KR20070071994A - Process for producing polyalkyl(meth)acrylate with a high glass transition temperature and the produced polymer - Google Patents

Abstract

Provided are a method for preparing a poly(alkyl(meth)acrylate) having high glass transition temperature and improved processability, and a poly(alkyl(meth)acrylate) prepared by the method. The method comprises the step of radical-polymerizing an alkyl(meth)acrylate in the presence of a Lewis catalyst and an initiator to prepare a poly(alkyl(meth)acrylate). Preferably the alkyl(meth)acrylate is represented by the formula(1), wherein R1, R2 and R3 are independently H, a C1-C30 hydrocarbon group or a monovalent atom group containing a hetero atom; and R4 is H or a methyl group. Preferably the cation of the Lewis catalyst is at least one cation selected from the group consisting of scandium, titanium, vanadium, chromium, manganese, iron, cobalt, copper, zinc, boron, aluminum, yttrium, zirconium, niobium, molybdenum, cadmium, rhenium and tin.

Description

PROCESS FOR PRODUCING POLYALKYL (METH) ACRYLATE WITH A HIGH GLASS TRANSITION TEMPERATURE AND THE PRODUCED POLYMER}

1 is a dynamic scanning calorimeter (DSC) measurement result of PMMA (polymethyl (meth) acrylate) prepared according to Example 1. FIG.

2 is a DSC measurement result of PMMA of Example 2 and Comparative Examples 1 to 2. FIG.

3 shows the results of measuring the dynamic viscosity of Example 2 and Comparative Example 2. FIG.

The present invention relates to a method for producing a high heat resistant acrylate polymer, and more particularly, to a method for producing a high heat resistant acrylate polymer by radical polymerization in the presence of a Lewis acid catalyst.

Heterogeneous polymerization, such as conventional emulsion polymerization or suspension polymerization, is one of the important methods of polymer synthesis and has many advantages over homogeneous polymerization. However, in the above methods, since all radicals are not started at the same time and the termination reaction is dominant, it is difficult to control the structure or molecular weight of the final polymer and it is difficult to obtain a polymer having a uniform size. Therefore, a living radical method such as nitroxide (nitroxide) method, ATRP (atom transfer radical polymerization) method using Cu, Co, etc. to secure such a disadvantage has attracted industrial attention. However, the method using nitroxide has a disadvantage that the reaction time takes too long, and the ATRP method has a disadvantage in that it is difficult to separate the transition metal during the polymer purification process.

On the other hand, acrylate-based polymers are used in various applications, such as cosmetic pigments, paint pigments, matting agents, industrial absorbents and oil absorbents, and their use is expanding, such as being used as electronic materials by metal coating. In particular, due to its high transparency, it is suitable to be used as an optical material such as a light guide panel. However, in order to be used for this purpose, it must be excellent in heat resistance so that deformation does not occur by heat generated during operation of the optical device.

Therefore, there is a need for a new method for producing an acrylate-based polymer that can solve the problems of the prior art and improve the physical properties such as heat resistance and the like while making the manufacturing process easy.

The first technical problem to be achieved by the present invention is to provide a method for producing a high thermal stability acrylate polymer.

The second technical problem to be achieved by the present invention is to provide an acrylate polymer having high thermal stability.

The present invention to achieve the first technical problem,

Provided is a method for preparing polyalkyl (meth) acrylates wherein the alkyl (meth) acrylates are radically polymerized with an initiator in the presence of a Lewis acid catalyst.

According to one embodiment of the invention, the cation of the Lewis acid catalyst in the polyalkyl (meth) acrylate production method is scandium, titanium, vanadium, chromium, manganese, iron, cobalt, copper, zinc, boron, aluminum, yttrium And at least one cation selected from the group consisting of zirconium, niobium, molybdenum, cadmium, rhenium and tin.

According to another embodiment of the present invention, the anion of the Lewis acid catalyst in the polyalkyl (meth) acrylate production method is halide, triflate, HPO ₃ ^2- , H ₃ PO ^2- , CF ₃ COO ^- and SO It is preferably at least one anion selected from the group consisting of ₄ ^2- .

According to another embodiment of the present invention, it is preferable that the Lewis acid is used in an amount of 0.01 to 10 mol% based on the number of moles of the monomer in the polyalkyl (meth) acrylate manufacturing method.

