Copolymers and blends which are self-curable under the action of atmospheric humidity

Information

  • Patent Grant
  • 5532321
  • Patent Number
    5,532,321
  • Date Filed
    Friday, May 6, 1994
    30 years ago
  • Date Issued
    Tuesday, July 2, 1996
    28 years ago
Abstract
Essentially isocyanate-free, ketimine- and aldimine-free, one-component sealing, adhesive or coating materials which are self-curable under the action of atmospheric humidity containing a copolymer A composed of50-99.8% by weight of a C.sub.1 -C.sub.16 -alkyl (meth)acrylate or vinyl ester of carboxylic acids of 1 to 20 carbon atoms a),0.1-20% by weight of an unsaturated carboxylic anhydride b),0.1-10% by weight of an Si-containing compound c) capable of undergoing hydrolysis and0-40% by weight of a further, copolymerizable unsaturated compound d)or containing a mixture of copolymers comprising5-95% by weight, based on the mixture, of a copolymer B), composed of50-99.9% by weight of a C.sub.1 -C.sub.16 -alkyl (meth)acrylate or vinyl ester of carboxylic acids of 1 to 20 carbon atoms a),0-20% by weight of an unsaturated carboxylic anhydride b)0.1-10% by weight of an Si-containing compound c) capable of undergoing hydrolysis and0-40% by weight of a further, copolymerizable unsaturated compound d)and5-95% by weight, based on the mixture, of a copolymer C) composed of50-99.9% by weight of a C.sub.1 -C.sub.16 -alkyl (meth)acrylate or vinyl ester of carboxylic acids of 1 to 20 carbon atoms a),0.1-20% by weight of an unsaturated carboxylic anhydride b),0-10% by weight of an Si-containing compound c) capable of undergoing hydrolysis and0-40% by weight of a further, copolymerizable unsaturated compound d),the K value of one of the copolymers B) or C) being from 12 to 40 and that of the other copolymer being from 30 to 70 and the K values of the two copolymers differing by at least 5K value units, where the K value is measured according to DIN 53,726.
Description

The present invention relates to essentially isocyanate-free, kerimine-free and aldimine-free, one-component sealing, adhesive or coating materials which are self-curable under the action of atmospheric humidity, containing a copolymer A composed of
50-99.8% by weight of a C.sub.1 -C.sub.16 -alkyl (meth)acrylate or vinyl ester of carboxylic acids of 1 to 20 carbon atoms a),
0.1-20% by weight of an unsaturated carboxylic anhydride b),
0.1-10% by weight of an Si-containing compound c) capable of undergoing hydrolysis and
0-40% by weight of a further, copolymerizable unsaturated compound d)
or containing a mixture of copolymers comprising
5-95% by weight, based on the mixture, of a copolymer B), composed of
50-99.9% by weight of a C.sub.1 -C.sub.16 -alkyl (meth)acrylate of a C.sub.1 -C.sub.16 -alkyl (meth)acrylate or vinyl ester of carboxylic acids of 1 to 20 carbon atoms a),
0-20% by weight of an unsaturated carboxylic anhydride b) 0.1-10% by weight of an Si-containing compound c) capable of undergoing hydrolysis and
0-40% by weight of a further, copolymerizable unsaturated compound d)
and
5-95% by weight, based on the mixture, of a copolymer C) composed of
50-99.9% by weight of a C.sub.1 -C.sub.16 -alkyl (meth)acrylate or vinyl ester of carboxylic acids of 1 to 20 carbon atoms a),
0.1-20% by weight of an unsaturated carboxylic anhydride b),
0-10% by weight of an Si-containing compound c) capable of undergoing hydrolysis and
0-40% by weight of a further, copolymerizable unsaturated compound d),
the K value of one of the copolymers B) or C) being from 12 to 40 and that of the other copolymer being from 30 to 70 and the K values of the two copolymers differing by at least 5K value units, where the K value is measured according to DIN 53,726.
Related to the ISO Standard ISO 174-1974 issued by the International Organization for Standardization (ISO), see notes.
1 Purpose and scope
The procedure according to this standard serves for determining the viscosity number and/or the K-value of VC polymers at 25.degree. C. in a solution containing 0.5 g of VC polymer per 100 cm.sup.3 of solution. The solvent used is cyclohexanone. The viscosity number or the K-value are parameters for characterizing the degree of polymerization of a VC polymer.
The procedure can be applied to all vinyl chloride homopolymers and those vinyl chloride copolymers which dissolve in cyclohexanone under the conditions specified in section 6.2. If the polymer to be tested contains additions which affect the measurement of the viscosity, special test procedures are to be agreed.
