Pressure-sensitive record material

Beginning of patent period · 15 August 1970.

Longest possible duration: May 14, 1986.

The invention relates to pressure-sensitive recording materials in which the formation of colored markers by a reaction between basic chromogenic material and acidic material he follows.

These recording materials include those in which, for example, crystal violet lactone was used as chromogenic substance and attapulgite as acidic clay, for example. In the material described in the parent patent no. 268332 oil-soluble polymers have been used in place of all or part of the clay, which are resistant to desensitization by the action of light and air during storage and due to their solubility in the chromogenic

Substance-dissolving solvents cause a rapid and intense color formation.

Phenolic polymers are particularly well suited for recording materials of the type mentioned, as they may either be coated on a sheet or contained as a solution in microcapsules or otherwise isolated until their reaction with the chromogenic species to form a label on the recording material is desired.

It is well known that one or both of the reactants can be classified in this manner, or that both be arranged as a dry coating for which a suitable solvent is provided in the above-noted manner. It is essential hiebei only that the two reactants must not mix in solution before a reaction is desired. Further, it is well known that the two reactants may be together on a single so-called "autogenous" sheet, or placed on separate surfaces of 20 sheets, thereby yielding a multiple recording material system. The manner in which the chromogenic substance and the acidic substance are arranged is not essential to the invention. Rather, the invention is directed to the color formation system per se and, more particularly, to systems wherein said phenolic polymers are used.

The invention is based on the discovery that polycondensates of formaldehyde with one or more p-substituted phenols, upon reaction in co-solution with suitable chromogenic materials, cause rapid and intense color formation when a high proportion of the phenolic p-substituents attract electron-withdrawing groups. for example, halogen groups. It has also been found that the presence of electron-donating p-substituents in the condensate, eg of alkyl groups, to a greater resistance of the color after its formation as well as a smaller yellowing of the background of the recording material on aging. With knowledge of these facts, it is thus possible to produce better pressure-sensitive recording material systems with which, on the one hand, rapid and intensive color formation can be achieved and on the other hand, both the dyeing and the background remain stable on aging. In all cases, at least 10% by weight of the condensate-forming p-substituted phenols must have electron-attracting p-substituents.

By an electron-attracting p-substituent is meant a substituent having a

Hammet's substituent constant greater than zero, where a substituent with a Hammet's

Substituent constant less than zero is considered electron-donating.

The invention relates to a pressure-sensitive recording material, consisting of a sheet-like material and / or Within the chromogenic substance, phenolic polymer and a liquid solvent for said substances are that react in solution together in the liquid solvent to form a dye, according to Stammpatent no. 268 332, which is characterized in that at least 70 wt. % of the phenolic material consists of oil-soluble poly (vinyl acetate) condensates of formaldehyde and one or more p-substituted phenols, of which at least 10% by weight have an electron-withdrawing p-substituent of the type mentioned, and that each molecule of the polycondensates contains at least three p-substituted phenol units ,

The polycondensates according to the invention contain polymer chains of three or more phenolic units linked with methylene groups and are referred to below as tri and higher condensates, the upper limit of the chain length being determined by the fact that the condensate must be soluble in the oil. Condensates having a chain length of up to twelve phenolic moieties have been found to be useful. Preferably, however, the chain length should be three to six phenolic units.

The formaldehyde content of the condensates ranges from about 0.65 to about 1.0 mole, preferably from about 0.8 to 1.0 mole, of formaldehyde per mole of a mixture of the p-substituted phenols, with the mixture being between about 1 to 5 Mol, preferably 2.0 to 3.5 moles, of phenols with electron-withdrawing p-substituents per mole of phenols with electron-donating p-substituents.

The phenolic polymer used in the recording material of the present invention is phenolic resin containing 75 to 100% by weight of tri- and higher p-substituted phenol / formaldehyde polycondensates, 25 the remaining 0 to 25% by weight consisting of unreacted monomer and dimer. Preferably, the phenolic polymer contains greater than 80% by weight of the tri- and higher condensates because these materials are more readily soluble and give better results than dimer-p-substituted phenol-formaldehyde condensates which are highly crystalline and not readily oil-soluble.

The term oil-soluble used to describe the polycondensates of the present invention indicates that these condensates are soluble in water-immiscible organic solvents to form clear stable solutions, said solvents also being solvents for the basic chromogenic agent to the extent of forming solutions containing at least 0.25 wt %, preferably more than 1% by weight of the basic chromogenic substance.

It is essential to the invention that the aforementioned polycondensates have free or labile (reactive) hydroxyl groups in order to facilitate color formation upon reaction with the basic chromogenic substance.

It must be ensured that a coating containing the phenolic polymer does not stick under normal conditions and that the phenolic polymer containing the condensates is so hard that it can be ground to small particles without this od.ähnl as a result of grinding.

Clumping occurring heat accumulate.

Of the suitable condensates of phenols having an electron attractive p-substituent, p-halophenol condensates are preferred which can be prepared by reacting p-halophenols at temperatures between about -4 and about 100 ° C using acids as catalysts. Any conventional acid can be used to catalyze the condensation. The condensation occurs fairly rapidly in periods of between 30 minutes to about 8 hours and is accompanied by the formation of water and volatiles. It is expedient to remove the water, for example by vacuum distillation. This can be done at intervals or virtually continuously during its formation or even after condensation. Normally, condensation occurs at autogenous pressures and temperatures between about 15 and about 100 ° C in periods of about 30 minutes to about 4 hours.

