WO2008115934A1

WO2008115934A1 - Methods for generating non cellulose microfibres comprising an active ingredient

Info

Publication number: WO2008115934A1
Application number: PCT/US2008/057389
Authority: WO
Inventors: Jeffrey Fowler
Original assignee: Syngenta Participations Ag
Priority date: 2007-03-19
Filing date: 2008-03-19
Publication date: 2008-09-25

Abstract

The present invention relates, inter alia, methods for generating non cellulose microfibres which comprise an active ingredient. The invention also relates to the use of such microfibres in a method of manufacturing a material which, in particular, comprises cellulose. More specifically the active ingredient is a fungicide and the material is paper.

Description

METHODS FOR GENERATING NON CELLULOSE MICROFIBRES COMPRISING

AN ACTIVE INGREDIENT

The present invention relates to methods for generating non cellulose microfibres which comprise an active ingredient. The invention also relates to the use of such microfibres in a method of manufacturing a material which, in particular, comprises cellulose. More specifically the active ingredient is a fungicide and the material is paper.

Materials which comprise cellulose, such as paper, are particularly prone to fungal attack since the cellulose acts as a carbon based nutrient source. Such fungal attack often leads to degradation of the material which in turn can result in loss of mechanical properties. Growth of fungi on cellulose containing materials also leads to staining often accompanied by unpleasant smells. This can significantly affect the appearance of the material and can lead to an increased requirement for maintenance requiring much effort and expense.

One area where such fungal contamination is of increasing significance is in wallboards. Contamination of wallboards is not only unsightly but is also cause for concern in relation to human health. Various health problems have been attributed to fungi which can contaminate wallboards, with most common of such health problems being allergic reactions and in some cases, human infection. Certain fungi which are capable of growing on wallboards are also thought to be carcinogenic.

In the light of this escalating problem wallboard manufacturers are increasingly looking to incorporate antifungal agents into their products. This in turn has presented further issues of which there is a desire in the industry to seek solutions. One such issue is ensuring that there is minimal waste of the antifungal agent during the manufacturing process of the wallboard for environmental and cost saving reasons. In particular, there is an increasing desire to reduce and preferably eliminate the amount of active ingredient in the effluent water which is generated during the manufacture of cellulose containing materials such as paper. Furthermore, there is a desire to ensure that once incorporated into the material, the antifungal agents retain good activity for a prolonged period of time.

The present invention is directed towards, inter alia, providing solutions to the problems which exist in the art.

According to the present invention there is provided a method for generating non cellulose micro fibres comprising an active ingredient, comprising: (a) generating a solution (1) which comprises dissolved polymer and/or polymerisable or cross-linkable monomers and dissolved and/or dispersed active ingredient in a first solvent; and (b) adding said solution to a further solvent or mixture of solvents (2) wherein said polymer, monomers and said active ingredient are substantially insoluble in said further solvent or mixture of solvents; and (c) precipitating the polymer and optionally the monomers from the solution wherein said active ingredient is substantially confined within the precipitate. The skilled person will recognise that the method of the present invention includes a variation wherein in step (b) the solvent is added to the solution rather than the solution added to the solvent. The solvent and further solvent according to the invention are fully miscible and a solute or surfactant may be present in said further solvent in order to achieve the requisite miscibility and polymer wettability as described below, all of which will be apparent to the person skilled in the art. In particular the method of adding the solution to the solvent or mixture of solvents is performed by continuously injecting a jet or stream of the solution into a stirred vessel or flow stream of the solvent or mixture of solvents, such that the precipitated polymer and optionally monomers and said active ingredient forms into solid particles of high aspect ratio.

"Microfibre" means a, rod-like fibre which has a length of between about 0.1 to 5000 microns and will have a generally circular or elliptical cross section and/or blunt ends. The synthetic micro fibres of the invention may be made of, for example, epoxy resin; polyacrylate or derivatives; vinyl; polyester; polyurethane; polyurea; polythene; polyethylene; polypropylene or any other like polymer that would be considered suitable by the person skilled in the art. The microfibres may be polymer-based, monomer-based or non-crystalline based. In a particular embodiment of the invention epoxy resin SU-8 is dissolved in a solvent such as ethyl lactate. Following addition of the active ingredient to this solution it may be added to a further solvent which comprises glycerin.

In a further embodiment of the invention polymethymethacrylate is dissolved in a solvent such as acetone. Following addition of the active ingredient to this solution it may be added to a further solvent which comprises water, which may additionally contain surfactants.

In one embodiment of the invention the polymer and/or polymerisable or cross-linkable monomers are dissolved into the solution such that the dissolved polymer and/or polymerisable or cross-linkable monomers form at least about 1% of the solution. In a further embodiment, the dissolved polymer and/or polymerisable or cross-linkable monomers form at least about 10% of the solution. In a still further embodiment the dissolved polymer and/or polymerisable or cross-linkable monomers form at least about more than 10% of the solution.

The present invention further provides a method as described above wherein at least 75% of the active ingredient is confined within the precipitate. In a further embodiment at least 80% of the active ingredient is confined within the precipitate. In a further embodiment at least 85% of the active ingredient is confined within the precipitate. In a further embodiment at least 90% of the active ingredient is confined within the precipitate. In a further embodiment at least 95% of the active ingredient is confined within the precipitate.

