Classifications

• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L83/00—Compositions of macromolecular compounds obtained by reactions forming in the main chain of the macromolecule a linkage containing silicon with or without sulfur, nitrogen, oxygen or carbon only; Compositions of derivatives of such polymers
  • C08L83/04—Polysiloxanes
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G77/00—Macromolecular compounds obtained by reactions forming a linkage containing silicon with or without sulfur, nitrogen, oxygen or carbon in the main chain of the macromolecule
  • C08G77/04—Polysiloxanes
  • C08G77/12—Polysiloxanes containing silicon bound to hydrogen
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K5/00—Use of organic ingredients
  • C08K5/04—Oxygen-containing compounds
  • C08K5/05—Alcohols; Metal alcoholates
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K5/00—Use of organic ingredients
  • C08K5/04—Oxygen-containing compounds
  • C08K5/15—Heterocyclic compounds having oxygen in the ring
  • C08K5/151—Heterocyclic compounds having oxygen in the ring having one oxygen atom in the ring
  • C08K5/1535—Five-membered rings
  • C08K5/1539—Cyclic anhydrides
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
  • C09D183/00—Coating compositions based on macromolecular compounds obtained by reactions forming in the main chain of the macromolecule a linkage containing silicon, with or without sulfur, nitrogen, oxygen, or carbon only; Coating compositions based on derivatives of such polymers
  • C09D183/04—Polysiloxanes
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G77/00—Macromolecular compounds obtained by reactions forming a linkage containing silicon with or without sulfur, nitrogen, oxygen or carbon in the main chain of the macromolecule
  • C08G77/04—Polysiloxanes
  • C08G77/14—Polysiloxanes containing silicon bound to oxygen-containing groups
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G77/00—Macromolecular compounds obtained by reactions forming a linkage containing silicon with or without sulfur, nitrogen, oxygen or carbon in the main chain of the macromolecule
  • C08G77/04—Polysiloxanes
  • C08G77/14—Polysiloxanes containing silicon bound to oxygen-containing groups
  • C08G77/18—Polysiloxanes containing silicon bound to oxygen-containing groups to alkoxy or aryloxy groups

Definitions

• the present invention relates to an improved adhesion promoting additive for use in silicone release coating compositions, and in particular, to an adhesion promoting additive having improved storage stability.
• Thermally curable silicone compositions are applied to substrates to facilitate in the release of adhesive materials thereon.
• Laminate constructions comprising a release coated polymeric film with a pressure sensitive adhesive and a sheet material that can be a label or decorative lamina are used by stripping off the release liner and affixing the lamina or label onto a surface.
• the thermally curable release compositions generally comprise (a) an alkenyl substituted polysiloxane (b) a hydride functional crosslinking silicone, such as a methyl hydrogen siloxane polymer, copolymer or oligomer, (c) a hydrosilylation catalyst, such as a platinum or rhodium based catalyst, and (d) a hydrosilylation inhibitor.
• a hydride functional crosslinking silicone such as a methyl hydrogen siloxane polymer, copolymer or oligomer
• a hydrosilylation catalyst such as a platinum or rhodium based catalyst
• a hydrosilylation inhibitor such as a platinum or rhodium based catalyst
• Adhesion promoting additives may be added to the release composition to improve the adhesion of the release coating to polymeric films, and in particular, to polyester films.
• Adhesion promoters for silicone release compositions often comprise polysiloxanes. It has been found that polysiloxane adhesion promoters can be unstable, particularly when stored over relatively long periods of time or when exposed to the atmosphere over relatively shorter periods of time. The viscosity of the adhesion promoting additive can increase to levels such that the additive becomes unusable. In addition, the evolution of hydrogen gas within the sealed container may become a safety issue. Summary
• the present invention provides for a release coating additive for a release coating that provides adhesion to polymeric films and that has improved storage stability.
• the adhesion promoting additive comprises (a) a polysiloxane having the formula (R a Si0( 4-a )/2)n where n is an integer greater than 3, a is from 1 to 3, R is an epoxide containing radical having from one to forty carbon atoms, monovalent hydrocarbon or hydrocarbonoxy radicals, hydride atoms, and with at least one epoxide and hydride being present on the molecule; and (b) an inhibitor.
