MXPA00005003A - A flushable release liner comprising a release coating on a water-sensitive film - Google Patents

Abstract

The present invention is directed to a flushable release liner. The flushable release liner is formed by applying a release coating onto at least one surface of a water-sensitive film. The flushable release liner maintains its integrity and strength when in use, but disperses when placed in contact with water, such as in a conventional sink or toilet. Moreover, the present invention is directed to water-dispersible products, including flushable products, which contain the flushable release liner.

Description

DM TORRO LIBBRAB -.- t AND DBSBCHABLB CQM DEBCARCH. OÜB CO-PRE-TOg tn RBCOBRIMIBM O -.IBBRABLE 8QBRB UBI PBLfCTI ... B-MBIBU _kl_? SU? FIELD OF THE INVENTION The present invention is directed to a releasable and disposable for discharge of water. The releasable and disposable liner with water discharge is formed by applying a release coating on at least one surface of a water-sensitive film. The disposable release liner with water discharge maintains its structural integrity and strength with it in use, but disperses when in contact with water, such as a toilet or conventional washing. In addition, the present invention is directed to the products, which include disposable products with water discharge and non-disposable with water discharge, which contains the disposable release liner with water discharge.

BACKGROUND OF THE INVENTION Disposable products have evolved modern lifestyle and are of great convenience for society. Such products are generally relatively inexpensive sanitary and quick and easy to use. The disposal of such products, however, is a concern, since the landfills are closed and the incineration contributes to the smoke and urban pollution. Consequently, there is an urgent need for disposable products that can be disposed of to go to landfills or go to incineration. An alternative of ideal disposal would be the use of municipal sewage treatment plants and private residential septic systems. The products suitable for disposal in drainage systems that can be discharged with water discharge in a conventional toilet are called "disposable with water discharge". The essential characteristic of disposable products with water discharge is that they must have sufficient strength for their intended use but still lose structural integrity in contact with water.

Numerous products for the consumer, previously unable to be discarded in a conventional retret, are currently disposable with water discharge. Such products include water soluble films, cleaning cloths, plug applicators, etc. However, many consumer products have remained n disposable with water discharge.

Another such product that has remained to be disposable with water discharge to date is the release liner. The release liners are used to temporarily cover a layer of adhesive before use in many personal care products. The release liner it provides protection to the adhesive layer against exposure to materials which could adversely affect the ability of the adhesive strip to adhere to the desired substrate, and provide protection against premature and unwanted adhesion to a substrate. Conventional release liners comprise a pap substrate coated with a release coating. The release coating is formulated to provide very little adhesion of the coated paper to any other substrate, particularly pressure sensitive hot melt adhesives, so that the release liner can be easily removed from the adhesive strip without disturbing the adhesive strip. Typically, these release coatings comprise a polymeric material comprising silicone. The release liners are used many items for personal care. Many sanitary towels have an adhesive strip on the back of the towel (the surface of the towel placed on the body contact surface) to fix the towel to an inner press and to hold the towel in place against the body. Before use, the adhesive strip is protected with a peelable release for. Once removed, removable and peelable liner can be discarded. Since the peelable release liners are typically silicone-coated paper, the release liners do not disperse at the boil consequently, disposal options are limited to depositing the release liner in a trash receptacle, a When the provision of conventional release liners in a toilet would be convenient for the consumer, such a deficit potentially creates locks in the toilet or in the domestic drain pipe.

What is required in the art is a disposable release sheet with water discharge, which can be discarded and then discarded in water in a conventional retret. Such a releasable and disposable liner with water discharge offers convenience to the consumer and does not cause problems such as blockages in the drainage transport process SYNTHESIS OF THE INVENTION The present invention is directed to a disposable release liner with water discharge comprising a thin release coating on at least one surface of a water sensitive film. The coated water sensitive film functions as conventional release papers currently used. Conventional release papers comprise a peelable coated paper, which covers an adhesive strip on a female sanitary napkin. Unlike the conventional release papers, the water-sensitive film coated to the present invention rapidly loses its integrity and strength when discarded in a conventional toilet. Without the support of the film sensitive to water, thin release coating, it will quickly break the force of waste with water discharge The structure with two layers of the release liner with water discharge offers the operation of a paper-based release liner with additional option of waste a toilet and a potentially lower cost.

