WO2025214761A1

WO2025214761A1 - Barrier laminate

Info

Publication number: WO2025214761A1
Application number: PCT/EP2025/058217
Authority: WO
Inventors: Christopher David ELLINGFORD; Maria Fernanda Jimenez Solomon
Original assignee: Unilever Global IP Ltd; Unilever IP Holdings BV; Conopco Inc
Current assignee: Unilever Global IP Ltd; Unilever IP Holdings BV; Conopco Inc
Priority date: 2024-04-08
Filing date: 2025-03-26
Publication date: 2025-10-16
Anticipated expiration: 2026-10-08

Abstract

A flexible barrier laminate comprising a layer comprising polyhydroxyalkanoate (PHA), particles, present in the PHA layer, wherein the particles are present in an amount of from 0.1 to 50 wt%, wherein the particulate material is selected from the group consisting of lignin, talc, olive stone powder, wine plastics filler, vine shoot powder, clay, graphene, graphene oxide and mixtures thereof, and a cellulose fiber-based layer.

Description

BARRIER LAMINATE

The present invention relates to a paper-based barrier laminate comprising a polyhydroxyalkanoate and to a process to manufacture the same. It further relates to a packaging product prepared from such a laminate. The invention furthermore relates to the use of particles in paper- and PHA-based barrier laminate to enhance UV barrier properties.

Background

Consumer products in the area of personal care, detergents or food, typically are packaged using a packaging product such as a wrapper, a sachet or a bag which contains such a consumer product. Traditional packaging products comprised petroleum-sourced barrier layers, such as polyethylene, polypropylene and polyethylene terephthalate, to provide protection from mechanical influences, to guarantee its structural integrity and physical influences such as oxygen and moisture. To some extent, traditional packaging protects the products against UV light. The quality of consumer products may become affected over time as a consequence of the influence of UV light.

Petroleum-sourced materials have the disadvantage that they do not degrade and compost easily in the environment, causing pollution in e.g. oceans. An alternative to petroleum-based plastics are bioplastics, originating from e.g. bacteria. A challenge arose, how to develop a flexible barrier laminate to use in flexible packaging products for consumer products, such as soap bars and other personal care products, laundry detergents, and food products, which is more environmentally friendly, preferably biodegradable, which provides proper UV barrier properties to the packaged consumer product, preferably which does not only protects the structural integrity but also provides proper protection against UV light, and preferably is transparent.

W02023/008901 A1 relates to a biodegradable multilayer film comprising a base layer and a biodegradable resin layer, wherein the biodegradable resin layer includes a polyhydroxyalkanoate (PHA) resin.

EP3907078 A1 relates to a biodegradable container comprising a thermoformable structural layer with tear resistance and low cost, and optionally an adhesive barrier layer, an adhesive active layer and/or a layer in direct contact with the product, all of which are based on biodegradable polymers. EP3778233 A1 relates to a biodegradable laminate including: an aliphatic polyester-based resin layer; a bonding layer; and a polyvinyl alcohol-based resin layer laminated on at least one surface of the aliphatic polyester-based resin layer with the bonding layer therebetween.

Summary of the invention

Surprisingly, this aim was met, at least partly, with the following invention, which relates in a first aspect to a flexible barrier laminate comprising:

• a layer comprising: polyhydroxyalkanoate (PHA), particles, present in the PHA layer, wherein the particles are present in an amount of from 0.1 to 50 wt%, preferably 0.5 to 20 wt%, even more preferably 1 to 10 wt% and even more preferably 3 to 10 wt%, based on the weight of the PHA layer and particles taken together, wherein the particulate material is selected from the group consisting of lignin, talc, olive stone powder, wine plastics filler, vine shoot powder, clay, graphene, graphene oxide and mixtures thereof, preferably lignin, olive stone powder, wine plastics filler, vine shoot powder, clay, graphene, graphene oxide and mixtures thereof, more preferably clay, talc, lignin and mixtures thereof, more preferably clay or lignin or mixtures thereof and most preferably wherein the particulate material are lignin particles,

• A cellulose fiber-based layer, being a paper layer or cardboard layer, and wherein the PHA layer has a thickness of from 1 to 60 micrometer, preferably from 5 to 20 micrometer.

In a second aspect, the invention relates to a packaged consumer product, wherein a consumer product is packaged in a packaging product comprising a barrier laminate according to the invention.

In a third aspect, the invention relates to process to manufacture the barrier laminate of the invention.

In a fourth aspect, the invention relates to the use of particles in a PHA-based barrier layer, in a packaging product comprising a barrier laminate of the invention, to enhance the UV barrier property of the barrier laminate. Detailed description

The invention relates to a flexible paper- or cardboard-based barrier laminate which can be used to prepare a packaging product for packaging consumer products. Consumer products typically are packaged in a packaging product such a sachet or wrapper. Consumer products are protected against influence from UV light by packaging products which are typically prepared from barrier laminates. To reduce or preferably avoid the use of petroleum-derived materials in a barrier laminate to protect the structural integrity of consumer products while reducing UV influence, it was surprisingly found to use a packaging product that is manufactured from a barrier laminate that comprises a polyhydroxy alkanoate (PHA) layer, in combination with a cellulose fiber-based layer. The amount of petroleum derived material in the barrier laminate is preferably below 10 wt%, more preferably below 5 wt%, even more preferably below 1 wt%, based on the weight of the barrier laminate in the packaging product, and preferably is absent from the barrier laminate.

Polyhydroxy alkanoates are a type of bioplastic, known in the art and commercially available in several forms. PHA are a family of polymers which are produced by bacteria through the fermentation of sugar as an energy store to consumer later on. PHAs have similar properties to some of the commonly used polyolefin-based polymers: they are melt processable, tuneable, and have excellent mechanical properties and some barrier properties. The most common form of PHA is polyhydroxy-3-butyrate, which is produced by bacteria. Via genetic modification on the bacteria, to affect the molecule weight of the polymer chains and the composition of the polymer chains, other PHA can be produced.

