DE1264384B - Process for modifying a cellulosic material - Google Patents

Description

Method of Modifying Cellulosic Material The invention is an improvement on the method of U.S. Patent 2,772,188 for modifying cellulosic materials to increase the degree of polymerization and insolubility of a further polymerizable methylol phosphoric polymer on the fiber by reacting the further polymerizable polymer with ammonia. The type of further polymerizable compound is explained in more detail in the above-mentioned patent specification.

The reaction taking place according to the aforementioned patent is a crosslinking in which a high molecular weight substance is insoluble in water receives.

The reaction is explained in more detail below: As the molecular weight of the polymer increases, it becomes increasingly difficult to trifunctionally react each phosphomethylol group with ammonia in the manner indicated above, and the end product can thus contain bifunctional or monofunctional bonds, i. H.

> P - CH2 - NH - CH2 - P <and > P - CH2 - NI-I2 (The ammonia is usually in excess.) If the reaction is carried out in cellulose-containing material or on cellulose-containing material, such bifunctional or monofunctional bonds should be used not be present to a substantial extent, since this would ren leadership to a decreased water resistance of the treated material. According to the invention, this is achieved better than according to the known method. The improved properties that cellulosic materials according to the invention, e.g. B. in the form of fibers, yarns and textiles made from natural or regenerated cellulose, films, pulp, paper, fiberboard or wood are given increased dimensional stability, improved crease resistance in the wet or dry state, better dyeability, improved resistance to rot, change in surface gloss, change in the handle and in the draping, improved abrasion resistance and particularly improved non-flammability and glow resistance According to the USA patent specification * 2 772 188 ammonia should be in the form of gaseous ammonia, ammonium hydroxide, a solution of ammonia in an inert solvent or as in situ from an ammonium salt use ammonia developed from a weak acid.

The impregnated and dried cellulosic material is treated with gaseous ammonia, the reaction rate is very slow, since that Ammonia must diffuse through the material entirely in order to fully interact with the methylol phosphoric polymer to react. It is true that a fully converted product can be obtained in this way, but usually the cellulose-containing material must be kept at room temperature for a long time one Expose to atmosphere containing ammonia. There is also the reaction is exothermic, the temperature of the cellulose-containing material can under certain circumstances rise undesirably high.

On the other hand, if the dried cellulosic material is treated Crosslinking takes place solely with aqueous ammonia or ammonium carbonate solution very quickly and is completed in a few minutes at room temperature. The ammonia solution easily penetrates the cellulose-containing material, absorbs it during the reaction generated heat and thus prevents an excessive rise in temperature. That but has further polymerizable methylolphosphorus polymer when working with aqueous Ammonia alone tends to migrate to the surface of the material before it does has reacted sufficiently with the ammonia. This is particularly the case if the cellulose-containing material is insufficient before the ammonia treatment was dried. The tendency of the methylol phosphoric polymer to stick to the surface of the Migrating cellulosic material is disadvantageous in two respects: That Polymer on the surface gives the material a mottled appearance and is easily removed by a few washing treatments and is therefore ineffective.

From the above it can be seen that both the treatment with gaseous Ammonia alone as well as the treatment with aqueous ammonia alone have disadvantages brings itself.

The inventive combined use of gaseous and aqueous Ammonia makes up the advantages of both types of treatment while avoiding the disadvantages benefit from each individual treatment. In particular, it avoids the further polymerizable Methylolphosphoropolymer migrates to the surface of the cellulosic material. Therefore, the cellulosic material remains free from stains and the polymer becomes also not replaced by many washing treatments. According to the invention, the combined use of gaseous and aqueous ammonia so that ffi on the impregnated and dried cellulose-containing material first of all of the action exposing the gaseous ammonia and then treated with aqueous ammonia. Treatment with gaseous ammonia causes an initial reaction between the ammonia and the methylol phosphoric polymer in sufficient quantities to substantially form the polymer to make immobile in the cellulosic material. The subsequent treatment With aqueous ammonia, the reaction quickly comes to an end after this fixation.

