JP4178370B2 - Two-component curable polyisocyanate curing agent, and adhesive and paint using the same - Google Patents

Description

【００２０】
（Ｂ）には、モノエステル、ジエステル、トリエステルの３種類があり、モノ−（トリメチルシリル）ホスフェート、ジ−（トリメチルシリル）ホスフェート、トリス−（トリメチルシリル）ホスフェート、モノ−（トリエチルシリル）ホスフェート、ジ−（トリエチルシリル）ホスフェート、トリス−（トリエチルシリル）ホスフェート、モノ−（トリブチルシリル）ホスフェート、ジ−（トリブチルシリル）ホスフェート、トリス−（トリブチルシリル）ホスフェート、モノ−（トリフェニルシリル）ホスフェート、ジ−（トリフェニルシリル）ホスフェート、トリス−（トリフェニルシリル）ホスフェート、トリメチルシリルホスフェート、トリエチルシリルホスフェート、トリブチルシリルホスフェート、モノ−（２−エチルヘキシルシリル）ホスフェート、ジ−（２−エチルヘキシルシリル）ホスフェート、トリス−（２−エチルヘキシルシリル）ホスフェート、モノ−（トリメチルシリル）ホスファイト、ジ−（トリメチルシリル）ホスファイト、トリス−（トリメチルシリル）ホスファイト、モノ−（トリエチルシリル）ホスファイト、ジ−（トリエチルシリル）ホスファイト、トリス−（トリエチルシリル）ホスファイト、モノ−（トリブチルシリル）ホスファイト、ジ−（トリブチルシリル）ホスファイト、トリス−（トリブチルシリル）ホスファイト、モノ−（トリフェニルシリル）ホスファイト、ジ−（トリフェニルシリル）ホスファイト、トリス−（トリフェニルシリル）ホスファイト、モノメチルシリルホスファイト、ジメチルシリルホスファイト、トリメチルシリルホスファイト等が挙げられる。本発明では、亜リン酸モノエステルタイプ、リン酸トリエステルタイプが好ましい。
【００２１】
（Ｂ）の添加量は、前記イソシアネート基末端ウレタンプレポリマー（Ａ）に対して、０．０００１〜５．０質量％が好ましく、特に好ましくは０．０００１〜１質量％である。また、（Ｂ）の添加時期については、有機ポリイソシアネート（Ａ１）とポリオール（Ａ２）との反応の前後を問わないが、反応後が好ましい。
【００２２】
（Ｂ）の効果とするところは、ポリイソシアネート溶液の貯蔵期間中における湿気等の活性水素化合物との反応を抑制することによる貯蔵安定性の向上を図ることである。
【００２３】
本発明に用いられる有機溶剤（Ｃ）は、ポリウレタン工業において常用の、イソシアネート基に対して不活性の溶剤であり、例えばトルエン、キシレン等の芳香族系溶剤、アセトン、メチルエチルケトン、メチルイソブチルケトン、シクロヘキサノン等のケトン系溶剤、酢酸エチル、酢酸ブチル、酢酸イソブチル等のエステル系溶剤、エチレングリコールエチルエーテルアセテート、プロピレングリコールメチルエーテルアセテート、３−メチル−３−メトキシブチルアセテート、エチル−３−エトキシプロピオネート等のグリコールエーテルエステル系溶剤、テトラヒドロフラン、ジオキサン等のエーテル系溶剤等が挙げられる。これらは、１種又は２種以上混合して使用することができる。
【００２４】
本発明におけるポリイソシアネート溶液の固形分は、１０〜９０質量％が好ましく、特に好ましくは２０〜８０質量％である。また、イソシアネート含量は、溶液状態で１〜３０質量％が好ましく、特に好ましくは２〜２５質量％である。
【００２５】
本発明の接着剤及び塗料は、前述のポリイソシアネート溶液を二液硬化型の硬化剤として用いることを特徴とするものである。接着剤及び塗料は、一液タイプと二液タイプとに大別される。また、一液タイプは、ポリイソシアネート溶液中のイソシアネート基を更にブロック剤で封鎖したものを潜在性硬化剤として、あらかじめ主剤としての多価ヒドロキシル化合物に配合したタイプと、単独で用いて湿気硬化させるタイプがある。二液タイプは、前述のポリイソシアネート溶液を硬化剤として、使用直前にこれと主剤としての多価ヒドロキシル化合物を配合して使用するものである。本発明では、主剤としての多価ヒドロキシル化合物を配合して使用する二液タイプが好ましい。
【００２６】
