AU733787B2 - Tampon applicator barrel and method for making same from a soft flexible composition - Google Patents

Description

AUSTRALIA

Patents Act COMPLETE SPECIFICATION

(ORIGINAL)

Class Int. Class Application Number: Lodged: Complete Specification Lodged: Accepted: Published: Priority Related Art: Name of Applicant: Playtex Products, Inc.

Actual Inventor(s): Karla E. Williams Paul D. Zwick Address for Service: PHILLIPS ORMONDE FITZPATRICK Patent and Trade Mark Attorneys 367 Collins Street Melbourne 3000 AUSTRALIA Invention Title: TAMPON APPLICATOR BARREL AND METHOD FOR MAKING SAME FROM A SOFT FLEXIBLE COMPOSITION Our Ref 592885 POF Code: 269236/325915 o The following statement is a full description of this invention, including the best method of performing it known to applicant(s): -1- TAMPON APPLICATOR BARREL AND METHOD FOR MAKING SAME FROM A SOFT FLEXIBLE COMPOSITION BACKGROUND OF THE INVENTION I. Field of the Invention The present invention relates generally to a soft, flexible material. More particularly, it relates to a thermoplastic composition that can be used to make a variety of products.that are soft and flexible. The thermoplastic composition is, preferably, a combination of a polyolefin and thermoplastic elastomeric materials. In addition, the thermoplastic composition may include one or more additional thermoplastic materials. Some uses envisioned for this composition are, for example, catamenial devices, baby care products, such as baby bottles and holders, pacifiers, toothbrushes and containers. One particular use of the .composition is for a tampon applicator and especially a tampon applicator barrel, that will be more comfortable and has a greater ease of insertion into the vagina than known such applicator barrels.

25 II. Description of the Prior Art Polyethylene is a thermoplastic that is the standard resin used to produce a number of products, including plastic tampon applicators. A softer applicator, especially an 30 applicator barrel, that-is more comfortable is a desirable feature of -a tampon applicator in'order to provide improved ease of insertion; It is generally known that thermoplastic elastomer articles may be combined with polyethylene to improve the strength and toughness of such articles. For example, U.S.

Patent No. 4,593,063 to M.A. Jones, et al., which issued June 3, 1986, provides a reinforced rigid polymer blend which yields a high gloss finish when injection molded. The thermoplastic elastomer includes 25 to 35 percent of a butadiene thermoplastic elastomer having a molecular weight of about 70,000 to about 100,000, a styrene content from about 25 to about 44 percent by weight and a melt flow rate from about 8 to about 15 grams per 10 minutes. The butadiene thermoplastic elastomer is blended with from about-54 toabout 75 percent of a rigid polymer, such as polyethylene.

Polymers have also been combined with polyethylene to improve their reaction to each other when heated.or otherwise processed. For example, U.S. Patent No. 4,678,834 to D.W.

Boivin, et al., which issued July 7, 1987, provides a polyolefin blend comprising a major portion of polyethylene and a minor portion of a second polymer, such as a styrenebutadiene-styrene copolymer. The second polymer :contains a reactive agent that is capable of reacting with polyolefins in a molten state. The reactive agent modifies or .stabilizes the polymer during processing or during use.

Polymers may also be added to polyethylene to permit a breakdown of its structural composition. Polyethylene, which is normally stable, has also been combined with less stable materials to produce biodegradable products. Such biodegradable products include ingredients that-cause oxidative actions in order to break down the polyethylene.

For example, U.S. Patent No. 5,212,219 to G.J.L.iGriffin, which issued May 18, 1993, provides a degradable article prepared from a blend of polyethylene and a less stable polymer or copolymer, such as a styrene-butadiene block copolymer. The composition further comprises an antioxidant active over a limited period and a pro-oxidant that causes a sharp loss of physical strength on depletion of the antioxidant. In addition, the presence of filler particles of a biologibally sensitive material accelerates the biological breakdown of the polymer/copolymer blend.

Improvements to the pelletizability and drapability of a polymer composition, without causing the composition to biodegrade, are also known. For example, U.S. Patent No.

