FORM 2
THE PATENTS ACT, 1970
5 (39 of 1970)
&
THE PATENT RULES, 2003
10
COMPLETE SPECIFICATION
(See Section 10 and Rule 13)
15
Title of Invention:
LIQUID POLYMER SOLUTION FOR TREATING NONWOVEN WEBS
20
Applicant:
POLYGREEN LTD.
a company incorporated in Israel
25 having address:
North Industrial Zone., P.O Box 275,
22102 Nahariya, Israel
30
The following specification particularly describes the invention and the manner in which it is
to be performed.
2
FIELD OF THE INVENTION
The present invention relates to a process for production of water-absorbing textile
material such as non-woven, woven or other textile materials types and related absorbing
products.
5 BACKGROUND OF THE INVENTION
In art there are known processes to manufacture an absorbent textile material, which
can be divided in two distinct classes: a) processes with textile fibers and polymeric
absorbents, b) processes with prefabricated textile materials and reactive liquid media.
10 Forwards are discussed only the processes with prefabricated textile materials and
reactive liquid media.
b) Processes with prefabricated textile materials and reactive liquid media
Particularity of these processes consists in that, a traditional prefabricated textile
15 material like nonwoven, woven, knitted or braided type, is impregnated with a fluid mass in
solution, emulsion or suspension form, and a polymeric absorbent is generated in situ during
the drying of the impregnated wet textile material, or after drying and applying of an
adequate thermal treatment. Representative processes that are known in the art: b1) processes
with polymerizable impregnation mass and b2) processes with cross-linkable impregnation
20 mass.
b1) Processes with polymerizable impregnation mass
In these processes, a liquid used for impregnation produces in-situ polymerization of
partially neutralized acid vinyl monomers directly on a synthetic nonwoven substrate.
25 These processes can be found in U.S. Patents 4,537,590; 4,540,454; 4,573,988; 4,676,784;
5,567,478; 5,962,068; 6,417,425 and 6,645,407.
b2) Processes with cross-linkable impregnation mass
In these processes, the textile material prefabricated as: nonwoven, woven or other
known type is impregnated with a fluid mass in the form of solution or emulsion, that
30 contains polymers in dissolution or dispersion state, or in mixture with auxiliary materials
which are cross-linking agents active at temperatures and induce generation in situ of a
polymeric absorbent. In this class can be seen more variants:
i) Processes with impregnation mass that contain a self–crosslinking synthetic polymer.
3
Various processes are described in which a substantially linear acrylic polymer is cross
linked through its pendant groups. The pendant groups will react with each other upon
appropriate heating. Any combination of monomers that will undergo such reaction can be
used as in U.S. Patents 4,057,521; 4,861,539; 4,962,172 ; 4,963,638 ; 5,280,079 and
5 5,413,747.
The impregnation mass based on self-crosslinking polymers has the disadvantage that
the cross-linking is not complete and because of this reason more than 10 % of end product
is lost during processes associated with extraction of monomers, initiators and organic
solvents residue used during polymerization. Moreover, the free absorbency of the resulting
10 cross linked polymers has a low value (less than 50 g/g in 0.9 % NaCl solution) , and the
product is not safe.
ii) Processes with impregnation mass that contain synthetic polymers and cross-linking
agents
It is further known from U.S. Patent 2,988,539; 3,393,168 and 3,514,419 that water
15 swellable cross-linked carboxylic copolymers can be prepared. However, these prior art
copolymers are all cross-linked during copolymerization or cross-linked after
polymerization with subsequent neutralization of the carboxylic acid groups to form water
swellable polyelectrolytes and hence these prior art polyelectrolytes cannot be cross-linked
in situ as a coating on a substrate or as a flexible film thereof.
20 U.S. Patent 3,926,891; 3,980,663 and 4,155,957 present chemical structures of the
principal classes of combinations that can be used as cross-linking agents for polymers with
free carboxylic chemical functions. Also is shown that cross-linking reaction occurs based
on mechanism known as nucleophilic displacement on saturated carbon. The carboxylate
ion on polymer acts as nucleophile while cross-linking agent is the substrate for nucleophilic
25 attack.
Cheng et al. in U.S. Patent 5,693,707 presents an aqueous polymer composition
comprising 10 to 40 wt % of a polymer in water, the polymer consisting essentially of 20-90
wt % alpha,beta.-ethylenically unsaturated carboxylic acid monomer, 10-80 wt % one or
more softening monomers, the aqueous composition being adjusted to pH 4-6 with alkali
30 metal hydroxide or alkaline earth metal hydroxide and further containing 0.1 to 3 wt %
zirconium crosslinking salt. Such aqueous compositions are applied to nonwoven and
woven substrates to make absorbent textile web.
4
Goldstein et al. in U.S. Patent 6,506,696 shows that the method of forming the high
performance nonwoven webs of this invention comprises: applying an aqueous polymeric
emulsion containing a polymer having dual cross-linkable functionality to a synthetic based
nonwoven web, wherein the dual cross-linkable polymer incorporates acetoacetate
5 functionality and carboxylic acid functionality; removing water and cross-linking the crosslinkable polymer with an effective amount of a polyaldehyde and an effective amount of a
polyaziridine compound.
Soerens Dave Allen in U.S. Patent 7,205,259 presents an absorbent binder desiccant
composition which is capable of spontaneous cross-linking after application to a substrate, at
a temperature of about 120o
10 C or less. The absorbent binder desiccant composition includes a
monoethylenically unsaturated polymer, such as carboxylic acid, sulphonic acid, or
phosphoric acid, or salts thereof, or a quaternary ammonium salt, and an acrylate or
methacrylate ester that contains an alkoxysilane functionality, or a monomer capable of copolymerization with a compound containing a trialkoxy silane functional group and
15 subsequent reaction with water to form a silanol group, and a desiccant component. The
absorbent binder desiccant composition is particularly suitable for use in manufacturing a
wide variety of humidity control articles.
A diversity of chemical compositions (polymers and cross-linking agents) besides of
multiple variants of control of cross-linking reactions are found in art in U.S. Patent
20 3,983,271 ;4,066,584 ; 4,320,040 ;4,418,163 ; 4,731,067 ;4,855,179 ; 4,880,868 ; 4,888,238
; 5,698,074 ; 5,997,791 ; 6,150,495 ; 6,162,541; 6,241,713 ;6,773,746 and 6,824,650.
iii) Processes with impregnation mass that contain biopolymers and cross-linking agents
Weerawarna et al. in US Patent 7,300,965 provides a mixed polymer network having
25 superabsorbent properties. The composition is obtainable by reacting a carboxyalkyl
cellulose and a synthetic water-soluble polymer having carboxylic acid or carboxylic acid
derivative substituents with a crosslinking agent. The cross-linking agent reacts with at least
one of the carboxyalkyl cellulose or water-soluble polymer to provide the network. Suitable
cross-linking agents include cross-linking agents that are reactive toward carboxylic acid
30 groups.
