JP2005097370A - Functional polyamide fine particle and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of a functional polyamide fine particle capable of easily controlling its particle shape and particle size distribution, and the functional polyamide fine particle superior in monodispersibility. <P>SOLUTION: This manufacturing method of the functional polyamide particle relates to a synthesis method of a polyamide using an acid chloride and a diamine compound. The method comprises (a) a first step wherein at least one of the acid chloride and the diamine compound has a functional group, and preparing a first solution containing the acid chloride and a second solution containing the diamine compound, respectively, and (b) a second step mixing the first and second solutions under existence of a solvent soluble in both the first and second solvents, and depositing the polyamide fine particle from the mixed solution. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to functional polyamide fine particles and a method for producing the same.

  Polyamide is a material excellent in heat resistance, chemical resistance, mechanical properties, and the like, and is widely used as an alternative material for metals or ceramics in addition to applications such as electronic / electrical parts, automobiles, and clothing.

  As a method for producing polyamide fine particles, a) a method in which prepolymerized nylon 6, 66, 12 or the like (polymer) is dissolved in formic acid or the like and then dropped into a poor solvent such as distilled water, methanol or acetone to the cloud point. B) A method in which the temperature of the polymer-polymerized solution is raised to completely dissolve nylon, and fine particles (about 2 to 10 μm) are precipitated while strictly controlling the temperature.

  However, these methods require two steps, a process of polymerizing a polymer and a process of preparing fine particles from the polymer, and particularly in the latter process, it is necessary to strictly control the preparation conditions such as temperature. There is a drawback that the process is complicated. Further, in these methods, it is necessary to dissolve nylon (polymer), but nylon has high chemical resistance, is soluble only in a small part of organic solvents such as formic acid and sulfuric acid, and is difficult to handle. Furthermore, depending on the above method, there is a problem that only polyamide particles having a relatively large particle size (about 2 to 10 μm) can be obtained.

  As another method for producing polyamide fine particles, there has been proposed a method in which polyamide is freeze-dried and then pulverized to form fine particles (tens to hundreds of μm).

  However, it is very difficult to control the particle shape by such a method. Further, the polyamide fine particles obtained by the above method have a problem that the particle size is large and the distribution range is wide.

  Moreover, the above method does not mention a method for imparting functionality to the polyamide fine particles. If various functions can be imparted to the polyamide fine particles whose particle shape, particle size distribution and the like are controlled, further expansion of applications is expected.

  The main object of the present invention is to provide a method for producing functional polyamide fine particles capable of easily controlling the particle shape, particle size distribution and the like. Another object of the present invention is to provide functional polyamide fine particles having excellent monodispersibility.

  As a result of intensive studies in view of the problems of the prior art, the present inventor has found that the above object can be achieved by a production method having a specific process, and has completed the present invention.

  That is, the present invention relates to the following functional polyamide fine particles and a method for producing the same.

1. In a method of synthesizing a polyamide from an acid chloride and a diamine compound,
(A) a first step in which at least one of an acid chloride and a diamine compound has a functional group and a first solution containing the acid chloride and a second solution containing the diamine compound are prepared; and b) a second step of mixing the first solution and the second solution in the presence of a solvent that is soluble in both the solvent of the first solution and the second solution and precipitating polyamide fine particles from the mixed solution;
A process for producing functional polyamide fine particles, comprising:

  2. Item 2. The method according to Item 1, wherein the second solution further contains a diamine compound having no functional group.

  3. Item 3. The method according to Item 2, wherein the second solution is obtained by mixing a solution containing a diamine compound having a functional group and a solution containing a diamine compound not having a functional group.

  4). Item 4. The production method according to any one of Items 1 to 3, wherein the solvent that is soluble in both the solvent of the first solution and the second solution is at least one of water and a solvent having a hydroxyl group.

  5). Item 5. The production method according to Item 4, wherein the solvent having a hydroxyl group contains at least one kind of alcohol having 1 to 10 carbon atoms.

  6). Item 5. The method according to any one of Items 1 to 4, wherein the second step is performed under stirring by ultrasonic waves.

  7). Item 7. The method according to any one of Items 1 to 6, wherein the solvent in the first solution contains at least one of acetone and dioxane.

  8). Item 7. The method according to any one of Items 1 to 6, wherein the solvent in the second solution contains at least one of acetone and dioxane.

  9. Functional polyamide fine particles obtainable by the method according to any one of Items 1 to 8.

  10. 9. A functional polyamide fine particle obtained by the method according to any one of Items 1 to 8 and having an average particle size of 0.01 to 5 μm.

  11. 11. The functional polyamide fine particles according to item 9 or 10, which exhibit a glass transition temperature.

  12 11. The functional polyamide fine particles according to item 9 or 10, which do not exhibit a glass transition temperature.

  13. A method for confirming the presence of a functional group present on the surface of a polyamide fine particle by infrared spectroscopy and / or energy dispersive X-ray spectroscopy, which can react with the functional group prior to the analysis method A method for analyzing the surface of polyamide fine particles, wherein the surface of the polyamide fine particles is pretreated with a silane coupling agent.

  According to the production method of the present invention, functional polyamide fine particles having a fine and uniform particle diameter can be obtained relatively easily without requiring strict temperature control or the like as in the prior art. In addition, the method of the present invention is suitable as an industrial method because it is not necessary to use a difficult solvent such as formic acid or sulfuric acid as compared with the conventional method. Furthermore, in the method of the present invention, it is relatively easy to control the desired particle size, particle shape, particle size distribution, etc. by appropriately changing the conditions.

  The functional polyamide fine particles of the present invention thus obtained have a functional group on the particle surface in particular, so that adhesives, paints, dispersants in printing inks, medical carriers, magnetic recording It can be widely used for media, cosmetic base materials, plastic modifiers, chromatographic carriers, interlayer insulating film materials, and the like.

  In addition, the functional polyamide fine particles of the present invention have high heat resistance, and particularly when an aromatic compound is used as the acid chloride and / or diamine compound, extremely high heat-resistant particles that do not exhibit a glass transition temperature can be obtained. Therefore, substitution of polyimide particles is also possible.

