U.S. patent application number 13/459778 was filed with the patent office on 2012-11-08 for adhesive tape for jacketing elongate material such as especially cable looms and jacketing method.
This patent application is currently assigned to tesa SE. Invention is credited to Nicolai BOHM, Brigitte KORTHALS, Michel MIES, Dennis SEITZER.
Application Number | 20120282837 13/459778 |
Document ID | / |
Family ID | 46027697 |
Filed Date | 2012-11-08 |
United States Patent
Application |
20120282837 |
Kind Code |
A1 |
KORTHALS; Brigitte ; et
al. |
November 8, 2012 |
Adhesive tape for jacketing elongate material such as especially
cable looms and jacketing method
Abstract
An adhesive tape, especially for wrapping cables, consisting of
a preferably textile carrier and of a pressure-sensitive adhesive
which is applied on at least one side of the carrier and is in the
form of a dried polymer dispersion, the polymer being synthesized
from: e) 90% to 99% by weight of n-butyl acrylate and/or
2-ethylhexyl acrylate f) 0% to 10% by weight of an ethylenically
unsaturated monomer having an acid or acid-anhydride function g)
10% to 1% by weight of one or more ethylenically unsaturated
monofunctional monomers different from (a) and (b) h) 0% to 1% by
weight of a difunctional or polyfunctional monomer and the
pressure-sensitive adhesive comprising between 15 and 100 parts by
weight of a tackifier (based on the mass of the dried polymer
dispersion).
Inventors: |
KORTHALS; Brigitte;
(Hamburg, DE) ; BOHM; Nicolai; (Hamburg, DE)
; SEITZER; Dennis; (Hamburg, DE) ; MIES;
Michel; (Hamburg, DE) |
Assignee: |
tesa SE
Hamburg
DE
|
Family ID: |
46027697 |
Appl. No.: |
13/459778 |
Filed: |
April 30, 2012 |
Current U.S.
Class: |
442/151 ;
156/185; 428/365 |
Current CPC
Class: |
Y10T 428/2915 20150115;
B29K 2067/00 20130101; B29K 2033/08 20130101; C09J 7/38 20180101;
C09J 2203/302 20130101; C09J 2467/006 20130101; C09J 2433/00
20130101; B29C 63/10 20130101; B29L 2023/001 20130101; Y10T
442/2754 20150401; C09J 7/21 20180101; C09J 5/00 20130101 |
Class at
Publication: |
442/151 ;
428/365; 156/185 |
International
Class: |
C09J 7/04 20060101
C09J007/04; B32B 37/18 20060101 B32B037/18; B32B 37/12 20060101
B32B037/12; B32B 5/02 20060101 B32B005/02; B32B 1/00 20060101
B32B001/00 |
Foreign Application Data
Date |
Code |
Application Number |
May 3, 2011 |
DE |
10 2011 075 159.9 |
Claims
1. Adhesive tape consisting of a textile carrier and of a
pressure-sensitive adhesive which is applied on at least one side
of the carrier and is in the form of a dried polymer dispersion,
the polymer being synthesized from: a) 90% to 99% by weight of
n-butyl acrylate and/or 2-ethylhexyl acrylate, b) 0% to 10% by
weight of an ethylenically unsaturated monomer having an acid or
acid-anhydride function, c) 10% to 1% by weight of one or more
ethylenically unsaturated monofunctional monomers different from
(a) and (b), and d) 0% to 1% by weight of a difunctional or
polyfunctional monomer, and the pressure-sensitive adhesive
comprising between 15 and 100 parts by weight of a tackifier (based
on the mass of the dried polymer dispersion).
2. Adhesive tape according to claim 1, wherein acrylonitrile and/or
methacrylonitrile form the monomer (c) or at least part of the
monomers (c).
3. Adhesive tape according to claim 1, wherein 2-ethylhexyl
acrylate forms monomer (a).
4. Adhesive tape according to claim 1, wherein the monomer (a)
consists of 2-ethylhexyl acrylate and at the same time the monomer
(c) or at least part of the monomers (c) consists of acrylonitrile
and/or methacrylonitrile.
5. Adhesive tape according to claim 1, wherein the monomer (b) is
acrylic acid, methacrylic acid, itaconic acid, maleic acid, fumaric
acid and/or maleic anhydride.
6. Adhesive tape according to claim 1, wherein monomer (d) is
divinylbenzene, an alkyl diacrylate, a triacrylate or a
tetraacrylate.
7. Adhesive tape according to claim 1, wherein 20 to 80 parts by
weight of tackifiers have been added.
8. Adhesive tape according to claim 1, wherein tackifiers used are
tackifier resins having a softening point of more than 80.degree.
C. in accordance with ASTM E28-99 (2009).
9. Adhesive tape according to claim 1, wherein the glass transition
temperature of the pressure-sensitive adhesive is less than
+15.degree. C. (determined by DSC (Differential Scanning
Calorimetry) in accordance with DIN 53 765 with a heating rate of
10 K/min).
10. Adhesive tape according to claim 1, wherein the
pressure-sensitive adhesive according to ASTM D3330 has a bond
strength to steel of at least 2.5 N/cm (for an adhesive coatweight
of 100 g/m.sup.2 on a woven polyester fabric carrier).
11. Adhesive tape according to claim 1, wherein the carrier is a
textile carrier.
12. Method of using an adhesive tape according to claim 1 for
jacketing elongate material, comprising passing the adhesive tape
in a helical line around the elongate material.
13. Method of using an adhesive tape according to claim 1 for
jacketing elongate material, comprising wrapping the elongate
material in axial direction by the tape.
14. Elongate material jacketed with an adhesive tape according to
claim 1.
15. Elongate material according to claim 14, which is a cable loom.
Description
[0001] The invention relates to an adhesive tape for jacketing
elongate material such as more particularly cable looms in motor
vehicles, and to methods for jacketing.
[0002] Adhesive tapes have long been used in industry for producing
cable harnesses. In this application the adhesive tapes serve for
the bundling of a multiplicity of electrical leads before
installation or when already mounted, in order to reduce the space
taken up by the bundle of leads, by means of bandaging, and also,
in addition, to obtain protective functions.
[0003] The testing and classifying of adhesive tapes for cable
jacketing takes place in the motor vehicle industry in accordance
with extensive bodies of standards such as, for example, LV 312-1
"Protection systems for wire harnesses in motor vehicles, adhesive
tapes; test guideline" (October 2009), as a joint standard of the
companies Daimler, Audi, BMW and Volkswagen, or the Ford
specification ES-XU5T-1A303-aa (revised version September 2009)
"Harness Tape Performance Specification". In the text below, these
standards are referred to in abbreviated form as LV 312 and Ford
specification, respectively.
