Claims
- 1. Sheet material adapted to make bonded electrical connections to a substrate, the sheet material comprising
- an adhesive layer which softens to an adhesive condition upon heating to an elevated temperature, and subsequently hardens to exhibit a firm and substantially nonflowable condition at room temperature; and
- a monolayer of discrete separated electrically conductive elements dispersed in the adhesive layer; the average thickness of the adhesive layer being between about 60 and 95 percent of the average thickness of the electrically conductive elements; and the top edge of substantially each element being higher than at least part of the exterior surface of the adhesive layer surrounding the element.
- 2. Sheet material of claim 1 in which the electrically conductive elements are separated on average by a distance equal to at least the average diameter of the elements.
- 3. Sheet material of claim 1 in which the exterior surface of the adhesive layer is configured so that at least part of the exterior surface of the adhesive layer is recessed below other areas of the surface.
- 4. Sheet material of claim 1 in which the adhesive layer is a hot-tackifying adhesive which exhibits a Probe Tack Value of at least 75 grams of force at a temperature of 40.degree. C. or more.
- 5. Sheet material of claim 1 in which the adhesive layer comprises one or more acrylic polymers and
- (1) acrylic ester monomer provides at least 50 mol percent of the one or more acrylic polymers of the adhesive layer,
- (2) said one or more acrylic polymers have a T.sub.g or a weight-averaged T.sub.g of -10.degree. to 80.degree. C., and
- (3) said adhesive layer has
- (a) a Probe Tack Value of less than 75 gf at 20.degree. C.,
- (b) Probe Tack Values of at least 75 gf over a range of at least 50.degree. C., which values remain substantially constant after 30 days at 40.degree. C., and
- (c) a Shear Value of at least 25 minutes at 65.degree. C.; and ethyl esters of itaconic acid and the mono- and di ethyl esters of maleic acid.
- 6. Sheet material of claim 5 in which the adhesive layer comprises one or more acrylic copolymer of monomers, up to 50 mol % of which is at least one copolymerizable monomer selected from acrylic acid, methacrylic acid, itaconic acid, maleic acid, maleic anhydride, amides of said acids, acrylonitrile, methacrylonitrile, and N-vinyl-2-pyrrolidone.
- 7. Sheet material of claim 5 in which the acrylic ester monomer is selected from alkyl acrylates having 1-8 carbon atoms in their alkyl groups, alkyl methacrylates having 1-8 carbon atoms in their alkyl groups, bornyl acrylates, bornyl methacrylates, 2-phenoxyethyl acrylate, 2-phenoxymethyl acrylate, the mono- and di-methyl and ethyl esters of itaconic acid, and the mono- and di-methyl and ethyl esters of maleic acid.
- 8. Sheet material of claim 5 in which at least one of styrene, vinyl acetate and vinyl chloride comprises up to 5 mol % of the total monomers.
- 9. Sheet material of claim 1 in which the adhesive layer comprises an acrylic-silane interpolymer of primarily acrylic ester monomer interacted with organosilane in an amount of at least 0.2 part per 100 parts by weight of total monomer, which interpolymer has a T.sub.g of -10.degree. to 80.degree. C.
- 10. Sheet material of claim 9 in which the acrylic ester monomer is selected form alkyl acrylates and methacrylates having 1-8 carbon atoms in their alkyl groups; bornyl acrylates and methacrylates; 2-phenoxyethyl acrylate and methacrylate; the mono- and di methyl and surface of the adhesive layer surrounding the particle, whereby after adhesion of the adhesive layer to a substrate the film conforms around the particle and the particle is held against the substrate.
- 11. Sheet material of claim 9 in which the amount of organosilane is from 0.5 to 4 parts per 100 parts by weight of total monomer.
- 12. Sheet material of claim 9 in which the acrylic-silane interpolymer comprises monomers, up to 50 mol % of which is at least one copolymerizable monomer selected from acrylic acid, methacrylic acid, itaconic acid, maleic acid, maleic anhydride, amides of said acids, acrylonitrile, methacrylonitrile, and N vinyl-2-pyrrolidone.
- 13. Sheet material of claim 12 in which styrene, vinyl acetate and vinyl chloride comprise up to 5 mol % of the total monomers.
