Novel morphologies are provided for aluminosilicate zeolite ion-exchange materials useful for static water softening. The zeolites are provided in the form of large aggregates composed of submicron zeolite crystals. Rapid exchange rates, high hardness ion capacity and increased attrition resistance characterize the zeolite ion exchangers.

The present invention is directed to novel aluminosilicate zeolite structures useful as water softening materials. The unique zeolite materials of this invention can be used to form both regenerable as well as disposable static water softening devices.
Water softening is a process of water treatment by which undesirable cations, in particular, calcium and magnesium, are removed. Water, which contains such cations, is considered hard, wherein hardness is usually expressed as calcium carbonate equivalents in parts per million. The presence of these cations in water is undesirable for household purposes, such as for bathing, cleaning, and laundry, as well as for industrial purposes, such as boiler feed, food processing and chemical processing, because of reactions which form soap scum, boiler scale, and unwanted byproducts. Hard waters have been softened by precipitation processes which involved the use of hydrated lime or cation-exchange processes which involved the use of sodium-cation exchangers such as aluminosilicate zeolites or hydrogen cation-exchangers such as in the form of resins in bead form.
Water softening with ion exchange material such as resin particles or the like is well-known in the art. During the softening process, or service cycle, the ion exchange resin particles acquire hardness inducing ions (Ca2+, Mg2+) from the water in exchange for soft ions, (H+, Na+, K+) which do not induce hardness. After prolonged contact of the resin particles with raw water, the ion exchange capacity of the resin is diminished considerably and periodic regeneration of the resin particles must be accomplished, conventionally by contacting the resin particles with a brine solution, i.e., an aqueous solution of sodium chloride or potassium chloride or the like.
The ion exchange process and the regeneration of the ion exchange material are accomplished in a softener or resin tank of well-known construction, while a separate brine tank is conventionally employed to manufacture brine for use during the regeneration cycle. When is initiated in the system, brine is drawn from the brine tank and passed through the bed of ion exchange material in the softener tank to reverse the exchange of ions and revitalize the bed by removing hardness inducing ions and replacing them with sodium ions, for example, from the brine solution.
In general, there has been a progression in the use of ion exchangers for water softening from initial uses of alumina-silica gels to specific aluminosilicate zeolite materials such as zeolite A to the prevalent use of ion exchange resins at the present time. Among the reasons for this progression is that the alumina-silica gels, although being rather inexpensive, were simply not adequate sequestering agents, having neither a rapid rate of sequestration, capacity or selectivity for the hardness ions to be universally effective water softening agents. Zeolite A eventually replaced the alumina-silica gels inasmuch as this particular zeolite had a fast sequestration rate and high capacity for the hardness ions. Zeolite A was a very effective water softening agent, in particular, for use in regenerable static beds which were regenerated by the addition of brine to the bed which displaced the hardness cations of calcium and magnesium with sodium which allowed the zeolite A bed to be reused. Unfortunately, there was found that with extended use of zeolite A, water turbidity became a problem due to the relatively low attrition resistance of the zeolite granules which broke down into minute particles. These minute particles eventually entered into the water stream. Accordingly, although zeolite A was the standard for fixed bed water softening applications for more than a decade, zeolite A has essentially been displaced by the more expensive organic ion exchange resins. The expense and relatively low capacity of these organic resin materials, however, has prompted a need for finding less expensive and improved hardness ion sequestrants so as to expand the use and market of water softening agents.
In commonly assigned U.S. Pat. No. 5,948,383, the present inventors disclosed the formation of hybrid zeolite-silicate compositions (HZSC) which demonstrate unusual and beneficial properties in complexing multivalent cations. These hybrid materials are prepared by crystallizing high aluminum zeolites from highly alkaline/high silica environments. Chemical analysis indicates that an excess of silica is present in these compositions beyond that inherent in the crystalline frameworks thereof. These hybrid materials demonstrate sequestration capacities for cations such as calcium which not only exceed the amount of zeolitic aluminum available for ion exchange, but, in fact, may exceed the theoretical limit possible for zeolite. While the hybrid zeolite-silicate compositions as disclosed in U.S. Pat. No. 5,948,383 are described as being preferably useful in detergent compositions, the patent also sets forth in very general terms that these hybrid compositions show extreme promise as water softening agents. U.S. Pat. No. 5,948,383 does not otherwise disclose the form that these hybrid zeolite-silicate compositions should take to be useful as water softening agents other than as a powdered composition useful in a detergent composition as a detergent builder. The entire content of U.S. Pat. No. 5,948,383, is herein incorporated by reference.
In commonly assigned U.S. application Ser. No. 09/533,771, filed Mar. 23, 2000, and now U.S. Pat. No. 6,451,283, issued Sep. 17, 2002, the present inventors have found that high aluminum zeolites, including the hybrid zeolite-silicate compositions of U.S. Pat. No. 5,948,383 could be formed into uniform aggregates of submicron zeolite microcrystals by an in-situ process where essentially all of the aggregate material is between 1 and 5 microns. The aggregates of the application are formed from a solid source of aluminum which is included into a high silica/high alkaline environment. The product of the reaction is the formation of submicron crystals grown in-situ into macroscopic aggregates. What has been found is that even though the materials exist as macroscopic aggregates, the ion exchange kinetics are extraordinarily rapid, reflecting the inherent rate of the substituent submicron crystals. The application states that the advantages of maintaining the substituent crystals as coherent macroscopic aggregates is both in the ease of handling when the aggregates are used as a substituent in manufacturing compounds such as detergent mixtures as well as in minimizing pressure drop in flow-through application such as water purification/softening filters. The application also discloses that surprisingly, the rate of sequestration for multivalent cations can be improved even if only low levels of occluded silicate remain the zeolite. The morphology of the zeolites produced appears to have a profound and advantageous effect on hardness removal. Thus, the morphology of the zeolite aggregate containing the submicron crystalline zeolites is crucial to the hardness removal performance and that even if all the silica can be removed, the sequestration rate for complexing multivalent cations can be enhanced over large crystal zeolites.
As further disclosed in U.S. Ser. No. 09/533,771, the elevation of electrolyte concentration in the high silica/high alkaline synthesis mixture used to form the aggregates enhances the water softening properties of the materials. The addition of soluble salts to the synthesis mixture results in the formation of smaller submicron crystals (as manifested by increased exterior surface area) without reduction of aggregate particlesize (typically 1-5 microns). The entire content of U.S. Ser. No. 09/533,771 is herein incorporated by reference.
It is a primary objective of the present invention to produce superior static water softening materials.
It is another object of the present invention to provide water softening materials having improved hardness ion sequestering abilities relative to ion exchangers used past and presently.
It is another object of the present invention to provide a zeolitic water softening material which has excellent multivalent cation sequestering abilities and can replace the expensive organic ion exchange resin materials.
It is a further objective of this invention to produce superior static water softening materials by applying the calcium sequestering abilities of the detergent builders discovered by the present inventors and set forth in the previously discussed commonly assigned U.S. Pat. No. 5,948,383 and U.S. Ser. No. 09/533,771.
Still another object of this invention is to provide a water softening material formed of macroscopic aggregates of submicron zeolite crystals which have superior sequestering abilities and which are resistant to attrition.
Yet another object of this invention is to provide regenerable and disposible water softening materials formed of high aluminum zeolites including hybrid zeolite-silicate compositions.
It has now been found that superior zeolite and hybrid zeolite-silicate static water softening materials can be made by processes disclosed by the present inventors in U.S. Pat. Nos. 5,948,383; 5,942,207 and U.S. patent application Ser. No. 09/533,771. Important to the adaption of this prior technology for forming detergent builders to applications such as static water softening is achieving the appropriate physical form, including in-situ microspheres and larger particles formed as aggregates of submicron crystals, as well as impregnation of smaller aggregates or powders into porous supports such as carbon blocks and paper. Stand alone aggregates of submicron zeolite microcrystals can be formed whereby the aggregate material can be of a size sufficient for use in static water softening. Surprisingly, even though the water softening materials exist as macroscopic aggregates, the exchange kinetics are extraordinarily rapid, reflecting the inherent rate of the substituent submicron crystals.
