JPH0668103B2 - Self-leveling silicone sealant composition and method for producing the same - Google Patents

Description

Description: BACKGROUND OF THE INVENTION The present invention relates to self-leveling silicone sealant compositions and methods of making the same. More specifically, the present invention provides an amine, such as n, as a self-leveling agent in the composition.
-One-component acyloxy-functional room temperature curable (RTV) silicone compositions containing hexylamine.

In many applications it is desirable to use self-leveling silicone sealant compositions. Traditionally, self-leveling, one-component silicone RTV's have been manufactured with untreated fumed silica fillers. The manufacturing process for making these self-leveling compositions requires very rigorous shear mixing conditions as well as high temperatures to effect the mixing.

Thus, both treated and untreated silica fillers can be used in the manufacture and self-leveling one-component silicones that do not require vigorous shear mixing at elevated temperatures.
Providing RTV is highly desirable.

Bruner U.S. Pat. No. 3,035,016 discloses a room temperature curable silicone composition of the formula:

Where A _C is a saturated aliphatic monoacyl group of carboxylic acid, R
And R ¹ is selected from the group consisting of a monovalent hydrocarbon group, a monovalent halogenated hydrocarbon group and a cyanoalkyl group, and n
Is an integer of 5 or more. Acyloxy-functional polysiloxanes are acyloxysilanes of the formula: R ¹ Si (OA _C ) ₃ having the formula: Prepared by reacting with a hydroxylated siloxane. Where R and R ¹ are as defined above.

Bruner, U.S. Pat. No. 3,077,465, discloses a room temperature curable composition described in U.S. Pat. 0.001 to 1 metal carboxylate
It is taught that 0 wt% may be included.

US Pat. No. 3,133,891 to Ceyzeriat discloses the formula: R ₂ SiO [wherein each R is a monovalent radical selected from the group consisting of halogenated and halogen-free aliphatic, cycloaliphatic and aromatic hydrocarbon radicals. A linear diorganopolysiloxane containing 0.1% by weight or more of hydroxyl groups and 0.5 to 25% by weight of the formula: R ¹ Si (OCOR ² ) based on this diorganopolysiloxane. ₃ [R ¹ is a monovalent group selected from the group consisting of lower alkyl, alkenyl, aryl and aralkyl groups, and R ² is selected from the group consisting of alkyl groups and aryl groups having 1-18 carbon atoms. Which is a monovalent group], and a room temperature curable composition containing the organotriacyloxysilane.

Kulpa U.S. Pat. No. 3,296,161 states that at about 25 ° C
Viscosity of 200 to about 500,000 centipoise, 0.02 to 2%
An organopolysiloxane containing silicon-bonded hydroxyl groups, and 0.2 parts per 100 parts of this organopolysiloxane.
-6 parts dialkoxydiacyloxysilane and 1.8 parts
Silicone compositions containing -6 parts of organotriacyloxysilane are described.

US Pat. No. 3,296,195 to Goossens discloses a silicone RTV containing silanol terminated polydiorganosiloxane and alkoxyacyloxysilane.
Disclosed is a composition, wherein the alkoxyacyloxysilane is bonded to 0 or 1 silicon selected from four monovalent hydrocarbon groups of silicon, a monovalent halogenated hydrocarbon group and a cyanoalkyl group. It is filled with at least one group selected from a group, an alkoxy group and a halogenated alkoxy group, and at least one saturated aliphatic monoacyl group.

Beers U.S. Pat. No. 3,382,205 states that
(A) 100 parts of silanol-terminated organopolysiloxane essentially consisting of chemically bonded diorganosiloxane units of the formula: R ₂ SiO, (B) curing agent of the formula: RSi (OCOR ¹ ) ₃ 2-
20 parts, and (C) formula: R SiO _1.5 organosiloxy units and formula: R ₃ SiO _0.5 triorganosiloxy units and (A)
Is a substantially anhydrous organopolysiloxane composition which contains 2-30 parts of an organosilicon processing aid chemically bound to diorganosiloxy units and cures to a rubber elastic state when exposed to moisture at room temperature. It is disclosed. Here, the organosilicon processing aid has 0.1 to 8% by weight of hydroxy groups bonded to silicon, the ratio of organosiloxy units to diorganosiloxy units is 0.11 to 1.4, and triorganosiloxy units to diorganosiloxy units. The ratio is 0.02-1.

