Two-component foamable silane-modified polymer composition

Abstract

The invention relates to a two-component foamable silane-modified polymer composition exhibiting permanent tackiness comprising: component A comprising (a-1) at least one silane modified polymer comprising polypropylene glycol repeating units, and (a-2) at least one chemical blowing agent selected from the group consisting of alkali metal bicarbonate, alkali metal carbonate, ammonium bicarbonate and ammonium carbonate, and component B comprising (b-1) water, and (b-2) an organic acid selected from the group consisting of acids comprising a C.sub.6-C.sub.18 aryl group, an aralkyl group, dicarboxylic acids, and tricarboxylic acids, wherein component A and/or component B comprises at least one surface treated calcium carbonate; methods of preparing a silane-modified polymer foam attached to a part of assembly in situ and to a silane-modified polymer foam obtained by the method, as well as a gasket, sealant or adhesive comprising a two-component foamable silane-modified polymer composition or said silane-modified polymer foam.

Claims

1. A two-component foamable silane-modified polymer composition comprising: a component A comprising (a-1) at least one silane modified polymer comprising polypropylene glycol repeating units, and (a-2) at least one chemical blowing agent selected from the group consisting of alkali metal bicarbonate, alkali metal carbonate, ammonium bicarbonate and ammonium carbonate, and a component B comprising (b-1) water, and (b-2) an organic acid selected from the group consisting of acids comprising a C.sub.6-C.sub.18 aryl group or an aralkyl group, dicarboxylic acids, and tricarboxylic acids, wherein component A and/or component B comprises at least one surface treated calcium carbonate.

2. The composition according to claim 1, wherein composition A comprises i) at least one compound of Formula (I) ##STR00009## wherein, in Formula (I), Y denotes an x-valent polymer radical bonded via nitrogen, oxygen, sulfur or carbon, R is independently selected from a monovalent, optionally substituted, SiC-bonded hydrocarbon radical, R.sup.1 is independently selected from hydrogen or a monovalent, optionally substituted hydrocarbon radical which may be attached to the carbon atom via nitrogen, phosphorus, oxygen, sulfur or carbonyl group, R.sup.2 is independently selected from hydrogen or a monovalent, optionally substituted hydrocarbon radical, x is an integer from 1 to 10, a is independently selected from 0, 1 and 2, and b is independently selected from an integer from 1 to 10; and/or ii) at least one compound containing units of the following Formula (V) ##STR00010## wherein, in Formula (V) R.sup.6 is independently selected from hydrogen, a monovalent, SiC-bonded, optionally substituted aliphatic hydrocarbon radical or a divalent, optionally substituted aliphatic hydrocarbon radical, which bridges two units of the formula (V) R.sup.7 is independently selected from hydrogen or a monovalent, optionally substituted hydrocarbon radical, R.sup.8 is independently selected from a monovalent, SiC-bound, optionally substituted aromatic hydrocarbon residue, c is 0, 1, 2 or 3, d is 0, 1, 2 or 3, and e is 0, 1 or 2, with the proviso that the sum of c+d+e is less than or equal to 3, wherein in at least 40% of the units of formula (V) the sum c+e is equal to 0 or 1.

3. The composition according to claim 2, wherein component A comprises at least one compound of Formula (I).

4. The composition according to claim 3, wherein at least one chemical blowing agent selected from the group consisting of LiHCO.sub.3, Li.sub.2CO.sub.3, NaHCO.sub.3, Na.sub.2CO.sub.3, KHCO.sub.3, and K.sub.2CO.sub.3.

5. The composition according to claim 4, wherein component B comprises at least one organic acid having a pK.sub.a of 1.0 to 8.0.

6. The composition according to claim 5, wherein said at least one organic acid is selected from the group consisting of para-toluenesulfonic acid, benzenesulfonic acid, phthalic acid, acetylsalicylic acid, salicylic acid, mandelic acid, glutaric acid, malonic acid, maleic acid, malic acid, adipic acid, oxalic acid and citric acid.

