Curl-resistant printing sheet for labels and tags

Claim 2

A durable sheet adapted for use as a label which does not curl when heated to temperatures normally encountered in laser or thermal transfer printing, the sheet including at least three layers layer A, which consists essentially of at least one base layer consisting of a paper, a synthetic paper or a coated film; layer B, which consists essentially of at least one print receiving layer consisting of a paper, a synthetic paper or a coated film, wherein layer B is adhered to the top face of layer A; and layer C, which consists essentially of at least one backing layer consisting of a paper, a synthetic paper or a coated film, wherein layer C is adhered to the bottom face of layer A; and wherein layer B and layer C have the same or substantially the same thermal elongation or contraction characteristics; and wherein the top surface of layer A comprises a release agent, the bottom surface of layer B comprises a pressure sensitive adhesive and layer C is permanently adhered to layer A.

Claim 3

A durable sheet adapted for use as a label which does not curl when heated to temperatures normally encountered in laser or thermal transfer printing, the sheet including at least three layers comprised of: layer A, which consists essentially of at least one base layer consisting of comprising a paper, a synthetic paper or a coated film; layer B, which consists essentially of at least one print receiving layer consisting of a paper, a synthetic paper or a coated film, wherein layer B is adhered to the top face of layer A; and layer C, which consists essentially of at least one backing layer consisting of a paper, a synthetic paper or a coated film, wherein layer C is adhered to the bottom face of layer A; and wherein layer B and layer C have the same or substantially the same thermal elongation or contraction characteristics; and wherein the top surface of layer C comprises a release agent, the bottom surface of layer A comprises a pressure sensitive adhesive and layer B is permanently adhered to layer A.

Claim 4

A durable sheet adapted for use as a label which does not curl when heated to temperatures normally encountered in laser or thermal transfer printing, the sheet including at least three layers comprised of: layer A, which consists essentially of at least one base layer consisting of comprising a paper, a synthetic paper or a coated film; layer B, which consists essentially of at least one print receiving layer consisting of a paper, a synthetic paper or a coated film, wherein layer B is adhered to the top face of layer A; and layer C, which consists essentially of at least one backing layer consisting of a paper, a synthetic paper or a coated film, wherein layer C is adhered to the bottom face of layer A; and wherein layer B and layer C have the same or substantially the same thermal elongation or contraction characteristics; and wherein the top surface of layer C comprises a release agent, the bottom surface of layer A comprises a pressure sensitive adhesive and layer B is permanently adhered to layer A.

Claim 5

A durable sheet for labels or tags which does not curl when heated to temperatures normally encountered in laser or thermal transfer printing, the sheet including at least three layers comprised of: layer A, which consists essentially of at least one base layer consisting of comprising a paper, a synthetic paper or a coated film; layer B, which consists essentially of at least one print receiving layer consisting of a paper, a synthetic paper or a coated film, wherein layer B is adhered to the top face of layer A; and layer C, which consists essentially of at least one backing layer consisting of a paper, a synthetic paper or a coated film, wherein layer C is adhered to the bottom face of layer A, and wherein layer B and layer C have the same or substantially the same thermal elongation or contraction characteristics; and wherein layer A comprises a thermoplastic resin, and layer B and layer C comprise a polyolefin.

Claim 6

A durable sheet for labels or tags which does not curl when heated to temperatures normally encountered in laser or thermal transfer printing, the sheet including at least three layers comprised of: layer A, which consists essentially of at least one base layer consisting of comprising a paper, a synthetic paper or a coated film; layer B, which consists essentially of at least one print receiving layer consisting of a paper, a synthetic paper or a coated film, wherein layer B is adhered to the top face of layer A; and layer C, which consists essentially of at least one backing layer consisting of a paper, a synthetic paper or a coated film, wherein layer C is adhered to the bottom face of layer A, and wherein layer B and layer C have the same or substantially the same thermal elongation or contraction characteristics; and wherein layer A comprises a thermoplastic resin, and layer B and layer C comprise a polyolefin.

