JPH10305655A - Production of information-recording paper blended with mp and the product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make paper usable as IJ papers or PPC papers and effective for the preservation of environment, by applying a coating substance to a front face of the web, and holding a Stoeckigt sizing degree to be a specific time. SOLUTION: An inorganic pigment which is ready to absorb ink is applied by 0.5-3 g/m<2> to at least one face of a paper web in a front face-sizing press process. If a coat amount is not smaller tan 3 g/m<2> , fixing failures or paper dust may be brought about easily by a xerographic printing apparatus. As such, the coat amount is preferably 1-2 g/m<2> . A coating substance including the inorganic pigment is applied only at one face or at both faces of the web. Practically, a material ratio of pulp is 45 parts of GP and 55 parts of LBKP. A Stoeckigt sizing degree is adjusted by a paper machine loading a gate roll to be 30 seconds, and the pigment is spread on the front face. Accordingly, permeation of ink to fibers or absorption of ink in a thicknesswise direction of the paper can be restricted, so that blur is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an information recording paper used for an xerographic or ink jet image printing apparatus, and more particularly to mechanical pulp (hereinafter referred to as MP) which excels in environmental preservation and has a good yield. Containing
The present invention also relates to an information recording sheet having excellent xerographic suitability and ink jet suitability, and a method for producing the same.

[0002]

2. Description of the Related Art In recent years, as a support for an information recording paper (hereinafter also referred to as a PPC paper) used in an xerographic image printing apparatus, MP which is advantageous for environmental protection and has a good yield is often included. It has become. Further, in offices, an image printing apparatus of an ink jet system (a sheet used for the apparatus is also referred to as an IJ sheet hereinafter) which can be easily output from a computer is frequently used. Heretofore, there has not been known any information recording paper applicable to both the xerographic method and the ink jet method which contains a relatively large amount of MP.
The following information is disclosed in the 328289 publication. That is, this known invention relates to a PPC paper applied to a xerographic system, and as a pulp component constituting a support, used newspaper (DIP7) is used as a GP (ground pulp) component in addition to LBKP and NBKP.
The case where the percentage is included is disclosed. MP content is 7 ~
This is because if it is about 8%, there is almost no effect of the MP on ink bleeding and the like.

An information recording sheet applicable to any of the xerographic method, the ink jet method, and the thermal transfer method has been developed, and a support for the recording sheet is described in JP-A-8-72394. The chemical pulp (CP) is almost 100%,
Those containing a significant amount of MP are in an untapped state. Incidentally, as for the xerographic method, Japanese Patent Application Laid-Open Nos. Hei 3-243953, Hei 3-287895, Hei 4-82991, Hei 4-18188, etc. have examined recording papers containing MP. The paper that satisfies the image printing device at the same time has not been examined.

[0004]

As will be described later, the present invention is applicable to both the xerographic system and the ink jet system, and uses a support containing 10 to 40% by weight of MP. I do. According to the view of the present inventors, when a recording sheet containing a relatively large amount of MP is used in an ink jet type image printing apparatus, the M
P has not been chemically treated or is insufficiently chemically treated as compared with chemical pulp (CP), so that the pulp fiber has a property of easily absorbing ink. Therefore, on the paper surface, the fibers themselves absorb the ink, and bleeding of beard-like ink, commonly called feathering, often occurs. Further, in the thickness direction of the paper, the ink is easily absorbed between the fibers as well as the fibers themselves, so that the image tends to become thicker and blurred, and the recorded characters,
It is expected that the numbers and images will be illegible or fuzzy, which will cause practical problems.

[0005] As is well known, fiber materials such as wood, rags and waste paper are mechanically or chemically treated to disintegrate fibers.
Making pulp is referred to as pulping, and the MP mainly based on mechanical treatment includes all or all of the pulping process such as GP, refiner ground pulp (RGP), semi-chemical pulp (SCP) and chemical ground pulp (CGP). Pulp partially processed by mechanical treatment. The yield from wood chips is generally considerably higher than that of CP.
On the other hand, CP is a pulp obtained by chemical treatment represented by kraft pulp, sulfite pulp, soda pulp, and the like, and the yield from wood chips often indicates about 50%. By the way, mechanical pulp has a relatively high yield as described above, and the amount of chemical solution used for pulping is significantly smaller than that of CP, which is advantageous from the viewpoint of preserving the global environment. Needless to say again.

