U.S. patent application number 16/491401 was filed with the patent office on 2020-01-16 for fibre comprising composite fibres of cellulose and cellulose acetate.
The applicant listed for this patent is INNOVIA FILMS LIMITED. Invention is credited to David Malcolm LEWIS, Jamie MOFFAT, Marzena ZDZIARSKA.
Application Number | 20200018016 16/491401 |
Document ID | / |
Family ID | 58682542 |
Filed Date | 2020-01-16 |
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United States Patent
Application |
20200018016 |
Kind Code |
A1 |
MOFFAT; Jamie ; et
al. |
January 16, 2020 |
FIBRE COMPRISING COMPOSITE FIBRES OF CELLULOSE AND CELLULOSE
ACETATE
Abstract
The present invention provides a coloured fibre comprising one
or more composite filaments of cellulose and cellulose acetate,
wherein the colour is effected by a disperse dye.
Inventors: |
MOFFAT; Jamie; (Wigton,
Cumbria, GB) ; ZDZIARSKA; Marzena; (Wigton, Cumbria,
GB) ; LEWIS; David Malcolm; (Otley, West Yorkshire,
GB) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
INNOVIA FILMS LIMITED |
Wigton, Cumbria |
|
GB |
|
|
Family ID: |
58682542 |
Appl. No.: |
16/491401 |
Filed: |
March 29, 2018 |
PCT Filed: |
March 29, 2018 |
PCT NO: |
PCT/EP2018/058223 |
371 Date: |
September 5, 2019 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
D01F 1/06 20130101; D06P
3/79 20130101; D01F 2/02 20130101; D06P 3/52 20130101; D06P 3/42
20130101; D06L 4/12 20170101; D01F 2/28 20130101; D01F 2/06
20130101; D01F 8/02 20130101; D06L 4/10 20170101; D06P 3/6033
20130101; D01F 2/00 20130101; D06P 3/82 20130101; D06P 3/8233
20130101; D06P 3/24 20130101 |
International
Class: |
D06P 3/42 20060101
D06P003/42; D01F 1/06 20060101 D01F001/06; D01F 2/02 20060101
D01F002/02; D01F 8/02 20060101 D01F008/02; D06L 4/12 20060101
D06L004/12; D06P 3/60 20060101 D06P003/60; D06P 3/82 20060101
D06P003/82; D06P 3/24 20060101 D06P003/24; D06P 3/52 20060101
D06P003/52; D06P 3/79 20060101 D06P003/79 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 31, 2017 |
GB |
1705186.3 |
Claims
1. A coloured fibre comprising one or more composite filaments of
cellulose and cellulose acetate, wherein the colour is effected by
a disperse dye.
2. The coloured fibre according to claim 1, wherein the weight
ratio of the cellulose to the cellulose acetate in the composite
filaments is from 99:1 to 1:99, from 95:5 to 5:95, from 90:10 to
10:90, from 80:20 to 20:80, from 70:30 to 30:70, or from 60:40 to
40:60.
3. The coloured fibre according to claim 1, wherein the weight
ratio of the cellulose to the cellulose acetate in the composite
filaments is from 90:10 to 50:50, from 80:20 to 50:50, from 70:30
to 50:50, or from 60:40 to 50:50.
4. A fibre blend comprising fibres comprising one or more composite
filaments of cellulose and cellulose acetate; and synthetic fibres,
wherein the fibre blend is dyeable with a disperse dye.
5. A coloured fibre blend comprising fibres comprising one or more
composite filaments of cellulose and cellulose acetate; and
synthetic fibres, wherein the colour is effected by a disperse
dye.
6. The fibre blend according to claim 4, wherein the synthetic
fibres are selected from polyester fibres, nylon fibres, acrylic
fibres, elastane fibres, cellulose acetate fibres, cellulose
triacetate fibres, polylactic acid fibres, polypropylene fibres, or
polyphenylene sulfide fibres.
7. A process for manufacturing the coloured fibre of claim 1,
comprising: providing a solution dope comprising a blend of
cellulose and cellulose acetate in an ionic liquid or in
N-methylmorpholine-N-oxide; spinning the solution dope into a
coagulant to generate the fibres; and dyeing the fibres with a
disperse dye.
8. A process for manufacturing the coloured fibre of claim 1,
comprising: providing a solution dope comprising a blend of
cellulose and cellulose acetate in an ionic liquid or in
N-methylmorpholine-N-oxide; adding a disperse dye to the solution
dope; and spinning the solution dope with the disperse dye into a
coagulant to generate coloured fibres.
9. The process according to claim 7, wherein the ionic liquid is
selected from butyl-3-methylimidazolium chloride,
1-butyl-3-methylimidazolium acetate and 1-ethyl-3-methylimidazolium
acetate.
10. The process according to claim 7, wherein the ionic liquid is
selected from 1,1',3,3'-tetramethylguanidinine carboxylates,
1,8-diazabicyclo[5.4.0]undec-7-ene carboxylates and
1,5-diazabicyclo[4.3.0]non-5-ene carboxylates.
