JP2009091519A - Particulate polyurethane resin composition, method for producing the same, and molded article - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide: a particulate polyurethane resin composition which is excellent in powder flowability and moldability, and from which a molded article excellent in color irregularity and feeling, and further excellent in mechanical properties, chemical resistance and long term heat resistance can be molded; a method for producing the same; and the molded article molded from the particulate polyurethane resin composition. <P>SOLUTION: The particulate polyurethane resin composition is prepared by blending a thermoplastic polyurethane resin synthesized in a nonaqueous dispersion medium, a polymer of a vinyl monomer, a thermally crosslinkable monomer, and a polymerization inhibitor whose amount is 0.1-6 parts by mass to 100 parts by mass of the thermally crosslinkable monomer. The molded article is obtained by slush-molding the particulate polyurethane resin composition. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a particulate polyurethane resin composition, a method for producing the same, and a molded product, and more specifically, a particulate polyurethane resin composition suitable for slush molding, a method for producing the same, and a molded product molded from the particulate polyurethane resin composition. About.

Slush molding is widely used for molding automobile interior parts and the like because it can easily mold a product having a complicated shape, can have a uniform thickness, and has a good material yield.
For many years, soft polyvinyl chloride powder has been used as a material for slush molding, but the texture is impaired below the freezing point of the plasticizer, and the dimensional change due to skin shrinkage due to removal of the plasticizer over time. For this reason, various studies have been made to use polyurethane resin powder instead of soft polyvinyl chloride powder.

For example, an aqueous dispersion of a vinyl monomer is mixed with an aqueous dispersion of a thermoplastic polyurethane resin and polymerized to form a core layer formed from the thermoplastic polyurethane resin and a polymer of the vinyl monomer. A slush molding powder composition including core-shell particles having a shell layer has been proposed (see, for example, Patent Document 1).
JP 2005-96432 A

However, automobile interior parts and the like are required to have mechanical strength and long-term heat resistance in addition to the texture.
An object of the present invention is a particulate polyurethane resin composition that is excellent in powder flowability, moldability, color unevenness, and texture, and can form a molded product having excellent mechanical properties, chemical resistance, and long-term heat resistance. An object of the present invention is to provide a production method thereof and a molded product molded from the particulate polyurethane resin composition.

In order to achieve the above object, the particulate polyurethane resin composition of the present invention comprises a thermoplastic polyurethane resin synthesized in a non-aqueous dispersion medium, a vinyl monomer polymer, a thermally crosslinkable monomer, and 100 masses of a thermally crosslinkable monomer. It is characterized by containing 0.1 to 6 parts by mass of a polymerization inhibitor with respect to parts.
In the particulate polyurethane resin composition of the present invention, a vinyl monomer polymer is obtained by a polymerization reaction of 35 to 70% by mass of an aromatic vinyl monomer and 30 to 65% by mass of an α, β-ethylenically unsaturated carboxylic acid alkyl ester. Is preferred.

In the particulate polyurethane resin composition of the present invention, it is preferable that the vinyl monomer polymer is contained in an amount of 5 to 40 parts by mass with respect to 100 parts by mass of the thermoplastic polyurethane resin.
In the particulate polyurethane resin composition of the present invention, it is preferable that the thermally crosslinkable monomer is contained in an amount of 2 to 10 parts by mass with respect to 100 parts by mass of the thermoplastic polyurethane resin.
In the particulate polyurethane resin composition of the present invention, the thermoplastic polyurethane resin is a dispersion of a chain extender containing a chain extender, a nonaqueous dispersion medium, and a dispersion stabilizer in an isocyanate group-terminated prepolymer in a nonaqueous dispersion medium. It is preferable that it is obtained by blending and chain elongation reaction.

In the particulate polyurethane resin composition of the present invention, the dispersion of the chain extender is 10 to 300 parts by mass of the non-aqueous dispersion medium and 0.1 to 2 parts by mass of the dispersion stabilizer with respect to 100 parts by mass of the chain extender. It is preferable to contain a part.
The molded product of the present invention is obtained by slush molding the above-mentioned particulate polyurethane resin composition.

The molded product of the present invention is preferably an automobile interior product.
In the method for producing the particulate polyurethane resin composition of the present invention, a dispersion of a chain extender containing a chain extender, a non-aqueous dispersion medium and a dispersion stabilizer is blended with the isocyanate group-terminated prepolymer in the non-aqueous dispersion medium. Then, a thermoplastic polyurethane resin is synthesized by chain extension reaction, and an aromatic vinyl monomer and an α, β-ethylenically unsaturated carboxylic acid alkyl ester are blended in the non-aqueous dispersion medium to cause a polymerization reaction. Thus, a vinyl monomer polymer is synthesized, and a heat-crosslinkable monomer and a polymerization inhibitor are blended in the non-aqueous dispersion medium.

  In the method for producing the particulate polyurethane resin composition of the present invention, the dispersion of the chain extender is 10 to 300 parts by mass of the non-aqueous dispersion medium and 0.1 of the dispersion stabilizer with respect to 100 parts by mass of the chain extender. It is preferable to contain ˜2 parts by mass.

  According to the particulate polyurethane resin composition of the present invention, by containing 0.1 to 6 parts by mass of a polymerization inhibitor with respect to 100 parts by mass of the thermally crosslinkable monomer, the curing reaction of the thermally crosslinkable monomer in the molding process. Can be controlled, and a crosslinked structure can be introduced without impairing the moldability of the particulate polyurethane resin composition. Thereby, long-term heat resistance can be improved while maintaining the original appearance, touch and moldability of the polyurethane resin. In addition, by containing a thermoplastic polyurethane resin synthesized in a non-aqueous dispersion medium, a vinyl monomer polymer, a thermally crosslinkable monomer, and a polymerization inhibitor, the appearance, feel, moldability and long-term heat resistance of the molded product can be improved. Can be improved.

Therefore, the particulate polyurethane resin composition of the present invention is excellent in powder flowability and moldability, and a molded product molded from the particulate polyurethane resin composition has uneven color, texture, mechanical properties, chemical resistance and Excellent long-term heat resistance.
Furthermore, according to the method for producing a particulate polyurethane resin composition of the present invention, it is possible to greatly suppress the formation of fine powders and irregularly shaped particles and to prevent sedimentation of the dispersed phase, which is stable in a non-aqueous dispersion medium. It is possible to obtain a suitable particle by enabling a simple chain extension. In addition, the production process can be simplified, and the particulate polyurethane resin composition can be produced in one stage.

