JPS62233284A - Recording medium - Google Patents

Abstract

PURPOSE:To obtain a recording medium for ink jet recording which is superior in the clarity of a recording image, by a method wherein an ink accepting layer contains a product of an addition reaction and/or a condensation reaction of polyvinyl alcohol. CONSTITUTION:As a compound having a reactivity with a hydroxyl group in a PVA, an aldehyde compound, especially an alkyl aldehyde compound containing an aromatic substance such as a benzyl aldehyde, is preferably used. The PVA being modified by the above aldehyde having an aromatic group retains sufficient ink accepting properties even under a low-humidity condition in ambient atmosphere and is free from a surface tackiness even under a high- humidity condition. An ink accepting layer as the above is formed by a method in which the aforesaid PVA-modified substance is dissolved or dispersed in a suitable solvent in a simple state or a mixed state with another polymer to prepare a coating liquid, and in which the coating liquid is applied on a light-transmitting substrate by a roll coating method or an air knife coating method, thereafter being dried immediately.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention is suitable for recording with various writing instruments that use water-based ink, recording devices such as Venn plotters, etc., and is particularly suitable for inkjet recording systems that use water-based ink. Regarding the recording material to be used, a recording material that is particularly excellent in ink receptivity, clearness of recorded images, water resistance, etc. is selected.

(Prior art) The inkjet recording method uses various ink ejection methods, such as an electrostatic suction method, a method that applies mechanical vibration or displacement to the ink using a piezoelectric element, and a method that applies mechanical vibration or displacement to the ink using a piezoelectric element. Recording is performed by generating and flying small droplets of ink using methods such as using
This method is attracting attention as a method that generates little noise and can perform high-speed printing and multicolor printing.

Ink for inkjet recording methods is safe,
From the viewpoint of recording characteristics, those containing water as a main component are mainly used, and polyhydric alcohols and the like are often added to prevent nozzle clogging and improve ejection stability.

The recording material used in this inkjet system has conventionally been a recording material consisting of a base material called ordinary paper or inkjet recording paper on which a porous ink-receiving layer is provided. However, as the performance of inkjet recording apparatuses increases and becomes more widespread, such as faster recording speeds and multicolor recording, more advanced and wide-ranging properties are being required of recording materials. In other words, the recording material for inkjet recording to obtain high-resolution, high-quality recorded images must (1) be able to receive ink as quickly as possible on the recording material, and (2) have overlapping ink dots. (3) Ink droplets do not spread on the recording material and the diameter of the ink dot does not become larger than necessary, (4) ) The shape of the ink dot should be close to a perfect circle, and the circumference should be smooth.

(5) It is necessary to satisfy various basic requirements such as high OD (optical density) of the ink dot and no blurring around the dot.

Furthermore, in order to obtain high-resolution recorded image quality comparable to color photography using the multicolor inkjet method, in addition to the above-mentioned required performance, (6) the coloring components of the ink must have excellent color development; 7) The ink fixation properties are particularly excellent, as the same number of droplets as the number of ink colors may adhere to the same spot, (8) The surface must be glossy, (9) Whiteness A high level of performance, etc., is required.

In addition, images recorded by the inkjet method have traditionally been used exclusively for surface image observation, but as the performance of inkjet recording devices improves and becomes more widespread, there is a demand for recording materials suitable for purposes other than surface image observation. Other uses for recording materials other than the 0 surface image observation that are becoming increasingly popular include slides and 0 surface images.
Optical equipment such as HP (overhead projector) is used to project recorded images onto a screen and observe those images, color separation plates when creating positive plates for color printing, liquid crystals, etc. Examples include CMF (color mosaic filter) used in color displays.

When a recording material is used for surface image observation, the diffused light of the recorded image is mainly observed, whereas for recording materials used in these applications, the problem is mainly the transmitted light of the recorded image. Become. Therefore, it is required to have excellent light transmittance, especially linear light transmittance, in addition to the above-mentioned performance requirements of the general recording material for inkjet recording.