11. The process according to claim 7, wherein the solution dope
further comprises a co-solvent.
12. The process according to claim 11, wherein the co-solvent is
selected from dimethyl sulfoxide, dimethylformamide,
tetrahydrofuran, and dioxane.
13. The process according to claim 7, wherein the weight ratio of
cellulose to cellulose acetate in the solution dope is from 99:1 to
1:99, from 95:5 to 5:95, from 90:10 to 10:90, from 80:20 to 20:80,
from 70:30 to 30:70, or from 60:40 to 40:60.
14. The process according to claim 7, wherein the weight ratio of
cellulose to cellulose acetate in the solution dope is from 90:10
to 50:50, from 80:20 to 50:50, from 70:30 to 50:50, or from 60:40
to 50:50.
15. The process according to claim 7, wherein the solids content of
the solution dope is up to about 50% by weight, up to about 45% by
weight, up to about 40% by weight, up to about 35% by weight, up to
about 30% by weight, up to about 25% by weight, or up to about 20%
by weight.
16. The process according to claim 7, wherein the solids content of
the solution dope is from about 5% by weight to about 25% by
weight, or from about 10% by weight to about 20% by weight.
17. The process according to claim 7, wherein the coagulant
comprises water, methanol and/or ethanol.
18. A process for dyeing fibres comprising one or more composite
filaments of cellulose and cellulose acetate, comprising:
contacting the fibres with a disperse dye; and washing the dyed
fibres with water.
19. A process for dyeing the fibre blend according to claim 4,
comprising: contacting the fibre blend with a disperse dye; and
washing the dyed fibre blend with water.
20. A textile manufactured from the coloured fibres according to
claim 1.
21. A textile manufactured from the fibre blend according to claim
4.
22. A textile manufactured from the coloured fibre blend according
to claim 5.
23. A textile manufactured from fibres comprising composite
filaments of cellulose and cellulose acetate, and synthetic and/or
natural fibres, wherein the fibres comprising composite filaments
and the synthetic and/or natural fibres are provided in separate
yarn or thread.
24. A garment or soft furnishing made at least partly from the
textile of claim 20.
Description
[0001] This application is a national stage application of
International Patent Application No. PCT/EP2018/058223, filed Mar.
29, 2018, which claims priority to United Kingdom patent
Application No. 1705186.3, filed Mar. 31, 2017. The entirety of the
aforementioned applications is incorporated herein by
reference.
FIELD
[0002] The present invention relates to fibres. More specifically,
the present invention relates to fibres which can be dyed with a
disperse dye.
BACKGROUND
[0003] There are two distinct types of fibres used in the
manufacture of textiles, namely natural fibres, for example
cellulose fibres, and synthetic fibres, for example polyester,
nylon and cellulose acetate fibres.
[0004] An important step in the manufacture of fibres, particularly
those used in the manufacture of textiles, is the step of dyeing
the fibres.
[0005] Cellulose fibres are hydrophilic and are therefore commonly
dyed using water-soluble dyes such as acid dyes, direct dyes,
reactive dyes and sulfur dyes. Alternatively, cellulose fibres are
sometimes dyed using vat dyes. Vat dyes are essentially insoluble
in water and incapable of dyeing fibres directly. Instead,
reduction in alkaline liquor produces a water-soluble alkali metal
salt of the dye which has an affinity for the fibre. However, these
processes consume large volumes of water and generate significant
quantities of coloured aqueous effluent.
[0006] Synthetic fibres, such as polyester fibres, nylon fibres and
cellulose acetate fibres, tend to be hydrophobic and therefore have
poor affinity for the aqueous dyes outlined above.
[0007] Disperse dyes were developed in the 1920's for dyeing
cellulose acetate fibres. Disperse dyes tend to be hydrophobic,
non-reactive, traditionally non-ionic, dyes that are used as
surfactant-stabilised dispersions in water. Disperse dyes are often
selected from substituted monoazo or diazo compounds, anthraquinoid
compounds, and nitro or amino ketone compounds.
[0008] Disperse dyes have an excellent affinity for synthetic
fibres such as polyester, nylon and cellulose acetate. However,
conventional processes using disperse dyes are not used to dye
cellulose fibres due to the poor affinity of the hydrophobic
disperse dyes for the hydrophilic cellulose fibres.
[0009] Attempts have been made in the prior art to manipulate
cellulose fibres in order to improve their affinity for disperse
dyes.
[0010] For example, Canadian patent application number 1072260
describes a process for dyeing a cellulose fibre fabric using
disperse dyes, which includes reacting a cellulose fibre fabric
with an aromatic acylating agent having an acyl group to form a
cellulose derivative fabric having a substitution degree between
0.10 and 0.50, and transferring a disperse dye onto the fabric.
[0011] U.S. Pat. No. 5,298,032 describes a process for dyeing
cellulosic textile materials with disperse dyes from supercritical
CO.sub.2 by treating the textile materials with an auxiliary that
promotes dye uptake, such as a polyalkylene glycol, an alkanolamine
or an aromatic compound with several hydroxyl groups.
