CA1233827A - Halogenated hydantoins - Google Patents

Abstract

HALOGENATED HYDANTOINS

ABSTRACT

A halogenated hydantoin product end method of producing same for use as e.g. a bleaching agent or disinfectant comprising a halogenated hydantoin of the formula

Description

HALOGENArED H_D NTO NS

3BI~CI~GROUND Ol~ THE IN~EN~IC)N
_ The plesent invention relates to hslogenated hydantoin pro-ducts whieh may be used to produce low dust powders, granules, 5 briquettes, tablets, and other forms by mechanical eompaction, and casting from a melt. The present halogenated products also may be in the form of castings, flak~s and produrts made by treating inert carriers with the halogenated hydantoins in ~ melt condition. More specifically, the present invention relates to halogenated ethylhydantoins (hereinafter 10 referred to as "HEH") either as sole constituent or in admixture with a halogenated dimethylhydantoin (hereinafter referred to as "halo I)MX") so as to produce the product forms enumerated above. As used herein, "HEH" or halogenated ethylhydantoin refers to compounds of the formula 15 1 ~O
R - f c Xl - N N
\~ / \X2 20 wherein R is methyl or ethyl and Xl and X2 which may be the same or different are chlorine or bromine. The present in~ention ~Iso eontem-plates utilizing the HEH in admixture with hhlo DMH, an active chlorine ~ompound and/or an inert carrier in an amount sufficient to produce the desired end product, e.g. powders, granules, flakes, compacted forms, cast 25 forms, etc.
A distinct need presently exists in bleaching, dishwashing, toilet bowl disinfection and water trealment applications (e.g. cooling water treatment, spa and swimming pool disinfection) for halogenated hydantoins in the form of dust-free powders, granules and shaped forms of 30 high integrity. ~s used herein, the term l'high integrity" is mean$ to refer to soiled products having a predetermined shape ~e.g. tablets, granules, ~1. ~ 3; 3 ~

nak~, briquettes or the like) ~hich are hard, ~hspe retentive structures hich, for all intents and purposes, ~re dust-free. A need for wch dust-free forms of halogenated hyd~ntoir~ exists p~rtieularly In light of enYironment~l and safety eon6iderations. Halogen donor compounds ~re S {rritating in nature. If such products exhibit a l~rge Æmount of dusting, they are undesirable for use in the home ~s well as in industrial environ-ments, e.g. ~or bleaching or dishw~shing purposes. Additionhlly~ a high dusting product tends to intensify the halogen ~dor normally asso~iated ~rith halogen donor comp~ds. Such ~ halogen odor can, in Qnd of iSelf, 10 be most irrit~ting, and should be avoided.
H~logenated derivdtives of dimethylhyd~ntoin (e.g. 1,3-dibrom o-5,5-dim ethylhyd~ntoin; l~rom o-3-chloro 5,5-di m ethylhydantoin and 1,3~ichloro-5,5-dimethylhydantoin) are halogen Jonors typic~lly utilized for various purposes. Thus, l-brom~3-chloro-5,5~imethylhyd~n-15 toin used fo~ swimming pool ~nitizers, wllile 1,3-dichlor~5,5-dimethylhydantoin has been used successfully for bleaching (see, Kirk-Othmer, Encyclopedi~ of Chemical Technology, Volume 12, pp. 704-705, Wiley Interscience (1980); and US. Pstent No. 2,779,764 to Patterson).
However, such halogenated derivatives of dimethylhydantoin are fine, 20 dusty powde~ which are difficult to compact into solid forms of high integrity or to granulate. Compaction of 1,3-dichloro-5,5-dimethyl-hydantoin has been proposed in 1~5. Patent No. 4,242,216 Daugherty et al. In practice, however, it has been found that compaction of 1,3-dichloro-5,5-25 dimethylhydantnin without binders or Qdditives fails to produce solidforms of high integrity which are commercislly desir~ble and alleviate the dusting problems normal!y attributable to such solid, physically unst~ble forms thereof.
Typically, when it is desired to produce commerci~lly acce~
30 tsble forms of a halogen~ted dimethylhydantoin, a Mnder of certain poly-valent metallic caticns, for examp~e, those of sluminum, zinc, tin, iron, chromium, magnesium ~nd silicon, is utilized to "cement" the halo DMH
into a useable form ~see, e.g. I~S. Patent No. 3,412,021 to P~tterson).
However, use Or such binders necessarily increases U~e cost of the hsl~
35 gen~ted hydantoin product, ~hich eost is passed onto the ultimste con-.

