DE2355419A1 - HIGH SOLID CHLOROPRENE LATEX - Google Patents

Description

The invention relates to a process for the production of chloroprene polymer latices or latices of chloroprene polymers with a high solids content by a direct polymerization process. Chloroprene polymers are made by an emulsion polymerization process which normally provides a low total solids latex. However, high solids chloroprene polymer latexes are required for many applications. Z ₀ B. are latexes with a high solids content in the application for foam production, impregnation,
for spraying and for connecting
Fibers desired. It is desirable for latices of this type to have a total solids content of at least 50%, and preferably at least 55 or about 57%. Heretofore, it has been common practice to make high solids latices by concentrating low solids latices. These processes include agglomeration processes such as agglomeration by solvent addition, partial soap neutralization, electrolytic neutralization, freezing, mechanical means,

40S82Q / 086S.

(creaming) addition of hydrophilic solids, creaming / and evaporation.

Prior art methods of concentrating synthetic latices are described in Chapter 5 of "High Polymer Latices", Volume 1 by D.C. Blackley (Palmerton, 1966). In this The multiple problems encountered with making a high solids latex by a direct book will address the multiple problems encountered Polymerization processes are connected, described. One of the Problems associated with the production of high solids latices are that both during polymerization as well as considerable stability problems arise during the storage of the latices. Another problem that comes with Associated with these processes is the excessive viscosity during and after polymerization. The usual procedure for The manufacture of high solids chloroprene latexes made use of the technique of creaming as disclosed in U.S. Patent 2,450,724. In an effort to overcome the difficulties of making chloroprene polymer latexes directly with high Overcoming solids content have been various methods as described in U.S. Patents 3,651,037 and 3,651,038. However, those in these patents The method described furthermore has considerable disadvantages, in particular with regard to the peak viscosity and the stability of the latex during polymerization and also with regard to the stability of the latex during storage. A The aim of the invention is therefore to produce a chloroprene latex with a high solids content by a direct polymerization technique, which brings less stability and viscosity problems during the polymerization, and also a latex produce, which has a high storage stability. Another goal is to produce a polymer that has improved physical properties such as tensile strength, and which has excellent properties in terms of physical application and use.

According to the invention, chloroprene latexes with a high solids content, which contain at least 50% by weight of solids, can be prepared by polymerizing chloroprene, which contains up to 25 % by weight of another ethylenically unsaturated organic monomer,

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■ which is copolymerizable with chloroprene, contains, thereby be made that one

1) the polymerization with less than the total amount of the monomer initiated in an aqueous emulsion containing salts of

a) 0.15 to 1.0 parts of a fatty acid ingredient which is a fatty acid, polymerized fatty acid, or mixture it can be

b) 0.30 to 4.0 parts of a formaldehyde condensate Naphthalenesulfonic acid and

c) 1.4 to 4.0 parts of a rosin ingredient (rosin member), which the different rosins (various rosins), modified rosin or polymerized Can be rosin,

2) the aqueous emulsion until the viscosity of the polymerization mixture reaches a peak and at least begins to decrease, polymerizes

3) the remaining monomer is added and the polymerization continues to produce a chloroprene polymer latex with at least 50% by weight solids to produce, wherein

4) the parts by weight of a), b) and c) are based on 100 parts of the Obtain monomers introduced up to the time of initial peak viscosity.

One of the major obstacles to producing a high solids latex by the direct polymerization technique is that during the polymerization there occurs a portion or a period at which the viscosity reaches a peak value, at which point the polymer tends to coagulate or agglomerate and deposit on the reactor stirrer and surfaces. This high viscosity also leads to problems in terms of mixing us of heat transfer. In addition, the polymerization tends. '

409820/0885 ^:

mix to form flakes. According to the invention it has surprisingly been found that if a particular combination of salts are introduced into the reaction mixture in certain proportions, as indicated above, and if, in addition, less than the total amount of the monomer is initially present, these stability problems during the polymerization are considerably reduced. It has also surprisingly been found that the latices obtained have improved storage stability and excellent physical properties. It has been found that the composition of the reaction mixture is critical during the period of peak viscosity and that improved stability results can be obtained by using the particular combination according to the invention. It is preferred to control the peak viscosity to no more than 300 centipoise as measured with a Brookfield Mr. 2 spindle at 45 ⁰ C ₃ au. At lower final latex solids ₉ such as 55% solids, the peak viscosity should preferably be no greater than 225 centipoise.

