Classifications

• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
  • C09J133/00—Adhesives based on homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by only one carboxyl radical, or of salts, anhydrides, esters, amides, imides, or nitriles thereof; Adhesives based on derivatives of such polymers
  • C09J133/04—Homopolymers or copolymers of esters
  • C09J133/06—Homopolymers or copolymers of esters of esters containing only carbon, hydrogen and oxygen, the oxygen atom being present only as part of the carboxyl radical
  • C09J133/062—Copolymers with monomers not covered by C09J133/06
  • C09J133/066—Copolymers with monomers not covered by C09J133/06 containing -OH groups
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
  • C09J175/00—Adhesives based on polyureas or polyurethanes; Adhesives based on derivatives of such polymers
  • C09J175/04—Polyurethanes
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
  • C09J133/00—Adhesives based on homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by only one carboxyl radical, or of salts, anhydrides, esters, amides, imides, or nitriles thereof; Adhesives based on derivatives of such polymers
  • C09J133/04—Homopolymers or copolymers of esters
  • C09J133/06—Homopolymers or copolymers of esters of esters containing only carbon, hydrogen and oxygen, the oxygen atom being present only as part of the carboxyl radical
  • C09J133/08—Homopolymers or copolymers of acrylic acid esters
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
  • C08F220/00—Copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and only one being terminated by only one carboxyl radical or a salt, anhydride ester, amide, imide or nitrile thereof
  • C08F220/02—Monocarboxylic acids having less than ten carbon atoms; Derivatives thereof
  • C08F220/10—Esters
  • C08F220/12—Esters of monohydric alcohols or phenols
  • C08F220/14—Methyl esters, e.g. methyl (meth)acrylate
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
  • C08F220/00—Copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and only one being terminated by only one carboxyl radical or a salt, anhydride ester, amide, imide or nitrile thereof
  • C08F220/02—Monocarboxylic acids having less than ten carbon atoms; Derivatives thereof
  • C08F220/10—Esters
  • C08F220/12—Esters of monohydric alcohols or phenols
  • C08F220/16—Esters of monohydric alcohols or phenols of phenols or of alcohols containing two or more carbon atoms
  • C08F220/18—Esters of monohydric alcohols or phenols of phenols or of alcohols containing two or more carbon atoms with acrylic or methacrylic acids
  • C08F220/1804—C4-(meth)acrylate, e.g. butyl (meth)acrylate, isobutyl (meth)acrylate or tert-butyl (meth)acrylate
• • 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
  • C08G18/00—Polymeric products of isocyanates or isothiocyanates
  • C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
  • C08G18/28—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the compounds used containing active hydrogen
  • C08G18/40—High-molecular-weight compounds
  • C08G18/62—Polymers of compounds having carbon-to-carbon double bonds
  • C08G18/6216—Polymers of alpha-beta ethylenically unsaturated carboxylic acids or of derivatives thereof
  • C08G18/622—Polymers of esters of alpha-beta ethylenically unsaturated carboxylic acids
  • C08G18/6225—Polymers of esters of acrylic or methacrylic acid
  • C08G18/6229—Polymers of hydroxy groups containing esters of acrylic or methacrylic acid with aliphatic polyalcohols
• • 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
  • C08G18/00—Polymeric products of isocyanates or isothiocyanates
  • C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
  • C08G18/70—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the isocyanates or isothiocyanates used
  • C08G18/81—Unsaturated isocyanates or isothiocyanates
  • C08G18/8108—Unsaturated isocyanates or isothiocyanates having only one isocyanate or isothiocyanate group
  • C08G18/8116—Unsaturated isocyanates or isothiocyanates having only one isocyanate or isothiocyanate group esters of acrylic or alkylacrylic acid having only one isocyanate or isothiocyanate group
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
  • C09J133/00—Adhesives based on homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by only one carboxyl radical, or of salts, anhydrides, esters, amides, imides, or nitriles thereof; Adhesives based on derivatives of such polymers
  • C09J133/02—Homopolymers or copolymers of acids; Metal or ammonium salts thereof
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
  • C09J7/00—Adhesives in the form of films or foils
  • C09J7/20—Adhesives in the form of films or foils characterised by their carriers
  • C09J7/22—Plastics; Metallised plastics
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
  • C09J7/00—Adhesives in the form of films or foils
  • C09J7/30—Adhesives in the form of films or foils characterised by the adhesive composition
  • C09J7/38—Pressure-sensitive adhesives [PSA]
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
  • C09J7/00—Adhesives in the form of films or foils
  • C09J7/30—Adhesives in the form of films or foils characterised by the adhesive composition
