Note: Descriptions are shown in the official language in which they were submitted.
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The invention relates to pressure sensitive contact adhesives and
manually-tearable contact adhesive tapes produced therefrom which
can be used in the embroidery and textile industries for the
purpose of fixing textiles to be embroidered onto operating
machines. In connection with the present invention, the term
contact adhesive tapes is to refer not only to tapes but also to
other areal products, for example sheets or leaves.
Embroiderers stitch motifs onto textiles by means of computer-
controlled embroidery machines ~hich are fitted with a different
number of embroidery heads according to type and size, each
emb~oidery head being e~uipped with several needles for
differently coloured yarns. The textile to be embroidered is
fi~ed on a fleece paper or another manually-tearable material.
The fixing ~upport is glued into a bordering frame which moves
according to ~he computer program in such a way that the needle
produces the desired embroidered motif with up to 700 stitches
per minute.
Suitable areal materials are fibre fleeces, particularly fleece
paper a~d long-fibred special papers, fibre fleeces are textile
webs made from textile fibres, the coherence of which is provided
by the~inherent adhesion of the fibres. Fibre fleeces which are
pxoduced by the strengthening of spun fibres ars called spun
fleece~.
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In general, one understands by a fleece a textile product in
which the fibres are evenly distributed. They may or may not be
orientated. In contrast to woven textile materials, the fibres
are processed not to yarns and to woven fabric, but laid together
by mixing and distributing. The binding together of the fibres
is carried out by mechanical, chemical and/or physical means.
The fleece products can be very different in their construction
ranging form unconnected to tightly bound, supple to stiff,
compact to highly voluminous. The weaker the fibre orientation,
the better the material can be cut, with the result that cutting
wastage only occurs to a very slight degree. Decisive for the
properties of the fibre fleeces by fibre type, fibre guage,
staple length and density of the fibres as well as the binding
agents used.
Used as fibres for fleeces are plant fibres based on cellulose,
animal wool fibres based on protein, semi-synthetic viscose and
acetate cellulose fibres and synthetic fibres based on
polyamides, polyacrylonitrile, polyvinyl derivatives, polyesters
and polyole~ins. The fleece papers based on cellulose therefore
also come under the generic term fibre fleece in the broader
sense, although they are often regarded as a special material
cla3s.
It is a prerequisite for the use of fibre fleeces, special papers
or other areal materials as fixing supports of textiles in
embroidery operations that the materials are compact and supple
so that they lie well against the material to be embroidered and
improve the plasticity of the embroidered motif. Further, they
must be able to be manually torn away easily without problem
outside the motif edges after the stiching.
In the past, embroiderers have sprayed ~leece materials with a
spray adhesive which consists o~ polyvinyl ester copolymers such
as for ex~mple polyacrylic acid copolymers and is dissolved i.n
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chlorofluorocarbons. Aerosols based on chlorofluorocarbons are
used as propellants for such spray adhesives. During the spraying
and drying of the adhesive, environmentally polluting gases form.
In addition to the undesired gas formation, the spray adhesives
display crucial disadvantages above all in use: It is so greasy
that adhesive residues adhere in the needle channel after a short
embroidery time and prevent a proper guiding of the thread. The
adherence of the material to be embroidered on the spray adhesive
fleece is often too weak. If the textile material moves during
the embroidery process, the embroidery sample develops faults and
becomes unusable. Furthermore, the spray adhesive lakes after a
short time and loses its adhesive properties.
It is also a disadvantage that the spray adhesive presoaks
traditional fleece papers, as it cannot be measured exactly, and
therefore leaves the support material unstable in the case of
extensive coating.
It was therefore necessary, in order to be able process woven and
machine goods in the field of embroidery, to coat the support
material fleece by means of a textile adhesive spray in order to
then fix the product to be embroidered. The term "fixing" is to
be understood as a stabilising of the stitches or woven fabric
of the material to be embroidered. On spraying larger areas,
uneven coatings occur through a manually-carried out activity
which
a) can lead to detachment of the product to be embroidered and
b) since no exact dosage is possible, causes spots to form in
the case of sensitive materials, ~chiffon, silk, ~ersey
etc.).
Furthermore, the fleece is presoaked if the spraying is too
strong, resulting in instability. In this case, the embroidered
product becomes deformed in its thread length and thereby
unclean.
