This invention relates to a process of preparing vesiculated granules of crosslinked carboxylated polyester resin utilising a particular class of non-alkylphenolethoxylate surfactant.

1. Field of the Invention
This invention relates to vesiculated polyester granules and more particularly to a process of preparing such granules utilising a particular class of non-alkylphenolethoxylate surfactant.
2. Disclosure of the Related Art
Opacifiers are important components of paints, having the primary function of scattering light incident on the paint film. How well a paint is able to visually obliterate a surface over which it is applied is referred to as its opacity. Titanium dioxide pigment is traditionally used as the main opacifier and it, together with the polymeric film former (most usually a latex), are the two main contributors to paint formula cost. In the formulation of lowsheen (eggshell) but more particularly flat paints, mineral extender pigments such as calcite, clay or talc are incorporated to reduce specular reflection down to the desired level.
Since mineral extenders are comparatively cheap they may be added at such a level that there is insufficient film former to bind (space fill) all the pigment present. The paint formulator uses the term critical pigment concentration (CPVC) to describe the point where complete space filling can no longer occur. Addition of further quantities of mineral extender therefore leads to the formation of air voids in the film as drying occurs. These voids scatter light in their own right and contribute to paint film opacity thereby allowing an opportunity to reduce the level of titanium dioxide and still achieve acceptable opacity or coverage. The accompanying formula cost saving, however, is at the expense of other paint film properties such as scrub resistance and stain resistance. In the case of stain resistance, the problem is that of stains penetrating into the voids in the film (film porosity).
In order to improve film integrity (reduce film porosity) vesiculated polyester granules were developed which encapsulated the voids within a polyester granule or bead. Although air is not as good as titanium dioxide in scattering light, these vesiculated beads have been successfully used as opacifiers in paints for many years. In addition to reducing the amount of TiO2 required in the paint, the use of vesiculated polyester beads reduces the amount of latex solids required to form a well integrated paint film. The spherical shape and smooth surface of the beads (low specific surface area) combined with their particle size distribution means that less latex is required to provide the level of binding required. The light scattering ability of the beads can be increased by incorporating an inorganic pigment, such as TiO2, into the beads.
It is well known that vesiculated granules of carboxylated unsaturated polyester crosslinked with ethylenically unsaturated monomer can confer advantageous properties on coating compositions in which they are incorporated, and as a result there has been extensive usage of such granules in a variety of applications. The background to the subject is well covered in the literature, for example, in articles by Kershaw (Australian OCCA Proceedings and News, 8 No. 8, 4 (1971)), Lubbock (Australian OCCA Proceedings and News, 11, No. 5, 12 (1974)), Hislop and McGinley (Journal of Coatings Technology, 50 (642), 69 (1978)), and Bierwagen (Congress Book of the XVth FATIPEC Congress, 3E-Activities, Vol. 111, 110 (1980)). A number of patents relating to these granules and their use in coating compositions have also been issued; these including U.S. Pat. Nos. 3,822,224, 3,879,314, 3,891,577, 3,923,704, 3,933,579, 4,137,380 and 4,321,332.
The preferred process of preparation of such granules is now well established. It is a xe2x80x9cdouble emulsionxe2x80x9d process wherein water is first stably dispersed in a solution in polymerisable monomer of a carboxylated unsaturated polyester to give a xe2x80x9cfirst emulsionxe2x80x9d and the first emulsion is itself stably dispersed in water to give a xe2x80x9cdouble emulsionxe2x80x9d.
Free radical polymerisation is then initiated to give vesiculated granules of crosslinked polyester resin. If pigmented vesiculated granules are required, pigment may be dispersed in either or both of the first emulsion components using conventional pigment dispersants.
Of the patents referred to above, U.S. Pat. No. 3,879,314 (Gunning et al.) describes xe2x80x9cdimensionally stablexe2x80x9d vesiculated granules, with U.S. Pat. No. 3,923,704 describing an improved process of preparing these dimensionally stable granules and U.S. Pat. No. 4,321,332 (Beresford and Braun) demonstrates the achievement of dimensional stability without the need for the polyamide bases of Gunning et al. In U.S. Pat. No. 4,321,332, the polyamine required for stabilisation of the first emulsion was replaced by an oxide, hydroxide or weak acid salt of a selected metal cation; in this way, the odour and yellowing effects of the polyamine could be considerably reduced (these granules shall hereinafter be referred to as xe2x80x9coxide granulesxe2x80x9d). Both of these types of granules have been used successfully in coating compositions.
However, it had sometimes been found that when oxide granules were prepared on a large scale that there had been an unacceptably high incidence of xe2x80x9cgritxe2x80x9d particles, that is, aggregates of two or more granules which are formed during large scale production thereof. One cause of this was the coming together and partial coalescence of individual granules prior to curing; on polymerisation initiation, they fuse to give xe2x80x9cgritxe2x80x9d particles. These particles are visible to the naked eye and their presence in coating compositions is highly undesirable as they appear as visible imperfections in the film.
WO84/00764 describes a process for preparing granules using an alkyl phenol containing anionic surfactant. The process described in that specification was said to reduce or completely eradicate the incidence of grit in oxide granules and to achieve opacities higher than could be previously achieved. In fact the surfactant described in WO84/00764 has been found to be particularly useful in ensuring that:
(a) the granules have the correct level, size and size distribution of internal microvoids to maximise light scattering thereby optimising the opacity or coverage of any paint which contains these granules;
(b) the spherical particles have few if any surface imperfections (surface holes) as such imperfections compromise the stain resistance of paints containing the granules;
(c) the granules/beads are sufficiently well stabilised to not aggregate (form grit) to any significant degree during polymerisation; and
(d) the process for making the granules is sufficiently robust to accommodate higher temperatures for formation of the granules prior to polymerisation being initiated (up to 50 EC.). Such higher temperatures lead to higher temperatures of exotherm leading to better levels of conversion of monomer to polymer thus reducing residual odour of the granule slurry. This is described in Australian Patent No. 670363 (ICI Plc).
In addition to the above, the surfactant was effective as a dispersant for pigment in water if that was the chosen route toward preparing the first emulsion as past of a process for making pigmented vesiculated granules.
While the alkylphenol ethoxylate surfactant described in WO84/00764 allowed the consistent production of vesiculated polyester granules with the desired properties, the commercial use of such surfactants has fallen out of favour.
In recent years there has been an increased focus on the toxicity profile of all raw materials used in industrial processes. In particular, and especially in Europe, the use of alkyl phenol based surfactants such as the alkylphenolethoxylates (APE) described in WO84/00764 are being phased out of consumer product formulations. Alkyl phenol surfactants, when they enter waterways, degrade to residues which can be toxic to fish (gill function). In fish, these residues also mimic oestrogen and are said to give rise to hormone malfunction with anatomical consequences in some laboratory test situations. Whether or not these findings could relate to real situations with consequences for humans has not been established. However, the degree of negative publicity, particularly in Europe, has resulted in vigorous programs by consumer product manufacturers to remove APE surfactants from all formulations.
However, the replacement of these surfactants has proven to be particularly difficult for the formulator. The specific factors at play vary according to the formulation, but in broad terms the phenyl group, as part of the hydrophobic (oil compatible) portion of the surfactant molecule, imparts specific anchoring properties (to pigment particles for example) and/or surfactant interfacial spacial arrangement properties. For these reasons it is usually very difficult to replicate the precise balance of formulation properties without the use of these surfactants.
It has now been surprisingly found that a particular class of non-APE surfactant is capable of providing the advantages associated with the previously used APE surfactants.
