IL8390A - high-molecular polyethylene suitable for use as plastics and process for its preparation - Google Patents

Description

It has already been proposed to modif by auxiliary catalysts the reaction between aluminium d 3 from In this especially in the presence of nickel or molecular polymerisation products are preferentially It has now been found that by the admixture to aluminium of certain in the form of suitable metal one catalyst systems lead articularly ethylene polymers of true term high polymer polyethylene compounds signates in the following description polyethylenes with molecular weights above preferably above the use of an appropriate catalyst concentration leads of a molecular size even above that which had hitherto been regarded as upper limit of technically available limit is constituted weights of about but this figure is more than an indication of the fact that solutions of such have a viscosity calculated b means of a certain conventional formula fiir second page of a molecula weight of if in connection with the present invention reference is to molecular the intention is always solel to such conventional molecular weights as are determined by measurements of and the question is left open whether or not these figures are really correct as the weights in true sense of the According to the gaseous ethylene is contacted with catalysts of mixtures of and compounds of the metals of the fourth to sixth groups of the periodic including thorium and For one may compounds of molybdenum and with a special preference for the use of salts of uranium and An especially catalyst of the kind according such acetyl and the with aluminium Such a catalyst converts ethylene already under low pressures of than 100 at temperatures below very rapidly into As already stated obtained in accordance the invention are extraordinarily have a softening or point above are completely insoluble in all solvents at room ones among them to a molecular of abou partly dissolve 70 Q onl the a moleeular weight above partly above temperature resistance of the new products is larger than that of When warming the products to temperatures above they keep their colour while the colour of the products changes to gra between resistance of the products to oxidation by atmospheric oxygen is equally high which is extraordinary unchanged until above and in the vicinity the softening point As shown by diagrams the degree of i general erystallinity to abou is frequently eve Of lower magnitudes also From a of view they are stances having having practically no For groups the substances according to the invention have at th most three methyl In the proportion of the groups is substantially lower still and amounts to at the frequentl even below of the substances according the invention have no in contras to the hitherto tearing strength at least 100 2 frequently higher than The tensile strength 2 in the unstretched state is more than 200 in foils orientated by it is up to cm the substances be withou for example between heated to transparent and flexible plates or are also suitable processing by of extrusion or by injection they are in the and can out in this to wires or threads of elasticity such could never yet be with polyethylene of erent Already during the the substances h a remarkable tendency to fibre molten state they may also be into filaments by the usual spinning methods for such as nylon filaments prepared the new polyethylenes may be as for the known manufacture of ver pressures of atmospheres ami have been and as a rule the process has been carried out in the presence of oxygen or peroxides as polymerisation known processes have the further drawback that a relatively proportion 15 to of the ethylene as starting material can be into polyethylene in one single By in the process according to the the ethylene used as material converted to a large extant in on single in the process according to the inventio the need not be as pure as it has to in the known nature the oatalyst produced by the admixture of metal with trlalieyls is not yet in Most probably it essential that in the manufacture of the can be reduced to lower degrees of For in the admixtur of tetravalent zirconium compounds with aluminium a compound of bivalen or trivalent zirconium is the tetravalen sal undergoes a conversion clearly proved by the that th initially colourless salt dissolves in the aluminium trialkyl with a colour while heat is bein special polymerizing effect may be caused by the of the as as by its combination with aluminium the zirconium compound has already a corresponding polymerising effec by since the actio of the catalyst on the ethylene starts already at lower temperatures and occurs more rapidly than the normal reaction of the aluminium trialkyl with polymerisation according to the inventio can be carried out under comparatively pressures of 10 to 100 It is advantageous to perform the process a pressures below 10 A smooth polymerisatio of increased any technically possible are also at room temperature and it is advantageous to carry out process at higher above is not advisable to carry ou at temperatures above