DE102005021993A1 - Preparation of crosslinking polymer with high double bond content, useful in the manufacture of varnish, resin and basic coating, comprises reaction of a reactant with a catalyst and an initiator - Google Patents

Abstract

Preparation of crosslinking polymer (I), with high double bond content and a viscosity of 300-10000 mPas, comprises reaction of a reactant with at least a catalyst and at least an initiator. Independent claims are included for: (1) a crosslinking polymer, with high double bond content, which is obtained from the process; and (2) a varnish comprising (I).

Description

The Invention relates to paint raw materials, UV curing of paints and resins for floor coatings and a process for their preparation, in particular binder with one possible high vapor pressure.

Distinguish macromolecules not only in the constitutive composition and the linking of the Basic building blocks, but also in the molecular architecture, i. through the Way in which the individual chains are linked together. One distinguishes unbranched chains, branched molecules, ordered ones and disordered networks. For branched molecules go from the branch points three or more chains out. There are many in disordered networks Polymer chains through intermolecular bonds to "infinite" large molecules without long-range orders connected (H.-G. Elias, macromolecules (5.) 1, p. 40). In networking reactions, many will still be soluble linear or branched macromolecules with each other to three-dimensional, insoluble and only swellable polymeric networks linked. Networking can be directly involved in the construction of the macromolecules, e.g. at radical Polymerizations using monomers with appropriate functionalities or in the case of polyadditions or polycondensations with participation of monomers with a functionality> 2, take place (Rompp-Lexikon Chemie, Georg Thieme Verlag, 9th ed. (1996), p. 4836).

polymethyl methacrylates become common from methacrylic acid produced by block, emulsion or suspension polymerization.

Under Polymethylmethacrylate plastics become homopolymers or copolymers from (meth) acrylates and optionally up to 20 wt .-% further with methyl methacrylate copolymerizable monomers, such as Styrene, understood. The notation (meth) acrylate means here both methacrylate, e.g. Methyl methacrylate, ethyl methacrylate etc., as well as acrylate, e.g. Methyl acrylate, ethyl acrylate, etc., as well as mixtures of both.

Preferably, the weight average molecular weight M _{w of} the matrix is in the range from 20,000 g / mol to 200,000 g / mol, in particular 30,000 g / mol to 150,000 g / mol (determination of M _w by gel permeation chromatography with reference to polymethyl methacrylate as calibration standard) , The molecular weight M _w can be determined, for example, by gel permeation chromatography or by a scattered light method (see, for example, BHF Mark et al., Encyclopedia of Polymer Science and Engineering, 2nd Edition, Vol. 10, pages 1 et seq., J. Wiley, 1989). ,

US-PS 4,526,945 (SCM Corporation) describes the cct (catalytic chain transfer) polymerization of methacrylate monomers in the presence an initiator and a cobalt (II) catalyst. The polymers have fairly low molecular weights of 2,300-88,300. Crosslinking Methacrylates are not produced by this method.

Under Binders are understood to mean polymers, oligomers or monomers, in a reaction in the applied paint film to the hard, solid Paint to be implemented. Binders can be functionalized polymers which are reacted in a reaction. The functional Groups of the functionalized oligomers can double bonds, isocyanate groups, Be epoxy groups or hydroxy compounds.

Highly volatile monomers as a binder to emissions of monomers into the environment, as monomers in general have a low vapor pressure. In the VOC directive is a MAK value for Methyl methacrylates (MMA) set. The replacement of volatile Monomers by low volatility Monomers, e.g. Lauryl methacrylate and stearyl methacrylate the disadvantage that the hardness and further mechanical properties of the paint film suffer.

dispersion coatings water-based and powder coatings meet these requirements but some application disadvantages that the need for Keep conventionally processable paints awake. With powder coatings can not the desired ones smooth surfaces getting produced. Only with high energy expenditure can that Water are removed from the dispersion coatings. Longer drying times are the consequence.

The functionalized oligomers or polymers should have the highest possible vapor pressure in order to minimize the emissions of volatile compounds when processing paints into the environment to keep ring.

