Патент USA US2131724код для вставки
_ Patented Oct.‘ 4, 1938.. 2,131,724. " UNITED, STATES ‘PATENT OFFICE George Stein,V. Hall Caesar, & Company, New York,'N. Inc., New Y., York, assi'gnor N. Y.,' a corporation of New York - ~ Application August 2c, 1936, No I Serial No. 98,071 12 Claims. (01. 12-1-33)‘ polysaccharides, and to a new and improved tion with oxidizing agents, such as barium per oxide, in the treatment of starch. This treat ment preferably involves the blending’ of a dry method of converting starchy polysaccharides. glue base by mixing together a starch, urea, an ' This invention relates to new and useful com positions of matter obtainable‘ from starchy 5 A number of processes are known for the con version or degeneration of starch into so-called ' soluble forms,,such as dextrins, thin-boiling and , soluble starches. According to most of _ these oxidizing agent, and a ?ller, and the‘treatment .5 of this glue base with water and a caustic alkali by the‘ user. No claims are advanced with re ‘spect to degenerated starches, such as dextrins, -‘ methods starch is treated either in the dry form ' etc., and the starch in the dry blend, as marketed, 10 or in aqueous suspension with'an acid or with an. ' is wholly unaltered. Furthermore, the prepara- 10 __ oxidizing agent,’ and variously heated. The term tion of the glue by the user involves the use of "conversion” generally‘refers to dry treatments. 'an alkali, and in this respect is analogous to Various processes have also been proposed which other methods of treating starch with an alkali. It is an object of the present invention to pro involve heating (starchwith a strongly alkaline 15 substance in'one form or another to produce duce a new and improved amylaceous composi- 15 . , products of a higher order of viscosity than ob tained by roasting with or without pretreat ments with aqueous acid. _ tion of new and useful properties, .A further ob- . ject is to produce an amylaceoiis composition of British gum,‘ soluble in water, at relatively low. ' . In the various methods of treating starch, urea 20 has been mentioned as an auxiliary gelatinizing. agent, or as a substance adapted to lower the temperatures, in the sense that it readily dis perses in the water, but unlike an ordinary dex-‘ 20 trin or British gum of similar 'dispersibility, has a a body or viscosity in its liquid suspension which a gelatinized material. Thus, Hoppler et al., _ is relatively very high, its consistency being more U. S. Patent No.‘ 1,878,852, produces swelling analogous to that of an unconverted starch than 25 starches by heating thin layers of starch con that of a' “British gum” dextrin. Anotherv ob- 25 v taining, the normal proportions of water for a -ject is to produce a dry material which dis short period'between two faces of any desired perses in water- and behaves generally in a man form, at temperatures above 100° C., and simul ner similar to natural. gums, such as, ‘for ex taneously applying to the same mechanical pres ample, gum karaya and gum shiraz. vA further 30 sure of about 2500 kg./cm.2. The use of urea as object is to produce anew and improved com- 30 a substance adapted to lower the temperature at position which has a wide variety of uses, and especially in the ?eld of natural gums, textilev which starch is converted into starch glue is in cidentally mentioned, but no proportions are color=printing vpastes, as- an adhesive, as a given and it is apparent that the method de thickener or carrier for other gums, and in im-_ 35 scribed involves principally three factors, name-t, pregnating, coating and sizing ?brous sheet ma- 35 1y, pressure, heat, and duration of the heat terials, for example, paper, cloth and the like. treatment. It produces primarily a gelatinized' A still further object is theprovision of a new and improved process for producing compositions » vstarch in which the original granular organiza tion is destroyed, asin the various hot-rolled of the‘character above described. Other objects _ . temperature at which starch is converted into ' 40 starches. ' Bauer, U. S. Patent No. 1,969,347, relates to the treatment of flour by_ adding thereto a gel in hibiting agent, preferably a sulphite salt, and then converting the starch present. The gel '45 inhibiting agent reacts with the small amount of ' gluten or other protein substance present in > the flour, and thereby prevents the formation of \a dough. As pointed ‘out by. the patentee, ren dering the gluten or otherprotein inert is desir 50 able because these substances interfere with the ‘ proper conversion of the starch. In this process, urea‘ is mentioned as a: suitable gel inhibiting will appear hereinafter. ' a 40 In accordance with this invention I have found ‘that a new and useful composition of matter which is dispersible in water. at moderate tem peratures, may be obtained by the conversion of a starchy polysaccharide with a suitable amide, 45 such as carbamide, commonly known as urea. In‘practicin‘g the invention I prefer to heat the starch in its natural air-dry condition to ya temperatureat which .all, or nearly all, ofthe‘ original moisture present has been removed, then 50 to add urea and continue the heating. »In this manner a conversion of the starch occurs, bu't‘the normal degeneration or hydrolytic scission, char agent or reactant to render theproteins inert.