Representative organic cross-linking agents that are reactive toward carboxylic acid
groups include diols and polyols, diamines and polyamines, diepoxides and polyepoxides,
polyoxazoline functionalized polymers, and aminols having one or more amino groups and
one or more hydroxy groups.
5
Representative inorganic cross-linking agents that are reactive toward carboxylic acid
groups include polyvalent cations and polycationic polymers. Exemplary inorganic crosslinking agents include aluminum chloride, aluminum sulfate, and ammonium zirconium
carbonate with or without carboxylic acid ligands such as succinic acid (dicarboxylic acid),
5 citric acid (tricarboxylic acid), and butane tetracarboxylic acid (tetracarboxylic acid). Water
soluble salts of trivalent iron and divalent zinc and copper can be used as cross-linking
agents. Representative carboxylic acid cross-linking agents includes di- and polycarboxylic
acids. U.S. Patent 5,137,537; 5,183,707 and 5,190,563 describe the use of C2-C9
polycarboxylic acids that contain at least three carboxyl groups (e.g., citric acid and
10 oxydisuccinic acid) as crosslinking agents. Suitable polycarboxylic acid crosslinking agents
include citric acid, tartaric acid, malic acid, succinic acid, glutaric acid, citraconic acid,
itaconic acid, tartrate monosuccinic acid, maleic acid, 1,2,3-propane tricarboxylic acid,
1,2,3,4-butanetetracarboxylic acid, all-cis-cyclopentane tetracarboxylic acid, tetrahydrofuran
tetracarboxylic acid, 1,2,4,5-benzenetetracarboxylic acid, and benzenehexacarboxylic acid.
15 The cross-linking can be achieved by heating at a temperature and for a period sufficient to
effect the cross-linking. The carboxymethyl cellulose solution containing cross-linking
agent or synthetic water-soluble polymer and cross-linking agent can be air-dried or solvent
precipitated followed by cross-linking. Cross-linking time and temperature will depend on
the cross-linking agent and polymers used.
20 Sun et al. in U.S.Patent 6,689,378 presents methods of immobilizing uncomplexed
cyclodextrins and complexed cyclodextrins to polysaccharide containing substrates, such as
cellulose fibers by covalently bonding. The cellulose/cyclodextrin compositions can be used
in all types of cellulose fiber containing articles, such as tissues and personal care articles.
Useful polymeric anionic reactive compounds are compounds having repeating units
25 containing two or more anionic functional groups that will covalently bond to hydroxyl
groups of the substrate. Exemplary polymeric anionic reactive compounds include the
ethylene/maleic anhydride copolymers described in U.S. Patent 4,210,489. Vinyl/maleic
anhydride copolymers and copolymers of epichlorohydrin and maleic anhydride or phthalic
anhydride are other examples. Copolymers of maleic anhydride with olefins can also be
30 considered, including poly(styrene/maleic anhydride)
Copolymers and terpolymers of maleic anhydride that could be used are disclosed in
U.S. Patent 4,242,408.
The cross-linkable impregnation mass, similar to polymerizable systems in situ have
disadvantage that the cross-linking is not complete in conditions of thermal treatment
6
mentioned, existing permanent the possibility that during uses of textile products to extract
besides soluble polymer also cross-linking agent, this being more dangerous for the human
healthy comparatively with the monomers or polymerization auxiliary residues. Presence of
biopolymers in mixture for treating of textile materials, not contribute to improving the
5 chemical transformation yield that occurs during cross-linking. Referring to uses of
macromolecular cross-linking agents, these products being in their turn result of synthesis
processes are not mentioned their purity or the extractability in aqueous solutions used as
swelling media.
A particular drawback of known processes in the art for obtaining absorbent textiles
10 is that those products are not ecological. Majority of polymeric absorbents discussed above,
are products of synthesis, which because of their chemical structure have not the capacity of
biodegradation in specific active biological media, i.e. the domestic compost. Moreover,
absorbent textiles that contain biopolymers, although are biodegradable, have small values
of free absorbency. Another drawback of known absorbent textiles is that the polymer
15 network included in such textiles was obtained through the use of crosslinking agents that
might present health hazards to end users.
SUMMARY OF INVENTION
The present invention eliminates the disadvantages of processes known in art for
obtaining absorbent textiles, by providing a new process for treating textiles and forming new
20 textile composite article with improved water absorbance and biodegradability. The new
process makes use of an aqueous textile-impregnating polymeric composition in solution
form and containing at least two types of soluble polymers - a synthetic polymer and a natural
polymer, the composition being devoid of separate non-polymer crosslinking agent. The two
types of polymers are combined in a predefined ratio that is chosen such that when the textile
25 is impregnated with the polymeric composition and is exposed to heat treatment, the
polymers interpenetrate into the textile fibers and undergo self crosslinking into the textile.
The resulting composite textile in dry form has a free absorbance capability which is higher
by at least 10% when compared to the non-impregnated textile material, depending on the
liquid medium type that is in contact. The resulting textile is also characterized by high
30 biodegradability. More specifically, the resulting composite textile in dry form has a free
absorbance capability which is higher by at least 10%, preferably higher by at least 20%,
7
more preferably higher by 30%, 40% 50%, 60%, 70%, 80%, 90% or higher, when compared
to the non-impregnated textile material.
The terms fabric, textile, web, with or without being combined with the word
“material” are used in this specification interchangeably.
5 Another object of the invention is to provide a textile composite article comprising
fibers and polymers network interpenetrating the textile fibers, the polymers network
comprising natural polymer crosslinked to synthetic polymer in the absence of non-polymeric
crosslinking agent. The textile composite article has a water absorbance by at least 50%
higher in comparison to same textile without said polymers network interpenetrating into the
10 textile fibers.
Another object of the present invention is to provide a new type of polymeric
composition, in which the natural polymer activates the biodegradation of the synthetic
polymer and confers to the system superior biodegradability.
Another object of the present invention is to provide a new type of polymeric
15 composition made of at least two types of soluble polymers - a synthetic polymer and a
natural polymer, in which the natural polymer activates under heat the crosslinking of the
synthetic polymer and confers to a textile impregnated with such composition and dried,
superior free absorbance when exposed to aqueous liquids.
The natural polymer is a biopolymer that functions as both cross-linking agent of the
20 synthetic polymer and as activator of biodegradation processes.
Another object of the present invention is to provide a textile composite article having
an internal pattern of an interpenetrating polymeric material which penetrates at least partially
within the textile, leading to a pattern of impregnated areas in the textile. Following heat
treatment and drying of the impregnated textile, a textile composite article is obtained, having
25 improved water absorbance when exposed to aqueous liquids.