1. TECHNICAL FIELD The present invention relates to a polyamide fine particle and a method for producing the same. In this specification, “polyamide” includes “polyamideimide”.

  Hereafter, the manufacturing method of this invention is demonstrated in detail for every process.

(1) First Step In the present invention, polyamide fine particles are prepared using an acid chloride and a diamine compound as raw materials. First, as a first step, a first solution containing an acid chloride compound and a second solution containing a diamine compound are prepared. In this case, one having at least one of an acid chloride and a diamine compound having a functional group is used.

The functional group is not particularly limited as long as a desired function can be imparted on the surface of the obtained fine particles. For example, hydroxyl group (—OH), carboxyl group (—COOH), amino group (—NH ₂ ), alkenes (—CH═CH—), alkynes (—C≡C—), vinyl ethers (—CH═CH) -O-), amido (-CONH _2), a nitrile group (-C≡N), isocyanate group (-N = C = O), nitro group (-NO _2), sulfone group (-SO ₃ H), thiol group (-SH), other functional groups such as crown ether group, -CF ₃ group, -CCl ₃ group, can be exemplified -CBr _3, and the like. In addition, in the diamine compound and acid chloride used as raw materials, each has a group —NH ₂ and a group —COCl, but when these groups are present on the surface of the finally obtained fine particles. Are included in the functional group of the present invention.

  In the present invention, one or more compounds having one or more of these functional groups can be used. Further, when one compound has two or more functional groups, these functional groups may be the same or different from each other. In the present invention, these functional groups can be appropriately imparted to the surface of the fine particles depending on the desired physical properties of the obtained polyamide fine particles, the use of the final product, and the like.

  After using these raw materials, a first solution containing an acid chloride and a second solution containing a diamine compound are prepared as the first step. That is, in the present invention, it is essential to prepare the acid chloride and the diamine compound as separate solutions.

(A) First solution The acid chloride used in the first solution is not particularly limited, and for example, the same one as used in conventional polyamide synthesis can be used.

  Examples of the acid chloride include trichloride, tetrachloride and the like in addition to dichloride, but dichloride can be preferably used in general. For example, aliphatic dicarboxylic acid dichlorides such as oxalic acid dichloride, malonic acid dichloride, succinic acid dichloride, fumaric acid dichloride, glutaric acid dichloride, adipic acid dichloride, muconic acid dichloride, sebacic acid dichloride, nonanoic acid dichloride, undecanoic acid dichloride; 1 , 2-cyclopropanedicarboxylic acid dichloride, 1,3-cyclobutanedicarboxylic acid dichloride, 1,3-cyclopentanedicarboxylic acid dichloride, 1,3-cyclohexanedicarboxylic acid dichloride, 1,4-cyclohexanedicarboxylic acid dichloride, etc. Dicarboxylic acid dichloride; phthalic acid dichloride, isophthalic acid dichloride, terephthalic acid dichloride, 1,4-naphthalenedicarboxylic acid dichloride, 1,5 -(9-oxofluorene) dicarboxylic acid dichloride, 1,4-anthracene dicarboxylic acid dichloride, 1,4-anthraquinone dicarboxylic acid dichloride, 2,5-biphenyldicarboxylic acid dichloride, 1,5-biphenylenedicarboxylic acid dichloride, 4,4 '-Biphenyldicarbonyl chloride, 4,4'-methylene dibenzoic acid dichloride, 4,4'-isopropylidene dibenzoic acid dichloride, 4,4'-bibenzyldicarboxylic acid dichloride, 4,4'-stilbene dicarboxylic acid dichloride 4,4′-transidicarboxylic acid dichloride, 4,4′-carbonyldibenzoic acid dichloride, 4,4′-oxydibenzoic acid dichloride, 4,4′-sulfonyldibenzoic acid dichloride, 4,4′-dithio Dichlori dibenzoate , P- phenylene diacetic acid dichloride, and aromatic dicarboxylic acid dichloride such as 3,3'-p-phenylene acid dichloride. These acid chlorides can be used alone or in combination of two or more.

  In the case of using an acid chloride having a functional group, the acid chloride having the functional group listed above can be used. For example, 4,4 ′-(2,2-hexafluoroisopropylidene) diphthalic acid dichloride), 4-nitrophthalic acid dichloride, 3-nitrophthalic acid dichloride, 4-methylphthalic acid dichloride, tetrachlorophthalic acid dichloride, and the like. it can. Moreover, what has the said functional group in the dichloride of an acid chloride which can be used for the polyamideimide of a postscript, a trichloride, etc. can be used as an acid chloride (raw material) of this invention.

  In the present invention, an acid chloride having a functional group and an acid chloride having no functional group can be used in combination. Thereby, the characteristic of the polyamide fine particle obtained can be controlled arbitrarily. The ratio of both in this case can be appropriately set according to the type of functional group, the desired amount of functional group, and the like.

  The acid chloride can be appropriately selected according to the desired characteristics of the obtained polyamide fine particles. For example, when an aromatic dicarboxylic acid dichloride (especially at least one of terephthalic acid dichloride, 4,4′-biphenyldicarbonyl chloride and isophthalic acid dichloride) is used as the acid chloride, the heat resistance and monodispersity of the resulting polyamide fine particles can be improved. Can be improved.

  The polyamide of the present invention includes polyamideimide. Therefore, the acid chloride used in the conventional polyamideimide synthesis can be used. For example, trimellitic acid chloride, pyromellitic acid chloride, oxydiphthalic acid chloride, biphenyl-3,4,3 ′, 4′-tetracarboxylic acid chloride, benzophenone-3,4,3 ′, 4′-tetracarboxylic acid chloride, Diethylpyromellitate diacyl chloride, diphenylsulfone-3,4,3 ′, 4′-tetracarboxylic acid chloride, 4,4 ′-(2,2-hexafluoroisopropylidene) phthalic acid chloride, m (p) -phenyl -3,4,3 ', 4'-tetracarboxylic acid chloride, cyclobutane-1,2,3,4-tetracarboxylic acid chloride, 1-carboxymethyl-2,3-5 cyclopentanetricarboxylic acid chloride, etc. Chloride can be used. These acid chlorides may be any of dichloride, trichloride or tetrachloride.

