JP2003173038A - Recording material for electrostatic charge image developing liquid toner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a recording material for an electrostatic charge image developing liquid toner free of running trouble, having good toner fixing property, giving an excellent recorded image and easy to recycle. <P>SOLUTION: The recording material for an electrostatic charge image developing liquid toner is obtained by coating at least one face of a paper substrate using cellulose fibers as stock and having no pigment coating layer with 0.15-0.8 g/m<SP>2</SP>polyethyleneimine resin as a toner fixing improver and the recording material has 30-200" Bekk smoothness and a friction coefficient of 0.40-0.75. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording material used in an electrostatic charge liquid developing system, and more specifically, an electrostatic charge capable of obtaining a recorded image excellent in toner fixing property without running trouble. The present invention relates to a recording material for developing liquid toner.

[0002]

BACKGROUND OF THE INVENTION Traditionally, electrostatic latent images have been developed with dry toner particles or toner particles dispersed in an insulating non-polar liquid. When the dry toner particles escape to the surrounding atmosphere, they float in the air and are harmful to the human body, so they cannot be made into very small particles, and the particle size is about 10 μm, so high image quality can be obtained. I couldn't.
Further, since it has to be fixed to the recording material by melting at a high temperature, high energy is required. In contrast, liquid toner in which toner particles are dispersed in an insulated non-polar liquid requires coloring, charging, fixing, and dispersion stability, but is composed of pigments, resins, and other additives, The toner particles are charged to the opposite polarity to the electrostatic latent image charge, and are attracted to the latent image charge in the electrically insulating liquid. A highly precise image can be obtained because the film is selectively attached to and developed.

In recent years, the demands of consumers have been diversified, and there is a demand not only for printing a large amount of the same product but also for printing a specific product little by little. As a method for printing high-definition images, the gravure printing method is generally used because of its printing speed, print quality, etc.However, since the gravure printing method requires a lot of time and cost for the plate making work process, a small amount of Printed materials were too costly to be practical. In contrast, the electrostatic charge liquid development system using liquid toner does not require a plate making process and is suitable for printing in a small amount.

As recording materials used in the electrostatic charge liquid developing system, plastic films, plastic sheets, pigment coated papers, metals and the like are used, and various improvements have been made. If the recording material is a plastic film, a plastic sheet, or the like, the liquid toner does not penetrate into the recording material, and an excess solvent (toner dispersion medium) remains on the film surface. Therefore, it is necessary to remove the excess solvent in order to fix the toner to the film,
The process of heating the film at high temperature is required. Further, even after removing the solvent by heating, it is necessary to reheat the toner and completely heat-melt the toner resin on the film in order to improve the adhesion between the film and the toner.
Therefore, at present, usable plastic films and plastic sheets are limited to some plastic films or sheets such as polyester resin film having relatively high heat resistance.

The use of pigment-coated paper has also been investigated, but the paper thickness becomes thicker, and the toner permeability, toner transferability, and adhesion are low as in the case of the film, and high-speed printing is performed. Had problems such as the printed surface rubbing and blurring after printing, the toner peeling off with an eraser, and the printing part peeling off with cellophane tape. In addition, there is a problem that there are many paper feeding and discharging problems during continuous printing.

In order to solve the above problems, as a study for improving the fixing property of the toner, an example of using a resin that melts the resin forming the toner at a low temperature, for example, a thermosetting resin, Although there are manufactured examples and the like, there are many cases where the stability of the toner over time or the basic physical properties of the toner for electrophotography are inferior, and a practical level toner has not been realized. Further, in particular, as described in JP-A-4-507148, an intermediate transfer member is formed without directly transferring the developed electrostatic charge developing liquid toner from the electrostatic latent image carrier to the recording material. There is also a method in which transfer is carried out to a film or a sheet to solve the problem of excessive solvent treatment and the fixing property is improved, but sufficient adhesion has not yet been obtained.

[0007] In addition, whether or not recycling is possible in terms of resource saving or environmental protection on a global scale is also an important issue. It is impossible to recycle a film as a recording material, and the treatment after disposal has become a problem recently.
Further, the pigment-coated paper can be recycled, but since it has a coating layer, its treatment requires many treatment steps and energy.

[0008]

[Problems to be Solved by the Invention]
The present invention relates to a recording material for an electrostatic charge developing liquid toner, which has good toner fixability, can provide an excellent recorded image, and can be easily recycled.