Another object of the present invention is to provide a new type of polymeric network
composition in stable aqueous solution which is compatible with different additives used in
the textile industry, for example plasticizers, active surface agents, dyers, perfumes, antiodorants, bacteriostatic agents etc., without affecting the water absorptive performance or
30 biodegradability of the textile material.
Another object of the present invention is to provide a new type of polymeric
network composition, in solution form, which is suited to be used as impregnation mass for
any nonwoven, woven or knitted textile materials made either from synthetic fibers
(polypropylene, polyester, polyvinyl alcohol, etc), from natural fibers ( cellulose, viscose,
8
cotton, wool, PLA, etc.), or from mixtures of synthetic and natural fibers, preferably with a
density of 30-90 g/m2
. The textile materials may be biodegradable by themselves such as for
example when made of PLA or may become biodegradable following impregnation with the
polymeric network and drying to form the composite absorbent textile of the invention.
5 Another object of the present invention is to provide a new type of polymeric aqueous
composition, which after heat-driven elimination of water from textile material impregnated
with such composition followed by self crosslinking, it gives rise to a composite absorbent
textile material with free spaces that permit fast access and absorption of liquid media in the
textile material when the textile is exposed to aqueous liquids.
10 The combination ratio of the two polymers in water is preferably chosen to obtain an
aqueous solution that is thermodynamically stable and suitable for impregnation into fabrics,
and that undergoes self-cross-linking under controlled thermal conditions (temperature and
time).
A textile material treated according to the invention with the polymeric composition is
15 characterized by improved water absorbance and biodegradability. With reference to
biodegradability, when the textile comes into contact with an aqueous biological media and
starts absorbency of this media, the composite polymeric material impregnated within the
textile is swelling and is transforming in a gel like material within the textile or on its surface
(textile function as a support).
20 According to other embodiments of the present invention, there is provided a
polymeric composite solution for use in forming an absorbent textile material that both in dry
form and gel form resulting after swelling in different aqueous media, it is still safe when in
contact with the human body and which is environmentally friendly, conferring a pronounced
ecologic character to textile materials used.
25 According to another aspect, the invention provides a process for the preparation of
polymeric composite aqueous solution to be used in improving water absorbency of
substrates e.g. fabrics treated with the polymeric composite, the process comprising the
following steps:
a) preparation of alkaline base solution
30 b) preparation of aqueous solution of synthetic polymer (SP) in acidic form, which is treated
afterwards with the alkaline solution from (a) to obtain the salt form, at a concentration of
between 1% and 10%, preferably between 2 and 5% by weight,
c) preparation under heating of aqueous solution of natural polymer NP at a concentration
between 1% and 10%, preferably between 2 and 5% by weight
9
d) mixing under heating and stirring the SP solution obtained in (b) in salt form, with the NP
solution obtained in (c) to obtain aqueous stable composite solution of polymers suitable
to be used as impregnation mass that confers high water absorbance to textile materials
and optionally
5 e) adding to the aqueous composite solution obtained in (d) at least one auxiliary material
selected from the list of plasticizers, surface agents, deodorants, perfume and
preservatives.
According to preferred embodiments, synthetic polymers (SPs) used in the invention
10 are made of monomers bearing carboxylic acid or carboxylic acid anhydride groups. More
specifically, SPs suitable to be used in this invention are linear or branched graft homo- or
copolymers made from vinyl acidic monomers such as acrylic acid, maleic anhydride,
itaconic anhydride and similar, optionally in association with other types of vinylic
monomers that do not necessarily contain carboxylic acid functions.
15 Preferably, the natural polymer is a biopolymer selected from a protein, soybean
protein, collagen, collagenic biopolymer, gelatin, collagen hydrolysate, albumin, guar or
starch and casein.
Preferably, the synthetic polymer is a copolymer based on maleic anhydride (maleic
acid), e.g. copolymers of styrene maleic anhydride (SMA), copolymers olefins with maleic
20 anhydride such as of isobutylene and maleic anhydride (e.g. commercially available
copolymers sold under the tradename Isobam™) or copolymers of methyl vinyl ether and
maleic acid (e.g. commercially available copolymers sold under the tradename Gantrez TM),
poly(decyl vinyl ether-alt-maleic anhydride), poly(ethyl vinyl ether-alt-maleic anhydride),
poly(maleic acid-co-propene), poly(n-butyl vinyl ether-alt-maleic anhydride),
25 poly(octadecene-alt-maleic anhydride), poly(propylene-alt-maleic acid) or poly(maleic acidco-dodecyl methacrylate).
According to preferred embodiments, the content of total free carboxylic acid groups in
the SPs of the invention range from 0.009 to 0.015 mole/gram SP. More specifically, the
free carboxylic acid groups of synthetic polymer SP are in salt state, corresponding to a
30 degree of neutralization between 49 to 99%, preferably between 60 to 95%, and most
preferably between 65 to 90%.
According to preferred embodiments, the average molecular weight of SP used in the
invention is from 50 KDa to 1,000 KDa, preferably from 100 KDa to 750 KDa, more
preferably from 150 KDa to 500 kDa.
10
According to preferred embodiments the natural polymer NP used in the invention is
a biopolymer selected from polypeptides, proteins, polysaccharides, polyesters and lignin (in
native forms or modified by chemical or enzymatic hydrolysis). More preferably the NPs
used in the invention are water soluble phospholipids such as lecithin, polypeptides or
5 proteins such as gelatin, albumin and the like; or polysaccharides such as cellulose, alginate,
dextran, chitosan, and the like; that have at least one of the following characteristics:
a) average molecular weight from 5 to 100 KDa preferably from 25 to 50 KDa, more
preferably from 75 to 100 KDa.
b) free chemical groups such as amine or hydroxyl in a relative concentration from 0.005
10 to 0.01 mole /grams NP, more preferably from 0.001 to 0.002 mole /grams NP.
c) hydrophilic, capable to form hydrogels in water environment and capable of
integration within the textile fibers.
According to preferred embodiments the biopolymer used in the invention has the
capability of cross-linking due to its NH2 or OH groups that crosslink to COOH groups in the
15 synthetic polymer under high temperature conditions and for selected periods of time, to form
ester and amide bonds between polymers skeletons. Furthermore, the biopolymer of the
invention activates the biodegradation of the textile impregnated with composite solution of
SP and NP of the invention.
According to further preferred embodiments, the polymers composite solution used in
20 the invention is a stable solution and may further contain at least one additive selected from
plasticizers, antibacterial agents, surfactants, deodorants, perfume, preservatives etc. The
polymers composite solution is suitable for impregnation into fabrics and also suitable for
self-cross-linking under controlled conditions of temperature and time.