The present invention is directed to a method of preparing a disposable release sheet with water discharge. The method comprises coating a thin layer of polymer having release characteristics on a base film and wherein the base film comprises a polymer sensitive to water When dried, the two-layer laminates exhibit mechanical characteristics comparable to a conventional coated paper liner. The base film itself can be manufactured taking into consideration variables such as film thickness, molecular weight and mixing additives such as to control the functionality of the plastic film. The polymeric coating controls the characteristics of the release of the film. plastic. The coating is formulated to provide very little adhesion to many substrates, particularly pressure sensitive hot melt adhesives, so that the coating can be easily removed from an adhesive strip without disturbing the adhesive strip, even when it has a high adhesion to the water sensitive substrate. . L coater formula ensures that the polymer film of do The layers are peeled on the surface of the release coating, not on the interconnection between the coating and the water sensitive base film.

The present invention is directed to articul containing the disposable release liner with water discharge. Specifically, the disposable discharge or water discharge liners of the present invention are useful in connection with a variety of products and especially absorbent products such as sanitary napkins, pantiliners, diapers, bandages and the like. Although the release liner of the present invention finds a particular "u" in the above-mentioned products, the concept of releasable and disposable liner with water discharge has potency for any other application that requires a release material.

The present invention provides a mechanism for eliminating the disposal problems associated with various products for the consumer. A detailed non-limiting description of the invention and examples of the specific incorporations is provided below.

DETAILED DESCRIPTION OF THE INVENTION The present invention is directed to a releasable and disposable water discharge comprising thin release coating on at least one surface of a water sensitive film. The coated water sensitive film works like the conventional release papers currently used. Nevertheless, unlike conventional release papers, the coated water sensitive film of the present invention is "disposable c water discharge". As used herein, the term "disposable c water discharge" describes a product which rapidly loses integrity and resistance when discarded in a conventional wash toilet. The two-layer laminate water disposable disposable feature of the present invention comes from the water sensitivity of the base film and the low strength of the thin release coating. When submerged in water, the uncoated side of the bas film easily becomes wet and weak. The water sensitive film quickly loses integrity and resistance when exposed to water. When the substrate layer rapidly loses integrida and resistance when exposed to water. When the substrate layer loses its mechanical integrity, the release coating in which it is thin and mechanically weak, is easily dispersed under the force of discharging with water discharge from a toilet or the force of water in a sink.

The two-layer laminate of the present invention is prepared by any process wherein a thin layer of the polymer having release characteristics and uniformly and continuously coated on at least one surface of a water sensitive film, such as a dioxide film. of polyethylene (PEO). Suitable coating processes include, but are not limited to co-extrusion coating, basecoat and hot-melt coating. Suitable extrusion coating techniques include, but are not limited to, the curtain extrusion coating and the co-extrusion of the coating of the water sensitive film. Suitable solvent base coating techniques include, but are not limited to, spray coating. Hot-melt coating techniques include, but are not limited to, co-channel coating, spray coating and photo etched coating. Desirably, the coating process is either a hot melt groove coating process or an extrusion coating process. At least a part of the surface area of the water-sensitive film is left uncoated so that the two-layer laminate remains if it is disposable with water discharge. A coating process is described below.

The molten "release polymer" is delivered from a melt tank through a connected hose a slot matrix. As used herein, the term "release polymer" describes a polymer which possesses release characteristics in the coating process. The melted polymer is uniformly applied directly onto the film sensitive to water or alternatively onto a carrier substrate and is subsequently transferred to the water-sensitive film. The line speeds may vary depending on the "open time" of the release polymer. As used herein, the "open time" of a polymer refers to the amount of a polymer required for the polymer to lose its tackiness.

In a transfer coating process the coated carrier substrate is further moved through the process and brought into contact with the water sensitive film which is suitably aligned with the coated carrier substrate. The coating is transferred from the carrier substrate to the water sensitive film under pressure by passing the carrier substrate in the film through a pressure point roller. In practice, the optimum coating thickness is achieved by adjusting the processing factors, which include, but are not limited to, the release polymer, the coating temperature, the resin flow rate, the line speed and the flow rate. pressure applied to the pressure point roller.

