JP2005008724A - Method for producing additive-containing polymer particle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing additive-containing polymer particles by entirely impregnating polymer particles with an additive dissolved in a solvent. <P>SOLUTION: The method for producing the additive-containing polymer particles comprises the following procedure: Polymer particles are dispersed in an organic solvent followed by dissolving a hydrophobic additive( a phenolic antioxidant ) in the solvent. Water is then added to the resultant organic solvent mixture while removing the organic solvent to impregnate the polymer particles with the hydrophobic additive. In the above procedure, the organic solvent mixture is obtained, for example, by adding the hydrophobic additive to a polymerization mixture obtained by dispersion polymerization of a vinyl monomer in the organic solvent. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
[Technical field to which the invention belongs]
The present invention relates to a method for producing additive-containing polymer particles.
[0002]
[Prior art]
The additive-containing polymer particles in which an additive is contained in the polymer particles are useful as a modifier for a thermoplastic resin film. As a method for producing such additive-containing polymer particles, Patent Document 1 (Japanese Patent Application Laid-Open No. 11-12327) discloses that an additive is added to polymer particles by immersing the polymer particles in a solvent in which the additive is dissolved. The additive-containing polymer particles obtained are taken out of the solvent by filtration immediately after immersion.
[0003]
However, in such a conventional manufacturing method, the ratio of the additive that can be impregnated into the polymer particles out of the additive dissolved in the solvent is small, and many of the additives dissolved in the solvent are wasted. was there.
[0004]
[Patent Document 1] Japanese Patent Application Laid-Open No. 11-012327 [Patent Document 2] Japanese Patent Application Laid-Open No. 10-218935
[Problems to be solved by the invention]
Therefore, as a result of intensive investigations to develop a method for efficiently producing an additive-containing polymer by impregnating polymer particles without waste with an additive dissolved in a solvent, the present inventors have found that a hydrophobic as an additive. If the organic solvent is removed and water is added from the organic solvent mixture in which the additive is dissolved in the organic solvent and the polymer particles are dispersed, more additive is added to the polymer. The inventors have found that the particles can be easily impregnated and have reached the present invention.
[0006]
[Means for Solving the Problems]
That is, in the present invention, polymer particles are dispersed in an organic solvent, and water is added while removing the organic solvent from the organic solvent mixture in which the hydrophobic additive is dissolved, and the hydrophobic additive is impregnated into the polymer particles. The present invention provides a method for producing additive-containing polymer particles.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
The organic solvent mixture used in the production method of the present invention is one in which polymer particles are dispersed in an organic solvent.
[0008]
The polymer particles are particulate polymers, and examples of the polymer include a polymer obtained by polymerizing a vinyl monomer having a double bond capable of radical polymerization in the molecule.
[0009]
Examples of the vinyl monomer include a vinyl monofunctional monomer having one double bond capable of radical polymerization in the molecule. Examples of the vinyl monofunctional monomer include methacrylic acid, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, t-butyl methacrylate, and methacrylic acid 2 -Methacrylate monomers such as ethylhexyl, stearyl methacrylate, glycidyl methacrylate, 2-hydroxyethyl methacrylate,
Acrylic acid, methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, t-butyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, glycidyl acrylate Acrylic acid monomers such as 2-hydroxyethyl acrylate,
Aromatic vinyl monomers such as styrene, α-methylstyrene, ethylstyrene chlorostyrene, vinylpyridine,
Amido vinyl monomers such as methacrylonitrile and acrylonitrile,
Carboxylic acids such as maleic acid and itaconic acid,
Examples thereof include carboxylic acid anhydrides such as maleic anhydride and itaconic anhydride. Such vinyl monofunctional monomers may be used alone or in combination of two or more.
[0010]
The polymer may be obtained by polymerizing such a vinyl monofunctional monomer alone, or obtained by copolymerizing a vinyl monofunctional monomer with a vinyl polyfunctional monomer. A copolymer may also be used.
[0011]
Examples of vinyl polyfunctional monomers include divinylbenzene, trivinylbenzene, ethylene glycol dimethacrylate, ethylene glycol diacrylate, polyethylene glycol dimethacrylate, polyethylene glycol diacrylate, propylene glycol dimethacrylate, propylene glycol diacrylate, and polypropylene glycol diacrylate. Methacrylate, polypropylene glycol diacrylate, 1,4-butanediol dimethacrylate, 1,4-butanediol diacrylate, allyl methacrylate, allyl acrylate, allyl cinnamate, trimethylolpropane trimethacrylate, trimethylolpropane triacrylate, trimethylol Triaryl melitrate, diallyl maleate, pentaerythritol tetramethac Rate, include pentaerythritol tetraacrylate, and these are used alone or in combination of two or more, respectively.