~0, ......

sumer. Moreover, such "~inders" do not ~lleviate th~ dust problem to thedegree now realized by the present invention nor provide durable forms or shapes without the use of sdditives by simple compaction in the dry state.
Problems also exist when ~ttempting to produce solid halo 5 DMH products blended with other materials by high temperature snd melt techniques. Such techniques are not feasible with halo DhlH due to the high melting ranges of the materials which are relatively close to the decomposition temperatures of the materiRls as noted in Table 1 below.

T~ble 1 10 ll~eltin~ Point snd Decompo6~ffon Properties ~alogenated DM~

l~elffngDecompadtion Raslge CTemperature oCa 1. 1,3-Dibrom~5,5-dimethylhydantoin 177-184 186b

2. 1-Brom~3-chloro-5,5-dimethylhydantoin 158-165 160C

aInitiation of an exothermic decomposition when a 3 grsm sample is placed in a test tube immersed in ~n oil bath and heated at a rate of 2 0 1-3 C/min.
bvapor forms at 160C
Cvapor forms at 156C

Thus, the narrow temperature rsnge between melting and decomposition of hQlo DMH derivatives renders such compounds unsuitable for producing 25 commercially scceptable products utilizing techniques involving high temperatures.
Accordingly, it is a primary object of the present invention to provide a method of producing halogen donsting hydantoin compounds in the form of low dusting powders ur granules, thereby minimizing the 30 irritation normslly sssociated l~nth active hfilogen compounds.
;

~3;~

~t i~ yet a further object of the present lnvention to provide hslogennted hydnntoins r hieh cnn sasily be handled ~y the cor~umer, both industrisl Rnd domestic, ~ith llttle or no risk of eye, ~kin and ~espiratory irritation.
Still yet another ob3ect of the present invention i~ to provide halogenated hydantoins ~vhich c~n readily and e~sily be ~h~ped ~nto a solid product forsT having high integrity.
These ~nd other advantegeous Aspects Or the present inven-ffon will become more cle~r to the redder after c~reful consideration is given the description thereof which follows together with the sccomp~ny-ing examples.

SUMMARY OF THE INVENTION

In accord~nce with the pFesent invention there is provided a novel method for producing low-dusting powder, granular &nd ~h~ped forms (e.g. t~lblets, briquettes or the like) of halogen~ted hydantoins. The unexpected results of the present invention ~re re~lized utilizing the desireble properties of halogenated ethyl hydantoins having tl~e formul~

~12E~5 C~

wherein R ~ methyl or ethyl ~nd Xl and X2 which msy be the same or different are chlorine or bromine (sometimes referred to ~s HEH herein).
The present invenffon contemplstes a method for the production of 8 rree-flowing, non~usting halogen~ted hydantoin prs>duct which comprises halogenRffng under ot~ntrolled (i.e. m~intaining relstively constant) pH
conditions of from 6.0 to ~Ibout 8.0 (preferably about ~.5 to 7.5) 2 5 hydantoin of the ~orm ~a f2H5 o E~ C - C ~
\C/ H

wherein R is methyl or ethyl; to form a precipitate and thereafter filtering, washing, and drying the material to obtain a product which may be charscterized as non-dusting and free-flowing. Desirably~ halogenatio is carried out at a temperature of from abollt 10 to 3DC.
The invention further provides for shaping the HEH products to form shape-retentive non-dusting forms such as blocks, briquettes, granules, etc. without the aid of a binder. The HEH lends itself to blending with other active halogen compounds, particularly chlorine substituted ones to form products useful for a variety o~ applications including inter-~lis disinfection and bleaching.
The invention further provides a methDd of producing a solid shape retentive form of halogenated hydantoin, ccmprising the step of formincJ the prcduct into a solid shap~d product form by compact-ing the hydantoin under pressure.

