DE1192825B - Process for coagulating aqueous emulsions of vinyl polymers obtained by polymerization - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. α .:

Number:
File number:
Registration date:
Display day:

C08f

German class: 39 c -25/01

M54885IVd / 39c
November 20, 1962
May 13, 1965

In the manufacture of various types of polymeric materials according to the emulsion polymerization method a colloidal dispersion of polymer particles is obtained in the form of an emulsion. Emulsifiers such as fatty acid soaps or water-soluble salts of organic sulfonic and sulfuric acids, are usually used to aid the dispersion process. The thus obtained Emulsion is known as polymer latex, from which the raw polymer is obtained by means of coagulation is won. When the polymer latex consists of an aqueous emulsion in the usual way, was it so far due to the very high stability and resistance to coagulation of the Emulsion required, disadvantageous and costly techniques for carrying out coagulation of the polymer latex. The previously known method for coagulating Polymer latexes include work steps such as freezing out, heating, adjusting the pH value, adding from salt water, acid, alum or other salts. Although such methods vary somewhat The extent to which they give the desired coagulation satisfactorily, they have disadvantages and prove to be to be slow and ineffective. For example, the freezing or heating of large volumes made difficult to latex by the relatively low thermal conductivity of latex, and to do so To overcome this, an expensive and carefully designed device is needed to control the coagulation to achieve. In addition, the addition of foreign chemicals to bring about the coagulation of Polymer latices only applicable if the introduction of a foreign material into the product does not occur proved to be disadvantageous for the further processing of the polymer.

There has now been a method of coagulating aqueous emulsions obtained by polymerization found of vinyl polymers in the polymer emulsions very easily with the release of the polymer broken or destroyed by it in a weakened or unimpaired condition can be that the emulsions by adding 0.5 to 5.0 percent by weight of a coagulant the general formula

in which η is an integer from 1 to 3, flocculates.

Preferably, 0.8 to 1.5 percent by weight of said alkylolsulfuric acids are sufficient for a good one Coagulation or flocculation.

Method of coagulating by
Polymerization obtained aqueous emulsions of vinyl polymers

Applicant:

Monsanto Company, St. Louis, Mo. (V. St. A.)

Representative:

Dr. E. Wiegand and Dipl.-Ing. W. Niemann,

Patent Attorneys, Munich 15, Nussbaumstr. 10

Named as inventor:

Lloyd Theodore Jenkins, Cary, N. C. (V. St. A.)

Claimed priority:
V. St. v. America November 20, 1961
(153 680)

The compounds contemplated according to the above general formula are methylol sulfuric acid, Ethylol sulfuric acid and propylene sulfuric acid.

The coagulants used in the process of the invention are effective regardless of which method Type of aqueous emulsion polymerization system used, namely to a wide variety of polymer, mixed polymer and terpolymer systems.

Emulsions of vinyl polymers which can be flocculated according to the process of the invention, are polymer emulsions of acrylonitrile, including polyacrylonitrile-acrylonitrile copolymers, binary and ternary polymers with a content of at least 80 percent by weight acrylonitrile in the polymer molecule. For example, the polymer made of polyacrylonitrile or copolymers, which Contain polyacrylonitrile with 2 to 50% of another polymeric material, the mixture having a total content of polymerized acrylonitrile of at least 80 percent by weight exist. Although the in the method according to the invention used preferred polymers are those which at least Contain 80% acrylonitrile and are generally known as fiber-forming acrylonitrile polymers,

509 569/387

it can be seen that the invention can be applied in the same way to vinyl-substituted tertiary heterocyclic! Amine

is applicable to polymers which are less than from 2 to 10%, based on the weight of the mixture,

Contains 80% acrylonitrile. Contains acrylonitrile polymers.

containing less than 80% acrylonitrile. The invention is equally applicable to halogen for the formation of films, coating compounds, 5 olefinic polymer emulsions, such as Molding compounds for making molding emulsions from polyvinyl chloride and from mixing passages or varnishes usable. polymers of vinyl chloride and vinyl acetate,

For example, the polymer made of a vinyl propionate, vinyl butyrate, vinylidene chloride, acrylic

Copolymer with 80 to 99% acrylonitrile and ibis nitrile, ethyl acrylate, methyl methacrylate, methyl 20% ^emes other monomers, which is the io Λ-chloroacrylate, maleic acid, fumaric acid, diethyl

Contains> C = C <bond and with acrylonitrile maleate or diethyl fumarai. Other vinyl compounds

is copolymerizable exist. Suitable monogens, the polymer emulsions of which after the

olefinic monomers are acrylic acid, a-chloroacrylic drive of the invention can be flocculated,

acid and methacrylic acid, the acrylates, such as methyl- are the conjugated butadienes, such as butadiene- (1,3),

methacrylate, ethyl methacrylate, butyl methacrylate, 15 isoprene, 2,3 - dimethylbutadiene - (. 1,3), chloroprene,

Methoxymethyl methacrylate, / S-chloroethyl methacrylate piperylene, polymer emulsions from monomer

and the corresponding esters of acrylic and «chlorine mixtures of two or more of these conjugate

acrylic acid, vinyl chloride, vinyl fluoride, vinyl bromide, yawed butadienes, such as a mixture of butadiene

Vinylidene chloride, 1 -chloro-1-bromoethylene, methacrylic (1,3) and 2,3-dimethylbutadiene-fl, 3) and monomer

nitrile, acrylamide and methacrylamide, α-chloroacrylic mixtures of one or more of these conjunct

amide or their monoalkyl substitution products, gated butadienes with vinyl compounds such as styrene,

