JP3911489B2 - Surface treatment agent for rubber composition - Google Patents

Description

【００１０】
したがって、押出し成形機において前記のような硬化剤を含んだ表面処理剤を用いた場合、その表面処理剤は生産時間経過と共に押出し口金にて硬化および口金内部に付着し、詰まりを発生させるため、それ以降の連続性生産が困難になる。
【００１１】
すなわち、前記のように表面処理剤において意図しない硬化反応が起こり、ゴム組成物の製造機器にて異物（表面処理剤の硬化物）が形成された場合には、例えば生産ラインを停止して前記製造機器に形成された異物の除去や清掃を行う必要があるため、ゴム組成物の生産性（連続生産可能時間）が低減してしまう。このような現象は、押出し口金の温度が上昇するに連れて顕著になる。
【００１２】
なお、前記の押出し口金の温度を低く設定した場合、前記の表面処理剤の硬化反応時間が延長され連続生産可能時間を長くすることができるが、ゴム組成物自体の押出し成形性が低減してしまう。また、連続生産可能時間については下記表２に示す。
【００１３】
【表２】

【００１４】
本発明は前記課題に基づいてなされたものであり、表面処理剤の硬化剤を所定のブロック比率でマスキングして硬化反応速度を制御することにより、優れた表面処理剤の性能（摺動性，伸び性，磨耗耐久性，非粘着性）を確保すると共に、生産性を維持することが可能な高分子材料組成物の表面処理剤を提供することにある。
【００１５】
【課題を解決するための手段】
本発明は、前記課題の解決を図るために、請求項１記載の発明はイソシアネート基を有する硬化剤と、該硬化剤と反応させるポリオールを有する主剤と、から成り、ゴム押出し加硫成形における押出し成形時（例えば、段落［０００８］に示すように口金に８０〜１２０℃程度の高温が掛かる押出し成形時）に塗布され、該押出し成形品の表面に摺動性を付与できる表面処理剤（例えば、グラスラン等のゴム組成物の摺動抵抗を低減するための表面処理剤であって、そのゴム組成物の押出し成形時に塗布されるもの）において、前記イソシアネート基が解離温度１３０℃〜１６０℃のブロック剤によりブロック率１０％〜６０％の範囲内で部分マスキングされ、該ブロック比率に応じて前記の押出し成形時の硬化反応速度が抑制されたことを特徴とする
【００１６】
請求項２記載の発明は、前記請求項１記載の発明において、前記部分マスキングのブロック率は１０％〜４０％の範囲内であることを特徴とする。
【００１７】
請求項３記載の発明は、前記請求項１または２記載の発明において、前記ブロック剤はオキシムから成ることを特徴とする。
【００１８】
本発明における表面処理剤の主剤には、例えば分子中に少なくとも１個以上の水酸基を有するポリオール成分，摺動抵抗を低減するための成分（例えば、フッ素，ナイロン等のパウダーや、シリコーンオイル等の滑性オイル）を含有したものが適用される。
【００１９】
前記のイソシアネート基を有する硬化剤には、例えばトリレンジイソシアネート，ジフェニルメタンジイソシアネート，ヘキサメチレンジイソシアネート等のポリイソシアネートや、それらポリイソシアネート２種類以上を混合したものが適用される。
【００２０】
前記の解離温度１３０℃〜１６０℃のブロック剤の替わりに、例えば解離温度が１３０℃未満のもの（アセチルアセトン，アセト酢酸エチル等）を適用した場合には、部分マスキングのブロック率を大きくすることにより表面処理剤の硬化反応速度を本発明と同様に抑制できるが、そのブロック率の上昇に伴って表面処理剤の粘度は大きく（粘度２０Ｐａ・ｓ超）なり、表面処理剤の塗布性が低下してしまう。たとえ表面処理剤の粘度が大きくならないように前記のブロック率を設定しても、その粘度上昇の防止と硬化反応速度の抑制とを両立できるブロック率の範囲は極めて狭いため、表面処理剤の硬化剤としては取り扱い性の低いものとなる。
【００２１】
さらに、例えば解離温度が１８０℃超のもの（メタノール，ｎ−ペンタノール等）を適用した場合、前記のブロック率を大きくしなくとも本発明と同様に硬化反応速度の抑制および表面処理剤の粘度を低くすることができ、その表面処理剤を例えば高分子材料組成物の押出し成形時に用いても（押出し成形すると同時に該押出し成形物に塗布しても）不具合は生じないが、一般的な加硫工程（例えば、２００℃〜２２０℃程度の加硫工程）では被加硫物表面（すなわち、表面処理剤）の温度分布において１８０℃程度の部分が存在し易すいため、その表面処理剤の硬化不良を起こす恐れがある。
【００２２】
一方、本発明のように解離温度１３０℃〜１６０℃のブロック剤を用いることにより、その表面処理剤を高分子材料組成物の押出し成形時に用いることができると共に、その表面処理剤を一般的な加硫工程にて確実に硬化させることができる。
