US2921911A - Oxidizing compositions - Google Patents

Description

OXIDIZING COMPOSITIONS Julian L. Staubly, Oreland, and Joseph Simlrin, Philadelphia, Pa.,' Otto T. Aepli, Wyandotte, Mich., and John E. Rex, Pasadena, Calif., assignors to Pennsalt Chemicals Corporation, Philadelphia, Pa., a corporation of Pennsylvania No Drawing. Application January 10, 1958 Serial No. 708,065

15 Claims. (Cl. 252-487) This invention relates to treating finely-divided solid particles with added materials to render them substantial- 1y dustless and to the resulting compositions. More particularly, this invention relates to compositions and methods of treating strong oxidizing agents with liquids in order to render them dustless.

Finely-divided strong oxidizing agents are in many cases very dusty and, in such a condition, have only a limited number of industrial applications. The dusty condition of the oxidizing agents may be caused by excessive grinding during manufacture, or the fines may be caused by handling, packaging, and shipping. In the usual case, the dusts of the strong oxidizing agents are .exceedingly irritating to the eyes, nose and throat of any person handling them. In many cases the skin of workers exposed to dusts from strong oxidizing agents may break out in rashes and sores. The irritation may be so severe that workers will refuse to handle them. In addition to the annoyance caused to persons handling the dusty materials, chemical damage may occur where the fines from strong oxidizing agents settle on painted surfaces, or other materials where chemical action induced by the oxidizing agent takes place.

A special problem in this connection is the use of calcium hypochlorite in laundry service. A new laundry bleaching practice today requires that dry finely-divided calcium hypochlorite be added to every batch of wash for bleaching purposes. This requires a scooping-up. of calcium hypochlorite out of a drum for every washer full of clothes. Further, it is necessary that the calcium hypochlorite for direct application to the Wash wheel in laundry bleaching be of exceedingly fine particle size for quick solution in order to efiect bleaching action in the short washing cycle. And, it is particularly important to have a finely-ground hypochlorite in order that local high-concentration points are avoided which would otherwise tend to weaken the fabrics. It is also essential that any liquid dedusting agent incorporated with the bleaching powder must rinse readily from the clothes being washed by the action of water alone or by water plus soap or detergent.

' The general requirements of a satisfactory dedusting agent are that only a small amount need be added to efiect the desired action, that it does not induce tackiness 2,921,911 7 Patented Jan. 19, 1960 or caking of the finely-ground materials, and that the modifying agents are of low volatility in order that they may be long lasting. For example, carbon tetrachloride and perchloroethylene are too volatile. As a general rule a material having a boiling point under 212 F.

would be unsatisfactory, and preferably it should not boil under 300 F. In the case of the strong oxidizing agents, two very important requirements, in addition to those enumerated above, are that the modifying agent does not increase the fire or explosion hazard, and that the normal storage stability is not adversely affected. For example,

in the case of calcium hypochlorite which can undergoa steady non-violent decomposition with loss of available chlorine while in storage, this rate of decomposition must not be accelerated to any appreciable extent. Any serious increase in the storage decomposition rate caused by a' dedusting agent would prohibit its use. While certain organic solids have been incorporated with strong oxidizing agents for detergent purposes without increasing the explosion potential, organic liquids have not been used, primarily because the organic vapors generally increase the explosion hazard by lowering the spontaneous decomposition temperature.

In general, the prior art methods of dedusting commonly employ the addition of white mineral oils and. polyhydric alcohols, such as glycol, sorbitol, mannitol' and erythritol. All of these materials are unsatisfactory for use with the strong oxidizing agents, such as inorganic hypochlorites and N-chloiosubstituted compounds because of the increase danger of fire or explosive decom presence of the added organic Ina-- position due to the terial.

Because of the increased fire and explosion hazards caused by the added liquid materials, industry has sought to overcome the dustiness of strong oxidizing agents by other methods. Probably, the most important of these methods is that of densification. In this method forces are applied to compact finely-divided particles in order to produce aggregates which are not dusty. While this produces a non-dusty product, the added cost of the increased processing proves quite burdensome. Moreover, as in the case of inorganic hypochlorites, such as lithium and calcium hypochlorite, densification is undesirable in those applications where rapid solution of the hypochlorite fines is essential.

