CA1109590A - Polysiloxane release coating compositions and method for preparing same - Google Patents
Polysiloxane release coating compositions and method for preparing sameInfo
- Publication number
- CA1109590A CA1109590A CA333,894A CA333894A CA1109590A CA 1109590 A CA1109590 A CA 1109590A CA 333894 A CA333894 A CA 333894A CA 1109590 A CA1109590 A CA 1109590A
- Authority
- CA
- Canada
- Prior art keywords
- group
- alkyl
- diorganopolysiloxane
- crosslinking agent
- carbon atoms
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Landscapes
- Paints Or Removers (AREA)
- Compositions Of Macromolecular Compounds (AREA)
Abstract
Abstract of the Disclosure - Silicon-based release coating compositions that are stable at ambient temperature, cure readily at temperatures from 100 to 200° C. and do not contain significant amounts of organic solvents, can be pre-pared using a diorganopolysiloxane, a crosslinking agent and a catalytically effective amount of a monoorganotin compound that is soluble in or miscible with the polysiloxane and the crosslinking agent in the absence of any additional solvents.
Description
RS~ 7~ )~K
~.
POLYSILOXANE RELEASE COATING COMPOSITIONS AND
METHOD FOR PREPARING SAl'~lE
BACKGROUND OF_THE INVENTION
This invention relates to improved silicone-based surface treating compositions, and more particularly to such compositions containing a diorganopolysiloxane, a cross-linking a~ent and an organotin compound as the curing catalyst.
It is well known to impart non-adhesive or release properties to papers formed ~rom natural or synthetic fibers by coating the paper with a curable liquid composition con-taining a diorganopolysiloxane with two terminal hydroxyl groups and a crosslinking agent. ~he reaction between these two materials to form a solid film exhibiting the desired release properties can be catalyzed by a variety of compounds, including metal salts of carboxylic acids. One of the more pre~erred classes of catalysts are diorganotin carboxylates such as dibutyltin dilaurate and dibutyltin di(2-ethylhexoate).
United States Patent No. 3,799,919 teaches that while these diorganotin compounds are effective catalysts, the useful li~e o~ a coating bath containing these catalysts is as short as one hour. This would be undesirable for a commercial scale coating operation. The patent discloses that the useful life o.f the bath can be extended to as much as 10 days by including an amide such as N,N-dimethylformamide in the treating bath.
An additional disadvantage of many diorganotin carboxylates is that they are solid materials which are insoluble in the mixture of diorganopolysiloxane and crosslinking agent.
Hydrocarbon solvents such as toluene and xylene are required to ~orm a homogenous liquld composition containing the two reactants and the catalyst. The use o~ solvents is undesirable for a number of reasons. In addition to increasing the cost o~ the ~oating ~ormulation, removal of the solvents during curing of the coating requires energy in the form of heat and increases atmospheric pollution unless costly solvent recovery equipment is employed.
It has now been found that the problems of compati-bility of many diorganotin compounds with silicon-containing reactants and the short "pot" life of these catalyzed compositions are avoided when the diorganotin compound is replaced by a monoorganotin compound.
An objective of this invention is to provide solvent-free compositions useful for preparing sllicon release coatings on a variety of substrates, including paper. The compositions are stable at ambient temperature for up to 24 hours or longer but react relatively rapidly at temperatures of above about 100C to yield the desired reIease coating.
: ~ RS ( /~7 7~ ) MX
POLYSILOXANE RELEASE COATING COMPOSITIOMS AND
METHOD FOR PREPARING SAME
SUMMARY OF THE INVENTION
This invention provides an improved surface treating composition comprising 100 parts by weight of a linear silanol-terminated diorganopolysiloxane having at least two sllicon~
bonded hydroxyl groups not attached to the same silicon atom and wherein the hydrocarbon groups of the diorganopolysilo~ane are selected from the group consisting of alkyl, aryl, aralkyl, alkaryl, alkenyl, cycloalkyl and cycloalkenyl, 1 to 20 parts by weight o~ a crosslinking agent selected from the group consisting of organohydrogenpolysiloxanesg silicic acid esters, alkyltrialkoxysilanes and:partially h~drolyzed alkyltri-alkoxysilanes and a catalytically effective amount of an organotin compound as the catalyst for the reaction of the dlorganopolysiloxane with the crosslinking agent. The improvement resides in the presence as sald catalyst of` a mono-organotin compound that in catalytic amounts is soluble in or miscible with the combination of said diorganopolysiloxane and said crosslinking agent in the absence of additional solvents. The hydrocarbon group bonded to the tin atom of the monoorganotin compound is selected from the group consisting of alkyl, cycloalkyl, aryl, aralkyl and alkaryl wherein the number of carbon atoms in any alkyl residue is from 1 to 12.
