DE2341570A1 - IMPROVED WHEAT STARCH PRODUCT AND METHOD FOR MANUFACTURING IT - Google Patents

Description

Dr. Inn · Γ3ΐ \) ur. F. Dr. ror. nat. B. Dr, rer. nat. D Dijl. -In O. Ch.

RTiDiES REDIES TURK & GILLE 2341570

PATENT LAWYERS

4 Düsse-May-Benralh 3 Erich-Oüerihauer-StraBö DRK-Ärzt-3hau & Garath Telephone (C211) 701033 Telex 85CL ¹ 841 rrtg d Telegram: R-3turc; ^: Düsseldorf

49. OOG - Dr.T
Dr.H / bgr

Improved wheat starch product and Method 2u of its manufacture

The invention relates to a new possibility of expansion the usability of certain grain products, especially wheat starch, and the usability their generally spherical granular shape.

For the preparation of StHrkekörnchen a uniform size, which are used on a wider area, a separation is applied by the wet process. This product is used in particular as a substitute for the more expensive and rarer (foreign) root starch Arrowroot (Haranta starch or Pfeilv. Short starch). In addition, the fine grain corn starch obtained as a by-product of the separation process can be used as a rice starch substitute and to improve the structure of certain bakery products

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Deutsche Bank AG., Düsseldorf-Garath. Account no. 6033516 - Stadtsparkassa Düsseldorf, account no. SSOOO 9S4 postal check Cologne 666

if a fine-grained structure or texture is desired.

A few attempts have already been made to separate υ πι V.'uizen starch granules from one another according to their size, but the separation methods are usually through air classification (sorting) of the starting point in a different way with the entire wheat burrow in the dry addition -: id carried out. JK Knight has described such a method in his work "The Chemistry of Wheat Starch &Gluten", published by Leonliard Hill, London (1965). According to the Knight method, dry separation or dry sorting is only partially successful. Also from Anderson and grj ffin was a method for the separation of gluten and starch. Flour described. However, this does not describe any separation of the wheat starch granules according to size using a wet process (cf. RA Anderson and EL Griffin in "Die Strength" 6 (14), pp. 210-212 (1962)).

Hoseny et al. made use of a sieving method for the preparation of a fine grain wheat starch fraction which was tested in the "Hard Winter V Heat Laboratory" Manhattan, Kansas (see "Cereal Chemistry," 4J3, 191-201 (1971)). They observed no change in gelatinization temperature when comparing wheat of a primary quality (with mixed grain sizes) with a fine grain wheat. The suitability of these samples for bread-making was judged to be the same, so that it was concluded that the grain size does not determine the bread-making ability of a wheat starch. Sollars et al. but claimed that the size of the starch granules certainly plays a dominant role in the ability of the restored flours for baking (see FIG. Sollarn et al. "Wheat and Flour Starch in" in Cereal Chemistry "48,

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397-410, especially p. 408 (1971)).

D. The from Hoseny et al. method used to produce

Fine grain wheat starch also included a sieving method, dio apparently a combination of fine-grain starch particles, broken. Particles and pentosans provided. It is true no greetings given, but Hoseny et al. Is photomicrographs indicate that a certain amount of coarser grains Particles' got into the product (cf. ibid., Fig. 1 "SGW" P. 196).

In a review recently edited by Y. Porneranz under the title "Wheat, Chemistry and Technology", published by The American Assn. Cereal Chemists, St. Paul Chin. (197J) (especially Chapter 7 "Carbohydrates" by BL Appolonia and KA Gilles, pp. 332, 336 and 344) ^ the microscopic appearance of wheat starch granules is described in detail. The presence of two fundamentally different types of grain has been identified therein as "large lenticular" grains, most of which are 20 to 35 microns in diameter, and small spherical grains having diameters mostly within the range of 2 to 10 microns. It is also stated therein that the larger grains in the wheat starch, although they represent only 12.5 per cent of the total health, make up the greater part of the weight and the greater part of the surface. Regarding the physical properties of the wheat starch, the author states that it was observed that the swelling of the granules and the loss of birefringence occurred first in the larger granules, and that this wheat starch was observed to gelatinize over a range of temperatures.

In U.S. Patent 2,642,185, F.J. Fontein a ver

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drive described for refining a starch suspension. Although this method superficially corresponds to the invention Procedure is similar, but there are some significant differences. One example is Fontain only interested in making sturgeon grains that are less than 7 microns in size. The larger starch granules are peeled off and subjected to further treatment subject. Those granules that are about 20 microns in size and larger are just the ones at most important of the present invention as a technical product are. The smaller particles with a size below 12 microns are in the separation system according to the invention or Sorting system can only be used as a lifting product.

In the Fontain process, a cyclone separation system is used used, in which the starch granules below 7 microns are collected and then further refined, practically all coarser particles are removed. The main goal of this method is to be a nifty one To obtain starch with a uniform grain size of less than 10 microns and preferably less than 7 microns. In Fontain's circulation system, the overflow from the top section or the base opening becomes these hydrocyclones used and introduced into a second hydrocyclone. The overflow from the upper (base) opening of the Second hydrocyclone is collected in the form of a fine grain product (less than 7 microns in size).

In contrast to this, in the method according to the invention in the first hydrocyclone a washed wheat starch slurry of a primary quality with a very specific one Viscosity are introduced. The effluent from the apex opening of the first hydrocyclone is collected and used as a feedstock introduced into a second hydrocyclone so that

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the feed for the second hydrocyclone is primarily a coarse-grained, partially sorted (separate) Starch slurry acts. The viscosity will very carefully adjusted before the drain (underflow) is introduced into the second hydrocyclone. at the desired product is the effluent from the second hydrocyclone.

At the initial charge for the system according to the invention it is a washed wheat starch slurry of a primary quality, so that the overflow fractions also have a perfectly uniform grain size with a particle size within the range of about 3 to 12 microns. This overflow fraction is collected in each case and can be used in the fields where a

fine-grain wheat starch is used. This fine-grained by-product can be used, for example, as a replacement for fine-grained Rice starch can be used.

The process according to the invention gives an extraordinary good coarse-grained starch product suitable for use as a protective particle in a surface coating is particularly well suited for carbon-free copier or carbonless paper and that certain advantageous Has physical properties that distinguish it from the fine-grained Differentiate product. The coarse grain product (large grain product) can improve its desired Properties can be further modified. For example, its heat resistance by a certain Networking, as it is explained in more detail below, can be improved.

