JPS60259487A - Recording medium - Google Patents

Abstract

PURPOSE:To avoid the discoloration and fading of a recording agent as well as to impart excellent light resistance to a recording medium by specifying the ultraviolet rays permeability of the recording medium. CONSTITUTION:The ultraviolet rays permeability of a recording medium consisting of a light transmissible base material and an ink receiving layer provided on the base material is specified to 20% or less. The light transmissiveness can be sufficiently kept and the light resistance of each color can be greatly improved by using such light transmissible base material and ink receiving layer. Also, high-speed printing and multi-color printing can be attained by ink-jet recording, and recorded pictures can be used in optical instruments utilizing the transmitted light of recorded images.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a recording material used in an inkjet recording system, and particularly to a recording material having excellent light transmittance, light resistance, ink absorption, etc.

(Prior art) The inkjet recording method uses various operating principles to generate a small drop of recording liquid (drop left), which is then flown and adheres to the recording material to perform recording. It is attracting attention as a high-speed recording method.

In terms of safety and recording suitability, recording liquids for these inkjet recordings are mainly composed of a coloring agent such as a dye and an aqueous liquid medium.

Furthermore, as the recording material used in the inkjet recording method, conventional paper has generally been used.

However, as the performance of inkjet recording devices improves, such as faster recording speeds and multicolor recording, inkjet recording paper, which has a porous ink-receiving layer on the base material and has increased ink absorbency, has become available. Recording materials have been developed and are in use. Furthermore, applications other than surface image observation of paper, etc., include those that project recorded images onto a screen using optical equipment such as slides and OHP (overhead projectors) for observation, contact printers, and printed circuit board printing ( photomasks), color separation plates for making positive plates for color printing, and C for liquid crystal color displays.
MF (color mode) Conventionally, transparent negatives and positives used in optical instruments or devices using optical technology are created by taking photographs of recorded objects or objects to be recorded, or are made by transparent coatings such as plastic films. The image is created by directly recording on the recording material, but instead of this type of image forming method, by performing inkjet recording using a transparent recording material for inkjet recording, the recording speed can be increased, and the above-mentioned It is becoming possible to obtain high-resolution, high-quality, full-color recorded images that can be used in optical equipment such as.

(Problems to be Solved by the Invention) As a recording material for inkjet recording used for the above-mentioned purposes, (1) the ink absorption property is as fast as possible; (2) the ink dots are overlapped. When the ink is deposited later, it does not flow out into the dots deposited earlier. (3) The diameter of the ink dot should not be larger than necessary. (4) The shape of the ink dot should be close to a perfect circle and the surrounding area should be smooth. (5) The ink dot should have a high density and the area around the dot should be blurred. (6) In addition to the performance required for general inkjet recording, such as the ink having excellent color development, it also has translucency suitable for the intended use as mentioned above. This is necessary.

Furthermore, images recorded on such translucent recording materials are
Since it is used in various optical devices, colorants such as dyes in the recording medium tend to discolor and fade due to light.

In other words, many organic materials are generally degraded by light, especially high-energy ultraviolet rays, but when images formed in the manner described above are exposed to various light sources during use, recordings similarly deteriorate. A new problem has arisen that has not been considered much in the case of conventional surface image observation images. In particular, in the case of translucent images, high image clarity and translucency are required, so highly transparent colorants must be used, and such highly transparent colorants generally have poor light resistance. Due to the inferiority of these materials, discoloration and discoloration of images after multiple use and/or long-term use with different light sources has been highlighted as a serious problem.

The main object of the present invention is to satisfy various requirements as a recording material for inkjet recording, and to provide a recording material for slides, OHP,
An object of the present invention is to provide a recording material for inkjet recording that has excellent light resistance and does not cause a recording agent such as a dye to change color even when used in an optical device such as a contact printer.

(Disclosure of the Invention) That is, the present invention provides a recording material comprising a translucent base material and an ink receiving layer provided on the base material, in which the ultraviolet transmittance of the recording material is 20% or less. This is a recording material for inkjet recording characterized by the following.

