[1]2 9 8 6 4 , 8 0 5 Uni'ted States.Patent Office 2,864,805 EPOXIDE RESINS 5 Harold G. Cooke, Jr., Lonisviiie, Ky., assignor to Devoe & Raynolds Company, Inc., Louisville, Ky., a corporation of New York No Drawing. Application December 5, 1955 Serial No. 550,841 10 8 Claims. (Ci. 260-47) This invention relates to the n@ anufaclure of epoxide 15 resins which are useful in the coating, mclding, adhesive and other fields, and includes the new epoxide resins and the Droc.=ss of producing them, and compositions and produc-,s made therewith. The n.-w epoxide resins of the present invention arc 20 prodv..ced from a mixture of cyanuric acid and a polyhydric phenol by a two-sta,-e process in which a mixture of cyantiric acid and a polyhydric phenol is first reacted with epichlorhydrin in the presence of a catalyst tcp form polyciilorhy dri-@i derivatives, which are then subjec,,ed to 25 dehydroha'i o.-enation to form the epoxide resins. The produc'Ls pro-duced will vary from products which are liquid and largely monomeric in character to products of a greater or less degree of polymerization. The proportions of eyanuric acid and of polyhydric 30 phenol used in the process, and for producing the new composite preducts, can be widely varied, e. g., from 85 parts of evanuric acid and 15 parts of dihydric phenol to 3 parts o-f cyanuric acid and 97 parts of dihydric phenol. In the first step of the process, in which a mixture of 35 polyhydric phenol, and -oarticularly o-f dihydric phenol, with cyanuric acid is reacted with epichlorhydrin in the presence of a catalyst, an organic solvent is also used. The epichlorhydrin reacts with both the dihydric phenol and the eyanuric acid to form polychlorhydrin derivativeq. 40 The proportions of epichlo-rhydrin used can be varied. For prodticts which are monomeric or largely monomeric in character, at least 3 rpols of epichlorhydrin are used for each mol of cyanuric acid, and at least I mol of epichlorhydrin for each ol. the phenolic hydroxyls of the 45 polyhydric phenol. In the production of polymeric products, somewhat lower proportions can be Lised. A particularly adva-@itageous method of carrying out the process, however, is the use of a large excess of epichlorhydrin , wbich also serves as the organic solvent, in 60 the first step of the process, since the use of such a large excess results in the production o-f products which are large.,y monomeric in character and which, on dehydroiialogenatio n, give liquid or low melting epoxide resins whicli are largely monomeric in character or of only a 55 limited degree of poly-,iierization or condensation. With lower ratios of epichlorhydrin to cyanuric acid and dihydric phenol an iner't or-anic solvent is used in the first step of t@ic process, and condensation or polymerization tends to take place to a somewhat greater ex- 60 tent aiid to give polychlorhydrin products of the first step which, on dehydrohalogenation, aive polymeric resins of higher melting po-ints. Products of varying properties, from liquid to high meltiripoint epoxide resins, can thus be produced b varyin- the proportion of cyanuric acid and dihydriy 65, c phenol in the first step of the procesg and also by varying the proportic.-.i of epichlorhydrin used in the first step of the process. 1-.q general, as the ratio of cyanuric acid to dihy4ric phenol increases, the resultin- epoxide resins become harder and, more brittle. 'j,he reaction is carried out by heating the reaction Patented Dec. 16, 1958 2 mixture at reflux temperature over a period of time varying from about one-half hour to about six hours, depending upon the proportions of the reactants. The catalysts which have been fbund advantageous for use in this reaction include tertiary amines such as tripropyl amine and dimethyl aniline; quaternary ammonium hydroxi.des, such as benzyl trimethyl ammonium hydroxide; quaternary ammonium salts such as benzyl trimethyl ammonium chloride; and quarternary ammonium ion-exchange resins. During this first step of the process, some dehydrohalogenation may take place to form epoxide groups that react with cyanuric acid groups or with hydroxyl groups of the dihydric phenol, with resulting formation of polymeric products or inter-reaction products, in which the cyanuric acid residues or the dihydric phenol residues are joined to.