In U.S. Patent 2,504,962 there is a method for Separating starch from flour - using a range

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described by seven. However, there is no separation or /. Sorting of starch granules according to the size according to a wet process mentioned. U.S. Patent 3,489,605 describes a device for separating gluten from starch. The aim of this patent is to increase the strength remove altogether without attempting to classify the starch granules by size. In the US Patent 3,354,046 is the use of chemicals or enzymes as an aid in the filtration of Starch products described. In dr.r openly lied to Dutch Patent application 70 05 045 is a pressure sensitive coating on a copy or. Carbonless paper described. The coating contains microencapsulated fiber particles that then, when under the pressure of a picture writing instrument: - break, a copy of the image on an adjacent paper surface transfer.

There is a protective material for this specially coated paper with a relatively uniform microparticle size required, which is "slightly larger" than the encapsulated Paint particles to prevent the premature breakage of the microcapsules containing the paint during paper coating to prevent storage or handling of the coated paper. Various starch particles are described in it, which can be used as protective material and it is stated therein that Arrowroot starch granules because of their uniform, relatively large grain sizes on the order of 25 to 50 microns are preferred. Wheat starch granules were not rated as well as Arrowroot as their grain size is within the range of 2-35 microns. In this Dutch patent application are barley and rye starch granules neither mentioned nor rated. Obviously it became No advantage is seen in giving the starch protection granules described therein to a thermal or chemical treatment

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undergo.

In summary, the conclusion is drawn from this patent application draw that the best protective material for pressure sensitive Copy or carbonless paper native (natural). Arrowroot starch granules and that after potato and sago starch, the WeizciisLürke is the fourth choice. The provision A sufficient supply of Arrowroot strength poses a serious obstacle because it is primarily Obtained from the root of a plant (Haranta arundinacea) will, 'which is on the island of St. Vincent in the West Indies. The Arrowroot Strength gained in this way is mostly used for special foods for liinder and Ill vtrv / ends and is relatively expensive.

There is, therefore, an urgent need for a less expensive protective material for pressure-sensitive "copiers". Carbonless papers. The material should meet all of the above requirements and should be in abundance be available. However, to date no attempts have been made to achieve a uniform, coarse-grained starch product a grain starch slurry, e.g. a wheat, barley or rye starch slurry, of primary quality with the aim of obtaining a product in which 9 9% by weight of the granules have a size within the Ranges from 12 to 40 and at least 22 percent by weight of the granules are about 22 microns or larger in size.

In the recently published abstract mentioned above ("Wheat: Chemistry and Technology") describes the effects caused by the intermolecular connection of the starch granules can be obtained (see p. 344). However, no difference is mentioned in this when the granules are in terms of their size have been classified (sorted) first. The observed

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The main effect was apparently the inhibition of the grain swelling and the prevention of the collapse of the gelatinized pastes, made from such crosslinked starch granules. The degree of crosslinking proposed therein lies in the The order of magnitude of one crosslinking per 2,000 glucose units.

Recently it has been in the literature and in other patents except for U.S. Patent 2,642,185 to Fontein of the hydrocyclone separator, but it is assume that this device has never been used in a system with such a flow diagram as the subject of the present invention, which has been used with the aim of being relatively free of impurities to separate and obtain coarse-grain starch from primary quality, which is particularly good as a protective material in pressure-sensitive, microencapsulated paper coatings. U.S. Patent 3,251,717 uses Hydrocyclones in combination with centrifuges to remove the soluble material in a maelstrom thickening stage described in a corn starch * wet milling process. However, it is not mentioned or suggested that the starch granules can also be sorted by size or separated from each other. From Whistler et al. is in loc.cit., Volume II, P. 42, also the hydrocyclone separation described, the purpose of this process is, however, the Schweierenfendosperm- und Separate fiber particles from the starch-containing lighter germ. The germ is then washed to remove the starch, without attempting to further separate the starch granules according to size.

In summary, it can be stated that the aim of most of the known methods is to replace those already in place

. Corn starch

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Methods for separating starch from gluten and fibers of the coarse-grained seeds. For the wet milling of wheat, the most common method was first make a dough from the wheat flour and water in the right proportions to form a dough moist gluten, which is usually ductile, tough and elastic. The wet gluten is then molded into a dough and then the gluten is separated from all the rest of the starch, regardless of the grain size will. The Fontein US patent mentioned above goes a step further and collects the uniform small ones Starch particles less than 10 microns in size, however, ignore the larger particles.

The present invention now relates to a specially processed corn starch, which is made from grains of corn, wherein 99% by weight of the product consist of starch granules larger than 12 microns in size and at least 22 percent by weight of these granules are greater than 22 microns in size. The invention also relates to separation of the starch granules by the wet process for the production of this coarse-grained starch. To have an effective separation a slurry of native colloidal corn starch of primary quality in two different portions with the formation of separate grain size classifications

used a number of hydrocyclone separators in combination with a centrifugal separator. It is for that For the success of the system, it is important that the process be carried out with a prime grade starch slurry which is not subjected to drying and reslurrying has been. The system has all the advantages of a wet processing system and a separation of the starch granules into two uniformly sized classifications is achieved.

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keep. About 99 percent by weight of the starch granules with a Size of 12 microns or more are used by the granules smaller size and about 55 percent by weight of these larger granules, consisting of granules having a size of 22 microns or more.

By providing a coarse-grained specialty wheat starch the uses for wheat-larch become considerable expanded. This new starch is particularly suitable as a replacement for the relatively rare and expensive Arrov / -root starch, as a protective material in coated, carbon-free Copy paper is used, in which one in microcapsules cingeschlosscno for the production of image copies Color is used. The inventive new coarse-grained Wheat starch can also be used as a substitute for arrowroot starch grains used in a lithographic anti-offset powder, that is brushed or sprayed onto freshly lithographed sheets of paper that can be stacked on top of one another, without blurring or transferring the image occurs.

The invention is explained in more detail below with reference to the accompanying drawings. Therein mean:

Fig. 1 shows a photomicrograph in 100 times Enlargement showing typical arrowroot starch granules;

Fig. 2 is an illustration of a microphotograph in 100-fold Magnification of what typical wheat starch grains of primary quality - shows the starch buns with a size within the range of 3 to 40 microns contain;

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3 is an illustration of a photomicrograph, magnified 100 times, showing the concentrated fine grain Shows starch fraction in which most of the particles are less than 12 microns in size;

Figure 4 is an illustration of a photomicrograph, magnified 100 times, showing the coarse wheat starch the invention shows;

Figure 5 is an illustration of a photomicrograph, magnified 100 times, showing the coarse wheat starch shows after heating at 90 ° C. for 40 minutes.

6 is an illustration of a photomicrograph, magnified 100 times, showing a sample of urea formaldehyde shows cross-linked! "of coarse-grained wheat starch after heating to 90 C for ΊΊ minutes;

Figure 7 is a general schematic diagram showing the process steps for dividing the starch products of the present invention;

8 shows a graph in which the particle size distribution of Arrowroot starch and of wheat starch of conventional primary quality and of the coarse-grained special wheat starch according to the invention are compared with one another;
and

Figure 9 is a graph showing the influence of heating on the viscosity of wheat starch slurries from wheat starch of primary quality and fine grain wheat starch and according to the invention

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coarse-grained 'wheat starch is compared with each other.

