DE2039931B2 - Leuco printing ink for stencil or stencil duplication printing processes - Google Patents

Description

2. leuco printing ink according to claim 1, characterized by dye precursors and an aid for issuing characterized in that the chlorinated η-paraffin of good printability, for example a wax, Contains 8 to 26 carbon atoms. Fat or oil or a synthetic hoclimolecular

3. leuco printing ink according to claim 1 or 2, ao compound. The one in these solvents characterized in that the chlorinated dissolved dye precursor gives a deep color in η-paraffin with one of the auxiliary solvents flüs- contact with a clay-coated paper, however Sigen paraffins, silicone oils and / or alkyl, a dye precursor dispersed therein does not produce any benzene is mixed. deep color, even in contact with a tonal

»5 pulled paper. Therefore the matrix or stencil printing ink containing the dye precursor as a coloring component from the common known printing inks from pigment

The invention relates to a suspension-type leuco printing ink for stencil or matrix printing Stencil or stencil duplication printing 30 in view of the fact that the dye precursor is in travel. the carrier material must be dissolved.

So far, as known solvents in Ma- As examples of dye precursors in the frame

Trizen or stencil or screen printing inks, the invention are leuco derivatives of dyes which contain a colorless dye precursor, such as leuco crystal violet or leucomethylene blue, for example chlorinated diphenyl, castor oil, linseed lactone derivatives of dyes, such as crystal violet oil, phthalic acid esters, u. used. It is also lactone, lactam derivatives of dyes, such as Rhod, that the most effective solvent consists of chloramine-B-lactam and spiro compounds such as 3-merated diphenyl (cf. DT-AS 1 812 380, thyl-2,2 ' -spirobi (benzo [f] -chromen) listed.
DT-AS 1 247 348, DT-AS 1275 550, GB-PS 852 131 Preferred examples of solvents for these

and U.S. Patent 3,104,980). 40 dye precursors include chlorinated n-paraffins,

However, this chlorinated diphenyl is more than 0.5 percent by weight, based on the agent for printing inks, which dissolve and ren in amateur printing solvents, of the dye precursor, for example in screen printing processes, to a rapid color formation speed because develop it in the stenciled or matte-coated paper,
Trizenbogen for the typewriter penetrates and 45 The chlorinated η-paraffins are generally colorless in addition, an intrusive odor and toxic or pale yellowish and known not to be toxic. Has properties, unfavorable. The solubility of the dye precursors in the chlorine therefore desires to replace these harmful, toxic solvents with more suitable ones as they increase. the chlorination (percent by weight of chlorine). So can

From the DT-AS 1 226 610, the DT-AS 1191 836 50 z. B. a chlorinated η-paraffin, which consists of an n-par- and DT-PS 853 291 it was also known to have 12 to 14 carbon atoms with an affinity Chlorination products as a binder for printing ink chlorination to 50% consists of using more than 6 weights. According to this prior art, percent of the dye precursor, for example however, no colorless dye precursors 3-methyl-2,2'-spiro (benzo [f] -chromene) were used at habitual. 55 licher temperature, but an equal n-par-

According to the invention it has now been found that afftu, which is 20% chlorinated, can only

chlorinated η-paraffins very effectively as a solvent 1.5 percent by weight of this dye precursor

for a printing ink that contain colorless dye veins. Furthermore, there are chlorinated η-paraffins with more

'contains runner. than 20, for example 20 or 24 carbon atoms,

The leuco printing inks for stencils or stencils are of high viscosity and are used in a chlorine dye duplication printing process, Containing a degree of approx. 50% very viscous oils and wer-solvents, at least one colorless, in this which continues with a degree of chlorination of ' Solvent dissolved dye precursor and fine 70% solid.

Particles of at least one of the materials wax, chlorinated η-paraffins with a degree of chlorination

Fat, oil and thermoplastic synthetic compounds from 30 to 60%, however, have a high degree of solubility of high molecular weight, according to the dye precursors, and are chlorinated Finding is characterized in that the solution diphenyl with regard to the color formation rate from a chlorinated η-paraffin with a strength on construction paper is superior.