Another method of treating inorganic hypochlorites and other strong oxidizing agents is that of Robson et al.,

US. Patent 2,195,757, wherein finely-ground hypochloritematerials are mixed with water and air to produce a plastic mass which is then dried, crushed and screened in order to produce a uniformly-sized product. While this process appears to produce a dustless product, the

increased processing required is prohibitive in the case of the average industrial chemical. Moreover, the added In addition to the cost,

densification is unattractive because of the decrease in the rate of solubility due to the increased particle size. Screening operations are satisfactory except that the removed fines must be reprocessed or discarded. In addition, screening does not help with those products'which.

chlorinated hydrocarbon having a flash point in excess of 180 C. The new compositions of matter produced by our process comprise the addition of liquid chlorinated biphenyl containing about 48 to 54%. chlorine to a compound selected from the group consisting of inorganic hypochlorites and N-chloroj-compounds in amounts so that the additives comprise 0.5 to 5.0% by weight'of the 7 final mixture. v p 7 V Theliquid organic materials which. are satisfactory addition agents to solid finely-divided strong'oxidizing agents are chlorinated biphenyls having a flash point in excess of 180 C. The flash point herein referred to is that as obtained by the Cleveland open cup method.

In the case of chlorinated biphenyls and chlorinated polyphenyls the flash point in excess of 180 C. is not obtained until the chlorine content is approximately 48%. These same materials with a chlorine content of only 42% have a fiashpoint ranging from 176 to 180 C.

Similarly, the polyphenyls chlorinated to 54% chlorine which have no measurable flash point are very desirable for our purposes. The polyphenyls chlorinated above 54% are no longer liquids and hence not useful inrpracticing our invention. Whenever used in'this application,

the term chlorinated biphenyl is intended to include mix-- tures of chlorinated biphenyl and chlorinated polyphenyls as well as the relatively pure chlorinated biphenyl. erence is also frequently made in this application to materials by the name of Aroclors followed by a number. Aroclor is a trade name used by the Monsanto Chemical Company to designate their series of chlorinated biand poly-phenyls. number following the name indicate its chlorine content. For example, Aroclor 1248 indicates armixture of hiand polyphenyls chlorinated to 48% chlorine content.

The amount of these materials which must be added to the solid finely-divided strong oxidizing agents'will The last two digits of the four digit 4 r the time for the combustionto proceed to the other end of the train was noted.

Calcium hypochlorite without any additive could not be ignited with a Bunsen flame. With the addition of .2 /2% by weightof the final mixture of Aroclor 1254 calcium hypochlorite could not be ignited nor reaction initiated. With 5% Aroclor, in one test no ignition took place, while in a second test, a non-luminous exothermic reaction took place and progressed the 1 foot distance in about 200 seconds. When the additive was increased to 7 /z% Aroclor, the calcium hypochlorite was readily ignited, and combustion progressed the one foot test distance in 8 seconds.

From the above data it is readily observed that calcium hypochlorite containing 7 /z% Aroclor 1254 is readily combustible and will propagate a flamein a rapid manner. Calcium hypochlorite containing less than 7 /z% Aroclor 1254 does notreadily support combustion and will not rapidly propagate with a flame or ignition.

A mixture consisting of57% calcium hypochlorite,

2% Aroclor 1254 and 41% sodium chloride could not vary depending on the particular solid oxidizing agent being dedusted. In some cases the addition of 0.5% of the modifying agent will produce compositions which are substantially free from dust and can be handled by workers in the open without annoyance. "Higher amounts. of course can be used up to about 6% of the weight of the final mixture. The addition of amounts greater than 6% generally creates a wet-appearing mixture which in many cases is no longer free-flowing. In the case of calcium' hypochlorite'mixtures containingas much as 10% Aroclor 1254', the material'became packed in the container on storage. It is also usually prohibitive from an economic standpoint toadd more than 6% of a modifying agent. The incorporation of less than, 0.5%. of a dedusting agent of the types mentioned above will generally not alleviate the dusty. condition of such compositions.

In addition to the above reasons for limiting the. additive to about 6% by weight of the final mixture, flame one end of the train and whereignition did. take. place be ignited nor would a flame propagate in the above test.

A mixture consisting of 12% calcium hypochlorite, 60% sodium tripolyphosphate and 26 /z% sodium .chloride and l /2% Aroclor 1254 could not beignited nor would a flame propagate in the test described above.