[0012]
The particle diameter of such polymer particles is usually about 0.1 μm to 5 mm, and is preferably about 1 mm or less in terms of uniform impregnation. As such polymer particles, those produced by, for example, a dispersion polymerization method, an emulsion polymerization method, a suspension polymerization method or the like may be used as they are. Moreover, you may grind | pulverize and obtain the polymer obtained by methods, such as said method and cast polymerization method. The polymer may be produced by heating and melting and molding the polymer into granules such as pellets. The shape of the polymer particles may be true spherical or cylindrical. Moreover, the shape grind | pulverized to the irregular shape may be sufficient.
[0013]
As the organic solvent, those that do not dissolve the polymer particles are used, preferably those that can swell the polymer particles, and are appropriately selected according to the type of the polymer particles. Specific examples of the organic solvent include alcohols such as methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, and t-butanol,
Ether alcohols such as methyl cellosolve, cellosolve, butyl cellosolve,
Ketones such as acetone and methyl ethyl ketone,
Examples include hydrocarbons such as hexane, octane, petroleum ether, benzene, and toluene. Each is used alone or in combination of two or more. When two or more are used in combination, they are usually soluble in each other. Possible organic solvents are used.
[0014]
The amount of the organic solvent used is usually about 1 to 100 times, preferably about 2 to 30 times the polymer particles.
[0015]
In such an organic solvent mixture, the hydrophobic additive is dissolved in the organic solvent. The hydrophobic additive is an additive having a greater solubility in an organic solvent than in water, and is appropriately selected and used depending on the intended physical properties. For example, when it is desired to impart heat resistance stability to the polymer particles, an antioxidant, preferably a phenolic antioxidant is used. When it is desired to color the polymer particles, a dye is used. A flame retardant is used when imparting flame retardancy. When it is desired to impart plasticity, a plasticizer is used. When it is desired to absorb ultraviolet rays, an ultraviolet absorber is used.
[0016]
Examples of the hydrophobic phenolic antioxidant include 1,3,5-tris [(4-tert-butyl-3-hydroxy-2,6-xylyl) methyl] -1,3,5-triazine-2, 4,6 (1H, 3H, 5H) -trione, 1,3,5-tris (3,5-di-t-butyl-4-hydroxybenzyl) -1,3,5-triazine-2,4,6 (1H, 3H, 5H) -trione, octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate, pentaerythritol tetrakis [3- (3,5-di-t-butyl-4 -Hydroxyphenyl) propionate], ethylenebis (oxyethylene) bis [3- (5-tert-butyl-4-hydroxy-m-tolyl) propionate], 3,3 ', 3 ", 5,5', 5" -Hexa-t-bu Ru-a, a ', a "-(mesitylene-2,4,6-triyl) tri-p-cresol, hexamethylene bis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate Thiodiethylene bis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate, 2,6-di-t-butyl-4-methylphenol, 2,2′-methylene bis (6-t -Butyl-4-methylphenol), 4,4'-butylidenebis (6-tert-butyl-3-methylphenol), 4,4'-thiobis (6-tert-butyl-3-methylphenol), 3,9 -Bis [2- [3- (3-t-butyl-4-hydroxy-5-methylphenyl) propionyloxy] -1,1-dimethylethyl] -2,4,8,10-tetraoxaspiro [5・ 5] Eun Can, 2-t-butyl-6- (3-t-butyl-2-hydroxy-5-methylbenzyl) -4-methylphenyl acrylate, 2- [1- (2-hydroxy-3,5-di-t -Pentylphenyl) ethyl] -4,6-di-t-pentylphenyl acrylate, etc., each of which is used alone or in combination of two or more, and used as an additive in polymer particles. Many of these are hydrophobic additives.
[0017]
The amount of the hydrophobic additive used varies depending on the type and purpose of the hydrophobic additive used, but is usually about 0.001 to 30 parts by mass per 100 parts by mass of the polymer particles. In the case of an agent, it is preferably about 0.01 to 1 part by mass.
[0018]
Such an organic solvent mixture may be, for example, a polymerization mixture containing polymer particles obtained by a dispersion polymerization method of a vinyl monomer in an organic solvent. In order to disperse and polymerize a vinyl monomer in an organic solvent, for example, the vinyl monomer can be dissolved as an organic solvent, and an organic solvent that does not dissolve the polymer particles is used, and the vinyl monomer is polymerized in the organic solvent. You can do it.
[0019]
Examples of the organic solvent include the same organic solvents as described above in the organic solvent mixture.
[0020]
For polymerization, for example, an organic solvent and a vinyl monomer are mixed, heated to the polymerization temperature, and then a polymerization initiator is added at the polymerization temperature.
