JP3532027B2 - Pressure-sensitive transfer recording medium - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure-sensitive transfer recording medium in which a pressure-sensitive transfer colored layer is provided on the surface of a substrate. The pressure-sensitive transfer recording medium of the present invention can of course be used for a typewriter or a pressure-sensitive printer.
R) or an optical character reader (OCR). 2. Description of the Related Art Heretofore, there has been a demand for a pressure-sensitive transfer recording medium capable of obtaining a clear transferred image with no loss and having the obtained transferred image resistant to abrasion. Generally, when the pressure-sensitive transferable colored layer provided on the substrate is relatively soft,
Although the transferability is excellent, the durability of the obtained print is low, and conversely, when the coloring layer is relatively hard, there is a trade-off tendency that the durability of the print is improved but a transfer image with many defects is likely to be formed. . To overcome this problem, Japanese Patent Laid-Open Publication No. Sho 50-1
No. 38911 has a pressure-sensitive image forming layer comprising a binder material and a colorant on a flexible substrate, and further comprises a binder material comprising a normal adhesive substance on the pressure-sensitive image forming layer and contained therein. A pressure-sensitive transfer recording medium having a supercoating layer comprising inert synthetic thermoplastic spherical polymer particles having an average diameter of about 1 to 40 .mu.m. The supercoating layer has a slippery surface and does not adhere when touched, but it is said that when a transfer pressure is applied, it exhibits adhesiveness only in the area where the pressure is applied. However, when printing is performed by the method described in Japanese Patent Application Laid-Open No. 50-138911, relatively good printing can be obtained when pressure-sensitive transfer is performed on ordinary paper. However, it was found that printing on a paper or the like on which a format was printed in advance using a laser printer was extremely difficult, and that even if printing could be performed, the transferred ink was easily removed, resulting in printing with many defects. This is presumably because silicon oil used for fixing the toner adheres to the surface of the paper. Increasing the amount of the plastic oil contained in the pressure-sensitive image-forming layer reduces the loss of print, but this time, if the print portion is rubbed with a fingertip, the print becomes poor in abrasion resistance such that dirt spreads around. In particular, when reading with MICR or OCR, characters and symbols are identified by the amount of transferred ink.
If there are many defects or unevenness in the amount of transferred ink, it may cause poor reading, and when reading characters, the printed surface may be rubbed with a magnetic head or the like. Problems arise with use in such readers. [0005] That is, the problem to be solved by the present invention is that clear printing can be performed without any defects on any paper, such as paper on which a format has been printed in advance by a laser printer, and that the obtained print has good scratch resistance. An object of the present invention is to provide a good pressure-sensitive transfer recording medium. [0006] The pressure-sensitive transfer recording medium of the present invention is provided with a colored layer mainly composed of a binder and a colorant on the surface of a substrate, and further comprises a binder and an average layer on the colored layer. In a pressure-sensitive transfer recording medium provided with an adhesive layer composed of synthetic thermoplastic spherical polymer particles having a particle size of 1 to 40 μm, the colored layer contains 0.1 to 10% of an epoxy resin having an average molecular weight of 450 to 5500, It is characterized in that the synthetic thermoplastic spherical polymer particles in the adhesive layer are blended in a ratio of about 1 to 60 parts by weight with respect to 20 parts by weight of the binder, thereby solving the above problems. Preferably, the epoxy resin contained in the coloring layer has an average molecular weight of 450 to
It is in the range of 5500. [0007] The pressure-sensitive transfer recording medium of the present invention is provided with a pressure-sensitive transferable colored layer on the surface of a substrate. As the substrate, various materials conventionally used as the substrate, such as thin paper such as glassine paper or condenser paper, or a plastic film made of polyethylene resin or polyethylene-terephthalate resin can be used. [0008] The coloring layer mainly comprises a binder and a coloring material. As a coloring material, an inorganic pigment such as carbon black, magnetic iron, or titanium oxide, or an organic dye such as nigrosine or methyl violet can be appropriately used according to the purpose. In the pressure-sensitive transfer recording medium of the present invention, 0.1 to 10% of an epoxy resin is used as a binder in the colored layer.
Including. Epoxy resin improves both print transferability and scratch resistance when contained in 0.1% or more due to its tackiness when pressed and cohesive force when not pressed, but when the content exceeds 10%. The cohesive force becomes excessive, the binder property becomes strong, and the transfer property of the print deteriorates. The epoxy resin contained in the colored layer has an average molecular weight of 450 to 5500, more preferably 800 to 5500.
00 is preferred. The average molecular weight of the epoxy resin is 4
