CA1202854A - Bleaching detergent composition - Google Patents

Abstract

Bleaching Detergent Composition Abstract of the Disclosure A bleaching detergent composition contains as effective component sodium percarbonate which has been coated with a coating agent containing a borate.

Description

~ZV2854 Bleaching Detergent Composition The present invention relates to a bleaching detergent having an e~cellent storage stability.
More particularly, the present invention relates to a bleaching detergent contalning sodium percarbonate having the surface coated with a borate-containing coating agent.
Sodium percarbonate has been known as a bleach-ing agent or oxidizing agent. Like sodiurn perborate, sodium percarbonate is a typical oxygen-containing bleaching agent. Generally, sodium percarbonate is produced by reacting sodium carbonate with hy~rogen peroxide and is represented by the formula:

2Na2C3'3H22 Sodium percarbonate has a bleaching power slightly lower than that of chlorine-cont~i n ing bleaching agents at ambient temperature. However, it has advantages that it does not yellow synthetic fibers, animal fibers, resin-treated fibers or fibers I~V;~8S4 treated with fluorescent brightening agents and it does not damage the fibers. Further, it exhibits sufficient bleaching effects at an elevated temper-ature or in the presence o~ a decomposition accel-erator. Therefore, sodium percarbonate has been used as a domestic or commercial bleaching agent.
Reasons why sodium percarbonate has attracted attention in the fieLd of general detergents and domestic bleaching agents are that its decomposition products ~o no-t cause environmental pollution and that it can be used practically in any manner with-out posing an~ problem.
However, sodium percarbonate has a ~ defect that its storage stability is far inferior to that of sodium perborate and available oxygen is lost rapidly during the storage. The surface of sodium percarbonate becomes wet and is decomposed in the presence of even a very low moisture, since it has a high affinity with water. Particularly when iron, copper, manganese or cobalt lon is contained therein, the decomposition is further accelerated and the stability thereof is lower than that of sodium perborate. When sodium percarbonate is stored alone in a closed vessel, its storage stability is equal to that of sodium perborate. However, when sodium 00~

percarbonate is stored in the form of a mixture with a detergent or in an open vessel, it exhibits a high hygroscopicity and low storage stability, though it has a high solubility.
Sodium tripolyphosphate (STPP) contained as a builder in detergents invites eutrophication to cause environmental pollution in a closed water area. Under these circumstances, the demand of low-phosphorus or phosphorus-free detergents has been increased. In the production of the low-phosphorus or phosphorus-free detergents, synthetic zeolites ~aluminosilicates) have become into wide use recently as a substitute for STPP.
~ owever, sodium percarbonate is quite unstable in the zeolite-containing detergent. In the zeolite-containing, phosphorus-free detergent, available oxygen of sodium percarbonate is lost rapidly by the catalytic decomposition due to the zeolite.
Therefore, it has eagerly been demanded to develop a technique capable of reducing the phos-phorus content of the detergent or dispensing with STPP and attaining a high storage stability of sodium percarbonate contained therein.
There have been proposed processes for X~{?Z8S4 stabilizing sodium percarbonate such as one wherein sodium percarbona-te is coated with paraffin or one wherein it is coated with polyethylene glycol having a molecular weight of 3000 to ~000. However, in the former process, the water solubility i5 reduced seriously and impractically. In the latter process, the long-term storage stability cannot be obtained, since polyethylene glycol per se has a considerable hygroscopicity, though the water solubility is not deteriorated.
Another process has been proposed wherein at least two stabilizers selected from the group con-sisting oE phosphoric acid compounds, silicic acid compounds, ethylenediaminetetraacetates and nitrilo-triacetates are incorporated in an aqueous hydrogen peroxide solution in the production of sodium per-carbonate. However, these stabilizers do not exhibit any practical stabilization effect when they are mixed with water or detergents, though they exhibit a stabilizing effect against te~lperature. In still another process, sodium percarbonate is uniformly coated with sodium pyrophosphate. However, this process is not satisfactory with respect to the stabilizing effect in the presence of water and detergents, though the thermal decomposition rate t3S4 is low.
An object of the present invention is to provide a bleaching detergent containing sodium percarbonate which can be stored s-tably until use even when sodium percarbonate is incorporated into a low-phosphorus or phosphorus-free detergent.
According to the present invention there is provided a bleaching detergent composition which comprises 1 to 99 percent by weight of sodium percarbonate coated on the surface with a borate-containing coating agent.
The invention provides a new composition suitable for a bleaching detergent and a bleaching agent. The composition is characterized by containing therein 1 to 99 percent by weight of sodium percarbonate coated on the surface with a borate-containing coating agent. The bleaching detergent composition preferably comprises 1 to 40 percent by weight of said coated sodium percarbonate. The bleaching composition preferably comprises 40 to 99 percent b~ weight of said coated sodium percarbonate.
The inver.-tion will be further described with reference to the accompanying drawings in which:

~Z~IZ8S4 Figure 1 is a scanning electron microscope photograph of uncoated sodium percarbonate particles, and Figure 2 is a scanning electron microscope photograph of coated sodium percarbonate particles, each at lOOX magnification. Figure 3 is an enlarged (440X magnification, photograph of a cross section of the coated sodium percarbonate particles of Figure 2, and shows a borate-coating layer on the surfaces of the particles.
The sodium carbonate of Figure 2 and 3 is coated with 3.7% of sodium metaborate dihydrate.
The percarbonate contained in the bleaching detergent according to the present invention is stabilized by coating the same with a coating agent containing a borate, preferably sodium borate, particularly sodium metaborate. The coating agent may J~urther contain a sequestering agent such as ethylenediamine-tetraacetate, nitrilotriacetate or phosphate.
The amount of the coating agent is preferably 0.1 to 30 wt.% based on sodium percarbonate. The amount of the borate in the coating agent is preferably 10 to 100 wt.%.

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It has be_n known that boric acid compounds are used as a coating~granulating agent for pero-xides to be incorporated in bleaching detergents.
For example, boric acid compounds (orthoboric, metaboric or tetraboric acid) are disclosed as coating agents for peroxides in the specification of British Patent No. 1,57S,792. In the specifl-cation of Japanese Patent Publication No. ~760/1974, it is disclosed to add metaboric acid to a hydrogen peroxide adduct to improve its storage stability.
However, these publications are silent on the coat-ing of peroxides with the borates as in the process of the present invention.
The inventors have found tha-t the borate coat-ing has a hiyh spreadability and its sodium per-carbonate-coating efficiency is quite high and that powdery or granular sodium percarbonate having the surface coated with the borate has a storage sta-bility far higher than that of sodium percarbonate coated with boric acid in a bleaching detergent.
The present invention has been attained on the basis of this finding. Electron photomicrographs show that the surfaces of sodium perborate particles are uniformly coated with the borate. This fact proves that the coating process of the present oo~
9LZ()Z8S~

inventlon is highly efficient.
As the borates used for coating sodium per-carbonate according to the present invention, sodium borates are suitable. They include sodium tetra-borate decahydrate (borax, Na20 2B203 10H2~), sodium tetraborate pentahydrate (Na20 2s203 5H20), sodium tetraborate tetrahydrate (Na20 2B203 4H20), (an-hydrous) sodium tetraborate (Na20 2s2o3)~ sodium octaborate tetrahydrate ~Na2o-4B203 4H203, sodium pen-taborate pentahydrate (Na20-5B203-10H2~), sodium metaborate tetrahydrate (NaB02 4-~20) and sodium metaborate dihydrate (~aB02-2H20). Among them, sodium metaborate dihydrate and sodium metaborate tetrahydrate are particularly preferred.
The coating agent for sodium percarbonate used in the present invention may contain various organic or inorganic compounds in combination with the sodium borates. The inorganic compounds are, for example, sodium carbonate, Glauber's salt and magnesium sulfate. The organic compounds are, for example, organic high molecular compounds such as polyethylene glycol, polyvinylpyrrolidone and hydroxypropylcellulose. The sodium borates may be used in combination with also a se~uestering agent such as a nitrilotriacetate or ethylenediamine-oo9 ~Z~Z854 tet~aacetate. The amount of the secues.erina agentis prefera~lY O.01 to 3 wt.% based on sodium per-carbonate.
Sodium percarbonate may be coated wlth the coating agent containing the borate by an ordinary coating method in the present invention. For e~.cample, a solution of the coating agent or a powder~ coating agent is mi~ed with wet or dr~
sodium percarbonate powder or granules to e,~rect uniform adsorption and the mi~ture is dried. The coated sodium percarbonate particles have an average particle diameter of 100 to 2000 ~, preferably 250 to ~C00 u.

The inventors have made studies to find out a process for the preparation of a borate-coated sodium percarbonate which can be practiced industrially easily and makes it possible to completely coat sodium per~
carbonate with a borate. As a result, we have found that the desired sodium percarhonate can be obtained by utilizing the characteristics of the borate in the coating treatment.
The most advantageous method for obtaining a surface-coated sodium percarbonate by treating its pow-der with a coating agent containing a borate according to ~he pr~sent invention comprises wetting sodium percarbonat~ with water, miclng the wetted sodium percarbonate with a powdered coating agent containing a borate to ~ake said agent to be adsorbed bv sodium percarbonate, and then drying them at a temperature not ]ower than that at which the borate begins to melt.

In the above advantageous method or the present invention, it is believed that when a powdered borate containing water or crystallization is sprinkled on sodium percarbonate in a wetted state and t~en sodium percarbonate is dried at a temperature not Lower than the melting point of the borate (for example, Na2B407-10H20: 75C, NaB0~ 4H2O: 57C, NaBO2 2H2~: ~0C
and NasO3 4H2O: 63C), the borate is dissolved itseli in '~he water of cr-~stallization and becomes molten and sodium percarbonate is completely wrapped up in the molten borate.
D~ring this stage, water in sodium percarbonate and water of crystallization in the borate are evaporated, and the drying operation is completed. Thus, uniform ~ilm formation and drying are simultaneously conducted.
Usually, sodium percarbonate can be dried at a tem-perature ranging from 40 to 160C. Drying can be ef~ected even at a temperature below 40C, but it takes too a long time to dry it. ~t a temperature above 1~0C, sodium percarbonate undergoes inefrective decomposition and su~'~ers a great loss OL- available o~ygen.

