JP3482808B2 - Method for producing thermoplastic polyurethane-based spherical powder - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a thermoplastic polyurethane spherical powder which is useful for adhesives, powder coatings and the like. More specifically, it relates to a method for producing a thermoplastic polyurethane-based spherical powder that is not affected by the type of raw material or the physical properties of the resulting polyurethane.

[0002]

2. Description of the Related Art Various methods for producing a thermoplastic polyurethane powder resin have hitherto been proposed. As a general method for producing a polyurethane resin powder, (1) a method of pulverizing an already produced resin, (2) a method of non-aqueous dispersion polymerization, (3) a method of aqueous emulsion, and (4) resin A method for precipitating a resin from a solution has already been reported.

The pulverization method, which is the first method, includes, for example, cooling of the resin with liquid nitrogen in order to efficiently pulverize it because the resin to be pulverized is a thermoplastic and is often a tough material. A fairly costly method is needed. Further, in the freeze pulverization, in addition to the cost of the refrigerating agent and the pulverizing device, dust is generated during the pulverizing process, and therefore a collecting device for the dust is also required. Furthermore, the shape of the crushed resin is not spherical like pearls, and the sizes are uneven,
There was a problem that the flowability during molding was poor and voids were easily generated.

As a non-aqueous dispersion polymerization method which is the second method, a method for producing a powdered polyurethane resin using a surfactant and a dispersant is known (Japanese Patent Publication No. 57-29485, JP-A 1-245013). Issue). This non-aqueous dispersion polymerization method is a method in which the raw materials are dissolved or dispersed in a poor solvent and then the polymerization reaction is carried out. Even if the raw materials are dissolved in the solvent, the resin will be deposited after the polymerization reaction. After the reaction
The resin and the solvent are separated and recovered, and the powder resin is obtained through a drying process of the precipitated powder resin. The powder resin obtained by the non-aqueous dispersion polymerization method has a pearl-like spherical shape,
It is also characterized by a narrow particle size distribution.

However, in the method for producing a powdered polyurethane resin disclosed in Japanese Patent Publication No. 57-29485 and Japanese Patent Laid-Open No. 1-245013, for example, a powdered body using paraphenylene diisocyanate is difficult to obtain by this method, and In a polyurethane with a large amount of hard segment, it is very difficult to pulverize it because of the strong cohesive force due to the hard segment.
There are problems such as the types of raw materials that can be applied and the physical properties of the resulting powdered polyurethane resin.

JP-A-2-6519 discloses a technique relating to a method for producing a polyurethane-based polymer gel by a non-aqueous dispersion polymerization method. The polyurethane-based polymer gel obtained by this method is Since the gel was already three-dimensionally crosslinked, it had poor moldability.

As a third method, a method using an aqueous emulsion, a method of producing an aqueous emulsion and coagulating the emulsion to produce a resin powder has been proposed, but the characteristics of the resin to which this method can be applied are limited. Has been done.

In the precipitation method, which is the fourth method, a powder is obtained by the following steps. First step (a) a step selected from the step of dissolving the manufactured resin in a good solvent (b) the step of manufacturing the resin in a good solvent. 2nd step (a) A poor solvent is added to the resin solution for pulverization, the solvent is separated and recovered, and the step for drying the powdered resin (ii) The poor solution is added to the resin solution for precipitation, and the solvent is separated and recovered, After the precipitated resin is dried, the step (g) of pulverizing the resin solution is dropped into a poor solvent to make it powder,
A step selected from the steps of separating and collecting the solvent and drying the powder resin.

The method (a) in the second step requires caution and skill in pulverization in the precipitation step, and the method (ii) is crushed after all, so that the same problems as in the first method are likely to occur. The method (b) is a manufacturing method described in Japanese Patent Laid-Open No. 4-202330, but this method requires two reaction vessels and the dropping step tends to take a long time. There were problems such as being disadvantageous.

[0010]

SUMMARY OF THE INVENTION The present invention solves the problems of the heretofore known technologies and can be applied to all kinds of raw materials, and also enables the production of polyurethane powders of all physical properties. It is an object to provide a method for producing a thermoplastic polyurethane-based spherical powder body.

[0011]

[Means for Solving the Problems]

In view of the above circumstances, the inventors of the present invention have made extensive studies on a rational method for producing a thermoplastic polyurethane-based spherical powder body, and as a result, have completed the present invention. That is, the present invention is the following (1) to ( 4 ).