The particulate polyurethane resin composition of the present invention contains a thermoplastic polyurethane resin, a vinyl monomer polymer, a thermally crosslinkable monomer, and a polymerization inhibitor.
In the present invention, the thermoplastic polyurethane resin can be obtained by reacting an isocyanate group-terminated prepolymer with a chain extender in a non-aqueous dispersion medium.
Isocyanate-terminated prepolymers are synthesized from isocyanates, polyols, optionally monools and / or monoamines.

The isocyanate is not particularly limited as long as it is an organic isocyanate used in the production of a polyurethane resin, and preferably an alicyclic polyisocyanate. If alicyclic polyisocyanate is used, the blooming resistance of a molded article can be improved.
Examples of the alicyclic polyisocyanate include 1,3-cyclopentane diisocyanate, 1,4-cyclohexane diisocyanate, 1,3-cyclohexane diisocyanate, 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate, 4, 4'-methylenebis (cyclohexyl isocyanate), methyl-2,4-cyclohexane diisocyanate, methyl-2,6-cyclohexane diisocyanate, 1,3-bis (isocyanatomethyl) cyclohexane or 1,4-bis (isocyanatomethyl) cyclohexane And isomer mixtures thereof, 1,3-bis (isocyanatoethyl) cyclohexane or 1,4-bis (isocyanatoethyl) cyclohexane and isomer mixtures thereof.

  Among the alicyclic polyisocyanates, preferably, 4,4′-methylenebis (cyclohexyl isocyanate) in which three kinds of isomers of trans-trans, trans-cis and cis-cis are mixed, trans-trans isomer ratio 4,4′-methylenebis (cyclohexyl isocyanate), 1,3-bis (isocyanatomethyl) cyclohexane or 1,4-bis (isocyanatomethyl) cyclohexane and their isomer mixtures.

  As the isocyanate, an aliphatic polyisocyanate can be used in combination as long as the blooming resistance of the molded product is not impaired. Examples of the aliphatic polyisocyanate include trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, pentamethylene diisocyanate, hexamethylene diisocyanate, 1,2-propylene diisocyanate, 1,2-butylene diisocyanate, 2,3-butylene diisocyanate, Examples include 1,3-butylene diisocyanate, 2,4,4- or 2,2,4-trimethylhexamethylene diisocyanate, 2,6-diisocyanate methyl caproate, and the like.

  Furthermore, as the isocyanate, monoisocyanate can be used in combination as long as the long-term heat resistance of the molded product is not impaired. Examples of the monoisocyanate include methyl isocyanate, ethyl isocyanate, n-hexyl isocyanate, cyclohexyl isocyanate, 2-ethylhexyl isocyanate, phenyl isocyanate, and benzyl isocyanate.

These isocyanates may be used alone or in combination of two or more. Preferably, an alicyclic polyisocyanate is used alone. Moreover, when using together an isocyanate, Preferably it is 70 mol% or more, More preferably, 80 mol% or more of alicyclic polyisocyanate is contained with respect to the total mole of the isocyanate used together.
In the present invention, examples of the polyol include polyether polyols, polyester polyols, polycarbonate polyols, and polymer polyols obtained by polymerizing vinyl monomers such as styrene, acrylonitrile, and (meth) acrylic acid esters in these polyols. A high molecular weight polyol having a number average molecular weight of 900 to 5000 or a hydroxyl value of 10 to 125 mgKOH / g can be mentioned. The number average molecular weight of the high molecular weight polyol is preferably 1400 to 3000, and more preferably 1500 to 2500. On the other hand, when a polymer polyol is used, its hydroxyl value is preferably about 20 to 80 mgKOH / g.

Examples of the polyether polyol include polypropylene glycol and polytetramethylene ether glycol.
Examples of the polypropylene glycol include addition polymers of alkylene oxides such as ethylene oxide and propylene oxide (a random and / or block copolymer of two or more alkylene oxides), which are initiated with a low molecular weight polyol or a low molecular weight polyamine. Included).

  The low molecular weight polyol is a compound having two or more hydroxyl groups and a number average molecular weight of 60 to 400, and includes ethylene glycol, propanediol, 1,4-butylene glycol, 1,3-butylene glycol, 1,2- Butylene glycol, 1,6-hexanediol, neopentyl glycol, alkane (7-22) diol, diethylene glycol, triethylene glycol, dipropylene glycol, 1,3- or 1,4-cyclohexanedimethanol and mixtures thereof; , 4-cyclohexanediol, alkane-1,2-diol (C17-20), hydrogenated bisphenol A, 1,4-dihydroxy-2-butene, 2,6-dimethyl-1-octene-3,8-diol, Dihydric alcohols such as bisphenol A, eg For example, trivalent alcohols such as glycerin and trimethylolpropane, such as tetramethylolmethane, pentaerythritol, dipentaerythritol, D-sorbitol, xylitol, D-mannitol, D-mannitol, and other polyhydric groups having four or more hydroxyl groups. And monohydric alcohol.

Examples of the polytetramethylene ether glycol include a ring-opening polymer obtained by cationic polymerization of tetrahydrofuran, and an amorphous polytetramethylene ether glycol obtained by copolymerizing the above dihydric alcohol such as neopentyl glycol with a repeating unit of tetrahydrofuran. Etc.
Examples of the polyester polyol include polycondensates obtained by reacting the above dihydric alcohol and polybasic acid under known conditions.

  Examples of the polybasic acid include oxalic acid, malonic acid, succinic acid, methyl succinic acid, glutaric acid, adipic acid, 1,1-dimethyl-1,3-dicarboxypropane, and 3-methyl-3-ethylglutaric acid. , Azelaic acid, sebacic acid, other aliphatic dicarboxylic acids (11 to 13 carbon atoms), hydrogenated dimer acid, maleic acid, fumaric acid, itaconic acid, orthophthalic acid, isophthalic acid, terephthalic acid, toluene dicarboxylic acid, dimer acid And carboxylic acids such as het acid, and acid anhydrides and acid halides derived from these carboxylic acids.

Further, as the polyester polyol, for example, polycaprolactone polyol, polyvalerolactone polyol obtained by ring-opening polymerization of lactones such as ε-caprolactone and γ-valerolactone using the above dihydric alcohol as an initiator, Furthermore, the lactone type | system | group polyol which copolymerized said dihydric alcohol to them etc. are mentioned.
Examples of the polycarbonate polyol include a ring-opening polymer of ethylene carbonate using the above dihydric alcohol as an initiator, and examples thereof include 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, and the like. Examples thereof include amorphous polycarbonate polyol obtained by copolymerizing a dihydric alcohol and a ring-opening polymer.

