Packaging

This invention relates to packaging and materials therefor. Preferred embodiments relate to containers, such as PET bottles, which are white in colour and are arranged to block and/or restrict light from entering the container to reduce the risk of the contents of the container degrading during storage due to exposure to light.

It is known to produce containers with light protection obtained by incorporating inorganic shielding fillers into PET. For example, EP3023458A1 relates to a single-layer plastic container with light shielding, wherein the procedure to incorporate a light-shielding filler is performed by adding, to a main PET plastic base, a concentrated additive that contains a high impact polystyrene (HIPS) and/or polypropylene (PP) polymer base in which inorganic shielding fillers that contain T1O2 and Al have previously been dispersed.

Other plastic containers which address the same problem to protect their contents (e.g. UHT long-life milk) from light radiation are available in different plastic media and with different types of structures, for example: three-layer polyethylene, three-layer PET, two-layer PET or singlelayer PET.

Conventionally, plastic containers which incorporate light protection have a white-coloured surface due to the fact that one of the most widespread uses for such containers is the bottling of long-life milk (e.g. UHT milk) and/or UHT milk products. There are known solutions to the problem in which T1O2, a white pigment with a high concealing power, is combined with light absorbers that effectively reinforce the shield provided by the T1O2. However, these light absorbers necessarily darken the surface of the containers rendering an unattractive and undesirable greyish colour and this means that the concentrations that can be used in the containers and hence the threshold of their efficacy are limited. Commercially-available plastic bottles have tended to include relatively high levels of T1O2 in view of its very high light blocking ability and its whiteness. Such TiC>2-containing bottles have excellent performance including very low light transmission (e.g. very low LT% at 550nm) (i.e. high opacity) and high whiteness (e.g. high L*). However, legislation relating to the hazard classification of T1O2 has made it desirable to endeavour to reduce the amount of T1O2 in bottles. In addition, for recyclability reasons, it is desirable to reduce total levels of inorganic additives in general. However, solving such problems, especially in monolayer bottles, is challenging. In particular, whilst it is straightforward to produce highly opaque bottles, it is challenging to achieve both high opacity and high lightness. In addition, the Applicant has appreciated that, with certain formulations proposed to address the above-described problems, a further problem can become apparent, namely that the necks of blown bottles can appear less white compared to bottle walls. A significant (e.g. observable by the eye) contrast between the whiteness (or L*) of bottle necks and bottle side walls is aesthetically (and, therefore, commercially) unacceptable.

Cyclic-olefin copolymers (COCs) and polymethylpentene (PMP) have been proposed for use as opacifiers in bottles. However, Applicant has appreciated that the inclusion of such polymers in formulations for producing containers may increase the risk that a bottle will be produced with the above described unacceptable contrast between the whiteness of the bottle neck and the bottle wall.

It is an object of the present invention to address the above described problems.

According to a first aspect of the invention, there is provided a container body which comprises a base and a side wall extending from the base, wherein said container body includes a polyester and a polymer YY.

Said polyester is preferably a polyethylene terephthalate which term, in the context of the present specification, is intended to encompass co-polyethylene terephthalates. Copolyethylene terephthalates of polyethylene terephthalate may contain repeat units from at least 85 mole % terephthalic acid and at least 85 mole % of ethylene glycol. Dicarboxylic acids which can be included, along with terephthalic acid, are exemplified by phthalic acid, isophthalic acid, naphthalene-2, 6-dicarboxylic acid, cyclohexanedicarboxylic acid, cyclohexanediacetic acid, diphenyl-4, 4'-dicarboxylic acid, succinic acid, glutaric acid, adipic acid, azelaic acid and sebacic acid. Other diols which may be incorporated in the copolyethylene terephthalates, in addition to ethylene glycol, include diethylene glycol, triethylene glycol, 1 ,4-cyclohexanedimethanol, propane-1 ,3-diol, butane-1 ,4-diol, pentane-1 ,5-diol, hexane-1 ,6-diol, 3-methylpentane-2,4-diol, 2-methyl pentane-1 ,4-diol, 2,2,4-trimethylpentane- 1 ,3-diol, 2-ethylhexane-1 ,3-diol, 2, 2-diethylpropane-1 ,3-diol, hexane-1 ,3-diol, 1 ,4- di(hydroxyethoxy)-benzene, 2,2-bis-(4-hydroxycyclohexyl)-propane, 2,4-dihydroxy-1 ,1 ,3,3- tetramethyl-cyclobutane, 2,2-bis-(3-hydroxyethoxyphenyl)-propane, and 2,2-bis-(4- hydroxypropoxyphenyl)-propane. In a preferred embodiment said polyethylene terephthalate has less than 10mole%, more preferably less than 6mole% especially less than 2 mole% comonomer substitution. Preferably, said co-polyethylene terephthalate does not comprise copolyethylene terephthalate; it suitably comprises substantially a homopolymer produced by esterification or transesterification of terephthalic acid or dimethyl terephthalate and ethylene glycol to produce bis(2-hydroxyethyl) terephthalate which is then subjected to polycondensation at high temperatures in vacuum in the presence of a catalyst. Said polyester may have a Tg of less than 90°C, for example of less than 85°C. The Tg may be at least 60°C or 65°C.

The difference between the Tg of the polyester and that of said polymer YY (where said polymer has a Tg) may be at least 30°C; the difference may be less than 90°C, or less than 60°C.