" ~ -, ' ' : .
, 5~
In another aspect, the invention provides a method o pre-paring polysiloxane release coating compositions that are stable at ambien~ temperature, said method comprising 1) orming a homogeneous composition wherein the reactive components consist essentially o.f 100 parts by weight of a linear diorganopolysiloxane having at least two silicon-bonded hydrox~l groups not attached to the same silicon atom and wherein the hydrocarbon group of the diorganopolysiloxane are sel- -ected from the group consisting of alkyl, aryl, aralkyl, alkaryl, alkenyl, cycloalkyl and cycloalkenyl~ 1 to 20 parts by weight of a crosslinking agent selected rom the group consisting of organohydrogenpoly-siloxanes, silicic acid esters, alkyl~rialkoxysilanes and partially hydrolyzed alkyltrialkoxysilanes and a catalytically effective amount of a momoorganotin compound that in catalytic amounts is soluble or miscible with the mixture of said diorganopolysiloxane and said crosslinking agent, 2) maintaining the resultant coating composition at ambient temperature for a minimum of 2~ hours prior ~o applying said composition to a substrate and curing said composition at a temperature of from 100 to 200C as required to form a release coating.
- 3a -. .
RS(/~ 7~ )MK
I POLYSILOXANE RELEASE COATING COMPOSITIONS AND
I METHOD FOR P~EPARING SAME
..
DETAILED DESCRIPTION OF THE INVENTION
The advantages of the present monoorganotin compounds as catalysts for polysiloxane release coatings re7ative to the diorganotin compounds of the prior art are 1) the compatibility of catalytically effective amounts of the preSent catalysts ¦ With liquid compositions containing a polyorganosiloxane and ¦ a 3ilicon-based crosslinking or curing agent such as an alkyl~
¦ trialkoxysilane or a partial hydrolyzate thereof, ~) the long-¦ term stability of the aforementioned liquid Compositions at ¦ ambient temperature and 3) the relatively short heating time ¦ requ~red to cure these compositions at temperatures above about 100C. Representative compositions cure in from 20 to 30 minute S
at temperatures of from 100 to 120C.
The catalysts Of thiS invention exhibit the general l formula RSnX3 wherein R is alkyl, cycloalkyl~ aryl~ alkaryl l or aralkyl. Any alkyl portion present in R contains from 1 to 12 carbon atoms. X represents any of the conventlonal anionic groups, the only requirement being that the presence of X does not adversely affect the solubility at the desired concentration of the monoorganotln compound in a mixture containing the hydroxyl-terminated polyorganosiloxane and the curing agent. The concentration of monoorganotin compound that Will provide the desired curing time is dependent upon curing temperature in addition to the types of diorganopolysiloxane and crosslinking agent employed. It is therefore difficult to precisely define one concentration range that will be applicable ~ _4_ .
to all of the possible combinations within the scope of this l invention. In some compositions a catalyst concentration of 1%, ¦ based on total composition weight, may be sufficient. Less l reactive compounds may require up to 10% by weight of catalyst to achieve a reasonable curing rate at the desired temperature.
Among the classes of monoorganotin compounds that meet the criterion of compatibility are compounds wherein X of the foregoing ~ormula represents chlorine, bromine, iodine, carboxyl (-OOCR ), mercapto (-SR ) or carboalkoxythio (-SR COOR ). R is selected from the same group of hydrocarbon residues as R and R is alkylene and contalns ~rom 1 to 4 carbon atoms. X can also represent a residue of a half ester of maleic or other dibasic acid wherein the hydrocarbon portion of the esterifying alcohol contains from 1 to 20 carbon atoms.
Preferred catalysts are disclosed in the accompanying examples.
