JPS61199979A - Ink jet recording system - Google Patents

Abstract

PURPOSE:To prevent the occurrence of such troubles as curling of recording mediums, adherence of finter prints, etc., regardless of changes of ambient conditions by using a specific recording medium and a specific aqueous ink. CONSTITUTION:An ink-accepting layer is composed of reaction products of a polyhydric alcohol, boric acid, and/or a borate. The water content of an aqueous ink is controlled to 20-90wt%. The recording medium of such a composition is free of curling even when ambient conditions, particularly humidity is changed. Also, the ink-accepting layer keeps excellent ink acceptancy for specific aqueous inks under highly humid conditions and its surface is free of becoming tacky. The aqueous ink used contains a water-soluble organic solvent, particularly polyhydric alcohol solvents and 20-90wt%, preferably 30-70wt% water. Even under the condition, excellent ink acceptancy can be attained.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an inkjet recording method using aqueous inks, and more particularly to an inkjet recording method that uses aqueous inks, and more particularly, to Smooth recording is possible even under conditions,
The present invention also relates to an inkjet recording method that provides a high-quality recorded image that does not cause color transfer of the recorded image, blocking between recording materials, or contamination due to fingerprints, etc. even under high humidity conditions after recording.

(Prior Art) Inkjet recording methods include various ink (recording liquid) 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 heats the ink to foam it. This method utilizes the pressure to generate and fly ink droplets, and some or all of them adhere to a recording material such as paper to perform recording, but it generates less noise. It is attracting attention as a recording method that allows high-speed printing and multicolor printing.

Ink for inkjet recording is mainly composed of a water-soluble dye as a recording agent and a liquid medium.

Water-soluble dyes, preferably acidic dyes or direct dyes, are used as recording agents in terms of safety, light resistance, recording properties, etc., while water is mainly used as liquid media in terms of safety and recording properties. The main component is used, and polyhydric alcohols and the like are often added to prevent nozzle clogging and improve ejection stability.

Furthermore, as the recording material used in the inkjet recording method, conventionally used is a recording material consisting of a porous ink-receiving layer provided on a base material called ordinary paper or inkjet recording paper. . However, as the performance of inkjet recording apparatuses improves and becomes more widespread, such as faster recording speeds and multi-color recording, more sophisticated and wide-ranging properties are being required of recording materials.

That is, it is necessary that the ink be absorbed as quickly as possible and that the ink bleed be appropriate. Furthermore, in order to carry out color inkjet recording using color inks, a recording material that is particularly excellent in color development and sharpness of the dye used as the recording agent and provides high chromaticity is required.

Furthermore, recorded images recorded by inkjet recording are required to be excellent in per-image storage stability and durability, particularly in water resistance and light resistance.

(The problem that the invention is trying to solve) However,
The reality is that a recording method that satisfies all of these required performances and provides a recorded image is not yet known.

Most of the recording materials used in conventional inkjet recording methods generally have an ink-receiving layer made of a water-soluble polymer on the surface of a base material such as paper or plastic film. In order to meet the demands of the prior art, various other efforts have been made.

However, since these ink-receiving layers are made of water-soluble polymers, they are sensitive to the ambient conditions during use, especially temperature and humidity, and changes in the humidity of the ambient atmosphere may cause the recording material to curl, causing printer problems. It becomes difficult to record images smoothly within the recording medium, and images recorded under such conditions are unsatisfactory due to distortion. especially,
When observing these recorded images with transmitted light using an OHP (overhead projector) or the like, problems arise such as the image formed by the transmitted light being out of focus.

Furthermore, under high humidity conditions, the surface of the ink-receiving layer becomes sticky during recording, and when attached to a printer, it adheres to the printer's feed roller, etc., making the recording material uneven or impossible to convey, making it difficult to move smoothly. A problem arises in that recording is not possible. Further, after recording, problems such as color transfer of the ink forming the recorded image and blocking of recording materials with each other occur. Furthermore, when handling recording materials before and after recording, if you touch them with your palms or fingers,
Another disadvantage is that the recording surface is easily contaminated by fingerprints and the like.

