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JP-7855853-B2 - Pretreatment solution and image forming method

JP7855853B2JP 7855853 B2JP7855853 B2JP 7855853B2JP-7855853-B2

Inventors

  • 加藤 舞
  • 仁藤 謙

Assignees

  • コニカミノルタ株式会社

Dates

Publication Date
20260511
Application Date
20211202

Claims (8)

  1. A pretreatment solution for fabrics used in transfer printing, The pretreatment solution contains 50% by mass or more of a solvent having an organic/inorganic value (I/O value) of 1.0 to 3.0, and the solvent contains sulfoxides having an I/O value of 1.0 to 3.0. The surface tension at 25°C is less than 38 mN/m. Pretreatment solution.
  2. A pretreatment solution for fabrics used in transfer printing, A solvent having an organic/inorganic value (I/O value) of 1.0 to 3.0 is contained in an amount of 50% by mass or more relative to the pretreatment liquid, and has a surface tension of 28 mN/m or less at 25°C . Pretreatment solution.
  3. The solvent comprises one or more selected from the group consisting of sulfoxides, polyhydric alcohols, and polyhydric alcohol ethers, having an I/O value of 1.0 to 3.0. The pretreatment solution according to claim 2 .
  4. The boiling point of the aforementioned solvent is below the transfer temperature. The pretreatment solution according to any one of claims 1 to 3 .
  5. The aforementioned pretreatment solution further contains a surfactant. The pretreatment solution according to any one of claims 1 to 4 .
  6. A step of applying a pretreatment solution according to any one of claims 1 to 5 to a fabric containing natural fibers or synthetic cellulose fibers, The process involves transferring an ink layer containing a disperse dye onto a fabric to which the aforementioned pretreatment solution has been applied, including, Image forming method.
  7. The aforementioned fabric contains cotton or synthetic cellulose fibers. The image forming method according to claim 6 .
  8. The process does not include washing the fabric to which the ink layer containing the aforementioned disperse dye has been transferred. The image forming method according to claim 6 or 7 .

Description

This invention relates to a pretreatment solution and an image forming method. One known method of textile printing using inks containing dyes is the sublimation transfer printing method, which involves transferring an ink layer containing a disperse dye formed on a transfer medium. Disperse dyes generally exhibit hydrophobicity, making them easily fixed and dyed into fabrics containing hydrophobic fibers such as polyester. However, for fabrics containing hydrophilic fibers such as natural fibers, the large difference in polarity between the disperse dye and the fabric results in insufficient penetration and fixation, making dyeing difficult. Therefore, research is being conducted to improve the dyeing of disperse dyes into fabrics containing hydrophilic fibers such as natural fibers. One such method is a transfer printing method in which the fabric is swelled with a swelling agent, then transferred and printed, and finally a synthetic resin solution is applied to the surface of the dyed fabric (for example, Patent Document 1). As the swelling agent, an aqueous solution containing polyhydric alcohols such as polypropylene glycol (I/O value: 3.3) is used. Furthermore, a transfer printing method is known in which the fabric is pre-treated with a pre-treatment solution containing a swelling agent and a water-repellent agent, then transfer-printed, and the dyed fabric is washed to remove the swelling agent (for example, Patent Document 2). Polyhydric alcohols such as polypropylene glycol (I/O value: 3.3) are used as the swelling agent. Furthermore, a transfer printing method is known in which the fabric is pre-treated with a swelling agent, then transferred, and finally post-treated with a treatment agent containing a crosslinking agent and a catalyst (for example, Patent Document 3). As the swelling agent, a mixture of triethylene glycol (I/O value: 2.0) and ethylene glycol monoacetate (I/O value: 1.75) is used. Japanese Patent Application Publication No. 7-216763Japanese Patent Publication No. 2021-42514Japanese Unexamined Patent Publication No. 49-30686 The inventors have discovered that by treating fabrics containing hydrophilic fibers such as natural fibers with a pretreatment solution containing a solvent with an I/O value of 1.0 to 3.0 and a surface tension of less than 38 mN/m, images with high color density and friction fastness can be formed. Although the mechanism is not entirely clear, it is hypothesized as follows: Solvents with an I/O value of 1.0 to 3.0 readily attract hydrophilic fibers such as natural fibers with an I/O value of around 3.0, thus easily causing the fibers to swell. Furthermore, solvents with an I/O value of 1.0 to 3.0 readily attract disperse dyes with an I/O value of around 1.0, and therefore can function as carriers for disperse dyes in fabrics treated with a pretreatment solution containing these solvents. These actions allow the disperse dyes to penetrate more easily into the fibers of the fabric, thereby increasing the color intensity. Additionally, by reducing the amount of disperse dye remaining on the surface of the fibers without penetrating them, friction fastness can be improved. Furthermore, by lowering the surface tension of the pretreatment solution to a certain level, the pretreatment solution can penetrate more easily into the fibers, allowing the disperse dye to enter the fibers more readily. This further reduces the amount of disperse dye remaining on the fiber surface, thereby improving color intensity and friction fastness. In particular, color development tends to improve with higher fiber swelling (closer to an I/O value of 3.0) and higher penetration of the pretreatment solution (lower surface tension); friction fastness tends to improve with higher carrier capacity of the disperse dye in the pretreatment solution (closer to an I/O value of 1.0) and higher penetration (lower surface tension). The composition of the pretreatment solution of the present invention will be described in detail below. 1. Pretreatment solution: The pretreatment solution contains a solvent with an I/O value of 1.0 to 3.0. 1-1. Solvents The "I/O value" of a solvent with an I/O value between 1.0 and 3.0 is the ratio of the inorganic value (I) to the organic value (O) (inorganic value / organic value), and is one of the indicators of the degree of polarity. An I/O value closer to 0 indicates nonpolarity (hydrophobicity), while a larger value indicates polarity (hydrophilicity). Solvents with an I/O value of 1.0 to 3.0 readily agree with natural or synthetic cellulose fibers (I/O value: approximately 3.0) that constitute the fabric, as described above, and thus easily swell these fibers. Fabrics treated with a pretreatment solution containing such a solvent allow disperse dyes to easily penetrate into the fibers. On the other hand, solvents with an I/O value of 1.0 to 3.0 also readily agree with disperse dyes (I/O value: approximately 1.0), and can therefore function as carriers for d