[0004] The sound-damping effect, the abrasion resistance and the
temperature stability of an adhesive tape are determined on the
basis of defined test systems and test methods, as described
comprehensively in LV 312.
[0005] Cable wrapping tapes with film and textile carriers are
widespread, being generally coated on one side with various
pressure-sensitive adhesives (PSAs).
[0006] Cable wrapping tapes are required to meet three principal
requirements. [0007] a. Ease of unwind: [0008] The product
dispensed in roll form must be easily unwindable for simple
processing. [0009] b. Flagging resistance: [0010] Flagging--in the
case of an adhesive tape wound around an element--means the
tendency of one end of the adhesive tape to stick up. The cause is
the combination of the adhesive's holding power, the stiffness of
the carrier and the diameter of the cable loom. [0011] In use, ends
of adhesive tapes must not automatically detach. [0012] c. Cable
compatibility: [0013] The cable insulation must not become brittle
as a result of the influence of the adhesive tape in combination
with elevated temperature over a prolonged time period. A
distinction is made here, in accordance with LV 312, between four
temperature classes T1 to T4, corresponding to 80.degree. C. (also
called temperature class A), 105.degree. C. (also called
temperature class B(105)), 125.degree. C. (also called temperature
class C) and 150.degree. C. (also called temperature class D),
which the wrapped cables are required to withstand without
embrittlement for more than 3000 hours. It is obvious that
temperature classes T3 and T4 impose more stringent requirements on
the adhesive tape than the lower classes, T1 and T2. The T1 to T4
classification is decided not only by the cable insulation material
but also by the PSA and type of carrier.
[0014] Cable wrapping tapes with PSAs based on natural rubber
usually exhibit good flagging resistance, but have an unwind force
which increases over the storage time, and especially at increasing
temperatures. Moreover, they meet only the lower temperature
classes for cable compatibility.
[0015] Similar characteristics are exhibited by adhesive tapes
based on synthetic rubbers (styrene block copolymers) such as
SBS/SIS. Even the hydrogenated products are restricted in
temperature class.
[0016] Furthermore, cable wrapping tapes with PSAs based on
UV-crosslinkable polyacrylic esters are encountered. These tapes
meet the high temperature classes, but tend towards flagging.
[0017] In connection with adhesive tapes for cable jacketing, there
are three known patent literature citations that mention acrylates
in the form of polymer dispersions:
[0018] EP 1 132 927 B1 embraces the use of acrylate compositions in
bandaging tapes for cables, with the boundary condition of cable
compatibility that is valid in the present case as well. There is
express mention of an acrylate compound which can be coated in the
form of an aqueous system. The description mentions that the term
"compounds" refers to ready-to-process mixtures of polymers with
the corresponding additives. There is, however, an absence of any
specific indication that the term "additives" also includes
resins.
[0019] On the contrary, it is in fact mentioned that the
temperature stability of the adhesive tape is achieved specifically
by factors including the absence of resins.
[0020] According to EP 0 994 169 B1 it is frequently necessary to
crosslink in order to achieve sufficient cohesion (here in the
sense of chemical resistance). This in turn leads in general to a
reduction in bond strength and tack. The solution lies in a method
for producing adhesive tapes by radiation crosslinking, producing
effective cohesion while retaining a high bond strength. The
adhesives may also be resin-blended acrylates from dispersion;
there are no restrictions on the copolymer composition.
[0021] DE 44 19 169 A1 describes a flame-retarded tape for cable
jacketing, in which both the carrier and the adhesive comprise
flame retardants. In Example 1, explicitly, an adhesive is mixed
from raw materials comprising Primal PS 83 D, a dispersion
acrylate, Snowtack SE 380 A, a dispersion resin, and flame
retardant.
[0022] It is an object of the present invention to provide an
adhesive tape which in spite of easy unwind has good flagging
resistance and at the same time exhibits cable compatibility across
all designated temperature classes, and which allows the
particularly simple, inexpensive and rapid jacketing of elongate
material such as cable looms in motor vehicles.
[0023] This object is achieved by an adhesive tape as specified in
the main claim. The dependent claims provide advantageous
developments of the adhesive tape and methods for employing the
adhesive tape.
[0024] The invention accordingly provides an adhesive tape,
especially for wrapping cables, consisting of a preferably textile
carrier and a pressure-sensitive adhesive which is applied on at
least one side of the carrier and is in the form of a dried polymer
dispersion, the polymer being synthesized from: [0025] a) 90% to
99% by weight of n-butyl acrylate and/or 2-ethylhexyl acrylate
[0026] b) 0% to 10% by weight of an ethylenically unsaturated
monomer having an acid or acid-anhydride function [0027] c) 10% to
1% by weight of one or more ethylenically unsaturated
monofunctional monomers different from (a) and (b) [0028] d) 0% to
1% by weight of a difunctional or polyfunctional monomer and the
pressure-sensitive adhesive comprising between 15 and 100 parts by
weight of a tackifier (based on the mass of the dried polymer
dispersion).
[0029] The adhesive is a pressure-sensitive adhesive (PSA), in
other words an adhesive which even under relatively weak applied
pressure allows durable bonding to virtually all substrates and
which after use can be detached from the substrate again
substantially without residue. A PSA has a permanently
pressure-sensitive adhesive effect at room temperature, in other
words possessing a sufficiently low viscosity and a high tack, and
so the surface of the bonding substrate in question is wetted even
with low applied pressure. The bondability of the adhesive derives
from its adhesive properties, and the redetachability from its
cohesive properties.
[0030] Acrylonitrile and/or methacrylonitrile preferably form the
monomer (c) or at least part of the monomers (c), more preferably
acrylonitrile.
[0031] 2-Ethylhexyl acrylate preferably forms monomer (a).
[0032] According to another preferred embodiment, the monomer (a)
consists of 2-ethylhexyl acrylate and at the same time the monomer
(c) or at least part of the monomers (c) consists of acrylonitrile
and/or methacrylonitrile, preferably of acrylonitrile.
[0033] One particularly preferred embodiment of the invention,
therefore, comprises a mixture of 2-ethylhexyl acrylate as monomer
(a) and acrylonitrile as monomer (c).
[0034] Contemplated advantageously as monomers (b) are, for
example, acrylic acid, methacrylic acid, itaconic acid, maleic
acid, fumaric acid and/or maleic anhydride.
[0035] Preference is given to acrylic acid or methacrylic acid,
optionally to the mixture of both.
