WO1994010113A1

WO1994010113A1 - Condensates of metal compound and polyhydroxy compound and vinyl halide polymers stabilised therewith

Info

Publication number: WO1994010113A1
Application number: PCT/EP1993/002839
Authority: WO
Inventors: Michael Ary Bos; Andrew Joseph Koplick
Original assignee: Unichema Chemie B.V.
Priority date: 1992-10-23
Filing date: 1993-10-13
Publication date: 1994-05-11
Also published as: AU5369794A

Abstract

A process of heat and/or light-stabilising of vinyl halide polymers and stabilised vinyl halide compositions in which as the stabiliser is used the reaction product of a metal compound and a polyol in stoichiometric amounts in the presence of a catalyst at 120-275 °C, preferably 120-230 °C. Preferably, the metal compound is zinc oxide and the polyol is glycerol, pentaerythritol and the like. Also heat and/or light stabilisers comprising the reaction product and the reaction product per se are claimed.

Description

condensates of metal compound and polyhydroxy compound and vinyl halide polymers stabilised therewith

The present invention relates to vinyl halide polymer compositions which have been stabilised against the deteriorating effects of heat and/or light, as well as to a process of producing or forming heat- and/or light- stabilised vinyl halide polymer compositions and to heat- and/or light stabilisers for use in vinyl halide polymer stabilisation.

In general vinyl halide containing resins, such as vinyl chloride homo- and copolymers, have poor resistance to the effects of heat and/or light, and it is well known that in the various fabrication processes which involve exposure to heat the polymer is often discoloured, embrittled and can loose tensile strength. Various proposals which have been made up till now to remedy these deficiencies are discussed below.

Thus it has been proposed in US-A-2,918,451 (Ferro Corp.) to use a physical mixture of (1) a colourless Friedel- Crafts catalyst cation progenitor, such as the oxides and metal soaps of zinc, cadmium, aluminium, antimony and tin, (2) a primary aliphatic polyhydric alcohol having at least three hydroxyl groups of which at least two hydroxyl groups are free and having a boiling point of at least 121°C (250°F) , such as tri ethylolpropane, pentaerythritol, and the like, and (3) a hydrogen chloride acceptor, such as barium oxide. It has been stated in this patent that the primary aliphatic polyhydric alcohols may also be used in the form of their metal alcoholates. Thus a barium pentaerythritolate was formed from 0.36 parts of barium oxide and 2 parts of pentaerythritol, but no reaction conditions have been indicated, so that it is impossible to say what type of compound has been formed.

In US-A-3,948,833 (L. Kacir et al) there has been described

EET an asbestos-vinyl chloride polymer composition with a heat stabiliser system, which comprises 3-20% by weight of the polymer of a metal derivative of a polyhydric alcohol, which in Table I has been described as a calcium-zinc derivative of pentaerythritol. It has also been indicated that the metal derivatives of the polyhydric alcohols are preferably selected from barium, cadmium, zinc, tin, lead, calcium or a combination thereof. Any specific description of the metal derivatives of the polyhydric alcohols is lacking, however, and moreover the heat stabiliser system needs to comprise two additional components, without which the stabiliser system is not effective.

In WO-A-92/01017 (The Ferro Corp.) there has been disclosed a primary heat stabiliser for vinyl halide polymers, particularly PVC, which is formed from an oxide or hydroxide of a Group 2B or 3A metal (preferably zinc oxide) and a polyhydric alcohol (preferably pentaerythritol or PE) . The heat stabiliser is formed by mixing the polyhydric alcohol with the oxide at elevated temperatures, preferably at least about 200°C, more preferably 150°C to 260°C. If zinc oxide and PE are used, the PE is melted and the ZnO is mixed into the molten PE whilst maintaining the temperature above 200°C. From the Example 1 given, the addition of ZnO to molten PE caused vigorous foaming, which subsided after all the ZnO had been added.

It has also been stated that the result of the mixing may include an intimate mixture, a complex, a compound (including a coordination compound) , an adduct, a reaction product, or the like, or any such similar product.

Applicants state, but do not give proof, that there appears to be evidence that the product is a mixture and/or a complex. From the examples given it is clear, however, that not seldom the physical mixture of ZnO and PE performs equally well as the product having the same weight ratio of ZnO and PE, but obtained from the high temperature mixing. No conclusions have been given, however, about the definite

SUBSTITUTESHEET structure of the product ZnO/PE obtained.

In the intermediary document O-A-93/07208 (The Ferro Corp.) again a reaction product of ZnO and PE has been described. In this document the ZnO-PE complex has been indicated to be a reaction product comprising zinc directly or indirectly molecularly bonded to at least one of the atoms of the PE. The molecular bond is a non-organo- metallic molecular bond, which displays an absorption in the infra-red spectra of about 1715-1725 cm^-1. Applicants believe that the ZnO-PE complex may comprise a zinc atom bonded to an oxygen atom which is bonded to a carbon atoms. The compound or complex is prepared in the same way as described in O-A-92/01017 cited herebefore, with the exception that the preparation is now effected in a closed vessel provided with a Dean-Stark trap to collect water which is distilled off. In an analytical summary of the ZnO-PE complex most value is attached to the presence of a peak at 1720 cm^-1 in the infrared spectrum as being specifically related to and essentially characteristic of the complex. Also the solid state ¹³C-NMR shows a peak at 80 ppm, and the X-ray diffraction gives peaks at 5°C and 10°C (which is 19° for the ZnO/PE mixture) . Also secundary ion mass specto etry and electron spectroscopy for chemical analysis show different values for the complex and the physical mixture. In general, more than one mole of water is evolved per mole of ZnO during the complex formation.

