CS230056B1 - A method for producing stable emulsion emulsifiers - Google Patents

Abstract

The production of stable initiator emulsions for suspension or microsuspension homopolymerization and/or copolymerization of vinyl monomers is carried out by adding an organic initiator and/or a solution of the initiator in an internal solvent to an aqueous solution containing at least two different types of surfactants in a total amount of 0.1 to 20% by weight and stirring the mixture vigorously. The weight ratio of water to solution initiator is 5:95 to 97:3 and the concentration of the peroxide component in the emulsion is 3 to 80% by weight. A combination of sodium alkyl sulfonate in an amount of 0.005-3% by weight (0.05-0.8%), partial esters of polyhydric alcohols with higher fatty acids (partially saponified fat) in an amount of 0.01-5% by weight is particularly suitable. (0.2 - 1%) and polyvinyl alcohol, respectively, partially saponified polyvinyl acetate in the amount of 0.1 - 10% by weight. (0.2-1.5%)

Description

230 OSO

The present invention relates to a process for the production of initiator emulsions suitable for the production of suspension polymerization and / or copolymerization of vinyl monomers.

For suspension polymerization, respectively. copolymerization of vinyl monomers commonly used as polymerization initiators are various organic substances capable of generating free radicals capable of initiating a polymerization or copolymerization reaction at a given polymerization temperature. A large number of compounds are known to switch the aforementioned assumption, but the most commonly used are organic compounds containing one or more peroxidic groups in the molecule. The most commonly used types of peroxide compounds include dialkanoyl peroxides, peresters, and percarbonates.

These substances are used either as solids or as dust initiators, such as, for example, dilauroyl peroxide, dicetyl percarbonate and the like, or as liquid initiators, and in the pure state, but more often as solutions of these liquids in an inert solvent. Liquid initiators may include, for example, short short chain percarbonates. Nowadays, the use of powdered initiators is being phased out and converted into liquid solution initiators, which have several advantages over powdered initiators. Advantages of the liquid initiators are in particular the simple preparation in the usable form, the easier handling, and the possibility of automatically dispensing the initiator into the polymerization autoclave. The disadvantage of the solution initiators is that they need to be stored at temperatures substantially lower than those of the powder initiators (the need for cooling boxes) and the fact that some alkanes and aromatics that are flammable are usually used as inert solvents, and therefore they must be treated accordingly. 230 058

It is known (U.S. Pat. No. 3,507,800) that the flammability of dialkyl ketone peroxides (methyl ethyl ketone peroxide, methyl isobutyl ketone peroxide, cyclohexanone peroxide) in diethyl ether is reduced sharply if 18 to 50% water is added to said substances. a suitable, water-soluble polyalkylene glycol and emulsify the mixture to form a smear. However, these initiators are unsuitable for polymerization of vinyl monomers.

A more interesting aspect of the vinyl monomer is U.S. Pat. According to the description of the emulsion initiator in suspension polymerization, respectively. vinyl chloride copolymerization. In the examples, the bis-sec-butylperoxydicarbonate and acetylo-cyclohexane-sulfonyl peroxide are exchanged as initiators. Emulsions still at temperatures of 2 to 7 ° C are obtained by introducing into the aqueous solution containing 1 to 5% by weight of polyvinyl alcohol and 1 to 6% by weight of polyvinyl alcohol. polyoxyethylene sorbitan monolaurate also adds an amount of initiator such that the resulting emulsion contains up to 19 wt. active substance. However, the obtained emulsion is unstable, similar to that of other emulsifiers, which are prepared in situ in the emulsion, namely the alkali metal chlorides. Higher concentrations of the active ingredient in the emulsion are referred to as being unsuitable from the market for the reason of the rapid increase in emulsion viscosity.

According to the present invention, a process for the preparation of stable emulsions of initiators for suspension or microsuspension homopolymerization and / or copolymerization of vinyl monomers is carried out by incorporating into the aqueous solution containing at least two different types of surfactant surfactants: sodium alkylsulfonate to alkyl Sodium alkylarylsulphonate, alkylarylsulphonate ammonium, alkylaryl sulphonate, alkylaryl sulphonate amine or alkanolamines; ,

230 OSO polyglycol, alkylpolyglycol, alkylpolyglycol with alkyl- to C20, alkaline or hydroxyalkylammonium salt of phosphated alkylpolyglycol, ethylene oxide propylene oxide, alkyifeaylpolyglycol, in an amount of 0.1 to 20% by weight. adding the initiator and / or initiator solution in the in-solvent and intensively mixing the mixture, wherein the weight ratio of water to solution initiator is 5: 95 to 97: 3 and the peroxide concentration of the emulsion is 3 to 80% by weight. The advantage of the emulsion production method! The present invention provides a stable emulsion that is non-combustible, handy, easy to transport, and suitable for automatically dispensing emulsion initiator polymerization even in the aqueous phase stream. For this purpose, initiator emulsions may be diluted by dilution to the desired endpoint before use. Another advantage is that the initiator emulsion can be fed at temperatures of 0 to 10 ° C for several weeks without decreasing the concentration of the active peroxide component. Also of note is the fact that only small amounts of commonly available surfactants are used in the preparation of the emulsion of the invention. On the other hand, some application-determining emulsions can be used, even at higher concentrations, for selected types of surfactants not only to prepare emulsions of initiators, but also in the next step, to utilize their effect on effected suspension or microsuspension polymerization and / or copolymerization. vinyl monomers.