Thus it is preferred to conduct the drying at a tempe-rature of not lower than the melting point of the borate, but not higher than 160C in the present invention.
Anhydrous borates have higher melting points than those of the corresponding hydrates (e.g., Na234O7 melts at 741~C), but the melting points of anhydrous borates are lowered because of the inrluence of moisture contained in the wetted sodium rpercarbonate which be~
haves just like water of crystallization. Hence the anhydrous borates can be used in the present inve~tion, although borates containing water of crystallization are preferred. The amount of the borate in the borate-coated sodium percarbonate is 0.04 to 10~ (W/W), prererably 0.1 to 5% (r~/w) (in terms of boron) based on dry sodium percarbonate. The smaller particle size of the borate is preferred, but it is usually 50 to 300~, preierably 100 to 150,u from the viewpoint or workability.
As the wetted sodium percarbonate used for the production of the stable sodium percarbonate of the present invention, one obtained by reacting sodium carbonate with hydrogen peroxide in a conventional manner followed by dehydration in a conventional manner can be used as such. This percarbonate in a wetted state has a moisture content or 7 to 18~ Since the moisture serves as a necessary wetting water, the ~ZV~354 sodium percarbona~ can be used as such. But, sodium percarbonate having a moisture content of lO to 16%
is preferred. r~hen sodium percarbonate having a lower moisture content is used, it is preferred that sodium percarbonate is wetted with an appropria-te amount of water so that a powdered borate can be uniformly sprin~led thereon.
It is advantageous that -the coating agent of the present invention contains a conventional sta-bilizer for sodlum percarbonate, such as an ethylene-diaminetetraacetate, or a sequestering agent such as a nitrilotriacetate which does not have an adverse effect on the film formation of the molten borate.
In the preparation of the borate-coated sodium percarbonate of the present invention, sodium per-carbonate may be coated by spraying an aqueous solu-tion of a borate on sodium percarbonate powder, mixing said powder and then drying it. However, since dry sodium percarbonate must be used in this method, it is necessary to carry out the drying treatment twice.
Alternatively, sodium percarbonate may be coated by using sodium percarbonate powder wetted with water, particularly sodium percarbonate in a wetted state obtained by reacting hydrogen peroxide with sodium carbonate in an aqueous solution followed by dehydration, lZ~Z854 i.e. by mixing said sodium percarbonate in the wetted state with a powdered borate to make the borate to be adsorbed by sodium percarbonate and then drying sodium percarbonate. I'his process utilizes the characteristics of the borate and is an industrially very advantageous process which can be easily conducted with less energy consumption without a necessity of dissolving the borate.
It is observed from the attached photomicrographs that in the borate-coated sodium percarbonate obtained by the process of the present invention, the surfaces of sodium percarbonate particles are uniformly coated with the borate.
The thus coated sodium percarbonate exhibits a quite high storage stability when it is incorporated in an ordinary powdery detergent (spray-dried detergent), particularly zeolite-containing low-phosphorus or phosphorus-free detergent. l to 40 wt.~ of the obtained, coated sodium percarbonate ls incorporated in a powdery detergent to obtain the intended bleaching detergent of the present invention.
As disclosed before, the invention provides an improved bleaching agent which contains 40 to 99 percent by weight of said coated sodium percarbonate. It solves the below mentioned problems in the state of arts.

,.

~2~Z8S4 However, sodium percarbonate has a drawback of being liable to be decomposed by moisture, heavy metal salts, or the like and hence is decomposed by absorption of moisture, other ingredients incorporated in the bleaching agent composition or impurities originated in a container during an elongated storage.
As a result, -the amount of available oxygen is reduced.
However, it is necessary for sodium percarbonate for use in domestic bleaching agents that it has a long-term storage stability, does not absorb moisture after opening of a container, is not affected by various for-mulation ingredients such as bleaching activating agent, enzyme, fluorescent dye, perfume, etc. incorporated in order to improve bleaching performance and touch, nor 'nas an adverse effect on them. T~erefore, if sodium percarbonate is stabilized so as not to be affected by such other ingredients, it becomes possible to provide a high-performance domestic bleaching agent composition having good storage stability.

In a composition containing sodium percarbonate, a transition metal salt such as cobalt, iron or copper salt and a chelating agent, sodium percarbonate is rapidly decomposed by the catalytic action of the transition metal.

~ZVZ85 When the organic peracid precursor mentioned above as a second e~ample is used, both the activating agent and sodium percarbonate are decomposed by the reaction therebetween. In addition thereto, its commercial value as a domestic bleaching agent is remar'cably reduced owing to the smell or a carboxylic acid, particulary acetic acid formed by the decom-position of the activating agent.

As stated above, when both the coated sodium percarbonate and the bleaching activating agent are blended in the present invention, there are advantages in that a bleaching agent composi-tion having a high bleaching activity as well as excellent storage stability can be obtained, and it becomes possible to widely choose formulation ingredients such as per~ume.
The bleaching agent composition of the present invention contains at least 40 wt.% of the coated sodium percarbonate. The amount of the coated sodium percarbonate to be blended is 40 to 99 wt.%, pre~erably 40 to 90 wt.%. The amount OL the bleaching activating agent to be blended is 0.1 to 60 wt.%, preferably 1 to 40 wt.%.

Coated sodiu~ percarbonate used ln the pres2~t inven~on has thus an e~tre~ely improv2d s.orage staDi1it~ and, tnereLore, its in1uences on ot'ner ~Z~)2854 components contained in the detergent such as a fluorescent d~e and an enzyme which exhibit thelr efect in the washing step may be minimized. Thus, even if sodium percarbonate is incorporated in a detergent composition containing an enzyme and a fluorescent dye which are easily influenced by the decomposition of sodium percarbonate, the problem o~ the stability of the composition can be solved according to the present invention. Namely, accord ing to the present invention, a phosphorus-free detergent containing sodium percarbonate in com-bination with the enzyme and fluorescent dye in which the respective components have excellent storage stabilities can be obtained.
The bleaching detergent composition of the present invention may contaln, if desired, water-soluble soaps, anionic, nonionic or amphoteric surfactants, orsanic or inorsanic builders, seques-tering agents, bulk fillers, enzymes effective for the deterging, bleaching-activating agents, fluores-cent brightening agents and perfumes as will be described below. These additives are not particu-larly limited but used according to the purposes.
[1] Surfactants:
1) Straight-chain or branched alkylbenzene~

() 1 '7 ~Z~2854 sulfonates containing alkyl groups having 10 to 16 carbon atoms in average.

2) Alkyl or alkenyl ether sulfates containing straight-chain or branched alkvl or alkenyl group having 10 to 20 carbon atoms in average and contain-ing 0.5 to 8 mol iIl average of ethylene oxide, pro-pylene oxide or butylene oxide or two of these three compounds in an ethylene oxide/propylene oxide ratio of 0.1/9.9 to 9.9/0.1 or ethylene oxide/butylene oxide ratio of 0.1/9.9 to 9.9/0.1.

3) Alkyl or alkenyl sulfates containing an alkyl or alkenyl group having 10 to 20 carbon atoms in average.

4) Olefinsulfonates having 10 to 20 carbon atoms in average in the molecule.

5) Alkanesulfonates having 10 to 20 carbon atoms in average in the molecule.

6) Saturated or unsaturated fatty acid salts having 10 to 24 carbon atoms in average in the molecule.

7) Alkyl or alkenyl ether carboxylic acid salts containing an alkyl or alkenyl group having 10 to 20 carbon atoms in average and 0.5 to 8 mol of ethylene oxide, propylene oxide or butylene oxide or ethylene oxide/propylene oxide in a ratio of ~1~
lZ~J2854 0.1/9.9 to 9.9/0.1 or ethylene o~ide/butylene o~ide in a ratio of 0.1/9.9 to 9.9/0.1.

8) ~-Sulfofatt~ acid salts or esters of the formula:
R - C~C0 I

SO,j Z

wherein Y represents an alkyl group haviny 1 to 3 carbon atoms or a counter ion, Z re-presents a counter ion and X represents an alkyl or alkenyl group having 10 to 20 carbon atoms.
As the counter ions in the anionic surfactants, there may be men-tioned ions of alkali metals such as sodium or potassium, those of alkaline earth metals such as calcium or magnesium, ammonium ion, and those of alkanolamines containing 1 to 3 alkanol groups having 2 or 3 carbon atoms such as mono-ethanolamine, diethanolamine, triethanolamine and triisopropanolamine.

9) Amino acid-type surfactants of the general formula:
No. 1 R1 - CO- ~- CE- COO~

1'2 1~ ~

01 ~
:~Z~28S4 wherein X1 represents an alkyl or alkenyl group having 8 to 24 carbon atoms, R2 re-presents a hydrogen or an alkyl group having 1 or 2 carbon atoms, R3 represents an amino acid residue and X represents an alkali metal or an alkaline earth metal ion.
No. 2 Rl - CO- h - ~ C 2 ) n CO

Rz wherein R1, R2 and X have the same meaning as above and n represents an integer of 1 to 5.

No. 3 R
~ N- (CE2)m- COO~

wherein Rl has the same meaning as a~ove and m represents an integer of.l to 8.

_ .
No. 4 Rl - ~ - C~ - COO~

R~ R3 wherein Rl, R3 and X have the same meaning as above and R4 represents a hydrogen or an alkyl or hydroxyalkyl group having 1 or 2 carbon atoms.
No. 5 R5 - N - C~- COOg ~i ) () lZ~28S9 wherein R2, R3 and X have the same meaniny as above and R~ represents a ~-hydroxyalkyl or ~-hydro~yalkenyl group having 6 to 28 carbon atoms.

No. 6 R5 > ~--C~--COO~
~5 I, _ wherein R3, R5 and X have the same meaning as above.
lO) Phosphate ester surfactants:
No. l Alkyl~or alkenyl) acid phosphates:

(R')n~ - P- (~)~' wherein R- represents an alkyl or alXenyl group having 8 to 24 carbon atoms, n'+m'=3 and n'=1~2.
No. 2 Alkyl(or alkenyl) phosphates:

O
(R')n~- P - (0~)~"

wherein R' has the same meaning as above, n"+m"=3 and n"=1-3.

No. 3 Alkyl(or alkenyl) phosphate salts:

CR'o)_"- P ~ (O~r')~, wherein R-, n" and m" have the same meaning as above and M- represents Na, K or Ca.
11) Sulfonic acid-type amphoteric sulfactants of the general formulae:
No. 1 R

~llCON~ - R12-~ - R

wherein Rll represents an alkyl or alkenyl group having 8 to 24 carbon atoms, R12 re-presents an alkyl group having 1 to 4 carbon atoms, R13 represents an alkyl group having 1 to 5 carbon atoms and Rl~ represents an alkyl or hydroxyalkyl group haviny 1 to 4 carbon atoms.
No. 2 R15 Rll--N --Rl~--S O

wherein Rll and R14 have the same meaning as above and R15 and R16 represent an alkyl or alkenyl group having 8 to 24 or 1 to 5 carbon atoms.

02 ' ~ZOZ854 No. 3 CC2H~O)n1~

R~ - Rl,~- SO3 (C2H~O) nl~

wherein Rll and R14 have the same meaning as above and nl represents an integer of 1 to 20.
12) Betaine-type amphoteric surfactants of the general formulae:
No. 1 R22 R - ~- R2j- COO~

wherein R21 represents an alkyl, alkenyl, ~-hydroxyalkyl or 3-hydroxyalkenyl group having 8 to 24 carbon atoms, R22 represents an alkyl group having 1 to 4 carbon atoms and R23 represents an alkyl or hydroxyalkyl group having 1 to 6 carbon atoms.
No. 2 (C2H4)n2~

~21 - ~ - R23 - COO
( C2Fr4 O)n2E

wherein R21 and R23 have the same meaning as above and n2 represents an integer of 1 to 20.

