MXPA00012369A - Water-modifiable flushable polyolefin-containing film and article made therefrom - Google Patents

Abstract

The invention provides a water degradable modified polyolefin-modified poly(ethylene oxide)-containing film having greater than about 55 weight percent of a modified polyolefin and less than about 45 weight percent of a modified poly(ethylene oxide). The polyolefin and poly(ethylene oxide) polymers are modified by having grafted thereto from about 0.1 weight percent to about 30 weight percent of a monomer selected from 2-hydroxyethyl methacrylate or polyethylene glycol ethyl ether methacrylate. The modified polyolefin-modified poly(ethylene oxide)-containing film of the invention, when immersed in water for about 30 seconds, loses at least 10%in two or more of the tensile properties:percent strain-to-break, peak stress, energy-to-break and modulus when compared to the dry or pre-immersion values. Also provided are flushable personal care articles such as infantdiapers, feminine hygiene napkins, and adult incontinence garments having a backing or barrier layer comprising a water degradable modified polyolefin-modified poly(ethylene oxide)-containing film of the invention.

Description

FILM CONTAINING DISPOSABLE POLYOLEPHINE WITH DISCHARGE WATER AND MODIFIED IN WATER AND ARTICLE MADE WITH THE SAME Field of the Invention The present invention relates to a film containing polyolefin degradable in water. More particularly, the present invention relates to a film containing polyolefin degradable in water having more than about 55 percent by weight of a modified polyolefin and less than about 45 percent by weight of a poly (ethylene oxide) modified.

Background of the Invention Personal care products, such as infant diapers, sanitary napkins, adult incontinence garments, and the like are generally constructed of a number of different components and materiels. Such articles typically have some part, usually the bottom layer, the liner, the barrier or the separator constructed of a liquid repellent film material. This repellent material is suitably constructed to minimize or prevent the exudation of the liquid absorbed from the article and to obtain a greater utilization of the absorbent capacity of the product. The liquid repellent film commonly used includes plastic materials such as polyethylene films and the like.

Even though such products are relatively cheap, sanitary and easy to use, the disposal of a soiled product is not without problems. With a greater interest being placed on the protection of the environment, there is a need to develop materials that are more compatible with existing and developing waste disposal technologies while still delivering an operation that consumers expect. An ideal disposal alternative would be the use of municipal sewer treatment and private residential sewer systems. The products suitable for disposal in sewage systems can be discarded by discharging water into a convenient toilet and are termed "disposable with water discharge".

Even when the discharge of water from such articles would be convenient, the liquid repellent material which normally does not disintegrate in the water tends to clog the toilets and sewer pipes. It is therefore necessary, even if undesirable, to separate the barrier film material from the absorbent article prior to disposal with water discharge.

In addition to the article itself, typically the packaging in which the disposable article is distributed is also made of a water resistant material. Water resistance is necessary to avoid packing degradation due to environmental conditions and to protect the disposable items contained therein. Even when this packaging can; to be safely stored with other waste for commercial waste, and especially in the case of individual packages of products, it is more convenient to discard the package in the toilet with the disposable item discarded. However, in cases where such a package is composed of a water resistant material, it typically results in the clogging of the pipes for the toilet.

Desirably, a commercial product degradable in water or disposable with water discharge must respond relatively to water and be transportable in the sewer system. Commercially available water-soluble polymers, such as poly (polyethylene oxide) (PEO), poly (vinyl alcohol) (PVOH), acrylamide polymers, acrylic acid-based polymers, and cellulose derivatives, possess the characteristics desired for waste with water discharge, such as water solubility and / or dispersibility in water. However, due to their degradability in use and their degradation in storage, these materials function poorly as components in personal care products. Other disadvantages are that these polymers are difficult to process and are essentially more expensive than polyolefins.

The requirements for a functional and disposable product with water discharge provide a substantial challenge to find suitable materials with the desired properties. In an attempt to overcome the problem of discharging water from a water-resistant film, the prior art has modified the water-resistant polymer. One of the most useful ways to modify polymers involves mixing them with other polymers of different structures and properties.