This problem under high humidity conditions can be solved by forming the ink-receiving layer from a hydrophobic polymer, but an ink-receiving layer made of such a hydrophobic polymer has poor receptivity to water-based ink. , it takes a long time to dry the attached ink, and the practicality of the inkjet recording method itself is lost.

Therefore, an object of the present invention is to avoid problems such as curling of the recording material and adhesion of fingerprints despite changes in the ambient conditions during recording, and to maintain excellent ink receptivity even under high humidity conditions. To provide an inkjet recording method that does not cause any trouble in a printer while printing, and that provides a recorded image with excellent water resistance, temperature resistance, and storage stability after recording.

As a result of intensive research in order to solve the drawbacks of the prior art as described above, the present inventor has found that, in an inkjet recording method, by using a recording material with a specific configuration and an aqueous ink with a specific configuration, The present invention was completed based on the finding that an inkjet recording method can be provided that solves various problems.

(Disclosure of the Invention) That is, the present invention provides an inkjet recording method in which recording is performed by attaching small droplets of aqueous ink to a recording material having an ink-receiving layer provided on a base material. is an inkjet recording method characterized in that the aqueous ink is made of a reaction product of a polyhydric alcohol and boric acid and/or a boric acid salt, and the water content of the aqueous ink is 20 to 90% by weight.

To explain the present invention in more detail, the first feature of the present invention is that the ink-receiving layer of the recording material is composed of polyhydric alcohol, boric acid and/or borate, and is used as a recording material in an inkjet recording method. The second characteristic is that the ink used for recording on such recording materials has a moisture content of 20 to 90% by weight.
The point is that water-based ink is used.

That is, according to detailed research by the present inventors, by forming the ink-receiving layer from a reaction product of polyhydric alcohol and boric acid and/or borate, the recording material obtained can The recording material does not curl even when the humidity changes, and the ink-receiving layer maintains excellent ink receptivity for aqueous ink with a specific composition even under high humidity conditions. As a result, the above-mentioned problems of the prior art are solved.

The reaction product of a polyhydric alcohol and boric acid and/or borate used in the present invention and which primarily characterizes the present invention is a reaction product of a polyhydric alcohol, preferably a polymeric polyhydric alcohol, and boric acid and/or a boric acid salt. Alternatively, it is a product produced by reacting with a borate as exemplified below.

(The above formula is merely an example for explaining the present invention and does not limit the scope of the present invention in any way.) Conventionally, polyhydric alcohols and boric acid and/or boric acid salts have reacted as described above. It is well known that the reaction between polyhydric alcohols and boric acid and/or borates can be used to produce coated papers. (Unexamined Japanese Patent Publication No. 1983-
(See Publication No. 211699).

The present inventor has conducted various studies on the reaction products of polyhydric alcohols such as L and boric acid and/or boric acid salts, and has found that the above reaction products are compared to the raw material polyhydric alcohols. , its water solubility is significantly reduced,
Unexpectedly, water-based inks, especially inkjet recording inks whose liquid medium is a mixture of water containing a specific amount of water and a water-soluble organic solvent, have an excellent affinity that is almost as good as that of water-soluble polymers. When the ink adheres to the ink-receiving layer made of these reaction products, the ink is quickly absorbed and retained. Unexpectedly, even under high humidity conditions, the surface of the ink-receiving layer does not become sticky, sticky, or stains such as fingerprints, and as a result, the ink-receiving layer made of the reaction product The recording material is used in the inkjet recording method.

Moreover, by recording with water-based ink as described above,
It has been found that the drawbacks of the various prior art techniques mentioned above are overcome.

The polyhydric alcohol used to form the ink-receiving layer in the present invention has a medium to high molecular weight, and is preferably a polymeric polyhydric alcohol that has a film-forming ability by itself. It is sufficient that the reaction product with boric acid and/or borate has film-forming ability.