本発明に用いられるポリイソシアネート溶液を二液硬化型の硬化剤として用いる二液タイプの塗料や接着剤において、主剤に用いられる多価ヒドロキシル化合物としては、前記のポリオール（Ａ２）だけでなく、分子内に二個以上の水酸基を有する数平均分子量５００〜１００、０００の化合物が好ましい。具体的には、飽和又は不飽和ポリエステルポリオール、ポリカプロラクトンポリオール、飽和又は不飽和の油変性又は脂肪酸変性アルキッドポリオール、アミノアルキッドポリオール、ポリカーボネートポリオール、アクリルポリオール、ポリエーテルポリオール、エポキシポリオール、含フッ素ポリオール、更には飽和又は不飽和ポリエステル樹脂、ポリカプロラクトン樹脂、飽和又は不飽和の油変性又は脂肪酸変性アルキッド樹脂、アミノアルキッド樹脂、ポリカーボネート樹脂、アクリル樹脂、ポリエーテル樹脂、エポキシ樹脂、ポリウレタン樹脂、セルロースアセテートブチラート樹脂、含フッ素樹脂等が挙げられる。
【００２７】
本発明の接着剤及び塗料において、ポリイソシアネート組成物中の（潜在する）イソシアネート基と多価ヒドロキシル化合物中の水酸基とのモル比は、９：１〜１：９、好ましくは７：３〜３：７の範囲である。本発明の組成物は、後述する溶剤の他にラッカー工業に常用の各種顔料及び各種添加剤等を含んでいてもよい。更に、本発明の組成物は従来より行なわれている通常の塗装方法によって塗装することができ、塗装にはエアレススプレー機、エアスプレー機、静電塗装機、浸漬、ロールコーター、ナイフコーター、ハケ等を用いることができる。
【００２８】
本発明では、必要に応じて、前述のウレタン化触媒を更に配合して用いることができる。触媒の添加量は、前記イソシアネート基末端ウレタンプレポリマーに対して、０．０１〜２０質量％が好ましい。その添加量が前記下限値未満である場合には、硬化反応が不充分で、目的とした物性を得られない。
【００２９】
また、更に本発明の接着剤・塗料には、セメント、高炉スラグ、石こう、炭酸カルシウム、粘土、水酸化アルミニウム、三酸化アンチモン、生石灰、消石灰、ベントナイト等の無機充填剤や、レベリング剤、難燃剤、老化防止剤、耐熱性付与剤、抗酸化剤等を適宜配合量を調整して配合することができる。
【００３０】
【発明の効果】
本発明の二液硬化型ポリイソシアネート硬化剤に用いられるポリイソシアネート溶液は、イソシアネート基の反応による経時変化が少ないので、色数や粘度の増大といった劣化が少なく、貯蔵安定性の向上にもつながる。更に後述するように、接着性や密着性の向上にも効果があるので、良好な性能の接着剤、塗料が得られる。
【００３１】
【実施例】
次に、本発明のポリイソシアネート組成物及びそれを用いた接着剤、塗料を、実施例に基づいて更に詳細に説明するが、本発明はかかる実施例のみに限定されるものではない。
【００３２】
［ポリイソシアネート組成物の合成］
実施例２
撹拌機、温度計、還流冷却器及び窒素ガス導入管のついた、容量が１，０００ｍｌの反応器に、コロネートＴ−８０を１００ｇ、１，３−ＢＤを３ｇ、ＴＭＰを５ｇ、Ｇｌｙを２ｇ仕込み、撹拌しながら７０〜８０℃に加熱し、目標のＮＣＯ含量に達するまでウレタン化反応を進めた。その後シリルエステル、及び有機溶剤で希釈してポリイソシアネート溶液Ｐ−１を合成した。合成結果を表１に示す。
【００３３】
実施例３〜４、比較例１〜３
撹拌機、温度計、還流冷却器及び窒素ガス導入管のついた、容量が３００ｍｌの反応器に、イソシアネート及びポリオールを所定量仕込んだ。これを撹拌しながら７０〜８０℃に加熱し、目標のＮＣＯ含量に達するまでウレタン化反応を進めた。そしてその後、この反応液中の未反応のＴＤＩ（又はＨＤＩ）を１２０〜１４０℃、１〜５Ｐａで薄膜蒸留により、残留の遊離ジイソシアネート含有量が０．５質量％以下になるように除去し、その後シリルエステル又は安定化剤、及び有機溶剤で希釈してポリイソシアネート溶液Ｐ−３、４、６〜８を合成した。合成結果を表１、２に示す。
【００３４】
［溶剤希釈性試験方法］
一般的にポリイソシアネートは、末端にイソシアネート基を有しているため、貯蔵期間中に湿気との反応等により高分子量化し溶剤への溶解性が低下する。そこで、貯蔵安定性の一つの指標として以下に述べる溶剤希釈性試験を用いて判定した。
【００３５】
ポリイソシアネート溶液を５ｇ採取し、ビュレットにてトルエンを少しずつ加え、よく振り混ぜて濁ったところを終点とし、その時の溶剤の所要ｍｌ数を求めた。そして次の式にて溶剤希釈性（倍）を求めた。この値が大きいほど溶剤希釈性に優れている。その結果を表１に示す。
溶剤希釈性（倍）＝溶剤の所要ｍｌ数／サンプル量（５ｇ）
【００３６】
【表１】