~Z~Z854 No. 3 R2~

R2 ~ R2 3 C O O
~2~

wherein R2l and R23 have t'ne same meaniny as above and R24 represents a carboxyalkyl or hydroxyalkyl group having 2 to 5 carbon atoms.
13) Polyoxyethylene alkyl or alkenyl ethers containing an alkyl or alkenyl group having lO to 20 carbon atoms in average and l to 20 mol of ethylene oxide.
14) Polyoxyethylene alkylphenyl ethers con-taining an alkyl yroup haviny 6 to 12 carbon atoms in average and l to 20 mol or ethylene oxide.
15) Polyoxypropylene alkyl or alkenyl ethe~s containing an alkyl or alkenyl group having lO to 20 carbon atoms in average and l to 20 mol of pro-pylene oxide.
16) Polyoxybutylene alkyl or alkenyl ethers containing an alkyl or alkenyl group having lO to 20 carbon atoms in average and l to 20 mol of butylene oxide.
17) Nonionic surfactants containing an alkyl or alkenyl group having lO to 20 carbon atoms in average and l to 30 mol, in total, of ethylene lZV'~854 oxide and propylene oxide or etnylene oxide and butylene oxide (the ratio of ethylene oxide to propylene oxide or butylene oxide is 0.1/9.9 to 9 . 9/0 . 1) .
18) Higher fatty acid alkanolamides or their alkylene oxide adducts of the following formula:

R' CCHCH 0) E
RllC0~ < 2 n~
(C C~zO~m3E
Rlz wherein Rll represents an alkyl or alkenyl group having 10 to 20 carbon atoms, R12 represents H or C~3, n3 represents an integer of 1 to 3 and m3 represents an integer of 19) Sucrose/fatty acid esters comprising a fatty acid having 10 to 20 carbon atoms in average and sucrose.
20) Fatty acid/glycerol monoesters comprising a fatty acid having 10 to 20 carbon atoms in average and glycerol.
21) Alkylamine oxides of the general formula:

~)~5 R~
R~ ~ O

wherein R13 represents an alkyl or alkenyl group having 10 to 20 carbon atoms and Ri4 and Ri5 represent an alkyl group having 1 to 3 carbon atoms.
22) Cationic surfactants of the general formulae:
No. 1 R2 Rl - N R~ ~' R' wherein at least one of Rl, R2, R3 and R4 represents an alkyl or alkenyl group having 8 to 24 carbon atoms and others represent an alkyl group having 1 to 5 carbon atoms and X~ represents a halogen.
No. 2 Rl I C~I2 C 6 ~ 5 R' ~ZOZ8S~

wherein Rl, R2, R3 and X~ have the same meaning as above.
No. 3 (R5O)~E
R ~ R 2 g ' I

~ (R5O)n E

wherein Rl, R2 and X' have the same me~ning as above, R- represents an alkylene group having 2 or 3 carbon atoms and n4 represents an integer of 1 to 20.
It is desirable that the composition contains at least 10 wt.~ of one or more of the above-men-tioned surfactants.
[2] Sequestering agent:
The composition may contain 0 to 50 wt.% of one or more builders selected from the group con-sisting of alkali metal salts and alkanolamine salts of the following compounds:
1) Salts of phosphoric acids such as ortho-phosphoric, pyrophosphoric, tripolyphosphoric, metaphosphoric, hexametaphosphoric or phytic acid.
2) Salts of phosphonic acids such as ethane-l,l-diphosphonic, ethane-1,2-triphosphonic, or ethane-l-hydroxy-l,l-diphosphonic acid and l)2( lZ~ 354 derivatives thereof, ethane-hydroxy-1,1,2-triphos-phonic, ethane-1,2-dicarboxy-1,2-diphosphonic, or methane-hydro~yphosphonic acid.
3) Salts of phosphonocarboxylic acids such as 2-phosphonobutane-1,2-dicarbo~ylic, l-phos-phonobutane-2,3,4-tricarbo~ylic or ~-methylphos-phonosuccinic acid.
4) Salts of amino acids such as aspartic or glutamic acid.
5) Salts of arninopolyacetic acids such as nitrilotriacetic, ethylenediaminetetraacetic or diethylenetriaminepentaacetic acid.
6) High-molecular electrolytes such as poly-acrylic acid, polyaconitic acid, polyitacon:Lc acid, polycitraconic acid, polyfumaric acid, polymaleic acid, polymesaconic acid, poly-~-hydroxyacry]ic acid, polyvinylphosphonic acid, sulfonated poly-maleic acid, maleic anhydride/diisobutylene copoly-mer, maleic anhydride/styrene copolymer, ma:Leic anhydride/methyl vinyl ether copolymer, maleic anhydride/ethylene copolymer, maleic anhydride/
ethylene cross-linked copolymer, maleic anhydride/
vinyl acetate copolymer, maleic anhydride/acrylo-nitrile copolymer, maleic anhydride/acrylate copolymer, maleic anhydride/bu-tadiene copolymer, ~8 ~O~S4 maleic anhydride/isoprene copolymer, pol~ keto-carboxylic acid deri..ved from maleic anhydride and carbon monoxide, itaconic acid/ethylene copolymer, itaconic acid/aconitic acid copolymer, itaconic acid/maleic acid copolymer, itaconic acid/acrylic acid copolymer, malonic acid/methylene copolymer, mesaconic acid/fumaric acid copolymer, ethylene glycol/ethylene terephthalate copolymer, vinyl-pyrrolidone/vinyl acetate copolymer, l-butene-2,-3,4-tricarboxylic acid/itaconic acid/acrylic acid copolymer, polyester polyaldehyde carboxylic acid containing a quaternary ammonium group, cis-isomer of epoxysuccinic acid, poly[N,N-bis(carboxymethyl)-acrylamide], poly(oxycarboxylic acids), starch succinate, maleate or terephthalate, starch phos-phate, dicarboxystarch, dicarboxymethylstarch or cellulose succinate~
7J Non-dissociating high molecules such as polyethylene glycol, polyvinyl alcohol, polyvinyl-pyrrolidone or cold water-soluble, urethanized polyvinyl alcohol~
8) Salts of organic acids such as diglycolic, hydroxydiglycolic, carboxymethyloxysuccinic, cyclopentane-1,2,3,4-tetracarboxylic, tetrahydro-furane-1,2,3,4-tetracarboxylic, tetrahydrofurane-U~9 )2854 2,2,5,5-tetracarbo.Yylic, citric, lactic or tartaric acid, carboxymethylated products of sucrose, lactose or raffinose, carboxymethylated pentaerythritol, carboxymethylated gluconic acid, condensates of polyhydrlc alcohols or sugars with maleic or succinic anhydride, condensates of hydroxycarboxylic acids with maleic or succinic anhydride, benzenepolycarbo-xylic acids such as mellitic acid, ethane-1,1,2,2-tetracarboxylic, ethene-1,1,2,2-tetracarboxylic, butane-1,2,3,4-tetracarboxylic, propane-1,2,3-tricarboxylic, butane-1,4-dicarboxylic, oxalic, sulfosuccinic, decane-1,10-dicarboxylic, sulfotri-carbollylic, sulfoitaconic, malic, hydroxydisuccinic or gluconic acid, CMOS or builder M.
9) Aluminosilicates:
No. 1 Crystalline aluminosilicates of the formula:

~'(MzO or ~"O)- ~ O~-y'(SiOz) w'(~O) wherein M- represents an alkali metal atom, M" represents an alkaline earth metal atom exchangeable with calcium and x , y and w' represent each a molar number of the respec-tive components and generally, 0.7'x'_1.5, 0.8_y''6 and w~ being any positive number.

l)~o ~S4 No. 2 As the detergent ~uilders, -those of the foLlowing general formula are particularly preferred:

~a2o ~2o~ rlsio2 w 2 wherein n represents a nur~er of 1.8 to 3.0 and _ represents a number of 1 to 6.
No. 3 Amorphous aluminosilicates of the formula:

~(~2o)-A~2o3-y(sio2~ 2o) wherein M represents a sodium and/or potassium atom and _, y and w represent each a molar_ number of the respective components within the following ranges:
0.7<x~1.2 1.6_y'2.8 w being any positive number including 0.
No. 4 Amorphous aluminosilicates of the formula:

~C~2~ ~203~Y(s1 2)-Z(P2os)-~(~2o) wherein M represents Na or K and X, Y, Z and represent each a molar number of the respec-tive components within the following ranges:

~1 ~2~ 5 0.20''~ 1.10 0.20=~- .00 0.001~Z~0.~0 ~ being any positi~e numDer including 0.
[3~ Alkalis and inorganic electrolytes:
Further, one or more or alkali metal salts shown below may be contained in t'ne composition in an amount of 1 to 50 wt.~, preferabl~ 5 to 30 wt.~, as alkalis or inorganic electrolytes: silicat-s, carbonates and sul~ates. Organic alkalis include, for example, triethanolamine, diethanolamine, mono-ethanolamine ana triisopropanolamine.
The following explains in detail incorporation of an alkali metal silicate into the coating agent.

As to the coating of sodium percarbonate which is an indispensable step for improving its storage stability, the mechanical strength of the coating is remarkably improved when a borate is used in combination with an alkali metal silicate. Thus, there is no fear of damaging the coating during the course of handling, particularly until the stage of blending with powdered detergents.

~ZOZ854 Suitable alkali metal silicates are those of the formula Na2O nSiO2, wherein n represents a molar rat;o of SiO2/Na2O, and is 0.5 to 4. Examples of such alkali metal silicates are an aqueous solution of a crystalline sodium silicate such as sodium orthosilicate (2Na2O SiO2 xH2O, n = 0.5), sodium sesquisilicate (3Na2O 25iO2 xH2O, n = 0.67), and sodium metasilicate (Na2O-SiO2 xH2O, n = 1), an aqueous solution of an amorphous sodium silicate such as Na2O nSiO2 (n = 1 - 4) and dehydrated sodium silicate powder thereof.

The so-coated sodium percarbonate exhibits an excellent storage sta~ility even when incorporated in conventional powdered detergents (spray-dried products), particularly low-phosphorus or phosphorus-free detergents containing zeolite blended thereof. Further, in addition to a synergistic coating effect obtained by using the borate and the alkall metal silicate in com-bination, the strength of particles and the coating is improved by the use of the alkali metal silica-te without deteriorating the solubility of sodium per-carbonate. Thus, there is no ~ear of damaging the coat-ing during stages until sodium percarbonate is blended with powdered detergents.

12~Z85~

[~] Antiredeposition agents:
The composition mav contain 0.1 to 5% or one or more Oc the followinq compounds as antiredeposi-tion agents: polyethylene glycol, pol~yvinyl alcohol, polyvinylpvrrolidone and carboxymethyl cellulose.
[5] Fluorescent dyes:
Fluorescent dyes represented by, for e.xample, t'ne i-ollowing structural ror~ulae (w), (x) and (y) may also be contained in the composition:

~34 ~Z~Z854 ~NE--~ ~ N~ C H
N~N
~N~ S O Na C ~ (W) SO~a ~ ~

C~I = CE~ C~= CE~ (~) S03 ~a SO~ ~a ~¢ N~C~I=C13:~ N ~ O

H
S 0~; Na S O j Na [6] Enzymes (those exhibiting their essential enzymatic effects in the deterging step):
In respect of reactivity, enzymes may be classified into groups of hydrolases, hydrases, oxidoreductases, desmolases, transferases and isomerases. Among them, hydrolases are particu-larly preferred. They include protease, esterase, carbohydrase and nuclease.
Particular examples of proteases are pepsin, ~i ~) s 12~Z~S4 trypsin, chymotrypsin, collagenase, keratinase, elastase, su~tilisin, BPN, papain, bromelin, carbo.~ypeptidases A and B, aminopeptidase, and aspergillopeptidases A and B.
Particular ecamples of esterases are gastric lipase, pancreatic lipase, vegetable lipases, phospholipases, cholinesterases and phosphatases.
As the carbohydrases, there may be mentioned, for e~ample, cellulase, maltase, saccharase, amylase, pectinase, lysozyme, ~-glycosidase and ~-glycosidase.

The coated sodium percarbonate according to the invention exists stably together with an enzyme in the compostion. The stability of the composition which comprises said coated sodium percarbonate and an enzyme is further improved by incorporating therein a synthetic zeolite in an amount of not less than 5 percent by weight. Such composition practically comprises SO to 99 percent by weight of said coated sodium percarbonate and 0.1 to 10 percent by weight, as protease of 2.0 Anson uni-t per gram, and from 5 to 100 percent by weight, based on the weight of said coated sodium percarbonate, of a zeolite. The Anson unit is e~plained in Anson, M.L., Journal o~
General Physiolosy, vol. 22(1939), pages 79 to 89.

