JPS6338064B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a stabilizer for polyvinyl chloride comprising a novel organotin compound. Polymers such as polyvinyl chloride generally have poor thermal stability, and therefore various stabilizers have been considered. Among them, organic tin compounds such as butyltin are known. However, these conventional stabilizers have not been satisfactory in imparting thermal stability to the above polymers. As a result of intensive studies to solve the above problems, the present inventors discovered that a novel organotin compound represented by the following formula is useful for improving the thermal stability of polyvinyl chloride, leading to the present invention. . That is, the present invention provides formula (R) ₂ SnX ₂ [wherein R is

【formula】

【formula】 Or

[Formula] (In the formula, R ₁ and R ₂ are the formula

[Formula] (where R ₅ represents alkoxy having 1 to 18 carbon atoms), R ₃ and R ₄ are both hydrogen, and X is

[Formula] (n=1 or 2), -S-alkyl,

[Formula] and Beauty

The present invention relates to a stabilizer for polyvinyl chloride comprising an organotin compound having the following formula: [Representing an organic residue selected from the group consisting of] The organotin compound used in the stabilizer of the present invention can be produced using an organotin halide as a starting material. The organotin halides can be prepared by converting tin chloride to tetraalkyltin, which is then converted to alkyltin halides, using Grignard, aluminum alkyl, or Wurtz routes, or by reacting tin metal directly with alkyl halides. to form alkyltin halides (e.g. as described in Dutch Patent Specification No.
144283), etc.), but the applicant's application (Patent No. 113831)
It is advantageous to carry out the following procedure as described in Publication No. Metallic tin and hydrogen halide and the following formula (However, R ₁ , R ₂ , R ₃ , and R ₄ represent hydrogen or hydrocarbon groups, and at least one of R ₁ and R ₂ is an oxygen-containing group having a carbonyl group adjacent to an olefin double bond.) ) is reacted with olefin to form the following structural formula: Forms an organotin dihalide with . The reaction between metallic tin, hydrogen halides, and olefins activated by one or more carbonyl groups gives high yields calculated from tin without the use of catalysts at room temperature and pressure. . As hydrogen halide, it is preferred to use hydrogen chloride, which is relatively inexpensive. The activated carbonyl group in the olefin can, for example, form part of an acid group, ester group, aldehyde group, or keto group. Examples of suitable olefins include: Acrylic acid, acryloyl chloride, methyl acrylate, 1,1-bis(carboxyethyl)propylene, methyl crotonate, methyl vinyl ketone,
Methyl 2-cyclohexyl acrylate, mesityl oxide, cinnamic acid, methylstyryl ketone, cinnamic acid methyl ester. Therefore, in the above method, at least one of R ₁ and R ₂ is (wherein R ₅ represents alkoxy having 1 to 18 carbon atoms), which is an oxygen-containing group, is used. Optionally, the reaction can be carried out in a solvent. Examples of suitable solvents include ethers, alcohols, esters, chlorinated or non-chlorinated hydrocarbons. It is also possible to use an excess of olefin as a solvent. Tin metal can be used in any form. In principle, it is preferable to use powdered tin. This is because the reaction rate increases as a result of the large available tin surface. However, commercially available granular tin can also be used directly. In the latter case, a moderate increase in reaction temperature is desirable to increase the reaction rate. The above methods typically produce functionally substituted organotin dihalides having the general structure (R) ₂ SnHal ₂ . However, R is the group defined above. represents. This compound forms an exceptionally good raw material for the production of novel organotin stabilizers for polyvinyl chloride by known techniques. In the stabilizers of the present invention, the halogen atoms are replaced with conventional organic residues such as acids, thioesters, thioalkyl groups. It is known from the alkyltin stabilizer art that mixtures of dialkyltin and monoalkyltin stabilizers have a synergistic effect. From previous studies conducted by the applicant, tin dihalides, hydrogen halides, and carbonyl-activated olefins react with each other to form organotin trihalides having the general structural formula RSnHal ₃ . It seems that it does. It has been found that the above process can be controlled such that a portion of the metal tin is first converted to tin dihalide and then reacted to form organotin trihalide. In this way, metal tin can be directly converted into (R) ₂ SnHal _2.
It is now possible to form a mixture of RSnHal ₃ and then convert this mixture directly into a stabilizer mixture with the desired synergistic effect. As is clear from the following reference example, the amount of trihalide in the organotin halide is, for example, 0.
It can vary within wide limits from ~95% by weight. When trying to obtain a mixture, the amount used is usually about 5 to 60
Within the range of % by weight. In order for any amount of trihalide to form simultaneously in the reaction product, a competitive reaction between tin and hydrogen halide, on the one hand, and between said substance and the activated olefin, on the other hand, must occur in favor of the former reaction. It is necessary to be influenced. The formation can then be particularly facilitated by varying the proportions of the reactants, the order and/or rate of addition of the reactants, the available tin surface, and, to a lesser extent, the temperature. Thus, for example, use of excess olefin, slow addition of hydrogen halide, and reduction of available tin surface tend to result in excessive formation of dihalide (R) ₂ SnHal ₂ . If the reaction conditions are reversed to the above, trihalides are produced.
Increases production of RSnHal ₃ . If desired, the organotin dihalide R ₂ SnHal ₂ mixed with R ₂ SnHal ₃ can be reacted in a conventional manner with an acid or a mercaptan to form the general formula (R) ₂ SnX ₂ which can be a mixture with RSnX ₃ . It also produces an excellent stabilizer. The organotin salt having acid residues X is preferably formed by reaction with partial esters of alkylthiocarboxylic esters, alkylthiols, monocarboxylic acids, polycarboxylic acids. As particular examples of good stabilizers derived from the organotin dihalides mentioned above, mention may be made of the following: Thiocarboxylic acid alkyl ester (CH ₃ OCOCH ₂ CH ₂ ) ₂ Sn [S(CH ₂ )
nCOOC ₈ H ₁₇ 〕 ₂ (BuOCOCH ₂ CH ₂ ) ₂ Sn〔S(CH ₂ )
nCOOC ₈ H ₁₇ 〕 ₂ (C ₁₈ H ₃₇ OCOCH ₂ CH ₂ )2Sn〔S(CH ₂ )
nCOOC ₈ H ₁₇ 〕 ₂ (BuOCOCH ₂ CH ₂ ) ₂ Sn〔S(CH ₂ )nCOOBu〕 ₂ However, n = 1 (thioacetic acid ester) or 2
(thiopropionic acid ester). Alkyl mercaptide (CH ₃ OCOCH ₂ CH ₂ ) ₂ Sn (SC ₁₂ H ₂₅ ) ₂ (BuOCOCH ₂ CH ₂ ) ₂ Sn (SC ₁₈ H ₃₇ ) ₂ (C ₁₂ H ₂₅ OCOCH ₂ CH ₂ ) ₂ Sn (SC ₁₂ H ₂₅ ) ₂ carboxylate (CH ₃ OCOCH ₂ CH ₂ ) ₂ Sn (OCOC ₁₁ H ₂₃ ) ₂ (BuOCOCH ₂ CH ₂ ) ₂ Sn (OCOC ₁₇ H ₂₅ ) ₂ Partial ester (CH ₃ OCOCH ₂ CH ₂ ) ₂ Sn (OCOCH=
CHCOOBu) ₂ (BuOCOCH ₂ CH ₂ ) ₂ Sn (OCOCH=
CHCOOCH ₃ ) _2In the above exemplary compounds and hereinafter in this specification, "-OCO-" in the chemical formula is

