CS201185B1 - Process for producing modified cellulose-based materials or derivatives thereof - Google Patents

Abstract

The invention relates to the production of modified materials based on cellulose or its derivatives by the action of organic compounds containing -NCO groups. The procedure allows for a wide modification of the processed materials, especially from the point of view of application properties, while the basic technology practically does not change. The essence of the invention is that materials based on cellulose or its derivatives are treated in the presence of water with a crosslinking solution containing 0.002 wt. to 10 wt. % of hydroxamic acid, prepared via sulfoxamic acid from the respective organic compounds containing the same number of -NCO groups in the molecule, 0.01 to 0.5 wt. of emulsifier, 0.0005 5" wt. to 1 wt. of catalyst and 0.2 to 6 5O wt. of softener, while the modification process includes subsequent drying and heat treatment of the modification material.

Description

The invention relates to the production of modified materials based on cellulose or its derivatives by the action of organic compounds containing -NCO groups. The procedure allows for a wide modification of the processed materials, especially in terms of application properties, while the basic technology remains practically unchanged.

The essence of the invention is that materials based on cellulose or its derivatives are treated in the presence of water with a crosslinking solution containing 0.002 wt. to 10 wt. % of hydroxamic acid, prepared via sulfoxamic acid from the respective organic compounds containing the same number of -NCO groups in the molecule,

0.01 to 0.5 wt. of emulsifier, 0.0005 wt. to 1 wt. of catalyst and 0.2 to 6.5 wt. of fabric softener, whereby the modification process includes subsequent drying and heat treatment of the modification material.

201 1B5

According to the present invention, modified materials based on cellulose or its derivatives are produced by the action of organic compounds and containing -NCO groups. These materials are characterized by better physical and mechanical properties. The procedure allows for a wide modification of the processed materials, especially in terms of application properties, while the basic technology remains practically unchanged.

Modification of fibers based on cellulose or its derivatives, e.g. by crosslinking, has become topical especially recently, when significantly improved physical and mechanical properties are required from these materials. Isocyanates are also used as crosslinkers.

Patent literature discloses processes in which aryl isocyanates are used to provide altered dyeability to cotton cellulose (British Pat. No. 31,019) or increased compressive strength and mineral acid resistance (U.S. Pat. No. 2,993,888) while maintaining the fibrous structure of the cellulose. Some halogenated phenyl isocyanates have been used to provide flame retardant treatment (U.S. Pat. No. 2,428,843). Certain types of substituted phenyl isocyanates provide water repellent treatment (U.S. Pat. Nos. 2,303,363 and 2,370,405). For modification, durylene diisocyanate, 2,4-toluene diisocyanate (Ellzey S. E., Maoh C. H., Text. Res. J. 32. 1023-1029 /1962/) were used in a dimethylformamide or dimethyl sulfoxide environment, and the extent of the reaction depends on the ability of the solvent to swell the fiber.

Di-n-butyl-Sn-diacetate has proven to be a good catalyst. In the aforementioned work, the authors also attempt to treat by the impregnation-dry condensation method, but the toxicity of most diisocyanates has limited their practice to the use of bis(4-isocyanatocyclohexyl)methane, which is less toxic. There are other works (USA Pat. 3 00?. 763) that propose a multiple treatment process in an environment of anhydrous dimethyl sulfoxide. From the state of the art mentioned so far, it can be concluded that isocyanates can achieve a significant improvement in the physical and mechanical properties of the fiber, but the disadvantage of their use is the application from high-boiling anhydrous solvents, which is technologically and economically very demanding, while side products such as symmetrically substituted ureas are formed due to moisture in the fiber.

According to the present invention, modified materials based on cellulose or its derivatives are produced by treating at least one organic substance containing 1 to 4 hydroxamic acid functional groups in the molecule with a cellulose material or materials from cellulose derivatives, in the presence of auxiliaries, emulsifiers and catalysts, such that the materials based on cellulose or its derivatives, preferably in the form of fibers, are treated in the presence of water with a crosslinking solution containing 0.002% by weight to 10% by weight of hydroxamic acid, preferably in the form of a reaction product prepared via sulfoxamic acid from the corresponding organic compounds containing the same number of -NCO groups in the molecule,

0.01 to 0.5 wt. % emulsifier, 0.0005 wt. % to 1 wt. % catalyst and 0.2 to 6 wt. % softener, whereby the modification process includes subsequent drying and heat treatment of the modification material.