Water softening materials of this invention can be formed from zeolites such as zeolite A, zeolite X and high aluminum analogs, as well as high aluminum analogs of gismondine, e.g. zeolite B, P and MAP, among others, and the HZSC analogs of such zeolites. The synthesis environment of the hybrid zeolite-silica compositions as described in aforementioned U.S. Pat. No. 5,948,383 has been found to promote the formation of aggregates of submicron zeolite crystals. Such compound aggregates manifest the rapid exchange properties of submicron crystals and the favorable handling properties of macroscopic aggregates. This favorable set of properties results from the high alkalinity of the zeolite synthesis mixture (versus comparable zeolite synthesis) in combination with the propensity of aggregates to retain mechanical integrity in silica-rich environments.
The synthesis of zeolite A has been well established owing to its wide employment as an ion-exchange agent, especially useful in water softening applications such as detergent building. The use of zeolite A as an ion-exchanger has been successful owing to the high aluminum content thereof. With a Si/Al ratio of 1.00, the lowest possible for a zeolite according to the Rule of Lowenstein, high aluminum environments have generally been used in the manufacture of zeolite A. The employment of a silica-enriched environment is counter-intuitive for the synthesis of such high aluminum materials. However, the employment of a silica-enriched environment instills several properties in a synthesis mixture. First, it allows the addition of substantial hydroxide and/or other electrolytes beyond that which would be applicable to a xe2x80x9cnormalxe2x80x9d zeolite synthesis procedure. Such enhanced alkalinity/electrolyte levels promote the nucleation of zeolite seed crystals. Secondly, silica-enhanced environments promote retention of macroscopic particle integrity in the synthesis of aluminosilicates. These two properties, enhanced nucleation and retention of particle integrity, lead to the formation of massive numbers of submicron crystals of the zeolite forming as macroscopic aggregates, especially in in-situ synthesis when a solid source of aluminum is employed, such as metakaolin and/or alumina.
Microcrystalline zeolites formed into aggregates having sizes of at least 20 microns can be formed for use in static water softening processes without the prior turbitity problems which plagued prior art zeolite water softening materials. In particular, in-situ formed aggregates composed of interlocked submicron zeolite crystals are substantially less prone to the attrition problems which reduced the effectiveness of zeolites for water softening despite the greater volumetric capacity of zeolites as compared to the present ion exchange resins. Depending upon the type of zeolite formed, both regenerable and disposable water softening materials can be produced. Importantly, smaller aggregates of the zeolites, including powders, especially HZSC powders can be incorporated into porous base materials such as carbon or paper by impregnation, coating or mixing therewith to expand even further the uses of the zeolite compositions of this invention for static water softening.
The water softening materials of this invention are either present as powdered HZSC materials contained within the pores of a porous matrix or stand alone macroscopic aggregates of submicron zeolite microcrystals of high aluminum zeolites or HZSC analogs and which exhibit rapid ion exchange of hardness cations and have a high exchange capacity. The present invention expands upon the detergent builder technology developed by the present inventors such as disclosed in U.S. Pat. No. 5,948,383 and U.S. Ser. No. 09/533,171 to form aluminosilicate zeolites in novel configurations for highly effective static water softening.
The prior sequestrants (detergent builders) developed by the present inventors were based on the formation of hybrid zeolite-silicate materials. Thus, in addition to zeolites, the ability of silicates to complex ions such as calcium and especially magnesium has long been known and sodium silicate has long been employed as a cheap, low performance detergent builder. Recently, complex silicates have been developed which are claimed to be competitive with high performance zeolites as detergent builders.
The capacity for silicates to complex ions such as calcium and magnesium is inversely proportional to silicate chain length and directly proportional to the electronic charge on that chain fragment. Silicates depolymerize with increasing alkalinity. At moderate pH silicates are polymeric. However, at much higher pH""s silica not only becomes predominantly monomeric, but that monomer may possess multiple charges. These small, highly charged silicate fragments when exposed to solutions bearing multivalent cations, act as very powerful high capacity sequestration agents. The present inventors in commonly assigned U.S. Pat. No. 5,948,383 (Kuznicki, et. al.) disclose isolating and stabilizing substantial concentrations of such charged silicate species within zeolite cages where ions such as calcium are free to enter from an aqueous environment and react with these powerful sequestration agents. The zeolites of this patent have been characterized as hybrid zeolite-silica compositions (HZSC) which demonstrate unusual and beneficial properties in complexing multivalent cations. Such hybrid materials are prepared by crystallizing high aluminum zeolites in highly alkaline/high silica environments. Chemical analysis indicates an excess of silicate in these species beyond that inherent to their crystalline frameworks. Such materials demonstrate sequestration capacities for cations such as calcium which not only exceed the amount of zeolitic aluminum available for ion-exchange, but in fact, may exceed the theoretical limit possible for a zeolite. It is believed that the key mechanism in the effectiveness of these patented materials is derived from the ability of zeolite cages to isolate and stabilize much smaller, more highly charged silicate units. These silicate units are introduced during synthesis of said hybrid zeolite-silica compositions by providing an environment wherein silica in the reaction mixture is depolymerized to highly charged predominantly monomeric units before crystallization begins.
These occluded silicate units are readily visible in 29Si NMR spectra. The zeolite framework and occluded silicate units act in concert, as a new type of hybrid composition, showing properties neither zeolites, silicates nor physical blends of the two demonstrate. In addition to high capacity, these new hybrid compositions demonstrate unusually rapid rates of sequestration, and are, accordingly, considered to be superior detergent builders. In this invention, such hybrid zeolite-silica compositions are formed into static water softening materials.
The inventors have further disclosed in copending, commonly assigned U.S. Ser. No. 09/533,771 that the conditions used to form the hybrid zeolite-silica compositions as described in U.S. Pat. No. 5,948,383, can yield novel zeolite particle morphologies. The zeolite particles which are formed are extremely rapid cationic sequestrants. Prior commercial zeolite A suffers from slow exchange kinetics. This is especially true in cold water where the rate problem renders it essentially ineffective. While zeolite A, by definition, contains equimolar aluminum and silicon in its framework structure and thus the maximum possible zeolite ion-exchange capacity, useful ion-exchange capacity in most processes, however, is a dynamic function based on inherent capacity, ion selectively and kinetics of exchange. While zeolite A is a fixed composition with a fixed exchange capacity and fixed ion selectivities, the kinetics of exchange vary widely with the physical and morphological properties of zeolite A crystals and the aggregates into which they are formed. Microcrystalline zeolite A has long been known to improve exchange kinetics, but these submicron particles have been unusable in real world applications. Submicron microcrystals grown into macroscopic aggregates solves this problem, yielding the kinetic advantages of microcrystalline exchangers and the handling properties of macroscopic ensembles.
U.S. Ser. No. 09/533,771 discloses that the high silica, high alkalinity reaction environments used for producing high aluminum zeolites also produces drastic changes in the morphology of the zeolite particles which are formed. The reaction medium results in nucleation effects which minimize individual crystal sizes without concomitant reduction in overall zeolite particle or aggregate formation. The morphology of the zeolite particles is believed to result in vastly improved rates of cation sequestration without disadvantageously altering particle size.
Thus, zeolite particles with novel morphology compared with a conventional zeolite particle can be formed. A commercial zeolite A typically comprises zeolite crystals of which each is about 1-5 microns. Zeolite A particles which have been formed using the high silica, high alkalinity environments in accordance with the disclosure of U.S. Ser. No. 09/533,771 comprise macroscopic aggregates of zeolite microcrystals. Each aggregate is formed in-situ and has a size of about 1-5 microns similar to the size of the individual crystals of the commercial zeolite A. However, each aggregate is formed of a multiple of submicron zeolite crystals each having a size of from about 0.05 to 0.5 micron. The submicron crystals grown into macroscopic aggregates yield the kinetic advantages of microcrystalline exchange and outstanding cation sequestration rates and the handling properties of the larger size particles. Importantly, no extraneous binder composition is needed to consolidate the zeolite crystals.