• the present invention further provides a release liner comprising a polyester substrate and a silicone release coating on the polyester substrate.
• the silicone release liner comprises an adhesion promoting additive comprising (a) a polysiloxane having the formula (R a Si0( 4-a )/2)n where n is an integer greater than 3, a is from 1 to 3, R is an epoxide containing radical having from one to forty carbon atoms, monovalent hydrocarbon or hydrocarbonoxy radicals, hydride atoms, and with at least one epoxide and hydride being present on the molecule; and (b) an inhibitor.
• a polysiloxane having the formula (R a Si0( 4-a )/2)n where n is an integer greater than 3, a is from 1 to 3, R is an epoxide containing radical having from one to forty carbon atoms, monovalent hydrocarbon or hydrocarbonoxy radicals, hydride atoms, and with at least one epoxide and hydride being present on the molecule; and (b) an inhibitor.
• a method for making an adhesion promoting additive for release coatings having improved storage stability comprises (a) providing a polysiloxane having the formula (R a SiO( 4-a )/ 2 )n where n is an integer greater than 3, a is from 1 to 3, R is an epoxide containing radical having from one to forty carbon atoms, monovalent hydrocarbon or hydrocarbonoxy radicals, hydride atoms, and with at least one epoxide and hydride being present on the molecule; and (b) adding an inhibitor to the polysiloxane.
• the adhesion promoting additive of the present invention comprises a) a polysiloxane having the formula (R a Si0(4 -a )/ 2 )n where n is an integer greater than 3, a is from 1 to 3, R is an epoxide containing radical having from one to forty carbon atoms, monovalent hydrocarbon or hydrocarbonoxy radicals, hydride atoms, and with at least one epoxide and hydride being present on the molecule; and (b) an inhibitor.
• the adhesion promoting additive contains an epoxy functional silane selected from at least one of epoxycyclohexylethyl trimethoxysilane; ⁇ -glycidoxypropyl trimethoxysilane; ⁇ -glycidoxypropyl triethoxysilane; ⁇ -glycidoxypropyl methyldimethoxysilane; and y- glycidoxypropyl methyldiethoxysilane.
• an epoxy functional silane selected from at least one of epoxycyclohexylethyl trimethoxysilane; ⁇ -glycidoxypropyl trimethoxysilane; ⁇ -glycidoxypropyl triethoxysilane; ⁇ -glycidoxypropyl methyldimethoxysilane; and y- glycidoxypropyl methyldiethoxysilane.
• Inhibitors are well known in the organosilicon art.
• examples of various classes of such metal catalyst inhibitors include unsaturated organic compounds such as ethylenically or aromatically unsaturated amides; acetylenic compounds; ethylenically unsaturated isocyanates; olefinic siloxanes; unsaturated hydrocarbon diesters; and conjugated ene-ynes; other organic compounds such as hydroperoxides; ketones; sulfoxides; amines; phosphines; phosphites; nitrites; diaziridines; half esters and half amides; and various salts. It is believed that the compositions of this invention can comprise an inhibitor from any of these classes of inhibitors.
• Unsaturated amide inhibitors include those having the structural formula
• R 2 is CH 2 R 1 , or allyl;
• Y is aryl or
• x is 0 or 1 ; with the proviso tha at least one of R 1 and R 2 is ethylenically or aromatically unsaturated.
• amide inhibitors are described in US Patent 4,337,332.
• Useful acetylenic inhibitors include mono and di-alkynyl substituted derivatives of maleic acid having the formula:
• Additional acetylenic compounds are those described in US Patent 4,347,346, and include dialkylacetylenedicarboxylates that result from the diesterification reaction of 2-butynoic dicarboxylic acid with two equivalents of alcohols such as methanol, ethanol, butanol, benzylic alcohol, allyl alcohol or mixtures of such alcohols.
• Useful diesters prepared in this fashion include dimethylacetylenedicarboxylate, diethylenedicarboxylate, dibuty-acetylene- dicarboxylate, methylbutylacetylenedicarboxylate, methylethylacetylene- dicarboxylate, etc.