The process according to the invention comprises the following steps: 1. Treating the cellulose-containing material with a further polymerizable methylol phosphoric polymer, in particular in the form of an aqueous solution or dispersion.

2. Drying the impregnated cellulosic material. 3. Action of gaseous ammonia on the dried material.

4. Treat this material with aqueous ammonia.

The aqueous ammonia system may be aqueous ammonia or an aqueous solution of an ammonium salt of a weak acid, e.g. B. ammonium carbonate or ammonium carbamate. Although during the further polymerizable Methylolphosphorpolymere the USA. Patent 2,772,188 are suitable for the present process invention include in particular the reaction products of a Tetrakishydroxymethylphosphoniumsalzes, z. B. Tetrakishydroxymethylphosphoniumchlorid (THPC), with urea, with urea and melamine or with urea and guanidine, suitable. Such precondensates are stable in storage and can be diluted relatively strongly without affecting their usability. The urea content in such masses should preferably not exceed 16 parts urea to 63 parts THPC, as otherwise the stability of the precondensate can be reduced. The amounts of melamine or guanidine can be varied over a wide range.

The THPC-urea precondensates, THPC-urea-guanidine precondensates and the THPC-urea-melamine precondensates can be produced by using a Mixture of THPC and urea, of THPC, urea and guanidine or of THPC, Urea and melamine refluxed in water and then rapidly cooled.

Advantageously, the THPC urea precondensate should be buffered in a known manner, since the pH of the precondensate is about 0.8 and the solution is therefore very acidic and would damage the cellulose-containing material. In this process, the amount of phosphorus remaining on the material is 40 to 80% of the amount of phosphorus originally applied. This percentage is referred to below as the phosphorus utilization value.

Surprisingly, a significantly higher phosphorus utilization value is achieved if the solution of the further polymerizable polymer is dulled by means of an alkali metal hydroxide, instead of z. B. with sodium or ammonium acetate to a pH of 3.5 to 4 buffer. The proportion of phosphorus that is then retained is over 90 () / (). This is noteworthy since it was more likely that the more reactive textile solution containing the alkali hydroxide would be less stable. Contrary to this expectation, solutions prepared using caustic soda are e.g. B. shelf life 3 months.