as at this temperature catalysts decompose to substantial Instead of containing gas mixtures may processed without in cordance with the obtained by the cracking of ethane or or of petroleum and its or produced by an appropriatel conducted synthesis according opsch and free from other if activity of catalyst and of of the final products obtained depend o metal the conditions of and on the relation of the quantity of the metal compound to the quantity It has been for that when amounts of the containing component of the eatalyst are titanium containing catalys mixtures are more highly active than 6 containing of catalyst can be considerabl by not from a relatively tr bu from an aluminium molecular such as be for combination and it may be advantageous to out operation in presence o there and higher also paraffins at the reaction aromatie halogenated chlorinated dibutyl The lower limit of the proportio in which solvents used is so chose that the reaction mixture can stirred towards en of the the reaction of thus being stirred it 10 to of polyethylene towards the end o the limits merely by profitability of the for titanium tetrachloride allowed t drop a of aluminium in hexane in a molecular proportion of the solution assumes a dark colour solvent such as ethylene may be polymerised without even at atmospheric portion of this mixture is deeply coloured and apparently it tains the same compound in colloidal The respective amounts of catalyst remaining in colloidal dispersion cipitating as solids depend on the conditions of the The catalyst colloidal dispersion of highly reactive and can bette be dosed than the difficultly uble The having to work with the tate can be overcome without difficulty at the beginning uses instead of an aluminium triethyl solution in the solution of a higher aluminium trialkyl has approximately the average composition of aluminium In one obtains a completely homogeneous darkly coloured solution of experiments i which polyethylenes are obtained from ethylene and aluminium trialkyl In this it is possible within oertain limits to the degree of polymerisation by the proper selection of the proportion aluminium It has been found that in the process according to this polyethylene wit a molecular weight higher than a thousands can be obtained with great difficulties which is to be ascribed inter alia to the fact tha for the preparation of very an extremely small proportion of aluminium triethyl would have be for only about of aluminium calculated for the amount ethylene in order to obtain a and in addition they proceed very the amount of catalyst in the total mixture is too the process according to the can be the proportion of to the ethylene used immediate influence on molecular e and these larger amounts then automatically the removal of any impurities present in process to the invention a An especially proportion of aluminium to the defined in about the following If stands for the in which stands for of the 4th or groups of the periodic or n this designates valency of it will he advantageous to 2n to of tri per molecule of the compound the of the metal compounds into Only in the specia of acetyl of the heavy the use of molecular of the combination of another titanium salt the acetyl a proportion of 8 12 molecular amounts of aluminium trialfeyl for 1 molecular of titanium salt will presumably more three amounts of aluminium recommendation to use 12 molecular amounts of gives direction that the polymerisation should allowed act in the of an excess of aluminium excess of aluminium is to counteract action of the impurities frequently present in moisture or are apt te the catalysts and thereby to impair their excess of trialkyl prevents this or reduces the already oxidized or generally removes any impurities i the apt to damage the The lowes limit the amount of eatalyst in proportion the quantity of ethylene used may vary within very wide limits and depends o purity of the If very pure ethylene is an amount o par of catalyst fo 1000 parts ethylene is Of courset higher proportions may be used eve in the case of pure unnecessarily large amounts of catalysts be avoided in order that the further processing may not be more tha If very impure ethylene is as a starting good results may yet be achieved with catalyst amounts of a If solvents are used at all the applies to the purity of the By the quantity of catalyst molecular of the be ma be influenced in that sense tha the degree of polymerisation is the higher smaller the amount of the invention is illustrated by the ollowing Examples to which it is not 20 oc of aluminium are cautiousl admixed with gr of titanium a lively development of hea is solution opaque and an of is poured into an autoclave cc capacity and to 70 gr of ethylene are under the is heated to drops to about 20 atmospheres within 15 mixture is to and excess of ethylene is contents of the autoclave a past consists of a mixture of ethylene with liquid and soluble solid The mixture is triturated methanol and extracted first with methanolio hydrochloric acid and subsequently There gr of an soluble difficultly meltin residue having properties product