Claim 7

A durable sheet for labels or tags which does not curl when heated to temperatures normally encountered in laser or thermal transfer printing, the sheet including at least three layers comprised of: layer A, which consists essentially of at least one base layer consisting of comprising a paper, a synthetic paper or a coated film; layer B, which consists essentially of at least one print receiving layer consisting of a paper, a synthetic paper or a coated film, wherein layer B is adhered to the top face of layer A; and layer C, which consists essentially of at least one backing layer consisting of a paper, a synthetic paper or a coated film, wherein layer C is adhered to the bottom face of layer A, and wherein layer B and layer C have the same or substantially the same thermal elongation or contraction characteristics; and wherein layer A comprises a thermoplastic polyester, layer B comprises a polyolefin and layer C comprises a thermoplastic resin coating.

Claim 8

A durable sheet for labels or tags which does not curl when heated to temperatures normally encountered in laser or thermal transfer printing, the sheet including at least three layers comprised of: layer A, which consists essentially of at least one base layer consisting of comprising a paper, a synthetic paper or a coated film; layer B, which consists essentially of at least one print receiving layer consisting of a paper, a synthetic paper or a coated film, wherein layer B is adhered to the top face of layer A; and layer C, which consists essentially of at least one backing layer consisting of a paper, a synthetic paper or a coated film, wherein layer C is adhered to the bottom face of layer A, and wherein layer B and layer C have the same or substantially the same thermal elongation or contraction characteristics; and wherein layer A comprises a thermoplastic polyester, layer B comprises a polyolefin and layer C comprises a thermoplastic resin coating.

Claim 9

A durable sheet for labels or tags which does not curl when heated to temperatures normally encountered in laser or thermal transfer printing, the sheet including at least three layers comprised of: layer A, which consists essentially of at least one base layer consisting of comprising a paper, a synthetic paper or a coated film; layer B, which consists essentially of at least one print receiving layer consisting of a paper, a synthetic paper or a coated film, wherein layer B is adhered to the top face of layer A; and layer C, which consists essentially of at least one backing layer consisting of a paper, a synthetic paper or a coated film, wherein layer C is adhered to the bottom face of layer A, and wherein layer B and layer C have the same or substantially the same thermal elongation or contraction characteristics; and which also includes a laser printing enhancing coating on the print receiving face of layer B.

Claim 10

A durable sheet for labels or tags which does not curl when heated to temperatures normally encountered in laser or thermal transfer printing, the sheet including at least three layers comprised of: layer A, which consists essentially of at least one base layer consisting of comprising a paper, a synthetic paper or a coated film; layer B, which consists essentially of at least one print receiving layer consisting of a paper, a synthetic paper or a coated film, wherein layer B is adhered to the top face of layer A; and layer C, which consists essentially of at least one backing layer consisting of a paper, a synthetic paper or a coated film, wherein layer C is adhered to the bottom face of layer A, and wherein layer B and layer C have the same or substantially the same thermal elongation or contraction characteristics; and which also includes a laser printing enhancing coating on the print receiving face of layer B.

Claim 11

A sheet as defined in claim 5 wherein said printing enhancing coating comprises an acrylic, polyester or urethane resin filled with finely divided clay or silica.

Claim 12

A sheet as defined in claim 5 wherein layer A includes an effective amount of conductive filler for dissipating static changes developed during laser printing whereby sheet feeding and delivery problems are minimized.

Claim 13

A sheet as defined in claim 7 wherein said conductive filler comprises carbon black.

Claim 14

A sheet as defined in claim 5 wherein layer B has a ratio of thermal elongation or contraction in the range of from about 0.7 to about 1.3 with respect to 1.0 for layer C.

Claim 15

A label sheet as defined in claim 9 wherein said layer B has a ratio or thermal elongation or contraction of about 1.0 with respect to 1.0 for layer C.