The most striking feature, which in the accompanying drawings, in particular in Figures 1 and 4, it can be seen that the obtained according to the invention. coarse grain wheat starch very similar in shape and size to the much rarer Arrowroot starch. Indeed, the grainy ones seem Wheat starch particles shown in Figure 4 to be more spherical than arrowroot. If the product be used as a particulate protective coating for coated papers with ink encapsulated in microcapsules .should, makes the spherical granular shape of the obvious large wheat grains make the product particularly effective.

The laid-open Dutch patent application 70 05 04 5 relates to a specially coated paper, the opposite Writing pressure is sensitive to form an image on a second, underlying copy paper. The chromogenic Color capsules are molded onto the back of the paper

* ■

a layer applied, which the original by hand or machine impressed numbers or letters or other Records symbols. When these chromogenic paint capsules break, they release the paint and transfer the image onto the specially treated front surface of the copy paper and an exact copy of the Cover sheet.

This specially treated paper needs a protective material in the coating containing the color enclosed in microcapsules to prevent premature breakage of the pressure-sensitive To prevent capsules during handling. The said Dutch patent application recommends the use of Starch particles, especially from Arrowroot, because the latter

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Has granules with a uniform particle size.

Although examples are given in which corn, wheat and Potato starch is used, but it will be apparent from the entire description that the more effective starch particles Arrowroot particles are. The "other types of starch mentioned are not used commercially. There is a serious one Problem with regard to the production of the pressure-sensitive copier paper described in this patent application because of the global lack of arrowroot strength. The shortage is so critical that already travel to the island areas in the Caribbean Sea, where Arrowroot is growing, to persuade landowners that they can Plant arrowroot for special purposes. Wheat starch, on the other hand, is in a relatively large amount available and can be an economical and readily available replacement for Arrowroot if desired Properties of Arrowroot Strength are met or exceeded.

It has also been tried by others, previously dried Separate wheat starch into a coarse-grained portion and a fine-grained portion by wet processing and using of centrifugal separators. However, these attempts were unsuccessful, apparently because of some effect on the primary quality wheat starch obtained through the drying process was effected.

It has now surprisingly been found that it is possible from an originally native, colloidal wheat starch slurry with a mixed grain size of primary quality, which has not been dried to separate a coarse wheat starch. Such a slurry is

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to a native colloid, which directly from the wheat starch wet ~ grinding process has been obtained before a drying stage. It has also been found that in the cutting process, v / enn if it is to be successful, a feed stream is used which consists of purified native, colloidal wheat starch of primary quality, which as far as possible is free of Salt, fiber and gluten is. This is very important because foreign materials such as salt, fiber and gluten can prevent that the cyclone separator functions in a suitable manner with the formation of a coarse-grained starch fraction.

Another important point for achieving a coarse-grained wheat starch as a full-fledged substitute (match) for Arrowroot strength is that at least two are connected in series Cyclone separators used must be grounded so that the effluent from the first cyclone separator passes through the outlet for the second cyclone separator. The viscosity of the slurry fed into both cyclone separators should be carefully adjusted within narrow limits to ensure that the cyclone separator functions properly. This arrangement has been found to achieve approximately the same percentage concentration of large wheat starch granules, as is normally found in the much rarer Arrowroot starch, has been shown to be required.

Native wheat starch is available in abundance and has a grain size within the broad range from 2 to 35 microns. Most of the grains belong to the upper and lower end of the grain size range, where very few medium-sized granules are present, making wheat starch a natural candidate for separation of starch granules according to their size. It is also possible according to the invention to use rye starch and barley starch in a coarse-grained portion and a fine-grained portion

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separate.

8 of the accompanying drawings is a graphical representation of FIG. weight-based particle size distribution indicated, in which the particle size distribution of a typical wheat starch of Prixaär quality (sample A) with that of a Arrowroot starch (sample B) - and that of one according to the invention coarse grain wheat starch '(sample C) is compared. 7 \ m most noticeable in FIG. 8 is the almost identical particle size distribution the new, coarse-grained one according to the invention Wheat starch sample C with sample B from the extremely rare (scarce) and expensive Arrox-jroot starch.

The significant improvement in particle size distribution in the case of a new coarse-grained wheat starch compared to a typical wheat starch of primary quality according to the invention is easily seen by comparing the curve for sample A with the curve for sample C. Sample A contained only about 21 weight percent starch granules 22 microns or larger in size, while the Sample C contained greater than 55 percent by weight of granules 22 microns or larger in size.

The particle size distribution analyzes were obtained from Use of a Coulter Counter in accordance with the procedure generally set out in the Instruction Manual for Coulter Counter Industrial Model A ". The Coulter Counter and Instruction Manual were provided by Coulter Electronics Industrial Division, 2525 N. Sheffield Avenue, Chicago, Illinois, USA, and this apparatus and operations are located in both U.S. Patents 2,656,508, 2,869,078, 2,985,830, and 3,055,775, and in other publications.

The Coulter Counter is used to determine the number and size of the particles suspended in an electrically conductive liquid,

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by passing the suspension through a small opening with a submerged electrode presses on each side. When a particle passes through the opening, it changes its resistance between the electrodes and generates a voltage pulse of a magnitude proportional to the volume of the particles is. The series of pulses generated in this way is electronically recorded and counted and this data is recorded analyzed, taking the information for the particle size distribution diagrams for each sample shown in assembled form in Figure 8 of the accompanying drawings are to be preserved.

The instruction manual contains special equipment for the Use in conjunction with the Coulter Counter, Model A, listed. For the measurements carried out here, the aperture used 14O microns. There was a reinforcement of Applied 6 times. A two-speed Waring mixer was combined with a semi-micro container (Cerico 17246-2) used with the following facilities:

a) a filter holder (Millipore XXIo o47 oo);

b) filters, 0.45 micron (Millipore HAWP 047 00);

c) electrolytic 80 ml beaker (LaPine 20-81);

d) an air powered stirrer (A.H. Thomas 9224) with a glass stirring rod as a replacement for the electric stirrer;

e) a voltmeter of triplet elec. instrument Company, Bluffton, Ohio, Model 625-NA.

The reagents used consisted of a first reagent consisting of a 2% sodium chloride solution, the 40 g NaCl and 2 ml

37% formaldehyde in a sufficient amount of distilled Water to make up the solution to 2 liters. This first reagent provided the electrolytically conductive medium in to which the observed particles were suspended. In which

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The second reagent used was Triton X-IOO, a wetting agent from Rohm & Haas that uses was used to keep the particles in suspension during the counting of a sample.