(The problem that the invention is trying to solve) However,
The reality is that there is still no known recording material that satisfies all of these required performances.

In addition, many conventional recording materials for surface image observation use a method in which a porous ink-receiving layer is provided on the surface, and the ink is received in the porous voids to fix the recording material. The surface of the recording material was not glossy due to the nature of the recording material. On the other hand, when the surface of the ink-receiving layer is non-porous, non-volatile components such as polyhydric alcohols in the ink remain on the surface of the recording material for a long time after recording, and the drying and fixing time of the ink is long. There are disadvantages in that clothing may get dirty or the recorded image may be damaged if it comes into contact with the recorded image.

An object of the present invention is to provide a recording material for inkjet recording that is particularly excellent in ink receptivity and the clarity of recorded images.

Another object of the present invention is to provide an inkjet recording material having a porous ink-receiving layer on the surface, which can form a recorded image particularly excellent in ink receptivity, ink color development, resolution, and water resistance. The goal is to provide recording materials.

Another object of the present invention is to provide a recording material for full-color inkjet recording that has excellent ink receptivity, sharpness of recorded images, water resistance, and surface gloss.

Still another object of the present invention is to use an optical device such as a slide or an OHP to project a recorded image onto a screen for observation, a color separation plate when creating a positive plate for color printing, or a liquid crystal display. An object of the present invention is to provide a recording material for inkjet recording that can be used for transmitted light observation such as CMF used in color displays.

The above and other objects of the invention are achieved by the following invention.

(Disclosure of the Invention) That is, the present invention provides a recording material comprising a base material and an ink receiving layer provided on the base material, in which the ink receiving layer is made of polyvinyl alcohol (hereinafter simply referred to as PVA).
This is a recording material characterized by containing an addition and/or condensation reaction product of.

To explain the present invention in detail, the recording material of the present invention is mainly characterized in that its recording surface contains an addition and/or condensation reaction product of PVA, and the object of the present invention is mainly achieved thereby. It is something that can be achieved.

Conventionally, PVA has been used to form the ink receiving layer of recording materials for inkjet systems, but the following problems have arisen with these conventional recording materials.

(1) When the humidity of the surrounding atmosphere decreases, the water content of the ink-receiving layer decreases, and the ink-receptivity of the ink-receiving layer decreases significantly due to hydrogen bonds between PVA.

(2) Conversely, when the surrounding atmosphere is under high humidity conditions, the ink-receiving layer absorbs moisture and the surface becomes sticky, causing problems such as image disturbance and blocking.

(3) The same problem as above occurs when recording materials are stored for a long period of time.

As a method to solve these problems, a method of crosslinking PVA has been considered, but in this case, the ink receptivity of the ink receiving layer is significantly reduced, and PVA with a low degree of saponification is used. When used, the ink receptivity similarly decreased significantly, making it unsuitable for use.

Furthermore, methods of cationically or anionically modifying PVA have been considered, but such methods have problems with the copolymerizability of the cationic monomers and anionic monomers used with vinyl acetate, and with the saponification. However, there were problems with the stability of the monomer or copolymer, and an ink-receiving layer with satisfactory performance could not be formed.

As a result of intensive research to solve various problems related to the use of PVA as described above, the present inventor discovered that the specific modified PV
It has been discovered that the various problems mentioned above can be solved at the same time by using A in forming the ink-receiving layer.

The recording material of the present invention generally consists of a base material as a support and an ink-receiving layer provided on the surface thereof.For example, as a particularly preferred embodiment, (1) both the base material and the ink-receiving layer are (2) The surface of the ink-receiving layer is smooth; and (3) the ink-receiving layer is porous.

Further, each ink receiving layer may also function as a support at the same time.

To explain the present invention in more detail using some of the preferred embodiments as representative examples, the PVA addition and/or condensation reaction product that mainly characterizes the present invention is PV
It is a product obtained by addition and/or condensation reaction of a compound reactive with the hydroxyl group in A and PVA.

