SEALANT COMPOSITION

Abstract

One-part condensation curable silyl-modified polymer (SMP) based sealant compositions in particular one-part condensation curable SMP based sealant compositions containing a catalyst comprising (i) a titanate and/or zirconate and (ii) a metal carboxylate salt which compositions upon cure provide elastomeric sealants having low modulus and a high elastic recovery.

Claims

1. A one-part condensation curable silyl modified polymer-based sealant composition comprising: (a) a silyl modified organic polymer having at least two (R).sub.m(Y.sup.1).sub.3−m—Si— groups per molecule where each R is hydroxyl or a hydrolysable group, each Y.sup.1 is an alkyl group containing from 1 to 8 carbons and m is 1, 2 or 3, which organic polymer is selected from polyethers, hydrocarbon polymers, acrylate polymers, polyesters, polyurethanes, and polyureas; (b) a reinforcing filler; (c) one or more plasticizers; and (d) a catalyst comprising (i) a titanate and/or zirconate and (ii) a metal carboxylate salt.

2. The one-part condensation curable silyl modified polymer-based sealant composition in accordance with claim 1, wherein catalyst (d) is the metal carboxylate salt (ii) and the metal of the metal carboxylate salt (ii) is selected from the group consisting of zinc, aluminium, bismuth, zirconium, and combinations thereof.

3. The one-part condensation curable silyl modified polymer-based sealant composition in accordance with claim 1, wherein catalyst (d) is the metal carboxylate salt (ii) and is selected from the group consisting of zinc (II) carboxylates, aluminium (III) carboxylates, bismuth (III) carboxylates, zirconium (IV) carboxylates, zinc (II) alkylcarboxylates, aluminium (III) alkylcarboxylates, bismuth (III) alkylcarboxylates, zirconium (IV) alkylcarboxylates, and combinations thereof.

4. The one-part condensation curable silyl modified polymer-based sealant composition in accordance with claim 1, wherein catalyst (d) is the metal carboxylate salt (ii) and selected from the group consisting of zinc ethylhexanoate, bismuth ethylhexanoate, zinc stearate, zinc undecylenate, zinc neodecanoate, and iron (III) 2-ethylhexanoate.

5. The one-part condensation curable silyl modified polymer-based sealant composition in accordance with claim 1, wherein the titanate and/or zirconate (i) and the metal carboxylate salt (ii) of catalyst (d) is provided in a molar ratio of 1:4 to 4:1.

6. The one-part condensation curable silyl modified polymer-based sealant composition in accordance with claim 1, wherein silyl modified organic polymer (a) is a polyether terminated with
(R).sub.m(Y.sup.1).sub.3−m—Si-D-[NH—C(═O)].sub.k— where each R is hydroxyl or a hydrolysable group, each Y.sup.1 is an alkyl group containing from 1 to 8 carbons, m is 1, 2 or 3, D is a divalent C.sub.2-6 alkylene group and k is 1 or 0.

7. The one-part condensation curable silyl modified polymer-based sealant composition in accordance claim 6, wherein k is 0.

8. The one-part condensation curable silyl modified polymer-based sealant composition in accordance with claim 1, which is gunnable and/or self-levelling.

9. The one-part condensation curable silyl modified polymer-based sealant composition in accordance with claim 1, capable of being applied as a paste to a joint between two adjacent substrate surfaces where it can be worked, prior to curing, to provide a smooth surfaced mass which will remain in its allotted position until it has cured into an elastomeric body adherent to the adjacent substrate surfaces.

10. A silicone elastomer which is the reaction product of the one-part condensation curable silyl modified polymer-based sealant composition in accordance with claim 1.

11. The silicone elastomer in accordance with claim 10, which upon cure provides a sealant with a low modulus of ≤0.45 MPa at 100% elongation and/or has an elastic recovery of ≥80%.

12. A method of making the one-part condensation curable silyl modified polymer-based sealant composition in accordance with claim 1, the method comprising mixing all of the ingredients together.

13. A sealant suitable for use in the facade, insulated glass, window construction, automotive, solar and construction fields, wherein the sealant comprises or is formed from the one-part condensation curable silyl modified polymer-based sealant composition in accordance with claim 1.

14. A method for filling a space between two substrates so as to create a seal therebetween, the method comprising: a) providing the one-part condensation curable silyl modified polymer-based sealant composition in accordance with claim 1, and either b) or c); b) applying the sealant composition to a first substrate, and bringing a second substrate in contact with the sealant composition that has been applied to the first substrate, or c) filling a space formed by the arrangement of a first substrate and a second substrate with the sealant composition and curing the sealant composition.

