JP5415023B2 - Polyurethane resin emulsion - Google Patents

Description

  The present invention relates to a high molecular weight polyurethane resin emulsion excellent in water resistance.

Polyurethane resin emulsions are used in the paint, adhesive, binder and coating agent fields as high-performance emulsions due to their excellent durability, chemical resistance, and abrasion resistance, etc. From the viewpoint of resource saving and safety, it is expected to become increasingly important. A polyurethane resin emulsion generally contains an anionic group such as a carboxyl group and a sulfo group in the main chain, and a tertiary amine such as triethylamine as a neutralizing agent. As an exception, polyurethane resin emulsions that have primary and / or secondary monoamines as neutralizing agents to prevent deactivation of acid catalysts used in curing reactions when used in thermosetting paints (Patent Documents) -1) and a polyurethane resin emulsion (Patent Document 2) and the like that are quick to dry and have excellent water resistance by containing ammonia as a neutralizing agent have been reported.
JP-A-6-93068 Japanese Patent Application Laid-Open No. 9-10032

However, the polyurethane resin emulsion described in Patent Document-1 is a mixture of a polyurethane resin emulsion having a tertiary amine salt and a primary or secondary monoamine and then removing the liberated tertiary amine. Only a polyurethane resin emulsion having a primary or secondary amine having a boiling point was obtained, and there was a problem that the water resistance of the dried coating film was poor. On the other hand, the polyurethane resin emulsion described in Patent Document-2 has a problem that the side reaction between isocyanate and ammonia or water is not sufficiently suppressed, a high molecular weight polyurethane resin emulsion cannot be obtained, and the strength of the dry coating film is low. was there.
The present invention has been made to solve these problems, and an object of the present invention is to provide a polyurethane having excellent dry film water resistance and high molecular weight resulting in excellent dry film strength. It is to provide a resin emulsion.

The inventor of the present invention has reached the present invention as a result of intensive studies to solve the above-mentioned problems. That is, the present invention is a polyurethane resin emulsion comprising a polyurethane resin (U) and water and satisfying the following (1) to (3).
(1) The weight average molecular weight (Mw) of the polyurethane resin (U) is 20,000 to 2,000,000, and the weight average molecular weight (Mw) and number average molecular weight (Mn) of the polyurethane resin (U). The ratio (Mw / Mn) is 1.5 to 3.5.
(2) The polyurethane resin (U) is selected from the group consisting of ammonia and an amine having 1 to 10 carbon atoms , and has at least one of a primary amine and a secondary amine having a boiling point of 90 ° C. or lower as an essential component. has neutralized carboxyl groups and / or sulfo group with a neutralizing agent which comprises as ammonia in the neutralizing agent, the total amount of the primary amine and the secondary amine, the total neutralization Based on the number of moles of the agent, it is 30 to 100 mol%.
(3) No emulsifier is used when the polyurethane resin (U) is dispersed in water.

  The polyurethane resin emulsion of the present invention is excellent in the water resistance of the dried coating film, and also has the effect of being excellent in the strength of the dried coating film by being made of a high molecular weight polyurethane resin.

  The polyurethane resin (U) in the present invention is composed of a polyisocyanate component (a1), a polyol component (a2), a hydrophilic group-containing active hydrogen-containing component (a3) and, if necessary, other components (a4).

  As the polyisocyanate component (a1) constituting (U), those conventionally used for polyurethane production can be used. As (a1), an aromatic polyisocyanate (a11) having 2 or more isocyanate groups and having 6 to 20 carbon atoms (hereinafter abbreviated as C) (excluding carbon in the isocyanate groups, the same shall apply hereinafter), C2-18 aliphatic polyisocyanate (a12), C4-15 alicyclic polyisocyanate (a13), C8-15 araliphatic polyisocyanate (a14), modified products of these polyisocyanates (a15), etc. Can be mentioned. (A1) may be used alone or in combination of two or more.

  Examples of the C6-20 aromatic polyisocyanate (a11) include 1,3- or 1,4-phenylene diisocyanate, 2,4- or 2,6-tolylene diisocyanate (TDI), crude TDI, 4,4 ′. -Or 2,4'-diphenylmethane diisocyanate (MDI), crude MDI [crude diaminophenylmethane {condensation product of formaldehyde with an aromatic amine (aniline etc.) or a mixture thereof; diaminodiphenylmethane and a small amount (for example, 5 to 20% by weight) ) And a triaryl polyisocyanate (PAPI), etc.], 4,4′-diisocyanatobiphenyl, 3,3′-dimethyl-4,4′-diisocyanate Biphenyl, 3,3'-dimethyl-4,4'-diisocyanatodiphenyl Tan, 1,5-naphthylene diisocyanate, 4,4 ', 4 "- include triphenylmethane triisocyanate and m- or p- isocyanatophenyl sulfonyl isocyanate.