[Formula] shall be expressed as follows. Organotin stabilizers according to the present invention generally yield better polyvinyl chloride than traditional butyltin stabilizers. It has been found that in the case of sulfur-containing stabilizers, the odor is considerably improved. Particularly in the food field (packaging films, etc.), the toxicity of stabilizers is of great importance. In this regard, the various stabilizers according to the invention have been found to be significantly more preferable than traditional butyltin stabilizers. Therefore, the LD ₅₀ value of the traditional stabilizer (C ₄ H ₉ ) ₂ Sn (SCH ₂ COOC ₈ H ₁₇ ) ₂ (i.e., the dose that kills 50% of experimental animals) for rats is approximately 500 mg/Kg of body weight. . However, for the compound (CH ₃ OCOCH ₂ CH ₂ ) ₂ Sn (SCH ₂ COOC ₈ H ₁₇ ) ₂ this species is on the order of 12000 mg/Kg. The following examples are examples of the present invention. Reference Examples 1 to 12 describe the preparation of organotin dihalides, which are the raw materials for the organotin compounds used in the present invention, with or without the simultaneous formation of trihalides. . Reference Examples 13 to 16 relate to the production of organotin compounds used in the stabilizer of the present invention from these halides. Example 1 describes a comparative study of stabilizers from organotin compounds of the invention added to polyvinyl chloride. Reference Example 1 A 500 ml three-necked flask placed in a cold bath and equipped with a stirrer, a thermometer, a condenser, and a gas inlet tube was charged with 60 g of powdered tin, 87.4 g of methyl acrylate, and 140 ml of diethyl ether as a solvent. Dry hydrogen chloride gas with stirring at 20°C for about 3 hours.
87 g were introduced into the above mixture. Then, the ether was distilled off and the residue was extracted with 300 ml of hot chloroform. Traces of tin chloride ()
Along with this, about 0.5 g of unreacted tin remained. After removing chloroform from the chloroform extract at 100° C. and 4 mmHg, 177.2 g of a whitish solid remained. Analysis (Nuclear Magnetic Resonance Spectroscopy) _reveals that this material is a mixture of organotin dihalides and _{trihalides ,} namely _Cl2Sn ( _CH2CH2COOCH3 ) ₂ and 27% by weight _{of Cl3SnCH2CH2COOCH} It turned out to be a mixture of ₃ . The yield was quantitative based on tin conversion. After washing the mixture with diethyl ether in which the above trichloride is well soluble, a white crystalline material remains and is subjected to repeated analysis (infrared, nuclear magnetic resonance spectroscopy, and elemental analysis).
Pure Cl ₂ Sn with melting point 132℃ at
It was found that (CH ₂ CH ₂ COOCH ₃ ) ₂ . Reference example 2 By the method used in reference example 1, 60g of powdered tin
and methyl acrylate 95.7g and diethyl ether 110g
ml was placed in a flask. 20℃ for about 14 hours
42 g of dry hydrogen chloride gas was passed through the above mixture. As in Reference Example 1, the solvent was removed and the residue was extracted, after which 167.2 g of white solid material with 3.7 g of unreacted tin remaining was obtained from the extract. This substance Cl ₂ Sn
_{( CH2CH2COOCH3} ) ₂ and 3.5% by _weight
It was found to be a mixture of Cl ₃ SnCH ₂ CH ₂ COOCH ₃ . Calculated from the amount of tin used, the yield was 98%. Reference Example 3 According to the method of Reference Example 1, 60 g of tin powder, 37.1 g of methyl acrylate, and 140 ml of hexane were placed in a flask, and 46 g of dry hydrogen chloride gas was introduced over a period of 121/2 hours. Filter the reaction mixture with hexane
