GB2049479A

GB2049479A - Adhesively coated polyvinyl chloride foam

Info

Publication number: GB2049479A
Application number: GB7916239A
Authority: GB
Original assignee: KWIKSEAL SEALANT PRODUCTS Ltd
Current assignee: KWIKSEAL SEALANT PRODUCTS Ltd
Priority date: 1979-05-10
Filing date: 1979-05-10
Publication date: 1980-12-31
Also published as: DE2933487A1; GB2049479B

Abstract

A roll of p.v.c. foam sheet coated on one surface with a pressure- sensitive adhesive has a polyester film interliner. The liner is first coated with release agents on both sides so that one side has better release properties than the other. A roll of liner (1) is fed to a coater (2) at which foamable p.v.c. paste is spread on the side having the superior release properties. The foam is generated in an oven (3) and the exposed foam surface is then coated with an adhesive at a second coater (4). The adhesive is dried in an oven (5) and the film-foam-adhesive laminate wound on a roll (6) which can be cut into reels of strip material if required. Release characteristics are described with reference to a test procedure. <IMAGE>

Description

SPECIFICATION Adhesively coated polyvinyl chloride foam This invention relates to the manufacture of rolls of p.v.c. foam in strip or sheet form which is coated on one side with a pressure-sensitive adhesive. Such foam strips or sheets are commonly employed as a sealing material.

At present it is common to employ an interliner of paper when sheet p.v.c. foam is wound into a roll to prevent adjacent coils adhering together and to prevent the foam from stretching in use.

In accordance with the present invention, an interlinerofpolyesterfilm is incorporated in a roll of such foam sheet, one side of the film which lies adjacent the adhesive surface being provided with a release coating having release characteristics which are superior to those of a release coating which is provided on the other side of the film.

The polyester film, such as for example, a film of either of the polyethylene glycol terephthalate materials sold under Registered Trade Marks "Myler" and "Melinex" are generally between 0.019 mm and 0.250 mm in thickness, and preferably between 0.036 mm and 0.1 mm in thickness.

The release characteristics of the film coatings are determined by the following test method.

Tesa 155 tape, manufactured by Tesa Tapes Ltd., is laminated to a coated film at 70"C for two hours. The laminate is then equilibrated in an atmosphere of 50% relative humidity at 23"C and the force required to peel the tape from the film at 180"C per 25 mm width of tape is obtained using a tensometer at a cross-head speed of 1100 mm per minute.

In accordance with the invention, a force of between 0 and 20 gms preferably between 0 and 10 gms is to be regarded as most satisfactory for the film side in contact with the adhesive. For the other side of the film a force of 40 to 600 gms is most satisfactory, the more preferable range being 100 to 450 gms and the optimum value, 150 to 300 gms.

A wide variety of release coating compositions may be employed, for example solvent based silicone compositions for the adhesive contacting side, and chrome compositions for the other side of the film.

One preferred method of producing a roll accord ing to the invention will now be described with reference to the accompanying diagrammatic drawing.

As shown in the drawing a roll of release coated polyester interlining film 1 is fed through a paste coating head whereat p.v.c. paste is applied to the side of the film with the inferior release characteristics. The coated film then passes through an oven 3 to cause generation of a foam layer from the p.v.c.

paste. The exposed surface of the foam layer is then coated with pressure-sensitive adhesive composition at a second coating head 4 and the film is fed through a second oven 5 at which the adhesive is dried. The film with the adhesive coated foam layer is then wound onto a roll 6, and can subsequently be cut transversely to form reels of strip material if required.

Such a material has improved properties compared with the existing products since the interliner is more consistent in quality than paper, the film can be easily stripped when the adhesive coated foam is to be used without the film, without the film being torn or incompletely removed, and it can, if required, be temporarily replaced on the exposed foam surface as a protective coating after the foam strip or sheet has been attached to the final substrate.

Additionally, when the roll is cut to form strip reels, a clean cut edge is obtained on the interliner film.

1. A roll of polyvinyl chloride foam sheet or strip having a pressure-sensitive adhesive coating on one surface of the sheet or strip which is covered with an interlinerfilm of a polyester, the film being coated on each side with a release agent such that the release characteristics of the side adjacent the adhesive are superior to those of the other side of the film.

2. A roll of polyvinyl chloride foam sheet or strip according to claim 1, wherein the release characterisitics, as determined by the test method hereinbefore described, of the side of the film adjacent the adhesive are 0-20 gms.

3. A roll of polyvinyl chloride foam sheet or strip according to claim 2, wherein the said release characteristics are 0-10 gms.

