JP4767490B2 - High speed rotary ink jet recording postcard paper - Google Patents

Description

  The present invention relates to an improvement in printing density of an inkjet recording image, anti-transfer property of printing, water resistance / clearness and coating stability on a high-speed rotary ink jet pressure-bonded postcard paper using water-soluble ink. The pressure-sensitive postcard paper described here refers to a pressure-sensitive adhesive that does not exhibit tackiness or adhesiveness in a normal state, exhibits adhesiveness when pressed, and can be peeled off after pressure bonding (hereinafter referred to as pressure bonding). It is provided on the base paper.

  In recent years, with the revision of the postal code, confidential postcard papers with confidentiality have been put into practical use in which the paper on which necessary information is recorded is folded in two (referred to as a four-sided type) or tri-folded (referred to as a six-sided type). (See Patent Documents 1 and 2). Such a confidential postcard paper has no adhesiveness or adhesiveness under normal conditions, exhibits adhesiveness when pressed, and has a pressure sensitive adhesive on one or both sides of a support such as paper. It is a postcard paper that is provided with a layer that can be peeled after pressure bonding as an adhesive layer, and is pressure-bonded with the adhesive surfaces facing each other.

  In general, confidential postcards with confidentiality, in other words, confidential postcards, are printed with standard items (content explanation, notes, requests, etc.), and then personal confidential communication details (code number, (Member number, billing amount, deposit balance, etc.) are printed with a printer, etc., so that the confidential content cannot be seen from the outside, the printed adhesive surfaces are folded in half or folded in three and crimped with a dry sealer create. The recipient can see the contents of the confidential by peeling off the crimping part of the confidential postcard. Note that once the pressure-bonding portion of the confidential postcard is peeled off, the pressure-bonding portion has no adhesiveness, and therefore, the confidential postcard after peeling cannot be returned to the confidential postcard before peeling.

  Initially, the confidential postcard system was shipped by a relatively large printing company after printing, laser beam printer printing, and dry sealer pressure bonding. In recent years, an ink jet method using water-soluble ink has attracted attention, particularly a high-speed rotary ink jet method. This high-speed rotary ink jet system is a system in which direct printing is performed on a web by a serial nozzle continuous ink jet system in the same manner as a printing machine. According to such a high-speed rotary ink jet system, a large amount of information processing is possible, so that the running cost can be extremely reduced. As a typical water-soluble ink used in this high-speed rotary ink jet system, there is an ink manufactured by Cytex.

  Cytex's water-soluble ink has an ink solid content of 4 to 7% by mass. This water-soluble ink is mostly composed of a dye and water, and has a high dielectric constant and excellent thermal efficiency. In contrast, the water-soluble ink of a general inkjet printer has an ink solid content of 15% by mass or more. In order to prevent the ink cartridge head from drying, this water-soluble ink contains a relatively high amount of non-volatile high-boiling solvent in addition to the dye and water.

  The pressure-bonded postcard paper is required to have very little blocking, little deterioration in peel strength with time, and high printing durability when printing with general color inks. However, the high-speed rotary inkjet recording paper is required to have stricter characteristics than the pressure-bonded postcard paper. In other words, it is not sufficient to satisfy the above-mentioned characteristics required for the pressure-bonded postcard paper, and further, the water resistance and sharpness of the printed image are high, the ink absorbency is high, and the printed image is difficult to transfer after peeling. It is an important characteristic.

  Next, as a technique for improving the water resistance and sharpness of an ink-jet print image and the transferability of a print image after peeling, there are conventionally water resistance and ink fixing techniques. In that technology, the ink jet receiving layer contains a cationic polymer to charge the dye molecules in the ink in a charge, and van der Waals force acts between the ink and the cationic polymer to cause the dye molecules to move to the ink jet receiving layer. To settle.