7. The composition according to claim 3, wherein component A comprises plasticizer.

8. The composition according to claim 3, wherein component A comprises at least one foam stabilizer.

9. The composition according to claim 3, wherein component A and/or component B comprises at least one surface treated silica.

10. The composition according to claim 3, wherein component A and/or component B comprises at least one aminosilane or aminosilane oligomer.

11. The composition according to claim 1, wherein component A comprises (a-1) 5 wt. % to 70 wt. % of at least one silane modified polymer comprising polypropylene glycol repeating units, (a-2) 0.5 wt. % to 25 wt. % of at least one chemical blowing agent selected from the group consisting of alkali metal bicarbonate, alkali metal carbonate, ammonium bicarbonate and ammonium carbonate, (a-3) 0 wt. % to 50 wt. % of plasticizer, (a-4) 0 wt. % to 10 wt. % of at least one foam stabilizer, (a-5) >0 wt. % to 80 wt. % of surface treated calcium carbonate, (a-6) 0 wt. % to 10 wt. % of surface treated silica, (a-7) 0 wt. % to 15 wt. % of at least one aminosilane or aminosilane oligomer, and (a-8) 0 wt. % to 5 wt. % of at least one catalyst, each based on the total weight of component A; and component B comprises (b-1) 0.5 wt. % to 80 wt. % of water, (b-2) 1 wt. % to 40 wt. % of at least one an organic acid selected from the group consisting of acids comprising a C.sub.6-C.sub.18 aryl group, an aralkyl group, dicarboxylic acids, tricarboxylic acids and mixtures thereof, (b-3) 0 wt. % to 80 wt. % of surface treated calcium carbonate, (b-4) 0 wt. % to 10 wt. % of surface treated silica, (b-5) 0 wt. % to 15 wt. % of at least one aminosilane or aminosilane oligomer, and (b-6) 0 wt. % to 5 wt. % of at least one catalyst, each based on the total weight of component B.

12. The composition according to claim 11, wherein the composition comprises the component A and the component B in a ratio by weight of ranging from 7:1 to 1:7.

13. A method for preparing a silane-modified polymer foam attached to a part of assembly in situ, comprising the steps: I. preparing a two-component foamable silane-modified polymer composition according to claim 1; II. mixing the component A and component B at a reaction temperature from 15 to 100 C. to form a reaction mixture; and III. applying the reaction mixture to at least one surface of part.

14. A silane-modified polymer foam obtained by the method according to claim 13.

15. A gasket, sealant or adhesive comprising the silane-modified polymer foam according to claim 14.

16. A gasket, sealant or adhesive comprising the two-component foamable silane-modified polymer composition according to claim 1.

Description

EXAMPLES

The Batch Preparation Proceeds as Follows:

[0275] 1. Component A: With a precision scale such as Sartorius BCA4202-1S the polyether-based dimethoxy(methyl) silylmethylcarbamatterminated polymer or the silyl-terminated polyether is weighed in a 310 mL PP cup. The NaCHO.sub.3, manually crushed for 10 min, is added afterwards. It is mixed with a Hauschild SpeedMixer DAC 400.2 VAC-P LR for l at 1500 RPM and 1 at 1950 RPM. [0276] 2. Component B is prepared the same way, weighing the acid first, then polyether-modified polysiloxane, water and finishing up with 2-ethylhexylphosphate. Mixing time and speed is the same as for Component A. [0277] 3. Component B is then added on top of component A. The same mixer is used at 2300 RPM for 30.

