JPH10279528A - Itaconic acid ester and its polymer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject new compound excellent in homopolymerizability and copolymerizability, having hydroxyl and carboxyl groups in its molecule and useful for polymeric thickening agents, adhesives, additives for coating materials, bases for medical use, and so on. SOLUTION: This compound shown by the formula is obtained e.g. by addition reaction between itaconic acid anhydride and ethylene glycol at 50-90 deg.C for 5-10 h or dehydroesterification between itaconic acid and ethylene glycol in the presence or absence of an organic solvent using an acid catalyst such as p-toluenesulfonic acid at 60-150 deg.C for 5-10 h, followed by chromatographic separation and purification. Its homopolymer is obtained by radical polymerization of the itaconic acid ester of the formula singly and; its copolymer is obtained by radical polymerization of the itaconic acid ester with other copolymerizable monomer(s) such as styrene or methyl (meth)acrylate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to itaconic esters and polymers based on the itaconic esters. More specifically, it relates to an itaconic ester having a hydroxyl group and a carboxylic acid group in a molecule and a polymer obtained by polymerizing the itaconic ester.

[0002]

2. Description of the Related Art Conventionally, monomers having a carboxylic acid group or a hydroxyl group in a molecule have been widely used as a raw material of a water-soluble polymer or as a polymer modifier by copolymerization. For example, polyacrylic acid is used as a raw material for a superabsorbent resin or as a raw material for a thickener. Modification of polymerized acrylic paint has been put to practical use. Further, different from these fields, 2-hydroxyethyl methacrylate and methacrylic acid are used as raw materials for medical materials such as contact lenses. Monomers containing a carboxylic acid group or a hydroxyl group are used in the above-mentioned many fields because these groups and further a metal salt of a carboxylic acid are polymerized, whereby the polymer has high water solubility and high water content. This is because of providing adhesiveness to other materials and heat resistance. However, monomers such as acrylic acid, methacrylic acid and 2-hydroxyethyl methacrylate are excellent in that high polymerizability and water-soluble and other characteristic polymers can be obtained,
There was a problem with polymerization control. That is, since these monomers have remarkably high homopolymerizability, intense heat of polymerization and gelation are likely to occur. In addition, in copolymerization with other monomers, ethylene, propylene, vinyl acetate, poor copolymerizability with non-conjugated monomers such as vinyl chloride, acrylic acid,
Since homopolymerization of methacrylic acid or 2-hydroxyethyl methacrylate precedes, there is a problem that it is difficult to randomly copolymerize.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide an itaconic ester having excellent homo- and copolymerizability and having a hydroxyl group and a carboxylic acid group in the molecule. It is a further object of the present invention to provide a polymer based on the itaconic ester.

[0004]

Means for Solving the Problems The present inventors have conducted intensive studies in view of the above problems, and as a result, have found a novel itaconic ester, and have found that a novel polymer can be obtained from the itaconic ester. To complete the present invention. That is, the present invention is as follows (1) to (3). (1) The following formula [I]

Embedded image An itaconic ester represented by the formula: (2) A polymer obtained by radical homopolymerization or copolymerization of the itaconic acid ester represented by the above formula [I]. (3) The polymer has the following formula [II]

Embedded image (Where M is a constitutional unit based on styrene or methyl (meth) acrylate, m is a formula [I], n is the number of repeating polymerizations of the constitutional unit based on styrene or methyl (meth) acrylate, and m = 2 6,000, n = 0
10,000. [] May be either random or block-like addition. A) a polymer having a number average molecular weight of 2,000 to 1,000,000.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The itaconic acid ester of the present invention comprises
The following formula [I]

Embedded image And an itaconic ester having a hydroxyl group and a carboxylic acid group. By homopolymerizing or copolymerizing the itaconic acid ester with another monomer by a radical polymerization method, a polymer containing an equal amount of a hydroxyl group and a carboxylic acid group in a polymer chain can be obtained.

The synthesis of the itaconic acid ester of the present invention can use a known esterification reaction. For example, there is a method in which itaconic anhydride and ethylene glycol are subjected to an addition reaction at a reaction temperature of 50 to 90 ° C. for 5 to 10 hours. Alternatively, itaconic acid and ethylene glycol may be reacted at a reaction temperature of 60 to 150 ° C. with an acid catalyst such as paratoluenesulfonic acid at a reaction temperature of 60 to 150 ° C. in the presence or absence of an organic solvent.
It can also be obtained by synthesis by a method of dehydrating and esterifying for 0 hours, followed by purification and separation by chromatography.