As a cationic polymer that is an ink fixing agent, a proposal is made to contain a cationic compound having a quaternary ammonium group or a compound having a tertiary amino group in the adhesive composition, and the adhesive composition has a charge in a high pH range. Proposal for containing a cationic polymer whose charge is changed from zero to negative, and an adhesive composition having two types, a cationic polymer whose charge changes from zero to negative in a high pH range and a cationic polymer which holds a positive charge Proposals for containing metal salts have been made (see Patent Documents 3, 4, and 5). However, these proposals have insufficient water resistance and sharpness of printed images. In addition, proposals have been made to include polydimethylamine / epichlorohydrin and / or modified dimethylamine / epichlorohydrin polycondensate in the adhesive composition (see Patent Document 6). However, even with this proposal, the water resistance and sharpness of the printed image are insufficient. Furthermore, the proposal that the adhesive layer is an epihalohydrin-based cationic resin layer (see Patent Document 7), 5 to 100 parts by mass of either a polyamide / epichlorohydrin resin or a water-soluble modified polyamine resin with respect to 100 parts by mass of a natural rubber emulsion Proposal for inclusion (see Patent Document 8) has also been made, but gelation is caused by the addition of a cationic polymer during preparation of the coating solution for the adhesive layer, water resistance and sharpness are insufficient, or the amount of addition is increased. However, there is a problem that the peel strength is lowered.
JP 7-276858 A Japanese Patent Laid-Open No. 10-168798 JP-A-9-393 JP-A-9-157611 Japanese Patent Laid-Open No. 10-879 Japanese Patent Application Laid-Open No. 10-52985 Japanese Patent No. 3392649 JP-A-10-337980

  Accordingly, an object of the present invention is to provide a high-speed rotary ink jet recording pressure-sensitive postcard paper that has improved ink jet image density, printing transfer prevention, water resistance, sharpness, and coating stability, and is of practically high quality. There is to do.

Means for solving the problems to be solved by the present invention include adhesion based on a natural rubber derivative emulsion grafted with an unsaturated monomer, a fine particle filler, and a cationic compound that retains a positive charge in a high pH range. In a pressure-sensitive postcard paper for high speed rotary ink jet recording provided with a layer on a paper support, the cationic compound is an alkylamine / epichlorohydrin polycondensate having a number average molecular weight of 300 to 1000 or an amine / epichlorohydrin polycondensation having a number average molecular weight of 300 to 1000. are those, in combination said cationic compound is contained 5 to 60 parts by weight per 100 parts by weight the natural rubber derivative emulsion, further calcium salts in the cationic compound, a magnesium salt or zinc salt of one or more It is a pressure-sensitive postcard paper for high-speed rotary ink-jet recording.

  By adopting the above-described configuration, a remarkable effect is exhibited in improving the print density of the ink jet recorded image, the transfer preventing property of the print, the water resistance / clearness, and the coating stability.

The calcium salt, magnesium salt or zinc salt used in the present invention is its chloride, nitrate and acetate, specifically calcium chloride, magnesium chloride, zinc chloride, calcium nitrate, magnesium nitrate, zinc nitrate, acetic acid. Calcium, magnesium acetate and zinc acetate. Among these, calcium chloride, magnesium chloride, calcium nitrate, magnesium nitrate, calcium acetate and magnesium acetate are preferable, and calcium chloride is particularly preferable. Calcium salts used in the present invention, magnesium or zinc salt, 0.5 to 20 parts by weight with respect to the cationic compound 100 parts by weight for use in the present invention, that the can be used in combination particularly 5 to 10 parts by weight preferable. If the amount is less than 0.5 part by mass, the maximum effect cannot be obtained on the printed image density and the water resistance of the printed image. If the amount exceeds 20 parts by mass, the water resistance tends to be slightly lowered.

The cationic compound used in the present invention is an alkylamine / epichlorohydrin polycondensate having a number average molecular weight of 300 to 1000 or an amine / epichlorohydrin polycondensate having a number average molecular weight of 300 to 1000. Among them, methylamine / epichlorohydrin polycondensate, methylamine / epichlorohydrin polycondensate, ethylamine / epichlorohydrin polycondensate, propylamine / epichlorohydrin polycondensate, butylamine / epichlorohydrin polycondensate, dimethylamine / epichlorohydrin polycondensate, diethylamine / Epichlorohydrin polycondensate, dipropylamine / epichlorohydrin polycondensate, dibutylamine / epichlorohydrin polycondensate, trimethylamine / epichlorohydrin polycondensate, triethylamine / epichlorohydrin polycondensate, tripropylamine / epichlorohydrin polycondensate and tributylamine / epichlorohydrin polycondensate Examples include condensates. Of these, methylamine / epichlorohydrin polycondensate, dimethylamine / epichlorohydrin polycondensate and trimethylamine / epichlorohydrin polycondensate are particularly preferred. One or more of them are contained. When it is less than 300 or more than 1000, even if a calcium salt, a magnesium salt or a zinc salt is used in combination with the cationic compound, the printed image density and the water resistance of the printed image are inferior.

