JP5681498B2 - Urethane resin particles - Google Patents

Description

  The present invention relates to urethane resin particles having an uneven surface and a sharp particle size distribution.

  The slush molding method can easily form products with complicated shapes such as undercut and deep drawing, and has advantages such as uniform wall thickness and good material yield. Widely used in automotive interior materials such as panels, console boxes and door trims. As a material for slush molding, a polyvinyl chloride resin has been conventionally used. However, depending on the usage environment, the plasticizer contained therein will move to the surface and the soft feeling will be lost. Further, when incineration is performed after scrapped vehicles, hydrogen chloride gas is generated depending on the incineration temperature, and the incinerator may be corroded.

  In order to solve these problems, a powder slush molding material made of a thermoplastic resin other than vinyl chloride has been developed. For example, a thermoplastic polyurethane elastomer having a number average molecular weight of 20,000 to 50,000 and a glass transition temperature of −35 ° C. or lower is used (Patent Document 1). In addition, a resin solvent in which a resin is dissolved in a solvent in advance is dispersed in an aqueous medium in the presence of a dispersing agent (auxiliary) such as a surfactant or a water-soluble polymer, and the solvent is removed by heating or decompression to form an interlining. There is known a method (dissolved resin suspension method) for obtaining resin particles having a particle size distribution suitable for adhesives and slush molding applications. (Patent Document 2)

Japanese Patent Laid-Open No. 11-49948 JP-A-10-338733

However, resin particles having a particle size distribution suitable for interlining adhesives and slush molding applications obtained by the dissolved resin suspension method have a true spherical surface, and when such resin particles are colored, the pigment is Sliding from the resin particles or aggregation of pigments on the surface of the particles occurs, and the original color does not appear. In addition, there is a method of agglomerating particles to obtain particles with an uneven surface in order to prevent aggregation of the pigment, but the particle size distribution is widened and has a particle size distribution suitable for interlining adhesives and slush molding applications. In order to obtain resin particles, a classification step is required, and the yield is also reduced.
An object of the present invention is to provide resin particles having an uneven shape on the particle surface and a sharp particle size distribution.

  The present invention is a urethane resin particle (C) having irregularities on the particle surface, a shape factor SF2 of 120 to 240, and a 90% particle diameter / 10% particle diameter of 2.0 to 3.0. .

By using the urethane resin particles of the present invention, it is possible to eliminate problems due to pigment slippage and aggregation while coloring the resin particle surfaces. In addition, since resin particles having a sharp particle size distribution can be produced without using inorganic fine particles, the obtained slush molding material does not impair performance such as electrical characteristics, thermal characteristics, and chemical stability. . Moreover, since a classification process is unnecessary, the fall of a yield can be suppressed.

The urethane resin particles (C) of the present invention have irregularities on the particle surface, and the shape factor SF2 is 120 to 240, preferably 120 to 160, and more preferably 120 to 140.
When the shape factor SF2 is less than 120, when coloring the particles, even if a colorant is added to the particles and the pigment particles are fixed on the surface, the pigment particles on the surface slide down due to the shear at the subsequent step, As the pigment particles aggregate, the original color does not develop. Moreover, when the aggregate of pigment particles becomes large, it becomes a foreign substance, and the quality of the product is deteriorated.
On the other hand, particles having an SF2 of over 240 have surface irregularities that make it difficult for the pigment to enter the gaps between the irregularities, resulting in poor pigment dispersion stability.

The shape factor SF2 indicates the ratio of irregularities in the shape of the particle, and the square of the perimeter PERI of the figure formed by projecting urethane particles onto the two-dimensional plane represented by the following formula (1) is represented by the area AREA. Divided by 100 / 4π.
SF2 = {(PERI) ² / (AREA)} × (100 / 4π) (1)
When the value of SF2 is 100, unevenness does not exist on the urethane particle surface, and as the SF2 value increases, the unevenness of the urethane particle surface becomes more prominent.

The urethane resin particles (C) preferably have a shape factor SF1 of 101 to 200 from the viewpoint of powder fluidity.
Here, the shape factor SF1 indicates the roundness of the shape of the particle, and the square of the longest diameter of the figure formed by projecting urethane particles onto the two-dimensional plane, represented by the following formula (2), is the figure area. Divide by AREA and multiply by 100π / 4.
SF1 = {(longest diameter) ² / (AREA)} × (100π / 4) (2)
When the value of SF1 is 100, the shape of the urethane particles is a true sphere, and the larger the value of SF1, the more irregular the particles.
The shape factors SF1 and SF2 are measured by taking a picture of urethane particles with a scanning electron microscope (for example, S-800: manufactured by Hitachi, Ltd.), a microscope (USB digital scale: manufactured by SCARA Co., Ltd.), etc. Examples thereof include a method of analyzing by introducing into an apparatus (for example, LUSEX3: manufactured by Nireco), and a method of measuring using a flow type particle image analyzer (for example, FPIA-3000: manufactured by Sysmex).

The urethane resin particles (C) of the present invention preferably have a volume average particle diameter of 1 to 700 μm, more preferably 10 to 500 μm, and still more preferably 50 to 300 μm.
When the volume average particle diameter of (C) is 1 μm or more, the powder flowability is good, the moldability at the time of slush molding is good, dust is hardly generated, and the working environment is good. When the volume average particle diameter of (C) is 700 μm or less, leveling is good during slush molding, and pinholes are hardly generated on the mold surface.
Here, the volume average particle diameter is a value of the particle diameter of 50% under a sieve measured by a laser light scattering method. Examples of the measuring instrument include Microtrac HRA particle size analyzer 9320-X100 (manufactured by Nikkiso Co., Ltd.).

Moreover, the 90% particle diameter / 10% particle diameter of the urethane resin particles (C) of the present invention is 2.0 to 3.0. Here, 90% particle diameter / 10% particle diameter refers to 90% particle diameter divided by 10% particle diameter.
If it is within this range, it is suitable for slush molding applications, the number of pinholes on the mold surface after slush molding is reduced, powder flowability is good, and a classification step is not required.

The urethane resin (D) constituting the urethane resin particles (C) of the present invention has a urea group concentration of 0.5 to 10% by weight and a total of the urethane group concentration and the urea group concentration of 4 to 20% by weight. It is preferable that the melting point is 160 to 260 ° C and the glass transition temperature is -65 to 0 ° C.
Since the urea group remarkably improves the strength, solvent resistance, and wear resistance of the urethane resin (D), when the urea group is contained, the performance of the urethane resin particles (C) can be greatly improved. When the urea group is in the range of 0.5 to 10% by weight, the effect of improving the strength, solvent resistance, and abrasion resistance due to the urea group is remarkable, and when the urethane resin particles (C) are molded, Since the melting point and melt viscosity can be kept low, the thermal energy required during molding can be reduced. The urea group concentration is preferably 0.5 to 10% by weight, more preferably 1.0 to 7.0% by weight, and most preferably 1.5 to 5.0% by weight.
At the same time, the urethane group is improving the performance of the urethane resin (D) in the same manner as the urea group, and the total of the urethane group concentration and the urea group concentration is preferably 4 to 20% by weight, more preferably 6 to 15% by weight. Preferably, 8 to 12% by weight is most preferable. The urethane group concentration and urea group concentration in the present invention are the weight percent concentrations of urethane groups and urea groups with respect to the urethane resin (D).

The melting point of the urethane resin (D) constituting the urethane resin particles (C) of the present invention is preferably 160 to 260 ° C, and more preferably 210 to 250 ° C. If melting | fusing point is 160-260 degreeC, it is excellent in the blocking property of particle | grains in a general preservation | save environment, and can reduce the thermal energy at the time of shaping | molding. The glass transition temperature of (D) is preferably −65 to 0 ° C., more preferably −50 to −10 ° C. If the glass transition temperature is −65 to 0 ° C., it can have impact resistance even at a lower temperature.

