JPH0299696A - Optically readable back-carbon copying slip and paper therefor - Google Patents

Abstract

PURPOSE:To obtain the objective copying slip having excellent readability by optical character reader and copying performance and resistant to deterioration with time by forming a paper-layer structure containing plural fillers in the paper and coated with a specific coating agent. CONSTITUTION:The objective paper having a variation coefficient of the reflection density of <=0.20 and a dynamic impregnability of a vehicle liquid for carbon ink of <=11ml/m<2> in terms of transfer amount at a contact time of 50msec has a paper structure produced by using a paper having a basis weight of 35-75g/m<2> and containing a paper-making filler added to a paper pulp, incorporating the paper with 5-25% of a filler having high oil-absorption (e.g., CaCO3 or synthetic silica) and 1-20% of a filler having high light-scattering coefficient (e.g., titanium dioxide or urea resin) and coating both sides of the wire of the above paper with 0.5-3.5% of a coating agent composed of a film-forming polymeric substance (e.g., starch or PVA) and having barrierness to carbon ink.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of the Invention) The present invention relates to a carbon-backed copying form with excellent readability by optical reading devices such as OCR and OMR, and its paper.

(Prior art) A plurality of forms that can be copied are stacked in a set, and carbon ink is applied to the back side of each form as a copy form that allows necessary information to be written on each form simultaneously by hand or using an impact printer, etc. Back carbon copy forms that are printed and copied to lower-level forms via this ink,
Carbonless copy forms are known in which a large number of encapsulated dyes are applied to the paper surface, and printing pressure impregnates the dye inside the capsules into the paper, and reacts with a color developer in the paper to develop color.

This type of copy form is very convenient for business processing, as each form can be peeled off after filling in the necessary information and used as a copy for business use or for customers. It is used in the field of deposit withdrawal (-a creed that is often used as a prescribed insert form in business, etc.).

Incidentally, in recent years, computers have developed and spread rapidly, and business operations are being streamlined by reading various data using optical reading devices such as OCR and OMR, and manually processing the data on a computer. .

Although the introduction of computers is a very effective means of streamlining business processing, on the other hand, the use of duplicate forms such as back carbon copy forms or carbonless copy forms that have been used in the past has become more effective. The problem has arisen that it cannot be used.

In other words, an optical reader that manually inputs data to a computer recognizes information by shining light onto the data surface and optically or electrically processing the partial differences in reflectance. For example, when data written on a back carbon copy form is read, accurate reading becomes impossible.

In other words, conventional carbon-backed copy forms have the advantage of being excellent in copyability and can be produced at low cost. There are many large voids scattered throughout the paper, and the barrier properties against carbon ink are not sufficient, so the carbon ink printed on the back side of the paper comes out onto the front side of the paper, causing what is called a strike. A through phenomenon is occurring.

In addition, because the reflectance of the paper is not high, especially when printing with black back carbon ink, a so-called show-through phenomenon occurs in which the carbon ink printed on the back side appears faintly transparent on the front side of the paper. There is.

Therefore, when an optical reader reads the data entered on the back carbon copy form, the optical reader detects the difference in reflectance between the printed part and other parts, so-called PC8.
(Direct PrinL Contrast Signal)
cannot be clearly detected and the written data cannot be read accurately.

By the way, the commonly used reverse carbon copy form (manufactured by Mishima Paper Co., Ltd.; copy paper with a basis weight of 50 g/m')
The coefficient of variation of the reflective optical density on the surface of the paper and the reflectance of the back carbon printed part 2 Vehicle liquid for carbon ink (hereinafter referred to as "vehicle liquid") The OD (optical density) of an A2 grade coat made by Sanyo Kokusaku Pulp Coating was set to 0, and the OD was measured at 30 points in a field of view of 100 μm x 200 μm, and the coefficient of variation was calculated.

The paper surface reflectance of the back carbon printing part is Macbeth Pudding! - Reflectance was measured using a contrast meter PCM-II with a black backing plate and an F filter (670 nm).

Dynamic permeability of vehicle liquid is J-TAPPINo.

51-87, mineral oil for back carbon ink (viscosity 100 centivoise, surface tension 31 dynes/cm (
At 20°C)) was transferred for a contact time of 5 Qmsec, and the amount of transfer was set to 4. On the other hand, unlike the -1-2 back carbon copy form, the carbonless copy form does not have a strike-through or show-through effect. This phenomenon does not occur and optical reading is possible, but since the color development mechanism uses the dye I) inside the capsule and a color developer, the color development progresses from the cut surface when creating the form, and the printed area The drawback is that Nagato deteriorates severely over time and cannot be preserved.