Furthermore, the above-mentioned low molecular weight polyol can be used in combination as the polyol.
Examples of monools include methanol, ethanol, propanol, butanol, 2-ethylhexyl alcohol, other alkanols (C5-38) and aliphatic unsaturated alcohols (9-24), alkenyl alcohols, 2-propen-1-ols. , Alkadienol (C6-8), 3,7-dimethyl-1,6-octadien-3-ol, and the like.

  Examples of the monoamine include dimethylamine, diethylamine, di-n-propylamine, diisopropylamine, di-n-butylamine, diisobutylamine, di-t-butylamine, dihexylamine, 2-ethylhexylamine, 3-methoxypropylamine, Examples include 3-ethoxypropylamine, 3- (2-ethylhexyloxypropylamine), 3- (dodecyloxy) propylamine, N, N-dimethyl1,3-propanediamine, morpholine, and the like.

The monool and / or monoamine is blended as necessary to adjust the molecular weight of the thermoplastic polyurethane resin.
In order to synthesize an isocyanate group-terminated prepolymer, an equivalent ratio of isocyanate groups of isocyanate to isocyanate and / or monoamine and / or monoamine active hydrogen groups (hydroxyl groups and amino groups) (isocyanate groups / active hydrogen groups). ) Is, for example, 1.1 to 4, preferably 1.4 to 2.5, and they are mixed and reacted. If the equivalent ratio is less than 1.1, the thermoplastic polyurethane resin may have an excessively high molecular weight, which may reduce moldability. On the other hand, when the equivalent ratio exceeds 4, the molded product of the thermoplastic polyurethane resin becomes hard, and the tactile sensation may be impaired.

This reaction is carried out, for example, under a nitrogen atmosphere at a reaction temperature of 60 to 95 ° C., preferably 70 to 90 ° C., for a reaction time of 2 to 7 hours, preferably 3 to 5 hours. The reaction is terminated when the group content (for example, 2 to 6% by weight) is reached.
In this reaction, if necessary, a catalyst such as amines or organometallic compounds can be added. Preferred examples of the catalyst include organometallic compounds. Examples of such organometallic compounds include tin acetate, tin octylate, tin oleate, tin laurate, dibutyltin diacetate, dimethyltin dilaurate, and dibutyltin. Examples include dilaurate, dioctyltin dilaurate, dibutyltin dichloride, lead octoate, lead naphthenate, nickel naphthenate, cobalt naphthenate, copper octenoate, and bismuth catalysts. A catalyst can be used individually or in combination of 2 or more types, for example, 0.001-5 mass parts with respect to 100 mass parts of polyols, Preferably, 0.01-3 mass parts is added.

Then, the obtained isocyanate group-terminated prepolymer and the chain extender are subjected to a chain extension reaction in a non-aqueous dispersion medium to obtain a thermoplastic polyurethane resin.
In the present invention, examples of the chain extender include diamines such as alicyclic diamines and aliphatic diamines, for example, low molecular weight polyols such as the above dihydric alcohols and the above trihydric alcohols.

  Examples of the alicyclic diamine include 1-amino-3-aminomethyl-3,5,5-trimethylcyclohexane, bis- (4-aminocyclohexyl) methane, diaminocyclohexane, and 3,9-bis (3-aminopropyl). ) -2,4,8,10-tetraoxaspiro [5,5] undecane, 1,3- and 1,4-bis (aminomethyl) cyclohexane and mixtures thereof.

  Examples of the aliphatic diamine include ethylene diamine, propylene diamine, hexamethylene diamine, hydrazine, 1,2-diaminoethane, 1,2-diaminopropane, 1,3-diaminopentane, and the like. Of these chain extenders, the diamine is preferably 1-amino-3-aminomethyl-3,5,5-trimethylcyclohexane, bis- (4-aminocyclohexyl) methane, 1,3- and 1,4- Bis (aminomethyl) cyclohexane and mixtures thereof, hexamethylenediamine. Further, as the low molecular weight polyol, preferably, ethylene glycol, 1,4-butanediol, 1,6-hexamethylene glycol, 1,4-cyclohexanediol, 1,3-, 1,4-cyclohexanedimethanol and their A mixture etc. are mentioned.

When 4,4′-methylenebis (cyclohexyl isocyanate) is used as the polyisocyanate, most preferred are diamines such as 1,4-bis (aminomethyl) cyclohexane and hexamethylenediamine, and ethylene glycol.
Chain extenders can be used alone or in combination of two or more.
The chain extender has an equivalent ratio (active hydrogen group / isocyanate group) of active hydrogen groups (amino groups and hydroxyl groups) of the chain extender to isocyanate groups of the isocyanate group-terminated prepolymer, for example, 0.8 to 1.1, Preferably, it mix | blends in the ratio used as 0.9-1.05.

The non-aqueous dispersion medium is a solvent that does not substantially dissolve the isocyanate group-terminated prepolymer and the thermoplastic polyurethane resin, and includes, for example, aliphatic hydrocarbons such as hexane, heptane, octane, pentane, cyclohexane and isomers thereof, and An alicyclic hydrocarbon etc. are mentioned.
Furthermore, esters, ketones, aromatic hydrocarbons and the like can be used in combination as the non-aqueous dispersion medium as long as the excellent effects of the present invention are not impaired.

  Esters include alkyl esters such as methyl acetate, ethyl acetate, n-butyl acetate, isobutyl acetate, amyl acetate, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol mono-n-butyl ether acetate. And ether esters such as ethyl ethoxypropionate.

Examples of ketones include acetone, methyl ethyl ketone, methyl isobutyl ketone, methyl amyl ketone, and cyclohexanone.
Examples of aromatic hydrocarbons include toluene, xylene, ethylbenzene, and the like.
In the chain extension reaction, preferably, in the synthesis of the isocyanate group-terminated prepolymer, first, when the desired isocyanate group content is reached, a non-aqueous dispersion medium is blended into the isocyanate group-terminated prepolymer, and the isocyanate group-terminated prepolymer is blended. The polymer is dispersed in a non-aqueous dispersion medium.

  The non-aqueous dispersion medium is blended in an amount of, for example, 10 to 150 parts by mass, preferably 25 to 120 parts by mass with respect to 100 parts by mass of the isocyanate group-terminated prepolymer. Thereafter, for example, at 15 to 130 ° C., while confirming the dispersion state of the isocyanate group-terminated prepolymer, the mixture is stirred at a rotational speed of 50 to 3000 rpm, and the isocyanate group-terminated prepolymer is dispersed in a non-aqueous dispersion medium. A prepolymer dispersion is prepared.

