U.S. patent application number 09/826223 was filed with the patent office on 2002-04-04 for method of preparing water-soluble non-woven fabric.
Invention is credited to Shin, Jae Kyun.
Application Number | 20020039868 09/826223 |
Document ID | / |
Family ID | 19691171 |
Filed Date | 2002-04-04 |
United States Patent
Application |
20020039868 |
Kind Code |
A1 |
Shin, Jae Kyun |
April 4, 2002 |
Method of preparing water-soluble non-woven fabric
Abstract
The water-soluble non-woven fabric according to the present
invention is prepared by (a) preparing a non-woven fabric with
cellulose fibers, (b) mercerizing the non-woven fabric with aqueous
sodium hydroxide in a solvent in a bath, (c) carrying out
etherification of the mercerized fabric by adding monochloro acetic
acid solution, (d) neutralizing the fabric with a hydrochloric acid
solution to be a pH of about 6.0 to 9.0 in the bath, and (e)
post-treating the fabric through dehydration and drying. The
dissolving time of the non-woven fabric can be controlled depending
on the amounts of the solid monochloro acetic acid, solid sodium
hydroxide and hydrochloric acid to be used.
Inventors: |
Shin, Jae Kyun;
(Kyeongki-do, KR) |
Correspondence
Address: |
Woodcock Washburn Kurtz
Mackiewicz & Norris LLP
One Liberty Place - 46th Floor
Philadelphia
PA
19103
US
|
Family ID: |
19691171 |
Appl. No.: |
09/826223 |
Filed: |
April 4, 2001 |
Current U.S.
Class: |
442/414 ;
442/327 |
Current CPC
Class: |
D04H 1/04 20130101; Y10T
442/696 20150401; D21H 25/02 20130101; D06M 2101/06 20130101; D06M
11/11 20130101; D04H 1/425 20130101; Y10T 442/60 20150401; D06M
13/21 20130101; D04H 1/4258 20130101; D06M 11/40 20130101 |
Class at
Publication: |
442/414 ;
442/327 |
International
Class: |
D04H 001/00; D04H
003/00; D04H 005/00; D04H 013/00 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 29, 2000 |
KR |
2000-57474 |
Claims
What is claimed is:
1. A method of preparing a water-soluble non-woven fabric,
comprising the steps of: (a) preparing a non-woven fabric being
made of cellulose fibers; (b) mercerizing the non-woven fabric with
aqueous sodium hydroxide in a solvent in a bath; (c) carrying out
etherification of the mercerized fabric by adding monochloro acetic
acid solution; (d) neutralizing the fabric with a hydrochloric acid
solution to be a pH of about 6.0 to 9.0 in the bath; and (e)
post-treating the fabric through dehydration and drying.
2. The method as defined in claim 1, wherein said non-woven fabric
is a woven fabric, a knitted fabric, a sheet or a film being made
of cellulose fibers.
3. The method as defined in claim 1, wherein said solvent is an
alcohol or an ester.
4. The method as defined in claim 1, wherein said alcohol is
selected from the group consisting of methyl alcohol, ethyl alcohol
and isopropyl alcohol.
5. The method as defined in claim 1, wherein said mercerization
(step (b)) is conducted in aqueous sodium hydroxide prepared by
dissolving about 50-80 g of solid sodium hydroxide in powder per
100 g of the non-woven fabric in about 30-180 g of water and in a
solvent of about 600-1000 ml per 100 g of the non-woven fabric at
the temperature of about 30-60.degree. C. for about 1-4 hours.
6. The method as defined in claim 1, wherein said etherification
(step (c)) is conducted by adding monochloro acetic acid solution
prepared by dissolving about 10-120 g of monochloro acetic acid in
solid per 100 g of the non-woven fabric in about 20-720 g of a
solvent at the temperature of about 60-90.degree. C. for about 1-3
hours.
7. The method as defined in claim 1, wherein said neutralization
(step (d)) is conducted by adding hydrochloric acid solution
prepared by mixing about 10-40 ml of hydrochloric acid with about
300 - 500 ml of a solvent per 100 g of the non-woven fabric to be
the pH in the range of about 6.0-9.0.
8. The method as defined in claim 1, wherein said neutralization
(step (d)) is conducted in a separate reactor filled with
hydrochloric acid solution prepared by mixing about 10-40 ml of
hydrochloric acid with about 300-500 ml of a solvent per 100 g of
the non-woven fabric to be the pH in the range of about
6.0-9.0.