【００３７】
【表２】

【００３８】
表１、２において
ミリオネートＭＴＬ：ＭＤＩのカルボジイミド変性ポリイソシアネート
日本ポリウレタン工業製
イソシアネート含量＝２９．０％
固形分＝１００％
コロネートＴ−８０：２，４−ＴＤＩと２，６−ＴＤＩの混合物
２，４−ＴＤＩ／２，６−ＴＤＩ＝８０／２０（質量比）
コロネートＴ−６５：２，４−ＴＤＩと２，６−ＴＤＩの混合物
２，４−ＴＤＩ／２，６−ＴＤＩ＝６５／３５（質量比）
※ミリオネート、コロネートは登録商標
１，３−ＢＤ ：１，３−ブタンジオール
ＴＭＰ ：トリメチロールプロパン
Ｇｌｙ ：グリセリン
ＳＥ−１ ：トリス−（トリメチルシリル）ホスフェート
ＳＥ−２ ：トリス−（トリフェニルシリル）ホスフェート
ＳＥ−３ ：モノ−（トリメチルシリル）ホスファイト
ＥＨＡＰ ：２−エチルヘキシルアシッドホスフェート
※モノエステルとジエステル混合物
【００３９】
表１、２から、リン酸シリルエステルや亜リン酸シリルエステルを用いた本発明のポリイソシアネート溶液は、高温貯蔵においてもさほど溶剤希釈性が低下することはなく、また着色も小さいものであった。一方、シリルエステルや安定化剤を用いなかったものは、溶剤希釈性が大幅に低下し、また従来の安定化剤を用いたものは、着色が大きくなった。
【００４０】
［接着剤評価］
実施例７〜９、比較例５〜７
実施例２〜４、比較例１〜３で得られたＰ−２〜４、６〜８を硬化剤として、二液タイプの接着剤の評価を行った。主剤には接着剤用ポリウレタン樹脂溶液であるニッポラン３０１６（酢酸エチル溶液、水酸基含有量＝０．０４ｍｍｏｌ／ｇ、日本ポリウレタン工業製、固形分＝２２％）を用いた。主剤と硬化剤の配合比は、固形分換算で、主剤／硬化剤＝１０／１（質量比）となる比率とした。
【００４１】
長さ１００ｍｍ、幅２５ｍｍ、厚さ１ｍｍのポリウレタンＲＩＭ（リアクティブインジェクションモールディング）成形品、ＦＲＰ、ＡＢＳ、ボンデ鋼板をトリクロロエチレンで脱脂し、その上に上記主剤／硬化剤を配合した接着剤を乾燥膜厚：４０〜５０μ、塗布面積：２５ｍｍ×２５ｍｍになるように塗布した。そして、５０℃で５分間予備乾燥して、接着剤中の溶剤を蒸発させ、気泡がはいらないようにして同一種類の上記の各板を重ねあわせ、２．５Ｐａで圧着し、これを２０℃、６５％ＲＨの雰囲気で１週間放置し、接着サンプルを得た。その後、引張速度＝１００ｍｍ／ｍｉｎ、測定雰囲気＝２３℃×５０％ＲＨの条件で、接着剪断強度を測定した。結果を表３、４に示す。
【００４２】
【表３】

【００４３】
【表４】

【００４４】
実施例１２〜１４、比較例９〜１１
硬化剤を５０℃で３０日の雰囲気下に放置したものを使用する以外は、前述の実施例、比較例と同様にして接着性を評価した。結果を表５、６に示す。
【００４５】
【表５】

【００４６】
【表６】

【００４７】
表３〜６に示されるように、実施例において硬化剤として本発明のポリイソシアネート溶液を用いた接着剤は、比較例のものより接着強度が優れていた。これは、ポリイソシアネート溶液中に存在するリン酸シリルエステルや亜リン酸シリルエステルが接着性向上に効果があると考えられる。また、硬化剤に熱履歴を加えても、実施例では、接着力の低下が小さいものであった。
【００４８】
［塗料評価］
実施例１７〜１９、比較例１３〜１５
表７、８に示す配合で、各塗料原料を配合・混練して、塗料を調製した。配合した塗料を、あらかじめトリクロロエチレンで脱脂した鋼板（ＪＩＳ Ｇ３１４１〈３１４１−ＳＢ〉、仕様：ＰＦ−１０７７、日本テストパネル工業製、以下、ボンデ鋼板と略称する。）に塗布し、２０℃×６５％ＲＨの環境下で１週間放置して、乾燥膜厚＝４０〜５０μの塗膜を形成させた。そして、形成した塗膜の物性をＪＩＳ Ｋ５４００の処方に従って測定した。結果を表７、８に示す。
【００４９】
【表７】