【００２３】
【発明の実施の形態】
以下、本発明の実施の形態における高分子材料組成物の表面処理剤を図面等に基づいて詳細に説明する。
【００２４】
本実施の形態では、イソシアネート基を有する硬化剤を含み高分子材料組成物の摺動性を付与するための表面処理剤において、解離温度が１３０℃〜１６０℃のブロック剤（オキシム）を用いて前記硬化剤のイソシアネート基をマスキングする。また、前記のマスキングにおいては、前記表面処理剤の硬化反応速度を制御するため、単に全てのイソシアネート基に対して行うのではなく、高分子材料組成物の製造条件等（例えば、押出し口金の温度等）に応じてイソシアネート基に対するブロック比率を調整（例えば、後述する実施例では１０％〜４０％の範囲内に設定）して行う。
【００２５】
本実施の形態のように、解離温度が１３０℃〜１６０℃のブロック剤を用い、硬化剤のイソシアネート基の一部のみをマスキング（以下、部分マスキングと称する）して表面処理剤の硬化反応速度を制御（抑制）することにより、高分子材料組成物の製造工程（例えば、押出し成形工程）において表面処理剤の意図しない硬化反応を防止（生産性の向上）し、前記表面処理剤の塗布性（塗布し易さ）を確保できると共に該表面処理剤の硬化を所定温度の熱により確実に行う（部分マスキングを解離（ブロック剤の揮発）し硬化不良を防止する）ことが可能となる。
【００２６】
例えば、ゴム基材を押出し成形すると共に該押出し成形物に対して本実施の形態の表面処理剤を塗布した場合には、その表面処理剤は押出し口金の熱では硬化せず、ゴム組成物を加硫する際（加硫工程）の熱によって確実に硬化される。このため、そのゴム組成物において良好な摺動性が得られる（および伸び性，磨耗耐久性，非粘着性の良好な塗膜を形成することが可能）と共に、生産性を維持することができる。
【００２７】
［実施例］
次に、本実施の形態に基づいて作製した表面処理剤の実施例について説明する。まず、１００重量部のポリエーテルポリオール，３０重量部のナイロンパウダー，２５重量部のシリコーンオイル，５重量部のカーボンブラックを混合して、表面処理剤の主剤を得た。
【００２８】
また、５０重量部のヘキサメチレンジイソシアネート，５０重量部のジフェニルメタンジイソシアネートを混合し、その混合物に対して解離温度が１３０℃〜１４０℃のメチルエチルケトンオキシム（２−ブタノンオキシム；Ｃ₄Ｈ₉ＮＯ）から成るブロック剤を０〜２７．２重量部加えることにより、前記混合物のイソシアネート基がブロック比率０〜７０％の範囲内で部分マスキングされた硬化剤を得た。
【００２９】
そして、前記の主剤に対して各硬化剤を加え混合することにより、下記表３に示す組成の表面処理剤の試料Ｓ１〜Ｓ８を作製した。なお、前記の各試料Ｓ１〜Ｓ８に用いた主剤および硬化剤の種類については下記表４に示す。
【００３０】
【表３】

【００３１】
【表４】

【００３２】
前記の各試料Ｓ１〜Ｓ８について、粘度（目標値；２０Ｐａ・ｓ以下），温度１００℃または１２０℃の加熱により硬化させた際の硬化反応時間（目標値；１００℃の場合は８時間以上，１２０℃の場合は４時間以上）をそれぞれ調べた。また、押出し成形機を用いた実際の高分子材料組成物の製造ラインにおいて、押出し成形物に対して前記の各試料Ｓ１〜Ｓ８を厚さ１００μｍまたは１５０μｍで塗布（押出し成形と同時に塗布）し、それら各押出し成形物を加硫させた際の各試料Ｓ１〜Ｓ８の硬化性（目標；試料の硬化が十分であること）をそれぞれ調べた。
【００３３】
さらに、前記の試料Ｓ１〜Ｓ８を高分子材料組成物に用いた場合について、それら各試料Ｓ１〜Ｓ８の伸び性，磨耗耐久性，非粘着性，摩擦係数，摺動抵抗を以下に示す方法によりそれぞれ調べた。なお、以下に示すテストピースは、試料（試料Ｓ１〜Ｓ８のうち何れか一つ）を厚さ２ｍｍのゴム板表面に塗布し、その試料を加熱により硬化させて得た平板状の部材（ゴム板表面に試料の塗膜が形成された部材）とする。
【００３４】
（伸び性）
平板状（長さ１５０ｍｍ，幅１０ｍｍ）のテストピースの一端面側の中央部に対して長さ２０ｍｍの標線を記載し、そのテストピースを引張り試験機により引張り（引張り速度；２００ｍｍ／分）、塗膜においてクラックが生じた際のテストピースの伸び率（目標値；１００％以上）を測定した。
【００３５】
（磨耗耐久性）
図１の定荷重摩擦試験機を用いた方法の概略説明図に示すように、まず、平板状（長さ８０ｍｍ，幅３ｍｍ）のテストピース１１の塗膜（試料から成る塗膜）１１ａに対しガラス板（テストピース１１の長手方向の幅が３０ｍｍのガラス板）１２を当接すると共に、そのテストピース１１の他端面に鉄板１３を当接した。そして、前記テストピース１１を固定しながら、前記鉄板１３を介して前記テストピース１１に対し９．８Ｎの荷重を加えると共に、前記ガラス板１２を図示白抜き矢印方向（テストピース１１の長手方向）に往復運動させることにより、そのガラス板１２を塗膜１１ａ表面で摺動させ、その塗膜１１ａの裂傷等によりゴム板表面が露出した際の往復運動回数を測定した（目標値；２万回以上）。