Polymer blends of polyolefins and poly (ethylene oxide) have been shown to be modifiable in water at expected low percent weight percent polyolefins. Such mixtures are anticipated to be disposable with water discharge when they are exposed to water in a toilet but do not possess the dry mechanical properties required for operation in use. In addition, the high content of poly (ethylene oxide) makes these materials prohibitively expensive to use in a disposable personal hygiene article such as a sanitary napkin, a diaper and the like. Polymer blends of polyolefins and poly (ethylene oxide) containing more than about 45 percent by weight of the polyolefin are generally water resistant and not modifiable in water. In view of the problems of the prior art, it remains highly desirable to provide a modifiable film in water having a substantial part thereof composed of a polyolefin. More desirably, the water modifiable or water degradable film should have more than about 55 weight percent of a polyolefin. When it is dry, the film must have the mechanical properties necessary for its functionality. When wet, the film must lose at least a part of its mechanical properties which will make the film disposable with water discharge and transportable in the sewer system. Such films will be used to make disposable bairrera films with water discharge for personal care products.

It is therefore an object of the invention to provide a polyolefin-containing film that is modifiable in water or degradable in water which contains higher levels of polyolefin content. More specifically, it is an object of the invention to provide a polyolefin-containing film having more than about 55 percent by weight of a polyolefin and less than about 45 percent by weight of poly (ethylene oxide) that It is modifiable in water or degradable in water.

Synthesis of the Invention In its main embodiment, the present invention provides a film containing polyolefin degradable in water comprising more than about 55 percent by weight of a modified polyolefin and less than about 45 percent by weight of a poly (ethylene oxide) modified. The film of the invention has a loss of at least 10% in two or more tension properties selected from percent of stress at break, peak stress, energy-to-peak and modulus after being immersed in water for 30 seconds .

In an alternate embodiment, the present invention provides a disposable water-based personal care article having a backing or barrier layer of: a film comprising more than about 55 weight percent of a modified polyolefin and less than about 45 weight percent. percent by weight of modified poly (ethylene oxide). The film has a loss of at least 10% in two more tension properties selected from percent of stress at break, peak stress, energy at break and modulus after being immersed in water for 30 seconds.

Detailed description of the invention As used herein "modifiable in water" or "degradable in water" means that a film of four thousandths of an inch thick (one thousandth equal to 0.001 of an inch or 0.025 mm), when immersed in water for 30 seconds, will be modified by more than 10% in two or more of the following tensile properties: percent of breaking stress, peak stress, breaking energy and modulus.

To determine the degree of modification with water or degradation in water, the "wet" values after c.e. immersion in water are compared with the presumed or "dry" film values.

The term "personal care product" or "personal care item" means typical items such as infant diapers, sanitary napkins, adult incontinence garments, and the like.

By the term "backing layer" or "barrier layer" it is required to say that component of an infant diaper, of a sanitary napkin, of an adult incontinence garment or the like which is worn during normal use. further away from the body of the user and which serves to minimum h.acer or prevent exudation of absorbed liquid.

Although the present invention is described with reference to a water-modifiable film and, in particular, to personal care articles having a barrier layer, a liner or a barrier layer comprising such films, one skilled in the art will understand that the composition of the invention can be used to make other thermoplastic articles that can be extruded or injection molded in which the desired property of water degradability is necessary, such as packaging materials and the like.

