JP2002332402A - Aqueous dispersion and polyurethane resin paste sol - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide polyurethane resin-plasticizer aqueous dispersion for produc ing a polyurethane resin paste sol with high productivity, eliminating a process of pulverizing the polyurethane resin, and scarcely broadening a particle diame ter distribution. SOLUTION: This polyurethane resin-plasticizer aqueous dispersion is obtained by dispersing a plasticizer phase containing polyurethane resin particles in an aqueous phase. The method for producing the paste sol from the aqueous dispersion is provided and the paste sol is obtained from the aqueous dispersion.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a polyurethane resin aqueous dispersion containing a plasticizer, a polyurethane resin paste sol, and a method for producing the same.

[0002]

2. Description of the Related Art A polyurethane resin paste sol such as an organosol or a plastisol using a polyurethane resin is prepared by producing an aqueous dispersion of a polyurethane resin, removing the polyurethane resin from the aqueous dispersion, drying and crushing the dispersion, and then adding a plasticizer. Was added.

[0003]

However, according to the conventional production method, it is necessary to separate and dry the water and the polyurethane resin, and during this drying, coalescence and agglomeration of the resin particles easily occur, and the particle diameter becomes large. Had to be crushed. These pulverizing processes not only require special equipment but also have to deal with fine powder, so that great care has to be taken in terms of the human body and the environment. In addition, it is difficult to sufficiently pulverize, and the particle size distribution tends to be widened, so that the physical properties of the final molded product have been reduced.

[0004]

Means for Solving the Problems The present inventors have made intensive studies to solve the above-mentioned problems, and as a result, have reached the present invention.
That is, in the present invention, a polyurethane resin-plasticizer aqueous dispersion (D) obtained by dispersing a plasticizer phase containing polyurethane resin particles in an aqueous dispersion medium, and a paste sol is produced from the aqueous dispersion (D). A method, a paste sol obtained from (D), and a polyurethane resin molded article comprising the paste sol.

[0005]

DETAILED DESCRIPTION OF THE INVENTION Polyurethane resin of the present invention
In the plasticizer aqueous dispersion (D), the polyurethane resin particles are contained in a plasticizer phase, and the plasticizer phase is dispersed in an aqueous medium. Here, "contained in the plasticizer phase" means that when (D) is separated into the plasticizer phase and the aqueous medium phase, at least 60% by weight or more, preferably 80% by weight or more of the polyurethane resin particles. Is contained in the plasticizer phase.

[0006] The polyurethane resin particles in the aqueous dispersion (D) of the present invention are not particularly limited as long as they are conventionally known polyurethane resin particles. The average particle size of the polyurethane resin particles is preferably 0.1 μm or more from the viewpoint of the fluidity of the paste sol, and is preferably 100 μm or less from the viewpoint of the rate of penetration of the plasticizer into the resin particles. More preferably, it is 1 to 50 μm, particularly preferably 2 to 30 μm. The average particle diameter is a number average particle diameter measured by a light scattering method. The polyurethane resin particles are preferably in the form of beads, and the practical sphericity of Wadell is preferably 0.7 to 1, more preferably 0.8 to 1, and particularly preferably 0.9 to 1. When the practical sphericity of Wadell is 0.7 or more, the viscosity of the aqueous dispersion (D) becomes sufficiently low. It is noted that the practical sphericity is preferably not in the above range for all the fine particles, but is preferably in the above range as an average value. The Wadell's practical sphericity is a value represented by (diameter of a circle equal to the projected area of a particle) ÷ (diameter of a circle having a minimum area circumscribing the projected image of the particle). It can be measured by image processing.

The average particle diameter of the plasticizer phase containing the polyurethane resin particles in (D) is preferably 0.2 μm or more from the viewpoint of the fluidity of the paste sol, and is preferably 500 μm or less from the viewpoint of dispersion stability of the dispersed particles. More preferably, it is 1 to 150 μm. The average particle diameter is a number average particle diameter measured by a light scattering method.

As the aqueous dispersion medium (E) constituting the aqueous dispersion (D) of the present invention, water or a mixture of water and a hydrophilic organic solvent can be used. Examples of the hydrophilic organic solvent include, for example, ester or ester ether solvents such as ethyl acetate, butyl acetate, methoxybutyl acetate, methyl cellosolve acetate, and ethyl cellosolve acetate; ether solvents such as ethyl cellosolve, butyl cellosolve, and propylene glycol monomethyl ether. A ketone solvent such as acetone, methyl ethyl ketone and methyl isobutyl ketone; methanol, ethanol, n- and i-propanol, n-, i- and t
Alcohol solvents such as butanol, propylene glycol and dipropylene glycol; heterocyclic compound solvents such as N-methylpyrrolidone; and mixtures of two or more thereof. Of these, preferred are water alone and 20% hydrophilic organic solvent in the entire dispersion medium.
It is a mixed solvent of not more than% by weight.

The polyurethane resin constituting the polyurethane resin particles is usually a resin obtained by polyaddition reaction between a polyisocyanate (a1) and an active hydrogen-containing compound.

(A1) includes diisocyanate and 3
Contains functional or higher polyfunctional isocyanates,
For example, carbon number (excluding carbon in NCO group, the same applies hereinafter)
6-20 aromatic polyisocyanate, 2-18 carbon atoms
Aliphatic polyisocyanate, alicyclic polyisocyanate having 6 to 15 carbon atoms, araliphatic polyisocyanate having 8 to 15 carbon atoms, and modified products of these polyisocyanates (urethane group, carbodiimide group, allophanate group, buret group Uretdione group, uretoimine group, isocyanurate group, oxazolidone group-containing modified product) and mixtures of two or more of these.

Specific examples of the aromatic polyisocyanate include, for example, 1,3- and / or 1,4-phenylene diisocyanate, 2,4- and / or 2,6
-Tolylene diisocyanate (TDI), crude TDI,
2,4'- and / or 4,4'-diphenylmethane diisocyanate (MDI), 4,4'-diisocyanatobiphenyl, 3,3'-dimethyl-4,4'-diisocyanatobiphenyl, 3,3 '-Dimethyl-4,4'-
Diisocyanatodiphenylmethane, crude MDI [crude diaminodiphenylmethane [condensation product of formaldehyde and aromatic amine (aniline) or a mixture thereof;
A mixture of diaminodiphenylmethane and a small amount (for example, 5 to 20% by weight) of a trifunctional or higher polyamine]; a polyaryl polyisocyanate], 1,5-
Naphthylene diisocyanate, 4,4 ', 4 "-triphenylmethane triisocyanate, m- and p-isocyanatophenylsulfonyl isocyanate.

Specific examples of the above aliphatic polyisocyanate include, for example, ethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate (HDI), dodecamethylene diisocyanate,
6,11-undecane triisocyanate, 2,2,4
-Trimethylhexamethylene diisocyanate, lysine diisocyanate (2,6-diisocyanatomethylcaproate), bis (2-isocyanatoethyl) fumarate, bis (2-isocyanatoethyl) carbonate,
-Isocyanatoethyl-2,6-diisocyanatohexanoate.

Specific examples of the alicyclic polyisocyanate include, for example, isophorone diisocyanate (IPD
I), dicyclohexylmethane-4,4'-diisocyanate (hydrogenated MDI), cyclohexylene diisocyanate, methylcyclohexylene diisocyanate, bis (2-isocyanatoethyl) -4-cyclohexene-
1,2-dicarboxylate, 2,5- and / or 2,6-norbornane diisocyanate.

Specific examples of the araliphatic polyisocyanate include m- and / or p-xylylene diisocyanate and α, α, α ′, α′-tetramethyl xylylene diisocyanate.

Examples of the modified polyisocyanate include modified MDI (urethane-modified MDI, carbodiimide-modified MDI, trihydrocarbylphosphate-modified MDI), urethane-modified TDI, and buret-modified HD.
I, isocyanurate-modified HDI, polyisocyanate-modified products such as isocyanurate-modified IPDI, and mixtures of two or more of these [for example, a combination of modified MDI and urethane-modified TDI (isocyanate group-containing prepolymer)].

Among these, preferred are aliphatic and alicyclic polyisocyanates which are favorable in that they are less discolored by aging, especially HDI, IPDI, hydrogenated M.
DI.

The active hydrogen-containing compound includes a low molecular weight polyfunctional active hydrogen containing compound (a2) and a high molecular weight polyol (a
3) is included.

(A2) includes a low molecular polyol (a2)
1) and low molecular weight polyamines (a22).

As (a21), the OH equivalent [number average molecular weight per hydroxyl group (based on GPC measurement; the same applies hereinafter)]
Is less than 300 (preferably 30 to 250) and a polyol having 2 to 10 valences or more (preferably 2 to 3 valences) can be used. Specific examples of (a21) include dihydric alcohols such as aliphatic diols [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.) and a diol having a cyclic group [for example, those described in JP-B-45-1474; 1,4-bis (hydroxymethyl) cyclohexane, m- Or p-xylylene glycol], dihydric phenol [bisphenol A
(Poly) oxyalkylene ether (alkylene group having 2 to 4 carbon atoms) and the like]; trihydric to dihydric or higher polyhydric alcohols, for example, alkane polyols (glycerin, trimethylolpropane, pentaerythritol, sorbitol, etc.) And their intermolecular or intramolecular dehydrates [dipentaerythritol, polyglycerin (degree of polymerization 2 to 8), sorbitan, etc.], saccharides and their derivatives (glycosides) (sucrose, methyl glucoside, etc.); Alkylene oxide [AO
Abbreviation. 2 to 10 or more carbon atoms, for example, those mentioned in the production of (a32) described below] low-molar adducts (1 to 15 additional moles); and mixtures of two or more of these. Of these, preferred are aliphatic diols, and more preferred are 1,4-butanediol and neopentyl glycol.

(A22) contains a diamine having an amine equivalent (number average molecular weight per active hydrogen atom-containing amino group) of less than 300 (preferably 30 to 250) and a trifunctional or higher polyfunctional amine; Polyamines corresponding to (a1) [where the isocyanate groups of (a1) are replaced by amino groups] are included. Specifically, diamines such as aliphatic diamines [ethylenediamine, hexamethylenediamine, etc.], alicyclic diamines [4,4′-
Diamino-3,3'-dimethyldicyclohexylmethane, 4,4'-diamino-3,3'-dimethyldicyclohexyl, diaminocyclohexane, isophoronediamine, etc., aromatic diamine [diethyltoluenediamine], araliphatic diamine [xyli Range amine,
α, α, α ′, α′-tetramethylxylylenediamine, etc.], heterocyclic diamines (eg, piperidine); trifunctional or higher polyfunctional amines such as polyalkylene (C 2-6) polyamines ( Diethylenetriamine,
Triethylenetetramine and the like; polyphenylmethanepolyamine (such as a condensation product of formaldehyde and aniline); and a mixture of two or more thereof. Of these, preferred are alicyclic diamines and aliphatic diamines, and particularly preferred are isophorone diamine and hexamethylene diamine.

The polymer polyol (a3) includes OH
Polyols having an equivalent weight [number average molecular weight per hydroxyl group] of 300 or more (preferably 300 to 10,000) and having a valency of 2 to 4 or more (preferably 2 to 3) can be used. (A3) includes a polyester polyol (a3
1), polyether polyol (a32), and a mixture of two or more thereof.

Examples of (a31) include condensation-based polyester polyol (a311) (polycondensation of polyol and polycarboxylic acid), polylactone polyol (a312) (ring-opening polymerization of lactone monomer using polyol as initiator) Obtained by ring-opening polymerization of alkylene (C2-4) carbonate (ethylene carbonate, propylene carbonate, etc.) using polyol as an initiator, or by polycondensation of polyol or bisphenol with phosgene And a mixture of two or more of these.

(A311), (a312) and (a3
As the polyol in 13), at least one of a low molecular polyol [for example, (a21)] and / or a polyether polyol [for example, (a32)] can be used.

The polycarboxylic acids in (a311) include polycarboxylic acids and their ester-forming derivatives. Specific examples include aliphatic polycarboxylic acids [polycarboxylic acids having 2 to 6 functional groups and 3 to 30 carbon atoms, such as succinic acid, glutaric acid, maleic acid, fumaric acid, adipic acid, azelaic acid, sebacic acid, and hexahexaic acid. Hydrophthalic acid, etc.], aromatic polycarboxylic acids [polycarboxylic acids having 2 to 6 functional groups and 8 to 30 carbon atoms, for example, phthalic acid, isophthalic acid, terephthalic acid, tetrabromophthalic acid, tetrachlorophthalic acid, trimellitate Acid, pyromellitic acid, etc.]; these ester-forming derivatives [acid anhydride, lower alkyl (C1-4) ester (dimethyl ester, diethyl ester, etc.), acid halide (acid chloride, etc.) etc .: For example, maleic anhydride Acid, phthalic anhydride, dimethyl terephthalate, etc.]; and a mixture of two or more of these. Preferred among these are aliphatic polycarboxylic acids.

Examples of the lactone monomer in (a312) include lactones having 3 to 17 (preferably 4 to 12) carbon atoms, such as γ-butyrolactone, ε-caprolactone, δ-valerolactone, and mixtures of two or more of these. Can be

(A32) includes those having a structure in which an alkylene oxide (hereinafter abbreviated as AO) is added to a compound having two or more active hydrogen atoms.

Examples of the compound having an active hydrogen atom include low molecular weight polyols (for example, the above (a21)); dihydric phenols (for example, bisphenols (bisphenol A, bisphenol F, bisphenol S, etc.), monocyclic phenols (catechol) , Hydroquinone, etc.)];
Amines [Primary monoamines such as alkyl or alkenylamine (C1-20), aniline, alkanolamine (C2-4 of hydroxylalkyl group)
(Such as the terminating agents described below), polyamines such as (a22), heterocyclic polyamines such as piperazine,
Aminoalkyl (2-4 carbon atoms) piperazine (such as aminoethylpiperazine)].

As AO, ethylene oxide (hereinafter abbreviated as EO), propylene oxide (hereinafter abbreviated as PO), 1,2-, 1,3-, 1,4- and 2,3-butylene oxide, styrene oxide, Carbon number 5-1
Zero or more α-olefin oxides, epichlorohydrin and combinations of two or more thereof (block and / or random addition).

Among these, preferred are those obtained by adding AO (especially PO) to a low molecular polyol (especially aliphatic diol).

The production of the polyurethane resin can be carried out by a usual method, in which the active hydrogen-containing compound and (a1) are all reacted at once (one-shot method), and a part of these reaction components is prepared in advance. A method in which the reaction is carried out and a multistage reaction is carried out via an isocyanate group or hydroxyl group-terminated urethane prepolymer (a) (prepolymer method), and the like. Preferred is a prepolymer method, particularly a method in which an isocyanate group-terminated urethane prepolymer (a) is reacted with an elongating agent and, if necessary, a terminator and a crosslinking agent.

The isocyanate group-terminated urethane prepolymer (a) is preferably formed by reacting (a1) with (a3) and, if necessary, (a2). At this time, the equivalent ratio of (a1) to (a2) and (a3) is (a1)
1) With respect to 1 equivalent, (a2) is usually 0 to 0.2 equivalent, preferably 0.05 to 0.10 equivalent, and (a3) is usually 0.1 equivalent.
It is 1 to 0.7 equivalent, preferably 0.2 to 0.6 equivalent. Further, the isocyanate group content of (a) (hereinafter referred to as NCO)
%) Is usually 0.5 to 10% by weight, preferably 1.
5 to 6% by weight.

Examples of the extender include the diols mentioned in (a21) above, the diamines mentioned in (a22), and ketimine compounds thereof, for example, the above amines and ketones having 3 to 8 carbon atoms [acetone, methyl ethyl ketone, methyl isobutyl. Ketone (hereinafter abbreviated as MIBK)] and the like.
And water. Preferred are ketimine compounds.

Examples of the crosslinking agent include the polyhydric alcohols mentioned in (a21) and the polyfunctional amines (diethylenetriamine, triethylenetetramine, etc.) mentioned in (a22).

Examples of the terminator include monoamines having one or two hydroxyalkyl groups having 2 to 4 carbon atoms and aliphatic monoamines having no hydroxyl group.

Examples of the monoamine having one or two hydroxyalkyl groups include monoalkanolamines [monoethanolamine, monopropanolamine, etc.]; dialkanolamines [diethanolamine, dipropanolamine, etc.] and mixtures of two or more thereof. Is mentioned. Of these, preferred are dialkanolamines, and particularly preferred are diethanolamine and dipropanolamine. [In some cases, when the isocyanate group is present in an excess equivalent to the amino group, the hydroxyl group also participates in the reaction with the isocyanate group and acts as an extender and a crosslinking agent. ]

As the aliphatic monoamine having no hydroxyl group, an alicyclic monoamine [(mono- and di-
Cycloalkyl (C5-18) amines such as cyclopentylamine, cyclohexylamine and the like], aliphatic monoamines [mono- and di-alkyl or alkenyl (C1-20) amines such as methylamine,
Ethylamine, propylamine, butylamine, octylamine, 2-ethylhexylamine, nonylamine,
Oleylamine, N-methylbutylamine, diethylamine, dibutylamine, etc.] and mixtures of two or more of these. Of these, preferred are aliphatic monoamines having no hydroxyl group, and particularly preferred are butylamine, octylamine, 2-ethylhexylamine and dibutylamine.

The charging ratio of the elongating agent, the terminating agent and the crosslinking agent to the urethane prepolymer (a) is appropriately selected within a range for forming a polyurethane resin having a predetermined number average molecular weight. For example, the equivalent ratio of the elongating agent to 1 equivalent of the isocyanate group in (a) is preferably 0.05 to 1.5 equivalents, and more preferably 0.1 to 1.2 equivalents. Further, the equivalent ratio of the terminator is preferably 0 to 0.4 equivalent, more preferably 0.05 to 0.3 equivalent, and the equivalent ratio of the crosslinking agent is preferably 0 to 0.4 equivalent, more preferably. Is 0.02 to 0.2 equivalent. Further, the total equivalent ratio of the elongator, the terminator, and the crosslinking agent to 1 equivalent of the isocyanate group in (a) is preferably 0.1 to 2.3 equivalents, and more preferably 0.27 to 1.7 equivalents. .

The number average molecular weight of the polyurethane resin is usually 1
000 or more, preferably 15,000 to 1,000
000. Further, the terminal group of the polyurethane resin is usually a hydroxyl group or an amino group, not an isocyanate group.

In the present invention, the aqueous polyurethane resin dispersion (A) may be produced by a method of obtaining an aqueous dispersion simultaneously with a polyurethane resin formation reaction (chain elongation reaction, etc.), or an aqueous dispersion of a dried polyurethane resin powder. And a method of dispersing the mixture in a medium. Among these, a method of obtaining an aqueous dispersion at the same time as the reaction of forming the polyurethane resin is preferred. Specific examples include a method of forming an aqueous dispersion of a polyurethane resin in water containing a dispersant (for example, methods described in JP-A-07-133423 and JP-A-08-120041).

The above method comprises the steps of: reacting an isocyanate group-terminated urethane prepolymer (a) with an elongating agent and, if necessary, a terminating agent and a crosslinking agent in the above (E) in the presence of a dispersing agent, to form an aqueous resin fine particle. Methods for obtaining the dispersion are included. For example, a production method in which (a) and an elongating agent are dispersed by a dispersing machine in (E) containing a dispersing agent; (a) an elongating agent, and if necessary, a terminating agent, a crosslinking agent, and a dispersing agent. (E), a method of dispersing with a dispersing machine; (a) a method of dispersing with a dispersing machine in (E) containing a dispersing agent, an elongating agent, and if necessary, a terminator and a crosslinking agent. No.

Examples of the dispersant used include anionic, cationic, nonionic and amphoteric surfactants, polymeric dispersants, and combinations thereof.

Examples of the anionic surfactant include those having 6 carbon atoms.
Ether carboxylic acid having a hydrocarbon group of from 24 to 24 or a salt thereof [(poly) oxyethylene (polymerization degree = 1 to 10)
0) Sodium lauryl ether acetate], having 6 to 6 carbon atoms
Sulfate or ether sulfate having 24 hydrocarbon groups or a salt thereof [sodium lauryl sulfate, (poly) oxyethylene (degree of polymerization = 1 to 100)
Sodium lauryl sulfate, (poly) oxyethylene (polymerization degree = 1-100) triethanolamine lauryl sulfate, (poly) oxyethylene (polymerization degree = 1-100) coconut oil fatty acid sodium monoethanolamide sulfate, etc.], carbon number 6 A sulfonate having 1 to 24 hydrocarbon groups such as sodium dodecylbenzenesulfonate, a sulfosuccinate having 1 or 2 hydrocarbon groups having 8 to 24 carbon atoms, and a hydrocarbon group having 8 to 24 carbon atoms. A phosphoric acid ester or ether phosphoric acid ester or a salt thereof [sodium lauryl phosphate, (poly) oxyethylene (degree of polymerization = 1 to 100), sodium lauryl ether phosphate, etc.], and a hydrocarbon group having 8 to 24 carbon atoms. Fatty acid salts [sodium laurate, triethanolamine laurate, etc.] and Acylated amino acid salts [coconut oil fatty acid methyl taurine sodium having a hydrocarbon group having 8 to 24 carbon atoms, coconut oil fatty acid sarcosine sodium,
Coconut fatty acid sarcosine triethanolamine, N-coconut fatty acid acyl-L-glutamate triethanolamine, N-coconut fatty acid acyl-L-glutamate sodium, lauroylmethyl-β-alanine sodium, etc.].

Examples of the nonionic surfactant include an aliphatic alcohol (C8 to C24) alkylene oxide (C2 to C8) adduct (degree of polymerization = 1 to 100) and a polyvalent (2 to C2).
(Valent to 10 or more) alcohol fatty acid (C8 to C24) ester [glycerin monostearate, sorbitan monolaurate, etc.], fatty acid (C8 to C2)
4) Alkanolamide [1: 1 type coconut oil fatty acid diethanolamide, 1: 1 type lauric acid diethanolamide, etc.], (poly) oxyalkylene (2-8 carbon atoms, polymerization degree = 1-100) alkyl (1 carbon atom) -22) phenyl ether, (poly) oxyalkylene (2-8 carbon atoms,
Polymerization degree = 1 to 100) alkyl (8 to 24 carbon atoms) amine and alkyl (8 to 24 carbon atoms) dialkyl (1 to 6 carbon atoms) amine oxide [lauryl dimethylamine oxide and the like].

As the cationic surfactant, quaternary ammonium salt type [stearyltrimethylammonium chloride, behenyltrimethylammonium chloride, distearyldimethylammonium chloride, aminopropylethyldimethylammonium ethyl sulfate lanolin fatty acid, etc.], amine salt type [ Stearic acid diethylaminoethylamide lactate, dilaurylamine hydrochloride, oleylamine lactate, etc.].

Examples of the amphoteric surfactant include betaine-type amphoteric surfactants [coconut oil fatty acid amidopropyldimethylaminoacetic acid betaine, lauryldimethylaminoacetic acid betaine, 2-alkyl-N-carboxymethyl-N-hydroxyethylimidazolinium betaine. , Laurylhydroxysulfobetaine, lauroylamidoethylhydroxyethylcarboxymethylbetaine sodium hydroxypropylphosphate, etc.), amino acid type amphoteric surfactant [β
-Sodium laurylaminopropionate].

Examples of the polymeric dispersant include polyvinyl alcohol, starch and derivatives thereof, cellulose derivatives such as carboxymethylcellulose, methylcellulose and hydroxyethylcellulose; carboxyl group-containing (co) polymers such as sodium polyacrylate; -133423 and JP-A-08-1200
No. 41, a polymeric dispersant having a urethane bond or an ester bond [eg, a polycaprolactone polyol and a polyether diol linked by a polyisocyanate] can be used. The number average molecular weight of these polymeric dispersants is usually 3,000 to 1,
00000, preferably 5,000 to 100,00
0.

Preferred among these dispersants are:
Anionic surfactants, nonionic surfactants and polymeric surfactants are more preferred, and more preferred are anionic surfactants and polymeric dispersants having a urethane bond or an ester bond described in the above publication. .

The amount of the dispersant to be used is generally 0.1 to 15% (hereinafter, unless otherwise specified,% represents% by weight), preferably 0.2 to 8%, based on the solid content of the resin. . Also,
The dispersant is preferably 0.01 to 10% by weight of water.
%, More preferably 0.1 to 5%, and 0.01 to 5%.
If it is 10%, resin fine particles having a preferable average particle diameter are easily obtained. The amount of the dispersant solution composed of the dispersant and water based on the weight of (a) is preferably 50 to 1,000.
%, More preferably 100 to 1,000%. 5
If it is 0 to 1,000%, the dispersion state of (a) tends to be good, and resin fine particles having a preferable average particle diameter are easily obtained. If necessary, reduce the viscosity of (a) by 40 to 10
It may be heated to 0 ° C. Also, ester solvents (ethyl acetate, butyl acetate, etc.), ketone solvents (acetone, methyl ethyl ketone, MIBK, etc.), chlorine solvents (dichloromethane, dichloroethane, trichloroethane, etc.)
And / or 50% by weight or less of an aromatic solvent (toluene, xylene, etc.) based on (a) may be added.

As a method for the above dispersion in water, a known disperser such as a high-speed shearing type, a friction type, a high-pressure jet type, or an ultrasonic type can be preferably used. Among these, a more preferable system is a high-speed shearing system. When a high-speed shearing disperser is used, the rotation speed is preferably 1,000
~ 30,000 rpm, more preferably 2,000 ~
It is 10,000 rpm. The dispersion time is preferably 0.1 to 5 minutes. If the number of rotations and the dispersion time are within these ranges, resin fine particles having a preferable average particle size are easily obtained.

The reaction time of (a) with the elongating agent, the terminating agent and the crosslinking agent is not particularly limited, and may be appropriately selected depending on the reactivity and the reaction temperature. For example, when the reaction temperature is 30 ° C., it is usually 1 hour to 40 hours, preferably 5 hours to 20 hours. In the production method of the present invention, the reaction temperature is usually 0 to 80 ° C, preferably 20 to 60 ° C.

The number average particle diameter of the resin particles of the aqueous polyurethane resin dispersion (A) in the present invention is preferably 0.1 to 100 μm, similar to the number average particle diameter of the polyurethane resin particles in the above (D). Preferably 1 to 5
0 μm, particularly preferably in the range of 2 to 30 μm. The resin concentration in (A) is preferably 10 to 9%.
5%, more preferably 20-90%.

As the plasticizer (B) constituting the plasticizer phase in the present invention, conventionally known plasticizers can be used, and the following are exemplified. Phthalates [dibutyl phthalate, dioctyl phthalate, butylbenzyl phthalate, diisodecyl phthalate, etc.]; Aliphatic dibasic esters [di-2-ethylhexyl adipate, 2-ethylhexyl sebacate, etc.]; trimellitic acid Ester [tri-2-ethylhexyl trimellitate etc.]; Phosphate ester [tri-2-ethylhexyl phosphate, tricresyl phosphate, 2-ethylhexyl diphenyl phosphate etc.]; Polyalkyl ether benzoate diester [polyethylene glycol benzoate] Polyester plasticizer (weight average molecular weight 800 to 10,000) [aliphatic dibasic acid / aliphatic diol polycondensate (eg, adipic acid / 1,4-butylene glycol polycondensation) Thing, horse mackerel Acid / 1,6-hexylene glycol polycondensate, etc.] and mixtures of two or more thereof, with phthalic acid esters, phosphoric acid esters, polyalkyl ether benzoic acid diesters and polyester plasticizers being preferred. It is.

The (D) of the present invention comprises an aqueous dispersion (A) so that polyurethane resin particles can be contained in the plasticizer phase.
It can be produced by mixing a plasticizer (B). In this case, a method of adding (B) while stirring (A), a method of adding (A) while stirring (B),
A method of stirring after mixing (A) and (B) is exemplified. Among these, a method of adding (B) while stirring (A) and a method of adding (A) while stirring (B) are preferable. The rotation speed and the stirring time of the stirring are not particularly limited. For example, the rotation speed is preferably 300 to 50,000 rpm, more preferably 2,000 to 10,000 rpm, and the stirring time is preferably 0.1 to 25 minutes, more preferably 3
10 minutes. The temperature during the stirring step needs to be a temperature at which the polyurethane resin particles do not swell and dissolve in the plasticizer (B). Such a temperature varies depending on the composition of the polyurethane resin particles and the type of the plasticizer (B), but is preferably from 10 ° C to 50 ° C, more preferably from 20 ° C to 35 ° C.