The initiators which can be used to form the emulsions of the present invention include various liquid percarbonates and peresters, as well as mixed liquid initiators, as well as mixtures of said compounds, but the primary solid peroxides soluble in the organic solvents. In the form of a solution, dibenzoyl peroxide, in particular in combination with liquid percarbonates, can also be emulsified.

The term copolymerization also includes cleavage and cleavage, respectively. seeding the polymers and copolymers with the monomers and the inert initiator of the initiator are individually organic compounds or mixtures of organic solvents which dissolve the initiator or mixture of initiators well, but do not react with them under normal conditions. Examples of such solvents are aliphatic and aromatic hydrocarbons, as well as their halogenated derivatives, especially chlorinated, optionally alcohols and ethers. Among the most important surfactants suitable for the implementation of emulsion initiators are those esters of polyhydric alcohols, especially those with higher fatty acids, with partially esterified glycerol, including partially saponified fats, partially esterified pentaerythritol and dipenta-erythritol, and others partially esterified diols to polyols, acotrimethylolpropane, neopentyl glycol, ethylene glycol and polyglycols, hydrogenated glycides and the like. Another type of polymeric polyols include polyvinyl alcohol, partially saponified polyvinyl acetate, and polyvinyl alcohol generally includes partially saponified polyvinyl acetate. Another type is the typical anionic surfactants such as alkylarylsulphonates 8 by alkyl® »Cu to C14 > and the anionic salts of 230 056 alkylarylsulfonic acids, the alkali metal salts of alkyl sulfonic acids with alkyls of C 2 - 2 and% 18 18 or hydroxyalkylamine salts of phosphatized alkyl polyglycols. Less suitable but useful are typical non-ionic surfactants, such as alkyl polyglycols and acyl polyglycols with alkyls up to C20 and alkylphenyl polyglycols. In the following examples, processes for the production of initiator emulsions as well as their use for the suspension polymerization of vinyl chloride are given. The concentrations reported in the examples are calculated in% by weight on the weight of the emulsion formed. Also, the data of the individual compounds are given in% by weight, calculated as pure substance (100%) and also converted to hmuxnoet emulsion. Example 1 • 3

To a 2 dm flask, a solution containing 0.2 wt. % of sodium alkylsulfonate (Merso-lath mixture of the formula R-SO2-Naa, where R = alkyl C12-C18 in the form of an aqueous solution having a conc. pare. glycerol fatty acid esters (Emulsifier C; mixed ester of glycerol with stearic acid, optionally also oily - partially esterified glycerol; melting point max. 40 ° C; monoglyceride content up to 30% by weight, acid value 10 mg KOH % g) and 0.7 wt. polyvinyl alcohol (vial R; aqueous polyvinyl alcohol solution having a saponification number of 130 mg KOH / g; viscosity of the aqueous solution at 20 ° C of 4% w / w 11 to 15 mPa.s) in an amount of 233.3 g. 266.7 g of a mixture of initiators (composition: 70% by weight of bis-2-ethylhexyl peroxydicarbonate, 25% by weight of benzoyl peroxy-2-ethylhexyl carbonate and 5% by weight of dibenzoyl peroxide) are poured into the solution at 10 ° C with stirring. 50 wt. active peroxide. The mixture in which the water to organic phase ratio is 1: 1.15 is allowed to stir vigorously at 5 ° C for 20 min. The emulsion formed had a concentration of 26.7 wt. The peroxide component is stored in thermostat at 5 ° C for 2 weeks. After 2 weeks, the emulsion is still stable and the concentration of the active peroxide component remains unchanged. Example 2 230 056

Emulsions prepared by the same procedure as in Example 1 but containing 0.2 wt. sodium alkylsulfonate (Mersolat), 0.8 wt. % emulsifier C and 1.2 wt. % polyvinyl alcohol (Sloviol R) containing 26.7 wt. The active peroxide component does not exhibit a loss of peroxidic component after 3 weeks of standing at 3 ° C and emulsion coagulation or coagulation is not observed. Example 3

An emulsion containing 0.7 wt. sodium alkyl sulfonate (Mer-solat), 0.5 wt. saponified fats and 1% by weight of saponified polyvinyl acetate are prepared by

In Example 1. After 10 days, no loss of peroxidic active ingredient is observed in the 6 ° C thermostable emulsion and no coagulation or emulsion breakdown is observed. Example 4

