KR100604769B1 - Polymerization method for acrylic polymer - Google Patents

Abstract

The present invention relates to a method for producing an acrylic polymer, and to provide a production method capable of producing a pure polymer or copolymer without addition reaction by carrying out the reaction in a short time without a catalyst by performing the reaction in a high temperature and high pressure reactor. Specifically, (meth) acrylates substituted or unsubstituted with an alkyl group having 1 to 5 carbon atoms, an alkyl group having 1 to 5 carbon atoms substituted or unsubstituted with an alkyl group having 1 to 5 carbon atoms and an alkyl group having 1 to 5 carbon atoms in the high temperature and high pressure reactor 0.5 to 1.5 hours at 200-240 ° C. in the presence of mixed monomers, solvents and radical initiators with at least one monomer selected from substituted or unsubstituted acrylic acid monomers or with at least one monomer selected from vinylaromatic monomers copolymerizable therewith. Warming; Cooling step; And adding an aqueous alkali solution to form an initiator precipitate, followed by filtration to obtain an acrylic polymer or copolymer. The acrylic polymer or copolymer thus obtained is a high molecular compound used to improve optical properties in the field of LCD optical films. useful.

Polymethyl methacrylate, high temperature and high pressure reactor, copolymer, monomer, molecular weight

Description

Manufacturing method of acrylic polymer {Polymerization method for acrylic polymer}

1 is a graph of an analysis result by thermogravimetric analysis of poly (methyl methacrylate) obtained according to Example 1,

2 is a scanning electron micrograph of poly (methyl methacrylate) obtained according to Example 1,

3 is a graph of an analysis result by thermogravimetric analysis of poly (methyl methacrylate-co-butyl methacrylate) obtained according to Example 2,

4 is a scanning electron micrograph of the poly (methyl methacrylate-co-butyl methacrylate) obtained according to Example 2,

5 is a graph of an analysis result by thermogravimetric analysis on poly (methyl methacrylate-co-methacrylic acid) obtained according to Example 3,

6 is a scanning electron micrograph of poly (methyl methacrylate-co-methacrylic acid) obtained according to Example 3,

7 is a graph of an analysis result by thermogravimetric analysis on poly (styrene-co-methyl acrylate) obtained according to Example 4,

8 is a scanning electron micrograph of the poly (styrene-co-methyl acrylate) obtained according to Example 4. FIG.

The present invention relates to a method for producing an acrylic polymer, and more particularly, to a method for producing an acrylic polymer with high purity by controlling another addition reaction without using a catalyst by using a high temperature and high pressure reactor.

Acrylic polymers, such as polymethyl methacrylate, are emerging as polymer compounds for enhancing optical properties as well as inherent roles of impact modifiers. In other words, it is coated on a base film such as polyester to increase optical properties, and its use is attracting attention in the field of LCD optical films.

In producing such an acrylic polymer or copolymer, polymerization is carried out using a predetermined monomer and an initiator in the presence of a solvent such as toluene or the like. Usually, the polymerization is performed by heating at least 5 to 8 hours in a temperature range of 50 to 80 ° C.

However, according to the conventional method for producing an acrylic polymer or copolymer, it is difficult to obtain a desired polymer or copolymer purely because the addition reaction tends to proceed, and the reaction time is long and inefficient. In other words, according to the conventional manufacturing method, it was difficult to prepare a compound having a uniform molecular weight, and in order to control this, it was intended to increase the reactivity by activating the monomer using a catalyst. As such, when the molecular weight is nonuniform, there is a problem in that a byproduct such as a compound connected to various lengths is prepared.

Therefore, the present invention is to solve the problem of the acrylic polymer production method performed in the presence of a conventional catalyst, by performing the reaction in a high temperature and high pressure reactor to perform the reaction in a short time without a catalyst it is possible to produce a pure polymer or copolymer without addition reaction It is an object to provide a method for producing an acrylic polymer.

Method for producing an acrylic polymer of the present invention for achieving the above object is a (meth) acrylate, which is unsubstituted or substituted with an alkyl group of 1 to 5 carbon atoms in the high temperature and high pressure reactor, or is not substituted or substituted with an alkyl group of 1 to 5 carbon atoms Of a monomer, a solvent and a radical initiator with at least one monomer selected from an acrylic acid alkyl ester and an acrylic acid monomer substituted or unsubstituted with an alkyl group having 1 to 5 carbon atoms, or at least one monomer selected from vinyl aromatic monomers copolymerizable therewith. Warming in the presence at 200 to 240 ° C. for 0.5 to 1.5 hours; Cooling step; And dropwise adding an aqueous alkali solution to generate an initiator precipitate, followed by filtration to obtain an acrylic polymer or copolymer.