- 14. Sheet material of claim 1 which includes a flexible backing on which the adhesive layer is carried and an electrically conductive layer between the flexible backing and the adhesive layer.
- 15. Sheet material of claim 14 in which the backing is a polyester film of about 50 micrometers thickness or less.
- 16. Sheet material of claim 14 which includes a plurality of electrically conductive layers in the form of narrow parallel electrically conductive stripes.
- 17. Sheet material of claim 16 in which electrically conductive elements are disposed in the adhesive layer only over the electrically conductive stripes.
- 18. Sheet material of claim 16 in which the exterior surface of the adhesive layer is configured so that at least part of the exterior surface that overlies spaces between the conductive stripes is recessed below other areas of the surface.
- 19. Sheet material adapted to make bonded electrical connections to a substrate, the sheet material comprising
- a flexible polyethylene terephthalate film about 25 micrometers or less in thickness and carrying an electrically conductive metal layer thereon;
- an adhesive layer carried on the film which softens to a tacky adhesive condition upon heating to an elevated temperature, and upon cooling to room temperature assumes a firm and substantially nonflowable condition; and
- a monolayer of discrete separated electrically conductive particles distributed in the adhesive layer and separated on average by a distance equal to at least the average diameter of the particles;
- the adhesive layer having an average thickness between about 60 to 95 percent of the average thickness of the particles, and the top edge of substantially each particle being higher than at least part of the exterior said adhesive layer adheres well to a clean substrate upon contact at any temperature within said 50.degree. C. range.
- 20. The sheet material of claim 19 in which the average thickness of the adhesive layer is between 70 and 80 percent of the average thickness of the electrically conductive particles.
- 21. Sheet material of claim 19 in which the average thickness of the electrically conductive particles is 100 micrometers or less.
- 22. Sheet material of claim 20 in which the adhesive layer is a hot tackifying adhesive which exhibits a Probe Tack Value of at least 75 grams of force at a temperature of 40.degree. C. or more.
- 23. Sheet material of claim 19 in which the adhesive layer comprises an acrylic-silane interpolymer of primarily acrylic ester monomer interacted with organosilane in an amount of at least 0.2 part per 100 parts by weight of total monomer, which interpolymer has a T.sub.g of -10.degree. to 80.degree. C.
- 24. Sheet material of claim 19 in which the electrically conductive elements are separated on average by at least about four times their average diameter.
- 25. Sheet material of claim 19 in which there are a plurality of electrically conductive metal layers carried on the polyethylene terephthalate film, said layers taking the form of narrow elongated electrically conductive stripes.
- 26. Sheet material of claim 25 in which the exterior surface of the adhesive layer is configured so that at least part of the exterior surface that overlies spaces between the conductive stripes is recessed below other areas of the surface.
- 27. Sheet material of claim 19 in which the adhesive layer comprises one or more acrylic polymers and
- (1) acrylic ester monomer provides at least 50 mol percent of the one or more acrylic polymers of the adhesive layer,
- (2) said one or more acrylic polymers have a T.sub.g or a weight-averaged T.sub.g of -10.degree. to 80.degree. C., and
- (3) said adhesive layer has
- (a) a Probe Tack Value of less than 75 gf at 20.degree. C.,
- (b) Probe Tack Values of at least 75 gf over a range of at least 50.degree. C., which values remain substantially constant after 30 days at 40.degree. C., and
- (c) a Shear Value of at least 25 minutes at 65.degree. C.; and
- said adhesive layer adheres well to a clean substrate upon contact at any temperature within said 50.degree. C. range.
- 28. Sheet material of claim 27 in which the adhesive layer comprises one or more acrylic copolymer of monomers, up to 50 mol % of which is at least one copolymerizable monomer selected from acrylic acid, methacrylic acid, itaconic acid, maleic acid, maleic anhydride, amides of said acids, acrylonitrile, methacrylonitrile, and N-vinyl-2-pyrrolidone.
