IL26638A

IL26638A - Granulation of water-insoluble or slightly soluble pulverulent substances

Info

Publication number: IL26638A
Application number: IL2663866A
Authority: IL
Original assignee: Baerlocher Chem
Priority date: 1965-12-14
Filing date: 1966-10-04
Publication date: 1970-12-24
Also published as: GB1178846A; JPS4814778B1; CH523715A; BE691192A; NL6617285A; BE744929R; DE1542068A1; DE1669783A1; CH492478A; AT280958B; NL6617761A; NL145582B; SE370706B; AT282557B; CS166212B2; DE1542067A1; CH485804A; FR1505023A; DE1279658B; AT283278B

Description

■i IMPROVEMENTS IN OR RELATING TO THE GRANULATION OP VJATER-INSOLUBLE OR SLIGHTLY SOLUBLE PULVERULENT SUBSTANCES Many chemicals utilised for technical purposes are used in the form of a solid powder. Thus, for example, water-insoluble metal salts and pigments are to a great extent used in a solid form in the plastics industry. These salts, in particular the metal soaps serve often as lubricants, hydrophobating agents, preserving agents, stabilising agents and for many other purposes. Likewise sulfur in powder form is used in particular for vulcanisation or for combatting insects, vermins a'nd the like. i Metal salts, in particular soaps, can be prepared by the melting process by heating of a fatty acid with a metal oxide (e.g. stearic acid with zinc oxide), as the result of which process the salt is mostly obtained in the form of a paste which cannot easily he dosed. such When t5KF oxides or hydroxides are reacted with such e= acids in a solvent, f.i. cadmium oxide or the so called Hamburg^/ the latter is for economical reasons recovered and recycled to the process. Vhen high-boiling solvents, e.g. softening agents, are utilised, dust-free metal soap pastes are directly obtained, which may, for example, be utilised for the stabilisation of chlorinated polymerisates.

The precipitation process which is most commoniy used for the preparation of metal soaps yields mostly extremely light voluminuous products, This method 6s often utilised for the preparation of stearates and palmitates of aluminium, calcium, lead, zinc and magnesium. First the fatty acid is converted into the water-soluble salts of sodium, potassium o ammonium. These water-soluble salts are then reatted with' water-insoluble metal soaps. Thus, sodium stearate can be reacted with calcium chloride to yield calcium stearate and sodium chloride.

The precipitated metal soap is then centrifuged or filtered off and freed from all contaminations by continuous washing and finally dried, Yater-insoluble salts can generally also, besides by the above double, conversion in suitable solvents with subsequent isolation of the insoluble product, be obtained by hydrolysis of a water-soluble metal salt, £.i. by conversion of water-soluble lead acetate with fatty acid to produce a basic lead soap, or by the conversion of a water-insoluble metal salt into another water-insoluble salt of the same metal in the presence of a catalytically effective acid. Thus, for example, poly-basic lead sulfates and lead phosphates may be prepared by the reaction of lead oxide suspended in water with sulfuric acid and phosphoric acid, respectively, in the presence of a catalyst.

Most metal salts, nearly all metal soaps and pigments, being extremely fine and voluminuous powders, incline to give off dust. When these products are used, such dust has very unpleasant effects, in particular since the most important of these water-insoluble products are poisonous.

Particularly, when basic lead salts, including lead soaps, are being used, poisonings of the persons handling these again and again. Other industrial important salts are not less poisonous, Thus,, cadmium- and hazardous barium dalts and soaps are physiologically very ^L¾=¾¾-ptirfct?-; risks regarding ¾«. >* There, e cist also physiological =e*m«M^&a-»-b¾&«s at the resorption of zinc, strontium, copper, chromium, nercury, tin and soaps and salts of many other metal3. Moreover, it is difficult to admix basic soaps of some metals, in particular basic salts of lead, mainly the poly-basic lead sulfates, lead phosphites, lead fumarates, phthalates, salicylates and other basic lead compounds, homogeneously and sufficiently quick with other masses, particularly masses of plastics and to disperse them evenly.

