US3838989A

US3838989A - Matches

Info

Publication number: US3838989A
Application number: US00398754A
Authority: US
Inventors: C Cohn
Original assignee: Individual
Current assignee: Individual
Priority date: 1972-05-05
Filing date: 1973-09-19
Publication date: 1974-10-01
Anticipated expiration: 1991-10-01

Abstract

Matches are provided which minimize the probability that a discarded lighted match will ignite flammable substances upon which it may be dropped. To this end, matches, as used, are partially surface coated with a fire retarding material such as a silicate so that only part of the match surface will sustain a flame and only when the flammable head of the match is held downwardly with respect to the main portion of the match stem, the flame going out when the match head is held upwardly or horizontally with respect to the major portion of the stem or flutters as it is dropped. The resistence of a match book to accidental burning may be improved if the match book cover is coated, over any printing thereon, with a silicate solution. An additional advantage is secured if the striking surface is also coated with an alkali silicate, this making it more difficult for a child to strike a match.

Description

United States Patent [1 Colin 1 51 Oct. 1, 1974 MATCHES [75] Inventor: Charles C. Cohn, Atlantic City, NJ.

[73] Assignees: Samuel L. Cohn; Charles C. Colin,

both of Philadelphia, Pa.

22 Filed: Sept. 19, 1973 21 App]. No.2 398,754

Related U.S. Application Data [63] Continuation-in-part of Ser. No. 250,649, May 5,

1972, abandoned.

Primary Examiner-C. Dees Attorney, Agent, or FirmSmith, l-larding, Earley & Follmer 7 ABSTRACT Matches are provided which minimize the probability that a discarded lighted match will ignite flammable substances upon which it may be dropped. To this end, matches, as used, are partially surface coated with a fire retarding material such. as a silicate so that only part of the match surface will sustain a flame and only when the flammable head of the match is held downwardly with respect to the main portion of the match stem, the flame going out when the match head is held upwardly or horizontally with respect to the major portion of the stem or flutters as it is dropped. The resistence of a match book to accidental burning may be improved if the match book cover is coated, over any printing thereon, with a silicate solution. An additional advantage is secured if the striking surface is also coated with an alkali silicate, this making it more difficult for a child to strike a match.

10 Claims, 6 Drawing Figures MATCHES CROSS-REFERENCE TO RELATED APPLICATION This application is in part a continuation of my application Ser'. No. 250,649, filed May 5, 1972 now abancloned.

BRIEF SUMMARY OF THE INVENTION Propagation of a flame in cellulosic materials such as paper, cloth, dried leaves, etc. involves essentially a process in which the heat of a flame produces what may be described as a dry distillation of the cellulosic material to produce flammable gases which upon ignition burn with a flame. In other words, the progress of burning is not a direct oxidation of solid material but solely through the procedure of gas generation and burning of the gas. If the gas generation is inhibited by deterring the transfer of heat, most substances will cease to burn. This is evident in the case of a candle, for example. As the candle burns, wax is melted and rises in capillary fashion in the wick which is sufficiently hot to produce gases which are flammable and which, by burning, maintain the gas production and melting of the wax to continue the burning. The structure of a flame in general involves interiorly non-burning gases which ignite only at the exterior portions of the flame where admixture with air produces a flammable gas mixture. Even substances such as charcoal involve this action to some extent even though the progress of burning may be in part due to sufficiently hot ash to produce flammable gas such as carbon monoxide by the partial oxidation of the heated charcoal. It is common experience, of course, that charcoal is relatively difficult to ignite, and disastrous fires generally result only when dropped burning matches come in contact with cellulosic materials which upon the application of heat quickly produce flammable gases which in turn ignite and propagate the burning action. Tobacco, when packed, as in a pipe, burns without an evident flame due to hot ashes, but is difficult to ignite (when not containing an oxidizing material); but, usually, destructive fires are propagated through flaming of loose cellulosic materials.

In accordance with the present invention, matches are produced in which the stems, whether of wood or cardboard, are partially coated with flame retarding material so that only limited portions of the stem surfaces are presented to the air and are capable of producing flammable gases only to a limited extent and under particular conditions to provide flame propagation.

