WO2016151490A1

WO2016151490A1 - Liquid formulation comprising a hindered amine light stabiliser for polyolefins in film production

Info

Publication number: WO2016151490A1
Application number: PCT/IB2016/051617
Authority: WO
Inventors: Andrew Overend; Ricardo Knudsen
Original assignee: Colormatrix Holdings, Inc.
Priority date: 2015-03-25
Filing date: 2016-03-22
Publication date: 2016-09-29
Also published as: GB201505051D0

Abstract

A liquid formulation for dosing into a polymeric material, for example a polyolefin, in film or sheet production, comprises a solvent and a hindered amine light stabiliser dissolved in the solvent, wherein the sum of the wt% of all hindered amine light stabilisers in the formulation is at least 30 wt%.

Description

LIQUID FORMULATION COMPRISING A HINDERED AMINE LIGHT STABILISER FOR POLYOLEFINS IN FILM PRODUCTION

The invention relates to a liquid formulation and particularly, although not exclusively, relates to a liquid formulation comprising a hindered amine light stabiliser (HALS) for dosing into a polymeric material, for example a polyolefin, in film or sheet production.

It is known to use HALS in resins, for example, for agricultural films to stabilise the resin against light degradation. Incorporation of the HALS into the resin may comprise use of a solid masterbatch comprising a resin and up to about 20 wt% of the HALS. Obtaining solid masterbatches with higher HALS concentrations is difficult due to processing issues, such as screw slippage, during extrusion of the masterbatch. Because of this limitation, in some applications, such as agricultural films, high masterbatch let-down-ratios (LDRs) are necessary. This is undesirable. It is an object of the invention to address the above described problems.

It is an object of the present invention to provide a formulation which can be advantageously dosed into a resin at a relatively low LDR. According to a first aspect of the invention, there is provided a liquid formulation comprising a solvent (A) and a hindered amine light stabiliser (A) (referred to herein as HALS (A)), wherein said hindered amine light stabiliser (A) is dissolved in the solvent (A), wherein the sum of the wt% of all hindered amine light stabilisers in said formulation is at least 30 wt%. The sum of the wt% of all hindered amine light stabilisers in said formulation may be at least 35 wt%, preferably at least 39 wt%. In some embodiments, it may be at least 45 wt% or even at least 50 wt%. Said formulation may include 25 to 70 wt% (suitably 35 to 70 wt%, preferably 39 to 65 wt%, more preferably 39 to 50 wt%) of solvent (e.g. comprising or consisting of solvent (A)) and the sum of the wt% of all hindered amine light stabilisers may be in the range 30 to 75wt% (suitably 30 to 65 wt%, preferably 35 to 61 wt%, more preferably 50 to 61 wt%).

Solvent (A) preferably makes up at least 60 wt%, preferably at least 80 wt%, more preferably at least 90 wt% of the total wt% of solvent in said formulation.

Generally, a hindered amine light stabiliser (referred to as a HALS), for example HALS (A), is understood to be a cyclic amine which suitably has some degree of steric hindrance, for example derived from aliphatic substitution on carbon atoms adjacent an amine functional group. A HALS may be an acetylated, N-hydrocarbyloxy-substituted, hydroxy-substituted or N- hydrocarbyloxy-substituted cyclic amine.

Said HALS (A) suitably includes a piparazine or a piperidine moiety. Said HALS (A) preferably includes a moiety of formula I or II.

wherein

G is hydrogen, methyl or a linking atom or group.

Gi and G₂ are hydrogen, methyl, a linking atom or group or together are oxygen ; and G₅ is hydrogen, optionally-substituted alkyl (e.g. optionally-substituted C_1-4 alkyl)) or alkoxy (e.g. of formula -0₆ where G₆ is an optionally-substituted alkyl group such as a C_1-4 alkyl group). HALS containing -OG₆ groups are commercially known as NOR-HALS. They are known to display reduced basicity which make them suitable for applications in which parts containing them are exposed to acidic environments such as for agricultural films. Preferably, G is hydrogen or methyl ; and Gi and G₂ are hydrogen or methyl.

G₅ is preferably a hydrogen atom.