The aggregates of microcrystalline zeolites this invention when used as stand alone water softening materials have an average size of at least 20 microns, preferably at least 50 microns and, most preferably, at least 100 microns. Powdered zeolites, such as the HZSC materials discussed above in U.S. Pat. No. 5,948,383 and the 1-5 micron aggregates of microcrystalline zeolites as disclosed in U.S. Ser. No. 09/533,771 are also useful for water softening, but such materials are incorporated into a porous matrix. In general, 5 to 150 wt. % relative to the total weight of the porous matrix includes the smaller aggregates or HZSC powder as mixed with, incorporated in, or coated on the porous matrix such that at least a portion of the zeolite ion-exchanger is present in the pores of the matrix. Preferably, the aggregate or HZSC powder will comprise 10-75 wt. % of the porous matrix.
Compositions of the invention whether powder or aggregate can be prepared by processes disclosed in aforementioned U.S. Pat. No. 5,948,383, and U.S. Ser. No. 09/533,771, the entire contents of each of which have previously been incorporated by reference. Such processes are directed to forming high aluminum zeolites surprisingly from reaction environments containing excess silica. High aluminum zeolites, in general, are defined as having a Si/Al xe2x89xa61.1. Conversely, excess silica in the reaction mixture is herein defined as having a Si/Alxe2x89xa71.1. The zeolites of this invention are provided with the desired morphology by reacting a solid aluminum source such as a dried aluminosilicate gel, powdered gibbsite or more preferably, solid clays such as metakaolin or even raw kaolin with concentrated silicate solutions at pH values above 12 at temperatures ranging from about ambient to about 100xc2x0 C. and at atmospheric pressure. The high silica reaction environment also suppresses the formation of iron oxide, probably by the formation of uncolored iron silicate. This allows xe2x80x9cwhitexe2x80x9d zeolites to be grown from natural reactants such as clays. The ability to use raw reactants such as uncalcined kaolin may have a substantive impact on the economics of zeolite production.
It is preferred, if not crucial, for the preparation of certain zeolites having the desired morphologies, that the aluminum source must be added last to the reaction mixture. Thus, if all the ingredients of the reaction mixture are added together and heated to crystallization temperature, a conventional zeolite will be formed. Thus, neither the hybrid zeolite-silicate compositions nor the aggregates of microcrystalline zeolites may be formed with the desired aluminum content. It is even more desirable to prepare the compositions of this invention by heating the reaction mixture at temperatures of from 50xc2x0 C. to 85xc2x0 C. before the addition of the aluminum source for a period of time of about 30 minutes or longer. The reaction medium also includes an excess of an alkaline source. The term xe2x80x9cexcessxe2x80x9d herein means that the amount of alkaline is greater than that commonly used in the synthesis of the specific zeolite sieve being prepared.
The process conditions as described above containing high levels of silica and excess alkaline surprisingly form high aluminum zeolites. Those zeolites which contain occluded silicate have been characterized as hybrid-zeolite silica compositions in commonly assigned U.S. Pat. Nos. 5,942,207 and 5,948,383. These hybrid zeolite-silica compositions have extraordinary capacity to complex multivalent cations such as calcium.
While not wishing to be bound by any theory of operation of how high aluminum zeolites can be formed from high silica reaction environments, it appears that the large silica content retards aluminum polymerization while the high alkalinity prevents silica polymerization. The result is the formation of 1:1 Si/Al chains. Moreover, heating the reaction mixture for a period of time (for example 30 minutes) prior to aluminum addition allows the silicate to depolymerize and form predominantly occluded silicate units contained within the pores of the zeolite. These small, highly charged silicate fragments are believed to yield the drastically improved sequestering properties of the hybrid zeolite silica compositions.
The zeolite compositions disclosed in U.S. Pat. No. 5,948,383 and which are most useful water softening agents include zeolitic molecular sieves that have a high Al2O3/SiO2 molar ratio, e.g., SiO2/Al2O3 molar ratios of 3 or below, preferably in the range of 2 to 3. Zeolitic species which can be produced by the methods of this patent include type P (also referred to as type B), zeolite A, faujasite type such as high alumina X types, chabazite analogs and mixtures thereof and their HZSC analogs.
After crystallization, the zeolite crystals are washed thoroughly with water, preferably deionized water, to remove sodium and spurious silica from the crystal surfaces. In some cases, some replacement of sodium by hydrogen may take place during washing. The crystals can be washed with solutions other than those of pure water. Up to about 40% by weight of the silica content of the washed crystals is due to the occluded silicate species. Usually up to about 20% by weight of the silica content of the zeolite will be occluded silicate. Thus, the total SiO2 analysis as determined by conventional chemical analytic means exceeds that of the SiO2 that would be expected based on the framework silica content as indicated by x-ray powder patterns and 29Si NMR analysis of the composition. The occluded silicate portion of this silica is readily ascertained from the 29Si NMR peaks at about xe2x88x9281 to xe2x88x9285 ppm.
The zeolite compositions which contain up to 40 wt. % of the total silica as occluded non-zeolite framework silicate have been characterized as hybrid zeolite-silica compositions in commonly assigned U.S. Pat. Nos. 5,942,207 and 5,948,383 and have shown an outstanding capacity to complex multivalent cations. According to these patents, the non-zeolite occluded silicate in amounts of 5 to 40 wt. % relative to the silica content of the composition is important in achieving the added sequestering ability of the composition.
In U.S. Ser. No. 09/533,771, it has been shown that the morphology of the zeolite and analagous HZSC compositions which can be produced from the high silica, high alkaline reaction medium is highly determinative in providing the zeolite with vastly improved sequestration capabilities. By utilizing solid sources of aluminium in the synthesis mixture it has previously been found that aggregates of 1-5 microns in size and containing submicron zeolite crystals could be formed. These macrocrystalline aggregates of microcrystalline zeolites rapidly complex with multivalent cations such as calcium. To form aggregates having a size of at least 20 microns for static water softening, solid aluminum sources having a particle size of at least 5 microns are added to the reaction medium. The excess silicate bridges the aluminum particles to aid in forming the larger aggregates of zeolite crystals. For larger water softening aggregates, larger sizes of solid aluminum sources need to be used. Crystallization from aluminum-containing microspheres, such as kaolin or metakaolin microspheres having the desired final product aggregate size is very useful. Such microspheres are known in the art and can, for example, be prepared by spray drying aqueous kaolin slurries. Such microspheres and methods of making same are well-known, in particular, in the formation of fluid catalytic cracking (FCC) catalysts. After crystallization from the high silica, high alkaline reaction medium, the aggregate of submicron zeolite crystals can be washed to remove sodium and spurious silica from the crystal surfaces to provide a non-zeolite silicate content of up to 40 wt. % of the total silica present in the composition, but preferably to a level of less than 20 wt. %, and, more preferably, to a non-zeolite silicate content 0 to 5 wt. % to yield zeolite compositions showing vastly improved rates of sequestration.
Preferably, the compositions of the zeolitic molecular sieves and occluded silicate whether as a HZSC powder or macroscopic aggregate may be represented by the molar formula:
1.25xc2x10.2ONa2O:1.00Al2O3:xSiO2:yH2O
wherein
x is 2.05 to 2.90 in the case of zeolite B;
x is 2.05 to 2.90 in the case of zeolite A;
x is 2.05 to 2.90 in the case of faujasite;
x is 2.05 to 2.90 in the case of chabazite; and
y is 0-20.
It must be noted that Na2O may be exchanged from such materials by extensive washing and falsely low cation readings may be obtained.
It has been found that the zeolites formed by the processes of this invention and having the desired aggregate morphology, including HZSC aggregate materials can be provided with improved sequestration rates by elevating the electrolyte concentration in the synthesis mixtures beyond that inherent to the caustic necessary for synthesis. In this aspect of the invention, the high silica, high alkaline environment is further provided with an additional electrolyte concentration. Such electrolytes can be salts selected from among the group consisting of nitrates, phosphates, bicarbonates, carbonates, borates, nitrites, sulphates, chlorides, etc. Specific non-limiting examples include sodium carbonate, trisodium polyphosphate (TSPP), sodium borate as well as sodium chloride among others. The salt additions presumably result in the formation of smaller submicron crystals as the zeolite crystals grow around the salt nucleation sites. As the level of salt increases, the number of nucleation sites increase and the size of the individual crystals becomes smaller. The level of added salt or electrolyte into the reaction mixture can vary widely. However, it has been found that amounts of electrolyte corresponding to about 10% to about 100% by weight based on the aluminum-containing reactant yields the increased reaction rate and improvement in surface area of the zeolite which corresponds to the reduction in individual zeolite crystal size. Importantly, it has been found that while the size of the individual submicron crystals becomes smaller, this does not result in any reduction of in-situ aggregate particle size. These aggregates containing the smaller submicron crystals of the zeolite have shown improved hardness sequestration rates. Important also, it has been found that the added electrolytes are not occluded into the zeolite framework as is the excess silica.
