KR101147463B1 - Polymer Bead particle containing Norbornene derivatives - Google Patents

Abstract

The present invention relates to a polymer bead particle prepared by using dispersion polymerization or suspension polymerization, and containing 0.01 to 99.99 mol% of a norbornene derivative represented by Formula 1, wherein the polymer bead particle includes a norbornene derivative in a predetermined amount. Since it has a particle distribution of the desired particle size, such as mono-dispersion and polydispersion, it is not only applicable to a variety of applications depending on the use, but also easy to apply to optical materials because it contains a norbornene derivative having a high refractive index, high transparency properties.

Formula 1

In the above formula, R ₁ , R ₂ , R ₃ and R ₄ are each or simultaneously hydrogen atoms, alkyl groups, alkoxy groups, alkylcarbonyloxy groups, halogen atoms or vinyl groups.

Polymer * Beads * Particles * Norbornene *

Description

Polymer bead particles containing norbornene derivatives

The present invention relates to a polymer bead particle comprising a norbornene derivative, and more particularly, it is possible to prepare a polymer bead particle having various particle size distribution by including a norbornene derivative in a predetermined amount.

Generally, methods such as suspension polymerization, dispersion polymerization, and emulsion polymerization have been used to prepare organic polymer beads.

In the case of the micron (μm) sized acrylic polymer beads, which are widely used as the polymer beads for optical optics, they are widely used for the polymerization of polydisperse beads having a relatively large particle size distribution through suspension polymerization, and the dispersion of monodisperse beads having a small particle size distribution through dispersion polymerization. It is used a lot in manufacturing.

Generally, polymer beads having a particle size of about 1-100 μm are used in many industrial fields.

In the method for producing polymer beads using suspension polymerization, the polymer particles are prepared by dispersing the monomer present in the aqueous solution by mechanical force. The polymer particles produced by this method have a particle size of at least μm or more, and the particle distribution tends to be wide because the particles are dispersed by mechanical force. Therefore, a separate device is required to control the particle size and particle distribution.

In this regard, US Pat. Nos. 4,017,670, 4,071,670, 4,085,169, 4,129,706, and the like introduce techniques for producing polystyrene polymer beads by suspension polymerization.

In addition, the dispersion polymerization is carried out in a medium in which the monomer to be polymerized can be dissolved, and the polymer produced is not dissolved in the medium. In addition, since this method has a high aggregation rate, the degree of crosslinking of the produced polymer beads is less than 2%, and when the polymer beads having a particle size of 10 µm or larger are produced, the particle distribution is wide.

Emulsion polymerization is a method of producing polymer beads in an aqueous solution using a water-soluble initiator, an emulsifier, and a monomer. By the use of an emulsifier, the particle distribution is narrow, and polymer beads having a particle size of 1 µm or less are produced. In this regard, US Pat. No. 4,522,953 introduces a technique for producing porous polystyrene polymer beads by emulsion polymerization.

Beads which are widely used for optics are mainly polystyrene beads and poly methyl methacrylate beads. However, with various display technologies, beads of various refractive indices and transmittances are required.

Therefore, the inventors of the present invention, while studying the solution in various directions to prepare polymer beads that can overcome the problems of insufficient heat resistance, various refractive index, high strength of the conventional polymethyl methacrylate or polystyrene beads, norbornene derivatives during monomer manufacturing After dissolving together to prepare a copolymerization monomer solution and then subjected to suspension polymerization or dispersion polymerization, it was found that coarse polymer bead particles having a desired particle size normal distribution after polymerization were completed.

Accordingly, it is an object of the present invention to provide polymer bead particles containing high refractive index and high transparency norbornene derivatives using suspension polymerization and dispersion polymerization.

The polymer bead particle including the norbornene derivative of the present invention as described above is characterized by including the norbornene derivative represented by the following formula (1) in an amount of 0.01 to 99.99 mol%.

In the above formula, R ₁ , R ₂ , R ₃ and R ₄ are each or simultaneously hydrogen atoms, alkyl groups, alkoxy groups, alkylcarbonyloxy groups, halogen atoms or vinyl groups.

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

Polymer bead particles comprising the norbornene derivatives of the present invention may be prepared using suspension polymerization and dispersion polymerization.