  In addition, when producing polyamideimide, in addition to acid chloride, as carboxylic acid anhydride, trimellitic dianhydride, pyromellitic dianhydride, oxydiphthalic dianhydride, biphenyl-3,4, 3 ′, 4′-tetracarboxylic dianhydride, benzophenone-3,4,3 ′, 4′-tetracarboxylic dianhydride, diethyl pyromellitic diacyl dianhydride, diphenylsulfone-3,4,3 ', 4'-tetracarboxylic dianhydride, 4,4'-(2,2-hexafluoroisopropylidene) diphthalic dianhydride, m (p) -phenyl-3,4,3 ', 4'- It is possible to use tetracarboxylic dianhydride, cyclobutane-1,2,3,4-tetracarboxylic dianhydride, 1-carboxymethyl-2,3-5 cyclopentanetricarboxylic dianhydride Kill.

  The solvent used in the first solution is not particularly limited as long as the acid chloride is substantially dissolved and the produced polyamide is not dissolved. Examples thereof include solvents soluble in a solvent having water or a hydroxyl group, such as acetone, dioxane, acetylacetone, methyl ethyl ketone, and methyl acetate, and a solvent containing at least one of these can be used. Among these, in the first solution, a solvent containing at least one of acetone and dioxane is preferable. Depending on the type of acid chloride used, it may not be immediately dissolved in a solvent such as acetone. In such a case, it may be dissolved in water or a solvent having a hydroxyl group in advance and then dissolved in acetone or the like. .

  The concentration of acid chloride in the first solution may be appropriately set according to the type of acid chloride used, the concentration of the second solution, etc., but is usually about 0.005 to 1 mol / liter, preferably 0.01 to About 0.5 mol / liter. It is preferable that the acid chloride concentration in the first solution be within such a range because aggregation and coalescence between particles can be suppressed and a monodispersed one can be easily obtained.

(B) Second solution The diamine compound used in the second solution is not particularly limited, and examples thereof include those used in known polyamide synthesis. For example, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenyl ether, 4,4′-bis (4-aminophenoxy) biphenyl, 4,4′-bis (3-aminophenoxy) biphenyl, 1,4 ′ -Bis (4-aminophenoxy) benzene, 1,3'-bis (4-aminophenoxy) benzene, 1,3-bis (3-aminophenoxy) benzene, o-phenylenediamine, m-phenylenediamine, p-phenylene Diamine, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl sulfone, 3,4-diaminodiphenyl sulfone, 3,3'-diaminodiphenyl sulfone, 4,4'-methylene-bis (2-chloroaniline) 3,3′-dimethyl-4,4′-diaminobiphenyl, 4,4′-diaminodiphenylsulfur 2,6′-diaminotoluene, 2,4-diaminochlorobenzene, 1,2-diaminoanthraquinone, 1,4-diaminoanthraquinone, 3,3′-diaminobenzophenone, 3,4-diaminobenzophenone, 4,4 '-Diaminobenzophenone, 4,4'-diaminobibenzyl, R (+)-2,2'-diamino-1,1'-binaphthalene, S (+)-2,2'-diamino-1,1'- 1, n-bis (4- (4-aminophenoxy) alkane, 1,4-bis (4-aminophenoxy) alkane, 1,4-bis (4-aminophenoxy) alkane, 1,5-bis (4-aminophenoxy) alkane, etc. Aminophenoxy) alkane (n is 3 to 10), 1,2-bis [2- (4-aminophenoxy) ethoxy] ethane, 9,9-bis (4-aminophenyl) fluorene Aromatic diamines such as 4,4′-diaminobenzanilide; 1,2-diaminomethane, 1,4-diaminobutane, tetramethylenediamine, 1,5-diaminopentane, 1,6-diaminohexane, 1,8- Aliphatic diamines such as diaminooctane, 1,10-diaminododecane, 1,11-diaminoundecane; 1,4-diaminocyclohexane, 1,2-diaminocyclohexane, bis (4-aminocyclohexyl) methane, 4,4′- In addition to alicyclic diamines such as diaminodicyclohexylmethane, 3,4-diaminopyridine, 1,4-diamino-2-butanone, and the like can be used. These can use 1 type (s) or 2 or more types. In particular, it is preferable to use 4,4′-diaminodiphenyl ether, 4,4′-diaminodiphenylmethane, etc., because the heat resistance and monodispersibility are improved.

  In the present invention, in addition to the diamine compound, other amine compounds (monoamine compounds, polyamine compounds, etc.) can also be used. By these, the characteristic of the polyamide obtained can be changed.

  When using the diamine compound which has a functional group, it is the said diamine compound, Comprising: What has the functional group quoted above can be used. For example, 1,3-diamino-2-propyl alcohol, 2,2-bis (4-aminophenyl) hexafluoropropane, 3,5-diaminobenzoic acid, 3,4-diaminobenzoic acid, 2,4,6- Triaminopyrimidine, 4,4′-diamino-3,3′-dihydroxybiphenyl, 2,4-diamino-6-hydroxypyrimidine and the like can be used.

  In this invention, the diamine compound which has a functional group, and the diamine compound which does not have a functional group can also be used together. As a result, the characteristics and the like of the obtained polyamide fine particles can be changed. The ratio of both in this case can be appropriately set according to the type of functional group, the desired amount of functional group, and the like.

  The solvent used in the second solution is not particularly limited as long as it substantially dissolves the diamine compound and does not dissolve the produced polyamide. Examples thereof include solvents that are soluble in water or a solvent having a hydroxyl group, such as acetone, methyl ethyl ketone (MEK), dioxane, acetylacetone, and methyl acetate. A solvent containing at least one of these can be used. Among these, in the second solution, a solvent containing at least one of acetone and dioxane is preferable. Depending on the type of diamine compound used, it may not be dissolved immediately in a solvent such as acetone. In such a case, it may be dissolved in water or a solvent having a hydroxyl group in advance and then dissolved in acetone or the like. .