4. A roll of polyvinyl chloride foam sheet or strip according to any of claims 1-3, wherein the release characteristics, as determined by the test method hereinbefore described, of the said other side of the film are 40-600 gms.

5. A roll of polyvinyl chloride foam sheet or strip according to claim 4, wherein the said release characteristics of the said other side of the film are 100-450 gms.

6. A roll of polyvinyl chloride foam sheet or strip according to claim 5, wherein the said release characteristics of the said other side of the film are 150-300 gms.

7. A roll of polyvinyl chloride foam sheet or strip according to any of claims 1-6, wherein the film thickness is 0.019 mm - 0.25 mm.

8. A roll of polyvinyl chloride foam sheet or strip according to claim 7, wherein the film thickness is 0.036-0.1 mm.

9. A roll or polyvinyl chloride foam sheet or strip according to any of claims 1-8, wherein the film is of a polyethylene glycol terephthalate composition.

10. A method of making a roll of polyvinyl chloride foam sheet according to any of the preceding claims comprising the steps of applying a coating of a foamable paste of polyvinyl chloride to a surface of a polyester film which has been coated on both sides with release agents so that the said surface has inferior release characteristics to that of the other film surface, treating the paste coating to form a layer of foam, coating the exposed surface of the foam layer with a pressure-sensitive adhesive, and winding the laminated structure thus formed into a roll.

11. A method according to claim 10, wherein, the roll is subsequently transversely cut to divide into a

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Adhesively coated polyvinyl chloride foam This invention relates to the manufacture of rolls of p.v.c. foam in strip or sheet form which is coated on one side with a pressure-sensitive adhesive. Such foam strips or sheets are commonly employed as a sealing material. At present it is common to employ an interliner of paper when sheet p.v.c. foam is wound into a roll to prevent adjacent coils adhering together and to prevent the foam from stretching in use. In accordance with the present invention, an interlinerofpolyesterfilm is incorporated in a roll of such foam sheet, one side of the film which lies adjacent the adhesive surface being provided with a release coating having release characteristics which are superior to those of a release coating which is provided on the other side of the film. The polyester film, such as for example, a film of either of the polyethylene glycol terephthalate materials sold under Registered Trade Marks "Myler" and "Melinex" are generally between 0.019 mm and 0.250 mm in thickness, and preferably between 0.036 mm and 0.1 mm in thickness. The release characteristics of the film coatings are determined by the following test method. Tesa 155 tape, manufactured by Tesa Tapes Ltd., is laminated to a coated film at 70"C for two hours. The laminate is then equilibrated in an atmosphere of 50% relative humidity at 23"C and the force required to peel the tape from the film at 180"C per 25 mm width of tape is obtained using a tensometer at a cross-head speed of 1100 mm per minute. In accordance with the invention, a force of between 0 and 20 gms preferably between 0 and 10 gms is to be regarded as most satisfactory for the film side in contact with the adhesive. For the other side of the film a force of 40 to 600 gms is most satisfactory, the more preferable range being 100 to 450 gms and the optimum value, 150 to 300 gms. A wide variety of release coating compositions may be employed, for example solvent based silicone compositions for the adhesive contacting side, and chrome compositions for the other side of the film. One preferred method of producing a roll accord ing to the invention will now be described with reference to the accompanying diagrammatic drawing. As shown in the drawing a roll of release coated polyester interlining film 1 is fed through a paste coating head whereat p.v.c. paste is applied to the side of the film with the inferior release characteristics. The coated film then passes through an oven 3 to cause generation of a foam layer from the p.v.c. paste. The exposed surface of the foam layer is then coated with pressure-sensitive adhesive composition at a second coating head 4 and the film is fed through a second oven 5 at which the adhesive is dried. The film with the adhesive coated foam layer is then wound onto a roll 6, and can subsequently be cut transversely to form reels of strip material if required. Such a material has improved properties compared with the existing products since the interliner is more consistent in quality than paper, the film can be easily stripped when the adhesive coated foam is to be used without the film, without the film being torn or incompletely removed, and it can, if required, be temporarily replaced on the exposed foam surface as a protective coating after the foam strip or sheet has been attached to the final substrate. Additionally, when the roll is cut to form strip reels, a clean cut edge is obtained on the interliner film. CLAIMS

11. A method according to claim 10, wherein, the roll is subsequently transversely cut to divide into a plurality of reels of strip material.

12. A method of making a roll of polyvinyl chloride foam sheet or strip having a pressuresensitive adhesive coating on one surface covered with an interlinerfilm substantially as hereinbefore described with reference to the accompanying drawings.