MXPA97007977A - A method to prepare monome - Google Patents

Abstract

A method for preparing monomers useful in a wide range of polymer is disclosed

Description

A METHOD FOR PREPARING MONOMERS This invention relates to a method for preparing monomers, in particular to a suitable method for preparing monomers useful in a wide range of polymers. High molecular weight alcohols (C20 ~ 3QO) are known as synthetic wax alcohols and have been in commercial production for several years. While synthetic wax alcohols have limited use in candle waxes, synthetic wax monomers are very useful in a wide range of polymers. The use of synthetic wax alcohols would significantly increase if there were a process for converting them into synthetic wax monomers. There is a progressive need for a method of preparing synthetic wax monomers from synthetic wax alcohols. Japanese Patent Application J 6-329720 discloses polyethylene macromonomers with a terminal group of (meth) acryloyl and a method for the preparation of these monomers. According to the method described, a polyethylene derivative is reacted with specific carbonyl compounds or oxidized with oxygen to produce the polyethylene alkoxide and then reacted with a halide of (meth) acrylic acid to supply the product wanted.

Another method known in the art is the use of transesterification to produce short chain acrylate esters. This method has been carried out routinely using catalysts selected from the elements of the IVA Group, such as, for example, Sn, Ge and Pb; Group IVB elements such as, for example, Ti and Hf; elements of the VA Group, such as, for example, the As and Sb; and the Fe as an element of Group VIII, see, for example, the patent of E. U. A., No. 5,037,948. These catalysts require relatively high levels of use to be effective and can be difficult to remove from the final product. Strong acids, such as, for example, methanesulphonic acid, and strong alkalis, such as, for example, lithium hydroxide, are also known to catalyze transesterifications. These catalysts are also inconvenient due to their corrosive nature. If not removed from the product, these catalysts can interfere with subsequent polymerizations and end uses. The removal of the catalyst from the product is also difficult. Despite the description of the prior art, there is a continuing need for a method of preparing synthetic wax monomers from synthetic wax alcohols.

We have found, surprisingly, that zirconium compounds are extremely effective in catalyzing the transesterification reactions that produce synthetic wax monomers from synthetic wax alcohols. Very low levels of zirconium compounds can be used effectively. An advantage of the present invention is that the zirconium compound does not need to be removed from the final product, due to its low use level and its benign character in downstream applications. The present invention provides a method for preparing synthetic wax monomers, this method comprises: mixing an alcohol of synthetic wax, an ester of (meth) acrylate, a zirconium compound and an inhibitor, selected from the group consisting of the compounds containing nitroxyl, hydroquinone, methoxy-hydroquinone, phenothiazine and copper compounds; heat the mixture to 100-165 ° C, to supply the synthetic wax monomer, and remove the lower alcohol from the synthetic wax alcohol and the (meth) acrylate ester. The lower alcohol, formed from the reaction of the synthetic wax alcohol and the (meth) acrylate ester, can be removed by fractional distillation. The excess of (meth) acrylate ester can be separated from the product.

Synthetic wax alcohols are commercially available as the Unilin ™ or Unithox ™ products sold by Petrolite Inc. Suitable synthetic wax alcohols for use in this invention include the linear alcohols (C2? ~ C5?) And their ethoxylates. The (meth) acrylate esters are commercially available from Rohm and Haas Company. Suitable (meth) acrylate esters for use in this invention include, but are not limited to, methyl acrylate, ethyl acrylate, propyl acrylate, and n-butyl acrylate.; and methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, isopropyl methacrylate, isobutyl methacrylate and t-butyl methacrylate. Typically, the (meth) acrylate ester and the synthetic wax alcohol are reacted on a molar basis of 2-ester of (meth) acrylate to 1 alcohol of synthetic wax to ester of (meth) acrylate to 1 alcohol of synthetic wax . More preferred is the ratio of 3-ester of (meth) acrylate to 1 alcohol of synthetic wax to 9-ester of (meth) acrylate to 1 alcohol of synthetic wax. Especially preferred is the ratio of 4-ester of (meth) acrylate to 1 alcohol of synthetic wax to 8 ester of (meth) acrylate to 1 alcohol of synthetic wax.