-ether or with each other through -CH=CHOH-CH2- groups. With lower proportiong of epichlo-rhydrin to cyanuric acid and dihydric phenol and with the use of an inert organic solvent, polymerization tends to take place to a somewhat greater extent than when a large excess of epichlorhydrin is used as the solvent. With the use of an excess of epichlorhydrin, monomeric products such as triglycidyl cyanurate and diglycidyl ethers of the dihydric phen6l will form to a considerable extent, and the r.-sulting products may be largely monomeric in character, Further reaction of condensation or polymerization may also take place, and the extent to which it takes place is greater where a large excess of epichlorhydrill is not used. Cyanuric acid has only a limited solubility in most organic solvents. But when it is admixed with a dihydi-ic phenol and with epichlorhydrin and an organic solvent, which may be an excess of epichlorhydrin, the finely divided cyaliuric acid in suspeiision gradually and progressively dissolves and reacts to form polychlorhydrin cyanilrates or reaction products with the dichlorhydrin ethers of the dihydric phenols or with epoxide groups that may be formed by dehydrohalo.-enation during the first step,of the process to form polychlorhydrin reaction products which are soluble in the solvent. Accordingly, the, simultaneous reaction of cyanuric acid and a polyhydric phenol with ep;chlorhydrin in the presence of a ratalyst gives a mixed or cornposite product containing polychlo-rhydrin derivatives which may be monomeric or polymeric and which may be composite in character, containing both cyanuric acid and polyhydric phenol nuclei. The second step of the process is the dehydrohalogenation of the polychlorhydri-@i derivatives produced by the first step. This dehydrohalcgenation of the polychlorhydrin derivative is effected with the use of basic reagents, and advantageous with the use of either anhydrous sodiurn hydroxide or an aqueous solution of sodium hydroxide. Other basic rea-ents such as potassium hydroxide, calcium hydroxide, sodium carbo-nate, etc., can also be iised in this step. The reaction of dehydrobalogenation is slightly exothermic, but can be controlled and kept below .1 00' C. by coolin.@ means such as indirect cooling by water. Water present in the reaction mixture is removed durin- or immediately following the dehydrohalogenation, by distillation of a part of the solvent. Byproduct salt and unreacted alkali are removed by filtration, and the product is isolated by removal of the solvent by vacuum distillation. The epoxide resins tbus obtained are polyglycidyl derivatives which will vary, depending upon the pro. portions of. cyanuric acid and dihydric phenol used, and also with the excess of epichlorhydrin used, from poly.9lycidyI derivatives which are liquids or low melting point solids and which are largely monomeric in character
[2]3 or contain consideiable @mounts of monomeric products, such as polyglycidyl cyanurates and diglycide -ethers @of dihydric phenols, together with varying amounts of products of further reaction or cohdensation or polymerization, to include high melting point solid epdxide resins. The composite epoiide resin products thus pr6du@ed will thus vary from@@liquid to high melting @oint solids and will 'also vafy in-@their epoxide equivalents, dependin.@ upon the extent to4which the polyinetic products or coniplex reaction products may be present in admixture with the monomeric products. The epoxide equivalent is the equivalent weight of the product per epoxide group. The method used @for determining the epoxide content comprises heating 1 gram sample of the product with an excess of pyridine containin.- pyridine hydrochloride (made by addln,- 16 cc. of concentrated hydrochloric acid per liter of pyridine) at the boiling point for 20 minutes and @ ba@k titratin- the excess pyridinehydrochloride with' 0.1 @N sodium hydroxid6, u i'ng phenolphthalein as! 