DE102004015182A1 - Use of N-methylcaprolactam - Google Patents

Abstract

Use of N-methylcaprolactam as a solvent, diluent, extractant, cleaning agent, degreaser, absorber and / or dispersing agent, in particular as a partial or total replacement of N-methyl-2-pyrrolidone (NMP), chlorinated hydrocarbons and / or ethers.

Description

The The present invention relates to uses of N-methylcaprolactam (N-methyl-epsilon-caprolactam, CAS-No. 2556-73-2), especially in certain procedures.

When a highly polar, aprotic and widely applicable organic solvent low viscosity, which is homogeneously miscible with water and other organic solvents is N-methyl-pyrrolidone (NMP) in research and engineering established.

By way of example, the following publications relating to NMP may be mentioned here:
WC Walsh, M. Waldrop and R. Atkins, "A Process to Vacuum Vapor Degrease Metal Parts with N-Methyl Pyrrolidone", 1997, CA Abstract No. 127: 7688.
The booklet "Formulating Paint Strippers with N-Methylpyrrolidone", BASF Corporation, Chemical Intermediates, 1990, USA,
and the following 17 publications of BASF Corporation, Chemicals Division, USA:
WC Walsh, "Removal of Rosin and Resin Based Solder Flux from electronic Assemblies with N-methylpyrrolidone / water mixtures",
WC Walsh, "Degreasing and Solvent Regeneration in Metal Parts, Cleaning using N-Methylpyrrolidone", eg: http://es.epa.gov/p2pubs/oaic/301.html.
WC Walsh, "Surface Tension Modification of NMP-based Paint Strippers",
WC Walsh, "N-Methyl Pyrrolidone (NMP Technical Tips), Removal of Paints and Coatings from NMP Soluble Plastics",
Walsh, WC (1991), "Surface Tension Modification of NMP-based Paint Strippers". In: Reducing Risk in Paint Stripping, Washington DC, 12-13 February 1991, pp. 177-184. Economics and Technology Division; Office of Toxic Substances; United States Environmental Protection Agency, Washington DC, 1991,
WC Walsh, "N-Methyl Pyrrolidone (NMP Technical Tips), Maintenance Cleaning Aircraft Ball Bearing Assemblies",
WC Walsh, "N-Methyl Pyrrolidone (NMP Technical Tips); Cleaning of a Chlorinated Paraffin / Metal Stearate Based Compound Drawing Off of 1000 Ft. Long Coils of 0.25", 316 Stainless Steel Tubing ",
WC Walsh, "N-Methyl Pyrrolidone (NMP Technical Tips), Chemical Warfare Resistant Coatings (CARC), Removal From Metal Surfaces",
WC Walsh, W. Monahan and M. Waldrop, "Reflux Cleaning of Large Reactors with N-Methyl Pyrrolidone (NMP)",
WC Walsh, "Replacement of MEK with N-Methyl Pyrrolidone (NMP) in Coatings Plant Resin Clean Up Operations",
WC Walsh, "N-Methyl Pyrrolidone (NMP) Technical Tips, Removal of POLYU-RETHANE / POLYUREA RESIDUE from the Interior Surfaces of a Batch Reactor Vessel",
WC Walsh, "N-Methyl Pyrrolidones - Cleaning Applications in the Urethane Manufacturing and Processing Industries",
MW Waldrop and WC Walsh, "Modification of a Vapor Degreasing Machine for Immersion Cleaning using N-Methyl Pyrrolidone",
WC Walsh, "Removal of N-Methyl Pyrrolidone From Metal Parts Using A Centrifugal Dryer",
WC Walsh, M. Waldrop and R. Atkins, "A Process to Vacuum Vapor Degrease Metal Parts with N-Methyl Pyrrolidone", http://es.epa.gov/techpubs/3/15413.html,
WC Walsh, RT Chwalik, KE Hinzman and M. Waldrop, "Removal of N-Methyl Pyrrolidone (NMP) from Industrial Plant Exhaust Air with a Packed Column Scrubber", and
WC Walsh, "N-Methyl Pyrrolidone (NMP Technical Tips), Reclaiming or Recycling of NMP", and others
"Electrical Insulation - From Wire Enamel to Enamelled Wire", 1 Beck Information, July 1992, (Beck Electrical Insulation Systems, Hamburg).

Of the present invention is based on the object of a replacement for NMP and also to find chlorinated hydrocarbons and / or ethers, at least approximately, preferably equally good, in particular also improved properties in the applications in which these substances, in particular NMP, are used.

This Replacement for NMP should also be similar physical Properties, e.g. concerning viscosity, colorlessness, polarity, inertness, Biodegradability, homogeneous miscibility with other organic solvents and water. The replacement should be even more favorable have toxicological properties, i. even less toxic be, as NMP.

According to the invention was recognized that N-methylcaprolactam such a replacement for NMP and also chlorinated hydrocarbons and / or ether.

Accordingly, became the use of N-methylcaprolactam as a solvent, diluent, Extractants, detergents, degreasers, absorbents and / or dispersants found.

