5. The copolycondensed vinylphosphonate of Claim 1A copolycondensed vinylphosphonate, according to Claim 1, resulting from the reaction between bis(2-chloroethyl) vinylphosphonate and dimethyl methylphosphonate.The copolycondensed vinylphosphonate of Claim 6, wherein the ratio, in said reaction, of dimethyl methylphosphonate to bis(2-chloroethyl) vinylphosphonate is in the range from about 1:10 to 10:1.The copolycondensed vinylphosphonate of Claim 7, wherein said ratio is in the range of 2:5 to 3:2.A process for flame retarding textiles, said process comprising applying to a textile an effective concentration of at least one copolycondensed vinylphosphonate and thereafter curing said copolycondensed vinylphosphonate so as to form an insoluble, fire retardant resin in and/or on the fibers of said textile; at least one of said copolycondensed vinylphosphonates comprising the product resulting from the reaction between a (2-haloalkyl) vinylphosphonate and at least one pentavalent phosphorus ester of the structure R0P(=0)XY where R is selected from the class consisting of Ci-C20 alkyl, Ci-C2o alkenyl and C1-C20 haloalkyl groups and X and Y are groups ass consistin of R0-, Ci-C2 alkyl, amino, aryl substituted amino, . C2-C∑0 alkylene bonded to the same or to another ROP(=0) moiety and C2-C20 alkyleneoxy and C2-C20 alkylenedioxy bonded to the same or to another ROP(=0) moiety.The process of Claim S, wherein said copolycon¬ densed vinylphosphonate is applied to said textile in a concen¬ tration which is sufficient to provide the thus treated textile with from about 5 to 50$ of the resulting resin as based on the dry weight of said textile.The process of Claim S, wherein the curing of said copolycondensed vinylphosphonate is effected in the presence of an effective concentration of a free radical initiating cat¬ alyst.The process .of Claim 9* wherein the curing of said copolycondensed vinylphosphoriate is effected by exposure to actinic radiation.The process of Claim 9, wherein the curing of said copolycondensed vinylphosphonate is effected by exposure to electron beam radiation. ethylenically unsatu 14. The process of Claim 9* wherein at least one^1 (a^'-'herein defined1) optional comonomer /is applied to said textile together with 40350/2 during the curing reaction.The process of Claim 14, wherein said optional comonomer is selected from the group consisting of acrylamide and N-methylolacrylamide .The process of Claim 9, wherein said copolycondensed vinylphosphonate comprises the product resulting from the reaction between tris(2-chloroethyl) phosphate and bis(2-chloroethyl) vinylphosphonate.The process of Claim 9, wherein said copolycondensed vinylphosphonate comprises the product resulting from the reaction between trimethyl phosphate and bis (2-chloroethyl) vinyl- phosphonate.The process of Claim 9 wherein said (2-halo- alkyl) vinylphosphonate is bis (2-chloroethyl) vinylphosphonate.The process of Claim 9* wherein said pentavalent phosphorus ester is dimethyl meth lphosphonate .The process of Claim 9, wherein R is selected 3 IX 72 fr0m he c ass consisting of methyl, ethyl, 2-chloroethyl and 2-chloropropyl groups.A process according to Claim 9 comprising L3 IX 72 the additional ste of neutralizing the. said polycondensedThe process of Claim 9> wherein said copolycondensed vinylphosphonate comprises the reaction product of dimethyl methylphosphonate and bis(2-chloroethyl) vinylphosphonate.The process of Claim 22, wherein the ratio, in said reaction, of dimethyl methylphosphonate to bis(2-chloroethyl ) vinylphosphonate is in the range of from 1:10 to 10:1.The process of Claim 2J>, wherein said ratio is in the range of 2:3 to 3:2.A process for flame retarding textiles, said process comprising applying to a textile an effective concentration of at least one copolycondensed vinylphosphonate and thereafter curing said copolycondensed vinylphosphonate so as to form an insoluble, fire retardant resin in and/or on the fibers of said textile; at least one said copolycondensed vinylphosphonates comprising the product resulting from the reaction between bis-(2-chloroethyl) vinylphosphonate and dimethyl methylphosphonate.A flame retardant textile comprising a textile whose fibers have present thereon and/or therein a cured, fire retardant resin of at least one copolycondensed vinylphosphonate comprising the product resulting from the reaction between a (2-haloethyl) vinylphosphonate and at least one pentavalent phosphorus ester of the structure R0P(=0)XY where R is selected from - - alkyl groups and X and Y are groups selected from the class consisting of R0-, Cx-Cso alkyl, Ci-C20 alkenyl, aryl, aryloxy, amino Cx-C2o alkyl substituted amino, aryl substituted amino, C2-C20 alkylene bonded to the same or to another ROP( =0 ) moiety and C2-C2o alkyleneoxy and C2-C2o alkylenedioxy bonded to the same or to another ROP(=0 ) moiety. 