JPH0976631A - Carbonless copying paper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an excellent print-traveling property with a pick strength required for pre-printing and desensitizing ink printing through a multi-sheet copying function and offset printing operation, by avoiding troubles such as paper jam, adherence to the photosensitive drum, gathering in paper feeding ans accommodation failure in the sorter even in printing as lithography paper by means of a laser beam printer. SOLUTION: Sodium salt or ammonium salt of polystylene sulfonic acid having a coating amount of 0.1-1.0g/m<2> is added to a developer coated-layer or coupler coated-layer, thereby obtaining carbonless copying paper with a surface resistivity of 1.0×10<11> ohm or less.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to carbonless copy paper which is widely used for multi-copy slips. More specifically, a printer having an electrophotographic recording system having a multi-copy function by a conventionally known writing or impact printer and having a heat roll fixing process typified by a laser beam printer and an electronic copying machine. Alternatively, the present invention relates to a carbonless copy paper which can be printed by a copying machine.

[0002]

2. Description of the Related Art In general, carbonless copying paper has a base paper coated with a color-developing layer, an upper paper coated with a color-developing layer on the color-developing layer and its opposite surface, and a developer-coating layer. The upper and lower sheets are sandwiched between two sheets, and the required number of middle sheets are sandwiched between the upper and lower sheets for three or more sheets, and the color developer layer and developer layer come into contact. Use it in a collated manner.

The color former layer is mainly composed of microcapsules, a buffer and a binder. Microcapsules are particles of several microns to several tens of microns in which a leuco dye called a color former is dissolved in a non-polar solvent, and these droplets are included in various polymer films, which are destroyed by writing pressure or typing pressure. The inclusions are released. As the buffering agent, polymer particles or inorganic particles that are slightly larger than the microcapsules are used, protecting the microcapsules from unnecessary pressure and friction other than writing pressure and typing pressure, and adjusting the balance between contamination and color development. . In addition to these, various additives may be contained, but various polymers such as latex, polyvinyl alcohol, starch, and acrylic resin called binders are fixed to the base paper to form the color former layer.

The developer layer is mainly composed of a developer, a filler and a binder. The color developer is an inorganic acid such as an acid clay mineral or an organic acid such as a phenol resin, a salicylic acid derivative or a polyvalent metal salt thereof, and has a function of coloring a leuco dye which is a color developing agent. As the filler, a porous and oil-absorptive material that easily transfers a non-polar solvent when the microcapsules are broken is used. Generally, an inexpensive material such as calcium carbonate or kaolin is used. In addition to the above, there are cases where various additives such as an ultraviolet absorber and a water-proofing agent are included in order to improve the image storability, and the binder fixes these to the base paper to form the developer layer.

When a writing pressure or a typing pressure is applied to a carbonless copy paper slip that is gathered so that the color former layer and the developer layer come into contact with each other, the microcapsules of the color former layer are destroyed and the leuco encapsulated therein is contained. The dye is released together with the non-polar solvent, is transferred to the developer layer in contact with each other and chemically reacts with the developer to develop a color. In this way, carbonless copy paper
It is composed of a combination of at least two types of special coating layers called a color developer layer and a color developer layer in order to have a multi-copy function, and the physical properties of the coated surface are generally high-quality paper or PPC (Plain Paper). It is very different from Copy) paper.

With the diversification of user needs, carbon-free copy paper is required to have printability in a laser beam printer in addition to a multiple copy function in a writing or non-impact printer. Printing with a laser beam printer is used for format printing of a large number of slips and preprinting of information unique to each slip, and conventionally it was performed by letterpress printing or offset printing. Very high-speed laser beam printers with computer functions have become widespread and are attracting attention. The advantage of the laser beam printer is that by adding a computer function, it is possible to create and edit print contents on a display called DTP (Desktop Publishing) or DP (Digital Press), and to perform printing by skipping the plate making process. Is.
In addition, there are advantages such as improvement of working environment because the space is reduced and printing ink is not used.

[0007]

Among the carbonless copy papers, those which can be printed at high speed by a laser beam printer are commercially available, but these are used for continuous slips which are supplied as a roll and form printing is carried out. Although it is used, it is not used for single-cut (sheet-fed) printing in plain printing. Since the conventional carbonless copying paper is used as continuous foam paper, even if curling or static electricity occurs, it can be used without causing printing troubles such as jam troubles and poor storage. However, when this is cut and printed with a laser beam printer as flat paper, a large amount of static electricity is generated due to the special coating layer, causing paper jams inside the printer,
Problems such as sticking to the photosensitive drum and improper storage in the sorter section cause work efficiency to deteriorate extremely.