Such polyhydric alcohols include polyvinyl alcohol, partial hydrolysates of polyvinyl acetate, complete or partial hydrolysates of copolymers of vinyl acetate and other vinyl monomers, (meth)acrylic acid, maleic acid, itaconic acid. Homopolymers of monoesters of unsaturated carboxylic acids such as ethylene glycol and polyhydric alcohols or copolymers with other vinyl monomers, methylolated products of homopolymers of (meth)acrylamide or copolymers with other vinyl monomers, etc. Polyether polyols such as polyethylene glycol and polypropylene glycol, polyols having ester bonds, hydroxyethyl cellulose, or modified products thereof, etc., may be mentioned.

Particularly preferred in the present invention are polymeric polyhydric alcohols in which their hydroxyl salts are bonded to polymer chains.

Depending on the molecular weight, these polyhydric alcohols range from liquid or wax-like alcohols with no film-forming ability to those with strong film-forming ability, and any of them can be used in the present invention. Preferable ones have a molecular weight of 500 or more, especially 1
,000 or more, and an ink receiving layer with excellent strength can be formed.

In the present invention, the boric acid and/or borate to be reacted with the polyhydric alcohol as described above include boric acid, alkali metal salts of boric acid such as sodium salts and potassium salts,
These are alkaline earth metal salts such as ammonium salts, magnesium salts, and calcium salts, and these borates are generally 0.01 parts by weight per 100 parts by weight of the above polyhydric alcohol.
These are used in a proportion of ~50 parts by weight, and the amounts used are:
It is used with appropriate changes depending on the type and molecular weight of the polyhydric alcohol used.

The criteria for determining the amount to be used are the water properties of the resulting reaction product and the affinity for water-based inks.

Generally, when using a polyhydric alcohol with a relatively low molecular weight, boric acid and/or a boric acid salt acts as a crosslinking agent and the reaction product forms a film, as shown in the formula (rl) above. It is used in a relatively large amount so as to produce the desired performance, while when a high molecular weight one is used, it may be sufficient to add boric acid and/or a boric acid salt as shown in the formula (1) above.

The amount of such boric acid and/or borate used is
Those skilled in the art can easily determine this by repeating experiments while monitoring the water solubility and ink receptivity of the resulting reaction product.

The ink-receiving layer of the recording material used in the present invention is formed from a reaction product of a polyhydric alcohol as described above and boric acid and/or a boric acid salt. It may be manufactured before forming the layer; in this case, it is preferable to prevent the reaction product from gelling excessively; excessive gelling makes it difficult to form an ink-receiving layer on the substrate. become. A preferred method is to form an ink-receiving layer by mixing an aqueous solution of a polyhydric alcohol and an aqueous solution of boric acid and/or a boric acid salt, and then react the two at the same time as drying. A method may also be used in which either one of these solutions is applied to the substrate, and then the other solution is applied or impregnated.

The ink-receiving layer of the recording material used in the present invention is formed using the reaction product of the polyhydric alcohol and boric acid and/or borate as described above.
In addition to the reaction products described above, other water-soluble polymers, for example, may be used in combination with the above-mentioned polymeric materials as long as they do not interfere with the purpose of the present invention.

Preferred examples of such other water-soluble polymers include:
Albumin, gelatin, casein, starch, cationic starch, gum arabic, natural resins such as sodium alkinate, polyamide, polyacrylamide, polyvinylpyrrolidone, quaternized polyvinylpyrrolidone, polyethyleneimine, polyvinylbilicylium halide, melamine resin , polyurethane, polyester, polyacrylic soda, and other synthetic resins, and one of these materials may be used in combination as desired.

Furthermore, in order to reinforce the strength of the ink-receiving layer and/or improve the adhesion with the base material, SBR latex, NBR latex, polyvinyl formal, polymethyl methacrylate, polyvinyl butyral, polyacrylonitrile, polyvinyl chloride may be added as necessary. Hydrophobic resins such as , polyvinyl acetate, phenol resins, and alkyd resins may be used in combination.