The urethane resin particles (C) of the present invention can be made into a resin powder composition by adding an additive (N) in addition to the urethane resin (D). The additive (N) is an additive (N1) added before the step of granulating the urethane resin (D) and an additive added after the urethane resin (D) is granulated into urethane resin particles (P). (N2) is present, and additive (N) is used as additive (N1) or additive (N2).
Examples of the additive (N1) include inorganic fillers, pigment particles (E), plasticizers, mold release agents, organic fillers, stabilizers, and dispersants. Examples of the additive (N2) include pigment particles (E). , Plasticizers, mold release agents, organic fillers, antiblocking agents, stabilizers and dispersants.
0-50 are preferable with respect to the weight of (D), and, as for the addition amount (weight%) of an additive (N), More preferably, it is 1-30.

Inorganic fillers are kaolin, talc, silica, titanium oxide, calcium carbonate, bentonite, mica, sericite, glass flake, glass fiber, graphite, magnesium hydroxide, aluminum hydroxide, antimony trioxide, barium sulfate, zinc borate , Alumina, magnesia, wollastonite, zonotlite, whisker, metal powder and the like. Of these, kaolin, talc, silica, titanium oxide and calcium carbonate are preferable from the viewpoint of promoting crystallization of the thermoplastic resin, and kaolin and talc are more preferable.
The volume average particle diameter (μm) of the inorganic filler is preferably from 0.1 to 30, more preferably from 1 to 20, particularly preferably from 5 to 10, from the viewpoint of dispersibility in the thermoplastic resin.

It does not specifically limit as pigment particle (E), A well-known organic pigment and / or an inorganic pigment can be used, (C) 10 weight part or less normally per 100 weight part, Preferably it is 0.01-5 weight Partly formulated. Examples of the organic pigment include insoluble or soluble azo pigments, copper phthalocyanine pigments, quinacridone pigments, and inorganic pigments include chromate, ferrocyan compounds, metal oxides (titanium oxide, iron oxide, Zinc oxide, aluminum oxide, etc.), metal salts [sulfates (barium sulfate, etc.), silicates (calcium silicate, magnesium silicate, etc.), carbonates (calcium carbonate, magnesium carbonate, etc.), phosphates (calcium phosphate, magnesium phosphate, etc.) Etc.], metal powder (aluminum powder, iron powder, nickel powder, copper powder, etc.), carbon black, and the like. Although there is no limitation in particular about the average particle diameter of a pigment, it is 0.05-5.0 micrometers normally, Preferably it is 0.2-1 micrometer.

Examples of plasticizers include phthalate esters (dibutyl phthalate, dioctyl phthalate, dibutylbenzyl phthalate, diisodecyl phthalate, etc.); aliphatic dibasic acid esters (di-2-ethylhexyl adipate, 2-ethylhexyl sebacate, etc.) ); Trimellitic acid ester (trimellitic acid tri-2-ethylhexyl, trimellitic acid trioctyl, etc.); fatty acid ester (butyl oleate, etc.); benzoic acid esters [polyethylene glycol (degree of polymerization 2-10) dibenzoic acid Ester, polypropylene glycol (degree of polymerization 2-10), etc.]; aliphatic phosphate ester (trimethyl phosphate, triethyl phosphate, tributyl phosphate, tri-2-ethylhexyl phosphate and tributoxy phosphate) Aromatic phosphates (triphenyl phosphate, tricresyl phosphate, trixylenyl phosphate, cresyl diphenyl phosphate, xylenyl diphenyl phosphate, 2-ethylhexyl diphenyl phosphate and tris (2,6-dimethylphenyl) phosphate, etc.) A halogen aliphatic phosphate ester (such as tris (chloroethyl) phosphate, tris (β-chloropropyl) phosphate, tris (dichloropropyl) phosphate and tris (tribromoneopentyl) phosphate); and a mixture of two or more of these Can be mentioned.

As the mold release agent, known mold release agents can be used, and fluorine compound type mold release agents (triperfluoroalkyl phosphate (8 to 20 carbon atoms) ester such as triperfluorooctyl phosphate and triperfluorododecyl phosphate). Etc.); silicone compound mold release agents (dimethylpolysiloxane, amino-modified dimethylpolysiloxane, carboxyl-modified dimethylpolysiloxane, etc.), fatty acid ester mold release agents (mono- or polyhydric alcohol esters of fatty acids having 10 to 24 carbon atoms, For example, butyl stearate, hydrogenated castor oil, ethylene glycol monostearate, etc.); aliphatic acid amide type mold release agents (mono- or bisamides of fatty acids having 8 to 24 carbon atoms, such as oleic acid amide, palmitic acid amide, stearic acid) Of amide and ethylenediamine Metal soap (such as magnesium stearate and zinc stearate); natural or synthetic wax (such as paraffin wax, microcrystalline wax, polyethylene wax and polypropylene wax); and mixtures of two or more thereof Is mentioned.

It does not specifically limit as an antiblocking agent, A well-known inorganic type antiblocking agent, an organic type antiblocking agent, etc. can be used. Examples of the inorganic blocking inhibitor include silica, talc, titanium oxide and calcium carbonate. Organic blocking inhibitors include thermosetting resins with a particle size of 10 μm or less (thermosetting polyurethane resins, guanamine resins, epoxy resins, etc.) and thermoplastic resins with a particle size of 10 μm or less (thermoplastic polyurethane urea resin and poly ( (Meth) acrylate resin, etc.).

A stabilizer is a carbon-carbon double bond (such as an ethylene bond which may have a substituent) in the molecule (excluding a double bond in an aromatic ring), a carbon-carbon triple bond (with a substituent). A compound having an acetylene bond which may be present can be used, and an ester (ethylene glycol di (meth) acrylate) of (meth) acrylic acid and a polyhydric alcohol (2 to 10 valent polyhydric alcohol, the same applies hereinafter). , Trimethylolpropane tri (meth) acrylate, pentaerythritol tetra (meth) acrylate and dipentaerythritol tri (meth) acrylate); esters of (meth) allyl alcohol and divalent to hexavalent polycarboxylic acids (diallyl phthalate) And trimellitic acid triallyl ester); poly (meth) allyl ether of polyhydric alcohol (pentaerythritol) Poly (meth) allyl ether, etc.); polyhydric alcohol polyvinyl ether (ethylene glycol divinyl ether, etc.); polyhydric alcohol polypropenyl ether (ethylene glycol dipropenyl ether, etc.); polyvinyl benzene (divinyl benzene, etc.) and their 2 A mixture of seeds or more may be mentioned. Among these, from the viewpoint of stability (radical polymerization rate), an ester of (meth) acrylic acid and a polyhydric alcohol is preferable, and trimethylolpropane tri (meth) acrylate, pentaerythritol tetra (meth) acrylate and more preferably Dipentaerythritol penta (meth) acrylate.

As a mixing device used when the additive (N2) is added to and mixed with the urethane resin particles (C), a known powder mixing device can be used, and a container rotating type mixer, a fixed container type mixer, and a fluid motion A type mixer can be used. Among these mixing devices, a fixed container type mixer is preferable, and a high-speed flow type mixer, a double-shaft paddle type mixer, a high-speed shear mixing device (Hensiel mixer (registered trademark), etc.), a low-speed mixing device ( Planetary mixers, etc.) and conical screw mixers (Nauta mixer (registered trademark), etc.), more preferably double-shaft paddle type mixers, low speed mixing devices (planetary mixers, etc.) and conical screw mixers (Nauta mixer (registered trademark)) , The following is omitted)). The mixing is preferably dry blended.