【００３６】
なお、本実施例における磨耗耐久性の測定は、前記ガラス板１２の往復運動のストローク，サイクルをそれぞれ５０ｍｍ，６０回／分とし、その往復運動を５００回行う毎に０．５ｃｃのダスト（水：ダスト＝３：１）を摺動面に付加しながら行った。
【００３７】
（非粘着性）
図２Ａ（平面図），Ｂ（側面図）の概略説明図に示すように、まず、両面テープ（両面粘着性を有するフィルム）を介して、２つの平板状（長さ５０ｍｍ，幅５ｍｍ）のテストピース２１におけるゴム板が露出した面を、鉄板２３に対して粘着固定した。また、前記の各テストピース２１の塗膜２１ａ表面を覆うようにガラス板２２を位置させ、それら各テストピース２１を所定圧力で圧縮するようにガラス板２２と鉄板２３とを市販のクリップ２６で挟持し、サンシャインウェザーメータを用い雨なし条件の雰囲気下（温度８３℃雰囲気下）に２００時間暴露した。
【００３８】
その後、前記のクリップ２６を取り外し、前記の鉄板２３を固定した状態でガラス板２２のみを図示白抜き矢印の方向に５０ｍｍ／分の速度で引張り、その際のガラス板２２と各テストピースとの剥離強度を測定した（目標値；５０Ｎ以下）。
【００３９】
（摩擦係数）
図３の概略説明図に示すように、まず、両面テープを介して、平板状（長さ１００ｍｍ，幅２０ｍｍ）のテストピース３１におけるゴム板が露出した面を鉄板３３に対して粘着固定した。また、前記のテストピース３１の塗膜３１ａ表面に対してガラス部材（半球面状のガラス３４ａを備えた部材）３４を当接（ガラス３４ａ球面を塗膜３１ａ表面に当接）させると共に、そのガラス部材３４にロードセル３５を接続した。
【００４０】
そして、前記のガラス部材３４上に重量１００ｇの錘３４ｂを載置し（すなわち、テストピース３１に対して約０．９８Ｎの荷重を加え）、そのガラス３４ａ球面が塗膜３１ａ表面で摺動（テストピース３１の長手方向に摺動）するように鉄板３３を図示白抜き矢印の方向へ移動（テストピース３１の長手方向に移動）させることにより、そのテストピース３１の静摩擦係数（「鉄板３３移動開始時の最大摩擦抵抗値」／「荷重（約０．９８Ｎ）」），動摩擦係数（「鉄板３３移動中の平均摩擦抵抗値」／「荷重（約０．９８Ｎ）」）を前記ロードセル３５により測定した（目標値；静摩擦係数の場合は１．０以下，動摩擦係数の場合は０．３以下）。
【００４１】
（摺動抵抗）
図４の概略説明図に示すように、まず、試料（試料Ｓ１〜Ｓ８のうち何れか一つ）を自動車等に用いられているグラスラン（長さ５００ｍｍ）４１表面に塗布し、その試料を加熱硬化させて塗膜（図示省略）を形成した。また、前記のグラスラン４１を固定し、そのグラスラン４１上（塗膜表面）に対してガラス板（長さ２００ｍｍ，厚さ４ｍｍのガラス板）４２を載置（グラスラン４１の長手方向とガラス板４２の長手方向とが並行になるように載置）すると共に、そのガラス板４２にロードセル４５を接続した。
【００４２】
そして、前記ガラス板４２を図示白抜き矢印方向（グラスラン４１の長手方向）に３０００ｍｍ／分で往復運動させることにより、そのガラス板４２を塗膜表面で摺動させた際の平均摩擦抵抗値を測定した（目標値；１０Ｎ以下）。
【００４３】
前記のように測定した各試料Ｓ１〜Ｓ８の特性について下記表５に示した。なお、下記表５について、硬化性の欄の記号「○」は硬化が十分であること，記号「×」は硬化不十分であることとする。また、総合評価の欄の記号「○」は高分子材料組成物の押出し成形時に用いる表面処理剤として優秀であること（高分子材料組成物の摺動性を良好にすると共に生産性を維持できること），記号「×」は不適格であることとする。
【００４４】
【表５】

【００４５】
前記の表５に示す結果から、イソシアネート基の部分マスキングのブロック比率が５０％〜７０％の硬化剤を用いた試料Ｓ６〜Ｓ８は、十分長い硬化反応時間を確保できるが、ブロック比率の増加に伴って粘度が大きくなる（すなわち、塗布性の悪化）と共に硬化性が悪化してしまうことを読み取れる。また、ブロック剤を含有しない試料Ｓ１は、硬化性，伸び性，磨耗耐久性，非粘着性に優れ、良好な粘度，摩擦係数，摺動抵抗が得られるが、硬化反応時間が短くなってしまうことを読み取れる。
【００４６】
一方、イソシアネート基の部分マスキングのブロック比率が１０％〜４０％の硬化剤を用いた試料Ｓ２〜Ｓ５は、硬化性，伸び性，磨耗耐久性，非粘着性に優れると共に、良好な粘度，硬化反応時間，摩擦係数，摺動抵抗が得られ、高分子材料組成物の押出し成形時に用いる表面処理剤として優秀であることを確認できた。
【００４８】