【００５０】
【表８】

【００５１】
実施例２２〜２４、比較例１７〜１９
硬化剤を５０℃で３０日の雰囲気下に放置したものを使用する以外は、前述の実施例、比較例と同様にして塗膜物性を評価した。結果を表９、１０に示す。
【００５２】
【表９】

【００５３】
【表１０】

【００５４】
表７〜１０において
ヒタロイド３０８８：アクリルポリオール
日立化成工業製
水酸基価＝５０ｍｇＫＯＨ／ｇ
固形分＝５０％
ニッポラン８００ ：ポリエステルポリオール
日本ポリウレタン工業製
水酸基価＝２９０ｍｇＫＯＨ／ｇ
固形分＝１００％
ニッポラン１１００：ポリエステルポリオール
日本ポリウレタン工業製
水酸基価＝２１３ｍｇＫＯＨ／ｇ
固形分＝１００％
※ヒタロイド、ニッポランは登録商標
【００５５】
表７〜１０からに示されるように、実施例において硬化剤として本発明のポリイソシアネート溶液を用いた塗料は、比較例のものより特に密着性が優れていた。これは、ポリイソシアネート溶液中に存在するリン酸シリルエステルや亜リン酸シリルエステルが密着性向上に効果があると考えられる。また、硬化剤に熱履歴を加えても、実施例のものは密着性の低下が小さいものであった。[0001]
BACKGROUND OF THE INVENTION
The present invention is characterized in that, in the curing agent to be blended with the main component which is a polyvalent hydroxyl compound, it comprises a polyisocyanate solution comprising an isocyanate group-terminated prepolymer, a silyl phosphate ester and / or a silyl phosphite ester, and an organic solvent. The two-component curable polyisocyanate curing agent, and the adhesive and paint using the same.
[0002]
[Prior art]
Polyisocyanate solutions are easy to handle because of their low viscosity, and because the reactivity of isocyanate groups is very high, the time required for reaction (curing, crosslinking, etc.) can be shortened, so in the field of adhesives and paints Widely used.
[0003]
However, problems with storage stability often arise due to the high reactivity of isocyanate groups. Therefore, various attempts have been made to improve this point. For example, in Japanese Patent Application Laid-Open No. 59-98050, in order to improve the stability of organic polyisocyanate against coloring by air, light, heat, etc., organic phosphites such as didecylpentaerythritol diphosphite and 2 , 6-ditertiarybutyl-4-methylphenol and 2 (2'-hydroxy-3 ', 5' ditertiaryamylphenyl) benzotriazole are added in combination with organic polyisocyanate to improve stability I am trying. In addition, in JP-A-5-117220, in obtaining isocyanurate-modified polyisocyanate, stability is improved by adding a silylated ester of a specific strong organic acid before (thin film) distillation. .
[0004]
[Problems to be solved by the invention]
In the present invention, it has been found that silyl phosphate and / or phosphite silyl ester is effective not only for improving storage stability but also for improving adhesiveness and adhesion, and thus completing the present invention. It was.
[0005]
[Means for Solving the Problems]
That is, this invention is shown by the following (1)-(3).
[0006]
(1) An isocyanate group-terminated urethane prepolymer obtained by reacting an organic polyisocyanate (A1) with a low molecular polyol (A2) having a molecular weight of 76 or more and less than 500 in a curing agent to be blended with a main component which is a polyvalent hydroxyl compound ( A two-component curable polyisocyanate curing agent comprising A), a phosphoric acid silyl ester and / or a phosphorous acid silyl ester (B), and an organic solvent (C).
[0007]
(2) An adhesive comprising the two-component curable polyisocyanate curing agent of (1).
[0008]
(3) A paint comprising the two-component curable polyisocyanate curing agent of (1).
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the components of the present invention will be described.
The isocyanate group-terminated urethane prepolymer (A) in the two-component curable polyisocyanate curing agent of the present invention is obtained by urethanizing an organic polyisocyanate (A1) and a polyol (A2) in an isocyanate group-excess atmosphere. Is.
[0010]
Examples of the organic polyisocyanate (A1) used in the present invention include compounds having two or more isocyanate groups in one molecule, such as toluene diisocyanate (hereinafter abbreviated as TDI), diphenylmethane diisocyanate (hereinafter abbreviated as MDI), A mixture of MDI and MDI-based polynuclear condensate (hereinafter abbreviated as polymeric MDI), xylene diisocyanate, diphenyl ether diisocyanate, dimethyldiphenylmethane diisocyanate, phenylene diisocyanate, naphthalene diisocyanate, tetramethylxylene diisocyanate, and the like, tetramethylene diisocyanate, Hexamethylene diisocyanate (hereinafter abbreviated as HDI), 3-methyl-1,5-pentane diisocyanate, Aliphatic diisocyanates such as emissions diisocyanate, isophorone diisocyanate, hydrogenated toluene diisocyanate, hydrogenated xylene diisocyanate, hydrogenated diphenylmethane diisocyanate, also alicyclic diisocyanates such as hydrogenated tetramethylxylylene diisocyanate can be used. In addition, modified products such as biuret, allophanate, isocyanurate (trimer), uretdione (dimer), carbodiimide, uretonimine, etc. modified with a part of these isocyanate groups, and those modified with oxazolidone, amide, imide, etc. Can be used. These can be used alone or as a mixture of two or more.
[0011]
Among the organic polyisocyanates, TDI is preferable, and among them, TDI composed of 100 to 50% by weight of 2,4-TDI and 0 to 50% by weight of 2,6-TDI is particularly preferable.
[0012]
The low molecular polyol (A2) used in the present invention has a molecular weight of 76 or more and less than 500, and has 2 or more, preferably 2 to 3 alcoholic hydroxyl groups in one molecule.
[0013]
Low molecular polyols include ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propanediol, 1,3-propanediol, dipropylene glycol, 1,2-butanediol, 1,3-butanediol, 1,4 -Butanediol, 1,6-hexanediol, neopentyl glycol, 3-methyl-1,5-pentanediol, cyclohexane-1,4-diol, cyclohexane-1,4-dimethanol, hydrogenated bisphenol A, glycerin, Examples include trimethylolpropane, pentaerythritol, sorbitol, sucrose, diglycerin and the like.
[0014]
[0015]
In the reaction of the organic polyisocyanate (A1) and the polyol (A2), the equivalent ratio of the isocyanate group to the hydroxyl group (isocyanate group / hydroxyl group) is preferably 1.5 to 500, and more preferably 2 to 400. The reaction temperature of the urethanization reaction is preferably 30 to 120 ° C, particularly preferably 50 to 100 ° C. In the urethanization reaction, a known urethanization catalyst such as a tertiary amine catalyst or a metal catalyst can be used.
[0016]
Specific examples of the tertiary amine catalyst include triethylamine, triethylenediamine, N-methylmorpholine, N-methylimidazole, 1-methylimidazole, 1-ethylimidazole, 1-propylimidazole, 1-cyanoimidazole, 1-cyanomethylimidazole. 1,2-dimethylimidazole, 1,4-dimethylimidazole, 1-methyl-2-ethylimidazole, 1-methyl-4-ethylimidazole, 1-ethyl-2-methylimidazole, 1-ethyl-4-methylimidazole , Pyridine, α-picoline and the like.
[0017]
Examples of the amine-based catalyst having active hydrogen that reacts with the polyisocyanate composition include monoethanolamine, diethanolamine, triethanolamine, N, N, N'-trimethylaminoethylethanolamine, N, N, N ', N '-Tetramethylhydroxypropylenediamine and the like can be mentioned.
[0018]
Specific examples of the metal catalyst include dibutyltin dilaurate, dioctyltin dilaurate, calcium naphthenate, potassium octylate, tin octylate, and zinc octylate.
[0019]
The phosphoric acid silyl ester and / or phosphorous acid silyl ester (B) used in the present invention has a molecular structure in which the acidic hydrogen atom of phosphoric acid or phosphorous acid is substituted with a silyl group represented by the following formula. is there.
[Chemical 1]

[0020]
(B) has three types of monoesters, diesters and triesters: mono- (trimethylsilyl) phosphate, di- (trimethylsilyl) phosphate, tris- (trimethylsilyl) phosphate, mono- (triethylsilyl) phosphate, di- (Triethylsilyl) phosphate, tris- (triethylsilyl) phosphate, mono- (tributylsilyl) phosphate, di- (tributylsilyl) phosphate, tris- (tributylsilyl) phosphate, mono- (triphenylsilyl) phosphate, di- ( Triphenylsilyl) phosphate, tris- (triphenylsilyl) phosphate, trimethylsilyl phosphate, triethylsilyl phosphate, tributylsilyl phosphate, mono- (2-ethylhexyl) Silyl) phosphate, di- (2-ethylhexylsilyl) phosphate, tris- (2-ethylhexylsilyl) phosphate, mono- (trimethylsilyl) phosphite, di- (trimethylsilyl) phosphite, tris- (trimethylsilyl) phosphite, mono- (Triethylsilyl) phosphite, di- (triethylsilyl) phosphite, tris- (triethylsilyl) phosphite, mono- (tributylsilyl) phosphite, di- (tributylsilyl) phosphite, tris- (tributylsilyl) phos Phyto, mono- (triphenylsilyl) phosphite, di- (triphenylsilyl) phosphite, tris- (triphenylsilyl) phosphite, monomethylsilyl phosphite, dimethylsilyl phosphite, Methyl silyl phosphite, and the like. In the present invention, phosphorous acid monoester type and phosphoric acid triester type are preferable.
[0021]
The amount of (B) added is preferably 0.0001 to 5.0% by mass, particularly preferably 0.0001 to 1% by mass, based on the isocyanate group-terminated urethane prepolymer (A). Moreover, about the addition time of (B), although before and after reaction of organic polyisocyanate (A1) and polyol (A2) is not ask | required, after reaction is preferable.
[0022]
The effect of (B) is to improve the storage stability by suppressing the reaction with active hydrogen compounds such as moisture during the storage period of the polyisocyanate solution.
[0023]
The organic solvent (C) used in the present invention is a solvent inert to isocyanate groups, which is commonly used in the polyurethane industry. For example, aromatic solvents such as toluene and xylene, acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone. Such as ketone solvents, ester solvents such as ethyl acetate, butyl acetate, isobutyl acetate, ethylene glycol ethyl ether acetate, propylene glycol methyl ether acetate, 3-methyl-3-methoxybutyl acetate, ethyl-3-ethoxypropionate And glycol ether ester solvents such as tetrahydrofuran and dioxane. These can be used alone or in combination.
[0024]
As for solid content of the polyisocyanate solution in this invention, 10-90 mass% is preferable, Most preferably, it is 20-80 mass%. The isocyanate content is preferably 1 to 30% by mass, particularly preferably 2 to 25% by mass in the solution state.
[0025]
The adhesive and paint of the present invention are characterized by using the above-mentioned polyisocyanate solution as a two-component curing type curing agent. Adhesives and paints are roughly classified into one-pack type and two-pack type. The one-component type is a type in which the isocyanate group in the polyisocyanate solution is further blocked with a blocking agent as a latent curing agent, and is used in combination with a polyhydric hydroxyl compound as a main component in advance and moisture-cured alone. There are types. In the two-pack type, the polyisocyanate solution described above is used as a curing agent, and the polyhydric hydroxyl compound as a main component is blended and used immediately before use. In the present invention, a two-pack type in which a polyvalent hydroxyl compound as a main ingredient is blended and used is preferable.
[0026]
In the two-component type paint or adhesive using the polyisocyanate solution used in the present invention as a two-component curing type curing agent, the polyvalent hydroxyl compound used as the main agent is not only the polyol (A2) but also a molecule. A compound having a number average molecular weight of 500 to 100,000 having two or more hydroxyl groups therein is preferred. Specifically, saturated or unsaturated polyester polyol, polycaprolactone polyol, saturated or unsaturated oil-modified or fatty acid-modified alkyd polyol, amino alkyd polyol, polycarbonate polyol, acrylic polyol, polyether polyol, epoxy polyol, fluorine-containing polyol, Furthermore, saturated or unsaturated polyester resin, polycaprolactone resin, saturated or unsaturated oil-modified or fatty acid-modified alkyd resin, amino alkyd resin, polycarbonate resin, acrylic resin, polyether resin, epoxy resin, polyurethane resin, cellulose acetate butyrate Examples thereof include resins and fluorine-containing resins.