A preferred HALS (A) includes a piperidine moiety. A preferred HALS (A) includes a moiety I referred to above. In moiety I, preferably each G represents a hydrogen atom and and G₂ represent hydrogen atoms. G₅ preferably represents a hydrogen atom. Said HALS (A) preferably include a -(CH₂CH₂)_P- moiety where p is in the range 1 to 10, preferably 1 to 6.

Said HALS (A) may be amorphous. It may be oligomeric. HALS (A) may have a molecular weight of greater than 2000g/mol. Said HALS (A) may be selected from the following materials defined by their CAS Numbers: 106990-43-06, 71878-19-8, 565450-39-7, 106990-43-6, 247243-62-5, 152261 -33-1 , 192268-64-7, 202 483-55-4, 193098-40-7, 193098- 40-7, 106990-43-6 and 65447-77-0. Said HALS (A) may be selected from : Lowilite 19 (from Addivant), Chimassorb 944 (from BASF), Tinuvin NOR 371 (from BASF), Tinuvin 494 (from BASF), Tinuvin XT 200 (from BASF), Uvinul 5050 (from BASF), Chimasorb 2020 (from BASF), Hostavin N30 (from Clariant), Addworks AGC 104 (from Clariant), Cyasorb UV-3529 (from Cytec), Cynergy A430 (from Cytec), Sabostab UV 1 19 (from Sabo) and Sabostab UV 62 (from Sabo).

An especially preferred HALS (A) is CHIMASSORB 944 (CAS No. 71878-1 9-8).

Said HALS (A) has a solubility (in the absence of any other materials) in said solvent (A) at 25 °C of at least 15wt%, preferably at least 25wt%.

Said HALS (A) suitably forms a clear solution on dissolution in said solvent (A) at 25 °C.

Advantageously, since HALS (A) is dissolved in solvent (A), it may initially be presented in any physical form, for example beads, pearls or coarse powders.

Said solvent (A) is preferably polar. It preferably includes ester moieties in combination with saturated hydrocarbons moieties. Said solvent (A) may be selected from the group comprising dialkyl esters of a dicarboxylic acid, triglycerides and ethoxylated dialkyl esters.

Dialkyl esters of a dicarboxylic acid may be of the general formula: R¹-CO-0-(CH₂)_n-0- CO-R² where R¹ and R² are C₆ to d₄ alkyl groups and n = 1 to 8. Preferably, R¹ and R² are C₆ to Cio, alkyl groups and n is preferably 2 to 6. A preferred dialkyl ester of a dicarboxylic acid is bis(2-ethylhexyl)adipate.

Preferred triglycerides are C₇ - C₁₃ triglycerides. Triglycerides may be epoxidized such as in epoxidized soy bean oil.

Preferred ethoxylated dialkyl esters are of the general formula: R³-CO-(OCH₂CH₂ )_n-0- CO-R⁴ where R³ and R⁴ are C₆ to Ci₈ alkyl groups and n = 1 to 10.

Said solvent (A) is preferably a liquid at 10°C. More preferably solvent (A) is a liquid at 0°C. Solvent (A) may have a boiling point of greater than 350°C, preferably greater than 400°C. The boiling point is suitably greater than the melt-processing temperature of a polymeric material into which said liquid formulation is dosed in use. Said solvent (A) may have a viscosity, measured using a Brookfield Viscometer, at 25 °C and at a shear rate of 2.05s^"1 of less than 2000cP, preferably less than ^"I OOOCP.

Said solvent (A) preferably includes carbon, hydrogen and oxygen atoms only. Said solvent (A) preferably does not include a nitrogen atom . Said solvent (A) is suitably not a hindered amine light stabiliser.

Said solvent (A) is preferably resistant to thermal degradation at the temperatures used to melt-process relevant polymeric materials described herein.

Said solvent (A) is preferably soluble or finely dispersed in a polymeric material into which it may be dosed in the method of the third aspect.

In said liquid formulation, the ratio defined at the wt% of said HALS (A) divided by the wt% of said solvent (A) is suitably at least 0.5 and, preferably is at least 0.7. The ratio may be less than 2.5 or less than 2. In one embodiment, said ratio is in the range 0.7 to 1 .6.