[0036] Monomers (c) include alkyl (meth)acrylates, preferably
C.sub.1 to C.sub.20 alkyl(meth)acrylates with the exception of the
monomers forming (a), aromatic vinyl monomers such as styrene,
a-methylstyrene and vinyltoluene, C.sub.1 to C.sub.10
hydroxyalkyl(meth)acrylates such as, more particularly,
hydroxyethyl or hydroxypropyl(meth)acrylate, vinyl esters of
carboxylic acids containing up to 20 carbon atoms, such as vinyl
acetate or vinyl laurate, vinyl ethers of alcohols containing up to
10 carbon atoms, such as vinyl methyl ether or vinyl isobutyl
ether, vinyl halides such as vinyl chloride or vinylidene
dichloride, acid amides such as arylamide or methacrylamide, and
unsaturated hydrocarbons having 2 to 8 carbon atoms such as
ethylene, propene, butadiene, isoprene, 1-hexene or 1-octene.
[0037] Particularly preferred in accordance with the invention is
acrylonitrile.
[0038] Examples of polyfunctional ethylenically unsaturated
monomers (d) are divinylbenzene, alkyl diacrylates such as
1,2-ethylene glycol diacrylate, 1,4-butanediol diacrylate,
1,6-hexanediol diacrylate, 1,8-octanediol diacrylate or
1,12-dodecanediol diacrylate, triacrylates such as
trimethylolpropane triacrylate and tetraacrylates such as
pentaerythritol tetraacrylate.
[0039] The polymer dispersion is prepared by the process of the
emulsion polymerization of the stated components. Descriptions of
this process are given for example in "Emulsion Polymerization and
Emulsion Polymers" by Peter A. Lovell and Mohamed S.
El-Aasser--Wiley-VCH 1997--ISBN 0-471-96746-7 or in EP 1 378 527
B1.
[0040] In order to obtain pressure-sensitive adhesive properties,
the adhesive at the processing temperature must be situated above
its glass transition temperature, in order to have viscoelastic
properties. Since cable loom wrapping takes place at normal ambient
temperture (approximately between 15.degree. C. to 25.degree. C.),
the glass transition temperture of the PSA formulation
(polymer/tackifier mixture) is preferably below +15.degree. C.
(determined by DSC (Differential Scanning Calorimetry) in
accordance with DIN 53 765 with a heating rate of 10 K/min).
[0041] The glass transition temperature of the acrylate copolymers
can be estimated in accordance with the equation of Fox from the
glass transition temperatures of the homopolymers and their
relative proportions (cf. T. G. Fox, Bull. Am. Phys. Soc. 1 (1956)
123). The tackifiers raise the glass transition temperature
automatically, depending on amount added, compatibility and
softening temperature, by around 5 to 40 K. Consequently, only
acrylate copolymers having a glass transition temperature of
0.degree. C. at most are suitable.
[0042] Preference is given additionally to polymers which in
addition to the comonomer composition of the invention have a bond
strength to steel in accordance with ASTM D3330 of at least 1.0
N/cm (for an adhesive coatweight of 30 g/m.sup.2 on a 23 .mu.m
polyester film carrier).
[0043] In the wrapping of a cable loom, the adhesive tape is bonded
with from no overlap at all to complete overlap around the cable,
the radius of which is generally small, meaning that the adhesive
tape is very sharply curved. At the end of a wrapped section, the
tape is typically wrapped primarily onto its own reverse face, so
that the degree of overlap is virtually complete, similar to the
customary presentation form of an adhesive tape roll, where the
adhesive is likewise bonded to its own reverse face. In the event
of flagging, static forces are acting, such as, for example,
through the flexural stiffness of the carrier and the wrapping
tension, and may result in the open ends of adhesive tape standing
up undesirably, similar to the start of automatic unwinding. The
flagging resistance, then, is the capacity of the adhesive to
resist this static force.
[0044] The polymer dispersion alone does not meet the requirements
imposed on an adhesive tape for wrapping cables. In particular, the
required flagging resistance is insufficient.
[0045] The use of tackifiers for the purpose of raising the bond
strengths of PSAs is known in principle. For the skilled person it
is therefore obvious to improve the flagging resistance by using
tackifiers. Precisely this effect is observed if the adhesive is
admixed typically with 15 to 100 parts by weight of tackifiers
(based on the solids), usually 20 to 80 parts by weight, more
preferably 30 to 50 parts by weight.
[0046] Surprisingly and unforeseeably for the skilled person, the
use of tackifier resins in the case of the adhesive tape of the
invention does not lead at the same time to difficult unwind,
despite the fact that a common factor of the two requirements is
that the PSA has contact with its own reverse face.
[0047] Suitability as tackifiers, also referred to as tackifier
resins, is possessed in principle by all known classes of compound.
Tackifiers are, for example, hydrocarbon resins (for example
polymers based on unsaturated C.sub.5 or C.sub.9 monomers), terpene
phenolic resins, polyterpene resins based on raw materials such as,
for example, .alpha.- or .beta.-pinene, aromatic resins such as
coumarone-indene resins or resins based on styrene or
.alpha.-methylstyrene such as rosin and its derivatives, for
example disproportionated, dimerized or esterified rosin, for
example reaction products with glycol, glycerol or pentaerythritol,
to name but a few. Preferred resins are those without readily
oxidizable double bonds, such as terepene phenolic resins, aromatic
resins, and more preferably resins produced by hydrogenation, such
as hydrogenated aromatic resins, hydrogenated polycyclopentadiene
resins, hydrogenated rosin derivatives or hydrogenated polyterpene
resins, for example.
[0048] Preferred resins are those based on terpene phenols and
rosin esters. Likewise preferred are tackifier resins having a
softening point of more than 80.degree. C. in accordance with ASTM
E28-99 (2009). Particularly preferred resins are those based on
terpene phenols and/or rosin esters having a softening point of
more than 90.degree. C. in accordance with ASTM E28-99 (2009). The
resins are usefully employed in dispersion form. In that way they
can easily be mixed in finely divided form with the polymer
dispersion.
[0049] One particularly preferred embodiment of the invention,
then, embraces a mixture of 2-ethylhexyl acrylate as monomer (a)
and also acrylonitrile as monomer (c) and terpene phenols and/or
rosin esters having a softening point of more than 90.degree. C. in
accordance with ASTM E28-99 (2009).
[0050] To achieve further improvement in cable compatibility, the
adhesive formulation may optionally be blended with light
stabilizers or primary and/or secondary ageing inhibitors.
[0051] Ageing inhibitors used may be products based on sterically
hindered phenols, phosphites, thiosynergists, sterically hindered
amines or UV absorbers.
[0052] Preference is given to using primary antioxidants such as,
for example, Irganox 1010 or Irganox 254, alone or in combination
with secondary antioxidants such as, for example, Irgafos TNPP or
Irgafos 168.
[0053] These ageing inhibitors may be used in any desired
combination with one another, with mixtures of primary and
secondary antioxidants in combination with light stabilizers such
as Tinuvin 213, for example, exhibiting particularly good
ageing-inhibition effect.
