JP3896578B2 - Water-based polyurethane emulsion paint - Google Patents

Description

【００４６】
表１において
ＥＧ ：エチレングリコール
ＮＰＧ：ネオペンチルグリコール
ＢＤ ：１，４−ブタンジオール
ＡｚＡ：アゼライン酸
ＡＡ ：アジピン酸
ｉＰＡ：イソフタル酸
△ ：反応系外に移行（この場合は、脱水）
【００４７】
［水性ポリウレタンエマルジョン組成物の合成例］
合成実施例２
攪拌機、温度計、窒素シール管、冷却器のついた反応器に、ＰＥＳ−１を３４３部、イソホロンジイソシアネート（以下、ＩＰＤＩと略称する）を１２６部、ジブチルチンジラウレート（以下、ＤＢＴＤＬと略称する）を０．０３部仕込み、８０℃で２時間反応させた。次いでこの反応液を５０℃まで冷却した後、２，２−ジメチロールプロピオン酸を２３．５部、トリエチルアミンを１７．７部、アセトンを１９４部を加えて３時間反応させた。さらにこの反応液にアセトンを２１６部を加えて３０℃まで冷却し、イソホロンジアミン（以下、ＩＰＤＡと略称する）が３５．４部、モノエタノ−ルアミン（以下、ＭＥＡと略称する）が１．３４部、イソプロピルアルコール（以下、ＩＰＡと略称する）が１０２部、水が７７７部からなる混合液を加えて高速攪拌し、この液よりアセトンとＩＰＡを留去して、固形分４０．５％、粘度８０ｃＰ／２５℃の水性ポリウレタンエマルジョン組成物ＰＵ−１を得た。
【００４８】
【００４９】
【００５０】
合成実施例３
合成実施例２と同様な反応器に、ＰＥＳ−１を１９６部、ネオペンチルグリコールを５２．０部、２，２−ジメチロールブタン酸を１４．８部、ＩＰＤＩを１５３部、アセトンを１４５部、ＤＢＴＤＬを０．０２部を仕込み、５０℃で１０時間反応させた。次いでこの反応液にトリエチルアミンを１０．１部、アセトンを２０９部を加えた後、水９６０部を加えて高速攪拌し、この液よりアセトンを留去して、固形分３０．２％、粘度８００ｃＰ／２５℃の水性ポリウレタンエマルジョン組成物ＰＵ−４を得た。
【００５１】
合成比較例３
合成実施例２と同様な反応器に、ＰＥＳ−４を３４５部、２，４−トルエンジイソシアネートを７０．１部、ＤＢＴＤＬを０．０３部を仕込み、８０℃で１時間反応させた。次いでこの反応液を５０℃まで冷却した後、２，２−ジメチロ−ルプロピオン酸を２３．５部、アセトンを１７０部を加えて３時間反応させた。さらにこの反応液にトリエチルアミン１７．７部、アセトン１７４部を加え、３０℃まで冷却し、ＩＰＤＡが８．４９部、ＭＥＡが０．３２０部、ＩＰＡが８６．０部、水が６５４部からなる混合液を加えて高速攪拌し、この液よりアセトンとＩＰＡを留去して、固形分３９．８％、粘度１０００ｃＰ／２５℃の水性ポリウレタンエマルジョン組成物ＰＵ−５を得た。
【００５２】
合成比較例４
合成実施例２と同様な反応器に、ＰＥＳ−５を２４９部、ネオペンチルグリコールを２６．０部、２，２−ジメチロールプロピオン酸を３３．０部、ＩＰＤＩを１６６部、アセトンを３４０部、ＤＢＴＤＬを０．０５部を仕込み、５０℃で１０時間反応させた。次いでこの反応液にトリエチルアミンを２５．２部、アセトンを８５部を加えた後、水１１６７部を加えて高速攪拌し、この液よりアセトンを留去して、固形分３０．１％、粘度５００ｃＰ／２５℃の水性ポリウレタンエマルジョン組成物ＰＵ−６を得た。
【００５３】
合成比較例５
合成実施例２と同様な反応器に、ポリオキシプロピレングリコール（水酸基価５６．１）を３４６部、ＩＰＤＩを７６．２部、ＤＢＴＤＬを０．０３部を仕込み、８０℃で２時間反応させた。次いでこの反応液を５０℃まで冷却した後、２，２−ジメチロールプロピオン酸を２３．５部、トリエチルアミンを１７．７部、アセトンを１７４部を加えて３時間反応させた。さらにこの反応液にアセトンを１８１部を加え、３０℃まで冷却し、ＩＰＤＡが１４．２部、ＭＥＡが０．５３５部、ＩＰＡが８８．６部、水が６７３部からなる混合液を加えて高速攪拌し、この液よりアセトンとＩＰＡを留去して、固形分４０．３％、粘度２００ｃＰ／２５℃の水性ポリウレタンエマルジョン組成物ＰＵ−７を得た。
