JPS60222281A - Ink jet recording medium - Google Patents

Abstract

PURPOSE:To enable to appropriately control ink-absorbing speed, ink-absorbing capacity and degree of blurring of dots, by using synthetic amorphous silica which contains fluorine. CONSTITUTION:In an ink jet recording paper, an ink-receiving layer comprising synthetic amorphous silica and an aqueous adhesive is provided on a base. In said recording paper, synthetic amorphous silica contains fluorine. Namely, the recording medium comprises at least one ink-receiving layer, which comprises fluorine-containing synthetic amorphous silica as a pore-constituting material. Accordingly, it is possible to appropriately control the ink-absorbing speed, the ink-absorbing capacity and the degree of blurring of dots.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a recording medium recorded using ink, and the present invention relates to a recording medium that uses ink to record, and in particular, images and characters recorded on the medium have a high degree of hardness, a clear color tone, and a high ink absorption capacity. This article relates to inkjet recording media that are excellent, especially suitable for multicolor recording.The inkjet recording method uses various operating principles to fly minute droplets of ink and make them adhere to a recording medium such as paper, creating an image. , Is there something that records characters, etc., or is it fast?
Features include low noise, easy multicolor printing, great flexibility in recording patterns, and no need for development or fixing. In addition, images formed by the multicolor inkjet method can produce records that are comparable to those produced by the plate-making method or color photographic methods. For applications that require a small number of copies, it is widely applied to the field of full-color image recording because it is cheaper than photographic technology.The recording medium used in this inkjet recording method is ordinary printing. Efforts have been made in terms of equipment and ink composition to use the high-quality paper and coated paper used for writing and writing.

However, as the performance of inkjet recording devices has improved and their applications have expanded, such as higher speeds, higher definition, and full color, more advanced characteristics have become required of recording media. That is, as the recording medium,
The density of the ink dots must be high, the color tones must be bright and colorful, the ink must be absorbed quickly so that the ink does not run out or smear even if the ink dots overlap, and the ink dots must spread horizontally. In addition, the resistance of the dye should not be reduced, preferably enhanced, when the recorded image is exposed to ultraviolet rays, oxygen in the air, or water. @ Several proposals have been made in the past to solve these problems. Japanese Patent Application Laid-open No. 52-53012 describes an inkjet recording paper made of low-pull base paper moistened with surface treatment paint, and Japanese Patent Application Laid-Open No. 53-4
No. 9113 discloses an inkjet recording paper in which a sheet containing urea-formalin resin powder is impregnated with a water-soluble polymer.0 These general paper type inkjet recording papers absorb ink quickly. Yes, but
In addition, JP-A-55-5830 discloses an inkjet recording paper in which an ink-absorbing coating layer is provided on the surface of the support. , JP-A No. 55-51583 shows an example of using non-colloidal silica powder as a pigment in the coating layer.
Further, JP-A-55-11829 discloses an example of smeared paper using a two-layer structure with different ink absorption speeds.0 These coated paper type inkjet recording papers are:
In terms of dot diameter, dot shape, dot density, and color tone reproducibility, it is improved over -pattern paper type inkjet paper, but in terms of absorption capacity, it is not as good as regular paper type, and coated type inkjet paper is improved. Therefore, the present inventors proposed a coat type structure with a fast absorption rate and a large absorption capacity in JP-A-58-110287. In other words, the present inventors succeeded in improving the dot diameter and adjusting the bleeding rate), and achieved the present invention.That is, the present inventors jetted an inkjet ink onto a recording medium to produce a recorded image. In the inkjet recording method, the recording medium has at least one ink-receiving layer, and the ink-receiving layer contains fluorine-containing synthetic amorphous silica as a pore forming material, thereby improving the ink absorption speed and ink absorption. The present invention was achieved by discovering that the capacity and degree of bleeding of dots can be suitably adjusted. I'm not sure if it's possible, but I can think of the sum of 2 and 0 as shown below.