An additional advantage of intentionally elevating the electrolyte level in the zeolite synthesis mixtures in accordance with this invention is an enhanced rate of zeolite crystal and aggregate formation. Accordingly, the reaction time can be shortened or the reaction temperature can be reduced, both of which favorably impact on the economics of zeolite manufacture. While this effect has been demonstrated for the high silica, high alkaline environments used to make zeolites in the process of this invention, it is likely that the elevated electrolyte content would be directly applicable to classical zeolite synthesis. Thus, it would be expected that crystals of zeolite grown at elevated electrolyte levels would be smaller than those grown under equivalent conditions without salt addition. For the synthesis of in-situ zeolite particles, this might well result in an alternative means to prepare macroscopic aggregates of microcrystalline zeolites without the need for the high silica, high alkaline environments.
In one of its broadest aspects, the present invention is directed to stand alone static water softening compositions which comprise a macroscopic aggregates of smaller zeolite crystallites. It is preferred that these macroscopic aggregates be formed in the high silica, highly alkaline environments as described previously as it has been found that aggregates of submicron zeolite crystals can be formed in which the zeolite has a high aluminum content and, thus, the maximum cation exchange capacity. However, it may be possible to form aggregates of submicron or smaller zeolite crystals without specifically following the teachings of the previously mentioned U.S. Pat. No. 5,948,383 or copending U.S. Ser. No. 09/533,771. For example, as stated above, the use of additional electrolyte in a zeolite synthesis mixture may well provide numerous nucleation sites on an aluminum containing microsphere or other solid surface to yield in-situ grown zeolite crystallites with the aluminum source. The addition of surfactants or other types of wetting agents to a zeolite synthesis mixture may also result in the formation of aggregates containing microscopic reactant particles from which the active zeolites can be formed. Such water softening materials maintain the advantageous sequestration capabilities of the individual zeolites and, at the same time, provide improved attrition resistance as the individual zeolite crystals are locked into a macroscopic matrix.
The present invention is applicable to the formation of both regenerable and disposable water softening materials formed of the zeolite-silicate powders or macroscopic aggregates of the smaller zeolite crystals including related HZSC materials. Whether the water softening composition is used in a regenerable system or a disposable system, depends upon the particular zeolite formed. For use in regenerable water softening systems, such as used for treating the whole water supply to a household in which a brine solution is used to displace the hardness cations from the zeolite composition for reuse, the zeolite composition should be a rapid water hardness sequestrant and, as well have a high capacity for capturing the water hardness cations. For disposable systems, such as filters for treating water at point of use such as coffee filters, and the like, end of tap devices such as used on the end of a water faucet, the zeolite used must again have a rapid sequestration rate, have a high capacity, and further, be highly selective for the hardness cations such as calcium and magnesium to the extent that such zeolites are not readily re-exchangeable with a sodium or hydrogen ion.
For use as a regenerable zeolite composition, zeolite A in the formation of macroscopic aggregates of submicron zeolite A crystals is particularly useful inasmuch as zeolite A in the aggregate form of this invention rapidly sequesters the hardness cations and has a high capacity for such cation exchange. The zeolite A, however, is not solely selective to calcium such that it can be readily regenerated with a separate salt or brine solution to displace the hardness cations such as with sodium for reuse in water softening applications. The particular type of water softening apparatus used with the stand alone aggregates does not form any part of this invention, and, as such, any known water softening structures which can hold the aggregates and provide for regeneration of the ion-exchange sites on the zeolite can be used. On the other hand, it is found that P-type zeolites are particularly useful for disposable systems since the P-type zeolites are highly selective for multivalent cations such as calcium and magnesium. These cations cannot be readily removed by ion exchange with a separate salt solution.
Further, the HZSC materials in powder form as described in U.S. Pat. No. 5,948,383 are particularly useful for disposable water softening devices in which the hybrid materials are impregnated into porous supports such as carbon blocks or paper. The hybrid zeolite-silica compositions are particularly useful in the non-regenerable, disposable water softening applications because of the unprecedented dynamic calcium capacity of these materials. For example, commercial Amberlite(copyright) exchange resins have only about 1.2 meq/cc actual calcium capacity. HZSC materials with static capacities approaching 10 meq/gm and packing densities approaching 0.7 gms/cc could exceed the capacity of the resins by more than a factor of 5. It is contemplated in this invention that powdered HZSC materials on the order of 1 micron or less can be readily impregnated into or coated onto a porous support and used as a filter or the like for point of use water softening applications. Likewise, smaller, e.g. 1-5 microns, macroscopic aggregates of submicron zeolite crystals including HZSC materials could also be incorporated or otherwise impregnated into porous supports. It is contemplated that macroscopic aggregates of submicron zeolite crystals wherein the aggregates are greater than 5 microns would be more useful as a stand alone water softening material. Such aggregates could also include the zeolite-silicate hybrids or materials in which most, if not all, the occluded silicate has been removed.

Macroscopic aggregates of microcrystalline zeolites for static water softening applications


An antibacterial liquid dish cleaning composition with desirable cleansing properties comprising an alkyl sulfate, a sulfonate surfactant, a solubilizer, a proton donating agent, polyethylene glycol, hydrogen peroxide, a magnesium inorganic salt and water.

This invention relates to a liquid dish cleaning composition which is designed to remove stains from surfaces and also disinfect surfaces like dishes, countertops, sponges, while maintaining good foaming grease cutting, rinsing and mildness properties.
The present invention relates to novel light duty liquid detergent compositions with high foaming and good grease cutting properties as well as disinfecting properties.
The prior art is replete with light duty liquid detergent compositions containing nonionic surfactants in combination with anionic and/or betaine surfactants wherein the nonionic detergent is not the major active surfactant. In U.S. Pat. No. 3,658,985 an anionic based shampoo contains a minor amount of a fatty acid alkanolamide. U.S. Pat. No. 3,769,398 discloses a betaine-based shampoo containing minor amounts of nonionic surfactants. This patent states that the low foaming properties of nonionic detergents renders its use in shampoo compositions non-preferred. U.S. Pat. No. 4,329,335 also discloses a shampoo containing a betaine surfactant as the major ingredient and minor amounts of a nonionic surfactant and of a fatty acid mono- or di-ethanolamide. U.S. Pat. No. 4,259,204 discloses a shampoo comprising 0.8 to 20% by weight of an anionic phosphoric acid ester and one additional surfactant which may be either anionic, amphoteric, or nonionic. U.S. Pat. No. 4,329,334 discloses an anionic-amphoteric based shampoo containing a major amount of anionic surfactant and lesser amounts of a betaine and nonionic surfactants.
U.S. Pat. No. 3,935,129 discloses a liquid cleaning composition containing an alkali metal silicate, urea, glycerin, triethanolamine, an anionic detergent and a nonionic detergent. The silicate content determines the amount of anionic and/or nonionic detergent in the liquid cleaning composition. However, the foaming properties of these detergent compositions are not discussed therein.
U.S. Pat. No. 4,129,515 discloses a heavy duty liquid detergent for laundering fabrics comprising a mixture of substantially equal amounts of anionic and nonionic surfactants, alkanolamines and magnesium salts, and, optionally, zwitterionic surfactants as suds modifiers.
U.S. Pat. No. 4,224,195 discloses an aqueous detergent composition for laundering socks or stockings comprising a specific group of nonionic detergents, namely, an ethylene oxide of a secondary alcohol, a specific group of anionic detergents, namely, a sulfuric ester salt of an ethylene oxide adduct of a secondary alcohol, and an amphoteric surfactant which may be a betaine, wherein either the anionic or nonionic surfactant may be the major ingredient.
