US2663696A

US2663696A - Textile printing emulsions comprising thermoplastic resin latices dispersed in solutions of thermosetting resins in organic solvents

Info

Publication number: US2663696A
Application number: US204491A
Authority: US
Inventors: Edward F Armatys
Original assignee: Sun Chemical Corp
Current assignee: Sun Chemical Corp
Priority date: 1951-01-04
Filing date: 1951-01-04
Publication date: 1953-12-22
Anticipated expiration: 1970-12-22

Description

Patented Dec. 22, 1953 IN G THERMOPLASTIC RESIN LATICES DISPERSED IN SOLUTIONS OFTHERMO- SETTING RESINS IN ORGANIC SOLVENTS Edward F. Armatys, New York, N. Y., assignor to Sun Chemical Corporation, Long Island City, N. Y., a corporation of Delaware No Drawing. Application January 4, 1951,

Serial No. 204,491" 6 Claims. (01. 26029.4)

The present invention relates to coloring compositions for textile materials, and relates more particularly to pigmented emulsions especially adapted for imprinting textile fabrics.

The art of decorating and coloring textile fabrics by printing processes was formerly restricted almost completely to the use of various dyestuff .materials. However, due to the high cost of many dyes, the involved and rather expensive processes required to imprint and fix the dyes upon the fabrics, the lack of clarity or sharpness of line in the finished print, and the deficiencies of many dyestuffs as regards light fastness, resist- .ance to washing, etc., it was sought to employ the less costly and more light fast insoluble pig- 'ment materials as the coloring matter in coloring compositions fabrics.

7 However, the use of such coloring materials for textile printing presented many new problems not encountered in the use of dyestuffs. Since pigments, unlike dyestuffs, are insoluble materials and have no afiinity for textile fabrics, it is necessuitable for imprinting textile sary that these materials be employed in printing compositions which contain therein a material which has the ability to adhere to the fibers of textile fabrics and which, in the presence of pigmentmaterials, acts so as to bind the pigment particles to the said fibers. It was therefore attempted to imprint fabrics with printing compositions containing pigment materials dispersed in a solution, in a sutable solvent therefor, of a film forming resinous material, the solvent usually being of such character as to be readily removable from the imprinted fabric as by rapid evaporation thereof. Such coloring systems, however, were found to be unsuitable as printing compositions for textile materials since they adversely affected the character of the fabric by cementing the fibers together and, in many cases, by filling in the interstices between the fabric fibers with a solid film of binder and pigment, thereby impart ing an undesirable stiffness and harshness of feel to the fabric. Further, prints made with such printing compositions were not too resistant towards the action of various dry cleaning fluids customarily employed in such cleaning opera tions.

The deficiencies present in the imprinted fabric occasioned by the use of such pigmented printing compositions as above described has been largely overcome by the use, as printing compositions for textile materials, of pigmented emulsions containing film forming resinous materials as the binder component thereof, which resinous materials are characterized by their abiilty to set to a.

' solvent insoluble condition by a suitable thermal treatment. These compositions are usually made and employed in the form of water-in-oilor oil in-water emulsions, the oil phase generally comprising a pigmented solution or dispersion of a film forming thermosetting resinous material in solvents substantially immiscible with water' Since these compositions are applied to textile fabrics in'the form of an emulsion, the resinous binder material which carries the pigment is deposited upon the fabric in the form of a disco: tinuous film, so that instead of completely covering the fabric structure with a continuous film of binder-and pigment, only the individual fibers which make up the fabric structure are found to .be coated with a film of binder and pigment.

Upon application of such pigmented emulsions to textile fabrics by the conventional printing pro cesses, and upon subsequent treatment of the imprinted fabrics at temperatures sufiicient to effect setting of the resinous binder material upon the fabric to a solvent insoluble condition, a printed fabric is obtained which is lacking in the stiffness obtained by the use of pigmented resin solutions alone and which has a hand or feel to the touch substantially the same as the unprinted fabric.