Examples of compounds that are reactive with the hydroxyl group of PVA include aldehyde compounds, carboxyl compounds, epoxy compounds, isocyanate compounds, acid anhydrides, N-methylol compounds, activated vinyl compounds, and polyvalent metal compounds. The addition and/or condensation reaction products of such compounds and PVA are all known, and the present invention uses the products produced by such reactions to form the ink-receiving layer of the recording material. This is the main feature.

The PVA used in the present invention is a vinyl acetate polymer or a copolymer of vinyl acetate and other copolymerizable monomers, such as ethylene, propylene, vinyl chloride, (meth)acrylic acid, or their esters, which is prepared by acid saponification. Alternatively, it can be obtained by an alkali saponification method. The degree of saponification of PVA obtained in this way is approximately 80.
~95% is suitable, and the degree of polymerization is 500~95%.
A polymer having a degree of saponification of 5,000 is preferable, and a degree of polymerization of 800 to 3,000 is more preferable.Those having various degrees of saponification and polymerization of 0 or more can be used alone or as a mixture. Furthermore, it goes without saying that the above-mentioned PVA may be modified pvA modified with various modifiers during the production of its raw material or after saponification, such as cation-modified PVA, anion-modified PVA, and the like.

Although any of the compounds mentioned above can be used as the compound to be subjected to the addition and/or condensation reaction with PVA, aldehyde compounds are particularly preferred in the present invention. Examples of aldehyde compounds include formaldehyde, acetaldehyde, propionaldehyde, butyraldehyde, isobutyraldehyde, valeraldehyde,
Aliphatic saturated aldehydes such as isovaleraldehyde: benzaldehyde, o-, m- or p-tolualdehyde,
Aromatic aldehydes such as benzylaldehyde, salicylaldehyde, cinnamaldehyde, α- or β-nataldehyde; Heterocyclic aldehydes such as furfural; Aliphatic unsaturated aldehydes such as acrolein, crotonaldehyde, propiolaldehyde, hexenal, heptenal; Glyxal, Succin dialdehyde, glutardialdehyde, adipodialdehyde, piperine dialdehyde,
Examples include aliphatic unsaturated aldehydes such as speringaldehyde and sebacine dialdehyde.

Particularly preferred as such aldehyde compounds are alkyl aldehyde compounds containing aromatic groups such as benzyl aldehyde.According to the research of the present inventors, PVA modified with aldehydes having such aromatic groups is particularly preferable. 1 Even if the temperature and humidity of the surrounding atmosphere changes,
In particular, sufficient ink receptivity was maintained even under low humidity conditions, and the surface did not become sticky even under high humidity conditions. These effects are due to the fact that aromatic aldehydes are bulkier than aliphatic aldehydes, so even at a relatively low degree of modification and low humidity, the hydrogen bonds of PVA can be sufficiently inhibited. This is thought to be because it is able to maintain good wood-philicity, and also maintains sufficient non-adhesive properties in the case of high humidity.

As mentioned above, P by the compound reactive with the hydroxyl group of PVA
The degree of modification of VA is determined by the degree of saponification of PVA, their molecular weight,
the degree of lignophilicity/hydrophobicity of the PVA and modifier used;
Furthermore, it varies depending on the performance required of the recording material, etc.
The degree of modification is such that the modified PVA does not excessively lose its hydrophilicity, and the degree of modification is 0.05 mol% or more, preferably 3 mol% or more, and less than 0.05 mol%, per PVA molecule. It is not preferable because the performance improvement effect is insufficient compared to unmodified PVA.

By forming the ink-receiving layer of a recording material using the addition and/or condensation reaction product of PVA as described above, a recording material that has excellent ink receptivity and provides a high-quality recorded image can be obtained. It is something that can be done.