As used herein the term “IV” refers to the Inherent Viscosity of the polymeric material. It may be determined on a solution of 0.5 g of polymer dissolved in 100 ml of a mixture of phenol (60% by volume) and tetrachloroethane (40% by volume).

The IV of the polyester is preferably greater than 0.5 dL/g, more preferably greater than

0.65 dL/g. Said polyester and said polymer YY are preferably not wholly miscible. Hence, a mixture comprising said polyester and said polymer YY may include observable regions of polymer YY dispersed in the polyester. Such regions may be observed by SEM. The observable regions of polymer YY may be particulate for example generally spherical. Polymer YY may be selected from a cyclic olefin copolymer (COC) and a polymethylpentene polymer (PMP).

Said COC may include a repeat unit of formula which may be optionally substituted (but is preferably not substituted).

Said COC may include a repeat unit of formula which may be optionally-substituted (but preferably is not substituted). Said COC may include at least 40 mol%, preferably at least 45 mol%, of said repeat unit of formula I. It may include less than 70 mol% or less than 65 mol% of said repeat unit of formula

Said COC may include less than 60 mol%, preferably less than 55 mol% of said repeat unit of formula II. It may include at least 30 mol% or at least 35 mol% of said repeat unit of formula II.

Said COC may have a density in the range 1000 to 1050 kg/m ³ , measured as described in ISO 1183.

Said COC may have a Melt Volume Rate (MVR), measured as described in ISO 1183 in the range 1 to 50 cm ³ /10mins. In some embodiments, the MVR may be less than 25 cm ³ /10mins.

Said COC may have a Tensile Modulus (1 mm/min), measured as described in ISO 527-2/1 A of greater than 2700 MPa. It may be in the range 2750 to 3400 MPa.

Said COC may have a glass transition temperature (Tg) (10°C/min) measured as described in ISO 11357-1 , -2, -3 of greater than 100°C, preferably greater than 130°C. Said Tg may be less than 190°C. Said Tg may be in the range 130°C to 185°C.

Said COC may have a DTUL @ 0.45 MPa, measured as described in ISO 75-1 , -2 of greater than 100°C, preferably greater than 120°C. The DTUL may be less than 190°C. Said DTUL may be in the range 118 to 180°C.

A said PMP may refer to a thermoplastic homopolymer or copolymer which suitably is a 4- methyl-1-pentene based polyolefin having a repeat unit formula:

Integer n is suitably high enough on a number average basis (e.g. being at least 30) for the polymer to have a number average molecular weight higher than the number average molecular weight of an oligomer. The monomeric unit (ie the unit above excluding integer n) can homopolymerize or copolymerize, such as with an alkylene moiety. Suitable examples of comonomers include ethylene, propylene, 1 -butene, 1-pentene, 1 -hexene, 1 -heptane, 1- octene, nonene and 1-decene. PMP may include copoylmers with a decene (eg decene, hexadecene, octadecene, especially with 1-decene, 1-hexadecene, 1-octadecene) or combinations thereof.

Typical PMPs may have a melting point of about 240°C and are nearly transparent with a low specific gravity of about 0.83 g/cm . The reported haze is less than 1% with a transmittance of more than 90%. Typical PMPs have a refractive index of 1 .46.

Preferred PMPs have a very low surface tension for example of less than 30mN/m or less than 25mN/m.

PMP is available from Mitsui Chemicals America, Inc. PMP grades RT-31 and/or RT-18 may be preferred.

Said PMP may have a MFR measured by the MCI method with an applied force of 5kgf at 260°C of 15-30 g/10min, preferably 20-27 g/10mins; and/or

Said PMP may have a melting point measured by DSC according to ASTM D3418 of at least 229°C, preferably in the range 230 - 235°C; and/or

Said PMP may have a Vicat softening temperature, measured by ASTM-D1525 (injection moulded specimen (2 mm thick x 2pcs), heat speed: 50°C/hour with an applied load of 10N), of 165 to 170°C, preferably of 167 to 169°C; and/or

Said PMP may have a heat distortion temperature, measured by ASTM-D648 (injection moulded specimen (0.25 inch thick), heat speed of 120°C/hour and applied stress of 0.45MPa) of 127°C; and/or

Said PMP may have a flexural modulus measured according to ASTM-D790 on an injection moulded specimen (3.2 mm thick), crosshead speed 1 .3 mm/in, span length 51 mm) of 1425 to 1475MPa, preferably about 1450MPa; and/or a flexural strength, measured by ASTM-D7 90 and the same conditions, of 34 to 39 MPa, preferably about 36 MPa; and/or

Said PMP may have an Izod impact strength, measured according to ASTM-D256, on an injection moulded specimen (machined notch) of 21 to 27 J/m, preferably about 24 J/m; and/or

Said PMP may have a Rockwell Hardness measured according to ASTM-D785 on an injection moulded specimen, with measurement on the R scale, of 75 to 90, preferably 80 to 85; and/or Said PMP may have a refractive index measured on an injection moulded specimen (2 mm thick) at a wavelength of 589 nm, according to ASTM-D542, of 1 .4 to 1 .5, for example 1 .462.

A ratio (A) defined as the weight of polyester divided by the weight of polymer YY in the container body may be in the range 8 to 32, preferably in the range 15 to 30, more preferably in the range 15 to 25.