- 29. Sheet material of claim 27 in which the acrylic ester monomer is selected from alkyl acrylates having 1-8 carbon atoms in their alkyl groups, alkyl methacrylates having 1-8 carbon atoms in their alkyl groups, bornyl acrylates, bornyl methacrylates, 2-phenoxyethyl acrylate, 2-phenoxymethyl acrylate, the mono- and di-methyl and ethyl esters of itaconic acid, and the mono- and di-methyl and ethyl esters of maleic acid.
- 30. Sheet material of claim 27 in which at least one of styrene, vinyl acetate and vinyl chloride comprises up to 5 mol % of the total monomers.
- 31. Sheet material adapted to make bonded electrical connections to a substrate, the sheet material comprising
- a flexible backing carrying narrow electrically conductive metal stripes thereon;
- an adhesive layer carried on the backing over said stripes which softens to an adhesive condition upon heating to an elevated temperature, and subsequently hardens to exhibit a firm and substantially nonflowable condition at room temperature;
- a monolayer of discrete separated electrically conductive elements distributed in the adhesive layer and separated on average by a distance equal to at least the average diameter of the elements;
- the conductive elements having an average thickness greater than the average thickness of the adhesive layer, and the top edge of substantially each conductive element being higher than at least part of the exterior surface of the adhesive layer surrounding the conductive element, whereby after adhesion of the adhesive layer to a substrate the backing conforms around the conductive element and the conductive element is held against the substrate.
- 32. The sheet material of claim 31 in which the average thickness of the adhesive layer is between 60 and 90 percent of the average thickness of the electrically conductive elements.
- 33. Sheet material of claim 31 in which the adhesive layer is a hot tackifying adhesive which exhibits a Probe Tack Value of at least 75 grams of force at a temperature of 40.degree. C. or more.
- 34. Sheet material of claim 31 in which the adhesive layer comprises an acrylic-silane interpolymer of primarily acrylic ester monomer interacted with organosilane in an amount of at least 0.2 part per 100 parts by weight of total monomer, which interpolymer has a T.sub.g of -10.degree. to 80.degree. C.
- 35. Sheet material of claim 31 in which the exterior surface of the adhesive layer is configured so that at least part of the exterior surface that overlies spaces between the conductive stripes is recessed below other areas of the surface.
- 36. Sheet material of claim 31 in which the adhesive layer comprises one or more acrylic polymers and
- (1) acrylic ester monomer provides at least 50 mol percent of the one or more acrylic polymers of the adhesive layer.
- (2) said one or more acrylic polymers have a T.sub.g or a weight-averaged T.sub.g of -10.degree. to 80.degree. C., and
- (3) said adhesive layer has
- (a) a Probe Tack Value of less than 75 gf at 20.degree. C.,
- (b) Probe Tack Values of at least 75 gf over a range of at least 50.degree. C., which values remain substantially constant after 30 days at 40.degree. C., and
- (c) A Shear Value of at least 25 minutes at 65.degree. C.; and
- said adhesive layer adheres well to a clean substrate upon contact at any temperature within said 50.degree. C. range.
- 37. Sheet material of claim 36 in which the adhesive layer comprises one or more acrylic copolymer of monomers, up to 50 mol % of which is at least one copolymerizable monomer selected from acrylic acid, methacrylic acid, itaconic acid, maleic acid, maleic anhydride, amides of said acids, acrylonitrile, methacrylonitrile, and N-vinyl-2-pyrrolidone.
- 38. Sheet material of claim 36 in which the acrylic ester monomer is selected from alkyl acrylates having 1-8 carbon atoms in their alkyl groups, alkyl methacrylates having 1-8 carbon atoms in their alkyl groups, bornyl acrylates, bornyl methacrylates, 2-phenoxyethyl acrylate, 2-phenoxymethyl acrylate, the mono- and di-methyl and ethyl esters of itaconic acid, and the mono- and di-methyl and ethyl esters of maleic acid.
Parent Case Info
This is a continuation in part of application Ser. No. 451,050 filed Dec. 20, 1982, now abandoned.
US Referenced Citations (11)
Foreign Referenced Citations (3)
Number |
Date |
Country |
2018774 |
Apr 1971 |
DEX |
2758491 |
Jul 1979 |
DEX |
2048582 |
Dec 1980 |
GBX |
Continuation in Parts (1)
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Number |
Date |
Country |
Parent |
451050 |
Dec 1982 |
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