There are over 150 available monomers to produce PHAs, as known in the art. The PHAs preferred in the present invention are preferably short-chained (C1-C2 side chains), medium chained (C3-C8 side chains) or long chained (C9 and higher side chains) PHAs, defined based on the length of the carbon chain of the side groups. More preferably, the PHAs are short chained PHAs. Within the context of the invention, the PHA is preferably selected from the group consisting of polyhydroxy-3-butyrate (PHB), polyhydroxy-3-butyrate-co-hydroxyvalerate (PHBV), polyhydroxy-3-butyrate-co-hydroxyhexanoate (PHBH) and polyhydroxy-3-butyrate-co- hydroxy-4-buyyrate (P3HB-4HB), and mixtures thereof. Even more preferably, the PHA is selected from the group consisting of PHB, PHBV and PHBH. These preferred PHAs are all short-chained PHAs or medium-chained PHAs and commercially available, as known to the person skilled in the art. Other examples of medium chained PHAs include polyhydroxyheptanoate and polyhydroxyoctanoate. Examples of long chained PHAs include polyhydroxydecanoate, polyhydroxyundecanoate and polyhydroxydodecanoate. It may be preferred that the PHA barrier layer comprises PHBV. It may be preferred that the PHA barrier layer comprises comprises PHBH. Preferably no petroleum-derived or synthetic polymers are present in the PHA layer. PHA is preferably present in the PHA barrier layer in an amount of more than 95 wt%, preferably more than 99 wt%, most preferably 100%, based on the weight of the total polymer in the PHA layer(s) comprising particles. Most preferably PHA is the only biodegradable polymer in the barrier layer or barrier laminate. Preferably no petroleum-derived or synthetic polymers are present in the barrier laminate, excluding in an optional ink layer or ink-protection/OPV layer.

PHAs are present and can be designed and commercially bought with different levels of crystallinity. The level of crystallinity is tunable and dependent on the monomeric composition, the bacterial strain used in production and the substrate and process parameters used during production of the PHA. Typically, there is a tradeoff between mechanical properties vs barrier properties whereby more rigid PHAs have better barrier properties and more flexible PHAs have poor barrier properties. This is mostly due to the degree of crystallinity (overall percentage of polymer chains which are in crystal structure) vs. amorphous polymer content (overall percentage of polymer chains which are not in crystal structure). The longer the side chain, the better the general flexibility of the polymer and worse barrier properties. Accordingly, the PHA used in the material of the invention preferably has a degree of crystallinity of from 5 to 95 %, preferably of from 15 to 70%. The amorphous polymer content present in the PHA is preferably from 95 % to 5% and more preferably from 85% to 30%.

It was surprisingly found, that the UV barrier properties of a barrier laminate comprising a PHA layer could be enhanced, when specific particulates were included in the PHA layer in a specific amount. Accordingly, the PHA layer in the barrier laminate preferably comprises from 0.1 to 50 wt%, more preferably from 0.5 to 20 wt%, and even more preferably from 0.5 to 14 wt%, and even more preferably from 1 to 10 wt%, and most preferably from 3 to 10 wt%, based on the weight of the PHA layer and of the particulates taken together, of particulates. The particulates preferably have a size Dso of between 10 nm and 100 micrometers, preferably of between 500 nm and 20 micrometers, and most preferably of from 700 nm and 10 micrometers. Best results are seen with particles with a platelet shape, i.e. with an aspect ratio of between 1 to 10,000, preferably between 50 and 1100. For example, preferred aspect ratio for bentonite clay 500- 5000, for talc 1-500, for halloysite 1-500, for vermiculite 500-10,000. Typically, the particles are homogenously distributed through the PHA layer. Preferably the particles are only present in the PHA layer. It can be preferred, that in case more than one PHA layer is present, the particles are present in one PHA layer. It is preferred that there is one PHA layer. Preferably, the particles are organic particulates or inorganic particulates. More preferably, the particulates are of materials selected from the group consisting of lignin, talc, olive stone powder, wine plastics filler (e.g. from Agromateriae), vine shoot powder (e.g. Sarmine™ from Vitis Valorem), clay, graphene, graphene oxide and mixtures thereof.

Preferably, the PHA layer in the barrier laminate comprises from 0.1 to 50 wt%, more preferably from 0.5 to 20 wt% and more preferably from 1 to 10 wt%, and most preferably from 3 to 10 wt%, based on the weight of the PHA layer and of the particulates taken together, of particulates selected from the group consisting of lignin, olive stone powder, wine plastics filler (e.g. from Agromateriae), vine shoot powder (e.g. Sarmine™ from Vitis Valorem), clay, graphene, graphene oxide and mixtures thereof.

More preferably, the PHA in the barrier laminate comprises from 0.1 to 50 wt%, more preferably from 0.5 to 20 wt% and more preferably from 1 to 10 wt%, and most preferably from 3 to 10 wt%, based on the weight of the PHA layer and of the particulates taken together, of particulates selected from the group consisting of lignin, clay, talc, graphene, graphene oxide and mixtures thereof.

Even more preferably, the PHA layer in the barrier laminate comprises from 0.1 to 50 wt%, more preferably from 0.5 to 20 wt% and more preferably from 1 to 10 wt%, and most preferably from 3 to 10 wt%, based on the weight of the PHA layer and of the particulates taken together, of particulates selected from the group consisting of lignin, clay, and mixtures thereof.

It may be preferred, that the PHA layer in the barrier laminate comprises from 0.1 to 50 wt%, more preferably from 0.5 to 20 wt% and more preferably from 1 to 10 wt%, and most preferably from 3 to 10 wt%, based on the weight of the PHA layer and of the particulates taken together, of particulates selected from the group consisting of lignin, graphene, graphene oxide and mixtures thereof. Graphene, graphene oxide or mixtures thereof are preferably present in an amount of from 0.25 to 5 wt%, preferably 0.5 to 3 wt%, based on the weight of the PHA layer and of the particles taken together.

It is most preferred, that the PHA in the barrier laminate comprises from 0.1 to 50 wt%, more preferably from 0.5 to 20 wt% and more preferably from 1 to 10 wt%, and most preferably from 3 to 10 wt%, based on the weight of the PHA layer and of the particulates taken together, lignin particulates.