27 . The textile of Claim 26, wherein said resin comprises a copolymer of said copolycondensed vinylphosphonate and at least one optional comonomer. 28 . The textile of Claim 27 , wherein said optional comonomer is selected from the group consisting of acrylamide and N-me hylolacrylamide .The textile of Claim 26, wherein said ( 2-halo- alkyl) vinylphosphonate is bis( 2-chloroethyl) vinylphosphonate.The textile of Claim 26, wherein said pentavalent phosphorus ester is dimethyl methylphosphonate . 31 . The textile of Claim 26, wherein R is selected from the class consisting of methyl, ethyl, 2-chloroethyl and 2-chloropropyl groups.The textile of Claim 26, wherein said copolycondensed vinylphosphonate has-been substantially neutralized. c-¾'ioThe textile of Claim 2β, wherein said copolycondensed vinylphosphonate comprises the reaction product of dimethyl methylphosphonate and bis(2-chloroethyl ) vinylphosphonate . 3 . The textile of Claim 3, wherein the ratio, in said reaction, of dimethyl methylphosphonate to bis (2-chloroethyl ) vinylphosphonate is in the range of from about 1:10 to 10:1.The textile of Claim , wherein said ratio is in the range of from about 2:5 to 5:2.A flame retardant textile comprising a textile whose fibers have present thereon and/or therein a cured, fire retardant resin of at least one copolycondensed vinylphosphonate comprising the product resulting from the reaction between bis- (2-chloroethyl) vinylphosphonate and dimethyl methylphosphonate.A flame retardant polymeric resin OiupaaifcioiT containing moieties of at least one copolycondensed vinylphosphonate comprising the product resulting from the reaction between a (2-haloethyl) vinylphosphonate and at least one pentavalent phosphorus ester of the structure R0P(-0)XY where R is selected from the class consisting of Ci-Cso alkyl, Ci-Czo alkenyl, C!-Cso haloalkyl groups and X and Y are groups selected from the class consisting of R0-, Ci-C20 alkyl, amino, aryl substituted amino, C2-C20 alkylene bonded to the same or to another ROP(=0) moiety and C2-C2o alkyleneoxy and C2-C20 alkylenedioxy bonded to the same or to another ROP(=0) moiety.The resin aoiupuuiLluti of Claim 37, wherein moieties of an epoxy resin are also present. 39· The resin gompoaition of Claim 37, wherein moieties of a poly(ethylene terephthalate) are also present.The resin compooitiioti-of Claim 37, wherein said copolycondensed vinylphosphonate comprises the reaction product of bis(2-chloroethyl) vinylphosphonate and dimethyl methylphos-phonate .The resin tjmijJ-W>A halogenated addition product of a copolycondensed vinylphosphonate, said copolycondensed vinylphosphonate comprising the product resulting from the reaction between a (2-haloethyl) vinylphosphonate and at least one penta-valent phosphorus ester of the structure R0P(=0)XY where R is selected from the class consisting of Ci-C2o alkyl, ΰχ-ΰ20 alkenyl, C1-C20 haloalkyl groups and X and Y are groups selected from the class consisting of R0-, Ci-C20 alkyl, Ci-C20 alkenyl, aryl, aryloxy, amino, C1-C20 alkyl substituted amino, aryl substituted amino, aryl substituted amino, C2-C20 alkylene bonded C- 5'I0The addition produc of Claim 42, wherein said addition product is a brominated addition product.The addition product of Claim 42, wherein said addition product, is a chlorinated addition product.The copolycondensed vinylphosphonate of Claim 5, which has been substantially neutralized by being reacted wi h a neutralizing amount of a reagent selected from the group con- 13. IX.72 sisting of alkanols, trialkylorthoformates and epoxide reagents PhThe copolycondensed vinylphosmate of Claim 5, wherein said epoxide reagent is selected from the group consist¬IX.72 ing of ethylene oxide, propylene oxide, epichlorohydrin and the diglycidyl ether of isopropylidenediphenol.The process of Claim 21, wherein said copolycondensed vinylphosphonate has been substantially neutralized by being reacted with a neutralizing amount of a reagent selected from the group consisting of alkanols, trialkylorthoformatesIX.72 and epoxide reagents .The process of Claim 47, wherein said epoxide reagent is selected from the group consisting of ethylene oxide, i3.IX.72 propylene oxide, epichlorohydrin and the diglycidyl ether of isopropylidenediphenol. 