(1) Preparation of Polymer Bead Particles Using Suspension Polymerization

First, the process of preparing the polymer bead particles of the present invention using suspension polymerization is a step 1 to prepare a monomer system which is a copolymerized monomer mixed solution by dissolving the monomer and the monomer and norbornene derivative dissolved in the monomer together with a crosslinking agent, in ion-exchanged water. Step 2 to prepare a water-based polymer by dissolving a water-soluble polymer as a granular stabilizer, and a suspension obtained by dispersing the monomer-based and water-based systems by mechanical force is heated to an internal temperature of 50 ~ 90 ℃, adding a fat-soluble initiator, and finally polymerized 1㎛ ~ 100 The third step is to prepare a polymer bead having a particle size of μm.

In the first step, in order to control the viscosity and specific gravity of the monomer system, the monomer dissolved in the monomer is dissolved in the monomer in an amount of 1 to 50% by weight, and the crosslinking agent is 0.01 to 100 parts by weight of the monomer and the monomer dissolved in the monomer. A monomer mixed solution containing 1 part by weight and a norbornene derivative is prepared.

Monomers serving as the solvent include (meth) acrylic acid esters such as methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, and 2-ethylhexyl (meth) acrylate, aromatic vinyl monomers selected from α-methylstyrene and the like; Acrylic acid or methacrylic acid alkyl ester monomers having 1 to 20 carbon atoms selected from acrylic acid, methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate and n-butyl acrylate; 0.01 / 99.9 to 99.9 / 0.01 mol% of at least one compound selected from methacryl fluoroalkyl ester monomers having 1 to 20 carbon atoms selected from 2,2,2-trifluoroethyl methacrylate, and norbornene derivatives. Mix with and use.

The norbornene derivatives specifically included as monomer components in the present invention have a bicyclic structure represented by the following Chemical Formula 1, and the official IUPAC name of norbornene is Bicyclo [2.2.1] hept-2-ene, which has high refractive index and high transparency. Therefore, it is a material that has recently been spotlighted as an optical material. The chemical formula of the norbornene derivative is as follows.

Formula 1

In the above formula, R ₁ , R ₂ , R ₃ and R ₄ are each or simultaneously hydrogen atoms, alkyl groups, alkoxy groups, alkylcarbonyloxy groups, halogen atoms or vinyl groups.

In the present invention, the inclusion of a norbornene derivative, which has been spotlighted as an optical material in the structure of polymer bead particles, is expected to be applicable to various electronic materials because it has high refractive index and high transparency characteristics.

In addition, the monomer dissolved in the monomer for viscosity and specific gravity control may be the same as the compound used as the monomer, or may be used by mixing a compound selected from alkyl methacrylate, alkyl acrylate.

In addition, the polymerization initiator is preferably a fat-soluble initiator, for example, benzoyl peroxide, azobisisobutyronitrile, azobismethylbutyronitrile, azobiscyclohexanecarbonitrile and the like, the content of which is 100% of the monomer mixed solution. 0.01-1 weight part is preferable normally with respect to a weight part.

As crosslinking agent, 1, 2- ethanediol diacrylate, 1, 3- propanediol diacrylate, 1, 3- butanediol diacrylate, 1, 4- butanediol diacrylate, 1, 5- pentanediol diacrylate 1,6-hexanediol diacrylate, divinylbenzene, ethylene glycol diacrylate, propylene glycol diacrylate, butylene glycol diacrylate, triethylene glycol diacrylate, polyethylene glycol diacrylate, polypropylene glycol Diacrylate, polybutylene glycol diacrylate, allyl acrylate, 1,2-ethanediol dimethacrylate, 1,3-propanediol dimethacrylate, 1,3-butanediol dimethacrylate, 1, 4-butanediol dimethacrylate, 1,5-pentanediol dimethacrylate, 1,6-hexanediol dimethacrylate, ethylene glycol dimethacrylate, propylene glycol dimethacrylate, butylene glycol dimethacrylate relay At least one selected from triethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, polypropylene glycol dimethacrylate, polybutylene glycol dimethacrylate, allyl methacrylate and diallyl maleate, and It is preferable to use content in 1-60 weight part with respect to 100 weight part of all monomer mixed solutions.

In the second step, a polymer stabilizer is added as a granular stabilizer to ensure polymerization stability in ion-exchanged water. The ion-exchanged water used is pure water having a resistance value of 5 megaohms (MΩ) or more under a nitrogen stream generated through an ion exchanger, and is used in an amount of 100 to 500 parts by weight based on 100 parts by weight of the total monomers in the first step.