Examples of the urethane resin (D) in the present invention include aliphatic diisocyanate (a1), monool (a2), high molecular diol (a3) having a number average molecular weight of 500 to 10,000, and optionally low molecular diol (a4). And those obtained by reacting an alicyclic diamine and / or an aliphatic diamine (b) with the isocyanate group-terminated urethane prepolymer (a) derived from

As the aliphatic diisocyanate (a1) constituting the above (a), (i) an aliphatic diisocyanate having 2 to 18 carbon atoms (excluding carbon in the NCO group, the same shall apply hereinafter) [ethylene diisocyanate, tetramethylene diisocyanate, hexa Methylene diisocyanate (HDI), dodecamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, lysine diisocyanate, 2,6-diisocyanatomethyl caproate, bis (2-isocyanatoethyl) fumarate, bis (2-isocyanate) Natoethyl) carbonate, 2-isocyanatoethyl-2,6-diisocyanatohexanoate, etc.]; (ii) alicyclic diisocyanate having 4 to 15 carbon atoms [isophorone diisocyanate (IPDI), dicyclohexylmethane-4,4 ' Diisocyanate (hydrogenated MDI), cyclohexylene diisocyanate, methylcyclohexylene diisocyanate (hydrogenated TDI), bis (2-isocyanatoethyl) -4-cyclohexene, etc.]; (iii) an aromatic aliphatic group having 8 to 15 carbon atoms Diisocyanates [m- and / or p-xylylene diisocyanate (XDI), α, α, α ′, α′-tetramethylxylylene diisocyanate (TMXDI), etc.]; (iv) modified products of these diisocyanates (carbodiimide groups, A diisocyanate-modified product having a uretdione group, a uretoimine group, a urea group, etc.); and a mixture of two or more of these. Of these, preferred are aliphatic diisocyanates or alicyclic diisocyanates, and particularly preferred are HDI, IPDI, and hydrogenated MDI.

Examples of the monool (a2) include aliphatic monools having 1 to 8 carbon atoms [linear monool (methanol, ethanol, propanol, butanol, pentanol, hexanol, octanol, etc.), monool having a branched chain ( Isopropyl alcohol, neopentyl alcohol, 3-methyl-pentanol, 2-ethylhexanol, etc.]; monools having a cyclic group having 6 to 10 carbon atoms [alicyclic group-containing monools (cyclohexanol, etc.), aromatic rings Containing monools (such as benzyl alcohol)] and mixtures of two or more thereof. Of these, preferred are aliphatic monools. Examples of the polymer monool include polyester monool, polyether monool, polyether ester monool, and a mixture of two or more thereof.

Examples of the polymer diol (a3) having a number average molecular weight of 500 to 10,000 include polyester diol, polyether diol, polyether ester diol, and a mixture of two or more thereof. Examples of the polyester diol include (i) a low molecular diol and a dicarboxylic acid or an ester-forming derivative thereof [an acid anhydride, a lower alkyl (carbon number 1 to 4) ester, an acid halide, etc.] or a dialkyl carbonate (carbon number of an alkyl group). 1 to 4) by condensation polymerization; (ii) ring-opening polymerization of a lactone monomer using a low molecular diol as an initiator; (iii) a dicarboxylic acid anhydride and an alkylene oxide are reacted using a low molecular diol as an initiator. And mixtures of two or more thereof.

Specific examples of the low molecular diol of (i), (ii) or (iii) above include aliphatic diols having 2 to 8 carbon atoms [linear diols (ethylene glycol, diethylene glycol, 1,3-propanediol, 1, 4-butanediol, 1,5-pentanediol, 1,6-hexanediol, etc.), branched diols (propylene glycol, neopentyl glycol, 3-methyl-1,5-pentanediol, 2,2-diethyl) -1,3-propanediol, 1,2-, 1,3- or 2,3-butanediol, etc.]]; diols having a cyclic group [an alicyclic group-containing diol having 6 to 15 carbon atoms [1, 4-bis (hydroxymethyl) cyclohexane, hydrogenated bisphenol A and the like], aromatic ring-containing diol having 8 to 20 carbon atoms (m- or p Xylylene glycol, etc.), oxyalkylene ethers of bisphenols (bisphenol A, bisphenol S, bisphenol F, etc.), oxyalkylene ethers of polynuclear phenols (dihydroxynaphthalene, etc.), bis (2-hydroxyethyl) terephthalate, etc.]; Examples include alkylene oxide adducts (molecular weight less than 500) and mixtures of two or more thereof. Among the low molecular diols, preferred are aliphatic diols and alicyclic group-containing diols.

As the alkylene oxide, ethylene oxide (EO), propylene oxide (PO), 1,2-, 1,3-, 1,4- or 2,3-butylene oxide, styrene oxide, carbon number 5-10 or More α-olefin oxide, epichlorohydrin and combinations of two or more of these (block or random addition) can be mentioned.

Specific examples of the dicarboxylic acid or the ester-forming derivative thereof (i) include aliphatic dicarboxylic acids having 4 to 15 carbon atoms [succinic acid, adipic acid, sebacic acid, glutaric acid, azelaic acid, maleic acid, fumaric acid. Etc.], aromatic dicarboxylic acids having 8 to 12 carbon atoms [terephthalic acid, isophthalic acid, etc.], ester-forming derivatives thereof [acid anhydrides (phthalic anhydride, maleic anhydride, etc.), lower alkyl esters (dimethyl esters, Diethyl ester, etc.), acid halide (acid chloride, etc.) and the like, and mixtures of two or more thereof.

Examples of the lactone monomer (ii) include lactones having 4 to 12 carbon atoms, such as γ-butyrolactone, γ-valerolactone, ε-caprolactone, and mixtures of two or more thereof.

The polyether diol is a polyether diol obtained by dehydration reaction of two hydroxyl group-containing compounds (for example, the low molecular diol, divalent phenols, etc.), and a structure in which an alkylene oxide is added to the two hydroxyl group-containing compounds. These compounds are mentioned. Examples of the divalent phenols include bisphenols [bisphenol A, bisphenol F, bisphenol S, etc.], monocyclic phenols [catechol, hydroquinone, etc.], and the like.
Among these, preferred are polytetramethylene glycol and dihydric phenols to which alkylene oxide is added, and more preferred are those obtained by adding EO to dihydric phenols.

Further, as the polyether ester diol, the polyester diol in which the polyether diol is used instead of the low molecular diol of the raw material, for example, one or more of the polyether diol and the dicarboxylic acid exemplified as the raw material of the polyester diol Or what is obtained by polycondensation with 1 or more types of the ester-forming derivative is mentioned. Among these polymer diols (a3), preferred are polyester diols, and more preferred are polycondensates of low-molecular diols and dicarboxylic acids.

As the low molecular diol (a4) used together with the above (a2) and (a3) as needed, the low molecular diol exemplified as the starting material for the above-mentioned poester diol can be used. Preferred as (a4) is an aliphatic diol. The amount of (a4) used is usually 20% by weight or less, preferably 10% by weight or less, based on the weight of (a3).

The reaction temperature for producing the isocyanate group-terminated urethane prepolymer (a) may be the same as that usually employed for urethanization, and is usually 20 ° C to 100 ° C when a solvent is used. When not used, it is usually 20 ° C to 220 ° C, preferably 80 ° C to 200 ° C. In the prepolymerization reaction, a catalyst usually used for polyurethane can be used if necessary to accelerate the reaction. Examples of the catalyst include amine-based catalysts [triethylamine, N-ethylmorpholine, triethylenediamine, etc.], tin-based catalysts [trimethyltin laurate, dibutyltin dilaurate, dibutyltin malate, etc.].
When (a) is produced, by using (a1) so as to be an excess mole of isocyanate groups with respect to the total moles of terminal hydroxyl groups of (a2), (a3) and (a4), the isocyanate group ends can be obtained. can do.

Among the alicyclic diamine and / or the aliphatic diamine (b) used for the reaction with (a), the alicyclic diamine includes an alicyclic diamine having 6 to 18 carbon atoms [4,4′-diamino-3. , 3′-dimethyldicyclohexylmethane, 4,4′-diaminodicyclohexylmethane, diaminocyclohexane, isophoronediamine, etc.]; As the aliphatic diamine, an aliphatic diamine having 2 to 12 carbon atoms [ethylenediamine, propylenediamine, hexamethylenediamine, etc. And C8-15 aromatic aliphatic diamines [xylylenediamine, α, α, α ′, α′-tetramethylxylylenediamine, etc.], and the above compound is one kind or two or more kinds thereof. Can be used as a mixture of Of these, preferred are isophorone diamine and hexamethylene diamine.

