JPS6320836B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing an organic tin mercapto stabilizer for halogen-containing resins that has little odor. Halogen-containing resins are prone to thermal deterioration mainly due to dehydrohalogenation reactions during hot molding.
As a result, products processed from such resins suffer from thermal discoloration or a decrease in mechanical properties. To improve these defects, metal stabilizers such as lead stearate, cadmium stearate, calcium stearate, barium stearate, zinc stearate, etc.; tin stabilizers such as alkyltin compounds are generally used. A method of adding . Among these stabilizers, especially organic tin mercaptocarboxylic acid ester salts such as dialkyltin bis(isooctylthioglycolate), dialkyltinbis(isooctylthioglycolate), and monoalkyltintris(isooctylthioglycolate) Stabilizers are widely used because they have excellent thermal stability and transparency. Such stabilizers are produced by a method in which a thioglycolic acid ester and an alkyl tin oxide are reacted in the presence of a solvent or in the absence of a solvent, and the resulting water is removed by vacuum treatment. However, such organic tin mercaptocarboxylic acid ester salts usually contain trace amounts of impurities in the thioglycolic acid ester that is the raw material, so they are produced as a side reaction product after synthesis.

【formula】

Alkyltin mercapto compounds such as [Formula], such as alkyltin sulfides or alkyltin mercaptocarboxylate salts, are difficult to handle, and improvements are desired. As a result of various studies on organic tin mercaptocarboxylic acid ester salts with low mercapto odor, the present inventor found that the wavelength in the infrared absorption spectrum
Absorbance ratio of 1560cm ^-1 and 1740cm ^-1 (1560cm ^-1 /1740
The inventors have focused on the fact that alkyltin mercapto compounds with a cm ^-1 ) of 0.2 or less have extremely low odor, and have found a method for producing the compounds, resulting in the present invention. That is, the present invention provides HS( _CH2 )nCOOR (wherein R is an alkyl group, alkenyl group, or alkoxyalkyl group having 6 to 18 carbon atoms, and n is an integer of 1 or 2), when the compound is After removing low-boiling point compounds by heat treatment at a reduced pressure that does not cause distillation, or by introducing nitrogen gas so that the compounds do not flow out,

【formula】

[Formula] and

[Formula] (where R' is an alkyl group having 1 to 8 carbon atoms) is added and reacted, and the by-produced water is heated to 100 mm at 60°C or less.
Provided is a method for producing an organic tin mercaptocarboxylic acid ester salt stabilizer for halogen-containing resins, which is characterized in that it is removed under conditions of Hg or less. The HS(CH ₂ )nCOOR used in the present invention usually contains up to about 2% by weight of impurities generated during the production or storage of the compound. Of course, such compounds may contain more than 2% by weight of impurities. Specific compounds of HS(CH ₂ )nCOOR include:
Thioglycolic acid isooctyl ester, thioglycolic acid 2-ethylhexyl ester, thioglycolic acid isodecyl ester, thioglycolic acid lauryl ester, thioglycolic acid tridecyl ester, thioglycolic acid cetyl ester, thioglycolic acid stearyl ester, thioglycolic acid cyclohexyl ester , β-mercaptopropionate isooctyl ester, β-mercaptopropionate 2-ethylhexyl, β-mercaptopropionate tridecyl ester, β-mercaptopropionate cetyl ester, β-mercaptopropionate stearyl ester, β-mercaptopropionate cyclohexyl ester Examples include esters, and a part of HS(CH ₂ ) nCOOR is converted into maleic anhydride, monoalkyl maleate (C ₁ to _{C 18} ) ester, aliphatic monocarboxylic acid having 6 to 18 carbon atoms, and aromatic monocarboxylic acid. may be used in combination to the extent that heat resistance and transparency are not impaired. The above used in the present invention

Examples of the formula include dimethyltin oxide, di-n-butyltin oxide, diisobutyltin oxide, di-n-octyltin oxide, and diisooctyltin oxide. or,

[Formula] and

[Formula] is monobutyltin oxide, monobutyltin hydroxide,
Examples include monooctyltin oxide and monooctyltin hydroxide. The means of removing low boiling point compounds from impure HS(CH ₂ ) nCOOR of the present invention is HS(CH ₂ )
Treatment is carried out at a reduced pressure such as 200 mmHg or less, preferably 100 mmHg or less, and at a temperature of 100°C or less, preferably 80°C or less, so that nCOOR does not distill out, or the treatment is carried out at a temperature of 100°C or less, preferably 80°C or less, or at a temperature of 100°C or less to prevent HS(CH ₂ )nCOOR from flowing out.
This is carried out by introducing nitrogen gas at a temperature of 80° C. or lower, preferably 80° C. or lower. In such processing,
HS(CH ₂ )nCOOR when carried out at temperatures exceeding 100℃
This is undesirable because the decomposition of the odor increases the amount of odor-causing components. The processing time varies depending on the conditions, but generally about 120 minutes is appropriate. The treated HS( _CH2 )nCOOR is then cooled below 40°C,

