Sheet-like structure of polyvinyl chloride, which is capable of absorbing water vapor and transmitting water vapor

This invention relates to a sheet-like structure of polyvinyl chloride or a copolymer of vinyl chloride, which is capable of absorbing water vapor and transmitting water vapor, with a uniformly incorporated additive composed of polymeric particles of at least one swellable, modified polymer. The invention also relates to a process for manufacturing the sheet-like structure.

The present invention relates to a sheet-like structure of polyvinyl 
chloride or a copolymer of vinyl chloride, which has an improved 
absorption capacity and water vapor transmission rate, and to processes 
for the manufacture of these sheet-like structures. 
Sheet-like structures of this type are used in various fields of 
technology; these include, for example, the use as leather substitutes 
(synthetic leather) for shoe upper material, upholstery covers and outer 
garments (leather garments and all-weather garments), and also as a tent 
material and for other covers. Processes for the manufacture of such 
sheet-like structures which are produced in most cases as self-supporting 
films or as multi-layer sheet-like structures (for example composed of a 
covering layer and a carrier layer) have been known for a long time (see, 
for example, Kunststoffhandbuch "Plastics Handbook", Volume II, parts 1 
and 2, "Polyvinyl Chloride" by K. Krekeler and G. Wick, Carl Hanser 
Verlag, Munich 1963). When these sheet-like structures are employed in one 
of the fields of application mentioned, it is one of the decisive demands 
made of the material that it be capable of absorbing water vapor and 
transmitting water vapor in order to provide, for example on the body, 
comfortable wearing and a good wearing climate. 
To obtain these required properties, three processes are primarly used 
(see, for example, B. M. Murphy, "Adsorptives Vinyl--Ein neues 
Schuhmaterial (Absorptive Vinyl--a new Show Material)", J. Coated Fabrics, 
Volume 4, page 240 et seq., 1975. 
1. Incorporation of soluble materials into the PVC and preparation of a 
film or a coating from the mixture by molding or a plastisol technology 
and solvent extraction of the finished sheet-like structure. The problem 
in this process is, above all, the washing-out step and the associated 
handling of large quantities of solvent. 
2. A chemical or mechanical expansion of PVC plastisol with the aid of foam 
stabilizers. The problems with the products manufactured in this way are, 
in particular, the poor physical properties (for example abrasion 
resistance and extension properties). 
3. Controlled sintering of a few PVC particles; in this process, however, 
very stringent demands are made on the control of the reaction conditions. 
In the article, mentioned in the previous section, "Adsorptives Vinyl--Ein 
neues Schuhmaterial (Absorptive Vinyl--a new Shoe Material)" a process for 
the manufacture of this material is also described on page 242. A 
microporous sheet-like structure which can absorb and transport water 
vapor and liquid water is produced by gelling from a PVC plastisol and an 
addition of finely particulate thermoplastic fillers. The material can be 
used as an inner lining for shoes, in particular shoes of synthetic upper 
material. 
German Pat. No. 967,403, discloses a process for the manufacture of a 
breathing synthetic leather from polyvinyl chloride (PVC), in the course 
of which process small amounts of high molecular weight organic substances 
which are swellable in water or organic solvents are incorporated in the 
customary anhydrous coatings containing PVC, plasticizer and pigment dyes, 
these substances being swollen in a little water or solvent. This 
composition is processed in the customary manner by applying heat to 
produce sheets, or fabrics or nonwoven webs are coated therewith; the 
following substances are proposed: starch, viscose, casein, gelatin, 
agar-agar, polyvinyl alcohol, polyamides, cellulose ethers and esters, 
polystyrene or other polyvinyl compounds. It is stated that the 
hydrophilic character of the synthetic leather material also can be 
controlled by admixing hydrophilic capillary-active fillers, such as, for 
example, cellulose fibers. 
DT-AS No. 1,014,960, discloses a process for the manufacture of synthetic 
leather which transmits air and gas. In this process, a filler which is 
swellable in water is uniformly incorporated into a mixture which contains 
one or more polymerizable organic compounds, for example unpolymerized 
and/or partially polymerized vinyl compounds. Advantageously, this filler, 
for example a swellable fiber material or starch, is to be impregnated 
with concentrated solutions of substances which are insoluble in the 
liquid, pasty mixtures and which decompose when hot with the formation of 
gases or are washed out with water. The mixture is polymerized before or 
after it has been applied to a textile base. 
A process for the manufacture of sheet-like structures which transmit water 
vapor and air is disclosed in Swiss Pat. No. 328,436. In this process, a 
paste which contains a polymer or copolymer of vinyl chloride is mixed 
with polyvinyl compounds which are composed at least in part of vinyl 
alcohol units (--CH.sub.2 --CHOH--) and which are dissolved in a 
vaporizable liquid. This mixture is spread out in a layer and the latter 
is subjected to a heat treatment, as a result of which the vaporizable 
liquid is evaporated and the composition gels. It should be possible to 
render the hydrophilic component, before, during or after the heat 
treatment, either sparingly soluble, insoluble or less swellable, for 
example by tanning, acetalization or cross-linking, so that it is not 
partially swollen or dissolved and washed out in an undesirable manner 
during the subsequent action of water. A treatment with water before or 
after gelling is considered to be very advantageous, and in some cases may 
even be essential. 
DT-OS No. 2,364,628 discloses a structure, rendered hydrophilic, of a 
fiber-forming and a film-forming water-insoluble polymer, which contains 
particles of a modified cellulose ether. The following are mentioned as 
polymers: regenerated cellulose (cellulose hydrate), cellulose acetate, 
polyalkylene, alkylcellulose, polyacrylonitrile, polyamide and polyester. 
The modified cellulose ethers are those, of which the mere degree of 
etherification would lead to water-soluble cellulose ethers and which are 
modified in such a way that, at least for the major part, they have become 
water-insoluble but have remained capable of absorbing water. The 
structure, rendered hydrophilic, carries the particles of modified 
cellulose ether in uniform distribution in its polymeric mass or has a 
surface covered by the particles. The uses as ion exchangers or as 
dialysis membranes or osmosis membranes are mentioned as technological 
fields of application for films manufactured in this way. 
It is the object of the present invention to provide a sheet-like 
structure, based on polyvinyl chloride (PVC) or corresponding copolymers, 
which is capable of absorbing water vapor and transmitting water vapor and 
which is improved as compared with the state of the art. 
The invention starts from a sheet-like structure of polyvinyl chloride or a 
copolymer obtained with vinyl chloride, which is capable of absorbing 
water vapor and transmitting water vapor, with a uniformly incorporated 
additive composed of polymeric particles. The sheet-like structure 
according to the invention comprises, as the additive, particles of at 
least one swellable, modified polymer. Swellable polymers are those which 
swell in aqueous liquids, in particular liquids having a water content of 
more than 50% by weight, or which swell as a result of water molecules 
coming into contact with them by other means (for example water vapor). 
