JPS6394879A - Desensitizing ink for pressure sensitive recording paper - Google Patents

Abstract

PURPOSE:To obtain a desensitizing ink for a pressure sensitive copy paper having excellent desensitizing effect for various developers and causing no recovery of image through water having good set-off performance, by containing a specific desensitizer, ethyl cellulose, pigment and solvent. CONSTITUTION:An adduct where at least 5-50mol of butylene oxide is added to 1mol of amine shown by formula (I) and an adduct where 10-70mol of propylene oxide and ethylene oxide is added to 1mol of said amine such that propylene oxide is added 70mol% or more of total mol are employed in combination as a desensitizer, where the content of the adduct of buthylene oxide is set to 20-90wt% of desensitizer. Ethyl cellulose to be employed as binder has the viscosity lower than 200sec measured by a No.3 Zahn cup when it is dissolved by 5wt% into ethanol, and employed by 40-150wt% for pigment. Alcohols and acetates are employed as diluent such that alcohols occupy 80wt%.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention is a desensitizing ink for pressure-sensitive copying paper, which is particularly free from double images due to water, has excellent suitability for various types of printing, and has improved desensitizing effects and set-off properties. This invention relates to desensitizing ink for pressure-sensitive copying paper.

(Prior art) Electron-donating or proton-accepting colorless organic compounds (
It has been known for a long time that a colored image is obtained by the reaction between a color former (hereinafter referred to as a color former) and an electron-accepting or proton-releasing agent (hereinafter referred to as a color developer).

Pressure-sensitive copying paper (
For example, US Patent No. 2303≠70, US Patent No. 25031719
No. 2! j01A7/No. 23171366, 27/2. T07, same 2730μ! No. 6, 2730
No. 1137, No. 3'1lrJjtO, -, 2- No. jA7.223j), thermal recording paper (for example, Tokusho +
j-4 AI No. 40, AI No. 173-7400, same da j-/
No. 032, U.S. Pat. Furthermore, a printing method is also known in which a colored image is obtained by supplying ink containing a color former to a sheet coated with a color developer (German Patent Application (OLS)/3 Tata No. 2).

The color developer has the properties defined above and includes clays, phenolic resins, metal salts of aromatic carboxylic acids, and the like.

Generally, in pressure-sensitive copying paper, a combination of a layer containing microcapsules containing a coloring agent and a color developer layer is used to obtain a colored image, and these layers are brought into contact with each other to obtain a colored image. This is done by destroying the microcapsules and bringing the color forming agent and color developer into contact.

Generally, these color developers are applied uniformly over the entire surface of the support and used as a color developer sheet, but depending on the purpose of use of the pressure-sensitive copying paper, there may be areas on the side of the color developer sheet that do not require recording. In such cases, a method of desensitizing the color developer sheet by applying desensitizing ink containing a desensitizer to that portion of the color developer sheet using a printing machine or the like is used.

For desensitizing inks used for this purpose, see, for example, US Pat. No. 7,777,710! No., Special Public Show μ Gu 27.
2jj issue, Dohiro, t-2/$44 issue, same≠t-λJtj
No. 1, same≠t-ko February Yumi issue, JP-A-447-j2ri/j
No., Special Publication No. 4'7-312oi, same page, r-Hirojo
No., Tokukai Showa 4tIr-t, Iroj No., Tokuko Showa data p
ara, same tter/ri A4 (7, same≠ter 2300
No. 1, same≠tar, 2Jrzo No., JP-A-Sho Futa-113fu c#, same μ-tar 7cooori No., same ltar No. 7770, same datar No. 77710, same J-tar/6613, same l
Tar f3jt09, German patent application (OLS) 23+
No. 3100, 23! No. 0719, 23Alfj
It is detailed in No. A, Special Publication No. 5R-3RII of the 1970s, etc.

(Problems to be Solved by the Invention) Desensitizing inks used for the above purpose generally contain a desensitizer, a pigment such as titanium dioxide, a binder, and if necessary a diluent such as an organic solvent. No sensitive ink has been found that has an excellent desensitizing effect against various color developers and has good set-off properties. Also, if a desensitizer that is highly soluble in water is used, double images due to water will occur, and if a desensitizer that is insoluble in water is used, the printed area will not be uniform when used for offset printing, which are contradictory characteristics. It had become ink. Furthermore, when offset printing is performed online immediately after desensitizing printing, the previously printed desensitizing ink adheres to the blanket on the offset unit, resulting in a serious drawback of uneven printing on the printed matter.

Therefore, an object of the present invention is to provide a desensitizing ink for pressure-sensitive copying paper that has excellent printability, has an excellent desensitizing effect on various color developers, has good set-off properties, and is free from double images due to water. It's about doing.

(Means to solve the problem) The above objects are achieved by the invention described below.

