CA1130694A - Detergent products - Google Patents

Abstract

C.1041/3 ABSTRACT OF THE DISCLOSURE

A detergent product comprises a water-insoluble, water-permeable bag containing a particulate detergent composition, the bag material having a water-soluble or removable water-insoluble layer to protect the bag material from the composition and to reduce dusting.
The protective layer may be coated on or impregnated into the bag material or may form a continuous layer laminated to the inside of the bag material or may be in the form of a separate inner bag. The water-soluble material may be soluble polyvinyl alcohol.
polyethylene glycol, polysaccharide, alkali metal silicate, soap, nonionic detergent, gelatine, salts or esters of alginic acid. The removable water-insoluble material may be a silicone, a fatty acid, a water-insoluble cationic fabric softener, polyvinylacetate, insoluble polyvinyl alcohol, clay, zeolite, calcite, silica, titania or a wax. The bag material may be paper and/or plastics material such as polypropylene The detergent composition is-a fully formulated composition or other fabric treatment material.

Description

~3~6!~
- 1 - C.10 . . . -, - D~ERGE~ PRODUC~S
, - _ C ~ D
~ his invention relates_to detergent products which are suit~ble for fabric washing and-which contain de-tergent compositions in particuIate form.
BAGKGROUND AR
Although the marke-ting of parti~ulate detergent compositions packaged ln cartons is common practice, this - imposes co~straints both on their formula-tion and methods of production. ~or example the co~ositions must be ~ree flowing and have an a-ttractive appearance to the consumer, and the ingredients should not segregate during transport and storage. The products must also be sa~e, both for contact wi-th the skin and in the event of accidental ~3~4 - --

- 2 - C.10~1/3 inges-tion; in par-ticular, the compositions should not contain too high a level of alkaline materials, although ~lkalinity is beneficial for detergent properties.
When using ~Jashing machines which have a rotating drum in which -the fabrics are placed, there can also be substan-tial losses of conventionally dosed detergent powder by retention in the dispenser and by its accumulation in the dead spaces beneath the drum,- such as the drain hose.
It has been proposed previously to market powdered detergen-t compositions in packages~, each of which contain suitable amounts of the detergent powders for individual washes under standard washing conditio~s. In particular, from ~ritish Patent Specification ~ 98 454 and United ~tates Patent ~pecification 3 198 740 the detergent powders can be contained within bags of water-permeable or water-soluble materials, such as soluble polyvinyl alcohol, but such packages have not yet met with much commercial success~
- One of the reasons for this, in the case of water-soluble bags, is the sensitivit~ tj mo^isture which leads to storage difficulties. In the case of water-permeable materials, one of the reasons is the difficuIty~of making the bags sufficiently permeable to wa-ter in use so -that the contents of the bags are rapidly dissolved out in-to the wash liquor, and yet reducing dusting of the detergent powder out of the bags during transport and ma~ual handling to an acceptable level. Also, some detergent compositions, in particular bleach-containing compositions, cause i~acceptable degradation of the bag material~
Canadian Patent Specification ~o. 901 24ll discloses a ~0 bag for insecticide powders~ the bag being formed of a water-soluble film reinforced wi-th a net of water-insoluble thermoplastic material.
DI~C~OSUPE OF ~HE INVE~IO~
According to the invention there-is provided a detergent ~5 product comprising a particulate de~tergent composition contained within a closed water-i~soluble~ w~ter-permeable bag formed of sheet material, a layer of water-soluble or

