DE1133132B - Process for the manufacture of a synthetic rubber latex of increased particle size - Google Patents

Description

GERMAN

PATENT OFFICE

U7033IVd / 39c

REGISTRATION DATE: APRIL 4, 1960

NOTICE THE REGISTRATION AND ISSUE OF THE EDITORIAL: JULY 12, 1962

The invention relates to a method for producing a synthetic rubber latex from increased particle size. This process is characterized in that a rubber latex, obtained by polymerizing rubber-forming monomers in aqueous emulsion and of at least 5% unreacted, polymerizable, monomeric material based on the weight of the monomers originally used, contains 0.05 to 1 part by weight Äthylhydroxyäthylcellulose per 100 parts by weight of the originally used monomers at one Treated temperature from 0 to 15 ° C and on it removing the unreacted monomeric material from the latex.

The treatment of a synthetic rubber latex that contains unreacted, polymerizable, contains monomeric material, with a small amount of ethylhydroxyethyl cellulose before removing the unreacted monomers results in a latex the particles of which are of a size which is considerable is larger than the size of the particles of the same latex that does not contain the ethylhydroxyethyl cellulose was treated. Such latexes with ethylhydroxyethyl cellulose in the presence of the unreacted Monomers have been treated can easily, preferably 'by concentrating evaporation, concentrated into liquid latexes with high solids content.

The ethyl hydroxyethyl cellulose used according to the invention is known as a diluent, Emulsifier, dispersant or the like. In this respect it has the same properties as methyl cellulose. The addition of emulsifiers to a rubber latex is known, but it is in the stabilizers used here mostly to anionic emulsifiers such. B. organic sulfonates, Sulfates or salts of naphthenic acids. Most of all, these are emulsifiers or stabilizers always only added to the finished latex when it does not contain any excess monomers. Even then, the effect according to the invention cannot be achieved with these stabilizers not when it is nonionic stabilizers that are added.

For the purpose of carrying out the invention, the emulsion of the synthetic rubber-forming Monomers polymerized to a latex with a conversion of 60 to 95%, and the latex becomes then with 0.05 to 1%, preferably 0.1 to 0.6% ethyl hydroxyethyl cellulose, based on the original Weight of the rubber-forming mono-method of making a synthetic Rubber latex of increased particle size

Applicant:

United States Rubber Company,
New York, NY (V. St. A.)

Representative: Dr.-Ing. R. Poschenrieder, patent attorney, Munich 8, Lucile-Grahn-Str. 38

Claimed priority:
V. St. v. America May 4, 1959 (No. 810 597)

Victor S. Chambers, Naugatuck, Conn.,
and Louis Harold Howland, Watertown, Conn.
(V. St. Α.),

have been named as inventors

meren, at a temperature of 0 to 15 ° C in the presence of at least 5% of the unreacted polymerizable monomers, based on the weight of the original, the synthetic rubber-forming monomers treated. The duration of the treatment is not critical. The ethyl hydroxyethyl cellulose can be added to the latex simultaneously with or after the addition of the polymerization inhibitor and after the desired conversion of 60 to 95% has been established, and the monomers contained therein can then be removed. When the ethyl hydroxyethyl cellulose is added to the starting emulsion of the monomers, it can be in contact with the latex for such a time that the polymerization is generally carried out for no more than 24 hours. The ethyl hydroxyethyl cellulose can also be added in any intermediate stage of the polymerization. The invention is particularly suitable for Tieftemperaturpolymerisationen between 0 and 15 ⁰ C, since it is difficult to cool a pplymerisierten at high temperature approach for treatment with the Äthylhydroxyäthylcellulose before the unreacted monomers are separated. To the

The time of treatment with the ethyl hydroxyethyl cellulose does not have to be at least 5% in the latex converted, polymerizable monomer, based