  Moreover, when using together the diamine compound which does not have a functional group, the solution (henceforth "the solution A") of the diamine compound which has a functional group, and the solution (henceforth a diamine compound which does not have a functional group) The second solution can also be suitably prepared by separately preparing “solution B”) in advance and then mixing them together. In this case, the solvent of the solution of the diamine compound having a functional group and the solvent of the solution of the diamine compound having no functional group may be the same, or may be different as long as they are compatible with each other. .

  When preparing the second solution using the solution A and the solution B, the mixing ratio of the solution A and the solution B should be appropriately set according to the type of the diamine compound used, the type of the functional group, the desired characteristics, and the like. It ’s fine.

  The solvent of the second solution may be the same as the solvent of the first solution, or may be different as long as they are compatible with each other.

  The concentration of the diamine compound in the second solution may be appropriately set according to the type of diamine compound to be used, the concentration of the first solution, etc., but is usually about 0.005 to 1 mol / liter, preferably 0.01 to 0.5 mol / liter. It is preferable that the concentration of the diamine compound in the second solution be within this range because aggregation and coalescence between particles can be suppressed and a monodispersed one can be easily obtained. The solution A and the solution B may be set to the same concentration.

(2) Second step In the second step, the first solution and the second solution are mixed, and the presence of a solvent that is soluble in any of the solvents of the two solutions (hereinafter sometimes referred to as “soluble solvent”). Reaction is performed below to precipitate polyamide fine particles from the mixed solution. The mixing ratio of the first solution and the second solution can be appropriately changed depending on the acid chloride, the type of the diamine compound, the concentration of each solution, etc., but usually the acid chloride: diamine compound = 1: about 0.5 to 1.5. (Molar ratio), preferably in a ratio of 1: 0.9 to 1.1.

  The soluble solvent is not particularly limited as long as it is soluble in both the first solution and the second solution, but a solvent having water and a hydroxyl group is preferable. Specifically, water; alcohols having about 1 to 10 carbon atoms, for example, monohydric alcohols having about 1 to 10 carbon atoms such as methanol, ethanol, and propanol, ethylene glycol, 1,2-propanediol, 1,3 -C2-C5 dihydric alcohols, such as propanediol and 1,5-pentanediol, C3-C6 trivalent alcohols, such as 1,2,3-propanetriol, etc. are mentioned. Among these, as the soluble solvent, it is preferable to use water from the viewpoint of monodispersibility and particle size. In addition, when using the solvent which has water and a hydroxyl group as a soluble solvent, the solvent of a 1st solution and a 2nd solution is naturally a solvent soluble in these. For example, when water is used, it is preferable to use acetone and dioxane having high compatibility with water as the solvent for the first solution and the second solution.

  The soluble solvent may be added to the first solution and / or the second solution immediately before mixing the first solution and the second solution, but is preferably added to the second solution.

  The addition amount of the soluble solvent may be appropriately set according to the type of acid chloride and diamine compound to be used, the concentration of the first solution and the second solution, the desired (average) particle size of the obtained polyamide fine particles, etc. Is about 1 to 200 ml, preferably about 1 to 100 ml, with respect to 100 ml of the first solution or the second solution.

  By adding a soluble solvent, it is possible to obtain spherical fine particles with high monodispersibility.

  In the second step, it is particularly preferable to deposit the polyamide while stirring. Stirring can be carried out by a known stirring method (stirring device). In the present invention, it is particularly preferable to stir by ultrasonic waves. By stirring with ultrasonic waves, it is possible to reduce the average particle size by about 50% as compared with a normal stirring method. Moreover, particles with a more uniform particle size can be obtained by ultrasonic stirring. For stirring by ultrasonic waves, a known ultrasonic device (for example, an ultrasonic cleaner) and operating conditions can be employed as they are. The frequency of the ultrasonic wave may be appropriately set according to a desired (average) particle size and the like, and is usually about 28 to 1000 kHz, preferably about 28 to 100 kHz, and more preferably about 28 to 45 kHz.

  The temperature in the second step is not particularly limited, and is usually about 0 to 100 ° C., preferably about 0 to 40 ° C. When the mixed solution is cooled and the reaction rate is reduced, fine particles having a more spherical shape than the particle diameter are obtained. Therefore, the temperature of the second step is about room temperature (25 ° C.) or less, particularly about 0 to 15 ° C. Further preferred. The stirring may be performed until the precipitation of the polyamide is substantially completed, and the stirring time is usually about 30 seconds to 30 minutes, but may be out of this range.

  The polyamide fine particles precipitated in the second step may be recovered by solid-liquid separation according to a known method such as a centrifugal separation method.

When trying to obtain polyamideimide as polyamide, use the ones used in the synthesis of polyamideimide such as trimellitic acid chloride as acid chloride and trimellitic anhydride as carboxylic anhydride, and fine particles obtained in the second step What is necessary is just to imidize by condensing the carboxyl group and amide group which exist. The method for imidization is not particularly limited. In the present invention, in particular, (i) it is dispersed in an organic solvent and heated (usually 130 ° C. or higher, preferably heated at a temperature of about 130 to 250 ° C.) for imidization. It is desirable to adopt a method (thermal ring closure) to perform (i) a method of imidization by a chemical reaction in an organic solvent (chemical ring closure).
2. Functional polyamide fine particles When the functional polyamide fine particles (powder) of the present invention are produced as a sphere, the average particle size is generally about 0.01 to 5 μm (particularly about 0.03 to 3 μm, preferably 0.1). To 2 μm, more preferably 0.2 to 1.8 μm, more preferably 0.2 μm to less than 1 μm, and most preferably 0.2 to 0.9 μm.