Finally, in US-A-3,859,236 (Emery Industries Inc.) it has been proposed to stabilise vinyl halide resins with bivalent metal glyceroxides. These glyceroxides are derived from barium, calcium, cadmium, lead, zinc or tin and are said to have the general formula C₃H₅0₃Me, in which Me is the metal atom. The metal content has been indicated to be 40-50 wt%. The compounds are said to be formed by the reaction of glycerol with a compound of the metal, preferably a metal salt at elevated temperature. The metal

SUBSTITUTESHEET glyceroxides are believed to be complex, high molecular weight, polymeric materials, containing a plurality of -Zn-O- covalent linkages. The zinc and tin glyceroxides are stated to be particularly effective stabilisers for use with vinyl halide polymer resins in an amount of 0.005 to 3 wt% of the metal in the compounded resin.

During investigations of US-A-3,859,236 by the present inventors it has been found that zinc glycerolate prepared from zinc oxide and excess glycerol has a typical hexagonal platelet structure having a substantial two-dimensional extension, but low thickness. Such structures of zinc glycerolate have previously been described in US-A-4,789,701 (R.M. Taylor) and in this specification it has been stated that in PVC preparations the incorporation of zinc glyceroxide at the 2% level showed some improvements against degradation by heat and also that these preparations showed no visible changes after 300h of exposure to UV irridation. Moreover, it has been found that if the metalo-organic polymers are formed by a reaction between a metal compound and a polyhydroxy compound in stoichiometric amounts in the presence of a catalyst at a temperature between 120°C and 275°C, then the resulting metalo-organic polymer has a crystal form (and consequently physical and physico- chemical properties) which is substantially different from that, as far as it has been disclosed in the documents cited above.

It has also been found that if metal-organic polymers are formed, e.g. from zinc oxide and pentaerythritol (PE) according to the present invention, then only one mole of water is lost per mole of ZnO, regardless of the initial molar ratio of the reactants, provided that at least the minimum molar ratio of ZnO to PE is 1:1. Also there is no absorption peak at 1720 cm^-1, but only a broad band at about 1650 cm^-1 in the infrared spectrum. These

SUBSTITUTESHEET observations are in direct contrast to those mentioned in patent specification WO-A-93/07208 (The Ferro Corporation) for the ZnO-PE complex prepared without WO-A-93/07208 (The Ferro Corporation) for the ZnO-PE complex prepared without catalyst. It is therefore believed that the products obtained by the process according to the present invention are novel compounds.

As a matter of fact, if the metalo-organic polymers are formed e.g. from zinc oxide and glycerol according to the present invention, a three-dimensional rosette type crystal is formed. Dependent on the intensity of mixing, the three- dimensional rosette-type particles can exhibit protruding plate-like edges from the main bulk of the particle, if the protruding edges are broken off, then the main bulk of the particle will have a more rounded or weathered form, but it will still exhibit a typical three-dimensional form quite distinct from that of a hexagonal plate structure. Metalo-organic polymers prepared from e.g. zinc oxide and other polyhydroxy compounds (such as pentaerythritol and xylitol) according to the present invention also show a characteristic three-dimensional structure and it has been found that these materials are far superior stabilisers of PVC than those zinc stabilisers previously prepared according to US-A-3,859,236.

Scanning electron micrographs of zinc glycerolate produced from 1 mole of zinc oxide and 1.05 mole of glycerol with and without catalyst (0.02 mole of glacial acetic acid) reveal a three-dimensional rosette structure when glacial acetic acid is used as the catalyst and hexagonal platelets when no catalyst is used.

The metalo-organic polymers having a characteristic three- dimensional form of particles are used to stabilise vinyl halide polymer compositions against the deteriorating effects of heat and/or light.

SUBSTITUTESHEET Therefore the present invention relates to a vinyl halide polymer composition stabilised against the deteriorating effects of heat and/or light, which is characterized by the fact that it comprises a stabilising amount of the reaction product obtained by the reaction between a metal compound and a polyhydroxy compound in stoichiometric amounts in the presence of a catalyst at a temperature between 120°C and 275°C.

The metal compounds are selected from the group consisting of magnesium, calcium, strontium, barium, zinc, cadmium, tin and mixtures thereof. Mixtures of calcium and zinc and of magnesium and zinc are preferred. Preferred single metals are calcium, magnesium, barium, zinc and tin. The molar ratio of zinc, cadmium or tin to the alkaline earth metals may range from about 100:1 to 1:100, preferably from 10:1 to 1:10. If mixtures of zinc and tin compounds are used, the molar ratio of zinc to divalent or tetravalent tin may range from about 100:1 to 1:100, preferably 10:1 to 1:10.

The preferred compounds of these elements are those which decompose into the oxide upon heating in air, such as the oxides, hydroxides, carbonates, beta-diketonates, carboxylates and mixtures thereof.

The polyhydroxy compounds used in the preparation of the metalo-organic polymers according to the present invention comprise at least two reactive hydroxyl groups. Suitable polyhydroxy compounds are selected from the group consisting of the glycols (such as ethylene glycol, propylene glycol, neopentylglycol) , trihydric alcohols (such as glycerol, trimethylolpropane, trimethylolethane, but also partial esters thereof with fatty acids having from 2 to 24 carbon atoms) , tetrahydric alcohols (such as pentaerythritol and its polymers) , pentahydric alcohols (such as xylitol) , hexahydric alcohols (such as mannitol, sorbitol) , polyglycerols, sugar alcohols, sugars and

SUBSTITUTESHEET mixtures of these. The use of glycerol, pentaerythritol and xylitol is preferred.

The compound to be used as a catalyst in the preparation of the metalo-organic polymers preferably is a carboxylic acid or its derivatives. Saturated or unsaturated, aromatic or hydro-aromatic, straight or branched chain, mono- or polycarboxylic acids may be used, such as acetic acid, propionic acid, maleic acid, tartaric acid, oxalic acid, naphthenic acid, benzoic acid, maleic anhydride, acetic anhydride. Alternatively, the catalyst may be chosen from the salts of these acids, such as zinc acetate, calcium acetate, and the like. Acid catalysts containing hetero- atoms may also be used, such as glycine, thioglycolic acid, beta-aminocrotonic acid, ethylenediamine tetra-acetic acid, trifluoro-acetic acid and mixtures thereof.