209 619/448

based on the weight of the original synthetic rubber forming monomers otherwise the increase in particle size does not occur. The unreacted monomers,

amide; Vinyl pyridines such as 2-vinyl pyridine, 2-methyl-5-vinyl pyridine; Methyl vinyl ketone; Vinylidene chloride. Such a synthetic rubber latex can be used as a »synthetic rubber latex on butadiene

which together with the ethyl hydroxyethyl cellulose 5 polymer base «are designated. The latexes are present may consist of all of the dispersants contained in the polymerization stage remaining after the desired reaction, generally in amounts of from 2 to 10 weight of unreacted monomers, or only one percent of the solids of the latex, as a part thereof, if z. B. volatile mono-uniform or from a mixture of anionic mers, such as butadiene (1,3), from the latex before the surfactants existing dispersing additive of the ethylhydroxyethyl cellulose expelled medium. Such anionic surface-active dispersants have been made provided that at least 5% of the detergents can be water-soluble soaps of higher boiling monomers, e.g. B. styrene, for the monocarboxylic acids forming such. B. the treatment with the Äthylhydroxyathylcellulose alkali, ammonium or amine salts of higher remain, after which such higher boiling 15 molecular fatty acids, the 10 to 24 carbon monomers from the latex z. B. contained in the molecule by water vapor atoms, or by resin acids, can be driven off by distillation. The latex including hydrogenated, dehydrated and disproportionate will usually contain solids of ionized resin acids. The anionic surface-20 to 50% and can be sulfonated or concentrated in solids from 55 to 70% to an active dispersant content, 20 sulfated compounds, which of the general order a liquid latex with a high content of solids- Formula R - SO ₃ M or R - OSO3M correspond to the delivery of substances. The latex can by increasing where M is an alkali metal, the ammonium or the solids content in a known manner, an amine radical and R is an organic radical, e.g. B. by creaming by means of a plant mucilage of a group with 9 to 23 carbon atoms, such as ammonium alginate, can be concentrated. 25 contains means e.g. B. alkyl sulfonates such as dodecyl- It is preferred, however, that the solids content be sodium sulfonate; Alkyl sulfates, such as sodium oleyl

sulfate; Alkyl aryl sulfonates such as dodecyl benzene sulfonate; Alkyl sulfosuccinates such as sodium dioctyl sulfosuccinate; Aryl sulfonate formaldehyde condensation products, e.g. B. the condensation product Sodium naphthalene sulfonate and formaldehyde.

The following examples illustrate the invention. All parts and percentages relate to Parts by weight or percentages by weight.

example 1

In experiment A, a glass reaction vessel with a capacity of about 746 g was used The following mixture components are charged: 70 parts

to increase by concentrating evaporation. Unreacted monomers can come out of the latex be driven off by concentrating evaporation.

Ethylhydroxyäthylcellulosen are im. generally according to the viscosity in cP of a 2% aqueous Solution of ethyl hydroxyethyl cellulose in water at 20 ° C classified. Ethyl hydroxyethyl celluloses, as a 2% aqueous solution at 20.degree. C. have a viscosity of 15 to 600 cP Methods of the present invention can be used. However, they are ethyl hydroxyethyl celluloses of higher viscosity, the z. B. in 2% aqueous

Solution at 20 ° C has a viscosity of 600 cP- 40 butadiene (1.3), 30 parts styrene, 0.2 part sodium, not as effective as the preferably an- formaldehyde sulfoxylate, 0.15 part diisopropylbenzene Ethylhydroxyäthylcellulosen lower hydroperoxide, 0.015 parts ferrous sulfate heptahydrate, Viscosities in 2% aqueous solution at 0.03 part of the tetrasodium salt of ethylenediamine -20 ° C is 15 to 150 cP. tetraacetic acid, 4.0 parts of potassium oleate, 1 part of a

The synthetic rubber latex can be the polymer obtained in 45 by condensation of sodium naphthalenesulfo-aqueous emulsion of a dispersant or dispersant obtainable with formaldehyde, several butadienes (1,3), e.g. B. butadiene (1.3) 0.5 part of potassium sulfate, 0.03 part of sodium dithio itself, 2-methylbutadiene (l, 3) (= isoprene), 2,3-diene, 0.1 part of tert .-Dodecyl mercaptan and 100 parts of methylbutadiene (1,3), piperylene or mixtures of water. The mixture was mixed in the manner of one or more of these butadienes (1,3) with an _{upright drum mixer} at 5 ° C, or several other polymerizable compounds in this and in the other examples to form polymers with butadienes (1,3), e.g. B. tracked by periodic determination of the percentage content of up to 70 percent by weight of such a mixture of solids in the polymerization system, from one or more monoethylene compounds ₅₅ If the conversion reaches approximately the value of bonds which the group CH ₂ = C <ent- 42% A solution of at least one of the unbound 0.5 parts of the naphthalenesulfonate bound by condensation of sodium valences to an electronegative group with formaldehyde is obtainable, i.e. to a group which is the electrical dispersant and 50 parts Water added, symmetry or polar character of the molecule 60 The polymerization was allowed to increase considerably for a total of 6.5 hours. Examples of compounds, proceeding until a conversion of 89% which contains the CH ₂ = C <group and is reached with; The polymerization was then polymerizable by butadienes (1,3) are the addition of 0.2 parts of potassium-dimethyldithiocarb-arylolefins, such as styrene, vinyltoluene, α-methylstyrene, aminate, which were dissolved in 4 parts of water, sub-chlorostyrene , Dichlorostyrene, vinyl naphthalene; the 6 ₅ broke. Unreacted butadiene was driven off by α-methylenecarboxylic acids and their esters, nitriles and aeration. The average particle amides such as acrylic acid, methyl acrylate, methyl diameter of the latex was 870 angstrom methacrylate, acrylonitrile, methacrylonitrile, methacrylic units.