  • C09J7/38—Pressure-sensitive adhesives [PSA]
  • C09J7/381—Pressure-sensitive adhesives [PSA] based on macromolecular compounds obtained by reactions involving only carbon-to-carbon unsaturated bonds
  • C09J7/385—Acrylic polymers
• • 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
  • C08G2170/00—Compositions for adhesives
  • C08G2170/40—Compositions for pressure-sensitive adhesives
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
  • C09J2301/00—Additional features of adhesives in the form of films or foils
  • C09J2301/30—Additional features of adhesives in the form of films or foils characterized by the chemical, physicochemical or physical properties of the adhesive or the carrier
  • C09J2301/302—Additional features of adhesives in the form of films or foils characterized by the chemical, physicochemical or physical properties of the adhesive or the carrier the adhesive being pressure-sensitive, i.e. tacky at temperatures inferior to 30°C
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
  • C09J2301/00—Additional features of adhesives in the form of films or foils
  • C09J2301/30—Additional features of adhesives in the form of films or foils characterized by the chemical, physicochemical or physical properties of the adhesive or the carrier
  • C09J2301/312—Additional features of adhesives in the form of films or foils characterized by the chemical, physicochemical or physical properties of the adhesive or the carrier parameters being the characterizing feature
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
  • C09J2433/00—Presence of (meth)acrylic polymer

Definitions

• Acrylic pressure sensitive adhesives that are resistant to a wide range of solvents, including both polar and non-polar solvents.
• PSA's Pressure sensitive adhesives
• Solvent resistance is one desirable property of a PSA that enables its use and application in environments subject to exposure to solvents. If a PSA is unable to resist a certain solvent, the solvent can be absorbed into the polymer where it can adversely impact the physical characteristics of the PSA, such as peel adhesion strength or shear resistance, and thereby result in reduced bonding strength and potentially, in a worst case scenario, delamination.
• a PSA's resistance to solvents is not uniformly applicable to all solvents.
• a PSA may be resistant to non-polar solvents but susceptible to polar solvents. The chemical structure of the PSA, the polarity of the solvent, or the solubility of the polymer with a given solvent may all impact a PSA's ability to resists a specific type of solvent.
• This disclosure is directed at specific acrylic PSA compositions that are capable of resisting a broad array of solvents.
• Conventional PSA's currently available may be able to resist certain types or categories of solvents.
• the ability to withstand multiple categories of solvents with conventional PSA's generated from a significant amount of C4-C8 acrylate monomers (such as butyl acrylate and/or isooctyl acrylate) is presently unrecognized. It is desirable to offer a PSA that is cable of withstanding such diverse solvents such as water, a polar solvent, and oleic acid, a non-polar solvent.
• Certain embodiments of this disclosure are directed to acrylic PSA's primarily derived from C1-C4 acrylate monomers, and in particular methyl acrylate (a Ci acrylate).
• Acrylic PSA's made in accordance with this disclosure exhibit a strong resistance to a wide array of solvents, including those solvents in the polar and non-polar solvents categories.
• an acrylic pressure sensitive adhesive derived from the reaction product of (i) about 20 percent by weight to about 60 percent by weight of a methyl acrylate, (ii) about 40 percent by weight to about 80 percent by weight of a monomer comprising ethyl acrylate, propyl acrylate, butyl acrylate, or combinations thereof, (iii) about 0.2 percent by weight to about 5 percent by weight of a functional acrylate monomer, and (iv) a crosslinking agent, exhibits an unexpected and superior improvement in its resistance to both polar and non-polar solvents over conventional acrylic PSA's while maintaining desirable adhesive qualities.
• the resistance to certain solvents can be measured using a solvent swell test.
• the test measures the acrylic PSA's absorption of a selected solvent when immersed in that solvent for an extended period of time. The results are reported as a ratio of the acrylic PSA's gain in mass due to absorbed solvent over a baseline mass.
• the acrylic pressure sensitive adhesive of this disclosure exhibits a resistance to polar and non-polar solvents as demonstrated by a solvent swell ratio of 1.8 or less after immersion in a 1 : 1 water and isopropyl alcohol mixture in accordance with the Swelling Ratio Test and solvent swell ratio of 1.5 or less after immersion in oleic acid in accordance with the Swelling Ratio Test.
• the acrylic PSA has a peel adhesion strength of 0.7 N/mm or greater in accordance with the Peel Adhesion Test.
• the acrylic PSA's of this disclosure may be polymerized using conventional monomer polymerization practices.
• free radical solvent polymerization is one method well suited to create the acrylic PSA's.