A mixture comprising 20% trichloroisocyanuric acid, 20% tripolyphospha-te, 59%' sodium chloride and 1% Aroclor 1254 would fuse and char in the presence of a burner but would not ignite nor propagate a flame. Similarly, a mixture consisting of 24.5% dichloroisocyanuric acid, 20% sodium tripolyphosphate, 54% sodium chloride and l /2% Aroclor 1254 wouldv not propagate a flame.

The above work with calcium hypochlorite indicates that concentrations in excess of 5 or 6% of Aroclor 1254 are much more dangerous from a flame propagation standpoint. Thus, in order to avoid high concentrations of the dedusting liquid in contact with a strong oxidizing agent it is essential in formulating these materials that the dedusting liquid be added to the inorganic diluent and first blended with it andthereafter the mixture of the inorganic diluent and the Aroclor can be blended with the strong oxidizing agent. 'By this manner high con-centrations at specific points in the processing equipment can be avoided, and the danger of spontaneous ignition and combustion of/the entire equipment containing the mixture can thus be avoided.

It should also be kept in mind in compounding. these mixtur e's that chance contamination from organic materials should boa voided whenever possible. Thus, in designing equipment to elfect the blending of the compositions adequate facilities should be provided for cleaning and removingany chance contamination. Points to be considered are fume exhaust ducts, product conveyors and dumpflshoots. All of these should be readily cleaned from any prior contamination before the equipment is used in dedusting the formulations of the strong oxidizing agents. V

The f particular solid finely-divided oxidizing agents which have been satisfactorily treated withliquid chlorinated biphenyls containing about 48 to 54% chlorine to produce substantially dustless compositions are inorganic hypochlorites and N-chloro-compounds.

A strong oxidizing agent as used throughout this specification is a chemical compound which readily induces a chemical reaction whereby an increase of positive charge of a cation takes place. Specific examples of strong oxidizing agents within the above classes are as follows: inorganic hypochlorites-calcium hypochlorite,

'lithium hypochlorite and trisodium orthophosphate-sodium hypochlorite; N-chloro-substituted compounds-p-toluene sulfonechloroamide, N,N-dichlorodimethylhydantoin, Nch1orosuccinimide, trichloromelamine,Vdichloroiso:

for any purpose because the organic vapors of the added liquid were believed to greatly increase the explosion hazards by lowering the spontaneous ignition temperature.

Conversely, the presence of inert inorganic diluents by the very fact of dilution renders strong oxidizing agents less susceptible to spontaneous decomposition.

Because of this, we never dedust strong oxidizing agents directly with the liquid chlorinated biphenyls containing about 48 to 54% chlorine for commercial purposes but always apply the dedusting agent to an inert inorganic diluent prior to mixing with the oxidizing agent.

One of the inorganic hypochlorites, calcium 'hypochlorite, is usually available in the commercial form. By commercial calcium hypochlorite it is intended to mean the products currently sold in commerce which principally contain Ca(OCl) The term is intended to include relatively pure Ca(OCl) as well as those hypochlorite products which contain impurities and/or diluents such as sodium chloride, calcium chloride, calcium hydroxide and calcium chlorate.

The trisodium phosphate-sodium hypochlorite compound may be made in accordance with the instructions in U.S. Patent No. 1,965,304.

For commercial sale strong oxidizing agents are often used in mixtures with an inorganic diluent or extender, and it is intended that the application of the organic liquid dedusting agents to these mixtures is within the scope of our invention. New compositions produced by our novel process include those in which the solid finely-divided oxidizing compound is the major constituent, as well as those in which the inorganic diluent may be the major constitutent along with, of course, 0.5 to 6.0 parts of a liquid chlorinate biphenyl. By a major portion is meant a composition in which the particular ingredient is present in a proportion of more than 50% by weight. When the term minor proportion is used in this application, it is used to indicate that there is less than a 50% by weight of that material present. r

Whenever parts or (percent) is used throughout the specification and claims, it is meant percent by weight. Examples of inorganic diluents which do not affect the spontaneous ignition temperature or other fire or explosive characteristics of strong oxidizing agents are calcium chloride, sodium chloride, sodium sulphate and similar materials.