It may be preferred that the particles comprise, more preferably are organic particles (e.g. comprising carbon atoms). It may be preferred, that there are not more than two types of particles, or even more preferably not more than one type of particles selected from the types of the list consisting of lignin, olive stone powder, wine plastics filler, vine shoot powder, talc, clay, graphene, graphene oxide. Preferably the polyhydroxy alkanoate layer comprises lignin, talc or clay particles, more preferably lignin or clay particles, most preferably lignin particles. Clay particles can for example be bentonite, kaolin, cloisite, laponite, vermiculite, halloysite, sepiolite, attapulgite and mixtures thereof, preferably cloisite. Preferably, the particles are hydrophobic particles. It may be preferred that the particulate material does not comprise talc. The particles preferably are free of cellulose nanocrystals.

The PHA layer comprising particulates in a barrier laminate comprising a cellulose fiber-based (such as preferably a paper-based) layer and a PHA barrier layer, preferably has a thickness from 1 micrometer to 60 micrometers, preferably from 5 micrometers to 20 micrometers. The gsm of this PHA layer preferably is from 1.25 gsm to 75 gsm, more preferably from 6.25 gsm to 25 gsm.

It is preferred, that further layers are present in the barrier laminate, apart from the PHA layer and the cellulose-fiber based layer. The total thickness of the barrier laminate comprising a cellulose fiber-based layer preferably is from 30 to 225 micron, and more preferably from 60 to 100 micron. It is preferably from 35 to 250 gsm and more preferably from 60 to 120 gsm. A relatively thin barrier laminate may be preferred in view of the flexibility.

The barrier laminate is a flexible barrier laminate and preferably a sheet or a film, e.g. a two- dimensional barrier laminate. It is shaped to form a packaging product, preferably a sachet or a wrapper.

Further layers

Cellulose fiber based layer

According to the invention, the barrier laminate comprises a cellulose fiber-based layer. This is preferably a paper layer or cardboard layer, preferably a paper layer. The laminate preferably comprises a total of one paper layer. A cellulose fiber-based barrier layer as such is vulnerable for external influences, and therefore is preferably not in contact with the outside world, i.e. is preferably not located at the periphery of the barrier laminate. A cellulose fiber-based layer, e.g. a paper layer, is preferably covered at both sides with another layer.

The cellulose fiber-based layer preferably comprises paper, or more preferably is paper, with a grammage of between 40 and 100 gsm, preferably of 50 to 90 gsm, even more preferably from 50 to 80 gsm and most preferably of 50 to 70 gsm. This provides suitable rigidity to the final packaging product to contain a consumer product, such as for example a wrapper or sachet, whereas it can be suitably transported in a packaging line, e.g. over rollers. In view of the aim of providing a barrier laminate with less impact on the environment, it may be preferred, that paper is present in an amount of more than 80 wt%, more preferably more than 85 wt%, based on the total weight of the barrier laminate. Preferably paper fibers constitute more than 80 wt%, more preferably more than 85 wt%, based on the total weight of the barrier laminate. It may be preferred, that the amount of total amount of polymer, for example the amount of plastic, is below 20 wt%, preferably below 15 wt%, based on the weight of the barrier laminate. It can be for example from 9 to 20 wt%, more preferred from 11 to 15 wt%. It may be preferred, that the total amount of petroleum-based polymer, for example the amount of petroleum-based plastic, is below 20 wt%, preferably below 15 wt%, based on the weight of the barrier laminate. It can be for example from 9 to 20 wt%, more preferred from 11 to 15 wt%. A paper content of more than 80 wt% is typically considered to meet the criteria for recyclability in many countries.

Ink layer

Apart from the PHA layer and the cellulose fiber-based layer, the barrier laminate may further comprise an ink layer. The barrier laminate is used in a packaging product to protect a consumer product. In this respect, it also provides a communication function to the consumers who will buy the consumer products, typically via information printed on one of PHA, cellulose-fiber layer or other barrier layer, such as a metal oxide layer, including information regarding ingredients, appealing artwork and advertisement etc. The barrier laminate therefore preferably comprises a layer of ink. The layer of ink is preferably in direct connection with the PHA or cellulose fibre layer and typically faces the outside of the barrier laminate (e.g. when applied in a consumer packaging), i.e. the site opposite to the site of the barrier laminate that will be in contact with the consumer product to be packaged.

Protection layer

For example, to protect the ink layer, the barrier laminate preferably comprises a protection layer, typically on top of the ink layer, e.g. to protect the ink and/or other layers from external influences like moisture. The protection layer is typically facing the outside world. It is typically located opposite to the product-facing site of the laminate (e.g. when applied in a consumer packaging). The protection layer may be an over-print varnish (OPV), OPVs are well-known to the person skilled in the art and the chosen varnish depends on the intended use of the barrier laminate of the present invention. For example, the OPV may be selected from the group consisting of conventional offset letterpress varnishes, acrylic varnishes, UV varnishes, and gravure varnishes. The protection layer may be a PHA layer. In the case that the protection layer is a PHA layer, it is typically a second PHA layer in addition to the PHA layer comprising particulates. The second PHA layer (protection layer) may comprise particulates, in the same manner as the first PHA layer. Alternatively, it may be preferred that the second PHA layer (protection layer) is free from particulates, in particularly is free from the particulate as indicated above as preferred for the first PHA layer. It may however be preferred, that the PHA protection layer is the only PHA layer and is a first PHA layer, and accordingly comprises the particulates and has a thickness of less than 20 micrometers, preferably less than 10 micrometers, and in this situation preferably a cellulose fiber-based layer is present as well. It may be preferred, that the barrier laminate has not more than three or even more preferably not more than two PHA layers. It may be preferred, that in case more than one PHA-based layer is present in the barrier laminate, one PHA-based layer is protecting an ink layer or is covering a metal or metal oxide layer. It may be preferred, that more than one PHA-based layer is present in the barrier laminate, one PHA-based layer is protecting an ink layer or is covering a metal or metal oxide layer. It may be preferred, that if a cellulose fiber-based layer is present, and if more than one PHA- based layer is present in the barrier laminate, one PHA-based layer is protecting an ink layer or is covering a metal or metal oxide layer. It may be preferred, that a cellulose fiber-based layer is present in the barrier laminate, and more than one PHA-based layer is present in the barrier laminate, and one PHA-based layer is protecting an ink layer or is covering a metal or metal oxide layer. It is preferred, that if more than one PHA layer is present in a barrier laminate comprising a cellulose fiber-based substrate layer, a PHA layer is present on each side of the cellulose fiber based substate layer.