  The cationic compound used in the present invention is contained in an amount of 5 to 60 parts by mass, preferably 20 to 40 parts by mass with respect to 100 parts by mass of the solid content of the natural rubber derivative emulsion grafted with the unsaturated monomer. If it is less than 5 parts by mass, the water resistance is poor, and if it exceeds 60 parts by mass, the water resistance is poor. On the other hand, the pH of the solution of the cationic compound used in the present invention is usually 4-6. If the pH is too low, the mechanical stability and peel strength of the coating solution tend to decrease. When the cationic compound used in the present invention exceeds 60 parts by mass with respect to 100 parts by mass of the natural rubber derivative emulsion solid content, the pH becomes too low, and the mechanical stability and peel strength of the coating liquid are lowered. To do. Moreover, a pH adjuster can also be used for the solution of the cationic compound containing the calcium salt, magnesium salt, or zinc salt used by this invention, and sodium hydroxide and ammonia are illustrated as these.

The coating solution for the adhesive layer of the present invention comprises a natural rubber derivative emulsion grafted with an unsaturated monomer, a fine particle filler and a cationic compound as main components, and the cationic compound is used in combination with a calcium salt, a magnesium salt or a zinc salt. However, a water-soluble polymer or a hydrophobic emulsion can be contained as a binder for the fine particle filler, a natural rubber derivative can be contained as a deterioration preventing agent, and a binder or a deterioration preventing agent can also be contained. As the unsaturated monomer of the natural rubber derivative emulsion grafted with the unsaturated monomer used in the present invention, acrylonitrile, styrene, methyl methacrylate, vinylidene chloride, maleic anhydride, acrylamide, vinyl pyrrolidone, dimethyl acrylamide and glycidyl methacrylate are used. It can be illustrated. Among these, methyl methacrylate, styrene, acrylonitrile, and particularly methyl methacrylate are preferable. When methyl methacrylate, styrene, acrylonitrile, especially methyl methacrylate is used, side reactions such as homopolymer formation hardly occur, and the grafting reaction surely occurs. The unsaturated monomer necessary for causing the grafting reaction is preferably added in an amount of 10 to 40 parts by mass with respect to 100 parts by mass of the solid content of the natural rubber emulsion. If it is less than 10 parts by mass, no peak effect can be obtained in mechanical stability, and if it exceeds 40 parts by mass, the peel strength tends to decrease.

  As the fine particle filler used in the present invention, talc, kaolin, calcined kaolin, acidic clay, activated clay, amorphous synthetic silica, colloidal silica, colloidal alumina, zeolite, calcium carbonate, magnesium carbonate, titanium dioxide, zinc oxide, water Examples thereof include aluminum oxide, corn starch, potato starch and wheat starch. One or more of them are used. Examples of the dispersant for the fine particle filler used in the present invention include sodium pyrophosphate, sodium hexametaphosphate, sodium tripolyphosphate, sodium polyacrylate, sodium hydroxide, sodium silicate and ammonia. Among these, sodium hydroxide and ammonia are preferable. This is because sodium hydroxide and ammonia are particularly effective as pH adjusting agents for stabilizing the quality of the natural rubber emulsion.

  Water-soluble polymers and hydrophobic polymers that are binders for fine particle fillers include starch, casein, soy protein, gelatin, polyvinyl alcohol and their water-soluble polymers, styrene-butadiene copolymer latex, methyl Examples include hydrophobic polymers such as conjugated diene polymer latex such as methacrylate-butadiene copolymer and vinyl polymer latex such as ethylene-vinyl acetate copolymer. One or more of them are used.

  In order to prevent the natural rubber derivative emulsion grafted with the unsaturated monomer used in the present invention from being subjected to air oxidation / UV deterioration, an anti-aging agent can be contained. As their degradation inhibitors, amine-ketone series such as poly (2,2,4-trimethyl-1,2-hydroquinone), 6-ethoxy-1,2-dihydro-2,2,4-trimethylquinone; alkyl Aromatic secondary amines such as diphenylamine and N, N-di-2-naphthyl-p-phenylenediamine; benzimidazoles such as 2-mercaptobenzimidazole and zinc salt of 2-mercaptomethylbenzimidazole; 2,5 -Polyphenols such as ditertiary butyl hydroquinone can be exemplified. One or more of them can also be used.