[0009]

The present invention includes the following inventions. (1) 0.15 to 0.8 g / m ² of polyethyleneimine-based resin as a toner fixing improving agent on at least one surface of a paper substrate having no pigment coating layer made of cellulose fiber as a raw material
A recording material for an electrostatic charge developing liquid toner characterized by being applied.

(2) The recording material for the electrostatic charge developing liquid toner has a Beck smoothness of 3 defined by JIS P8119.
0 to 200 seconds, the friction coefficient specified in JIS P8147 is 0.40 to 0.75 (1)
A recording material for an electrostatic charge developing liquid toner as described above.

(3) The Clark stiffness in the CD direction measured according to JIS P8116 of the recording material for electrostatic charge developing liquid toner is 13.5 to 30.0 cm, according to (1) or (2). Recording material for electrostatic charge developing liquid toner.

(4) The recording material for blue charge developing liquid toner according to any one of (1) to (3), wherein the polyethyleneimine resin is applied by a transfer roll coater method. .

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION As cellulose fibers used in the recording material of the present invention, hardwood and softwood wood fibers can be used. The pulp manufacturing method is not particularly limited, and the unbleached pulp obtained by a cooking method such as a kraft cooking method, a polysulfide cooking method, and a sulfite cooking method is subjected to delignification treatment in one step or in two or more steps, and then chlorine, caustic soda, hydro It is bleached by a multi-stage bleaching method that is appropriately added with sulfite etc.When considering the load of organic chlorine compounds on wastewater, chlorine dioxide is used as a bleaching method using chlorine dioxide instead of chlorine and chlorine using ozone. A free, multi-stage bleaching method is preferred. Further, mechanical pulp such as GP, TMP and CTMP, and semi-chemical pulp such as SCP and CGP can be used. In addition, hemp pulp, kenaf, and bagasse, which are non-wood fibers, can be mentioned, and waste paper pulp can also be used because of effective use of resources.

The pulp is appropriately selected and is 300 to 50.
It is beaten in the range of 0 ml CSF, and paper is made with a fourdrinier multi-cylinder type paper machine, fourdrinier yankee type paper machine, twin wire type paper machine and cylinder type paper machine.

In addition, an inorganic or organic filler can be used for papermaking. For example, kaolin, talc, clay, calcium carbonate, calcined clay, titanium oxide, diatomaceous earth particulate anhydrous silica, activated clay, zinc oxide, aluminum oxide, aluminum hydroxide, zinc sulfate, barium sulfate, silicon dioxide, inorganic filler of colloidal silica. , Urea formalin resin filler, nylon powder, polyethylene powder, and other organic fillers.

The internally added and externally added sizing agents can be used without particular limitation. For example, a rosin-based sizing agent, an alkyl ketene dimer-based sizing agent, alkenyl succinic anhydride, or the like can be used as the sizing agent, and the sizing agent is added so that the Steckigt sizing degree is 10 seconds or more. Depending on the application, when the Steckigt sizing degree is less than 10 seconds, problems such as ink bleeding occur, which is not preferable. Further, if it exceeds 200 seconds, the fixing of the ink is deteriorated, which is not preferable.
When the alkyl ketene dimer type sizing agent is used as the externally added sizing agent, it is necessary to adjust the friction coefficient to fall within the range of 0.45 to 0.75. Further, as other internally added chemicals, auxiliary chemicals for papermaking such as colorants, paper strength enhancers and retention aids can be used within a range that does not affect the Steckigt sizing degree and friction coefficient.

For the purpose of improving the surface strength, oxidized starch,
Enzyme-modified starch, cation-modified starch, ester starch, ether starch, and other starches, methyl cellulose, ethyl cellulose, carboxymethyl cellulose, methoxy cellulose, hydroxy cellulose, completely (or partially) saponified polyvinyl alcohol, carboxy modified polyvinyl alcohol, silicon modified polyvinyl Polyvinyl alcohols such as alcohol, polyacrylamide, polyvinylpyrrolidone, acrylic acid amide, acrylic acid ester copolymer,
Acrylic amide acrylic acid ester, methacrylic acid copolymer, alkali salt of styrene-maleic anhydride copolymer, isobutylene / maleic anhydride copolymer alkali salt, water-soluble polymer such as casein, polyvinyl acetate, Examples thereof include polyurethane, polyacrylic acid, polyacrylic acid ester, polybutyl methacrylate, and latex of styrene / butadiene copolymer.

The method for externally adding the surface strengthening agent is not particularly limited, and includes an air knife coater, roll coater, reverse roll coater, blade coater, bar coater, gravure coater, kiss roll coater, cast coater, curtain coater, die slot. Coating with an on-machine or off-machine coater equipped with a coating device such as a coater, a chanplex coater, a brush coater, a gate roll coater, a Hamilton coater, a KCM coater, a size press coater, a metalde size press, and a metalde film transfer roll coater. Attach and dry.