[0012]

( 1 ) A method for producing a thermoplastic polyurethane-based spherical powder comprising the following steps. (First step) A step of reacting the active hydrogen group-containing compound (A) with the organic polyisocyanate (B) in a good solvent (C) to obtain an isocyanate group-terminated prepolymer. (Second step) After the poor solvent (D) and the dispersion stabilizer (E) are added to the obtained solution of the isocyanate group-terminated prepolymer, the active hydrogen group-containing compound (A) is added to react, precipitate, and powder. And a step of forming a thermoplastic polyurethane-based spherical powder body. (Third step) A step of separating and drying the produced thermoplastic polyurethane-based spherical powder body from the liquid phase.

( 2 ) A method for producing a thermoplastic polyurethane-based spherical powder body, which comprises the following steps. (First step) The active hydrogen group-containing compound (A) and the organic polyisocyanate (B) are reacted in a good solvent (C) to give an isocyanate group-terminated prepolymer, and the active hydrogen group-containing compound (A) is further added. And react to obtain a thermoplastic polyurethane resin solution. (Second step) To the obtained thermoplastic polyurethane resin solution, a poor solvent (D) and a dispersion stabilizer (E) are added, and the dissolved thermoplastic polyurethane resin is precipitated and powdered to form a thermoplastic polyurethane. Of producing a spherical powder body. (Third step) A step of separating and drying the produced thermoplastic polyurethane-based spherical powder body from the liquid phase.

( 3 ) A method for producing a thermoplastic polyurethane spherical powder comprising the following steps. (First step) A step of reacting the active hydrogen group-containing compound (A) with the organic polyisocyanate (B) in a good solvent (C) to obtain a hydroxyl group-terminated prepolymer. (Second step) After adding the poor solvent (D) and the dispersion stabilizer (E) to the obtained solution of the hydroxyl group-terminated prepolymer, the organic polyisocyanate (B) is added to react, precipitate, powderize, and heat. A step of producing a plastic polyurethane-based spherical powder. (Third step) A step of separating and drying the produced thermoplastic polyurethane-based spherical powder body from the liquid phase.

( 4 ) A method for producing a thermoplastic polyurethane spherical powder comprising the following steps. (1st step) The active hydrogen group-containing compound (A) and the organic polyisocyanate (B) are reacted in a good solvent (C) to give a hydroxyl group-terminated prepolymer, and the organic polyisocyanate (B) is further added and reacted. , A step of obtaining a thermoplastic polyurethane resin solution. (Second step) To the obtained thermoplastic polyurethane resin solution, a poor solvent (D) and a dispersion stabilizer (E) are added, and the dissolved thermoplastic polyurethane resin is precipitated and powdered to form a thermoplastic polyurethane. Of producing a spherical powder body. (Third step) A step of separating and drying the produced thermoplastic polyurethane-based spherical powder body from the liquid phase.

Specific raw materials used in the present invention will be described below. The active hydrogen group-containing compound (A) in the present invention is divided into a polymer polyol and a chain extender.

As the polymer polyol, for example, polyester polyol, polyester amide polyol,
Polyether polyols, polyether ester polyols, polycarbonate polyols and the like can be mentioned. The preferred number average molecular weight is 500 to 10,000, more preferably 1,000 to 5,000, and the preferred average functional group number is 1.5 to 10.0, more preferably 1.9-
It is 3.0. The “number average molecular weight” of the polymer polyol in the present invention is calculated from the average number of functional groups and the amount of end groups quantified by the end group quantification method.

Examples of the polyester polyol and polyester amide polyol include known succinic acid, tartaric acid, adipic acid (hereinafter abbreviated as AA), sebacic acid, azelaic acid, terephthalic acid, isophthalic acid, hexahydroterephthalic acid, hexahydro. Dicarboxylic acids such as isophthalic acid, their acid esters, acid anhydrides, etc., and ethylene glycol (hereinafter abbreviated as EG), 1,2-propanediol (hereinafter abbreviated as 1,2-PD), 1,
3-PD, 1,2-butanediol, (hereinafter 1,2-B
Abbreviated as D) 1,3-BD, 1,4-BD, 1,5-
Pentanediol, 1,6-hexanediol (hereinafter abbreviated as 1,6-HD), 3-methyl-1,5-pentanediol, neopentyl glycol, 1,8-octanediol, 1,9-nonanediol, Ethylene oxide of diethylene glycol, cyclohexane-1,4-diol, cyclohexane-1,4-dimethanol, dimethylolheptane, diol dimer acid, trimethylolpropane, glycerin, hexanetriol, quadrol or bisphenol A (hereinafter abbreviated as EO). Or propylene oxide (hereinafter abbreviated as PO) adduct, bisphenol A, hydrogenated bisphenol A, pentaerythritol, sorbitol, sugar alcohols such as sucrose, glucose and fructose Low molecular weight polyols having an average molecular weight from 62 to 500, or ethylenediamine, tetramethylenediamine, (hereinafter abbreviated as IPDA) hexamethylenediamine, xylylenediamine, isophoronediamine,
Low molecular weight polyamines having a number average molecular weight of 62 to 500, such as diethylenetriamine, monoethanolamine (hereinafter MEA
And a compound obtained by a dehydration condensation reaction with a low molecular weight amino alcohol such as diethanolamine alone or with a mixture thereof. Further, lactone-based polyester polyols obtained by cleavage polymerization of cyclic ester (i.e., lactone) monomers such as ε-caprolactone, alkyl-substituted ε-caprolactone, δ-valerolactone, and alkyl-substituted δ-valerolactone can be mentioned.

