CS210219B1 - A simple preparation of viacosis with reduced viscosity - Google Patents

Abstract

The invention aa relates to the preparation of cellulose from a mixture of alkaline celluloses from wood pulp and regenerated cellulose, for example from waste cellulose fibres. With an inverse proportion of regenerated cellulose to native cellulose, the value of cellulose cellulose decreases and its filterability increases. atupna alpha cellulose in viacose but to increase the concentration of cellulose in viacose, while maintaining its original viscosity value.

Description

The invention relates to an epéeob for the preparation of viscose and reduced viscosity by sulphidation, to the elimination of cellulosic and carbon disulphides, wherein the mixture of alkaline oeluloses consists of prewashed alkali cellulose of wood or cotton pulp and Here, the addition of regenerated oellulose modifies the hepatitis virus, significantly affects its viscosity and decreases it depending on the amount of regenerated oellulose added to the non-active one.

There are several known methods for the preparation of wax from eamot regenerated oellulose, for example from waste oelophane according to U.S. Pat. No. 111,357, or from waste wax fibers according to U.S. Pat. No. 2,184,586. This viscose must be produced * and shipped * to a coagulary using an aamoathat line, or else it can be locked with other cellulose or cotton pulp. Moreover, for the production of viscose fibers, which is thus intended to treat their wasteful wastes of viscose fibers, this entails the installation of a wide range of relatively complex and machine equipment due to the relatively small amount of waste fibers which can be extracted and ranges from 3 to 7 phi of the total product.

The essence of the present epdeobe for the preparation of viscose and reduced viscosity is that in pre-aged alkaline cellulose from non-inert oelulose, for example from wood or cotton pulp, in an amount of 50 to 90 bw per cent and add dd 1 to 50 bw per cent uncoated oeluloses, for example from shortened viscose fibers of 2 to 5 mm in length, and the mixture eo homogenized by pulping at room temperature. of sodium for viscose.

An advantage of the proposed process is that by the addition of regenerated oellulose in the function of the fiber-forming modifier, it is possible to intentionally change, modify the quality and process of the viscose. There is no need for additional equipment for the preparation and epreoating of the viscose, since it is merely a separate preparation of alkaline oellulose which generally blends the mereerization of the regenerated oellulose in a crucible, by removing excess bottle solution, for example by pressing, weighing and conveying the cauliflower wherein the untreated alkaline cellulose from regenerated oellulose has been milled and the pre-aged alkaline cellulose from wood pulp 2mea.

The process of oelulose zentogenate non-viscose, its spinning, fiber pulping, fusing and spraying, and does it in a continuous process dilution. The viscose thus prepared has a reduced viscosity value depending on the amount of regenerated oellulose added. Each one percent of the added regenerated oellulose to the inactive apdaob then decreases the viscosity by a second by two seconds as measured by the drop of the metal ball. > u set * to the desired value, regulate the calculated amount of regenerated oellulose

The improved colloidal state of the so-formed viscose, i.e. with the addition of regenerated oellulose as a modifier, also permits coarse technological interventions in the preparation of viscose and its composition and low coarse technological intervention can be compensated by increasing the proportion of regenerated cellulose to maintain viscose viscosity. For example, with a gradual increase in the content of alpha oellulose in viscose, it is necessary to increase the proportion of regenerated oellulose and decrease the proportion of native cellulose so that the viscosity value of the viscose does not increase too much. the viscose would become difficult to handle or even be difficult to handle. Annex 1 shows, among other things, a tabular representation of the increase in the viscosity of native cellulose viscose from 4 seconds! up to 135 aecand when alpha-cellulose content in viscose increases from 8.1 weight percent to 10 weight percent In contrast, increasing the viscosity of the viscose from a mixture of native and regenerated cellulose is no longer so dependent on an increase in the content of alpha cellulose in viscose but more added regenerated oellulose to the native. The note then always shows the appropriate amount of regenerated cellulose added to the native.

The regenerated cellulose represents precipitated oelulose from its solutions, for example from a meso-alcellous solution, from a zinc chloride, calcium rodanide solution, or from solutions of a labile oellulose derivative, for example from a solution of oellulose xanthate, increased reactivity, since reagents such as sodium bottle and carbon disulfide readily penetrate into it. It also swells in flushed bottle solutions. This is because of its modifying effect, since xentogenate from regenerated oellulose swells faster and more when dissolving than native oellulose zantogenate, thus helping to uniformly moisten and further dissolve into viscose with reduced viscosity.

For economic reasons, it is advisable to experience regenerated oelulose, found in and in the waste fibers and textiles. Before preparing the alkaline cellulose from it, it is necessary to first disintegrate approximately 2-5 mm in length, then mix it without difficulty with the pre-aged wood pulp alkaline cellulose. However, nothing is in the Czech Republic when regenerated cellulose formations other than fibers are used. Of the oellulose solutions, oellulose can be simply precipitated in tiny particles, for example by agitated mixing during the addition of the oellulose solution to the precipitant solution. Preferred are porous particles and regenerated oellulose formations because they are capable of incorporating into the ee * and in the caustic solution; this advantage and greatly applies during the dissolution of the xanthogenate mixture, which is thus grooved and evenly mixed with the dissolving liquor and not up to the diluted viscose.