The content of the polyurethane resin in (D) of the present invention is preferably 20 to 90% by weight, more preferably 30 to 85% by weight, based on the total weight of the polyurethane resin and the plasticizer (B). . If it is 90% or less, the urethane resin particles present in the aqueous phase can be sufficiently transferred to the plasticizer side, and if it is 20% or more, the concentration of the resin particles becomes high and a high concentration can be used. Also,
In (D), the total concentration of the resin component and the plasticizer is preferably from 13 to 90%, more preferably from 15 to 80%. The viscosity of (D) at 25 ° C. is preferably 30 to 10,
000 mPa · s.

The polyurethane resin paste sol of the present invention is obtained by separating and removing the aqueous dispersion medium from (D).

As a method for producing the paste sol of the present invention, the aqueous dispersion medium is separated and removed from (D) by a method based on stationary separation, centrifugation, addition of a phase separation agent, adsorption separation, or a combination thereof. A method for obtaining a sol is exemplified. The stationary separation is preferably performed at a temperature of 15 to 35 ° C. In addition, centrifugation uses a centrifuge, and the temperature is 15 to
It is better to carry out at 25 ° C. Among these, the preferred method is a method by adding a phase separating agent in that the separation speed is high and other devices need not be used.

Examples of the phase-separating agent include the aforementioned anionic, cationic, nonionic and amphoteric surfactants, and high molecular surfactants. Among these, preferred are anionic surfactants, and more preferred are those represented by the following general formula (1). RO- (QO) _n -SO ₃ M (1) wherein R is a hydrocarbon group having 6 to 30 carbon atoms, and Q is 2 carbon atoms.
~ 4 alkylene groups, M is a cation, n is 5-600,
Preferably 10 to 550, more preferably 20 to 50
It is an integer of 0.

In the general formula (1), R represents an aliphatic hydrocarbon group having 6 to 30 carbon atoms [for example, a linear or branched alkyl group (n-hexyl group, n- and i-heptyl group, 2-ethylhexyl group) Groups, n- and i-octyl groups, n- and i-nonyl groups, n- and i-decyl groups, n- and i-undecyl groups, n- and i-dodecyl groups, tridecyl groups, tetradecyl groups, pentadecyl groups , Hexadecyl group and eicosyl group), linear and branched alkenyl groups (such as 1-hexenyl group, 1-octenyl group, 1-decenyl group and 1-dodecenyl group), cycloalkyl groups (such as cyclohexyl group and cycloheptyl group) Etc.], an aromatic hydrocarbon group having 6 to 30 carbon atoms [for example, a phenyl group, an alkylaryl group (o, m or p-methylphenyl Nyl group, m, p-dimethylphenyl group, o, o-dimethylphenyl group, o, m or p-ethylphenyl group, pn-butylphenyl group, p-octylphenyl group, p-nonylphenyl group, etc.) , Aralkyl groups (such as benzyl and phenethyl groups), substituted aralkyl groups (such as o, m or p-methylbenzyl group, pn-butylphenethyl group), styrylphenyl groups (such as mono, di and tristyrylphenyl groups) And benzylphenyl groups (such as mono, di and tribenzylphenyl groups). Of these, an alkyl group is preferable, and an alkyl group having 12 to 18 carbon atoms is more preferable.

Q is an alkylene group having 2 to 4 carbon atoms,
Examples include an ethylene group, a propylene group, and a 1,2-butylene group. Q forms an oxyalkylene group together with oxygen, and when a plurality of oxyalkylene groups are present, they may be the same or different. Preferred is an oxyethylene group and an oxypropylene group, or a combination of an oxyethylene group and an oxypropylene group (random or block addition), and particularly preferably-(QO) _n -is represented by the following general formula (2). Things. _{- (C 3 H 6 O)} k - (C 2 H 4 O) m - (2) [ wherein, k is 2 or 3 to 500, m is 1 or 2 to 4
Indicates an integer of 00. ] Since the phase separator having the structure of the general formula (2) has an oxypropylene group and an oxyethylene group in its structure, it is easy to control the balance between hydrophobicity and hydrophilicity, and the paste sol production conditions and application fields In consideration of the above, an optimum one can be selected from various phase separation agents. Of these, k is preferably 10 to 500, m
Is 5 to 300, and the ratio k / m of k to m is 1 to 1.
6, particularly preferably k / m of 1.5 to 5.

As the cation of M, monovalent cations such as alkali metal cations (sodium, potassium and lithium cations), ammonium cations and organic amine cations (lower alkylamine cations having 1 to 6 carbon atoms, 7 to 18 carbon atoms) Higher alkylamine cations, alkanolamine cations having 2 to 8 carbon atoms and tetraalkyl quaternary ammonium cations having 1 to 12 carbon atoms); divalent cations such as alkaline earth metal cations (such as calcium and magnesium cations)
And a mixture of a monovalent cation and a divalent cation may be used. Preferred among these are monovalent cations, more preferably alkali metal cations, particularly preferably sodium and potassium cations.

The phase separating agent represented by the general formula (1) is RO
It is obtained by addition polymerization of an alkylene oxide to an alcohol represented by H (preferably, addition polymerization of ethylene oxide to a polymer obtained by addition polymerization of propylene oxide) and sulfuric acid esterification, and is synthesized by a known method. You.

The amount of the phase separating agent varies depending on the type and amount of the plasticizer, the type of the phase separating agent, and the like, but is preferably 0.1 to 100 parts by weight of the total of the resin component and the plasticizer (B). It is in the range of 0.5 to 5 parts by weight, more preferably 0.3 to 3 parts by weight. If the addition amount is 0.05 parts by weight or more, the separation time does not become long, and if it is 5 parts by weight or less, it is economical. In addition, the said addition amount of a phase-separation agent, even when using a surfactant as a dispersant in the production process of the aqueous polyurethane resin dispersion (A) of the present invention,
This is the amount added separately from the surfactant as the dispersant. The separation operation by adding a phase separation agent is preferably performed at 10 to 35 ° C, more preferably 20 to 30 ° C.

The method of adding the phase separating agent includes (I) a method of preparing the aqueous dispersion (D) and then adding the phase separating agent, and
(II) A method in which the aqueous dispersion (D) is prepared and added at the same time [that is, a method in which the aqueous dispersion (A), the plasticizer (B), and the phase-separating agent are simultaneously mixed]. Good.

The aqueous dispersion in which the polyurethane resin particles have sufficiently transferred to the plasticizer phase separates the aqueous dispersion medium phase and the plasticizer phase when the stirring is stopped, and the separation speed is high when a phase separating agent is used. If the specific gravity of the aqueous dispersion medium phase is smaller than the specific gravity of the plasticizer phase, the upper layer separates into the aqueous dispersion medium phase and the lower layer separates into the plasticizer phase. As a method for removing the plasticizer phase, for example, a method of removing the aqueous dispersion medium phase of the upper layer by decantation or removing the plasticizer phase of the lower layer from below is simple. The plasticizer phase obtained by separation can be used as it is as a paste sol.However, in order to remove the separating agent and dispersant contained therein as necessary, water is added to the plasticizer phase, and stirring and separation are repeated. Can be washed. When washing, a phase separation agent may be added again. The amount of the phase separation agent added at this time is the same as described above.

Since the paste sol thus obtained contains 1 to 8% of water with respect to the total amount of the paste sol, dehydration can be performed if necessary.

The aqueous dispersion (D) or the paste sol of the present invention may be added to the aqueous dispersion (D) or the paste sol as long as the viscosity and stability are not adversely affected.
Antioxidants (eg, phenyl-β-naphthylamine, dibutyloxytoluene, etc.), mold release agents (eg, silicone resin, polyvinyl alcohol, etc.), flame retardants (eg, decabromodiphenyl oxide, triphenyl phosphate, etc.) as necessary , Filler (calcium carbonate,
Additives such as silica, kaolin, baryta, etc.) may be further added. The total weight of the additives is 0.5 to 1 with respect to the total weight of the polyurethane resin particles and the plasticizer.
0% by weight.

The paste sol of the present invention can be formed into a sheet, film, foam, blade, etc. by a method such as coating (knife coating, dip coating, roll coating, etc.), dip molding, slush molding, rotation molding and the like. It is molded and heat-treated, and if necessary, further molded to be used as a polyurethane resin molded article. After being applied by an injection machine or the like, it is heated and used as a sealing agent. The sealing agent is used, for example, as a sealing agent for automobile bodies, buildings and the like. The heat treatment is preferably performed at 100 to 200 ° C, more preferably at 120 to 160 ° C.

[0068]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples. All parts are parts by weight.

Example 1 A stainless steel reaction vessel equipped with a nitrogen introducing pipe, a reflux cooling pipe, a thermometer, and a stirrer was charged with MDI.
Was charged with 4000 parts of polypropylene glycol (weight average molecular weight 4000) and reacted at 80 ° C. for 4 hours, and 4500 parts of urethane prepolymer (NCO%
= 1.87%). A stainless steel beaker is charged with 1000 parts of water, 20 parts of sodium dodecylbenzenesulfonate as a dispersant, and 6.7 parts of ethylenediamine, and stirred at 10,000 rpm. Under the stirring, 500 parts of the above prepolymer was charged, and the mixture was stirred at 25 ° C. for 3 minutes to obtain a urethane resin aqueous dispersion (A-1) 1.
520 parts were obtained. At this time, the average particle size of the urethane resin particles was 5.43 μm. In another stainless steel beaker, 100 parts of (A-1) (resin solid content: 33.6%) was charged, and 15 parts of dioctyl phthalate was added as a plasticizer (B) while stirring at 25 ° C., followed by another 3000 parts.
The mixture was stirred at rpm for 2 minutes to obtain a polyurethane resin-plasticizer aqueous dispersion (D-1). (D-1) To 115 parts, 0.25 part of sodium dodecyl ether sulfate (a sulfate obtained by block addition polymerization of 30 mol of PO and then 10 mol of EO in dodecyl alcohol) was added as a phase separator at a temperature of 25 ° C. The mixture was stirred for 2 minutes under a stirring condition of a rotation number of 8000 rpm. When the stirring was stopped, the aqueous phase immediately separated into the upper layer and the paste sol separated into the lower layer. The time required for complete separation of both phases and the water content immediately after taking out the paste sol were measured (measured by the Karl Fischer method) and are shown in Table 1. Further, 45 parts of the paste sol was dehydrated under reduced pressure (pressure 70 mPa, temperature 25 ° C., 5 hours), and then 150 μm
m was placed in a mold and baked at 150 ° C. for 10 minutes to form a sheet. The obtained sheet was smooth without bubbles or the like due to excess moisture, had high breaking strength and high breaking elongation, and good physical properties were obtained. Table 1 shows the measured values of the breaking strength and the breaking elongation.