  In addition, according to the method of the present invention, the polyamide fine particles produced as spheres are obtained as porous spherical particles close to monodisperse, with a standard deviation of about 0.02 to 0.25 (preferably 0.02 to 0). .18) and a coefficient of variation of about 3 to 25% (preferably about 3 to 15%). On the other hand, the polyamide fine particles produced in a flat shape are also obtained as porous particles close to monodisperse, with a standard deviation of about 0.02 to 0.25 (preferably about 0.02 to 0.18) and a coefficient of variation of 3. It is monodispersed in a range of about -25% (preferably about 3-15%).

Moreover, fine polyamide particles according to the present invention a method (powder) is generally the extent that the specific surface area exceeds 20 m ² / g (e.g. 30~300m ² / g approximately, in particular 40 to 300 m ² / g approximately, and even more 50 to 300 m ² / g, preferably about 60～300M ² / g approximately, more preferably 70～300M ² / g, more preferably about 80 m ² / g, greater 300 meters ² / g or less, and most preferably 90～200M ² / g Degree).

  Furthermore, the polyamide fine particles by the method of the present invention include both those showing a glass transition temperature (Tg) and those showing no glass transition temperature (Tg). In general, polyamide fine particles exhibiting a glass transition temperature (usually about 250 to 260 ° C.) are particles having less irregularities on the particle surface and closer to a spherical shape than polyamide fine particles not exhibiting the same.

  The presence or absence of the glass transition point of the polyamide fine particles can be appropriately controlled by changing the production conditions (particularly, the type of acid chloride and / or diamine compound used).

The present invention also includes polyamideimide fine particles having characteristics such as the average particle size, standard deviation, coefficient of variation, specific surface area and the like in the above-described ranges.
3. Method for Analyzing Functional Polyamide Fine Particles The present invention also includes a method for confirming the presence of a functional group (functional group) present on the surface of functional polyamide fine particles. Specifically, it is a method for confirming the presence of a functional group present on the surface of a polyamide fine particle by an infrared spectroscopic analysis method and / or an energy dispersive X-ray spectroscopic analysis method, prior to the analysis method. The present invention relates to a method for analyzing the surface of a polyamide fine particle, characterized in that the surface of the polyamide fine particle is previously treated with a silane coupling agent capable of reacting with the functional group.

  The silane coupling agent can react with a functional group and can be appropriately selected from known or commercially available silane coupling agents. For example, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, N-2 (aminoethyl) 3-aminopropylmethyldimethoxysilane, N- 2 (aminoethyl) 3-aminopropyltrimethoxysilane, N-2 (aminoethyl) 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-isocyanatopropyltriethoxy Examples thereof include silane, 3-mercaptopropylmethyldimethoxysilane, and 3-mercaptopropyltrimethoxysilane.

  The treatment method using a silane coupling agent is not particularly limited as long as it is a method capable of applying a silane coupling agent to the surface of the polyamide fine particles. For example, polyamide fine particles may be dispersed or immersed in a silane coupling agent or a solution thereof, or mixed or kneaded. In these cases, heating may be performed as necessary. The concentration of the silane coupling agent, the treatment amount of the polyamide fine particles, and the like can be appropriately determined according to the type of functional group, the type of silane coupling agent, and the like. After the above treatment, if necessary, solid-liquid separation may be performed by a known method such as centrifugation to collect polyamide fine particles, and if necessary, neutralization may be performed by washing with a solvent such as ethanol or acetone.

  As an analysis method of the present invention, an analysis method using infrared spectroscopy and / or energy dispersive X-ray spectroscopy (EDX) is used. These operation methods may follow a known operation method. Moreover, it can implement using a well-known or commercially available apparatus.

  In the analysis method of the present invention, for example, as shown in FIG. 10 (a), when functional polyamide fine particles obtained using 3,5-diaminobenzoic acid as a diamine compound having a functional group are used, a silane coupling agent is used. When 3-glycidoxypropyltriethoxysilane is added, the silane coupling agent reacts with and binds to the carboxyl group. On the other hand, as shown in FIG. 10 (b), when there is no carboxyl group, the above reaction does not occur. Thus, the functional group on the surface of the polyamide fine particle is confirmed by infrared spectroscopy and / or energy dispersive X-ray spectroscopy (EDX) due to the presence of the group in which the silane coupling agent is bonded to the functional group. It becomes possible. The procedure for confirmation is as follows: 1) Polyamide fine particles having no functional group (control), 2) Polyamide fine particles having a functional group (analysis target), both of which are treated with a silane coupling agent. Prepare the sample before processing and the sample after processing, and analyze them by the above analysis method. Depending on the presence or absence of the difference (difference spectrum when using infrared analysis spectroscopy, peak difference when using EDX) The presence or absence of a functional group can be confirmed.

In the analysis method of the present invention, any functional group can be qualitatively analyzed as long as it reacts with a silane coupling agent. As described above, examples of the functional group include a hydroxyl group (—OH), a carboxyl group (—COOH), an amino group (—NH ₂ ), an alkene (—CH═CH—), and an alkyne (—C≡C). -), vinyl ethers (-CH = CH-O-), amido (-CONH _2), a nitrile group (-C≡N), isocyanate group (-N = C = O), nitro group (-NO ₂₎ , sulfone group (-SO ₃ H), thiol group (-SH), other functional groups such as crown ether group, -CF ₃ group, -CCl ₃ group, can be exemplified -CBr _3, and the like.

  Examples are given below to further clarify the features of the present invention. However, the scope of the present invention is not limited to the examples.

  In the examples, ultrasonic stirring was performed using an ultrasonic cleaner “ULTRASONIC CLEANER VS-100 III SUNPAR”.

  Each physical property in the present invention was measured as follows.

(1) Glass transition temperature, etc. The glass transition temperature (Tg) was determined by differential scanning calorimetry (DSC). The measurement conditions were a heating rate of 10 ° C./min and nitrogen of 50 ml / min. The thermal decomposition temperature (Td) was determined by thermogravimetric differential thermal analysis (TGDTA). The measurement conditions were a temperature increase rate of 10 ° C./min and nitrogen of 200 ml / min.