~);3t) 12~28S4 [7J Blueing agents:
Various blueing agents may be incorporated in the composition, if necessary. Blueing agents oE, for e~ample, the following structure are recon~ended:

~ N~
Il, I
~ C ~ ----(S03E)n wherein D represents blue or purple monoazo, disazo or anthraquinone dyestuff residue, X
and Y represent each a hydro~yl group, amino group, aLiphatic amino group which may be substituted with a hydro~yl, sulfonic acid, lZ~8S4 carboxylic acid or alkoxyl group, or an aromatic amino or alicyclic amino group which may be substituted with a halogen atom or hydroxyl, sulfonic acid, carboxylic acid, lower alkyl or lower alkoxyl group and R
represents a hydrogen atom or a lower alkyl group excluding a case in which R represents a hydrogen atom and (1) both X and Y repre-sent hydroxyl or alkanolamino groups at the same time or (2) one of X and Y represents a hydroxyl group and the other represents an alkanolamino group, and n represents an integer of at least 2, and D - N~ - C C -,11 1 : ~ N
~ C ~

wherein D represents a blue or purple azo or anthraquinone dyestuff residue and X and Y
represent the same or different alkanolamino residue or hydroxyl group.
~8] Caking inhibitors:
The following caking inhibitors may also be IZ~Z854 con~ained in the composition: p-toluenesulfonates, xylenesulfonates, acetates, sulfosuccinates, talc, finely pulverized silica, clay, calcium silicate (such as Micro-cells of Johns-L~anvill Co.), calcium carbonate or magnesium oxlde.
[9] Antioxidants:
The antioxidants include, for example, tert-butylhydroxytoluene, 4,4'-butylidenebis(6-tert-butyl-3-methylphenol), 2,2'-butylidenebis(6-tert-butyl-4-methylphenol), monostyrenated cresol, distyrenated cresol, monostyrenated phenol, di-styrenated phenol and l,l'-bis-(4-hydroxyphenyl)-cyclohexane.
~10] Bleaching activating agents:
The bleaching activating agents are compounds which form organic peracids in the presence of peroxy compounds in an aqueous alkali solution.
They may be classified into the following three groups:
1) organic acid anhydrides, 2) ester compounds, and 3) N-acyl compounds.
As particular examples of the bleaching activating compounds, there may be mentioned tri-acetyl cyanurate (TACA), sodium p-acetoxybenzene-u ~ ~l ~Z~2854 sulfonate (SABS), tetraacetylglycouryl (TAGU)acetylsalicylic acid, N-acetylimidazole (AID~, N,N,N',N'-tetraacetylethylenediamine (T.~ED) and pentaacetyl-~-D-glucose.
[11~ Stabilizers for peroxldes:
They include, for example, magnesium sllicate, magnesium sulfate, magnesium oxide and magnesium chloride.

Accordingly, sodium percarbonate to be incorporated in the bleaching detergent of the present invention can be stabilized by coating it wi-th a coating agent con-taining a borate and a magnesium compound. As the borates, sodium borate is preferred, and sodium metaborate is particularly preferred. As the magnesium compounds, preferably one or more members selected from the group consisting of magnesium chloride, magnesium oxide, mag-nesium sulfate and magnesium silicate are used.
Further, the coating agent may contain a sequestering agent such as an ethylenediaminetetraacetate or a nitrilotriacetate.
Sodium percarbonate is used in an amount of preferably 0.1 to 30 wt.% based on the amount of the coating agent. The borate is used in an amount of preferably 10 to 95 wt.%, and the magnesium compound is used in an amount of preferably 5 to 70 wt.% based on u4ù
~2~2~S4 the amount of the coatlng agent. Generally, it is preferred to use the magnesium compound in an amount not more than that of the borate.

On the contrary, the inventors have made further studies and found that when a borate and a magnesium compound are used in combination, a coated sodlum percarbonate having more excellent storage stability can be obtained by -the synergistic effect of the coating power of the borate and the stabili~ing power of the magnesium compound, and that when this coated sodium percarbonate is incorporated in powdered detergents, bleaching detergents having remarkably excellent storage stability can be obtained. The present invention is based on these findings.
Examples of magnesium compounds include magnesium sulfate, magnesium chloride, magnesium oxide, magnesium hydroxide, magnesium silica-te, magnesium nitrate, magnesium phosphate and magnesium carbonate in an anhydrous form or in a hydrated form, and magnesium salts of various organic acids. Among these, magnesium sul-fate, magnesium chloride, magnesium oxide and magnesium silicate in an anhydrous form or in a hydrated form are particularly preferred.

~2~Z8S4 The followinq examples are provided to illustrate the coated sodium percarbonate according to the invention.

Example 1 Wetted sodiurn percarbonate having a moisture content of 10% and a dry average particle size of 480~ obtained by a reaction between hydrogen peroxide and sodium carbonate in an aqueous solution, was fed to a continuous mixer at a rate of 5.3 kg/min by means of a continuous feeder. Sodium metaborate dihydrate having an average particle si~e of 150~
was also fed to the this mixer at a rate of 0.178 kg/min by means of a continuous feeder. The feed rate was adjusted so as to give a residence time of 5 min in the mixer. The mixture was continuously supplied to a fluidized dryer to dry it at 130C.
The amount of boron in the coated sodium per-carbonate was determined to be 0.42~ in terms of boron. The coated sodium percarbonate was mixed with ~arious second components and the stability of the mixtures was measured. The results are given in Table 1. The stability was expressed by avaivable oxygen residue obtained after a required amount of a sample was charged in a resin vessel provided with pinholes and left to stand at `50C and 80% RH for 24 hours.

IZ~854 TabLe 1 Uncoated PC Coated PC Second component Stability (amount: %)(amount: %) ~amount: %) (~) coated PC zeolite A-4 88.8 ' (90) (10) uncoated PC zeolite A-4 32.5 ' (90) (10) coated PC sodium metasilicate 45~6 (9~) (10) uncoated PC sodium metasilicate 32.0 . ~90) (10) coated PC acid sodium pyro- 98.2 (50) phosphate . (50) uncoated PC acid sodium pyro- 90.2 (50) phosphate (50) coated PC sodium tripolyphosphate 8 (50) (wet process) (50) 93' uncoated PC sodium tripolyphosphate (50) (wet process) (50) 82.8 Note: PC means sodium percarbonate.

Example 2 3.4g of wetted sodium percarbonate having a moisture content of 12% and a dry average particle size of 400~
and O.lkg of sodium borate decahydrate were charged in a batch mixer, and mixed together for one min.

~Z~Z8S4 The mixture was dried in a fluidized dryer at 160C.
The amount of boron in the coated sodium percarbonate was determined to be 0.40~ in terms of boron.
For the purpose of comparison, the above pro-cedure was repeated with the exception that 0.16Kg of sodium carbonate, 0.78Kg of colloidal silica (SiO2 content of 20~) and 0.31Kg of No. 3 sodium silcate were used as coating agents in place of sodium borate decahydrate. The resulting coated sodium percarbonate was mixed with a commercially available deterg~nt A
(a phosphorus-free detergent containing zeolite blended therewith) in a mixing ratio of 9:1 in a resin vessel provided with pinholes, and left to stand at 40C and 80% RH for two weeks. Thereafter, available oxygen residue (stability) was measured. The results are given in Table 2.
Table 2 Coating agent Stability (%) Present sodium borate decahydrate 92.4 invention Comparative sodium carbonate 55.7 example colloidal silica 74.0 No. 3 sodium silicate 70.0 uncoated 44.6 ~Z~;~54 Example 3 The coated PC's prepared in Examples 1 and 2 were subjected to a storage stability test under the follow-ing conditions:
(1) 10 wt.~ of the coated PC was mixed with a com-mercially available detergent B (a phosphorus-free detergent containing zeolite) (2) 10 wt.~ of the coated PC was mixed with a com-mercially available detergent C (a phosphorus-containing detergent containing sodium tripoly-phosphate).
lOg of each of the above mixtures was charged in a 50 cc plastic vessel. The vessel was closed and left to stand at 40C and 80% RH for 14 days.
Thereafter, available oxygen residue was determined according to the following equation:
available oxygen residue (~) = available oxygen after storage x 100 available oxygen be~ore storage The available oxygen was measured accordinq to a O.lN potassium permanganate titration method.
For the purpose of comparison, ~1) uncoated PC
obtained by drying wetted PC as such and (2) sodium perborate (PB) in addition to the coated PC of the present invention were also tested.

()45 ~20~S~

PC coated with PC coated with Uncoated NaBO2-2H2O NaB2O lOH2O PC PB
Commercially available (phosphorus-free, 90.1 88.0 30.7 91.0 and containing zeolite~
Commercially ava.ilable detergent C 94.5 , 92.0 90.3 94.9 (containing phosphorus and sodium tripolyphosphate) O d~ 6 lZ~);~154 sulfonate (SABS), triacetylglycouryl (TAGU), acetylsalicylic acid, N-acetylimidazole (AID), N,N,N',N'-tetraacetylethylenediamine (TAED) and pentaacetyl-~-D-glucose~
[11] Stabilizers for peroxides:
They include, for example, magnesium silicate, magnesium sulfate, magnesium oxide and magnesium chloride.
The following examples will further illustrate the bleaching detergent composition~

Example 4 100 g of sodium percarbonate was charged in a stirring type-mixer. A 25% aqueous solution of 5 g of sodium metaborate tetrahydrate (NaBO2 4H2O) (prepared by dissolving under heating) was sprayed thereon under stirring at 250 rpm. After stirring for 10 min, the mixture was dried with hot air to obtain coated sodium percarbonate.
For comparison, sodium percarbonate coated with boric acid (2.4 g of boric acid per 100 g of sodium percarbonate) was also prepared.

10 wt.% of the coated sodium percarbonate was homogeneously mixed in a phosphorus-free powdery detergent of the following composition to obtain a ~4'~
1~2854 bleaching detergent according to the present inven-tion:
Phosphorus-free bleaching detergent composi~ion (the present invention):
wt.%
sodium dodecylbenzenesulfonate 20.0 synthetic zeolite (type 4A~ 20.0 sodium silicate (JIS No. 2) 10.0 sodium carbonate 5.0 fluorescent dye 0.5 sodium salt of carboxymethylcellulose 1.0 enzyme (alcalase) 0.3 sodium percarbonate (coated with sodium metaborate according to the invention) 10.0 water 5 0 sodium sulfate balance Total 100 Three samples of the above composition con-taining sodium percarbonate coated with sodium metaborate according to the present invention, sodium percarbonate coated with boric acid for comparison and sodium percarbonate having no coat-ing were subjected to storage stability tests in thesame way in Example 3. The results are shown in Table 1.

12~Z~S4 Table 3 Coating of Available sodium oxygen percarbonate residue ~) 5~ sodium Bl.eaching detergent metaborate 75.3 of the invention (NaB02-4H20) Comparative 2.4~ boric~51 2 Example 1 . id (H BO ) Comparative none 31.1 Example 2 *coating rate of NaB02: 2.4~.