Even with physiologically safe, substances the formation of dust is an extremely annoying problem for the persons handling these ' substances. , It is very difficult to keep the installations clean and dust-free and t.o dose the products exactly. Moreover, many of these water-insoluble or slightly caking soluble substances . incline to the ir TO"¾=fc=o^-ar-ooiit¾i«gg=, and are not suitable to bo used in , automatic dosing installations.

There have been made efforts to overcome the above difficulties in that substances, such as motal salts,-soaps and pigments have been converted into paetes.with the aid of products which are utilised in any case in the end product, ».. e.g., in the plastics industry with softening agents and in he rubber industry with mineral oils. One has also tried to admix the metal, soaps and metal salts with small amounts, of softening agents in order to bind the fine dust.

The supply in paste form has the drawback that large amounts of softening agents have to be transported also, thus burdening the freight balance. These pastes, being mostly viscous, can be weighed and dosed only with difficulty.

Moreover, the softening agent or the mineral oil content restricts the general application.

The preparation of the so-called "slightly dust-creating" products has not yielded satisfactory results. A small amount of softening agent is not effective and a larger amount thereof yields agglomerates which are distributable only with difficulties* Hard lumps are formed frequently, when powdery substances stick together. This causes difficulties when the products are to be utilised. It has also been tried to convert such products into tablets or to granulate them in any other manner. The preparation of tablets and the granulation thereof are possible in principle, but the resulting products are distributable even more difficultly than the starting pulverulent materials and the requirements of machinery for their preparation are considerable.

Chlorinated polymers show also some of the above drawbacks. Such chlorinated polymers are obtained in the course of the polymerisation in the form of latices, which can be economically worked up only by way of spray drying. Emulsifiers, catalysts and other additives which influence certain properties of the polymers, e.g. water-resistance, thermostability, transparency, etc., negatively, can =fefe¾¾¾#¾¾pe not be removed by a washing out operation, because in spray drying only water and very volatile substances can be removed.

Chlorinated polymers must therefore nearly almost be sold to the customer as fine powders, 'i'his is a drawback since, besides the annoying dust appearing in the further processing of the product, the defective flow capacity of the - - ί pulverulent materials causes difficulties in continuous , uniformly processing in which, for example, the resins are ½¾ supplied via1 a storage-bin and a vibrating channel to the processing riBchine, The subsequent granulation of the finished, dried pulverulent chlorinated polymers by a machine is possible and is technically performed, but it increases considerabl the costs of the resins and can therefore be utilised only in special cases.

Efforts have already been made to conduct the polymerisation of chlorinated polymers in suspension or ,-. emulsion in such a manner that the resins are obtained in a grainy or ganulated form.

DAS 1.121.333 teaches hov to obtain polymerisates or mixed polymerisates of vinylchloride from a susi>ension or an emulsion in the form of filtratable agglomerates, utilising water-soluble per-compbunds as catalysts and in particular oil-soluble fatty acids as emulsifiers, by controlling the stirring velocity.

DAS 1.076,374 points out that poly vinylchloride is obtained after polymerisation by the suspension process in the form of fine grains, if in the course of the polymerisarion a small amount of glycerine monoricinoleate is added.

It has now been found that one can succeed in a surprisingly simple manner to convert water-insoluble or slightly soluble chemicals, in particular metal salts, including meial soaps and inorganic pigments, and chlorinated - polymers, in particular polyvinyl chloride, into a form which does not give off dust, can be easily handled and is adapted The present invention relates therefore to processes for granulating chemical products which are water-insoluble or slightly soluble and which are inclined to give off dust, such m metal salts, pacticula ly metal soaps and pigments, and chlorinated polymers, e.g. poly vinylchloride, in which the above products are precipitated out of their suspension in water, in the presence of water-insoluble or slightly soluble organic compounds of a molecular weight of more than 150, preferably more than 200, and having a long chain aliphatic residue and softening point of lees than 100°C as granulating agents, whereafter, the precipitate obtained is isolated and dried.