The present invention still further provides a method as described above wherein the precipitate is constituted substantially by polymerised monomers.

The present invention still further provides a method as described above wherein polymerisation of the monomers in the micro fibres is further facilitated via UV light and/or reaction at elevated temperature. - A -

The present invention still further provides a method as described above wherein a polyfunctional amine is added to further facilitate polymerisation of said monomers in the microfibres. In one embodiment said amine is added to the further solvent or mixture of solvents.

The present invention still further provides a method as described above wherein said further solvent or mixture of solvents further facilitates polymerisation of said monomers in the microfibres.

In a further aspect of the invention there is provided a method for generating non cellulose microfibres comprising an active ingredient said method comprising (a) generating a solution (1) by dissolving and/or dispersing an active ingredient in a first solvent which comprises dissolved polymer and/or polymerisable or cross-linkable monomers; (b) combining said solution with a further solvent or mixture of solvents (2) to produce a further solution wherein said polymer and monomers and said active ingredient are substantially insoluble in said further solvent or mixture of solvents; (c) precipitating said polymer and optionally the monomers into microfibres which confine said active ingredient. The solution may be combined with a further solvent or mixture of solvents by simply pouring the former into the latter, or by injecting the former into the latter through a tube having an opening below the surface of the liquid, and where the solvent or mixture of solvents is swept past the addition point such that the incoming stream of solution is subjected to extensional flow deformation, for example via a pump or an electronic rotary mixing device, such as a mechanical stirrer. With respect to the methods throughout this specification the solution (1) and the solvent or mixture of solvents (2) can also be mixed via mixing methods well known to the person skilled in the art.

In a particular embodiment the invention provides a method as described herein wherein solution (1) is injected into the solvent or mixture of solvents (2) or vice versa. In a preferred embodiment said solution (1) is injected into the solvent or mixture of solvents

(2). In a particular embodiment of the invention as described above, the interfacial tension between said polymer and said further solvent is sufficient to ensure that once formed the microfϊbres retain an average length from about 0.1 microns to about 5000 microns. In a further embodiment said fibres are from about 1 micron to about 5000 microns in length. In a further embodiment said fibres are from about 100 micron to about 5000 microns in length. In a further embodiment said fibres are from about 500 micron to about 5000 microns in length.

In a still further embodiment there is provided a method as described above wherein when said polymer is precipitating into the micro fibres, the contact angle of the further solvent wetting said micro fiber is less than or equal to about 90°. In a further embodiment said contact angle is less than or equal to about 70°. In a still further embodiment said contact angle is less than or equal to about 50°. In a still further embodiment said contact angle is less than 50°. During formation of the micro fibre in accordance with the methods of the invention, the micro fibre it is wetted via contact with the further solvent within the solution in which the fibre is formed. If the micro fibre forms contact with the further solvent via an angle as described above the microfϊbre is capable of retaining the rod- like shape for a greater period of time and is therefore more stable. The person skilled in the art is capable of selecting an appropriate combination of dissolved polymer and further solvent such that upon precipitation and formation of the microfϊbre, the contact angle as mentioned above is achieved.

The present invention still further provides a method as described above wherein the first solvent and further solvent are fully miscible.

In a particular embodiment of the invention said micro fibres are harvested from said further solution.

The non-cellulose active ingredient containing microfibres according to the invention may also be generated via other methods which are known in the art for the generation of the microfibres per se, wherein such prior art methods are modified to allow for the inclusion of the active ingredient so that the active ingredient becomes incorporated in the microfϊbre. Examples of alternative microfϊbre synthesis methods include, electro spinning which is well known to the person skilled in the art.

In addition, the microfϊbres may be generated via dissolving and/or dispersing the active ingredient in a polymer melt. The active ingredient containing melt may then be emulsified via a conventional means, (such as surfactant stabilised, colloidally stabilised or maintained temporarily via mechanical agitation), into a heated further solvent. Whilst the emulsion is subjected to an extensional flow deformation, it is cooled below the solidification temperature of the polymer such that the stretched droplets form solid micro fibres. This method obviates the need to dissolve or disperse the active ingredient in a solvent as per the method described above.

A still further method to generate the microfibres involves dissolving and/or dispersing the active ingredient in a solution which comprises monomers which can be subsequently cross-linked into polymer. The solution may be stirred into water which optionally contains a solute and the solution may be emulsified using emulsifϊers known to the person skilled in the art. The resulting emulsion may then be subjected to an extensional flow deformation wherein the monomers may be cross-linked to form the solid microfibres. Such cross-linking may be achieved via the methods well known in the art and applicable to the monomers used in the method.

In a further aspect of the invention there is provided a method for manufacturing a material which comprises cellulose which material additionally comprises non cellulose microfibres comprising an active ingredient, comprising: (a) generating non cellulose microfibres which comprise an active ingredient and

(b) adding said microfibres to a material which comprises cellulose. The microfibres may also be added to other materials such as paper, wood and other like cellulose containing items.

In a further aspect of the invention there is provided a method of preventing or reducing fungal infestation of a material comprising cellulose comprising the steps of: (a) generating non cellulose microfibres which comprise a fungicide; and (b) adding said microfibres to a material comprising cellulose. In a still further aspect of the invention there is provided a method for increasing the retention of an active ingredient in a material which comprises cellulose said method comprising providing non cellulose microfibres which comprise said ingredient and adding said microfibres to said material or a precursor thereof.

