Patented Dec. 26, 1950 2,535,643

UNITED STATES2,535,643 PATENT OFFICE . PROCESS OF PRE PARNG WNY, RESN PLASTCZED SHEETS Gerry P. Mack, Jackson Heights, N. Y., assignor to Advance Solvents and Chemical Corporation, s a corporation of New York No Drawing. Application July 22, 1947, Serial No. 762,819 Claims. (Cl. 260-31.8) This invention relates, in general, to poly clohexyl phthalate, which is made by esterifying vinyl halide compositions and, more particu One mol of phthalic anhydride with two mols of larly, to plasticizers which produce useful and cyclohexanol, has the property of being a high unusual properties when used in combination boiling plasticizer, which is highly suitable for with polyvinyl halide resins. nitrocellulose and other high polymers, but is It is well known that polyvinyl halide poly unsuitable as a plasticizer for polyvinyl halide mers or resins generally have to be plasticized polymers. In the first place, it is a highly crys with various materials before they can be used talline solid having a melting point of 58° C. successfully in manufacturing processes. This Secondly, when this ester is used in combination is particularly true in manufacturing what is 10 with polyvinyl halide resins it is not even com known as highly plasticized compositions which patible and gives white, opaque films instead of are used for self-supporting films made from clear transparent films as is desired for suitable polyvinyl halide compositions, as well as com plasticizers. positions to be used on cloth and paper and, I have now discovered a class of phthalic ester further, for extrusion purposes such as in the plasticizers which contain cyclohexanol, methyl manufacture of belts, hose, etc. In the past, it cyclohexanol and other hydroaromatic alcohols has been recognized generally that in order for in the radical but at the same time give good a plasticizer to be useful for use with polyvinyl plasticizing efficiency, are non-crystalline and halide compositions it not only must have high are well adapted to use with polyvinyl halide solvent power for such polyvinyl halides, but 20 resins. also have a high boiling point and low viscosity. In general, my class of plasticizers comprises Further, it has been generally assumed that if a mixed ester of phthalic anhydride in which the solvent power is low the plasticizing effect in the ratio of hydroaromatic alcohol is not more the compound is greatly decreased, the tensile than 1-1.2 mols to 1 mol of phthalic anhydride, strength is low and the plasticizers tend to exude the balance being an aliphatic alcohol having not from the compositions. The most commonly less than 4 carbon atoms. Practically, of course, used plasticizers have been esters, ketones and the product contains a mixture of the hydro eithers, but the greater proportion has been in aromatic diester and the hydroaromatic ali the esters and particularly esters of dicarboxylic phatic mixed diester. Such esters can be pre acids, such as sebacic, azelaic, adipic and phthal pared in the usual way; that is, phthalic anhy ic acids. Not all esters of these acids are suita dride is first esterified with the hydroaromatic ble as plasticizers however. alcohol to the desired extent and the residual The plasticizers based on phthalic anhydride carboxylic group is esterified with the aliphatic in order to be suitable for use with polyvinyl alcohol. After esterification is completed, which halide compositions must have a high boiling 35 can be determined by the usual laboratory point or low volatility so that when these com methods, the ester is stripped, bleached, etc., to positions are worked at elevated temperatures give a product which is non-crystalline and the plasticizer does not disappear nor volatilize which does not crystallize at room temperature. during processing. In general, in the phthalic Such esters are not only active plasticizers for esters used as plasticizers, the alkyl groups must 40 polyvinyl halide resins but are unique in the contain no less than 4 carbon atoms and pref respect that they have the desirable property of erably 8 carbon atoms in the molecule to be being very powerful plasticizers as the tempera suitable. Further, the alkyl group should be ture is gradually increased and at high tem preferably of a straight chain for maximum plas peratures are very active plasticizers which com ticizing efficiency. . 