Of course, in order that a match may be useful, for example to light a cigarette, a flame must exist for a short interval of time, comparable in extent with the burst of flame attending the burning of the match head composition. In accordance with the invention, following the initial burst of flame only a feeble flame continues to exist and only under a special condition of orientation of the match stem.

Specifically, the matches in accordance with the present invention have the following construction and operation:

Referring first to book matches, a sheet of cardboard of conventional thickness is coated, at least in the portion which will constitute match stems, with a flame retardant such as sodium silicate in concentrated solution which is dried after its application, the sheet being then either rolled up or directly further treated. Assuming a wide sheet to be initially produced and coated. it may then be slit into strips having widths corresponding to the length of the match stems plus the pasteboard strip with which they are originally integral. They may be then slit to provide the individual match stems held by the strip which holds the stems in the conventional form of assembly.

The head ends of the stems are then conventionally dipped into the flammable composition which may be of conventional composition, consisting for example, of a mixture of glue, potassium chlorate, sulfur, a filler which may in part be of an abrasive nature, and a dye, all in the form of an aqueous paste. The head material is then permitted to dry, and the assemblies may then be separated by transverse cuts and conventionally assembled and stapled to the match book cover of a conventional type carrying a dried strip of striking material such as is conventionally a mixture of red phosphorus, abrasive and glue.

It will be noted that the procedure just outlined differs from the conventional procedure in two aspects:

First, in accordance with the invention, it is desirable to omit the dipping into wax prior to the application of the conventional flammable head material.

Secondly, there is the application of the flame retardant coating prior to the slitting to form the match stems with the result that the match stem beyond the head contains the silicate coating on both the broad surfaces of the stem but does not coat the opposite narrow edges of the stems so that the cellulosic material of the stems is there exposed. The silicate coating is sufficiently concentrated that the stem is not saturated; i.e., it is a surface coating only, which does not appreciably penetrate the material of the stems.

While both flat sides of the match stems are so coated, quite satisfactory results are obtained if only one face of a match stem is coated so that the opposite flat face and the two narrow edges or faces remain uncoated.

The match thus produced when torn from the match book has the following characteristics:

When the match is struck, the flammable head composition will flare and burn for a short time, usually sufficient to light a cigarette. But what happens after this initial flare depends upon the orientation of the match. If it is held with the head end downward, the heat of the flame will cause a propagation of the flame along the narrow edges of the match stem which present outwardly the uncoated cellulosic cardboard. Because of the narrowness of these edges the flame will be feeble, but will suffice to light a cigarette even if penetration to the cigarette is delayed beyond the period of existence of the burst of flame of the head itself. Sufficient heat for this propagation is afforded because the edges are essentially above the flame.

However, if the match is held in a sloping position with the head end up, the propagation of the flame will terminate very quickly after the head ceases to flare because rising cold air will provide sufficient cooling below the flame to prevent such heating of the edges as would maintain the necessary production of flammable gases. The same situation is true if the match is held approximately horizontal. lf, while the edges are burning the match is dropped, the flame will almost immediately go out not only due to the essentially horizontal orientation of the dropped match but augmented by the fluttering action in the air which has much the same effect as would result from blowing upon the match. Thus, as it is dropped, it will no longer be in condition to ignite cellulosic matter with which it comes into contact.

Practically no hot ash condition will exist because the narrow edges are so thin as to readily cool and the broad faces of the match are covered with the silicate or similar coating producing aqueous vapor or inert gas having further cooling effect. Thus, there is effectively avoided any possibility that the material upon which the match is dropped can become ignited. Only under exceptional circumstances, which are minimal, could ignition occur, for example by reason of the match being dropped upon some highly inflammable material. In fact, due to the feeble flame and the rapidity of this extinction there is also a minimizing of the possibility of damage to the surface of painted or varnished furniture upon which the match may be dropped even when there is no reasonable possibility of production of a fire.

