Moisture curable compositions

Abstract

A two-part moisture cure organosiloxane composition is disclosed. The two-part moisture cure organosiloxane composition comprises a base component and a catalyst package. The catalyst package undergoes minimal phase separation during storage.

Claims

1. A two-part moisture curing composition having: a base component; and a catalyst package component; wherein the catalyst package component comprises: (i) 40 to 65 wt. % of a polydialkylsiloxane having the general formula:
R.sup.3.sub.3Si—O—((R.sup.2).sub.2SiO).sub.d—SiR.sup.3.sub.3, where each R.sup.2 is an alkyl group or a phenyl group, each R.sup.3 is individually selected from R.sup.2, alkyl, phenyl, alkenyl or alkynyl groups, and d is an integer such that the polydialkylsiloxane (i) has a viscosity of from about 5 to about 100,000 mPa.Math.s at 25° C.; (ii) 15 to 30 wt. % of at least one dipodal silane in accordance with the general formula:
(R.sup.4O).sub.m(Y.sup.1).sub.3-mSi—(CH.sub.2).sub.x—((NHCH.sub.2CH.sub.2).sub.t-Q(CH.sub.2).sub.x).sub.n—Si(OR.sup.4).sub.m(Y.sup.1).sub.3-m, where each R.sup.4 is independently a C.sub.1-10 alkyl group, each Y.sup.1 is independently a C.sub.1-8 alkyl group, Q is a heteroatom containing moiety with a lone pair of electrons, each x is independently an integer of from 1 to 6, t is 0 or 1, each m is independently 1, 2 or 3, and n is 0 or 1; (iii) 2 to 20 wt. % of a cross-linker; and (iv) 0.01 to 3 wt. % of a tin based catalyst; each based on the total weight of the catalyst package; and wherein the base component comprises: (a) 20 to 80 wt. % of a siloxane polymer having at least two terminal hydroxyl or hydrolysable groups and a viscosity of from about 1,500 to about 150,000 mPa.Math.s at 25° C.; (b) 20 to 70 wt. % of at least one reinforcing filler; and (c) 0 to 20 wt. % of at least one non-reinforcing filler; each based on the total weight of the base component.

2. The two-part moisture curing composition in accordance with claim 1, wherein the dipodal silane (ii) is selected from the group consisting of bis (trimethoxysilyl)hexane, 1,2-bis (triethoxysilyl)ethane, bis (alkoxysilylalkyl)amines, bis (dialkoxyalkylsilylalkyl)amines, bis (trialkoxysilylalkyl)N-alkylamines, bis (dialkoxyalkylsilylalkyl)N-alkylamines, bis (trialkoxysilylalkyl)ureas, bis (dialkoxyalkylsilylalkyl)ureas, and combinations thereof.

3. The two-part moisture curing composition in accordance with claim 1, wherein the dipodal silane (ii) is selected from the group consisting of bis (3-trimethoxysilylpropyl)amine, bis (3-triethoxysilylpropyl)amine, bis (4-trimethoxysilylbutyl)amine, bis (4-triethoxysilylbutyl)amine, bis (3-trimethoxysilylpropyl)N-methylamine, bis (3-triethoxysilylpropyl)N-methylamine, bis (4-trimethoxysilylbutyl)N-methylamine, bis (4-triethoxysilylbutyl)N-methylamine, bis (3-trimethoxysilylpropyl)urea, bis (3-triethoxysilylpropyl)urea, bis (4-trimethoxysilylbutyl)urea, bis (4-triethoxysilylbutyl)urea, bis (3-dimethoxymethylsilylpropyl)amine, bis (3-diethoxymethyl silylpropyl)amine, bis (4-dimethoxymethylsilylbutyl)amine, bis (4-diethoxymethyl silylbutyl)amine, bis (3-dimethoxymethylsilylpropyl)N-methylamine, bis (3-diethoxymethyl silylpropyl)N-methylamine, bis (4-dimethoxymethylsilylbutyl)N-methylamine, bis (4-diethoxymethyl silylbutyl)N-methylamine, bis (3-dimethoxymethylsilylpropyl)urea, bis (3-diethoxymethyl silylpropyl)urea, bis (4-dimethoxymethylsilylbutyl)urea, bis (4-diethoxymethyl silylbutyl)urea, bis (3-dimethoxyethylsilylpropyl)amine, bis (3-diethoxyethyl silylpropyl)amine, bis (4-dimethoxyethylsilylbutyl)amine, bis (4-diethoxyethyl silylbutyl)amine, bis (3-dimethoxyethylsilylpropyl)N-methylamine, bis (3-diethoxyethyl silylpropyl)N-methylamine, bis (4-dimethoxyethylsilylbutyl)N-methylamine, bis (4-diethoxyethyl silylbutyl)N-methylamine, bis (3-dimethoxyethylsilylpropyl)urea, bis (3-diethoxyethyl silylpropyl)urea, bis (4-dimethoxyethylsilylbutyl)urea, bis (4-diethoxyethyl silylbutyl)urea, and combinations thereof.