45 bine to give vinyl halide compositions which are It is well known that the normal Octyl group readily calendered and milled even though large is more suitable than the branched chain 2 quantities of this plasticizer are used. Addi ethylhexyl group and produces a better plasti tionally, such compositions do not become short cizer. nor crumbly on the calender or mill, which hap In the past, it also has been known that as 50 pens if the straight dialkyl ester of phthalic soon as a hydroaromatic radical is introduced anhydride is used, into phthalic esters the plasticizing efficiency is Compositions made with my new plasticizer greatly decreased and the products become crys have the usual chemical resistance as such poly talline instead of fluids of low viscosity which vinyl halide compositions and can be used for make suitable plasticizers. For instance, dicy 55 various purposes. Such compositions or stocks 2,535,843 3 4. can be made with varying physical properties I have discovered, the general formula can be depending on proportion of plasticizer used, al applied: though I prefer to use from 4 to 5 parts by weight of plasticizer to one of the resin. These COOR compositions can be compounded further with 5 the usual pigments and fillers that are ordinarily COOR used such as clay, barytes, titania, carbon black, whiting, etc. These are the types of fillers and where R represents one of the above hydroaro pigments which are usually used in the rubber matic radicals and R' one of the aliphatic radi and plastic industries and also may be used in It) cals. my composition. Further, stabilizers such as The following examples will illustrate the type complex tin salts like dibutyl tin diacetate, epoxy of compound and are purely for illustrative pur compounds such as glycidyl oleate, lead stearate poses and are not included for the purpose of and other metallo organic compounds which limiting the invention. function as stabilizers can be used in my con- 5 Eacample 1 positions. Further, my plasticizers can also be Monocyclohexyl phthalate, prepared from 1 used in combination with the other common mol phthalic anhydride and 1 mol cyclohexanol, plasticizers, such as phthalic, Sebacic, adipic, was further esterified using in. butanol until a fatty and other esters, to give other desirable neutral diester was obtained, which boiled at 210 properties associated with those plasticizers. 2?) 220° C. at 5 mm. pressure and had a saponifica As to the polyvinyl halide polymers, any of the tion value of 369. usual commercial polymers, such as polyvinyl Eacample 2 chloride, or copolymers of vinyl chloride with minor proportions of vinyl esters, such as vinyl 1 mol phthalic anhydride and 1 mol n. decanol acetate or vinyl cyanide, or acrylic esters, may 2, were reacted and the esterification completed us be satisfactorily plasticized with my compounds. ing cyclohexanol. The neutral diester obtained Specifically, in my phthalate esters the molar boiled at 268-278° C. at 5 mm. pressure and had ratio of hydroaromatic-aliphatic alcohols is pref a saponification value of 288. erably in the range of 1 to 1.2 mols of hydro Eacaraple 3 aromatic alcohols to 1 to 0.8 mols of aliphatic : ) As in Example 1, the monocyclohexyl phthalate alcohol per i mol of phthalic anhydride. was prepared and the esterification finished using As hydroaromatic alcohols, I can use cyclo 2 ethylhexanol. The neutral diester, which was hexanol, methyl cyclohexanol, dimethyl cyclo obtained after working up in the usual way the hexanol, ethyl cyclohexanol, cyclohexyl-cyclo crude product, boiled at 238 C. at 5 mm. having hexanol. Also, a saponification value of 31. Exocyclic hydroaromatic alcohols as: Eacample 4 Cyclohexyl carbinol In a similar manner, a neutral phthalic acid Cyclohexyl ethyl alcohol ester was prepared using 1.2 nos cyclohexanol Cyclohexyl propyl alcohol and 0.8 mois methyl isobutyl carbinol for mol Aliphatic alcohols such as: 4. phthalic anhydride. The crude ester was worked Butyl alcohol up and a neutral product was obtained boiling Amyl alcohol at 220-230 C, at 5 mm. pressure having a Sa Hexy alcohol ponification value of 338. Heptyl alcohol Octyl alcohol . Eacample 5 Decyl alcohol 1 mol phthalic anhydride was esterified using Sec. amyl alcohol a nola ratio of 1.2 nos cyclohexanol and 0.8 Methyl isobutyl carbino nois diisopropyl carbinol. The crude ester was Diisopropyl carbinol purified and the neutral diester boiled at 210 2 methyl pentanol-1. 5. 220 C. at 4 mm. pressure and had a Saponifica 2,4 dimethyl pentanol tion number of 327. 2,4 dimethyl hexanol-3 Eacample 6 Ether alcohols Such as: A neutral phthalic acid ester was prepared using Ethyleneglycol monomethyl ether imol of cyclohexanol and 1 no of butoxyethyl Ethyleneglycol monoethyl ether eneglycol. The neutral ester obtained after prop Ethyleneglycol monobutyl ether er purification boiled at 238 C. at 5 mm. pres Ethyleneglycol mono 2 ethylbutyl ether Sure and had a Saponification Value of 322. Also the corresponding diethyleneglcyol ethers To further illustrate the products of this inven are considered suitable. tion, the following table Summarizes the physi To further illustrate the type of plasticizer that cal constants of Some of the plasticizers prepared.