(2) Average particle size, etc. The average particle size is observed with a scanning electron microscope (SEM), 100 arbitrary fine particles are selected from the SEM photograph, and the average particle size of these fine particles is determined according to the following formula (1). Asked.

Further, based on the value of the average particle diameter, the standard deviation (S) was obtained according to the following formulas (2) and (3), and the coefficient of variation (C) was also obtained according to the formula (4). The smaller the variation coefficient, the smaller the particle size variation.

(3) Specific surface area The specific surface area was determined by the BET method using nitrogen as an inert gas.

Example 1
Preparation of polyamide fine particles having amino groups on the particle surface First, as a first solution, a 50 ml solution in which 0.0005 mol of terephthalic acid dichloride is dissolved in acetone (referred to as a terephthalic acid dichloride / acetone = 0.0005 mol / 50 ml solution; the same applies hereinafter). 4,4′-diaminodiphenyl ether / acetone = 0.004 mol / 50 ml solution as solution B, and 2,4,6-triaminopyrimidine / ion exchange water = 0.0001 mol / 25 ml solution as solution A, respectively, Cooled to 4 ° C.

Thereafter, the A solution was added to the B solution and stirred. Next, the first solution was further mixed in an ice bath, and the mixture was stirred for 20 minutes with an ultrasonic wave having a frequency of 28 kHz for reaction to precipitate polyamide. The obtained polyamide was observed with a scanning electron microscope (SEM), and it was confirmed that the polyamide was composed of spherical particles close to monodisperse. The image is shown in FIGS. 1 (a) and 1 (b). The average particle size of the polyamide fine particles was 0.791 μm, standard deviation 0.0721, coefficient of variation 7.701%, specific surface area 97.31 m ² / g. The thermal decomposition temperature (Td (5 wt% loss)) was 408 ° C., and the glass transition temperature (Tg) was not shown.

Example 2
Preparation of polyamide fine particles having amino groups on the particle surface First, 50 ml solution in which 0.0005 mol of isophthalic acid dichloride was dissolved in dioxane as the first solution, and 4,4′-diaminodiphenyl ether / dioxane = 0.000 4 mol / 50 ml as the B solution. 2,4,6-triaminopyrimidine / ion exchange water = 0.0001 mol / 25 ml solutions were prepared as solution and solution A, respectively, and cooled to about 4 ° C.

Thereafter, the solution A was added to the solution B and stirred. Next, the first solution was further mixed in an ice bath, and the mixture was stirred for 20 minutes with an ultrasonic wave having a frequency of 28 kHz for reaction to precipitate polyamide. The obtained polyamide was observed with a scanning electron microscope (SEM), and it was confirmed that the polyamide was composed of spherical particles that were close to monodisperse and had irregularities on the surface. The image is shown in FIGS. 2 (a) and 2 (b). The average particle size of the polyamide fine particles was 0.762 μm, standard deviation 0.121, coefficient of variation 12.5%, specific surface area 70.90 m ² / g. The thermal decomposition temperature (Td (5 wt% loss)) was 392 ° C., and the glass transition temperature (Tg) was not shown.

Example 3
Preparation of polyamide fine particles having carboxyl groups on the particle surface First, 50 ml solution of 0.0005 mol of terephthalic acid dichloride dissolved in acetone as the first solution, and 4,4′-diaminodiphenylmethane / acetone = 0.004 mol / 50 ml as the B solution. As solutions and A solutions, 3,5-diaminobenzoic acid / ion exchange water = 0.0001 mol / 25 ml solutions were prepared, respectively, and cooled to about 4 ° C.

Thereafter, the solution A was added to the solution B and stirred. Next, the first solution was further mixed in an ice bath, and the mixture was stirred for 20 minutes with an ultrasonic wave having a frequency of 28 kHz for reaction to precipitate polyamide. The obtained polyamide was observed with a scanning electron microscope (SEM), and it was confirmed that the polyamide was composed of spherical particles that were close to monodisperse and had irregularities on the surface. The image is shown in FIGS. 3 (a) and 3 (b). The average particle diameter of the polyamide fine particles was 1.238 μm, standard deviation 0.0989, coefficient of variation 9.031%, specific surface area 45.72 m ² / g. The thermal decomposition temperature (Td (5 wt% loss)) was 411 ° C., and the glass transition temperature (Tg) was not shown.

Example 4
Preparation of polyamide fine particles having carboxyl groups on the particle surface First, 50 ml solution of 0.0005 mol of terephthalic acid dichloride dissolved in acetone as the first solution and 3,5-diaminobenzoic acid / (acetone + ion exchange water as the second solution) ) = 0.0001 mol / (50 + 5 ml) solutions were prepared and cooled to about 4 ° C.

Next, both solutions were mixed in an ice bath, stirred for 20 minutes with an ultrasonic wave having a frequency of 28 kHz, and reacted to precipitate polyamide. The obtained polyamide was observed with a scanning electron microscope (SEM), and it was confirmed that the polyamide was composed of spherical particles that were close to monodisperse and had irregularities on the surface. The image is shown in FIGS. 4 (a) and 4 (b). The average particle size of the polyamide fine particles was 0.988 μm, standard deviation 0.0915, coefficient of variation 9.512%, specific surface area 73.21 m ² / g. The thermal decomposition temperature (Td (5 wt% loss)) was 382 ° C., and the glass transition temperature (Tg) was not shown.

Example 5
Preparation of polyamide fine particles having carboxyl groups on the particle surface First, 50 ml solution of 0.0005 mol of terephthalic acid dichloride dissolved in acetone as the first solution and 3,5-diaminobenzoic acid / (dioxane + ion exchange water as the second solution) ) = 0.0001 mol / (50 + 2 ml) solutions were prepared and cooled to about 4 ° C.