Moreover, this copy form cannot avoid high costs due to the encapsulation of the dye, so it is a big loss and is not suitable as a copy form for consumption.

(Invention or problem to be solved) As mentioned above, the currently used copy forms such as back carbon copy forms or carbonless copy forms are used as copy forms for optical readers or in large quantities for optical readers. It is not suitable as a copy form used for.

The inventor of the present invention focused on the fact that history carbon copying forms can be manufactured with good copyability and low cost, and as a result of intensive research, it was discovered that paper made under specific paper quality conditions and characteristic value ranges is optically The present invention was completed by discovering that the reading characteristics are excellent.

In general, the optical reading characteristics of back carbon copy forms are improved by -1.
In order to prevent strike-through and show-through, the general formula for liquid penetration is as follows:
For example, in Lucas wash, it is better to reduce the diameter of the voids or to lengthen the penetration distance of the carbon ink.

Therefore, in order to reduce the diameter of the voids, it is possible to impregnate the paper with chemicals such as PVA, coat the surface of the paper, or advance the beating of the pulp.
In either case, the voids are filled with polymer, pulp fines, or fibrils, resulting in a problem in that the opacity of the paper decreases and show-through is more likely to occur.

On the other hand, in order to prevent show-through, it is possible to increase the thickness of the paper. In this case, the permeation distance of the carbon ink becomes longer, so the carbon ink and vehicle liquid are drawn out to the surface of the paper. This increases the opacity of the paper, but it also increases the thickness of the paper, which poses problems such as poor copyability as a form.

This invention was made in view of the problems mentioned in item 1 above, and its purpose is to provide a low-cost copy form that has excellent copyability and optical readability, and can be consumed in large quantities. This is the purpose.

(Means for solving the problem) J l5X9004 has a reflectance of 7 for optical reading paper.
It is stipulated that the reflectance is 0% or more, and therefore it is necessary to set the reflectance to the same level or higher even in the optically readable back carbon copy form.

The paper quality conditions for this require that the texture of the paper on the back carbon printing part be uniform and have high barrier properties.As for the uniformity of the texture, the surface of the paper with the black backing needs to be uniform. The coefficient of variation of the optical density measured by a microdensitometer is 0.2
It needs to be 0 or less.

As for barrier properties, it was found through experiments that the dynamic permeability of the vehicle liquid must be 11 ad/rn' or less at 50 msec.

The filler used in the present invention is carbon ink normally used for back carbon copy forms (for example, Teikoku Ink Manufacturing ■BFL8
The main fillers are a filler with high oil absorption that can prevent the penetration of ink (920 letterpress ink), and a filler with a large scattering coefficient for light read from an optical reader.

Calcium carbonate is a highly oil-absorbing filler.

It is selected from synthetic silica, calcined kaolin, urea resin, etc. This filler is preferably incorporated into the paper in an amount of 5 to 25% relative to the paper, and if it is less than 5%, it will not be able to prevent the penetration of the vehicle liquid and will have an adverse effect on optical reading. Furthermore, if the paper is 25% or more, the fiber bond becomes weak, the paper strength and stiffness decrease, and the paper cannot function as a form.

The filler for increasing the opacity scattering ability of the entire paper is selected from those having a large scattering coefficient, such as titanium dioxide and urea resin. This filler is added to the paper for paper 1 to 2.
It is preferable to add internal content in the range of 0%; below 1%, the opacity and scattering ability of the paper will decrease too much, which will have a negative effect on optical reading, and above 20%, the strength and stiffness of the paper will decrease, making it difficult to use as a form. The function becomes impossible.

Furthermore, - the above-mentioned filler is added in a larger amount to the felt side (the printing side when the paper is used as a form) than to the wire side of the paper; In other words, this can be achieved by controlling retention.

As for the pulp, LBKP, which has been commonly used in the past, may be used, but the strike-through show-through value must be kept low in order to ensure duplication properties as a form and at the same time to ensure optical properties as a form for optical reading. In order to satisfy both conditions at the same time, a freeness level of 9 basis weight is required.

In other words, it is preferable that the basis weight is set in the range of 35 to 75 g/rrI'; if the basis weight is less than 35 g/rd, the paper quality will be too thin for copy forms, causing problems such as tearing and strike-through during copying. .

Further, if the paper is less than 75g/rr1', it becomes too thick for a form, and although strike-through and show-through can be prevented, the copyability of the form deteriorates.

