NO149891B - MONOORGANOTINE OR DIORGANOTINE MERCAPTOAL CYLESTES OF A CARBOXYLIC ACID OR -CARCAPTOHYDROXYLYCYLESTES OF A CARBOXYLIC ACID MEMONO OR POLYSULPHIDE FOR USE AS HEAT STABILIZER - Google Patents

Description

The present invention relates to new monoorganotin or diorganotin mercaptoalkyl esters of carboxylic acids or -mercaptohydroxyalkyl esters of carboxylic acid mono- or polysulfides for use as heat stabilizers in chlorine-containing polymers. The compounds can also be termed mercapto-alkanol carboxylic acid esters or mercaptoalkyl carboxylates.

Present organotin compounds are characterized by having the general formula: where x is 1, 2 or 3; y is 1-6; z is 0-6; R 1 , 1 , R 3 , R 4 , R 5 and R 8 are C 1-6 alkyl, phenyl,

R 8 and R 8 are hydrogen or methyl; R 1 and R 2 - are hydrogen;

R 1 q is C 1 -C 1 -alkyl, benzyl or C 1 -C 1 -alkenyl; while Rg is methylene.

A typical starting ester for the production of organotin compounds according to the present invention is thus e.g. mercaptoethyl caprylate of the formula: which is different from the starting ester, i.e. e.g. isooctylthioglycolate having the formula:

and as e.g. used in the U.S. Patent No. 3,565,930 and U.S. Pat. patent No. 3,565,931. Thus, in the starting compounds used in the present invention, the free mercapto group reacts with a tin compound in the formation of compounds

according to the present invention, is bound to the alcohol part of the ester, while in the esters mentioned in the above-mentioned patents, it is bound to the acid part of the ester. This is very important because the compounds according to the present invention have a significantly better effect than those described in said U.S. patents. Firstly, they have far better stabilizing properties for vinyl chloride polymers and other halogen-containing polymers. This can already be noted in dynamic paint tests in the laboratory, but the advantage is even more marked during real expulsion tests. Furthermore, compounds according to the present invention have far better storage stability than the corresponding alkylthioalkanoates. The organotin mercaptoalkyl carboxylates described here also have a major advantage over organotin alkyl mercaptocarboxylates in that the stabilizers both have a longer lifetime and resistance to precipitation. Although the theoretical background is uncertain, it is assumed that the instability of alkyl mercaptocarboxylates is due to a hydrolysis of the ester function whereby an organotin mercaptocarboxylate ring or polymeric material is formed, after which this is precipitated. This is again due to the carboxylate anion having strong tin nucleophilicity. With mercaptoalkyl carboxylates, however, the nucleophilicity of the alcohol oxygen atom is not sufficient

to promote a rearrangement of the mercaptoalkyl alkanoate to form an insoluble ring or polymer product.

Samples exposed to air saturated with water vapor at 37°C showed only very weak formation of cloudy products when organotin alkyl mercaptocarboxylates were present, while storage under the same conditions with the corresponding alkylthioalkanoates created voluminous precipitates.

Details regarding the storage stability test are as follows: 50 gram samples were stored in open 50 cm<3> narrow-necked bottles in a closed chamber containing a 1.25 cm layer of water at the bottom. The chamber was placed in an oven and the temperature was varied, 5 days at 37°C and 2 days at room temperature from 10-21°C. This variation was carried out for a total of 60 days. After this trial period, approx. 50% of the alkylthioalkanoate present precipitated, while in contrast only approx. 1% of the mercaptoalkyl alkanoate present.

The alkylthioalkanoate and mercaptoalkylalkanoate used in this test had the following formula:

Compounds according to the present invention further have far less odor compared to the compounds described in the above U.S. Pat. patents.

It is important to have a sulphide group to achieve outstanding stabilizing properties. Thus, products according to the present invention are far better stabilizers than e.g. organotin compounds which are prepared by reacting methyltin trichloride (or dimethyltin dichloride) with 2-mercaptoethyl caprylate, i.e. tin compounds of the type described in U.S. U.S. Patent No. 2,731,482 U.S. Patent No. 2,731,484 Patent No. 2,870,119 and U.S. Pat. patent No. 2,870,182.

Compounds according to the present invention are used as stabilizers to improve the resistance to degradation in vinyl chloride polymers (e.g. vinyl chloride resins) when these are heated to 175°C. The compounds contain tin in amounts from 10 to 42 percent by weight, and sulfur in amounts varying from 8 to 42 percent by weight.

The preferred hydrocarbon radical attached to the tin atoms in the present compounds is methyl.

A mixture of monoorganotin compounds and diorganotin compounds is preferably used as stabilizers, especially mixtures containing from 96 to 50% of a monoorganotin compound and correspondingly 4 to 50% of the diorganotin compound. The individual compounds can also be mixed mono-diorganotin compounds, which will be apparent from the following specific examples.

Compounds according to the present invention are prepared in different ways, e.g. as shown below. One can thus use the method in the U.S. Patent No. 3,565,930 or in U.S. Pat. patent no. 3,565,931 by using alkali metal, alkaline earth metal or ammonium sulphides or polysulphides, e.g. Na £ „ S x , KZ 0S x , CaS x , BaS x or (NH^^S^^ where x is as defined above, instead of the alkali metal or alkaline earth metal monosulfides mentioned in the above U.S. patents and further using a compound of the following formula:

instead of isooctylthioglycolate or similar compounds of the type specified in the latter U.S. the patents. When one or more of the groups R-^, " R^ in R3 > R4 °9 R5 is: -SRg or a compound with the formula is also present: HSRg or One can thus react 1 mol of a compound with the formula with 1 moles of a compound of the formula: after which one neutralizes with an alkali or alkaline earth metal hydroxide in an amount corresponding to the mercaptoalkanol ester of the carboxylic acid, after which one carries out a reaction with ammonium or an alkali or alkaline earth metal sulphide. If the compound

is replaced by a compound with the formula

R-^-SnX-j, then 2 mol of the mercaptoalkanol ester must be used.

X can be a halogen atom with an atomic weight of 35-127.

When preparing compounds according to the present invention, numerous methods can be used as described in the following. Regardless of the method used, however, the reaction should be carried out at temperatures varying from room temperature to 100°C, usually at 25 - 50°C. The reaction can usually be carried out with water as a solvent regardless of the method used. You can also use water-immiscible organic solvents, e.g. aliphatic and aromatic hydrocarbons such as hexane, octane, benzene, toluene, xylene, aliphatic carboxylic acid esters etc., e.g. butyl acetate, propyl propionate and methyl valerate. The amount of solvent is not critical and can be varied within a large range.

If nothing else is stated, all parts and percentages are per weight in the following examples.

In the examples, the refractive index (R.I.) is measured at 25°C, unless otherwise stated. Illustrative methods include the following:

METHOD 1:

This is the general procedure of Kauder and Brecker except that sodium monosulfide, sodium disulfide, sodium trisulfide, sodium tetrasulfide, ammonium monosulfide, ammonium disulfide, ammonium trisulfide or ammonium tetrasulfide is reacted with an appropriate tin compound and appropriate -SH-containing compound or compounds as indicated above .