As is usual, the match stem, whether of cardboard or wood is impregnated with a material capable of preventing afterglow (such as ammonium phosphate) so that ignition of even highly inflammable substances is presented. This impregnation does not prevent flame propagation along the uncoated edges or sides of the match. But it is found that afterglow may be prevented (without impregnation of the stem) if the applied silicate solution contains upwards of about 13 percent SiO As a broad range of $0,, to achieve the tire resistance of the match, about 0.5 to about 30 percent may be employed.

While the foregoing description and the descriptions which follow hereafter are directed primarily to the preferred type of match in which opposite stem faces are coated with a flame retarding material, the descriptions of operation apply similarly if only one face of a match stem is so coated, with the opposite face and the other edges or faces uncoated. The coating on one face only insures the production of a feeble flame on the other surfaces with essentially the same results as those described.

BRIEF DESCRIPTION OF THE DRAWING FIGS. 1 and 2 are diagrammatic showings of a preferred procedure involved in the manufacture of book matches in accordance with the invention;

FIG. 3 is a perspective view showing a paper match book provided in accordance with the invention;

FIG. 4 is a perspective view showing an individual match as torn from a book prior to use;

FIG. 5 is a perspective view of a wooden match provided in accordance with the invention; and

FIG. 6 is a transverse section of the match of FIG. 5 taken on the surface indicated at 66 thereof.

DETAILED DESCRIPTION Referring first to the production of cardboard book matches, reference may be made to FIGS. 1 and 2 and the general procedure involved in manufacture in accordance with the invention. The majority of steps involved are completely conventional, and hence various steps of the production are not detailed, it being understood that they are conventionally carried out in any of the usual ways.

At 2 there is indicated a supply of the cardboard or heavy paper from which the match elements are formed. This may be initially a wide sheet from which cutting and slitting will ultimately produce the match elements to be assembled in a match book or pack. Conventionally, the sheet of board is treated with an antiglow material such as ammonium phosphate in aqueous solution. This solution impregnates the board to prevent glow of the match material when the flame is extinguished. In the present instance it is desirable to include in the impregnating solution a sizing material which may be of any of the numerous types used for treatment of paper to prevent, after drying, absorption of an applied coating material. For example, the size may consist of starch, or the like, used in suitable quantities along with the antiglow material. The sheet of material is dipped into a tank 4 so that the board is impregnated. Alternatively to this dipping, the size may be incorporated in the pulp during the board forming procedure. If thus incorporated, it will not materially affect the absorption of antiglow material applied by the dipping.

Following the impregnation with the antiglow material (as applied in the dipping process) the board is passed through a dryer 6 from which it is delivered in a dry condition.

Following the drying, there is applied to both faces of the sheet (or to only one face thereof) the flameretardant material. The nature of this material will be described hereafter, but being viscous it will be understood that it will form a coating rather than being substantially absorbed in the material, absorption being minimized by reason of the sizing which impregnates the board. The application of the flame-retardant material may be carried out in various ways, as, for example, by dipping, brushing or spraying, the last mode of application being that illustrated, the tire-retardant material being applied as a spray through nozzles 8. The sheet is then dried by passage through a dryer 10 which, like the dryer 6, may involve heating and a long passage time to furnish a dried sheet. Assuming that up to this time the sheet is quite wide, it may be slit in conventional fashion, as by rotary knives 11 into narrow strips corresponding in width to the length of a match stem plus the strip which unites the individual match stems.

The next step in the procedure involves slitting to form the individual match stems or splints, the slitting being carried out by a die 12 operating in conventional fashion to separate the match stems proper by providing cuts extending from an edge of the strip inwardly to the common carrying strip.

The procedure continues from the right of FIG. 1 into the left of FIG. 2. Each strip which may be initially horizontal is then twisted to present the head ends of the separated match stems downwardly for dipping into a container 14 of the head composition, the match stems being staggered in the usual fashion so that individual drops of the head composition are kept separate, suitable placement means being provided to maintain this condition. The strip then passes through a dryer 16, and thence passes to a conventional assembler and cutter in which multiple strips (two or three) are assembled together and with the match book cover by stapling with ultimate cutting and folding into the finished match books. The covers are conventionally coated with a strip of striking composition of conventional type.