9. The method as defined in claim 1, wherein said drying in step
(e) is conducted in a dryer in the range of about 50-150.degree.
C.
10. The method as defined in claim 6, wherein said monochloro
acetic acid in solid is used in the amount of about 10-40 g of per
100 g of the non-woven fabric.
11. The method as defined in claim 6, wherein said monochloro
acetic acid in solid is used in the amount of about 40-80 g of per
100 g of the non-woven fabric.
12. The method as defined in claim 6, wherein said monochloro
acetic acid in solid is used in the amount of about 80-120 g of per
100 g of the non-woven fabric.
13. A water-soluble non-woven fabric which is prepared in
accordance with the method of claim 1.
14. A water-soluble non-woven fabric which is prepared in
accordance with the method of claim 10 and has a dissolving time of
at least 1 month.
15. A water-soluble non-woven fabric which is prepared in
accordance with the method of claim 11 and has a dissolving time
between at least 2 hours and at most 1 month.
16. A water-soluble non-woven fabric which is prepared in
accordance with the method of claim 12 and has a dissolving time of
at most 2 hours.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to a method of preparing a
water-soluble non-woven fabric or cloth. More particularly, the
present invention relates to a method of preparing a water-soluble
non-woven fabric or cloth that is prepared from cellulose fibers.
The present invention includes a non-woven fabric or cloth, sheet,
film, woven fabric, knitted fabric, yam and the like, which are
water-soluble by preparing in accordance with the method of the
present invention.
BACKGROUND OF THE INVENTION
[0002] Non-woven fabric is widely used in various applications, for
example, baby's napkin, women's sanitary napkin and toilet paper,
packaging materials of foods and detergents, adsorbents, adhesives,
base fabric for embroidery, head rest for airplane seat and the
like. The conventional various non-woven fabric is made of
synthetic fibers or natural fibers. As the synthetic fibers are not
water-soluble, the non-woven fabric causes a serious environmental
problem. Although the non-woven fabric is made of natural fibers,
if the natural fibers are not water-soluble, the non-woven fabric
causes an environmental problem, too.
[0003] The natural fibers are cellulose fibers and are classified
into pure natural fibers such as cotton and wool, regenerated
fibers such as viscose rayon, and pulp fibers. The synthetic fibers
are prepared from polymers such as polyethylene, polypropylene,
polyamide, polyester and the like. Such natural and synthetic
fibers are not water-soluble. Therefore, most of the conventional
non-woven fabrics including the packaging material and the head
rest are water insoluble.
[0004] Such non-woven fabrics are rarely recycled and disposed by
burial in the ground or by combustion. The burial or combustion of
the non-woven fabric causes serious environmental problems. If the
non-woven fabric is water-soluble, however, such environmental
problems could be prevented.
[0005] When a water-soluble non-woven fabric is absolutely needed,
a special method to dissolve the non-woven fabric has been applied.
For example, a base fabric for embroidery should be water-soluble.
The base fabric for embroidery is typically a non-woven fabric and
is used for embroidery in lingerie. Once the base fabric is used to
embroider on the lingerie, the base fabric should be removed by
dissolving. The conventional non-woven base fabric for embroidery
is prepared from polyvinyl alcohol staple fibers. To remove the
base fabric after embroidery, the product should be treated in a
hot bath over 95.degree. C. As the product is treated in a hot bath
to remove the base fabric, the lingerie can be damaged, the cost
for manufacturing increases, and the material of the lingerie
should be resistant to the hot temperature.
[0006] If a base fabric for embroidery which is water-soluble at
room temperature is developed, the disadvantages described above
can be solved. If so, it is not necessary to treat the lingerie at
a hot bath to remove the base fabric, the cost for manufacturing
shall go down, the material of the lingerie can be diversified to
choose, and there is no risk for the product to be damaged from the
hot bath.
[0007] If a non-woven fabric which is water-soluble at room
temperature is developed, the applications can be expanded, for
example, to the packaging materials, mulch films for agriculture,
gauze for medical use and the like. The conventional gauze is
agglomerated with blood on the skin of a human body. Accordingly,
when the gauze is removed, a pain occurs. If the gauze is
water-soluble at room temperature or hot water-soluble, the gauze
can be easily removed without pain by dissolving the gauze in the
water.