[0054] Ageing inhibitors in which a primary antioxidant is united
with a secondary antioxidant in one molecule have proved to be
especially advantageous. These ageing inhibitors comprise cresol
derivatives whose aromatic ring is substituted at two arbitrary,
different locations, preferably in ortho- and meta-position
relative to the OH group, by thioalkyl chains, it also being
possible for the sulphur atom to be joined to the aromatic ring of
the cresol building block via one or more alkyl chains. The number
of carbon atoms between the aromatic moiety and the sulphur atom
may be between 1 and 10, preferably between 1 and 4. The number of
carbon atoms in the alkyl side chain may be between 1 and 25,
preferably between 6 and 16. Particularly preferred in this context
are compounds of the 4,6-bis(dodecylthiomethyl)-o-cresol,
4,6-bis(undecylthiomethyl)-o-cresol,
4,6-bis(decyl-thiomethyl)-o-cresol
4,6-bis(nonylthiomethyl)-o-cresol or
4,6-bis(octylthiomethyl)-o-cresol type. Ageing inhibitors of these
kinds are available for example from the company Ciba Geigy under
the name Irganox 1726 or Irganox 1520.
[0055] The amount of the ageing inhibitor or ageing inhibitor
package added ought to be situated within a range between 0.1 and
10% by weight, preferably in a range between 0.2 and 5% by weight,
more preferably in a range between 0.5 and 3% by weight, based on
the overall solids content.
[0056] Preference is given to a presentation form in the form of a
dispersion for particularly simple miscibility with the adhesive
dispersion. Alternatively it is also possible for liquid ageing
inhibitors to be incorporated directly into the dispersion, in
which case the step of incorporation ought to be followed by a
standing time of a number of hours, to allow the homogeneous
distribution of the ageing inhibitor in the dispersion or its
acceptance into the dispersion particles. A further alternative is
the addition of an organic solution of the ageing inhibitors to the
dispersion.
[0057] Suitable concentrations lie in the range from 0.1 up to 5
parts by weight, based on the solids.
[0058] For improving the processing properties, the adhesive
formulation may further be blended with customary process
auxiliaries such as rheological additives (thickeners), defoamers,
deaerating agents, wetting agents or flow control agents. Suitable
concentrations are in the range from 0.1 up to 5 parts by weight,
based on the solids.
[0059] Fillers (reinforcing or non-reinforcing) such as silicon
dioxides (spherical, acicular, platelet-shaped or irregular like
the fumed silicas), glass in the form of solid or hollow beads,
microballoons, calcium carbonates, zinc oxides, titanium dioxides,
aluminium oxides or aluminium oxide hydroxides may serve for
fine-tuning the processing properties and also the technical
adhesive properties. Suitable concentrations are in the range from
0.1 up to 20 parts by weight, based on the solids.
[0060] In one preferred embodiment the adhesive formulation of the
invention has a bond strength to steel in accordance with ASTM
D3330 of at least 2.5 N/cm (for an adhesive coatweight of about 100
g/m.sup.2 on a woven polyester carrier, in accordance with the
examples).
[0061] Suitable carriers include in principle all carrier
materials, preferably textile carriers and more preferably woven
fabrics, more particularly woven polyester fabrics.
[0062] As carrier material for the adhesive tape it is possible to
use all known textile carriers such as knitted fabrics, scrims,
tapes, braids, tufted textiles, felts, woven fabrics (encompassing
plain weave, twill and satin weave), knitted fabrics (encompassing
warp knits and other knits) or nonwoven webs, the term "nonwoven
web" comprehending at least sheetlike textile structures in
accordance with EN 29092 (1988) and also stitchbonded webs and
similar systems.
[0063] It is likewise possible to use woven and knitted spacer
fabrics with lamination.
[0064] Spacer fabrics of these kinds are disclosed in EP 0 071 212
B1. Spacer fabrics are mat-like layer structures comprising a cover
layer of a fibre or filament web, an underlayer and individual
retaining fibres or bundles of such fibres between these layers,
these fibres being distributed over the area of the layer
structure, being needled through the particle layer and joining the
cover layer and the underlayer to one another. As an additional
although not mandatory feature, the retaining fibres in accordance
with EP 0 071 212 B1 contain particles of inert minerals, such as
sand, gravel or the like, for example.
[0065] The retaining fibres needled through the particle layer hold
the cover layer and the underlayer at a distance from one another
and are joined to the cover layer and the underlayer.
[0066] Nonwovens contemplated include, in particular, consolidated
staple fibre webs, but also filament webs, meltblown webs and
spunbonded webs, which generally require additional consolidation.
Possible consolidation methods known for webs include mechanical,
thermal and chemical consolidation. Whereas with mechanical
consolidations the fibres are held together purely mechanically
usually by entanglement of the individual fibres, by the
interlooping of fibre bundles or by the stitching-in of additional
threads, it is possible by thermal and by chemical techniques to
obtain adhesive (with binder) or cohesive (binderless) fibre-fibre
bonds. Given appropriate formulation and an appropriate process
regime, these bonds may be restricted exclusively, or at least
predominantly, to fibre nodal points, so that a stable,
three-dimensional network is formed while nevertheless retaining
the relatively loose, open structure in the web.
[0067] Webs which have proved to be particularly advantageous are
those consolidated in particular by overstitching with separate
threads or by interlooping.
[0068] Consolidated webs of this kind are produced for example on
stitchbonding machines of the "Malimo" type from the company Karl
Mayer, formerly Malimo, and can be obtained from companies
including Techtex GmbH. A Malifleece is characterized in that a
cross-laid web is consolidated by the formation of loops from
fibres of the web.
[0069] The carrier used may also be a web of the Kunit or
Multilknit type. A Kunit web is characterized in that it originates
from the processing of a longitudinally oriented fibre web to form
a sheetlike structure which has loops on one side and has loop feet
or pile fibre folds on the other side, but possesses neither
threads nor prefabricated sheetlike structures. A web of this kind
as well has been produced for a relatively long time, for example
on stitchbonding machines of the "Malimo" type from the company
Karl Mayer. A further characterizing feature of this web is that,
as a longitudinal-fibre web, it is able to absorb high tensile
forces in the longitudinal direction. The characteristic feature of
a Multiknit web relative to the Kunit web is that the web is
consolidated on both the top and bottom sides by virtue of the
double-sided needle punching. The starting product used for a
Multiknit is generally one or two single-sidedely interlooped pile
fibre nonwovens produced by the Kunit process. In the end product,
both top sides of the nonwovens are shaped by means of interlooped
fibres to form a closed surface, and are joined to one another by
fibres which stand almost perpendicularly. An additional
possibility is to introduce further needlable sheetlike structures
and/or scatterable media.