Preferably, said solvent (A) and HALS (A) are such that the combination (in the absence of any other material, but at said ratio of the wt% of HALS (A) divided by the wt% of solvent (A) used in the formulation) has a viscosity measured using a Brookfield Viscometer at 25 °C and a shear rate of 2.05s^"1 of less than 1 00,000cP, preferably less than 50,000cP, more preferably less than 25,000cP.

Said liquid formulation may include at least 20 wt%, preferably at least 30 wt%, more preferably at least 35 wt%, of solvent (A). Said liquid formulation may include 60 wt% or less, preferably 53 wt% or less, of solvent (A).

Said liquid formulation may include at least 20 wt%, preferably at least 27 wt%, of said HALS (A). Said formulation may include less than 63 wt%, for example less than 50 wt% of said HALS (A).

Said liquid formulation may, in one embodiment, include only one HALS which is suitably HALS (A) in which case HALS (A) will be present in the formulation to a level of at least 30 wt% (preferably at least 40 wt%) so the wt% of all hindered amine light stabilisers in said formulation is at least 30 wt% (preferably at least 40 wt%) as described. However, in other embodiments, said formulation may include said HALS (A) together with one or more other hindered amine light stabiliser(s) so that the sum of the wt% of all hindered amine light stabilisers in said formulation is at least 30 wt% and is preferably at the higher levels stated herein. Said formulation may have a viscosity measured using a Brookfield Viscometer at 25 °C and a shear rate of 2.05s^"1 of less than 100,000cP, preferably less than 50,000cP and, more preferably, less than 30,000cP. Suitably, therefore, the formulation is pumpable so it can be readily dosed into a polymeric material, as described herein. Said viscosity may be in the range 1 ,000 to 30,000cP, preferably 15,000 to 30,000cP.

In an embodiment (I), the liquid formulation may include said HALS (A) and a hindered amine light stabiliser (B) (herein referred to as "HALS (B)"). Said formulation may include at least 10 wt%, preferably at least 20 wt% of HALS (B). It may include less than 40 wt% or less than 33 wt% of HALS (B).

HALS (B) may be as described for HALS (A). It may be an acetylated, N- hydrocarbyloxy-substituted, hydroxy-substituted or N-hydrocarbyloxy-substituted cyclic amine. Said HALS (B) suitably includes a piparazine or a piperidine moiety. Said HALS (B) preferably includes a moiety of formula I or II.

wherein

G is hydrogen, methyl or a linking atom or group;

G† and G₂ are hydrogen, methyl, a linking atom or group or together are oxygen ; and

G₅ is hydrogen, optionally-substituted alkyl (e.g. optionally-substituted Ci_₄ alkyl)) or alkoxy (e.g. of formula -0₆ where G₆ is an optionally-substituted alkyl group such as a Ci_₄ alkyl group). Preferably, G is hydrogen or methyl ; and and G₂ are hydrogen or methyl.

G₅ is preferably a hydrogen atom. A preferred HALS (B) includes a piperidine moiety. A preferred HALS (B) includes a moiety I referred to above. In moiety I, preferably each G represents a hydrogen atom and Gi and G₂ represent hydrogen atoms. G₅ preferably represents a hydrogen atom. Preferably HALS (B) is crystalline. Preferably HALS (B) is not oligomeric. Preferably

HALS (B) has a molecular weight of less than 10OOg/mol.

Said HALS (B) may be selected from the following materials defined by their CAS Numbers 52829-07-9, 124172-53-8, 64338-1 6-1 , 52829-07-9 and 86403-32-9.

Said HALS (B) may be selected from Tinuvin 770 (from BASF), Uvinul 4050 (from BASF), Hostavin 3051 (from Clariant), TINUVIN 765 and Tinuvin N845PP (from Clariant).

In an embodiment (la), HALS (B) may be a solid, at 25°C, which is dispersed throughout the liquid formulation. In this case, the liquid formulation may comprise 15 to 40 wt% of HALS (A) and 1 5 to 40 wt% of HALS (B) provided the sum of the wt% of HALS (A) and (B) in the liquid formulation is less than 70 wt%, for example less than 65 wt%.

In an embodiment (lb), HALS (B) may be a liquid, at least 25°C, which is mixed with the solvent (A) and HALS (A) suitably to define a homogenous formulation. In this case, the liquid formulation may comprise 15 to 40 wt% of HALS (A) and 15 to 40 wt% of HALS (B) provided the sum of the wt% of HALS (A) and (B) in the liquid formulation is less than 70 wt%, for example less than 65 wt%. The sum of the wt% of solvent (A) and HALS (A) in said liquid formulation is preferably at least 50 wt%, more preferably, at least 59 wt%. Such sum may be up to 1 00 wt%.