‘ Pierson, U. 8. Patents Nos. 1,989,150 and . acteristic of ~other types of conversion, is shown by chemical tests to be reduced. The granules gy. - - 55 2,023,973, describes the “use of urea in ‘conjunc 2 ' 2,131,724 of the converted product retain their original Placed in a suitable converter and heated. At a . form, but may have undergone an incipient proc temperature of 115° C., 408 grams of carbamide (urea) were added and the conversion ‘carried to 205° C. over a total period of three hours and ?fty-minutes, with results resembling Example I. 5 Example III es of structural_ reorganization promoting swell . ing or hydration in aqueous suspension. The 6 resultant gum will disperse to an exceptionally heavy body in water at relatively low tempera tures, with little or none of the normal granular - disorganization which is so characteristic of the , various so-called dextrin solutions. l0 The term "soluble" as applied to starch and dextrins is somewhat misleading, because a starch or‘ dextrin properly possesses no true solubility, but only a varying degree of dispersion in aque ous suspension. The composition of my inven 15 tion is “soluble” in the sense that it readily dis perses in water to give a transparent or translu cent dispersion; but unlike an ordinary dextrin of similar dispersibility, the body or viscosity of its liquid suspension is relatively high, its consis ' 2'0 tency,being more analogous to that of an un converted starch than that of a dextrin. In this respect my product-resembles a British gum or roasted dextrin having a viscosity of the order of a starch. Unlike many of the so-called soluble ; g5 starches, however, it will disperse in aqueous sus pension at relatively low temperatures and‘ its liquid paste will not vary greatly in consistency from hot to cold; nor will the body of its paste, upon long standing, ,tend appreciably to set to an 30 immobile gel, as is generally true of the starchier pastes. The extraordinary stability of the liquid gum produced by this polysaccharide composi tion constitutes one of its most remarkable and useful properties. 35 - _ The invention will be further illustrated, but is not limited, by the following examples, in which the quantities are stated in parts by weight, un less otherwise indicated: Example I .40 Eighteen (18) pounds of tapioca ?our were placed in a suitable converter and heated. At a temperature of 132° C., 408- grams of carbamide (urea) were added and the conversion carried to a temperature of 193° C. over'a total period of 45 four hours. ' ' The product wasremoved from the converter and found to be readily hydrated in cool water to produce a dispersion of relatively high viscos ity which did not very markedly tend to increase in consistency, upon standing, nor after having been cooked and cooled. This product was sub "\-.\_ stantially free from urea. Comparative tests showed that it possessed markedly di?’erent prop . Example I was repeated with sago ?our instead of tapioca ?our, the proportions and conditions .being the same otherwise. Similar results were 10 obtained. _ ' ' Similarly, the invention is’ applicable to the treatment of other starchy polysaccharides. As further examples of specific carbohydrates may - be mentioned wheat, rye, barley, oat, rice, maize 15 and potato starches, and sago and cassava ?ours. In general, especially good results have been ob tained with’starches and ?ours substantially free from proteins. . r > - - ‘ ' . The amount of moisture initially ‘present in, 20 the starchy polysaccharide'may vary within rel atively widelimits. ' Good results have been ob tained by using starch in its normal air-dry con dition, e. g.; containing approximately 10% to 20% moisture. However, if desired, pre-mois- 2,;. v tened starch maybe used, for example, starch ' containing more than about 20% of moisture but insu?icient amounts to cause gelatinization upon heating. If desired, the starchy material may be given a_preliminary spraying treatment with an 30 acid after the normal fashion, to be followed later by the addition of urea, to obtain results inter mediate between normal products and' those ' which are typical of straight urea conversions. ‘ The amount of‘ urea is subject to variation, depending particularly upon the type of material 35 treated and the results desired. In general, it is preferable to employ about 2% to 5% of urea on the basis of the natural air-dry weight of the starch. “However, more or somewhat less urea 40 may be employed. The temperature of conversion may vary with in relatively wide limits. Thus, the temperature at which active conversion takes place may vary within the range of about 130° C. to about 200° C. Normally, good results are obtained by carry ing out the reaction at temperatures below 