OPVs can be water-based polymer formulations or solvent-based polymer formulations. An OPV that is not petroleum derived is preferred. The protection layer typically is deposited directly on the ink layer, it is preferably in direct contact with the ink layer. The protection layer faces an outside of the barrier laminate, typically the site opposite to the site that is intended to face or faces the consumer product to be packaged.

The thickness of the protection layer is preferably between 0.5 and 15 microns, preferably of between 1 and 8 microns, even more preferably of between 1 and 2 microns.

Further barrier layer

It may be preferred, that a further barrier layer is present. The further barrier layer preferably is not petroleum based. It may be preferred, that the barrier laminate comprises a layer of metal or metal oxide. Preferably a total of one layer of metal oxide is present in the laminate. The layer of metal oxide may be positioned at the product facing side of the laminate or at the external environment facing side of the laminate. It might be preferred however, that no metal layer or metal oxide is present in the barrier laminate.

The metal oxide layer can be positioned, if present on either side of the PHA layer comprising particulates. The metal oxide layer can be in direct contact with the PHA layer.

It is preferred that the metal oxide layer, if present, is present at the product-facing side of the cellulose fiber-based layer, (i.e. paper or cardboard layer, preferably paper layer). It can be preferred in this situation that the metal oxide layer is positioned between the cellulose-fiber- based layer (e.g. paper layer) and the PHA layer.

The additional barrier layer preferably comprises one or more selected from the group consisting of aluminum metal, aluminum oxide, zinc oxide, titanium oxide, silicon oxide and combined layers of these. More preferably, the additional barrier layer comprises aluminum metal or aluminum oxide, and most preferably is an aluminum oxide layer. It may be preferred that the additional barrier layer is aluminum metal or aluminum oxide, preferably in combination with zinc oxide or titanium oxide. The additional barrier layer, such as preferably the metal or metal oxide layer, may be deposited on a precoat layer that precoats the paper. The additional barrier layer may be deposited using techniques used in the art, such as physical or chemical vapor deposition. In case the additional barrier layer comprises multiple materials, such as for example a combination of a metal and a metal oxide or two metal oxides, the layers are deposited on top of each other in layers. The additional barrier layer, such as preferably the metal or metal oxide layer, is preferably treated with plasma. If a metal layer or metal oxide layer is present, it is preferred, that a pre-coat is present on which the metal is deposited. It is preferred that a total of one additional barrier layer is present. In such a case, a single additional barrier layer may consist of layers of metal, metal oxide or both. Alternatively, it can be preferred that the single barrier layer consists of only of a single type of metal or a single type of metal oxide.

The additional barrier layer, preferably comprising a metal layer or metal oxide layer, and more preferably being an aluminum layer or an aluminum oxide layer, preferably has a thickness of between 0.01 and 1 micron.

Precoat layer

It may be preferred, that the barrier laminate comprises one or more, preferably a total of one precoat layer. A precoat layer enhances the adhesion between layers. For example, it may be preferred that a precoat layer is positioned between the PHA layer and a metal or metal oxide layer, if present. Alternatively, it may be preferred, that no precoat is present between the PH A layer and the metal oxide layer. In the case a paper layer is present, it may be preferred that a precoat layer is present between the PHA layer and the cellulose-fiber based layer or between the cellulose fiber-based layer and the metal or metal oxide layer.

A precoat may be present between the PHA layer and the optional metal oxide layer. But, as said, the metal oxide layer may be in direct contact alternatively with the PHA layer, and in this case preferably no pre coat layer is present. A precoat is highly preferably present between the cellulose fiber-based layer and the optional metal oxide layer. In such a situation it may be for example that the cellulose fiber-based layer, such as a paper layer, and PHA are separated by both a pre-coat layer and a metal oxide layer.

A pre-coat proved beneficial to further block the open paper fiber surface and enhance adhesion of the PHA or metal or metal oxide to the paper or of the metal or metal oxide layer to the PHA layer. Adhesive is less suitable for this purpose in the present context and preferably is absent from the barrier laminate. The precoat may be, for example, one or more layers, either with or without a mineral filler, selected from the group consisting of acrylic acid, ethylene-acrylic or methacrylic acid copolymers, butenediol vinyl alcohol copolymers (BVOH), cellulose nitrate, ethyl-vinyl acetates, ethylene vinyl alcohol (EVOH), microfibrillated cellulose (MFC), nanocrystalline cellulose (NCC), native and chemically modified starches, polybutylene adipate terephthalate (PBAT), polybutylene succinate (PBS), poly(butylene succinate-co-adipate) (PBSA), polyesters, polyhydroxyalkanoates (PHA) and their copolymers, polylactic acid (PLA), polyolefins, polyurethanes (Pll), polyvinyl acetate (PVAc), polyvinyl alcohol (PVOH), polyvinyl dichloride, silanes, styrene acrylate, styrene-butadiene, waxes, or xylan and chemically modified xylan, preferably acrylic acid, ethylene-acrylic or methacrylic acid copolymers, butenediol vinyl alcohol copolymers (BVOH), ethyl-vinyl acetates, ethylene vinyl alcohol (EVOH), polyesters, styrene acrylate, styrene-butadiene, PVOH, PBAT, PBS, PBSA, PHA, cellulose based materials and combinations thereof. It is preferable, that the precoat is not a petroleum-based material. It may be preferred that the precoat comprises, or consists of one or more materials selected from the group consisting of EVOH, PVOH, PBAT, PBS, PBSA, PHA, and cellulose based materials. It could be preferred that the barrier layer or laminate does not contain PVOH or EVOH, preferably does not contain PVOH. The precoat layer has preferably a thickness of between 1 and 10 gsm, preferable 1.5 to 6 gsm. The pre-coat can suitably be applied using dispersion or extrusion coating, as known to the skilled person.

Heat seal layer

The barrier laminate typically comprises a sealing layer. A heat sealing layer facilitates the preparation of a packaging product comprising the barrier laminate. A sealing layer allows the barrier laminate to be heat sealed. In this manner, parts of the barrier laminate can be sealed together, for example after folding, to form a typically three-dimensional packaging product, such as a wrapper or sachet.