Our invention is also applicable to mixtures of strong oxidizing agents and certain inorganic detergent salts. For example, carbonates, hydroxides, silicates, phosphates and borates have been found to be useful additives to strong oxidizing agents for detergent purposes. Such mixtures have been successfully dedusted by the halogenated hydrocarbons of our invention. Carbonates useful in these compositions are sodium carbonate, so-

dium acid carbonate, potassium carbonate and sodium sesquicarbonate, while useful alkalis are sodium and potassium hydroxides. Sodium orthosilicate and sodium metasilicates have also been found useful as detergents along with sodium metaborate and sodium tetraborate as examples of useful borate type materials. Of the phosphates, sodium tripolyphosphate, tetra sodium pyrophosphate, sodium tetraphosphate and sodium hexametaphosphate have been found useful both for their detergent properties as well as their calcium sequestering l? properties. The latter type of detergent salts are particularly suitable for inclusion with the calcium hypochlorite wherein application is made in aqueous solution. Trisodium phosphate is also useful for its detergent properties in conjunction with the strong oxidizing agents. It is of course well recognized that some of the potassium salts of the above phosphates and carbonates can be successfully used but that economic considerations generally require the use of the sodium salts.

The liquid chlorinated biphenyls of about 48 to 54% chlorine content of our invention are also useful for dedusting strong oxidizing agents when combined with a certain solid alkyl aryl sulfonate wetting agents such as the type as disclosed in U.S. Patent 2,415,657. Examples of this type of wetting agents are dodecyl benzene sodium sulfonate, sodium sulfonate of the condensation product of chlorinated kerosene with benzene and alkyl naphthalene sodium sulfonate. Similarly, the solid wetting agents found compatible with calcium hypochlorite, as disclosed in U.S. Patent 2,320,280 can also be successfully used in the practice of our invention.

Examples of this type of wetting agent are sodium lauryl sulfate,-sodium ethylene palmitate sulfonate and sodium ethylene methyl lauramide sulfonate.

Because ofthe possibility of the inclusion of dangerous organic matter as by-products or unreacted ingredients in the'wetting agents, it is always recommended that small test blends be formulated and carefully tested before commercial quantities are prepared.

It is to be understood of course that strong oxidizing agents which can be successfully dedusted by the application of liquid chlorinated biphenyls in accordance with our invention include mixtures of the added detergents, sequestering agents, wetting agents and inorganic diluents as well as compositions wherein only one added material is used. It must be remembered that the dedusting liquid is first added to the inorganic material before it is combined with the strong oxidizing agent. Examples of two such mixtures in combination with calcium hypochlorite are as follows:

' Percent by weight Calcium hypochlorite The compositions in the table immediately following, which are illustrative of our invention were prepared by placing the sodium chloride in a suitable container and then blending in the liquid dedusting agent by adding it in a time stream while the sodium chloride was being agitated by the blending equipment. After mixing the calcium hypochlorite was added and blended. The blended product was then shaken in a closed container. After the shaking was discontinued, the sample was then held motionless and the presence of the dust, if any, above the solids was noted visually as a cloud. In the case of calcium hypochlorite, this testing procedure was supplemented by bringing the shaken container close to the nose after the lid had been removed. The presence of Ca(OCl) dusts is readily observed by the burning sensation produced in the nostrils.

The following compositions illustrate dedusting a mixture of a solid finely-divided strong oxidizing agent and .7 e an inert inorganicv diluent by the addition of a liquid chlorinated biphenyl of 48 to 54% chlorine content:

thermometer is also placed in the 'Woods rnetalrbath. Spontaneous decomposition occurs when one of the fol- ()xidizing Agent (Partsiby weight) inorganic Diluent (Parts by weigh v Dedusting Agent Dedusting Effect (Parts by weight) Calcium hypochlorite i 54 Sodium chloride (41% x cioi- 1254 (5 males.. Calcium hypochlorite (56)-. 7 Sodium chloride (43 Aroelor 1254 (l) Substantially dustless.

Sodium chloride (41)- Sodium Calcium hypochlorite l (56).---.

Dichlorodimethylhydantoin (37. 'Sodium carbonate 12.5) -Do Sodium carbonate (12.25). Do Sodium carbonate (11.0) D Sodiumcarbonate (9.5) Do Sodium 'carbqnate (8.5).---

N-chlorosuc Sodium chlor de (25.0 Do... p Sodium chloride Chlorinat orthoph osphate (50.0)

Chlorinated jtrisodium orthophosphate (49.75) Chlorinated trisodiurn orthophosphate (417.5) Chlorinated-trisodium orthophospbate (47:0) Cblorir iatedtrisodium orthophosph'atfe (45.0)

ChloramiiieT (25.0 "sodium;uirailiifiiiiilil Chloram ine '1 Sodium sulfate (24.75).

