JP6503074B2 - Organic polymer fine particles - Google Patents

Description

  The present invention relates to organic polymer microparticles.

Heretofore, resin compositions in which organic or inorganic fine particles are contained in a base resin have been proposed for the purpose of improving physical properties such as blocking resistance and slipperiness of resin molded articles and imparting further properties. . Such fine particles are often mixed with a base resin, and if the heat resistance of the fine particles is inferior, they are decomposed by heating at the time of molding processing to cause appearance defects (voids, coloring, etc.) of the molded product. Since there is a problem of raising or lowering mechanical properties, fine particles excellent in heat resistance are required.
Patent Document 1 is obtained by polymerizing a monomer component containing a (meth) acrylic monomer, and contains 10 ppm or more (mass basis) of an antioxidant containing a thioether compound essentially as a sulfur antioxidant. Organic polymer fine particles having an average particle diameter of 0.5 μm to 40 μm and a thermal decomposition start temperature of 290 ° C. or higher are described. In suspension polymerization in an aqueous phase, it is known to add a water-soluble polymerization inhibitor such as sodium nitrite or the like into the system in order to suppress the generation of by-product fine particles due to concurrent emulsion polymerization ( Patent Document 2).
In the production of the organic polymer fine particles, seed polymerization or suspension polymerization is used. In seed polymerization, particles having a relatively uniform particle diameter can be easily obtained, but the production cost tends to be high. In suspension polymerization, although the manufacturing cost is suppressed, microparticles are easily generated. Patent Document 3 describes a spherical gap agent produced by seed polymerization. In the examples, spherical gap agents having a particle diameter CV value (coefficient of variation) of 10% or less are obtained, and 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl is used in the reaction. ing.
In the production of organic polymer fine particles, it is preferable to produce organic polymer fine particles excellent in heat resistance by suspension polymerization, from the viewpoint of low production cost.

International Publication No. 2008/133147 Japanese Patent Application Laid-Open No. 7-316209 JP, 2015-72364, A

Accordingly, the object of the present invention is to provide organic polymer fine particles having high heat resistance, and organic polymer fine particles of which cost can be suppressed by suspension polymerization and organic polymer fine particles having high heat resistance can be produced. It is in providing a manufacturing method.

The present inventors have found that when producing organic polymer fine particles by suspension polymerization, organic polymer fine particles having high heat resistance can be obtained by suppressing the generation of the fine particles. Furthermore, it has been found that generation of fine particles can be suppressed by containing a specific compound in suspension polymerization, and organic polymer fine particles with high heat resistance can be produced.
That is, the organic polymer fine particle of the present invention contains a polymer containing a structural unit derived from a vinyl monomer and a nitroxyl radical compound, and the CV value (coefficient of variation) of the particle diameter is 15% or more.
The nitroxyl radical compound is preferably 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl.
The vinyl monomer preferably contains a styrene monomer.
Moreover, it is preferable that the said vinyl-type monomer contains a maleimide-type monomer.
Moreover, it is preferable that the said vinyl-type monomer contains a (meth) acrylic-type monomer. More preferably, the vinyl-based monomer contains at least two of the styrene-based monomer, maleimide-based monomer, and (meth) acrylic-based monomer.
The present invention includes an additive for a thermoplastic resin containing the above-mentioned organic polymer fine particles, and an antiblocking agent for a thermoplastic resin containing the above-mentioned organic polymer fine particles. Moreover, the masterbatch containing the said additive agent for thermoplastic resins and a thermoplastic resin is a suitable aspect of this invention.
The method for producing organic polymer fine particles of the present invention is characterized in that a vinyl monomer is suspension-polymerized in the presence of a nitroxyl radical compound.
The nitroxyl radical compound is preferably 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl.
The vinyl monomer preferably contains a styrene monomer.
Moreover, it is preferable that the said vinyl-type monomer contains a maleimide-type monomer.
Moreover, it is preferable that the said vinyl-type monomer contains a (meth) acrylic-type monomer. More preferably, the vinyl-based monomer contains at least two of the styrene-based monomer, maleimide-based monomer, and (meth) acrylic-based monomer.

  In the present invention, by adding a specific compound at the time of suspension polymerization, it is possible to provide an organic polymer fine particle having high heat resistance and a small number of fine particles. In addition, by adding a specific compound at the time of suspension polymerization, it is possible to provide a method for producing organic polymer fine particles capable of producing organic polymer fine particles with high cost resistance and suppressed in cost.

2 is a scanning electron micrograph of the surface of the biaxially stretched film of Example 1. FIG. It is a figure which shows the TG (Thermo gravity) curve measured on the conditions hold | maintained at 280 degreeC (highest achieved temperature) for 2 hours of microparticles | fine-particles and suspension particle | grains. It is a figure which shows the TG (Thermo gravity) curve measured on the conditions hold | maintained at 230 degreeC (maximum achieved temperature) for 2 hours of the organic polymer microparticles | fine-particles of Example 1 and the comparative example 1. FIG.