N-methylcaprolactam is a slow-evaporating (vapor pressure: 2.2 Torr / 67 ° C), highly polar, aprotic, and widely applicable organic Solvent (boiling point: 106-108 ° C / 6 mm Hg) with favorable ecological data (see safety data sheet for N-methylcaprolactam from Sigma-Aldrich Chemie GmbH, Germany, product number 224766, 2 / 2004-4 / 2004).

It is a colorless, low-viscosity liquid with a weak amine odor. N-methylcaprolactam is with water and most organic solvents Completely miscible.

Of Further, N-methylcaprolactam has favorable toxicological data on. (See safety data sheet for N-methylcaprolactam from Sigma-Aldrich Chemie GmbH, Germany, product no. 224766, 2 / 2004-4 / 2004).

Compared with conventional solvents, N-methylcaprolactam has some salient features:
It is recyclable and non-corrosive, has a high flash point, a high ignition temperature (218 ° F, 103 ° C) and a low surface tension, dissolves inorganic substances such as inorganic salts, separates aromatic from aliphatic compounds and is very readily biodegradable.

Examples for such Inorganic substances are: sulfur, zinc chloride, sodium nitrite, Sodium bromide, mercuric chloride, some iron, copper and lead salts.

All listed above Features make N-methylcaprolactam a good or a best choice for one wide range of different applications (see below).

N-ethyl-pyrrolidone is the lactam of 5-methylaminocaproic acid and a very weak one Base. N-methylcaprolactam is a chemically stable and powerful polar Solvent. These properties are in different chemical reactions, where an inert medium is of importance, very valuable:

Reaction medium for the organic synthesis

in the Compared to other solvents carries N-methylcaprolactam when used as a solvent often desirable in chemical reactions catalytic effects and results in better sales. This advantageous property is great Importance.

Alkylation of Acetylidene

The Production of acetylides under mild conditions is possible in N-methylcaprolactam, whereas for these products generally include an alkylation of acetylenes in liquefied Ammonia is required [vgl. for example: GE 944 311 (BASF, 1956)].

Reppe Chemistry

From Advantage is N-methylcaprolactam also as a reaction medium, the one better processing history for which provides ethynylation and vinylation under Reppe conditions [Comp. for example: W. Chodkiewicz, Ann. de Chim. (Paris), 2 (13), 819 (1957); GE 940,981 (BASF, 1956)].

Synthesis of nitriles

By the use of N-methylcaprolactam as a solvent in Rosenmund-von-Braun nitrile synthesis the yield is improved and the reaction time is shortened; furthermore all reactants dissolved, so that a homogeneous liquid Phase yields [comp. for example: M.S. Newman and D.K. Philipps, J. Am. Chem. Soc. 81, 3667 (1959)].

Reactions of synthesis gas in N-methylcaprolactam

Carboxylic acids, carboxylic anhydrides and carboxylic acid esters can be prepared by reacting alcohols with synthesis gas (CO + H ₂ ) using nickel or cobalt complexes in N-methylcaprolactam.

One Another method is the production of ethylene glycol from synthesis gas. By combining a rhodium carbonyl species and N-methylcaprolactam there is a solution with excellent activity and selectivity for the Ethylene glycol formation [cf. for example: E. Watanabe et al. J. Chem. Soc., Chem. Commun. (3), 227 (1986)].

N-methyl can despite its stability play an active role in certain implementations, namely in hydrolysis, oxidation, condensation, reaction with chlorinating agents, polymerization and O-alkylation as well as related reactions.

Use according to the invention N-methylcaprolactam preferably also in the following known Processes in which it replaces NMP (see, for example, the BASF AG brochure, BASF Intermediates, N-methylpyrrolidones (NMP) ", No. CZ 3307 e-0291-2.0 (about 1994) and the literature quoted there, to which reference is hereby expressly incorporated is taken):

A) extraction of pure Hydrocarbons in petrochemical processing

One application of N-methylcaprolactam is in the recovery of hydrocarbons by extractive distillation. Here, one uses the high solubility of hydrocarbons in N-methylcaprolactam and the fact that volatility differences in the presence of N-methylcaprolactam are sometimes considerably increased. Compared with other commercial solvents and extraction media, N-methylcaprolactam offers the following advantages: no azeotropes are formed with hydrocarbons; N-methylcaprolactam is very resistant to heat and chemicals; and N-methylcaprolactam has a favorable toxicological and ecological profile.