The microfibres containing the active ingredient may be generated as described in this specification.

The present invention still further provides a method as described above wherein said active ingredient is selected from the group consisting of: fungicide, herbicide, insecticide, molluscicide; arachnidicide; nematicide, bactericide and viricide.

In a particular embodiment of said method said ingredient is a fungicide. In a further embodiment said fungicide comprises a strobilurin or a strobilurin type fungicide.

Strobilurin and strobilurin-type fungicides are a well-known class of fungicides that act by inhibiting mitochondrial respiration by blocking electron transfer between cytochrome b and cytochrome C₁ at the ubiquinol oxidising site. They include the methoxyacrylate strobilurins such as azoxystrobin and picoxystrobin, the oximinoacetate strobilurins such as kresoxim-methyl and trifloxystrobin, the oximinoacetamide strobilurins such as dimoxystrobin, metominostrobin, orysastrobin (BAS 520) and the strobilurin of the formula:

the dihydrodioxazine strobilurins such as fluoxastrobin, the methoxycarbamate strobilurins such as pyraclostrobin, the strobilurin of the formula:

the imidazolinones strobilurin-types such as fenamidone, and the oxazolidinedione strobilurin-types such as famoxadone. Of particular interest is azoxystrobin. Azoxystrobin is also described as entry 47 in The Pesticide Manual, Thirteenth Edition, published by The British Crop Protection Council, 2003. Picoxystrobin is also described in the Pesticide Manual as entry 647.

In a further embodiment said fungicide is selected from the group consisting of: Azoxystrobin; Thiabendazole; Fludioxonil and a mixture thereof.

Fludioxonil is listed as entry 368 The Pesticide Manual, Fludioxonil is mainly known as a fungicide for use on crops and also as a seed treatment. Thiabendazole is listed as entry 790.

In a further embodiment said azoxystrobin, thiabendazole and fludioxonil are present in amounts which provide a synergistic effect.

In a still further embodiment said azoxystrobin and thiabendazole are present in amounts which provide a synergistic effect.

In a still further aspect of the invention there is provided a micro fibre which comprises a fungicidally effective amount of (a) a strobilurin or strobilurin-type fungicide and (b) a fungicide selected from the group consisting of: (bi) thiabendazole; (bii) fludioxonil or a combination thereof, wherein the fungicides are present in synergistic amounts. In a particular embodiment said strobilurin fungicide is azoxystrobin.

The microfibres according to the invention may comprise a single active ingredient or a combination of active ingredients. Where the fibres contain a single active ingredient, they may be mixed with other microfibres containing a different active ingredient to generate a mixture of fibres containing the different active ingredients. The microfibres may be combined with one or more additives to improve particular properties (for example distribution on surfaces). Such additives are well known to the person skilled in the art. These may be blended with other bio-enhancing adjuvants (ingredients which may aid or modify the action of the active ingredient used in the micro fibres of the invention).

Examples of other fungicides which may be used in accordance with the present invention include:

AC 382042 (N-(I -cyano-l,2-dimethylpropyl)-2-(2,4-dichlorophenoxy) propionamide), acibenzolar-S-methyl, alanycarb, aldimorph, anilazine, azaconazole, azafenidin, benalaxyl, benomyl, benthiavalicarb, biloxazol, bitertanol, blasticidin S, boscalid (new name for nicobifen), bromuconazole, Bronopol, bupirimate, captafol, captan, carbendazim, carbendazim chlorhydrate, carboxin, carpropamid, carvone, CGA 41396, CGA 41397, chinomethionate, chlorbenzthiazone, chlorothalonil, chlorozolinate, clozylacon, copper containing compounds such as copper oxychloride, copper oxyquino- late, copper sulphate, copper tallate, and Bordeaux mixture, cyamidazosulfamid, cyazofamid (IKF-916), cyflufenamid, cymoxanil, cyproconazole, cyprodinil, debacarb, di-2-pyridyl disulphide l,l'-dioxide, dichlofluanid, diclocymet, diclomezine, dicloran, diethofencarb, difenoconazole, difenzoquat, diflumetorim, diiodomethyl-p-tolylsufone (Amical, from Dow) O, O-di-ώo-propyl-S-benzyl thiophosphate, dimefluazole, dimetconazole, dimethirimol, dimethomorph, dimoxystrobin, diniconazole, dinocap, di- thianon, Dithiocarbamates, dodecyl dimethyl ammonium chloride, dodemorph, dodine, doguadine, edifenphos, epoxiconazole, ethaboxam, ethirimol, ethyl (Z)-Λ/-benzyl-

