JP2010099573A - Strongly acidic cation exchange resin for manufacturing methacrylic acid ester - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a (meth)acrylic acid ester which is industrially efficient, and to provide a strongly acid cation exchange resin using the same. <P>SOLUTION: The strongly acid cation exchange resin for manufacturing a (meth)acrylic acid ester satisfies the following (A), (B) and (C): (A) the surface area measured by a nitrogen adsorbing method is 2 m<SP>2</SP>/g or less; (B) the degree of crosslinking is ≥2 wt.% to ≤7.5 wt.%; (C) the degree of swelling is 2 or less; (wherein the degree of swelling is expressed by the expression that the volume of the resin swelled when a methyl methacrylate monomer is added to the strongly acid cation exchange resin and the resin is left to stand for 72 h in a water bath of 70°C/the volume of the strongly acid cation exchange resin regenerated into an H shape before being swelled). <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a strongly acidic cation exchange resin for producing a (meth) acrylic acid ester, and a method for producing a (meth) acrylic acid ester using a strongly acidic cation exchange resin. In the present specification, (meth) acrylic acid ester (hereinafter sometimes referred to as “MMA”) is a general term for acrylic acid ester and methacrylic acid ester.

As a catalyst for producing (meth) acrylic acid ester by esterification reaction of (meth) acrylic acid and alcohol, strong acid cation exchange resins are widely used. As strong acid cation exchange resins, porous type (porous type) and gel type (gel type) are known.
Patent Documents 1 and 2 describe that a porous strong acidic cation exchange resin can be suitably used as a catalyst for producing the (meth) acrylic acid ester.

Patent Documents 3 and 4 describe examples in which a gel-type strongly acidic cation exchange resin is used as a production catalyst for the (meth) acrylic acid ester.
JP-A-10-279523 Japanese Patent Laying-Open No. 2005-267331 JP 2002-88019 A JP 2003-206319 A

Conventionally known porous cation exchange resins as described in Patent Documents 1 and 2 have low catalytic activity and durability even when they are used for the production of industrial (meth) acrylic acid esters. There was the fault that the nature was also low.
In addition, conventionally known gel type cation exchange resins as described in Patent Documents 3 and 4 have a problem of low durability.

  As a result of intensive studies to solve the above-mentioned problems, the present inventor has a porous type as a cause of low durability of conventionally known cation exchange resins as described in Patent Documents 1 to 4 above. It has been found that not only the gel type but also the tendency to swell during use, and that the higher the swellability, the higher the possibility that the ion exchange resin will be crushed and it cannot withstand long-term use. Then, paying attention to this point, a strongly acidic cation exchange resin having low swelling property and a production method thereof were found, and the present invention was completed.

That is, the gist of the present invention resides in the following (1) to (5).
(1) A strongly acidic cation exchange resin for production of (meth) acrylic acid ester, characterized by satisfying the following (A), (B), and (C).
(A) Surface area measured by nitrogen adsorption method is 2 m ² / g or less (B) Crosslinking degree is 2% by weight or more and 7.5% weight or less (C) Swelling degree is 2 or less (the swelling) The degree is a value represented by the following formula (I).
(Volume after adding methyl methacrylate monomer to the strong acid cation exchange resin and allowing it to swell by standing in a constant temperature bath at 70 ° C. for 72 hours) / (the strong acid cation regenerated to form H) Volume before exchange resin swelling))) Formula (I))
(2) The strongly acidic cation exchange resin for production of (meth) acrylic acid ester according to (1), wherein the moisture content is 35% by weight or more.
(3) A strongly acidic cation exchange resin for producing a (meth) acrylic acid ester according to (1) or (2), which comprises a polymerization inhibitor.
(4) The production of a (meth) acrylic acid ester according to any one of (1) to (3), comprising a step of sulfonation using sulfuric acid containing 0.1% by weight or more of olium Of producing strongly acidic cation exchange resin for use in a process.
(5) A method for producing a (meth) acrylic acid ester, comprising using the strongly acidic cation exchange resin according to any one of (1) to (4).

The strongly acidic cation exchange resin of the present invention is excellent in durability and can be used for a reaction for producing a (meth) acrylic acid ester over a long period of time.
Furthermore, if the strong acid cation exchange resin of this invention is used, a (meth) acrylic acid ester can be manufactured with a high yield.

Hereinafter, embodiments of the present invention will be described in detail. However, the present invention is not limited to the following embodiments, and various modifications can be made within the scope of the gist of the present invention.
The present invention relates to a strongly acidic cation exchange resin for producing a (meth) acrylic acid ester and a method for producing a (meth) acrylic acid ester using the same.
[Cation exchange resin]
The cation exchange resin of the present invention satisfies the following (A), (B), and (C).
(A) Surface area measured by nitrogen adsorption method is 2 m ² / g or less (B) Crosslinking degree is 2% by weight or more and 7.5% weight or less (C) Swelling degree is 2 or less (the swelling) The degree is a value represented by the following formula (I).
(Volume after adding methyl methacrylate monomer to the strong acid cation exchange resin and allowing it to swell by standing in a constant temperature bath at 70 ° C. for 72 hours) / (the strong acid cation regenerated to form H) Volume before exchange resin swelling))) Formula (I))
(A) Surface area The cation exchange resin of the present invention is characterized by a relatively small surface area.

The cation exchange resin of the present invention has a dry surface area of usually 2 m ² / g or less, preferably 1 m ² / g or less, particularly preferably 0.2 m ² / g or less. When a cation exchange resin having a small surface area is used, the yield of production of (meth) acrylic acid ester tends to be improved, and is most preferably 0.1 m ² / g or less. If the surface area of the cation exchange resin is too large, the yield tends to decrease.

The surface area is measured by a nitrogen adsorption method. For example, after the cation exchange resin is vacuum-dried, the surface area can be measured using a flow sorb type 2300 manufactured by Micrometrics.
(B) Degree of crosslinking The degree of crosslinking of the cation exchange resin of the present invention is usually 2% by weight or more, preferably 2.5% by weight or more, more preferably 3% by weight or more, and usually 7.5% by weight. Hereinafter, it is preferably 7% by weight or less, more preferably 6% by weight or less, and still more preferably 5.5% by weight or less. When the degree of crosslinking is too high, the yield of (meth) acrylic acid ester production tends to decrease. On the other hand, if the degree of cross-linking is too low, the yield of (meth) acrylic acid ester production tends to decrease, and furthermore, the pressure loss when passing through the liquid is large, and there are process restrictions for long-term use. May increase.

  Catalytic activity tends to largely depend on the degree of cross-linking of the resin, and the degree of cross-linking is low, that is, the cation exchange resin having a gentle three-dimensional network structure of the gel is more likely to diffuse the substrate inside the gel, The catalytic activity tends to be high. In particular, when the cation exchange resin of the present invention is a gel type, if the degree of cross-linking is higher than 7.5%, the substrate is less likely to diffuse into the gel, and the catalytic activity tends to decrease.

  Further, when the cation exchange resin of the present invention is a porous type, precipitation solvents (for example, hydrocarbons (isododecane, dodecane, isooctane, heptanes), aromatic hydrocarbons (benzene, toluene, xylene), alcohols (Amyl alcohol, ethyl hexanol, octanol), those produced using polymers polymerized with ketones (methyl ethyl ketone, methyl isobutyl ketone, diisobutyl ketone)), the substrate is difficult to diffuse inside the resin, the catalytic activity tends to decrease It is in. In the present invention, a resin having a three-dimensional crosslinked structure in which micropores are developed, such as a gel resin, is preferable to a porous resin synthesized with a precipitation solvent.

The degree of crosslinking can be calculated by the content of a polyfunctional vinyl compound (for example, divinylbenzene) in a monomer that is a so-called crosslinking agent, which is used as a raw material when a cation exchange resin is produced by a polymerization reaction. it can.
(C) Swelling degree The cation exchange resin of the present invention is characterized by a low degree of swelling in the evaluation of swelling property.