Claim 16

A composite pressure sensitive label sheet which does not curl when heated to temperatures normally encountered in laser printing, said label sheet including at least three layers comprised of: layer A, which consists essentially of at least one base layer consisting of a tear resistant synthetic paper having a pressure sensitive adhesive on the bottom face thereof; layer B, which consists essentially of a print receiving tear resistant synthetic paper layer permanently adhered to the top face of layer A; and layer C, which consists essentially of a protective backing consisting of a paper layer or coated film releasably adhered to said pressure sensitive adhesive on the bottom face of layer A, said layer B and said layer C having the same or substantially the same thermal elongation or contraction characteristics.

Claim 17

A composite pressure sensitive label sheet which does not curl when heated to temperatures normally encountered in laser printing, said label sheet including at least three layers comprised of: layer A, which consists essentially of at least one base layer consisting of a tear resistant synthetic paper having a pressure sensitive adhesive on the bottom face thereof; layer B, which consists essentially of a print receiving tear resistant synthetic paper layer permanently adhered to the top face of layer A; and layer C, which consists essentially of a protective backing consisting of a paper layer or coated film releasably adhered to said pressure sensitive adhesive on the bottom face of layer A, said layer B and said layer C having the same or substantially the same thermal elongation or contraction characteristics.

Claim 18

A label sheet as defined in claim 11 wherein layers A and B are a single label.

Claim 19

A label sheet as defined in claim 11 wherein layer A comprises a thermoplastic polyester, and layer B and layer C comprise a polyolefin.

Claim 20

A label sheet as defined in claim 11 wherein layer A comprises a thermoplastic polyester, layer B comprises a polyolefin and layer C comprises a thermoplastic resin coating.

Claim 21

A label sheet as defined in claim 11 which also includes a laser printing enhancing coating on the print receiving face of layer B.

Claim 22

A label sheet as defined in claim 15 wherein said printing enhancing coating Comprises an acrylic, polyester or urethane resin filled with finely divided clay or silica.

Claim 23

A label sheet as defined in claim 11 wherein layer B is permanently adhered to layer A, with an adhesive layer which has high cohesive strength and low shear strength, whereby said layers A and B can move transversely under the influence of heat without parting.

Claim 24

A label sheet as defined in claim 11 wherein layer C is releasably adhered to the pressure sensitive adhesive on layer A with a release coating.

Claim 25

A label sheet as defined in claim 18 wherein said release coating comprises a silicone and said pressure sensitive adhesive layer has high cohesion and low shear strength whereby said layers C and A can move transversely under the influence of heat without parting.

Claim 26

A label sheet as defined in claim 11 wherein layers A and B are subdivided into a plurality of labels of substantially the same size.

Claim 27

A curl-free laser printed label sheet including at least three layers comprised of: layer A, which consists essentially of at least one base layer consisting of a tear resistant synthetic paper having a pressure sensitive adhesive on the bottom face thereof; layer B, which consists essentially of a laser printed tear resistant synthetic paper layer permanently adhered to the top face of layer A; and layer C, which consists essentially of a protective backing consisting of a paper layer or a coated film releasably adhered to said pressure sensitive adhesive on the bottom face of layer A, said layer B and said layer C having the same or substantially the same thermal elongation or contraction characteristics.

Claim 28

A curl-free laser printed label sheet including at least three layers comprised of: layer A, which consists essentially of at least one base layer consisting of a tear resistant synthetic paper having a pressure sensitive adhesive on the bottom face thereof; layer B, which consists essentially of a laser printed tear resistant synthetic paper layer permanently adhered to the top face of layer A; and layer C, which consists essentially of a protective backing consisting of a paper layer or a coated film releasably adhered to said pressure sensitive adhesive on the bottom face of layer A, said layer B and said layer C having the same or substantially the same thermal elongation or contraction characteristics.