Suitable inorganic and organic acids as catalysts for the condensation are, for example, hydrochloric acid, hydrobromic acid, sulfuric acid, phosphoric acid, oxalic acid, p-toluenesulfonic acid.

Further phenol condensates used according to the invention can be prepared analogously to the abovementioned p55 halophenols by replacing the p-halophenol by the corresponding p-substituted phenol.

Nr.289149

Examples of electron-withdrawing p-substituent-bearing phenols useful in the preparation of

Polycondensates suitable for use in the recording material of the invention include p-fluorophenol, p-chlorophenol, p-bromophenol, p-iodophenol, p-nitrophenol, p-carboxyphenol, p-carbalkoxyphenols, p-acylphenols and p-aroylphenols p-chlorophenol, which not only gives good results, but is also readily available and economical.

The aforesaid p-substituted phenols give condensates which rapidly develop intense color markings when contacted with basic chromogenic material. As already stated, this is due to the fact that the condensates contain phenol units with electron-withdrawing p-substituents.

Other substituents (electron attracting or electron donating) in one or both of the meta-positions to the phenolic hydroxyl have no further effect. For example, 3-methyl-4-nitro phenol acts like p-nitrophenol, and 3,4-dichlorophenol and 3-methyl-4-chlorophenol both act as p-chlorophenol.

Examples of electron donating p-substituent phenols for preparing polycondensates for use in the preferred embodiment of the invention are as follows:

1. low p-alkoxyphenol;

Second p-Benzylphenol ·

Third any pC - C_ß alkyl phenol,

eg

p-methylphenol, p-ethylphenol, pn-propylphenol, p-isopropylphenol, pn-butylphenol, p-isobutylphenol, p -tertiarybutylphenol, pn-amylphenol, p-isoamylphenol, p-1,1-dimethyl-n-propylphenol, pn-hexylphenol, p-isohexylphenol, p-1,1-dimethyl-n-butylphenol, p-1, '2-dimethyl-n-butylphenol, p-cyclohexylphenol, pn-heptyphenylol, p-isoheptylphenol, p -5,5-dimethyl-n-amylphenol, p-1,1-dimethyl-n-amylphenol, p-octylphenol, p-1,1,3,3-tetramethylbutylphenol, p-isooctylphenol, p -n-nonylphenol, p-isononylphenol, p-1,1,3,3-tetramethylamylphenol,

1 -n-Decyl lphenol, p-Is od ecy lphenol, pn Undecy lphenol, p-Isoundecyl phenol, p -n -Dodecylphenol and isomers of any of the aforementioned p-Cj- to C_J2-Alkylphenole, any two or more of the aforementioned p-alkylphenols containing mixtures and isomers thereof. The addition of meta substituents to the above p-substituted phenols is again without significant effect.

In a preferred embodiment of the invention, the electron-donating p-substituent is

No. 289149 is an alkyl group having 4 to 12, preferably 8 to 9, carbon atoms, while the electron attracting p-substituted phenol is p-chlorophenol. The preferred tri- and higher polycondensate is the

Product of the condensation of p-chlorophenol and p-1,1,3,3-tetramethylbutylphenol with formaldehyde, carried out with an acid catalyst, in the abovementioned molar concentrations.

In the general discussion that follows, phenols and phenol condensates having an electron attracting substituent in the para position in the form of preferred p-halophenols and their condensates will be described. It will be understood that when p-halophenols are mentioned as being suitable for the invention, other members of the group of electron attractive p-substituted phenols would also be suitable.

A feature of the invention is the use of specially adapted for the special purpose Polykondensatmischungen containing p-halophenol-containing tri- and higher condensates and p-alkylphenol containing tri- and higher condensates. By doing so, one obtains recording materials on which an intense color development quickly occurs and both the markings and the background color are permanent. These particular polymer blends contain the tri- and higher p-halophenol / p-Cj-bis described above_J2alkyl-substituted phenol (and / or p-benzylphenol and / or lower p-alkoxyphenol) -formaldehyde polycondensates mixed with at least one free hydroxyl-containing tri- and higher condensate of formaldehyde with a substance selected from pC to C ₂alkyl-substituted phenol, p-benzylphenol and lower p-alkoxyphenol, the p-halophenol condensates constituting between 10 and 35% by weight of this mixture, while the latter condensate contains between 65 and 90% by weight of said specific mixture of tris and higher polycondensates.

The latter condensate is also normally formed with acid as a catalyst in the same manner and under the same general conditions as described above with respect to the p-halophenol condensates. To the suitable for the preparation of this condensate ρ-Ο_χ- to C_J2 alkyl-substituted phenols include any of those mentioned in the foregoing p -C - to C_ualkyl-substituted phenols which have been mentioned in connection with the suitable for the formation of the aforementioned p-halophenol condensates. In the same way, instead of p-benzylphenol or a single pC-bis-alkyl-substituted phenol, mixtures of any two or more of such substances including a p-cycloalkylphenol can be reacted with formaldehyde. In addition, the latter condensate component of the particular mixture may consist of a number of individual condensates of formaldehyde with pC to C alkyl substituted phenol, p-benzylphenol and lower p-alkoxyphenol.

According to a preferred embodiment of the invention, the special mixture of condensates from about 20 to about 30 wt.% Of the aforementioned p-halophenol-containing condensate sats and about 70 to 80 wt -.% Of the latter condensate, of which a part, preferably a large part (on a molar basis), pt-butylphenol. This special condensate mixture is preferred for paper-based recording materials.

The following examples describe various phenol condensates and condensate mixtures as well as the test results obtained with them.