4. The two-part moisture curing composition in accordance with claim 1, wherein the dipodal silane (ii) has the general formula:
(R.sup.4O).sub.3Si—(CH.sub.2).sub.x—(NHCH.sub.2CH.sub.2).sub.t—NH(CH.sub.2).sub.x—Si(OR.sup.4).sub.3, where each of R.sup.4, x, and t is as defined above.

5. The two-part moisture curing composition in accordance with claim 3, wherein the dipodal silane (ii) is selected from the group consisting of bis (3-tripropyloxysilypropyl)amine, bis (3-methyldiethoxysilypropyl)amine, bis (3-methyldimethoxysilypropyl)amine, bis (3-triethoxysilylpropyl)amine, bis (3-trimethoxysilylpropyl)amine, N,N′-bis [(3-trimethoxysilyl)propyl]ethylenediamine, and combinations thereof.

6. The two-part moisture curing composition in accordance with claim 1, wherein ingredients (i), (ii), (iii), and (iv) of the catalyst package component are substantially or completely miscible.

7. The two-part moisture curing composition in accordance with claim 1, wherein the siloxane polymer (a) is present in the composition in an amount of from about 10 to about 70 weight % based on the total weight of the base component.

8. The two-part moisture curing composition in accordance with claim 1, wherein the reinforcing filler (b) is selected from the group consisting of fumed silicas, precipitated silicas, precipitated calcium carbonate, and combinations thereof.

9. The two-part moisture curing composition in accordance with claim 1, wherein the weight ratio of the base component to the catalyst package component, when mixed, is between about 15:1 and about 1:1.

10. A one-part moisture curing composition comprising a mixture of the base component and the catalyst package component in accordance with the two-part moisture curing composition of claim 1.

11. An article comprising a composition or a reaction product thereof, wherein the composition is the two-part moisture curing composition in accordance with claim 1.

12. The article in accordance with claim 11, wherein the composition or reaction product thereof is further defined as a material selected from the group consisting of coating materials, caulking materials, mold making materials, encapsulating materials, and combinations thereof.

13. The two-part moisture curing composition in accordance with claim 1, wherein the polydialkylsiloxane (i) is unreactive with the siloxane polymer (a).

14. The two-part moisture curing composition in accordance with claim 1, wherein the catalyst package further comprises from 1 to 20 wt. % of a colored filler or pigment based on the total weight of the catalyst package.

Description

EXAMPLE 1

(1) Comparison of Phase separation in the catalyst package of two-part compositions as hereinbefore described using a dipodal silane adhesion promoter (Example 1) and a comparative commercial catalyst package Dow Corning® 983 SGS Curing Agent using standard (prior art) adhesion promoter (Comp. 1).

(2) TABLE-US-00001 TABLE 1a Example 1 (wt. %) Trialkyl-terminated diorganopolysiloxane 46.9 60,000 mPa .Math. s at 25° C. Carbon black 16.75 Fumed silica 3.35 bis (3-triethoxysilylpropyl)amine 16.401 tetraethyl orthosilicate 16.401 DMTDN (catalyst) 0.198

(3) Example 1 was prepared in a 10 liter Turello mixer. Using the following process: Step (i): the alkyl-terminated diorganopolysiloxane 60,000 mPa.Math.s at 25° C. was first introduced into the mixer. Step (ii): Carbon black was added and mixed into the alkyl-terminated diorganopolysiloxane for several minutes. Step (iii): the silica was then added and mixed into the product of step (ii). Step (iv): the product of step (iii) was then mixed for a further 10 minutes at a speed of 2000 rpm with a full vacuum applied. Step (v): the composition of step (iv) was then cooled to room temperature before the respective silanes and catalyst were introduced and mixed into the product of step (iv).

(4) Example 1 was found to work well in respect to effecting the cure of a two-part composition once mixed with a base component. The base component used with both the Example 1 and Comp. 1 to make the cured product for testing physical properties was a commercial base component from Dow Corning (Dow Corning® 983 Silicone Glazing and Curtainwall Base).

(5) The base component and respective catalyst packages were mixed using a Plas-Pak pneumatic gun, and Ratio-Pak® 8:1 cartridges. After loading a cartridge onto the gun, the caps were removed, and the plungers were advanced so that both curing agent and base were flowing from the nozzle. A 36-element static mixer was attached, and material was extruded until no streaks were observed in the mixed material. Once a uniform mix was achieved, test samples were prepared. All material was extruded at approximately 97 psi (668.8 kPa).