【００５４】
合成実施例２及び合成比較例３〜５で得られた、ＰＵ−１〜７に使用した原料及び結果を表２、３に示す。
【００５５】
【表２】

【００５６】
【表３】

【００５７】
表２、３において
ＩＰＤＩ ：イソホロンジイソシアネート
ＤＢＴＤＬ ：ジブチルチンジラウレート
ＤＭＰＡ ：ジメチロールプロピオン酸
ＤＭＢＡ ：ジメチロールブタン酸
ＮＰＧ ：ネオペンチルグリコール
ＩＰＤＡ ：イソホロンジアミン
ＭＥＡ ：モノエタノールアミン
ＴＥＡ ：トリエチルアミン
ＩＰＡ ：イソプロピルアルコール
△ ：反応系外に移行（この場合は、脱溶剤）
ＰＰＧ−２０００：ポリオキシプロピレングリコール
（数平均分子量 約２０００)
ＴＤＩ ：２，４−トリレンジイソシアネート
【００５８】
［塗膜作成］
実施例１
ＰＵ−１を１００部、Ｎ−メチル−ピロリドン８部を配合し、クリアー塗料を調製した。この塗料を用いて、白色軟鋼板にバーコーターで乾燥塗膜３０〜４０μになるように塗装した。塗装後、８０℃で２０分間、さらに室温で５時間静置して塗装サンプルを作成した。
【００５９】
実施例４、比較例１〜３
ＰＵ−１の代わりにＰＵ−４〜７を用いてクリアー塗料を調製した。これらの塗料を実施例５と同様の方法で塗装サンプルを作成した。
【００６０】
実施例１、４及び比較例１〜３における塗膜の柔軟性、耐アルカリ性を評価した。柔軟性については、温冷繰り返し試験にて評価した（塗膜を−２０℃で１時間、５０℃で１時間放置する試験を１サイクルとし、１０サイクル後の塗膜外観を評価）。耐アルカリ性は、試験片を、０．１Ｎの水酸化ナトリウム水溶液に浸し、この状態で室温にて２４時間静置し、ＪＩＳ Ｋ−５４００の碁盤目試験にて評価した。実施例１、４及び比較例１〜３の塗膜の評価を表４に示す。
【００６１】
【表４】

【００６２】
［他樹脂との相溶性］
応用実施例１
アクロナール ＹＪ−２７３０Ｄ（アクリルエマルジョン 三菱化学ＢＡＳＦ製）／ＰＵ−１＝１００／１０（固形分換算比）に混合したものにキョウワノール Ｍ（造膜助剤 協和発酵工業製）を全固形分に対して１０部添加した。この混合エマルジョンを用いて厚さ１００μ（ドライ）のフィルムを作成した。キャスト条件は、室温×１０分＋８０℃×３０分＋室温×２日である。得られたキャストフィルムをＪＩＳ Ｋ−６３０１記載の２号ダンベルに打ち抜いて試験片とした。
【００６３】
応用実施例４、応用比較例１〜３
ＰＵ−１の代わりにＰＵ−２〜７を用いてキャストフィルムを作成して、ＪＩＳ Ｋ−６３０１記載の４号ダンベルに打ち抜いて試験片とした。
【００６４】
得られた試験片は、引っ張り速度２００ｍｍ／分にて引っ張り試験を行い、伸びを測定した。（ポリウレタン系樹脂とアクリル樹脂との相溶性は、伸びがあるほど良好となる。）表５に伸び測定結果を示す。
【００６５】
【表５】

[0001]
[Industrial application fields]
  The present inventionWater-based polyurethane emulsion paintAbout. More specifically, organic polyisocyanates, active hydrogen group-containing compounds containing specific polyester polyols, hydrophilic polar group-containing active hydrogen compoundsWater-based polyurethane emulsion paint obtained by reactionIt is about.
