DD257432A1 - PROCESS FOR PREPARING POLYMERS OF VINYL CHLORIDE - Google Patents

Abstract

The invention relates to a process for the preparation of polyvinyl chloride with high Porositaet by the suspension process. The process is designed such that polysiloxane-polyoxyalkylene block copolymers are used as suspension stabilizers and di- and / or triallyl compounds known to the polymerization batch are added. Centrifuge plasticizer exposures of greater than 25% are achieved.

Description

Field of application of the invention

The invention relates to a process for the preparation of polymers of vinyl chloride by radical polymerization of vinyl chloride and predominantly vinyl chloride-containing monomer mixtures by the suspension process.

Characteristic of the known technical solutions

The suspension polymerization of vinyl chloride or the preparation of copolymers based on vinyl chlorides is carried out on an industrial scale in the presence of dispersants for the preparation and stabilization of the vinyl chloride / polyvinyl chloride suspension in the aqueous phase. It agrees u.a. the property of the dispersant system, the distribution of the monomer in the aqueous phase, the morphology of the PVC grain, in particular its porosity, the particle size distribution or the thermostability of the polymer. For the processing of the polyvinyl chloride, particularly the bulk density and the plasticizer capacity are of crucial importance. However, both properties are related so that, generally, one size deterioration occurs in the improvement of one size.

As dispersants u.a. Cellulose ethers, as described in DE-OS 2412014, in question. Furthermore, cellulose ethers in a mixture with partially hydrolyzed polyvinyl acetate (DD-PS 145539) or with polyvinyl acetate (DE-AS 1142238) are optionally used in conjunction with nonionic emulsifiers (DE-OS 2945073). To achieve high porosities, additional aliphatic or aromatic hydrocarbons or alcohols are used (US Pat. No. 2875186, US Pat.

It is also known, by adding long-chain fatty acids or their esters or by adding ionic or nonionic surfactants, often combined with other additives, such as reducing agent to the polymerization to increase the plasticizer receptivity (DE-OS 2365134,2151703, DE-PS 1545179, DE -OS 2244905.2134604).

Also described is the combination of suspension stabilizers to influence the plasticizer receptivity

(US Pat. No. 3,879,365, DE-AS 1720328, DE-OS 2209892).

A polyvinyl chloride having a high bulk density of low porosity and a relatively broad particle size distribution is obtained when using styrene / maleic anhydride copolymers as a dispersant (DD-PS 13583.14358).

Furthermore, a polyvinyl chloride having a relatively high bulk density and a good porosity by addition of diallyl or triallyl compounds to the commonly used dispersants or their mixtures (DD-PS 151455).

The known methods have the disadvantage that they affect only one size positively and the others are neglected, d. H. With a high bulk density, one obtains low porosities or vice versa.

Due to the large number of additives, it is often necessary to reduce the deterioration of other product properties, such as i.a. take the thermostability in purchasing.

Object of the invention

The aim of the invention is to produce a polyvinyl chloride with high porosity by the suspension process.

ti description of the essence of the invention

The technical problem which is solved by the invention

The object of the invention is to develop a process for the suspension polymerization of vinyl chloride or predominantly vinyl chloride-containing monomer mixtures, which makes it possible to produce polymers having a high porosity in the presence of known radical-forming initiators or initiator systems. _u

Features of the invention

The object is achieved in that the suspension stabilizers polysiloxane-polyoxyalkylene block copolymers of the general formula

/ SiR »0 / _m ^

/ SiR ⁷ Q / _m

/ _{n / 2} w

EJSiO / SiBO / _{m / 3} / SiR ^ O / _{n / 2} / SiEO / ^ ₃ SiEJ

n / 2

(HI)

in which mean:

R '- identical or different lower, optionally substituted alkyl radicals; preferably methyl groups m - integers or fractions between 1 and 12, preferably between 2 and 5 η - integers or fractions between 30 and 250, preferably between 40 and 120 G - polyoxyalkylene glycol acetate, oil, alkoxylate, cyanoalkoxylate or urea radical of the general formula - / CH ₂ / 3- / OCH ₂ CH ₂ / _p - / OCH ₂ GH (CH ₃ ) / _q -R '

R '-OCOCH ₃ , -OH ₁ -OCH ₃ , -OC ₄ H ₉ , -OCH ₂ -CH ₂ CPi-OCONHR "

R "is alkyl or aryl radical

p, q whole or fractional numbers between 4 and 50

in concentrations between 0.001 to 0.3% by mass, based on the aqueous phase, and in which diallyl- and / or triallyl-containing compounds, known to the polymerization batch, are present in a concentration of from 0.0001 to 0.1% by mass, based on the Monomers are added.