Accordingly, the present invention provides a process of preparing vesiculated granules of crosslinked carboxylated polyester resin, said process comprising the steps of:
(a) forming a dispersion of particles of a solution in ethylenically unsaturated monomer of a carboxylated unsaturated polyester resin having an acid value of from 5-50 mg KOH/g, the solution also containing water droplets which are dispersed in the presence of a base selected from:
(i) a water-soluble polyamine which contains at least three amine groups per molecule and which has a dissociation constant (pKa value) of 9.5-10.5; and
(ii) a metal oxide, hydroxide or salt wherein the metal cation is chosen from the group consisting of calcium, magnesium, barium, titanium, zinc, lead, strontium and cobalt, the salt being one wherein the pKa value of the conjugate acid of the anion is greater than 2;
the dispersion additionally containing a surfactant which is free of alkylphenol moieties, and
(b) initiating free radical polymerisation to cross-link the polyester and monomer and provide crosslinked, vesiculated granules, wherein:
(i) where a water-soluble polyamine is used, there are present from 0.3-4.0 amine groups per polyester carboxyl group;
(ii) where a metal oxide, hydroxide or salt is used, there is present from 0.8-1.8 equivalents of metal cation per equivalent of polyester carboxyl group; and
(iii) the surfactant comprises a species of the formula (I)
CaH2a+1xe2x80x94Oxe2x80x94(CH2CH2O)bSO3xe2x88x92xe2x80x83xe2x80x83(I)
where a is 6 to 12 and b is 2 to 8.
Preferably a is 8 to 11; and b is preferably from 3 to 5.
Carboxylated unsaturated polyester resins which will crosslink by reaction with unsaturated monomers are well known. Suitable polyester resins are the condensation products of dicarboxylic acids (or their corresponding anhydrides) and dihydric alcohols, polymerisable unsaturation being introduced into the chain by the use of a proportion of ∀,∃-ethylenically unsaturated acid.
The polyester resins from which a selection is made are condensation products of polybasic acids (or the corresponding anhydrides) and dihydric alcohols. Polymerisable unsaturation is introduced into the molecule by the selection of an ∀,∃-ethylenically unsaturated acid, optionally in combination with a saturated acid or anhydride.
Thus suitable acids are, for example: unsaturated aliphatic acids, such as maleic, fumaric and itaconic acids; saturated aliphatic acids, such as malonic, succinic, glutaric, adipic, pimelic, axelaic, tetrahydrophthalic, chlorendic and sebacic acids; and saturated aromatic acids, such as phthalic, isophthalic, terephthalic, tetra-chlorophthalic, trimellitic and trimesic.
Suitable dihydric alcohols are chosen from, for example, ethylene glycol, poly(ethylene glycols) e.g. diethylene glycol, hexane 1, 6-diol, propylene glycol, di-cyclohexanol and neopentyl glycol. Alternatively, the alcohol may be one which initially contained three or more hydroxyl groups, the hydroxyl groups in excess of two optionally being at least in part etherified with, for example, a monohydric alcohol e.g. methanol, ethanol and n-butanol or esterified with a monobasic acid, e.g. benzoic acid, p-tert.-butyl benzoic acid and chain-like aliphatic acids of up to 18 carbon atoms chain length e.g. coconut oil monoglyceride.
The methods by which unsaturated polyesters of this type are formulated and made are well known in the art.
It is essential to the working of the process that the acid value of the polyester lie within certain limits. As disclosed in WO84/00764 it is essential to select polyesters whose acid values lie in the range 5-50 mg KOH/g, preferably 10-25 mg KOH/g and most preferably 15-20 mg KOH/g.
The unsaturated monomer in which the unsaturated polyester resin is dissolved and crosslinked must be essentially water-insoluble. Monomers which have a solubility at 20 EC. of less than 5% (w/w) in water are considered to be suitably water-insoluble for this purpose. A single monomer or a mixture of monomers may be used and in general the monomer will contain only a single polymerisable double bond. However, it is known that polyfunctional monomers, that is, monomers containing more than one polymerisable double bond, may also be used to crosslink unsaturated polyester resins. Such polyfunctional monomers are, however, normally present only as a minor constituent of a mixture of monomers, the major proportion of which is monofunctional monomer. Hence mixtures comprising monomers such as divinyl benzene may be used in the performance of the present invention.
The preferred ethylenically unsaturated monomers for general use in the present invention are selected from styrene, the mixed isomers of methyl styrene commercially available as xe2x80x9cvinyl toluenexe2x80x9d and methylmethacrylate, because of the ease with which they can be copolymerised with the unsaturated polyester resin. For optimum results, it is preferred that the monomer shall comprise at least 50% by weight of styrene.
The choice of monomer is not, however, restricted to the above monomers alone. Bearing in mind the requirements that the total monomer must be essentially insoluble in water and also be a solvent for the unsaturated polyester resin, there may be present in a minor proportion other polymerisable unsaturated monomers to, for example, modify the physical properties of the co-reacted resins. Typical co-monomers are, for example, ethyl acrylate, n-butyl methacrylate, acrylonitrile, and triallyl cyanurate. In general, it has been found that the upper limit of usefulness of such monomers is 10% by weight of the total monomer used. Higher concentrations give granules which are either too brittle or too rubbery to be used effectively in paints.
Optionally a few percent by weight of a non-polymerising organic liquid, e.g. n-butanol or toluene, may be mixed with the monomer to increase the solubility of the polyester resin therein or may be introduced as an incidental part of the process, e.g. in preparing the polyester.
There is included in the dispersions according to the present invention a surfactant which comprises a species of the formula (I):
CaH2a+1xe2x80x94Oxe2x80x94(CH2CH2O)bSO3xe2x88x92xe2x80x83xe2x80x83(I)
where a is 6 to 12 and b is 2 to 8. This surfactant is typically present to the extent of 0.75-7.5% (preferably 3.0-4.5%) by weight of dispersant solids per volume of total granule solids and may be added initially to any of the phases of the dispersion prior to polymerisation.
A counter ion for the species shown above may be selected from any suitable materials. Naturally, it is preferable to avoid those which confer deleterious properties; for example, some metal cations can impart quite strong colours and some organic cations confer strong odours. Counter ions which are suitable for use in the present invention are, for example, NH4+, Mg2+ and K+, with NH4+ being an especially preferred counter ion.
The base used in this invention may be selected from the polyamine bases of the variety described by Gunning in U.S. Pat. Nos. 3,879,314 and 3,923,704, such as diethylene triamine, triethylene tetramine and oligomers of vinyl pyridine or dimethylaminoethylmethacrylate with polyethylene glycol methacrylate or mixtures thereof, or the metal oxide, hydroxide and salt bases described by Beresford in U.S. Pat. No. 4,321,332, being those of the metals Ca, Mg, Ba, Ti, Zn, Pb, Sr and Co, and when the salt is used, the pKa of the conjugate acid of the anion is greater than 2. The entire disclosures of these three patent documents are incorporated herein by reference. It has been found that for the purposes of the present invention, magnesium oxide is the preferred base. When an amine base is used, sufficient amine should be present such that there are present 0.3-4.0, preferably 1.3-3.2 amine groups per polyester carboxyl group. When a metal oxide, hydroxide or salt base is used, sufficient base should be present such that there is present 0.8-1.8 equivalents of metal cation per equivalent of polyester carboxyl group.
When pigmented granules are desired, the pigment may be selected from any suitable pigment known to the art. It has been found that commercial enamel grades of rutile titanium dioxide are the best pigments for our purposes. A large number of these are available and their suitability for use in our process varies according to the nature and size of the coating on the pigment particles. The most suitable pigments for use in a given formulation are best determined by trial and error. It is permissible to use other primary pigments and extenders such as calcite and barytes. The non-APE surfactant (species of formula (I)) described in this invention is also suitable as a dispersant for such pigment in water if that is the chosen route toward preparing the first emulsion as part of a process for making pigmented vesiculated granules.