B. P. G. Sap. Crystal- Wiscosity Plasticizer 5 mm. walue liratinnpoint gcentipoise 25° C. in

oC. oC. Dicyclohexyl Phthalate------237 339 --58 Solid Cyclohexyn. Butyl Phthalate------20-220 - 369 -20 65 Cyclohexyl n. Decyl ------288-28 288 -25 65 Cyclohexyl 2 Ethyl Buty Phthalate----- 230 338 -12 225 Cyclohexy 2 Ethyl Hexyl Phthalate ---, 238 31 -5 25 Cyclohexyl Methyl Isobutyl Carbinyl

Phthalates:------propyl Carbinyl Phthal 220-230 338 -8 30 ate------20-220 37 -5 270 Cyclohexyl Butoxyethyl Phthalate------238 322 -8 65 8,585,848 6 The following examples further illustrate my to 5 parts of a plasticizer which is perse compati invention and the new properties of my plasticiz ble with and a solvent for said resin, Said plasti es: cizer being a mixed phthalate ester prepared by reacting 1 mol of phthalic anhydride with 1-1.2 Composition 5 mols of a hydroaromatic alcohol and 0.8-1 mol of an aliphatic alcohol having 4-12 carbon atoms. WYDR Resin.------...- Calcium Stearate-- 2. The process of claim 7 in which the hydro Stearic Acid.------aromatic alcohol is cyclohexanol and the aliphatic Dicyclohexyl Phthalate------Cyclohevyl Methyl Isobutyl alcohol is 2-ethyl hexanol. Carbinyl Phthalate------O 3. The process of claim 7 in which the hydro Cyclohexyl 2-Ethy Butyl aromatic alcoholis cyclohexanol and the aliphatic TricresylPhthalate------Phosphate------alcohol is n. butanol. 4. The process of claim 7 in which the hydro aromatic alcohol is cyclohexanol and the aliphatic 15 alcohol is n. decanol. 5. The process of claim 7 in which the hydro aromatic alcohol is cyclohexanol and the aliphatic T. S.------2,745 3,000 3, 150 Modulus G 100 per cent 2,000 1,600 1,780 alcohol is methyl isobutyl carbinol. Elongation, per cent---- 90 325 285 Set, per cent.------32 34 27 6. The process of claim 7 in which the hydro Shore Hardness 90 85 20 aromatic alcohol is cyclohexanol and the aliphatic Cold Crack, F -80 -40 0 alcohol is diisopropyl carbinol. Sheet Transparency - Opaque Clear Clear Clear 7. A process for preparing a clear, resilient, Dicyclohexyl phthalate was incompatible with Self-sustaining composition of matter which com the vinyl resin and gave a stiff white opaque sheet prises milling and calendering at a temperature on which it was impossible to conduct physical 25 of about 300 F. 1 part of a vinyl chloride-vinyl tests. acetate copolymer with 4 to 5 parts of a plas WYDR, is the trade name of Bakelite Corpora ticizer which is per se compatible with and a tion's polyvinyl chloride acetate (95% W. C.-5% Solvent for said resin, said plasticizer being a W. A.) resin with an intrinsic viscosity of 20° C. mixed phthalate ester prepared by reacting 1 mol of 1.25 in cyclohexanone. 30 of phthalic anhydride with 1-1.2 mols of a hydro The ingredients in the compositions given in aromatic alcohol and 0.8-1 mol of an aliphatic the above table were thoroughly blended as per alcohol having 4-12 carbon atoms. usual practice, then milled on a two-roll rubber GERRY. P. MACK. mill with a roll temperature of 300-312 F. and REFERENCES CTED then moulded for ten minutes at 305° F. The usual physical properties were then run on these The following references are of record in the specimens and the results are given in the above file of this patent: table. UNITED STATES PATENTS What is claimed is: 40 1. A process for preparing a clear, resilient, Number Name Date self-sustaining composition of matter which com 1643,393 Reid et al.------Sept. 27, 1927 prises milling and calendering at a temperature 2,384,521 Andersen et al. --- Sept. 11, 1945 of about 300' F. 1 part of a polyvinyl-chloride FOREIGN PATTENS acetate resin having an approximate intrinsic vis 45 Number Country Date cosity at 20 C. of 1.25 in cyclohexanone, with A 349,100 Great Britain ------May 21, 1931