2 Terms
2.1 Viscosity number.sup.1
The viscosity number J is the relative change in viscosity, based on the concentration by mass .beta. of the VC polymer in the solution,
.sup.1 See also DIN 1342 ##EQU1## The symbols in the formula have the following meanings: J Viscosity number in cm.sup.3 /g
.eta. Dynamic viscosity of the solution
.eta..sub.0 Dynamic viscosity of the solvent
.beta. Concentration by mass of VC polymer in the solution, in g/cm.sup.3,
Note: DIN 1310 (in draft format present) specifies the formula symbol .beta. for the concentration by mass, in this case in g/cm.sup.3.
2.2 K-value
The K-value is defined by the following numerical-value equations: K-value=1000 k. k is calculated, according to H. Fikentscher, as follows: ##EQU2## The symbols in these equations have the following meanings: ##EQU3## .beta. and .eta..sub.0, .eta. see section 2.1. 3 Name of the procedure ##STR1## 4 Sampling
A sample is taken from the VC polymer to be tested. Any pretreatment of the sample is to be agreed and to be specified in the test report.
5 Test equipment and test media
5.1 Test equipment
Ubbelohde viscometer No. I according to DIN 51562 Part 1 or any other capillary viscometer with which identical results can be achieved.
Stopwatch having a scale interval of 0.1 s.
Balance having a scale interval of 0.1 mg,
50 ml volumetric flask with ring mark, conical ground joint and glass stopper, e.g. in accordance with DIN 12664, Part 1,
Heatable magnetic stirrer appliance with continuously variable heating output. The magnetic stirrer rod having a length of approximately 30 mm and a diameter of approximately 7 nun must be coated with polytetrafluoroethylene (PTFE).
Horseshoe magnet for removing the magnetic stirrer rod from the 50 ml volumetric flask.
400 ml glass beaker, e.g. in accordance with DIN 12332.
Transparent waterbath thermostat for a temperature of (25.+-.0.05).degree.C.
Glass filter crucible having a maximum nominal pore width of from 40 to 100 .mu.m or
glass funnel with filter paper, e.g. for chemical analyses of grade i a in accordance with DIN 53135.
500 ml glass wash bottle with standard ground joint. Standards Committee Plastics (FNK) in DIN "Deutsches Institut fur Normung e.V." Standards Committee Materials Testing (NMP) in DIN
Page 2 DIN 53726
5.2 Test media
Solvents:
Cyclohexanone, chemically pure. Distilled fraction at a temperature between 155.degree. and 156.degree. C. and a pressure of 1013 mbar. The solvent is stored in the dark for at most 2 weeks, before the test is carried out, in a brown glass bottle with ground stopper.
Kinematic viscosity of cyclohexanone at 25.degree. C.=from 2.06 to 2.14 mm.sup.2 /s.
Cleaning media:
Sulfuric acid, mass fraction between 95 and 97 %
Aqueous potassium dichromate solution, saturated
Acetone, chemically pure Heating bath fluid: diethylene glycol
6 Procedure
6.1 Cleaning of the viscometer
Before being used for the first time, and subsequently from time to time, the viscometer is cleaned with a mixture (chromic-sulfuric acid) of equal parts by volume of sulfuric acid and potassium dichromate solution. It is then rinsed successively with distilled water and acetone, and is dried by dry, dust-free air being blown through.
Between two successive tests, the viscometer is merely rinsed with acetone, or at least twice with the solution newly to be measured. If cleaning is carried out with acetone, drying as described is mandatory. The last solution of the test series must, in every instance, be flushed from the viscometer using acetone, so as to avoid the formation of a polymer film on the inner walls.
6.2 Preparing the solution
A sample of (250.+-.5) mg of the VC polymer to be tested is weighed to an accuracy of 0.2 mg and is transferred quantitatively into the 50 ml volumetric flask. Then, about 40 ml of the solvent are added, the volumetric flask being agitated at the same time to prevent the formation of lumps. After the magnetic stirrer rod has been carefully placed into the volumetric flask, the latter is placed into the 400 ml beaker half filled with diethylene glycol. Then the magnetic stirring appliance is switched on, and the beaker is placed on its hotplate. The heating output of the hotplate should be set in such a way that the heating bath fluid reaches a stable temperature of approximately 85.degree. C. The volumetric flask is left in the beaker until the sample has dissolved completely (experience shows that this takes one hour). Then the solution is cooled to 20.degree. C. in the waterbath thermostat. By means of the horseshoe magnet guided from outside along the flask wall, the magnetic stirrer rod is pulled up as far as the neck of the flask, is rinsed with solvent by means of the wash bottle and is then taken from the neck of the volumetric flask.