[0070] Finally, stitchbonded webs as an intermediate are also
suitable for forming a liner of the invention and an adhesive tape
of the invention. A stitchbonded web is formed from a nonwoven
material having a large number of stitches extending parallel to
one another. These stitches are brought about by the stitching-in
or stitchbonding of continuous textile threads. For this type of
web, stitchbonding machines of the "Malimo" type from the company
Karl Mayer are known.
[0071] Also particularly suitable are needlefelt webs. In a
needlefelt web, a tuft of fibres is made into a sheetlike structure
by means of needles provided with barbs. By alternate introduction
and withdrawal of the needles, the material is consolidated on a
needle bar, with the individual fibres interlooping to form a firm
sheetlike structure. The number and configuration of the needling
points (needle shape, penetration depth, double-sided needling)
determine the thickness and strength of the fibre structures, which
are in general lightweight, air-permeable and elastic.
[0072] Also particularly advantageous is a staple fibre web which
is mechanically preconsolidated in the first step or is a wet-laid
web laid hydrodynamically, in which between 2% and 50% by weight of
the web fibres are fusible fibres, more particularly between 5% and
40% by weight of the web fibres.
[0073] A web of this kind is characterized in that the fibres are
laid wet or, for example, a staple fibre web is preconsolidated by
the formation of loops from fibres of the web by needling,
stitching or air-jet and/or water-jet treatment.
[0074] In a second step, thermofixing takes place, with the
strength of the web being increased again by the melting, or
partial melting, of the fusible fibres.
[0075] For the utilization of nonwovens in accordance with the
invention, the adhesive consolidation of mechanically
preconsolidated or wet-laid webs is of particular interest, it
being possible for said consolidation to take place by way of the
addition of binder in solid, liquid, foamed or paste-like form. A
great diversity of theoretical presentation forms is possible: for
example, solid binders as powders for trickling in; as a sheet or
as a mesh; or in the form of binding fibres. Liquid binders may be
applied as solutions in water or organic solvents, or as a
dispersion. For adhesive consolidation, binding dispersions are
predominantly selected: thermosets in the form of phenolic or
melamine resin dispersions, elastomers as dispersions of natural or
synthetic rubbers or, usually, dispersions of thermoplastics such
as acrylates, vinyl acetates, polyurethanes, styrene-butadiene
systems, PVC, and the like, and also copolymers thereof. Normally
the dispersions are anionically or nonionically stabilized,
although in certain cases cationic dispersions may also be of
advantage.
[0076] The binder may be applied in a manner which is in accordance
with the prior art and for which it is possible to consult, for
example, standard works of coating or of nonwoven technology such
as "Vliesstoffe" (Georg Thieme Verlag, Stuttgart, 1982) or
"Textiltechnik-Vliesstofferzeugung" (Arbeitgeberkreis Gesamttextil,
Eschborn, 1996).
[0077] For mechanically preconsolidated webs which already possess
sufficient composite strength, the single-sided spray application
of a binder is appropriate for producing specific changes in the
surface properties.
[0078] Such a procedure not only is sparing in its use of binder
but also greatly reduces the energy requirement for drying. Since
no squeeze rolls are required and the dispersions remain
predominantly in the upper region of the nonwoven, unwanted
hardening and stiffening of the web can be largely prevented.
[0079] For sufficient adhesive consolidation of the web carrier,
the addition of binder in the order of magnitude of 1% to 50%, more
particularly 3% to 20%, based on the weight of the fibre web, is
generally required.
[0080] The binder may be added as early as during the manufacture
of the web, in the course of mechanical preconsolidation, or else
in a separate process step, which may be carried out in-line or
off-line. Following the addition of binder, it is necessary
temporarily to generate a condition for the binder in which the
binder becomes adhesive and adhesively connects the fibres--this
may be achieved during the drying, for example, of dispersions, or
else by means of heating, with further possibilities for variation
existing by way of areal or partial application of pressure. The
binder may be activated in known drying tunnels, given an
appropriate selection of binder, or else by means of infra-red
radiation, UV radiation, ultra-sound, high-frequency radiation or
the like. For the subsequent end use it is sensible, though not
absolutely necessary, for the binder to have lost its tack
following the end of the web production process. It is advantageous
that, as a result of thermal treatment, volatile components such as
fibre assistants are removed, giving a web having favourable
fogging values, so that when a low-fogging adhesive is used, it is
possible to produce an adhesive tape having particularly favourable
fogging values; accordingly, the liner as well has a very low
fogging value.
[0081] By fogging (see DN 75201 A) is meant the effect where, under
unfavourable conditions, compounds of low molecular mass may outgas
from the adhesive tapes and condense on cold parts. As a result of
this it is possible, for example, for the view through the
windscreen to be adversely affected.
[0082] A further special form of adhesive consolidation involves
activating the binder by partial dissolution or partial swelling.
In this case it is also possible in principle for the fibres
themselves, or admixed speciality fibres, to take over the function
of the binder. Since, however, such solvents are objectionable on
environmental grounds, and/or are problematic in their handling,
for the majority of polymeric fibres, this process is not often
employed.
[0083] Advantageously and at least in regions, the carrier may have
a single-sidedly or double-sidedly polished surface, preferably in
each case a surface polished over the whole area. The polished
surface may be chintzed, as elucidated in detail in EP 1 448 744
A1, for example.
[0084] Furthermore, the carrier may be compacted by calendering on
a roll mill. The two rolls preferably run in opposite directions
and at the same peripheral speed, causing the carrier to be pressed
and compacted.
[0085] If there is a difference in the peripheral speed of the
rolls, then the carrier is additionally polished.
[0086] Starting materials for the carrier material for the adhesive
tape are more particularly (manmade) fibres (staple fibre or
continuous filament) made from synthetic polymers, also called
synthetic fibres, made from polyester, polyamide, polyimide,
aramid, polyolefin, polyacrylonitrile or glass, (manmade) fibres
made from natural polymers such as cellulosic fibres (viscose,
Modal, Lyocell, Cupro, acetate, triacetate, Cellulon), such as
rubber fibres, such as plant protein fibres and/or such as animal
protein fibres and/or natural fibres made of cotton, sisal, flax,
silk, hemp, linen, coconut or wool. The present invention, however,
is not confined to the materials stated; it is instead possible, as
evident to the skilled person without having to take an inventive
step, to use a multiplicity of further fibres in order to produce
the carrier.
[0087] Likewise suitable, furthermore, are yarns fabricated from
the fibres specified.
[0088] In the case of woven fabrics or scrims, individual threads
may be produced from a blend yarn, and thus may have synthetic and
natural constituents. Generally speaking, however, the warp threads
and the weft threads are each formed of a single kind.
[0089] The warp threads and/or the weft threads here may in each
case be composed only of synthetic threads or only of threads made
from natural raw materials--in other words, of a single kind.
