摘要:
The invention is concerned with a process for the production of cellulose moulded bodies wherein a suspension of cellulose in an aqueous solution of a tertiary amine-oxide is transformed into a mouldable solution, said solution being extruded by means of a forming tool and conducted into a precipitation bath. The process is characterized in that at least part of the materials in devices and pipes for the transportation and processing of the solution, which material is in contact with the mouldable solution contains at a minimum of 90% up to a depth of at least 0,5 .mu.m, preferably more than 1 .mu.m, at least one element of the group consisting of titanium, zirconium, chromium and nickel in elementary form and/or in the form of compounds provided that the remaining of the material does not contain any of the elements of the group consisting of copper, molybdenum, tungsten or cobalt. By means of the use of certain elements and compounds according to the invention, it is possible to control the occurrence and the extent of exothermal degradation reactions in the cellulose solution.
摘要:
The invention is concerned with a process for the production of cellulose moulded bodies. In this process, cellulose is first dissolved in an aqueous solution of a tertiary amine-oxide, in particular N-methylmorpholine-N-oxide (NMMO), to produce a mouldable cellulose solution. Second, the cellulose solution is molded and conducted into an aqueous precipitation bath, wherein the cellulose is precipitated, which produces a moulded body and a spent precipitation bath. Next, the spent precipitation bath is regenerated. This regenerated aqueous amine-oxide solution is re-used to dissolve cellulose, thereby repeating the process. In the above process, the repeated aqueous amine-oxide solution has a pH within certain defined limits.
摘要:
The invention is concerned with a process for the production of an aqueous amine-oxide solution used in the amine-oxide process for the production of a mouldable cellulose solution, wherein aqueous, amine-oxide containing solutions produced in said amine-oxide process particularly as precipitation baths are purified and concentrated, characterized in that a microbiocide agent is added to said aqueous, amine-oxide containing solutions before, during or after purification.
摘要:
The invention is concerned with a process for transporting a solution of cellulose in an aqueous tertiary amine-oxide through a component wherein said cellulose solution has different flow rates in said component, characterized in that an outlet wherethrough part of said cellulose solution is discharged from said component is provided at a point within said component whereat said flow rate is relatively low. (FIG. 2)
摘要:
Moulding material and spinning material respectively containing cellulose, an aqueous tertiary amine-oxide, a non-solvent and a stabiliser, characterised in that, one or more stabilisers are provided which altogether have a basic and antioxidant action with the proviso that the basic stabiliser is not phosphate. The moulding material and spinning material respectively according to the invention are thermally stabilised against a runaway of the decomposition reaction. The degradation of the cellulose and of the amine-oxide is also largely prevented.
摘要:
A process for the purification of aqueous solutions of amine-oxides, characterized in that said solutions are contacted with an aqueous purification solution of an alkali hydroxide and/or ion pair reagent by means of an anion active membrane. By means of the process according to the invention, an efficient separation, particularly of anions of lower carboxylic acids and inorganic acids, can be achieved.
摘要:
Moulding material and spinning material respectively containing cellulose, an aqueous tertiary amine-oxide, a non-solvent and a stabiliser, characterised in that, one or more stabilisers are provided which altogether have a basic and antioxidant action with the proviso that the basic stabiliser is not phosphate. The moulding material and spinning material respectively according to the invention are thermally stabilised against a runaway of the decomposition reaction. The degradation of the cellulose and of the amine-oxide is also largely prevented.
摘要:
The invention is concerned with a process for the production of a solution of N-methylmorpholine-N-oxide in water, characterized by the following steps:(a) providing an aqueous solution containing N-methylmorpholine and morpholine and exhibiting a pH value of from 6.0 to 9.0, thereafter(b) treating said aqueous solution with a peroxidic oxidant to oxidize N-methylmorpholine to N-methylmorpholine-N-oxide.
摘要:
The invention is concerned with a process for the selective separation of morpholine from an aqueous solution containing morpholine, N-methylmorpholine and N-methylmorpholine-N-oxide, characterized by the following steps:(A) passing said aqueous solution over a cation exchanger capable of adsorbing morpholine in such an amount until it cannot be charged substantially with morpholine any more and an eluate substantially free from morpholine but containing N-methyhnorpholine and N-methylmorpholine-N-oxide is obtained, and(B) regenerating the cation exchanger charged with morpholine and reusing it in step (A).
摘要:
The present invention relates to the use of a multilobal cellulosic staple fiber as a filling fiber. Furthermore, the invention relates to a cellulosic staple fiber which is characterized in thatthe cross-section of the fiber has three or more lobesthe titer of the fiber is 1.0 to 30 dtex, preferably more than 3.0 dtex, especially more than 5.0 dtex, preferably 5.6 to 10 dtex, especially preferred more than 6.0 dtex, especially 6.3 to 10 dtexthe wet modulus of the fiber fulfils the following formula:Wet modulus (cN/tex)≧0.5*√IT wherein T is the titer of the fiber in dtexthe breaking strength of the fiber in the conditioned state fulfils the following formula:Breaking Strength (cNitex)≧1.3*√T+2*T wherein T is the titer of the fiber in dtex.