N([methyl(methyl-thioethylideneaminooxycarbonyl)amino]thio)-β-alaninate, etridiazole, famoxadone, fenamidone, fenarimol, fenbuconazole, fenfuram, fenhexamid, fenoxanil (AC 382042), fenpropidin, fenpropimorph, fentin acetate, fentin hydroxide, ferbam, ferimzone, fluazinam, flumetover, flumorph, fluoroimide, fluoxastrobin, fluquinconazole, flusilazole, flusulfamide, flutolanil, flutriafol, folpet, fosetyl-aluminium, fuberidazole, furalaxyl, furametpyr, guazatine, hexaconazole, hydroxyisoxazole, hymexazole, imazalil, imibenconazole, iminoctadine, iminoctadine triacetate, 3-iodo-2-propynyl butylcarbamate (IBPC), ipconazole, iprobenfos, iprodione, iprovalicarb, isopropanyl butyl carbamate, isoprothiolane, kasugamycin, kresoxim-methyl, LYl 86054, LY211795, LY 248908, mancozeb, maneb, MBT mefenoxam, mepanipyrim, mepronil, metalaxyl, metalaxyl M, metconazole, metiram, metiram-zinc, metominostrobin, metrafenone, MON65500 (N-allyl-4,5-dimethyl-2-trimethylsilylthiophene-3-carboxamide), myc- lobutanil, NTN0301, neoasozin, nickel dimethyldithiocarbamate, nitrothale-isopropyl, nuarimol, 2-0-octyl-4-isothiazolin -3-one (Skane M 8 Rohm& Hass), ofurace, organomercury compounds, orysastrobin, oxadixyl, oxasulfuron, oxolinic acid, oxpoconazole, oxycarboxin, pefurazoate, penconazole, pencycuron, phenazin oxide, phosphorus acids, phthalide, picoxystrobin, polyoxin D, polyram, probenazole, prochloraz, procymidone, propamocarb, propamocarb hydrochloride, propiconazole, propineb, propionic acid, proquinazid, prothioconazole, pyraclostrobin, pyrazophos, Sodium and Zinc Pyrithione (Omadine chemistry from Arch Chem.), pyrifenox, pyrimethanil, pyroquilon, pyroxyfur, pyrrolnitrin, quaternary ammonium compounds, quinomethionate, quinoxyfen, quintozene, silthiofam (MON 65500), S-imazalil, simeconazole, sipconazole, sodium pentachlorophenate, spiroxamine, streptomycin, sulphur, tebuconazole, tecloftalam, tecnazene, tetraconazole, thifluzamide, 2-(thiocyano- methylthio)benzothiazole, thiophanate-methyl, thiram, tiadinil, timibenconazole, tolclofos-methyl, tolylfluanid, triadimefon, triadimenol, triazbutil, triazoxide, tricyclazole, tridemorph, trifloxystrobin, triflumizole, triforine, triticonazole, validamycin A, vapam, vinclozolin, XRD-563, zineb, ziram, zoxamide and compounds of the formulae:

Examples of insecticides which may be used in accordance with the present invention include: a) Pyrethroids, such as permethrin, cypermethrin, fenvalerate, esfenvalerate, deltamethrin, cyhalothrin (in particular lambda-cyhalothrin), bifenthrin, fenpropathrin, cyfluthrin, tefluthrin, fish safe pyrethroids (for example ethofenprox), natural pyrethrin, tetramethrin, s-bioallethrin, fenfluthrin, prallethrin or 5-benzyl-3-furylmethyl-(E)-(lR,3S)-2,2-dimethyl- 3-(2-oxothiolan-3-ylidenemethyl)cycl opropane carboxylate; b) Organophosphates, such as, profenofos, sulprofos, acephate, methyl parathion, azinphos-methyl, demeton-s-methyl, heptenophos, thiometon, fenamiphos, monocrotophos, profenofos, triazophos, methamidophos, dimethoate, phosphamidon, malathion, chlorpyrifos, phosalone, terbufos, fensulfothion, fonofos, phorate, phoxim, pirimiphos-methyl, pirimiphos-ethyl, fenitrothion, fosthiazate or diazinon; c) Carbamates (including aryl carbamates), such as pirimicarb, triazamate, cloethocarb, carbofuran, furathiocarb, ethiofencarb, aldicarb, thiofurox, carbosulfan, bendiocarb, fenobucarb, propoxur, methomyl or oxamyl; d) Benzoyl ureas, such as diflubenzuron, triflumuron, hexaflumuron, flufenoxuron or chlorfluazuron; e) Organic tin compounds, such as cyhexatin, fenbutatin oxide or azocyclotin; f) Pyrazoles, such as tebufenpyrad and fenpyroximate; g) Macrolides, such as avermectins or milbemycins, for example abamectin, emamectin benzoate, ivermectin, milbemycin, spinosad or azadirachtin; h) Hormones or pheromones; i) Organochlorine compounds such as endosulfan, benzene hexachloride, DDT, chlordane or dieldrin; j) Amidines, such as chlordimeform or amitraz; k) Fumigant agents, such as chloropicrin, dichloropropane, methyl bromide or metam;

1) Chloronicotinyl compounds such as imidacloprid, thiacloprid, acetamiprid, nitenpyram or thiamethoxam; m) Diacylhydrazines, such as tebufenozide, chromafenozide or methoxyfenozide; n) Diphenyl ethers, such as diofenolan or pyriproxifen; o) Indoxacarb; p) Chlorfenapyr; q) Pymetrozine; r) Spirotetramat, Spiromesifen; or s) Flubendiamid or Rynaxypyr.

