JPH082096A - Ink jet recording paper - Google Patents

Abstract

PURPOSE:To provide ink jet recording paper for wallpaper excellent in color forming properties, ink absorbability, fire retardancy and tensile strength and having an embossed pattern. CONSTITUTION:The ink jet recording paper consists of base paper based on cellulose pulp and an inorg. pigment and an ink receptive coating layer formed on one surface of the base paper and containing a white pigment and a resin as main components and is characterized by that the base paper contains the inorg. pigment in a ratio of 30-70% by wt. of the base paper and has an embossed pattern on the surface thereof.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording material, which is an ink jet recording sheet used for a printer, a plotter or the like using an aqueous ink, and having excellent characteristics such as color development and dot shape. The present invention relates to a water-based inkjet recording sheet that can record an image, has an uneven pattern formed on a recording paper when printed, and is flame-retardant, and can also be used in interiors such as posters and wallpapers. It is a thing.

[0002]

2. Description of the Related Art Improvements in ink jet printer performance and inks that use aqueous ink have made it possible to obtain clear images and print quality using plain paper as the ink jet paper. However, on the other hand, in order to make print quality, saturation, appearance, and images more attractive, recording materials having more advanced characteristics are required. In particular, due to improvements in printing speed, resolution, saturation, etc., higher-level characteristics such as high-speed absorption, high absorption capacity, and regular ink bleeding are required for recording materials as well, and ink receptivity is increased. So-called coated paper having a coating layer on its surface has been developed. For example, Japanese Patent Application Laid-Open No. 62-158084 discloses a method for producing an inkjet recording medium having high water-based ink absorbency, color reproducibility and color density, which uses fine particle synthetic silica.
That is, in order to meet the above-mentioned required characteristics, it is usually practiced to provide a coating layer containing a white pigment having excellent liquid absorption property such as fine particle synthetic silica as a main component on the surface of a base paper containing cellulose pulp as a main component. Has been done.

On the other hand, in recent years, due to the expansion of uses of ink jet printers, especially in the market development of ink jet plotters, the uses have also spread to interiors such as posters and wallpapers. Unlike ordinary printing, ink jet recording does not require plate making, so printing can be performed with a small amount, and the cost is low. In addition, the accuracy of recent inkjet printers and plotters has increased, and since it is possible to print pictures that are almost the same as normal printing, it has become possible to support various applications such as wallpaper printing. .

Further, as special applications such as wallpaper printing have expanded, so-called fancy paper specifications having various irregular patterns from recording sheets of white coated paper specifications used in conventional office documents have been developed. Ink jet recording sheets are required because of high quality and differentiation of paper.

Japanese Patent Publication No. 53-6243 discloses a method of producing a watermark pattern by coating a base paper with a paint containing a white pigment and the like, but when printing with an ink jet printer, the absorbency is poor. However, there was a problem such as bleeding in the printing section, and it could not be used as an inkjet recording paper. Further, Japanese Patent Publication No. 63-151476 discloses a method of changing the surface condition of an ink jet recording paper by superposing transfer sheets having a desired surface condition in a semi-dried state when a coating layer is provided on the surface of a support. However, there is a problem that the process is complicated and it is not possible to deal with complicated surface conditions (for example, complicated uneven pattern).

Further, since the conventionally used ink jet recording paper uses paper having cellulose as a main component or a synthetic film as a base material, it has a problem of insufficient flame retardancy when used as wallpaper. was there. For example, JP-A-1-192900, JP-B-6-394, and JP-A-3-260196 disclose aluminum hydroxide, clay, talc on one or both sides of a base paper containing an inorganic pigment and cellulose fibers. , A flame-retardant paper for backing vinyl wallpaper, which is provided with a coating layer composed mainly of an inorganic pigment such as kaolin, calcium carbonate, titanium dioxide and a binder. However, since these flame-retardant papers are intended for printing wallpaper, when they are printed by an inkjet printer, they have poor coloring properties, and also have problems in drying properties, ink absorbability, and the like. Therefore, there has been a demand for a wallpaper that solves such problems and enables inkjet recording.

[0007]

SUMMARY OF THE INVENTION The present invention is capable of printing high-quality images at high speed using an inkjet printer and plotter using water-based ink, and is applied to recording paper when printed. The present invention aims to provide an inkjet recording paper that has a relief pattern and can be used as a wallpaper or a poster as it is.