The sum of the wt% of solvent (A) and the total wt% of HALS in said formulation is suitably at least 50 wt%, preferably at least 65 wt%, more preferably at least 80 wt%, especially at least 85 wt%. Said sum may be up to 100 wt%.

When the sum of the wt% of solvents (A) and hindered amine light stabilisers is less than 100 wt%, the liquid formulation may include other components which may be selected from anti-oxidants, UV absorbers, slip agents, anti-fog additives, colourants and acid scavengers.

Said liquid formulation preferably includes at least 0.1 wt%, for example at least 0.5 wt% of a pigment (A). It may include less than 2 wt% of pigment (A). Said liquid formulation may include at least 0.1 wt%, for example at least 1 wt% of antioxidant (A). It may include less than 5 wt% of anti-oxidant (A).

In some embodiments, said liquid formulation may include a co-solvent which may have other properties - e.g. antifog or antistatic properties. Co-solvents may be selected from sorbitan monolaurate, sorbitan isostearate, PEG-20 sorbitan monolaurate, PEG-4 sorbitan monolaurate, PEG-20 sorbitan monooleate and mono- and di-esters of glycerol, for example glycerol monooleate. Said formulation suitably includes less than 10 wt%, preferably less than 5 wt% of a co-solvent, for example selected from the aforesaid.

Said liquid formulation may include other additives which have anti-static or anti-fog properties.

In a preferred embodiment, said liquid formulation includes at least 30 wt% (preferably at least 35 wt%) of solvent (A) (especially a said dialkyl ester of a carboxylic acid, for example an adipate such as bis(2-ethylhexyl) adipate)) and the total wt% of hindered amine light stabiliser(s) in the formulation is at least 40 wt% (preferably at least 45 wt%, more preferably at least 50 wt%). The formulation may include at least 0.1 wt% (preferably at least 0.3 wt%) of colourant (preferably pigment). The formulation may include at least 1 wt%, preferably at least 4 wt%, of one or more anti-oxidants in total. Said liquid formulation preferably has a viscosity measured using a Brookfield Viscometer at 25 °C and 2.05s^"1 of less than 50,000cP (preferably less than 25,000cP).

Said formulation preferably does not include a photoinitiator. Said formulation preferably does not include an acetaldehyde scavenger.

According to a second aspect of the invention, there is provided a method of making a liquid formulation, preferably as described in the first aspect, the method comprising: (i) selecting a solvent (A);

(ii) selecting a hindered amine light stabiliser (A) (herein HALS (A)); and

(iii) dissolving the HALS (A) in solvent (A).

Said HALS (A) and solvent (A) may be selected so that in said liquid formulation, the ratio defined at the wt% of said HALS (A) divided by the wt% of said solvent (A) is suitably at least 0.5 and, preferably is at least 0.7. The ratio may be less than 2. In one embodiment, said ratio is in the range 0.7 to 1 .6.

Said HALS (A) and solvent (A) may be as described in the first aspect. Step (iii) is preferably carried out at a temperature of less than 80°C, for example less than 60°C. A true solution comprising solvent (A) and HALS (A) is preferably produced.

Said method may include a further step of contacting the solvent (A) with a HALS (B) suitably as described according to the first aspect. When HALS (B) is a solid, the method may include dispersing HALS (B) in solvent (A) which comprises dissolved HALS (A). Alternatively, when HALS (B) is a liquid, it may be mixed with solvent (A) and HALS (A).

According to a third aspect of the invention, there is provided a method of making a component which comprises a hindered amine light stabiliser, the method comprising:

(i) selecting a liquid formulation according to the first aspect;

(ii) contacting the liquid formulation with a polymeric material; and

(ii) melt processing the polymeric material to define the component.

