JPS606796B2 - Desensitizer composition for recording paper - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides carbonless pressure-sensitive recording paper or thermal recording paper which is a recording paper made of a combination of an electron-donating colorless compound and an electron-accepting compound or a solid acid. The present invention relates to desensitizer compositions for inhibiting color-forming reactions upon contact with receptor compounds or solid acids.

Pressure-sensitive recording paper is usually made of crystal violet lactone,
benzoyl.

Electron-donating leuco dyes such as icomethylene blue, mafkite green lactone, rhodamine anilinolactam, and 3-diethylamino-6-methyl-7-anilinofluorane are dissolved in a fixed oil and incorporated into fine capsules and applied. The top paper has been activated whiteness, acid clay,
It consists of a bottom paper coated with an electron-accepting substance such as attapulgide, various phenol resins, salicylic acid derivatives or metal salts thereof, or a solid acid (i.e., an acidic substance) together with a suitable binder, with the coated surfaces of both papers facing each other. When the leuco dye and solid acid are placed on top of each other and pressure is applied by writing or using a typewriter, the capsule in the pressurized area is destroyed and the leuco dye and solid acid come into contact and develop color. Furthermore, if an inner sheet coated with a solid acid (acidic substance) on the front side and a capsule containing leuco dye on the back side is used by sandwiching it between the upper sheet and the lower sheet, an even larger number of copies can be obtained. Thermal recording paper is usually made of powders of lactone-type leuco dyes (electron donors) such as crystal violet lactone, malachite green lactone, and 3-diethylamino-6-methyl-7-anilinofluorane, as well as bisphenol A and salicylic acid. It is made by coating a conductor or its metal salt, or a typical powder of a grouped organic acid such as a novolac-type phenol resin, together with a binder, on a support such as paper. (The powder on one side melts and the leuco dye and acid come into contact with each other to form a color.Therefore, pressure-sensitive recording paper and heat-sensitive recording paper have the same chemical reaction mechanism for coloring reactions.The desensitizer is a pressure-sensitive It is used for the purpose of pre-coating areas of the electron-receiving surface of recording paper that do not require color development to prevent color development, or partially covering the surface that has already developed color to erase a developed color image.

In the case of heat-sensitive recording paper, if a sensitizing agent is similarly applied to the heat-sensitive layer, color development can be inhibited and the developed color image can be erased. Conventionally known desensitizers include, for example, cationic quaternary ammonium salts (e.g., aliphatic amine acetate containing dodecyltrimethylammonium chloride) described in Tsubaki Publication No. 33-3921. minacetate)
"Higher aliphatic amines (e.g., oxazoline derivatives containing dodecyldiamine (e.g., 204,4-trimethyl-2-oxazoline), grade amines (e.g.
N・N-di polyoxyethylene ethylamine) "Polyoxyethylene monoalkyl ester (general formula RCO○ (C2 ratio 0) mH
, R' is an alkyl group having 12 to 18 carbon atoms; e.g., polyoxyethylene oleyl ester), Japanese Patent Publication No. 49-238
Propylene oxide adducts of alkylene diamines (e.g. topolyoxypropylene jetylamine) described in Publication No. 5P to poly-y-alkylglutamate in Japanese Patent Publication No. 49-4484, polyamine-ethylene in Thin Publication No. 49-23008 Oxide addition compound, Tokuseki Sho 49-7200
Amine-glycidyl ester (or ether) adduct compound of No. 9 to polypropylene glycol of JP-A-50-37507; The diazapicycloalkenes of 15513-1972 and others are mentioned, but most of them are basic nitrogen-containing amine compounds with relatively high molecular weights and "attack acidic substances such as acid clay and organic acids. It has the effect of neutralizing it and eliminating or reducing its coloring ability.