Accordingly, the sealing layer is typically a peripheral layer of the barrier laminate, which typically represents the product-facing side in a packaging (like a sachet) made from the laminate. Accordingly, the sealing layer is positioned at the product-facing site of the barrier laminate. Within the barrier laminate, the sealing layer is preferably only on one side in contact with another layer of the laminate, and the sealing layer is preferably facing the outside world (i.e. not covered with a further layer). The sealing layer may be selected from the group of heat seal layer, cold seal layer and pressure seal layer.

The sealing layer, preferably the heat-sealing layer, can be in the form of an additional coating layer or be in the form of the particulate-comprising PHA layer.

The sealing layer, in the case an additional coating layer is applied, may range between 1 and 10 gsm, preferably between 2 and 5 gsm.

Preferably, the sealing layer is a heat seal layer. Typical heat seal layers comprise one or more thermoformable polymers such as poly(ethylene) homo- and co-polymers, poly(propylene) homo- and co-polymers, poly(1 -butene) (PB), ethylene vinyl acetate) (EVA) copolymers and terpolymers, poly(ethylene-co-acrylic acid) (EAA), poly(ethylene-co-methacrylic acid) (EMA), ionomer, polyvinyl alcohol (PVOH) semicrystalline poly(ethylene terephthalate) (CPET), amorphous PET (APET), poly(ethylene glycol-co-1 ,4-cyclohexanedimethanol terephthalate) (PETG), poly(lactic acid) (PLA), poly(butylene succinate) (PBS), poly(3-hydroxybutyrate-co-3- hydroxyvalerate) (PHBV), poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx), styrene/butadiene (SBS) copolymers, thermoplastic starch, poly(hexano-6-lactam) (Nylon 6), preferably ethylene-vinyl acetate (EVA) copolymers, poly(ethylene-co-methacrylic acid) (EMA), or styrene/butadiene (SBS) copolymers. More preferably, the heat seal layer is selected from the group consisting of PHAs, PBS, PVOH, EVA, EMA or SBS copolymers. It may be preferred that the heat seal layer is prepared from a material that is not petroleum based. In the case that the PHA layer comprising particles is a sealing layer, it is preferred that it is free from other polymers, to optimize biodegradability. Preferably PHA is the only biodegradable polymer in the sealing layer, more preferably in the barrier laminate. The sealing layer, preferably the barrier laminate, is preferably free from PP, PE, nylon, PET. The sealing layer, preferably the barrier laminate, is preferably free from PLA, or PVOH.

The heat seal layer may be applied by dispersion coating or extrusion coating. The heat seal layer may be with or without a mineral filler. Apart from possibly in the sealing layer, it can be preferred that the barrier laminate of the present invention does not comprise polypropylene, polyethylene, polyethylene terephthalate.

As known in the art, the sealing polymer can be deposited on the underlying layer by providing a dispersion of polymer particles in a solvent that is provided on the base layer, such as the on the PHA layer (dispersion coating). The solvent is consequently removed, for example by heating, and the polymer particles are deposited on the base layer, e.g. the PHA layer. Alternatively, as known in the art, the sealing polymer can be extruded (extrusion coating), typically via extruding molten resin through a slot die directed onto the base laminate and then passed through a nip that may comprise a covered pressure roller, typically rubber-covered, and cooling roller that typically may be chrome plated. This base-laminate surface is typically moving at a speed which is faster compared to the extruded film and draws the film onto the desired thickness. The sealing layer is typically located on the side of the barrier laminate that will face the product to be packaged. It can be preferred that no other layer is present between the PHA layer and the sealing layer, typically when the sealing layer is applied at the same site of the paper layer as the first PHA layer (3). It can be preferred, e.g. typically when the sealing layer is applied at the opposite side of the paper layer, e.g. when one PHA layer is present, that the paper is between the sealing layer and the PHA layer. This is exemplified in examples 1A, 1 D, 1 F, 1 H, 11, 1 J, 1 K, H and 1 M.

The sealing layer is preferably of between 1 and 10 gsm, preferably between 1.5 and 6 gsm, more preferred between 2 and 5 gsm.

It may be preferred that the barrier layer or barrier laminate is transparent or translucent, preferably transparent.

Packaging product The barrier laminate as described above can be formed into a packaging product comprising the barrier laminate, to allow packaging of a consumer product. Typically, this is a flexible packaging product. The packaging product may be in the form of a flow-wrap, pillow bag, gusseted bag, stand-up pouch, diaper bag, tetrahedral bag, quattro seal bag or sachet. The packaging product preferably contains a consumer product. The consumer product may for example be in solid form at room temperature (RT), in powder form at RT, in liquid form at RT, or in semi-solid form at RT.

Accordingly, the invention further relates to a packaged consumer product, wherein a consumer product is packaged in a packaging product comprising barrier laminate according to the invention.

Typical consumer products that can be packaged using packaging products with flexible barrier laminate of the invention are preferably selected from the group consisting of frozen confectionary, bouillon, soup, sauces, coffee, tea, supplements, vitamins, electrolyte powders, laundry detergents, skin cleansing products, skin care products and haircare products.

In particular, it is preferred that the packaging product is a sachet, a pouch or a wrapper. A wrapper can be used for example to wrap a soap bar, a frozen confectionary productor a condiment like a bouillon or seasoning concentrate.

The packaging product typically comprises seal areas where parts of the barrier laminate are sealed to each other. This may be for example heat seal areas, cold seal areas or sound seal areas, but preferably heat seal areas. The seal areas are located typically at the periphery of the packaging product.

Process of manufacturing

In a further aspect, the present invention relates to a process to manufacture a barrier laminate comprising polyhydroxy alkanoate of the invention. The process comprises the steps of: a) Providing polyhydroxy alkanoate, b) Mixing particulates into the PHA of step a) in an amount of from 0.1 to 50 wt%, preferably 0.5 to 20 wt%, even more preferably 1 - 10 wt%, and most preferably from 3 to 10 wt%, based on the weight of the resulting PHA-particulates mixture, c) Forming a layer from the mixture resulting from step b), wherein the layer has a thickness of between 1 and 60 micrometer, preferably 5 to 20 micrometer, and combining it with a cellulose fiber-based layer, to result in a barrier laminate. A barrier laminate may comprise apart from the PHA layer, one or more of a paper layer, a precoat layer, a metal layer or a metal oxide layer, such as for example aluminum or aluminum oxide and a sealing layer.