Zirconium compounds are commercially available from Aldrich Chemical Company. Zirconium compounds suitable for use in this invention include zirconium acetylacetonate, zirconium butoxide, zirconium tertiary butoxide, zirconium chloride, zirconium ammonium citrate complex, zirconium ethoxide, zirconium fluoride, zirconium hydride, complex of zirconium isopropoxide and isopropanol, zirconium oxide, zirconium propoxide, zirconium sulfate hydrate, zirconium tetrachloride and zirconium silicate. Zirconium acetylacetonate is preferred. The zirconium compound can be added from 0.1 to 10% based on the moles of the synthetic wax alcohol. More preferred is 0.5 to 7.5% of the zirconium compound based on the moles of the synthetic wax alcohol. Especially preferred is from 1 to 4% of the zirconium compound based on the moles of the synthetic wax alcohol. Suitable inhibitors for use in this invention include, but are not limited to, compounds containing nitroxyl, hydroquinone, methoxy-hydroquinone, phenothiazine and copper compounds. The inhibitors are commercially available from Aldrich Chemical Company. Suitable copper compounds include cupric acetate, cupric bromide, cupric chloride, cupric 2-ethylhexanoate, cupric fluoride, cupric gluconate, cupric nitrate, cupric methoxide, cupric sulfate, and cupric dibutyl-dithio-carbamate. The dibutyl-dithio-carbamate cupric is preferred. Compounds containing a suitable nitroxyl radical include 2, 2, 6, 6-tetramethyl-1-piperidinyloxy, ("4-hydroxy-TEMPO") free radical, 4-oxo-2, 2, 6, 6-tetramethyl -l-piperidinyloxy, ("4-oxo-TEMPO") free radical, and tertiary-dibutyl-nitroxyl (DtBN) (available from Nova Molecular Technologies, Lake Geneva, Wisconsin). The inhibitor can be added in 100 to 4,000 ppm based on the total weight of the synthetic wax alcohol and the (meth) acrylate ester to be reacted. More preferred is 500 to 3,000 ppm of the inhibitor, based on the total weight of the synthetic wax alcohol and the (meth) acrylate ester to be reacted. More preferred is 1,000 to 2,000 ppm of the inhibitor, based on the total weight of the synthetic wax alcohol and the (meth) acrylate ester to be reacted. The following examples attempt to illustrate the method of obtaining the synthetic wax monomers from the synthetic wax alcohols. All percentages are based on weight. The abbreviations used are: g = grams, mm = millimeters, 1 = liter,% = percent, N2 = nitrogen, O2 = oxygen, n = normal and ° C = degrees centigrade.

Example 1 - C40 Alcohol Acrylate A 5 liter flask, equipped with an overhead stirrer, a 5.08 cm Oldershaw column of 10 plates, a thermal and controller pair, a graduated receiver, a magnetically controlled reflux head and a spray of 8 % O2 / 92% of N2, at 19.5 cubic centimeters per minute, was charged with 2,000 g of Unilin® 550 (a synthetic, primary, linear wax alcohol). To this was added 1,164 g of n-butyl acrylate and 1.4 g of 4-hydroxy-TEMPO. While stirring and spraying, the batch was heated to 100 ° C. When the homogeneous solution was obtained, 20.0 g of zirconium acetylacetonate were added. The vacuum was increased to 200 mm and the temperature was increased to 120-125 ° C. The vacuum and temperature were kept constant until the steam temperature reached 97 ° C. At this point, the transesterification was complete. The total time from the addition of zirconium acetylacetonate to complete the reaction was 2.45 hours. The vacuum and temperature were reduced. The column was removed and a deflection head of the straight direction was installed. The vacuum was then increased to 25 mm and the temperature was increased to 125 ° C. The temperature and vacuum were maintained until the distillation was stopped. The molten product was removed at 125 ° C. The conversion of the Unilin® 550 alcohol to the acrylate ester was quantitative, as measured by the Nuclear Magnetic Resonance ("NMR") spectrum. The product contained 0.12% residual butyl acrylate, as measured by gas chromatography ("GC").