prepared in accordance with Example 2 of titanium tetrachloride dropped into 40 of aluminium triethyl while ai is b precipitate with lively sel mixture is admixed with 200 cc o hexane whereupon a part of the substance formed precipitates and another part in the The hexane portion is into an autoclave of capacity filled wit nitrogen and is introduce until the pressure has risen to 60 the is temperature rises spontaneously up to and the pressure drops to 25 If now introduction of ethylene under is no repetition of the strong rise temperature can Seve the ethylene pressure though more Altogether batches of ethylene of together gr introduced under pressure into the A er an aggregate time of 65 gr of ethylene blown out of the contents o the autoclave found to a soli dif which had completely absorbed the solvent removed from the autoclave by being broken up in any suitable troduced into methanol and subsequently heated with methanclic After washing of the residue with and 80 gr of difficultly powde can be pressed between heated to 160 to into clearly transparent foils of extraordinarily good narrow ribbon cut from such a foil stretched in cold to abou to times its one observes the characteristic phenomena known frost the of strength o stretched bands m 3 process is at first carried out as described in Example but as a polymerisation stimulant one the precipitate that settles dilutio all this while air is d io further of experiment resembles to a large extent the one described in the 500 cc of liquid paraffin which has been freed air by introducing nitroge and heating to and allowed to is admixed with 58 gr of aluminium trialkyl of the average composition of and then while ring under an atmosphere of of titanium mixture becomes black and no solid precipitate ethylene is introduced at temperature while temperature 8pontaneously rises from to course of half the ethylene vigorously absorbed at a of about gr per Soon after the start of the separation of a difficultly substance om the mixture can be A ter about 5 to the absorption of ethylene mixture is then diluted by the admixture with of 200cc of which makes the mixture easier to then methanol is reaction mixture mains at firs still Only it is iltered with suction in contact with it changes into a bright olive colour occurs first in precipitate that has been off with If washing with the precipitate very slightly heated with acid of about j it I is then washed with methanol and One obtains 40 gr of purel very loose powder upon being has all the properties tha have been Of the experiment One proceeds in accordance solution Of the catalyst in liquid paraf is warmed to about 40 to 50 and then is passed which contains about 10 to of such ca by cracking of course of experiment is essentially it takes abou 10 to 12 hours until amoun of has 6 In the in preceding 6 of 82 gr of triethyl and 24 gr of titaniu tetrachloride are starred with ethylene under a pressure of not more than experiment started at The temperature rises spontaneously to A ter altogether 12 the autoclave the contains a magma that can almost not be stirred an longer and which is up in manner described One about kg of a polyethylene that can immediatel aa a moulding of solid zirconium acetyl acetonate cautiously introduced into of h salt 13 to mixture with 200 of under an atmosphere into an autoclave of mild and having a capacity of 500 altogether 110 of ethylene axe introduced pressure in about 4 introductio of ethylene ao adjusted that each time th initial pressure after heating to about amounts to 90 to 100 autoclave is then shaken at After of ethylene under a drop of the pressure down to to 20 atmospheres can be observed time after about 2 to 3 fter duction under pressure of altogether 110 of the absorption of ethylene xxroceeds only which is apparently to be ascribed fact that a this time the tents of the autoclave have hardened into an immovable mixture of solid polyethylene and hexane and can therefore no longer brought by the stirring this difficulty can be avoided and the ethylene absorption can be one allows small about of ethylene to whereafter autoclave contents consist of a solid soaked ia triturated with filtered with and first heated with hydrochloric acid for the of the metal and the again with By of boiling no substantial amounts of paraffins extracted the being dried at about 100 the polyethylene is a finely grained powder w by being pressed metal plates heated to and subsequent quick is converted In a autoclave having a capacity of 14 6 litres of gr of aluminium triethyl and 10 gr of aoetyl acetonate are mixed one another in an atmosphere of Then the is heated to and ethylene is introduced up to a pressure of about 5 The pressure is maintained this and mixture is stirred for 10 If one then the mixture to cool and the ethylene to and if one opens the it is observed that a colourless has separated in an extraordinarily peculiar form on the stirring and also on the of the The polymer consists of a pile of slightly threads which somewhat recall fibred The can easily be detached from the stirring be washed with and converted the dried 9 20 cc of aluminium triethyl