THE USE OF ETHOXYLATED FATTY AMIDO ALCOHOLS AS A REACTIVITY ADDITIVE IN THE PROCESS WHEREIN CELLULOSE IS REACTED WITH LYE

Abstract

The present disclosure relates to the use of alkoxylated fatty amido alcohols in the process to make viscose wherein cellulose is reacted with lye and the lye strength is from about 8 to about 20% by weight of NaOH, based on the weight of water in the reaction mixture. The use as a reaction improvement additive improves the reaction rate between the cellulose and the lye. The use also improves the reaction between alkali-cellulose and CS.sub.2. The present disclosure also relates to solid cellulose that is treated with one or more ethoxylated fatty amido alcohols and which is suitable for use in the claimed process.

Claims

1. Process wherein about 0.005 to about 2.0% by weight of an alkoxylated fatty amido alcohol is added to a cellulose pulp during or before reacting the cellulose with a lye, whereby the lye strength is from about 8 to about −20% by weight of NaOH, based on the weight of water in the reaction mixture, and the weight of the alkoxylated fatty amido alcohol is based on the weight of the cellulose, whereby about 80% or more, on a molar basis, of the alkoxy groups are ethoxy.

2. Process of claim 1 wherein the alkoxylated fatty amido alcohol is of the formulae alkyl-CONH—C.sub.2H.sub.4O-(AO).sub.x—H, and alkyl-CON—(C.sub.2H.sub.4O-(AO).sub.x/2—H).sub.2, or comprises a mixture thereof, wherein alkyl-CO is the residue of a fatty acid with, on average, from about 8 to about 24 carbon atoms per acid moiety, and x, on average, is from about 2 to about 15.

3. Process of claim 2 wherein x, on average, is from about 5 to about −12 and alkyl-CO is a residue of a fatty acid with, on average, from about 8 to about 14 carbon atoms.

4. Process of claim 2 wherein x, on average, is from about 5 to about −9.

5. (canceled)

6. (canceled)

7. (canceled)

8. (canceled)

9. (canceled)

10. (canceled)

11. (canceled)

12. (canceled)

13. Viscose obtained by a process comprising the process of claim 1.

14. A solid cellulose composition comprising cellulose and from about 0.005 to about 2.0% by weight of alkoxylated fatty amido alcohols, based on the weight of the cellulose, whereby about 80% or more, on a molar basis, of the alkoxy groups are ethoxy.

15. A solid cellulose of claim 14 wherein the alkoxylated fatty amido alcohol is of the formula alkyl-CONH—(C.sub.2H.sub.4O).sub.x+1H, alkyl-CON—((C.sub.2H.sub.4O).sub.(x+1)/2H).sub.2, or comprises a mixture thereof, wherein alkyl-CO is the residue of a fatty acid with about 8 to about 24 carbon atoms per acid moiety, and x, on average, is from about 2 to about 15, whereby about 80% or more, on a molar basis, of the alkoxy groups are ethoxy.

16. A solid cellulose of claim 15 wherein x, on average, is from about 5 to about 12 and alkyl-CO is a residue of a fatty acid with, on average, from about 8 to 14 carbon atoms.

17. A solid cellulose of claim 15 wherein x, on average, is from about 5 to about 9 and wherein the alkoxylated fatty amido alcohol is a coco ethanolamide that is ethoxylated with about 8 moles of ethylene oxide.

18. Process of claim 1 wherein the alkoxylated fatty amido alcohol is coco monoethanolamide ethoxylated with from about 2 to about 15 moles of ethylene oxide.

19. Process of claim 1 wherein the alkoxylated fatty amido alcohol is coco monoethanolamide ethoxylated with 2 moles of ethylene oxide.

20. Process of claim 1 wherein the alkoxylated fatty amido alcohol is coco monoethanolamide ethoxylated with 5 moles of ethylene oxide.

21. Process of claim 1 wherein the alkoxylated fatty amido alcohol is coco monoethanolamide ethoxylated with 8 moles of ethylene oxide.