以上、本発明において、記載された具体例に対してのみ詳細に説明したが、本発明の技術思想の範囲内で多様な変形及び修正が可能であることは、当業者にとって明白なことであり、このような変形及び修正が特許請求の範囲に属することは当然のことである。
【００４９】
【発明の効果】
以上示したように本発明によれば、解離温度が１３０℃〜１６０℃のブロック剤によって硬化剤のイソシアネート基を部分マスキング（例えば、ブロック比率１０％〜４０％で部分マスキング）して表面処理剤の硬化反応速度を制御することにより、表面処理剤の粘度が十分に低く、且つ意図しない硬化反応を防止できる（例えば、押出し成形時の熱（押出し口金の熱）では硬化しない）ため、良好な塗布性が得られると共に生産性を維持することが可能となる。
【００５０】
また、表面処理剤が所定温度の熱（高分子材料組成物を加硫する際の熱）で確実に硬化するため、高分子材料組成物に対して伸び性，磨耗耐久性，非粘着性の良好な塗膜を形成することができると共に優れた摺動性が得られる。
【図面の簡単な説明】
【図１】本実施例における伸び性の測定方法を示す概略説明図。
【図２】本実施例における非粘着性の測定方法を示す概略説明図。
【図３】本実施例における摩擦係数の測定方法を示す概略説明図。
【図４】本実施例における摺動抵抗の測定方法を示す概略説明図。
【符号の説明】
１１，２１，３１…テストピース
１１ａ，２１ａ，３１ａ…塗膜
１２，２２，４２…ガラス板
１３，２３，３３…鉄板
３４…ガラス部材
３５，４５…ロードセル
４１…グラスラン[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a surface treatment agent for a polymer material composition (rubber composition) , for example, a surface treatment for imparting slidability of a rubber composition such as glass run or weather strip used in automobiles. It relates to the agent.
[0002]
[Prior art]
For example, a long rubber composition having substantially the same cross-sectional shape, such as a glass run or weather strip used in automobiles, is formed by extrusion molding, and a surface treatment agent is applied to the surface of the composition. There is a case. In the case of a glass run used in an automobile, a surface treatment agent for reducing sliding resistance (giving slidability) is applied to the contact surface with the window glass.
[0003]
As a method for producing a polymer material composition coated with a surface treating agent as described above in a short time, for example, as shown in JP-A-5-131519 and JP-B-7-64006, a rubber substrate is used. At the same time as extrusion molding, a surface treatment agent is applied to the surface of a predetermined portion (for example, a portion requiring slidability) in the extrusion-molded product, and then the extrusion molding is performed at a predetermined temperature (for example, 200 ° C. to 220 ° C.). There is known a method of vulcanizing an object and curing (heat curing) the surface treatment agent by heat during the vulcanization.
