DE2205126A1 - Alkali metal aluminosilicates, processes for their production and masses from them - Google Patents

Description

Alkali metal aluminosilicates, processes for their production and masses from them

The present application is an additional application to the Registration P 19 25 868.5. ·

The present invention relates to the manufacture of finely divided Substances that can be used in a variety of ways, e.g. B. as pigments, capacity conditioning agents U3w., But which are particularly useful as rubber reinforcements and in papermaking. the Pigments according to the invention are made by reacting a water-soluble alkali metal silicate with water-soluble ones Aluminum salts of strong acids, preferably by reacting sodium silicates with aluminum sulfate according to methods, those by the methods described in U.S. Patent 2,759,073 are generally related. The products that are made with the process of this patent specification as well as with the similar inventive method result, if

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they are in the sodium form, sometimes as sodium silicoaluminates, Sodium aluminosilicates, synthetic zeolites, Mineral pigments and the like. Described.

Although the products of the process according to the invention in general are substantially the same in chemical content as those in the aforementioned patent • described, they differ markedly from those in their physical characteristics and in their surface chemistry. In particular, it is concluded that they relate to differentiate between their particle size, the chemical nature of the particle surfaces and the type of aggregate state, which features as features of primary interest in the rubber reinforced class of synthetic Silicas and silicates are considered. Although the products available according to the aforementioned patent good for rubber compounding and papermaking can be used, the distinctly different products according to the invention have proven to be very superior, at least as far as it has been proven in practice up to now. More precisely, the new. Products are the present Invention at least comparable in terms of usability with the currently best known rubber fillers and have another valuable, improved usability in papermaking. Therefore the new products described here can be used against those described in the patent mentioned on the basis of criteria The suitability for rubber alone can be easily demarcated, and perhaps the distinction is made on such a basis better, because there are at least certain very technical, physical properties that can be used to delimit them are speculative to a certain extent. In addition, the present method is markedly different.

In addition to the advantage of their improved properties, the new products also have the advantage that they

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much more economical than previously known, similar substances can be produced.

As for the economic benefits, "so will these with reference to the type of product resulting from the process described in US Pat. No. 2,848,346 " This US patent described products are recognized masses as very suitable for the compounding of Rubber. In fact, these latter patented products have optimal properties according to current standards. As can be seen from this patent specification 2.u, products known as hydrated silica (pigments are hydrated), and hydrated ones Silicas are produced using a different method, namely by reacting dilute sodium silicates with dilute sulfuric acid. Although the products of this latter patent are currently more suitable than those of the aforementioned patent specification 2,739,073 was Particularly when it comes to the compounding of rubber, various factors play a role in its manufacture Related, including raw material costs higher product costs. The present invention provides end products that are more valuable in terms of Properties are at least equivalent to the products of the latter patent, while according to the general and less expensive processes of the former patent are available. '. ·

A further improvement of the process according to the invention results in connection with the economy of the Sodium sulfate extraction, which is a by-product of the salt Reaction is. More specifically, the method of the invention comprises the deliberate addition of sodium sulfate as part of it of the reaction medium, as a result of which the sulphate wash liquor has a much higher concentration of sodium sulphate, d. H. the amount added plus the normal amount during the course

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the amount formed by the reaction. Since the amount of liter, which is used to wash the sodium sulfate reaction products free is the same, regardless of whether sodium sulfate is added or not, it turns out that the wash liquor has a much higher concentration of this salt and therefore can be processed more economically. However, as will be seen, the addition of sodium sulfate has other meanings than this benefit.

Another advantage of the invention that comes directly from the implementation the substance arises from the beginning of the reaction in the presence of sodium sulphate, that is that the product obtained is everywhere is more uniform in a particular batch. It seems that sodium sulfate has a pronounced effect on the type and The size of the aggregate exerts the tendency towards the formation of smaller aggregates and the surface area increases and the oil absorption properties improve. It is believed that this benefit is basically taken the more uniform chemical reaction conditions of the inventive method in contrast to the known State-of-the-art processes are attributable. The previously known basic reaction led to the formation of Sodium sulfate. To the extent that the reaction takes a while continues, starting from the amount zero, sodium sulphate is formed, by the end of the reaction the total amount has arisen. As can be understood, therefore, is the reaction environment at the beginning a completely different one compared to the environment as it exists after a few minutes and the reaction environment changes constantly until the reaction is complete. By providing a substantial amount of sodium sulfate from the beginning the effects of this salt are also present from the beginning, so that there is no period of time in which the effects are completely absent and there is no period of time in which there is less than the optimal amount of salt. The optimal amount, as well as minimum useful amounts, contribute to this invention.

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Prior to the present invention, it was not thought that the reaction of sodium silicates with aluminum sulfate could be carried out in such a way as to effect a really marked change or changes in the nature of the end products, at least as regards those features which are important in the art of rubber reinforcement. Thus, the subject of the present invention, which clearly proves the opposite, is a very instructive finding in the art of producing silica-like pigments. As more _v and more comes to light, the chemistry and the chemical nature are the surface of the synthetic silicas and silicates very complex indeed, and it seems that there is still a considerable additional insight can be gained into it has before it cleared up as almost completely and calculated. In the present case, as is assumed, it is very likely that the products obtained differ technically in their structure quite a bit from the previously known chemical substances; however, proof of such a fact, followed by the provision of a precisely distinguishing definition, is at least very difficult to provide with the facilities available today.

As stated above, the products according to the invention are similar to the procedures previously described in US Pat. No. 2,739,073 manufactured products. In general, these products are masses consisting essentially of alkali metal, Aluminum and silicon oxides exist and in extremely small particle sizes as very fine precipitates have been obtained in that dilute, aqueous solutions of an alkali metal silicate and a water-soluble aluminum salt, such as aluminum sulfate, aluminum chloride, aluminum nitrate or ammonium alum, mixed in a suitable manner at very low concentrations and reacted with one another will. The pigment particles precipitated are essentially

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all less than 1 micron in diameter and on average less than 1/2 micron in diameter. In the main the particles range from about 0.02 to 0.5 microns. In addition, they are characterized by their extraordinary brightness and characterized by other properties described below that make them exceptionally valuable for purposes of use do as shown above.

