JPH01258982A - Coating composition for pressure-sensitive recording paper - Google Patents

Abstract

PURPOSE:To enhance color-forming properties and color-forming speed, by a method wherein a coating composition for pressure-sensitive recording paper is prepared by compounding a resin such as a polyamine resin and one or more types of electron accepting color developers and chelate color developers. CONSTITUTION:A coating composition for pressure-sensitive recording paper is prepared by compounding one or more types of resins selected from among groups made of polyamide polyamine resin, polyamide polyurea resin, and polyamine resin and one or more types selected from among electron accepting color developers and chelate color developers. In this coating composition, additives, such as a latex binder, a white pigment, and a dispersant, can be compounded, and the resin such as polyamide polyamine resin is preferably incorporated in the amount of 0.01-5.0wt.% per the additives. A pressure- sensitive recording paper is obtained by applying the aforesaid coating composition on paper by an air-knife coater etc.

Description

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

<Conventional technology and its problems> Pressure-sensitive recording paper is used in large quantities for various forms and the like.

In general, pressure-sensitive recording paper consists of a top paper (CB) coated with microcapsules containing oil in which a leuco dye and/or a chelate color-forming ligand compound is dissolved on the back side, and an electron-accepting color developer and an electron-accepting color developer on the front side. /
Or medium paper (CFB) coated with a chelate color developer and coated with microcapsules containing oil in which a leuco dye and/or a chelate color-forming ligand compound is dissolved.
), consisting of a base paper (CFB) coated with microcapsules whose surface is coated with an electron-accepting color developer and/or a chelate color developer. Also known is self-contained paper whose surface is coated with a coating composition containing the above-mentioned microcapsules and a color developer.

However, in such pressure-sensitive recording paper, the microcapsules are destroyed by pressure, and the oil in the microcapsules contacts and reacts with the color developer coated on the color developer paper, resulting in color development. There were problems such as increased viscosity and decreased reaction rate, resulting in poor color development and a long time required for color development.

<Means for Solving the Problem> As a result of intensive studies to improve color development properties and color development speed, the present inventors found that polyamide polyamine resins and polyamide polyurea resins were added to coating compositions containing color developers. The present inventors have discovered that color development properties and color development speed can be improved by incorporating one or more resins selected from polyamine resins and polyamine resins. The polyamide polyamine resin of the present invention includes polyamide polyamine-epichlorohydrin resin, polyamide polyamine-epichlorohydrin resin, and polyamide polyamine-epichlorohydrin resin.
Examples include glyoxal resin, polyamide polyamine-formaldehyde resin, and the like. Examples of the polyamide polyurea resin include polyamide polyurea-epichlorohydrin resin, polyamide polyurea-glyoxal resin, and polyamide polyurea-formaldehyde resin. Examples of polyamine resins include polyalkylene polyamine-epichlorohydrin resin, polyalkylene polyamine-epichlorohydrin-dialkyl sulfate resin, alkylene diamine-alkylene dino monolide resin,
Examples include polyethyleneimine.

For example, polyamide polyamine resin is disclosed in Japanese Patent Publication No. 58-53
It can be obtained by the method described in No. 653.

For example, polyamide polyurea resin is disclosed in Japanese Patent Publication No. 56-28
No. 929 and JP-A-58-180529.

The polyamine resin is obtained, for example, by reacting a polyalkylene polyamine with epichlorohydrin, further reacting a dialkyl sulfate such as diethyl sulfate, or reacting an alkylene diamine with an alkylene civalide.

Examples of polyalkylene polyamines include diethylenetriamine, triethylenetetramine, and tetraethylenepentamine. Examples of the alkylene diamine include ethylene diamine, 1,3-diaminopropane, propylene diamine, piperazine, dimethylaminopropylamine, and hexamethylene diamine.

Examples of the alkylene cybaride include ethylene dichloride, propylene dichloride, and ethylene dibromide.

The electron-accepting color developer or chelate color-forming color developer used in the present invention is not particularly limited. For example, acid clay,
Inorganic substances such as activated clay, phenolic resins such as phenolic aldehyde polymers such as p-phenylphenol-formaldehyde polymers and phenolic acetylene polymers, as well as benzoic acid, p-tert-butyl-benzoic acid, salicylic acid, Aromatic carboxylic acids such as 3-phenylsalicylic acid, 2-hydroxy-1-benzyl-3-naphthoic acid, and 1-benzoyl-2-hydroxy-3-naphthoic acid, and aromatic carboxylic acids such as zinc, aluminum, magnesium, and calcium. Salts with valent metals are used as electron-accepting color developers. Also nickel stearate,
Nickel laurate, titanium stearate, iron naphthenate, copper palmitate, and the like are used as chelate color developers.