A ratio (B) defined as the weight of polyester divided by the weight of polymer YY in a layer of the container body may be in the range 8 to 32, preferably in the range 15 to 30, more preferably in the range 15 to 25. In preferred embodiments, said container body is defined by a single layer, in which case, said sidewall of the container body may consist of a single layer and ratio (B) suitably defines the weight of polyester divided by the weight of polymer YY in said single layer of the container body.

Said container body may include 1 to 10 wt% of polymer YY, preferably 3 to 8 wt% of polymer YY, more preferably 3 to 6wt% of polymer YY. Said container body may include 85 to 97 wt% of polyester. Said container body may include 88 to 96 wt% of polyester, 3 to 8 wt% of polymer YY and 1 to 7 wt% of other ingredients. In one preferred embodiment, said container body includes 88.0 to 94.0 wt% of polyester, 3.0 to 6.0wt% of polymer YY and 1.0 to 7.0 wt% of other ingredients.

A single layer of said container body may include 1 to 10 wt% of polymer YY, preferably 3 to 8 wt% of polymer YY, more preferably 3 to 6wt% of polymer YY. Said single layer of said container body may include 85 to 97 wt% of polyester. Said single layer may include 88 to 96 wt% of polyester, 3 to 8 wt% of polymer YY and 1 to 7 wt% of other ingredients. In one preferred embodiment, said single layer includes 88.0 to 94.0 wt% of polyester, 3.0 to 6.0wt% of polymer YY and 1 .0 to 7.0 wt% of other ingredients.

The sum of the wt% of thermoplastic polymers (eg polyester and polymer(s) YY) in said container body may be at least 88 wt%, preferably at least 92 wt%, more preferably at least 94 wt%. The sum may be less than 99wt% or less than 97wt%.

Said container body may include a first light shielding pigment. Such a pigment may interact with incident light by primarily diffracting light and optionally scattering and/or absorbing. Diffraction occurs as a result of a difference in refractive index between the light shielding pigment and the polyester or polymer YY. Light shielding pigments may solely diffract, as in the case of titanium dioxide (TiC>2), or they may both scatter and absorb, as in the case of black iron oxide (PBIk 11). Some examples of light shielding pigments include titanium dioxide (T1O2), ultramarine blue (PB 29), metal oxide particles such as red iron oxide (PR 101), black iron oxide (PBIk 11), chromium green-black hematite (PG 17), cobalt aluminate (PB 28), aluminium trihydrate (AI(OH)3), barium sulfate (BaS04), zinc sulphide (ZnS), zinc oxide, metal flake (eg aluminium or bronze flakes), calcium carbonate and mica.

Said first light shielding pigment is preferably zinc sulphide (ZnS). Said first light shielding pigment preferably includes at least 95wt%, especially at least 99wt% zinc sulphide (ZnS).

Said container body may include less than 8 wt%, preferably less than 6 wt%, more preferably less than 5 wt%, especially no more than 4.5 wt% of said first light shielding pigment. Said container body may include at least 1 wt% or at least 2 wt% of said first light shielding pigment. Said container body may include 2 to 5 wt% of said first light shielding pigment.

Said container body may include less than 2 wt%, preferably less than 1.5 wt%, more preferably no greater than 1.0wt% of titanium dioxide. Said container body may include 0 to 2 wt%, preferably 0 to 1 5wt%, of titanium dioxide. In one embodiment, said container body may include 0wt% of titanium dioxide

A single layer of said container body may include less than 8 wt%, preferably less than 6 wt%, more preferably less than 5 wt%, especially no more than 4.5 wt% of said first light shielding pigment. A single layer of said container body may include at least 1 wt% or at least 2 wt% of said first light shielding pigment. A single layer of said container body may include 2 to 5 wt% of said first light shielding pigment.

A single layer of said container body may include less than 8 wt%, preferably less than 6 wt%, more preferably less than 5 wt%, especially no more than 4.5 wt% of zinc sulphide. A single layer of said container body may include at least 1 wt% or at least 2 wt% of said zinc sulphide. A single layer of said container body may include 2 to 5 wt% of said zinc sulphide.

Said container body may include a second light shielding pigment. Said second light shielding pigment may be selected from titanium dioxide (T1O2), ultramarine blue (PB 29), metal oxide particles such as red iron oxide (PR 101), black iron oxide (PBIk 11), chromium green-black hematite (PG 17), cobalt aluminate (PB 28), aluminium trihydrate (AI(OH)3), barium sulfate (BaS04), zinc sulphide (ZnS), zinc oxide, metal flake (eg aluminium or bronze flakes), calcium carbonate and mica. Said first and second light shielding pigments are preferably different and/or do not include all of the same elements.

Said second light shielding pigment is preferably particulate metal, for example a metal flake, for example particulate aluminium or aluminium flake. Said second light shielding pigment preferably includes at least 95wt%, especially at least 99wt% aluminium. Said container body may include less than 1.0 wt%, preferably less than 0.50 wt%, more preferably less than 0.050 wt% of said second light shielding pigment. Said container body may include at least 0.001 wt% or at least 0.025 wt% of said second light shielding pigment. Said container body may include 0.025 to 0.50 wt% of said second light shielding pigment.

The sum of the wt% of light shielding pigments (eg said first, said second and/or any other light shielding pigments) in said container body may be less than 8wt%, preferably less than 6wt%, especially less than 5wt%. The sum may be at least 1wt% or at least 3wt%. The sum may be in the range 2.0 to 4.0wt%.