The term "uniformly incorporated" is here to be understood as a 
statistical distribution. The polymer is insoluble in water, in particular 
to the extent of at least 50% by weight. Advantageously, the particles are 
of a size of .ltoreq.250 .mu.m, preferably of .ltoreq.150 .mu.m, and are 
in general present in a pulverulent or fibrous form. 
In a preferred embodiment, the sheet-like structure contains about 10 to 
30% by weight of the additive of the particles composed of at least one 
swellable, modified polymer. 
The following, for example, are suitable as swellable, modified, polymers 
for the additive in the materials according to the invention: 
Cross-linked polyalkylene oxide according to DT-OS No. 2,048,721; in the 
process for the manufacture of this product, water-soluble polyalkylene 
oxides are treated with ionizing radiation of sufficient intensity to 
effect cross-linking and to render the polymer insoluble. The polyalkylene 
oxide can here be irradiated in the solid state or in solution. 
The absorbent, cross-linked copolymer containing carboxyl groups according 
to DT-OS No. 2,507,011, obtained from an .alpha.,.beta.-unsaturated acid 
and an acetal of the general formula (CH.sub.2 .dbd.CH--CH.sub.2 
--O).sub.2 --CH--(CH.sub.2).sub.n --CH--(O--CH.sub.2 
--CH.dbd.CH.sub.2).sub.2 where n is 0, 1 or 2. Acrylic acid, methacrylic 
acid, itaconic acid, .alpha.-phenylacrylic acid or .alpha.-benzylacrylic 
acid are here particularly suitable as the .alpha.,.beta.-unsaturated 
acid; in the manufacture of this copolymer, 0.1% to 15% by weight of the 
acetal are advantageously used per 85% to 99.9% by weight of one of the 
unsaturated acids. 
A hydrocolloidal polymer according to U.S. Pat. No. 3,670,731 (=DT-OS No. 
1,642,072), which has been rendered water-insoluble by cross-linking and 
is suitable for absorbing liquids and also retaining them; certain 
polyacrylamides, alkali metal salts of hydrolyzed polyacrylamides and 
alkali metal salts of polystyrene sulfonic acids are mentioned in 
particular. 
A cross-linked, insoluble, physiologically harmless polymer, which is 
swellable in water, according to U.S. Pat. No. 3,669,103 (=DT-OS No. 
1,617,998), selected from the group comprising poly-N-vinylpyrrolidones, 
polyacrylamides, polyacrylic acid and polyglycols. 
Absorbent polymers which are, at least for the major part, water-insoluble 
and swellable with water and which have been manufactured by the process 
of German application No. P 25 41 035.9; these are manufactured by 
etherification, in a homogeneous phase, of polyhydroxymethylene in an 
aqueous-alkaline solution with an .alpha.-halogenocarboxylic acid and by 
reaction, before, during or after the etherification, with a cross-linking 
agent which in an alkaline medium is polyfunctional towards 
polyhydroxymethylene. 
In particular, the following swellable, modified carbohydrate derivatives 
can be used within the scope of the invention: alkali metal salts of 
carboxymethylcellulose, which are heat-treated and are swellable in water, 
according to U.S. Pat. No. 2,639,239; in the process for the manufacture 
of this product, the solubility of a water-soluble alkali metal salt of 
carboxymethylcellulose having a D. S. (=degree of substitution, i.e., the 
number of substituted hydroxyl groups on one anhydro-D-glucose unit) of 
0.5 up to about 1 is reduced by subjecting this dry salt, in finely 
divided form, to a temperature of about 130.degree. to about 210.degree. 
C., with highly swellable gel particles being obtained. 
Water-insoluble, heat-treated carboxyalkyl celluloses, which absorb and 
retain liquids, according to U.S. Pat. No. 3,723,413 (=DT-OS No. 
2,314,689); in the process for the manufacture of these products the 
procedure is that (a) cellulose materials are treated with 
carboxyalkylating reactants and in this way water-soluble 
carboxyalkylcellulose is formed which has an average degree of 
substitution of more than 0.35 carboxyalkyl radicals per anhydroglucose 
unit in the cellulose but which possesses poor properties with respect to 
the absorption and retention of liquids, (b) such a proportion of the 
carboxyalkylating reactants and the by-products formed during the reaction 
is removed that, relative to the weight of the water-soluble 
carboxyalkylcellulose, at least about 3% by weight thereof remain and (c) 
the carboxyalkylcellulose is subjected to a heat treatment in the presence 
of the remaining carboxyalkylating reactants and by-products of the 
reaction and, thus, is rendered water-insoluble, and excellent properties 
with respect to the absorption and retention of liquids are imparted to 
the carboxyalkylcellulose. 
Absorbent carboxymethylcellulose fibers which are suitable for use in fiber 
materials for absorbing and retaining aqueous solutions and are 
substantially water-insoluble, according to U.S. Pat. No. 3,589,364 
(=DT-OS No. 1,912,740); fibers of this type consist of wet-cross-linked 
fibers of water-soluble salts of carboxymethylcellulose having a D.S. of 
about 0.4 to 1.6 and possess the original fiber structure. Preferably, 
about 3-10% by weight of epichlorohydrin are employed as the cross-linking 
agent. 
Chemically cross-linked, swellable cellulose ethers, according to U.S. Pat. 
No. 3,936,441 (=DT-OS No. 2,357,079); these cross-linked cellulose ethers, 
in particular those obtained from carboxymethylcellulose, 
carboxymethylhydroxyethylcellulose, hydroxyethylcellulose or 
methylhydroxyethylcellulose, are manufactured by reacting the ethers, 
which in themselves are water-soluble, in an alkaline reaction medium with 
a cross-linking agent, the functional groups of which are the acrylamido 
group 
##STR1## 
the chloro-azomethine group 
##STR2## 
the allyloxy-azomethine group 
##STR3## 
or which is dichloroacetic acid or phosphorous oxychloride. 
Chemically modified, swellable cellulose ethers, according to U.S. Pat. No. 
3,965,091 (=DT-OS No. 2,358,150); these cellulose ethers which have not 
been modified by cross-linking are manufactured by reacting the ethers, 
which in themselves are water-soluble, in an alkaline reaction medium with 
a monofunctionally reacting compound which is described by one of the two 
general formulae which follow: 
##STR4## 
wherein R.sub.1 in the formula I denotes an hydroxyl group, an acylamino 
group or an esterified carbamino group, and R.sub.2 denotes hydrogen or a 
carboxyl group. 
Chemically cross-linked, swellable cellulose ethers, according to DT-OS No. 
2,519,927; these cross-linked cellulose ethers are manufactured by 
reacting the ethers, which in themselves are water-soluble, in an alkaline 
reaction medium with bis-acrylamido-acetic acid as the cross-linking 
agent. 
