GB2139958A - Ink-jet printing - Google Patents

Abstract

A recording member having good transparency and ink recording property for ink jet recording and subsequent optical use such as in an overhead projector, is composed of a transparent or translucent base and an ink absorbing layer, and having a linear transmission factor of 10% and above.

Description

SPECIFICATION Recording member This invention relates to a recording member for use in the ink jet recording, and, more particularly, it is concerned with a recording member having excellent transparency and ink absorption.

A recording system for effecting recording with use of recording liquid has been very old and common in inscription with use of fountain pens, etc. Of recent, there has been developed the so-called "ink jet recording system", which also uses the recording liquid.

The ink jet recording system is to effect recording of image by producing droplets of the recording liquid based on various operating principles, and then causing the droplets to fly toward, and adhere to, the recording member, on which desired images are to be recorded. This recording system has drawn attention of all concerned in its characteristic of low noise, high speed recording, and polychromatic recording. For the recording liquid, there has been used mainly an aqueous type recording liquid from the aspects of safety in, and adaptability to, the recording.

For the recording member to be used for this ink jet recording system, there has so far been utilized generally plain paper. With improvement in performance of the ink jet recording apparatus such as the high speed recording or the polychromatic recording, new types of the recording member have been developed and are used, such as the one called "ink jet recording paper" composed of a base and a porous ink absorbing layer provided on the base so as to increase ink absorbing property of the paper.

Such recording member is required to satisfy the undermentioned conditions in order to produce recorded images of high resolution and high image quality by the ink jet recording system: 1) it absorbs ink as quickly as possible; 2) when the ink dots are laid over one after the other, it does not permit the later dot to run out over the earlier dot; 3) it does not permit the ink dot to expand its diameter more than necessary; 4) it maintains the shape of the ink dot in a substantially true circle, hence smooth contour; 5) it maintains the ink dot in high density, hence unobscured circumference; and 6) it assists good color-forming property of the ink.

In the ink jet recording system, there has also been used so far another type of recording member, on which to obtain a recorded image for surface image observation. With improvement in the ink jet recording technique and dissemination of the ink jet recording apparatus, such recording member has become considered to have its utility for other purposes by taking advantage of the characteristics in the ink jet recording.

For its use other than the surface image observation, there may be enumerated the following: for observation of a recorded image on a screen by projecting it through an optical apparatus such as a slide projector, an overhead projector (OHP), etc.; as a photo-mask for a contract printer, a printed circuit wiring board, etc.; as a color-separation plate for production of a positive plate for color printing; as a color mosaic filter (CMF) for color display with liquid crystal; and so forth.

Transparent negatives and positives for use in the optical apparatuses and appliances or those apparatuses utilizing the optical technique are manufactured by taking photograph of those recorded matters or objects for recording, or by direct recording of these recorded matters or objects for recording onto a transparent recording member made of plastic film, etc. Besides these conventional methods, the ink jet recording system using a transparent recording member for the ink jet recording makes it possible to effect the recording at an increased speed and to obtain a recorded image in full-color having high resolution and good image quality, which can be used in such optical apparatuses and appliances as mentioned above.

For use in such purpose, the recording member should possess transparency suited for the purpose of its use in addition to those requirements on the recording member for the ink jet recording as enumerated in the foregoing.

The present invention provides a recording member for ink jet recording, which comprises: a transparent or translucent base, and an ink absorbing layer provided on said base, said recording member having a linear transmission factor of at least 10%.

It is possible by means of the invention to provide a recording member for ink jet recording which can be used for other purposes than the surface image observation, such as, for example, in slide projectors, overhead projectors, contact printers, and other optical apparatuses and appliances, and which meets all the requirements on the recording member for the ink jet recording.

The linear transmission factor of the recording medium is preferably at least 30%.

Preferred features such as specific materials for the base and ingredients and their mixing ratio for the ink absorbing layer of the recording member according to the present invention will become more apparent and understandable from the following detailed description and specific examples.

In the following, the present invention will be described in detail.

The transparent or translucent base for the recording member of the present invention may suitably be selected from the following: polyester, cellulose diacetate, cellulose triacetate, acrylic type polymers, Cellophane (a trade name for regenerated cellulose), Celluloid (a trade name for a plastic made from comphor and cellulose nitrate), polyvinyl chloride, polycarbonate, and other plastic materials in sheet or plate; and glass plate as well.