4,833,195 to A.M. Adur, et al., which issued May 23, 1989, provides a thermoplastic polymer composition that can be conveniently converted into a drapable film or fabric.. The composition has a low Shore A hardness, below about and a high melt flow rate about 30 grams/10 minutes to 1100 minutes at 230 degrees Celsius and 2.16 kilograms.

Drapability is an important property of products that drape against a user's skin, such as .baby diapers or sanitary napkins.

However, .none _of the above patents describe or suggest a tampon applicator .that is composed of such materials. In fact, none of the above patents suggest the inventive -combination of polyethylene-and the unique elastomeric composition which improves flexibility, strength and tear resistance and, perhaps, softness, and can function as a compatibilizer with other thermoplastic polymeric materials.

Thus, the above patents do not suggest a flexible, soft 30 -tampon applicator having a unique blend of polyethylene and a rubber type -composition that includes a thermoplastic elastomer (TPE) -,namely a styrene-butadiene-styrene block copolymer, which applicator provides for comfortable and easy S* insertion into the vagina.

Further, thermoplastic resins are much less expensive than elastomeric materials. To minimize the costs of tampon applicators, one desires the greatest amount of thermoplastic resin as possible in the composition, but without adverse affects. Accordingly, to achieve the benefits of a flexible and easy to insert tampon applicator barrel and yet minimize costs, it is desired to use as little as possible of the elastomer components and as much as possible of the thermoplastic resin component in the tampon applicator barrel.

Other projected products, such as, for example, a holder for nurser liners or a nurser bottle, may desire the flexibility of the material in order to assist a child or parent in gripping the product and, perhaps, squeeze the product to remove contents.

Against the foregoing background, it would be useful to provide a composition that comprises a polyolefin and a thermoplastic elastomer. It would also be useful to provide such a composition that favorably adjusts the modulus of elasticity of the composition.

2 It would furthermore be desirable to provide such a composition in a 20 thermoplastic-type tampon applicator so that the barrel, in particular, is soft and flexible to provide more comfort and improved ease of insertion. It would also be desirable to provide such a tampon applicator at least one styrene-butadienestyrene block copolymer to achieve such desired properties.

25 SUMMARY OF THE INVENTION •il :According to one aspect of the present invention there is provided a soft, flexible polymeric composition including: a polyolefin; and at least two styrene-butadiene-styrene block copolymers, each having a percentage by weight of styrene different than the other, in amounts sufficient to adjust the elasticity of the composition, wherein said polyolefin is a low density 4 v O<j polyethylene.

W:kate\SPECI\41072-99.doc A preferred use of the composition is as a tampon applicator barrel that is more comfortable and has improved ease of insertion into the vagina. More specifically, the present invention is a soft, flexible tampon applicator that provides more comfort and improved ease of insertion into the vagina by the combination of a low density polyethylene and at least one styrene-butadienestyrene block copolymer. In one form, there are at least two styrene-butadienestyrene block copolymers, each having a different percent by weight of styrene.

In a preferred embodiment, there are three styrene-butadiene-styrene block copolymers each having a percentage by weight of styrene that is different than that of the other two copolymers.

In a further aspect of the present invention, there is provided a tampon applicator barrel, adapted to accept a plunger, said applicator barrel having a soft, flexible body for comfort and ease of insertion into the vagina including: a low density polyethylene; at least three styrene-butadiene-styrene block copolymers, each styrenebutadiene-styrene block copolymer having percentage by weight of styrene different than that of the other two block copolymers; 2 a compatibilizer/flow modifier; and a plasticizer.

Preferably, the first styrene-butadiene-styrene block copolymer has about 29 percent by weight of styrene, the second styrene-butadiene-styrene block copolymer has about 31 percent by weight of styrene, and the third styrenebutadiene-styrene block copolymer has about 43 percent by weight of styrene.

The polymeric resin may further comprise other ingredients, such as a pigment, a slip/mold release agent, an antioxidant and, perhaps, an antistat ingredient.