Then the flask is topped up with the solvent of 20.degree. C. as far as the mark, is closed and agitated for 1 min.
Instead of this procedure, the solution can also be prepared--without use of a magnetic stirring appliance--in an oven at a temperature between 80.degree. and 90.degree. C., with occasional agitation. This dissolution process is more time-consuming, however.
6.3 Measurement of the efflux times of the solution and the solvent
The solution and solvent are each filtered through the glass filter crucible. Instead of the glass filter crucible it is also possible to use a glass funnel and
c) Viscometer employed
d) Viscosity number, rounded to integers and/or
e) K-value, rounded to one decimal after the point
f) Any agreed conditions deviating from the present standard
g) Test date.
TABLE A1__________________________________________________________________________Comparison values between the viscosity number and the K-value Viscosity number/ Viscosity number/ Viscosity number/ in in int/t.sub.o cm.sup.3 /g K-value t/t.sub.o cm.sup.3 /g K-value t/t.sub.o cm.sup.3 /g K-value__________________________________________________________________________1.195 39 39.7 1.520 104 64.7 1.845 169 79.91.200 40 40.3 1.525 105 64.9 1.850 170 80.11.205 41 40.8 1.530 106 65.2 1.855 171 80.31.210 42 41.3 1.535 107 65.5 1.860 172 80.51.215 43 41.8 1.540 108 65.8 1.865 173 80.71.220 44 42.3 1.545 109 66.1 1.870 174 80.91.225 45 42.9 1.550 110 66.3 1.875 175 81.11.230 46 43.3 1.555 111 66.6 1.880 176 81.31.235 47 43.8 1.560 112 66.9 1.885 177 81.51.240 48 44.3 1.565 113 67.1 1.890 178 81.71.245 49 44.8 1.570 114 67.4 1.895 179 81.81.250 50 45.3 1.575 115 67.7 1.900 180 82.01.255 51 45.7 1.580 116 67.9 1.905 181 82.21.260 52 46.2 1.585 117 68.2 1.910 182 82.41.265 53 46.6 1.590 118 68.5 1.915 183 82.61.270 54 47.1 1.595 119 68.7 1.920 184 82.81.275 55 47.5 1.600 120 69.0 1.925 185 83.01.280 58 48.0 1.605 121 69.2 1.930 188 83.11.285 57 48.4 1.610 122 69.5 1.935 187 83.31.290 58 48.8 1.615 123 69.7 1.940 188 83.51.295 59 49.2 1.620 124 70.0 1.945 189 83.71.300 60 49.6 1.625 125 70.2 1.950 190 83.91.305 61 50.1 1.630 126 70.5 1.955 191 84.01.310 62 50.5 1.635 127 70.7 1.960 192 84.21.315 63 50.9 1.640 128 71.0 1.965 193 84.41.320 64 51.3 1.645 129 71.2 1.970 194 84.61.325 65 51.7 1.650 130 71.5 1.975 195 84.71.330 66 52.1 1.655 131 71.7 1.980 196 84.91.335 67 52.4 1.660 132 71.9 1.985 197 85.11.340 68 52.8 1.665 133 72.2 1.990 198 85.31.345 69 53.2 1.670 134 72.4 1.995 199 85.41.350 70 53.6 1.675 135 72.6 2.000 200 85.61.355 71 54.0 1.680 136 72.9 2.005 201 85.81.360 72 54.3 1.685 137 73.1 2.010 202 85.91.365 73 54.7 1.690 138 73.3 2.015 203 86.11.370 74 55.1 1.695 139 73.6 2.020 204 86.31.375 75 55.4 1.700 140 73.8 2.025 205 86.51.380 76 55.8 1.705 141 74.0 2.030 206 86.61.385 77 56.1 1.710 141 74.3 2.035 207 86.81.390 78 56.5 1.715 143 74.5 2.040 208 87.01.395 79 56.8 1.720 144 74.7 2.045 209 87.11.400 80 57.2 1.725 145 74.9 2.050 210 87.31.405 81 57.5 1.730 146 75.1 2.055 211 87.41.410 82 57.9 1.735 147 75.4 2.060 212 87.61.415 83 58.2 1.740 148 75.6 2.065 213 87.81.420 84 58.5 1.745 149 75.8 2.070 214 87.91.425 85 58.9 1.750 150 76.0 2.075 215 88.11.430 86 59.2 1.755 151 76.2 2.080 216 88.31.435 87 59.5 1.760 152 76.5 2.085 217 88.41.440 88 59.8 1.765 153 76.7 2.090 218 88.61.445 89 60.1 1.770 154 76.9 2.095 219 88.71.450 90 60.5 1.775 155 77.1 2.100 220 88.91.455 91 60.8 1.780 156 77.3 2.105 221 89.01.460 92 61.1 1.785 157 77.5 2.110 222 89.21.465 93 61.4 1.790 158 77.7 2.115 223 89.41.470 94 61.7 1.795 159 77.9 2.120 224 89.51.475 95 62.0 1.800 160 78.1 2.125 225 89.71.480 96 62.3 1.805 161 78.3 2.130 226 89.81.485 97 62.6 1.810 162 78.5 2.135 227 90.01.490 98 62.9 1.815 163 78.7 2.140 228 90.11.495 99 63.2 1.820 164 78.9 2.145 229 90.31.500 100 63.5 1.825 165 79.1 2.150 230 90.41.505 101 63.8 1.830 166 79.3 2.155 231 90.61.510 102 64.1 1.835 167 79.5 2.160 232 90.71.515 103 64.4 1.840 168 79.7 2.165 233 90.9 2.170 234 91.0__________________________________________________________________________
