The invention is directed to the use of a linear low density polyethylene (LLDPE) composition in health care applications.

The healthcare market is continuously searching for improved polymer grades for rigid and flexible products, ensuring a consistent approach to the medical and healthcare market. Because of the material properties polyethylene is used in many health care applications. As an example, a film must have the required mechanical properties such as tear resistance, impact resistance and tensile strength, the required chemical resistance such as environmental stress crack resistance, the required optical properties such as gloss, haze and clarity, the required sealing and hot tack properties. Furthermore the polymer to be applied in such healthcare applications must be compliant to the legal requirements such as the European Pharmacopoeia standard tests and USP Class VI compliant.

It is the object of the present invention to provide a polymer composition that meets the legal requirements and also the technical requirements of a wide variety of health care applications.

The present invention is directed to the use of a composition comprising linear low density polyethylene and an inorganic acid scavenger in health care applications.

In another embodiment, the invention is directed to the composition comprising linear low density polyethylene and an inorganic acid scavenger for use in health care applications. Without wishing to be bound by theory, the inorganic acid scavenger neutralizes the catalyst residues from the catalyst used in the preparation of the LLDPE.

Examples of suitable inorganic acid scavengers include aluminium oxide, zinc oxide, calcium oxide, calcium hydroxide, magnesium oxide, magnesium hydroxide, hydrotalcites, as for example commercially available as DHT4A and mixtures of any one of these inorganic acid scavengers. Therefore, the invention also relates to the use of a composition comprising linear low density polyethylene and inorganic acid scavenger, wherein the inorganic acid scavenger is selected from the group of aluminium oxide, zinc oxide, calcium oxide, calcium hydroxide, magnesium oxide, magnesium hydroxide,

hydrotalcites and any mixtures of any one of these inorganic acid scavengers. Preferably zinc oxide, calcium oxide, magnesium oxide or any mixtures of any of these oxides are used as inorganic acid scavenger. For example, the inorganic acid scavenger is selected from the group of zinc oxide, calcium oxide and magnesium oxide. Most preferably, the inorganic acid scavenger is zinc oxide. The composition comprising linear low density polyethylene and an inorganic acid scavenger meets the requirements of the European Pharmacopoeia standard tests as described herein.

In order to meet the requirements of the European Pharmacopoeia,

components may not leach out of the article and may not be extractable from the article in an amount above the limits set by the European Pharmacopoeia.

This polymer composition may suitably be used in health care applications because this composition may have one or more of the following advantages: good mechanical properties, mechanical properties, chemical resistance, and/or hot tack properties.

The LLDPE composition according to the invention can be applied in healthcare applications such as pharmacy pouches/bags because of the obtained puncture resistance and the hot tack properties, tubes because of the obtained

Environmental Stress Crack Resistance (ESCR), multilayer medical films, intermediate packaging for example for sharp objects in the operating room and in building blocks for example LLDPE and LDPE blends for infusion bags and bottles.

Therefore, the invention also relates to the use of the invention, wherein the composition is in the form of a pharmacy pouch, tube, multilayer film, intermediate packaging, infusion bag or bottle, or a medical device, for example any medical device where the typical LLDPE properties can be of advantage.

Therefore, in another aspect, the invention also relates to pharmacy pouch, tube, multilayer film, intermediate packaging, infusion bag or a bottle prepared from a composition as described herein.

The use of the composition according to the invention results in stearate free compositions to be applied for example in dialysis applications. Furthermore, the composition of the invention provides compositions that preferably do not contain compounds from a living source, such as an animal source, for example a bovine source or a vegetable source.

The LLDPE composition according to the invention results in an excellent final product not only from a mechanical point of view but also from a sustainability one because down gauging is possible and therefore less material is used in the final package.

The pharmaceutical packaging market can be divided into primary packaging that is in direct contact with the active pharmacy ingredient and includes blister packs, fluid bags, pouches, bottles, vials and ampoules and into secondary packaging which includes every part of the total concept or medical device that is not in direct contact with the packed drug or fluid. The polymer composition according to the invention provides a low interaction between the packaging and the active pharmacy ingredient.

The linear low density polyethylene component of the composition is a low density polyethylene copolymer comprising ethylene and a C3- do alpha-olefin co monomer. Suitable alpha-olefin co monomers include butene, hexene, 4- methyl pentene and octene.

According to a preferred embodiment of the invention the co monomer is hexene and octene.

According to a preferred embodiment of the invention the co monomer is hexene.

Preferably, the alpha-olefin co monomer is present in an amount ranging between 5 and 20 percent by weight of the ethylene-alpha olefin copolymer. More preferably this amount ranges between 7 and 15 percent by weight. For example, the amount of alpha-olefin co monomer is at least 5, for example at least 7 and/or at most 20, for example at most 15 percent by weight. Preferably the linear low density polyethylene has a density in the range between 915 kg/m ³ and 930 kg/m ³ .