The water-degradable or water-modifiable film comprises more than about 55 weight percent of a modified polyolefin and less than about 45 weight percent of modified poly (ethylene oxide). Desirably, the water-modifiable film comprises from about 55 percent by weight to about 85 percent by weight of a modified polyolefin and from about 45 percent by weight to about 15 percent by weight of poly ( modified ethylene oxide). More desirably, the film modifiable with water comprises from about 65 weight percent to about 85 weight percent of a modified fine polyole and from about 35 weight percent to about 15 weight percent of a modified poly (ethylene oxide). Polyolefins useful in the practice of this invention include ethylene or polypropylene homopolymers or copolymers and are essentially linear in structure. As used herein, the term "saturated" refers to polymers: which are completely saturated, but also includes: polymers containing up to about 5% unsaturation. Ethylene homopolymers include those prepared under either low pressure, for example, low density or linear low density polyethylene, or high pressure, for example, low density or branched polyethylene. High density polyethylenes are generally characterized by a density that is almost equal to or greater than 0.94 grams per cubic centimeter (g / cc). Generally, the high density polyethylenes useful as the base resin in the present invention have a density ranging from about 0.94 g / cc to about 0.97 g / cc. Polyethylenes can have a melt index, as measured at 2.16 kilograms and 1900C, ranging from about 0.005 decigrams per minute (dg / min) to 100 dg / min. Desirably, the polyethylene has a melt index of 0.01 dg / min to about 50 dg / min and more desirably from 0.05 dg / min to about 25 dg / min.

Alternatively, the polyethylene blends can be used as the base resin for producing the graft copolymer compositions, and such blends can have a melt index greater than 0.005 dg / min at about 100 dg / min.

The low density polyethylene has a density of less than about 0.94 g / cc and is usually in the range of 0.91 g / cc to about 0.93 g / cc. The low density polyethylene has a melt index ranging from about 0.05 dg / min to about 100 dg / min and desirably from 0.05 dg / min to about 20 dg / min. The ultra low density polyethylene can be used in accordance with the present invention. Generally, ultra-low density polyethylene has a density of less than 0.90 g / cc.

Generally, polypropylene has a semicrystalline structure having a molecular weight of about 40,000 or more, a density of about 0.90 g / cc, a melting point of 168 to 171 ° C for isotactic polypropylene and a tensile strength. of 5000 pounds per square inch. Polypropylene can also have other tacticities including syndiotactic and atactic.

The aforementioned polyolefins can also be manufactured by the use of well-known multi-site Ziegler-Natta catalysts or by the use of the most recent single site metallocene catalysts. The metallocene-catalyzed polyolefins have better controlled polymer microstructures than the polyolefins made using the Ziegler-Natta catalysts, including the narrowest molecular weight distribution, a well-controlled chemical composition distribution, a co-monomer sequence length distribution, and a stereoregularity. Metallocene catalysts are known to polymerize propylene in atactic, isotactic, syndiotactic, isotactic-atactic stereoblock copolymer.

The ethylene copolymers which may be useful in the present invention may include copolymers of ethylene with one or more polymerizable unsaturated monomers. Examples of such copolymers include, but are not limited to copolymers of ethylene and alpha olefins (such as propylene, butene, hexene or octene) including linear low density polyethylene, ethylene copolymers and vinyl ethers of linear carboxylic acids or branched having 1-24 carbon atoms such as ethylene-vinyl acetc.to copolymers and ethylene copolymers and acrylic or methacrylic esters of linear, branched or cyclic alkanols having 1-28 carbon atoms. Examples of the latter copolymers include ethylene-alkyl (meth) acrylate 5 copolymers, such as ethylene-methyl acrylate copolymers.

The poly (ethylene oxide) polymers suitable for making the films of this invention are available: Union Carbide Corporation, of Danbury, CT under the trademark POLYOX®. Typically, the poly (ethylene oxide) and dry powder of free flowing and white having a crystalline melting point in the order of about 65 ° C, above which the poly (ethylene oxide) resin becomes thermoplastic and can be formed by molding, extrusion and other methods known in the art.