In one embodiment, said container body includes 88-93wt% of said polyester (eg PET), 1- 6wt% zinc sulphide, 3-7wt% of said polymer YY (eg COC), and 0.01 to 0.2wt% of particulate aluminium (eg flake).

In a preferred embodiment, said container body includes 88-93wt% polyester (eg PET), 2- 5wt% zinc sulphide, 4-7wt% of polymer YY (eg COC), and 0.01 to 0.10wtt% of particulate aluminium (eg flake). As described, said container body comprises said polyester. Said container body preferably comprises polyester as the major thermoplastic polymer in the container body. Polyester (especially PET) preferably makes up at least 75wt%, preferably at least 85wt%, of the total wt% of thermoplastic polymers in the container body. Said container body may define a receptacle for example a bottle, suitably excluding any closure (e.g. cap) thereof. Said container body may include a ridged, for example screw- threaded, neck arranged to cooperate with a closure, for example a screw-threaded closure.

Said container body and/or a sidewall thereof preferably includes only one layer of material which suitably defines the container body (excluding any closure for the container body). Thus, said container body and/or a sidewall thereof preferably do not include any laminated region or multi-layered region.

Said container body preferably comprises and/or is defined by a mixture, for example a substantially homogenous mixture, of said polyester, said polymer YY and, when provided, said first light shielding pigment and said second light shielding pigment.

In one embodiment, there is provided a container body which comprises a base, a side wall extending from the base and a neck portion arranged to engage a closure for the container body, wherein said container body includes a polymer YY (eg cyclic olefin copolymer (COC) or polymethylpentene (PMP)) and polyester (eg PET), wherein the side wall of the container body has an L* of at least 90 and the neck portion has an L* of at least 84.

The L* of the container body may be assessed using a reflectance technique (suitably so the thickness of any sample is not generally relevant) as described in Test 2 hereinafter.

The L* of the neck portion of the container body is suitably taken to be the L* of the side wall of a preform from which the container body is blown. It may be assessed as described in Test 1 hereinafter.

To reduce the risk the lightness of the side wall is too light compared to the lightness of the neck (which may lead to the container body being aesthetically unacceptable due to the lightness contrast between side wall and neck), the difference between the L* of the side wall and preform is suitably less than a predetermined level as determined by Applicant. The difference is suitably less than 12, suitably less than 10, preferably less than 9, especially 8 or less.

The L* of the side wall of the container body may be at least 90 or at least 92. The L* may be less than 98, less than 96 or less than 94. The L* may be in the range 90 to 95.

The L* of the neck portion may be at least 83, preferably at least 84, more preferably at least 85. The L* of the neck portion may be less than 90 or 88. The L* of the neck portion may be in the range 83-89 or 83-87.

A first ratio defined as the L* of the side wall of the container body divided by the L* of the neck portion may be at least 1 .03 or at least 1 .05; it may be less than 1 .15 or less than 1 .10.

The difference between the b* of the side wall of the container body and the neck portion of the container body may be greater than 1 .0. It may be less than 3.0.

The difference between the b* of the side wall of the container body and the neck portion of the container body may be less than 1 .0.

Said container body preferably has a light transmission (LT%) at 550nm as described in Test 3 of less than 1 .0%, preferably less than 0.5%, more preferably less than 0.2%.

Said neck portion is suitably a portion of the container body which includes said polyester (eg PET) which is substantially, preferably entirely, unstretched (eg in a blow molding process) and/or is suitably substantially identical to the neck portion in a preform from which the container body is blown.

Said neck portion preferably extends from an open end of the container body, suitably inwards. It may extend a distance of at least 1cm or at least 1 5cm. A second ratio, defined as the total length of the container body (suitably measured from the base to the neck portion) divided by the length of the neck portion may be at least 5 or at least 10.

Said neck portion preferably includes grooves, for example, screw-threads for releasably engaging a closure.

Said container body may have volume in the range 0.1 to 5 litres or in the range 0.2 to 1.5 litres.

In an embodiment AA, said polyester (eg PET) and said polymer YY is COC. In said embodiment AA, a ratio ( A) defined as the weight of polyester (eg PET) divided by the weight of COC in the container body may be in the range 8 to 32, preferably in the range 15 to 30, more preferably in the range 15 to 25.

In said embodiment AA, a ratio (B) defined as the weight of polyester (eg PET) divided by the weight of COC in a layer of the container body may be in the range 8 to 32, preferably in the range 15 to 30, more preferably in the range 15 to 25. In embodiment AA, said container body is defined by a single layer, in which case, said sidewall of the container body may consist of a single layer and ratio (B) suitably defines the weight of polyester (eg PET) divided by the weight of COC in said single layer of the container body.

In said embodiment AA, said container body may include 1 to 10 wt% of COC, preferably 3 to 8 wt% of COC, more preferably 3 to 6wt% of COC. Said container body may include 85 to 97 wt% of polyester (eg PET). Said container body may include 88 to 96 wt% of polyester (eg PET), 3 to 8 wt% of COC and 1 to 7 wt% of other ingredients. In one preferred embodiment, said container body includes 88.0 to 94.0 wt% of polyester (eg PET), 3.0 to 6.0wt% of COC and 1 .0 to 7.0 wt% of other ingredients.