The itaconic acid ester represented by the formula [I] of the present invention can be homopolymerized by radical polymerization alone. In addition, the unsaturated group of the itaconic acid ester of the present invention has good copolymerizability with many vinyl monomers regardless of non-conjugated type or conjugated type, so that it is obtained as a copolymer by radical copolymerization with other vinyl monomers. You can also get. In this case, other copolymerizable monomers include styrene monomers such as styrene and α-methylstyrene; (meth) acrylic acid; methyl (meth) acrylate, ethyl (meth) acrylate, isopropyl (meth) acrylate, and n-methyl methacrylate. Butyl (meth) acrylate,
Alkyl (meth) acrylates such as 2-ethylhexyl (meth) acrylate; 2-hydroxyethyl (meth)
Acrylate, polyethylene glycol (meth) acrylate, glycidyl (meth) acrylate, (meth) acrylonitrile, (meth) acrylamide, N, N-dimethyl (meth) acrylamide, vinyl acetate, dimethyl fumarate, diethyl fumarate, di-n-butyl Monofunctional monomers such as fumarate, di-n-butylmalate, diethylitaconate, N-vinylpyrrolidone, cyano (meth) acrylate, vinyl chloride, vinylidene chloride, ethylene; divinylstyrene, ethylene glycol di (meth) acrylate, neopentyl di (meth) ) Acrylate, polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, pentaerythritol tri (meth)
Acrylate, glycerol di (meth) acrylate,
Examples thereof include polyfunctional monomers such as 2,2-bis [(meth) acryloyloxyethoxyphenyl] propane and diallyl phthalate. More preferred are styrene and methyl (meth) acrylate. One or more of these vinyl monomers can be used as a mixture.
When a polyfunctional monomer is used, a crosslinkable polymer is obtained.

The itaconic acid ester of the present invention can obtain a water-soluble polymer of the present invention having a hydroxyl group and a carboxylic acid group in a side chain by homopolymerization. Further, by copolymerizing, a hydroxyl group and a carboxylic acid group can be introduced into a polymer based on a copolymerizable monomer. Accordingly, properties such as hydrophilicity, hydrophobicity, mechanical strength, and adhesiveness of the polymer can be controlled. The proportion of the polymer portion based on the other copolymerizable monomer is 0.5% in the copolymer.
~ 95% by weight. If the amount is less than 0.5% by weight, the effect of the copolymerizable monomer cannot be obtained. If the amount is more than 95% by weight, the effect of the itaconic acid ester decreases, which is not preferable.

The polymer of the present invention has the following formula [II]

Embedded image (Where M is a structural unit based on styrene or methyl (meth) acrylate, m is the number of repeating structural units based on styrene or methyl (meth) acrylate, and m is 2 to 6 000, n = 0-1
It is 0000. [] May be either random or block-like addition. ) Is a polymer having a number average molecular weight of 2,000 to 1,000,000. In the general formula [II], M is a structural unit based on styrene or methyl (meth) acrylate, m is a formula [I], n is the number of repeating structural units based on styrene or methyl (meth) acrylate, and m = 2-6,0
00, n = 0 to 10,000. [] May be either random or block-like addition.

The polymer of the present invention can be obtained by radical polymerization of the itaconic ester of the formula [I] alone or by radical copolymerization with another copolymerizable monomer. The polymerization can be performed by a known polymerization method such as bulk polymerization, solution polymerization, suspension polymerization, non-aqueous suspension polymerization, and emulsion polymerization. For example, a radical polymerization initiator is added to the itaconic acid ester of the formula [I] alone or to a mixture of the formula [I] and another copolymerizable monomer,
It can be obtained by performing polymerization at a polymerization temperature of 0 to 90 ° C. for about 3 to 48 hours.

Examples of the radical polymerization initiator used in the polymerization include oil-soluble ones such as azobisisobutylnitrile, azobisvaleronitrile, lauroyl peroxide and benzoyl peroxide, and ammonium persulfate, potassium persulfate and hydrogen peroxide. Water-soluble ones are used, and used in an amount of 0.01 to 10% by weight of the whole polymerization raw materials.