However, none of these references disclose or suggest the inclusion of amines to render the curable composition self-leveling.

All of the above patents are acyloxy functional silicone RT
The teachings regarding V compositions are given as prior art to the present invention.

DISCLOSURE OF THE INVENTION It is an object of the present invention to provide a self-leveling organopolysiloxane composition that cures to a rubbery elastic state when exposed to moisture.

It is another object of the present invention to provide a method of making a self-leveling silicone RTV composition that does not require vigorous shear mixing at elevated temperatures.

Yet another object of the present invention is to provide a self-leveling silicone composition that can use both treated and untreated silica fillers.

According to one embodiment of the invention, the above-mentioned objects are: (a) an acyloxy-terminated polydiorganosiloxane, (b) an effective amount of a condensation catalyst, and (c) an amount effective to render the composition self-leveling. This is achieved by a one-component organopolysiloxane composition containing an amine.

In another embodiment of the present invention, (a) silanol terminated polydiorganosiloxane, (b) per mole of silicon-bonded hydroxyl groups of (a),
Provided is a self-leveling silicone RTV composition comprising about 1 mole or more of a polyacyloxysilane, (c) an effective amount of a condensation catalyst, and (d) an amount of an amine effective to render the composition self-leveling. It

Reinforcing fillers, such as treated and untreated fumed silica, are also preferably included in the room temperature curable compositions of the present invention. The composition of the present invention may further contain other additives known in the art, if necessary.

DETAILED DESCRIPTION OF THE INVENTION The present invention comprises: (a) an acyloxy-terminated polydiorganosiloxane, (b) an effective amount of a condensation catalyst, and (c) an amount of an amine effective to render the composition self-leveling. Provided is a self-leveling, one-component room temperature curable silicone composition that cures to a rubbery elastic state upon exposure.

The acyloxy-terminated polydiorganosiloxane of (a) has the general formula: Preferably. In the formula, A _C is a saturated aliphatic monoacyl group, R and R ¹ are each independently selected from the group consisting of a monovalent hydrocarbon group, a monovalent halogenated hydrocarbon group and a cyanoalkyl group, and n is 5 The above integer, a is 0 or 1.

The acyloxy terminated polydiorganosiloxane of formula I is
A polyacyloxysilane of the formula: (R ¹ ) aSi (OA _C ) _4- a (II), where R ¹ , a and A _C are as defined above, is represented by the formula: Of silanol-terminated polydiorganosiloxane (R in the formula
And n are as defined above). Since it is believed that the reaction of the acyloxysilane with the hydroxyl-terminated polydiorganosiloxane occurs by mixing the two, compounds of formula II and formula III can be used in place of the acyloxy-terminated polymer of formula I.

In Formulas I and II, A _C is a saturated aliphatic monoacyl group of a carboxylic acid. Specifically, an acyl group having 4 or less carbon atoms, for example, a formyl, acetyl, propionyl and butyryl group is preferable. However, the acyl group can also be a group such as hexoyl, 2-ethylhexoyl, octanoyl, isovaleryl, stearyl and the like. Most preferably, A _C is an acetyl group, and thus this type of curable composition is referred to in the art as an acetoxy sealant. R ¹ may be any monovalent hydrocarbon group, specifically an alkyl group such as methyl, ethyl,
Propyl or octadecyl; alkenyl groups such as vinyl, allyl or hexenyl; cycloaliphatic groups such as cyclopentyl, cyclohexyl or cyclohexenyl; alkaryl groups such as benzyl or β-phenylethyl; or aromatic groups such as phenyl, tolyl, xylyl. , Naphthyl, xenyl or phenanthryl. R ¹ can also be any monovalent halogenated hydrocarbon group such as chloromethyl, pentafluorobutyl, trifluoropropyl, chlorophenyl, bromoxenyl, chlorotrifluorocyclobutyl, iodophenyl and the like. Further, R ¹ may be any cyanoalkyl group, for example β-cyanoethyl, γ-cyanopropyl, ω-cyanobutyl, β-cyanopropyl, γ-
Examples include cyanobutyl. It is preferred that R ¹ is methyl.