Free-flowing, hydrophilic carbohydrates, which are cross-linked by 
radiation and are swellable in water, according to DT-AS No. 2,264,027; 
these products are manufactured (in the case of certain other polymers, 
such as polyethylene oxide or polyvinyl alcohol, similar products also can 
be obtained by the reaction steps which follow) by: 
(a) mixing at least one water-soluble, pulverulent polymeric carbohydrate 
with such an amount of at least one pulverulent inert filler, the 
particles of which are smaller than those of the carbohydrate, and in such 
a way that a substantial part of the surface of the pulverulent 
carbohydrate is covered, (b) while the mixing is continued, contacting the 
mixture, while stirring thoroughly, with a finely divided water spray in 
such an amount that the mixture is preserved in the form of free-flowing 
particles, and (c) then subjecting the resulting mixture to ionizing 
radiation until the polymeric carbohydrate is cross-linked. 
Chemically cross-linked or otherwise modified swellable starch ethers, 
according to German application No. P 26 34 539.1; these special starch 
ethers are manufactured by, for example, carrying out, as the 
modification, a cross-linking with a cross-linking agent which carries the 
following functional group which is reactive towards hydroxyl groups: 
##STR5## 
or which is phosphorous oxychloride. The procedure in another mode of 
manufacture is that the modification is carried out using a compound which 
is monofunctionally reactive under the stated conditions towards the 
hydroxyl groups of starch or of the starch ether and which is described by 
one of the general formulae which follow: 
##STR6## 
R.sub.1 being CH.sub.3 or H, R.sub.2 being H and R.sub.3 being CH.sub.3, 
CH.sub.2 --OH, an N-methylene-acylamido group with 1 to 3 C atoms, an 
esterified N-methylene-carbamido or N-carboxymethylene-carbamido group 
with 2 to 7 C atoms; or R.sub.2 and R.sub.3 being CH.sub.3 or CH.sub.2 OH 
and R.sub.4 and R.sub.5 being H; or R.sub.4 being H and R.sub.5 being 
CH.sub.3 ; or R.sub.4 and R.sub.5 being CH.sub.3. 
Alkali metal salts of carboxymethyl cellulose, having an increased 
absorption capacity and retention capacity, according to U.S. Pat. No. 
3,678,031 (=DT-OS No. 2,151,973). Although the etherifying agents here 
employed contain carboxyl groups and would lead to a normally soluble 
cellulose ether, the conditions of the reaction are selected so that 
alkali metal salts of carboxymethylcellulose, having a D.S. of 0.4-1.2, a 
water soluble fraction of &lt;35%, a water retention value (WRV) of about 
1,000 to 7,000 and a salt water retention value of about 400 to about 
2,500 are formed. 
Water-insoluble carboxymethyl celluloses, such as are described in German 
Pat. No. 1,079,796, and DT-AS No. 1,151,474, i.e., those which have a D.S. 
of 0.05 to 0.3 and those which are substantially water-insoluble and 
likewise have a low D.S. 
Water-insoluble, more highly polymerized carboxymethylcellulose or 
carboxyethylcellulose with a significant content of free carboxyl groups, 
according to British Pat. No. 725,887 (=German Pat. No. 1,037,076), which 
are rendered water-insoluble by heating the water-soluble acid compounds 
to 80.degree. C. to 177.degree. C. 
Phosphorylated cellulose fibers, according to DT-OS No. 2,447,282, such as 
can be produced by a reaction of cellulose pulp with urea and phosphoric 
acid under the action of heat, a subsequent acid hydrolysis and ultimately 
a conversion into the form of a salt. 
Dry, solid, water-insoluble absorbents, which are swellable with water, 
according to DT-OS No. 2,609,144, which consist of an ionic complex of a 
water-insoluble anionic polyelectrolyte and a cation of a metal which is 
at least 3-valent; suitable polyelectrolytes are polyacrylic acid, starch 
derivatives or cellulose derivatives. 
Cellulose graft polymers, according to DT-OS No. 2,516,380, which are 
manufactured by grafting side chains of those polymer radicals onto the 
cellulose which are selected from the ionic and non-ionic polymer 
radicals. For example, polyacrylic acid, sodium polyacrylate, 
polymethacrylic acid, potassium polymethacrylate, polyvinyl alcohol 
sulfate, polyphosphoric acid, polyvinylamine, poly-(4-vinylpyridine), 
hydrolyzed polyacrylonitrile, polymethyl methacrylate, polyvinyl acetate, 
polystyrene or polybutadiene are suitable for this purpose. 
Granulated, water-insoluble alkali metal carboxylate salts of 
starch/acrylonitrile graft copolymers, according to U.S. Pat. No. 
3,661,815, which are manufactured by saponifying starch/acrylonitrile 
graft copolymers with a base in an aqueous-alkaline medium. 
Modified cellulose material, having an improved retention capacity both for 
water and physiological fluids, according to DT-OS No. 2,528,555, which is 
manufactured by grafting an olefinically unsaturated, polymerizable 
monomer with hydrolyzable functional groups or a monomer carrying 
functional carboxyl groups onto a fibrous cellulose material and 
hydrolyzing the grafted product or treating the latter with alkali in 
other ways. In this process, the product is first converted to the state 
of maximum swelling, is then acidified to a pH value at which it is in the 
state of minimum swelling, is then converted to the form of a salt under 
conditions which do not effect swelling, and is finally dried. 
Modified polysaccharide, according to DT-OS No. 2,647,420, manufactured 
from a polysaccharide, acrylamide, another vinyl monomer and a divinyl 
monomer, under the conditions of a free radical reaction.

The processes for the manufacture of sheet-like structures from PVC or a 
copolymer obtained with vinyl chloride (VC) are known. The sheet-like 
structure here can be a self-supporting film or it can be produced by 
coating or impregnating a base of natural or synthetic fiber material, 
non-woven textile materials or webs of synthetic resin. Preferably, the 
following bases are used for coating: 
Woven or non-woven textile materials composed of one or more components, 
for example of synthetic fibers, such as polyamides, polyesters, 
polyacrylonitrile, PVC, polyolefins and polyamino acids, and also of glass 
fibers, regenerated fiber, such as viscose fibers, acetate fibers and the 
like, of natural fibers, such as cotton, silk, wool, linen and collagen 
obtained by abrading natural leather; or sheet-like materials which are 
composed of one or more components, for example of synthetic resins, such 
as polyamides, polyesters, polyacrylonitrile, PVC, polyolefins, and 
polyamino acids, or of natural leather, from which the silvery surface has 
been removed, or of collagen obtained from waste leather, natural rubber 
and synthetic rubber. 