Therefore, the present invention has not only the conventional multi-copy function, but also the pick strength (surface strength) required for preprinting by offset printing or desensitizing ink printing,
Further, it was an object to provide a carbonless copy paper which has a very low static electricity generation even when printed with a laser beam printer as a plain paper and has excellent printing runnability.

[0009]

[Means for Solving the Problems] As a result of intensive studies to solve the above problems, as a result, the surface resistance of the developer layer coated surface or the color developer layer coated surface corresponding to the printing surface of the laser beam printer The carbonless copy paper with a rate of 1.0 × 10 ¹¹ ohm or less generates less static electricity during printing, and the carbonless copy paper satisfying this condition is
The coating amount on the developer layer or the color developer layer is 0.1 g / m
^The present invention has been completed by finding out that it can be obtained by containing ² to 1.0 g / m ² of polystyrenesulfonic acid sodium salt or ammonium salt.

The surface resistivity in the invention of the present application means that the surface coated with the color developer layer of a 10 cm square carbonless copy paper obtained by pre-treating the test paper described in Japanese Industrial Standard JIS P8111 conforms to Japanese Industrial Standard JIS K6911. It means a value measured according to the described method for measuring surface resistivity. The measuring device manufactured by Yokogawa Hewlett-Packard Co.
4329A HIGH RESISTANCE METER and Hewlett Packard 16008A RESISTIVITY CELL were used.

According to this measuring method, the surface resistivity of the surface coated with the color developer layer of the conventional carbonless copying paper was measured.
7-9 × 10 ¹² ohms for medium paper, 2-4 × for lower paper
It was extremely high at 10 ¹² ohms, and when the plain paper (A4 size) was printed by a high-speed laser beam printer, static electricity was generated, and paper jams, corner folds, double feeding, and storage failure in the sorter part occurred.

Therefore, in order to reduce the surface resistivity, sodium chloride, which is the inorganic electrolyte, was added to the developer layer coating material as the cheapest one which does not adversely affect the color developing performance, but the coating amount was 0.5 g. / M ² has a surface resistivity of 1.6
The effect was small at × 10 ¹¹ ohms, and when the coating amount was increased to 0.9 g / m ² , it was 1.4 × 10 ¹¹ ohms, and the surface resistivity almost decreased compared to the increase in coating amount. I couldn't do it. Moreover, as the amount of addition increased, aggregates appeared on the surface of the coating layer with the organic developer, and the state of the coating layer became very poor. Therefore, when various cationic conductive agents were added as the conductive agent having high conductivity, when the effective amount of the conductive agent was added to the developer coating liquid, aggregation of the developer coating liquid was observed, and coating was performed. I couldn't.

Next, when many anionic conductive agents were added to the color developer coating and tried, the surface resistivity could be lowered. However, the degree of decrease in the surface resistivity due to the anionic conductive agent is not so large, and if the addition amount is increased so as to obtain the desired resistivity of 1 × 10 ¹¹ ohms or less, the color development tends to decrease. Therefore, as a result of further investigation on what can obtain the desired surface resistivity with the addition amount as small as possible, the sodium salt or ammonium salt of polystyrene sulfonic acid meets this condition. That is, either the sodium salt of polystyrene sulfonate or the ammonium salt of polystyrene sulfonate or a combination thereof is used in the developer layer to give a coating amount of 0.1 g / m ² to 1.0.
If added so that it is about g / m ² , the surface resistance is 1.0.
It was found that the carbonless copying paper had a frequency of less than × 10 ¹¹ ohms or less, the occurrence of troubles was extremely low in printing with a laser beam printer, and the surface strength was also very high.

As a method of adding to the color developer layer, a usual amount of a polystyrene coating derivative is dissolved in this coating liquid after preparation of the coating liquid, and an air knife coater, bar coater, roll coater, The base paper can be coated with a blade coater, a curtain coater, a gravure coater, or the like.

Further, according to the present invention, even in the case of a carbonless copy paper which requires printing on the surface of the color-developing agent coating layer, the surface resistance of the color-developing agent coating layer is 1 in the same manner as the above-mentioned color developer coating layer. .0
It can be set to be not more than × 10 ¹¹ ohms. Especially for carbonless copying paper with coating layers on both sides such as medium paper, adding polystyrene sulfonate derivative to both coating layers lowers the surface resistivity more than just adding to one coating layer. There is a synergistic effect.