The ink absorbing layer for the recording member of the present invention may be manufactured by use of the following materials capable of forming on the abovementioned base a continuous coating film having sufficient transparency: starch, casein, albumin, gum arabic, sodium alginate, polyvinyl alcohol, polyacryl amide, carboxymethyl cellulose, sodium polyacrylate, ionomer resin, polyvinyl acetate, and so forth. These materials, singly or in combination, are dissolved in a solvent depending on necessity, and the solution is coated on the base, followed by drying or cooling it.Depending on situations, one or more kinds of inorganic pigments as a filler may be dispersed in the above-mentioned ink absorbing layer within such a range that does not hinder transparency of the recording member with a view to increasing the absorbing and fixing properties of the recording liquid to the recording member with a view to increasing the absorbing and fixing properties of the recording liquid to the recording member by forming a porous structure on the surface of the ink absorbing layer. Examples of such filling material are: pulverized powder of silica, clay, talc, diatomaceous earth, calcium carbonate, calcium sulfate, titanium oxide, zinc oxide, satin white, aluminium silicate, lithopone, alumina, zeolite, and others.

The ink absorbing layer may be coated on the base by various known methods such as roll-coating method, blade-coating method, air-knife coating method, rod-bar coating method, hot-melt coating method, and so forth.

The term "linear transmission factor (T (%))" as referred to herein is a value obtained by first measuring a spectral transmission factor of rectilinear light which is perpendicularly impinged on a sample, passes through the sample, further passes through a light-receiving slit situated at a position away from the sample by at least 8 cm and on the extension of the incident light path, and is received into a detector; then by calculating a value Y of the tristimulus values of color from the spectral transmission factor as measured; and by finally calculating the linear transmission factor from the following equation: T=Y/Yoxl0O (1) (where: T denotes the linear transmission factor; Y represents a Y value of a sample; and Yo indicates a Y value of a blank).

The linear transmission factor can be measured by use of, for example, a self-recording type spectrophotometer, Model 323 (manufactured by Hitachi Ltd., Japan).

Accordingly, the linear transmission factor as used in the present invention is with respect to the rectilinear light, so that it is different from evaluation of transparency of an object by use of diffused light in terms of diffuse transmission factor (to find out a transmission factor of a sample, inclusive of diffused light, by providing an integrating sphere at the back side of the sample) or non-transparency (to find out a degree of non-transparency of a sample from a ratio of light transmission between a white liner and a black liner placed on the rear surface of the sample).Since it is the behaviour of the rectilinear light that matters in those apparatuses and appliances utilizing the optical technique, the finding of the linear transmission factor of the recording member is of particular importance in evaluating the transparency of the recording member to be used in such apparatuses and appliances.

When observing a projected image by use of an overhead projector (OHP), for instance, it is necessary that a non-recorded portion of the projected image is sufficiently bright, i.e., the linear transmission factor of the recording member is at a certain level or higher, in order to obtain a very clear image of high contrast between the recorded portion and the non-recorded portion thereof. According to tests conducted by use of a test chart for the overhead projector, it is required that the linear transmission factor of the recording member be 10% or higher to obtain an image suited for the abovementioned purpose, and preferably it be 30% or higher to obtain a clearer image. Consequently, the recording member meeting the purpose of the present invention should possess its linear transmission factor of 10% or higher.

The recording member of the present invention can also be used as the chromatic recording member by colouring the transparent base or the ink absorbing layer.

As described in the foregoing, the recording member for the inkjet recording constructed with the transparent base and the ink absorbing layer provided on the base is excellent in its ink absorbing property, and is therefore adapted to be used for high speed recording and polychromatic recording, hence it is highly suitable as the recording member that can be used in various optical apparatuses and appliances such as slide projectors, OH P's, contact printers, and so forth.

In order to enable those persons skilled in the art to readily put this invention into practice, the following several examples are presented. It should, however, be noted that the invention is not limited to these examples alone, but changes and modifications in the materials and ingredients used may be made by them within an ambit of the invention as recited in the appended claims.

Example 1 As the transparent base, use was made of cellulose triacetate film of 80 Fm thick (a product of Fuji Photo Film Co., Ltd., Japan), over which the ink absorbing layer of the undermentioned composition was coated by the bar-coating method is such a manner that the coating after its drying may become 20 Fm thick, followed by drying the applied coating in a drying furnace for one hourand at a temperature of 80"C to give a recording member 100m thick.