To explain the present invention in detail, the recording material of the present invention is composed of a light-transmitting base material and an ink-receiving layer, and the light-transmitting base material is used as a support for the ink-receiving layer. As such a base material, any conventionally known base material can be used as long as it is translucent. Preferred examples include polyester resin, diacetate resin, and triacetate resin. Examples include films or plates of acrylic resin, polycarbonate resin, polyvinyl chloride resin, polyimide resin, cellophane, celluloid, and glass plates.

On the other hand, the ink-receiving layer provided on the transparent base layer as described above is the recording surface of the recording material that has the function of receiving, absorbing and fixing ink from a recording means such as a recording device or recording device during inkjet recording. It is.

Such an ink-receiving layer must be translucent in the present invention, and may be made of, for example, polyvinyl alcohol, albumin, gelatin, casein, starch, cationic starch, gum arabic, natural resins such as sodium alginate, polyamide, etc. , polyacrylamide, polyvinylpyrrolidone, quaternized polyvinylpyrrolidone, polyethyleneimine, polyvinylbilicillium halide, melamine resin, polyurethane, carboxymethyl cellulose, polyvinyl alcohol, polyester, polysodium acrylate, SBR latex, NBR latex, polyvinyl formal, poly Synthetic resins such as methyl methacrylate, polyvinyl butyral, polyacrylonitrile, polyvinyl chloride, polyvinyl acetate, phenolic resins, and alkyd resins can be mentioned, and a continuous film that is sufficiently translucent, such as one or more of these materials, can be used. Formed from a material that can be formed.

A method for forming such an ink-receiving layer is to dissolve or disperse the above-mentioned translucent polymer in a suitable solvent, add various additives as necessary to prepare a coating solution, and prepare a coating solution. The coating liquid can be applied, for example, by a roll coating method, a rod bar coach ink method, a 1 1 2 method, a 1 1 2 method, and an 3 method.

It is preferable to apply the coating onto a translucent substrate by a known method such as the coating method, and dry it quickly. Other methods may also be used, such as forming a sheet for an ink-receiving layer in advance and laminating the sheet to the above-mentioned base material.

The thickness of the ink receiving layer formed on the base material as described above is usually about 1 to 100 gm, preferably about 4 to 50 ILm. If the thickness of the ink-receiving layer exceeds the above range, the recording material will have insufficient light transmittance, while if it is below the above range, the ink-receiving layer will have insufficient absorbency, so it is not suitable. do not have.

In addition, in order to improve the ink absorbency of the ink receiving layer in the above method, for example, silica, clay, talc, diatomaceous earth, calcium carbonate, sulfuric acid, etc. may be added to the extent that does not impair the transparency of the recording material. Calcium, barium sulfate, aluminum silicate, synthetic zeolite, alumina,
Fillers such as zinc oxide, Lido:Bonn, Sachinwhite, etc. can also be dispersed in the ink-receiving layer.

The basic structure of the recording material for inkjet recording of the present invention is as described above, and the feature of the recording material of the present invention is that in the recording material as described above, the recording material itself can be used for various purposes as described above. The first feature is that the recording material is sufficiently translucent to be compatible, and the second feature is that the ultraviolet transmittance of the recording material is 20% or less.

The above-mentioned first feature of the present invention is achieved by using the light-transmitting base material and the light-transmitting ink-receiving layer as described above. The main use of the recording material in the present invention is to utilize transmitted light, and therefore the recording material must have sufficient light transmittance. For example, when observing a projected image on an OHP, in order to obtain a clear and easy-to-see image with a high mantle trust between the recorded and non-recorded areas, it is necessary to make sure that the non-recorded areas in the projected image are bright, that is, the straight line of the recording material. It is required that the light transmittance be at a certain level or higher. In an OHP test chart test, in order to obtain an image suitable for the above purpose, the linear light transmittance of the recording material should be 2% or more, and preferably 10% to obtain a clearer image. or more is required. Therefore, a recording material suitable for this purpose must have a linear light transmittance of 2% or more.