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Further, with too strong a spraying the thread as well as the
thread channel of the needle is affected, which means that loop
formation is not clean or the thread sticks in the thread channel
of the needle with the result that, upon taking up o~ the loop
of the double rotary shuttle, there is no timing s~nchronization
and this leads to thread tears, lost stitches and therefore to
lost machine time.
An alternative was the use of thermofleece. Thermofleeces are
spun or stitched fleeces which are coated by means of a heat-
soluble adhesive.
Thermofleeces are used to fix the fibres for extremely
stretchable knitted products, these fleeces also having to be
removed at certain parts of a textile after embroidering. In the
tricot material field of use the handling of the above fleece is
to be considered very difficult since,
a) at too high a temperature a discoloration of the embroidery
material occurs and, furthermore, the fleece can be cleanly
removed only with difficulty, if at all without distorting
the embroidery image (a further unpleasant characteristic
are the residues (adhe~ive particles) on the embroidered
product) and
b) in order to be able to use thermofleece in the best
possible way, costly additional machine expenditure (fixing
press, through-run fixing units or irons) is required.
When irons are used, a regular bond does not result here either,
since the surface heating and cooling cannot be controlled
linearly. This results in an uncontrolled detachment o~ the
material in the case of a longer embroidery process. The use of
a thermofleece in the first run for a larger production range is
ruled out since the fixed material can only be stored on a flat
plane and is therefore very cost intensive.
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The question now arises of whether a fleece material fitted in
a self-adhesive manner is better suited to this application than
a spray adhesive fleece. Pressure sensitive self-adhesive
compositions or contact adhesives have been used everywhere for
some time in the form of contact adhesives in industry, craftwork
and homes. Known from the patent literature are numerous examples
for the production of rubber and polyacrylic acid ester contact
adhesives based on organic solvents and aqueous dispersions.
Described in DE-OS 36 43 987, DE-OS 38 43 421 and EP 0 141 504
are copolymers of acrylic acid esters, acrylic acid and other
monomers. Described in DE-OS 30 18 131 are contact adhesives
comprising polyacrylic acid esters and polyisocya~ates based on
solvents. Emulsion contact adhesive polymers of n-butyl acrylate,
2-ethyl hexyl acrylate, acrylic acid, acrylonitrile, vinyl
acetate, methyl methacrylate and other monomers are for example
described in patent specifications EP 0 130 080, EP 0 193 295,
EP ~ 258 753, DE 31 47 007, DE 33 13 922, DE 35 31 601, DE 38 29
077, DE 37 01 757 and DE 38 08 706.
In terms of their use for self-adhesive fleece materials in
textile embroidery, all the described contact adhesives based on
polyacrylic acid ester display shortcomings which prevent or
considerably limit their use possibilities. technical services
studies have ~hown that either the contact adhesives very quickly
block or stick the needle channel or adhere unsatisfactorily to
the f leece material so that, upon removal of the textile
materials, they wind around the latter. Other contact adhesives
are well anchored on f leece materials but leave behind adhesive
residues on the textiles. Nany contact adhesives partially
migrate into the f leece materials and into the textiles. On
ironing, washing or cleaning, sewn-in fleece pieces can spoil the
textile materials in the embroidery area through low-molecular
weight adhesive components with formation of spots.
It is the object of the invention to develop a pressure-sensitive
contact adhesive for fleece materials in embroidery ~hich does
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not display the disadvantages described above and which can be
used problem-free on fleece material as fixing adhesive for
textiles to be embroidered. Even at high embroidering speeds the
adhesive is not to block needle channels over a relatively long
period.