The degree of swelling means that methyl methacrylate monomer was added to the ion exchange resin with respect to the volume of the H-type strongly acidic cation exchange resin before swelling, and the mixture was allowed to stand for 72 hours in a constant temperature bath at 70 ° C. It shows the ratio of the volume after, and is a value represented by the following formula (I). (Volume after adding methyl methacrylate monomer to the strong acid cation exchange resin and allowing it to swell by standing in a constant temperature bath at 70 ° C. for 72 hours) / (the strong acid cation regenerated to form H) Volume before exchange resin swelling))) ... Formula (I)
The degree of swelling of the cation exchange resin of the present invention is usually 2 or less, preferably 1.5 or less, particularly preferably 1.3 or less. When a cation exchange resin having a small degree of swelling is used, durability tends to be improved, and long-term use is possible. On the other hand, when a cation exchange resin having a high degree of swelling is used, the volume tends to increase due to the resin swelling when used for a long period of time, and the durability tends to decrease.
A cation exchange resin having a low degree of swelling as in the present invention can be obtained by controlling polymerization conditions and sulfonation conditions.

  In contrast, conventionally known ion exchange resins tend to swell as the polymerization reaction proceeds when the cation exchange resin is immersed in a solution containing a raw material such as methyl methacrylate monomer and heated. It is in. The particle size of the cation exchange resin is usually about 0.7 mm, but when it swells, it becomes about 1 mm to 3 mm. The cause of this swelling is considered as follows. For example, in the case of using a methyl methacrylate monomer (hereinafter sometimes referred to as “MMA monomer”) as a raw material, in the polymerization reaction, not only MMA in the raw material solution but also diffuses inside the resin. Polymerization of MMA proceeds, but at this time, MMA present in the raw material solution tends to proceed faster than MMA diffused inside the resin. As polymethyl methacrylate (hereinafter sometimes referred to as “pMMA”) is polymerized in the raw material solution, pMMA tends to hardly diffuse inside the resin. Can be diffused into the resin. As the polymerization of MMA progresses inside the resin, the resin itself becomes easy to absorb alcohol by increasing the molecular weight and further decreasing the polarity. As a result, the polymerization reaction of MMA inside the resin is promoted, and it is presumed that the phenomenon that the resin swells to the extent that it explodes as shown in FIG. 4 is observed.

At this time, since the cation exchange resin of the present invention can withstand the swelling pressure, it is considered that the resin is not easily crushed and the durability is improved as shown in FIG. In the present invention, it is important to create an environment in which MMA is difficult to polymerize inside the resin and to form a gel structure that can withstand the swelling pressure even if pMMA is polymerized inside the resin.
The degree of swelling can be specifically measured by the following method. For the evaluation test of swellability, methyl methacrylate monomer (MMA monomer) subjected to the following treatment in advance is used. Methyl methacrylate (manufactured by Wako Pure Chemical Co., Ltd., special grade reagent), 100 g of methoquinone (containing 50 ppm of hydroquinone methyl ether) were packed in a glass column and vacuum dried at 50 ° C. for 8 hours to alumina (Merck alumina 60 mesh product). By passing the solution through SV2, methoquinone, which is a polymerization inhibitor, is removed, and the entire amount of MMA monomer is recovered. The obtained solution is purified by distillation under reduced pressure under conditions of 60 mmHg and 36 ° C. Specifically, a Claisen adapter is attached to a 500 ml eggplant flask (specifically, a Y-shaped distillation head is attached and condensed with a Jimlow condenser. A coolant at 5 ° C. is circulated in the condenser. ), The monomer solution is purified by distillation under reduced pressure under conditions of 60 mmHg and 36 ° C. The first train leaves 10% of the charged weight, and the remaining amount of the kettle also remains 10%. After distillation, it is preferably stored in a refrigerator at −20 ° C. and used within 3 days.

As the solution used for the evaluation of the swellability, an MMA monomer solution obtained by mixing 40% by weight of the MMA monomer purified as described above and 60% by weight of methanol is used.
By passing 2N-HCl at 10 BV through the cation exchange resin as the specimen, the sample is regenerated into H form, and adhering moisture is removed with a centrifuge. 20.0 ml of this cation exchange resin (draining resin) is weighed with a graduated cylinder, put into a 200 ml pressure-resistant glass container (made by pressure-resistant glass industry), and 100 g of the MMA monomer solution (including methanol) is added thereto. . After pressurizing nitrogen gas into the pressure-resistant glass container to 0.5 MPa, the operation of returning to atmospheric pressure is repeated three times to replace the pressure container with nitrogen gas. Subsequently, it heats for 30 minutes at 30 degreeC, and seals a pressure-resistant glass container after that. This pressure-resistant glass container is left still in a constant temperature bath at 70 ° C. After 72 hours, the degree of swelling was calculated by measuring the volume of the cation exchange resin in the gelled polymethyl methacrylate and calculating how many times it swelled with respect to 20.0 ml before the test. can do.
(D) Water content The cation exchange resin of the present invention is characterized by a low water content.

When the cation exchange resin of the present invention is a gel type, the water content when the ionic form is H form is usually 85% by weight or less, preferably 80% by weight or less, particularly preferably 75% by weight. In addition, it is usually 40% by weight or more, preferably 50% by weight or more, and more preferably 55% by weight or more.
When the cation exchange resin of the present invention is a porous type, the water content when the ionic form is H form is usually 80% by weight or less, preferably 75% by weight or less, particularly preferably 70% by weight. In addition, it is usually 35% by weight or more, preferably 45% by weight or more, and more preferably 50% by weight or more.

In the (meth) acrylic acid ester production process, water is generated as a by-product, and therefore, when a cation exchange resin having a high water content is used, the reaction tends to be suppressed. On the other hand, even if the water content is too small, the catalytic activity tends to decrease.
The moisture content can be measured, for example, by the following procedure.
<Measurement of moisture content>
Contact the cation exchange resin that is the analyte with an aqueous hydrochloric acid solution to regenerate the cation exchange group, then dehydrate it with an appropriate device such as a centrifuge, and weigh the appropriate amount of the dehydrated cation exchange resin. . The weighed cation exchange resin is further vacuum-dried, and the mass of the vacuum-dried cation exchange resin is measured. Then, the water content of the cation exchange resin can be calculated from the mass after dehydration and the mass after vacuum drying. In addition, the moisture in the resin can be directly measured with a Karl Fischer moisture meter.
(E) Particle size The cation exchange resin of the present invention has a particle size of usually 100 μm or more, preferably 200 μm or more, more preferably 300 μm or more, and usually 1000 μm or less, preferably 800 μm or less, more preferably 700 μm or less. is there. If the particle size is too large, the cation exchange resin tends to be crushed, and particularly when the cation exchange resin is put into the reactor and the raw material is passed in an upward flow, the cation exchange resin particles When the diameter is large, the cation exchange resin is difficult to flow, and reaction heat tends to accumulate. If the particle size is too small, the pressure loss is large and the raw material tends to be difficult to pass.

The particle size of the cation exchange resin is actually shrunk by the raw material solution, but in the present invention, the value obtained by regenerating the H shape and measuring the weight average particle size in water is the particle size of the cation exchange resin. It is defined as
Measurement of the particle size of the cation exchange resin, that is, the particle size weight average particle size is performed, for example, by the following procedure.

<Weight average particle size measurement method>
The sieves having a sieve mesh diameter of 1180 μm, 850 μm, 710 μm, 600 μm, 425 μm, and 300 μm are stacked so that the sieve mesh diameter decreases as it goes downward. The stacked sieve is placed on a vat, and about 100 mL of cation exchange resin is placed in the 1180 μm sieve stacked on the top.