A suitable method for preparing recipe guidelines is the titration of condensates in benzene solution with non-aqueous base such as tetramethylguanidine to the ethyl bis (2,4-dinitrophenyl) acetate endpoint. Mixtures of condensates can be arbitrarily prepared to give titration values ​​equivalent to the value obtained by titration of any standard phenol / formaldehyde condensate chosen for its convenient color development properties. Mixtures adapted to the desired standard can be expected to provide the same standard performance in developing color along with basic chromogenic materials on paper. Such titrations may therefore be used to select a number of condensate mixtures for testing according to the product-oriented test results given in the examples. As the titration standard for the mixed resin condensates of the invention, generally, p-phenylphenol-formaldehyde resin (having a Hammett's substituent constant of about zero for a p-phenyl substituent) was used.

The p-halophenol condensates and specific mixtures of condensates containing them produce visible strong colouration upon reaction in solution with basic chromogenic material. Normally, the chromogenic compound or chromogenic substance is colorless to slightly tinted before the reaction. However, the chromogenic substance should be able to change color so that it shows a very clear color when it comes in solution contact with the aforementioned p-halophenol-containing condensates and special condensate mixtures. These combinations of chromogenic material and the aforementioned condensates, as well as specific condensate mixtures, can be used in any of the known color-producing or label-forming recording media systems in which the chromogenic substance is basic and the complementary color-producing component is acidic.

Examples of suitable basic chromogenic compounds having chromogenic groups are diaryl phthalides, for example 3,3-bis (p-dimethylaminophenyl) -6-dimethylaminophthalide (crystal yliolactone, in the following abbreviated to KVL) and 3,3-bis- (p-dimethylaminophenyl) - phthalide (malachite green lactone, hereinafter referred to as MGL); Leucauramines, eg, N-halophenyl, especially N- (2,5-dichlorophenyl) -yl-leucine amine; Acylauramines, eg N-benzoylauramine and N-acetylauramine; Arylauramines (eg N-phenylauramine); α, β-unsaturated aryl ketones, eg, dianisylideneacetone, dibenzylideneacetone and anisylideneacetone; basic monoazo dyes, e.g., p-dimethylaminoazobenzene-o-carboxylic acid (methyl red), 4-aminoazobenzene (yellow oil AAB), and 4-phenylazo-1-naphthalenamine; Rhodamine B-lactams, eg N- (p-nitrophenyl) rhodamine B-lactam (hereinafter called RBL); Polyarylcarbinols, eg bis (p15 dimethylaminophenyl) methanol, called Michler's Hydrol, Crystal Violet Carbinol and Malachite Green Carbinol; and 8'-methoxybenzoindolinospiropyrans, eg, 8'-methoxybenzoindolinospiropyran, 4,7,8'-trimethoxybenzoindoiinospiropyran, and 6'-chloro-8'-methoxybenzoindolinospiropyran, as well as p-dimethylaminostyrylquinoline. As the basic chromogenic agent, any two or more of them may also be used mixtures containing the aforementioned basic chromogenic color former can be used.

In order to obtain optimum properties of the recording material of the present invention, it is essential that the phenol condensates and mixtures thereof and the basic chromogenic substance are collectively soluble in a solvent, preferably in the oil or solvents, causing the color forming reaction in the recording material. A convenient and preferred way to provide the recording material with the solvent or oil is to encapsulate a solvent or oil solution of at least one of the color formers, eg, the basic chromogenic material, by the known microencapsulation technique and the capsules onto the paper or other support apply or incorporate into this, so that when releasing the solvent (eg by the pressure used to form the label) at least one of the color-forming components has already been practically dissolved by the solvent or oil, whereby color formation is still accelerated when the other color former mixes with the solution. It is also within the scope of the invention to encapsulate separate solutions of the chromogenic substance and the condensates reacting with them and anzuenen the separately encapsulated solutions in or on the recording material NEN. Another, but somewhat less convenient, option is to encapsulate only the solvent so that upon release, it dissolves both color formers. Numerous types of capsules for this purpose are well known in the art.

The solvent should be capable of dissolving at least 1.0% by weight of the basic chromogenic agent and a corresponding concentration of the aforementioned p-halophenol-containing condensates or specific mixtures thereof. In preferred systems, the liquid solvent is capable of dissolving more polycondensate than required to optimally utilize the basic chromogenic

Substance and thus to ensure maximum color intensity at the reaction sites. For best results, the combination of the common solvent and the color former should be such that the solvent dissolves both color formers within about 15 seconds after release of the solvent from the capsule. Suitable solvents include the following:

Volatile and non-volatile hydrocarbons and halogenated hydrocarbons include aryl hydrocarbons, eg. Benzene, toluene and xylene; halogenated aliphatic hydrocarbons, eg perchlorethylene; chlorinated polyphenols, eg chlorinated diphenyls; and aromatic and / or halogenated aromatic petroleum distillates, for example those having a boiling point between about 135 and 260 ° C, consisting predominantly of aromatic and / or halogenated mono- or polycyclic aromatic components, but also minor amounts of C₅* C_{2 (|} Paraffins can keep 50.

Suitable supports for the novel recording material include paper sheets, woven or nonwoven webs, and webs containing paper fibers blended with other materials (eg, natural and / or synthetic textile fibers), as well as polymer matrices, films, sheets, and layers.

The capsules containing the liquid solvents in which optionally one of the color reaction components is dissolved may be coated onto the support or sheet (eg paper)

Nr.289149

- 6 are applied or incorporated during the production of the web or sheet in this or this.

