|Title of Invention||
ADHESIVE AQUEOUS DISPERSION FOR THE TREATMENT OF REINFORCEMENT INLAYS
|Abstract||Adhesive aqueous dispersion for the treatment of reinforcement inlays for the production of reinforced polymer products in the form of an aqueous dispersion, containing an adhesive as a solid (A5) wherein the adhesive is isocyanate, partly or completely blocked isocyanate and additives, characterized in that the aqueous dispersion has a solids fraction of 55-85 wt%, provided that the average diameter of the solids is <2.0 μm and wherein 80% of the solid have a particle diameter of 0.01-5 μm , preferably 0.5-5 μm|
|Full Text||FORM 2
THE PATENTS ACT 1970
[39 OF 1970]
THE PATENTS RULES, 2003
[See Section 10; rule 13]
"ADHESIVE AQUEOUS DISPERSION FOR THE TREATMENT OF REINFORCEMENT INLAYS"
EMS-CHEMIE AG, of Reichenauerstrasse, CH-7013 DOMAT/EMS, Switzerland,
The following specification particularly describes the invention and the
manner in which it is to be performed: GRANTED
8 AUG 2005
The present invention relates to an adhesive aqueous dispersion for the treatment of reinforcement inlays.
The invention concerns an adhesive for the treatment of textile reinforcement inlays of the production of textile-reinforced rubber products in particular for a tire cord that is present in the form of an aqueous dispersion with a solids fraction of blocked isocyanate of 55-80
In the production of fiber-reinforced rubber products, it has proved advantageous if an adhesive is used for the improvement of the adhesive strength between textile reinforcement inlays and the rubber. The use of such an adhesive, in particular in the area of the cords and other high-stress composite materials with reinforcement fibers, is important. Especially for these fields of application, the use of resorcinol-formaldehyde-latex system (RFL) for the bonding of synthetic fibers to rubber products is known from the state of the art. In accordance with the method, the procedure can be carried out in a one-step or in a two-step method. IN the one-step method, an impregnation of the reinforcement element with a mixture of RFL and all adhesive is carried out.
In the two-step method, an impregnation of the reinforcement element is undertaken first with the adhesive and then the application of RFL is carried out in a second step.
Prom the state of the art, specially coordinated adhesives are also already known for sich methods. These systems are based on a special formulation of an aqueous dispersion of blocked isocyanates in combination with RFL. In an overview article from "Rubber Chemistry and Technology," Vol. 58; p. 383-391, the corresponding adhesive systems and the methods for the production of fiber-reinforced rubber products are described. A special adhesive system is disclosed in US Patent No. 4,477,615'.
From "Tire Technology International," 1994, page ... to ..., an adhesive system is known, which is sold under the name Grillbond IL-6' by the EMS Chemie AG in Switzerland. This system consists of an aqueous dispersion, which contains a 50% solids fraction of a blocked isocyanate. In comparison with the powders which are also known from the state of the art, this system has in particular, the advantage that the aqueous dispersion is stable in storage and can be used immediately. This makes possible a simple handling and an economical execution of the method. At the same time, it has been shown that, in this way, neither an agglomeration nor a sedimentation of solids occurs, as is obviously the case in the preparation of powders with water.
The disadvantage with the previously described aqueous dispersion Grillbond*, however, is that the solids fraction is relatively low and that for this reason, large quantities must tic used, so as to guarantee a complete impregnation of the fibers.
Therefore, on the bisis of this, the goal of the invention under consideration is to propose an adhesive system which has an increased solids fraction, in comparison to the state of the art, and with which a complete impregnation of the fibers is possible.
With regard to the adhesive, the goal is attained by the characterizing features of Claim 1; with regard to :hc method, by the features of Claim 10; and with regard to the application, by the features of Claim 16. The subclaims indicate advantageous refinements .
Surprisingly, the applicant was able to show that it is possible to obtain an aqueous dispsrsion with a solids fraction of 55-85%, if the average particle size of the solids is
In this way, textile fiber-reiiiforced rubber products can be produced, which are clearly improved in their technical data-that is, in particailar, in adhesive strength, in comparison to the state of the art.