The linear transmittance T (%) here refers to the amount of light incident perpendicularly to the sample, transmitted through the sample, and at least 8
Measure the spectral transmittance of straight light that passes through the light-receiving side slit on the extension line of the incident optical path separated by more than cm and is received by the detector using, for example, a UV200S self-recording spectrophotometer (manufactured by Shimadzu Corporation). Then, the Y value of the color tristimulus value is calculated from the measured spectral transmittance, and the value is calculated from the following formula.

T=Y/Y, Place an integrating sphere behind the sample to measure the light transmittance, including diffused light.), opacity (place a white and black backing on the back of the sample and calculate the ratio), etc. This method is different from the method of evaluating translucency using diffused and diffused light. , The problem with equipment that uses optical technology is the behavior and transmission of straight light, so when evaluating the translucency of liquid fertilizer and silver materials to be used in these equipment, it is necessary to It is especially important to measure the straight-line transmittance of the material. .

A second feature of the present invention is that the ultraviolet transmittance of the transparent recording material as described above is 20% or less. The second characteristic of such unreleased... is, as the most preferable aspect,
In forming the ink-receiving layer as described above, a material that reduces the transmission of ultraviolet rays (that is, absorbs ultraviolet rays) is included in the ink-receiving layer. Suitable additives include phenyl salicylate, p-t-butylphenyl salicylate, p-octylphenyl salicylate, 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy -4-
Methoxy-2'-carboxybenzophenone, 2-hydroxy-4-methoxy-5-sulfobenzophenone trihydrate, 2-human, roxy-4-octoxybenzophenone, 2-hydroxy-4-octadecyloxybenzophenone, 2-hydroxy- 4-methoxybenzophenone-5-sulfonic acid, 2-hydroxy-3,6-dichloro-4-alkyloxybenzophenone, 2-hydroxy-4-dodecyloxybenzophenone, 2.2'-dihydroxy-4-methoxybenzophenone, 2. 2・-,3do,,□,-4.4・-,,,,Yau
1benzophenone, 2.2',4.4''-tetrahydroxybenzophenone, radium 2,2'-dihydroxy-4,4'-dimethoxy-5-sulfobenzophenone, 4-F decyloxy-
2-hydroxybenzophenone, 5-chloro-2-hydroxybenzophenone, 2-(2
"-Hydroxy-4'-octoxyphenyl)benzotriazole, 2-(2'-hydroxy-3'-prio-butyl-5'-methylphenyl)-5-chlorobenzotriazole, 2-(2'-hydroxy- Octylphenyl 3'-tert-butyl-5'-propionate)-5-chlorobenzotriazole.

2-ethylhexyl-2-cyano-3,3'-diphenylacrylate, ethyl-2-cyano-3,3'-diphenylacrylate, nickel bis(octylphenyl) sulfite [2,2
”-thiobis(4-t-octylphenolate)]-]
n-butylamine nickel nickel complex-3
, 5-di-t-butyl-4-hydroxybenzyl-phosphate monoethylate, nickel-dibutyldithiocarbamate, resorcinol monobenzoate, hexamethylphosphoryl triamide, 2.4.5-trihydroxybutylphenone, di-p-
2-oxy-4-(2-oxy-3- Methacryloxy)propoxybenzophenone, diphenylmethylenecyanoethyl acetate, and the like. Any of these additives can be used alone or as a mixture in the present invention, but they should be selected by first considering their compatibility with the material forming the ink-receiving layer as described above.

Furthermore, when a relatively high temperature is used to form the ink-receiving layer (for example, in a hot-melt coating method), the heat resistance of the above-mentioned additives should also be taken into consideration. Such a selection can be easily made by a person skilled in the art using ordinary compatibility tests, light resistance tests, etc. In addition, in order to reduce the ultraviolet transmittance of the recording material to 20% or less, the amount of additives to be used cannot be definitively stated depending on the type and combination of additives, but in general, it is necessary to Approximately 0.1-10% by weight
This is the proportion that accounts for

In another embodiment, after forming an ink-receiving layer on a transparent substrate, the surface of the ink-receiving layer is coated with a binder material (for example, a transparent polymer as described above) that does not prevent the ink-absorbing property of the ink-receiving layer. An ultraviolet blocking layer may be formed by applying an additive. Furthermore, when using a recorded recording material, if the light beam to be used is incident on the back side of the recording material, the above-mentioned additives may be included in the base material itself during manufacture of the base material. Alternatively, a UV blocking layer made of the above additives may be formed on at least one surface of the base material using an arbitrary binder. In such a case, the binder does not necessarily have to be a hydrophilic binder. , or a conventional hydrophobic binder.