A further important class of catalysts is derived from sulphonic acid or their acid salts. For instance, methanesulphonic acid, toluene-4-sulphonic acid, trifluoromethanesulphonic acid, fluorosulphonic acid and other perfluoro-organic sulphonic acids and their salts, such as zinc trifluoromethanesulphonate, tin (II) and tin (IV) trifluoromethanesulphonates, and the like.

Catalysis under basic conditions may be carried out with alkali or alkaline earth metals in the presence of beta- diketones such as dibenzoylmethane,stearoylbenzoylmethane, and the like. Also mixtures of catalysts, for instance glacial acetic acid with a beta-diketone, can be used.

The molar ratio of the catalyst to zinc or other metal elements may be in the range 1:10,000 to 1:5, preferably in the range 1:1000 to 1:10.

The metalo-organic polymers to be used as heat and/or light stabiliser for vinyl halide polymer compositions preferably

SHEET are prepared in such a way that they do no exhibit deep or dark colours of themselves and preferably they are non- toxic.

The metal compound, polyhydroxy compound and the catalyst are heated, while stirring, to a temperature in the range of 120°C to 275°C, preferably 120°C to 230°C, most preferably 170°C to 260°C. During heating volatile products may be also distilled off. Through the use of catalysts, it is presumed that the increased reaction rate influences the formation of the three-dimensional rosettes, or other three-dimensional forms, typically 3-8 microns in average size. Although the original three-dimensional rosette structure with protrusions may be broken by milling, it is assumed that the typical shape and size with increased surface area impart the superior stabilising properties to vinyl halide polymer composition. The effective stabilisation and clarity of vinyl halide polymers thus depends on the ultimate average particle size and the characteristic shape of the particles.

When pentaerythritol and xylitol are used with a metal compound, enough water is added to form a paste, which is then heated with constant stirring to about 150°C-170°C in the presence of a catalyst until a homogeneous mixture is formed, after which the temperature is raised to a range of 190°C to 260°C. Optionally, a high boiling hydrocarbon solvent with boiling point in the range of 180°-210°C can also be used in place of water.

The vinyl halide polymers in the present invention are those polymers obtained by the polymerization of vinyl chloride, vinyl bromide, vinylidene chloride and vinylidene bromide, but they may also be copolymers which additionally contain other polymerizable monomers, such as lower alkyl esters, vinyl acetate, vinyl alkyl ethers, acrylic and

B TITUTESHEET methacrylic esters, acrylic acid, methacrylic acid, acrylonitrile and ethacrylonitrile. Homopolymers and copolymers or blends of these homo- and/or copolymers with other polymers, such as butadiene copolymers, olefin copolymers and olefin homopolymers, may be stabilised with the metalo-organic polymers according to the present invention.

The metalo-organic polymers are used as heat and/or light stabilisers in the vinyl halide polymer composition in an effectively stabilising amount, but preferably the amount is from 0.001 to 20 % by weight, most preferably from 0.01 to 10 % by weight of the final polymer composition. Also other known heat and/or light stabilisers may be used together with the metalo-organic polymers according to the present invention. Other known ingredients, such as plasticizers, stabilisers, anti-oxidants, lubricants, pigments, fillers, colorants, antistatic agents, processing and extrusion aids, and mixtures thereof may also be used. Any unreacted polyhydroxy compound may also serve as an auxiliary heat and/or light stabiliser.

The heat and/or light stabilisers according to the present invention may also be applied in vinyl halide polymer dispersions in particularly non-aqueous liquids, such as plasticizers or solvents, in powder coatings, films, sheets, and the like. Furthermore the heat and/or light stabilisers according to the present invention may also be used in homo- and copolymers of alkenes, like ethylene propylene, butylene, and the like.

The present invention also relates to a process of heat- and/or light-stabilising of vinyl halide polymer compositions, in which an effectively stabilising amount of the reaction product obtained by the reaction between a metal compound and a polyhydroxy compound in stoichiometric amounts in the presence of a catalyst at a temperature between 120°C and 275°C is incorporated into the vinyl

EET halide polymer composition.

The present invention also relates to a heat- and/or light stabiliser for use in vinyl halide polymer stabilisation, which comprises the reaction products according to the present invention.

The present invention also relates to shaped products, at least partially consisting of stabilised vinyl halide polymer according to the present invention, or said polymer obtained with the process according to the present invention.

Finally, the present invention relates to the reaction product per se.

The advantages exhibited by metal glycerolates and other metalo-organic polymers, such as metal pentaerythritolates and xylitolates, having diversified three-dimensional structures with large surface area will be further illustrated in the following examples which describe the method of their production and their advantageous use as stabilisers alone or in combination with other known compounding ingredients to produce vinyl chloride resin articles suitable for a wide variety of applications.

Comparative Example A

For the purpose of comparison, zinc glycerolate was prepared without any catalyst at high temperatures according to American Patent US-A-3,859,236. Thus zinc oxide (81g; 1.00 mol) and glycerol (97g; 1.05 mol) were heated to 200-210°C in a beaker for about one hour with constant stirring. After cooling the white mass was washed with ethanol and filtered on a Buchner funnel and dried at 100°C in an oven.

S BSTITUTESHEET Scanning electron micrographs of this sample revealed that platelets were formed and that they were usually stacked in layers forming dense clusters.

Example l

Zinc oxide (81 g; 1.0 mol) and glycerol (97 g; 1.05 mol) were heated to 130-140°C in the presence of glacial acetic acid (lg; 0.02 mol) in a beaker with constant stirring for about 30 minutes. On cooling the contents of the beaker were washed with ethanol (250 ml) , filtered on a Buchner funnel and dried at 100°C in an oven. Scanning electron micrographs of this sample revealed three-dimensional rosette clusters.