[0027]
In the adhesive and paint of the present invention, the molar ratio of the (latent) isocyanate group in the polyisocyanate composition to the hydroxyl group in the polyvalent hydroxyl compound is 9: 1 to 1: 9, preferably 7: 3 to 3. : It is the range of 7. The composition of the present invention may contain various pigments and additives commonly used in the lacquer industry in addition to the solvent described below. Furthermore, the composition of the present invention can be applied by a conventional coating method conventionally used. For coating, an airless spray machine, an air spray machine, an electrostatic coating machine, dipping, a roll coater, a knife coater, a brush. Etc. can be used.
[0028]
In the present invention, if necessary, the above-mentioned urethanization catalyst can be further blended and used. The addition amount of the catalyst is preferably 0.01 to 20% by mass with respect to the isocyanate group-terminated urethane prepolymer. When the addition amount is less than the lower limit, the curing reaction is insufficient and the intended physical properties cannot be obtained.
[0029]
Further, the adhesive and paint of the present invention include inorganic fillers such as cement, blast furnace slag, gypsum, calcium carbonate, clay, aluminum hydroxide, antimony trioxide, quicklime, slaked lime, bentonite, leveling agents, flame retardants. Antiaging agents, heat resistance imparting agents, antioxidants, and the like can be blended by appropriately adjusting the blending amounts.
[0030]
【The invention's effect】
Since the polyisocyanate solution used in the two-component curable polyisocyanate curing agent of the present invention has little change over time due to the reaction of isocyanate groups, there is little deterioration such as an increase in the number of colors and viscosity, leading to an improvement in storage stability. Further, as will be described later, since it is effective in improving adhesiveness and adhesion, an adhesive and paint having good performance can be obtained.
[0031]
【Example】
Next, the polyisocyanate composition of the present invention and the adhesive and paint using the same will be described in more detail based on examples, but the present invention is not limited to such examples.
[0032]
[Synthesis of Polyisocyanate Composition]
Example 2
A reactor with a capacity of 1,000 ml, equipped with a stirrer, thermometer, reflux condenser and nitrogen gas inlet tube, 100 g of Coronate T-80, 3 g of 1,3-BD, 5 g of TMP, 2 g of Gly The mixture was heated to 70 to 80 ° C. while charging and stirring, and the urethanization reaction was advanced until the target NCO content was reached. Thereafter, it was diluted with a silyl ester and an organic solvent to synthesize a polyisocyanate solution P-1. The synthesis results are shown in Table 1.
[0033]
Examples 3-4, Comparative Examples 1-3
Predetermined amounts of isocyanate and polyol were charged into a 300 ml reactor equipped with a stirrer, thermometer, reflux condenser and nitrogen gas inlet tube. This was heated to 70-80 ° C. with stirring, and the urethanization reaction was advanced until the target NCO content was reached. And then, unreacted TDI (or HDI) in this reaction solution is removed by thin-film distillation at 120 to 140 ° C. and 1 to 5 Pa so that the residual free diisocyanate content is 0.5% by mass or less, Thereafter, it was diluted with a silyl ester or a stabilizer and an organic solvent to synthesize polyisocyanate solutions P-3, 4 , 6-8 . The synthesis results are shown in Tables 1 and 2.
[0034]
[Solvent dilution test method]
Since polyisocyanate generally has an isocyanate group at the terminal, it becomes high molecular weight due to reaction with moisture during the storage period, and the solubility in a solvent decreases. Then, it determined using the solvent dilution property test described below as one index of storage stability.
[0035]
5 g of the polyisocyanate solution was sampled, toluene was added little by little with a burette, and the mixture was thoroughly shaken to make the cloudy point the end point, and the required number of ml of solvent at that time was determined. And the solvent dilution property (times) was calculated | required by the following formula. The larger this value, the better the solvent dilutability. The results are shown in Table 1.
Solvent dilution (times) = required number of ml of solvent / sample amount (5g)
[0036]
[Table 1]