[0021]
As the polymerization initiator, for example, a radical polymerization initiator can be used. A radical polymerization initiator is a compound that decomposes itself to generate radicals, and initiates polymerization of a vinyl monomer by the generated radicals.
[0022]
Examples of such radical polymerization initiators include lauroyl peroxide, benzoyl peroxide, di-t-butyl peroxide, t-butyl peroxy 2-ethylhexanoate, t-butyl peroxyisobutyrate, and t-butyl peroxide. Peroxide radical polymerization such as oxyneodecanoate, t-butyl peroxypivalate, t-butyl peroxybenzoate, t-butyl peroxyacetate, diisopropyl peroxydicarbonate, disec-butyl peroxydicarbonate Initiator,
Azo radical polymerization initiators such as 2,2′-azobisisobutyronitrile and 2,2′-azobis (2,4-dimethylvaleronitrile) are usually used, and the amount used is 100% of vinyl monomer. The amount is usually 1 part by mass to 5 parts by mass per part by mass.
[0023]
The polymerization is usually performed in the presence of a dispersion stabilizer. The dispersion stabilizer is to prevent the polymer particles produced by polymerization from aggregating with each other in an organic solvent, and is preferably one that aggregates the polymer particles in water. Such a dispersion stabilizer is appropriately selected and used according to the type of organic solvent to be used, the type of vinyl monomer, and the like. For example, an alcohol having about 1 to 4 carbon atoms is used as the organic solvent, and methacryl is used as the vinyl monomer. When an acid monomer is used as a main component, cellulose derivatives such as hydroxypropyl cellulose, hydroxyethyl cellulose, carboxymethyl cellulose, and methoxy cellulose can be used.
[0024]
The polymerization initiator may be added all at once or may be gradually added. The polymerization temperature varies depending on the type of organic solvent used, the type of vinyl monomer, the type and amount of polymerization initiator used, and is usually about 50 ° C to 100 ° C. The vinyl monomer may be polymerized in the presence of water.
[0025]
Thus, the vinyl monomer is polymerized to obtain a polymer, but the produced polymer is not dissolved in the organic solvent, and thus becomes particulate and dispersed in the organic solvent. The total amount (100% by mass) of the vinyl monomer may be polymerized, but practically, 70% by mass or more, preferably 90% by mass or more of the vinyl monomer may be polymerized.
[0026]
Thus, the vinyl monomer is polymerized in an organic solvent to produce polymer particles, and a slurry-like polymerization mixture can be obtained. The obtained polymerization mixture can be used as it is in the production method of the present invention by adding a hydrophobic additive as it is. Further, in the dispersion polymerization, a hydrophobic additive may be contained together with the organic solvent and the vinyl monomer. By carrying out dispersion polymerization by containing a hydrophobic additive, an organic solvent mixture used in the production method of the present invention can be obtained as a polymerization mixture after polymerization.
[0027]
The organic solvent mixture used in the present invention can also be obtained by a method in which polymer particles obtained by polymerizing separately are mixed with an organic solvent together with a hydrophobic additive.
[0028]
In the production method of the present invention, water is added while removing the organic solvent from the organic solvent mixture. When an organic solvent that can be volatilized by heating is used, water may be added while heating. When an organic solvent that can be azeotroped with water is used as the organic solvent, the organic solvent can be volatilized at an azeotropic temperature lower than the boiling point of the organic solvent alone, which is preferable because the organic solvent can be removed more easily. .
[0029]
Heat steam (steam) may be blown into the mixture as described in Patent Document 2 (Japanese Patent Laid-Open No. 10-218935) in that heating and addition of water can be performed simultaneously. By blowing heated steam, water is added to the organic solvent mixture as water vapor, and at the same time, the organic solvent is heated and volatilized, or when an organic solvent that can be azeotroped with water is used. Azeotropically removed.
[0030]
Thus, by adding water while removing the organic solvent, more hydrophobic additive is impregnated in the polymer particles, and the target additive-containing polymer particles are produced. The organic solvent may be removed entirely (100% by mass), but if practically 90% by mass or more, preferably 95% by mass or more is removed, the hydrophobic additive is sufficiently added to the polymer particles. Can be impregnated.
[0031]
To remove the target additive-containing polymer particles from the mixture after adding water while removing the organic solvent, solid-liquid separation may be performed as usual. Specifically, the desired additive-containing polymer particles are obtained by solid-liquid separation by a filtration method such as natural filtration, centrifugal filtration, pressure filtration, or centrifugal sedimentation using a decanter, cyclone, or the like. Can do. Although moisture may remain in the obtained additive-containing polymer particles, such moisture may be removed by a method such as normal heat drying, vacuum drying, or air drying. Further, some moisture, for example, 5% by mass or more of moisture may be left with respect to the additive-containing resin particles, which is preferable in that it can be prevented from rising when the particle size of the polymer particles is small. .