The diorganopolysiloxane component o~ the present compositions can be any liquid exhibiting the general ~ormula ¦ R
HO-- -Si-O - H
wherein R is a hydrocarbon group and n represents the number o~
repeating units, The actual value of n is from 50 ko 100.
Above this upper limit the viscosity of the resultant compo-sition is usually too high ~or application as a coating without the use of organic solvents, which are undesirable for reasons previously mentioned.
~ The second reactive component of the present coatiro ¦ composition is a crosslinking agent ~or the a~orementioned ¦ diorganopolysilo~ane. Conventional crosslinking agents include ¦ organohydrogenpolysiloxanes, silicic acid esters, alkyltri-¦ alkoxysilanes and partial hydrolyzates. The trialkoxysilanes ¦ are a preferred class of curing agents and include methyl-¦ trimethoxysilane, methyltriethoxysilane and self-condensation products thereof. ~he alkoxy groups preferably contain less l than 10 carbon atoms. The amount of crosslinking agent ¦ employed in conventional formulations is usually from 1 to 2070 based on the weight of the diorganopolysiloxane.
Silicic acid esters that are useful crosslinking agents include monomeric and polymeric lower alkyl esters of l orthosilicic acid, such as the methyl, ethyl, butyl and amyl l esters. Tetraethyl orthosilicate is one of the commercially available esters.
The present liquid coating compositions can be applied to a variety of substrates, particularly paper and l other cellulosic materials, using any of the conventional ¦ methods, including the use of coatlng knives or by dipping or spraying. The resultant coating is then cured ~y heating the coated`suhstrate to temperatures of fro~ lQQ to about 200C for ~rom 2 to 35 minutes, depending upon the thickness of the coating and the concentration of catalyst.
In addition to the diorganopolysiloxane, cross-linking agent and catalyst the present coating compositions may contain small amounts of organic solvents to reduce the viscosi~y of the coating composition. Non-volatile additives such as pigments, thixotroplc agents, antioxidants, fillers and adhesion promoters may also be present.
_~
.
:
-- ~
The following examples disclose preferred embodimer,ts o~ the presen~ release coating compositions and demonstrate the advantages of compatibility and storage stability which l characterize these compositions. All par~s and percentages ¦ are by weight unless otherwise specified.
The curable paper release coating employed contained a dimethylpolysiloxane and a methylhydrogenpolysiloxane. This l composition is available under the trademark Syl-Off~ 291 from the Dow-Corning Corporation. A 90 gram portion of this composition was combined with 0.80 g of butyltin tris(lauryl maleate) and a portion o~ the resultant homogeneous mixture was then poured into two metal dishes. The amount of liquid used was ~ust enough to cover the bottom of the dish. One of the dishes was then heated in an oven maintained at 100C and the second dish was heated in an oven at 120C. The dishes were withdrawn periodically and the layer of solidified polymer was tested to determine whether it was completely cured. The test consisted of applying a piece of cellophane tape to the surface of the polymer. The polymer wàs considered to be completely cured when the tape did not adhere to it. Curing was completed a~ter 18 minutes at 120C and after 35 minutes at 100C.
The portion of the original liquid composition which was not placed in dishes was allowed to stand for 24 hours at ambient temperature. The viscosity of the composition, measured using a Brookfield viscometer~ increased from 680o centipoises ~o 11,600 centipoises during this period. The latter value was considered within acceptable limits for a release coating precursor.
The test procedure described in the preceding example was repeated using 0.45 g of butyltin trioctoate and the same amount of the curable mixture (Syl-Off~ 291). Complete curing required 14 minutes at 100C and 10 minutes at 120C.
The mixture of silicon compounds and catalyst remained fluid for 24 hours at ambient temperature.
.
~.
POLYSILOXANE RELEASE COATING COMPOSITIONS AND
METHOD FOR PREPARING SAl'~lE
BACKGROUND OF_THE INVENTION
This invention relates to improved silicone-based surface treating compositions, and more particularly to such compositions containing a diorganopolysiloxane, a cross-linking a~ent and an organotin compound as the curing catalyst.