According to the invention, polymers of chloroprene, 2-chloro-1,3-butadiene, are polymerized with the formation of latices with a high solids content. The term "polymer of chloroprene" encompasses polymers in which chloroprene is ISFC present as major or predominant monomer _o Ss can also be Comonoinere .Used such as 2,3-Dicnior- »l ₀ 3-buiadien Acrylnl _p-tri 1 ₉ Methyl methacrylate, etc.,

In general, the total amount of ethylenic is sown. The term comonomers are not more than 25 mole percent of the total monomers, and preferably less than 15 or 20 mole percent of the total monoase, including chloroprene. The Polymerization of Chloroprene In ^ Sweet Emulsion 1st.alIge. my well-known, and any such system, which does not affect the new properties of the present invention, can be used as well as methods for the polymerization and extraction and isolation of chloroprene sB ·. '■■

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in "Encyclopedia of Polymer Science and Technology", Volume 3, Pages 705 to 730 (Interscience, 1965) and in numerous patents, such as the ÜS-PS 2 264 '173 and 2 264 191 described.

The polymerization mixture should contain a salt of 0.15 to 1.0 part of a fatty acid component selected from the group consisting of fatty acids, polymerized fatty acids and mixtures thereof per 100 parts of the monomer present during the time of peak viscosity. The fatty acid ingredients can be saturated or unsaturated carboxylic acids having 12-30 carbon atoms, or they can be products made by the dimerization or trimerization of the unsaturated fatty acids. The fatty acids are acyclic, aliphatic, polyunsaturated carboxylic acids. Fatty acids such as lauric acid, stearic acid, eicosanoic acid, oleic acid, linoleic acid and dimers and trimers of unsaturated fatty acids such as linoleic acid may be mentioned. Of the unpolymerized fatty acids, those having 16 to 18 carbon atoms are preferred, with oleic acid being a particularly preferred fatty acid. Of the polymerized unsaturated fatty acids, those of monomers having 16 to 18 carbon atoms, such as polymers of linoleic acid, are preferred. In general, these polymers will be mixtures of dimeric and trimeric materials. An example of a linoleic acid polymer is a polymer that contains about 75% of the dimer, about 22 % of the trimer, and about 3% of the monomer. Suitable polymerized unsaturated fatty acids are described in US Pat. No. 2,876,203. The best results were obtained with the polymerized unsaturated fatty acids. About 0.15 to 1.0 part of the fatty acid component can be used, with a preferred range of 0.4 to 0.8 parts. based on the monomer introduced up to the time of the initial peak viscosity. The percentages are calculated based on the weight of the fatty acid component and not the salt.

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.- D -

The second essential surfactant is a salt of a rosin xura ingredient. The rosin ingredient can be any of various rosins, such as gum rosin, wood rosin [including, for example, Nancy wood rosin and the N variety] or tall oil rosins, or the modified or polymerized rosins (modified rosins.or polymerized rosins). These rosin ingredients can be of natural or synthetic origin. The modification can be carried out by hydrogenation, polymerization or disproportionation and combinations thereof. The suitable rosins are those in which resin acids are present and which have been used as emulsifiers in polychloroprene polymerizations. Rosins and rosins derivatives are described in "Encyclopedia of Polymer Science ¹ ', Volume 12, pages 139-156 (Interscience, 1970). Although a variety of rosins can be used, certain rosins are superior and constitute a preferred embodiment of the Wood rosins give polymers with good stability, but the preferred type is the disproportionated rosins as prepared by hydrogenation and dehydrogenation of the unsaturated components 2,154,629 and 2,201 237. Disproportionate rosins, such as those of the 731 series or the 731 series, are available from Hercules, Inc. The amount of rosin component should be in the range of 1.4 to 4.0 and preferably between 1.8 and 3.0 parts per 100 parts of up to time d he initial peak viscosity of the monomers introduced.

The third essential surfactant is that Salts of the condensation products of naphthalenesulfonic acids and formaldehyde, as described in US Pat. Nos. 1,336,759 and 2,046,75 and 2,264,173 as well as in "High Polymer Latices", Volume 1

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from. Blackley, pp. 103-105 (1966) (which hereinafter sometimes referred to as "condensation product" for the sake of simplicity) "The condensation product should be in an amount of iron 0.30 to 4.0 parts and preferably, from 2.0 to 3.0 parts per 100 parts of up to date the peak viscosity-introduced monomers be present.

