JP2000265394A - Ocr paper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide OCR paper having excellent ink setting property and image waterproof in a high-speed rotary ink jet system while retaining a conventional aptitude for OCR paper. SOLUTION: This OCR paper is produced by applying an alkylamin/ epihalohydrin polycondensation product and/or an alkylamine/ammonia/ epihalohydrin polycondensation product each having <=20,000 molecular weight, preferably <=10,000 molecular weight to a substrate body in an amount of 1.0-2.0 g/m2 per both sides and by setting a 10-second cobb size according to JIS P8,140 to 10-50 g/m2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an OCR sheet, and more particularly to an OCR sheet which can be used in an ink jet recording system for recording using a water-soluble ink. More specifically, the present invention relates to an OCR sheet having good ink setting properties and image water resistance in a high-speed rotary inkjet printing system without impairing the suitability as a conventional OCR sheet.

[0002]

2. Description of the Related Art In recent years, OCR paper has been applied to a wide range of fields with the progress of an OCR system capable of optically reading characters and figures by printing or handwriting and inputting it to a computer. Normally, OCR paper reads characters, figures, and the like by reflection on specific light, so that there are no defects (stains, wrinkles, pinholes) affecting the light reflection characteristics, no curl, and a moderate degree of curl. It has rigidity and a coefficient of friction, has good transportability in printing machines and optical readers, has moderate smoothness and surface strength, and has good dimensional stability. In addition, OCR paper having satisfactory suitability for offset printing and offset printing was provided.

On the other hand, as a recording method, ink-jet recording using a water-soluble ink has made remarkable progress in recent years and is rapidly spreading. The ink jet recording system records fine images and characters by flying small droplets of ink by various operating principles and attaching them to a recording sheet such as paper. It is easy to use, has great flexibility in recording patterns, and does not require development-fixing, and is rapidly spreading in various applications as a recording device for various figures including Chinese characters and color images. Further, it is possible to obtain an image formed by the multi-color ink jet system, which is comparable to multi-color printing by the plate making system or printing by the color photographic system. In applications where the number of copies required is small,
Since it is cheaper than photographic technology, it is being widely applied to the field of full-color image recording.

[0004] More recently, a high-speed ink-jet printing system of a rotary printing type has also been developed, and is also being used for on-demand printing such as address printing, customer information printing, numbering printing, and bar code printing. There is a need for usable OCR paper.

However, when the conventional OCR paper is used for such a purpose, rubbing stains may occur after printing due to poor ink setting property for water-based ink,
Even after the ink has completely dried, there has been a problem that the ink dye flows out when the humidity is high or when the printing portion is exposed to water for some reason.

That is, as the OCR paper, a conventional OCR paper is used.
Without impairing the suitability as CR paper, in a rotary type high-speed inkjet printing system,
It is required that the ink dyeing property is sufficient even at a printing speed of 50 m / min or more, and that the ink dye does not flow out (image water resistance) even when the humidity is high or the printing area is exposed to water for some reason. Is done.

In order to improve ink setability and image water resistance in ink jet recording, Japanese Patent Application Laid-Open No. 9-2020
No. 42 and JP-A-10-166713 disclose examples of a plain paper type ink jet recording sheet in which a cationic resin is adhered to control the size to a low size. When this method is used for OCR paper, the ink setting property and image water resistance in ink jet recording are good, but due to its high ink absorbency (low sizing property), curl due to moisture absorption, change in friction coefficient, A decrease in surface strength, poor dimensional stability, etc. occur, causing troubles such as offset printing and transportability with an optical reader.

[0008]

As described above, an OCR paper satisfying the ink setting property and image water resistance has been obtained in a rotary type high-speed ink jet printing system without impairing the suitability as a conventional OCR paper. There is no present.

An object of the present invention is to satisfy the following problems in OCR paper. 1. Satisfies the suitability of conventional OCR paper (no defects that affect the light reflection characteristics, good transportability in printing machines and optical readers, good writing characteristics and offset printing suitability). 2. To have good ink setting properties and image water resistance in a rotary type high-speed inkjet printing system.

[0010]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies in view of the above, and as a result, have satisfied the problem by attaching a specific cationic resin to a support and controlling the size to a specific range. To invent OCR paper.