  Examples of the C2-18 aliphatic polyisocyanate (a12) include ethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate (HDI), dodecamethylene diisocyanate, 1,6,11-undecane triisocyanate, and 2,2,4-trimethyl. Hexamethylene diisocyanate, lysine diisocyanate, 2,6-diisocyanatomethylcaproate, bis (2-isocyanatoethyl) fumarate, bis (2-isocyanatoethyl) carbonate and 2-isocyanatoethyl-2,6-diisocyanate And natohexanoate.

  Examples of the C4-15 alicyclic polyisocyanate (a13) include isophorone diisocyanate (IPDI), 4,4-dicyclohexylmethane diisocyanate (hydrogenated MDI), cyclohexylene diisocyanate, methylcyclohexylene diisocyanate (hydrogenated TDI), and bis. (2-isocyanatoethyl) -4-cyclohexene-1,2-dicarboxylate and 2,5- or 2,6-norbornane diisocyanate.

  Examples of the C8-15 araliphatic polyisocyanate (a14) include m- or p-xylylene diisocyanate (XDI) and α, α, α ', α'-tetramethylxylylene diisocyanate (TMXDI).

  As the modified polyisocyanate (a15), modified products of the above polyisocyanates (a11) to (a14) (urethane group, carbodiimide group, allophanate group, urea group, burette group, uretdione group, uretoimine group, isocyanurate group) And modified products containing oxazolidone groups; free isocyanate group content is usually 8 to 33%, preferably 10 to 30%, particularly 12 to 29%, such as modified MDI (urethane modified MDI, carbodiimide modified MDI and trihydrocarbyl phosphate) Modified MDI, etc.), urethane-modified TDI, biuret-modified HDI, isocyanurate-modified HDI and isocyanurate-modified IPDI, and urethane-modified polyisocyanates [excess polyisocyanates (such as TDI and MDI) and polyols] Polyols used in the production of free isocyanate-containing prepolymer] obtained by reacting, include low molecular weight polyols described later (a22).

  Among these polyisocyanate components (a1), C2-18 aliphatic polyisocyanate (a12) and C4-15 alicyclic polyisocyanate (a13) are preferred, and (a13) is particularly preferred. Preference is given to IPDI and hydrogenated MDI.

  Examples of the polyol component (a2) include a polymer polyol (a21) having a number average molecular weight (hereinafter abbreviated as Mn) of 400 to 5,000 and a low molecular polyol (a22) having a Mn of less than 400.

  Mn can be measured by gel permeation chromatography (hereinafter GPC) using tetrahydrofuran as a solvent and polystyrene as a standard.

Examples of the polymer polyol (a21) include polyether polyol (a211), polyester polyol (a212), and polycarbonate polyol (a213).
Mn of (a21) is usually 400 to 5,000, preferably 500 to 5,000, and more preferably 1,000 to 3,000, from the viewpoint of the physical properties of the dried coating film.

  Examples of the polyether polyol (a211) include aliphatic polyether polyols and aromatic ring-containing polyether polyols.

  Aliphatic polyether polyols include aliphatic low molecular weight active hydrogen atom-containing compounds (divalent to octavalent or higher aliphatic polyhydric alcohols having a hydroxyl equivalent weight of 30 to 150 and primary or as active hydrogen atom-containing groups. An alkylene oxide (hereinafter abbreviated as AO) adduct of a compound containing a secondary amino group can be used.

  Examples of the aliphatic polyhydric alcohol to which AO is added include linear or branched aliphatic dihydric alcohols [(di) ethylene glycol, (di) propylene glycol, 1,2-, 1,3-, 2,3- Or 1,4-butanediol, neopentyl glycol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, 2-methyl-1,8-octanediol, 1,9-nonanediol and 1,12 -Dodecanediol etc.], alicyclic dihydric alcohol [low molecular diol having a cyclic group, such as described in JP-B No. 45-1474], aliphatic trihydric alcohol [glycerin, trimethylolpropane, trialkanolamine, etc. And aliphatic tetravalent or higher alcohol [pentaerythritol, diglycerin, triglycerin, dipentaerythritol Sorbitol, sorbitan and sorbide, etc.] and the like.