are mixed with 20 of and 2 gr of thorium aoetyl acetonate is into this The acetyl acetonate dissolves and the turns slightly It heats until near to the boiling point of the At the gas is Under an atmosphere of the is poured into an autodave of 500 capacity and further with 180 cc of hexane freed from air by Then introduces gr of under pressure and heats the autoclave to pressure rises temporarily to about 150 but begins to drop again before the autoclave has reached the temperature of The is for forty hours at then allowed to d the small excess pressure still present allowed to 15 contents of autoclave consist a magma of a fibrous polyethylene suspended in organic compounds are decomposed by addition of then mixture is with suction and the solid polyethylene is heated with hydrochloric acid in to the filtration with washing with methanol on 102 gr the polymer at 145 ca be moulded betwee heated into clear foils of extraordinarily mechanical accordance wit the thorium compound mentioned by 2 of By and large the experiment proceeds a and yields a polyethylene having 11 In the same way as in of of turns e mixture is processed the manner described in Example and yields gr of tene and 15 gr of polyethylene well as abou of soluble 2 of chromium acetyl introduced into 20 of aluminium air is While developing hea bu does not in an autoclave of whereafter ethylene is introduced under a pressure of and the clave pressur to about 25 as the is saturated with then one introduces more ethylene under pressure and continues The pressure now drops somewhat more operation is repeated several each a interva 110 gr of ethylene introduced into the autoclave in the course of 24 After 24 the pressure still amounted to At the beginning of the the temperature rose spontaneously to After 24 gr of ethylene was blown then the autoclave opened and its contents at admixed with The contents of the autoclave form a which is out of autoclave filtered thereafter the filter is heated wit methanolio hydrochloric aeid in order to remove the catalyst and the mixture ie obtains gr of a colourless insoluble in organic vents and ca easily b pressed into a between heated metal 20 of trie hyl admixed with gr of tungsten and the mixture is ground in 200 cc of hexane in a 2 catalyst pension is introduced into an autoclave of cc ethylene is made to aet thereon at during 24 under a g pressure of After opening the autoclave 20 ec of aluminium triethyl is admixed with gr of molybdenum acetyl The process continued as scribed in After 24 operation at a ethylene guge pressure of obtains about 5 gr of polyethylene of the kind E A 20 o aluminium triethylene is admixed with gr of tantalum and the mixture is further treated as described Examples and At under an ethylene gauge pressure of 90 one obtains after to 8 gr of 16 20 cc of aluminium triethyl is admixed with 4 gr of tetrabromid the mixture is ground for hours 200 cc of hexane in a ball the ouspension introduced into an autoclave of 500 cc At 60 to under an ethylene gauge pressure of one obtains a ter 24 hours 122 gr o a mixture of 25 cc ethyl and gr of in 200 of hexane is ground As described in the mixture is introduced into an autoclave of 500 After a reaction time of hours at under an ethylene gauge pressure of 60 to 70 obtains 45 gr of 18 By careful hydrolysis of 5 gr of titanium tetrachloride at to one titanium oxyhydrate and with ice shake at three with 100 cc of once with 100 cc of absolute and three times with petroleum and completely dried by filtration with 1 gr of the thus prepared ie suspended in 100 cc of 20 cc of aluminium triethyl at are thereto unde an atmosphere suspension introduced under nitrogen into a hall and ground for thereafter the suspension introduced under nitrogen into an autoclave of 500 cc capacit Under the working conditions i Example 35 gr of polyethylene EXAMPLE 19 from an aqueous solution of zirconium the zirconium is precipitated as oxyhydrate by the careful addition of at and the sediment is iltered as described Example and of zirconium oxyhydrate thus is admixed to 50 ee of aluminium and this mixture i ground for 2 3 hours in 200 cc of hexane in a the conditions described in 53 of lene are with aid o this 20 250 of aluminium l is dissolved in 250 cc of oil and 25 of zirconium is added heated and kept at for 5 hours insufficientOCRQuality

Claims (1)

1. 50 cc of solution oil a dissolved in 100 and 50 a of tetrachloride oil admixed thereto She mixture is for 10 at rooia diluted with liters o ethylene is at a of 1 hou at 60 to of polyethylene is articularly described ascertained said invention and in the same to I declare that I claim A for the preparation of ethylene for as s ethylene contacted with catalysts of and compounds of of the 4th to 6 t of inoliading and especially and A process as claimed in wherein operation is at p below atmospheres preferably pressure and process claimed 1 or wherein the operation is conducted above i 20 in of 1 to 3 the operation is conducted the A process of 1 to 2n weights of aluminium for molecular a of to sub ps of including or n the valency of the fewer g 100 methylene st insufficientOCRQuality