The polymer stabilizer is selected from polyvinyl alcohol, methyl cellulose, ethyl cellulose, sodium carboxy methyl cellulose, polyacrylic acid, polymethacrylic acid, sodium polyacrylate, sodium polymethacrylate, gelatin, polyacrylamide and polyethylene oxide. It is preferable that the content is 0.2-20.0 weight part with respect to 100 weight part of monomer solutions.

In the third step, the monomer system prepared in step 1 and the aqueous system prepared in step 2 are stirred by mechanical force, the monomer system is dispersed, and the temperature is increased to 50 to 90 ° C. to finally obtain a polymer having a particle size of 1 μm to 100 μm. Manufacturing step. After the reaction is completed, the suspension is dehydrated by centrifugation or the like, washed several times with ion-exchanged water, and then dried in a vacuum dryer to obtain a final product.

(2) Preparation of Polymer Bead Particles Using Dispersion Polymerization

On the other hand, in the case of the monodisperse polymer beads of the present invention using dispersion polymerization is prepared through the following process.

First, dissolve the preparation by dissolving the oil-soluble initiator completely in an amount of 0.01 to 1 parts by weight relative to the total monomers in the monomer solution of 0.01 / 99.99 to 99.99 / 0.01 mol% of the same monomers and norbornene derivatives used in the suspension polymerization. It is added to a closed reactor containing a dispersion medium and stabilized by stirring for about 1 hour in a nitrogen atmosphere.

The monomers and norbornene derivatives have the same compounds and contents as those used in the suspension polymerization. In addition, as a dispersion medium, an alcohol and an aqueous solution of alcohol may be used. Specifically, aliphatic alcohols such as methanol, ethanol, 1-propanol, 2-propanol, and isopropanol Ryu; Ketones such as acetonitrile, acetone, dimethyl ketone, and methyl ethyl ketone are used.

The dispersion stabilizer is a polymer stabilizer that can be dissolved in an alcohol phase or an aqueous phase. Specifically, gelatin, starch, hydroxyethyl cellulose, carboxymethyl cellulose polyvinylpyrrolidone, polyvinyl alkyl ether, polyvinyl alcohol, polydimethylsilonic acid -Polystyrene copolymer or the like can be applied.

The polymerization initiator used as an initiator of the polymerization reaction is conventionally known, and one or a mixture of two or more selected from a peroxide, an azo compound, a percarbonate compound, and a perester compound can be used. Specifically, acetylcyclohexylsulfonyl peroxide, 2,4,4-trimethylpentyl-2-peroxyphenoxyacetate, benzoyl peroxide, 2,2- azobisisobutyronitrile, azobis-2,4 Dimethylvaleronitrile or t-butyl peroxyneodecanate can be selected and used.

The stabilized reaction is then polymerized for 20-30 hours with stirring at 100-300 rpm at a temperature of 50-70 ° C. The prepared monodisperse uncrosslinked polymer particles are washed several times by centrifugation or vacuum washing to remove dispersion stabilizers remaining on the surfaces of the particles. The polymer particle cake thus prepared is dried under reduced pressure at room temperature to 50 ° C. to obtain a powder.

In step 2, the fine powder obtained by performing step 1 is subdivided, dispersed in ion-exchanged water, and then swelled to the monodisperse uncrosslinked particles and the friendly crosslinking agent and monomer.

Specifically, the crosslinking agent and the monomer to be swelled, the oil-soluble initiator and the ion-exchanged water are put into one vessel and stirred at high speed at about 400 to 700 rpm. The aqueous-monomer suspension thus prepared is added to the water-dispersed uncrosslinked monomer particle system and left at 100 to 300 rpm for about 20 to 30 hours at swelling.

In the present invention, 0.01 to 1 parts by weight of the polymerization inhibitor is added to the total aqueous mass in the process of preparing the water dispersion uncrosslinked particle system. This polymerization inhibitor selectively acts only in the water phase to prevent unwanted polymerization that can occur in three stages of polymerization. As such a polymerization inhibitor, potassium dichromenite, ammonium thiocyanate, sodium nitrite, or the like may be used.