  The non-aqueous dispersion medium can be added to the isocyanate group-terminated prepolymer all at once or dividedly. In order to make the particle diameter of the isocyanate group-terminated prepolymer uniform, it is preferably added in portions. When dividing, the initial addition amount is preferably 5 to 100 parts by mass, more preferably 10 to 70 parts by mass with respect to 100 parts by mass of the isocyanate group-terminated prepolymer. When the desired particle size is reached, for example, 30-500 μm, the remainder is added.

  And a chain extender is mix | blended with a prepolymer dispersion liquid. When a diamine is used as a chain extender, the amino group has high reactivity with the isocyanate group of the isocyanate group-terminated prepolymer, and the urea bond produced by the reaction has very high intermolecular cohesion. Therefore, it is necessary to reduce the local reaction between the chain extender and the isocyanate monomer. Therefore, the chain extender is preferably formulated as an aqueous solution. The concentration of the diamine in the aqueous solution is preferably at least 20% by mass, and more preferably at least 50% by mass. If the chain extender is blended as an aqueous solution, the solubility in the non-aqueous dispersion medium can be reduced, and the reaction with the isocyanate monomer dissolved in the non-aqueous dispersion medium can be reduced. Particle generation can be greatly suppressed.

Furthermore, if a dispersion stabilizer is added to the non-aqueous dispersion medium, the sedimentation of the dispersed phase can be prevented, and stable chain extension can be achieved in the non-aqueous dispersion medium, whereby suitable particles can be obtained.
Examples of the dispersion stabilizer include a dispersant described in JP-A No. 2004-169011, for example, a resin obtained by dehydration condensation of alkenyl succinic anhydride and polyol or polyester polyol, for example, dehydration of dicarboxylic acid and pentaerythritol. An alkyd resin obtained by dehydrating and condensing a fatty acid to a part of the residual OH group of the polyester obtained by condensation, such as a polyol obtained by dehydration condensation of an unsaturated bond-containing dicarboxylic acid and a polyol or polyester polyol, After graft polymerization of the monomer, the OH group of a resin obtained by masking the OH group, for example, a polyol obtained by dehydration condensation of an unsaturated bond-containing dicarboxylic acid and a polyol or polyester polyol is masked, and then an ethylenically unsaturated monomer is used. Graft polymerization of the polymer It was like resin obtained.

The compounding quantity of a dispersion stabilizer is 0.05-5 mass parts with respect to 100 mass parts of isocyanate group terminal prepolymers, Preferably, it is 0.1-3 mass parts, More preferably, it is 0.15-1. .5 parts by mass.
Specifically, for example, a chain extender dispersion containing a chain extender, a non-aqueous dispersion medium and a dispersion stabilizer is first prepared.

  The dispersion of the chain extender is, for example, 10 to 300 parts by mass of the non-aqueous dispersion medium, preferably 20 to 120 parts by mass, and 0.1 to 2 parts by mass of the dispersion stabilizer, with respect to 100 parts by mass of the chain extender. Preferably, it prepares by mix | blending them in the ratio of 0.15-1.5 mass part. As described above, the chain extender is preferably prepared in advance in an aqueous solution of at least 20% by mass and blended in the above ratio. If the dispersion of the chain extender is prepared as described above, the aggregation of the particles in the non-aqueous dispersion medium can be suppressed, and the chain extension reaction can be stabilized.

And in order to mix | blend the dispersion liquid of a chain extender with an isocyanate group terminal prepolymer, you may add collectively or divided | segmenting, or can also be dripped.
The temperature of the chain extender dispersion is adjusted to, for example, 10 to 80 ° C, preferably 15 to 50 ° C, and more preferably 15 to 40 ° C.
On the other hand, the temperature of the prepolymer dispersion is adjusted to, for example, 5 to 100 ° C., preferably 10 to 80 ° C., and more preferably 15 to 60 ° C.

In the chain extension reaction, for example, 20 to 100 ° C., preferably 20 to 40 ° C. after addition of the dispersion of the chain extender, depending on the scale, is allowed to react for 0.5 to 5 hours, The reaction is carried out at 40-60 ° C for 0.5-5 hours, and finally the reaction is completed at 70-100 ° C. If necessary, the above-mentioned catalyst can be added as appropriate.
As a result, a thermoplastic polyurethane resin synthesized in a non-aqueous dispersion medium is obtained.

In the present invention, the vinyl monomer polymer is, for example, a copolymer of an aromatic vinyl monomer and an α, β-ethylenically unsaturated carboxylic acid alkyl ester, wherein the aromatic vinyl monomer and the α, β-ethylenic unsaturated polymer are It can be obtained by a radical copolymerization reaction with a saturated carboxylic acid alkyl ester.
Examples of the aromatic vinyl monomer include styrene monomers such as styrene and α-methylstyrene, alkyl vinylbenzenes such as vinyltoluene and ethylvinylbenzene, and polycyclic aromatic monovinyl monomers such as vinylnaphthalene. .

These aromatic vinyl monomers can be used alone or in combination of two or more. Of these, styrene is preferable.
Examples of the α, β-ethylenically unsaturated carboxylic acid alkyl ester include acrylate, and examples of the acrylate include ethyl acrylate, propyl acrylate, butyl acrylate, cyclohexyl acrylate, isononyl acrylate, 2-ethylhexyl acrylate, and methyl. Examples include alkyl (meth) acrylates such as methacrylate, butyl methacrylate, cyclohexyl methacrylate, and 2-ethylhexyl methacrylate. Examples of the α, β-ethylenically unsaturated carboxylic acid alkyl ester include vinyl cyanide or vinylidene cyanide such as acrylonitrile and methacrylonitrile.

These α, β-ethylenically unsaturated carboxylic acid alkyl esters can be used alone or in combination of two or more. Of these, methyl methacrylate and butyl methacrylate are preferable.
And in order to carry out the radical copolymerization reaction of the aromatic vinyl monomer and the α, β-ethylenically unsaturated carboxylic acid alkyl ester, the aromatic vinyl monomer is 35 to 70% by mass, preferably While 45-65 mass%, (alpha), (beta) -ethylenically unsaturated carboxylic acid alkylester is mix | blended in the ratio of 30-65 mass%, Preferably, 35-55 mass%, and a radical polymerization initiator is added.