That is, in the ink jet recording sheet of the present invention, an alkylamine / epihalohydrin polycondensate having a molecular weight of 20,000 or less and / or an alkylamine / ammonia / epihalohydrin polycondensate having a molecular weight of 20,000 or less is used on the support in an amount of 1.0 to 2. 0 g / m ² and J
10-second cobb size according to IS P8140 is 1
It is characterized by being 0 to 50 g / m ² .

Further, preferably, the molecular weight of the alkylamine / epihalohydrin polycondensate and / or the alkylamine / ammonia / epihalohydrin polycondensate is 1
0000 or less.

Furthermore, the OCR paper of the present invention is characterized in that it is used for a high-speed rotary ink jet system.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the OCR paper of the present invention will be described in detail.

In order to improve the water fastness of an image of a water-soluble ink containing a direct dye or an acid dye used in an ink jet recording system, fixing of the dye by reaction of an anionic part of the dye with a cationic substance and water-proofing treatment are carried out. Is self-evident. Normally, in an ink jet recording sheet, as a method for imparting image water resistance,
A method of attaching a cationic resin as shown below is employed.

The generally used cationic resin is a monomer, oligomer or polymer of a primary to tertiary amine or quaternary ammonium salt which dissociates when dissolved in water to exhibit a cationic property, and is preferably an oligomer. Or a polymer. In particular, in the present invention, an alkylamine / epihalohydrin polycondensate and / or an alkylamine / ammonia / epihalohydrin polycondensate is used.

The molecular weight of the cationic resin used in the present invention is 20,000 or less, preferably 10,000 or less. When the molecular weight is larger than 20,000, sufficient image water resistance cannot be obtained. The reason for this is not clear, but the inks used in rotary high-speed inkjet printing systems are:
It is an anionic dye having a relatively large molecule, and the fixing mechanism with the cationic resin is presumed to be that a fixing agent adheres around the dye molecule. Therefore, in order to fix the dye efficiently, a lower molecular weight is considered preferable. .

The dry adhesion amount of the cationic resin is from 1.0 to
A range of 2.0 g / m ² is preferable, and if it is less than this range, sufficient image water resistance cannot be obtained, and it may be more than this range, but no further effect of improving image water resistance can be obtained, It is not preferable in terms of cost and apparently far from plain paper.

As a method for attaching the cationic resin, it is also possible to apply the coating by various coating machines such as a blade press, a rod coater, an air knife coater, and a curtain coater in addition to a size press, a gate roll coater, and a film transfer coater. However, from the viewpoint of cost, it is desirable that the adhesive be adhered by a size press, a gate roll coater, a film transfer coater, or the like provided in a paper machine and finished on-machine.

The size of the OCR paper of the present invention is determined according to JIS.
10-second cobb size according to P8140 is 10
It is 50 g / m ² . The reason for specifying the cobb size is
When the value is large, that is, when the water absorption is good, the ink setting property and the image water resistance in the ink jet recording are good, but a trouble occurs in the offset printing and the optical reader. Troubles in offset printing are blank pilling and background dirt.The water absorption is so good that it causes a decrease in the strength of the paper surface. The plate is considered to be dirty because it is robbed. If you increase the supply of dampening water to avoid contamination,
As a result, the balance between the printing ink and the water is lost, and ink deposition failure or the like is caused. Also, in an optical reader, curling due to moisture absorption of a sheet, a change in a coefficient of friction, and the like occur to cause trouble in transportability.

The 10 second cobb size is 10 g / m ^2.
In the case where the water absorption is smaller, that is, when the water absorption is poor, 150 m / m
In inkjet recording performed at a printing speed of at least in, the printed ink is not completely dried by the auxiliary drying device, but is transferred to a metal roll provided immediately after the auxiliary drying device, and the transferred ink is re-transferred to paper. And cause dirt.

The control of the 10-second cobb size is as follows:
Internal sizing agents such as rosin sizing agents, alkenyl succinic anhydrides, alkyl ketene dimers, and petroleum resin sizing agents may be used alone, but surface sizing agents can be used in combination with a cationic resin using a size press or gate roll device. Can also be used.