Example 2

Zinc oxide (81 g; 1.0 mol) and xylitol (156 g; 1.03 mol) were heated to 190°C in a hydrocarbon solvent in the presence of acetic acid (0.3g; 0.005 mol) for up to 2-3 hrs with constant stirring. The product was filtered, washed with petroleum spirits (b.p. 40-60°C) and dried at 80°C. After pin-milling, 99% of the particles had an average particle size of less than 10 microns.

Example 3

Zinc oxide (81g; 1.0 mol) and pentaerythritol (136.8 g; 1.0 mol) were heated to 180°C in a high boiling hydrocarbon solvent in the presence of acetic acid (0.5 g; 0.008 mol) for about 2-3 hours with constant stirring. On cooling, the product was filtered, dried in air at 80°C, and jet-milled to afford particles having an average size in the range of 5-15 microns.

ET Example 4

Zinc oxide (8.10g; 1.0 mol), pentaerythritol (90.Og; 0.66 mol) and water (18 g) were combined to form a paste whilst heating up to 160°C in the presence of acetic acid (0.5g; 0.008 mol) with constant stirring. After the water was removed, the mixture was held at 160°C for a further 2-3 hours. The dry product was finally jet milled to afford particles having an average size in the range of 5-20 microns.

Example 5

Calcium hydroxide (4.7 kg; 63.44 mol), glycerol (5.88 kg; 63.85 mol) and acetic acid (0.03 kg; 0.5 mol) were stirred in a small Sigma mixer (Trade Mark) whilst being heated to 120-130°C over a period of 1-2 hours. The dry product obtained was then jet-milled to afford particles having an average size in the range of 5-20 microns.

Example 6

Barium hydroxide monohydrate (413 g; 2.18 mol), glycerol (210 g; 2.28 mol) and acetic acid (4.0 g; 0.07 mol) were heated to 130-140°C with constant stirring for about 30 minutes. On cooling, the material was triturated in ethanol, filtered on a Buchner funnel, dried at 80°C to give a buff-coloured product. After jet milling the average particle size was reduced to the range of 5-20 microns.

To demonstrate the heat stability imparted to the resin compositions through the use of the metalo-organic polymers, such as metal glycerolates, and reaction products of zinc oxide with pentaerythritol or xylitol, stabilised sheets of vinyl chloride resin were prepared by blending the additives and milling them into the resin at about 150- 160°C on a conventional two-role mill for about 5-10

SUBSTITUTESHEET minutes. The sheets were removed from the rolls, cooled and cut into strips for testing. The specimens were observed for discolouration and other signs of polymer degradation whilst heating to 170°C.

Each metalo-organic compound stabiliser sample was thoroughly blended in the following formulation (in parts by weight) :

Polyvinylchloride resin (K-value 66) 100.00 Dioctyl phthalate 50.00

Stearic acid 0.50

Metalo-organic compound sample 2.00

Each blend was passed through a two roll mill for 5 minutes at 150-160°C, which formed it into a homogeneous sheet. These sheets were removed from the mill, cooled and cut into strips and placed in a so-called gear-oven (a mechanical convection oven that rotates the hanging strips, thus enabling an even heat treatment for all strips) at 170°C.

The samples were removed from the oven at regular intervals (in this case every 5 minutes) until satisfactory information concerning the heat stability behaviour of the samples was obtained.

The samples were also subjected to the so-called Congo Red test, as described in R. Gachter and H. Muller "Plastics Additives Handbook", Hansen Verlag, Miinchen, W-Germany, 1990, Chapter 4, page 310. An outline of this test is as follows:

a. A small amount of the "Roll Sheet" (as prepared above in the static heat stability evaluation) are shredded. Two grams are placed in a test tube with a small length of Congo Red test paper suspended above it and the test tube blocked with cotton.

B TI ESHEET b. The test tube is immersed in a hot oil bath at 180°C until the Congo Red test paper begins to turn blue. This is then taken as the Congo Red time.

The Congo Red paper turns blue when hydrogen chloride is released from the sample, hydrogen chloride being expelled from the sample during degradation. Therefore, the Congo Red time is an indication of the capacity of the stabiliser to prevent degradation (the longer the C.R. time, the better the stability action) .

The results obtained have been summarized in Table I.

SUBSTITUTESHEET

Table I Static Oven Tests on Milled PVC Samples

CO c

00 O H

H c m

C

X m

1) Metalo-organic compound pin-milled twice before use

More than 99% of the particles had an

2) Ball-milled, super fine material average particle size less than 10 microns 3) Jet-milled 4) Symbols denote the following: l.y. light yellow; l.br. light brown; bl. black; c colourless; d.br. dark brown; br. brown

As a comparison zinc stearate, barium stearate and calcium stearate were used as the heat and/or light stabiliser in

mol, m.p. 255-259°C) were heated in a 1 litre round-bottom

ratio of pentaerythritol to ZnO in the crude product was calculated to be about 2.8.

A mass balance indicated that about 90% of the total reaction products could be accounted for. The amount of zinc in the crude product was found to be 18.3% by weight by titration. The water-insoluble organic residue obtained during dissolution of the sample in dilute HC1 amounted to about 4-

After pin-milling, the particles had an average particle size of about 100 microns. A sample of this material was tested in a formulation suitable for the extrusion of rigid PVC pressure pipe for potable water and was compared to a control formulation containing tribasic lead sulphate.