METHOD 2:

In this method, the sodium mono- or polysulfide (or potassium mono or polysulfide), water, mercapto-containing esters, hydrocarbon if this is desired and ammonium hydroxide are added to a reactor after which an aqueous solution of an alkyl tin halide, e.g. at temperatures from 25-35°C» The mixture was then heated, e.g. to ^ >0°C, the layers were separated after which the product was washed and dried.

PROCEDURE 3:

In this method, the mercapto-containing ester, water, an organic solvent and ammonium hydroxide are added to a flask, after which two solutions are simultaneously added, i.e. (A) an alkyltin chloride and (B) an alkali metal mono or polysulphide. The product is then separated, washed and distilled.

PROCEDURE 4:

This is the same method as method 3>, except that NaHCO 3 is used in the same molar amount as said ammonium hydroxide.

PROCEDURE 5:

In this method, alkyltin chloride, water and ammonium hydroxide are added to a flask, after which the mercapto-containing ester and an alkali metal mono- or polysulphide are simultaneously added.

PROCEDURE 6:

This method involves adding the mercapto-containing ester, water and ammonium hydroxide to a reactor, after which an alkyl tin chloride and then an alkali metal polysulphide or monosulphide are added slowly at 30°C. After heating to 45°C, the product is separated, washed and distilled.

These methods are described in more detail

in the U.S. patent No. 3,869,487. The entire method described there is thus included as a reference. The working examples in the aforementioned patent can be followed by completely or partially replacing the mercapto compounds that were used with mercapto compounds with the following formula:

Stabilizers according to the present invention

can be used with halogen-containing vinyl and vinylidene polymers, e.g. resins where the halogen atom is linked directly to the carbon atoms. Preferably, the polymer is a vinyl halide polymer, in particular

a vinyl chloride polymer. Usually, the vinyl chloride polymer is made from monomers consisting of either vinyl chloride alone or a mixture of monomers where vinyl chloride makes up at least JO weight percent. When vinyl chloride copolymers are stabilized, preferably the copolymer of vinyl chloride with an ethylenic unsaturated compound copolymerizable with vinyl chloride should contain at least 10% polymerized vinyl chloride.

As the chlorinated polymer, chlorinated polyethylene can be used with from 14 to 75%, e.g. 27% by weight chloride, chlorinated natural and synthetic rubber, rubber hydrochloride, chlorinated polystyrene, pchlorinated polyvinyl chloride, polyvinyl chloride, polyvinylidene chloride, polyvinyl bromide, polyvinyl fluoride, copolymers of vinyl chloride with from 1 to 90%, preferably from 1 to 30% of a copolymerizable ethylenic , unsaturated compound such as vinyl acetate, vinyl butyrate, vinyl benzoate, vinylidene chloride, diethyl fumarate, diethyl maleate, other alkyl fumarates and maleates, vinyl propionate, methyl acrylate, 2-ethylhexyl acrylate, butyl acrylate and other alkyl acrylates, methyl methacrylate, ethyl methacrylate, butyl methacrylate and other alkyl methacrylates, methyl-a- chloroacrylate, styrene, trichloroethylene, vinyl ethers such as vinyl ethyl ether, vinyl chloroethyl ether and vinyl phenyl ether, vinyl ketones such as vinyl methyl ketone and vinyl phenyl ketone, 1-fluoro-2-chloroethylene, acrylonitrile, chloroacrylonitrile, allylidene diacetate and chlorallylidene diacetate. Typical copolymers include vinyl chloride-vinyl acetate (96:4 sold commercially as VYNW), vinyl chloride-vinyl acetate (87:13), vinyl chloride-vinyl acetate-maleic anhydride (86:13:1), vinyl chloride-vinylidene chloride (95:5)» vinyl chloride- diethyl fumarate (95:5)> vinyl chloride-trichloroethylene (95:5)» vinyl chloride-2-ethylhexyl acrylate (80:20).

The stabilizers according to the present invention can be added to the polymer by mixing the polymer and the stabilizer in a suitable mill or mixer or by means of other well-known methods which provide uniform distribution throughout the polymer composition. The mixture can thus be carried out by rolling at 100-160°C.

In addition to the new stabilizers, the resin can also be supplemented with usual additives such as softeners, pigments, fillers, dyes, ultraviolet absorbents, thickeners and the like. You can also add common and known tin stabilizers, e.g. of the type described in the U.S. Patent Nos. 3,565,930, 3,869,487, 3,640,950, 2,870,119, 2,870,182, 2,731,484, 2,731,482 and 2,914,506, e.g. These patents are thus included as a reference here.

If softeners are used, these are used in normal amounts, e.g. from 10 to 150 parts per 100 parts polymer. Typical plasticizers are di-2-ethylhexyl phthalate, dibutyl sebacate, dioctyl sebacate, tricresyl phosphate.

The tin-containing stabilizers according to the present invention are usually used in amounts of from 0.01 to 10 percent by weight of the polymer, more preferably 0.2 to 5 percent by weight of the polymer.

You can also add 0.1 - 10 parts of a metal salt stabilizer per 100 parts of the halogen-containing polymer.

One can thus use barium, strontium, calcium, cadmium, zinc, lead, tin, magnesium, cobalt, nickel, titanium and aluminum salts of phenols, aromatic carboxylic acids, fatty acids or epoxy fatty acids.

Examples of suitable salts include barium di-(nonylphenolate), strontium di(nonylphenolate), strontium di(amylphenolate), barium di(octylphenolate), strontium di(octylphenolate), barium di(nonylphenolate -cresolate), lead di(octylphenolate), cadmium 2-ethylhexoate, cadmium laurate, cadmium stearate, zinc caprylate, cadmium caprate, barium stearate, barium 2-ethylhexoate, barium laurate, barium ricinoleate, lead stearate, aluminum stearate, cadmium naphthenate, cadmium benzoate, cadmium -p-tert.butyl benzoate, barium octyl salicylate, cadmium epoxy stearate, strontium epoxy stearate, cadmium salt of epoxidized acids of soybean oil and lead epoxy stearate.

In plastisol preparations, it is also preferred to add from 0.1 to 10 parts of an epoxy vegetable oil per