One of the most significant aspects of the present invention includes the finding that the basic reaction is selective on the production of special forms of sodium silicon - aluminates can be steered. Under special forms understood that the present invention enables the final product according to the most desirable shape for the Tailor use in a specific environment. So found when a reinforcing material for the Vex ^ turn of the highest quality is desired in rubber shoe soles, heels and the like, certain overall conditions that the Providing an optimal set of performance metrics. The present invention provides such products with much improved texture ready. It is also known that the rubber industry not only needs reinforcing materials with very specific performance indicators, but also that also the economic aspects of the process producing the end rubber are not due to the added substances may be adversely affected. For example, it can happen that a pigment with the desired, very fine Performance indicators can be produced, but the total curing time in the rubber production process, which making such a pigment necessary is longer than a similar pigment, which is somewhat less acceptable performance metrics having. To a certain extent, this has led to a compromise in the properties of the rubber product in view of the important, economical time factor in the manufacturing process. The total curing time is also used in other rubber applications, such as the

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Tire manufacturing, of "importance. Accordingly, it is very important that one "when considering the technique of rubber reinforcement has all the requirements in mind.

That aspect of the present invention that is more specific has to do with rubber reinforcement in the tire field includes various features similar to those which are needed in the shoe sector; however, certain performance metrics are required of tires that are substantial differ. In other words, the most desirable tire pigment is not necessarily equally suitable in shoe technology. The present invention provides reinforcing fabrics ready for help tailored to meet specific needs and those in operation are superior. .

Vo the pigments are used as fillers in papermaking are to be, certain somewhat different characteristics are still desirable. Although any of the Pigments prepared according to the invention have an advantage over Previously used fillers that can be used as paper filler are those that are controlled under certain Conditions that have been established are more particularly desirable because of the greater improvement in their strike-through performance. This is particularly important with low quality paper stocks such as newsprint.

Furthermore, the pigments produced according to the invention can also be used in fine paper as paper fillers with certain advantages over previous fillers; some of them give the fine paper a lightness and an opacity at least 0.7 points higher than the lightness values and at least 0.5 points higher than the opacity values given by the sodium aluminosilicate produced according to the processes, the 739,073 are generally described in U.S. Patent No. Z.

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466 *

As indicated above, it can be assumed that it "has not yet been made it was possible to control the basic reaction in a consistent manner in such a way that these relatively subtle modifications of the end products that can correspond to improvements for certain uses.

Although the method of the invention has a number of conditions which are modified according to special needs, it was found that a predetermined one minimal amount of sodium sulfate as part of reaction medium must be present from the start of the reaction; otherwise the physical and surface chemical properties of the end product will fail To impart characteristics which fall within the range of pigments, which are here regarded as being improved in kind be, d. H. to improve them in at least one property. (At this point the remark may be appropriate be that when the general reaction type is carried out with another aluminum salt, e.g. aluminum chloride -will, the corresponding acid salt is required; d. H. along with aluminum chloride, sodium chloride should be in the Reaction may be used.) Continuing the above, it should be noted that, although the sodium sulfate from the beginning the reaction must be present in a minimum amount, it is present in a fairly large amount without harmful effects can, at least in so far as it goes to the objects of the present invention. The present invention teaches a range of sodium sulfate conditions that will produce rewarding results. If sodium sulphate is used in unnecessarily large quantities is present, sets in, as is common, a reverse reaction, and the advantages otherwise achieved according to the invention are easy lost. The exact point at which this occurs is extremely difficult to pinpoint; as far as this point is quantitatively determined in the present invention, it is to be understood that it is related to the performance characteristics which are currently required in the various areas of use, and it is not to be

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conclude that another amount to produce improved Products that comply with a modified standard. Because these required performance metrics can change in the future, it is to be expected that a greater or even a lesser amount of sodium sulfate can be allowed. It should therefore be emphasized that the knowledge of the advantageous sensitivity to the basic reaction the sodium ul fat content in relation to a community of products is an extremely important, if not the most important, aspect of the present invention. When the sodium sulfate conditions according to the teaching given here are observed when carrying out the reaction, the result is a product that improves in at least one important relationship common to the needs of the rubber industry as a whole is, and this pigment has both general usability of the previously known kind and improved usability in papermaking on; In addition, there are economic advantages in the production of sodium sulfate.

There are several aspects of the procedure within the above described, broad inventive concept, the control of which for the purpose of creating even more improved features of the End products related to special needs is desirable. For example, to make a pigment, which is more suitable for the shoe industry because of its properties, it is generally more advantageous to implement to be carried out in such a way that a dilute aluminum sulfate stream of a previously prepared, highly diluted sodium silicate-sodium sulfate solution is fed. Thus, the totality of sodium silicate and sodium sulfate are related to the aluminum sulfate in terms of quantity as desirable is calculated, a reaction medium to which the aluminum sulfate is supplied over a given period of time. As. will be described more fully below provides The rate of aluminum sulfate feed is another method of controlling the nature of the end product. Furthermore,

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with regard to products with special utility in the shoe industry, say that such products can be obtained by slightly modifying the reaction method from that just described. In particular, it has been found that, with a view to obtaining such improved products which vary only slightly in nature, the reaction can be carried out by preparing a sodium silicate-sodium sulfate reaction medium which consists of only about 50 % of the total amount of such substances, which is calculated as necessary in the reaction with respect to the aluminum sulfate, with the remaining sodium silicate-sodium sulfate solution being fed to the reaction mass as one stream (or streams) concurrently with a particular aluminum sulfate stream. Here, in turn, a certain variation in the speed of the aluminum sulphate feed and other modifications of the process are possible within limits without the desirable properties of the end product being destroyed. For example, by adding a stream of water-soluble aluminum salt, especially aluminum sulfate, to the reaction medium for a period of time which exceeds by at least 10 seconds or more the usual period of time which is generally used in the normal procedure for adding aluminum sulfate to the reaction mixture before the addition of the other reactant, sodium silicate as described in US Pat. No. 2,739,073 and parent application P 19 25 868.5, the resulting product consequently gives fine paper improved sheet brightness and hiding power. A modification of the conditions just described, ie the way in which the reactants are mixed, leads to the production of slightly different products; however, all products are improved in one respect or another over products previously known for use in the same environment.