In step a) a batch of PHA is provided. PHA can be commercially sourced e.g. from Kaneka Corporation. The degree of crystallinity of the PHA preferably is between 5 and 95%, but preferably between 15 and 70%. The degree of crystallinity is a product feature which can be adjusted based on the genetic modification of the microorganism species which produces the PHA, the substrate on which it is fed, the growing conditions, etc. Commercially available PHAs can be ordered with a specific degree of crystallinity and a specific degree of amorphous PHA polymer content.

The PHA preferably is selected from short chain (C1-C2 side chains), medium chain (C3-C8 side chains) or long chain (C9 and higher side chains) PHAs. It is preferred, that the PHA is selected from the group consisting of, polyhydroxy-3-butyrate, polyhydroxy-3-butyrate-co- hydroxyvalerate, polyhydroxy-3-butyrate-co-hydroxyhexanoate, polyhydroxy-3-butyrate-co- hydroxy-4-butyrate, amorphous polyhydroxyalkanoate and mixtures thereof. More preferably, the polyhydroxyalkanate is selected from the group consisting of, polyhydroxy-3-butyrate, polyhydroxy-3-butyrate-co-hydroxyvalerate and polyhydroxy-3-butyrate-co-hydroxyhexanoate and mixtures thereof.

The PHA is for example positioned into a hopper for controlled feeding into an extruder barrel to be compounded. The PHA typically is melted in the barrel.

Once the PHA is melted in the extruder barrel, in step b) particulates are mixed into the PHA. This is suitably done via a secondary feeder apparatus further along the extruder barrel, as known in the art. Mixing is typically done under application of shear. The shear from the extruder screws results in a homogeneous distribution of particles. In this manner it is achieved that there are no particle agglomerations. This results in a D50 and particulate distribution in the PHA- particulate mixture which is optimal in the context of the present invention. The particulates preferably have a D50 of from 10 nm to 100 micrometers, preferably from 500 nm to 20 micrometers, more preferably from 700 nm to 10 micrometers. The particulate matter is platelet shaped, with an aspect ratio of from 1 to 10,000, preferably of from 50 to 1000. Preferably the particulate material is selected from the group consisting of lignin, olive stone powder, wine plastics filler, vine shoot powder, talc, clay, graphene, graphene oxide and mixtures thereof. More preferably selected from the group consisting of lignin, olive stone powder, wine plastics filler, vine shoot powder, clay, graphene, graphene oxide and mixtures thereof. Even more preferably, polyhydroxyalkanoate layer comprises clay or lignin and even more preferably comprises lignin particles, for optimal UV barrier properties.

In step c), a layer is formed from the PHA comprising particulates. This is typically achieved by extruding the mixture for example using a cast film extruder, blown film extruder or extrusion coating. This is preferably via a die on either a cast film extruder, blown film extruder or via extrusion coating. Typically, by decreasing the temperature below the solidification temperature of the PHA a solid layer is formed.

The thickness of the PHA layer comprising particulates can be controlled by the rate of extrusion as well as in blown film extrusion the size of the bubble and the pull rate of the film; in cast film extrusion the tension of the rollers; in extrusion coating the pressure applied to the molten PHA on the construct. The gsm of the PHA layer comprising particles is preferably from 1 .25 gsm to 75 gsm, more preferably from 6.25 gsm to 25 gsm if the barrier layer is part of a barrier laminate, preferably a barrier laminate comprising a cellulose fiber-based layer such as preferably a paper layer.

In step c), the PHA layer can be combined with one or more other layers, as described in the context of the first aspect.

Cellulose fiber-based layer

The process preferably comprises the steps of providing a cellulose-fiber based layer and combining it with the PHA layer. Combining includes directly combining and indirectly combining the cellulose fiber-based layer with the PHA layer, to result in a direct contact between the cellulose fiber-based layer and the PHA layer, or the situation that one or more layers are present between the cellulose fiber based layer and the PHA layer, such as a pre coat layer, a further barrier layer such as a metal oxide or metal layer or both. It may be preferred that the combination involves adhesion of the PHA on an underlying layer, wherein the underlying layer may be the cellulose fiber based layer, a pre-coat layer, e.g. deposited on a cellulose fiber based layer, or a metal or metal oxide layer, e.g. deposited on a cellulose fiber based layer that is preferably coated with pre-coating. This provides a direct contact between the layers.

Deposition of pre-coating

A pre-coat may be applied e.g. using dispersion coating, using different processes and coaters as known in the art. Various coating methods can be used, such as blade, rod, air knife, gravure and curtain coaters, which are commonly used to apply a thin layer of material to which the solvent is evaporated. Evaporation of solvent can be effectuated by several methods, such as infra-red dryers, air float dryers and impingement dryers. Examples of the dispersion coating process are described by Kimpimaki, T., Savolainen, A.V. (1997), Barrier dispersion coating of paper and board. In: Brander, J., Thorn, I. (eds) Surface Application of Paper Chemicals. Springer, Dordrecht. Regardless of the processing method, the outcome typically is a uniform and continuous polymer film onto the substrate.

Deposition of an additional barrier layer

The barrier laminate may comprise a further barrier layer, such as preferably a metal layer or metal oxide layer, as described above.

An additional barrier layer may be applied by deposition techniques as known in the art, such as for example physical vapour deposition (PVD), chemical vapor deposition (CVD), plasma- enhanced chemical vapor deposition (PECVD), atomic layer deposition (ALD), sputtering and sol-gel coating.

An additional barrier layer may be deposited by PVD as described in Thin Solid Films, Volume 666, 2018, pp 6-14 and Mattox, D.M. (2010), Handbook of Physical Vapor Deposition (PVD) Processing, Elsevier Science, pp. 195-237. During vacuum deposition onto a flexible film, a solid is heated and vaporized in a vacuum before being deposited under vacuum over a web of film that is spooled in the vacuum chamber between a feed roller and a take-up roller.

An additional barrier layer may be deposited by CVD as described in R. F. Bunshah, Vapor deposition technologies, in Handbook of hard coatings: Deposition technologies, properties and applications, G. E. McGuire, S. M. Rossnagel and R. F. Bunshah, eds., 2001 , Noyes Publications, William Andrew Publishing, LLC, Norwich, NY, p. 4-76. The process is similar to PVD but introduces addition a precursor gas which reacts with the vaporized metal for form compounds such as oxides in the vapour phase before being deposited onto a web of film. If a plasma is applied to induce the decomposition of the precursor, the process is called plasma enhanced CVD (PECVD) or plasma assisted CVD (PACVD).

