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US 5,202,190 AGranted
Method of making vinyl-silicone copolymers using mercapto functional silicone chain-transfer agents and release coatings made therewith
AssigneeMinnesota Mining and Manufacturing Company
InventorsSteven S. Kantner, Ramesh C. Kumar, Gilbert L. Eian
Life of this patent
Estimating the term…
Abstract
A method of preparing vinyl-silicone copolymers which involves the use of a mercapto-functional silicone compound as a macromolecular chain transfer agent. Release coatings and low adhesion backsizes comprising the vinyl-silicone copolymers.
Claims8
A stack of superimposed sheets of coated sheet material wherein the coated sheet material comprises:
- (a) a flexible sheet;
- and
- (b) a release coating covering at least a portion of one major surface of one side of said flexible sheet wherein said release coating comprises a vinyl-silicone copolymer formed according to the method of:
- (a) mixing (1) free radically polymerizable monomer mixed, if needed, with sufficient solvent to produce a charge which possesses a net dielectric constant greater than about 2.5, (2) a mercapto functional silicone compound represented by the formula ##STR20## wherein R.sub.1 are monovalent moieties which can independently be the same or different and are selected from the group consisting of alkyl, aryl, alkaryl, alkoxy, alkylamino, hydroxyl, hydrogen, and fluoroalkyl;
- R.sub.2 can independently be the same or different and are divalent linking groups;
- R.sub.3 are monovalent moieties which can independently be the same or different and are selected from the group consisting of alkyl, aryl, alkaryl, alkoxy, alkylamino, hydroxyl, hydrogen, and fluoroalkyl;
- R.sub.4 can independently be the same or different and are divalent lining groups;
- R.sub.5 are monovalent moieties which can independently be the same or different and are selected from the group consisting of alkyl, aryl, alkaryl, alkoxy, alkylamino, hydroxyl, hydrogen, fluoroalkyl and -ZSH, wherein Z is a divalent linking group;
- R.sub.6 are monovalent moieties which can independently be the same or different and are selected from the group consisting of alkyl, aryl, alkaryl, alkoxy, alkylamino, ahydroxyl, fluoroalkyl, hydrogen, and -ZSH wherein Z is a divalent linking group;
- wherein
- x is an integer of 0 to 3;
- y is an integer of 10 or greater;
- q is an integer of 0 to 3;
- R.sub.5 comprises 0 to y -ZSH moieties;
- R.sub.6 comprises 0 to y -ZSH moieties;
- and
- wherein at least one of the following is true:
- q is an integer of at least 1:
- x is an integer of at least 1;
- R.sub.5 comprises at least one -ZSH moiety;
- R.sub.6 comprises at least one -ZSH moiety;
- and
- (3) an initiator capable of forming free radicals upon being subjected to a means of initiation wherein said free radicals are capable of abstracting the -ZSH hydrogen atoms of the mercapto functional silicone compound to form mercapto functional silicone free radicals,
- wherein said mercapto functional silicone free radicals are capable of initiating free radical polymerization of said free radically polymerizable monomer to form a graft copolymer or block copolymer represented by the formula ##STR21## wherein G.sub.5 are monovalent moieties which can independently be the same of different selected from the group consisting of alkyl, aryl, alkaryl, alkoxy, alkylamino, fluoroalkyl, hydrogen, and -ZSA;
- A is a vinyl polymeric segment or block consisting essentially of polymerized free radically polymerized monomer;
- G.sub.6 are monovalent moieties which can independently be the same or different selected from the group consisting of alkyl, aryl, alkaryl, alkoxy, alkylamino, fluoroalkyl, hydrogen, and -ZSA;
- G.sub.2 comprises A;
- G.sub.4 comprises A;
- and
- R.sub.1, R.sub.2, R.sub.3, R.sub.4, x, q, y, and Z are as previously defined;
- (b) initiating free-radical polymerization;
- and
- (c) sustaining said free-radical polymerization until said vinyl-silicone copolymer is produced, wherein A comprises at least about 40 weight percent of copolymer and possesses a Tg or Tm above about -20.degree. C., and wherein a silicone segment of the copolymer has a number average molecular weight above about 1000 and wherein the silicone segment is present at a weight percent great enough to provide said copolymer with a surface release value not greater than about 50 Newtons/dm, wherein the release agent is on one side of the sheet and a pressure sensitive adhesive is on the other side, the pressure-sensitive adhesive on each sheet being in contact with the release agent on an immediately adjacent sheet, and wherein the pressure sensitive adhesive is a normally tacky pressure-sensitive adhesive.