15. The method for filling a space between two substrates in accordance with claim 14, wherein the space is filled by introducing the sealant composition by way of extrusion or through a sealant gun.

Description

EXAMPLES

[0113] Comparative sealant compositions were prepared using the compositions in Table 1 which can be seen to contain the essential ingredients and several optional ingredients.

TABLE-US-00001 TABLE 1 Composition of Comparative Examples Comp. 1 Comp. 2 Comp. 3 Comp. 4 (wt. %) (wt. %) (wt. %) (wt. %) Kaneka Silyl ™ SAX510 14.25 13.71 13.90 14.25 Kaneka Silyl ™ SAX520 6.11 5.88 5.96 6.11 Diisononyl phthalate (DINP) 22.00 22.00 22.00 22.00 Light Stabilizer 0.23 0.23 0.23 0.23 Irganox 1076 (antioxidant) 0.23 0.23 0.23 0.23 Rheology modifier 2.20 2.20 2.20 2.20 XTCC-201 Precipitated calcium carbonate 22.0 22.0 22.0 22.00 Omyacarb ® IT Ground calcium carbonate 29.8 29.8 29.8 29.80 Titanium dioxide 1.20 1.20 1.20 1.20 vinyltrim ethoxy silane 1.40 1.40 1.40 1.40 ethylenediaminepropyltrimethoxysilane 0.07 0.07 0.07 0.07 Methyl acetoacetate 0.480 0.336 Ethylhexanoic acid zinc salt Zn(EHA).sub.2 0.52 Ethylhexanoic acid bismuth salt Bi(EHA).sub.3 0.75 Tetra tertiary butyl titanate (TtBT) 0.80 Tetra isopropyl titanate 0.67

[0114] Kaneka Silyl™ SAX510 and Kaneka Silyl™ SAX520 are both isocyanate free polymers having a polymeric chain of repeating polypropyleneoxide units and with trimethoxysilyl terminal groups; [0115] XTCC-201 PCC is a surface treated precipitated calcium carbonate Jiangxi Xintai Chemical; [0116] Omyacarb® 1T is a ground calcium carbonate from Omya having an average particle size of 2 μm; [0117] The light stabilizer used was Tinuvin® 765 from BASF, which we believe is a mixture of bis(1,2,2,6,6-pentamethyl-4-piperidyl)sebacate and methyl 1,2,2,6,6-pentamethyl-4-piperidyl sebacate; [0118] Irganox® 1076 by BASF is octadecyl-3-[3,5-di-tert-butyl-4-hydroxyphenyl]propionate]. It is a highly efficient sterically hindered phenolic primary antioxidant. Provides processing and long-term thermal stabilization; and [0119] CRAYVALLAC® SLT is a high performance micronised amide wax rheology modifier from Arkema.

[0120] The comparative sealant compositions were prepared using the above compositions on a 10 L Turello Mixer according to the process described as below. [0121] Firstly, Kaneka Silyl™ SAX510 and Kaneka Silyl™ SAX520 polymers were introduced into the mixer. Subsequently the following ingredients were added sequentially, namely: [0122] DINP, [0123] Irganox® 1076, [0124] Tinuvin® 765, SLT, [0125] Omyacarb® 1T, R-630, and [0126] XTCC-201 PCC.

[0127] The mixture was then stirred at 800 revolutions per minute (rpm) at full vacuum for 90 minutes at 105° C. and cooled to <45° C. Once the temperature of the composition was <45° C., the remaining ingredients were added i.e. vinyltrimethoxy silane, the relevant catalyst(s), ethylenediaminepropyltrimethoxysilane and methyl acetoacetate. The final mixture was then mixed for a further 20 minutes in a nitrogen atmosphere and subsequently deaired by applying a vacuum at −75 kPa pressure and then was then packaged into standard cartridges for testing.

[0128] The compositions prepared as described above were then tested for their physical properties as depicted in Table 2 below. All samples tested hereafter in accordance with (ASTM D412-98a (2002)e1) utilized dumbbell shaped test pieces.