[0002]
[Prior art]
  Paints, adhesives and coating agents containing organic solvents have adverse effects on human bodies, safety and health problems such as explosion and fire, and pollution problems such as air pollution and water pollution. In order to improve these problems, the development of water system has been actively conducted in recent years. Various resins such as an acrylic resin, a polyurethane resin, a polyester resin, and a latex are used as the resin for the aqueous system. Among them, polyurethane resin is excellent in durability, abrasion resistance, and the like, and therefore, attempts to apply it to an aqueous system in various usages are widely made. For example, JP-A-61-36314 discloses an aqueous polyester urethane resin composition, JP-A-4-198361 discloses a water-dispersible polyurethane-based paint, and JP-A-5-117358 discloses water-dispersibility. Polyurethane adhesives are disclosed. These are water-based polyurethane resins alone, but in order to combine the characteristics of each resin, a combination of various resins such as an acrylic emulsion and a polyurethane emulsion has been studied.
[0003]
[Problems to be solved by the invention]
  However, the aqueous polyester urethane resin composition described in JP-A-61-36314 has poor compatibility with other resins, particularly acrylic resins, and is described in JP-A-4-198361 and JP-A-5-117358. There is basically no water-based polyurethane resin that satisfies all required performance such as adhesion, adhesion, and alkali resistance, and the appearance of such a resin has been desired.
[0004]
[Means for Solving the Problems]
  As a result of intensive studies, the present inventors have been composed of an organic polyisocyanate, an active hydrogen group-containing compound containing a specific polymer polyol, and a hydrophilic polar group-containing active hydrogen compound.Water-based polyurethane emulsion paintThus, it has been found that such conventional problems can be improved, and the present invention has been achieved.
[0005]
  That is,The present invention is shown below.
[0006]
[0007]
(I) Isophorone diisocyanate
(B) The low molecular polyol is ethylene glycol or neopentyl glycol, Hydrogen containing an aliphatic polycarboxylic acid is isophthalic acid, an aliphatic polycarboxylic acid is azelaic acid, and a polyester polyol having a mass ratio of aromatic polycarboxylic acid to aliphatic polycarboxylic acid of 35/65 to 65/35 Group-containing compounds
(C) 2,2-dimethylolpropionic acid and / or 2,2-dimethylolbutanoic acid
Water-based polyurethane emulsion paint obtained by reacting
[0008]
DETAILED DESCRIPTION OF THE INVENTION
[0009]
  Water-based polyurethane emulsion of the present inventionThe (a) organic polyisocyanate constituting the polyurethane resin in the coating is isophorone diisocyanate.
[0010]
  Water-based polyurethane emulsion of the present inventionConstruct polyurethane resin in paint(B) The active hydrogen group-containing compound contains a specific polyester polyol composed of a low molecular polyol, an aromatic polycarboxylic acid and an aliphatic polycarboxylic acid. The amount of the polyurethane resin introduced is preferably 1 to 80% by weight, particularly preferably 3 to 70% by weight.
[0011]
  The polyester polyol used in the present invention has a number average molecular weight of 300 to 7,000 in consideration of the compatibility between the obtained aqueous polyurethane and an acrylic resin, and the low and low molecular weight polyols are ethylene glycol and neopentyl glycol. The aromatic polycarboxylic acid is isophthalic acid, the aliphatic polycarboxylic acid is azelaic acid, the mass ratio of the aromatic polycarboxylic acid and the aliphatic polycarboxylic acid is 35/65 to 65/35,It is produced by a known method.
[0012]
[0013]
  The active hydrogen group-containing compounds that can be used in the present invention are broadly classified into polymer polyols and chain extenders. Examples of the polymer polyol include polyester polyols other than the above-described polyester polyols having a number average molecular weight of 300 to 7,000, polyether polyols, polycarbonate polyols, and polyolefin polyols.
[0014]
  In addition, as the polyester polyol that can be used in the present invention, one or more of the above-described low molecular weight polyols, aromatic dicarboxylic acid, aliphatic dicarboxylic acid, 1,4-cyclohexyl dicarboxylic acid, α-hydromuconic acid, β- Other poly, such as hydromuconic acid, α-butyl-α-ethylglutaric acid, α, β-diethylsuccinic acid, maleic acid, fumaric acid, hemimellitic acid, trimellitic acid, pyromellitic acid, benzophenone tetracarboxylic acid, etc. It is a polyester polyol produced by a known method using one or more kinds from carboxylic acid. In addition, polyester polyols obtained by ring-opening polymerization of a cyclic ester compound can also be used.
[0015]
  Examples of the polyether polyol include those obtained by addition polymerization reaction of a compound having two or more active hydrogen groups such as the above-mentioned low molecular polyols and polyamines alone or a mixture of two or more with alkylene oxide. .
[0016]
  Examples of the polycarbonate polyol include a polyol obtained by a dephenol reaction of a low molecular polyol that can be used for the polyester polyol and diphenyl carbonate, a polyol obtained by a dealcoholization reaction of the low molecular polyol and a dialkyl carbonate, and the like. There is.