An additional barrier layer may be deposited by ALD as described by Hong Chen Guo, Enyi Ye, Zibiao Li, Ming-Yong Han, Xian Jun Loh, Recent progress of atomic layer deposition on polymeric materials, Materials Science and Engineering: C, Volume 70, Part 2, 2017, Pages 1182-1191. ALD is a special variant of the CVD technique where gaseous reactants known as precursors are introduced into the reaction chamber. These precursors react with the surface of a material one at a time in a sequential, self-limiting, manner. A thin film is slowly deposited through repeated exposure to separate precursors. An additional barrier layer may be deposited by sputtering as described by R Lewin, RP Howson, CA Bishop, Ml Ridge, Transparent conducting oxides of metals and alloys made by reactive magnetron sputtering from elemental targets, Vacuum, Volume 36, Issues 1-3, 1986, Pages 95-98 and by R. C. Merrill; G. J. Egan; B. W. Paszek; A. J. Aronson, Continuous Sputtering of Metals on Plastic Film Substrates, Journal of Vacuum Science & Technology, Volume 9, Issue 1 , 1972, Pages 350-353. Sputtering is a technique in which metal atoms are removed from a solid target by means of ion bombardment and are then absorbed on the substrate surface facing the target.

An additional barrier layer may be deposited by sol-gel coating as described by Wang, S., Mahlberg, R., Nikkola, J., Mannila, J., Jamsa, S., Ritschkoff, A.-C. and Peltonen, J. (2012), Surface characteristics and wetting properties of sol-gel coated base paper. Surf. Interface Anal., 44: 539-547. Sol-gel coatings are inorganic ceramic materials or inorganic-organic hybrid materials. Small molecules are dispersed in a solvent as a colloidal dispersion (sol) that react together via hydrolysis then polycondensation to form a solid three-dimensional polymeric network (or gel).

When a further barrier layer is deposited, e.g. on a cellulose fiber-based layer, such as a paper or cardboard layer, or on the PHA barrier layer, preferably a pre coat layer is deposited between them and in direct contact with the cellulose fiber-based layer or PHA barrier layer, and the resulting further barrier layer. This is especially the case when the further barrier layer is a metal layer or metal oxide layer. A metal layer or metal oxide layer can be deposited on the PHA layer, with or without the need for deposition of a pre coat layer. It is preferred, that no adhesive layer is present in the barrier laminate, preferably no petroleum sourced adhesive layer.

Deposition of a sealing layer

According to step d) of the process, a sealing layer is applied. This is preferably done with the processes and coaters as used for the application of a pre-coat layer, as described above. The coating methods such as blade, rod, air knife, gravure and curtain coaters are commonly used to apply a thin layer of material to which the solvent is evaporated. Evaporation of solvent can be by several methods, such as infra-red dryers, air float dryers and impingement dryers. Examples of the dispersion coating process are described by Kimpimaki, T., Savolainen, A.V. (1997). Barrier dispersion coating of paper and board. In: Brander, J., Thorn, I. (eds) Surface Application of Paper Chemicals. Springer, Dordrecht. Regardless of the processing method, the outcome should be uniform and continuous polymer film onto the substrate.

Packaging product It may be preferred, that the process in the invention further comprises a step d), wherein the barrier laminate resulting from step d), is shaped into a packaging product. Shaping preferably involves a sealing step. Sealing may be heat-sealing, cold sealing, pressure sealing, but preferably involves heat sealing. Sealing is carried out as known to the skilled person.

It may be preferred, that in a step e) of the process, the packaging product resulting from step d) is filled with a consumer product. Filling may be followed by an additional step of closing the packaging product. Closing may involve sealing step, preferably a heat-sealing step.

Use

The present invention in a further aspect relates to the use of particulates in a PHA layer in a barrier laminate in a packaging product, wherein the packaging product comprises a barrier laminate, and the barrier laminate comprises a layer of PHA, and a cellulose fiber-based layer being paper or cardboard, and wherein the PHA layer comprises particulates in an amount of from 0.1 to 50 wt%, preferably 0.5 to 20 wt%, more preferably 1 to 10 wt% and most preferably from 3 to 10 wt%, based on the weight of the PHA-particulates layer, wherein the particulates preferably have a Dso of from 10 nm to 100 micrometers, preferably from 500 nm to 20 micrometers, more preferably from 700 nm to 10 micrometers, and wherein the particulate material is selected from the group consisting of lignin, talc, olive stone powder, wine plastics filler, vine shoot powder, clay, graphene, graphene oxide and mixtures thereof, preferably selected from lignin, olive stone powder, wine plastics filler, vine shoot powder, clay, graphene, graphene oxide and mixtures thereof, more preferably selected from clay, lignin and mixtures thereof, most preferably wherein the particulate material are lignin particles, wherein the packaging product contains a consumer product, to enhance barrier properties of the barrier laminate against UV light.

The invention will now be exemplified by the following, non-limiting examples. Example

UV barrier property was assessed for a barrier laminate comprising PHA.

Example 1

Materials

Packaging: 6 PHA-based barrier laminates were used (samples A-F), wherein the PHA was PHBH, and the level of crystallinity was 18.4% and amorphous polymer was 81.6%. Five of the PHA layers (sample B-F) comprised 5 wt% of particulates based on the weight of the PHA and particulates together. Sample A is a control without particulates.

The neat polymer or the neat polymer PHBH + 5wt% of the filler were melt compounded and extruded before films were compression molded at a set thickness of 125 micrometers.

Test

UV light barrier functionality was measured using UV-Vis spectroscopy. The following settings were used:

UV-vis spectrophotometer (Lambda 356, PerkinElmer LAS Ltd., Beaconsfield, UK) equipped with a 50 mm diameter integrating sphere.

Wavelength range of 200-700 nm

Scan speed of 240 nm/min

Slit width of UV-vis spectrophotometer: 1 nm

- Acquisition mode: Absorbance The total light transmittance (%) was assessed for wave lengths ranging from 200-700 nm. As a control, a barrier laminate was used wherein no particulates were present.

