Unsaturated organo-tin mercaptide stabilizers for halo-vinyl polymers
United States Patent Bakassian [75] Inventor: Georges Bakassian, St. Foy Les Lyon, Rhone, France [73] Assignee: Rhone-Poulenc S.A., Paris, France [22] Filed: Dec. 7, 1973 [2]] App]. No.: 423,375  
  Related US. Application Data [62] Division of Ser. No. 350,122, April 11, 1973, Pat.  
 [30] Foreign Application Priority Data Apr. 12, 1972 France 72.12771 Mar. 14. 1973 France 73.09097 [52] US. Cl 260/45.75 S; 260/890 [51] Int. Cl. C08f 45/62 [58] Field of Search 260/45.75 K, 481  
 [56] References Cited UNITED STATES PATENTS 2.731.484 1/1956 Best 260/45.75 3.518.223 6/1970 Fath et a1 1260/4515 Apr. 22, 1975 Primary Examiner-V. P. Hoke Attorney, Agent, or FirmSteven, Davis, Miller &amp; Mosher [57] ABSTRACT Unsaturated organo-tin mercaptides, useful as stabilisers for halogenated vinyl resins, are obtained by reacting x mols of a mercaptocarboxylic acid HSXCOOH with y, mols of an alcohol HOYOH or mixture thereof with 2; mols of alcohol HOYOH and/or y mols of alcohol ROH, where X is C alkylene or phenylene, Y is C alkylene or cycloaliphatic of 5 or 6 ring carbons, each with ethylenic and/or acetylenic bonds but not more than 2 of each type of bonds, Y is C alkylene or cycloalkylene with 5 or 6 ring carbons, R is C alkyl or alkenyl, cycloalkyl or cycloalkenyl with 5 or 6 ring carbons, or phenyl (CH) alkyl, with .r, n; and y having specified inter-relationships, to form an intermediate, and reacting the intermediate with a tin component, which is z, mols of diorgano tin derivative R R SnO or R R SnC1 or mixture thereof with 3 mols of mono-organo tin derivative which is a stannoic acid monomer or polymer (R,SnO, R,SnCl ,R,Sn(OH)Cl or R,Sn(OH) C1 where R and R are C 0 alkyl and x, 1 and 1 have specified interrelationships.  
 7 Claims, No Drawings UNSATURATED ORGANO-TIN MERCAPTIDE STABlLlZERS FOR HALO-VINYL POLYMERS This is a division of application Ser. No. 350,122, filed Apr. 11, 1973 now US. Pat. No. 3,818,062.  
  This invention relates to organo-tin mercaptides which are particularly suitable for stabilising chlorinated vinyl resins.  
  It is known from French Patent Nos. 1,055,906, 1,085,807 and 1,138,451 that diorgano-tin mercaptides are good stabilisers for chlorinated vinyl resins, and especially for polyvinyl chloride. It has been recommended to use, in particular, saturated mercaptides such as dibutyl-tin or dioctyl-tin bis-(isooctylmercaptoacetate), these mercaptides currently forming the most effective stabilisers. However, these compounds are not completely satisfactory in some of their uses. Thus they do not prevent the appearance of a yellow colouration in the manufacture of transparent thin walled objects by high temperature extrusion. It is known that such a technique of extrusion will give high productivity only if the chlorinated vinyl resin compositions are heated to temperatures of 180 to 230C for short periods (e.g. 2 to minutes).  