Gently pour water onto the resin from a rubber tube connected to tap water and screen the small particles downward. The cation exchange resin remaining in the 1180 μm sieve is further screened for small particles by the following method. That is, water is filled up to a depth of about 1/2 of another bat, and a 1180 μm sieve is repeatedly shaken by giving up and down and rotational motion in the bat, and small particles are sieved.
The small particles in the vat are returned to the next 850 μm sieve, and the cation exchange resin remaining on the 1180 μm sieve is collected in another vat. If the cation exchange resin is clogged in the sieve, place the sieve on the vat in reverse, closely contact the rubber tube connected to tap water, and drain the cation exchange resin clogged with strong water. . The cation exchange resin taken out is transferred to a bat where the cation exchange resin remaining on the 1180 μm sieve is collected, and the volume is measured with a graduated cylinder. Let this volume be a (mL). The cation exchange resin that passed through the 1180 μm sieve was subjected to the same operation for the 850 μm, 710 μm, 600 μm, 425 μm, and 300 μm sieves, and the volume b (mL), c (mL), and d (mL) using a graduated cylinder. E (mL) and f (mL) are obtained, and finally the volume of the resin that has passed through the 300 μm sieve is measured with a graduated cylinder and is set as g (mL).

V = a + b + c + d + e + f + g, a / V × 100 = a ′ (%), b / V × 100 = b ′ (%), c / V × 100 = c ′ (%), d / V × 100 = d ′ ( %), E / V × 100 = e ′ (%), f / V × 100 = f ′ (%), g / V × 100 = g ′ (%).
From the above a ′ to g ′, the residual amount cumulative (%) of each sieve is taken on one axis, and the diameter (mm) of the sieve mesh is taken on the other axis, and this is plotted on the logarithmic probability paper. Take 3 points in the order of the remaining amount, draw a line that satisfies these 3 points as much as possible, obtain the diameter (mm) of the sieve mesh corresponding to 50% of the accumulated residue from this line, and calculate the weight average The particle size.

In addition, the calculation method of the said weight average particle diameter is described, for example in Mitsubishi Chemical Corporation ion exchange resin division "Diaion I basics edition" 14th edition (September 1, 1999) pp.139-141. This is a known calculation method.
The uniformity coefficient of the cation exchange resin is usually around 1.5 when manufactured by suspension polymerization, but the uniform droplets are generated so that the particle size is uniform. When the polymer is produced by the method of polymerizing, the uniformity coefficient is about 1.0 to 1.1. In the present invention, any resin can be used. When used in a batch reaction, a batch reaction in a suspended state, or a flow reaction using a fixed bed, the particle size is preferably uniform. The cation exchange resin preferably has a uniformity coefficient of 1 or more and 1.5 or less, preferably 1.3 or less, more preferably 1.2 or less, and even more preferably 1.1 or less. When a cation exchange resin having a uniform particle size is used, the pressure loss tends to be low when liquid is passed in a downward flow. In addition, when a cation exchange resin having a uniform particle size is passed in an upward flow, the backwashing development rate tends to be small and the spread of the particles tends to be small. The pressure loss tends to be small, which is preferable.
(F) Neutral salt decomposition capacity The cation exchange resin of the present invention has a neutral salt decomposition capacity (meq / ml) per volume of usually 0.5 meq / ml or more and 2.5 meq / ml or less. The cation exchange resin of the present invention preferably has a neutral salt decomposition capacity per volume within the above range. In general, the higher the degree of cross-linking, the higher the neutral salt decomposition capacity per volume. However, even if the neutral salt decomposition capacity per volume is high, if the degree of cross-linking is high, (meth) acrylic acid is a substrate. And alcohol are less likely to diffuse, and the catalytic activity tends to decrease.

Further, the neutral salt decomposition capacity (meq / g-dry resin) per dry weight of the cation exchange resin of the present invention generally has a low degree of crosslinking since the sulfonation reaction is difficult to proceed as the degree of crosslinking increases. Tend to be higher. Specifically, 4.0 meq / g-dry resin or more is usually preferable.
The neutral salt decomposition capacity is defined as a strongly acidic cation exchange capacity and represents the content of sulfonic acid groups. This neutral salt decomposition capacity is measured, for example, by the following procedure.

<Neutral salt decomposition capacity measurement method>
The neutral salt decomposition capacity of the cation exchange resin of the present invention is analyzed and measured by the following method.
First, a cation exchange resin is packed in a column, and a 2N-HCl aqueous solution having a volume 25 times the resin volume is passed through the column to convert the counter ion to H-form and washed with demineralized water. Take 10.0 ml of this resin, fill a glass column, and wash thoroughly with demineralized water until the washing filtrate is neutral. Thereafter, a 25% volume of 5% NaCl aqueous solution is passed through to collect all the effluent. The effluent is titrated with 1N hydrochloric acid to measure the neutral salt decomposition capacity. This is converted per 1 ml of resin, and the neutral salt decomposition capacity per volume is calculated. On the other hand, 10.0 ml of the resin regenerated into the H shape is taken, drained with a centrifuge, and the weight of the resin after draining is measured. This resin is dried in a vacuum dryer at 50 ° C. for 8 hours, and the weight of the resin after drying is measured. The neutral salt decomposition capacity per dry weight is calculated from the weight in the drained state and the weight after drying.
(G) Chemical structure An ion exchange resin can be defined as a solvent-insoluble spherical or powdery plastic having an ion exchange group.
The plastic material is generally made of a styrene resin and is formed of a cross-linked copolymer of styrene divinylbenzene, and an ion exchange group is fixed to the polymer by a chemical bond.

The ion exchange group possessed by the cation exchange resin of the present invention is not particularly limited as long as it has the properties described above, but is preferably strongly acidic. Specific examples include a sulfonic acid group, a perfluoroalkylsulfonic acid group, and a phosphoric acid group, and among them, a sulfone group is preferable. More specifically, it is preferably a sulfonated styrene-divinylbenzene copolymer.
[Method for producing cation exchange resin]
The cation exchange resin of the present invention can be adjusted by separately adjusting the aqueous phase and the oil phase and polymerizing the aqueous phase and the oil phase. More specifically, a mixture (oil phase) of a bifunctional unsaturated monomer having a crosslinking action containing a polymerization initiator is added to an aqueous medium (aqueous phase) in which a dispersant is dissolved, and the mixture is stirred and suspended. This is done by forming a liquid and then holding it at a predetermined polymerization temperature.
<Water phase>
Water can be used as the aqueous medium.

  As the dispersant, xanthan gum, polydiallyldimethylammonium chloride, polyacrylic acid and its salt, polyacrylamide, hydrolyzate of styrene-maleic anhydride copolymer and its salt, carboxymethylcellulose, hydroxyalkylcellulose, methylcellulose, ethylcellulose, Conventional materials such as polyvinyl alcohol and gelatin can be used.

Moreover, you may add buffer salts, such as an alkali and a borate, in order to maintain pH appropriately as needed.
<Oil phase>
Examples of the bifunctional unsaturated monomer having a crosslinking action include aromatic monomers such as divinylbenzene, divinyltoluene, divinylxylene, divinylnaphthalene and divinylethylbenzene, and aliphatic single monomers such as ethylene glycol poly (meth) acrylate. A polymer or the like can be used. If necessary, two or more of these solutions may be used in combination.

  In the case of a porous resin, it is preferable to use a precipitation solvent in addition to the bifunctional unsaturated monomer in order to make it porous. Specific examples of the precipitation solvent include hydrocarbons (isododecane, dodecane, isooctane, heptanes), aromatic hydrocarbons (benzene, toluene, xylene), alcohols (amyl alcohol, ethylhexanol, octanol), ketones. (Methyl ethyl ketone, methyl isobutyl ketone, diisobutyl ketone) and the like can be used.

  Examples of the polymerization initiator include ketone peroxide, diacyl peroxide, peroxyester, peroxycarbonate, acetylacetone peroxide, isobutyl peroxide, lauroyl peroxide, benzoyl peroxide, succinic acid peroxide, octanoyl peroxide, Organic peroxides such as stearoyl peroxide, azo compounds such as azobisisobutyronitrile, azobisvaleronitrile, t-butylperoxyacetate, t-butylperoxyisobutyrate, t-butylperoxy-2- Ethyl hayanoate, t-butyl peroxybenzoate, dicumyl peroxide, di-t-hexyl peroxide, t-butyl peroxyisopropyl monocarbonate, di-t-hexyl pero It can be used aliphatic peroxy esters, such as benzoate.