Example 2 - Alcohol Acrylate C? N A 5 liter flask, equipped with an overhead stirrer, a 5.08 cm Oldersha column of 10 plates, a thermal and controller pair, a graduated receiver, a magnetically controlled reflux head and a spray from 8% O2 / 92% N2, to 19.5 cubic centimeters per minute, was loaded with 2,500 g Unilin® 700 (a synthetic, primary, linear wax alcohol). To this were added 1,250 g of n-butyl acrylate and 1.75 g of 4-hydroxy-TEMPO. While stirring and spraying, the batch was heated to 100 ° C. When a homogeneous solution was obtained, 25.0 g of zirconium acetylacetonate were added. The vacuum was increased to 200 mm and the temperature was increased to 120-125 ° C. The vacuum and temperature were kept constant until the steam temperature reached 97 ° C. At this point, the transesterification was complete. The total time from the addition of zirconium acetylacetonate to complete the reaction was 2.37 hours. The vacuum and temperature were reduced. The column was removed and a deflection head of the straight direction was installed. The vacuum was then increased to 25 mm and the temperature was increased to 125 ° C. The temperature and vacuum were maintained until the distillation was stopped. The molten product was removed at 125 ° C. The conversion of the Unilin® 700 alcohol to the acrylate ester was 98.5%, as measured by the NMR spectrum. The product contained 0.1% residual butyl acrylate, as measured by gas chromatography ("GC").

Example 3 - C Alcohol Acrylate ?? A 5-liter flask, equipped with an overhead stirrer, a 5.0-inch Oldersha column of 10 plates, a thermal and controller pair, a graduated receiver, a magnetically controlled reflux head and a spray of 8% O2 / 92% N2, at 19.5 cubic centimeters per minute, was charged with 456.4 g of Alcohol Nafol® 1822 (a synthetic, primary, linear wax / 100% functionality alcohol). To this were added 581.5 g of n-butyl acrylate and 0.7 g of 4-hydroxy-TEMPO. While stirring and spraying, the batch was heated to 100 ° C. When a homogeneous solution was obtained, 9.9 g of zirconium acetylacetonate were added. The vacuum was increased to 200 mm and the temperature was increased to 120-125 ° C. The vacuum and temperature were kept constant until the steam temperature reached 97 ° C. At this point, the transesterification was complete. The total time from the addition of the zirconium acetylacetonate to complete the reaction was 0.90 hours. The vacuum and temperature were reduced. The column was removed and a deflection head of the straight direction was installed. The vacuum was then increased to 25 mm and the temperature was increased to 125 ° C. The temperature and vacuum were maintained until the distillation was stopped. The molten product was removed at 125 ° C. The conversion of Nafol® 1822 alcohol to the acrylate ester was quantitative, as measured by the NMR spectrum. The product contained 0.24% residual butyl acrylate and residual butanol, as measured by gas chromatography ("GC").

Example 4 - Ethoxylated Alcohol Acrylate A 5 liter flask, equipped with an overhead stirrer, a 5.08 cm Oldershaw column of 10 plates, a thermal and controller pair, a graduated receiver, a magnetically controlled reflux head and a spray of 8 % O2 / 92% N2, at 19.5 cubic centimeters per minute, was charged with 2,373.5 g of Unithox® 450 Ethoxylate (a synthetic, primary, linear, ethoxylated wax alcohol / 82% alcohol functionality). To this were added 809.6 g of n-butyl acrylate and 1.2 g of 4-hydroxy-TEMPO. While stirring and spraying, the batch was heated to 100 ° C. When a homogeneous solution was obtained, 20.0 g of zirconium acetylacetonate were added. The vacuum was increased to 200 mm and the temperature was increased to 165 ° C. The vacuum and temperature were kept constant until the steam temperature reached 97 ° C. At this point, the transesterification was complete. The total time from the addition of the zirconium acetyl acetonate to complete the reaction was 3.60 hours. The vacuum and temperature were reduced. The column was removed and a deflection head of the straight direction was installed. The vacuum was then increased to 25 mm and the temperature was increased to 125 ° C. The temperature and vacuum were maintained until the distillation was stopped. The molten product was removed at 125 ° C. The conversion of the ethoxylate alcohol Unithox® 450 to the acrylate ester was 92%, as measured by the NMR spectrum. The product contained 0.04% residual butyl acrylate, as measured by gas chromatography ("GC").