Next, both solutions were mixed in an ice bath, stirred for 20 minutes with an ultrasonic wave having a frequency of 28 kHz, and reacted to precipitate polyamide. The obtained polyamide was observed with a scanning electron microscope (SEM), and it was confirmed that the polyamide was composed of spherical particles having a monodisperse and flat surface. The image is shown in FIGS. 5 (a) and 5 (b). The average particle size of the polyamide fine particles was 0.279 μm, standard deviation 0.0512, coefficient of variation 9.932%, specific surface area 22.78 m ² / g. The thermal decomposition temperature (Td (5 wt% loss)) was 366 ° C., and the glass transition temperature (Tg) was not shown.

Example 6
Preparation of polyamide fine particles having carboxyl groups on the particle surface First, 50 ml solution of 0.0005 mol of terephthalic acid dichloride dissolved in acetone as the first solution, and 4,4′-diaminodiphenylmethane / acetone = 0.004 mol / 50 ml as the B solution. As solutions and A solutions, 3,4-diaminobenzoic acid / ion-exchanged water = 0.0001 mol / 25 ml solutions were prepared and cooled to about 4 ° C.

Thereafter, the solution A was added to the solution B and stirred. Next, the first solution was further mixed in an ice bath, and the mixture was stirred for 20 minutes with an ultrasonic wave having a frequency of 28 kHz for reaction to precipitate polyamide. The obtained polyamide was observed with a scanning electron microscope (SEMM), and it was confirmed that the polyamide was composed of flat particles close to monodispersion. The image is shown in FIGS. 6 (a) and 6 (b). The average particle size (major axis direction) of the polyamide fine particles was 1.322 μm, standard deviation 0.0893, coefficient of variation 9.202%, specific surface area 41.35 m ² / g. The thermal decomposition temperature (Td (5 wt% loss)) was 412 ° C., and the glass transition temperature (Tg) was not shown.

Example 7
Preparation of polyamide fine particles having carboxyl groups on the particle surface First, 50 ml solution of 0.0005 mol of terephthalic acid dichloride dissolved in acetone as the first solution, and 4,4′-diaminodiphenylmethane / acetone = 0.003 mol / 50 ml as the B solution. As solutions and A solutions, 3,4-diaminobenzoic acid / ion-exchanged water = 0.0002 mol / 25 ml solutions were prepared and cooled to about 4 ° C.

Thereafter, the solution A was added to the solution B and stirred. Next, the first solution was further mixed in an ice bath, stirred for 20 minutes with ultrasonic waves having a frequency of 28 kHz, and reacted to precipitate polyamide. The obtained polyamide was observed with a scanning electron microscope (SEM), and it was confirmed that the polyamide was composed of particles that were close to monodisperse and had irregularities on the surface. The image is shown in FIGS. 7 (a) and 7 (b). The average particle diameter (major axis direction) of the polyamide fine particles was 0.924 μm, standard deviation 0.121, coefficient of variation 12.306%, specific surface area 52.27 m ² / g. The thermal decomposition temperature (Td (5 wt% loss)) was 333 ° C., and the glass transition temperature (Tg) was not shown.

Example 8
Preparation of polyamide fine particles having hydroxyl groups on the particle surface First, 50 ml solution in which 0.0005 mol of terephthalic acid dichloride was dissolved in acetone as the first solution, and 4,4′-diaminodiphenylmethane / acetone = 0.004 mol / 50 ml solution as the B solution. 4,4′-diamino-3,3′-dihydroxybiphenyl / methanol = 0.0001 mol / 10 ml solutions were prepared as solutions A, respectively, and cooled to about 4 ° C.

Thereafter, the solution A was added to the solution B and stirred. Subsequently, 10 ml of ion-exchanged water was added and stirred in an ice bath, and the first solution was further mixed, stirred for 20 minutes with ultrasonic waves at a frequency of 28 kHz, and reacted to precipitate polyamide. The obtained polyamide was observed with a scanning electron microscope (SEM), and it was confirmed that the polyamide was composed of flat particles close to monodispersion. The image is shown in FIGS. 8 (a) and 8 (b). The average particle size (major axis direction) of the polyamide fine particles was 1.143 μm, standard deviation 0.0947, coefficient of variation 8.52%, specific surface area 49.15 m ² / g. The thermal decomposition temperature (Td (5 wt% loss)) was 411 ° C., and the glass transition temperature (Tg) was not shown.

Example 9
Preparation of polyamide fine particles having hydroxyl groups on the particle surface First, as a first solution, 50 ml solution of 0.004 mol of 4,4′-biphenyldicarbonyl chloride dissolved in dioxane, and 4,4′-diaminodiphenyl ether / dioxane = B solution As a 0.0004 mol / 50 ml solution and a solution A, 2,4-diamino-6-hydroxypyrimidine / ion-exchanged water = 0.0001 mol / 10 ml solution were prepared and cooled to about 4 ° C.

Thereafter, the solution A was added to the solution B and stirred. Next, the first solution was mixed, stirred for 20 minutes with an ultrasonic wave having a frequency of 28 kHz, and reacted to precipitate polyamide. The obtained polyamide was observed with a scanning electron microscope (SEM), and it was confirmed that the polyamide was composed of spherical particles close to monodisperse. The image is shown in FIGS. 9 (a) and 9 (b). These polyamide fine particles had an average particle size of 0.657 μm, a standard deviation of 0.0793, a coefficient of variation of 9.892%, and a specific surface area of 65.08 m ² / g. The thermal decomposition temperature (Td (5 wt% loss)) was 437 ° C., and the glass transition temperature (Tg) was not shown.