If it is less than 50, it becomes liquid at normal temperature and cannot exert sufficient cohesive force, so that it is difficult to obtain the effect of improving scratch resistance. On the other hand, the average molecular weight of the epoxy resin is 55
If it is larger than 00, the cohesive force tends to be excessive, and the sharpness of printing tends to deteriorate. In the coloring layer, a pigment dispersant, a wax, a plasticizer, and the like can be appropriately contained as necessary in addition to the coloring material and the binder. In order to provide a colored layer on a substrate, a colorant, a binder and other additional components may be blended and kneaded, and then applied on the substrate using a hot melt coating method, a solvent coating method or the like. . Generally, the coloring layer is provided on the substrate at a rate of about 0.5 to 6.0 g / m ² . An adhesive layer can be provided on the colored layer for the purpose of further improving transferability. The adhesive layer mainly comprises a binder and inert synthetic thermoplastic spherical polymer particles having an average particle diameter of 1 to 40 µ. As the binder used for the adhesive layer, paraffin wax, wax having adhesive properties such as microcrystalline wax, polybutene elastomer, it is preferable to use a mixture of a resin and wax having adhesive properties such as polyisobutylene, A resin having low adhesiveness such as polyethylene may be used. Also, as synthetic thermoplastic spherical polymer particles,
Polyethylene particles and polytetrafluoroethylene particles are used. The synthetic thermoplastic spherical polymer particles are blended at a ratio of about 1 to 60 parts by weight with respect to 20 parts by weight of the binder. The adhesive layer may appropriately contain a white pigment such as titanium oxide or a filler such as silica, in addition to the binder and the synthetic thermoplastic spherical polymer particles. In general,
The adhesive layer is provided on the colorant layer at a rate of about 0.5 to 2.0 g / m ² . [0014] In addition to the coloring layer and the adhesive layer on the substrate, other than the above-mentioned objects of the present invention,
Various functional layers such as a release layer (release layer) can be provided as necessary. Examples 1 to 4 and Comparative Examples 1 to 3 Colored layers having a composition of epoxy resin (average molecular weight 900) varied as shown in Table 1 on a 16 μm thick polyethylene film. Was applied so that the coating amount was 4.0 g / m ² . [Table 1] Next, a hot-melt adhesive layer having the following composition was applied so that the coating amount was 1.0 g / m ² . 5 parts by weight of paraffin wax 4 parts by weight of polybutene 1 part by weight of polystyrene particles (Allied Chemical Co., Ltd.) 1 part by weight Examples 5 to 11 and Comparative Examples 4 to 7 Tables 2 and 3 on a polyethylene film having a thickness of 16 μm.
As shown in Table ² , a colored layer having a composition in which the average molecular weight of the epoxy resin (content 1.5%) was changed was applied so that the coating amount was 4.0 g / m ² . [Table 2] [Table 3] Next, a hot-melt adhesive layer having the following composition was applied so that the coating amount was 1.0 g / m ² . 5 parts by weight of paraffin wax 4 parts by weight of polybutene 1 part by weight of polystyrene particles (Allied Chemical Co., Ltd.) 1 part by weight Evaluation of Examples 1 to 11 and Comparative Examples 1 to 7 The image was printed with a printing machine (CE550T, manufactured by Canon Inc.), and the sharpness of the print and the degree of stain when rubbed with a fingertip were visually evaluated in the following four stages. × ・ ・ ・ ・ ・ Inferior △ ・ ・ ・ ・ ・ Slightly inferior ○ ・ ・ ・ ・ ・ Good ◎ ・ ・ ・ ・ ・ ・ ・ Excellent In that case, the lower evaluation was regarded as the overall evaluation even if other items were good. Table 4 shows the results. [Table 4] REFERENCE EXAMPLE A 16 μm polyethylene film was coated with a coloring layer having the following composition so as to be 4.0 g / m ² . Ethylene hydroxyethyl cellulose 10 parts by weight Lard oil 4 parts by weight Refined rapeseed oil 7 parts by weight Magnetic iron oxide 24 parts by weight Ethyl acetate 55 parts by weight Next, a hot-melt type adhesive layer having the following composition was added at 1.0 g /
It was coated so as to be in m ^2. 5 parts by weight of paraffin wax 4 parts by weight of polybutene 1 part by weight of polyamide 1 part by weight When this was evaluated in the same manner as in Examples 1 to 11 and Comparative Examples 1 to 7, only printing with many voids was possible.
Further, when rubbed with a fingertip, the printed portion was stained and was evaluated as x. According to the pressure-sensitive transfer recording medium of the present invention,
Clear printing with no defects on paper with silicone oil adhered to the surface is possible, and the resulting print has good scratch resistance.

Continuation of the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B41M 5/03 B41M 5/10 B41J 31/00

Claims (1)

(57) [Claim 1] A coloring layer mainly composed of a binder and a coloring agent is provided on the surface of a base material, and a binder and a synthetic heat having an average particle diameter of 1 to 40μ are further provided on the coloring layer. In a pressure-sensitive transfer recording medium provided with an adhesive layer composed of plastic spherical polymer particles, the colored layer has an average molecular weight of 450 to 550.
0 to 10% by weight of an epoxy resin, and the synthetic thermoplastic spherical polymer particles in the adhesive layer are blended at a ratio of about 1 to 60 parts by weight with respect to 20 parts by weight of the binder. Pressure-sensitive transfer recording medium.