[0090] Also suitable for the adhesive tape is a carrier material
which consists of paper, of a laminate, of a film (for example PP,
PE, PET, PA, PU), of foam or of a foamed film.
[0091] These non-textile sheetlike materials are especially
appropriate when specific requirements necessitate such a
modification of the invention. Films are generally thinner in
comparison to textiles, for example, and, as a result of the
imperforate layer, offer additional protection against penetration
by chemicals and service fluids such as oil, petrol, antifreeze and
the like into the actual cable area, and can be substantially
adapted to requirements by an appropriate selection of the material
from which they are constructed. With polyurethanes or polyolefin
copolymers, for example, flexible and elastic jackets can be
produced; with polyester and polyamides, good abrasion resistance
and temperature stability are achieved.
[0092] Foams or foamed films, on the other hand, possess the
qualities of more substantial space filling and of good
soundproofing--where a length of cable is laid, for example, in a
duct-like or tunnel-like area in the vehicle, a jacketing tape of
appropriate thickness and soundproofing can prevent disruptive
flapping and vibration from the outset.
[0093] The adhesive tape may ultimately have a liner material, with
which the one or two layers of adhesive are lined before use.
Suitable liner materials also include all of the materials set out
comprehensively above.
[0094] It is preferred to use a non-linting material such as a
polymeric film or a well-sized, long-fibre paper.
[0095] If the adhesive tape described is to be of low flammability,
this quality can be achieved by adding flame retardants to the
carrier and/or to the adhesive. These retardants may be
organobromine compounds, if required with synergists such as
antimony trioxide, although, with regard to the absence of halogen
from the adhesive tape, preference will be given to using red
phosphorus, organophosphorus compounds, mineral compounds or
intumescent compounds such as ammonium polyphosphate, alone or in
conjunction with synergists.
[0096] The general expression "adhesive tape" in the context of
this invention encompasses all sheetlike structures such as
two-dimensionally extended sheets or sheet sections, tapes with
extended length and limited width, tape sections and the like, and
also, lastly, diecuts or labels.
[0097] The adhesive tape may be produced in the form of a roll, in
other words rolled up onto itself in the form of an archimedian
spiral.
[0098] Applied to the reverse of the adhesive tape may be a
reverse-face varnish, in order to exert a favourable influence on
the unwind properties of the adhesive tape wound into the
archimedian spiral. This reverse-face varnish may for this purpose
be furnished with silicone compounds or fluorosilicone compounds
and also with polyvinylstearylcarbamate,
polyethyleneiminestearylcarbamide or organofluorine compounds as
abhesive substances.
[0099] The adhesive may be applied in the longitudinal direction of
the adhesive tape, in the form of a stripe, the width of the stripe
being lower than that of the carrier of the adhesive tape.
[0100] Depending on the particular utility, there may also be a
plurality of parallel stripes of the adhesive coated on the carrier
material.
[0101] The position of the stripe on the carrier is freely
selectable, with preference being given to an arrangement directly
at one of the edges of the carrier.
[0102] The adhesive is preferably applied over the full area to the
carrier.
[0103] Provided on the adhesive coating of the carrier there may be
at least one stripe of a covering, extending in the longidutinal
direction of the adhesive tape and covering between 20% and 90% of
the adhesive coating.
[0104] The stripe preferably covers in total between 50% and 80% of
the adhesive coating. The degree of coverage is selected according
to the application and to the diameter of the cable loom.
[0105] The percentage figures indicated relate to the width of the
stripes of the covering in relation to the width of the
carrier.
[0106] In accordance with one preferred embodiment of the invention
there is precisely one stripe of the covering present on the
adhesive coating.
[0107] The position of the stripe on the adhesive coating is freely
selectable, with preference being given to an arrangement directly
at one of the longitudinal edges of the carrier. In this way an
adhesive stripe is produced which extends in the longitudinal
direction of the adhesive tape and finishes at the other
longitudinal edge of the carrier.
[0108] Where the adhesive tape is used for jacketing a cable
harness, by the adhesive tape being passed in a helicoidal movement
around the cable harness, the wrapping of the cable harness may be
accomplished by bonding the adhesive of the adhesive tape only to
the adhesive tape itself, with the substrate not coming into
contact with any adhesive.
[0109] The cable harness jacketed in this way has a very high
flexibility, as a result of the absence of fixing of the cable by
any adhesive. Consequently the flexibility of said cable harness on
installation--particularly in narrow passages or sharp bends--is
significantly increased.
[0110] If a certain degree of fixing of the adhesive tape on the
substrate is desired, the jacketing may be accomplished by bonding
part of the adhesive stripe to the adhesive tape itself and another
part to the substrate.
[0111] In accordance with another advantageous embodiment, the
stripe is applied centrally on the adhesive coating, thereby
producing two adhesive stripes extending on the longitudinal edges
of the carrier in the longitudinal direction of the adhesive
tape.
[0112] For the secure and economic application of the adhesive tape
in said helicoidal movement around the cable harness, and to
counter the slipping of the resultant protective wrapping, the two
adhesive stripes each present on the longitudinal edges of the
adhesive tape are advantageous, especially if one stripe, which is
usually narrower than the second stripe, serves as a fixing aid and
the second, broader stripe serves as a fastener. In this way, the
adhesive tape is bonded to the cable in such a way that the cable
harness is secured against slipping but is nevertheless of flexible
design.
[0113] In addition there are embodiments in which more than one
stripe of the covering is applied to the adhesive coating. Where
reference is made only to one stripe, the skilled person reads
this, conceptually, as accommodating the possibility that there may
well be two or more stripes covering the adhesive coating at the
same time.
[0114] The procedure for producing the adhesive tape of the
invention involves nothing more than the coating of the carrier
directly with the dispersion in one or more operations carried out
in succession. In the case of textile carriers, the untreated
textile can be coated directly or by a transfer process.
Alternatively the textile may be pretreated with a coating (using
any desired film-forming substance from solution, dispersion, melt
and/or radiation-curing), before then being provided, in a
downstream work-step, directly or by a transfer process, with the
PSA.
[0115] Application assemblies used are the customary ones: wire
doctor, coating bar, roll application, nozzle coating, twin-chamber
doctor blade, multiple cascade die.
[0116] On the basis of the positive properties outlined, the
adhesive tape can be used outstandingly for insulating and wrapping
wires or cables.
[0117] Furthermore, it is advantageously suitable for the jacketing
of elongate material such as, more particularly, cable looms in
motor vehicles, with the adhesive tape being passed in a helical
line around the elongate material, or the elongate material being
wrapped in axial direction by the tape.
[0118] Lastly, the concept of the invention also embraces an
elongate material jacketed with an adhesive tape of the invention.
The elongate material is preferably a cable loom.