When functional groups are preferred double bonds because the kinetics the occurring chain polymerization leads to shorter curing times.

Around Oligomers or polymers with double bonds as a functional group to get usually one or more hydroxyl groups or one or more glycidyl groups used. In a first reaction step, hydroxy or Glycidyl groups polymerized. In a second reaction will be these with methacrylic acid or methacrylic acid ester transesterified or esterified.

This 2-step process is very expensive.

It would be desirable the double bond functionality the methacrylate group in the oligomerization reaction in the resulting functionalized oligomer to incorporate itself the second reaction step to be able to save.

It the task was a process for the production of uncrosslinked Polymers or oligomers with high levels of functional double bonds to develop.

It also had the task of providing oligomers with low vapor pressure, for a good processability and good mechanical properties to ensure the paint.

Further the task was to differentiate into the polymers or oligomers Incorporate crosslinker types to adjust the mechanical properties. Crosslinkers become molecules (Monomers or oligomers) understood, the two or more to Reaction capable wear functional groups.

Examples for crosslinkers are ethylene glycol dimethacrylate (EGDMA), allyl methacrylate, triethylene glycol dimethacrylate, Allyl acrylate, vinyl (meth) acrylates, trimethylolpropane trimethacrylate, Tripropylene glycol diacrylate, trimethylolpropane dimethacrylate, trimethylolpropane triethoxytriacrylate, Glycerol trimethacrylate and butanediol dimethacrylate (BDDMA).

Under Polymers or oligomers with high crosslinker content become substances understood that up to 30 wt .-%, based on the polymer or oligomer, Containing crosslinker. Crosslinker groups are understood as meaning double bonds in particular, (meth) acrylates.

In spite of of high crosslinking content, the resulting polymers or Oligomers have a viscosity, which allows use as a paint binder.

Of the desired viscosity range is between about 300 mPas and 10,000 mPas (measured with a Brookfield viscometer).

The liquids should not contain gel particles.

Was solved the task by a process for the production of uncrosslinked Polymers having a high double bond content in the polymer, characterized in that that the starting materials with at least one catalyst and at least an initiator can be implemented in a process step and the viscosity range between 300 mPas and 10000 mPas, and the thus accessible Polymers or oligomers.

It shows that with the inventive method, the production unbranched polymers with high double bond content is possible.

Surprised was found to be highly branched with the method according to the invention molecules can be produced However, they do not lead to gel particles or specks in paints.

FIG. 1: Transfer mechanism for cocatalyzed systems:

following becomes a possibility for the preparation of the cobalt catalysts.

The Synthesis of the catalysts takes place in the glove box under Ar inert gas. The raw materials used are anhydrous, the ether is over one Na / K alloy dried.

The starting materials cobalt (II) acetate, dimethylglyoxime (DMG) or α-benzil dioxime (BD) and ether are mixed at room temperature. After some time, BF ₃ ethyl etherate is added by syringe. To complete the reaction, the mixture is stirred for a further 24 h at room temperature.

Of the The precipitate is filtered off with suction, washed with ether and in an oil pump vacuum dried. The catalyst is used without further purification.

Especially The monofunctional starting materials are preferably selected from the group of (meth) acrylates, preferably methyl methacrylate, methyl acrylate, Ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate, tert-butyl (meth) acrylate, Pentyl (meth) acrylate and 2-ethylhexyl (meth) acrylate; (Meth) acrylates, which is made up of unsaturated Derive alcohols, such as. Oleyl (meth) acrylate, 2-propynyl (meth) acrylate, Allyl (meth) acrylate, vinyl (meth) acrylate; Aryl (meth) acrylates, such as benzyl (meth) acrylate or phenyl (meth) acrylate, wherein the aryl radicals are each unsubstituted or may be substituted up to four times; Cycloalkyl (meth) acrylates, such as 3-vinylcyclohexyl (meth) acrylate, bornyl (meth) acrylate; Hydroxylalkyl (meth) acrylates, such as 3-hydroxypropyl (meth) acrylate, 3,4-dihydroxybutyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 1,4-butanediol (meth) acrylate, (meth) acrylates ether alcohols such as tetrahydrofurfuryl (meth) acrylate, vinyloxyethoxyethyl (meth) acrylate; Amides and nitriles of (meth) acrylic acid, such as N- (3-dimethylaminopropyl) (meth) acrylamide, N- (diethylphosphono) (meth) acrylamide, 1-methacryloylamido-2-methyl-2-propanol; sulfur-containing (meth) acrylates, such as ethylsulfinylethyl (meth) acrylate, 4-thiocyanatobutyl (meth) acrylate, ethylsulfonylethyl (meth) acrylate, Thiocyanatomethyl (meth) acrylate, methylsulfinylmethyl (meth) acrylate, bis ((meth) acryloyloxyethyl) sulfide; Lauryl (meth) acrylate, stearyl (meth) acrylate, isobutyl (meth) acrylate polyvalent (meth) acrylates, such as trimethyloylpropane tri (meth) acrylate and mixtures thereof in quantities of 60-99% by weight, preferably 70-95% by weight used.

It was found to be particularly good results through the process the use of bi- and / or trifunctional reactants supplies. The bi and trifunctional educts are preferably selected from the group of triethylene glycol di (meth) acrylates, trimethylopropane tri (meth) acrylates, Tripropylene glycol di (meth) acrylates, trimethylopropane di (meth) acrylates, Trimethylopropane triethoxytri (meth) acrylates, glycerol tri (meth) acrylates, Glycol di (meth) acrylates, ethyl glycol di (meth) acrylates or butanediol di (meth) acrylates as well as their mixtures. The bifunctional and trifunctional educts are in quantities of 1-40 Wt .-%, preferably from 5-30 Wt .-%, used.

The process can be carried out in a suitable solvent. Preferred solvents are selected from the group of the acetates, ketones particularly preferably ethyl acetate, butyl acetate, methyl ethyl ketone. Preference is given to using low-boiling solvents. Plasticizers may also be added as a solvent, preferably when the plasticizer can remain in the product. It is possible to use plasticizers known from the prior art, for example citrates, phthalates, adipates, phosphates etc., particularly preferably dioctyl phthalate, dibutyl phthalate. Likewise, Mi mixtures of plasticizers and low-boiling solvents.

It it was found that by selecting the crosslinker the product properties can be modified. For example, the mechanical properties are influenced. By the use of butanediol dimethacrylate (BDDMA) becomes a softer product produced.

It initiators are added to the polymerization reaction start. Azoinitiators are preferably used. Especially preferred Azoinitiators are selected from the group azoisobutyronitrile, dimethyl 2,2'-azobis-isobutyrate and 2,2'-azobis (2-methylbutyronitrile), as well as their mixtures. The initiators are used in amounts of 0.01-10% by weight. based on the polymer, preferably from 0.27 to 5 wt .-%, used.

Of the Branching degree is determined by the amount and type of catalysts controlled. Preference is given to catalysts from the group of Cobaltporphorphorine and cobalt glyoxime particularly preferably 5,10,15,20-tetrakis (4-methoxyphenyl) -21H-23H-porphorin cobalt (II), 2,3,7,8,12,13,17,18-octaethyl-21H, 23H-porphorin-cobalt (II) or cobalt (II) dimethylglyoxime borondifluoride, and mixtures thereof used. The catalysts are used in amounts of 1-10000 ppm, based on the polymer, preferably added from 100-1000 ppm.

The inventive method is characterized in that the solvent or solvent mixture submitted with initiator (mixtures) and catalyst (mixtures) and the monomer or monomers are added. In this case, the heat must over appropriate Heating and cooling devices to be controlled.

The preferred method according to the invention is characterized in that the starting material or the educts, catalyst if appropriate, catalyst mixtures and, if appropriate, solvents are initially introduced. Subsequently the initiator or the initiator mixture is added. The reaction is carried out at a temperature between 50 ° C and 180 ° C.