Examples of the polyether polyol include EO, PO, butylene oxide, amylene oxide, alkyl glycidyl ether such as methyl glycidyl ether, phenyl glycidyl ether, etc., using the low molecular weight polyol used in the above polyester polyol as an initiator. EO alone or EO from cyclic ether monomers such as aryl glycidyl ether and tetrahydrofuran
It can be obtained by addition-polymerizing a mixture of and other monomers by a known method.

Examples of the polyether-ester polyol include compounds produced from the above-mentioned polyether polyol and the above-mentioned dicarboxylic acid, acid anhydride and the like.

Examples of the polycarbonate polyol include compounds obtained by reacting the low molecular weight polyol used in the above polyester polyol with diethyl carbonate, diphenyl carbonate or the like.

Examples of the chain extender in the present invention include the aforementioned low molecular weight polyols, low molecular weight polyamines, low molecular weight amino alcohols, and mixtures thereof.

Examples of the organic polyisocyanate (B) in the present invention include ethylene diisocyanate,
Tetramethylene diisocyanate, hexamethylene diisocyanate (hereinafter abbreviated as HDI), dodecamethylene diisocyanate, 2,2,4-trimethylhexane diisocyanate, 2,4,4-trimethylhexane diisocyanate lysine diisocyanate, 2,6-diisocyanate methylcaproate , Bis (2-isocyanatoethyl) fumarate, bis (2-isocyanatoethyl) carbonate, isophorone diisocyanate (hereinafter abbreviated as IPDI), dicyclohexylmethane diisocyanate, 1,4-cyclohexylene diisocyanate, methylcyclohexylene diisocyanate,
Ortho-xylylene diisocyanate, meta-xylylene diisocyanate, para-xylylene diisocyanate,
2,4-Tolylene diisocyanate (hereinafter 2,4-TD
I)), 2,6-TDI, 4,4'-diphenylmethane diisocyanate (hereinafter abbreviated as 4,4'-MDI), 2,4'-MDI, 2,2'-MDI, naphthylene diisocyanate, Examples thereof include paraphenylene diisocyanate (hereinafter abbreviated as PPDI), polyphenylene polymethylene polyisocyanate, crude TDI, and a mixture of two or more thereof. Further, modified products of these polyisocyanates (carbodiimide group, uretonimine group, uretdione group, isocyanurate group, urea group, buret group, allophanate group-containing modified polyisocyanate, etc.) can also be used.

The good solvent (C) used in the present invention is not particularly limited as long as it can dissolve the raw material and the polyurethane resin. For example, acetone,
Ketones such as methyl ethyl ketone and cyclohexanone;
Ethers such as diethyl ether, dioxane and tetrahydrofuran; aromatic hydrocarbons such as benzene, toluene and xylene; halogenated hydrocarbons such as methylene chloride, chlorobenzene, trichlene, barclen; esters such as ethyl acetate and butyl acetate Amides such as dimethylformamide; sulfoxides such as dimethylsulfoxide; alcohols such as methanol, ethanol and isopropanol; pyridine, N-methylpyrrolidone and a mixture of two or more thereof.

Examples of the poor solvent (E) in the present invention include normal hexane, normal heptane, normal octane, isooctane, petroleum benzine, ligroin,
Aliphatic and alicyclic hydrocarbons such as mineral spirits, cyclohexane, kerosene and petroleum naphtha; liquid plasticizers such as dioctyl phthalate and dioctyl adipate; and liquid paraffin.

The dispersant (F) used in the present invention includes those having an active hydrogen group in the molecule (F1) and those not having an active hydrogen group in the molecule (F2). In order to subdivide the active hydrogen group-containing compound, which is a constituent of the spherical powdery body, and to disperse it uniformly in the poor solvent, there is a high affinity between the active hydrogen group-containing compound and the poor solvent. It is a structure that exists in two molecules.

