JP3595482B2 - Polyurethane resin slush molding materials - Google Patents

Description

【００６５】
物性測定例２
物性測定例１と同様にして得た（Ｓ１）〜（Ｓ３）の各成形シートをモールド内にセットした状態でその上にウレタンフォーム形成成分［ＥＯチップドポリプロピレントリオール（数平均分子量５，０００）９５部、トリエタノールアミン５部、水２．５部、トリエチルアミン１部およびポリメリックＭＤＩ６１．５部からなる］を添加し発泡密着させ、（Ｓ１）〜（Ｓ５）の各表皮層を有するウレタンフォーム成形体を得た。これらの成形体を１２０℃の循風乾燥器内で５００時間熱処理した後、該成形体からウレタンフォームをとり除き、各成形シート（表皮層）について下記試験方法により性能試験を行った。その結果を表２に示す。
伸び率（２５℃、−３５℃）：ＪＩＳ−Ｋ６３０１に準じて測定した。
外観：下記評価基準で目視判定した。
○；変化無し、×；変化有り
【００６６】
【表２】

【００６７】
物性測定例３
物性測定例２で得た（Ｓ１）〜（Ｓ３）の各表皮層を有するウレタンフォーム成形体をそれぞれブラックパネル温度８３℃のカーボンアークフェードメーター内で４００時間処理した。処理後成形体からウレタンフォームをとり除き、各成形シート（表皮層）について下記試験方法により性能試験を行った。その結果を表３に示す。
伸び率（２５℃、−３５℃）：ＪＩＳ−Ｋ６３０１に準じて測定した。
外観：下記評価基準で目視判定した。
○；変化無し、×；変化有り
【００６８】
【表３】

【００６９】
【発明の効果】
本発明のポリウレタン樹脂系スラッシュ成形用材料は下記の効果を有する。
１．とくに耐光老化性および耐熱老化性等の耐久性に優れる成形体を得ることができる。
２．適度な硬度を有し、低温での柔軟性（ソフト感）に優れる成形体を得ることができる。
上記効果を奏することから本発明のスラッシュ成形用材料から得られる成型体は、インストルメントパネルをはじめ各種自動車内装材として特に有用である。また、表皮付きソファー等のインテリア家具など他の成形品への応用も可能である。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a slush molding material. More specifically, the present invention relates to a polyurethane resin-based slush molding material which provides a molded article having long-term durability under ultraviolet irradiation and high temperature.
[0002]
[Prior art]
In recent years, the slush molding method has been used for automotive interior materials, etc., because products having complicated shapes (undercut, deep drawing, etc.) can be easily molded, the thickness can be made uniform, and the material yield rate is good. It is widely used, and soft polyvinyl chloride (hereinafter, referred to as PVC) -based powder is mainly used for such a purpose (for example, JP-A-5-279485).
However, since the softened PVC contains a large amount of a low molecular weight plasticizer, there is a problem that the soft feeling disappears below the freezing point of the plasticizer. In addition, during long-term use, the plasticizer volatilizes to form an oil film (fogging) on the windshield of a vehicle, etc., and the transfer of the plasticizer to the surface of the molded product causes the matting effect and the softness to disappear. There was a problem of yellowing due to deterioration with time.
In order to solve the above problems and provide a soft feeling without using a large amount of a low-molecular weight plasticizer, those using a flexible thermoplastic polyurethane resin have been proposed (for example, JP-A-08-277341). Gazette).
However, even in this method, the thermoplastic polyurethane resin as the main resin has a wide molecular weight distribution, so that the resin itself contains a low molecular weight substance, and thus the resin surface softens during a long-term durability test under ultraviolet irradiation and high temperature. And deformed.
[0003]
[Problems to be solved by the invention]
An object of the present invention is to provide a slush molding material capable of obtaining a molded body such as an automobile instrument panel having long-term durability under ultraviolet irradiation and high temperature, in which the above-mentioned problems are improved. And
[0004]
[Means for Solving the Problems]
The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, have reached the present invention.
That is, in the present invention, the terminal is blocked with a polymer monol (a2) having a number average molecular weight of 200 or more, the number average molecular weight is 10,000 to 60,000, and the thermal softening start temperature is 120 to 200 ° C. A slush molding material comprising a thermoplastic polyurethane elastomer (A), a plasticizer (B), a compound (C) containing two or more radically polymerizable unsaturated groups in a molecule, and an additive if necessary.
[0005]
Examples of the thermoplastic polyurethane elastomer (A) in the present invention include an excess of an aliphatic diisocyanate (a1), a polymer monool (a2) having a molecular weight of 200 or more, and a polymer diol (a3) having a number average molecular weight of 500 to 10,000. ) And if necessary, an isocyanate group-terminated urethane prepolymer (a) derived from a low molecular weight diol (a4) and an aliphatic diamine (b).