6 The present invention, in another aspect, provides a method for making a composition that can be made into a soft, flexible product. An elastomeric composition, which includes a plurality of styrene-butadiene-styrene block copolymers, is melted and combined to form a melted resin which is then extruded into a plurality of soft resin pellets. The plurality of soft resin pellets are then dry blended with a plurality of pellets of a low density polyethylene to form a pellet mixture. Finally, the pellet mixture is melted together to form a polymeric compound and molded to a desired shape. In a preferred embodiment, the method is used to make a tampon applicator, especially an applicator barrel, that has a soft and flexible structure for more comfort and improved ease of insertion into the vagina.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT The present invention provides a new polymeric compound or composition that is a combination of a polyolefin and a rubber type composition that adjusts the softness and flexibility of the polymeric compound. As stated above, while it is envisioned that this material may be used to form a variety of products, such as, for example, baby or nurser bottles and holders, pacifiers, toothbrushes and containers, 00 0..o *oo W:,ate',SPEC141072.99.doc a preferred application is for catamenial devices. A particularly preferred applicator is a tampon applicator, especially an applicator barrel, composed of this new polymeric compound.

To minimize costs, it is preferable that the tampon applicator have an applicator barrel that uses the polymeric compound of the present invention, while the plunger is made, perhaps, of less expensive material. A softer applicator barrel is more comfortable and is a desirable feature of a tampon applicator in order to provide improved ease of insertion. Accordingly, the present application is directed to a tampon applicator barrel, however it can be used for the entire tampon applicator.

The polymeric compound comprises polyolefin and a rubber type composition that adjusts the softness and flexibility of the polymeric compound and, thus, the tampon applicator. For the preferred embodiment, the polyolefin is a low density polyethylene -and the rubber type composition includes a thermoplastic elastomer. The thermoplastic elastomers could include thermoplastic vulcanizates, thermoplastic olefins, styrene block copolymers, thermoplastic urethanes .and combinations thereof. In the most preferred embodiment, the thermoplastic elastomer is a plurality of styrene-butadienestyrene block copolymers.

The primary supporting structure of the soft applicator barrel is provided by the polyolefin. .The preferred type of 30 polyolefin is polyethylene, -and, more preferably, low density polyethylene. The polyethylene caribe"a linear low density polyethylene. For the preferred embodiment, the polyolefin is about 25 to about 75 percent by weight of the total weight of the polymeric compound.

The thermoplastic elastomers are combined with the polyolefin in amounts sufficient to adjust the elasticity of the polymeric compound.

Styrene-butadiene-styrene block copolymers are the preferred thermoplastic elastomers. A combination of three different types of styrene-butadiene-styrene block copolymers having different contents of styrene is the more preferred.

In a most preferred embodiment, a first styrene-butadienestyrene block copolymer has 29 percent by weight of styrene .in the block copolymer, a molecular weight of 80,000 and a melt flow rate 8 gram per 10 minutes, a second styrenebutadiene-styrene block copolymer has 31 percent by weight of styrene, a molecular weight of 100,000 and a melt flow rate less than 1 gram per 10 minutes, and a third styrene- :butadiene-styrene block copolymer has 43 percent by weight of styrene, a molecular weight of 58,000 and a melt flow rate 23 gram per 10 minutes. The melt flow-rate for all three styrene-butadiene-styrene block copolymers is measured -at 200 degrees Celsius with a 5.0 kg load. Such first, second and third styrene-butadiene-styrene block copolymers are "commercially available as Vector Resin 8550, Vector Resin 2518, and Vector Resin 6241, respectively. These copolymers 25 are manufactured by Dexco Polymers (a Dow/Exxon Partnership) of Houston, Texas.

Each of the first, second and third styrene-butadienestyrene block copolymers is about 5.5 to about 16.6 percent S 30 by weight of the total weight of the polymeric compound.

Accordingly, the weight of the block copolymers is about 16.5 to about 49.80 by weight of the total weight of the polymeric .compound.

The combination of these three block copolymers has been found to provide the optimum viscosity desired so that the thermoplastic resin phase, namely polyethylene, and the rubber phase are compatible.

The rubber type composition that is added to the polyolefin may also include other materials. It is preferred that a plasticizer, such as mineral oil, be used to reduce the viscosity and hardness. The plasticizer is about 5 to about 15 percent by weight of the total weight of the polymeric compound. In addition, the rubber type composition may contain a filler, such as CaCO3 or talc.