Examples of herbicides which may be used in accordance with the present invention include:

2,3,6-TBA; 2,4-D; 2,4-DB; acetochlor; acifluorfen-sodium; aclonifen; acrolein; alachlor; alloxydim; ametryn; amicarbazone; amidosulfuron; aminopyralid; aminotriazol; amitrole ammonium sulfamate; anilofos; asulam; atrazine; aviglycine; azafenidin; azimsulfuron; BAY FOE 5043; beflubutamid; benazolin; bencarbazone; benfluralin; benfuresate; bensulfuron-methyl; bensulide; bentazone; benzfendizone; benzobicyclon; benzofenap; bialaphos; bifenox; bispyribac-sodium; borax; bromacil; bromobutide; bromophenoxim; bromoxynil; butachlor; butafenacil; butamifos; butralin; butroxydim; butylate; cafenstrole; carbetamide; carfentrazone-ethyl; chloransulam methyl; chlorbromuron; chlorflurenol-methyl; chloridazon; chlorimuron-ethyl; chloroacetic acid; chlorotoluron; chlorpropham; chlorsulfuron; chlorthal-dimethyl; cinidon-ethyl; cinmethylin; cinosulfuron; clefoxydim profoxidim; clethodim; clodinafop-propargyl; clomazone; clomeprop; clopyralid; cloransulam; cloransulam-methyl; cumuluron; cumyluron; cyanamide; cyanazine; cyclanilide; cycloate; cyclosulfamuron; cycloxydim; cyhalofop; cyhalofop-butyl; cyprosulfamide; daimuron; dalapon; dazomet; desmedipham; desmetryn; dicamba; dichlobenil; dichlorprop; dichlorprop-P; diclo fop-methyl; diclosulam; difenzoquat metilsulfate; diflufenican; diflufenzopyr; dimefuron; dimepiperate; dimethachlor; dimethametryn; dimethenamid; dimethenamid-P; dimethipin dimethylarsinic acid; dinitramine; dinoterb; diphenamid; dipropetryn; diquat dibromide; dithiopyr; diuron; DNOC; DSMA; endothal; EPTC; esprocarb; ethalfluralin; ethametsulfuron-methyl; ethephon; ethofumesate; ethoxyfen-ethyl; ethoxysulfuron etobenzanid; fenclorim; fenoxaprop-P-ethyl; fentrazamide; ferrous sulfate; flamprop; flamprop-M; flazasulfuron; florasulam; fluazifop-butyl; fluazifop-P -butyl; fluazolate; flucarbazone sodium; flucetosulfuron; fluchloralin; flufenacet; flufenpyr-ethyl; flumetralin; flumetsulam; flumiclorac-pentyl; flumioxazin; flumipropin; fluometuron; fluoroglycofen-ethyl; fluoxaprop; flupoxam; flupropacil; flupropanate; flupyrsulfuron- methyl-sodium; flurenol; fluridone; flurochloridone; fluroxypyr; flurtamone; fluthiacet- methyl; fluxofenim; fomesafen; foramsulfuron; fosamine; glufosinate-ammonium; glyphosate; halosulfuron-methyl; haloxyfop; haloxyfop-P; HC-252; hexazinone; imazamethabenz-methyl; imazamox; imazapic; imazapyr; imazaquin; imazethapyr; imazosulfuron; indanofan; iodosulfuron; iodosulfuron-methyl-sodium; ioxynil; isopropazol; isoproturon; isouron; isoxaben; isoxachlortole; isoxadifen; isoxaflutole;

Isoxapyrifop; karbutylate; KIH-485; lactofen; lenacil; linuron; MCPA; MCPA-thioethyl;

MCPB; mecoprop; mecoprop-P; mefenacet; mefenpyr diethyl; mefluidide; mesosulfuron methyl; mesotrione; metam; metamifop (mefluoxafop); metamitron; metazachlor; methabenzthiazuron; methazole; methyl isothiocyanate; methylarsonic acid; methyldymron; metobenzuron; metobromuron; metolachlor; metosulam; metoxuron; metribuzin; metsulfuron-methyl; MK-616; molinate; mono linuron; MSMA; naproanilide; napropamide; naptalam; NDA-402989; neburon; nefenacet; nicosulfuron; nipyraclofen; n-methyl-glyphosate; nonanoic acid; norflurazon; oleic acid (fatty acids); orbencarb; orthosulfamuron; oryzalin; oxaciclomefone; oxadiargyl; oxadiazon; oxasulfuron; oxaziclomefone; oxyfluorfen; paraquat dichloride; pebulate; pendimethalin; penoxsulam; pentachlorophenol; pentanochlor; pentoxazone; pethoxamid; petrolium oils; phenmedipham; phenoxaprop-P-ethyl (R); picloram; picolinafen; pinoxaden; piperophos; pretilachlor; primisulfuron; primisulfuron-methyl; procarbazone; prodiamine; profluazol; profoxydim; prohexcadion calcium; prometon; prometryn; propachlor; propanil; propaquizafop; propazine; propham; propisochlor; propoxycarbazone; propoxycarbazone-sodium; propyzamide; prosulfocarb; prosulfuron; pyraclonil; pyrazogyl; pyraflufen-ethyl; pyrasulfotole; pyrazolynate; pyrazosulfuron-ethyl; pyrazoxyfen; pyribenzoxim; pyributicarb; pyridafol; pyridate; pyriftalid; pyriminobac- methyl; pyrimisulfan; pyrithiobac-sodium; quinclorac; quinmerac; quinoclamine; quizalofop; quizalofop-P; rimsulfuron; sequestren; sethoxydim; siduron; simazine; simetryn; S-metolachlor; sodium chlorate; sulcotrione; sulfentrazone; sulfometuron- methyl; sulfosate; sulfosulfuron; sulfuric acid; tar oils; TCA-sodium; tebutam; tebuthiuron; tefuryltrione; tembotrione; tepraloxydim; terbacil; terbumeton; terbuthylazine; terbutryn; thenylchlor; thiazafluron; thiazimin; thiazopyr; thiencarbazone; thifensulfuron-methyl (thiameturon-methyl); thiobencarb; tiocarbazil; topramezone; tralkoxydim; tri-allate; triasulfuron; triaziflam; tribenuron-methyl; triclopyr; trietazine; triflosulam; trifloxysulfuron; trifloxysulfuron-sodium; trifluralin; triflusulfuron-methyl; trinexapac-ethyl; tritosulfuron; and urea sulfate.