The fatty acid component j rosin component and the condensation product are at least partially or essentially completely converted into the salt either before or during the polymerization. Thus, dps salt can be added as such or formed in situ. The compounds are salts of alkali metals or of ammonia. Because of the better stability and solubility of the salts of potassium should be ₉ sodium or ammonium salts, and according to a preferred embodiment of the invention, at least 50% of the cations potassium ions.

There were excellent results obtained ₉ when the combined total amount of rosin and fatty acid component in the range of I ₉ B to 2.5 parts by weight per 100 parts of lay of the total used before completion of the polymerization monomers, and preferably the same relationship exists _s based on the monomer which was introduced up to the time of the initial peak viscosity. Further, excellent results have been obtained when the ratio of the colophotilum component to the fatty acid component at the time of the peak viscosity is at least 2 ₉ Ö. It has been found that obtained su an optimum stability, the fatty acid component preferably in an amount of at least O ₉ 30 parts by weight per t © 0 parts of the up-to the introduced time of the initial peak viscosity mono-, kidney be present

Other surface-active agents can also be present, to support the polymerization stability the. new properties, three-essential, surface-active Medium does not run ^! Ilt * fsHtigeno Example * for surface

active agents useful in chloroprene polymerization are described in U.S. Patent 2,264,173.

The usual methods can be used to prepare an aqueous emulsion of monomeric material, emulsifier and. Produce water. The ratio of water to monomer is adjusted to the final high solids latex to surrender. Usually about 55 to 95 parts of water will be present per 100 parts of that before and during peak viscosity Monomers charged - of course, the amount of water depends on the proportion of the total monomer, which before the addition of the monomer according to the peak viscosity is present vary.

According to the invention, less than the total amount of the monomer is present in the reactor during the period of the initial peak viscosity. The exact percentage of monomer present can vary somewhat depending, for example, on the particular combination of surfactants used. However, in general, the monomer present during this initial peak viscosity will be 40 to 90 or 95 percent of the total monomer, with a preferred range being between about 60 and 90 percent of the total monomer. This initial monomer can be introduced into the reactor prior to initiation of the polymerization, or it can be partly charged and partly charged so long as only the required amount is present during the initial peak viscosity. In general, all of the first batch of monomer will be introduced prior to initiation to ensure adequate monomer availability for the formation of large polymer particles. After the initial peak viscosity has been reached, the additional monomer can be added all at once or in portions, or it can be fed continuously or semi-continuously. The additional. Monomers can be added as such or, for example, as an emulsion, such as using the salts described above as emulsion stabilizers.

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are given. Regarding the time of addition of the monomer should be approached with some insight. For example, the viscosity of the reaction mixture should be checked before adding the Monomers decay to some extent in order to obtain the maximum benefit of the invention. The in. The present Description and the amount mentioned in the claims of the monomer introduced up to the point in time of the peak viscosity includes any initial batch of monomers plus all monomers which was added up to the time of peak viscosity.

It was found that the addition of the monomer after the peak viscosity is preferably carried out over a period of time rather than adding the monomer all at once. Through a Doing so will facilitate temperature control and agitation during the reaction. Normally The addition of monomers takes place over a period of at least 15 minutes and possibly for at least 30 minutes. After this Feature it takes at least 15 minutes to add the monomer after the initial peak viscosity. It was found that in some cases an advantageous one increased stirring during and after the addition of monomers can be used.

It is known to use monomers during a chloroprene polymerization to be added, but with different polymerization processes and to produce polymers of different types, as described in US Pat. No. 3,472,828.

The _pH value of the aqueous emulsion for polymerization may vary depending upon the particular emulsification system employed, and it may be acidic, neutral or alkaline to be; however, a p n in the range from about 7 to 13.5 is preferred.

Usual catalysts for chloroprene polymerization can be used can be used and preferred catalysts are peroxide catalysts of the organic or inorganic type.