Examples of the radical polymerization initiator include organic peroxides and azo compounds.
Examples of the organic peroxide include 1,1-di (t-hexylperoxy) -3,3,5-trimethylcyclohexane, 1,1-di (t-hexylperoxy) -2-methylcyclohexane, Peroxyketals such as 1,1-di (t-butylperoxy) cyclohexane, for example, dialkyl peroxides such as di-t-butyl peroxide, such as dilauroyl peroxide, di- (3-methylbenzoyl) Diacyl peroxides such as peroxide, benzoyl (3-methylbenzoyl) peroxide, dibenzoyl peroxide, such as 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, 2,5 -Dimethyl-2,5-di (2-ethylhexanoylperoxy) hexane, t-hex Luperoxy-2-ethylhexanoate, t-butylperoxy-2-ethylhexanoate, t-hexylperoxyisopropyl monocarbonate, t-butylperoxylaurate, t-butylperoxyisopropyl monocarbonate, t- And peroxyesters such as butyl peroxy-2-ethylhexyl monocarbonate and 2,5-dimethyl-2,5-di (benzoylperoxy) hexane.

  Examples of the azo compound include azobisisobutyronitrile, 2,2′-azobis (2,4-dimethylvaleronitrile), 2,2′-azobis (2-methylbutyronitrile), dimethyl 2,2 '-Azobis (2-methylpropionate), 2,2'-azobis ((2- (2-imidazolin-2-yl) propane, dimethylmethylpropaneisobutyrate, 2,2,7-azobis [N- ( 2-carboxyl) -2-methylpropionamidine] tetrahydrate, 2,2′-azobis [2-methyl-N- [1,1-bis (hydroxymethyl) -2-hydroxyethyl] propionamide], 2, 2'-azobis [N- (2-hydroxyethyl) -2-methylpropanamide], 2,2'-azobis (2,4-dimethyl-4-methoxyvalerontri) ), And the like 1,1'-azobis [cyclohexane-1-carbonitrile.

These radical polymerization initiators can be used alone or in combination of two or more. Of these, dimethyl 2,2′-azobis (2-methylpropionate) and 2,2′-azobis (2-methylbutyronitrile) are preferable.
The radical polymerization initiator is added in an amount of, for example, 0.1 to 10 parts by mass, preferably 1 to 7 parts by mass with respect to 100 parts by mass of the total amount of monomers.

In the radical copolymerization reaction, a chain transfer agent is preferably added to adjust the molecular weight of the vinyl monomer polymer.
Examples of the chain transfer agent include mercaptans such as t-dodecyl mercaptan and 2-ethylhexyl thioglycolate, and styrene dimers such as α-methylstyrene dimer.

These chain transfer agents can be used alone or in combination of two or more. Of these, α-methylstyrene dimer is preferable.
The chain transfer agent is added, for example, 0 to 10 parts by mass, preferably 0.01 to 5 parts by mass, and more preferably 0.01 to 2 parts by mass with respect to 100 parts by mass of the total amount of monomers.
In the radical copolymerization reaction, the above-described monomer is reacted, for example, at a reaction temperature of 20 to 130 ° C., preferably 30 to 80 ° C., for a reaction time of 1 to 20 hours, preferably 2 to 15 hours.

Monomer charging may be performed in a batch, divided, or sequential manner. However, when charging in batches, the reaction temperature is preferably initially set low and then used for the operation in scale-up. In light of the half-life of the radical initiator, the temperature is gradually increased until the target reaction temperature is reached.
The vinyl monomer polymer is synthesized separately from the thermoplastic polyurethane resin synthesized in the non-aqueous dispersion medium under the above conditions, and may be blended with the non-aqueous dispersion medium in which the thermoplastic polyurethane resin is dispersed. it can. In addition, the vinyl monomer polymer is added to the non-aqueous dispersion medium in which the thermoplastic polyurethane resin or the isocyanate group-terminated prepolymer is dispersed, to the above-described monomer, radical polymerization initiator, and optionally a chain transfer agent (if necessary, these are previously It can also be synthesized under the above conditions in a non-aqueous dispersion medium. With the latter method, the manufacturing process can be simplified.

A vinyl monomer polymer is 5-40 mass parts with respect to 100 mass parts of thermoplastic polyurethane resins, Preferably, it is 6-30 mass parts, More preferably, 6-20 mass parts is mix | blended.
In the present invention, the thermally crosslinkable monomer is a compound having a plurality of ethylenically unsaturated bonds, such as ethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, butylene glycol di (meth) acrylate, Alkanediol di (meth) acrylates such as pentanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, hexanediol di (meth) acrylate, nonanediol di (meth) acrylate, oligoethylene glycol di (meth) acrylate For example, trimethylolpropane tri (meth) acrylate, glycerol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate , Alkane polyols such as dipentaerythritol hexa (meth) acrylate, poly (meth) acrylates such as diallyl maleate, diallyl fumarate, diallyl itaconate and other unsaturated carboxylic acid diallyl esters such as urethane di (meth) acrylate, Examples thereof include polybutadiene di (meth) acrylate. Of these, dipentaerythritol penta (meth) acrylate and dipentaerythritol hexa (meth) acrylate are preferable.

These thermally crosslinkable monomers can be used alone or in combination of two or more. Of these, alkane polyol poly (meth) acrylate is preferable. For example, 2 to 10 parts by mass, and preferably 4 to 8 parts by mass of the heat-crosslinkable monomer is added to 100 parts by mass of the thermoplastic polyurethane resin.
Specifically, the thermally crosslinkable monomer is blended and mixed in a non-aqueous dispersion medium containing a thermoplastic polyurethane resin and a vinyl monomer polymer.

  In the present invention, examples of the polymerization inhibitor include quinones such as p-benzoquinone, p-methoquinone, naphthoquinone, phenanthraquinone, tolquinone, and 2,5-diphenyl-p-benzoquinone, such as hydroquinone and p-t. Hydroquinones such as -butylcatechol, 2,5-di-t-butylhydroquinone, mono-t-butylhydroquinone, 2,5-di-t-amylhydroquinone, such as p-methoxyphenol, di-t-butyl Examples thereof include phenols such as paracresol hydroquinone monomethyl ether.

  These polymerization inhibitors can be used alone or in combination of two or more. Of these, hydroquinone and p-methoxyphenol are preferable. The polymerization inhibitor is blended in an amount of, for example, 0.1 to 6 parts by weight, preferably 0.1 to 5 parts by weight, and more preferably 0.1 to 4 parts by weight with respect to 100 parts by weight of the thermally crosslinkable monomer. . When the blending amount of the polymerization inhibitor is less than 0.1 parts by mass, uneven color, texture, and long-term heat resistance are reduced. On the other hand, when the blending amount of the polymerization inhibitor exceeds 6 parts by mass, uneven color, mechanical strength, long-term heat resistance and the like are lowered. If the number of parts of the polymerization inhibitor is within the above range, it is possible to obtain a molded product having excellent color unevenness and texture, and excellent mechanical properties, chemical resistance and long-term heat resistance.