For analytical purposes 5.8g of the crude product was subjected to sublimation for 6 hrs at 200°C/0.05 mm Hg. It was observed that the material melted or softened at about 190-200°C in the sublimator. The residue after sublimation was found to contain (in % by weight) Zn (26.8), C (25.5), H(7.0). The amount of water-insoluble organic material obtained from the residue after dissolution in HC1 was 4%. The sublimed material (1.27g) was shown to be identical to that of authentic pentaerythritol by infrared spectroscopy. The infrared spectrum of the organic material collected after HC1 dissolution revealed a strong absorption at 1721 cm^-1. An infrared spectrum of the purified material also showed an absorption at 1709 cm^"1,

The ¹³C CPMAS n r spectrum (cross-polarised magic angle- spinning nuclear magnetic resonance) showed two main resonance signals at 57.6 and 49.3 ppm attributable to unreacted pentaerythritol together with weak signals at 80, 65.8 and 39.6 ppm. The X-ray diffractogram (XRD) indicated a new phase at about 5° and 10°, but the lines are not well resolved. ZnO and pentaerythritol were clearly

SUBSTITUTESHEET visible, however.

Example 8 (comparative)

A further comparative example is included in which ZnO and pentaerythrithol in the molar ratio of 1:2 were allowed to react according to O-A-93/07208.

Zinc oxide (32.6g; 0.4 mol) and pentaerythritol (108.9g; 0.8 mol) were heated in the range 250-280°C for about 2.0 hrs under the same conditions as in Example 7. Despite the fact that the reaction was conducted under nitrogen, it was evident that decomposition occurred because of the darker colour of the product compared to the previous example. The reaction mixture was difficult to stir. A vacuum was applied after 2 hours of heating to remove the remaining water present in the product. The total amount of water collected was 24.5g (13.6 mol). This represents 3.4 mol of water per mol of ZnO. An unidentified yellow organic material that was pungent and lachrymatory was also collected with the distilled water. The product was found to contain (in % by weight) Zn (28.8) , C (34.7), 11 (5.6). The amount of water-insoluble organic material after HC1 dissolution was 16%. An infrared spectrum of this material showed a strong absorption at 1717 cm^-1.

The ¹³C CPMAS nmr spectrum displayed a broad unresolved envelope with strong sharp signals due to pentaerythritol at 57.6 and 49.3 ppm, as well as unassigned resonance signals at 69.5, 62.5, 45.7, 39.5 and 34.6 ppm. A signal at 176 ppm was also detected in this sample. The infrared spectrum showed a strong absorption band at 1715 cm^-1.

There was no clear evidence of a new phase in the XRD scan, but the presence of ZnO and pentaerythritol was confirmed.

SUBSTITUTESHEET Example 9

ZnO and pentaerythritol in the molar ratio (1:2) were heated in the presence of p-toluene sulphonic acid. A portion of the product was sublimed and the residue was examined spectroscopically. The results were compared to those from the previous two examples.

ZnO (16.2g; 0.2 mol) and pentaerythritol (54.5g; 0.4 mol) were added to beaker (400 cm³) and heated to 230-260°C in the presence of p-toluene sulphonic acid (0.36g). As the pentaerythritol melted, evolution of water was noticeable and an easily stirred homogeneous reaction mixture was formed. After about 5-10 minutes of stirring the reaction mixture thickened quite suddenly. Heating was discontinued after 20 minutes, but the stirring was continued by hand as steam evolved. On cooling a dry off-white hard crystalline material was formed, which was found to contain 20.7 wt% of zinc by titration.

A portion of the above reaction product (4.56g) was subjected to sublimation (200°C, 0.05 mmHg, 5-6 hrs) and about 0.9g of unreacted pentaerythritol was removed (see further) . The white crystalline residue did not melt or soften at 200°C during sublimation. This behaviour contrasts with the material from Examples 7 and 8. Micro- analysis showed that the material contained (in % by weight): Zn (22.4, 27.5), C (27.7, 24.6), H (5.2, 4.5). The analyses were conducted on two separate samples.

Infrared spectroscopy confirmed the absence of any absorption at 1720 cm^-1 in the residue after sublimation, although a broad feature at about 1650 cm^-1 was present. The sublimed material was shown by infrared spectroscopy to be pentaerythritol.

The ¹³C CPMAS nmr spectrum showed five resonances, two of

SHEET which correspond to unreacted pentaerythritol at 57.4 and 49.4 ppm, the remaining three resonances at 80.2, 65.8 and 46.7 ppm are most likely due to zinc pentaerythritolate. The signals at 80.2 and 65.8 ppm are tentatively assigned to the methylene carbons bonded to the hydroxy group f-CH₂-OH) and methylene carbon atoms bonded through oxygen to zinc (-CH₂-0-Zn) whereas the resonance signal at 46.7 ppm is assigned to the quaternary carbons (- C=) of the pentaerythritol molecules respectively.

X-ray powder diffractograms (XRD) of the sample showed new lines at (d spacings) 14.228, 9.156, 7.131, 5.639, 4.888, 2.712 and 2.25 Angstrom. Both the XRD and ¹³C n r results indicate that unreacted ZnO and pentaerythritol were both present in the sample.

Example 10

To melted pentaerythritol (112g; 0.82 mol) in a 1 litre beaker was added para-toluene sulphonic acid (0.3 g) and ZnO (32.6g; 0.4 mol). To hinder sublimation, a flask with water was placed on top of the beaker to act as a crude condenser. Periodically, condensed water was wiped from the bottom of the flask as the reaction progressed. The temperature of the reaction mixture was kept in the range of 240-270°C for about 20 minutes during which time the reaction medium quickly thickened and on cooling became an off-white hard solid. From the final weight it was estimated that about 1 mol of water per mol of ZnO was lost during the reaction. In a similar experiment carried out in the apparatus described in example 7 it was confirmed that about 1 mol of water was collected for every mol of ZnO when a suitable catalyst is used. Allowances for pentaerythritol losses by sublimation were made. The material was pin-milled to an average particle size of about 200 microns and tested in a formulation suitable for teh extrusion of rigid PVC.