TABLE-US-00001 TABLE 1 2K formulations Comp. Comp. Comp. Comp. Comp. Ex. 1 Ex. 2 Ex. 3 Ex. 4 Ex. 5 Ex. 6 Component (wt. %) (wt. %) (wt. %) (wt. %) (wt. %) (wt. %) A polyether-based 69.15 0.00 dimethoxy(methyl)silylmethyl- carbamat-terminated polymer having polypropylene glycol backbone .sup.1 silyl-terminated polyether being 0.00 68.87 25.75 25.75 25.75 25.75 a mixture of an acrylate-based silane-modified polymer and a polypropylene glycol-based silane modified polymer.sup.2 NaHCO.sub.3 6.71 6.69 2.5 2.5 Un-coated CaCO.sub.3 .sup.4 2.978 Coated CaCO.sub.3 .sup.5 2.978 Coated CaCO.sub.3 .sup.6 6.44 B salicylic acid 11.19 11.15 8.22 8.22 4.11 4.11 water 5.97 5.94 1.03 1.03 1.03 2.22 polyether-modified 6.71 6.69 2.5 2.5 2.5 2.5 polysiloxane .sup.3 2-ethylhexylphosphate 0.27 0.67 0.5 0.5 0.5 1 .sup.1 Geniosil STP-E 30, CAS Nr. 611222-18-5; Wacker Chemie AG, Germany .sup.2Kaneka Silyl MA 490; Kaneka Corporation, Japan .sup.3 Tegostab B 8863 Z, Evonik Industries AG, Germany .sup.4 Omyacarb 5-SV, Omya AG, Switzerland .sup.5 Viscoexcel 30-SG, Omya AG, Switzerland .sup.6 Socal U1S1 G, Imerys SA, France

[0278] Samples were cured over 24 h. After that time a constant cell structure was obtained.

[0279] The sample preparation and testing proceeds as follows: [0280] For water absorption, 5 g samples from each batch are prepared. A week after they are made, they are submerged in water for exactly 24 h at room temperature. After that weight gain was determined. [0281] For hardness, density and compression set, 10 g samples are prepared. [0282] Shore 00 was measured according to and was determined by a standard lab Shore tester which is placed on top of the sample. [0283] Density is determined by water displacement. [0284] Compression set is determined by compressing the sample until 50% of its original height, stored in an oven at 70 C. for 22 h, compression clamps are removed, and the sample reconditioned at room temperature for 30 min. Then recovery is determined by comparing to the original foam. [0285] For mechanical property testing, 30 g of formulation are poured in a metal plate, from which S2 test specimen are cut and mechanical testing done with them in a Zwick tensile tester. [0286] Viscosity of the compositions were measured by Brookfield CAP 2000 viscometer, at 20 C. and 50% RH, spindle 5, 20 rpm.

TABLE-US-00002 TABLE 2 properties Comp. Comp. Ex. 3 Ex. 4 Comp. Comp. no no Comp. Comp. Property Ex. 1 Ex. 2 foam foam Ex. 5 Ex. 6 Ex. 7.sup.7 Hardness (Shore 00) 36.8 39.6 59 59 33.7 10.3 42 Density (g/cm.sup.3) 0.44 0.53 1.04 0.86 0.5 0.37 0.23 Compression Set (Absolute 48.39 n.d. n.d. n.d. n.d. 43.6 n.d. Loss, %) Elongation at Break (%) 147.30 283.40 n.d. n.d. n.d. 341 89 Tensile Strength (kPa) 73.63 474.33 n.d. n.d. n.d. 224 122 .sup.7K31-A-9675-5-VP/B-4; mix ratio 4.5:1 n.d. = not determined

Tack Test

[0287] Foamed adhesive beads of ca. 1 cm width of Example 1 or Example 2 were applied on a glass substrate. A paper strip (139 mm length, 41 mm width with a circumference of 38.85 mm at the top; 1.13 g, equipped with a wire) was placed on top of the foamed bead. On the circular part a 149 g weight was placed on the paper for exactly 1 min, totaling a pressure of 1,245 kPa.

[0288] After the pressure was applied, the substrate was put in perfectly vertical position and it was measured how much time it took for the paper to fall. Example 1 and 2 showed slipping of the paper between 45 and 90 seconds. With a non-tacky foam the paper fell off instantly. The comparative example shows no residual tack after full curing.