22. Process of claim 1 wherein the alkoxylated fatty amido alcohol is coco monoethanolamide ethoxylated with 12 moles of ethylene oxide.

23. Process of claim 1 wherein the alkoxylated fatty amido alcohol is coco monoethanolamide ethoxylated with 15 moles of ethylene oxide.

24. Process of claim 1 wherein the alkoxylated fatty amido alcohol is coco diethanolamide ethoxylated with from about 8 to about 12 moles of ethylene oxide.

25. Process of claim 1 wherein the alkoxylated fatty amido alcohol is coco diethanolamide ethoxylated with 8 moles of ethylene oxide.

26. Process of claim 1 wherein the alkoxylated fatty amido alcohol is coco diethanolamide ethoxylated with 12 moles of ethylene oxide.

27. Process of claim 4 wherein the alkoxylated fatty amido alcohol is a coco ethanolamide that is ethoxylated with about 8 moles of ethylene oxide.

Description

DETAILED DESCRIPTION

[0019] The following detailed description is merely exemplary in nature and is not intended to limit the present disclosure or the application and uses of the present disclosure. Furthermore, there is no intention to be bound by any theory presented in the preceding background of the present disclosure or the following detailed description.

[0020] The present disclosure relates to the use of ethoxylated fatty amido alcohols in the process to make viscose. In one embodiment the present disclosure relates to the use of ethoxylated fatty amido alcohols as a reaction improvement additive for the reaction between cellulose and a lye. In one embodiment the present disclosure relates to the use of ethoxylated fatty amido alcohols as a reaction improvement additive for making alkali-cellulose that subsequently can be reacted with and CS.sub.2, whereby the xanthated product has an improved (lower) clogging value. Another embodiment relates to cellulose that is treated with one or more ethoxylated fatty amido alcohols which is suitable for reaction with lye, preferably in the process to make viscose.

[0021] The ethoxylated fatty amido alcohols of the present disclosure are suitably produced by first reacting a fatty acid or its ester, typically an ester with a C1-6 alcohol, with ethanolamine or diethanolamine to form a product of the formula alkyl-CONH—C.sub.2H.sub.4OH, which is subsequently reacted with ethylene oxide. The process is discussed in in A. Lif and M. Hellsten, Nonionic Surfactants Containing an Amide Group, in Surfactant Science Series, Vol. 72, Marcel Dekker NY, 1998, pp 177-185. Typically the reaction of acid (ester) and ethanolamine is optimized to maximize the amount of fatty alkanol amide glycol ether, for instance by employing dosing the ethanolamine to the fatty acid under reaction conditions.

[0022] Suitable fatty acids are those acids with from about 8 to 24 carbon atoms per acid moiety. In the disclosure, suitably a fatty acid is used with, on average, from about 8, about 9, or about 10 up to about 24, about 22, about 20, about 18, or about 14 carbon atoms per carboxylic acid moiety. In an embodiment it is the residue of coco fatty acid which is the fatty acid from coconut oil and is a mixture of various fatty acids, predominantly about C8-C18 fatty acids, with the majority being about C12-C14 fatty acid, i.e. lauric and myristic acid. The fatty acids are mostly saturated but some unsaturated fatty acids, such as oleic acid, may be present. In an embodiment the alkyl moiety of the formula comprises more than about 50% by weight of about C11-C13 alkyl groups.

[0023] In the ethoxylation step, 1 mole of alkyl-CONH—C.sub.2H.sub.4OH, alkyl-CON—(C.sub.2H.sub.4OH).sub.2, or a mixture thereof, is reacted with x moles of ethylene oxide wherein x is the, average, degree of ethoxylation and wherein alkyl-CO is the residue of a fatty carboxylic acid, as described above. In one embodiment x is at least about 2, about 3, about 4, or about 5 with a maximum of about 15, about 14, about 13 or about 12. In an embodiment x is greater than about 5. In another embodiment x is in the range of from about 5 to about 9. In an embodiment x is from about 5 to about 12 with alkyl-CO, on average, having a total of carbon numbers up to about 14.