It is apparent from Table 3 that the coating effects of sodium metaborate in the bleaching detergent of the present invention were far superior o~9 ~2~28S4 to those of boric acid coating.
The bleaching deteryent in this example was an absolutely phosphorus-free detergent containing zeolite. However, it had a high stability due to the sodium metaborate coating.
Example 5 Sodium percarbonate was coated with a combina-tion of sodium metaborate with another coating agent in the same way as in Example 4. The coating agents used are sh~n belcw. ~mounts of the coating agents are shown by wt. %
based on sodium percarbonate.
(1) 5% sodium metaborate (NaB02 ~H20) + 5%
polyethylene glycol (PEG, molecular weight:
6000), (2) 5% sodium metaborate + 5% sodium carbonate, (3) 5% sodium metaborate + 0.5% disodium ethylene i diaminetetraacetate (EDTA), (4) 5% sodium metaborate + 0.5% EDTA-di-triethanol-amine salt, and (5) 5% sodium metaborate + 0.5% trisodium nitrilo-triacetate (NTA).
Six samples ti-e-, the above-mentioned five samples of coated sodium percarbonate and non-coated sodium percarbonate) were incorporated in the same phosphorus-free bleaching detergent as in Example 4 ~50 12~Z854 (amount of sodium percarbonate: 10 wt.%). The resulting compositions were subje~ted to the same storage stability test as in Example 4 to obtain the results shown in Table 4.

Table 4 Coating of sodium percarbonate AVraesiadle o(%X)yg n NaB02~4H20 + PEF 82.3 5% 5%

NaB02 4H20 + Na2C03 77.7 5% 5%

NaB02 4H20 + EDTA-2Na 83.0 5~ 0.5%

NaB02-4H20 ~ EDTA 2TEA* 86.6 5% 0.5%

NaB02 4H20 + NTA~3Na : 84.4 5% 0.5%
not coated 30.5 *EDTA di-triethanolamine salt.

It is apparent from Table 4 that when sodium metaborate was used in combination with another coating agent, a quite excellent storage stability was obtained. Particularly when sodium metaborate was used in combination with an organic high mole-cular compound such as PEG or sequestering agent ~Z~Z~354 such as EDTA or NTA, a synergism was attained to improve the storage stability.
Example 6 The solubilities, compression strengths and disintegrating properties of the coated sodium percarbonates prepared in Example 5 were examined to obtain the results shown in Table 5.
[Test methods]
Solubility 1 Q of city water was charged in a 1 Q beaker.
1 g of granular sodium percarbonate was add~d thereto and the mixture was stirred at 200 rpm.
A time required until electric conductivity of the solution became constant after the initiation of the stirring was measured and shown as dissolution time.
Compression strength:
A load was applied to a given amount of a sample under given conditions by means of an auto-graphic recording device and the load required for 1 cm compression was determined.
Disintegrating properties:
100 g of a sample which passed through a 12-mesh sieve but did not pass through an 80-mesh sieve was charged in a 500 mQ wide-mouth bottle 05~
~Z[)Z854 made of a polymer. S0 g of stainless steel balls (3~) were charged therein and a stopper was applied to the bottle. The bottle was fixed on an agitating device and agitated at 360 rpm for 10 min (ampli-tude: 4.5 cm). The disintegrating properties were expressed by the amount (wt.%) of the sample passed through the 80-mesh sieve. The smaller the amount (%), the better.

Table 5 Solubilit Compression Disintegrating Coating of sodium percarbonate Y strength properties (sec)(kg/cm2) (~) NaBO ~4H O + PEG
2 2 96 20.3 13.0 5% 5%

NaBO2-4H2O + NaCO3 111 18.8 15.8 ~% 5%
NaBO2-4H2O + EDTA-2Na 93 21.0 13.8 5% ~.5% ~ O
NaB024H20 + EDTA 2TEA 92 20.8 13.9 NaBO2-4H2O + NTA-3Na 95 20.8 14.2 5% 0.5%
not coated 90 20.6 13.4 (~54 It is apparent from Table 5 that the solubility, compression strength and disintegrating property of the sodium percarbonate were substantially un-changed by coating the same according to the process of the present invention.
Example 7 20 kg of wet sodium percarbonate was charged in a centrifugal diffusion type mixer ( mixer, FKM-130 D, T.M. Engineering Co., Ltd.).
A powdery coating agent was added thereto under stirring and they were mixed for 10 min in total.
Then, the coated sodium percarbonate was taken out and dried with hot air.
The coating agents used were as follows:
(1) 5% sodium metaborate (NaBO2 4H2O) + 0.5%
EDTA-2TEA, (2) 4.54% borax (Na2B4O7-10H2o) + 0.5% EDTA-2TEA, and (3) 2.4% boric acid (H3BO3) + 0.5% EDTA 2TEA
(The percentages are given by weight based on sodium percarbonate) The three samples (i.e., two samples of coated sodium percarbonate according to the present inven-tion and one comparative sample) and uncoated sodium percarbonate were incorporated in an amount o~

(~55 ~Z()Z8S4 10 wt.~ in the following phosphorus-free bleaching detergent composition in the same manner as in Example 4 and 5 . The results of the storage stability tests carried out in the same manner as in Example 4 sre shown in Table 6. Residual activ-ity of an enzyme (2.0 M alcalase) incorporated in the same manner as above was also determined.
Enzymatic activity residue was determined according to the following formula and also shown in Table 6:
enzymatic activity residue (~) enzymatic activity after storage x 100 enzymatic activity before storage The method of measuring the residual activity of enzyme is described in J.B.C. 244 (4), pp. 789-793 (1969) and Analyst 96, pp. 159-163 (1971).
Phosphorus-free bleaching detergent composition:
wt.%
sodium dodecylbenzenesulfonate 20.0 synthetic zeolite (type 4A) - 20.0 sodium silicate (JIS No. 2) 10.0 sodium carbonate 5.0 fluorescent dye 0.5 sodium salt of carboxymethylcellulose 1.0 enzyme (2.0 M alcalase) - 0.3 sodium percarbonate (coated) 10.0 ~Zi~Z8S~

water 5.0 sodium sulfate balance Total 100 Table 6 Available ~nzymatic Coating of sodium percarbonate oxygen activity residue (%) residue (~) NaBO2~4H2O + EDTA-2TEA 90.1 95.4 5%* 0.5 2B47-1H2 + EDTA-2TEA 88.2 94.4 4.54%* 0.5%

H3BO3 + EDTA-2TEA 73.8 90.2 2.4% 0.5%
not coated 32.0 80.3 *Coating rate of anhydrous coating agent: 2.4% .

It is apparent from Table 6 that in the phos-phorus~free bleaching deteryents ~1) and ~2) according to the present invention, stability of sodium percarbonate was extremely high and stability of the en~yme was also excellent, though they con-tained zeolite.
.xample 8 10 wt.% of the coated sodium percarbonate of the present invention prepared in Exa~ple 7 ~sodium ~2()2~S4 percarbonate coated with NaBO2-4H2O or Na2B4H7-lOH2O) or one of the two comparative samples (sodium percarbonate coated with H3sO3 or uncoated sodium percarbonate) was incorporated in a powdery bleaching detergent of the following composition.
They were subjected to the storage stability test to examine available oxygen residue in sodium per-carbonate and enzymatic activity residue (2.0 M
alcalase). The results are shown in Table 5.
The test method was the same as in Example 4 and 7.

Bleaching deter~ent composition:
wt.%
sodium dodecylbenzenesulfonate 20.0 sodium tripolyphosphate 18.0 sodium silicate (JIS No. 2)10.0 sodium carbonate 5.0 Eluorescent dye 0.5 sodium salt of carboxymethylcellulose 0.5 enzyme (2.0 M alcalase) 0.3 sodium percarbonate 10.0 water sodium sulfate balance Total 100 ~2V28S~

Total 7 A~ailable Enzymatic Coating of sodium percarbonate oxygen ac-tivity residue (~) residue (%) NaB02 4~20 + EDTA~2TEA95.8 84.8 5% 0.5%

2B47~1H2 + EDTA~2TEA 96.0 85.0 5% 0.5%

83B03 + EDTA~2TEA 90.2 80.4 5~ 0.5%
not coated 88.8 60.5 The bleaching detergent composition in this example con-tained STPP as in the conventional detergent compositions. Samples (1) and (2) accord-ing to the present invention exhibited quite excel-lent storage stabilities. This fact indicates that the bleaching detergents of the present invention have a quite high storage stability irrespective of the presence or absence of zeolite.

0 5 '~ ~ 13 lZ~)2854 Example 9 lO0 g of sodium percarbonate was charged in an agitating mixer. A 25% aqueous solution of 5 g of sodium m~taborate (Na2BO2 4H2O~ (prepared by dis-solving the metaborate in water with heating) and a 25% aqueous solution of l g (on a solid base) of sodium silicate (JIS No. 3) (Na2O 3SiO2 aq) were sprayed thereon with stirring at 250 r.p.m. After stirring for lO min, sodium percarbonate was dried with hot air to obtain coated sodium percarbonate.
For the purpose of comparison, sodium percarbo-nate coated with only sodium metaborate (7.l g of Na2BO2 4H2O per lO0 g of sodium percarbonate), sodium percarbonate coated with boric acid (3.4 g of boric acid per lO0 g of sodium percarbonate), sodium percarbonate coated with boric acid and sodium silicate (JIS No. 3) (2.4 g of boric acid and l g (on a solid basis) of JIS No. 3 sodium silicate per lO0 g of sodium carbonate), and sodium percarbonate coated with only the silicate (3.4 g (on a solid basis) of JIS No. 3 sodium silicate per lO0 g of sodium percarbonate) were also prepared.
lO wt.~ of each of these coated sodium per-carbonates was uniformly incorporated in a powdered phosphorus-free detergent having the following com-position to obtain a bleaching detergent:

phosphorus-free bleaching detergent composition wt.~

sodium dodecylbenzenesulfonate 20.0 synthetic zeolite (type 4A) 20.0 sodium silicate (JIS ~o. 2) 10.0 sodium carbonate 5.0 fluorescent dye O.S
sodium salt of carboxymethylcellulose 1.0 enzyme talcalase) 0.3 sodium percarbonate 10.0 water 5.0 sodium sulfate balance Total 100 Six samples of the above compositions contain-ing, as sodium percarbonate to be incorporated, one coated with sodium metaborate and sodium silicate according to the present invention, one coated with only sodium metaborate, one coated with boric acid, one coated with boric acid and sodium silicate, one coated with only sodium silicate and uncoated sodium percarbonate for the purpose of comparison were subjected to a storage stability test. The results are gi~en in Table 8.

Table 8 . * Available oxygen Coating of sodlum percarbonate residue (%) Bleaching detergent of 5% sodium metaborate (NaBO2-4H2O) 85.4 the present invention 1% sodium silicate (JIS No. 3) Comparative Example 3 7.1% sodium metaborate (NaBO2-4H2O) 79.7 Comparative Example 4 3.4% boric acid (H3BO3) 60.8 r 2.4% boric acid (H3BO3) ~
Comparative Example 5 1% sodium silicate (JIS No. 3~ 63.3 O

Comparative Example 6 3.4% sodium silicate (JIS No. 3) 45.3 Comparative Example 7 none * The amount (coating ratio) of the coating agent was 3.4% ~on a water-free basis) based on sodium percarbonate in all cases.

~202854 It is apparent that the available oxygen residue of the bleaching detergent containing sodium percarbonate coated with sodium metaborate and sodium silicate of the present invention, is higher than those of the bleaching detergents of Compara-tive Examples 3 to 7, and the bleaching detergent of the present invention is superior in the coating effect to those of Comparative Examples.
The bleaching detergent used in this example does not contain phosphorus at all and is a phos-phorus-free detergent containing zeolite blended therewith. sut the bleaching detergent according to the present invention exhibits a good stability because of an excellent coating effect due to sodium metaborate and sodium silicate.
Example 10 The solubility, compression strength and dis-integrating property of the coated sodium percarbo-nates prepared in Example 9 were examined. The results are given in Table 9.