TABLE-US-00002 TABLE 2a General Physical Properties of Comparative Examples Comp. Comp. Comp. Comp. 1 2 3 4 Tack free time (TFT) (mins.) (ASTM C679-15) >360 141 >360 >360 Tensile strength (MPa) (ASTM D412-98a Not fully 0.95 0.82 0.93 (2002)e1) cure after 7 days Elongation, % (ASTM D412-98a (2002)el) NA 606 556 816 Modulus at 100%, (MPa) (ASTM D412-98a NA 0.387 0.355 0.135 (2002)e1) Modulus at 150%, (MPa) (ASTM D412-98a NA 0.442 0.406 (2002)e1) Modulus at 200%, (MPa) (ASTM D412-98a NA 0.490 0.454 0.216 (2002)e1) Hardness, shore A (ASTM C 661-15) NA 16.7 15.8 6.3 Elastic recovery, % NA 86.5 84.8 82.6

[0129] Elastic recovery: The length of 2.54 cm (1.0 inch) was marked by ink on the dumbbell specimens with about 2 mm in thickness as original length (A); The dumbbell was stretched by 100%, (i.e. to 5.08 cm, 2.0 inch=B) and maintained at 100% extension for 24 hours; subsequently the dumbbell was released and allowed to recover for 1 hour; Test final length (C) between the marks. The elastic recovery was determined as =(B-C)/(B-A)*100%

[0130] Adhesion properties of the Comparative examples were also assessed and are depicted in Table 2b below.

TABLE-US-00003 TABLE 2b Adhesion Properties of Comparative Examples Comp. Comp. Comp. Comp. 1 2 3 4 Peel adhesion on concrete with primer P after 14 NA 70 100 100 days cure, (% CF) ASTM C794-18 Peel stress on concrete with primer P after 14 days NA 4027.9 4658.4 844.1 cure, (N/m) (average) ASTM C794-18 Peel adhesion on concrete with primer P after NA 15 10 100 additional 1 day water immersion, (% CF) ASTM C794-18 Peel stress on concrete with primer P after additional NA 4203.0 3502.5 632.2 1 day water immersion, (N/m) (average) ASTM C794-18

[0131] Primer P is DOWSIL™ Construction Primer P a commercially available Adhesion promoter from Dow Silicones Corporation for use on masonry surfaces. It comprises an alkoxy silane resin formulation in solvent.

[0132] Cohesive failure (CF) is observed when the coating itself breaks without detaching from the substrate (for example, steel plate). In some cases, a mixed failure mode may be observed; that is some areas peel-off (i.e. AF) while some remain covered with coating (i.e. CF). In such cases, the portions of surface displaying CF (%CF).

[0133] The Examples in accordance with this disclosure were also made via the same method as described above using the compositions depicted in Table 3 below

TABLE-US-00004 TABLE 3 Composition of Examples Ex. 1 Ex. 2 Ex. 3 Ex. 4 (wt. %) (wt. %) (wt. %) (wt. %) Kaneka Silyl ™ SAX510 13.69 13.78 13.69 13.78% Kaneka Silyl ™ SAX520 5.87 5.90 5.87  5.90% Diisononyl phthalate (DINP) 22.00 22.00 22.00 22.00% Light Stabilizer 0.23 0.23 0.23  0.23% Irganox 1076 (antioxidant) 0.23 0.23 0.23  0.23% Rheology modifier 2.20 2.20 2.20  2.20% XTCC-201 Precipitated 22.0 22.0 22.0  22.0% calcium carbonate Omyacarb ® IT Ground 29.8 29.8 29.8  29.8% calcium carbonate Titanium dioxide 1.20 1.20 1.20  1.20% vinyltrim ethoxy silane 1.40 1.40 1.40  1.40% ethylenediaminepropyl- 0.07 0.07 0.07  0.07% trimethoxysilane Ethylhexanoic acid zinc 0.52  0.52% salt Zn(EHA).sub.2 TtBT 0.80  0.67% Ti(i-PrO).sub.4 TtBT: Zn(EHA).sub.2 1.32 (2:1 by Molar ratio) Ti(i-PrO).sub.4: Zn(EHA).sub.2 1.19 (2:1 by Molar ratio)

TABLE-US-00005 TABLE 4a General Physical Properties of Examples Ex. 1 Ex. 2 Ex. 3 Ex. 4 Tack free time (TFT) (mins.) (ASTM C679-15) 160 171 98 102 Tensile strength (MPa) (ASTM D412-98a(2002)e1) 0.72 0.71 0.73 0.66 Elongation, % (ASTM D412-98a(2002)e1) 529 697 681 696 Modulus at 100%, (MPa) (ASTM D412-98a(2002)e1) 0.358 0.325 0.304 0.274 Modulus at 150%, (MPa) (ASTM D412-98a(2002)e1) 0.421 0.388 0.379 0.346 Modulus at 200%, (MPa) (ASTM D412-98a(2002)e1) 0.464 0.431 0.425 0.392 Hardness, shore A (ASTM C 661-15) 14.5 13.8 13.8 12.3 Elastic recovery, % 87.1 84.6 84.0 81.2