Examples of the surface sizing agent used in combination with the cationic resin include styrene / acrylic acid polymers, styrene /
Surface sizing agents such as methacrylic acid-based polymers, acrylonitrile / vinyl formal / acrylate ester copolymers, styrene / maleic acid-based copolymers, AKD-based, and rosin-based can be used. For this, a cationic surface sizing agent is preferred.

Further, a binder is used if necessary together with the cationic resin and the surface sizing agent, and oxidized starch,
Use of phosphate esterified starch, self-modified starch, cationized starch or various modified starches, polyethylene oxide, polyacrylamide, sodium polyacrylate, sodium alginate, hydroxymethylcellulose, methylcellulose, polyvinylalcohol or derivatives thereof alone or in combination can do.

As the support of the OCR paper of the present invention, a paper-like material such as a paper mainly composed of wood fibers or a non-woven fabric mainly composed of wood fibers or synthetic fibers can be used. , NBKP, LBKP, NBS
In addition to P, LBSP, GP, TMP, etc., used paper pulp is used, and used alone or in combination as needed.

The raw materials for the waste paper pulp referred to in the present invention include, for example, top white, ruled white, cream white, card, and the like shown in the waste paper standard quality standard table of the Waste Paper Recycling Promotion Center.
Special white, medium white, imitation, fair white, Kent, white art, special top cut,
Another example is newspaper, magazine, etc. Further specific examples include uncoated computer paper, which is information-related paper,
Printer paper such as thermal paper, pressure-sensitive paper, and OA waste paper such as PPC paper, coated paper such as art paper, coated paper, lightly coated paper, matte paper, or fine paper, color fine, notebook,
Used paper such as stationery, wrapping paper, fancy paper, medium paper, newsprint, paper change, super-hanging paper, imitation paper, pure white roll paper, uncoated paper such as milk carton, etc.
Chemical pulp paper, high-yield pulp-containing paper and the like are used, but are not particularly limited regardless of printing, copying, printing, and non-printing.

As the internal filler used for the support, conventionally known pigments are used as white pigments, and they can be used alone or in combination. Examples thereof include light calcium carbonate, heavy calcium carbonate, kaolin, clay, talc, and the like. Calcium sulfate, barium sulfate, titanium dioxide, zinc oxide, zinc sulfide, zinc carbonate, satin white, aluminum silicate, diatomaceous earth, calcium silicate, magnesium silicate, synthetic silica, aluminum hydroxide, alumina, lithopone, zeolite, magnesium carbonate, water White inorganic pigments such as magnesium oxide, styrene-based plastic pigments,
Organic pigments such as acrylic plastic pigments, polyethylene, microcapsules, urea resins, and melamine resins.

In the present invention, other additives such as a pigment dispersant, a thickener, a flow improver, an antifoaming agent, a foam inhibitor, a releasing agent, a foaming agent, a penetrant, Coloring dyes, coloring pigments, fluorescent whitening agents, ultraviolet absorbers, antioxidants, preservatives, anti-binders, water-proofing agents, wet paper strength enhancers, dry paper strength enhancers, etc. to achieve the desired effects of the present invention. It can also be appropriately compounded within a range that does not impair.

In the paper making method of the present invention, a paper machine known in the papermaking industry, such as a fourdrinier paper machine, a twin wire paper machine, a combination paper machine, a round mesh paper machine, or a Yankee paper machine, can be used as appropriate.

The OCR paper of the present invention exhibits an excellent effect in a rotary type high-speed ink-jet printing system, but can be used in other ink-jet systems such as a commercially available ink-jet printer without any limitation.

[0031]

The present invention will be described below with reference to examples of the present invention, but the present invention is not limited to these examples. Further, “parts” and “%” shown in Examples are
Unless indicated otherwise, parts by weight and% by weight are indicated.

<Preparation of Support 1> Freeness 550 mlcs
80 parts of LBKP of f, NBK of freeness 500mlcsf
7 parts of light calcium carbonate (trade name: TP-121, manufactured by Okutama Industry Co., Ltd.), 0.5 part of amphoteric starch (trade name: Cato3210, manufactured by Oji National Co., Ltd.), and paper strength Agent (trade name: WS
-570, manufactured by PMC Japan, 0.08 part, alkyl ketene dimer type sizing agent (trade name: Size Pine K90)
3, manufactured by Arakawa Chemical Co., Ltd.), and papermaking was performed using a fourdrinier paper machine to prepare a support 1 having a basis weight of 80 g / m ² .

