US1925526A

US1925526A - Coloring paper and the like

Info

Publication number: US1925526A
Application number: US484245A
Authority: US
Inventors: Dotzel Franz
Original assignee: IG Farbenindustrie AG
Current assignee: IG Farbenindustrie AG
Priority date: 1929-10-14
Filing date: 1930-09-24
Publication date: 1933-09-05
Anticipated expiration: 1950-09-05

Description

Patented Sept. 5, 1933 COLORING PAPER AND THE LIKE Franz Dotzel, Ludwigshafen-on-the-Rhine, Germany, assignor to I. G. Farbenindustrie Aktiengesellschaft, FrankIort-on-the-Main, Germany N Drawing.

Application September 24, 1930,

Serial No. 484,245, and in Germany October 12 Claims.

stuffs. The phenomenon is therefore particular-- ly marked with the use of paper from mixed paper pulp. It has been tried to avoid this disagreeable eifect by a-treatment with tannin, but the results are not satisfactory.

I have now found that paper, which term is meant to include paper ofany size, 1. e. thin paper as well as pasteboard and the like, can be colored in a manner free from the aforesaid objections with organic dyestuffs, such as basic, substantive and similar dyestuffs, and that therefore very valuable uniformly colored paper and the like can be obtained by treating the substances serving for the preparation of the paper and the like during the working up thereof, or by treating the paper and the like themselves before, or at the same time as, coloring them, with certain artificial tanning agents. After thorough mixing, the pulp is colored and sized in the usual manner. The artificial tanning agents suitable according to my present invention correspond to the general formula R- X- R- in which R defines a monoor polycyclic aromatic nucleus, which may contain further non-aromatic substituents, and X is CH2, CHz-NH or S. Thus for example tanning compounds of the type (3H, /SO;H S\ l? .11, HO 0H 1 H or v soln I 802B Patents Nos. 297,187, 297,188, 319,713 and 320,613

also describe the preparation of tanning mate rials suitable for carrying out the present invention. Particularly good results are obtained with aromatic sulphonic acids corresponding to the last mentioned formula and their efliciency may be further increased by converting the acid tanning agents of the aforesaid nature into their alkali metal salts and adding, if desired, from 0.5 to 5 per cent their weight of alkali metal bisulphate. V

The quantities of the artificial tanning agents employed are generally between 0.2 and 5 per cent of .the paper pulp or paper, quantities between 0.5 and 1 per cent being usually satisfactory.

The good results obtainable according to the present invention are most surprising since tanning agents of unsymmetrical constitution, as for example phenyl methylene naphthyl compounds, do not prevent the disagreeable mottled effects.

The following examples, in which coloring with dyestuffs particularly tending to give mottled dyeings is described, will further illustrate the nature of this invention, but the invention is not restricted thereto.

Example 1 From 0.5 to 1 per cent of the sodium salt of the synthetic tanning agent, prepared by condensation of fl-naphthalene sulphonic acid and formaldehyde, and which has been dissolved in water, incorporated with from 1 to 3 per cent its weight of sodium bisulphate and rendered neutral, is added to the paper pulp in a hollander. The pulp is then colored according to the desired shade, as for example with methylene Blue (Color Index, No. 922) or Cotton black RW extra (Color Index, No. 582) and sized in the usual manner. In the product obtained all fibres are equally dyed.

Example 2 1000 parts of a mixture of 7.5 parts of bleached sulphite pulp and 2.5 parts of unbleached sulphite pulp are worked in the paper machine together with 10 parts of the tanning agent, prepared by a condensation of phenol with sulphur and alkali, 500 parts of water and 5 parts of the dyestuff Vesuvine B (Color Index, No. 332). Thoroughly uniform dyeings are obtained.

Example 3' 1000 parts of a mixture of equal parts of mechanical pulp ana of unbleached sulphite pulp densation of B-naphthalene sulphonic acid and formaldehyde, and which has been dissolved in .water and rendered neutral, 500 parts of water and 2 parts of Cotton black RW extra (Color Index, No. 582). The dyed paper or pasteboard does not show any mottled efiects.

What I claim is:'- I

l. The process for coloring paper with an organic dyestuff selected from the class consisting of basic and substantive dyestuffs which comprises treating paper pulp at least during the dyeing operation with a synthetic tanning agent containing the grouping (R- X- R-)y in which t is greater than 1, R is an aromatic nucleus and X is CH2, CH2NH or S.

2. The process for coloring paper with an organic dyestufi selected from the class consisting of basic and substantive dyestuffs which comprisestreating paper pulp at least during the dyeing operation with a synthetic tanning agent result- .ing from the condensation of a naphthalene sulphonic acid with formaldehyde.

3. The process for coloring paper with an organic dyestuff selected from the class consisting of basic and substantive dyestuifs which comprises treating paper pulp at least during the dyeing operation with a synthetic tanning agent resulting from the condensation of a naphthalene sulphonic acid with formaldehyde, and subsequent neutralization.

4. As a new article of manufacture papercomprising a synthetic tanning agent containing the grouping (R- X- R-)y in which 1/ is greater than 1, R is an aromatic nucleus and X is CH2, CH2- NH or S, which is uniformly colored by an organic dyestufi selected from the class consisting of basicand substantive dyestuffs.

5. As a new article of manufacture paper comprising a neutralized synthetic tanning agent containing the grouping (R- X: R011 in which 31 is greater than 1, Ris an aromatic nucleus and X is CH2, CH2NH or S, which isuniformly colored by an organic dyestuif selected from the class consisting of basic and substantive dyestuil's.

6. Asa newarticle of manufacture paper comprising a synthetic tanning agent resulting from ne ates;

tion for uniformly coloring paper, comprising a neutralized synthetic tanning agent containing the grouping (R X- R011 in which 31 is greater than 1, R is an aromatic nucleusand X is CH2,

CHz-NH or S and a paper dyeing coloring material selected from the class consisting of basic and substantive dyestuffs.

9. As a new'article of manufacture a preparation for uniformly coloring paper, comprising a synthetic tanning agent resulting from the condensation of a naphthalene sulphonic acid and formaldehyde-and subsequent neutralization with an alkali and a paper dyeing coloring material selected from the class consisting of basic and substantive dyestufi's.

10. A composition of matter comprising paper pulp, a synthetic tanning agent containing the grouping (R- X- Roy in which 1/ is greater than 1, R is an aromatic nucleus and X is CH1, CH2 NH or S, and an organic dyestufi selected from the class consisting of basic and substantive dyestuffs.

11. A composition of matter comprising paper pulp, a neutralized synthetic tanning agent resulting from the condensation of a naphthalene sulphonic acid and formaldehyde, and an organic dyestufl? selected from the class consisting of basic and substantive dyestufls.

12. A composition of matter comprising mechanical pulp and unbleached sulphite pulp, the sodium salt of a synthetic tanning agent resulting from the condensation of beta-naphthalene sulphonic acid and formaldehyde, and an organic dyestuif selected from the class consisting of basic and substantive dyestufis. I

. FRANZ DOTZEL.

will