In formula III, R may be any of the groups previously defined for R ¹ , but is preferably methyl. The value of n is preferably sufficient to provide a viscosity in the range of about 100 centipoise to about 500,000 centipoise at 25 ° C. More preferably, the viscosity is in the range of about 2500 centipoise to about 100,000 centipoise at 25 ° C, about 10,0 at 25 ° C.
Most preferably, it is in the range of 00 centipoise to about 50,000 centipoise.

For the purposes of the present invention, mixtures of compounds can be used, and the presence of different types of acyl groups in one or more molecules can also lead to different R's in any molecule or mixture of molecules.
And R ¹ groups may be present. That is, the acyloxysilane can be used alone, or a mixture of two or more different acyloxysilanes can be used. Also, the hydroxylated polysiloxane as a homopolymer,
It may be a copolymer having two or more different siloxane units. Also, for the preparation of the polysiloxane of formula I,
It is also possible to use mixtures of two or more hydroxylated siloxanes.

The production of acyloxy-terminated polydiorganosiloxanes of formula I from acyloxysilanes of formula II and silanol-terminated polydiorganosiloxanes of formula III is well known in the art and is described, for example, in U.S. Pat. No. 3,035,01.
It is described in No. 6.

Condensation catalysts suitable for use in the practice of the present invention include, for example, metal carboxylates ranging from lead to manganese in the metal electrochemical series. Specifically, these metals are lead, tin, nickel, cobalt, iron, cadmium, chromium, zinc and manganese. Most preferably, tin salts are used in the practice of the present invention. The carboxylic acid used to produce the salt of this component can be a monocarboxylic acid or a dicarboxylic acid.

Specific examples of salts that can be used in the present invention include lead naphthenate, cobalt naphthenate, iron 2-ethylhexanoate,
There are lead 2-ethylhexanoate, chromium octoate and lead sebacate. Examples of preferred tin salts are carbomethoxyphenyltin trisberrate, isobutyltin tricerate, dimethyltin dibutyrate, dibutyltin diacetate, dibutyltin dilaurate.

The amount of metal salt of an organic carboxylic acid that can be used in the practice of the present invention depends on how much the cure rate is desired to be increased. In general, the use of these metal salts in amounts of greater than or equal to about 5% by weight, based on the weight of the organopolysiloxane base polymer, has no particular effect. These metal salts are added in an amount of about 0.01 based on the weight of the base polymer.
It is preferably present in an amount of from wt.% To about 2.0 wt.

Other condensation catalysts such as tin oxide, zirconium octoate, antimony octoate are well known in the art and their suitability in the practice of the present invention can be readily determined without undue experimentation. You can be sure.

The novel aspect of the present invention lies in the completely surprising finding that the presence of small amounts of organic amines in conventional acyloxy-functional silicone RTV compositions renders the compositions self-leveling. The amines used to practice the invention are
It can be a primary amine, a secondary amine, a tertiary amine or a mixture thereof. The amine is preferably a primary or secondary amine, particularly preferably a secondary amine.

Examples of effective amines include methylamine, ethylamine, hexylamine, dimethylamine, diethylamine, dihexylamine, trimethylamine, triethylamine, ethylenediamine, propylenediamine, aniline, N-methylaniline, ethanolamine, diphenylamine and the like. One of ordinary skill in the art can determine, without undue experimentation, other amines suitable for use in the practice of the present invention. Di-n as amine
-Hexylamine is most preferred.

In the present invention, the term "amine" also includes guanidine of the formula:

Here, R ² is independently selected from hydrogen and an alkyl group having 1-8 carbon atoms, and R ³ is an alkyl group having 1-8 carbon atoms.

The amount of amine effective to render the composition of the present invention self-leveling is generally greater than or equal to about 25 ppm, preferably greater than or equal to about 40 ppm, and greater than or equal to about 75 ppm, based on the weight of the polydiorganosiloxane component. Is most preferred. Even if it is used in an amount of 1% by weight or more based on the polydiorganosiloxane component, no particular effect can be obtained. Based on the polydiorganosiloxane component, from about 100 ppm to about 200 ppm amine.
Particularly effective results have been obtained when using an amount of
Thus, the range of amines suitable for rendering the compositions of the present invention self-leveling is from about 25 ppm to about 200 ppm based on the polydiorganosiloxane.