It is well known to impart non-adhesive or release properties to papers formed ~rom natural or synthetic fibers by coating the paper with a curable liquid composition con-taining a diorganopolysiloxane with two terminal hydroxyl groups and a crosslinking agent. ~he reaction between these two materials to form a solid film exhibiting the desired release properties can be catalyzed by a variety of compounds, including metal salts of carboxylic acids. One of the more pre~erred classes of catalysts are diorganotin carboxylates such as dibutyltin dilaurate and dibutyltin di(2-ethylhexoate).
United States Patent No. 3,799,919 teaches that while these diorganotin compounds are effective catalysts, the useful li~e o~ a coating bath containing these catalysts is as short as one hour. This would be undesirable for a commercial scale coating operation. The patent discloses that the useful life o.f the bath can be extended to as much as 10 days by including an amide such as N,N-dimethylformamide in the treating bath.
An additional disadvantage of many diorganotin carboxylates is that they are solid materials which are insoluble in the mixture of diorganopolysiloxane and crosslinking agent.
Hydrocarbon solvents such as toluene and xylene are required to ~orm a homogenous liquld composition containing the two reactants and the catalyst. The use o~ solvents is undesirable for a number of reasons. In addition to increasing the cost o~ the ~oating ~ormulation, removal of the solvents during curing of the coating requires energy in the form of heat and increases atmospheric pollution unless costly solvent recovery equipment is employed.
It has now been found that the problems of compati-bility of many diorganotin compounds with silicon-containing reactants and the short "pot" life of these catalyzed compositions are avoided when the diorganotin compound is replaced by a monoorganotin compound.
An objective of this invention is to provide solvent-free compositions useful for preparing sllicon release coatings on a variety of substrates, including paper. The compositions are stable at ambient temperature for up to 24 hours or longer but react relatively rapidly at temperatures of above about 100C to yield the desired reIease coating.
: ~ RS ( /~7 7~ ) MX
POLYSILOXANE RELEASE COATING COMPOSITIOMS AND
METHOD FOR PREPARING SAME
SUMMARY OF THE INVENTION
This invention provides an improved surface treating composition comprising 100 parts by weight of a linear silanol-terminated diorganopolysiloxane having at least two sllicon~
bonded hydroxyl groups not attached to the same silicon atom and wherein the hydrocarbon groups of the diorganopolysilo~ane are selected from the group consisting of alkyl, aryl, aralkyl, alkaryl, alkenyl, cycloalkyl and cycloalkenyl, 1 to 20 parts by weight o~ a crosslinking agent selected from the group consisting of organohydrogenpolysiloxanesg silicic acid esters, alkyltrialkoxysilanes and:partially h~drolyzed alkyltri-alkoxysilanes and a catalytically effective amount of an organotin compound as the catalyst for the reaction of the dlorganopolysiloxane with the crosslinking agent. The improvement resides in the presence as sald catalyst of` a mono-organotin compound that in catalytic amounts is soluble in or miscible with the combination of said diorganopolysiloxane and said crosslinking agent in the absence of additional solvents. The hydrocarbon group bonded to the tin atom of the monoorganotin compound is selected from the group consisting of alkyl, cycloalkyl, aryl, aralkyl and alkaryl wherein the number of carbon atoms in any alkyl residue is from 1 to 12.
" ~ -, ' ' : .
, 5~
In another aspect, the invention provides a method o pre-paring polysiloxane release coating compositions that are stable at ambien~ temperature, said method comprising 1) orming a homogeneous composition wherein the reactive components consist essentially o.f 100 parts by weight of a linear diorganopolysiloxane having at least two silicon-bonded hydrox~l groups not attached to the same silicon atom and wherein the hydrocarbon group of the diorganopolysiloxane are sel- -ected from the group consisting of alkyl, aryl, aralkyl, alkaryl, alkenyl, cycloalkyl and cycloalkenyl~ 1 to 20 parts by weight of a crosslinking agent selected rom the group consisting of organohydrogenpoly-siloxanes, silicic acid esters, alkyl~rialkoxysilanes and partially hydrolyzed alkyltrialkoxysilanes and a catalytically effective amount of a momoorganotin compound that in catalytic amounts is soluble or miscible with the mixture of said diorganopolysiloxane and said crosslinking agent, 2) maintaining the resultant coating composition at ambient temperature for a minimum of 2~ hours prior ~o applying said composition to a substrate and curing said composition at a temperature of from 100 to 200C as required to form a release coating.