[0032]
【The invention's effect】
According to the production method of the present invention, a polymer particle can be easily impregnated with a larger amount of an additive to produce an additive-containing polymer particle.
[0033]
【Example】
EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited by this Example.
[0034]
In addition, each physical property value in the following examples was measured by the following method.
(1) Weight average particle diameter Measurement was performed using a light diffraction / scattering particle diameter measuring instrument (“Microtrack FRA” manufactured by Leeds & Northrup Co., Ltd.)
(2) Heat resistance differential thermal thermogravimetric simultaneous measurement device (“TG / DTA6300” manufactured by Seiko Instruments Inc.) at an air flow rate of 200 mL / min (atmospheric pressure) at a rate of temperature increase from 50 ° C. to 20 ° C./min. The temperature was raised to 500 ° C., the temperature at which the mass was 95% of the mass before the temperature elevation was measured, and this temperature was defined as the heat resistant temperature. Higher temperature indicates that more phenolic antioxidant is impregnated into the polymer particles.
[0035]
Example 1
At room temperature, 92 parts by mass of methyl methacrylate and 8 parts by mass of allyl methacrylate were charged into a glass flask equipped with a stirring blade, 6 parts by mass of hydroxypropylcellulose was added with stirring, and then 693 parts by mass of methanol was added. Stirring was continued thereafter, and after hydroxypropylcellulose was completely dissolved in methanol, 203 parts by mass of ion-exchanged water was added with stirring. Then, it heated up to 55 degreeC, stirring under nitrogen stream. When the temperature reached 55 ° C., 2.9 parts by mass of t-butyl peroxyneodecanoate solution [“Trigonox 23C-70”, Kayaku Akzo Co., Ltd., purity 70% by mass] 5 parts by mass of methanol The solution previously dissolved in was added. Thereafter, the polymerization was continued with stirring at the same temperature for 4 hours. The polymerization mixture after polymerization was in the form of a slurry containing polymer particles having a weight average particle diameter of 2.4 μm.
[0036]
In the above, 130 parts by mass of the polymerization mixture was charged into another glass flask equipped with a stirring blade, and a phenolic antioxidant [1,3,5-tris (3,5-di-t-butyl-4-hydroxybenzyl) -1, 3,5-triazine-2,4,6 (1H, 3H, 5H) -trione] A solution prepared by previously dissolving 0.065 parts by mass in 10 parts by mass of methanol was added. Thereafter, ion-exchanged water was added so that the liquid level in the glass flask was kept constant while collecting the vaporized methanol and water mixture with a condenser while heating in an oil bath under stirring. In the meantime, the liquid temperature gradually increased and reached 94 ° C. when 6 hours had elapsed after the start of heating. At this point, heating was stopped and the mixture was cooled to obtain a slurry mixture. In the obtained mixture, the polymer particles were agglomerated.
[0037]
This mixture was filtered using filter paper (qualitative filter paper No. 5), and the filter residue was air-dried to obtain additive-containing polymer particles. The heat resistance temperature of the resulting additive-containing resin particles was 301 ° C.
[0038]
Comparative Example 1
Polymer particles were obtained in the same manner as in Example 1 except that the additive was not added. The heat resistance temperature of the obtained polymer particles was 244 ° C.
[0039]
Comparative Example 2
A polymer mixture obtained by operating in the same manner as in Example 1 was charged into a glass flask equipped with a stirring blade, and heated with an oil bath while stirring. Ion exchange water was added so that the liquid level in the flask was constant. During that time, the liquid temperature gradually increased and reached 94 ° C. when 6 hours had passed after the start of heating, and the content was a mixture of polymer particles and water, and was in the form of a slurry. At this point, heating was stopped. To this mixture, an additive [1,3,5-tris (3,5-di-t-butyl-4-hydroxybenzyl) -1,3,5-triazine-2,4,6 (1H, 3H, 5H) -Trione] A solution prepared by dissolving 0.065 parts by mass in 10 parts by mass of methanol was added and stirred at 90 ° C for 1 hour. Thereafter, water was removed by filtration in the same manner as in Example 1 to obtain additive-containing polymer particles. The heat resistance temperature of the obtained polymer particles was 270 ° C.

Claims (3)

The polymer particles are dispersed in an organic solvent, and water is added while removing the organic solvent from the organic solvent mixture in which the hydrophobic additive is dissolved, and the polymer particles are impregnated with the hydrophobic additive. A method for producing additive-containing polymer particles. The manufacturing method of Claim 1 which adds a hydrophobic additive to the polymerization mixture obtained by carrying out dispersion polymerization of the vinyl monomer in the organic solvent, and obtains an organic solvent mixture. The production method according to claim 1, wherein the hydrophobic additive is a phenolic antioxidant.