In addition, in order to improve the ink absorbency of the ink-receiving layer, various fillers such as silica, clay, etc. are added to the ink-receiving layer.
Fillers such as talc, diatomaceous earth, calcium carbonate, calcium sulfate, barium sulfate, aluminum silicate, synthetic zeolites, alumina, zinc oxide, lithopone, satin white, and the like can also be dispersed in the ink-receiving layer.

In the present invention, any conventionally known substrates, such as transparent or opaque, can be used as the support for the ink-receiving layer made of the reaction product as described above. Examples include films or plates of polyester resins, diacetate resins, triacetate resins, acrylic resins, polycarbonate resins, polyvinyl chloride resins, polyimide resins, cellophane, celluloid, and glass plates. If such a transparent base material is used and the ink-receiving layer is also formed to be transparent, it becomes a translucent recording material used for observing a projected image by OHP or the like.

In addition, examples of preferred opaque substrates include general paper, cloth, wood, metal plate 1 synthetic paper, etc., as well as the above-mentioned transparent substrates treated to make them opaque by known means. It will be done. If you use such an opaque base material, 1
It becomes the recording material used to observe the surface image.

As a method for forming an ink receiving layer on at least one surface of such a base material, a reaction product of a polyhydric alcohol and boric acid and/or a boric acid salt as described above is used alone or in a mixture in a suitable solvent. A coating solution is prepared by dissolving or dispersing the coating solution, and the coating solution is coated on the substrate by a known method such as a roll coach ink method, a rod bar coating method, an air knife coating method, a spray coating method, etc. and then quickly drying, preferably using a mixed solution of polyhydric alcohol and boric acid and/or boric acid salt, or a solution thereof separately, and applying it as above and reacting it on the substrate. This is a drying method. Alternatively, a single ink-receiving layer may be formed from the above-mentioned materials by a known method such as a heat stretching method or a T-die method, and the ink-receiving layer may also be used as a support. Alternatively, the ink-receiving layer may be formed on the base material by laminating the sheet onto the base material, hot-melt coating the polymer material, or the like.

The thickness of the ink-receiving layer thus formed is not particularly limited as long as it can receive ink, and although it depends on the amount of ink to be recorded, it is not particularly limited as long as it is 0.14 m or more. Practically speaking, a range of 0.5 to 30 pm is suitable.

In the method of the present invention, the components of the water-based ink applied to the above-mentioned specific recording material by the inkjet recording method may be any of known components. , reactive dye,
It is a water-soluble dye represented by food coloring, etc., and is particularly suitable as an ink for inkjet recording methods, and in combination with the recording material mentioned above, it can be used to achieve color development, clarity, stability, light resistance, and other required properties. For example, C,1, direct blur/17.
19.32.51.71, 108.146; C, 1, Direct Blue 6.22, 25.71, 86.90.1
06.199;C.

■, Direct Ray, Do l, 4, 17.28.83, C
, 1, Direct Niro 12.24.26.86.98
．． 142. C, 1, Direct Orange 34.39.4
4.46.60; C, 1, Direct Violet 47
．． 48; C, 1, Direct Brown 109; C, 1,
Direct dyes such as Direct Green 59, C, 1, Acid Black 2, 7.24.26.31, 52.63.1
12.118; C, 1, acid blue 9.22.40
．． 59.93.102.104.113.117.12
0,167.229.234°C, 1, Acid Red 1, 6.32.37.51.52.80, 85.87.
92.94.115.180.256.317.315
．． C.

■, Ashino Draw 11.17.23.25°29.4
2.61,71. C, 1, acid orange 7.19;
(,1, Acidic dyes such as Acid Violet 49 are preferred; others, C,1, Basic Blur 7li2: (
, 1, Basic Blue 1.3, 5, 7.9.24.2
5.26.28.29, C, 1, Basic Boo, Do l
, 2,9°12.13.14,37. C, 1, Basic Violet 7.14.27. C, 1, Food Black L, 2, etc. can also be used.