In said embodiment AA, a single layer of said container body may include 1 to 10 wt% of COC, preferably 3 to 8 wt% of COC, more preferably 3 to 6wt% of COC. Said single layer of said container body may include 85 to 97 wt% of polyester (eg PET). Said single layer may include 88 to 96 wt% of polyester (eg PET), 3 to 8 wt% of COC and 1 to 7 wt% of other ingredients. In one preferred embodiment, said single layer includes 88.0 to 94.0 wt% of polyester (eg PET), 3.0 to 6.0wt% of COC and 1 .0 to 7.0 wt% of other ingredients. In said embodiment AA, the difference between the Tg of the polyester (eg PET) and that of said COC may be at least 30°C; the difference may be less than 90°C, or less than 60°C. In said embodiment AA, said polyester (eg PET) and said COC are preferably not wholly miscible. Hence, a mixture comprising said polyester (eg PET) and COC may include observable regions of COC dispersed in the polyester. Such regions may be observed by SEM. The observable regions of COC may be particulate for example generally spherical. In said embodiment AA, the sum of the wt% of thermoplastic polymers (eg polyester(s)) and COC(s) in said container body may be at least 88 wt%, preferably at least 92 wt%, more preferably at least 94 wt%. The sum may be less than 99wt% or less than 97wt.

In said embodiment AA, said polyester is PET and said polymer YY is PMP. In said embodiment AA, a ratio ( A) defined as the weight of polyester (eg PET) divided by the weight of PMP in the container body may be in the range 8 to 32, preferably in the range 15 to 30, more preferably in the range 15 to 25.

In said embodiment AA, a ratio (B) defined as the weight of polyester (eg PET) divided by the weight of PMP in a layer of the container body may be in the range 8 to 32, preferably in the range 15 to 30, more preferably in the range 15 to 25. In embodiment AA, said container body is defined by a single layer, in which case, said sidewall of the container body may consist of a single layer and ratio (B) suitably defines the weight of polyester (eg PET) divided by the weight of PMP in said single layer of the container body.

In said embodiment AA, said container body may include 1 to 10 wt% of PMP, preferably 3 to 8 wt% of PMP, more preferably 3 to 6wt% of PMP. Said container body may include 85 to 97 wt% of polyester (eg PET). Said container body may include 88 to 96 wt% of polyester (eg PET), 3 to 8 wt% of PMP and 1 to 7 wt% of other ingredients. In one preferred embodiment, said container body includes 88.0 to 94.0 wt% of polyester (eg PET), 3.0 to 6.0wt% of PMP and 1 .0 to 7.0 wt% of other ingredients.

In said embodiment AA, a single layer of said container body may include 1 to 10 wt% of PMP, preferably 3 to 8 wt% of PMP, more preferably 3 to 6wt% of PMP. Said single layer of said container body may include 85 to 97 wt% of polyester (eg PET). Said single layer may include 88 to 96 wt% of polyester (eg PET), 3 to 8 wt% of PMP and 1 to 7 wt% of other ingredients. In one preferred embodiment, said single layer includes 88.0 to 94.0 wt% of polyester (eg PET), 3.0 to 6.0wt% of PMP and 1 .0 to 7.0 wt% of other ingredients. In said embodiment AA, said polyester (eg PET) and said PMP are preferably not wholly miscible. Hence, a mixture comprising said polyester (eg PET) and COC may include observable regions of PMP dispersed in the polyester. Such regions may be observed by SEM. The observable regions of COC may be particulate for example generally spherical.

In said embodiment AA, the sum of the wt% of thermoplastic polymers (eg polyester(s)) and PMP(s) in said container body may be at least 88 wt%, preferably at least 92 wt%, more preferably at least 94 wt%. The sum may be less than 99wt% or less than 97wt.

In a preferred embodiment, said container body comprises a polyester as the major thermoplastic polymer in the container body. Polyester (especially PET) preferably makes up at least 75wt%, preferably at least 85wt%, of the total wt% of thermoplastic polymers in the container body.

In one embodiment, said container body includes 88-93wt% polyester (eg PET), 1-6wt% zinc sulphide, 3-7wt% of COC, 0.01 to 0.2wt% of particulate aluminium (eg flake).

In a preferred embodiment, said container body includes 88-93wt% polyester (eg PET), 2- 5wt% zinc sulphide, 4-7wt% of COC, 0.01 to 0.10wtt% of particulate aluminium (eg flake).

In another embodiment, said container body includes 88-93wt% polyester (eg PET), 1-6wt% zinc sulphide, 3-7wt% of PMP, 0.01 to 0.2wt% of particulate aluminium (eg flake).

In said another preferred embodiment, said container body includes 88-93wt% polyester (eg PET), 2-5wt% zinc sulphide, 4-7wt% of PMP, 0.01 to 0.10wtt% of particulate aluminium (eg flake).

Said container body preferably comprises and/or is defined by a mixture, for example a substantially homogenous mixture, of said polyester and said cyclic olefin copolymer (COC) and, when provided, said first light shielding pigment and said second light shielding pigment.

Said container body may comprise virgin polyester or recycled polyester, for example PET.

Said container body is preferably part of a beverage container. It may have a volume of no more than 5 litres, for example no more than 2 litres or no more than 1 litre.

Said container body for example a sidewall thereof, may have a thickness of at least 100 microns or at least 200 microns. The thickness may be less than 500 microns or less than 400 microns or less than 398 microns. The thickness may be in the range 102 to 398 microns and may comprise PET.