Also suitable for this purpose are high-suction products of regaoserized cellulose modified by the addition of other polymers by compounding, for example, bydrophilic cellulose derivatives, starch and derivatives thereof, polyacrylic acid and salts thereof, acrylic acid and methacrylic acid copolymers. By admixture with these compounds, present in the regenerated oelulose in a nw of 5-35 per cent by weight of the penetrants, the aavoati is up to two-fold higher than the aavoati of the regenerated ellotosis oelulose.

Example 1

270 kg of Rauma RK wood pulp are soaked in a hydraulic bottle in a 60 gallon dipping bottle of 230 g / l NaOH for 60 minutes at a temperature of 19 ° C. Then, the formed alkaline oelfclose aa is pressed to 696 kg of alkali oelulose, and it is rolled and preheated for 3 hours aa until the average degree of polymerization of the oelulose is reached in it

350 kg of regenerated oellulose, i.e. a 4 mm long viscose dough, and a 30 minute ball with a 13θ liter soak bottle with a concentration of 230 g / l NaOH and a temperature of 19 ° C. Mixing aa is carried out in a mixing boiler equipped with a mixing device and an outlet opening, which is then discharged by the alkali oellulose duck into an oanthrophage to remove excess bottle solution. It also weighs 50 kg of alkali oelulose, which is then passed in a Parkina Baker pulper and 696 kg of pre-aged Rauma RF pulp alkali. Mixing of allcaliocellic oeluloses and starting 15 minutes at 25 ° C

The resulting cellulosic cellulosic product was poured into a sulphidation drum where aa then sulphide and 82 kg of carbon disulphide at 26 ° C for two hours. It also dissolves in a 2,000 liter solution of a 37 g / l NaOH solution for viscose and a viscosity of 39 aecand in two hours.

For comparison: Alucinous pulp and that composition have a viscosity of 49 seconds}

Example 2 g of viscose fibers, cut to 4 mm in length, and soaked for 30 minutes in a bottle solution of 230 g / l NaOH and at a temperature of 20 ° C. Then, a thin kata of alkali oelulose is aspirated on a Bflehner funnel. The aspirated alkaline oellulose has the shape of a sponge, and it is aa wrapped in a cotton pad, and is still topped up to bring the weight * of the sponge to 200 g.

The crushed alkali oelulose pulp of viscose fibers and then added to the spinner to 3000 g of pre-alkali alkali oelulose made from predator herb, containing 1000 g of alpha-cellulose and 451 g of NaOH. In the pulper, the alkali-oeluloses are blended for 10 minutes at 20 ° C. Another thiolologic mist is sulphide of the alkali-oeluloses mixture and is carried out for 2 hours at 26 ° C in a sulphurization drum. On the sulfide, aa gives 355% of carbon. .

The resulting o-cellulose xanthogonate was dissolved in 8,650 g of diluted bottle solution containing 315 g of NaOH in 3 hours. The temperature of the bottle solution was 12 ° C and contained 8.6% alpha cellulose and 6.5% NaOH. Its viscosity value is 53 aecand.

By way of comparison, a viscose of that composition, prepared from wood pulp, has a viscosity of 67 aecand, ie 14 aecand is poured out.

The invention is more versatile and is characterized by the fact that viscose fibers and viscose textiles can be treated in this way, but also other products made of waxose or regenerated oellulose can be processed. various technological interventions, such as increasing alpha cellulose content in viscose, reducing NaOH content in viscose, reducing the amount of carbon disulphide for sulfidation, increasing the average polymer degree of cellulose

From these gases different economic and technical advantages. From technical advantages, it can be mentioned that, for example, by increasing the elongation of the cellulose in the viscose, fibers are obtained with a drop in primary wetting value; specifically in viscose coagulation with 10% alpha oelulose and a fiber having a primary wetting value of 2.16

By increasing the average polymeric grade of cellulose in viscose thus prepared, new types of fibers can be made therefrom, the viscose being less viscous because of its lower viscosity than the viscose of eamotive native cellulose. For more demanding high-strength fiber types it is possible such viscose eSte also other active agents, with or without surface activity, which modify, modify the resistance of the viscose to coagulation

Claims (1)

OBJECT OF THE INVENTION A process for the preparation of viscose with reduced viscosity by sulfidating a mixture of alkaline celluloses with carbon disulphide, characterized in that from 1 to 50% by weight is added to the pre-matured cellulose from native oelulose, for example wood or cotton pulp, in an amount of 50 to 90% by weight. % of untreated alkaline cellulose from regenerated oellulose, for example from shortened viscose fibers having a length of 2 to 5 mm, the mixture is homogenized by pulping at room temperature, and the thus prepared mixture of alkaline celluloses is sulfidated with carbon disulphide.