【formula】

[Formula] and

Reacts with at least one selected from [Formula] and usually (symbols in the formula are as above). At this time, water is produced as a by-product, but it is preferable to remove this water at the lowest possible temperature and under reduced pressure, that is, below 60° C. and below 100 mmHg. In particular, by-products (water) are removed under the conditions of a vacuum starting temperature of 30 to 60℃ and a vacuum degree of 100 mmHg or less, and then the maximum temperature under vacuum is reduced to 100 mmHg or less.
It is more preferable to keep the temperature at ℃. If by-products are not removed promptly, HS(CH ₂ )nCOOR will be hydrolyzed in water, thereby converting Sn-S(CH ₂ )
The resulting compound contains a strong-smelling reaction product of nCOOSn, and the resulting compound has an absorbance ratio (1560 cm ^-1 /
1740cm ^-1 ) is 0.2 or more. Therefore, the obtained alkyltin mercapto compound has a small absorbance at 1560 cm ^-1 observed in the infrared absorption spectrum of alkyltin sulfide and alkyltin mercaptocarboxylate, which emit a strong odor. Absorbance ratio of 1740 cm ^-1 observed in mercapto compounds (1560 cm
^-1 /1740cm ^-1 ) is less than 0.2. Such a compound has an absorbance ratio of 1560 cm ^-1 /1740 cm ^-1
More preferably, it is 0.15 or less. The organic tin mercaptocarboxylic acid ester salt used in the present invention is usually used in an amount of 0.1 to 5 parts by weight per 100 parts by weight of the halogen-containing resin. Examples of such halogen-containing resins include polyvinyl chloride, polyvinylidene chloride, chlorinated polyethylene, chlorinated polypropylene, chlorinated rubber, polyvinyl bromide, polyvinyl fluoride, vinyl chloride-vinyl acetate copolymer, and vinyl chloride-butadiene copolymer. Polymer, vinyl chloride-maleic ester copolymer, vinyl chloride-acrylic ester copolymer,
Examples include vinyl chloride-methacrylic acid ester copolymer and vinyl chloride-styrene-acrylonitrile copolymer. The stabilizer of the present invention may also include other stabilizers, such as calcium stearate, barium stearate, dialkyl tin malate polymers, dialkyl tin thioglycolate polymers, dialkyl tin bis(monoalkyl maleates), epoxidized soybean oil, organic substituents, etc. A phosphoric acid ester and an antioxidant can be used in combination. Next, the present invention will be explained in more detail with reference to Examples. Example 1 1-4 equipped with stirrer, thermometer and cooling tube
408 g (2 moles) of thioglycolic acid isooctyl ester with a purity of 99.0% was placed in a neck flask.
After stirring, the pressure was reduced to 15-25 mmHg.
After that, the temperature was raised to 70℃ under the above-mentioned reduced pressure, and 15 to 25 mm
The mixture was kept at Hg x 60-70°C for 2 hours to remove compounds with low boiling points. After that, the pressure was returned to normal, and after cooling to below 40℃, 361g (1 mol) of dioctyltin oxide was added.
The temperature was raised to 50°C and pressure reduction was started. After most of the by-products distilled out at 50℃×15mmHg, 10~
The temperature was raised to 98°C while maintaining the condition of 20 mmHg. 95~
After no by-products were distilled out under the conditions of 100°C x 10 to 20 mmHg, the pressure was returned to normal pressure, cooled to 70°C, and filtered. Dioctyltinbis(isooctylthioglycolate) was obtained, and its infrared absorption spectrum was measured using an infrared spectrophotometer. The results are shown in Figure 1.
In addition, the absorbance ratio of wavelengths 1560 cm ^-1 and 1740 cm ^-1 (1560 cm
^-1 /1740cm ^-1 ) was 0.09. This organic tin compound had extremely little mercapto odor. Example: In a 14-necked flask equipped with a stirrer, thermometer, and condenser, 99.0% pure thioglycolic acid 2-
412 g (2.01 mol) of ethylhexyl was charged and stirred. Next, the temperature was raised to 70° C. while blowing N ₂ gas, and low-boiling substances were removed by blowing N ₂ gas at 60 to 70° C. for 2 hours. Thereafter, the mixture was cooled to 40° C., and dioctyltin bis(2-ethylhexylthioglycolate) was obtained in the same manner as in Example 1. Figure 2 shows the infrared absorption spectrum of the obtained tin compound measured with an infrared spectrophotometer. From Figure 2, the absorbance ratio (1560 cm ^-1 /1740 cm ^-1 ) was 0.11. This compound had extremely little mercapto odor. Comparative Example: In a second four-necked flask equipped with a stirrer, thermometer, and condenser, 200 g of triol and 412 g (2.01 mol) of isooctyl thioglycolate, the same as in Example 1, were added.