It will be noted that the procedure differs from the conventional in two aspects:

Flame retardant composition is applied as described with the preliminary application of sizing, if desirable to prevent penetration of the flame retardant material.

The application of paraffin is omitted. In conventional match production paraffin is applied to augment the burning of the match stem after ignition. In accordance with the present invention, since it is desirable to prevent flame propagation paraffin is desirably omitted entirely, although it is possible that a very minor amount may be applied at the head end only of the stems to augment the initial flare, though in such small quantities that it would be entirely consumed in a very short interval of a second or two.

If the silicate is applied so as to extend into the region which is to carry the flammable head, the head material may not adhere to the silicate; but adhesion may be achieved by dipping the end region of the dried silicate into dilute NaOH, or by permitting this small area to remain uncoated, either by masking or by printing, wherein that area is not printed upon with the tire retardant material.

A completed match book provided in accordance with the invention is illustrated in FIG. 3, wherein the individual matches 18 are initially integral with strips 19 from which they may be torn. The folder or cover is indicated at 20, and to this the multiple match assemblies are stapled as at 22. The striking surface on the cover is indicated at 24.

An individual match as torn off to be used is indicated in perspective in FIG. 4. The coating of flame retardant material may occupy only part of the stem, leaving uncoated the base 26. The broad surface or surfaces of the match contain the flame retardant coating. Characteristic of the match is the fact that the narrow longitudinal edges of the match stem are uncoated exposing the board so that these edges are capable of propagating the flame even though impregnated with the antiglow material and sizing. This condition is achieved by virtue of the fact that the board material from which the matches are made is coated, without substantial impregnation by the dry flame retardant material before slitting so that this material does not coat the narrow edges 30. The flammable head material is indicated at 32.

The match illustrated in FIG. 4 has the characteristics involved in the advantages of this invention. When the match is struck, the head material will flare for one or two seconds and if the match is held either horizontally or with its head end upwardly it will immediately go out after the initial flare without afterglow. On the other hand, if it is held with the head end downwardly a feeble flame will persist sufficient to give, if desired, a more ample time for use of the match for igniting a cigarette or other flammable material which is intended to be ignited.

After the desired ignition is effected, if the match is moved to a horizontal position or to a position in which the head end extends upwardly, the flame will go out almost immediately. Thus, there is a negligible danger of ignition of any flammable material in an ash tray or if the match is dropped upon flammable material. In the latter case, fluttering of the match as it is dropped will cause immediate extinction of any residual flame.

The flame retardant coating has been described as applied in the form of a solution. But alternatively, there may be used a laminated paper board in which the intermediate layer may be a board of the same type as is conventionally used for the formation of book matches while the flame retardant coating may be provided by lamination to the faces of this board of thin paper laminations impregnated with flame retardant material so that the outer laminations will not support a flame. If such a laminate is used, the procedure can then be identical with that used in providing conventional book matches; i. e., the starting board may be the laminate, and after slitting to form. strips and the match stems the first step may be dipping to form the heads. Here again, the slitting will produce stems of which the broad surfaces are incapable of propagating a flame while the thin cut edges can maintain the desired feeble flame. It will be understood that the term coating herein includes the outer laminating layers as just described as well as coatings produced by the drying of flame retardant solutions. The laminate may also be a non-combustible material such as a metal foil, a noncombustible synthetic coating, asbestos, etc.

The foregoing has described the procedure of making book matches in accordance with the invention, but the invention is equally applicable to the manufacture of wood matches using the general procedure of forming a veneer which is chopped into splints. The veneer, as is customary, may be treated with an antiglow solution such as ammonium phosphate to impregnate the veneer and prevent afterglow. Following drying, the flame retardant material is applied to one or both of the veneer surfaces, by spraying, brushing, or other suitable procedures and dried. Alternatively, the veneer may have laminated to its surfaces thin paper sheets impregnated with flame retardant material so that these sheets will not sustain a flame. Thereafter it is chopped into the splints which are inserted into carriers for dipping to provide the head material or materials, these further operations being entirely conventional. If the wood is substantially absorbent, it may be desired to incorporate in the antiglow material a size as described in connection with the formation of book matches.