Synthetic amorphous silica usually has a surface area of 80% by BIT method.
It has an extremely large size of ~800 m'/#, and has a structure in which surface hydrated hydroxyl groups are coordinated, and has a large ability to adsorb water molecules, making it an extremely hydrophilic pigment. When these are used in the ink-receiving layer, the ink-absorbing capacity increases, but at the same time, they also have a large affinity with the ink vehicle, so absorption and penetration compete with each other, and the absorption capacity depends on the surface area of the pigment used and the thickness of the ink-receiving layer. However, by treating the pigment used with fluorine as in the present invention, it is possible to finely adjust the affinity with the ink vehicle without changing the absorption capacity of the ink vehicle. This makes it possible to create an ink-receiving layer with an appropriate degree of bleed, which means that affinity can be thought of as the difference between the surface energy of a solid and the surface energy of an ink vehicle. Normally, if the solid surface energy is close to or large than the liquid surface energy, the affinity □ is considered to be large, and the smaller the solid surface energy is than the liquid surface energy, the greater the affinity. As mentioned above, the silica surface is thought to have a very high affinity for water molecules, but treating the surface with a substance that is thought to lower the surface energy, such as fluorine, will reduce the surface energy of the surface treated pigment and the ink vehicle. This is thought to work in the direction of lowering the affinity for dots, and by adjusting the difference in surface energy depending on its content, the extent to which the dots bleed can be adjusted.

The synthetic amorphous silica referred to in the present invention refers to dry process silica produced by thermal decomposition of silicon tetrachloride, so-called white carbon such as metathesis precipitation products with sodium silicate acid, carbon dioxide, ammonium salts, etc., and sodium silicate acid. Silica sol obtained by thermal decomposition or passing through an ion-exchange resin layer, or colloidal silica obtained by heating and diluting this silica sol, or colloidal silica obtained by heating and diluting this silica sol. So-called synthetic products produced by heating at 80°C to 120°C using silica gel, which has primary particles as three-dimensional secondary particles with siloxane bonds, as well as silica sol, sodium silicate, sodium aluminate V-cum, etc., as starting materials. Synthetic silicate compounds mainly composed of silicon dioxide, such as Kirekylar Sheep, are produced by adding sodium fluoride, hydrofluoric acid, hydrogen fluoride gas, silicon tetrafluoride, etc. during the production process or after production, or in the gas phase. By bringing them into contact, they can be reacted to form fluorine-containing synthetic amorphous silica. In this way, the fluorine-containing synthetic amorphous silica produced can be determined by measuring the amount of fluorine by photoelectron spectroscopy (hereinafter referred to as BaOm), which is the ratio of the peak heights of Flm and 812p (Fi
◎ According to the EBOA measurement method, these peaks are thought to be due to atoms existing in the outermost layer of the sample at a depth of 100λ to the root plate. In the present invention, PI measured with l1f80A
It is preferable that the ratio of /5i2p is 0.05 or more, but if it is 1.5 or more, the surface will become too hydrophobic and it will be difficult to apply it as a water-based paint.In the present invention, the above-mentioned fluorine-containing synthetic amorphous silica In this case, the fluorine-containing synthetic amorphous silica is used in an amount of 5% by weight or more, preferably 10% by weight or more of the total pigment.

