DE2400923A1 - PROCESS FOR THE PREPARATION OF DISPERSIONS IN ORGANIC LIQUIDS - Google Patents

Description

D 650

2A00923

Dr. Th.

VIANOVA KUNSTOARZ AKTIENGESELLSCHAFT, A 1010 Vienna I. , Johannesgasse 14

Process for the preparation of dispersions in organic liquids.

The invention relates to a method for producing dispersions synthetic film-forming polymer in an organic liquid.

It is known to prepare dispersions in a non-aqueous medium, by placing monomers or their mixtures in inert organic liquids in the presence of amphipathic Macromolecules polymerized. Amphipathic molecules are understood to have one component of the organic Liquid is strongly solvated while the other with associated with the dispersed polymer particles. These compounds serve as external stabilizers in non-aqueous dispersions.

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Dispersions, which are stabilized with the help of araphipathic macromolecules, usually require a high proportion of aromatic or ester-like solvents, which are used as solvents in the preparation of the stabilizers and thereby introduced into the dispersion. But if you want the presence of these mostly highly toxic organic substances Avoid liquids, they must be removed before the dispersion is made, which means a considerable amount of energy and workload is connected.

Another undesirable property of the stabilizers mentioned lies in the fact that for the production of their segments which can be solvated in aliphatic hydrocarbons Long-chain monomers are used, which in many cases are derivatives of stearic acid or other fatty acids with similar Are chain lengths, and the waxy properties of the stabilizers that result from this, which result in the Adversely affect the quality of the coatings produced from the dispersions.

It has now been found that these deficiencies can be eliminated by using α, β-ethylenically unsaturated monomers in the presence of a copolymerizable polymer, which for Mainly consists of p-tert-butylstyrene, polymerized, taking advantage of the fact that p-tert-butylstyrene is a has unlimited aliphatic solubility and compatibility and is made of polymeric p-tert.-butylstyrene films characterized by high light transmission and excellent gloss.

The present invention relates to a process for the preparation of dispersions containing hydroxyl groups Copolymers in organic liquids is marked that one

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A) 10-30% by weight _; preferably 15-25% by weight of a copoly-

merizable polymer, which is a reaction product made of

1) a low molecular weight copolymer of 80-94% by weight p-tert-butyl styrene and 4-12% by weight glydicyl methacrylate and

2) 2-8% by weight (meth) acrylic acid and / or (meth) acrylic acid chloride, where the sum of 1) and 2) is 100%, with

B) 70-90% by weight, preferably 75-85% by weight, copolymerized

cash ethylenically unsaturated monomers, at least one of which has a functional hydroxyl group,

copolymerized in one or more straight-chain and / or branched aliphatic hydrocarbons with boiling ranges between 60 and 210 ° C., preferably white spirit, in which component A is completely soluble and the dispersed copolymer of A and B is largely insoluble.

The dispersions according to the invention! have a number of advantages over dispersions based on amphipathic macromolecules. In particular, they are distinguished by the fact that they are largely harmless with regard to the organic liquids contained therein, since both the preparation of the copolymerizable polymer A and that of the dispersion are carried out exclusively in aliphatic hydrocarbons (preferably those with a boiling range of 145 200 ^° C.) .

Moreover, in the case of the dispersions whose polymer particles are dispersed with the aid of external stabilizers, the Stabilized by intermolecular forces, they are dipole-dipole interactions or hydrogen bonds between the polymer-compatible anchor part in the amphipathic macromolecule and the dispersed particles takes place, substantial temperature sensitivity. A temperature increase z. B. during the preparation of the dispersion leads directly to a reduction in the binding force between the stabilizer and

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Polymer particles, causing deteriorated stability and increased coagulum formation takes place.

The dispersions according to the invention are, however real copolymers which self-stabilized due to the covalently built-in, petrol-solvatable p-tert-butylstyrene chains represent non-aqueous polymer dispersions. The stability is not achieved by secondary forces. The possibility increasing the reaction temperature affects both on the conversion as in a shortening of the reaction time and also allows the incorporation of unreactive monomers.

The copolymerizable polymer A is produced in two stages. A low molecular weight copolymer of - in the first stage is at about 140 ⁰ C using high Regleriuengen - up to 2%, based on the monomers used. 80-94% by weight of p-tert-butylstyrene and 4-12% by weight of glycidyl methacrylate in an aliphatic hydrocarbon mixture such as white spirit, which in the 2nd stage introduces polymerizable double bonds with 2 - 8% (meth) acrylic acid and / or (meth) acrylic acid chloride is modified at 120 ° C. The polymer A is produced as an approx. 50% solution.