As a method for producing the urethane resin particles (C) of the present invention, a granulation method in which crushing action is simultaneously applied is used. By using the granulation method, it is possible to produce a urethane resin having irregularities on the surface and having a shape factor SF2 of 120 to 240, and by simultaneously adding a crushing action, 90% particle diameter / 10% particle diameter. Particles having a sharp particle size distribution of 2.0 to 3.0 can be obtained.
Examples of the method for producing such urethane resin particles (C) include the following methods.

There is a method of obtaining the urethane resin particles (C) of the present invention by synthesizing the primary particles (p1) containing the urethane resin (D) as a main component, drying them as necessary, and then granulating them.

In this case, the primary particles (p1) have a particle size of 0.3 to 50 μm, preferably 1 to 30 μm, and more preferably 3 to 10 μm. Moreover, as a method of granulating, primary particles (p1) are heat-fused on the surface and granulated, a binder component is added to the primary particles (p1), and primary particles (p1) are added by a binder. The method of bonding and granulating each other is mentioned.

As a manufacturing method of primary particles (p1),
(I) An organic solvent solution of urethane resin (D) or a precursor (d0) of urethane resin (D) or an organic solvent solution thereof, a dispersion stabilizer, an aqueous dispersion containing a surfactant, or a dispersion stabilizer In the case of the precursor (d0) after being dispersed in an organic solvent in which the urethane resin (D) or its precursor (d0) is not dissolved, the polymer is polymerized, and then this is solid-liquid separated and dried. How to get.
(Ii) A method of obtaining a lump or pellet resin of urethane resin (D) and then powdering it. When the precursor (d0) is used, it becomes a urethane resin (D) after primary particle formation. The particleizer is not particularly limited as long as it is generally commercially available as an emulsifier or a disperser. For example, a homogenizer (manufactured by IKA), polytron (manufactured by Kinematica), TK auto homomixer (manufactured by Primics) ) Etc. batch type emulsifier, Ebara milder (manufactured by Ebara Seisakusho), TK fill mix, TK pipeline homomixer (manufactured by Primics), colloid mill (manufactured by Shinko Pantech), thrasher, trigonal wet pulverizer (Mitsui Miike Kako Co., Ltd.), Capitolon (Eurotech Co., Ltd.), Fine Flow Mill (Pacific Kiko Co., Ltd.) and other continuous emulsifiers, Microfluidizer (Mizuho Kogyo Co., Ltd.), Nanomizer (Nanomizer Co., Ltd.), High-pressure emulsifier such as APV Gaurin (manufactured by Gaurin), membrane milk such as membrane emulsifier (manufactured by Chilling Industries) Machine, Vibro Mixer (Hiyaka Kogyo) vibrating emulsifier such as, ultrasonic emulsifier such as an ultrasonic homogenizer (manufactured by Branson Co., Ltd.). Among these, preferred from the viewpoint of particle size distribution are APV Gaurin, homogenizer, TK auto homomixer, Ebara milder, TK fill mix, and TK pipeline homomixer.

As a solid-liquid separation method, a known centrifugal separation, belt press, filter press, or the like can be applied.
Furthermore, primary particles (p1) can be obtained by drying by a known method.
As a granulation apparatus used when the obtained primary particles (p1) are made into urethane resin particles (C) by granulation, a granulation apparatus in which a crushing action is simultaneously applied among known granulation apparatuses. If it is, it will not be specifically limited. For example, kneaders, paddle mixers, ribbon mixers, disk dryers, Henschel mixers (made by Mitsui Miike Chemical), Nauter mixers (made by Hosokawa Micron), TURBO SPHERE mixers (made by Sumitomo Heavy Industries), ribbon blenders (made by Hosokawa Micron), tar Examples include a bulletizer (manufactured by Hosokawa Micron), solid air (manufactured by Hosokawa Micron), a planetary mixer, a universal mixer, a high-speed mixer, and the like. As temperature in the granulation tank in the case of implementing the manufacturing method which concerns on this invention, 0-200 degreeC, Preferably 70-150 degreeC is preferable.

The method for producing the bulk or pellet urethane resin (D) can be obtained, for example, by a batch type kneader such as a kneader or a screw type extruder equipped with a side feeder. The lump or pellet thermoplastic polyurethane is cooled by liquid nitrogen and pulverized using an impact type pulverizer such as a turbo mill, pin mill, hammer mill, etc., to obtain primary particles (p1).

Using the above granulator, granulation by heat fusion of the primary particle (p1) surface, adhesion granulation by adding a binder, and swelling and fusion of the primary particle (p1) surface by an organic solvent. There is a granulation method. Examples of the binder used in this case include the plasticizers mentioned in the description of the additive. Moreover, as an organic solvent, the well-known thing with affinity with a urethane resin (D) is mentioned.

As another method, an organic solvent solution of the urethane resin (D) or a precursor (d0) of the urethane resin (D) or an organic solvent solution thereof is used as an aqueous dispersion containing a dispersion stabilizer, a surfactant, or dispersion stability. After granulating into primary particles (p2) in an organic solvent that does not dissolve the urethane resin (D) or its precursor (d0) containing the agent, the particles (p2) are aggregated in the dispersion and granulated. To obtain a dispersion slurry of urethane resin particles (C). In this case, the primary particles have a particle size of 0.3 to 50 μm, preferably 1 to 30 μm, more preferably 3 to 10 μm. It is. As a method of agglomerating particles, an organic solvent, salt, acid, base, or the like that lowers the dispersion stability of the primary particles (p2) is added to the aqueous dispersion in advance. Examples thereof include a method of adding an organic solvent, salt, acid or base, a method of using a dispersant having low dispersion stability, and a method of reducing the concentration of the dispersant. When the precursor (d0) is used, it becomes urethane resin (D) after granulation. In this case, as the particleizing apparatus, the same one as described above can be used, and the solid-liquid separation and drying steps can also be performed by the same method as described above.

Among these methods, a method is preferred in which the primary particles that can be formed in three steps of granulation, solid-liquid separation, and drying of the urethane resin particles (C) are granulated in a dispersion. The formation of the concavo-convex shape by granulation exemplified above is a build-up type process in which the concavo-convex shape is formed by a combination of particles smaller than the final particle size. In addition to this, the method for forming irregularities also includes a method for forming irregularities by physically scraping or chemically treating particles on a smooth surface. It is disadvantageous in that it is necessary to remove the abrasive after shaving and the debris of the shaved particles, and that chemical treatment requires post-treatment of the chemical solution. Also, from the viewpoint of resources, a part to be scraped off and a part to be dissolved by chemical treatment are generated, so that the process is wasteful. Therefore, it can be said that a method of forming irregularities on the particle surface by granulation of primary particles is preferable.

The urethane resin particles (C) of the present invention are preferably used together with the pigment particles (E), and when the colored urethane resin is produced, the effect can be exhibited most.
That is, by mixing urethane resin particles (C) and pigment particles (E), a urethane resin particle composition in which (E) adheres to the surface of (C) can be obtained. In this urethane resin particle composition, most of the mixed (E) adheres to the surface of (C), particularly the indented portion, so there is almost no aggregation of pigment particles, and per 100 urethane resin particles (C). The particle size is 20 to 140 μm, and the number of particles (F) that are aggregates of pigment particles (E) is 1 or less.