According to another embodiment of the present invention, it is preferable that the alkyl (meth) acrylate is represented by the following Chemical Formula 1 in the polyalkyl (meth) acrylate manufacturing method:

<Formula 1>

Where

R ₁ , R ₂ and R ₃ are each independently a monovalent atomic group containing a hydrogen atom, a hydrocarbon group having 1 to 30 carbon atoms, or a hetero atom; R ₄ is a hydrogen atom or a methyl group.

According to another embodiment of the present invention, in the polyalkyl (meth) acrylate production method, R ₁ , R ₂ and R ₃ are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an aryl group, an arylalkyl group, It is preferable that they are a carboalkoxy group, a carbamoyl group, an amino substituted alkyl group, an amino group, an alkoxy substituted alkyl group, an alkoxy group, or a silyl group.

According to another embodiment of the present invention, in the polyalkyl (meth) acrylate production method, the solvent used for the radical polymerization in the group consisting of toluene, chlorobenzene, n-hexane, tetrahydrofuran, chloroform and methylene chloride It is preferred that it is at least one selected.

According to another embodiment of the present invention, the initiator in the polyalkyl (meth) acrylate production method is preferably used 0.1 to 5 parts by weight based on the total weight of the monomers.

According to another embodiment of the present invention, the radical polymerization in the polyalkyl (meth) acrylate production method is preferably carried out at 30 to 150 ℃.

The present invention to achieve the second technical problem,

Polyalkyl (meth) acrylates having a glass transition temperature of 90 to 150 ° C., a number average molecular weight of 5,000 to 150,000 and a weight average molecular weight of 10,000 to 500,000 are provided.

According to one embodiment of the invention, the polyalkyl (meth) acrylate is polymethyl methacrylate, the glass transition temperature is 120 to 150 ℃, the number average molecular weight is 10,000 to 100,000, the weight average molecular weight is 20,000 to It is preferred that it is 200,000.

According to another embodiment of the present invention, it is preferred that the polyalkyl (meth) acrylate is prepared by the method according to the above.

Hereinafter, the present invention will be described in more detail.

The present invention provides a method for producing an acrylate polymer having a high glass transition by radical polymerization in the presence of a Lewis acid catalyst, and provides an acrylate polymer having a higher glass transition temperature than a conventional acrylate polymerization method.

The present invention is a method for producing polyalkyl (meth) acrylates by radical polymerization of alkyl (meth) acrylates with an initiator in the presence of a Lewis acid catalyst.

The Lewis acid used in the polyalkyl (meth) acrylate production method is preferably a metal Lewis acid. In the polyalkyl (meth) acrylate production method, the cation of the Lewis acid catalyst is scandium, titanium, vanadium, chromium, manganese, iron, cobalt, copper, zinc, boron, aluminum, yttrium, zirconium, niobium, molybdenum, cadmium, It is preferably at least one cation selected from the group consisting of rhenium and tin. And, in the polyalkyl (meth) acrylate production method, the anion of the Lewis acid catalyst in the group consisting of halides, triflate, HPO ₃ ^2- , H ₃ PO ^2- , CF3COO ^- and SO ₄ ^2- It is preferred that it is at least one anion selected.

More specifically, the Lewis acid used in the present invention is boron trifluoride, ethyl boron trichloride, boron trifluoride, boron troboromide, boron triionide, aluminum trichloride, aluminum tribromide, ethyl aluminum dichloride Aluminum triflate, scandiqu triflate, copper with chlorides such as ethylaluminum sesquichloride, diethylaluminum chloride, stanic chloride, zinc dichloride, copper dichloride, nickel chloride and fluoride Lewis acids Lewis acids of a triflate family such as triflate, yttrium triflate, zinc triflate and the like can be used.

Mount Lewis is not limited to those listed above. The cation is an inorganic or organometallic compound selected from the group consisting of scandium, titanium, vanadium, chromium, manganese, iron, cobalt, copper, zinc, boron, aluminum, yttrium, zirconium, niobium, molybdenum, cadmium, rhenium and tin.