The dispersions according to the invention can according to the customary Methods are made:

10-30% by weight, preferably 15-25% by weight, of polymer A

be with

70-90% by weight, preferably 75-85% by weight, of component B mixed and part, d. see about 5-10% by weight of the mixture in the organic liquid. The one in the reaction vessel Any air present is displaced by inert gas and the batch is brought to the reaction temperature. The rest of the monomer mixture and initiators and, if appropriate, regulators are then slowly added in the customary manner.

Suitable ethylenically unsaturated monomers with the

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Polymer A can be copolymerized are the following: Methyl (meth) acrylate, ethyl (meth) acrylate ,. Propyl (meth) acrylate. Butyl (meth) acrylate, hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, Hydroxybutyl (meth) acrylate, tripropylene glycol mono (meth) a.crylate, (Meth) acrylic acid, styrene, p-tert. -Butylstyrene, vinyltoluene.

The copolymer dispersions according to the invention are complete Can be produced without leaving any residue and are characterized by their complete freedom from coagulate and specks, which means time-consuming filtration measures can be saved. They can be produced with a solids content of up to over 50% by weight and have excellent stability and resistance to external influences.

The dispersions obtained flow already at room temperature

,. ^ ^, τ.,. ·, Aittinoplast resins

door. Sxe deliver,. ... in a known way with / pigments, soluble dyes, crosslinking agents, plasticizers and the like and briefly at higher temperatures baked ", coatings with excellent properties which, for example, as topcoats meet all consumer requirements satisfy.

As aliphatic hydrocarbons are used in the following Examples used:

Boiling range ⁰ C aniline point Kauri aromatic

⁰ C approx. Butanol content value approx. Vol% white spirit A 145 - 200 56 39 white spirit B 184 - 207 85 26 0

The invention is illustrated by the following examples in which all parts are based on weight *

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Example 1:

A polymer A based on p-tert-butylstyrene / glycidyl methacrylate / methacrylic acid with copolymerizable double bonds is prepared in the following manner. 190 parts of p-tert-butyl styrene; 10 parts of glycidyl methacrylate, 120 parts of white spirit A, 4 parts of di-tert-butyl peroxide and 4 parts of tert. Dodecyl mercaptan are placed in a feed vessel equipped with a stirrer, reflux condenser and a thermometer equipped reaction vessel and heated to 140 ° C. A mixture of 380 parts of p-tert-butylstyrene, 20 parts of glycidyl methacrylate, 240 parts of white spirit A, 8 parts of di-tert. Butyl peroxide and 8 parts of tert. Dodecyl mercaptan is added dropwise over a period of 2 hours and the batch is stirred for a further 2 hours, while maintaining the temperature. The temperature is then lowered to 120 ° C., a mixture of 0.2 parts Hydroquinone, 1 part of dimethylbenzylamine and 50 parts of white spirit A were added, followed by 13.2 parts of methacrylic acid over the course of one hour and 250 parts of white spirit A are added. The reaction mixture is stirred at 120 ° C. for a further 3 hours. the solution obtained has a solids content of 50%.

A dispersion is prepared by adding 14.7 parts of this solution together with 18 parts of methyl methacrylate, 12 parts of styrene, 3.6 parts of ethyl acrylate, 6 parts of hydroxybutyl acrylate, 0.36 parts of bisazoisobutyronitrile and 601.3 parts of white spirit B to the above-described Reaction vessel are introduced. The batch is gäialten under an N ^ atmosphere for 20 minutes at 90 ° C, whereupon in the course of one hour a mixture of 230 parts of the polymer A solution, 244.8 parts of methyl methacrylate, 163.2 parts of styrene, 56.4 parts of ethyl acrylate, 84 parts of hydroxybutyl acrylate, 12 parts of acrylic acid and 5.64 parts of azobisisobutyronitrile are added and the temperature is maintained for a further hour. A stable, residue-free and speck-free dispersion with a solids content of 48% and a viscosity of 13.4 s is obtained in a No. 4 Ford cup at 20.degree.

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Example 2:

7.85 parts of the polymer Α solution from Example 1 are introduced with 6 parts of methyl methacrylate, 10 parts of ethyl acrylate, 0.16 parts of azobisisobutyronitrile and 284 parts of white spirit B into a reaction vessel equipped with a stirrer, reflux condenser, feed vessel and thermometer and below N _Q atmosphere held at 90 ° C for 20 minutes. A mixture of 128.1 parts of polymer A solution, 81.6 parts of methyl methacrylate, 154.4 parts of ethyl acrylate, 80 parts of tripropylene glycol monomethacrylate, 6 parts of acrylic acid and 3.68 parts of azobisisobutyronitrile is then added over the course of one hour, and the temperature is one held at 90 ° C. for a further hour. This gives a very stable, rückstände- and speck-free dispersion having 52.9% solids content and a viscosity of 140 seconds in a Ford cup no. 4 at 20 ⁰ C.