As the base material used as the support for the ink-receiving layer in the present invention, any conventionally known base material such as transparent or opaque base material can be used. Examples suitable for the transparent base material include, for example, polyester resin, Diacetate resin, triacetate resin, acrylic resin, polycarbonate resin,
Examples include films or plates of polyvinyl chloride resin, polyimide resin, polysulfone resin, cellophane, celluloid, and glass plates. Preferred opaque substrates include 1, for example, general paper, cloth,
In addition to wood, metal plates, synthetic paper, etc., the above-mentioned transparent substrates may be treated to make them opaque by known means. The thickness of these base materials is not particularly limited, but is generally about 1 to 5,000 mm.

The recording material of the present invention is formed using the above-mentioned main materials, but in the preferred embodiment (1) above, both the base material and the ink receiving layer are translucent, and the recording material as a whole is transparent. This is a photosensitive embodiment. This type of recording material has particularly excellent light transmittance, and is mainly used in OHP applications in which a recorded image is projected onto a screen or the like using an optical device, and is useful as a recording material for transmitted light observation. .

Such a light-transparent recording material is prepared by forming a light-transmitting ink-receiving material from a PVA modified material alone or a mixture of a PVA modified material and another light-transmitting polymer on a light-transmitting substrate as described above. It can be prepared by forming layers.

A method for forming such an ink-receiving layer is to prepare a coating solution by dissolving or dispersing the above modified PVA alone or a mixture of this and other polymers in an appropriate solvent, and then applying the coating solution to the coating solution. 1. For example, it is preferable to apply the transparent substrate onto the Murakami using a known method such as a roll coach ink method, a rod bar coating method, a spray coating method, an air knife coating method, etc., and then dry it immediately. Other methods may be used, such as hot-melt coating the ink alone or a mixture with other polymers, or forming a single sheet for the ink-receiving layer from the above-mentioned materials and then laminating the sheet to the above-mentioned substrate.

In the present invention as described above, the thickness of the ink receiving layer formed on the base material is usually about 1 to 200 gm, preferably about 3 to 07 gm.

Preferred examples of other polymers that can be used in combination with the PVA-modified product in the method described in -F include albumin, gelatin, casein, starch, cationic starch, gum arabic, natural resins such as sodium alginate, polyamides, and polyamides. acrylamide, polyvinylpyrrolidone,
Quaternized polyvinylpyrrolidone, polyethyleneimine, polyvinylpyricillium halide, melamine resin, polyurethane, carboxymethylcellulose, polyvinyl alcohol, polyester, sodium polyacrylate, SB
Synthetic resins include R latex, NBR latex, polyvinyl formal, polymethyl methacrylate, polyvinyl butyral, polyacryminitrile, polyvinyl chloride, polyvinyl acetate, phenolic resin, alkyd resin, etc., and one or more of these materials is desired. used by

When such a translucent polymer is used in combination with the PVA modified product, the weight ratio of the PVA modified product to the other polymer is 20:1-1:20, preferably 15:1-1.
:Use within the range of 10.

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

The recording material of the embodiment (1) formed as described above is a light-transmitting recording material having sufficient light-transmitting properties.

In the present invention, sufficient light transmittance means that the recording material exhibits a linear light transmittance of at least 2%, and preferably a linear light transmittance of 10% or more.

If the linear light transmittance is 2% or more, it is possible to project and observe the recorded image onto a screen using OHP, for example, and in order to clearly observe the details of the recorded image,
It is desirable that the linear light transmittance is 10% 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 a
The spectral transmittance of the straight light that passes through the light-receiving side slit on the extension line of the incident optical path that is more than cts away and is received by the detector is set to 1 using, for example, the 323-type Hitachi self-recording spectrophotometer (manufactured by Hitachi, Ltd.). The Y value of the tristimulus value of the color is determined from the measured spectral transmittance, and is determined by the following equation.

T=Y/Y, Light rate (a planting bulb is placed behind the sample to determine the light transmittance including diffused light), opacity (
The white and black backings are placed on the back of the sample and the ratio is calculated. ), which evaluates translucency using diffused light.