As already stated, the solvent and both color formers may be present in the same paper sheet or web. This type of recording medium may then be said to be autogenic, since both color-reaction components and the agent (s) providing the intimate mixture thereof are contained in the same sheet or web. It will be understood that the solvent is held in capsules or otherwise to ensure that the essential color reaction components can not come into contact until label formation is desired. In such recording materials, the capsules containing the chromogenic solution and the p-halophenol-containing aforementioned condensates (or specific condensate mixtures) can be evenly distributed on the paper web or sheet so that a large number of uniformly distributed microcapsules are intimately associated with the aforementioned condensates is present within the paper carrier or the matrix.

The abovementioned special condensate mixtures can be applied to a paper web by means of a multiplicity of conventional coating or impregnation methods or they can be impregnated with them, for example by applying a solution, dispersion or suspension. It is further within the scope of the invention to use inert fillers and / or fillers, such as acidic inorganic clays, which react with the basic chromogenic substance to form color. Also, the aforementioned condensates may be applied to the paper sheet or web by dry coating techniques well known to those skilled in the art of coating. When using dispersion od.ähnl. In the coating process, the dispersant is normally water or predominantly aqueous and the aforementioned condensates and condensate mixtures are ground or comminuted to a particle size suitable for application and uniform dispersion and / or incorporation into the paper support or matrix. Normally, this particle size is between about 0.1 and about 5 gm, with most of the particles having a size of less than 2 gm. The preferred particle diameter is 2 gm and less. While the condensates are usually uniformly deposited on or incorporated into the paper support or matrix, it is also within the scope of the invention to make this coating or incorporation only in particular areas or parts, which color reaction can then only take place in them.

Even very small amounts of the two essential color formers give colored markings when brought into contact with one another in the presence of an oil (solvent). However, to obtain adequate coloration in recording materials, the amounts mentioned below are used. The following table shows the concentrations of the essential color formers in g / m.sup.2 of the respective carrier.

<td>Essential color formers</td><td>Useful concentration g / m²</td><td>Usual concentration g / m²</td><td>Preferred concentration g / m²</td>

<td>A. Encapsulated Chromogenic Material ·)</td><td>0.03 - 0.12</td><td>0.03 - 0.11</td><td>0.045-0.09</td>

<td>B. At least 700 wt. Tri- and higher condensates containing phenolic resin</td><td>0.11 -3.7</td><td>0.15 - 1.5</td><td>0.45 - 1.2</td>

*) (The concentrations given are for the encapsulated chromogenic substance per se.) The weight concentration of the encapsulated solution of the active chromogenic substance including solvent and capsule wall forming material may be between 0.15 and 15 g / m² lie. Usually it is between

1.5 and 7.5 g / m², preferably between 3 and 4.5 g / m²).

No. 289 149

Arrangement and state of the color formers are the same as in known recording materials.

In the following examples, the invention is explained in more detail, but should not be limited by these. Unless otherwise stated, all parts and concentrations are by weight and by weight.

Example 1: This example describes the preparation of typical p-halophenol and pC₁^- to C_J2 alkyl-substituted phenol-formaldehyde condensate for use in the recording material of the present invention.

196 g of p-chlorophenol, 104 g of p, 1,3,3-tetramethylbutylphenol, 130 g of a commercially available 37% by weight are added to a reaction vessel (plastic glass bottle). -% aqueous solution of formaldehyde (formalin) and 10 cm? conc. Hydrochloric acid as catalyst. The reactants are condensed at reflux temperatures for 4 hours in the art glass bottle at autogenous pressures. Then the resulting condensate is cooled and the upper aqueous layer removed. The still water of reaction containing condensate is vacuum-distilled at temperatures between room temperature and 200 ° C with a partial vacuum generated by a water jet pump to remove most of the water and the volatiles. Then, the condensate is heated to about 200 ° C and held at this temperature for 15 minutes, after which it is poured into a suitable container by allowing it to cure with the gradual decrease in temperature to room temperature.

An analysis to prove the elements C, H, Cl and O gave the following values:

Carbon 66.5%,

Hydrogen 5.8%,

Chlorine 16.2% and

Oxygen 11.5% compared to the theoretically determined values ​​for the tetramer condensate:

Carbon 67.5%,

Hydrogen 5.9%,

Chlorine 16.9% and

Oxygen 10.0%.

When determining the infrared adsorption patterns, this condensate showed adsorption in the range of 3,200 to 3,500 cm¹ (indicating the free hydroxyl groups) and no adsorption in the range of 1600 to 1700 cm '¹ (If adsorption were present here, it would indicate desensitization of the hydroxyl groups).

Example 2 · (Various p-halophenol and pC to C 1-4 alkyl substituents.)

<td>Execution example</td><td>ingredients</td><td>Color intensity of the mark *)</td>

<td>A</td><td>p-Chlorophenol p -1,1,3,3-tetramethylbutylphenol 37 wt. -% aqueous solution of formaldehyde</td><td>38</td>

<td>B</td><td>p-fluorophenol p -1,1,3,3-tetramethylbutylphenol 37 wt. -% aqueous solution of formaldehyde</td><td>42</td>

<td>C</td><td>p-Bromophenol ρ -1,1,3,3-tetramethylbutylphenol 37 wt. -% aqueous solution of formaldehyde</td><td>43</td>

<td>D</td><td>p-iodine ophenol p -1,1,3,3-tetramethylbutylphenol 37 wt. -% aqueous solution of formaldehyde</td><td>43</td>

No 289149 (continued)

<td>execution example</td><td>ingredients</td><td>Color intensity of the mark *)</td>