SUBSTITUTESHEET Example 11

To melted pentaerythritol (136.2g; 1 mol) in a 1 litre beaker was added para-toluene sulphonic acid (l.Og) and ZnO (81.4g; 1 mol). After the initial reaction started, the beaker was suspended above the hot-plate and the contents cooled to about 200°C. With continued stirring a white homogeneous reaction mixture formed, that was also easily stirred. After about 20 minutes a thickening occurred. With continued stirring and evolution of H₂0 a dry hard slightly off-white powder was formed. The total reaction time was about 40-50 minutes. It was estimated that about 1 mol of H₂0 was lost for every mol of ZnO. The ¹³C CPMAS nmr spectrum showed three resonance signals at 80.2, 66.1 and 46.8 ppm, most likely due to zinc pentaerythritol and two resonance signals at 57.8 and 49.4 ppm due to unreacted pentaerythritol. The assignment of these resonance signals has been described in Example 9.

The material was pin-milled to an average particle size of about 70 microns and tested in a formulation for the extrusion of rigid PVC.

Example 12

To melted pentaerythritol (56g; 0.41 mol). In a 250 cm³ beaker was added ZnO (16.2g; 0.2 mol) and zinc trifluoromethyl sulphonic acid (0.6g). (The catalyst was prepared by adding trifluoromethyl sulphonic acid to ZnO in stoichometric amounts and removing excess water to form a dry white powder) . After stirring the reaction mixture, water formed during the reaction was removed to give a thick paste that formed a dry white material on cooling. The total reaction time was about 40 minutes and the temperature of the reaction mixture was kept in the range of 220-270°C.

SUBSTITUTESHEET Example 13

ZnO (8.1g; 0.1 mol), trimethylolpropane (28. lg; 0.21 mol) and p-toluene sulphonic acid (0.2g) were heated in a beaker (250 cm³) to about 240-250°C with a magnetic stirrer until the reaction medium thickened. The reactants were heated for a further 15-20 minutes at this temperature and then cooled, dispersed in ethanol, filtered on a Buchner funnel (Whatman No. 1) and dried at 110°C in an oven to give a white powder (10.2g) . The ¹³ C CPMAS nmr spectrum indicated the following ¹³C resonances: 85, 82.7, 81.4, 44.6, 28.5, 10.9 and 8.9 ppm. The resonance signals at about 83 ppm (unresolved triplet) is tentatively assigned to the methylene carbon atoms bonded to a hydroxyl group and through oxygen to zinc (-CH₂-0-Zn) , whereas the singlet at 44.6 ppm is due to the quaternary carbons of the reacted trimethylolpropane. The resonance signals at 28.5 ppm and about 10 ppm are most likely the methylene carbons of the ethyl group and terminal methyl groups, respectively.

Example 14

ZnO (16.2g; 0.2 mol), pentaerythritol (54.5g; 0.4 mol) and trimethylolpropane (13.4g; 0.1 mol) were heated to 180-240°C in a 250 cm³ beaker in the presence of p-toluene sulphonic acid.

Water evolved and the reaction medium thickened. On cooling, the product was dispersed in ethanol and filtered with difficulty through a Buckner funnel (Whatman No. 1) to give an off-white product after drying in an oven. The material was pin-milled to an average particle size of about 100 microns and tested in a formulation for the extrusion of rigid PVC.

SUBSTITUTESHEET Example 15

To partially melted pentaerythritol (28.Og; 0.2 mol) was added ZnO (8.1g; 0.1 mol) and p-toluene sulphonic acid (0.2g) . After the characteristic thickening, the reaction mixture was heated at about 200°C for a further 15 minutes and then stearic acid (14.0g; 0.05 mol, acid number 203.5 mg KOH) was added. Immediately, a phase separation occurred and after stirring the reaction medium again slowly homogenised, as water evolved to give a cream-coloured product. The product was poured while hot into an aluminium tray to cool. The material was pin-milled to give an average particle size of about 50 microns and tested in a formulation for the extrusion of rigid PVC.

Example 16

To melted trimethylolpropane (6.7g; 0.05 mol) was added sorbitol (9.1g; 0.05 mol), ZnO (8.1g; 0.1 mol) and p- toluene sulphonic acid (0.5g). After heating the mixture at about 200-220°C for 15 minutes, the reaction medium thickened. On cooling, the product was dispersed in ethanol and filtered with difficulty through a Buchner funnal (Whatman No. 1) to give a white product, which is quite soft. The material was tested in a formulation for the extrusion of rigid PVC.

Example 17

To melted pentaerythritol (112g; 0.82 mol) in a 500 cm³ beaker was added Sn0₂ (60g; 0.4 mol) and para-toluene sulphonic acid (0.8g). With vigorous stirring a homogenised reaction medium formed, whilst the temperature was maintained at 200-215°C. In about 30 minutes a thick paste formed, which on cooling gave a powder, which appeared slightly grey.

SUBSTITUTESHEET Example 18

To SnO (13.5g; 0.1 mol) was added a large excess of glycerol (46g, 0.5 mol) some Sn(II) trifluoromethyl sulphonate (0.5g) and 0.5g of a beta-diketone (Rhodiastab 50; Trade Mark, ex Rhone-Poulenc, France) . The mixture was heated in the temperature range 200-220°C. After 1-1.5 hrs of heating and stirring a white powder dispersed in glycerol was formed. On cooling, the product was washed with an excess of ethanol and filtered on a Buchner funnel (Whatman No. 1) . After drying at about 110°C the fine hard white crystalline powder was examined by ¹³C solid state nmr spectroscopy. Three resonance signals at 69.1, 64.9 and 60.9 ppm were observed.

Example 19

To melted pentaerythritol (88.5g; 0.65 mol) in a 1 litre beaker was added para-toluene sulphonic acid (0.5g) and CaO (16.8g; 0.3 mol). Because of excessive frothing at temperatures greater than 220°C, the temperature was lowered to about 180°C. After 20 minutes the reaction medium thickened. On cooling an off-white solid formed. The material was pin-milled to an average particle size of about 40 microns and tested in a formulation for the extrusion of rigid PVC.