The present invention will be described in more detail as follows.

The present invention relates to a method for producing an acrylic polymer or copolymer having a high molecular weight and a uniform molecular weight, characterized in that the reaction of the present invention is carried out in a high temperature and high pressure reactor.

Monomers that can be used to prepare acrylic polymers or copolymers of the present invention are those used to prepare conventional acrylic polymers or copolymers, and (meth) acrylates which are unsubstituted or substituted with alkyl groups having 1 to 5 carbon atoms, and have 1 to C carbon atoms. Mixed monomers with at least one monomer selected from acrylic acid alkyl esters substituted or unsubstituted with an alkyl group of 5 and an acrylic acid monomer substituted or unsubstituted with an alkyl group, or at least one monomer selected from vinyl aromatic monomers copolymerizable therewith. have.

More specifically, it may be at least one monomer selected from methyl methacrylate, 2-methyl acrylic acid butyl ester, acrylic acid methyl ester, 2-methyl acrylic acid, or a mixed monomer with vinylbenzene copolymerizable therewith.

This monomer is added to a high temperature and high pressure reactor, and then a solvent is added and stirred.

In this case, as the solvent, trichlorobenzene is used. In addition, 1,2-dichlorobenzene may be used. The amount of the solvent is preferably 200 to 500 parts by weight based on the weight of the monomer.

Then, the radical initiator is added thereto, followed by warming at 200 to 240 ° C. for 0.5 to 1.5 hours. The radical initiator herein is not limited as long as it is usually used in radical polymerization, and in the present invention, cumene hydroperoxide, t -butyl hydroperoxide, dicumyl peroxide, or di-t-butyl peroxide may be used.

The radical initiator is preferably used in an amount of 0.1 to 1 parts by weight based on the monomer weight.

In the high temperature and high pressure reactor, the radical polymerization reaction is performed at 200 to 240 ° C., if the polymerization temperature is lower than 200 ° C., unreacted and side reaction products are formed. Can be.

In the above temperature range, the polymerization reaction is preferably performed for 0.5 to 1.5 hours. If the reaction time is shorter than 0.5 hours, unreacted substances and side reactions are generated, and when the reaction time is performed for longer than 1.5 hours, the starting material (monomer) is decomposed. There may be a problem.

As described above, when the reaction is performed in a high temperature and high pressure reactor, a compound having a uniform molecular weight may be prepared, and thus, by-products such as compounds connected to various lengths may be reduced.

When the polymerization reaction is completed as described above, it is cooled, and an aqueous alkali solution is added dropwise to the reactant to generate an initiator precipitate.

According to the present invention, an acrylic polymer or copolymer having a molecular weight distribution of 15,000 to 75,000 can be obtained with a purity of 90 to 98%.

Hereinafter, the present invention will be described in detail with reference to Examples, but the present invention is not limited by the Examples.

Example 1

30 g of methyl methacrylate (1) was added to the high temperature and high pressure reactor, and 100 ml of 1,2,4-trichlorobenzene was added and stirred. 0.1 g of cumene hydroperoxide, a radical initiator, was added thereto, followed by heating at 220 ° C. for 1 hour, followed by cooling. 0.1 N NaOH aqueous solution was added dropwise to the reaction mixture, and the precipitate formed after the reaction was filtered to obtain Compound 2 as a product.

Confirmation of the product was confirmed by thermogravimetric analysis (TGA), scanning electron microscopy (SEM), the results are as shown in Figs.

From the results of the TGA shown in FIG. 1, it can be seen that one phase change is shown at 272.1 to 422.6 ° C., and it can be seen that the compound has spherical particles having a size of 180 to 200 μm from the SEM result shown in FIG. 2. In general, when an acrylic polymer is used as a polymer for imparting optical properties, it is known that when the particle shape is spherical, the coating property is excellent in coating on the lower surface as well as the optical property is excellent.

Example 2

30 g of methyl methacrylate (1) was added to the high temperature and high pressure reactor, and then 100 ml of 1,2,4-trichlorobenzene was added and stirred. After adding 30 g of 2-methyl acrylic acid butyl ester (3) to the reaction, 0.1 g of cumene hydroperoxide, a radical initiator, was added, followed by cooling at 220 ° C. for 1 hour and then cooling. 0.1 N NaOH aqueous solution was added dropwise to the reaction mixture, and the precipitate formed after the reaction was filtered to obtain Compound 4 as a product.