The urethane resin particle composition of the present invention contains not more than one particle (F) that is an aggregate of pigment particles (E) with a particle size of 20 to 140 μm per 100 urethane resin particles (C). Is desirable. The particles (F) are not limited to those produced by sliding or agglomerating the pigment particles (E) from the surface of the urethane resin particles (C), but the stage before mixing with the urethane resin particles (C), that is, coloring. Those already agglomerated at the time, such as agent paste, pigment powder, and the like are also included. If the number of particles (F) is 1 or less per 100 urethane resin particles (C), the pigment color is good, so the color of the urethane resin particles (C) itself or the color developed when melt-molded. Is preferable because the amount of pigment used is small.

The resin powder composition of the present invention can be molded into a resin molded body. The resin powder composition of the present invention is suitable for slush molding.
When the resin powder composition of the present invention is applied for slush molding, the volume average particle diameter of the resin powder composition is 1 to 700 μm, preferably 10 to 500 μm, more preferably 50 to 300 μm. For slush molding, the box containing the resin powder composition of the present invention and a heated mold are both vibrated and rotated, the resin powder composition is melted and flowed in the mold, cooled and solidified, and molded. A method for producing a body (skin etc.) can be applied.
The mold temperature (° C.) is preferably 200 to 280 ° C.

The resin molding obtained by slush molding the resin powder composition of the present invention is suitable as an automobile interior material (instrument panel, door trim, etc.). For example, the thickness of the resin molded body (skin) molded with the resin powder composition of the present invention is preferably 0.3 to 1.2 mm. The molded body (skin) can be made into a resin molded product by setting the surface so as to be in contact with the foaming mold, pouring urethane foam, and forming a foam layer of 5 mm to 15 mm on the back surface.

In the case of a smooth surface with no irregularities on the surface, the generation of particles (F) that are aggregates of pigment particles (E) is remarkable, but the urethane resin particles (C) of the present invention have irregularities on the particle surface. Therefore, the pigment particles attached to the surface of the resin particles do not slide off from the surface or aggregate between the pigment particles on the particle surface due to the shear at the time of stirring and mixing in the coloring step or the subsequent step. Therefore, the color developability is good, and the problem that particles (F) that are aggregates of pigments are mixed in the product does not occur. Further, compared with a process of mixing with a pigment at the stage of a liquid raw material before particle formation, it is not necessary to carefully clean the production equipment for each color change of the product, so that productivity can be improved.

As a specific method of mixing the urethane resin particles (C) and the pigment particles (E) and attaching the pigment particles (E) to the surfaces of the urethane resin particles (C), for example, the melting point is 0 ° C. or less and the boiling point A method of mixing a pigment dispersion (G) in which pigment particles (E) are dispersed in an organic compound (H) containing at least one ester group in a molecule having a temperature of 170 ° C. or higher and urethane resin particles (C) Is preferred. By performing this method, the urethane resin particles (C) can be colored efficiently and with good color reproducibility.

Since the organic compound (H) has good dispersion stability of the pigment particles (E), the pigment dispersion (G) can store the pigment (E) for a long time without causing aggregation of the pigment. . In addition, the pigment dispersion (G) composed of the organic compound (H) and the pigment particles (E) has a high affinity with the urethane resin particles (C). Therefore, only the pigment particles (E) are used as urethane resin particles (C). ) On the particle surface in a short time and uniformly.

Examples of the organic compound (H) include the same compounds as those exemplified as the plasticizer. Of these, preferred are benzoates, and particularly preferred is a dibenzoate of polyethylene glycol.

EXAMPLES Hereinafter, although an Example demonstrates this invention further more concretely, this invention is not limited to this. In the following, parts indicate parts by weight, and% indicates% by weight.

Production Example 1
Production of prepolymer solution A reaction vessel equipped with a thermometer, a stirrer and a nitrogen blowing tube was charged with polybutylene adipate (575 parts) having a number average molecular weight (hereinafter referred to as Mn) of 1000 and polyhexamethylene having a Mn of 900. After adding isophthalate (383 parts) and 1-octanol (16.8 parts) and purging with nitrogen, the mixture was heated to 110 ° C. with stirring and melted, and cooled to 60 ° C. Subsequently, hexamethylene diisocyanate (242 parts) was added and reacted at 85 ° C. for 6 hours. Next, after cooling to 60 ° C., tetrahydrofuran (217 parts) and stabilizer (2.5 parts) [Irganox 1010 manufactured by Ciba Specialty Chemicals Co., Ltd.] were added and mixed uniformly to obtain a prepolymer solution. Obtained. The obtained prepolymer solution had an NCO content of 2.2%.

Production Example 2
Production of MEK ketimine product of diamine Hexamethylenediamine and excess MEK (methyl ethyl ketone; 4-fold molar amount with respect to diamine) were refluxed at 80 ° C. for 24 hours, and the generated water was removed from the system. Thereafter, unreacted MEK was removed under reduced pressure to obtain a MEK ketiminate.

Production Example 3
Production of prepolymer solution A reaction vessel equipped with a thermometer, a stirrer and a nitrogen blowing tube was charged with polybutylene adipate (1214 parts) having a number average molecular weight (hereinafter referred to as Mn) of 1000 and polyethylene phthalate having a Mn of 900 ( Terephthalic acid / isophthalic acid = 50/50 (weight ratio)) (304 parts), 1-octanol (27.6 parts) were charged, and the atmosphere was purged with nitrogen. Until cooled. Subsequently, hexamethylene diisocyanate (313.2 parts) was added and reacted at 85 ° C. for 6 hours. Next, after cooling to 60 ° C., tetrahydrofuran (425 parts) and a stabilizer (2.7 parts) [Irganox 1010 manufactured by Ciba Specialty Chemicals Co., Ltd.] were added and mixed uniformly to prepare a prepolymer solution. Obtained. The NCO content of the obtained prepolymer solution was 1.6%.

Example 1
Production reaction vessel of urethane resin particles (C-1) The prepolymer solution (100 parts) obtained in Production Example 1 and the MEK ketimine compound (5.6 parts) are charged and mixed, and the dispersant (Sanyo Chemical Industries) is mixed there. 340 parts of an aqueous solution in which Sunspear PS-8 (1.3 parts) manufactured by Co., Ltd.) and tetrahydrofuran (68 parts) are dissolved, is added for 1 minute at a rotational speed of 10,000 rpm using an ultradisperser manufactured by Yamato Scientific Co., Ltd. Mixed. This mixture was transferred to a reaction vessel equipped with a thermometer, a stirrer and a nitrogen blowing tube, purged with nitrogen, and then reacted at 50 ° C. for 10 hours with stirring. After completion of the reaction, filtration and drying were performed to produce urethane resin particles (C-1). Mn of (C-1) was 25,000, the volume average particle diameter was 151 μm, and the 90% particle diameter / 10% particle diameter was 2.7.
100 parts of the obtained urethane resin particles (C-1), 1.0 part of carbon black as a coloring agent, 1.0 part of dibenzoic acid ester of polyethylene glycol (degree of polymerization 2 to 10) (manufactured by Sanyo Chemical Industries) Pigment dispersion (G-1) (2.7 parts) dispersed in an organic compound (H-1) that is Sunsoft EB300, melting point: 0 ° C. or lower, boiling point: 300 ° C. or higher) is charged into a Henschel mixer. And stirred for 1 minute at a rotational speed of 700 min ⁻¹ . Subsequently, the urethane resin particle composition was colored by continuously classifying with a mesh of 850 μm and 45 μm mesh.

Example 2
Production of urethane resin particles (C-2) Urethane resin particles (C-2) were produced by the same operation as in Example 1 except that 15 parts of sodium chloride was added to the aqueous solution instead of tetrahydrofuran. Mn of (C-2) was 25,000, the volume average particle size was 170 μm, and the 90% particle size / 10% particle size was 3.0.
100 parts of the obtained urethane resin particles (C-2) and the pigment dispersion (G-1) (2.7 parts) as a colorant were put into a Henschel mixer and stirred for 1 minute at a rotation speed of 700 min ⁻¹ . . Subsequently, the urethane resin particle composition was colored by continuously classifying with a mesh of 850 μm and 45 μm mesh.