Test example 1
The functional groups on the surface of the polyamide fine particles obtained in Example 3 were analyzed.
<Preparation of sample for analysis>
20 mg of the above-mentioned polyamide fine particles were placed in 2.5 ml of N-methylpyrrolidone, and stirred with an ultrasonic wave for about 30 minutes. To this solution, 0.7 ml of a silane coupling agent and 0.2 g of di-n-butyltin dilaurate are added and reacted in an airtight container at about 80 ° C. for 5 hours. Wash thoroughly. Then, it left still in the refrigerator for 1 day in the state disperse | distributed in acetone. The polyamide fine particles treated with the silane coupling agent were subjected to infrared spectroscopic analysis and EDX analysis associated with FE-SEM to confirm the presence of functional groups on the particle surface. "Spectrum One" (manufactured by PerkinElmer) as an infrared spectrometer, "S-4700" (manufactured by Hitachi, Ltd.) as a scanning electron microscope (SEM), and "EMAX-7000" (Horiba, Ltd.) as an EDX analyzer Made).
<Infrared spectroscopic analysis>
The infrared spectrum of the sample after the polyamide fine particles obtained in Example 3 were treated with the silane coupling agent and before the treatment was measured. For comparison, the infrared spectrum of the sample before and after the treatment with the silane coupling agent was also measured for polyamide fine particles having no functional group (functional group) corresponding to Example 3. About these, the difference spectrum was taken in the procedure as shown in Drawing 11 (1)-(4), and existence of a functional group was checked. According to the above procedure, comparing the spectra,
The difference spectrum obtained in the above (1) was similar to the infrared spectrum of 3,5-diaminobenzoic acid added to introduce a functional group.

In the difference spectra obtained in (2) and (3) above, a large peak characteristic of Si was observed in the vicinity of about 1100 cm ^−1, indicating that a silane coupling agent was attached.

  In the difference spectrum obtained in (4) above, both the infrared spectrum of 3,5-diaminobenzoic acid added to introduce a functional group and a peak characteristic of Si were observed.

From the result of such a Si-based peak, it was confirmed that a functional group was also present on the particle surface although physical adsorption occurred. Moreover, it turns out that the diamine which has a functional group is introduce | transduced in the molecular chain from the result of said (1).
<EDX analysis using FE-SEM>
Both the polyamide fine particles having a functional group and the polyamide fine particles having no functional group obtained in Example 3 were treated with a silane coupling agent and then subjected to EDX analysis using FE-SEM. The results are shown in FIGS. 12 (a) and 12 (b). From FIG. 12 (b), it can be seen that some physical adsorption occurs because the Si-based peak is slightly observed. On the other hand, comparing FIGS. 12 (a) and 12 (b), it can be clearly seen that FIG. 12 (a), that is, the polyamide fine particles in which the functional group is present, contains more Si. This result also coincides with the result of the infrared spectrum.

  From these analysis results, it can be seen that in Example 3, a carboxyl group was introduced on the particle surface.

1 (a) and 1 (b) are diagrams showing the particle shape of the polyamide fine particles obtained in Example 1. FIG. FIGS. 2A and 2B are diagrams showing the particle shape of the polyamide fine particles obtained in Example 2. FIG. 3 (a) and 3 (b) are diagrams showing the particle shape of the polyamide fine particles obtained in Example 3. FIG. 4 (a) and 4 (b) are diagrams showing the particle shape of the polyamide fine particles obtained in Example 4. FIG. FIGS. 5A and 5B are diagrams showing the particle shape of the polyamide fine particles obtained in Example 5. FIG. 6 (a) and 6 (b) are views showing the particle shape of the polyamide fine particles obtained in Example 6. FIG. FIGS. 7A and 7B are diagrams showing the particle shape of the polyamide fine particles obtained in Example 7. FIG. FIGS. 8A and 8B are views showing the particle shape of the polyamide fine particles obtained in Example 8. FIG. 9 (a) and 9 (b) are diagrams showing the particle shape of the polyamide fine particles obtained in Example 9. FIG. FIG. 10A is a schematic view showing a state in which the functional group of the functional polyamide fine particles reacts with the silane coupling agent. FIG. 10B is a schematic diagram showing that the polyamide fine particles having no functional group do not react with the silane coupling agent. 6 is a diagram illustrating a procedure of an analysis method of Test Example 1. FIG. It is a figure which shows the result of the EDX analysis of Test Example 1. FIG. 12A shows the analysis result of the polyamide fine particles having a functional group on the particle surface. FIG. 12 (b) shows the analysis result of polyamide fine particles having no functional group on the particle surface.

Claims (13)

In a method of synthesizing a polyamide from an acid chloride and a diamine compound,
(A) a first step in which at least one of an acid chloride and a diamine compound has a functional group and a first solution containing the acid chloride and a second solution containing the diamine compound are prepared; and b) a second step of mixing the first solution and the second solution in the presence of a solvent that is soluble in both the solvent of the first solution and the second solution and precipitating polyamide fine particles from the mixed solution;
A process for producing functional polyamide fine particles, comprising: The production method according to claim 1, wherein the second solution further contains a diamine compound having no functional group. The production method according to claim 2, wherein the second solution is obtained by mixing a solution containing a diamine compound having a functional group and a solution containing a diamine compound not having a functional group. The production method according to any one of claims 1 to 3, wherein the solvent that is soluble in both the solvent of the first solution and the second solution is at least one of water and a solvent having a hydroxyl group. The manufacturing method of Claim 4 in which the solvent which has a hydroxyl group contains at least 1 sort (s) of C1-C10 alcohol. The method in any one of Claims 1-4 which perform a 2nd process under stirring by an ultrasonic wave. The method in any one of Claims 1-6 in which the solvent in a 1st solution contains at least 1 sort (s) of acetone and a dioxane. The method in any one of Claims 1-6 in which the solvent in a 2nd solution contains at least 1 sort (s) of acetone and a dioxane. Functional polyamide fine particles obtainable by the method according to claim 1. Functional polyamide fine particles obtained by the method according to any one of claims 1 to 8 and having an average particle size of 0.01 to 5 µm. The functional polyamide fine particles according to claim 9 or 10, wherein the functional polyamide fine particles exhibit a glass transition temperature. The functional polyamide fine particles according to claim 9 or 10, wherein the functional polyamide fine particles do not exhibit a glass transition temperature. A method for confirming the presence of a functional group present on the surface of a polyamide fine particle by infrared spectroscopy and / or energy dispersive X-ray spectroscopy, which can react with the functional group prior to the analysis method A method for analyzing the surface of polyamide fine particles, wherein the surface of the polyamide fine particles is pretreated with a silane coupling agent.