The polystyrene sulfonic acid sodium salt and ammonium salt that can be used in the present invention may be used alone or as a mixture, but may be used in combination with other conductive materials.

As the developer used in the present invention, inorganic solid acids such as acid clay, activated clay, attapulgite and organic developer can be used alone or in combination. As the organic developer, any of the organic acidic substances usually known as an organic developer can be used. Specific examples thereof include phenol formaldehyde resins, phenol acetaldehyde resins, phenol acetylene resins, and polyvalent metal salts thereof described in JP-B-42-20144; JP-B-49-10856.
No. 4, Japanese Patent Publication No. 49-55410, and Japanese Patent Publication No. 51-25
No. 174, benzoic acid, 4-methyl-3-
Nitrobenzoic acid, p-isopropylbenzoic acid, 2,5-
Dinitrobenzoic acid, p-tert-butylbenzoic acid, 4
-Methyl-3-nitrobenzoic acid, salicylic acid, m-hydroxybenzoic acid, p-hydroxybenzoic acid, 3,5-dinitrosalicylic acid, 5-tert-butylsalicylic acid,
3-phenylsalicylic acid, 3-methyl-5-tert-
Butyl salicylic acid, 3,5-di-tert-butyl salicylic acid, 3,5-di-tert-amyl salicylic acid, 3
-Cyclohexyl salicylic acid, 5-cyclohexyl salicylic acid, 3-methyl-5-isoamyl salicylic acid, 5-
Isoamyl salicylic acid, 3,5-di-sec-butyl salicylic acid, 5-nonyl salicylic acid, 2-hydroxy-3
-Methylbenzoic acid, 2-hydroxy-5-tert-butylbenzoic acid, 5,5-methylenedisalicylic acid, acetaminobenzoic acid, 2,4-dihydroxybenzoic acid, 2,
5-dihydroxybenzoic acid, 3,5-di-α, α-dimethylbenzyl salicylic acid, 3,5-di-α-methylbenzyl salicylic acid, 1-hydroxy-2-naphthoic acid, 2
-Hydroxy-3-naphthoic acid, 2-hydroxy-1-
Aromatic carboxylic acids such as naphthoic acid, and metal salts of these aromatic carboxylic acids with metals such as copper, lead, magnesium, zinc, aluminum, tin and nickel;
Polyvalent metal salts of carboxy-modified terpene phenolic resins described in JP-A-3-19486;
Salicylic acid novolac resin described in JP-A-6-58187
2-176875, JP-A-63-53092, JP-A-SHO-6
Copolymers of salicylic acid and alkoxyxylene described in 3-186729 and the like, or compounds such as trialkylbenzene and styrene derivatives, or polyvalent metal salts thereof; oligobenzyl described in JP-A-63-132857. Examples thereof include a metal salt of an aromatic hydroxycarboxylic acid that has been modified.

Although any of these color developers can be used in the present invention, salicylic acid derivatives or polyvalent metal salts thereof are particularly effective. The carbonless copy paper of the present invention is used as a single-sheet (sheet-fed) paper in a printer or a copier having a heat roll fixing process, and unlike the use in a conventional impact printer, the carbonless copy paper is The surface is exposed to a high temperature of 200 ° C. in the fixing process. The salicylic acid derivative or its polyvalent metal salt is suitable as the developer because the color development does not change even under such a high temperature, the surface softening is small, and the surface resistivity is relatively low. It is thought that

As the filler of the present invention, calcium carbonate, kaolin, zinc oxide, titanium oxide, calcium oxide, zinc hydroxide, magnesium hydroxide, magnesium carbonate, aluminum silicate, talc, activated clay, etc. may be used alone or in two kinds. The above can be used together. In the present invention, when calcium carbonate or kaolin is used among these, it is possible to obtain one having excellent smoothness, ink acceptability and coating suitability.

The binder of the present invention is, for example,
Proteins (gelatin, albumin, casein, etc.), sempuns (grain starch, pregelatinized starch, oxidized starch,
Water-soluble natural polymer compounds such as etherified starch, esterified starch) and cellulose derivatives (carboxymethyl cellulose, hydroxypropyl cellulose, methyl cellulose, etc.), polyvinyl alcohol, acrylamide modified Water-soluble synthetic polymer compounds such as polyvinyl alcohol, polyvinylpyrrolidone, polyacrylic acid, polyacrylamide, and maleic acid copolymer can be used. Also, as a latex binder,
Styrene-butadiene latex, acrylonitrile-butadiene latex, acrylic ester latex, vinyl acetate latex, methyl methacrylate
To-butadiene latices and their carboxy-modified (eg acrylic acid) latices can be used.