Table g Coating of sodium Solubilit Compression Disintegrating percarbonate* (sec) ~kg/cm2)property Bleaching detergent 5% NaBO ~H O 98 19.5 6.2 of the present 1% sodium silicate**
invention Comparative 7 1% NaBO 4H O 96 20.7 13.9 Example 3 2 2 Comparative 3 4% boric acid (H BO ) 95 21.0 14.4 Example 4 3 3 0 c~
Comparative 2.4~ boric acid 96 l9.6 7.7 `~
1% sodium silicate Comparative Example 6 3.4% sodium silicate109 19.4 8.2 Comparative none 90 20.6 13.4 * The amount (on a water-free solid basis) of the coating was 3.4~.
** JIS No. 3, sodium silicate on a solid basis.

06~
lZC~Z8S4 It is apparant from Table 9 that the solubility is substantially unchanged though sodium percarbo nate is coated according to the process of the present invention, and the disintegrating property is remarkably improved when coated with sodium metaborate and sodium silicate according to the process of the present invention.

ExamPle 1 1 Sodium percarbonate was coated by the pro-cedure of Example 9 using various sodium silicates in combination with sodium metaborate. The follow-ing coating agents were used:
5% NaB02 4H20 + 1% (on a solid basis) sodium orthosilicate, 5% NaB02 4H20 + 1% (on a solid basis) sodium metasilicate, 5% NaB02~4H20 + 1% (on a solid basis) sodium silicate (JIS No. 1), 5% NaB02 4H20 + 1% (on a solid basis) sodium silicate (JIS No. 2), 5% NaB02 4H20 + 1% (on a solid basis) sodium silicate (JIS No. 3), and 7-1% NaB02 4H20 Each of seven samples (i.e., the above six coated sodium percarbonates and uncoated sodium ~ 65 lZ02854 percarbonate~ in an amount of lO wt.% in terms of sodium percarbonate was incorporated in a phos-phorus-free bleaching detergent having the same composition as that of Example 9. A storage stability test was conducted in a similar manner to that described in Example 9. Further, these seven sodium percarbonates were subjected to a disintegrating test in a similar manner to that described inExample 10. The samples of sodium percarbonates after the completion of the dis-integrating test were further subjected to the storage stability test. The results are given in Table 10.

Table 10 Available Disin~egrating residue, % by Coating of sodium percarbonate* residueproperty storage test after (%) disintegration test 5% NaBO2 4H2O ~ 81.0 10.8 75.1 1% sodium orthosilicate 5% NaBO2-4H2O + 82.3 9.0 79.8 1% sodium metasilicate 2 2 . 82.3 7.8 82.1 1% sodium silicate (JIS No. 1) O p~
5% Na~O2-4H2O + 84.0 6.2 83.0 C~ ~n 1% sodium silicate (JIS No. 2) 5% NaBO2 4H2O + 85.4 6.2 84.4 1~ sodium silicate (JIS No. 3) 7-1% NaB2'4H2 79 7 13.9 72.9 ~ none 31.1 13.4 30.5 * The coating ratio on a water-free basis was 3.4%.

lZO;~3S~

It is apparant from Table 10that products (l) to (5) of the present invention exhibits an excel-lent storage stability by the synergistic coating effect of the borate and the silicate. By using the borate and the silicate in combination, the coated particles have a strength which could not be obtained by the coating of only the borate.
As seen from the storage test result after the disintegrating test, damage resistance can be imparted to the coated particles. Therefore, the coating of the coated particles of the present invention is hardly damaged on the way of trans-portation in the blending stage with bleaching detergents and, even when the particles are dam-aged, the storage stability is not substantially deteriorated.
Example 12 Sodium percarbonate was coated by the pro-cedure of Example 9 with the exception that sodium metaborate and sodium silicate were used in com-bination with other coating agents shown below.
The amount of the coating agent was wt.% based on sodium percarbonate.
5% NaBO2 4H2O + 1% (on a solid base) sodium silicate (JIS No. 3) + 5% polyethylene glycol ~2~8S~

(PEG, molecular weight = 6000), 5% NaBO2 4H2O + 1% (on a solid basisJ sodium silicate (JIS No. 3) + 5% sodium carbonate, 5% NaBO2 4H2O + 1% (on a solid basis) sodium silicate (JIS No. 3) + 0.5% disodium ethylene-diaminetetraacetate (EDTA), 5% NaBO2 4H2O + 1% (on a solid basis) sodlum silieate (JIS No. 3) + 0.5~ EDTA diitriethanol-amine) salt, and 5% NaBO2~4H2O + 1% (on a solid basis) sodium silicate (JIS No. 3) + 0.5~ trisodium nitrilo-triaeetate (NTA) lO wt.% of eaeh of si~ samples (i.e., the above five-eoated sodium percarbonates and uneoated sodium perearbonate) was ineorporated in the phosphorus-free bleaehing detergent having the same eomposition as that of Example 9. A storage stability test was eonducted in a similar manner to that described in Example 9. The results are given in Table 11.

Table 11 ' Coating of sodium percarbonate residue (%) NaB02-4H20 + No. 3 sodium silicate + PEG 87. 2 5~ 1~ 5%
NaB02-4H20 + No. 3 sodium silicate + Na2C03 86.6 5% 1~ 5 NaB024H20 + No. 3 sodium silicate + EDTA-2Na 87.7 5% 1% 0.5%
NaB024H20 + No. 3 sodium silicate + EDTA- 2TEA go g ~ C~
5% 1% 0.5%
NaB02-4H20 + No. 3 sodium silicate + NTA-3Na 88.8 5% 1~ 0.5%
none 30.5 120;285 It is apparent fromTable 11 that sodium per-carbonate exhibits an excellent storage stability aLso when coated with sodium perborate, sodium silicate and other coating agents in combination.
Particularly, when sodium perborate and sodium silicate are used in combination with an organic high-molecular compound such as PEG or a sequester-ing agent such as EDTA or NTA, a synergistic effect can be obtained and the storage stability is furhter improved.
Example 13 20 kg of wet sodium percarbonate was charged in a centrifugal diffusion type mixer (Lodige Mixer, FKM-130D, T.M. Engineering Co., Ltd.). A powdered coating agent was added thereto with stirring.
Mixing was conducted for lO minutes in total. Then the coated sodium percarbonate was taken out and dried with hot air. The following coating agents were used.
5% sodium metaborate (NaBO2 4H2O) + 1% (on a solid basis) sodium silicate (JIS No. 3) +
0.5% EDTA-2TEA, 4.54% borax (Na2B4O7 lOH2O) + 1% (on a solid basis) sodium silicate (JIS No. 3) + 0.5%
EDTA-2TEA and 0'71 lZOZ8S~c 2.4~ boric acid (H3BO3) + l~ (on a solid basis) sodium silicate (JIS No. 3) + 0.5 EDTA-2TEA.
Note: The percentage is wt.~ based on sodium percarbonate.
lO g of each of four samples [i.e., the above three coated sodium percarbonàtes (two samples of the present invention and one sample of comparative example) and uncoated sodium percarbonate] was incorporated in a phosphorus-free bleaching detergent composition having a composition given below as in Examples 9 and 10. A storage stability test was conducted in a similar manner to that described in Example 9. The results are given in Table 12. Further, the residual activity bf an enzyme (alcalase 2.OM~ simultaneously incorporated in the composition was also measured.

/

~2028S4 (1971~.
Phosphorus-free bleaching detergent composition wt.%

sodium dodecylbenzenesulfonate 20.0 synthetic zeolite (type 4A) 20.0 sodium silicate (JIS No. 2) 10.0 sodium carbonate 5 0 fluorescent dye 0,5 sodium salt of carboxymethylcellulose 1.0 enzyme (alcalase 2.0M) 0.3 sodium percarbonate (coated) 10.0 water 5.0 sodium sulfate balance Total 100 Table 12 Available Enzymatic Coating of sodium percarbonate*oxygen activity residue (%) residue (%) 22 + sodium silicate + EDTA-2TEA 93 9 96.8 5% 1 1% 0.5%

Na2B2O7-10H2O + sodium silicate + EDTA-2TEA 89.0 94.6 4.54% 1% 0.5%
C
H3BO3+ sodium silicate + EDTA-2TEA 75 0 9O 4 2.4% 1% 0.5% ~D C;
~P
~ none 32.0 80.3 * The coating rate on a water-free basis was 3.9% in all cases.
** sodium silicate (JIS No. 3) 0'74 ~;Z028S4 It is apparent from Table 12that sodium per-carbonate exhibits very good stability and the enzyme also has an excellent stability, though the bleaching detergents ~ and ~ of the present in-vention contain zeolite blended therewith.
Example 1~
lO wt.~ of each of the coated sodium percarbo-nates (coated with NaB02 4H20 and Na2B407 lOH20 in combination with sodium silicate) of the present invention prepared in Example 13and two comparative samples (one coated with H3B03 in combination with sodium silicate and prepared in Example 5 and uncoated sodium percarbonate) was incorporated in a powdered bleaching detergent having a composition given below. A storage stability test was conducted in a similar manner to that described in Examples 9 and 13. The test results on the available oxygen residue of sodium percarbonate and enzymatic activity residue of alcalase 2.OM are given in Table 13, Bleaching detergent composition wt.~

sodium dodecylbenzenesulfonate 20.0 sodium tripolyphosphate 18.0 sodium silicate (JIS No. 2) lO.O

oi75 Z~3S~

sodium carbonate 5.0 fluorescent dye 0.5 sodium salt of carboxymethylcellulose 0~5 enzyme (alcalase 2.OM) 0.3 sodium percarbonate 10.0 water 50 sodium sulfate balance Total 100 Table 13 Available Enzyrnatic Coating of sodium percarbonate*oxygen activity residue (%) residue (~) 22 + sodium silicate + EDTA-2TEA 97 0 84.8 5% 1% 0.5%

Na2B2O7 10H2O + sodium silicate + EDTA-2TEA 96.0 86.0 4.54% 1% 0.5%

8B3 + sodium silicate + EDTA-2TEA 90.8 81.0 ;~
2.4% 1% 0-5%

~ none 88.8 60.5 * The coating rate on a water-free basis was 3.9%.

iZ~5 0'7'~

This example shows the use of a conventional bleaching detergent composition contalning STPP.
Here also, the composition of the present inven-tion exhibits a very excellent storage stability.
This fact shows that the bleaching detergent of the present invention has a very excellent storage stability, irrespective of whether zeolite is present or not.

lZ~ 8S~

Example 15 100 g of sodium percarbonate was charged in an agitating mixer. A 25% aqueous solution of 5 g of sodium metaborate tetrahydrate (NaBO2 4H2O) (prepared by dissolving the metaborate in water with heating) and a 25~ aqueous solution of 1 g of anhydrous magnesium sulfate (MgSO4) were sprayed thereon with stirring at 250 r.p.m. After stirring for 10 min, sodium percarbonate was dried with hot air to obtain coated sodium percarbonate.
For the purpose of comparison, sodium per-carbonate coated with only sodium metaborate (7.1 g of NaBO~-4H2O per 100 g of sodium percarbonate), one coated with boric acid (3.4 g of boric acid per lQ0 g of sodium percarbonate), one coated with boric acld and anhydrous magnesium sulfate (2.4 g of boric acid and 1 g of MgSO4 per 100 g of sodium percarbonate), and one coated with only anhydrous magnesium sulfate (3.4 g of MgSO4 per 100 g of sodium percarbonate) were also prepared.
10 wt.~ of each of these coated sodium per-carbonates was uniformly incorporated in a powdered phosphorus~free detergent having the following composition to obtain a bleaching detergent:

~;~V;~854 0'~9 phosphorus -f ree bleaching detergent composition wt.%

sodium dodecylbenzenesulfonate 20.0 synthetic zeolite (4A type) 20.0 sodium silicate (JIS No. 2) lO.0 sodium carbonate 5.0 f luorescent dye O.S
sodium salt of carboxymethylcellulose l.0 enzyme (alcalase) 0.3 sodium percarbonate lO.0 water 5.0 sodium sulf ate balance Total lO0 Six samples of compositions conta;ning, as sodium percarbonate to be incorporated in the above composition, one coated with sodium metaborate and MgSO4 according to the present invention, one coated with only sodium metaborate, one coated with boric acid, one coated with boric acid and MgSO4, one coated with only MgSO4 and uncoated sodium percarbo-nate, were subjected to a storage stability test.
The results are given in Table 14, Table 1 ~

~~~~~-- Available oxygen ~ Coating of sodium percarbonate* residue (%) Bleaching detergent of 5% sodillm metaborate (NaBO2-4H2O) 86.2 the present invention ~% MgSO4 Comparative Example 8 7.1% sodium metaborate (NaBO2-4H2O) 79.7 Comparative Example 9 3.4% boric acid (H3BO3) 60.8 2.4~ boric acid ~H3BO3) 65.0 O
Comparative Example 10 1~ MgSO4 C 3~

Comparative Example 11 3-4% MgSO4 50.8 ~n Comparative Example 12 none 3l.l * The ratio (coating ratio) of coating agent to sodium percarbonate was 3.4%
on a water-free solid basis in all cases.

:~OZ85 It is apparent that the availa~le oxygen residue of the bleaching detergent containing sodium percarbonate coated with sodium metaborate and MgS04 according to the present invention is higher than those of Comparative Examples 8 and 12, and the bleaching agent of the present invention is superior in the coating effect to those of Comparative Examples 8 to 12.
The bleaching detergent used in this example does not contain phosphorus at all and is a phos-phorus-free detergent containing zeolite blended therewith. But the bleaching detergent according to the present invention exhibits a good stability because of an excellent coating-stabilizing effect due to sodium metaborate and MgS04.
Example 16 Sodium percarbonate was coated by the pro-cedure of Example 1susing various magnesium com-pounds in combination with sodium metaborate.
The following coating agents were used:
5% NaB02 4H~O + l~ (on a water-free solid basis) MgS04, 5~ NaB02 4H20 + 1% (on a water-free solid basis) MgCQ~, 5~ NaB02 4H20 + l~ (on a water-free solid lZ~)Z8S4 basis) 2MgO-3SiO2, @ 5% NaBO2 4H20 + 1% ~on a water-free solid basis) MgO and 7-1% NaBO2-4H20 l0 wt.% of each o~ six samples (i.e., the above five coated sodium percarbonate and uncoated sodium percarbonate) was incorporated in the phos-phorus-free bleaching detergent having the same composition as that of ~xample 15. A storage stability test was conducted in a similar manner to that described in Example 15. The results are given in Table 15.

Table 15 Available Coating of sodium percarbonate* oxygen residue, %
5% NaBO2 4H20 + 1% MgS04 85.8 5% NaBO2 4H20 + 1% MgCQ2 83.9 5% NaBO2 4H20 + 1% 2MgO 3SiO2 84.0 5% NaBO2 4H20 + 1% MgO82.1 7-1% NaB2 4H2 79 7 none 3l.l *The coating ratio was 3.4% (on a wa-ter-free basis) based on sodium percarbonate in all cases.

~Z~)Z85 (~3 It is apparent that cornpositions ~ to ~ of the present in~ention exhibit a very excellent storage stability by the synergistic effect of the coating power of the borate and the stabilizing power of the magnesium compound.
Example 17 Sodium carbonate was coated by the procedure of Example 15with the exception that sodium metabo-rate and magnesium sulfate were used in combination with other coating agents shown below. The amounts of the coating agents were wt.% based on sodium percarbonate.
5% NaBO2 4H2O + 1% (on a water-free solid basis) MgSO4 + 5% polyethylene glycol (PEG, molecular weight -- 6000), 5% NaBO2 4H2O + 1% (on a water-free solid basis) MgSO~ + 5% sodium carbonate, 5% N~aBO2 4H2O + 1% (on a water-free solid basis) MgSO~l + 0.5% disodium ethylene-diaminetetraacetate (EDTA 2Na), 5% NaBO2 4H2O + 1% (on a water-free solid basis) MgSO4 + 0.5% EDTA di(triethanolamine) salt (2TEA) and 5% NaBO2 4H2O + 1% (on a water-free solid basis) MgSO4 + 0.5% trisodium nitrilotri-3~Z(;~2854 08d~

acetate (NTA-3Na).
lO wt.% of each of six samples (i.e., the above five coated sodium percarbonate and uncoated sodium percarbonate~ was incorporated in the phosphorus-free bleaching detergent having the same composition as that of Example 15. A storage stability test was conducted in a similar manner to that described in Example 15. The results are given in Table 3.

Table 16 Available Coating of sodium percarbonate oxygen residue, %

NaBO2 4H2O + MgSO4 +- PEG 88.0 NaB2'4H2 + MgSO4 Na2 3 5% 1% 5% 86.0 5% 1% 0.5% 86.0 NaBO2 4H2O + MgSO4 + EDTA 2TEA 9l.8 NaBO2 4H2O + MgSO4 + NTA 3Na 90.6 none 30.5 It is apparent that sodium percarbonate exhibit a very excellent storage stability alsc when coated ~;~0~8S4 with sodium metaborate, magnesium sulfate and other coating agents in combination. Particularly, when sodium metaborate and MgS04 are used in combination with an organic high-molecular compound such as PEG or a sequestering ayent such as EDTA or NTA, the storage stability is further improved by the synergistic effect.
Example 18 The solubility, compression strength and dis-integrating property of the coated sodium percarbo-nates prepared in Example 17were examined. The results are given in Table 17, Table 17 . .t Compression Disintegrating Coating of sodium percarbonate S(usebl) Y (kg/cm2) property NaBO2 4H2O + MgSO4 + PEG 94 18.9 15.0 5% 1% 5%

NaBO2 4H2O + MgSO4 + Na2CO3 93 19.6 14.7 5% 1~ 5 O2-4~2O + MgSO4 + EDTA-2Na 91 19.2 14.6 5% 1% 0~5%
24H20 + MgSo4 + EDTA.2TEA 9O 21.3 13,3 0~ ~0 5% 1% 0;5%
O2 4H2O + MgSO4 + NTA-3Na 95 22.1 13.3 5% 1~ 0.5%
none 90 20.6 13.4 lZO'~8S~
0~7 It is apparent fromTable 17 tha-t the solubil-ity, compression strength and disintegrating pro-perty of sodium percarbonate coated according to the process of the present invention are nearly equal to those of uncoated sodium percarbonate Example 19 20 kg of wet sodium percarbonate was charged in a centrifugal diffusion type mixer (Lodige Mixer, FKM-130D, T.M. Engineering Co., Ltd.~. A powdered coating agent was added thereto with stirring.
Mixing was conducted for 10 minutes in total.
Then the coated sodium percarbonate was taken out and dried with hot air. The following coating agents were used:
5% sodium metaborate (NaBO2 4H2O) ~ 1% (on a water-free solid basis) MgSO4 + 0.5% EDTA-2TEA, 4.54% borax (Na2B4O7~l0H2O) + 1% (on a water-free solid basis) MgSO4 + 0.5% EDTA-2TEA and 2.4% boric acid (H3BO3) + 1% (on a water-free solid basis) MgSO4 + O.S~ EDTA-2TEA
Note: The percentage is wt.~ based on sodium percarbonate.
lO wt.% of each of four samples [i.e., the above three coated sodium percarbonates (two samples of the present invention and one sample of comparative example) and uncoated sodium percarbonate] was incorporated in a phosphorus-free bleaching detergent composition having a composition given below as in Examples 15 and 16.A storage stability test was conducted in a similar manner to that described in Example 15, The resu~-ts are given in Table 18. Further, the residual activity of an enzyme (alcalase 2.OM) simultaneously incorporated in the composition was also measured.

phosphorus-free.bleaching detergent composition wt.~

sodium dodecylbenzene sulfonate 20.0 synthetic zeolite (type 4A) 20.0 sodium silicate (JIS No. 2~ lO.O
sodium carbonate 5.0 fluorescent dye sodium salt of carboxymethylcellulose l.O
enzyme talcalase 2.OM) . 0.3 sodium percarbonate (coated) lO.O
water 5.0 sodium sulfate balance Total lOO

Table 18 . . Available oxygen Enzymatic activity Coat1ng of sodlum percarbonate* residue (~)residue (~3 O2 4H2O ~ MgSO4 + EDTA-2TEA 92.8 96.0 5~ 1% 0.5%

2 4O710H2O + MgSO4 + EDTA-2TEA 89.8 96.0 4.54% 1~ 0.5 H3BO3 + MgS04 + EDTA-2TEA 74.0 90 p~
2.4~ 1~ 0.5% o - O P~;
~ none 32.0 81.0 ~ cn * The coating ratio on a water-free solid basis was 3.9~ based on sodium percarbonate in all cases.

~z~
o9o It is apparent fromTable 18 tha-t ln the phos-phorus-free bleachiny detergents ~ and ~ of the present invention, sodium percarbonate exhibits a very good stability and the enzyme also has an excellent stability, though zeolite is incorporated therein.
Example 2~
10 wt.% o~ each of the coated sodium percarbo-nate (coated with NaB02-4H20 and Na2B407 lOH20 in combination with MgS04) of the present invention prepared in Example 5 and two comparative samples (one coated with H3B03/~gS04 prepared in Example 5 and uncoated sodium percarbonate) was incorporated in a powdered bleaching detergent having a composi-tion given below. A storage stability test was conducted in a similar manner to that described in Examples 15 and 19.The test results on the avail~
able oxygen residue of sodium percarbonate and the enzymatic activity residue of alcalase 2.OM are given in Table 19, Bleaching detergent composition wt.%

sodium dodecylbenzenesulfonate 20.0 sodium tripolyphosphate 18.0 sodium silicate (JIS No. 2) lO.O

~2~Z8S4 sodium carbonate 5.0 fluorescent dye 0.5 sodium salt of carboxymethylcellulose 0.5 enzyme (alcalase 2.0M) 0.3 sodium percarbonate 10.0 water 5.0 sodium sulfate balance Total 100 Table 19 Coating of sodium percarbonate* Available oxygen Enzymatic activity residue ~%~ residue (%) O2 4H2O + MgSO4 + EDTA~2TEA 96.8 86.1 5% 1% 0-.5%

Na2B4O7 10H2O + MgSO4 + EDTA 2TEA 97.8 87.2 4.54% 1% 0.5%

H3BO3 + MgS04 + EDTA~2TEA 80.5 2.4~ 1% 0.5% O

~ none 88.8 60.5 * The coating, ratio on a water-free solid basis was 3.9~.

~2(~ 54 0~3 This example shows the use of a conventlonal bleaching detergent composition containing STPP.
Here also, the composition of the present invention exhibits a very excellent storage ability. This fact shows that the bleaching detergent of the present invention has a very excellent storage stability, irrespective of whether zeolite is pre-sent or not.

lZO;~8S4 , . ..

Example 21 100 g of sodium percarbonate was charged in an agitating mixer. A 25% aqueous solution of 5 g of sodium metaborate tetrahydrate (NaBO2 4H2O) (prepared by dissolving the metaborate in water with heating) was sprayed thereon with stirring at 250 r.p.m. After stirring for 10 min, sodium percarbonate was dried with hot air to obtain coated sodium percarbonate.
For the purpose of comparison, sodium per-carbonate coated with boric acid (2.4 g of boric acid per 100 g of sodium percarbonate) was prepared.
Each of these coated percarbonates (one coated with sodium metaborate according to the present invention and the other coated with boric acid for the purpose of comparison) and uncoated sodium percarbonate was uniformly incorporated in a bleaching agent composition (1) having the follow-ing composition. These three samples of the bleaching agent compositions were subjected to a storage stability test. At the same time, their smells were examined.
Bleaching agent composition (1) wt.%

