DE1811472A1 - Chlorination of vinyl chloride or ethylene - polymers in the absence of chlorinated - Google Patents

Abstract

Vinyl chloride or ethylene (co)-polymer is chlorinated in aqueous hydrochloric acid suspension at 30-70 degrees C, using short-wave radiation and in the presence of a sulphur dioxide producing substance, e.g. sulphite, bisulphite, dithionite or pref. thionyl or sulphuryl chloride. 0.1-10% by wt. (calculated as available SO2 on the wt. of polymer) of these substances, with additionally 1-20% by wt. dimethylsulphoxide, gives the best results. This method gives an improved product as the imperfect removal of chlorinated hydrocarbon is avoided.

Description

Process for the chlorination of homopolymers or copolymers of vinyl chloride and / or ethylene in the manufacture of chlorinated polyvinyl chloride or polyethylene in aqueous suspension with the help of chlorine under irradiation with short-wave Light, one usually works with swelling agents such as chlorinated hydrocarbons, e.g. chloroform. The difficulties that arise during the processing, but are not insignificant, and the quality of the end product also depends significantly from the digestion of the grain by the swelling agent; compare DAS 1.138.547.

It is also known to work in the presence of reducing agents, where sodium sulfite, sodium bisulfite or the like are mentioned, but also at this procedure uses chlorinated hydrocarbons as swelling agents; compare DAS 1.254.866.

The present invention now relates to a process for chlorination of homopolymers or copolymers of vinyl chloride and / or ethylene in aqueous, salt acid suspension in the presence of a reducing agent at temperatures of 0 - 1000C, preferably between 30 and 7000, under irradiation with short-wave Light, which is characterized in that one is in the presence of sulfur dioxide or ohwefeligerSaure, which one uses either as such or in the Solution generated from corresponding inorganic sulfur compounds, in the absence of chlorinated Hydrocarbons works.

Surprisingly, the disadvantages mentioned at the beginning are eliminated avoided.

Sulfur dioxide, sulphurous acid or the sulfur dioxide or

Substances producing sulphurous acid are added in amounts of 0.03 - 20% by weight, preferably between 0.1 and 10% by weight, calculated as SO2 and based on towards the polymer, too.

Substances resulting from sulfur dioxide or sulphurous acid can one z.3. Alkali sulfites, alkali bisulfites, alkali dithionites or preferably thionyl or use sulfuryl chloride, the latter using SO2 or sulphurous acid Direct chlorination results. Corresponding alkaline earth salts, e.g. calcium, Barium or magnesium may be possible.

In addition, 1 - 20% by weight of dimethyl sulfoxide can advantageously be used, based on the polymer.

Polyvinyl chloride and / or polyethylene can be used as the starting material or copolymers of vinyl chloride and / or ethylene are used, with with regard to the production process, the molecular weight, the particle size distribution and the porosity of the raw material is not limited.

It is possible atactic or largely sterically ordered, so-called use tactical polyvinyl chloride or its copolymers. Mixtures of PVC and polyethylene or corresponding copolymers are preferred with one Share of 2 - 45% by weight polyethylene or

Used ethylene. Copolymers should also include graft polymers, e.g. of Vinyl chloride and ethylene or vinyl acetate and ethylene, be understood. The K values of PVC (according to DIN 53726) can be between 50 and 90 lie. As comonomers of the copolymers of vinyl chloride and / or ethylene can be used, for example: vinyl acetate, vinyl propionate, vinyl ether, vinylidene chloride, Acrylic and methacrylic acid esters, acrylonitrile, trichlorethylene, maleic and fumaric acid esters, Propylene, butylene, isobutylene or the like. The process according to the invention can also be carried out advantageously as a continuous process, the addition of the Starting material and the additives and the removal of the chlorination product continuously or can be carried out batchwise during the chlorination reaction.

The bulk weights of the PVC used are approx.