- 3 - C.1041/3 removable water-insoluble material protecting -the bag material from the detergent composition. By using this -form of construction for the bag, i-t is possible to protect the 'bag ma*erial during storage and -to prevent undue dusting of the composition'through the bags and yet the porosity of the water-insoluble sheet material can be high enough to quickly release all of -the contents of the bag as soon as the water-soluble layer is dissolved or the water-insoluble layer is removed in use. It is possible to use a relatively open water-insoluble sheet material for the bag, as dusting of the de-tergent composition through'the pores is reduced or pre~rented by the water-soluble or removable water-insoluble layer. Moreover, it is possible -to form the bags of material which can be readily'heat-sealed, which facilitates manufactureO
~EST M03E 0_ CA~RYING OUT THE I~VE~TI0~
~ he b~s are formed with a water-insoluble sheet material which can be formed of paper or of woven, knitted or non-woven fabric, provided that each of these should be water-insoluble and water-permeable. If the bags are to be used for detergent powder which co~tains a bleachlng agent, for example sodium perborate or sodium percarbonate7 it is also desi'rable to form the bags of sheet material made from oxidation-resistan-t fibres.
A suitable sheet material for forming -the bag~ is water-permeable paper or non-woven~'fabric of high we-t strength, weighing about 5 to 100, preferably 10 to 60 g/m2 - especially about 15 to 40 g/m2, such as is commonly used for packaging beverage powders and other foodstuffs~ and sui-table sheet materials of this -ty~e are commerciall~
available for example from J R Crol~pton ~ros Ijtd of Bury~
~ngland ~he fibres preferably usèd for -the sheet materials may be of na-tural or sy~thetic origin and may be used alone or in admixture, for example polyamide, poly-ester, polyacrylic, cellulose acetate, polyethylene, poly-propylene, PVC, PVdC (polyvin~lidene chloride) or cellulcsic fibres~ If some cellulose pulp is used, it may be ~L~3~

- 4 - C.1041/3 desirable to include a proportion of long fibres such as Manila hemp, in order to improve the s-trength oi the sheet ~material, and pliability, and reducing stiffness, -thereby giving the ma-terial a fabric-like appearance, and a binder may be necessary for increasing we-t streng-th. I~ is preferred to include at least a proportion of thermoplastic~
fibres, for example polypropylene fibres for increasing resis-tance to chemical attack by any.of the ingredients of the detergent compositions~
~he lay~r of water-soluble or water-insoluble material may be either a continuous layer or sheet of such matérial or a discontinuous layer. Tn the;former case the continuous layer can be attached, i;e. laminated to the water-insoluble sheet material, insidë the sheet material of the bags, or it may be separate ~.rom the sheet material, so formi ng one bag inside the other. Particularly in the laminated form.of construction of the.bags using a continuous layer or sheet of a water-soluble material, i-t is preferred to use a syn-thetic water-soluble p~lymer (homopolymer or copolymer) such as soluble polyvi~yl alcohol or ~oly-ethylene glycol.
Par-ticularly if a water-solubl.e material is applied as a discontinuous coating on the water-insoluble sheet material, a wider variety of wa-ter-soluble ma-terials can be used to give a protective effect7 for example polysaccharides such as starch or dextrin, alkali metal silicate, soap, gelatine, salts and esters of alginic acid, salts and esters of me-thyl cellulose, carbox~methyl cellulose and water-soluble cationic fabric softeners or water-soluble synthetic polymers such as wa-ter-soluble polyvinyl alcohol, polyethylerie glycol or nonionic dc~er~ent compounds.
The water-insoluble sheet material may alternatively be treated with a removable water-in$oluble protecting agent. ~his can either be a non-volatile liquid or solid material,.of organic or inorganic nature, provided that it is substan-tially inert to the deter~ent system and can be applied to -the sheet material, be.~ore or af-ter forming the ~3~4 bags, to give a protective effect~ The removable water-insoluble protecting agent should be water dispersible so that, in use, it is quickiy removed from the bag material, thereby opening up the pores in the bag material enabling fast dissolution and disper-sion of the detergent composition in the wash li~uor. In thisspecification the term "removable water-insoluble protecting agent" is to be construed accordingly. Specific protecting agents which may be mentioned are waxes which are solid or highly viscous liquids at room temperature, and which can be applied to the sheet material to form a protective coating over the fibrous surface. Such materials are dispersible in detergent wash liquor, especially at elevated temperatures where they may then also exert a beneficial lather controlling effect. The waxes are well known commercially available substances. The waxes can be of natural or synthetic origin and optionally halogenated to improve their chemical stability.
Alternative protecting agents are silicones,~fatty acids, water-insoluble cationic fabric softeners, polymeric materials such as polyvinylacetate, insoluble polyvinyl alcohol and insol-uble finely divided inorganic material, such as natural clays orsynthetic colloidal filler substances such as zeolite, calcite, silica or titania, which can be applied to the sheet material so as to coat the fibres and to some extent temporarily close the pores of the sheet material until its addition to water. Pre-ferably, clays are used for this purpose, for example kaolin,attapulgite, Fuller's Earth, bentonite, montmorillonite and smectite clays. Some of the clays, especially the smectite clays, can have a fabric softening action in the wash after their removal from the bags in use.
Mixtures of protecting agents may be used, especially mix-tures of the liquid or waxy solids with the finely-divided inor-ganic materials. The former can thereby assist the adhesion of the latter to the sheet material to enhance the protective effect.