Standards quoted
______________________________________DIN 1310 (in draft form at present) Composi- tion of mixed phases (gas mixtures, solutions, mixed crystals); terms, symbolsDIN 1342 Viscosity of Newtonian fluidsDIN 12332 Glass laboratory equipment; beakers, low shapeDIN 12664, Part 1 Glass laboratory equipment; volu- metric flasks with a mark, volu- metric flasks with beaded rim, coni- cal socket and taper-ground jointDIN 51562, Part 1 Viscometry; determination of the kinematic viscosity using the stan- dard-design Ubbelohde viscometerDIN 53135 Filter papers for chemical analyses; classification, designation, main properties, test procedures______________________________________
Earlier issue
DIN 53726:06.61
Updates
Compared to the issue of June 1961, the standard has been revised editorially, a few statements have been made more specific, and a better procedure has been described for preparing the solution.
Explanatory notes
The present standard has been compiled by the subcommittee 303.2 "PVC molding materials". The specifications it contains agree factually with those in the ISO Standard 174-1974 "Plastics; determination of viscosity number of PVC resin in dilute solution".
International patent classification
G 05 D 11-12
C 07 C 69-01
The present invention furthermore relates to copolymers or blends of copolymers which are self-curable under the action of atmospheric humidity.
One-component sealing materials which are self-curable under the action of atmospheric humidity are stored in closed containers, for example cartridges. They do not require the addition of a second component when used. As soon as the container is opened or the sealing material is pressed out of the cartridge, self-curable begins under the action of atmospheric humidity.
Conventional sealing materials which are curable under the action of atmospheric humidity contain a wide range of isocyanate compounds as crosslinking agents. According to DE-A 39 13 168, isocyanates may be polymerized in polymers. DE-A 40 38 939 discloses, as sealing materials, mixtures of diisocyanates or aldimines or kerimines with copolymers which contain bound, hydrolyzed Si compounds as regulators.
The disadvantages of sealing materials which cure under the action of atmospheric humidity and contain isocyanate compounds are the yellowing observed and in particular the formation of carbon dioxide during curing. The mechanical properties of the cured sealing materials are adversely affected by included gas. Furthermore, the evolution of gas rules out applications where there should be no increase in volume.
Further copolymers which contain hydrolyzable Si compounds and are used in sealing or coating materials are disclosed in DE-A 39 07 991, DE-A 34 26 057 and EP-A-122 457.
In general, sealing or coating materials which have high tensile strength and good elasticity after stress application, for example elongation, and do not tend to yellow and in which no gas evolution occurs are desirable.
It is an object of the present invention to provide such materials.
We have found that this object is achieved by the materials defined above.
The sealing, adhesive or coating materials contain a copolymer A or a mixture of copolymers B) and C).
The copolymers contain, as components, C.sub.1 -C.sub.16 -alkyl (meth)acrylates a), unsaturated carboxylic anhydrides b), an Si-containing compound c) capable of undergoing hydrolysis and further polymerizable, unsaturated compounds d).