ZnBr ₂ , ZnI ₂ , ZnCl ₂ , ZnSO ₄ , CuCl ₂ , CuCl, Cu (O ₃ SCF ₃ ) ₂ , CoCl ₂ , CoI ₂ , FeI _{2 described in} US Pat. Nos. 6,127,567, 6,171,996 and 6,380,421 and the like. , FeCl ₃ , FeCl ₂ , FeCl ₂ (THF) ₂ , TiCl ₃ (THF) ₂ , TiCl ₄ , TiCl ₃ , ClTi (Oi-propyl) ₃ , MnCl ₂ , ScCl ₃ , AlCl ₃ , (C ₈ H ₁₇ ) AlCl ₂ , (C ₈ H ₁₇ ) ₂ AlCl, (iC ₄ H ₉ ) ₂ AlCl, (C ₆ H ₅ ) ₂ AlCl, (C ₆ H ₅ ) AlCl ₂ , ReCl ₅ , ZrCl ₄ , NbCl ₅ , VCl ₃ , CrCl ₂ , MoCl ₅ , YCl ₃ , CdCl ₂ , LaCl ₃ , Er (O ₃ SCF ₃ ) ₃ , Yb (O ₂ CCF ₃ ) ₃ , SmCl ₃ , B (C ₆ H ₅ ) ₃ and TaCl ₅ Can be mentioned.

Metal salts such as ZnCl ₂ , CoI ₂ and SnCl ₂ described in USP 3,496,217, 3,496,218 and 4,774,353, and the like, RAlCl ₂ , RSnO ₃ SCF ₃ and R ₃ B (where R is an alkyl group or an aryl group) The organometallic compound of is also preferable. According to USP No. 3,773,809 call, the anionic moiety is a fluoride, chloride, anions of lower fatty acid with a halide, from 2 to 7 carbon atoms, such as bromide and iodide, HPO ₃ ^2-, H ₂ PO ₃ ^-, CF ^{_{3 COO -, C 7 H 15}} OSO 2 - or may be selected from the group consisting of SO ₄ ^2-, and zinc, cadmium, beryllium, aluminum, gallium, indium, thallium, titanium, zirconium, hafnium, erbium, germanium, tin In the form of a cation selected from the group consisting of vanadium, niobium, scandium, chromium, molybdenum, tungsten, manganese, rhenium, palladium, thorium, iron and cobalt, preferably zinc, cadmium, titanium, tin, chromium, iron and cobalt It is also possible to use metals.

US Pat. No. 3,773,809 also discloses borohydrides, organoborohydrides and borate salts of formula R ₃ B or B (OR) ₃ as suitable promoters, wherein R is hydrogen, an aryl group having from 6 to 18 carbon atoms. , An aryl group substituted by an alkyl group having 1 to 7 carbon atoms, an aryl group substituted by a cyano-substituted alkyl group having 1 to 7 carbon atoms, advantageously selected from the group consisting of triphenylboron) Is disclosed.

The term Lewis acid of the present invention also includes the cocatalysts mentioned in USP 3,496,217, 3,496,218, 4,774,353, 4,874,884, 6,127,567, 6,171,996 and 6,380,421. .

Among the above-mentioned Lewis acids, in particular metal salts, particularly preferably metal halides, for example fluorides, chlorides, bromide and iodides, especially chlorides, among which aluminum (III) chloride, zinc chloride, iron (II) chloride And iron (III) chloride are particularly preferred.

In the polyalkyl (meth) acrylate production method, the Lewis acid is preferably used in an amount of 0.01 to 10 mol% based on the number of moles of the monomer. If the Lewis acid is less than 0.01 mol%, there is a problem that the rate of increase of the glass transition temperature is low, and if the Lewis acid is more than 10 mol%, the excess Lewis acid needs to be removed.

In the polyalkyl (meth) acrylate manufacturing method, the alkyl (meth) acrylate is preferably represented by the following formula (1):

<Formula 1>

Where

R ₁ , R ₂ and R ₃ are each independently a monovalent atomic group containing a hydrogen atom, a hydrocarbon group having 1 to 30 carbon atoms, or a hetero atom; R ₄ is a hydrogen atom or a methyl group.

In the polyalkyl (meth) acrylate production method, each of R ₁ , R ₂ and R ₃ is independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an aryl group, an arylalkyl group, a carboalkoxy group, a carbamoyl group, or an amino substitution. It is preferable that they are an alkyl group, an amino group, an alkoxy substituted alkyl group, an alkoxy group, or a silyl group. Particularly preferred alkyl (meth) acrylates are methyl (meth) acrylates (MMA).

Toluene, chlorobenzene, n-hexane, tetrahydrofuran, chloroform and methylene chloride are preferable as the solvent used for the radical polymerization in the polyalkyl (meth) acrylate production method.