<td>e</td><td>p-chlorophenol p-methylphenol 37 wt. -% aqueous solution of formaldehyde</td><td>38</td>

<td>F</td><td>p-Chlorophenol p -Tertiärbutylphenol 37 wt. -% aqueous solution of formaldehyde</td><td>41</td>

<td>G</td><td>p-Chlorophenol p-dodecylphenol 37 wt. -% aqueous solution of formaldehyde</td><td>41</td>

*) (The color intensity test is a comparative evaluation of the ability of each condensate to produce a blue color on contact with a benzene solution containing 0.5% by weight of crystal violet lactone (KVL).) This test is carried out as follows:

It is a 0.5 wt. - Prepares% solution of the test resin using reagent benzene as a solvent. To obtain a clear solution, it may be filtered if necessary. There is a comparable 0.5 wt. -% solution of KVL in benzene prepares, of the 5 cm³to 100 cnf of the condensate solution are added. The solutions are shaken thoroughly so that the color formers come in good contact with each other. Using a pipette, apply 3 drops of this solution to a round white filter paper (brand Blue Ribbon no.589, diameter 15 cm, manufactured by Schleicher &amp; Schüll). It forms a colored spot with a size of about 3.2 to about 3.8 cm in diameter. On each filter paper, five such spots are produced. After allowing 10 minutes for the evaporation of the solvent and the further development of the color spots, the reflectance of the color spots and the white background are read in a conventional manner using a Bausch &amp; Lomb opacimeter. The color intensity (percentage of the reflection ratio) is then calculated according to the following equation:

Reflection algebra of the color patch

Reflectance of the background

The values ​​given are average values ​​for the five color patches. The lower color intensity values ​​indicate the generation of a more intense blue color.)

Numerous water-insoluble, solvent-soluble p-halophenol and pC to C alkyl substituted phenolaldehyde condensates having the foregoing ingredients were prepared. For this purpose, a two-part art glass container with a capacity 5 of 200 cm was used³whose lid had four orifices, one of which was for the reflux condenser, one for the stirrer, one for the addition of reagents, and one for a thermometer. Heat was supplied by means of a glass fiber electric heater adapted to the lower part of the vessel. The condensates were prepared and recovered by the following typical procedure for each embodiment:

The p-halophenol (0.3 mol) and the p-alkylphenol (0.1 mol) were added to the reaction vessel at a molar ratio of 3: 1 and heated to melt. Then, as many as 37 wt. % aqueous solution of formaldehyde to give 0.32 mol of formaldehyde, the acid catalyst (from 2.5 to 4 cm³ conc. Hydrochloric acid) and water (about 10 cm³) the molten

No. 289149 phenols added (mol ratio of formaldehyde to the total amount of substituted phenols, ie

p-halo plus alkylphenols, 0.8: 1). The temperature in the vessel was increased until the vapor line was at the bottom of the reflux condenser. The reaction mixture was stirred for 3 to 4 hours and the

Refluxed. Then stopped stirring, so they sit down and in two

Layers. The upper aqueous layer was then decanted. The reflux condenser was removed and the reaction vessel was equipped with a distillation apparatus to remove water and other volatiles from the condensate. After this was done, the temperature in the vessel was gradually increased from 120 to 150 ° C and higher until no more water could be observed. Then the condensate was placed in suitable containers (e.g. Aluminum shells) to cool to room temperature (about 18 to 24 ° C) poured. This gave a hard and brittle thermoplastic material.

In the production and isolation of the condensate in the embodiment C, an additional purification step was carried out. After pouring the condensate from the reaction vessel into the appro priate container, it was allowed to harden and then grind it using mortar and pestle to a fine powder. The crushed condensate was in 500 cm³ Water dispersed and with 100 cm³ Benzene extracted from the water. The benzene layer was then in turn twice with 200 to 300 cm³ Extracted water. Finally, the benzene was evaporated by drying at room temperature under reduced pressure in a vacuum separator to leave a solid condensate.

The condensates of the embodiments A to G produced an instant blue color when contacted with a benzene solution of KVL. Each of these condensates immediately gives a blue mark when normal marking pressure is exerted on a pair of sheets of paper, one of which is coated on the upper side with the condensates as a recording sheet and this page is directly underlaid by another sheet of paper whose back or underside is coated with a benzene solution of KVL-containing gelatin capsules. The marking pressure is exerted on top of the latter sheet, for example by a pen, pen, pencil, typewriter type, or other similar pressure-generating marking device.

Example 3:

<td>Execution example</td><td>Substituted phenol component (s)</td><td>Molar ratio halo -.- alkylphenol</td><td>Mol Ratio of formaldehyde: phenol (s)</td><td>Color intensity of the mark</td><td>color description constantly</td>

<td>A</td><td>p-Chlorophenol</td><td>-</td><td>0.8: 1</td><td>38</td><td>Yes</td>

<td>B</td><td>p-Chlorophenol plus p-1,1,3,3-tetramethylbutylphenol</td><td>5: 1</td><td>0.8: 1</td><td>37</td><td>Yes</td>

<td>C</td><td>p-Chlorophenol plus p-1,1,3,3-tetramethylbenzene phenol</td><td>3: 1</td><td>0.8: 1</td><td>38</td><td>Yes</td>

<td>D</td><td>p-Chlorophenol plus p-1,1,3,3-tetramethylbenzene phenol</td><td>2: 1</td><td>0.8; 1</td><td>37</td><td>Yes</td>

<td>e</td><td>p-chlorophenol plus p-1,1,3,3-tetramethylbenzene phenol</td><td>1: 1</td><td>0.8; 1</td><td>42</td><td>Yes</td>

By means of the method described in Example 2, numerous tri - and higher p-halophenol-containing condensates were prepared with formaldehyde, hydrochloric acid being the catalyst, a 36 wt. -% aqueous solution of formaldehyde and the above-mentioned p-substi10

No. 289149 used phenols. In the embodiments A to E, the molar ratio of p-halophenol to p-Cj to C was_l2Alkyl-substituted phenol between only p-halophenol in the embodiment A and equal amounts of both substituted phenol components in the embodiment E, while the

Molar ratio of formaldehyde to the total amount of substituted phenol was kept constant.