Preferred compounds a) are C.sub.1 -C.sub.16 -alkyl (meth)acrylates, particularly preferably C.sub.1 -C.sub.8 -alkyl (meth)acrylates, such as methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate and 2-ethylhexyl (meth)acrylate. In addition to the C.sub.1 -C.sub.16 -alkyl (meth)acrylates, other suitable compounds a) are vinyl esters of carboxylic acids of 1 to 20 carbon atoms, such as vinyl laurate, vinyl stearate, vinyl propionate and in particular vinyl acetate, as well as mixtures thereof with C.sub.1 -C.sub.16 -alkyl (meth)acrylates.
Unsaturated carboxylic anhydrides b) are preferably of 4 to 8, particularly preferably 4 or 5, carbon atoms. Examples are maleic anhydride, itaconic anhydride, citraconic dianhydride and cyclohexenedicarboxylic anhydride.
The Si-containing compounds capable of undergoing hydrolysis are preferably compounds of the general formula I ##STR2## or mixtures thereof, where R.sup.1 and Z are each C.sub.1 -C.sub.18 -alkyl, preferably C.sub.1 -C.sub.6 -alkyl, or phenyl, R.sup.2 is C.sub.1 -C.sub.18 -alkylene, preferably C.sub.1 -C.sub.6 -alkylene, cyclohexylene or phenylene, X is a group capable of undergoing free radical polymerization and n is 0, 1 or 2. X is preferably a (meth)acrylate, (meth)acrylamide or vinyl radical.
Examples are 3-acryloyloxypropyltriethoxysilane, 3-methacryloyloxypropylmethyldiethoxysilane, 3-methacryloyl-oxypropyldimethylethoxysilane, 3-methacryloyloxy-propyltris(2-methoxyethoxy)silane, vinyltrimethoxysilane, vinyltris(methoxyethoxy)silane and in particular (meth)acryloyloxypropyltrimethoxysilane (MEMO), 3-mercapto-propyltrimethoxysilane and 3-mercaptopropyltriethoxysilane.
Compounds of the formula I are incorporated as monomers by copolymerization with the group X.
Compounds of the formula II are incorporated as regulators in the form of terminal groups in the polymer chain and, owing to their regulating effect, reduce the molecular weight and hence also the K value.
Compounds d) are vinylaromatic compounds, such as vinyltoluene, .alpha.- and p-methylstyrene, .alpha.-butylstyrene, 4-n-butylstyrene, 4-n-decylstyrene and preferably styrene, vinyl halides, preferably vinyl chloride and vinylidene chloride, and nonaromatic hydrocarbons having 2 to 8 carbon atoms and at least two olefinic double bonds, such as butadiene, isoprene and chloroprene, as well as C.sub.2 -C.sub.4 -olefins, e.g. ethylene.
Copolymer A is preferably composed of
70-99% by weight of a),
0.1-12% by weight of b),
0.1-8% by weight of c) and
0-25% by weight of d).
The K value of the copolymer A is preferably from 20 to 60.
The K value is a relative viscosity number which is determined according to DIN 53,726 at 25.degree. C. It indicates the flow rate of a mixture of 0.01 g of polymer in 1 ml of tetrahydrofuran (THF) relative to the flow rate of pure THF and characterizes the average degree of polymerization of the polymers.
The glass transition temperature T.sub.g of the copolymer A) is preferably from -70.degree. to +20.degree. C., particularly preferably from -50.degree. to +20.degree. C., very preferably from -40.degree. to -10.degree. C. Above the T.sub.g, the polymer is liquid.
The glass transition temperature of the copolymer can be determined by conventional methods, such as differential thermal analysis or differential scanning calorimetry (cf. for example ASTM 3418/82, midpoint temperature).
A preferred mixture, containing copolymers B) and C), contains from 20 to 80% by weight of copolymer B) and from 20 to 80% by weight of copolymer C).
Copolymer B) is preferably composed of from 70 to 99.9% by weight of a),
0-10% by weight of b),
0.1-8% by weight of c) and
0-25% by weight of d).
Copolymer C) is preferably composed of
0-99% by weight of a),
0.1-12% by weight of b),
0-6% by weight of c) and
0-25% by weight of d).
Copolyer B) very particularly preferably contains essentially no compound b) and copolymer C) essentially no compound c).
One of the two copolymers B) or C) has a higher molecular weight, characterized by a K value of 30 to 70, preferably from 35 to 55, and the other copolymer has a K value of from 12 to 40, preferably from 15 to 30.
Very particularly preferably, copolymer C) has the higher K value.
The K values of the two copolymers differ by at least 5, preferably by at least 15K value units.