N-methyl is miscible in all proportions with water. This allows the Setting the method to the desired conditions and the Stripping the loosened Hydrocarbons from the solvent. N-methylcaprolactam has a high low vapor pressure associated with it Boiling point, causing losses in separation processes on an industrial scale a minimum can be. The viscosity is at the usual Use temperatures low, which favors the mass transfer.

acetylene

N-methyl can be used successfully for the separation and purification of acetylene from cracked gas mixtures, the partial combustion of saturated hydrocarbons to be used [cf. for example: H. Höfermann et al., Chem. Industry 21, 860 (1969); H. Friz, Chem. Ing. Techn. 40 (20), 999 (1968)]. 8 to 10% of this pyrolysis reaction obtained gas volume consist of acetylene, about 4% of carbon dioxide, Hydrogen and carbon monoxide. At ambient conditions, N-methylcaprolactam dissolves a multiple of its own volume of acetylene. Acetylene can be light from the lightweight key component Carbon dioxide as well as higher Acetylenes are separated. A particular advantage of this method is that no There is a risk of spontaneous decomposition of acetylene.

Natural gas, Naphtha or LPG (LPG) are in the BASF immersion flame process in an acetylenic Gas converted [Ullmann's Encyclopedia of Industrial Chemistry, 5th ed., VCH Publishing Company, Weinheim, Vol. A1, 107 (1985)], quenching with water and coke deposits are removed or quenched with oil, coke deposits be removed and heat recovered becomes. The purification of the resulting cracking gas consists of two Stripping steps using N-methylcaprolactam as a selective solvent can be used.

1,3-butadiene

In the production of ethylene by the steam cracking process and similar large-scale pyrolysis reactions, a C ₄ fraction is obtained as a by-product in large quantities. The butadiene content of these fractions is usually about 40 to 50 g / 100 g.

N-methylcaprolactam is highly effective for the separation of butadiene from butene or from C ₄ -acetylenes because of its excellent selectivity. In the BASF butadiene process [U. Wagner and HM Weitz, Ind. Eng. Chem. 62, 43 (1970); B. Hausdörfer, U. Wagner and HM Weitz, Chem.-Ing.-Techn. 40 (23), 1147 (1968); K. Volkamer et al., Petroleum, Coal, Natural Gas, Petrochem. 34 (8), 343 (1981)], one can use N-methylcaprolactam containing, for example, 5 to 10 g of water / 100 g in a two-stage countercurrent gas scrubber. This gives butadiene of SBR quality (SBR = styrene-butadiene rubber) or poly-cis quality. The concentration of N-methylcaprolactam in the obtained pure butadiene is at most 10 mg / kg (ppm). By the same procedure, one can also separate C ₄ olefins and C ₄ paraffins.

In the BASF extractive distillation process [Ullmann's Encyclopedia of Industrial Chemistry, 5th ed., VCH Verlagsgesellschaft, Weinheim, Vol. A4, 437 (1985); Linnhoff and W. Lenz, Chem. Ing. Techn. 59 (11), 851 (1987); CA Abstract No. 140: 78725, 2004; CA Abstract No. 138: 402099, 2003] a butadiene of high purity (99.5 to 99.9 g / 100 g) and high yields (98%) is obtained from C ₄ hydrocarbon feeds. As an essential process step, it is possible to use N-methylcaprolactam, which contains, for example, about 8 g of water / 100 g, as a selective solvent, for example in a two-stage extractive distillation.

isoprene

The BASF process for the recovery of isoprene (2-methyl-1,3-butadiene) is a further development of the butadiene process described above. The separation can be carried out either by extractive distillation or by liquid-liquid extraction. As a rule, C ₅ cuts from pyrolysis reactions contain 15 to 20 g of isoprene / 100 g. The purity of the final product is high, eg 99% [H. Kröper and HM Weitz, Oil Gas J. 65 (2), 98 (1967)].

aromatics

According to the LURGI-Arosolvan process, it is possible to extract aromatics from hydrocarbon mixtures, such as reformate or hydrogenated pyrolysis gasolines [K. Eisenlohr, Erdöl and Kohle 16, 523 (1963); E. Müller and G. Höhfeld, Petroleum and Coal 24, 573 (1971); E. Müller, Chemist Newspaper 95, 996 (1971); E. Muller, Chem. And Industry 11, 518-22 (1973); E. Müller, VT Process Engineering 8 (3), 88 (1974)]. This gives a high yield of benzene, toluene, xylene and other aromatics with boiling points below 180 ° C. The addition of selected additives to N-methylcaprolactam ensures a solvent mixture with optimum selectivity and high solubility. The latter term is defined as the ratio of the aromatic concentration in the solvent phase to the aromatic concentration in the hydrocarbon phase.

N-methyl offers opposite other solvents et al the advantage that the Conditions for the distillative separation of the extracted aromatics due to Great Location of his boiling point are optimal. It is also advantageous that the phases be separated quite quickly using the density difference can and that N-methylcaprolactam chemically and thermally stable at the temperatures used in the process is.

