JPS63303747A - Ink jet recording method - Google Patents

Abstract

PURPOSE:To use pressure-sensitive copying paper of highly general use and thereby make simultaneous duplication possible by heating thermal ink to a specific temperature, performing ink jet recording on the pressure-sensitive copying paper while the thermal ink is maintained in a liquid state and permitting said copying paper with thermal ink coagulated and fixed after cooling to pass through a pressure-applying means. CONSTITUTION:Thermal ink is melted at 50 deg.C min at the time of device operation, and an ink jet recording head 12 and an ink tank 13 are always heated by a heater 14 so that the ink is kept in liquid form. The molten thermal ink generates ink droplets through a nozzle orifice 15, and when the ink droplets settle on the surface of the pressuresensitive copying paper, they are spontaneously cooled to be fixed on the surface as solid ink 16. Next, the ink is compressed into the paper through a compression process. There, pressure is applied to the first copying paper 21 and the second copying paper 22, and a microcapsule in the pressure-sensitive copying paper 11 breaks to allow only a pressure- applied part to develop a color. Thus the same pattern as recording paper 20 is concurrently duplicated on the copying papers 21, 22.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a recording method that can use the highly versatile pressure-sensitive copying paper used in impact-type wire tod matrix printers.

(Prior art) The inkjet recording method uses liquid ink of 20μ to 10μ
This is a method in which the ink is ejected from a nozzle orifice with a diameter of 0 μm to a droplet, and the droplets form a dot matrix to print characters, etc., using a piezo type, nuheater, etc., which ejects ink by the pressure waves of a piezoelectric element. There are bubble types that eject ink using the pressure of bubbles generated by energy. Due to the printing principle, both generate less noise (and can be driven at high frequencies, so they are being commercialized as high-speed printers with no noise. However, on the other hand, although they are noisy, a set of wires with a strong impact force When pressure-sensitive copying paper, which is commonly used in dot matrix printers, is used, the inkjet recording method has almost no impact force, so it is difficult to make copies.

[Problem that the invention seeks to solve]

Therefore, with non-impact printing techniques such as inkjet recording methods, pressure-sensitive copying is difficult, and its use as a printer is limited and its versatility is low.

The present invention is intended to solve these problems, and its purpose is to develop an inkjet recording method that allows simultaneous copying using the highly versatile pressure-sensitive copying paper used in wire dot printers. It is about providing.

[Means for solving problems]

In the inkjet recording method of the present invention, at least 50°
Thermal ink, which develops a melting point of C or higher and is in a solid state at a temperature of 50°C or lower, is heated to a temperature of 50''C or higher while maintaining a liquid state, and is applied to pressure-sensitive copying paper consisting of recording paper and one or more sheets of copying paper. a first step of performing inkjet recording; a second step in which the thermal ink recorded on the pressure-sensitive copying paper is solidified by natural cooling and fixed on the recording paper surface of the pressure-sensitive copying paper; This is an inkjet recording method characterized by comprising a third step of passing the pressure-sensitive copy paper on which the thermal ink has been fixed through a pressure application means.

The thermal ink according to the present invention must have a melting point of at least 50°C or higher in order to be able to fix at room temperature, and must have physical property values suitable for inkjet recording in a state of melting, that is, it must have an optimal viscosity as an ink. is 1-20
A Pmast surface tension of 12 to 70 mN/m is applied. Further, after the thermal ink is fixed and solidified, it is made of a hard material so as to prevent pressure loss from being crushed by the pressure applying means in the third step of the present invention. To meet these requirements, natural wax or synthetic wax is used as the base material for thermal ink, and dyes and pigments are dissolved or dispersed in these base materials, and if necessary, the hardness of the ink is increased. Therefore, the thermal ink according to the present invention can be obtained by adding a film hardening agent, a hard compound, etc. to the ink. Specifically, known waxes such as carnauba wax and polyolefin wax, oxidized hydrocarbon waxes containing hydroxyl groups in the molecule, higher fatty acids and derivatives thereof, dialkyl ketone 7 types, and benzene derivatives shown in formula (I) are used. Waxes such as In-type waxes having a penetration degree (according to the method of JIS K2235, 25°C) at hardening bind-off of 10 or less are preferable.

Selected from famoyl group, acetoxyl group, acetamido group, and polyoxyethylene group.

The dye used as the coloring agent is suitably an oil dye, a direct dye, or an acid dye that has good solubility in the wax, and pigments such as carbon black can also be used in a dispersed manner.

Figure m1 shows ink 9! using the recording method of the present invention. Futuki 0
The thermal ink according to the present invention can be used in an inkjet! The second recording head 12 and the ink tank 13 are constantly warmed by the heater 14. Further, the pressure rollers 17 have a spacing between the rollers so as not to color the entire pressure-sensitive copy paper when pressing the pressure-sensitive copy paper 11, and to prevent the fixed ink 1B from melting or softening due to heat applied to the roller 17. In addition, the heat of the heater 14 is not transferred to the roller 17, and the roller 17 must be kept at a temperature of 40° C. or lower at all times.