The above examples of dyes are particularly preferable for inks applicable to the recording method of the present invention, but dyes for inks used in the present invention are not limited to these dyes.

Such water-soluble dyes are generally used in a proportion of about 0.1 to 20% by weight in conventional inks, and this range may also be used in the present invention.

The solvent used in the ink used in the present invention is a mixed solvent of water and a water-soluble organic solvent, and particularly preferred is a polyhydric alcohol-based organic solvent that has an effect of preventing ink from drying out as a water-soluble organic solvent. It contains.

Further, as water, it is preferable to use deionized water rather than ordinary water containing various ions.

Examples of water-soluble organic solvents used in combination with water include methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, 5ec-butyl alcohol, tert-butyl alcohol, and isobutyl alcohol. Carbon number 1~
4 Alkyl alcohols; Amides such as dimethylformamide and dimethylacetamide; Ketones or keto alcohols such as acetone and diacetone alcohol; Ethers such as tetrahydrofuran and dioxane; Polyalkylene glycols such as polyethylene glycol and polypropylene glycol: ethylene glycol , propylene glycol, butylene gelcol, triethylene glycol, 1,2,6-hexandriol, thiodiglycol, hexylene glycol, diethylene glycol, and other alkylene glycols in which the fullkylene group contains 2 to 6 carbon atoms; glycerin Lower alkyl ethers of polyhydric alcohols such as ethylene glycol methyl (or ethyl) ether, diethylene glycol methyl (or ethyl) ether, triethylene glycol monomethyl (or ethyl) ether; N-methyl-2-pyrrolidone, 1,3- Examples include dimethyl-2-imidazolidinone.

Among these many water-soluble organic solvents, polyhydric alcohol-based organic solvents such as diethylene glycol and lower alkyl ethers of polyhydric alcohol-based organic solvents such as triethylene glycol monomethyl (or ethyl) ether are preferred.

The ink used in the method of the present invention has the above-mentioned components as essential components. However, in the method of the present invention, an aqueous ink with a specific water content is used for the specific recording material as described above. By this, excellent ink receptivity is achieved.

This is because the ink-receiving layer of the recording material used is formed from the reaction product of polyhydric alcohol and boric acid and/or borate as described above. When an ink consisting of the above is used, the ink-receiving layer of the recording material is dissolved or swollen by the organic solvent in the ink, and the ink is quickly absorbed and retained.

Therefore, the water-based ink used in the inkjet recording method of the present invention has a medium containing a water-soluble organic solvent, particularly a polyhydric alcohol-based organic solvent, and a wood content of 20 to 90% by weight. %, particularly preferably 30-7
The best ink receptivity is achieved when the amount is 0% by weight.

That is, when the water content in the ink exceeds 90% by weight, even if the above-mentioned recording material is used, the affinity of the ink to the ink-receiving layer is insufficient, and the ink receptivity decreases. This is not suitable because it increases the time required to fix the ink, limits the recording speed, and causes mixing of inks of different colors when inks overlap, and unnecessary enlargement and disorder of ink dots. In addition, such inks have problems in terms of ejection stability and dissolution stability of the recording agent, and are not suitable. Furthermore, if the water content in the ink is less than 20% by weight, even if the above-mentioned recording material is used, the surface of the ink-receiving layer will be difficult to dissolve or swell with the ink, and the ink-receptivity will decrease. It is not appropriate to do so.

In addition to the above-mentioned components, the ink used in the present invention may contain various additives such as a surfactant, a viscosity modifier, and a surface tension modifier, if necessary.