[0004]
[Patent Document 1]
JP-A-5-131519 (claims, paragraphs [0001], [0007]).
[0005]
[Patent Document 2]
Japanese Examined Patent Publication No. 7-64006 (Claims, page 2, left column, lines 20 to 40, FIGS. 1 to 3).
[0006]
Examples of the surface treatment agent for reducing sliding resistance include a polyol component having at least one hydroxyl group in the molecule, a component for reducing sliding resistance (for example, powder such as fluorine and nylon, And a main agent containing a lubricating oil such as silicone oil) and a curing agent for curing the surface treatment agent are generally known.
[0007]
As the curing agent, one having an isocyanate group (-NCO) is used, and for example, polyisocyanates such as tolylene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, and a mixture of two or more of these polyisocyanates are known. .
[0008]
[Problems to be solved by the invention]
When a glass run or the like is produced by an extrusion molding machine as described above, a high temperature of 80 ° C. to 120 ° C. is applied to a die (hereinafter referred to as an extrusion die) in the extrusion molding machine. The curing time at high temperature (hereinafter referred to as curing reaction time) is shown in Table 1 below.
[0009]
[Table 1]

[0010]
Therefore, when a surface treatment agent containing a curing agent as described above is used in an extrusion molding machine, the surface treatment agent is cured in the extrusion die as the production time elapses and adheres to the inside of the die, thereby causing clogging. Subsequent continuous production becomes difficult.
[0011]
That is, when an unintended curing reaction occurs in the surface treatment agent as described above and a foreign matter (cured product of the surface treatment agent) is formed in the rubber composition manufacturing equipment, the production line is stopped, for example, Since it is necessary to remove or clean the foreign matters formed on the manufacturing equipment, the productivity (time available for continuous production) of the rubber composition is reduced. Such a phenomenon becomes more prominent as the temperature of the extrusion die increases.
[0012]
In addition, when the temperature of the extrusion die is set low, the curing reaction time of the surface treatment agent can be extended and the continuous production time can be increased, but the extrusion moldability of the rubber composition itself is reduced. End up. The continuous production time is shown in Table 2 below.
[0013]
[Table 2]

[0014]
The present invention has been made based on the above problems, and by controlling the curing reaction rate by masking the curing agent of the surface treatment agent at a predetermined block ratio, excellent performance of the surface treatment agent (slidability, It is an object of the present invention to provide a surface treatment agent for a polymer material composition capable of ensuring (extensibility, wear durability, non-adhesiveness) and maintaining productivity.
[0015]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, the present invention comprises a curing agent having an isocyanate group and a main component having a polyol to be reacted with the curing agent, and the extrusion in rubber extrusion vulcanization molding. A surface treatment agent that is applied at the time of molding (for example, at the time of extrusion molding in which a high temperature of about 80 to 120 ° C. is applied to the die as shown in paragraph [0008]) and can impart slidability to the surface of the extruded molded product (for example, , a surface treatment agent for reducing the sliding resistance of the rubber composition such as glass run, in what) applied at the time of extrusion of the rubber composition, the isocyanate groups of the dissociation temperature 130 ° C. to 160 ° C. the blocking agent is partially masked within the block of 10% to 60%, the curing reaction rate at the time of extrusion of the in accordance with the block ratio is suppressed And Features [0016]
According to a second aspect of the present invention, in the first aspect of the present invention, the block ratio of the partial masking is in the range of 10% to 40%.
[0017]
A third aspect of the invention is characterized in that, in the first or second aspect of the invention, the blocking agent comprises oxime .
[0018]
The main component of the surface treatment agent in the present invention includes, for example, a polyol component having at least one hydroxyl group in the molecule, a component for reducing sliding resistance (for example, powder such as fluorine and nylon, silicone oil, etc. Those containing lubricating oil) are applied.
[0019]
Examples of the curing agent having an isocyanate group include polyisocyanates such as tolylene diisocyanate, diphenylmethane diisocyanate, and hexamethylene diisocyanate, and a mixture of two or more of these polyisocyanates.
[0020]
Instead of the blocking agent having a dissociation temperature of 130 ° C. to 160 ° C., for example, when a dissociation temperature of less than 130 ° C. (acetylacetone, ethyl acetoacetate, etc.) is applied, the block ratio of partial masking is increased. Although the curing reaction rate of the surface treatment agent can be suppressed in the same manner as in the present invention, the viscosity of the surface treatment agent increases (viscosity exceeds 20 Pa · s) as the block ratio increases, and the coating property of the surface treatment agent decreases. End up. Even if the block ratio is set so that the viscosity of the surface treatment agent does not increase, the range of the block ratio that can both prevent the increase in viscosity and suppress the curing reaction rate is extremely narrow. As an agent, the handleability is low.