Coating compositions containing such color developers as main components contain conventional water-soluble or latex binders, white pigments, and various auxiliary agents such as dispersants, antifoaming agents, optical brighteners, and colored dyes. Mixed as necessary. Examples of water-soluble binders include proteins such as gelatin and casein, starches such as oxidized starch and esterified starch, celluloses such as carboxymethyl cellulose and hydroxyethyl cellulose, polyvinyl alcohol, acrylic resin, acrylamide resin, etc., and latex-based Examples of the binder include styrene-butadiene latex, acrylate latex, vinyl acetate latex, and carboxy-modified latexes thereof.

Examples of white pigments include oxides, hydroxides, carbonates, and sulfates of aluminum, zinc, magnesium, calcium, and titanium, and viscosities such as kaolin and calcined kaolin. The blending ratio of the binder varies depending on the type of binder used.

The content (total) of one or more resins selected from polyamide polyamine resin, polyamide polyurea resin, and polyamine resin is based on the total solid content of color developer, white pigment, binder, etc. , preferably 0.01~
5, (1 wt%, more preferably 0.05 to 2.
Owt%. When the content is less than 1wt%, the effect of addition is insufficient, and when the content is less than 5.0wt%
Even if the amount exceeds 100%, the effect does not increase much and it is economically disadvantageous.

The color developer coating solution used in the present invention is prepared by grinding one or more types of color developer selected from electron-accepting color developers and chelate color developers and a white pigment in a suitable pulverizer such as a ball mill, kedimir, or sand mill. After processing in a wet or dry manner, it is prepared by adding a binder and one or more resins selected from polyamide polyamine resins, polyamide polyurea resins, and polyamine resins. The developer coating solution concentration at this time is preferably 30 to 75 wt%,
More preferably 40~(i5wt%.The concentration is 3Q
When it is less than wt%, the drying load becomes high and the balance between the color development and printability of the resulting color developer sheet tends to be lost, which is not preferable.

Moreover, if the concentration exceeds 75 wt%, the coating suitability will drop sharply, which is not preferable.

The developer coating solution obtained as described above is coated by various known coating methods such as an air knife coater, roll coater, blade coater, and size press coater. The coating method is not limited to poetry. The preferred coating amount is about 3 to 15 g/rn' in terms of dry weight, more preferably about 4 to 10 g/rn'. 3g/
If it is less than m'', the effect of the color developing paper is insufficient,
If it exceeds 15 g/m'', the balance between color development and printability tends to be lost, which is undesirable.The drying method is also not particularly limited, such as hot air method, infrared method,
This is carried out using a single-type drum dryer, etc., and finishing may be performed using a reta machine calender, super calender, etc. installed online or offline as required.

<Effects of the Invention> The color developing paper for pressure-sensitive recording of the present invention obtained as described above has excellent color development properties and color development speed after pressure printing.

This effect can be obtained not only for middle paper and bottom paper but also for self-contained paper.

<Example> This will be explained in detail below using Examples.

Reference Example-1 In a 500-meter flask equipped with a thermometer, a reflux condenser, and a stirring bar, 103 g (1 mole) of diethylenetriamine, 10 g water, 138.7 g (0.95 mole) adipic acid, and 3 g (0.95 mole) of 98% sulfuric acid were added. 03 mol) and reacted at 155 to 156° C. for 13 hours while pouring water. 205 g of the fine water was added to obtain a polyamide polyamine aqueous solution. This product has a solid content of 50.2% and a viscosity of 540 cps.
(25°C). In a separate flask, add 125 g (0.3 g mol) of this 50% polyamide polyamine aqueous solution.
and 186 g of water, and 44 g of epichlorohydrin.
4 g (0.48 mol) were added. The mixture was stirred while keeping it warm at 60°C, and when the viscosity reached 360 cps (25°C), the pH was adjusted to 3.6 with hydrochloric acid. The resulting product had a solids content of 28.6% and a viscosity of 348 cps (25°C).

Reference Example-2 292 g (2 moles) of triethylenetetramine and 60 g of urea were placed in a four-way flask equipped with a thermometer, reflux condenser, and stirring bar.
g (1 mol) and reacted at 145 to 150°C for 4 hours while removing generated ammonia from the system,
Next, 146 g (1 mol) of adipic acid was added, and the
Linearization reaction was carried out at 155°C for 5 hours. After cooling to 120°C, add 240g (4 moles) of urea to 125-130°C.
Ammonia removal reaction was carried out for 2 hours. After that, water 135
0 g was gradually added to obtain an aqueous solution of polyamide polyurea.

Next, 202.5 g (2.5 moles) of 37% formalin
was added, and the pH was adjusted to 5 with concentrated hydrochloric acid, followed by stirring at 65° C. for 4 hours. Then cool to 30℃ and 30%
Adjust pH to 8 with caustic soda aqueous solution, solid content 30%
An aqueous thermosetting resin solution was obtained.