[0008] Further, if a water-soluble non-woven fabric is developed,
the non-woven fabric can be applied to mulch film for agriculture.
There has been a lot of effort to develop a water-soluble,
biodegradable or ultraviolet degradable mulch film to obviate
environmental problems. However, conventional mulch films are
collected to dispose after harvest. Although a water-soluble
non-woven fabric is developed, the non-woven fabric should not be
dissolved for a certain period. Usually the non-woven fabric for
mulch film should not be dissolved for about three months which is
a cultivation period. In other words, if a non-woven fabric should
have a dissolving time for about three months, the fabric can be
applied to a mulch film.
[0009] U.S. Pat. No. 5,041,252 teaches a non-woven fabric
consisting of water-soluble resin fine fibers having a mean fiber
diameter of at most 30 .mu.m and a basis weight of 5 to 500
g/m.sup.2, which is prepared by extruding an aqueous solution
containing a water-soluble resin or a melt of a water-soluble resin
plasticized with water through nozzles, stretching the extruded
material to form fibers by a high speed gas flow, heating the
fibers to evaporate the water in the fibers and then collecting the
fibers.
[0010] Korean Patent Laid-Open No. 1999-67946 discloses a water
degradable non-woven fabric which is treated with a water jet, and
has a high density portion and a low density portion, and has a
breaking strength of at most 100 g/25 mm at wet state, and contains
a water-soluble or water swelling binder. The present invention,
however, is distinct from the inventions of the U.S. patent and the
Korean patent application above.
[0011] The present inventor has developed a new method of preparing
a non-woven fabric which is water-soluble at room temperature, and
whose dissolving time can be controlled for use.
OBJECTS OF THE INVENTION
[0012] A feature of the present invention is the provision of a
non-woven fabric which is water-soluble at room temperature.
[0013] Another feature of the present invention is the provision of
a water-soluble non-woven fabric which does not cause environmental
pollution.
[0014] A further feature of the present invention is the provision
of a water-soluble non-woven fabric which is used as a base fabric
for embroidery for lingerie, thereby the product is not treated in
a hot bath, the lingerie cannot be damaged, the cost for
manufacturing decreases, and more materials for lingerie are
available.
[0015] A further feature of the present invention is the provision
of a water-soluble non-woven fabric which is used as mulch film for
agriculture.
[0016] A further feature of the present invention is the provision
of a water-soluble non-woven fabric which is used as a head rest
for airplanes or buses.
[0017] A further feature of the present invention is the provision
of a water-soluble non-woven fabric whose dissolving time can be
controlled for use.
[0018] A feature of the present invention is the provision of a
method of preparing a non-woven fabric which is water-soluble at
room temperature.
[0019] Other objects and advantages of this invention will be
apparent from the ensuing disclosure and appended claims.
SUMMARY OF THE INVENTION
[0020] The water-soluble non-woven fabric according to the present
invention is prepared by (a) preparing a non-woven fabric with
cellulose fibers, (b) mercerizing the non-woven fabric with aqueous
sodium hydroxide in a solvent in a bath, (c) carrying out
etherification of the mercerized fabric by adding monochloro acetic
acid solution, (d) neutralizing the fabric with a hydrochloric acid
solution to be a pH of about 6.0 to 9.0 in the bath, and (e)
post-treating the fabric through dehydration and drying. The
dissolving time of the non-woven fabric can be controlled depending
on the amounts of the solid monochloro acetic acid, solid sodium
hydroxide and hydrochloric acid to be used.
DETAILED DESCRIPTION OF THE INVENTION
[0021] To prepare a water-soluble non-woven fabric according to the
present invention, a non-woven fabric should be prepared with
cellulose fibers. The non-woven fabric is treated to provide water
solubility in accordance with the method of the present invention.
A non-woven fabric prepared with synthetic fibers cannot be applied
to the method of the present invention. A woven fabric, a knitted
fabric, a sheet and a film which are prepared with cellulose fibers
can be applied to a method of the present invention. Therefore, in
the present invention, the non-woven fabric prepared with cellulose
fibers includes a woven fabric, a knitted fabric, a sheet and a
film which are prepared with cellulose fibers.
[0022] The cellulose fibers are classified into pure natural fibers
such as cotton, wool, linen, hemp and the like, regenerated fibers
such as viscose rayon, and pulp fibers. The products prepared with
the cellulose fibers can be water-soluble at room temperature when
they are treated in accordance with the method of the present
invention.