A match formed in accordance with this procedure is illustrated in FIG. 5. The splint. is coated at 34 with the flame retardant material provided by the coating of the opposite faces of the veneer. The chopping operation then produces the surfaces 36 which are uncoated and serve to propagate the feeble flame in accordance with the invention.

The matches thus produced may be of the safety type or of the strike anywhere type. The latter is illustrated: the igniting composition at 40 coats the outermost end of the usual bulbous inflammable material indicated at 38 which prevents rubbing of the striking material 40 when the matches are boxed in usual fashion. A double dipping is required to produce this type of head. If safety matches are produced, there is a single flammable composition which ignites only when the match is struck on the striking composition in the form of a strip coating a side of the box.

Reference has heretofore been made to the coating of either or both of the broad surfaces of book matches and to one or both of opposite faces of wooden match stems. While the utmost in providing only a feeble flame under described conditions is achieved when opposite faces are coated, completely acceptable results are secured when only one surface is coated in the case of book matches or when only one surface is coated in the case of a wooden match stem of approximately square cross section. When only one surface of a match is so coated with the flame retardant material, the feeble flame described may propagate along the other three surfaces or edges, and this is true even when conventionally large wood matches are involved having faces approximately /8 inch in width.

The fire retardant coating has essentially a physical action, i. e., of isolating the combustible cellulosic material, whether paper or wood, from the heat of the flame, and hence its chemical composition is of little significance. However, if a composition is used which, in its dry condition contains water, the emission of steam probably contributes to the lowering of flammability. A great variety of flame retardants may be used so long as they form coatings and are not themselves inflammable under conditions of burning of a match in the fashion provided by the present invention.

However, sodium or potassium silicate is a most acceptable and outstanding retardant which may be used since it forms a glass-like coating which even when very thin has the desired properties and because these silicates are quite inexpensive. As heretofore indicated, the retardant is applied in aqueous solution and may be applied to the entire length of the match stem, including the flammable head portion or on the portion of the stern adjacent to but not including the flammable head. Even if it extends throughout the entire stem length, the flammable composition will flare as usual and will then ignite under the conditions discussed the uncoated edges of the stem in the case of a paper match, or the uncoated surfaces of a wood match. When a silicate is used, it is found that the thickness of the dried silicate coating is desirably about 0.001 inch or less, even down to 0.0001 inch. Thicker coatings are not detrimental, but represent waste of material. A 0.001 inch thickness may be achieved if the silicate solution is concentrated; while thinner coatings result if the silicate solution is dilute.

The silicate solution which is applied may vary greatly in composition. The usual silicate solutions as sold will generally require dilution since initially they are so viscous and concentrated that material is wasted and drying is impracticably slow. Dilution is accordingly desirably made to such extent that, if unsized paper or wood is treated, deep penetration of the silicate solution is avoided. Too much penetration is undesirably because it may unduly lessen the ability of the uncoated edges to maintain the desired feeble flames; in other words, the penetration should not be such as to render the uncoated surfaces of the match noninflammable. For example, it has been found that dilution of alkali silicates may be effected to the extent that the percentage of SiO by weight, is as low as 0.5 percent even when the cellulosic material to which it is applied is unsized. If sizing is used, even less concentration of SiO may be used. Higher concentrations are merely wasteful and require more drying time. Preferred concentrations of SiO range from about 13 to 16 percent by weight of the liquid silicate, the dried silicate being on the order of about 1.5 to about milligrams per square centimeter of coated surface. Commercial alkali silicates are supplied in wide ranges of the ratio of alkali oxide to silica and have varying degrees of alkalinity; but since the action is not essentially a chemical one, this ratio is quite immaterial. As provided commercially, silicates may contain SiO in amounts such as 30 percent or more. Such concentrated solutions are desirably diluted as stated above. The content of SiO may be used as the criterion to determine the suitable concentration of solids in the dilute solutions used for the silicate application.