Example 3
Production of urethane resin particles (C-3) In a reaction vessel, the oil phase in which the prepolymer solution (100 parts) obtained in Production Example 1 and the MEK ketimine compound (5.6 parts) were added and mixed, and the dispersant polyvinyl alcohol ( (Kuraray Co., Ltd.) (5.3 parts)) dissolved solution was fed to the TK pipeline homomixer (Primics Co., Ltd.) at 4000 rpm at flow rates of 100 kg / hr and 400 kg / hr, respectively. , Distributed. This mixture was transferred to a reaction vessel equipped with a thermometer, a stirrer and a nitrogen blowing tube, purged with nitrogen, and then reacted at 50 ° C. for 10 hours with stirring. After completion of the reaction, filtration and drying were performed to produce urethane fine particles (c-3). The volume average particle diameter of the fine particles (c-3) was 20 μm. Fine particles (c-3) were granulated by placing in a Henschel mixer (Mitsui Miike Chemical Co., Ltd.) and stirring at 40 m / sec. The temperature reached 140 ° C. 15 minutes after the start of stirring, and the operation was stopped at this stage to obtain urethane resin particles (C-3). Mn of (C-3) was 25,000, the volume average particle size was 180 μm, and the 90% particle size / 10% particle size was 2.9.
100 parts of the obtained urethane resin particles (C-3) and the pigment dispersion (G-1) (2.7 parts) as a colorant were put into a Henschel mixer and stirred at a rotation speed of 700 min ⁻¹ for 1 minute. . Subsequently, the urethane resin particle composition was colored by continuously classifying with a mesh of 850 μm and 45 μm mesh.

Example 4
Production of Urethane Resin Particles (C-4) Except that the operation time of the Henschel mixer was changed to 25 minutes, the same operation as in Example 3 was carried out, and classification was performed continuously with a mesh screen of 850 μm and 350 μm. Particles (C-4) were obtained. Mn of (C-4) was 25,000, the volume average particle size was 500 μm, and the 90% particle size / 10% particle size was 3.0.
100 parts of the obtained urethane resin particles (C-4) and the pigment dispersion (G-1) (2.7 parts) as a colorant were put into a Henschel mixer and stirred for 1 minute at a rotation speed of 700 min ⁻¹ . . Subsequently, the urethane resin particle composition was colored by continuously classifying with a mesh of 850 μm and 45 μm mesh. The obtained urethane resin had a 90% particle diameter / 10% particle diameter of 3.0.

Example 5
Production reaction vessel of urethane resin particles (C-5) The prepolymer solution (100 parts) obtained in Production Example 3 and the MEK ketimine compound (4.1 parts) were charged and mixed, and a dispersant (SANYO KASEI KOGYO) Sanspear PS-8 (1.3 parts) manufactured by Co., Ltd.) and 340 parts of an aqueous solution in which methyl ethyl ketone (68 parts) is dissolved are added, and 1 minute at a rotational speed of 9000 rpm using an ultradisperser manufactured by Yamato Scientific Co., Ltd. Mixed. This mixture was transferred to a reaction vessel equipped with a thermometer, a stirrer and a nitrogen blowing tube, purged with nitrogen, and then reacted at 50 ° C. for 10 hours with stirring. After completion of the reaction, filtration and drying were performed to produce urethane resin particles (C-5). Mn of (C-5) was 18,000, the volume average particle size was 143 μm, and the 90% particle size / 10% particle size was 2.8.
100 parts of the obtained urethane resin particles (C-5) and the pigment dispersion (G-1) (2.7 parts) as a colorant were put into a Henschel mixer and stirred at a rotational speed of 700 min ⁻¹ for 1 minute. . Subsequently, the urethane resin particle composition was colored by continuously classifying with a mesh of 850 μm and 45 μm mesh.

Example 6
Production phase of urethane resin particles (C-6) An oil phase in which the prepolymer solution (100 parts) obtained in Production Example 1 and the MEK ketimine compound (5.6 parts) were added and mixed in a reaction vessel, and a dispersant (dodecyl diphenyl ether) Dispersing an aqueous solution in which sodium disulfonate (5.3 parts) was dissolved at a flow rate of 100 kg / hr and 400 kg / hr, respectively, while operating DISPAX-REACTOR (manufactured by IKA) at 12000 rpm Went. This mixture was transferred to a reaction vessel equipped with a thermometer, a stirrer and a nitrogen blowing tube, purged with nitrogen, and then reacted at 50 ° C. for 10 hours with stirring. After completion of the reaction, filtration and drying were performed to produce urethane primary particles (p-6). The volume average particle diameter of the primary particles (p-6) was 3 μm. Primary particles (p-6) were granulated by placing in a Henschel mixer (Mitsui Miike Chemical Co., Ltd.) and stirring at 40 m / sec. 15 minutes after the start of stirring, the temperature reached 140 ° C., the operation was continued for 15 minutes, the system was stopped after the operation, and the mixture was continuously classified with a mesh of 425 μm and 250 μm to obtain urethane resin particles (C-6). Mn of (C-6) was 25,000, the volume average particle size was 350 μm, and the 90% particle size / 10% particle size was 2.7.
100 parts of the obtained urethane resin particles (C-6) and the pigment dispersion (G-1) (2.7 parts) as a colorant were put into a Henschel mixer and stirred at a rotation speed of 700 min ⁻¹ for 1 minute. . Subsequently, the urethane resin particle composition was colored by continuously classifying with a mesh of 850 μm and 45 μm mesh.

Example 7
Production reaction vessel of urethane resin particles (C-7) The prepolymer solution (100 parts) obtained in Production Example 3 and the MEK ketimine compound (4.1 parts) were introduced and mixed, and the dispersant (Sanyo Chemical Industries) was mixed there. 300 parts of an aqueous solution in which SunSpear PS-8 (1.3 parts) manufactured by Co., Ltd. was dissolved was added and mixed for 1 minute at a rotation speed of 6000 rpm using an Ultra Disperser manufactured by Yamato Scientific Co., Ltd. This mixture was transferred to a reaction vessel equipped with a thermometer, a stirrer and a nitrogen blowing tube, purged with nitrogen, and then reacted at 50 ° C. for 10 hours with stirring. After completion of the reaction, filtration and drying were performed to produce primary particles (p-7) of urethane resin.
The volume average particle diameter of the primary particles (p-7) of this urethane resin was 40 μm. Primary particles (p-7) were granulated by putting in a Henschel mixer (Mitsui Miike Chemical Co., Ltd.) and stirring at 40 m / sec. The operation was stopped when the temperature reached 140 ° C. 15 minutes after the start of stirring, passed through a 48-mesh sieve, and further passed through a 425-mesh sieve to obtain urethane resin particles (C-7). Mn of (C-7) was 25,000, the volume average particle size was 110 μm, and the 90% particle size / 10% particle size was 2.7.
100 parts of the obtained urethane resin particles (C-7) and the pigment dispersion (G-1) (2.7 parts) as a colorant were put into a Henschel mixer and stirred at a rotation speed of 700 min ⁻¹ for 1 minute. . Subsequently, the urethane resin particle composition was colored by continuously classifying with a mesh of 850 μm and 45 μm mesh.

Example 8
Production of urethane resin particles (C-8) Primary particles of urethane by performing the same operation as in Example 6 except that the amount of dispersant (sodium dodecyl diphenyl ether disulfonate) is changed to 7.5 parts. (P-8) was produced. The central particle diameter of the primary particles (p-8) was 2 μm. Furthermore, by performing the same operations as in Example 7, urethane resin particles (C-8) were obtained. Mn of (C-8) was 25,000, the center particle size was 250 μm, and the 90% particle size / 10% particle size was 3.0.
100 parts of the obtained urethane resin particles (C-8) and the pigment dispersion (G-1) (2.7 parts) as a colorant were put into a Henschel mixer and stirred at a rotation speed of 700 min ⁻¹ for 1 minute. . Subsequently, the urethane resin particle composition was colored by continuously classifying with a mesh of 850 μm and 45 μm mesh.