The amount of the alkali hydroxide used varies with the kind of the further polymerizable methylol phosphorus polymer, but is generally from 0.02 to 0.4 moles of alkali hydroxide per mole of THP salt used to prepare the methylol phosphorus polymer. It has been found that a very effective ratio is between 0.02 to 0.15 moles of alkali hydroxide per mole of THP salt. Example 1 A THPC-urea precondensate was prepared by refluxing a solution of 3160 parts of THPC and 498 parts of urea in 4012 parts of water for 30 minutes and then cooling it quickly. To this pre-condensate was added 20 parts of a nonionic wetting agent (. Eg Alkylphenyläthylenoxyd - condensation product) and 5000 parts water. A cleaned and bleached cotton body weighing 270 g (m2) is impregnated with this solution and squeezed off; 74 parts of the solution are retained on 100 parts of dry fabric. The impregnated cloth is dried at 90 to 95 ° C and then left for 10 Minutes of ammonia vapor by running it back and forth over a 24% ammonia solution. The textile is then treated in a 2.4% ammonia solution for 10 minutes. The textile is removed from this solution and treated Without rinsing in a solution of 5 parts of soap and 2 parts of about 30% hydrogen peroxide in 1000 parts of water, first 10 minutes at 40 to 50'C, then 10 minutes at 90 to 95'C, before finally being washed in hot water rinsed, squeezed off from the excess water and dried at 100 ° C. The dried fabric has a weight increase of 11 () / o compared to the original fabric, and shows .an excellent resistance to burning and afterglow if one it tested according to the fire test according to British Standard 3119, 1959 . These properties are not impaired if the textile is subjected to 10 successive 1 hour washing treatments in a boiling solution of 2 parts of soap and 2 parts of anhydrous sodium carbonate in 1000 parts of water. The phosphorus utilization value of the process after washing is 68.6%. Example 2 A THPC urea precondensate is produced in the same way as in Example 1 . 2530 parts of water and 345 parts of a solution of ammonium acetate, which was prepared by dissolving 600 parts of ammonium acetate in 400 parts of water, are added to the amount specified there. Three samples A, B and C of a cleaned and bleached, simply woven cotton cloth weighing 135 g / m2 are impregnated with this solution and squeezed off, 73 parts of the solution per 100 parts of dry cloth are retained. The samples are dried at 80 ° C. and then individually treated as follows. Samples A and C are exposed to ammonia vapor for 10 minutes by hanging them over a 24% ammonia solution. Sample C is then removed from the steam while Sample A is exposed to the action of the steam for an additional 10 minutes. Sample C is treated with a 2.4% ammonia solution for 10 minutes and sample B for 20 minutes. All three samples are then washed, rinsed and dried as in Example 1. The table below shows the weight gain, the non-flammability and the tear resistance of the three samples. Charring length - tear resistance of the Sample ammonia treatment increase in weight (according to British Standard wefts 3119, 1959) (after Elmendoro A 20 minutes steam 1.7% burns 1640 g B 20 minutes solution 9.81 / o burns 1585 g C 10 minutes steam 10.00 / 0 7.62 cm 1390 g + 10 minutes solution The phosphorus utilization value for sample C is 72.3%.

Example 3 The same impregnation solution containing THPC urea precondensate and ammonium acetate is used as in Example 2. Three samples D, E and F of a cleaned and bleached cotton fabric weighing 100 g / m2 are impregnated with this solution and squeezed off; 73 parts of the solution per 100 parts of dry tissue are retained. The three samples are dried at 80 ° C. and then individually treated as follows: Samples D and F are exposed to ammonia vapor for 10 minutes by hanging them over a 34% strength aqueous ammonia solution.

Sample F is then removed from the steam while Sample D is exposed to the action of the steam for an additional 10 minutes. Sample F is then treated for 10 minutes and sample E for 20 minutes with 34 () / () strength ammonia solution.

All three samples are then washed, rinsed and dried as in Example 1.

The weight gain, the non-flammability and the tear resistance of the three samples were determined in the same manner as in Example 2; the results are summarized below: Tear resistance Sample ammonia treatment weight increase charring length of the shot shutters, D 20 minutes steam 6.40 / 0 burns 1103 g E 20 minutes solution 0.80 / 0 burns 1120 g F 10 minutes steam 11520/0 5.2 cm 1088 g + 10 minutes solution If, in experiments D and F, dry ammonia gas from a commercially available pressure bottle is used instead of the ammonia vapor arising from the ammonia solution, the same results are obtained. Example 4 A THPC-urea precondensate is produced as in Example. To one half of the amount given there are added 1265 parts of water (solution P) and the other half 1265 parts of a solution containing 96 parts of triethanolamine dissolved in 1196 parts of water (solution Q). Two samples of a cleaned, single-weave cotton cloth weighing 135 g / m2 are impregnated, one in solution P, the other with solution Q; they are squeezed off, with 73 parts of the solution per 100 parts of dry textile remaining, and dried at 110 to 115.degree. The dry samples are then allowed to act as in Example 1 with ammonia vapor, treated with 2.411% ammonia solution, washed, rinsed and dried. Both samples have good non-flammability according to British Standard 3119, 1959, the sample treated with solution P has a tear strength of the weft threads of 700 g, while the sample treated with the triethanolamine-containing solution Q has a tear strength of the weft threads of 1200 g. The P treated sample increases by 5.6 () / o and the Q treated sample by 5.90 / 0. The phosphorus utilization value for sample P is 72.6% and for sample Q 70.6%.

