DE1207075B - Stabilizer mixture for aqueous dispersions of polymers of 2-chlorobutadiene (1,3) or of copolymers of the same - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. CL:

Number:
File number:
Registration date:
Display day:

C08d

German KL: 39 b -4/01

1207 075
P26873IVd / 39b
March 30, 1961
December 16, 1965

Polychloroprene latices thicken as the temperature drops. Even at 10 ^° C. they have generally become so viscous that they can no longer be handled properly. This thickening is reversible, since the latex when heated slightly flows to about 24 ⁰ C and the latex properties are not affected adversely. If, however, the temperature drops to approximately 0 ^° C. and lower values, the latex can freeze. With such latices, this leads to breakage of the emulsion and coagulation of the polychloroprene solids. Up to now it has not been possible to recover such latices from the frozen form or to convert them back into an emulsion form.

It is true that commercial polychloroprene latexes are already freezing point by using conventional ones Antifreeze, e.g. B. methanol, decreased, but the latices are subject to freezing nevertheless irreversible coagulation. In addition, some conventional antifreeze agents affect the properties of the latex are disadvantageous.

These disadvantages are eliminated by the mixture to be used according to the claims.

The invention relates to the use of a mixture of

a) 10 to 20 parts by weight of methanol,

b) 0.5 to 4 parts by weight, calculated as casein, of a water-soluble casein salt and

c) 1 to 3 parts by weight of a nonionic surfactant

as a hardness-stabilizing additive to aqueous dispersions of polymers of 2-chlorobutadiene (l, 3) or of copolymers of the same with up to 60 percent by weight, based on the total monomer content, one or more copolymerizable monomers which form the terminal group

CH ₂ = Cc

The quantities of the stabilizer components are based on 100 parts by weight of polymer are.

"Polychloroprene latices" are to be understood as meaning latices which are made by conventional methods Chloroprene alone or with up to a total of 60 percent by weight, based on the total monomer content, one or more copolymerizable monomers have been prepared. To suitable Copolymerizable monomers include vinyl aromatic compounds, aliphatic conjugates Dienes, vinyl ethers, esters and ketones as well as esters, amides and nitriles of acrylic and methacrylic acid.

Stabilizer mixture for aqueous dispersions
of polymers of 2-chlorobutadiene (l, 3)
or of copolymers of the same

Applicant:

EI du Pont de Nemours and Company,
Wilmington, Del. (V. St. A.)

Representative:

Dr.-Ing. W. Abitz, patent attorney,

Munich 27, Pienzenauerstr. 28

Named as inventor:

Chester Herbert Gelbert, Radnor Green,

Claymont, Del. V. St. A.)

Claimed priority:

V. St. v. America March 31, 1960 (18 861)

The condensation products of 8 to 24 moles of ethylene oxide are used as nonionic surface-active agents with a long-chain fatty alcohol with 10 to 20 carbon atoms, an alkyl mercaptan with up to 20 carbon atoms or an alkylphenol whose alkyl group contains 8 to 18 carbon atoms, used. The alkyl groups of these compounds can be branched or unbranched. Examples suitable surface-active agents are condensation products of ethylene oxide with lauryl alcohol, Cetyl alcohol, oleyl alcohol, dodecyl mercaptan, tert-dodecyl mercaptan, isooctyl phenol and nonyl phenol. 10% strength aqueous solutions of the surface-active agent and 1 to 2 parts by weight of the are preferred surfactant, based on 100 parts by weight of polymer, used.

The water-soluble casein salts can be added by adding alkaline compounds Casein, such as ammonia, trisodium phosphate, borax, dimethylamine, diethylamine, Diethanolamine, sodium and potassium hydroxide. 10 to 15% solutions of the are preferred Casein salt used. The methanol is added in particular in an amount of 15 to 20 parts by weight, based on 100 parts by weight of polymer.

509 758/474

The addition of the stabilizer is expediently done in the form of an aqueous solution of 11.8 to Contains 63 parts of water. This is preferably done by mixing a 10% aqueous solution of the surfactant with a 10 to 15% aqueous solution of the casein salt and des Methanol produced. One can then add this using conventional mixing techniques add to the latex. You can also use the aqueous surfactant solution directly Add latex and then add an aqueous methanol-casein salt mixture.

The stabilizing additives according to the invention can also be added to latices, the conventional ones Mix components contain, z. B. zinc oxide, antioxidants and those commonly found in polychloroprene adhesives used resins. Latices stabilized according to the invention are particularly suitable for Adhesives.

The following examples serve to illustrate the invention. Parts and percentages relate to on weight.

Production of the casein solutions

1. Ammonium caseinate: 100 g of ammonium caseinate slowly boil to 900 g while stirring Water added. Stir until the casein has dissolved.

2. dimethylamine salt of casein: water is added 80 g of 40% strength aqueous dimethylamine to ^it 770 g of water which has been heated to 70 to 100 ° C. 150 g of dry casein are slowly added to the hot solution with stirring. Stir until the casein has dissolved.