In the method of the present invention, the inkjet recording method for performing recording by applying the above-mentioned ink to the above-mentioned specific recording material is such that the ink is effectively separated from the nozzle and the ink is applied to the recording material, which is a projecting object. Any method may be used as long as it can be transferred, and typical examples of these methods include ■EEE Transactions on
Industry ApplicationsV
ol, JA-13, No. 1 (February/March 1977 issue), Nikkei Electronics. The methods described above are suitable for the method of the present invention.To explain some of them, there is an electrostatic attraction method.In this method, a nozzle and an accelerating electrode placed in front of the nozzle are used. There is a method in which a strong electric field is applied between the ink particles and the ink particles are drawn out one after another from a nozzle, and while the drawn ink flies between the deflection electrodes, an information signal is applied to the deflection electrodes to record the information, and the ink particles are deflected. In addition, there is a method in which ink particles are ejected in response to an information signal, and both methods are effective for the method of the present invention.

The second method is to forcibly eject minute ink particles by applying high pressure to the ink with a small pump and mechanically vibrating the nozzle with a crystal oscillator. At the same time as the injection, it is charged according to the information signal. When the charged ink particles pass between the deflection electrode plates, they are deflected according to the amount of charge. Another method using this method is called the microdot inkjet method. In this method, ink pressure and excitation conditions are kept within a certain range of appropriate values, and two types of ink droplets, large and small, are ejected from the nozzle tip. Only small and medium-sized droplets are generated and used for recording. The feature of this method is that it is possible to obtain a group of minute droplets even with a conventionally large nozzle diameter.

A third method is a piezo element method, in which a piezo element is used as a pressure means for applying pressure to the ink, rather than a mechanical means such as a pump as in other methods. This method applies an electric signal to a piezo element to cause mechanical displacement, thereby applying pressure to the ink and ejecting it from a nozzle.

In addition, an inkjet jet in which the ink subjected to the action of thermal energy undergoes a sudden change in its body end, and the acting force due to this change in state causes the ink to be ejected from a nozzle, is disclosed in Japanese Patent Application Laid-Open No. 54-51837. method can also be used effectively.

According to the method of the present invention as described above, since a water-based ink is used as the ink in the conventional inkjet recording method, the ink receiving layer of the recording material used must be formed from a water-soluble polymer. Therefore, due to changes in ambient conditions, especially humidity, the recording material may curl or have fingerprints attached, resulting in various problems as mentioned above.However, in the method of the present invention, even changes in ambient conditions during recording can cause Since a recording material that does not cause curling or fingerprints is used, problems caused by curling and stains caused by fingerprints, etc., are sufficiently solved.

In addition, in the method of the present invention, since the ink receiving layer of the recording material used is formed from the reaction product of the polyhydric alcohol and boric acid and/or borate as described above, it can be used under normal ambient conditions. Of course, it maintains excellent ink receptivity even under high humidity conditions and prevents the surface from becoming sticky, which solves the various problems mentioned above caused by stickiness and allows for smooth printing. Inkjet recording methods can be implemented. Furthermore, according to the method of the present invention, as described above, a smooth inkjet recording method can be carried out, and even after recording, there is no smudge or smudge of the applied ink, and there is no need to overlap the recorded images. Also, problems such as blocking between recording materials are solved, and therefore images with excellent storage stability can be provided.

The above remarkable effects are achieved because the ink-receiving layer of the recording material used in the present invention is formed from a reaction product of polyhydric alcohol and boric acid and/or borate. The ink-receiving layer exhibits excellent affinity for the aqueous medium of the aqueous ink containing a water-soluble organic solvent, preferably a polyhydric alcohol-based organic solvent, and exhibits excellent compatibility under normal ambient conditions as well as under high humidity conditions. This is believed to be because the ink-receiving layer exhibits excellent liquid absorbency only in the areas to which the water-based ink described above is applied while maintaining excellent surface tack-free properties.

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

Example 1 (Preparation of recording material) A polyethylene terephthalate film (manufactured by Toshi) with a thickness of 100 gta was used as a transparent base material.

The following coating liquid was applied onto this film until the film thickness after drying was 8.
Apply by percoater method so that the thickness is 80℃.
The film was dried for 10 minutes to obtain a translucent recording material used in the present invention.

