Патент USA US2411116код для вставки
2,411,116 Patented Nov. 12, .1946 ' UNITED sTAT'E S PATENT OFFICE 2,411,116 , SELF-HEALING CONTAINER FORMING ' MATERIAL ' - Manuel Sanz, Los ' Angeles, Calif., assignor, by mesne assignments, to Consolidated Vultee Air craft Corporation, a corporation of Delaware Application March 21, 1942, Serial No. 435,689 4 Claims. (01. 1544-435) 1 2 The present invention relates generally to self healing material. More particularly the inven tion relates to that type of material which is more particularly de?ned by claims at the com I designed primarily for use in the fabrication of a vfuel or lubricant container, automatically seals 5 . ‘ itself immediately after being punctured or torn clusion hereof. In the drawing which accompanies and forms a part of this speci?cation or disclosure and in which like numerals of reference denote corre sponding partsthroughout the several views: Figure l is a perspective of a piece of self by“ a projectile or like object, and comprises a healing container forming material embodying self-healing intermediate layer of masticated rub-' her having pronounced cohesiveness, an outer the invention; and Figure 2 is an enlarged section of the material. layer of tough elastic material, such, for exam 10 The material which is illustrated in the draw ple, as fully cured or vulcanized rubber, and an inner‘ layer of synthetic rubber or like mate ing constitutes the preferred form or embodi rial of the type that is insoluble in, and unaf ment‘of the invention. It is essentially of‘ the self fected by, hydrocarbons. 1 healing variety and has special capability of use The primary object of the invention is to pro 15 in the fabrication of a gasoline or lubricant con vide a self healing container forming material of this type which has certain advantages over, tainer for an airplane or other vehicle. Gener~ ally speaking, the material is a laminated or and is more e?icient than, previously designed materials, especially that which is disclosed in, and forms the subject matter of, application for 20 United States Letters Patent ?led by Scott, Rethorst on July 29, 1940, Serial No. 348,098 (now Patent No.'2,406,903, dated September 3, lamellated structure and is of the so-called self _ healing variety by reason of the fact that imme diately after being punctured or torn it seals automatically. When the material is used to form an airplane fuel container any bullet or pro jectile passing ‘through it results in no loss of fuel due to the special self healing tendencies. 1946). ' Another object of the invention is to provide 25 or properties of the material. As its components the material comprises an intermediate layer 3, a self healing material‘ of the type and character an outer layer 4 and an inner layer 5.‘ These under consideration’in which the self healing three layers are bonded together as hereinafter intermediate layer is formed of partially, cured or vulcanized masticated rubber and has an ad described, with the result that the material is mixture of a small amount of synthetic resin 30 essentially of unitary character. which is insoluble in hydrocarbons. The intermediate layer 3 is the self healing layer and possesses its self healing attributes due A further object of the invention is to provide to its chemical and physical properties. It is a composite or laminated self healing material formed for the most part of partially cured mas— of the aforementioned type in which the inner layer of vulcanized synthetic rubber is vulcanized ticated rubber and is characterized by the ‘fact that it has an extreme or ‘pronounced degree in situ on the inner face of the self healing of cohesiveness. This marked degree of cohe intermediate layer and has an admixture of a siveness results in the layer having the desired small amount of a synthetic resin which serves as an e?icient plasticizer for the synthetic rub self healing action. The layer 3 is formed by. ber- while at the same time it does not affect 40 mixing together the following components or ingredients 'in substantially the proportions set in any way the resistance of the synthetic rubber to gasoline, oil or other hydrocarbons. forth and then subjecting them to a vulcaniz ing temperature in order to obtain a partial cure: A still further object of the invention is to provide a self healing container forming material which is generally an improvement inthe art, 45 effectively and e?iciently ful?lls its intendedpur pose and may be manufactured at a compara tively. low cost. ‘ ‘ . ‘ , . ‘ Parts by weight Masticated rubber ______________________ __ 100 Zinc _ 2 Agent for producing partial cure________ __'_ oxide ‘A ‘ ' \ ‘ Synthetic resin advantages and characteristics of the present self 50 Pale‘crepe