The preferred method of preparation of granules according to the present invention involves the xe2x80x9cdouble emulsionxe2x80x9d method referred to above. A process of preparing unpigmented vesiculated granules in a xe2x80x9csingle emulsionxe2x80x9d is known. In this process, described by Gillan and Kershaw in U.S. Pat. No. 3,822,224, a carboxylated unsaturated polyester resin is dispersed in water and polymerised, the vesicles forming spontaneously within the dispersed resin globules. It was thought, however, that where pigmentation of the granules was desired, a double emulsion process was still essential for optimum vesiculation and pigment dispersion and utilisation. It has now been found that the present process allows, in some circumstances, the preparation of pigmented vesiculated granules using a single emulsion process. This option is a potentially very valuable one as it offers reduced production times and increased convenience of handling.
The initial stage in the preparation of dimensionally stable granules according to the present invention by the xe2x80x9cdouble emulsionxe2x80x9d process is the emulsification of water into the solution in ethylenically unsaturated monomer of carboxylated unsaturated polyester resin (the solution in ethylenically unsaturated monomer of carboxylated unsaturated polyester resin shall hereinafter be referred to as xe2x80x9cthe polyester solutionxe2x80x9d and the emulsion of water in the polyester solution shall hereinafter be referred to as xe2x80x9cthe first emulsionxe2x80x9d). This is carried out by mechanical agitation which is continued until the viscosity of the emulsion is essentially constant. It has been found that, during this stage, it is essential that the rate of agitation be carefully regulated. The maximum rate of agitation depends on the particular formulation and the type of agitation used, but as a general guide, it has been found that for impeller-type agitators, the maximum permissible impeller tip speed is about 10 meters per second. This speed is somewhat lower than the 15 meters per second disclosed by Gunning in U.S. Pat. No. 3,923,704, but it has been found that for the purpose of the present invention, tip speeds in excess of about 10 meters per second result in inferior granules. It is preferred that the tip speed be kept below about 8 meters per second. The agitation is carried out in the presence of the base (or metal oxide, hydroxide or salt) which may be present in the polyester solution, the water or both. If pigmented granules are required, the pigment may be added at this stage, or it may be added to the water, the polyester solution or both prior to the formation of the first emulsion.
The first emulsion is dispersed in water which contains a stabiliser for the dispersed first emulsion particles and stirred until the desired granule size is achieved. This dispersion is the xe2x80x9cdouble emulsionxe2x80x9d. The stabiliser may be chosen from the wide range of materials known to be suitable for this purpose but it has been found that an especially suitable material is a water soluble partially hydrolysed poly(vinyl acetate) with a molecular weight of about 100,000 and a degree of hydrolysis of 85-90%. As a general guide, it has been found that a concentration of stabiliser of the order of 0.1-2.0% by weight of the total water (vesicular water and continuous phase water) gives satisfactory results. The surfactant may be added at any stage of the process prior to polymerisation and to any phase of the double emulsion.
An increase in the viscosity of the water can often assist in the dispersion of the emulsion; such an increase can be achieved by the addition to the water of a water soluble polymeric thickener. Suitable thickeners are well known to the art and include such compounds as hydroxyethyl cellulose, typically used at a concentration of about 0.1-0.5% by weight of the continuous water phase. The use of a thickener is advantageous as it spreads the shear stress delivered by the stirrer throughout the dispersion, thereby assisting in the formation of granules with a symmetrical particle size distribution. The thickener is also believed to have a stabilising effect.
When the first emulsion is dispersed in water there is believed to be an uptake of water into the granules. This may be due to salt present in the voids. As the voids/water droplets grow they coalesce to produce bigger voids/water droplets within the organic phase. During this process a typical xe2x80x9cwater in oilxe2x80x9d droplet would increase its water content form about 34% on a volume basis to about 70%. This corresponds to a typical increase in void size from about 250 nm to 2500 nm. In view of the water uptake, there is also a thickening effect which is a particularly useful processing characteristic.
The water content of the xe2x80x9cwater in oilxe2x80x9d droplets in the second emulsion is very important. If there is too much water, such as 75%, then the granules formed may have holes on the surface. These holes can lead to reduced stain resistance in the final paint film. If there is too little water, then the voids are too small and the opacity of the granules is reduced. It is known that the surfactant of formula (I) has a role in stabilising the xe2x80x9cwater in oilxe2x80x9d droplets and has an influence on how much and how quickly water is taken up.
Polymerisation of the polyester resin is effected by free radical means. This can be achieved by the use of a free radical initiator such as an organic peroxide or by exposure to a radiation source such as ultra-violet radiation or a radio-active element. When a free radical initiator is used it may be conveniently dissolved in the polyester resin solution before the dispersion of the solution in water or it may be conveniently dissolved in the polyester resin solution before the dispersion of the solution in water or it may be added to the continuous water phase following the formation of the double emulsion.
For plant operational reasons, the currently preferred initiation system is a redox system of diethylene triamine and t-butyl perbenzoate triggered by ferrous ions derived from ferrous sulphate. The peracid ester is added to the organic phase prior to formation of the first emulsion while the amine and ferrous sulphate solution are added to the aqueous continuous phase after the prepolymerised granules have been processed to the correct size.
Following this initiation step, suspension polymerisation proceeds which is accompanied by an exotherm which increases the temperature of the dispersion. The higher the maximum temperature, the better the conversion of monomer to polymer. Normally, the second emulsion is prepared at room temperature (25 EC.). The temperature is then raised to between 35 EC. and 40 EC. by adding warm water (or a mixture of hot and cold water), following which the initiators are added. Polymerisation then commences taking the temperature of the dispersion up to 50 to 55 E. However, performing the polymerisation at a higher temperature can reduce unpleasant odour in the final paint product. Improved results can be obtained by ensuring the dispersion is at 50 E when the initiators are added ensuring a maximum temperature of about 70 EC. is achieved (refer ICI Plc, Australian Patent No. 670363). Also, better conversion can be achieved by performing the polymerisation under a nitrogen blanket, thereby removing inhibition of polymerisation by air.
The aqueous slurry of vesiculated polyester granules thus formed may be used directly in an aqueous latex paint, or it may be dewatered, by any convenient means, for example the method described in U.S. Pat. No. 4,154,923, and subsequently redispersed in an aqueous or non-aqueous medium, or incorporated into a paste, for example, for use as a filler or a putty.
The paint compositions prepared using granules according to the present process are consistently as opaque as those prepared using granules prepared according to the process described in WO84/00764, and more opaque than otherwise identical compositions comprising granules known to the art; this difference is especially marked in paint comparisons with a high pigment volume concentration (PVC).
The granules of the present invention offer the paint formulator considerable latitude: he/she can reformulate a paint to maintain opacity whilst achieving considerable cost savings or he/she can reformulate to achieve a higher degree of opacity and whiteness without adding to the paint formula cost.


The present invention is directed to processes of polymerizing olefin monomers and copolymerizing olefin monomer(s) with functionalized alpha-olefin monomers in the presence of certain late transition metal pyrrolaldimine chelates, especially bidenate

The present invention is directed to organometallic catalysts and catalyst compositions useful in the oligomerization or polymerization of alpha-olefins alone or in combination with functionalized olefins, certain bidentate ligand compounds useful in providing the subject catalysts, processes of forming the bidentate ligand compounds and catalysts therefrom, processes of forming olefin oligomers and polymers utilizing the subject catalysts, and catalyst compositions and the oligomers and polymers formed therefrom.