By the way, what kind of means should be taken to obtain a support made of paper containing a considerable amount of the aforementioned MP and applicable to both the xerographic system and the ink jet system? Various studies were conducted. As described above, MP has a tendency that fibers themselves absorb ink more easily than CP, and bleeding ink called feathering tends to occur frequently. In addition, since the ink is easily absorbed even between the fibers in the thickness direction of the paper, it is difficult to avoid the occurrence of so-called "smearing" which tends to be thick in the image.

Therefore, the support containing a considerable amount of the MP is used to prevent the occurrence of ink bleeding and poor image quality when used for IJ paper, or to prevent curl and paper after copying when used for PPC paper. In order to prevent the occurrence of paper dust due to the friction of the feed roll, and problems such as misfeeding due to a decrease in the coefficient of friction, the support itself should be kept in a predetermined range of size and the surface of the support should be maintained. It is intended to cover with an inorganic pigment, thereby speeding up the penetration of the ink in the Z direction (vertical direction) of the paper surface, and at the same time, suppressing and shortening the residence time of the ink in the horizontal direction of the paper surface. In addition, in the formation of the coating layer on the substrate surface and the size imparting the above,
The present invention has been completed under the idea that if the means which can be implemented on-machine during the paper making process can be developed, the above-mentioned combined paper can be provided extremely economically.

As is well known, in a size press process of a paper machine, a two-roll size press is usually used. However, in some cases, a shim-type press is used to improve operability or increase the concentration of a sizing agent. Gate type size presses are also used. In the present invention, for the reasons to be described later, the latter is particularly selected and the surface coating with the inorganic pigment is performed on-machine, and if necessary, the pigment coating and the surface size are simultaneously performed. Thus, the object of the present invention described above is achieved.

[0009]

That is, according to the present invention, even when the above-mentioned MP is contained in a relatively large amount, ink bleeding is small.
It is designed to exhibit its suitability as PC paper. Hereinafter, the means will be described. Of the wood pulp components, the mechanical pulp (MP) component is 10 to 40.
In addition, at the same time as forming the paper, the coating material containing an inorganic pigment is applied to the surface of a paper web using a film transfer type size press in the size press step during the papermaking, and the Sekighito sizing degree ( JIS-P-81
It has been found that the above-mentioned object can be achieved if the (Steckigt sizing degree according to No. 22) is kept at 10 to 40 seconds.

[0010] Incidentally, the size press of the film transfer system specifically refers to a Simsizer (trade name of Sumitomo Heavy Industries, Ltd.-VALMET), a gate roll size press, a metering blade size press, and the like. A size press excluding a two-roll size press. To be more specific about this point, in the conventional two-roll size press, when the speed is increased, the fluid pressure generated on the nip entry side is increased, so that turbulence of the pound of the size liquid and uneven absorption of liquid in the width direction are remarkably generated. At the same time, when papers with low wet strength and sizing degree enter, many problems such as paper breakage have occurred. This is because in a conventional size press, a pound of size liquid was formed between two opposite roll nips, and a predetermined size liquid was applied to the surface of the web through the pound. However, it was only possible to apply a liquid having a relatively low concentration, and it was almost impossible to apply an inorganic pigment or the like to the surface of a sheet of paper. On the other hand, when a film transfer type size press such as the above-described shim sizer or gate roll is used, a coater type preliminary weighing unit is attached without a pound at the press nip. A coating is formed, and the coating is transferred to the paper surface while being pressed into the surface of the web by the liquid pressure of the press nip, so that the inorganic pigment can be applied on a paper machine. The present invention utilizes such a type of film transfer type size press,
Inorganic pigments are applied on a paper machine, thereby improving the defect of the surface properties of the paper derived from the MP formulation.
IJ paper, P economically with on-machine pigment coating
An information recording sheet applicable to both PC sheets can be provided.