[0023] The non-woven fabric prepared with cellulose fibers is
treated with aqueous sodium hydroxide in a solvent in a bath. The
treatment of a cellulose fibers product with aqueous sodium
hydroxide is known as mercerization. The mercerization is easily
carried out by an ordinary skilled person in the art to which the
present invention pertains. A solvent is used for mercerization.
Alcohols and acetones can be used as the solvent. The
representative examples of alcohols are methyl alcohol, ethyl
alcohol, isopropyl alcohol and the like, and the acetones can be
easily selected by an ordinary skilled person in the art.
[0024] For mercerization in the present invention, aqueous sodium
hydroxide and solvent are put into a closed reactor. Into the
reactor is a non-woven fabric prepared with cellulose fibers. The
aqueous sodium hydroxide is prepared by dissolving about 50-80 g of
solid sodium hydroxide in powder per 100 g of the non-woven fabric
in about 30-180 g of water. A solvent is added to the reactor in
the amount of about 600-1000 ml per 100 g of the non-woven fabric.
The amount of sodium hydroxide controls the dissolving time of the
water-soluble non-woven fabric. In other words, the dissolving time
of the water-soluble non-woven fabric depends on the amount of the
sodium hydroxide to be used in the mercerization step (b). The more
the solid sodium hydroxide is used, the shorter the dissolving time
is. The closed reactor is kept at the temperature of about
30-60.degree. C. The mercerization is conducted for about 1-4
hours.
[0025] After completion of mercerization of the non-woven fabric,
etherification of the mercerized non-woven fabric is carried out by
adding monochloro acetic acid solution to the closed reactor. The
monochloro acetic acid solution is prepared by dissolving about
10-120 g of monochloro acetic acid in solid per 100 g of the
non-woven fabric in about 20-720 g of a solvent. Alcohols and
acetones can be used as the solvent. The closed reactor is kept at
the temperature of about 60-90.degree. C. The etherification is
conducted for about 1-3 hours. The amount of monochloro acetic acid
in solid controls the dissolving time of the water-soluble
non-woven fabric. In other words, the dissolving time of the
water-soluble non-woven fabric depends on the amount of the
monochloro acetic acid in solid to be used in the etherification
step (c). The more the monochloro acetic acid is used, the shorter
the dissolving time is. For example, if about 80-120 g of
monochloro acetic acid in solid per 100 g of the non-woven fabric
is used, the dissolving time is controlled within about 2 hours. If
about 10-40 g of monochloro acetic acid in solid per 100 g of the
non-woven fabric is used, the dissolving time can be extended up to
about 1 through 3 months. In case that a shorter dissolving time is
required as in the base fabric for embroidery, gauze and the like,
the etherification of the non-woven fabric is conducted with a
monochloro acetic acid solution containing a more amount of
monochloro acetic acid. And, in case that a longer dissolving time
is required as in a mulch film for agriculture and the like, the
etherification of the non-woven fabric is conducted with a
monochloro acetic acid solution containing a smaller amount of
monochloro acetic acid.
[0026] After completion of etherification of the non-woven fabric,
the non-woven fabric is neutralized with a hydrochloric acid
solution. The neutralization of the non-woven fabric is conducted
in the closed bath by adding a hydrochloric acid solution. The
neutralization of the non-woven fabric may also be conducted in a
separate bath in which the etherified non-woven fabric is
neutralized with a mixed solution of hydrochlroride and a solvent.
The amount of hydrochloric acid controls the dissolving time of the
water-soluble non-woven fabric. In other words, the dissolving time
of the water-soluble non-woven fabric depends on the amount of the
hydrochloric acid to be used in the neutralization step (d). The
bath for neutralization should be kept at a pH of about 6.0-9.0.
The hydrochloric acid solution is prepared by mixing about 10-40 ml
of hydrochloric acid with about 300-500 ml of a solvent per 100 g
of the non-woven fabric.
[0027] After completion of neutralization of the non-woven fabric,
the non-woven fabric is post-treated through dehydration and
drying. In the post-treating step, the non-woven fabric is
dehydrated by a conventional method which is easily carried out by
an ordinary skilled person in the art. The dehydrated non-woven
fabric is preferably dried at the temperature of about
50-150.degree. C.
[0028] As the non-woven fabric according to the present invention
is prepared with cellulose fibers and is completely water-soluble,
the non-woven fabric can prevent any environmental problem. In
particular, as the dissolving time of the non-woven fabric can be
controlled, the non-woven fabric according to the present invention
has various applications upon the uses.