Example 5 A THPC-urea precondensate is prepared as in the example. 7480 parts of water containing 200 parts of sodium acetate are added to the amount specified there. A sample of loose, cleaned American cotton fibers is impregnated with this solution and vacuumed; 122 parts of the solution are retained per 100 parts of fiber.

The fibers were dried at 70 to 80.degree. C. and then hung for 60 minutes over 24 (1 / o ammonia solution. Finally, the fibers are immersed in 2.4 () / o ammonia solution for 10 minutes before being washed, rinsed and rinsed as in Example 1 The treated fibers are dried kohlten only locally to if -. carded in one turn -. were exposed to an open flame, the phosphorus utilization-value is 56.8%.

Example 6 ' A THPC urea precondensate is prepared as in the example. 2875 parts of a solution of 198 parts of sodium acetate in 2677 parts of water are added to the amount indicated there. A sample of a bleached and mercerized cotton yarn is impregnated with this solution and squeezed off; 95 parts of the solution per 100 parts of yarn are retained. The yarn is dried at 90 ° C. , then treated as in Example 1 with ammonia vapor and ammonia solution.

The yarn is then washed without rinsing with a solution of 5 parts of soap and 2 parts of sodium carbonate in 1000 parts of water at 40.degree. C. for 30 minutes; then it is rinsed first in warm, then in cold water and dried at 100 to 105 ° C. The yarn treated in this way has greatly improved non-flammability; if a burning match is held by a single turn of vertically suspended twine, it will carbonize, but the flame will not be diffused or the twine will growl. The yarn treated as above stains much more deeply with Polar Brilliant Red G (Geigy) than the untreated yarn. In addition, the dyeing of the treated yarn was significantly more resistant to hot soap treatment than the dyeing of the untreated yarn. The phosphorus utilization value is about 70.00 / 0. Example 7 A THPC urea precondensate is produced as in Example 1 . To 300 parts of this precondensate are added 4.0 parts of sodium hydroxide, dissolved in 200 parts of water, with constant stirring. A cleaned and bleached cotton drill that weighs 200 g / m2 is impregnated with this solution and squeezed off so that it retains 75 parts of the solution per 100 parts of dry textile. The impregnated textile is then dried at 85 to 90 ° C. for 10 minutes, exposed to pure gaseous ammonia for 10 minutes and finally treated with 4.50% strength aqueous ammonia for 10 minutes. The textile is then washed without rinsing in a solution of 5 parts of soap and 2 parts of about 30% hydrogen peroxide in 1000 parts of water for 10 minutes at 40 to 45 ° C and then 10 minutes at 90 to 95 ° C, before finally being washed in hot Rinsing with water. The textile is squeezed off and dried at 120.degree. The dry textile has a weight increase of 15.6%. The treatment gives excellent fire resistance according to British Standard 3119, 1959. The non-flammability is not impaired if the treated textile is subjected to five successive 1 hour washing treatments in a boiling solution of 2.5 parts of soap and 2.5 parts of anhydrous sodium carbonate per 1000 parts of water. The phosphorus utilization value after the washing treatments is 91.0%.

Claims (2)

Claims: 1. A method -kennzeichnet that the method of modifying a cellulose-containing material by impregnation with an aqueous solution or dispersion of a further polymerizable Methylolphosphorpolymers having at least one free methylol group on the phosphorus atom, followed by drying and treatment with ammonia, d a d u rch g e Ammonia treatment is carried out first with gaseous and then with aqueous ammonia. 2. The method according to claim 1, characterized in that an alkali hydroxide-containing polymer solution or dispersion is used for impregnation. Contemplated references: French Patent No. 1,136,493, British Patent No. 740,269, USA. Patent No. 2 772 188. In the notice of application, an Versuchsbereicht has been designed....