,/

6 ~3'~ 4 G 1041/~

In the case of the coating ma-terial bein~ a ~:rax,it is preferably applied to the sheet material before lt is formed into the bags by passing the sheet ma.terial -through a bath of wax or by spr~aying on -the wax, ei-ther as a hot melt or preferably in solution or as an agueous emulsion. ~he gravure printing process used for waxing paper, such as operated by George Makin ~imited, ManGhes-ter, ~ngland, is suitable Por such process. ~he wa-ter or organic solvent used to apply the wax in -this way is later removed, for example by hea-ting, and this facilitates the more uniform application of the wax to the shee-t: material at acceptable levels. ~he particulate inorganiG'protecting agents such as clays should be applied by coating, impregnating, padding or spraying on an aqueous organic.solvent suspension, or preferably in admixture with the liquid or waxy solid materials. In the case of a removable ~ater-insoluble protect;;~e agent , the amount thereof`used is advantageously .. about 0.~% to about 50%~ preferably~about 1 - 20% by weight based on the sheet materia.l. ~ hese trea-tments also minimise dusting, and protect the bag materiai.from attack by -the .
detergent compositionsD If the layer of water-soluble or removable water-insoluble material is discon-tinuous it is -preferably attached for support to the water-soluble sheet material and may be applied there~o'by impregna-tion, 25 - saturation or coating. '.
When a sheet material is used'coated with a dis-continuous water-soluble or remov~bIe water-insoluble layer, the pore size of the coated.sheet material should be such that there is no excessive:dusting of the deterO~ent ~0 composition through the material of the bags in the dry state~ but preferably no-t so small that wa-ter c~nnot pass readil-g through the material forming the bags to disperse and dissolve the con-tents when the product is used~ ~he preferred level of coating is thus a function of the pore ~5 size distribution of -the uncoated pag'material, :the particle size distribution of the de-tergent comp~sition and -the acceptable degree of dusting. ~or optim~m - 7 - ~3~