Example 5 - Cg Alcohol Methacrylate A 5 liter flask, equipped with an overhead stirrer, a 5.0 inch Oldersha column of 10 plates, a thermal and controller pair, a graduated receiver, a magnetically controlled reflux head and a spray of 8 % of O2 / 92% of N2, at 19.5 cubic centimeters per minute, was charged with 430 g of Unilin® 425 (a synthetic wax alcohol, primary, linear / 84.3% alcohol functionality). To this were added 240.3 g of methyl methacrylate and 0.5 g of 4-hydroxy-TEMPO. While stirring and spraying, the batch was heated to 100 ° C. When a homogeneous solution was obtained, 2.5 g of zirconium acetylacetonate were added. The vacuum was increased to 400 mm and the temperature was increased to 135 ° C. The vacuum and temperature were kept constant until the steam temperature reached 97 ° C. At this point, the transesterification was complete. The total time from the addition of zirconium acetylacetonate to complete the reaction was 1.0 hour. The vacuum and temperature were reduced. The column was removed and a deflection head of the straight direction was installed. The vacuum was then increased to 25 mm and the temperature was increased to 125 ° C. The temperature and vacuum were maintained until the distillation was stopped. The molten product was removed at 125 ° C. The conversion of Unilin® 425 alcohol to the acrylate ester was quantitative, as measured by the NMR spectrum. No residual methyl methacrylate was detected by gas chromatography.

Example 6 - C Co Alcohol Acrylate and Comparison of Inhibitors Example 1 was repeated and the 4-hydroxy-TEMPO was replaced by 1,4-hydroquinone. A 5-liter flask, equipped with an overhead stirrer, a 5.08 cm Oldershaw column of 10 plates, a thermal and controller pair, a graduated receiver, a magnetically controlled reflux head and a spray of 8% O2 / 92% N2, at 19.5 cubic centimeters per minute, was charged with 2,000 g of Unilin® 550 (a synthetic, primary, linear wax alcohol). To this were added 1,164 g of n-butyl acrylate and 1.4 g of 1,4-hydroquinone. While stirring and spraying, the batch was heated to 100 ° C. When a homogeneous solution was obtained, 20.0 g of zirconium acetylacetonate were added. The vacuum was increased to 200 mm and the temperature was increased to 120-125 ° C. The vacuum and temperature were kept constant until the steam temperature reached 97 ° C. At this point, the transesterification was complete. The total time from the addition of zirconium acetylacetonate to complete the reaction was 2.45 hours. The vacuum and temperature were reduced. The column was removed and a deflection head of the straight direction was installed. The vacuum was then increased to 25 mm and the temperature was increased to 125 ° C. The temperature and vacuum were maintained until the distillation was stopped. The molten product was removed at 125 ° C. The conversion of the Unilin® 550 alcohol to the acrylate ester was 98.%, as measured by the NMR spectrum. The product contained 0.28% residual butyl acrylate, as measured by gas chromatography.

Example 7 - Alcohol Methacrylate C n With Hydroquinone Inhibitor A 5-liter flask, equipped with an overhead stirrer, a 5.0-inch Oldershaw column of 10 plates, a thermal and controller pair, a graded receiver, a magnetically controlled reflux head and a spray of 8% O2 / 92% N2, at 19.5 cubic centimeters per minute, was charged with 500 g Unilin® 550 (a synthetic, primary, linear wax alcohol). To this were added 375 g of methyl methacrylate and 0.4 g of hydroquinone. While stirring and spraying, the batch was heated to 100 ° C. When a homogeneous solution was obtained, 0.8 g of zirconium acetylacetonate was added. The reaction was distilled at this temperature for 3 hours. Another 0.4 g of zirconium acetylacetonate was added, the temperature of the kettle was increased to 125 ° C and the reaction was distilled for one hour. The total time from the addition of the zirconium acetylacetonate to complete the reaction was 4.15 hours. The column was removed and a deflection head of the straight direction was installed. The vacuum was then increased to 25 mm and the temperature was increased to 125 ° C. The temperature and vacuum were maintained until the distillation was stopped. The molten product was removed at 125 ° C. The conversion of Unilin® 550 alcohol to methacrylate ester was quantitative, as measured by the NMR spectrum. The product contained 0.45% residual butyl methacrylate, as measured by gas chromatography.