The present invention still further provides a method of reducing the amount of an active ingredient in effluent generated during the manufacturing process of a material comprising cellulose, the manufacturing process comprising the steps of: (a) adding an active ingredient to the process water; (b) mixing said process water with said material; (c) allowing the active ingredient to associate with said material; (d) extracting the process water from the resulting material; characterised in that the active ingredient is associated with a non cellulose microfibre. Thus, when the microfϊbres of the invention are added during the manufacturing process of the material comprising cellulose, incorporation of the micro fibres into the material means that less active ingredient remains in the process water. The present invention still further provides a method as described above wherein said material is paper.

The present invention still further provides a method as described above wherein some of said microfibres connect to form a fibrous mesh.

The present invention still further provides a method as described above wherein said microfibres are substantially rod shaped.

The present invention still further provides a method as described above wherein said microfibres are added to at least the top ply of the paper during the paper manufacturing process. In a further embodiment said microfibres are in at least the top and second plies of the paper. In a still further embodiment said microfibres are in each of the plies of the paper.

The present invention still further provides a method as described above wherein said microfibres are added to at least one of the following systems or process intermediates: the thick stock; the thin stock; the water supply; the papermaking stock tank; pulp refiner; stock chest; flow box; furnish and wet-lap during the papermaking process. The microfibres according to the invention may be added to any convenient stage and time during the paper making process.

The present invention still further provides a material comprising cellulose which material additionally comprises non cellulose microfibres which comprise an active ingredient. In a particular embodiment said ingredient is a fungicide. In a further embodiment said material is paper.

The present invention still further provides paper containing non-cellulosic microfibres which comprise a fungicidally active compound. In a particular embodiment said fungicide is selected from the group consisting of: Azoxystrobin; Thiabendazole; Fludioxonil and a mixture thereof. In a still further embodiment said paper comprises Azoxystrobin and Thiabendazole. In a still further embodiment said paper comprises Azoxystrobin, Thiabendazole and Fludioxonil. The present invention still further provides a wallboard comprising paper as described above. Wallboard (also sometimes known as drywall or plasterboard) is a building material commonly used to make the internal dividing walls of buildings. Buildings include residential buildings such as houses and flats and commercial buildings such as shops, warehouses, hotels and factories and the like, also institutional buildings such as colleges. Wallboard includes ceiling board which is material used for internal ceilings. Wallboard is generally in the form of a flat sheet between 0.5 and 2 cm thick and comprises, usually, a gypsum core, usually coated on both sides, with paper. Wallboard is usually fixed to a wooden frame to form an internal wall, or fixed to ceiling spars to form an internal ceiling. Wallboard has many desirable properties, such as being relatively light and easy to cut, and having a surface that is easily decorated with paint or wallpaper. The microfibres according to the invention may be included in the paper of the wallboard, in the core of the wallboard, such as the gypsum core or both the paper and the core. Preferably the fungicide/fungicides is/are present (within the microfibres) in the wallboard or paper coating in concentrations of about 50ppm to 5000ppm, more preferably from 1100 to 1300ppm in the paper.

The present invention still further provides a building comprising a wallboard as described above. In a particular embodiment said building is a temporary building. In a further embodiment said building is a permanent structure. In a still further embodiment said building comprises a plurality of wallboards as described above.

The present invention still further provides a composition for use in a method as described above which composition comprises a dispersion of non cellulose microfibres which comprise an active ingredient in a liquid. In a particular embodiment said liquid is water.

The present invention still further provides a fibrous mesh which comprises non cellulose microfibres which comprise an active ingredient. In a particular embodiment said ingredient is a fungicide. The present invention still further provides the use of a non cellulose micro fibre which comprises an active ingredient in the manufacture of a material which comprises cellulose. In a particular embodiment said micro fibre is used in the manufacture of paper.