Dispersant (F1) containing this active hydrogen group
As the above, a reaction product of an organic oligomer containing an active hydrogen group and having an unsaturated bond, and an ethylenically unsaturated monomer having a side chain of 6 or more carbon atoms is preferable. As the dispersant (F2) containing no active hydrogen group, (1) an organic oligomer containing no active hydrogen group and having an unsaturated bond, and 6 carbon atoms
A reaction product with an ethylenically unsaturated monomer having the above side chain, (2) the active hydrogen group of the active hydrogen group-containing dispersant described above is a monoisocyanate such as phenyl isocyanate, or an active hydrogen group such as a monocarboxylic acid. A reaction product obtained by reacting a masking agent is suitable.

The organic oligomer containing an active hydrogen group and having an unsaturated bond is, for example, a polyester polyol produced by using an unsaturated bond-containing glycol or an unsaturated bond-containing dicarboxylic acid as a part of glycols or dibasic acids. , A polyether polyol produced by using an unsaturated bond-containing glycol as a starting material, a hydroxyl group-terminated polyester having a number average molecular weight of 2,000 or less, a polyether, a polycarbonate and the like and obtained by an esterification reaction of an unsaturated bond-containing dicarboxylic acid. In addition to the above-mentioned polyols and the like, polyolefin polyols and the like can be mentioned. Examples of the unsaturated bond-containing glycol include 2-butene-1,4-diol and glycerin monoallyl ether. Examples of unsaturated bond-containing dicarboxylic acids include maleic acid and itaconic acid.

Examples of the organic oligomer containing no active hydrogen group and having an unsaturated bond include, for example, an OH consisting of a polyol which is a raw material of the polyester polyol described above and a monool.
Polyester, polyether monool and unsaturated bond-containing dicarboxylic acid composed of a component and a COOH component using a dibasic acid as a raw material of the polyester polyol and an unsaturated bond-containing dicarboxylic acid such as maleic acid, fumaric acid and itaconic acid And a dehydration reaction product thereof, a polymer of a diene monomer such as polybutadiene and polyisoprene, and the like.

The number average molecular weight of these organic oligomers is preferably 500 to 10,000, particularly preferably 500 to 9,000. Further, the unsaturated bond concentration is preferably 10 mol or less on average per molecule of the organic oligomer.

Examples of the ethylenically unsaturated monomer having a side chain of 6 or more carbon atoms include 1-octene, 1- or 2
-Nonene, 1- or 2-decene, 1- or 2-heptadecene, 2-methyl-1-nonene, 2-methyl-1-decene, 2-methyl-1-dodecene, 2-methyl-1-hexadecene, 2 Vinyl such as -methyl-1-heptadecene,
Propenyl or isopropenyl group-containing aliphatic straight-chain unsaturated hydrocarbon, acrylic acid or methacrylic acid and 2-ethylhexyl alcohol, hexyl alcohol and the like having 6 carbon atoms
In addition to the above-mentioned esters with aliphatic alcohols or cycloaliphatic alcohols having 6 or more carbon atoms such as cyclohexanol, norbonal and adamantanol, reaction products of acrylic acid and polycaprolactone diol, for example, manufactured by Daicel Chemical Industries, Ltd. Praxel FA-4 etc. are mentioned.

There are no particular restrictions on the reaction between the unsaturated bond-containing organic oligomer and the ethylenically unsaturated monomer, but generally known reactions in radical polymerization reactions such as benzoyl peroxide and azobisisobutyronitrile. An initiator or a solvent such as ethyl acetate or cyclohexane can be used. Furthermore, the ratio of the organic oligomer having an unsaturated bond to the ethylenically unsaturated monomer having 6 or more carbon atoms is
Organic oligomer / ethylenically unsaturated monomer = 100/2
0-100 / 400 (weight ratio) is preferable. When the ratio of the ethylenically unsaturated monomer to 100 parts by weight of the organic oligomer is less than 20 parts by weight, sufficient performance as a dispersant cannot be obtained. If it exceeds 400 parts by weight, the balance of the raw material dispersion in the reaction system is lost during the non-aqueous dispersion polymerization, and the effect as a dispersant cannot be sufficiently exhibited.

In the present invention, the process for producing a specific thermoplastic polyurethane powder will be described in more detail.