Test B was carried out in a similar way to test A, with the difference that during a conversion of approximately 49% 0.5 part of an ethyl hydroxyethyl cellulose, its 2% aqueous solution had a viscosity of about 20 cP at 20 ° C; and 0.5 part of one by condensation of sodium naphthalene sulfonate dispersant obtainable with formaldehyde and finally 50 parts of water were added. The polymerization was after a total time of 6.5 hours with a conversion of 90 ° / o. After an abortion of the unreacted butadiene by aeration was the average particle diameter of latex 1520 angstrom units.

Experiment C was carried out in a similar way to Experiment A, with the difference that during a conversion of approximately 40% 0.5 part of an ethyl hydroxyethyl cellulose, the 2% strength aqueous solution of which had a viscosity of about 100 cP at 20 ° C., 0.5 part of a solution obtained by condensation of sodium naphthalenesulfonate dispersant obtainable with formaldehyde and 50 parts of water were added. The polymerization was after a 6.5 hours total time interrupted at 77% conversion. After aborting the not butadiene reacted by venting was the average particle diameter of the latex 1760 angstrom units.

Example 2

In this example the following polymerization approach was used: 70 parts butadiene (1,3); 30 parts of styrene; 0.2 part of sodium formaldehyde sulfoxylate; 0.15 part of diisopropylbenzene hydroperoxide; 0.015 part ferrous sulfate _: heptahydrate; 0.03 part of the tetrasodium salt of ethylenediaminetetraacetic acid; 3.0 parts of potassium oleate; 0.5 part of a dispersant obtainable by condensation of sodium naphthalenesulfonate with formaldehyde; 0.75 part of potassium sulfate; 0.03 part sodium dithionite; 0.1 part of tert-dodecyl mercaptan; and 130 parts of water. The polymerization temperature was 5 ° C.

In experiment D, when the conversion had reached approximately 44%, 0.1 part of an ethyl hydroxyethyl cellulose, the 2% aqueous solution of which had a viscosity of about 20 cP at 20 ° C., furthermore 0.2 parts of a by condensation of Sodium naphthalene sulfonate with formaldehyde dispersant and 20 parts of water added. The polymerization was stopped as in Example 1 at a conversion of 85%. After the unreacted butadiene was driven off by venting, the average particle diameter was of latex 1300 angstrom units.

In experiment E, when the conversion had reached approximately 43%, 0.1 part of an ethyl hydroxyethyl cellulose, whose 2% solution in water had a viscosity of about 100 cP at 20 ° C, 0.2 part of a condensation of Sodium naphthalene sulfonate with formaldehyde dispersant and 20 parts of water added. The polymerization was stopped as in Example 1 at a conversion of 76%. After the unreacted butadiene was driven off by venting, the average particle diameter was of latex 1360 angstrom units.

In experiment F, when the conversion had reached approximately 31%, 0.5 part of an ethyl hydroxyethyl cellulose, whose 2% solution in water had a viscosity of about 600 cP at 20 ° C., and 20 parts of water were added. The polymerization was interrupted at 63% conversion as in Example 1. After aborting the not reacted butadiene, the average particle size of the latex was 1090 angstrom units.

The average particle size of the latex obtained in experiments D, E and F without the addition of ίο Ethylhydroxyäthylcellulose was produced, was between 500 and 600 angstrom units.