49 . The textile of Claim 32 , wherein said copolycon- densed vinylphosphonate has been substantially neutralized by being reacted with a neutralizing amount of a reagent selected from the group consisting of alkanols, trialkylorthoformates and 13 .9.72 epoxide reagents.The textile of Claim 9, wherein said epoxide.72 reagent is selected from the group consisting of ethylene oxide, propylene oxide, epichlorohydrin and the diglycidyl ether of isopropylidenediphenol . I3.9.72 51 · The resin oompocitioa of Claim 37 , wherein said co- polycondensed vinylphosphonate has been substantially neutralized, 52 . The resin composition of Claim 51 , wherein said copolycondensed vinylphosphonate has been substantially neutralized by being reacted with a neutralizing amount of a reagent selected from the group consisting of alkanols, trialkylortho- 3 · 9· 72 formates and epoxide reagents . 53 · The resin of Claim , wherein said epoxide reagent is selected from the group consisting of ethylene 3 ·9 · 72 oxide, propylene oxide, epichlorohydrin and the diglycidyl ether of isopropylidenediphenol. C- '¾ JI 0 ·9·72 5 . A copolycondensed vinylphosphonate, according to Claim 1, resulting from the reaction between bis(2-chloroethyl) vinylphosphonate and tris(2-chloroethyl) phosphate.A copolycondensed vinylphosphonate, according to Claim 1, resulting from the reaction between bis(2-chlor0ethyl) vinylphosphonate and trimethyl phosphate.The textile of Claim 26, wherein said copolycondensed vinylphosphonate comprises the reaction product of bis(2-chloroethyl) vinylphosphonate and tris(2-chloroethyl ) phosphate.The textile of Claim 26, wherein said copolycondensed vinylphosphonate comprises the reaction product of bis(2-chloroethyl) vinylphosphonate and trimethyl phosphate.The resin oompooition of Claim y , wherein said copolycondensed vinylphosphonate comprises the reaction product of bis(2-chloroethyl) vinylphosphonate and tris(2-chloroethyl) phosphate .The resin compocitrion of Claim 37 wherein said copolycondensed vinylphosphonate comprises the reaction product of bis(2-chloroethyl) vinylphosphonate and trimethyl phosphate. 40350/2· 6θ. The resin composition of Claim 9> wherein said copolycondensed vinylphosphonate comprises the reaction product of bis(2-chloroethyl) vinylphosphonate and dimethyl methyl-phosphonate .The addition product of Claim 42, wherein said copolycondensed vinylphosphonate comprises the reaction product of bis(2-chloroethyl) vinylphosphonate and dimethyl methyl-phosphonate .The addition product of Claim 42, wherein said copolycondensed vinylphosphonate comprises the reaction product of bis(2-chloroethyl) vinylphosphonate and tris(2-chloroethyl ) phosphate. 6j. The addition product of Claim 42, wherein said copolycondensed vinylphosphonate comprises the reaction product of bis(2-chloroethyl) vinylphosphonate and trimethyl phosphate.The compound compoundA copolycondensed phosphonate rnmpnai Ml on comprising at least one of each of the units having the structure: 40350/1 - 77 -A copolycondensed vinylphosphonate according to Claim 1 obtained by reaction between a (2-haloalkyl) vinylphosphonate and at least one pentavalent phosphorus ester R0P(»0)XY where R has the same meaning as in Claim 1 and X and Y are selected from phenyl and phenyloxy.A process for flame retardin textiles according to Claim 9 wherein a copolycondensed vinylphosphonate according to Claim 66 is used as the flame retarding agent.A flame retarding textile according to Claim 26 in which the fire retardant resin is a polyc ndensed vinylphosphonate according to Claim 66.A flame retardant polymeric resin composition according to Claim 37 containin moieties of at least one copolycondensed vinylphosphonate according to Claim 66.A halogenated addition product of a copolycondensed vinylphosphonate accordin to Claim 42, comprising a copolycondensed vinylphosphonate according to Claim 6