［式（Ｉ）中、Ｒ^１１及びＲ^１２は、それぞれ独立して、水素原子、ハロゲン原子、炭素数１〜１５のアルキル基、炭素数１〜１５のアリール基又は炭素数１〜１５のアラルキル基を示し、Ｒ^１３は炭素数１〜１５のアルキル基、炭素数１〜１５のアリール基又は炭素数１〜１５のアラルキル基を示す。］
Ｒ^１１〜Ｒ^１３で表されるアルキル基としては、メチル基、エチル基、プロピル基、ブチル基、ペンチル基、ヘキシル基、ヘプチル基、オクチル基、ノニル基、デシル基、ウンデシル基、ドデシル基、トリデシル基、テトラデシル基、ペンタデシル基等の直鎖状アルキル基；イソプロピル基、イソブチル基、ｔｅｒｔ−ブチル基等の分岐状アルキル基；シクロプロピル基、シクロブチル基、シクロペンチル基、シクロヘキシル基等の環状アルキル基が挙げられる。Ｒ^１１〜Ｒ^１３で表されるアリール基としては、フェニル基、ナフチル基等が挙げられる。なお、これらのアルキル基、アリール基が有する水素原子は、さらにアルキル基、アリール基、ハロゲン原子、ニトロ基等で置換されていてもよい。Ｒ^１１〜Ｒ^１３で表されるアラルキル基としては、ベンジル基、フェネチル基、３−フェニルプロピル基等が挙げられる。
上記マレイミド系単量体の具体例としては、例えば、マレイミド；Ｎ−メチルマレイミド、Ｎ−エチルマレイミド、Ｎ−プロピルマレイミド、Ｎ−ブチルマレイミド、Ｎ−シクロヘキシルマレイミド、Ｎ−ラウリルマレイミド等のＮ−アルキルマレイミド；Ｎ−フェニルマレイミド、Ｎ−（２−クロロフェニル）マレイミド、Ｎ−（３−クロロフェニル）マレイミド、Ｎ−（４−クロロフェニル）マレイミド、Ｎ−（４−ブロモフェニル）マレイミド、Ｎ−（２，４，６−トリクロロフェニル）マレイミド、Ｎ−（２，４，６−トリブロモ）マレイミド、Ｎ−（２−ニトロフェニル）マレイミド、Ｎ−（３−ニトロフェニル）マレイミド、Ｎ−（４−ニトロフェニル）マレイミド、Ｎ−（２，４−ジニトロフェニル）マレイミド、Ｎ−（２−ヒドロキシフェニル）マレイミド、Ｎ−（３−ヒドロキシフェニル）マレイミド、Ｎ−（４−ヒドロキシフェニル）マレイミド、Ｎ−（４−フェニルフェニル）マレイミド、Ｎ−ナフチルマレイミド等のＮ−アリールマレイミド；Ｎ−（２−メチルフェニル）マレイミド、Ｎ−（３−メチルフェニル）マレイミド、Ｎ−（４−メチルフェニル）マレイミド、Ｎ−（２−ブチルフェニル）マレイミド、Ｎ−（３−ブチルフェニル）マレイミド、Ｎ−（４−ブチルフェニル）マレイミド、Ｎ−（２，６−ジメチルフェニル）マレイミド等のＮ−アルキルアリールマレイミド；Ｎ−（２−メトキシフェニル）マレイミド、Ｎ−（３−メトキシフェニル）マレイミド、Ｎ−（４−メトキシフェニル）マレイミド、Ｎ−（４−エトキシフェニル）マレイミド、Ｎ−（２−メトキシ−４−クロロフェニル）マレイミド等のアルコキシアリールマレイミド；Ｎ−（４−フェニルオキシフェニル）マレイミド等のアリールオキシアリールマレイミド；ベンジルマレイミド等のアラルキルマレイミド；等が挙げられる。これらのマレイミド系単量体は単独で使用してもよいし、２種以上を併用してもよい。これらの中でも、Ｎ−アルキルマレイミド（好ましくはＮ−環状アルキルマレイミド）、Ｎ−アリールマレイミドが好ましく、特にＮ−シクロヘキシルマレイミド、Ｎ−フェニルマレイミドが好適である。
上記マレイミド系単量体の含有量は、上記ビニル系単量体１００質量部中０〜４０質量部が好ましく、より好ましくは０〜２５質量部、さらに好ましくは１〜２５質量部である。上記マレイミド系単量体の含有量が１質量部以上であればマレイミド系単量体による熱分解開始温度上昇効果を十分に得られるようになり、３０質量部以下であれば、有機重合体微粒子の無色性（白色性）が向上する。
１−１−１−４ 架橋剤
本発明の有機重合体微粒子は、上記ビニル系単量体として架橋剤を構成成分として含んでもよい。上記（メタ）アクリル系単量体のうち、２以上の重合性基を有するものは、架橋剤となりうる。この他、ジビニルベンゼン、ジビニルナフタレン、および、これらの誘導体等の芳香族ジビニル化合物；Ｎ，Ｎ−ジビニルアニリン、ジビニルサルファイド、ジビニルスルホン酸；ジビニルエーテル、エチレングリコールジビニルエーテル、ジエチレングリコールジビニルエーテル、ポリエチレングリコールジビニルエーテル、プロピレングリコールジビニルエーテル、ブチレングリコールジビニルエーテル、ヘキサンジオールジビニルエーテル、ビスフェノールＡアルキレンオキシドジビニルエーテル、ビスフェノールＦアルキレンオキシドジビニルエーテル、トリメチロールプロパントリビニルエーテル、ジトリメチロールプロパンテトラビニルエーテル、グリセリントリビニルエーテル、ペンタエリスリトールテトラビニルエーテル、ジペンタエリスリトールペンタビニルエーテル、ジペンタエリスリトールヘキサビニルエーテル、エチレンオキシド付加トリメチロールプロパントリビニルエーテル、エチレンオキシド付加ジトリメチロールプロパンテトラビニルエーテル、エチレンオキシド付加ペンタエリスリトールテトラビニルエーテル、エチレンオキシド付加ジペンタエリスリトールヘキサビニルエーテル等の多官能ビニルエーテル類；エチレングリコールジアリルエーテル、ジエチレングリコールジアリルエーテル、ポリエチレングリコールジアリルエーテル、プロピレングリコールジアリルエーテル、ブチレングリコールジアリルエーテル、ヘキサンジオールジアリルエーテル、ビスフェノールＡアルキレンオキシドジアリルエーテル、ビスフェノールＦアルキレンオキシドジアリルエーテル、トリメチロールプロパントリアリルエーテル、ジトリメチロールプロパンテトラアリルエーテル、グリセリントリアリルエーテル、ペンタエリスリトールテトラアリルエーテル、ジペンタエリスリトールペンタアリルエーテル、ジペンタエリスリトールヘキサアリルエーテル、エチレンオキシド付加トリメチロールプロパントリアリルエーテル、エチレンオキシド付加ジトリメチロールプロパンテトラアリルエーテル、エチレンオキシド付加ペンタエリスリトールテトラアリルエーテル、エチレンオキシド付加ジペンタエリスリトールヘキサアリルエーテル等の多官能アリルエーテル類などを使用できる。架橋剤としては、これらを単独で使用してもよいし、２種以上を併用してもよい。また、（メタ）アクリル系単量体のうち架橋剤として使用されるものとしては、上記（Ｂ）多官能（メタ）アクリレート系単量体が好ましい。
架橋剤の含有量は、上記ビニル系単量体１００質量部中０．１〜５０質量部が好ましく、１〜２０質量部がより好ましく、さらに好ましくは２〜１５質量部である。架橋剤の含有量が５０質量部以下であれば、質量減少開始温度、熱分解開始温度により優れる粒子となる。その理由は、上記含有量が５０質量部以下であれば、製造時の重合反応で架橋剤に由来して残留しやすい二重結合が、残存し難くなるため、残存二重結合を起点とする分解が抑制されるためと考えられる。また、上記含有量が０．１質量部以上であれば、樹脂組成物を調製する際や樹脂組成物を加工する際において、その溶融や加工時の加熱による有機重合体微粒子の変形が抑制される。なお、本明細書において、Ａ〜Ｂとの記載は、ＡならびにＢを含むＡ以上Ｂ以下と同義である。
１−１−１−５ 他の単量体
本発明の有機重合体微粒子は、本発明の効果を損なわない程度であれば、上記（メタ）アクリル系単量体、上記スチレン系単量体、上記マレイミド系単量体、ならびに上記架橋剤と異なる他の単量体を構成成分として含んでもよい。他の単量体を用いる場合、その使用量は全ビニル系単量体１００質量部中２０質量部以下が好ましく、より好ましくは１０質量部以下である。
１−２ ニトロキシルラジカル化合物
本発明の有機重合体微粒子は、ニトロキシルラジカル化合物を含有する。本発明の有機重合体微粒子では、上記ニトロキシルラジカル化合物を含有することにより、耐熱性が向上する。上記ニトロキシルラジカル化合物としては、例えば、４−ヒドロキシ−２，２，６，６−テトラメチルピペリジン−１−オキシル、２，２，６，６−テトラメチルピペリジン−１−オキシル、４−ベンゾイルオキシ−２，２，６，６−テトラメチルピペリジン−１−オキシル、５，５−ジメチル−１−ピロリンＮオキシド等が例示され、これらの１種又は２種以上を用いることができる。上記ニトロキシルラジカル化合物の中でも、下記式（ＩＩ）で表される４−ヒドロキシ−２，２，６，６−テトラメチルピペリジン−１−オキシル（４Ｈ−ＴＥＭＰＯ）が好ましい。

上記ニトロキシルラジカル化合物の含有量は、ビニル系単量体成分総量に対して質量基準で、１０〜１０００ｐｐｍが好ましく、５０〜７００ｐｐｍがより好ましく、７０〜５００ｐｐｍがより好ましい。上記ニトロキシルラジカル化合物の含有量が１０ｐｐｍより少ない場合には、十分な耐熱性が得られにくく、１０００ｐｐｍを超えると、重合性が不十分となる場合がある。
１−３ 粒子径
本発明に係る有機重合体微粒子の平均粒子径（体積平均粒子径）は、０．１〜１００μｍであることが好ましく、より好ましくは０．３〜５０μｍ、さらに好ましくは０．５〜３０μｍである。平均粒子径が０．１μｍよりも小さい場合、耐ブロッキング性効果および滑り性向上効果が十分に発現しないために多量の添加を必要としフィルムの機械的強度が損なわれる虞れがある。一方、平均粒子径が１００μｍよりも大きい場合、フィルムから粒子が脱落し易くなり、機械的強度の低下を引き起こす虞れがある。なお、本明細書において「平均粒子径」とは、「体積平均粒子径」のことである。
１−４ 粒子径のＣＶ値（変動係数）