Now, a wide range of research has been conducted on methods for improving the coloring ability of the coloring layer (i.e., the acidic substance coated layer) of the inner and lower sheets of pressure-sensitive recording paper. Kosho 48
In Publication No. 19722, it is proposed that coloring ability is improved by adding salts of metals selected from the group consisting of zinc, tin, calcium, magnesium, strontium, manganese, cobalt, nickel, etc. to the phenolic resin-kaolin layer, such as zinc chloride. Kaizen also discloses that the reduction in fading of colored images has been achieved.Also, ``The United States The G Champion $beichi/Guichi Mother's Force.Limited''
Publication No. 110855 states, ``When an organic acid is adsorbed to an inorganic pigment such as titanium oxide, zinc oxide to barium sulfate ÷ calcium sulfate, and applied to a transfer paper (that is, to form a coloring layer), ``the above inorganic pigment and acid This clearly indicates that polyvalent metal compounds have the effect of improving color development and stabilizing color images.On the other hand, Kanzaki Paper Co., Ltd. In Japanese Patent Publication No. 49-10856, “Organic acid metal salt (
For example, it has been announced that when a metal oxide (for example, zinc salicylate) is used in combination with a metal oxide (for example, zinc oxide), the coloring ability becomes particularly remarkable, and the color image also becomes more solid.

Furthermore, Fuji Photo Film Co., Ltd. was also
No. 51, aromatic carboxylic acids or their anhydrides (
It has been shown that when benzoic acid, benzoic anhydride, salicylic acid, etc.) and a metal compound (e.g. zinc oxide) coexist, the color developing ability is stronger and the light fastness of the color image is stronger than when each is used alone. Says.

And American Jen.

Sekisho Hakama, 51, applies for C$R8 Corporation.
No. 1,127,817 discloses that coatings of formulations such as hydroxy-substituted aromatic carboxylic acid derivatives and rainbow group metal oxides and carbonates result in reduced material usage, improved stability and faster print development. It is stated that this can be achieved. In Hakama Kaisho No. 52-32716, Mizusawa Chemical Industry Co., Ltd. discloses a mixture or reaction product of an active silicic acid compound and zinc hydroxide or basic inorganic acid zinc, which has very excellent coloring performance and after coloring. It is also proposed as a coloring agent with good light resistance.

In this way, it seems that most people are recognizing that metal compounds such as zinc compounds are effective in improving the activity of color-forming parts (acidic substances), but from the perspective of t-direction desensitization technology, it is difficult. Problems are emerging.

This is because, in the case of metal-sensitized color-forming layers as mentioned above, conventionally known sensitizers cannot sufficiently reduce the color-forming ability of the metal-sensitized color-forming layer. Even after the ink (called ink) is applied, it still retains its coloring ability, and when printed on top paper, readable characters appear, which can cause problems.

Such troubles can occur when any leuco dye is used as a pressure-sensitive dye (electron donor), especially when
...This phenomenon frequently occurs when a black color-forming fluoran dye typified by diethylamino-6-methyl-7-anilinofluorane is used.

The situation is similar in the case of thermal recording paper. An object of the present invention is to provide a desensitizer composition with improved desensitizing ability. In particular, it is an object of the present invention to provide a desensitizer composition suitable for application to a metal-sensitized color-forming recording layer. The object of the present invention is achieved by incorporating a ligand for a metal ion into a desensitizer composition for recording paper.

Any ligand (ligand, Li scale) can be effective in the present invention, but it has to be low in volatility, stable, soluble in solvents and vehicles, not colored, etc. Due to the above requirements, there are naturally restrictions on the selection range of suitable acid positions, and according to research by the present inventors, the compounds shown in the following compound examples were particularly suitable for use in the present invention.

Examples of suitable ligands: General formula (1) (where R, R2 is an alkyl group such as methyl or tert-butyl, a phenyl group which may have a substituent such as phenyl or p-chlorophenyl, An acetylacetone derivative represented by a fluoromethyl group (representing a group selected from the group consisting of a furyl group and a chenyl group, and R and R2 may be the same or different).

Tri-substituted phosphine oxides represented by the general formula (b) (t), (R3 represents an alkyl group such as n-looptyl, 2-ethylhexyl, n-octyl, or a dialkylamino group such as dimethylamino) .

A macrocyclic ether (crown ether) represented by the general formula (m) (ta), (R4 represents a hydrocarbon residue such as 1,2-ethylene, 1,2-phenylene, 112-cyclohexylene).

In addition to these, many other ligands are useful in the present invention, such as N.N'-dimethylimidazolidinone, tetramethylethylenediamine, cryptand, and the like.

What these ligands have in common is that when they form coordination compounds with various metal ions, they provide coordination compounds that are soluble in organic solvents, in other words, they are metal ion solvent-solubilized sardine ligands.

That is, among the ligands useful in the present invention, there are many that are known as ligands that significantly increase the solubility of metal ions in solvent extraction particles or organic solvents.