Confirmation of the product was confirmed by thermogravimetric analysis (TGA), scanning electron microscopy (SEM), the results are shown in Figures 3 to 4, respectively.

It can be seen from the results of the TGA shown in FIG. 3 that one phase change appears at 226.6 to 433.4 ° C., and it can be seen that the compound has spherical particles having a size of 150 to 200 μm from the SEM result shown in FIG. 4.

Example 3

30 g of methyl methacrylate (1) was added to the high temperature and high pressure reactor, and then 100 ml of 1,2,4-trichlorobenzene was added and stirred. 30 g of 2-methyl acrylic acid (5) was added to the reaction product, followed by adding 0.1 g of cumene hydroperoxide, a radical initiator, and then warming at 220 ° C. for 1 hour, followed by cooling. 0.1 N NaOH aqueous solution was added dropwise to the reaction mixture, and the precipitate formed after the reaction was filtered to obtain 6 as a product.

Confirmation of the product was confirmed by thermogravimetric analysis (TGA) and scanning electron microscopy (SEM), the results are shown in Figures 5 to 6, respectively.

From the results of the TGA shown in FIG. 5, it can be seen that one phase change is shown at 286.5 to 422.6 ° C., and it can be seen that the compound has spherical particles having a size of 170 to 200 μm from the SEM result of FIG. 6.

Example 4

30 g of acrylic acid methyl ester (8) was added to the high temperature and high pressure reactor, and 100 ml of 1,2,4-trichlorobenzene was added and stirred. 30 g of vinyl benzene (7) was added to the reaction product, and 0.1 g of cumene hydroperoxide, a radical initiator, was added thereto, followed by heating at 220 ° C. for 1 hour, followed by cooling. 0.1 N NaOH aqueous solution was added dropwise to the reaction mixture, and the precipitate formed after the reaction was filtered to obtain Compound 9, a product.

Confirmation of the product was confirmed by thermogravimetric analysis (TGA) and scanning electron microscopy (SEM), the results are shown in Figures 7 to 8, respectively.

From the results of the TGA shown in FIG. 7, it can be seen that one phase change is shown at 272.5 to 436.2 ° C., and it can be seen that the compound has spherical particles having a size of 15 to 25 μm from the SEM result shown in FIG. 8.

As described above in detail, when the acrylic polymer or copolymer is prepared by radical polymerization for a short time while being heated in a high temperature and high pressure reactor according to the present invention, the acrylic polymer or copolymer may be manufactured with high purity while having a uniform molecular weight. These acrylic polymers or copolymers have excellent processability and mechanical properties, weather resistance to light, light transmittance and solvent resistance to chemicals, and are additionally coated to improve optical properties on films such as LCD optical films and white films. It is useful as a high molecular compound.

Claims (6)

(Meth) acrylate unsubstituted or substituted with an alkyl group having 1 to 5 carbon atoms, an acrylic acid alkyl ester substituted with or without an alkyl group having 1 to 5 carbon atoms and an alkyl group having 1 to 5 carbon atoms unsubstituted in a high temperature high pressure reactor Warming at 200 to 240 ° C. for 0.5 to 1.5 hours in the presence of a mixed monomer, a solvent and a radical initiator with at least one monomer selected from acrylic acid monomers or copolymerizable with at least one monomer selected from vinylaromatic monomers copolymerizable therewith; Cooling step; And A method of producing an acrylic polymer comprising dropping an aqueous alkali solution to form an initiator precipitate and then filtering to obtain an acrylic polymer or copolymer. The method of claim 1, wherein the monomer is at least one monomer selected from methyl methacrylate, 2-methyl acrylic acid butyl ester, acrylic acid methyl ester, 2-methyl acrylic acid, or a mixed monomer with vinylbenzene copolymerizable therewith. A method for producing an acrylic polymer. The method of claim 1, wherein the radical initiator comprises at least one selected from cumene hydroperoxide, t -butyl hydroperoxide, dicumyl peroxide, and di-t-butyl peroxide. . The method of claim 1 or 3, wherein the radical initiator is used in an amount of 0.1 to 1 parts by weight based on the weight of the monomer. The method of claim 1, wherein the solvent is 1,2,4-trichlorobenzene or 1,2-dichlorobenzene. The method for producing an acrylic polymer according to claim 1 or 5, wherein the solvent is used in an amount of 200 to 500 parts by weight based on the weight of the monomer.

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