本発明の有機重合体微粒子は、粒子径のＣＶ値（変動係数）が１５％以上であり、好ましくは１５〜７０％、より好ましくは２０〜６５％、さらに好ましくは２５〜６０％である。ＣＶ値が１５％より小さい粒子を得るには、懸濁重合の場合には分級工程を実施する必要があり、製造コストが高くなる。なお、ＣＶ値が大きいと粗大粒子の量が多くなり、フィルムから粒子が脱落し易くなり、機械的強度の低下を引き起こしやすくなるため好ましくない。
粒子径のＣＶ値（変動係数）は、下記式に従って算出できる。
粒子径のＣＶ値（％）＝１００×（粒子径の標準偏差／体積平均粒子径）
なお、粒子径の標準偏差は、体積基準の粒子径分布より求めた数値である。
本発明の有機重合体微粒子では、懸濁重合により製造されるため、粒子径のＣＶ値（変動係数）は１５％以上となる。
１−５ 粒子形状
本発明に係る有機重合体微粒子は真球状粒子だけでなく、多孔質粒子や、粒子表面に多数の凹凸を有する異形粒子も含まれる。樹脂フィルムのアンチブロッキング剤として使用した場合、フィルムを延伸した際に、ボイドの抑制や粒子の脱落を低減する観点から、フィルムと有機重合体粒子の接触面が大きいことが好ましい。有機重合体粒子の表面積を大きくするために、真球状粒子よりも多孔質粒子や異形粒子といった形状が必要とされる場合がある。
１−６ 酸化防止剤
本発明に係る有機重合体微粒子は、酸化防止剤を含むものであってもよい。酸化防止剤を含むことにより、耐熱性をより向上できる。酸化防止剤としては、ヒンダードフェノール系酸化防止剤、硫黄系酸化防止剤、リン系酸化防止剤、ラクトン系酸化防止剤、ヒドロキシルアミン系酸化防止剤、およびビタミンＥ系酸化防止剤などが挙げられる。なお、上記ヒンダードフェノール系酸化防止剤とは、当該酸化防止剤の構造中に、パラ置換２，６−ジ−ｔｅｒｔ−ブチルフェノール構造を有するものを意味し、硫黄系酸化防止剤は、硫黄元素を含み、酸化防止機能を有するもの、リン系酸化防止剤は、その構造中にリン原子を含むもの、ラクトン系酸化防止剤は、環状のエステル構造を有するものを意味する。これらの構造は２種以上を同時に含んでいてもよく、この場合、本明細書では、主として酸化防止効果を発揮する部分に応じて、各酸化防止剤を分類する。
従来公知の硫黄系酸化防止剤としては、芳香環を有するものとして、チオジエチレンビス［３−（３，５−ジ−ｔｅｒｔ−ブチル−４−ヒドロキシフェニル）プロピオネート］、４，６−ビス（ドデシルチオメチル）−ｏ−クレゾール、４，６−ビス（オクチルチオメチル）−ｏ−クレゾール、２，６−ジ−ｔｅｒｔ−ブチル−４−（４，６−ビス（オクチルチオ）−１，３，５−トリアジン−２−イルアミノ）フェノール等、芳香環を有さないものとして、ペンタエリスリチルテトラキス（３−ラウリルチオプロピオネート）、ジドデシル−３，３’−チオジプロピオネート、ジオクタデシル−３，３’−チオジプロピオネート、ジミリスチル−３，３−チオプロピオネート、ジトリデシル−３，３−チオジプロピオネート等などが挙げられる。これらの中でも、チオエーテル系化合物（Ｃ−ＳＣ結合を有する）が好ましく、特に、ペンタエリスリチルテトラキス（３−ラウリルチオプロピオネート）が好ましい。これらの硫黄系酸化防止剤は、安価に入手できるので好ましい。
また、下記式（１）で表される構造単位を有する化合物（１）も、本発明に係る硫黄系酸化防止剤として好ましく使用できる。

尚、式（１）中、ｎは１〜５の整数（好ましくは、ｎ＝２）を意味する。
化合物（１）の中でも、上記式（１）で表される構造単位を分子内に２個以上有する化合物が好ましい。より好ましくは、上記式（１）で表される構造単位を分子内に２〜４個有する化合物であり、特に好ましいのは、上記式（１）で表される構造単位を分子内に４個有する化合物である。
また、上記化合物（１）の中でも、下記式（２）で表される構造単位を有する化合物（２）が好ましい。化合物（２）としてより好ましいのは、分子中に下記式（２）で示される構造単位を２〜４個有する化合物であり、さらに好ましくは、下記式（２）で示される構造単位を４個有する化合物である。

ここで、ｎは１〜５の整数（好ましくはｎ＝２）であり、Ｒ^１はアルキル基、アリール基、アラルキル基、アルケニル基よりなる群から選ばれる少なくとも１種の基であり、Ｒ^１は置換基を有していてもよい。
上記アルキル基としては、耐熱性向上の効果が高い点で、炭素数１〜２０のアルキル基が好ましく、より好ましくは３〜２０、さらに好ましくは６〜１８のアルキル基である。例えば、プロピル基、ブチル基、ペンチル基、ヘキシル基、オクチル基、ドデシル基（ラウリル基）、トリデシル基、ミリスチル基、オクタデシル基（ステアリル基）等のアルキル基が挙げられる。
アリール基としては、フェニル基、ヒドロキシフェニル基、トリル基、ｏ−キシリル基などが挙げられる。これらの中でも、フェニル基、ヒドロキシフェニル基が好ましい。