  The present invention provides a process for the preparation of an unsaturated organo-tin mercaptide which comprises in step (a) reacting, to form an intermediate x mols of a mercaptocarboxylic acid of the formula:  
 HS X COOH with a hydroxylic component, which is y, mols of a compound of the formula HOYOH or a mixture thereof with at least one of y mols of a compound of formula HO-Y&#39;-OH and y mols of a compound of formula ROH, wherein X represents a straight or branched chain alkylene group of 1 to 4 carbon atoms, or a phcnylene group,  
 Y represents a straight or branched chain, aliphatic,  
 divalent hydrocarbon radical with at most carbon atoms, or a cycloaliphatic radical with 5 or 6 ring carbon atoms, the radical Y being divalent with at least one of an ethylenic and acetylenie bond and a maximum of two ethylenic and two acetylenie bonds,  
 Y represents an alkylene group with 1 to 10 carbon atoms, or a cycloalkylene group with 5 or 6 ring carbon atoms, R represents a straight or branched chain alkyl or alkenyl radical with at most 8 carbon atoms, a cycloalkyl or cycloalkenyl radical with 5 or 6 ring carbon atoms, or a phenylalkyl group, the alkyl substituent of which contains 1 to 4 carbon atoms, and x,y y and y, are subject to the following inequalities:  
  yl y and in step (b) reacting the intermediate with a tin component, which is;  
 Z1 mols of a diorgano-tin derivative of formula R R SnO or R,R SnCl or a mixture of 2, mols of the diorgano-tin derivative with Z2 mols of a monoorgano tin derivative, which is a stannoic acid monomer or a polymer thereof with recurring units of formula R,SnO or of formula R,SnCl R,Sn(Ol-1)Cl or R Sn(OH) Cl, wherein each of R and R which are the same or different, represents a straight or branched chain alkyl group with l to 10 carbon atoms, and x, Z] and 22 are subject to the following inequalities:  
 The organo-tin mercaptides produced according to the general process which has just been defined, have,  
 a complex structure and can contain in particular the following groups:  
 Usually the mereaptide contains 1 to 5 of such groups it being possible in particular for the latter to be bonded in such a way as to form monomeric, dimeric or oligomeric compounds. By way of illustration, the monomeric and dimeric forms have been represented as follows: i  
 dimeric form In the process of the invention as unsaturated diol HYOH and a diorgano-tin compound are reacted together. The use of each of the following reagents is optional, a saturated diol, a saturated or unsaturated monoalcohol and a monoorgano-tin derivative, each of the formula given above. Based on the general process, it is thus possible to define various processes for producing the mercaptides which are of different degrees of simplicity according to whether only one of the two reagents, the unsaturated diol or the diorgano-tin derivative, is partially replaced. The most complex process is that in which all the possible different variables are involved simultaneously. As is apparent from the above inequalities, the replacement of a part of the unsaturated diol is such that the proportion of hydroxyl groups provided by the saturated diol and/or the monoalcohol is at most equal to 50% of the overall sum of the hydroxyl groups present in the hydroxylic component. Furthermore, the tin-mercapto-ester group bonds (involving the sulphur atom) provided by the monoorgano-tin derivative form at most 25% of all the tinmercapto-ester group bonds formed from the diorganotin derivative and the monoorgano-tin derivative.  
  The compound which results from step (a) of the process, is an unstable compound which changes easily into a resinous substance. It is thus recommended not to attempt to isolate it, and to use it rapidly, as it is, for step (b). When y y and Z are 0, and z and y, are 0.5n, then this intermediate compound comprises in particular the a,w-dimercaptodiester of the formula:  
 optionally combined with a small proportion of secondary products of the formula:  
  It is recommended that the process according to the invention be carried out in a solvent which is not miscible with water, such for example, aliphatic, cycloaliphatic or aromatic hydrocarbons such as hexane, cyclohexane, petroleum ether, methylcyclohexane, benzene or toluene. The water formed during the reaction is advantageously removed e&#39;zg. by azeotropic distillation. In order to assist the esterification reaction of step (a), it is possible to add any known esterification catalyst, for example an acid such p-toluene-sulphonic acid or sulphuric acid. The conversion into a tin mercaptide is advantageously carried out by employing a dialkyltin oxide e.g. di-n-butyl or di-n-octyl-tin oxide, preferably with removal of water e.g. by azeotropic distillation. When a dichlorodialkylstannane is used, it is preferable simultaneously to introduce an agent for neutralising the hydrochloric acid liberated (e.g. ammonia or an amine).  