As is well known, ligands (ligands, Li saddle) form coordination compounds with various metal ions and exhibit a masking effect, depending on their stability constants, and extremely reduce the concentration of free metal ions. It has the effect of reducing

The reason why the cupboard is effective in the present invention is thought to be due to this concealing effect, but it may be due to other reasons, and it cannot be determined with certainty. However, the effects are clear. Specific examples of ligands that exhibit remarkable effects in the present invention are listed below.

[Group 1] Acetylacetone and its derivatives (number)
(Chemical structural formula)・1 1-2 1-3 1-4 1-5 1-6 1-7 1-8 1-9 [Group B] Tri-substituted phosphine oxide 1□
-2 D-3 Rho 4 [Group 2] Macrocyclic ether (crown ether) m-I DI-2 m-3 [Group W] Other ligands W-I W-2 W-3 W- 4 The above N-2 is a ligand representative of cryptands,
other! cryptands are also useful in the present invention.

To actually incorporate these ligands into a desensitizer composition,
It is desirable to add it in addition to the original desensitizer.

The amount may vary depending on the purpose and quality design, but it is certain that it may be less than the desensitizer content. Also, 1
If you use not only the seeds alone, but also the above-mentioned numbers 1-7 and Roe 3, they may produce extremely effective results due to their mutual effect, so it is also good to mix two or more types. That is, when preparing a printing ink (so-called desensitizing ink) by mixing a binder resin, white pigment, vehicle, desensitizing agent, etc. according to a conventional method, type i or two or more of the flagellates may be blended.

In this case, it is easily possible for those skilled in the art to form printing ink through various printing methods such as letterpress (for example, rubber letterpress), flexo, gravure, and offset. It can be applied directly to the surface of paper coated with a substance or solid acid, or to the surface of heat-sensitive recording paper using various printing methods such as those mentioned above.Also, it can be applied directly by dissolving it in a solvent such as alcohol, preferably with a desensitizing agent. Although it is possible to prepare a composition by treating the ligand used in the present invention in the same way as a known desensitizer, the desensitizing effect can be sufficiently exerted. The true value of the present invention will be best demonstrated when it is added to the sensitizing agent that may be developed in Write down.

Example First, a desensitizing ink having the following composition was prepared.

Polypropylene glycol (average degree of polymerization 12) diglycidyl ether terminal epoxy n-butyrate (desensitizer)
5 parts by weight (the same applies hereinafter) varnish (5 parts of ketone resin dissolved in 5 parts of polypropylene glycol) 3 parts of titanium oxide
1 part of the ligand was mixed into 9 parts of this desensitizing ink.

The effect of this ligand was investigated by the following test. Using an IOT printing tester, ink was applied onto a metal-sensitized color-forming layer-bearing paper (lower paper) prepared in the manner described below so that the amount of ink was 1.5 ta'. Afterwards, the coated surfaces were placed facing each other with black coloring paper (Black CB) manufactured by Mitsubishi Paper Industries, and the optical reflectance was measured after 2 hours by passing it through a calendar under specified conditions.Test results are shown in Table 1.

Table 1 shows that when a ligand is added as in the present invention, the ability of the desensitized ink to inhibit color development is improved.

In addition, as a practical test, when I tried printing with a typewriter on black colored paper, it was found that the area printed with desensitized ink without a ligand was weakly colored and readable, but The areas printed with the added desensitizing ink were strongly desensitized, and especially the areas where the inks containing D-2 and RO 3 were added were completely unreadable.

A pressure-sensitive recording paper base sheet was prepared by coating a color former formulation onto a base paper having a basis weight of approximately 40 mm as follows. [Method for preparing metal-sensitized color-forming layer-bearing paper] 1 part of 305-di(Q-methylbenzyl)salicylic acid (
parts by weight, hereinafter the same) and zinc oxide
3 anchor parts were crushed and dispersed into 20 anchor cities.

At this time, a small amount of dispersant was added. After adjusting the water to slightly alkaline with ammonia water, the carp was heated for 2 hours. Next, it was mixed with a dispersion of 7 parts of kaolin and 14 parts of melon water. Furthermore, “
10 parts of a 10% modified starch aqueous solution and 1 part of a 50% styrene-butadiene latex were mixed.

Claims (1)

[Claims] 1. A desensitizer composition for recording paper with improved desensitizing ability, characterized by containing one or more metal ion solvent-solubilizing ligands among organic ligands for metal ions.