Coating liquid composition Polyvinyl alcohol (PVA-217, manufactured by Kuraray) 10 parts Boric acid 0.2 part Sodium hydroxide
0.07 part water
90 parts The thus obtained recording material of the present invention was colorless and transparent.

Examples 2 to 4 and Comparative Examples 1 to 2 (Preparation of recording material) The same polyethylene terephthalate film as used in Example 1 was used as the base material, and as the ink receiving layer,
Each of the following compositions was coated using a bar coater method so that the dry film thickness of the ink-receiving layer was 8 partsm, and each of these was dried at 80°C for 10 minutes. Comparative recording materials (Examples 2 to 4) and recording materials used for comparison (Comparative Examples 1 to 2) were obtained.

"Shiba Ai" Polyvinyl alcohol (PVA-217, manufactured by Kuraray) 10 parts Borax 0.01 part Water
9
0 part Fruit "Rainbow" L dan Cation-modified polyvinyl alcohol (PVA-C-318AA, manufactured by Kuraray) 1 O part Borax
0.2 parts water
90 parts real”
1 1j Hydroxyethyl cellulose (HECAH-15, manufactured by Fuji Chemical) 5 parts Mannitol 1.5 parts Borax
0.3 parts water
93 parts ratio "Komaro [Upolyvinyl alcohol (PVA-217, manufactured by Kuraray) 10 parts water

90 parts polyvinyl alcohol (PVA-220, manufactured by Kuraray) 5 parts polyvinylpyrrolidone (PVP K2O, manufactured by GAF) 5 parts water

9 Part O Examples 5 to 6 (Preparation of recording material) A polyethylene terephthalate film (bundled V) with a thickness of 100 g+a was used as a transparent base material.The following coating liquid was applied on this film. , coated with a bar coater method so that the film thickness after drying was 8 JLm, and coated at 80°C for 10
The resulting recording material was immersed in a 1% borax aqueous solution for 3 seconds and then dried at 80°C for 10 minutes. 5-6)
I got it.

"Shigosai" Cation modified polyvinyl alcohol (PVA-C-318AA, manufactured by Kuraray) 10 parts water

90 parts 1 part polyvinyl alcohol (PVA-220, manufactured by Kuraray) 5 parts polyvinylpyrrolidone (manufactured by PVP K-90GAF) 5 parts water

90 parts Examples 7 to 12 and Comparative Examples 3 to 4 The following four types of inks were used for each of the recording materials prepared in Examples 1 to 6 and Comparative Examples 1 to 2 above.
On-demand inkjet recording head that ejects ink using a piezo vibrator (ejection orifice diameter: 607 mm)
zm, piezo vibrator drive voltage 70V, frequency 2KHz)
Inkjet recording was carried out using a recording device having the following.

On top! (Set S:,) C, 1, Direct Yellow 86 2 parts diethylene glycol 20 parts polyethylene glycol #2
00 10 parts water
70 parts El (composition) C, 1, Acid Red 35 2 parts diethylene glycol 20 parts polyethylene glycol #
200 10 parts water
70 parts 1 EL (composition) C, X, Direct Blue 86 2 parts diethylene glycol 20 parts polyethylene glycol #2
00 10ffl water
7 o parts Flat ink (composition) C, 1, Food black 2 2 parts diethylene glycol 20 parts polyethylene glycol #
200 10 parts water
70 parts Examples 1-6 and Comparative Examples 1-2
Table 1 shows the evaluation results of the inkjet recording method using the recording material. Each evaluation item in Table 1 was measured according to the following method.

(1) Ink fixation time is the time required for the ink to dry and stop adhering to your finger when you leave the recording material at room temperature (20°C, 65% RH) after recording and touch the recorded image with your finger. 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,
A projection image that is clear and easy to see with high contrast is obtained. O1 The non-recorded area is slightly dark, the OD of the recorded image is slightly low, and the line with a pitch width of 0.5 mm and a thickness of 0.25 mm cannot be clearly distinguished. , the non-recorded area is quite dark, the OD of the recorded image is quite low, the pitch width is 1 mm, and the thickness is 0.
3. Cases in which the line 1 could not be clearly distinguished or in which the non-recorded area and the recorded image could not be distinguished were marked as x.