 Examples of the unsaturated diols, which can be used and which preferably have one or two ethylene bonds or one acetylene bond, are Z-butene-l ,4-diol, 2- pentene-l,5-diol, hexene-l,6-diol, octene-l,8-diol, lbutene-3,4-diol, l-pentene-3,4-diol, 2-pentene-l,4 diol, 2-hexene- 1,5-diol, 3-heptene-6,7-diol, 4-octene- 3,6-diol, 2-butyne-l,4-diol, 2-pentyne-l,4-diol, 3- hexyne-2,5-diol, l,5-hexadiene-3,4-diol, 4-octyne-3,6- diol, 2,6-octadiene-4,5-diol and 3-methyl-2,6-heptadiene-4,5-diol. Preferably 2-butene-l,4-diol is advantageous.  
  Examples of the mercaptocarboxylic acids are thioglycollic acid, B-mercaptopropionic acid, &#39;y-mercaptobutyric acid, S-mercaptovaleric acid, thiolactic acid, thiosalicylic acid, aand B-mercaptobutyric acids and B- and &#39;y-mercaptovaleric acids.  
  Examples of the saturated or unsaturated monoalcohols are isobutanol, n-butanol, isooctanol, octanol, cyclopentanol, cyclohexanol and phenyl ethyl alcohol. Preferably isobutanol, n-butanol, isooctanol, octanol are advantageous.  
  The unsaturated mercaptides prepared by the process of the invention can be used, after removal of the solvent, for stabilising halogenated vinyl resins and the present invention comprises compositions comprising such a resin and at least one of the unsaturated mercaptides. They are generally introduced into the resin to the extent of 0.2 to 3% by weight relative to the weight of resin. By halogenated vinyl resins there are to be understood, in accordance with terminology which is well known to those skilled in the art, polyvinyl chloride and its copolymers in which the part originating from vinyl chloride predominates. Examples of the compounds, which are suitable for copolymerisation with vinyl chloride, are vinyl esters such as vinyl acetate, vinyl bromide, vinyl fluoride and vinyl butyrate, vinyl ethers such as vinyl ethyl ether, acrylic acid and its derivatives such as ethyl acrylate, ethyl methacrylate, acrylonitrile, methacrylonitrile and acrylamide, allyl compounds such as allyl chloride and allyl acetate, and ethylenic compounds such as ethylene, propylene and butadiene.  
  The halogenated vinyl resin may be mixed with other polymers e.g. a styrene/butadiene/methyl methacrylate terpolymer for improving the impact resistance of the composition.  
  The mercaptides according to the invention have a greater retarding effect on yellowing than that of their saturated homologues. These mercaptides are thus very particularly suitable for producing thin films or transparent objects by extrusion or calendering techniques.  
 The Examples which follow illustrate the invention.  
 EXAMPLE 1 44 g of Z-butene-l ,4-diol are introduced slowly, over the course of 2 hours 30 minutes, into a flask containing 97 g of thioglycollic acid, 600 ml of toluene and l g of paratoluenesulphonie acid, the mixture having 5 been brought to the reflux temperature (112C). The water formed is removed completely by azeotropic distillation. When the esterification is complete, 180 g of di-(n-octyl)-tin oxide are added and the mixture is heated under reflux for 2 hours 15 minutes, with removal of the water formed during the reaction by azeotropic distillation. The toluene is finally removed by distillation and 235 g of organo-tin mercaptide are obtained, the identification of which was carried out in EXAMPLE 3 21.5 g of 2-butyne-l,4-diol and 250 ml of toluene are introduced into a flask and heated to the reflux temperature (l 10C), and a mixture containing 48 g of thioglycollic acid and 0.5 g of p-toluencsulphonic acid is particular by IR. spectrometry. The product consists Fun in ly e t e COUI&#39;SC f 1 hOur. The Water essentially of groups of the formula:  
 (approximately to determination by infra-red analysis).  