When carrying out the Examples, the two processes described in the 
following text were in particular (parts are parts by weight): 
1. Heating (at about 170.degree. C.) and molding of soft PVC powders by 
sintering, for example in the high-frequency process, to give films or 
coatings of other types (see, for example, Kunststoffhandbuch "Plastics 
Handbook", Volume II, part 2 page 69, et seq., 1963). A soft PVC powder of 
this type can, for example, consist of 58-65 parts of PVC (for example of 
K value 70), 42-30 parts of plasticizer (for example a phthalate 
plasticizer of medium gelling power), 0-5 parts of a viscosity reducer, 
0.5-2 parts of stabilizers, 0.1-3 parts of pigments, and 20-10 parts of 
fillers. 
2. Spread-coating of PVC pastes, in particular PVC plastisols (see, for 
example, Kuntstoffhandbuch "Plastics Handbook", Volume II, part 1, page 
397 et seq. and 411 et seq., 1963). 
A material of this type which can be used for spread-coating can have, for 
example, one of the following compositions (S-PVC=suspension PVC, 
E-PVC=emulsion PVC): 
2.1 Base Coat 
53-56 parts of E(S)-PVC 
40-42 parts of phthalate plasticizer of medium gelling power (for example 
di-2-ethyl-hexyl phthalate or a mixture of this with diisononyl phthalate) 
4-5 parts of phthalate plasticizer of high gelling power (for example 
di-butyl phthalate) 
5-2% of heat stabilizer(s) 
0-x parts of pigment(s) 
0-5 parts of filler(s) 
2.2 Filling coat or middle coat 
58-65 parts of E-PVC or S-PVC (K value of about 70) 
30-42 parts of plasticizer 
0-5 parts of viscosity reducer 
0.5-2% of stabilizer(s) 
0.1-3 parts of pigment(s) 
10-20 parts of filler(s) 
2.3 Top coat 
65-70 parts of E-PVC (K valve of about 80) 
26-32 parts of plasticizer 
3-4 parts of viscosity reducer 
0.5-2% of stabilizer(s) 
0.1-3 parts of pigment(s) 
5-10 parts of fillers(s) 
To manufacture the sheet-like structures according to the invention, the 
particles of at least one modified, swellable polymer are added, 
preferably in a proportion of 10 to 30% by weight, to the base 
compositions which are to be processed and which consist, for example of 
soft PVC powder or a soft VC copolymer powder or of a PVC paste or a VC 
copolymer paste, before shaping or spreading, and the particles are 
uniformly distributed therein; the mixture is then shaped or spread. 
The sheet-like structures according to the invention have a high capacity 
for the absorption of water vapor and the transmission of water vapor, 
which far exceeds a mere transport effect by the incorporated particles. 
Furthermore, the sheet-like structures are also able to release the 
absorbed water vapor again under certain conditions, for example when 
placed under different climatic conditions. 
Because the properties of the sheet-like structures are not merely the 
result of the significantly detectable effect of the addition of the 
particles of at least one swellable, modified polymer, but also depend, 
inter alia, on the thickness of the film or of the coating, the latter is 
advantageously prepared in a thickness of about 0.05 to 0.5 mm. 
The sheet-like structures according to the invention, having the aforesaid 
properties, are suitable, for example, for use as a self-supporting film 
or as a coating on a base, in particular as a leather substitute 
(synthetic leather) for shoe upper material, upholstery covers, bag goods 
and outer garments (leather garments and all-weather garments) or as a 
covering, such as a tent material or a tarpaulin. 
In FIG. 5 of the drawings, the behavior of the different natural and 
synthetic materials towards moisture is shown for comparison, in 
particular in such a way that the moisture content of the particular 
sample was measured as a function of the relative humidity acting on the 
sample at 20.degree. C. This shows that chemically cross-linked 
carboxymethylcellulose, which represents a selected example of a modified 
swellable polymer, in combination with the measured moisture cycle 
according to Example 1, is very suitable for use in the materials 
according to the invention, in particular when these are used as a leather 
substitute under physiological conditions (for example as a shoe upper 
material or as an outer garment material). 
The parameters used in the description and the examples for characterizing 
the sheet-like structures according to the invention and the swellable 
modified polymers present therein are to be understood as meaning the 
following: 
WRV--Water retention capacity of the swellable modified polymer, in % by 
weight, measured against 1,600 times the acceleration due to gravity, 
relative to its water-insoluble fraction; WRV is determined after 
immersing the sample in water. 
WUA--Water-insoluble fraction in the swellable modified polymer. 
DS--Degree of substitution, i.e., the number of substituted hydroxyl groups 
on the anhydro-D-glucose units, from 0.0 to 3.0. 
SV--Absorbency of the swellable modified polymer for a 1% by weight NaCl 
solution, in NaCl solution, in % by weight, relative to its total weight; 
SV is determined after 1% by weight aqueous NaCl solution has been 
absorbed by the sample up to saturation. 
WA--The water absorption is determined by suspending the sample in liquid 
water. 
WDD.sub.PFI --Water vapor transmission rate (in accordance with W. Fischer 
and W. Schmidt, "Das Leder (Leather)", E. Roether-Verlag Darmstadt, 27, 87 
et seq. (1976)). Inside the apparatus there is a temperature of 32.degree. 
C., and the sample is under standard climatic conditions--unless otherwise 
stated--of 20.degree. C./65% relative humidity, these conditions being 
always kept constant by means of a gentle stream of air from a fan mounted 
above the apparatus. The free testing surface is 10 cm.sup.2. Inside the 
apparatus, the water at 32.degree. C. and the atmosphere above the water, 
which is saturated with water vapor, are also kept in continuous motion 
with the aid of a magnetic stirrer. To determine the WDD, the weight loss 
of the test vessel with the sample is determined. WDD is expressed in 
mg/cm.sup.2 .multidot.x hours (in most cases x is 1, but it also can be 8 
or 24). 
WDD.sub.DIN --Water vapor transmission rate, gravimetric process for 
determining the WDD (according to DIN 53,122 of November 1974; this 
factually agrees with ISO/R 1195-170 "Plastics, Determination of the water 
vapor transmission rate of plastics film and thin sheets, Dish Method"). A 
dish with an absorbent is sealed by the sample with the aid of wax and 
stored in moist climatic conditions. The amount of water vapor which is 
transmitted through the sample is calculated from the weight increase of 
the dish as soon as this increase becomes linear with time. The water 
vapor transmission rate WDD according to this standard is that amount of 
water vapor in g which is transmitted in 24 hours (1 day) under defined 
conditions (temperature, gradient of the atmospheric humidity) through 1 
m.sup.2 of surface area of the sample. 
WDA--Water vapor absorption (see also WDD.sub.PFI). The water vapor 
absorption is carried out simultaneously with the measurement of 
WDD.sub.PFI, by determining the increase in weight of the sample; unless 
otherwise stated, the sample is permeable with respect to the outside 
climatic conditions, i.e., it is not covered. 
Flexural strength--Measurement of the permanent flexural strength of 
light-weight leathers and their top layers (I.U.P./20 of the 
Internationale Union der Leder-Chemiker-Verbande "International Union of 
Associations of Leather Chemists", see "Das Leder (Leather)", E. 