450 g / l, that of chlorinated PVC in the range from 500 to 550 g / l and thus higher than with known suspension chlorination processes. The chlorine content of the reaction product can amount to approx. 58 to 72% by weight for chlorinated PVC. The products obtained have a high resistance to water.

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The reaction can also be carried out in a stirrer and gas inlet tube the provided container.

The work-up of the chlorination product can be compared to the previous processes using chlorinated hydrocarbons are significantly simplified, there is only a short degassing under vacuum and subsequent washing or neutralization of the reaction mixture is required. The centrifugally moist product is trie usual, e.g. in a fluidized bed dryer, dried.

Example 1 Starting materials: 520 kg demineralized water, 6.5 kg S02Cl2, 130 kg PVC (K value 68) and 75 kg chlorine reaction temp .: 56 - 580C reaction time: 6.5 h The reaction is carried out in the apparatus described. In the submitted Water is added to 502012 while the pump is running, followed by PVC. The suspension is heated up.

After displacing the oxygen by evacuating and introducing The radiation sources (2 x 2 KW UV lamps) are switched on using chlorine gas. One doses until the desired degree of chlorination is reached. The reaction is ended by switching off the UV-S radiator.

The reaction mixture is degassed by a short vacuum distillation subjected, then washed, spun dry on a centrifuge and dried in a fluidized bed dryer.

Chlorine content: 66.7% Vicat: 1190C Example 2 Starting materials: 520 kg desalinated water, 6.5 kg 502012, 130 kg PVC (K value 55) and -75 kg chlorine Reaction temp .: 58 ° C reaction time: 11 h The procedure described in Example 1 is followed.

Chlorine content: 66.8% Vicat: 11200 Example 3 Starting materials: 5000 g Demineralized water, 60 g S02Cl2, 30 g SOCl2, 1250 g PVC (K value 68) and 800 g chlorine Reaction temp .: 57 ° C reaction time: 5.5 h The chlorination is carried out according to the example 1 is carried out. As a radiation source, however, in this Trap a 70 W UV lamp used.

Chlorine content: 67.5% Vicat: 1220C Heat stability at 18500: 100 min.

Example 4 Starting materials: 5000 g of deionized water, 60 g of SOCl2, 1250 g PVC (K value 68) and 800 g chlorine reaction temp .: 57 ° C reaction time: 5.5 h Man chlorinated as described in Example 3.

Chlorine content: 67.8% Vicat: 12300 Example 5 Starting materials: 5000 g demineralized water, 43 g S02Cl2, 900 g high-pressure Pol Säthylen, D = 0.918 and 1030 g chlorine Reaction temp .: 45 ° C reaction time: 3.9 h The reaction is carried out according to the example 3 carried out.

Chlorine content: 40.9% Vicat: 33 ° C. Example 6 Starting materials: 5000 g desalinated water, 43 g SO2C] 2, 900 g low-pressure polyethylene, D = 0.950 and 1060 g chlorine Reaction temp .: 59 ° C reaction time: 3.4 h The experiment was carried out as in the example 3 carried out.

Chlorine content: 41.3% Vicat: 61 ° C. Example 7 Starting materials: 5000 g demineralized water, 45 g SO2Cl2, 900 g high pressure polyethylene, D = 0.918 and 1800 g of chlorine.

Reaction temp .: 42 ° C. Reaction time: 8.6 h The reaction is carried out according to Example 3 carried out.

Chlorine content: 50.1% Vicat: 480C Example 8 Starting materials: 5000 g demineralized water, 197 g hydrochloric acid (33%), 62.5 g SO2Cl2, 1250 g PVC (K value 68) and 700 g of chlorine.

Reaction temp .: 6300 reaction time: 5.9 h chlorine content: 67.9 ffi Vicat: 129 ° C thermal stability: 100 min. At 185 ° C.

The chlorination is carried out according to Example 3, but with the Difference, that before the addition of 802012 to the water the specified narrow hydrochloric acid is added.