  The coating solution for the adhesive layer in the present invention may contain an antistatic agent, a fluorescent brightening agent, a preservative, an antifoaming agent, a penetrating agent, and a coloring dye auxiliary.

  The adhesive layer coating solution of the present invention is applied to one or both sides of a paper support. The paper support used in the present invention is composed mainly of wood pulp and an embedded white pigment. Examples of the wood pulp include chemical pulps such as LBKP and NBKP; mechanical pulps such as GP, PGW, RMP, TMP, CTMP, and CGP; waste paper recycled pulp such as DIP. These pulps are adjusted for freeness by a beating machine in order to maintain papermaking suitability, coating suitability, printability, inkjet suitability, and the like. The pulp beating degree varies depending on the type of pulp, but is generally 150 to 500 ml [Canadian Standard Freeness (hereinafter referred to as CSF): JIS P-8121]. Furthermore, examples of the white pigment for filling include talc, calcined kaolin, calcium carbonate and titanium dioxide. These are used to maintain opacity and ink jet printing suitability. The amount is preferably 5 to 30 parts by mass, particularly 10 to 20 parts by mass with respect to 100 parts by mass of the pulp. In addition, various additives such as sizing agent, yield improver, cationizing agent and paper strength enhancer are mixed to make acidic, neutral and alkaline in paper machines such as long net paper machine, circular net paper machine and twin wire paper machine. A paper support is obtained.

As a method of providing the coating liquid for the adhesive layer of the present invention on one side of the paper support, blade coater, air knife coater, curtain coater, bar coater, gravure coater, roll coater, bill blade coater, gate roll coater, transfer roll A coating system such as a coater is used to provide an adhesive layer on one side of the paper support so that the coating amount is 1.5 to 10 g / m ² (dry mass solid content), preferably printing characteristics In order to further improve the quality, the surface of the adhesive layer is preferably processed with a smoothing device such as a super calender or soft calender so that the smoothness of the surface of the adhesive layer becomes 10 to 30 seconds in terms of Beck's smoothness. A crimped postcard paper can be obtained.

Or as a method of providing the coating liquid for the adhesive layer on both sides of the paper support, blade coater, air knife coater, curtain coater, bar coater, gravure coater, roll coater, bill blade coater, gate roll coater, transfer roll coater, etc. With this coating method, a double-sided adhesive layer is formed by coating and drying on one side of the paper support and then on the other side so that the coating amount on one side is 1.5 to 10 g / m ² (dry mass solid content). A tri-fold rotary ink jet is preferably provided by a smoothing device such as a super calender or a soft calender, as described above, preferably so that the smoothness of both sides of the adhesive layer is 10 to 30 seconds as Beck smoothness. Obtain pressure-sensitive postcard paper for recording. When the Beck smoothness is less than 10 seconds, the sharpness of the printed image is slightly inferior to the maximum effect, and when it exceeds 30 seconds, the peel strength tends to decrease.

  The preferred embodiments of the present invention and the excellent effects thereof will be specifically described below with reference to examples. In the following, all parts are parts by mass, and all% are% by mass.

[Preparation of crimped postcard paper for bi-fold high-speed inkjet recording]
While stirring 267 parts of 15% amorphous synthetic silica dispersion (40 parts by mass solids), 381 parts of 21% wheat starch dispersion (80 parts by mass solids) and 50% natural grafted 25% of methyl methacrylate 200 parts of rubber derivative emulsion (mass solid content 100 parts), 5% polyvinyl alcohol aqueous solution 200 parts (mass solid content 10 parts), 50% ethylene-vinyl acetate copolymer latex 20 parts (mass solid content 10 parts) gradually To 1068 parts of the mother liquor prepared by addition, 10 parts of a 50% aqueous solution of dimethylamine / epichlorohydrin polycondensate having a number average molecular weight of 700 containing 10% of calcium chloride, which is a cationic compound, is stirred (5 parts by mass solid content). The mixture was added while adjusting the concentration to 22% with diluting water, and then filtered through a 150-mesh wire mesh to obtain an adhesive layer coating solution.

Next, this adhesive layer coating solution was applied to a high-quality paper of 138 g / m ^{2 with} an air knife coater and dried so that the coating amount was 5.5 g / m ² (dry mass solid content). After that, a Beck type smoothness was processed with a soft calender so as to be 15 to 20 seconds to obtain a two-fold high speed rotary ink jet recording pressure-bonded postcard paper.