The micro fibres of the invention which contain a fungicide may be used in the prevention and/or treatment of growth of a number of fungi including the following: Alternaria alternata, Aspergillus flavus, Aspergillus terreus, Aspergillus fumigatus, Aspergillus repens, Aspergillus versicolor, Candida albicans, Chaetomium globosum, Cladosporium cladosporioides, Cladosporium herbarum, Cladosporium sphaerospermum, Coniophora puteana, Curvularia genticulata, Diplodia natalensis, Epidermophyton floccosum, Fusarium oxysporum, Gliocladium virens, Gloeophyllum trabeum, Humicola grisea, Lecythophora mutabilis, Lentinus cyathiformis, Lentinus lepidus, Memnionella echinata, Mucor indicus, Mucor racemosus, Oligoporus placenta, Paecilomyces variotii, Penicillium citrinum, Penicillium funiculosum, Penicillium ochrochloron, Penicillium purpurogenum, Penicillium pinophilum, Penicillium variabile, Petriella setifera,

Phanerochaete chrysosporium, Phoma violacea, Poria placenta, Rhodotorula rubra, Schizophyllum commune, Sclerophoma phytiophila Scopulariopsis brevicaulis, Serpula lacrymans, Sporobolomyces roseus, Stemphylium dendriticum, Trichophyton mentagrophytes, Trichurus spiralis, Trichophyton rubrum, Ulocladium atrum and Ulocladium chartarum.

It is particularly preferable to generate microfibres containing a fungicide for incorporation into a material, which fungicides are effective against the following fungi: Alternaria alternata, Alternaria tenuissima, Aspergillus niger, Aspergillus versicolor, Aureobasidium pullulans, Chaetomium globosum, Cladosporium cladosporioides, Coniophora puteana, Gloeophyllum trabeum, Memnionella echinata, Mucor indicus, Oligoporus placenta, Penicillium citrinum, Penicillium chrysogenum, Penicillium funiculosum, Penicillium pinophilum, Sclerophoma phytiophila, Stachybotrys atra, Stachybotrys chartarum, and Ulocladium chartarum. The invention will now be described with reference to the following examples:

EXAMPLES

Example 1 (non-aqueous solvent system)

324 g of epoxy resin SU-8 was dissolved in ethyl lactate. To this solution were added 72.9g of azoxystrobin, 7.29 g of fludioxonil and 72.9 g of thiabendazole. The first two active ingredients went fully into solution while the latter active ingredient remained partly as a fine particulate suspension. A microfibre suspension was prepared by adding 109 g of this solution to 5050 g of glycerin under vigorous agitation.

Example 2 (paper preparation)

A laboratory hand sheet sample was prepared using a conventional Britt jar by adding

300 g of 1% DLK paper fibre thin stock, then 1 g of 0.41 wt% alum, then 1 g of 0.41 wt% ASA size emulsion, then 1 g of 0.08 wt% retention aid, then 2.2 g of a microfibre suspension prepared according to the method of example 1. The effluent collected during formation of the hand sheet contained no detectable residue (< 0.5 ppm) of the three active ingredients present in the microfibre suspension. The hand sheet was inoculated with stock cultures of Aspergillus niger (ATCC6275), Stachybotrys chartarum (ATCC 16026), Penicillium citrinum (ATCC 9849) and Chaetomium globosum (ATCC 6205), then placed in an incubation chamber. After 4 weeks there was no detectable mould growth.

Example 3 (water-based solvent system) 2 g of polymethylmethacrylate was dissolved in 18 g of acetone. To this solution was added 0.2 g each of thiabendazole and azoxystrobin, and 0.02 g of fludioxonil. A microfibre suspension was prepared by adding 20 g of this suspension to 1500 mL of water under vigorous agitation.

Example 4 (filter cake product)

A microfibre preparation prepared according to the method of example 3 was concentrated by vacuum filtration on a paper filter disk in a conventional Buchner funnel. The microfϊbres could be re-dispersed into an aqueous dispersion by stirring the filter cake vigorously into water.

Example 5 (generation of micro fibres without active ingredient)

50% solution of Epoxy resin SU-8 with carbon black powder was dissolved in gamma- butyrolactone to generate a first solution. Carbon black was added as a tool to facilitate direct visualisation of the micro fibres, but microscopic inspection is also effective to evaluate the compositions. The following table illustrates the solvent systems that have been used to generate micro fibres when an amount of the first solution was mixed with the dispersing medium as indicated below:

Example 6 (generation of microfibres by injecting a jet of fluid into extensional flow deformation) 7.6 g of epoxy resin SU-8 was dissolved in 11.5 g of gamma butyrolactone. To this solution were added 0.56g of azoxystrobin, 0.11 g of fludioxonil and 0.56 g of chlorothalonil. The first two active ingredients went fully into solution while the latter active ingredient remained partly as a fine particulate suspension, which upon warming was only slightly turbid. A micro fibre suspension was prepared by adding 0.81 g of this solution to 61 g of propylene glycol. The addition was performed by pumping the solution through a tube ending in a hypodermic needle placed below the surface of the propylene glycol, and during the addition process the propylene glycol was stirred vigorously so that the incoming solution stream was continuously stretched by the strong extensional flow deformation and the epoxy resin and active ingredients were precipitated into microfibres.

Claims

1. A method for generating non cellulose micro fibres comprising an active ingredient, comprising:

(a) generating a solution (1) which comprises dissolved polymer and/or polymerisable or cross-linkable monomers and dissolved and/or dispersed active ingredient in a first solvent; and

(b) adding said solution to a further solvent or mixture of solvents (2) wherein said polymer, monomers and said active ingredient are substantially insoluble in said further solvent or solvents; and

(c) precipitating the polymer and optionally the monomers from the solution wherein said active ingredient is substantially confined within the precipitate.