[0021]
Further, for example, when a dissociation temperature exceeding 180 ° C. (methanol, n-pentanol, etc.) is applied, the curing reaction rate can be suppressed and the viscosity of the surface treatment agent can be reduced as in the present invention without increasing the block ratio. Even if the surface treatment agent is used, for example, at the time of extrusion molding of the polymer material composition (even if it is applied to the extrusion molding at the same time as the extrusion molding), no problem occurs. In the vulcanization process (for example, a vulcanization process of about 200 ° C. to 220 ° C.), it is easy to have a portion of about 180 ° C. in the temperature distribution on the surface of the vulcanized material (ie, the surface treatment agent). There is a risk of poor curing.
[0022]
On the other hand, by using a blocking agent having a dissociation temperature of 130 ° C. to 160 ° C. as in the present invention, the surface treatment agent can be used at the time of extrusion molding of the polymer material composition, and the surface treatment agent can be used in general. It can be reliably cured in the vulcanization process.
[0023]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the surface treatment agent of the polymer material composition in the embodiment of the present invention will be described in detail with reference to the drawings.
[0024]
In the present embodiment, in the surface treatment agent including a curing agent having an isocyanate group and imparting slidability of the polymer material composition, a blocking agent (oxime) having a dissociation temperature of 130 ° C. to 160 ° C. is used. Mask the isocyanate groups of the curing agent. Further, in the masking, in order to control the curing reaction rate of the surface treatment agent, it is not simply performed for all isocyanate groups, but the production conditions of the polymer material composition (for example, the temperature of the extrusion die) Etc.) is carried out by adjusting the block ratio with respect to the isocyanate group (for example, in the examples described later, within the range of 10% to 40%).
[0025]
As in this embodiment, using a blocking agent having a dissociation temperature of 130 ° C. to 160 ° C., masking only a part of the isocyanate group of the curing agent (hereinafter referred to as partial masking), the curing reaction rate of the surface treatment agent Is controlled (suppressed) to prevent an unintended curing reaction of the surface treatment agent in the production process (for example, extrusion molding process) of the polymer material composition (improving productivity), and the coating property of the surface treatment agent (Easy to apply) can be ensured and the surface treatment agent can be reliably cured by heat at a predetermined temperature (partial masking is dissociated (blocking agent is volatilized) to prevent poor curing).
[0026]
For example, when a rubber substrate is extruded and the surface treatment agent of the present embodiment is applied to the extruded product, the surface treatment agent is not cured by the heat of the extrusion die, and the rubber composition is It is reliably cured by the heat during vulcanization (vulcanization process). For this reason, good slidability can be obtained in the rubber composition (and it is possible to form a coating film having good extensibility, wear durability, and non-adhesiveness), and productivity can be maintained. .
[0027]
[Example]
Next, examples of the surface treatment agent produced based on the present embodiment will be described. First, 100 parts by weight of polyether polyol, 30 parts by weight of nylon powder, 25 parts by weight of silicone oil, and 5 parts by weight of carbon black were mixed to obtain a main component of the surface treatment agent.
[0028]
Further, 50 parts by weight of hexamethylene diisocyanate and 50 parts by weight of diphenylmethane diisocyanate are mixed, and the mixture consists of methyl ethyl ketone oxime (2-butanone oxime; C ₄ H ₉ NO) having a dissociation temperature of 130 ° C. to 140 ° C. By adding 0 to 27.2 parts by weight of the blocking agent, a curing agent in which the isocyanate groups of the mixture were partially masked within a block ratio of 0 to 70% was obtained.
[0029]
And each hardening | curing agent was added and mixed with respect to the said main ingredient, and sample S1-S8 of the surface treating agent of a composition shown in following Table 3 was produced. In addition, it shows in following Table 4 about the kind of main ingredient and hardening | curing agent which were used for each said samples S1-S8.
[0030]
[Table 3]

[0031]
[Table 4]

[0032]
For each of the samples S1 to S8, the viscosity (target value; 20 Pa · s or less), the curing reaction time when cured by heating at a temperature of 100 ° C. or 120 ° C. (target value; 8 hours or more in the case of 100 ° C., In the case of 120 ° C., 4 hours or more) were examined. Moreover, in the production line of an actual polymer material composition using an extrusion molding machine, the samples S1 to S8 are applied to the extrusion molding at a thickness of 100 μm or 150 μm (coating simultaneously with the extrusion molding), The curability of each of the samples S1 to S8 (target; that the sample is sufficiently cured) when each of the extruded products was vulcanized was examined.
