JP2920913B2 - Coating composition for pressure-sensitive recording paper - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a pressure-sensitive recording paper coating composition having excellent color developing properties,
The present invention relates to a method for producing a pressure-sensitive recording paper using the composition, and a pressure-sensitive recording paper coated with the composition on the surface.

<Prior Art> Pressure-sensitive recording paper is used in large quantities for various slips and the like. In general, pressure-sensitive recording paper consists of the following upper paper, middle paper, and lower paper, or consists of upper paper and lower paper.

Top paper (CB) coated on the back with microcapsules containing an oil in which a leuco dye and / or a chelating color-forming ligand compound is dissolved, and an electron-accepting color developer and / or a chelate color developer on the surface Medium paper (CFB) coated with microcapsules enclosing an oil in which a leuco dye and / or a chelating color forming ligand compound is dissolved on the back surface, and an electron-accepting developer and / or on the front surface Or lower paper (CF) coated with a chelating color developer.

Further, a self-contained paper having a surface coated with a coating composition containing the above-described microcapsules and a color developer is also known.

<Problems to be Solved by the Invention> Meanwhile, in the pressure-sensitive recording paper composed of the upper paper, the middle paper, and the lower paper as described above, or the pressure-sensitive recording paper composed of the upper paper and the lower paper, the microcapsules are broken by pressure, and the Because the oil in the capsule reacts with the developer coated on the color developing paper to react and develop color, the oil viscosity increases and the reaction speed decreases in cold climates. Therefore, there has been a problem that the coloring property is low or coloring takes time.

Therefore, an object of the present invention is to provide a coating layer containing an electron-accepting color developer and / or a chelate color developer and not containing microcapsules containing a leuco dye and / or a chelate color-forming ligand compound. Pressure-sensitive recording paper, a so-called developing paper, provided a coating composition for pressure-sensitive recording paper capable of improving the color developing property and color developing speed, and further using this composition, the color developing property and color developing speed Another object of the present invention is to produce a pressure-sensitive recording paper excellent in quality.

<Means for Solving the Problems> The present inventors have conducted intensive studies to increase the color development and color development speed of the color developing paper. As a result, the coating composition containing the color developing agent contains a polyamide polyamine resin and a polyamide polyamine. The present inventors have found that by containing a resin selected from urea-based resins and coating the same on paper, the coloring property and coloring rate of the resulting pressure-sensitive recording paper can be enhanced, and the present invention has been accomplished.

Therefore, the present invention relates to a 1-membered resin selected from the group consisting of a polyamide-polyamine-based resin and a polyamide-polyurea-based resin.
A pressure-sensitive recording paper coating composition containing at least one kind of resin and at least one kind of developer selected from the group consisting of an electron-accepting developer and a chelate-based developer; Provided is a method for producing a pressure-sensitive recording paper by applying the composition to paper, and further, on the surface of the paper, at least one selected from the group consisting of a polyamide polyamine resin and a polyamide polyurea resin. And a pressure-sensitive recording paper provided with a coating layer containing at least one developer selected from the group consisting of an electron-accepting developer and a chelate-based developer.

In the coating composition of the present invention, or in the resin contained in the coating layer, the polyamide polyamine resin is a polymer compound having an amide bond and an amine bond in the molecule, as a specific example, , Polyamide polyamine-epichlorovidrin resin, polyamide polyamine-glyoxal resin, polyamide polyamine-formaldehyde resin, and the like. The polyamide polyurea-based resin is a polymer compound having an amide bond and a urea bond in a molecule.
Epichlorohydrin resin, polyamide polyurea-glyoxal resin, polyamide polyurea-formaldehyde resin, and the like.

Polyamide polyamine resins are described, for example, in JP-B-58-53.
No. 653, and specifically, for example, a polyamide polyamine which is a reaction product of a polyalkylene polyamine and a dibasic carboxylic acid is reacted with epichlorohydrin, glyoxal, formaldehyde, and the like. Can be manufactured. Further, polyamide polyurea-based resin is, for example, Japanese Patent Publication No. 56-28929.
And the method described in JP-A-58-180529, specifically, for example, a polyamide polyurea which is a reaction product of a polyalkylene polyamine, a dibasic carboxylic acid, and urea, It can be produced by reacting epichlorohydrin, glyoxal, formaldehyde and the like.

Examples of the polyalkylene polyamine used for producing these resins include diethylene triamine, triethylene tetramine, and tetraethylene pentamine.
At this time, ethylenediamine, 1,3-diaminopropane,
Alkylenediamines such as propylenediamine, piperazine, dimethylaminopropylamine and hexamethylenediamine can be used in combination with polyalkylenepolyamines.