[Preparation of crimped postcard paper for bi-fold high-speed inkjet recording]
Except for increasing 10 parts (mass solid content 5 parts) of 50% aqueous solution of dimethylamine / epichlorohydrin polycondensate having a number average molecular weight of 700 containing 10% calcium chloride of Example 1 to 80 parts (mass solid content 40 parts). In the same manner, a crimped postcard paper for two-fold high-speed rotary inkjet recording was obtained.

[Preparation of crimped postcard paper for bi-fold high-speed inkjet recording]
Except for increasing 10 parts (mass solid content 5 parts) of a 50% aqueous solution of dimethylamine / epichlorohydrin polycondensate having a number average molecular weight of 700 containing 10% calcium chloride of Example 1 to 120 parts (mass solid content 60 parts). In the same manner, a crimped postcard paper for two-fold high-speed rotary inkjet recording was obtained.

[Preparation of crimped postcard paper for bi-fold high-speed inkjet recording]
A 50% aqueous dimethylamine / epichlorohydrin polycondensate having a number average molecular weight of 700 containing 10% calcium chloride in Example 1 and a 50% aqueous dimethylamine / epichlorohydrin polycondensate having a number average molecular weight of 1000 containing 10% magnesium chloride 80. A crimped postcard paper for bi-fold high-speed rotary ink jet recording was obtained in the same manner except that it was replaced with a part (mass solid content 40 parts).

[Preparation of crimped postcard paper for bi-fold high-speed inkjet recording]
A 50% aqueous solution of dimethylamine / epichlorohydrin polycondensate having a number average molecular weight of 700 containing 10% of calcium chloride in Example 1 and a 50% aqueous solution of dimethylamine / epichlorohydrin having a number average molecular weight of 1000 containing 10% of zinc chloride are 80%. A crimped postcard paper for bi-fold high-speed rotary ink jet recording was obtained in the same manner except that it was replaced with a part (mass solid content 40 parts).

[Preparation of crimped postcard paper for bi-fold high-speed inkjet recording]
80 parts of a 50% aqueous solution of dimethylamine / epichlorohydrin polycondensate having a number average molecular weight of 700 containing 10% of calcium chloride in Example 1 and 80 parts of an aqueous solution of amine / epichlorohydrin having a number average molecular weight of 1000 containing 10% of calcium chloride. A bi-fold high speed rotary ink jet recording pressure-bonded postcard paper was obtained in the same manner except that the mass solid content was 40 parts.

[Preparation of crimped postcard paper for bi-fold high-speed inkjet recording]
A 50% aqueous solution of dimethylamine / epichlorohydrin polycondensate having a number average molecular weight of 700 containing 10% of calcium chloride of Example 1 and 60 parts of an aqueous solution of amine / epichlorohydrin having a number average molecular weight of 700 containing 10% of calcium chloride is 60 parts. (Mass solid content 30 parts) and the same method except for mixing and replacing with 20 parts (mass solid content 10 parts) of 50% aqueous solution of trimethylamine / epichlorohydrin polycondensate having a number average molecular weight of 700 containing 10% calcium chloride A crimped postcard paper for bi-fold high-speed inkjet recording was obtained.

[Preparation of crimped postcard paper for bi-fold high-speed inkjet recording]
A 50% aqueous solution of a dimethylamine / epichlorohydrin polycondensate having a number average molecular weight of 700 containing 10% of calcium chloride in Example 1 and a 50% aqueous solution of dimethylamine / epichlorohydrin having a number average molecular weight of 700 containing 10% of calcium chloride. The same method except that the mixture was replaced with 10 parts (mass solid content 5 parts) of a 50% aqueous solution of a trimethylamine / epichlorohydrin polycondensate having a number average molecular weight of 700 containing 10 parts of calcium chloride (mass solid content 35 parts). In this way, a crimped postcard paper for bi-fold high-speed rotary inkjet recording was obtained.