The prior art also discloses detergent compositions containing all nonionic surfactants as shown in U.S. Pat. Nos. 4,154,706 and 4,329,336 wherein the shampoo compositions contain a plurality of particular nonionic surfactants in order to affect desirable foaming and detersive properties despite the fact that nonionic surfactants are usually deficient in such properties.
U.S. Pat. No. 4,013,787 discloses a piperazine based polymer in conditioning and shampoo compositions which may contain all nonionic surfactant or all anionic surfactant.
U.S. Pat. No. 4,450,091 discloses high viscosity shampoo compositions containing a blend of an amphoteric betaine surfactant, a polyoxybutylenepolyoxyethylene nonionic detergent, an anionic surfactant, a fatty acid alkanolamide and a polyoxyalkylene glycol fatty ester. But, none of the exemplified compositions contain an active ingredient mixture wherein the nonionic detergent is present in major proportion which is probably due to the low foaming properties of the polyoxybutylene polyoxyethylene nonionic detergent.
U.S. Pat. No. 4,595,526 comprising a nonionic surfactant, a betaine surfactant, an anionic surfactant and a C12-C14 fatty acid monoethanolamide foam stabilizer.
U.S. Pat. No. 6,147,039 teaches an antibacterial hand cleaning composition having a low surfactant content.
It has now been found that a liquid dish cleaning composition which has desirable cleaning and foaming properties that can also be antibacterial can be formulated with a sulfonate surfactant, an alkyl sulfate surfactant, a solubilizer, polyethylene glycol, a magnesium inorganic salt, a proton donating agent, hydrogen peroxide, and water.
An object of this invention is to provide a liquid dish cleaning composition that can also be antibacterial which comprises a sulfate anionic surfactant, a sulfonate anionic surfactants, a solubilizer, polyethylene, hydrogen peroxide, a proton donating agent, a magnesium inorganic salt and water, wherein the composition does not contain any silicas, abrasives, acyl isoethionate, 2-hydroxy-4,2xe2x80x2,4xe2x80x2-trichloridiphenyl ether, phosphoric acid, phosphonic acid, boric acid, alkali metal carbonates, alkaline earth metal carbonates, alkyl glycine surfactant, cyclic imidinium surfactant, or more than 3 wt. % of a fatty acid or salt thereof.
Another object of this invention is to provide a liquid dish cleaning composition with desirable high foaming and cleaning properties which kills also bacteria.
Additional objects, advantages and novel features of the invention will be set forth in part in the description which follows, and in part will become apparent to those skilled in the art upon examination of the following or may be learned by practice of the invention. The objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.
This invention relates to a liquid dish cleaning composition that can also be antibacterial, which comprises approximately by weight:
(a) 16% to 30% of an alkali metal, ammonium or alkaline earth metal salt such as sodium salt of a sulfonate surfactant;
(b) 7% to 16% of an alkali metal or ammonium salt such as sodium of an alkyl sulfate surfactant;
(c) 0 to 5% of a magnesium inorganic salt;
(d) 0 to 10% of a solubilizer;
(e) 0.1% to 5% of a proton donating agent;
(f) 0.05% to 5% of hydrogen peroxide;
(g) 0% to 5% of polyethylene glycol; and
(h) the balance being water, wherein the composition has a pH of 3 to 6, more preferably 3.5 to 5.5 and has a viscosity of 100 to 1,000 cps, more preferably 150 to 500 cps at 25xc2x0 C. using a #2 spindle at 50 rpm as measured on a Brookfield RVTDV-II viscometer, wherein the composition does not contain any grease release agents such as choline, chloride or buffering system which is a nitrogenous buffer which is ammonium or alkaline earth carbonate, amine oxide surfactants, guanidine derivates, alkoxylalkyl amines and alkyleneamines C3-C7 alkyl and alkenyl monobasic and dibasic acids such as C4-C7 aliphatic carboxylic diacids which do not contain a hydroxy group, boric acid, phosphoric acid, zwitterionic surfactant, amino alkylene phosphonic acid and alkyl polyglucoside surfactants and the composition is pourable and not a gel and has a complex viscosity at 1 radsxe2x88x921 of less than 0.4 Pascal seconds.
The anionic sulfonate surfactants which may be used in the detergent of this invention are selected from the consisting of water soluble and include the sodium, potassium, ammonium, magnesium and ethanolammonium salts of linear C8-C16 alkyl benzene sulfonates; C10-C20 paraffin sulfonates, alpha olefin sulfonates containing about 10-24 carbon atoms and C8-C18 alkyl sulfates and mixtures thereof.
The paraffin sulfonates may be monosulfonates or di-sulfonates and usually are mixtures thereof, obtained by sulfonating paraffins of 10 to 20 carbon atoms. Preferred paraffin sulfonates are those of C12-18 carbon atoms chains, and more preferably they are of C14-17 chains. Paraffin sulfonates that have the sulfonate group(s) distributed along the paraffin chain are described in U.S. Pat. Nos. 2,503,280; 2,507,088; 3,260,744; and 3,372,188; and also in German Patent 735,096. Such compounds may be made to specifications and desirably the content of paraffin sulfonates outside the C14-17 range will be minor and will be minimized, as will be any contents of di- or poly-sulfonates.
Examples of suitable other sulfonated anionic detergents are the well known higher alkyl mononuclear aromatic sulfonates, such as the higher alkylbenzene sulfonates containing 9 to 18 or preferably 9 to 16 carbon atoms in the higher alkyl group in a straight or branched chain, or C8-15 alkyl toluene sulfonates. A preferred alkylbenzene sulfonate is a linear alkylbenzene sulfonate having a higher content of 3-phenyl (or higher) isomers and a correspondingly lower content (well below 50%) of 2-phenyl (or lower) isomers, such as those sulfonates wherein the benzene ring is attached mostly at the 3 or higher (for example 4, 5, 6 or 7) position of the alkyl group and the content of the isomers in which the benzene ring is attached in the 2 or 1 position is correspondingly low. Preferred materials are set forth in U.S. Pat. No. 3,320,174, especially those in which the alkyls are of 10 to 13 carbon atoms.
The C8-18 ethoxylated alkyl ether sulfate surfactants have the structure
wherein n is about 1 to about 22 more preferably 1 to 3 and R is an alkyl group having about 8 to about 18 carbon atoms, more preferably 12 to 15 and natural cuts, for example, C12-14 or C12-16 and M is an ammonium cation or a metal cation, most preferably sodium.
The ethoxylated alkyl ether sulfate may be made by sulfating the condensation product of ethylene oxide and C8-10 alkanol, and neutralizing the resultant product. The ethoxylated alkyl ether sulfates differ from one another in the number of carbon atoms in the alcohols and in the number of moles of ethylene oxide reacted with one mole of such alcohol. Preferred ethoxylated alkyl ether polyethenoxy sulfates contain 12 to 15 carbon atoms in the alcohols and in the alkyl groups thereof, e.g., sodium myristyl (3 EO) sulfate.
Ethoxylated C8-18 alkylphenyl ether sulfates containing from 2 to 6 moles of ethylene oxide in the molecule are also suitable for use in the invention compositions. These detergents can be prepared by reacting an alkyl phenol with 2 to 6 moles of ethylene oxide and sulfating and neutralizing the resultant ethoxylated alkylphenol. The concentration of the ethoxylated alkyl ether sulfate surfactant is about 1 to about 8 wt. %.
The proton donating agent is selected from the group consisting of inorganic acids such as sulfuric acid and hydrochloric acid and hydroxy containing organic acid, preferably a hydroxy aliphatic acid, which are selected from the group consisting of lactic acid or citric acid, orthohydroxy benzoic acid , salicylic or glycolic and mixtures thereof.
Polyethylene glycol which is used in the instant composition has a molecular weight of 200 to 1,000, wherein the polyethylene glycol has the structure
HO(CH2CH2O)nH
wherein n is 4 to 52. The concentration of the polyethylene glycol in the instant composition is 0 to 5 wt. %, more preferably 0.1 wt. % to 5 wt. %.