DETAILE~ DESCRIPIION OF THE INV~TION

HEH possesses significant properties which are substsntially different from those of the corresponding halo DMH compounds. Most noteworthy of such properties is the temperature spread between the melting point, typically in range of between about ~0C to about 70C, and the decomposition temperature, typically in the range of between E~bout 150C to about 170C. The significant spread between melting and d~composition temper~tures of HEH enhances solid product formation by fu~ing or c~sting techniques. Thus, in accordance w;th the present 5 (a) invention, fusing and casting of HEH products are made possible using techniques at elevated temperatures sufficient to melt the HEH and therefore mold same, but significRntly below the decomposition temperature thereof~
Microscopic examination reveals that Hl:H products of the present invention have ~ larger particle size and a more crystslline nature than the corresponding halo DMH compounds. Therefore HEH products can be pressure compacted into hard, extremely physically stable forms (e.g. extremely low dusting) without the need for special binders and/or :=

"cementing agents" which the prior art has heretofore thought were absolutely necessary to produce commercially acceptable products. Use of halo DMH compounds alone does not yield such advantageous and surprising results.
As a further embodiment, mixtures of H~:H and halo DMH can be prepared either by mixing DMH and either diethylhydantoin (DEH) or S-methyl-S-ethylhydantoin (MEH) in the desiredl predetermined quantities prior to halogination thereof. Alternatively, mixtures can be prepared in situ from the corresponding ketones, acetone, diethylketone and methyl-ethylketone, by utilizing the well known Bucherer-Bergs synthesis, and thereafter halogenating the product utilizing controlled pH conditions in accordance with the present invention.
Proper selection of the ratio of DMH to HEH in accordance with the present invention enhances the end product form desired. HEH
unlike halogenated DMH, is useful for making low-dust powders, granules, tablets, flakes, compacted forms, cast forms, and carrier-coated products. Halogensted DMH ~_r se cannot be used for any of the above purposes without the aid of a binder. However, halogenated DMH can be mixed with HEH to yield compositions useful for making all of the above forms. It is only necessary to select the proper ratio of the above forms to achieve the results desired. For example, the following ratios are useful in manufacturing the product forms shown.

DMH Com~ MEH Compo~
~ oles ~ A~ole~
Briquette B,C 0.9 B,C 0.1 Tablet B,C 0.9 B,C 0.1 C,C O.g C,C 0.1 Flake B,C O.S B,C 0.5 ~,C 0.5 C,C 0.5 ~ranule B,C 0.9 B,C 0.1 Low-dust powder E~,C 0.9 B,C 0.1 Compounded with B,C 0.5 B,C 0.5 inert carriers C,C 0.5 C3C 0.5 ~B,C = brornochloro C,C = dichloro The above are upper levels of DMH that should be used. Of course, the DMH can be reduced to 0 and the same results obteined. Obviously, any lesser amounts of DMH yields equally satisfactory results. In like manner, the HEEI materials of the present invention can be blended with inert fillers, other active halogen compounds, materials like psradichlorobenzene, and a host of other materials depending in the desired end use.
As noted, the prepar&tion of HEH is dependent upcn controlling (i.e. maintaining) the pH of the desired level during hslogenation. This can be done by periodic addition of base, e.g. sodium hydroxide.
The following examples are offered to further illustrate the present invention, but are not to be construed as limiting the scope thereof.

l~ample Vne (Comparative) Preparation of 1,3~ichioro 5-meth~ 5~thylhydantoin (DCMEH) DCMEH was prepared in accordance with the Patterson U.S.
Patent No. 2,779,764 procedure by placing 142 grams of 5-methyl-5-ethylhydantoin and S00 ml of distilled w~ter in a 2 liter beaker equipped with stirrer, pH probe and therrnometer. The solution was cooled to i 10C. 400 mls of a cooled (10C) 20% solution of NaOH were added to the MEH/water mixture. 176.3 grams of chlorine was added to the mixture over a period of about 2.5 hours. The pH of the rehction mixture W&S monitored and rose from pH=9 initially to R high pH=13.9 ~nd finally dropped to pH=7.2 ~t the conclusion of the reQction. The product, after vacuum filtering, washing and drying, weighed 194.7 gr~ms. It analyzed active halogen QS Cl+=33.4%. The product WQS a dusty powder and possessed a noffceable chlorine odor.