In any direct coating process or transfer coating process, the adhesion of the release coating to the film sensitive to water must be greater than the adhesion of the coating to the grating (direct coating) or to the sustrat carrier (coating). with transfer). The lesson of release polymer must take into consideration the desired release characteristics and adhesion properties of the release polymer. The release polymer must have good adhesion to the releasable water sensitive substrate suitable for use in the present invention includes any processable polymer with an appropriate melt rheology, release characteristics and adhesion properties for application by the hot melt coating process above. described. The polymers described above include, but are not limited to, polyolefin, fluoropolymers and silicones.

One or more of the release polymers mentioned above can be combined to form the coating of the water sensitive film. In addition, the release polymer may contain one or more of the following additives including, but not limited to compatibilizers, processing aids, plasticizers, binders, debonders, slip agents and antimicrobial agents, as agents of manufacturing or as modifiers depending on the specific properties desired in the coating and in the final product. The coating should be formulated to provide low adhesion to a variety of substrate, particularly pressure-sensitive hot-melt adhesives so that the coating can be easily removed from an adhesive strip without disturbing the adhesive strip, while still having a high adhesion to the sensitive substrate. the water. The coating formulations ensure that the two-layer polymer film is peeled off on the release coating surface, not on the interlayer and coating and the water-sensitive base film.

Desirably, the release polymer is a polyalphaolefin having a melt viscosity of about 400 to about 8,000 centipoise at about 190 ° C. Suitable polymers include, but are not limited to, amorphous propylene-ethylene copolymers. Particularly suitable polymers are manufactured by U.S. Rexene Compan under the brand REXTAC *. A REXTAC * RTE32 resin is particularly suitable for the present invention. In a further embodiment one or more REXTAC resins mixed with the highly branched, low molecular weight polyolefin to reduce tackiness of the hydrophobic polymer coating Desirably, the highly branched polyolefin has an average molecular weight of number (M.) of less than about of 2800 A particularly suitable low molecular weight, a highly branched polyolefi VYBAR »253 (M. * 520) is manufactured by Petrolite Corporation. The mixtures of REXTAC »and VYBAR» 25 provide good results as releasable coating materials. Desirably, the proportion of the REXTAC »VYBAR» 253 resin is from about 100/0 weight / weight to about 70/30 weight / weight. More desirably, the resin ratio REXTAC * to VYBAR * 253 is from about 98/2 w / w about 75/25 w / w. More desirably, the ratio d of the REXTAC »to VYBAR» 253 resin is from about 95 / weight / weight to about 80/20 weight / weight. Particularly useful mixtures are RTE32 / VYBAR »253 (95/5 weight / weight) RTE32 / VYBAR» 253 (80/20 weight / weight).

The thickness of the release coating can vary greatly from the final use of the two-layer laminate and / or the products containing the two-layer laminate. The thickness of the film should be minimized when possible. To reduce the cost of product and to reduce the mechanical resistance of coating, particularly for disposable products with water discharge, so that the coating will disperse due to the forces of discharging with discharge of the water on the coating. Desirably, the coating thickness d will be less than about 25.4 micrometers. More desirably, the thickness of the release coating will be less than about 15.2 micrometers. More desirably, e Thickness of release coating will be less than about 5.1 micrometers. However, the coating must be sufficiently thick to provide a continuous coating along the surface of the film.

The carrier substrate in the above described process can be any substrate which can transfer the release coating to the water sensitive film. Suitable carrier substrates include little or no adhesion to the release coating relative to the adhesion between the water sensitive film and the release coating. Suitable carrier substrates include but are not limited to release paper, release films, and release-coated substrates, such as webs and / or webs. Desirably, the carrier substrate is a releasable paper. More desirably, the carrier substrate is a high release AKROSIL paper. " The water sensitive films for use in the present invention include any water sensitive film capable of supporting the above described coating process. As used herein, the phrase "water-sensitive film" describes films which lose integrity with time when in the presence of water, and are not limited to water-soluble films and water-dispersible films. Suitable water sensitive films have a sufficient strength and adhesion properties to be used in the processes described above. Suitable polymers include but are not limited to polyalkylene oxides such as d-polyethylene oxide (PEO) and copolymers of ethylene oxide and / or d-propylene oxide, polymethacrylic acid, copolymers of polymethacrylic acid, polyvinyl alcohol, poly (2-ethyl oxazoline) ) polyvinyl methyl ether, copolymers of polyvinyl pyrrolidone / vini acetate, methyl cellulose, ethyl cellulose, hydroxypropyl cellulose hydroxypropyl methyl cellulose, ethyl hydroxyethyl cellulose, methyl ether starch, poly (n-isopropyl acrylamide), poly N-vini caprolactam, polyvinyl extil oxazolidone, poly (2-isopropyl-2-oxazoline) and poly (2,4-dimethyl-6-triazinyl ethylene).