Preferably, the textile density is between 30 to 90 g/m2 in order to allow sufficient
25 penetration of composite polymer solution into the textile material.
BRIEF DESCRIPTION OF THE DRAWING
The invention will now be described with reference to the drawings, wherein:
Figure -1 is a graph showing the correlation between the viscosity of SP-NP composite
30 solutions, the degree of neutralization of the synthetic polymer (SP) and solution stability.
The SP is represented by SMAC (Styrene Maleic Acid Copolymer) in salt form following
neutralization with sodium hydroxide. The natural polymer (NP) is represented by gelatin.
The following polymer solutions were tested: 100% SMAC; 90% SMAC and 10% Gelatin ;
70% SMAC and 30 % Gelatin. The SMAC used had different degrees of neutralization as
11
further explained in Example 1. From Figure 1 it is noted that the presence of the natural
polymer Gelatin leads to a decrease in the viscosity of the polymer composite solution if the
degree of neutralization of the synthetic polymer is between 30-60%. If the degree of
neutralization is greater than 60%, the presence of the natural polymer causes an increase in
5 the viscosity value of the composite solutions in comparison to same solution without natural
polymer. With reference to the stability of the composite polymer solutions, it is noted that
the composite solutions containing SMAC and gelatin are stable if the degree of
neutralization of the synthetic polymer SMAC is greater than 30%.
10 Figure-2 is a graph showing the influence of thermal treatment to which is subdue a nonwoven sample impregnated with the polymer composite solution containing synthetic
polymer and gelatin on the relative absorbency RQ1.
Figure- 3 is a graph showing the influence of the type of fibers on water absorbency for
textile impregnated with the polymer composite vs. a textile non-impregnated.
15 Figure- 4 is a schematic illustration of the process that occurs between a textile material and
the polymers network under heating conditions to provide the textile composite article of the
invention.
DETAILED DESCRIPTION OF THE INVENTION
20 Polymeric composite solution which is within the objects of this invention is a new
type of textiles treatment hereinafter termed Impregnation Composition (IC) which is used
for treating any type of textiles, preferably nonwoven textiles, to produce high absorbent
textile materials.
The polymer composite solution comprises synthetic polymer in the form of salt (SP),
25 natural polymer (NP) , additives (A) and water (W).
The ratio between a textile material TEX (before treatment) to impregnation
composition IC [ IC =SP+NP +A] is from 85 : 25 to 99 :1 % by dry weight.
The ratio between the synthetic polymer (SP) in salt form to natural polymer (NP) SP/
NP is from 70:30 to 95 :5 % by dry weight .
30 The ratio of additives (A) to polymers A/(SP+NP) is from 0.5 to 5% dry weight.
Water content in the composite polymer solution is from 79 to 99 % by weight.
The synthetic polymer salt, SP may be a commercially available polymer, having the
following characteristics:
12
a) linear copolymers or branched graft homo- or copolymers that contain vinyl acidic
monomers as: acrylic acid, maleic anhydride, itaconic anhydride and similar in
association or not with other types of vinylic monomers which does not contain
carboxylic groups.
5 b) content of total free carboxylic groups from 0.009 :0.0095 mol /gram to 0.01:0.0.15
mol/grams
c) Free carboxylic groups of synthetic polymer, SP are in salt state, corresponding to a
degree of neutralization between 49 -99 %, preferable between 60-95%, and most
preferable between 65-90%;
10 d) The salt state of synthetic polymer is obtained by using strong inorganic base
substances such as hydroxides, bicarbonates or carbonates of lithium, sodium,
potassium or ammonium, preferred hydroxides of lithium, sodium, potassium or
ammonium.
e) The average molecular weight of synthetic polymer, SP is from 50,000 Da to 1,000,000
15 Da, preferable from 100,000 Da to 750,000 Da, and most preferable from 150,000 Da to
500,000 Da.
The natural polymer, NP is preferably a commercially available biopolymer which
belongs to the following classes of substances: proteins, carbohydrates, bio-polyesters or
20 lignin (as native forms or modified by chemical or enzymatic hydrolysis); preferable are
proteins and carbohydrates integral soluble in water and which have the following
characteristics:
d) The average molecular weight from 5,000 to 100,000 Da preferable from 25,000 to
50,000 more preferable from 75,000 to 100,000 Da.
25 e) Free chemical functions as NH2 ; OH-CH2 ; OH-C6H3-5 ; as single type or more types
which have content from 0.001 to 0.002 preferable from 0.005 to 0.01 mol /grams.
Suitable additives, A are: plasticizers, antibacterial agents, active surface agents,
deodorants, perfume, preservatives etc., in quantities that are correlated with other properties
30 than absorbency.
The polymer composite solution is a stable solution of polymer materials SP and NP, without
phase separation under conditions of storage or ulterior processing.
Without being bound to theory, the polymer composite solution can interpenetrate
within the textile fibers and self cross-link under conditions of thermal treatment at
13
temperatures between 100 to 250oC and during periods of preferably between 2 to 30
minutes.
The resulting textile is a composite textile article having an internal pattern of an
interpenetrating polymeric material which penetrates at least partially within the textile.
Following heat treatment at temperatures being 100 to 250 o
5 C and drying of the impregnated
textile, a textile composite article is obtained, having improved water absorbance when
exposed to aqueous liquids.
A schematic representation of the process that occurs between a textile material and
the polymers network under heating conditions, to provide the textile composite article of the
10 invention is shown in Figure 4.
Preparation of polymeric composite aqueous solution to be used in improving water
absorbency of substrates e.g. fabrics treated with the polymeric composite, comprises the
following steps:
a) preparation of alkaline base solution
15 b) preparation of aqueous solution of synthetic polymer (SP) in acidic form, which is treated
afterwards with the alkaline solution from (a) to obtain the salt form, at a concentration of
between 1% and 10%, preferably between 2 and 5% by weight,
c) preparation under heating of aqueous solution of natural polymer NP at a concentration
between 1% and 10%, preferably between 2 and 5% by weight
20 d) mixing under heating and stirring the SP solution obtained in (b) in salt form, with the NP
solution obtained in (c) to obtain aqueous stable composite solution of polymers suitable
to be used as impregnation mass that confers high water absorbance to textile materials
and optionally
e) adding to the aqueous composite solution obtained in (d) at least one auxiliary material
25 selected from the list of plasticizers, surface agents, deodorants, perfume and
preservatives.
Textile materials to be used with the polymer composite solution include prefabricate
textile materials as: nonwoven, woven or any other type known in art and commercially
available, formed from synthetic fibers or natural fibers or a mixture of synthetic and natural
fibers. Preferred textile materials are made of synthetic fibers with a density of 30-90 g/m2
30 ,
preferable 40-80 g/m2
and more preferable 50-70 g/m2
.