• Acetylenic compounds useful as inhibitors include those compounds described in US Patent 3,445,420, e.g.: ⁇ C3C ( CHi3n
• Ethylenically unsaturated isocyanate inhibitors include those having the structural formula: wherein R" is the same or different and is selected from the group consisting of hydrogen, lower alkyl, aryl, aralkyl, polynuclear aryl, heteroaryl, monofunctional lower-alkenyl and substituted derivatives thereof, with the proviso that at least one R" is monofunctional lower-alkenyl.
• R" is the same or different and is selected from the group consisting of hydrogen, lower alkyl, aryl, aralkyl, polynuclear aryl, heteroaryl, monofunctional lower-alkenyl and substituted derivatives thereof, with the proviso that at least one R" is monofunctional lower-alkenyl.
• R" is the same or different and is selected from the group consisting of hydrogen, lower alkyl, aryl, aralkyl, polynuclear aryl, heteroaryl, monofunctional lower-alkenyl and substituted derivatives thereof, with
• Olefinic siloxane inhibitors include polyorganosiloxanes consisting essentially of from 3 to 10 siloxane units in which (a) at least one siloxane unit is selected from the group consisting of RHSiO and R 2 HSiO 0 S and (b) at least one siloxane unit is selected fro the group consisting of
• siloxane units in (a) and (b) are equal to at least three siloxane units, and (c) any remaining siloxane units being selected from the group consisting of R3S1O 0 . 5 , SiO 2 and RSiOi 5 where each siloxane unit of (c) does not exceed three siloxane units, where R is a monovalent radical selected from the group consisting of hydrocarbon radicals and perfluoroalkylethylene radical, both having no more than six carbon atoms and R' is a monovalent hydrocarbon radical having a secondary or tertiary hydroxy substitution and having no more than ten carbon atoms.
• Such olefinic siloxane inhibitors are described in US Patent 3,989,667.
• Useful unsaturated hydrocarbon diester inhibitors include, for example, diallyl maleate.
• Other diallylic carboxylic esters include diallyphthalate and diallylsuccinate.
• saturated dialkyl esters of maleic acid such as diethyl and dimethyl maleate and mixed esters such as butylallyl maleate or methyl ethyl maleate are useful inhibitors.
• Silylmaleates such as bis- ⁇ -propyltris(methyoxy) silylmaleate, may also be used.
• Useful conjugated ene-yne inhibitors include those having the structural formula
• R 4 , R 5 and R 6 each denote, independently, a hydrogen atom, a monovalent hydrocarbon group or a divalent hydrocarbon group with the requirement that the total number of carbon atoms in these groups range from 2 to 6.
• Such inhibitors are described in US Patent 4,465,818.
• Examples of the monovalent hydrocarbon groups R 4 , R 5 and R 6 include groups such as methyl, ethyl and propyl groups; however, aryl groups such as the phenyl group may also be used.
• Examples of unsaturated hydrocarbons having monovalent hydrocarbon groups include 3-methyl-3-pentene-1-yne; 3-methyl- 3-hexene-1-yne; 3,5-dimethyl-3-hexene-1-yne; and 3-phenyl-3-butene-1-yne.
• Examples of divalent hydrocarbon groups R 4 , R 5 and R 6 include -CH 2 -, - CH 2 CH 2 -, -CH 2 CH 2 CH 2 -, -CH 2 CH(CH 3 )CH 2 -, -CH 2 C(CHg) 2 CH 2 -, and - CH 2 CH(CH 3 )CH 2 CH 2 -.
• Examples that containing divalent hydrocarbon groups which are bonded together by their second valence include
• Useful hydroperoxy inhibitors include those described in US Patent
• the hydroperoxy containing compound can have any desired structure as long as it contains a hydroperoxy radical in the molecular structure because it is such hydroperoxy radical that accomplishes the inhibiting activity.
• Other hydroperoxy inhibitor compounds that may be utilized in the instant invention are, for instance, methylethylketone peroxides, cumene hydroperoxide, 1 ,1 ,3,3-tetramethylbutylhydroperoxide and 2,5- dimethyl-2,5-dihydroperoxy hexane.