100 parts of the polymer. One can e.g. use an epoxidized soybean* oil or epoxidized tall oil, epoxy esters of fatty acids, e.g. isooctylepoxystearate. In the following examples, monoalkyltin-tris(mercaptoalkanyl)alkanoates and dialkyltin-bis(mercaptoalkanyl)alkanoates and the like are mentioned, because even if they do not form part of the present invention, their use in admixture with compounds according to the present invention will be a part of the present invention. Mono- and polysulfides according to the present invention can also be prepared by reacting ammonium and/or alkali metal mono- or polysulfide with such mono- and dialkyl tin mercapto-alkanyl alkanoates. EXAMPLE 1 204 g (1.0 mol) of 2-mercaptoethyl caprylate, 200 ml of water, 84 g (1.0 mol) of sodium bicarbonate and 100 ml of heptane were added to a 2 liter flask. The mixture became at ^ 0-/\. 0°C added dropwise 110 g (0.5 mol) of dimethyltin dichloride dissolved in 200 ml of water. The mixture was stirred for one hour at "} 0-/\. 0°C and two layers were obtained. The organic layer was washed with 200 ml of water and then distilled under vacuum at approximately 100°C. A yield of 273 S dimethyltin bis(2-mercaptoethyl caprylate). n^ 1.5060. ;EXAMPLE 2 ;A 2 liter flask was charged with 306 g (1.5 mol) of 2-mercaptoethyl caprylate, 200 ml of water, 126 g (1.5 mol ) sodium bicarbonate and 300 ml of heptane. To the mixture was added at 40° C. 120 g (0.5 mol) of monomethyltin trichloride dissolved in 150 ml of water. After the addition, the mixture was stirred for one hour at 30-40° C. The layers were separated, and the organic phase washed with 200 ml of water. The heptane was removed under vacuum to give 363 g of monomethyl-ti-nn-tris(2-mercaptoethyl caprylate) as a clear, colorless liquid, n<g5> 1.5041.; EXAMPLE 3 ; To a 2 liter flask was added 516 g (1.5 mol) of 2-mercaptoethyl stearate, 200 ml of water, 126 g of sodium bicarbonate and 500 ml of heptane.The mixture was heated at 40-50°C with 120 g (0.5 mol) of monomethyltin trichloride dissolved in 150 ml of water The mixture was then stirred for an hour at ^. 0~^ 0°C and two layers were obtained. The organic layer was separated and washed with 200 ml of water and then distilled under vacuum at 100°C. A yield of 560 g of monomethyltin tris(2-mercaptoethyl)stearate was obtained as a white solid, melting point 44-47°c. EXAMPLE 4 430 g (1.25 ml) of 2-mercaptoethyl stearate, 200 ml of water, 69 g (0.65 mol) of sodium carbonate and 300 ml of heptane were added to a 2 liter flask. At 30-40°C, 55 g (0.25 mol) of dimethyltin dichloride and 60 g (0.25 mol) of monomethyl tin trichloride dissolved in 150 ml of water were added to the mixture. The mixture was then stirred for one hour at the aforementioned reaction temperature, and two layers were separated. The organic phase was washed with 200 ml of water and then distilled under vacuum at approx. 100°C, and this gave 493 g of a colorless oil. The product was a mixture of monomethyl-dimethyltin-tris,bis-(2-mercaptoethylstearate). Melting point 36-40°C. EXAMPLE 5 A 2 liter flask was charged with 102 g (1.5 mol) of 2-mercaptoethyl acetate, 200 ml of water, 300 ml of heptane and 120 g (0.5 mol) of monomethyltin triclDDide. 126 g (1.5 mol) of sodium bicarbonate were added portionwise to the mixture and the temperature was maintained at 25-40°C during the addition. The mixture was then stirred for one hour at 25-40°C. The layers were separated and the organic phase washed with 200 ml of water. The heptane was then removed under vacuum. A yield of 240 g of monomethyltin-tris(2-mercaptoethyl acetate) was obtained as a colorless oil. n^ 1.5575. EXAMPLE 6 513 g (1.5 mol) of 2-mercaptoethyl oleate, 200 ml of water, 126 g of sodium bicarbonate and 500 ml of heptane were added to a 2 liter flask. The mixture was then added at 25-35°C with 120 g (0.5 mol) of monomethyltin trichloride dissolved in 150 ml of water. The mixture was then stirred for one hour at 25-35°c °g two layers were separated on standing. The organic layer was washed with 200 ml and then distilled under vacuum at 100°C. Monomethyltin-tris(2-mercaptoethyl oleate) was produced in a yield of $9,815 as a pale, yellow oil. n^<5> 1.5008 ;EXAMPLE 7 ;The procedure from example 2 was repeated using 142 g (0.50 mol) of monobutyltin trichloride instead of the mentioned monomethyltin trichloride. The yield was 383 g of a colorless oil consisting of monobutyltin-tris(2-mercaptoethyl caprylate). rff 1.5061. ;EXAMPLE 8 ;The procedure from Example 1 was repeated using 52 g (0.125 m°D dioctyltin dichloride and 85 g (0.25 m°D monooctyltin trichloride instead of dimethyltin dichloride. The yield was 297 g of a pale yellow oil consisting of dioctyltin bis (2-mercaptoethyl caprylate) and monooctyltin-tris(2-mercaptoethyl caprylate). ;nj<p> 1.5001 ;EXAMPLE' 9 ;To a 2 liter flask was added 204 g (1.0 mol) of 2-mercaptoethyl caprylate, 200 ml of water, ^00 ml of heptane and 120 g (0.5 mol) of monomethyltin trichloride. To the mixture was then added 80 g (1.0 mol) of a 50% aqueous NaOH solution at 25-35° C. Stirring was continued for one hour at said conditions and two layers were separated, and the organic layer was distilled under reduced pressure and 273 S of a pale yellow oil was obtained. The product essentially consisted of monomethyl monochlorotin bis(2-mercaptoethyl caprylate). njp 1.5244. ;EXAMPLE 10 ;A 2 liter flask was added with 286 g (1.5 mol) of mono-thioglycerin diacetate ester, 200 ml of water, 126 g of sodium bicarbonate; and 500 ml of hep tan. At 40-50°C, 120 g (0.5 mol) of monomethyltin trichloride dissolved in 150 ml of water was added to the mixture. The mixture was stirred for one hour at 40°C and the layers were separated. The organic layer was washed with 200 ml of water and distilled under vacuum at 100°C. A yield of 328 g was obtained consisting essentially of monomethyltin tris(monothioglycerin diacetate) as a thick oil. nj<p> 1.5310. EXAMPLE 11 120 g (0.5 mol) of monomethyltin trichloride dissolved in 200 ml of water was added to a 2 liter flask. The whole was heated to 30°c and 204 g (1.0 mol) of 2-mercaptoethyl caprylate were added. Then 80 g (1.0 mol) of a 50% aqueous sodium hydroxide solution was added dropwise at 30-40°C. The mixture was stirred for one hour. After this, a solution prepared by heating 32.5 g (0.25 mol) of 60% aqueous Na2S and 8.0 g (0.25 ml) of sulfur in 100 ml of water was added dropwise. The addition was carried out at 25-35°C. After stirring for one hour at 35°C, the product layer was separated and washed with 200 ml of water. The product was then distilled to 100°C under vacuum, and a 100% yield of a pale yellow oil was obtained. The product is essentially bis(methyltin-di-2-mercaptoethylcaprylate) disulfide. <n>j<p><1,>5<2>79. EXAMPLE 12 The procedure from Example 11 was repeated using 32.5 g (0.25 ml) of 60% aqueous sodium sulphide instead