 [T 11 Sn L 1 C EXAMPLE 2 53 g of B-mercaptopropionic acid and 22 g of 2- butene-l,4-dio1 are reacted, in benzene, in accordance with the procedure of the preceding Example, and the reaction is continued until the water formed has been completely removed. 62 g of di-(n-buty1)-tin oxideare then added and the reaction is continued as in Example 1. 120 g of organo-tin mercaptide consisting essentially of groups of the formula:  
 (m coo 011 c c cir 000 on formed during the reaction is removed by azeotropic distillation, and then 62 g of dibutyl-tin oxide are added and the mixture is heated under reflux for minutes, removing the water formed by azeotropic distillation. After distillation of the toluene, 111 g of organo-tin mercaptide, consisting essentially of groups of the formula:  
 are obtained.  
 EXAMPLE 4 204 g of thioglycollic acid, 37 g of isobutyl alcohol, 70.5 g of 2-butene-1,4-diol, 1 g of p-toluenesulphonic acid and 1,000 cm of petroleum ether are introduced into a flask and heated to the reflux temperature (57C); the water formed is removed by azeotropic disare thus obtained.  
  This compound contains small proportions of groups of the formula:  
 tillation and then 251 g of dibutyl-tin oxide are added and the water formed is again removed by azeotropic distillation. After removing the solvent, 491 g of unsat- Sn 000 {0119 s cs cu CH CH2 s (mag coo (approximately 10 to 20%; determination by infra-red analysis).  
 urated organo-tin mercaptide, consisting essentially of groups of the formula:  
 Sn-S-CH -COO-CH -0H=Cl&#39;l-Cll -CCO-Cl1 -S and minutes on the calenders and the following samples every 3 minutes thereafter, and the colourations are 11 C noted (visual examination). The results are given in the l 3 following table: Sn-S-CH -C0O-CH -CH cn C H 4 9 Duration of Stabilised PVC resin heating at Unsaturated Unsaturated 180C in mercaptide mercaptidc are obtained 10 minutes Example 3 Example 4 5 colourless Colourless EXAMPLE 5 8 Colourless Colourless ll Colourlcss Colourless Various sample s based on polyvmyl chloride resin, 14 cmnurlcss colourless having the following composition, are prepared: 17 P1110 yellow Pale yellow 20 Pale yellow Pale yellow Commercial polyvinyl chloride, sold commercially l()() g under the tradenamc LUCOVYL BB 800 1 l i Styrene/hutadiene/mcthylmethacrylate terpolymer. 10g h h l d used as an additive to increase impact resistance A Compohltlon w K: Comprmc5 a Ogcndte 1,3-Butylene glycol ester of oxidised lignite wax, sold 1 g vinyl resin and, 21S stabiliser therefor, 0.2 to 3% by commercially under the tradename Wax E 20 l Stahiliser (diorganotin mcrcaptide) l g Welght of least one un5aturdted o gano-tin mercaptldc prepared by the process which comprises in step One of the following stabilisers is used for each mixllctmg. to form an intermediate, x mols of a merture; captoearboxyllc acid of the formula:  
  25 HS-XCOOH .sgflhmscr Thmprcpurcd in Example 1 with a hydroxylic component, which is mols of a Stfibiliser B: &#39;l&#39;hat prepared in Example 2. compound Of the formula HO-YOH O! a mixture Stabiliser C: Prepared according to Example 1. i  
  rcpmcing buwmdinl by Lmhummdm thereof with at least one of y mols of a compound of formula HOY -OH and y mols of a compound of Each mixture is melted in a two-roll mill, revolving at formula whercm X irepresents a Stralght or a speed of 15 revolutions/minute and heated to 180C branched cham alkylenc group of 1 to 4 carbon atoms (temperature maintained to within about 2). Samples or phcnylne f Y fcprcsems a Stmlght or are removed, the first after being worked for 5 minutes branched Cham, allphatlc, dlvalem hydrocarbon Padlon the cakmders and the f ll i