The problem with devices that use optical technology is the behavior of straight-line light, so when evaluating the light transmittance of the recording material to be used in those devices, it is important to check the straight-line transmittance of the recording material. It is particularly important to seek

For example, when observing a projected image on an OHP, in order to obtain a clear and easy-to-see image with high contrast between recorded and non-recorded areas, it is necessary that the non-recorded areas of the projected image be bright, that is, the straight line transparency of the recording material. It is required that the light rate be at a certain level or higher. In OHP tests using test charts, in order to obtain images suitable for the above purpose,
The in-line transmittance of the recording material is required to be 2% or more, and preferably 10% or more in order to obtain a clearer image. Therefore, recording materials suitable for this purpose are:
It is necessary that its in-line transmittance is 2% or more.

The preferred embodiment (2) above is also one of the embodiments (1) above, and is characterized in that the surface of the ink-receiving layer is smooth. This type of recording material has particularly excellent surface gloss, and is particularly useful as a recording material for observing surface images in full color and excellent clarity. The recording material in this embodiment may be transparent or opaque, and either the above-mentioned transparent or opaque base materials can be used. The ink-receiving layer formed on these Omura layers may also be transparent or opaque.The materials and methods used to form the ink-receiving layer are the same as in the embodiment (1) above, but the above-mentioned filler, etc. As long as the surface of the ink-receiving layer can maintain smoothness, it may be used to the extent that the ink-receiving layer becomes opaque.

If necessary, a cast coating method may be used in addition to the above-mentioned coating method, or glossing may be performed using a gloss roll.

The preferred embodiment (3) above is characterized in that the ink-receiving layer of the recording material of the present invention is a porous ink-receiving layer, and the ink-receiving layer of the recording material has particularly high ink-receptivity. It is also useful for observing surface images with excellent water resistance and full-color clarity.

In addition, as an ink-receiving layer that also has the function of a support, there is one in which a sizeless paper is impregnated with a modified PVA material using a size press or the like, or one in which the ink-receiving layer has the function of a support. There are some that have a thicker ink-receiving layer and a peeled base material. The material and method for forming the ink-receiving layer in this embodiment are substantially the same as those in embodiments (1) and (2) above, but in this embodiment, when forming the ink-receiving layer, the ink-receiving layer is It is characterized by the fact that it contains fillers that allow it to quickly accept ink. Preferred examples of such fillers include, for example, organic filler particles such as polystyrene, polyethylene, urea-formalin resin, polyvinyl chloride, and polymethyl methacrylate, in addition to the fillers described in the above-mentioned embodiment (1). and one or more of these are used. It is preferable to use such a filler that improves ink receptivity in the ink receptive layer in a proportion that accounts for about 10 to 90% of the weight of the ink receptive layer.If the amount used is less than this range, the ink receptivity is There is no significant improvement, and if the amount used is greater than that, the physical and mechanical strength of the ink-receiving layer will not be sufficient. When using such fillers in relatively high quantities,
Since sufficient film-forming properties may not always be obtained with the PVA modified product alone, it may be desirable to use a polymer other than the PVA modified product in combination as a binder resin.

In such cases, the PVA modified product is used in the ink-receiving layer in an amount of 1 to 90% by weight, preferably 2 to 50%.

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. In any embodiment, the ink-receiving layer contains a dispersant, a fluorescent dye, a PH
Various known additives such as regulators, defoamers, 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.

According to the recording material of the present invention containing the PVA modified product as described above in the ink-receiving layer, it always shows excellent ink absorbency even when the ambient conditions, such as temperature and humidity, change drastically. Since the ink-receiving layer does not become sticky even under humid conditions, various drawbacks of the prior art are satisfactorily solved.