properties the degree of dusting is such that no more than about

5%, by weight, preferably no more than about 1%, of the deter-gent composition particles can pass through the coated sheet material. With very fine powders, for example made by dry mix-ing, the maximum pore size of the treated sheet material must be very small, preferably so as to retain only detergent particles greater than about 20 microns. With coarser grained detergent compositions the maximum pore size of the treated sheet material may be larger so as to retain detergent particles greater than about 100 microns, e.g. about 500 up to about 1000 microns, as appropriate. It may be noted that larger pore sizes are generally better for dissolving powder quickly, but this puts more con-straints on the powder processing techniques which can be used in order to avoid e~cessive dusting.
Where the bag material is water-permeable paper or non- -woven fabric of high wet strength weighing about 10 to about 60 g/m , or other material having a similar pore s`ize distribu-tion, a coating thicknesc of from about 15 m/g2 to about 45 g/m2, advantageously about 30 g/m2, is preferred.
The bags can be formed from a single folded sheet formed into a tubular section, or from two sheets of the material bonded together at the edges. For example, the bags can be sachets formed from single folded sheets and sealed on three sides or from two sheets sealed on four sides for the preferred rectangular shape. Alternatively, the sheets can be folded like envelopes with overlapping flaps to be sealed. Other bag shapes or constructions, for example circular cushion shaped sachets or of tetrahedron form, may be used if desired. The bags may also be reinforced, if desired, to decrease the risk of leakage during handling, for example by adding an extra thickness of the sheet material where the bags are expected to be held or passing com-pletely round the bags to help support the weight of detergent powder.
The bags may be sealed by heat-sealing, cold pressure sealing or with an adhesive. In the case of heat-sealing ~ ~ 3 ~. ~,~ 4 - 8 - G.1041~3 the bag material should contain at leas-t a minor proportior~
of a thermoplastic ma-terial, such as polypropylene.
~lternatively, the bag material may be coa-ted with a layer of heat-sealable ~r pressure sealable material such as a vinyl acetate/vinyl chloride copolymer~
~ o increase the ra-te of dispersion and dissolu-tion of the detergent composi-tion in the wash liquor, the bag may be adap-ted -to open in the wash, for example by bursting at a weak seal or along a perforation line, by the dis-integration o -the bag material itself'or by at least one of the seal~ being formed with a water-soluble adhesive that will dissolve in the wash liquor. ~he"invention is also applicable to bags that do not open in -the wash.
Any detergen-t composition in particulate form can be packaged to advantage in the produc-t of the invention. As an alter~at_vc to a fully formulated detergent composition (that is a co~position containing at least a surfactant and a builder? tne bags may contain any one or more of the - following fabric treatment mate`rials: bleaches such as sodium perborate; bleach precursors such'as tetraacetylethylene diamine (~AE~); fabric softeners such as'quaternary ammonium compounds, starch, perfumes, anti-bacterial agents; stain removing agents and the like. I-t can be of particular advantage to add fabric -treatment materials to the wash in a bag while dosing a fully formulated detergent ~omposition in a conventional manner, where the incorporation of the fabric treatment material in the fully formulated detergent composition may o-therwise be difficult. ~QiS iS of particular importance in the cas~ of' perfu1lles., bleaches, bleach precursors and cationic fabric softening agents.
~ he fully formulated compos'itions w~Lch can be packaged -to advanta~e in the produc-ts of the invention are amply described in`the literature, for example in "~urface ~ctive Agents and Detergents", Volumes I and II',~by ~chwartz, ~5 Perry and Berch.
However, the products of -the inven-tion are advantageous-ly used for detergents powders containing insolub1e ~3't3 ~
_ 9 _ C.104~/3 ingredients. Specific examples of such ingredients include finely divided calcium carbonate, the use of whicrL
-is described in UK patent No. 1 437 950, and sodium aluminosilica-te ion-exchange materials as.described in UK
patent specifications Nos. 1 429 143, 1 473 201 and 1 473 202.
It is also advantageous to us.e t~e pro~ucts of this invention with de-tergent composi-tions containing bleach sys-tems, particularly containing ~AED and sodium perborate.
In addition, the de-tergent products of the invention . are particularly suited for detergent compositions of .relatively high bulk densi-ty, i.e. over about 0.5 g/cc, preferably about 0.6 to 0.8 g/cc, up to a maximum of about 1 g/cc, above which there tends to be. a reduction in the rate of water solubili.ty or dispersibili-ty. ~he use of high bu~r de~sity compositions makes it possible to decrease the size of the detergent~bags whils-t still containing enough particulate detergent composition to be fully effective during use. This also enables -the use of simple processing techniques for the production of the - detergent compositions themselves, e~g. granulation or dr~
mixing instead of traditional spray drying techniques.
If desired, the sheet material used to form the bag - can be marked or tagged so that it can be easily recognised amongs-t the washed fabrics, for example the material may be printed with a simulated fabric patterns such as check or gingham~ It can then either be disGarded, or; if desired, it may be constructed of a suitable.material to proyide it with a secondar-~ use, for exampl0:as:`a cleaning cloth.
If desired7 the bags can be formed with more than one separate compar-tment:-Gontai.~i.ng differen-t detergent I ingrad-e~ts or the bags ma~ be formed in a conjoined manner, for exa~ple in.a s-trip:to facilita-te dosing of different numbers of the bags as appropriate for the wash conditions~
~he use of multi-compartment bags t`acilitates the use of detergent ingredients which would otherwise in-teract with ~3~