3 4

On the other hand, chlorinated isoparaffins, which are incorporated into auxiliaries such as waxes and fats by chlorinating isoparaffins or oils, natural high-molecular vex compounds, are considerably yellowish-colored oils that not only have an offensive odor, but also the after- u, the like, for the purpose of improving the printing parts easy hydrogen chloride and 5 colorability as printing ink and controlling the flow easy discoloration of the dye precursor in the case of ability and thixotropic property, (3) earth heating to 50 to 130 ° C when the fibrous material heat the mixture is to be released to the dissolution d ^A s dye precursor is show. Precursor in the solvent and at the same time for

That is why the use of chlorinated iso-dissolution or melt is one of the auxiliaries among paraffins as the main solvent in Leukodruck- io formation of a uniform solution, cooling under colors unfavorable. Stirring to precipitate part of the total

The solvent according to the invention for dL · amount of auxiliaries in the fine particles in the LOE Leukodruckfarben consisting of chlorinated n-paraffins solution of the dye precursor in the chlorinated NEN having a viscosity from 0.2 to 25 poises η-paraffin, in which If more than 1% min at 25 ° C with a degree of chlorination of more than 15 at least one of the auxiliaries, which individually or 30% to less than 60%. With a viscosity value in combination of two or more used of below 0.2 poise, a solid-liquid can become, without solution in the chlorinated keitstrennuBg in the production of the leuco printing η-paraffin remains and obtained by precipitation during the coloration, so that the separation of the oil is kept cool in fine particle form, so that it becomes easy, and materials over 25 poises are 20 the chlorinated η-paraffin in nets or casts of the sit a too high a viscosity to good print images aids is kept, and (4), required to achieve on the exit arches. if adding finely divided cellulose powder,

Furthermore, in chlorinated η-paraffins with powdered gum arabic or short fibers,

a degree of chlorination below 30% the dye, for example of polyamide or polyester.

Precursors difficult to solve and those with 25 when practicing the process is

a degree of chlorination of more than 60% makes it possible to have two or more kinds of chlorinated

sit a high viscosity and easily give a η-paraffins with different viscosities and

Chlorinated water: '. Off separation. Degrees of chlorination as the main solvent

The chlorinated η-paraffins can usually turn and also 1 to 20% auxiliary solvents

in a proportion of; and 3j percent by weight, to be added.

put on leuco printing inks, 'to be used. Particularly superior solvents for the leukc

in particular, excellent printed images are made with we- printing inks according to the invention is a mixture

nig stains in the screen print on the construction paper from 80 to 90 parts of chlorinated η-paraffin with

obtained when a leuco printing ink with a degree of chlorination of 50% and 12 to 14

chlorinated η-paraffin with a viscosity of 35 carbon atoms and 20 to 10 parts of a chlorinated

1 poise to 13 poises is used. η-paraffins with a degree of chlorination of

Furthermore, the leuco printing inks with 30 to 35% and 12 to 14 carbon atoms,

chlorinated η-paraffin as a solvent for the As auxiliary solvents can in the context of

Pigment base extremely low mist formation, for example liquid paraffin, silicone oil,

on the die-printed sheets, which 40 alkylbenzenes and the like are used. Also can

due to the solubility of the resin layer on a less than 5% chlorinated isoparaffin

Typewriter stencil paper is caused to be mixed.

as they are often used for stencil duplication printing. The leuco printing inks according to the invention are generally packaged in a tube compared to the known ones or can be leuco printing inks containing chlorinated diphenyl by releasing small amounts when they are used; so z. B. a fog formation on the whole as printing ink for a rotary copier th surface of the printed sheets from 400th to or duplicator are used, will each -600. printed sheet in the former case and in the latter case preferably in the form of leuco printing inks used from 100th to 150th printed sheets without stains on the sheets. Therefore, there is an extremely difficult 50 hand or cloths in the pressure stage,
remarkable difference in the number of sheets to be printed by applying a stencil paper to the sheet of leuco printing ink. Like the application of the leuco printing ink to a carrier, which has already been mentioned above, the chlorinated ones are resistant to the leuco printing ink, and in an η-paraffins they have various superiorities as a soldered frame-like state. Examples of dissolving agents for dye precursors, such as those used in Leukoger, include cell glass, inks coated with polymer films, not only opposite papers, synthetic polymer sheets and coated with over-chlorinated isoparaffins, but also with different types of polymers over-coated with chlorinated diphenyl, which is an excellent or coated polymer,
netes solvent for the previously known leuco from leuco printing inks, which represent printing inks with this, with regard to the lower 60 printing ink in a thickness of 200 μ on a mist formation, which were covered by master paper for writing carrier, 200 to 300 machines were caused is obtained, lower odor, low-pressure sheet, in the stage of matrix toxicity and cost. Printing using the Leukodmck sheet