In the main embodiment of the invention, a film modifiable with water comprises more than about 55 percent by weight of a modified polyolefin and less than about 45 percent by weight of modified poly (ethylene oxide). Preferably, the water-modifiable film comprises from about 55 percent by weight to about 85 percent by weight of a modified polyolefin and from about 45 percent by weight to about 15 percent by weight of poly ( modified ethylene oxide). More desirably, the film modifiable with water comprises from about 65 weight percent to about 85 weight percent of a modified polyolefin and from about 35 weight percent to about 15 weight percent poly (ethylene oxide) modified. The poly (ethylene oxide) polymers suitable for this embodiment of the present invention can have a molecular weight ranging from 100,000 to 8,000,000. The polyolefin and the poly (ethylene oxide) are modified by grafting them from about 0.1 percent by weight to about 30 percent by weight, based on the weight of the polyolefin and the poly (oxide). ethylene) of the monomer. Desirably, the polyolefin and the poly (ethylene oxide) have a total of from about 1 weight percent to about 20 weight percent of the monomer grafted thereto. More desirably, the polyolefin and the poly (ethylene oxide) have a total of from about 1 weight percent to about 10 weight percent of the monomer grafted thereto. The water-modifiable film of the present invention can be made as described in the co-pending United States of America patent application having serial number of the United States of America 08 / 777,226 filed on December 31, 1996 and entitled "Polyolefin and Poly (ethylene oxide) Mixtures and Process for Making Mixtures", the description of which is incorporated herein by reference.

Generally, the film is made by mixing with melted the desired weight ratios of: a mixture of the polyolefin, the poly (ethylene oxide), the monomer and the free radical initiator in an extruder and at a reaction temperature in where the polyolefin and poly (ethylene oxide) are converted to a melted state. Preferably, the polyolefin and the poly (ethylene oxide) are added at the beginning of the extruder. After melting, the monomer is added to the melted mixture. In addition, downstream of the extruder biconcil, the free radical initiator is supplied to the melted mixture.

Free radical initiators which can be used to graft the monomer into the polyolefin include acyl peroxides such as benzoyl peroxide; dialkyl; diaryl; or aralkyl peroxides such as di-t-butyl peroxide; dicumyl peroxide; cumyl butyl peroxide; 1, 1-di-t-peroxide butyl-3,5,5,5-trimethylcyclohexane; 2, 5-dimethyloxy-2,5-di (t-butyroxy) hexane, 2,5-dimethyl-2,5-bis- (t-butylperoxy) hexin-3 and bis- (pt-butyl peroxyisopropylbenzene) :do not); peroxyesters such as t-butyl peroxypivalate; t-butyl peroctoate; t-butyl perbenzoate; 2,5-dimethylhexyl-2,5-di (perbenzoate); t-butyl di- (perftalate); dialkyl peroxymonocarbonates and peroxydicarbonates; hydroperoxides such as t-butyl hydroperoxide, p-methane hydroperoxide; pentane hydroperoxide and eumeno hydroperoxide and ketone peroxides such as peroxide cyclohexanone and methyl ethyl ketone peroxide. Azo compounds such as azo-bis-isobutyronitrile can also be used.

When the polyolefin is modified together with the poly (ethylene oxide), the amount of the free radical initiator added to the extruder must be an amount sufficient to graft from about 1 percent to about 100 percent of the monomer in the polymer , for example, polyolefin or polyolefin and poly (ethylene oxide). This can vary from about 0.1 percent by weight to about 2 percent by weight of the initiator.

Preferably, the amount of initiator added to the extruder ranges from about 0.1 percent by weight to about 1 percent by weight where all those ranges are based on the amount of monomer added to the melted mixture.

The water-modifiable polyolefin films of the present invention will, when submerged in water for about 30 seconds, have at least two of the tensile properties modified: the tensile stress at break, the peak stress, the breaking energy and the module by- more than about 10%. Desirably, at least two of the tensile properties will be reduced by more than about 25%.

More desirably, at least two of the tensile properties will be reduced by from about 25% to about 98%, and even more desirably at least two of the tensile properties: tensile stress at break, peak stress , breaking energy and modulus will be reduced by from about 30% to around 80%. The values to determine the extension of the tression property or the modification properties are relative to the dry condition, for example, the value before pre-immersion for that measured property.

The present invention is illustrated in more detail by the specific examples presented below. It will be understood that these examples are illustrative embodiments and are not intended to be limiting of the invention, but rather are broadly considered within the scope and content of the appended claims.