The ob~ect is achieved by a pressure-sensitive contact adhesive
which consists of a mixture of the following components and
optionally usual auxiliaries:
A) 0 to ~0 wt.%, particularly 0 to 86 wt.% acrylic acid ester-
vinyl acetate-acrylic acid copolymer with 2 to 8 carbon
atoms in the alcohol component of the acrylic acid ester
and, relative to the copolymer, 10 to 60 wt.%, particularly
15 to 55 wt.% vinyl acetate and 1 to 10 wt.%, ~articularly
2 to 8 wt.% acrylic acid (K value according to Fikentscher
in the range 50 to 110 (measured according to DIN 51562 in
tetrahydrofuran)),
B) 10 to 80 wt.%, particularly 10 to 75 wt.%, preferably 10 to
67 wt.~ and specifically 10 to 60 wt.% acrylic acid ester-
acrylic acid-N-methylol methacrylamide copolymer with 4 to
8 carbon atoms in the alcohol component of the acrylic acid
ester and, relative to the copolymer, 1 to 10 wt.%, parti-
cularly 2 to 8 wt~% acrylic acid and 1 to 10 wt.%, parti-
cularly 2 to 8 wt.% self-crosslinking N-methylol methacryl-
amide (K value according to Fikentscher in the range 70 to
130 (according to DIN 51562 in tetrahydrofuran)),
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C) O to 90 wt.%, particularly 0 to 85 wt.% acrylic acid ester-
ethyl acrylate - N-methylol-methacrylamide - acrylic acid
copolymer with 4 to 8 carbon atoms in the alcohol component
of the acrylic acid ester and, relative to the copolymer,
1 to 10 wt.~, particularly 2 to 8 wt.% acrylic acid and 1
, to 10 wt.%, particularly 2 to 8 wt.% self-crosslinking N-
mathylol methacrylamide and 20 to 80 wt.%, particularly 20
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to 60 wt.%, preferably 25 to 55 wt.% ethyl acrylate (K
value according to Fikentscher in the range 80 to 130
(measured according to DIN 51562 in tetrahydrofuran))~
D) 0 to 25 wt.%, particularly 0 to 20 wt.% phthalic acid ester
with 2 to 12 carbon atoms in the alcohol component of the
ester.
The amount of components A) and/or C) which are present in addi-
tion to Component B~ is preferably at least 0.1 wt.%, more pre-
fered at least 1.0 wt.% and specifically at least 5 wt.%. In case
component A) is present it is preferably present in an amount of
5 to 86 wt.%, more prefered 13 to 86 wt.% and specifically 10 to
50 wt.%. In case component C) is present it is preferably present
in an amount of 5 to 90 wt.%, more prefered 10 to 90 wt.% and
specifically 20 to 90 wt.~. In case component D~ is present it
is preferably present in an amount of 5 to 20 wt~ and more pre-
fered 10 to 20 w~.%.
The contact adhesive components are produced according to the
usual processes in the patent literature.
Component A preferably has a K value of 60 to 100, component B
a ~ value of 80 to 120 and component C a K value of 90 to 120.
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Small quantities of other monomers such as e.g. methacrylic acid
sster, methacrylic acid, methacrylonitrile and styrene can be
polymerized into the copolymers of the mixture components A) to
C). The monomers can be contained in quantities of 0.5 to 25,
more prefered 0.5 to 20 wt.~, particularly 1 to 15 wt.% in the
copolymers, based on the weight of the copolymers. The acrylic
acid ester components in-the copolymers are preferably n-butyl
acrylate and/or 2-ethyl hexyl acrylate.
The mixture according to the invention is preferably present as
~t an aqueous dispersion, the pH value of which is set at 7 to 8,
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preferably 7 to 7.5 with ammonia water. It is coated onto support
materials in quantities of 5 to 50 g/m2, particularly 10 to 45
g/m2, dried to a self-adhesive film and covered with an adhesive
separating material.
The aqueous copolymer dispersions contain the anionic emulsifiers
usual in the literature, such as are e.g. described in the book
"Methoden der organischen Chemie" by Houben-Weyl, Volume 14/1,
Makromolekulare Stoffe, Georg-Thieme-Verlag, Stuttgart 1972,
pages 192 to 208.
In order to achieve an even coating and a good film formation,
additives such as thickeners, wetting agents and foam inhibitors
are added in usual quantities (0.5 to 5.0 wt.%, particularly 0.1
to 2.0 wt.%) to the dispersion.
The invention further relates to the use of the pressure
sensitive contact adhesive according to the invention, which can
be used when cold, for the coating of support materials such as
fibre fleeces, fleece papers and long-fibred special papers in
the range 15 to 100 g/m2, preferably 20 to 40 g/m2.
A areal, thin and transparent separating material such as
siliconized paper or siliconized films are coated with the
aqueous dispersion. On drying the dispersion, a pressure-
sensitive contact adhesive film results with coating strengths
of 5 to 50 g/m2 and particularly 10 to 45 g/m2 which is coated
onto support materials. Particularly suitable as support material
are fibre fleeces and fleece papers based on cellulose.
The substrates coated in this way, which are manually tearable,
serve as fixing adhesive tapes in textile embroidery. Light
textiles such as e.~. light cotton, Jersey and silk and heavy
textiles such as e.g. working clothes made from heavy cotton or -
wool, terry towelling and jeans adhere well at slight pressure
on coated fleece papers.