  Examples of the compound containing a primary or secondary amino group to which AO is added include alkyl (C1-12) amine and (poly) alkylene polyamine (C2-6 of alkylene group, number of alkylene groups 1 to 4 and amine). 2-5) etc. are mentioned.

  As the aromatic ring-containing polyether polyol, an AO adduct of an aromatic low molecular weight active hydrogen atom-containing compound (divalent to octavalent or higher phenol having a hydroxyl group equivalent of 30 to 150 or higher) can be used. .

  Examples of phenols to which AO is added include hydroquinone, catechol, resorcin, bisphenol A, bisphenol S and bisphenol F, and examples of aromatic amines include aniline and phenylenediamine.

  As AO used for manufacture of an AO adduct, C2-12 or more AO, for example, ethylene oxide (hereinafter abbreviated as EO), propylene oxide (hereinafter abbreviated as PO), 1,2-, 2,3- Alternatively, 1,3-butylene oxide, tetrahydrofuran (THF), α-olefin oxide, styrene oxide, epihalohydrin (such as epichlorohydrin) and a mixture of two or more of these can be given.

  Examples of the aliphatic polyether polyol include polyoxyethylene polyol [polyethylene glycol (hereinafter abbreviated as PEG) and the like], polyoxypropylene polyol [polypropylene glycol (hereinafter abbreviated as PPG) and the like], and polytetramethylene glycol (hereinafter referred to as PTMG). Abbreviations) and polyoxyethyleneoxypropylene polyols.

  Examples of the aromatic ring-containing polyether polyol include polyols having a bisphenol skeleton [for example, EO addition product of bisphenol A (addition mole number 2 to 20) and PO addition product of bisphenol A (addition mole number 2 to 20)] and resorcinol. Examples include EO or PO adducts.

  Examples of the polyester polyol (a212) include condensed polyester polyols and polylactone polyols.

The condensation type polyester polyol includes a polyester of a low molecular weight polyhydric alcohol and a polyvalent carboxylic acid or an ester-forming derivative thereof.
Low molecular weight polyhydric alcohols include dihydric to octavalent or higher aliphatic polyhydric alcohols having a hydroxyl equivalent weight of 30 to 150, and divalent to octavalent or higher polyphenols AO having a hydroxyl equivalent weight of 30 to 150. Low molar adducts (added moles 1-10) can be used.

Specific examples of the low molecular weight polyhydric alcohol that can be used in the condensed polyester polyol include, for example, ethylene glycol, propylene glycol, 1,4-butanediol, neopentyl glycol, 1,6-hexane glycol, bisphenol A EO or PO Low molar adducts and mixtures thereof are mentioned.

  Examples of polycarboxylic acids or ester-forming derivatives thereof include aliphatic dicarboxylic acids (succinic acid, adipic acid, azelaic acid, sebacic acid, fumaric acid, maleic acid, etc.), alicyclic dicarboxylic acids (dimer acid, etc.), aromatic Dicarboxylic acids (terephthalic acid, isophthalic acid, phthalic acid, etc.), trivalent or higher polycarboxylic acids (trimellitic acid, pyromellitic acid, etc.), and anhydrides thereof (succinic anhydride, maleic anhydride, phthalic anhydride) Acid and trimellitic anhydride), acid halides thereof (such as adipic acid dichloride), low molecular weight alkyl esters thereof (such as dimethyl succinate and dimethyl phthalate), and mixtures thereof.

  Examples of the condensed polyester polyol include polyethylene adipate diol, polybutylene adipate diol, polyhexamethylene adipate diol, polyhexamethylene isophthalate diol, polyneopentyl adipate diol, polyethylene propylene adipate diol, polyethylene butylene adipate diol, polybutylene hexamethylene Examples include adipate diol, poly (3-methylpentylene adipate) diol, polyethylene azelate diol, polyethylene sebacate diol, polybutylene azelate diol, polybutylene sebacate diol and polyneopentyl terephthalate diol.

  The polylactone polyol is a polyaddition product of a lactone to the low molecular weight polyhydric alcohol, and as the lactone, a C4-12 lactone (for example, ε-caprolactone, γ-butyrolactone, γ-valerolactone or the like alone or 2). A mixture of seeds or more). Examples of the polylactone polyol include polycaprolactone diol, polyvalerolactone diol, and polycaprolactone triol.