- 3a -. .
RS(/~ 7~ )MK
I POLYSILOXANE RELEASE COATING COMPOSITIONS AND
I METHOD FOR P~EPARING SAME
..
DETAILED DESCRIPTION OF THE INVENTION
The advantages of the present monoorganotin compounds as catalysts for polysiloxane release coatings re7ative to the diorganotin compounds of the prior art are 1) the compatibility of catalytically effective amounts of the preSent catalysts ¦ With liquid compositions containing a polyorganosiloxane and ¦ a 3ilicon-based crosslinking or curing agent such as an alkyl~
¦ trialkoxysilane or a partial hydrolyzate thereof, ~) the long-¦ term stability of the aforementioned liquid Compositions at ¦ ambient temperature and 3) the relatively short heating time ¦ requ~red to cure these compositions at temperatures above about 100C. Representative compositions cure in from 20 to 30 minute S
at temperatures of from 100 to 120C.
The catalysts Of thiS invention exhibit the general l formula RSnX3 wherein R is alkyl, cycloalkyl~ aryl~ alkaryl l or aralkyl. Any alkyl portion present in R contains from 1 to 12 carbon atoms. X represents any of the conventlonal anionic groups, the only requirement being that the presence of X does not adversely affect the solubility at the desired concentration of the monoorganotln compound in a mixture containing the hydroxyl-terminated polyorganosiloxane and the curing agent. The concentration of monoorganotin compound that Will provide the desired curing time is dependent upon curing temperature in addition to the types of diorganopolysiloxane and crosslinking agent employed. It is therefore difficult to precisely define one concentration range that will be applicable ~ _4_ .
to all of the possible combinations within the scope of this l invention. In some compositions a catalyst concentration of 1%, ¦ based on total composition weight, may be sufficient. Less l reactive compounds may require up to 10% by weight of catalyst to achieve a reasonable curing rate at the desired temperature.
Among the classes of monoorganotin compounds that meet the criterion of compatibility are compounds wherein X of the foregoing ~ormula represents chlorine, bromine, iodine, carboxyl (-OOCR ), mercapto (-SR ) or carboalkoxythio (-SR COOR ). R is selected from the same group of hydrocarbon residues as R and R is alkylene and contalns ~rom 1 to 4 carbon atoms. X can also represent a residue of a half ester of maleic or other dibasic acid wherein the hydrocarbon portion of the esterifying alcohol contains from 1 to 20 carbon atoms.
Preferred catalysts are disclosed in the accompanying examples.
The diorganopolysiloxane component o~ the present compositions can be any liquid exhibiting the general ~ormula ¦ R
HO-- -Si-O - H
wherein R is a hydrocarbon group and n represents the number o~
repeating units, The actual value of n is from 50 ko 100.
Above this upper limit the viscosity of the resultant compo-sition is usually too high ~or application as a coating without the use of organic solvents, which are undesirable for reasons previously mentioned.
~ The second reactive component of the present coatiro ¦ composition is a crosslinking agent ~or the a~orementioned ¦ diorganopolysilo~ane. Conventional crosslinking agents include ¦ organohydrogenpolysiloxanes, silicic acid esters, alkyltri-¦ alkoxysilanes and partial hydrolyzates. The trialkoxysilanes ¦ are a preferred class of curing agents and include methyl-¦ trimethoxysilane, methyltriethoxysilane and self-condensation products thereof. ~he alkoxy groups preferably contain less l than 10 carbon atoms. The amount of crosslinking agent ¦ employed in conventional formulations is usually from 1 to 2070 based on the weight of the diorganopolysiloxane.
Silicic acid esters that are useful crosslinking agents include monomeric and polymeric lower alkyl esters of l orthosilicic acid, such as the methyl, ethyl, butyl and amyl l esters. Tetraethyl orthosilicate is one of the commercially available esters.
The present liquid coating compositions can be applied to a variety of substrates, particularly paper and l other cellulosic materials, using any of the conventional ¦ methods, including the use of coatlng knives or by dipping or spraying. The resultant coating is then cured ~y heating the coated`suhstrate to temperatures of fro~ lQQ to about 200C for ~rom 2 to 35 minutes, depending upon the thickness of the coating and the concentration of catalyst.