The condensates were then tested for color intensity (as in Example 2) and resistance of the label, u.zw. from the point of view of their practical use in paper recording media exposed for two weeks to ambient temperatures, humidity and atmospheric influences (air). Color intensity values ​​between 33 and 43 are considered useful.

Example 4;

<td>execution example</td><td>Substituted phenol component (s)</td><td>molar ratio Alkyl; halo- phenol</td><td>molar ratio Formaldehyde; Phenol (e)</td><td>Color intensity of the mark</td>

<td>A</td><td>p-chlorophenol plus p-1,1,3,3-tetra-methyl-butylphenol</td><td>3: 1</td><td>0.65: 1</td><td>34</td>

<td>B</td><td>p-chlorophenol plus p-1,1,3,3-tetramethylbenzene phenol</td><td>3: 1</td><td>0.7: 1</td><td>41</td>

<td>C</td><td>p-chlorophenol plus p-1,1,3,3-tetramethylbutylphenol</td><td>3: 1</td><td>0.8: 1</td><td>38</td>

<td>D</td><td>p-chlorophenol plus p-1,1,3,3-tetramethylbenzene phenol</td><td>3: 1</td><td>1: 1</td><td>40</td>

<td>e</td><td>p-chlorophenol plus p-1,1,3,3-tetra-methyl-butylphenol</td><td>3: 1</td><td>i.2: i</td><td>45</td>

Analogously to Example 2, a series of tri- and higher p-halophenol-p-octylphenol / formaldehyde condensates was prepared. The molar ratio of p-halophenol to p-alkylphenol was kept constant while the molar ratio of formaldehyde to the total amount of p-substituted phenols was varied to determine the effect on the color intensity of the label. As is apparent from the above Table her15, the use of condensates having a molar ratio of formaldehyde to the total amount of the p-substituted phenol of greater than 1: 1 (eg, in the embodiment E) leads to insufficient color intensity in paper recording media.

It has also been found that the use of low formaldehyde (eg, less than about 0.65 moles of formaldehyde per mole total of the p-substituted phenol) also results in insufficient color generation (eg, decreased reactivity of the resulting condensates with the basic chromogenic compounds). The use of too little formaldehyde also causes difficulties in producing coatings from the condensates when applied by conventional aqueous dispersion coating processes, particularly with respect to grinding of the condensates and loss of condensate due to its water solubility.

Example 5; The following are the results of color intensity tests demonstrating the effectiveness of tri- and higher phenol / formaldehyde condensates with various electron-attracting p-substituted phenol moieties, p -halophenol resins (m -unsubstituted), which are also representative of this group, as in the other examples treated.

Nr.289149

<td>Substituted Phenol component (s)</td><td>Color intensity of the mark</td>

<td>3,4-dichlorophenol</td><td>35.4</td>

<td>3,4-dichlorophenol plus p-octylphenol (mole ratio 1: 1)</td><td>41.5</td>

<td>Propyl p-hydroxybenzoate plus p-octylphenol (molar ratio 3: 1)</td><td>50.7</td>

<td>p -hydroxybenzophenone</td><td>55.4</td>

<td>p-hydroxybenzophenone plus p-octylphenol (mol ratio 1: 1)</td><td>54.3</td>

<td>3-methyl-4-nitrophenol plus p-octylphenol (molar ratio 2; 1)</td><td>39.9</td>

<td>3-methyl-4-nitrophenol plus p-octylphenol (mol ratio 1: 2)</td><td>45.9</td>

<td>p-hydroxypropiophenone plus p-octylphenol (molar ratio 2 · x 1)</td><td>53.1</td>

The molar ratio of formaldehyde to p-substituted phenol (s) was 0.8: 1 in all of the aforementioned resins.

In comparison, tri- and higher condensates (having the same molar ratio of formaldehyde to phenol of 0.8; 1) prepared from formaldehyde and various electron-donating p-substituted phenols gave the following color intensities of the label;

p -nonylphenol resin 65.9;

p-amylphenol resin 67.5;

p-octylphenol resin and 58.7; p-cyclohexane phenolic resin 64.9.

The standard p-phenylphenol resin prepared in the same manner gave a color intensity of the label of 45.1.

Example 6; This example deals with the typical preparation of recording material using a support sheet of paper and various tri-and higher condensates containing p-halophenol, as well as specific blends thereof.

The color-forming condensates and condensate mixtures mentioned in the further course of the example were prepared with the stated constituents in the stated molar ratios by the condensation process described in Example 2 with acid as catalyst. In all cases, the other constituent of the condensate was formaldehyde in 37 wt. -% aqueous solution. Mixtures of condensates were prepared by separately condensing the respective condensates and then mixing them prior to milling and other steps to make the coating. The overall procedure contained four main stages:

The preparation of the condensate (and optionally the mixture of condensates); the grinding of the condensates;

the preparation of the aqueous dispersion which is applied as a coating; the orders of the coating.