[0012] However, the additional steps required to render the
cellulose fibres suitable for dyeing with disperse dyes,
significantly increase the cost and complexity of the manufacturing
process.
[0013] Synthetic fibres offer many advantages over natural fibres,
for example synthetic fibres may be strong and light weight, fast
drying and/or resistant to wrinkles and creases. However, synthetic
fibres may be considered to have an unacceptable feel and/or
appearance for certain textile applications. To address this issue,
it is known to blend synthetic fibres with other synthetic or
natural fibres. Common examples of fibre blends include
polyester/cotton blends and polyester/viscose blends.
[0014] However, there are drawbacks associated with the use of
synthetic/natural fibre blends. In particular, synthetic/natural
fibre blends require more complex, multi-stage dyeing processes.
For example, a reactive dye may be used to dye the cellulose
component e.g. cotton or viscose, and a disperse dye may be used to
dye the polyester component. Dyeing times of up to 8 hours for such
fibre blends are not uncommon.
[0015] Attempts have been made in the prior art to simplify the
dyeing process of fibre blends.
[0016] For example, U.S. Pat. No. 3,706,525 describes a process for
dyeing water swellable cellulosic materials or mixtures or blends
thereof with synthetic materials, which includes contacting the
cellulosic material with water in any sequence with water in
sufficient amounts to swell the cellulose, a preformed dye of low
water solubility, and a dye solvent which is an ethylene glycol or
a polyethylene glycol, provided that at some stage during the
process the interior of the swollen cellulose is contacted with a
solution of the dye in aqueous dye solvent or dye solvent.
[0017] U.S. Pat. No. 3,713,767 describes a process for the dyeing
of textile materials consisting of mixtures of polyester fibres
with cellulose fibres, wherein the textile materials are treated
with an alkaline solution which contains a coupling component, a
disperse dyestuff and wetting or dispersing agents, dried and
subsequently treated with an acid solution which contains, in
addition to compounds having an acid reaction, a diazotized
aromatic or heterocyclic amine, dried and then subjected to a heat
treatment.
[0018] U.S. Pat. No. 5,695,375 describes a textile product
comprising regenerated cellulose fibres containing 10 to 40 weight
% of polymer fine particles with an average particle size of 0.05
to 5 .mu.m, which are dyeable with a disperse dye, and polyester
fibre.
[0019] However, the prior art processes for dyeing
natural/synthetic fibre blends still require complex, multi-stage
dyeing processes which result in an increase in manufacturing
costs.
[0020] There have also been attempts made in the prior art to
intimately combine synthetic and natural fibres to impart certain
characteristics of one type of fibre to the other.
[0021] U.S. Pat. No. 6,258,304 describes a process for the
preparation of lyocell fibre or film by extruding a solution of
cellulose in amine oxide through a spinneret or film die at
elevated temperature via an air gap into an aqueous precipitation
bath, thereby to form said fibre or film.
[0022] Our international application number WO2011/048420 describes
a biodegradable fibre comprising composite filaments of cellulose
and cellulose acetate, and a process for making such a fibre
comprising providing a solution dope comprising a blend of
cellulose and cellulose acetate in an ionic liquid or in
N-methylmorpholine (NMMO), and spinning the blend into a protic
solvent to generate fibres.
[0023] The present invention seeks to address the problems
associated with the prior art.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] The invention will now be more particularly described with
reference to the following non-limiting figures and examples.
[0025] FIG. 1: undyed fibres comprising composite filaments of
cellulose and cellulose acetate.
[0026] FIG. 2: a scanning electron microscopy image of an undyed
fibre comprising composite filaments of cellulose and cellulose
acetate.
[0027] FIG. 3a: a cotton fabric sample dyed with Colour Index
Disperse Violet 1.
[0028] FIG. 3b: a sample of the coloured fibres in accordance with
the present invention dyed with Colour Index Disperse Violet 1.
[0029] FIG. 4a: a cotton fabric sample dyed with Colour Index
Disperse Red 279.
[0030] FIG. 4b: a sample of the coloured fibres in accordance with
the present invention dyed with Colour Index Disperse Red 279.
[0031] FIGS. 5a to 5g: samples of fibres with varying cellulose to
cellulose acetate ratios in the composite filaments dyed with
Colour Index Disperse Violet 1.
[0032] FIG. 6: a graphical representation of the CIE L*a*b* colour
space data for the fibre samples of FIGS. 5a to 5g.
[0033] FIGS. 7a to 7g: samples of fibres with varying cellulose to
cellulose acetate ratios in the composite filaments dyed with
Colour Index Disperse Red 1.
[0034] FIG. 8: a graphical representation of the CIE L*a*b* colour
space data for the fibre samples of FIGS. 7a to 7g.
[0035] FIG. 9: a photograph showing the difference in colour
intensity of in-dope dyed fibres according to the present invention
compared to in-dope dyed cellulose-only fibres.