Roether-Verlag, Darmstadt, 15, 87 (1964) and 26, 163 (1969)). The leather 
sample is folded and, in this state, its two ends are clamped into the 
test instrument. One clamp is stationary and the other moves to and fro, 
so that the fold moves up and down along the leather sample. The leather 
sample is tested at intervals in order to establish whether damage has 
occurred thereon. The test can be carried out with dry samples, 
conditioned samples or samples which have been moistened in a certain way. 
The dry experiment is intended to test the leather and its finishing. The 
wet experiment solely serves to assess the finishing. 
Tensile strength--Measurement of the tensile strength in a tensile test 
(according to DIN 53,328 of December 1970, which factually agrees with the 
I.U.P./6 process of the Internationale Union der Leder-Chemiker-Verbande 
"International Union of Associations of Leather Chemists", see "Das Leder 
(Leather)", E. Roether-Verlag Darmstadt, 10, 14 (1959)). The tensile 
strength .rho..sub.B is the quotient of the measured maximum force in kp 
and the initial cross-section of the sample in cm.sup.2. 
The invention will be further illustrated by reference to the following 
specific examples: 
EXAMPLE 1 
The moisture cycles of three different swellable, modified polymers are 
investigated over a period of several days. A certain amount of the 
polymer is first stored for at least 24 hours under standard climatic 
conditions (temperature of 23.degree. C., 50% relative atmospheric 
humidity) and weighed. In a constantly recurring rhythm, the procedure is 
then as follows: the polymer sample is kept for 8.0 hours under moist 
climatic conditions (temperature 30.degree. C., 100% relative atmospheric 
humidity), is weighed, is then again kept for 16.0 hours under the 
standard climatic conditions (23.degree. C., 50% relative atmospheric 
humidity) and is weighed again. The measured values obtained are plotted 
in a coordinate system (FIG. 1); the increase in weight in % by weight is 
recorded on the ordinate and the time in hours is recorded on the 
abscissa. The line designated as -- in FIG. 1 represents the moisture 
cycle of a mixture cross-linked with bisacrylamido-acetic acid, of a 
quaternary cellulose-ammonium salt and cellulose, having WRV=1,160, WUA=98 
and SV=950, the line designed as --- represents the moisture cycle of a 
mixture of carboxymethyl starch and carboxymethylcellulose hydrate, each 
cross-linked with bisacrylamido-acetic acid, having WRV=11,250, WUA=85.1 
and SV=1,920, and the line designated as 
.multidot..multidot..multidot..multidot. represents the moisture cycle of 
a carboxymethylcellulose, cross-linked with bisacrylamidoacetic acid, 
having WRV=3,270 and WUA=97. The comparison of the individual moisture 
cycles shows that the moisture absorbed by the particular swellable, 
modified polymer can be repeatedly released again under certain 
conditions. This property is of great importance for, for example, the 
incorporation of these polymers into films which can be used in shoe upper 
material or for sheet-like structures of other types; this is because, for 
example, a shoe is worn for a certain time during which the shoe upper 
material is provided from the inside with a certain amount of moisture by 
the foot; during rest periods (for example during the night) the shoe 
upper material should be able to release this moisture again to its 
surroundings. 
EXAMPLES 2 TO 5 
The water absorption (WA) values or the water vapor absorption (WDA) values 
of 0.5 mm thick films, prepared from grey or brown PVC powder with varying 
proportions of a swellable, modified polymer, are determined (see Table 
I). The WA was determined by suspending the film in water, and the WDA was 
determined under climatic conditions of 32.degree. C. and 100% relative 
humidity. The flexural strength of the modified films is high in the case 
of those of Examples 2-4 (up to 120,000 folds without cracks), and in 
those according to Example 5 the flexural strength is poor (cracks already 
starting at 500 folds). The tensile strength is reduced only by about 15% 
in the case of the films according to Examples 2-4, and in the films 
prepared according to Example 5 it is reduced rather more. 
EXAMPLES 6 TO 23 
The WA values or WDA values of 0.3 mm thick films, prepared from PVC with 
different types of a swellable, modified polymer, are determined (see 
Table II). The WA was determined by suspending the film in water, and the 
WDA was determined under different climatic conditions. 
Examples 6 to 14: films from PVC plastisol 
Examples 16 to 19: films from brown PVC powder 
Examples 20 to 23: films from brown PVC powder with an additon of 3% by 
weight of blowing agent. 
EXAMPLES 24 TO 28 
The WA values, the tensile strength and the flexural strength of films (0.3 
mm), prepared from PVC plastisol (Examples 24 to 27) or grey PVC powder 
(Example 28) and with the addition of varying amounts of a swellable, 
modified polymer, are determined and compared with those of films without 
such an addition (see Table III). 
EXAMPLES 29 TO 31 
The values of the water vapor transmission rate WDD.sub.PFI and, in some 
cases, the WDA values of 0.1 mm thick (Examples 29 and 30) or 0.3 mm thick 
(Example 31) films, prepared from brown PVC powder with the addition of 
varying amounts of a swellable, modified polymer, are determined and 
compared with those of leather (see Table IV). 
EXAMPLE 32 
The water vapor absorption (WDA) and the water vapor transmission rate 
(WDD.sub.PFI) of films prepared from PVC plastisol are determined as a 
function of the layer thickness of the film and a proportion of a 
swellable, modified polymer (CMC crosslinked with bisacrylamidoacetic acid 
and having DS=1.02, WRV=542, WUA=83.8, and SV=1,130, sieved to a fineness 
of .ltoreq.125.mu.). In the coordinate system of FIG. 2, the values of the 
water vapor absorption (WDA) are plotted on the ordinate, and the 
quantitative proportion of swellable, modified polymer in the film is 
plotted on the abscissa. It is apparent that the water vapor absorption 
rises both with an increasing proportion of additive and with increasing 
layer thickness. However, according to FIG. 3, the water vapor 
transmission rate (WDD.sub.PFI) rises indeed with an increasing proportion 
of additive, but it falls with increasing layer thickness. If the two 
measurements (see FIG. 4) are directly compared with one another 
graphically, it can be seen that there is a correlation, which in an 
individual case can be determined within certain ranges, between the 
parameters layer thickness and proportion of swellable, modified polymers. 
Thus, it appears to be hardly sensible, for example, to increase the layer 
thickness of the film to significantly more than 0.5 mm, and likewise the 
proportion of swellable, modified polymers should most advantageously be 
in the range from about 10 to 30% by weight, inter alia also in order not 
to modify the mechanical properties of the film excessively. 