[0006]
Examples of the aliphatic diisocyanate (a1) constituting the above (a) include (1) aliphatic diisocyanates having 2 to 18 carbon atoms (excluding carbon in the NCO group, the same applies hereinafter) [ethylene diisocyanate, tetramethylene diisocyanate, hexa Methylene diisocyanate (HDI), dodecamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, lysine diisocyanate, 2,6-diisocyanatomethylcaproate, bis (2-isocyanatoethyl) fumarate, bis (2-isocyanate) (Natoethyl) carbonate, 2-isocyanatoethyl-2,6-diisocyanatohexanoate, etc .; [2] alicyclic diisocyanate having 4 to 15 carbon atoms [isophorone diisocyanate (IPDI), dicyclohexylmethane-4,4 '- Isocyanate (hydrogenated MDI), cyclohexylene diisocyanate, methylcyclohexylene diisocyanate (hydrogenated TDI), bis (2-isocyanatoethyl) -4-cyclohexene, etc.]; {circle over (3)} araliphatic having 8 to 15 carbon atoms Diisocyanates [m- and / or p-xylylene diisocyanate (XDI), α, α, α ', α'-tetramethyl xylylene diisocyanate (TMXDI) and the like]; (4) Modified products of these diisocyanates (carbodiimide group, Modified diisocyanate having a uretdione group, a uretimine group, a urea group, and the like); and a mixture of two or more of these.
Of these, preferred are alicyclic diisocyanates, and particularly preferred are IPDI and hydrogenated MDI.
[0007]
Examples of the polymer monol (a2) include polyester monol, polyether monol, polyetherester monol, and a mixture of two or more thereof.
[0008]
Examples of the polyester monool include: (1) a low molecular weight diol and a condensation polymerization of a low molecular weight monol and a dicarboxylic acid or an ester-forming derivative thereof; and (2) a low molecular weight diol and a dicarboxylic acid or an ester forming derivative thereof. And condensation polymerization with a monocarboxylic acid having 2 to 6 carbon atoms [aliphatic monocarboxylic acid, aromatic monocarboxylic acid, etc.]; [3] Ring-opening polymerization of a lactone monomer using a low molecular weight monol as an initiator (4) those obtained by reacting a dicarboxylic anhydride and an alkylene oxide with a low molecular weight monol as an initiator; and a mixture of two or more thereof.
[0009]
Specific examples of the low molecular weight diol of the above (1) or (2) 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.), diols having a branched chain (propylene glycol, neopentyl glycol, 3-methyl-1,5-pentanediol, 2,2-diethyl-1,3) -Propanediol, 1,2-, 1,3- or 2,3-butanediol, etc.); a diol having a cyclic group [an alicyclic group-containing diol having 6 to 15 carbon atoms [1,4-bis ( Hydroxymethyl) cyclohexane, hydrogenated bisphenol A, etc.), and an aromatic ring-containing diol having 8 to 20 carbon atoms (m- or p-xylylene) Alcohols), oxyalkylene ethers of bisphenols (such as bisphenol A, bisphenol S and bisphenol F), oxyalkylene ethers of polynuclear phenols (such as dihydroxynaphthalene), bis (2-hydroxyethyl) terephthalate, etc .; Adducts (molecular weight less than 500) and mixtures of two or more of these.
[0010]
In the above and the following, the alkylene oxide is ethylene oxide (EO), propylene oxide (PO), 1,2-, 1,3-, 1,4- or 2,3-butylene oxide, styrene oxide, and having 5 carbon atoms. Α-Olefin oxide, epichlorohydrin, and a combination system of two or more thereof (block or random addition).
[0011]
Preferred low-molecular diols are aliphatic diols and diols containing alicyclic groups.
[0012]
Specific examples of the low molecular weight monol of the above (1), (3) or (4) include aliphatic monools having 1 to 8 carbon atoms [linear monools (methanol, ethanol, propanol, butanol, pentanol). , Hexanol, octanol, etc.), monools having a branched chain (isopropyl alcohol, neopentyl alcohol, 3-methyl-pentanol, etc.); monools having a cyclic group having 6 to 10 carbon atoms [monomers containing an alicyclic group] Ol (such as cyclohexanol), aromatic ring-containing monol (such as benzyl alcohol) and the like, and mixtures of two or more of these.
Preferred among these are aliphatic monols.
[0013]
Specific examples of the dicarboxylic acid or ester-forming derivative thereof of the above (1) or (2) include aliphatic dicarboxylic acids having 4 to 15 carbon atoms [succinic acid, adipic acid, sebacic acid, glutaric acid, azelaic acid, maleic acid, and the like. Acid, fumaric acid, etc.], aromatic dicarboxylic acids having 8 to 12 carbon atoms [terephthalic acid, isophthalic acid, etc.], their ester-forming derivatives [acid anhydrides, lower alkyl esters (dimethyl ester, diethyl ester, etc.), acids] And mixtures of two or more of these.
[0014]
Examples of the above-mentioned monocarboxylic acids (2) include aliphatic monocarboxylic acids having 2 to 8 carbon atoms [acetic acid, propionic acid, butyric acid, etc.], aromatic monocarboxylic acids having 7 to 10 carbon atoms [benzoic acid, etc.] and the like. And mixtures of two or more of the above.
[0015]
Examples of the lactone monomer of (3) include lactones having 4 to 12 carbon atoms, for example, γ-butyrolactone, γ-valerolactone, ε-caprolactone, and a mixture of two or more of these.
[0016]
Examples of the polyether monool include monools [for example, the above-described low molecular weight monool, monohydric phenols having 6 to 60 or more carbon atoms [phenol, cresol, xylenol, mono- or dialkyl (2 to 12 carbon atoms) phenol, Styrenated (1 to 5 mol) phenol, etc.] and an alkylene oxide.
[0017]
Of these, preferred are alkylene oxides added to aliphatic monols.
[0018]
As the polyetherester monool, in the polyester monool, instead of the raw material low molecular monool, the polyether monool or the low molecular monool or a low molar addition product of alkylene oxide of a monohydric phenol (molecular weight: 200) And those obtained by adding an alkylene oxide to the polyester monol.
[0019]
Among these high molecular weight monols (a2), preferred are polyester monols, and more preferable are low molecular weight monols and polycondensates of low molecular weight diols and dicarboxylic acids.
[0020]
The number average molecular weight of (a2) is usually 200 or more, preferably 500 to 3,000, more preferably 1,000 to 2,000. If the number average molecular weight is less than 200, the durability becomes insufficient.
Above and below, the number average molecular weight (hereinafter Mn) is a value calculated based on a calibration curve obtained from a molecular weight standard sample such as polystyrene using gel permeation chromatography (GPC).
[0021]
Examples of the polymer diol (a3) constituting (a) include polyester diol, polyether diol, polyether ester diol, and a mixture of two or more thereof.
[0022]
Examples of the polyester diol include (5) a low molecular diol and a dicarboxylic acid or an ester-forming derivative thereof [acid anhydride, lower alkyl (1 to 4 carbon atoms) ester, acid halide, etc.] or dialkyl carbonate (carbon number of alkyl group). (6) a product obtained by ring-opening polymerization of a lactone monomer using a low molecular diol as an initiator; and (7) a reaction between a dicarboxylic anhydride and an alkylene oxide using a low molecular diol as an initiator. And mixtures of two or more of these.
[0023]
Examples of the low molecular diol of the above (5), (6) or (7) include those exemplified as the raw material of the above (a2).
Of these, aliphatic diols and alicyclic group-containing diols are preferred.
[0024]
Specific examples of the dicarboxylic acid or ester-forming derivative thereof of the above (5) include those exemplified as the raw material of the above (a2).
[0025]
Examples of the lactone monomer of the above (6) include those exemplified as the raw material of the above (a2).
[0026]
Examples of the polyether diol include a compound having a structure in which an alkylene oxide is added to two hydroxyl group-containing compounds (for example, the low-molecular diol and the divalent phenol).
[0027]
Examples of the divalent phenols include bisphenols [bisphenol A, bisphenol F, bisphenol S, etc.], and monocyclic phenols [catechol, hydroquinone, etc.].
[0028]
[0029]
Of these, preferred are alkylene oxides added to dihydric phenols, and more preferred are those obtained by adding EO to dihydric phenols.
[0030]
As the polyetherester diol, those obtained by using the above-mentioned polyetherdiol in place of the low molecular weight diol as the raw material in the above-mentioned polyesterdiol, for example, one or more of the above-mentioned polyetherdiols and the dicarboxylic acid exemplified as the raw material of the above-mentioned polyesterdiol Alternatively, those obtained by condensation polymerization of at least one of the ester-forming derivatives thereof may be mentioned.
[0031]
Among these high molecular diols (a3), a preferable one is a polyester diol, and a more preferable one is a polycondensate of a low molecular diol and a dicarboxylic acid.
[0032]
The Mn of the (a3) is usually 500 to 10,000, preferably 800 to 5,000, and more preferably 1,000 to 3,000. If the number average molecular weight is less than 500, a sufficient soft feeling cannot be obtained, and if it exceeds 10,000, the desired strength is not exhibited.
[0033]
The method for producing (a2) and (a3) is not particularly limited, and (a2) and (a3) may be separately synthesized, or (a2) and (a3) may be simultaneously synthesized. . Preferred is a method for simultaneously synthesizing (a2) and (a3) [a method for producing a mixture of (a2) and (a3) in the presence of a low molecular weight monol or monocarboxylic acid when producing (a3)]. It is.
[0034]
In the present invention, the molar ratio of (a2) to (a3) constituting (a) is usually 1: (4 to 140), preferably 1: (5 to 70), and more preferably 1: (6 to 30). It is. Within this range, (A) having a low content of low molecular weight substances and having excellent durability can be obtained.
[0035]
As the low molecular diol (a4) optionally used together with the (a2) and (a3), the low molecular diol exemplified as the starting material of the above-mentioned ester diol can be used. Preferred as (a4) are aliphatic diols. The amount of (a4) used is usually 20% by weight or less, preferably 10% by weight or less based on the weight of (a3).
[0036]
When the isocyanate group-terminated urethane prepolymer (a) is formed, the molar ratio of (a1), (a2), (a3) and (a4) is such that (a2) is usually 0.01 mol per mol of (a1). To 0.5 mol, preferably 0.03 to 0.2 mol, (a3) is usually 0.2 to 0.7 mol, preferably 0.3 to 0.6 mol, and (a4) is usually 0 to 0 mol. 0.2 mol, preferably 0.05 to 0.15 mol. The molar ratio of (a1) to [(a2) + (a3) + (a4)] is usually 1: (0.2 to 0.8), preferably 1: (0.3 to 0.7). It is.
The content of the free isocyanate group of (a) is usually 1 to 10% by weight, preferably 3 to 6% by weight.
[0037]
The reaction temperature at the time of producing the urethane prepolymer (a) may be the same as the temperature usually employed at the time of urethane formation, and when a solvent is used, it is usually 20 ° C to 100 ° C. When not performed, the temperature is usually 20 ° C to 220 ° C, preferably 80 ° C to 200 ° C.
[0038]
In the above-mentioned prepolymerization reaction, a catalyst generally used for polyurethane can be used if necessary to accelerate the reaction. Examples of the catalyst include amine catalysts [triethylamine, N-ethylmorpholine, triethylenediamine, etc.] and tin catalysts [trimethyltin laurate, dibutyltin dilaurate, dibutyltin malate, etc.].
[0039]
[0040]
As the aliphatic diamine (b) used in the reaction with (a), an alicyclic diamine having 6 to 18 carbon atoms [4,4'-diamino-3,3'-dimethyldicyclohexylmethane, 4,4 ' -Diaminodicyclohexylmethane, diaminocyclohexane, isophoronediamine, etc.]; aliphatic diamine having 2 to 12 carbon atoms [ethylenediamine, propylenediamine, hexamethylenediamine, etc.]; araliphatic diamine having 8 to 15 carbon atoms [xylylenediamine, α , Α, α ', α'-tetramethylxylylenediamine, etc.] and mixtures of two or more of these. Of these, preferred are alicyclic diamines and aliphatic diamines, and particularly preferred are isophorone diamine and hexamethylene diamine.
[0041]
In the formation reaction of (A), the equivalent ratio of (b) to 1 equivalent of isocyanate group of urethane prepolymer (a) is usually 0.7 to 1.2 equivalents, preferably 0.8 to 1.1 equivalents, More preferably, it is 0.9 to 1.05 equivalent.
[0042]
As (A), those obtained by reacting the above (a) and (b) are preferable. In addition, (a) obtained by extending (a) with a diol (for example, the low-molecular diol); (A2) and, if necessary, (a3) obtained by reacting (one-shot) all at once in an NCO / OH equivalent ratio of 0.7 to 1.2 can be used.
[0043]
The method for producing the thermoplastic polyurethane elastomer (A) powder used in the present invention is not particularly limited, and examples thereof include the following methods.
{Circle around (1)} A method of obtaining a powder of (A) by pulverizing (A) in a block or pellet form by a freeze pulverization method, a freeze pulverization method or the like.
(2) A non-aqueous dispersion of (A) is formed in an organic solvent that does not dissolve (A) (eg, n-hexane, cyclohexane, n-heptane, etc.), and (A) is separated from the non-aqueous dispersion and dried. , (A) (for example, the method described in JP-A-04-255755).
{Circle around (3)} A water dispersion of (A) in water containing a dispersant (eg, polyvinyl alcohol, Na salt of styrene-methyl methacrylate-maleic acid copolymer, Na salt of diisobutylene-maleic acid alternating copolymer). (A) is separated from the aqueous dispersion and dried to obtain a powder of (A) (for example, the methods described in JP-A-07-133423 and JP-A-08-120041). .
Among these, the method of (3) is preferable because a powder having a desired particle size can be easily obtained without using a large amount of an organic solvent.
[0044]
Mn of said (A) is usually 10,000 to 60,000, preferably 15,000 to 55,000. If Mn is less than 10,000, a slush molded body having a desired breaking strength cannot be obtained. If it exceeds 60,000, the melt viscosity at the time of hot melting increases, and molding may be difficult.
The weight average molecular weight (Mw) of (A) is usually 50,000 to 200,000, preferably 60,000 to 100,000.
Mw / Mn indicating the molecular weight distribution of (A) is usually 2.4 or less, particularly preferably 2 or less from the viewpoint of heat resistance.
In the above and the following, Mw is a value calculated based on a calibration curve obtained from a molecular weight standard sample such as polystyrene using gel permeation chromatography (GPC) as in Mn.
[0045]
The thermal softening start temperature of (A) is usually 120 to 200 ° C, preferably 130 to 150 ° C. When the thermal softening start temperature is lower than 120 ° C., blocking between resin powders tends to occur, and when it exceeds 200 ° C., it may be difficult to obtain a molded product having a smooth surface. The thermal softening start temperature can be measured by, for example, thermomechanical analysis (TMA).
[0046]
Examples of the plasticizer (B) used in the present invention include phthalic esters [dibutyl phthalate, dioctyl phthalate, dibutylbenzyl phthalate, diisodecyl phthalate, etc.]; aliphatic dibasic acid esters [di-adipate- 2-ethylhexyl, 2-ethylhexyl sebacate etc.]; trimellitates [tri-2-ethylhexyl trimellitate, trioctyl trimellitate etc.]; fatty acid esters [butyl oleate etc.]; benzoates [polyethylene] Glycol (polymerization degree 2 to 10) dibenzoic acid ester, polypropylene glycol (polymerization degree 2 to 10) dibenzoic acid ester, etc.]; aliphatic phosphates [trimethyl phosphate, triethyl phosphate, tributyl phosphate, tri- 2-ethylhexylphosph Aromatic phosphates [triphenyl phosphate, tricresyl phosphate, trixylenyl phosphate, cresyl diphenyl phosphate, xyenyl diphenyl phosphate, 2-ethylhexyl diphenyl phosphate, tris (2 , 6-dimethylphenyl) phosphate and the like]; halogen aliphatic phosphates [tris (chloroethyl) phosphate, tris (β-chloropropyl) phosphate, tris (dichloropropyl) phosphate, tris (tribromoneopentyl) phosphate and the like]; A mixture of two or more of these may be mentioned.
Of these, preferred are benzoates, and particularly preferred are dibenzoates of polyethylene glycol.
[0047]
In the slush molding material of the present invention, the mixing ratio of (B) to (A) is such that the melt viscosity at the time of molding is appropriate and molding is easy, and (B) bleeds over time on the surface of the molded skin. From the viewpoint not to be performed, the amount is preferably 2 to 80 parts by weight, particularly preferably 5 to 50 parts by weight per 100 parts by weight of (A).
[0048]
As the compound (C) containing two or more radically polymerizable unsaturated groups in the molecule used in the present invention, (meth) acrylic acid and polyhydric alcohols (2 to 10 or more polyhydric alcohols. (The same applies hereinafter) [e.g., ethylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, etc.]; Esters with di- or hexavalent or higher polycarboxylic acids [eg diallyl phthalate, triallylic acid triallyl ester, etc.]; poly (meth) allyl ethers of polyhydric alcohols [eg pentaerythritol tri (meth) allyl ether] Etc.]; polyvinyl alcohols Ether [for example, ethylene glycol divinyl ether, etc.]; polyhydric alcohols Polypropylene ether-[such as ethylene glycol dipropionate propenyl ether, etc.] of; polyvinyl benzenes [e.g. divinylbenzene and mixtures of two or more thereof.
Among these, preferred are (meth) esters of acrylic acid and polyhydric alcohols, esters of allyl alcohol and polycarboxylic acids and polyallyl ethers of polyhydric alcohols in terms of radical polymerization rate, Particularly preferred are trimethylolpropane tri (meth) acrylate, pentaerythritol tetra (meth) acrylate and dipentaerythritol penta (meth) acrylate.
The number of unsaturated groups (non-conjugated double bonds) in one molecule of (C) is usually 2 to 10, preferably 3 to 6. If the number of functional groups is less than 2, the effect of improving durability is insufficient, and if it exceeds 10, the compound (C) has a high molecular weight, so that the viscosity becomes high and handling becomes difficult.
The (C) polymerizes the (C) itself by capturing radicals generated when the polyurethane elastomer (A) is degraded by light (ultraviolet light) or heat, and as a result, the slush molded article has excellent light aging resistance and heat resistance. It has the effect of providing long-term durability such as aging.
[0049]
The amount of (C) used in the present invention is preferably 0.1 to 10 parts by weight, particularly 0.5 to 8 parts by weight, per 100 parts by weight of (A) in order to obtain a slush molded article having excellent long-term durability. .
[0050]
The slush molding material of the present invention can optionally contain stabilizers, pigments and other additives as necessary.
[0051]
The stabilizer is not particularly limited, and known antioxidants and / or ultraviolet absorbers can be used. The amount of the stabilizer is usually 5 parts by weight or less, preferably 3 parts by weight or less per 100 parts by weight of (A). It is.
Examples of the antioxidant include phenol-based compounds [eg, 2,6-di-t-butyl-p-cresol, butylated hydroxyanisole, etc.]; bisphenol-based compounds [eg, 2,2′-methylenebis (4-methyl-6-t- Butylphenol) and the like]; and phosphorus-based [for example, triphenylphosphite, diphenylisodecylphosphite, and the like].