The electron-accepting color developer or the chelate color developer used in the present invention is not particularly limited. For example, inorganic acid substances such as acid clay and activated clay, phenol resins such as phenol aldehyde polymers such as p-phenylphenol-formaldehyde polymer and phenol acetylene polymers, furthermore, benzoic acid and p-tert-butyl benzoic acid ,
Salicylic acid, 3-phenylsalicylic acid, 2-hydroxy-1-benzyl-3-naphthoic acid, 1-benzoyl-2
Aromatic carboxylic acids such as -hydroxy-3-naphthoic acid and salts thereof with polyvalent metals such as zinc, aluminum, magnesium and calcium are used as electron-accepting developers. Also, nickel stearate,
Nickel laurate, titanium stearate, iron naphthenate, copper palmitate and the like are used as a chelate color developing agent.

In the coating composition containing such a color developing agent as a main component, various auxiliary agents such as a normal water-soluble or latex-based binder, a white pigment, and further a dispersant, a defoaming agent, a fluorescent whitening agent, and a colored dye. Is blended as needed. Examples of the water-soluble binder include, for example, gelatin, proteins such as casein, oxidized starch, starches such as esterified starch, carboxymethyl cellulose, celluloses such as hydroxyethyl cellulose, polyvinyl alcohol, acrylic resin, acrylamide resin, and the like. Examples of the latex binder include styrene-butadiene latex, acrylate latex, vinyl acetate latex, and carboxy-modified latex thereof. Examples of the white pigment include oxides such as aluminum, zinc, magnesium, calcium, and titanium, hydroxides, carbonates, sulfates, kaolin, and calcined clay. The mixing ratio of the binder varies depending on the type of the binder used.

The content (total) of one or more resins selected from polyamide polyamine-based resins and polyamide polyurea-based resins is 0.01 to 2.0% by weight based on the total solid content of the developer, white pigment, binder, and the like. %, More preferably 0.05 to 2.0% by weight. When the content of this resin is less than 0.01% by weight, the effect of addition is insufficient, and
If the content exceeds 2.0% by weight, the effect does not increase so much and is economically disadvantageous.

The developer coating solution used in the present invention is obtained by pulverizing at least one type of developer selected from an electron-accepting developer and a chelate-based developer and a white pigment into a suitable mill such as a ball mill, a Keddy mill, and a sand mill. It is prepared by adding a binder and at least one resin selected from a polyamide polyamine-based resin and a polyamide polyurea-based resin after the wet or dry treatment with a machine. At this time, the concentration of the developer coating solution is preferably 30 to 75% by weight, more preferably 40 to 75% by weight.
65% by weight. When the concentration is less than 30% by weight, the drying load is increased and the balance between the color developing property and the printability of the obtained developer sheet is easily lost, which is not preferable. On the other hand, if the concentration exceeds 75% by weight, the coating aptitude rapidly decreases, which is not preferable.

The developer coating solution obtained as described above is applied by various known coating methods such as an air knife coater, a roll coater, a blade coater, and a size press coater. The coating method is not particularly limited. Preferred coating amount is the dry weight in 3 to 15 g / m ^2, and more preferably about 4~10g / m ^2. When the coating amount is less than 3 g / m ² , the effect of the color developing paper is insufficient, and when the coating amount exceeds 15 g / m ² , the balance between the color developability and the printability tends to be lost, which is not preferable. Also, the drying method is not particularly limited, and is performed by a hot air system, an infrared system, a drum dryer system, and the like, and a machine calender installed online or offline as necessary,
Finish processing may be performed on a super calender or the like.

<Effect of the Invention> The color-developed paper for pressure-sensitive recording of the present invention obtained as described above is excellent in color-forming properties and color-forming speed after pressure printing. This color developing paper is a medium paper provided with a microcapsule layer containing a leuco dye and / or a chelating color developing ligand compound on the back surface of the paper provided with the color developer layer, or the back surface of the paper. It is used as a base paper without a microcapsule layer.

<Example> Hereinafter, the present invention will be specifically described with reference to examples. The percentages and parts in the examples are on a weight basis.

Reference Example 1 In a 500 ml four-necked flask equipped with a thermometer, a reflux condenser and a stirring rod, 103 g (1 mol) of diethylenetriamine was placed.
Water 10g, adipic acid 138.7g (0.95mol) and 98% sulfuric acid 3g
(0.03 mol) at 155-156 ° C while draining water
The reaction was performed for 13 hours. Thereafter, 205 g of water was added to obtain a polyamidepolyamine aqueous solution. It has a solids content of 50.2%,
The viscosity was 540 cps (25 ° C.). This 50% in another flask
125 g (0.3 g mol) of polyamide polyamine aqueous solution and 186 g of water
And 44.4 g (0.48 mol) of epichlorohydrin was added. The mixture was stirred while keeping the temperature at 60 ° C., and when the viscosity reached 360 cps (25 ° C.), the pH was adjusted to 3.6 with hydrochloric acid. The obtained product had a solid content of 28.6% and a viscosity of 348 cps (25 ° C.).