After preparing and stirring, add dioctyltin oxide.
361 g (1 mole) was added, the temperature was raised to 90°C, and the distilled water was removed using a decanter, and the toluene distilled out at this time was returned to the flask. After no more water was distilled out, the temperature was raised to 130°C to remove most of the toluol. After almost all of the toluol was gone, it was cooled to below 100°C, and toluol was completely removed at 90 to 100°C under reduced pressure of 15 mmHg. The infrared absorption spectrum of the obtained dioctyltinbis(isooctylthioglycolate) is shown in Figure 3.
Shown below. This absorbance ratio (1560cm ^-1 /1740cm ^-1 ) is
It was 0.46. This compound had a much stronger mercapto odor than that of Example 1. Comparative Example The same thioglycolic acid 2-
After 412 g (2.01 mol) of ethylhexyl was charged and stirred, 361 (1 mol) of dioctyltin oxide was added.
was added and the temperature was raised to 70°C, and after treatment under reduced pressure of 15 mmHg or less until almost all the distillate was gone, the temperature was raised to 98°C. Next, when no by-products were distilled out under the conditions of 95-100°C x 10-20mmHg, the pressure was returned to normal pressure, cooled to 70°C, and filtered. Figure 4 shows the infrared absorption spectrum of the obtained dioctyltinbis(2-ethylhexylthioglycolate) measured with an infrared spectrophotometer. Figure-4
The absorbance ratio (1560 cm ^-1 /1740 cm ^-1 ) was 0.3. It should be noted that the mercapto odor was stronger compared to this example and the examples. Example In the example, 408 g (2 mol) of thioglycolic acid isooctyl ester was mixed with 612 g (3 mol),
Monobutyltin tris(isooctylthioglycolate) was synthesized in exactly the same manner as in Example except that 361 g (1 mol) of dioctyltin oxide was replaced with 208.8 g (1 mol) of monobutyltin hydroxide. The obtained compound had almost no odor. In addition, the absorbance ratio according to the infrared absorption spectrum of this compound (1560 cm
^-1 /1740cm ^-1 ) was 0.001. Application Example Each formulation was prepared from 100 parts by weight of vinyl chloride resin (=700), 1 part by weight of stearic acid, and 2 parts by weight of the stabilizer of each Example and each Comparative Example, and the odor thereof was examined. Thereafter, each formulation was run at rotational speeds of 21 and 19 r.p.
m., the temperature is 170℃, and the sheet is kneaded for 5 minutes with two 6-inch rolls with a roll interval of 0.3 mm, and this sheet is molded into a mold with a thickness of 2 mm, a width of 15 cm, and a length of 20 cm. Using press temperature 180℃, total pressure
After pressing at 200 kg and a temperature of 180° C. for 5 minutes, the sheet was cooled to room temperature to obtain a pressed sheet. We compared and examined their transparency. The results are shown in the table.

【table】 [Brief explanation of the drawing]

Each figure is an infrared absorption spectrum diagram of each product compound of the following corresponding example and comparative example. Figure-1: Example, Figure-2: Example, Figure-
3: Comparative example, Figure-4: Comparative example.

Claims (1)

[Claims] 1 HS(CH ₂ )nCOOR (wherein R has 6 to 18 carbon atoms
is an alkyl group, alkenyl group, or alkoxyalkyl group, and n is an integer of 1 or 2. )of,
Heat treatment at a reduced pressure that does not allow the compound to distill out, or
Or, after removing low-boiling compounds by introducing nitrogen gas to prevent the compounds from flowing out, [Formula] [Formula] and [Formula] (where R' is an alkyl group having 1 to 8 carbon atoms) A method for producing an organic tin mercaptocarboxylic acid ester salt stabilizer for halogen-containing resins, which comprises adding and reacting at least one selected from the following, and removing by-product water under conditions of 60°C or lower and 100mmHg or lower. .