DE1692874B1 - Process for regenerating waterproof paper - Google Patents

Description

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The invention relates to a method for the regeneration reaction. Even with this well-known

of waterproof paper, in particular of processes, it is about surface-active

Papers that contain a formaldehyde compound, bonds that the peeling of the printing inks from

by means of acid hydrolysis. to facilitate the paper fiber. Furthermore is still

In particular, it relates to a method for regeneration ration of papers made with the help of urea for the regeneration of waste paper by means of an alka-formaldehyde resin, Melamine-formaldehyde resin and aqueous liquor are known, whereby a water-like synthetic agent made water-resistant glass, at least one oxygen-releasing compound was connected are. Examples of such waterproofing, at least one nitrogen in amide or sulfone papers are: towels, maps, label paper containing an amide-like bond and protective colloid and collotype papers. at least one nitrogen-free organic compound

To regenerate papers of this type, it is known that a solution containing a wetting and washing effect can be used up by means of an acidic hydrolysis. This mixture must close the corresponding one. In most cases, rather strong sulfonic acids are always contained in the form of salts, since they are acids or strongly acidic agents, such as an alkaline liquor and aluminum sulfate, while water glass is always present as the acid sulfur. Feic acid is also a well-known agent, just like that in this process, there is no acid hydrolysis of strong sulfamic acid NH ₂ SO ₃ H.

In the regeneration of old, waterproof In contrast to these well-known processes

The object of the method according to the invention is to form paper by means of all the previously known means

always the aggressiveness of the agents used in water containing formaldehyde compounds

with respect to the cellulose fiber itself and with respect to solid waste paper to be regenerated by means of acid hydrolysis

the metal apparatus has a serious disadvantage. ire. Furthermore, in the invention

Working in acid-resistant equipment means that the above-mentioned disadvantages are avoided,

known to have many disadvantages. This apparatus 25 with a favorable digestion of the waterproof

are very costly and often difficult to produce in paper with a minimum of attack by fiber

th shape and dimensions available. One has then and apparatus is possible. According to the

also proposed that the substance obtained by adding inhibitors of the invention is to be used for

gates of corrosion of the metal parts of the apparatus processing of paper directly suitable,

to control. Various amines can be used as inhibitors. The process according to the invention is notable

and Imine known. The use of all of these by being used as an acidic agent for the hydro-

But inhibitors also have major disadvantages. lysis at least one organic, aliphatic or

To achieve a good, protective effect, aromatic compound is needed in the molecule

usually quite large concentrations are required, except for at least one acidic reacting group

which is expensive, while in most cases 35 also contains at least one group that is anti-corrosive

a not insignificant attack occurs. has sive properties.

Also requires the correct dosage and mixture in the method according to the invention have

The inhibitors do extra work and pay attention to the organic compounds other than an acid

sameness. reacting group contain an NH _{2 group,}

From British patent specification 438 403 a 40 has been shown to be particularly suitable.

Process for the purification or recovery of As examples of suitable aliphatic

Recycled paper known, whereby the cleaning on the table compounds are mentioned: glutamic acid, Removal of paints, fats, oils, waxes

and the like, i.e. the removal of any HOOC-CH ₂ Ch _{2 -CHNH 2} COOH,
Refers to impurities that 45

The use of the paper on this glycocolla, NH ₂ CH ₂ - COOH and compounds were deposited. For this purpose, in this known process using molecules with straight or branched carbon, the paper is niched with a water-soluble derivative chain with at least one free NH ₂ group vat of sulfuric acid with high molecular weight organic and at least one free SO ₃ H group in the molecule Compounds or with a water-soluble 50 As aromatic compounds, the naphthyl neutralization products of these derivatives, which are soap aminesulfonic acids
have a similar character, treated. These substances

however, typical wetting agents and emulsifiers are C ₁₀ H ₆ (NH ₂ ) SO ₃ H, C ₁₀ H ₅ (NH ₂ ) (SO ₃ H) ₂
which can contain the grouping RNH - R.

It should be noted, however, that wet strength 55 ^u

Papers, ie papers containing formaldehyde compounds C ₁ OH ₄ (NH ₂ ) (SO ₃ H) ₃
fertilizers have been made wet-resistant, cannot be regenerated with surface-active substances. are mentioned, the choice of the total Furthermore, in this process no acidic hydro- 43 isomers depends on the possibility of a belyse being applied. From the German patent specification 60, correct isomer can be obtained more easily than another, 667 722 a process for the recovery of and also through the desired color of the end product is known from printed waste paper, the product can be determined,
whereupon the waste paper at elevated temperature is preferably used in the inventive solutions of condensation products from higher-level processes a sulfanilic acid, NH ₂ C ₆ H ₄ SO ₃ H. molecular fatty or resin acids with polymeric 65 Here too, all of these are used three iso-aminicarboxylic acids or their derivatives can be treated.

will. However, these products react almost neutrally, compounds such as toluidinsulphonic acids come into play

taking the advantage of neutral also into consideration. Generally one uses

3 4

of the acidic reagent concentrations between 1 and brought, and the amount of water was up to

5 g per liter, and it is thus supplemented at a temperature of 15,0001. The latter was done with return water

temperature of 60 ° C and higher a good digestion of the thickener, which water has a pH of 2.5

achieved. This means that afterwards had. The pH of the mass was 4.4. After a

Using the conventional means of paper running time of 1 hour at 80 ° C, it was found that

Production of the mass directly from the material obtained in this way after passing through a thickener

a speck-free paper can be made. and a uniaxial fiberizer completely free of specks