The typical procedures given below for milling, coating, and coating apply to the preparation of a 17 wt. -% condensate (s) containing coating. It will be understood, however, that coatings containing less condensate have the concentrations of substances listed in the table.

To grind the condensate, 1700 g of condensate and 1700 g of water and 204 g of a 25 wt. % aqueous solution of a dispersant, which is a commercially available sodium salt of a condensed, sulfonated organic acid, into a grinder having a capacity of about 7.5 liters and about two-thirds stainless steel balls having a diameter of about

No. 289149 mm is filled. The grinding process takes about 180 revolutions per minute for 75 to 90 minutes.

Then, the coating composition is prepared by dispersing 5500 g of kaolin, 900 to 1200 g of calcium carbonate and optionally 300 g of commercially available silica gel in about 6000 g of water with a dissolver or other suitable high speed stirrer. Dispersants, eg, tetrasodium phosphate, may be used in conventional amounts to facilitate the formation of the desired smooth, lump-free dispersion for the coating. As soon as the abovementioned components are sufficiently dispersed, 4240 g of the ground condensate are added. Then, with stirring, adding 4750 g of an aqueous dispersion containing 20% ​​solids of commercially available Hydroxyäthylmaisstärkeäthern medium 10 viscosity along with 1300 g of a 50% solids containing, commercially available carboxyZierten styrene butadiene latex. Prior to use, the coating composition is passed through a 100 mesh screen.

The above-described screen-passed coating compositions are then applied to conventional white fine paper (for example, 80% by weight kraft fibers and 200% by weight 15 sulfite fibers) having a basis weight of about 50 g / m² in an amount of about 6 g / m² applied. This can be done by any of the conventional methods, for example by rolling, painting or by means of an air brush, the aqueous dispersion of the coating having the following solids content:

When rolled or painted, 48 to 55% by weight, when applied with an air brush, 28 to 32% by weight.

&gt; The coated paper sheets were then air dried and subjected to several tests to determine their usefulness as recording transfer materials. The final coatings contain the following solids-based ingredients:

<td>component</td><td>Parts by weight (in g)</td><td>% By weight</td>

<td>Condensate (s)</td><td>1700</td><td>17.0</td>

<td>calcium carbonate</td><td>900 - 1200</td><td>9.0 - 12.0</td>

<td>dispersant</td><td>51</td><td>0.5</td>

<td>silica gel</td><td>300 (if used)</td><td>0.0-3.0</td>

<td>kaolin</td><td>5450</td><td>54.5</td>

<td>styrene-butadiene latex</td><td>650</td><td>6.5</td>

<td>starch ethers</td><td>950</td><td>9.5</td>

The respective different phenolic resins in their coating containing sheets are each subjected to two tests (once with respect to the color intensity of the pressure achieved by a typewriter and on the other with respect to its color fastness) and comparatively evaluated, the worst product rating 7 and the best product rating for each of the tests.

To test the color intensity of the typewriter writing, the condensate-coated paper sheet was placed coated side up under a paper sheet whose underside was coated with a solution of basic chromogenic substance-containing capsules. Under the sheet coated with the condensate, two uncoated fine paper sheets were placed as a base. The recording material set was introduced into a typewriter and six each about

7.5 cm long rows of characters printed. Then, the color intensity of the labeled part (I) and that of the unlabelled background (I._O) read. The specific color intensity of the typewriter font was obtained by passing I through I_O shared.

For the color fastness test, sheets in which the capsules were broken and colored markers caused by typewriter strokes were exposed to normal environmental conditions for three weeks with the test patterns attached to a wall. The aforementioned measurements of Γ and I "with the opacimeter were made before and after the said three weeks. The reduction of the color intensity of the marks within the period of three weeks indicates the extent of fading or color fastness.

The corresponding results are shown in the following table:

Nr.289149

<td>execution example</td><td>Condensate (s)</td><td>Color intensity of the Schreibma - schin pressure</td><td>Color fastness</td>

<td>A</td><td>p-chlorophenol / formaldehyde</td><td>1</td><td>1</td>

<td>B</td><td>Condensate of formaldehyde and a mixture of p-chlorophenol or p-1,1,3,3-tetra methylbutylphenol in a molar ratio of 3: 1</td><td>2</td><td>2</td>

<td>C</td><td>Condensate of formaldehyde and a mixture of the p-substituted phenols of the embodiment B in a molar ratio of 2: 1</td><td>3</td><td>3</td>

<td>D</td><td>Condensate of formaldehyde and a mixture of the p-substituted phenols of the embodiment B in a molar ratio of 1: 1</td><td>4</td><td>4</td>

<td>e</td><td>p -t-butylphenol / formaldehyde</td><td>5</td><td>5</td>

<td>F</td><td>p -1,1,3,3-tetramethylbutyl phenol / formaldehyde</td><td>6</td><td>6</td>

The goal of producing a high quality recording material with a well-balanced combination of advantageous properties is to achieve optimum intensity of typewriter printing and color fastness without seriously affecting yellowing resistance and printing speed. While ink color intensity and color fastness measurements appear to require the use of p-halophenol formaldehyde condensates alone, p-alkyl-substituted phenolaldehyde condensates provide increased resistance to yellowing and print speed, ie, the rate at which the post-break pressure No matter how long the recording material was previously stored, it does not slow down. Also, p-alkylphenols are more economical than p-halophenols because they are cheaper.

