Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
Mo-1452-H
LeA 15,196
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POLYURETHANE ADHESIVE AND A METHOD
FOR HEAT SEALING TEXTILES
This invention relates generally to textiles and
more particularly to a process for heat sealing textile
sheets or sheet-like structures with polyurethanes or poly-
urethane ureas.
It is known that thermoplastic synthetic resins
may be used to heat seal textile sheets. The thermoplasts
may be applied to the textile surface as solids, e.g in the
form of powders (with certain particle sizes), fibers, woven
fabrics or non-woven webs. Alternatively, the thermoplasts
may be applied as viscous aqueous suspensions or dispersions.
The thermoplasts may also be dissolved in suitable solvents
to form viscous pastes which are applied to the textile
surface and then heated to dryness before the textile is sealed
by further heating. A further layer of fabric may be applied
to a surface which has been prepared in this way.
In the field of heat sealing textile sheets it is
advantageous to utilize heat sealing compounds which develop
the strongest possible bond and can still be ironed, at a
low temperature and pressure, within a short time. There is,
therefore, a commercial demand for products which can be
sealed at temperatures below 150C in less than 10 seconds.
In the past, heat sealing adhesives prepared from
polyethylene, polyvinyl chloride, polyamides or polyvinyl
acetate-polyethylene copolymers have been preferred. The
adhesives have melting points of from 100 to 120C and their
- melt viscosity may be adjusted to provide sufficient
elasticity and adhesive power, even at ironing temperatures
above 120C, enabling ironing of the treated textile to be
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carried out over a wide range of temperatures using a short
operating cycle.
The main disadvantage of these heat sealing
adhesives lies in their low resistance to detergents and dry
cleaning solvents. Polyurethanes, however, are much more
resistant to detergents and dry cleaning solvents and there
have, therefore, been attempts to utilize polyurethanes in
place of the well-known heat sealing adhesives. The poly-
urethane heat sealing adhesives used in the past have all
suffered from unsatisfactory melting properties. Thus, for
example, the heat sealable polyurethanes described in German
Offenlegungsschriften Nos. 1,915,803, 1,930,340 and 1,769,482
are not suitable as quick-setting heat sealing adhesives
because, their melting points being above 120C, they muqt be
ironed at temperatures of above 150C, at a pressure of from
0.5 to 0.7 kg/cm2 for a period of more than 10 seconds.
In the past, several attempts have been made to
overcome this difficulty, e.g by adding plasticizers to the heat
sealing compounds or by incorporating other additives to
lower the softening and glueing point of the polyurethanes.
All of these substances share the same disadvantage, namely,
~ that they are removed by normal dry cleaning and washing
; procedures; furthermore, once removed, they contaminate the
washing liquor or cleaning bath. In addition, these known
substances may sometimes have a noxious odor and be liable to
` migrate. For example, when interlinings are used, these
substances are liable to have a deleterious effect on the
cohesion of the synthetic resin used for bonding the fleece.
Migration of these substances may also spoil the appearance
of the textile on the side remote from the layer of adhesive,
in other words, the outside of the article, which is exposed
, -
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to view. 1037~
The use of soft linear polyurethanes, having low
softening point and heat sealing temperatures, for heat
sealing textiles has been described in DOS No. 1j619,019.
Although these heat sealing compounds melt at from 100C to
120C, their melt viscosities being too low and their poor
flow properties, when melted render them unsuitable. The
heat sealing compounds described in DOS No. 1,619,019 melt
within a narrow temperature range and, due to their low melt
viscosity, they rapidly migrate into the textile substrate.
The textile is thereby hardened. The bonding strength thus
obtained is only moderate, and in many cases it is found to
be insufficient. Because of these poor flow properties, the
products are difficult to handle, e.g. even slight deviations
from the correct sintering and ironing temperatures will
impair the bond strength of the sealed textile sheet.
It is therefore an object of this invention to
provide an adhesive for heat sealing textile sheets together
which is devoid of the foregoing disadvantages. Another
object of the invention is to provide a polyurethane adapted
to be used as a heat sealing adhesive for textile sheets.