E~ample Two (Comparative) Preparaffon of DCM~H
~n accordance with the procedure outlined in Wolf et al, U.S.
Patent No. 2,090,997, 79.5 grams of sodium carbonate and 771.3 mls of water were ch~rged to a 2 liter beaker equipped with a stirrer, thermometer, pH probe and subsurface chlorine inlet tube. The mixture was stirred to dissolve the sodium carbonate whereupon 71.1 grams of MEH were added with stirring until it also dissolved. The resulting solution pH=9.78 wss warmed to 30C and 82.5 grams of chlorine gas slowly passed to the mixture until the pH dropped to 7.05. The product precipitated &S a semi-solid amorphous mass which hardened into clumps.
2 o The solid slurry was vacuum filtered, washed and dried yielding 98.3 grams.

I~xample Three Preparation of DCM~H-Controlled p~=6.5 142.2 grams of MEH were dissolved in 2700 mls of distilled water in a 4 liter beflker equipped with a stirrer, thermometer, pH probe, chlorine gas inlet tube snd sodium hydrox3de addition funnel. The solution W&S wsrmed to 40C to dissolve the MEH and then cooled to 22C. 156.6 grsms of chlorine gas were added slowly to the mixture over a period of sbout 1 hour and 50 minutes while maintaining the temperature between about 22-24C and the pH at ~bout 6.5 through the periodic addition of a 20% sodium hydroxide solution. The precipitated product was iltered, wsshed and dried to a weight of 197.7 grams. The analysis of the product for active halogen ns Cl+ was 33.5%. The material was free flowing with no apparent dusting or irritsting halogen odor.

E~ample ~our P~Plow Characeeristics S The flOw charQcteristics of the DC~IEH products of Examples One and Three were comp~red by determining the angle of repose for each product. Into two 4 oz. jars were charged twenty-two grams of the DCMEH products of Examples One and Three. The jars were both capped Each jar was tapped by raising the jar one inch off the table ~nd then 10 dropping. The jars were then tipped on their side end the angle of repose (i.e. the angle between the table and the sample incline) determined. The product of Example One did not flow9 but rather remained stuck to the bottom of the jar. The DCMEH product of Ex&mple Three flowed into an angle of 45 with rel~tion to the horizonltal. The angle of repose clearly 15 illustrates the free flowing nature of the products of the present invention.
The angle of repose of the product is not critical, but is merely a means of evaluating nOw characteristics. Ns flow would exhibit a 90 angle with the horizontal. Thus, products of the present invention 20 should exhibit an ~ngle of less than soG (e.g. less than ~0~ and readily flow to form an incline with the horizontal. The sample should not compact or cling to the bottom or walLs of the ~ntainer.
A free-flowing product is essential for manufacturing tablets ~nd compacting forms. It will be appreciated that any m~terial which is 25 to be compacted or tableted must flow freely into die cavities and into the pockets of compacting rolls. The material must be able to flow freely from containers, feed hoppers and to be screw-conveyed without bridging, sticking or holding~up in the equipment.

E~cnm~e Pive 30 Dusting Gharacteristics The HEH products of the present invention are further ch~racterized by their low-dusting properties. This example illustrates

3~3~ o li the relative dusting properties of DCMEH prepared according to the present invention when compared to other materials.
Apparatus was set upt to determin~ the relative dusting characteristics HEH materials. The apparatus consisted of a 16 inch diameter cylinder (24.25 inches high) having a slot in the side approxi-mately 1 inch wide x 8 inches long (starting 6 inches up from the bottom).
A large piece of filter paper (Whatman 32 cm #1) is placed on the bottom of the container. On the filter paper (in the center) was placed a 100 mm x 10 mm petri dish. A plastic funnel (4.25 inch OD top x 0.75 inch OD
bottom) was aligned directly above a 13/16 inch diameter x 4 inch glass tube held with the aid of ring clamps and positioned 8 inches above the petri dish.
The DCMEH samples of Examples One and Three were evalu-ated independently for dustiness. ~.5 grams of I)CMEH samples from Examples One and Three were placed in a 50 ml beaker. The samples were dumped quickly (with a moderate tap on the funnel) into the funnel.
The petri dish containing most of the sample was removed and the filter paper placed on a clean level surface. Using an atomizer sprayer, the filter paper was then sprayed with a 15% aqueous solution of potassium iodide and allowed to dry. Against a black background, the filter paper which was placed beneath the DCMEH of Example One revealed dusting over its entire surface. By contrast, little dusting was evidenced on the paper placed under the material of Example Three.
As can be seen the HEH material of the present invention exhibits significantly little dusting.