EXAMPLES 33 TO 40 
The WDA values and WDD.sub.PFI values (see Table V) of 0.2 mm thick films 
from PVC plastisol with an identical added amount of swellable, modified 
polymers are determined under various climatic condtions (Examples 33 to 
36). In Examples 37 to 40, the amount added is varied and moreover, 
although the polymer used is of the same chemical type, the pH of the 
liquid precipitant medium (the manufacture of the cross-linked CMC is 
carried out under alkaline conditions and acetic acid is subsequently 
added to the reaction medium, see, for example, U.S. Pat. No. 3,936,411 
(=DT-OS No. 2,357,079) is adjusted not to a pH value of 6, as in Examples 
33 to 36, but to a pH value of 8. In particular, these particles of 
cross-linked CMC (Examples 37 to 40) can be more readily incorporated 
mechanically into the film composition. 
COMATIVE EXAMPLES V1 TO V10 
The water vapor absorption (WDA) values and water vapor transmission rate 
(WDD.sub.PFI) values of 0.2 mm thick films, prepared from PVC plastisol 
and having various additions of unmodified carbohydrates or carbohydrate 
derivatives, are determined (see Table VI), in order to prove in 
particular that the results, obtained in the preceding examples on the 
films according to the invention, are not to be ascribed to a mere 
transport effect of the incorporated particles of modified, swellable 
polymers. 
EXAMPLES 41 TO 44 AND COMATIVE EXAMPLES V11 to V13 
The WDA values and WDD.sub.PFI values of 0.2 mm thick films, prepared from 
PVC plastisol with a addition of a modified swellable polymer, are 
determined in measuring periods of varying lengths (Table VII, Examples 41 
to 44). 
It is found here that, above all, the water vapor transmission rate, and 
also the water vapor absorption (one measurement being exceptional) rise 
with an increasing duration of measurement not only in absolute terms but 
also when reduced to the same base time (1 hour). For comparison, the WDA 
values and WDD.sub.PFI values of commercially available materials (V11 to 
V13) are listed. 
EXAMPLES 45, 46 AND COMATIVE EXAMPLES V14 to V22 
The water vapor transmission rate (WDD) values, obtained by a different 
method, of 0.2 mm thick films, prepared from PVC plastisol without an 
addition (V14), with an addition according to the invention (Examples 45, 
46) and with an addition not according to the invention (V15 to V22) are 
determined. The values determined by this method also show that the 
increased water vapor transmission rate of the films according to the 
invention cannot be ascribed to a mere transport effect of the 
incorporated particles. 
EXAMPLES 47 TO 55 
The water vapor absorption (WDA) and the water vapor transmission rate 
(WDD.sub.PFI) of 0.2 mm thick films, prepared from PVC plastisol with an 
addition of swellable modified polymers of the most diverse type, are 
determined (see Table IX). The comparison of these results with, for 
example, those of Table VI (addition of particles of unmodified 
carbohydrates) also shows again the significant increase. 
TABLE I 
__________________________________________________________________________ 
WA (%) within a 
WDA at 32.degree. 
C./100% 
Swellable, modified polymer period of relative humidity 
Exam- Quantity 1 4 24 
ple Type Modifier 
% DS WRV WUA SV hour 
hours 
hours 
(mg/cm.sup.2 . 
__________________________________________________________________________ 
hour) 
2 Carboxy- 
bis-acrylamido- 
10 -- 2,700 
92.2 
1,600 
-- -- -- 5.0 
(grey 
methyl- 
acetic acid 
PVC) starch 
(cross-linked) 
(CMS) 
3 CMS bis-acrylamido- 
20 -- " " " 4.8 7.8 17.7 
-- 
(grey acetic acid 
PVC) (cross-linked) 
4 CMS bis-acrylamido- 
20 -- " " " 6.5 9.2 23.2 
-- 
(brown acetic acid 
PVC) (cross-linked) 
5 carboxy- 
vinylsulfon- 
10 0.42 
17,040 
52.4 
1,230 
-- -- -- 7.7 
(grey 
methyl- 
amide (uncross- 
PVC) cellulose 
linked) 
(CMC) 
grey -- -- -- -- -- -- -- -- -- 0 0 
or 
brown 
PVC 
without 
an 
addi- 
tion 
__________________________________________________________________________ 
TABLE II 
__________________________________________________________________________ 
WDA 
32.degree. C. 
100% rela- 
at 20.degree. C., 65% 
tive humid- 
relative humidity 
Swellable, modified polymer WA in % 
ity (mg/ 
in % 
Exam- Quantity 1 3 cm.sup.2. 8 
1st 2nd 
ple Type Modifier 
% DS WRV WUA SV day 
days 
hours day day 
__________________________________________________________________________ 
6 CMS bis-acrylamido 
25 0.67 
3,800 
87.7 
1,800 
16.7 
22.2 
4.6 0.62 0.59 
acetic acid 
(cross-linked) 
7 CMS bis-acrylamido 
25 -- 2,700 
92.2 
1,600 
16.8 
23.7 
4.2 0.74 0.74 
acetic acid 
(cross-linked) 
8 carboxy- 
bis-acrylamido 
25 0.37 
8,720 
67.2 
980 
71.6 
74.7 
25.7 0.66 0.57 
methyl- 
acetic acid 
cellulose 
(cross-linked) 
hydrate 
9 CMC N-methylol- 
25 0.60 
2,020 
91.2 
-- 86.7 
90.2 
25.9 0.88 0.79 
acrylamide (un- 
cross-linked) 
10 CMC bis-acrylamido- 
25 0.21 
381 90.9 
800 
23.6 
23.9 
14.9 0.66 0.60 
acetic acid 
(cross-linked) 
11 CMC vinylsulfon- 
25 0.42 
17,040 
52.4 
1,230 
79.5 
78.0 
23.3 0.87 0.68 
amide (un- 
cross-linked) 
12 CMC*) 
bis-acrylamido- 
25 0.74 
7,640 
76.4 
800 
59.3 
61.7 
26.2 1.19 1.14 
acetic acid 
(cross-linked) 
13 CMC**) 
bis-acrylamido- 
25 0.74 
7,640 
76.4 
800 
56.4 
59.2 
20.9 1.13 1.05 
acetic acid 
(cross-linked) 
14 CMC*) 
bis-acrylamido- 
25 1.02 
542 83.8 
1,130 
49.9 
51.8 
26.8 1.25 1.19 
acetic acid 
(cross-linked) 
15 CMC**) 
bis-acrylamido- 
25 1.02 
542 83.8 
1,130 
51.9 
55.3 
24.9 1.24 1.14 
16 CMC*) 
bis-acrylamido- 
25 0.74 
7,640 
76.4 
800 
51.9 
54.5 
19.3 1.05 0.96 
acetic acid 
(cross-linked) 
17 CMC**) 
bis-acrylamido- 
25 0.74 
7,640 
76.4 
800 
51.9 
54.5 
17.7 1.08 0.94 
acetic acid 
(cross-linked) 
18 CMC*) 
bis-acrylamido- 
25 1.02 
542 83.8 
1,130 
46.6 
51.1 
17.2 bis-acrylamido- 
0.95 
acetic acid 
(cross-linked) -19 
CMC**) 
bis-acrylamido- 
25 1.02 
542 
83.8 
1,130 
47.7 51.1 17.7 1.10 1.08 
acetic acid 
(cross-linked) 
20 CMC*) 
bis-acrylamido- 
25 0.74 
7,640 
76.4 
800 
55.0 
56.3 
18.6 1.07 0.99 
acetic acid 
(cross-linked) 
21 CMC**) 
bis-acrylamido- 
25 0.74 
7,640 
76.4 
800 
53.1 
55.0 
18.8 0.99 0.89 
acetic acid 
(cross-linked) 
22 CMC*) 
bis-acrylamido- 
25 1.02 
542 83.8 
1,130 
45.6 
47.7 
18.2 1.01 0.99 
acetic acid 
(cross-linked) 
23 CMC**) 
bis-acrylamido- 
25 1.02 
542 83.8 
1,130 
47.2 
49.2 
19.6 1.02 0.94 
acetic acid 
(cross-linked) 
__________________________________________________________________________ 
*) The swellable, modified polymer is employed after sieving to a 
fineness of .ltoreq. 125.mu.. 