  As the polycarbonate polyol (a213), from the viewpoint of the physical properties of the C4-12, dry coating film, it is preferably C6-10, more preferably one or more alkylene diols having a C6-9 alkylene group, and low Manufactured by condensing molecular carbonate compounds (for example, C1-6 dialkyl carbonates of alkyl groups, alkylene carbonates having C2-6 alkylene groups and diaryl carbonates having C6-9 aryl groups) while carrying out dealcoholization reaction. And polycarbonate polyols to be used.

  Examples of alkylene diols having a C4-12 alkylene group include linear alkylene diols (for example, tetramethylene diol, pentamethylene diol, hexamethylene diol, heptamethylene diol, octamethylene diol and nonamethylene diol) and branched alkylene diols (for example 2 -Methylpentanediol, 3-methylpentanediol, 2-methylhexanediol, 3-methylhexanediol, 2-methylheptanediol, 3-methylheptanediol, 4-methylheptanediol, 2-methyloctanediol, 3-methyl Octanediol and 4-methyloctanediol), and particularly preferred are tetramethylenediol, pentamethylenediol, hexamethylenediol and Methylene diol, intended for the branch which is 3-methyl-1,5-pentanediol and 2-methyl-1,8-octanediol.

Examples of the commercially available polycarbonate diol (a213) include “Nipporan 980R” (manufactured by Nippon Polyurethane Co., Ltd.), “Placcel CD220” (manufactured by Daicel Corporation), “PCDL T4671” (manufactured by Asahi Kasei Corporation), “ PCDL T5652 "[Asahi Kasei Co., Ltd.] and" Kuraray polyol C-2090 "[Kuraray Co., Ltd.] are mentioned.

  Among the high-molecular polyols (a21), preferred are aliphatic polyether diols and aliphatic polyester diols, and particularly preferred are PTMG, polybutylene adipate diol, polyhexamethylene adipate diol, and a mixture of two or more thereof. .

  As the low molecular polyol (a22) having a Mn of less than 400, C2-15 polyhydric alcohols [dihydric alcohols (eg, ethylene glycol, propylene glycol, 1,4-butanediol, 1,5-pentanediol, neopentyl glycol, 1,6-hexanediol, 1,8-octanediol, 1,4-cyclohexanedimethanol and diethylene glycol); trihydric alcohols (eg glycerin and trimethylolpropane); ethylene oxide and / or propylene oxide of these polyhydric alcohols Low molar adducts (Mn less than 400), etc.].

  Examples of the hydrophilic group-containing active hydrogen-containing component (a3) include a diol having a carboxyl group or a sulfo group in the molecule and a diol obtained by neutralizing these acid groups with a neutralizing agent.

  Examples of the diol having a carboxyl group in the molecule include C6-24 dialkyrol alkanoic acids [for example, 2,2-dimethylolpropionic acid, 2,2-dimethylolbutanoic acid, 2,2-dimethylolheptanoic acid and 2 , 2-dimethyloloctanoic acid].

  Examples of the diol having a sulfo group in the molecule include 3- (2,3-dihydroxypropoxy) -1-propanesulfonic acid, sulfoisophthalic acid di (ethylene glycol) ester, and N, N-bis (2-hydroxylethyl) sulfamine. An acid etc. are mentioned.

Among (a3), preferred are 2,2-dimethylolpropionic acid and 2,2-dimethylolbutanoic acid from the viewpoint of the resin physical properties of the polyurethane resin (U) and the temporal stability and dispersion stability of the polyurethane resin emulsion. It is.

  As neutralizing agents used for neutralizing carboxyl groups, sulfo groups or phosphono groups, ammonia and C1-10 amine compounds (for example, primary amines such as monomethylamine, monoethylamine, monobutylamine and monoethanolamine) Secondary amines such as dimethylamine, diethylamine, dibutylamine and diethanolamine, and tertiary amines such as trimethylamine, triethylamine, dimethylethylamine and triethanolamine).

  As the neutralizing agent, a compound having a boiling point of 90 ° C. or less is preferable from the viewpoint of the drying property of the polyurethane resin emulsion to be produced and the water resistance after drying. From such a viewpoint, ammonia, monomethylamine, monoethylamine, dimethylamine, diethylamine, trimethylamine, triethylamine and dimethylethylamine are preferable as the neutralizing agent, and ammonia, monoethylamine, dimethylamine and diethylamine are particularly preferable. Is ammonia.

  Examples of the other component (a4) used as necessary include a chain extender (a41) and a terminator (a42).