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Examples of organic peroxides are benzoyl peroxide, cumene hydroperoxide, tert-butylisopropylbenzene hydroperoxide, azo catalysts such as α, α ¹ -azo-bis-isobutyronitrile and the like. Suitable inorganic peroxides are those such as inorganic peracids including persulfates, perborates or. Percarbonates, such as ammonium or potassium persulfate and hydrogen peroxide. The catalyst can be used in any desired proportion in the desired amounts to bring about the polymerization, with suitable amounts ranging from 0.001 to 0.5 parts by weight per 100 parts of the polymerizable monomer.

Modifying agents or other agents can be present in the emulsion. For example, the polymerization in the presence of Sulfur can be carried to a sulfur modified Manufacture polychloroprene. Chain transfer agents such as dialkyl xanthogen sulfides can also be used and the dialkylxanthogen disulfides, alkyl mercaptans, e.g. dodecyl mercaptan, Iodoform and benzyl chloride.

The degree of polymerization and the properties of the polymer can be controlled in a known manner. Both the production of benzene-soluble and benzene-insoluble polymers is within the scope of the present invention. The extent of conversion of the monomer can vary, but it has been found that superior products are obtained when the degree of conversion is at least 90 or 95% by weight. Superior products are made, e.g., with greater tensile strength, if essentially not stripped Monomer, e.g., less than 3% of the total monomer, is present at the end of the run. Conversions of at least 98% are preferred.

The polymerization temperature can vary depending on the nature of the particular polymer used, with the most appropriate Temperature in the range from 0 to 90 C and preferably in the range from 15 to 55 C. The polymerization can through

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Addition of agents such as p-tert-butylcatechol and thiodiphenylamine can be interrupted, but it is preferred according to the invention not to interrupt the polymerization but to allow it to run until high conversions are reached. The polymerization may · extraction process either "be continuous, or it ^can: be also carried out batchwise, whereby the batchwise polymerization is generally in the erfindungsgeniäBen method is suitable ..-." -

Means to increase stability during the - ■; For example, sulfates, the various rosins or modified rosins (various rosins or modified rosins), can be added: fatty acids, polymerized fatty acids and salts, such as sodium, potassium or ammonium salts, these compounds, diethanolamine or others known latex stabilizers are added to the latex after the polymerization.

The latices according to the invention can after the polymerization, to obtain the high solids latex before Use partially or fully cured or vulcanized e.g. by reaction with mono- or polyamines with 1 up to 8 or "10 carbon atoms including the amines of U.S. Patent 3,686,156..

Examples :. * "·· -

In order to illustrate the invention, a number of examples were carried out. All of these examples were carried out in a ^r 5! , 25% potassium persulfate, 0.05% silver salt (sodium 2-anthraquinone sulfonate) and 99.7% water were added until the total monomer had reached a conversion of 80 % , at which point the pumped catalyst mixture of 4.5 % potassium persulfate, 0.1 % silver salt and 95.4 % water

409020/0865 - .

Polymerization was controlled to achieve a conversion of about 95% after 6 hours with the final percent conversion being about 99.5 % after about an additional 4 hours. "Viscosities were measured with a Brookfield # 1 or # 1 spindle 2 (No. 1 for viscosities below 100 cebtipoise) at 60 IJpM and measured during the approach at polymerization temperature, while all other viscosities were measured at 25 ° C. The initial peak viscosity during the polymerization was at Visually determined point of maximum viscosity measured. In general, this peak occurs about 2 hours after the start of the polymerization. No post-polymerization stabilizers were added to these batches. Unless otherwise stated, all parts are by weight. In the case of surfactants or additives the parts on the surfactants as received from the manufacturer.

The stability observations are based on optical perception, except in the cases where ivo numbers are given. The percentage of the coagulate in the reactor is determined by that you filter the latex through a muslin cloth (cheese cloth) of double strength, the percentage for the coagulate is based on the weight of the monomers introduced.

"The following examples are intended to explain the invention further, but without restricting them.