The process according to the present invention has further application for granulating of pulverulent substances, which are water-insoluble or slightly soluble but dispersable in water. Besides for metal salts, pigments, sulf r, etc. plastics it can be utilised also for s^itl-wsE«=¾Β*ΕΦ¾Η:i>1u > such as poly vinylchloride, poly olefines, e.g. polyethylene, polyacryl compound's and mixed polymerisates thereof, ^hereby the granulation may be directly performed in the eraulsiixon obtained in accordance with the emulsion polymerisation method.

As starting materials there may also be utilised completely precipitated, washed and, eventually dried metal soaps, or dry metal soaps prepared by the melt process, anorganic water-insoluble metal salts, e.g. basic lead sulfates or pigments.

As carrier medium there is usually utilised water. However, also other suitable media ma be utilised and in some - &> The water-irisoluble or slightly soluble organic granulating agents have advantageously, a molecular weight of above 150, preferably above 200 and a softening point of more than room temperature but " ."> / below 100°C. Such granulating agents possess often a long-chain aliphatic residue. Particularly suitable are fatty alcohol esters, polyalcohols and their esters, including their partial esters, fatty acid esters, alkyd- esters, esterwaxes, fattyacid amides and fatty acid alka- nolamides, epoxydised oils, fatty acid nitriles, alkyl- phenols, anhydrides of higher fatty acids j fatty acids ketones, mixtures of mineral oils and liquid paraffins with metal soaps, and mixtures which contain mineral oils or liquid paraffins and have a melting- or softening point below 100°C. The term fatty alcohols embraces also functional derivatives thereof t e.g. fatty alcohol ethers. Es ers comprise particularly also alkylene glycol esters, including polyalkylene glycol esters, the alkylene residue being mostly ethylene, e.g. triethylene glycol esters of lower fatty acids. There may be utilised such esters which impart the end product with special properties, e.g. a stabilising plastics <; . effect for . The granulating agents are preferably solid at room temperature.

Suitable metal soaps, particularly ricinolates, octoates and/or versates may also serve as granulating agents.

These EQ&ZC X metal soaps are preferably solid at room temperature and have a softening- or melting point of 60-100°C.

However, in case that the metal soap serves at the dame time as granulating agent and as carrier medium, it may have also a higher softening point, e.g. up to about When a metal soap is utilised as granulating agent for the granulation of a metal soap, the granulating soap must naturally be different from the soap to be granulated.

When a chlorinated vinyl polymer, obtained in aqueous phase by way of the suspension or emulsion polymerisation, is to be granulated there should be utilised such granulating agents which possess a hydrocarbon residue and have a melting point above 40°C. There are particularly suitable such granulating agents which are usually utilised as lubricants in the processing of polymeric vinyl halides. They mostly contain a long-chain hydrocarbon residue. There specially suitable: whale-spermaceti or other esters of fatty alcohols or synthetic alcohols of at least 6 carbon atoms with fatty acids, or esters of fatty acids and polyvalent alcohols, including partial esters, e.g. trimethylolpropyldistearate or pentaerythritoldistearate.

Also natural fatty alcohols, synthetic alcohols, fatty acids, synthetic fatty acids, hydroxy and halogenated fatty acids are suitable. here may also be mentioned as suitable granulating agents paraffins, synthetic paraffins, montah waxes, refined montan waxes, catalytically hardened oils, e.g. hardened castor oil, esterwaxes, fatty acid amides, fatty acid alkylol amides, fatty acid alkylolamine esters , e.g. triethanolamine distearate, amines derived from fatty acids, e.g. stearylk amine CfflCj^H^,-, anhydrides of higher carboxylic acids or long-chain ethers, e.g. distearylether. The melting point of these granulating agents, i.e. when a chlorinated polymer is to be granulated, are preferabl between 40 and 150° C.