2. A method according to claim 1 wherein at least 75% of the active ingredient is confined within the precipitate.

3. A method according to claim 1 or claim 2 wherein the precipitate is constituted substantially by polymerised monomers.

4. A method according to claim 2 or claim 3 wherein polymerisation of the monomers in the micro fibres is further facilitated via UV light and/or reaction at elevated temperature.

5. A method according to any one of claims 1 to 4 wherein a polyfunctional amine is added to further facilitate polymerisation of said monomers in the micro fibres.

6. A method according to any one of claims 2 to 5 wherein said further solvent further facilitates polymerisation of said monomers in the micro fibres.

7. A method for generating non cellulose micro fibres comprising an active ingredient said method comprising: (a) generating a solution (1) by dissolving and/or dispersing an active ingredient in a first solvent which comprises dissolved polymer and/or polymerisable or cross-linkable monomers;

(b) mixing said solution with a further solvent or mixture of solvents (2) to produce a further solution wherein said polymer and monomers and said active ingredient are substantially insoluble in said further solvent or solvents;

(c) precipitating said polymer and optionally the monomers into micro fibres which confine said active ingredient.

8. A method according to any one of claims 1 to 7 wherein the interfacial tension between said polymer and said further solvent is sufficient to ensure that once formed the micro fibres retain an average length from about 0.1 microns to about

5000 microns.

9. A method according to any one of claims 1 to 8 wherein said first solvent and said further solvent or solvents are fully miscible.

10. A method according to any one of claims 1 to 9 wherein said micro fibres are harvested from said further solution.

11. A method for manufacturing a material which comprises cellulose which material additionally comprises non cellulose microfibres comprising an active ingredient, comprising:

(a) generating non cellulose microfibres which comprise an active ingredient and

(b) adding said microfibres to a material which comprises cellulose.

12. A method of preventing or reducing fungal infestation of a material comprising cellulose comprising the steps of: (a) generating non cellulose microfϊbres which comprise a fungicide; and

(b) adding said microfϊbres to a material comprising cellulose.

13. A method for increasing the retention of an active ingredient in a material which comprises cellulose said method comprising providing non cellulose microfϊbres which comprise said ingredient and adding said microfϊbres to said material or a precursor thereof.

14. A method according to any one of claims 1 to 13 wherein said active ingredient is selected from the group consisting of: fungicide, herbicide, insecticide, molluscicide; arachnidicide; nematicide, bactericide and viricide.

15. A method according to claim 14 wherein said ingredient is a fungicide.

16. A method according to claim 14 or claim 15 wherein said fungicide is selected from the group consisting of: Azoxystrobin; Thiabendazole; Fludioxonil and a mixture thereof.

17. A method of reducing the amount of an active ingredient in effluent generated during the manufacturing process of a material comprising cellulose, the manufacturing process comprising the steps of:

(a) adding an active ingredient to the process water;

(b) mixing said process water with said material;

(c) allowing the active ingredient to associate with said material;

(d) extracting the process water from the resulting material;

characterised in that the active ingredient is associated with a non cellulose microfϊbre.

18. A method according to any one of claims 11 to 17 wherein said material is paper.

19. A method according to any one of claims 1 to 18 wherein some of said microfϊbres connect to form a fibrous mesh.

20. A method according to any one of claims 1 to 19 wherein said micro fibres are substantially rod shaped.

21. A method according to any one of claims 11 to 20 wherein said micro fibres are added to at least the top ply of the paper during the paper manufacturing process.

22. A method according to any one of claims 18 to 21 wherein said micro fibres are added to at least one of the following systems or process intermediates: the thick stock; the thin stock; the water supply; the papermaking stock tank; pulp refiner; stock chest; flow box; furnish and wet-lap during the papermaking process.

23. A material comprising cellulose which material additionally comprises non cellulose microfϊbres which comprise an active ingredient.

24. A material according to claim 23 wherein said ingredient is a fungicide.

25. A material according to claim 23 or claim 24 which is paper.

26. Paper containing non-cellulosic micro fibres which comprise a fungicidally active compound.

27. Paper according to claim 25 or claim 26 wherein said fungicide is selected from the group consisting of: Azoxystrobin; Thiabendazole; Fludioxonil and a mixture thereof.

28. Paper according to claim 27 which comprises Azoxystrobin and Thiabendazole.

29. Paper according to claim 27 or claim 28 which comprises Fludioxonil.

30. A wallboard comprising paper according to any one of claims 25 to 29.

31. A composition for use in a method of any one of claims 11 to 22 which comprises a dispersion of non cellulose micro fibres which comprise an active ingredient in a liquid.

32. A composition according to claim 31 wherein said liquid is water.

33. A fibrous mesh which comprises non cellulose micro fibres which comprise an active ingredient.

34. A fibrous mesh according to claim 33 wherein said ingredient is a fungicide.

35. Use of a non cellulose micro fibre which comprises an active ingredient in the manufacture of a material which comprises cellulose.

36. Use of a non cellulose micro fibre which comprises a fungicide in the manufacture of paper.

37. A method according to any one of claims 1 to 10 wherein solution (1) is injected into the solvent or mixture of solvents (2) or vice versa.