Examples 1 to 4

A number of approaches have been taken to explain the difficulties encountered with the prior art method Technique of introducing all of the monomers before peak viscosity occurs. Examples 1 to 4 illustrate these recipes. Examples 1 to 4 use a constant amount of the condensation product (Daxad 11 ICLS). The amount of polymerized fatty acid (Empol 1022) will endeavor that

suppress and the

- ¹³ -

Flake formation -during the approach -i
Stability, to improve, varies. In these runs, the rosin surfactants (Resin 731-SA = Resin 731-SA) are also varied in an effort to control peak viscosity and stability during the run.

example

Chloroprene resin 731-SA

1)

Diisopropylxanthogen disulfide

water

Potassium hydroxide Daxad 11 KLS ² * Empol 1022 ³⁾

Brookfield Peak Viscosity (cP)

Final solids content (%). Final viscosity (cP) ⁴⁾

Stability observations Flocculation after 2 hours

Coagulate in the reactor flocculates after 24 hours. Flaking after 1 week

100.00 100.00 100.00 100.00 1.80 1.00 0.90 1.67 0.30 0.30 0.30 0.30 ■; so so 60.50 60.50 60.50 1.30 1.30 1.30 1.30 2.00 2.00 2.00 2.00 0.18. 1.00 0.90 0.33 145.0 460.0 3 85.0 187.0 60.9 59.1 59.8 60.3 71.0 193.0 252.0 61.0 small amount
docile
slight
moderate none
^ «0.2%
none
slight none
none
slight small amount
docile
none
slight
moderate

Disproportionate wood rosin obtained from Hercules, Inc. with a minimum specific rotation of 60 °, an acid number of 137-145, a minimum of 48 % dehydroabietic acid and a maximum of 1.9 im UV absorption spectrum at 245 mp . Resin 731-SA is a 731-S disproportionated wood rosin treated with soda ash. About 1.8 parts is equivalent to 1.76 parts of the free acid rosin.

The material used is "Daxad 11 KLS" from VJ.R.Grace and Co. This is a potassium salt of the condensate of formaldehyde and alkylnaphthalenesulfonic acid. It is in the presence of stable to weak acids and alkalis, has practically no tendency to foam and has a p "value (1% solution at 22.2 ° C) from 7 to 8.5. The parts refer to the material as received from the manufacturer.

Essentially a C_g dibasic acid as the product of the polymerization of linoleic acid. The dimer content is about 75%, the trimer content about 22% and the monomer content about 3%. It is commercially available under the name "Empol 1022" by the Available from Emery Industries, Inc.

In order to conclusively compare final viscosities, they should be taken below Using a solids versus viscosity curve fitted be o

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Examples 5 to 7

Further comparative approaches were made to those associated with the prior art polymerization process Difficulties to illustrate. In the endeavor, the difficulties, the high peak viscosity and the poor stability To overcome, Examples 5, 6 and 7 were carried out.

Example 5 6

Chloroprene 100.00 100, OO 100.00 Resin 731-SA 1.86 1.86 1.86 Diisopropylxanthogen disulfide 0.30 0.30 0.30 water 6O, 5O 6O, 5O 6O, 5O Potassium hydroxide l, 3O l, 3O l, 3O Daxad 11 KLS '2.00 0.30 0.60 Empol 1022 0.14 O, 14th 0.14 Brookfield Peak Viscosity (cP) 67.5 265.0 235.0 Final solids content (%) 59.0 59.4 60.4 Final viscosity (cP) 38.0 54, O 63.0 Stability observations
Flocculation after 2 hours
Coagulate in the reactor
Flocculation after 24 hours
Flaking after 1 week slightly
none
moderate
moderate slightly
none
moderate
moderate slight
none
slight
moderate

According to Example 5, the peak viscosity is controlled, but is the polymer obtained was relatively poor in terms of flaking after 2 and 24 hours and after 1 week. In example 6, in an effort to reduce flocculation, reduced the condensation product to 0.30. However, this approach has one high peak viscosity and flaking occurs during polymerization and aging, so the results are not significantly better than those of Example 5. By changing the amount of the condensation product was according to Example 7, a further attempt was made to achieve stability together with low peak viscosity. Even though If the peak viscosity was decreased somewhat, flocculation still occurs.