other ingredients in detergent compositions, whilst avoiding encapsulation or other treatment to prevent contact between such ingreaients in a single composition.
For example one compartment may contain a fully formulated detergent free of bleach while a second compartment may contain the bleach. A third compartment may contain a fabric softener.
The invention is illustrated by reference to the follow- -ing Examples in which parts and percentages are by weight except where otherwise indicated.
EXAMPLES 1 to 3 Bags for detergent compositions were constructed with a laminated construction~having a water-soluble polyvinyl alco-hol sheet (HI-SELON C ~ ) of thickness 0.0015 inch inside water- -insoluble sheet materials as follows: -EXAMPLE 1 - Manila hemp with viscose wet strength agent 21 g/m2) EXAMPLE 2 - Manila hemp fibres treated with Kymene/poly-meric wet strength agent and with a 20:80 vinyl acetaie/vinyl --chloride copolymer as heat sealing agent. Weight 27 g/m2.
EXAMPLE 3 - Highly porous polypropylene spun-bonded non-woven fabric. Weight 10 g/m . ~:-All three types of bags were made by folding t~e super- -imposed water-soluble and water-insoluble sheet materials -(former inside) ~nd then heat-sealing along the two opposing edges. 84 g of a detergent composition of high bulk density (0.68 g/cc) prepared by a granulation process as described in Belgian patent No. 867 038 to the formulation below was then added to the bags which were heat sealed along the ~pen edges to form sachets (4 1/2" x 4 1/2"). ---3~

Ingredient Nonionic detergent surfactant 14.0 Sodium carbonate 34.0 Calcium carbonate (80 m2/g) 18.0 --Sodium perborate 25.0 Sodium carboxymethylcellulose 3.3 Fluorescent agent, perfume 1.0 Water 4.7 --The bags were found to exhibit improved storage properties under high relative humidities and to give good detergent prop-erties in use. The bags of Example 1 and 2 opened within 2 minutes in the wash, the first by dissolving the polyvinyl alco-hol sheet which also formed the seal, and in Example 2 by burst- -ing the bags along a seam. `The bags of Example 3 did not open --in the wash but liberated their contents through the highly por-ous polypropylene sheet material after dissolution of the poly-vinyl alcohol sheet, under the vigorous agitation in the washing machines. --~
EXAMæLE 4 Sheets of Manila hemp with viscose wet strength agent (21 g/m2) were treated with an even coating of a water-insoluble polyvinyl acetate homopolymer obtained from National Adhesives and Resins Limited, Slough, ~ngland. The coating material, in the form of an aqueous dispersion, was spread evenly on one side of each sheet using a c~lindrical metal rod. The treated sheets were dried in air. On examination it appeared that the coating had penetrated the paper. Bags were prepared from these treated sheets by heat sealing, the bags containing 80 g of a carbonate/
calcite powder as used in Examples 1 to 3. The bags were 4 1/2" --x 4 1/2". None of the bags gave unacceptable dusting during handling. These bags were examined to determine whether tne pow-der was released into the drum of a front loading automatic wash-ing machine after agitation for 2 minutes. It was found that bags having a coating of 19 or 22 g/m2 were open and empty after 2 minutes.

'~.
,~

~ ~3 ~ 6~4 - 12 - G.1041/~

XAMPIE 5~
Bags were prepared as in Example 4 above, but -containing 60 g of a carbona-te/calci-te powder containing percarbona-te. `~he bags were s-tored'.at.20C/90% P~
-together wi-th con-trol bags made of untrea-ted Manila hemp with viscose we-t s-trength agent, provided with a coa-ting of polyvinyl acetate on the edges only9,for heat sealing purposes. ~he bags were examined at'weekly intervals to de-termine whether -the coatings had'conferred resistance to degradation on the bag material. ;~he results were as follows: , Wei ~ ~ime taken to de~rade 0 (Control) 1 week 19 3 weeks 15 22 ' 2 weeks 37 ' ~ weeks '"4'weeks ~ hese results show that wi-th this particular coating material a coating weight of not less'than about 19 g/m2 gives improved stability against degradation.