The water-sensitive film of the present invention can be made completely of a water-sensitive polymeric material or can contain water-insoluble as well as water-sensitive materials as long as the film is dissolved and dispersed in water, such as in a conventional toilet Additionally, water sensitive films can also be made by combining the various different types of water sensitive film materials. In some embodiments, it may be desirable to employ one or more additives in the water-sensitive film material including but not limited to compatibilizers, process aids, plasticizers, binders, debonders, agents of slipping, and to the agent antimicrobials, as manufacturing agents or as modifier depending on the specific properties desired in the film or in the final product.

Desirably, the water sensitive film of the present invention comprises a polyalkylene oxide film or a polyvinyl alcohol film. Desirably, the water-sensitive film of the present invention, the water-sensitive film of the present invention comprises a polyethylene oxide film, a polyethylene oxide / polypropylene oxide copolymer film or a polyvinyl alcohol film. More desirably, the water-sensitive film of the present invention comprises a polyethylene oxide film or a polyvinyl alcohol film. The polyethylene oxide film is the most desirable film for the transfer coating process while the polyvinyl alcohol film It is the most desirable film for the direct coating process.

The thickness of the water-sensitive film can vary depending on the final use of the two-layer laminate and / or the products containing the two-layer laminate. The film thickness should be minimized when possible to reduce the cost of the product and to reduce the time needed for the film to disperse, especially in the case of disposable products with water discharge. Desirably, the Thickness of water-sensitive film will be less than around 50.8 micrometers. More desirably, the thickness of the water sensitive film will be from about 2.5 micrometers around 35.6 micrometers. More desirably, the thickness of the water-sensitive film will be from about 2. micrometers to about 12.7 micrometers.

With the release characteristics and the adhesion properties, the two-layer laminate of the present invention finds applicability in a variety of articles. Specifically, the disposable water-release release liners of the present invention are useful in connection with a variety of products, and especially the absorbent products such as sanitary napkins, disposable absorbent articles, diapers, bandages and the like Even when the release liner of the present invention finds particular use in the above mentioned products the concept of a releasable liner and disposable with water discharge of the above mentioned products, the concept of a releasable and disposable forr with water discharge has a power for any other applications where a release liner is used.

Those skilled in the art will readily understand that the two-layer laminates of the present invention can be advantageously employed in the preparation of an amplifier. variety of products designed to contain at least one component that has a release surface. Such products may comprise only the coated water-sensitive film or may comprise a coated water-sensitive film in combination with one or more additional layers such as coatings, films, fabrics, etc. While the water-sensitive film is coated with the present invention is particularly suitable for release liners, the coated water-sensitive film of the present invention can be advantageously employed in the preparation of a wide variety of consumer products other than those of the consumer. the release linings.

The present invention is further illustrated by the following examples, which are not considered in any way as imposing limitations on the scope thereof. On the contrary, it should be clearly understood that several other additions, modifications and equivalents thereof should be sought, which, after reading the description given herein, may suggest themselves to those skilled in the art without departing from the spirit of the present invention and / or the appended claims.

EXAMPLE 1 A release liner was made by the following process. A release coating comprising a mixture of 30% by weight of paraffin wax from the molecular step under VYBAR »253 (from Petrolite Polymers), and a polyalphaolefin coating class REXTACß RTE32 (US Rexane Company), coated on a base film dies oxide polyethylene (PEO). The mixture was slit coated on a release paper and subsequently transferred to the polyethylene oxide film under the following conditions: tank temperature 315 ° F; grid temperature 324 * F; hose temperature 340ßF; die temperature 330 * F; and speed dß lin 24 feet per minute. The base film of the polyethylene oxide of approximately 30.5 micrometers thick was prepared as a composite resin at Planet Polymer (San Diego, California). The mixture was applied to the polyethylene oxide film to produce a final coating thickness of about 20 micrometers.