[0024] It is noted that instead of about 100% ethylene oxide, the ethoxylation can also be performed with mixtures of ethylene oxide, propylene oxide, and/or butylene oxide. Also the reaction can be with ethylene oxide, propylene oxide, and/or butylene oxide in separate steps to form a product with a somewhat blocky alkoxylation. All of these products can be represented by products of the formulae alkyl-CONH—C.sub.2H.sub.4O-(AO).sub.x—H and alkyl-CON—(C.sub.2H.sub.4O-(AO).sub.x/2—H).sub.2, whereby AO stands for alkyloxide. Suitably the mixtures of oxides comprise, on a molar basis, at least about 80% ethylene oxide. The resulting products are herein all labeled as ethoxylated fatty amido alcohols.

[0025] In an embodiment these ethoxylated fatty amido alcohols are used in the process to make viscose. They were found to improve the reaction rate of both the reaction of cellulose with lye and the reaction of alkali-cellulose with CS.sub.2, without adverse affecting the resulting viscose or the spinning process. Hence the products are herein also referred to as reactivity agents.

[0026] Without being bound by this theory, it is believed that the reactivity agent is partly precipitating on the cellulose surface when a concentrated lye solution (such as a from about 15 to about 20%, typically about 18% w/w NaOH solution in water) is added to an aqueous medium comprising amide and cellulose. The presence of the reactivity on the surface of the cellulose then makes the OH groups of the cellulose more readily available for reaction with the lye, and subsequently with CS.sub.2. However, the reactivity agent goes back in solution when the lye becomes less concentrated, so that it can be washed away after the cellulose is reacted with CS.sub.2, and therefore the spinning process to make viscose fibre is not disturbed. However, the actual mode of action of the (precipitated) reactivity additive in combination with the lye strength as claimed is also unknown. Speculations have it that the additive reduced cellulose crystallization and serves as a swelling enhancer, also for alkali-cellulose to make the reactive sites more easily accessible for the CS.sub.2, and/or a phase transfer catalyst.

[0027] Suitably the amount of reactivity agent used in the process is from about 0.005, about 0.01, about 0.015, about 0.02, about 0.05, or about 0.1 up to about 2.0, about 1.5, about 1.0, about 0.5 or about 0.2% by weight, based on the weight of the cellulose.

[0028] The lye which is reacted with the cellulose is aqueous and usually a NaOH solution, but other alkaline agents, including KOH, can be used. The concentration of the lye can be kept constant or it can be allowed to lower in the course of the reaction with the cellulose or the reaction can be in multiple steps where the concentration of the lye is varied. Suitably the lye strength is equal to a solution of from about 8 to about 20% w/w of NaOH. In an embodiment in one step the lye strength is equal to a solution of from about 8 to about 14% w/w NaOH during at least part of the alkalization. In another embodiment the lye concentration is strength is equal to a solution of about 16 or about 17 up to about 19 or about 20% w/w NaOH during at least part of the alkalization. In an embodiment the lye strength is equal to a solution of about 16 or about 17 up to about 19 or about 20% w/w NaOH in a first step and equal to a solution of about 4 or about 5 up to about 10 or about 14% w/w NaOH in a second step of the alkalization process. At those concentrations the lye is typically not fully dissolved in the reaction mixture. According to the unproven theory it is the combination of lye strength and reactivity additive that makes the mercerization process of the present disclosure so effective.

[0029] The reaction temperature can be from ambient or about 15° C. up to about 60° C., depending on desired reaction rates and whether or not controlled degradation (ageing) of the cellulose is desired. Suitably the reaction with lye is performed at a temperature between about 35° C. and about 50° C. Typical reaction times, depending on temperature and concentration are from about 1 to about 3 hours, suitably about 1 hour.