DESCRIPTON
[0036] In accordance with the present invention there is provided a
coloured fibre comprising one or more composite filaments of
cellulose and cellulose acetate, wherein the colour is effected by
a disperse dye.
[0037] Reference herein to composite filaments of cellulose and
cellulose acetate shall be understood to mean filaments spun from a
dope comprising cellulose and cellulose acetate.
[0038] Composite filaments of cellulose and cellulose acetate spun
from the dope may comprise: a continuous phase of cellulose
containing dispersed phases of cellulose acetate; a continuous
phase of cellulose acetate containing dispersed phases of
cellulose; and/or a co-continuous phase of cellulose and cellulose
acetate, for example.
[0039] The inventors of the present invention have surprisingly
found that fibres comprising one or more composite filaments of
cellulose and cellulose acetate have a good affinity for
hydrophobic disperse dyes. Such fibres can be manufactured without
the need for additional chemical treatments such as the
hydrophobisation of the cellulose component through chemical
derivatisation as in Canadian patent application number 1072260, or
the addition of a coupling component as in U.S. Pat. No.
3,713,767.
[0040] Without wishing to be bound by any such theory, the
inventors of the present invention believe that the hydrophilic
cellulose in the composite filaments swells up when contacted with
the aqueous portion of a disperse dye or with the supercritical
CO.sub.2 used in the disperse dyeing process. It is believed that
when the cellulose swells up in this manner, the disperse dye can
more easily penetrate the hydrophobic part of the fibre i.e. the
cellulose acetate. As a result, the entire fibre can be readily
dyed with the disperse dye.
[0041] The weight ratio of the cellulose to the cellulose acetate
in the composite filaments may be from 99:1 to 1:99, from 95:5 to
5:95, from 90:10 to 10:90, from 80:20 to 20:80, from 70:30 to
30:70, or from 60:40 to 40:60. The weight ratio of the cellulose to
the cellulose acetate in the composite filaments may be from 90:10
to 50:50, from 80:20 to 50:50, from 70:30 to 50:50, or from 60:40
to 50:50.
[0042] Advantageously, the affinity of the fibre for the disperse
dye can be varied by altering the weight ratio of the cellulose to
the cellulose acetate in the composite filaments, thereby making
the fibre more or less hydrophilic. This may be useful for varying
the colour intensity of the fibre, and means the colour intensity
of the fibre can be tailored according to a manufacturer's
requirements. In addition, by reducing the hydrophilicity of the
fibre i.e. by increasing the cellulose acetate content, the fibre
may become less receptive to waterborne stains.
[0043] The disperse dye may be any known suitable disperse dye. For
example, the disperse dye may be selected from: anthraquinone dyes,
for example Colour Index Disperse Red 15, Colour Index Disperse Red
60, Colour Index Disperse Violet 4 and Colour Index Disperse Violet
26; azo dyes, for example Colour Index Disperse Yellow 3, Colour
Index Disperse Orange 25, Colour Index Disperse Red 167, Colour
Index Disperse Violet 33 and Colour Index Disperse Blue 79;
nitroarylamine; coumarin; methine; naphthostyryl; formazan; and
benzodifuranone.
[0044] The coloured fibre may be used as a bleach activator.
[0045] In this context, the term `bleach activator` is used to
describe a material that is capable of reacting with a peroxide
and/or a peroxide precursor, to form peracetic acid.
[0046] Also provided in accordance with the present invention is a
fibre blend comprising fibres comprising one or more composite
filaments of cellulose and cellulose acetate; and synthetic fibres,
wherein the fibre blend is dyeable with a disperse dye.
[0047] Also provided in accordance with the present invention is a
coloured fibre blend comprising fibres comprising one or more
composite filaments of cellulose and cellulose acetate; and
synthetic fibres, wherein the colour is effected by a disperse
dye.
[0048] Advantageously, the fibre blend of the present invention is
capable of being dyed using a disperse dye in a single-stage
process. Thus, the cost and complexity of the dyeing process are
significantly reduced compared to prior art dyeing processes for
fibre blends. As previously outlined, the prior art processes for
dyeing natural/synthetic fibre blends require complex, multi-stage
processes which result in an increase in manufacturing costs.
[0049] The synthetic fibres may be any known suitable synthetic
fibres, for example polyester fibres, nylon fibres, acrylic fibres,
elastane fibres, cellulose acetate fibres, cellulose triacetate
fibres, polylactic acid fibres, polypropylene fibres, or
polyphenylene sulfide fibres.
[0050] The fibre blend may be used as a bleach activator.
[0051] Also provided in accordance with the present invention is a
textile manufactured from the coloured fibres comprising one or
more composite filaments of cellulose and cellulose acetate as
hereinbefore described.
[0052] Also provided in accordance with the present invention is a
textile manufactured from the fibre blend as hereinbefore
described.
[0053] Also provided in accordance with the present invention is a
textile manufactured from the coloured fibre blend as hereinbefore
described.