However, fabrics printed or colored with such pigmented emulsions usually had one deficiency which caused serious concern among textile printers. This is the effect known as crocking, or the tendency of the color of the printed fabric to rub off onto other materials, such as other fabrics, when. a sliding contact is made therebetween. As is evident, this is a highly objectionable characteristic in colored fabrics since in washing and cleaning operations, or even in ordinary use, such .fabrics would tend to discolor other fabrics which came into contact therewith. Since such condition in the imprinted fabric tended to offset the advantages derived from the use of such pigmented emulsions as printing and coloring compositions for textile materials, it was desired to eliminate this condition as far as possible without sacrificing any of the other advantagesobtained by the use thereof. a I

By the present invention there are provided pigmented emulsions especially adapted for imprinting and coloring textile materials by the conventional printing processes employed in the textile industry whereby crocking in the finished print is substantially eliminated. The use of the pigmented emulsions of the present invention in the printing of fabrics does not materially change the hand of the fabric imprinted, nor does it cause any stiifeningroraexcess. weightingctin the' pninted fabric. n when the imprinted fabriczissubjected to a subsequent thermal treatment as hereinafter set forth, the imprinted fabric is highly resistant toward fading or discolorationaafor examplaby the loss of pigment due to theefliectc'of .or laundering operations thereongt-omdue to"the.ef-: f ect which the solvents ordinarilyzemployed indry cleaning operations may have upon the fabric.

The textile printing comDOSitionspfthe present invention are pigmented- -water-=in oil emulsions in which the discontinuous or aqueous" phase comprises a latex of arsynthetic-ithermoplastic resinous material, and in which thereontinuous or oil phase comprises a solution of ..a thermosetting resinous .material in organic 's'ol vents which are substantially non-solvents for I the "resinous materials ofthe' aqueous phase'f the said emulsion also containing a :pla'sticizer" for 'the resinous material of theaqueous phase in certain definite proportions as -hereinafter outlined.

The r term latex as employed in the present invention refers to stable colloidal dispersions or a thermoplastic resinous-material in water, the dispersed resin -being 'present 'therein in thefor-m 'of'finely divided discrete particles. The resins which-have been' 'found to'-be= particularly useful in providing the textile printing compositions of 1 the present-invention whenemployed in" the form ofa" 'latex are the polymers of 'v-inylchloride; the

copolymers 'of' vin'ylchloride and vin'yl acetate, and the copolymers of vinylidene chlo'rideand acrylonitrile.

Themost satisfactory 'biiider materials 'elfor utilization as the binder=material=of the oil phase of theemulsions--'of= the present invention are "thealcoholated 'melamine formaldehyde thermosetting resinous condensates whichmomprise the reaction-product of mela-mine, formaldehyde and an alcohol such as 'butyl alcohol or cap yl alcohol,

-' reacted to' a point *where'thecondensate is-soluble inorganic-solvents, or--in=mixtures thereof, such asa mixture of equal parts of mineral spirits and butyl alcohol. Also-suitableforsuch use are .alkyd modified melamine-formaldehyde thermo- 'setting resinous condensates, asfor example, a melamine-formaldehyde resinous =-condensate -mo'dified with a drying oil-'modified-"glycerol- "phthalate-resin.

"The, solvent medium ofithe oiljphasc of-the printing emulsions -of the-present'invention may comprise any of the ordinary-hydrocarbon sol- "vents; both aliphaticand aromatic; and also 1 any of "the common terpene solvents, and usually .comprises mixturesof these slvents= t0gether with certain of the lower aliphatic-alcohols' since the? thermosetting-resinous materials' mentioned above are usually provided and-employed as-solutions' of the resins in-mixturespf either aliphatic or aromatic solvents with various *alcohols such asbutanol'or caprylalcohol.

"The 'plasticizers-'...for the resinous material of the: aqueous; 'phase ,of' the emulsions are nonvolatile liquid -brganic-compounds which are im- "miscible 'with'water and-generally-miscible with .the common organic solvents-andthinners employed in the emulsions of the present invention. Examples of plasticizers which may be employed in the compositions of the present invention, are tricresyl phosphate, triphenyl phosphate, dibutyl 5 phthalate, dioctyl phthalate and dibutyl sebacate.