[0017]
  Examples of the polyolefin polyol include hydroxyl group-containing polybutadiene, hydroxyl group-containing polyisoprene, hydroxyl group-containing hydrogenated polybutadiene, hydroxyl group-containing hydrogenated polyisoprene, hydroxyl group-containing chlorinated polyethylene, and hydroxyl group-containing chlorinated polypropylene.
[0018]
  Examples of the chain extender include water having a molecular weight of less than 18 to 300, urea, low molecular polyols, low molecular polyamines, and low molecular amino alcohols. Examples of the low molecular polyol include ethylene glycol constituting the polyester polyol described above.
[0019]
  Low molecular weight polyamines include ethylenediamine, propylenediamine, diethylenetriamine, triethylenetetramine, toluenediamine, metaphenylenediamine, diphenyldimethanediamine, xylylenediamine, isophoronediamine, hydrogenated tolylenediamine, hydrogenated xylenediamine, hydrogenated Examples thereof include polyamines such as diphenylmethanediamine, hydrogenated tetramethylxylenediamine, hydrazine and diethylenetriamine, and dicarboxylic acid hydrazides such as carbohydrazide, adipic acid hydrazide and isophthalic acid hydrazide.
[0020]
  Examples of low molecular amino alcohols include monoethanolamine and diethanolamine.
[0021]
  Of these low-molecular polyols, low-molecular polyamines, and low-molecular amino alcohols, alicyclic amines are preferred, and isophorone diamine is particularly preferred in consideration of weather resistance, production method, and the like.
[0022]
  Water-based polyurethane emulsion of the present inventionConstruct polyurethane resin in paint(C) The hydrophilic polar group of the hydrophilic polar group and the active hydrogen group-containing compound is a nonionic, anionic or cationic hydrophilic polar group. As the hydrophilic polar group introduction source, poly ( Nonionic hydrophilic polar groups such as (oxyethylene) ether, anionic hydrophilic polar groups such as -COOM, -SO3M (M represents an alkali metal, ammonium group, or organic amine). There are such cationic hydrophilic polar groups.
[0023]
  Examples of the nonionic hydrophilic polar group introduction source include poly (oxyalkylene) ethers and polyoxyalkylene fatty acid esters containing one or more active hydrogen groups. Examples of active hydrogen group-containing compounds used as initiators for the production of poly (oxyalkylene) ethers include methanol, n-butanol, cyclohexanol, phenol, ethylene glycol, propylene glycol, aniline, trimethylolpropane, and glycerin. . Among these, in consideration of dispersion stability, it is preferable to use an alcohol having a smaller molecular weight such as methanol, ethanol, or ethylene glycol because the hydrophilicity is higher. Moreover, as a fatty acid used for manufacture of polyoxyalkylene fatty acid ester, an acetic acid, propionic acid, a butyric acid, etc. are mentioned. Among these, when considering dispersion stability, it is preferable to use a lower fatty acid because the hydrophilicity is higher. Further, the polyether chain present in the polyalkylene ether alcohol, polyoxyalkylene fatty acid ester, etc. is generally 3 to 90, particularly preferably 5 to 50 pure ethylene oxide chains and / or all alkylene oxide units. A mixed alkylene oxide chain containing at least 70% ethylene oxide units may be used.
[0024]
  The anionic hydrophilic polar group introduction source is composed of an organic acid having one or more active hydrogen groups and a neutralizing agent. As organic acids, α-oxypropionic acid, oxysuccinic acid, dioxysuccinic acid, ε-oxypropane-1,2,3-tricarboxylic acid, hydroxyacetic acid, α-hydroxybutyric acid, hydroxystearic acid, ricinoleic acid, ricinoelaidic acid Hydroxyl fatty acid obtained by hydroxylating unsaturated fatty acids such as oleic acid, ricinoleic acid, linoleic acid, glutamine, asparagine, lysine, diaminopropionic acid, ornithine, diaminobenzoic acid, diamino Diamine type amino acids such as benzene sulfonic acid, monoamine type amino acids such as glycine, alanine, glutamic acid, taurine, aminocaproic acid, aminobenzoic acid, aminoisophthalic acid, sulfamic acid, etc., or 2,2-dimethylolpropion , 2,2-dimethylolbutanoic acid, 2,2-dimethylolbutyric acid, carboxylic acid-containing polyols such as 2,2-dimethylolvaleric acid, adducts of iminodiacetic acid and glycidol, polyester polyols using 5-hydroxysulfoisophthalic acid And a transesterified product of a polycaprolactone polyol, a polyester polyol or a polycarbonate polyol and a carboxylic acid-containing polyol using a carboxylic acid-containing polyol as an initiator. Moreover, the half ester mixture and half amide mixture containing the carboxyl group obtained by making polyols and polyamines, such as a high molecular polyol and a low molecular polyol mentioned above, and a polycarboxylic anhydride can also be used. In particular, when a polyol is added to an acid anhydride such as pyromellitic anhydride, two carboxylic acids are formed, so that a hydrophilic polar group can be introduced into the molecular chain of the polyester polyol. Examples of other anionic hydrophilic groups include phosphoric acid.