of the formed (0.25 mol) sodium disulphide, and the corresponding monosulphide was produced. The yield was 277 g of a pale yellow oil, njp 1.5269. EXAMPLE 13 The procedure from Example 11 was repeated using 96 g (0.4 mol) methyltin trichloride, 33 g (0.15 mol) dimethyltin dichloride instead of the aforementioned methyltin trichloride. The yield was 285 g of a pale yellow oil which essentially consisted of (monomethyltin-di(2-mercaptoethylcaprylate))(dimethyltinmono(2-mercaptoethylcaprylate)) disulfide. n£p 1.5258. EXAMPLE 14 120 g (0.50 mol) of monomethyltin trichloride in 200 ml of water were heated to 30°C and 204 g (1.00 mol) of 2-mercaptoethyl caprylate were added, after which 31 g (0.5 mol) were slowly added 28 fo ammonium hydroxide. The mixture was stirred for one hour. 125 g (0.25 mol) of 20% aqueous ammonium disulfide solution were then added over 30 minutes at 25-35°C. The mixture was heated to 50°C and the lower product layer was separated from the aqueous phase. The product was washed with 200 ml of water and dried at 100°C at 2 mm Hg absolute pressure. A quantitative yield of a pale yellow oil was obtained. The product is essentially bis(monomethyltin-bis(2-mercaptoethyl caprylate)) disulfide. n^ 1.5288. ;EXAMPLE 15 ;A 2 liter flask was added 32.5 g (0.25 mol) ;60% anhydrous sodium sulfide and 8.0 g (0.25 mol) sulfur dissolved in ;100 ml water, 300 ml heptane, 150 ml water, 218 g (1.0 mol) of 2-mercaptoethyl pelargonate and 61 g (1.0 mol) of 28% aqueous ammonium hydroxide. A mixture of 96 g (0.4 mol) methyltin trichloride and 33 g (0.15 mol) dimethyltin dichloride dissolved in 150 ml water was then added. The mixture was then held at 50°C for 30 minutes, the layers were separated and the product layer was washed and dried at 100°C under vacuum. The product (99%) essentially consisted of bis(methyl/dimethyl-tin-mono/di(2-mercaptoethyl geragonate)) disulfide. ;n£5 1.5245- ;EXAMPLE 16 ;The procedure from example 15 was repeated using 32.5 g (Of25 mol) of 60% aqueous sodium sulphide instead of the formed sodium disulphide, whereby the corresponding monosulphide was obtained. Yield 296 g of a pale yellow oil. n^p 1.5222. ;EXAMPLE 17 ;A 2 liter flask was added with 300 ml of heptane, 91 g (1.5 mol) of 28% aqueous ammonium hydroxide, 200 ml of water and 218 g (1.0 mol) of 2-mercaptoethyl pelargonate. A mixture of 120 g (0.5 mol) of methyltin trichloride dissolved in 150 ml of water was then added. The mixture was heated to 35°C and kept at this temperature for 30 minutes, the layers were then separated after which the product layer was washed and dried at 100°C under reduced pressure. The product of 206 g was bis(monomethyltin-bis(2-mercaptoethyl pelargonate)) oxide, njp 1.5197. EXAMPLE 18 120 g (0.5 mol) of methyltin trichloride dissolved in 200 ml of water was added to a 2 liter flask. The mixture was heated to 30<G>C and 163.5 g (0.75 mol) of 2-mercaptoethyl pelargonate was added. 60 g (0.75 mol) of 50% aqueous sodium hydroxide solution was then added dropwise at 30-40°C. The mixture was then stirred for one hour. A solution prepared by heating 2.5 g (0.25 mol) of 60 ml of aqueous Na2S and 100 ml of water at 25-35°0 was then added, the mixture was stirred for one hour, the layers were separated and the product layer was washed with 200 ml of water . The organic layer was distilled to 100°C under vacuum to give 240 g of a pale yellow oil containing fmonomethylmonochlorotin-2-mercaptoethyl polargonate) [monomethyltin bis(2-mercaptoethyl polargonate)) sulphide. <n>j<p><1,>5<2>93. EXAMPLE 19 120 g (0.5 mol) of methyltin trichloride in 200 ml of water was added to a 2 liter flask. The mixture was heated to 30°C and 153 g (0.75 mol) of 2-mercaptoethyl caprylate and 5°.5 g (0.25 mol) of lauryl mercaptan were added. 6l g (1.0 mol) of 28% aqueous ammonium hydroxide was then added dropwise at 30-40°C. The mixture was then stirred for one hour. A solution of 32.5 g (0.25 mol) of 60% aqueous sodium sulphide in 100 ml of water at 35°C was then added. Stirring was then carried out for one hour, the layers were separated and the organic layer was washed with 200 ml of water. The organic phase was distilled to 100°C under vacuum, and 269 g of a yellow oil was obtained which essentially contained [monomethyltin-bis(2-mercapt©;-ethylcaprylate)} [monoethyltin—mono(2-mercaptoethylcaprylate )mono -lauryl mercaptide] sulfide, n<2>^ 1.5267. EXAMPLE 20 The same procedure as in Example 19 was used, but 51 g (0.25 m°D isooctylthioglycolate was used instead of lauryl mercaptide. The yield was 272 g of a pale, yellow oil, i.e. [monomethyltin bis(2-mercaptoethyl caprylate) ) (monomethyltin-mono(2-mercaptoethylcaprylate)monoisooctylthioglycolate] sulphide, n2^ 1.5278. ;EXAMPLE 21 ;The same procedure as in example 19 was used, but 54»5 g (0>25 mol) of isooctylmercaptopropionate and 0.25 m°l of sodium disulfide instead of the aforementioned lauryl mercaptan and sodium sulfide, respectively. A yield of 274 g of ®n yellow oil was obtained which consisted of [monomethyltin-bis(2-mercaptoethylcaprylate)) [monomethyltin-mono (2-mercaptoethylcaprylate)monoisooctylmercaptopropionate) disulfide. n<2>5 1.5266. EXAMPLE 22 The same procedure as in example 19 was used, but 36 g (0.25 mol) of 2-ethylhexoic acid was used instead of lauryl mercaptan. The yield was 251 g of a yellow oil containing [mono-methyltin-bis (2-mercaptoethyl caprylate)] [monomethyltin-mono(2-mercaptoethyl caprylate) mono (2-ethylhexoate)) sulphide, n^ p 1.5214. ;EXAMPLE 23 ;The procedure from example 15 was repeated using 258 g (0.75 m°D 2-mercaptoethyl stearate and 57 g (°i25 mol) isooctyl maleate instead of the aforementioned (1.0 mol) 2-mercaptoethyl pelargonate. A low-melting white solid, m.p. 38-43°C weighing 37O g, and the product consisted essentially of (monomethyltin-bis(2-mercaptoethylstearate)) [monomethyltin-mono(2-mercaptoethylstearate)monoisooctylmaleateJ disulfide, n<2>^ 1 ,5193. ;EXAMPLE 24 ;A 2 liter flask was charged with 204 g (1.0 mol) 2-mercaptoethyl caprylate, 102 g (0.5 mol) isooctylthioglycolate, ;200 ml water, 300 ml heptane and 126 g (1.5 mol) sodium bicarbonate. A solution of 120 g (0.5 mol) methyltin trichloride in 150 ml of water was added dropwise at 25-30° C. After the addition, the mixture was stirred for one hour at 40° C. and two layers were separated The organic phase was washed with 200 ml of water and distilled under vacuum at 100° C. A yield of ;366 g was obtained which essentially consisted of monomethyltin-bis(2-merc aptoethyl caprylate )monoisooctylthioglycolate as a pale yellow oil, ;n25 1.5103. EXAMPLE 25 120 g (0.5 mol) of monomethyltin trichloride dissolved in 200 ml of water was added to a 2 liter flask. The mixture was heated to 30°C and 80 g (1.0 mol) of 50% aqueous sodium hydroxide solution was added dropwise at this temperature. The mixture was then stirred for one hour, after which a