The plasticizers are employed in the compositions of the present invention in certain definite amounts such amounts being based upon the ramount of resinous material presentfin the aqueld-oous phase. of the emulsion. For best results, the plasticizer is employed in the ratio of from -.i .approximately one to approximately two parts -by weight of .plasticizer to approximately one part kbyiweightofthe resinous material of the aqueous ;il5 .;-.phaseathatiis theresinous material of the latex Jdispersion. .T'Thense of plasticizer in amounts substantially beyond the limits specified has an :eadverse effect -uponthe end results obtained in the finished "product, too small an amount of 'plasticizer-resulting in a rather stiff and brittle .xzfilrn of .-.-binder .and pigment, and too large an amount of plasticizer providing a binder-pigment film which is too soft to prevent rub-off of the pigment particles from the imprinted fabric.

As pigment coloring material there may be -utilizedeitherdry colors or dispersed colors; that -is,-:colorswherein the pigment has been'dispersed inza solventsuitable for use asa part of the solvent medium' of the oil phaseof the emulsion. '30 In practicing the presentinventionyit has been found that the amount of pigment coloring "material' utilized in thecompositions ofthe present .inventionfshould not exceed a ratio of approximately 1.5 parts by weight ofpigment to=onepart :by weight of combined resinous binders that-is, thex'weight of both "the thermosetting resinous binder of the .oil' phase and that of the thermoplastic: resinous material of the aqueous phase combined. '2 Further, the ratio of the thermo- "40 plastic: resinous material to "the thermosetting "resinous binder of" the oil-phase ofthe printing compositions "of I the present invention should preferably be maintained within a range'of-from approximat'elyone to approximately two parts by weight-of thesaidthermo'plastic resinous-material to :one part by-Weight of the said thermosetting-resinous binder of the oil-phase of-the emulsions.

"Improviding compositions 'in accordance with 'the' present invention, it has" been found to be completely satisfactory and economical-to, furnisha "concentrate which subsequently can -be diluted prior to use to furnish a composition'with the desired body for the particular operation by which such materials are applied to the" fabric.

In operations'where a concentrate is furnished the user may dilute such concentrate-with a-su'itable'colorless emulsion, untila composition of the necessary '7 flow properties and containing-the amountof coloring material necessary fora-particular printing operation has been obtained.

'Iherefter such printing may beeifected by utilization of 'the' equipment ordinarily-employed'in textile printing operations. When printing is completed, the coiored fabric then is treatedat elevatedtemperatures of the order of 300-35U*F. for approximately one minute to-effect removal of the volatile material present and to-complete the setting of thecoloring-material upon" the fabric.

-A colorless water-in-oil emulsion (clear) :suitable for diluting the pigment-concentrate of'the present invention, is provided as follows. A 'clear concentrateis prepared'by emulsifying'as by stirring under high speed agitation conditions,

the following materials in the proportions set forth.

Example 1 Parts by weight Drying oil-modified glycerol-phthalate resin (40% resin solids in mineral spirits) '70 Xylol 5 Ammonium sulfate Dialyzed waste sulfite liquor of U. S. P. No.

2,201,812 10 Water 5 The clear concentrate provided as in Example 1 is then diluted and emulsified with Varsol and water in the proportions set forth inExampie 2 to provide a water-in-oil emulsion suitable for diluting the pigment concentrate hereinafter set forthto the degree of printing consistency and shade of color desired.

Emample 2 Parts by weight Clear concentrate of Example 1 2.5 Varsol 22.5 Water 75.0

, since the plasticizers employed are miscible with the organic solvents constituting the oil phase of the emulsion, or the plasticizer may be present in the aqueous phase of the emulsion in dispersed form. The first form of emulsion, wherein the plasticizer constitutes a part of the oil phase, may be had by incorporating the plasticizer in the materials which constitute the oil phase of the emulsion before emulsification of the same with the latex is accomplished. The second form of emulsion, wherein the plasticizer is present in dispersed form in the aqueous phase thereof, is had when a plasticizer-water emulsion is emulsified with the remainder of the materials constituting the oil phase of pigment concentrates of the present invention.

Illustrative examples of the pigment concentrates of the present invention are given below. In preparing such concentrates, satisfactorily all of the material may be charged to a high speed mixer and agitated until the requisite dispersion and emulsiflcation is completed. To obtain the required degreeof pigment dispersion when a dry color is employed as the coloring material of the emulsion, the mixture should be passed through a roller mill or preferably be admixed and milled in a ball mill or pebble mill.