The amount of radical polymerization initiator (hereinafter sometimes referred to simply as “polymerization initiator”) depends on the type of polymerization initiator and the above-mentioned bifunctional unsaturated monomer (hereinafter simply referred to as “raw material monomer”). And may vary depending on the type and composition ratio of the precipitation solvent for porosity, but it is generally not determined, but is usually 0.03% by weight or more, preferably 0.1%, based on the raw material monomer. % By weight or more, usually 5% by weight or less, preferably 2% by weight or less, more preferably 1.5% by weight or less. If the amount of the polymerization initiator used is less than 0.03% by weight, the polymerization may not substantially proceed. In addition, if the amount of the polymerization initiator used exceeds 5% by weight, it is not economical and, in some cases, foams during the polymerization, the molecular weight of the composition obtained by the polymerization becomes extremely small, or the initiator remains. Or the strength of the resin may decrease.
<Polymerization reaction>
The ratio (volume ratio) between the mixture of raw material monomers and the aqueous medium is generally 1:10 to 1: 1, and the aqueous medium is preferably increased.

The polymerization reaction is usually performed by heating a suspension obtained by mixing an oil phase and an aqueous phase while stirring.
The polymerization temperature and the polymerization time cannot be defined unconditionally because they vary depending on the type of polymerization initiator used and the amount used, but the polymerization temperature is usually 30 ° C or higher, preferably 50 ° C or higher, and usually 200 ° C or lower. Preferably, it is the range of 150 degrees C or less. The polymerization time is usually 0.5 hours or longer, preferably 2 hours or longer, and usually 24 hours or shorter, preferably 12 hours or shorter.

This polymerization reaction can be performed under normal pressure or under conditions of about 1.5 to 5 atm.
In the present invention, the polymerization method is not particularly limited, but in order to produce a spherical copolymer, the polymerization reaction is carried out in water or another aqueous medium while keeping the monomer mixture and the polymerization initiator in a suspended state by stirring. .
After completion of the polymerization reaction, it is preferable to perform washing and drying as appropriate.
<Introduction of cation exchange groups>
The cation exchange group to be introduced is preferably a sulfone group. Examples of the reagent used for introducing the sulfone group include sulfuric acid (preferably concentrated sulfuric acid), fuming sulfuric acid, chlorosulfuric acid, and the like. Among these, concentrated sulfuric acid is preferable. The specific concentration of concentrated sulfuric acid is usually 95% by weight or more, preferably 98% by weight or more, and more preferably 100% by weight or more.

  Among them, it is preferable to use sulfuric acid containing olium. In the case of a gel-type cation exchange resin, it is preferable to use sulfuric acid containing 0.1% by weight or more, preferably 1% by weight or more, and more preferably 5% by weight or more. In the case of a porous type cation exchange resin, it is preferable to increase the content of olium as compared with the case of a gel type, specifically, 1% by weight or more, preferably 3% by weight or more, more preferably 5% by weight. It is preferable to use sulfuric acid containing at least 7% by weight, particularly preferably 7% by weight or more.

  When a cation exchange resin produced using sulfuric acid containing olium is used in the introduction of a cation exchange group, the neutral salt decomposition capacity (meq / g-dry resin) per dry weight increases, This is because the ion exchange resin is less likely to swell. In particular, in the case of a porous resin, a higher olium concentration at the time of introducing a cation exchange group is preferred because the degree of swelling tends to decrease and durability is improved. For this reason, it is not always necessary to use sulfuric acid in porous type resins, and in order to increase the concentration of oleum, it is usually necessary to reduce the amount of solvent used in the sulfonation reaction, or to add a high concentration oleum solution without adding a solvent. May be used for sulfonation.

Instead of the above-mentioned sulfuric acid containing olium, sulfuric acid containing olium and sulfuric acid having a concentration of 100% or less (for example, sulfuric acid having a concentration of 98% or sulfuric acid having a concentration of 95%) are mixed for sulfonation. You can also.
As the solvent used for introducing the cation exchange group, nitrobenzene, chlorobenzene, and the like can be used in addition to halogenated hydrocarbons such as nitromethane, methylene chloride, ethylene dichloride, chloroform, dichloropropane, and the like. Alternatively, the cation exchange group can be introduced without a solvent.

The introduction of the cation exchange group can be performed by reacting the above-described reagent (such as concentrated sulfuric acid) with the polymer obtained by the above-described polymerization reaction. At this time, the amount of the reagent (concentrated sulfuric acid or the like) added (including the solvent) is preferably an amount enough to immerse the polymer.
The reaction temperature for introducing the cation exchange group is usually 30 ° C. or higher, preferably 50 ° C. or higher, and the reaction time is 1 hour or longer, preferably 2 hours or longer, and usually 24 hours or shorter, preferably 12 It is less than time, More preferably, it is less than 8 hours.
<Addition of polymerization inhibitor>
It is preferable to add a polymerization inhibitor to the cation exchange resin because an organic contamination by the polymer of the (meth) acrylic acid derivative is suppressed on the resin surface or inside the resin.

  Polymerization inhibitors include hydroquinone, hydroquinone monomethyl ether, t-butylcatechol, phenothiazine derivatives (specifically, phenothiazine, bis- (α-methylbenzyl) phenothiazine, 3,7-dioctylphenothiazine, bis- (α-dimethyl). Benzyl) phenothiazine, etc.), TEMPO or a derivative thereof (TEMPO is a compound having piperidine-1-oxyl, specifically 2,2,6,6-tetramethyl-4 -Hydroxypiperidine-1-oxy 2,2,6,6-tetramethylpiperidine-1-oxy, etc.), DPPH (diphenylpicrylhydrazyl), nitroso compounds (specifically, N-nitroso- N-phenyl-N-hydroxyamine, nitrosodiphenylamine , Dimethylnitrosamine, isoamyl nitrite, etc.) can be used. These polymerization inhibitors may be used in combination of two or more.

Among the above polymerization inhibitors, those having an amino group are preferable because of excellent polymerization inhibition ability, and more specifically, phenothiazine, methylene blue, 4-amino-TEMPO, and DPPH are particularly preferable.
Although the addition amount of a polymerization inhibitor changes with kinds, it is 10 ppm or more normally with respect to 1L of cation exchange resins, Preferably it is 50 ppm or more, and is 1% or less normally, Preferably it is 5000 ppm or less.
[Method for producing (meth) acrylic acid ester]
The production method of the present invention essentially uses the cation exchange resin of the present invention described above. If the cation exchange resin of the present invention is used, a known method can be used for other production conditions. For example, by supplying (meth) acrylic acid and alcohol as raw materials to a batch reactor equipped with a fixed bed or a stirrer filled with the cation exchange resin of the present invention, (meth) acrylic acid ester Can be manufactured.

In the case of producing in a fixed bed, the flow rate of the raw material is not particularly limited, but is usually 0.1 times or more, preferably 0.2 times or more, more preferably 0.2 times the strong acid cation exchange resin. The amount is twice or more, usually 10 times or less, preferably 5 times or less, more preferably 3 times or less.
When the reaction is carried out in a fixed bed, 30% to 95% of a strongly acidic cation exchange resin can be filled with respect to the volume of the reactor. The ratio of the packed bed height of the resin (with the resin naturally precipitated) to the tower diameter is usually 0.2 or more, preferably 0.5 or more, and usually 10 times or less.
The raw materials for the (meth) acrylic acid ester production reaction are (meth) acrylic acid and alcohols and / or esters (hereinafter sometimes simply referred to as “alcohols”).