30 more elements
A coated sheet material wherein the coated sheet material comprises:
- (a) a flexible sheet;
- and
- (b) a release coating covering at least a portion of one major surface of one side of said flexible sheet wherein said release coating comprises a vinyl-silicone copolymer formed according to the method of:
- (a) mixing (1) free radically polymerizable monomer mixed, if needed, with sufficient solvent to produce a charge which possesses a net dielectric constant greater than about 2.5 (2) a mercapto functional silicone compound represented by the formula ##STR22## wherein R.sub.1 are monovalent moieties which can independently be the same or different and are selected from the group consisting of alkyl, aryl, alkaryl, alkoxy, alkylamino, hydroxyl, hydrogen, and fluoroalkyl;
- R.sub.2 can independently be the same or different and are divalent linking groups;
- R.sub.3 are monovalent moieties which can independently be the same or different and are selected from the group consisting of alkyl, aryl, alkaryl, alkoxy, alkylamino, hydroxyl, hydrogen, and fluoroalkyl;
- R.sub.4 can independently be the same or different and are divalent linking groups;
- R.sub.5 are monovalent moieties which can independently be the same or different and are selected from the group consisting of alkyl, aryl, alkaryl, alkoxy, alkylamino, hydroxyl, hydrogen, fluoroalkyl and -ZSH, wherein Z is a divalent linking group;
- R.sub.6 are monovalent moieties which can independently be the same or different and are selected from the group consisting of alkyl, aryl, alkaryl, alkoxy, alkylamino, hydroxyl, fluoroalkyl, hydrogen, and -ZSH wherein Z is a divalent linking group;
- wherein
- x is an integer of 0 to 3;
- y is an integer of 10 or greater;
- q is an integer of 0 to 3;
- R.sub.5 comprises 0 to y -ZSH moieties;
- R.sub.6 comprises 0 to y -ZSH moieties;
- and
- wherein at least one of the following is true:
- q is an integer of at least 1;
- x is an integer of at least 1;
- R.sub.5 comprises at least one -ZSH moiety;
- R.sub.6 comprises at least one -ZSH moiety;
- and
- (3) an initiator capable of forming free radicals upon being subjected to a means of initiation wherein said free radicals are capable of abstracting the -ZSH hydrogen atoms of the mercapto functional silicone compound to form mercapto functional silicone free radicals,
- wherein said mercapto functional silicone free radicals are capable of initiating free radical polymerization of said free radically polymerizable monomer to form a graft copolymer or block copolymer represented by the formula ##STR23## wherein G.sub.5 are monovalent moieties which can independently be the same or different selected from the group consisting of alkyl, aryl, alkaryl, alkoxy, alkylamino, fluoroalkyl, hydrogen, and -ZSA;
- A is a vinyl polymeric segment or block consisting essentially of polymerized free radically polymerized monomer;
- G.sub.6 are monovalent moieties which can independently be the same or different selected from the group consisting of alkyl, aryl, alkaryl, alkoxy, alkylamino, fluoroalkyl, hydrogen, and -ZSA;
- G.sub.2 comprises A;
- G.sub.4 comprises A;
- and
- R.sub.1, R.sub.2, R.sub.3, R.sub.4, x, q, y, and Z are as previously defined;
- (b) initiating free-radical polymerization;
- and
- (c) sustaining said free-radical polymerization until said vinyl-silicone copolymer is produced, wherein A comprises at least about 40 weight percent of the copolymer and possesses a Tg or Tm above about -20.degree. C., and wherein a silicone segment of the copolymer has a number average molecular weight above about 1000 and wherein the silicone segment is present at a weight percent great enough to provide said copolymer with a surface release value not greater than about 50 Newtons/dm, wherein the release agent is on one side of the sheet and a pressure sensitive adhesive is on the other side, wound convolutely on itself about a core to form a roll.