More specifically, a coating material containing an inorganic pigment is coated on the surface of the recording paper support in the range of 0.5 to 3 g / m ² by using the above-mentioned film transfer type size press, As a result, an information recording sheet having excellent xerographic suitability and ink jet suitability can be obtained despite containing a considerable amount of MP. In order to prevent ink bleeding which is indispensable for IJ paper, it is preferable to use a neutral rosin size, which is internally added or coated on the surface to keep the degree of Stekigt sizing within a range of 10 to 40 seconds. It is a requirement.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As described above, when a surface is coated on a paper support, in a surface size pressing step, 0.5 to 3 g of an inorganic pigment which easily absorbs ink on at least one surface of a paper web. / M ² (in terms of solid content) by coating, regulates the penetration of ink into the fiber and the absorption in the thickness direction of the paper, and at the same time reduces the whisker-like bleeding (feathering) and the image Reduces bleeding phenomena. By the way, when the coating amount is 3 g / m ² or more, poor fixation and paper dust are likely to occur when applied to a xerographic printing apparatus. Therefore, the coating amount is preferably 1 to ² g / m ^2.
Should be within the range. The coating substance containing the inorganic pigment may be applied to only one side of the paper web, or may be applied to both sides.

The MP used in the present invention is a ground pulp or refiner ground pulp obtained by mechanically pulping wood or wood chips, a chemical ground pulp obtained by impregnating a chemical solution into wood or chips and then mechanically pulping. Alternatively, it is possible to include pulp typified by semi-mechanical pulp and the like pulverized by a refiner after pulverizing the chemimechanical pulp and chips until they become soft, and of course, may include MP derived from waste paper pulp. However. The MP is 10% of the total pulp component
As described above, it is necessary that the content be 40% or less.
It is preferable to set the following.

As pulp other than MP, LBKP, N
Chemical pulp (CP) represented by BKP, LBSP, NBSP and the like, and waste paper pulp are used. The composition ratio can be arbitrarily set according to the type and purpose of the recording paper, except that MP is contained in an amount of 10% by weight or more. In addition, as a raw material of the used paper pulp referred to in the present invention, as shown in the used paper standardization table of the used paper recycling promotion center, top white, ruled white,
Cream white, card, special white, medium white, imitation, fair white, Kent, white art, special extra, separate extra, newspaper, magazine and the like. Further specific examples include printer paper such as uncoated computer paper, heat-sensitive paper, and pressure-sensitive paper, which are information-related paper, and OA waste paper such as PPC paper, art paper, coated paper, lightly coated paper, mat paper, and the like. Covered paper or coated paper such as high-quality paper, high-quality paper, notebooks, stationery, wrapping paper, fancy paper, medium-sized paper, newsprint, paper change, super-hanging paper, imitation paper, pure white roll paper, milk carton, etc. As paper and used paperboard, chemical pulp paper, high-yield pulp-containing paper, and the like can be used. Needless to say, printing, copying,
It goes without saying that it is not particularly limited, regardless of printing or non-printing.

In the present invention, a neutral rosin sizing agent may be used, but other sizing agents may be used. The usual acidic rosin sizing agent is solubilized by dissociation of carboxylic acid in the neutral region. To prevent this, a special hydrophobizing modification is preferred. Use the one that has good properties. As the rosin, those widely used as internal sizes may be used.The main raw material sources are gum rosin obtained by distilling rosin, gum rosin obtained by solvent extraction from old pine strains, and Tall oil rosin separated from conifer craft effluent can be mentioned. It is preferable to use a rosin emulsified with a surfactant or an aqueous polymer, and use a rosin that has been subjected to a hydrophobic treatment. As a fixing agent for the neutral rosin sizing agent, aluminum ion is preferably used. For example, a sulfuric acid band, polyaluminum chloride, sodium aluminate, or the like may be used as an additive.

In general, in the neutral region, the fixing effect of the neutral rosin sizing agent tends to be lost. Therefore, a cationic resin having a high cation value per molecule is used as a fixing agent for the neutral rosin sizing agent. It is good to give a suitable size effect efficiently. As an additive to the support in the present invention, inorganic fillers such as light calcium carbonate, heavy calcium carbonate, kaolin, talc, clay, titanium dioxide, and satin white can be used. Furthermore, in the present invention, as the inorganic pigment to be applied to the surface of the paper web in the size pressing step, in addition to the inorganic materials mentioned as the above additives, for example, finely divided silica, aluminum silicate, diatomaceous earth, kaolinite , Halosite, nacrite, dickite, pyrophyllite, sericite, bentonite, activated clay, and the like. Particularly preferably, a porous substance that easily absorbs ink is used.