Granulating agents which are hard at room temperature do not sufficiently stand the risks during transport or and brittle and th s/e^iaisafififceieBisE&a-feSfctftefrft, may be storag softened by appropriate softening agents, Hard granulating agents are, for example, synthetic paraffins, refined montan waxes having melting points of about 100°C or ethylene-bis-stearamide having a melting point of about 135°C. Lover melting waxes, e. i carnauba waxes may also be hard and brittle at room temperature. 'I'he usual softening agents, such as mineral oils, chloroparaffins, epoxydised oils, e.g. epoxydised soybean oil, phthalate softening agents, e.g. DOP, or phosphate softening agents, e.g. tricresylphosphate , may serve for I softening.

The granulating agent may sometimes be prepared in situ. ¾is is particularly suitable for the granulation of metal soaps.

The process according to the present invention is preferably performed in such a manner that the granulating agent is added to an aqueous suspension of the substance to be granulated, ^owever, naturall it is also possible to combine the substance to be granulated being suspended in water or in an organic solvent with the granulating agent also be^Hg suspended in water or in an organic solvent.

The admixing of the solid substance to be granulated under stirring with the granulating agent being suspended in a carrier medium, as well as suspending a solid mixture of the substance to be granulated and the granulating agent in water and subsequent precipitation is also possible.

The precipitation is advantageously performed at temperatures which are above the softening- or melting point of the granulating agent* When metal salts are to be granulated the working temperature is preferably above 60°CI whereas wtm a chlorinated polymer is to be granulated said working temperature is preferably between 45 and 65°C. Vhen metal soaps are to be granulated the working temperature may sometimes, due to the formation of eutectic mixtures, be below the softening- or melting point of the granulating agent.

The suspension is, advantageously, heated to the working temperature only after the granulating agent is added to the substance to be granulated.

The granulation is mostly performed in such a manner that 2- 0 by weight of the granulation agent, calculated on the basis of the subfetance to be granulated, are added. Vhen the substance to be granulated is a metal salt the preferred amount of granulating agent utilised is 10-20 , whereas when the substance to be granulated is a chlorinated polymer said preferred amount is 7-15%.

The formation of the granulated precipitate may sometimes be facilitated by quick and sudden cooling of the heated mixture* In many cases it is advantageous to add to the granulation process an organic, water-insoluble solvent, hairing a boiling point up to 135°C or such a solvent which is volatile with steam.

The addition of such a solvent has quite a lot of advantages. Thus, the temperature at which the granulation is performed may be lowered, e.g. in cases where 60°C had been required, 40°C will now be sufficient.

The granulation time required is, on the average, by reduced to half/the addition of a solvent, e.g. an organic solve solvent as an auxiliary granulating agent.

If in the granulation method according to the invention one or more solvents are added in addition to the auxiliary granulating agent, more evenly shaped granulates are obtained, normally having a diameter of 0.1 to 1 ram. If the part of the solvent is higher, the granulates will have a diameter of 5 mm or even more. On the other hand, if it is desired to obtain granulates of smaller diameterj this can be achieved by increasing the speed of the stirring.

Moreover, when a solvent is added to the granulating process the amount of granulating agent required may be reduced. This is advantageous in such cases where the properties of the end product are unsatisfactorily influenced by a large amount of granulating agent, e.g. because it the surface of the plastic material, the 30 called sweating. If the material consists of transparent foils, it becomes then useless for many purposes.

A further advantage in adding a solvent to the granulating process consists in that one can quench with cold water after granulation, which yields somewhat firmer granulates. Wben no solvent is present there exists the danger that the granulates, when being quickly and suddenly cooled, break.