As alcohols, methanol, ethanol, butanol, ethylene glycol, propylene glycol, butanediol, hexanediol, 2-ethylhexanol, methoxyethanol and the like can be used.
As the esters, methyl (meth) acrylate, ethyl (meth) acrylate, or the like can be used. Among them, it is preferable to use an ester having 4 or less carbon atoms such as methyl (meth) acrylate. If these esters are used as raw materials, a (meth) acrylic acid ester can be synthesized by a transesterification reaction.

  When (meth) acrylic acid ester is produced by bringing these raw materials into contact with a cation exchange resin, the composition ratio of these raw materials is usually 0 by molar ratio of alcohols to (meth) acrylic acid. .1 or more, preferably 0.3 or more, and usually 10 or less, preferably 5 or less, more preferably 3 or less. If this ratio is too large or too small, the productivity of the target product tends to decrease.

  In addition to the above raw materials, organic solvents other than the raw materials can be added. Thereby, it is also possible to produce while removing the low-boiling point alcohol and water. Examples of the organic solvent to be added include hexane, heptane, cyclohexane, octane, isooctane, benzene, toluene, xylene and the like. The amount added is usually 0 to 10 times, preferably 0 to 3 times the amount of the raw material (meth) acrylic acid.

  The liquid flow direction of the raw material may be a downward flow or an upward flow. The liquid feed rate of the raw material is generally a space velocity with respect to the amount of the charged resin and is usually 0.1 or more, preferably 0.2 or more, and usually 10 or less, preferably 5 or less. When a raw material is passed in an upward flow with respect to a resin having a small particle size, the resin may float. When the flow rate of the raw material is increased, the raw material may be passed with the cation exchange resin fixed to the upper part of the reactor (with a lift bed).

  The temperature at which the raw material is brought into contact with the cation exchange resin is usually 25 ° C. or higher, preferably 40 ° C. or higher, and usually 140 ° C. or lower, preferably 120 ° C. or lower. When the reaction temperature is low, the reaction rate decreases and the productivity tends to deteriorate. On the other hand, if the reaction temperature is too high, the raw material (meth) acrylic acid and the product (meth) acrylic acid ester may polymerize and accumulate in the cation exchange resin, which also decreases the reaction rate. Can cause

Moreover, this reaction can be performed under normal pressure or conditions of 0.1 MPa to 1 MPa, although it varies depending on the type of raw material, composition ratio, and the like.
In addition, as a mode of manufacturing reaction, the method of supplying a raw material continuously, the method of manufacturing batchwise (batch type), etc. are mentioned. It is also possible to carry out the reaction in a batch reaction tank equipped with a distillation tower. When there are multiple batch reaction tanks, the distillation reaction is carried out while supplying (meth) acrylic acid on one side and alcohols on the other side. There is an advantage that it can be done.

  In addition, it can also be produced using a multi-stage reaction distiller (for example, a reaction distiller having 25 theoretical plates and having a 7-stage distiller in the upper part and a 3-stage distiller in the lower part). Specifically, a part of the reactive distiller (for example, 5 out of 10 stages) is filled with a strongly acidic cation exchange resin, and (meth) acrylic acid is placed on the upper stage of the reactive distiller filled with the resin. (Meth) acrylic acid ester can be synthesized by supplying a low-boiling alcohol such as methanol as a raw material to the lower stage of the reaction distiller filled with the resin and distilling under normal pressure or reduced pressure. .

Specific embodiments of the present invention will be described below in more detail with reference to examples. However, the present invention is not limited to these examples unless it exceeds the gist.
[Measurement method of physical properties]
The physical property value of the strongly acidic cation exchange resin and the yield of (meth) acrylic acid ester used in each example and comparative example described later can be measured and calculated by the following methods.
<Particle size>
The sieves having a sieve mesh diameter of 1180 μm, 850 μm, 710 μm, 600 μm, 425 μm, and 300 μm were stacked so that the sieve mesh diameter was decreased as it went downward. The stacked sieve was placed on a vat, and about 100 mL of cation exchange resin was put into the 1180 μm sieve stacked on the uppermost stage.

Water was gently poured onto the resin from a rubber tube connected to tap water, and the small particles were sieved downward. The cation exchange resin remaining in the 1180 μm sieve was further screened for small particles by the following method. That is, water was filled to a depth of about 1/2 of another bat, and a 1180 μm sieve was repeatedly shaken by applying up and down and rotating motions in the bat to screen out small particles.
The small particles in the vat were returned to the next 850 μm sieve, and the cation exchange resin remaining on the 1180 μm sieve was collected in another vat. If the cation exchange resin is clogged in the sieve, place the sieve in the vat reversely, closely contact the rubber tube connected to tap water, and take out the cation exchange resin clogged with a strong water flow. It was. The cation exchange resin taken out was transferred to a bat where the cation exchange resin remaining on the 1180 μm sieve was collected, and the volume was measured with a graduated cylinder. This volume was defined as a (mL). The cation exchange resin that passed through the 1180 μm sieve was subjected to the same operation for the 850 μm, 710 μm, 600 μm, 425 μm, and 300 μm sieves, and the volume b (mL), c (mL), and d (mL) using a graduated cylinder. , E (mL), f (mL) were obtained, and finally the volume of the resin that passed through the 300 μm sieve was measured with a graduated cylinder to obtain g (mL).

V = a + b + c + d + e + f + g, a / V × 100 = a ′ (%), b / V × 100 = b ′ (%), c / V × 100 = c ′ (%), d / V × 100 = d ′ ( %), E / V × 100 = e ′ (%), f / V × 100 = f ′ (%), g / V × 100 = g ′ (%).
From the above a ′ to g ′, the cumulative residual amount (%) of each sieve was taken on one axis, and the diameter (mm) of the sieve mesh was taken on the other axis, and this was plotted on logarithmic probability paper. Take 3 points in the order of the remaining amount, draw a line that satisfies these 3 points as much as possible, obtain the diameter (mm) of the sieve mesh corresponding to 50% of the accumulated residue from this line, and calculate the weight average The particle size (particle size of the cation exchange resin) was used.
<Moisture content>
Exactly 10.0 ml of cation exchange resin regenerated into H form using 10 times amount of 2N HCl aqueous solution was taken with a graduated cylinder and dehydrated with a centrifuge. The total amount of this resin was transferred to a weighing bottle, vacuum-dried at 50 ° C. for 8 hours, and the mass of the vacuum-dried cation exchange resin was measured. Then, the water content of the cation exchange resin was calculated from the mass after dehydration and the mass after vacuum drying.
<Neutral salt decomposition capacity>
Exactly 10.0 ml of the cation exchange resin regenerated into H form using 10 volumes of 2N HCl aqueous solution was taken with a graduated cylinder. This resin was packed in a column, and 25 times the amount of 5% NaCl aqueous solution was passed therethrough. All saline effluent was collected. By titrating the effluent with 1N-NaOH or 0.1N-NaOH, the neutral salt decomposition capacity was measured, and this was converted to 1 ml of resin to calculate the neutral salt decomposition capacity per volume.
10.0 ml of the resin regenerated in the H form was weighed, drained with a centrifuge, and the weight of the resin after draining was measured. This resin was dried with a vacuum dryer at 50 ° C. for 8 hours, and the weight of the resin after drying was measured. The neutral salt decomposition capacity per dry weight was calculated from the weight in the drained state and the weight after drying.
<Surface area>
Measurement was performed by a nitrogen adsorption method. Specifically, the cation exchange resin was vacuum-dried at 50 ° C. for 8 hours, and then the surface area was measured using a flowmetric 2300 model manufactured by Micrometrics.
<Degree of crosslinking>
The divinylbenzene content was calculated and listed as the degree of crosslinking.
<Swelling evaluation method>
As the methyl methacrylate monomer (hereinafter sometimes referred to as “MMA monomer”) used for the evaluation of the swellability, those subjected to the following treatment in advance were used. Methyl methacrylate (manufactured by Wako Pure Chemical Co., Ltd., special grade reagent), 100 g of methoquinone (containing 50 ppm of hydroquinone methyl ether) were packed in a glass column and vacuum dried at 50 ° C. for 8 hours to alumina (Merck alumina 60 mesh product). By passing the solution through SV2, methoquinone as a polymerization inhibitor was removed, and the entire amount of MMA monomer was recovered. The resulting solution was purified by distillation under reduced pressure under conditions of 60 mmHg and 36 ° C. Specifically, a Claisen adapter was attached to a 500 ml eggplant flask (specifically, a Y-shaped distillation head was attached and condensed with a Jimlow condenser. Coolant at 5 ° C was circulated in the condenser. The monomer solution was purified by distillation under reduced pressure under conditions of 60 mmHg and 36 ° C. The initial distillation left 10% with respect to the charged weight, and also left 10% by weight. After distillation, it was stored in a -20 ° C refrigerator and used within 3 days.