That is, the present invention provides a desensitizing ink containing a desensitizing agent, a pigment, and a binder, in which the following general formula (1) is used as the desensitizing agent.
) and an adduct obtained by adding at least 5 to 30 moles of butylene oxide to 1 mole of the amine represented by formula (1).
At least 70 to 70 propylene oxide and ethylene oxide are added in total to 1 mole of the amine represented by
mol, and in combination with an adduct in which the number of moles of propylene oxide added in the total number of additions is 70 or more moles,
and the content of the butylene oxide adduct is that of the desensitizer,
20 to 20% by weight, and at least ethyl cellulose is used as a binder, and the ethyl cellulose has a viscosity of 200 seconds or less in a Zahn cup when dissolved in ethanol at a concentration of 4'0- to the pigment. /30
Use % by weight. Furthermore, this was achieved by a desensitizing ink characterized by using alcohols and acetic esters as diluents in an amount of 10% alcohol by weight.

As a desensitizing agent, a color developer having a different acid value, such as a metal salt of salicylic acid and phenol, can be used in combination with ethylene oxide, propylene oxide, and ethylene oxide adducts to the amine represented by formula (1). This ink can be commonly used with resin-based color developers, and has well-balanced solubility in water, resulting in no double images due to water.

The combined use ratio is 20 to 0% by weight, but preferably 3O-
Ir content is 0% by weight.

However, the necessary characteristics of a desensitizing ink cannot be fully satisfied only by using the above desensitizing agent in combination.

That is, the use of the above desensitizers has drawbacks such as high viscosity and high stickiness.1. It is necessary to use at least ethylcellulose as binder. When the desensitizer used in the present invention and ethyl cellulose are dissolved in alcohol, a desensitized ink with low tackiness can be obtained. Furthermore, if acetic acid esters are used in combination as a solvent other than alcohols depending on the required form, the viscosity can be lowered to a desired level. However, acetic acid esters are odorless and dry, so
It is necessary to keep it below the weight limit. The amount of the binder used is ≠θ to 130% by weight, preferably 30 to 80% by weight, based on the pigment. If it is less than 40% by weight, the binder strength will be insufficient, and if it is more than ljO weight f%, it will have a desensitizing effect.
Unbalanced in terms of viscosity.

As the pigment used in the present invention, white pigments such as titanium dioxide, barium sulfate, calcium carbonate, talc, kaolin, and bentonite are used.

Ethyl cellulose is used as a binder, but
In order to adjust the viscosity while maintaining the desensitizing effect, a binder that can be kept at a constant viscosity is required, and for this purpose, the viscosity at 2J 0C when dissolved in ethanol at J weight ratio is 200 in A3 Zahn cup. Must be less than seconds. In addition, other binders may be used together if necessary, but examples of other binders include rosin-modified phenolic resin, ketone resin, polyamide resin, maleic acid resin, phenol resin, epoxy resin, alkyd resin, melamine resin, and urea resin. , nitrocellulose, butyral resin, polyvinyl alcohol, gelatin, shellac, and other natural or synthetic polymeric compounds. The combined use ratio of ethylcellulose is 50% by weight or more, preferably 70% by weight or more of the total A inder.

Alcohols as diluents in the present invention include methanol, ethanol, isopropyl alcohol, etc.
It doesn't have to be just one type. Further, the acetic acid esters include ethyl acetate, butyl acetate, etc., and it is not necessary to use only one type.

The desensitizing ink of the present invention can be used with only the above components, but stabilizers such as ultraviolet absorbers and antioxidants may also be added.

The effect of the desensitizer composition of the present invention was confirmed using the following color developer sheet and color former sheet. The desensitizing ink of the present invention uses an organic solvent, and the printing method is limited to flexographic printing, etc., which can use an organic solvent type.

(Color developer sheet A) 3. Add 70 parts of zinc j-di-α-methylbenzylsalicylate, 20 parts of calcium carbonate, and a portion of zinc oxide powder to 200 parts of water together with 1 part of sodium hexametaphosphate, and grind using a sand grinder. Using the average particle size Hiroshi,!
Dispersed in μm, IO% polyvinyl alcohol 1
00 parts and 70 parts of carboxy-modified styrene-butadiene latex were added to prepare a coating solution. Joy/r this coating liquid
Coat with an air knife coater so that the solid content of sy/m2 is coated on the base paper of n2, dry it and apply the color developer layer) B
I got it.

(Developer Sheet) B) In developer sheet B, 3. A developer sheet C was obtained in the same manner as developer sheet B except that 11 parts of p-phenylphenol resin was used instead of 1 part of zinc J-di-α-methylbenzylsalicylate.