According to the present invention, modified materials based on cellulose or its derivatives are produced by the action of isocyanates modified by chemical processes so that they can be

201 18S apply* in an aqueous medium, while when using a monofunctional isocyanate, modification occurs without crosslinking and the effect of polyfunctional ones takes place. The treatment of isocyanates consists in adding, for example, sodium hydrosulfite to the original isocyanate to form sulfoxamic acid, which, under the action of an aqueous alkali hydroxide solution, releases sodium sulfite and forms hydroxamic acid. In this way, highly crosslinked fibers can be produced when hydroxamic acid, as a derivative of polyfunctional isocyanate, is formed in situ by splitting off water during the ^heat treatment process. The fiber at this stage no longer contains water, so that the released isocyanate reacts exclusively with cellulose or its derivative. For the preparation of hydroxamic acids, it is possible to use almost all types of isocyanates, such as hexamethylene diisocyanate, 2,4- and 2,6-toluene diisocyanate, 1-4-benzene diisocyanate, 1,5-naphthalene diisocyanate, etc., or aromatic triisocyanates, such as triphenylmethane-4,4', 4-triisocyanate, but also others commercially available types, possibly also dlmers, trimers, etc.

Sodium hydrosulfite is used as another reactive component, most often available as an aqueous solution, preferably anhydrous sodium bisulfite or sulfur dioxide. The hydrolysis of the resulting bisulfite adduct is carried out with solutions of alkali metal or alkaline earth metal salts, preferably sodium hydroxide.

The process of preparing the crosslinking solution consists in emulsifying the powder, preferably paste, of hydroxamic acid, which can also be used in the form of a reaction product, in water at a concentration of 0.02 kg/nr to 100 kg/nr with the preliminary addition of an emulsifier and the subsequent addition of a catalyst and a softening agent.

The most common emulsifiers are non-ionic surfactants based on a β-ethoxylated mixture of higher fatty alcohols (Slovasol SF, Slovasol MKS), unsaturated higher fatty acids (Slovasol A) or a mixture of mono-, di- and triester of ethoxylated alkylphenol with phosphoric acid (Slovafos 3),

The most common catalysts are amines and amino alcohols, compounds of tin, lead, zinc, arsenic, antimony, bismuth, cobalt, manganese, nickel, magnesium, molybdenum, titanium, vanadium, zirconium, hafnium, thorium and others, in the form of salts of inorganic acids, organic acids, complex compounds, preferably soluble or emulsifiable in water. It is possible to use salts of alkali metals or alkaline earth metals, such as acetates, lactates, naphthonates, oltrates, phenolates and the like. Very often, a synergistic effect is observed in mixtures of mainly amines and amino alcohols with compounds of the above-mentioned metals. The concentration in the catalyst ranges from 0.005 kg/m^ to 10 kg/m^.

Softeners include products of polyaddition of ethylene oxide to alkanolamines, higher aliphatic amines, higher fatty acids or alcohols (commercially available as Syntamin OC, Slovaviv K, Slovaviv FG, Soromin SG). The concentration of the softening agent is usually in the range of 2 to 60 kg/nP of solution.

Cellulose material, for example vicose staple, is wetted with the solution prepared in this way

201 105 or a cellulose derivative staple, wherein the crosslinking modulus, i.e. the amount of crosslinking solution: amount of staple, ranges from 1:10 to 40, preferably 1:20, and the crosslinking solution is applied at a temperature of 20 to 100 °C, preferably 60 °C. The excess solution obtained by centrifuging or dewatering the wet staple is recycled again, and the staple is dried to constant weight at a temperature of 20 to 60 °C and subjected to a heat treatment at a temperature of 90 to 130 °C for 5 min. to 3 hours, depending on the temperature and the desired degree of crosslinking.

The advantage of our process is, first of all, the easy, undemanding preparation of the modifier from commercially available raw materials, its applicability from aqueous solutions, which significantly improves the technology and makes the entire process more efficient, and last but not least, safety and hygiene of work due to the exclusion of highly toxic isocyanates, especially in the heat treatment process. The crosslinker solution is easily regenerated. Materials prepared in this way have improved physical and mechanical properties, such as conditioned and wet strength, reduced hydrophilicity, increased dyeability, etc., as well as other useful properties. Crosslinking or modification also withstands multiple decoctions.