[0008]

In view of the above situation, the inventors of the present invention have made earnest studies on a flame-retardant base paper, suitability for ink jet recording, and a recording paper having an uneven pattern on the surface. By providing an ink-receptive coating layer composed mainly of a white pigment and resin on a base paper composed mainly of an inorganic pigment and cellulose pulp with various uneven patterns, it is possible to print with an inkjet printer / plotter and to record. It was found that the uneven pattern applied to the paper was embossed, and it also had flame retardancy as a wallpaper, and completed the present invention.

That is, the ink jet recording paper of the present invention comprises a base paper containing cellulose pulp and an inorganic pigment as main components, and an ink receiving paper formed on one surface of the base paper and containing a white pigment and a resin as main components. The base paper contains an inorganic pigment in a proportion of 30 to 70% by weight based on the weight of the base paper, and has an uneven pattern on the surface.

The pulp material contained in the sheet support used in the present invention is a softwood such as Akamatsu, Kuromatsu, Ezomatsu, Todomatsu, Japanese cedar, and hardwood such as beech, hippo, cypress and the like, and groundwood pulp and sulfite pulp. , Kraft pulp, semi-chemical pulp, chemi-ground pulp, refiner ground pulp, or used paper pulp. In addition to these cellulose fibers, glass fibers, polyester fibers, aramid fibers and the like can be appropriately used if necessary.

The base paper as a sheet support used in the present invention includes clay, talc, light calcium carbonate, calcined kaolin, aluminum oxide, aluminum hydroxide, titanium oxide and the like as main raw materials in addition to the above wood pulp. Inorganic pigments are added, and additives such as alkyl ketene dimer, alkenyl succinic acid and other internally added sizing agents, sulfuric acid bands, cationic starch and other fixing agents, polyacrylamide polymers, starch and other paper-strengthening agents, etc. are appropriately selected. Then, a base paper which is internally added and made by a known paper machine is preferably used. In addition, if necessary, rosin-based, petroleum resin-based, oxidized starch, acetylated starch, starch such as hydroxyethylated starch and its derivatives, polyvinyl alcohol and its derivatives, styrene, alkyd, polyamide, acryl, olefin, maleic acid, Polymer such as vinyl acetate or 2
The sizing treatment may be performed with a surface sizing agent such as a synthetic resin system composed of one or more copolymers, a synthetic resin emulsion system of these, or a wax system. Further, in order to adjust the thickness, known equipment such as a machine calender and a super calender can be used if necessary.

The content of the inorganic pigment contained in the base paper of the present invention is 30 to 70% by weight based on the solid content of the base paper. Three
If it is less than 0% by weight, the organic components in the sheet increase, so that there is a problem in flame retardancy, and if it exceeds 70% by weight, the sheet strength such as tensile strength and burst strength is lowered, and the feeling as paper,
It is not desirable because it affects flexibility.

The base paper used in the present invention is preferably flame-retardant, and amino phosphates such as melamine phosphate, thiourea phosphate, guanidine phosphate, monoguanidine phosphate, and ringanyl urea, triethyl phosphate, and the like. , Phosphorus-containing organic compounds such as tricresyl phosphate and acid phosphate, halogen-containing organic compounds such as chlorinated paraffin and carbon tetrachloride, halogen-containing amino acid salts such as guanidine hydrochloride and guanidine hydrobromide, vinyl chloride , Vinylidene chloride, halogen-containing polymer compounds such as brominated triallyl phosphate, guanidine sulfamate,
Sulfur-containing amino acid salts such as guanidine sulfate and sulfamic acid, ammonium salts such as ammonium phosphate, ammonium sulfate, ammonium borate, ammonium sulfamate, ammonium chloride, ammonium polyphosphate, inorganic acids such as boric acid and phosphoric acid, boramine Sand, sodium silicate, guanidine tetraborate, guanidine silicate and other alkali metal salts, antimony trioxide,
A flame retardant such as a metal compound such as titanium oxide can be appropriately used. The use ratio of these flame retardants is preferably 10 to 50% by weight with respect to the base paper. If it is less than 10% by weight, it is difficult to obtain sufficient flame retardancy when used as a wallpaper, and if it exceeds 50% by weight, problems such as high cost may occur depending on the flame retardant used.

The base paper of the present invention is required to have an uneven pattern such as a corrugated pattern, a lattice pattern, a checkered pattern, an arabesque pattern, an Ajiro pattern, an Edo pattern, a willow stripe pattern, and a cloisonne pattern.
Although it is possible to print these patterns, since the inkjet paper of the present invention can be used for interiors such as wallpaper, it is better in design to have a three-dimensional pattern in advance. In addition, even if a normal solid printing is performed with an ink jet printer, an effect that a concavo-convex pattern formed on the base paper in advance can be obtained.