Example 8 - Methacrylate of Ethoxylated Alcohol With Hydroquinone Inhibitor A 5-liter flask, equipped with an overhead stirrer, a 5.0-inch Oldersha column of 10 plates, a thermal and controller pair, a graduated receiver, a magnetically controlled reflux head and a spray of 8% O2 / 92% N2, at 19.5 cubic centimeters per minute, was loaded with 451 g Unithox® 450 (a synthetic wax, primary, linear / 82% functionality alcohol). To this were added 719 g of methyl methacrylate and 1.0 g of hydroquinone. While stirring and spraying, the batch was heated to 100 ° C. When a homogeneous solution was obtained, 3.77 g of zirconium acetylacetonate were added. The vacuum was increased to 200 mm and the temperature was increased to 108 ° C. The reaction was distilled for 2.5 hours. The total time from the addition of the zirconium acetylacetonate to complete the reaction was 3.0 hours. The vacuum and temperature were reduced. The column was removed and a deflection head of the straight direction was installed. The residual methyl methacrylate was separated for another hour. The molten product was removed to 108 ° C. The conversion of Unithox® 450 alcohol to the methacrylate ester was 92%, as measured by the spectrum of NMR. The product contained 0.44% residual methyl methacrylate, as measured by gas chromatography.

Example 9 - Comparative Example - Alcohol Acrylate With Potassium Tertiary Butoxide A 5-liter flask, equipped with an overhead stirrer, a 5.0-inch Oldersha column of 10 plates, a thermal and controller pair, a graduated receiver, a magnetically controlled reflux head and a spray of 8% O2 / 92% N2, at 19.5 cubic centimeters per minute, was charged with 2,000 g Unilin® 550 (a synthetic, primary, linear wax alcohol). To this was added 1,164 g of n-butyl acrylate and 1.4 g of 4-hydroxy-TEMPO. While stirring and spraying, the batch was heated to 100 ° C. When a homogeneous solution was obtained, 20.0 g of potassium tertiary butoxide were added. The vacuum was increased to 200 mm and the temperature was increased to 120-125 ° C. The vacuum and temperature were kept constant until the steam temperature reached 97 ° C. The total time from the addition of zirconium acetylacetonate to complete the reaction was 2.45 hours. The vacuum and temperature were reduced. The column was removed and a deflection head of the straight direction was installed. The vacuum was then increased to 25 mm and the temperature was increased to 125 ° C. The temperature and vacuum were maintained until the distillation was stopped. The molten product was removed at 125 ° C. The conversion of the Unilin® 550 alcohol to the acrylate ester was 10.7%, as measured by the NMR spectrum. The product contained 0.63% residual butyl acrylate, as measured by gas chromatography.