Furthermore, it is also preferable that the above embodiments be combined, for example, that both the base material and the ink receiving layer have an ultraviolet transmittance of 20% or less.

The above embodiments are merely examples of the present invention, and it is natural that other methods may be used as long as the second feature of the present invention is achieved.

In addition, the transmittance of ultraviolet rays referred to in the present invention refers to wavelength 3
It means the transmittance of ultraviolet light of 50 nm.

The present invention has been described above by exemplifying typical aspects of the recording material of the present invention, but of course the recording material of the present invention is not limited to these aspects.

Also, in any of the embodiments, the ink 1 receiving layer contains a dispersant, a fluorescent dye, a pH adjuster, a dye! foaming agent,
Various known additives such as lubricants, preservatives, surfactants, etc. can be included.

Note that the recording material of the present invention does not necessarily have to be colorless, and may be a colored recording material.
(see the same No., the specification of the same No.), by forming fine irregularities on the surface and/or back surface of the recording material of the present invention as described above, or by adhering powder to the surface, Fixability of the recording liquid of the recording material of the present invention,
Other performances such as color development, stability, and prevention of blocking between recording materials can be further improved.

According to the present invention as described above, the recording material of the present invention has the above-described structure, so that the ink-receiving layer has particularly excellent ink absorption and ink fixing properties, and also satisfies the above-mentioned required performance. Even if recording liquids of different colors adhere to the same spot repeatedly within a short period of time, there will be no bleeding or seeping phenomenon, resulting in high-resolution, clear, and excellent color development. A water-resistant image can be obtained. Moreover, since the recording material of the present invention is translucent as a whole, it can be used for observation by projecting a recorded image onto a screen using an optical device such as a slide or OHP, or for creating a positive plate for color printing. It can be applied to applications other than conventional surface image observation, such as color separation plates, CMF used in color displays such as liquid crystals, etc.

Furthermore, since the recording material of the present invention has an ultraviolet transmittance of 20% or less, the recording material will not be colored even when used in various applications that utilize transmitted light as described above. It has the remarkable effect of being able to sufficiently withstand long-term exposure to light without fading, discoloration or other deterioration of dyes and the like caused by light. On the other hand, with conventional recording materials, characters, symbols, patterns, etc. on the recording material change color and fade due to repeated use or long-term use.

” Hereinafter, the present invention will be explained in more detail with reference to Examples. In the text, parts are based on weight.

Example 1 A polyester film (manufactured by Toshi) with a thickness of 75 parts m was used as a translucent base material, and the following coating composition C was applied as an ink-receiving layer on this film after drying. Coating was performed using a bar coater method so that the layer thickness was 10 gm,
This was dried at 60° C. for 20 minutes to obtain a translucent recording material of the present invention that can be used for applications that utilize transmitted light from recorded images.

Composition A 2-ethylhexyl-2-cyano-3,3'-diphenylcyanoacrylate (trade name UVI) IUL-1539
GAF) 20 parts Ethanol 80 parts Composition B Polyvinyl alcohol? (Product name: PVA-210 manufactured by Kuraray) 10 parts water
90 parts Composition C 1 part Composition A 99 parts An on-demand inkjet recording head (inkjet recording head) in which four colors of ink having the following composition are used on the recording material of the present invention to eject the ink using a piezo vibrator. Inkjet recording was performed using a recording apparatus having an ejection orifice diameter of 50 #Lm, a piezo vibrator drive voltage of 60 V, and a frequency of 4 KHz to obtain a recorded image.