~ xample 5 was repea-ted with ~arious ~bag'materia'ls and coating materials. Bag material degradat-ion was assessed from the bréaking strengths of 1 cm wide strips cut from the bags after storage. The results were:
~ .ag ... ;.Coati~g ' Goating. .S-torage ~reaking 'material material ~ h-t time ~ stren ~h .Sau~.age Clay* 0 g/m 11 days 1041 g (19 g7m ) 31 g/~2 , ,9 g . ~7 g/m - 'l630 g Sausage Silicone 0 g/m2 21 days NI~
^asin7 ~ 4 g/m2 ~59 g ~ea bag , 0 g/m2 37 g ~aper 2 5 g/m2 f 251 g ~5 * 'IDinkie-A" -- Regis-tered ~rade Mark.

Claims (19)

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

1. A detergent product comprising a closed water-insoluble, water-permeable bag formed of sheet material, a particulate detergent composition contained within said bag and a protective layer surrounding said particulate detergent composition to protect said sheet material from said detergent composition, said protective layer being a layer of a material selected from the group consisting of water-soluble materials and removable water-insoluble materials.

2. A detergent product according to Claim 1, wherein said bag is formed of a material selected from the group consisting of paper, woven fabrics, knitted fabrics, non-woven fabrics and plastics sheet materials.

3. A detergent product according to Claim 1, wherein said bag is formed of fibres selected from the group consisting of polyamide, polyester, polyacrylic, cellulose acetate, polyethylene, polypropylene, PVC, PVdC and cellulosic fibres and mixtures thereof.

4. A detergent product according to Claim 1, wherein said protective layer is a continuous layer of water-soluble material.

5. A detergent product according to Claim 4, wherein said continuous layer is laminated to said sheet material.

6. A detergent product according to Claim 4, wherein said continuous layer is in the form of a water-soluble bag positioned inside said water-insoluble bag.

7. A detergent product according to Claim 1, wherein said protective layer is a discontinuous layer of water-soluble material carried by said sheet material.

8. A detergent product according to Claim 7, wherein said discontinuous layer is coated on said sheet material.

9. A detergent product according to Claim 7, wherein said discontinuous layer is impregnated in said sheet material.

10. A detergent product according to Claim 1, wherein said water-soluble material is a synthetic water-soluble polymer.

11. A detergent product according to Claim 10, wherein said water-soluble polymer is selected from the group consisting of soluble polyvinyl alcohol and polyethylene glycol.

12. A detergent product according to Claim 1, wherein said water-soluble material is selected from the group consisting of polysaccharides, alkali metal silicates, soaps and nonionic detergent compositions.

13. A detergent product according to Claim 1, wherein said water-soluble material is selected from the group consisting of gelatine, salts and esters of alginic acid, salts and esters of methyl cellulose carboxymethyl cellulose and water-soluble cationic fabric softeners.

14. A detergent product according to Claim 1, wherein said removable water-insoluble material is selected from the group consisting of silicones, fatty acids, water-insoluble cationic fabric softeners, wax and clay.

15. A detergent product according to Claim 1, wherein said protective layer has thickness of between about 15 g/m2 and about 45 g/m2.

16. A detergent product according to Claim 15, wherein said thickness is about 30 g/m2.

17. A detergent product according to Claim 7, wherein said particulate detergent composition has a particle size distribution, said sheet material has a pore size distribution and said protective layer has a thickness in relation to said particle size distribution such that less than about 5% of the detergent composition particles can pass through the pores of said sheet material.

18. A detergent product according to Claim 7, wherein said particulate detergent composition has a particle size distribution, said sheet material has a pore size distribution and said protective layer has a thickness in relation to said particle size distribution and said pore size distribution such that less than about 1% of the detergent composition particles can pass through the pores of said sheet material.

19. A detergent product according to Claim 1, wherein said detergent composition is selected from the group consisting of fully formulated detergent compositions, bleaches, bleach precursors, fabric softeners, starch, perfumes, anti-bacterial agents, anti-static agents, whitening agents, blueing agents, stain removing agents and mixtures thereof.