Another object of the invention is to provide a polyurethane
or polyurethaneurea adhesive having a melting point below
150C. which is resistant to dry cleaning solvents and
detergents. Still another object of the invention is to
provide a process for heat sealing textile sheets together.
The foregoing objects and others are accomplished in
accordance with this invention, generally speaking, by
providing a process for heat sealing textile sheets wherein
at least one surface of a textile sheet is treated with a
**DOS stands for German Offenlegungsschrift.
LeA 15,196-Ca _3_
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solvent-free polyurethane and/or polyurethane urea which has
been prepared from
a) about 55 to about 95% by weight, based on the
whole polyurethane mass, of at least one com-
pound which contains at least two aliphatic
hydroxyl groups and has a molecular weight of
from about 1000 to about 2500 and a melting
point of from about 25 to about 130C,
b) at least one organic polyisocyanate, prefer-
ably present in about 5 to about 45% by weight,
and
c) 0 to about 15% by weight, based on the whole
polyurethane mass, of at least one aliphatic
polyol and/or polyamine, using an equivalent
ratio of a+c = 0 9 to 1.05
wherein said solvent-free polyurethane and/or polyurethane
urea has a melting range within the range of 100 to 120C
and a melt index, according to ASTM 1238 - 62 T, of 10 + 5
under condition B, 30 + 10 under condition C and 150 + 50
under condition E.
The present invention further relates to a solvent-
free polyurethane adhesive prepared from
a) about 55 to about 95% by weight, based on the
whole polyurethane mass, of a compound which
contains at least two aliphatic hydroxyl groups
and has a molecular weight of between about
1000 and about 2500 and a melting point between
about 25 and about 130C,
b) an organic polyisocyanate, preferably present
in about 5 to about 45% by weight, and
_.~ LeA 15,196-Ca ~ -4-
~037191
c) 0 to about 15% by weight, based on the whole
polyurethane mass, of an aliphatic polyol
and/or a polyamine at an equivalent ratio abc
of between about 0.9 and about 1.05
S wherein said polyurethane adhesive has a melting range of
from about 100C to about 120C and a melt index according
to ASTM 1238-62T condition B of 10 ~ 5, condition C of 30 + 10
and condition E of 150 + 50.
Polymers of this kind can be prepared by reacting
10 high molecular weight compounds, having a molecular weight
of 1000 to 2500 and a melting point of from 25 to 130C,
which preferably contain two, but optionally more, aliphatic
hydroxyl groups, with polyisocyanates, and optionally aliphatic
polyols and/or polyamines which have a molecular weight of up
15 to 400. The quantity of the high molecular weight polyhydroxyl
compound used is from 55% to 95% by weight, preferably from
75% to 90% by weight, based on the polyaddition product; the
quantity of the lower molecular weight chain lengthening
agent
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103ql9~
used is from 0 to 15% by weight and the ratio of NCO/(OH+NH2)
is from 0.9 to 1.05, preferably from 0.95 to 0.99.
The high molecular weight polyhydroxyl compounds (a)
used for the preparation of the polyurethanes or polyurethane
ureas may be prepared by polycondensation or polymerization.
Suitable high molecular weight polyhydroxyl compounds for
this purpose are, for example, the known polyesters, poly-
acetals, polyethers, polyamides, polyester amides, polycar-
bonates and polylactones and are described for example, in the
boo~ entitled "Polyurethanes: Chemistry and Technology" by
Saunders and Frisch published by Interscience Publishers.
The polycondensates which may be prepared from
polybasic, preferably dibasic, saturated and/or unsaturated
carboxylic acids and polyvalent, preferably divalent,
saturated and/or unsaturated alcohols, aminoalcohols, diamines,
polyamines and mixtures thereof, are to be included in the
scope of the terms polyester, polyester amide and polyamide
; ~ as used herein. Suitable polyacetals are, for example,
the compounds which can be prepared from hexane-1,6-diol and
i 20 formaIdehyde.