It is also preferred that the polymeric compound include a compatibilizer/flow modifier, which assists in the blending or compatibilization of the thermoplastic resin and the rubber materials, and to improve the tear resistance and elongation properties of the compound. Preferably, the compatibilizer/flow modifier is.a copolymer. In the preferred embodiments, the copolymer is an alpha olefin.

copolymer,. namely an ethylene copolymer. In the most preferred embodiment, the ethylene copolymer is ethylene methyl acrylate. Alternative alpha olefin copolymers that can be used are ethylene vinyl acetate, ethylene ethyl 25 acrylate, ethylene butyl acrylate and mixtures thereof.

Ethylene methyl acrylate is the most preferred since it, unlike ethylene vinyl acetate, will not decompose under high molding temperatures, and is less expensive than either ethylene ethyl acrylate or ethylene butyl acrylate.

The compatibilizer/flow modifier is present in -anamount about 2.9 to about 8.6 percent by weight of the total weight of the polymeric compound.

The rubber type composition may further include additives, such as a pigment or color additive, a slip/mold release agent, an antioxidant and/or an antistat, that may be necessary to facilitate the manufacture or otherwise improve the quality of the tampon applicator or barrel.

The pigment, that is chosen to provide the.desired aesthetic effect, is preferably titanium dioxide. It is about 0.5 to about 1.5 percent weight of the total weight of the polymeric resin.

The slip/mold release agent is, preferably, a fatty acid amide, such as, erucamide. Alternatively, the slip/mold release agent can be metallic stearates, calcium stearate, ethylene bis stearamide and ethylene bis oleamide. In a preferred embodiment for use in a tampon applicator barrel, erucamide is present in an amount about 0.8 percent by weight of the total weight of the polymeric compound. While erucamide is a preferred slip release agent, -an erucamide slip agent may undergo substantial blooming subsequent to molding. -Such blooming will result in an agglomeration of the erucamide slip release agent on the surface of the molded polymeric article that can cause gumming and contamination problems in equipment if substantial post-molding handling of the article is required. Surprisingly, stearyl erucamide has been found to avoid the blooming problem. The use of higher e* amounts, about of stearyl erucamide is preferred.

Accordingly, stearyl erucamide has been found to particularly improve the process of manufacture of a tampon applicator and tampon applicator barrel that require significant handling .after molding. When stearyl erucamide is used, a higher S,**:amount of the release agent,' for example up to about 3 percent by weight of the total weight:of -the composition, may be used. Accordingly, the slip/mold release agent can be .9 e 99* present in a range about 0.4 to about 3 percent by weight of the total weight of the polymeric compound.

The antioxidant provides stability to the polymeric compound. It is preferred that the antioxidant be a combination of two antioxidants. One antioxidant is tetrakis [methylene (3,5-di-tert-butyl-4-hydroxyhydrocinnamate)] methane. -The other antioxidant is tris 4-di-tert-butyl phenyl) phosphite. Such antioxidants/stabilizers are manufactured under the product names Irganox 1010 and Irgafos 168, respectively, by Ciba-Geigy Corporation. Each antioxidant is about 0.05 to about 0.15 percent by weight of the total weight of the polymeric compound.

When there is substantial handling of the molded article, such as, for example, a tampon applicator or tampon applicator barrel, the most preferred embodiment of the present-composition has the following ingredients and their approximate percent by weight of the total composition: TABLE A about 63% low density polyethylene; Sabout first styrene-butadiene-styrene block copolymer having about 29 percent of styrene; S 25 about 8% second styrene-butadiene-styrene block copolymer having about 31 percent of styrene; about 8% third styrene-butadiene-styrene block Scopolymer having about 43 percent of 30 styrene; about 7% mineral oil as the plasticizer; about 4% ethylene methyl ;acrylate as the compatabilizer/flow modifier; Sabout 1 d e a the pigme S. about 1% titanium dioxide-as the pigment; 11 about 1.5% stearyl erucamide as the slip/mold release agent; less than 1% tetrakis [methylene (3,5-di-tert-butyl-4hydroxyhydrocinnamate)] methane as a stabilizer/antioxidant; and less than 1% tris 4-di-tert-butyl phenyl) phosphite as a stabilizer/antioxidant.

