JPH04836B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a method for printing and imparting identification information indicating positional information for cutting or sewing, member names, used parts, etc. to a fabric during automatic sewing or the like. [Prior Art] Conventionally, strings have been used to give identification symbols containing necessary information during sewing.
This can be removed with a brush or a brush after sewing is completed, but in addition to being labor intensive and cumbersome, it also has the drawback of being difficult to completely remove. On the other hand, in the highly automated sewing process, the necessary information to be given to the fabric is encoded according to data from a computer, and is given by printing or line drawing at the required position on the fabric, and this identification symbol is attached to the fabric at the required position. The machine reads the symbol and cuts and sews it according to the symbol. In such a case, the preferable conditions for the means for providing information are at least (1) the ability to print or imprint data information from a computer directly onto the fabric; (2) Since the fabric is flexible, printing should preferably be possible without contact. There is an inkjet method as a means to satisfy this condition. On the other hand, with regard to media such as ink for printing and applying the above-mentioned identification marks on fabrics, it is required that the identification marks are machine-readable when needed, and when the identification marks are sewn into a product. must be erased or colorless. Specific means for this are (a) Things that cannot be recognized under visible light but can be recognized under non-visible light such as ultraviolet light. (b) Those that can be recognized under visible light but can be easily erased or made colorless. First, as type (a), the use of a fluorescent whitening agent that develops color under ultraviolet light has been proposed in JP-A-51-72509 and JP-A-58-49765. On the other hand, (b), which can be detected with visible light and can be erased if left undisturbed, is
−29056, etc. All of these means have the disadvantage that if the fabric on which the identification symbol is printed is black or dark color, it is difficult to recognize it. This is a fundamental problem because it needs to be colorless under visible light, so it is necessary to use an ink in which dyes and colorants are dissolved in the ink medium, and the binder component also needs to be optically transparent. it is conceivable that. On the other hand, when optically opaque colored substances (such as pigments) are used, there is a contradictory problem in that they are recognized under visible light and the above objective cannot be achieved. [Problems to be Solved by the Invention] The purpose of the present invention is to improve the above-mentioned deficiencies of the conventional technology and to provide a fabric that has very good identifiability even when the fabric to which an identification symbol having an information function is given is a dark color. It is an object of the present invention to provide a method for printing an identification symbol having an information function on a fabric using an inkjet method using ink that can be easily erased or made colorless. [Means for Solving the Problems] In order to achieve the above object, the present invention has the following configuration. In other words, when printing identification symbols with information functions on fabrics, the melting point or softening point is 60 or higher.
Water-insoluble resin at 160℃ at a concentration of 0.5 to 20% by weight,
A method for printing an identification symbol having an information function on a fabric, characterized in that the identification symbol is printed on the surface of the fabric by an inkjet method using an ink finely dispersed in water with an average particle size in the range of 0.2 to 5μ. It is based on The present invention will be explained in more detail. The basic requirements of the present invention are (a) printing and imparting identification symbols with information functions to fabrics using the inkjet method; (b) A water-insoluble resin that softens or melts at 60 to 160° C. is used as a recording component of the ink, and the resin is used in an ink medium in a finely dispersed state with an average particle size in the range of 0.2 to 5 μm. (c) The ink has a function of erasing the applied identification mark, and by heating the fabric to which the identification mark has been applied, the mark applied to the fabric can be erased. It is characterized by the combination of three points. In other words, identification symbols with information functions given to fabrics are the same as those printed with ordinary ink.
In addition to being fully recognizable under visible light, identification symbols that are no longer needed can be erased by heating the fabric to an extent that does not damage the fabric, as the resin that is the recording component melts and becomes transparent. . The water-insoluble resin used in the present invention is not limited by its chemical structure, but has a melting point or softening point of 60 to 160°C, is substantially insoluble in an ink medium mainly composed of water, and is not limited by its chemical structure. Any material that can be finely dispersed within the average particle size range of 0.2 to 5 μm may be used. Specific examples include resins such as polystyrene, styrene-acrylic, polypropylene, polyethylene, polymethacrylate, polyester, and polyamide. In the present invention, the above-mentioned resins and copolymer resins thereof having a melting point or softening point of 60 to 160°C are used.