In the Distapex process of LURGI GmbH, the extraction of pure benzene from the crude product is carried out by extractive distillation with NMP as a selective solvent, which can be replaced by N-methylcaprolactam. The same applies to toluene or xylene from the corresponding distillation phases. This process is particularly advantageous when the crude products are already available as separate B, T or X sections and the concentration of the aromatic compounds is above 70% [IB Lane et al., Chem. Process Eng. 48 (1), 49 (1967); E. Müller, VT Process Engineering 14, 551 (1980)]. It is also possible to separate mixtures of monocyclic and polycyclic alkyl-substituted or unsubstituted aromatics with a mixture of N-methylcaprolactam and water [compare: Ohio Oil, US 2,943,122 (1960)]. Furthermore, the separation of aromatic hydrocarbons from naphtha and kerosene with a boiling range of 30 to 300 ° C. is achieved by selective extraction with N-methylcaprolactam and reextraction with a cosolvent [see: Metallgesellschaft, EP-A-87 832 (1983)].

B) desulfurization of Gases and separation of acidic compounds in gases

In natural or synthetic gases, high concentrations of acidic compounds are often present. Examples include hydrogen sulfide, carbon dioxide sulfide, carbon dioxide and organic sulfur compounds. Their separation can also be preferably carried out by physical washing in several stages with a mixture of N-methylcaprolactam, alcohol and water, except for the use of a chemical process [see: Metallgesellschaft, GB 938 392 (1963) and DE 2 250 169 (1974); EP-A-13177; CA Abstract No. 82: 60774, 1984; CA Abstract No. 76: 61312, 1984].

Of the Difference between the Bunsen solubility coefficient for hydrogen sulfide and the one for Carbon dioxide is so great that these Gases can be easily separated and recovered in pure form [cf. G. Hochgesand, Ind. Eng. Chem. 62 (7), 32 (1970)].

C) Lubricating oils

at High-performance lubricants it is a mixture of petroleum fractions from which quality-reducing Aromatics and nitrogen, oxygen or sulfur compounds by solvent refining have been extracted. Then the components with the best lubrication properties - the isoparaffins - of the n-paraffins separated.

The Aromatics and other impurities dissolve to varying degrees in organic High boilers. These differences are used in their separation from the paraffins in technical solvent refining. One advantageous solvent For this Purpose is N-methylcaprolactam [See: J.D. Bushnell and R.T. Fiocco, Hydrocarbon Proc. 59 (5), 119 (1980); A. Sequeira, P.B. Sherman, T.U. Donciere and E.O. McBride, Hydrocarbon Proc. 58 (9), 155 (1979)].

At the Refining is the feed to the bottom of the extraction column supplied and allowed to flow countercurrent to the degassed N-methylcaprolactam. The column is thus designed as a multi-stage extraction zone. As a result the equilibrium that sets itself in all stages becomes on the head withdrawn a refined product containing the paraffins. The Extract that contains the more soluble components, i.e. which contains aromatics and other impurities withdrawn from the bottom of the column. For the recovery of N-methylcaprolactam have to then both streams, the refined product and the extract, at elevated temperature or reduced Pressure to be distilled. Finally, you get three separate parts: the practically N-methylcaprolactam-free paraffins that extracted Impurities and N-methylcaprolactam, in turn, to the head be returned to the extractor can.

N-methyl is much better than furfural and phenol for the lubricating oil extraction process [See: A. Sequeira et al., Hydrocarbon Proc. 58 (9), 155 (1979)].

As advantages of N-methylcaprolactam over other solvents are beispielswei Namely, N-methylcaprolactam is thermally and chemically stable, has favorable toxicological and ecological properties and excellent selectivity and is a very good solvent in terms of raffinate yields.

D) plastic

N-methyl can as a solvent for natural and synthetic plastics, waxes, resins, and various types of paints used become. It dissolves Polymers, such as cellulose derivatives, polymethyl methacrylate, polyamides, Polyimides, polyesters, polystyrene, polyacrylonitrile, polyvinyl chloride, Polyvinyl pyrrolidone, polyvinyl acetate, polyurethanes, polycarbonates, Polyethersulfones, polysulfones, polyethers and numerous copolymers.

N-methyl is with the corresponding monomers and with conventional organic solvents and water miscible. Therefore, one can choose the best possible solvent mixture for a given Determine application.

The The following examples illustrate the advantages of N-methylcaprolactam with a demonstration of possibilities to the solution problems that can occur in the plastics industry.

moldings

The Production of fibers, films, tapes, etc. from linear high polymers Represents frequently technological problems. The difficulty is that it depends solvents or softeners that are not corrosive, physiologically compatible and are not flammable at the processing temperature. In cases of this N-methylcaprolactam is very useful because it contains polyamides, Polyacrylonitrile, polyvinyl chloride, polystyrene and cellulose triacetate highly concentrated solutions or moldable masses can be produced. The same applies at elevated temperature for vinyl fluoride homopolymers and copolymers.

thanks its swelling and solubilizing effect can be N-methylcaprolactam also for cold welding be used by plastics.

synthetic fibers

aromatic Polyamides are excellent components for the production of films, Fibers and yarns used for technical applications needed offer extremely high strength. That in the industry as starting material preferred poly (p-phenylene terephthalamide) is by reaction of p-phenylenediamine and terephthalic acid dichloride in concentrated N-methylcaprolactam solvent systems accessible. Aramid high performance fibers and yarns can be made from spinning solutions of Poly (p-phenylene terephthalamide) or other polymer compositions based on polyamide according to conventional Wet and dry spinning process can be produced.

lithium chloride containing N-methylcaprolactam is a solvent for the preparation of polymers of aromatic diamines and aromatic acid chlorides, such as isophthalic acid chloride, form the fibers and coatings can and high temperature resistant are.

polyacrylonitrile, that in most organic solvents insoluble is, in N-methylcaprolactam with small amounts of lower aliphatic ketones solved become. These solutions can at relatively low Temperatures are spun into uniform fibers.