First, the present invention and the invention described in Japanese Patent Application Laid-Open No. 1-245013 (hereinafter abbreviated as Special A) and Japanese Patent Application Laid-Open No. 2-65.
The invention will be compared with the invention described in Japanese Patent Publication No. 19 (hereinafter abbreviated as Special B). The present invention and the features A and B have some common points regarding the dispersion stabilizer. However, in the present invention, the reaction is carried out in a good solvent system at the beginning of the reaction, whereas the characteristics A and B are different in that the reaction is performed from the beginning to the powdering in a poor solvent system. In the present invention, since a good solvent is used, the type of raw material (in particular, it becomes possible to manufacture a thermoplastic polyurethane-based spherical powder using PPDI) and the molecular structure of polyurethane (for example, a large amount of a chain extender introduced, In other words, it has versatility that there is no limitation for polyurethane with a large amount of hard segment).

Next, when the present invention is compared with the invention described in JP-A-4-202330 (hereinafter abbreviated as "special C"), the present invention shows that the polyurethane resin obtained by reacting with a good solvent system at the beginning of the reaction. Special C is a method of dropping a polyurethane resin solution into a poor solvent, while adding a poor solvent to the solution. Since this feature C is a method of dropping a resin solution having a large viscosity, the dropping step tends to take longer as the manufacturing scale increases. In addition, this special C method requires at least two reaction pots, which is a very disadvantageous method industrially. On the other hand, the method of the present invention is advantageous in terms of production cost because it takes less time to charge the poor solvent and only one reactor is required.

[0037] In the present invention, as a synthetic method of a precursor of the thermoplastic polyurethane-based powder body, there is (1) flop prepolymer method.

[0038]

[0039]

In the prepolymer method of ( 1 ), further (a)
There are two methods: an isocyanate group-terminated prepolymer method and a (b) hydroxyl group-terminated prepolymer method.

In the isocyanate group-terminated prepolymer method (a), a part of the active hydrogen group-containing compound to be used is dissolved in a good solvent, and all of the organic polyisocyanate is reacted therewith to prepare an isocyanate group-terminated prepolymer. To get Next, (a) a step of charging an active hydrogen group-containing compound, (b) a step of charging and depositing a poor solvent and a dispersion stabilizer, and pulverizing, separating from the liquid phase and drying to obtain a desired thermoplastic polyurethane system. A spherical powder body is obtained. In the above-mentioned steps, the order of the step (a) and the step (b) is not particularly limited. The low molecular weight polyol, low molecular weight polyamine, and low molecular weight amino alcohol described above are preferable as the active hydrogen group-containing compound used in the step (a).

In the hydroxyl group-terminated prepolymer method (b),
All of the active hydrogen group-containing compounds used are dissolved in a good solvent, and a part of the organic polyisocyanate used for this is reacted to obtain a hydroxyl-terminated prepolymer. Then
After (c) a step of charging an organic polyisocyanate, (d) a step of charging and depositing a poor solvent and a dispersion stabilizer and pulverizing, the liquid phase is separated and dried to obtain a target thermoplastic polyurethane spherical powder. . In the above-mentioned process, the order of the process (c) and the process (d) is not particularly limited.

The molar ratio of the isocyanate group to the hydroxyl group in this prepolymerization reaction is as follows: (a) In the prepolymerization reaction at the isocyanate group end, isocyanate group: active hydrogen group = 1.1: 1.0
5.0: 1.0, preferably 1.3: 1.0 to 3.0:
1.0 (b) In the prepolymerization reaction of hydroxyl group end, isocyanate group: hydroxyl group = 1.0: 1.1 to 1.0: 5.0,
It is preferably 1.0: 1.3 to 1.0: 3.0.

In the prepolymer method, the final molar ratio of all isocyanate groups to all water active hydrogen groups (total molar ratio of all isocyanate groups to all water active hydrogen groups) is the hydroxyl group terminated prepolymer method, isocyanate terminated prepolymer. In both methods, all isocyanate groups: all active hydrogen groups = 1.0
0: 0.80 to 1.00: 1.20, preferably 1.0
It is 0: 0.95 to 1.00: 1.10.

The synthesized by such a flop prepolymer method, then, deposition, the shape of the powdered thermoplastic polyurethane-based spherical powder body are spherical pearly, average particle size is 1～500Myu. The "average particle size" in the present invention is the value of the cumulative percentage of 50% in the particle size distribution curve measured by a laser particle size analyzer.

The reaction temperature in the prepolymer reaction temperature and the second stage in the flop prepolymer method, temperature conditions without the side reaction of the isocyanate groups other than the urethane reaction, preferably 20 to 120 ° C., more preferably 30 to 100 ° C. Is. Examples of the reaction device include a reaction kettle equipped with a stirrer. In order to accelerate the reaction, a metal catalyst such as dibutyltin dilaurate (hereinafter abbreviated as DBTDL) commonly used in the production of polyurethane as a urethane-forming catalyst and a urethane-forming catalyst such as a tertiary amine catalyst such as triethylamine may be used. it can.