Results

Results have been depicted in Figure 1 , showing UV-Vis Transmittance spectra for PHBH and PHBH containing particles, and in Figure 1 , showing UV-Vis Absorbance spectra for PHBH and PHBH containing particles.

Conclusion

As becomes clear from the example, using PHA based barrier laminate comprising particulates from the group of clay (cloisite), talc, and especially lignin, showed UV effects on the behaviour of the polymer, as seen in Figure 1. Clay and talc particles showed a lower transmittance in the UV active 250-400 nm area than laminates comprising Cellulose nanocrystals or not comprising particulates. Surprisingly, clay provided a better protection compared to talc particles, as seen by the stronger Absorbance 250 nm - 300 nm region from Figure 2. Lignin-comprising laminates surprisingly showed a significant absence of transmittance in the 200-400 nm area (Figure 1). This indicates that PHA based laminates comprising lignin provide even further enhanced protection against influence of UV light in packaging products e.g. containing consumer products. PHA based laminates comprising of cellulose nanocrystals showed no difference in the absorbance with respect to PHA.

Example 2

Several barrier laminates that can be used to form the packaging product as described in the present invention are indicated below.

Paper laminate structures

Claims

1. A flexible barrier laminate comprising:

• a layer comprising: polyhydroxyalkanoate (PHA), particles, present in the PHA layer, wherein the particles are present in an amount of from 0.1 to 50 wt%, preferably 0.5 to 20 wt% and more preferably 1 - 10 wt% and most preferably from 3 to 10 wt%, based on the weight of the PHA layer and particles taken together, wherein the particulate material is selected from the group consisting of lignin, talc, olive stone powder, wine plastics filler, vine shoot powder, clay, graphene, graphene oxide and mixtures thereof, preferably of clay, lignin and mixtures thereof, preferably lignin, olive stone powder, wine plastics filler, vine shoot powder, clay, graphene, graphene oxide and mixtures thereof, more preferably of clay, lignin and mixtures thereof, more preferably wherein the particulate material are lignin particles,

2. The barrier laminate according to claim 1, wherein the particulate material is selected from the group consisting of lignin, clay and mixtures thereof.

3. The barrier laminate according to claim 1 or 2, wherein the particles have a Dso of from 10 nm to 100 micrometers, preferably from 500 nm to 20 micrometers, more preferably from 700 nm to 10 micrometers.

4. The barrier laminate according to any one of the preceding claims, wherein the PHA has a degree of crystallinity of from 5 to 95 %, preferably of from 15 to 70%.

5. The barrier laminate according to any one of the preceding claims, wherein the amorphous polymer content in the PHA layer of the barrier laminate is from 95 to 5%, preferably from 85 to 30%.

6. The barrier laminate according to any one of the preceding claims, wherein the polyhydroxyalkanoate comprises short-chained polyhydroxyalkanoates, having carbon chain side groups with a maximum of 1 or 2 carbon atoms, preferably comprises polyhydroxyalkanoates selected from the group consisting of, polyhydroxy-3-butyrate, polyhydroxy-3-butyrate-co-hydroxyvalerate, polyhydroxy-3-butyrate-co-hydroxyhexanoate, polyhydroxy-3-butyrate-co-hydroxy-4-butyrate, and mixtures thereof, even more preferably, wherein the polyhydroxyalkanate is selected from the group consisting of PHBH, PHBV, and mixtures thereof.

7. The barrier laminate according to any one of the preceding claims, wherein the polyhydroxyalkanoate layer has a thickness of from 1 .25 to 75 gsm, preferably from 6.25 to 25 gsm.

8. The barrier laminate according to any one of the preceding claims, wherein the amount of PHA in the PHA barrier layer is more than 95 wt%, preferably more than 99 wt%, most preferably 100%, based on the weight of the total polymer in the PHA layer.

9. The barrier laminate according to any one of the preceding claims, wherein the total amount of plastic in the barrier laminate is less than 20 wt%, preferably less than 15%, even more preferably less than 10 wt%, based on the weight of the barrier laminate.

10. The barrier laminate according to any one of the preceding claims, wherein the barrier laminate further comprises a metal layer, a metal oxide layer or both.

11. The barrier laminate according to any one of the preceding claims, wherein the barrier laminate further comprises a sealing coating, preferably a heat-sealing coating.

12. The barrier laminate according to any one of the preceding claims, wherein the barrier laminate further comprises an ink layer and an overprint protection layer comprising overprint varnish or polyhydroxy alkanoate.

13. A packaged consumer product, wherein a consumer product is packaged in a packaging product comprising barrier laminate according to any one of claims 1 to 12.

14. Process to manufacture a barrier laminate according to any one of claims 1 to 12, the process comprises the steps of: a) Providing polyhydroxy alkanoate, b) Mixing particulates into the PHA of step a) in an amount of from 0.1 to 50 wt%, preferably 0.5 to 20 wt%, more preferably 1 to 10 wt%, and even more preferably from 3 to 10 wt%, based on the weight of the resulting PHA-particulates mixture, c) Forming a layer from the mixture resulting from step b), wherein the layer has a thickness of between 1 and 60 micrometer, preferably 5 to 20 micrometer, and combining it with a cellulose fiber-based layer being a paper or cardboard layer, to result in a barrier laminate.

15. Use of particulates in a PHA layer in a barrier laminate and further comprising a cellulose fiber-based layer, wherein the particulates are present in an amount of from 0.1 to 50 wt%, preferably 0.5 to 20 wt%, more preferably 1 to 10 wt% and even more preferably from 3 to 10 wt%, based on the weight of the PHA-particulates layer, wherein the particulates preferably have a D50 of from 10 nm to 100 micrometers, preferably from 500 nm to 20 micrometers, more preferably from 700 nm to 10 micrometers, and wherein the particulate material is selected from the group consisting of lignin, talc, olive stone powder, wine plastics filler, vine shoot powder, clay, graphene, graphene oxide and mixtures thereof, preferably of lignin, olive stone powder, wine plastics filler, vine shoot powder, clay, graphene, graphene oxide and mixtures thereof, more preferably of clay, lignin and mixtures thereof, even more preferably wherein the particulate material are lignin particles, to enhance barrier properties of the barrier laminate against UV light.