  As (a41), C2-10 diamines (for example, ethylenediamine, propylenediamine, hexamethylenediamine, isophoronediamine, toluenediamine and piperazine), poly (2-10) alkylene poly (3-11) amines (for example, diethylenetriamine) And triethylenetetramine), hydrazine and its derivatives (dibasic acid dihydrazide such as adipic acid dihydrazide) and C2-10 amino alcohols (such as ethanolamine, diethanolamine, 2-amino-2-methylpropanol and triethanolamine) Can be mentioned.

  As (a42), C1-8 monoalcohols (methanol, ethanol, isopropanol, cellosolves, carbitols, etc.), C1-10 amines (monomethylamine, monoethylamine, monobutylamine, dibutylamine and monooctyl) Mono- or dialkylamines such as amine; mono- or dialkanolamines such as monoethanolamine, diethanolamine, and diisopropanolamine).

The total content of carboxyl groups [—COOH] and sulfo groups [—SO ₃ H] in (U) (hereinafter referred to as acid group content) is the weight of (U) from the viewpoint of the water resistance of the coating film. Is preferably 5.0% by weight or less, more preferably 0.5 to 3.0% by weight. In addition, the acid group content in the present invention is defined as a content converted from an acid anion group to an acid group even if it is a neutralized acid anion group (—COO ⁻ and —SO ₃ ⁻ ).

In order for the acid group content in (U) to be within the above range, it is preferable to set the amount of (a3) charged during the production of (U) according to the following formula.
Target acid group content (%) = [weight corresponding to COOH based on the charged amount of (a3) + weight corresponding to SO ₃ H based on the charged amount of (a3)] ÷ all of resin components after emulsion production Weight x 100

The neutralization rate when neutralizing (a3) with a neutralizing agent [ratio of the number of moles of neutralized (a3) to the total number of moles of (a3) constituting the urethane resin (U) (percentage)] is From the viewpoint of the water resistance of the coating film and the stability of the emulsion, it is preferably 50 to 100%, more preferably 70 to 100%, and particularly preferably 90 to 100%. By setting it as such a neutralization rate, when a urethane resin (U) is disperse | distributed to water, an emulsion with favorable dispersion stability can be obtained, without using an emulsifier.
The neutralization with the neutralizing agent is preferably performed after the urethanization reaction or before dispersion in water or during dispersion from the viewpoint of increasing the molecular weight of (U).

  From the viewpoint of drying properties and water resistance of the dried coating film, 30 to 100 mol% of the neutralizing agent (a3) is preferably ammonia, a primary amine and / or a secondary amine, more preferably 70. It is -100 mol%, Most preferably, it is 80-100 mol%.

  In the present invention, the polyurethane resin (U) is prepared in the absence of an organic solvent, with (a1) to (a3) and, if necessary, (a4), a reaction temperature of 50 to 250 ° C, preferably 100 ° C to 250 ° C, more preferably. 150 ° C to 250 ° C, most preferably 180 ° C to 240 ° C, reaction time 5 minutes to 70 minutes, preferably 6 minutes to 60 minutes, more preferably 7 minutes to 50 minutes, most preferably 8 minutes to 40 minutes It is obtained by the chemical reaction. If the reaction temperature and reaction time are within this range, the resin physical properties after drying are good.

  In the urethanization reaction, in order to promote the reaction, a catalyst used in a normal urethane reaction may be used if necessary. Examples of the catalyst include triethylamine, N-ethylmorpholine, triethylenediamine, and cycloamidines described in US Pat. No. 4,524,104 [1,8-diaza-bicyclo [5,4,0] -7-undecene (Sanpro Corporation). Amine catalysts such as “DBU” and the like; tin-based catalysts such as dibutyltin dilaurate, dioctyltin dilaurate and tin octylate; titanium-based catalysts such as tetrabutyltitanate and the like.

  The reaction vessel for carrying out the urethanization reaction can be used without any problem as long as it can be heated and stirred, but from the viewpoint of stirring strength, hermeticity and heating ability, it is preferable to use a single or twin screw extruder. preferable. Examples of the uniaxial or biaxial extruder include a continuous kneader [manufactured by Kurimoto Seiko Co., Ltd.] and a uniaxial kneader.

  The polyurethane resin emulsion of the present invention contains the polyurethane resin (U) and water.