Higher styrene contents would tend to make the elastomer material less soft and less flexible. In a preferred embodiment of the polymeric compound, the amount of the third styrene-butadiene-styrene block copolymer is about one-half of one percent less than the amount of the first or second styrene-butadiene-styrene block copolymers.

It is to be understood that an antistatic agent or antistat may be added to the polymeric compound but is not a part of the preferred embodiment. The antistat imparts a slight to moderate degree of electrical conductivity to plastic compounds, thus preventing the accumulation of electrostatic charges on the soft applicator. The antistat may be incorporated in -the ingredients before molding, or Sapplied to the outer surface of the tampon applicator or barrel after molding..

The preferred method for making the preferred polymeric compound that is formed into an applicator or applicator barrel is as follows. The three styrenee butadiene-styrene block copolymers, mineral oil, ethylene 30 methyl acrylate, stearyl erucamide and the antioxidants (and pigment, if used) are weighed and then combined in a twin screw extruder that melts and blends the ingredients and forms a melted .resin.: The melted resin is then extruded and.

cut into soft resin pellets. These soft resin pellets are then dry blended with pellets of the remaining ingredient, i.e. the low density polyethylene, to form a pellet mixture.

The pellet mixture of low density polyethylene pellets and soft resin pellets are then melted and injection molded to form the desired shape for the soft tampon applicator or applicator barrel.

An alternative method for making the preferred polymeric compound that is formed into an applicator or applicator barrel includes weighing all ingredients including the low density polyethylene and then combining them in a twin screw extruder to form the melted compound. The melted compound is then extruded and cut into pellets which are then injection molded to form the desired shape for the tampon applicator or applicator barrel.

In order to exemplify-the effectiveness of the composition comprising low density polyethylene and.the styrene-butadiene-styrene block copolymers verses conventional low .density polyethylene based compositions, the following comparison test was conducted of tampon applicator barrels.

An element of "softness" is flexibility. In order 25 to test for flexibility, Instron compression testing was performed to compare differences in flexibility of the tampon applicator barrel of the preferred embodiment against the four known thermoplastic applicator barrels.

The Instron compression test was designed to treat the whole barrel as a tubular specimen. A 5/8 inch wide platen is used to radially compress the applicator barrel against a 6 inch anvil. The specimen is placed on the anvil so that the platen engages the barrel at an axial location 13 between 1 3/8 inch and 2 3/16 inch as measured from the finger grip end of the applicator barrel. The specimen is compressed by a total of 0.25 inch at a rate of inch/minute.

As shown in Table B below, the Instron compression test produced the following results.

TABLE B: Instron Compression Testing Tampon applicator barrels having an outside diameter about 0.67 inches inches and a wall thickness about .027 inches inches

LOAD

Ibs.

(std. dev.)

YOUNG'S

MODULUS

psi (std. dev.)

ENERGY

Ibs. -inch (std.dev.) r r Known Branded Thermoplastic applicators Preferred Composition Applicator 2.22 to 3.59 (0.16) (0.22) 1.74 (0.10) 191.9 to 277.5 (20.4) (28.9) 104.2 (11.8) 0.28 to 0.46 (0.02) (0.03) 0.22 (0.01) r C:WINIORD'J(ATE.U(ATE'PWWGNOOELETE'PS7544.DOC Tampon applicator barrels having an outside diameter about 0.56 inches inches and a wall thickness about .027 inches inches.

LOAD YOUNG'S ENERGY

MODULUS

Ibs. psi Ibs. -inch (std. dev.) (std. dev.) (std.dev.) Known Branded Thermoplastic applicators 3.11 to 4.85 239.4 to 474.8 0.40 to 0.62 (0.28) (0.27) (26.6) (59.3) (0.04) (0.05) Preferred Composition 1.96 113.0 0.25 Applicator (0.20) (17.6) (0.03) The standard deviation of the four known branded thermoplastic applicator barrels is different for each applicator barrel. Accordingly, there is a range for the known thermoplastic applicators with a standard deviation for the lowest number and largest number in the range. It should be understood that the grade of material, diameter and wall thickness of the barrel are the three factors that affect flexibility, and that flexibility is determined by the load, Young's modulus or modulus of elasticity, and energy.