'indicator, and considering that I HCI is equivalent to @l epoxide group. The present invention makes it possible to produce composite products from the reaction of cyanuric acid and diliydric phenol in varying proportioiis, whi@h vary from products which can be considered leirgely dihydric phenol @poxide resins modified with a small amb'un't of glycidyl cyanurate or reaction products thereof, to products which can be considered largely 'polyglycidyl cyanurates modified with a small amount of diglycidyl ethers of dihydric phenols and reaction products thereof, and includincomposite products containing both the cyanuric acid nucleus and the dihydric phenol nucleus in the same molecule. As the ratio of cyanuric acid to dihydric phenol initially used increases, epoxide resins are produced which, when cured, become harder and more brittle. The composite epoxide resins of the present invention have the advantage as epoxide resins that they are polyfunctional and in general contain an average of more than 2 epoxide groups per molecule. Polymeric products present in the composite resins will contairi intermediate alcobolic hydroxyi groups. Because of their polyfunctional reactive properties due to the number of reactive epoxide groups, these products are advantageously used for reaction with other compounds containing active hydrogen, to form higher molecular weight or crosslinked compounds including infusible and insoluble reaction products. Epoxide resins produced by the two-step prodess may contain varying amounts of chlorine, depending upon the extent to which the de hydrohalogenation is carried. The chlorine - conteilt of products produced by a single dehydrohalogenation treatment can be reduced by one or more subsequent treatments to give products of lower chlorine content and somewhat lower epoxide equivalent. The new epoxide resins are valuable epoxide resins which can be used for many purposes. They can be converted into molded or final insoluble and infusible products, by heating in the presence of a catalyst, e..g.' an amine catalyst, much the same as epoxide resins made from dihydric phenols. They have the advaritage over epoxide resins niade from dihydric ph&nols alone that'they have increased functionality and a higher ratio of epoxide 'groups per molecuie. Higher meltirig point epoxide resins can readily be produced from the liquid or low melting point resins by reacting them wiih further small amounts of dihydric pbenol or of cyanuric acid. The invention,will be further illustrated by the following -@pecific examples, but it will be understo6d 'that the inventi(in@is@not limited thereto. In . the 'ex@iriipl-6s, the parts are by weight. The apparattis'u@ed 'in catty- ing,out the @ptbce@s @6f @ the 'exaniples was @a thtee--iie'cked, 2,864,805 4 round-bottom flask equipped with thermometer, agitator, and reflux condenser. The first seven examples illustrate the production of liquid or low melting point epoxide resins which are monomeric or largely monomeric in character, with the use of a large excess of epichlorhydrin as the organic solvent and with varying ratios of cyanuric acid and dihydric phenol. Example I.-A mixture of 228 parts (I mol) of bis10 phenol, 16.5 parts (0.128 mot) of cyanuric acid, 1040 parts (11.28 mols) of epichlorohydrin and 6.3 parts of a 60% aqueous solution of benzyltrimethyl ammonium chloride was heated to 100' C. and held at 98 to 100' C. for 21/4 hours. At this time all the eyanuric acid had 15 dissolved and the reaction mixture was cooled. At 48' C. 100 parts of flake sodium hydroxide was added and the temp@- rature was raised to 75' C. A mixture of water and epichlorohydrin was removed by vacuurn distillation at a temperature of 58 to 75' C. 20 over a period of 12 minutes. Salt and unreacted alkali were removed by filtration and the remaining epichlorohydrin was removed by vacuum distillation. The product, 343 parts, was a viscous liquid having softening point of 13' C., a chlorine content of 0.8% 25 and an epoxide equivalent of 181.5. The product was obtained with a yield of 91% of theory. Example 2.-A mixture of 228 parts (I mol) of bisphenol, 49.5 parts (0.376 mol) of cyanuric acid, 1270 parts (13.76 mols) of epichlorohydrin and 7.6 parts of 30 a 60% aqueous solution of benzyltrimethyl ammonium cbloride was heated to 100' C. and held at 97 to 100' C. for 2V4 bours. The reaction mixture was cooled to 46' C. and 130 parts of,flake sodium hydroxide was added. The tem35 perature was raised to 75' C. and, under partial vacuum, a mixture of water and epichlorohydrin was removed by distillation at 58 to 80' C. The salt was removed by filtration and the remaining excess epichlorohydriri was removed by vacuum distillation. 40 The product, 440 parts, was a viscous liquid havin- a softening point of 22' C., a chlorine content of 2.6% and an epoxide equivalent of 179.5 The product was obtained in a yield of 97.2% of theory. 45 Example 3.