solution of 32>5 g (0.25 mol) of 60% aqueous sodium sulphide in 100 ml of water was added dropwise at 25~35°C. After stirring for one hour at 35°C, the product layer was separated and washed with 200 ml of water. The product was distilled to 100°C under vacuum, and a 100% yield of a yellow oil was obtained. The product is essentially bis(methyltin di(2-mercaptoethyl tallate)) sulphide. n<25> 1.5168. EXAMPLE 26 785 g (1.0 mol) methyltin tris(2-mercaptoethyl pelargonate) and 120 g (0.5 mol) methyltin trichloride were added to a 2 liter flask. The mixture was stirred at 50°C for one hour. The resulting product, a clear and colorless oil (905 g), is essentially monomethyl monochlorotin bis(2-mercaptoethyl pelargonate). ;nj<p> 1.5248. EXAMPLE 27 7^5 g (1.0 mol) of monomethyltin tris(2-mercaptoethyl pelargonate), 248 g (1.0 mol) of dibutyltin oxide and 750 ml of toluene were added to a 3-ball flask. The mixture was stirred and kept at 100°C for 2 hours, and a clear solution was obtained. The solvent was removed under vacuum to give 1016 g of a pale yellow oil. ;Monomethyltin bis(2-mercaptoethyl pelargonate)mono(2-mercaptoethyl oxydibutyltin pelargonate) has a refractive index at 25°C of 1 1.5069. EXAMPLE 28 120 g (0.5 mol) of monomethyltin trichloride dissolved in 200 ml of water was added to a 2 liter flask. The solution was heated to 30°C and 197 g (1.0 mol) of 2-mercaptoethylphenyl acetate was added. It was then added dropwise at 30-40°C approx. 80 g (1.0 mol) 50% aqueous sodium hydroxide. The mixture was then stirred for one hour. A solution of 32.5 g (0.25 mol) of 60% sodium sulphide dissolved in 100 ml of water was then added dropwise at 30-35°C. After stirring for one hour, a product layer was separated which was washed with 200 ml of water. The product was distilled under vacuum, and a 100% yield of a yellow oil was obtained. 270 g of bis(monomethyltin-bis(2-mercaptoethylphenylacetate)) sulphide, n^ p 1.6122. EXAMPLE 29 83 g (0.5 mol) of methylstannoic acid, 273 g (1.5 mol) of 2-mercaptoethyl benzoate and 500 ml of toluene were added to a 3-necked flask. The mixture was refluxed for 3 hours, cooled to 30°C and filtered. The organic layer was removed by vacuum distillation at 100°C, and 322 g of a white solid was obtained. The solid consists essentially of monomethyltin-tris(2-mercaptoethylbenzoate), melting point 263-267°C. EXAMPLE 30 28l g (1.0 mol) of monobutyltin trichloride dissolved in 400 ml of water was added to a 2 liter flask. The solution was heated to 30°C and 43% (2.0 mol) 2-mercaptoethyl pelargonate was added. 169 g (2.0 mol) of 50% aqueous sodium hydroxide were then added dropwise at 30-35°C. The mixture was stirred for one hour, and 65 g (0.5 mol) of sodium sulphide (60%) dissolved in 100 ml of water was added dropwise at 40°C. After stirring for one hour at this temperature, a product layer separated which was washed with 400 ml of water. The product was then vacuum distilled to 100°C and 617 g of a pale yellow oil, bis(monobutyltin-bis(2-mercaptoethyl pelargonate)) sulphide was obtained. n<25> 1.5219. ;EXAMPLE 31 ;A 2 liter flask was added with 281 g (1.0 mol) of butyltin trichloride dissolved in 400 ml of water. The solution was heated to 30°C and 101.5 g (0.5 mol) of isooctylthioglycolate and 327 g (1.5 mol) of 2-mercaptoethyl pelargonate were added. 122 g (2.0 mol) ammonium hydroxide (28%) was then added dropwise at 35-40°C. The mixture was stirred for one hour at 35-40°C. Then 64 g (0.5 mol) of ammonium sulphide (40%) were added and the mixture was stirred for one hour. A product layer was then separated which was washed with 400 ml of water and dried under vacuum at 100°C. A total of 596 g of a yellow oil (monobutyltin bis(2-mercaptoethyl geragonate)) - ;(monobutyltin (isooctylthioglycolate) (2-mercaptoethyl geragonate)) - sulphide was obtained. n<25> 1.5211. EXAMPLE 32 A 2 liter flask was added with 28 l g (1.0 mol) of butyltin trichloride dissolved in 400 ml of water. The solution was heated to 30°C and then 305 g (1.5 mol) of 2-mercaptoethyl caprylate was added. 120 g (1.5 mol) of 50% aqueous sodium hydroxide was then added dropwise at 30-40°C and the mixture was stirred for one hour at the aforementioned temperature. 65.0 g (0.5 mol) of 60% Na2S dissolved in 100 ml of water were then added, and the mixture was stirred for one hour at 30-40°C. The layers were separated and the product layer was washed with 400 ml of water, distilled under vacuum at 100°C. The product (mono-butyl monochlorotin(2-mercaptoethyl caprylate)) (monobutyltin-bis(2-mercaptoethyl caprylate j) sulphide was obtained in a yield of 98 f° as a yellow oil. n<25> 1.5276. ;EXAMPLE 33 ;En 2 liter flask was added 240 g (1.0 mol) of monomethyltin trichloride dissolved in 400 ml of water. The solution was heated to 30° C. and 218 g (1.0 mol) of 2-mercaptoethyl pelargonate and 109 g (0.5 mol) of isooctyl mercaptopropionate were added. Then 120 g (1.5 mol) of 50% aqueous sodium hydroxide solution was added dropwise at 25-30°C and the whole was stirred for one hour.Then 65.0 g (0.5 mol) of 60% sodium sulphide dissolved in 100 ml of water and stirred the mixture for one hour at 30-40° C. The layers were separated, the organic layer was then washed with 400 ml of water and purified by vacuum distillation at 100° C. The product which was 474 g of a pale yellow oil was essentially a mixture of (methyltin-bis(2-mercaptoethylpelargonate)J [monomethylmonochlorotin(isooctylmercaptopropionate)] sulphide and [monomethyltin(isooctylmercaptopropion nat)- ;(2-mercaptoethyl geragonate)) (monomethylmonochlorotin(2-mercaptoethyl geragonate)) sulfide. n2<5> 1.5288. EXAMPLE 34 240 g (1.0 mol) of monomethyltin trichloride dissolved in 400 ml of water was added to a 2 liter flask. The solution was heated to 30°C and 218 g (1.0 mol) of 2-mercaptoethyl pelargonate was added. Then 80 g (1.0 mol) of 50% aqueous sodium hydroxide were added dropwise and stirred for one hour at 25-35°C. Then 65 g (0.5 mol) of 60% sodium sulphide dissolved in 150 ml of water were added and the mixture was stirred in one hour at 35°C The layers were separated, the organic phase was then washed with 400 ml of water and distilled under vacuum to 100°C. The product, bis(monomethyltin(2-mercaptoethylpelargonate)) bisulfide was obtained in 96.5% yield as a pale yellow oil. n<25> 1.5630. Example 35 240 g (1.0 mol) of monomethyltin trichloride dissolved in 400 ml of water was added to a 2 liter flask. The solution was heated to 35°C and 660 g (2.0 mol) of 2-mercaptoethyl oleate was added. 