Impregnation of the textile material is done using any equipment known in art, for
example spray devices ; foulard ; roll coating; reverse roll coating ; knife devices etc..
14
Further processing of the wet textile material depends of initial density of material
and of impregnation degree so chosen. For example:
a) if the density of the textile material has been initially higher than 70 g/m2
, then the wet
textile material is first dried in a stream of hot air at temperature of 50-90oC, preferable at
temperature of 55-85oC, and most preferable at temperature of 60-80o
5 C, so the solid
composite (textile + composite polymer) resulted to have a humidity content less than 12%
by weight , preferable less than 10% by weight, and most preferable less than 8% by weight
and then the supplementary thermal treatment in hot air steam at temperature of 90-180oC ,
preferable at temperature of 100-170oC, and most preferable at temperature of 110-160oC ,
10 during a period of 5- 180 minutes , preferable 10-150 minutes, and most preferable of 15-120
minutes;
b) if the density of textile material has been initially less than 70 g/m2
the wet textile material
is subdue to a single thermal treatment at temperature of 100-150 oC , during 180-300
seconds, preferable at temperature of 140-180 oC during 60-180 seconds and more preferable
at temperature of 200-250o
15 C during 30-120 seconds.
Following the thermal treatment the textile material is let to cool at room temperature
and in the end is packed.
The resulting textile material has improved water absorbance and can be used in a
variety of applications such as for example cleaning wipes, household or institutional
20 cleaning or maintenance, hand wipes, hand towels which allow a user to feel that the towel
remains dry, but which also allow for absorption of moisture, personal hygiene, cosmetic or
sanitary wipes, baby wipes, facial tissues, the core in panties or wound dressings, hygienic
absorbent pads and any other same application.
25 Test methods
1. Characterization of polymer solutions containing synthetic polymer, natural polymer and
auxiliary
- The viscosity of the solution was evaluated using a viscosimeter ViscoStar Plus,
Fungilab, Spain using a volume of solution correlated to the type of spindle L1 at 25 ° C
30 temperature.
- The stability of the polymer solution used for impregnation was assessed to be
stable or unstable if the analyte solution showed sediment after centrifugation of a volume of
25 ml solution at 5000 rpm for 30 minutes. Tests were performed with a laboratory centrifuge
GLC-2B Sorvall, Thermo Scientific at ambient temperature.
15
2. Free absorbency
The following measurements are made:
Mtex ,[grams] ,mass of the dried textile material used for impregnation by weighing at
a semi-analytical balance
5 Mtwstart ,[grams]- mass of wet starting material by weighing the sample
Mtid –[grams]- mass of drained textile material after impregnation
MIC-[grams]- mass of dried polymeric composite material found in the textile after
impregnation evaluated by the formula :
MIC= Mtex*IMD/100 , grams
10 The degree of impregnation of a textile material is established using the formula:
[IMD]dry= MIC /( Mtex+ MIC ) *100 ,%
Absorbency evaluation of textile materials:
2.1-Absorbency of textile material non-impregnated–Q1 consists of introducing the textile
sample, M-tex into a 150 ml volume of liquid to which the absorbance value is desired so that
15 the entire surface of the textile material is covered by the liquid and the contact is maintained
without shaking for 60 minutes. Ulterior, the material is removed from the liquid, it hangs in
a vertical position to drain excess liquid for 15 minutes. The drained textile material sample is
weighed and the value obtained is recorded as M-tex-wet.
Absorbency of non-impregnated textile material Q1 is obtained by using the formula:
20 Q1 = (M-tex wet-M-tex) /M-tex , ,(g/g)
2.2 . Absorbency of impregnated textile material Q2
The textile sample is weighted at technical balance obtaining the value Mtex.
Then is impregnated with a chosen mass of liquid:distilled water, an impregnating solution or
25 other type of solution by using a laboratory spray device. The wet material thus obtained is
weighted again and the value is Mtwstart . If this value is higher than the impregnation degree
(IMD) - pre-established the wet sample is subdue to a squeezing process with the aid of a
glass rod to eliminate the excess of impregnation liquid so that it finally is obtained a wet
sample with the mass Mtid . Next, the wet sample is kept for 30 minutes, in a closed glass
30 beaker to avoid evaporation of the liquid.
The absorbency of textile material sample is obtained with formula:
Q2-TEXIC = [Mtid – (Mtex+M IC )] / (Mtex+M IC ) , (g/g)
16
2.3. Relative absorbency
RQ represents the ratio between absorbency of an impregnated textile material Q2 and
absorbency of the same textile material non-impregnated Q1.
Relative absorbency is calculated by using the formula:
5 [RQ]1 = Q2 / Q1 or
[RQ]2 = [(RQ1)-1]*100 , (%)
EXAMPLES
10 Example 1
Stock solutions of synthetic polymer, natural polymer and inorganic base are prepared as
follows:
a) Stock of Synthetic Polymer Solution:
42.6 g of SMAc styrene / maleic acid copolymer [prepared as in U.S.Patent
15 7,985,819] in powder form having an 8% moisture content with an average molecular weight
of 450,000 Da containing 0.0091 mol / g free carboxylic groups together with 358 g of
demineralized water were added to a mixing vessel with agitation and the content was mixed
for 1 hour at 80 ° C to complete dissolution of the synthetic polymer and is end by cooling
the polymer solution to 40 °C. Finally, 400 g of SMAc polymer solution of 10 % by dry
20 weight is obtained.
b) Stock of sodium hydroxide solution
Is prepared 400 g of NaOH solution of 10% dry weight (from 98.9% pure
sodium hydroxide pellets) and demineralized water using a mixing vessel with agitation fitted
25 with a heating-cooling jacket.
c) Stock of natural polymer solution
400 g of gelatin type A solution with 200 Bloom and 14% moisture content
(as natural polymer-NP) of 10% dry weight were prepared by dissolving 46.5 g of natural
30 polymer in 354 g of demineralized water using a mixing vessel by stirring with a rotor speed
not higher than 60 rpm, during a period of 1 hour at a temperature of 40 oC so as to ensure the
perfect homogenization of the solution.
17
Further, the 3 types of solutions prepared above were used to prepare 3 sets of
composite solutions by diluting with demineralized water the stock solutions as follows:
Set-SOL1 without gelatin made up of 12 solutions of 3% concentration in which the synthetic
polymer has a different degree of neutralization between 0% and 110%.
5 Set-SOL-2 containing gelatin in proportion of 10% to SMAc consisting of 12 solutions of 3%
concentration in which the synthetic polymer has a different degree of neutralization between
0% and 110% and Set-SOL-3 which contains gelatin in a proportion of 30% to SMAc
consisting of 12 solutions of 3% concentration in which the synthetic polymer has a different
degree of neutralization ranging between 0% and 110%.