In addition to the diorganopolysiloxane, cross-linking agent and catalyst the present coating compositions may contain small amounts of organic solvents to reduce the viscosi~y of the coating composition. Non-volatile additives such as pigments, thixotroplc agents, antioxidants, fillers and adhesion promoters may also be present.
_~
.
:
-- ~
The following examples disclose preferred embodimer,ts o~ the presen~ release coating compositions and demonstrate the advantages of compatibility and storage stability which l characterize these compositions. All par~s and percentages ¦ are by weight unless otherwise specified.
The curable paper release coating employed contained a dimethylpolysiloxane and a methylhydrogenpolysiloxane. This l composition is available under the trademark Syl-Off~ 291 from the Dow-Corning Corporation. A 90 gram portion of this composition was combined with 0.80 g of butyltin tris(lauryl maleate) and a portion o~ the resultant homogeneous mixture was then poured into two metal dishes. The amount of liquid used was ~ust enough to cover the bottom of the dish. One of the dishes was then heated in an oven maintained at 100C and the second dish was heated in an oven at 120C. The dishes were withdrawn periodically and the layer of solidified polymer was tested to determine whether it was completely cured. The test consisted of applying a piece of cellophane tape to the surface of the polymer. The polymer wàs considered to be completely cured when the tape did not adhere to it. Curing was completed a~ter 18 minutes at 120C and after 35 minutes at 100C.
The portion of the original liquid composition which was not placed in dishes was allowed to stand for 24 hours at ambient temperature. The viscosity of the composition, measured using a Brookfield viscometer~ increased from 680o centipoises ~o 11,600 centipoises during this period. The latter value was considered within acceptable limits for a release coating precursor.
The test procedure described in the preceding example was repeated using 0.45 g of butyltin trioctoate and the same amount of the curable mixture (Syl-Off~ 291). Complete curing required 14 minutes at 100C and 10 minutes at 120C.
The mixture of silicon compounds and catalyst remained fluid for 24 hours at ambient temperature.
.
Claims (10)
1. In an improved surface treating composition comprising 100 parts by weight of a linear silanol-terminated diorganopolysiloxane having at least two silicon-bonded hydroxyl groups not attached to the same silicon atom and wherein the hydrocarbon groups of the diorganopolysiloxane are selected from the group consisting of alkyl, aryl, aralkyl, alkaryl, alkenyl, cycloalkyl and cycloalkenyl, 1 to 20 parts by weight of a crosslinking agent selected from the group consisting of organohydrogenpolysiloxanes, silicic acid esters, alkyltrialkoxysilanes and partially hydrolyzed alkyltrialkoxy-silanes and a catalytically effective amount of an organotin compound as the catalyst for the reaction of the diorgano-polysiloxane with the crosslinking agent, the improvement that comprises the presence as said catalyst of a monoorganotin compound that in catalytic amounts is soluble in or miscible with the combination of said diorganopolysiloxane and said crosslinking agent in the absence of additional solvents.
2. An improved surface treating composition according to Claim 1 wherein said monoorganotin compound exhibits the general formula RSnX3 wherein R represents a hydrocarbon radical selected from the group consisting of alkyl, cycloalkyl, aryl, alkaryl and aralkyl wherein any alkyl residue contains from 1 to 12 carbon atoms and X represents an anionic group which is soluble in or miscible with the diorganopolysiloxane and said crosslinking agent.
3. An improved surface treating composition according to Claim 2 wherein R is alkyl.
4. An improved surface treating composition according to Claim 2 wherein X is selected from the group consisting of chlorine, bromine, iodine, -OOCR', -OOCCH=CH-COOR', -SR' and -SR"COOR' wherein R' is alkyl and contains from 1 to 20 carbon atoms and R" is alkylene and contains from 1 to 4 carbon atoms.
5. An improved surface treating composition according to Claim 2 wherein said monoorganotin compound is butyltin tris(lauryl maleate) or butyltin trioctoate.