Examples of ultraviolet absorbers include benzophenones [eg, 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, etc.]; benzotriazoles [eg, 2- (2′-hydroxy-5′-methylphenyl) benzotriazole, etc. ]; Salicylic acid type [for example, phenyl salicylate and the like]; hindered amine type [for example, bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate and the like].
[0052]
The pigment is not particularly limited, and known organic pigments and / or inorganic pigments can be used. It is generally used in an amount of 5 parts by weight or less, preferably 0.01 to 3 parts by weight, per 100 parts by weight of (A). .
Examples of the organic pigment include an insoluble or soluble azo pigment, a copper phthalocyanine-based pigment, and a quinacridone-based pigment. Examples of the inorganic pigment include a chromate, a ferrocyan compound, and a metal oxide (titanium oxide, iron oxide, Zinc oxide, aluminum oxide, etc.), metal salts [sulfate (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.
The average particle size of the pigment is not particularly limited, but is usually 0.5 to 1 μm.
[0053]
Other additives include an antiblocking agent, a release agent, a crosslinking agent, a flame retardant, and the like. The amount of the other additives is usually 5 parts by weight or less, preferably 3 parts by weight or less, per 100 parts by weight of (A).
[0054]
The method for producing the slush molding material of the present invention is not particularly limited, and examples thereof include the following method.
{Circle around (1)} A method in which the powder of (A), (B), (C) and, if necessary, additives are mixed together by a mixing device.
{Circle around (2)} A method in which (B), (C) and, if necessary, additives are mixed in advance, and this is mixed with the powder of (A).
{Circle around (3)} A method in which (B), (C) and, if necessary, part or all of additives are contained in an arbitrary step of producing the powder of (A).
Among them, the method (2) is preferable from the viewpoint of simplifying the manufacturing process.
[0055]
The apparatus for producing the slush molding material of the present invention is not particularly limited, and a known powder mixing apparatus can be used.
Examples of the powder mixing device include a high-speed shear mixing device (for example, Henschel mixer (trade name)), a low-speed mixing device (for example, Nauta mixer, planetary mixer, etc.).
[0056]
The average particle size of the slush molding material of the present invention is 100 to 400 μm, preferably 1120 to 300 μm, and particularly preferably 130 to 200 μm. If the average particle size is less than 50 μm, the fluidity of the powder becomes poor, and the powder does not penetrate into the details of the mold during slush molding, making molding difficult. If it exceeds 400 μm, pinholes tend to occur in the molded skin.
The proportion of particles having a particle size of less than 100 μm is usually at most 20% by weight, preferably at most 10% by weight. If the content exceeds 20% by weight, dust is generated, the working environment is deteriorated, and the fluidity of the powder is deteriorated, so that the powder does not penetrate into the details of the mold at the time of slush molding and molding may be difficult.
Here, the average particle size is a value of a particle size of 50% by weight under the sieve measured by a particle size distribution measuring device such as [“TUBTEC”, manufactured by Resentech Co., Ltd.].
[0057]
The angle of repose is usually 35 ° or less, preferably 33 ° or less, and the spatula angle is usually 50 ° or less, preferably 40 ° or less. If the angle of repose and the angle of the spatula are outside the above ranges, the fluidity of the powder will be poor, and the powder may not enter into the details of the mold during slush molding, making molding difficult.
The method of measuring the angle of repose and spatula angle here is described in R.S. L. Caar; Chem. Eng. , Vol. 72, Jan. 18, p163 (1965) and the same Feb. 1, p69 (1965).
The angle of repose and the angle of spatula can be measured using, for example, “Powder Tester” manufactured by Hosokawa Micron Corporation.
[0058]
The slush molding material of the present invention is suitably used particularly for manufacturing automobile interior materials (eg, instrument panels, grab door covers, consoles, door trims, etc.).
[0059]
【Example】
Hereinafter, the present invention will be described in more detail by way of examples, but the present invention is not limited thereto. In the following description, "parts" indicates parts by weight and "%" indicates% by weight.
[0060]
Example 1
In a four-necked flask equipped with a stirring bar and a thermometer, 50 parts of polybutylene adipate monol having Mn of 1,000 (hydroxyl number: 56.1) and polybutylene adipate diol having Mn of 2,000 (hydroxyl number: 56) were placed. 780 parts of a mixture of 730 parts (molar ratio 1: 7.3) were added, and the mixture was heated to 110 ° C. under a reduced pressure of 3 mmHg to perform dehydration for 1 hour. Subsequently, 230 parts of IPDI, 36 parts of 1,4-butanediol and 1 part of a light stabilizer [“Irganox B75”, manufactured by Ciba Specialty Chemicals] were added, and the mixture was reacted at 110 ° C. for 10 hours, and a urethane having an isocyanate group at the terminal was added. A prepolymer was obtained. The free isocyanate content of the urethane prepolymer was 5.8%. This is designated as [Prepolymer 1].