Fibrous poly (arylene ether sulfone) -poly (arylene terephthalate) block copolymers can using a solution of potassium carbonate and N-methylcaprolactam after interfacial process getting produced.

fibers of poly (arylacetylene) in organic solvents as wet-spun N-methylcaprolactam become.

urea can be condensed in N-methylcaprolactam at temperatures above 15q0 ° C with diamines become. The linear, uncrosslinked polyureas thus obtained have a high molecular weight and good mechanical properties and can to be processed into fibers. N-methylcaprolactam dissolves at elevated temperatures both the polymers and the monomers, but the polymers fall on cooling the solution to room temperature. Therefore, N-methylcaprolactam is a phenolic Solvent superior, because it simplifies the process and improves the quality.

at the synthesis of high-melting polyureas from aromatic Diamines and aromatic diisocyanates are N-methylcaprolactam as a non-corrosive, inert solvent for the Condensation reaction and subsequent spinning.

mixtures of polyacrylonitrile with formylated polyvinyl alcohol in solution in N-methyl and of polyacrylonitrile with poly (alkyl-alpha-acylaminoacrylates) are stable; they do not separate and can become homogeneous, non-segmented Spun fibers with high softening point and good dye affinity become.

N-methylcaprolactam and mixtures thereof with tetrahydrofuran or phenol are suitable for Preparation of spinning solutions of vinyl chloride polymers, vinylidene chloride polymers and synthetic linear condensed polyesters derived from polyethylene terephthalates. The solutions obtained are stable, do not gel and have a low viscosity at high solids content. They enable the production of fibers and films with superior physical properties for the production of wet or dry textiles.

membranes

N-methyl can be used to make semipermeable membranes. These membranes are used in separation processes such as ultrafiltration and Reverse osmosis used.

polyethersulfone can from multi-component mixtures of N-methylcaprolactam, water and the respective Polymers [See: G. Tkacik and L. Zeman, J. Membr. Sci. 31 (2-3), 273 (1987)].

The Properties of polysulfone membranes are determined by solutions in N-methylcaprolactam and Dimethylsulfoxide and calcium chloride as a pore forming agent affected.

at the production of reinforced Polysulfone membranes can Mixtures of N-methylcaprolactam and polyethylene glycols used as the swelling agent [See: X. Lu, C. Gao and X. Sun, Chem. Abstr. 104 (24) 208436v (1985)].

Synthesis of polymers

N-methyl allows the synthesis of new polymers and / or the synthesis of polymers while improving their quality.

at The production of polyurethane foams catalyses N-methylcaprolactam the foaming reaction too high hydrophilic, soft articles. In foamed polyether urethanes N-methylcaprolactam acts as a regulator to ensure open zelliger Structures. The properties of polyester urethane rubber solutions in Presence of N-methylcaprolactam are advantageous.

linear Synthetic polyamides are light in N-methylcaprolactam at 150 to 200 ° C soluble and poorly soluble at room temperature; The same applies to Polycaprolactam and copolymers of caprolactam with, for example N-vinyl caprolactam. This property enables the separation of impurities, such as unreacted monomers and colored substances by recrystallization.

polycondensation with the participation of aminocarboxylic acids and their lactams or Salts of polycarboxylic acids and polyamides can carried out in phenol become. When replacing this solvent obtained by N-methylcaprolactam one fibers or moldings with superior quality and simplifications of the production process.

at the production of linear, high-viscosity polyamides from ß-lactams are solvents like N-methylcaprolactam very well suited. N-methylcaprolactam dissolves the monomer and the activator and swells the precipitating polymer.

Become Acrylates or methacrylates in the presence of dipolar, aprotic Cocatalysts, such as N-methylcaprolactam, anionically polymerized, so the proportion of syndiotactic polymer increases, so that the obtained Products a more regular structure exhibit. Due to the obtained improvements in heat resistance, the solvent resistance and the mechanical properties, these products are suitable as Molding compounds and binders for Surface coatings.

The Handling the as a hardener for epoxy ether resins well-known m-phenylenediamine at room temperature is much easier and less dangerous when dissolved in N-methylcaprolactam. This solution extends the Pot life of the resin and impaired the curing behavior Not. A solidified at low temperatures melt is when thawed again to a homogeneous liquid.