The major class of compounds found to provide highly suitable cosurfactants over temperature ranges extending from 5xc2x0 C. to 43xc2x0 C. for instance are water-soluble polyethylene glycols having a molecular weight of 150 to 1000, polypropylene glycol of the formula HO(CH3CHCH2O)nH wherein n is a number from 2 to 18, mixtures of polyethylene glycol and polypropylene glycol (Synalox) and mono and di C1-C6 alkyl ethers and esters of ethylene glycol and propylene glycol having the structural formulas R(X)nOH, R1(X)nOH, R(X)nOR and R1 (X)nOR1 wherein R is C1-C6 alkyl group, R1 is C2-C4 acyl group, X is (OCH2CH2) or (OCH2(CH3)CH) and n is a number from 1 to 4, diethylene glycol, triethylene glycol, an alkyl lactate, wherein the alkyl group has 1 to 6 carbon atoms, 1methoxy-2-propanol, 1methoxy-3-propanol, and 1methoxy 2-, 3- or 4-butanol.
Representative members of the polypropylene glycol include dipropylene glycol and polypropylene glycol having a molecular weight of 150 to 1000, e.g., polypropylene glycol 400. Other satisfactory glycol ethers are ethylene glycol monobutyl ether (butyl cellosolve), diethylene glycol monobutyl ether (butyl carbitol), triethylene glycol monobutyl ether, mono, di, tri propylene glycol monobutyl ether, tetraethylene glycol monobutyl ether, mono, di, tripropylene glycol monomethyl ether, propylene glycol monomethyl ether, ethylene glycol monohexyl ether, diethylene glycol monohexyl ether, propylene glycol tertiary butyl ether, ethylene glycol monoethyl ether, ethylene glycol monomethyl ether, ethylene glycol monopropyl ether, ethylene glycol monopentyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monopropyl ether, diethylene glycol monopentyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, triethylene glycol monopropyl ether, triethylene glycol monopentyl ether, triethylene glycol monohexyl ether, mono, di, tripropylene glycol monoethyl ether, mono, di tripropylene glycol monopropyl ether, mono, di, tripropylene glycol monopentyl ether, mono, di, tripropylene glycol monohexyl ether, mono, di, tributylene glycol mono methyl ether, mono, di, tributylene glycol monoethyl ether, mono, di, tributylene glycol monopropyl ether, mono, di, tributylene glycol monobutyl ether, mono, di, tributylene glycol monopentyl ether and mono, di, tributylene glycol monohexyl ether, ethylene glycol monoacetate and dipropylene glycol propionate.
The magnesium inorganic salt is selected from the group consisting of magnesium sulfate heptahydrate, magnesium oxide and magnesium chloride and mixture thereof.
The instant light duty liquid nonmicroemulsion compositions can contain about 0 wt. % to about 10 wt. %, more preferably about 1 wt. % to about 8 wt. %, of at least one solubilizing agent selected from the group consisting of a C2-5 mono, dihydroxy or polyhydroxy alkanols such as ethanol, isopropanol, glycerol ethylene glycol, diethylene glycol, propylene glycol, and hexylene glycol and mixtures thereof and alkali metal cumene or xylene sulfonates such as sodium cumene sulfonate and sodium xylene sulfonate. The solubilizing agents are included in order to control low temperature cloud clear properties.
The instant formulas explicitly exclude alkali metal silicates and alkali metal builders such as alkali metal polyphosphates, alkali metal carbonates, alkali metal phosphonates and alkali metal citrates because these materials, if used in the instant composition, would cause the composition to have a high pH as well as leaving residue on the surface being cleaned.
The final essential ingredient in the inventive compositions having improved interfacial tension properties is water. The proportion of water in the compositions generally is in the range of 10% to 95%.
The liquid cleaning composition of this invention may, if desired, also contain other components either to provide additional effect or to make the product more attractive to the consumer. The following are mentioned by way of example: Colors or dyes in amounts up to 0.5% by weight; bactericides in amounts up to 1% by weight; preservatives or antioxidizing agents, such as formalin, 5-bromo-5-nitro-dioxan-1,3; 5-chloro-2-methyl-4-isothaliazolin-3-one, 2,6-di-tert.butyl-p-cresol, etc., in amounts up to 2% by weight; and pH adjusting agents, such as citric acid or sodium hydroxide, as needed. Furthermore, if opaque compositions are desired, up to 4% by weight of an opacifier may be added.
In final form, the instant compositions exhibit stability at reduced and increased temperatures. More specifically, such compositions remain clear and stable in the range of 0xc2x0 C. to 50xc2x0 C., especially 4xc2x0 C. to 43xc2x0 C. Such compositions exhibit a pH of 3 to 6, more preferably 3.5 to 5.5. The liquid cleaning compositions are readily pourable and exhibit a viscosity in the range of 100 to 1000 millipascal.second (mPas.) as measured at 25xc2x0 C. with a Brookfield RVTDV-II Viscometer using a #2 spindle rotating at 50 RPM. Preferably, the viscosity is 150 to 500 mPas.

Liquid dish cleaning compositions containing hydrogen peroxide


A thermoplastic molding composition comprising polycarbonate resin having improved mold release properties is disclosed the composition contain polycarbonate resin and 0.005 to 5.0% relative to the weight of the composition of at least one hydrocarbon in the form of C15-600-methyl-branched alkane. The hydrocarbon is characterized in that the weight proportion of its branches is 5 to 30 percent relative to the weight of carbons in the alkane chain.

The present invention provides polycarbonate moulding compositions with good release properties having methyl-branched alkanes or alkane mixtures as release agents, optionally in addition to other conventional polycarbonate additives.
There are numerous patents and publications describing the releasing action of additives in thermoplastics in general and in polycarbonate in particular. The substances most commonly used as release agents are the esters of long-chain aliphatic acids and alcohols. The use of esters of fatty acid alcohols or polyols, such as e.g. pentaerythritol with fatty acids, such as are described in DE 33 12 158, EP 100 918, EP 103 107, EP 561 629, EP 352 458, EP 436 117, or, using guerbet alcohols, U.S. Pat. No. 5,001,180, DE 33 12 157, U.S. Pat. No. 5,744,626, is mentioned here by way of example. All of these esters have the disadvantage that they have a tendency towards interesterification with the polycarbonate due to impurities having a catalytic effect and to the processing temperature. This becomes particularly apparent at the high melt temperatures necessary for short cycle times.
Other release agents that do not have this disadvantage, such as long-chain ketones, tend to form chromophores due to self-condensation and are poorly accessible (EP 100 918).
Siloxanes, which are likewise used (U.S. Pat. No. 4,536,590, U.S. Pat. No. 4,390,651, U.S. Pat. No. 3,751,519), possess an adequate temperature resistance but are very poorly compatible with polycarbonate and in the concentrations required to be effective they lead to haze.
xcex1-olefin polymers (EP 561 630, EP 230 015) with residual double bonds (DE 32 44 499) are not colourfast and in the case of hydrogenated systems, as with the long-chain alkanes (U.S. Pat. No. 4,415,696), there is a compatibility problem with polycarbonate, and the wax-like, often partially liquid partially waxy consistency of these products is restricting.
Warp-free demoulding of polycarbonate mouldings with no deterioration in the very high-grade surface represents an ever greater challenge due to the demands for shorter cycle times and higher processing temperatures at a time when shapes are becoming ever more complex. Many problems can commonly be overcome only with a tailor-made release agent formulation. There is therefore a continual need for new potential release agents. The object was therefore to find release agents that do not tend towards interesterification with the polycarbonate nor form deposits on the mould and that do not lead to haze or discoloration in the effective concentrations.
The object was therefore to develop a readily releasing moulding composition which in addition to outstanding mould release properties and transparency also has satisfactory temperature resistance without discoloration or interesterification.
The object was achieved by the use of methyl-branched alkanes which have an adequate solubility and stability in polycarbonate.
The present invention provides polycarbonate moulding compositions containing hydrocarbons having 15 to 600 carbon atoms, whereby these hydrocarbons are contained in quantities of 0.005 to 5.0 wt. % relative to the weight of the entire moulding composition, and these hydrocarbons consist of methyl-branched alkane chains, whereby they display a proportion by weight of branches of between 5 wt. % and 30 wt. % relative to the carbons in the chain.
The preferred content of hydrocarbons is 0.01 to 2.0 wt. %, most particularly preferably 0.02 to 1.0 wt. %.