To calibrate the device to ensure an accurate count and to accurately identify the starch particles ragweed pollen was used according to its size and it was used according to that set out in the Coulter Counter Instruction Manual specified general calibration procedure worked. The ragwort pollen was used for the calibration because these particles have a perfectly uniform size averaging about 20 microns, which is roughly in the middle of the size range which was to be measured for the preparation of Figure 8 of the drawings. For moistening the ragweed pollen before Isopropanol was used to mix the sample with the electrolyte solution. In the practical counting tests, the Triton X-100 was used used to maintain good dispersion of the starch granules after the sample is first dispersed in the electrolyte. to obtain. The ragwort pollen had to be taken during the Eichurtg handled carefully to account for possible allergy problems.

Procedures for analyzing the Coulter Counter data are in the instruction manual and the raw data can easily be adapted to the computer output program and analysis so that an extremely accurate count of the particles in a particular sample can be performed along with an accurate characterization of those particles by size can.

With the help of the Coulter Counter analysis of according to the invention Process-produced coarse-grained starch samples, it is possible to make a very specific setting of the process parameters to be carried out to achieve "a coarse-grained product with

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consistently good quality. Special strength tests can be carried out with the Coulter Counter and suitable computer programs can be analyzed to determine if the sample has the required number of large particles of a size greater than 22 microns.

The coarsely granular starch product of the invention may further modifications, for example einerVerätherung, esterification, enzymatic hydrolysis and cross-linking, or any combination thereof are subjected to _f. For certain applications where a lower viscosity product is desired, the coarse starch may be oxidized and also modified as indicated if additional changes are desired. A product modified with hydrochloric acid and crosslinked with epichlorohydrin exhibited increased heat resistance and the paste-forming temperature was increased by about 6 ° C.

The coarse grain wheat starch product was obtained with a primary grade wheat starch and that obtained as a by-product fine-grain wheat starch in terms of its viscosity properties compared. The result of this comparison is shown graphically in Figure 9 of the accompanying drawings. Three slurry samples A, B and C were prepared, each based on the dry matter, Contained 8% solids. Each sample was exposed to the same conditions and the respective viscosity behavior during heating, while maintaining at a constant temperature and during cooling within the in the The periods of time indicated in FIG. 9 and at the indicated temperatures and speeds were measured. The native wheat starch of primary grade sample A, which contained a normal mixture of both large and small starch granules increased in viscosity up to about 200 Brabender Units (B.U.) on heating, but the viscosity did not increase

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continued on until cooling started after 60 minutes of testing became. The viscosity of Sample A then increased at a constant rate to a maximum of about 770 B.U. " after about 9 6.5 minutes in the experiment or after about 36.5 minutes Minutes while cooling down. The temperature of the sample had dropped to about 40 ° C. at this point. The fine-grained one Starch of sample D, obtained as a by-product in the method of the invention, was among the same Test conditions show an interesting and somewhat better viscosity behavior. After about 34.5 minutes of heating the viscosity reached a value of about 280 B.U. When the sample is held at 95 ° C for approximately the next 25 minutes the viscosity decreased very gradually to about 225 B.U. from and after cooling, the viscosity of sample D increased very quickly to 655 B.U. after only 15 minutes of cooling. at and thereafter the viscosity steadily increased up to about 1070 B.U. at the end of the cooling period or after 96.5 minutes Test duration. DiQ coarse-grained thickness of sample C, which after according to the method of the invention, behaved very much during the final 20 minutes of cool down similar to sample D. It reached and retained a higher viscosity faster than sample D or sample A a higher viscosity value than sample D or sample A throughout the experiment. After initial heating and after 40 minutes of trial, Sample C already had a viscosity of about 375 B.U. reached and they never fell below this value. During the "hold period" at 95 ° C., the viscosity of sample C slowly increased slightly on 390 B.U. after 60 minutes of the test. As Sample C cooled, a very regular rate of increase began viscosity up to about 1100 B.U. at the end of the experiment.

The comparisons shown in FIG. 9 clearly show a better viscosity behavior not only of the fine-grained one

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erf indungsgeniäßen strength byproduct _r but particularly the coarse-grained product of the invention. An ordinary wheat starch of primary quality, which contained both large and small starch granules in normal quantities and proportions, never achieved a viscosity of more than 800 BU during the tests, while both the fine-grain starch produced according to the invention and the coarse-grain starch produced according to the invention had viscosities of more than 1000 BU reached.

Additional improvements to the coarse grain of the present invention Product can be obtained by further modification of the strength. Figs. 5 and 6 of the enclosed Drawings illustrate a significant improvement made by crosslinking the coarse-grained starch with urea-formaldehyde can be achieved. Fig. 5 shows the effect on the starch granules by heating the product for 40 minutes at 90 C. From this it can be seen that the granules broke and were no longer intact. The one in the The granules shown in FIG. 6, which had been crosslinked with urea-formaldehyde, were intact and homogeneous and white a sharply defined "roundness". The sample shown in Fig. 6 was under identical heating conditions for 40 minutes has been exposed at 90 ° C. From the results of these experiments shown, it can be seen that the respective Modification of the coarse-grained product, which was effected by crosslinking, to a substantial improvement in its heat resistance led, whereby the product in the coating process for the production of carbon-freejKopierbzw. Carbonless paper, which is carried out at elevated temperatures, becomes even more valuable.

The same samples were taken under a Kofler hot plate microscope observed to determine the temperature at which

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100% of the grains lose their birefringence. The samples were also scanned using an amylograph Examined gelatinization point. The gelatinization point temperature recorded was the temperature at which the granules began to become pasty, thereby increasing the Brabender viscosity. The following data was recorded:

large granules

networked large ¹ granule

Kofier heating plate (100% loss of birefringence)

Brabender amylograph

62 ° C

68 ° C

82-85 ° C

(the product became pasty)

no pasty

Due to the low level of urea-formaldehyde used Crosslinking increased the gelatinization point temperature by 6 C as observed in the Kofler hot plate microscope became. The comparison in the amylocfraph was even clearer. the coarse-grained sample that had not been subjected to crosslinking began to settle in at a temperature of 82 to 85 ° C to convert a paste, while in the case of the crosslinked product under the gMchen conditions no paste formation (pasting) occurred.

It is clear that other crosslinking agents such as epichlorohydrin, acetaldehyde, urea-formaldehyde in proportions within the range from 30 to 50 percent by weight urea to 30 to 50 percent by weight formaldehyde, can be used. However, the best results are obtained when using a urea-formaldehyde-water reagent mixture is used in the ratio 29:59:15. This last-mentioned reagent mixture has proven to be "the manufacturing process." proven to be the most adaptable and is

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easiest to use. It is available from E.I.duPont, Inc. under the trade designation UF 85.