Comparative Example A A mixture of 60/40 percent by weight of low density polyethylene (PE) having a melt index of 1.9 decigrams per minute (dg / min) and a density of 0.922 grams per cubic centimeter (g / cc) ( Dow 5031, available from Dow Chemical Company, Midland, Michigan) and polyethylene oxide (PEO) having a molecular weight of 200,000 g / mol (POLYOX® WSRN-80 available from Union Carbide Corporation, from Danbury, Connecticut) was fed to a Haake twin screw counter extruder at a rate of 5 pounds / hour (2.27 kilograms / hour). The extruder had a length of 300 millimeters. Each conical screw had a diameter of 30 millimeters in the supply port and a diameter of 20 millimeters in the matrix. The extruder had four heating zones set at 170oc, 180oC, 180oC and 190oC. The screw speed of the extruder was 150 revolutions per minute.

The processing film of all blends was carried out using a Haake extruder twin screw extruder as described above with the following modifications. The extruder included a 4-inch (101.6 mm) slit matrix at a temperature of 195 ° C. The screw speed was 30 revolutions per minute. A cooled coiling roll was used to collect the film. The cooled roller was operated at a sufficient speed to form a film having a thickness of about 4 mils (about 0.102 mm) and was maintained at a temperature of 15-20oC. Dry stress tests were carried out on a Sintech 1 / D voltage tester available from MTS Systems Corporation of Machesny Park, Illinois. The film was cut into a type V dog bone shape according to ASTM D638. The test was carried out with a grip separation of 30 millimeters and a cross-check speed of 4 millimeters / second.

The wet tension tests were carried out on a Vitrodyne V1000 mini-voltage tester available from Chatillon, Greensboro, North Carolina. The film samples were placed on the handles and the test apparatus was immersed in non-agitated water at room temperature for 30 seconds. The test was then run under the same conditions as the dry stress test. The peak stress, the percent of stress at break, the energy, the break (as an area under a stress curve versus the stress) and the modulus were calculated using the actual measured stress values against the stress tester. for each dry or wet tension test. Peak effort was recorded as the highest stress value. The percent of tension at break was recorded as the percent of tension at break. The energy to the break (curve of area under stress against tension) was calculated by adding the rectangular "slices" under the curve determined for each voltage value recorded from the voltage tester, using the following formula: (Stress valuex - Stress value, ..!) X (Stress value ,, + Stress value, ^) / 2 where "X" is the number in sequence of the slice. The module was calculated by linear regression of the initial region of the stress curve against tension. The dry and wet properties of the film produced from the mixture in Comparative Example A are indicated in Table 1 given below.

Table 1 Loss in Stress Properties with the Humedecimiepto This example shows that the polymer blend of the unmodified low density polyethylene with poly (ethylene oxide) having a weight average molecular weight of 200,000 g / mol is water resistant. The polymer mixture was not modifiable with water after 30 seconds of immersion in the water.

Examples 1-4 A resin mixture of 60/40 percent by weight of low density polyethylene (Dow 5031) and poly (ethylene oxide) having a molecular weight of 200,000 g / mol (from Union Carbide POLYOX® SRN-80) was fed to a Haake extruder as described in Comparative Example A at a rate of 5 pounds / hour (2.27 kilograms / hour). Concurrently with the polymer supply to the extruder, the specified amounts of the monomer, of PEG-MA and of the free radical initiator (Lupersol® 101) were added to the supply throat. The extruder had four heating zones opposite 170oc, 180oC, 180oC and 190oc. The screw speed of the extruder was 150 revolutions per minute.

For Example 1, the PEG-MA delivery rate was 0.125 pounds / hour (0.057 kilograms / hour) and the initiator rate was 0.0125 pounds / hour (0.0057 kilograms / hour).

For Example 2, the PEG-MA delivery rate was 0.25 pounds / hour (0.113 kilograms / hour) and the initiator rate was 0.025 pounds / hour (0.011 kilograms / hour).