instead of silicates, a wide variety of fireproofing or retardant materials may be used, and, in general. these may be chosen from the well-known substances which are commonly used for fireproofing of fabrics. Among these, for example, are ammonium salts of acids which are inert from the standpoint of being either flammable or of oxidizing nature. Diammonium phosphate is very commonly used for fireprooflng and is applicable for use in accordance with the present invention, as are ammonium chloride, ammonium sulfate, and even ammonium salts of organic acids which, despite their organic content are non-inflammable. Boric acid and alkali borates are usable, as are also the phosphates of sodium or potassium. Besides these, organic or semiorganic materials of non-inflammable type may be used such as chlorinated resins or oils, which may be applied in the form of emulsions. Among other materials there may be referred to alums and aluminum or iron sulfates. Of course, it is desirable that the fire retardants should be inexpensive and this will economically rule out some well known fire retardants such as sodium tungstate which is used when expense is a minor consideration. The alkali metal silicates which dry to a glassy coating have the special advantage that they will strength a book match so that breaking during striking is avoided even if the match is held by the fingers at a considerable distance from the igniting end.

Many of the foregoing salts are soluble in water and their solutions are of low viscosity and hence will penetrate porous cellulosic materials to such extent that they might render the entire match non-inflammable. Hence, either sizing of the match material is desirable or their solutions may be made viscous and relatively non-impregnating by incorporating into them soluble materials such as gums, gelatin, or the like. The compositions used are such as to produce primarily surface coatings without such impregnation as will defeat the desired flammability of the edges or uncoated surfaces of the stems. Of course, to provide antiglow properties, the match stems may initially be soaked with low concentration solutions of any of these materials in the fashions common in the art, producing flammable.

stems but such that glow after extinction of a match is prevented. Instead of initially incorporating an antiglow material, the flame retardant coating material may be such that a minor absorption takes place, sufficient to prevent afterglow but insufficient to extinguish the desired feeble flames produced by burning of the uncoated edges or surfaces.

The sizings herein referred to, if used, may be of any of the many types used for paper sizing, for example casein, starches, resins, shellac, dextrin, gelatin or albumin, and even quite dilute solutions of alkali silicates, applied in fashions suitable for the individual sizing materials.

Of course, mixtures of different flame retardant materials as described above may be used; and mixtures of sizing may also be used.

In summary, it is desirable to provide matches having properties as follows:

The flammable heads should have the usual flaring times of conventional matches, i. e., one to two seconds, and these flammable heads may be completely conventional.

Following this, it is quite satisfactory to have substantial burning continue for one or two seconds thereafter, even if thematches are held with the head ends upwards. But following this, the matches should continue to burn only if held with their head ends downwardly and then only with the described feeble flames running along their uncoated edges or surfaces as heretofore described. Desirably, wax should be omitted entirely, although minor amounts of wax may be used confined to the head portions only and such as not to produce active burning beyond the few seconds following strik- When sufficiently dilute flame retardant material is applied as a coating, there may be some feeble propagation of flame along the coated surfaces of the match despite the thin coating; but this is of the same nature as the feeble flame propagated along the uncoated edges or surfaces and the match will be extinguished promptly if the head end is held upwardly or the match is held horizontally. The desired feeble flame is nevertheless propagated primarily along the uncoated edges, and any flaming of the coated surfaces is secondary and unimportant.

The result of the foregoing described conditions of construction is that the match will be extinguished almost immediately if after the initial flare takes place it is oriented so that the stem is horizontal or with the head end upward, the flame becoming extinguished particularly if the match is dropped.

Greatly increased safety may be secured if a match book cover involving the matches described above is coated with a solution of an alkali metal silicate having a concentration of SiO upwards of about 13 percent, though silicate solutions of less concentration may be used, for example of 8 percent to 10 percent SiO if the cover is absorbent of the solution. This coating may be applied to the board material after printing since printing after coating is difficult. By so coating the cover material the cover will burn, even if all of the match heads become ignited, only for a short period so as to lessen the possibility of igniting other flammable materials on which it may be dropped. The silicate coating has an additional advantage of rendering the match book less susceptible to deterioration by moisture.