The above statements (for copolymer A) are applicable to the glass transition temperature of copolymers B) and C).
Compounds of the formula I or II or mixtures thereof may be used as compound c) in the copolymers A), B) and C).
Copolymers having a K value of 30 or higher preferably contain copolymerizable Si compounds of the formula I.
Copolymers having a K value of less than 30 preferably contain regulatory Si compounds of the formula II or mixtures of Si compounds of the formulae I and II with at least 10, preferably at least 40, % by weight of the compounds II, the percentages being based on the total content of the compounds c).
The copolymers are prepared by free radical polymerization, for example by mass polymerization (in the absence of solvent) or preferably solution polymerization, in general at from 20.degree. to 120.degree. C., preferably from 80.degree. to 120.degree. C.
The solution polymerization can be carried out as a batch process or in the form of a feed process. The feed process in which some of the polymerization batch is initially taken and heated to the polymerization temperature and the remainder is then fed in continuously is preferred.
As a rule, ethers, such as tetrahydrofuran or dioxane, esters, such as ethyl acetate or n-butyl acetate, ketones, such as acetone or cyclohexanone, N,N-dialkylcarboxamides, such as N,N-dimethylformamide, N,N-dimethylacetamide or N-methyl-2-pyrrolidone, aromatics, such as toluene and xylene, aliphatic hydrocarbons, such as isooctane, chlorohydrocarbons, such as tert-butyl chloride, or plasticizers, such as di-n-butyl phthalate, are used as solvents for the free radical solution polymerization.
The reaction is advantageously carried out in an anhydrous polymerization medium, ie. at a water content of less than 100 ppm. The solution polymerization of the essentially anhydrous reactants is advantageously carried out in the presence of small amounts of drying agents, such as tetraalkoxysilanes, e.g. tetramethoxysilane, or trialkyl orthoformates, e.g. triethyl orthoformate, with or without the addition of a Lewis acid. The solvent can, if required, be partially or completely separated off from the resulting solutions of the copolymers, for example by distillation under reduced pressure.
Preferred initiators are dibenzoyl peroxide, tert-butyl perpivalate, tert-butyl per-2-ethylhexanoate, di-tert-butyl peroxide, tert-butyl hydroperoxide, cumyl hydroperoxide, dilauryl peroxide, tert-butyl peroxymaleate, tert-butyl peroxybenzoate, dicumyl peroxide, didecanoyl peroxide, methyl ethyl ketone peroxide, 2,2'-azobis-(2,4-dimethylvaleronitrile), 2,2'-azobis-(2,3-dimethylbutyronitrile) and 2,2'-azobisisobutyronitrile. Azo initiators containing silane groups are also suitable (EP-A 159 710).
Copolymer A) or the mixture containing copolymer B) and C) is preferably used as sealing, adhesive or coating material.
Sealing, adhesive and coating materials which contain, as a polymer base, copolymer A) or a mixture of copolymer B) and C) are preferably essentially free of isocyanate compounds, kerimines or aldimines, as stated in, for example, DE-A 40 38 939.
The sealing, adhesive and coating materials are preferably one-component materials, ie. no additives are required for curing. Curing is effected only by the action of atmospheric humidity. In order to accelerate the curing, however, catalysts, in particular dialkyltin dicarboxylates, e.g. dibutyltin dilaurate, may be added to the materials in small amounts, in general in amounts of 0.05-2.0% by weight, based on the polymer material. The materials may contain further conventional additives.
The materials preferably contain no solvent or only residual amounts of solvent from the preparation copolymers, in amounts of less then 5, preferably less than 1, % by weight, based on the materials.
As in the case of the preparation of the individual copolymers, when the components of the sealing, adhesive and coating materials are mixed it is necessary to ensure that moisture is absent. The sealing, adhesive and coating materials are preferably stored in a sealed container, for example a cartridge.
The novel sealing, adhesive end coating materials cure rapidly under the action of atmospheric humidity.
In the absence of moisture, the materials generally have a shelf life of more then 6 months.
The materials are processed in the liquid state, in particular at from 10.degree. to 100.degree. C. They ten be applied or pressed into cavities, after which curing occurs under the action of atmospheric humidity.
Examples of suitable substrates which are treated as materials are those consisting of plastic, metal, concrete, ceramic or wood.
Owing to their high elasticity in the cured state, the materials are used in particular for bridging cracks in the substrate or filling expansion joints. Novel materials based on copolymers having a glass transition temperature of from -10.degree. to -40.degree. C. are preferably used outdoors.