It is particularly preferred in the aqueous dispersion in accordance with the invention, if the average particle diameter is By experiments which were carried out by the applicant, it was possible to determine that 80% of the solids particles have a diameter of 0.01-5 μm. It is preferable, however, if the diameter is between 0.5 and 5 μm. This shows that a more uniform particle size distribution and smaller particle si2es are present in the aqueous dispersion in accordance with the invention than was the case with the state of the art. The particle size distribution varies only within very nairow limits. The dispersion in accordance with the invention accordingly contains the solids in the form of a fine or very fine comminution.
From a material point of view, the invention comprises, with regard to the adhesives, all isocyanates which, in fact, have been used up to now in the state of the art for these application cases. The invention thereby includes isocyanates and the corresponding reaction p.-oducts from the isocyanates with themselves to form dtrnerie of ollgomerio products and those with blocking agents, to form partially or completely blocked isocyanates. In general, all commercially obtained aromatic
isocyanates and aliphatic and cycloaliphatic isocyanates can be used. Special examples include the following:
Diphenylmetb.ane-4:4- arid/or -2,4-diisocyanate (MDI), raw" and purified
polymer MDL (PMDI), and. all other NIDI isomers, such us: 3,4-MDI, 2,2-MDI, and/or
2,3-MDL 2,4* and/or 2,6-toluene diisocyanate and their oligomers, in particular,
dimerized 2,4- toluene diisocyanate,
\ -Isocyanato •3-isocyanatomothyI-3,5,5,-trimethylcyclohi3xane (isophorone-diisocyanate or IPDI), hexamethyl
Accordingly there is provided an adhesive aqueous dispersion for the treatment of reinforcement inlays for the production of reinforced polymer products in the form of an aqueous dispersion, containing an adhesive as a solid (A5) wherein the adhesive is isocyanate, partly or completely blocked isocyanate and additives, characterized in that the aqueous dispersion has a solids fraction of 55-85 wt%, provided that the average diameter of the solids is Examples of blocking agents include the following:
Monopbenols, for example, phenol, resordnol, cresol, trimethyl phenols, tcrr-butylphenols, lactams, for example, g-caprolactam, 5-valerolactarrL Oximes, for example, methyl ethyl ketoxime (butanone oxime), methyl amyl ketoximc, and cyclohexanone oxime. Primary, secondary, and tertiary alcohols, glycol ethers, readily enol-forming compounds, such as acetoacetic ester, acetyl acetone, malonic acid derivatives. Secondary aromatic amines. Imides. mercaptans, and triazoles.
Wetting agents and/or dispersants are used as additives.
The adhesive in accordance with the invention is particularly suitable for textile reinforcement inlay for example, made of polyester, polyethylene, polyamide, or Ryan. The. reinforcement inlays treated in this manner are used, in particular, for the production of tire cord, conveyor belts, V-belts, mechanical rubber parts, as well as composites.
The invention also concerns a method for the production of the previously described adhesive. The production of the adhesive in accordance with the invention is earned out thereby in a two-stage process. The procedure is such that in a first step, a preliminary dispersion of the adhesive is produced with water in the form of an aqueous dispersion with, for example, 50% solids content. In the further course, this preliminary dispersion is then subjected to a wet comminution, until the total material to be commir.uted is water-thin and a viscosity of 5-150 mp, preferably 5-90 mp. The water-thin, comminuted rraterial thus produced then permits the required further addition of solids, until the desired solids content of 55-85 wt% is attained. The wet comminution is thereby preferably carried out with a stirrer-ball mill.
If necessary, a dilution, for example, to 60% can again be produced by the further addition of water once a certain solids content, for example, of 70%, has established if this should be necessary because of certain reasons for the production of very specif] c, selected rubber products.