Example 2 In the same reaction vessel as in Example 1,
500 parts of MDI and 4000 parts of polyethylene glycol (weight average molecular weight 4000) were charged and reacted at 80 ° C. for 4 hours, and 4500 parts of urethane prepolymer (NC
O% = 1.85). 100 parts of water, 2 parts of sodium dodecylbenzenesulfonate and 0.67 parts of ethylenediamine as a dispersant are added to a stainless steel beaker, and the mixture is stirred under a stirring condition of 10,000 rpm. 50 parts of the above-mentioned prepolymer was put into this stirring, and the mixture was stirred for 3 minutes to obtain a urethane resin aqueous dispersion (A-2) 15
Two parts were obtained. At this time, the average particle size of the urethane resin particles was 4.98 μm. (A-2) To 100 parts (resin solid content: 33.8%), 15 parts of dibutyl phthalate and 0.25 part of the same sodium dodecyl ether sulfate salt as in Example 1 were added as a phase separator, and the number of rotations was 8,000 rpm. Under stirring conditions for 2 minutes. When the stirring was stopped, the aqueous phase immediately separated into the upper layer and the paste sol separated into the lower layer. The time required for complete separation of both phases and the water content immediately after the paste sol was removed were measured and are shown in Table 1. Further, a sheet was prepared in the same manner as in Example 1, and the performance evaluation results are shown in Table 1.

Example 3 An aqueous urethane resin dispersion (A-3) 1 was prepared in the same manner as in Example 2 except that 1.5 parts of sodium dodecylbenzenesulfonate was used as a dispersant.
52 parts were obtained. At this time, the average particle size of the urethane resin particles was 6.22 μm. Thereafter, a polyurethane resin-plasticizer aqueous dispersion (D-3) was obtained in the same manner as in Example 1 except that (A-3) was used. Further, (D-3)
Then, a paste sol was prepared in the same manner as in Example 1 except that 0.25 part of sodium dodecyl ether sulfate (sulfur oxide obtained by block addition polymerization of 60 moles of PO and 15 moles of EO to dodecyl alcohol) was added as a phase separator. Then, a sheet was produced. Table 1 shows the performance evaluation results.

Example 4 A paste sol was produced in the same manner as in Example 3 except that the amount of the phase separation agent was changed to 1 part, and a sheet was produced in the same manner as in Example 3. Table 1 shows the performance evaluation results.
It was shown to.

Comparative Example 1 200 parts of the aqueous polyurethane resin dispersion (A-1) obtained in Example 1 was centrifuged (1
(At 0000 rpm for 20 minutes) to separate the aqueous dispersion medium phase and the polyurethane resin particles. The polyurethane resin particles were taken out, dried at 30 ° C. under reduced pressure of 50 mmHg for 3 hours, and pulverized using a pulverizing mill to obtain 60 parts of a polyurethane resin powder. The average particle size of the polyurethane resin powder was 9.11 μm. 50 parts of this polyurethane resin powder and 22.3 parts of dioctyl phthalate were mixed to prepare a paste sol. A sheet was prepared from 50 parts of the paste sol in the same manner as in Example 1. Table 1 shows the performance evaluation results.

The breaking strength and breaking elongation are measured in accordance with JIS K630.
It measured according to 1.

[0075]

[Table 1]

[0076]

According to the paste sol production method of the present invention,
Paste sol can be produced directly from the aqueous dispersion without going through the drying and pulverization steps, so that resin particles do not agglomerate due to drying and the particle size distribution is uniform, so that flow properties are constant and handling such as processing is easy. Becomes Furthermore, the appearance and physical properties of the molded product obtained by molding this paste sol are excellent since there is no adverse effect such as foaming due to excess moisture. In addition, there is no loss that can be used conventionally due to aggregation in the drying step, and the yield is greatly increased, which is very advantageous from the viewpoint of cost. In addition, no crushing equipment is required, which is economically advantageous. Because of the above effects, the paste sol produced by the method of the present invention can be used to form a sheet, film, foam, blade-shaped polyurethane resin molded product, and also a car body, a sealing agent for building, etc. Useful for

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Claims (11)

[Claims] A polyurethane resin comprising a plasticizer phase containing polyurethane resin particles dispersed in an aqueous dispersion medium.
Aqueous plasticizer dispersion (D). 2. The polyurethane resin particles comprise 20 to 90% by weight based on the total weight of the polyurethane resin particles and the plasticizer.
The aqueous dispersion according to claim 1, which is 3. The method according to claim 1, wherein the polyurethane resin particles have a number average particle size of 0.1 to 100 μm, and the plasticizer phase containing the particles has a number average particle size of 0.2 to 500 μm. Aqueous dispersion. 4. A polyurethane resin aqueous dispersion (A) and a plasticizer (B) are mixed, (B) is dispersed in an aqueous dispersion medium of (A), and the polyurethane resin particles in (A) are mixed with a plasticizer. The aqueous dispersion according to any one of claims 1 to 3, wherein the aqueous dispersion is produced by transferring to a phase. 5. A method for producing a polyurethane resin paste sol, comprising separating and removing an aqueous dispersion medium phase from the aqueous dispersion (D) according to claim 1. 6. The method for producing a paste sol according to claim 5, wherein a surfactant is further added to the aqueous dispersion (D) to separate and remove the aqueous dispersion medium phase. 7. The method according to claim 6, wherein the surfactant is an anionic surfactant. 8. The method for producing a paste sol according to claim 7, wherein the anionic surfactant is a sulfate salt represented by the following general formula (1). RO- (QO) _n -SO ₃ M (1) [wherein, R is a hydrocarbon group having 6 to 30 carbon atoms, Q is an alkylene group having 2 to 4 carbon atoms, M is a cation, and n is 5 to 600.
Indicates an integer. ] 9. A polyurethane resin paste sol obtained by the production method according to claim 5. 10. A molded polyurethane resin article obtained by coating or molding the paste sol according to claim 9 and then heating. 11. The polyurethane resin molded product according to claim 10, which is in the form of a sheet, a film, a foam, or a blade.