Furthermore, the beating conditions are as follows: Beating to a freeness of 75' SR, exceeding the freeness of 35° SR for normal high-quality paper;
To reduce the porosity in paper and to make the pore diameter as small as possible.

In the coating process, film-forming polymers such as starch, PVA, sulfur/lium alginate, and CMC are applied to the wire side of the paper to ensure barrier properties against carbon ink and removability of carbon ink. A large amount of substance is applied.

Note that after that, calendering may be performed to control the smoothness and thickness of the paper, if necessary.

(Description of Examples) The present invention will be described below using Example 1 and Comparative Examples 1 and 2.

Incidentally, various data were measured in the following manner.

○Basic weight, measured in accordance with JISP8124.

○Thickness, measured in accordance with JI 5P8118.

O opacity was measured using a photovolt reflectometer in accordance with JISP8138.

Coefficient of variation of O reflection optical density; black backing using a Sakura microdensitometer, A2 manufactured by Choyo Kokusaku Pulp ■
100 μm x 200 with the OD of grade coated paper as 0
Each OD was measured at 30 points in a μm field of view, and the coefficient of variation was calculated.

○Surface reflectance of back carbon printed part: Using Hitachi Self-Recording Spectrophotometer Model U3120, black backing was applied to 380
The reflectance was measured under a wavelength range of nm to 900 nm.

However, the wavelength range for comparison with the comparative example was 670 nm.

Dynamic permeability of O backside; J-TAPPINo, 51-8
7, mineral oil for back carbon ink (viscosity 100
centipoise, surface tension 31 dynes/am (a t
20°C) for a contact time of 50 msec, and the amount of transfer was measured.

Example 1 - (Paper making conditions) Puff 11 companies (f2l; LBKP 10
0% beating; Freeness 75° SR filler; Calcium carbonate: 23% to pulp; titanium dioxide: 15% to pulp; Sizing agent; 1 pair to alkyl ketene dimer: 0.3% pulp (coating agent conditions) Coating agent: l starch 15 % PVA 1% Water resistance agent 1% Water 83% By making the paper under conditions of 83% or higher, and controlling so-called retention, which adjusts the amount of water removed from the wire side of the paper machine during papermaking, the wire side is formed on the felt side. A larger amount of filler was added internally than on the felt side, and 0.7 g/rr of coating agent was added on the felt side.
r.Apply 1. coating agent to the wire surface side. It was coated at a ratio of 0 g/rri' to obtain paper (2) having the following paper properties.

(Paper quality characteristics of paper ■) Basis weight: 62g/Thickness: 78μm Smoothness: Felt surface 75sec/10mQ wire surface 20sec/10T1 Reflection optical density coefficient of variation: 0.099 Opacity: 88% Filler filling rate: Felt Side 10% Wire side 4% Next, carbon ink (Teikoku Ink Manufacturing Co., Ltd. BFL8920 Letterpress ink) was printed on the wire side of this paper using a letterpress rotary printing method under the following conditions, and a back carbon copy form (form ■ ) was obtained.

The quality characteristics of this form ■ are as follows: a. Surface reflectance (carbon printed portion on the back); 84.0% b. Dynamic permeability on the back surface; 10. 6vJ1/rr'1
'(a t 50 msec).

Comparative Example 1 - As Comparative Example 1, a conventionally used general copying paper, a copying paper with a basis weight of 50 g/m' manufactured by Mishima Paper Co., Ltd., was selected.

The analysis results of this product are shown in correspondence with Example 1 above.

(Paper quality characteristics) Basis weight: 50 g/rTl' Thickness: 59 μm Smoothness: Felt surface 150 sec/10 pheasant wire surface 75 sec/10 mu Coefficient of variation of reflective optical density, 0.222 Opacity: 86% Filler filling rate: Felt surface 10% Wire side 4% (The above filler is of a different type from the filler in Example 1.) When carbon ink was printed on the back side of this paper under the same conditions as in Example 1, The quality characteristics are as follows.

a Surface reflectance (back carbon printed part); 69.2% b Dynamic permeability of the back surface; 8. OTu/rrr'(
Comparative Example 2 In Comparative Example 2, a 1-1 texture paper manufactured by Nanyo Kokusaku Pulp G-TO Seisaku with a weight of 55 kg was selected as a commonly used texture paper.

The analysis results of this product are shown in correspondence with Example 1 above.