[0025]
  As a neutralizing agent, ammonia, ethylamine, trimethylamine, triethylamine, triisopropylamine, tributylamine, triethanolamine, N-methyldiethanolamine, N-phenyldiethanolamine, monoethanolamine, dimethylethanolamine, diethylethanolamine, morpholine, N -Organic amines such as methylmorpholine and 2-amino-2-ethyl-1-propanol; alkali metals such as lithium, potassium and sodium; inorganic alkalis such as sodium hydroxide and potassium hydroxide; In order to improve the weather resistance and water resistance, those having high volatility that are easily dissociated by heat are preferable, and ammonia, trimethylamine, and triethylamine are preferable. These organic acids and neutralizing agents can be used alone or in a mixture of two or more.
[0026]
  The cationic polar group introduction source consists of a tertiary amine containing one or more active hydrogen groups capable of reacting with an isocyanate group, an inorganic acid, an organic acid, and a quaternizing agent. As the tertiary amine, N-methyldiethanolamine, N-ethyldiethanolamine, or N-alkyldiethanolamine having an alkyl chain having a carbon number greater than 2, N-phenyldiethanolamine, N-phenyldipropanolamine, N-methyldiisopropanolamine, N, N'-dihydroxyethylpiperazine, triethanolamine, trisisopropanolamine, N, N'-dimethylethanolamine, N-methyl-bis- (3-aminopropyl) -amine, N-methyl-bis- (2- Aminopropyl) -amine and the like.
[0027]
  Examples of inorganic and organic acids include hydrochloric acid, acetic acid, lactic acid, cyanoacetic acid, phosphoric acid, and sulfuric acid. Examples of the quaternizing agent include dimethyl sulfate, benzyl chloride, bromoacetamide, chloroacetamide, or alkyl halides such as ethyl bromide, propyl bromide, and butyl bromide. Other cationic hydrophilic polar group-containing compounds include cationic compounds such as primary amine salts, secondary amine salts, tertiary amine salts, and pyridinium salts.
[0028]
  Also, amphoteric compounds such as a reaction product of a tertiary amine-containing polyol and sulfobetaine can be used.
[0029]
  Among the hydrophilic polar group introduction source, in consideration of weather resistance, production method, etc., a combination of a carboxylic acid-containing low molecular polyol that is an anionic hydrophilic polar group and an amine neutralizer is preferable, In particular, a combination of 2,2-dimethylolpropionic acid and / or 2,2-dimethylolbutanoic acid and triethylamine is preferable.
[0030]
  The anionic and cationic hydrophilic polar groups are finally introduced into the polyurethane resin in the form of a salt. However, the anionic and cationic hydrophilic polar groups may be introduced into the resin after neutralization. It may be neutralized after introduction.
[0031]
  The nonionic hydrophilic polar group introduction amount is preferably 0.1 to 40% by weight in the polyurethane resin, and the anionic or cationic hydrophilic polar group introduction amount is preferably 0.1 to 1.0 mmol / g. The amount is 1 to 30% by weight in the nonionic system and 0.2 to 0.8 mmol / g in the anionic and cationic systems. When the amount of each hydrophilic polar group introduced is less than the lower limit, the water dispersion stability of the polyurethane resin is deteriorated. Moreover, when the hydrophilic polar group introduction amount exceeds the upper limit, the water resistance of the coating film is deteriorated.
[0032]
  Of the present inventionWater-based polyurethane emulsion paintA reaction terminator may be used as necessary. Specific examples of the reaction terminator include monoalcohols such as methanol, ethanol and propanol, primary and secondary monoamines such as ethylamine, butylamine, diethylamine and dibutylamine, aminoalcohols described above, and the like.