TABLE-US-00006 TABLE 4b General Physical Properties of Examples Ex. 1 Ex. 2 Ex. 3 Ex. 4 Peel adhesion on concrete with primer P after 14 100 100 100 100 days cure, % CF (ASTM C794-18) Peel stress on concrete with primer P after 14 days 3695.18 3677.67 3550.15 3082.23 cure, N/m (average) (ASTM C794-18) Peel adhesion on concrete with primer P after additional 1 day water immersion, % CF (ASTM 100 100 100 100 C794-18) Peel stress on concrete with primer P after 4780.96 4763.45 3239.85 3502.54 additional 1 day water immersion, N/m (average) (ASTM C794-18)

[0134] For comparative example 1, the sample with only Zn(EHA).sub.2 as catalyst cannot fully cure even after seven days conditioning at room temperature and proved low catalytic activity. As for comparative example 2 and 3 only with Ti catalyst, the samples can get low modulus and high elastic recovery, but the adhesion was not good on concrete, especially after water immersion condition. As for inventive examples 4, and 5 using the catalyst described herein, both samples recorded modulus values of less than 0.4 MPa with elastic recovery above than 80% and had good adhesion on concrete. The addition of Zn(EHA).sub.2 and Ti separately as catalyst got similar results as the pre-mixing of Zn(EHA).sub.2 and Ti, such as the low modulus, high elastic recovery and good adhesion on concrete, as seen from inventive example 6 and 7.

TABLE-US-00007 TABLE 5 Composition of Examples Ex. 5 Ex. 6 Ex. 7 (wt. %) (wt. %) (wt. %) Kaneka Silyl ™ SAX510   13.69% 13.69%   13.69% Kaneka Silyl ™ SAX520    5.87%  5.87%    5.87% Diisononyl phthalate (DINP)   22.00% 22.00%   22.00% Light Stabilizer    0.23%  0.23%    0.23% Irganox 1076 (antioxidant)    0.23%  0.23%    0.23% Rheology modifier    2.20%  2.20%    2.20% XTCC-201 Precipitated calcium carbonate   22.00% 22.00%   22.00% Omyacarb ® IT Ground calcium carbonate   29.80% 29.80%   29.80% Titanium dioxide    1.20%  1.20%    1.20% vinyltrimethoxy silane    1.40%  1.40%    1.40% ethylenediaminepropyltrimethoxysilane    0.07%  0.07%    0.07% Ethylhexanoic acid zinc salt Zn(EHA).sub.2    0.48%  0.58%    0.14% Methyl acetoacetate    0.48%  0.58%    0.14% Ethylhexanoic acid zinc salt Zn(EHA).sub.2      0.25%  −0.98% Ethylhexanoic acid bismuth salt Bi(EHA).sub.3    0.75% TtBT  −0.80%  0.97%    0.24%

TABLE-US-00008 TABLE 6a General Physical Properties of Examples Ex. 5 Ex. 6 Ex. 7 Tack free time (TFT) (mins.) (ASTM C679-15) 259 70 98 Tensile strength (MPa) (ASTM D412-98a(2002e1)) 0.83 0.79 0.58 Elongation, % (ASTM D412-98a(2002e1)) 763 550 803 Modulus at 100%, (MPa) (ASTM D412-98a(2002e1)) 0.200 0.301 0.116 Modulus at 200%, (MPa) (ASTM D412-98a(2002e1)) 0.290 0.442 0.197 Hardness Shore A (ASTM C 661-15) 10.2 14.6 5.8 Elastic Recovery (%) 75.4 84.6 79.7

TABLE-US-00009 TABLE 6b General Physical Properties of Examples Ex. 5 Ex. 6 Ex. 7 Peel adhesion on concrete with primer P 100 100 100 after 14 days cure, % CF (ASTM C794-18) Peel stress on concrete with primer P after 14 days 3695.18 3677.66 3660.15 cure, N/m (average) (ASTM C794-18) Peel adhesion on concrete with primer P after 100 100 100 additional 1 day water immersion, % CF (ASTM C794-18) Peel stress on concrete with primer P after 4780. 4763.45 3239.85 additional 1 day water immersion, N/m (average) (ASTM C794-18)

[0135] The standard JC/T881 classifies joint sealants which have a low modulus and high elastic recovery in classes 35LM and 50LM. Sealants meeting the technical requirements to be included in these classes are recognized as high-grade sealants, suitable as construction sealants, more particularly as exterior facing sealants. Whilst SMP based sealants which meet the requirements of class 35LM and/or 50 LM according to standard JC/T881 are known, they generally, contain organotin compounds as catalysts and/or phthalate-containing plasticizers both of which can have regulatory issues whereas we have shown that catalysts as described herein provide suitable elastomeric sealants.