Although this value is not critical, a value of 60°C is used. Although this number is not critical,
Products with a low melting point or low softening point of less than 60°C have problems such as discoloration or increased stickiness due to slight heating during the process. On the other hand, resins with a melting point or softening point of 160° C. or higher are not preferable because they require high temperatures to melt and become transparent, causing problems such as deterioration and discoloration of the fiber material and a decrease in color fastness. Particularly preferred are those having a melting point or softening point of 80 to 140°C. The reason for finely dispersing such resin in the average particle size range of 0.5 to 5μ is that it does not cause troubles such as nozzle clogging, and it has good identifiability on fabrics that are given by printing identification symbols with information functions. This is to ensure that. That is, if it contains coarse particles, it causes nozzle clogging, and conversely, if the particle size is too small, it tends to deteriorate the distinguishability when applied to dark-colored fabrics. As already explained, the means for obtaining the ink in which fine resin particles are dispersed is not particularly limited, but it can be produced by the following method. (a) The lumped resin is finely pulverized using a known pulverizing and dispersing means, such as a pole mill or a sand mill, and then dispersed in an ink medium. (b) A vinyl monomer is emulsion polymerized by a known method to form an emulsion finely dispersed in an ink medium. (c) After dissolving the resin in a solvent, it is precipitated into a non-solvent solvent for the resin. Such water-insoluble resins are used in the ink at concentrations ranging from 0.5 to 20% by weight. Since the present invention uses the resin as a recording component, if the resin concentration is too low, the distinguishability on dark-colored fabrics will deteriorate, and if it is too high, it will be difficult to make it colorless. In the present invention, it is possible to add a chemical to these resins to improve their identifiability within a range that does not affect the colorless and transparent state after heating. Specifically, fluorescent whitening agents can be cited as agents that can be identified even under non-visible light. This fluorescent whitening agent is selected from one that dyes or dissolves in the resin and has good fluorescent coloring properties. Further, if necessary, dyeing sheet components can be introduced into the resin by means such as copolymerization. As the optical brightener, for example, various optical brighteners listed in Color Index can be used. In the present invention, since the insoluble resin itself emits fluorescence, identification can be improved. However, simply mixing dyes that have no affinity or dyeability with resin into the ink medium has no effect. Next, as a substance that can be mixed into the resin in order to improve the distinguishability, there may be mentioned a colorant or a combination of a colorant and an auxiliary agent that can be decolored or colorless by heating. Specific examples include a combination of a color former and a volatile color developer, a PH indicator and a PH regulator, and a preferred combination is a color former and a volatile color developer. Here, the term "color former" refers to a substantially colorless organic compound that takes on a visible coloring structure by the energy of acid or alkali oxidation. In particular, compounds used as photosensitive dyes or heat-sensitive dyes that develop color with acid are the ones used in the present invention. suitable for the purpose. Examples of specific compounds include triphenylmethane phthalide series such as crystal violet lactone and malachite green lactone, fluoran series, phenothiazine series such as benzoylleucomethylene blue, indolyl phthalide series, lyuco auramine series, and spiropyran series. , rhodamine lactam, triphenylmethane, azaphthalide, and triazene. On the other hand, a color developer refers to a substance that causes a color former to develop a color, and in the case of a color former that develops color with an acid, acids such as phenols and carbonic acids are used. In the present invention, it is preferable that the resin melts and volatilizes or sublimates when heated. Specific examples include phenol, cresol, halogenated phenol, lower alkylphenol, phenylphenol, salicylic acid, salicylic acid derivatives, etc. Examples include phenolic compounds, organic carboxylic acids such as acetic acid and benzoic acid, and volatile inorganic acids such as hydrochloric acid. Furthermore, in order to completely render the resin colorless after volatilization of the color developer, it is also preferred to incorporate a non-volatile substance that inhibits the color development of the color former, that is, a non-volatile desensitizer, into the resin. Among known desensitizers, non-volatile substances with large molecular weights include polyethyleneimine, polyoxyethylene alkylamine, higher alkylamine, polyethylene glycol, polypropylene glycol,
Examples include polyoxypropylene alkylamine and polyvinylpyrrolidone. In the present invention, it is preferable to dissolve the color former and the non-volatile desensitizer in the resin, but the volatile color developer may be blended into the resin, or