• Acrylic PSA's polymerized primarily from C1-C4 acrylate monomers, as embodied through this disclosure, may be applied to a substrate to form various articles.
• Substrates may include conventional polymeric substrates or webs.
• a composition comprising an acrylic PSA is derived from the reaction product of multiple monomeric or organic components. The following components are reported as a percent by weight for the total polymerizable mixture.
• the first component is a monomer comprising about 20 percent by weight to about 60 percent by weight of a methyl acrylate.
• a second component includes about 40 percent by weight to about 80 percent by weight of a monomer selected from the group comprising ethyl acrylate, propyl acrylate, butyl acrylate, or combinations thereof.
• a third component comprises about 0.2 percent by weight to about 5 percent by weight of a functional acrylate monomer.
• the reaction product of the noted components is an adhesive copolymer generally referred to as an acrylic PSA.
• a crosslinking agent is included in the polymerized mixture.
• a pressure sensitive adhesive or PSA can be identified by a means known as the Dahlquist criterion.
• This criterion defines a PSA as an adhesive having a 1 second creep compliance of greater than lxl 0 "6 cm2 /dyne as described in Handbook of PSA Technology, Donatas Satas (Ed.), 2 nd Edition, p. 172, Van Nostrand Reinhold, New York, N.Y., 1989.
• PSA's may be defined as adhesives having a Young's modulus of less than lxl 0 6 dynes/cm 2 .
• PSA is aggressively and permanently tacky at room temperature and firmly adheres to a variety of dissimilar surfaces upon mere contact without the need of more than finger or hand pressure, and which may be removed from smooth surfaces without leaving a residue as described in Glossary of Terms Used in the Pressure Sensitive Tape Industry provided by the Pressure Sensitive Tape Council, 1996.
• a suitable PSA preferably has a room temperature storage modulus within the area defined by the following points as plotted on a graph of modulus versus frequency at 25 degrees centigrade : a range of moduli from approximately 2xl0 5 to 4xl0 5 dynes/cm 2 at a frequency of approximately 0.1 radians/sec (0.017 Hz), and a range of moduli from approximately 2xl0 6 to 8xl0 6 dynes/cm 2 at a frequency of approximately 100 radians/sec (17 Hz) (for example see Fig. 8-16 on p. 173 of Handbook of PSA Technology (Donatas Satas, Ed.), 2 nd Edition, Van Nostrand Rheinhold, N.Y., 1989). Any of these methods of identifying a PSA may be used to identify suitable PSA's produced in accordance with this disclosure.
• Methyl acrylate is one of the monomers components of the polymerizable mixture that enhances the ability of the resulting PSA to withstand solvents, particularly non-polar solvents.
• the methyl acrylate monomer is included in amount of about 20 percent by weight to about 60 percent. In other embodiments, it is included in an amount of about 30 percent by weight to about 50 percent by weight.
• One source of commercially available methyl acrylate is the Dow Chemical Company, Midland, MI.
• An additional monomer component of the polymerizable mixture are C2-C4 acrylate monomers.
• the additional acrylate monomers impart the necessary PSA characteristics into the polymer. This is partially attributed to the low Tg properties of the monomers, which in some embodiments are below - 120 °C.
• the C2-C4 acrylate monomers include ethyl acrylate, propyl acrylate, butyl acrylate, or combinations thereof.
• the noted acrylate monomers are included in the polymerizable composition at about 40 percent by weight to about 80 percent. In other embodiments, the C2-C4 acrylate monomers comprise about 50 percent by weight to about 70 percent by weight.
• acrylates may be incorporated into the polymeric chain during polymerization.
• a functional acrylate is an ethylenically unsaturated monomer having an additional functional moiety.
• Functional moieties may include hydroxyl, carboxylic acid, isocyanate, azilidine or epoxy functional groups.
• the functional monomer may include hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, hydroxybutyl (meth)acrylate, isocyanatoethyl (meth) acrylate, (meth)acrylic acid, glycidyl (meth) acrylate or combinations thereof.
• the functional monomer is typically about 0.2 percent by weight to about 5 percent by weight in the polymerizable composition.
• the monomers can be polymerized by conventional techniques including, but not limited to, solvent polymerization, emulsion polymerization, and bulk polymerization.
• the monomer mixture may comprise a polymerization initiator, of a type and in an amount effective to polymerize the comonomers.
• a crosslinking agent is generally included in the composition for subsequent crosslinking upon application of the polymer in its desired end state.
• a crosslinking agent can be thermally activated after the coating of the polymerized components onto a backing. Upon activation, the crosslinking agent interacts with the functional moieties from the functional acrylate to improve cohesive strength and enhance solvent resistance.