[0037]
[Table 2]

[0038]
In Tables 1 and 2, Millionate MTL: MDI Carbodiimide Modified Polyisocyanate
Made by Nippon Polyurethane Industry
Isocyanate content = 29.0%
Solid content = 100%
Coronate T-80: Mixture of 2,4-TDI and 2,6-TDI
2,4-TDI / 2,6-TDI = 80/20 (mass ratio)
Coronate T-65: Mixture of 2,4-TDI and 2,6-TDI
2,4-TDI / 2,6-TDI = 65/35 (mass ratio)
* Millionate and coronate are registered trademarks 1,3-BD: 1,3-butanediol TMP: trimethylolpropane Gly: glycerin SE-1: tris- (trimethylsilyl) phosphate SE-2: tris- (triphenylsilyl) phosphate SE -3: mono- (trimethylsilyl) phosphite EHAP: 2-ethylhexyl acid phosphate * monoester and diester mixture
From Tables 1 and 2, the polyisocyanate solution of the present invention using phosphoric acid silyl ester or phosphorous acid silyl ester was not significantly reduced in solvent dilution even during high-temperature storage, and the coloration was small. . On the other hand, those that did not use silyl esters and stabilizers had greatly reduced solvent dilutability, and those that used conventional stabilizers were more colored.
[0040]
[Adhesive evaluation]
Examples 7-9, Comparative Examples 5-7
Two-component adhesives were evaluated using P- 2 to 4 and 6 to 8 obtained in Examples 2 to 4 and Comparative Examples 1 to 3 as curing agents. NIPPOLAN 3016 (ethyl acetate solution, hydroxyl group content = 0.04 mmol / g, manufactured by Nippon Polyurethane Industry, solid content = 22%), which is a polyurethane resin solution for adhesives, was used as the main agent. The mixing ratio of the main agent and the curing agent was set to a ratio of main agent / curing agent = 10/1 (mass ratio) in terms of solid content.
[0041]
100 mm long, 25 mm wide, 1 mm thick polyurethane RIM (reactive injection molding) molded product, FRP, ABS, bonded steel sheet are degreased with trichlorethylene, and then the adhesive containing the above main agent / curing agent is dried on the film It applied so that it might become thickness: 40-50micro and application | coating area: 25 mm x 25 mm. Then, it is pre-dried at 50 ° C. for 5 minutes to evaporate the solvent in the adhesive, and the above-mentioned plates of the same type are stacked so as not to enter bubbles, and pressure-bonded at 2.5 Pa. And left in a 65% RH atmosphere for 1 week to obtain an adhesive sample. Thereafter, the adhesive shear strength was measured under the conditions of tensile rate = 100 mm / min and measurement atmosphere = 23 ° C. × 50% RH. The results are shown in Tables 3 and 4.
[0042]
[Table 3]