Reference Example-3 (Synthesis of Compound x-1) In a four-way flask equipped with a thermometer, reflux condenser, and stirring bar, 44 g (0.3 mol) of triethylenetetramine and 1 mol of water were added.
Prepare 89g, then add 167g of epichlorohydrin.
(1.8 mol") was added while maintaining the internal temperature at 40°C. Thereafter, the reaction was continued at 40°C for 2 hours and then cooled to obtain a 50% aqueous solution of Compound X-t.

(Synthesis of Resin Y-1) After cooling with a thermometer and reflux, 292 g (2 mol) of triethylenetetramine and 60 g of urea were placed in a four-way flask equipped with a stirring bar.
g (1 mol) was charged, deammoniation was carried out at 150 to 158°C for 3 hours, and then cooled to 130°C,
Add 240g (4 mol) of urea and heat at 130-135℃ for 2 hours.
A time deammonification reaction was performed. 550 g of the soaked water was gradually added to obtain a polyamide polyurea aqueous solution.

Next, 121.5 g (1.5 mol) of 37% formalin was added, the pH was adjusted to 4 with 2ON-sulfuric acid, and the pH was adjusted to 4 at 70°C.
The mixture was kept warm and stirred for an hour. After that, it was cooled to 30°C, adjusted to 6.5 with a 30% caustic soda aqueous solution, and the solid content was 5.
0% of resin Y-1 was obtained.

(Synthesis of resin) ``Put the entire amount of compound X-t and the entire amount of resin Y-1 into a four-way flask equipped with a thermometer, reflux condenser, and stirring bar,
After reacting at 35-40°C for 2 hours, plating with 2ON sulfuric acid
H was adjusted to 4 to obtain an aqueous solution of thermosetting resin with a solid content of 50%.

Reference example-4 103.2g (1 mol) of diethylenetriamine was mixed with 19g of water
5.7 g of epichlorohydrin was dissolved in the solution, and 120.3 g (1.3 mol) of epichlorohydrin was added dropwise over 5 hours to react while maintaining the internal temperature at 50°C. Then, using 28% caustic soda to maintain the pH in the system at 8 to 9, diethyl sulfate was added to 92.5.
g (0.6 mol) was gradually added and reacted for 3 hours at a temperature of 40°C, and then water was added to give a solid content of 50% and a viscosity of 19 cps.
(25° C.) An aqueous resin solution was obtained.

Example-1 1 part of sodium polyacrylate and 1 part of polyvinyl alcohol were dissolved in 200 parts of water, 30 parts of zinc salicylate, 80 parts of calcium carbonate, and 30 parts of kaolin were added, and after pulverizing this in a ball mill, styrene was dissolved. -25 parts of butadiene copolymer latex (50 parts concentration) and 1.3 parts of the resin liquid obtained in Reference Example-1 (28.6% concentration) were added to obtain a coating liquid.

The coating solution thus obtained was hand-coated with a wire rod to a dry weight of 5 g/m' on paper with a basis weight of 55 g/m1, dried in an oven at 120°C for 1 minute, and then coated on developer paper. I got it.

Layer this developer paper on a commercially available paper (Fuji Photo Film Pressure Sensitive Paper Blue A N40W), and apply a pressure of 18
After applying a load of 0 kg/ctl for 5 seconds, the color density was measured using a Macbeth color densitometer 15 seconds, 30 seconds, 1 minute, 5 minutes, and 1 day later. The results are shown in Table-1.

Examples-2 to 4 In place of the resin liquid obtained in Reference Example-1, 1.24 parts, 0.74 parts, and 0°7 of the resin liquids obtained in Reference Examples-2 to 4 were added, respectively.
A color developing paper was obtained in the same manner as in Example 1, except that 4 parts were used, and the color development properties were compared in the same manner as in Example 1. Display the results -
Shown in 1.

Comparative Example-1 The pond in which the resin liquid obtained in Reference Example-1 was not used was the same as that in Example 1.
A comparative color developing paper was obtained in the same manner as above, and the color development properties were compared. The results are shown in Table 1.

[Margin below]

Procedural amendment (voluntary) 1989 4
Month) L/Day ・

Claims (2)

[Claims] (1) One or more resins selected from the group consisting of polyamide polyamine resins, polyamide polyurea resins, and polyamine resins, and one or more resins selected from the group consisting of electron-accepting color developers and chelate color developers. A coating composition for pressure-sensitive recording paper containing a color developer. (2) A method for producing pressure-sensitive recording paper, which comprises coating paper with the coating composition for pressure-sensitive recording paper according to claim 1.