Said component may be any component which may benefit from light stabilisation by incorporation of a HALS. Said component may be any component which is used outside. Said component may be a sporting item (e.g. a ski boot), garden furniture, artificial turf, roofing material or car part. Said component may be an injection moulded component. Said component may be a sheet or film. In one embodiment, said component may be selected from polypropylene tiles, polyethylene injection parts, polypropylene nonwoven materials and polycarbonate tiles

Said component is preferably an extruded material which is suitably provided in long lengths, for example of greater than 1 m or greater than 10m. Said component may comprise a sheet or film. It preferably comprises a film. The material, for example film, may be less than 50μιτι, preferably less than 200μιτι, thick. It may be at least 10μιτι thick.

When said component is a film, said film may be an agricultural film. Such films may be used in greenhouses or tunnels or as mulch films.

Said polymeric material may comprise any melt-processible polymer which is compatible with the liquid formulation and the components thereof. Said polymeric material preferably comprises a polyolefin. Preferably, said polymeric material comprises a polyethylene or a polypropylene or a copolymer comprising the aforesaid.

Advantageously, the liquid formulation described may be more highly loaded with one or more HALS and may therefore be used at a lower let-down-ratio (LDR) compared to existing formulations which are generally solid masterbatches. Alternatively, the liquid formulations may be used to introduce higher levels of HALS into the polymeric material.

In one embodiment, the LDR used in the method may be less than 5%. It may be less than 3% or less than 2%.

In the method, the liquid formulation is preferably pumped towards a position in which it is contacted with the polymeric material. The liquid formulation may be provided in a receptacle prior to said contact. In the method, the liquid formulation in the receptacle may not be heated to a temperature of greater than 50°C. The liquid formulation in the receptacle is preferably not actively heated. It may be maintained at ambient temperature (e.g. in the range 15 to 30 °C) and may be at ambient temperature immediately before contact with the polymeric material. In the method, the liquid formulation is preferably dosed into the polymeric material so the polymeric material includes less than 2 wt% or less than 1 wt% HALS, in total.

As a result of the use of the liquid formulation described, the component of the third aspect may include residual solvent (A). Thus, in a fourth aspect, there is provided a component, for example as described in the fourth aspect (preferably a film or sheet), which includes at least 0.05 wt%, for example at least 0.1 wt% of solvent (A). It may include less than 3 wt% of solvent (A).

In a preferred embodiment, a film or sheet as described may include at least 0.05 wt%, for example at least 0.1 wt% of solvent (A) for example as described in the first aspect (especially an adipate (e.g. bis(2-ethylhexyl) adipate)). The film may include HALS (A) and, optionally, HALS (B).

The invention extends to a structure, for example an agricultural structure (e.g. which is arranged to protect an agricultural product such as a greenhouse, tunnel or package of an agricultural product such as a mulch film) incorporating a component (e.g. film or sheet) as described in the fourth aspect.

Any aspect of any invention described herein may be combined with any other aspect of any other inventions describe herein mutatis mutandis.

Specific embodiments of the invention will now be described, by way of example.

The following materials are referred to hereinafter. White mineral oil - a liquid oil.

CHIMASORB 944 (Trade Mark) - an oligomeric hindered amine light stabiliser (HALS) of molecular weight 2000-3100 in bead form from BASF.

UVINUL 4050 - a monomeric hindered amine light stabiliser in powder form, having a melting point in the range Ι δδ-Ι ΘΟ (CAS No: 124172-53-8)

HOSTAVIN N30 - an oligomeric HALS (CAS No: 202 483-55-4)

TINUVIN NOR371 - an oligomeric HALS (CAS No:247243-62-1 ) UVINUL 5050H - an oligomeric HALS (CAS No: 1 52261 -33-1 ) CYASORB UV-3529 - an oligomeric HALS (CAS No: 193098-40-7)

TINUVIN 765 -a low molecular weight HALS (CAS No: 41556-26-7) TINUVIN 770 -a low molecular weight HALS (CAS No: 52829-07-9)

TINUVIN 326 - a solid benzotriazole UV absorber

IRGAFOS 168 - a solid phosphate anti-oxidant. IRGANOX 1010 - a solid hindered phenol anti-oxidant.

In the following examples, white mineral oil is used as a carrier in some comparative examples, since it is widely commercially used as a carrier. The formulations described herein are found to be advantageous compared to mineral oil based formulations.