Reference Example 2 In a four-necked flask equipped with a thermometer, a reflux condenser and a stirring rod, 292 g (2 mol) of triethylenetetramine and urea 60 were added.
g (1 mol), and the reaction was carried out at 145 to 150 ° C. for 4 hours while removing generated ammonia outside the system. Then, 146 g (1 mol) of adipic acid was added, and the condensation reaction was carried out at 150 to 155 ° C. for 5 hours. Was done. After cooling to 120 ° C, 240 g of urea (4
Mol), and a deammonification reaction was carried out at 125 to 130 ° C for 2 hours. Thereafter, 1350 g of water was gradually added to obtain an aqueous solution of polyamide polyurea. Next, 37% formalin 202.5g
(2.5 mol), and the pH was adjusted to 5 with concentrated hydrochloric acid.
The mixture was stirred at 5 ° C for 4 hours. Then cool to 30 ° C, 30
The pH is adjusted to 8 with a 10% aqueous sodium hydroxide solution and the solid content is 30%
Was obtained.

Example 1 In 200 parts of water, 1 part of sodium polyacrylate and 1 part of polyvinyl alcohol were dissolved, and 30 parts of zinc salicylate was further dissolved.
After adding 80 parts of calcium carbonate and 30 parts of kaolin and pulverizing the mixture with a ball mill, 25 parts of a styrene-butadiene copolymer latex (50% concentration) and the aqueous resin solution obtained in Reference Example 1 (28.6% concentration) were used. 1.3 parts (resin content 0.24% based on the total solid content) was added to obtain a coating liquid.

The coating liquid thus obtained was manually applied to a paper having a basis weight of 55 g / m ² by a wire rod so as to have a dry weight of 5 g / m ² , dried in an oven at 120 ° C. for 1 minute, and dried. I got colored paper.

This developed paper is superimposed on commercial paper (Fuji Photo Film's pressure-sensitive paper, Blue A N40 W), and a load of 180 kg / cm ² is applied for 5 seconds, and then 15 minutes, 30 seconds, and 1 minute , 5 minutes and 1 day later, the color density was measured with a Macbeth color densitometer. The results are shown in Table 1.

Example 2 The procedure of Example 1 was repeated, except that the resin aqueous solution obtained in Reference Example 1 was replaced by 1.24 parts (resin content: 0.24% based on the total solid content) of the resin aqueous solution obtained in Reference Example 2. Colored paper was obtained, and the coloring properties were compared in the same manner as in Example 1. The results are shown in Table 1.

Comparative Example 1 The same procedure as in Example 1 was carried out except that the aqueous resin solution obtained in Reference Example 1 was not used, and a comparative color developing paper was obtained. The results are shown in Table 1.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-54-40713 (JP, A) JP-A-53-779611 (JP, A) JP-A-50-6413 (JP, A) JP-A 52-79 88409 (JP, A) Japanese Patent Publication No. 60-12955 (JP, B2) (58) Field surveyed (Int. Cl. ⁶ , DB name) B41M 5/155

Claims (5)

(57) [Claims] 1. An electron-accepting color developer, comprising at least one resin selected from the group consisting of polyamide polyamine resins and polyamide polyurea resins in an amount of 0.01 to 2.0% by weight based on the total solids in the composition. And pressure-sensitive recording paper containing at least one developer selected from the group consisting of a chelate-based developer and a microcapsule containing a leuco dye and / or a chelate-based ligand compound. Composition. 2. The composition according to claim 1, wherein one or more resins selected from the group consisting of a polyamide polyamine resin and a polyamide polyurea resin are contained in an amount of 0.05 to 2.0% by weight based on the total solid content in the composition. Stuff. 3. A method for producing pressure-sensitive recording paper, comprising applying the composition according to claim 1 to paper. 4. A paper surface comprising 0.01 to 2.0% by weight of one or more resins selected from the group consisting of polyamide polyamine resins and polyamide polyurea resins, an electron-accepting color developer and a chelate color developer. 1 selected from the group consisting of agents
A pressure-sensitive recording paper comprising at least one kind of color developer and having a coating layer which does not contain a microcapsule containing a leuco dye and / or a chelate coloring compound. 5. A medium paper having a microcapsule layer containing a leuco dye and / or a chelate-forming ligand compound on the back surface of the paper, or a lower paper having no microcapsule layer. 4. The pressure-sensitive recording paper according to 4.