Specifically, the polymerization inhibitor is blended and mixed together with a thermally crosslinkable monomer in a non-aqueous dispersion medium containing a thermoplastic polyurethane resin and a vinyl monomer polymer.
Then, the solid component is separated from the non-aqueous dispersion medium by a separation means such as filtration, and dried at a temperature (about 40 to 70 ° C.) at which the thermally crosslinkable monomer does not react in the presence of an inert gas, for example. By doing so, the particulate polyurethane resin composition of the present invention is obtained.

Thus, if the particulate polyurethane resin composition is produced in a non-aqueous dispersion medium, the particulate polyurethane resin composition can be produced in one step, and the drying time of the obtained particulate polyurethane resin composition is shortened. can do. Further, if the non-aqueous dispersion medium is recovered and distilled, it can be reused.
The volume average particle diameter of the obtained particulate polyurethane resin composition is, for example, 50 to 300 μm, or preferably 80 to 200 μm. If the volume average particle diameter is less than 50 μm, unevenness may occur during molding due to a decrease in powder fluidity. On the other hand, if the volume average particle diameter exceeds 300 μm, pinholes may occur on the surface of the molded product.

  For the particulate polyurethane resin composition, other known additives such as a plasticizer, an anti-blocking agent, a heat stabilizer, a light stabilizer, a release agent, an antioxidant, an ultraviolet ray are optionally added to the particulate polyurethane resin composition. Absorbers, pigments, dyes, lubricants, fillers, hydrolysis inhibitors and the like can be added. These additives may be added at the time of synthesis of each component, or may be added at the time of mixing / dispersing each component, and may be added after separation / drying of the particulate polyurethane resin composition. .

  In the particulate polyurethane resin composition of the present invention, the curing reaction of the thermally crosslinkable monomer in the molding process is performed by adding 0.1 to 6 parts by mass of a polymerization inhibitor to 100 parts by mass of the thermally crosslinkable monomer. Can be controlled, and a crosslinked structure can be introduced without impairing the moldability of the particulate polyurethane resin composition. Thereby, long-term heat resistance can be improved while maintaining the original appearance, touch and moldability of the polyurethane resin. In addition, by containing a thermoplastic polyurethane resin synthesized in a non-aqueous dispersion medium, a vinyl monomer polymer, a thermally crosslinkable monomer, and a polymerization inhibitor, the appearance, feel, moldability and long-term heat resistance of the molded product can be improved. Can be improved.

Therefore, the particulate polyurethane resin composition of the present invention is excellent in powder flowability and moldability, and a molded product molded from the particulate polyurethane resin composition has uneven color, texture, mechanical properties, chemical resistance and Excellent long-term heat resistance.
Therefore, the particulate polyurethane resin composition of the present invention can be used as a toner binder and is suitable for slush molding and used in various fields such as furniture sheets, sofas and toys where slush molding is performed. Is done. In particular, the particulate polyurethane resin composition of the present invention can be suitably used for automobile interior parts molded by slush formation.

  And the molded article obtained by carrying out the slush formation of the particulate polyurethane resin composition of this invention, especially a motor vehicle interior goods, are excellent in color shading, texture, mechanical properties, chemical resistance, and long-term heat resistance.

Next, although this invention is demonstrated based on a manufacture example, an Example, and a comparative example, this invention is not limited by the following Example.
Production Example 1 (Production Method of Dispersion Stabilizer (I))
2000 parts by weight of adipate-based polyester polyol (trade name U-2610, manufactured by Mitsui Chemicals Polyurethanes Co., Ltd.) and 98 parts by weight of maleic anhydride were placed in a three-necked flask equipped with a stirrer. Stir at 20 ° C. for 20 hours. Furthermore, while nitrogen bubbling, the temperature was gradually raised to 170 ° C. under a reduced pressure of 2.66 kPa, and the mixture was stirred at the same temperature for 5 hours. As a result, a polyol containing an unsaturated bond was obtained.

After raising the temperature to 70 ° C. under a nitrogen atmosphere, 200 parts by mass of ethyl isocyanate is gradually added dropwise to 1300 parts by mass of the unsaturated bond-containing polyol, and reacted at 75-80 ° C. for 6 hours. An unsaturated bond-containing compound having a urethane bond was synthesized.
Next, the unsaturated bond-containing compound was subjected to reduced pressure treatment under conditions of 130 ° C. and 0.66 kPa or less. Furthermore, 11547 parts by mass of butyl acetate was added to 6077 parts by mass of the unsaturated bond-containing compound to prepare a uniform solution, which was then sufficiently purged with nitrogen and heated to 110 ° C.

A monomer solution in which 21270 parts by weight of lauryl methacrylate and 1100 parts by weight of benzoyl peroxide were mixed in advance at 110 ° C. in a nitrogen atmosphere was dropped in about 1 hour. After reacting at 110 to 120 ° C. for 2 hours, the reaction was further performed at 130 ° C. for 2 hours. A dispersion stabilizer (I) having a solid content of about 65% by mass was obtained.
Example 1 (Production of particulate polyurethane resin composition)
<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 by mass of Takelac U-2024 (manufactured by Mitsui Chemicals Polyurethane Co., Ltd., polyester polyol) as a polyol and Irganox 245 (Ciba) as an antioxidant 0.05 parts by mass of Specialty Chemicals), and 21.6 parts by mass of 4,4′-methylenebis (cyclohexyl isocyanate) (manufactured by Sumika Bayer Urethane Co., Ltd., trade name: Desmodur W) as isocyanate, The temperature was raised to 80 to 85 ° C. with stirring.

Next, 0.49 parts by mass of 2-ethylhexyl alcohol (manufactured by Wako Pure Chemical Industries, Ltd.) was charged as a monool. After the reaction was continued for about 3.5 hours, it was confirmed that NCO mass% had decreased to 3.6 mass%, and an isocyanate group-terminated prepolymer was obtained.
Thereafter, 0.45 parts by mass of the dispersion stabilizer (I) and 29.2 parts by mass of n-heptane, which were mixed in advance, were charged all at once into the reaction vessel, and the isocyanate group-terminated prepolymer was dispersed over 1 hour. I let you.