[0054] Also provided in accordance with the present invention is a
textile manufactured from fibres comprising composite filaments of
cellulose and cellulose acetate, and synthetic and/or natural
fibres, wherein the fibres comprising composite filaments and the
synthetic and/or natural fibres are provided in separate yarn or
thread.
[0055] Advantageously, the textile is capable of being dyed using
disperse dyes in a single-stage process. Thus, the cost and
complexity of the dyeing process are significantly reduced compared
to prior art dyeing processes for textiles having both natural and
synthetic fibres. The prior art processes for dyeing textiles
having both natural and synthetic fibres require complex,
multi-stage processes which result in an increase in manufacturing
costs.
[0056] The textile provided in accordance with the present
invention will have a unique combination of physical, aesthetic and
tactile properties. These properties can be adjusted through the
optimisation of the weight ratio of the cellulose to the cellulose
acetate in the composite filaments and/or by altering the fibre
morphology, for example the denier, cross-sectional shape and
degree of elongation during the spinning of the fibres.
[0057] The denier per filament may be from about 0.1 to about 100
g/9000 m. Preferably, the denier per filament is from about 0.3 to
about 50 g/9000 m or from about 0.5 to about 25 g/9000 m.
[0058] The cross-sectional shape may be selected from flat,
circular, elliptical, triangular, hexagonal, rounded triangular,
trilobal, lobular, mushroom-shaped, dog-bone-shaped, ribbon-shaped,
star-shaped, hollow/tubular and collapsed tube.
[0059] The degree of elongation may be from about 0% to about 100%,
from about 0% to about 75% or from about 0% to 50%.
[0060] The textiles as hereinbefore described may be used as a
bleach activator.
[0061] Also provided in accordance with the present invention is a
garment or soft furnishing made at least partly from the textile as
hereinbefore described.
[0062] Also provided in accordance with the present invention is a
process for manufacturing the coloured fibre as hereinbefore
described, comprising: providing a solution dope comprising a blend
of cellulose and cellulose acetate in an ionic liquid or in
N-methylmorpholine-N-oxide; spinning the solution dope into a
coagulant to generate fibres; and dyeing the fibres with a disperse
dye.
[0063] Also provided in accordance with the present invention is a
process for manufacturing the coloured fibre as hereinbefore
described, comprising: providing a solution dope comprising a blend
of cellulose and cellulose acetate in an ionic liquid or in
N-methylmorpholine-N-oxide; adding a disperse dye to the solution
dope; and spinning the solution dope with the disperse dye into a
coagulant to generate coloured fibres.
[0064] This process does not require a separate dyeing step after
the fibres have been generated. Rather, by adding the disperse dye
to the solution dope i.e. by `in-dope` dyeing, coloured fibres are
directly generated from the spinning step. This is advantageous as
it simplifies the manufacturing process and may reduce
manufacturing costs.
[0065] In addition, the `in-dope` dyeing process may reduce
chemical waste by eliminating the use of dye baths. This may reduce
both the manufacturing costs and the environmental impact of the
process.
[0066] Further advantageously, the ability to dose the disperse dye
into the solution dope enables excess dye uptake by the fibres to
be avoided, which eliminates the presence of fugitive dye. The
resulting coloured fibres may, therefore, exhibit enhanced
colourfastness to light, washing, crocking (rubbing), perspiration,
and bleach.
[0067] The following description applies to both manufacturing
processes outlined above.
[0068] The use of ionic liquids and N-methylmorpholine-N-oxide
(NMMO) for dissolving cellulose and other polymers is known in the
art. A wide range of ionic liquids are suitable for dissolving
cellulose and cellulose acetate to form a solution dope and for
spinning fibres therefrom. Suitable ionic liquids include those
based on imidazole, pyrrole, thiazole, or pyrazole cations in
combination with halogen, phosphite, carboxylate or metal chloride
anions. Particularly preferred ionic liquids of this type include
1-butyl-3-methylimidazolium chloride (BMIM-Cl),
1-butyl-3-methylimidazolium acetate (BMIM-Ac) and
1-ethyl-3-methylimidazolium acetate (EMIM-Ac). Suitable ionic
liquids also include those comprising a conjugate acid formed from
a strong organic base, for example a substituted amidine or
guanidine, in combination with a weaker Bronsted acid, for example
a carboxylic acid. Particularly preferred ionic liquids of this
type include 1,1',3,3'-tetramethylguanidinine carboxylates,
1,8-diazabicyclo[5.4.0]undec-7-ene carboxylates and
1,5-diazabicyclo[4.3.0]non-5-ene carboxylates.
[0069] The solution dope may also comprise a suitable co-solvent,
for example an aprotic solvent. Examples of suitable co-solvents
include dimethyl sulfoxide (DMSO), dimethylformamide (DMF),
tetrahydrofuran (THF), and dioxane. The co-solvent may aid
dissolution of the cellulose and cellulose acetate. A particularly
preferred co-solvent is DMSO.