[0033]
  Of the present inventionAqueous polyurethane emulsion in aqueous polyurethane emulsion paintAs a production method, an isocyanate group-terminated prepolymer is synthesized by reacting an active hydrogen compound with an organic diisocyanate in excess of an isocyanate group, and then reacting in an atmosphere containing an active hydrogen compound-containing compound in excess, It can be produced by a known method such as a prepolymer method in which an active hydrogen compound is reacted. Alternatively, the resin may be dispersed in water after synthesis, or it may be obtained by a method of reacting an active hydrogen-containing compound simultaneously with emulsification of the isocyanate group-terminated prepolymer or after emulsification. When an organic solvent is used, it may be removed after production or may remain, but it is preferable to remove it in consideration of health and safety.
[0034]
  In the case of using an organic solvent, examples of usable organic solvents include aromatics such as toluene, xylene, swazol (aromatic hydrocarbon solvent manufactured by Cosmo Oil), and Solvesso (aromatic hydrocarbon solvent manufactured by Exxon Chemical). Solvents, acetone solvents such as methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone, alcohol solvents such as methanol, ethanol and isopropanol, ester solvents such as ethyl acetate, butyl acetate and isobutyl acetate, ethylene glycol ethyl ether acetate , Glycol ether ester solvents such as propylene glycol methyl ether acetate, 3-methyl-3-methoxybutyl acetate and ethyl-3-ethoxypropionate, ethers such as tetrahydrofuran and dioxane Examples include tellurium solvents. The said solvent can be used 1 type, or 2 or more types.
[0035]
  In the case of the one-shot method, the ratio of isocyanate group / active hydrogen group is 0.5 to less than 1 and preferably 0.7 to less than 1 in terms of molar ratio. When it is less than 0.5, the molecular weight of the polyurethane resin is too small, so that it lacks durability. In the case of 1 or more, gelation tends to occur when the resin is synthesized.
[0036]
  In the case of the prepolymer method, the ratio of isocyanate group / active hydrogen group during prepolymer synthesis is 1.1 to 5.0, preferably 1.1 to 4.0. If it is less than 1.1, the molecular weight of the prepolymer becomes too large and the viscosity is too large, so that it is difficult to proceed to the subsequent reaction step. If it exceeds 5.0, the adhesion is poor.
[0037]
  As the reaction catalyst for synthesizing the isocyanate group-containing prepolymer and polyurethane resin used in the present invention, a known so-called urethanization catalyst can be used. Specific examples include organic metal compounds such as dibutyltin dilaurate, organic amines such as triethylenediamine, and salts thereof.
[0038]
  Of the present inventionWater-based polyurethane emulsion paintIn addition, additives and auxiliaries commonly used in aqueous systems can be used as necessary. For example, pigments, antiblocking agents, dispersion stabilizers, viscosity modifiers, leveling agents, antigelling agents, light stabilizers, antioxidants, UV absorbers, inorganic and organic fillers, plasticizers, lubricants, antistatic agents Further, a reinforcing material, a catalyst and the like can be added.
[0039]
  Polyurethane emulsion of the present inventionPolyurethane emulsion in paintCan be blended with other resin emulsions. For example, acrylic emulsion, polyester emulsion, polyolefin emulsion, latex and the like.
[0040]
  The aqueous emulsion paint of the present invention isThe aforementioned water-based polyurethane emulsionPigments and dyes are added to the water, water for adjusting the solid content and viscosity, organic solvents such as isopropanol and N-methyl-pyrrolidone for adjusting the surface tension, anti-blocking agents, dispersion stabilizers, thixotropic agents, and antioxidants. Additives such as additives, ultraviolet absorbers, antifoaming agents, thickeners, dispersants, surfactants, catalysts, fillers, lubricants, antistatic agents, plasticizers, and ball mills, sand grind mills, etc. can get. The obtained paint is applied using a brush, spray or the like. In addition, you may add and use a hardening | curing agent just before application | coating as needed. Specific examples of the curing agent include polyisocyanate curing agents such as Aquanate-100 and 200 manufactured by Nippon Polyurethane Industry.
[0041]
【The invention's effect】
  The water-based polyurethane emulsion paint of the present invention exhibited excellent performances such as adhesion, alkali resistance, and compatibility with other resins by using a specific polyester polyol. Moreover, the coating film appearance, flexibility and the like were also good.
[0042]
【Example】
  Next, although the Example and comparative example of this invention are demonstrated in detail, this invention is not limited to these Examples. Unless otherwise specified, “parts” and “%” in the examples mean “parts by weight” and “% by weight”, respectively.
[0043]
[Synthesis example of polyester polyol]
Synthesis Example 1
  A reactor equipped with a stirrer, thermometer, nitrogen seal tube, and condenser was charged with 28 parts of ethylene glycol, 416 parts of neopentyl glycol, 371 parts of azelaic acid, and 327 parts of isophthalic acid, and reacted at 180 ° C for 5 hours. The polyester polyol PES-1 having a hydroxyl value of 55.6 mgKOH / g and an acid value of 0.5 mgKOH / g was obtained by reacting at 200 ° C. under a reduced pressure of 2 to 10 mmHg.