• the crosslinking agent generally comprises compounds containing hydroxyl, carboxylic acid, isocyanate, azilidine or epoxy functional groups.
• Non-limiting example of crosslinking agents include aromatic polyisocyanates, such as DESMODUR L75, from Bayer Materialscience, Pittsburgh, PA, benzoyl peroxides, such as Luperox 75, from Arkema, Cary, NC,
• the crosslinking agent is included in the acrylic polymer in an amount of about 0.1 to about 2.0 percent by weight.
• the acrylic PSAs may be self-tacky or, in alternative embodiments, may be tackified.
• Useful tackifiers for acrylic PSA's are rosin esters such as that available under the trade name FORAL 85 from Hercules, Inc., aromatic resins such as that available under the trade name PICCOTEX LC-55WK from Hercules, Inc., aliphatic resins such as that available under the trade name PICCOTAC 95 from Hercules, Inc., and terpene resins such as that available under the trade names PICCOLYTE A-l 15 and ZONAREZ B-100 from Arizona Chemical Co.
• rosin esters such as that available under the trade name FORAL 85 from Hercules, Inc.
• aromatic resins such as that available under the trade name PICCOTEX LC-55WK from Hercules, Inc.
• aliphatic resins such as that available under the trade name PICCOTAC 95 from Hercules, Inc.
• Acrylic PSA's produced in accordance with his disclosure can be employed to form tapes and transfer adhesive.
• Acrylic PSA articles may be prepared by coating the composition on a suitable support, such as a flexible backing.
• suitable support such as a flexible backing.
• suitable support such as a flexible backing.
• materials that can be included in the flexible backing include polyolefms, such as polyethylene, polypropylene, polystyrene, polyester, polyvinyl chloride, polyurethane, polyvinyl alcohol, poly(ethylene terephthalate), poly(butylene terephthalate), poly(caprolactam), poly(vinylidene fluoride), polylactides, cellulose acetate, and ethyl cellulose and the like.
• Other non-limiting examples of commercially available backing materials include kraft paper, spun-bond polyolefms, porous films obtained from polyolefms, and multi-layered constructions.
• Backings may also be prepared of fabric such as woven fabric formed of threads of synthetic or natural materials such as cotton, nylon, rayon, glass, ceramic materials, and the like or nonwoven fabric such as air laid webs of natural or synthetic fibers or blends of these.
• the backing may also be formed of metal, metalized polymer films, or ceramic sheet materials may take the form of any article conventionally known to be utilized with PSA compositions such as labels, tapes, signs, covers, marking indicia, and the like.
• acrylic PSA compositions are coated on a substrate using conventional coating techniques modified as appropriate to the particular substrate.
• these compositions can be applied to a variety of solid substrates by methods such as roller coating, flow coating, dip coating, spin coating, spray coating knife coating, and die coating. These various methods of coating allow the compositions to be placed on the substrate at variable thicknesses thus allowing a wider range of use of the compositions. Coating thicknesses may vary from a few microns to a few hundred microns. Those of ordinary skill in the art are capable of selecting an appropriate coating technique to match the backing and desired end use application.
• the backing for the acrylic PSA may also comprise a release-coated substrate.
• a release-coated substrate are typically employed when an adhesive transfer tape is provided.
• release-coated substrates are well known in the art and include, by way of example, silicone-coated kraft paper and the like.
• the acrylic PSA of this disclosure resists both polar and non-polar solvents. Due to the potentially diverse applications, the acrylic PSA's may be exposed to a variety of different solvents including alcohol, skin oils such as sebum and oleic acid, water, hydrocarbon fluids, etc. This range of solvents represents both polar and non-polar solvents.
• Polar and non-polar solvents can be characterized by their solubility parameters. Non-polar, or lower polarity, solvents (eg. skin oils, hydrocarbons) have lower solubility parameters and polar, or higher polarity, solvents (eg. water, alcohol) have higher solubility parameters. Alternatively, one may consider characterizing polar a non-polar solvents by their respective dielectric constants.
• One method of characterizing solvent resistance is by measuring the extent of swelling of the adhesive after it has been immersed in a given solvent for a period of time at a specified temperature.
• An acrylic PSA that exhibits a higher amount of swelling is certainly less resistant to that particular solvent.
• One method of characterizing solvent resistance is by measuring the extent of swelling of the adhesive after it has been immersed in a given solvent for some period of time. The higher the amount of swelling the less resistant to the solvent the material is considered to be.
• ASTM D543-06 "Standard Practices for Evaluating the Resistance of Plastics to Chemical Reagents" is one example of such a test. In the present disclosure,. ⁇ method of characterizing swelling involves the Swelling Ratio Test, noted below in the Examples.