In the polyalkyl (meth) acrylate production method, the initiator is preferably used in an amount of 0.1 to 5 parts by weight based on the total weight of the monomers. If the initiator is less than 0.1 part by weight, the yield is low, and if it exceeds 5 parts by weight, there is a problem that low molecular weight is formed.

The initiator is preferably a peroxide compound, an alkali metal persulfate, a perborate, a percarbonate, an azo compound and the like, but is not limited thereto. Any radical initiator used in the art may be used. A particularly preferred initiator is AIBN (2,2-azobisisobutylonitrile).

It is preferable that the said radical polymerization is performed at 30-150 degreeC in the said polyalkyl (meth) acrylate manufacturing method. In the case where the radical polymerization is performed at less than 30 ° C, there is a problem in that the initiator is not activated, and in the case of exceeding 150 ° C, the soluble solvent is limited.

The polymerization time can be changed depending on the reaction temperature and the concentration of the polymerization initiator.The higher the reaction temperature, the higher the concentration of the polymerization initiator, the shorter the polymerization time, and the lower the reaction temperature or the lower the concentration of the polymerization initiator. The reaction time is long. The reaction generally takes 5-30 hours, and in the present invention, the polymerization time is preferably 6-20 hours.

In the polymerization post-treatment process of the present invention, in order to remove the Lewis acid, a solution in which a chelate is dissolved in the polymerization product is added, reacted with Lewis acid, and then dissolved in a polar solvent. At this time, the polymer is not dissolved in the polar solvent, precipitation occurs and is obtained by filtration.

The drying temperature may be any temperature as long as the polymethyl methacrylate is not deformed, and the drying temperature and the drying time may be inversely changed.

The present invention provides a polyalkyl (meth) acrylate having a glass transition temperature of 90 to 150 ° C., a number average molecular weight of 5,000 to 150,000, and a weight average molecular weight of 10,000 to 500,000.

The present invention also provides a polymethyl (meth) acrylate having a glass transition temperature of 120 to 150 ° C, a number average molecular weight of 10,000 to 100,000, and a weight average molecular weight of 20,000 to 200,000.

The polyalkyl (meth) acrylates, in particular polymethyl (meth) acrylates, are preferably produced by the process according to the above.

Hereinafter, the present invention will be described in more detail with reference to the following examples. However, these Examples are only for illustrating the present invention and the present invention is not limited to these.

The glass transition temperature (Tg), which is a thermal property of the obtained polymethylmethacrylate (PMMA), was measured by DSC Q100 (TA Instryment).

Molecular weight and molecular weight distribution were analyzed by GPC (Waters). THF was used as a solvent at room temperature, and normalized with polystyrene to obtain a number average molecular weight (Mn) and a weight average molecular weight (Mw).

Preparation of Polymer

Example 1

Aluminum chloride was charged to an argon atmosphere reactor at a rate of 0.5 mol relative to 1 mol of MMA. The initiator AIBN dissolved in toluene was added at a rate of 0.8 mole to 100 moles of MMA. The reactor temperature was then raised to 60 ° C. and polymerization was carried out for 20 hours.

Example 2

Aluminum chloride was charged to an argon atmosphere reactor at a rate of 0.5 mol relative to 1 mol of MMA. The initiator AIBN dissolved in toluene was added at a rate of 0.5 moles to 100 moles of MMA. The reactor temperature was then raised to 70 ° C. and polymerization was carried out for 20 hours.

Comparative Example 1

The same procedure as in Example 2 was carried out except that aluminum chloride which was a Lewis acid was not added.

Comparative Example 2

 One type of commercial PMMA, IF 870, was used.

Property evaluation

Evaluation Example 1: Measurement of Glass Transition Temperature and Average Molecular Weight

The glass transition temperature (Tg), the number average molecular weight (Mn), and the weight average molecular weight (Mw) were calculated using the polymers prepared in Examples 1 to 2 and Comparative Example 1 and the commercial polymers of Comparative Example 2. The results are shown in Table 1 and FIGS.

