Process for producing support for use in formation of polyurethan films

Claim 2

A process for producing a support suitable for use in the formation of polyurethane films, the support comprising a base, a releasing layer comprising a polymeric mixture (A) which comprises 95 to 65 parts by weight of polypropylene and 5 to 35 parts by weight of polyethylene and a resin (B) which forms an adhesion promoting layer, which process comprises co-extrusion coating the base with said mixture and simultaneously with said resin through the same T-die to form the releasing layer and the adhesion promoting layer on the base, said adhesion promoting layer promoting adhesiveness between the base and the releasing layer and being formed between them, the temperature of the mixture (A) as extruded through the T-die being controlled at below 300° C., while the temperature of the resin (B) as extruded through the T-die being controlled within the range between 290° and 330° C. and higher than the temperature of the mixture (A) as extruded.

Claim 3

A process for producing a polyurethane film comprising the steps of (a) coating a polyurethane resin onto a support comprising a base and a releasing layer, (b) peeling a polyurethane film formed on said releasing layer, characterized in that said releasing layer on said base comprises a polymeric mixture of 95 to 65 parts by weight of polypropylene and 5 to 35 parts by weight of polyethylene and said support is obtained by extrusion coating said base with said mixture through a T-die to form the releasing layer on said base and the temperature of said mixture as extruded through the T-die is controlled at below 300° C. after

Claim 4

A process for producing a polyurethane film comprising the steps of (a) coating a polyurethane resin onto a support comprising a base and a releasing layer, (b) peeling a polyurethane film formed on said releasing layer, characterized in that said releasing layer on said base comprises a polymeric mixture of 95 to 65 parts by weight of polypropylene and 5 to 35 parts by weight of polyethylene and said support is obtained by extrusion coating said base with said mixture through a T-die to form the releasing layer on said base and the temperature of said mixture as extruded through the T-die is controlled at below 300° C. after

Claim 5

A process in accordance with claim 2 wherein after the polyurethane resin is coated onto said releasing layer in the form of a solution, said support is dried with heat to form a polyurethane film on said releasing layer.

Claim 6

A process in accordance with claim 2 wherein, said coating of said polyurethane resin is carried out by extrusion coating, and after said extrusion coating of said polyurethane resin, the polyurethane resin is solidified by cooling.

Claim 7

A process in accordance with claim 2 wherein said polymeric mixture of polypropylene and polyethylene has a melt flow rate (MFR) of 10 to 40 g/10 minutes as measured in accordance with JIS K6758, a density of 0.89 to 0.92 g/cm 3 as measured in accordance with JIS K6758, and melting points of 100° to 130° C. based on the polyethylene and 155° to 165° C. based on the polypropylene as measured by a differential scanning calorimeter.

Claim 8

A process for producing a polyurethane film with a cloth stuck thereto comprising the steps of (a) coating a polyurethane resin onto a support comprising a base and a releasing layer, said polyurethane resin forming a polyurethane film, (b) applying an adhesive onto said polyurethane film formed on said releasing layer, (c) sticking a cloth to said adhesive, (d) solidifying said adhesive by drying said support with heat, and (e) peeling said polyurethane film together with said cloth, characterized in that said releasing layer comprises a polymeric mixture of 95 to 65 parts by weight of polypropylene and 5 to 35 parts by weight of polyethylene and said support is obtained by extrusion coating said base with said mixture through a T-die to form the releasing layer on said base and the temperature of said mixture as extruded through the T-die is controlled at below 300° C.

Claim 9

A process for producing a polyurethane film with a cloth stuck thereto comprising the steps of (a) coating a polyurethane resin onto a support comprising a base and a releasing layer, said polyurethane resin forming a polyurethane film, (b) applying an adhesive onto said polyurethane film formed on said releasing layer, (c) sticking a cloth to said adhesive, (d) solidifying said adhesive by drying said support with heat, and (e) peeling said polyurethane film together with said cloth, characterized in that said releasing layer comprises a polymeric mixture of 95 to 65 parts by weight of polypropylene and 5 to 35 parts by weight of polyethylene and said support is obtained by extrusion coating said base with said mixture through a T-die to form the releasing layer on said base and the temperature of said mixture as extruded through the T-die is controlled at below 300° C.

Claim 10

A process in accordance with claim 6 wherein after the polyurethane resin is coated onto said releasing layer in the form of a solution, said support is dried with heat to form said polyurethane film on said releasing layer.

Claim 11

A process in accordance with claim 6 wherein, said coating of said polyurethane resin is carried out by extrusion coating, and after said extrusion coating of said polyurethane resin, the polyurethane resin is solidified by cooling.

Claim 12

A process in accordance with claim 6, wherein said polymeric mixture of polypropylene and polyethylene has a melt flow rate (MFR) of 10 to 40 g/10 minutes as measured in accordance with JIS K6758, a density of 0.89 to 0.92 g/cm 3 as measured in accordance with JIS K6758, and melting points of 100° to 130° C. based on the polyethylene and 155° to 165° C. based on the polypropylene as measured by a differential scanning calorimeter.

Claim 13

A process for producing a polyurethane film comprising the steps of (a) coating a polyurethane resin onto a support comprising a base, an adhesion promoting layer and a releasing layer, and (b) peeling a polyurethane film formed on said releasing layer, characterized in that said releasing layer comprises a polymeric mixture of 95 to 65 parts by weight of polypropylene and 5 to 35 parts by weight of polyethylene (Mixture (A)) and said adhesion promoting layer comprises a resin (B), and that the base is co-extrusion coated with said mixture (A) and simultaneously with said resin (B) through the same T-die to form the releasing layer and the adhesion promoting layer on the base, and said adhesion promoting layer formed between the base and the releasing layer promoting adhesiveness between them, and the temperature of the mixture (A) as extruded through the T-die is controlled at below 300° C., while the temperature of the resin (B) as extruded through the T-die is controlled within the range between 290° and 330° C. and higher than the temperature of the mixture (A) as extruded.

Claim 14

A process for producing a polyurethane film comprising the steps of (a) coating a polyurethane resin onto a support comprising a base, an adhesion promoting layer and a releasing layer, and (b) peeling a polyurethane film formed on said releasing layer, characterized in that said releasing layer comprises a polymeric mixture of 95 to 65 parts by weight of polypropylene and 5 to 35 parts by weight of polyethylene (Mixture (A)) and said adhesion promoting layer comprises a resin (B), and that the base is co-extrusion coated with said mixture (A) and simultaneously with said resin (B) through the same T-die to form the releasing layer and the adhesion promoting layer on the base, and said adhesion promoting layer formed between the base and the releasing layer promoting adhesiveness between them, and the temperature of the mixture (A) as extruded through the T-die is controlled at below 300° C., while the temperature of the resin (B) as extruded through the T-die is controlled within the range between 290° and 330° C. and higher than the temperature of the mixture (A) as extruded.

Claim 15

A process in accordance with claim 9 wherein after the polyurethane resin is coated onto said releasing layer in the form of a solution, said support is dried with heat to form a polyurethane film on said releasing layer.

Claim 16

A process in accordance with claim 9 wherein, said coating of said polyurethane resin is carried out by extrusion coating, and after said extrusion coating of said polyurethane resin, the polyurethane resin is solidified by cooling.

Claim 17

A process in accordance with claim 10, wherein said polymeric mixture (A) has a melt flow rate (MFR) of 10 to 40 g/10 minutes as measured in accordance with JIS K6758, a density of 0.89 to 0.92 g/cm 3 as measured in accordance with JIS K6758, and melting points of 100° to 130° C. based on the polyethylene and 155° to 165° C. based on polypropylene as measured by a differential scanning calorimeter.