[0033]
Further, when the samples S1 to S8 are used in the polymer material composition, the elongation, wear durability, non-adhesiveness, friction coefficient, and sliding resistance of the samples S1 to S8 are as follows. Each was examined. The test piece shown below is a flat plate member (rubber obtained by applying a sample (any one of samples S1 to S8) to the surface of a rubber plate having a thickness of 2 mm and curing the sample by heating. Member having a coating film of the sample formed on the plate surface).
[0034]
(Elongation)
A standard line with a length of 20 mm is described with respect to the central portion on one end face side of a flat-plate (length 150 mm, width 10 mm) test piece, and the test piece is pulled by a tensile tester (tensile speed: 200 mm / min) The elongation percentage (target value; 100% or more) of the test piece when a crack occurred in the coating film was measured.
[0035]
(Abrasion durability)
As shown in the schematic explanatory diagram of the method using the constant load friction tester in FIG. 1, first, on the coating film (coating film made of a sample) 11a of the test piece 11 having a flat plate shape (length 80 mm, width 3 mm). A glass plate 12 (a glass plate having a longitudinal width of the test piece 11 of 30 mm) was brought into contact, and an iron plate 13 was brought into contact with the other end surface of the test piece 11. And while fixing the said test piece 11, while applying the load of 9.8N with respect to the said test piece 11 via the said iron plate 13, the said glass plate 12 is shown in the direction of the white arrow shown in the figure (longitudinal direction of the test piece 11). The glass plate 12 was slid on the surface of the coating film 11a, and the number of times of reciprocation when the rubber plate surface was exposed due to laceration of the coating film 11a was measured (target value: 20,000 times). more than).
[0036]
In this embodiment, the wear durability is measured by setting the stroke and cycle of the glass plate 12 to 50 mm and 60 times / min, respectively, and 0.5 cc of dust (water) every time the reciprocating motion is performed 500 times. : Dust = 3: 1) was added to the sliding surface.
[0037]
(Non-adhesive)
As shown in the schematic explanatory views of FIGS. 2A (plan view) and B (side view), first, two flat plates (length 50 mm, width 5 mm) are provided via a double-sided tape (a film having double-sided adhesive properties). The surface of the test piece 21 where the rubber plate was exposed was adhesively fixed to the iron plate 23. Further, the glass plate 22 is positioned so as to cover the surface of the coating film 21a of each test piece 21, and the glass plate 22 and the iron plate 23 are combined with a commercially available clip 26 so as to compress each test piece 21 with a predetermined pressure. The sample was sandwiched and exposed for 200 hours in a rain-free atmosphere (temperature 83 ° C. atmosphere) using a sunshine weather meter.
[0038]
After that, the clip 26 is removed, and only the glass plate 22 is pulled at a speed of 50 mm / min in the direction of the illustrated white arrow with the iron plate 23 fixed, and the glass plate 22 and each test piece at that time are pulled. The peel strength was measured (target value: 50 N or less).
[0039]
(Coefficient of friction)
As shown in the schematic explanatory diagram of FIG. 3, first, the surface of the test piece 31 having a flat plate shape (length 100 mm, width 20 mm) on which the rubber plate was exposed was adhesively fixed to the iron plate 33 via a double-sided tape. Further, the glass member (member provided with a hemispherical glass 34a) 34 is brought into contact with the surface of the coating film 31a of the test piece 31 (the glass 34a spherical surface is brought into contact with the surface of the coating film 31a), and A load cell 35 was connected to the glass member 34.
[0040]
Then, a weight 34b having a weight of 100 g is placed on the glass member 34 (that is, a load of about 0.98 N is applied to the test piece 31), and the glass 34a spherical surface slides on the surface of the coating film 31a ( By moving the iron plate 33 in the direction of the white arrow in the figure so as to slide in the longitudinal direction of the test piece 31 (moving in the longitudinal direction of the test piece 31), the static friction coefficient of the test piece 31 ("moving the iron plate 33") The maximum frictional resistance value at the start ”/“ load (about 0.98 N) ”) and the dynamic friction coefficient (“ average frictional resistance value during movement of the iron plate 33 ”/“ load (about 0.98 N) ”) are obtained by the load cell 35. Measured (target value: 1.0 or less for static friction coefficient, 0.3 or less for dynamic friction coefficient).
