JPS58138689A - Pressure-sensitive recording medium - Google Patents

Abstract

PURPOSE:To raise the speed and density of coloring and also the fastness of color picture by jointly using an activated clay as a developing agent and a specific p-hydroxybenzoate compound on the acceptor side of a pressure-sensitive recording system. CONSTITUTION:An activated clay, obtained by treating an acid clay (e.g., montmorillonite clay mineral, etc.) with a mineral acid, and a p-hydroxy benzoate compound of the formula (R is aryl or aralkyl) are mixed and dispersed in water. The dispersion is coated on a paper to form a lower sheet. Then, a solution of an electro donative colorless dye (e.g., triphenylmethane lactone-type dye, etc.) in an aromatic hydrocarbon high-boiling solvent is micro-capsulated, and a paint composed primarily of the micro capsules is coated on a paper to form an upper sheet.

Description

[Detailed Description of the Invention] The present invention relates to a pressure-sensitive recording system, and in detail,
By mixing the donor IIki composition with the acceptor composition, the color development property, the fastness of the developed color image, and the stability of the non-image area (white background) can be improved. The present invention provides a pressure-sensitive recording system that is more comfortable to wear and has excellent practicality.

A pressure-sensitive recording system is a free-standing recording system that applies a color reaction caused by contact between a donor composition and an activator composition. Usually, on the donor side, an electron-donating colorless dye is dissolved in a high boiling point solvent to form fine particles. The acceptor side consists of an electron-accepting solid acid (often referred to as a coloring agent) embedded in a microcapsule and coated with a sheet-like support K11l (CI) in a sheet together with other auxiliary materials. The material is made of (CF) which is coated on a shaped support.

During recording, when the coated surfaces of both sheets are stacked so that they face each other and pressure is applied using a pen, typewriter, impact printer, etc., the microphone capsule on the donor side of the pressure S separation is destroyed. Therefore, the boiling point solvent bath liquid is liberated, transferred and donated to the accessor side, encounters the electron acceptor acid, and the colorless dye is adsorbed and ionized to the developer surface, or the high boiling point solvent is colored. The agent is deposited and dissolved to substantially change the colorless dye S solution to the acidic side, thereby ionizing the colorless dye and forming a colored image.

(Also, apply the donor composition on one side of the sheet-like support,
middle circumferential seam coated with an acceptor composition on the other side) (
If a CFI) is inserted between the soil sheet and the bottom sheet, an even larger number of records can be obtained. In addition to such separate chicks, there are also self-contained chicks in which 1 ml of both the donor and acceptor compositions are applied in a laminated form or in a single layer on one side of the sheet, but since the coloring mechanism is the same, Within the scope of the present invention. ) Electron-donating colorless dye [is 3,3-bis(p-dimetal)-6-dimethylanotutalide (
trinoenylmethane dyes represented by so-called crystal violet fluorocarbons, fluoran dyes represented by 3-dibutylamino-6-methyl-7-anilic acid fluorine, other acylated leucothiazine grave dyes, and acylated leucothiazine dyes. Four icoquinazine irrigation dyes, lactams,
There are subipitsun, etc., which are used in the original @smell.

Examples of high boiling point solvents include alkylnaphthalenes such as diisopropylnaphthalene, diallylakanes such as l-7E-l-xylylethane, alkylpiphenyls such as isopropylbiphenyl, other triallyldimethanes, and alkylbenzenes. Aromatic hydrocarbons such as benzylnaphthalenes, diallylalkylenes, allylindanes, etc., dibutyl dibutate,!
Carboxylic acid ester compounds represented by dioctyl oleate; Phosphoric acid ester compounds represented by tricresyl trous 7 black 1! oil, soybean oil, cottonseed oil, natural animal and vegetable oils or their modified products, such as mineral oil.
(High-boiling fractions of natural products (consisting of aliphatic hydrocarbons), etc.) However, in the present invention, aromatic aspect ratio hydrogen is preferably used, so it becomes one of the essential components.

Electron-accepting solid acids (1111 colorants) include acid clay, natural minerals such as attapulgite clay, and activated clay organic acid developers prepared by treating acid clay, a montmorillonite clay mineral, with mineral acids as inorganic color developers. As coloring agents, various phenolic compounds, Novotsuku Wi phenol resin, aromatic carboxylic acid polyvalent metal salts, etc. have already been proposed, but the above inorganic color developers have poor coloring stability (easily photobleached, and water resistant). or water vapor), and adsorbs substances in the air, reducing coloring ability (II! Product shelf life is short)
Organic acid group colorants have a slow color development speed, and the color of the square color may fade when it comes into contact with plasticizers or oil, and the non-wire areas (white background) may be exposed to sunlight. Another drawback is that it yellows due to oxidizing gases such as electron oxides in the air. In order to overcome these drawbacks, N1 loading was achieved by heating and combining an inorganic coloring agent and an organic acid color developer, and although progress and improvement were seen in some respects, the white background of the bottom paper However, satisfactory results have not yet been obtained due to the fact that the yellowing of the material is promoted.