A typical example for the production of the leuco becomes one by means of optical, electrical, thermal

printing color is given below. 65 or mechanical working methods open die

The following steps were applied in combination to the ink-coated surface of the

applied, (1) mixing a dye precursor leuco printing ink sheet brought and so that the

with chlorinated n-paraffin as solvent, (2) single-tone coated paper with the die surface in

Contact comes, by means of a roller, to the excessively low molecular weight for this purpose, with the aid of the image the leuco printing ink from the openings was added to a uniform solution and then Place the die on the clay-coated paper and cool to room temperature with stirring, where formation of color images corresponding to the open- through a black-brown, paste-like leuco print the die on the clay-coated paper was painted 5, the precipitated very small presses and the mass production of printing material contained particles of spermaceti and paraffin wax, The leuco printing ink was then lightened to a warmth by repeating this operation and carried out with great success. Sealable cell glass applied, leaving a space

The invention is described below with reference to to the extent of a thickness of 200 μ for production

Examples explained. io of the leuco ink sheet was obtained. A

Example 1 Thermal matrix paper with openings was then made

together with the leuco printing sheet and tone-over-

A mixture of 95 g of chlorinated η-paraffin drawn paper is attached and used for transfer

(Degree of chlorination 43%, viscosity 2 poises for the Leukodnick paint on the clay-coated paper

25 ° C) and 2.0 g of crystal violet lactone were pressed at 15 through the openings of the template paper

a temperature below 65 ° C for the dissolution and thereby red print images on the clay-coated

heated. Obtained after adding 18 g of microcrystalline paper; this operation was again

Wax with a melting point of 70 to 72 ⁰ C and more than 300 sheets of the same printing

The mixture obtained was heated to 75 ° C, so that the material was obtained

that a uniform solution was obtained. These 20 B e i s D 'e 1 3

Solution was brought to room temperature with stirring ^p

cooled and thereby a pale greenish paste- To a mixture of 90 g of a chlorinated

obtained like leuco printing ink, in which precipitated η-paraffin (degree of chlorination 50%, viscosity

microcrystalline wax was included. If the 6 poise at 25 ⁰ C) of a chlorinated η-paraffin with

Leuco printing ink on construction paper by means of a degree of chlorination of 30% (viscosity

was duplicated, 0.2 poise at 25 ⁰ C) and 2.0 g of 3-methyl-2,2'-

Obtain clear blue images on the press sheets. With spirobi (benzo [f] chromene) 12.0 g of bleached material were obtained

this leuco printing ink it was possible to add more than beeswax.

'500 sheets of print material without damage to the The resulting mixture was then heated to 110 ⁰ C.

To obtain stencil paper; Furthermore, the Ma- 30 was heated to dissolve and brought to room temperature

t: erial odorless. cooled by stirring, creating a pale green

A mixture of 95 g of chlorinated η-paraffin paste-like leuco printing ink was obtained.

(Degree of chlorination 50 to 52%, viscosity 12 poise.

at 25 ° C), 5 g of castor oil and 1.5 g of Rhodamine-B matrix paper with openings on a clay-coated

I ^ acton was heated to dissolve. Then 35 nes of paper were applied that were deep green

12 g Spermaceticum, 2 g paraffin wax with a reproduction on the clay-coated papers

The peak point of 68 ° C and 3, C g of a polystyrene forms.

Claims (1)

1 2 degree of chlorination in the range from 30 to 60% chlorine, claims: based on weight, and a viscosity of 0.2 to 25 poises at 25 ° C. 1. Leuco printing ink for stencil or template In general, the dye precursor is colorless dye duplication printing process, containing 5 and forms a color on contact with an elekein solvent, at least one colorless material which accepts the dye, so that a printing ink containing the dye precursor dissolved in this solvent is colorless or and fine particles of at least one of the materials is at most slightly colored. Therefore, when the wax, grease, oil and thermoplastic syn- an ordinary paper is printed with the printing ink, high molecular weight compounds are not obtained, clearly printed images are not obtained. Is any weight, characterized in that on a paper coated or impregnated with a electron-absorbing solvent from a chlorinated η-Par material with a degree of chlorination in the range of, which is subsequently referred to as clay-coated paper, 30 to 60% chlorine by weight is referred to, clear color images are formed,
and a viscosity of 0.2 to 25 poises at 15. The leuco printing ink according to the invention contains 25 ° C. a chlorinated η-paraffin that dissolved a colorless one