The crosslinking agent used to increase the degree of crosslinking is 1,2-ethanediol diacrylate, 1,3-propanedioldiacrylate, 1,3-butanedioldiacrylate, 1,4-butanedioldiacrylate, 1,5- Pentanediol diacrylate, 1,6-hexanediol diacrylate, divinylbenzene, ethylene glycol diacrylate, ethylene glycol dimethacrylate, propylene glycol diacrylate, butylene glycol diacrylate, triethylene glycol di At least one selected from acrylate, polyethylene glycol dimethacrylate, polypropylene glycol dimethacrylate, polybutylene glycol dimethacrylate, allyl methacrylate, and diallyl maleate, and the content thereof is a total monomer mixed solution. It is 1-60 weight part with respect to 100 weight part.

In addition to the crosslinking agent, it may also include a monomer as a piece welling material, specifically, the same component as the monomer used in step 1.

The two stage oil-soluble initiators are also identical to the materials adopted in stage one.

In step 3, the swelled monodisperse particles prepared in the process up to step 2 are polymerized to obtain final crosslinked monodisperse particles. Agglomeration between particles may occur during the polymerization of the swelled monodisperse particles, and monomers which do not penetrate into the particles in the piecewelling material may be polymerized in an undesired region. In order to prevent this phenomenon, an aqueous polymerization inhibitor and a dispersion stabilizer are added. The aqueous polymerization inhibitor is already included in the second step, and in the third step, a small amount of the dispersion stabilizer is added before the polymerization.

Dispersion stabilizers include polyvinyl alcohol, methyl cellulose, ethyl cellulose, sodium carboxymethyl cellulose, polyacrylic acid, polymethacrylic acid, sodium polyacrylate, sodium polymethacrylate, gelatin, poly Acrylamide and polyethylene oxide may be used, and the content thereof is preferably 0.01 to 5 parts by weight based on the total mass of the aqueous system.

In addition, the water system used for swelling is pure water having a resistance value of 5 megohms or more under a nitrogen stream generated through an ion exchanger, and may be 100 to 500 parts by weight based on the total monomers.

Through the above three steps, cross-linked monodisperse polymer particles can be obtained, and the obtained particles have excellent short dispersibility because the particles produced by the conventional polymerization method have significantly less aggregation between particles.

Hereinafter, the present invention will be described in more detail with reference to the following Examples and Comparative Examples, which are not intended to limit the present invention.

Example 1 Preparation of Polymer Bead Particles Using Suspension Polymerization

In a 2 L flask, 100 g (104 mol%) of norbornene was stirred in 200 g (199.8 mol%) of methyl methacrylate and 10 g (7.8 mol%) of monomer butyl acrylate soluble in monomers, followed by 1,6-hexanediol diacrylate. After dissolving 10 g (4.4 mol%) to prepare a monomer phase, 700 g of ion-exchanged water was added to a 2 L reactor to prepare an aqueous phase in which 45 g of polyvinyl alcohol was dissolved as a polymer stabilizer under a nitrogen stream. The previously prepared monomer phase was added to the aqueous phase, followed by high speed stirring to form a suspension.

After the reactor was heated to a temperature of 60 ° C. under a nitrogen stream, 0.5 g of azobisisobutyronitrile, an azonitrile-based initiator, was added and polymerized for 6 hours. Thereafter, the temperature was raised to 80 ° C. and polymerization was performed for 3 hours. The obtained polymer suspension was dehydrated, washed and separated by a centrifuge, and then dried in a vacuum dryer to less than 0.5% of moisture to prepare polydisperse particles.

The particle size distribution of the obtained particles was measured using a Multisizer3, and as a result, the particles had an average particle diameter of 11.5 µm and a dispersion index of CV (Coefficient of Variance) of 27.0%.

Example 2

Polymer beads were prepared in the same manner as in Example 1, except that 1.0 g of azobisisobutyronitrile was added to prepare final polydisperse particles.

The particle size distribution of the obtained particles was measured using a Multisizer3, and as a result, the particles had an average particle diameter of 11.0 µm and a dispersion index of CV (Coefficient of Variance) of 31.5%.

Example 3 Preparation of Polymer Bead Particles Using Dispersion Polymerization

In the first step, 50 g (52 mol%) of norbornene was thoroughly mixed with 50 g of methyl methacrylate (49.9 mol%) and 1 g of azobisbutyronitrile. It was stabilized for 1 hour. The stabilized reaction was then warmed to a temperature of 55 ° C. and polymerized for 24 hours at 150 stirring speeds per minute. The uncrosslinked polymer particles thus prepared were subjected to vacuum washing three times using an aspirator to remove polyvinylpyrrolidone, which is a dispersion stabilizer, remaining on the surface of the particles.