The solid content before charging the poor solvent (D) and the dispersion stabilizer (E) in the present invention may be such that the poor solvent and the dispersion stabilizer can be easily added and mixed. The viscosity is 20,000 cP or less, preferably 1
It is 5,000 cP or less, and the solid content at this time is generally 20 to 90% by weight, preferably 30 to 80% by weight. The viscosity before charging the poor solvent and dispersion stabilizer is 2
If it exceeds 10,000 cP, it becomes difficult to obtain a spherical powder.

The content of the dispersion stabilizer is preferably 0.05 to 45% by weight with respect to the polyurethane spherical powder,
0.1-40% by weight is particularly preferred. If it is less than 0.05% by weight, the polyurethane resin and the prepolymer are not uniformly dispersed in the reaction system, and it is difficult to obtain a spherical powder. 45
When the content is more than 5% by weight, it is difficult for an adhesive, a molded product or a coating film using the spherical powder to have sufficient strength to endure practical use.

The amount of the poor solvent charged is 0.3 to 5.0 times, preferably 0.4 to 3.0 times the total weight of the stage before charging the poor solvent. When it is less than 0.3 times, the polyurethane-based spherical powder is less likely to be precipitated from the solution, and when it exceeds 5.0 times, it is disadvantageous in manufacturing cost.

At the time of charging the poor solvent and the dispersion stabilizer,
The stirring may be carried out, but it is preferable to stop the stirring because "damage" is less likely to occur. After charging the poor solvent and the dispersion stabilizer, the stirring is immediately restarted, and the stirring is continued until the step of separating the spherical powder from the liquid phase.

The thermoplastic polyurethane-based spherical powder thus obtained is recovered from the liquid phase by filtering or decanting, and then drying under normal pressure or reduced pressure and at room temperature or heating. It

The thermoplastic polyurethane-based spherical powder obtained by the present invention contains, if necessary, an antioxidant, an ultraviolet absorber, a pigment, a dye, a flame retardant, a hydrolysis inhibitor, a lubricant, a plasticizer, Additives such as a filler and a storage stabilizer can be appropriately blended. As for the compounding method, the respective components may be mixed in the form of powder as they are, or the spherical powder and the respective additives may be dissolved or dispersed in a solvent and mixed, or dioctyl phthalate widely used as a plasticizer. When the additive is a liquid having poor solubility as described above, a spherical powder body may be dispersed in the additive. As a compounding method, a known method can be applied, and a ball mill, a sand grind mill, a shaker, a triple roll, an extruder, a kneader, an air gun, a stirrer and the like can be used as a compounding device.

[0053]

EXAMPLES The present invention will be described in more detail with reference to Examples below, but the present invention should not be construed as being limited thereto. In the examples below,
All "parts" mean "parts by weight" and all "%" mean "% by weight".

[Synthesis of Dispersion Stabilizer Solution] Synthesis Example In a reactor equipped with a stirrer, a thermometer, a distillation column and a nitrogen gas inlet tube, 762 parts of AA, 49 parts of maleic anhydride, EG3
Charge 86 parts and stir with nitrogen gas while stirring to 150
The esterification reaction was carried out at ℃ and atmospheric pressure. When the condensed water is no longer discharged, 0.1 part of tetrabutyl titanate is charged, and the pressure in the reaction system is gradually reduced to 0.5 mmHg.
The reaction temperature was gradually raised to 190 ° C. and the reaction was continued.
The number average molecular weight of the obtained polyester was 2,000, and the iodine value was 12.7 gI / 100 g. Subsequently, 74 parts of the above polyester and 150 parts of butyl acetate were charged into a reactor equipped with a stirrer, a thermometer, a dropping funnel, a cooling tower and a nitrogen gas introducing tube. 110 ° C while flowing nitrogen gas
It heated and stirred until it became. Then, a dissolved mixture of 75 parts of 2-ethylhexyl methacrylate and 1 part of benzoyl peroxide was added dropwise from the dropping funnel over 1 hour. After completion of the dropping, the temperature was heated to 130 ° C. and the reaction was further performed for 2 hours to obtain a dispersion stabilizer solution D-1. The solid content of D-1 is 5
It was 0%.