If you look at the process from a different point of view, namely from the point of view of the production of end products

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Products which have properties which are considered "particularly desirable" in the paper industry and in the tire sector, the reaction is preferably carried out in a slightly different manner, since the desired differences in the products are pronounced and can be detected in use. In this connection and in contrast to the above method, it is desirable that the larger proportions of the reactants are fed simultaneously as separate streams to a highly diluted sodium silicate-sodium sulfate reaction medium. More specifically, a relatively smaller proportion of the previously calculated amounts of sodium silicate and sodium sulfate (usually fed in as a combined individual stream here) is used as the reaction medium, with the remainder of such previously calculated amount representing the sodium silicate-sodium sulfate feed stream which is simultaneous with a Aluminum sulfate stream is fed. The properties created by this method seem to be found to be increasing in proportion to the insignificance of the amount of sodium silicate-sodium sulfate in the solution which provides the reaction medium. The critical point has to be seen in connection with the minimum amount of sodium sulphate, the presence of which is desired as part of the reaction medium at the beginning. Depending on the concentration of sodium sulfate in the precalculated feed stream, the exact amount dispensed to form the reaction medium will vary. However, for example, to carry out the reaction within the preferred conditions, about 10 % of the total amount of silicate and sodium sulfate are used to form the reaction medium to which the remainder of the reactants are delivered over a period of time; and about 50 % of the previously calculated total amount of sodium silicate sodium sulfate can be added to form the reaction medium while still obtaining a product with improved properties for the particular use.

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It can thus be observed that the characteristics of the reaction medium with regard to the amount of sodium silicate-sodium sulfate contained therein in relation to the rest of the reactances to be supplied, an important variable in the tailoring of special End products are.

As a general rule, it can be stated that once the amount is used to produce a given amount sodium sulphate has been determined on end products, the presence of a greater or lesser total amount of sodium sulphate in the initial reaction batch as found regardless of the nature of the particular one desired End products is not very critical; however, the minimum amount of sodium sulfate is always provided at the beginning of the reaction. So it is not necessarily necessary that the sodium sulfate sodium silicate to provide the reaction medium is admixed and supplied as a single stream. Instead, the sodium sulfate batch can be used as a separate stream • are fed; or all or any part of the total amount thereof can be used prior to the addition of the reactants chemical substances are added to the water mass, moreover, if. desired, the sodium sulfate to be fed to the reaction medium with the aluminum sulfate after a The minimum amount of sodium sulfate has previously been fed to the reaction zone.

Another distinct aspect of the process relates to the pH of the final pigment products finally obtained. In In this context, it should be noted that pigments obtained by performing the method in the range described above have been produced by operating methods and have improved properties compared to the previously known pigments, have a pH of about 7 Ms 11. Besides that it was found as a further aspect of the invention that within this range the pH of the pigment is more defined Relationship to the suitability of the pigments for use in

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the various different environments mentioned above in general were discussed, stands. In particular, it has been found that when pigments are made, their pH is in the range from about 7 »2 to 8.5 and especially and preferably is in the range of about 7 * 5 to 8, such pigments are certain Have features or properties that make them more useful in paper and in the manufacture of rubber tires ... Pigments with a pH in the range from about 7 to 8 have been found to have certain characteristics or properties, their improved suitability in the shoe industry in the manufacture of soles, heels and the like. to lend. If, therefore, the aim of providing the inventive, tailored to the intended use Looking at products, controlling the pH of the final product is one aspect of the invention.

The pH control includes the special adjustment to the initial reaction, which leads to the precipitation of the pigment. • Basically, the reaction is carried out in such a way that the final pigment slurry resulting from the reaction falls within certain levels according to the desired final pH "of the pigment. In the case of products that are in paper and also are particularly useful in reinforcing tire rubber, the reaction is controlled such that the pH of the final slurry falls between about 5.5 and 9 »5 and more preferably between about 5» 8 and 7> 0. In the event the manufacture of a Pigpaentes with special applicability in the shoe industry may drop the pH of the final slurry in the same area, ie zwischeny about 5 »5 and 9 _t 5 are, in particular, and however, preferably the pH is of Endauf slurry so regulated that it is about 5 * 8 to 6.0 As will be understood by those skilled in the art, the pH of the final slurry is directly related to the sulfate ion content of the slurry and it easily passes through Adjustment of the aluminum sulfate amount, which is fed to the reaction mixture, controlled.

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As it is desirable that the pH of the final slurry is on the acidic side, so slightly more aluminum sulfate than is required for the reaction with the sodium silicate provided. Similarly, if a lower pH in the slurry is desired, a slightly higher amount of aluminum sulfate is provided. β it should be noted that the pigments with higher pH advertising, such as has been shown to provide slightly shorter scorch times in the rubber compounding process. On the other hand, the stiffness quality of the rubber end product begins with the increase in the pH of the pigment to decrease slightly to a higher amount.