The concavo-convex pattern applied to the base paper used in the present invention is a pattern which is preliminarily applied to a dandy roll, a wire, etc. of a paper machine to give a pattern at the time of papermaking, and a pattern in a press part in a wet paper state. There is a method of attaching an emboss mark by a calendar or the like in an off-machine.

The white pigment used in the ink-receptive coating layer of the present invention preferably contains as a main component a porous white pigment having a high ink absorbency and capable of vivid color development.
As such pigment, fine powder synthetic silica is particularly preferable. The finely divided synthetic silica is roughly classified into a wet method and a dry method according to the production method. The wet method can be obtained by using sodium silicate as a raw material and neutralizing with an acid to precipitate silica, and it can be further divided into a precipitation method and a gelation method. Further, the dry method uses silicon tetrachloride as a raw material, hydrogen,
It is obtained by burning with oxygen to precipitate silica.
It is usually called white carbon, and is known as silicic acid anhydride, silicic acid hydrate, and the like. Moreover, these silicic acids are also utilized as aluminum silicate and magnesium silicate depending on the case.

The fine powder synthetic silica used in the present invention preferably has an average particle size of 0.5 to 15 μm. Also,
For the purpose of absorbing ink, it is desirable that the synthetic silica has a high oil absorption, and 100 to 400 ml / 100 g is preferable. Further, other white pigments can be used together depending on the purpose of use of the sheet and the required performance of the printer. These white pigments include precipitated calcium carbonate, ground calcium carbonate, calcium silicate, aluminum hydroxide, zeolite, calcined clay, kaolin clay,
Examples include pigments generally used for paper coating, such as talc, white carbon, and organic pigments (plastic pigments). The usage ratio of such a white pigment is 50 to 90% by weight of the total solid content of the coating layer. If it is less than 50%, the ink absorbency becomes insufficient, or the flame retardancy of the ink-receptive coating layer decreases, and if it exceeds 90%, the strength of the ink-receptive coating layer may decrease, which is not suitable.

Examples of the resin adhesive of the present invention include polyvinyl alcohol and polyvinyl alcohol derivatives modified with silanol groups and the like, proteins such as casein, starch and derivatives such as oxidized starch, styrene-butadiene copolymer, methyl methacrylate- Conjugated diene polymer latex such as butadiene copolymer, acrylic polymer latex such as polymer or copolymer of acrylic acid ester and methacrylic acid ester, vinyl polymer latex such as ethylene-vinyl acetate copolymer, Or carboxyl group of these various polymers, modified polymer latex containing functional groups such as cationic groups, melamine resins, synthetic resin-based water-based adhesives such as thermosetting resins such as urea resins, maleic anhydride copolymer resin-based , Polyacrylamide type, polymethylmethacrylate type, Polymers such as polyurethane resin-based, unsaturated polyester resin-based, polyvinyl butyral-based, and alkyd resin-based synthetic resin-based adhesives have good adhesiveness with pigments and good affinity with water-based inks.
It is preferably used because it improves the liquid absorbency.

Particularly, the resin preferably used in the ink-receptive coating layer of the present invention is a silanol-modified polyvinyl alcohol derivative. Silanolated polyvinyl alcohol is obtained by converting a vinyl compound containing silicon with vinyl acetate and then saponifying it to convert vinyl acetate units into vinyl alcohol and silicon-containing monomer units into silanol groups, respectively. (Japanese Patent Laid-Open No. 58-59203). Since silanolated polyvinyl alcohol specifically and firmly binds to an inorganic pigment such as finely divided synthetic silica, a sufficient coating strength can be realized with a small amount that does not interfere with color development or resolution.

The resin content in the ink-receptive coating layer is 10 to 50% by weight, preferably 10 to 40% by weight, based on the total solid content of the coating layer. If it is less than 10%, the adhesive strength will be insufficient, and there is a concern that the strength of the coating layer will decrease. Meanwhile, 5
When the content exceeds 0%, the adhesiveness increases, but the use ratio of the pigment decreases, causing a problem in the ink absorbability as described above, and increasing the amount of organic components, so that the flame retardancy of the ink-receptive coating layer is reduced. It is not suitable because it decreases.

In addition, pigment dispersants, defoamers, colorants, antioxidants, ultraviolet absorbers, viscosity modifiers,
Crosslinking agent, cationic resin for improving the water resistance of the printed matter after inkjet recording, manufacturing conditions, printing quality,
It is used appropriately according to the required performance.

Known coating equipment such as a bar coater, an air knife coater, a blade coater and a gravure coater is applied to apply the coating material of the present invention. The sheet provided with the ink-receptive coating layer on the base paper can be used as it is as the recording sheet of the present invention, but it can be treated with, for example, a super calendar or a gloss calendar to give the surface smoothness. Is.