rubber'is preferably’ used as the rub ber component- Such rubber is preferably mas healing container forming material. will be ap tic'ate'd to the desired degree of plasticity'by mill parent from a consideration of the following ing it together with the other ingredients or detailed description. components. The zinc oxide serves as an anti The invention consists in the several novel features whichare hereinafter set forth and are 55 oxidant and also as an activator for the agent Other objects of the invention and the various \ . ' 2,411,116 , a ‘ - 3 by a ‘Shore durometer and in addition tensile for effecting partial cure. For such agent tetra methylthiuram disulphide or tetramethylthiuram tetrasulphide is used.- Tetramethylthiuram di strength of approximately 3500 pounds. per square inch and an elongation of 550 per cent at break. Vulcanized rubber of this character . sulphide is known commercially as “Tuads” and is relatively hard and has such elasticity that when compressed by the passage of a projectile therethrough it returns to its normal position amount of the agent and the fact that the agent and thereby closes the hole or puncture. When . (tetramethylthiuram disulphide or tetramethyl the material is punctured the punctured portion thiuram tetrasulphide) possesses but a small quantity of sulphur the rubber component of the 10 of the outer layer 4 springs together or contracts and hence draws together the punctured por ~ composition constituting the layer 3 is only par tion of the intermediate layer 3. As soon as the tially cured or vulcanized when it is subjected punctured portion of the intermediate layer is to heat for vulcanizing purposes. Glycol-seba drawn together by the action of the outer layer cate is preferably used as the synthetic resin ‘ component. This particular material is insoluble 15 such portion seals, as hereinbefore pointed out, due to cohesiveness and swelling. The outer in, and unaffected by, hydrocarbons and has sev layer 4 is formed by sheeting out into layer form eral functions or purposes. In the ?rst place a mass of rubber having sulphur or any other it operates as a plasticizer for the pale crepe vulcanizing agent therein together with a suit rubber during mastication of the latter by mill ing. In addition it tends to make-the layer‘3 20 able accelerator for the vulcanizing agent and a small quantity of zinc oxide for activating the‘ plastic. Another function of the synthetic resin accelerator. After sheeting of the mass to form is to increase the strength of the partially cured the layer 4 said layer is brought into contact with rubber component of the layer 3. The synthetic the layer 3‘and the two layers are subjected to resin, although insoluble in, and unaffected by, hydrocarbon, such as gasoline, does not change 25 heat. During the heating step the composition. or rubber mass constituting the outer layer 4 to any great degree the normal properties _of the tetramethylthiuram tetrasulphide is known com merci'ally as ‘v‘Tetrone? Because of the small‘ masticated pale crepe rubber. It does, as previ ously pointed out, give strength to the layer as a whole. When the layer 3 is punctured by a bullet or .other projectile the torn edges are 30 drawn together in response tovthe herein de scribed action of the outer layer 4. As soon as is fully vulcanized and the composition consti tuting the intermediate layer 3 is partially vul canized. As heretofore pointed out, atempera ture of approximately 287° F. is employed for vulcanizing purposes and. the material is sub jected to such temperature for forty minutes. During the vulcanizing operation'there is a slight such edges are drawn into contact with one an migration of “the sulphur or other vulcanizing other a sealing action is effected due to‘ the marked or pronounced degree of cohesiveness of 35 agent in the outer layer into the outer face of the intermediate layer 3. Such migration results the layer 3. Because a slight amount of gaso in the outer layer becoming permanently bonded line flows into the cut or tear a swelling action to the intermediate layer. takes-place and this assists in effecting auto matic sealing. This swelling is due to the chemi The inner layer 5 is coextensive with, and per cal action which takes place when ‘the partially 40 manently bonded to, the irm'er face of theinter cured rubber is contacted by the gasoline. By mediate layer 4. It is formed of vulcaniz‘ed syn having a small amount of synthetic resin, such thetic rubber and an admixture of synthetic resin. as glycol-sebacate, in the layer 3 the torn edges “Neoprene” [chloroprene] or “'I'hiokol” [an olefin of the punctured portion of the layer have suf?