6 Example 3 Y Parts by weight Latex containing polyvinyl chloride resin solids in water) 10.0 Tricresyl phosphate 11.0

Butylated melamine-formaldehyde resinous Y condensate (50% resin solids in 25 mineral spirits, 25 butanol) 10.0 Amyl alcohol 10.0 Turpentine 46.0 Phthalocyanine blue pigment 13.0

I 100.0 Example 4 Parts by weight Latex containing a vinyl chloride-vinyl acetate copolymer, containing approx. 3% vinyl acetate (55% resin solids in water) 10.0

Dioctyl phthalate 12.0

Butylated melamine-formaldehyde resinous condensate (50% solids in 25 mineral spirits, 25 butanol) 6.0 Amyl alcohol 10.0 Turpentine 50.0 Phthalocyanine blue pigment 12.0

100.0 Example 5 1 Parts by weight Latex containing a vinylidene chloride-acrylonitrile copolymer (56% resin solids in water) 10.0

Tricresyl phosphate 5.0

Butylated melamine-formaldehyde resinous condensate 50% resin solids in 25 mineral spirits, 25 butanol) 6.0 Turpentine 67.0 Phthalocyanine blue pigment 12.0

Example 6 Parts by weight Latex containing a vinyl chloride-vinyl ace-.

tate copolymer, containing approx. 3% vinyl acetate (55% resin solids in water) 12.0 Tricresyl phosphate 7.0 Butylated melamine-formaldehyde resinous condensate (50% resin solids in 25 mineral spirits, '25 butanol) 10.0 Amyl alcohol 10.0 Turpentine 39.0 Water 10.0 Phthalocyanine blue pigment 12.0

Following the procedurehereinbefore outlined,

the pigment concentrates of the above illustra-- tive examples provide water-in-oil emulsions in which the plasticizer constitutes a part of the continuous or oil phase of the emulsion. These emulsions may be diluted to any degree desirable with the clear emulsion of Example 2 to provide the printing compositions of the present invention. 1

As stated hereinbefore, pigment concentrates of the water-in-oil typeof emulsion may be had by incorporating the plasticizer into the mixture to be emulsified in the form. of an oil-in-water emulsion. That is, an oil-in-water emulsion is prepared in which the plasticizer constitutes the dispersed or-inner phase and in which water con stitutes the outer phase. The plasticizer, inemulsion form, is then admixed with theremaindcr of the material mployed in preparing i7 the pigment concenti'msfifi the present inveniltmn' randithlgi hole is emulsified by the procedure hereinbtiforemiitlinediior preparingirhesaid conwbhtrates. .Bythimmethdfi the lplastioizeri rei m'ainsdispersed inthe wateriphase' of the'finished-seniulsion,

Impneparing a pig'mentmonc'e'ritrate of the :type eeiliova described, -a. .plastieizerrsemulsion :is :first fi-prepared. .A. plasticizers emulsion suitable for ease in. the. pigment. concentrates oi -the. present" ailrvention is. pr.epared,:=foraexample by. mixing, "under high speed agitation conditions, a solution eon-T125 parts by weight of oleic acid in 65 parts by weight of dioctyl phtha-late with a solution of 10. 2,fiepartaby weight of ammonia in 33 parts byweight f -water. resultant f product is an oil-in water'remu-lsion in which the splasticizer ;,constitutes?theedispersedaphase. Such emulsion smay then be employed together-with the material set-forthinthe followingillustrative example to form as pigment-v concentrate: in accordance hwith the disclosure of the present invention.

V --Eram-ple 7 Partsby-weight tliatex ontainingpolyvinyl chlo'ride '(55 T solids in water) 10.0 fimoctyl phthalate plasticizer emulsion as described above c a 15.0 iButylatdttmelamine-formaldehyde resinousiconclensate150% fresin: solids in 25 nm'iei allispiri-tsx25 iuutanol) 5.0 filifnylalcohol 12.0 :Tiurpentine 146.0 Phthalocyanine-wbluespigment- "12.0

, "Theabove'concentrate'may also be diluted with the clear emulsion of'Example'2 to'provide" printfi'ng'compositions for textile materials having the characteristics of those of the present invention.