In particular advantageous is the addition of one of the solvents hereinafter mentioned for the gatanu- polymerised polyvinylchloride can be washed out to a great extent in the course of the granulation operation. The addition of a solvent is advantageous also for another reason. In most cases metal soaps must be added in any case to the polyvinyl chloride, for example, as heat stabiliser, e.g. barium/cadmium soaps, such as barium/cadmium laureate, as lubricant, e.g. calcium stearate, or to prevent discolouring zinc stearate. These metal soaps in combination with solvents, in particular with mineral oils are very suitable granulating means. *n other words the said substances which in any case are added to polyvinylchloride serve also as granulating agents.

As solvents there may, for example be utilised water-insoluble aromatic, aliphatic or chlorinated hydrocarbons, alcohols, ethers, esters or ketones having boiling points up to 135 C, preferably below 100 C, but also solvents having a higher boiling point which are volatile with steam. Suitable solvents, for example, are aliphatic benzines with boiling points of 80-100° C, methylenechloride , trichloroethylene, carbon tetrachloride, benzene, toluene , xylene, cyclohexanol, cyclohexanone and nitrobenzene.

Whe water-insoluble inorganic substances are to be granulated the rationgranul ting agent: solvent is 10.1 to 1:10, preferably 1:1. When organic substances are to be granulated, 40 times the amount of solvent, calculated on When one of the above-mentioned solvents is used, the granulation operation according to the present invention is. performed as follows.

The substance to be granulated is suspended in water, the suspension obtained is heated, with stirring, to about 30°C and the solvent and granulating agent are added. Thereafter the suspension is heated with stirring until the granulation temperature is reached. When this temperature has been reached it requires 1-5 minutes until the granulates are fully formed. .> Thereafter they are filtered, and dried. It is also possible to evaporate the main amount of the solvent, at the granulation temperature below an exhaust, with longer stirring, before the granulates are and dried.

The granulation process in accordance with the present invention has also advantages i respect of its technical per- The disbharge of formance. utnpty powdery substances from storage tanks into transport sacks is coupled with a considerable discomfort £o the workers employed for the process. This oannot entirely be avoided by providing a special filling apparatus which also means difficulties to the apparatus utilised and causes a great additional expenditure in machinery. Granulated substances, particularly metal soaps and salts, can be considerably easier separated from water and washed than pulverulent materials. The granulated contain on the average only about 50& of the water quantity of the pulverulent products of those products having the form of a filtercake. They can be more easily dried and netd not be ground. Complicated filling devices are no longer required, so that the entire manufacturing process becomes considerably cheaper. The drying is sometimes performed so quickly, easily and smoothly, that some products can be obtained by way of ordinary air-drying only in the course of 24 hours in a form ready to sell.

The products obtained by the granulation process according to the present invention possess advantageous properties. It has been proved in practice that when products, e.g. metal salts and- soaps, obtained as granulates by the process in accordance with the present invention, are utilised their effectivity is considerably increased. As it is known many of these metal salts are utilised as stabilisers. It has been surprisingly found that stabilisers in granulated form are more effective than the corresponding stabilisers in pulverized form which are dispersable with difficulty and that the granulated stabilisers require considerably less additional lubricants.

Thus, the application of, for example, a basic lead sulfate in granulated form, which has been granulated in the presence o in case that a solvent has also been present) of a distearic acid ester of pentaerythritol in the manufacture of pipes, yields a considerably more beautiful surface gloss, better mechanical values and an increase in output. The improvement of the mechanical values may eventually be traced back to that the lubricating effect of said sulfate is better than that of a basic lead sulfate, which has been granulated not in accordance with the present invention, that thus smaller quantities of lubricants are required for the dispersion of the sulfate in the plastic and thus as the utilised the mechnical properties, particularly notch mpact strength impact resistance - OU¾lmogB and cold =0¾«#ittg, are improved. It is know that basic lead sulfate and in particular basic lead phosphites are not easily dispersable in plastics when they are prepared by the conventional processes. One requires therefore relatively large quantities of dispersion agents.

Such dispersion agents are often substances which impair the mechanical properties of the plastics prepared therewith.