Although the molecular weight of the polymer of the present invention varies depending on the polymerization conditions, the number average molecular weight is in the range of 2,000 to 1,000,000, and the homopolymer has a molecular weight of 2,000.
000 to 100,000, 2 for copolymer
Those having a high molecular weight range of from 000 to 1,000,000 are preferred.

The polymerization can be carried out without solvent, or a solvent can be used. As the solvent used,
Examples include aromatic compounds such as benzene and toluene, alcohols such as methanol, ethanol and isopropanol, ketones such as acetone and methyl ethyl ketone, tetrahydrofuran, 1,4-dioxane, and ethyl acetate.
These solvents may be used alone or in a mixture of two or more. The amount of the solvent used is desirably 0.1 to 10 times the total weight of the monomers.

The polymer can be purified by dissolving it in a good solvent such as benzene or tetrahydrofuran and precipitating it in a poor solvent such as diethyl ether or n-hexane, if necessary.

[0015]

The itaconic acid ester of the present invention is a novel itaconic acid ester having a hydroxyl group and a carboxylic acid group represented by the above formula [I] in the side chain. The itaconic ester can be synthesized into a homopolymer or a copolymer with another monomer by a radical polymerization method. Since the hydroxyl group and the carboxylic acid group are simultaneously introduced into the polymer of the present invention, when the number of structural units based on the itaconic ester is large, the polymer exhibits physical properties as a water-soluble polymer. In addition, since the copolymer has a structural unit based on itaconic acid ester having a hydroxyl group and a carboxylic acid group of the formula [I], the hydrophilicity of the polymer can be modified. Therefore, utilization of these properties in the fields of polymer thickeners, adhesives, paint additives, medical base materials, and the like can be mentioned.

[0016]

The present invention will be described in more detail with reference to the following examples. Example 1 112 g (1 mol) of itaconic anhydride and 62 g (1 mol) of ethylene glycol were added to a 200 cc flask equipped with a stirrer, a nitrogen inlet tube, and a thermometer. 80 on oil bath
℃ and stir for 8 hours while blowing in nitrogen.
The anhydrous ring was subjected to a ring opening reaction. The obtained compound was subjected to IR analysis and 1H-NMR analysis. The results of the IR analysis are as follows. 3350 cm ^-1 ; absorption of hydroxyl group (-OH) 3500 to 2500 cm ^-1 ; wide absorption by carboxylic acid (-OH) 1720 cm ^-1 ; carboxylic acid or ester group-(C =
O)-Strong absorption confirmed; 1820 cm ^-1 ; Ring anhydride of raw material itaconic anhydride-(C
The absorption of O—O—CO) — disappears 1750 cm ⁻¹ ; the ring anhydride of raw material itaconic anhydride — (C
The strong absorption of (O-O-CO)-disappeared. The result of ¹ H-NMR is as follows. (Δ (ppm), TMS = trimethylsilane standard / CD
Cl ₃₎ 3.2 ppm; strong absorption 3.4~3.7ppm of _{-CH 2 C = O; -CH 2} CH 2 - 4.1~4.3ppm; -CH 2 CH 2 - 5.7~6. Since no absorption was observed at 25 ppm; = CH _{2 and} others, it was confirmed that the obtained compound was a glycol monoester of itaconic acid of the formula [1] of the present invention and was synthesized almost quantitatively.

Example 2 Homopolymer of Formula [1] {= Poly (ITE)] 5 g of ethylene glycol monoester itaconate obtained in Example 1 and 0.05 g of azobisisobutylnitrile as a radical polymerization initiator were used. After charging into a glass tube and repeating the degassing-nitrogen substitution three times, the glass tube was sealed. Polymerization was carried out in a constant temperature water bath at 70 ° C. for 8 hours. After the polymerization, 20 cc of methanol was added to the polymerization solution and dissolved,
Then, the mixture was put into cc to precipitate a polymer. The polymer was filtered off. Further, this was dissolved in methanol, and reprecipitation purification was repeated with diethyl ether, followed by vacuum drying at 60 ° C. The yield of the polymer was 55% by weight. The obtained polymer was subjected to molecular weight measurement by GPC, IR analysis, ¹ H-N
MR analysis was performed. The molecular weight of the polymer was Mn = 22000 in terms of polyethylene glycol. The IR analysis of the obtained polymer is as follows. (NaCl) 2300-3700 cm ^-1 ; broad absorption of -COOH 3300 cm ^-1 ; strong absorption of -OH group The result of ¹ H-NMR analysis is as follows. (Δ (ppm), TMS = trimethylsilane standard / D _{2
O) 1.43ppm; -CH 2 - 3.56ppm} ; -CH 2 OH 4.0 ppm; -OCH 2 - <confirm>5.7~6.25ppm; absorption of -C = CH ₂ in the raw material disappeared It was confirmed that the obtained polymer was a homopolymer of itaconic acid ethylene glycol monoester.