The novel sealing materials exhibit particularly good adhesion to glass, aluminum and ceramic. They can also be overcoated.
Included gas, which presents problems in the case of isocyanate-containing sealing materials are avoided in the present invention. The novel materials are therefore suitable for use as transparent sealing materials.
In the cured state, the novel materials have a very good tensile strength and elongation at break.





EXAMPLES
Abbreviations
BA: n-Butyl acrylate
MAA: Maleic anhydride
MEMO: Methacryloyloxypropyltrimethoxysilane
MTMO: Mercaptotrimethoxysilane
DBTL: Dibutyltin dilaurate
Preparation of the copolymers
Copolymer E1
Feed 1:
770 g of BA
80 g of MAA
Feed 2:
130 g of BA
20 g of MEMO
Feed 3:
30 g of tert-butyl peroctoate
130 g of toluene
An initially taken mixture consisting of a solution of 10% by weight of monomer feed I and 10% by weight of an initiator feed 3 and 550 g of toluene was brought to an internal reactor temperature of 95.degree. C. under an inert gas atmosphere and prepolymerized for 10 min. Thereafter, three feeds were started, monomer feed 1, consisting of the acrylate monomers and unsaturated anhydrides being added in the course of 3 hours, monomer feed II, consisting of acrylate monomers and the silane compounds, in the course of 1 hour and initiator feed III, consisting of 30 g of tert -butyl peroctoate and 130 g of toluene, in the course of 4 hours. After the end of the feeds, polymerization was completed in the course of 3 hours at 95.degree. C. and the solvent and residual volatile components were distilled off under reduced pressure.
In the case of mixtures with the accelerator DBTL or further copolymers, removal of the solvent by distillation was carried out after the mixing.
The further copolymers were prepared as described above (for composition, cf. Table 1).
TABLE 1______________________________________Composition of the copolymersCopoly- Monomer Si monomer Si regulator Kmer % by weight % by weight % by weight value______________________________________V1* 98 BA 2 MEMO -- 31E1** 90 Ba, 8 MAA 2 MEMO -- 30.5E2 88 BA, 8 MAA 2 MEMO 2 MTMO 21.9E3 88 BA, 8 MMA 2 MEMO 2 MTMO 21.9E4 88 BA, 8 MAA 2 MEMO 2 MTMO 21.9E5 88 BA, 8 MAA 2 MEMO 2 MTMO 21.9E6 92 BA, 4 MAA 2 MEMO 2 MTMO 28.7A1*** 92 BA, 8 MAA -- 37.0______________________________________ *For comparison **According to the invention ***For mixtures (see below)
Testing of perfrmance characteristics
The copolymers Vl and El-E6 and copolymer blends in a weight ratio of 1:1 and 2:1 were tested for their suitability as sealing materials.
To determine the elongation at break and tensile strength, 1 mm thick films were produced from the self-curable copolymers and blends by application to silicone paper which had been stored for 6 months under standard conditions of temperature and humidity (23.degree. C., 50% atmospheric humidity). Test specimens were then punched from the films, after which the elongation at break and tensile strength were measured according to DIN 53,504 at an advance rate of 100 mm/min.
TABLE 2______________________________________Copolymer Addition of Tensile Elongation ator DBTL strength breakblend % by weight* N/mm.sup.2 %______________________________________V1 -- 0.092 147E1 -- 0.198 177E2 -- 0.153 187E3 0.2 0.186 171E4 0.6 0.192 164E5 0.8 0.199 162E6 -- 0.142 191E2/A1 (1:1) 0.2 0.356 323E2/A1 (2:1) 0.2 0.486 363______________________________________ *Based on copolymer or blend
Claims
  • 1. An essentially isocyanate-free, ketimine-free and aldimine-free, one-component sealing, adhesive or coating material which is self-curable under atmospheric humidity, comprising a copolymer A formed by copolymerizing a monomer mixture, comprising:
  • (a) 50-99.8% by weight of a C.sub.1-16 -alkyl (meth)acrylate or a vinyl ester of a C.sub.1-20 carboxylic acid;
  • (b) 0.1-20% by weight of an unsaturated carboxylic anhydride;
  • (c) 0.1-10% by weight of a Si-containing compound capable of undergoing hydrolysis; and
  • (d) 0-40% by weight of a further, copolymerizable unsaturated compound, or
  • comprising a mixture of copolymers comprising:
  • - 95% by weight, based on the mixture, of a copolymer B formed by copolymerizing a monomer mixture, comprising:
  • (a) 50-99.9% by weight of a C.sub.1-16 -alkyl (meth)acrylate or a vinyl ester of a C.sub.1-20 carboxylic acid;
  • (b) 0-20% by weight of an unsaturated carboxylic anhydride;
  • (c) 0.1-10% by weight of a Si-containing compound capable of undergoing hydrolysis; and
  • (d) 0-40% by weight of a further, copolymerizable unsaturated compound, and
  • 5-95% by weight, based on the mixture, of a copolymer C formed by copolymerizing a monomer mixture, comprising:
  • (a) 50-99.9% by weight of a C.sub.1-16 -alkyl (meth)acrylate or a vinyl ester of a C.sub.1-20 carboxylic acid;
  • (b) 0.1-20% by weight of an unsaturated carboxylic anhydride;
  • (c) 0-10% by weight of a Si-containing compound capable of undergoing hydrolysis; and
  • (d) 0-40% by weight of a further, copolymerizable unsaturated compound,
  • wherein the K value of one of the copolymers B or C is from 12 to 40 and that of the other copolymer is from 30 to 70, and wherein the K values of the two copolymers differ by at least 5K value units, where the K value is measured according to DIN 53,726.