Example 7: This example deals with the preparation of a colorant transfer base paper coating using a tri- and higher condensate of formaldehyde and p-chlorophenol mixed with a tri and higher condensate of formaldehyde and a pC_Galkyl-substituted phenol. Of course, this condensate mixture can also be used for so-called autogenous recording materials.

340 g of a tri- and higher condensate of formaldehyde and p-chlorophenol, 1360 g of a tri- and higher condensate of formaldehyde and p-1,1,4,4-tetramethylbutylphenol, 1700 g of water and 204 g of a 25 wt. -% Aqueous solution of the dispersant used in Example 6 in a grinder with a capacity of about 7.5 1, which was about two-thirds filled with stainless steel balls with a diameter of about 3 mm. The aqueous mixture was ground for 75 to 90 minutes at a speed of 180 rpm.

Then, 5,500 g of kaolin, 900 to 1,200 g of calcium carbonate and 300 g of silica gel were dispersed in about 6,000 g of water with a dissolver or other suitable high speed stirrer. Dispersants, eg, tetrasodium phosphate, may be used, if desired, to obtain smooth, lump-free coatings.

After good dispersion, the alumina-containing dispersion 4240 g of the ground tri- and higher condensate mixture was added together with 4 750 g of a 20 wt. -% aqueous solution of corn starch ethers and 1300g Styrolbutadienlatex (solids content 50%), as used in Example 6, with constant stirring. Then the coating composition was applied to paper in the manner described in Example 6.

Example 8: Here is the typical preparation of so-called autogenous recording materials

No. 289,149, in which both the basic chromogenic substance and the tri- and higher p-substituted phenol formaldehyde condensate (s) reacting therewith are arranged on the same side of the same sheet. Basically, in this method, a previously enclosed in microcapsules solution of the basic chromogenic substance-containing coating on the

Paper deposited, after which a or the condensates containing further coating is applied. Suitable encapsulation techniques are well known in the art and will not be discussed further herein.

<td colspan="2">Lower class</td>

<td>ingredients</td><td>Parts by weight</td>

<td>17.5% by weight of encapsulated KVL solution (as in Technique known) containing aqueous dispersion</td><td>296</td>

<td>Calcined kaolin</td><td>25</td>

<td>Purified wood cellulose fibers (microfine)</td><td>8.8</td>

<td>Talcum in medium particle size (100% passes through 375 mesh sieve)</td><td>3.7</td>

<td>Äthylated cornstarch of medium viscosity</td><td>38.5</td>

<td>water</td><td>28</td>

The ingredients listed above are mixed at high speed for 5 minutes in a 10-blender or colloid mill. This gives a coating composition having a solids content of 25 wt.%, Which by means of an air brush or a Meyer rod in an amount of

7.2 to 7.5 g / m² is applied to the paper support.

<td colspan="2">Upper layer</td>

<td>ingredients</td><td>Parts by weight</td>

<td>condensate</td><td>140</td>

<td>water</td><td>703</td>

<td>Gum arabic</td><td>10</td>

<td>kaolin</td><td>590</td>

<td>Calcined kaolin</td><td>120</td>

<td>Aqueous, etherified cornstarch</td><td></td>

<td>(Solids content 20%)</td><td>400</td>

<td>Carboxylated styrene butadiene latex</td><td>120</td>

This upper layer is prepared by grinding 140 g of resin condensate (e), 183 g of water and 15 g of gum arabic in a suitable size size grinding device filled with stainless steel balls for 1 h or until an average particle size of less than pm, eg between 1 and 3 pm, depending on the conventional light transmission measurements.

Then, the above 590 g of kaolin, 120 g of calcined kaolin and 520 g of water are added to a mixer or other suitable high-speed agitator and mixed until the clays are well dispersed. Then, 333 g of the ground-prepared resin dispersion prepared in the manner described above, which is intimately mixed with the toner dispersion, is added. Thereafter, 400 g of the 20% etherified corn starch are added with constant stirring, followed by the addition of 120 g of the carboxylated styrene-butadiene latex.

The upper layer having a solids content of 30% is then applied to the paper already provided with the lower layer in an amount of 6.2 ± 0.3 g / m² by means of an air brush or a

No. 289 149 suitable applicator bar applied. After drying, the autogenous paper sheets become one

Subjected to color intensity test by typewriter printing and rated 1 to 4, with rating 1 indicating the best and rating 4 the worst quality.

This test is performed as follows:

An autogenous paper sheet is coated with two uncoated paper sheets (22 g / m²) and put a paper sheet of this kind over. By means of a typewriter, the autogenous sheet is printed by breaking the capsule coating with colored characters and the color intensity of the print on the autogenous sheet is then determined as in Example 6.

The results of the test below show the effect of using various condensates in the top layer of the autogenous recording paper.

<td>Execution example</td><td>Condensate (s)</td><td>Color intensity of typewriter printing</td>

<td>A</td><td>p -1,1,3,3-tetramethylbutylphenol / formaldehyde</td><td>4</td>

<td>B</td><td>p -t-butylphenol / formaldehyde condensate</td><td>3</td>

<td>C</td><td>Condensate of formaldehyde and a mixture of p-chlorophenol and p-1,1,3,3-tetramethyl butylphenol in the molar ratio 3: 1</td><td>1</td>

<td>D</td><td>Mixture containing 80% by weight -% Condensate of formaldehyde and p-butylphenol and 20% by weight Condensate of formaldehyde and a mixture of p-chlorophenol or a mixture of pChlorophenol and p -1,1,3,3 -Te tramethylbutylphenol in the molar ratio 3: 1</td><td>2</td>