The photocuring of acrylic epoxy resins can be treated with N-vinylpyrrolidone as a reactive diluent and N-methylcaprolactam as an unreactive diluent.

amorphous Polyacrylether, which are very temperature resistant, can advantageously be prepared using N-methylcaprolactam. By the use of weak bases avoids side reactions [See: D.K. Mohanty et al., Polymer Preprints 25 (2), 19 (1984)].

N-methyl can act as a reaction medium in the synthesis of high-performance poly (phenylene sulfide) for the Polymerization of p-dichlorobenzene and sodium sulfide can be used.

The ring-opening polymerization of poly (aminobenzoyl lactams) may be in the solvent system N-methyl caprolactam and lithium chloride.

E) Surface coatings

N-methyl is a non-corrosive high boiler with excellent solvent power and excellent chemical resistance. Therefore, N-methylcaprolactam improves the properties of many surface coating systems. Cheap these effects are especially for baked coatings, the be cured at relatively high temperatures. N-methyl allows the production of highly filled Paints and varnishes. Because it's the rheological properties improved, receives one coat of paint with a superior profile and superior Opacity. The coatings are therefore more homogeneous and non-porous and show no cratering and greater chemical resistance as well as a higher one Mechanic solidity.

N-methyl is an excellent solvent for the most starting materials for Coatings, such as acrylates, epoxy resins, polyurethanes, polyvinyl chloride systems, polyamide-imide-based wire enamels, aqueous basecoats and printing inks, e.g. For Inkjet printers, such as waterproof inkjet inks, optionally a UV-curable Resin included.

N-methyl is a useful one solvent for butadiene-acrylonitrile copolymers (e.g., Perbunan N) used to line tanks. The rubber solutions flow and are better than the solutions obtained with ketones.

By To solve Vinyl chloride-vinyl acetate copolymers in a mixture of N-methylcaprolactam and mononuclear aromatic hydrocarbons is obtained Solution, the for film casting can be used. Due to the synergistic effect between the two solvents have the solutions a low viscosity and can be easily applied.

polyisocyanates with imide groups in solvent systems be dissolved with N-methylcaprolactam. These solutions can be used for gumming of composites and metal surfaces.

Drahtlacke

One important feature of N-methylcaprolactam in the production of thermosetting Paints for the electrical insulation is its excellent solvent power for polycarboxylic acids and their anhydrides, such as trimellitic acid and pyromellitic anhydride, and polymers having high aromatic content amide and carboxyl groups.

So be in the condensation reaction between N-methylcaprolactam solutions of Anhydrides of polybasic carboxylic acids and monomeric polyfunctional isocyanates containing polyamide amide groups educated. The baked enamels obtained give coatings with excellent mechanical properties and dielectric properties on copper conductors. From the technical From the standpoint of N-methylcaprolactam, it has the advantage of being a Performs double function: It serves as a reaction medium in the manufacturing process and remains in the finished coating as a viscosity modifier.

N-methyl is suitable as a solvent for the resinous copolyester in the reaction between a diimide (like that of trimellitic anhydride and 4,4'-diaminodiphenylmethane obtained) and polyhydric alcohols (such as tris hydroxyethyl isocyanurate (THEIC) or ethylene glycol). The solutions thus formed can be very heat-resistant wire enamels be burned. N-methyl is also a solvent for polyamide / polyimide stoving enamels, resulting from the condensation of a tricarboxylic acid with aromatic and aliphatic Derive diamines.

Solvent mixtures N-methylcaprolactam and dicarboxylic acid esters are suitable for use in the manufacture of wire enamels based on polyvinyl formal.

F) paint stripping and cleaning

by virtue of its high solvent power for plastics, Resins, oil and fat can be N-methylcaprolactam with success as an ingredient in paint removers, detergents and degreasing agents are used. Its miscibility with Water and the most conventional organic solvents allows the Production of highly effective products targeted to different Applications can be turned off. The ecological and toxicological Data from N-methylcaprolactam are compared to most others solvents Cheap. N-methyl is not corrosive. Mixtures containing N-methylcaprolactam and others solvent contain, often show desirable synergistic effects.

N-methyl can for alone or in mixtures to remove oil, carbon deposits and other tarry polymeric residues from metal chambers, pistons and cylinders and for wet cleaning of internal combustion engines become.

N-methylcaprolactam can be part of mixtures used in industry for cleaning soiled metal parts and equipment. Certain hard to dissolve polyurethanes are best cleaned with mixtures of N-methylcaprolactam and dicarboxylic acid esters.

mixtures of N-methylcaprolactam with other organic solvents and adjuvants are used to remove ink residues.

With Mixtures containing N-methylcaprolactam as a key ingredient contain, remove epoxies and similar chemically resistant coatings of steel surfaces and temporary coatings of parts optical instruments.

Solvent mixtures, which contain N-methylcaprolactam as the reactive component are suitable for the Preparation of a foam type paint remover for use in the removal of various paints, clearcoats, air-drying Paints and other coatings or Paint, especially of relatively large surfaces, is suitable.