The degree of crosslinking was determined by monitoring the alkali fluidity the reaction mixture containing the crosslinking agent and the starch dispersion and by neutralization with Sulfuric acid as soon as an alkali fluidity range of about 49 to 76 ml, measured using a solution of 2.5 g of starch (dry solids content) in 100 ml of solution was regulated. The alkali fluidity preferred according to the invention for a 2.5 g sample is about 59. The reaction was stopped at this point since it was found that this particular degree of crosslinking sufficiently prevents the starch product from forming the crosslinked granules to impart sufficient heat resistance so that they retain their shape at the elevated temperature that during the carbon-free paper coating process is required.

The alkaline fluidity test mentioned above is the most convenient Method of controlling the degree of crosslinking. The test is described in U.S. Patent 3,238,193. The concentration, Tration of the alkali starch dispersion for a special test sample is achieved by adding 90 ml of 0.25 η sodium hydroxide to a slurry of a neutralized, filtered, water washed, moist starch cake containing 2.5 g of des crosslinked starch derivative, based on the dry solids, is determined. The starch sample is taken before the addition of 90 ml of 0.25 η sodium hydroxide slurried in water to to obtain a total of 10 ml of water. After mixing the starch slurry with the sodium hydroxide solution the suspension is stirred for 3 minutes at 45Ο to 46Ο rpm, to convert the starch into a paste. The starch solution obtained is in a fluidity funnel with

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a specific water time between about 30 and 40 seconds poured. The number of ml of starch solution that passed through the funnel within the "water time" (which is defined below will) flow is called the alkaline fluidity of starch. The degree of networking is determined by repeating the above testes monitored at regular intervals with samples taken from the reaction mixture. When the alkaline fluidity test is within the desired range, will the crosslinking reaction stopped.

The one used for the alkali fluidity tests described Fluidity funnel comprises two main parts, e.g. a funnel body and a funnel tip that can be attached to it. An easy Plunger-type conical valve on a glass rod can be used to manually control the flow through the funnel opening. The funnel parts are Made from a stainless steel on a precision machine and polished so that all parts that come with come into contact with the test specimens, have a very smooth surface.

The funnel body defines a generally conical vessel with a 60 ° angle (or 60 ° taper) between opposing, converging funnel walls. The height of the funnel body is sufficient to at least Take a 100 inl sample and attach it to the narrowest part of the The funnel is a 0.699 cm (0.277 inch) opening and fluid passageway for attachment to the funnel tip (Liquid passage) provided. The fluid passage is 3.81 cm (1.5 inches) in length from the opening up to the narrowest end of the funnel body. The opposite wide opening of the funnel body is oriented upwards and the conical valve is from top to bottom inserted into the smaller opening during testing. the

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Actuation of this valve against the "water time" of the funnel provides the test results. At the funnel tip acts it is a bowl-shaped part that can be screwed / grounded onto the narrow end of the funnel body. The inner chamber the funnel tip is hemispherical and 0.495 cm (3/16 inches) in diameter with a lower central opening of 0.178 cm (0.070 inches) which is 0.1247 cm (0.0492 inches) long. The total height for the lower end of the funnel body passage to the lower outer opening of the funnel tip comprises the height the ball chamber (0.25 cm = 0.1008 inches) and the length (0.1247 cm = 0.0492 inches) of the funnel tip opening.

The composite apparatus described above is arranged vertically above a graduated cylinder for the respective tests. At the beginning of each test, the "water time" The apparatus was tested by flowing 100 ml of pure water through the funnel and recording the total elapsed time. The "water time" then becomes

each taken as the time against which ⁷ sample is tested _f .

The flow through the funnel during the "water time" is measured in ml liters and recorded after each test.

each
D. The funnel is washed thoroughly between / test to avoid irregular results. Other starch concentrations than those specified for the tests can also be used. For example, in some cases it may be useful to use a 5 g or 10 g dry substance sample. In these cases 0.37 5 η sodium hydroxide is used. Otherwise the apparatus and method used are the same.

The coarse-grained starch and the cross-linked coarse-grained starch according to the invention both have sub-sieve values which are considerably higher than those of the

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Primary quality wheat starch and the comparable cross-linked primary quality wheat starch, such as the following Table shows.

Table I.

respective strength

coarse grain wheat starch

cross-linked, coarse-grained wheat starch

Primary quality wheat starch

cross-linked wheat starch of primary quality

Sub sieve value (microns) 19.1

20.8 10.8 10.2

A Fisher Sub-Sieve Sizer, model 95, the Fisher Scientific Co., Inc, Instrument Division, Pittsburgh, Pennsylvania, USA, used- When operating after According to the enclosed operating instructions, this instrument provides quick and reproducible measurements of average Particle sizes within the range of 0.2 to 50 microns (Fisher Instruction Manual, Instrument Division, Catalog Number 14-311). Each measurement was taken directly from the curve on the one located on the top half of the instrument Calculator chart read. The air permeability became effective measured and converted into an average particle size based on the principle that air is lighter flows through a bed of coarse-grained powder than through an otherwise equivalent bed of pure powder,

the
which is the same with respect to / shape of the bed, in terms of bulk volume and in terms of the percentage of voids. The measurement of the average particle size was made based on the difference in the general grain size of the material, that is, based on the differences in the average

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Pore diameter and the entire interstitial surface. Although based on complex formulas, it is due to the Standardization conditions from Ernest L. Gooden and Charles M. Smith possible / the average particle size of a The sample can be read directly on the instrument without mathematical calculation (see E.L. Gooden and Charles M. Smith in "Industrial Engineering Chemistry Analytical Edition" 12: 479-482 (1940)).

The coarse-grained and fine-grained ones produced according to the invention Products were made with primary quality wheat starch with regard to their protein content, ash, water soluble Components, compared on a film and fat, the following results being obtained:

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Table II

Analysis of the entire starch sample in weight X, based on the Dry weight

coarse-grained fine-grain wheat starch starch from

Primary quality

protein 0.28 1.11 0.47 ash 0.138 • 0.233 0.221. Water-soluble be
components
(Kohlclrydrat e) 0.00 1.32 1.82 Fibers,
Cellulose fibers
(VJe i ζ onhü 1 s enr este) 0.07 0.1G 0.08 Fats
(only ether extract) '' 0.01 0.17 0.18

The above .Analysenv7erte clearly show that the protein KaIt of primary quality wheat starch mainly on the fine-grained portion decreases. The protein content of the fine-grained fraction is more than twice as high as that of wheat of primary quality, while the protein content of the coarse-grained fraction is only about GO% of that of wheat of primary quality. The ash content of primary quality wheat is more than 1 1/2 times that of the coarse-grained starch product according to the invention.

In this analysis it is particularly noteworthy that detectable, water-soluble carbohydrates in the inventive

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coarse-grained starch product is completely absent. The ether-extracted fat content of the coarse-grain starch was only 0.01% compared to 0.17 and 0.18 % for the fine-grain wheat starch sample and the primary quality wheat starch sample, respectively.