The present invention contains 11 liquids of an aromatic hydrocarbon high-boiling point solvent (boiling point of 200-odd degrees C or more) of an electron-donating colorless dye! The Ikuq capsule is placed on the donor side, and activated clay is used in combination with a compound represented by the general formula (where R represents an aryl group or an aralkyl group) as a color developer on the acceptor side. Depending on the arrangement, color development speed, color development once, solidity of the color image (light resistance, water/moisture resistance, lubricant resistance, oxidation resistance, gas resistance, etc.), as well as non-line areas (white background). Stability (persistence of coloring ability,
The present invention has succeeded in providing a pressure-sensitive single sickle material that has significantly improved yellow envy resistance (yellow envy resistance), etc.

The activated clay preferably used in the present invention is produced by lightly to moderately treating acid clay, which is a montmorinite clay mineral, with mineral acids to remove naturally occurring acid-soluble cations such as iron, magnesium, calcium, and aluminum. Although it has been extracted and removed to some extent, it is an anhydrous silicic acid in which a substantial amount of these cations still remains, and the acid strength is picm.
<-3,0, -3,0< pKa <+0.8. +0.
8<pKa<+4.8 (these acid points are affected by the presence of contaminating metal cations), and electron-donating colorless dyes such as crystal violet lactone and benzoyl leucomethylene blue When adsorbed, electrons are exchanged and ionized to produce a colored image. A typical example is activated clay made from Nihon Yu's acid clay, product name Jiruton (1) manufactured by Mizusawa Chemical Industry Co., Ltd.
1 @Manufacturing/Sales 7jAK).

Preferred examples of the rose acid ester compound used in combination with activated clay are as follows.

benzyl batuhydroxybenzoate para-hydroxybenzoic acid ortho-methylbenzyl It can be synthesized by an esterification reaction between para-hydroxybenzoic acid and the corresponding alcohol, and there are many commercially available products.

The microcapsules to be placed in the donor capsule may be manufactured by the omniscient one-icu-four encapsulation method. For example, the coacelvagein method using a combination of +t, -v latin and a polymeric anion, the in-psyche method using a W element-pormaldehyde or metuine-formaldehyde polycondensation reaction, and the in-psyche method using an active hydrogen compound and an infusion reaction. It is sufficient to use a method such as the interfacial reaction using an interfacial reaction with a cyanate compound, and '1ilK@ is not determined.

In the ``C,#@5o-161169 newsletter,
An example is described in which a colored paper (CFa) for pressure-sensitive copying is coated with an alkyl ester of ortho- or para-hydroxybenzoic acid and activated clay. For the 01 paper, crystal violet tactone and benzoyl leucomethylene blue were dissolved in partially hydrogenated terphenyl (which seems to be partially hydrogenated terphenyl, which has lost its aromatic character). We use microcapsules wrapped in paper or cloth.

According to experiments conducted by the present inventors, ortho-hydroxybenzoic acid alkyl esters are generally liquid at room temperature and emit a strong specific odor, so that they are not practical. In addition, when para-hydroxybenzoic iron alkyl ester (and activated clay) is used, para-hydroxybenzoic acid aromatic alcohol ester (and activated clay) is used in the present invention.
The coloring property of the cylindrical resin using the cylindrical resin was particularly superior to that of the CB containing microcapsules containing an aromatic hydrocarbon, a bulky high-boiling solvent (and an electron-donating colorless dye).

In addition, in Japanese Patent Publication No. 48-33209, - as a coloring agent [acid clay and p-phenylphenol or P
= There has been an example in which P'-isopropylidene diphenol (so-called Bisla Sumi Norm) was used in combination, but according to the experiments of the present inventors, not only p-7 Sumi Nil 7 & Nor, but even Bisphenol A has been used. When used in combination with activated clay (CF), yellowing of the white background due to Koen 11 and (among other things) severe yellowing of the white background due to exposure to oxidizing gases in the air (confirmed by NOX gas exposure test) was observed. , was found to be impractical and impractical.

In addition, just to be sure, the inevitable configuration l of the pressure-sensitive recording system of the present invention is
When 11 bottles of I element are used, ■ electron-donating colorless dye and ■
■Microcapsules containing aromatic hydrocarbon medium,
and (2) activated clay, and (0) a para-hydroxybenzoic acid ester compound represented by the above general formula.