In the present invention, a polyethyleneimine resin is used as a toner fixing improver. The electrostatic charge liquid developing system selectively moves the electrostatic charge developing liquid toner to a latent image charge for development, and then heat-treats it on a transfer drum to volatilize the solvent, thereby removing the polyolefin-based liquid toner contained in the liquid toner. This is a mechanism for forming a resin-based film and adhering it to a recording material. Therefore, the adhesion between the polyolefin-based resin-based film and the recording material is centered on the physical adhesive force by which the film softened by heating is fused to the recording material. In such a situation, if a polyethyleneimine resin having a hydrophobic part (polyethylene) and a hydrophilic part (amino nitrogen) in the same molecule is used, the hydrophilic part (amino (Nitrogen) is chemically bonded, and a hydrophobic part (polyethylene) is fused and identified in the polyolefin-based resin-based film to form a crosslinked state. Due to this phenomenon, a strong adhesive force was developed between the recording material and the polyolefin-based resin-based film, and the fixability could be significantly improved.

The polyethyleneimine resin used in the present invention can be used in an average molecular weight range of 250 to 100,000 depending on the difference in the degree of polymerization of ethyleneimine, but if the molecular weight is less than 250, the fixing property of ink deteriorates. When it exceeds 100,000, the solubility, dispersibility, and storage stability become insufficient, which is not preferable.

The polyethyleneimine resin is coated on at least one side of the base paper in an amount of 0.15 to 0.8 g / m ² . There is no limitation on the coating method, and 0.15 to 0.8 can be efficiently used among the methods described as a method usable for coating the surface strength improver.
Any method can be used as long as it can be coated with g / m ^2. However, when a coating method called a transfer roll coater method is used, the amount of polyethyleneimine resin permeated into the base paper is small and the polyethyleneimine resin is evenly present on the outermost surface. Therefore, the effect of fixing the toner by the polyethyleneimine-based resin is further improved, and the toner residue on the blanket of the electrostatic charge liquid / liquid developing system is reduced. The transfer roll coater system includes, but is not limited to, a gate roll coater type, a gate roll coater, a Hamilton roll coater, a KCM coater, and a shimsizer type, such as a metalade size press and a metalade film transfer roll coater. Do not mean.

If the coating amount is less than 0.15 g / m ² , the fixing property of the toner will be poor, and rubbing with an eraser will cause unclear printing, or the printing surface will be peeled off with cellophane tape, which is not preferable. Moreover, even if the coating amount exceeds 0.8 g / m ² , the effect will reach the ceiling and the economy will be poor.

The recording material for the electrostatic charge developing system of the present invention has a Bekk smoothness of 30 to 200 seconds, more preferably 40.
~ 100 seconds. High smoothness is required for recording materials for high-definition printing such as gravure printing, but toner fixing property is important for recording materials for electrostatic charge liquid toner.
It is required to be in the range of up to 200 seconds, more preferably 40 to 100 seconds. When it is less than 30, the fixing property of the toner is poor and unprinted portions are formed during high speed printing, which is not preferable. Further, when it exceeds 200 seconds, the fixing property of the toner is poor, and rubbing with an eraser undesirably blurs the printed portion. Smoothness also affects runnability on the printing press,
Especially important for high speed printing. The smoothness is preferably adjusted by the linear pressure of the calender. The calenders used include on or off machine calenders, on or off machine soft nip calenders, super calenders and the like.

Further, the friction coefficient is important for the running property and is 0.40.
The range of -0.75 is preferable. If it is less than 0.40, the paper is too slippery, so that the paper may be double-fed or idle-fed. Also 0.75
Even if it exceeds the limit, double or empty feed will occur. The runnability also depends on the rigidity of the recording material of the electrostatic charge developing system, and the thickness is 60 to 2
30 μm is preferable, and the Clark stiffness in the CD direction is
It is preferably 13.5 to 30.0 cm. If it is less than 13.5 cm, there is a high possibility that it will be wrapped around a paper feed roll or transfer roll in the printing machine due to lack of stiffness, and if it exceeds 30.0 cm, it will affect not only the paper feed and discharge but also the printing. It is not preferable because it may occur.

The coefficient of friction is preferably adjusted by internally or externally adding a lubricant. Examples of the lubricant to be used include modified polyolefin wax or emulsion, natural fats and oils, stearic acid metal salt and the like.
Further, the Clark stiffness is preferably adjusted by changing the density with the calender. However, it is also effective to adjust the press linear pressure in the water-pressing press step in papermaking.