[0119] On account of the outstanding suitability of the adhesive
tape, it can be used in a jacket that consists of a covering,
where, at least in one edge region of the covering, the
self-adhesive tape is present, and is bonded on the covering in
such a way that the adhesive tape extends over one of the
longitudinal edges of the covering, and preferably in an edge
region which is narrow by comparison with the width of the
covering.
[0120] One such product and also optimized embodiments thereof are
disclosed in EP 1 312 097 A1. EP 1 300 452 A2, DE 102 29 527 A1 and
WO 2006 108 871 A1 show ongoing developments for which the adhesive
tape of the invention is likewise very suitable. The adhesive tape
of the invention may also find use in a method of the kind
disclosed by EP 1 367 608 A2.
[0121] Finally, EP 1 315 781 A1 and DE 103 29 994 A1 describe
embodiments of adhesive tapes of a kind also possible for the
adhesive tape of the invention.
[0122] With further preference the adhesive tape, in bonding to
cables with PVC jacketing and to cables with polyolefin jacketing,
does not destroy these systems when an assembly composed of cables
and adhesive tape is, in accordance with LV 312, stored at
temperatures above 100.degree. C. for up to 3000 hours and then the
cables are bent around a mandrel.
[0123] The adhesive tape of the invention is outstandingly suitable
for the wrapping of cables, can be easily unwound for simple
processing, exhibits little or no flagging, and exhibits no cable
embrittlement even in the high temperature classes T3 and T4 over
3000 hours.
[0124] The purpose of the text below is to illustrate the adhesive
tape using a number of figures, without wishing thereby to bring
about a restriction of whatever kind.
[0125] FIG. 1 shows one embodiment of an adhesive tape according to
the invention in a lateral section,
[0126] FIG. 2 shows a cut-out section of a cable harness which is
composed of a bundle of individual cables and is jacketed with the
adhesive tape of the invention,
[0127] FIG. 3 shows an advantageous application of the adhesive
tape,
[0128] FIG. 4 shows a test specimen in schematic,
[0129] FIG. 5 shows a test specimen with the assembly
perforated,
[0130] FIG. 6 shows a test specimen bonded centrally to strips of a
broader adhesion base so that the small piece of card still
overlaps just at the end, and
[0131] FIG. 7 shows the finished test samples, in other words the
test strips together with adhesion base adhered to the card core in
such a way that the upper end of the test specimen overaps the
vertex point by a small amount.
[0132] Shown in FIG. 1, in a section in the transverse direction
(transverse section), is the adhesive tape, consisting of a woven
fabric carrier 1, on one side of which a layer of a self-adhesive
coating 2 is applied.
[0133] FIG. 2 shows a cut-out section of a cable harness which is
composed of a bundle of individual cables 7 and is jacketed with
the adhesive tape 11 of the invention. The adhesive tape is passed
in a helicoidal movement around the cable harness.
[0134] The cut-out section of cable harness shown has two turns I
and II of the adhesive tape. Further turns would extend towards the
left, but are not shown here.
[0135] In a further embodiment for jacketing, two tapes 60, 70 of
the invention, furnished with an adhesive, are laminated with their
adhesives at an offset (preferably by 50% in each case) to one
another, producing a product as shown in FIG. 3.
EXAMPLES
Outline of the Examples
[0136] The adhesive tape of the invention is described below in a
preferred embodiment by means of a number of examples, without
wishing thereby to subject the invention to any restriction
whatsoever.
[0137] In addition, comparative examples are given, which show
unsuitable adhesive tapes.
[0138] To illustrate the invention, example adhesive tapes were
produced according to the following scheme:
[0139] The PSA dispersions were mixed from polymer dispersion and
resin dispersion in line with the example formulas, and were
intimately homogenized using a stirrer. The PSA dispersions were
subsequently adjusted, by stirred incorporation of a polyurethane
associative thickener (Borchigel 0625, OMG Borchers), to a
viscosity of approximately 5000 Pa*s at a shear rate of 0.01
s.sup.-1 (measured using cone/plate geometry in rotation mode with
a DSR 200 N rheometer from Rheometric Scientific).
[0140] Using a film-drawing apparatus, a woven polyester fabric
(linear fibre density 167 dtex, thread count warp 48.5 1/cm, thread
count weft 23 1/cm) was coated with the thickened example PSA
dispersion in such a way as to result, after drying in a forced-air
oven at 85.degree. C. for 5 minutes, in an adhesive coatweight of
approximately 20 g/m.sup.2.
[0141] In a second work-step, the fabric impregnated in this way
was coated analogously with the same dispersion, so as to result,
after drying in a forced-air oven at 85.degree. C. for 10 minutes,
in a total adhesive coatweight of 100 g/m.sup.2.
Assessment Criteria
[0142] The criteria for an application-compatible adhesive tape for
the wrapping of cables are [0143] unwind force from rolls after
storage at 40.degree. C. for 4 weeks [0144] flagging resistance as
per the TFT test [0145] cable compatibility according to LV 312
Procedure of the Tests
[0146] Unless expressly stated otherwise, the measurements are
carried out under test conditions of 23.+-.1.degree. C. and
50.+-.5% relative humidity.
[0147] Measurement of Unwind Force to LV312
[0148] Here, a value in the range from about 3 to 9 N/cm at a
take-off speed of 30 m/min is considered to be compatible with the
application and is scored as "1". Values outside the range receive
a score of "0".
[0149] Measurement of Flagging Resistance to LV312 or TFT Method
(Threshold Flagging Time)
[0150] For determining the flagging behaviour by the TFT method, a
test is employed in which an additional flexural stress is
generated by the application of the test specimens, prepared in a
flat format, to a 11/2'' core. The combination of tensile load by a
test weight and flexural stress causes flagging-like detachment of
the adhesive tape starting from the bonded upper end, and ultimate
failure by dropping of the test specimens (see FIG. 4, which also
shows the schematic construction).
[0151] The time in minutes before dropping is the result.
[0152] The critical parameters for the holding time of the test
specimens are weight and temperature, the weight being selected
such as to result in values of at least 100 minutes.
[0153] The cylindrically shaped test mandrel is a 11/2'' card core
with an external diameter of 42.+-.2 mm, provided with a marking
line 5 mm adjacent to the vertex line.
[0154] The adhesion base is the adhesive tape's own reverse
face.
[0155] The manual roller has a weight of 2 kg.
[0156] The test weight is 1 kg.
[0157] The test conditions are 23.+-.1.degree. C. and 50.+-.5%
relative humidity, or 40.degree. C. in the heating cabinet.
[0158] The test is carried out on strips of adhesive tape 19 mm
wide. A strip with a length of 400 mm is adhered to release paper
and cut to form three strips with a length of 100 mm each. This
should be done using a fresh cutter blade. The reverse face must
not be touched.