The polyolefin industry has relied on various catalyst and initiator systems. The polymerization of ethylene and other non-polar 1-olefins has been commonly accomplished using organometallic Ziegler-Natta coordination-type catalysts, chromium catalysts, other early transition metal catalysts as well as free-radical type initiators. Although the array of catalysts available provides different approaches to the manufacture of polyolefins with differing physical and mechanical properties, these catalysts are highly susceptible to a range of substances which poison or deactivate the catalyst""s activity. It is well known that even trace amounts of oxygen, carbon monoxide, acetylene or water causes deactivation. Further, catalyst deactivation is caused by organic compounds having oxygen donor groups such as ethers, esters, alcohols, or ketones. Industrial application of these organometallic catalysts requires careful and elaborate measures to assure the absence of such poisons. Because these catalysts are easily poisoned, they tend to form low molecular weight materials, can not be used to provide copolymerization of ethylene with an oxygenated functional monomer, such as an ester, acid or ether functionalized olefin, and generally may produce highly branched polymer products.
More recently, olefin polymerizaton catalysts have been developed which are less oxophilic than the early transition metal counterparts. For example, U.S. Pat. Nos. 4,310,716; 4,382,153; 4,293,727; 4,301,318; and 4,293,502 each disclose late transition metal (e.g. Ni) complexes which provide low molecular weight oligomers of ethylene. Further, polymerization of ethylene has been successfully shown using complexes based on phosphorus ylide ligands in U.S. Pat. No. 4,537,982 as well as in U.S. Pat. Nos. 4,698,403; 4,716,205; and 4,906,754. These nickel based catalysts formed from P-O bidentate ligands have been shown to provide high activity in the oligomerization and polymerization of ethylene. Still more recently, L. K. Johnson et al in J. Am. Chem. Soc. 1995 117, 6414, reported the formation and use of Pd(II) and Ni(II) based cationic complexes formed from diimine ligands to provide high molecular weight polyolefins. Finally, WO 96/23010 describes a process for the polymerization of olefins using a variety of transition metal complexes of certain diimine bidentate ligands. In many cases the polymerization provided highly branched polyolefins and were not shown to be useful in providing functionalized copolymer products. Further, in those instances where functionalized copolymers were formed, it was shown that the functional groups reside exclusively at the end of chain branches.
Certain processes and cationic nickel (II) catalyst compositions have been described also by L. K. Johnson et al in WO 97/02298. These cationic complexes are described as active for the polymerization of ethylene and other olefins. They require use of an acid of a non-coordinating mono-anion, or some combination of compounds that will generate such acid, in order for the catalyst composition to be rendered active towards olefin polymerization. The present neutral complexes, as well as the use of a Lewis base is not suggested by Johnson et al.
Lxc3x6fgren et al, in Macromolecules 1997, 30, 171-175 describe polymerization of ethylene by cationic zirconium salen bis-chloride complexes with or without a Lewis base (tetrahydrofuran). They show that the catalyst composition exhibits only low levels of activity. There are many references to the deleterious effect of Lewis base toward late transition metal catalyst compositions as well as single-site catalyst compositions of the metallocene type. For example, EP 94/304642 and EP 94/630910 disclose that Lewis base, such as dialkyl ether, substantially terminates olefin polymerization by a single-site catalyst composition composed of a metallocene compound and partially hydrolyzed aluminum alkyl compound (aluminoxane). Additionally, U.S. Pat. No. 5,571,881 and WO 95/14048 indicate that an unsaturated Lewis base, e.g., vinyl ether, either reacts with the cationic late transition metal catalysts to destroy their activity or causes reduction of the resultant polymer molecular weight. It is highly desired to provide a catalyst for the oligomerization and polymerization of olefins, in particular ethylene, which provides a substantially linear (low degree of branching) product. It is also highly desired to provide a nonionic catalyst which can provide the linear polymer product. It is still further desired to provide a nonionic catalyst which is capable of providing a product of high molecular weight which is substantially linear and, optionally, which is capable of promoting copolymerization of olefin and functionalized olefin monomer units.
Finally, it is desired to provide a catalyst composition composed of a non-ionic catalyst in combination with an adjunct agent and/or a Lewis base which is capable of providing a product of high molecular weight which is substantially linear and, optionally, which is capable of promoting copolymerization of olefin and functionalized olefin monomer units.
The present invention is directed to certain late transition metal pyrrolaldimine chelates as olefin oligomerization or polymerization catalysts, to the bidentate ligand compounds of substituted pyrrolaldimine which are precursors for said catalysts, to catalyst compositions composed of said pyrrolaldimine chelates in combination with an adjunct agent and/or a Lewis base, the methods of forming said precursor compounds and said catalysts, and the method of polymerizing olefin monomers, especially ethylene, as well as copolymerization of olefin and functionalized olefin monomers. Each of the above elements of the present invention is fully described herein below.
The present invention provides a process for polymerizing olefin monomers, in particular ethylene, in the presence of catalysts taken from the selected family of pyrrolaldimine late transition metal chelates and to catalyst compositions composed of said pyrrolaldimine chelates in combination with an adjunct agent and/or a Lewis base, to produce olefin oligomers or polyolefins which can be either substantially linear and have a weight average molecular weight of at least 150.
It has been presently found that certain pyrrolaldimine late transition metal chelates can provide catalyst systems for the oligomerization or homopolymerization of ethylene and copolymerization of ethylene and functionalized olefins to provide substantially linear polymer products. The catalyst of the present invention can be represented by the following
wherein
R1 represents a hydrogen atom, C1-C11 alkyl (preferably C1-C5 and most preferably tert-butyl); aryl, such as phenyl, biphenyl, terphenyl, naphthyl, anthracyl, phenanthracyl and the like; substituted aryl wherein the substitution group is selected from C1-C6 alkyl, perfluoroalkyl, nitro, sulfonate, or halo group; arylalkyl, such as toluyl and the like; halo, such as chloro, bromo, and the like; nitro group; sulfonate group or siloxyl (xe2x80x94OSiA3 where A is selected from phenyl or C1-C4 alkyl such as isopropyl or butyl and the like); or a hydrocarbyl terminated oxyhydrocarbylene group, xe2x80x94(BO)zR7, wherein each B independently represents a C1-C4 (preferably C2-C3) alkylene group or an arylene group (preferably phenyl, especially the B group adjacent to the base structure to which R1 is bonded); R7 represents a C1-C11 (preferably a C1-C3) hydrocarbyl group such as an alkyl or an unsubstituted or substituted aryl group, such as phenyl, biphenyl, naphthyl and the like, alone or substituted with one or more C1-C6 alkyl; and z is 1 to 4, R1 is preferably a steric bulky group selected from aryl, substituted aryl or a branched C3-C6 alkyl group and most preferably, phenyl, anthracyl, phenanthracyl, terphenyl or t-butyl:
R2 represents hydrogen atom, aryl, substituted aryl, C1-C11 alkyl, halogen atom or R1 and R2 can, together provide a hydrocarbylene or substituted hydrocarbylene which forms a carbocyclic ring which may be non-aromatic or aromatic; R2 is preferably hydrogen or, taken with R1 as a carbocyclic ring group:
R3 represents hydrogen:
R4 represents hydrogen atom, a C1-C11 alkyl, an aryl group such as a phenyl or a substituted aryl group such as 2,6-dimethylphenyl or the like, and is preferably selected from hydrogen,
R5 represents a C1-C11 alkyl group (preferably a C4-C8 alkyl group) such as methyl, ethyl, propyl, t-butyl, and the like, a cycloalkyl group such as cyclohexyl and the like, an aryl group, such as phenyl, biphenyl, naphthyl or the like or a substituted aryl having one or both ortho positions of the aromatic group (especially the phenyl group) substituted with a C1-C4 alkyl and/or the para position (with respect to the Nxe2x80x94R5 bond) substituted with a hydrogen atom, nitro, trifluoromethyl, halogen atom, methoxy, or C1-C4 alkyl or fused or unfused aryl, sulfonate, or a hydrocarbyl terminated oxyhydrocarbylene group, xe2x80x94(BO)ZR7 as defined in R1 above. R5 is preferably a t-butyl or a cycloalkyl such as adamantyl, or a 2,6-di(C1-C4 alkyl)phenyl group and most preferably 2,6-diisopropyl phenyl or 2,6-diisopropyl-4-nitrophenyl:
R1 and R5 can, together, form an oxyhydrocarbylene chain, e.g., xe2x80x94(BO)mBxe2x80x94 wherein each B independently represents a C1-C3 alkylene group or an arylene group and m is an integer of from 2 to 5 preferably 3-5;
n is an integer of 0 or 1;
R6 represents, when n is 1, an unsubstituted or substituted aromatic group, such as phenyl which is preferably unsubstituted, a C1-C11 alkyl (preferably a C1-C5 alkyl and most preferably methyl), a hydrogen atom or halogen atom (preferably chloro or bromo), or when n is 0, R6 repesents an allyl or substituted allyl group wherein the substitution can be selected from a halogen atom, a nitro group or a sulfonate group:
L represents a coordination ligand such as triphenylphosphine, tri(C1-C6 alkyl) phosphine, tricycloalkyl phosphine, diphenyl alkyl phosphine, dialkyl phenylphosphine, trialkylamine, arylamine such as pyridine, C2-C20 alkene such as octene, decene, dodecene, alkyl and the like, a substituted alkene wherein the substitution group may be selected from a halogen atom (preferably chloro), an ester group, a C1-C4 alkoxy group, an amine group (xe2x80x94NR2 wherein each R is hydrogen, or a C1-C3 alkyl), carboxylic acid or its alkali metal salt, di(C1-C3)alkyl ether, tetrahydrofuran, a nitrile such as acetonitrile and the like:
M represents one of the transition metals, that is a Group VIII or Group IV transition metal selected from Fe, Co, Ni, Ru, Rh, Pd, Os, Ir, Pt in the +2 oxidation state or Ti, Zr, Hf in the +4 oxidation state and preferably a late transition metal selected from iron, cobalt, nickel or palladium and most preferably either nickel or palladium.