Do." Sodium sulfate (2 3,5)

Sodium sulfate (22) Sodium sulfate-(21.0)

Aroclor 1248 (5)- Aroclor 1254 (0) Dusty. Aroclor 1254 (0.25) Slight dedusting. Aroclor 1254 (1.5). Satisfactory dedusting. Aroclor 1254 (3.0). Do. Aroclor 1254 (4) Do. Arolcor 1254 (0.0)- Slightly dusty, some tendency to cake. I Aroclor 1254 (0.25)... Satisfactory dedusting, slight tendency to cake. Aroclor 1254 (0.0). Dusty. l Aroclor 1254 (0.25). Satisfactory dedusting. Aroclor 1254 (1.5). Excellent dedusting.

Aroclor 1254 (3.0) 4. Slightly moist appearing. Aroclor 1254 (4.0). Excessively moist appearing. Aroclor 1254 (0:0) usty. Aroclor 1254 (0.25 Slight dedusting. Aroclor 12540.5) Satisfactory dedusting. V 1 Aroclor 1254 (3.0) Excellent dedusting, slightly moist. Aroclor 1254 (4.0)..-.

Lumps.

1 Commercial grade. f

A test designed to show the efiect of theaddition of I Origi- Avail- Availnal able 4 able Composition (parts by evailchlor- Bei cent chlor{ Percent w. ght) able ine after loss in4 ine after loss in8 chlor- 4 weeks weeks 8 weeks weeks ine,-perstorage, storage, cent percent percent Calcium hypochlorite 1 (56).. Sodium chloride (43) 36.0 34. 7 3. 6 34. 6 I V 3. 9 Aroclor 1248 (1) v Calcium hypochlorite 1 (56)-- Sodium chl0ride(43)-. 36.7 35.1 4.4 33.5 8.7 Aroclor 1254 (1) j Calciumhy-pochlorite (57)-. i Sodium chloride (43) 36. 6 35. 4 3. 3 I a 32:6 10.1 Modifying agent' (0);

Commercial.

From the results as indicated in the above table, it is readily'apparencthat the addition'of dedusting agents has not accelerated the normal-storage decomposition rate. From comparison with the control .it could even be. said that the storage stability of J the' calcium hyphochlorite has ber'ibene'fi tdby the' addition agent. A low storage decomposition rate is important in commercial sales of calcium hypochlorites in order to maintain a high available chlorine product in spite 'of extended'storagc periods.

In the shipping of strong oxidizing agents to various points'thioughout the world various temperature extremes are encountered. Since these materials have a tendencyto spontaneously decompose at elevated temperatures, a maximum temperature limit to which'these 'rnaterialscan be subjected without danger of fire or explosion is usually established by the manufacturer. It is generally recognized that a calcium hypochlorite should not have a spontaneous decomposition temperature below 170 C. Similarly, any dedusti ig agent which is added to the calcium hypochlo'ri te must not lower the spontaneous decomposition 'temper aturesbelow 1703C. V I

The spontaneous decompositori temperatures may be m'easuredby placing a lO-gram sample of the composition in-an 8" test tube. Then, a thermometer-i s.inserted into the composition after which the test tube placed in. a Woods'inetalb'a'th and the bath is gradually heated. A

Spontap ncous v I Decom- Composition (parts by weight) position Typeof Explosion Tempere p ature, 1 no Calcium 'hypochlorito (54) Sodiumfchloride(41)-. Mild; Aroclor 1254 (5 I Calcium-hypochlorite 1 (5 I Sodium chloride (41)..-. 178 Do. Aroclor 1248 (5). V 'sli-(ifihlorttiisocyangric alcitd (20 a Y a o um 'IlDO yp osp a e Sodium bhloride (59) 235 Productpartially fused. Aroclor 1254 (1).. T i lgighlorotisocylanililricarentl (2:65) a g 0 mm ripo yp osp a e a sodium chloride (54) 235 Product tused slightly Aroclor 1254 (1.5) a

class consisting of inorganic hypochlorites and N-chlorm substituted compounds andsufiicient chlorinated biphenyl containing about 48 to 54% chlorine toprovidc 10.5 to

6.0% by weight of the final mixture.