The base Rexene resin itself showed good adhesion to the polyethylene oxide substrate, even though it was slightly sticky. • When mixed with the VYBAR additive, the adhesion to the polyethylene oxide substrate was improved while the tackiness of the coating was effectively suppressed.

Since the Rexene resins themselves are used as a base component in many adhesive formulas, the resulting two-layer laminate was tested for adhesion to the Rexenß resins. The mixture showed no adhesion to a non-mixed RTE32 coating. The mixture also showed no adhesion to other Raxena coatings, such as the REXTAC RT2330 coatings.

The two-layer laminate easily broke when held under a gentle flow of water from a tap water in a sink. The resulting two-layer laminate exhibited the key features required in a disposable release sheet with water discharge.

Claims (28)

RlIYI »PICICIvHII

1. A disposable laminate with discharge of ag having releasing characteristics, said laminate comprises: a film sensitive to water; Y a continuous release coating of polymeric material on a surface of the water-sensitive film, wherein the coating adheres to the water-sensitive film and provides release to laminate characteristics.

2. The disposable laminate with water discharge as claimed in clause 1, characterized in that the water-sensitive film comprises polyethylene oxide copolymers of polyethylene oxide / polypropylene oxide, polymethacrylic acid, copolymers of polymethacrylic acid, polyvinyl alcohol, poly (2-ethyl oxazoline), polyvinyl methyl ether copolymers of polyvinyl pyrrolidone / vinyl acetate, methyl cellulose, ethyl cellulose, hydroxypropyl cellulose, hydroxypropyl methyl cellulose, ethyl hydroxy ethyl cellulose, methyl ether starch, poly (n-isopropyl acrylamide), poly N-vinyl caprolactam polyvinyl methyl oxazolidone, poly (2-isopropyl-2-oxazoline) poly (2,4-dimethyl-6-triazinyl ethylene) or vina combination thereof.

3. The disposable laminate with water discharge as claimed in clause 2, characterized in that the water sensitive film comprises polyethylene oxide ethylene oxide / propylene oxide, polyvinyl alcohol or a combination thereof.

4. The disposable laminate with water discharge as claimed in clause 1, characterized in that the polymeric material comprises a polyolefin, fluoropolymer, silicone or a combination thereof.

5. The disposable laminate with water discharge as claimed in clause 4, characterized in that the polymeric material comprises a polyalphaolefin having a melt viscosity of from about 400 to about 800 centipoise at 190 ° C.

6. The disposable laminate with water discharge as claimed in clause 5, characterized in that the coating further comprises at least one highly branched polyolefin of low molecular weight.

7. The disposable laminate with ag discharge as claimed in clause 6, characterized in that the at least one highly branched polyolefin of low molecular weight has an average molecular weight d minus number around 2800 d.

8. The disposable laminate with discharge dß ag as claimed in clause 3, characterized in that the water-sensitive film comprises polyethylene oxide.

9. The disposable laminate with discharge dß agu as claimed in clause 8, characterized in that the disposable laminate with water discharge is a releasable forr.

10. The disposable laminate with water discharge as claimed in clause 1, characterized in that the water-sensitive film has a thickness of less than about 50.8 micrometers and the coating has a thickness of less than about 30.5 micrometers.

11. The releasable and disposable liner with water discharge comprising: a film sensitive to water; Y a release coating in continuous polymeric material on a surface of the water sensitive film, wherein the coating adheres to the water sensitive film and provides liner release characteristics.

12. The releasable and disposable liner with water discharge as claimed in clause 11, characterized in that the water-sensitive film comprises polyethylene oxide, polyethylene oxide / polypropylene oxide copolymers, polymethacrylic acid, polymethacrylic acid copolymers, polyvinyl alcohol, poly (2-ethyl-oxazoline) polyvinyl methyl ether, copolymers of polyvinyl pyrrolidone / vini acetate, methyl cellulose, ethyl cellulose, hydroxypropyl cellulose hydroxypropyl methyl cellulose, ethyl hydroxy ethyl cellulose, methyl ether starch, poly (n-isopropyl acrylamide), poly N-vini caprolactam, polyvinyl methyl oxazolidone, poly (2-isopropyl-2 oxazoline), poly (2,4-dimethyl-6-triazinyl ethylene) or a combination thereof.