Incidentally, when the inorganic pigment is applied to the paper surface as the support, for example, cellulose derivatives such as casein, starch, carboxymethylcellulose, hydroxyethylcellulose, polyvinyl alcohol, polyvinyl pidrine, sodium polyacrylate , Polyacrylamide, etc., a hydrophilic resin swellable to ink, S
It is preferable to use a resin having a hydrophilic portion and a hydrophobic portion in the molecule, such as a BR latex, an acrylic emulsion, a styrene / maleic acid copolymer, and a styrene / acrylic acid copolymer.

Hereinafter, specific examples and comparative examples of the present invention will be described, but the present invention is of course not limited to these examples.

Example 1 A pulp raw material composition was prepared by making 10% by weight of GP as MP and 90% by weight of LBKP as CP to make a paper web, and using "Size Pine NT-80" manufactured by Arakawa Chemical Industries as a neutral rosin sizing agent. Use, concentration 10%
Was internally added to the pulp slurry, and the Stechig sizing degree was adjusted to 30 seconds. In addition, Simsizer (Sumitomo Heavy Industries, Ltd.-VA)
LMET Co., Ltd.) was used to coat an inorganic pigment having the following composition. Kaolin was used as the inorganic pigment, and starch and PVA were used as the binder. The coating amount is as shown in Table 1.

[0019]

Example 2 According to Example 1, the raw material composition ratio was changed to GP2
5 parts and 75 parts of LBKP were used, and the degree of Stighitz was adjusted to 30 seconds. A gate roll was used as the size press.

[0020]

Example 3 According to Example 2, a sheet was obtained in the same raw material composition ratio as in Example 1 according to the details shown in Table 1. The Steckigt sizing degree was adjusted to be 12 seconds.

[0021]

Example 4 According to Example 3, a paper machine equipped with a gate roll was adjusted so that the degree of Stekigt sizing was 30 seconds. The type and amount of the inorganic pigment coated on the surface are as shown in Table 1.

[0022]

Example 5 According to Example 4, the Steckigt sizing degree was 4
It was adjusted to be 5 seconds. Using kaolin as the inorganic pigment and styrene-butadiene copolymer latex as the binder, as shown in Table 1, 1.5 g / m 2
Coating was performed so as to be ² .

[0023]

Example 6 Pulp raw material composition ratio was GP 40 parts, LBKP
In a paper machine equipped with the same shim sizer as in Example 1, the paper size was adjusted to 30 seconds, and the paper size was adjusted to 30 seconds. Using calcium carbonate as an inorganic pigment and styrene-butadiene copolymer latex as a binder, the composition was coated at 1.5 g / m ² as shown in Table 1.

In each of the above Examples except for Example 1, and in Comparative Examples described later, all the sizing agents were applied by surface coating using a size press equipped in a paper machine.

[0025]

[Comparative Example 1] Pulp raw material composition ratio was 45 parts GP, LBKP
In a paper machine equipped with a gate roll, the paper was coated with a pigment by adjusting the degree of Steckigt size to 30 seconds.

[0026]

Comparative Example 2 According to Comparative Example 1, the raw material composition ratio was GP2.
The paper machine equipped with 5 parts, 75 parts of LBKP and equipped with a two-roll type size press has a Steckigt sizing degree of 30.
Adjusted to seconds.

The measuring methods of the test items described in the above Examples and Comparative Examples are as follows. Stockigt size: Measured according to JIS-P-8122. Ink Jet Feather Link Characteristics: Printer uses Canon BJ-
Using 300, vertical and horizontal ruled lines, solid patches, and characters were printed, and feathering and drying properties were evaluated. Feathering evaluation: A pattern of horizontal ruled lines and alphabetic characters are printed on A4 size paper, and visually observed.
PAN TAPPI paper pulp test method No. With reference to the standard bleeding sample used for the pen pen size test method of No. 12, 0
Judgment was made in the range from to. Regarding the evaluation of the results, as judged from the actual use, “5” or higher was indicated as “○”, 4th as “Δ”, and less than 4th as “×”. Drying property: After printing, when the cotton swab is pressed against the solid patch, the time until the ink stops transferring to the cotton swab is measured. 20 seconds or more were rated "x".