After washing with 100 ml and extracting with hot chloroform, 1.5 g of unreacted tin remained and 173 g of solid material was obtained from the extract. Analysis shows that this substance is Cl ₂ Sn (CH ₂ CH ₂ COOCH ₃ ) _2.
It was found to be a mixture of 15.9% by weight Cl ₃ SnCH ₂ CH ₂ COOCH ₃ . Calculated from converted tin,
The yield was 99%. Reference Example 4 50 g of tin powder and 95.7 g of methyl acrylate were introduced into the flask of Reference Example 1. 115 g of hydrochloric acid (35.4%) was added with stirring over 45 minutes, after which stirring was continued for 4 hours. The reaction mixture was then separated, washed with water, and extracted with chloroform. 14.9 g of unreacted tin remained, and the extract yielded 103.5 g of solid material, which was analyzed to be pure _Cl2Sn .
It was found that (CH ₂ CH ₂ COOCH ₃ ) ₂ . The remainder was contained in the wash water as tin chloride. Reference Example 5 According to the method of Reference Example 1, 60 g of tin powder and 174.2 g of methyl acrylate (which also acts as a solvent) were placed in a flask. Dry hydrogen chloride gas for 15 hours
Introduced 40g. The reaction mixture was filtered and washed with 20 g of methyl acrylate. Chloroform extraction left 5.0 g of unreacted tin, and the extract yielded a crystalline product of pure Cl ₂ Sn (CH ₂ CH ₂ COOCH ₃ ) ₂ with a yield of 84.6% calculated as converted tin.
141.2g was obtained. The liquid still contains 17.3g of the above product.
The final yield was 95%. Reference Example 6 Using the procedure used in Reference Example 1, 60g of powdered tin
and methyl acrylate 95.7g and diethyl ether 140g
ml was placed in a flask. Then 110 g of dry hydrogen bromide gas was introduced over a period of 101/2 hours. After removing the solvent, heat the residue with 300 ml of chloroform.
9.5g of terminally reacted tin remained. Evaporation of the extract gave 196.0 g of a solid material, which was composed of Br ₂ Sn(CH ₂ CH ₂ COOCH ₃ ) ₂ with a melting point of 137°C.
A mixture of Br ₃ SnCH ₂ CH ₂ COOCH ₃ and 19.7 wt. The yield was quantitative as calculated from the tin conversion. Reference Example 7 In the flask of Reference Example 1, 60 g of tin powder, 99.2 g of mesityl oxide, and 140 ml of diethyl ether were placed. Then 70 g of dry hydrogen chloride gas was introduced over a period of 101/2 hours. After washing with 150 ml of filtered, ice-cold ether, the residue was extracted with 300 ml of chloroform. No tin remained and the extract yielded a pale, colored crystalline material 84.69, which was pure Cl ₂ Sn(C(CH ₃ ) ₂ CH ₂ COCH ₃ ) ₂ with a melting point of 158°C. The yield, calculated from the converted tin, was 43%. After evaporation, 89.5 g of a dark and colored product were obtained from the ether solution, which contained approximately 40% by weight of Cl ₂ Sn(C(CH ₃ ) ₂ CH ₂ COCH ₃ ) ₂ and 40% by weight of
It was found that it contained Cl ₃ SnC (CH ₃ ) ₂ CH ₂ COCH ₃ . Therefore, the final total yield of organotin compounds is approximately
It was 80%. Reference Example 8 In the flask of Reference Example 1, 60 g of tin powder, 78.0 g of methyl vinyl ketone, and 140 ml of diethyl ether were placed. Then 54 g of dry hydrogen chloride gas for 14 hours.
introduced. The reaction mixture was filtered to remove traces of unreacted tin (approximately 0.1 g) and then heated to 4 mmHg at 100°C.
evaporation at 50° C., leaving 162.4 g of a dark, colored solid material. Analysis reveals that this material contains approximately 40% _Cl2Sn by weight.
( _CH2CH2COCH3 ) ₂ and ₄₀ % by _weight