200° C. The'time of heating may vary, depending upon such factors as‘ the raw material treated and the‘ results desired. - ‘ v The process may be carried out at atmospheric 5° pressure. However, lower or higher pressures may be used if desired. The urea may be added to the starchy poly erties ~from ground tapioca, hot-rolled tapioca,' saccharide before the. starch has been subjected and the usual type of soluble roasted dextrin to heat, that is, at the beginning of the conver '(British gum). In ‘the dry powdered state, it, sion. Addition of' the urea at an intermediate had a creamy. or light ‘brown color. It readily stage of the conversion tends to reduce the dispersed in water without heating to give a; amount of tailings. , _ homogeneous translucent gum resembling a nat~ ' '0 ural gum. Its dispersions, e.g., one part of solid to 8-8 parts of water, were much more viscous thanthe dispersions made with the same amount . of the ordinarysoluble roasted dextrin (British While‘ the invention is not limited to any 60 theory, it is believed that the useful results ob tainable by the presence of urea in the treatment of a starchy polysaccharide as herein described may beeexplained on the following basis: Urea gum). As compared with hot-rolled starch dis melts and decomposes under ordinary pressures '5 persions, it also showed a much higher viscosity .'-at a temperature between 130° Grand 160° C. to at high temperaturs, and a diil'erent consistency ammonia, ammonium cyanate, and ‘biuret, the ,at all temperatures, for the same amount dis cyanate subliming. Between 160° and 190° C. in ~ ' persed. Its disperslons'we're short and soft, not stringy and sticky’ like the hot-rolled ‘starch dis " persions. Moreover, it gave no substantial gran ' 11hr ‘disorganization as in the case of hot-rolled -‘. ?tarohesand ordinaryBritish gums.) -- to eighteen (18) Example 11 ' _ pounds .of tapioca ?our were creasing amounts'of biuret, as well as cyanuric acid and ammelide are formed; above 190° C_. 70 the biuret decomposes, yielding cyanuric acid, ammelide, and tricyanourea. Above 200° C.'urea is said to decompose to ammonia, cyanuric acid, tricyanourea, ‘and ammelide; but for the major ity of dextrin conversions the process will termi- .15 3 arenas nate at not to exceed 200° C. Practically speak sures until a product dispersible in water at ing, the normal conversion range will vary some ordinary temperatures is obtained. _ ' what between a minimum temperature su?icient 3. The process which consists in heating a nor 'for conversion and the ‘temperature at which substantial charring occurs. In the conversion representative of my process, the starch granules may become coated with melted urea; and so the mally air-dry starchy polysaccha'ride' to a tem - ammonia, which is given on abundantly, is gen composition point of urea under substantially. ~ ~ perature su?icient to remove most of the moisture present therein, adding urea'and heating the re sultant mixture to a temperature above the de atmospheric pressures until a conversion product erated directly on the granules-“In situ” as it dispersible in water at ordinary temperatures is 10 10 were-in a manner most effective to prevent active hydrolysis with consequent scission or de-' formed. generation, an effect invariably accompanied by great loss in the body. or consistency of the sub sequently formed liquid gum. It is this release , w . .4. The process which ; consists .in heating starch in the air-dry state to a temperature of about 130° C. without destroying the starch struc 15 of ammonia gas intimately throughout the mass ture, then adding about 2% to about 5% urea, .15 of the charge which may account for the unusual - ‘and continuing the heating to a temperature at e?fect of ureajn preventing structural degenera which the urea melts and materially decomposes and a starch conversion product is formed which tion and loss of viscosity or body. As a further explanation it is believed that the has substantially the original granular structure 20 molten urea may induce an incipient swelling or - of the starch and disperses in water at ordinary temperatures without substantial granular dis enlargement of the granule with consequent structural dispersion which should conceivably promote subsequent hydration and so account organization. , 20" ' 5. The process which consists in heating for the useful property of easy and rapid disper- _ starch with urea under substantially dry condi 25 sion possessed by compositions of my invention tions and under substantially atmospheric 'pres ~25 -' ' in water at relatively low temperatures. sure at a temperature above the decomposition The composition of my invention is conmier point of urea, but below about 200° C. until a con version product dispersible in water at ordinary ciallyuseful in: (1) The field of so-called natural gums, e. g., gum shiraz, and the like; -(2‘) for temperatures is formed. v . 