160 g (2.0 mol) of 50% aqueous sodium hydroxide was then added dropwise at 35°C. The mixture was then stirred for one hour. 65 g (0.5 mol) of 60% sodium sulphide dissolved in 150 ml of water at 30-35°C were then added. After stirring for one hour, the product layer was separated and washed with 400 ml of water, distilled at 100°C under vacuum, and 788 g of a pale amber colored oil was obtained. The product essentially consisted of bis[monomethyltin bis(2-mercaptoethyl oleate) sulphide. n2^ 1.51<1>8. ;EXAMPLE 36 ;A 3-necked flask was charged with 120 g (0.5 mol) of methyltin trichloride in 150 ml of water, 109 g (0.5 mol) of 2-mercaptoethyl pelargonate and 200 ml of toluene. The mixture was heated to 30°C and then 40 g (0.5 mol) of 50% aqueous sodium hydroxide was added dropwise and then 43 g (<0>»33 mol) of 60% Na2S dissolved in 75 ml of water was added in portions. The mixture was stirred at 30-4-0°C for one hour. The layers were separated and the organic phase distilled at 100°C under vacuum, and 190 g of a colorless oil was obtained. n<2>^ 1.5336»; It is assumed that the product has the following structure: ;118.5 g (0.1 mol) of the above compound was added to 200 ml of water and 43»5 g (°»2 m°D 2 -mercaptoethyl pelargonate. At 25°C, 16 g (0.2 mol) of 50% aqueous sodium hydroxide were then added dropwise to the mixture. The reaction mixture was stirred for one hour at 25-30°C and two layers were separated. The organic layer was separated and washed with 100 ml of water and distilled at 100°C under vacuum. The resulting product which was 142 g of a colorless oil had a n2^ refractive index of 1.5286. The structure is assumed to be as follows: ;EXAMPLE 37 ;En 3 -necked flask was added 150.5 g (0.5 mol) of phenyltin trichloride, 300 ml of water, 400 ml of benzene and 218 g (1.0 mol) of 2-mercaptoethyl plargonate. The mixture was added dropwise at 40°C to 80 g (1 .0 mol) 50 fo aqueous sodium hydroxide. After stirring for one hour at 40°C, 32.5 g (0.25 mol) of 60% sodium sulphide dissolved in 75 ml of water were added dropwise. After stirring for one hour at 40°C, two layers are separated, and the organic layer was dried and purified under vacuum to 100°C. The resulting product bis(mono-phenyl-bis(2-mercaptoethyl pelargonate)) sulfide was obtained in a yield of 312 g as a pale yellow oil. n2^ 1.5517. EXAMPLE 38 120 g (0.5 mol) of monomethyltin trichloride dissolved in 200 ml of water was added to a 2 liter flask. The solution was heated to 30°C and 218 g (1.0 mol) of 2-mercaptoethyl pelargonate was added. 80 g (1.0 mol) of a 50% aqueous sodium hydroxide solution were then added dropwise at 30-40°C. The mixture was then stirred for one hour. A solution prepared by heating 32>5 g (0.25 mol) of 60% sodium sulfide and 16 g (0.5 mol) of sulfur in 150 ml of water was then added. The addition took place in portions at 30-40°C. Stirring was continued for one hour, and a separated layer was obtained, after which the product layer was washed with 200 ml of water. The organic phase was distilled to 100°C under vacuum and 296 g of a pale yellow oil containing bis[monomethyltin-bis(2-mercaptoethyl geragonate)) trisulphide was obtained. n<25> 1.5290 ;EXAMPLE 39 ;A 3-ball flask was added 169 g (0.5 mol) of monooctyltin trichloride, J>00 ml of water, /\. 00 ml of benzene and 204 g (1.0 mol) of 2-mercaptoethyl caprylate. The mixture was kept at 30-40°C and then 80 g (1.0 mol) of 50% aqueous sodium hydroxide was added dropwise. Stirring was continued for one hour and a solution of 32>5 g (0.25 mol) of 60% aqueous sodium sulphide dissolved in 100 ml of water was added dropwise. Stirring was continued for a further hour and the layers were separated and the organic layer distilled at 100°C under vacuum. The resulting pale yellow oil weighing 320 g is bis[mono-octyltin-bis(2-mercaptoethyl caprylate)) sulphide, njp 1.5144. EXAMPLE 40 A 3-necked flask added 79.5 g (<0>.33 mol) of monomethyltin trichloride, 147»5 g (0.67 mol) of dimethyltin dichloride dissolved in 250 ml of water, as well as 454 g (1»33 mol) of 2-mercaptoethyl oleate. The solution was heated to 30°C and 106 g (1.33 mol) of 50% aqueous sodium hydroxide was added dropwise at 30°C over the course of one hour. The reaction mixture was then stirred for an additional hour. It was then added dropwise added 65 g (0.5 mol) of 60% sodium sulfide dissolved in 100 ml of water and the mixture was stirred for one hour. The layers were separated and the organic layer washed with 200 ml of water and distilled to 100°G under vacuum. resulting product of 577 g is a yellow oil, probably a mixture of bis(monomethyltin-bis(2-mercaptoethyl oleate)) sulfide, bis(dimethyltin-mono(2-mercaptoethyl oleate )) sulfide and (monomethyltin-bis(2-mercaptoethyl oleate)) [dimethyl-tin-mono (2-mercaptoethyloleate)) sulphide. n<2>^ 1.5070. ;EXAMPLE 41 ;A 3-necked flask was charged with 120 g (0.5 mol) of monomethyltin trichloride dissolved in 200 ml of water. Solv the ladle was heated to 30°C and 218 g (1.0 mol) of 1-methyl-2-mercaptoethyl caprylate were added. 80 g (0.5 mol) of 50% aqueous sodium hydroxide was then added dropwise at 30-40°C and the mixture was stirred for one hour. Then 32.5 g (0.25 mol) of 60% aqueous sodium sulphide in 100 ml of water at 25-35°C were added dropwise, the mixture was stirred for one hour and the layers formed were separated. The organic layer was washed with 200 ml of water and distilled under reduced pressure, whereby 283 g of an almost colorless oil was obtained. n2^ 1.5256. The product essentially consists of bis(monomethyltin-bis(1-methyl-2-mercaptoethyl caprylate)) sulphide. ;EXAMPLE 4- 2 ;A 3-neck flask was added with 120 g (0.5 mol) of methyltin trichloride dissolved in 200 ml of water, 121 g (1.0 mol) of 2-mercaptoethyl acetate, after which 31 g (0.5 mol) were slowly added 28% aqueous ammonium hydroxide. The mixture was stirred for one hour at 30-35°c, after which 125 g (0.25 mol) of 20% aqueous ammonium disulphide were added during 60 minutes at the said temperature. The mixture was heated to 50°C, and the lower product layer was separated from the aqueous phase. The product was washed with 200 ml of water and dried at 100°C under reduced pressure. A 96% yield of a pale yellow oil with a refractive index at 25°C of 1.5697 was obtained. The product is essentially bis(monomethyltin-bis(2-mercaptoethyl acetate)) - disulphide. ;EKS EMPEL 43 ;A 3-necked flask was charged with 131 g (0.6 mol) of 2-mercaptoethyl caprylate, 61.5 g (0.3 mol) of isooctylthioglycolate, 400 ml of toluene, 200 ml of water and 216 g (0.9 mol ) monomethyltin trichloride. The solution was cooled to 10°C and 64 g (0.8 mol) of 50% aqueous sodium hydroxide at 10220°C was added. The reaction mixture was stirred for 15 minutes and 117 g (0.9 mol) of 60% Na 2 S in 150 ml of water was added over 30 minutes. The mixture was then stirred for 15 minutes and then 8.0 g (0.1 mol) of 50% aqueous NaOH was added and then stirred at 50°C. The organic layer was separated and distilled under vacuum at 100°C. The yield was 315 g of a viscous, yellow oil, and it was assumed that this was the following compound: ;n<2>5 1.5388. EXAMPLE 44 In a 3-necked flask was added 18}.5 g (0.5 mol) of methyl thiostannoic acid and 371 > 5 g.