Hydrocarbons having 15 to 100 carbon atoms are likewise preferred, with those having 15 to 40 carbon atoms being particularly preferred.
The hydrocarbons according to the invention particularly preferably consist of alkanes, of which the carbons in the branching methyl groups have a proportion by weight relative to the carbons in the chain of between 10 wt. % and 30 wt. %; particularly preferred are those constituted from isoprene units, in this case before hydrogenation, particularly preferably from over 90% hydrogenated isoprene units, most particularly preferably from over 95% hydrogenated isoprene units, optionally using comonomers, particularly 2,3-dimethyl butadiene, butadiene, propene and/or isobutene, in the range from 0 to 50 mol % (relative to the isoprene units), but particularly those that are formally constituted from isoprene units before saturation of the double bonds, whereby those containing 15, 20, 25, 30, 35 or 40 C atoms or mixtures thereof are preferred, squalane (30 C atoms) being most particularly preferred.
The polycarbonate moulding compositions can optionally be supplemented with other additives conventionally used in polycarbonate, such as e.g. heat stabilisers, UV/IR stabilisers, other release agents, flame ratardants, antidripping agents, lubricants, flow promoters, fillers, colorants such as pigments or colour concentrates, glass fibres, fillers and blend components such as ABS, SAN, EPDM or polyesters based on terephthalic acid and diols.
The moulding compositions according to the invention can be contaminated with impurities contained in the individual components of the moulding composition due to their synthesis, working up, processing and storage, together with contamination originating during production or processing of the moulding compositions according to the invention. The aim is to work with products that are as clean as possible, however.
Alkanes according to the invention are those of natural or synthetic origin having lateral methyl groups and a total of 15 to 600 carbon atoms, preferably 15 to 100 carbon atoms, whereby the patent also provides mixtures of these hydrocarbons. Hydrocarbons are preferred which are constituted formally or by actual synthesis of 50 to 100 mol % of isoprene units, i.e. which contain this C5 unit after saturation of the double bonds remaining after polymerisation, with the proviso that the carbons in the branching methyl groups have a proportion by weight, relative to the carbons in the chain, of between 10 wt. % and 30 wt. %, preferably between 10 wt. % and 30 wt. %. Comonomers such as can be used in addition to isoprene are those such as are conventionally used in rubber production and polyolefin chemistry, particularly 2,3-dimethyl butadiene, butadiene, propene and/or isobutene. Such saturated aliphatics that arise purely mathematically from isoprene via xe2x80x9chead-headxe2x80x9d or xe2x80x9chead-tailxe2x80x9d linkage before saturation of the remaining double bonds are particularly preferred, whereby both linkage types can also occur side by side, particularly squalane.
Mixtures of the hydrocarbons according to the invention can also be used, optionally with admixtures of other alkanes, including linear types, of between 0 and 30 wt. % relative to the amount of alkanes according to the invention.
The alkanes used should have the lowest possible residues of double bonds; iodine values of below 10, ideally below 5, are desirable.
The alkanes according to the invention are commercial and can be acquired in the chemicals trade.
Thermoplastic, aromatic polycarbonates in the sense of the present invention are both homopolycarbonates and copolycarbonates; the polycarbonates can be linear or branched by known means.
Part, up to 80 mol %, preferably from 20 mol % to 50 mol %, of the carbonate groups in the polycarbonates that are suitable according to the invention can be replaced by aromatic dicarboxylic acid ester groups. Such polycarbonates, which contain both acid radicals of the carbonic acid and acid radicals of aromatic dicarboxylic acids incorporated into the molecular chain, are, strictly speaking, aromatic polyester carbonates. For the sake of simplicity they are subsumed under the generic term of thermoplastic, aromatic polycarbonates in the present application.
The polycarbonates for use according to the invention are produced by known means from diphenols, carbonic acid derivatives, optionally chain terminators and optionally branching agents, whereby a part of the carbonic acid derivatives is replaced by aromatic dicarboxylic acids or derivatives of dicarboxylic acids in order to produce the polyester carbonates, depending on the carbonate structural units in the aromatic polycarbonates to be replaced by aromatic dicarboxylic acid ester structural units.
Details concerning the production of polycarbonates have been set down in hundreds of patent specifications over the last 40 years or so. Reference is made here by way of example only to
Schnell, xe2x80x9cChemistry and Physics of Polycarbonatesxe2x80x9d, Polymer Reviews, Volume 9, Interscience Publishers, New York, London, Sydney 1964;
D. C. Prevorsek, B. T. Debona and Y. Kesten, Corporate Research Center, Allied Chemical Corporation, Morristown, N.J. 07960: xe2x80x9cSynthesis of Poly(ester Carbonate) Copolymersxe2x80x9d in Journal of Polymer Science, Polymer Chemistry Edition, Vol. 19, 75-90 (1980);
D. Freitag, U. Grigo, P. R. Mxc3xcller, N. Nouvertne"", BAYER AG, xe2x80x9cPolycarbonatesxe2x80x9d in Encyclopedia of Polymer Science and Engineering, Volume 11, Second Edition, 1988, pages 648-718 and finally
Drs U. Grigo, K. Kircher and P. R. Mxc3xcller xe2x80x9cPolycarbonatexe2x80x9d in Becker/Braun, Kunststoff-Handbuch, Volume 3/1, Polycarbonate, Polyacetale, Polyester, Celluloseester, Carl Hanser Verlag Munich, Vienna, 1992, pages 117-299.
The thermosplastic polycarbonates including the thermoplastic, aromatic polyester carbonates have average molecular weights Mw (obtained by measuring the relative viscosity at 25xc2x0 C. in CH2Cl2 and at a concentration of 0.5 g per 100 ml CH2Cl2) of 12,000 to 120,000, preferably 15,000 to 80,000 and particularly 15,000 to 60,000.
Suitable diphenols for production of the polycarbonates for use according to the invention are, for example, hydroquinone, resorcinol, dihydroxydiphenyl, bis(hydroxyphenyl) alkanes, bis(hydroxyphenyl) cycloalkanes, bis(hydroxyphenyl) sulfides, bis(hydroxyphenyl) ethers, bis(hydroxyphenyl) ketones, bis(hydroxyphenyl) sulfones, bis(hydroxyphenyl) sulfoxides, xcex1,xcex1xe2x80x2-bis(hydroxyphenyl) diisopropyl benzenes, and ring-alkylated and ring-halogenated compounds thereof.
Preferred diphenols are 4,4xe2x80x2-dihydroxydiphenyl, 2,2-bis(4-hydroxyphenyl)-1-phenylpropane, 1,1-bis(4-hydroxyphenyl) phenyl ethane, 2,2-bis(4-hydroxyphenyl) propane, 2,4-bis(4-hydroxyphenyl)-2-methyl butane, 1,1-bis(4-hydroxyphenyl)-m/p diisopropyl benzene, 2,2-bis(3-methyl-4-hydroxyphenyl) propane, bis(3,5-dimethyl-4-hydroxyphenyl) methane, 2,2-bis(3,5-dimethyl-4-hydroxyphenyl) propane, bis(3,5-dimethyl-4-hydroxyphenyl) sulfone, 2,4-bis(3,5-dimethyl-4-hydroxyphenyl)-2-methyl butane, 1,1-bis(3,5-dimethyl-4-hydroxyphenyl)-m/p-diisopropyl benzene, 2,2- and 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethyl cyclohexane.
Particularly preferred diphenols are 4,4xe2x80x2-dihydroxydiphenyl, 1,1-bis(4-hydroxyphenyl) phenyl ethane, 2,2-bis(4-hydroxyphenyl) propane, 2,2-bis(3,5-dimethyl-4-hydroxyphenyl) propane, 1,1-bis(4-hydroxyphenyl) cyclohexane, 1,1-bis(4-hydroxyphenyl)-m/p-diisopropyl benzene and 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethyl cyclohexane.
These and other suitable diphenols are described in, for example, U.S. Pat. Nos. 3,028,635, 2,999,835, 3,148,172, 2,991,273, 3,271,367, 4,982,014 and 2,999,846, in German laid-open applications 1 570 703, 2 063 050, 2 036 052, 2 211 956 and 3 832 396, French patent specification 1 561 518, in the monograph xe2x80x9cH. Schnell, Chemistry and Physics of Polycarbonates, Interscience Publishers, New York 1964xe2x80x9d and in the Japanese laid-open applications 62039/1986, 62040/1986 and 105550/1986.