[0044]
Synthesis Comparative Examples 1 and 2
  Polyester polyol PES- in the same manner as in Example 14, 5Manufactured. Table 1 shows the raw materials and specifications used.
[0045]
[Table 1]

[0046]
  In Table 1
  EG: Ethylene glycol
  NPG: Neopentyl glycol
  BD: 1,4-butanediol
  AzA: Azelaic acid
  AA: Adipic acid
  iPA: Isophthalic acid
  Δ: Moved out of reaction system (in this case, dehydration)
[0047]
[Synthesis Example of Aqueous Polyurethane Emulsion Composition]
Synthesis Example 2
  In a reactor equipped with a stirrer, thermometer, nitrogen seal tube, and condenser, 343 parts of PES-1, 126 parts of isophorone diisocyanate (hereinafter abbreviated as IPDI), dibutyltin dilaurate (hereinafter abbreviated as DBTDL) 0.03 parts was charged and reacted at 80 ° C. for 2 hours. Next, the reaction solution was cooled to 50 ° C., 23.5 parts of 2,2-dimethylolpropionic acid, 17.7 parts of triethylamine and 194 parts of acetone were added and reacted for 3 hours. Further, 216 parts of acetone was added to this reaction liquid and cooled to 30 ° C., and 35.4 parts of isophoronediamine (hereinafter abbreviated as IPDA) and 1.34 parts of monoethanolamine (hereinafter abbreviated as MEA). Then, a mixed solution consisting of 102 parts of isopropyl alcohol (hereinafter abbreviated as IPA) and 777 parts of water is added and stirred at a high speed. Acetone and IPA are distilled off from this liquid to obtain a solid content of 40.5% and a viscosity. An aqueous polyurethane emulsion composition PU-1 at 80 cP / 25 ° C. was obtained.
[0048]
[0049]
[0050]
Synthesis Example 3
  Synthesis Example 2196 parts of PES-1, 52.0 parts of neopentyl glycol, 14.8 parts of 2,2-dimethylolbutanoic acid, 153 parts of IPDI, 145 parts of acetone and 0 of DBTDL. .02 parts were charged and reacted at 50 ° C. for 10 hours. Next, 10.1 parts of triethylamine and 209 parts of acetone were added to this reaction liquid, and then 960 parts of water was added and stirred at a high speed. The acetone was distilled off from this liquid to obtain a solid content of 30.2% and a viscosity of 800 cP. / 25 degreeC aqueous polyurethane emulsion composition PU-4 was obtained.
[0051]
Synthesis Comparative Example 3
  Synthesis Example 2In the same reactor, 345 parts of PES-4, 70.1 parts of 2,4-toluene diisocyanate, and 0.03 part of DBTDL were charged and reacted at 80 ° C. for 1 hour. The reaction solution was then cooled to 50 ° C., and 23.5 parts of 2,2-dimethylolpropionic acid and 170 parts of acetone were added and reacted for 3 hours. Further, 17.7 parts of triethylamine and 174 parts of acetone were added to this reaction liquid, and cooled to 30 ° C., consisting of 8.49 parts of IPDA, 0.320 parts of MEA, 86.0 parts of IPA, and 654 parts of water. The mixed solution was added and stirred at high speed, and acetone and IPA were distilled off from this solution to obtain an aqueous polyurethane emulsion composition PU-5 having a solid content of 39.8% and a viscosity of 1000 cP / 25 ° C.
[0052]
Synthesis Comparative Example 4
  Synthesis Example 2249 parts of PES-5, 26.0 parts of neopentyl glycol, 33.0 parts of 2,2-dimethylolpropionic acid, 166 parts of IPDI, 340 parts of acetone and 0 of DBTDL. .05 parts was charged and reacted at 50 ° C. for 10 hours. Next, 25.2 parts of triethylamine and 85 parts of acetone were added to the reaction liquid, and then 1167 parts of water were added and stirred at a high speed. The acetone was distilled off from this liquid to obtain a solid content of 30.1% and a viscosity of 500 cP. / 25 degreeC aqueous polyurethane emulsion composition PU-6 was obtained.