[0030] The alkali-cellulose is reacted with CS.sub.2 in a conventional way. Suitable the reacting mass contains from about 25 to about 35% w/w CS.sub.2, based on the weight of the cellulose. Suitably the reaction with CS.sub.2 is performed at a temperature between about 15° C. and about 60° C. Also a reaction temperature between about 20 and about 35° C. has been reported. Suitably the reaction time is from about 30 minutes to about 4 hours, typically about 2 hours. CS.sub.2 can be added all at once, in portions, continuous for a certain time period, or combinations thereof.

[0031] In an embodiment the temperature during alkalization and the reaction with CS.sub.2 (xanthation) is at about the same temperature (a difference of less than about 10° C. In an embodiment part of the alkalization is carried out simultaneous with the xanthation reaction.

[0032] The xanthate showed good filterability and very little gel-like particles, so good clogging value, allowing good processing in the spinning process and good viscose fibre quality. Typically the regenerated cellulose fiber is suitably washed, to remove ethoxylated fatty amido alcohol.

[0033] When a ratio or amount is given, it is by weight, unless mentioned differently.

[0034] An increase of a parameter is considered to be absent if the numerical value of the relevant property is not increased or increased with less than about 10%.

[0035] The present disclosure will now be illustrated by the following non-limiting examples. Throughout this document, unless indicated differently, the weight percentages of the compositions are based on the total weight of the composition, whereby the total weight of the composition is about 100 wt %. The term water-soluble is used for materials that dissolve in an amount of at least about 1 g per liter of demineralized water at about 25° C. Where used, the term “consisting” also embraces “consisting substantially”, but may optionally be limited to its strict meaning of “consisting entirely”.

[0036] Throughout the description and claims of this specification, the words “comprise” and “contain” and variations of the words, for example “comprising” and “comprises”, mean “including but not limited to”, and do not exclude other moieties, additives, components, integers or steps. Moreover the singular encompasses the plural unless the context otherwise requires: in particular, where the indefinite article is used, the specification is to be understood as contemplating plurality as well as singularity, unless the context requires otherwise.

[0037] Where upper and lower limits are quoted for a property, for example for the concentration of a component, then a range of values defined by a combination of any of the upper limits with any of the lower limits may also be implied.

[0038] It will also be appreciated that features from different aspects and embodiments of the present disclosure may be combined with features from any other aspect and embodiment of the present disclosure.

[0039] Although the present disclosure is illustrated and described herein with reference to specific embodiments, the present disclosure is not intended to be limited to the details shown. Rather, various modifications may be made in the details within the scope and range of equivalents of the claims.

EXAMPLES

[0040] In order to study the effect of a reactivity additive on the reaction between lye and cellulose the following method is used.

[0041] A reactivity additive stock solution with a concentration of 1% stock solution was prepared for accuracy.

[0042] Sheets of cellulose from the pulp mill were cut into 10 small circles with a diameter of 32.5 mm using a hammer and a punch. It is of great importance that they are perfectly circular with clear cut edges and that there is no contamination on the pulp. The 10 circles were then placed on a scale, the weight was recorded, and they were then placed horizontally inside a 250-ml measuring cylinder with an inner diameter of 34 mm, and the initial height of the sum of the stacked cellulose discs was recorded.

[0043] Into the cylinder enough of the additive stock solution was added to achieve a dosage of 0.2% by weight of the reactivity additive based on the weight of the cellulose (which amounts to 2 kg/ton). After 5 minutes (conditioning) the height of the stack of cellulose discs was recorded.

[0044] Subsequently 201.3 g of a NaOH solution with a concentration of 19.7% w/w (to reach a final concentration of 18 w/w % NaOH) was added to the cylinder. The height was recorded after 1, 2, and 10 minutes. If one or more of the cellulose discs starts to float, then a glass rod (weighing 11 grams) was carefully lowered on the floating cellulose discs and, using its own weight, used to carefully press down the pulp circles to allow for accurate measurements of the height of the pillar of swollen cellulose discs. Each analysis was done in triplicate.