In a return device the monomers are presented. There are suitable solvents, preferably ethyl acetate. With commercially available initiators, preferably Azoisobutyronitrile, the reaction is started. By the crowd a suitable catalyst, the degree of branching is controlled. The catalyst used is preferably 5,10,15,20-tetrakis (4-methoxyphenyl) -21HI-23H-porphine cobalt (II) (Sigma-Aldrich, Seelze).

The Reaction mixture is filtered. There were no networked shares in the filter residue found. Subsequently becomes the solvent Concentrated in a rotary evaporator under vacuum. In the concentrated product No gel particles or specks are found. The product can in liquid or solid form.

The produced according to the invention Oligomeric and / or uncrosslinked polymers with high double bond content have a viscosity in the range of 300 mPas and 10000 mPas. Preferably, oligomers and / or uncrosslinked polymers having viscosities between 1000 and 5000 mPas produced. They are used for the production of coating raw materials, Paints, resins and floor coatings used. The paints of the invention are characterized by a particularly high vapor pressure. These Paints are preferred for environmental protection and occupational safety reasons.

The Examples given below are for better illustration of the present invention, but are not suitable to limit the invention to the features disclosed herein.

example 1

135 g of methyl methacrylate, 135 g of n-butyl methacrylate and 30 g of ethylene glycol dimethacrylate (crosslinker) are placed in an 11-jacketed reflux apparatus. The solvent used is 302 g of ethyl acetate, 2 g of azoisobutyronitrile serve as initiator. The reaction temperature is 70 ° C. 108.6 g of the monomer mixture are added during the first minute, then the residual amounts are added dropwise over 52 min. The catalyst used is 5,10,15,20-tetrakis (4-methoxyphenyl) -21HI-23H-porphine cobalt (II) (Sig ma-Aldrich, Seelze).

The Post-reaction time is 240 min. The reaction mixture is filtered. There were no networked Proportions in the filter residue found subsequently becomes the solvent Concentrated in a rotary evaporator under vacuum.

A product with an M _w of 1100 g / mol and D = 1.4 (polymerization index) is obtained. The solids content before concentration is 35.8%. The viscosity is 1540 mPas.

Example 2

In an 11-jacketed Rücklußapparatur 127.5 g of methyl methacrylate, 127.5 g of n-butyl methacrylate and 45 g of ethylene glycol dimethacrylate (crosslinker) submitted. As a solvent Serve 302 g of ethyl acetate, as an initiator serve 2 g of azoisobutyronitrile. The reaction temperature is 70 ° C. 110.9 g of the monomer mixture are during added the first minute, then the remaining amounts over 50 min dropwise. The catalyst used is 5,10,15,20-tetrakis (4-methoxyphenyl) -21HI-23H-porphine cobalt (II) (Sigma-Aldrich, Seelze).

The Post-reaction time is 240 min. The reaction mixture is filtered. There were no networked Proportions in the filter residue found. Subsequently becomes the solvent Concentrated in a rotary evaporator under vacuum.

A product with an M _w of 1560 g / mol and D = 1.7 is obtained. The solids content before concentration is 37.4%. The viscosity is 2180 mPas.

Example 3

In a double-jacket reactor with reflux cooling, 135 g of methyl methacrylate, 135 g of n-butyl methacrylate, 30 g of ethylene glycol dimethacrylate (crosslinker) and 0.36 g Tetrakismethoxyphenylporphin (catalyst) are placed in 205 g of butyl acetate. The experiment is carried out under a nitrogen atmosphere. With stirring (150 min ^-1 ), the mixture is heated to 94 ° C. 1.5 g of azoisobutyronitrile in 97 g of butyl acetate are added slowly over 3 hours.

The Post-reaction time is 1.5 hours. The reaction mixture is filtered. There were none crosslinked portions in the filter residue found. Subsequently becomes the solvent Concentrated in a rotary evaporator under vacuum.

A product with an M _w of 1,600 g / mol and D = 1.7 is obtained. The solids content before concentration is 47.8%. The viscosity is 2100 mPas.