Example 9
Production of Urethane Resin Particles (C-9) By changing the amount of tetrahydrofuran used to 34 parts (amount of organic solvent in aqueous solution: 10% by weight), the same procedure as in Example 1 was carried out to obtain urethane resin particles (C-9). -9) was obtained. Mn of (C-9) was 25,000, the center particle size was 120 μm, and the 90% particle size / 10% particle size was 2.0.
100 parts of the obtained urethane resin particles (C-9) and the pigment dispersion (G-1) (2.7 parts) as a colorant were put into a Henschel mixer and stirred at a rotation speed of 700 min ⁻¹ for 1 minute. . Subsequently, the urethane resin particle composition was colored by continuously classifying with a mesh of 850 μm and 45 μm mesh.

Comparative Example 1
Production of urethane resin particles (C′-1) <Synthesis of thermoplastic polyurethane resin>
In a reaction vessel equipped with a nitrogen introduction tube, a thermometer, a cooling tube and a stirrer, 75.2 parts Takelac U-2024 (Mitsui Chemical Polyurethane, Polyester Polyol) as a polyol and Irganox 245 (Ciba Specialty) as an antioxidant Chemicals) 0.05 parts, monool 2-ethylhexyl alcohol (Wako Pure Chemical Industries, Ltd.) 0.49 parts, isocyanate 4,4'-methylenebis (cyclohexyl isocyanate) (Sumika Bayer Urethane Co., Ltd.) , Trade name: Death Module W) 21.6 parts was charged, the temperature was raised to 80-85 ° C. with good stirring, and the reaction was continued for about 3.5 hours, after which the NCO wt% was 3.6 wt%. It was confirmed that it was lowered to an isocyanate group-terminated prepolymer.
Thereafter, 0.45 part of the dispersion stabilizer (I) and 29.2 parts of n-heptane, which had been mixed in advance, were charged all at once into the reaction vessel, and the isocyanate group-terminated prepolymer was dispersed over 1 hour. .

Then, 58.4 parts of n-heptane was charged at a rate of 30 ml / min, and then the reaction temperature was lowered to 25 ° C. A chain extender prepared by previously dispersing 2.7 parts of a 70% by weight aqueous solution of 1,6-hexamethylenediamine in 0.06 part of dispersion stabilizer (I) and 3.86 parts of n-heptane. The dispersion was charged all at once.
After completion of the charging, the reaction was carried out at 25 to 35 ° C. for 30 minutes, then the temperature was raised to 45 ° C., then the reaction was continued for 30 minutes at the same temperature, and finally the reaction temperature was raised to 80 to 85 ° C. By reacting for a time, a dispersion of a thermoplastic polyurethane resin was obtained.
After mixing so that styrene and methyl methacrylate become 60% by weight and 40% by weight, respectively, α-methylstyrene dimer that becomes 0.5 parts is added to 100 parts of these monomers, and further mixed uniformly. And 100 parts by weight of the total monomer (total amount of styrene and methyl methacrylate), dimethyl 2,2′-azobis (2-methylpropionate) (trade name, manufactured by Wako Pure Chemical Industries, Ltd.) as a radical polymerization initiator. : V-601) was added to prepare a monomer solution.
The monomer liquid was charged all together at a reaction temperature of 30 ° C. into the dispersion of the thermoplastic polyurethane resin obtained above so that the total amount of the monomer was 20 parts by weight with respect to 100 parts by weight of the thermoplastic polyurethane resin. . Thereafter, the temperature was gradually raised, and finally, an aging reaction was performed at a reaction temperature of 80 ° C. for 12 hours.
Thereafter, 0.5 parts of TINUVIN 213 (manufactured by Ciba Specialty Chemicals) as a benzotriazole-based ultraviolet absorber and 0.5 part of TINUVIN 765 (manufactured by Ciba Specialty Chemicals) as a hindered amine light-resistant stabilizer were added to 100 parts of a thermoplastic polyurethane resin. 5 parts, 6 parts of a mixture of dipentaerythritol hexaacrylate and dipentaerythritol pentaacrylate (trade name: Kayarad DPHA, manufactured by Nippon Kayaku Co., Ltd.) as a heat-crosslinkable monomer, p-methoxyphenol as a polymerization inhibitor, heat-crosslinkable The thermoplastic polyurethane resin dispersion was charged so as to be 1 part with respect to 100 parts of the monomer and mixed for 30 minutes.

Subsequently, the dispersion was cooled to 30 ° C. or lower, and a solid content was collected by filtration.
Next, 100 parts of a solid content, 0.5 part of TSF-451-3000 (GE Toshiba Silicone Silicone Oil) and 0.3 part of an antiblocking agent are charged into a Nauter mixer dryer. The mixture was dried at 40 ° C. for 3 hours with stirring under reduced pressure. Thereafter, the contents were cooled to 25 ° C. or lower, then discharged, and classified continuously with a mesh of 425 μm and 75 μm openings to obtain a particulate polyurethane resin composition.
100 parts of the obtained particulate polyurethane resin composition, 0.6 parts of carbon black / calcium carbonate dispersion (manufactured by Sumika Color Co., Ltd., trade name: PV-817) and 0.4 parts of carbon black / A calcium carbonate dispersion (manufactured by Sumika Color Co., Ltd., trade name: PV-801) was put into a Henschel mixer and stirred at a rotational speed of 700 min ⁻¹ for 1 minute. Next, the particles were continuously classified with a mesh of 425 μm and 75 μm mesh, and the particulate polyurethane resin composition (C′-1) was colored.

Comparative Example 2
Production of Urethane Resin Particles (C′-2) Urethane resin particles (C′-2) were produced by the same operation as in Example 1 except that the rotation speed of the ultradisperser was changed to 3000 rpm.
100 parts of the obtained urethane resin particles (C′-2) and the pigment dispersion (G-1) (2.7 parts) as a colorant were put into a Henschel mixer and stirred at a rotational speed of 700 min ⁻¹ for 1 minute. did. Subsequently, the urethane resin particle composition was colored by continuously classifying with a mesh of 850 μm and 45 μm mesh.

Comparative Example 3
Production of urethane resin particles (C'-3) From 243.5 kg of polyester diol having a number average molecular weight of 1,000 obtained from 1,4-BD and adipic acid, 1,4-BG, ethylene glycol and adipic acid 243.5 parts of a polyester diol having a number average molecular weight of 2,600 and 324.7 parts of a polyester diol having a number average molecular weight of 1,500 obtained from 1,6-HG and isophthalic acid, A uniform glycol component was prepared by mixing with 1,6-HG. This glycol component and HDI were mixed and supplied from a hopper of a twin-screw extruder adjusted to a temperature of about 190 ° C. at a flow rate ratio of 100: 17.5, and resinification was performed simultaneously with kneading to obtain a polyurethane resin.

The polyurethane resin obtained in the above process is applied to a pelletizer, and 100 parts of the pelleted polyurethane resin is 0.25 parts of Irganox 245 (manufactured by Ciba Specialty Chemicals) as an antioxidant, and Tinuvin 213 is used as an ultraviolet absorber. 0.15 parts (manufactured by Ciba Specialty Chemicals), 0.15 parts chinuvin 765 (manufactured by Ciba Specialty Chemicals) as light stabilizer, and SH200-1,000CS (Toray Dow Corning) as internal release agent Was added from a hopper of a twin screw extruder whose temperature was adjusted to about 200 ° C., and kneaded to obtain a polyurethane resin.