For Example 3, the PEG-MA delivery rate was 0.5 pounds / hour (0.227 kilograms / hour) and the initiator rate was 0.025 pounds / hour (0.011 kilograms / hour).

For Example 4, the PE1G-MA delivery rate was 0.75 pounds / hour (0.34 kilogram / hour) and the initiator rate was 0.0375 pounds / hour (0.017 kilogram / hour).

The wet and dry properties of the film produced from the blends in Examples 1-4 are indicated in Table 2 given below.

For Examples 1-4 the amount of monomer grafted to polyethylene was 0.65 percent by weight, 1.03 percent by weight, 0.51 percent by weight and 1.13 percent by weight, respectively . The weight percent of the monomer grafted to the polyethylene was determined by FT-IR and the analysis of elemental oxygen content as described in the co-pending United States of America patent application No. 08 / 733,410 filed on October 18. 1996. For Example 3, the amount of monomer grafted to poly (ethylene oxide) was determined to be 9.66 percent by weight by NMR proton spectroscopy.

According to the invention, Examples 1-4, water-modifiable or water-degradable films were polymer blends of 60 percent by weight of a modified polyethylene and 40 percent by weight of modified poly (ethylene oxide) wherein both polyethylene and poly (ethylene oxide) had a PEG-MA grafted thereto. The films of these polymer blends were modifiable with water after 30 seconds of immersion in water. A dramatic loss in tension properties was observed for the films from dry to wet.

Examples 5-8 For Examples 5-8, low density polyethylene, Dow 5031 and poly (ethylene oxide) (SRN-80) mixtures were prepared following the procedure of Example 1 having the proportions by weight of respective resin, the proportions of delivery of PEG-MA and the indicated initiator rates.

For Example 5, the mixture was 65/35 PE / PEO, the PEG-MA delivery rate was 0.5 pounds / hour and the initiator rate was 0.025 pounds / hour.

For Example 6, the mixture was 70/30 PE / PEO, the PEG-MA delivery rate was 0.5 pounds / hour and the initiator rate was 0.025 pounds / hour.

For Example 7, the mixture was 75/25 PE / PEO, the PEG-MA delivery rate was 0.5 pounds / hour and the initiator rate was 0.025 pounds / hour.

For Example 8, the mixture was 80/20 PE / PEO, the PEG-MA delivery rate was 0.5 pounds / hour and the initiator rate was 0.025 pounds / hour.

The dry and wet properties of the film produced from the blends in Examples 5-8 are indicated in Table 3 given below.

Table 2 Percent Change in Stress Properties Table 3 15 Percent Change in Stress Properties twenty According to the invention, Examples 5-8 were films of polymer blends having more than about 60 percent by weight of a modified polyethylene and less than about 40 percent by weight of a modified poly (ethylene oxide) wherein both the polyethylene and the poly (ethylene oxide) had PEG-MA grafted thereto. The films of these polymer blends were modifiable with water after 30 seconds of immersion in water. A loss in tension properties was observed for the films from dry to wet.

Examples 9-12 For Examples 9-12, a 60/40 weight percent resin blend of low density polyethylene (Dow 5031) and poly (ethylene oxide) (Union Carbide WSRN-80) was prepared following the procedure of Example 1 , except that the monomer used was 2-hydroxyethyl methacrylate. The respective monomer supply rates and initiator rates are indicated.

For Example 9, the delivery rate of 2-hydroxyethyl methacrylate was 0.125 pounds / hour (C, 057 kilograms / hour) and the initiator rate was 0.0125 pounds / hour (0.0057 kilograms / hour).

For Example 10, the delivery rate of 2-hydroxyethyl methacrylate was 0.25 pounds / hour (0.114 kilograms / hour) and the initiator rate was 0.025 pounds / hour (0.114 kilograms / hour).

For Example 11, the delivery rate of 2-hydroxyethyl methacrylate was 0.5 pounds / hour (0.227 kilograms / hour) and the initiator rate was 0.025 pounds / hour (0.0114 kilograms / hour).

