EP0084360B1 — Sheet for forming sleeve and process for producin…

Claim 1

Independent Claim 149 words

A sleeve comprising a laminated sheet (S) having two films, said laminated sheet having a different shrinkage rate in different directions, characterized in that said films comprise polystyrene, one of the said films (1) being a more highly shrinkable foamed film, and one of said films being a lesser shrinkable non-foamed film (2), said foamed film having a surface skin (11) thicker on its side opposite to that laminated to said non-foamed film; flow-direction ends of said laminated sheet (S) being bonded together so that the thicker surface skin of said foamed film (1) faces the interior of said sleeve; and said laminated sheet (S) having a flow-direction shrinkage rate of 60% or less and a widthwise shrinkage rate of 10%. or less, said flow-direction rate being greater than said widthwise shrinkage rate, the said shrinkage rates being obtainable by heating at 130°C for twelve seconds in an oven.

Claim 2

Dependent Claim 149 words

A sleeve comprising a laminated sheet (S) having two films, said laminated sheet having a different shrinkage rate in different directions, characterized in that said films comprise polystyrene, one of the said films (1) being a more highly shrinkable foamed film, and one of said films being a lesser shrinkable non-foamed film (2), said foamed film having a surface skin (11) thicker on its side opposite to that laminated to said non-foamed film; flow-direction ends of said laminated sheet (S) being bonded together so that the thicker surface skin of said foamed film (1) faces the interior of said sleeve; and said laminated sheet (S) having a flow-direction shrinkage rate of 60% or less and a widthwise shrinkage rate of 10%. or less, said flow-direction rate being greater than said widthwise shrinkage rate, the said shrinkage rates being obtainable by heating at 130°C for twelve seconds in an oven.

Claim 3

Dependent Claim 27 words

A sleeve as claimed in claim 1 characterised in that said non-foamed film (2) also comprises a rubber in an amount not more than 30% by weight.

Claim 4

Dependent Claim 28 words

A sleeve as claimed in claim 1 or 2 characterised in that said non-foamed film (2) also comprises a titanium white in an amount of 5% or less.

Claim 5

Dependent Claim 41 words

A sleeve as claimed in any one of claims 1 to 3 characterised in that said non-foamed film (2) also comprises a polyethylene wax in an amount of 0.03 to 6.0% by weight, based on the weight of said polystyrene resin.

Claim 6

Dependent Claim 32 words

A sleeve as claimed in any one of claims 1 to 4 characterised in that said non-foamed film (2) also comprises a polyolefin resin in an amount of not less than 10%.

Claim 7

Dependent Claim 34 words

A sleeve as claimed in any one of claims 1 to 5 characterised in that said foamed polystyrene film (1) also comprises a rubber in an amount of from 0.5 to 25% by weight.

Claim 8

Dependent Claim 48 words

A sleeve as claimed in any one of claims 1 to 6 characterised in that at least one of said foamed film (1) and said non-foamed film (2) also comprises 0.01 to 3% by weight of plasticizers having a solubility parameter in the range of 8 to 11.0.

Claim 9

Dependent Claim 32 words

A sleeve as claimed in any one of claims 1 to 7 characterised in that said laminated sheet (S) has been compressed by 3 to 30% in the direction of its thickness.

Claim 10

Dependent Claim 35 words

A sleeve as claimed in any one of claims 1 to 8 characterised in that said laminated sheet has an elongation of not less than 13% and a longitudinal tensile strength of 1.5.to 7 Kg.

Claim 11

Dependent Claim 152 words

A process for producing a sheet (S) for forming a sleeve in which a foamed film (1) and a non-foamed film (2) are concurrently extruded characterized by said foamed film and said non-foamed film being polystyrene films; cooling said foamed film (1) more quickly than said non-foamed film (2), so that said foamed film (1) has a higher shrinkage rate than said non-foamed film (2), and said foamed film (1) has a surface skin layer (11) thicker on its side opposite that laminated to said non-foamed film (2); and stretching the laminated sheet (S) at different rates relative to the flow and widthwise directions of said laminated sheet, so that the resulting flow-direction shrinking rate is greater than the widthwise shrinking rate and is 60% or less and said widthwise shrinking rate is 10% or less, the said shrinkage rates being obtainable by heating at 130°C for twelve seconds in an oven.

Claim 12

Dependent Claim 152 words

A process for producing a sheet (S) for forming a sleeve in which a foamed film (1) and a non-foamed film (2) are concurrently extruded characterized by said foamed film and said non-foamed film being polystyrene films; cooling said foamed film (1) more quickly than said non-foamed film (2), so that said foamed film (1) has a higher shrinkage rate than said non-foamed film (2), and said foamed film (1) has a surface skin layer (11) thicker on its side opposite that laminated to said non-foamed film (2); and stretching the laminated sheet (S) at different rates relative to the flow and widthwise directions of said laminated sheet, so that the resulting flow-direction shrinking rate is greater than the widthwise shrinking rate and is 60% or less and said widthwise shrinking rate is 10% or less, the said shrinkage rates being obtainable by heating at 130°C for twelve seconds in an oven.

Claim 13

Dependent Claim 106 words

A laminate comprising a sheet (S) having a foamed film (1) and a non-foamed film (2) characterized by said films comprising polystyrene, said foamed film being more highly shrinkable and said non-foamed film being less shrinkable, by said foamed film having a surface skin (11) thicker on its side opposite that laminated to said non-foamed film; and said laminated sheet (S) having a flbw-direction shrinkage rate of 60% or less and a widthwise shrinkage rate of 10% or less, said flow-direction shrinkage rate being greater than said widthwise shrinkage rate, the said shrinkage rates being obtainable by heating at 130°C for twelve seconds in an oven.

Claim 14

Dependent Claim 106 words

A laminate comprising a sheet (S) having a foamed film (1) and a non-foamed film (2) characterized by said films comprising polystyrene, said foamed film being more highly shrinkable and said non-foamed film being less shrinkable, by said foamed film having a surface skin (11) thicker on its side opposite that laminated to said non-foamed film; and said laminated sheet (S) having a flbw-direction shrinkage rate of 60% or less and a widthwise shrinkage rate of 10% or less, said flow-direction shrinkage rate being greater than said widthwise shrinkage rate, the said shrinkage rates being obtainable by heating at 130°C for twelve seconds in an oven.

Claim 15

Dependent Claim 31 words

A laminate as claimed in claim 11 further characterised by the flow direction edges of said sheet being bonded together so as to form a sleeve enclosing a glass bottle (G).

Claim 16

Dependent Claim 21 words

A laminate as claimed in claim 12 characterised in that the sheet is adhered to the bottle (G) by heat shrinking.

Sheet for forming sleeve and process for producing the same

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