E~cample Six Preparation of DCDEH
A sample of 1,3-dichloro-5,5-diethylhydantoin was prepared by chlorinating 51.5 grams of diethylhydantoin (obtained from the reaction of 3-pentanone, potassium cyanide and ammonium carbonate at 60C) with 57.4 grams of chlorine gas at a control pH of 7.15 to 7.5 using 20% solution of sodium hydroxide at a temperature of 15-23C. The reaction was carried out in the same manner as Example Three to yield 65.1 grams of DCDEH having an analysis of total halogen=30.7. The product was free flowing and had little chlorine odor~ MP=44.5.48C.
Decompo~ition Temperature=151C.

Preparation of BCDEH
Bromochloro-5,5 diethylhydantoin was prepared by chQrging 39 grams DEH, 25.7 grams sodium bromide and ill7.4 mls of distilled water to a two liter flask equipped QS in Example Three. The mixture was then chlorinated with 45.2 grams of chlorine at a ~ontrolled pH of 7.3-7.60 using a 20% solution of NaOH at a temperature of 16-24C. The product was filtered, washed and dried as in Example Six to yield 63.0 grsms of a free-flowing low-dusting product haYing an analysis of total halogen=59.3%; MP=82-96 C; Decomposition Temp.=139C.
1,3-Dichloropentamethylene and 1!3-dichlolo-5,5-diphenylhy-dantoin were ~lso prepared according to the present method. However, due to the small difference between the melting point and decomposition tempersture of these materials, they ere not suitable for the present invention.
While the present example utilized NaBr to generate bromine, it will be apprecisted that elemental bromine may be employed in a manner simil~r to the use elemental chlorine above.

E~ample Eight HEH Melt 81ends A mixture of 0.5 moles of dimethylhydantoin (DMR), 0.5 moles methylethylhydantoin (MEH) and 0.5 sodium bromide was chlorinated in accordance with the procedure of Exsmple Seven. The h~logenated MEH/DMH product had a melting rsnge of 65-121C and a decomposition temperature of 180C. The product w~s fluid at 70C.
15 grams of the product were melted in a 100 ml beaker over a steam plate, ~nd then 15.0 grams of sodium tripolyphosph~te (STP) were blended into the melt with the aid of a stirring rod. Upon cooling the mixture solidified to a free flowing granular product which gave off a light to moderate chlorine odor ~nd exhibited no dusting.

Similarly, 15 grams of the halogenated MEH/DMH product were melt blended with 15 grams of soda ash. The resulting granular pro-duct was free-flowing exhibited no dusting and only a light chlorine odor.
Like results were obtained with 50:50 blends of the halo-genated MEH/DMH with anhydrous sodium sulfate, talc, Bentolite L, mineral colloid, Zeolite Types 4A and sodium chloride.

E~amele Nine Combinatior~s of HEH With Active Hal~n Compound~s A series of solid melt blend products were prepared by melt blending at 55-70C the halogenated MEH/DMH (referred to below as H-MEH/DMH) material obtained in Example Eight or DCMEH with various active chlorine compounds. The melt blends were allowed to solidify in ice cube trays. The blends included:

% HEH Active Chlorine and t~pe ComPound 90% H-MEH/DMH 10% sodium dichloroisocyanurate (NaDCC) 70% H-MEH/DMH 30% NaD(: C
50% H-MEH/DMH 50% NaDCC
90% H-MEH/DMH 10% trichloroisocyanuric acid 9096 DCMEH 10% Ca(OCl)2 90% DCMEH 10% LiQCl 90% H-MEH/DMH 10Ca(OCl)2 The products exhibited no dusting and gave off light to moderate chlorine odor. These type of products are particularly suitable for applications in spas, swimming pools, urinal or toilet bowls, disinfee-tion where both an immediate and sustained release of halogen is desired.

_ample Ten HEH Combined with Paradichlorobenzene This example illustrates that the HEH materials of the present invention are suitable for preparing urinal blocks from melt blends of HEH and paradich~orobenzene (PDCB).