Next, preferred embodiments of the present invention will be specifically explained using representative examples. All "parts" hereinafter refer to parts by weight.

Example: Benzyl hydroxybenzoate 100 parts human
xyethyl cellulose 6 parts water
A total of 250 parts per part were ground in a pole grinder for two days.

Mizusawa Chemical Industry ■ 100 parts of activated clay (Product name B: Jiruton M-140) manufactured and sold and the above wet-pulverized para
Dispersion of benzyl hydroxybenzoate [50 parts was dispersed in 200 parts of water containing 1 part of sodium hydroxide, 50 parts of Kt6x oxidized starch, 5 parts of 48X8BR-latex
Add 0 parts and add at and top. and 4F) @@4011
7d (1 cloth so that the dry coating amount is 71/d on D base paper,
A lower (CF) sheet was used (sample symbol B).

For comparative tests, we added methyl para-hydroxybenzoate (i.e., activated clay only as a developer; sample code A) without adding para-hydroxybenzo-penzyl (i.e., only activated clay as a color developer). A CF receipt using the dose of symbol C) or Bis7 & Norm (symbol D) was prepared in the same way.

CB receipt: Crystal Violet Tsukudoor 4 parts Benzoylleucomethylene blue 1 m 5-diethylamino-6-methyl-7-anilinofluorane 0.5 parts Diisoglobilna 7-talene 100s (Kureha Chemical Industry ■Product name manufactured and sold by KMC) The aromatic hydrocarbon high boiling point solvent sn of the electron-donating colorless dye consisting of U.8. P・4.2 B Based on the specification of No. 8,178 [100 m (dry) of microencapsulated melamine melanoma microcapsules, 25 parts of wheat starch, 150 s of a saponified starch 10% aqueous solution, 40 t,
1/df) A doyo (CI) sheet with a dry mms amount of 51/d as a base paper was used.

[Layer each C1 sheet on the obtained CF receipt material (481@) 5 times with one cloth side facing each other [, first apply pressure with a medium pressure calender (nip pressure is in the linear pressure range),
After 1 minute, 1 hour, and 24 hours, 02 side color develops once (#1
As a result, in sample (2) of the combination of the present invention, the linearity after 1 minute was large, which indicates that the This means that it is possible to quickly obtain a copy when written down, indicating that it is very desirable for practical use.

Next, in order to obtain a color image with saturated color density, each CB-CF combination K is subjected to high-pressure calendering (supercalender), and after one day or more, sunlight, humidification,
Various exposure tests to oxidizing gases in the air (using NOx gas) were conducted (Table 2). As a result, in sample (2) of the combination according to the present invention, the decrease in concentration during humidification was particularly small.

Of course, the fastness to sunlight and Not gas was also superior to that of g-grade clay alone, and compared to other soft examples, there was not so much one color.

J11! Medium pressure calendar pressure color development speed and color development once sg table Toughness of high-pressure calender pressurized color image (Survival rate X in parentheses) ・Additional fill 45U, 98NR, H.

- ii* Oxide performance in air: 150ppm+ (test m
(See JIB L-08s8) Next, a single sunlight or single oxide gas exposure test was conducted to examine the deterioration resistance a (stability) of the lower sheet (No. B111).

From Table S, the bottom sheet (2) used for non-invention is:
Deterioration due to light and oxidizing gases in the air is extremely small (meaning that the shelf life of the product is long); on the other hand, when the activated clay of the comparative example and Bis71 Norm were used together (
It was found that sample D) was severely yellowed not only by sunlight but also by NOx gas. In addition, sample A (in which only activated clay was used as a color developer) drastically lost its coloring ability in this exposure test.

Although the details are omitted, the color images of Samples A, B, and CID are stable against plastic softeners, and do not fade even when sandwiched between salt pyfilms containing approximately 30% dioctyl phthalate. However, in the CF receipt made only with an organic acid-based coloring agent, the coloring itself disappeared.

11I3 table (Using a blue filter [reflection density #j constant).

- Soppm oxide: sooppm As stated above, the combination of the donor composition and acceptor composition according to the present invention increases the color development speed.
It was shown that it is an excellent pressure-sensitive recording system that produces solid color images, almost no yellowing of the bottom paper, and a long shelf life.

Claims (1)

[Scope of Claims] Microcapsules containing an aromatic hydrocarbon bulk solvent solution of an electron-donating colorless dye are placed in the donor 111, and activated clay and the following general formula (wherein 8 is an aryl group or an aral group) A pressure-sensitive recording system characterized in that a rose-hydroxybenzoic acid ester compound represented by the following group is used in combination with [-- and is disposed on the acceptor 11 as a coloring agent.