More preferably the linear low density polyethylene has a density in the range between 915 kg/m ³ and 920 kg/m ³

Preferably the linear low density polyethylene has a melt flow rate as determined using IS01 133 (2.16 kg/190 °C) in the range between 0.33 and 30 g/10 minutes. Preferably the inorganic natural acid scavenger additive is added in an extruder after polymerisation of LLDPE.

The optimal amount of the inorganic acid scavenger depends on the catalyst system selected for the polymerisation of LLDPE and on the efficiency of that catalyst system during the production of LLDPE. Generally, the compositions of the invention may contain an amount of inorganic acid scavenger in the range from 100 to 1500ppm, for example in the range from 400 to 800 ppm, for example in the range from 500 to 750 ppm, for example in the range from 600 to 700ppm, for example in the range from 300 to 500ppm, for example in the range from 315 to 385ppm.

The composition may consist of LLDPE and an inorganic acid scavenger, for example in an amount of 100 to 1500 ppm on the total composition, but LLDPE may also be present in an amount of 50 to 99wt%, for example in an amount of at most 95wt%, for example at most 90wt%, for example at most 85wt%, for example at most 75wt% based on the total composition. The composition may further comprise low density polyethylene (LDPE), for example in a weight ratio of LDPE to LLDPE of 10/90 to 50/50, for example 20/80 to 50/50, for example 25/75 to 50/50. The presence of LDPE in the composition of the invention may have the advantage of increased

processability and/or increased optical properties.

Preferably the density of the LDPE ranges between 915 kg/m ³ and 928 kg/m ³ . Preferably the LDPE has a melt flow rate as determined using IS01 133 (2.16 kg/190 °C) in the range between between 0.2 and 3 g/10min. The polymer composition may also comprise additives, for example process stabilisers, antioxidants and light stabilizers, for example UV stabilizers.

Suitable examples of these additives include for example tris(2,4-di-t-butyl phenyl) phosphite, octadecyl 3,5-bis (1 ,1 -dimethyl)-4-hydroxybenzene propionate and pentaerytritol tetrakis(3-(3,5-di-t-butyl-4-hydroxyphenol) propionate.

The polymer composition may also contain appropriate amounts of other additives such as for example fillers, antioxidants, pigments, antistatic agents and polymers depending on the specific use.

The production processes of LLDPE and LDPE are summarised in "Handbook of Polyethylene" by Andrew Peacock (2000; Dekker; ISBN 0824795466) at pages 43-66. The catalysts can be divided in three different subclasses including Ziegler Natta catalysts, Phillips catalysts and single site catalysts. The latter class is a family of different classes of compounds, metallocene catalysts being one of them. As elucidated at pages 53-54 of said Handbook a Ziegler- Natta catalysed polymer is obtained via the interaction of an organometallic compound or hydride of a Group l-lll metal with a derivative of a Group IV-VIII transition metal. An example of a (modified) Ziegler-Natta catalyst is a catalyst based on titanium tetra chloride and the organometallic compound

triethylaluminium. A difference between metallocene catalysts and Ziegler Natta catalysts is the distribution of active sites. Ziegler Natta catalysts are

heterogeneous and have many active sites. Consequently polymers produced with these different catalysts will be different regarding for example the molecular weight distribution and the comonomer distribution. The various processes may be divided into solution polymerisation processes employing homogeneous (soluble) catalysts and processes employing supported (heterogeneous) catalysts. The latter processes include both slurry and gas phase processes. According to a preferred embodiment of the present invention the LLDPE has been obtained with gas phase polymerisation in the presence of a metallocene catalyst or a Ziegler Natta catalyst.

Although the invention has been described in detail for purposes of illustration, it is understood that such detail is solely for that purpose and variations can be made therein by those skilled in the art without departing from the spirit and scope of the invention as defined in the claims.

It is further noted that the invention relates to all possible combinations of features described herein, preferred in particular are those combinations of features that are present in the claims.

It is further noted that the term 'comprising' does not exclude the presence of other elements. However, it is also to be understood that a description on a product comprising certain components also discloses a product consisting of these components. Similarly, it is also to be understood that a description on a process comprising certain steps also discloses a process consisting of these steps.

The invention is now elucidated by way of the following examples, without however being limited thereto.

Example 1 /European Pharmacopeia tests

SABIC® LLDPE PCG61 18NE was used. This grade was prepared by melt- mixing an LLDPE powder having a density of 918 kg/m ³ and a melt flow rate (IS01 133, 2.16 kg/190 °C ) of 0.9 g/10 minutes.with Zn stearate (ZnSt; final concentration in the LLDPE composition 500ppm) and anti-oxidants (final concentration in the LLDPE composition l OOOppm )in a twin screw extruder. The example was repeated, but instead of ZnSt, ZnO (final concentration in the LLDPE composition 350ppm) was used. Sample 1 as referred herein is the LLDPE grade with 350ppm ZnO

Sample A as referred herein the the LLDPE grade with 500ppm Zn stearate (ZnSt).