Many pigments, such as titanium oxide, phthaliocyanine blue, carbon black, Prussian blue and iron red oxide pigment, are not easily dispersable, so that one has to take into of account with some/them expensive coating processes in order to achieve a better dispersability. There the new process will cause a considerable improvement of the conventional technique, as by the new process a reduction of the pigment effect can be avoided.

The new process is^irn particular applicable for the preparation of such substances which are utilised as stabilised used in the manufacture of additives ¾/, rubber articles, in many other industries. ny other products may be prepared by the new process.

In accordance with the new process the following substances may be, inter alia, granulated alone or in mixture: inorganic substances, such as metal oxides, hydroxides, basic hydroxides, carbonates, basic carbonates, e.g. white lead sulfates, basic sulfates, e.g. tribasic lead sulfate, neutral or basic phosphites, basic acetates lead soaps, cadmium soaps, barium soaps, barium-cadmium soaps, calciun-, magnesium- and strontium soaps, tin soaps, alkali metal soaps and zinc soaps. These substances are usually utilised as stabiliser and fillers for halogena-ted polymers.

In particular interesting is the use of lubricants for the granulation of stabilisers for polyvinyl chloride.

The process in accordance with the present invention enables the supply to the industry of ready, free-flowing granulates comprising lubricants and stabilisers, possibly also other agents additives, e.g. antistatics., dyestuffs, etc., having an optimal composition for each processing condition. This means an important technical improvement for industry.

The process in accordance with the present invention enables in an easy manner the preparation of non-dusting, freely flowing and easily dosable vinyl halide polymers, which may, since they are filterable, easily be freed by washing from disturbing impurities, e.g. eraulsifiers, protective colloids, etc. The drying of the granulates obtained by the ne process is easily performed, as the amount of humidity of resins in the form of granulates is only about ¾ to 1/3 of that in the conventional powder form.

A considerable advantage of the process according to the present invention consists further in that as granulating agents there may be utilisedssuch substances which have in any case to be added as separating or ' lubricating agents to the chlorinated vinyl polymers.

Simultaneously stabilisers, antistatic«^¾yestuffs or other auxiliary agents may be granulated therewith, whereby the composition of the granulates may be adjusted each time to the technical requirements* This is a very important technical improvement for the plastics processing industry. In accordance with the dry-blend process, that means in mixing the various constituents in a preferably heated mixer, which is no mainly utilised, resins, softening agents, stabilisers, lubricants, agents dyestuffs, antistatics, and other auxiliary agents have to be separately weighed and mixed before they are supplied to the processing machine, '^he process in accordance with the present invention enables already in the course of the preparation of the resin to obtain the entire compound in form of a uniform freely flowing granulate* the composition of which can be within a wide range each tSme adjusted to the requirements. ¾e processing is thereby facilitated and can while non be performed continuously,/ eighing mistakes and =aa-uniformity in the end prodiet due to insufficient admixture are avoided.

The invention will now be illustrated by the following Examples without being limited by them.

Example 1 100 g of tetra basic lead sulfate were suspended in 200 cc of water, and the suspension obtained was heated with good stirring to 60°C. 15 g of triethyleneglycol stearic acid diester were then added- At about 90° C a granulate was formed in the suspension, which was filtered off and dried for a short period.

Example 2 100 g of titanium oxide were suspended in 300 cc of water and the suspension obtained was heated with good stirring to 95°C. 15 g of trimethylolpropanedioleic ester were added to the suspension at this temperature. In the course of 5 minutes the granules were formed, which were then filtered off and dried.

Example 3 100 g of zinc oxide were suspended in 200 cc of water and the suspension obtained was heated with good 0 mineral stirring to 85 C. mixture of 9 g of white/ oil and 10 g of sorbitolmonostearicdioleate was added at this jsemperature to the suspension. After about 5 minutes the granulates separated, were dried for a short period and could then be , packed.

Example 4 100 g of freshly precipitated calcium carbonate were suspended in 200 cc of water and 1 g of stearic acid diethanolamide were added to the solution obtained. After abo^t 5 minutes the granulates separated at 95°C.