After putting 222 parts of [Prepolymer 1] into a beaker, 726 parts of a dispersion liquid in which 3 parts of polyvinyl alcohol [“PVA-235” manufactured by Kuraray Co., Ltd.] is dissolved is added, and an ultra disperser (Yamato Scientific Co., Ltd.) is added. For 1 minute at 9,000 rpm.
This mixed solution was transferred to a four-necked flask equipped with a stirring bar and a thermometer, and 25 parts of isophoronediamine (IPDA) was charged with stirring, and the reaction was carried out at 50 ° C. for 10 hours. Next, the mixture was filtered and dried to prepare a resin powder (G1). Mn of (G1) was 50,000, Mw / Mn was 1.9, and thermal softening initiation temperature was 170 ° C.
100 parts of the above (G1), 25 parts of polyethylene glycol (degree of polymerization: 8) dibenzoic acid ester, 10 parts of dipentaerythritol pentaacrylate and 1 part of titanium oxide [“Taipec R-820”, manufactured by Ishihara Sangyo Co., Ltd.] The mixture was charged into a shell mixer and mixed at 200 rpm for 1 minute. After mixing, the mixture was aged at 100 ° C. for 1 hour, cooled to 40 ° C., and added with 1 part of an antiblocking agent (silica) [“Sylysia 310”, manufactured by Fuji Devison Chemical Co., Ltd.] to form a slush mold of the present invention. The material (S1) was obtained.
[0061]
Example 2
A four-necked flask equipped with a stir bar and a thermometer was charged with 25 parts of polyhexamethylene isophthalate monol having Mn of 500 (hydroxyl number 112.2) and polyhexene having Mn of 1,000 (hydroxyl number 112.2). 693 parts of a mixture consisting of 668 parts of methylene isophthalate diol (molar ratio 1: 13.36) were added, and the mixture was heated to 110 ° C. under a reduced pressure of 3 mmHg to perform dehydration for 1 hour. Subsequently, 332 parts of hydrogenated MDI and 1 part of a light stabilizer [“Irganox B75”, manufactured by Ciba Specialty Chemicals] were added, and the mixture was reacted at 100 ° C. for 5 hours to obtain a urethane prepolymer having a terminal isocyanate group. The free isocyanate content of the urethane prepolymer was 5.1%. This is designated as [Prepolymer 2].
Into a beaker, 220 parts of [Prepolymer 2] is added, and 750 parts of a dispersion liquid in which 3 parts of polyvinyl alcohol [“PVA-235”, manufactured by Kuraray Co., Ltd.] is dissolved is added, and Ultra Disperser (Yamato Scientific Co., Ltd.) is added. For 1 minute at 9,000 rpm.
This mixed solution was transferred to a four-necked flask equipped with a stirring bar and a thermometer, and 22 parts of IPDA was charged with stirring, and the reaction was carried out at 50 ° C. for 10 hours. Next, the mixture was filtered and dried to prepare a resin powder (G2). Mn of (G2) was 55,000, Mw / Mn was 1.8, and thermal softening initiation temperature was 190 ° C.
100 parts of the above (G2), 25 parts of polyethylene glycol (degree of polymerization 8) dibenzoic acid ester, 8 parts of trimethylolpropane triacrylate and 1 part of titanium oxide [“Taipec R-820”, manufactured by Ishihara Sangyo Co., Ltd.] The mixture was charged into a shell mixer and mixed at 200 rpm for 1 minute. After mixing, the mixture was aged at 100 ° C. for 1 hour, cooled to 40 ° C., and 1 part of cyclohexylmaleimide resin powder was added as a blocking inhibitor to obtain a slush molding material (S2) of the present invention.
[0062]
Comparative Example 1
730 parts of polybutylene adipate diol having Mn of 2,000 (hydroxyl number: 56.1) was charged into a four-necked flask equipped with a stirring rod and a thermometer, and heated to 110 ° C. under a reduced pressure of 3 mmHg for 1 hour. Dehydration was performed. Subsequently, 230 parts of IPDI, 36 parts of 1,4-butanediol and 1.0 part of a light stabilizer [“Irganox B75”, manufactured by Ciba Specialty Chemicals] were added, and the mixture was reacted at 110 ° C. for 10 hours to give an isocyanate group at the terminal. A urethane prepolymer was obtained. The free isocyanate content of the urethane prepolymer was 5.8%. This is designated as [Prepolymer 3].
After 222 parts of [Prepolymer 3] is charged into a beaker, 726 parts of a dispersion liquid in which 3 parts of polyvinyl alcohol [“PVA-235” manufactured by Kuraray Co., Ltd.] is dissolved is added, and Ultra Disperser (Yamato Scientific Co., Ltd.) is added. For 1 minute at 9,000 rpm.
This mixed solution was transferred to a four-necked flask equipped with a stirring rod and a thermometer, and 25 parts of IPDA and 1.1 parts of dibutylamine were added thereto with stirring, and the reaction was carried out at 50 ° C. for 10 hours. Next, the mixture was filtered and dried to prepare a resin powder (G3). Mn of this (G3) was 47,000, Mw / Mn was 2.6, and thermal softening initiation temperature was 170 ° C.