sodium percarbonate 30 )Z~3S4 0~

sodium pyrophosphate lO
sodlum lauryl sulfate 5 Glauber's salt 15 granular activating agent A* 40 Total 100 * This agent was prepared by ~ranulating 50 wt.~ of glucose pentaacetate, 10 wt.% of polyethylene glycol having an average molecular weight of 6000 and 40 wt.~ of sodium sulfate in a granulator (X-Pelleter 60-D, manufactured by Fuji Powdaru K.K.) under pressure while passing through a screen of 0.77 ~m~.

)Z~35 O

Table 20 -\ Coating of Available \ sodium o~ygen Smell \ percarbonate residue (~) Bleaching agent *5% sodium of the present metaborate 79 good invention (NaB02-4H20) Comparative 2 4% boric 61 slightly Example 1 acid (~3B03) bad smell Comparative smell of Example 2 none 40 acetic acid * The amount (on a water-free solid basis) of the coating was 2.4% based on sodium percarbonate.
It is apparent from Table 20that the bleaching agent composition of the present invention is much superior in storage stability to those of Compara-tive Examples (boric acid-coated sodium percarbonate and uncoated sodium percarbonate). The product of the present invention has no problem on smell.
Example 22 Each of three samples (sodium percarbonate coated with sodium metaborate according the present invention, sodium percarbonate coated with boric acid for the purpose of comparison, and uncoated sodium percarbonate) used inExample 21 was uni-formly incorporated in a bleaching agent composi-tion (2) having a different composition from that ~2V285 o ~>7 of Example 21. These samples were subjected to the same storage stability test as that of Example21.
The results are given in Table 21.
Bleaching agent composition (2)wt.

sodium percarbonate 40 sodium tripolyphosphate lO
fluorescent dye 0.3 perfume 0.3 Glauber's salt balance granular activating agent B* 40 Total lO0 * This agent was prepared by granuIating S wt.% of CuSO4 5H2O, 5 wt.~ of picolinic acid, 20 wt~% of polyethylene glycol having an average molecular weight of 6000 and 70 wt.% of sodium sulfate in a granulator (X-pelleter 60-D, manufactured by Fuji Powdaru K.K.) under pressure while passing through a screen of 0.7 mm~.

09~

Table 21 ~ Coating ofAvailable \ sodium oxyyen \ percarbonate residue (%) Bleaching agent *5% sodium of the present metaborate 66 invention (NaBO2 4H2O) Comparative 2.4% boric acid 25 Example l (H3BO

Comparative Example 2 none 3 * The amount (on a water-free solid basis) of the coating was 2.4% based on sodium percarbonate.
It is apparent from Table 21that the bleaching agent composition of the present invention has also an excellent storage stability in the example where a transition-metal activating agent was blended.
Example 2~
~ odium percarbonate was coated with sodium metaborate in combination with other coating agent in a similar manner to that described in Example 21.
The following combinations of sodium percarbonate with other coating agents were used. The amounts of other coating agents are wt.% based on the amount of sodium percarbonate.
5% sodium metaborate (NaBO4 4H2O) + 5% poly-ethylene glycol (PEG, molecular weight = 6000), 0~'~

5% sodium metaborate + 5~ sodium carbonate, 5% sodium metaborate + 0.5% disodium ethylene-diaminetetraacetate (EDTA), 5% sodium metaborate + 0.5~ EDTA di~triethanol-amine) salt, and 5~ sodium metaborate + 0.5% trisodium nitrilo-triacetate (NTA).
Each of six samples (i.e., the above mentioned five samples of the coated sodium percarbonate and uncoated sodium percarbonate) was uniformly in-corporated in ~ach of bleaching agent compositions having the following compositions (3-l) and (3-2).
These compositions were subjected to the same storage stability test as that described in Example 21. The results are given in Table 22.

Bleaching agent Bleaching agent composition composition (3-1)(3-2) sodium percarbonate 40 ~ 30 sodium tripolyphosphate lO
sodium pyrophosphate - lO
sodium silicate - 2 fluorescent dye 0.3 0.3 perfume 0-30-3 Glauber's salt balance balance granular activating agent C* 40 granular activating agent D* - 40 Total 100 100 wt.%
* These agents were prepared in the foLlowing manner.
Mixtures composed of the following composition C
and D were heated at about 140C and stirred until a uniform paste was formed. The paste was cooled to room temperature to solidity it. The solid was crushed and granules having a particle size of 250 to 1000 ~ were employed.
C D

sucrose octaacetate 70 FeSO~ 5H2O - 5 CoSO ~7H O - 1 sodium iminodiacetate - 5 polyethylene glycol 10 60 (average molecular weight=6000) corn starch 10 10 Glauber's salt 10 19 Table 22 Available oxygen Available oxygen Coating of sodium residue in residue in percarbonatecomposition 3-1composition 3-2 (%) ~%) NaBO2 4H2O + PEG 84 70 5~ 5%
NaBO2 4H2O + NaCO380 69 5% 5%
NaB02 4H20 + EDTA-2Na 79 69 c~
5% 0.5% G P;
NaB024H20 + EDTA-2TEA 89 72 ~- ~R
5% 0.5%
NaBO2 4H2O + NTA-3Na 86 71 5% 0.5%
not coated 42 5 ~1;20;~8S4 It is apparent from Table 22that the composi-tions of the present invention have also an excel-lent storage stability even when sodium percarbonate is used in combination with other coating agents.
Particularly, when sodium metaborate is used in combination with an organic high-molecular compound such as PEG or a sequestering agent such as EDTA
or NTA, a synergistic effect can be obtained and the storage stability is further improved.
Example 24 20 kg of wet sodium percarbonate was charged in a centrifugal diffusion type mixer (Lodige Mixer, FKM-130D, manufactured by T.M. Engineering Co., Ltd.). A powdered coating agent was added thereto with stirring. ~ixing was conducted for 10 min in total. Then the coated sodium percarbo-nate was taken out and dried with hot air. The following coating agents were used.
- ~ 5~ sodium metaborate (NaBO2 4H2O) + 0.5%
EDT~-2TEA, 4.54~ borax (Na2B4O7-10H2O) + O.S~ EDTA.2TEA
and 2.4% boric acid (H3BO3) + 0.5~ EDTA-2TEA
(the percentages are given by weight based on sodium percarbonate).

~;~o;~

Each of four samples (i.e., three samples of two coated sodium percarbonate according to the present invention and one coated sodium percarbo-nate of comparative example, and uncoated sodium percarbonate) was uniformly incorporated in each of bleaching agent compositions having the following compositions (4-1) and (4-2). These compositions were subjected to the same storage stability test as that described in Example 21. The results are given in Table 23.

Bleaching agent 31eaching agent compositioncomposition (4-1~ (4-2) sodium percarbonate 30 40 sodium carbonate (anhydrous) - 10 sodium silicate 2 2 fluorescent dye 0.3 0.3 perfume 0-3 0-3 carboxymethylcellulose 2 2 Galuber's salt balance bala granular activating agent E* 40 granular activating agent F* - 40 Total 100 100 wt.

* These agents were prepared in the following manner.
Acetone was added to mixtures having the following ~0;~8~4 compositions E and F. They were thoroughly kneaded ln a mortar and acen-tone was removed therefrom under reduced pressure. After drying, the residue was crushed to coarse grain. Granules having a particle size of 250 to 1000 ~ were employed.
E F

tetraacetylethylenediamine 70 tetraacetylglycollyl - 70 polyethylene gLycol 10 10 (average molecular weight=6000) hydroxypropyl starch 10 10 magnesium silicate 5 S
Galuber's salt 5 5 Table 23 Available oxygen Available oxygen Coating of sodium residue in residue in percarbonatecomposition 4-1 co~position 4-2 NaBO2 4H2O + EDTA-2TEA 92 90 5%* 0.5~
7 1H2O + EDTA~2TEA 88 91 4.54%* 0.5~
H3BO3 + EDTA-2TEA . 54 60 2.4% 0.5~ ~ O
~ not coated 40 41 ~

* The amount (on a water-free solid basis) of the coating was 2.4%.

~ILZ(~;~8~i4 10~) In this experiment, -~he coating of sodium percarbonate was carried out in a larger-scale than in Examples 21 to 23. It is apparant from Table 23 that thecoated products (l) and (2) of the present invention are superior in the storage stability of scdium percarbona-te to the compara-tive products (3) and (4).

iZ~)2~54 ln7 Example 25 The coated sodium percarbonate obtained in Example 24 was added to each!of two enzyrne-containing bleaching compositions given below. The resulting compositions were each examined in respect to the storage stability after they had been stored at 50 c for 20 days. Results are shown in Table 24.
composition (1) composition (2) coated sodium80 wt. ~ 80 wt.%
percarbonate sodium carbonate10 10 alcalase 2.0M 2 2 as enzyme zeolite of 4A type - 5 sodium sulfate 8 3 total amount 100 100 This example does not contain a surfactant and Nos. l and 2 among them fall within the scope of the invention, but Nos. 3 and 4 do not. It is understood from the results thàt Nos.`l and 2 were superior to the controls 3 and 4 with respect to the storage stability of the sodium percarbonate and the enzyme.
Moreover the stability of the enzyme was improved in the composition (2), containing the zeolite, than in the composition (1).

~IZ8~i4 % anpF5a~
o ~ Ar~:)e ~l~eWAZUa o ~ o o o\
~ .
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Claims (12)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A bleaching detergent composition which comprises 1 to 99 percent by weight of sodium percarbonate coated on the surface with a borate-containing coating agent.

2. A bleaching detergent composition according to claim 1 in which the sodium percarbonate is contained in an amount of 1 to 40 percent by weight.

3. A bleaching detergent composition according to claim 1 in which said sodium percarbonate is contained in an amount of 40 to 99 percent by weight.

4. A bleaching detergent composition according to claim 1, 2 or 3, in which the borate is sodium borate.

5. A bleaching detergent composition according to claim 1, 2 or 3, in which the borate is sodium metaborate.

6. A bleaching detergent composition according to claim 1, 2 or 3, in which the amount of coating agent is 0.1 to 30 percent by weight of the weight of sodium percarbonate and the amount of borate is 10 to 100 percent by weight of the weight of the coating agent.

7. A bleaching detergent composition according to claim 1, 2 or 3, in which the coating agent further contains a sequestering agent.

8. A bleaching detergent composition according to claim 1, 2 or 3, in which the coating agent contains ethylenediamine tetraacetate or nitrilotriacetate as a sequestering agent.

9. A bleaching detergent composition according to claim 1, 2 or 3, in which the coated sodium percarbonate has an average particle diameter of 100 to 2000 microns.

10. A bleaching detergent composition according to claim 1, 2, or 3, in which the coating agent further contains an alkali metal silicate or a magnesium compound.

11. A bleaching detergent composition according to claim 3, which further contains an enzyme and a synthetic zeolite.

12. A process for preparing a bleaching detergent composition, which comprises the step of coating the surface of sodium percarbonate with a coating agent containing a borate.