JP3028720B2 - Inkjet recording paper - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording material, and more particularly, to a recording material having excellent color development, dot shape, and the like.
The present invention relates to a stiff ink jet recording sheet.

[0002]

2. Description of the Related Art Due to the performance of an ink jet printer using an aqueous ink, especially the improvement of printing speed, resolution, saturation, etc., high-speed absorption of recording materials has been achieved.
Higher properties such as high absorption capacity and regular ink bleeding have been required, and so-called coated papers having an ink receptive coating layer on the surface have been developed.

[0003] For example, Japanese Patent Application Laid-Open No. 62-158084 discloses a method for producing an ink jet recording medium having high aqueous ink absorption, color reproducibility and color density using fine-particle synthetic silica. That is, in order to meet the above-mentioned required characteristics, it is usually practiced to provide a coating layer mainly composed of a white pigment excellent in liquid absorbing property such as fine particle synthetic silica on the surface of a base paper mainly composed of cellulose pulp. Have been.

On the other hand, in recent years, with the expansion of the use of ink jet printers, advertisements mainly using color from office documents such as conventional documents, especially point-of-purchase advertisements (Point-in-time advertisements).
tof Purchase Advertising,
Hereafter, the use as a POP advertisement is spreading. Unlike printing, ink jet recording does not require plate making, so printing can be performed with a small amount and the cost is also easy. Also, as its use as a POP advertisement expands,
It is also used for price cards, displays in showcases, and the like, and there is a demand for thin, thick ink jet recording papers instead of the thin recording papers used in conventional office documents. The POP advertisement is for notifying the buyer of the content, price, and the like of the product, and there have been problems in that the conventional thin recording paper falls down during display or breaks due to natural phenomena such as wind.

Japanese Patent Application Laid-Open No. 5-139023 discloses an ink jet recording paper in which a base paper having a basis weight of 20 to 200 g / m ² is coated with a paint containing fine synthetic silica. Cannot solve the above problem,
There has been no such ink jet recording paper so far.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide a water-based ink jet recording paper which can print a high-quality image at a high speed using a water-based ink-jet printer, and which is firm even after printing. It is assumed that.

[0007]

In view of the above situation, the present inventors have made intensive studies on the waist of the base paper and found that the Gurley stiffness is 400 to 1500 mgf and the thickness is 100 to 3 mm.
By providing an ink receptive coating layer containing a white pigment and a binder resin as main components on a base paper surface of 00 μm, high-quality and high-color images can be obtained when printing by an ink jet method, and the printed matter has more rigidity. They found that they did not fall down or bend even when used in exhibitions and the like, and completed the present invention.

That is, the ink jet recording paper according to the present invention is obtained by forming a paper stock containing cellulose pulp as a main component.
A base paper that has been subjected to a size treatment with a surface sizing agent , and an ink-receiving coating layer formed on at least one surface of the base paper and containing a white pigment and a binder resin as main components. And the Japanese paper of the base paper
I No. Gurley stiffness specified in 40 is 400-1
500 mgf, and the thickness of the base paper is 100
３００300 μm.

[0009] The ink jet recording paper according to the present invention contains cellulose pulp as a main component.
TAPPI No. Gurley stiffness specified in 40 is 4
It is in the range of 00 to 1500 mgf and the thickness is 100
An ink-receiving coating layer containing a white pigment and a binder resin as main components is provided on both sides of the base paper having a thickness of from 300 μm to 300 μm.

The pigment used in the ink-receiving coating layer used in the present invention is preferably a white pigment which is porous, has high ink absorbency, and enables clear color development. Examples of such pigments include fine particle synthetic silica, zeolite, calcium carbonate, calcium silicate, aluminum hydroxide, calcined clay, kaolin clay, talc, white carbon, and organic pigments (plastic pigments), which are generally used in paper coating. Pigments.

The proportion of the pigment used is from 40 to 90% by weight, preferably from 50 to 80% by weight, of the total solid content of the coating layer.
It is. If it is less than 40%, the ink absorbency becomes insufficient,
If it exceeds 90% by weight, the strength of the ink receptive coating layer may be reduced, which is not suitable.