The recording material for the electrostatic charge developing liquid toner of the present invention preferably has a basis weight of 50 to 220 g / m ² , and an air permeability (JIS P8117) of 40 seconds or less from the viewpoint of preventing curling of printed matter. In particular, the width of the curl due to C-axis, M-axis, and twist when hanging the one printed by a copier is measured, and the A4 vertical surface C-axis curl width is 30 mm or less, M-axis curl width is 25 mm or less, and twist curl. Paper having a width of 20 mm or less is suitable as PPC paper. The whiteness is not particularly limited, but a whiteness of 70 or more is preferable because the printed surface can be seen clearly.

The recording material for liquid toner obtained by electrostatic charge development according to the present invention is a postcard, general printing paper (multicolor compatible), ink jet paper, ink jet paper requiring water resistance, foam paper, PPC paper, thermal transfer receiving paper. It can be used as a text sheet, a release base paper for lamination, and the like.

[0028]

The present invention will be described in more detail based on the following examples. In the examples, “part” means “part by mass” and “%” means “% by mass”. Example 1 LB bleached with ECF from eucalyptus and oak as raw materials
KP100% was beaten into 380 ml CSF, light calcium carbonate (median diameter 4.5 μm, manufactured by Oji Paper Co., Ltd.) 10.0% by mass, alkenyl succinic anhydride (manufactured by National Starch, Fibrin 81) as an internal sizing agent. ) Is 0.07% by mass, and a retention agent (manufactured by Kyowa Sangyo Co., Ltd., Percoll 182) is 0.02% by mass, and the base paper having a basis weight of 64.0 g / m ² Polyvinyl alcohol (PVAK17 manufactured by Denka Co., Ltd.) 0.8 g / m ² and polyethyleneimine resin having a molecular weight of 70,000 (Epomin P1000 manufactured by Nippon Shokubai Kagaku Co., Ltd.) 0.8 g / m ² were prepared on one side of the base paper. After coating with a roll size press coater and drying, a recording material for electrostatic charge developing toner was obtained.

Example 2 The coating amount of the polyethyleneimine resin of Example 1 was 0.4.
A recording material for an electrostatic charge developing liquid toner was obtained in the same manner except that g / m ² was used.

Example 3 The coating amount of the polyethyleneimine resin of Example 1 was 0.1.
A recording material for electrostatic charge developing liquid toner was obtained in the same manner as in Example 1 except that the amount was 5 g / m ² .

Example 4 EBK-bleached LBKP 70% using eucalyptus wood as a raw material
30% of EBK-bleached NBKP made from pine and pine
In 250 ml of CSF, calcium carbonate / talc was 25% at 70/30, and alkyl ketene dimer (SKS259 manufactured by Arakawa Chemical Co., Ltd.) as an internal sizing agent was added to 0.1%.
0% and 0.5% of sulfuric acid band were added and paper was made on a Fourdrinier cylinder paper machine and dried to prepare a postcard base paper with a basis weight of 135.0 g / m ² and polyvinyl alcohol (Denka Corporation) was used on both sides of the base paper. 0.8 g / m ² per side of PVAK17) made of polyethyleneimine, and 0.8 g per side of a polyethyleneimine-based resin having a molecular weight of 70,000 (Epomin P1000 made by Nippon Shokubai Chemical Co., Ltd.)
/ M ² on both sides to obtain a recording material (for postcards) for electrostatic charge developing toner.

Example 5 0.40 g / m ^{2 of} polyvinyl alcohol (PVAK17 manufactured by Denka Co.) was applied to one side of the base paper obtained in Example 5.
Polyethyleneimine resin having a molecular weight of 70,000 (Epomin p1000 manufactured by Nippon Shokubai Kagaku Co., Ltd.) was coated on both sides with a gate roll coater so as to be 0.4 g / m ² and dried, followed by recording in the same manner as in Example 1 for electrostatic charge developing toner. I got the material.

Comparative Example 1 A recording material for an electrostatic charge developing liquid toner was obtained without coating the base paper of Example 1 with a polyethyleneimine resin.

Comparative Example 2 The base paper of Example 1 was changed to a biaxially oriented polypropylene film having a thickness of 25 μm, and a polyethyleneimine resin (Epomin P1000 manufactured by Nippon Shokubai Kagaku Co., Ltd.) was gravure so as to be 0.8 g / m ^2. Coating with a coater gave a system recording material for electrostatic charge developing liquid toner.