The coating amount of the ink receptive coating layer obtained in the present invention is determined by the end use, and does not need to be unnecessarily increased as long as ink absorbency, recording characteristics, storability and the like are satisfied, and It is used by appropriately selecting from the range of 20 g / m ² . If the ink-receptive coating layer is less than 1 g / m ² , the ink absorption capacity is often insufficient, the image runs out, color bleeding occurs, the image is blurred, the drying is slow, the ink adheres to the roll, It gets dirty. In addition, since the amount of ink absorbed by the base paper is large, there is a problem that curling and unevenness are likely to occur. However, when an ink-receptive coating layer having a coating amount of more than 20 g / m ² is provided, the coating layer is too thick to weaken the adhesiveness to paper, which often causes a problem such as clogging of the head nozzle, which further reduces cost. Is also expensive.

EXAMPLES The present invention will be described more specifically with reference to the following examples, but it should be understood that the present invention is not limited by these examples. In the following, parts and% mean parts by weight and% by weight.

Example 1 180 parts of aluminum hydroxide was added to a slurry of 100 parts of hardwood bleached kraft pulp (solid content concentration of aluminum hydroxide: 64% by weight), 0.8 parts of katin starch, alkenylsuccinic anhydride system. 0.13 parts of neutral sizing agent was added and mixed sufficiently to make a papermaking raw material, and the water content was dried to 10% using a Fourdrinier multi-cylinder paper machine. m ^{2 was} applied, dried, and dried to a water content of 7% to produce a fine paper of 120 g / m ² in weight per square meter. The obtained woodfree paper was calendered with an embossing roll having a mesh pattern to produce a woodfree paper having a mesh pattern. On one side of the obtained high-quality paper, a paint-2 was applied in a laboratory using a test bar coater at a rate of 11 g / m ² , and dried to form an ink-receptive coating layer (hereinafter abbreviated as coating layer). Inkjet recording paper was prepared.

Paint-1 Ammonium phosphate 30 parts Oxidized starch 70 parts Paint-2 Fine particle silicic acid 100 parts (Trademark: Mizukasil, manufactured by Mizusawa Chemical Co., Ltd.) Silanolated polyvinyl alcohol 40 parts (Trademark: R-1130, manufactured by Kuraray)

Example 2 An ink jet recording paper was prepared in the same manner as in Example 1 except that the solid content concentration of aluminum hydroxide in the woodfree paper was 35% by weight.

Example 3 180 parts of aluminum hydroxide was added to a slurry of 80 parts of hardwood bleached kraft pulp and 20 parts of softwood bleached kraft pulp (solid content concentration of aluminum hydroxide: 64% by weight), and kaolin starch 1.0 Parts, 0.2 parts of alkyl ketene dimer type neutral sizing agent, and mixed sufficiently to make a papermaking raw material. Using a Fourdrinier cylinder paper machine having a dandy roll with a checkered pattern on the wire to remove water Dry to 10% and press on a size press to apply a 7% solution of oxidized starch on both sides.
g / m ² coating, drying, water content 7%
A fine paper of 05 g / m ² was produced. Paint on one side of the obtained fine paper using a test bar coater in the laboratory.
2 was applied at a rate of 8 g / m ² and dried to form a coating layer, to prepare an inkjet recording paper.

Example 4 100 parts of calcined kaolin was mixed with 100 of hardwood bleached kraft pulp
Part of the slurry (solid concentration of calcined kaolin:
50% by weight), 0.9 part of kao starch and 0.1 part of alkenylsuccinic anhydride-based neutral sizing agent are mixed well and used as a papermaking raw material, and water is removed using a Fourdrinier cylinder paper machine. 1
Dry to 0% and use size press to paint-3 on both sides
g / m ² coating, drying, water content 7%
A fine paper of 00 g / m ² was produced. The obtained high-quality paper was calendered with an embossing roll having a wavy pattern to produce a high-quality paper having a wavy pattern. On one surface of the obtained high-quality paper, Paint-4 was applied at a rate of 9 g / m ^{2 in} a laboratory using a test bar coater, and dried to form a coating layer, thereby preparing an inkjet recording paper. Paint-3 Guanidine sulfamate 30 parts Oxidized starch 70 parts Paint-4 Fine particle silicic acid 60 parts (Trademark: Syloid, manufactured by Fuji Devison) Calcium carbonate 40 parts (Trademark: Brilliant 15, manufactured by Shiraishi Chemical Co., Ltd.) Polyvinyl alcohol 40 parts (Trademark: (PVA 117, made by Kuraray)