<Preparation of Support 2> A support 2 was prepared in the same manner as in the preparation of the support 1, except that the amount of the alkyl ketene dimer type sizing agent of the support 1 was changed to 0.10 part.

<Preparation of Support 3> A support 3 was prepared in the same manner as in the preparation of the support 1, except that the amount of the alkyl ketene dimer type sizing agent of the support 1 was changed to 0.02 part.

Example 1 Polycondensate of dimethylamine / ammonia / epichlorohydrin (trade name: Jetfix 31A, molecular weight: 45) was used as a cationic resin on the support 1 prepared as described above.
00, manufactured by Satoda Kako Co., Ltd.) in a dry adhesion amount of 1.5 g / m ² , oxidized starch (trade name: MS # 3800, manufactured by Nippon Shokuhin Kako Co., Ltd.)
Was applied using an on-machine size press device so that the dry adhesion amount was 3.0 g / m ^2, and machine calendering was performed to produce OCR paper of Example 1.

Example 2 The cationic resin of Example 1 was replaced with dimethylamine / epichlorohydrin polycondensate (trade name: Jetfix 36).
N, molecular weight 3100, manufactured by Satoda Kako Co., Ltd.), and an OCR paper of Example 2 was produced in the same manner as in Example 1.

Example 3 The cationic resin of Example 1 was replaced with dimethylamine / epichlorohydrin polycondensate (trade name: AGEFLOC B50).
OCR paper of Example 3 was produced in the same manner as in Example 1 except that LV, molecular weight 15000, manufactured by JPN Chemical Company).

Example 4 The procedure of Example 1 was repeated except that the cationic resin used in Example 1 was dimethylamine / ammonia / epichlorohydrin polycondensate (trade name: Papiogen P-105, molecular weight: 20,000, manufactured by SENKA). Thus, the OCR paper of Example 4 was produced.

Example 5 The dry adhesion amount of the cationic resin of Example 1 was 1.0 g / m ^2.
In the same manner as in Example 1 except that
An R sheet was prepared.

Example 6 An OCR sheet of Example 6 was produced in the same manner as in Example 1 except that the support of Example 1 was changed to Support 2.

Example 7 The OCR of Example 7 was carried out in the same manner as in Example 1 except that the support of Example 1 was used as the support ² and the dry adhesion amount of the cationic resin was changed to 2.0 g / m ^2. Paper was made.

Example 8 An OCR sheet of Example 8 was produced in the same manner as in Example 2 except that the support of Example 2 was changed to Support 2.

Comparative Example 1 The cationic resin of Example 1 was replaced with dimethylamine / epichlorohydrin polycondensate (trade name: AGEFLOC B5).
OCR paper of Comparative Example 1 was prepared in the same manner as in Example 1, except that the molecular weight was 0, the molecular weight was 30,000, and was manufactured by JPN Chemical Company.

Comparative Example 2 The procedure of Example 1 was repeated, except that the cationic resin used in Example 1 was dimethylamine / ammonia / epichlorohydrin polycondensate (trade name: Papiogen P-104, molecular weight: 40,000, manufactured by SENKA). Thus, an OCR paper of Comparative Example 2 was produced.

Comparative Example 3 The OCR of Comparative Example 3 was carried out in the same manner as in Example 1 except that the support of Example 1 was used as the support ² and the dry adhesion amount of the cationic resin was changed to 0.8 g / m ^2. Paper was made.

Comparative Example 4 An OCR paper of Comparative Example 4 was produced in the same manner as in Example 1 except that the support of Example 1 was changed to Support 3.

Comparative Example 5 The procedure of Example 7 was repeated except that a cationic surface sizing agent (trade name: Vasoplast 265D, manufactured by BASF) was added to the size press solution of Example 7 so that the dry adhesion amount was 0.2 g / m ^2. In the same manner as in Example 7, an OCR paper of Comparative Example 5 was produced.

Comparative Example 6 A general OCR paper (Mitsubishi OCR paper) was used as it was as an OCR paper of Comparative Example 6.