• acrylic PSA's of this disclosure exhibit a resistance to both polar and non-polar solvents.
• the resistance to both polar and non-polar solvents is demonstrated by a solvent swell ratio of 1.8 or less after immersion in a 1 : 1 water and isopropyl alcohol mixture in accordance with the Swelling Ratio Test and solvent swell ratio of 1.5 or less after immersion in oleic acid in accordance with the Swelling Test.
• Conventional acrylic PSA's generally do not exhibit such a strong resistance to both types of solvents.
• the acrylic PSA's ability to resist a wide array of solvents is not the only defining attribute of the composition of this disclosure.
• the acrylic PSA's necessarily maintain a sufficient level of adhesion.
• the acrylic PSA has at least a 1 second creep compliance of greater than lxlO "6 cm2 /dyne. Adhesion characteristics are determined through peel adhesion testing. Some embodiments of the acrylic PSA exhibit a peel adhesion strength of 0.7 N/mm or greater in accordance with the Peel Adhesion Test. The Peel Adhesion Test is noted below in the Examples.
• the Tg of the acrylic PSA's are generally higher than conventional acrylic PSA's.
• acrylic PSA's produced according to this disclosure exhibit a Tg of about -20 °C, while other conventional PSA's may be as low as -40 °C.
• the acrylic PSA's disclosed herein are well suited for application areas that include health care such as, for example, wound dressings and garment attachments; industrial such as, for example, floor marking tapes and window sealing tapes; and personal safety items such as for example, protective clothing.
• health care such as, for example, wound dressings and garment attachments
• industrial such as, for example, floor marking tapes and window sealing tapes
• personal safety items such as for example, protective clothing.
• the acrylic PSA's solvent resistant characteristics over different types of solvents render it particularly suited for the noted applications.
• a one-liter glass bottle was charged with BA (50 g), MA (50 g), HEA (0.20 g), EtOAc (146 g), IPA (4.0 g) and VAZO-67 (0.250 g).
• the bottle was purged with nitrogen to remove oxygen and then sealed.
• the sealed bottle was placed in a water bath heated to 60 °C. The sealed bottle was then rotated for 24 hours. A clear and viscous polymer solution was obtained.
• a portion of the polymer solution (26.8 g) was mixed with Desmodur L-75 (0.21 g) and EtOAc (10 g) in a glass jar until a homogeneous solution was obtained. This solution was then coated on to a T-30 polyester release liner at a thickness of about 50 microns and dried in a 65 °C oven for 30 minutes to form a pressure sensitive adhesive tape.
• a pressure sensitive adhesive tape was produced by laminating the above coated sample onto the PET film described in the Materials table above. A sample measuring 12.5 millimeters wide by 30.5 cm long was cut and the release liner removed. The exposed adhesive surface of the adhesive tape was adhered along the length of a stainless steel plate (Type 304 having a bright annealed finish, obtained from Chemlnstruments, Incorporated, Fairfield, OH) measuring 5.1 cm wide by 12.7 cm long by 0.12 centimeters thick using a 2.0 kg rubber roller and five passes to provide a test specimen. The plate was cleaned prior to applying the tape by wiping with acetone once then with heptane three times using a tissue paper (trade designation KIMWIPE the tape sample by first, available from Kimberly-Clark
• test samples were evaluated for peel adhesion strength using a tensile tester (MTS Insight, available from MTS Systems, Corporation, Eden Prairie, MN) equipped with 1000 N load cell, using a crosshead speed of 30.5 cm/minute, at an angle of 180° with the test specimen held in the bottom clamp and the tail in the top clamp. The average of two test specimens was reported in N/millimeter (N/mm).
• MTS Insight available from MTS Systems, Corporation, Eden Prairie, MN
• Comparative Examples 1-3 failed either in polar or non-polar solvent swelling test.

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• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Health & Medical Sciences (AREA)
• Medicinal Chemistry (AREA)
• Polymers & Plastics (AREA)
• Adhesive Tapes (AREA)
• Adhesives Or Adhesive Processes (AREA)
• Laminated Bodies (AREA)
• Polyurethanes Or Polyureas (AREA)
• Addition Polymer Or Copolymer, Post-Treatments, Or Chemical Modifications (AREA)

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• 2015
  • 2015-11-25 CN CN201580064870.8A patent/CN107001900A/zh active Pending
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  • 2015-11-25 US US15/520,892 patent/US20180022972A1/en not_active Abandoned
  • 2015-11-25 EP EP15805717.4A patent/EP3227398B1/en active Active
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