It is preferred that the composition of the present invention further comprises known reinforcing fillers such as fumed silica, silica airgel or precipitated silica. Such reinforcing fillers can be prepared by methods known in the art, eg, US Pat.
It can also be treated with a cyclopolysiloxane as disclosed in 8,009 or a silazane as disclosed in US Pat. No. 3,635,743. It is preferable to use untreated or treated fumed silica as the reinforcing filler.

In addition to such reinforcing fillers, further extending fillers, specifically coarse-grained silica, such as diatomaceous earth and quartz powder,
It is often desirable to include metal oxides such as ferric oxide and zinc oxide, asbestos and the like. That is, any of the fillers commonly used in silicone rubbers can be used in the composition of the present invention.

The amount of the filler used can be varied within a wide range according to the intended use of the curable composition. For example, in sealant applications, the curable compositions of the present invention can be used without a filler. For other applications, such as when the curable composition is used to make a binder, a large amount of filler can be used, such as 700 parts by weight per 100 parts by weight of polydiorganosiloxane.

The composition of the present invention can also be used as a construction sealant or caulking compound. Therefore, the exact amount of filler will depend on such factors as the application of the composition, the type of filler used (ie, the density and particle size of the filler), and the like. 10 per 100 parts by weight of polydiorganosiloxane
It is preferred to use a filler in the proportion of ~ 300 parts by weight,
The filler may contain up to about 35 parts by weight reinforcing filler.

In addition to the above components, the composition of the present invention may contain other desired additives such as pigments, light-shielding agents, antioxidants, plasticizers and flame retardants.

The composition of the present invention can be produced simply by mixing the various components under the condition of substantially no humidity. However, for ease of manufacture, a mixture or mixture of all components of the composition except the acyloxysilane is made and then the resulting mixture is kept under reduced pressure to remove water from the mixture and then the acyloxysilane. In addition, it is often convenient to package the composition in a moisture-proof container.

The following examples illustrate the invention and are not intended to limit it in any way. Unless otherwise noted, all parts are by weight.

Example A base composition was prepared from the following ingredients. However, the component (3) "processing aid M, D, T-OH fluid described in Examples of U.S. Pat. No. 3,382,205" means the compound of formula RSi as described above.
It is an organosilicon processing aid obtained by chemically bonding an organosiloxy unit of O _1.5, an organosiloxy unit of formula R ₂ SiO, and an organosiloxy unit of formula R ₃ SiO _0.5 .

(1) 100 parts of silanol-terminated polydimethylsiloxane (18,000 cp) (2) Methyldimethoxysiloxy-terminated polydimethylsiloxane containing 0.5% by weight of dihexylamine in the amount shown in Table 1 (3) 15 parts of USA Processing aids described in the examples of patent 3,382,205 M, D, T-OH fluid (4) Fumed silica treated with 20 parts of methyl tetramer (surface area 200 m ² / g) To each of the above base compositions was added 4.2 parts of a mixture consisting of 79.5 wt% methyltriacetoxysilane, 19.9 wt% di-t-butoxydiacetoxysilane and 0.6 wt% dibutyltin dilaurate.

The rheology properties of these sealants were measured with a vertical Boeing flow jig and found to flow at the flow rates shown in Table 2.

Table 2 Experiment number Flow velocity (1) 1 82 2 79 3 − (2) 4 − (3) 5 82 (1) 4 seconds The number of seconds required to flow.

(2) Flowed 0.4 inches in 3 minutes.

(3) Only 0.1 inch or less was flown in 3 minutes.