10 All composite solutions corresponding to the three sets were characterized in
terms of their viscosity and stability in the sense that the sample is unstable if it contains the
insoluble phase and that the sample is stable if it is a homogeneous solution without the
insoluble phase. The results obtained are presented in Table-1 and Figure-1.
Table-1 Influence of the degree of neutralization of the synthetic polymer SPS
15 and of the natural polymer NP content (as gelatin type A with 200 Bloom) in the composition
SP: NP) on solutions’ viscosity [ , (cP)] of 3% by dry weight.
Neutralization
degree of SP , [%]
Gel [0%]
  cP]
Gel [10%]
  cP]
Gel [30%]
  cP]
0 4.3 2000 2000
2 28.7 1900 1900
3 209.6 1800 1800
45 473.6 454.3 519.2
48 543.7 432.8 491.3
51 867.5 634.1 612.6
54 858 624.8 589.2
57 667.1 496.7 452.2
60 409.5 330.6 386.8
75 141.7 160 231.4
90 120.1 147.3 234.8
110 110.4 129.5 165.9
18
From Figure 1 it is noted that the presence of the natural polymer leads
to a decrease in the viscosity of the synthetic polymer if the degree of neutralization of the
synthetic polymer is between 30-60%. If the degree of neutralization is greater than 60%, the
presence of the biopolymer determines the increase in the viscosity value of the composite
5 solutions.
From the point of view of the stability of the composite solutions, this is dependent on the
degree of neutralization of the synthetic polymer. It has been noted that composite systems
containing SMAc and gelatin are stable if the degree of neutralization of the synthetic
polymer is greater than 30%.
10
Examples 2 to 5
In these examples, is presented the absorbency value to demineralized water (conductivity 2
micro S) of some nonwoven fabrics containing viscose fiber with density of 50 g/m2 with
15 different impregnation degree with polymeric solutions’ concentration of 1% by weight
containing SMAc (mentioned in Example 1) with neutralization degree of 59% generated
with NaOH and various values of gelatin content and which additionally contains 1.5% by
dry weight to the content of the polymeric composition.
The experiments were conducted as follows:
20 Textile materials having a mass of 0.5g were impregnated with composite solutions prepared
according to the method described in Example 1 by spraying with a laboratory device so as
finally to obtain the impregnation degree pre-established, IMD, to the dry mass of the sample
of dried fabric material. Further, the wet textile samples were placed in a hanging state in an
oven with air circulation, preheated to 180 ° C and are maintained at this temperature for 4
25 minutes. Finally, the sample was removed from the oven and allowed to cool at ambient
temperature. Then the textile material was subjected to the absorbency test according to the
methodology described in the chapter "Test methods".
Experimental conditions and results are shown in Table-2.
30 Table 2 The influence of gelatin content in the polymeric solution for impregnation and the
impregnation degree on the absorbency of impregnated nonwoven
Example cod [Q-tex]water Gelatin in IMD , % Q2-texic RQ1
19
Composite,% ,(g/g)
Exp-2 9.19 7.6 8 15.79 1.71
Exp-3 9.19 9.7 10 12.08 1.39
Exp-4 9.19 13.5 8 14.07 1.53
Exp-5 9.19 17.6 12 15.49 1.68
Examples 6-12
In these examples are presented the impregnation of a textile material consisting of viscose
fibers with a density of 50 g/m2 using a solution of synthetic polymer SMAc with
5 neutralization degree of 64% done by using NaOH, 3.6% gelatin to the polymeric composite
at degree of impregnation of 20% with thermal treatment of 200°C for 100 seconds using the
same oven with air circulation mentioned in the previous examples. Finally, the absorbency
of the textile sample was evaluated against various liquid media represented by simulated
fluid secreted by the human body (Margareth R.C. Marques et al, Simulated Biological Fluids
10 with Possible Application in Dissolution Testing, Dissolution Technologies AUGUST 2011,
1)
The results are presented in Table-3
Table-3 Influence of the liquid medium’s composition on the absorbency of textile materials
15 impregnated with polymeric composites containing synthetic polymer and gelatin
Examples Liquid media M-tex IMD Q1 Q2 tex
code [g] dry % [g/g] [g/g]
Exp-6
Distillated water
0.0002mS
0.5 15 29.03 50.48
Exp-7
Tap water
4 mS
0.5 15 16.20 28.17
Exp-8
Salt water 0.9%
15.4mS
0.5 15 5.89 10.24
Exp-9
Bovine Milk (3%)
0.5 15 5.11 8.88
Exp-10 Simulated Human 0.5 15 2.81 4.89
20
Sweat (1)
Exp-11
Simulated Wound
Fluids(1)
0.5 15 6.28 10.92
Exp-12
Simulated Saliva(1)
0.5 15 7.63 13.26
Example-13
In this example is presented the influence of the temperature and the time of the
thermal treatment at what is subjected a sample of textile material with a density of 50 g/m2
in
order to obtain an absorbent textile material on the relative absorption RQ1. The results are
presented in Figure 2.
The data obtained show that the thermal treatment of the impregnated fabrics must
be in such manner as to obtain the highest value for absorbency. The lower values of the
maximum result either because of a low crosslinking degree or because the degree of
crosslinking of the polymeric composite is too high.
Example 14.
This example shows the influence of the type of fiber from which the fabric is done subjected to
impregnation.
For this purpose, a composite polymer solution having the chemical composition coinciding with
Exp-2 was used.
Have been used textile materials from polypropylene fiber (PP-fiber) , polyester fibers (PETfiber) viscose fibers (Viscose-fiber).
The results obtained are presented in Figure 3.
Examples 15-16
In these examples is presented the influence of the type of biopolymer used for the preparation of
composite material according to the invention on the absorbency of a textile material using the
preparation technology for the composite from Example 1and the methodology of impregnation
of the textile material from example 3 .
Instead of gelatin have been used gum guar (G4129 Sigma Aldrich) and soluble starch (S9765
21
Sigma Aldrich).
Table-4 Influence of the biopolymer type (carbohydrates) on the absorbency of textile materials
impregnated with polymeric composites containing synthetic polymer and biopolymer
Example cod Natural
polymer
type
Natural
polymer in
composite,%
IMD , % Q2-texic
,(g/g)
Exp-15 Guar 1.8 19 16.96
Exp-16 Starch 2.3 28 20.44
ASPECTS IN THIS INVENTION
1. A polymer composite solution for treating any type of prefabricate textile material for
production of high absorbent materials. The treated materials are preferable nonwoven.
5
2. The polymer solution comprises synthetic polymer SP in salt form, natural polymer NP,
and optionally additives A and water W.
3. The ratio between prefabricate textile material TEX to impregnation composition IC =
10 (SP+NP +A is from 85 : 25 to 99 :1 % by dry weight.