As can be seen from the above, the desired pH level of the pigment product can be regulated or adjusted very easily by adjusting the reaction medium to the acidic side with a slight excess of aluminum sulfate. It is now desirable to discuss the pH issue from a different point of view which is also related to the nature of the end products. This additional consideration has to do with the pH of the reaction medium over the period of time that the precipitation reaction is taking place. This period of time can be varied widely; however, in general, the reactions take about 20 to about 40 minutes to complete, excluding the aging time prior to filtering the slurry. Thus, in discussing the precipitation pH, it will be understood that it will be related to conditions which will occur during such periods of time, as well as at other times which may be selected for the precipitation reaction to occur. As indicated previously, it has been found that the precipitation pH level has a marked effect on the nature of the particles which make up the final pigment products. In the case of paper and tire pigments, it has been found desirable to keep the precipitation pH between about 10.4 and 10.9 . keep.

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In the case of special products for use in the The footwear industry has found it desirable to have a slightly higher pH, i.e. H. from about 10.9 "to about 11.3, preferably at 11.2. It It should be noted that exact pH values in a given reaction mixture are difficult to observe and use Safety are to be maintained because the permissible deviation yon preferred precipitation pH-Verten within the error limits of the pH measuring instruments. Therefore, in the process of the present invention, the reaction conditions become based on previously determined feed rates of the aluminum sulfate feed. As can be understood, the higher the rate of aluminum sulfate feed, the lower the precipitation pH is, and vice versa. Of course, the alum feed rate has if all or more of the sodium silicate is present in the reaction medium from the beginning of the reaction until this amount is consumed in the reaction has very little effect on pH.

Perhaps it is impossible to make a definitive statement as to the physical or chemical alteration to offer that in the precipitated particles as a result of controlling the pH during the precipitation reaction or, since the pH of the finally obtained pigment particles is different, is caused. So far however, as observations presumably permit such a determination, it appears that the indicated precipitation pH values, especially the preferred levels, for producing more uniform pigment particles, what their size distribution concerns, which uniformity is the result of a reduction in the number of coarser particles seems to be in the crowd. With the lowering of the precipitation pH Obviously there will be a larger number of relatively large, agglomerated pigment particles educated. If the precipitation pH is higher, i.e. H. within

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The preferred area here are the agglomerate structures smaller; Moreover, such pigments have been found to have a larger surface area and the agglomerate is less tight.

As regards the pH of the pigment particle, it was found that that pigments with a higher pH value tend to attach a relatively high degree to rubber products To give rigidity; and, while the opposite is true for lower pH pigments, tensile strength becomes of the rubber product improved. These phenomena are probably related to surface chemistry Characteristics of the particles, believed to be related to reactions that occur between the rubber and such pigment surfaces. A further discussion of this point would presumably be complete, at least at this point in time theoretically. The end result achieved by pigments of the features described here is worth noting to be considered when the matter is examined from the point of view of improved usability; the explanation, what this is about is in any case unnecessary.

As is well known, the general reaction which includes sodium silicate and aluminum sulfate can spread to one another Temperature range can be carried out. The presence of the minimum amount of sodium sulfate throughout Reaction according to the present invention does not require any special changes in specified temperature conditions. According to the invention, the improved features of Pigments, which show their increased usefulness in rubber compounding processes, in which the scorching time is markedly shortened, if the previously described Reaction is carried out at a temperature in the range of about 21.1 to about 82.2 ° C or above, although no particular advantage in the use of higher reaction

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Temperatures. Taking into account anything that makes the reaction more practical, a more suitable temperature range is from about 46.1 to about 73 * 9 ° C process is carried out, is set by the initially set volume and temperature of the reaction medium, and whether the reaction medium comprises the whole of sodium silicate-sodium sulfate solution or only a portion thereof in such a manner to that gives a reaction temperature, the ^'v in your region from from about 5117 "to about 65.6 °, and preferably from about 54.4 to about 60.0 ° C. In all cases, however, it has been found advantageous to run the aluminum sulfate flow of the reaction at a temperature as high as this range and preferably at a temperature of at least 54.4 to about 71 ° C. above the desired target. The importance of controlling the aluminum sulfate temp erature is believed to be related to changes that occur in the surface chemistry of the particles of the pigment being produced. More precisely, certain properties of the pigments according to the invention presumably arise as a result of the coordination of aluminum with silica, the precipitation of the pigment during the reaction being achieved via aluminum sulfate. It is believed that such precipitation and coordination depend significantly on the uniform availability of aluminum ions in an acidic medium. Such availability itself is related to bits of dissociation and the acidity of the aluminum sulfate, which are temperature dependent. It may therefore be that the recommended temperature control of the aluminum sulfate feed stream results in the production of pigments with greater uniformity of surface chemical characteristics, the reaction environment being such that particularly uniform precipitation and surface coordination conditions are created. It can be seen that such observations

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genes can be fully descriptive of circumstances - but need not be - at least not to the fullest Scope because a variety of other reaction conditions and ratios are possible. Moreover, must the material related to surface chemistry at this stage of technical knowledge as at least somewhat speculative, and especially so when the final properties of the here manufactured Products can be ascribed to such phenomena.

If the goal is to produce pigments used in the shoe industry, such as in rubber soles, heels, etc., are to be used, it has been found to be more convenient and advantageous to use aluminum sulfate in a Temperature that is closer to the upper limit of this temperature range, in particular about 7ij1 ° C. The lower limit of the temperature range, i.e. H. about 54.4 to about 60.0 C is found to be at the time of manufacture of tire pigments and paper fillers. As for the temperature of the sodium silicate feed, so this is not critical, and the sodium sulfate can at room temperature up to the desired reaction temperature are fed.