  The weight average molecular weight (Mw) of the polyurethane resin (U) in the polyurethane resin emulsion of the present invention [measured by GPC with N, N-dimethylformamide or tetrahydrofuran as a solvent and based on standard polystyrene] In the case of a crosslinking type (thermoplastic: a type not using a crosslinking agent), it is usually 20,000 to 2,000,000, preferably 2,1000 to 500,000, particularly preferably 22,000 to 100,000. . (U) of a crosslinking type (a type using a crosslinking agent) may have a Mw higher than the above range or a high Mw that cannot be measured by GPC. Moreover, Mw / Mn of the polyurethane resin (U) in the present invention is measured by GPC, and is usually 1.5 to 3.5, preferably 1.5 to 3.3, particularly preferably. 1.5-3. If Mw and Mw / Mn are in this range, the physical properties and film-forming properties of the coating film are good.

  The volume average particle diameter (hereinafter abbreviated as Dv) of the polyurethane resin (U) in the polyurethane resin emulsion of the present invention is preferably from 0.01 to 5 μm, more preferably from 0 to 5 μm from the viewpoint of improving dispersion stability. It is 01 to 4 μm, particularly preferably 0.02 to 2 μm, particularly preferably 0.01 to 1 μm, and most preferably 0.03 to 0.8 μm. The volume average particle diameter / number average particle diameter (hereinafter abbreviated as Dv / Dn) of the polyurethane resin particles is preferably 1.2 to 5, more preferably 1.2 to 4, particularly preferably 1. 2-3. If Dv and Dv / Dn are within this range, the dispersion stability and the film forming property upon drying are further improved.

  For Dv and Dv / Dn, a laser diffraction particle size distribution measuring device [for example, LA-750: manufactured by Horiba, Ltd.] or a light scattering particle size distribution measuring device [for example, ELS-8000: manufactured by Otsuka Electronics Co., Ltd.] Can be measured.

The viscosity at 25 ° C. of the polyurethane resin emulsion of the present invention is preferably 10 to 100,000 mpa · s, more preferably 10 to 5,000 mpa · s, from the viewpoint of emulsion stability. The viscosity can be measured using a BL type viscometer.
The pH of the polyurethane resin emulsion of the present invention is preferably 2 to 12 and more preferably 4 to 10 from the viewpoints of temporal stability and dispersion stability. The pH can be measured at 25 ° C. with pH Meter M-12 [manufactured by Horiba, Ltd.].

The solid content concentration (content of components other than water) of the polyurethane resin emulsion of the present invention is preferably 20 to 65% by weight, more preferably 25 to 55% by weight from the viewpoint of emulsion stability.
The solid content is about 1 g of the emulsion thinly spread on a Petri dish, weighed accurately, then weighed the weight after heating at 130 ° C for 45 minutes using a circulating constant temperature dryer, and weighed the weight before heating. It can be obtained by calculating the ratio (percentage) of the remaining weight after heating.

  The polyurethane resin emulsion of the present invention can be produced by neutralizing the above polyurethane resin (U) with a neutralizing agent or by dispersing in water while neutralizing. Specifically, for example, a method of dispersing in water at a temperature lower than the melting temperature of the polyurethane resin (U) using a rotary dispersion mixing apparatus as the dispersion mixing apparatus can be mentioned.

  When the above method is used, the polyurethane resin (U) has a melting temperature of 70 to 280 ° C., and is usually solid at room temperature, preferably 0.2 to 50 mm at 25 ° C., more preferably 0.00. Particulate matter having a volume average particle size of 5 to 30 mm, particularly preferably 1 to 10 mm is preferable from the viewpoint of easy supply to a rotary dispersion mixing apparatus.

  As means for adjusting the polyurethane resin (U) into particles, means such as cutting, pelletizing, granulating or pulverizing can be used. This adjustment to the particulate form can be carried out in water or in the absence of water. For example, the method of making the polyurethane resin (U) rolled into the sheet form into a particulate form with a square pellet machine [manufactured by Horai Co., Ltd.] can be mentioned.

  Polyurethane resin (U) adjusted into particles is introduced into a rotary dispersion mixing device together with water. The main dispersion principle of this device is that the particles are crushed by applying shearing force to the particles from the outside by rotation of the drive unit, etc. This is the principle of dispersion. The apparatus can be operated at normal pressure or under pressure.

  Examples of the rotary dispersion mixing apparatus include TK homomixer [manufactured by Primics Co., Ltd.], Claremix [manufactured by Mtechnics Co., Ltd.], Philmix [manufactured by Primix Co., Ltd.], Ultra Turrax [manufactured by IKA Corporation] ], Ebara Milder [manufactured by Ebara Manufacturing Co., Ltd.], Cavitron (manufactured by Eurotech) and biomixer [manufactured by Nippon Seiki Co., Ltd.], and these two or more types of apparatuses may be used in combination. .