Subsequently, 58.4 parts by mass of n-heptane was charged at a rate of 30 ml / min, and then the reaction temperature was lowered to 25 ° C. A chain prepared by previously dispersing 2.7 parts by mass of a 70% by mass aqueous solution of 1,6-hexamethylenediamine in 0.06 parts by mass of the dispersion stabilizer (I) and 3.86 parts by mass of n-heptane. The extender 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.
<Composition of vinyl monomer polymer>
After mixing so that styrene and methyl methacrylate become 60 mass% and 40 mass%, respectively, α-methylstyrene dimer which becomes 0.5 mass parts is added to 100 mass parts of those monomers, and further uniform Mixed.

Next, dimethyl 2,2′-azobis (2-methylpropionate) (manufactured by Wako Pure Chemical Industries, Ltd., product) as a radical polymerization initiator with respect to 100 parts by mass of the total amount of monomers (total amount of styrene and methyl methacrylate) 4 parts by mass of name: 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.
<Composition of thermally crosslinkable monomer and polymerization inhibitor>
Thereafter, with respect to 100 parts by mass of the thermoplastic polyurethane resin, 0.5 part by mass of TINUVIN 213 (manufactured by Ciba Specialty Chemicals) as a benzotriazole-based UV absorber and TINUVIN 765 (manufactured by Ciba Specialty Chemicals) as a hindered amine light-resistant stabilizer 0.5 parts by mass, 6 parts by mass of a mixture of dipentaerythritol hexaacrylate and dipentaerythritol pentaacrylate (manufactured by Nippon Kayaku Co., Ltd., trade name: Kayarad DPHA) as a thermally crosslinkable monomer, p-methoxyphenol as a polymerization inhibitor The thermoplastic polyurethane resin dispersion was charged to 1 part by mass with respect to 100 parts by mass of the thermally crosslinkable 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, in a Nauter mixer type dryer, 100 parts by mass of solids, 0.5 part by mass of TSF-451-3000 (silicon oil manufactured by GE Toshiba Silicone Co., Ltd.) as a release agent, and 0.3 parts by mass of an antiblocking agent were added. The mixture was charged and dried at 40 ° C. for 3 hours with stirring under reduced pressure. Then, after cooling the content to 25 degrees C or less, it discharged | emitted and the particulate polyurethane resin composition was obtained.
<Combination of additives>
100 parts by mass of the obtained particulate polyurethane resin composition, as a pigment, 0.6 parts by mass of carbon black / calcium carbonate dispersion (manufactured by Sumika Color Co., Ltd., trade name: PV-817) and 0.4 parts by mass Carbon black / calcium carbonate dispersion (manufactured by Sumika Color Co., Ltd., trade name: PV-801) was put into a Henschel mixer and stirred at a rotation speed of 700 min ⁻¹ for 1 minute. Next, after passing through a 48-mesh sieve, a 200-mesh sieve was further passed to color the particulate polyurethane resin composition.

Examples 2 to 19 (excluding Example 12), Comparative Examples 1 to 5
A particulate polyurethane resin composition was produced and colored by the same method as in Example 1 except that the compositions and blending ratios shown in Tables 1 to 3 were used.
Example 12 (Production of particulate polyurethane resin composition: different chain extension methods)
In the same manner as in Example 1, an isocyanate group-terminated prepolymer was synthesized.

Next, after 58.4 parts by mass of n-heptane was charged at a rate of 30 ml / min, the reaction temperature was lowered to 25 ° C., and 2.7 parts by mass of 1,6-hexamethylenediamine was added in a 70% by mass aqueous solution. As a whole, it was charged in bulk.
After completion of charging, the reaction was carried out at 25 to 35 ° C. for 30 minutes. In the meantime, the viscosity of the dispersion increased, but the reaction was continued as it was. The temperature was raised to 45 ° C. 60 minutes after the end of charging of the chain extender, and then the reaction was continued for 30 minutes at the same temperature. Finally, the reaction temperature was raised to 80 to 85 ° C. and reacted for 3 hours. . Thereafter, the precipitate was once filtered and dried to obtain a thermoplastic polyurethane resin.

In a different reaction vessel, a dispersion liquid comprising 100 parts by mass of the obtained thermoplastic polyurethane resin, 1.5 parts by mass of the dispersion stabilizer (I), and 145.9 parts by mass of n-heptane is charged and mixed uniformly. Thus, a dispersion of a thermoplastic polyurethane resin was obtained.
Thereafter, a particulate polyurethane resin composition was produced and colored in the same manner as in Example 1.

Evaluation of Physical Properties The powdery properties of the particulate polyurethane resin compositions (hereinafter abbreviated as “powder”) obtained in each Example and each Comparative Example, that is, blocking and powder fluidity (angle of repose) were as follows. It was measured. Furthermore, after heating the metal mold | die with a wrinkle to 240 degreeC, each powder 300g was sprinkled on the metal mold | die, and after leaving still for 8 seconds, the excess powder which was not fuse | melted was wiped off. Subsequently, after leaving still at 60 degreeC for 60 second, it cooled with water and shape | molded the sheet | seat about 1 mm thick. And the physical property of the molded article was measured with the following method. The results are shown in Tables 1 to 3.