**) The swellable, modified polymer is employed after sieving to a 
fineness of .ltoreq. 200.mu.. 
TABLE III 
__________________________________________________________________________ 
Flexural 
Swellable, modified polymer WA in % 
Tensile 
strength 
Exam- Quantity 1 2 strength 
as the number 
ple Type 
Modifier 
% DS WRV WUA SV day 
days 
.sigma. B 
of folds 
__________________________________________________________________________ 
24 CMS 
bis-acrylamido- 
10 -- 2,700 
92.2 
1,600 
4.0 
4.1 
3.8 good at 
acetic acid 150,000 
(cross-linked) 
25 CMS 
bis-acrylamido- 
20 -- 2,700 
92.2 
1,600 
7.3 
7.5 
2.6 cracks at 
acetic acid 105,000 
(cross-linked) 
26 CMS 
bis-acrylamido- 
30 -- 2,700 
92.2 
1,600 
22.6 
22.5 
2.8 cracks at 
acetic acid 120,000 
(cross-linked) 
27 CMS 
bis-acrylamido- 
40 -- 2,700 
92.2 
1,600 
39.6 
39.7 
0.8 cracks at 
110,000 
(cross-linked) 
PVC -- -- -- -- -- -- -- 0 0 4.6 good at 
plast- 150,000 
isol 
with- 
out an 
addi- 
tion 
28 CMS 
bis-acrylamido- 
10 -- 2,700 
92.2 
1,600 
4.7 
4.9 
3.8 cracks at 
acetic acid 105,000 
(cross-linked) 
PVC -- -- -- -- -- -- -- 0 0 4.9 good at 
powder 150,000 
with- 
out an 
addi- 
tion 
__________________________________________________________________________ 
TABLE IV 
__________________________________________________________________________ 
Swellable, modified polymer WDA (%) 
Quantity WDD.sub.PFI 
without 
with 
Example 
Type 
Modifier 
% DS WRV WUA SV mg/cm.sup.2. 1 hour 
cover 
cover 
__________________________________________________________________________ 
29 CMC bis-acrylamido- 
10 1.02 
542 83.8 
1,130 
3.4 1.83 2.81 
acetic acid 
(cross-linked) 
30 CMC bis-acrylamido- 
20 1.02 
542 83.8 
1,130 
5.1 4.52 16.90 
acetic acid 
(cross-linked) 
31 CMC bis-acrylamido- 
20 1.02 
542 83.8 
1,130 
0.6 -- -- 
acetic acid 
(cross-linked) 
Leather 
-- -- -- -- -- -- -- 0.75 -- -- 
-3.0 
Leather 
-- -- -- -- -- -- -- 3.0 -- -- 
with a 
finish- 
ing 
layer 
Velour 
-- -- -- -- -- -- -- 15 -- -- 
leather 
__________________________________________________________________________ 
TABLE V 
__________________________________________________________________________ 
WDA Climatic 
WDD.sub.PFI 
Swellable, modified polymer (mg/cm.sup.2 
Conditions 
(mg/cm.sup.2 
(mg/cm.sup.2 
Quantity . 8 out- 
. 8 . 1 
Example 
Type 
Modifier 
% DS WRV WUA SV hours) 
inside 
side 
hours) 
hour) 
__________________________________________________________________________ 
33 CMC bis-acrylamido 
20 1.02 
542 83.8 
1,130 
12.49 
32.degree. C. 
20.degree. C. 
14.80 
1.85 
acetic acid 100% 
65% 
(cross-linked) r.h.* 
r.h. 
34 CMC bis-acrylamido 
20 1.02 
542 83.8 
1,130 
7.26 
32.degree. C. 
32.degree. C. 
6.71 0.84 
acetic acid 100% 
65% 
(cross-linked) r.h. 
r.h. 
35 CMC bis-acrylamido 
20 1.02 
542 83.8 
1,130 
2.75 
20.degree. C. 
20.degree. C. 
1.15 0.14 
acetic acid 100% 
65% 
(cross-linked) r.h. 
r.h. 
36 CMC bis-acrylamido 
20 1.02 
542 83.8 
1,130 
11.62 
32.degree. C. 
10.degree. C. 
14.41 
1.81 
acetic acid 100% 
65% 
(cross-linked) r.h. 
r.h. 
37 CMC bis-acrylamido 
10 1.02 
542 83.8 
1,130 
3.92 
32.degree. C. 
20.degree. C. 
2.28 0.29 
acetic acid 100% 
65% 
(cross-linked) r.h. 
r.h. 
38 CMC bis-acrylamido 
15 1.02 
542 83.8 
1,130 
5.69 
32.degree. C. 
20.degree. C. 
2.69 0.34 
acetic acid 100% 
65% 
(cross-linked) r.h. 
r.h. -39 
CMC bis-acrylamido 20 1. 
02 542 83.8 1,130 12 
.78 32.degree. 
C. 20.degree. 
C. 10.10 1.25 
acetic acid 100% 
65% 
(cross-linked) r.h. 
r.h. 
40 CMC bis-acrylamido 
25 1.02 
542 83.8 
1,130 
11.40 
32.degree. C. 
20.degree. C. 
22.48 
2.81 
acetic acid 100% 
65% 
(cross-linked) r.h. 
r.h. 
__________________________________________________________________________ 
*Relative humidity 
TABLE VI 
__________________________________________________________________________ 
Addition to the 
Compara- 
sheet-like Structure 
WDA WDD.sub.PFI 
tive Particle 
Quantity 
(mg/cm.sup.2 
(mg/cm.sup.2 
(mg/cm.sup.2 
Examples 
Type size (%) . 8 hours) 
. 8 hours 
. 1 hour) 
__________________________________________________________________________ 
V 1 cellulose 
.ltoreq. 125.mu. 
10 0.45 0.85 0.11 
powder 
V 2 cellulose 
.ltoreq. 50.mu. 
20 1.45 1.62 0.22 
powder 
V 3 cellulose 
50.mu.10 
0.34 1.16 0.15 
powder 
(92%) 
V 4 cellulose 
50.mu. 
20 0.96 1.15 0.14 
powder 
(92%) 
V 5 cellulose 
.ltoreq. 32.mu. 
10 0.34 4.38 0.55 
powder 
(96%) 
V 6 cellulose 
.ltoreq.32.mu. 
20 0.91 1.11 0.14 
powder 
(96%) 
V 7 maize .ltoreq. 100.mu. 
10 0.30 4.59 0.57 
starch 
V 8 maize " 20 0.44 2.52 0.31 
starch 
V 9 Dextran* 
20-80.mu. 
10 0.42 1.53 0.19 
three- 
dimension- 
ally cross- 
linked 
V 10 Dextran* 
" 20 1.42 1.65 0.18 
three- 
dimension- 
ally cross- 
linked 
__________________________________________________________________________ 
*Sephadex .RTM. G25, registered trademark of AB Pharmacia, Uppsala 
(Sweden) 
TABLE VII 
__________________________________________________________________________ 
Duration 
of the WDD.sub.PFI 
Swellable, modified polymer WDA measure- (mg/ 
Quantity (mg/ 
ments (mg/ 
cm.sup.2 . 
Example 
Type 
Modifier 
(%) DS WRV WUA SV cm.sup.2 
.rarw. (hours) .fwdarw. 
cm.sup.2) 
1 hour 
__________________________________________________________________________ 
41 CMC bis-acrylamido 
20 1.02 
542 83.8 
1,130 
11.20 
8 14.91 
1.86 
acetic acid 
(cross-linked) 
42 CMC bis-acrylamide 
20 1.02 
542 83.8 
1,130 
9.33 
6 9.00 
1.50 
acetic acid- (crosslinked) 
43 CMC bis-acrylamido 
20 1.02 
542 83.8 
1,130 
5.83 
4 5.79 
1.45 
acetic acid 
(cross-linked) 
44 CMC bis-acrylamido 
20 1.02 
542 83.8 
1,130 
6.67 
2 1.71 
0.86 
acetic acid 
(cross-linked) 
V 11.sup.1) 
-- -- -- -- -- -- -- 25.7 
8 27.5 
3.44 
V 12.sup.2) 
-- -- -- -- -- -- -- 18.8 
8 10.4 
1.30 
V 13.sup.3) 
-- -- -- -- -- -- -- -- 8 8-12 
1-1.5 
__________________________________________________________________________ 
.sup. 1) Aniline leather for shoe upper material 
.sup. 2) Unmodified polyurethane shoe upper material 
.sup. 3) Leather with a finishing coat for shoe upper material 
Table VIII 
__________________________________________________________________________ 
Addition to the sheet-like structure 
WDD.sub.DIN Climatic conditions 
(g/m.sup.2 . 24 
(g/m.sup.2 . 1 
Temperature 
Relative 
Example 
Type Quantity 
hours hour (.degree.C.) 
humidity (%) 
__________________________________________________________________________ 
V 14 -- -- 15.6 0.65 23 85 
45 CMC having DS = 1.02, 
10 17.4 0.73 23 85 
cross-linked with bis- 
acrylamido-acetic acid, 
WRV =0 542, WUA = 83.8, 
SV = 1,130, particle 
size .ltoreq. 125.mu. 
46 CMC having a DS = 1.02, 
20 44.2 1.84 23 85 
cross-linked with bis- 
arylamido-acetic acid, 
WRV = 542, WVA = 83.8, 
SV= 1.130, particle 
size = 125.mu. 
V 15 unmodified cellulose of a 
10 14.8 0.62 23 85 
particle size of 92% .ltoreq. 50.mu. 
V 16 20 13.0 0.54 23 85 
particle size of 92% .ltoreq. 50 .mu. 
V 17 unmodified cellulose of a 
20 26.3 1.09 32 85 
particle size of 92% .ltoreq. 50.mu. 
V 18 unmodified cellulose of a 
20 15.3 0.64 23 85 
particle size of 96% .ltoreq. 32.mu. 
V 19 unmodified cellulose of a 
20 26.4 1.09 32 85 
Particle size of 96% .ltoreq. 32 .mu. 
V 20 unmodified maize starch of 
10 14.9 0.62 23 85 
a particle size of .ltoreq. 100.mu. 
V 21 20 18.1 0.75 23 85 
particle size of .ltoreq. 100.mu. 
V 22 unmodified maize starch of 
20 36.1 1.50 32 85 
a particle size of .ltoreq. 100.mu. 
__________________________________________________________________________ 
TABLE IX 
__________________________________________________________________________ 
WDD.sub.PFI 
WDA 
Swellable, modified polymer (mg/cm.sup.2 
(mg/cm.sup.2 
(mg/cm.sup.2 
Exam- Quantity . 8 . 1 . 8 
ple Type Modifier (%) DS WRV WUA SV hours) 
hour) 
hours) 
__________________________________________________________________________ 
47 CMC epichlorohydrin 
15 0.75 
4,400 73.8 
1,500 
11.73 
1.47 13.24 
(cross-linked) 
48 polyacryl- 
cross-linked 
15 -- 117,000 50.0 
3,500 
23.18 
2.88 -- 
amide 
(Separan.RTM. )* 
49 acrylic 
tetraallyl- 
15 -- 20,300 33.4 
1,150 
4.02 0.50 1.83 
acid oxyethane 
(Viscaron.RTM. 
(cross-linked) 
** 
50 cellulose 
-- 10 -- 4,650 86.0 
1,320 
20.09 
2.52 -- 
phosphate 
51 CMC - highly 
thermally 
15 -- 9,000 41.0 
-- 3.35 0.42 5.21 
etherified 
cross-linked 
52 CMC - highly 
thermally 
15 -- 3,000 81.0 
-- 6.02 0.75 3.94 
etherified 
cross-linked 
53 CMC thermally cross- 
10 -- 1,900 89.0 
1,080 
6.48 0.81 2.22 
linked under acid 
conditions 
54 CMC thermally cross- 
10 -- 820 81.0 
1,050 
11.10 
1.39 2.33 
linked under acid 
conditions 
55 CMC bis-acrylamido- 
15 1.02 
542 83.8 
1,130 
-- 2.05 6.0 
acetic acid 
(cross-linked) 
__________________________________________________________________________ 
*Registered trademark of DOW CHEMICAL (USA) 
**Registered trademark of Protex (France) 
It will be obvious to those skilled in the art that many modifications may 
be made within the scope of the present invention without departing from 
the spirit thereof, and the invention includes all such modifications.