As a solution used for the evaluation of the swelling property, an MMA monomer solution in which 40% by weight of the MMA monomer purified as described above and 60% by weight of methanol were mixed was used.
By passing 2N-HCl at 10 BV through the cation exchange resin as the specimen, the sample was regenerated to H-form, and adhering moisture was removed with a centrifuge. 20.0 ml of this cation exchange resin (draining resin) is measured with a graduated cylinder and placed in a 200 ml pressure-resistant glass container (made by pressure-resistant glass industry), and 100 g of the MMA monomer solution (including methanol) is added thereto. It was. After pressurizing nitrogen gas into the pressure-resistant glass container to 0.5 MPa, the operation of returning to atmospheric pressure was repeated three times to replace the pressure container with nitrogen gas. Subsequently, it heated at 30 degreeC for 30 minute (s), and sealed the pressure-resistant glass container after that. This pressure-resistant glass container was allowed to stand in a constant temperature bath at 70 ° C. After 72 hours, the volume of the cation exchange resin in the gelled polymethyl methacrylate was measured. The degree of swelling was calculated by substituting the volume before swelling (20.0 ml) and the volume after 72 hours (after swelling) into the following formula (I).
(Volume after adding methyl methacrylate monomer to the strong acid cation exchange resin and allowing it to swell by standing in a constant temperature bath at 70 ° C. for 72 hours) / (the strong acid cation regenerated to form H) Volume before exchange resin swelling))) ... Formula (I)
<Evaluation in distribution reaction>
(Experimental device)
A SUS316 column (manufactured by 20 mmφ × 25 cm GL Science) was connected to a liquid chromatography pump (manufactured by Shimadzu Corporation, LC-6A) with an approximately 2 m SUS HPLC pipe. The column was packed with 75.0 ml of a cation exchange resin regenerated into H form in a water slurry state. A 1 m long SUS HPLC pipe was connected to the outlet of the column filled with the cation exchange resin to cool the reaction solution, and the effluent was received by a 100 ml graduated cylinder. An electronic balance was installed under the graduated cylinder so that the flow rate could be measured. Place the SUS column in a deep bath (diameter: 24 cm x depth: 44 cm; one three-motor is installed in the bath for vertical stirring) and place the SUS column vertically. The SUS column was immersed in demineralized water in the bottom bath. The deep bath was controlled by a mercury thermometer and a stirring blade connected to a three-one motor so that the internal temperature was 80.0 ° C. In addition, in order to cool a monomer liquid at the column outlet, a silicon tube through -5 ° C. brine was traced.
(Preparation of raw material solution)
Reagents used as raw materials for the reaction include methyl methacrylate, methacrylic acid, hydroquinone, methoquinone (4-methoxyphenol), phenothiazine (all above, Tokyo Chemicals), methanol (low water content 50 ppm or less, special products, Kishida Chemical) The methacrylic acid and methanol were prepared so as to be a solution containing 2.0 mol of methanol with respect to 1.0 mol of methacrylic acid in a composition ratio. Specifically, in addition to 860.3 g of methacrylic acid and 640.7 g of methanol, three kinds of polymerization inhibitors of 0.751 g of hydroquinone, 0.762 g of methoquinone and 0.765 g of phenothiazine were added and dissolved by stirring at room temperature. did.
(Pretreatment of cation exchange resin)
The SUS column was packed with the cation exchange resin regenerated into the H form. Subsequently, 150 ml of special grade methanol (Kishida Chemicals anhydrous methanol) was passed in an upward flow at a flow rate of SV2, whereby the cation exchange resin was replaced with methanol. When water is replaced with methanol, the cation exchange resin tends to shrink, but this was also evaluated as it is as the ability of the resin. Further, 150 ml of the raw material solution prepared as described above (that is, a mixed solution of methacrylic acid and methanol) is passed upward at a flow rate of SV2, thereby replacing the cation exchange resin with the raw material solution. did.
(MMA synthesis reaction and its analysis)
The raw material solution was passed through the SUS column in an upward flow at a flow rate of 75.0 g / hour with respect to 75.0 ml of resin (that is, at a flow rate of SV1). The SV (space velocity) is displayed based on the volume at the time of preparation.

As described above, the volume of the cation exchange resin when charged was 75 ml in a water slurry state, but when the raw material solution was replaced, the cation exchange resin contracted to about 65 ml to 70 ml (depending on the resin).
The solution flowing out to the graduated cylinder was sampled every 30 minutes or every hour. Of course, the raw material solution and the reaction solution did not become viscous and liquid passage was not disabled.

  The sampled solution was evaluated by gas chromatography analysis. Specifically, a capillary column (HP-5) (inner diameter 0.2 mmφ × 0.33 μm × 50 m column) is attached to a gas chromatography device (Agilent 6850 series) and 1.0 μl of the sample solution is attached to this column. Were injected directly at a split ratio of 200/1 and analyzed with a FID detector. The MMA content was analyzed from the calibration curve, and the yield was calculated.

In any of the Examples and Comparative Examples, the yield of MMA reached an equilibrium state after 2 hours from the start of the reaction.
<Evaluation by batch reaction (dehydration system)>
(Preparation of raw material solution)
426.4 g of methacrylic acid (Tokyo Chemicals) and 318.5 g of methanol (Kishida Chemical, anhydrous) were added (methanol and methacrylic acid were 2: 1 (molar ratio)), and further. As a polymerization inhibitor, 0.371 g of hydroquinone (Tokyo Chemicals), 0.369 g of methoquinone (p-methoxyhydroquinone) (Tokyo Chemicals), and 0.364 g of phenothiazine (Tokyo Chemicals) were added and dissolved to prepare a raw material solution. did. The phenothiazine dissolved when stirred at room temperature for about 10 minutes.
(Pretreatment of cation exchange resin)
10NV of 2N-HCl was passed through the cation exchange resin in advance to regenerate the H form. 20.0 ml of this cation exchange resin was weighed with a graduated cylinder and drained with a centrifuge. 20.0 ml of the cation exchange resin drained in this manner was placed in a 300 ml Erlenmeyer flask and vacuum dried using a vacuum dryer at 50 ° C. for 12 hours.
(MMA synthesis reaction and its analysis)
The raw material solution obtained as described above was heated by immersing it in a shaker that had been heated to 50.0 ° C. in advance. 50.0 g of the raw material solution heated to 50 ° C. is added to the above Erlenmeyer flask (including cation exchange resin) and shaken at 120 spm (stroke length: 4 cm) using a constant temperature shaker (set temperature: 50.0 ° C.). did. The shaking speed of 120 spm is a shaking speed at which the cation exchange resin can maintain a fluid state.