In the case of homopolycarbonates only one diphenol is used, in the case of copolycarbonates several diphenols are used, whereby the bisphenols used, like all other chemicals and auxiliary substances added to the synthesis, can of course be contaminated with impurities originating from their own synthesis, although it is desirable to work with the cleanest possible raw materials.
Suitable chain terminators are both monophenols and monocarboxylic acids. Suitable monophenols are phenol, alkyl phenols such as cresols, p-tert.-butyl phenol, p-n-octyl phenol, p-iso-octyl phenol, p-n-nonyl phenol and p-iso-nonyl phenol, halophenols such as p-chlorophenol, 2,4-dichlorophenol, p-bromophenol and 2,4,6-tribromophenol, or mixtures thereof.
Suitable monocarboxylic acids are benzoic acid, alkyl benzoic acids and halobenzoic acids.
Preferred chain terminators are the phenols having the formula (I)
R6xe2x80x94Phxe2x80x94OH xe2x80x83xe2x80x83(I)
where R6 stands for H or a branched or unbranched C1-C18 alkyl radical.
The quantity of chain terminators to be used is 0.5 mol % to 10 mol %, relative to moles of diphenols used in each case. The chain terminators can be added before, during or after phosgenation.
Suitable branching agents are the trifunctional or more than trifunctional compounds known in polycarbonate chemistry, particularly those having three or more than three phenolic OH groups.
Suitable branching agents are, for example, phloroglucinol, 4,6-dimethyl-2,4,6-tri(4-hydroxyphenyl) heptene-2,4,6-dimethyl-2,4,6-tri(4-hydroxyphenyl) heptane, 1,3,5-tri(4-hydroxyphenyl) benzene, 1,1,1-tri(4-hydroxyphenyl) ethane, tri(4-hydroxyphenyl) phenyl methane, 2,2-bis[4,4-bis(4-hydroxyphenyl) cyclohexyl] propane, 2,4-bis(4-hydroxyphenyl isopropyl) phenol, 2,6-bis(2-hydroxy-5xe2x80x2-methylbenzyl)-4-methylphenol, 2-(4-hydroxyphenyl)-2-(2,4-dihydroxyphenyl) propane, hexa(4-(4-hydroxyphenyl isopropyl) phenyl) orthoterephthalic acid ester, tetra(4-hydroxyphenyl) methane, tetra(4-(4-hydroxyphenyl isopropyl) phenoxy) methane and 1,4-bis(4xe2x80x2,4xe2x80x3-dihydroxytriphenyl) methyl) benzene, as well as 2,4-dihydroxybenzoic acid, trimesic acid, cyanuric chloride and 3,3-bis(3-methyl-4-hydroxyphenyl)-2-oxo-2,3-dihydroindole.
The quantity of branching agents optionally to be used is 0.05 mol % to 2.5 mol %, relative again to moles of diphenols used in each case.
The branching agents can either be included with the diphenols and chain terminators in the aqueously alkaline phase or added ahead of phosgenation dissolved in an organic solvent.
All these measures for producing polycarbonates are familiar to the person skilled in the art.
Suitable aromatic dicarboxylic acids for production of the polyester carbonates are, for example, phthalic acid, terephthalic acid, isophthalic acid, tert.-butyl isophthalic acid, 3,3xe2x80x2-diphenyl dicarboxylic acid, 4,4xe2x80x2-diphenyl dicarboxylic acid, 4,4-benzophenone dicarboxylic acid, 3,4xe2x80x2-benzophenone dicarboxylic acid, 4,4xe2x80x2-diphenyl ether dicarboxylic acid, 4,4xe2x80x2-diphenyl sulfone dicarboxylic acid, 2,2-bis(4-carboxyphenyl) propane, trimethyl-3-phenyl indane-4,5xe2x80x2-dicarboxylic acid.
Of the aromatic dicarboxylic acids, terephthalic acid and/or isophthalic acid are particularly preferably used.
Derivatives of dicarboxylic acids are the dicarboxylic acid dihalides and the dicarboxylic acid dialkyl esters, particularly the dicarboxylic acid dichlorides and the dicarboxylic acid methyl esters.
The carbonate groups are replaced by the aromatic dicarboxylic acid ester groups substantially stoichiometrically and also quantitatively, such that the molar ratio of the reaction partners is also found in the final polyester carbonate. The aromatic dicarboxylic acid ester groups can be incorporated both randomly and in blocks.
Preferred production methods for the polycarbonates for use according to the invention, including the polyester carbonates, are the known interfacial method and the known melt interesterification method.
Phosgene is preferably used as carbonic acid derivative in the first case, diphenyl carbonate in the second case. Catalysts, solvents, working up, reaction conditions, etc., for polycarbonate production are adequately described and known in both cases.
The moulding compositions according to the invention are produced by adding the alkanes according to the invention to the melt during synthesis or in the case of the phase interfacial process to one of the working up or concentration steps, or alternatively in solution by adding the alkanes according to the invention and optionally other additives simultaneously or successively to the polycarbonates dissolved in a polycarbonate solvent and then evaporating off the polycarbonate solvent.
The present invention therefore also provides a process for the production of the polycarbonate moulding compositions according to the invention, characterised in that polycarbonates are mixed with the alkanes according to the invention either simultaneously or successively, either in bulk or in solution, and the mixtures are then either melt compounded at temperatures of between 260xc2x0 C. and 360xc2x0 C. or melt extruded at temperatures of between 250xc2x0 C. and 320xc2x0 C. or the polycarbonate solutions are evaporated and the mixture obtained then pelletised.
The polycarbonate moulding compositions according to the invention can also contain the conventional additives, such as glass fibres, fillers, pigments, UV and heat stabilisers, antioxidants and other release agents in the conventional quantities for thermoplastic polycarbonates.
Suitable glass fibres are all commercial grades and types of glass fibers, in other words chopped strands and milled fibres, provided that they are treated by suitable means to make them compatible with polycarbonates.
The glass fibres used to produce the moulding compositions are made from low-alkali glass. According to DIN 1259 low-alkali glass is an aluminium-boron-silicate glass with an alkali oxide content of below 1 wt. %. Glass fibres having a diameter of 8 to 20 xcexcm and a length of 3 to 6 mm (chopped strands) are conventionally used. Milled fibres can also be used, as can suitable glass beads.
Flame retardants such as are used e.g. in polycarbonate and can also be used in the moulding compositions according to the invention are alkali salts of organic and inorganic acids, particularly sulfonic acids such as e.g. sodium or potassium perfluorobutane sulfonate, potassium hexafluoroaluminate, sodium hexafluoroaluminate, potassium diphenylsulfone sulfonate, sodium-2-formylbenzene sulfonate, sodium (N-benzene sulfonyl) benzene sulfonamide, often in combination with other flame retardants such as halogenated organic compounds, cryolite and Teflon. Mixtures of the cited additives are likewise suitable.
These conventional additives can be added by known means to the polycarbonates to be rendered flame resistant, either together with the components according to the invention or afterwards.
The polycarbonate moulding compositions according to the invention can be processed into moulding on the conventional processing machines by known methods under the conventional processing parameters for polycarbonate.
The invention therefore also provides parts such as mouldings and semi-finished products made from the moulding compositions according to the invention.
The mouldings are used for example in the electrical, electronics, lighting, computer, construction, automotive and/or aviation sector.
The invention therefore also provides the injection moulded and extruded articles produced from them, such as e.g. optical data stores, such as CDs, DVDs and developments thereof, films, sheets, twin-wall sheets, lamps, housings for electrical appliances, computers or motor vehicle equipment such as discs and headlamp diffusers, instrument panel components, trim and the like, particularly transparent applications such as CDs, DVDs and developments thereof, films, sheets, twin-wall sheets, lamps, or motor vehicle equipment such as discs and headlamp diffusers, particularly optical data stores, such as CDs, DVDs and developments thereof.

Polycarbonate molding compounds with good demolding properties and molded bodied and semifinished products produced from the same