Diallyl and / or triallyl compounds, such as polyallyl phosphates, z. Triallyl phosphate, di- and / or triallyl ether, e.g. B. Trimethylolpropandiallyläther, Hexantrioldiallyläther, Äthylenglycoldiallyläther, Hyceroldimethylallyläther, di- and / or triallyl esters, z. As diallyl phthalate, diallyl, diallyl maleate, diallyl fumarate, DiallylterephthalatTriallylcyanurat, diallyladipinate, diallyl succinate, diallyl sebacate, pentaerythritol triacrylate or methacrylate, Hexandioldiäcrylat / Triäthylenglycoldiallylfumarat, Poläthylenglycoldimethacrylat, Polyäthylenglycoldiacrylat, Polyäthylenglycoldimethylmethacrylat and / or Allyläther allylester suitable.

embodiments

Example 1 to 11

An oxygen-free rinse autoclave was charged with 400 parts of water, 200 parts of vinyl chloride, 0.13 part of lauroyl peroxide and 0.23 part of dicetyl peroxydicarbonate. The concentrations of polysiloxane-polyoxyalkylene block copolymers (PPB) and of the allyl compounds are shown in Table 1. Was polymerized at 6O ⁰ C.

Table 1 PPB allyl compound concentration bulk centrifugal K value C F at Ma .-% bez. Wt .-% ref.A. mass genweich- around game a. water vinyl chloride g / i macher- admission% 0.05 608 21.8 63.7 159 1.52 1 0.05 diallyl 0.02 485 27.6 68.2 152 1.83 2 0.05 diallyl 0.03 473 28.2 70.0 151 1.84 3 0.04 diallyl 0.02 463 26.9 69.1 162 1.73 4 0.05 diallyl 0.005 523 24.1 65.2 156 1.63 5 0.05 diallyl 0.02 502 25.8 66.1 161 1.78 6 0.05 diallyl 0.02 493 26.3 67.8 158 1.73 7 0.05 diallyl 0.02 476 27.3 68.5 161 1.76 8th

at PPB allyl compound G _d5 concentration bulk centrifugal K value C F game Ma .-% bez. IVTa .-% rel. a. mass genweich- around a. water vinyl chloride g / i macher- admission% 9 0.05 triallyl 0.02 472 26.9 68.3 153 1.85 10 0.05 Äthylenglycol- diallyl 0.02 483 25.8 64.1 159 1.63 11 0.05 Pentacrylthritol- triacrylate 0.02 502 24.7 65.8 163 1.81 12 0.05 Diathylmaleate Oiathyladipate 0.01 0.01 487 26.4 67.9 152 1.76 c - mean grain diameter of the Gaussian distribution d - grain diameter G - Sum weight of the sieve fraction

Claims (2)

1. A process for the preparation of polymers of vinyl chloride by free-radical polymerization of vinyl chloride and predominantly vinyl chloride-containing monomer mixtures using known radical-forming initiators or initiator systems and the suspension process, characterized in that as suspension stabilizers polysiloxane-polyoxyalkylene block copolymers of the general formula E ^ SiO / SiR ¹ O / _m / SiEJO / _n SiS ^ (I) GEJSiO / SiE «0 / _m / SiEJO / _{Q / 2} - SiEJG / SiBj / _{n / 2} -: (H) B ^ SiO / SiEO / ^ ₃ / SiEJO / _{n / 2} / SiEO / _{m / 3} 0 G in which mean: R '- identical or different lower, optionally substituted alkyl radicals, preferably methyl groups m - integers or fractions between 1 and 12, preferably between 2 and 5 η - integers or fractions between 30 and 250, preferably between 40 and 120 G - polyoxyalkylene glycol acetate, alkoxylate, olecyanalkoxylate or ureate radical of the general formula - / CH ₂ / 3- / OCH ₂ CH ₂ / p- / OCH ₂ CH (CH 3) / q -R ' R 'is -OCOCH ₃ , -OCH ₃ , -OC ₄ H ₉ , -OK-OCH ₂ -CH ₂ -CN ₁ -OCONHR "R" alkyl or aryl radical p, q - integers or fractions between 4 and 50 in concentrations between 0.001 to 0.3Ma .-%, based on the aqueous phase is used, wherein the polymerization batch 0.0001 to 0.1 Ma .-%, based on the monomer, known diallyl and / or triallyl groups containing compounds added become. 2. The method according to item 1, characterized in that as diallyl and / or triallyl compounds Polyallylphosphate, z. B. triallyl phosphate, di- and / or triallyl ether, z. B. Trimethylolpropandiallyläther, Hexantrioldiallyläther, Äthylenglycoldiallyläther, Glyceroldimethallyläther, di- and / or triallyl esters, z. As diallyl phthalate, diallyl oxalate, diallyl diallyl fumarate, diallyl terephthalate, triallyl cyanurate, Diallyladipinat, diallyl succinate, diallyl sebacate, pentaerythritol triacrylate and methacrylate, hexanediol diacrylate, Triäthylenglycoldiallylfumarat, Polyäthylenglycoldimethacrylat, Polyäthyjenglycoldimethylmethacrylat, Polyäthylenglycoldiacrylat and / od, it can be used allyl ether-allyl ester.