Claims (61)

[Claims] 1. A sealant composition comprising (a) an acyloxy-terminated polydiorganosiloxane, (b) an effective amount of a condensation catalyst, and (c) an amount of an amine effective to self-level the composition. 2. An acyloxy-terminated polydiorganosiloxane having the general formula: Wherein A _C is a saturated aliphatic monoacyl group and R and R ¹ are each independently selected from the group consisting of a monovalent hydrocarbon group, a monovalent halogenated hydrocarbon group and a cyanoalkyl group, The composition according to claim 1, wherein n is an integer of 5 or more and a is 0 or 1. 3. The composition of claim 2 wherein the acyloxy-terminated polydiorganosiloxane has a viscosity at 25 ° C of from about 100 centipoise to about 500,000 centipoise. 4. The composition of claim 2 wherein the acyloxy-terminated polydiorganosiloxane has a viscosity at 25 ° C of from about 2,500 centipoise to about 100,000 centipoise. 5. The composition of claim 2 wherein the acyloxy-terminated polydiorganosiloxane has a viscosity at 25 ° C of from about 10,000 centipoise to about 50,000 centipoise. 6. The composition according to claim 1, wherein the condensation catalyst is a carboxylate of a metal selected from lead, tin, nickel, cobalt, iron, cadmium, chromium, zinc and manganese. object. 7. The composition according to claim 6, wherein the metal is tin. 8. A composition according to claim 6 wherein the condensation catalyst is present in an amount of from about 0.01% to about 2.0% by weight based on the weight of the acyloxy terminated polydiorganosiloxane. 9. A composition according to claim 1 wherein the amine is a primary or secondary amine. 10. A composition according to claim 1 wherein the amine is a secondary amine. 11. A composition according to claim 10 wherein the amine is dihexylamine. 12. The composition of claim 1 wherein the amine is present in an amount of about 25 ppm or greater based on the weight of the acyloxy terminated polydiorganosiloxane. 13. The composition of claim 1 wherein the amine is present in an amount of about 40 ppm or greater based on the weight of the acyloxy terminated polydiorganosiloxane. 14. A composition according to claim 1 wherein the amine is present in an amount of about 75 ppm or greater based on the weight of the acyloxy terminated polydiorganosiloxane. 15. The composition of claim 1 wherein the amine is present in an amount of from about 100 ppm to about 200 ppm based on the weight of the acyloxy terminated polydiorganosiloxane. 16. The composition according to claim 1, further comprising a filler. 17. The composition according to claim 16, wherein the filler is a reinforcing filler or a treated reinforcing filler. 18. A composition according to claim 17, wherein the filler is fumed silica or treated fumed silica. 19. A process comprising: (a) mixing an acyloxy-terminated polydiorganosiloxane, (b) an effective amount of a condensation catalyst, and (c) an anhydrous amount of an amine in an amount effective to self-level the composition. A method for producing a sealant composition. 20. The acyloxy-terminated polydiorganosiloxane has the general formula: Wherein A _C is a saturated aliphatic monoacyl group and R and R ¹ are each independently selected from the group consisting of a monovalent hydrocarbon group, a monovalent halogenated hydrocarbon group and a cyanoalkyl group. 20. The method according to claim 19, wherein n is an integer of 5 or more and a is 0 or 1. 21. The method of claim 20, wherein the acyloxy-terminated polydiorganosiloxane has a viscosity at 25 ° C. of from about 100 centipoise to about 500,000 centipoise. 22. The method according to claim 19, wherein the amine is a primary amine or a secondary amine. 23. The method of claim 19 wherein the amine is a secondary amine. 24. The method of claim 23, wherein the amine is dihexylamine. 25. The method of claim 19 wherein the amine is present in an amount of about 25 ppm or greater based on the weight of the acyloxy terminated polydiorganosiloxane. 26. The method of claim 19 wherein the amine is present in an amount of about 40 ppm or greater based on the weight of the acyloxy terminated polydiorganosiloxane. 27. The method of claim 19 wherein the amine is present in an amount of about 75 ppm or greater based on the weight of the acyloxy terminated polydiorganosiloxane. 28. The method of claim 19 further comprising the step of mixing a filler. 29. The method according to claim 28, wherein the filler is a reinforcing filler or a treated reinforcing filler. 30. The method according to claim 29, wherein the filler is fumed silica or treated fumed silica. 31. (a) a silanol-terminated polydiorganosiloxane, (b) about 1 mole or more of a polyacyloxysilane per mole of silicon-bonded hydroxyl groups of (a), (c) an effective amount of a condensation catalyst, and (d). A sealant composition comprising an amine in an amount effective to self-level the composition. 32. The silanol terminated polydiorganosiloxane has the general formula: And R in the formula are each independently a monovalent hydrocarbon group,