Every 2 hours from the start of the reaction, 1 ml of the supernatant of the flask was sampled with a pipette. The solution after 8 hours was sampled and subjected to gas chromatography analysis under the same conditions as in the above <Evaluation by flow reaction>.
<Evaluation by batch reaction (draining system)>
(Preparation of raw material solution)
428.65 g of methacrylic acid (Tokyo Chemicals) and 319.11 g of methanol (Kishida Chemical, anhydrous) were added (methanol and methacrylic acid were 2: 1 (molar ratio)), and further. As a polymerization inhibitor, 0.388 g of hydroquinone (Tokyo Chemicals), 0.357 g of methoquinone (p-methoxyhydroquinone) (Tokyo Chemicals), and 0.365 g of phenothiazine (Tokyo Chemicals) were added and dissolved to prepare a raw material solution. did.
(Pretreatment of cation exchange resin)
The cation exchange resin was pretreated under the same conditions as in the above <Evaluation by batch reaction (dehydration system)> except that vacuum drying was not performed. That is, 10NV of 2N-HCl was passed through the cation exchange resin in advance to regenerate the H form. 20.0 ml of this cation exchange resin was weighed with a graduated cylinder and drained with a centrifuge. 20.0 ml of the cation exchange resin thus drained was placed in a 300 ml Erlenmeyer flask.
(MMA synthesis reaction and its analysis)
Under the same conditions as in the above <Evaluation by batch reaction (dehydration system)>, the MMA synthesis reaction and its analysis were performed.
[Example 1]
(Reactor)
As a reactor for the polymerization reaction, a glass polymerization can equipped with a stirring blade, a pressure gauge, a nitrogen pipe, and a thermometer was used.
(Water phase)
As an aqueous phase, 2% polyvinyl alcohol: hereinafter abbreviated as “PVA” as appropriate. ) 1075 ml of an aqueous solution containing 15 ml of an aqueous solution and 10 ml of a 0.1% methylene blue aqueous solution was prepared. In order to remove dissolved oxygen in the aqueous phase, nitrogen gas was circulated at 50 ml / min for 30 minutes while stirring the aqueous phase solution.
(Oil phase (monomer phase))
While using 249 g of styrene (St) and 12.44 g of a monomer solution of 63% divinylbenzene as a raw material monomer, 0.78 g of 75% BPO (purity 75% benzoyl peroxide manufactured by NOF Corporation) was used as a polymerization initiator, These were mixed to prepare an oil phase (monomer phase).
(Polymerization reaction)
The aqueous phase and the oil phase were placed in the reactor. The gas phase in the reactor was replaced with nitrogen by repeating the degassing operation of replacing with nitrogen gas three times. Subsequently, it stirred at 110 rpm for 30 minutes at 30 degreeC, and was set as the suspension. The temperature was raised to 80 ° C. over 2 hours and held at 80 ° C. for 8 hours. The obtained polymer was taken out from the reactor, washed with demineralized water, and dried at 50 ° C. for 8 hours using a vacuum dryer.
(Introduction of cation exchange groups)
100 g of the dried polymer is placed in a 2 L three-necked flask, and 300 g of ethylene dichloride (3.0 (g / polymer of 1 g)) is added as a solvent, and stirred at 50 ° C. for 1 hour to swell the resin I let you. In this, as shown in Table 1, 600 g of 98% sulfuric acid and 350 g of 25% olium were added to 100 g of the polymer. The temperature was raised from 30 ° C. to 80 ° C. over 3 hours, and kept at 80 ° C. for 8 hours. After completion of the reaction, the reaction solution was cooled to room temperature, and sulfuric acid was removed while adding demineralized water. Thereafter, the obtained polymer was taken out and washed with pure water to obtain a cation exchange resin.
[Example 2]
In (oil phase (monomer phase)), the monomer phase was adjusted by adding 258 g of styrene, 18.9 g of divinylbenzene, and 0.69 g of benzoyl peroxide, and (cation exchange) Group introduction) in the same manner as in Example 1 except that 98% sulfuric acid was added at a ratio of 4.5 (g / polymerized polymer 1 g) and 25% oleum at 2.5 (g / polymerized polymer 1 g). Cation exchange resin was produced under the conditions.
[Example 3]
In (oil phase (monomer phase)), the monomer phase was prepared with 245 g of styrene added, 16.4 g of divinylbenzene and 0.52 g of benzoyl peroxide added, and (cation exchange group) In addition, 98% sulfuric acid is added in a ratio of 4.5 (g / polymerized polymer 1 g) and 25% oleum in a ratio of 2.0 (g / polymerized polymer 1 g), and nitrobenzene is used as a solvent instead of ethylene dichloride. The cation exchange resin was produced under the same conditions as in Example 1 except that the reaction was performed at 110 ° C.
[Example 4]
In (oil phase (monomer phase)), the monomer phase was prepared by adding 220 g of styrene, 14.7 g of divinylbenzene, and 0.75 g of benzoyl peroxide, (polymerization reaction) In order to obtain a cation exchange resin having a small particle size, polymerization was carried out at a stirring speed of 450 rpm (this resulted in a polymer of about 140 μm), and (introduction of a cation exchange group) 98% A cation exchange resin was produced under the same conditions as in Example 1 except that sulfuric acid was added at a ratio of 3.0 (g / polymerized polymer 1 g) and 25% olium at a ratio of 1.5 (g / polymerized polymer 1 g). did.
[Example 5]
In (oil phase (monomer phase)), the monomer phase was prepared by adding 224 g of styrene, 15.2 g of divinylbenzene, and 0.72 g of benzoyl peroxide, (polymerization reaction) In order to obtain a cation exchange resin having a small particle size, polymerization was carried out at a stirring speed of 550 rpm (this resulted in a polymer of about 120 μm), and (introduction of a cation exchange group) 98% sulfuric acid was added. A cation exchange resin was produced under the same conditions as in Example 1 except that 3.0 (g / polymerized polymer 1 g) and 25% oleum were added at a ratio of 1.5 (g / polymerized polymer 1 g).
[Example 6]
The same conditions as in Example 3 except that in Example 3 (introduction of cation exchange groups), 98% sulfuric acid was added at a ratio of 6.0 (g / polymerized polymer 1 g) to effect sulfonation. A cation exchange resin was obtained.
(Addition of polymerization inhibitor)
The obtained cation exchange resin (H form) was drained with a centrifuge. 500 ml of this drained cation exchange resin was placed in a 2 L beaker, methanol was added thereto to make a 900 ml solution, and the mixture was stirred using a stirrer equipped with a stirring blade to make the cation exchange resin in a slurry state. .

In this, the solution which melt | dissolved 50 mg of phenothiazine as a polymerization inhibitor in methanol was added with the dropping funnel over 5 minutes, and it stirred for 30 minutes. Thereafter, demineralized water was added to replace the methanol solution with demineralized water.
[Example 7]
In Example 6, 4-amino TEMPO (4-Amino-2,2,6,6-tetramethylpiperidine 1-oxy) was used instead of phenothiazine.