In practicing the invention, a sodium silicate-sodium sulfate solution is used produced which the silicate in the range of about 60 to 360 kg / m ^ ("O.5O to 3.P lbs / gal "), and sodium sulfate is here in one Amount of 1 to 10% by weight, based on such a silicate solution, added. In general, it has proven advantageous to increase the sodium sulphate content to the extent that how the sodium silicate solution is more dilute. So if a relatively dilute sodium silicate solution is made sodium sulfate is added in larger quantities, d. H. in an amount equal to the upper part of the 1 to 10% range is approaching. Conversely, more concentrated SiI

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kat solutions combined with a lower amount of sodium sulfate. If the process as it is currently preferred in the manufacture of soap and newsprint pigments by supplying separate streams of the sodium silicate-sodium sulfate solution and the aluminum sulfate solution so prepared is carried out, are particularly suitable concentrations for sodium silicate, as has been found in the range of about 168 to 192 kg / m * and usually about 180 kg / m ^. For this particular sodium silicate concentration the amount of sodium sulfate supplied is about 5% by weight of the

Sodium silicate solution. Such a current becomes a heating chamber supplied that contains 1 volume of fresh water, one such. Volume about 3 »33 to about 10.00 1 Water per kg of silicate (0.4 to 1.2 gallons of water / Tb, of silicates) and preferably about 5 »° 0 to 8.33. if the aim is to produce pigments which are particularly useful in the shoe industry, in which case preferably the aluminum sulfate directly to the total amount of the

Sodium silicate sodium sulfate is supplied, which is provided as a further diluted reaction medium, is the Concentration of the sodium silicate solution produced is preferably in the range from about 72 to 96 kg / m ^ and is usually about 83.9 kg / m. Sodium sulfate is used in this case on the basis of about 3% by weight of the silicate solution.

In the previous part of the description it was stated that the method of carrying out the precipitation reaction, paying particular attention to the mixing of the total quantities the reactants can be approached in a variety of ways. In particular and in a somewhat summary manner, it was stated that that a reaction medium can be made up of very small amounts of each of the sodium silicate components and sodium sulphate up to the calculated total amount of these substances and then various reaction media

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Aluminum sulfate supplied as a practically constant current with mixing taking place with thorough agitation. As can be seen, the total amount of Reactants and the sodium sulfate are mixed very rapidly or very slowly and in either case the precipitation reaction occurs in front of you. If z. B. the goal of bringing the reactants together is merely the yeast position of one

Sodium aluminosilicate in the presence of the minimum amount of sodium sulfate according to the teaching given here ', whereby a product is to be obtained j without any performance features special attention is paid to highly specialized applications, or if special applications are ignored the speed at which the reactants are mixed, so it is to be understood that such speeds are required can be disregarded. In general, however, it proves to be in accordance with the present invention or otherwise not considered beneficial, the mixing speed en completely disregarded, because the uniformity of the particulate mass from which the Compound end products, deteriorates or the economics is adversely affected. According to the present invention, it turns out to be undesirable is, in any event, to attempt to effect the reaction in a period shorter than about 5 minutes the actual sodium silicate-sodium sulfate reaction medium that has been employed; d. h. "the amount of calculated amount of such substances, which are provided as a diluted medium. It should also be mentioned that little or no benefit is gained from unduly prolonging the reaction, and in no case therefore does it prove essential to mix the reactants for a period of about To extend beyond 75 minutes. Such periods represent the loading time for aluminum sulfate and also for the Sodium silicate-sodium sulfate solution in those cases in which their total amounts are not considered to be the reaction medium

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are provided to accommodate the aluminum sulfate. Therefore, in practice the mixing of the reactants within these extremes, d. H. between about 3 and 75 minutes, - occur. Usually, however, it does not prove particularly expedient to meet each of the two Extreme approaching too closely, although depending on the objective of the procedure, i. H. depending on which product with particular high performance characteristics for special applications, as mentioned here, are sought, one finds that the mixing times are expediently longer or shorter are. A more suitable range for the production of pigments of general use from the point of view the particle uniformity in such properties as particle size, oil absorption and surface area ranges from about 10 to 50 minutes. Especially if the calculated Total amount or a larger part of the ITodium silicate and amount of sodium sulfate is provided as the reaction medium (this is the preferred method of preparation of substances with higher usability in shoe soles and the like), the aluminum sulfate is preferably somewhat more rapidly, for example within a period of time not longer than is added about 25 minutes, and preferably within about 18 to 20 minutes; Sodium silicate and sodium sulfate are also added to the reaction within such periods of time when the total amount of such substances is in reaction medium is not already present. If the goal is to continue manufacturing, fabrics that are suitable for Longer mixing times prove to be more suitable for use in, for example, the tire and paper industry than more desirable. Especially in the pail of the production of soap pigments, preferably providing an reaction medium that is less than 50% of the total calculated amount on sodium silicate and sodium sulfate, for example 10%, it proves beneficial that the total amount of the aluminum sulfate and the remaining amount of sodium silicate-sodium sulfate solution in the reaction medium

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may be mixed by supplying separate streams thereto over a period of no less than about 25 minutes, preferably within 35 to ½ minutes. Within these indicated ranges, as will be understood, fairly precise interrelationships with other factors influencing the pH of the various reaction media must necessarily be observed in order for the precipitation reaction to take place in accordance with the more desirable pH conditions indicated above.

So far in the present description reference has been made to sodium silicate and sodium sulfate concentrations such as also to the desirable degree of dilution provided by the actual reaction medium. It's understandable, that taking into account that a high dilution for the production of the desired type of final product is desirable (especially the overall uniformity of the particle character), the dilution of the Reactants can be achieved in practice by using a very dilute stream fed to a reaction medium containing an appropriate amount of relatively concentrated sodium sulphate solution. It can also be said that an unnecessary dilution is merely leads to the problem of water removal and also otherwise affects the economics of the process. Consequently It goes without saying in the following specification of the concentration of the aluminum sulfate that this is in the ratio represents the total amount of water as generally taught and as indicated below to be appropriate is considered to be introduced into the procedure, the other conditions being billed will. Considering concentrations that are relative to the other appropriate conditions discussed here, through which the various products are available, useful, it has accordingly been shown that the Concentration of the aluminum fulfate stream considerably

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but preferably in practice not less than about 12 and not more than about 420 kg / m * have been considered suitable, aluminum sulfate concentrations of from about 144 to about 192 and especially from about 168 "kg / m ^ are particularly useful. On the other hand, a more suitable concentration with respect to other suitable conditions for tire reinforcement, paper and the like is between about 264 and 336 kg / m ^, especially around 300 kg / m ⁵ .