Glass transition temperature [℃] Number average molecular weight (Mn) Weight average molecular weight (Mw) Polydispersity Index (PDI) Example 1 130.54 11000 22000 1.93 Example 2 120.1 13000 22000 1.66 Comparative Example 1 111.5 18000 29000 1.64 Comparative Example 2 115.8 16000 27000 1.68

As shown in Table 1, in the case of the examples showed a glass transition temperature of 120 to 130 ℃ depending on the reaction conditions. On the other hand, the comparative examples showed a glass transition temperature of about 110 to 116 ℃. Therefore, the production method of the present invention shows that a polymer having a higher glass transition temperature can be obtained compared to the conventional method. It also shows that it is possible to control the glass transition temperature of the polymer by controlling other polymerization conditions in the presence of a Lewis acid catalyst.

Evaluation Example 2 Dynamic Viscosity Measurement

The polymer prepared in Example 2 and the commercial PMMA polymer of Comparative Example 2 were prepared by applying a pressure of 5 kg / m ² at 180 ° C. for the first 5 minutes and then 20 kg / m ^{2 for} 15 minutes. And the rheometer of TA company was measured in the state which melt | dissolved the specimen at 200 degreeC. A 25mm paparell plate was used. Shear rate was 0.5 ~ 500 rad / s and torque was 0.02 ~ 2000 g / cm. The experimental results are shown in FIG. 3.

As shown in FIG. 3, the slope of the apparent viscosity graph for the polymer of Example 2 was greater than that of Comparative Example 2. Therefore, the polymer according to the present invention is judged to be excellent in processability and productivity in spite of the higher glass transition temperature than the polymer prepared by the prior art.

According to the method for producing the acrylate polymer of the present invention can be obtained an acrylate polymer having a higher glass transition temperature than the conventional polymerization method and excellent in processability.

Claims (12)

A method for producing a polyalkyl (meth) acrylate, wherein the alkyl (meth) acrylate is radically polymerized with an initiator in the presence of a Lewis acid catalyst. The method of claim 1, wherein the cation of the Lewis acid catalyst is made of scandium, titanium, vanadium, chromium, manganese, iron, cobalt, copper, zinc, boron, aluminum, yttrium, zirconium, niobium, molybdenum, cadmium, rhenium, and tin. Polyalkyl (meth) acrylate production method characterized in that the at least one cation selected from the group. According to claim 1, wherein the anion of the Lewis acid catalyst is at least one anion selected from the group consisting of halides, triflate, HPO ₃ ^2- , H ₃ PO ^2- , CF ₃ COO ^- and SO ₄ ^2- The polyalkyl (meth) acrylate manufacturing method characterized by the above-mentioned. The method according to claim 1, wherein the Lewis acid is used in an amount of 0.01 to 10 mol% based on the number of moles of the monomers. The method of claim 1, wherein the alkyl (meth) acrylate is represented by the following formula (1): <Formula 1>

Where R ₁ , R ₂ and R ₃ are each independently a monovalent atomic group containing a hydrogen atom, a hydrocarbon group having 1 to 30 carbon atoms, or a hetero atom; R ₄ is a hydrogen atom or a methyl group. 6. The compound of claim 5, wherein R ₁ , R ₂ and R ₃ are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an aryl group, an arylalkyl group, a carboalkoxy group, a carbamoyl group, an amino substituted alkyl group, an amino group, or alkoxy. It is a substituted alkyl group, an alkoxy group, or a silyl group, The manufacturing method of polyalkyl (meth) acrylate characterized by the above-mentioned. The polyalkyl (meth) acrylate preparation according to claim 1, wherein the solvent used for the radical polymerization is at least one selected from the group consisting of toluene, chlorobenzene, n-hexane, tetrahydrofuran, chloroform and methylene chloride. Way. The method of claim 1, wherein the initiator is used in an amount of 0.1 to 5 parts by weight based on the total weight of the monomers. The method for producing polyalkyl (meth) acrylate according to claim 1, wherein the radical polymerization is carried out at 30 to 150 ° C. A polyalkyl (meth) acrylate having a glass transition temperature of 90 to 150 ° C, a number average molecular weight of 5,000 to 150,000, and a weight average molecular weight of 10,000 to 500,000. The method of claim 10, wherein the polyalkyl (meth) acrylate is polymethyl methacrylate, the glass transition temperature is 120 to 150 ℃, the number average molecular weight is 10,000 to 100,000, the weight average molecular weight is 20,000 to 200,000 Polyalkyl (meth) acrylate characterized by the above-mentioned. The polyalkyl (meth) acrylate according to claim 10 or 11, wherein the polyalkyl (meth) acrylate is prepared by the method according to any one of claims 1 to 9.

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