Flame retardant compositions

Abstract

Flame retardant compositions that are halogen-free or substantially halogen-free are disclosed. In certain examples, the compositions comprise a polyphenylene ether, a halogen-free or substantially halogen-free polyepoxide, and one or more phosphorated compounds. Prepregs, laminates, molded articles and printed circuit boards using the compositions are also disclosed.

1 . A composition comprising:
 about 20% to about 55% by weight of a polyphenylene ether;   about 10% to about 40% by weight of a halogen-free polyepoxide or a substantially halogen-free polyepoxide; and   about 10% to about 30% by weight of a phosphorated compound.   
     
     
         2 . The composition of  claim 1  further comprising a compatibilizing agent and a catalyst. 
     
     
         3 . The composition of  claim 1  in which the polyepoxide comprises at least one bisphenol polyglicydyl having an average of at most one aliphatic hydroxy group per molecule. 
     
     
         4 . The composition of  claim 1  in which the phosphorated compound provides a flame retardant amount of chemically combined phosphorous that is about 3% to about 10% phosphorous by weight based on the weight of the composition. 
     
     
         5 . The composition of  claim 4  in which the flame retardant amount of chemically combined phosphorous that is about 4% to about 8% phosphorous by weight based on the weight of the composition. 
     
     
         6 . The composition of  claim 5  in which the flame retardant amount of chemically combined phosphorous is about 6.6% phosphorous by weight based on the weight of the composition. 
     
     
         7 . The composition of  claim 1  in which the polyphenylene ether is a compound with two or more structural units having a formula of: 
       
         
           
           
               
               
           
         
       
       wherein each R 1  and R 2  is independently selected from the group consisting of hydrogen, primary or secondary lower alkyl, primary or secondary lower alkenyl, primary or secondary lower alkynyl, phenyl, aminoalkyl, diaminoalkyl, acyl, and hydrocarbonoxy. 
     
     
         8 . The composition of  claim 1  in which the halogen-free polyepoxide is a compound having a formula of: 
       
         
           
           
               
               
           
         
       
       in which Q 1 , Q 2 , Q 3  and Q 4  each is independently selected from the group consisting of hydrogen, methyl, ethyl, propyl, ethylene, and propylene, and in which A 1  and A 2  each is independently selected from the group consisting of a monocyclic divalent aromatic radical, phenyl, unsubstituted phenylene, substituted phenylene, and phenoxy, in which Y is a bridging radical, methyl, ethyl, or propyl, in which m is 0 to 4, and in which n has an average value between 0 and 4. 
     
     
         9 . The composition of  claim 8  in which n has an average value of about 1. 
     
     
         10 . The composition of  claim 1  in which the halogen-free polyepoxide is a compound having a formula of 
       
         
           
           
               
               
           
         
       
       in which R 3 , R 4 , R 5 , and R 6  each is independently selected from the group consisting of hydrogen, methyl, ethyl, ethylene, propyl, and propylene, and in which n has an average value between 0 and 4. 
     
     
         11 . The composition of  claim 10  in which R 3 , R 4 , R 5  and R 6  are each hydrogen and n has an average value of about 1. 
     
     
         12 . The composition of  claim 1  in which the phosphorated compound is an organic phosphate. 
     
     
         13 . The composition of  claim 1  in which the phosphorated compound has a formula of 
       
         
           
           
               
               
           
         
       
       in which R 10 , R 11  and R 12  each is independently selected from the group consisting of alkyl, aryl, and alicyclic and heterocyclic groups that include nitrogen, oxygen and/or phosphorous. 
     
     
         14 . The composition of  claim 13  in which R 10 , R 11 , R 12  each is independently selected from the group consisting of primary or secondary lower alkyl, primary or secondary lower alkenyl, primary or secondary lower alkynyl, aryl, and alicyclic and heterocylic groups that include nitrogen, oxygen and phosphorous. 
     
     
         15 . The composition of  claim 2  in which the compatibilizing agent is one or more transition metal salts. 
     
     
         16 . The composition of  claim 15  in which the transition metal salt is a zinc salt or a tin salt. 
     
     
         17 . The composition of  claim 16  in which the zinc salt is selected from the group consisting of zinc octoate, di-alkyl zinc dicarboxylates, zinc mercaptides, zinc acetate, zinc oxide, zinc citrate, zinc oxylate, zinc acetylacetonate, zinc stearate, zinc naphthenate and mixtures thereof. 
     
     
         18 . The composition of  claim 16  in which the tin salt is selected from the group consisting of stannous octoate, di-alkyl tin dicarboxylates, tin mercaptides, stannous acetate, stannic oxide, stannous citrate, stannous oxylate, stannous chloride, stannic chloride, tetra-phenyl tin, tetra-butyl tin, tri-n-butyl tin acetate, di-n-butyl tin dilaurate, dimethyl tin dichloride, and mixtures thereof. 
     
     
         19 . The composition of  claim 2  in which the catalyst is selected from the group consisting of imidazole, 1-methyl imidazole, 1,2-dimethylimidazole, 2-methylimidazole, 2-heptadecylimidazole, 2-ethyl-4-methylimidazole, 2-undecylimidazole, 1-(2-cyanoethyl)-2-phenylimidazole, diethyltoluenediamine, tris(dimethylaminomethyl)phenol, 3-phenyl-1,1-dimethyl urea and mixtures thereof. 
     
     
         20 . The composition of  claim 1  having a glass transition temperature of at least about 140° C. 
     
     
         21 . The composition of  claim 1  having a peel strength of at least about 4 lb/inch width as tested by IPC-TM-650 2.4.8C. 
     
     
         22 . The composition of  claim 1  comprising about 43% by weight of at least one polyphenylene ether. 
     
     
         23 . The composition of  claim 22  comprising about 32% by weight of at least one halogen-free polyepoxide 
     
     
         24 . The composition of  claim 23  comprising about 25% by weight of at least one phosphorated compound. 
     
     
         25 . The composition of  claim 1  having a dielectric constant at 1 MHz (50% weight resin) of no greater than about 5.0 as tested by IPC-TM-650 2.5.5.3C. 
     
     
         26 . The composition of  claim 1  having a dielectric dissipation factor at 1 MHz (50% weight resin) of no greater than about 0.02 as tested by IPC-TM-650 2.5.5.3C. 
     
     
         27 . The composition of  claim 1  further comprising an effective amount of an initiator. 
     
     
         28 . The composition of  claim 27  in which the initiator is selected from the group consisting of benzoyl peroxide, 2,2′-azo-bis-isobutyrylnitrile, lauroyl peroxide, tert-butyl peroxy-2-ethylhexanoate and tert-amyl peroxy-2-ethylhexanoate. 
     
     
         29 . The composition of  claim 1  in which the polyphenylene ether has been equilibrated with a bisphenol selected from the group consisting of diglycidyl ether bisphenol-A type epoxides, bisphenol-F type epoxides, epoxidized novolac type epoxides, phosphorated epoxides, and cycloaliphatic epoxides. 
     
     
         30 . The composition of  claim 1  further comprising one or more fillers selected from the group consisting of talc, clay, mica, silica, alumina, Fuselex, Minusil 5, spodumene, and calcium carbonate. 
     
     
         31 . A halogen-free or substantially halogen-free composition comprising a flame retardant amount of chemically combined phosphorous and having a glass transition temperature of at least about 140° C. 
     
     
         32 . The halogen-free or substantially halogen-free composition of  claim 31  further comprising a polyphenylene ether. 
     
     
         33 . The halogen-free or substantially halogen-free composition of  claim 32  further comprising a halogen-free or substantially halogen-free polyepoxide. 
     
     
         34 . The halogen-free or substantially halogen-free composition of  claim 33  further comprising a compatibilizing agent and a catalyst. 
     
     
         35 . The halogen-free or substantially halogen-free composition of  claim 33  in which the flame retardant amount of chemically combined phosphorous is about 3% to about 10% phosphorous by weight based on the weight of the halogen-free or substantially halogen-free composition. 
     
     
         36 . A halogen-free or substantially halogen-free composition comprising a flame retardant amount of chemically combined phosphorous providing a peel strength of at least about 4 lb/inch width as tested by IPC-TM-650 2.4.8C. 
     
     
         37 . The halogen-free or substantially halogen-free composition of  claim 36  further comprising a polyphenylene ether. 
     
     
         38 . The halogen-free or substantially halogen-free composition of  claim 37  further comprising a halogen-free or substantially halogen-free polyepoxide. 
     
     
         39 . The halogen-free or substantially halogen-free composition of  claim 38  further comprising a compatibilizing agent and a catalyst. 
     
     
         40 . The halogen-free or substantially halogen-free composition of  claim 38  in which the flame retardant amount of chemically combined phosphorous is about 3% to about 10% phosphorous by weight based on the weight of the halogen-free or substantially halogen-free composition. 
     
     
         39 . A halogen-free or substantially halogen-free composition comprising a flame retardant amount of chemically combined phosphorous and having a dielectric constant at 1 MHz (50% resin content) of about 5.0 or less as tested by IPC-TM-650 2.5.5.3C. 
     