In all cases it is. Amount of the precipitation reaction actually supplied aluminum sulfate so large that a final slurry is provided, the pH level of which with the pH of the desired end product matches.

No special equipment is required with the procedures described here. The reaction vessel itself should come with Heating devices, e.g. B. a steam jacket equipped be to maintain the desired reaction temperature; also there should be an adequate device to Move have to have a strong backflow to the body of liquid exercise and thereby avoid zones of high concentration of the reactants to be added, desirable is to bring the reactants together in such a way that an instantaneous reaction of all material fed to the fullest extent reasonably possible, as this is the unity of the resulting Product promotes. Storage vessels equipped with heating devices are provided for the reactants, which are connected to the reaction vessel via lines to which flow control devices are connected. The reaction vessel is provided with an output line which leads to a filter that is released from the rotating thread

- 23 209836/1058

solution type ("rotary-string release type") and on which the precipitate is washed with water to remove sodium sulfate as a liquid, this liquid being sent to storage. A portion of this sulphate liquid is used in the subsequent production as a source for the minimum amount of sodium sulphate which is required according to the invention. Since the filter cake is thixotropic it needs to be liquefied and for this purpose a tank equipped with a suitable agitator is needed. The mass is dried in a conventional spray drying system.

The example immediately below illustrates in detail the working method and conditions that are expedient can be followed in practicing the invention.

example 1

The reaction vessel is charged with 378 liters (10 gals) of water and a sodium silicate (NapO2.5 SiOp) -sodium sulfate solution with a silicate concentration of 192 kg / m * and a sodium sulfate concentration of 5% by weight of the silicate a rate of 0.742 1 (0.196 gpm; gallons per minute) $ e minute for 1 minute was added. The temperature of the resulting reaction solution is adjusted to 71 »1 ° C. and held there. "Alum" is added to the reaction volume in a concentration of 312 kg / m * at a temperature of 71.1 ° C. after the stirrer has first been started at a rate of 0.24-9 l / min at the same time the remaining, calculated amount of the sodium silicate-sodium sulfate solution is fed in at its rate of 0.742 l / min. This solution is fed in over a period of 38 minutes, and then the feed is interrupted. Maintain long until the pH of the reaction mass is down

- 24 209836/1058

Has lowered to 5 »9. A settling or choking period of 15 minutes is observed and the pH is measured again and readjusted to the value 5j9; The mass is then fed to the filter, where it is washed with water to obtain sodium sulfate and to reduce its residual content to about 3 %. The cake obtained, which is solid (thixotropic), is fed to a stirrer and liquefied, whereupon it is spray-dried to a moisture content of 5% at a pigment temperature at the outlet of about 104.4 ° C. dry pigment has a pH of 8.5 and the mass is composed of extremely fine particles, relatively few of which are larger than 0.5 microns.

209836/1088

Example no.

Volume of water of reaction; Liter speed of supply of silicate, including from NagSO ^; Liters / minute Initial supply duration of silicate sulfate; Minutes Duration of silicate sulfate addition; Minutes silicate concentration; kg / m * Salt concentration in silicate alum concentration; kg / mr

J ₀ concentration of the silicate in the reactor before the ο alum feed begins; kg / cm5

Alum speed; l / minute reaction temperature; ⁰ C alum feed temperature; ⁰ C '. · ■ final slurry; pH _: - ripening temperature, ripening time
pH value of the pigment

Aa rubber measured results; shoe soles

Initial viscosity Minimum viscosity Maximum viscosity Scorch time

8 minute Olsen stiffness, 8 minute NBS abrasion

578 578 578 578 Ψ 0.742 0.742 0.742 0.742 § 1 7.8 19.5 51.2 58 51.2 19.5 7.8 192 192 192 192 5% 5% 5 % 5 % 512 512 512 512 5.60 24.0. 52.8 75.1 0.249 0.2877 5.860 6.02 71.1 71.1 71.1 71.1 54.4 54.4 54.4 54.4 5.9 5.9 5.9 5.9 71.1 71.1 71.1 71.1 15th 15th 15th 15th 8.5 8.45 8.4 8, P 20.8 25.0 25.7 29.5 18.4 19.9 22.4 24.7 46.8 47.9 49.9 50.8 ro
NJ 2.04 2.54 2.50 5.16 ο 56.1 41.0 41.5 45.2 cn 77 78 70 66 ro
CD

Results measured on newspaper

ΪΑΡΡΙ brightness at 5% RECOVERY Q ^ PI-opacity at 5% filling Druckfarbenaufnähme at 5% ig ^he filling percentage reduction of the punch at 5% ige.r filling Percentage Retention at 5% filling

64.9 64.6 64.4 63.9 Ψ 88.6 87.8 86.8 86.5 2.8 3.0 3.7 • 3.9 cn 73.8 72.0 65.4 63.6 59.5 59.0 • 57.3 53.1

ro ο co oo

rs). cn

oo co

Example no.