Young's modulus, also known in the art as modulus of elasticity, is a measurement for flexibility. It is the ratio of a nominal stress to corresponding strain below the proportional limit of a material. Young's modulus is expressed in :i force per unit area, usually Ibs. per square inch (psi) as shown in Table B.

C:\WWNWORDIJ(ATELKATEPWGINODELETE\P7544.O The larger diameter, preferred composition applicator has an outside diameter about 0.60 inches. As shown in Table B, it has been found significantly more flexible than known thermoplastic applicators. For the larger outside diameter applicator barrels, about 0.60 to about 0.74 inches (0.67 inches inches), the load results indicate that the inches inches), the load results indicate that the applicator barrel made with the preferred polymeric compound requires about 1.74 Ibs. to radially compress the applicator barrel by 0.25 inches, whereas the four known thermoplastic applicator barrels require about 2.22 Ibs. to about 3.59 Ibs. In addition, Young's modulus or the modulus of elasticity for the present applicator barrel is about 104 psi, whereas the known thermoplastic applicators is about 192 psi to about 278 psi. Also, the energy to compress by 0.25 inches the present applicator barrel is about 0.22 Ibs. -inch, whereas the known applicator barrels are about 0.28 to 0.46 Ibs. -inch.

It would be expected that the smaller the outside diameter of the barrel, the higher the Young's modulus. Accordingly, the results of the present applicator barrel (having an outside diameter of about 0.60 inches) to the known applicator barrels having an outside diameter from 0.60 to 0.74 is even more remarkable.

:.i 20 For the smaller outside diameter applicator barrels, i.e. about 0.50 to about .0 0.62 inches (0.56 inches the load results indicate that the applicator barrel made with the preferred polymeric compound (having an outside diameter about 0.54 inches) requires about 1.96 Ibs. to radially compress the applicator barrel 0.25 inches, whereas the known thermoplastic applicator barrels require about 000: 25 3.11 Ibs. to about 4.85 Ibs. to compress 0.25 inches. In addition, the modulus of elasticity for the present applicator barrel is about 113 psi, whereas the modulus of elasticity for the known thermoplastic applicator barrels is about 240 psi to about 475 psi. Also, the energy to compress by 0.25 inches the present ."o:applicator barrel is about 0.25 Ibs. -inch, whereas such energy to compress the 30 known 16 C :WNWORDDKATOECLTEPWGIOOELETEIP5754.DC applicator barrels the same amount is about 0.40 to 0.62 Ibs.-inch.

Thus, present or soft applicators made with the preferred polymeric compound of the present invention have a load, m6dulus of elasticity and energy approximately one-half that of all known thermoplastic applicator barrels. In addition,- applicator barrels of the present invention have been found by consumers as a unique, softer applicator barrel due to the tactile feel of the applicator barrels.

In addition to improved "softness" and "flexibility", the polymeric compound or composition of the present composition has been found to have improved strength and tear resistance. The following test demonstrates the unexpected improvement in strength and tear resistance.

Samples A through D were manufactured by combining three block copolymers, -a.plasticizer, a compatibilizer/flow modifier, mold release agents, antioxidants/stabilizers and a pigment, and in the .percentages set forth in Table C. They were -compared with a "comparative" sample made of a combination of one block copolymer, along with an analogous plasticizer, mold release agents, antioxidants/stabilizers 25 and pigment. For-each sample and the comparative, the mixed compositions were made according to the preferred method set forth above. In particular, each mixed composition was passed through a twin screw extruder that melted and blended the ingredients and extruded to form a melted resin that is then cut into soft resin pellets. The soft resin pellets were then dry blended with pellets of low density polyethylene to form a pellet mixture. The pellet mixture was then melted and injection molded to form ASTM test articles. The four samples and the comparator were evaluated 17 samples, each with three block copolymers, as compared to the one block copolymer comparative, demonstrated significantly improved strength and tear resistance properties.

In addition, the preferred composition noted as D in Table D'and also set forth in Table A, has the best combination of softness, flexibility, strength and tear resistance of all compositions tested.