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The textiles fixed on self-adhesive fleece paper were embroidered
at a speed of ca. 700 needle stitches per minute. After 10
minutes' stitching time, the needle eye and needle channel
remained free from adhesive residues. Slipping of the textiles
was not observed during the stitching process. The fleece paper
outside the embroidered motif edges was then able to be torn off
easily and free from any adhesive residues.
If the embroidered textile is sewn onto a textile material it is
usual not to remo~e the self-adhesive fleece paper on the
embroidered back of the textile, but to sew it in as a
plasticizing insert. Ironing, washing and cleaning operations
have shown that the contact adhesive and the fleece paper do not
impair the quality of the textile.
The newly developed material is to be categorized as a material
gentle to textiles and as a material simple to handle. Neither
gases nor fumes are released on its processing. Furthermore, it
is po~sible to fix it onto the embroidered material by slight
contact pressure (cold fixing) which is kind to knitted, stitched
i and woven-fabric materials. Since the material to be processed
can be coated, deformation of the basic material is avoided. The
use in border or individual stitch frames has the advantage that
the material to be embroidered no longer has to be clamped, but
is held by the film coated onto it.
Since the contact adhesive according to the invention neither
cloud~ nor softens, the whole mechanics and electronics of a
computer-controlled embroidering machine is spared. Since the
contact film formed can be so adjusted that neither the needle
nor the gripper are affected by adhesive, a considerably higher
utilization of the machines is possible. Furthermore, the
maintenance intervals are extended. The adhesive also does not
cause different types of yaxn to connect. The embroidery image
1 is improved li~ewise by the simultaneous adhesion.
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A strip measuring 3.20 m x 0.45 m is connected to the embroidery
frame using mechanical clamps in the case of a border frame. The
silicone paper is then removed and the product to be embroidered
is connected by contact pressure with the adhesive tape. A
stabilisation of the embroidered product results because of this,
so that the stitches can no longer be deformed. Since thermal
heat (ironing) is not used either, the fibre is no longer heated
unevenly or overheated prior to the embroidery process, meaning
that the material to be embroidered is spared. This process also
applies to the use of single ~rames which are used e.g. with
finished parts.
The bordering frame or single frame is moved by means of stepped
motors according to the prepared program (transport). The needle
maintains its position and performs an upwards and downwards
movement during the stitching process. It is important that the
embroidering machine's speed is determined according to the type
of stitch, length of stitch and position of the stitch. The
material produced according to the invention offers an immense
advantage here, a linear surface adherence.
The invention is explained in more detail in the following with
reference to examples.
E~AmDles 1 to 5
Given in Table 1 are various formulations for the contact
adhesive according to the invention in the form of aqueous
di~persions. The weight percentages of the formulations are
relat~d to 100 % ~olids, i.e. water proportions are not included.
The dispersions were coated on papers siliconized on one side (67
g/m2) such that, after drying, adhesive films wi~h ca. 10 g/m2
adhesive formed. The adhe ive coatings were coated on fleece
paper (Fa 30 g/m2)-
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Table 1
1 2 3 4 5
Acrylic acid ester-vinyl acetate
acrylic acid copolymer 24 13 - 86 25
Acrylic acid ester-acrylic acid
N-methylol methacrylamide
copolymer 41 67 10 14 45
Acrylic acid ester-ethyl acrylate
N-methylol methacrylamide
acrylic acid copoly~er 35 - 90 - 20
Phthalic acid ester - 20 - - 10
Adhesive power measurements were carried out as per Afera
standard 4001 (immediate measurement) on the self-adhesive fleece
papers produced with the adhesive formulations 1 to 5, but not
on steel, since the fleece paper frequently plucks or splits,
but, on various textiles appropriate to the application. The
measured results are given in the following Table 2.
Tabl~ 2
1 2 3 4 5
Adhesive power fleec~
paper against cotton N/cm 0.07 0.05 0.08 0.17 0.10
Nylon lycra (synthetlc) n O .10 0.07 0.09 0.21 0.12
Polyester wool n 0.45 0.41 0.43 0.39 0.44
Chiffon silk n 0.18 0.15 0.16 0.26 0.18
Linen ~ 0.26 0.38 0.22 0.41 0.39
Mixed fabric made of
synthetics and cotton n O .18 0.24 0.14 0.37 0.27
Fleece paper sample strips with the contact adhesive formulatîons
1 to 5 were stored for 6 weeks at 70C and the adhesive power
determined on various textiles. A reduction in adhesive power was
not observed.
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