Volume of water of reaction; Liter rate of supply of silicate, including ITa ₂ SO ^; Liters / minute

Initial supply duration of silicate sulfate; Minutes duration of the silicate sulphate addition; .Minutes of silicate concentration; kg / m ^ salt concentration in silicate alum concentration if kg / m * concentration of the silicate in the reactor before the alum supply begins; kg / m * alum speed; l / minute reaction temperature; ⁰ C alum feed temperature; ⁰ C final slurry; pH ripening temperature ripening time pH value of the pigment

Results measured on rubber; Shoe soles

Initial viscosity Minimum viscosity Maximum viscosity scorch time

8 minute Olsen stiffness 8 Mp. Slot KBS abrasion

378 18.9 6814 6814 0.742 0.946 116.7 133.8 59.0 4th 39.0 4th 0 35 0 35 192 240 212.3 180 5 % 0.0 3.0 7.0 312 300 168 300 82.7 39.6 85.2 13.2 0.946 0.450 73.3 58.9 71.1 37.8 60.0 57.2 54.4 37.8 71.1 54.4 5.9 9.0 5.9 6.9 ' 71.1 37.8 62.8 57.2 15th 15th 15th . 15th 8.5 - 7.3 7.9 34.8 27.0. 27.1 28.5 24.0 24.0 - 54.6 52.7 53.7 - 5.41 2.92 2.25 - 49.9 36.8 46.3 - 54 60 67

vn cn cn

ro ο cn

<o co ω

Results measured on newsprint (TAEPI brightness with 5% filling TAFFI opacity with 5% filling Printing ink absorption with 5% filling percentage reduction of the penetration with 5% filling

Percentage retention with 5% iS6 ^ filling

63.9 65.2 Ψ 63.7 88.4 88.8 ι 86.5 6.1 2.1 cn 3.9 47.0 - 73.9 cn 63.6 - 53.1

ISJ fO O

Example no.

Volume of reaction water; Liter rate of supply of silicate, including Ha ₀ SO /,; Liters / minute 10

Initial supply duration of silicate sulfate; Minutes duration of the silicate sulphate addition; Minutes silicate concentration; kg / nr salt concentration in silicate alum concentration; kg / nr concentration of the silicate in the reactor before the alum feed begins; kg / m3 alum speed; l / minute reaction temperature; ° ⁿ

Alum feed temperature; Final slurry; pH Soaking temperature Time of maturation pH value of the pigment

Results measured on rubber: shoe soles

Initial viscosity Minimum viscosity Maximum viscosity scorch time

8 minute Olsen stiffness, 8 minute NBS abrasion

5515 (10% SO ₄ ) 3480 120.5 120.5 4th 35 240 240 7 % 7 % 300 300 28.8 ■ 28.8 68.0 68.0 60.0 60.0 60.0 60.0 9.0 6.0 60.0 60.0 15th 10.2 8.1 19.5 - 16.3 - ^ 3.2 - ■ 2.58 - 28.4 59

ro ο cn

Results measured on newspaper TAPPI brightness with 5% filling lAPPI opacity with 5% filling Printing ink absorption with 5% filling Percentage reduction of the penetration with 5% filling Percentage retention with

Filling 65.3
89.8

3.7
54.8

cn
cn

CO OO CO

ο cn oo ro ο cn

K) CJ)

ro ο co

ι co c *>

Example no .

Volume of water of reaction; Liter rate of supply of silicate, including Na ₂ SO ^; Liters / minute

, 12

13th

14th

₂ ^

Initial supply duration of silicate sulfate; Minutes duration of the silicate sulphate addition; Minutes silicate concentration * kg7m ^ salt concentration in silicate alum concentration; kg / m * concentration of the silicate in the reactor before the alum feed begins; kg / πκ alum speed; l / minute reaction temperature; ⁰ C alum feed temperature; ⁰ C final slurry; pH ripening temperature ripening time pH value of the pigment Results measured on rubber: tire (away from the streets ) tear strength at 90 minutes; cold tensile strength at 45 minutes; hot abrasion during 60-minute vulcanization flexometer (Firestone); 60 minutes scorching time viscosity

963 963 - - 18.9 18.9 24.23 24.23 4th 4th 39 39 35 35 - - 300 180 183.5 183.5 0.78 0.72 0.23 - 324 324 220 120 21.6 13.2 183.5 183.5 11.38. 5.25 14.18 9.45 57.2 65.6 65.5 54.4 54.4 54.4 65.6 54.4 6.0 6.0 6.0 6.9 57.2 65.6 65.6 54.4 15th 15th 15 " 15th 8.0 7.3 9.6 10.1 730 660 615 585 390 420 "340 350 72.6 62.9 91.2 96.4 263 275 267 272 19.5 19.0 . 17.5 19.5 75 78 70 74

Elongation after vulcanization for 90 minutes Hardness at 90 minutes vulcanization

Results measured on newsprint · ■ TAPPI brightness with 4% filling, lAPPI impermeability with 4% filling

550 550 490 500 71 70 69 69 64.6 64.6 63.6 63.9 87.3 87.4 88.3 87.9 4.8 3.8 4.8 4.9 65.0 72.4 57.2 56.2 51.2 50.0 4-7.5 48.3

Example no .

Volume of water of reaction; Liter speed of supply of silicate, including from NagSO ^; Liters / minute

18th

Initial supply duration of silicate sulfate; Minutes duration the silicate sulfate addition "be; minutes silicate concentration; kg / m * Silicate molar ratio salt concentration in silicate alum concentration; kg / m * Concentration of the silicate in the reactor before the alum feed begins; kg / m3

ω alum speed; l / minute reaction temperature} alum feed temperature; ⁰ C final slurry; pH maturation temperature maturation time

37.8 37.8 37.8 37.8 Ψ 0.741 0.741 0.741 0.741 39 4th 39 4th Ο · C. 35 0 35 85.2 120 85.2 180 3.3 3.3 2.0 2.0 6.0 10.0 3.0 8th 168 240 168 300 85.2 8.39 85.2 13.2 0.945 ' 0.2155 1.134 0.3704 60.0 76.7 '60, 0 76.7 60.0 60.0 60.0 54.4 6.0 7.0 6.0 7.0 60.0 76.7 60.0 76.7 15th 15th 15th 15th