The emulsion preparation process is similar to Example 1, but with the difference that the emulsion formed contains 0.5 wt. sodium alkyl sulfonate, 0.5 wt. % of the partially esterified glycerol and 0.5 wt. polyvinyl alcohol, wherein the peroxide component concentration is 33.3% by weight. and the water to organic phase ratio is 1: 2. The emulsion does not change the concentration of the superoxide component after 3 weeks of storage at 4 ° C and is also stable from colloidal hl'adiska. Example 5

The emulsion was prepared in a similar manner to Example 1, except that the resulting emulsion contained 0.1 wt. sodium alkyl sulfonate, 0.5 wt. partially esterified glycerol and 0.5 wt. polyvinyl alcohol. The peroxide component concentration is 22.2% by weight, the water to organic phase ratio is 1.25: 1. After 2 weeks of storage of the emulsion at 5 ° C, the peroxide concentration does not change and the colloidal emulsion does not change practically. Example 6 230 056

The emulsion formation process is similar to Example 2, except that the xylene solution of bis-2-ethylhexyl peroxydicarbonate is used instead of the initiator mixture solution. 50 wt. Even after 2 weeks of thermostating at 2 ° C, the emulsion is similar to that of the active peroxide component * Example 7

The emulsion is prepared in a manner similar to that described in Example 5, but a mixture of initiators (20% w / w 2-ethylhexyl peroxydicarbonate, 55% w / w benzoyl peroxy-2-ethylhexyl carbonate and 25% w / w dibenzoyl peroxide) is used as the active ingredient. xylene solution of conc. 30 wt. After 2 weeks of standing at 10 ° C, no change in total peroxide concentration was observed. Example 8

The procedure is similar to that described in Example 4, but using the toluene solution of n-butyl peroxydicarbonate okonc as the initiator. 50 wt. At 0 G, the tempered emulsion for 10 days does not indicate a decrease in the active substance concentration. Example 9

29 kg of water, 1 kg of methylhydroxypropylcellulose (MethocellF-50) in the form of an aqueous solution of conc., Are metered into a 50 .mu.l stainless steel autoclave. 2 wt. and 52 g of the emulsion initiator prepared according to Example 4, tempered at 5 ° C for 10 days. After purging with nitrogen, 20 kg of vinyl chloride are metered in and the autoclave contents are heated to a polymerization temperature of 5 ° C. A pressure drop is observed after 5 h. Do not refrigerate the autoclave and the product is balanced after drying. The conversion rate reaches 84%, while in the case of the comparative experiment, where the same molar amount of the same non-emulsified initiator is used, the conversion after 5 h is 86%.

230 OSO

Initiator emulsion containing 0.4% by weight of partially esterified glycerol, respectively. % saponified fat and 0.6 wt. polyvinyl alcohol (Sloviol R) is prepared similar to Example 1. The concentration of oxides is 25% by weight. When this emulsion is stored at 3 ° C for 10 days, neither its precipitation nor the decrease in peroxide concentration is observed.

AND

Claims (3)

OBJECT OF THE INVENTION 230 036 A process for the manufacture of stable emulsion emulsifiers for suspension or mlcrosuspension homopolymerization and / or co-polymerization of vinyl monorers, characterized in that an aqueous solution comprising at least two spirits of surfactants from these surfactants is sodium: alkylsulfonate to alkyl C 1-6 alkyl, sodium alkyl aryl sulphonate, ammonium alkylarylsulphonate, alkylarylsulphonic acid addition product with amines or alkanolamines, carbon oval alkyl to C 1-6 partial esterified multivalent alcohol with fatty acids Ο to g g, partially saponified fats, polyvinyl alcohol, partially saponified polyvinyl acetate, polyglycol, alkyl polyglycol, acyl polyglycol with alkyl C 8 to C, alkaline or hydroxyalkylamine salt of phosphated alkyl polyglycol, copolymer of ethylene oxide with propylene oxide, alkylphenyl polyglycol, in a total amount of 0.1 to 20% by weight. adding an initiator and / or initiator solution in an inert solvent, and vigorously mixing the mixture, wherein the water to solution initiator weight ratio is 5: 95 97: 3 and the concentration of peroxide component in the emulsion! is 3 to. 80 wt. 2. A process according to claim 1, characterized in that an aqueous solution containing sodium alkylsulfonate with an alkyl content of from 0.005 to 3% by weight is used, preferably 0.05 to 0.8% by weight. and partially esters of polyvalent alcohols with fatty acids C10 to C18, in an amount of 0.01 to 5% by weight, preferably 0.2 to 1% by weight. and polyvinyl alcohol in an amount of 0.1 to 10% by weight, preferably 0.2 to 1.5% by weight, is added to the initiator solution in an inert solvent. 3. A process according to claim 1 or 2, wherein the weight ratio of water to solution initiator is 5: 95 to 97: 3, preferably 15 to 85 to 50: 50, and 10% of the peroxide in the emulsion! is from 3 to 80% by weight, with the preference of 20 to 50% by weight · Printed by Moravské tiskařské závody, provoz 12, Leninova 21, Olomouc Price: 2,40 Kčs