(0.5 mol) of methyl tin tris(2-mercaptoethyl caprylate). The mixture was stirred and heated under nitrogen for 1.5 hours at 120°C. The product which was a clear amber oil was obtained in a yield of 96%. It is assumed that the product has the following structure: ;<n>j<p><1,>534<8. EXAMPLE 45 120 g (0.5 mol) of methyltin trichloride dissolved in 200 ml of water was added to a 3-necked flask. The solution was heated to 30°C and 260 g (1.0 mol) of 6-mercaptohexyl caprylate was added. 80 g (1.0 mol) of 50% aqueous NaOH solution were then added dropwise at 30-40°C. The mixture was then stirred for one hour. A solution of 32.5 g (0.25 mol) of 60% aqueous sodium sulphide in 100 ml of water was then added at 25-35°C. After stirring for one hour at 35°C, the product layer was separated and washed with 200 ml of water. The product was then distilled at 100°C under vacuum, and a yield of 99% of a pale yellow oil was obtained. n2^ 1.5345. It is assumed that the oil is bis(methyltin-bis(6-mercaptohexylcaprylate)J sulphide. ;EXAMPLE 4-6 ;A 2 liter flask was added with 120 g (0.5 mol) of methyl tin trichloride in 200 ml of water. The solution was heated to 30° C and added 153 g (0.75 mol) of 2-mercaptoethyl caprylate and 19.5 g (0.25 mol) of mercaptoethanol and 4-00 ml of toluene. Then 84 g (1, 0 mol) of sodium bicarbonate dissolved in 25OO ml of water. The mixture was then stirred for 2 hours. Then a solution of 32»5 g (0.25 m°D 60 <fo of aqueous sodium sulphide in 100 ml of water was added dropwise at 35°C The reaction mixture was stirred for 2 hours, the organic layer was separated and distilled at 90°C under vacuum, and 204 g of a pale yellow oil was obtained. n^<5> 1.5292. It is assumed that the product essentially, (monomethyltin(2-mercaptoethylcaprylate)(2-mercaptoethanol)J (monomethyltin-bis(2-mercaptoethylcaprylate)) is sulfide. ;EXAMPLE 47 ;A 3-necked flask was charged with 122.5 g (°>5 mol) of butyl -chlorotin dihydroxide, 165 g (0.5 mol) 2-merc aptoethyl oleate and 75O ml of toluene. The mixture was boiled under reflux until 8.5 ml of water had been removed. The organic layer was distilled, and 260 g of a pale yellow oil with a refractive index of ;n^ p 1.5320 was obtained. It is assumed that the product is bistmonobutylmonochlorotin-(2-mercaptoethyloleate)oxide. EXAMPLE 48 In a 3-necked flask was added 181.5 g (0.5 mol) methyl-thiostannoic acid and 408 g (2.0 mol) 2-mercaptoethyl caprylate, and the mixture was stirred and heated at 90-110°C in 1.5 hours under slightly reduced pressure. The liquid was then cooled and filtered at 40°C. The product of 571 g of a pale yellow oil had a refractive index at 25°C of 1.5248. EXAMPLE 49 360 g (1.5 mol) of monomethyltin trichloride dissolved in 500 ml of water were added to a 3-necked flask. The solution was heated to 30°C and 817 g (4.0 mol) of 2-mercaptoethyl caprylate was added. 320 g (4.0 mol) of 50% aqueous sodium hydroxide was then added dropwise at 30-40°C, and the mixture was stirred for one hour at the said temperature. A solution of 32.5 g (0.25 mol) of 60 µl of sodium sulphide dissolved in 100 ml of water was then added. After stirring for one hour at the aforementioned temperature, the product layer was separated and washed with 400 ml of water. The product was then distilled to 100°C under vacuum, and 999 g of an almost colorless oil was obtained, ;n<2>5 is 1.5113- ;EXAMPLE 50 ;A 3-neck flask was added with 555 g (0.5 mol ) bis-(methyltin-bis(2-mercaptoethyl caprylate)) sulphide, 97 g (0.5 mol) dimethyltin oxide and 4-00 ml of toluene. The mixture was stirred and refluxed for 2 hours, and a clear solution was obtained. The solvent was removed under vacuum to give 650 g of a pale yellow oil. The reaction product contains [monomethyltin-bis(2-mercaptoethylcaprylate))Cmonomethyltinmono(2-mercaptoethylcaprylate)mono(2-mercaptoethyloxydimethyltincaprylate)) sulphide. n25 1.5289. ;EXAMPLE 51 ;A 3-necked flask was added with 180 g (0.75 mol) of monomethyltin trichloride dissolved in 300 ml of water and the whole was heated to 30°C and 3°6.5 g (1.5 mol) of 2-mercaptoethyl caprylate was added . 120 g (1.5 mol) of 50% aqueous NaOH solution were then added dropwise at temperatures from 30-40°C. The mixture was stirred for one hour. A solution of 16.3 g (0.125 mol) 60 µl of sodium sulphide dissolved in 75 ml of water at 30-4.0°C was then added. After stirring for one hour at the aforementioned temperature, the product layer was separated and washed with 250 ml of water. The product was distilled to 100°C under vacuum, and 430 g of a pale yellow oil was obtained. The reaction product contains two compounds with the following formulas: ;;The refractive index of the mixture is 1.5151 at 25°C. EXAMPLE 52 216 g (0.9 mol) methyltin trichloride, 22 g (0.1 mol) dimethyltin dichloride dissolved in 300 ml water were added to a 3-necked flask. The solution was heated to 30°C and 511 g (2.5 mol) of 2-mercaptoethyl caprylate were added. Then, 200 g (2.5 mol) of 50 µl of aqueous sodium hydroxide were added dropwise at 30-4°C. The mixture was stirred for one hour. A solution of 26 g (0.20 mol) of 60 µl of aqueous sodium sulphide dissolved in 75 ml of water at 30-40°C was then added. After stirring for one hour, the product layer was separated and washed with 250 ml of water. The product was then vacuum distilled to 100°C, and 631 g of a colorless oil was obtained. n<25> 1.5153. EXAMPLE 53 120 g (0.5 mol) of methyltin trichloride dissolved in 200 ml of water was added to a 3-necked flask. The solution was heated to 30°C and 360 g (1.0 mol) monothioglycerin dicaprylate ester was added. 80 g (1.0 mol) of 50% aqueous sodium hydroxide solution were then added dropwise at temperatures from 30-40°C. The mixture was stirred for one hour. A solution prepared by heating 32.5 g (0.25 mol) of 60% aqueous Na2S and 8.0 g (0.25 mol) of sulfur in 100 ml of water was then added. The solution was added dropwise at ^ 0-^. 0°0,. After stirring for one hour, the product layer was separated and washed with 200 ml of water. The product was then distilled to 100°C under vacuum, and a yield of 325 g of a yellow oil was obtained. n2^ 1.5143. The product is essentially bis-(monomethyltin-bis(thioglycerin dicaprylate)disulfide. EXAMPLE 54 110 g (0.5 mol) of dimethyltin dichloride dissolved in 200 ml of water was added to a 3-necked flask. The solution was heated to 30°C and 109 g (0.5 mol) of 2-mercaptoethyl pelargonate was added. 40 g (0.5 mol) of a 50% aqueous sodium hydroxide solution were then added dropwise at 30-40°C. The mixture was then stirred for one hour. A solution of 32.5 g (0>25 mol) of 60 µl of aqueous Na2S dissolved in 75 ml of water at 25-35°C was then added. After stirring for one hour at 35°C, the product layer was separated and washed with 200 ml of water. The product was distilled to 100°C under vacuum, and a yield of 95*5% of a pale yellow oil was obtained.