ro ro ο cn

E-56466
Example 19

The reaction vessel is filled with 340 l of water and a sodium silicate-sodium sulfate solution with a silicate concentration of 240 kg / nr and a sodium sulfate concentration of 2 to 6% by weight of the silicate is then added at a rate of 1162.6 ml / min. The temperature of the resulting reaction solution is adjusted to 71.1 ° G and held there. Alum is added to the reaction medium in a concentration of 360 kg / m ^ at a temperature of 71.1 ° C., after the stirrer has been switched on, at a rate of 0.340 to 4, 15 l / min, for 10 seconds or added longer before the start of the sodium silicate-sodium sulfate solution feed. At this point in time, the remaining calculated amount of the sodium silicate-sodium sulfate solution is started to be fed in at its rate of 1162.6 ml / min. After 25 minutes, the silicate solution stream is turned off when the pH of the slurry is above 8.0. The alum continues to be fed until a pH of 7.8 to 8.0 has been reached. If the pH is below 8.0, the addition of the silicate solution is continued until a pH of 8.0 has been reached. A settling or ripening period of 15 minutes is observed, and the pH value is measured again and readjusted to the value 7.8 to 8.0; _s The mass is then fed to the filter, where they degrade to obtain the sodium sulfate and to their residual content to about 3%, is washed with water. The cake obtained, which is solid (thixotropic), is fed to a hammer mechanism and liquefied, whereupon it is spray-dried to a moisture content of 5% at a pigment temperature at the outlet of about 104.4 ° C. The resulting, dry pigment has a pH value of 9-5, and the mass is composed of extremely fine particles, of which proportionally

- 35 -209836/1058

R-56466 ^

massively few are larger than 0.5 microns "

Fine paper results

TAPPI brightness with 9% filling 89.5 TAPPI opacity with 9% filling 87.8

The following substances in the specified amounts represent a normal test composition for testing the here described, exemplary products in rubber, in tires, especially in heavy-duty tires from the way it is used off-road:

Mixed rule for the test; Parts by weight

Tires used off-road

1. Rubber (smoked, natural chew

schukfeln) 100.0

2. Russ (ISAF-Intermediate Super Abrasion

Soot; Huber Corp. Borger, (Texas) 37> 0

J. Pigment (end product of Examples 1 to

18) 20.0

4. Zinc Oxide 5.0

5 · stearic acid 3> 0

6. 6-dodecyl-1,2-dihydro-2,4-trimethyl-

quinoline (Santoflex DD) 0.5

7. Polyalized 1,2-dihydro-2,4-trimethylquinoline (Flextol H) 1.5

8. Pine tar 5.0 9 • Terpenic Acid Mixture (Turgum S) 2.0

10. Benzothiozole disulfide (METS) 0.8

11. Sulfur. 2.8

177.6

The following substances in the specified amounts represent a normal test composition for testing the here described, exemplary products in rubber, which is used in shoe soles, heels and the like:

- 36 2OÖO36 / 1Ob8

Mixed rule for the test; Parts by weight / 100

Rubber used in shoe soles and heels

1. Styrene-butadiene rubber (Plioflex 1778 SBR, non-discoloring low-temperature polymer, which contains 37 parts of light colored naphthenic oil per 100 parts of cold rubber; Mooney viscosity 42-5 * 0 42.8

2. Styrene-butadiene rubber (Plioflex 1510 - water, solid, cold rubber that is solid at low temperature; Mooney viscosity 29-36). 35.0

3. Styrene-butadiene rubber (Plioflex 1950 white, crumbly mixture-of 50 % low-temperature SBS, which contains 37 parts of naphthene oil, and 50 % high-temperature styrene resins) 93.6

4. Zinc oxide 6.6 y, ", *" -. ~ _Λ 23 (synthetic pigment material,

manufactured according to US Pat. No. 2,739,073 as described in

the example 6) presented here 7.0

6. Pigment (products of Examples 1 to 5 and 7 to 18 given here; 70.0

7. Stearic acid 1.0

8. Carbowax - (polyglycol; molecular weight

6000). 4.0

9. Phthalic anhydride 0.65

10. NOBS (special, normal oxydiethylenebenzothiazole) 1.00

11. Captax (mercaptobenzothiazole) · 0.80

12. DOTG (Di-o-tolylguanidine) 0.80 13 · Octamine (diphenylamine and diisobutylamine) 1.0

14. Circo light oil (oil naphthene type) 15.0

15. Sulfur. 2.8

Examples 6 and 9 given above are representative of the best results obtained following the teachings of US Pat U.S. Patent 2,739,073 are available.

In Examples 1 to 14, a sodium silicate with a weight ratio of NaJD: 2.5 ^ ° 2 "was used

- 37 -209836/1058

R-56466 ZY

Examples 15j 16 and 19 show operations and conditions at, "at which the silicate weight ratio of the formula NapO: 3.3 corresponds to Siup. Examples 17 and 18 illustrate Working methods and conditions in which the silicate has a weight ratio of Na20: 2.0 SiO ^. In Examples 15 to 18 were the results obtainable very similar to those results obtained when using the silicate with / the ratio of 2.5 in the inventive Implementation can be obtained.

The invention can be carried out using a wide range of silicates, particularly in the range from about 1.5 to 3-5 SiOp: NapO, based on weight, can be practically carried out.

The test values, which take into account the initial, the minimum and the maximum viscosity and also the scorch time, were made using the Monsanto pendulum disc bheometer won.

- 38 209836/1058

Claims (1)

Pat ent. Claim Process for the manufacture of substances which consist of the oxides of sodium, aluminum and silicon "and as Fillers in paper, paints, rubber reinforcement and the like are useful by reacting sodium silicate and aluminum sulfate in an aqueous medium followed by washing, filtering, drying and recovering of the resulting precipitation in proportion dry, finely divided state, characterized in that one sodium sulfate of said reaction in its course added in an amount equal to at least 1% by weight, Based on the weight of said silicate, at least about 0.1% by weight of said sulfate in the said aqueous Eeaktionsmedium from Eeaktionsmedium provides and wherein said aluminum sulfate of the Eeaktionszone as a special, practically constant flow for a period of time that is at least 10 seconds or more the normal batch time for the supply of separate streams of said aluminum sulfate and said sodium silicate to the reaction medium. 209836/1058