TABLE C Ingredients Styrene-butadiene-styrene (29% styrene) Styrene-butadiene-styrene (31% styrene) Styrene-butadiene-styrene (43% styrene) Mineral Oil -Ethylene-methyl acrylate Stearyl erucamide Irganox 1010 Irgafos 168 Low density polyethylene 25 Ethylene vinyl acetate Titanium Erucamide -B C D- Comp.

10.48 8.90 11.93 -8.0 29.97 10.48 8.90 11.93 7.20 8.32 7.13 8.12 20MI) 4.68 1.83 <0.1 <01 58.40 58.40 d4 A 8.22 8.12 7.0 S- 1.5 <0.1 <0.1 <0.1 <0.1 58.20 63.0.

0.23 .63 0.1 <0.1 8.20 r r r r r r A. R 0.80 0.64 0;.78 0.80 0.63 1.0 0.63 *Comparative TABLE D Sample A B C D Comparative Elongation, (ASTM D638) 170 246 162 227 86 Tensile Strength psi. 820 878 862 917 753 (ASTM D638) Tear Resistance (ATM D624) 218 234 167 248 132 The present invention having been thus described with particular reference to the preferred forms thereof, it will be obvious that various changes and modifications may be made therein without departing from the spirit and scope of the invention as defined in the appended claims.

It is to be appreciated that throughout the description and claims of this specification the word "comprise" and variations of that word, such as "comprises" and "comprising", are not intended to exclude other additives or components or integers or steps.

e 19 C:;\WNWORD\KATEL\KATEPWG\NODELETEIP57544DOC

Claims (36)

1. A tampon applicator barrel, adapted to accept a plunger, said applicator barrel having a soft, flexible body for comfort and ease of insertion into the vagina including: a low density polyethylene; at least three styrene-butadiene-styrene block copolymers, each styrene- butadiene-styrene block copolymer having percentage by weight of styrene different than that of the other two block copolymers; a compatibilizer/flow modifier; and a plasticizer.

2. A tampon applicator barrel as claimed in claim 1, further including an antioxidant.

3. A tampon applicator barrel as claimed in claim 1 or claim 2, further including a slip/mold release agent.

4. A tampon applicator barrel as claimed in any one of claims 1 to 3, wherein 20 a first of said at least three block copolymers has about 29 percent by weight of styrene.

A tampon applicator barrel as claimed in claim 4, wherein a second of said at least three block copolymers has about 31 percent by weight of styrene.

6. A tampon applicator barrel as claimed in claim 5, wherein a third of said at o.o least three block copolymers has about 43 percent by weight of styrene.

7. A tampon applicator barrel as claimed in any one of claims 1 to 6, wherein 30 said low density polyethylene is about 25 to about 75 percent by weight of the total weight of the tampon applicator barrel. VT C:\W1NWORDKYLIE\NODEL57544-96.DOC

8. A tampon applicator barrel as claimed in any one of claims 1 to 7, wherein said each styrene-butadiene-styrene block copolymers is present in an amount about 5.5 to about 16.6 percent by weight of the total weight of the tampon applicator barrel.

9. A tampon applicator barrel as claimed in any one of claims 1 to 8, wherein said compatibilizer/flow modifier is an ethylene copolymer, and wherein said plasticizer is mineral oil.

A tampon applicator barrel as claimed in claim 2, wherein said antioxidant is at least two antioxidants, and wherein said at least two antioxidants are tetrakis [methylene (3,5-di-tert-butyl-4-hydroxyhydrocinnamate)] methane and tris (2,4-di- tert-butyl phenol) phosphite.

11. A tampon applicator barrel, adapted to receive a plunger, said applicator barrel having a soft, flexible body for comfort and ease of insertion into the vagina including: a low density polyethylene; 20 at least three styrene-butadiene-styrene block copolymers, each styrene- butadiene-styrene block copolymer having percentage by weight of styrene S: different than that of the other two block copolymers; an alpha olefin compatibilizer/flow modifier; a plasticizer; 25 a plurality of antioxidants; and a slip/mold release agent.