Example 5 100 g of barium/cadmium laurate were suspended in 200cc of water and 15 g of pentaerithritol mono oleate were added to $he suspension obtained at 90°C. After about 5 minutes the granulate separated and was dried. 50.48 g of lauric acid and .23.99 g of OC-ethylcapronic acid were heated together with 13.72 g of cadmium oxide. Thit? mixture of fatty acids and cadmium hydroxide octahydrat soaps was added to a suspension of 32 g of barium-$-hydrate Ba(0H)^.8H20 in about 200 cc of water at 48°C, while stirring well. A precipitated was obtained which could be isolated as a dust-free granulate.

Exam-pie 7 .0 wt# of dioctylphthgjlate and 4.0 wt# of pentaerythritol distearate, calculated on the basis of the resin, were added to an aqueous suspension of fleshly polymerised polyvinyl chloride and the suspension was then heated with stirring to 60°C. The suspension was kept at this temperature for 10 minutes with stirring and was then also with stirring quickly cooled with cold water. The resins precipitated in the form of granules having an average diameter of 0.1 - 0.2 cm.

Example 8 , 100 parts of tribasic lead sulfate, 5 parts of pentaerythritol distearate, 5 parts of toluene and 200 parts of water were heated with stirring to 65°C. After about 2 minutes at this temperature a granulate is formed having an average particle size of 0.5 mm, . Stirring was terminated, the granulate was filtered off and dried.

When one workd with toluene the granulate is obtained at 65°C only after about 5 minutes of stirring. Moreovex> in this case 15 parts of pentaerythritol fiistearate are required.

The granulates prepared in accordance with Example 8 serve particularly for the therraostabilisation of pipes and cables made from polyvinylhalides.

The granulation according to Example 8 may be performed directly after the preparation of the tribasic lead sulfate. The latter is prepared by direct reaction of 4 mols of lead oxide suspended in water with 1 mol of concentrated sulfuric acid which is added slowly and continuously to the suspension at 60-90°C. Immediately there are added to the freshly prepared tribasic lead sulfate suspended in water the solvent and the granulating agent and the granulation is performed as described above. ¾us, one ¾roids the drying and isolation of the tribasic lead sulfate before granulation.

Example 9 100 parts of dibasic lead phosphite, 15 parts of pentaerithritol distearate, 3 parts of benzine, b.p. and 25o parts of water were heated with stirring to about 80°C, whereafter in about 1 minute granules having a diameter of 0.1-1 mm were obtained. These granules were filtered off and dried. They serve for the stabilisation of light-sensitive parts of polyvinyl chloride, e.g. sliding shutter sections.

When no solvent is added a granulation temperature of abo t 95°C is required* Example 10 100 parts of flowers of sulfur, 4 parts of white mineral oil, 6 parts of calcium stearate, 5 parts of carbon tetrachloride and 100 parts of water were heated with stirring O T to about 95 C. J- the course of about 2 minutes there were

Claims

Example 11 100 parts of yellow pigment dyestuff (type PV -fast-yellow H ) , 5 parts of cetyl palmitate, 150 parts of oarbon tetrachloride and 800 parts of water yield within 4 minutes, after 65 c have been reached, granules with a diameter of 0.5-2 mm. Example 2 100 parts of emulsion polyvinyl chloride K-value 70 (type: Vestolit E 70, Chem. Werke Hills AG), 100 parts of toluene, 5 parts of pentaerithritol distearate and 1 0 parts of water were stirred for 5 minutes at 80°®. Granules having a diameter of 0.5-2 mm were obtained which were filtered off and dried. In this, example anthracene oil may be used instead of toluene as solvent. C L A I M S t

1 · Process for the granulation of watur-insoluble or slightly soluble pulverulent substances, in which the above substances are precipitated out of their suspension in water in the presence of a water-insoluble or slightly soluble organic compound of a molecular weight of more than 150, preferably more than 200 and having a long chain aliphatic more than r^oora temperature but residue and softening point of /less than 100 C as granulating agent, whereafter the precipitate obtained is isolated and dried.

