US5063254A
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US
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MTQ/polysiloxane hybrid resins, method of making the same, and coating/potting compositions containing the same
Assignee: Henkel Loctite Corp
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Filing: 1989-11-27
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Granted: 1991-11-05
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Expires: 2009-11-27
Abstract
Abstract A polysiloxane comprising a linear polydiorganosiloxane chain joined at one terminus to an acrylic-functional end group, and joined at its other end to a cross-linked MTQ moiety comprising a multiplicity of monofunctional siloxane units (M), trifunctional siloxane units (T), and tetrafunctional siloxane units (Q), wherein the concentration ratio of M units to the sum of T units and Q units, M/(T+Q), in the MTQ moiety is from about 0.55 to about 0.75, and wherein the number of siloxy repeating units in the linear polydiorganosiloxane chain is from 25 to 1,000. The M and or /T units may also contain (meth)acrylate groups. The MTQ/silicone hybrid resins of the invention are curable by UV radiation, to provide high tensile strength silicone compositions having utility in potting and conformal coating apllications.
Inventors
- 👤 Steven T. Nakos
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 03:11
CPC Classifications
C; C08; C08G; C08G77/00; C08G77/42; C08G77/44; C08G77/04; C08G77/20; Y; Y10; Y10T; Y10T428/00; Y10T428/31504; Y10T428/31652; Y10T428/31663
Claims Analysis
Total Claims: 30
Claim 1
Independent Claim
185 words
A polysiloxane, comprising: (I) an MTQ moiety having a plurality of pendant hydroxy groups and comprising a multiplicity of monofunctional siloxane units (M), ##STR17## trifunctional siloxane units (T), ##STR18## and tetrafunctional siloxane units (Q), ##STR19## wherein: p has a value of 0.5 when the associated oxygen atom is bonded to another silicon atom, and a value of 1 when the associated oxygen atom is bonded to other than a silicon atom, with the proviso that at least one p in each T and Q unit has a value of 0.5; each R is independently selected from the group consisting of alkyl, aryl, alkaryl, aralkyl, haloalkyl, (meth)acryloxyalkyl, and (meth)acryloxyalkenyl; the concentration ratio of M units to the sum of T and Q units, M/(T+Q), in the MTQ moiety is from about 0.55 to about 0.75; and (II) covalently bonded to the MTQ moiety, a diorganosiloxane polymer of the formula: ##STR20## wherein: A is an acrylic-functional end group; R 1 and R 2 are each independently selected from the group consisting of alkyl, aryl, alkaryl, aralkyl, haloalkyl, (meth)acryloxyalkyl, and (meth)acryloxyalkenyl; and n is from 25 to 1000.
Claim 2
Dependent Claim
185 words
A polysiloxane, comprising: (I) an MTQ moiety having a plurality of pendant hydroxy groups and comprising a multiplicity of monofunctional siloxane units (M), ##STR17## trifunctional siloxane units (T), ##STR18## and tetrafunctional siloxane units (Q), ##STR19## wherein: p has a value of 0.5 when the associated oxygen atom is bonded to another silicon atom, and a value of 1 when the associated oxygen atom is bonded to other than a silicon atom, with the proviso that at least one p in each T and Q unit has a value of 0.5; each R is independently selected from the group consisting of alkyl, aryl, alkaryl, aralkyl, haloalkyl, (meth)acryloxyalkyl, and (meth)acryloxyalkenyl; the concentration ratio of M units to the sum of T and Q units, M/(T+Q), in the MTQ moiety is from about 0.55 to about 0.75; and (II) covalently bonded to the MTQ moiety, a diorganosiloxane polymer of the formula: ##STR20## wherein: A is an acrylic-functional end group; R 1 and R 2 are each independently selected from the group consisting of alkyl, aryl, alkaryl, aralkyl, haloalkyl, (meth)acryloxyalkyl, and (meth)acryloxyalkenyl; and n is from 25 to 1000.
Claim 3
Dependent Claim
37 words
A polysiloxane according to claim 1, wherein A is selected from the group consisting of: ##STR21## and (ii) (alkyl)acryloxyalkenyl selected from the group consisting of: ##STR22## and isomeric mixtures thereof; wherein R 3 is H or alkyl.
Claim 4
Dependent Claim
13 words
A polysiloxane according to claim 1, wherein n is from 100 to 1000.
Claim 5
Dependent Claim
37 words
A polysiloxane according to claim 1, comprising silanol groups in sufficient quantity relative to the number of acrylic functional groups present, to render the polysiloxane self-curable by exposure to UV radiation in the presence of a photoinitiator.
Claim 6
Dependent Claim
18 words
A UV curable composition comprising a polysiloxane according to claim 1 and a UV photoinitiator for said polysiloxane.
Claim 7
Dependent Claim
13 words
A curable composition according to claim 5, wherein said photoinitiator is alpha, alpha',diethoxyacetophenone.
Claim 8
Dependent Claim
17 words
A UV cured silicone composition formed by UV curing of the UV curable composition of claim 5.
Claim 9
Dependent Claim
15 words
A polysiloxane according to claim 1, wherein M/(T+Q) is from about 0.60 to about 0.70.
Claim 10
Dependent Claim
11 words
A polysiloxane according to claim 1, wherein M/(T+Q) is about 0.67.
Claim 11
Dependent Claim
25 words
A polysiloxane according to claim 1, wherein the MTQ moiety has a concentration of (meth)acrylic functionality of from about 0.60 to about 1.40 meq/gm solid.
Claim 12
Dependent Claim
19 words
A polysiloxane according to claim 1 wherein the diorganosiloxane polymer has a molecular weight of from 20,000 to 40,000.