-A mixture of 114 parts (0.5 mol) of bisphenol, 74 parts (0.57 mol) of cyanuric acid, 1260 parts (13@6 mols) of epichlorohydrin and 5.7 parts of a 60% aqueous'solution of benzyltrimethyl ammonilim chloride was heeited to 100' C. and held at 98 to 100' C. for 21/2 r3O hours. The reaction mixture was cooled to 40' C. and 1 10 parts of fldke sodium hydroxide was added. The temperature'vias raised to 53' C. and under partial vacuum a mixtiire of water and epichlorohydrin was removed 55 by distillation at 53 to 70' C. The salt was removed by filtration and the remaining epichlorohydrin was remov6d by vacuum distillation. The product (321 parts) had a softening point of 36' C., a chlorine content of 2.4% and an epoxide equiva60 lent of 166. The product was obtained in a yield of 94.5% of th,(,ry' Examplc 4.@A mixture of 228 parts (1 mol) of bisphenol, 7.8 parts (0.06 mol) of cyanuric acid, 980 parts 65 (10.6 mols) of epichlorohydrin and 6 parts of a 60% aqueo I us solution of benzyltrimethyl ammonium chloride was heated to 100' C. and held at 97 to 100' C. for 21/2 hours' The @reaction mixture was cooled to 40' C. and'90 parts 70 of flake sodium bydroxide was added. The temperature was raised to 70' C. and under partial vacuum a mixture of water and epichlorohydrin was removed by distillation tit 82-91' C. The salt was removed b3i filtraticin-and the remaining epichlorohydrin was removed 75 by vacuum distillation.
[3]5 Ile product, 357 parts, had a softening point of 13' C., a chlorine content of 1. 1 % and an epoxide equivalent of 186. The product was obtained in a 100% yield. Example 5.-A mixture of 64.5 parts (0.5 mol) of eyanuric acid, 11.1 parts (0.0475 mol) of bisphenol, 780 parts (8 mols) of epichlorohydrin and 2.75 parts of a 60% aqueous solution of benzyltrimethyl ammonium chloride was heated to 115' C. and held at 114 to 115' C. for 11/2 hours. Th,- reaction mixture was cooled to 33' C. and 32.8 parts o'L flake sodium hydroxide was added. The temperature was raised to 60' C. and held at 60 to 65' C. for 15 minutes. At 65' C. a second portion of 32.8 parts of flake sodium hydroxide was added and an exothermic reaction raised the temperature to 85' C. Heat was applied and a mixture of epichlorohydrin and water was distilled to a pot temperature of 105' C. The mixture was cooled and filtered to remove salt, and the remaining epichlorohydrin was removed by vacuum distillation. The product, 160 parts, had a softening point of 48' C., a chlorine content of 4.25% and an epoxide equivalent of 158. The product was obtain,-d in i 97% yield. Example 6.-A mixture of 110 parts (I mol) of resorcinol, 97 parts (0.75 mol) of cyanuric acid, 1620 parts (17.5 mols) of epichlorohydrin and 7.4 parts of a 60% aqueous solution of benzyltrimethyl ammonium chloride was heated to 115' C. and held at 114-115' C. for 2 hours. The mixture was cooled to 58o C. and 4 equal port;ons of 43.5 parts of flake sodium hydroxide were added over an interval of I hour at a temperature of 58-60' C. Following the last addition of sodium hydroxide, heat was applied and a mixture of water and epichlorohydrin was distilled to a pot temperature of 105' C. The mixture was cooled and filtered and the excess epichlorohydrin was removed from the filtrate by vacuum distillation. The product, 458 parts, was a viscous liquid having a softening point of 16' C., a chlorine content of 3.9% and an epoxide equivalent of 146. The product was obtained with a yield of 100%. Example 7.-A mixture of 34.2 parts (0.137 mol) of "Bisphenol-S" (p,p'- dihydroxydiphenyl sulfone), 64.5 parts (0.5 mol) of cyanuric acid, 826 parts (8.9 mols) of epichlorohydrin and 3.3 parts of a 60% aqueous solution of benzyltrimethyl ammonium chloride was heated to 113' C. and held at 113-115' C. for 3 hours. T'he reaction mixture was cooled to 48' C. and 73 parts of flake sodium hydroxide was added. An exothermic reaction raised the temperature to 80' C. and heat was applied to distill a mixlure of water and epichlorohydrin to a oot temperature of 105' C. The mixture was cooled and hltered and the excess epichlorohydrin was removed by vacuum distillation. The product, 199 parts, had a softening point of 461 C., a chlorine content of 4.3% and an epoxide equivalent of 168. In the above examples, the molecular ratio of cyanuric acid to dihydric phenol used varies from about 10 to 1 in Example 5 to about I to 17 in Example 4. On the 'assumption that the cyanuric acid is converted into monomeric triglycidyl cyanurate present either as such or in part as a product of further reaction or condensation, with either cyanuric acid or dihydric p@enol, the percentage of glycidyl eyan I urate, on that basis, would vary from around 90% in Example 5 and 75% in Example 7 to about 50% in Examples 3 and 6, 25% in Example 2, 10% in Example 1, and 5% in Example 4. In the following examples, an inert organic solvent is used with an amount of epichlorohydrin less than that corresponding to the OH groups of the dihydric phenol and eyati-lir;c acid, and the products produced are higher nieltin.