Especially desirable is the application of the silicate coating over the usual striking surface (the so-called friction) which is particularly flammable. If the silicate solution is applied in a concentration of the order of 13 percent SiO followed by wiping, striking is not completely prevented but becomes more difficult so that children are generally not able to strike a match, though an adult may do so. The necessity for wiping the silicate solution off the friction may be avoided if a weaker alkali metal silicate is used containing, for example, 8 to 10 percent SiO in which case, merely by drying, the flammability is satisfactorily reduced without making striking very difficult. With these lower concentrations of SiO the silicate soaks well into the entire cover including the friction. The cover and the friction may, of course, be separately coated with silicate solutions, though generally it is desirable to coat both simultaneously.

Striking is more difficult than usual after silicate coating, but the silicate coating of the match stems make them more rigid and less susceptible to breaking. A further advantage of this coating of the striking surface is that sparking is reduced, the surface having somewhat reduced frictional characteristics. The silicate coating on the striking surface also minimizes its accumulation of chlorate which accumulation ordinarily occurs upon multiple striking of matches on the striking surface. Accumulation of chlorate from the match heads is undesirable since ordinarily it substantially increases the flammability of the striking surface.

I claim:

1. A match having a stem of combustible cellulosic material and a flammable head, said stem being of approximately rectangular cross-section, said stem having at least one face coated with a flame retardant material at least in extended portions thereof inwardly of, and closely adjacent to, said head, with other faces uncoated to expose lengthwise regions of the combustible material of the stem which alone are capable of burning with a feeble flame only when the match is held in air with its head end extending downwardly after initial flare.

2. A match according to claim 1 in which opposite faces of a pair are so coated.

3. A match according to claim 1 in which the stem is flat to present relatively broader opposite faces and relatively narrower opposite faces, and in which the flame retardant coating is on at least one of said broader faces and in which the narrower faces are uncoated.

4. A match according to claim 1 in which the material of the stem is impregnated with a material to prevent afterglow.

5. A match according to claim 1 in which the flame retardant coating comprises a dried silicate of an alkali metal.

6. A match according to claim 2 in which the flame retardant coating comprises a dried silicate of an alkali metal.

7. A match according to claim 3 in which the flame retardant coating comprises a dried silicate of an alkali metal.

8. A match according to claim 4 in which the flame retardant coating comprises a dried silicate of an alkali metal.

9. A book match assembly comprising a board cover and a group of removable matches secured therein, said cover provided with a coating having an alkali metal silicate as a primary constituent, and each match having a stem of combustible celluilosic material and a flammable head, said stem being of approximately rectangular cross-section, said stern having at least one face coated with a flame retardant material at least in ex tended portions thereof inwardly of, and closely adjacent to, said head, with other faces uncoated to expose lengthwise regions of the combustible material of the stem which alone are capable of burning with a feeble flame only when the match is held. in air with its head end extending downwardly after initial flare.

10. A book match assembly according to claim 9 in which the cover contains a striking surface also provided with a coating having an alkali metal silicate as a primary constituent.

Claims

1. AND A FLAMMABLE HEAD, SAID STEM BEING OF APPROXIMATELY RECTANGULAR CROSS-SECTION, SAID STEM HAVING AT LEAST ONE FACE COATED WITH A FLAME RETARDANT MATERIAL AT LEAST EXTENDED PORTIONS THEREOF INWARDLY OF, AND CLOSELY ADJACENT TO, SAID HEAD, WITH OTHER FACES UNCOATED TO EXPOSE LENGTHWISE REGIONS

9. A book match assembly comprising a board cover and a group of removable matches secured therein, said cover provided with a coating having an alkali metal silicate as a primary constituent, and each match having a stem of combustible cellulosic material and a flammable head, said stem being of approximately rectangular cross-section, said stem having at least one face coated with a flame retardant material at least in extended portions thereof inwardly of, and closely adjacent to, said head, with other faces uncoated to expose lengthwise regions of the combustible material of the stem which alone are capable of burning with a feeble flame only when the match is held in air with its head end extending downwardly after initial flare.