Therefore, under various conditions, even if ink is repeatedly deposited on the same spot within a short period of time during recording, there will be no ink flow or seepage phenomenon, resulting in high-resolution, clear, water-resistant, and excellent color development. A certain image is obtained. Moreover, it is possible to provide excellent surface gloss that cannot be seen with conventional inkjet recording materials, and it is also possible to observe recorded images by projecting them onto a screen, etc. using optical equipment such as slides and OHPs. It can be applied to applications other than conventional surface image observation, such as a color separation plate for creating a positive plate for color printing, or a CMF used for a color display such as a liquid crystal.

Hereinafter, the present invention will be explained in more detail with reference to Examples, Comparative Examples, and Usage Examples. In addition, parts in the text are based on weight unless otherwise specified.

Example 1 A polyethylene terephthalate film (manufactured by Toshi) with a thickness of 100 μL was used as a translucent base material, and a coating liquid with the following composition was applied onto this film so that the film thickness after drying was 15 μL. Coated using the bar coater method as described above, and heated at 80°C for 10
Dry under conditions for a minute.

A transparent recording material of the present invention was obtained.

Coating liquid composition: water-soluble butyralized PVA (S-LEC W-201,
Manufactured by Block Chemical Co., Ltd., butyralization degree: 7 mol%) 10% aqueous solution Examples 2 to 4 The polyester film used in Example 1 was used as a translucent base material, and a coating liquid with the following composition was applied on this film. The ink-receiving layer was coated by a bar coater method so that the thickness of the ink-receiving layer after drying was 20 gm, and was dried by heat treatment at 80° C. for 20 minutes to obtain a translucent recording material of the present invention.

Coating liquid composition; Acetalized PVA (phenylacetoacetal CW)
-2, manufactured by Block Chemical, degree of acetalization 13 mol%) 10
% aqueous solution support” Coating fluid composition: Acetalized PVA (phenylacetoacetal CW
-5, manufactured by Block Chemical, degree of acetalization 25 mol%) 10
% aqueous solution 51 Coating liquid composition; Acetalized PVA (phenylacetoacetal C
W-5, made by Block Chemical, degree of acetalization 25 mol%) 1
20 parts of 0% MeOH/DMF solution Polyvinylpyrrolide 7 (manufactured by PVP K-90GAF)
10% DMF solution 80 parts Novolac type phenol resin (Regitop PSK-2320, manufactured by Gunei Chemical Co., Ltd.) 10% DNF solution 10 parts Examples 5 to 6 The polyester film used in Example 1 was used as a translucent base material. A coating solution having the following composition was applied onto this film using a bar coater method so that the thickness of the ink-receiving layer after drying was 1 Ogm, and was dried at 80° C. for 10 minutes. Thereafter, it was dried at 140° C. for 10 minutes to obtain a translucent recording material of the present invention.

Coating liquid composition: Acetalized PVA (phenylacetoacetal G
W-2, 2a made by Mizu Kagaku, acetalization degree 13 mol%)
10% aqueous solution 94 parts Water-soluble polyester polyisocyanate (Elastron E-37, No. 1 Kogyo Seiyaku type) 25% aqueous solution 6 parts Crosslinking agent (catalyst) (Elastron Catalyst 32, No. 1 Kogyo Seiyaku type) 0.2 parts Application J Coating liquid composition: Polyvinyl alcohol (PVA-217, manufactured by Kuraray) 1
0% aqueous solution 100 parts Water-soluble epoxy resin (Bunacol EX-145, manufactured by Nagase Chemical Industries)
2 parts Zn (BF4) 2.45% ethanol solution 0.4 parts Example 7 A recording material of the present invention was obtained in the same manner as in Example 2 except that art paper was used as the substrate. The obtained recording material was white and opaque.

The recording materials of Examples 1 to 7 obtained as described above were as follows:
The recording materials according to Examples 3 to 5 are light-transmitting recording materials that have excellent water-based ink fixability and are also excellent in water resistance.

Comparative Example 1 The polyester film used in Example 1 alone was used as a recording material.