Example 1 (Comparative) - Preparation and assessment of first type of liquid formulation

The components detailed in Table 1 were mixed with a high speed mixer, Cowles blade (25mm), to produce a liquid formulation. The total mixing time was 2 hours, at up to 6500rpm in order to fragment the particles of the two HALS components. The maximum temperature achieved was 77°C. The total wt% of HALS was 60 wt%. Component Initial state of raw material Concentration (wt%)

White mineral oil Liquid 40

CHIMASORB 944 Beads 30

UVINUL 4050 Coarse free-flowing powder 30

Table 1

The viscosity of the liquid formulation was assessed using a rotational rheometer and the following results obtained.

Viscosities (cP) at 25 °C

Shear rate Shear rate Shear rate

0.15 s^"1 2.05 s^"1 1 1 .5 s^"1

768,808 602,008 563,627

Table 2

It will be appreciated that the viscosities noted are very high. Consequently, it is clear that mineral oil is unsuitable as a solvent for liquid formulations containing high loadings of HALS. Example 2 - Preparation and assessment of adipate formulation for comparison with the formulations of Example 1

In a first step, the oligomeric HALS (Chimasorb 944) was dissolved in Di-2- ethylhexyladipate at 50^SC, under agitation, to form a transparent, clear solution, of concentration 43% by weight. In a second step, the appropriate amount of the low molecular weight HALS (Uvinul 4050), very poorly soluble in Di-2-ethylhexyladipate, was added to the solution formed in the first step, in order to achieve the concentrations showed in Table 3. The total amount of HALS was 60 wt%. Uvinul remains mostly as a solid dispersed in the liquid. Table 4 shows viscosity results measured in a rotational rheometer. Viscosities achieved are appropriate for a liquid masterbach, combining the properties of high viscosity at low shear rates, and viscosities at higher shear rates which are low enough for pumping/dosing and spreading over resin pellets. So, with solution technology, it is possible to achieve high concentrations of HALS in a liquid masterbatch, while preserving good rheological properties. Component RM presentation Concentration (%)

Di-2-ethylhexyladipate Liquid 40%

Chimassorb 944 Beads 30%

Uvinul 4050 Coarse free flow powder 30%

Table 3

Table 4

Examples 3 to 6 - Preparation and assessment of a range of adipate-based liquid formulation

Various weights of oligomeric HALS (Chimasorb 944) were dissolved in respective samples of di-2-ethylhexyladipate at 50°C, with agitation, to form in each case, clear solutions. The viscosity of the liquid formulations was assessed using a rotational rheometer and the results detailed in Table 5 were obtained.

Table 5

It will be appreciated from Table 5 that, by providing a solution of the HALS in a solvent, a formulation can be produced having a viscosity which is low enough so the formulations can be pumped and dosed into resins at lower let-down-ratios (LDRs) compared to solid masterbatches.

Examples 7 to 10 -Viscosities of formulations at different temperatures Formulations of CHIMASORB 944 and HOSTAVIN N30 were prepared as described for Examples 3 to 6 and their viscosities assessed at different temperatures. Results are detailed in Table 6.

Table 6

It should be appreciated from Table 6 that a relatively small increase in temperature can facilitate the use of the highly concentrated liquid masterbatches. To take advantage of this, a slightly heated dosing system may be used to introduce the liquid formulations into resin in an extruder.

Examples 1 1 to 18 Other formulations comprising HALS and vehicles were prepared generally as described for Examples 3 to 6 and the viscosities at 20°C assessed. Results are detailed in Table 7.

Table 7

Example 19 - Preparation and assessment of further liquid formulation

A liquid formulation was prepared using the components detailed in Table 8.

Table 8

In a first step of the preparation, the CHIMASORB 944 was dissolved in Di-2- ethylhexyladipate at 50°C, with agitation, to form a clear solution of concentration 43 wt%. In a second step, the appropriate amount of the UVINUL 4050 (which is very poorly soluble was added to the CHIMASORB-containing solution in order to achieve the concentration detailed in Table 8. The total wt% of HALS was 60 wt%. In the liquid formulation, the UVINUL remains mostly as a solid dispersed in liquid. The viscosity of the liquid formulation was assessed as described in Example 2 and the following results obtained.

Table 9

It should be appreciated that the formulation prepared combines the properties of high viscosity at low shear rates and viscosities at high shear rates which are low enough for pumping/dosing and spreading over resin pellets. Thus, the formulation described includes a high concentration of HALS and is appropriate for a liquid masterbatch.