2. The mixture comprising a solid; finely-divided, inert inorganic diluent, selected from the class consisting of sulfates, chlorides, carbonates, hydroxides, silicates, phosphates and 'bo-rates, at least 10% by weightof a solid,dinely-divided, strong oxidizing agent selected :from the class consisting of inorganic hypochlorites and Nchloro-rsubstituted' compounds and sufficient chlorinated biphenyl containing about -48 to 54% chlorine Ito provide 0:5 to 6.0% by Weight of thefinal mixture.

3. The'rnixture comprising a solid, finely-idivided,-=iner.t inorganic diluent, at least 10% 'byxweight 'of ia'isolid, finely-divided inorganic hypochlorite and sufficient 'clilorinated biphenyl containing about 48 ;to 54% chlorine to provide 0.5 to 6.0% bjy'weight 'of the final-mixture.

4. ,The composition .ofclaim 3 .in:.which the inorganic li'ypochlor'ite is calcium hypochlorite.

5. The composition of claim 3 in which the inorganic hypochlorite is lithium hypochlorite.

6. The composition of claim 3 in which the inorganic hypochlorite is chlorinated trisodiurn orthosphosphate.

7. The mixture comprising a solid, finely-divided, inert inorganic diluent selected from the class consisting of sulfates, chlorides, carbonates, hydroxides, silicates, phosphates and borates, at least 10% by Weight of a solid, finely-divided, inorganic hypochlorite and sufiicient chlorinated biphenyl containing about 48 to 54% chlorine to provide 0.5 to 6.0% by weight of the final mixture.

8. The mixture comprising a solid, finely-divided inert inorganic diluent, at least 10% by Weight of a solid finely-divided N-chloro-substituted compound and sufficient chlorinated biphenyl containing about 48 to 54% chlorine to provide 0.5 to 6.0% by weight of the final mixture.

9. The composition of claim 8 in which the N-chlorosubstituted compound is dichloroisocyanuric acid.

10. The composition of claim 8 in which the N-chlorosubstituted compound is trichloroisocyanuric acid.

11. The composition of claim 8 in which the N-chlorosubstituted compound is 'dichlorodimethylhydantoin.

12. The composition of claim 8 in which the N-chlorosubstituted compound is p-toluene sulfonechloramide.

13. The composition of claim 8 in which the N-chlorosubstituted compound is N-chlorosuccinimide.

14. The composition of claim 8 in which the N-chlorosubstituted compound is trichloromelarnine.

15. The mixture comprising a solid, finely-divided, inert inorganic diluent selected from the class consisting of sulfates, chlorides, carbonates, hydroxides, silicates, phosphates and borates, at least 10% by weight of a solidfinely-divided N-chloro-substituted compound and sufficient chlorinated biphenyl containing about 48 to 54% chlorine to provide a 0.5 to 6.0% by weight of the final m'mture.

References Cited in the file of this patent UNITED STATES PATENTS 1,609,328 Taylor Dec. 7, 1926 1,892,548 Feibelmann Dec. 27, 1932 2,157,558 Muskat et al May 9, 1939 2,195,757 Robson et al Apr. 2, 1940 2,398,599 Rogers Apr. 6, 1946 2,556,953 Young June 12, 1951 2,578,270 Strain Dec. 11, 1951 2,607,738 Hardy Aug. 19, 1952 2,676,963 Rottschaefer et al. Apr. 27, 1954 2,696,306 Gomery Dec. 7, 1954 2,752,297 Kleiman June 26, 1956 FOREIGN PATENTS 44,976 Switzerland Jan. 2, 1909 553,735 Great Britain June 3, 1943 OTHER REFERENCES Chem. and Met., September 1944, page 33. Protective and Decorative Coatings, by Matielle, vol. 1, pages 485-490.

Claims (1)

1. THE MIXTURE COMPRISING A SOLID, FINELY-DIVIDED INERT, INORGANIC SILUENT, AT LEAST 10% BY WEIGHT OF A SOLID, FINELY-DIVIDED STRONG OXIDIZING AGENT SELECTED FROM THE CLASS CONSISTING OF INORGANIC HYPOCHLORITES AND N-CHLOROSUBSTITUTED COMPOUNDS AND SUFFICIENT CHLORINATED BIPHENYL CONTAINING ABOUT 48 TO 54% CHLORINE TO PROVIDE 0.5 TO 6.0% BY WEIGHT OF THE FINAL MIXTURE.