32. The composition according to claim 31, which is selected from the group consisting of monovalent halogenated hydrocarbon groups and cyanoalkyl, and n is an integer of 5 or more. 33. The composition of claim 32 wherein the silanol-terminated polydiorganosiloxane has a viscosity at 25 ° C of from about 100 centipoise to about 500,000 centipoise. 34. The composition of claim 32 wherein the silanol-terminated polydiorganosiloxane has a viscosity at 25 ° C of from about 2,500 centipoise to about 100,000 centipoise. 35. The composition of claim 32, wherein the silanol terminated polydiorganosiloxane has a viscosity at 25 ° C. of from about 10,000 centipoise to about 50,000 centipoise. 36. The polyacyloxysilane has the general formula: (R ¹ ) aSi (OA _C ) _4- a, wherein A _C is a saturated aliphatic monoacyl group and R ¹ is independently monovalent. Selected from the group consisting of hydrocarbon groups, monovalent halogenated hydrocarbon groups and cyanoalkyl groups,
32. The composition according to claim 31, wherein a is 0 or 1. 37. The composition of claim 31, wherein the condensation catalyst is a carboxylate of a metal in the range of lead to manganese in the electrochemical series of metals. 38. The composition according to claim 37, wherein the metal is tin. 39. The composition of claim 37, wherein the condensation catalyst is present in an amount of about 0.01 wt% to about 2.0 wt% based on the weight of silanol terminated polydiorganosiloxane. 40. The composition according to claim 31, wherein the amine is a primary amine or a secondary amine. 41. The composition of claim 31, wherein the amine is a secondary amine. 42. The composition of claim 41, wherein the amine is dihexylamine. 43. The composition of claim 31, wherein the amine is present in an amount of greater than or equal to about 25 ppm based on the weight of silanol terminated polydiorganosiloxane. 44. The composition of claim 31, wherein the amine is present in an amount of about 40 ppm or greater based on the weight of silanol terminated polydiorganosiloxane. 45. The composition of claim 31, wherein the amine is present in an amount of at least about 75 ppm based on the weight of silanol terminated polydiorganosiloxane. 46. The composition of claim 31, wherein the amine is present in an amount of about 100 ppm to about 200 ppm based on the weight of silanol terminated polydiorganosiloxane. 47. The composition of claim 31, further comprising a filler. 48. The composition according to claim 47, wherein the filler is a reinforcing filler or a treated reinforcing filler. 49. The composition according to claim 48, wherein the filler is fumed silica or treated fumed silica. 50. (a) silanol terminated polydiorganosiloxane, (b) per mole of silicon-bonded hydroxyl groups of (a),
Preparation of a sealant composition comprising: mixing about 1 mole or more of a polyacyloxysilane, (c) an effective amount of a condensation catalyst, and (d) an amount of an amine in an anhydrous state effective to self-level the composition. Method. 51. The silanol terminated polydiorganosiloxane has the general formula: And R in the formula are each independently a monovalent hydrocarbon group,
51. The method according to claim 50, wherein n is an integer of 5 or more, selected from the group consisting of monovalent halogenated hydrocarbon groups and cyanoalkyl. 52. The method of claim 51, wherein the silanol terminated polydiorganosiloxane has a viscosity at 25 ° C. of about 100 centipoise to about 500,000 centipoise. 53. The method of claim 50, wherein the amine is a primary amine or a secondary amine. 54. The method of claim 50, wherein the amine is a secondary amine. 55. The method of claim 54, wherein the amine is dihexylamine. 56. The method of claim 50, wherein the amine is present in an amount of about 25 ppm or greater based on the weight of silanol terminated polydiorganosiloxane. 57. The method of claim 50, wherein the amine is present in an amount of about 40 ppm or greater based on the weight of the silanol terminated polydiorganosiloxane. 58. The method of claim 50, wherein the amine is present in an amount of at least about 75 ppm based on the weight of silanol terminated polydiorganosiloxane. 59. The method of claim 50, further comprising the step of mixing a filler. 60. The method according to claim 59, wherein the filler is a reinforcing filler or a treated reinforcing filler. 61. The method of claim 60, wherein the filler is fumed silica or treated fumed silica.