For the OCR papers of Examples 1 to 8 and Comparative Examples 1 to 6 produced as described above, a printing speed: 150 m / min, an ink used: T & K TOKA UV Best Cure Ink and gold red using an offset form rotary press made by Miyakoshi. , UV irradiation amount: ruled lines, halftone dots,
The evaluation image mainly composed of characters was printed. At the time of printing, conditions were set using ordinary OCR paper, and after confirming that printing was possible without any problem, printing was performed at 6000 m on the sheet.

Next, the paper on which offset printing has been performed is subjected to a printing speed of 50, 10 or
Each speed of 0, 150, 200 m / min, ink used:
Scitex 1007 black ink, auxiliary dryer: high frequency dryer manufactured by Fuji Denki Koki (transmission frequency 27.12 MHz,
(Output 7.5 kW) The evaluation image was printed under the condition of two passes.

Further, after the above-mentioned paper is cut into an appropriate size, an NEC OCR reader N-6370U is used.
A transportability test was performed on 1,000 sheets with X, and the results were evaluated by the evaluation methods described below. The results are shown in Table 1.

<Appropriateness of Offset Printing> Visual determination was made on the state of blank piling after offset printing and the state of background stain on blank white paper. A shows good characteristics, B shows good results in practically acceptable range, C shows practical problems, and D shows poor characteristics.

<Ink Setability> Ink-jet recording was performed by changing the printing speed, and the ink was recorded at the upper limit speed at which no transfer stain of the ink occurred. Practically, 150 m / min or more is required.

<Image Water Resistance> The sheet after ink jet recording was immersed in tap water for 30 seconds, and excess water was absorbed with filter paper and air-dried. Thereafter, the degree of bleeding of the recorded image was visually evaluated. As evaluation criteria, A shows good characteristics, B shows good results in practically acceptable range, C shows practical problems, and D shows poor characteristics.

<OCR Conveying Property> A sheet which passed 1000 sheets and all of which passed without any problem was regarded as "good", and a sheet in which at least one sheet passing trouble occurred was regarded as "poor".

[0056]

[Table 1]

As is evident from the results of Examples 1 to 8 in Table 1 above, the alkylamine / epihalohydrin polycondensate and / or the alkylamine / ammonia / epihalohydrin having a molecular weight of 20,000 or less, preferably 10,000 or less on the support. 1.0 ~
2.0 g / m ² and 10 second cobb size
50 g / m ² OCR paper is suitable for offset printing,
The OCR transportability is good, and the ink setting property and image water resistance in ink jet recording are also good.

As is apparent from Comparative Examples 1 to 3, the alkylamine-epihalohydrin polycondensate and / or the alkylamine-ammonia-epihalohydrin polycondensate have a molecular weight of more than 20,000 or an adhesion amount of 1.0 g. Those with less than / m ² have poor water resistance of the image. Further, as is apparent from Comparative Examples 4 and 5, those having a 10-second cobb size degree of more than 50 g / m ² have poor offset printing suitability and OCR transportability, and those having a cob size degree of less than 10 g / m ² have poor ink setting properties. It can be seen that it is. The general OCR paper of Comparative Example 6 has poor ink setting properties and poor image water resistance.

[0059]

According to the OCR paper of the present invention, an alkylamine / epihalohydrin polycondensate and / or an alkylamine / ammonia / epihalohydrin polycondensate having a molecular weight of 20,000 or less, preferably 10,000 or less, is added to the support on each side. 0 to 2.0 g / m ² and a 10-second cobb size according to JIS P8140
By adjusting the amount to 0 to 50 g / m ² , good ink setting properties and image water resistance could be obtained in a rotary type high-speed inkjet printing system without impairing the suitability as conventional OCR paper.

Claims (3)

[Claims] An alkylamine / epihalohydrin polycondensate having a molecular weight of 20,000 or less and / or an alkylamine / ammonia / epihalohydrin polycondensate having a molecular weight of 20,000 or less is attached to a support in an amount of 1.0 to 2.0 g / m ² on both surfaces. OCR characterized in that the 10-second cobb size according to JISP8140 is 10 to 50 g / m ^2.
Paper. 2. The OCR paper according to claim 1, wherein the molecular weight of the alkylamine / epihalohydrin polycondensate and / or the alkylamine / ammonia / epihalohydrin polycondensate is 10,000 or less. 3. The OCR paper according to claim 1, wherein the OCR paper is used for a high-speed rotary inkjet system.