The neck of said container body may have a maximum internal diameter of at least 10mm or at least 15mm. The maximum internal diameter may be less than 70mm. The maximum internal diameter may be in the range 11 to 40mm. The footprint of the bottle (when stood on its base) may have an area in the range 1000 to 10000 mm ³ . The ratio defined as the maximum internal diameter of the neck divided by the area of the footprint of the bottle may be in the range 0.001 to 0.04.

The invention extends, in a second aspect, to a container comprising a container body according to the first aspect, wherein a closure is secured, for example releasably secured, to the container body.

The container may include a beverage. It may include at least 100ml or at least 500ml of beverage. The beverage may include at least 90wt% water. The beverage may include at least 0.1 wt% for example at least 1wt% fat. It may include less than 10wt% fat. Said beverage is preferably a milk, for example animal milk.

According to a third aspect of the invention there is provided a preform for making a container body, for example according to the first aspect or second aspect, the preform comprising:

(i) a polyester;

(ii) a polymer YY (eg cyclic olefin copolymer (COC) or polymethylpentene polymer (PMP)).

The L* of the preform may be at least 83, preferably at least 84, more preferably at least 85. The L* of the preform may be less than 90 or 88. The L* of the preform may be in the range 83-89 or 83-87.

Said preform preferably includes polyester (eg PET) which is substantially, preferably entirely, unstretched.

A neck portion of said preform preferably includes grooves, for example, screw-threads for releasably engaging a closure.

Polyester may be as described in the first aspect. It is preferably PET.

Polymer YY may be as described in the first aspect. It is preferably COC or PMP. A ratio (A) defined as the weight of polyester divided by the weight of polymer YY (eg COC or PMP) in the preform may be in the range 8 to 32, preferably in the range 15 to 30, more preferably in the range 15 to 25.

Said preform may include 1 to 10 wt% of polymer YY (eg COC or PMP), preferably 3 to 8 wt% of polymer YY (eg COC or PMP), more preferably 3 to 6wt% of polymer YY (eg COC or PMP). Said preform may include 85 to 97 wt% of polyester. Said preform may include 88 to 96 wt% of polyester, 3 to 8 wt% of polymer YY (eg COC or PMP) and 1 to 7 wt% of other ingredients. In one preferred embodiment, said preform includes 88.0 to 94.0 wt% of polyester, 3.0 to 6.0wt% of polymer YY (eg COC or PMP) and 1 .0 to 7.0 wt% of other ingredients.

A single layer of said preform may include 1 to 10 wt% of polymer YY (eg COC or PMP), preferably 3 to 8 wt% of polymer YY (eg COC or PMP), more preferably 3 to 6wt% of polymer

YY (eg COC or PMP). Said single layer of said preform may include 85 to 97 wt% of polyester. Said single layer may include 88 to 96 wt% of polyester, 3 to 8 wt% of polymer YY (eg COC or PMP) and 1 to 7 wt% of other ingredients. In one preferred embodiment, said single layer includes 88.0 to 94.0 wt% of polyester, 3.0 to 6.0wt% of polymer YY (eg COC or PMP) and 1 .0 to 7.0 wt% of other ingredients.

Said COC may be as described in the first aspect.

Said PMP may be as described in the first aspect.

In said preform, said polyester and said polymer YY (eg COC or PMP) are preferably not wholly miscible. Hence, a mixture comprising said polyester and polymer YY (eg COC or PMP) may include observable regions of polymer YY (eg COC or PMP) dispersed in the polyester. Such regions may be observed by SEM. The observable regions of COC may be particulate for example generally spherical.

The sum of the wt% of thermoplastic polymers (eg polyester(s)), COC(s) and PMPs in said preform may be at least 88 wt%, preferably at least 92 wt%, more preferably at least 94 wt%. The sum may be less than 99wt% or less than 97wt%.

Said preform preferably comprises a polyester as the major thermoplastic polymer in the preform. Polyester (especially PET) preferably makes up at least 75wt%, preferably at least 85wt%, of the total wt% of thermoplastic polymers in the preform. Said preform and/or a sidewall thereof preferably includes only one layer of material which suitably defines the preform. Thus, said preform and/or a sidewall thereof preferably do not include any laminated region or multi-layered region.

Said preform may include a first light shielding pigment. Such a pigment may be as described in the first aspect.

Said first light shielding pigment is preferably zinc sulphide (ZnS). Said first light shielding pigment preferably includes at least 95wt%, especially at least 99wt% zinc sulphide (ZnS).

Said preform may include a second light shielding pigment. Such a pigment may be as described in the first aspect.

Said second light shielding pigment is preferably particulate metal, for example a metal flake, for example particulate aluminium or aluminium flake. Said second light shielding pigment preferably includes at least 95wt%, especially at least 99wt% aluminium.

The sum of the wt% of light shielding pigments (eg said first, said second and/or any other light shielding pigments) in said preform may be less than 8wt%, preferably less than 6wt%, especially less than 5wt%. The sum may be at least 1wt% or at least 3wt%. The sum may be in the range 2.0 to 5.0wt%.

Said preform may include less than 2 wt%, preferably less than 1.5 wt%, more preferably no greater than 1.0wt% of titanium dioxide. Said preform may include 0 to 2 wt%, preferably 0 to 1.5wt%, of titanium dioxide. In one embodiment, said preform may include 0wt% of titanium dioxide.