Examples of the binder resin of the present invention include polyvinyl alcohol and derivatives thereof, proteins such as casein, starch, and starch derivatives thereof, and conjugated diene polymers such as styrene-butadiene copolymer and methyl methacrylate-butadiene copolymer. Latex, 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 or cation of these various polymers Functional group-containing modified polymer latex, synthetic resin-based aqueous adhesives such as melamine resin, thermosetting resin such as urea resin, maleic anhydride copolymer resin, polyacrylamide, polymethyl methacrylate, polyurethane Resin-based, unsaturated polyester resin A polymer such as a synthetic resin adhesive such as a polyvinyl butyral-based resin or an alkyd resin-based resin has good adhesiveness with a pigment, and has good affinity with an aqueous ink, so that the liquid absorbing property is improved. Can be

The proportion of the binder resin used in the ink-receiving coating layer is 10 to 60% by weight of the total solid content of the coating layer,
Preferably it is 20 to 50% by weight. If it is less than 10%, the adhesive strength becomes insufficient, and the strength of the coating layer may be reduced. On the other hand, if it exceeds 60%, the adhesiveness is increased, but the use ratio of the pigment is decreased, and as described above, there is a problem in the ink absorbency, which is not suitable.

The pulp material contained in the sheet support used in the present invention is a softwood such as Akamatsu, Kuromatsu, Ezomatsu, Todomatsu or Cedar; a groundwood pulp or a sulfite pulp mainly using broadleaf trees such as beech, hippopotamus, or Shinoki. , Kraft pulp, semi-chemical pulp, chemical ground pulp, refiner ground pulp or waste paper pulp.

The base paper as a sheet support used in the present invention comprises the above-mentioned wood pulp as a main raw material, additives such as an internal sizing agent such as alkyl ketene dimer and alkenyl succinic acid, a sulfuric acid band, and cationic starch. Fixing agents, clay, talc, light calcium carbonate, calcined kaolin, fillers such as aluminum oxide, aluminum hydroxide, titanium oxide, etc., and paper strength enhancers such as polyacrylamide polymers, starch, etc. are appropriately selected and internally added, and known. The base paper formed by the paper machine described above is preferably used.

[0016] In addition, rosin-based, petroleum resin, oxidized starch,
Synthetic resin system comprising two or more copolymers of starch and derivatives thereof such as acetylated starch and hydroxyethylated starch, polyvinyl alcohol and derivatives thereof, styrene, alkyd, polyamide, acryl, olefin, maleic acid, vinyl acetate, etc. And sizing with a surface sizing agent such as a synthetic resin emulsion or wax.
You.

In order to adjust the thickness, known equipment such as a machine calender and a super calender may be used as necessary. The basis weight of the base paper used in the present invention is determined by the final use of the print.
To 300 g / m ^2, preferably it is used as the 70~250g / m ^2.

[0018] JAPAN T of the base paper used in the present invention.
APPI No. The Gurley stiffness specified in 40 is 4
It is 00 to 1500 mgf. Gurley stiffness 400m
If it is less than gf, the paper as a sheet is weak and falls down when used in an exhibition or the like, or is bent by wind or the like, which is not suitable. On the other hand, if it exceeds 1500 mgf, there is no problem of folding resistance, bending resistance, etc., but it impairs the running property at the time of printing and causes problems such as poor printing and poor running property, which is also unsuitable.

The thickness of the base paper used in the present invention is 100
３００300 μm. If the thickness is less than 100 μm, there is a problem such as unevenness of the paper after printing. On the other hand, if the thickness is more than 300 μm, the running problem of the paper during printing occurs, which is not suitable.

In the ink jet recording paper of the present invention, a known coating equipment such as a bar coater or an air knife coater is applied for coating the paint for forming the receptive coating layer. A sheet provided with an ink receptive coating layer on a base paper can be used as it is as the recording paper of the present invention, but it can be treated with, for example, a super calender, a gloss calender, etc. to impart surface smoothness. It is.