[0041]
(Sliding resistance)
As shown in the schematic explanatory diagram of FIG. 4, first, a sample (any one of samples S1 to S8) is applied to the surface of a glass run (length 500 mm) 41 used in an automobile or the like, and the sample is heated. Cured to form a coating film (not shown). Further, the glass run 41 is fixed, and a glass plate (a glass plate having a length of 200 mm and a thickness of 4 mm) 42 is placed on the glass run 41 (coating surface) (the longitudinal direction of the glass run 41 and the glass plate 42). The load cell 45 was connected to the glass plate 42.
[0042]
Then, by reciprocating the glass plate 42 at 3000 mm / min in the direction of the outlined arrow (longitudinal direction of the glass run 41), an average frictional resistance value when the glass plate 42 is slid on the coating film surface is obtained. Measured (target value; 10 N or less).
[0043]
The characteristics of the samples S1 to S8 measured as described above are shown in Table 5 below. In Table 5 below, the symbol “◯” in the curability column indicates that the curing is sufficient, and the symbol “x” indicates that the curing is insufficient. In addition, the symbol “◯” in the column of comprehensive evaluation is excellent as a surface treatment agent used at the time of extrusion molding of the polymer material composition (the slidability of the polymer material composition can be improved and productivity can be maintained). ), The symbol “x” is ineligible.
[0044]
[Table 5]

[0045]
From the results shown in Table 5 above, samples S6 to S8 using a curing agent having a partial masking ratio of isocyanate groups of 50% to 70% can secure a sufficiently long curing reaction time, but increase the block ratio. Accordingly, it can be read that the viscosity increases (that is, the applicability deteriorates) and the curability deteriorates. Sample S1, which does not contain a blocking agent, is excellent in curability, extensibility, wear durability, and non-adhesiveness, and provides good viscosity, coefficient of friction, and sliding resistance, but the curing reaction time is shortened. I can read that.
[0046]
On the other hand, samples S2 to S5 using a curing agent having a partial masking ratio of isocyanate groups of 10% to 40% are excellent in curability, elongation, wear durability, and non-adhesiveness, and also have good viscosity and curing. The reaction time, coefficient of friction, and sliding resistance were obtained, and it was confirmed that the surface treatment agent used in the extrusion molding of the polymer material composition was excellent.
[0048]
Although the present invention has been described in detail only for the specific examples described above, it is obvious to those skilled in the art that various changes and modifications can be made within the scope of the technical idea of the present invention. Of course, such variations and modifications fall within the scope of the appended claims.
[0049]
【The invention's effect】
As described above, according to the present invention, the surface treatment agent is obtained by partially masking the isocyanate group of the curing agent (for example, partially masking at a block ratio of 10% to 40%) with a blocking agent having a dissociation temperature of 130 ° C to 160 ° C. By controlling the curing reaction rate of the surface treatment agent, the viscosity of the surface treatment agent is sufficiently low, and an unintended curing reaction can be prevented (for example, it is not cured by heat during extrusion (heat of the extrusion die)). Applicability can be obtained and productivity can be maintained.
[0050]
In addition, since the surface treatment agent cures reliably with heat at a predetermined temperature (heat when vulcanizing the polymer material composition), the surface treatment agent is stretchable, wear-resistant and non-adhesive to the polymer material composition. A good coating film can be formed and excellent slidability can be obtained.
[Brief description of the drawings]
BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a schematic explanatory view showing a method for measuring elongation in the present example.
FIG. 2 is a schematic explanatory view showing a non-adhesive measuring method in this example.
FIG. 3 is a schematic explanatory view showing a method of measuring a friction coefficient in the present embodiment.
FIG. 4 is a schematic explanatory view showing a method for measuring sliding resistance in the present embodiment.
[Explanation of symbols]
11, 21, 31 ... Test pieces 11a, 21a, 31a ... Coating films 12, 22, 42 ... Glass plates 13, 23, 33 ... Iron plate 34 ... Glass members 35, 45 ... Load cell 41 ... Glass run

Claims (3)

A curing agent having an isocyanate group, and a main agent having a polyol to be reacted with the curing agent ,
A surface treatment agent for a rubber composition that is applied at the time of extrusion molding in rubber extrusion vulcanization molding and can impart slidability to the surface of the extrusion molded article,
The isocyanate group was partially masked by a blocking agent having a dissociation temperature of 130 ° C. to 160 ° C. within a range of a block rate of 10% to 60% , and the curing reaction rate during the extrusion molding was suppressed according to the block ratio. A surface treatment agent for a rubber composition . The surface treatment agent for a rubber composition according to claim 1, wherein the block ratio of the partial masking is in the range of 10% to 40%. 3. The surface treatment agent for a rubber composition according to claim 1, wherein the blocking agent comprises oxime .

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