Example 10 - Comparative Example Alcohol Acrylate With Dibutyl Tin Methoxide A 5 liter flask, equipped with an overhead stirrer, a 5.08 cm Oldershaw column of 10 plates, a thermal and controller pair, a graduated receiver, a magnetically controlled reflux head and a spray of 8% O2 / 92% N2, at 19.5 cubic centimeters per minute, was charged with 2,000 g Unilin® 550 (a synthetic, primary, linear wax alcohol). To this was added 1,164 g of n-butyl acrylate and 1.4 g of 4-hydroxy-TEMPO. While stirring and spraying, the batch was heated to 100 ° C. When a homogeneous solution was obtained, 20.0 g of dibutyltin dimethoxide was added. The vacuum was increased to 200 mm and the temperature was increased to 120-125 ° C. The vacuum and temperature were kept constant until the steam temperature reached 97 ° C. At this point, the transesterification was complete. The total time from the addition of zirconium acetylacetonate to complete the reaction was 2.45 hours. The vacuum and temperature were reduced. The column was removed and a deflection head of the straight direction was installed. The vacuum was then increased to 25 mm and the temperature was increased to 125 ° C. The temperature and vacuum were maintained until the distillation was stopped. The molten product was removed at 125 ° C. The conversion of Unilin® 550 alcohol to the acrylate ester was quantitative, as measured by the NMR spectrum. The product contained 0.64% residual butyl acrylate, as measured by gas chromatography. Although the conversion was good, tin is quite toxic and has to be removed from the product. The removal of tin from the product was very difficult.

EXAMPLE 11 - COMPARATIVE EXAMPLE - C Cn Alcohol Acrylate with Magnesium Methoxide A 5 liter flask, equipped with an overhead stirrer, a 5.08 cm Oldershaw column of 10 plates, a thermal and controller pair, a graduated receiver, a head of magnetically controlled reflow and a spray of 8% O2 / 92% N2, at 19.5 cubic centimeters per minute, was charged with 2,000 g of Unilin® 550 (a synthetic, primary, linear wax alcohol). To this was added 1,164 g of n-butyl acrylate and 1.4 g of 4-hydroxy-TEMPO. While stirring and spraying, the batch was heated to 100 ° C. When a homogeneous solution was obtained, 20.0 g of methyl magnesium carbonate (8% in methanol) were added. The vacuum was increased to 200 mm and the temperature was increased to 120-125 ° C. The vacuum and temperature were kept constant until the steam temperature reached 97 ° C. The total time from the addition of zirconium acetylacetonate to complete the reaction was 2.45 hours. The vacuum and temperature were reduced. The column was removed and a deflection head of the straight direction was installed. The vacuum was then increased to 25 mm and the temperature was increased to 125 ° C. The temperature and vacuum were maintained until the distillation was stopped. The molten product was removed at 125 ° C. The conversion of Unilin® 550 alcohol to the acrylate ester was 1.5%, as measured by the NMR spectrum. The product contained 0.8% residual butyl acrylate, as measured by gas chromatography. The above examples demonstrate that the method of this invention is very effective in converting the synthetic wax alcohols into the synthetic wax monomers, without the need to remove the catalyst from the product. The other catalysts tested gave a poor conversion of the synthetic wax alcohol into the synthetic wax monomer, or required the removal of the catalyst from the product.

Claims (6)

1. CLAIMS 1. A method for preparing synthetic wax monomers, this method comprises: mixing a synthetic wax alcohol, a (meth) acrylate ester, a zirconium compound and an inhibitor, selected from the group consisting of compounds containing radicals of nitroxyl, hydroquinone, methoxy-hydroquinone, phenothiazine and copper compounds; heat the mixture to 100-165 ° C, to supply the synthetic wax monomer; and removing the lower alcohol from the synthetic wax alcohol and the (meth) acrylate ester.
2. 2. The method, according to claim 1, wherein the (meth) acrylate ester is selected from the group consisting of methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, (met) acrylate of n. -butyl, isopropyl methacrylate, isobutyl methacrylate and t-butyl methacrylate.
3. 3. The method, according to claim 2, in which the (meth) acrylate ester is methyl (meth) acrylate, the zirconium compound is zirconium acetylacetonate, and the inhibitor is the free radical of 2.2, 6,6-tetramethyl-1-piperidinyloxy.
4. 4. The method, according to claim 2, in which the (meth) acrylate ester is n-butyl (meth) acrylate, the zirconium compound is zirconium acetylacetonate and the inhibitor is the free radical of 2.2 , 6,6-tetramethyl-1-piperidinyloxy.
5. 5. The method, according to claim 1, wherein the synthetic wax alcohol is selected from the group consisting of linear alcohols (20-C50), and their ethoxylates.
6. 6. The method, according to claim 1, further comprising the additional step of separating the excess of the (meth) acrylate ester.