The uncrosslinked monodisperse particles in the dried cake state were vacuum dried at 55 ° C. to obtain monodisperse polymer particles in the form of fine powder. The particle size distribution of the obtained particles was measured using a Multisizer3, and the average particle diameter was 10 µm and the dispersion index CV (Coefficient of Variance) was 9.8%.

Subsequently, 80 g (23.5% by mass of ion-exchanged water) of the particles obtained in step 1 were subdivided and dispersed in 340 g of ion-exchanged water, and 3.2 g of potassium dichromate was dissolved as a polymerization inhibitor. In another vessel, 20 g of norbornene, 40 g of ethylene glycol dimethacrylate, and 0.15 g of azobisbutyronitrile were mixed together, 180 g of ion-exchanged water was added, and homogenized by high speed stirring at 600 times per minute.

This homogenized preparation was placed in an aqueous dispersion of uncrosslinked particles and stabilized at a stirring speed of 150 times per minute. The prepared solution prepared by the above procedure was left for 24 hours at a stirring speed of 150 times per minute at 30 ° C to swell the uncrosslinked particles.

In step 3, 2.6 g of polyvinyl alcohol is added to the reaction product prepared in step 2 as a stabilizer, and the particles are stabilized, and then crosslinked and monodispersed by polymerization at a stirring speed of 150 times per minute at 55 ° C for 4 hours and 90 ° C for 4 hours. The particles were obtained. The crosslinked particles thus obtained were analyzed by Multisizer 3 and had an average particle diameter of 10.5 µm and a dispersion index of CV (Coefficient of Variance) of 9.9%.

Comparative Example 1

Polymer beads were prepared in the same manner as in Example 1, except that 300 g of methyl methacrylate was used instead of norbornene to prepare a monomer solution.

The particle size distribution of the obtained particles was measured using a Multisizer 3, and as a result, the particles had an average particle diameter of 25.8 µm and a dispersion index of CV (Coefficient of Variance) of 56.0%. In addition, the final polymerization agglomeration amount of 180g occurred.

Comparative Example 2

Polymer beads were prepared in the same manner as in Example 3, except that methylmethacrylate was used instead of norbornene in the first step.

The crosslinked particles thus obtained had values of an average particle diameter of 11.3 µm and a dispersion index of CV (Coefficient of Variance) of 16.0%.

Comparative Example 3

Polymer beads were prepared in the same manner as in Comparative Example 2, except that the polymerization was carried out without adding the aqueous polymerization inhibitor in the second step.

The crosslinked particles thus obtained had values of an average particle diameter of 10.7 µm and a dispersion index of CV (Coefficient of Variance) of 13.5% as analyzed by Multisizer3.

Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Average particle size (㎛) 11.5 11.0 10.5 25.8 11.3 10.7 C.V (%) 27.0 31.5 9.9 56.0 16.0 13.5 Coagulation amount (g) 1.0 0.5 0.5 180.0 32.5 14.0

As can be seen from the above examples and comparative examples, the average particle diameter of the prepared norbornene copolymer polymer beads is 10 μm and the particle size distribution can be obtained not only beads having polydispersity but also polymer beads showing monodispersion. I could confirm it. Moreover, it had monodispersity superior to the particle size analysis result when a polymerization inhibitor was not added.

As described in detail above, as a result of preparing the polymer bead particles including the norbornene derivative in the molecule as in the present invention, it is possible to produce polymer beads having various particle sizes of monodispersion and polydispersion, which is suitable for various applications. Available for the material.

Claims (2)

Norbornene derivatives represented by Formula 1, and Methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, styrene, α-methylstyrene, acrylic acid, methyl acrylate, ethyl acrylate, n acrylic acid A monomer selected from -propyl, isopropyl acrylate, n-butyl acrylate and 2,2,2-trifluoroethyl methacrylate. 0.01 / 99.9 to 99.9 / 0.01 mol%, Polymer bead particles further comprising any one selected from alkyl methacrylate and alkyl acrylate as a monomer dissolved in the monomer for controlling viscosity and specific gravity. Formula 1

In the above formula, R ₁ , R ₂ , R ₃ and R ₄ are each or simultaneously hydrogen atoms, alkyl groups, alkoxy groups, alkylcarbonyloxy groups, halogen atoms or vinyl groups. The polymer bead particle of claim 1, wherein the polymer bead particle is prepared by suspension polymerization or dispersion polymerization.