[Effect]

The molten thermal ink passes through the nozzle orifice 15 of the heated inkjet recording head 12 as shown in FIG.
When an ink drop is generated and adheres to the surface of the pressure-sensitive copying paper 110, it is naturally cooled and fixed as a solid ink 16 on the surface. The fixed solid ink 16 is the 21st! i1
In the pressurizing process shown in 1, the paper is pushed into the paper as shown in (b), and at that time pressure is applied to the first copy paper 2 and the second copy paper 22, and the inside of the pressure-sensitive copy paper 11 is Since the microcapsules rupture and color develops only in the areas where pressure is applied, the same pattern as that on the recording paper 20 is simultaneously copied onto the copy papers 21 and 22.

〔Example〕 The present invention will be explained based on examples.

Thermal inks according to the invention were prepared as in Examples 1-5. Numbers in parentheses represent weight percentages.

As a comparative example, an ink having the following composition was prepared.

Comparative Example 1 Carbon Black (20) Comparative Example 2 Melting point for Examples 1 to 5 and Comparative Example 1.2, 10
Table 1 shows the melt viscosity and penetration at 0°C. Melt viscosity is B with heater! ! With a viscometer, the penetration is JIS
Measurements were carried out at 25°C according to K 2235.

Table 1 The recording apparatus shown in Figure 1 is equipped with a heater and a thermistor to keep the head 12 and ink tank 13 at 130°C, and the pressure roller 17 is made of stainless steel and has a diameter of 30 mm, and is made of butyl rubber. with a diameter of 30 mm and a hard r
Jt 30, 50, and 70 degrees were prepared. The pressure-sensitive copying paper used was N-40 manufactured by Mitsubishi Paper Mills, with a number of copies of 1+3.

The thickness of this paper is approximately 0.17 mm, and the pressure roller 1
Gap adjustment in step 7 is performed by actually printing and adjusting the gap from 0 to
An experiment was conducted by adjusting the position within a range of 0.2 mm to the position where the copied characters or figures were most clearly colored.

The thermal inks of Examples 1 to 5 and Comparative Examples 1.2 are supplied to the ink tank 13 in the form of a pellet to the recording apparatus, and the heater is activated to purge the head 12 until it is filled with thermal ink. Inkjet recording of the present invention was performed on each of them. The ink drops adhering to the surface of the pressure-sensitive recording paper are naturally fixed before being applied to the roller 17, and after being pressurized by the roller 17, the copy paper develops color. Table 2 shows the results using each ink and roller.

The ink of Comparative Example 1.2 had insufficient hardness and caused blocking on the roller 17, causing it to collapse on the recording paper. Therefore, the pressure of the roller 17 is applied to the entire paper (
Due to the gap (Omm), the entire surface of the copy paper developed color, and in the end, no copies could be made. On the other hand, even with a pressure roller made of butyl rubber, when the hardness rIt was 30 degrees, the rubber was too soft, so it did not have the ability to copy more than the second sheet. From the above results, it is desirable that the pressure roller is made of a material that is as hard as possible and has minimal deformation and warpage and surface roughness.

Table 2 0 Can print well up to the 3rd copy 0 Can print well up to the 2nd copy Δ Can print well up to the 1st copy × The 1st copy is also unclear [Effect of the invention] As stated above. According to the inkjet recording method of the present invention, it is possible to use the simultaneous pressure-sensitive copying paper used in the highly versatile impact dot matrix printer with an inkjet printer, which was previously thought to be impossible. High-speed printing is possible with no noise, and the effect is great.

[Brief explanation of drawings]

FIG. 1 is a diagram illustrating an inkjet record a device according to the inkjet record method of the present invention. Figure 2 (tal+b) is a diagram showing the principle of the pressurizing means according to the inkjet recording method of the present invention ((a) is a diagram showing the state of the fixing ink before being pressurized, (b) is a diagram showing the state of the fixing ink before being pressurized. (Diagram showing the foreshadowing of the applicant.) Applicant Seiko Epson Co., Ltd. Agent Patent attorney Tsutomu Mogami and one other person im EiZ diagram

Claims (1)

[Claims] Pressure-sensitive copying consisting of recording paper and one or more sheets of double-print paper by heating thermal ink, which has a melting point of at least 50°C or higher and is in a solid state at a temperature of 50°C or lower, to a temperature of 50°C or higher and maintains the liquid state. a first step of performing inkjet recording on paper; a second step in which the thermal ink recorded on the pressure-sensitive copying paper is solidified by natural cooling and fixed on the recording paper surface of the pressure-sensitive copying paper; An inkjet recording method comprising a third step of passing the pressure-sensitive copying paper on which the thermal ink has been fixed through a pressure applying means.