[0029] The invention may be better understood by reference to the
following examples which are intended for the purpose of
illustration and are not to be construed as in any way limiting the
scope of the present invention, which is defined in the claims
appended hereto. In the following examples, all parts and
percentage are by weight unless otherwise indicated.
EXAMPLES 1A-1D
[0030] Non-woven fabric was prepared with cotton fibers. Four
specimens of the non-woven fabric were prepared. Each specimen
weighed 100 g. The specimens were put into four reactors separately
(Examples 1A-1D). To the reactors were added 50, 60, 70 and 80 g of
solid sodium hydroxide in powder, respectively. Next, 75, 90, 105
and 120 g of water added were added to each of the reactors,
respectively. Methyl alcohol of 800 ml was used in each reactor as
the solvent. The reactors were kept at 50.degree. C. Mercerization
was conducted in the reactors for three hours.
[0031] To each of the closed reactors of Examples 1A-1D were added
100 g of solid monochloro acetic acid and 300 ml of methyl alcohol,
respectively. Etherification was conducted in the reactors at
80.degree. C. for 2 hours.
[0032] To each of the closed reactors was a mixed solution of 30 ml
of hydrochloric acid and 400 ml of methyl alcohol added for
neutralization. The treated non-woven fabrics were dehydrated and
dried at 100.degree. C.
[0033] The water-soluble non-woven fabrics of Examples 1A-1D were
obtained. The dissolving times of the non-woven fabrics of Examples
1A-1D were measured as 1.5, 1.2, 0.5 and 0.2 hour,
respectively.
EXAMPLES 2A-2D
[0034] Non-woven fabric was prepared with cotton fibers. Four
specimens of the non-woven fabric were prepared. Each specimen
weighed 100 g. The specimens were put into four reactors separately
(Examples 2A-2D). To the reactors was added 70 g of solid sodium
hydroxide in powder, respectively. Next, 105 g of water was added
to each of the reactors. Ethyl alcohol of 800 ml was used for each
reactor as the solvent. The reactors were kept at 50.degree. C.
Mercerization was conducted in the reactors for three hours.
[0035] To the closed reactors of Examples 2A-2D, 10, 50, 90 and 120
g of solid monochloro acetic acid were added, respectively. To each
of the reactors 300 ml of ethyl alcohol was added. Etherification
was conducted in the reactors at 80.degree. C. for 2 hours.
[0036] To the closed reactors a mixed solution of 30 ml of
hydrochloric acid and 400 ml of ethyl alcohol was added for
neutralization. The treated non-woven fabrics were dehydrated and
dried at 100.degree. C.
[0037] The water-soluble non-woven fabrics of Examples 2A-2D were
obtained. The dissolving times of the non-woven fabrics of Examples
2A-2D were measured as over 1 month, 3 days, 5 hours and 5 minutes,
respectively.
EXAMPLES 3A-3D
[0038] Non-woven fabric was prepared with cotton fibers. Four
specimens of the non-woven fabric were prepared. Each specimen
weighed 100 g. The specimens were put into four reactors separately
(Examples 3A-3D). To each of the reactors, 70 g of solid sodium
hydroxide powder was added. Next, 105 g of water was added to each
of the reactors. Methyl ketone of 800 ml was used in each reactor
as the solvent. The reactors were kept at 50.degree. C.
Mercerization was conducted in the reactors for three hours.
[0039] To the closed reactors of Examples 3A-3D, 00 g of solid
monochloro acetic acid was added, followed by 300 ml of methyl
ketone. Etherification was conducted in the reactors at 80.degree.
C. for 2 hours.
[0040] To the closed reactors was a mixed solution of 10, 20, 30
and 40 ml of hydrochloric acid and 400 ml of methyl ketone added
for neutralization, respectively. The treated non-woven fabrics
were dehydrated and dried at 100.degree. C.
[0041] The water-soluble non-woven fabrics of Examples 3A-3D were
obtained. The dissolving times of the non-woven fabrics of Examples
3A-3D were measured as 1.3 hour, 0.5 hour, 5 minutes and 1 minute,
respectively.
[0042] The present invention can be easily carried out by an
ordinary skilled person in the art. Many modifications and changes
may be deemed to be with the scope of the present invention as
defined in the following claims.
* * * * *