アラルキル基としては、ベンジル基、メチルベンジル基、フェネチル基、メチルフェネチル基、フェニルベンジル基、ナフチルメチル基などが挙げられ、アルケニル基としては、ビニル基、アリル基、プロペニル基、１−ブテニル基、２−ブテニル基などが挙げられる。
これらの中でも、アルキル基、アリール基が好ましく、特に好ましいのはアルキル基である。
上記置換基としては、ヒドロキシル基、アミノ基、カルボキシル基、アルキル基、アリール基、アラルキル基、アルケニル基などが例示される。
上記式（２）で表される構造単位を４個有する化合物（２）としては、例えば、ペンタエリスリチルテトラキス（３−アルキルチオプロピオネート）化合物が好ましく挙げられる。具体的には、ペンタエリスリチルテトラキス（３−メチルチオプロピオネート）、ペンタエリスリチルテトラキス（３−エチルチオプロピオネート）、ペンタエリスリチルテトラキス（３−プロピルチオプロピオネート）、ペンタエリスリチルテトラキス（３−ブチルチオプロピオネート）、ペンタエリスリチルテトラキス（３−ヘキシルチオプロピオネート）、ペンタエリスリチルテトラキス（３−オクチルチオプロピオネート）、ペンタエリスリチルテトラキス（３−ラウリルチオプロピオネート）、ペンタエリスリチルテトラキス（３−トリデシルチオプロピオネート）、ペンタエリスリチルテトラキス（３−ミリスチルチオプロピオネート）、ペンタエリスリチルテトラキス（３−ステアリルチオプロピオネート）、ペンタエリスリチルテトラキス（３−フェニルチオプロピオネート）などが例示される。中でも、炭素数３〜２０のアルキル基を有するものが好ましく、さらに好ましくはアルキル基の炭素数が６〜１８、特に好ましくはアルキル基の炭素数が１２〜１８の化合物である。
特に、炭素数１２のアルキル基を有する、ペンタエリスリチルテトラキス（３−ラウリルチオプロピオネート）は工業的に入手し易く好ましい。
また、化合物（１）の中でも、下記式（３）で示される構造単位を有する化合物（３）も、本発明に係る硫黄系酸化防止剤として好ましく用いられる。

式（３）中、ｎは１〜５の整数（好ましくはｎ＝２）である。
上記式（３）で示される構造単位を有する化合物（３）の中でも、下記式（４）で示される構造単位を有する化合物はより好ましい。

ｎは１〜５の整数（好ましくはｎ＝２）である。
式（４）中、Ｒ^２およびＲ^３は、それぞれ独立して、アルキル基、アリール基、アラルキル基、アルケニル基からなる群より選ばれる少なくとも１種の基であり、また、Ｒ^２およびＲ^３は置換基を有していてもよい。なお、アルキル基、アリール基、アラルキル基、アルケニル基としては、上記化合物（２）におけるＲ^１の場合と同様のものが好ましく例示できる。尚、Ｒ^２およびＲ^３として好ましいのは、アルキル基、アリール基であり、特に好ましいのは、アルキル基である。
上記置換基としては、アルキル基、アリール基、アラルキル基、アルケニル基、ヒドロキシル基、アミノ基、カルボキシル基などが例示される。
式（４）で表される構造単位を有する化合物（３）としては、例えば、ジアルキル−３，３’−チオジプロピオネート化合物が好ましく挙げられる。具体的には、ジメチル−３，３’−チオジプロピオネート、ジエチル−３，３’−チオジプロピオネート、ジプロピル−３，３’−チオジプロピオネート、ジブチル−３，３’−チオジプロピオネート、ジヘキシル−３，３’−チオジプロピオネート、ジオクチル−３，３’−チオジプロピオネート、ジドデシル−３，３’−チオジプロピオネート（ジラウリル−３，３’−チオジプロピオネート）、ジミリスチル−３，３’−チオジプロピオネート、ジトリデシル−３，３’−チオジプロピオネート、ジオクタデシル−３，３’−チオジプロピオネート（ジステアリル−３，３’−チオジプロピオネート）などが例示される。これらの中でも、炭素数３〜２０のアルキル基を有するものが好ましく、より好ましくはアルキル基の炭素数が６〜１８の化合物、さらに好ましくはアルキル基の炭素数が１２〜１８の化合物である。
特に、炭素数１２〜１８のアルキル基を有するジドデシル−３，３’−チオジプロピオネート、ジミリスチル−３，３’−チオジプロピオネート、ジトリデシル−３，３’−チオジプロピオネート、ジオクタデシル−３，３’−チオジプロピオネートは工業的に入手が容易であるので好ましい。