4. The ratio between the synthetic polymer salt SP to natural polymer NP is SP : NP from
70:30 to 95 :5 % by dry weight.
15 5. The ratio between additives A to polymers (SP+NP) is 0.5 : 5% by dry weight.
6. Water content of polymer solution is 79 :99 % by weight.
7. The synthetic polymer SP preferably in salt form is a commercially available polymer,
20 with the following characteristics:
f) Configurations of synthetic polymer is :linear as copolymers or branch as graft homo-or
copolymers which contain vinyl acidic monomers as: acrylic acid, maleic anhydride,
22
itaconic anhydride and similar in association or not with other type of vinylic monomer
which is not contain carboxylic chemical functions.
g) content of total free carboxylic chemical functions from 0.009 :0.0095 mol /gram to
5 0.01:0.0.15 mol/grams
h) Free carboxylic chemical functions of synthetic copolymer SP are in salt state,
corresponding to a degree of neutralization between 49 -99% , preferable between 60-
95%, and most preferable between 65-90%;
i) The salt state of synthetic polymer is resulted by using inorganic substances with
10 intense basic character as hydroxides, bicarbonate or carbonate of lithium, sodium ,
potassium or ammonium, preferred being hydroxides
j) The average molecular weight of synthetic polymer SP is with value from 50,000 Da to
1,000,000 Da, preferable from 100,000 Da to 750,000 Da, and most preferable from
150,000 Da to 500,000 Da.
15
8. The natural polymer NP is preferably a commercially available biopolymer which belong
to the following classes of substances: proteins, carbohydrates, bio-polyesters or lignin (as
native forms or modified by chemical or enzymatic hydrolysis) ; preferable are the proteins
and carbohydrates integral soluble in water and which have the following characteristics:
20 a) The average molecular weight from 5,000 to 10,000 Da preferable from 25,000 to
50,000 more preferable from 75,000 to 100,000 Da
b) Free chemical functions as NH2 ; OH-CH2 ; OH-C6H3-5 ; as single type or more types
which have content from 0.001 to 0.002 preferable from 0.005 to 0.01 mol /grams
25 9. Suitable additives A to be used are plasticizers, antibacterial agents, active surface agents,
deodorants, perfume, preservatives etc., in quantities that are correlated with other properties
than absorbency.
10. The polymer composite solution is a stable solution without phenomena of phase
separation in conditions of storage or ulterior processing.
30 11. The polymer solution can generate three-dimensional macromolecular network material,
in dry state by cross-linking in the inner of fibrous mass, in conditions of thermal treatment at
temperature of 100-250oC during 2-20 minutes.
23
12. Process for the preparation of polymeric composite aqueous solution to be used in
improving water absorbency of substrates e.g. fabrics treated with the polymeric composite,
the process comprising the following steps:
a) preparation of alkaline base solution
5 b) preparation of aqueous solution of synthetic polymer (SP) in acidic form, which is treated
afterwards with the alkaline solution from (a) to obtain the salt form, at a concentration of
between 1% and 10%, preferably between 2 and 5% by weight,
c) preparation under heating of aqueous solution of natural polymer NP at a concentration
between 1% and 10%, preferably between 2 and 5% by weight
10 d) mixing under heating and stirring the SP solution obtained in (b) in salt form, with the NP
solution obtained in (c) to obtain aqueous stable composite solution of polymers suitable
to be used as impregnation mass that confers high water absorbance to textile materials
and optionally
e) adding to the aqueous composite solution obtained in (d) at least one auxiliary material
15 selected from the list of plasticizers, surface agents, deodorants, perfume and
preservatives.
13. Textile materials to be used are nonwoven, woven or any other type known in art and
commercial available, formed from synthetic fibers or natural fibers or a mixture of synthetic
20 and natural fibers, preferred being the textile materials formed from synthetic fibers with a
density of 30-90 g/m2
, preferable 40-80 g/m2
and more preferable 50-70 g/m2
.
14. The polymer composite solution is used as a treating agent to obtain absorbent textile
materials, as follows:
25 - impregnation of textile material using any equipment known in art, for example ( spray
devices ; foulard ; roll coating; reverse roll coating ; knife devices etc.) ;
The processing of wet textile material depends of initial density of material and of
impregnation degree so chosen:
a) if the density of textile material has been initially higher than 70 g/m2
the wet textile
material is first dried in current of hot air at temperature of 50-90o
30 C, preferable at
temperature of 55-85oC, and most preferable at temperature of 60-80oC, so the solid
composite resulted to have a humidity content less than 12% by weight , preferable less than
10% by weight, and most preferable less than 8% by weight and then the supplementary
thermal treatment in hot air current at temperature of 90-180oC , preferable at temperature of
24
100-170oC, and most preferable at temperature of 110-160oC , during a period of 5- 180
minutes , preferable 10-150 minutes, and most preferable of 15-120 minutes;
b) if the density of textile material has been initially less than 70 g/m2
the wet textile material
is subdue to a single thermal treatment at temperature of 100-150 oC, during 180-300
seconds, preferable at temperature of 140-180 o
5 C during 60-180 seconds and more preferable
at temperature of 200-250oC during 30-120 seconds.
Following thermal treatment, the treated textile material is let to cool at room temperature
and in the end is packed.
10 15. The resulting textile material with improved water absorbance can be used in a variety of
applications such as for example: cleaning wipes, household or institutional cleaning or
maintenance, hand wipes, hand towels which allow a user to feel that the towel remains dry,
but which also allow for absorption of moisture, personal, cosmetic or sanitary wipes, baby
wipes , facial tissues , hygienic absorbent pads and any other same application.