N-methyl can be used to formulate paint removers that are light are environmentally friendly and reduce the risk of fire.

mixtures of N-methylcaprolactam for cleaning objects or surfaces, through substances like oil, Fat, soot, Paint and glue are dirty by immersion in a bath be used. An important field of application is in this context the degreasing of metals before further surface treatment, Coating or galvanization. To be used cleaning baths included N-methylcaprolactam, odor masking agents, surfactants and diluents. By using a water absorption preventing layer The water absorption of the cleaner can be significantly delayed.

On N-methylcaprolactam based products are suitable for use in the removal of weathered emulsion paints on exterior walls, for Renovation of interiors, for the removal of graffiti and for the ultrasonic cleaning of objects such as optical lenses or dentures.

The following solvents can be used in combination with surfactants, thickeners, and other additives to develop high solvent and swelling systems:
Butanol, butyl acetate, butyl glycol acetate (1-butoxy-ethyl acetate), gamma-butyrolactone, 2-ethylhexyl acetate, 1-methoxy-2-propyl acetate, nonanol, pentyl acetate, Solvenon PM (1-methyl-2-propanol) and tridecanol.

G) Plant protection

N-methyl can as a solvent or cosolvent for the formulation of insecticides, fungicides, herbicides, seed treatment products and bioregulators are used where high polar compounds required are. N-methyl is opposite other highly polar solvents preferred as it is when used as a solvent or cosolvent in pesticide formulations that are applied to growing crops be exempted from the requirement for tolerance and a cheap one toxicological and ecological Own profile. It is particularly suitable for multicomponent systems.

N-methyl forms adducts with bacteriostats, such as substituted ureas, Carbanilides, thiocarbamates, guanidines and salicylanilides. These Products are more bactericidal and allow better control of the product Growth of bacterial cultures.

H) Production of electronic devices

For the production of integrated circuits (ICs) are products with very high Requires purity. In particular, electronic grade N-methylcaprolactam becomes according to the method according to EP-A1-1 038 867 (BASF AG) or US-A-5,777,131 (BASF Corp.). This makes N-methylcaprolactam an excellent solvent for the Electronics industry and manufacturers of printed circuit boards. mixtures of N-methylcaprolactam with common ones solvents can used for cleaning and degreasing single crystal silicon wafers for ICs become.

By the use of N-methylcaprolactam as a diluent in polyamide-imide, Urethane and epoxy resins to get a smooth surface. The slow rate of evaporation of N-methylcaprolactam allows the formation of very homogeneous coatings.

In of microphotolithography (the key to the production of electronic Chips), N-methylcaprolactam shows excellent performance in developers for curable Polyimides and in photoresist strippers.

In the final production step, ICs are encapsulated with resins, such as epoxy molding compounds. In this case, resin flash ("flash") remains on the encapsulated IC package or terminal comb and on the encapsulant. A finishing step can be performed by softening the resin with N-methyl caprolactam so that it can then easily washed away with compressed air or high-pressure water (chemical Entflashen). It is recommended that this procedure be carried out immediately after molding and before post-curing.

On Printed circuit boards become semiconductors and other electrical components soldered. This must be a flux be used. After soldering have to Flux residues removed to prevent corrosion. This can be done with solvent blends done that as a key component N-methylcaprolactam included.

One Another field of application is the selective removal of polymer coatings from certain areas on circuit boards.

I)

N-methyl or mixtures thereof as absorption media for the removal or separation of organic compounds Off- or flue gases, such as sulfur dioxide, hydrogen sulfide and Vinyl chloride, find wide application.

at the processing of adhesives containing organic solvents you can part of these solvents replace with N-methylcaprolactam to increase the vapor concentration reduce. PVC or ABS adhesives consisting mainly of N-methylcaprolactam and / or gamma-butyrolactone show a reduced risk of fire. Because both products are a relatively small Vapor pressure, the inhalation risk is significantly reduced.

J) colors and pigments

For colors with azo compounds can be diazotizable Amine dispersions with N-methylcaprolactam, which dissolves the diazo and coupling components. to Improvement of the formation and durability of shades can N-methyl in coloring of polyamide, acrylic, polyester fibers, fabrics, films and of polyester-cotton blends. In colors, lithographic inks and other protective or decorative pigment coatings N-methylcaprolactam effectively disperses many organic or inorganic color pigments, without the water sensitivity of the film to increase. 1% solvent (based on pigment) facilitates grinding and increases coloring power as a result of the pigment refining. N-methylcaprolactam improves the stability against obsolescence, results in reduced color drift and stabilized the system against flocculation and solidification.

K)

In addition, N-methylcaprolactam can be used
as a solvent for developers (photo / reproduction technology), for the production of high-performance adhesives and technical adhesive removers,
as a solvent for slime control agents used in papermaking and paperboard production,
as a reaction medium or solvent in the synthesis of organic intermediates and pharmaceuticals,
as a solvent for coal extraction and oil refining,
as a component in fluids for the production of printing plates,
for the removal of impurities and adhesives, in particular on cyanoacrylate-based adhesives, polymers, plastics (eg polymethacrylates), glass, metal, ceramic, stone and fiber surfaces and also of the skin.