[0043]
[Table 4]

[0044]
Examples 12-14, Comparative Examples 9-11
Adhesiveness was evaluated in the same manner as in the above-described Examples and Comparative Examples, except that a curing agent was used that was left in an atmosphere at 50 ° C. for 30 days. The results are shown in Tables 5 and 6.
[0045]
[Table 5]

[0046]
[Table 6]

[0047]
As shown in Tables 3 to 6, the adhesives using the polyisocyanate solution of the present invention as the curing agent in the examples were superior in adhesive strength to those of the comparative examples. This is considered that the silyl phosphate ester and the silyl phosphite ester present in the polyisocyanate solution are effective in improving adhesion. Moreover, even if a heat history was added to the curing agent, in the examples, the decrease in adhesive force was small.
[0048]
[Paint evaluation]
Examples 17-19, Comparative Examples 13-15
In the formulations shown in Tables 7 and 8, each paint raw material was blended and kneaded to prepare a paint. The blended paint is applied to a steel plate (JIS G3141 <3141-SB>, specification: PF-1077, manufactured by Nippon Test Panel Industry, hereinafter abbreviated as a bonde steel plate) degreased in advance with trichlorethylene, and 20 ° C. × 65%. A coating film having a dry film thickness of 40 to 50 μm was formed by allowing to stand in an environment of RH for one week. And the physical property of the formed coating film was measured according to prescription of JIS K5400. The results are shown in Tables 7 and 8.
[0049]
[Table 7]

[0050]
[Table 8]

[0051]
Examples 22-24, Comparative Examples 17-19
The physical properties of the coating film were evaluated in the same manner as in the Examples and Comparative Examples described above, except that a curing agent was used that was left in an atmosphere at 50 ° C. for 30 days. The results are shown in Tables 9 and 10.
[0052]
[Table 9]

[0053]
[Table 10]

[0054]
In Tables 7-10, Hitaroid 3088: Acrylic polyol
Made by Hitachi Chemical
Hydroxyl value = 50 mgKOH / g
Solid content = 50%
Nippon Runan 800: Polyester polyol
Made by Nippon Polyurethane Industry
Hydroxyl value = 290 mgKOH / g
Solid content = 100%
Nippon Run 1100: Polyester polyol
Made by Nippon Polyurethane Industry
Hydroxyl value = 213 mgKOH / g
Solid content = 100%
* Hitaroid and Nipponran are registered trademarks [0055]
As shown in Tables 7 to 10, the paints using the polyisocyanate solution of the present invention as the curing agent in the examples were particularly superior in adhesion to those of the comparative examples. This is considered that the silyl phosphate ester and the silyl phosphite ester present in the polyisocyanate solution are effective in improving adhesion. Moreover, even if it added the heat history to the hardening | curing agent, the thing of an Example had a small fall of adhesiveness.

Claims (3)

In the curing agent to be blended with the main component which is a polyvalent hydroxyl compound,
Isocyanate group-terminated urethane prepolymer (A), phosphoric acid silyl ester and / or phosphorous acid silyl ester (B) obtained by reacting organic polyisocyanate (A1) with low molecular weight polyol (A2) having a molecular weight of 76 or more and less than 500 ), An organic solvent (C), and a two-component curable polyisocyanate curing agent.   An adhesive comprising the two-component curable polyisocyanate curing agent according to claim 1.   A paint comprising the two-component curable polyisocyanate curing agent according to claim 1.