In another comparison, the primary grade wheat starch, coarse grain wheat starch, and fine grain wheat starch Slurried wheat starch and then after the following The specified process is oxidized in order to increase the oxidizing capacity of each of the starch types as a raw material for routine products to compare. The oxidation processes used were as follows:

1) Low pH value: disgrace (7 g) pH 2.5-3.0

Addition of NaOGl ^ concentration ~>

3% (Cl «/ strength")

3-hour oxidation

Neutralization
with

Drying

2) High pH: slurry (5 g)

pH increased to 8.5 with
18% anhydrous soda

Addition of NaOCl
Concentration 2.5% (Cl _o / starch)

3-hour oxidation

Neutralization with
Na ₂ SO ₃

Drying

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With the above samples, viscosity measurements were made using an Ostwald-Fenske Viscometer, Model 200, with a constant agitation speed set at 100-200 rpm. There was a constant temperature water bath of 4OiI ⁰ G used. All reagents and glassware were stabilized at the same temperature. A stopwatch with 0.1 second graduation was used for timing in these tests. A 0.5 η NaOH solution was used to prepare the starch-alkali suspensions to be examined. The following test procedure was used:

1. The six samples to be tested (three with a low pH and three with a high pH) were all weighed first to bring them to 7 g in each sample on a dry weight basis;

2. the sample was then placed in a 250 ml beaker;

3. 10 ml of distilled water were added to the beaker and the mixture was stirred until a completely smooth water-starch paste had been received;

4. The beaker was then placed in the 40 ° C water bath and stirred with the stirrer at a constant speed of 100 to 200 rpm;

5. 90 ml of 0.5 η NaOH were added and the stopwatch was started;

6. The starch-alkali suspension was stirred within a period of 3 to 7 minutes until it was complete was free of lumps;

7. Then 10 ml of the lump-free starch-alkali suspension were added using a 10 ml pipette into the QsbwaH-Fenske

509809/1119

Viscometer transferred;

8. The, sample was placed in the calibrated part of the viscometer wound and held for 9 minutes before timing them from top to bottom Brand flow;

9. The sample was released against the stopwatch and the flow time of the sample was determined.

The viscosity in seconds is the time it took for the sample to flow between the marks. the The results of the tests for the six samples of the oxidized starch were as follows:

Table III

Viscosity in seconds

Sample. '' Low pH value High pH value

Ao wheat starch from primary
quality-oxidized 30th 32 Co-coarse grain wheat starch
oxidized 22nd 20th Do-fine grain wheat starch
oxidized 45 50

This means that 7 g of the dry product is equal to the flow time of 30 seconds under the conditions described for a regular strength

That means 5 g of the dry product is equal to 31 seconds, as indicated.

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From Table III above, it can be seen that there is a difference in effectiveness on the rate of haloxidation duration. The coarse-grained starch product of the present invention (Sample Co) became substantial by oxidation more diluted than primary quality wheat starch (Sample Ao) or the fine grain starch by-product of the invention (Sample Db). The lower viscosity number showed the sample tested had a lower viscosity and the sample Co had the lowest viscosity at pH 2.5 to 3.0 as well as at pH 8.5. Sample Do retained a relatively high level even after oxidation Viscosity at, indicating that the dilution effect of the oxidation process was relatively small, with only a slight change by changing the pH value was established. The grain size obviously has an influence on the rate of halogen oxidation, the coarse-grained Starch (Sample Co) has the best rate. The process for making the coarse-grained starch of the present invention is shown schematically in Fig. 7 of the accompanying drawings. The most important components in the system are are hydrocyclones 1 and 2. In the preferred system the hydrocyclones 1 and 2 are all identical and have the following dimensions:

a) diameter of the cylindrical section 2.60 cm (1.02 inches)

b) Height of the cylindrical section 1.52 cm (19/32 inches)

c) Coating opening diameter 0.475 cm (3/16 inch)

d) Vortex finder diameter 0.803 cm (21/64 inch)

e) Length of the vortex finder inside the cyclone 2.23 cm (7/8 inch)

f) Discharge opening diameter 0.89 cm (0.350 inches)

g) vertex angle 16

509809/1 119

A Doxie Impurity Eliminator, Type P, with those noted above has been used successfully in the system of the present invention Dimensions from Dorr-Oliver, Inc., Stamford, Connecticut / USA, are used. Of course, the dimensions can be in many ways Respect can be changed provided that other compensation stages are performed. For example, if a higher feed pressure is used, slightly larger hydrocyclones can be used. A smaller hydrocyclone works better with a lower feed pressure. It is also possible for the first pass of separation Use Ilydrocyclones of a different size than for the second pass of the separation stage.

To achieve the best results, it has proven to be useful that at least two hydrocyclones 1 and 2 are arranged in series, as shown in Fig. 7, so that the supply line'3 into the loading opening of the hydrocyclone 1 flows under for the introduction of the liquid starch slurry feed of primary quality Pressure into the natural vortex inside of the hydrocycon 1. The preferred feed solids content which gives the best results is about 7.5 Be · The feed for the hydrocyclone 1 must be a native, colloidal wheat starch slurry of primary quality act that is practically fiber and gluten free. As stated above, the system does not work well with reslurried starch granules of primary quality, that have been dried beforehand. Apparently, the hydration capacity changes with the drying process and disturbs the drift effect in the hydrocyclones.

509809/1119

With the native colloidal: wheat starch introduced into the system Finishing of primary quality can be the product of the well-known batter process -Manufacture of wheat starch act. Such a system is on page 58 of the above referenced reference from Whistler et al, Volume II, and in various other publications, for example, in U.S. Patents 2,453,310, 2,504,962, 2,517,149, and 2,537,811. There is many changes to the starch milling process, important conditions affecting the. Feed for the process system according to the invention however, that it is in a native colloidal slurry form is only starch of primary quality and practically free from anything else Material, such as salts, gluten and fibers, is what has the separating effect disturb the I-hydrocyclones. When the feed slurry does not have the desired solids content, it is either concentrated or to the extent required diluted to bring the solid content to about 7.5 Be (corresponding to 13.55% solids, based on the dry weight).

The pump 4 generates a feed pressure of about 11.5 to

2
15.8 kg / cm (150 to 210 psig.). This feed introduction pressure can be increased, a certain improvement in relation to the coarse grain concentration being observed with increasing feed pressure. The presence of suitable equipment, electrical energy costs, and other similar considerations including the desired yield will affect the degree of increase in pump capacity that is believed to be practical.