Example 3:

4.8 parts of the polymer Α solution from Example 1 are mixed with 6 parts of methyl methacrylate, 4 parts of p-tert-butylstyrene, 1.2 parts of ethyl acrylate. 2 parts of hydroxybutyl acrylate, 0.1 part of azobisisobutyronitrile and 198.6 parts of white spirit A are introduced into the device according to Example 2 and kept for 20 minutes at 90 ^° _{C. under an N 0 atmosphere} Parts of polymer A solution, 81 parts of methyl methacrylate, 54.4 parts of p-tert-butylstyrene, 18.4 parts of ethyl acrylate, 28 parts of hydroxybutyl acrylate, 4 parts of acrylic acid and 1.9 parts of azobisisobutyronitrile are added and the temperature is at 90 ° for a further hour kept C. This gives a very stable, without residue and speck-free dispersion having 49.8% solids content and a viscosity of 47.3 seconds in a Ford cup no. 4 / at 20 ⁰ C.

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Example 4:

A polymer A based on p-tert-butylstyrene / glycidyl methacrylate / acrylic acid chloride with copolymerizable double bonds is prepared in the following manner. 90 parts of p-tert-butyl styrene, 10 parts of glycidyl methacrylate, 60 parts of white spirit A, 2 parts of di-tert-butyl peroxide, 2 parts of tert. Dodecyl mercaptan are introduced into the apparatus of Example 1 and heated to 140.degree. A mixture of 180 parts of p-tert-butyl styrene, 20 parts of glycidyl methacrylate, 120 parts of white spirit A, 4 parts of di-tert-butyl peroxide and 4 parts of tert. Dodecyl mercaptan is added dropwise over a period of 2 hours and the mixture is stirred for an additional 2 hours while maintaining the temperature. Subsequently, the temperature is lowered to 120 ⁰ C, a mixture of 0.2 parts of hydroquinone, 1.2 parts Dioctylhexylamin and 90 parts of mineral spirit A was added and in the course of one hour, 19.8 parts of acrylic acid chloride and 30 parts of mineral spirits A are added. The reaction mixture is ^{stirred at 120 °} C. for a further 3 hours. The solution obtained has a solids content of 51%.

A dispersion is prepared by introducing 0.7 part of this solution together with 3 parts of styrene, 5 parts of methyl methacrylate, 0.06 part of azobisisobutyronitrile and 113 parts of white spirit A into the reaction vessel described in Example 1. The batch is kept under an atmosphere for 20 minutes at 90 ° C., whereupon a mixture of 22.1 parts of the polymer solution, 32 parts of styrene, 30 parts of methyl methacrylate, 30 parts of hydroxylbutyl acrylate and 0.94 part of azobisisobutyronitrile is added and the temperature is maintained for an additional hour. This gives a residue-free dispersion having 46% solids content and a viscosity of 29.2 seconds in a Ford cup no. 4 at 20 ⁰ C.

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Example 5:

50 parts of the dispersion from Example 2 are mixed with 17.5 parts of a benzoguanamine resin (of the Viamin BG 542 type) Addition of 0.16 parts of p-toluenesulfonic acid mixed. That The resulting mixture is applied (by conventional methods) to glass or sheet metal and baked at 130 ° C. for 30 minutes. You get a hard, clear, scratch-resistant and excellent against solvents such as xylene or acetone permanent (heat-hardened) coating.

Viamin BG 542 is a non-plasticized partially with butanol Etherified benzoguanamine-formaldehyde condensate with high reactivity. Viscosity 6 - 10 P / 20 ° C, 70% in butanol.

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Claims (2)

Claim: 2400923 1. Process for the preparation of dispersions of HydroxyIgrup-. pen-containing copolymers in organic liquids in combination with amino resins as binders for thermosetting coating agents, characterized in that A) 10-30% by weight, preferably 15-25% by weight of a copoly- merizable polymer, which is a reaction product made of 1) a low molecular weight copolymer 80-94% by weight of p-tert-eutylstyrene and 4-12% by weight glycidyl methacrylate and 2) 2 - 8% by weight (meth) acrylic acid and / or (meth) acrylic acid chloride, where the sum of 1) and 2) is 100%, B) 70-90% by weight, preferably 75-85% by weight copolymer sizable ethylenically unsaturated monomers, at least one of which is one has functional hydroxyl group, in one or more straight-chain and / or branched aliphatic hydrocarbons with boiling ranges between 60 and 210 ° C, preferably white spirit, in which component A is completely soluble and the dispersed one Copolymer of A and B is largely insoluble, copolymerized. 409834/0709