In addition, the average particle diameter of each powder was about 120-150 micrometers. The average particle size of each powder is determined by substituting a particle size analyzer (manufactured by Nikkiso Co., Ltd., model: MICROTRAC HRA) with n-heptane, and measuring the average particle size of the powder dispersed in n-heptane. Asked. The average particle size was a 50% cumulative percentage value in the volume fraction particle size distribution curve.
<Blocking>
100 g of each powder was allowed to stand at 40 ° C. for 24 hours, treated with a 40-mesh sieve, and the sieve residue ratio (%) was calculated.
<Powder fluidity (rest angle)>
The angle of repose (°) of the powder was measured by an injection method based on JIS R-9301-2.
<Melability (backside gloss)>
Using a gloss meter (manufactured by Nippon Denshoku Industries Co., Ltd., model: Gloss Meter VG2000), the gloss of the back surface (surface without wrinkles) of the sheet was measured. It was judged that the higher the gloss, the higher the meltability of the powder, and the lower the gloss, the more undissolved powder.
<Color unevenness (visual)>
Color unevenness on the surface of the sheet was evaluated according to the following criteria.
(Evaluation criteria)
“◯”: There is no color unevenness and it is uniform.
“Δ”: Color unevenness is slightly recognized.
“X”: Color unevenness is noticeable.
<Texture (folded wrinkle)>
The sheet was held for 20 seconds in a state where it was bent 180 °, and then returned to its original state and allowed to stand overnight. The bent portion was visually observed and evaluated according to the following criteria. When the sheet was hard, it tended to be broken and wrinkled.
(Evaluation criteria)
“O”: No creases are allowed.
“Δ”: Slight creases are observed.
“×”: Folding creases are clearly recognized.
<Crosslinkability (gel fraction)>
The sheet was pulverized, weighed about 4 g, and immersed in 500 ml of tetrahydrofuran (hereinafter abbreviated as THF) at 23 ° C. for 24 hours. Then, it filtered under reduced pressure using the aspirator. The undissolved substance in THF accumulated on the filter paper was washed with acetone, nitrogen was blown to sufficiently evaporate the acetone, and the mixture was allowed to stand in an oven at 40 ° C. for 20 hours under a nitrogen atmosphere. Thereafter, the undissolved material in THF was weighed. The mass of the undissolved material was divided by the mass of the sheet before being immersed in THF and multiplied by 100 to obtain the gel fraction (%).
<Tensile strength (elastic modulus) and elongation at break>
The sheet was subjected to a tensile test, and each elastic modulus (MPa) at break and the elongation (%) between the marked lines at break were measured. Specifically, in accordance with the method described in JIS K-6251, a test piece was punched with a JIS-4 dumbbell, and a tensile tester (Orientec Co., Ltd., trade name: Universal Tensile Tester RTA-500) The measurement was performed under the conditions of a tensile speed of 300 mm / min. In addition, about elongation at break,% of elongation was shown as a numerical value.
<Chemical resistance (alcohol resistance)>
A few drops of ethanol are dropped on the surface of the sheet with a 0.1 ml capacity dropoid, kept at 25 ° C. for 1 hour, then at 80 ° C. for 1 hour, and then the surface of the sheet is wiped with a cloth moistened with water. Was visually observed. The state where there was no change was classified as grade 5, and the state where the surface was completely dissolved was graded 1, and the interval was evaluated every 0.5 grade.
<Heat resistance (strength retention and appearance change)>
The molded skin was allowed to stand in a 120 ° C. hot air circulation oven for 500 hours, and then the tensile strength of the skin before and after the heat treatment was measured according to the above-described tensile strength and breaking elongation measurement methods. The tensile strength of the skin after the heat treatment was divided by that before the heat treatment and multiplied by 100 to obtain the strength retention (%).

  Further, using a gloss meter (manufactured by Nippon Denshoku Industries Co., Ltd., model: Gloss Meter VG2000), the gloss of the skinned surface of the skin after heat treatment was measured. It was judged that the higher the gloss, the more the appearance changed. The gloss of the skin before the heat treatment was 1.1.

In Tables 1 to 3, composition abbreviations are shown below.
U-2024: Polyester polyol (composition: 1,4-butanediol / 1,6-hexanediol / adipic acid, number average molecular weight 2000, manufactured by Mitsui Chemicals Polyurethanes)
U-2720: Polyester polyol (composition: ethylene glycol / 1,4-butanediol / adipic acid, number average molecular weight 2000, manufactured by Mitsui Chemicals Polyurethanes)
U-2710: Polyester polyol (composition: ethylene glycol / 1,4-butanediol / adipic acid, number average molecular weight 1000, manufactured by Mitsui Chemicals Polyurethanes)
2-EtHA: 2-ethylhexyl alcohol 1,6-HDA: 1,6-hexamethylenediamine 1,4-BAC: 1,4-bis (aminomethyl) cyclohexane St: styrene MMA: methyl methacrylate MSD: α-methylstyrene Dimer DPHA: Kayarad DPHA (mixture of dipentaerythritol hexaacrylate and dipentaerythritol pentaacrylate, manufactured by Nippon Kayaku Co., Ltd.)
TMP-3A: trimethylolpropane triacrylate MQ: p-methoxyphenol HQ: hydroquinone

Claims (10)

  A thermoplastic polyurethane resin synthesized in a non-aqueous dispersion medium, a vinyl monomer polymer, a thermally crosslinkable monomer, and 0.1 to 6 parts by mass of a polymerization inhibitor with respect to 100 parts by mass of the thermally crosslinkable monomer. A particulate polyurethane resin composition characterized by   The vinyl monomer polymer is obtained by a polymerization reaction of 35 to 70% by mass of an aromatic vinyl monomer and 30 to 65% by mass of an α, β-ethylenically unsaturated carboxylic acid alkyl ester. A particulate polyurethane resin composition.   The particulate polyurethane resin composition according to claim 1 or 2, wherein the vinyl monomer polymer is contained in an amount of 5 to 40 parts by mass with respect to 100 parts by mass of the thermoplastic polyurethane resin.   The particulate polyurethane resin composition according to any one of claims 1 to 3, wherein the thermally crosslinkable monomer is contained in an amount of 2 to 10 parts by mass with respect to 100 parts by mass of the thermoplastic polyurethane resin.   By blending a chain extender dispersion containing a chain extender, a non-aqueous dispersion medium and a dispersion stabilizer into an isocyanate group-terminated prepolymer in a non-aqueous dispersion medium, the thermoplastic polyurethane resin undergoes a chain extension reaction. It is obtained, The particulate polyurethane resin composition in any one of Claims 1-4 characterized by the above-mentioned.   The dispersion of the chain extender contains 10 to 300 parts by mass of the non-aqueous dispersion medium and 0.1 to 2 parts by mass of the dispersion stabilizer with respect to 100 parts by mass of the chain extender. The particulate polyurethane resin composition according to claim 5.   A molded article obtained by slush molding the particulate polyurethane resin composition according to any one of claims 1 to 6.   The molded product according to claim 7, wherein the molded product is an automobile interior product. A thermoplastic polyurethane resin is obtained by blending a chain extender dispersion containing a chain extender, a non-aqueous dispersion medium and a dispersion stabilizer into an isocyanate group-terminated prepolymer in a non-aqueous dispersion medium and subjecting it to a chain extension reaction. Synthesize,
In the non-aqueous dispersion medium, an aromatic vinyl monomer and an α, β-ethylenically unsaturated carboxylic acid alkyl ester are blended and polymerized to synthesize a vinyl monomer polymer.
A method for producing a particulate polyurethane resin composition, which comprises blending a thermally crosslinkable monomer and a polymerization inhibitor into the non-aqueous dispersion medium.   The dispersion of the chain extender contains 10 to 300 parts by mass of the non-aqueous dispersion medium and 0.1 to 2 parts by mass of the dispersion stabilizer with respect to 100 parts by mass of the chain extender. The manufacturing method of the particulate polyurethane resin composition of Claim 9.