[0070] Where a co-solvent is used, the ratio of the ionic liquid or
NMMO to the co-solvent may be selected to ensure dissolution of
both the cellulose and cellulose acetate, whilst providing a
solution suitable for spinning into fibres.
[0071] The weight ratio of the cellulose to the cellulose acetate
in the solution dope may be from 99:1 to 1:99, from 95:5 to 5:95,
from 90:10 to 10:90, from 80:20 to 20:80, from 70:30 to 30:70, or
from 60:40 to 40:60. The weight ratio of the cellulose to the
cellulose acetate in the solution dope may be from 90:10 to 50:50,
from 80:20 to 50:50, from 70:30 to 50:50, or from 60:40 to
50:50.
[0072] Typically, the solution dope comprises a solids content of
up to about 50% by weight, up to about 45% by weight, up to about
40% by weight, up to about 35% by weight, up to about 30% by
weight, up to about 25% by weight, or up to about 20% by weight.
Preferably the solution dope comprises a solids content of from
about 5% by weight to about 25% by weight, or from about 10% by
weight to about 20% by weight.
[0073] The solution dope is preferably spun using a spinneret.
[0074] The coagulant may be any suitable non-solvent. Preferably,
the coagulant comprises water, methanol and/or ethanol. Water is a
particularly preferred coagulant.
[0075] The disperse dye may be any known suitable disperse dye. For
example, the disperse dye may be selected from those previously
outlined.
[0076] The process may further include the application of a spin
finish, for example an emulsifier, lubricant and/or antistatic spin
finish. Preferably, an emulsifier, lubricant and antistatic spin
finish are applied.
[0077] The emulsifier may be selected from one or more of: alkali
surfactants; amine surfactants; glycerol mono-di-fatty acid esters;
sorbitan esters; polyoxyethylene sorbitan esters; polyglycerol
esters, polyoxyethylene esters; polyoxyethylene ethers;
polyoxyethylene polyol ether esters; polyoxyethylene amines;
polyoxyethylene amides; partial polyol ester ethoxylates; sulfated
vegetable oils; and sulfonated aromatic petroleum.
[0078] The lubricant may be selected from one or more of: mineral
oils; alkyl esters; glycerides; silicone oils; waxes, for example
paraffinic wax, naphthenic wax or polyolefinic wax; polyalkene
glycols; polyoxalkylene glycols; and glycol esters.
[0079] The antistatic agent may be selected from one or more of:
cationic species, including quaternary ammonium, pyridinium,
imidazolium, or quinolinium species; phosphate alcohols; phosphate
ethoxylates of fatty acids and fatty alcohols; amines; amides;
organic sulfates; and organic sulfonates.
[0080] The process may further include drying of the fibres,
preferably at raised temperatures, for example between 50.degree.
C. and 150.degree. C.
[0081] Also provided in accordance with the present invention is a
process for dyeing fibres comprising one or more composite
filaments of cellulose and cellulose acetate, comprising:
contacting the fibres with a disperse dye; and washing the dyed
fibres with water.
[0082] Also provided in accordance with the present invention is a
process for dyeing the fibre blend as hereinbefore described,
comprising: contacting the fibre blend with a disperse dye; and
washing the dyed fibre blend with water.
[0083] The disperse dye may be applied from an aqueous dispersion
or using supercritical CO.sub.2, for example. Applying the disperse
dye using supercritical CO.sub.2 may have the advantages of
reducing the amount of dye-containing effluent, increasing the rate
of dye uptake and enabling the recycling of dyes and solvents.
[0084] Advantageously, the fibre blend of the present invention can
be dyed using disperse dyes in a single-stage process. The dyeing
time for the fibre blend of the present invention may be
significantly reduced compared to prior art dyeing processes.
EXAMPLE 1
Preparation of Fibres
[0085] Using standard wet-spinning equipment, fibres were spun from
a solution of 8 wt. % cellulose (DP .about.450) and 8 wt. %
cellulose acetate (Eastman, CA-398-30), at 16% solids in
EMIM-Ac:DMSO (26:74). A cluster head containing 7.times.560-orifice
spinnerets with an orifice diameter of 40 .mu.m was used. The
spinnerets were submerged in a water coagulation bath heated to a
temperature of 80.degree. C. The fibres were washed extensively
with water, dried at 120.degree. C. and reeled up.
[0086] FIG. 1 is a photograph of the resulting fibres once reeled
up.
[0087] FIG. 2 is a scanning electron microscopy (SEM) image of a
resulting fibre.
EXAMPLE 2
Dyeing of Fibres
Violet
[0088] 2 wt. % of Colour Index Disperse Violet 1
(1,4-Diaminoanthraquinone, Aldrich) in water was used as the
disperse dye liquor. A sample of fibres prepared according to
Example 1 was dyed using a disperse dye liquor to fibre ratio of
10:1 (wt./wt.), with a liquor of pH 5. The temperature of the
disperse dye liquor was raised to 98.degree. C. for 45 minutes. The
sample was washed thoroughly with water until the washings were
colourless.