2. Process according to Claim 1, wherein the carrier medium is water*

3. Process according to any of the preceding Claims in which the granulation is performed at a temperature above 40°C.

4. Process according to claim 3, wherein the granulation is performed at a temperature above 60°C.

5. Process according to any of claims 1 to 4, wherein the granulating agent has a long chain hydrocarbon radical and a melting point above 40°C. r

6. Process according to any of claims 1 to 4, wherein as granulating agents there are utilised esters of fatty H corresponding synthetically produced alcohold or/8j-»*K»¾S8xalcohols with at least 6 carbon atoms and fatty acids, esters of fatty acids and polyvalent alcohols, including partial esters » natural fatty alcohols, synthetic fatty alcohols, fatty acids, synthetic fatty acids, hydroxy or halogenated fatty acids, paradtfines, synthetic paraffines, alkyd esters, ester waxes, montan waxes, refined montan waxes, catalytically hardened vegetable and animal oils, fatty acid amides, fatty acid alkylolamides e.g. stearic acid diethanolamid fatty acid alkylolamineesters/ of the formula C^^CO iCI^CI^OH^, fatty acid nitriles,/e.g. triethanolamine distearate of the formula 7 ^35^2 ' ^at^y aci^ amines, ketones derived from fatty acids e.g. stearic, anhydrides of higher fatt.y acids, alkylphenois, ethers derived from fatty alcohol e.g. dilauryl ether of the formula 2H25°C12*25 ' *&*^ alco ol polyglycolether or alkylphenolpolyglycol ether and mixtures which contain mineral oils or liquid paraffines and which have a softening point below 100°C.

7. Process according to claim 6, wherein the granulating agent is an ester of fatty acids with a polyvalent alcohol selected among the group consisting of ethyleneglycol, diethyleneglycol, triethyleneglycol, . polyethyleneg¾cols such as pentaerythritol, dipentaerythritol , trimethylolpropane and dimethylolbutanol.

8. Process according to any of claims 1 to 4, wherein the granulating agent is a metal soap.

9. Process ±HXKH according to any of Claims 1 to 4 wherein the granulating agent is a substance which is suitable as lubricant for the processing of plastic materials, in particular polyvinyl chlorides.

10. Process according to any of the, preceding claims, wherein the granulating agents is added to an aqueous suspension of the substance to be granulated.

11. Process according to any of the preceding claims, wherein the suspension is heated to the granulation temperature only after the granulating agent and the substance to be granulated have been combined.

12. Process according to any of the preceding claims, / wherein the granulating agent is utilised in an amount of 2-50 calculated on the amount cf substance to be granulated.

13. Process according to claim.12, wherein the granulating agent is utilised in an amount of 7 - 20 .

14. Process according to any of the preceding claims, presence of wherein the granulating is performed in/ water-insoluble organic solvent having boiling points up t4 135°C or su6h a solvent which is volatile with steam.

15. Process according to any of the preceding claims, wherein the substance to be granulated is a polyvinylhalide or a copolymer thereof.

16. Process according to claim 15, wherein the polyvinylhalide is an emulsion^polyvinyl chloride.

17. Process according to any of claims 1 to 14, wherein the substance to be granulated is a metal salt.

18. Process according to claim 17, wherein the metal salt is a metal soap.

19. Process accordin to any of claims 1 to 14, wherein the substance to be granulated is sulfur.

20. Process according to any of claims 1 to 14, wherein the substance to be granulated is an inorganic or organic pigment dyestuff.

21. Process for the granulation of water-insoluble or slightly soluble pulverulent substances, substantially as hereinbefore described with reference to the Examples.

22. Granulated substances whenever obtained by the process according to any of the preceding claims. AGENT FOR APPLICANTS Tel-Aviv, this 3rd day of October, 1966