[0055]

[Of the thermoplastic polyurethane-based spherical powder body
Synthesis] Example 1 In a reactor equipped with a stirrer, a thermometer, and a nitrogen gas introduction tube ,
705.8 parts of polyol (2) and 700 parts of methyl ethyl ketone as a good solvent were charged, and the mixture was stirred at 50 ° C. for 30 minutes. Next, 235.0 parts of IPDI were charged, and 90
The reaction was carried out at 0 ° C. for 2 hours while stirring to obtain an isocyanate group-terminated prepolymer solution. Then, the stirring was stopped, and 2000 parts of Isopar G (manufactured by Exxon Chemical Co.) and 100 parts of D-1 were charged as a poor solvent. Then, the stirring was restarted, and the stirring was continued until the powder body was separated from the liquid phase. Then, the temperature was controlled at 90 ° C. for 2 hours and then cooled to 30 ° C., 300 parts of isopropanol and 57.
An alcohol alcohol solution of 0 parts and 2.2 parts of MEA was charged and reacted to obtain a thermoplastic polyurethane resin solution. After centrifugal filtration, 10 mmHg in a vacuum dryer,
It was dried at 40 ° C. for 12 hours to obtain a thermoplastic polyurethane-based spherical powder body P-2. The average particle size of P-2 is 25
It was 0 μ. The polyol (2) is 1,4-B
It is a polyester diol having a number average molecular weight of 1,000 and a terminal hydroxyl group, obtained from D and AA.

Example 2 A reactor similar to that used in Example 1 was charged with 82 parts of the polyol (3).
0.0 part and 250 parts of methyl isobutyl ketone as a good solvent were charged, and the mixture was stirred at 50 ° C. for 30 minutes. Then P
143.4 parts of PDI was charged and reacted at 90 ° C. for 2 hours with stirring to obtain an isocyanate group-terminated prepolymer solution. After cooling to 40 ° C., 1,4-BD was added to 3
After charging 6.6 parts, the mixture was heated again to 90 ° C. and reacted for 2 hours. Then, the stirring was stopped, and 750 parts of IP Solvent 1620 (made by Idemitsu Petrochemical Co., Ltd.) and D- were used as a poor solvent.
40 parts of 1 were prepared. Then, the stirring was restarted, and the stirring was continued until the powder body was separated from the liquid phase. Then, at 90 ℃ 3
The temperature was adjusted for 0 minutes, the temperature was cooled to 40 ° C., the mixture was centrifugally filtered, and then dried at 10 mmHg and 60 ° C. for 12 hours in a vacuum dryer to obtain a thermoplastic polyurethane powder P-3. P-
The average particle size of 3 was 100μ. The polyol (3) represents a polycarbonate diol having a number average molecular weight of 2,000 and a terminal hydroxyl group, which is obtained by a dephenol reaction of 1,6-HD and diphenyl carbonate.

Example 3 A reactor similar to that used in Example 1 was charged with 67% of polyol (1).
9.3 parts, 40.8 parts of 1,4-BD and 250 parts of butyl acetate as a good solvent were charged, and the mixture was stirred at 40 ° C. for 30 minutes. Next, 201.1 parts of IPDI was charged and the temperature was 90 ° C.
The reaction was carried out for 2 hours with stirring to obtain a hydroxyl group-terminated prepolymer solution. Then, the stirring was stopped and 750 parts of normal octane and 100 parts of D-1 as a poor solvent were charged. Then, the stirring was restarted, and the stirring was continued until the powder body was separated from the liquid phase. Then 2,4-TDI is 7
After charging 8.8 parts, the mixture was further reacted at 90 ° C. for 2 hours while stirring, cooled to 30 ° C., centrifugally filtered, and dried in a vacuum dryer at 10 mmHg and 40 ° C. for 12 hours to obtain a thermoplastic polyurethane. A spherical powder P-4 was obtained. P-4
Had an average particle size of 150μ.

Example 4 A reactor similar to that used in Example 1 was charged with 66 parts of the polyol (2).
8.7 parts, 60.2 parts of 1,4-BD and 250 parts of butyl acetate as a good solvent were charged, and the mixture was stirred at 40 ° C. for 30 minutes. Subsequently, 112.3 parts of HDI was charged and reacted at 90 ° C. for 2 hours while stirring to obtain a hydroxyl-terminated prepolymer solution. Then, 4,4'-MDI was added to 158.
Eight parts were charged, and the mixture was further reacted at 90 ° C. for 2 hours with stirring to obtain a thermoplastic polyurethane resin solution. Then, the stirring was stopped and isooctane as a poor solvent was added to 75
0 part and 60 parts of D-1 were charged. Then, the stirring was restarted, and the stirring was continued until the powder body was separated from the liquid phase. Then, the temperature was adjusted to 80 ° C for 2 hours, cooled to 30 ° C, centrifugally filtered, and then dried at 10 mmHg and 40 ° C for 12 hours in a vacuum dryer.
After drying for an hour, a thermoplastic polyurethane spherical powder P
-5 was obtained. The average particle size of P-5 was 100 μm.