Any kind of film material can be used for the microcapsules of the color former layer of the present invention.
For example, polyurethane urea resin film, polyamide resin film,
Examples thereof include urea formaldehyde resin film and melamine formaldehyde resin film. As the color former encapsulated in the microcapsules, triphenylmethanephthalide compounds, fluoran compounds, phenothiazine compounds, indolylphthalide compounds, indolylazaphthalide compounds, leukoauramine compounds, spiropyran compounds Examples thereof include compounds known in the art, which are classified into compounds, rhodamine lactam compounds, triphenylmethane compounds, triazene compounds and the like.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION In the carbonless copying paper of the present invention, for example, a lower paper coated with a developer layer is used as an example, and a developer layer coating material is prepared by adding a filler and a binder to the developer dispersion liquid. Adjust and add polystyrene sulfonic acid sodium salt or polystyrene sulfonic acid ammonium salt so that the coating amount may be from 0.1 g / m ² to 1.0 g / m ^2, and apply this to base paper and dry. Manufactured by. With respect to the content of polystyrene sulfonic acid sodium salt or polystyrene sulfonic acid ammonium salt, the effect is extremely weakened when the coating amount is 0.1 g / m ² or less, and almost even when 1.0 g / m ² or more is added. Since there is no change, the optimum content is within the above range. Further, in the present invention, a salicylic acid derivative or a polyvalent metal salt thereof is preferably used as the color developer, and calcium carbonate or kaolin is preferably used as the filler.

[0023]

[Examples] Carbon-free copy papers were prepared according to the following Examples and Comparative Examples, and the surface resistivity was measured, a printing test with a high-speed laser beam printer and a pick strength test of a coating layer with a Prüfbau printing suitability tester were performed. It was (Preparation of capsule slurry) 5% of acrylic copolymer
A hydrophilic solution was prepared by dissolving 10 parts of urea and 10 parts of resorcin in 180 parts of an aqueous solution. Then as an electron-donating color former, 4
Part of crystal violet lactone was dissolved in 120 parts of diarylalkane-based solvent, and the hydrophobic solution was added to the hydrophilic solution obtained above with vigorous stirring to obtain an average particle size of 5
A μ emulsion was obtained. Then, 27 parts of 37% formalin solution was added to this emulsion, and the temperature was raised to 55 ° C. while continuing to stir to 3
After performing the encapsulation reaction for a period of time, it was neutralized with an aqueous ammonia solution to obtain a capsule slurry. (Preparation of standard paint for color former) Starch granules 3 in 200 parts of water
5 parts, microcapsule slurry (adjusted to 25% solid content concentration) 400 parts, 40% latex 7.5 parts, 10%
Was mixed with 110 parts of polyvinyl alcohol while sequentially stirring, and water was further added to finally prepare a standard coating material for the coloring agent layer having a concentration of 18%. (Preparation of standard paint for developer layer) Zinc 3,5-di (α-methylbenzyl) salicylate was uniformly dispersed by a sand grinder to obtain a dispersion liquid having an average particle diameter of 2 μm and a concentration of 20% by weight. 50 parts of this dispersion, 40 parts of 50% heavy calcium carbonate dispersion, and 50% dispersion of kaolin aggregate produced by chemical treatment with oil absorption 59 ml / 100 g 160
Parts were mixed and dispersed, and 250 parts of 10% polyvinyl alcohol was further added as a binder to prepare a standard developer layer coating material.

[Example 1] A developer layer standard paint was prepared by adding 5 parts by weight of sodium polystyrene sulfonate to a standard paint of the developer layer to a dry weight, and further adding water to adjust the paint concentration to 25%. did. Only water was previously applied and dried on the wire surface of the high-quality paper having a basis weight of 60 g / m ² . Next, the developer layer coating material was applied to the opposite felt surface with an air knife coater at a coating rate of about 7 g / m ² and a water content of 4 to 6% at a coating rate of 100 m / min, and then dried. Furthermore, steam damping was applied to the wire surface to correct the curl, and a carbonless bottom paper was obtained. The measured amount of coating is 6.7 g /
m ² and the calculated coating amount of sodium polystyrene sulfonate was 0.24 g / m ² .