It can also be added into the ink. According to studies conducted by the present inventors, it has been found that Color Former exhibits better coloring properties when it is dissolved in a resin and dispersed, rather than when the original color former is directly dispersed in an ink. In the present invention, the preferred ink medium is one in which water is the main medium, and in addition to water, glycols known as anti-drying agents (ethylene glycol, propylene glycol, polyethylene glycol, polypropylene glycol, butanediol, hexylene glycol, High boiling point water-soluble solvents such as glycol ethers (ethylene glycol monomethyl ether, diethylene glycol monomethyl ether, etc.) can be blended. In the present invention, in addition to these, a dispersant for dispersing the resin, an emulsifier, a preservative, a chelating agent, a water-soluble polymer, a surfactant, an additive for preventing bleeding, etc. can be added. A typical ink composition for carrying out the present invention is as follows: 0.5 to 20% water-insoluble resin component dispersed, emulsifier 0.05 to 20% (5 to 100% to resin content), glycols 2 to 40% water, balance. In the above ink composition, if a fluorescent brightener is further added to the resin, it is 0.05 to 5%, if a color former is added, it is 0.1 to 10%, a volatile color developer is 0.05 to 10%, and a desensitizer is added. 0.05 to 5% (all concentrations relative to the resin) is preferable. When the above-mentioned ink is used to print an identification symbol having an information function on a fabric, it has the effect of a white pigment when nothing is added to the resin. If the method according to the present invention is applied to a dyed fabric, it has sufficient distinguishability under visible light. When a color former is blended with the resin, an identification symbol can be given as a predetermined color depending on the type and composition of the color former, and fabrics of various colors can be given sufficient identification recognition under visible light. . It has been confirmed that the finely dispersed resin ink used in the present invention has less bleeding on fabric than soluble ink. After the assigned identification symbol is used in a process such as sewing, heating the resin to a temperature higher than the softening point of the resin melts the resin and makes it colorless to the naked eye. Furthermore, when ink containing a fluorescent whitening agent is used, the discrimination ability under ultraviolet light from a light source such as a blacklight, or under the coexistence of visible light and ultraviolet light such as a fluorescent lamp, is lower than that of conventional dissolvable inks. This represents a significant increase compared to the previous year. The white color recognized under visible light disappears by heating, making it colorless. The fabric referred to in the present invention refers to materials for clothing and industrial use used for cutting or sewing, that is, various natural,
Or knitted fabrics, non-woven fabrics, paper made of synthetic fibers,
Refers to films, leather, etc. The inkjet method is not particularly limited, and includes any method that can print on fabric in the form of minute droplets in response to a signal from a computer. Identification symbols that have information functions include fabric type, color, parts, front and back identification information, and lines and marks necessary for cutting and sewing. Any shape such as code, solid, line, point indicating position,
It can be drawn on fabric depending on its size. The present invention will be further explained below with reference to Examples. (Example) Example 1 Styrene-acrylic resin with a softening point of 120°C and a molecular weight of approximately 40,000 (“Himer SBM-” manufactured by Sanyo Kasei Co., Ltd.)
73F'') were used to prepare three types of resin finely dispersed inks: A resin component only, B color former combination, and C fluorescent whitening agent combination. Adjustments were made in the following order. (1) Heat, melt, mix and coarsely grind the resin and compounded ingredients. (2) Use a sand grinder (batch type) to coarsely grind 10 parts of the resin and 5 parts of a nonionic dispersant (Asahi Denka Co., Ltd. Pluronic F) as a dispersant. −108) Ion exchange water
The mixture was dispersed and pulverized using 85 parts and 100 parts of glass beads at 2000 rpn for 10 hours. (3) 10% resin dispersion with glass beads removed
50 parts 1,3-butanediol 25 parts ion-exchanged water
An ink was prepared by mixing 25 parts. (4) The ink was filtered through a 5μ filter and degassed under reduced pressure, and numbers were printed using an inkjet under the following conditions. Method: On-demand Nozzle diameter: 60 microns Resolution: 8 lines/mm Fabric: Wool and cotton Ink A is printed in white and has good discrimination for both cotton and wool fabrics. Ta. The printed portion of ink B is printed in pink, which also has good distinguishability. Ink C was white and was similar to A under visible light, but when black light was used in combination, the color developed clearly. When these fabrics were heat-treated by ironing, they all became substantially colorless under visible light. Table 1 shows the formulation of the ink and the evaluation after printing and erasing.

〔Effect of the invention〕

The present invention makes it possible to add an identification symbol having an information function to a fabric before cutting or sewing, even on black or dark-colored fabric, which was difficult to identify in the past, and exhibits good identifiability. Furthermore, such fabrics or sewn products can be made substantially colorless under visible light simply by heating, and identification marks can be erased in a simple manner without impairing the quality of the product.

Claims (1)

[Scope of Claims] 1. When printing an identification symbol with an information function on a fabric, a water-insoluble resin having a melting point or softening point of 60 to 160°C is used at a concentration of 0.5 to 20% by weight and an average particle size of 0.2 to 160°C. A method for printing an identification symbol having an information function, characterized in that the identification symbol is printed on the surface of a fabric by an inkjet method using ink finely dispersed in water in a range of 5μ. 2. A method for printing an identification symbol having an information function on a fabric according to claim 1, using a resin containing a fluorescent whitening agent as the water-insoluble resin. 3 Claim 1 using a resin containing a coloring agent that can be discolored by heating as a water-insoluble resin
A method of printing an identification symbol with an information function on the fabric described in Section 2.