samples every 3 cal Wltl&#39;l at most 10 carbon atoms, or a eycloaliphatic minutes thereafter, and the colourations are noted. The radlcal Wlth 5 or 6 Carbon atoms, the radical Y examination is carried out with the naked eye. The yelb61118 dlvalent with at least One Of an hylcnic and lowing numbers are also noted in accordance with the acetylenic bond and a maximum of two ethylenlc and Gardner scale, by means of a Lovibond comparison (W0 acetylenic bonds, represents an l yl n g oup disc. The results are given in the following table: With 1 t0 0 Car n at ms, Or a cycloalkylene group Duration of Stabilised PVC resin heating at Stabiliser A Stabilizer B Stabilizer C 180C in (Example 1) that of Example 2 (saturated homologue minutes of stabiliser A) appearance GARDNER appearance GARDNER appearance GARDNER number number number 5 Colourless 0 Colourless 0 Pale yellow 0 8 Colourless 0 Colourless 0 Light yellow 1 l l Colourless O Colourless 0 Yellow* 2 l4 Colourless 0 Colourless 0 Yellow* 2 l7 Pale yellow 0.5 Pale yellow 0.5 Yellow* 3 20 Pale yellow 0.5 Light yellow 0.5 Yellow* 4 increasing intensity These experiments show that the unsaturated orwith 5 or 6 ring-Carbon atoms, R pf a Straight gano-tin mercaptides have a greater heat stabilising efor branched Cham alkyl or k y radlcal Wlth at &#34;1 feet than the effect produced by the saturated homo- 8 Carbon atoms, 11 cycloalkyl or cycloalkenyl radical with 5 or 6 ring carbon atoms, or a phenylalkyl group, the alkyl substituent of which contains 1 to 4 carbon EXAMPLE 6 atoms, and x, y y and y are subject to the following Two stabilised polyvinyl chloride resin compositions equa tie are used as in Example 5 but with stabilisers A-C re- 2 placed by H 0.8K 2 Y Y 102 1 g of the stabiliser of Example 3 in composition and l g of the stabiliser of Example 4 in other composix tion. Each mixture is melted in a two-roll mill, revolving at y a speed of 15 revolutions/minute and heated to C. 0 2 O 25 (temperature maintained to within about 2C). Samplcs are removed, the first after being worked for 5 1 2 and in step (b) reacting the intermediate with a tin component, which is z, mols of a diorgano-tin derivative of formula R R SnO or R R SnCI or a mixture of z, mols of the diorgano-tin derivative with z: mols of a monoorgano-tin derivative, which is a stannoic acid monomer or a polymer thereof with recurring units of formula R,SnO,, or of formula R,SnCl R,Sn(OH)Cl, or R,Sn(OH) C|, wherein each of R, and R which are the same or different, represents a straight or branched chain alkyl group with l to carbon atoms, and x, Z and 2 are subject to the following inequalities:  
 oxide.  
  2. A composition according to claim 1 wherein the halogenated vinyl resin is polyvinyl chloride.  
  3. A composition according to claim 1 which comprises polyvinyl chloride or a mixture thereof with a styrenc/butadiene/methyl methacrylate tcrpolymer and, as stabiliser therefor, about 1% by weight of an unsaturated organo tin mercaptide prepared by a process which comprises in step (a) reacting, a mercaptocarboxylic acid, which is thioglycollic or B-mercaptopropionic acid, with a hydroxylic component, which is 2- butyne-l,4-diol, 2-butene-l,4-diol or a mixture of 2- butene-1,4-diol and isobutanol, in the presence of p-toluene-sulphonic acid to form an intermediate, and in step (b) reacting the intermediate with a tin compo nent which is di-(n-butyl) tin oxide or di-(n-octyl) tin 4. A composition according to claim 1 wherein z is 5. A composition according to claim 1 wherein y is 6. A composition according to claim 1 wherein y is O.  
  7. A composition according to claim 1 wherein Y contains one ethylenic or acetylenic bond.