Composition of Ink Absorbing Layer Polyvinyl Alcohol, "PVA-117" 10 wt. parts (a product of Kuraray K.K., Japan) Pulverized Silica, 0.1 wt. part "NIPSIL E 200" (a product of Nippon Silica Kogyo K.K.) Water 90 wt. parts With the thus manufactured recording member, the ink jest recording was carried out to obtain the recorded matter by use of aqueous ink in four colors of yellow, red, blue, and black, as shown in Table 1 below, and by means of a recording apparatus having an "on-demand" type ink jet recording head to eject the recording liquid by a piezo-vibrator (an orifice diameter of 50 Wm; a piezo-vibrator drive voltage of 60 V; and a drive frequency of 4 KHz).

TABLE 1 Composition Kind (Dyestuff} Dyestuff Diethylene Glycol Water Yellow Ink 2 wt. parts 15 wt. parts 85 wt. parts Red Ink (C. I. Acid Red 92) 2 " 15 " 85 Blue Ink (C. I. Direct Blue 86) 2 " 15 " 85 Black Ink (C. I. Direct Black 19) 2 " 15 " 85 Adaptability to recording of the recording member for the ink jet recording was evaluated by measuring the ink fixing time and the dot density, while its adaptability to the optical apparatus was evaluated by measuring the linear transmission factor and by suitability test with the OHP as the representative optical apparatus.

The ink fixing time was measured in such a manner that, after completion of the ink jet recording, the recorded matter was left under a room temperature to perfectly dry and fix the ink on the recording member so that it may not stick to a finger when touched on the recorded portion, thereby finding a time from completion of the recording to drying-up of the ink.

The dot density was measured for the black ink dots by use of "SAKURA Micro-Densitometer, PDM-5" (manufactured by Konishiroku Photo Industries, Co. Ltd.).

The linear transmission factor was found from the afore-mentioned equation (1) using the self-recording spectrophotometer, Model 323 (manufactured by Hitachi, Ltd. Japan), wherein a sample was set apart by a distance of approximately 9 cm from a light-receiving window to measure the spectral transmission factor.

The adaptability to the OHP was evaluated by projecting the recorded matter on the screen using the OHP, and observing the projected image with naked eyes, the evaluation being in accordance with the following criteria.

O . . . The non-recorded portion is bright; the recorded portion has high optical density (O.D.); and the projected image is clear and has high contrast.

A . . . The non-recorded portion becomes somewhat dark; the recorded portion has a slightly lowered O.D.; and the projected image has a lowered contrast.

X . . . The non-recorded portion becomes dark; the recorded portion has very low O.D.; and the projected image is dark and difficult to observe, or the recorded matter appears so dark that both recorded and non-recorded portions are indistinct.

From the above results, general evaluation was made as to whether the recording member served the purpose of the present invention, or not. Table 2 below indicates these results.

Example 2 As the transparent base, use was made of a "Mylar" film of 80 Fm thick treated for hydrophilicity (manufactured by l.C.I., U.K.), over which the ink absorbing layer of the undermentioned composition was coated by the bar-coating method is such a manner that the coating after its drying may become 201jim thick, followed by drying the applied coating in a drying furnace for 30 minutes at a temperature of 30"C to give a recording medium 1 00 > m thick.

Composition of Ink Absorbing Layer Albumin (Egg white albumin 10 wt. parts manufactured by Tokyo Kasei Kogyo K.K.) Water 90 wt. parts Using the thus obtained recording member, the ink jet recording was carried out in the same manner as in Example 1 above to thereby obtain the recorded matter. Further, the evaluation on adaptability to the ink jet recording of the recording member was done in accordance with the method as employed in Example 1 above, with the results being shown in Table 2 below.

Example 3 The same hydrophilic-treated "Mylar" film as that used in Example 2 above was utilized as the transparent base, and then the ink absorbing layer of the under-mentioned composition was coated over the base by means of the hot-melt coating method, followed by cooling the coated layer at a room temperature.

Composition of Ink Absorbing Layer lonomer Resin 100 wt. parts ("SURLYN" - a product of E. I. du Pont de Nemours & Co., U.S.A.) C. I. Pigment Blue 0.1 wt. part ("FASTGEN BLUE 5030L" - a product of Dai-Nippon Ink Co. Ltd.) A recording member having a colored ink absorbing layer was obtained.

Using the thus obtained recording member, the ink jet recording was carried out in the same manner as in Example 1 above to thereby obtain the recorded matter. The adaptability of this recording member to the ink jet recording was evaluated in accordance with the method as set down in Example 1 above.