Example 3

In this example the following polymerization approach was used: 70 parts of butadiene (1,3); 30 parts of styrene; 0.2 part of sodium formaldehyde sulfoxylate; 0.15 part of diisopropylbenzene hydroperoxide; 0.015 part ferrous sulfate _: heptahydrate; 0.03 part of the tetrasodium salt of ethylenediaminetetraacetic acid; 4.0 parts potassium oleate; 1 part of a dispersant obtainable by condensation of sodium naphthalenesulfonate with formaldehyde; 0.5 part of potassium sulfate; 0.1 part of tert-dodecyl mercaptan; and 130 parts of water. The polymerization temperature was 5 ° C.

In Run G, when the conversion reached approximately 58%, 0.5 parts of a passed through Condensation of sodium naphthalenesulfonate with formaldehyde available dispersant and 30 parts of water were added. The polymerization was carried out at a conversion of 95% by the addition of 0.2 parts of potassium dithiocarbaminate, which were dissolved in 4 parts of water, interrupted. After an abortion of the unreacted butadiene by venting, the latex had an average Particle diameter of 600 angstrom units. Experiment G 'represents an identical repetition of the Experiment G, with the difference that the 0.5 parts of the condensation product at a Conversion of 52% were added and the polymerization at a conversion of 89% was interrupted. The average particle diameter of the latex was 580 angstrom units. The latices from experiments G and G 'were mixed and subjected to steam distillation, to drive off the remaining monomeric styrene, and then by concentrating evaporation in a laboratory disk concentrator at 45 to 50 ° C down to a solids content concentrated by 49%. The 49% solids latex had a viscosity of 2060 cP at approximately 25 ° C.

In the concurrent experiments H, when the conversions had reached approximately 59%,

0.5 parts of an ethyl hydroxyethyl cellulose whose 2% solution in water has a viscosity of about 2OcP at 20 ° C, 0.5 part of a by condensation of sodium naphthalene sulfonate with Formaldehyde available dispersant and 30 parts of water were added. The polymerizations were interrupted at a conversion of 92% as in Experiment G. After aborting the not reacted butadiene by aeration, the latices had an average particle diameter

S ₅ of 1600 angstrom units or 1640 angstrom units. The latexes from the concurrent experiments were mixed and then subjected to steam distillation to remove any unreacted

Expel styrene, and were then concentrated by means of Evaporate in a laboratory disk concentrator at 45 to 50 ° C down to one Concentrated solids content of 60%. The 60% solids latex had one Viscosity of 680 cP, measured at approximately 25 ° C.

In concurrent experiments J, when the conversions reached 86%, 0.5 parts of a Ethyl hydroxyethyl cellulose, the 2% solution of which in water has a viscosity of about 20 cP at 20 ° C had, 0.5 part of one obtainable by condensation of sodium naphthalenesulfonate with formaldehyde Dispersant and 30 parts of water along with 0.2 part of potassium dithiocarbaminate as a polymerization interrupter, dissolved in 4 parts of water, added. After aborting the not reacted butadiene by aeration, the latices had an average particle diameter of 1470 angstrom units or 1520 angstrom units on. The latices from the concurrent experiments were mixed and the steam distillation subjected to drive off unreacted styrene and then in a laboratory disk concentrator concentrated at 45 to 50 ° C to a solids content of 57%. The 57% solids latex had a viscosity of 640 cP, measured at approximately 25 ° C.

The latexes with the enlarged particle size according to the present invention, especially those with a high content of solids, can be used for the purposes customary for latices find, e.g. For the production of foam rubber, for the impregnation of tire cord by the dipping process, the gluing and impregnation of various materials, the production of Adhesives and the like.

It will be understood that many changes and modifications to what has been described will be apparent to those skilled in the art. Method possible without departing from the basic principles of the present invention.

Claims (1)

PATENT CLAIM: Process for the production of a synthetic rubber latex of increased particle size, characterized in that a rubber latex which has been obtained by polymerizing rubber-forming monomers in an aqueous emulsion and of at least 5% unreacted, polymerizable, monomeric material is obtained based on the weight of the monomers originally used, treated with 0.05 to 1 part by weight of ethylhydroxyethyl cellulose per 100 parts by weight of the monomers originally used at a temperature of 0 to 15 ° C and then removed the unreacted monomeric material from the latex. Considered publications:
U.S. Patent No. 2,702,285;
Ind. Eng. Chem., Vol. 49, pp. 364-368. © 209 619/448 7.62