上記ヒンダードフェノール系酸化防止剤としては、具体的には、ペンタエリスリトールテトラキス［３−（３，５−ジ−ｔｅｒｔ−ブチル−４−ヒドロキシフェニル）プロピオネート］、オクタデシル−３−（３，５−ジ−ｔｅｒｔ−ブチル−１−ヒドロキシフェニル）プロピオネート、Ｎ，Ｎ’−ヘキサン−１，６−ジイルビス［３−（３，５−ジ−ｔｅｒｔ−ブチル−４−ヒドロキシフェニル）プロピオンアミド］、ベンゼンプロパン酸，３，５−ビス（１，１−ジメチルエチル）−４−ヒドロキシ，Ｃ７−Ｃ９側鎖アルキルエステル、３，３’，３’’，５，５’，５’’−ヘキサ−ｔｅｒｔ−ブチル−ａ，ａ’，ａ’’−（メシチレン−２，４，６−トリル）トリ−ｐ−クレゾール、カルシウムジエチルビス［［［３，５−ビス（１，１−ジメチルエチル）−４−ヒドロキシフェニル］メチル］ホスホネート］、エチレンビス（オキシエチレン）ビス［３−（５−ｔｅｒｔ−ブチル−４−ヒドロキシ−ｍ−トリル）プロピオネート］、ヘキサメチレンビス［３−（３，５−ジ−ｔｅｒｔ−ブチル−４−ヒドロキシフェニル）プロピオネート］、１，３，５−トリス（３，５−ジ−ｔｅｒｔ−ブチル−４−ヒドロキシベンジル）−１，３，５−トリアジン−２，４，６（１Ｈ，３Ｈ，５Ｈ）−トリオン、１，３，５−トリス［（４−ｔｅｒｔ−ブチル−３−ヒドロキシ−２，６−キシリル）メチル］−１，３，５−トリアジン−２，４，６（１Ｈ，３Ｈ，５Ｈ）−トリオン、Ｎ−フェニルベンゼンアミンと２，４，４−トリメチルベンゼンとの反応生成物、ジエチル［［３，５−ビス（１，１−ジメチルエチル）−４−ヒドロキシフェニル］メチル］ホスホネート、２，４−ジメチル−６−（１−メチルペンタデシル）フェノール、オクタデシル−３−（３，５−ｔｅｒｔ−ブチル−４−ヒドロキシフェニル）プロピオネート、２’，３−ビス［３−（３，５−ジ−ｔｅｒｔ−ブチル−４−ヒドロキシフェニル）プロピオニル］プロピオノヒドラジド等が挙げられる。
上記リン系酸化防止剤としては、トリス（２，４−ジ−ｔｅｒｔ−ブチルフェニル）フォスファイト、トリス［２−［［２，４，８，１０−テトラ−ｔｅｒｔ−ブチルジベンゾ［ｄ、ｆ］［１，３，２］ジオキサフォスフェフィン−６−イル］オキシ］エチル］アミン、ビス（２，４−ジ−ｔｅｒｔ−ブチルフェニル）ペンタエリスリトールジフォスファイト、ビス［２，４−ビス（１，１−ジメチルエチル）−６−メチルフェニル］エチルエステル亜リン酸、テトラキス（２，４−ジ−ｔｅｒｔ−ブチルフェニル）［１，１−ビフェニル］−４，４’−ジイルビスホスフォナイト等が挙げられる。
上記ラクトン系酸化防止剤としては、３−ヒドロキシ−５，７−ジ−ｔｅｒｔ−ブチル−フラン−２−オンとｏ−キシレンの反応生成物（ＣＡＳ Ｎｏ．１８１３１４−４８−７）等が挙げられる。
酸化防止剤としては、他に、上記還元型牛脂を原料としたアルキルアミンの酸化生成物等のヒドロキシルアミン系酸化防止剤；３，４−ジヒドロ−２，５，７，８−テトラメチル−２−（４，８，１２−トリメチルトリデシル）−２Ｈ−ベンゾピラン−６−オール等のビタミンＥ系酸化防止剤等が挙げられる。
上記酸化防止剤の中でも、ヒンダードフェノール系酸化防止剤、硫黄系酸化防止剤、リン系酸化防止剤、およびラクトン系酸化防止剤よりなる群から選ばれる少なくとも１種以上のものであるのが好ましい。特に、ヒンダードフェノール系酸化防止剤としては、ペンタエリスリトールテトラキス［３−（３，５−ジ−ｔｅｒｔ−ブチル−４−ヒドロキシフェニル）プロピオネート］、リン系酸化防止剤としては、トリス（２，４−ジ−ｔｅｒｔ−ブチルフェニル）フォスファイト、ラクトン系酸化防止剤としては、３−ヒドロキシ−５，７−ジ−ｔｅｒｔ−ブチル−フラン−２−オンとｏ−キシレンの反応生成物が好ましい。
上記酸化防止剤は、本発明に係る有機重合体微粒子中に約１０ｐｐｍ以上含まれていることが好ましく、より好ましくは１５ｐｐｍ以上であり、より好ましくは５０ｐｐｍ以上である。酸化防止剤の含有量が少なすぎる場合には、耐熱性向上の効果が得られ難い場合がある。上限は特に限定されないが、５％以下であるのが好ましく、より好ましくは３％以下である。
２．有機重合体微粒子の製造方法
本発明の有機重合体微粒子の製造方法では、ニトロキシルラジカル化合物存在下、ビニル系単量体を懸濁重合する。本発明の有機重合体微粒子の製造方法では、ニトロキシルラジカル化合物の存在下で反応させることにより、副反応である乳化重合を抑制でき、微小粒子の発生を抑制できる。このため、耐熱性に優れた有機重合体微粒子を収率良く得ることができる。
ビニル系単量体としては、上記の単量体と好ましい態様を同じとする。また、単量体組成物に加えて、例えば、顔料、可塑剤、重合安定剤、蛍光増白剤、磁性粉、紫外線吸収剤、帯電防止剤、難燃剤等の添加剤、重合開始剤、分散安定剤、酸化防止剤等を加えてもよい。なお、重合反応は溶媒中で行うことが好ましいが、この場合、単量体組成物は予め調製したものを溶媒に投入してもよいし、各構成成分や添加剤等を別々に溶媒に投入し、溶媒中で混合してもよい。
重合溶媒としては、例えば、水；メタノール、エタノール、イソプロピルアルコール等のアルコール類；アセトン、メチルエチルケトン等のケトン類；トルエン、キシレン等の芳香族炭化水素類；酢酸エチル等のエステル類等の有機溶媒が使用できる。重合溶媒としては、水が好ましく使用できる。