Materials:

[0045] Water was demineralized water

[0046] Berol® Visco 388, a conventional reactivity additive based on polyoxy ethylene glycol, was supplied by AkzoNobel

Coco monoethanolamide ethoxylated with 2, 5, 8, 12, or 15 EO molecules per mole was produced in a conventional way by reacting coco methyl ester with monoethanolamine. The reaction product (fatty alkanol amide glycol ether) was purified before reacting it with the indicated from about 2-15 moles of EO per mole of the ether. The resulting product was washed and dried.

[0047] Coco diethanolamide ethoxylated with, on average, 8 and 12 EO molecules per mole was produced in a conventional way by reacting coco methyl ester with diethanolamine. The reaction product (fatty alkanol amide glycol ether) was purified before reacting it with 8 or 12 moles of EO per mole of the ether. The ethoxylated fatty amido alcohol was sprayed as a 1.3% solution in water onto a cellulose pulp sheet, where after the treated sheet was dried for 48 hours at ambient temperature. These sheets were processed as indicated above.

[0048] Results: The table shows the swelling over time of the pulp circles as measured in millimeters with the standard deviation from the three trials noted.

TABLE-US-00001 Height of pulp pillar (mm) over a total time (minutes) of Additive 0.2 % w/w 0 5 6 7 15 Only Water (reference) 15 22 50 ± 2 61 ± 4  96 ± 3 Berol Visco 388 (reference) 15 22 62 ± 2 70 ± 3 105 ± 2 Coco monoethanolamide with 2 15 23 64 ± 2 72 ± 2 104 ± 3 moles of EO Coco monoethanolamide with 5 15 21 67 ± 2 75 ± 3 111 ± 2 moles of EO Coco monoethanolamide with 8 15 22 69 ± 3 77 ± 3 117 ± 3 moles of EO Coco monoethanolamide with 12 15 22 68 ± 3 77 ± 4 112 ± 4 moles of EO Coco monoethanolamide with 15 15 21 64 ± 2 71 ± 2 107 ± 3 moles of EO Coco diethanolamide with 8 15 20 69 ± 3 79 ± 5 120 ± 5 moles of EO Coco diethanolamide with 12 15 22 68 ± 2 78 ± 3 114 ± 4 moles of EO

[0049] The better swelling gave better accessibility of the OH groups of the cellulose and therefore led to a more efficient alkalization in the process to make viscose.

[0050] The resulting alkalicellulose was found to react with CS.sub.2 in a complete manner at 28° C. for 1.5 hours, leading to very little unreacted (alkali)cellulose in the xanthated product. This was analysed for by dissolving 8.5 weight % of xanthate in an aqueous 6% NaOH solution for 2 hours at 10° C., followed by ripening for 24 hours at 20° C. of the viscose and how much filtrate flows from a filter holding said unfiltered solution at 20° C., after pressurization with 2 bars, during the first 20 minutes (a) and the next 40 minutes (b). The clogging value Kw is then proportionate with (2−b/a)/(a+b) with a lower value being preferred.

TABLE-US-00002 Additive 0.2 % ww Clogging Kw Only Water (reference) 2570 Berol Visco 388 (reference) 1920 Coco monoethanolamide with 8 moles of EO 1403

[0051] The results show the improved quality of the xanthated product/viscose when a reactivity agent is used to facilitate the reaction of cellulose and lye under conditions as claimed. The data further shows that the reactivity agent facilitates the reaction of alkali cellulose and CS.sub.2 leading to a favorable cellulose xanthate.

[0052] While at least one exemplary embodiment has been presented in the foregoing detailed description, it should be appreciated that a vast number of variations exist. It should also be appreciated that the exemplary embodiment or exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration of the various embodiments in any way. Rather, the foregoing detailed description will provide those skilled in the art with a convenient road map for implementing an exemplary embodiment as contemplated herein. It being understood that various changes may be made in the function and arrangement of elements described in an exemplary embodiment without departing from the scope of the various embodiments as set forth in the appended claims.