Yellow ink (composition) C, 1, Direct Yellow 86 2 parts diethylene glycol 15 parts ethylene glycol 10 parts water 75 parts Red ink (composition) C, 1, Acid Red 35 2 parts diethylene glycol 15 parts ethylene glycol 10 parts water 75 parts Blue ink (Composition) C, 1, Direct Blue 86 2 parts Diethylene glycol 15 parts Ethylene glycol 10 parts Water 75 parts Black ink (Composition) C, R, Direct Black 19 2 parts Diethylene glycol 15 parts Ethylene glycol 10 parts Water 75 parts Thus The obtained recorded images were tested for the following five items to evaluate the recording suitability of the recording material and the suitability for optical equipment.

(1) Ink fixability is after inkjet recording.

The recorded matter was left at room temperature, and the time required for the ink to dry sufficiently without adhering to the finger when touching the recorded area with the finger was measured and evaluated.

(2) Ink dot density was measured for black dots using a Sakura microdensitometer, PDM-5 (manufactured by Konishi Roku Shashin Co., Ltd.).

(3) Linear light transmittance is measured in order to evaluate light transmittance as one of the evaluations of optical suitability. distance of 9 cm) was calculated from the spectral transmittance measured using a UV-2003 type self-recording spectrophotometer (manufactured by Takasu Seisakusho).

(4) Ultraviolet transmittance was measured using a UV-2003 self-recording spectrophotometer (manufactured by Takasu Seisakusho), keeping the distance from the sample to the light-receiving side within 1 cm.

(5) The light resistance of the recording material is measured using a xenon fade meter.
(model FAL-25AX-HC, manufactured by Suga Test Instruments) After irradiation for 100 hours, the zero color difference was determined by the color difference with the unirradiated sample using a colorimetric color difference meter (model ND-1001DP, manufactured by Nihon Heavy Industries).

The obtained evaluation results are shown in Table 1.

Example 2 Polycarbonate film (thickness 1
00gm, manufactured by Kijin), the following coating composition was coated on this film using a bar coater method so that the thickness of the coating layer after drying was 15JLm, and this was coated at 80℃ for 10
The transparent recording material of the present invention was obtained by drying under drying conditions for 1 minute.

Coating composition D Polyvinylpyrrolidone (PVP K-90GAF) 20 parts 2,2'-dihydroxy-4,4'-dimethoxybenzophenone (CYASORB UV-24ACC) 0.4 parts Methanol 80 parts The obtained recording material was also subjected to inkjet recording in the same manner as in Example 1, and the recording characteristics were evaluated in the same manner as in Example 1. The results are shown in Table 1.

Comparative Example 1 The same method as Example 1 was used, except that no additive was added to reduce ultraviolet transmittance.
・A recording material for comparison was obtained from 1. Inkjet recording similar to that in Example 1 was performed on this recording material, and the recording characteristics were evaluated in the same manner as in Example 1. The results are shown in Table 1.

Comparative Example 2 A comparative recording material was obtained in the same manner as in Example 2, except that no additive for reducing ultraviolet transmittance was added. Inkjet recording similar to that in Example 1 was performed on this recording material, and the recording characteristics were evaluated in the same manner as in Example 1. The results are shown in Table 1.

As explained above, and as is clear from Table 1,
The ultraviolet transmittance of the recording material of the present invention is extremely low, and the light fastness of each color is significantly improved.

Furthermore, the recording material of the present invention has sufficient translucency, and in addition to being capable of high-speed printing and multicolor printing by inkjet recording, the recorded image can be used for purposes other than surface observation, that is, recorded images. Transmission of 1＼ It is suitable as a recording material for use in optical equipment that utilizes light.

One straddle 1↓ m-1 example- 2 2 minutes 82 15-mu LL prisoner q 1.1 1. [UV'at350m'; a IX-resistant U℃0-A
JE 0.5 0.4 - nΩ resistance ME 1.8 5. (-Resistance] J1Q Hi-Technology-1,01,1 -Resistance nΩ■L 鉦dan-0,70,f -Comparative Example 2 2 3 minutes 2 minutes 81% 78 1.1 1.0 73z 8 Show 0 .6 0.5 G, 0 32.0 1.5 7.0 1.0 B, 0

Claims (1)

[Claims] (1) A recording material comprising a translucent base material and an ink receiving layer provided on the translucent base material, characterized in that the ultraviolet transmittance of the recording material is 20% or less. Recording material for inkjet recording.