13. The releasable and disposable liner with water discharge as claimed in clause 12, characterized in that the water sensitive film comprises polyethylene oxide, ethylene oxide / propylene oxide, polyvinyl alcohol or a combination thereof.

14. The releasable and disposable liner with water discharge as claimed in clause 11, characterized in that the polymeric material comprises a polyolphine, a fluoropolymer, a silicone or a combination thereof.

15. The releasable and disposable liner with water discharge as claimed in clause 14, characterized in that the polymeric material comprises a polyalphaolefin having a melt viscosity of from about 400 to about 8,000 centipoise at 190 * C.

16. The releasable and disposable liner with water discharge as claimed in clause 15, characterized in that the coating further comprises at least one highly branched polyolefin of low molecular weight.

17. The releasable and disposable liner with water discharge as claimed in clause 16, characterized in that the at least one highly branched polyolefin of low molecular weight has a number average molecular weight of less than about 2800.

18. The releasable and disposable liner with water discharge as claimed in clause 13, characterized in that the water-sensitive film comprises polyethylene oxide.

19. The release liner and desßchablß with water drift as claimed in clause 11, characterized in that the water-sensitive film has a thickness d d less than about 50.8 micrometers and the coating has a thickness of less than about d.sub.30.5 micrometers.

20. A product that includes: a disposable laminate with water discharge wherein the disposable water laminate with d &bt discharge comprises a water-sensitive film and a continuous releasable coating of polymeric material exposed on a surface of the water sensitive film wherein the coating adheres to the Water sensitive film provides release characteristics to the laminate; Y at least one additional layer adhered to continuous release coating of laminate.

21. The product as claimed in clause 20, characterized in that said product comprises a disposable absorbent article such as a panty liner, an incontinence garment and a bandage or diaper.

22. The product as claimed in clause 21, characterized in that said product comprises a disposable absorbent article, said disposable article further comprises a liquid-permeable upper sheet and a liquid-permeable lower leaf.

23. A method for manufacturing a disposable laminate with water discharge having release characteristics, said method comprises: coating a continuous release layer of polymeric material on a water sensitive film surface, wherein the release layer adheres to the water sensitive film and provides release to laminate characteristics.

24. The product as claimed in clause 20, characterized in that the polymeric material comprises at least one polyolefin having at least one molten viscosity of from about 400 to about 800 centipoise at 190 ° C and at least one polyolefin ramified altament of low molecular weight.

25. The method as claimed in clause 24, characterized in that at least one highly branched polyolefin of low molecular weight has an average molecular weight of the number of less than 2800.

26. The method as claimed in clause 23, characterized in that the water-sensitive film is a film material comprising polyethylene oxide copolymers of polystyrene oxide / polypropylene oxide, polymethacrylic acid, copolymers of polymethacrylic acid, polyvinyl alcohol, poly (2-ethyl oxazoline), polyvinyl methyl ether copolymers of polyvinyl pyrrolidone / vinyl acetate, methyl cellulose, ethyl cellulose, hydroxypropyl cellulose, hydroxypropyl methyl cellulose, ethyl hydroxy ethyl cellulose, methyl ether starch, poly (n-isopropyl acrylamide), poly N-vinyl caprolactam, polyvinyl methyl oxazolidone, poly (2-ißopropy1-2-oxazoline), poly (2,4-dimethyl-6-triazinyl ethylene) or vine combination thereof.

27. The method as claimed in clause 26, characterized in that the polymeric material and film material are co-extruded to form a disposable laminate with water discharge.

28. The method as claimed in clause 23, characterized in that the laminate is formed by the extrusion coating or hot melt d slot coating. The present invention is directed to a releasable and disposable liner with water discharge. The releasable and disposable liner with water discharge is formed by applying a release coating on at least one surface of a water-sensitive film. The disposable release forceps with water discharge maintains its integrity and strength when in use, but disperses when placed in contact with water, such as in a conventional toilet or washbasin. In addition, the present invention is directed to water dispersible products including disposable products with water discharge, which contain the disposable release liner with water discharge.