Inorganic pigments that can be used in combination include, for example, ground calcium carbonate, ground calcium carbonate, kaolin (white clay), talc, calcium sulfate, lithium sulfate, titanium oxide, zinc oxide, zinc sulfide, zinc carbonate, satin white, and silica. White pigments such as acid aluminum, diatomaceous earth, calcium silicate, 'magnesium silicate, synthetic amorphous silica, aluminum hydroxide, alumina, and lithopone, and organic pigments include styrene plastic pigments, acrylic plastic pigments, microcapsules, In the present invention, the ink-receiving layer refers to a coating layer made by mixing the inorganic pigment or organic pigment with an adhesive and providing a layered layer on a support to fill the voids.In the ink-receiving layer. Examples of water-based adhesives used for this purpose include oxidized starch, etherified starch, cellulose derivatives such as carboxymethylcellulose and hydroxyethylcellulose, casein, gelatin, soybean protein, polyvinyl alcohol and its derivatives, maleic anhydride resin, and Conjugated diene polymer latex such as styrene-butadiene copolymer, methyl methacrylate-butadiene copolymer, acrylic polymer latex such as polymer or copolymer of acrylic acid ester and methacrylate ester, ethylene acetic acid Vinyl polymer latex such as vinyl copolymer, functional group-modified polymer latex with monomers containing functional groups such as carboxyl groups of these various polymers, thermosetting synthetic resin systems such as melamine resin, urea resin, etc. Aqueous adhesives such as polymethyl methacrylate, polyurethane resins, unsaturated polyester resins, vinyl chloride-vinyl acetate copolymers, polyvinyl butyral, alkyd resins and other synthetic resin adhesives are used alone or in combination. Adhesive: 2 parts to 100 parts per 100 parts of pigment
part, preferably 5 parts to 30 parts, but the ratio is not limited to leopard as long as it is sufficient to bind the facial mass. However, if more than 100 parts of adhesive is used, the adhesive will form a film, which will reduce the pore structure or make the pores extremely small. After the image is formed on the ink-receiving layer, it is preferable that the image does not flow into water, but in that case, a cationic resin, cationic surfactant, cation-modified inorganic particles, etc. can be added as a water-resistant agent. .

In addition, if necessary, pigment dispersants, thickeners, fluidity improvers, antifoaming agents, foam inhibitors, mold release agents, foaming agents, penetrants, colored pigments, colored dyes, fluorescent whitening agents, and ultraviolet absorbers. , antioxidants, preservatives, anti-piping agents, etc. can also be blended as appropriate.

As the support, a sheet material such as paper or a thermoplastic resin film is used. In the case of paper, it is paper with no buoyant added or with appropriate sizing, and may or may not contain filler.In addition, in the case of thermoplastic film, polyester, polystyrene, polyvinyl chloride, etc. A transparent film such as polymethyl methacrylate, cellulose acetate, polyethylene, or polycarbonate, or a white opaque film filled with white pigment or finely foamed is used. Examples of the white pigment filled with zero light include titanium oxide, calcium sulfate,
Calcium carbonate, silica, clay talc, zinc oxide, and many others are used.

In addition, it is also possible to use so-called whirlpool paper, which is made by pasting these resin films on the paper surface or processing it with molten resin. Corona discharge machining, etc. may be applied. If the ink-receiving layer to be provided on these supports is formed by applying pigment coating liquid, etc., a blade coater or air knife, which is generally used as a coating machine, may be used. Coaters, roll coaters, frudge island coaters, curtain coaters, per coaters, gravure coaters, spray devices, etc. are commonly used. Furthermore, if the support is paper, size press on paper machine, gate row #% x 7'
It is also possible to apply sheets such as dE, flJ, and thas-, which can be used as recording sheets according to the present invention as they are, by simply providing an ink-receiving layer on a support.
It is also possible to impart surface smoothness by passing between roll nips under heating and/or pressure using a parcalender, cross calender, etc. In this case, excessive processing by supercalender processing will reduce the ink absorbency due to the voids between the particles, so the degree of processing will be limited.

Measurements of various physical property values in Examples were carried out in the following manner. First, a Sharp inkjet printer (Iυ-70
0), the image obtained by solid printing with each ink of cyan (0), magenta (M), yellow (Y), and black (B)) was immersed in running water for 5 minutes, and the images before and after immersion were The image density was measured using a Macbeth densitometer RD 514, and the percentage obtained by dividing the density after immersion by the density before immersion was used as a measure of water resistance.◎ Also, the dot diameter is the same as that of a single dot in the black ink area of the same inkjet printer. The area was measured with a dot area meter, the diameter was calculated based on the area assumed to be a perfect circle, and that value was used.Also, the ink absorption speed was calculated using the same printer. Immediately after printing (approximately 1 second), the paper was brought into contact with a paper presser roll and judged by whether stains appeared or not. In addition, the ink absorption capacity was 1/1 for polyethylene glycol (P, IO & 400)/water. The solution was brought into contact with a fixed area of the ink-receiving layer for 10 seconds at 20°C, the excess liquid was removed with blotting paper, and the amount of ink absorbed into the ink-receiving layer was measured. Using the value calculated as the number of grams of ◎, the present invention will be described below with reference to examples, but it is not limited to these examples. In addition, parts and percentages shown in the examples mean parts by weight and 1% by weight.