By the use of a latex-dispersion of the thermo- -piasticiresinous materials herein set forth as the aqueous phase =of the pigmented emulsions of the present-i1tvention; printing compositions" for texiitile materialsrarerprovided whereby crocking in l the ..finished -print is substantially eliminated. Apparently atheiuseot 'suchmaterials in the form employed'iin the compositions of the present infivention. in. someumanner 4 improves: -the' pigment sbinding properties of those .emulsion :sy'stems. Must why the latex. dispersion should h'ave' such efiect upon the finished. print may, possibly" be sexplained by the fact-that =since'the resinous ematerial of the latex dispersion is not only presoent in the printing composition in a colloidally suspended form, but is also part of the discon- Jtinuous phase of' the said compositions,-' upon --application of the 'said'printing' compositions to textile-fabrics-as by the conventional printing i=process'es; the thermoplastic resinous material is' kdeposited upon the'fabric in the form of finely idivi'cled discreteparticles interspersed throughout the plgmented' thermosetting resinous film. --It;'m'ay be that upon subsequent heat treatment of the imprinted film, the plastioizer present in sthe'imprinted film acts as a flux wherebythe disrpersed thermoplastic resin softens andflows tost'gether' to formaprotective film over or about the 1' pigment particles and the thermosetting resinous E binder materials "which bind the pigment par- .eticles'ito" the "fabric. However, such explanation -ismerelytheoretical and is not to be construed as :a teaching of theactual' manner in which the 1 improved pigment binding properties are secured i with ithe compositions of the 'pres'ent invention.

Whilthabove productsafid processesconstltute preferred embodiments of the present invention, changes may be made therein without departing from the scopetiii the present invention as defined in th appended claims.

what is'claimed is:

A coloring composition for textile materials comprising pigment-dispersed in an emulsion containing a discontinuous phase comprisingan lo aqueous colloidal dispersion of a' thermoplastic resinous material selected from thef'group "'con- '-'-sisting-of -a homopolymenofvinyl-chloride, a copol-ymer-of --vinyl--chloride-- and "vinyl acetate, "and a copolymer of vinylidene chloride and acryls' lonitrile, and a continuous phase comprising a thermosetting resinous binder selected from the group consisting. of alcoholated melamine-formaldehyde resinous condensates'and' alkyd-modified melamine-formaldehyde resinous condens'atesin' organic solvents vwhich are substantially n(in-"solvents for the resinous materiaLoff'the aqueous, phase, said emulsion containing a nonvolatile' liquid plasticizer for there'sinous material of the discontinuous phase, theratio of plas- '25 ticizer to the resinous material of said discontinuous phase being within the range of from approximately 1 to approximately 2 parts by --Weight of 'plasticizer to 1 part by Weight of said resinous-material.

2. A- colori-ng composition -for-textile m'ateri'als comprising pigment dispersed in an -emulsion containing a discontinuous phase comprising an aqueous colloidal dispersion of a homopolymer of vinyl chloride, and the continuous phase comprising a thermosetting resinous binder selected "from '1 the group consisting or alcoholated melamine-formaldehyde resinous condensates and alkyd modified melamine-formaldehyde resinous "condensates in organic solvents which are subio stantially non solventsfor the saidpolym'er of "-ti'nyl chloride; said: emulsion containing a non- -voleltile 3 liquid plasticizer for I said I polymer of 'vinyl chloride, the ratio- 0f 'plasticizer to said 'p'oly'mer of vinyl chloride being-Within the-range ftr'om approxizn'ately 1 to approximately 2 arts by-weight' of plasticizer' toone part by p 'tweight or said polymer of vinyl chloride. lk-coloring composition for textile-materials mompr'ising i pigment dispersed l in "an I emulsion 'cont'aininga discontinuous phase comprising an "aqueous-"colloidal"dispersion of a cop'olymerof "'vinylchlor'ide and vinyl acetate; and a continuous 'phase comprising a thermosetting resinous binder fi-selected from' the groupconsisting of alcoholated melamine formaldehyde resinous condensates and alkyd-modified melamine-formaldehyde resinous condensates in organic solvents Which-are '--"substantiallynon-solvents for the said copolymer of vin'yl chloride and vinyl acetate, said g eniulsion'containing a non-volatile liquid plasticizeriorsaid copolym'er or vinyl chloride and vinyl acetate, the r'atioof 'plasticizer to said co- "polymeroi vinyl chloride and'vinyl acetate being within the range of from approximately one to approximately twoparts by weight of pla'sticizer to one part by weight'of-said copolymer of vinyl chl'oride and vinyl acetate.