Surprisingly, it has become evident that the adhesive system, produced as described in the preceding, has an excellent storage stability of at least one year. It was particularly surprising that with the adhesive composition in accordance with the invention., an addition of a thicKener, as is required with compositions known from the state of the art, was not necessary. The settling behavior was thereby better without an additional thickener than with the formulations known from the state of the art.
Below, the invention is explained in more detail with the aid of Figures I and 2.
Figure 1 hereby shows the particle size distribution of an aqueous dispersion IL-6 with a 50% solids fraction
Figure 2 shows the oarticle size distribution of a 70% solution with a very fine comminution.
Figure; 1 shows the particle si2e distribution of an adhesive dispersion as it has been known up to now in the state of the art. As can be seen from the particle size distribution, this adhesive aspersion has a very broad size distribution. The individual particle sizes of the adhesives vary in the range of 0.1 -.20 μm The average particle diameter of the solids thereby lies at 3.02 μm.
Figure 2 shows the same measurement results with an adhesive in accordance
with the invention. The particle size distribution essentially varies between 0.1 and 5
μm. 80% of the solids thereby have a diameter of 0.5-5 μm. The average particle
diameter of the solids is, accordingly, L32μm. In particular, these selected particle
diameters permit the realisation of an adhesive, which is as highly concentrated as
described in accordance with the invention. For a specialist, it was thereby completely surprising and not expected that this adhesive exhibits an excellent storage stability and thereby also has an adhesive strength which is clearly improved in comparison to the state of the art.
1. Adhesive aqueous dispersion for the treatment of reinforcement inlays for the production of reinforced polymer products in the form of an aqueous dispersion, containing an adhesive as a solid (A5) wherein the adhesive is isocyanate, partly or completely blocked isocyanate and additives, characterized in that the aqueous dispersion has a solids fraction of 55-85 wt%, provided that the average diameter of the solids is 2. Adhesive as claimed in claim 1, wherein the average particle diameter is 3. Adhesive as claimed in claims 1 to 2, wherein the solids fraction is 65-75 wt%.
4. Adhesive as claimed in claims 1 to 3, wherein the polymer products are rubber products.
5. Adhesive as claimed in claims 1 to 4, wherein the reinforcement inlays are textile reinforcement inlays.
6. Adhesive as claimed in claim 5, wherein the reinforcement inlays are made of polyester, polyethylene, polyamide or Ryan.
7. Adhesive as claimed in claims 1 to 3, wherein it contains wetting
agents and/or dispersing agents are additives.
8. Method for the production of an adhesive as claimed in claims 1
to 7, wherein in a first step, a dispersion of the adhesive is produced
with water in the form of an aqueous dispersion and that this
preliminary dispersion is subjected to a wet comminution in a second
step, until a viscosity of 5-150 mp is attained and then additional solids
are added until the solids fraction is 55-85 wt%.
9. Method as claimed in claim 8, wherein the dispersion is adjusted in such a manner that a solids content of a maximum of 55 wt% is attained.
10. Method as claimed in claim 8 or 9, wherein the viscosity during the wet comminution is in the range of 5-90 mp.
11. Method as claimed in claims 8 to 10, wherein the wet comminution is carried out with a stirrer ball mill.
12. Method as claimed in claims 8 to 11, wherein blocked isocyanate, in particular caprolactam-blocked diisocyanate, is used as the adhesive.
13. Method as claimed in claims 9 to 12, wherein additives; such as wetting agents and/or dispersing agents, are added to the preliminary dispersion.
14. Method for the production of an adhesive substantially as herein described with reference to the accompanying drawings.
Dated this 7th day of March, 2000.
OF REMFRY & SAGAR
ATTORNEY FOR THE APPLICANTS
|Indian Patent Application Number||194/MUM/2000|
|PG Journal Number||43/2008|
|Date of Filing||07-Mar-2000|
|Name of Patentee||EMS-CHEMIE AG|
|Applicant Address||REICHENAUERSTRASSE, CH-7013 DOMAT/EMS, SWITZERLAND.|
|PCT International Classification Number||C08J 3/00|
|PCT International Application Number||N/A|
|PCT International Filing date|