Comparative Example 1 The same hydrophilic-treated "Mylar" film as that used in Example 2 above, without the ink absorbing layer having been provided thereon, was utilized as the recording member, and the ink jet recording was effected on it in accordance with the steps as set down in Example 1 above. The adaptability of the recording member to the ink jet recording and the optical apparatus was evaluated, the results of which are shown in Table 2 below.

Comparative Example 2 As the recording member of low transparency, use was made of tracing paper for drawing, and the ink jet recording was done on it in accordance with the steps as set down in Example 1 above. The adaptability of the recording member to the ink jet recording and the optical apparatus was evaluated, the results of which are shown in Table 2 below.

Comparative Example 3 Using an OHPfilm available in general market ("NP-DRY TRANSPARENCY" - Canon Hanbai K.K., Japan), the ink jet recording was conducted. The adaptability of this recording member to the ink jest recording and the optical apparatus was evaluated in the same manner as laid down in Example 1 above, the results of which are shown in Table 2 below.

Comparative Example 4 The same OHP film as that used in Comparative Example 3 above was laminated in four layers, and was used as the recording member. The ink jet recording was carried out on it in the same manner as in Example 1 above. Then, adaptability of this recording member to the ink jet recording and the optical apparatus was evaluated with the results being as shown in Table 2 below.

Comparative Example 5 The same OHP film as that used in Comparative Example 3 above was laminated in five layers, and was used as the recording member. The ink jet recording was carried out on it in the same manner as in Example 1 above. Then, adaptability of this recording member to the ink jet recording and the optical apparatus was evaluated with the results being as shown in Table 2 below.

Example 4 As the transparent base, use was made of the same hydrophilic-treated "Mylar" film as that used in Example 2 above, over which the ink absorbing layer of the under-mentioned composition was coated by the bar-coating method in such a manner that the coated film after its drying may become 10m thick, followed by drying the applied coating in a drying furnace for 10 minutes at a temperature of 50"C.

Composition of Ink Absorbing Layer Polyvinyl Alcohol, PVA-217 10 wt. parts (a product of Kurarary K.K., Japan) Water 90 wt. parts Using the thus obtained recording member, the ink jet recording was carried out in the same manner as in Example 1 above to thereby obtain the recorded matter. After this, adaptability of the recording member to the ink jet recording and the optical apparatus was evaluated in accordance with the method as employed in Example 1 above, with the results being shown in Table 2 below.

Example 5 As the transparent base, use was made of the same hydrophilic-treated "Mylar" film as that used in Example 2 above, over which the ink absorbing layer of the under-mentioned composition was coated by the bar-coating method in such a manner that the coated film after its drying may become 15 ijm thick, followed by drying the applied coating in a drying furnace for 15 minutes at a temperature of 50"C.

Composition of Ink Absorbing Layer Polyvinyl Alcohol, PVA-205 20 wt. parts (a product of Kuraray K.K., Japan) Cl. Direct Blue 86 0.5 wt. part Water 80 wt. parts Using the thus obtained recording member, the ink jet recording was carried out in the same manner as in Example 1 above to thereby obtain the recorded matter. After this, adaptability of the recording member to the ink jet recording and the optical apparatus was evaluated in accordance with the method as set down in Example 1 above, with the results being shown in Table 2 below.

TABLE 2 Linear Ink Fixing Transmission Dot Adaptability General Time Rate (%) Density to OHP Evaluation Example 1 10 minutes 32 1.0 0 0 Example2 15 minutes 78 1.1 0 0 Example 3 20 minutes 45 0.9 0 0 Comparative 7 days 85 1.2 0 X Example 1 Comparative 1 day 1 0.6 X X Example 2 Comparative 7 days 62 1.0 O X Example 3 Comparative 7 days 15 1.2 0 X Example 4 Comparative 7 days 9 1.2 A X Example 5 Examples4 3 minutes 81 1.1 0 0 Example5 3 minutes 12 0.9 0 0

Claims (4)

1. A recording member for ink jet recording, which comprises: a transparent or translucent base, and an ink absorbing layer provided on said base, said recording member having a linear transmission factor of at least 10%.

2. A recording member according to Claim 1, which has a linear transmission factor of at least 30%.

3. A recording member according to Claim 1 or Claim 2, wherein the ink absorbing layer comprises one or more of starch, casein, albumin, gum arabic, sodium alginate, polyvinyl alcohol, polyacrylamide, carboxymethyl cellulose, sodium polyacrylate, ionomer resins and polyvinyl acetate.

4. A recording member for ink jet recording, substantially as herein described with reference to any one of the Examples.