- . polysul?de reactionproductl may be used as the cient resistance to the gasoline so that the seal 45 synthetic rubber component of the inner layer 5. ‘ obtained by cohesion and swelling is not weak ened or dissolved by the gasoline. Glycol-seba cate is a polymerized ester of the alkyd type and is known commercially as “Dyal 1929.” In lieu of glycol-sebacate, glycerol phthalate may be, used. In producing the layer 3 the various com ponents or ingredients are introduced into a mill and are then milled until the composition has a ‘ plasticity of 250 as measured by a Williams par Glycol-sebacate is preferably used as the syn thetic resin. In practice it has been found that . such a resin when used in an amount of from , so 1% to 10% by weight of the synthetic rubber pro duces the desired results. The synthetic resin, that is, the glycol-sebacate, serves as a plasticizer for the synthetic rubber and makes it possible readily and evenly to sheet the composition con After milling to the stituting the inner layer in connection with formation of such layer. .In forming the inner proper extent the composition is calendered into layer form. It is then subjected to a tempera ture of approximately 287° F. for forty minutes. layer the synthetic resin is milled or otherwise mixed with the synthetic rubber and the resultant allel plate plastometer. mass is then sheeted onto the inner face of the During the high temperature period to which intermediate layer 3 prior to the vulcanizing step. the composition is subjected a partial cure or 60 During‘ the vulcanizing stepvulcanization of the vulcanization of the pale crepe rubber compo inner layer occurs and the latter becomes per nent’isl obtained. _The ?nal product constitut manently bonded to the inner face of the inter mediate layer 3. The inner layer, by reason of the fact that it is formed of synthetic rubber, , however, plastic and possesses an extremely high 65 such as “neoprene” or “Thiokol,” and synthetic ing the layer 3 is pronouncedly elastic but has ‘substantially no adhesiveness or tackiness. It is, degree of cohesiveness. The outer layer 4 serves as a reenforcing or resin, such as glycol-sebacate, is insoluble in, and unaffected by,‘ gasoline or other hydrocarbons strengthening medium for the self healing inter and hence ,when the material is used to form a mediate layer 3 and is coextensive with the lat fuel container the fuel is prevented from con ter. It is permanently bonded to the outer face 70 tacting and a?ecting the intermediate layer 3 of the layer 3 and is formed of fully cured or vul canized rubber. In practice it has been found that desirable results are obtained when the of partially cured masticated rubber. The inner _ layer is tough, elastic and flexible and when punc tured the punctured portion springs back and draws with’ it the adjacent punctured portion of outer layeris formed of vulcanized rubber hav ing a hardness of approximately 65 as measured 75 the intermediate layer 3. The punctured por 2,411,110 6 tion of the inner layer permits a small portion of gasoline to ?ow into the cut or punctured por strength of, the masticated partially cured rub ber without inhibiting swelling of said rubber tion of the intermediate layer and this results in when the latter is contacted by hydrocarbons, an swelling of the punctured portion of the inter outer layer of tough highly elastic vulcanized rub-. mediate layer, as heretofore pointed out. In Cl ber vulcanized in situ on the outer face of, and practice it has been found that desirable results serving to reenforce, the self healing layer and are obtained when the synthetic rubber consti adapted in connection with puncture of the mate tuting the-inner layer 5 has a hardness of ap rial .to have its punctured portion contract and proximately 35 as measured by a Shore durom draw together the punctured portion of the self eter. Because glycol-sebacate, the material that 10 healing layer, and an inner layer of vulcanized is used as the plasticizing agent for the syn- , synthetic rubber vulcanized in situ on the inner thetic rubber component of the inner layer, is insoluble in, and unaffected by, hydrocarbons, the hydrocarbon resisting properties ofthe synthetic face of the intermediate layer and selected from the group consisting of Chloroprene and an olefin polysul?de reaction product. rubber are not affected. By having glycol-seba 15 cate or a similar synthetic resin in the inner layer . as well as the intermediate layer an eiiicient bond between the two layers is obtained. ‘ ' 3. A container forming material comprising a self healing intermediate layer formed of masti cated partially cured rubber having an extremely high degree of cohesiveness but substantially no tackiness or adhesive tendency, and a uniformly The thickness‘ of each layer is immaterial, although