Specifically, the obtained cation exchange resin (H form) was drained with a centrifuge. Put 500 ml of this drained cation exchange resin in a 2 L beaker, add demineralized water to this to make a 950 ml solution, and stir using a stirrer equipped with a stirring blade to bring the cation exchange resin into a slurry state. did.
In this, 50 ml of methanol solutions which contain 50 mg of amino TEMPO as a polymerization inhibitor were dripped over 5 minutes using the dropping funnel, and it stirred for 30 minutes after addition. Thereafter, demineralized water was added to replace the methanol solution with demineralized water.
[Example 8]
A cation exchange resin was produced under the same conditions as in Example 7 except that DPPH (1,1-diphenyl-2-picrylhydrazyl) was used instead of 4-amino TEMPO.
[Example 9]
In (oil phase (monomer phase)), the amount of styrene added is 152 g, the amount of divinylbenzene added is 16.0 g, the amount of polystyrene (weight average molecular weight 50000) added is 42.1 g, and the amount of benzoyl peroxide added is 0. .90 g of the monomer phase was adjusted (introduction of cation exchange group), 1.5% of 98% sulfuric acid (g / polymerized polymer 1 g), 25% olium 3.5 (g / polymerized polymer 1 g), A cation exchange resin was produced under the same conditions as in Example 1 except that nitrobenzene was used as a solvent at a ratio of 3.0 (g / polymerized polymer 1 g) and sulfonated at 105 ° C.
[Example 10]
(Introduction of a cation exchange group) Under the same conditions as in Example 9, except that 25% oleum was added at a ratio of 7.5 (g / polymerized polymer 1 g) and sulfonated at 105 ° C. for 5 hours. A cation exchange resin was produced.
[Example 11]
In (polymerization reaction), a cation exchange resin was produced under the same conditions as in Example 9 except that polymerization was carried out at a polymerization temperature of 80 ° C. to 120 ° C. for 8 hours using a pressure polymerization can made of SUS.
[Comparative Example 1]
In (oil phase (monomer phase)), the monomer phase was adjusted by adding 151 g of styrene, 5.0 g of divinylbenzene, and 0.36 g of benzoyl peroxide, and (cation exchange) In Example 1 except that 98% sulfuric acid was used in a ratio of 8.0 (g / polymerized polymer 1 g) and ethylene dichloride was used as a solvent in a ratio of 5.0 (g / polymerized polymer 1 g). A cation exchange resin was produced under the same conditions.
[Comparative Example 2]
In Example 3 (introduction of cation exchange group), except that 98% sulfuric acid was used at a ratio of 6.0 (g / polymerized polymer 1 g) instead of the mixed solution of 98% sulfuric acid and olium, A cation exchange resin was produced under the same conditions as in No. 3.
[Comparative Example 3]
In (oil phase (monomer phase)), the monomer phase was adjusted by adding 145 g of styrene, 9.8 g of divinylbenzene, 78.3 g of 2-ethylhexanol, and 0.92 g of benzoyl peroxide. And (introduction of cation exchange group) 98% sulfuric acid 3.0 (g / polymerized polymer 1 g), 25% oleum 1.0 (g / polymerized polymer 1 g), and ethylene dichloride as a solvent. A cation exchange resin was produced under the same conditions as in Example 1 except that it was used at a ratio of 4.0 (g / polymerized polymer 1 g).
[Comparative Example 4]
In (oil phase (monomer phase)), the monomer phase was adjusted by adding 152 g of styrene, 16.0 g of divinylbenzene, 93.6 g of n-heptane, and 0.90 g of benzoyl peroxide. And (introduction of a cation exchange group) 98% sulfuric acid 1.5 (g / polymerized polymer 1 g), 25% oleum 1.0 (g / polymerized polymer 1 g), and ethylene dichloride 4 as a solvent. A cation exchange resin was produced under the same conditions as in Example 1 except that it was used at a ratio of 0.0 (g / polymerized polymer 1 g).
[Comparative Example 5]
A cation exchange resin was produced under the same conditions as in Example 6 except that no polymerization inhibitor was added to the obtained cation exchange resin.
[Comparative Example 6]
In the oil phase (monomer phase), the monomer phase was prepared by adding 171.6 g of styrene, 58.4 g of divinylbenzene, and 0.52 g of benzoyl peroxide, and (cation exchange group) The same conditions as in Example 3 except that 98% sulfuric acid was used at a ratio of 2.0 (g / polymerized polymer 1 g) and 25% oleum at a ratio of 1.5 (g / polymerized polymer 1 g). A cation exchange resin was produced.
[Comparative Example 7]
As the cation exchange resin of Comparative Example 7 was used Amberlyst ^R 15 manufactured by Rohm and Haas Company.
[Comparative Example 8]
As the cation exchange resin of Comparative Example 8, it was used Lewatit ^R K2629 LANXESS Corporation.
[Comparative Example 9]
As the cation exchange resin of Comparative Example 9, using Lewatit ^R SP112 LANXESS. [Comparative Example 10]
In (oil phase (monomer phase)), the amount of styrene added was 157 g, the amount of divinylbenzene added was 22.8 g, the amount of polystyrene (weight average molecular weight 50000) added was 38.6 g, and the amount of benzoyl peroxide added was 0. .75 g of the monomer phase was adjusted (introduction of cation exchange groups), 98% sulfuric acid 1.5 (g / polymerized polymer 1 g), 25% olium 1.5 (g / polymerized polymer 1 g), A cation exchange resin was produced under the same conditions as in Example 9, except that nitrobenzene was used as a solvent at a ratio of 5.0 (g / polymerized polymer 1 g) and sulfonated at 105 ° C.
[Comparative Example 11]
In (oil phase (monomer phase)), the monomer phase was adjusted by adding 78.4 g of styrene, 51.6 g of divinylbenzene, 70.0 g of isododecane, and 1.45 g of benzoyl peroxide. In addition, the amount of 98% sulfuric acid added is 1.5 (g / polymerized polymer 1 g), 25% oleum is 1.5 (g / polymerized polymer 1 g), and nitrobenzene as a solvent. A cation exchange resin was produced under the same conditions as in Comparative Example 4 except that 4.0 was used at a ratio of 4.0 (g / polymerized polymer 1 g).
[Comparative Example 12]
As the cation exchange resin of Comparative Example 12 was used Duolite ^R C26H of Rohm and Haas Company.
[Evaluation results of cation exchange resins obtained in Examples and Comparative Examples]
The physical property values of the cation exchange resins obtained in Examples and Comparative Examples were measured by the measurement methods described above, and the results are shown in Table 1. The “orium concentration (% by weight)” in Table 1 is an actual olium concentration calculated in consideration of 2% water contained in 98% sulfuric acid.

実施例で得られた陽イオン交換樹脂は、（メタ）アクリル酸エステルの収率が高い傾向にあり、さらに、膨潤度も低いことから、（メタ）アクリル酸エステルの製造に際し、長期に渡って使用することができる。

The cation exchange resins obtained in the examples tend to have a high yield of (meth) acrylic acid esters and also have a low degree of swelling. Therefore, in the production of (meth) acrylic acid esters, over a long period of time. Can be used.

Moreover, the photograph before and behind the swelling of Example 10 and Comparative Example 3 is shown in FIGS. 1-4 so that the change before and behind swelling in the said <swelling evaluation method> may be understood. FIG. 1 shows the state before swelling of Example 10 and FIG. 2 shows the state after swelling. FIG. 3 shows the state before swelling of Comparative Example 3 and FIG. In FIG. 2, pMMA is observed around the cation exchange resin, but no change in the shape of the cation exchange resin itself is observed. On the other hand, in FIG. 4, it is observed that the cation exchange resin swells, explodes without being able to withstand the pressure, and has a popcorn shape.

  Since the strong acid cation exchange resin of the present invention can be suitably used for the production of (meth) acrylic acid esters, industrial applicability is extremely high.

The photograph before the swelling of the cation exchange resin manufactured in Example 10 is shown. The photograph after the swelling of the cation exchange resin manufactured in Example 10 is shown. The photograph before the swelling of the cation exchange resin manufactured by the comparative example 3 is shown. The photograph after the swelling of the cation exchange resin manufactured by the comparative example 3 is shown.

Claims (5)

The following (A), (B), and (C) are satisfied. A strongly acidic cation exchange resin for producing a (meth) acrylic acid ester.
(A) Surface area measured by nitrogen adsorption method is 2 m ² / g or less (B) Crosslinking degree is 2% by weight or more and 7.5% weight or less (C) Swelling degree is 2 or less (the swelling) The degree is a value represented by the following formula (I).
(Volume after adding methyl methacrylate monomer to the strong acid cation exchange resin and allowing it to swell by standing in a constant temperature bath at 70 ° C. for 72 hours) / (the strong acid cation regenerated to form H) Volume before exchange resin swelling))) Formula (I)) The strongly acidic cation exchange resin for production of (meth) acrylic acid ester according to claim 1, characterized in that the water content is 35% by weight or more. A strongly acidic cation exchange resin for the production of a (meth) acrylic acid ester according to claim 1 or 2, wherein the polymerization inhibitor is contained. A step of sulfonation using sulfuric acid containing 0.1% by weight or more of olium,
The manufacturing method of the strong acidic cation exchange resin for manufacture of the (meth) acrylic acid ester of any one of Claims 1-3. A method for producing a (meth) acrylic acid ester, wherein the strongly acidic cation exchange resin according to any one of claims 1 to 4 is used.

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