In one embodiment, said preform includes 88-93wt% polyester (eg PET), 1-6wt% zinc sulphide, 3-7wt% of COC, 0.01 to 0.2wt% of particulate aluminium (eg flake).

In a preferred embodiment, said preform includes 88-93wt% polyester (eg PET), 2-5wt% zinc sulphide, 4-7wt% of COC, 0.01 to 0.10wtt% of particulate aluminium (eg flake).

In another embodiment, said preform includes 88-93wt% polyester (eg PET), 1-6wt% zinc sulphide, 3-7wt% of PMP, 0.01 to 0.2wt% of particulate aluminium (eg flake).

In another preferred embodiment, said preform includes 88-93wt% polyester (eg PET), 2-5wt% zinc sulphide, 4-7wt% of PMP, 0.01 to 0.10wtt% of particulate aluminium (eg flake). Said preform for example a sidewall thereof, may have a thickness of at least 1 mm, at least 2mm or at least 3mm. The thickness may be less than 5mm.

The neck of said preform may have a maximum internal diameter of at least 10mm or at least 15mm. The maximum internal diameter may be less than 70mm. The maximum internal diameter may be in the range 11 to 40mm.

According to a fourth aspect of the invention, there is provided a formulation for use in a method of making a preform according to the third aspect, the formulation comprising a polymer YY (eg cyclic olefin copolymer (COC) or polymethylpentene polymer (PMP)) which is suitably as described in the first aspect.

Said formulation may include a first light shielding pigment as described in the first aspect. Said first light shielding pigment is preferably zinc sulphide. .Said formulation may include at least 10wt%, preferably at least 15wt%, more preferably at least 20wt%, especially at least 25wt% of said first light shielding pigment. Said formulation may include less than 50wt%, preferably less than 45wt%, more preferably less than 42wt%, of said first light shielding pigment.

Said formulation may include a second light shielding pigment as described in the first aspect. Said second light shielding pigment is preferably particulate metal, for example a metal flake, for example particulate aluminium or aluminium flake. Said second light shielding pigment preferably includes at least 95wt%, especially at least 99wt% aluminium. Said formulation may include at least 0.05wt%, preferably at least 0.1 wt%, more preferably at least 0.15wt%, of said second light shielding pigment. Said formulation may include less than 1wt%, preferably less than 0.50wt%, more preferably less than 0.45wt%, of said second light shielding pigment.

Said formulation preferably includes less than 20wt%, preferably less than 15wt%, more preferably less than 12wt% titanium dioxide.

Said formulation preferably includes less than 5wt%, preferably 0wt% of polyester, for example PET.

Said formulation may include 40-70wt% of polymer YY (eg COC or PMP), 20-50wt% of said first light shielding pigment, 0.05-1 wt% of said second light shielding pigment, and 0-15wt% of titanium dioxide. Said formulation may include 45-65wt% of polymer YY (eg COC or PMP), 25-45wt% of said first light shielding pigment, 0.10-0.50wt% of said second light shielding pigment, and 0-11wt% of titanium dioxide.

Said formulation may include 55-64wt% of polymer YY (eg COC or PMP), 25-45wt% of said first light shielding pigment, 0.10-0.50wt% of said second light shielding pigment, and 0-11wt% of titanium dioxide.

Said formulation may include 55-64wt% polymer YY (eg COC or PMP), 30-45wt% of said first light shielding pigment, 0.10-0.50wt% of said second light shielding pigment, and less than 1wt% (preferably 0wt%) of titanium dioxide.

Said formulation is preferably in the form of pellets.

According to a fifth aspect of the invention, there is provided a method of making a container body of the first aspect, the method comprising:

(i) selecting a preform according to the third aspect;

(ii) stretch blow moulding the preform to produce the container body of the first and/or second aspect.

Preferably, during said stretch blowing moulding the preform is not heated to a temperature which is greater than the Tg of the polymer YY (eg COC). Said preform is preferably stretch blow moulded at a temperature which is less than the Tg of the polymer YY (eg COC). Preferably, during said stretch blowing moulding the preform is not heated to a temperature which is greater than 130°C, or greater than 125°C. Said preform is preferably stretch blow moulded at a temperature which is less than 130°C, preferably less than 125°C.

The method may comprise selecting a formulation according to the fourth aspect and contacting said formulation with polyester as described according to the first aspect. The method may comprise contacting 5 to 15wt% of said formulation with 85 to 95wt% of polyester. The method may comprise contacting 7 to 12wt% of said formulation with 88 to 93wt% of polyester.

According to a sixth aspect of the invention, there is provided a method of making a formulation according to the fifth aspect, the method comprising contacting said polymer YY (eg COC or PMP), with said first light shielding pigment and/or other ingredients in the formulation. The method may comprise mixing said polymer YY (eg COC or PMP), with said first light shielding pigment and/or other ingredients. The method may comprise extruding said polymer YY (eg COC or PMP), with said first light shielding pigment and/or other ingredients in the formulation. An extrudate may be formed into pellets which may comprise masterbatch pellets.

Any feature of any aspect of any invention or embodiment described herein may be combined with any feature of any aspect of any other invention or embodiment described herein mutatis mutandis.

Specific embodiments of the invention will now be described, by way of example, with reference to the accompanying drawings, in which:

Figure 1 is a cross-section through a preform;

Figure 2 shows the preform of Figure 1 superimposed on a bottle blown from the preform to illustrate that a neck of the preform is unchanged on blowing to produce a bottle;

Figures 3 and 4 are graphs of light transmission v. wavelength for bottles produced.