it has been found in practice that good 20 dispersed admixture of a synthetic resin selected resultsare obtained when the inner layer 5 is from the group composed of glycol-sebacate and a‘: of an inch in thickness; the intermediate layer glycerol phthalate and in such amount that it 3 is 1A; of an inch in thickness: and the outer serves as a plasticizer for, and to increase the layer 4 is 1”; of an inch in thickness. strength of, the masticated partially cured rubber The herein described material effectively and 25 without inhibiting swelling of said rubber when efficiently ful?lls its intended purpose and has the latter is contacted by hydrocarbons, an outer marked or pronounced self healing properties. layer of tough highly elastic vulcanized rubber Whereas the material has been described as bonded to the outer face of, and serving to reen being primarily for use in the manufacture of force, the self healing layer and adapted in con fuel containers it is to be understood that it is 30 nection with puncture of the material to have capable of being used for'othe'r purposes. It is its punctured portion contract and draw together also to be understood that the invention is not the punctured portion of the self healing layer, to be restricted to the details set forth since these and an inner layer bonded to the inner face of may be modi?ed within the ‘scope of the appended the intermediate layer and formed of vulcanized claims without departing from the spirit and synthetic rubber selected from the group consist scope of the invention. ing- of Chloroprene and an ole?n polysul?de re Having thus described the invention what I action product and a uniformly dispersed admix claim as new and desire \to secure by Letters Pat ture of glycol-sebacate in su?icient amount to ent is: plasticize the vulcanized synthetic rubber and '1. A container forming material comprising a 40 also promote adhesion of the latter to said inner self healing intermediate layer formed of masti face of the intermediate layer. ‘ cated partially cured rubber having an extremely 4. A container forming material comprising a high degree of cohesiveness but substantially no self healing intermediate layer formed of masti tackiness or adhesive tendency, and a uniformly cated partially cured rubber having an extremely dispersed admixture of a synthetic resin selected 45 high degree of cohesiveness but substantially no from the group composed of glycol-sebacate and tackiness or adhesive tendency, and a uniformly glycerol phthalate and in such amount that it dispersed admixture of a synthetic resin selected, serves as a plasticizer for, and to increase the from the group composed of glycol-sebacate and strength of, the masticated partially cured rubber glycerol phthalate and in such amount that it without inhibiting swelling of said rubber when serves as a plasticizer for, and to increase the the latter is contacted by hydrocarbons, an outer strength of, the masticated partially cured rubber layer of tough highly elastic vulcanized rubber without inhibiting swelling of said rubber when bonded to the outer face of, and serving to re the latter is contacted by hydrocarbons, an outer enforce, the self healing layer and adapted in layer of tough highly elastic vulcanized rubber connection with puncture of the material to have 66 vulcanized in situ on the outer face of‘, and serv its punctured portion contract and draw together ing to reenforce, the self healing layer and the punctured portion of the self healing layer, adapted in connection with puncture of the ma . and an inner layer bonded to the inner face of the terial to ‘have its punctured portion contract and draw together the punctured portion of the self healing layer, and an inner layer formed of vul canized synthetic rubber vulcanized in situ on the inner face of the self healing layer and selected-fromv the group composed of Chloroprene intermediate layer and formed of vulcanized syn thetic rubber that is insoluble in, and unaffected by. hydrocarbons. , ' 2. A container forming material comprising a self healing intermediate layer formed of masti cated partially cured rubber having an extremely ' - and an ole?n polysul?de reaction product and a high degree of cohesiveness but substantially no 66 uniformly dispersed admixture of glycol-sebacate tackiness or adhesive tendency, and a uniformly 'insu?icient amount to serve as a. plasticizer for _ dispersed admixture of a synthetic resin selected ’ the vulcanized synthetic rubber and also to pro from the group composed of glycol-sebacate and glycerol phthalate and in such amount-that it ' mote adhesion of the latter to said inner face of ' the intermediate layer. serves as a plasticizer for. and to increasefthe 7Q ‘ MANUEL SANZ.