Comparative Example 2 Polyvinyl alcohol (P
Example 2 except that VA-217 (manufactured by Kuraray) was used.
A recording material for comparison was obtained in the same manner as described above.

Usage Example: On-demand inkjet recording head (discharge orifice diameter 60JL!1, Inkjet recording was performed using a recording device having a piezo vibrator drive voltage of 70 V and a frequency of 2 KHz.

Bacteria ink (composition) C, R, Direct Yellow 86 2 parts diethylene glycol 20 parts polyethylene glycol #200 10 parts water
70 parts Red ink (composition) C, 1, Acid Red 35 2 parts diethylene glycol 20 parts polyethylene glycol #200 10 parts water
70 parts Blue ink (composition) C, 1, Direct Blue 86 2 parts diethylene glycol 20 parts polyethylene glycol #200 10 parts water
7 parts black ink (composition) CA, food black 2 2 parts diethylene glycol 20 parts polyethylene glycol #
200 10 parts water
70 copies The evaluation results of the above usage example are shown in Part 1 below.
Shown in the table.

Each evaluation item in Table 1 was measured according to the following method.

(1) Ink fixation time is the ink fixation time when you touch the recorded image with your finger when the recording material is left at room temperature or in a low humidity environment of 15°C and 10% RH after recording. The time required for the film to dry and stop adhering to fingers was measured.

(2) The dot density was calculated using Sakura Microdensidometer PD by applying JISK7505 to the printed microdots.
The black dots were measured using M-5 (manufactured by Konishiroku Photo Industry Co., Ltd.).

(3) OHP suitability was measured as a representative example of optical equipment, and the recorded image was projected onto a screen using OHP.
Judging by visual observation, the non-recorded area is bright, the OD (optical density) of the recorded image is high, and a clear and easy-to-see projection image with high contrast is obtained. O1 The non-recorded area is slightly dark and the recorded image If the oD is rather low and the line with a pitch width of 0.5i+m and a thickness of 0.25mm cannot be clearly distinguished, Δ, the non-recorded area is quite dark, the OD of the recorded image is quite low, and the pitch width [■, thickness 0.3
A sample in which the mm line could not be clearly distinguished or a non-recorded area and a recorded image could not be distinguished was rated as "×".

(4) Linear transmittance was measured using a 323-type Hitachi self-recording spectrophotometer (manufactured by Hitachi, Ltd.), keeping the distance from the sample to the light-receiving side at approximately 9 cm, and measuring the spectral transmittance as described above ( 1) It was calculated using the formula.

(5) Gloss was measured by measuring the 45° specular gloss of the surface of the recording material based on JIS Z8741.

(6) For water resistance, when the recording material was immersed in still water for 1 minute, it was rated 0 if there was no loss or peeling of the coating layer due to dissolution on the surface, and rated if it was not.

(Leaving space below) 1 minute 1 minute 1 minute within 1 minute 1 minute low humidity 10 minutes 5 minutes 7 minutes 3 minutes 5 minutes LJL
1.0 1.0 1. Ot,
o+,.

0) IP' OOOOO education pa 80%
77% 74% 78% 80% own 110.
Yu Oo O "L Cliff JL l Kasa" L Month 7 1 Eni Otku Jau 1 Fang "L Room temperature 2 minutes 1 minute 1 day or more 3 minutes Low humidity 10 minutes 5 minutes
Mark or above 20 minutes - Upper 1st - Upper 2nd 2nd level 1
．． 0 1.1 1.2 1.0
− ×

Claims (3)

[Claims] (1) A recording material comprising a base material and an ink-receiving layer provided on the base material, wherein the ink-receiving layer contains an addition and/or condensation reaction product of polyvinyl alcohol. Recorded material. (2) The recording material according to claim (1), wherein the condensation reaction product of polyvinyl alcohol is a condensation reaction product of polyvinyl alcohol and an aldehyde. (3) The recording material according to claim (1), wherein the aldehyde is an aromatic group-containing aldehyde.