For Example 12, the ce-2-hydroxyethyl methacrylate delivery rate was 0.75 pounds / hour 10.34 kilograms / hour) and the initiator rate was 0.0375 pounds / hour (0.018 kilograms / hour).

The dry and wet properties of the film produced from the blends in Examples 9-12 are indicated in Table 4 given below. In accordance with this invention, Examples 9-12 were films of polymer blends having 60 percent by weight of a modified polyethylene and 40 percent by weight of modified poly (ethylene oxide) wherein both polyethylene and poly ( Ethylene oxide had 2-hydroxyethyl methacrylate grafted thereto The films of such polymer blends were water-modifiable or water-degradable after 30 seconds immersion in water.

For Examples 13-14, a resin mixture of 60/40 percent by weight of low density polyethylene (Dow 5031) and poly (ethylene oxide) having a molecular weight of 200. 000 g / mol (Union Carbide Polyox® SN-80) was fed to a ZSK-30 extruder as described in Examples 16 at a rate of 34 pounds / hour. The seven heating zones were all set at 180oC. The screw speed was 300 revolutions per minute. In barrel 4, the monomer (PEG-M?) Was added at the specified rate. In barrel 5, the free radical initiator (Lupersol® 101) was added at the specified rate.

For Example 13, the PEG-MA delivery rate was 1.02 pounds / hour (0.464 kilograms / hour) and the initiator rate was 0.068 pounds / hour (0.031 kilograms / hour).

For Example 14, the PEG-MA delivery rate was 3.06 pounds / hour (1.39 kilograms / hour) and the initiator rate was 0.17 pounds / hour (0.077 kilograms / hour).

The dry and wet properties of the film produced from the blends in Examples 17-18 are indicated in Table 5 given below.

According to the invention, Examples 13-14 were films of polymer blends with 60 percent by weight of a modified polyethylene and 40 percent by weight of modified poly (ethylene oxide) wherein both the polyethylene and the poly (ethylene oxide) have the PEG-MA grafted thereto. The films of these polymer blends were modifiable with water after 30 seconds of immersion in water.

Table 4 Percent Change in Stress Properties Table 5 15 Percent Change in Stress Properties twenty Examples 13-14 Although the invention has been described with reference to the preferred embodiments and illustrated in relation to a range of optional features, those skilled in the art will appreciate that various substitutions, omissions, changes and modifications may be made without departing from the spirit of the invention. invention as defined by the appended claims. Therefore, it is intended that the foregoing description be considered merely as an example of the preferred scope of the present invention and not be considered a limitation thereof.

Claims (20)

R E I V I N D I C A C I O N S

1. A water degradable film comprising more than about 55 percent by weight of a modified polyolefin and less than about 45 percent by weight of modified poly (ethylene oxide) wherein said film has a loss of at least 10% on two or more tensile properties selected from percent of stress at break, peak stress, energy at break and modulus after being submerged in water for 30 seconds.

2. A film, as claimed in clause 1, characterized in that it comprises from about 55 weight percent to about 85 weight percent of a modified polyolefin and from about 45 weight percent to about 15 percent by weight of a modified poly (ethylene oxide).

3. A movie, as claimed in clause 2, characterized in that it comprises from around 65 percent by weight to about 85 percent by weight of a modified polyolefin and from about 35 percent by weight to about 15 percent by weight of a modified poly (ethylene oxide).

4. A film, as claimed in clause 1, characterized in that said polyolefin is polyethylene or propylene.

5. A film, as claimed in clause 2, characterized in that said polyolefin is polyethylene or propylene.

6. A film, as claimed in clause 3, characterized in that said polyolefin is polyethylene or propylene.

7. A movie, as claimed e > n clause 4, characterized in that said modified polyolefin and said modified poly (ethylene oxide) have a total of from about 0.1 percent by weight to about 30 percent by weight of a monomer grafted onto said polyolefin and said poly (ethylene oxide).