懸濁重合とは、一般的には、単量体成分や添加剤を含有する単量体組成物を、重合溶媒に分散、懸濁させることにより得られた液滴懸濁体組成物を重合することにより、有機重合体微粒子が重合溶媒中に分散含有されてなる分散液を得る方法である。液滴懸濁体組成物を調製する際には、単量体組成物を重合溶媒中に懸濁させる手段として従来公知の分散、懸濁方法、装置を採用することができる。例えば、Ｔ．Ｋ．ホモミキサー、ラインミキサー［例えばエバラマイルダー（登録商標）］等の高速撹拌機が使用できる。
本発明の懸濁重合は、ニトロキシルラジカル化合物存在下で行われる。上記ニトロキシルラジカル化合物は重合反応開始時に含有されていればよく、液滴懸濁体組成物を重合反応させる前に上記ニトロキシルラジカル化合物を添加することが好ましい。ニトロキシルラジカル化合物としては、上記と好ましい態様を同じとする。
上記ニトロキシルラジカル化合物の添加量は、ビニル系単量体成分総量１００質量部に対して、０．０５質量部〜０．５質量部が好ましく、０．０８質量部〜０．３質量部がより好ましい。ニトロキシルラジカル化合物の添加量が０．０５質量部未満の場合、微小粒子の発生の抑制が不十分となりやすく、上記添加量が０．５質量部より多い場合、重合反応が阻害されるおそれがある。
上記単量体組成物の液滴の粒子径を制御し、安定化させるためには、液滴懸濁体組成物の調製時に、後述する分散安定剤を共存させることが好ましい。ここで、重合開始剤（後述する）は、重合反応時に懸濁体組成物中に存在していればよいが、液滴懸濁体組成物調製時に、単量体組成物相あるいは重合溶媒の相に分散、溶解させておくのが好ましく、特に、単量体組成物に予め溶解せしめておく態様が好ましい。重合反応は、撹拌下で行うことが好ましい。撹拌は、パドル翼、タービン翼、ブルーマージン翼、プロペラ翼等従来公知の撹拌翼を用いた撹拌を採用し得る。
したがって、懸濁重合は、以下の工程よりなるものであるのが好ましい。
（１）単量体成分に重合開始剤、酸化防止剤を分散、溶解することにより単量体組成物を調製する工程、
（２）分散安定剤（必要に応じて用いられる）を分散、溶解してなる溶媒中に、前記単量体組成物を懸濁させて液滴懸濁体組成物を調製する工程、
（３）重合反応の開始直前にニトロキシルラジカル化合物を添加する工程、
（４）前記液滴懸濁体組成物の重合反応を開始させ（加熱するなどにより）、液滴状の単量体組成物を重合せしめ、重合体微粒子が溶媒中に分散含有されてなる分散液を調製する工程。
酸化防止剤としては上述のものが用いられるが、本発明の製造方法は、酸化防止剤の存在下で、上述の単量体成分をラジカル重合させるものであるため、酸化防止剤は、上記単量体成分や重合溶媒に溶解するものであるのが好ましい。酸化防止剤の配合量は、単量体成分総量に対して０．０１（１００ｐｐｍ）〜５質量％とするのが好ましい。より好ましくは０．０５（５００ｐｐｍ）〜３質量％であり、さらに好ましくは０．１〜１質量％である。なお、酸化防止剤として、硫黄系酸化防止剤を単独で用いる場合、硫黄系の酸化防止剤と他の酸化防止剤とを併用する場合のいずれの場合も、上記配合量の範囲とするのが好ましい。
重合反応には、重合開始剤を用いてもよく、また、放射線の照射や、熱を加えて重合を開始させる方法を採用してもよい。上記重合開始剤としては、通常、ラジカル重合に用いられるものはいずれも使用可能であり、例えば、過酸化物系開始剤や、アゾ系開始剤等が使用可能である。上記過酸化物系開始剤としては、過酸化ベンゾイル、過酸化ラウロイル、過酸化オクタノイル、オルソクロロ過酸化ベンゾイル、オルソメトキシ過酸化ベンゾイル等が挙げられる。アゾ系開始剤としては、ジメチル−２，２’−アゾビスイソブチレート、２，２’−アゾビスイソブチロニトリル、２，２’−アゾビス（２，４−ジメチルバレロニトリル）、２，２’−アゾビス（２，３−ジメチルブチロニトリル）等が挙げられる。これらの重合開始剤は、ビニル系単量体成分１００質量部に対して、０．０１質量部〜２０質量部（より好ましくは０．１質量部〜１０質量部）使用するのが好ましい。
また、重合反応時には、重合反応を安定に進めるため、分散安定剤（乳化剤）を使用しても良い。上記分散安定剤としては、ポリビニルアルコール、ゼラチン、ポリアクリル酸ナトリウム、ポリメタクリル酸ナトリウム等の水溶性高分子；ラウリル硫酸ナトリウム、ポリオキシエチレンアルキルフェニルエーテル硫酸エステル塩（例えば、ポリオキシエチレンジスチリルフェニルエーテル硫酸エステルアンモニウム）等のアニオン性界面活性剤；アルキルアミン塩、第四級アンモニウム塩等のカチオン性界面活性剤；ラウリルジメチルアミンオキサイド等の両性イオン性界面活性剤；ポリオキシエチレンアルキルエーテル等のノニオン性界面活性剤、その他アルギン酸塩、ゼイン、カゼイン、硫酸バリウム、硫酸カルシウム、炭酸バリウム、炭酸マグネシウム、リン酸カルシウム、タルク、粘土、ケイソウ土、ベントナイト、水酸化チタン、水酸化トリウム、金属酸化物粉末等が用いられる。