It was found that it contained Cl ₃ SnCH ₂ CH ₂ COCH ₃ . The total yield of organotin compound, calculated from the converted tin, was about 80%. Reference Example 9 The flask of Reference Example 1 was charged with 60 g of tin powder, 91.5 g of acryloyl chloride, and 140 ml of diethyl ether. Over a period of 191/2 hours, 60 g of dry hydrogen chloride gas were introduced. Unreacted tin is removed from the reaction mixture by
24g was removed and then evaporated. After extracting the residue with 300 ml of hot chloroform, the extract was concentrated and 103 g of a colored solid material was obtained. Analysis shows that this material contains mainly Cl ₂ Sn (CH ₂ CH 2 COCl) ₂ as well as some Cl 2 Sn (CH 2 CH ₂ COCl) 2
It was found that it contained Cl ₃ SnCH ₂ CH ₂ COCl. Due to the presence of organic matter, an accurate determination of the yield was not possible. Reference Example 10 The flask of Reference Example 1 was charged with 60 g of tin powder, 129.6 g of n-butyl acrylate, and 140 ml of diethyl ether. 54g dry hydrogen chloride gas over 20 hours
introduced. 0.2g of unreacted tin after filtering the reaction mixture
is removed and the solution is then concentrated to produce a clear colorless liquid.
224g was obtained, which was analyzed in a small amount.
Mainly Cl ₂ Sn with Cl ₃ SnCH ₂ CHCOOC ₄ H ₉
It was found that it consists of (CH ₂ CH ₂ COOC ₄ H ₉ ) ₂ .
The overall yield was approximately 97% calculated from the tin conversion. In this case, since the reaction product is a liquid, the method used in this reference example is well suited for continuous operation. Reference Example 11 The flask of Reference Example 1 was charged with 60 g of tin powder, 101.2 g of methyl methacrylate, and 140 ml of diethyl ether. followed by dry hydrogen chloride gas for 22 hours.
Introduced 44g. The reaction mixture was evaporated and the residue was extracted with 300ml of hot chloroform. 33.3 g of unreacted tin thus remained, and the extract finally yielded 67.3 g of a crystalline material, which by analysis had a melting point of 111 °C.
It was found that it consisted of Cl ₂ Sn(CH ₂ CH(CH ₃ )COOCH ₃ ) ₂ with 57.5% by weight of Cl ₃ SnCH(CH ₃ )COOCH ₃ . The overall yield was 84%, calculated from the tin conversion. Reference Example 12 Attach a heating jacket to the flask of Reference Example 1,
60g of granular tin and 129.6g of n-butyl acrylate were added. Then, after heating the contents of the flask to 120℃,
78 g of dry hydrogen chloride gas was introduced over a period of 12 hours. The reaction mixture was filtered to separate unreacted tin (9.8 g), and the liquid was evaporated to remove residual butyl acrylate and by-product hydrochlorinated acrylic ester. 179.8 g of a clear, virtually colorless liquid remained, which analysis showed to consist primarily of Cl ₂ Sn(CH ₂ CH ₂ COOBu) ₂ . The yield was 95% calculated from the converted tin. The product was slightly contaminated with polybutyl acrylate. Reference example 13 In a 600ml beaker equipped with a stirrer, thermometer, and heating plate, Cl ₂ Sn (CH ₂ CH ₂ COOCH ₃ ) ₂ (Reference example 1)
54.6 g (isolated as above), 64.3 g of isooctyl thioglycolate, and 200 ml of tetrahydrofuran as a solvent were added. 26.6 g of anhydrous sodium bicarbonate was added to the mixture with stirring and then heated at 50-60° C. for 2 hours. The sodium chloride produced was separated and the liquid was concentrated to obtain 104.8 g of a colorless liquid. _The hot liquid _was filtered again _and identified by analysis as ( _{CH3OCOCH2CH2 ) 2Sn} ( _SCH2COOC8H17 ) ₂ . IR (cm ^-1 ): 2950 (s), 2920 (sh) (s), 2870 (w), 1730
(s) 1460 (w), 1440 (w), 1380 (w), 1360 (m), 1290 (m), 1210 (m), 1180 (sh) (m), 1140
(m) 1035 (w), 985 (w), 920 (w), 870 (w), 830