The present invention provides a catalyst which contains sterically bulky groups both above and below as well as within the plane of orientation with respect to the transition metal of the complex. It is believed, though not meant to be a limitation of the invention, that the steric and electronic configuration of the presently achieved complex provides the following desired characteristics:
(1) it utilizes late transition metals (preferably Ni or Pd) to provide high resistance to deactivation by oxygenated species;
(2) it contains certain bidentate, chelating ligand groups which are believed to enhance the selectivity-controlling effect in the polymerization of ethylene and of xcex1-olefins;
(3) it contains groups of extreme steric bulk which provide shielding or partial shielding of the axial faces of the transition metal (II) square planar complexes and thereby it is believed, retards associative displacement and chain transfer during the polymerization; and
(4) the steric bulk which is within the plane of the transition metal (II) square planar complex may inhibit chain migration processes and thereby cause substantially linear polymerization.
(5) the steric bulk which is within the plane of the transition metal (II) square planar complex may promote dissociation of the ancillary ligand, L, and thereby result in an increase in the number of active polymerization sites.
The catalysts (I) are most preferably those having bulky substituents, such as aryl as, for example, anthracenyl, phenanthracenyl, or terphenyl and the like, and substituted aryl groups such as 2,6-diisopropylphenyl and the like, in the R1 and/or R5 positions. The substitution group may be a C1-C4 alkyl and/or an electron withdrawing group such as NO2, halogen, sulfonate (SO3xe2x88x92), sulfonyl ester (SO2R), carboxyl (COOxe2x88x92), or perfluoroalkyl group.
The catalyst (I) of the present invention may further contain an ether or polyether group as part of structure of the subject pyrrolaldimine. The incorporation of such group(s) can be made at R1 and/or at R5 or as an oxyhydrocarbylene chain between R1 and R5 such that a hydrocarbon moiety of said oxyhydrocarbylene is directly bonded to the nitrogen atom at R5 and to the ring at R1. Such catalysts provide enhanced catalytic activity over catalyst (I) absent said group(s) and do not require the use of adjunct agent or Lewis base additive, as described herein below.
Synthesis of the precursor ligands can be achieved by reacting the appropriate pyrrole-2-carboxaldehyde (having desired substituent groups on the pyrrole ring) with a primary amine (R5NH2), such as 2,6-diisopropylaniline and the like. The reaction can be carried out in solution with an inert solvent, such as a C1-C5 alcohol (e.g. methanol, ethanol or the like) or aromatic compound (e.g., benzene, toluene or the like). The reaction is preferably carried out at temperatures of from about 15xc2x0 C. to 80xc2x0 C. (most preferably at from 15 to 25xc2x0 C.) for a period of from one to twenty hours (most preferably from 10 to 12 hours). The reaction is carried out at atmospheric pressure and in the presence of a catalytic amount of an organic acid, such as toluenesulfonic acid to provide the pyrrole-2-carboxaldehyde ligand (IV) according to the equation below:
The bidentate ligand (IV) can be deprotonated using a strong alkali metal alkyl, such as a lithium alkyl (e.g., n-butyl Li) to form the alkali metal (e.g., lithium) salt (V). The deprotonation is carried out at low temperatures such as about 0xc2x0 to 30xc2x0 C. (preferably 0xc2x0 to 10xc2x0 C.) at normal atmospheric pressure and in the presence of an inert solvent, such as tetrahydrofuran, dialkyl ether, C5-C10. hydrocarbon, dioxane and the like. The reaction normally is completed in a short period, such as from about 5 to 30 minutes. The lithium salt (V) can then be reacted with a late transition metal coordination compound of the type R6(L)2MY, wherein each R6 and L are as defined above, and Y represents a halogen atom, as for example bis(triphenylphosphine) phenyl nickel chloride, and the like. This reaction may be conducted in an inert solvent, such as tetrahydrofuran, dialkyl ether, C5-C10 hydrocarbon, and the like at temperatures of from about 10 to 90xc2x0 C. (preferably 10xc2x0 to 30xc2x0 C.) for periods of from one to fifteen hours (normally 10-15 hours) to provide catalyst (I) as follows:
In the above, the R1 may be hydrogen but preferably is a bulky group which provides a steric shield of the transition metal""s equatorial face by being well-positioned in the plane of the transition metal complex as well as some bulk in the axial face. For example, R1 is preferably an aryl, such as phenyl, biphenyl, terphenyl, naphthyl, anthracenyl, or phenanthracenyl, a nitro-substituted aryl, or a bulky alkyl, such as a tert-butyl group. Such substituted pyrrole carboxaldehydes (II) are readily formed by formylation of an appropriately substituted pyrrole. This is conventionally accomplished by reacting the substituted pyrrole with an aldehyde source, such as formaldehyde (e.g., paraformaldehyde, 1,3,5-trioxane) in the presence of stannous chloride catalyst according to the procedures described by Casirighi et al in J. Chem. Soc. Perkins Trans. I, 1980, 1862-5, the teachings of which are incorporated herein by reference in its entirety.
As indicated above, R1 may be selected from sterically bulky groups other than hydrocarbyl groups as, for example, siloxane groups. Such substitution can be readily accomplished by using a 5-hydroxy-2-carboxaldehyde pyrrole as the starting material II to form the Schiff base aldimine compound IV. The hydroxyl group can then be converted to a siloxy group by reaction with the appropriate aryl, alkyl or mixed substituted silyl halide as, for example triisopropyl silyl chloride, diphenyl-t-butyl silyl chloride, triphenyl silyl chloride and the like. Deprotonation and reaction with transition metal coordination compound of the type R5(L)2 MY provides the desired catalyst compound I in the manner described above.