30 more elements
A coated sheet material wherein the coated sheet material comprises:
- (a) a flexible sheet;
- and
- (b) a release coating covering at least a portion of one major surface of one side of said flexible sheet wherein said release coating comprises a vinyl-silicone copolymer formed according to the method of:
- (a) mixing (1) free radically polymerizable monomer mixed, if needed, with sufficient solvent to produce a charge which possesses a net dielectric constant greater than about 2.5, (2) a mercapto functional silicone compound represented by the formula ##STR24## wherein R.sub.1 are monovalent moieties which can independently be the same or different and are selected from the group consisting of alky, aryl, alkaryl, alkoxy, alkylamino, hydroxyl, hydrogen, and fluoroalkyl;
- R.sub.2 can independently be the same or different and are divalent linking groups;
- R.sub.3 are monovalent moieties which independently be the same or different and are selected from the group consisting of alkyl, aryl, alkaryl, alkoxy, alkylamino, hydroxyl, hydrogen, and fluoroalkyl;
- R.sub.4 can independently be the same or different and are divalent linking groups;
- R.sub.5 are monovalent moieties which can independently be the same or different and are selected from the group consisting of alkyl, aryl, alkaryl, alkoxy, alkylamino, ahydroxyl, hydrogen, fluoroalkyl and -ZSH, wherein Z is a divalent linking group;
- R.sub.6 are monovalent moieties which can independently be the same or different and are selected from the group consisting of alkyl, aryl, alkaryl, alkoxy, alkylamino, hydroxyl, fluoroalkyl, hydrogen, and -ZSH wherein Z is a divalent linking group;
- wherein
- x is an integer of 0 and 3;
- y is an integer of 10 or greater;
- q is an integer of 0 and 3;
- R.sub.5 comprises 0 to y -ZSH moieties;
- R.sub.6 comprises 0 to y -ZSH moieties;
- and
- wherein at least one of the following is true;
- q is an integer of at least 1;
- x is an integer of at least 1;
- R.sub.5 comprises at least one -ZSH moiety;
- R.sub.6 comprises at least one -ZSH moiety;
- and
- (3) an initiator capable of forming free radicals upon being subjected to a means of initiation wherein said free radicals are capable of abstracting the -ZSH hydrogen atoms of the mercapto functional silicone compound to form mercapto functional silicone free radicals,
- wherein said mercapto functional silicone free radicals are capable of initiating free radical polymerization of said free radically polymerizable monomer to form a graft copolymer or block copolymer represented by the formula ##STR25## wherein G.sub.5 are monovalent moieties which can independently be the same or different selected from the group consisting of alkyl, aryl, alkaryl, alkoxy, alkylamino, fluoroalkyl, hydrogen, and -ZSA;
- A is a vinyl polymeric segment or block consisting essentially of polymerized free radically polymerized monomer;
- G.sub.6 are monovalent moieties which can independently be the same or different selected from the group consisting of alkyl, aryl, alkaryl, alkoxy, alkylamino, fluoroalkyl, hydrogen, and -ZSA;
- G.sub.2 comprises A;
- G.sub.4 comprises A;
- and
- R.sub.1, R.sub.2, R.sub.3, R.sub.4, x, q, y, and Z are as previously defined;
- (b) initiating free-radical polymerization;
- and
- (c) sustaining said free-radical polymerization until said vinyl-silicone copolymer is produced, wherein A comprises at least about 40 weight percent of the copolymer and possesses a Tg or Tm above about -20.degree. C., and wherein a silicone segment of the copolymer has a number average molecular weight above about 1000 and wherein the silicone segment is present at a weight percent great enough to provide said copolymer with a surface release value not greater than about 50 Newtons/dm, wherein the release agent covers a first portion of one side and a normally tacky and pressure-sensitive adhesive covers a second portion of the same side.