  The temperature of the dispersion when the polyurethane resin (U) is dispersed and mixed using a rotary dispersion mixing device is selected from the viewpoint of preventing decomposition and deterioration of the polyurethane resin (U) as a dispersion. ), Lower than the melting temperature, preferably at least 5 ° C. below the melting temperature and above room temperature, more preferably at a temperature lower than the melting temperature by 10 to 120 ° C. and above room temperature, dispersion efficiency and suppression of degradation / degradation From the viewpoint of

  The residence time of the polyurethane resin (U) and water in the rotary dispersion mixing apparatus is usually 0.1 to 60 minutes, preferably 10 to 30 minutes, from the viewpoint of suppressing decomposition and deterioration.

  In the method for producing the polyurethane resin emulsion, it is not necessary to neutralize the terminal isocyanate prepolymer as in the conventional prepolymer mixing method. Therefore, even if ammonia, a primary amine or a secondary amine is used as a neutralizing agent. An emulsion in which a high molecular weight polyurethane resin (U) is dispersed can be obtained.

  Since the polyurethane resin emulsion obtained by the production method of the present invention does not substantially use an organic solvent in the production process, there is substantially no remaining organic solvent. Therefore, it is excellent in low environmental load, safety, and low odor.

  The polyurethane resin emulsion of the present invention comprises a coating composition, an adhesive composition, a binder composition for fiber processing (a binder composition for pigment printing, a binder composition for nonwoven fabric, a sizing agent composition for reinforcing fibers, and a binder for antibacterial agents). Composition, etc.), coating compositions (waterproof coating composition, water repellent coating composition, antifouling coating composition, etc.) and raw materials for artificial leather and synthetic leather.

  For coating compositions, additives such as coating film forming auxiliary resins, crosslinking agents, pigments, pigment dispersants, viscosity modifiers, antifoaming agents, leveling agents, preservatives, anti-deterioration agents, stabilizers and freezing agents are optionally added. One type or two or more types of inhibitors can be added.

  Binder composition for antibacterial agent, coating composition, additive when used as raw material composition for artificial leather / synthetic leather, concentration of treatment liquid, means for applying to fiber, amount attached to fiber, treatment condition, etc. It can be adopted as appropriate.

<Example>
EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited to these. Hereinafter, “part” means “part by weight” and “%” means “% by weight”. In addition, Example 1 and Example 3 below are reference examples.

Example 1
To a KRC kneader [manufactured by Kurimoto Seiko Co., Ltd.] of a twin-screw kneader, 123.2 parts of 1,4-butane, a polycarbonate diol having an Mn of 1,000 “Asahi Kasei PCDL-T4671” [manufactured by Asahi Kasei Chemicals Corporation] 19.4 parts of diol, 25.2 parts of 2,2-dimethylolpropionic acid and 132.6 parts of 4,4-dicyclohexylmethane diisocyanate were introduced under a nitrogen atmosphere. Thereafter, the mixture was heated to 220 ° C. and kneaded for 10 minutes to carry out a urethanization reaction. The reaction product was taken out, rolled with a pressure press machine heated to 180 ° C., and then cut with a square pellet machine (manufactured by Horai Co., Ltd.). Subsequently, 16.8 parts of 25% aqueous ammonia (neutralizing agent) and 300.4 parts of pelletized urethane resin were added to 686.8 parts of ion exchange water at 90 ° C., and Claremix [M The product was dispersed at 20,000 rpm for 3 minutes using Technique Co., Ltd. to obtain 1,000 parts of polyurethane resin emulsion (Q-1). Table 1 shows the composition of the urethane resin and the physical properties of the urethane resin emulsion. Similarly for the following Examples and Comparative Examples, the composition of the urethane resin and the physical property values of the urethane resin emulsion are shown in Table 1.

  In the same manner as in Example 1, the polyurethane resin emulsions of Examples 2 to 5 and Comparative Example 1 were produced using the raw materials described in Table 1 in the number of parts described in Table 1. “PTMG1000” (manufactured by Mitsubishi Chemical Co., Ltd.) is polytetramethylene glycol with Mn 1,000, and “Nipporan 4073” (manufactured by Nippon Polyurethane Co., Ltd.) is polyhexamethylene adipate diol with Mn 2,000. Further, when ammonia was used, a 25% aqueous ammonia having a part number shown in Table 1 was used as the ammonia.