Example 20

To melted pentaerythritol (68. lg; 0.5 mol) in a 500 cm³ beaker was added aluminium hydroxide (19.5g; 0.25 mol) and para-toluene sulphonic acid (0.3g). As the reaction progressed in the temperature range 220-250°C, water evolved and an easily stirred reaction mixture formed. After about 20-30 minutes, the mixture thickened and on cooling a beige coloured product was formed.

SUBSTITUTESHEET Example 21

In the following two examples other catalysts, such as zinc acetate and zinc acetylacetonate, were used to effect the reaction between ZnO and pentaerythritol.

ZnO (8.1g; 0.1 mol), pentaerythritol (27.2g; 0.2 mol) and zinc acetylacetonate (0.3g) were heated until the pentaerythritol melted and an easily stirred reaction medium resulted. After thickening and cooling a slightly yellow powder formed.

Example 22

ZnO (8.1g; 0.1 mol), pentaerythritol (27.2g; 0.1 mol) and zinc acetate dihydrate (0.5g) were heated and stirred until a homogeneous reaction mixture resulted. After 20-30 minutes of stirring the thickened mixture was left to cool. An off-white powder was formed.

Example 23

To demonstrate the heat stability imparted to the resin compositions through the use of metalo-organic polymers, such as zinc pentaerythritolate, stabilised sheets of vinyl halide chloride resin were prepared by blending the additives and milling them into the resin at 170-175°C for three minutes on a conventional two-roll mill. The sheets were removed from the rolls, cooled and cut into strips for testing. The specimens were observed every 10 minutes for discolouration whilst heating to 190°C in an oven with forced convection.

Each metalo-organic compound stabiliser sample was thoroughly blended in the following formulation (in parts by weight) suitable for the extrusion of rigid PVC.

EET

The results are shown in Table 2 and it can be seen that compounds prepared according to the present invention and used in stabiliser formulations as shown above are superior to those reaction products prepared according to patent application WO-A-93/07208 although the longer term stability of PVC specimens is not as good as those containing tribasic lead sulphate.

Moreover, the stabiliser formulations according to the present invention appeared to result in PVC samples having markedly low water absorption characteristics.

SUBSTITUTESHEET Table 2 - Static oven tests on milled samples suitable for extrusion of rigid PVC

PE= pentaerythritol, TMP= trimethylolpropane

1. Symbols denote the following: 1 (white) , 2 (light yellow) , 3 (yellow) , 4 (light brown) , 5 (brown) , 6 (dark brown) , 7 (light red) , 8 (red) , 9 (grey) , 10 (black) ; samples placed in oven at 190°C

2. Control contains 0.52g of tribasic lead sulphate instead of product from ZnO/pentaerythritol reaction.

3. Samples prepared according to WO-A-93/07208.

4. Heated at 170-175°C for three minutes on two-roll mill.

SHEET

Claims

1. A vinyl halide polymer composition stabilised against the deteriorating effects of heat and/or light, comprising a stabilising amount of the reaction product obtained by the reaction between a metal compound and a polyhydroxy compound in stoichiometric amounts in the presence of a catalyst at a temperature between 120°C and 275°C.

2. A process of heat- and/or light-stabilising of vinyl halide polymer compositions, in which an effectively stabilising amount of the reaction product obtained by the reaction between a metal compound and a polyhydroxy compound in stoichiometric amounts in the presence of a catalyst at a temperature between 120°C and 275°C is incorporated into the vinyl halide polymer composition.

3. A composition according to claim 1 and a process according to claim 2, in which the metal of the metal compound is selected from the group of metals consisting of magnesium, calcium, strontium, barium, zinc, cadmium, tin and mixtures thereof.

4. A composition according to claim 1 and a process according to claim 2, in which the metal of the metal compound is a mixture of zinc and calcium or magnesium.

5. A composition according to claim 1 and a process according to claim 2, in which the metal compound is selected from the group of compounds, which decompose into the oxide upon heating in air.

6. A composition according to claim 1 and a process according to claim 2, in which the metal compound is

SUBSTITUTESHEET selected from the group consisting of oxides, hydroxides, carbonates, beta-diketones, carboxylates and mixtures thereof.

7. A composition according to claim 1 and a process according to claim 2, in which the polyhydroxy compound comprises at least two reactive hydroxyl groups.

8. A composition according to claim l and a process according to claim 2, in which the polyhydroxy compound is selected from the group consisting of glycols, trihydric alcohols, tetrahydric alcohols, pentahydric alcohols, hexahydric alcohols, polyglycerols, sugar alcohols, sugars, and mixtures thereof.

9. A composition according to claim 1 and a process according to claim 2, in which the polyhydroxy compound is selected from the group consisting of glycerol, trimethylolethane, trimethylolpropane, pentaerythritol, polypentaerythritol, xylitol, sorbitol, mannitol, and mixtures thereof.

10. A composition according to claim 1 and a process according to claim 2, in which the polyhydroxy compound is a partial ester of a polyhydric alcohol and a C₂-C₂₄ fatty acid.

11. A composition according to claim 1 and a process according to claim 2, in which the catalyst is selected from the group consisting of sulphonic acids, acid sulphonic acid salts, carboxylic acids, carboxylic acid salts, and mixtures thereof.

12. A composition according to claim 1 and a process

IT T SHEET according to claim 2, in which the catalyst is selected from the group consisting of para-toluene sulphonic acid, trifluoromethane sulphonic acid, the zinc salt of these sulphonic acids, the tin salt of these sulphonic acids, acetic acid, and mixtures thereof.

13. A composition according to claim 1 and a process according to claim 2, in which the reaction is efffected at a temperature between 120°C and 230°C.

14. A composition according to claim 1 and a process according to claim 2, in which the reaction is effected at a temperature between 170°C and 260°C.

15. A composition according to claim 1 and a process according to claim 2, in which in the reaction one mole of water is formed per one mole of metal compound.

16. A composition according to claim 1, comprising from 0.001% to 20% by weight of the total composition of the reaction product.

17. A composition according to claim 1, comprising from 0.01% to 10% by weight of the total composition of the reaction product.