6. A method for preparing polysiloxane release coating compositions that are stable at ambient temperature, said method comprising 1) forming a homogeneous composition wherein the reactive components consist essentially of 100 parts by weight of a linear diorganopolysiloxane having at least two silicon-bonded hydroxyl groups not attached to the same silicon atom and wherein the hydrocarbon group of the diorganopolysiloxane are selected from the group consisting of alkyl, aryl, aralkyl, alkaryl, alkenyl, cycloalkyl and cycloalkenyl, 1 to 20 parts by weight of a crosslinking agent selected from the group consisting of organohydrogenpoly-siloxanes, silicic acid esters, alkyltrialkoxysilanes and partially hydrolyzed alkyltrialkoxysilanes and a catalytically effective amount of a monoorganotin compound that in catalytic amounts is soluble or miscible with the mixture of said diorganopolysiloxane and said crosslinking agent, 2) maintaining the resultant coating composition at ambient temperature for a minimum of 24 hours prior to applying said composition to a substrate and curing said composition at a temperature of from 100 to 200°C as required to form a release coating.
7. A method according to Claim 6 wherein said monoorganotin compound exhibits the general formula RSnX3 wherein R represents a hydrocarbon radical selected from the group consisting of alkyl, cycloalkyl, aryl, alkaryl and aralkyl wherein any alkyl residue contains from 1 to 12 carbon atoms and X represents an anionic group which is soluble in or miscible with the mixture of said diorganopolysiloxane and said crosslinking agent.
8. A method according to Claim 7 wherein R is alkyl.
9. A method according to Claim 7 wherein X is selected from the group consisting of chlorine, bromine, iodine, -OOCR', -OOCCH=CH-COOR', -SR' and -SR"COOR' wherein R' is alkyl and contains from 1 to 20 carbon atoms and R" is alkylene and contains from 1 to 4 carbon atoms.
10. A method according to Claim 7 wherein said monoorganotin compound is butyltin tris(lauryl maleate) or butyltin trioctoate.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US93939478A | 1978-09-05 | 1978-09-05 | |
| US939,394 | 1978-09-05 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1109590A true CA1109590A (en) | 1981-09-22 |
Family
ID=25473109
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA333,894A Expired CA1109590A (en) | 1978-09-05 | 1979-08-16 | Polysiloxane release coating compositions and method for preparing same |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1109590A (en) |
-
1979
- 1979-08-16 CA CA333,894A patent/CA1109590A/en not_active Expired
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CA1174394A (en) | Silicone release coatings and inhibitors | |
| US4256870A (en) | Solventless release compositions, methods and articles of manufacture | |
| US4504645A (en) | Latently-curable organosilicone release coating composition | |
| US4533575A (en) | Latently-curable organosilicone release coating composition | |
| US5580915A (en) | Silicone adhesive compositions with improved quick stick | |
| US4526953A (en) | Modified silicone release coating compositions | |
| KR100509133B1 (en) | Silicone pressure sensitive adhesive compositions | |
| EP0628617B1 (en) | Moisture-curable hot melt silicone pressure-sensitive adhesives | |
| US4267297A (en) | Room temperature curable silicone resins | |
| DE3032059A1 (en) | TEMPERABLE PREPARATIONS AND METHOD FOR THEIR USE | |
| EP0390083B1 (en) | Liquid silicone resin compositions | |
| JPH0138414B2 (en) | ||
| EP0649891B1 (en) | Silicone compositions for the formation of cured release coatings | |
| JPH0848963A (en) | Pressure-sensitive silicone adhesive composition | |
| US5534610A (en) | Solventless two component primer composition for improved adhesion of RTV silicone elastomers to substrates | |
| EP0044673A1 (en) | Primer compositions containing phenylsiloxane resin | |
| US5064916A (en) | Organopolysiloxane composition for the formation of a cured release film | |
| US4223121A (en) | Organopolysiloxane resins of increased hardness | |
| AU622830B2 (en) | Silicone release coatings containing rhodium | |
| JP2889733B2 (en) | Silicone anticorrosive paint with long bath life | |
| GB2054624A (en) | Masking of abrasion injury on glass articles | |
| US3225419A (en) | Roller for applying fountain solution in lithographic printing | |
| GB740573A (en) | Improvements in or relating to organopolysiloxane adhesive compositions and adhesive tapes | |
| JPS6118939B2 (en) | ||
| FR2474518A1 (en) | Room temp. curing silicone resin compsn. - giving flexible anti-adhesion coatings, can be stored under anhydrous conditions |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |