Film for packaging light-sensitive materials

Claim 2

A film for packaging light-sensitive materials having at least one light-shielding film comprising polyethylene polymer and further comprising 1-30 weight % light shielding material therein, wherein not less than 50 weight % of the total polyethylene polymer is linear low density polyethylene (L-LDPE) which is a copolymer of ethylene and an alpha olefin of 3 to 13 carbon atoms.

Claim 3

The film as defined in claim 1, wherein the total thickness of the film for packaging light-sensitive materials is 58-130 microns.

Claim 4

A film for packaging light-sensitive materials having at least one light-shielding film comprising polyethylene polymer and further comprising 1-30 weight % light shielding material therein, wherein not less than 50 weight % of the total polyethylene polymer is linear low density polyethylene (L-LDPE) which is a copolymer of ethylene and an alpha olefin of 3 to 13 carbon atoms, and at least one additional layer selected from the group consisting of thermoplastic resin film, paper, colored paper, synthetic paper, cellophane, bonded fabric, foamed sheet, paper board, K-liner, triacetate film, diacetate film, polyvinyl alcohol film, metal disposited paper, and aluminum layer.

Claim 5

A film for packaging light-sensitive materials having at least one light-shielding film comprising polyethylene polymer and further comprising 1-30 weight % light shielding material therein, wherein not less than 50 weight % of the total polyethylene polymer is linear low density polyethylene (L-LDPE) which is a copolymer of ethylene and an alpha olefin of 3 to 13 carbon atoms, and at least one additional layer selected from the group consisting of thermoplastic resin film, paper, colored paper, synthetic paper, cellophane, bonded fabric, foamed sheet, paper board, K-liner, triacetate film, diacetate film, polyvinyl alcohol film, metal disposited paper, and aluminum layer.

Claim 6

The film as defined in claim 3, wherein said aluminum layer is an aluminum foil.

Claim 7

The film as defined in claim 3, wherein said aluminum layer is a deposited aluminum layer.

Claim 8

The film as defined in claim 3, wherein the light-shielding film and the additional layer are formed by coextrusion.

Claim 9

The film as defined in claim 3, wherein the additional layer is formed by extrusion.

Claim 10

The film as defined in claim 3, wherein said α-olefin approximately amounts to 0.5-10 weight % of L-LDPE.

Claim 11

The film as defined in claim 1 or 3, wherein said α-olefin has 4-10 carbon atoms.

Claim 12

The film as defined in claim 1 or 3, wherein said α-olefin is at least one of the group consisting of 1-butene, 1-octene, 1-hexene and 4-methyl-1-pentene.

Claim 13

The film as defined in claim 1 or 3, wherein L-LDPE approximately has a density of 0.91-0.95 g/cm 3 .

Claim 14

The film as defined in claim 1 or 3, wherein the light-shielding material is present in an amount of 3-10 weight % in the light-shielding film.

Claim 15

The film as defined in claim 1 or 3, wherein the light-shielding film is produced by inflation molding.

Claim 16

The film as defined in claim 1 or 3, wherein the light-shielding film is produced by extrusion.

Claim 17

The film as defined in claim 1 or 3, wherein the balance of said polyethylene polymer other than L-LDPE is high pressure low density polyethylene (LDPE).

Claim 18

The film as defined in claim 15, wherein LDPE is present in the amount of 5-25 weight % in the polyethylene polymer.

Claim 19

The film as defined in claim 1 or 3, wherein the L-LDPE is present in the amount of 60-97 weight % of the polyethylene polymer.

Claim 20

The film as defined in claim 17, wherein the L-LDPE is present in the amount of 80-90 weight % in the polyethylene polymer.

Claim 21

The film as defined in claim 3, wherein an adhesive is used for lamination.

Claim 22

The film as defined in claim 19, wherein said adhesive contains light-shielding material.

Claim 23

The film defined in claim 3, wherein said flexible sheet contains light-shielding material.

Claim 24

The film as defined in any of claim 1, 3, 19, 20 or 4, wherein said light-shielding material is non-light-transmitting powder or particle material dispersed in said polyethylene polymer.

Claim 25

The film as defined in claim 22, wherein said light-shielding material comprises inorganic and/or organic pigment(s).

Claim 26

The film as defined in claim 23, wherein said pigment(s) comprise(s) one or more selected from the group consisting of carbon black, iron oxide, zinc white, titanium oxide, aluminum powder, aluminum paste, calcium carbonate, barium sulfate, chrome yellow red iron oxide, cobalt blue, copper phthalocyanine, monoazo- and polyazo-compounds, and aniline black.

Claim 27

The film as defined in claim 24, wherein the pigment(s) comprise(s) at least carbon black.