Comparative Example 1 The same reactor as in Example 1 was charged with 82 parts of the polyol (3).
0.0 parts, 36.6 parts of 1,4-BD and 2000 parts of IP Solvent 1620 and 40 parts of D-1 as a poor solvent.
Parts were charged and stirred at 50 ° C. for 30 minutes. Then PPDI
143.4 parts of was charged and reacted at 90 ° C. for 4 hours with stirring. As a result, the resin agglomerated and no powder was obtained.

Comparative Example 2 Polyol (1) was added to a reactor similar to that used in Example 1 in an amount of 37
1.3 parts, 20 IP solvent 1620 as a poor solvent
100 parts of 00 parts and D-1 were charged and stirred at 50 ° C. for 30 minutes. Subsequently, 494.0 parts of 4,4′-MDI was charged and reacted at 90 ° C. for 4 hours while stirring to obtain an isocyanate group-terminated prepolymer dispersion liquid. Then 1,
When 133.7 parts of 4-BD was charged and reacted at 90 ° C., the resin gradually aggregated and a powder body could not be obtained.

[0062]

According to the present invention, a thermoplastic powder polyurethane type spherical powder can be obtained regardless of the kind of raw material. Also, existing thermoplastic polyurethane resins can be powdered. The thermoplastic polyurethane-based spherical powder obtained by the present invention can be applied to adhesives, powder coatings and the like.

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shin Konishi 1893-8 Endo, Fujisawa City, Kanagawa Prefecture (56) Reference JP-A-5-170927 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C08J 3/14 C08G 18/00-18/87

Claims (4)

(57) [Claims] 1. A method for producing a thermoplastic polyurethane-based spherical powder body, which comprises the following steps. (First step) A step of reacting the active hydrogen group-containing compound (A) with the organic polyisocyanate (B) in a good solvent (C) to obtain an isocyanate group-terminated prepolymer. (Second step) After the poor solvent (D) and the dispersion stabilizer (E) are added to the obtained solution of the isocyanate group-terminated prepolymer, the active hydrogen group-containing compound (A) is added to react, precipitate, and powder. And a step of forming a thermoplastic polyurethane-based spherical powder body. (Third step) A step of separating and drying the produced thermoplastic polyurethane-based spherical powder body from the liquid phase. 2. A method for producing a thermoplastic polyurethane spherical powder, which comprises the following steps. (First step) The active hydrogen group-containing compound (A) and the organic polyisocyanate (B) are reacted in a good solvent (C) to give an isocyanate group-terminated prepolymer, and the active hydrogen group-containing compound (A) is further added. And react to obtain a thermoplastic polyurethane resin solution. (Second step) To the obtained thermoplastic polyurethane resin solution, a poor solvent (D) and a dispersion stabilizer (E) are added, and the dissolved thermoplastic polyurethane resin is precipitated and powdered to form a thermoplastic polyurethane. Of producing a spherical powder body. (Third step) A step of separating and drying the produced thermoplastic polyurethane-based spherical powder body from the liquid phase. 3. A method for producing a thermoplastic polyurethane-based spherical powder body, which comprises the following steps. (First step) A step of reacting the active hydrogen group-containing compound (A) with the organic polyisocyanate (B) in a good solvent (C) to obtain a hydroxyl group-terminated prepolymer. (Second step) After adding the poor solvent (D) and the dispersion stabilizer (E) to the obtained solution of the hydroxyl group-terminated prepolymer, the organic polyisocyanate (B) is added to react, precipitate, powderize, and heat. A step of producing a plastic polyurethane-based spherical powder. (Third step) A step of separating and drying the produced thermoplastic polyurethane-based spherical powder body from the liquid phase. 4. A method for producing a thermoplastic polyurethane-based spherical powder body, which comprises the following steps. (1st step) The active hydrogen group-containing compound (A) and the organic polyisocyanate (B) are reacted in a good solvent (C) to give a hydroxyl group-terminated prepolymer, and the organic polyisocyanate (B) is further added and reacted. , A step of obtaining a thermoplastic polyurethane resin solution. (Second step) To the obtained thermoplastic polyurethane resin solution, a poor solvent (D) and a dispersion stabilizer (E) are added, and the dissolved thermoplastic polyurethane resin is precipitated and powdered to form a thermoplastic polyurethane. Of producing a spherical powder body. (Third step) A step of separating and drying the produced thermoplastic polyurethane-based spherical powder body from the liquid phase.