Example 3 Copolymer of Formula [I] and STＳＴ =
Poly (ITE-co-ST)} Polymerization was carried out in exactly the same manner as in Example 2, except that a monomer mixture of 1 g of ethylene glycol monoester itaconate obtained in Example 1 and 4 g of styrene was used. After the polymerization, the copolymer was dissolved in 20 cc of benzene and poured into 100 cc of diethyl ether to precipitate the copolymer. The polymer was purified by reprecipitation with a benzene-methanol system, and then dried at 60 ° C. in vacuo. The copolymer yield is 96
% By weight. The obtained copolymer was subjected to measurement of molecular weight by tetrahydrofuran-based GPC, ¹ H-NMR analysis,
IR analysis and elemental analysis were performed. The molecular weight of the obtained copolymer was Mn = 85,000 in terms of polystyrene. The results of ¹ H-NMR analysis of the obtained copolymer are as follows. (Δ (ppm), TMS = trimethylsilane standard / CD
_{Cl 3) 1.43ppm; -CH 2 -} 3.56ppm; -CH 2 OH 4.0 ppm; -OCH 2 - 6.8~7.3ppm; the results of H IR analysis of the benzene nucleus as follows. (NaCl, Nujol) 1490cm ^-1; benzene ring 2400~3400cm ^-1; the presence of broad absorption of -COOH [I] and the copolymer component of the ST was confirmed. The copolymer was determined for its copolymer composition from the contents of carbon and hydrogen by elemental analysis. The content of ethylene glycol monoester itaconate was 22% by weight. Elemental analysis C%: H% 79.6: 6.5 From the above results, the structure of the copolymer was identified as a compound represented by the following formula.

Embedded image m = 107 n = 638 Number average molecular weight 85,000

Example 4 Copolymer of Formula [I] and MMA {= poly (ITE-co-MMA)} A monomer mixture of 1 g of ethylene glycol monoester itaconate obtained in Example 1 and 4 g of methyl methacrylate was used. Polymerization was carried out in exactly the same manner as in Example 2, except for using it. After the polymerization, purification was performed in the same manner as in Example 3 to obtain a copolymer. The yield of the copolymer was 87% by weight. The obtained copolymer was subjected to measurement of molecular weight, IR analysis, and ¹ H-NMR analysis by tetrahydrofuran-based GPC.
The molecular weight of the copolymer was Mn = 5 in terms of polystyrene.
It was 3,000. The results of ¹ H-NMR analysis are as follows. (Δ (ppm), TMS / CDCl ₃ ) 0.7 to 1.25 ppm; α-CH ₃ 3.6 ppm; -OCH ₃ 4.0 ppm; -OCH _2- The results of the IR analysis are as follows. 2500 to 3750 cm ^-1 ; broad absorption of -COOH From the area ratio of -OCH _2- (ITE = itaconic acid ester) to -OCH ₃ (MMA) in ¹ H-NMR, the content of ethylene glycol monoester itaconate is 18% by weight. Was asked. From the above results, the structure of the copolymer was identified as a compound represented by the following formula.

Embedded image m = 55 n = 434 Number average molecular weight 53,000.

Claims (3)

[Claims] 1. A compound represented by the following formula [I]: An itaconic ester represented by the formula: 2. A polymer obtained by radical homopolymerization or copolymerization of the itaconic ester represented by the formula [I] according to claim 1. 3. The polymer according to claim 2, wherein the polymer is represented by the following formula [II]: (Where M is a structural unit based on styrene or methyl (meth) acrylate, m is the number of repeating structural units based on styrene or methyl (meth) acrylate, and m is 2 to 6 000, n = 0-1
It is 0000. [] May be either random or block-like addition. A) a polymer having a number average molecular weight of 2,000 to 1,000,000.