(Preparation of Color Former Sheet) R parts of a sodium salt of polyvinylbenzenesulfonic acid (manufactured by National Starch Co., Ltd., VER8A, 'fL600, average molecular weight zooooo) were added to hot water at about ro 0C with stirring. After dissolving for about 3θ minutes, it is cooled. The pH of the aqueous solution was λ~3, and a 20% by weight aqueous sodium hydroxide solution was added thereto to adjust the pH to <<, o.

On the other hand, j% crystal violet lactone and 7
．． 100 parts of diisopropylnaphthalene in which 0% benzoleicomethylene blue was dissolved was emulsified and dispersed in ioo parts of a j% aqueous solution of a partial sodium salt of the polyvinylbenzenesulfonic acid to obtain an emulsion having a particle size of average diameter ≠ j μm. . Separately, 1 part of melamine, 1 part of a 37% by weight aqueous formaldehyde solution, and 30 parts of water were heated to 60°C, and after 30 minutes, a transparent mixed aqueous solution of melamine formaldehyde and the intended condensate of melamine formaldehyde was obtained.

The pH of this mixed aqueous solution was 6 to lr. Hereinafter, this mixed aqueous solution of melamine formaldehyde and melamine-formaldehyde intended condensate will be referred to as the intended condensate solution.

The desired condensate solution obtained by the above method was added to and mixed with the above emulsion, and the pH was adjusted with 3.6% by weight hydrochloric acid solution while stirring.
The temperature of the solution was raised to 7j'C, and the mixture was heated for 31.0 minutes. Cool this capsule liquid to room temperature and 1.2
The pH was adjusted to O with 0% by weight of sodium hydroxide.

To this capsule dispersion, 200 parts of a 70% by weight polyvinyl alcohol aqueous solution and 10 parts of starch particles were added, and water was added to adjust the solid content concentration to 2 ozb to obtain a color former-containing microcapsule coating solution.

Apply this microcapsule coating solution to toy/m2 base paper.
Coat with an air knife coater so that a solid content of 3 on the colorant surface/rrL
2. Apply it evenly and overlap it with the unapplied developer side.
Apply weight of o y / cy2, Jj 0C1♂O
%RH for 5 minutes. The stains caused by the desensitized ink on the uncoated areas were observed and evaluated as follows.

○: No stains were generated.

Δ; Dirt has occurred, but Characters remain even when copied over a coloring agent sheet. No blurring.

×: Too dirty to be of practical use.

(Printing suitability 1) After desensitizing printing was performed using a flexo printing machine, offset printing was performed using a general ink on the desensitizing ink, and the printing finish of the general ink was evaluated as follows.

○: Good finish was achieved even when printing at 1000 m.

△: Good finish was achieved until 2000m printing.

×: Offset printing is possible on the desensitized ink printing area and is difficult.

(Desensitizing effect) Color developer sheet) Amount of desensitizing ink applied to A, B, and C: 3° ()
y/m 2 , and it was evaluated whether desensitization was sufficient using a color former sheet.

○: Direct extraction from printing was also sufficiently effective.

△；It didn't work right after printing the mark, but It was sufficiently effective after stable to minutes.

×: No effect even after -1 day after printing.

(Double image with water) Color developer sheet) Print the desensitizing ink on A at 2y/m2, overlap it with the color developer sheet, print with a typewriter, and drop water/ml onto the printed area with a dropper. did. The level of double images due to water was observed and evaluated as follows.

○: No recurrence caused by water △: There is some double image due to water, but When the water dries, it disappears again.

×: There is a double image due to water, Even when the water dries up, there are even trenches that are duplicated.

(Example) Ink was prepared as follows using the combination of materials shown in Table 1 and the composition shown in Table 2, and printed by flexographic printing.

The binder was added to the diluent and allowed to rise for 30 minutes.

The above binder solution was kneaded with a desensitizer for 2 μ hours using a ball mill to obtain an ink.

-／　l- Table 3 Patent applicant: Fuji Photo Film Co., Ltd.-/r-

Claims (1)

[Scope of Claims] A desensitizing ink for pressure-sensitive copying paper containing a desensitizer, ethyl cellulose, a pigment, and a solvent, at least butylene oxide per mole of an amine represented by the general formula (1) as the desensitizer. an adduct obtained by adding 5 to 50 moles of amine, and at least 10 to 70 moles of propylene oxide and ethylene oxide in total addition number per mole of amine of general formula (1), and the number of moles of propylene oxide in the total number of additions is 70 The content of the butylene oxide adduct is 20 to 90% of the desensitizer.
% by weight, and the ethyl cellulose has a viscosity at 25°C of No. 1 when dissolved in ethanol at 5% by weight. 200 seconds or less in 3 Zahn cups, 40 to 150% by weight of the pigment is used, and alcohols and acetic esters are used as solvents so that the alcohol content is 80% by weight or more. Desensitizing ink for pressure copy paper. H-[NH-(CH_2)_2]-_nNH_2(1) where n is an integer from 1 to 5