Catalyst resin

#One method of preparing an alkyl ester of (meth)acrylic acid is to react (meth)acrylic acid with an alkyl alcohol in the presence of a catalyst. Some useful catalysts are strongly acidic cation exchange resins (“SAC resins”). Historically, SAC resins have been available as one of two types: gel resins or macroporous resins. Historically, typical gel resins were made without the use of porogen and are made with relatively low level of crosslinking; while they tended to be effective when used as catalysts, they tended to have poor physical toughness. Historically, typical macroporous resins were made with porogen and with relatively high level of crosslinking; they tended to be less effective when used as catalysts, but they tended to have good physical toughness. Thus, in the past, when a catalyst was desired, it was necessary to choose between gel resins and macroporous resins; that is, it was necessary to sacrifice either catalytic effectiveness or physical toughness.

#U.S. Pat. No. 5,866,713 discloses a method of preparing a (meth)acrylic acid ester. The method of U.S. Pat. No. 5,866,713 involves reacting (meth)acrylic acid with a C1-3 alcohol in the presence of a strongly acidic ion exchange resin. None of the resins disclosed by U.S. Pat. No. 5,866,713 has both a high level of catalytic effectiveness and a high level of physical strength. It is desired to provide a resin that has both a high level of catalytic effectiveness and a high level of physical strength.

#The following is a statement of the invention.

#Aqueous suspension polymerization was conducted using standard techniques, using 300 g of aqueous phase (water and suspending agents), 270 g of organic phase (monomers (styrene (STY) and Divinyl Benzene (DVB), initiators and porogen). The porogen used was methyl isobutyl carbinol (MIBC) in 34-40% based on total organic phase. Typical mixing, time and temperatures were used for the synthesis steps. After polymerization, the resulting polymer beads were washed with excess water and oven dried. Sulfonation of this resin was performed by standard sulfonation methods. The result is a crosslinked poly(STY-co-DVB) sulfonated resin.

#Some commercial resins were obtained in the sodium form. Prior to use as catalyst, these resins were converted to acid form as follows. 70 mL of resin was charged to a column along with deionized water. 1 liter solution of HCl 4% (by weight) was downflowed at 250 mL/h, followed by 2 liter of deionized water at 250 mL/h. Final pH of effluent was confirmed to be within 2-3.

#60 mL of catalyst in acid form were washed with 600 mL deionized water in a column with downflow process at 120 mL/hour. The catalyst was dried in a Buchner funnel to remove excess water and charged again into the column with MeOH. 2000 mL of methanol were flowed through the column in downflow process at 120 mL/hour. At the end of the process the catalyst was transferred as slurry in methanol to a graduated cylinder and the volume registered. The catalyst was then dried in a Buchner funnel to remove excess methanol. 150.0 g of Methanol were weighed and used to charge the catalyst and methanol to the 500 mL reactor. 40 mg of inhibitor, MEHQ, was weighed and charged to the reactor and stirred at 300 rpm for all the runs. The reactor was heated to 60° C. within 30 minutes. 40 g of Methacrylic Acid (GMAA) was charged to the reactor and the reaction held at 60° C. for 6 hours. 1 mL samples for gas chromatography were taken at the following reaction times: 10 seconds, 1 hour, 2 hour, 3 hour and 4 hour. In situ infrared measurements were started before the GMAA was charged and samples measured every 30 seconds during the 4 hour run. In situ Infrared measurements were used to follow kinetics for the runs and estimate the reaction rate observed constants.