6. A cold water-dispersible starchy polysac 30v 30 textile color-printing gums and pastes; (3) as an adhesive, and.v particularly in the ?eld of paper - charide conversion product which is a reaction adhesives; (4) as a thickener or carrier for other product of a starchy polysaccharide with urea, products, e. g.,>_ful1er’s earth, bentonite, starch, _ at a temperature at least as high as the decom starchmixtures with formaldehyde, caustic al-, position point of urea in the presence of insuf kalis, and/or borax; (5) as a paper beater size for certain types of paper and paper board; and iicient moisture and under pressure and tempera- . 35 tureconditions insu?lciently high to destroy the (6) generally, inimpregnatlng, sizing, coating,_ original starch structure. '7. A cold water-dispersible starch conversion ?lling and gluing ?brous sheet materials, for ex- 7 _ ample, paper, paper board, cloth, and‘ similar product which is a product‘ of the reaction in a materials. , substantially dry state of a starch with urea, at It will be understood that auxiliary agents may a temperature at least as high as the decomposi be added to my compositions for various pur'_ . tion point of the urea but under temperature and poses. Thus, I-may add oxidizing and reducing pressure conditions insu?iciently high to destroy agents, e. g., sodium perborate, sodium bisul?te, the original starch structure. ' . 45 sodium hydrosul?te, sodium formaldehyde sulf oxalate, and similarcompounds. 8. A process of producing ‘a cold water-dis _persible starch conversion product which com-i ‘ prises heating tapioca ?our containing insuf ?cient ‘moisture for gelatinization in the presence The advantages of the invention will be sip--v parent. I have found that by heating a starchy polysaccharide with urea in su?icient amounts 50 at temperatures above its melting and decom posing point, it is possible to produce an amy laceous substance dispersible in- water at relatively of urea under'substantially dry conditions at a temperature within the range of about 130° C. to about 200° 0., and under pressure conditions in su?iciently high to destroy the starch structure low temperatures and having other new and use until a conversion product is. formed which dis ful characteristics: Furthermore, it is possible perses in water at ordinary temperatures and 55 to convert the starohypolysaccharide with urea ' pressures. > by-my process without the necessity for high ,9. A conversion product of a starchy. poly pressures. Additionally, my product di?'ers gen saccharide with urea which po substantial erally from the products obtained by the proc- ’ ly the "structure of the starchy polysaccharide esses heretotore’described in that it is essentially in the dry state and will disperse in water at a type of polysaccharide product commercially ordinary‘ temperatures taking up at ‘least six known as a British gum, formed by roasting, but ., parts of water per part oi’ conversion product having special physical and chemical properties, without substantial granular disorganization to as previously noted. - '- . p - ~ s produce ‘dispersions which will not vary greatly v . Having thus described the invention, what I_ in consistency with variations in temperature. .10. A tapioca ?our-urea. conversion'product claim asnew and desire to by Letters ,1. The process-which consists in heating a starchy polysaccharide with urea at a tempera; 'which resembles a natural gum in many ofj'its properties and possesses substantially the struc ture of the natural tapioca ?our in the dry state, ture of at. least the melting point otnurea in a 70 substantially dry‘state 'under substantially ‘at and which will disperse in six to eight parts of water per part of conversion product at ordinary Patent of the United-States is: . ' < . . 70' mospheric pressures until a product‘ dispersible vtemperatures without substantial granular dis in water at ordinary temperatures is obtained. organization to produce viscous ‘dispersions 2. The process which consists in reacting to; which will not vary greatly in consistency with , gether starch and molten urea in a' substantially dry state under. substantially atmospheric pres variations in temperature. , I, - ll. A-method of producing a cold water-dis 16 4- . . ' 2,131,724 persible starch conversion product which com prises heating a starchy polysaccharide contain ing insu?icient moisture for gelatinization with urea under substantially dry conditions at‘ tem peratures within the range of about 130° C.,to about 200° C. and under substantially atmos pheric pressures until a conversion product is formed which disperses in water at ordinary _ temperatures and pressures. 10 ‘ prises heating a starchy poiysaccharide which is substantially free from proteins and containing insu?icient moisture for gelatinization in the presence of urea under substantially dry condi tions at a temperature within the range of about 130° C. to about 200° C. and at pressures not sub stantiaily higher than atmospheric until a con version product is formed which disperses in water at ordinary temperatures and pressures. ' ' 12. A method of producing cold water-dis persible starch conversion products which com GEORGE vv. CAESAR.