Comparative Example 1 25 parts of light calcium carbonate was added to a slurry of 100 parts of bleached hardwood kraft pulp (solid content of light calcium carbonate: 20% by weight), 0.7 part of katin starch, alkyl ketene dimer system. Add 0.1 parts of neutral sizing agent, mix well and use as a papermaking raw material, dry the moisture to 10% using a Fourdrinier cylinder paper machine, and apply a 7% solution of oxidized starch on both sides with a size press. 3 g / m ^{2 was} applied, dried, and dried to a water content of 7% to produce a high-quality paper having a basis weight of 100 g / m ² . Ink-jet recording paper was manufactured by applying a paint- ^{2 at} a rate of 9 g / m <2> on a single surface of the obtained high-quality paper in a laboratory using a test bar coater and drying it to form a coating layer.

Comparative Example 2 900 parts of calcined kaolin was mixed with 100 parts of hardwood bleached kraft pulp.
Part of the slurry (solid concentration of calcined kaolin:
90% by weight), 0.9 parts of katin starch, and 0.2 parts of alkenylsuccinic anhydride-based neutral sizing agent, and mixed well to prepare a papermaking raw material. 1
It was dried to 0%, and a 6% solution of oxidized starch was applied on both sides with a size press at 4 g / m ² and dried to a water content of 7% to produce 100 g / m ² high-quality paper. On one surface of the obtained high-quality paper, Paint-2 was applied at a rate of 11 g / m ^{2 in} a laboratory using a test bar coater, and dried to form a coating layer to prepare an inkjet recording paper.

Comparative Example 3 The high-quality paper obtained in Example 1 was directly used as an ink jet paper.

Comparative Example 4 The high-quality paper obtained in Example 1 was not calendered with an embossing roll, but one side was coated with paint- ^{2 at} a rate of 11 g / m ² using a test bar coater in a laboratory and dried. Then, a coating layer was formed, and calendering was performed with an embossing roll having a wavy pattern to prepare an inkjet recording paper having a wavy pattern.

Table 1 shows the evaluation results of these coated papers. The inkjet recording characteristics were evaluated by the following methods. Inkjet printer (trademark: BJC-820
J, manufactured by Canon) was used to evaluate the ink absorbency and the vividness of color development. Evaluation of ink absorption is
The number of seconds until the printed ink dries was measured.
5 seconds or less is indicated by ◯, 6 to 10 seconds is indicated by Δ, and 11 seconds or more is indicated by x. For the vividness of color development, the color development of yellow, magenta and cyan color inks was visually evaluated. Good color development is indicated by O, insufficient color development is indicated by Δ, and defective color is indicated by X. The presence or absence of the uneven pattern was evaluated by visually observing the pattern after printing. Further, the quality of the paper and the quality of the paper were visually evaluated, and the papers with good quality were shown by ◯, Δ, and x. The tensile strength was according to the method described in JIS-P-8113. The flame retardancy was measured by measuring the carbonization length according to the method described in JIS-A-1322.

[0034]

[Table 1]

As can be seen from Table 1, the ink jet recording sheets obtained in the examples are very excellent in all of ink absorbency, vividness of color development, paper quality, tensile strength and flame retardancy. However, as can be seen from the comparative example, the one having a low inorganic content of the base paper is inferior in flame retardancy (Comparative Example 1), and the one having a high inorganic content is low in strength (Comparative Example 2), and the ink receptive coating layer Those that did not have a poor image quality (Comparative Example 3), and those that had a pattern after the ink-receptive coating layer was provided had a poor ink absorption (Comparative Example 4). Further, since there is no uneven pattern, the quality of the paper is poor (Comparative Examples 1 and 2).

[0036]

INDUSTRIAL APPLICABILITY The ink jet printer recording paper of the present invention is excellent not only in ink absorbency and color developability but also in strength and flame retardancy, and an uneven pattern is formed after printing. It has an effect that it can be used as a special purpose such as interior.

Claims (4)

[Claims] 1. A base paper containing cellulose pulp and an inorganic pigment as main components, and an ink-receptive coating layer formed on one surface of the base paper and containing a white pigment and a resin as main components. An inkjet recording paper, characterized in that the base paper contains an inorganic pigment in a proportion of 30 to 70% by weight based on the weight of the base paper and has an uneven pattern on the surface. 2. The ink jet recording paper according to claim 1, wherein the base paper contains a flame retardant. 3. The ink jet recording paper according to claim 1, wherein fine powder synthetic silica is contained as a white pigment in the ink receptive coating layer. 4. The ink jet recording paper according to claim 1, wherein the resin in the ink receptive coating layer contains silanolated polyvinyl alcohol.