• methylethylketone peroxide cumene hydroperoxide, t-butyl hydroperoxide, 1-hydroxycyclohexyl hydroperoxide, 1 ,1 ,3,3-tetramethylbutyl hydroperoxide, 2,5-dimethyl-2,5-dihydroperoxy hexane, decalin hydroperoxide, 1 ,1 ,2,2-tetramethylpropyl hydroperoxide, p-methane hydroperoxide and pinane hydroperoxide.
• Ketone inhibitors include those having the general formula
• n is an integer ranging from 0 to 10, preferably ranging from 1 to 5
• R is a linear or branched chain alkyl radical having from 1 to 10 carbon atoms, an alkenyl radical having from 2 to 4 carbon atoms, a phenyl radical, a cycloalkyl radical having from 4 to 8 carbon atoms, an organosilyl radical selected from among the trialkylsilyl and trialkoxysilyl radicals in which the alkyl moiety has from 1 to 4 carbon atoms or a halogen atom selected from among chlorine, bromine and iodine, and R' is a hydrogen atom, an alkyl radical having from 1 to 4 carbon atoms, an ⁇ -hydroxyalkyl radical having from 1 to 4 carbon atoms, an alkylcarbonyl radical in which the alkyl moiety contains from 1 to 6 carbon atoms, a benzoyl radical, a benzoylalkyl radical in which the alkyl mol mo
• inhibitors are described in US Patent 4,595,739 and include 1-octyne-3-one; 8-chloro-1-octyn-3-one; 2-hydroxy-3-hexyn-5-one; 8-bromo-1 -ocryn-3-one; 4,4-dimethyl-1 -octyn-3- one; 7-chloro-1-heptyn-3-one; 1-chloro-7-dodecyn-6-one; 1-acetyl-1-n-octyne; 1-phenyl-1-butyn-3-one; 3-hexyn-3-one; 1-pentyn-3-one; 4-methyl-1-pentyn-3- one; 4,4-dimethyl-1-pentyn-3-one; 1-cyclohexyl-1-prppyn-3-one; 1-hexen-5- yn-4-one; benzoylacetylene; 0-chlorobenzoyl-acetylene; p-methoxybenz
• R 1 and R 2 represent a radical that contains up to 6 C atoms and wherein Ri and R 2 can together form a ring system.
• examples include dimethyl diaziridine, methylethyl diaziridine, diethyl diaziridine, methylisopropyl diaziridine, methylpropyl diaziridine, dipropyl diaziridine, pentamethylene diaziridine and hexamethylene diaziridine.
• Half ester and half amide inhibitors are described in US Patent 4,533,575 and include those having the structural formula
• R 3 is a saturated or unsaturated organic group having 1 to 12 carbon atoms which can be unsubstituted or substituted by 1 to 23 halogen atoms, and has up to 25 hydrogen atoms, and 0 to 5 non-peroxidic catenary oxygen atoms, and preferably R 3 is selected from organic groups consisting of (1 ) acyclic straight- chain saturated and unsaturated aliphatic groups having 1 to 12 carbon atoms, (2) saturated and unsaturated alicyclic groups having 3 to 12 carbon atoms, (3) aryl groups having 6 to 12 carbon atoms, (4) alkaryl and aralkyl groups having 7 to 12 carbon atoms, (5) alkenylaryl and aralkenylene groups having 8 to 12 carbon atoms, and (6) alkoxyalkyl and poly(alkoxy)alkyl
• R 4 is the same as defined for R 3 , and R 3 and R 4 together can be alkylene, which with the N, can form a saturated 5- or 6-atom membered azacyclic ring, and preferably X is -O-.
• Monoesters or monoamides may be prepared by reaction of one mole of maleic anhydride or acetylenedicarboxylic acid with one mole of an amine, R 3 -NH-R 4 , in which in which R 3 and R 4 are as defined for formula 11.
