8, the handwriting was discolored and was not visually recognized. However, when the ballpoint pen was left in a place exposed to direct sunlight for 1 hour and then written on the paper again, the ink was transparent and the handwriting was not visible.
Further, since the transfer layer 9 laminated on the shaft cylinder 6 has transparency without the white layer on the lower surface of the image layer 92 by on-demand ink jet printing, the contrast between the image layer 92 and the color tone of the shaft cylinder 6. Was unclear and image color tone reproducibility could not be obtained.

Comparative Example 2
A thermochromic writing instrument 1 (ballpoint pen) was formed in the same configuration as the shaft tube 6 except that the red pigment added to the polycarbonate resin was increased to a red shaft tube having a brightness value of 6.10.
When writing on the paper surface using the obtained writing instrument, red handwriting was obtained. When the handwriting was rubbed with a rubbing member (base part), the handwriting was discolored and was no longer visible. However, when the ballpoint pen was left in a place exposed to direct sunlight for 1 hour and then written on the paper again, the ink was transparent and the handwriting was not visible.
Further, since the transfer layer 9 laminated on the shaft cylinder 6 has transparency without the white layer on the lower surface of the image layer 92 by on-demand ink jet printing, the contrast between the image layer 92 and the color tone of the shaft cylinder 6. Was unclear and image color tone reproducibility could not be obtained.

T ₁ complete color development temperature T ₂ color development start temperature T ₃ color erase start temperature T ₄ complete color erase temperature ΔH hysteresis width 1 thermochromic writing instrument (ballpoint pen)
2 Refill 21 Ink receiving cylinder 22 Holder 23 Tail plug 3 Ballpoint pen tip 4 Thermochromic ink 5 Ink backflow prevention body 6 Shaft cylinder 7 Cap 8 Scraping member 9 Transfer layer 91 Peeling layer 92 Image layer 93 Adhesive layer

Claims (6)

  A thermochromic writing instrument that contains ink that can be decolored or discolored by heating, and has a lightness value of 6.3 or more on the exterior of the writing instrument, and a thermal discoloration formed by laminating a transfer layer by film transfer on the exterior surface Sex writing instrument.   The thermochromic writing instrument according to claim 1, wherein the transfer layer is laminated using a transfer film imaged by an on-demand printing method.   The thermochromic writing instrument according to claim 2, wherein the transfer film is imaged by an inkjet method.   The ink comprises at least (a) an electron-donating color-forming organic compound, (b) an electron-accepting compound, and (c) a reaction medium that controls the color reaction of (a) and (b). The thermochromic writing instrument according to any one of claims 1 to 3, comprising a microcapsule pigment encapsulating a reversible thermochromic composition and changing color from colored to colorless upon heating. The microcapsule pigment is a pigment that exhibits a large hysteresis characteristic with respect to a color density-temperature curve, exhibits a tautomerism between a colored state and a colorless state, and has a holding temperature range in which both states can coexist in a normal temperature range. in the process of temperature from the state rises, beginning decolorized to reach the temperature T _3, become completely colorless state at a temperature T ₄ or more temperature range than the temperature T _3, in the process of temperature is lowered from colorless state, the began to color to reach a lower temperature T ₂ than the temperature T _3, become completely colored state at a low temperature T ₁ of the following temperature range than temperature T _2, colored state at a temperature range between the temperature T ₂ and the temperature T ₃ or show the hysteresis characteristics of the colorless state can be maintained, temperatures _{T 1} is in the range of -30～10 ° C., thermochromic writing instrument according to claim 4, wherein the temperature _{T 4} is in the range of 30 to 80 ° C..   The thermochromic writing instrument according to any one of claims 1 to 5, comprising a rubbing member.

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