(6) The resulting Example 1 catalyst package was then placed in a 5 gallon pail and allowed to age for a period of 1 year at room temperature. Likewise an off the shelf sample of Comp. 1 was aged in the same manner. After one year room temperature storage in a 5 gallon pail, Example 1 exhibited separation of <2 mm. After two months of room temperature storage, Comp.1 exhibited up to 40 mm of phase separation. These values were measured by ruler.

EXAMPLE 2

(7) A variety of catalyst package samples as hereinbefore described were prepared in accordance with the process in Example 1 above. The compositions utilized for the catalyst package were as defined in Table 2a below:

(8) TABLE-US-00002 TABLE 2a Sample 1 Sample 2 Sample 3 Sample 4 Trialkyl-terminated 53.60 53.60 50.25 46.90 diorganopolysiloxane 60,000 mPa .Math. s at 25° C. Carbon Black 9.38 9.38 13.07 16.75 Fumed Silica 4.02 4.02 3.69 3.35 bis (3-triethoxy- 16.40 16.40 12.19 12.19 silylpropyl)amine Tetraethyl 16.40 16.40 20.61 20.61 orthosilicate (TEOS) Dimethyltin 0.20 0.20 0.20 0.20 dineodecanoate (DMTDN)

(9) The different samples were then aged using a QUV Accelerated Weathering Tester Model QUV/se for set durations as indicated in Table 2b below. The QUV aging was a cycle of eight hours UVA at 0.89 irradiance and 60° C., followed by four hours of condensation at 50° C. A second commercial catalyst package Dow Corning® 982 Curing Agent (Comp. 2) was also aged as a further comparison.

(10) These catalyst packages were again inter-mixed with Dow Corning® 983 Silicone Glazing and Curtainwall Base after aging in the manner described in respect to Example 1 and physical properties of the resulting cured materials were determined. Tensile strength and elongation were tested according to ASTM D412-98A(2002) e1 test method A. A 100 mil (2.54 mm) slab of material was drawn down on polyethylene terephthalate (PET) and cured seven days at room temperature and 50% relative humidity (RH). Post cure conditions are as reported. Dogbones were cut using die DIN S2, and pulled on an MTS Alliance R/5 at 20.0 in/min (0.01 ms.sup.−1) using a 5 kN load cell. Data was collected and analyzed using Test Works Elite v. 2.3.6.

(11) Durometer was measured on a Shore® Conveloader CV-71200 type A. Samples were stacked ½″ (1.27 mm) thick, and values reported are an average of three.

(12) TABLE-US-00003 TABLE 2b Shore Durometer A Durometer Shore A Durometer Shore A (7 Days) (10,000 hours QUV) Sample 1 37 35 Sample 2 39 38 Sample 3 38 34 Sample 4 41 36 Comp. 2 37 42 Comp. 1 39 29

(13) The durometer of the dipodal samples (1-4) remained stable after the QUV aging. We would expect to see a slightly lower durometer after this aging test. Comp. 2 (Dow Corning® 982 Silicone Insulating Glass Sealant), actually increases in durometer which can be problematic in field application where some amount of movement is desirable. Dow Corning® 983 SGS Curing Agent (Comp. 1) degrades much more in durometer than the dipodal examples and appears to be less hydrolytically stable.

(14) TABLE-US-00004 TABLE 2c Tensile Strength Tensile Strength (PSI) Tensile Strength (PSI) (7 days) (10,000 hours QUV) Sample 1 354.5 290.7 Sample 2 330.3 297.3 Sample 3 348.6 292.4 Sample 4 311 233.5 Comp. 2 282.2 143.8 Comp. 1 301.1 193.5

(15) The dipodal examples maintained higher tensile strength after QUV aging, indicating that they are more hydrolytically stable than both comp. 1 and Comp. 2.

(16) TABLE-US-00005 TABLE 2d Elongation Elongation (%) Elongation (%) (7 days) (10,000 hours QUV) Sample 1 440.206 353.932 Sample 2 355.63 381.351 Sample 3 389.814 449.018 Sample 4 276.907 321.498 Comp. 2 311.655 168.159 Comp. 1 383.428 407.317

(17) TABLE-US-00006 TABLE 2e 50% modulus 50% modulus 50% modulus (7 days) (10,000 hours QUV) Sample 1 66.34 65.272 Sample 2 70.957 66.563 Sample 3 69.562 59.729 Sample 4 84.738 64.938 Comp. 2 63.585 74.609 Comp. 1 71.696 51.373

(18) The modulus of the dipodal examples (1-4) remained stable after the QUV aging. We would expect to see a slightly lower modulus after this aging test. Comp 2 actually increases in modulus, which can be problematic in field application where some amount of movement is desirable. Comp. 1 degrades slightly more in modulus than the dipodal examples and appears to be less hydrolytically stable.