(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 in (1) above. ) was calculated using the formula.

(5) Regarding transportability, when the recording material was loaded into the printer under conditions of 35°C and 85% RH, the printer's feed roller could not transport it due to the stickiness of the surface of the ink receiving layer.
Those that could not be recorded were marked as ×, and those that were not recorded were marked as O.

(6) #Fingerprint property was determined visually after wiping off the fingerprint-attached area on the film surface with a cloth. Fingerprints were measured at 20 points, and those for which fingerprint marks were visually confirmed at 12 points or more even after wiping were rated "×", and those less than 12 points were rated "O".

As is clear from Table 1, in the method of the present invention, a recording material having an ink-receiving layer made of a reaction product of a polyhydric alcohol and boric acid and/or a borate is used,
In addition, by using a water-based ink whose medium is a specific amount of water and a wood-philic organic solvent, especially a polyhydric alcohol,
While maintaining excellent ink receptivity, excellent inkjet recording was possible without any trouble within the printer even under high humidity conditions.

On the other hand, in Comparative Examples 3 and 4 in which a recording material having a water-soluble ink-receiving layer was used, the recording material could not be fed smoothly within the printer, and satisfactory inkjet recording could not be performed. .

Example 13 On the recording material prepared in Example 1, an on-demand inkjet recording head (discharge orifice diameter 60 JLm, piezo vibration Inkjet recording was performed using a recording device having a slave drive voltage of 70 V and a frequency of 2 KHz.

Ink failure, A water
98 parts c, r, direct blue 86 2
Part Intayo, B Glycerin 8 parts Water
90 part G, 1
．． Direct Blue 88 2nd part ink defect, C
Glycerin 28 parts water
70 copies C0■
, Direct Blue 86 2 parts ink, D ethylene glycol 48 parts water
50 copies c
, r, Direct Blue 86 2nd part ink floor,
E glycerin 10 parts N-methyl-2
-Pyrrolidone 40 parts Polyethylene glycol #2
00 38 parts water
l O part C,1, Direct Blue 88 2 parts Table 2 shows the results of the evaluation of the recording characteristics performed above. Ink A of the five types of ink above
The solubility of the recording agent was unstable, causing clogging in the nozzle, and stable recording could not be performed. Each evaluation item in Table 2 was measured according to the following method.

(1) Ink fixing time was measured in the same manner as in Table 1.

(2) Dot density was measured for blue dots in the same manner as in Table 1.

(3) Color clarity was determined by visually comparing the color clarity of the inkjet recorded images, and ranking the best as O1 and the worst as ×, and ranked as @, O1Δ, and ×.

As is clear from Table 2, in the method of the present invention, for a recording material having an ink receiving layer made of a reaction product of a polyhydric alcohol and boric acid and/or a borate,
Water-based ink (ink No. B) whose medium is a specific amount of water and a water-soluble organic solvent, especially a polyhydric alcohol-based organic solvent
-D), good inkjet recording was achieved. On the other hand, when the water content exceeds 90% and when the water content is less than 20% (ink N
o, A and E) were not satisfactorily recorded.

(Margin below)

Claims (3)

[Claims] (1) A recording material having an ink-receiving layer provided on a base material,
In an inkjet recording method in which recording is performed by depositing droplets of aqueous ink, the ink-receiving layer is made of a reaction product of a polyhydric alcohol and boric acid and/or a borate salt, and moisture is 2
An inkjet recording method characterized in that the amount is 0 to 90% by weight. (2) The inkjet recording method according to claim (1), wherein the aqueous ink medium comprises water and a water-soluble organic solvent. (3) The inkjet recording method according to claim (1), wherein the water-soluble organic solvent is a polyhydric alcohol-based organic solvent.