Ten grsms of the H-MEH/DMH material used in Example Nine were melt blended at 54-55C with 10 grams of PDCB in the SQme manner ~s outlined in Exampae Nine to give a slightly yellow cube blo~k which exhibited no dusting and smelled only of PD~B.
Similarly blocks were made by melt blending ' grams DCMEH
~nd 5 grams PDCB. Again no dusting was evident and only the smell of PDCB observed.

Example E:le~n ~ ~ ~orms A series of compacted products were made from the HEH
material of the present invention. Durable granules, briquettes, and tablets were prodllced by the following techniques.
Granules were produced continuously via an integrated roll compaction, granulation and screen classification system. Powder was fed continuously from a feed hopper to a roll compaction machine equipped with rolls to produce sheet compactO The efnuent compact was fed by gravity to a Rietz granulator operated under controlled "grind"
conditions dictated by the final size granules desired. Effluent from the gr~nulator flowed by gravity to a screen cl~ssification system designed to separate grenulated materi~l into desired size fractions ranging from less than 6 U.S. Sieve mesh to greater than 200 mesh.
9 cc briquettes were produced directly from the roll compac-tor cited above using conventional type briguetting rolls. The physical durability of these briquettes was ve, if ied by shipping a 40 pound sample approximately 6,000 miles by truck. Less than 2% ~ttrition or breakage was observed as measured by sieving the briquettes through a 1/4 inch mesh screen.
13 cc tablets were QISO produced continuously utilizing a rotary tableting press.

Example Twelve Products were prepared utilizing various quantities of DMH, MEH and N~Br and the procedures ouUined in Example Seven. Such ~3~

products were examined for their physicQl charscteristics, the results being recorded in TRble 2 below.

T~b!e 2 alo~enated ~ydantoins Produ~t Moles Moles A~oles Meltir~ Des!omposition No. DM~I bqEHN~Br R~e (C) Temp. (C) I~A 1.0 0.0 0.0 132-134.5 191 ~B 1.0 0.0 1.0 lSB-165 160 3C 0.O 1.O o.o 60~4 170 4D o.o 1.0 1.0 74-79 148 0.8 0.2 0.5 1~8-142 180 6 0.8 0.2 0.8 1 46-1 63 1 80 7 0.8 0.2 1.0 139-157 ]71 8 0.5 0.5 0.5 65-121 180 9 0.5 0.5 0.8 73-133 155 1 0 0.5 0.51 .0 73-1 39 1 67 1 1 0.2 0.8 ~.5 59~8 176 12 0.2 O.g 0.8 69-88 145 13 0.2 0.8 1.0 71 95 160 2 0 * Comp~r~tive A DCDMH
B BCDMH
C DCMEH

TQble 2 ~Cont.) ~lalogen~ted }lydantoiEts Produ~t ~o App~n~e l~A Pine Powder Heavy 2 B Fine Powder Hea~7y 3 Grainy Powder Medium 4D Grainy Powder Medium Granular Trace 6 Semi~rsnular Trace 7 Grainy Powder Medium 8 Granular Trace 9 Grainy Powder Light Gr~iny Powder Tr~ce 11 ~3r~nular Tra~e 12 Semi{~ranular Light 13 Gr~iny Powder Light Comparative A DCDMH
2 o B BCDMH
C DCMEH
D BCMEH

Table 2 (Cont.) ~nated E~t0i~s Produet ~lo~ C:~t~ Plalc~ CompQcffon ~nd No. ~Q ~Q ~ Grsnulstion 1 (Compar~tive) - - - Poor 2 (Comp~rstive) - - - Poor 3 + + + ExcelL

4 ~ + + Excell.
~ ~ ~ Excell.
S ~ + ~ Excell.
7 + - - Excell.
8 + + + Excell.
9 ~ + ~ ExeelL
l O ~ ~ + Excell.
I 1 + + + Excell.
12 + + + Excell.
13 + + + Excell.