100 parts of the above (G3), 25 parts of polyethylene glycol dibenzoate, 10 parts of dipentaerythritol pentaacrylate, and 1 part of titanium oxide "Taipek R-820" manufactured by Ishihara Sangyo Co., Ltd.] are put into a hen shell mixer. Then, the mixture was mixed at 200 rpm for 1 minute. After mixing, the mixture was aged at 100 ° C. for 1 hour, cooled to 40 ° C., and 1 part of an antiblocking agent (silica) [“Sylysia 310”, manufactured by Fuji Devison Chemical) was added to obtain a comparative slush molding material (S3). Obtained.
[0063]
Physical property measurement example 1
Each of (S1) to (S3) obtained in Examples 1 and 2 and Comparative Example 1 was brought into contact with a mold heated to 220 ° C. for 10 seconds to remove the unmelted powder after hot melting and left at room temperature for 1 minute. After cooling, a water-cooled sheet was prepared. A performance test was performed on the obtained molded sheet by the following test method. Table 1 shows the results.
Breaking strength and elongation (25 ° C), low temperature breaking strength and elongation (-35 ° C),
Hardness: Measured according to JIS-K6301.
Appearance: Color unevenness on the sheet surface was visually judged according to the following evaluation criteria.
○: uniform, Δ: slight color unevenness can be confirmed, ×: color unevenness
[0064]
[Table 1]

[0065]
Physical property measurement example 2
Each of the molded sheets (S1) to (S3) obtained in the same manner as in the physical property measurement example 1 was set in a mold, and a urethane foam-forming component [EO-tipped polypropylene triol (number average molecular weight 5,000)] was placed thereon. 95 parts, 5 parts of triethanolamine, 2.5 parts of water, 1 part of triethylamine and 61.5 parts of polymeric MDI], and adhered by foaming to form a urethane foam having the respective skin layers (S1) to (S5). Got a body. After heat-treating these molded articles in a circulating air dryer at 120 ° C. for 500 hours, urethane foam was removed from the molded articles, and each molded sheet (skin layer) was subjected to a performance test by the following test method. Table 2 shows the results.
Elongation (25 ° C., −35 ° C.): Measured according to JIS-K6301.
Appearance: Visually evaluated according to the following evaluation criteria.
○: no change, ×: change
[0066]
[Table 2]

[0067]
Physical property measurement example 3
The urethane foam molded products having the respective skin layers (S1) to (S3) obtained in Physical Property Measurement Example 2 were each treated for 400 hours in a carbon arc fade meter at a black panel temperature of 83 ° C. After the treatment, the urethane foam was removed from the molded body, and each molded sheet (skin layer) was subjected to a performance test by the following test method. Table 3 shows the results.
Elongation (25 ° C., −35 ° C.): Measured according to JIS-K6301.
Appearance: Visually evaluated according to the following evaluation criteria.
○: no change, ×: change
[0068]
[Table 3]

[0069]
【The invention's effect】
The polyurethane resin-based slush molding material of the present invention has the following effects.
1. In particular, a molded article having excellent durability such as light aging resistance and heat aging resistance can be obtained.
2. A molded article having an appropriate hardness and excellent in flexibility (soft feeling) at a low temperature can be obtained.
Because of the above effects, a molded article obtained from the slush molding material of the present invention is particularly useful as an instrument panel and various automobile interior materials. Further, application to other molded articles such as interior furniture such as sofas with skins is also possible.

Claims (6)

Thermoplastic polyurethane elastomer having a number-average molecular weight of at least 200 and a polymer monool (a2) whose terminals are blocked, a number-average molecular weight of 10,000 to 60,000 and a thermal softening start temperature of 120 to 200 ° C A polyurethane resin-based slush molding material comprising (A), a plasticizer (B), a compound (C) containing two or more radically polymerizable unsaturated groups in a molecule, and if necessary, an additive. (A) is derived from an excess of an aliphatic diisocyanate (a1), the polymer monol (a2), a polymer diol (a3) having a number average molecular weight of 500 to 10,000 and, if necessary, a low molecular diol (a4). The slush molding material according to claim 1, which is a thermoplastic urethane elastomer obtained by reacting an isocyanate group-terminated urethane prepolymer (a) with an aliphatic diamine (b). The slush molding material according to claim 2, wherein (a2) is a polyester monool and (a3) is a polyester diol. The slush molding material according to claim 2 or 3, wherein the molar ratio of (a2) to (a3) is 1: (4 to 140). The slush molding material according to any one of claims 1 to 4, wherein the molecular weight distribution (Mw / Mn) of (A) is 2.4 or less. The slush molding material according to any one of claims 1 to 5, which is a powder having an average particle size of 100 to 400 µm and a content of particles having a particle size of less than 100 µm is 20% by weight or less.