The coating amount of the ink-absorbing coating layer obtained in the present invention is determined by the final use, and need not be unnecessarily increased as long as the ink-absorbing property, recording characteristics, storage stability and the like are satisfied. It is appropriately selected from the range of 20 g / m ² and used. If the ink-receptive coating layer is less than 3 g / m ² , the ink absorption capacity is often insufficient, and the image flows out, color bleeds, the image is blurred, the ink is dried slowly, and the ink adheres to the roll. It gets dirty. However, if an ink receptive coating layer exceeding 20 g / m ² is provided, the adhesion to paper becomes weak due to the thick coating layer,
Problems such as clogging of head nozzles often occur, and the cost is high.

[0022]

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% all indicate parts by weight and% by weight.

Example 1 20 parts of light calcium carbonate was added to a slurry of 100 parts of hardwood bleached kraft pulp, and 1 part of carotin starch and 0.2 part of an alkenyl succinic anhydride-based neutral sizing agent were added. mixed and a paper stock, dried to 10% moisture using a Fourdrinier multi-cylinder type paper machine, a 7% solution of oxidized starch by a size press both sides with 4g / m ² coated, dried, up to 7% moisture was produced fine paper basis weight 165 g / m ² and dried. The thickness of the obtained high-quality paper was 250 μm, and the Gurley stiffness was 1342 mgf. One side of the obtained high-quality paper is coated with a paint using a test blade coater in a laboratory.
1 was applied at a rate of 9 g / m ² and dried to form a coating layer, thereby producing an ink jet recording paper.

Paint-1 100 parts of sedimentable calcium carbonate (Univar 70: manufactured by Shiraishi Kogyo) 30 parts of polyvinyl alcohol (PVA117: manufactured by Kuraray)

Example 2 25 parts of light calcium carbonate was added to a slurry of 80 parts of hardwood bleached kraft pulp and 20 parts of softwood bleached kraft pulp, and 0.8 parts of kaotin starch and an alkyl ketene dimer-based neutralizing agent were added. 06 parts were added and mixed well to obtain a papermaking raw material, and the water content was reduced to 10% using a fourdrinier multi-cylinder paper machine.
3 g / m ² of a 7% solution of oxidized starch was applied on both sides by a size press, dried, and dried to a moisture content of 7% to produce a high quality paper of 135 g / m ² of rice tsubo. The thickness of the obtained high quality paper was 152 μm, and the Gurley stiffness was 830 mgf. One side of the obtained high quality paper was coated with paint- ^{2 at} a rate of 10 g / m ^{2 in} a laboratory using a test bar coater and dried to form a coating layer, thereby producing an ink jet recording paper.

Paint-2 Fine silica particles 100 parts (Fine seal: manufactured by Tokuyama Soda Co., Ltd.) Polyvinyl alcohol 25 parts (R-1130: manufactured by Kuraray Co., Ltd.)

Example 3 The high-quality paper produced in Example 2 was subjected to machine calendering.
A high quality paper having a thickness different from that of Example 1 was produced. The thickness of the obtained high-quality paper is 110 μm, and the Gurley stiffness is 540 m.
gf. Using a test bar coater on one side of the obtained fine paper in a laboratory using a test bar coater, the coating material 2 was applied at a rate of 10 g / m ² and dried to form a coating layer, thereby producing an ink jet recording sheet.

COMPARATIVE EXAMPLE 1 20 parts of light calcium carbonate was added to a slurry of 100 parts of hardwood bleached kraft pulp, and 0.7% of carotin starch was added.
Parts, an alkyl ketene dimer-based neutral sizing agent (0.05 parts) was added and mixed well to obtain a papermaking raw material, and the water content was dried to 10% using a fourdrinier multi-cylinder paper machine. 3 g / m ^{2 was} coated on both sides and dried, and dried to 7% moisture to produce a high quality paper of 82 g / m ² of rice. The thickness of the obtained high-quality paper was 93 μm, and the Gurley stiffness was 370 mgf. One side of the obtained high-quality paper was coated with paint-1 at a rate of 9 g / m ^{2 in} a laboratory using a test air knife coater and dried to form a coating layer, thereby producing an ink jet recording paper.