3~

As can be readily appreciated from the above examples and the tabulated data of Table 2, the products of the present in~ention are more crystalline~ granular, free-flowing and exhibit significantly less "dusting" than other halo hydantoins (e.g. compare product Nos. 3-13 to products Nos. 1-2 in Table 2). The halogenated products of the present invention facilitate comp ction and the forms thus produced have greater physical integrity (e.g. hardness, resistance to breaking, ease of tableting without "capping", and the like) when compared to other halo hydantoin derivatives.
Moreover, the products of the present invention which include increased amounts of MEH exhibit markedly reduced melting tempera-tures and R significant differential between such melting temperatures and decomposition temperatures. This increased differential between melting and decomposition temperatures permits formation of final products by fusion or partial melting techniques~ Thus, when the melt or partial melt is case or extruded into forms of the desired shape or flaked by pouring or placing the melt onto a cool surface, product forms result which are physically stable, hard and dust free.
As can be seen from the foregoing examples, the unique properties of the HEH materials permits the manufacture of unique products which would not be otherwise possible. Because of the low melting point of the preferred hydantoins, they may be:
1) melted, mixed with inert carriers, and then allowed to cool and solidify;
2) mixed as solids with inert carriers, heated until the hydantoin melts, and then cooled to solidify the hydan-toin; and 3) melted and sprayed onto the surface of inert carriers.
The products thus prepared may be either surface coated, or impregnated with the HEH. The products are non-dusting, granular, free flowing. The inert carrier selected is appropriate to the intended end use, e.g., bleaching, scouring powders, dishwashing compositions, water treat-ing chemicals, toilet bowl disinfectants and deodorizers. The product characterization can be adjusted to fit the application, e.g., rate of ~ ~ t ~ fl solubility, dispersibility, ~oncentration, eompEtibility with other formulation ingredients, etc.
While the present invention has been herein described in what is presently contemplated to be the more preferred embodirnents thereof, those in the art may ~ppreciate that many modifications may be made hereof, which modifications shQll be accorded the broadest interpretation of the appended claims so as to encompass all equivalent methods, processes and/or materials.

Claims (13)

WHAT WE CLAIM IS:

1. A method for the production of a free-flowing, non-dusting halogenated hydantoin product which comprises halogenating under controlled pH conditions of from 6.0 to about 8.0 a hydantoin of the formula wherein R is methyl or ethyl; to form a precipitate and thereafter filtering washing and drying the product characterized as non-dusting and free-flowing and having the formula wherein R is methyl or ethyl and X1 and X2 which may be the same or different is chlorine or bromine.

2. A method according to claim 1 wherein the pH is controlled at from about 6.5 to 7.5 by the addition, during halogenation, of sodium hydroxide, and wherein halogenating is carried out at a temperature of from about 10 to 30°C.

3. A method according to claim 1 wherein the hydantoin is 5-methyl-5-ethylhydantoin, and the product obtained has an angle of repose of less than 70°.

4. A method according to claim 1 wherein dimethyl hydantoin and an alkali metal bromide are present during halogenation.

5. A non-dusting, free-flowing halogenated hydantoin of the formula:

wherein R is methyl or ethyl, and X1 and X2 which may be the same or different, is chlorine or bromine.

6. A non-dusting, free-flowing halogenated hydantoin of the formula:

wherein R is methyl or ethyl, and X1 and X2 are the same and are chlorine or bromine.

7. The hydantoin of claim 5 blended with an active chlorine compound.

8. The hydantoin of claim 5 or 6 blended with dimethylhydantoin or with a halogenated dimethylhydantoin.

9. The hydantoin or claim 5 or 6 blended with an active chlorine compound and with dimethylhydantoin or with a halogenated dimethylhydantoin.

10. A method of producing a solid, shape retentive form of halogenated hydantoin, said method comprising the step of forming the product of claim 5, 6 or 7 into a solid shaped product form.

11. A method of producing a solid, shape retentive form of halogenated hydantoin, said method comprising the step of forming the product of claim 5, 6 or 7 into a solid shaped product form, wherein the step of forming is practiced by compacting the hydantoin under pressure.

12. A method of bleaching textile articles comprising treating the articles in an aqueous environment with an amount effective to bleach said articles of a solid shaped product produced by a method comprising the step of forming the product of claim 5, 6 or 7 into a solid shaped product form.

13. A method of bleaching textile articles comprising treating the articles in an aqueous environment with an amount effective to bleach said articles of a solid shaped product produced by a method comprising the step of forming the product of claim 5, 6 or 7 into a solid shaped product form, and wherein the step of forming is practiced by compacting the hydantoin under pressure.