Examples 8 to

The method according to the invention is described in Examples 8, 9 and. illustrated. Example 4 is a comparative approach and is identical with the example above

example

Chloroprene 100.00 66.66 66.66 83.32 first chloroprene increment - 16.6 7 16.67 16.68 second chloroprene increment ■ - 16.67 16.67 Resin 731-SA 1.6 7 1 _S 67 ¹ ' 1.86 ^4; 1 _S 86 ⁶⁾ Diisopropylxanthogen disulfide 0.30 0.30 0.30 0.30 water 60.50 60.50 60.50 60.50 Potassium hydroxide 1.30 1.30 1 ₉ 3O l, 3O Daxad 11 KLS 2.00 2.00 ² * 2.00 ²⁾ 2, OO ⁷⁾ Empol 1022 0.33 0.33 ³ > 0.14 ⁵⁾ $ 0.14 Brookfield peak viscosity
(Centipoise) original batch 187.0 27.5 19.0 42.5 after the last mono
mer admission " 320.0 140.5 9O, O Final solids content (%) 60.3 61.9 60.5 59.9 Final Viscosity (Centipoise) 61.0 135.0 78.0 59.0 Stability observations
Flocculation after 2 hours «,
Coagulate in the reactor
Flocculation after 24 hours «,
Flaking after 1 week slight
none
low
moderate none
none
none '
low slight
none
moderate
moderate none
none
slight
slight

Corresponds to 2.5 parts based on that during peak viscosity present monomers »

Corresponds to 3.0 parts, based on the monomer present during the peak viscosity » Corresponds to 0.50 parts, based on the monomer present during the peak viscosity.,

Corresponds to 2.8 parts, based on the monomer _{or the like present during the peak viscosity}

Corresponds to 0.21 parts, based on the

sitat present monomers »,

Corresponds to 2.2 parts based on that during peak viscosity "present monomers"

Corresponds to 2.4 parts, based on the monomer present during peak viscosity.

Corresponds to 0.17 parts, based on the. During the peak viscosity, sitat present monomers _o "

. ' - 409820/0865

In Example 4, all of the monomer was added all at once. In Examples 8 and 9, 66.66% was introduced at the beginning, and after the peak viscosity had been reached the first increment of 16.67 % was added. Then the second increment was added. In the case of Example IO, 83.32 % was initially introduced and the remaining monomer was added after the peak viscosity. In each of these Examples 8, 9 and 10, after each monomer addition, the polymerization was allowed to proceed to 80% conversion before the addition of the monomer increment. The final conversion is about * 99.5% by weight, based on the total monomer introduced. According to example 8 a low peak viscosity of 27.5 compared to 187.0 of example 4 is obtained. The latex of Example 8 is stable during polymerization and storage. Example 9 has an excellent peak viscosity of 19.0, but because of the small amount of polymerized fatty acid it is on the limit in terms of stability. According to the example, a low peak viscosity with good stability is achieved. According to Example 8, the peak viscosity after the last monomer addition is 320, which can be described as high, but this approach demonstrates that high viscosities can be tolerated in the late course of the polymerization. It should be noted that good latex stability is achieved, although high in the late course of the polymerization

Peak viscosity is present. ⁺ 'of the monomer

Example 11

Example 11 illustrates a preferred embodiment of the present invention in which the three salts are controlled within a preferred range.In this approach, the monomer is added to peak viscosity in a single increment and after the first monomer has reached 80% conversion. admitted. The first peak viscosity is 120, which is low enough to achieve control of the reactor temperature and the stirring during the preparation. "Although the peak viscosity after the last monomer addition is 325, the viscosity in the poly

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merization not particularly harmful at this point. the The final viscosity of the latex is 117.5, which is absolutely suitable for the end product. The stability of the final latex is excellent, with no flocculation and no coagulum observed in the reactor.

Example 11

Starting chloroprene batch 83.32

Chloroprene increment 16.68

Resin 731-SA 1.86

Diisopropylxanthogen disulfide O, 30

Water 60.50

Potassium hydroxide 1.30

Daxad 11 KLS '2.00

Empol 1022 0.50 Brookfield peak viscosity (centipoise)

original batch 120.0

after addition of the monomer _ 325.0

Final solids content (% ■) ■ 61.0

Final viscosity (centipoise) 117.5

Stability observations

No flaking after 2 hours

No coagulate in the reactor

No flaking after 24 hours

No flaking after 1 week

In order to illustrate the physical properties of the latices produced by the process according to the invention,
a comparison with commercially available high latices
Solids content carried out by the Du Pont and BAYER companies.
All of these tests were evaluated in a standard china clay formulation as follows.