18. A process according to claim 2, in which from 0.001% to 20% by weight based on the total composition of the reaction product is incorporated into the composition.

19. A process according to claim 2, in which from 0.01% to 10% by weight based on the total composition of the reaction product is incorporated into the composition.

SUBSTITUTESHEET

20. A shaped product, at least partially consisting of stabilised vinyl halide polymer according to claims 1 and 3-16, or obtained with the process according to claims 2-13, 17 and 18.

21. A heat and/or light stabiliser for use in vinyl halide polymer stabilisation, which comprises the reaction product formed by the reaction between a metal compound and a polyhydroxy compound in stoichiometric amounts in the presence of a catalyst at a temperature between 120°C and 275°C, said reaction product having a substantially three-dimensional rosette-type crystal form.

22. A stabiliser according to claim 21, in which the metal of the metal compound is selected from the group of metals consisting of magnesium, calcium, strontium, barium, zinc, cadmium, tin and mixtures thereof.

23. A stabiliser according to claim 21, in which the metal of the metal compound is a mixture of zinc and calcium or magnesium.

24. A stabiliser according to claim 21, in which the metal of the metal compound is selected from the group of compounds, which decompose into the oxide upon heating in air.

25. A stabiliser according to claim 21, in which the metal of the metal compound is selected from the group consisting of oxides, hydroxides, carbonates, beta- diketones, carboxylates and mixtures thereof.

26. A stabiliser according to claim 21, in which the polyhydroxy compound comprises at least two reactive hydroxyl groups.

SUBSTITUTESHEET

27. A stabiliser according to claim 21, in which the polyhydroxy compound is selected from the group consisting of glycols, trihydric alcohols, tetrahydric alcohols, pentahydric alcohols, hexahydric alcohols, polyglycerols, sugar alchols, sugars, and mixtures thereof.

28. A stabiliser according to claim 21, in which the polyhydroxy compound is selected from the group consisting of glycerol, trimethylolethane, trimethylolpropane, pentaerythritol, polypentaerythritol, xylitol, sorbitol, mannitol, and mixtures thereof.

29. A stabiliser according to claim 21, in which the polyhydroxy compound is a partial ester of a polyhydric alcohol and a C₂-C_2t fatty acid.

30. A stabiliser according to claim 21, in which the catalyst is selected from the group consisting of sulphonic acids, acid sulphonic acid salts, carboxylic acids, carboxylic acid salts, and mixtures thereof.

31. A stabiliser according to claim 21, in which the catalyst is selected from the group consisting of para-toluene sulphonic acid, trifluoromethane sulphonic acid, the zinc salt of these sulphonic acids, the tin salt of these sulphonic acids, acetic acid, and mixtures thereof.

32. A stabiliser according to claim 21, in which the reaction is effected at a temperature between 120°C and 230°C.

33. A stabiliser according to claim 21, in which the reaction is effected at a temperature between 170°C and 260°C.

SUBSTITUTESHEET

34. A stabiliser according to claim 21, in which in the reaction one mole of water is formed per one mole of metal compound.

35. A stabiliser according to claim 21, in which the three-dimensional rosettes have an average size of 3 to 8 μm.

36. A reaction product obtained by the reaction between a metal compound and a polyhydroxy compound in stoichiometric amounts in the presence of a catalyst at a temperature between 120°C and 275°C.

37. A reaction product according to claim 36, in which the metal of the metal compound is selected from the group of metals consisting of magnesium, calcium, strontium, barium, zinc, cadmium, tin and mixtures thereof.

38. A reaction product according to claim 36, in which the metal of the metal compound is a mixture of zinc and calcium or magnesium.

39. A reaction product according to claim 36, in which the metal of the metal compound is selected from the group of compounds, which decompose into the oxide upon heating in air.

40. A reaction product according to claim 36, in which the metal of the metal compound is selected from the group consisting of oxides, hydroxides, carbonates, beta- diketones, carboxylates and mixtures thereof.

41. A reaction product according to claim 36, in which the polyhydroxy compound comprises at least two reactive hydroxyl groups.

SUBSTITUTESHEET

42. A reaction product according to claim 36, in which the polyhydroxy compound is selected from the group consisting of glycols, trihydric alcohols, tetrahydric alcohols, pentahydric alcohols, hexahydric alcohols, polyglycerols, sugar alcohols, sugars, and mixtures thereof.

43. A reaction product according to claim 36, in which the polyhydroxy compound is selected from the group consisting of glycerol, trimethylolethane, trimethylolpropane, pentaerythritol, polypentaerythritol, xylitol, sorbitol, mannitol, and mixtures thereof.

44. A reaction product according to claim 36, in which the polyhydroxy compound is a partial ester of a polyhydric alcohol and a C₂-C₂₄ fatty acid.

45. A reaction product according to claim 36, in which the catalyst is selected from the group consisting of sulphonic acids, acid sulphonic acid salts, carboxylic acids, carboxylic acid salts, and mixtures thereof.

46. A reaction product according to claim 36, in which the catalyst is selected from the group consisting of para-toluene sulphonic acid, trifluoromethane sulphonic acid, the zinc salt of these sulphonic acids, the tin salt of these sulphonic acids, acetic acid, and mixtures thereof.

47. A reaction product according to claim 36, in which the reaction is efffected at a temperature between 120°C and 230°C.

48. A reaction product according to claim 36, in which the reaction is effected at a temperature between 170°C and 260°C.

SUBSTITUTESHEET

49. The reaction product obtained by the reaction between zinc oxide and pentaerythritol in stoichiometric amounts in the presence of a catalyst selected from the group of p-toluene sulphonic acid, trifluoromethane sulphonic acid, the zinc salt of these sulphonic acids, acetic acid and mixtures thereof at a temperature between 170°C and 275°C, in which in the reaction one mole of water is formed per mole of zinc oxide.

SUBSTITUTESHEET