Example 1

In a 2000 ml three-necked flask, 100 g of disodium bisulfite are dissolved in 128 ml of water at 60 °C while stirring. 84 g of hexamethylene diisocyanate are gradually added from a separating funnel and after the addition is complete, the reaction is allowed to proceed for 1 hour at 60 °C. The sulfoxamic acid solution is then heated to 85 °C and 1000 ml of sodium hydroxide are slowly added dropwise. After all the NaOH has been added, a fine suspension is formed, which is filtered. The filter cake is washed with 5 5” NaCl until there are no S0^ “ ions in the filtrate. After washing with the NaCl solution, the filter cake is washed with acetone and allowed to dry. This product is then used as a crosslinking agent.

Example 2

The procedure is as in Example 1, with the difference that the filter cake is no longer permeated with acetone, but is used directly as a crosslinking agent in the form of a paste.

Example 3

The procedure is as in Example 2, with the difference that instead of hexamethylene diisocyanate, toluene diisocyanate is used in an amount of 92.5 g.

201 185

Example 4

The procedure is as in Example 2, with the difference that instead of toluene diisocyanate, triphenylmethane-4,4',4-triisocyanate is used in an amount of 195 B dissolved in 300 g of acetone.

Example 5 g of hydroxyethyl cellulose staple is moistened at a temperature of 60 °C with 400 ml of a solution of a mixture of crosslinker, 0.1 g of emulsifier (Slovasol SF), 2 g of SnCl^, 0.5 B of triethanolamine, 12 g of fabric softener (Syntamin 0C), 0.4 g of urotropine. The solution is heated for 1 to 2 minutes with stirring to act on the staple. The staple is finally centrifuged, dried at 60 °C to constant weight and finally heat-treated for 2 hours at a temperature of 100 °C. The actual crosslinker is a paste of hexamethylenedihydroxyacid containing 40 wt. of water.

The properties of the modified staple depending on the crosslinker content compared to the unmodified staple are shown in Table 1.

Indicator Thickness* dtex ^P k ^{Memory x} to 5i η % ^P sl oN/dtex SN $ dix/dtex Unmodified with triž 2.09 1.94 0.61 12.1 23.0 0.72 215 Stretch modified with crosslinker paste 8 g/400 ml 1.90 2.05 0.67 10.7 15.7 0.65 171 - » - 16g/400ml 1.88 1.92 0.71 10.7 19.2 0.67 126 - - 24g/400ml 2.33 1.68 0.55 11.6 18.7 0.40 165 - - 32g/400ml 2.09 1.98 0.56 10.8 15.5 0.47 172 . - - 40g/400ml 2.09 2.07 0.70 10.6 17, ‘i 0.50 174

Example 6

Modified hydroxyethyl cellulose staple with values

air-conditioned fortress 1.92 oN/dtex wet strength = 0.71 oN/dtex ductility conditioned » 10.7 + wet ductility 19.2 $ loop strength « 0.67 oN/dtex secondary swelling e 126%

prepared according to the procedure in Example 5 was subjected to neutral & alkaline broth.

201 185

The values of the triple boiling 3x1 hour at 90 °C in water and 90 °C in 0.1% NaHCO^ are in Table 2.

Table 2

^P k oN/dtex ^P m oN/ dtex T ^A k * ^T m m * ^P sl oN/dtex SN me 3x1 hour neutral broth 1.91 0.71 10.8 '19.3 0.69 124 3x1 hour alkaline broth 1.92 0.76 10.4 19.4 0.66 122

SUBJECT OF THE INVENTION

Claims (1)

The values of the triple vial of 3x1 hr at 90 ° C in water and 90 ° C in 0.1 N NaHCO 3 are in Table 3. Table 2 Pk oN / dtex Pm oN / dtex Ť * k * m t * Psl oN / dtex SN £ 3x1 hr non-uniform brew 1.91 0.71 10.8 '19, 3 0.69 124 3x1 hr al-alkaline brew 1.92 0.76 10.4 19.4 0.66 122 BEFORE METHOD OF THE INVENTION A process for producing modified materials based on cellulose or derivatives thereof by treating at least one organic substance containing 1 to 4 hydroxamic acid functional groups in a molecule on cellulosic material or cellulose derivative materials, in the presence of auxiliaries, emulsifiers and catalysts, characterized in that the cellulose base materials or derivatives thereof, preferably in the form of fibers, are treated with a crosslinking solution containing 0.002 wt. % to 10 wt. hydroxamic acid, preferably in the form of a reaction product prepared from sulfoxamic acid of the corresponding organometallic compounds containing the same number of -NCO groups in the molecule, 0.01-0.5% by weight; emulsifier, 0.0005 µm wt. to 1 wt. catalyst and 0.2 to 6 wt. the conditioning process, the subsequent drying and heat treatment of the modification material is part of the modification process.