(19) TABLE-US-00007 TABLE 2f 100% modulus 100% modulus 100% modulus (7 days) (10,000 hours QUV) Sample 1 107.832 105.304 Sample 2 117.521 104.811 Sample 3 115.762 92.207 Sample 4 138.408 102.467 Comp. 2 108.645 112.185 Comp. 1 112.702 75.724

(20) QUV durability of the examples is on par with Comp.1 and does not degrade significantly nor increase in modulus, which is a drawback of Comp. 2.

(21) The terms “comprising” or “comprise” are used herein in their broadest sense to mean and encompass the notions of “including,” “include,” “consist(ing) essentially of,” and “consist(ing) of.” The use of “for example,” “e.g.,” “such as,” and “including” to list illustrative examples does not limit to only the listed examples. Thus, “for example” or “such as” means “for example, but not limited to” or “such as, but not limited to” and encompasses other similar or equivalent examples. The term “about” as used herein serves to reasonably encompass or describe minor variations in numerical values measured by instrumental analysis or as a result of sample handling. Such minor variations may be in the order of ±0-25, ±0-10, ±0-5, or ±0-2.5, % of the numerical values. Further, The term “about” applies to both numerical values when associated with a range of values. Moreover, the term “about” may apply to numerical values even when not explicitly stated.

(22) Generally, as used herein a hyphen “-” or dash “—” in a range of values is “to” or “through”; a “>” is “above” or “greater-than”; a “≥” is “at least” or “greater-than or equal to”; a “<” is “below” or “less-than”; and a “≤” is “at most” or “less-than or equal to.” On an individual basis, each of the aforementioned applications for patent, patents, and/or patent application publications, is expressly incorporated herein by reference in its entirety in one or more non-limiting embodiments.

(23) It is to be understood that the appended claims are not limited to express and particular compounds, compositions, or methods described in the detailed description, which may vary between particular embodiments which fall within the scope of the appended claims. With respect to any Markush groups relied upon herein for describing particular features or aspects of various embodiments, it is to be appreciated that different, special, and/or unexpected results may be obtained from each member of the respective Markush group independent from all other Markush members. Each member of a Markush group may be relied upon individually and or in combination and provides adequate support for specific embodiments within the scope of the appended claims.

(24) It is also to be understood that any ranges and subranges relied upon in describing various embodiments of the present invention independently and collectively fall within the scope of the appended claims, and are understood to describe and contemplate all ranges including whole and/or fractional values therein, even if such values are not expressly written herein. One of skill in the art readily recognizes that the enumerated ranges and subranges sufficiently describe and enable various embodiments of the present invention, and such ranges and subranges may be further delineated into relevant halves, thirds, quarters, fifths, and so on. As just one example, a range “of from 0.1 to 0.9” may be further delineated into a lower third, i.e., from 0.1 to 0.3, a middle third, i.e., from 0.4 to 0.6, and an upper third, i.e., from 0.7 to 0.9, which individually and collectively are within the scope of the appended claims, and may be relied upon individually and/or collectively and provide adequate support for specific embodiments within the scope of the appended claims. In addition, with respect to the language which defines or modifies a range, such as “at least,” “greater than,” “less than,” “no more than,” and the like, it is to be understood that such language includes subranges and/or an upper or lower limit. As another example, a range of “at least 10” inherently includes a subrange of from at least 10 to 35, a subrange of from at least 10 to 25, a subrange of from 25 to 35, and so on, and each subrange may be relied upon individually and/or collectively and provides adequate support for specific embodiments within the scope of the appended claims. Finally, an individual number within a disclosed range may be relied upon and provides adequate support for specific embodiments within the scope of the appended claims. For example, a range “of from 1 to 9” includes various individual integers, such as 3, as well as individual numbers including a decimal point (or fraction), such as 4.1, which may be relied upon and provide adequate support for specific embodiments within the scope of the appended claims.

(25) The present invention has been described herein in an illustrative manner, and it is to be understood that the terminology which has been used is intended to be in the nature of words of description rather than of limitation. Many modifications and variations of the present invention are possible in light of the above teachings. The present invention may be practiced otherwise than as specifically described within the scope of the appended claims. The subject matter of all combinations of independent and dependent claims, both single and multiple dependent, is herein expressly contemplated.