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Component dry weight basis

Latex ΙΟΟ, Ο

Dixie clay 10.0

Antioxidant 2246

[2,2'-methylene-bis- (4-me-

ethyl 6-tert-butylphenoD] 2.0

Zinc oxide. 5.0

Sodium dibutyldithiocarbamate 1.0

Tetraethylthiuram disulfide 1.0

The compounding ingredients are made by grinding using prepared as dispersions in a ball mill with suitable stabilizers and added to the latex with stirring. Films produced in the dipping process are made from the latex by that a glass template is first immersed in a solution of a coagulating agent, secondly, immersed in the compounded latex and thirdly in a solution of a coagulant. The films are washed and, for measurement, test pieces are cut, leached for 2 hours at 40 C and in dried in an air oven at 45 ° C for 4 hours to obtain uncured products. Hardening was done in an air oven ' at 140 C for 30 minutes. The formulations obtained had the values given in the table below Modulus, tensile strength and elongation.

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Comparison of physical. Properties of latex with high levels of pesticides

characteristic O tensile strenght ■ Curing time
¹ (min.) At 140 ° C Bayer
CMKB
#1 . . Bayer
CMKB
# 2 Du Pont
ECD-2931
#1 Du Pont
ECD-2931
# 2 at
game, 11 Module at 300 % CO ■
σ> 1 % Elongation O _{> -} 130 · ■ · ■■ · 115 95 ° module at 600% 5 ___ 175 - ■ - 175 . 295 ο 15th 200 195 270 OD 30th 205 180 280 ■ - ■ 45 ■ _ - 205 ___ 190 295 cn 0 370 365 440 225 200 5 470 425 770 490 800 15th 500 550 840 495 945 30th 485 565 860 535 1075 45 490 615 860 555 1080 0 2010 2035 2515 1830 1305 5 2375 2560 2600 3395 3950 15th 2680 3400 3105 3750 4230 30th 2955 3975 3245 3815 4175 45 3555 3745 3200 3730 4340 0 1100 1300 1100 1550 1500 5 1100 1100 900 950 910 '· 15 UOO 1025 850 925 840 30th 1050 - 1050 '875 900 825 45 1050 1000 885; · ■ 925 825

-2G-

The tensile strength values of the latex produced according to the invention indicate that, in comparison to the latex from Du Pont or the company BAYER a stronger film is obtained and that a rapid hardening takes place, i.e. after 5 minutes the tensile strength was considerably higher than that of the other materials, although the fourth for the uncured product was lower than that of the other samples. The latex according to the invention has has a low initial modulus, and the modulus increases significantly more than that of the Du Pont or BAYER samples.

Example 12

The procedure of Example 11 was repeated except that oleic acid was used in place of the polymerized linoleic acid and wood rosin of the quality N [N grade wood rosin (product of Heyden-Newport Chem.)] were used instead of the resin 731-SA in equal parts by weight. It became a high solids latex made with good stability.

Example 13

The procedure of Example 11 was repeated with the exception that 1.3 parts of a 50/50 mixture by weight of sodium hydroxide and potassium hydroxide were used in place of potassium hydroxide.

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Claims (4)