PPC characteristics: Using a Xerox Vision-800 as a copier, 100 sheets of the electrophotographic society test chart were continuously copied, and the paper after passing was measured by the following measurement method. is there. Curl value: JAPAN TAPPI paper pulp test method NO. 16 "Paper test method II"
It is a value measured by the following hanging curl measuring method. The judgment was "〇" for 200 mm or less, "△" for 21 to 30 mm, and "x" for 31 mm or more.

Hanging curl measuring method: temperature 20 ± 2
In an environment of 50 ° C. and a relative humidity of 50 ± 2%, the measurement is performed by the following procedure one minute after passing the paper. First, as shown in FIGS. 1A and 1B, the paper after passing the paper is placed horizontally, the curl state is observed, and the curl axis (the vertical curl axis parallel to the long side of the paper or the horizontal curl axis parallel to the short side of the paper) is set. judge. Next, as shown in FIG. 2, the center of one side in the direction perpendicular to the curl axis is picked up with a thumb and a finger, and the paper is suspended vertically. In accordance with the point, the scale S of the A line passing through the edge of the sheet (the distance S (unit: mm) between the B line passing through the O point and parallel to the A line and the A line is read and set as a curl value (1). Next, the center of the opposite side of the sheet is pinched, and the scale of line A passing through the edge of the sheet is read in the same manner to obtain a curl value (2). And the larger curl value is taken as the curl value of the tested paper.The above temperature and relative humidity conditions are standard conditions of the environment where the electrophotographic apparatus (copier) is installed.

Paper powder amount measurement method: B4 size 100
A cellophane tape was brought into contact with the side surface of the zero cut surface, and the amount of paper dust adhering was measured. Judgment was "○" for 20 mg or less, 21
“△” indicates ４０40 mg, and “×” indicates 41 mg or more.

[0031]

According to the present invention, it is possible to obtain an information recording paper which is free from ink bleeding and has almost no feathering phenomenon, irrespective of whether MP is contained in the range of 10% to 40%. That is, on the paper machine, the inorganic pigment is surface-coated by on-machine, so that the penetration of the ink in the Z direction (vertical direction) of the ink is accelerated, the bleeding of the ink in the horizontal direction is suppressed, and the ink is printed on the paper. Therefore, a sheet which can be used as both an IJ sheet and a PPC sheet can be obtained. Also, without it, M
Since a relatively large amount of P is used, a new effect is exhibited in that an information recording sheet that is advantageous for environmental protection can be provided.

[Brief description of the drawings]

FIG. 1A is a schematic view for explaining a hanging curl measuring method, and is a perspective view showing a vertical curl axis of a sheet, and FIG.
Is also a perspective view showing the horizontal curl axis of the paper,

FIG. 2 is a perspective view showing a method for calculating a curl value of a sheet.

[Explanation of symbols]

 1 sheet of paper

[Table 1]

Continued on the front page (72) Inventor Hiromi Ishida 2-12 Kanda Ogawacho, Chiyoda-ku, Tokyo Fuji Xerox Office Supply Co., Ltd. (72) Inventor Taiji Ohashi 2-12 Kanda Ogawa-cho, Chiyoda-ku, Tokyo Fuji Xerox Office Supply Co., Ltd.

Claims (3)

[Claims] 1. A wood pulp component comprising mechanical pulp (M
A paper containing 10 to 40% by weight of the component (P) is applied, and a coating material containing an inorganic pigment is applied to the surface of a paper web by using a film transfer type size press in a size press step in the paper making process. A method for producing an information recording sheet containing MP, characterized in that the degree of Stekigt sizing according to JIS-P-8122 is maintained at 10 to 40 seconds. 2. In a size press step during papermaking, a coating material containing an inorganic pigment in a range of 0.5 to 3 g / m ² is applied to the surface of a paper web using a simsizer or a metering blade size press. The method for producing an information recording sheet according to claim 1, comprising: 3. A mechanical pulp (M) among wood pulp components.
A coating material containing 10 to 40% by weight of the component (P) and containing an inorganic pigment in the range of 0.5 to 3 g / m ² is applied to the surface of the paper web, and the JIS-P-812 of the paper web is further applied.
3. An information recording sheet made according to claim 1 or 2, wherein the degree of Stekigt sizing according to No. 2 is maintained at 10 to 40 seconds.