[0053]
Synthesis Comparative Example 5
  Synthesis Example 2In a similar reactor, 346 parts of polyoxypropylene glycol (hydroxyl value 56.1), 76.2 parts of IPDI, and 0.03 part of DBTDL were charged and reacted at 80 ° C. for 2 hours. Next, the reaction solution was cooled to 50 ° C., 23.5 parts of 2,2-dimethylolpropionic acid, 17.7 parts of triethylamine and 174 parts of acetone were added and reacted for 3 hours. Further, 181 parts of acetone was added to the reaction liquid, cooled to 30 ° C., and a mixed liquid consisting of 14.2 parts of IPDA, 0.535 parts of MEA, 88.6 parts of IPA, and 673 parts of water was added. The mixture was stirred at high speed, and acetone and IPA were distilled off from this solution to obtain an aqueous polyurethane emulsion composition PU-7 having a solid content of 40.3% and a viscosity of 200 cP / 25 ° C.
[0054]
  In Synthesis Example 2 and Synthesis Comparative Examples 3-5The obtained raw materials and results used for PU-1 to 7 are shown in Tables 2 and 3.
[0055]
[Table 2]

[0056]
[Table 3]

[0057]
  In Tables 2 and 3
  IPDI: Isophorone diisocyanate
  DBTDL: Dibutyltin dilaurate
  DMPA: dimethylolpropionic acid
  DMBA: dimethylol butanoic acid
  NPG: Neopentyl glycol
  IPDA: Isophoronediamine
  MEA: Monoethanolamine
  TEA: Triethylamine
  IPA: Isopropyl alcohol
  Δ: Moved out of reaction system (in this case, solvent removal)
  PPG-2000: Polyoxypropylene glycol
                  (Number average molecular weight 2,000)
  TDI: 2,4-tolylene diisocyanate
[0058]
[Coating creation]
Example 1
  A clear paint was prepared by blending 100 parts of PU-1 and 8 parts of N-methyl-pyrrolidone. Using this paint, a white mild steel sheet was coated with a bar coater so as to have a dry coating thickness of 30 to 40 μm. After coating, the sample was left standing at 80 ° C. for 20 minutes and further at room temperature for 5 hours to prepare a coating sample.
[0059]
Example 4, Comparative Examples 1-3
  Instead of PU-1PU-4-7Was used to prepare a clear paint. Samples of these paints were prepared in the same manner as in Example 5.
[0060]
  Examples 1 and 4 and Comparative Examples 1 to 3The flexibility and alkali resistance of the coating film were evaluated. The flexibility was evaluated by a repeated heating / cooling test (the test in which the coating film was allowed to stand at −20 ° C. for 1 hour and 50 ° C. for 1 hour was defined as one cycle, and the coating film appearance after 10 cycles was evaluated). The alkali resistance was evaluated by a cross-cut test of JIS K-5400 by immersing a test piece in a 0.1N sodium hydroxide aqueous solution and leaving the test piece in this state at room temperature for 24 hours.Examples 1 and 4 and Comparative Examples 1 to 3Table 4 shows the evaluation of these coating films.
[0061]
[Table 4]

[0062]
[Compatibility with other resins]
Application Example 1
  Acronal YJ-2730D (acrylic emulsion manufactured by Mitsubishi Chemical BASF) / PU-1 = 100/10 (solid content conversion ratio) mixed with Kyowanol M (film-forming aid Kyowa Hakko Kogyo Co., Ltd.) for the total solid content 10 parts were added. Using this mixed emulsion, a 100 μm (dry) film was prepared. Casting conditions are room temperature × 10 minutes + 80 ° C. × 30 minutes + room temperature × 2 days. The obtained cast film was punched into No. 2 dumbbell described in JIS K-6301 to obtain a test piece.
[0063]
Application Example 4, Application Comparative Examples 1-3
  A cast film was prepared using PU-2 to 7 instead of PU-1, and punched into a No. 4 dumbbell described in JIS K-6301 to obtain a test piece.
[0064]
  The obtained test piece was subjected to a tensile test at a pulling speed of 200 mm / min, and the elongation was measured. (The compatibility between the polyurethane resin and the acrylic resin becomes better as the elongation increases.) Table 5 shows the elongation measurement results.
[0065]
[Table 5]

Claims (1)

(I) Isophorone diisocyanate
(B) The low molecular polyol is ethylene glycol and neopentyl glycol, the aromatic polycarboxylic acid is isophthalic acid, the aliphatic polycarboxylic acid is azelaic acid, the mass ratio of the aromatic polycarboxylic acid and the aliphatic polycarboxylic acid Active hydrogen group-containing compound containing a polyester polyol having a ratio of 35/65 to 65/35
(C) 2,2-dimethylolpropionic acid and / or 2,2-dimethylolbutanoic acid
Water-based polyurethane emulsion paint obtained by reacting