nlP 1»5319' The product is essentially bis(dimethyltin mono-(2-mercaptoethyl pelargonate) sulphide.

EXAMPLE 55

To a 2 liter flask was added 60 g (0.25 mol) of monomethyltin trichloride, 55 g (0.25 mol) of dimethyltin dichloride dissolved in 200 ml of water. The solution was heated to 30°C and 162 g (0.75 mol) of 2-mercaptoethyl pelargonate was added, then 60 g (0.75 mol) of 5% aqueous sodium hydroxide was slowly added. The mixture was stirred for one hour, and 32.5 g (0.25 m°D 60 f> of aqueous sodium sulphide dissolved in 75 ml of water was added. After stirring for one hour at 35 C, the layers were separated, the organic phase was washed with 200 ml of water and dried under vacuum to 100° C. A total of 229 g of a pale yellow oil n<2>^ 1.5296 was obtained. The product is a mixture of mono-methyldimethyltin-mono/di-2-mercaptoethyl pelargonate sulphide.

EXAMPLE 56

Bis(monomethyltin-bis(2-mercaptoethyl pelargonate)-sulphide was mixed with the product of Example 54 in a ratio of 2/1, n^<5> being 1.5301.

Products according to the present invention, i.e. mercaptoalkylalkanoates have an ability to react with greater efficiency than the corresponding alkylthioalkanoates, with the dialkyl tin oxide? and alkylstannoic acids. Under conditions where methyltin-tris(alkylmercaptoacetate or propionate) does not react at all with BugSnO or Me2Sn0, the corresponding methyltin-tris(2-mercaptoethylalkanoate) will react completely after a treatment for a couple of hours at 80-120° C. It is assumed that the products have the following formula:

In order to illustrate the beneficial effects that can be achieved with stabilized compositions according to the present invention, the following experiments were carried out. All stabilizers were judged on a basis of equal cost and unequal weight shares. This means that certain stabilizers were used in larger quantities due to their lower unit costs. The tables are also set up essentially on a similar tin basis. The composition of the PVC resins in tables I-TI is as follows:

Color scale: 10 (white) - 5 (light brown-orange) -

0(burnt)

(intensity, not hue)

Color scale: 10 (white) - 5 (light brown-orange) -

0(burnt)

Color scale: 10 (white) - 5 (light brown-orange) -

0(burnt

Color scale: 10 (white) - 5 (light brown-orange) - 0 (burnt)

(intensity, not hue)

Try:

20 bis(methyltin-bis(isooctylthioglycolate)] disulfide

21 bisfmonomethyltin bis(2-meFcaptoethyl oleate)) sulphide.

In a pipe expulsion test, compounds according to the present invention proved to be far better stabilizers than

commercially available tin stabilizers, and gave a white tube with excellent production rate. Both dynamic mill stability (DMS) and residual furnace stability tests were carried out on the products.

The products were the same as those used in Tables I to IV using Allied SR 414-3 as the vinyl chloride resin. The amounts of stabilizer are indicated in Tables V and VI. The amounts were chosen so that there was approximately the same amount of tin in each of the compositions. The sample numbers are the same as in tables I to IV and additional numbers are given under table V.

Color scale: 10 (white) - 5 (orange) _ O (burnt)

Color scale: 10 (white) - 5 (orange) - O (burnt)

#22 - faint gray pollution.

Mixtures of monoalkyltin compounds and dialkyltin compounds according to the present invention prove to be more effective than individual components, and this applies whether they are prepared together from chlorides or only mixed afterwards, and this is evident from Table VII.

Color scale: 10 (white) - 5 (light brown-orange) - O (burnt)

Color scale: 10 (white) - 5 (light brown-orange) - 0 (burnt)

Claims (6)

1. Monoorganotin or diorganotin mercaptoalkyl ester of a carboxylic acid or mercaptohydroxyalkyl ester of a carboxylic acid mono- or polysulfide for use as a heat stabilizer in chlorine-containing polymers, characterized in that the organotin compound has the general formula: where x is 1, 2 or 3; y is 1-6; z is 0-6; , R 2 , R 8 , R 4 , R 5 and R 8 are C 1-6 alkyl, phenyl, R 8 and R 8 are hydrogen or methyl; R 7 and R 15 are hydrogen; R 1 Q is C 7 -C 17 alkyl, benzyl or C 17 -alkenyl; while Rg is methylene. 2. Organotin compound according to claim 1, characterized in that it consists of bis[monomethyltin-bis(2-mercaptoethyl oleate)] sulphide. 3. Organotin compound according to claim 1, characterized in that it consists of bis[methyltin di-(2-mercaptoethyl tallate)] sulphide. 4. Organotin compound according to claim 1, characterized in that it consists of bis[methyltin di-(2-mercaptoethyl pelargonate)] sulphide. 5. Organotin compound according to claim 1, characterized in that it consists of bis[monomethyltin-bis(2-mercaptoethylphenylacetate)]sulphide. in 6. Organotin compound according to claim 1, character- terized in that it consists of bis[dimethyltin-mono-(2-mercaptoethyl pelargonate)]sulphide.