Claim 18

A process in accordance with claim 10, wherein the temperature of the mixture (A) as extruded through the T-die is controlled within the range between 250° and 290° C., while that of the resin (B) as extruded through the T-die is controlled within the range between 300° and 330° C.

Claim 19

A process in accordance with claim 10, wherein said resin (B) is selected from a mixture of polypropylene and polyethylene and a copolymer of ethylene and an α-olefin.

Claim 20

A process for producing a polyurethane film with a cloth stuck thereto comprising the steps of (a) coating a polyurethane resin onto a support comprising a base, an adhesion promoting layer, and a releasing layer, said polyurethane resin forming a polyurethane film, (b) applying an adhesive onto said polyurethane film formed on said releasing layer, (c) sticking a cloth to said adhesive, (d) solidifying said adhesive by drying said support with heat, and with (e) peeling said polyurethane film together with said cloth, characterized in that said releasing layer comprises a polymeric mixture of 95 to 65 parts by weight of polypropylene and 5 to 35 parts by weight of polyethylene (Mixture (A)) and said adhesion promoting layer comprises a resin (B), and that said base is co-extrusion coated with mixture (A) and simultaneously with said resin (B) through the same T-die to form the releasing layer and the adhesion promoting layer on the base and said adhesion promoting layer formed between the base and the releasing layer promotes adhesiveness between them and the temperature of the mixture (A) as extruded through the T-die is controlled at below 300° C., while the temperature of the resin (B) as extruded through the T-die is controlled within the range between 290 ° and 330° C. and higher than the temperature of the mixture (A) as extruded.

Claim 21

A process for producing a polyurethane film with a cloth stuck thereto comprising the steps of (a) coating a polyurethane resin onto a support comprising a base, an adhesion promoting layer, and a releasing layer, said polyurethane resin forming a polyurethane film, (b) applying an adhesive onto said polyurethane film formed on said releasing layer, (c) sticking a cloth to said adhesive, (d) solidifying said adhesive by drying said support with heat, and with (e) peeling said polyurethane film together with said cloth, characterized in that said releasing layer comprises a polymeric mixture of 95 to 65 parts by weight of polypropylene and 5 to 35 parts by weight of polyethylene (Mixture (A)) and said adhesion promoting layer comprises a resin (B), and that said base is co-extrusion coated with mixture (A) and simultaneously with said resin (B) through the same T-die to form the releasing layer and the adhesion promoting layer on the base and said adhesion promoting layer formed between the base and the releasing layer promotes adhesiveness between them and the temperature of the mixture (A) as extruded through the T-die is controlled at below 300° C., while the temperature of the resin (B) as extruded through the T-die is controlled within the range between 290 ° and 330° C. and higher than the temperature of the mixture (A) as extruded.

Claim 22

A process in accordance with claim 16 wherein after the polyurethane resin is coated onto said releasing layer in the form of a solution, said support is dried with heat to form said polyurethane film on said releasing layer.

Claim 23

A process in accordance with claim 16 wherein after the releasing layer is co-extrusion coated with the polyurethane resin, the polyurethane resin is solidified by cooling.

Claim 24

A process in accordance with claim 16, wherein said polymeric mixture (A) has a melt flow rate (MFR) of 10 to 40 g/10 minutes as measured in accordance with JIS K6758, a density of 0.89 to 0.92 g/cm 3 as measured in accordance with JIS K6758, and the melting points of 100° to 130° C. based on the polyethylene and 155° to 165° C. based on the polypropylene as measured by a differential scanning calorimeter.

Claim 25

A process in accordance with claim 16, wherein the temperature of the mixture (A) as extruded through he T-die is controlled within the range between 250° and 290° C., while that of the resin (B) as extruded through the T-die is controlled within the range between 300° and 330° C.

Claim 26

A process in accordance with claim 16, wherein said resin (B) is selected from a mixture of polypropylene and polyethylene and a copolymer of ethylene and an α-olefin.