(Paper quality characteristics) Basis weight: 64.5g#y? Thickness: 82.6B1m Smoothness: Felt surface 45sec/10y, Q wire surface 40sec/10v & Coefficient of variation of reflective optical density: 0.262 Opacity Near 3% Filling rate: Felt surface 3% Wire surface 2% (Note: , - The above filler is of a different type from Example 1.) The quality characteristics when carbon ink is printed on the back side of this paper under the same conditions as in Example 1 are as follows. .

a Surface reflectance (carbon printed portion on the back); 52.9% b Dynamic permeability of the back surface; 14. 5va/rrr(a
t 50 msec)'' - A table of correspondence of paper quality characteristics of the sheets obtained in Example 1 and Comparative Examples 1 and 2 is as follows.

Table 1 Table 2 - The results of an optical reading experiment of a back carbon copy form having the quality characteristics as described above are as follows.

Further, the results of optical characteristic analysis of back carbon copy forms produced using each of the above-mentioned papers are as follows.

As is clear from the above results, the paper according to the present invention has a basis weight of 62 g#r+' and a freeness of 75.
°The paper is beaten with SR, and 23% of fillers with high oil absorption such as calcium carbonate and synthetic silica, and 15% of fillers with high light scattering coefficients such as titanium dioxide and urea resin are internally added to the paper. In addition, a paper layer structure is obtained by coating the wire surface of the paper with 1°0 g/rn' of a coating agent such as starch, PVA, etc., which is a film-forming polymeric substance and has barrier properties against carbon ink. As a result of paper making, it has outstanding properties in terms of optical readability, copyability, and paper passing.

In other words, the formation is uniform, there is no unevenness in optical density, and the dynamic permeability of the vehicle liquid is 11v1/, which has the following barrier properties at 50 msec, and the average strike-through diameter is 15.
~20μm, and the average distribution value is 200m (less than 5 pieces per 200m, and the reflectance of the paper surface is 380mm~90m)
Paper with excellent optical properties of 75% or more in the 0 nm wavelength region could be produced.

Therefore, when a back carbon copy form is produced using this paper, it provides a back carbon copy form with excellent optical readability that can ensure high contrast with printed characters and uniform reflectance. can do.

(Effects) The paper according to the present invention has a uniform texture, no unevenness in optical density, has a high barrier property of less than 11π loss/ha at a dynamic penetration rate of 5 Qmsec, and has a like-through average pore diameter of 15 to 20 μm. Therefore, the average distribution value is 200m
5 or less per square, and the reflectance of the paper surface is 75%.
It is possible to obtain paper with excellent optical reading characteristics as described above.

In addition, this paper has excellent barrier properties and release properties against carbon ink, so even if a back carbon printing section is provided on the back side of the paper, it will have a high contrast with the printed characters on the front of the form, and a uniform print. It is possible to provide a back carbon copy form that can ensure reflectance and has excellent optical readability.

Furthermore, since the copy form according to the present invention is obtained by printing carbon ink on the back side of paper with excellent optical properties, it can be manufactured at a lower cost than conventional carbonless copy forms. It is suitable for use as a mass-consumption optically readable copy form, and has advantages such as excellent copyability and no deterioration over time.

[Brief explanation of the drawing]

The drawing shows the back carbon printed part of the form according to the present invention at 380 degrees.
It is a graph showing the results of reflectance measured under a wavelength range of nm to 900 nm. Patent applicant Kobayashi Recording Paper Co., Ltd. Mishima Paper Co., Ltd. Agent Patent attorney Kazu 1) Seinori

Claims (1)

[Scope of Claims] 1. Paper-making filler added to pulp stock with a basis weight of 35~
75g/m^2 paper containing 5% to 25% of fillers with high oil absorption such as calcium carbonate, synthetic silica, etc., and light scattering coefficients such as titanium dioxide, urea resin, etc. Coating agent 0.5 in which 1% to 20% of a large filler is internally added and is a polymer material with film-forming properties such as starch, PVA, etc. on the wire side of the paper and has barrier properties against carbon ink. % to 3.5%, the coefficient of variation of the reflection optical density of the paper is 0.20 or less, and the dynamic permeability of the vehicle liquid for carbon ink is 5% after contact time.
An optical reading paper characterized in that the transfer amount is 11 ml/m^2 or less at 0 msec. 2. A copy form in which a plurality of forms are stacked in one set, and at least one form forming the copy form uses the paper according to claim 1, and carbon ink is printed on the back side of the paper. An optically readable back carbon copy form characterized by: 3. The reflectance of the paper surface side of the carbon ink printed part is 38
The optically readable back carbon copy form according to claim 2, wherein the optically readable back carbon copy form is adjusted to 75% or more in a wavelength range of 0 nm to 900 nm.