[0159] A small piece of card is adhered beneath one of the ends of
each strip, and the assembly is perforated (see FIG. 5).
[0160] The test strips are then individually bonded centrally to
strips of the broader adhesion base (adhesive tape with a width
11/2 times that of the adhesive tape under test), so that the small
piece of card still overlaps just (2 to 3 mm) at the end (see FIG.
6).
[0161] The test specimens are rolled down using the 2 kg manual
roller at a rate of 10 m/min in 3 cycles.
[0162] The finished test samples, in other words the test strips
together with adhesion base, are then adhered to the card core in
such a way that the upper end of the test specimen overaps the
vertex point by 5 mm (see FIG. 7). In this operation, only the
adhesion base, and not the test specimen, must be pressed on.
[0163] The test specimens fully prepared are left for 20.+-.4 hours
without weight loading in a controlled-climate chamber at
40.degree. C.
[0164] Weights with a mass of one kilogram are then hung onto the
specimens, and the stopwatches are started.
[0165] The measurement ends after failure of all three test
specimens of one sample.
[0166] The median of the three individual measurements is reported
in minutes.
[0167] The holding time is reported in minutes.
[0168] In this context, a TFT value of >1200 minutes is
considered to be a lower limit with regard to resistance to
flagging.
[0169] Values below this receive a score of 0, values from 1201 to
2000 minutes receive a score of 1, values from 2001 to 5000 minutes
receive a score of 2, and values above 5001 minutes receive a score
of 3. These gradations reflect increasing security against
flagging.
[0170] Measurement of Cable Compatibility to LV312
[0171] Cable compatibility is considered to exist when there is no
embrittlement after 3000 hours at 150.degree. C. on bending around
a mandrel with a diameter of 2 mm, and this is given a score of
"1". Values outside this receive a score of "0".
[0172] Measurement of Bond Strength
[0173] For measuring the bond strength of the pure dispersions,
coated-out samples of the adhesives were prepared first of all. For
this purpose, the dispersions were applied to a PET film
(polyethylene terephthalate) with a thickness of 23 .mu.m, and were
drawn down using a film-drawing apparatus in such a way as to
result, after drying for 5 minutes at 105.degree. C. in a
forced-air drying cabinet, in an adhesive coatweight of 30
g/m.sup.2.
[0174] Using a cutter knife, strips 20 mm wide and 25 cm long were
cut from this sheet.
[0175] For measuring the bond strength of the formulations with
resin, coated-out samples were drawn down as described above onto
woven polyester fabrics, and likewise cut using a cutter knife into
strips 20 mm wide and 25 cm long.
[0176] The bond strength to steel was measured in accordance with
ASTM D3330.
Measurement of Glass Transition Temperatues
[0177] The glass transition temperatures were determined on the DSC
204 F1 "Phonix" Dynamic Differential Scanning Calorimeter from
Netzsch, Germany, in 25 .mu.l aluminium crucibles with a perforated
lid, under a nitrogen atomosphere (20 ml/min gas flow rate). The
initial sample mass was 8.+-.1 mg. The samples were subjected to
measurement twice from -140.degree. C. to 200.degree. C., with a
heating rate of 10 K/min. The subject analysis was the 2nd heating
curve.
[0178] The method is based on DIN 53 765.
Composition of Example Polymer Dispersions
[0179] To illustrate the concept of the invention, polymer
dispersions having the following comonomer composition were
trialled:
TABLE-US-00001 Monomer Polymer 1 Polymer 2 Polymer 3 2-Ethylhexyl
acrylate 93 92 Butyl acrylate 95 Acrylic acid 4 2 1 Acrylonitrile 3
-- -- Methyl methacrylate -- 6 -- Vinyl acetate -- -- 4
[0180] The bond strengths to steel of polymers 1 to 3 were measured
as follows (figure in N/cm):
TABLE-US-00002 Polymer 1 Polymer 2 Polymer 3 2.8 1.4 1.9
[0181] The glass transition temperatures of polymers 1 to 3 were
measured as follows (figure in .degree. C.):
TABLE-US-00003 Polymer 1 Polymer 2 Polymer 3 -47 -48 -36
[0182] Polymer 1 was used to formulate the pressure-sensitive
adhesives (PSAs) listed in Table 1, by blending with dispersions of
tackifier resin. The number here indicates the parts by weight of
tackifier relative to 100 parts by weight of polymer 1 (based in
each case on solids).
TABLE-US-00004 TABLE 1 Adhesive formulations from polymer 1
Softening Inventive Comparative point examples examples Tackifier
type .degree. C. B1 B2 B3 V1 V2 V3 Rosin ester resin 99 45 10
Snowtack 100G, Lawter Rosin ester resin 83 40 Snowtack 780 G,
Lawter Rosin acid resin 69 40 Snowtack 781A*, Lawter Terpene
phenolic resin 96 35 Dermulsene TR 602, DRT *Former designation:
Snowtack SE 380.
[0183] Serving as Inventive examples B4 and B5 are polymers 2 and
3, in each case blended with 40 parts by weight of the rosin ester
resin Snowtack 100G with a softening point of 99.degree. C.
[0184] Counter-example V4 is the acrylate dispersion Primal PS 83 D
from the manufacturer Dow Chemical Company, blended with 8 parts by
weight of Snowtack 781A, with the former designation Snowtack SE
380. This example relates to Inventive example 1 of DE 44 19 169
A1.
[0185] The bond strengths to steel of Inventive examples B1 to B5
and also of Counter-examples V1 to V4 were measured as follows
(figure in N/cm):
TABLE-US-00005 B1 B2 B3 B4 B5 V1 V2 V3 V4 4.6 4.3 3.9 3.8 3.4 2.2
1.9 1.8 2.1
[0186] The glass transition temperatures of the pressure-sensitive
adhesive formulations of Inventive examples B1 to B5 and also of
Counter-examples V1 to V4 were measured as follows (figure in
.degree. C.):
TABLE-US-00006 B1 B2 B3 B4 B5 V1 V2 V3 V4 -26 -29 -33 -25 -16 -32
-39 -47 -37
[0187] Table 3 sets out the test results for the example
specimens:
TABLE-US-00007 TABLE 3 Inventive Comparative examples examples B1
B2 B3 B4 B5 V1 V2 V3 V4 Unwind force 1 1 1 1 1 1 1 1 1 Flagging 3 2
3 1 2 0 0 0 0 resistance Cable 1 1 1 1 1 1 1 1 1 compatibility
[0188] All three test criteria are vital for an
application-compatible adhesive tape for cable jacketing. The
inventive examples therefore show adhesive tapes which conform to
the concept of the invention; the comparative examples, in
contrast, are unsuitable.
* * * * *