Example 20 - Preparation and assessment of further formulation

A liquid formulation was prepared using the components detailed in Table 10. Component Featu es of raw material Concentration (wt%)

Di-2-ethylhexyladipate Liquid vehicle 40

CHIMASORB 944 Oligomeric HALS in bead form 30

TINUVIN 765 Liquid low molecular weight HALS 30

Table 10

The liquid formulation prepared had a viscosity of 1 1400 cP at 20 °C and 1 1 .5 s^"\

Liquid formulations may be prepared which have high levels of HALS and which include other additives which may be dispersed in solution, as described in Example 21 .

Example 21 - Preparation of HALS solution comprising dispersed solids

A liquid formulation was prepared using the components detailed in Table 1 1 .

Table 1 1

The liquid formulation prepared had a viscosity of 2500cP at 20 °C and 1 1 .5 s

The formulation may be dosed into polyethylene polymer to provide 1 wt% of TINUVIN NOR371 in the polymer. Polyethylene films may be prepared and used in, for example, greenhouses where protection from sulphur and/or chlorine produced may be desirable.

In order to assess light stabilization achieved using liquid formulations described, a comparison was made between such formulations and solid masterbatches as described in Example 22 to 26.

Examples 22 to 26 - Comparison of light stabilization of parts made using liquid or solid masterbatch formulations Respective liquid and solid masterbatch formulations were prepared as described in Table 12, dosed into polypropylene at appropriate let-down-ratios (LDRs) and plaques produced having the wt% HALS detailed in the table. Plaques were introduced into a QUV chamber for 200 hours in accordance with ASTM D4329-05 to assess the degradation by UV light (irradiance 1 .36 W/m² and temperature 70 °C). Results are provided in Table 12 which show the control plaque (Example 22), without additives, has very high degradation, forming a porous surface from which powder can be detached by light scratching. The plaques incorporating HALS remained generally unaffected by the treatment. Thus, the liquid masterbatches are as effective in protecting the polypropylene as the solid masterbatches.

Table 12

Examples 27 to 28 - Examples of other formulations

Following the procedures described above, formulations of respective Examples 27 and 28 described in Tables 13 and 14 were prepared.

Table 14

The formulations can advantageously be dosed into polyolefins.

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.

Claims

1 . A liquid formulation comprising a solvent (A) and a hindered amine light stabiliser (A) (referred to herein as HALS (A)), wherein said hindered amine light stabiliser (A) is dissolved in the solvent (A), wherein the sum of the wt% of all hindered amine light stabilisers in said formulation is at least 30 wt%.

2. A formulation according to claim 1 , wherein the sum of the wt% of all hindered amine light stabilisers in said formulation is at least 35 wt%, preferably at least 39 wt%.

3. A formulation according to claim 1 or claim 2, wherein said formulation includes 25 to 70 wt% of solvent and the sum of the wt% of all hindered amine light stabilisers is in the range 30 to 75 wt%.

4. A formulation according to any preceding claim, wherein solvent (A) makes up at least 60 wt%, preferably at least 90 wt%, of the total wt% of solvent in said formulation.

5. A formulation according to any preceding claim, wherein HALS (A) is an acetylated, N- hydrocarbyloxy-substituted, hydroxy-substituted or N-hydrocarbyloxy-substituted cyclic amine.

6. A formulation according to any preceding claim, wherein HALS (A) is amorphous and/or is oligomeric and/or has a molecular weight of greater than 2000g/mol.

7. A formulation according to any preceding claim, wherein said HALS (A) is selected from the following materials defined by their CAS Numbers: 106990-43-06, 71 878-19-8,

565450-39-7, 106990-43-6, 247243-62-5, 152261 -33-1 , 192268-64-7, 202 483-55-4, 193098- 40-7, 193098-40-7, 1 06990-43-6 and 65447-77-0.

8. A formulation according to any preceding claim, wherein said HALS (A) has a solubility in the absence of any other materials in said solvent (A) at 25°C of at least 15wt%, preferably at least 25wt%.

9. A formulation according to any preceding claim, wherein said solvent (A) includes ester moieties in combination with saturated hydrocarbons moieties.