Through the overflow discharge line 5, the fine-grained

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By-product of the invention in a DeLaval centrifuge 6 transferred, in which it is dewatered. The fine-grained product can then be filtered, and washed in the usual manner to be dried. The fine-grained product contains starch granules, virtually all of which are smaller than 12 microns. The discharge from the discharge line 7 of the hydrocyclone 1 is at a solids content of about 19.0 to 19.6 Be (corresponding to a solids content of 34.31%, based on kept to dry weight). This partially separated slurry is then diluted with water to a solid content of about 7.4 to 7.6 Be (corresponding to a solids content of 13.55%, based on the dry weight) diluted in front of the feed pump 8 for the second slack. The partially separated, dilute slurry is then used as feed material through the feed line 9 for the second passage, into the Hydrocyclone 2

2 pumped. The feed pressure becomes 11.5 to 15.8 kg / cm (150 to 210 psig.) With a feed pressure

2
of about 15.1 kg / cm (200 psig.) is preferred.

The separation or separation process is in the Ifydrocyclonen 2 repeats to form an overflow which flows through the conduits 10 of practically all of the remaining starch granules less than 12 microns in size. The discharge from the hydrocyclones 2 is throttled to the discharge density at about 19.0 to 19.6 Be (corresponding to a solids content of 34.31%, based on the dry weight) keep. This discharge discharge sludge from the hydrocyclones 2 contains the coarse-grained starch product according to the invention, from which practically all small granules are removed

509809/1119

have been. The coarse-grained slurry discharge becomes collected through line 11 and then given a final treatment in the usual way. The final treatment includes the stages of coarse sieving, filtration and drying. The dry cake can be ground in a Jeffrey grinder whiten, whereby care must be taken that a breakage the grain is avoided.

The dried, coarse-grained starch product of the invention appears substantially as shown in Figure 4 of the drawings. As can be seen from this, this exists Product of granules substantially larger than the primary quality starting starch shown in Figure 2 of the drawings. A comparison of FIG. 4 with the figure also shows a very clear difference with regard to the grain size between the fine-grained by-product and the coarse-grained Product of the invention. The coarse grain product was further modified as indicated below.

To crosslink the coarse-grained starch product, a urea-formaldehyde-Uasscr mixture (UF-85) was used with a Part ratio of 29:59:15 used in the order given above. The starch product was first up slurried to a solids content of about 20 to 23 Be and the pH was adjusted with concentrated HGl set to about 2.8 to 3.0. Then it became the UF-85 crosslinking agent was added to the slurry in an amount of about 0.7% by weight and the reaction was carried out at room temperature Allowed to drain for 3 hours. This pH value was then measured with a 14 to 18% by weight solution of water-free

509809/1119

SAD

he set soda to 5.5 to 6.0. The slurry was then diluted to 12-15 Be and dried. The crosslinked coarse-grain starch product prepared as above had higher heat resistance than the comparable coarse-grain product without crosslinking. The crosslinked large granules retained their shape without paste formation even after heating at 90 ° C. for 40 minutes, as shown in Figure 6 of the accompanying drawings. Because of this additional heat resistance, the crosslinked product is useful in additional copy paper coating processes that employ higher temperatures which destroy the unmodified starch granules.

A combination of the crosslinking process described above with the oxidation process described above has proven to be particularly suitable for improving the properties of the coarse-grained starch according to the invention the effects achievable by each modification have also been proven. The oxidized crosslinked product was generally manufactured as follows:

(a) (b) (c)

Coarse-grained ■ ■■ 2-hour ■■ 3-hour Setting wheat starch oxidation crosslinking on a slurry in acidic conditions below pH of

pH value of turn of 5.5 with 3 under UF-85 (1.6 ^Na ₂ ^C0 3 turn of wt .-%, be-0.04% NaOCl added (Cl ₂ / starch) the dry weight)

After crosslinking, the product was filtered, washed and washed

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dried. For comparison, the oxidized, cross-linked, roughly

with
granular product / Arrowroot starch, the coarse-grained unmodified product and the coarse-grained oxidized product described above, for example the sample Co, experiments were carried out to produce carbon-free insulating paper and copy paper. The samples were used to coat the copy paper by a process in which the starch particles were continuously heated to about 66 C (150 F) for about 2 hours. The respective samples were then examined for their "smear values" , in which the degree of protective effect during handling was visually observed, which was imparted to the color particles encapsulated in microcapsules in the paper coating by the starch particles. The oxidized, crosslinked, coarse-grained product described above worked satisfactorily in these comparative tests, as / well as Arrowroot and was an ideal substitute for it.

The novel, coarse grain starch product according to the invention, the fine grain corn starch by-product and the modified coarse grain starch product of the invention are each suitable for a wide variety of special applications in which corn starch was previously considered not considered useful., By the present invention is it possible to use a grain starch that is available in large quantities, such as wheat starch, barley starch, or rye starch, as a replacement for dfe seh? rare and expensive arrowroot starch, especially in the fields of application such. B.

509809/1119

for lithographic anti-offset powder and carbon-free copier or. _{Use carbonless paper t} where the grain shape and size are important.

Wheat, barley and igloo starches have a natural distribution of larger grains, the size of which is within the • Range above 30 microns, and small granules below 10 microns, with few granules having have a medium size. The large granules of these special native corn starches are uniform in shape round and resemble arrowroot starch granules in size and appearance. The annual Uelt production these cereal grains from which these starches are made is approximately:

Wheat - 400 · 10 ⁹ I (11.342 · 10 ⁹ bushels) (1970) Barley - 180 · 10 ⁹ I (5.038 · 1O ⁹ busheis) (1970) Rye - 53 · 10 ⁹ I (1.5 · 1O ⁹ busheis) (1966)

Arrowroot is rare and much more expensive than the starches given above, so the product and the invention Method provides an inexpensive and widely available substitute for Arrowroot starch. Essential The feature of the present invention is that it has been found that the separation process using Ilydrocyclonen with a native, colloidal starch slurry of primary quality Must be carried out as far as possible by others

Free substances such as salts, fibers and gluten, / is and after the meal method has not been dried. It has also been found that especially when processing wheat starch is, the separation process by a first hydrocyclone and

509809/1119

a second hydrocyclone using the partially separated Effluent from the first hydrocyclone should be carried out as feed material for the second hydrocyclone.

Hydrocyclones are careful about all dimensions selected and- have no moving parts. The separation is a function of the solids content (the density) of the feedstock introduced into the hydrocyclones, the feed pressure and the throttling equilibrium between Overflow and drain. The most appropriate size separation gives a product which is at least 55% by weight smaller

Granules greater than 22 microns in size. The solids content of the feed to the hydrocyclones of the first and second pass should be at about 7.5 Be be maintained and the fluid pressure in the loading

2 delivery line should be around 13.0 to 15.8 kg / cm (170 to 210 psig.).