15
25
REFERENCES
Margareth R. C. Marques , Raimar Loebenberg , and May Almukainzi, Simulated Biological
Fluids with Possible Application in Dissolution Testing Dissolution Technologies, AUGUST
2011, 1
U.S. Patent Documents
2,988,539 Cohen,et al. June 13, 1961
3,393,168 Johnson ,et al. July 16, 1968
3,514,419 Durlow,et al. May 26, 1970
3,926,891 Gross,et al. December 16,1975
3,980,663 Gross; James R. September 14, 1976
3,983,271 Pangle, Jr. , et al. September 28, 1976
4,057,521 Gross; James R November 8, 1977
4,066,584 Allen , et al. January 3, 1978
4,155,957 Sasayama; Hiroharu May 22, 1979
4,210,489 Markofsky; Sheldon B. July 1, 1980
4,242,408 Evani , et al. December 30, 1980
4,320,040 Fujita , et al. March 16, 1982
4,418,163 Murakami , et al. November 29, 1983
4,537,590 Pieniak , et al. August 27, 1985
4,540,454 Pieniak , et al. September 10, 1985
4,573,988 Pieniak , et al. March 4, 1986
4,676,784 Erdman , et al. June 30, 1987
4,731,067 Le-Khac; Bi March 15, 1988
4,855,179 Bourland , et al. August 8, 1989
4,861,539 Allen , et al. August 29, 1989
26
4,880,868 Le-Khac; Bi November 14, 1989
4,962,172 Allen , et al. October 9, 1990
4,963,638 Pazos , et al. October 16, 1990
5,183,707 Herron , et al. February 2, 1993
5,280,079 Allen , et al. January 18, 1994
5,413,747 Akers , et al. May 9, 1995
5,567,478 Houben , et al. October 22, 1996
5,693,707 Cheng , et al. December 2, 1997
5,698,074 Barcus , et al. December 16, 1997
5,962,068 Tsuchiya , et al. October 5, 1999
5,997,791 Chou , et al. December 7, 1999
6,150,495 Chou , et al. November 21, 2000
6,162,541 Chou , et al. December 19, 2000
6,241,713 Gross , et al. June 5, 2001
6,417,425 Whitmore , et al. July 9, 2002
6,506,696 Goldstein , et al. January 14, 2003
6,645,407 Kellenberger , et al. November 11, 2003
6,689,378 Sun , et al. February 10, 2004
6,773,746
Bell; Otis Franklin August 10, 2004
7,300,965 Weerawarna , et al. November 27, 2007
7,985,819 Bucevschi et al July 26 , 2011
5
27
WE CLAIM:
1. Textile composite article comprising textile fibers and a polymers network
interpenetrating the textile fibers, said polymers network comprising natural polymer
crosslinked to synthetic polymer in the absence of non-polymeric crosslinking agent and said
5 textile composite article having a water absorbency by at least 10% higher in comparison to
same textile without said polymers network.
2. Textile composite article according to claim 1, being biodegradable.
3. Polymeric composite aqueous solution for use in improving water
absorbency of textile material treated with the polymeric composite solution, said polymeric
10 composite solution comprising a network of natural polymers and synthetic polymers having
monomers bearing carboxylic acid or carboxylic acid anhydride groups, in which said natural
and synthetic polymers in said composite solution undergo self-cross-linking under controlled
conditions of temperature and time and in the absence of non-polymeric crosslinking agent.
4. Polymeric composite aqueous solution according to claim 3, wherein said
15 textile material is of nonwoven, woven or knitted type and having a density between 30 to 90
g/m2
before being treated with said composite polymer solution.
5. Process for the preparation of the polymeric composite aqueous solution of
claim 3, said process comprising:
a) preparation of alkaline base solution
20 b) preparation of aqueous solution of synthetic polymer (SP) in acidic form,
which is treated afterwards with the alkaline solution from (a) to obtain the
salt form, at a concentration of between 1% and 10%, preferably between
2 and 5% by weight,
c) preparation under heating of aqueous solution of natural polymer NP at a
25 concentration between 1% and 10%, preferably between 2 and 5% by
weight
d) mixing under heating and stirring the SP solution obtained in (b) in salt
form, with the NP solution obtained in (c) to obtain aqueous stable
composite solution of polymers suitable to be used as impregnation mass
30 that confers high water absorbance to textile materials and optionally
e) adding to the aqueous composite solution obtained in (d) at least one
auxiliary material selected from the list of plasticizers, surface agents,
deodorants, perfume and preservatives.
28
6. Process according to claim 5, wherein said synthetic polymer (SP) is
selected from linear or branched graft homo- or copolymers made from vinyl acidic
monomers such as acrylic acid, maleic anhydride, itaconic anhydride and similar, optionally
in association with other types of vinylic monomers that do not necessarily contain
5 carboxylic acid functions.
7. Process according to claim 5, wherein said SP is a copolymer based on
maleic anhydride and/or maleic acid, preferably copolymers of styrene maleic anhydride
(SMA), copolymers of isobutylene and maleic anhydride (e.g. commercially available
copolymers sold under the tradename Isobam™) or copolymers of methyl vinyl ether and
maleic acid (e.g. commercially available copolymers sold under the tradename Gantrez TM 10 ).
8. Process according to claim 5, wherein said natural polymer (NP) is a
biopolymer selected from protein, soybean protein, collagen, collagenic biopolymer, gelatin,
collagen hydrolysate, albumin, guar or starch and casein.
9. Process according to claim 5, wherein said natural polymer (NP) is a
15 biopolymer selected from polypeptides, proteins, polysaccharides, polyesters and lignin (in
native forms or modified by chemical or enzymatic hydrolysis).
10. Process according to claim 5, wherein said natural polymer (NP) is a
biopolymer selected from water soluble phospholipids such as lecithin, polypeptides or
proteins such as gelatin, albumin, and the like; or polysaccharides such as cellulose, alginate,
20 dextran, chitosan, and the like.
11. Process according to claim 5, wherein said natural polymer (NP) has
amino and/or hydroxyl groups capable of cross-linking to COOH groups in SP under high
temperature conditions and for selected periods of time.
12. The textile composite article of claim 1 for use in absorbing products.
25 13. The use of claim 12, wherein said absorbing products are selected from
cleaning wipes, household or institutional cleaning or maintenance appliances, hand wipes,
hand towels, personal, cosmetic or sanitary wipes, baby wipes, facial tissues, hygienic
absorbent pads, panties, wound dressings and the like.
14. The polymeric composite aqueous solution of claim 3, wherein said
30 synthetic polymers (SP) are selected from linear or branched graft homo- or copolymers
made from vinyl acidic monomers such as acrylic acid, maleic anhydride, itaconic anhydride
and similar, optionally in association with other types of vinylic monomers that do not
necessarily contain carboxylic acid functions.
29
15. The polymeric composite aqueous solution of claim 3, wherein said
synthetic polymers (SP) are copolymers based on maleic anhydride and/or maleic acid,
preferably copolymers of styrene maleic anhydride (SMA), copolymers of isobutylene and
maleic anhydride (e.g., commercially available copolymers sold under the tradename
5 Isobam™) or copolymers of methyl vinyl ether and maleic acid (e.g., commercially available
copolymers sold under the tradename Gantrez TM).
16. The polymeric composite aqueous solution of claim 3, wherein said
natural polymers (NP) are a biopolymer selected from polysaccharides such as cellulose,
alginate, dextran, chitosan, and the like; polyesters and lignin (in native forms or modified by
10 chemical or enzymatic hydrolysis); guar; starch; water soluble phospholipids such as lecithin;
polypeptides or proteins such as gelatin, albumin, soybean protein, collagen, collagenic
biopolymer, collagen hydrolysate, and casein.
17. The polymeric composite aqueous solution of claim 3, wherein said
natural polymers (NP) have amino and/or hydroxyl groups capable of cross-linking to COOH
15 groups in SP under high temperature conditions and for selected periods of time.