The following materials are referred to hereinafter: PET-X - refers to a proprietary bottle grade PET (Lighter C93 from Equipolymers, with an Intrinsic Viscosity (IV) of 0.80 +/- 0.02).

Topas 6013 M-07 - Cyclic olefin copolymer (COC) obtained from Topas Advanced Polymers. It has the following properties, assessed using the standards referred to:

As an alternative to the aforementioned material, Topas 5013S-04 may be used.

PMP (TPX) - refers to polymethylpentene polymer (PMP) sold as TPX RT18 by Mitsui.

Aluminium paste - refers to STAPA WM Chromal Aluminium flake comprising 80wt% +/- 2wt% aluminium pigment and 20wt% +/- 2 wt% medical white oil and other additives. 98 wt% of the particles can pass though a 45 micron sieve. The D10 is approximately 4microns; the D50 approximately 13 microns; and the D90 approximately 28 microns. Tioxide TR28 - a surface treated fine crystal rutile titanium dioxide obtained from Huntsman.

Zinc sulphide - SACHTOLITH HD-S supplied by Venator.

Referring to Figure 1 , a preform 2 for a blow-molded PET bottle 4 (Figure 2) includes a body 6 which is arranged to expand when the preform 2 is heated in a bottle mold. Above the body 6 is a ring 8 which is generally held by a machine (not shown) during liquid filling of the blow- molded bottle. Above the ring 8 is a cap region 10 with grooves arranged to cooperate with a bottle cap for releasably closing the bottle. Neck region 12 is a portion of the preform 2 which includes cap region 10 and does not expand during blow molding of the preform to produce the bottle. Thus, as illustrated by comparing Figures 1 and 2, the neck region 12 is substantially the same size and shape in both the preform and blow-molded bottle. Figure 2 includes annotated typical preform/bottle dimensions in mm.

The following tests are referred to herein:

Test 1 - L* a* b* colour space assessment of preforms Preform colour is measured using a Minolta CM2600d spectrophotometer in reflectance mode using D65 illuminant. A preform is positioned on a metal frame (with the main elongate axis of the preform extending substantially horizontally. This allows the spectrophotometer to be positioned in contact with the preform wall at the point of the spectrophotometer aperture. L*, a* and b* values are recorded.

Test 2 - L* a* b* colour space assessment of blow-molded bottle

A small (60mm x 60mm) square section is cut from a bottle wall. This section is placed on the holder of a Minolta CM3600A spectrophotometer, with the outer surface of the bottle section towards the instrument aperture. The Large Area View (LAV) aperture is used, and the colour of the sample is measured in reflectance mode using D65 illuminant. L*,a* and b* values are recorded.

Test 3 - Measurement of light transmission of blow-molded bottle

Light transmission of each bottle is assessed on a cut section from the bottle wall, using a Shimadzu UV Visible Spectrophotometer with an integrating sphere, across the wavelength range 300 - 700nm. Example 1 - General procedure for producing preforms

Preforms are manufactured in a Husky GL160 injection moulder machine, with a two cavity mould installed. PET is weighed and premixed manually with the COC or PMP and any other additives at the required percentages and the mixture manually added into a hopper installed above the feed throat of the machine. A standard PET injection moulding process is employed to produce preforms.

Example 2 - General procedure for producing bottles from preforms

Preforms are stretch blow moulded using a Sidel SB01 blow moulding machine into 1 litre cylindrical bottles.

Example 3 - General procedure for preparing masterbatch formulations

A premix is prepared where polymer raw materials are weighed and manually mixed together with some of the other materials, aluminium paste and zinc sulphide. The extrusion line is a ZE25UTXi 50D twin screw extruder with a main feeder and a side feeder. The premix is introduced into the extruder via the main feeder and the titanium dioxide (if applicable) is introduced via the side feeder. The extrusion process is a PET process. The strands are cooled down in a water bath and pelletized in a standard pelletizer.

Examples 4 to 7- Preparation of masterbatch formulations Following the general procedure referred to in Example 3, a range of masterbatch formulations were prepared as described below. Examples 8 to 11 - Preparation of preforms

The masterbatch formulations of Examples 4 to 7 were used to produce preforms at a let- down-ratio (LDR) of 9%. More particularly, 91wt% of PET-X was compounded with 9wt% of each of the formulations and preforms manufactured in a Husky GL160 injection moulder machine, with a two cavity mould installed.

The preforms had the compositions detailed below.

Examples 12 to 15 - Production and assessment of bottles

Following the procedure referred to in Example 2, the preforms of Examples 8 to 11 were blown into bottles and assessed as described in Tests 2 and 3. Results were as follows: LT% Transmission data for the bottles of Examples 12 and 13 is provided in figure 3 and for Examples 14 and 15 is provided in Figure 4 from which it will be noted that in all cases the light transmission in both cases is very low. The results show that the bottles produced have excellent opacity and whiteness. In addition, the neck portions of the bottles were found to be sufficiently similar in colour to the body of the bottle to be aesthetically acceptable - ie to the naked eye, any differences in colour as between the neck and body of the bottle were not significant enough to lessen the perceived aesthetic acceptability of the bottle.

The invention is not restricted to the details of the foregoing embodiment(s). The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.