Example 9 Starting materials: 5000 g of deionized water, 50 g of NaHS03, 1250 g PVC (K value 68) and 800 g chlorine.

Reaction temp .: 58 ° C reaction time: 5.7 h It is chlorinated as indicated in example 3.

Chlorine content: 68.3% Vicat: 12700 Heat stability: 80 min. At 185 ° C.

Example 10 Starting materials: 5000 g of deionized water, 62.5 g of Na2S204J 1250 g PO (K value 68) and 800 g chlorine.

Reaction temp .: 60 ° C. reaction time: 6.1 h The reaction is carried out according to Example 3 carried out.

Chlorine content: 67.8% Vicat: 127 ° C thermal stability: 60 min. At 185 ° C.

Example 11 Starting materials: 5000 g deionized water, 25 g Na2S2O4, 62.5 g S02Cl2, 1250 g PVC value 68) and 770 g chlorine.

Reaction temp .: 63 ° C reaction time: 6 h The chlorination is carried out according to Example S carried out, however, using Na2S204 before adding SO2C12 to the water is added, chlorine content: 68.0% Vicat: 123 ° C Thermal stability: 60 min. At 185 ° C.

Example 12 Starting materials: 5000 g of deionized water, 197 g of hydrochloric acid (33%), 60 g S02, 1250 g PVC (K value 68) and 800 g chlorine.

Reaction temp .: 55-560C Reaction time: 7.8 h Into the provided water the hydrochloric acid is added first and the PVC after switching on the pump. The oxygen is displaced by introducing approx. 150 g of chlorine. After turning on Chlorine and 30 g SO2 in the first 1/2 hour are introduced into the radiation source. After an carbon consumption of approx. 440 g, 15 g SO2 and after 560 g carbon consumption are used Another 15 g SO2 were added. After an uptake of 800 g of chlorine, the reaction begins canceled and the product worked up in the manner described.

Chlorine content: 67.7% Vicat: 123 ° C Heat stability: 60 min. At 185 ° C.

The products obtained according to the examples were with the addition of 3% by weight of a barium-cadmium stabilizer, 2% montan ester wax and 0.2% calcium stearate processed into rolled skins in order to test the specified thermal stability.

The mill heads were at a rolling temperature of 1900C in 5 - 6 min. rolled out into foils with a thickness of .2 - o.4 mm.

Sections of these foils were placed in a drying cabinet heated to 1850.degree brought. The time taken for the films to turn brown was used as a measure for the thermal stability of post-chlorinated PVCs.

The polyethylenes described in Examples 5 and 6 had the following Melt indices: 190 Example 5: -I2: lo g 190 Example 6: 15: 1.5 g The determination is based on ASTM standard No. D 1238-T.

Claims (4)

P a t e n t a n s p r ü c h e 1. Process for the chlorination of homopolymers or copolymers of the Vinyl chloride and / or ethylene in aqueous, hydrochloric acid suspension at temperatures from 0 to 10,000, preferably between 30 and 70 ° C, under irradiation with short-wave Light in the presence of a reducing agent, characterized in that one Presence of sulfur dioxide or sulphurous acid, which you either used as such or in the solution of corresponding inorganic sulfur compounds produced, works in the absence of chlorinated hydrocarbons 2. Procedure according to claim 1, characterized in that sulfur dioxide, sulphurous acid or the substances producing sulfur dioxide or sulphurous acid in amounts of 0.03-20% by weight, preferably between 0.1 and 10% by weight, calculated as SO2 and based on the polymer used, adds. 3. The method according to claim 1 and 2, characterized in that one Substances that produce sulfur dioxide or sulphurous acid are alkali sulphites, alkali bisulphites, Use alkali dithionite or preferably thionyl or sulfuryl chloride. 4. The method according to claim 1 to 3, characterized in that one additionally 1 - 20 wt .-% dimethyl sulfoxide, based on the polymer, is used.