Claim 13
Dependent Claim
14 words
A polysiloxane according to claim 1, wherein R 1 and R 2 are alkyl.
Claim 14
Dependent Claim
14 words
A polysiloxane according to claim 1, wherein R 1 and R 2 are methyl.
Claim 15
Dependent Claim
15 words
A polysiloxane according to claim 1, wherein the MTQ moiety contains no D siloxane units.
Claim 16
Dependent Claim
83 words
A graft MTQ/silicone resin formed by reacting (i) an MTQ moiety having pendant silanol functionality, with (ii) a linear diorganosiloxane polymer having (A) from 25 to 1000 diorganosiloxy repeating units, (B) an acrylic functional end group at one end of the linear diorganosiloxane polymer, and (C) a chlorosilane functional end group at a second end of the linear diorganosiloxane polymer, which is reactive with the pendant silanol functionality of the MTQ moiety to covalently bond the linear diorganosiloxane polymer to the MTQ moiety.
Claim 17
Dependent Claim
83 words
A graft MTQ/silicone resin formed by reacting (i) an MTQ moiety having pendant silanol functionality, with (ii) a linear diorganosiloxane polymer having (A) from 25 to 1000 diorganosiloxy repeating units, (B) an acrylic functional end group at one end of the linear diorganosiloxane polymer, and (C) a chlorosilane functional end group at a second end of the linear diorganosiloxane polymer, which is reactive with the pendant silanol functionality of the MTQ moiety to covalently bond the linear diorganosiloxane polymer to the MTQ moiety.
Claim 18
Independent Claim
72 words
A method of making an MTQ/silicone hybrid resin, comprising the steps of: (a) forming a linear polydiorganosiloxane having acrylic and chloro end groups, and comprising from 25 to 1,000 diorganosiloxy repeating units; (b) hydrolyzing tetraalkyl orthosilicate, an acrylic-functional trialkoxysiloxane, and a chlorotrialkylsilane, to form an MTQ resin comprising silanol functionality; and (c) reacting chloro functionality of said linear polydiorganosiloxane with silanol functionality of said MTQ resin, to form an MTQ/silicone hybrid resin.
Claim 19
Independent Claim
72 words
A method of making an MTQ/silicone hybrid resin, comprising the steps of: (a) forming a linear polydiorganosiloxane having acrylic and chloro end groups, and comprising from 25 to 1,000 diorganosiloxy repeating units; (b) hydrolyzing tetraalkyl orthosilicate, an acrylic-functional trialkoxysiloxane, and a chlorotrialkylsilane, to form an MTQ resin comprising silanol functionality; and (c) reacting chloro functionality of said linear polydiorganosiloxane with silanol functionality of said MTQ resin, to form an MTQ/silicone hybrid resin.
Claim 20
Dependent Claim
15 words
A method according to claim 16, wherein the MTQ resin contains no difunctional siloxane constituent.
Claim 21
Dependent Claim
26 words
A method according to claim 16, further comprising mixing the MTQ/silicone hybrid resin with methanol and heat aging the resulting mixture, to stabilize the viscosity thereof.
Claim 22
Dependent Claim
30 words
A method according to claim 16, comprising carrying out the hydrolysis for sufficient time to form an MTQ resin having a molecular weight of from about 1000 to about 10,000.
Claim 23
Dependent Claim
35 words
A method according to claim 16, wherein the mole ratio of M units to the sum of T units and Q units, M/(T+Q), in said MTQ/silicone hybrid resin is from about 0.55 to about 0.75.
Claim 24
Dependent Claim
29 words
A method according to claim 16, wherein said MTQ resin comprises (meth)acrylate functionality at a concentration of from about 0.28 meq/gram to about 2.54 meq/gram of said MTQ resin.
Claim 25
Dependent Claim
29 words
A method according to claim 16, wherein said MTQ resin comprises (meth)acrylate functionality at a concentration of from about 0.60 meq/gram to about 1.4 meq/gram of said MTQ resin.
Claim 26
Dependent Claim
20 words
A method according to claim 16, wherein said acrylic-functional trialkoxysilane is selected from the group consisting of acryloxypropenyltrimethoxysilane and methacryloxypropyltrimethoxysilane.
Claim 27
Dependent Claim
39 words
A method according to claim 16, wherein the reaction of said MTQ resin and said linear polydiorganosiloxane is carried out for sufficient time and under sufficient conditions to react a majority of hydroxyl functional groups of said MTQ resin.
Claim 28
Dependent Claim
69 words
A process of potting or conformally coating a substrate element, comprising: (1) mixing a polysiloxane according to claim 1 with an effective amount of UV photoinitiator to form a resulting UV curable composition; (2) applying said UV curable composition to said substrate element to pot or conformally coat said substrate; and (3) exposing the potted or coated substrate element to sufficient UV radiation to cure said UV curable composition.
Claim 29
Dependent Claim
13 words
A process according to claim 25, wherein said UV photoinitiator is alpha, alpha'-diethoxyacetophenone.
Claim 30
Dependent Claim
25 words
A potted or conformally coated article, comprising a substrate element potted or conformally coated with a cured composition according to the process of claim 25.
References Cited (Backward Citations)
US2486162A
Cited
US3865588A
Cited
US3782940A
Cited
US4293671A
Cited
US4267298A
Cited
US4625007A
Cited
US4575545A
Cited
US4503208A
Cited
US4728709A
Cited
US4504629A
Cited
US4699802A
Cited
US4529629A
Cited
WO1986000322A1
Cited
US4575546A
Cited
US4585670A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-11-04 | 1995-05-06 | 1995-11-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-11-04 | 1999-05-06 | 1999-11-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-11-04 | 2003-05-06 | 2003-11-05 | $7700.00 | Window Closed / Lapsed |