Example 2 A lower paper was prepared in the same manner as in Example 1 except that the addition amount of polystyrene sulfonic acid sodium salt was changed to 10 parts. The measured amount of coating is 6.6 g /
m ² and the calculated coating amount of sodium polystyrene sulfonate was 0.46 g / m ² .

Example 3 A lower paper was prepared in the same manner as in Example 1 except that the amount of sodium polystyrene sulfonate added was 15 parts. The actual measured amount of coating is 6.5 g /
m ² and the calculated coating amount of sodium polystyrene sulfonate was 0.65 g / m ² .

Example 4 A lower sheet was prepared in the same manner as in Example 1 except that the amount of polystyrene sulfonate sodium salt added was 20 parts. The actual measured amount of coating is 6.5 g /
m ² and the calculated coating amount of sodium polystyrene sulfonate was 0.84 g / m ² .

[Embodiment 5] A standard coating material for the color-developing agent layer was prepared with a basis weight of 60.
g / m ² of coating weight of 4g / m ² to the wire surface of the quality paper by an air knife coater, the water content was applied and dried at a coating rate per minute 100m so that 4% to 6%. Then, on the opposite felt surface, the color developer layer coating prepared in Example 2 (containing 10 parts of polystyrenesulfonic acid sodium salt)
Similarly, with an air knife, coat and dry at a coating speed of 100 g per minute so that the coating amount is 7 g / m ² and the water content is 4 to 6%, and then perform steam damping on the wire surface to correct the curl. A carbonless medium paper was obtained.
The coating amount of the color developer layer is 6.6 g / m ² , and the calculated coating amount of sodium polystyrene sulfonate is 0.46 g.
/ M ² .

Example 6 A developer layer standard paint was prepared by adding 10 parts by weight of ammonium polystyrene sulfonate to the developer coat standard paint to a dry weight, and further adding water to adjust the paint concentration to 25%. did. Only water was previously applied and dried on the wire surface of the high-quality paper having a basis weight of 60 g / m ² . Next, the developer layer coating material was applied to the opposite felt surface with an air knife coater at a coating rate of about 7 g / m ² and a water content of 4 to 6% at a coating rate of 100 m / min, and then dried. Furthermore, steam damping was applied to the wire surface to correct the curl, and a carbonless bottom paper was obtained. The measured coating amount is 6.8.
a g / m ^2, the coating amount calculated values of sodium polystyrenesulfonate became 0.47 g / m ^2.

[Example 7] A coloring agent layer standard coating material was prepared by adding 10 parts by weight of sodium polysulfonate to a dry weight and further adding water to adjust the coating concentration to 18%. Coating weight of coloring agent layer is 60g / m2 ^{2 The} coating amount is 4g on the wire side of ^high quality paper by air knife coater.
/ M ² and the water content was 4 to 6%, and the coating and drying was performed at a coating speed of 100 m / min. Then, water was applied and dried on the opposite felt surface, and then the wire surface was further subjected to steam damping to correct the curl to obtain a carbonless upper paper. The measured coating amount was 3.5 g / m ² , and the calculated coating amount of sodium polystyrene sulfonate was
It became 0.22 g / m ² .

[Comparative Example 1] A developer layer paint was prepared by adding water to the developer layer standard paint to adjust the paint concentration to 25%. Only water was previously applied and dried on the wire surface of the high-quality paper having a basis weight of 60 g / m ² . Next, the developer layer coating material was applied to the opposite felt surface with an air knife coater to a coating amount of about 7 g /
m ² and water content were 4 to 6% and were applied and dried at a coating speed of 100 m / min. Then, the wire surface was further subjected to steam damping for curl correction to obtain a carbonless lower paper. The actually measured coating amount was 6.7 g / m ² .

[Comparative Example 2] The coloring agent layer coating material was used in a basis weight of 60 g /
The wire surface of the high-quality paper of m ² was coated with an air knife coater at a coating rate of 4 g / m ² and a water content of 4 to 6% at a coating speed of 100 m / min and dried. Then, on the opposite felt surface, the developer layer coating material prepared in Comparative Example 1 (without blending of sodium polystyrene sulfonate) was coated with an air knife at a coating amount of 7 g / m ² and a water content of 4-6.
Coating and drying at a coating speed of 100 m per minute so that
After that, steam damping was applied to the wire side to correct the curl, and a carbonless medium paper was obtained.