  • 2. A copolymer blend which is self-curable under atmospheric humidity comprising, based in each case on the blend,
  • 5-95% by weight of copolymer B formed by copolymerizing a monomer mixture, comprising:
  • (a) 50-99.9% by weight of a C.sub.1-16 -alkyl (meth)acrylate or a vinyl ester of a C.sub.1-20 carboxylic acid;
  • (b) 0-20% by weight of an unsaturated carboxylic anhydride;
  • (c) 0.1-10% by weight of a Si-containing compound capable of undergoing hydrolysis; and
  • (d) 0-40% by weight of a further, copolymerizable unsaturated compound and
  • 5-95% by weight of copolymer C formed by copolymerizing a monomer mixture, comprising:
  • (a) 50-99.9% by weight of a C.sub.1-16 -alkyl (meth)acrylate or a vinyl ester of a C.sub.1-20 carboxylic acid;
  • (b) 0.1-20% by weight of an unsaturated carboxylic anhydride;
  • (c) 0-10% by weight of a Si-containing compound capable of undergoing hydrolysis; and
  • (d) 0-40% by weight of a further, copolymerizable unsaturated compound,
  • wherein the K value of one of the copolymers B or C is from 12 to 40 and that of the other copolymer is from 30 to 70, and wherein the K values of the two copolymers differ by at least 5K value units, where the K value is measured according to DIN 53,726.
  • 3. The sealing, adhesive or coating material as claimed in claim 1, wherein c) is a compound of the formula ##STR3## or mixtures thereof, where R.sup.1 and Z are each C.sub.1 -C.sub.18 -alkyl or phenyl, R.sup.2 is C.sub.1 -C.sub.18 -alkylene, cyclohexylene or phenylene, X is a group capable of undergoing free radical copolymerization and n is 0, 1 or 2.
  • 4. A copolymer A) which is self-curable under the action of atmospheric humidity, as claimed in claim 1, containing a compound of the formula I: ##STR4## as the Si-containing compound C), where R.sup.1 and Z are each C.sub.1-18 -alkyl or phenyl, R.sup.2 is C.sub.1-18 -alkylene cyclohexylene or phenylene, X is a group capable of undergoing free radical copolymerization and n is 0, 1 or 2.
  • 5. A sealing, adhesive or coating material as claimed in claim 1, additionally containing a dialkyltin dicarboxylate for accelerating the self-curable by the action of atmospheric humidity.
  • 6. A method of using the material containing a mixture of copolymers B) and C), as claimed in claim 2, as a sealing, adhesive or coating material which is self-curable under the action of atmospheric humidity.
  • 7. A method of using the material containing a copolymer A, as claimed in claim 4, as a sealing, adhesive or coating material which is self-curable under the action of atmospheric humidity.
  • 8. The sealing, adhesive or coating material according to claim 1, wherein the K value of said copolymer A is from 20 to 60, where the K value is measured according to DIN 53,726.
Priority Claims (1)
Number Date Country Kind
43 15 880.3 May 1993 DEX
US Referenced Citations (6)
Number Name Date Kind
4368297 Kato et al. Jan 1983
4468492 Piccirilli et al. Aug 1984
4518726 Kato et al. May 1985
4543403 Isayama et al. Sep 1985
4818790 Ooka et al. Apr 1989
5063114 Nambu et al. Nov 1991
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