As defined above, R1 and R5 may each independently be selected from a hydrocarbyl terminated oxyhydrocarbylene containing group. Such groups may be represented as xe2x80x94(BO)zR7 wherein each B is independently selected from a C1-C4 (preferably a C2-C3) alkylene group or an arylene group and R7 represents a C1-C11 (preferably C1-C3) hydrocarbyl group such as alkyl, an aryl, an alkaryl, or an aralkyl group and z represents an integer of 1 to 4. Such oxyhydrocarbylene group may be made part of compound I by by mono-alkylation of 2-(2-hydroxyphenyl)-pyrrole or the N-protected 2-hydrophenylpyrrole with bromoethyl ether, followed by formayltion of the pyrrole ring adjacent to the nitrogen, followed by imine formation and finally metallation with R6(L)2MY in the manner described previously.
It has been found that substituted pyrrolaldimine complexes (I) of late transition metals described above provide a catalytic composition having catalytic activity for olefin (e.g., ethylene) oligomerization or polymerization and provide substantially linear product having a low degree of branching. These complexes are neutral compounds and, as such do not require the presence of organo aluminum or hydrolyzed organo aluminum compounds or other reducing agent to cause activation of the complex towards olefin insertion reaction and polymerization. However, organo aluminum and hydrolyzed organo aluminum compounds, such as methyl alumoxane or trialkyl aluminum compounds and the like, may be present and are preferably present when R6 is halogen. Compounds I are a new family of complexes of single-site catalysts.
The subject catalysts (I) may be used as the sole catalyst component of the catalyst composition (this is especially acceptable when the bulky group R1 is large such as phenyl, biphenyl, terphenyl, anthracenyl, phenanthracenyl, nitro-substituted aryl or the like) or may be used in combination with an adjunct agent and/or a Lewis base. The adjunct agent comprises known phosphine sponge material capable of facilitating phosphine (ligand L) dissociation and trapping of free phosphine. Such catalyst composition adjunct agents are, for example, bis(cyclooctadiene)-nickel, tris(pentafluorophenyl) boron, 9-borabicyclo[3.3.1]nonane (9-BBN), methyl iodide and the like.
It has unexpectedly been found that the subject catalyst provides an enhanced catalyst composition when combined with a Lewis base as, for example ethers, esters, aldehydes, ketones, alcohols, amides, organo carbonates, organonitro compounds, or mixtures thereof and even water. It is commonly believed that organometallic catalysts should be combined with Lewis acid compounds to provide effective catalyst systems and that water acts as a poison to such catalysts. In contrast to the present unexpected finding, it has been previously deemed important to use conventional single site catalysts, such as metallocene catalysts, in the absence of moisture or other oxygenated compounds in order to provide an effective catalyst system.
The Lewis base additives found useful in forming a catalyst composition with the catalyst of compound I or V comprise ether compounds, such as dialkyl ethers where each alkyl group is independently selected from a C1-C18 alkyl, preferably a C1-C5 alkyl group as, for example, diethyl ether, methyl ethyl ether, diisopropyl ether, ethyl propyl ether, dibutyl ether and the like; vinyl ethers such as ethyl vinyl ether and the like; aryl ethers as, for example, dibenzyl ether, diphenyl ether, dinaphthyl ether and the like, mixed ethers as, for example, amyl phenyl ether, methyl benzohydryl ether, benzyl phenyl ether, anisole, phenetole and the like. The ether additive may also be selected from cyclic ethers as, for example, tetrahydrofuran, dioxane-1,4, dioxane-1,3, crown ethers such as 18-crown-6, 14-crown-5, 12-crown-4 and the like as well as polyethers such as dimethyoxyethane, diglyme, triglyme, pentaglyme or polyoxyalkylenes as, for example, polyoxyethylene (preferably lower molecular weight polymers which are miscible in the polymerization solvent used).
The above ethers, especially the alkyl and/or aryl group containing ethers and cyclic ethers described above, and most preferably dialkyl ether (e.g., diethyl ether) and low molecular weight polyethers (e.g., dimethyoxyethane) have been found to be effective solvents or co-solvents for use in the polymerization process when the subject catalyst of compound I or compound V is used, as described herein below.
The Lewis base may be selected from an organic ester represented by the formula
wherein each R9 is independently selected from a C1-C11 alkyl group, preferably a C1-C5 alkyl group as, for example, ethyl acetate, propyl acetate, hexyl acetate, ethyl butyrate, propyl butyrate, ethyl caproate, ethyl caprylate, ethyl laurate and the like.
Further, aldehydes and ketones have been found useful as a Lewis base additive in forming the subject catalyst composition. They may be represented by the formula
wherein R10 represents a C1-C12 hydrocarbyl selected from unsubstituted or substituted (e.g., carbonyl) alkyl, aryl, alkaryl or aralkyl groups and R11 represents a hydrogen atom or an R10 group, which is independently selected. For example, the aldehyde or ketone may be selected from acetone, propanone, butyrone, 4-heptanone, 2,4-pentanedione and the like, as well as cyclic ketones such as cyclohexanone, 1,4-cyclohexanedione and the like, or an aldehyde such as acetaldehyde, capraldehyde, valeraldehyde and the like.
Still further, an alcohol can be used as the Lewis base additive in forming the subject catalyst composition. They may be selected from monohydric or polyhydric alcohols including, for example, alcohols having hydrocarbyl moiety composed of a C1-C12 (preferably C1-C3) alkyl, aryl (e.g., phenyl or benzyl), alkaryl and aralkyl groups. Examples of such alcohols include methanol, ethanol, propanol, isopropanol, butanol, t-butanol, 2-pentanol, 3-hexanol, glycol, 1,2,3-propanetriol, phenol, phenethyl alcohol, para-methyl phenol and the like.
Amides can be used as the Lewis base additive in forming the subject catalyst composition. The amides may be represented by the formula
wherein R12 and R13 each independently represent a C1-C11 hydrocarbyl, R14 represents hydrogen or a C1-C11 hydrocarbyl. R13 and R14 are, preferably, independently selected from a C1-C3 alkyl group.
Nitroalkanes and nitroaromatics have also been found to be useful as a Lewis base additive in forming the subject catalyst composition. The nitroalkanes may be a mono (preferred) or poly nitro compound formed with a C1-C11 (preferably a C1-C3) alkyl group. The aromatic nitro should be a mono nitro compound such as nitrobenzene and the like.
It has been unexpectedly found that the subject catalyst composition may contain small amounts of water and that the presence of water does not destroy the activity of the catalyst of the subject invention. Thus, unlike most organometallic catalysts useful in olefin polymerization, the presently described catalyst can be used in the presence of small amounts of moisture to provide a catalyst composition which can remain active in the polymerization or oligomerization of olefins or mixtures of olefins and a functional olefin monomer(s).
The amount of the Lewis base (except water) additive can be substantially any amount desired with from 100 to 104 times the amount of compound I or V on a molar base being preferred and, most preferred, from 101 to 101 times the molar amount of catalyst when ether is the Lewis base used and from 100 to 102 times the molar amount of catalyst with respect to other Lewis bases. In the case of water, the molar ratio of water to catalyst can range from 0 to about 102, preferably, from 0 to 101.