The standard tests according to European Pharmacopeia 7.0, volume 1 , January 201 1 ; § 3.1 .3 - Polyolefines were conducted on Sample 1 (SABIC® LLDPE PCG61 18NE containing 350ppm zinc oxide) and Sample A (SABIC® LLDPE PCG61 18NE containing 500ppm zinc stearate).

Identification was done by Fourier transform infrared spectroscopy (FTIR) by attenuated total reflection (ATR). The identification of the material was done as described in European Pharmacopeia 7.0, volume 1 , January 201 1 ; § 3.1 .3 - Polyolefines.

IR absorption:

Maxima at 2920cm ^"1 , 1475cm ^"1 , 1465cm ^"1 , 1380cm ^"1 , 1 170cm ^"1 , 735cm ^"1 and 720cm ^"1 . The spectra obtained were identical to a reference of linear low density polyethylene.

The results are presented in Table 1 below: Table 1. Results of the standard test of the European Pharmacopeia on an LLDPE sample with zinc oxide (sample 1 ) and on a sample with zinc stearate (sample A).

As can be seen from the above table, Sample 1 comprising a linear low density polyethylene and an inorganic acid scavenger for example zinc oxide passes all standard tests of the European Pharmacopeia, whereas sample A comprising a linear low density polyethylene and an organic acid does not pass the test for zinc as the limit according to the specification is 1 and the value tested is 1 .1 .

Example 21 Mechanical properties and hot tack

Of sample 1 (SABIC® LLDPE PCG61 18NE containing 350ppm zinc oxide) and of sample 2 (SABIC® LDPE PCG01 having a melt flow rate of 0.75g/1 Ominutes and a density of 925 kg/m ³ , films were prepared of different thickness (50 and 10Ομιη) at a blow up ratio of 3 (BUR) using a Kuhne blow film line equipped with 35mm diameter extruder with a 120mm die and a die gap of 1 .5 mm. The machine was operated at 25 kg/h. Barrel temperature profiles were ramped from 40°C at the feed section to 200°C at the die. The properties of the films are presented in table 2.

As can be seen from Table 2, the mechanical properties of the LLDPE film containing an inorganic acid scavenger are good and in some cases even better than the properties of the LDPE film.

Furthermore, the hot tack strength of the films was also measured (according to ASTM F1921 ). The results of these measurements are presented in table 3.

Table 2. Film properties of sample 1 (SABIC® LLDPE PCG61 18NE containing 350ppm zinc oxide) and of sample 2 (SABIC® LDPE PCG01 ) without additives). Table 3. Hot tack strength

As can be seen from table 3, the composition comprising LLDPE and an inorganic acid scavenger showed an increase in hot tack strength as compared to LDPE, which makes the LLDPE composition beneficial for use in many health care applications.

Example 3. blends of LLDPE and LDPE

Granulate of SABIC® LLDPE PCG61 18NE containing 350ppm zinc oxide was mixed with granulate of SABIC® LDPE2100TN00 containing no additives in a 70/30 or 30/70 weight ratio and fed to the extruder of the Kuhne blown film line. The extruder had a 35mm barrier screw with a shearing and a mixing part, L = 24D. The blown film line had a die of 120mm, a die gap of 2.7 mm. Films of 50μιη were prepared at a blow up ratio of 2.

The properties of the blends were measured as presented in Table 1 herein and compared to a film of 50μιη with 100% SABIC® LLDPE PCG61 18NE containing 350ppm zinc oxide and are presented in Table 4 below.

Table 4. Film properties of LLDPE containing ZnO and LDPE

# = standard deviation

TD = translational direction

MD = machine direction

As can be seen from Table 4, blends of LLDPE and LDPE also have good mechanical properties. Furthermore, since this blend comprises an LDPE, which also meets the requirements of the European also the blends comply with the requirements of the European Pharmacopeia. Therefore, compositions comprising LLDPE, LDPE and an inorganic acid scavenger, for example zinc oxide are suitable for use in health care applications. Conclusion

The results as presented herein show that a composition comprising a linear low density polyethylene and an inorganic acid scavenger is suitable for use in health care applications since it has good mechanical properties and passes the

European Pharmacopeia tests.

Oxygen induction temperature (OIT) was measured according to D3895-95 at 200 degrees C on granulate of SABIC® LLDPE PCG61 18NE containing 6 ppm of ZnO and compared to the OIT of granulate of SABIC® LLDPE PCG61 18NE containing 690 ppm of ZnO.

It was found that the OIT of SABIC® LLDPE PCG61 18NE containing 6 ppm of ZnO was 9 min and that the OIT of SABIC® LLDPE PCG61 18NE containing 690 ppm of ZnO was 60 min. OIT is an indicator for how quickly a (LLD)PE degrades. The higher the OIT, the slower the degradation.

It has therefore been shown that the compositions of the invention show less degradation, i.e. are more stable than compositions not according to the invention. This is of particular importance in healthcare, where articles need to be able to withstand sterilization temperatures for a certain time and should not degrade during sterilization.