10. A formulation according to any preceding claim, wherein said solvent (A) is selected from the group comprising dialkyl esters of a dicarboxylic acid, triglycerides and ethoxylated dialkyl esters.

1 1 . A formulation according to claim 10, wherein dialkyi esters of a dicarboxylic acid are of the general formula: R¹-CO-0-(CH₂)_n-0-CO-R² where R¹ and R² are C₆ to C₁₄ alkyl groups and n = 1 to 8; wherein triglycerides are C₇ - Ci₃ triglycerides; and wherein ethoxylated dialkyi esters are of the general formula: R³-CO-(OCH₂CH₂ )_n-0-CO-R⁴ where R³ and R⁴ are C₆ to C₁₈ alkyl groups and n = 1 to 10.

12. A formulation according to any preceding claim, wherein said solvent (A) is a liquid at 1 ^{n q}C and/or has a boiling point of greater than 350 °C and/or a viscosity, measured using a Brookfield Viscometer, at 25°C and at a shear rate of 2.05s^"1 of less than 2000cP.

13. A formulation according to any preceding claim, wherein in said liquid formulation, the ratio defined at the wt% of said HALS (A) divided by the wt% of said solvent (A) is at least 0.5 and is less than 2.5.

14. A formulation according to any preceding claim, wherein said solvent (A) and HALS (A) are such that the combination (in the absence of any other material, but at said ratio of the wt% of HALS (A) divided by the wt% of solvent (A) used in the formulation) has a viscosity measured using a Brookfield Viscometer at 25 °C and a shear rate of 2.05s^"1 of less than 100,000cP, preferably less than 25,000cP.

15. A formulation according to any preceding claim, wherein said liquid formulation includes at least 20 wt% and 60 wt% or less of solvent (A); and at least 20 wt% and less than 63 wt%, of said HALS (A).

16. A formulation according to any preceding claim, wherein said formulation has a viscosity measured using a Brookfield Viscometer at 25 °C and a shear rate of 2.05s^"1 of less than 100,000cP, preferably less than 30,000cP.

17. A formulation according to any preceding claim, wherein the liquid formulation includes said HALS (A) and at least 10 wt% of a hindered amine light stabiliser (B).

18. A formulation according to claim 17, wherein HALS (B) is crystalline and/or has a molecular weight of less than 1 0OOg/mol.

19. A formulation according to claim 17 or claim 18, wherein said HALS (B) is selected from the following materials defined by their CAS Numbers 52829-07-9, 124172-53-8, 64338-16-1 , 52829-07-9 and 86403-32-9.

20. A formulation according to any of claims 17 to 19, wherein the sum of the wt% of solvent (A) and the total wt% of HALS in said formulation is at least 50 wt%, preferably at least 85 wt%.

21 . A formulation according to any preceding claim, wherein said liquid formulation includes at least 30 wt% of solvent (A) (especially a said dialkyl ester of a carboxylic acid, for example an adipate such as bis(2-ethylhexyl) adipate)) and the total wt% of hindered amine light stabiliser(s) in the formulation is at least 40 wt%, wherein said liquid formulation has a viscosity measured using a Brookfield Viscometer at 25 °C and 2.05s^"1 of less than 50,000cP (preferably less than 25, OOOcP).

22. A method of making a liquid formulation according to any preceding claim, the method comprising: (i) selecting a solvent (A);

(ii) selecting a hindered amine light stabiliser (A) (herein HALS (A)); and

(iii) dissolving the HALS (A) in solvent (A).

23. A method according to claim 22, wherein said method includes a further step of contacting the solvent (A) with a HALS (B) as described in any of claims 17 to 20.

24. A method according to claim 23, including dispersing HALS (B) in solvent (A) which comprises dissolved HALS (A).

25. A method of making a component which comprises a hindered amine light stabiliser, the method comprising:

(i) selecting a liquid formulation according to any of claims 1 to 21 ;

(ii) contacting the liquid formulation with a polymeric material; and

(ii) melt processing the polymeric material to define the component.

26. A method according to claim 25, wherein said component is a sheet or film,

27. A method according to claim 25 or claim 26, wherein said polymeric material comprises a polyolefin.

28. A component which includes at least 0.05 wt% of solvent (A); HALS (A) and, optionally, HALS (B).