Example I 100 parts of LBKP was beaten to a furnace water temperature of 400m08F,
8 parts of talc, 2 parts of clay, 0.4 parts of saponified rosin, and 1.8 parts of sulfuric acid were added to make paper with a basis weight of 641/m'' using a fourdrinier machine, and during paper making, it was added with a size press machine. , A base paper was produced by adhering 3 parts of oxidized starch in solid form to 7 m''. @100 parts of fluorine-containing synthetic amorphous silica (tEid 255, manufactured by Fuji Deguin) with an average secondary particle size of 3.5 μm as a pigment, Polyvinyl alcohol (PVA117,
Clan m) Create a concentrated 1f 18% coating solution consisting of the ao part, and use an air knife coater to dry it as a solid content of 1517m
The recording paper of Example 1 was obtained by applying and drying the paper and smoothing the surface by passing it through a super calender. When the coated surface of the obtained recording paper was measured by nsom, Pis/512P = The evaluation results for inkjet suitability are shown in Table 1. Comparative Example 1 The pigment in Example 1 was replaced with fluorine-free synthetic amorphous silica (Syroid 244, average secondary particle size 3.5 μm, manufactured by Fuji Devine). ), except that the recording paper of Comparative Example 1 was prepared in exactly the same manner as in Example 1.◎E of the obtained recording paper
Measurements in BO^ showed no fluorine peak. (71
s7812F=0)O The evaluation results of the obtained recording paper are shown in Table 1〇Examples 2 to 6 Coated base paper with a basis weight of 631/7FL" and a Steckigt size degree of 10 seconds, synthetic silica and Tsubu Seal LP made by Nippon Silica. )100flS, polyvinyl alcohol (PVA1
17 Kuraray Table) Coating liquid consisting of 20 parts solids x 2I
A base paper was created by coating with an air knife coater so that the pigment was 90 parts and 70 parts of synthetic amorphous silica (Tubushial B150, Nippon Silica) as a pigment.
10 parts, 50 parts, 30 parts, 10 parts, and 10 parts, 30 parts, 50 parts, 70 parts, and 90 parts of fluorine-containing synthetic amorphous silica (CyVid 255, manufactured by Fuji Davison) were mixed, and used as an adhesive. 40 parts of polyvinyl alcohol (PVA117, manufactured by Kuraray) were added, and 10 parts of a cationic resin (Polyfix 601 manufactured by Showa Kobunshi) were added and stirred well to make a coating liquid with a concentration of 5% fl'. The coating liquid was smeared onto the coating layer of the base paper described above so that the solid content was 6 I/ba, dried, and supercalendered to make the surface smooth. Table 1 shows the results of evaluating the inkjet suitability of these materials.No fluorine was detected from the surface of the base paper, and from the above examples, the values of Fll/812p and 0.06.
0.13.0.22.0.29.0.38 were obtained.

Comparative Example 2 On the base paper used in Examples 2 to 6, 100 parts of synthetic amorphous silica (m 150, Japanese silica),
Polyvinyl alcohol (PVA117, manufactured by Kuraray) 40
The recording paper of Comparative Example 2 was prepared by smearing the coating liquid consisting of 30% by weight in exactly the same manner as in Examples 2 to 6.Table 1 shows the results of evaluation of this recording paper.

From the results in Table 1, it can be seen that in Examples 1 to 6 in which synthetic amorphous silica containing fluorine was used, the dot diameter was small, the ink absorption capacity was large, and the inkjet suitability was extremely improved. 0 allowed

Claims (1)

[Claims] (1) An inkjet recording paper comprising an ink-receiving layer made of synthetic amorphous silica and an aqueous adhesive on a support, the inkjet recording paper having a 4I characteristic that the synthetic amorphous silica contains fluorine. recoding media. (21 Fluorine Is electrons and silicon 2 by photoelectron spectroscopy
pvt child p1 height (1) ratio (Fls/812p)
The inkjet recording medium according to claim 1, which has a force of 0.05 or more and 1.0 or less◎