Methyl vinyl ketone, vinyl carboxylates, such as vinyl acetate, p-chlorostyrene, p-methoxystyrene, vinyl naphthalene,

Vinyl chloroacetate, vinyl propionate, vinyl stearate and acrylic acid, methacrylonitrile, methyl methacrylate,

Vinyl levulinate, N-vinylimides, such as N-vinylphthalimide, methyl acrylate, methyl vinyl ketone, methyl isopropenyl

and N-vinyl succinimide, methylenemalonic acid ester, ketone or methyl vinyl ether. The procedure according to

Itaconic acid and itaconic acid ester, N-vinylcarbazole, the invention is particularly applicable to polymer

Vinyl furan, alkyl vinyl ester, vinyl sulfonic acid, ethylene emulsions from copolymers of butadiene

α, / 5-dicarboxylic acids or their anhydrides or deri- and styrene or acrylonitrile, isoprene and styrene or

vate, such as diethyl citraconate, dimethyl mesaconate, di-acrylonitrile and other rubbery mixed poly

ethyl mesaconate, styrene, vinylnaphthalene, vinylsubsti- 30 merisates as well as on polymer emulsions of the poly-

tertiary heterocyclic amines such as vinyl vinyl chloride, polyvinyl acetate, polystyrene, poly

pyridines and alkyl-substituted vinyl pyridines, such as methyl methacrylate, polyynylidene chloride, polyvinyl

2-vinylpyridine, 4-vinylpyridine, 5-methyl-2-vinylpyripyridines and the various other addition

din, 1-vinylimidazole and alkyl-substituted 1-vinyl polymers, which by means of the emulsion process

imidazoles, such as 2-, 4- or 5-methyl-l-vinylimidazole, 35 can be prepared,

and similar> C = C <-containing polymerizable The invention is illustrated by the following

Materials. Examples explained in more detail in which all part and

The polymer can be based on ternary mixed polymer percentages by weight. the

seeds consist, for example, of products that are not produced by the preparation of the polymer emulsions

Copolymerization of acrylonitrile and two or 40 subject of the invention,
any of any of those enumerated above

other monomers except acrylonitrile prepared Example 1
have been. The ternary polymer preferably comprises acrylonitrile, methacrylonitrile and 2-vinylpyridine. ^A customary emulsion copolymerization The ternary polymers preferably contain 80 45 was carried out with acrylonitrile vinyl levulinate using up to 97% acrylonitrile, 1 to 10% of a vinylpyridine, a potassium persulfate-sulfur dioxide catalyst or a 1-vinylimidazole and 1 to 18% of a system, with the The following proportions of other substances such as methacrylonitrile or vinyl were used: 5 parts of water, 0.75 parts of acrylic chloride. nitrile, 0.25 part vinyl levulinate, 0.014 part K ₂ S ₂ O ₈ ,

The polymer can also consist of a mixture of 5 <> 0.006 parts SO ₂ . The reaction was continued until

carried out by polyacrylonitrile or a binary mixed polymer and a smooth emulsion

sat formed from 80 to 99% acrylonitrile and 1 to 20%.

This emulsion containing at least one other> C = C <was about 1 percent by weight

Substance with 2 to 50 percent by weight of the mixture methylol sulfuric acid added with stirring. the

a copolymer of 10 to 70% acrylonitrile 55 emulsion was quickly destroyed or collapsed,

and 30 to 90% of at least one other ^{and the} polymer was easily filtered through

> C = C <containing polymerizable mono- obtained.

mers exist. If the polymeric material is an example2
Comprises mixture, it preferably consists of one

Mixture of a copolymer of 90 to 98% ^6o An emulsion copolymerization was developed

Acrylonitrile and from 2 to 10% of another mono speaking, as described in Example 1, under

olefinic monomers, such as vinyl acetate, which turn 0.5 parts of acrylonitrile and 0.5 parts

is not receptive to dye, carried out with a vinyl levulinate. A smooth one forms

sufficient amount of a copolymer of emulsion.

10 to 70% acrylonitrile and 30 to 90% of a vinyl 65 This was with about 1 weight percent methylol

substituted tertiary heterocyclic amine, such as sulfuric acid, which was added with stirring,

Vinylpyridine or 1-vinylimidazole, coagulated to a dye. The emulsion was quickly destroyed again

To give bare mixture, which has a total content and the polymer easily recovered by filtration.

Example 3

Example 2 was repeated with the difference that vinyl acetate instead of vinyl levulinate in the same proportions were used. The emulsion quickly collapsed again, and so did the polymer was easily won.

Example 4

It was polymerized according to the procedure given in Example 1 with the difference that one Emulsifier was added.

The emulsion collapsed rapidly when 1% methylol sulfuric acid was added.

When using other coagulants, * 5 such as ethylol sulfuric acid, similar results are obtainable according to the invention. One in the same way Satisfactory polymer coagulation is possible when polymers of butadiene, vinyl chloride and other related compounds can be used.

Claims (2)

Patent claims: 1. Process for coagulating aqueous emulsions obtained by polymerization of Vinyl polymers, characterized in that the emulsions by adding 0.5 to 5.0 percent by weight of one Coagulant of the general formula HO- (CH ₂ ) ^ - SO ₃ H in which η denotes an integer from 1 to 3, flocculates. 2. A method for coagulating aqueous emulsions of acrylonitrile polymers, characterized in that that the emulsions by adding 0.5 to 5.0 percent by weight of a coagulant the general formula HO - (CH ₂ J _n -SO ₃ H in which η is an integer from 1 to 3, flocculates. 509 569/387 p. 65 © Bundesdruckerei Berlin