A process for the production of latices with a high solids content containing more than 50% by weight of solids, characterized in that monomers are polymerized which comprise chloroprene which contains up to 25% by weight of another ethylenically unsaturated organic monomer copolymerizable with chloroprene, whereby 1) initiates the polymerization in an aqueous emulsion being less than that, total monomers and Salts of cations selected from the group consisting of alkali metals, ammonia, and mixtures thereof a) 0.15 to 1.0 parts of a fatty acid component selected from the group consisting of fatty acids, polymerized fatty acids and mixtures "thereof, b) 0.30 to 4.0 parts of a formaldehyde condensate of a naphthalenesulfonic acid and c) 1.4 to 4.0 parts of a rosin ingredient selected from the group consisting of rosins (rosins), modified rosins and polymerized rosins (polymerized rosins) contains, 2) the aqueous emulsion is polymerized until the viscosity of the polymerization mixture has a peak viscosity reaches and at least begins to decline, 3) .the remaining monomer is added and the polymer " rization is continued to form a chloroprene polymer latex having a solids content greater than 50% by weight, whereby 4) the parts by weight of a) based on the weight of the fatty acid component The parts by weight of b) are based on the weight of the salt, calculated as salt and the parts by weight of c) are based on the weight of 409820/0 8 65 Rosin constituent, where all weights of a), b) and c) are based on 100 parts of the monomer, which is added up to the point of peak viscosity; was related. 2.) The method according to claim 1, characterized in that the salts are selected from the group consisting of Sodium, potassium and ammonium salts and mixtures thereof. 3.) Method according to claim 2, characterized in that the salts are at least 50% by weight of potassium soaps. 4.) The method according to claim 1, characterized in that the chloroprene polymer latex with a solids content of greater than 50% by weight as latex is used without isolating the chloroprene polymer solids prior to use. 5.) The method according to claim 1, characterized in that the chloroprene polymer latex before use as a latex is partially vulcanized. 6.) The method according to claim 1, characterized in that the high solids latex has a solids content of at least 55% by weight. 7.) The method according to claim 1, characterized in that the viscosity of the polymerization mixture at the peak viscosity before the addition of the monomer is not more than 300 centipoise Brookfield viscosity as measured with a # 2 spindle at 45 ° C. 8.) The method according to claim 1, characterized in that the viscosity of the high solids latex at the end of the polymerization not more than 300 centipoise Brookfield viscosity, measured with a spindle no. 2, at 25 ° C. 409820/0865 9.) The method according to claim 1, characterized in that the fatty acid is a polymerized fatty acid. 10.) The method according to claim 1, characterized in that. the rosin constituent part is a modified rosin 11.) The method according to claim 1, characterized in that the rosin component is a disproportionated rosin is. 12.) The method according to claim 1, characterized in that the total combined amount of the rosin component and the fatty acid component. 1.5 to 2.5 parts by weight per 100 parts of the total monomer used before the completion of the polymerization. 13.) The method according to claim 1, characterized in that the ratio of the rosin component to the fatty acid component at the time of the initial peak viscosity of 2) is at least 2.0. 14.) Method according to claim 1, characterized in that the amount of the fatty acid component is at least 0.30 parts by weight per 100 parts of that at the time of the initial Peak viscosity of 2) monomers present is. 15.) The method according to claim 1, characterized in that the weight percentage conversion at the time of the end of the polymerization is at least 95% of the total monomer present during the polymerization. 16.) The method according to claim!, Characterized in that the salts at the time of peak polymerization a) 0.4 to 0.8 parts of the Fefctsäurebeilteils, b) 2.0 to 3.0 parts of Formaldehydkpndenpats and c) 1.8 up to 3.0 parts of the Ko-. lophonium constituents, with all parts älif • 100 parts of the Jfcmo present during the peak viscosity . "'" ■. ■ iÖ9 $ 2Ö / 086S refer to meren. 17.) Method according to claim 1, characterized in that the stirring speed in the polymerization reactor increases during the addition of the monomer according to the peak viscosity will. 18 «,) Method according to claim 1, characterized in that Dialkyl xanthogen sulfide as a polymerization modifier is used. 19.) The method according to claim 1, characterized in that ' the high solids latex was made with essentially no stripping of the monomer at the end of the polymerization will. 20.) The method according to claim 1, characterized in that the monomer which the reaction up to the time of initial peak viscosity is added, 40 to 95% by weight of the total monomer added during the polymerization. 21.) Process for making high solids latices with a content of at least about 57% by weight solids, characterized in that one polymerizes monomers, the chloroprene, which up to 25% by weight of one contains other ethylenically unsaturated organic monomers copolymerizable with chloroprene, whereby 1) the polymerization is initiated in an aqueous emulsion containing about 60 to 90 % of the total "monomers and salts of cations selected from the group consisting of sodium, potassium, ammonia and mixtures thereof, at least 50% by weight being potassium, from a) 0.4 to 0.8 parts of a polymerized fatty acid, . b) 2 to 3 parts of a formaldehyde condensate of a naphthalenesulfonic acid and 409820/0865 c) 1.8 to 3 parts of a disproportionate wood rosin contains, 2) the aqueous emulsion is polymerized until the Vis -'_ ,. viscosity of the polymerization mixture a peak viscosity ity is reached and at least begins to decline, 3) the remaining monomer is added and the polymerization is continued to produce a chloroprene polymer latex with a solids content of at least about To obtain 57% by weight,
whereby 4) the parts by weight of a) based on the weight of the polymerized Fatty acid, the parts by weight of b) relate to the weight of the salt, calculated as salt, the parts by weight of c) are based on the weight of the disproportionate Wood rosin, where all weights of a), b) and c) refer to 1Ö0 parts of up to Refer to the time of the peak viscosity introduced monomers. 0 9 8 2 0/0865