This invention concerns processes for making polymers, comprising, contacting the subject catalyst composition with one or more selected olefins or cycloolefins, alone or optionally with a functional xcex1-olefin such as a carboxylic acid of the formula CH2xe2x95x90CH(CH2)mCOOH, a carboxylic acid ester of the formula CH2xe2x95x90CH(CH2)mCO2R7 or CH2xe2x95x90CHOCOR7, an alkyl vinyl ether of the formula CH2xe2x95x90CH(CH2)mOR7, vinyl ketones of the formula CH2xe2x95x90CH(CH2)mC(O)R7 , a vinyl alcohol of the formula CH2xe2x95x90CH(CH2)mOH, or a vinyl amine of the formula CH2xe2x80x94CH (CH2)mNR82, wherein m is an integer of 0 to 10 and R7 is a C1-C10 hydrocarbyl group, aryl or substituted aryl group (preferably methyl) and R8 is independently selected from hydrogen or an R7 group; a functional cycloolefin, such as functionalized norbornene wherein the functional group is an ester, alcohol, carboxylic acid, halogen atom, primary, secondary or tertiary amine group or the like; or unsaturated dicarboxylic acid anhydride or carbon monoxide or the like and other selected monomers, such as vinyl halides. The subject catalyst composition is composed of the subject transition metal containing compound (I) described above or a combination of compound (V) and transition metal complex, as described herein below. The xe2x80x9cpolymerization processxe2x80x9d described herein (and the polymers made therein) is defined as a process which produces a polymer or oligomer with a weight average molecular weight (Mw) of at least about 150, preferably at least about 1000.
The subject catalysts may generally be written as
wherein each symbol R1, R2, R3, R4, R5, R6, L, and M are defined above. Preferably M is Ni(II) or Pd(II).
Alternately, the catalytic polymerization of the present invention can be carried by contacting one or more selected olefins or cycloolefins alone or optionally with a functional olefin monomer, as described above with a catalyst composition composed of one or more bidentate ligand (V) described above in combination with a transition metal (M) organic complex. The ligand (V) and complex should be used in about a 1:1 molar ratio. In a preferred embodiment of the present invention, the bidentate ligand V is combined with a transition metal organic complex of the formula R6(L)2MY in about a 1:1 molar ratio in the presence of olefin and/or cycloolefin alone or optionally with a functional olefin monomer. The catalyst composition composed of ligand (V) and transition metal organic complex may further contain a phosphine sponge and/or Lewis base additive, such as those described above, or an organo aluminum or hydrolyzed organo aluminum compound or mixtures thereof as described above with respect to catalyst compositions composed of compound (I) which have a halogen as R6.
In all catalysts and precursor bidentate ligands, described herein, it is preferred that R1 and R5 are each independently a sterically bulky hydrocarbyl. In one form it is especially preferred that R1 and R5 are each independently aryl or substituted aryl groups. In another form, it is preferred that R1 and/or R5 be independently selected from a hydrocarbyl terminated oxyhydrocarbylene containing group, as described above. It is preferred that when R5 is a substituted aryl the 4 position of the aryl (with respect to the N-bond) be either hydrogen or nitro.
When using I or V as a catalyst, it is preferred that R2, R3 and R4 are hydrogen or methyl, unless R2 is, when taken together with R1 , a C4-C10 carbocyclic group which may or may not be aromatic. It is also preferred that either or both R1 and R5 are biphenyl, terphenyl, anthracenyl, phenanthracenyl, 2,6-diisopropylphenyl, 2,6-dimethylphenyl, 2,6-diethylphenyl, 4-methylphenyl, 2-isopropyl-6-methylphenyl, phenyl, 2,4,6-trimethylphenyl, 2-t-butylphenyl, 2-t-butyl-6-methylphenyl, 2,6-diisopropyl-4-nitrophenyl, and 10-nitroanthracenyl.
The structure of the ligand associated with compound I or compound V may influence the polymer microstructure and polymer molecular weight. For example, it is preferred that R1 be a bulky aryl or substituted aryl group. Complexes with R1 of this type generally produce higher molecular weight and more linear polymer product for any given set of conditions.
The catalyst or catalyst composition of I or V with the phosphine sponge adjunct or organo aluminum compound adjunct or with the Lewis base additive or mixtures of adjunct and Lewis base, when optionally used, are contacted, usually in a liquid phase, with ethylene or other alpha-olefin (RCHxe2x95x90CH2), and/or 4-vinylcyclohexane, 4-vinylcyclohexene, cyclopentene, cyclobutene, substituted norbornene, or norbornene. The liquid phase may include a compound added just as a solvent and/or may include the monomer(s) itself and/or may comprise the Lewis base (especially an ether compound) in the liquid phase at reaction conditions. When an adjunct is used, the molar ratio of adjunct to compound I or V is from about 0.001:1 to 15:1, preferably about 0.01:1 to about 8:1 and most preferably from 0.1:1 to 3:1. The temperature at which the polymerization is carried out is from about xe2x88x92100xc2x0 C. to about +200xc2x0C., preferably about xe2x88x9220xc2x0C. to about +100xc2x0 C. and most preferably between about 0xc2x0 C. and 90xc2x0C. All ranges of temperatures between xe2x88x92100 and +200xc2x0C. being covered by this teaching. The pressure at which the polymerization is carried out is not critical, atmospheric pressure to about 100 MPa, or more, being a suitable range. The pressure may affect the yield, molecular weight and linearity of the polyolefin produced, with increased pressure providing higher molecular weight, more linear oligomer or polymer product.
Preferred alpha-olefins and cyclic olefins in the polymerization are one or more of ethylene, propylene, 1-butene, 2-butene, 1-hexene, 1-octene, 1-pentene, 1-tetradecene, norbornene, and cyclopentene, with ethylene, propylene, cyclopentene and norbornene being more preferred. Ethylene (alone as a monomer) is especially preferred.
The polymerization may be run in the presence of various liquids. The solvent in which the polymerization may be conducted can be selected from (i) the monomer(s), per se or (ii) any organic compound which is liquid under the reaction conditions and is substantially inert to the reactants and product, or (iii) a Lewis base additive (except water which, when used, should be present in limited amounts) which is liquid under the reaction conditions, or mixtures thereof. Particularly preferred are aprotic organic liquids or organic ethers or mixtures thereof. The catalyst system, monomer(s), and polymer may be soluble or insoluble in these liquids, but obviously these liquids should not prevent the polymerization from occurring. Suitable liquids include alkanes, cycloalkanes, halogenated hydrocarbons, ethers, halogenated aromatic hydrocarbons and aromatic hydrocarbons. Specific useful solvents include hexane, heptane, toluene, xylenes, benzene, methylene chloride, ethyl ether, dimethoxyethane, tetrahydrofuran and crown ethers.
The catalyst compositions of the present invention cause polymerization of one or more alpha-olefin, with functional olefins such as those described herein above. When carbon monoxide is used as a comonomer, it forms alternating copolymers with the various alpha-olefins. The polymerization to form the alternating copolymers is carried out with both CO and the olefin simultaneously present in the process mixture, and in the presence of the present catalyst composition.
The catalyst of the present invention may also be supported on a solid material (as opposed to just being added as a suspended solid or in solution), for instance on silica gel, zeolites, crosslinked organic polymers, such as styrene-divinylbenzene copolymer and the likes thereof. By supported is meant that the catalyst may simply be carried physically on the surface of the solid support, may be adsorbed, or may be carried by the support by other means.
In many of the polymerizations, certain general trends may occur, although for all of these trends there are exceptions. Pressure of the monomers (especially gaseous monomers such as ethylene) has an effect on the polymerizations in many instances. Higher pressure often reduces branching and extends polymer chain length, especially in ethylene containing polymers. Temperature also affects these polymerizations. Higher temperature usually increases branching.
In general, the period of time during which the catalyst of compound I or the catalyst composition formed from compound V, remains active is influenced by the particular ligand structure, polymerization temperature, or type of Lewis base present. Catalyst lifetime is long when Lewis base such as ether is present, co-catalyst adjunct is absent, and R1 is a bulky aryl or substituted aryl group.