• monohydrogen esters are methyl hydrogen, maleate, ethyl hydrogen maleate, 2-fluoroethyl hydrogen maleate, 2,2,2-trifluoroethyl hydrogen maleate, 1 ,1-dihydroperfluoropropyl hydrogen maleate, 1 ,1- dihydroperfluorooctyl hydrogen maleate, 1 ,1-dihydroperfluorododecyl hydrogen maleate, butyl hydrogen maleate, hexyl hydrogen maleate, dodecyl hydrogen maleate, isopropyl hydrogen maleate, 2-ethylhexyl hydrogen maleate, isooctyl hydrogen maleate, cyclobutyl hydrogen maleate, cyclopentyl hydrogen maleate, cyclohexyl hydrogen maleate, 3,3,5-trimethylcyclohexyl hydrogen maleate, 1-isopropyl-4-methylcyclohexyl hydrogen maleate, ethenyl hydrogen maleate, isopropenyl hydrogen
• Examples of monoamides of unsaturated aliphatic 1 ,4-dicarboxylic acids that are useful as inhibitors are N-methylmaleamic acid, N 1 N- dimethylmaleamic acid, N-ethylmaleamic acid, N-2,2,2-trifluoroethylmaleamic acid, N,N-diethyl maleamic acid, N-propylmaleamic acid, N-butylmaleamic acid, N,N-bis(2-ethylhexyl)maleamic acid, N-cyclopentylmaleamic acid, N- pentamethylenemaleamic acid, N-allylmaleamic acid, N-phenylmaleamic acid, N-methylcarbamoylpropiolic acid, N,N-dimethylcarbamoylpropiolic acid, N- ethylcarbamoylpropiolic acid, N-(2-ethylhexyl)carbamoylpropiolic acid, N
• Useful salt inhibitors are disclosed in US Patent 3,461 ,185 and include tetramethyl guanidine carboxylates such as tetramethylguanidine acetate, tetramethyl guanidine propionate, tetramethyl guanidine butyrate, tetramethyl guanidine valerate, tetramethyl guanidine caproate, tetramethyl guanidine enanthate, tetramethyl guanidine caprylate, tetramethyl guanidine pelargonate, tetramethyl guanidine caprate, tetramethyl guanidine hendecanoate, tetramethyl guanidine laurate, tetramethyl guanidine tridecanoate, tetramethyl guanidine myristate, tetramethyl guanidine pentadecanoate, tetramethyl guanidine palmitate, tetramethyl guanidine thfluoroa
• the inhibitor may be added to the polysiloxane adhesion promoting additive in an amount of from about 0.1 % to about 3% by weight, based on the weight of the polysiloxane. In one embodiment, the inhibitor is added in an amount of from about 0.5% to about 1 % by weight.
• AGE allyl glycidyl ether
• 20 ppm rhodium using an
• An inhibitor, 3,5-dimethyl-1-hexyn- 3-ol, is added to the polysiloxane in amount of 1 % by weight.
• An inhibitor, 3,5-dimethyl-1-hexyn-3-ol, is added to the polysiloxane in amount of 1 % by weight.
• AnchorSil 2000 an adhesion promoting additive commercially available from General Electric, in the amounts shown (weight %, based on the weight of the AnchorSil 2000) in Table 1 below.
• the stability of the adhesion promoting additive is determined by the time it takes for the additive to gel.
• the failure mode is characterized by a viscosity increase, accompanied by a random bubble formation at the fluid surface, believed to be H 2 evolution. Brookfield viscosity is recorded for the initial measurement.
• the stabilized adhesion promoting additive may be added to a curable silicone release composition.
• the silicone release composition may comprise an alkenyl substituted polysiloxane base polymer, a hydride functional crosslinking siloxane polymer, an addition cure hydrosilylation catalyst and a cure inhibiting compound.
• the curable silicone release composition containing the stabilized adhesion promoting additive may be coated on a substrate to form a release liner.
• the substrate may be paper or a polymeric film such as polyester, polyethylene and polypropylene.

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  • 2007-05-31 WO PCT/US2007/070056 patent/WO2007146603A2/en active Application Filing
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  • 2007-05-31 KR KR1020097000081A patent/KR20090031892A/ko not_active Application Discontinuation
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