Any suitable polyether may be used in the process of
the present invention, including the polymerization products
of alkylene oxides such as, ethylene oxide, propylene oxide,
tetrahydrofuran and butylene oxide, as well as their copoly-
merization or graft polymerization products, and also the
polyethers which can be obtained by condensation of polyvalent
alcohols, amines, polyamines and amino alcohols
Any suitable polylactone may be used, including
.1
the polyesters which can be prepared by polymerizing lactones,
in particular ~-caprolactone.
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Any suitable polycarbonate may be used including
those prepared, for example, by a process of ester interchange
from glycols and polyols, such as hexanediol or trimethylol-
propane, and diphenylcarbonate.
Any suitable polyol which contains aliphatic hydroxyl
groups and has a molecular weight of up to about 400 may be
used such as, for example, ethylene glycol, propylene-1,3-
glycol, butane-1,4-diol, pentane-1,5-diol, hexane-1,6-diol,
methy~hexane-1,6-diol, trimethyl-hexanediol, neopentyl glycol,
1,4-bis-hydroxymethyl-cyclohexane, diethylene glycol, thio-
diglycol, methyldiethanolamine, xylylene glycol, hexane-1,2,6-
triol and also the ethoxylation products of divalent phenols
and glycols, e.g. bis-hydroxyethyl-hydroquinone and hydroxy-
ethyl-hexane-1,6-diol and the like may be used.
Any suitable aliphatic polyamine which has a molecular
weight of up to about 400 may be used, such as, for example,
ethylene diamine, diethylenetriamine, 1,2-diaminopropane,
1,4-diaminobutane, 1,3-diaminobutane, hexamethylenediamine,
N,N'-diethyl-1,3-propanediamine, N,N'-dibutyl-1,6-hexanediamine,
; 20 diamino-cyclohexane, hydrazine, 4,4'-diamino-dicyclohexyl-
methane, l-amino-3,3,5-trimethyl-5-aminomethyl-cyclohexane or
the like may be used.
"
The polyols and polyamines with a molecular weight
of up to 400 may be used in a quantity of from 0 to about 15%
by weight, based on the whole polyurethane or polyurethane
` urea mass.
The starting materials used for preparing the
polyurethanes and polyurethane ureas which are to be used
according to the process of the present invention also include
aliphatic, cycloaliphatic, araliphatic, aromatic or hetero-
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cyclic polyisocyanates. The equivalent ratio of polyisocyanates
to the other components used is from 0.9 to 1,05, preferably
from O.9S to 0.99.
Aliphatic polyisocyanates including cycloaliphatic
S polyisocyanates are particularly preferred, for example,
butane-1,4-diisocyanate, hexane-1,6-diisocyanate, 2,2,4-tri-
methyl-hexane-1,6-diisocyanate, xylylene diisocyanate, methyl
cyclohexane diisocyanate, cyclohexane diisocyanate and
diisocyanatocarboxylic acid esters (such as those described
e.g. in U.K. Patent Nos. 1,072,956 and 965,474), l-isocyanato-
3,3,S-trimethyl-S-isocyanatomethyl cyclohexane and biuret
triisocyanates. Biuret triisocyanates may be prepared by a
reaction between aliphatic diisocyanates and water accompanied
by the formation of urea and biuret groups; for example,
the biuret triisocyanate
OCN-(CH2)6-NH-CO-N-(CH2)6-NCO
CO
NH
(CH2)6
NC0
which can be prepared from hexane-1,6-diisocyanate. Also
addition products obtained by reacting aliphatic diisocyanates
with polyols, which contain at least 3 hydroxyl groups, and
reaction products which are obtained by an addition reaction
of acrylonitrile with polyols followed by hydrogenation and
phosgenation may be used.
. .
In addition to the starting materials mentioned
above, minor quantities of compounds such as those described
in e.g. U. S. Patent 3,756,992 may also be included. These
compounds modify the polyurethanes cationically or anionically
without greatly affecting the properties which are desirable
in this instance.
~eA 15,196 _7_
`~10371~1
Compounds of this kind include chain lengthening
.~cnt~ which contain basic nitrog~n atoms, e.g. N-methyl-
dicth~nolamine, N- ~-hydroxyethylpiperazine or 2,6-diamino-
pyridine; cllain lengthening agents which contain halogen atoms
cap~blc of quaternization e.g. glycerol-~-chlorohydrin, or
R-SO2o ~roups, e.g. glycerol monotosylate; and compounds
which contain at least one hydrogen atom capable of reacting
with isocyanate groups and at least one salt-type group capable
of anionic salt formation e~g. lactic acid, uric acid,
glycine, arignine, thiodiglycollic acid, nitrolotriacetic
acid, 2-hydroxyethane sulphonic acid, hydroxylamine mono-
sulphonic acid, bis-propylene glycol ester of phosphoric acid,
hydrazine dicarboxylic acids, or polyesters which contain
carboxyl groups.
lS The compounds which are suitable for ionic modifica-
tion are mixed with the other components either before or
during the formation of the polyurethane or polyurethane urea.
A process in which prepolymers of the polyisocyanates and poly-
hydroxyl compounds, so-called NCO prepolymers, are cationically
or anionically modified by reacting them with the above-
' mentioned compounds, is particularly preferred.
Preparation of the polyurethanes and polyurethane
ureas which are to be used as heat sealing adhesives according
to the process of the present invention, may be carried out
` 25 by heating the solvent-free starting components to 40 to 200C,
I but the components may also be reacted in solution, using
j solvents which are inert towards the polyisocyanates, polyols,
polyamines, and high molecular weight polyhydroxyl compounds,
for example, acetone, tetrahydrofuran, dioxane, methyl ethyl
ketone, benzene, toluene, xylene, methyl acetate, butyl
acetate, chloroform, carbon tetrachloride, tetrachloroethylene,
LeA 15,196 -8-
trichloroethane, chlorobenzene, formamide, dimethylformamide,
aimethylacetamide and dimethylsulphoxide. Preparation of the
polyurethanes and polyurethane ureas may be carried out, for
example, by dissolving the reactants in the chosen solvent.
The reaction is carried out by conventional methods at
temperatures of from 40 to 200C, optionally under pressure
(e.g. 1 to 10 atmospheres) and with the addition of catalysts
such as tertiary amines or organometallic compounds. If the
reaction product is insoluble in the solvent used, it may be
isolated by suction filtration and subsequently dried. If,
on the other hand, the polyurethane remains partly or completely
in solution it may be isolated either by distilling off the
solvent or by precipitating it by the addition of water or
other solvents, in which the product is insoluble, which are
readily, or at least partly, miscible with the reaction
solvent, traces of the solvent are then removed by drying,
optionally under vacuum and optionally at an elevated tem-
perature.
If desired, however, the high molecular weight poly-
hydroxyl compound, with a molecular weight of 1000 to 2500
and a melting point of above 25C may first be reacted with
the aliphatic polyisocyanates and the reaction may then be
completed by adding the polyols or polyamines, which have a
lecular weight of up to about 400, either with or without
a solvent present.
If desired, the polyurethane or polyurethane urea
may be isolated from a solution by a process of spray
` drying in which the solutions are atomized under pressure
through nozzles into a drying chamber at elevated temperature.
The crude product may also be granulated or broken
down by grinding in a mill. The particles of the required
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size for use in conventional application machines are isolated
by fractional sieving.
The average particle size of the powders generally
varies between 0.01 and 0.5 mm according to the purpose for
which the heat sealing compounds are required and the form in
which they are to be used, for example, particles of between
0.001 and 0.08 mm are used for viscous pastes, particles of
O.08 to 0.2 mm for the powder point process and particles of
O.2-0.5 mm for the powder scattering process.
The fact that the polyurethanes and polyurethane
ureas, which are to be used according to the process of the
present invention, can be used in the form of fibers, woven
fabrics or non-woven webs enables them to be distributed
uniformly as required, without any waste and without using
any special apparatus for dist,ributing the sealing compound.
Waste of the sealing material such as may occasionally occur,
e.g. when the material is sprayed in the form of a powder,
is thus avoided.
The bonding strength and other properties which can
be achieved, according to the present invention, allow for
wide and varied use of the heat sealing compounds for heat
sealing woven and knitted fabrics, felts and non-woven
webs of natural and synthetic fibers, particularly cotton,
rayon, wool, horse hair and polyacrylonitrile, polyamide and
polyester fibers.
The bond in the textile material is resistant to
washing and dry cleaning.
Heat sealing is carried out by applying the poly-
urethanes and polyurethane ureas in the form of powders or
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threads, woven or non-woven webs or pastes to the textile
surface and then sintering them by means of a source of heat.
The amount of heat required depends on the structure of the
lining material which is to be treated, the quantity applied
and the application technique.
Powder with a particle size of 0.2 to 0.5 mm is
applied by uniformly spraying or scattering a sufficient
quantity of it over the surface of the substrate such as a
woven or non-woven fabric, for example, in a quantity of
from about 6 to about 30 g/m . The substrate, covered with
powder, is then exposed to an infrared radiant heater for
about 10 to 20 seconds. By the action of heat the substance
becomes permanently bonded to the surface of the substrate.
The material is then removed from the heating zone, cooled
and, at a later date, joined to another web of material, for
example, a cotton poplin or woolen top cloth, to form a
composite material. This is carried out by placing the treated
substrate and the above-mentioned second layer of material
together in such a way that the heat sealing adhesive forms
the middle layer between them. The materials are then bonded
together by subjecting them to a sudden application of heat
for approximately 10 seconds at a pressure of 0.3 to 0.4 kg/cm2,
e.g. in an electric ironing press at a temperature o~ 145C.
During this short period of time, the adhesive becomes plastic
and permanently bonds the substrate to the second layer.
The composite material is then removed from the ironing press
and is immediately ready for use when cool.
Powders with a particle size of from 0.08 to 0.2 mm
are applied by processes known in the industry as powder
point processes. The amount applied may vary from 15 to
30 g/m according to the substrate and is preferably
LeA 15,196
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approximately 20 g/m2. The substrate is then sealed to the
top cloth in an electrically heated ironing press under the
conditions mentioned above.
Heat sealing with the polyurethanes or polyurethane
ureas in the form of paste is generally carried out as
follows: by mixing 1 part by weight of a powder which has a
particle size of 0.001 to 0.08 mm with 1 part by weight of
water, which contains a thickener, for example, one based on
polymethacrylate; stirring the mixture, adjusting the pH to
7.5 with ammonia; then uniformly imprinting the paste on the
substrate, preferably pointwise, using a stencil or sieve drum
and applying a quantity of from 10 to 30 g/m2, preferably
approximately 20 g/m2. The substrate, for example, a woven
fabric or non-woven web, to which the paste has been applied,
is then dried in a drying chamber at temperatures of up to
160C. The polyurethane particles are thereby so firmly
bonded to the support material that the textile webs can
easily be rolled up. Another textile, e.g. a woven or
knitted fabric or non-woven web, may then be applied to that
side of the support on which the synthetic resin has been
printed and the two layers are then bonded together by sudden
application of heat under pressure, for example, in an
electric ironing press as described above. The composite
material is then removed from the press and can be used as
soon as it has cooled. The laminates produced in this way
have a pleasant, soft handle due to the uniform distribution
of the bonding agent.
Fibers or sheets may also be produced in a similar
manner by the application of polyurethanes and polyurethane
ureas according to the process of the present invention.
When used in this way fibers are drawn from the melt in known
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manner, e.g, at temperatures of from 100 to 200C in the
absence of air, and are then stretched and cut up into staple
fibers. These fibers can be made up into non-woven webs or
spun to form threads and then made up into woven or knitted
fabrics or layers of random threads in known manner.
Alternatively, filaments, which have been drawn from the melt
and stretched, can be directly deposited as spinning fleeces
in ~nown manner. When used for heat sealing textiles, these
sheets are applied to the substrate and then either sintered,
if they are subsequently to be bonded in ironing presses, or
directly bonded to a second material by sudden application
of heat and pressure, e.g. a woven or knitted fabric or
non-woven web made of a material which is not thermoplastic
at the operating temperatures employed. ~oth ironing
presses and calendars are suitable for this purpose. This
process again results in soft composite materials which are
distinguished by their high resistance to water and solvents.
! Examples
I
Polyurethane A)
Formulation: 86.3 parts by weight of a polyester from adipic
acid and butane-1,4-diol, OH number
50 (molecular weight 2240),
2.6 parts by weight of butane-1,4-diol and
11.1 parts by weight of hexane-1,6-diisocyanate
a) Preparation in solution
A polyester from adipic acid and butane-1,4-diol,
which has been dried in vacuo at 120C for 30 minutes, is
dissolved in tetrachloroethylene. Hexane-1,6-diisocyanate is
added at a temperature of 100C, followed by butane-1,4-diol.
The components are heated under reflux for 5 hours.
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When the reacted mixture of polyurethane and
solvent is cooled with vigorous stirring by a high speed
laboratory stirrer, the polyurethane is obtained as a moist
powder. After removal of the solvent, the reaction product
is dried and sieved to remove coarse particles. Melting
point: 110-112C,
Melt index according to ASTM 1238 - 62 T Condition B: 12.0
Melt index according to ASTM 1238 - 62 T Condition C: 33.6
Melt index according to ASTM 1238 - 62 T Condition E: 168
b) Preparation in the melt
Hexane-1,6-diisocyanate and butane-1,4-diol are added,
with stirring, at 100C, to a polyester which has been dried
in vacuo at 120C for 30 minutes. The reaction mixture is
kept at 100C for 20 hours. When the resulting polyurethane
has cooled, it is ground up and sieved. Melting range:
110-114C.
Melt index according to ASTM 1238 - 62 T Condition B: 7.3
Melt index according to ASTM 1238 - 62 T Condition C: 49.2
Melt index according to ASTM 1238 - 62 T Condition E: 182
Polyurethane urea B
Formulation: 85.0 parts by weight of a hexanediol polycarbo-
nate with molecular weight 1870
13.5 parts by weight of hexamethylene diiso-
cyanate
0.75 parts by weight of N-methyl-diethanolamine
0.75 parts by weight of dimethylsulphate and
100 parts by weight of acetone.
The polycarbonate is dried in vacuo at 120C for
30 minutes,and hexamethylene diisocyanate is added at 105C.
~eA 15,196 -14-
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The mixture is kept at 100C for one hour and N-methyl-di-
ethanolamine in 1/11 of the total quantity of acetone is
added after the mixture has been cooled to 60C. The resulting
mixture is then kept at 60C for 3 hours and a further 2/11
of the acetone are added~ The product is then quaternized with
a solution of dimethylsulphate in the remaining quantity of
acetone (8/11). A 50% acetonic NCO prepolymer solution which
is slightly cationically modifed is obtained. It has an NCO
content of 1.20~ and a viscosity of n25 = 179 cP.
When this prepolymer solution and equal parts of water
containing, in solution, 85~ of the theoretical quantity of
propylene-1,2-diamine, based on the NCO content of the pre-
polymer, are mixed with vigorous stirring, for example, by
a rapidly rotating laboratory stirrer, a suspension which
lS has a tendency to sediment is obtained. The aqueous acetone
~, i8 decanted off and the powder obtained is dried. Melting
point: 104-108C.
Melt index according to ASTM 1238 - 62 T Condition B: 5.4
Melt index according to ASTM 1238 - 62 T Condition C: 34.7
Melt index according to ASTM 1238 - 62 T Condition E: 197.3
Example 1
The polyurethane powder A prepared in solution
i according to method (a) is fractionated by sieving. The
fraction isolated within the sieve limits of 0.2 to 0.3 mm
is uniformly sprinkled over an undyed cotton twill fabric
weighing 200 g/m2, the amount applied being 25 g/m2. It is
then exposed for 20 seconds to a 1500 watt infrared radiant
heater which has a surface area of 300 cm2, the heater being
held at a distance of 20 cm. The powder is thereby softened
; 30 and adheres to the fabric. When cool, it is firmly bonded
~eA 15,196 -15-
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to the fabric. A cotton tricot fabric is then placed on the
surface to which the powder has been applied, and the two
fabrics are pressed together under an ironing press (manu-
factured by Ducker) at a temperature of 170C and pressure
of 400 g/cm2 for 10 seconds. The resistances to separation of
the resulting laminate after it has been cooled and aired are
as follows:
Without treatment 0.7-1.0 kg/2.5 cm
After machine washing (60C) 0.6-0.8 kg/2.5 cm
After dry cleaning (in
perchloroethylene) 0.5-0.7 kg/2.5 cm.
Example 2
Polyurethane A obtained from the melt by method (b)
is ground and sieved. The fraction of particles measuring
0.08 to 0.2 mm i8 isolated and applied to an interlining fabric
weighing 180 g/m2 by means of an 11 mesh applicator roller in
a powder point machine (made by Saladin of Sirnach/Switzerland).
After passing through a cooling zone, the fabric is rolled up.
After this fabric, to which 20 g/m2 of powder has been
applied by point application, has been sealed it is bonded to
a second fabric (wool top cloth) by pressing the two fabrics
under an ironing press as described iD Example 1 at a
temperature of 170 and pressure of 400 g/m2 for 15 seconds.
The resulting composite material has the following resis-
tances to separation after cooling and airing.
Without treatment 0.8-1.1 kgj2.5 cm
After machine washing (60C) 0.7-0.9 kg/2,5 cm
After dry cleaning (in
perchloroethylene) 0.6-0.8 kg/2.5 cm
Comparison Example 3
The polyurethane urea B (Powder I) described above
and a polyurethane (Powder II) prepared according to Example 1
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of DOS No. **1,930,340 (U. S. Patent No. 3,684,639), which con-
sist of particles smaller than 0.08 mm are each made up into an
aqueous paste and then uniformly applied pointwise to a cotton
fabric weighing 80 g/m2 by means of a screen printing stencil
and finally dried. The paste has the following constituents:
500 g of the polyurethane powder,
750 g of water,
40 g of glycerol
65 g of emulsifier (*)
2 g of silicone defoaming agent.
After drying, the pretreated cotton fabrics are
bonded to a cotton tricot layer by ironing using a laboratory
press (manufactured by Kannegiesser) under the conditions
indicated in the following table. The heating of the poly-
urethane was accomplished using a thermoelectric element.From the table, it is clear to one skilled in the art that
powder I has distinct sealing properties having been sub-
jected to temperatures of from 125C,a sealing time of 10
seconds and a pressure of 300 p/cm2 and can be sealed
sufficiently firmly by application of a pressure of 400 g/cm2
for 5 seconds. If a pressure of 400 g/cm2 is applied for
a longer time, then overfixing results. Powder II, on the
other hand, does not fix sufficiently under the given con-
ditions. To obtain a satisfactory bond by ironing, it is
necessary to apply a higher pressure at a higher temperature
for a longer sealing time, as can be seen from Example 1 of
; DOS **No. 1,930,340 (U. S. Patent No. 3,684,639).
(*) Reaction product of polyethylene oxide and stearylisocyanate,
** DOS stands for German Offenlegungsschrift.
LeA 15,196-Ca -17-
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TABLE
(Continuation)
Rolle~ Temperature 160C
Press~re Pressing T. Powder I) Powder II)
g/cm time C
seconds. _ . .
200 5 100 0.05 0
~ 10 . 115 0.15 0.1
; 15 120 0.15-0.2 0.15
300 5 100 0.05-0.15 0
. 10 120 0.4 -0,65 0.2-0.4
, 15 125 0.4 -0.7 0.2-0.4
400 5 110 0.5 -0.7 0.05-0.1
. 10 125 0.7 -1.0 0.25-0.4
.l 15 _ 135 0.8 -1.1 0.25-0.45
T. : = temperature in the gap (measured on the fabric)
Any of the other polyurethanes and polyurethane
ureas indicated as suitable herein can be substituted for those
of the foregoing examples.
Although the invention has been described in detail
for the purpose of illustration, it is to be understood that
such detail is solely for that purpose and that variations
can be made therein by those skilled in the art without
dèparting from the spirit and scope of the invention except
as it may be limited by the claims.
LeA 15,196 -19-