3. Using a similar procedure as in the previous paragraph, other salts are added under Made using the following recipes: a) Casein 100

Borax, diethanolamine or trisodium phosphate 20

Water 880

b) Casein 100

Sodium or Potassium Hydroxide 5

Water 895

Example 1

To a 50% strength aqueous dispersion of polychloroprene ^s is added 1 part of these solutions, with stirring, to 100 parts of polymer:

A. B. C. D. Condensation product of
20 moles of ethylene oxide with
1 mole of cetyl alcohol
Dimethylamine salt of casein,
calculated as casein
Methanol 2
0.5
15th
20.8 2
0.5
20th
20.8 2
1
15th
23.6 2
1
20th
23.6 water

The samples are put into bottles and these are placed in a chamber kept at -15 ° C. Every sample is left in the chamber for 16 hours, then removed and left to stand for 8 hours at room temperature. This test treatment represents a "cycle". At the end of each of the 16-hour periods at -15 ° C each of the samples is frozen, but each sample takes in the 8 hour period at room temperature returns to its original emulsion form. The test is carried out for seven cycles and then canceled. At the end of the test, each of the samples is in the non-coagulated state.

Example 2

To a 50% strength aqueous dispersion of a copolymer of ^s 91.5 parts of chloroprene and 8.5 parts of 2,3-Dichlorbutadien- (l, 3) is added with stirring to 100 parts polymer, 1 part of solutions of the following table were added in accordance with, wherein the surfactant and casein salt of Example 1 can be used. The test is carried out according to example 1.

A. B. C. D. E. F. G H J K L. Surface active agent 1 1 1 1 1 1 ?, 2 ?, 2 ?, Casein salt 0.5
10 0.5
15th 0.5
20th 1
10 1
15th 1
20th 0.5
10 0.5
15th 0.5
? 0 1
15th 1 Methanol 11.8
W. 11.8
X 11.8
y 14.6
Z 14.6
X 14.6
y 20.8
X 20.8
X 20.8
y 23.6
X 70 water 23.6
y Results

w = The latex freezes and thaws in six cycles without coagulation and is coagulated after the seventh cycle.

χ = The latex freezes and thaws in seven cycles and is not coagulated at the end of the test.

y = The latex does not freeze in the seven cycles and is not coagulated at the end of the test.

ζ = The latex freezes and thaws in four cycles without coagulation occurring and is coagulated after the fifth cycle.

Even samples A and D, which contain only 10 parts of methanol and 1 part of the surfactant, remain uncoagulated after six or four cycles. This corresponds to a degree of freeze-thaw resistance, of all those usually occurring in the technical use of polychloroprene latices Conditions suffice.

Example 3

The latex used in Example 2 is mixed with 5 parts of zinc oxide and 2 parts of a 2,6-di-tert-butylp-phenylphenol and 50 parts of a terpene phenolic resin, based on 100 parts of polymer, mixed. 1 part of the following solution, based on 100 parts of polymer, is then added to this latex: using the surfactant and casein salt of Example 1:

6g surfactant 1

Casein salt 0.5

Methanol 20

Water 11.8

The test is carried out as in Example 1 with the modification that it is terminated after six cycles will. At the end of the test, all samples remained uncoagulated.

5 Example 4

Example 3 is repeated with the modification that instead of the surfactant des Example 1 1 part of the following surfactants used:

Condensation product of

a) 20 moles of ethylene oxide with 1 mole of oleyl alcohol (technical grade),

b) 10 to 11 moles of ethylene oxide with 1 mole of nonylphenol,

c) 8 to 10 moles of ethylene oxide with 1 mole of isooctylphenol,

d) 10 to 11 mol of ethylene oxide with 1 mol of tert-dodecyl mercaptan,

e) 24 moles of ethylene oxide with 1 mole of lauryl alcohol.

As in Example 1, the test extends to seven cycles. During the exam, all are subject to Samples in the seven cycles of freeze and thaw, remaining uncoagulated.

Example 5

The latex used in Example 3 is, based on 100 parts of polymer, 1 part of the following Solution added, working with the surface-active agent of Example 1:

Surface active agent

Casein salt, calculated as casein (s.

below)

Methanol

water

0.5
20th
13.5

20th
18th

35

40 The following casein salts are used:

Ammonium caseinate,

Casein salt, made by neutralization with

a) trisodium phosphate,

b) diethanolamine,

c) potassium hydroxide,

d) borax.

The test is carried out as in Example 1. All samples are after they have gone seven freeze-thaw cycles have been subjected, uncoagulated.

Claims (1)

Claim: Use a mixture of a) 10 to 20 parts by weight of methanol, b) 0.5 to 4 parts by weight, calculated as casein, of a water-soluble casein salt and c) 1 to 3 parts by weight of a nonionic surfactant as a cold-stabilizing additive to aqueous dispersions of polymers of 2-chlorobutadiene (l, 3) or of copolymers of the same with up to 60 percent by weight, based on the Total monomer content, one or more copolymerizable monomers which the terminal grouping CH ₂ = C- contain, the quantities of the stabilizer components based on 100 percent by weight Polymer are related. Considered publications:
U.S. Patent Nos. 2,018,313, 2,386,764. 509 758/474 12.65 © Bundesdruckerei Berlin