A coloring composition for textile materials "comprising pigment dispersed in an emulsion 7 f containing a discontinuous phase comprising an -aqueous colloidal dispers'ionof a copolymer of vinylidene' chloride and acrylonitrile, and a' con tinuous phase comprising a thermosetti'ng resin- -ous binder selected" from the group consisting of 7 alcoholated inelarninefiormaldehyde -'resinous condensates and alkyd-modifled melamine-formaldehyde resinous condensates in organic solvents which are substantially non-solvents for the said copolymer of vinylidene chloride and acrylonitrile, said emulsion containing a nonvolatil liquid plasticizer for said copolymer of vinylidene chloride and acrylonitrile, the ratio of plasticizer to said copolymer of vinylidene chloride and acrylonitrile being within the range of from approximately one to approximately two parts by weight of plasticizer to one part by weight of said copolymer of vinylidene chloride and acrylonitrile.

5. A coloring composition for textile materials comprising pigment dispersed in an emulsion containing a discontinuous phase comprising an aqueous colloidal dispersion of a thermoplastic resinous material selected from the group consisting of a homopolymer of vinyl chloride, a copolymer of vinyl chloride and vinyl acetate, and a copolymer of vinylidene chloride and acrylonitrile, and a continuous phase comprising a butylated melamine-formaldehyde resinous condensate in a solvent mixture comprising mineral spirits and butanol, said emulsion containing a non-volatile liquid plasticizer for the resinous material of the discontinuous phase, a ratio of plasticizer to the resinous materials of said discontinuous phase being within the range of from approximately 1 to approximately 2 parts by weight of plasticizer to 1 part by weight of said resinous material.

6. A coloring composition for textile materials comprising pigment dispersed in an emulsion containing a discontinuous phase comprising an aqueous colloidal dispersion of a copolymer of vinyl chloride and vinyl acetate, and a continuous ph'ase comprising a butylated melamine-formaldehyde resinous condensate in a solvent mixture comprising mineral spirits and butanol, said emulsion containing a non-volatile liquid plasticizer for said copolymer of vinyl chloride and vinyl acetate, the ratio of plasticizer to said copolymer of vinyl chloride and vinyl acetate being within the range of from approximately 1 to approximately 2 parts by weight of plasticizer to 1 part by weight of said copolymer of vinyl chloride and vinyl acetate.

EDWARD F. ARMATYS.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,361,454 Cassel Oct. 31, 1944 2,431,078 Powell et a1 Nov. 18, 1947 2,511,171 Mitchell June 13, 1950

Claims

1. A COLORING COMPOSITION FOR TEXTILE MATERIALS COMPRISING PIGMENT DISPERSED IN AN EMULSION CONTAINING A DISCONTINUOUS PHASE COMPRISING AN AQUEOUS COLLOIDAL DISPERSION OF A THERMOSPASTIC RESINOUS MATERIAL SELECTED FROM THE GROUP CONSISTING OF A HOMOPOLYMER OF VINYL ACETATE, COPOLYMER OF VINYL CHLORIDE AND VINYL ACETATE, AND A COPOLYMER OF VINYLIDENE CHLORIDE AND ACRYLONITRILE, AND A CONTINUOUS PHASE COMPRISING A THERMOSETTING RESINOUS BINDER SELECTED FROM THE GROUP CONSISTING OF ALCOHOLATED MELAMINE-FORMALDEHYDE RESINOUS CODENSATES AND ALKYD-MODIFIED MELAMINE-FORMALDEHYDE RESINOUS CONDENSATES IN ORGANIC SOLVENTS WHICH ARE SUBSTANTIALLY NON-SOLVENTS FOR THE RESINOUS MATERIAL OF THE AQUEOUS PHASE, SAID EMULSION CONTAINING A NONVOLATILE LIQUID PLASTICIZER FOR THE RESINOUS MATERIAL OF THE DISCONTINUOUS PHASE, THE RATIO OF PLASTICIZER TO THE RESINOUS MATERIAL OF SAID DISCONTINUOUS PHASE BEING WITHIN THE RANGE OF FROM APPROXIMATELY 1 TO APPROXIMATELY 2 PARTS BY WEIGHT OF PLASTICIZE TO 1 PART BY WEIGHT OF SAID RESINOUS MATERIAL.