Example 4

142.5 g of methyl methacrylate, 142.5 g of n-butyl methacrylate, 15 g of ethylene glycol dimethacrylate (crosslinker) and 0.36 g of tetrakis methoxyphenylporphin (catalyst) in 205 g of butyl acetate are placed in a jacketed reactor with reflux cooling. The experiment is carried out under a nitrogen atmosphere. While stirring (150 min ^-1 ), the mixture is heated to 95 ° C. 1.5 g of azoisobutyronitrile in 97 g of butyl acetate are added slowly over 3 hours.

The Post-reaction time is 1.5 hours. The reaction mixture is filtered. There were none crosslinked portions in the filter residue found. Subsequently becomes the solvent Concentrated in a rotary evaporator under vacuum.

A product with an M _w of 1,400 g / mol and D = 1.8 is obtained. The solids content before concentration is 45.1%. The viscosity is 1960 mPas.

Claims (12)

Process for the preparation of uncrosslinked polymers having a high double bond content in the polymer, characterized in that the starting materials are reacted with at least one catalyst and at least one initiator in one process step and the viscosity range is between 300 mPas and 10000 mPas. Process for the preparation of uncrosslinked polymers high double bond content in the polymer according to claim 1, characterized in that that bifunctional and / or trifunctional starting materials are used. Process for the preparation of uncrosslinked polymers high double bond content in the polymer according to claim 2, characterized in that that the bifunctional and trifunctional starting materials are selected from the group of Triethylene glycol di (meth) acrylates, trimethylopropane tri (meth) acrylates, Tripropylene glycol di (meth) acrylates, trimethylopropane di (meth) acrylates, Trimethylopropane triethoxytri (meth) acrylates, glycerol tri (meth) acrylates, Glycol di (meth) acrylates, ethyl glycol di (meth) acrylates or butanediol di (meth) acrylates and their mixtures are used in amounts of 1-40 wt .-%. Process for the preparation of uncrosslinked polymers high double bond content in the polymer according to claims 1-3, characterized that the monofunctional starting materials are selected from the group of (Meth) acrylates, preferably methyl (meth) acrylate, ethyl (meth) acrylate, Butyl (meth) acrylate, allyl (meth) acrylate, benzyl (meth) acrylate or Phenyl (meth) acrylate and / or vinyl (meth) acrylate and mixtures thereof in amounts between 60-99 % By weight. Process for the preparation of uncrosslinked polymers high double bond content in the polymer according to claims 1-4, characterized in that that solvent be used. Process for the preparation of uncrosslinked polymers having a high double bond content in the polymer according to claims 1-5, characterized that the starting materials, the catalyst and optionally solvent submitted and the initiator are added. Process for the preparation of uncrosslinked polymers with high double bond content in the polymer according to claims 1-5, characterized in that that the initiators are selected are from the group of azo initiators, preferably azoisobutyronitrile, Dimethyl-2,2'-azobis isobutyrate and 2,2'-azobis (2-methylbutyronitrile), as well as their mixtures. Process for the preparation of uncrosslinked polymers with high double bond content in the polymer according to claims 1-6, characterized in that that catalysts from the group of Cobaltporphorphorine and Cobaltglyoxime particularly preferably 5,10,15,20-tetrakis (4-methoxyphenyl) -21H-23H-porphorin cobalt (II), 2,3,7,8,12,13,17,18-octaethyl-21H, 23H-porphorin-cobalt (II) or cobalt (II) dimethylglyoximbordifluoride, and mixtures thereof be used. Process for the preparation of uncrosslinked polymers high double bond content in the polymer according to claims 1-8, characterized in that that temperatures between 50 ° C and 180 ° C be set for implementation. Uncrosslinked polymers with high double bond content in the polymer, available according to a method according to claim 1. Use of uncrosslinked polymers with high double bond content in the polymer according to claim 10 for the production of paints, varnish raw materials, resins and floor coatings. Lacquer with uncrosslinked polymers with a high double bond content in the polymer, available according to a method according to claim 1.