[0089] As a comparative example, a sample of cotton fabric was dyed
using a disperse dye liquor to fibre ratio of 10:1 (wt./wt.), with
a liquor of pH 5. The temperature of the disperse dye liquor was
raised to 98.degree. C. for 45 minutes. The sample was washed
thoroughly with water until the washings were colourless.
[0090] FIG. 3a shows the sample of cotton fabric dyed with Colour
Index Disperse Violet 1 (comparative).
[0091] FIG. 3b shows a sample of the fibres in accordance with the
present invention dyed with Colour Index Disperse Violet 1.
[0092] From these figures it can be seen that the sample of fibres
in accordance with the present invention exhibits a much deeper,
more intense violet colour and the dye is more evenly dispersed
through the sample, compared to the pure cotton fabric sample.
Red
[0093] 2 wt. % of Colour Index Disperse Red 279 (Terasil Red GS LA
supplied by Ciba) in water was used as the disperse dye liquor. A
sample of fibres prepared according to Example 1 was dyed using a
disperse dye liquor to fibre ratio of 10:1 (wt./wt.), with a liquor
of pH 5. The temperature of the disperse dye liquor was raised to
98.degree. C. for 45 minutes. The sample was washed thoroughly with
water until the washings were colourless.
[0094] As a comparative example, a sample of cotton fabric was dyed
using a disperse dye liquor to fibre ratio of 10:1 (wt./wt.), with
a liquor of pH 5. The temperature of the disperse dye liquor was
raised to 98.degree. C. for 45 minutes. The sample was washed
thoroughly with water until the washings were colourless.
[0095] FIG. 4a shows the sample of cotton fabric dyed with Colour
Index Disperse Red 279 (comparative).
[0096] FIG. 4b shows a sample of the fibres in accordance with the
present invention dyed with Colour Index Disperse Red 279.
[0097] From these figures it can be seen that the sample of fibres
in accordance with the present invention exhibits a much deeper,
more intense red colour and the dye is more evenly dispersed
through the sample, compared to the pure cotton sample.
EXAMPLE 3
Preparation of Fibres
[0098] Using standard wet-spinning equipment, fibres were spun from
solutions of cellulose (DP .about.450) and cellulose acetate
(Eastman, CA-398-30), at ratios of 100:0 (comparative), 0:100
(comparative), 90:10, 80:20, 70:30, 60:40 and 50:50, at 16% solids
in EMIM-Ac:DMSO (50:50). A cluster head containing
7.times.560-orifice spinnerets with an orifice diameter of 40 .mu.m
was used. The spinnerets were submerged in a water coagulation bath
heated to a temperature of 80.degree. C. The fibres were washed
extensively with water, dried at 120.degree. C. and reeled up.
EXAMPLE 4
Dyeing of Fibres
Violet
[0099] 2 wt. % of Colour Index Disperse Violet 1
(1,4-Diaminoanthraquinone, Aldrich) in water was used as the
disperse dye liquor. Fibre samples prepared according to Example 3
were dyed using a disperse dye liquor to fibre ratio of 10:1
(wt./wt.), with a liquor of pH 5. The temperature of the disperse
dye liquor was raised to 98.degree. C. for 45 minutes. The samples
were washed thoroughly with water until the washings were
colourless. The samples were dried at 50.degree. C. overnight.
[0100] FIGS. 5a to 5g show the samples dyed with Colour Index
Disperse Violet 1, as follows:
TABLE-US-00001 FIG. Cellulose to Cellulose Acetate Ratio FIG. 5a
100:0 (comparative) FIG. 5b 0:100 (comparative) FIG. 5c 90:10 FIG.
5d 80:20 FIG. 5e 70:30 FIG. 5f 60:40 FIG. 5g 50:50
[0101] The CIE L*a*b* colour space data for each of the dyed
samples was determined using a Gretag Macbeth Colour-Eye 7000A
Spectrophotometer in reflectance mode with D65 illumination. The
CIE L*a*b* colour space data for the dyed samples is shown in Table
1, where:
TABLE-US-00002 TABLE 1 % Cellulose % Cellulose Acetate L* a* b* 100
0 82.16 7.48 -1.28 90 10 63.56 20.84 -13.4 80 20 57.81 23.77 -14.06
70 30 57.87 23.12 -16.47 60 40 46.45 31.61 -25.73 50 50 45.58 25.56
-28.54 0 100 31.2 45.22 -31.18 L* represents Lightness, where 0 is
absolute black and 100 is absolute white a* represents the green to
red axis, where -128 is green and +128 is red b* represents the
blue to yellow axis, wherein -128 is blue and +128 is yellow
[0102] FIG. 6 is a graphical representation of the CIE L*a*b*
colour space data.
[0103] From the data and figures it can be seen that the samples of
fibres in accordance with the present invention exhibit good violet
colouring following dyeing with the disperse dye, particularly when
compared to the 100% cellulose sample.