[Preparation of crimped postcard paper for bi-fold high-speed inkjet recording]
10 parts of a 50% aqueous solution of dimethylamine / epichlorohydrin polycondensate having a number average molecular weight of 700 containing 10% of calcium chloride and 10 parts of an aqueous solution of amine / epichlorohydrin having a number average molecular weight of 700 containing 10% of calcium chloride. Number average molecular weight containing 60 parts of 50% aqueous solution of dimethylamine / epichlorohydrin polycondensate having a number average molecular weight of 700 (mass solid content of 5 parts) and calcium chloride of 10% and calcium chloride of 10%. A crimped postcard paper for bi-fold high speed rotary ink jet recording was obtained in the same manner except that it was mixed and replaced with 10 parts of a 50% aqueous solution of trimethylamine / epichlorohydrin polycondensate of 700 (mass solid content 5 parts).

[Preparation of crimped postcard paper for tri-fold high-speed rotary inkjet recording]
The coating amount of the adhesive layer coating solution of Example 2 is 5.5 g / m ² (dry mass solid content) on each side of 112 g / m ² high-quality paper with an air knife coater on the other side. After coating and drying as described above, an adhesive layer was provided, and then processed with a soft calender so that the Beck smoothness was 15 to 20 seconds to obtain a crimped postcard paper for tri-fold high-speed inkjet recording.

[Preparation of crimped postcard paper for tri-fold high-speed rotary inkjet recording]
The coating amount of the adhesive layer coating solution of Example 4 was set to 5.5 g / m ² (dry mass solid content) on each side of 112 g / m ² high-quality paper using an air knife coater on the other side. After coating and drying as described above, an adhesive layer was provided, and then processed with a soft calender so that the Beck smoothness was 15 to 20 seconds to obtain a crimped postcard paper for tri-fold high-speed inkjet recording.

[Preparation of crimped postcard paper for tri-fold high-speed rotary inkjet recording]
The coating amount for the adhesive layer of Example 8 is 112 g / m ² on one side of high-quality paper, and then the other side is coated with an air knife coater to give 5.5 g / m ² (dry mass solid content). After coating and drying as described above, an adhesive layer was provided, and then processed with a soft calender so that the Beck smoothness was 15 to 20 seconds to obtain a crimped postcard paper for tri-fold high-speed inkjet recording.

(Comparative Example 1)
[Preparation of crimped postcard paper for bi-fold high-speed inkjet recording]
80 parts of a 50% aqueous solution of polycondensate of dimethylamine and epichlorohydrin having a number average molecular weight of 700 containing 10% of calcium chloride which is the cationic compound of Example 2 (40 parts by mass solid content) was added to a 40% aqueous solution of N-hydroxypropylpolyethyleneimine. A bi-fold high speed rotary ink jet recording pressure-sensitive postcard paper was obtained in the same manner except that it was replaced with 100 parts (mass solid content 40 parts).

(Comparative Example 2)
[Preparation of crimped postcard paper for bi-fold high-speed inkjet recording]
The same procedure was followed except that 80 parts of a 50% aqueous solution of polycondensate of dimethylamine / epichlorohydrin having a number average molecular weight of 700 containing 10% of calcium chloride, which is the cationic compound of Example 2, was removed. A crimped postcard paper for fold high-speed ink jet recording was obtained.

(Comparative Example 3)
[Preparation of crimped postcard paper for bi-fold high-speed inkjet recording]
A dimethylamine / epichlorohydrin polycondensate having a number average molecular weight of 700 containing 10% of barium chloride and a 50% aqueous solution of polydimethylcondensine / chlorochlorohydrin polycondensate having a number average molecular weight of 700 containing 10% of calcium chloride, which is the cationic compound of Example 2. In the same manner except that the same amount was replaced with a 50% aqueous solution, a folded postcard paper for high speed rotary ink jet recording was obtained in the same manner.

(Comparative Example 4)
[Preparation of crimped postcard paper for bi-fold high-speed inkjet recording]
A dimethylamine / epichlorohydrin polycondensate 50 having a number average molecular weight of 700 and containing no metal salt of a 50% aqueous solution of polydimethylcondensine polychlorocondensate having a number average molecular weight of 700 containing 10% of calcium chloride, which is the cationic compound of Example 2. A crimped postcard paper for bi-fold high speed rotary ink jet recording was obtained in the same manner except that the same amount was replaced with a% aqueous solution.

  The high speed rotary bi-fold and tri-fold ink jet recording postcard papers obtained in Examples 1 to 12 and Comparative Examples 1 to 4 were measured and evaluated by the following methods.