[Comparative Example 3] Standard weight of the color-developing agent layer paint was 60
g / m ² of coating weight of 4g / m ² to the wire surface of the quality paper by an air knife coater, the water content was applied and dried at a coating rate per minute 100m so that 4% to 6%. Then, water was applied and dried on the opposite felt surface, and then the wire surface was further subjected to steam damping to correct the curl to obtain a carbonless upper paper. Coating amount is 3.5g / m ²
Met.

[Comparative Example 4] Developer layer A standard paint was prepared by adding 10 parts by weight of an aqueous solution of sodium chloride previously dissolved in water to a dry weight, and further adding water to adjust the paint concentration to 25%. Layer paint. Only water was previously applied and dried on the wire surface of the high-quality paper having a basis weight of 60 g / m ² . Next, the developer layer coating material was applied to the opposite felt surface with an air knife coater at a coating rate of about 7 g / m ² and a water content of 4 to 6% at a coating rate of 100 m / min, and then dried. Furthermore, steam damping was applied to the wire surface to correct the curl, and a carbonless bottom paper was obtained. The measured amount of coating is 6.9g
/ M ² , the calculated amount of sodium chloride applied is 0.4
It became 8 g / m ² .

[Comparative Example 5] The amount of sodium chloride added was 2
A lower sheet was prepared in the same manner as in Comparative Example 4 except that it was set to 0. The actually measured coating amount was 7.0 g / m ² , and the calculated coating amount of sodium chloride was 0.90 g / m ² . The state of the coating layer surface was very poor, and things like aggregates were observed.

<Measurement of Surface Resistivity> The carbonless copying papers of Examples and Comparative Examples were cut into about 10 cm square,
After conditioning the humidity in a test room controlled to a temperature of 20 ° C and a humidity of 65% for 24 hours, in the same test room YHP 4329A HIGT RESISTANC
The surface resistivity of the developer layer coated surface was measured using E METER and HP 16008A RESISTIVITY CELL. The measurement results are shown in Table 1. From the measurement results, in Examples 1 to 7 of the present invention in which sodium polystyrene sulfonate was added,
It can be seen that the surface resistivity of the developer layer is 1 × 10 ¹¹ ohm or less. <High-speed laser beam printer printing test> The carbonless copy papers of the examples and comparative examples were cut into A4 size plain sheets, and about 500 sheets were printed with a high-speed laser beam printer (H-6286 manufactured by Hitachi Koki Co., Ltd.). went. The evaluation results are shown in Table 2. In Examples 1 to 7 of the present invention, no printing trouble occurred. <Pick strength> Printability tester (made by Prufbau)
The strengths of dry and wet picks on the surface coated with the developer layer were visually compared using. The test results are shown in Table 3.

[0037]

[Table 1]

[0038]

[Table 2]

[0039]

[Table 3]

[0040]

INDUSTRIAL APPLICABILITY The no-capone copying paper of the present invention has a coating amount of 0.1 g / m ² to 1 of polystyrene sulfonic acid sodium salt or polystyrene sulfonic acid ammonium salt in the color developer coating layer or color developer coating layer. 0.0 g / m
^{2 By} containing it, the electrical resistance of the coating layer surface, which was very large in the past, was not deteriorated without deteriorating the multi-copy function peculiar to carbonless copy paper and the coating surface state and surface strength which are important during printing. It became possible to lower it. Therefore, since the generation of static electricity during printing is extremely low, problems such as paper jams, sticking to the photosensitive drum, double feeding, and poor accommodation in the sorter when used as flat paper in a laser beam printer The number of occurrences has been extremely reduced, and the efficiency of printing work has been dramatically improved. Further, since the surface strength of the coated surface is high, printability is extremely good even in offset printing.

Claims (3)

[Claims] 1. A carbonless copying paper having a color developer coating layer containing a color developer as a main component or a color developer coating layer containing microcapsules containing a color developer as a main component on a base paper. , Carbon-free copying in which the surface resistivity of the surface of the developer coating layer or the surface of the color developer coating layer pretreated according to JIS-P8111 is 1.0 × 10 ¹¹ ohm or less when measured by the test method of JIS-K6911. paper. 2. The color developer coating layer or the color developer coating layer has a coating amount of sodium polystyrene sulfonate or ammonium polystyrene sulfonate of 0.
The carbonless copying paper according to claim 1, which contains 1 g / m ² to 1.0 g / m ² . 3. The carbonless copy according to claim 1, wherein the developer coating layer contains a salicylic acid derivative or a polyvalent metal salt thereof as a developer and calcium carbonate or kaolin as a filler. paper.