Comparative Example 2
In a simple pressure reaction apparatus equipped with a stirrer and a heater, 110.9 parts of polycarbonate diol “Asahi Kasei PCDL-T4671” (manufactured by Asahi Kasei Chemicals Co., Ltd.) having an Mn of 1,000, 18 parts of 1,4 butanediol, 3621.6 parts of 2,2-dimethylolpropionic acid, 149.9 parts of 4,4-dicyclohexylmethane diisocyanate and 75 parts of acetone (1) were charged while introducing nitrogen. Thereafter, the mixture was heated to 95 ° C. and subjected to urethanization reaction for 5 hours to produce a prepolymer. After cooling the reaction mixture to 40 ° C., 115 parts of acetone (2) and 5.5 parts of 25% ammonia water are added and mixed, and 463 parts of water is further added and emulsified with a rotor-stator type mechanical emulsifier. This gave an emulsion. Under stirring, 53.1 parts of a 10% diethylenetriamine aqueous solution and 5.5 parts of 25% aqueous ammonia were added to the obtained emulsion, and the mixture was stirred at 50 ° C. for 5 hours to carry out a chain extension reaction. Thereafter, acetone was removed at 65 ° C. under reduced pressure to obtain a polyurethane resin emulsion.

Comparative Example 3
In the same manner as in Comparative Example 2, a polyurethane resin emulsion of Comparative Example 3 was produced using the raw materials described in Table 1 by the number of parts described in Table 1.

The physical property measuring methods and evaluation methods shown in Table 1 are shown below.
<Mw and Mn>
The emulsion is added to DMF so that the solid content of polyurethane resin is 0.0125% by weight, stirred at room temperature for 1 hour, and then filtered under pressure with a filter having a pore size of 0.3 μm, and contained in the obtained filtrate. The urethane resin was measured by GPC using DMF as a solvent and polystyrene as a molecular weight standard.
<Dv and Dn>
The polyurethane resin emulsion was diluted with ion-exchanged water so that the solid content of the polyurethane resin was 0.01% by weight, and then measured using a light scattering particle size distribution analyzer [ELS-8000 (manufactured by Otsuka Electronics Co., Ltd.)]. did.
<Physical properties of dry film (100% stress, tensile strength and elongation at break)>
5. According to JIS K7311 Based on a tensile test. The measurement sample was uniformly mixed with 10 parts of a polyurethane resin emulsion and 1 part of N-methylpyrrolidone, and poured into a polypropylene mold of 10 cm × 20 cm × 0.1 cm in such an amount that the film thickness after drying with water was 200 μm. Based on a film obtained by heating and drying at 105 ° C. for 3 hours at room temperature for 12 hours at room temperature and based on a 5.1 test piece described in JIS K7311.
<Water resistance of dry paint film>
The film obtained in the same manner as the measurement of the physical properties of the dried film was immersed in ion-exchanged water for 24 hours, and then the state of the film taken out was visually evaluated. In the case of no change at all, ◯, in the case where whitening was observed, △, and in the case where whitening did not remain the original shape, ×.

  The polyurethane resin emulsion of the present invention can be suitably used as a coating composition, an adhesive composition and a binder for fiber processing.

Claims (3)

A polyurethane resin emulsion comprising a polyurethane resin (U) and water and satisfying the following (1) to (3).
(1) The weight average molecular weight (Mw) of the polyurethane resin (U) is 20,000 to 2,000,000, and the weight average molecular weight (Mw) and number average molecular weight (Mn) of the polyurethane resin (U). The ratio (Mw / Mn) is 1.5 to 3.5.
(2) The polyurethane resin (U) is selected from the group consisting of ammonia and an amine having 1 to 10 carbon atoms , and has at least one of a primary amine and a secondary amine having a boiling point of 90 ° C. or lower as an essential component. has neutralized carboxyl groups and / or sulfo group with a neutralizing agent which comprises as ammonia in the neutralizing agent, the total amount of the primary amine and the secondary amine, the total neutralization Based on the number of moles of the agent, it is 30 to 100 mol%.
(3) No emulsifier is used when the polyurethane resin (U) is dispersed in water. The volume average particle diameter (Dv) of the polyurethane resin (U) is 0.01 to 5 µm, and the volume average particle diameter / number average particle diameter (Dv / Dn) is 1.2 to 5. The polyurethane resin emulsion listed. The polyurethane resin emulsion according to claim 1 or 2, which does not contain an organic solvent.