COMPARATIVE EXAMPLE 2 20 parts of light calcium carbonate was added to a slurry of 100 parts of hardwood bleached kraft pulp, 1 part of carotin starch and 0.2 part of an alkenyl succinic anhydride-based neutralizing agent were added. mixed and a paper stock, dried to 10% moisture using a Fourdrinier multi-cylinder type paper machine, a 7% solution of oxidized starch by a size press both sides with 4g / m ² coated, dried, up to 7% moisture It was dried to produce high quality paper of 250 g / m ^{2 in} rice tsubo. The thickness of the obtained high quality paper was 340 μm, and the Gurley stiffness was 1630 mgf. One side of the obtained high-quality paper is coated with a paint using a test blade coater in a laboratory.
2 was applied at a rate of 10 g / m ² and dried to form a coating layer, thereby producing an ink jet recording paper.

Table 1 shows the evaluation results of these coated papers. The following method was used to evaluate the ink jet recording characteristics. Inkjet printer (Desk Write)
rC: manufactured by HP Co., Ltd.), the ink absorbency, the vividness of color development, the printer runnability, the roughness of paper after printing, and the wind resistance were evaluated. In the evaluation of the ink absorbency, the number of seconds until the printed ink dries was measured.以下 indicates 5 seconds or less, Δ indicates 6 to 10 seconds, and X indicates 11 seconds or more.
The vividness of color development was evaluated by visually observing the color development of yellow, magenta, and cyan color inks. Good color development was indicated by 、, insufficient coloration was indicated by Δ, and further poor ones were indicated by ×.

The runnability was determined by inserting 10 sheets of paper into the sheet stack of an ink jet printer and checking the paper feed state without any human intervention.も の indicates that all 10 sheets were fed without problems, Δ indicates that 6-9 sheets were fed, and 0
The wind resistance indicated by x indicates that the paper was fed only up to 5 sheets. For the wind resistance, the paper was firmly fixed vertically on a table, blown with a fan from a distance of 1 m, and visually observed the state of the paper after 3 hours. Was observed.も の indicates that there was no break or bend, Δ indicates that it was not bent but was slightly bent, and x indicates that it was broken. The method of measuring the Gurley stiffness is JAPAN TAPPI No. 40.

As can be seen from Table 1, the ink jet recording sheet obtained according to the embodiment of the present invention has no difference in ink absorbency and color vividness from those of the comparative example, but has a printer running property. With respect to wind resistance, those of the examples of the present invention are better than those of the comparative examples. Also, it was observed that the examples of the present invention were superior to the comparative examples in terms of unevenness after printing.

[0033]

[Table 1]

[0034]

The ink jet recording paper of the present invention is not only excellent in ink absorbency and color development, but also has special strength for the recording paper itself without having to provide a base in a separate opening. (In-place advertisement, such as a price card, etc.).

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-5-139023 (JP, A) JP-A-5-69655 (JP, A) JP-A-61-8379 (JP, A) JP-A-2- 3395 (JP, A) JP-A-7-32722 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B41M 5/00

Claims (6)

(57) [Claims] 1. A paper stock containing cellulose pulp as a main component.
A base paper formed by papermaking and sizing with a surface sizing agent , and an ink-receiving coating layer formed on at least one surface of the base paper and containing a white pigment and a binder resin as main components. , JAPAN TAPP of the base paper
I No. Gurley stiffness specified in 40 is 400-1
500 mgf, and the thickness of the base paper is 100
An ink jet recording sheet having a thickness of from about 300 μm to about 300 μm. 2. The paper stock further comprises an alkyl ketene dimer,
Alkenyl succinic acid, alkenyl succinic anhydride
2. An internal sizing agent selected from size agents.
The ink jet recording paper according to the above. 3. The paper stock further comprises a sulfate band or a cationic precipitate.
The fixing agent according to claim 1, wherein the fixing agent comprises a powder.
Ink jet recording paper. 4. The paper material further comprises clay, talc, light carbonic acid.
Calcium, calcined kaolin, aluminum oxide, hydroxide
Contains fillers selected from aluminum and titanium oxide
The ink jet recording device according to claim 1, 2 or 3,
paper. 5. The paper material is a polyacrylamide-based polymer.
Or a paper strength agent comprising starch.
5. The ink jet recording paper according to 2, 3, or 4. 6. The ink receptive coating layer contains a white pigment in an amount of 40 to 40.
90% by weight, and the coating amount of the ink receptive coating layer is 3 to 2
0 g / m ² The inkjet recording according to claim 1, wherein
Paper.