Process for preparing water-soluble styrenelacrylic resins by continuous bulk polymerization

Abstract

The invention relates to a bulk polymerization process for preparing water-soluble styrene / acrylic resins, in which styrene and acryl monomers are polymerized in a solvent mixture of dipropylene glycol methyl ether and water in a temperature-controllable reactor equipped externally with an oil jacket containing a cooling coil therein and the resulting polymers are deprived of volatile contents in a falling-strand type devolatilizer. The water-soluble styrene / acrylic resins take industrial advantages over conventional resins because the resins, if polymerized at lower temperatures, show lower molecular weights, narrower molecular weight distributions, higher acid values and lower volatile content.

Description

technical field

[0001] The invention relates to a method for preparing water-soluble styrene / acrylic resin by continuous bulk polymerization. More specifically, the present invention relates to a process for preparing low molecular weight polymers of narrow molecular weight distribution, high acid number and low volatile content by continuous bulk polymerization. technical background

[0002] Most inks, paints and coatings in use today use organic solvents. This is because when inks, paints, and coatings are used, the organic materials of organic solvents evaporate, and they are now found to cause serious air pollution. In addition, organic solvents have a high potential to cause fires due to their flammability.

[0003] As an alternative to avoid these problems, high solids liquid coatings based on water-soluble styrene / acrylic resins have been proposed. In fact, these high-solids liquid coatings are good in terms of not causing atmospheric pollution. Contrary to organi...

Examples

Embodiment I-V

[0034] Styrene monomers (styrene and α-methylstyrene) and acrylic acid monomers (acrylic acid) were charged to a continuously stirred, temperature-controlled reactor externally equipped with an oil jacket containing a cooling coil, as listed in Table 1 below. Shown to prepare water-soluble styrene / acrylic resin.

[0035] Polymerization was initiated in the presence of t-butylperoxybenzoate. The polymerization initiator is used in an amount of 3.5 parts by weight, based on the total weight of the monomer mixture. For the polymerization, 15 parts by weight of a mixed solvent of dipropylene glycol methyl ether and water having a water content of 35% by weight were used, based on 100 parts by weight of the monomer mixture. Polymerization was carried out under different temperature conditions ranging from 150 to 220°C. The polymerized resin passes through the falling strand type exhaust section, from which the volatile components are removed. At the same time, the exhaust sectio...

Embodiment VI-IX

[0043] In order to investigate the effect of the operating conditions of the vent section on the physical properties of the resin, the polymerization was carried out in the same manner as in Example IV, but under the temperature and pressure conditions of the vent section shown in Table 3 below. The results are shown in Table 3.

[0044] Example number

Embodiment X-XIII

[0050] A water-soluble styrene / acrylic resin was prepared in a manner similar to Example IV, except that the amount and water content of the mixed solvent of dipropylene glycol methyl ether and water were changed, as shown in Table 5 below.

technical field

[0001] The invention relates to a method for preparing water-soluble styrene / acrylic resin by continuous bulk polymerization. More specifically, the present invention relates to a process for preparing low molecular weight polymers of narrow molecular weight distribution, high acid number and low volatile content by continuous bulk polymerization. technical background

[0002] Most inks, paints and coatings in use today use organic solvents. This is because when inks, paints, and coatings are used, the organic materials of organic solvents evaporate, and they are now found to cause serious air pollution. In addition, organic solvents have a high potential to cause fires due to their flammability.

[0003] As an alternative to avoid these problems, high solids liquid coatings based on water-soluble styrene / acrylic resins have been proposed. In fact, these high-solids liquid coatings are good in terms of not causing atmospheric pollution. Contrary to organi...

Examples

Embodiment I-V

[0034] Styrene monomers (styrene and α-methylstyrene) and acrylic acid monomers (acrylic acid) were charged to a continuously stirred, temperature-controlled reactor externally equipped with an oil jacket containing a cooling coil, as listed in Table 1 below. Shown to prepare water-soluble styrene / acrylic resin.

[0035] Polymerization was initiated in the presence of t-butylperoxybenzoate. The polymerization initiator is used in an amount of 3.5 parts by weight, based on the total weight of the monomer mixture. For the polymerization, 15 parts by weight of a mixed solvent of dipropylene glycol methyl ether and water having a water content of 35% by weight were used, based on 100 parts by weight of the monomer mixture. Polymerization was carried out under different temperature conditions ranging from 150 to 220°C. The polymerized resin passes through the falling strand type exhaust section, from which the volatile components are removed. At the same time, the exhaust sectio...

Embodiment VI-IX

[0043] In order to investigate the effect of the operating conditions of the vent section on the physical properties of the resin, the polymerization was carried out in the same manner as in Example IV, but under the temperature and pressure conditions of the vent section shown in Table 3 below. The results are shown in Table 3.

[0044] Example number

Embodiment X-XIII

[0050] A water-soluble styrene / acrylic resin was prepared in a manner similar to Example IV, except that the amount and water content of the mixed solvent of dipropylene glycol methyl ether and water were changed, as shown in Table 5 below.

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