The attack of iron, determined by weight. After the regeneration, the

loss under comparable circumstances, the material obtained always turned out to be known per se

with sulfanilic acid as considerably smaller than with io for sheets and webs of very good quality paper

Use of sulfuric acid or aluminum sulfate can be processed.

with various inhibitors. It has also been shown, except in the above examples, that it is mostly not necessary to use pure compounds on an industrial scale for many and in practice, and that the same result is obtained in borrowed tests on a laboratory scale with the use of technical qualities different acidic agendas containing NH _{2 groups.} zien found, among other things, that even paper,

Also a mixture of different of the named ones made waterproof with a high percentage

Compound types may optionally be advantageous melamine-formaldehyde resin, such as waste from English

to be needed. General staff cards with the inventive method

_,. . , _T ao drive could be processed very well.
Example I

15001 of water, Example V
brought and 10 kg of crude, unground sulfanilic acid.

The pebble cooker was closed, with steam. 20 g was softened with melamine formaldehyde.

heated and rotated for 15 minutes. Then 25 old paper that has been made secure (from English gen-

When the sulphanilic acid was dissolved and the ball-point map) in 11 water, the 5 g of glutamic acid cooker open. Then they put them in the stove

1350 kg with urea-formaldehyde resin waterproof HOOC - (CH ₂ ) ₂ - CH - NH ₂ - COOH
made-waste of paper labels and still

15001 warm water. After closing the 30 contained, at pH 4.0 for 35 minutes

Kugelkochers the digestion now took place at 120 at 85 ^° C. After this paper was in

up to 130 ° C. After 1.5 hours of boiling a Kennwood mixer was allowed to stir

Mass processed into a speck-free paper, this paper is pretty well fiberized, and after that

will. was heated for 30 minutes at 85 ° C and during

B e i s 0 i e 1 II 35 stirred for 2 minutes in the Kennwood mixer

was, it was frayed free of specks.

In a ball cooker, 20 kg of crude, unground sulfanilic acid were poured into 30001 Example VI for 15 minutes
Water dissolved under steam heating. Thereafter

3000 kg were washed with urea-formaldehyde resin. 20 g were softened with melamine-formaldehyde

water-proofed waste paper in the kettle cooker water-proofed old paper (from English

brought with another 30001 water. The pH of the liquid general staff cards) in 11 water, the 2.5 g of embers

speed was 5.5. After 2.5 hours of boiling the amic acid was able to be contained, while at a pH of 4.15

Mass can be processed into speck-free paper. 1 hour at 85 ° C. After 2 minutes in the

The temperature during the digestion was 120 to 130 ° C. 45 Kennwood mixer had stirred, this was

The paper is frayed free of specks.

Example III

Example VII

In an "Escher-Wyss Pulpmaster" of 8 m ³

20 kg of crude sulfanilic acid were dissolved in 3000 l of water. Formaldehyde resin made water-resistant, white light amine- (l) -sulfonic acid (6) (Cleves acid-1,6) - added when printing paper waste. The water was also supplemented with a pH of 3.69 for 1 hour at 85 ° C. up to 70001. After a running time of 55 hours, after 2 minutes in the Kennwood mixer for 1.25 hours, the mass was well frayed and the device had been stirred, the fabric obtained was a speck-free paper, dyed a little gray, but fairly speck-free, could be made from it. The temperature during this processing was 9O ⁰ C, and the pH value of the liquid Example VIII
was 4.6. 60

. . It softened 20 g of urea formaldehyde example iv waterproof-made paper (waste of fotoin a hydrapulper of 16 m ³ capacity were graphic papers) in 11 water, 5 g naphthyl 30 kg crude sulfanilic acid in 50001 water at 8O ⁰ C amine- (2 -sulfonsäure- (l) (Tobias acid) contained in dissolved. at the same time, 1200 kg of water-tight, 65 a pH of 4.32 for 1 hour at 85 ⁰ C. white light printing paper which partly with urea After 2 minutes in the Kenwood mixer -Formaldehyde resin and partially stirred with melamine molding device, the material obtained was aldehyde resin made water-resistant, dyed a little gray in the pulper, but fiberized fairly speck-free.

Example IX

20 g of waste paper made waterproof with urea formaldehyde (waste from photographic Papers) in 11 water containing 5 g of naphthylamine- (2-sulfonic acid- (6) (Brönner's acid), at a pH of 4.42 for 1 hour at 85 ° C. After stirring for 2 minutes in the Kennwood blender, the fabric obtained was green-yellow in color, but rather well fibrillated.

IO

Example X

20 g of waste paper made waterproof with melamine-formaldehyde were softened in 11 of water that 5 g of naphthylamine- (l) -disulfonic acid- (3.8) contained, at a pH of 4.1 for 1 hour at 85 ° C. After stirring for 2 minutes in the Kennwood blender, the resulting fabric was pink Accepted color but was frayed well.

Claims (3)

Patent claims: 1. Process for regenerating waterproof paper, especially papers that contain a formaldehyde compound, by means of acid hydrolysis, thereby characterized e t that the acidic agent for the hydrolysis is at least one organic, aliphatic or aromatic Compound used in the molecule except for at least one acidic reacting group also contains at least one group that has anti-corrosive properties. 2. The method according to claim 1, characterized in that the group with the anti-corrosive properties is an NH ₂ group. 3. The method according to claim 2, characterized in that a sulfanilic acid NH ₂ C ₆ H ₄ SO ₃ H is used as the acidic agent.