8. A film, as claimed in clause 1, characterized in that said modified polyolefin and said modified poly (ethylene oxide) have a total of about 1 weight percent to about 20 weight percent of a monomer grafted onto said polyolefin and said poly (ethylene oxide).

9. A film, as claimed in clause 1, characterized in that said modified polyolefin and said modified poly (ethylene oxide) have a total of from about 1 weight percent to about 10 weight percent of a monomer grafted onto said polyolefin and said poly (ethylene oxide).

10. A film, as claimed in clause 7, characterized in that said monomer is 2-hydroxyethyl methacrylate or polyethylene glycol ethyl ether methacrylate.

11. A film, as claimed in clause 8, characterized in that said monomer is 2-hydroxyethyl methacrylate or polyethylene glycol ethyl ether methacrylate.

12. A film, as claimed in clause 9, characterized in that said monomer is 2-hydroxyethyl methacrylate or polyethylene glycol ethyl ether methacrylate.

13. A film, as claimed in clause 1, characterized in that said loss in two or more of the tension properties is greater than 25% after being immersed in water for 30 seconds.

14. A film, as claimed in clause 1, characterized in that said loss in two or more of the tension properties is from about 25% to about 98% after being immersed in water for 30 seconds.

15. A film, as claimed in clause 2, characterized in that said loss in two or more of the tensile properties is from about 30% to about 80% after being submerged in water for 30 seconds.

16. A degradable film in water that includes a mixture of a) at least 55 percent by weight of a polyolefin selected from polyethylene and modified polypropylene by having it grafted thereto from about 0.1 to about 30 percent by weight of 2-hydroxyethyl methacrylate or polyethylene glycol ethyl ether methacrylate; Y b) 45 percent by weight or less of poly (ethylene oxide) modified by the t.ener grafted thereto from about 0.1 percent by weight to about 30 percent by weight of 2-hydroxyethyl merylate or polyethylene glycol ethyl ether merylate; said degradable film in water shows a loss of at least 10 percent in two or more tensile properties selected from percent of stress at break, peak stress, energy at break and modulus after being immersed in water for 30 seconds.

17. A personal care item has a barrier or backing layer of a film comprising a mixture of a) at least 55 percent by weight of a polyolefin selected from polyethylene and polypropylene modified by having it grafted thereto from about 0.1 to about 30 percent by weight of 2-hydroxyethyl merylate or polyethylene glycol ethyl ether merylate; Y b) 45 percent by weight or less of poly (ethylene oxide) modified by having it grafted thereto from about: 0.1 percent by weight to about 30 percent by weight of 2-hydroxyethyl merylate or of polyethylene glycol ethyl ether merylate; said degradable film in water shows a loss of at least 10 percent in two or more tensile properties selected from the stress percent. to the break, peak effort, energy to the break and module after having submerged in water for 30 seconds.

18. An article for personal care as claimed in clause 17, characterized in said article is a towel for the hygiene of women.

19. An article for personal care as claimed in clause 17, characterized in said article is a diaper for infant.

20. An article for personal care as claimed in clause 17, characterized in said article is a diaper for infant. SUMMARY The invention provides a film containing a modified modified polyolefin-poly (ethylene oxide) degradable in water having more about 55 percent by weight of a modified polyolefin and less about (ie 45 percent by weight of a poly (modified ethylene oxide) The polyolefin and poly (ethylene oxide) polymers are modified by having them grafted thereon from about 0.1 percent by weight to about 30 percent by weight of a selected monomer of 2-hydroxyethyl merylate or polyethylene glycol ethyl ether merylate The modified modified polyolefin-poly (ethylene oxide) film of the invention, when immersed in water for about 30 seconds, loses at least 10% in two or more of tensile properties: percent of breaking stress, peak voltage, breaking energy and modulus when compared to dry values or prior to immersion. in which disposable personal care items with water discharge such as infant diapers, women's hygiene towels and adult incontinence garments are provided having a barrier or backing layer comprising a film of the invention containing modified polyolefin-poly (ethylene oxide) modified degradable in water.