     
         40 . The halogen-free or substantially halogen-free composition of  claim 39  further comprising a polyphenylene ether. 
     
     
         41 . The halogen-free or substantially halogen-free composition of  claim 40  further comprising a halogen-free or substantially halogen-free polyepoxide. 
     
     
         42 . The halogen-free or substantially halogen-free composition of  claim 41  further comprising a compatibilizing agent and a catalyst. 
     
     
         43 . The halogen-free or substantially halogen-free composition of  claim 41  in which the flame retardant amount of chemically combined phosphorous is about 3% to about 10% phosphorous by weight based on the weight of the halogen-free or substantially halogen-free composition. 
     
     
         44 . A halogen-free or substantially halogen-free composition comprising a flame retardant amount of chemically combined phosphorous and having a dielectric dissipation factor at 1 MHz (50% resin content) of about 0.02 or less as tested by IPC-TM-650 2.5.5.3C. 
     
     
         45 . The halogen-free or substantially halogen-free composition of  claim 44  further comprising a polyphenylene ether. 
     
     
         46 . The halogen-free or substantially halogen-free composition of  claim 45  further comprising a halogen-free or substantially halogen-free polyepoxide. 
     
     
         47 . The halogen-free or substantially halogen-free composition of  claim 46  further comprising a compatibilizing agent and a catalyst. 
     
     
         48 . The halogen-free or substantially halogen-free composition of  claim 46  in which the flame retardant amount of chemically combined phosphorous is about 3% to about 10% phosphorous by weight based on the weight of the halogen-free or substantially halogen-free composition. 
     
     
         49 . A halogen-free or substantially halogen-free composition comprising a flame retardant amount of chemically combined phosphorous and having a flame retardancy of V-0 as defined by the UL-94 burn test. 
     
     
         50 . The halogen-free or substantially halogen-free composition of  claim 49  further comprising a polyphenylene ether. 
     
     
         51 . The halogen-free or substantially halogen-free composition of  claim 50  further comprising a halogen-free or substantially halogen-free polyepoxide. 
     
     
         52 . The halogen-free or substantially halogen-free composition of  claim 51  further comprising a compatibilizing agent and a catalyst. 
     
     
         53 . The halogen-free or substantially halogen-free composition of  claim 51  in which the flame retardant amount of chemically combined phosphorous is about 3% to about 10% phosphorous by weight based on the weight of the halogen-free or substantially halogen-free composition. 
     
     
         54 . A prepreg comprising a substrate impregnated with the composition of  claim 1 . 
     
     
         55 . A prepreg comprising a substrate impregnated with the composition of  claim 49 . 
     
     
         56 . A laminate comprising a first substrate stacked on a second substrate, wherein at least one of the first and second substrates comprises the composition of  claim 1 . 
     
     
         57 . A laminate comprising a first substrate stacked on a second substrate, wherein at least one of the first and second substrates comprises the composition of  claim 49 . 
     
     
         58 . A laminate comprising at least two of the prepregs of  claim 54 . 
     
     
         59 . A laminate comprising at least two of the prepregs of  claim 55 . 
     
     
         60 . A molded article comprising a plurality of layers wherein at least one of the plurality of layers is impregnated with the composition of  claim 1 . 
     
     
         61 . A molded article comprising a plurality of layers wherein at least one of the plurality of layers is impregnated with the composition of  claim 49 . 
     
     
         62 . A printed circuit board comprising a dielectric substrate impregnated with the composition of  claim 1  and having an electrically conductive layer on at least one surface of the dielectric substrate. 
     
     
         63 . A printed circuit board comprising a dielectric substrate impregnated with the composition of  claim 49  and having an electrically conductive layer on at least one surface of the dielectric substrate. 
     
     
         64 . A method of making a prepreg comprising disposing the composition of  claim 1  on a substrate. 
     
     
         65 . A method of making a prepreg comprising disposing the composition of  claim 49  on a substrate. 
     
     
         66 . A method of making a printed circuit board comprising:
 disposing the composition of  claim 1  on a substrate;   stacking the substrate and one or more additional substrates or layers; and   curing the stacked substrate.   
     
     
         67 . A method of making a printed circuit board comprising:
 disposing the composition of  claim 49  on a substrate;   stacking the substrate and one or more additional substrates or layers; and   curing the stacked substrate.   
     
     
         68 . A method of facilitating assembly of a prepreg, the method comprising providing the composition of  claim 1 . 
     
     
         69 . A method of facilitating assembly of a prepreg, the method comprising providing the composition of  claim 49 .