[0104] As the proportion of cellulose acetate was increased in the
fibre samples the lightness of the samples was reduced i.e. the
intensity of the violet colour increased. An intense violet colour
which was a close colour match to the 100% cellulose acetate sample
was exhibited by the fibre sample with a cellulose to cellulose
acetate ratio of 50:50.
[0105] As the proportion of cellulose acetate was increased in the
fibre samples both the red and the blue components increased,
approaching those of the 100% cellulose acetate sample at around
50% cellulose acetate content.
Red
[0106] 2 wt. % of Colour Index Disperse Red 1
(N-Ethyl-N-(2-hydroxyethyl)-4-(4-nitrophenylazo) aniline, Aldrich)
in water was used as the disperse dye liquor. Fibre samples
prepared according to Example 3 were dyed using a disperse dye
liquor to fibre ratio of 10:1 (wt./wt.), with a liquor of pH 5. The
temperature of the disperse dye liquor was raised to 98.degree. C.
for 45 minutes. The samples were washed thoroughly with water until
the washings were colourless. The samples were dried at 50.degree.
C. overnight.
[0107] FIGS. 7a to 7g show the samples dyed with Colour Index
Disperse Red 1, as follows:
TABLE-US-00003 FIG. Cellulose to Cellulose Acetate Ratio FIG. 7a
100:0 (comparative) FIG. 7b 0:100 (comparative) FIG. 7c 90:10 FIG.
7d 80:20 FIG. 7e 70:30 FIG. 7f 60:40 FIG. 7g 50:50
[0108] The CIE L*a*b* colour space data for each of the dyed
samples was determined using a Gretag Macbeth Colour-Eye 7000A
Spectrophotometer in reflectance mode with D65 illumination. The
CIE L*a*b* colour space data for the dyed samples is shown in Table
2, where:
TABLE-US-00004 TABLE 2 % Cellulose % Cellulose Acetate L* a* b* 100
0 76.74 21.09 2.77 90 10 60.60 37.21 18.39 80 20 51.25 44.97 27.42
70 30 45.55 43.99 23.84 60 40 44.68 43.18 21.54 50 50 39.48 47.44
27.65 0 100 40.55 50.01 35.11 L* represents Lightness, where 0 is
absolute black and 100 is absolute white a* represents the green to
red axis, where -128 is green and +128 is red b* represents the
blue to yellow axis, wherein -128 is blue and +128 is yellow
[0109] FIG. 8 is a graphical representation of the CIE L*a*b*
colour space data.
[0110] From the data and figures it can be seen that the samples of
fibres in accordance with the present invention exhibit good red
colouring following dyeing with the disperse dye, particularly when
compared to the 100% cellulose sample.
[0111] As the proportion of cellulose acetate was increased in the
fibre samples the lightness of the samples was reduced i.e. the
intensity of the red colour increased. An intense red colour which
was a close colour match to the 100% cellulose acetate sample was
exhibited by the fibre samples with a cellulose to cellulose
acetate ratio of 70:30, 60:40 and 50:50.
[0112] As the proportion of cellulose acetate was increased in the
fibre samples both the red and yellow components increased,
approaching those of the 100% cellulose acetate sample at around
50% cellulose acetate content.
EXAMPLE 5
In-Dope Dyeing of Fibres
[0113] A solution dope according to the invention was prepared by
combining 8 wt. % cellulose (DP .about.450) and 8 wt. % cellulose
acetate (Eastman, CA-398-30), at 16% solids in EMIM-Ac:DMSO
(26:74).
[0114] 0.25 wt. % (by weight of cellulose/cellulose acetate) of
Colour Index Disperse Red 1
(N-Ethyl-N-(2-hydroxyethyl)-4-(4-nitrophenylazo) aniline, Aldrich)
was added to the solution dope and stirred for 1 minute to ensure
even distribution of the disperse dye.
[0115] The solution dope (including the disperse dye) was injected
into a water bath using a syringe submerged into a coagulation
bath, whereby the coagulant was water with a temperature of
18.degree. C. Upon coagulation, the solution dope formed coloured
fibres. The coloured fibres were washed thoroughly with clean
water, and then air dried at ambient temperature.
[0116] As a comparative example, a solution dope was prepared with
8 wt. % cellulose (DP .about.450) in EMIM-Ac:DMSO (26:74). The
remaining process steps were carried out as above.
[0117] It was observed that for the in-dope dyed fibres according
to the present invention, there was no bleeding of the disperse dye
from the fibres into the coagulation bath or during subsequent
washings.
[0118] In contrast, for the in-dope dyed fibres of the comparative
example (cellulose-only fibres), extensive bleeding of the disperse
dye from the fibres into the coagulation bath and during subsequent
washings, was observed.
[0119] As a result, the colour intensity of the fibres according to
the present invention was significantly better than the colour
intensity of the cellulose-only fibres.
[0120] FIG. 9 shows the difference in colour intensity of the
in-dope dyed fibres according to the present invention (right-hand
side) compared to the in-dope dyed cellulose-only fibres (left-hand
side).
* * * * *