- resins of a polymeric nature. 2,864,805 6 Example 8.-A mixture of 228 parts (I mol) of bisphenGI, 43 parts (0.33 mol) of cyanuric acid, 195 parts (2.1 mols) epichlorohydrin, 400 parts of dioxane and 3.5 parts of a 60% aqueous solution of benzyltrimethyl ammonium chloride was heated to reflux for 11/3 hours. At this time all the cyanuric acid was dissolved and the mixture was cooled to 63' C., 86 parts of flake sodium hydroxide was added and the reaction temperature was kept below 90' C. with a cold water bath. When 1 (, the exothermic reaction was complete, heat was applied and the mixture was held at reflux for 1/2 hour. The mixture was cooled to 80' C., filtered and the dioxane removed from the filtrate by vacuum distillation. The product, 375 parts, had a softening point of 871 C., 15 and an epoxide equivalent of 893. Yield 98% of theory. Example 9.-A mixture of 114 parts (0.5 mol) of bisphenol, 32.3 parts (0.25 mol) of eyanuric acid, 115.6 parts (1.25 mols) of epichlorohydrin, 250 parts of dioxane and 6.2 parts of a 35% methanol solution of 20 benzyltrimethyl ammonium hydroxide was heated to 100' C. and held at 100- 102' C. for 21/4 hours. The reaction mixture was cooled to 57' C. and 52 parts of flake sodium hydroxide was added. The mix25 ture was heated to 93' C. and held at 93-97' C. for 30 minutes, cooled and filtered to give 380 parts of a solution having a viscosity of D, color of 4 and percent solids of 54. 1 %. On a solids basis the product had a cblorine content I of.1.97% and an epoxide equivalent of 520. The solvent. @o was removed from a small sample of the solution in a vacuum oven at 95-100' C. to give a hard, brittle resin having a melting point of 115' C. Example IO.-A mixture of 110 parts (1 mol) of 35 resorcinol, 32.3 parts (0.25 mol) of cyanuric acid, 162 parts (1.75 mols) of epichlorohydrin, 250 parts of dioxane and 2.4 parts of dimethyl aniline was heated to 97' C. and held at 97 to 99' C. for 11/2 hours. The mixture was cooled to 55' C. and 72 parts of flake 40 sodium hydroxide was added. The reaction mixture was heated to 90' C. and held at 90-96' C. for 35 minutes, cooled and filtered to give 425 parts of a solution having a viscosity of E, color of 11 and percent solids of 55%. On a solids basis the product had a chlorine content of 2.28% and an epoxide equivalent of 787. The solvent 45 was removed from a sample of the solution in a vacuum oven at 95-100' C. to give a resinous solid having a softening point of 72' C. Example II.-A mixture of 83.3 parts (0.33 mol) of "Bisphenol-S" (p,p'-dihydroxydiphenyl sulfone), 43 parts -50 (0.33 mol) of cyanur;c acid, 123.3 parts (1.33 mols) of epichlorohydrin, 250 parts of dioxane and 2 parts of benzyldimethyl amine was heated to 98, C. and held at 98 to 100' C. for 6 hours. The reaction mixture was cooled to 55, C. and 55 55 parts of flake sodium hydroxide was added. The mixture was heated to 90' C. and allowed to reflux at 93 to 981 C. for 30 minutes, cooled and filtered to give a solution having a viscosity of C, color of 10 and percent solids of 52.1 %. 60 On a solids basis the product had a chlorine content of 3.68% and an epoxide equivalent of 402. A small sample of the solution was treated in a vacuum oven at 95-100' C. to -ive a hard brittle resin having a softening point of 97' C. "5 The epoxide resins produced as above described, when liquid in character, can be used together with a catalyst as coating compositions, as adhesives, as molding liquids, etc., either alone or admixed with other materials. The solid resins can similarly be used in solution for form70 ing coating compositions or in solid form for admixture with other materials, e. g., for making molded and other products. In general, the improved resins of the present invention can be used to replace liquid and solid epoxide resins 75 produced from dihydric phenols. But the resins have
[4]7 distinctive -properties and advantages because -of their composite nature. I