L)

N-methyl also finds particular use according to the invention as NMP replacement in the above-cited NMP procedures and operations.

M)

N-methyl can replace successfully and favorably: dimethylformamide (DMF), especially in aqueous Coatings, methylene chloride, especially when stripping of Memory chips, perchlorethylene and trichlorethylene, in particular in vapor degreasing processes, chlorine-containing solvents (e.g., chlorinated Hydrocarbons, in particular chlorinated C1-C6 hydrocarbons, such as tetrachlorethylene and trichlorethylene) e.g. in ultrasonic cleaning processes, Caustic soda when purifying reactors e.g. for removing urethane residues, Furfural phenol in lubricant extractions and glycol ethers, e.g. in household and industrial cleaners and coatings, ethers like e.g. THF, diethylene glycol dialkyl ether, 1,2-diethoxyethane and 1,2-dimethoxyethane, e.g. in chemical reactions.

N-methyl is for the uses according to the invention in particular with a purity of greater than 97 wt .-%, in particular greater than 98% by weight, especially greater than 99% by weight, e.g. greater than 99.8 or greater than 99.9 Wt .-%, used. These purities can be by single or multiple Distillation or rectification can be achieved.

N-methylcaprolactam with high purity for Use according to the invention is obtained in particular by the methods according to EP-A-1 038 867 (BASF AG) and US-A-5,777,131 (BASF Corp.) (see below).

The preparation and purification of N-methylcaprolactam is known:
The preparation of N-methylcaprolactam can be carried out by reaction of gamma-butyrolactone with monoethylamine at elevated temperature and elevated pressure to release one molar equivalent of water, e.g. For example, Ullmann's Encyclopedia of Industrial Chemistry, Volume A22, 5th ed., Page 459 (1993).

The Production of N-methylcaprolactam can also be achieved by methylation of epsilancaprolactam, e.g. with methanol; see, e.g. Chem. Abstract No. 120: 191559 (RO-B1-102421) and Chem. Abstract No. 118: 233904 (EP-A1-531 673) and DD-A1-267 729.

EP-A1-1 038 867 (BASF AG) and US-A-5,777,131 (BASF Corp.) describe processes for the purification of N-substituted lactams such as NMP and N-methylcaprolactam, wherein the contaminated N-substituted lactams with a acidic, especially macroporous, Cation exchanger treated.

Claims (17)

Use of N-methylcaprolactam as solvent, Diluents, Extractants, detergents, degreasers, absorbents and / or dispersing agent. Use of N-methylcaprolactam as solvent and / or extraction agents in processes for the decomposition of gas mixtures. Use of N-methylcaprolactam after the preceding Claim, wherein the gas mixtures in cracking processes from hydrocarbons receives. Use of N-methylcaprolactam according to one of both previous claims for the separation of acetylene, 1,3-butadiene and / or aromatics. Use of N-methylcaprolactam as solvent for polymers and / or copolymers. Use of N-methylcaprolactam after the preceding Claim, wherein the polymers and / or copolymers to Polymethylmethacrylate, polyester, polyacrylonitrile, acrylonitrile-containing Copolymers, butadiene-containing copolymers, styrene-containing copolymers, N-vinylpyrrolidone-containing copolymers, vinyl chloride-containing copolymers, Vinyl acetate-containing copolymers, methyl methacrylate-containing copolymers, terephthalic acid polyester, Polyvinyl chloride, polyvinylpyrrolidone, polyvinyl acetates, polycarbonates, Polyethers, polyethersulfones, polystyrene, polyamides, polyimides and / or Polyurethanes act. Use of N-methylcaprolactam as solvent for resins, Cellulose derivatives and dyes. Use of N-methylcaprolactam as solvent, thinner and / or dispersants in chemical reactions. Use of N-methylcaprolactam after the preceding Claim, wherein the chemical reactions are C-C linking reactions and / or polymerizations. Use of N-methylcaprolactam as solvent in processes for the production of wire enamels. Use of N-methylcaprolactam as solvent and / or absorbents in gas scrubbing processes. Use of N-methylcaprolactam according to the preceding claim for the separation of SO ₂ , H ₂ S and / or vinyl chloride. Use of N-methylcaprolactam as solvent, Cleaning agents and / or degreasing agents in processes for the preparation of integrated circuits (ICs). Use of N-methylcaprolactam as a partial or more completely Replacement for N-methyl-2-pyrrolidone (NMP), chlorinated hydrocarbons and / or Ether. Use of N-methylcaprolactam according to one of claims 1 to 13 as a partial or complete replacement of N-methyl-2-pyrrolidone (NMP), chlorinated hydrocarbons and / or ethers. Use of N-methylcaprolactam according to one of previous claims, wherein N-methylcaprolactam is used in a purity of> 99 wt .-%. Use of N-methylcaprolactam according to one of previous claims, wherein N-methylcaprolactam is used, previously with an acid Cation exchanger was treated.