30 more elements
A coated sheet material wherein the coated sheet material comprises:
- (a) a flexible sheet;
- and
- (b) a release coating covering at least a portion of one major surface of one side of said flexible sheet wherein said release coating comprises a vinyl-silicone copolymer formed according to the method of:
- (a) mixing (1) free radically polymerizable monomer mixed, if needed, with sufficient solvent to produce a charge which possesses a net dielectric constant greater than about 2.5, (2) a mercapto functional silicone compound represented by the formula ##STR26## wherein R.sub.1 are monovalent moieties which can independently be the same or different and are selected from the group consisting of alkyl, aryl, alkaryl, alkoxy, alkylamino, hydroxyl, hydrogen, and fluoroalkyl;
- R.sub.2 can independently be the same or different and are divalent linking groups;
- R.sub.3 are monovalent moieties which can independently be the same or different and are selected from the group consisting of alkyl, aryl, alkaryl, alkoxy, alkylamino, hydroxyl, hydrogen, and fluoroalkyl;
- R.sub.4 can independently be the same or different and are divalent linking groups;
- R.sub.5 are monovalent moieties which can independently be the same or different and are selected from the group consisting of alkyl, aryl, alkaryl, alkoxy, alkylamino, hydroxyl, hydrogen, fluoroalkyl and -ZSH, wherein Z is a divalent linking group;
- R.sub.6 are monovalent moieties which can independently be the same or different and are selected from the group consisting of alkyl, aryl, alkaryl, alkoxy, alkylamino, hydroxyl, fluoroalkyl, hydrogen, and -ZSH wherein Z is a divalent linking group;
- wherein
- x is an integer of 0 to 3;
- y is an integer of 10 or greater;
- q is an integer of 0 to 3;
- R.sub.5 comprises 0 to y -ZSH moieties;
- R.sub.6 comprises 0 to y -ZSH moieties;
- and
- wherein at least one of the following is true:
- q is an integer of at least 1;
- x is an integer of at least 1;
- R.sub.5 comprises at least one -ZSH moiety;
- R.sub.6 comprises at least one -ZSH moiety;
- and
- (3)an initiator capable of forming free radicals upon being subjected to a means of initiation wherein said free radicals are capable of abstracting the -ZSH hydrogen atoms of the mercapto functional silicone compound to form mercapto functional silicone free radicals,
- wherein said mercapto functional silicone free radicals are capable of initiating free radical polymerization of said free radically polymerizable monomer to form a graft copolymer or block copolymer represented by the formula ##STR27## wherein G.sub.5 are monovalent moieties which can independently be the same or different selected from the group consisting of alkyl, aryl, alkaryl, alkoxy, alkylamino, fluoroalkyl, hydrogen, and -ZSA;
- A is a vinyl polymeric segment or block consisting essentially of polymerized free radically polymerized monomer;
- G.sub.6 are monovalent moieties which can independently be the same or different selected from the group consisting of alkyl, aryl, alkaryl, alkoxy, alkylamino, fluoroalkyl, hydrogen, and -ZSA;
- G.sub.2 comprises A;
- G.sub.4 comprises A;
- and
- R.sub.1, R.sub.2, R.sub.3, R.sub.4, x, q, y, and Z are a previously defined;
- (b) initiating free-radical polymerization;
- and
- (c) sustaining said free-radical polymerization until said vinyl-silicone copolymer is produced, wherein A comprises at least about 40 weight percent of the copolymer and possesses a Tg or Tm above about -20.degree. C., and wherein a silicone segment of the copolymer has a number average molecular weight above about 1000 and wherein the silicone segment is present at a weight percent great enough to provide said copolymer with a surface release value not greater than about 50 Newtons/dm, wherein the release agent is on one side of the sheet and a pressure sensitive adhesive is on the other side, wherein the adhesive is present in a band adjacent one edge of the sheet.
30 more elements
Dependencies are inferred from the claim text.