The process according to the invention gives a coarse-grained one Product that has the following particle sizes when compared to Arrowroot:

Table IV

Coarse grain wheat starch
Weight % size

arrowroot
Wt% size

25 28 microns and larger 50 24 microns and larger 75 20 microns and larger

25 30 microns and larger 50 26 microns and larger 75 23 microns and larger

509809/1119

Although the invention has been explained in more detail above with reference to specific embodiments, it is it is clear to the person skilled in the art that this can be changed and modified in many ways without this the scope of the present invention is departed from.

509809/1 1 19

Claims (32)

Claims 1. Improved coarse grain starch product from the group of wheat, barley and rye starch, thereby characterized in that the starch is essentially free of other substances and that at least about 22% of the total number of the granules are at least 22 microns in size; and at least about 99% by weight of the granules are in size be at least 12 microns. That at least 55 percent by 2. Product according to claim 1, characterized -.% Of the granules have a size of more than 22 microns. 3. Product according to claim 1, characterized in that the starch uiii is a wheat starch of primary quality acts as it is in a continuous wet milling process for the production of a native, colloidal starch slurry which is subjected to hydrosyclone separation in the state of native colloidal slurry has been. 4. Product according to claim 5, characterized in that the starch granules to improve their V / heat resistance have been subjected to networking. 5. Product according to claim 4, characterized in that the starch granules have been crosslinked with urea-formaldehyde are. 6. Product according to claim 5 »characterized in that the granules remain intact after heating at a temperature of 90 ° C for about 40 minutes. 7. Product according to claim 5 »characterized in that 509809/1119 the starch granules have also been oxidized. 8. Product according to claim 7 »characterized in that the starch granules have been oxidized with sodium hypochlorite. 9. Product according to claim 7 »characterized in that the gelatinization temperature of the starch granules, which expresses itself in a loss of birefringence when observed under a Kof ler hot plate microscope, is approximately 6 ° C higher than the gelatinization temperature of the unmodified coarse-grained ones Wheat starch. 10. Product according to claim 9 »characterized in that the temperature at which the loss of birefringence occurs in the oxidized, crosslinked product, etv / a 68 ⁰ C · 11. Product according to claim 1, characterized in that the starch granules have been modified by acid. 12. Product according to claim 1, characterized in that the starch has been subjected to crosslinking with epichlorohydrin to improve the heat resistance of the 'starch granules. 13. Product according to claim 12, characterized in that the starch is also oxidized. 14. Improved coarse grain bark product from the group of wheat, barley and egg starch, characterized in that the starch consists of at least 22% granules which have a size of 22 microns or more and that they are oxidized with sodium hypochlorite and Crosslinking with urea-formaldehyde has been further modified so that ^509809/1119 a 2.5 g sample of the starch has an alkaline fluidity of about 49 to 69. 15. Product according to claim 14, characterized in that that "the starch is wheat starch and that the product has a gelatinization temperature that is about 6 C higher than that of a comparable sample from the unmodified coarse-grained wheat starch, from which it is derived. 16. Improved coarse grain starch product from the group of wheat, barley and rye starch, characterized in that the starch consists of at least 99 wt. ~ / £ of granules with a size of at least 12 microns, that it is practically free of water-soluble carbohydrates and contains less than about 0.01 % Xther extractable fats. 17. The product of claim 16 characterized in that at least about 22 % of the total number of starch granules are 22 microns or greater in size. 18. «Product according to claim 17, characterized in that it is crosslinked with urea-formaldehyde or epichlorohydrin has been further modified. 19 · Product after. Claim 17 »characterized in that it has been oxidized. 20. Product according to claim 17 »characterized in that it up to a certain degree of oxidation and crosslinking to increase the gelatinization temperature of the product about 6 C compared to the gelatinization temperature of the unmodified Coarse-grained starch is oxidized with sodium hypochlorite and with urea-formaldehyde or epichlorohydrin has been networked. 509809/1119 21. A method for producing an improved coarse grain starch from the group of wheat, barley and rye starch, characterized in that a native, colloidal slurry of the starch selected in each case is subjected to a hydrocyclone separation in a first hydrocyclone, the partially separated coarse-grained effluent slurry from "collects it from the first hydrocyclone, subjects it to a hydrocyclone separation in a second hydrocyclone and collects the coarse-grained drainage from the second hydrocyclone to form a coarse-grain cereal starch that is practically free of substances other than starch and in which at least 22 % of the grains have a .Have a size of 22 microns 22. The method according to claim 21, characterized in that that corn starch is used as starch which has been produced by the continuous milling process, and that the slurry introduced into the first and second hydrocyclones at a concentration of about 7.5 ° Be held. 23 «Method according to claim 22, characterized in that .that the first and second 'hydrocyclone used such be that in. essentially have the following dimensions: a) a diameter in the cylindrical section 2.60 cm (1.02 inches) b) a height in the cylindrical section of 1.52 cm (19/32 inch) c) a diameter of the loading opening from . 0,475 cm (3/16 inch) d) a vortex finder diameter of 0.803 cm (21/64 inch) e) a vortex finder length inside the hydro 7/8 inch (2.23 cm) cyclones f) a diameter of the discharge opening of 0.89 cm (0.350 inches} g) a vertex angle of 16. 509809/1119 24. The method according to claim 21, characterized in that the native, colloidal slurry is a slurry of primary quality wheat starch that is practically free from salts, fibers, gluten and all foreign substances is. 25 · The method according to claim 23, characterized in that that the hydraulic pressure for feeding the first and second hydro cyclone is within the range from about 11.5 "to 15.8 kg / cm (150 to 210 psig) is held. 26. The method according to claim 25 *, characterized in that that the pressure to feed the first hydrocyclone maintained at a value of about 15.1 kg / cm (200 psig) will. 27 · The method according to claim 23, characterized in that the partially separate process from the first * ■ Hydrocyclone diluted with water to form a partially separated slurry which is introduced into the second hydrocyclone at a concentration of about 7.5 ° Be and a solids content, on a dry weight basis, of about ^{13.55 c} / ° . 28. The method according to claim 21, characterized in that that the fine-grain starch overflow from the first and ZT / eiten hydrocyclone collects. 29. Use of the product according to claim 1 as a protective particle in a surface coated with breakable microcapsules to prevent premature breakage the same during handling. 30. Use of the product according to claim 6 as a protective 509809/1119 original inspected tiKel in a coated with breakable microcapsules Surface to prevent premature breakage of the same during handling. 31. Use of the product according to claim 9 as protective particles in a surface coated with breakable microcapsules to "prevent their premature breakage during handling. 32. Use of the product according to claim 14 as a Schutaparticle in a surface coated with breakable microcapsules to prevent them from breaking prematurely during handling. 33 · Use of the product according to claim 20 as a protective particle in a surface coated with breakable microcapsules to prevent them from breaking prematurely during handling. 509809/1119 Blank page