When the polymer product of the present invention is a copolymer of functionalized group containing monomer, the functional group may be further used to cross-link the polymer. For example, when copolymers of an olefinic carboxylic acid or olefinic ester and an alpha-olefin are made, they may be crosslinked by various methods known in the art, depending on the specific monomers used to make the polymer. For instance, carboxyl or ester containing polymers may be crosslinked by reaction with diamines or with diisocyanates to form bisamides. The carboxyl groups may also be neutralized with a monovalent or divalent metal containing base (e.g., NaOH, CaO) to form ionomeric or pseudo-crosslinked polyolefin copolymer.
The resultant polymers formed according to the present invention, especially those of ethylene homo or copolymers may have varying degrees of branching in the polymer. Branching may be determined by NMR spectroscopy (see the Examples for details), and this analysis can determine the total number of branches, the branching distribution and to some extent the length of the branches. Herein the amount of branching is expressed as the number of branches per 1000 of the total methylene (xe2x80x94CH2xe2x80x94) groups in the polymers, with one exception. Methylene groups that are in an ester grouping, i.e., xe2x80x94CO2R; a ketone group, i.e., xe2x80x94C(O)R are not counted as part of the 1000 methylenes. The polymers formed with the aid of the present catalyst have low branching of from about 10 to 150 branches per 1000, and normally from about 20 to 120 branches per 1000, for example, ethylene homopolymers have a branch content of about 0 to about 150 branches per 1000 methylene groups, preferably about 5 to about 100 and most preferably about 3 to about 70 branches per 1000 methylene groups. These branches do not include polymer end groups.
The polymers formed by the present invention may be mixed with various additives normally added to elastomers and thermoplastics [see EPSE (below), vol. 14, p. 327-410] which teaching is incorporated herein by reference. For instance reinforcing, non-reinforcing and conductive fillers, such as carbon black, glass fiber, minerals such as silica, clay, mica and talc, glass spheres, barium sulfate, zinc oxide, carbon fiber, and aramid fiber or fibrids, may be used. Antioxidants, antiozonants, pigments, dyes, slip agents, antifog agents, antiblock agents, delusterants, or compounds to promote crosslinking may be added. Plasticizers such as various hydrocarbon oils may also be used.
The polymers formed by the present invention may be used for one or more of the applications listed below. In some cases a reference is given which discusses such uses for polymers in general. All of these references are hereby included by reference. For the references, xe2x80x9cUxe2x80x9d refers to W. Gerhartz, et al., Ed., Ullmann""s Encyclopedia of Industrial Chemistry, 5th Ed. VCH Verlagsgesellschaft mBH, Weinheim, for which the volume and page number are given, xe2x80x9cECT3xe2x80x9d refers to the H. F. Mark, et al., Ed., Kirk-Othmer Encyclopedia of Chemical Technology, 4th Ed., John Wiley and Sons, New York, xe2x80x9cECT4xe2x80x9d refers to the J. I. Kroschwitz, et al., Ed., Kirk-Othmer Encyclopedia of Chemical Technology, 4th Ed., John Wiley and Sons, New York, for which the volume and page number are given. xe2x80x9cEPSTxe2x80x9d refers to H. F. Mark, et al., Ed., Encyclopedia of Polymer Science and Technology, 1st Ed., John Wiley and Sons, New York, for which the volume and page number are given, xe2x80x9cEPSExe2x80x9d refers to H. F. Mark, et al., Ed., Encyclopedia of Polymer Science and Engineering, 2nd Ed., John Wiley and Sons, New York, for which volume and page numbers are given, and xe2x80x9cPMxe2x80x9d refers to J. A. Brydson, ed., Plastics Materials, 5th Ed., Butterworth-Heinemann, Oxford, UK, 1989, and the page is given. In these uses, a polyethylene, polypropylene and a copolymer of ethylene and propylene are preferred.
1. The polyolefins herein are especially useful in blown film applications because of their particular Theological properties (EPSE, vol. 7, p. 88-106). It is preferred that these polymers have some crystallinity.
2. The polymers are useful for blown or cast films or as sheet (see EPSE, vol. 7 p. 88-106; ECT4, vol. 11, p 843-856; PM, p. 252 and p. 432ff). The films may be single layer or multilayer, the multilayer films may include other polymers, adhesives, etc. For packaging the films may be stretch-wrap, shrink-wrap or cling wrap and may be heat sealable. The films are useful for many applications such as packaging foods or liquids, geomembranes and pond liners. It is preferred that these polymers have some crystallinity.
3. Extruded films or coextruded films may be formed from these polymers, and these films may be treated, for example by uniaxial or biaxial orientation after crosslinking by actinic radiation, especially electron beam irradiation. Such extruded films are useful for packaging of various sorts. The extruded films may also be laminated to other films using procedures known to those skilled in the art. The laminated films are also useful for packaging of various sorts.
4. The polymers, particularly the elastomers, may be used as tougheners for other polyolefins such as polypropylene and polyethylene.
5. Tackifiers for low strength adhesives (U, vol. Al, p 235-236) are a use for these polymers. Elastomers and/or relatively low molecular weight polymers are preferred.
6. An oil additive for smoke suppression in single-stroke gasoline engines is another use. Elastomeric polymers are preferred.
7. The polymers are useful as base resins for hot melt adhesives (U, vol. Al, p 233-234), pressure sensitive adhesives (U, vol. Al, p 235-236) or solvent applied adhesives. Thermoplastics are preferred for hot melt adhesives.
8. Base polymer for caulking of various kinds is another use. An elastomer is preferred. Lower molecular weight polymers are often used.
9. Wire insulation and jacketing may be made from any of the polyolefins (see EPSE, vol. 17, p. 828-842). In the case of elastomers it may be preferable to crosslink the polymer after the insulation or jacketing is formed, for example by free radicals.

Catalyst compositions and processes for olefin oligomerization and polymerization

Abstract: or in the presence of a combination of a transition metal in its zero valence and a pyrrolaldimine represented by the formula:

Abstract: wherein each R1, R2, R3, R4, R5, R6, M and L are defined in the specification herein below.


A method and system of tracking devices uses imaging and optionally tags. Tracking is performed when the identification information associated with the devices are initially received and exposed towards a scanning bar in an enclosure. This scanning bar scans at one or more predetermined intervals the one or more devices in the enclosure of hardware. The system for tracking devices includes an enclosure capable of receiving one or more devices positioned to expose identification information related to each device and a scanning bar movably coupled to the enclosure that passes over each of the one or more devices and captures images of the identification information exposed by each of the one or more devices.

It has become increasingly difficult to track computing equipment and other devices in datacenters and other locales. Each device is typically installed in an enclosure and many enclosures occupy a floor or multiple floors in the typical large datacenter. Monitoring the devices in each enclosure is possible but physically locating the devices can be challenging. Even if the devices are installed in a datacenter according to a map or other layout, it is likely that this layout will change over time as systems grow, devices are replaced and reconfigurations of the systems are made.
Quickly identifying the devices becomes a more complex task than previously due to volume of devices and computers in a location. With racks and racks of equipment in a computer room, it may be necessary to scan the devices in each rack manually to identify a particular device. This may not only be time consuming but futile in the event a person is searching for a device that unbeknownst to him or her has been previously moved from one location to another.
Efforts have been made to create devices with RFID tags built into the device to improve or automate locating a device. Unfortunately, this requires that every device has an RFID tag and the tag is compatible with the tag reader being used for all of the other tagged devices in an enclosure or location. Further, it also requires that the tag on the device operate correctly otherwise a malfunctioning tag or reader may make it appear that a device has disappeared or at least is not in the expected location. Those legacy devices missing an RFID tag need an alternate solution to accurately track the devices and provide a robust asset tracking capability.
Like reference numbers and designations in the various drawings indicate like elements.

Imaging method and system for tracking devices

Hewlett-Packard Development Company, L.P.