(w), 750 (w), s: strong m: medium w: weak sh: shoulder Elemental analysis: Actual value (calculated value) % Sn16.89 (16.97), % S9.21 (9.17) % C 47.91 (48.07) ), % H7.52 (7.49) % O 18.03 (18.30) Through the above synthesis, it is also possible to prepare a mixture of corresponding tin thioglycolate compounds from a mixture of organotin dihalides and trihalides. It was hot. Reference example 14 Add lauric acid to the three-necked flask according to reference example 1.
64.5g and 12g of sodium hydroxide dissolved in 250ml of water
I prepared it. Raise the temperature to 70-80℃, then
54.6 g of Cl ₂ Sn(CH ₂ CH ₂ COOCH ₃ ) ₂ was added and kept at the above temperature for 1 hour. Then, 150 ml of toluene was added and stirring was continued for an additional 5 minutes. The produced toluene layer was separated and concentrated to obtain 102 g of a pale yellow liquid containing (CH ₃ OCOCH ₂ CH ₂ ) ₂ Sn(OOCC ₁₁ H ₂₃ ) ₂ . By the same operation as above, a mixture of organotin dihalides and trihalides could be converted into the corresponding tin laurate compound mixture. Reference example 15 Cl ₂ Sn in a 600ml beaker
( _CH2CH2COOCH3 ) _{2 72.7g and} laurylthiol
80.8g and 250ml of tetrahydrofuran as a solvent were charged. After stirring and adding 42.4 g of anhydrous sodium carbonate, the mixture was heated at 60° C. for 1 hour. Then, remove the sodium chloride and concentrate the liquid to a colorless liquid.
137 g were obtained, which by analysis was found to consist of (CH ₃ OCOCH ₂ CH ₂ ) ₂ Sn(S—C ₁₂ H ₂₅ ) ₂ . IR (cm ^-1 ): 2595 (sh) (m), 2592 (s), 2585 (s), 1725
(m), 1460 (w), 1440 (m), 1375 (sh) (m), 1360
(m), 1260 (w), 1210 (m), 1180 (w), 1140 (w), 1035 (w), 970 (w), 915 (w), 745 (w), 720
(w), Elemental analysis: Actual value (calculated value) % Sn 16.91 (17.06), % S 9.07 (9.22) % C 55.41 (55.25), % H 9.06 (9.27), % O 9.38 (9.20) By the same method, A mixture of di- and trithiolauryltin compounds could be obtained. Reference example 16 Cl ₂ Sn in a 60ml beaker
72.7 g of (CH ₂ CH ₂ COOCH ₃ ) ₂ , 68.8 g of monobutyl maleate, and 250 ml of tetrahydrofuran as a solvent were charged. After adding 33.6 g of anhydrous sodium bicarbonate,
The temperature was kept at 60°C for 1 hour. Separate the sodium chloride and concentrate the solution (CH ₃ OCOCH ₂ CH ₂ ) ₂ Sn
124 g of a colorless liquid containing (OCOCH=CHCOOBu) ₂ was obtained. IR (cm ^-1 ): 2960 (m), 2920 (sh) (m), 2875 (w), 1730
(s), 1690 (sh) (s), 1680 (s), 1580 (m), 1440 (sh) (m), 1420 (m), 1360 (m), 1265
(m), 1220 (s), 1170 (s), 1060 (w), 1030 (w), 1020 (w), 920 (w), 885 (w), 845 (w), 820
(w), 775 (w). Elemental analysis: Actual values (calculated values) % Sn 18.74 (18.69) % C 45.23, % H 5.49 (5.71), % O 30.37 (30.22) Corresponding organotin dihalides and trihalides were prepared using the same method as di- and trimalein. It was possible to form a mixture of acid salt tin compounds. Example 1 The stabilizing effect of the organotin compound having the general structural formula (CH ₃ OCOCH ₂ CH ₂ ) ₂ SnX ₂ obtained in Reference Examples 13 to 16 was tested with polyvinyl chloride, and the known dibutyl stabilizer (C _4H9 ) compared _{with 2SnX2 .} In each case, 2% by weight of stabilizer, calculated from the (plasticized) polyvinyl chloride, was added and the heat resistance was determined on the basis of the color change over time at 185°C. A polyvinyl chloride bottle containing 1% by weight of the stabilizer mixture of Reference Example 13 containing 10% by weight of the corresponding RSnX ₃ compound, and 1% by weight of RSnX ₃ alone.
Tests were also conducted on the above bottles containing . The results are summarized in the table below.