12. A tampon applicator as claimed in claim 11, further including a pigment. VT C:\WNWORO\KMIE\NODEL\57544-96.DOC 22

13. A method for making a tampon applicator barrel having a soft, flexible supporting structure including the steps of: combining an elastomeric composition, including melting said elastomeric composition, to form a melted resin; extruding said melted resin into a plurality of soft pellets; dry blending said plurality of soft pellets with a plurality of pellets of a low density polyethylene to form a pellet mixture; melting said pellet mixture together to form a polymeric compound; and molding said polymeric compound to a desired shape for the tampon applicator barrel, wherein said elastomeric composition includes a plurality of styrene- butadiene-styrene block copolymers.

14. A method as claimed in claim 13, wherein the step of combining said plurality of block copolymers includes combining said plurality of block copolymers includes combining said plurality of block copolymers with a plasticizer, a compatibilizer/flow modifier, a slip/mold release agent, and an antioxidant. 20

15. A method as claimed in claim 14, said combining step includes the step of situating said plurality of styrene-butadiene-styrene block copolymers, said plasticizer, said compatibilizer/flow modifier, said slip/mold release agent, and said antioxidant in a twin screw extruder before combining said block copolymers so that said plurality of block copolymers are combined and melted within said i 25 twin screw extruder.

16. A method as claimed in claim 14, further including the step of combining polyethylene with the elastomeric composition prior to the step of extruding. S W:\kate\SPECI'41072-99.doc 23

17. A soft, flexible polymeric composition including: a polyolefin; and at least two styrene-butadiene-styrene block copolymers, each having a percentage by weight of styrene different than the other, in amounts sufficient to adjust the elasticity of the composition, wherein said polyolefin is a low density polyethylene.

18. A composition as claimed in claim 17, wherein said at least two styrene- butadiene-styrene block copolymers is three styrene-butadiene-styrene block copolymers, each having a different percentage by weight of styrene.

19. A composition as claimed in claim 18, wherein a first of said at least three block copolymers has about 29 percent by weight of styrene.

20. A composition as claimed in claim 18 or claim 19, wherein a second of said at least three block copolymers has about 31 percent by weight of styrene.

21. A composition as claimed in any one of claims 18 to 20, wherein a third of said at least three block copolymers has about 43 percent by weight of styrene.

22. A composition as claimed in claim 18, wherein each of said at least three block copolymers is present in an amount about 5.5 to about 16.6 percent by weight of the total weight of the composition. 25

23. A composition as claimed in any one of claims 17 to 22, wherein said low density polyethylene is about 25 to about 75 percent by weight of the total weight of the composition.

24. A composition as claimed in any one of claims 17 to 23, further including a flow modifier.

W:1kate\SPECM1072.99.doc A composition as claimed in claim 24, wherein said flow modifier is an ethylene copolymer.

26. A composition as claimed in claim 25, wherein said ethylene copolymer is ethylene methyl acrylate.

27. A composition as claimed in any one of claims 17 to 26, further including a plasticizer.

28. A composition as claimed in claim 27, wherein said plasticizer is mineral oil.

29. A composition as claimed in claim 27 or claim 28, wherein said plasticizer is about 5 to about 15 percent by weight of the total weight of the composition.

A composition as claimed in any one of claims 17 to 29, further including a slip/mold release agent.

31. A composition as claimed in claim 30, wherein said slip/mold release agent 20 is stearyl erucamide.

32. A composition as claimed in any one of claims 17 to 31 further including an antioxidant. 25

33. A composition as claimed in claim 32, wherein said antioxidant is selected from the group consisting of tetrakis [methylene (3,5-di-tert-butyl-4-hydroxyhydro- -cinnamate)]methane and tris (2,4-di-tert-butyl phenol) phosphite.

34. A tampon applicator barrel substantially as herein described with reference to the examples.

W:\kateSPECI\41072-9.doc A soft flexible polymeric composition substantially as herein described with reference to the examples.

36. A method for making a tampon applicator barrel substantially as herein described with reference to the examples. DATED: 7 March 2001 PHILLIPS ORMONDE FITZPATRICK Attorneys for: PLAYTEX PRODUCTS, INC. 0.o0 *000 W:\kate\SPECM1072-99.doc