Comparative Example 3 The coating amount of the polyethyleneimine resin of Example 1 was 0.1.
A recording material coated with an electrostatic charge developing system was obtained in the same manner as in Example 1 except that the recording material was changed to g / m ² .

Comparative Example 4 The base paper of Example 1 was changed to a pigment coated paper (Royal Coat manufactured by Oji Paper Co., Ltd.) with a basis weight of 81.4 g / m ² , and a polyethyleneimine resin (Epomin P1000 manufactured by Nippon Shokubai Chemical Co., Ltd.) was used.
1.2 g / m ² coating was carried out with a gravure coater to obtain an electrostatic charge developing system recording material.

Table 1 shows the physical properties of the recording materials to be recorded in the electrostatic charge developing systems obtained in Examples 1 to 8 and Comparative Examples 1 to 5 and the results of the following evaluations. (Thickness) Measured according to JIS P8118 (Smoothness) Measured according to JIS P8119 (Friction coefficient) Measured according to JIS P8147 horizontal method (Stiffness) Measured according to JIS P8116 (Air permeability) According to JIS P8117 Measurement (Steckigt sizing degree) Measurement according to JIS P8122

(Printability) An image was output by an electrostatic charge liquid developing electrophotographic copying machine (E-PRINT 1000, manufactured by Indigo, Israel). The reflection density of the solid black portion of the obtained image was measured by a reflection densitometer (“Macbeth RZ-918” manufactured by Macbeth Co.). (Cellophane Tape Peeling Test) After the cellophane tape (Cellophane (R), manufactured by Nichiban Co., Ltd.) was attached to the solid black print portion, the state of the print portion when peeled off was evaluated. (Eraser resistance test) A character printed portion was rubbed with an eraser (PE-04A manufactured by Tombow Pencil Co., Ltd.) 20 times to evaluate the printed state.

(Running test) Electrostatic charge liquid development Electrophotographic copying machine (manufactured by E-PRINT 1000 indigo)
After continuous printing for 1 hour, the presence / absence of paper feeding / discharging trouble was evaluated. (Measurement of curl after copying) A monochrome copy machine (Docutech 135 manufactured by Xerox Co., Ltd.) was used to perform continuous copying of 30 sheets on one side using the original image consisting of only black characters as the copy source.
The ten sheets from the end were suspended vertically as a bundle, and the curl in the paper flow direction (C-axis curl), the curl in the direction perpendicular to the paper flow (M-axis curl), and the twist were measured. The size to be copied was A / 4 length, the maximum curl width was evaluated in mm for curl measurement, and the twist measurement was evaluated in mm as the difference between curl measurement values at both ends.

(Evaluation of Blanket Stain) Blue Charge Liquid Developing Electrophotographic Machine (Publisher 4000 Indi)
A3 full-color printing was performed on 4,000 sheets (manufactured by Go Co.), and the residual stains on the non-image area blanket were evaluated according to the following criteria. : Almost no dirt: Partially soiled: Entire surface is soiled x: Entire surface is heavily soiled

[0041]

[Table 1]

[0042]

As is apparent from Table 1, the recording material of the electrostatic charge development system coated with polyethyleneimine in an amount of 0.15 to 0.8 g / m ² on one side is excellent in toner fixability, especially abrasion resistance such as eraser, It is a recording material with excellent electrostatic charge development system that can be recycled without any paper feeding / discharging trouble.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Tomofumi Tomoyoshi             Made by Oji 1-10-6 Shinonome, Koto-ku, Tokyo             Paper Co., Ltd. Shinonome Research Center

Claims (4)

[Claims] 1. A paper substrate having no pigment coating layer made of cellulose fiber as a raw material, and a polyethyleneimine resin as a toner fixing improving agent in an amount of 0.15 to 0.8 g on at least one side.
/ M ² coating, recording material for electrostatic charge developing liquid toner. 2. A recording material J for the electrostatic charge developing liquid toner.
Beck's smoothness specified in IS P8119 is 30.
2. The electrostatic latent developing liquid toner recording material according to claim 1, which has a coefficient of friction of 0.40 to 0.75 as specified in JIS P8147 for .about.200 seconds. 3. A recording material J for the electrostatic charge developing liquid toner.
3. The recording material for an electrostatic charge developing liquid toner according to claim 1, which has a Clark stiffness in the CD direction of 13.5 to 30.0 cm according to ISP8116. 4. The recording material for a blue charge developing liquid toner according to claim 1, wherein the polyethyleneimine resin is applied by a transfer roll coater method.