The polyurethane resin to which the additive was added as described above was cooled to about −180 ° C. with liquid nitrogen and made into a fine powder by an impact pulverizer. In order to impart fluidity to this, 0.4 part of the dusting agent “MP-1451” is added to 100 parts of the resin, and the mixture is stirred and mixed so as to uniformly adhere to the surface of the polyurethane resin. A resin composition (C′-3) was obtained.
To 1000 g of the powdered thermoplastic polyurethane resin obtained above, black pigment: carbon black dispersion pigment “PV-817” (manufactured by Sumika Color Co., Ltd.) and white pigment: titanium oxide dispersion pigment “PV-7A1301” ( A 1.5% mixture of Sumika Color Co., Ltd. (mixing ratio 70/30) was added to the resin, put into a Henschel mixer, and stirred for 1 minute at a rotation speed of 700 min ⁻¹ . And a 45 μm wire mesh to obtain a colored powdery thermoplastic polyurethane resin composition.

Comparative Example 4
Production of urethane resin particles (C′-4) The same procedure as in Example 6 was carried out except that the amount of the dispersant used (sodium dodecyl diphenyl ether disulfonate) was changed to (10.0 parts). Primary particles (p′-4) were produced. The central particle size of the primary particles (p′-4) was 1 μm. Furthermore, by performing the same operation as in Example 6, urethane resin particles (C′-4) were obtained. Mn of (C′-4) was 25,000, and the center particle size was 190 μm.
100 parts of the obtained urethane resin particles (C′-4) and the pigment dispersion (G-1) (2.7 parts) as a colorant were put into a Henschel mixer and stirred at a rotational speed of 700 min ⁻¹ for 1 minute. did. Subsequently, the urethane resin particle composition was colored by continuously classifying with a mesh of 850 μm and 45 μm mesh.

About the resin particle of Examples 1-9 and Comparative Examples 1-4, the shape factor SF2 measured by the following method, the volume average particle diameter, the measurement result of 90% particle diameter / 10% particle diameter, and the urethane resin particle The evaluation results of the composition measured by the following method are shown in Table 1.
Table 1 shows the urea group concentration of the urethane resin constituting the urethane resin particles, the sum of the urethane group concentration and the urea group concentration, and the melting point glass transition temperature.

<Shape factor SF2>
The shape factor SF2 is measured with a scanning electron microscope (S-800: manufactured by Hitachi, Ltd.), with a center particle size of 20 μm to less than 40 μm being 300 times, particles having a particle size of 40 μm to less than 75 μm being 160 times, 80x, 150μm or more and less than 300μm particles were photographed at 40x magnification, and 300μm or more particles were photographed at 25x, and 80 particles were randomly selected from the obtained image (resolution: 1280 x 1024 pixels). This was introduced into an image analyzer (LUSEX3: manufactured by Nireco) for analysis, and an average SF2 value was calculated.

<Volume average particle diameter>
Using a Microtrac HRA particle size analyzer 9320-X100 (manufactured by Nikkiso Co., Ltd.), the particle size of 50% under sieving was measured by a laser light scattering method to obtain the central particle size.

<90% particle size / 10% particle size>
Using a Microtrac HRA particle size analyzer 9320-X100 (manufactured by Nikkiso Co., Ltd.), the particle size of 90% under the sieve and the particle size of 10% under the sieve are measured by a laser light scattering method, and 90% particle size / 10 % Particle size was determined.

<Glass transition temperature>
The glass transition temperature of the urethane resin is determined by using a dynamic viscoelasticity measuring device Rheogel-E4000 manufactured by UBM Co., Ltd. The peak top temperature was defined as the glass transition temperature.
Measurement conditions: Frequency: 10Hz
Temperature range: -90 to 140 ° C
Temperature increase rate: 5 ° C / min

<Melting point>
The melting point was a constant temperature increase under the following conditions using a flow tester CFT-500 manufactured by Shimadzu Corporation, and the melting point was defined as the temperature at which the outflow amount was halved.
Load: 5kg
Die: 0.5mmΦ-1mm
Temperature increase rate: 5 ° C./min.

<Number of particles (F) that are aggregates of pigment particles (E)>
Using a microscope, the surface of a total of 400 urethane particles is observed at a magnification of 100 times, and particles (F) that are aggregates of pigment particles (E) that are visually observed on a monitor projected at 100 times. ).

<Color fading>
After the surface temperature of the A4 size iron plate placed on the hot plate was set to 250 ° C., 50 g of the obtained resin particles were placed, the surface was leveled so that the film thickness was uniform, and 90 ° C. after 90 seconds. It cooled in the water bath, and the leveled resin film was peeled off from the iron plate. A test piece having a width of about 40 mm and a length of about 200 mm is cut out from the film and attached to a flat surface wear tester (model number FR-T, manufactured by Suga Test Instruments), and a white cotton cloth is placed on the friction element and fixed. The test piece was reciprocated 100 times with a load of 300 g of the friction element, and the color fading was evaluated. A white cotton cloth with no color was evaluated as ◯, and an attached one was evaluated as ×.

<Yield>
The weight was obtained by dividing the weight of the resin composition obtained by passing through a sieve by the weight of the resin composition before passing through the sieve.

As shown in Table 1, when the urethane resin particles of the present invention were colored, the amount of particles (F) that are aggregates of pigments was extremely small, so the particles were used as a molding material. In this case, the color developability is good and foreign matter can be reduced. In addition, since the dispersibility of the pigment is good, a high-quality molded product with less color transfer can be obtained even when the molded product is wiped with a cloth or the like.
The urethane resin particles of the present invention have a sharp molecular weight distribution and a high yield.

The urethane resin particles of the present invention can be suitably used as a material useful for slush molding, powder coating material, molding material and the like.

Claims (10)

Urethane resin particles (C) having a shape factor SF2 of 120 to 240 and a 90% particle diameter / 10% particle diameter of 2.0 to 3.0. The urethane resin particles (C) according to claim 1, which have a volume average particle diameter of 1 to 700 µm. A urethane resin (D) is contained, the urea group concentration of the urethane resin (D) is 0.5 to 10% by weight, and the total of the urethane group concentration and the urea group concentration is 4 to 20% by weight. The urethane resin particles (C) according to claim 1 or 2, having a melting point of 160 to 260 ° C and a glass transition temperature of -65 to 0 ° C. Isocyanate in which urethane resin (D) is derived from aliphatic diisocyanate (a1), monool (a2), high molecular diol (a3) having a number average molecular weight of 500 to 10,000, and optionally low molecular diol (a4) The urethane according to any one of claims 1 to 3, which is a thermoplastic urethane resin obtained by reacting a group-terminal urethane prepolymer (a) with an alicyclic diamine and / or an aliphatic diamine (b). Resin particles (C). It contains the urethane resin particles (C) according to any one of claims 1 to 4 and pigment particles (E), and the pigment particles (E) are adhered to the surfaces of the urethane resin particles (C). A featured urethane resin particle composition. The urethane resin particles (C) according to any one of claims 1 to 4, and an organic compound containing at least one ester group in a molecule having a melting point of 0 ° C or lower and a boiling point of 170 ° C or higher. H) containing a pigment dispersion (G) in which pigment particles (E) are dispersed, and having the pigment dispersion (G) attached to the surface of the urethane resin particles (C) Resin particle composition. The urethane resin particles according to claim 5 or 6, wherein the particle size is 20 to 140 µm per 100 urethane resin particles (C) and contains no more than one particle (F) that is an aggregate of pigment particles (E). Composition. It is an object for slush molding, The urethane resin particle composition of any one of Claims 5-7. A method for coloring urethane resin particles, comprising mixing the urethane resin particles (C) according to any one of claims 1 to 4 and pigment particles (E), and attaching the pigment particles (E) to the surface of (C). The urethane resin particles (C) according to any one of claims 1 to 4, and an organic compound containing at least one ester group in a molecule having a melting point of 0 ° C or lower and a boiling point of 170 ° C or higher. H) The pigment dispersion (G) in which the pigment particles (E) are dispersed in the mixture is mixed with the pigment dispersion (G) on the surface of (P), and the slush molding urethane resin particles (C) are colored. Method.