[Table] Example 2 Same as Example 1,
Polyvinyl chloride stability tests were conducted on the compounds represented by (C ₄ H ₉ OCOCH ₂ CH ₂ ) ₂ SnX ₂ and (C ₁₈ H ₃₇ OCOCH ₂ CH ₂ ) ₂ SnX ₂ . The results are shown in Table 2.

TABLE It can be seen from the table that the stabilizer of the present invention provides improved stability. This is evidenced by a considerably improved "initial color", ie little or no color change during the initial heating period.

[Brief explanation of the drawing]

Figure 1 shows the chemical formula This is the infrared absorption spectrum of the compound represented by (Reference Example 13). Figure 2 shows the chemical formula This is an infrared absorption spectrum of the compound represented by (Reference Example 15). Figure 3 shows the chemical formula This is an infrared absorption spectrum of the compound represented by (Reference Example 16).

Claims (1)

_[ Claims] ₁ Formula ₍ R) ₂ S _o R ₅ represents an oxygen-containing group (representing alkoxy having 1 to 18 carbon atoms), R ₃ and R ₄ are both hydrogen, and X is [Formula] (n = 1 or 2), - S-alkyl, representing an organic residue selected from the group consisting of [Formula] and [Formula]] A stabilizer for polyvinyl chloride comprising an organic tin compound having the following. 2 Formula RSnX ₃ [However, R is [Formula] [Formula] or [Formula] (wherein R ₁ and R ₂ are the formula [Formula] (however, R ₅ represents alkoxy having 1 to 18 carbon atoms) is an _{oxygen -} containing group having The stabilizer for polyvinyl chloride according to claim 1, further comprising an organotin compound having an organic residue selected from the group .