Evaluation Method << Cationic Compound Aqueous Charge >>
An aqueous solution obtained by diluting a single cationic compound or a mixture of a plurality of cationic compounds used in each example and each comparative example with distilled water to a concentration of 10% was adjusted to pH 10 (pH meter F-21 with 1 N sodium hydroxide). : Horiba Seisakusho), and the streaming potential (particle charge meter PCD-03: MUTEK) mV value was measured. The pH of the 10% aqueous solution of N-hydroxypropylpolyethyleneimine was 11.30.
《Flowability of coating liquid》
○ mark: Newtonian flow and excellent coating stability.
X mark: It is a thixotropic flow and lacks coating stability.
<Print density>
Cytex 1040 BLACK ink was injected into the ink tank of an ink jet printer (BJC420J manufactured by Canon Inc.) with a syringe, and then the test layer was printed on the adhesive layer surface, and the print density after 1 hour was measured with a Macbeth densitometer. The larger the value, the higher the concentration.

《Water resistance and sharpness of inkjet printed images》
After injection of Cytex 1040 BLACK ink, Cytex 1068BLUE ink, or Cytex 1076RED ink into the ink tank of an ink jet printer (BJC420J manufactured by Canon Inc.), a test print pattern (characters, lines, solid) is printed on the adhesive layer surface. After 2 minutes, water was dropped, and after natural drying, the degree of bleeding of the printed image and the image sharpness were visually determined.
○ mark: Very excellent with no bleeding.
Δ: Slight bleeding is observed but there is no practical problem.
X mark: Bleeding occurs and is not practical.

<Transferability of printed image after peeling>
* Folded crimped postcard paper Cytex 1040 and BLACK ink are injected into the ink tank of an inkjet printer (BJC420J manufactured by Canon Inc.) in a room at 23 ° C and 50% RH, and then a test print pattern (characters, lines, solid) Is printed on the left half of the adhesive layer surface of the pressure-bonded postcard paper having a width of 204 mm and a length of 152.4 mm, and after 20 minutes of printing, the printed adhesive layer surface is on the inside and the width is 102 mm and the length is 152.4 mm. The ink transfer density was set to a pressure scale 15 of a dry sealer and pressure-bonded, peeled by hand, and transferred to the right half surface of the adhesive layer surface to visually determine.
○ mark: There is no ink transfer, and it is excellent.
Δ: Ink is transferred slightly, but there is no practical problem.
X mark: Ink is transferred and is not practical.

* Tri-fold pressure-bonded postcard paper After injecting Cytex 1040 and BLACK ink into the ink tank of an inkjet printer (BJC420J manufactured by Canon Inc.) in a room at 23 ° C and 50% RH, a test print pattern (characters, lines, solid) Is printed on the left 1/3 side of the adhesive layer surface and the right 1/3 side of the other adhesive layer surface on which the confidential information of the pressure-bonded postcard paper having a width of 306 mm and a length of 152.4 mm is printed. The adhesive layer surface is inwardly folded in an N shape so that the width is 102 mm × length is 152.4 mm, and is set on the pressure scale 30 of the dry sealer and crimped. The ink transfer density transferred to the right half was visually judged.
○ mark: There is no ink transfer, and it is excellent.
Δ: Ink is transferred slightly, but there is no practical problem.
X mark: Ink is transferred and is not practical.

The above measurement / evaluation results are summarized in Tables 1 and 2. Table 2 shows the overall evaluation.
○: Excellent in suitability for crimping postcards and high-speed rotary ink jet printing.
Δ: The suitability for pressure-bonding postcards and the suitability for high-speed rotary ink-jet printing are at a level with no practical problems.
X mark: There is a problem in important quality and lack of practicality in suitability for pressure-bonding postcards and suitability for high-speed rotary ink jet printing.

Claims (1)

In a pressure-sensitive postcard for high speed rotary ink jet recording, an adhesive layer containing a natural rubber derivative emulsion grafted with an unsaturated monomer, a fine particle filler, and a cationic compound having a positive charge at a pH of 10 or more is provided on a paper support. The cationic compound is an alkylamine / epichlorohydrin polycondensate having a number average molecular weight of 300 to 1000 or an amine / epichlorohydrin polycondensate having a number average molecular weight of 300 to 1000, and the cationic compound has a solid content of 100 mass of the natural rubber derivative emulsion. 5-60 parts by weight is contained, a high speed rotary ink jet recording crimp postcard paper, characterized in that the combination further calcium salt, magnesium salt or zinc salt of one or more the said cationic compound relative parts.