上記分散安定剤は、所望する有機重合体微粒子のサイズに応じてその使用量を適宜調整すればよい。例えば、平均粒子径１μｍ〜２０μｍの有機重合体微粒子を得たい場合であれば、ビニル系単量体成分１００質量部に対して０．０１質量部〜１０質量部（より好ましくは０．０５質量部〜５質量部、さらに好ましくは１質量部〜２質量部）である。
重合温度は、６０℃〜１００℃（より好ましくは６５℃〜９５℃、さらに好ましくは７０℃〜９０℃）が好ましく、重合反応は２時間〜７時間（より好ましくは２．５時間〜５時間であり、さらに好ましくは３時間〜４．５時間）が好ましい。また、重合反応は、ｐＨ４〜ｐＨ１０の範囲で行うのが好ましい。
そして、重合反応により得られた有機重合体微粒子が重合溶媒中に分散含有されてなる分散液を固液分離することにより有機重合体微粒子が得られる。固液分離方法としては、例えば、ろ過、遠心分離等が挙げられる。
また、固液分離する際には、凝集剤を用いてもよい。凝集剤としては、塩化ナトリウム、塩化マグネシウム、塩化カルシウム、硫酸ナトリウム、硫酸アルミニウム、硫酸亜鉛、硫酸マグネシウム、炭酸水素ナトリウム、炭酸ナトリウム、塩化アンモニウム、カリミョウバン等の金属塩類；硫酸、塩酸、リン酸、硝酸、炭酸、酢酸等の酸類；メタノール、エタノール等のアルコール類等が挙げられる。これらの凝集剤は単独で使用してもよいし、２種以上を併用してもよい。
上記凝集剤の添加量は特に限定されないが、分散液中の有機重合体微粒子１００質量部に対して、０．０５質量部〜１０質量部である。凝集に必要な時間は短く、通常は０．１分〜２時間の範囲で凝集が起こる。そのため、急激な凝集剤の添加は撹拌不能を起こす場合があるので好ましくなく、分散液への凝集剤は徐々に添加することが好ましい。また、凝集剤を添加する際の分散液の温度は３０℃〜１００℃が好ましい。
３．用途
本発明の有機重合体微粒子は、従来の粒子に比べて、微小粒子が少なく、例えば２３０〜２８０℃における重量減少率が小さく、耐熱性に優れる。従って、本発明の有機重合体微粒子は、窒素雰囲気下等の非酸化性雰囲気中で樹脂に対して溶融混合した場合に分解物を発生し難く、樹脂の着色や残留気泡等を生じにくいため、樹脂用添加剤として好適に使用できる。本発明の有機重合体微粒子を添加する樹脂としては、例えば、熱可塑性樹脂、好ましくはポリエステル樹脂、ポリオレフィン樹脂、ポリアミド樹脂、ポリウレタン樹脂、（メタ）アクリル樹脂、ポリカーボネート樹脂、ポリスチレン樹脂等が挙げられる。これらの中でも、比較的融点が高く、溶融混合を高い温度で行う必要があるポリエステル樹脂の添加剤として本発明の有機重合体微粒子を用いると、より本発明の効果が発揮される。
樹脂用添加剤の中でも、本発明の有機重合体微粒子は耐熱性に優れ、さらに着色が抑えられ（無色性に優れ）、組成によって有機重合体微粒子の屈折率を比較的広範囲に制御できることから樹脂用アンチブロッキング剤、光拡散剤として有用である。本発明の有機重合体微粒子を樹脂用添加剤として使用する場合、有機重合体微粒子を単独で使用してもよいし、他の成分と混合して用いてもよい。
４．マスターバッチ
上述したように、本発明の有機重合体微粒子は樹脂用添加剤として有用である。また、本発明の有機重合体微粒子は耐熱性に優れるため、溶融加工温度を高くすることができ、より低い溶融粘度での混合が可能となる。そのため、樹脂に対する有機重合体微粒子の配合量を高くしても、有機重合体微粒子を均一に分散させやすい。よって、本発明の有機重合体微粒子と樹脂とを含むマスターバッチも好ましい態様である。
マスターバッチに用いられる樹脂としては、好ましくは熱可塑性樹脂、より好ましくはポリエステル樹脂、ポリオレフィン樹脂、ポリアミド樹脂、ポリウレタン樹脂、（メタ）アクリル樹脂、ポリカーボネート樹脂、ポリスチレン樹脂等が挙げられる。これらの中でも、比較的融点が高く、溶融混合を高い温度で行う必要があるポリエステル樹脂の添加剤として本発明の有機重合体微粒子を用いると、より本発明の効果が発揮される。そのため、本発明の有機重合体微粒子を含有するポリエステル用添加剤とポリエステル樹脂とを含有するマスターバッチは本発明の好適態様である。
上記ポリエステル樹脂としては、特に限定されず、例えば、ポリエチレンテレフタレート、ポリトリメチレンテレフタレート、ポリテトラメチレンテレフタレート、ポリシクロヘキシレンジメチレンテレフタレート、ポリエチレン−２，６−ナフタレート、ポリテトラメチレン−２，６−ナフタレート等の芳香族ポリエステル樹脂が好ましい。これらは単独で使用してもよいし、２種以上を併用してもよい。これらの中でも、ポリエチレンテレフタレート樹脂が好ましい。
マスターバッチにおける有機重合体微粒子の含有量は、特に限定されないが、マスターバッチ中の樹脂１００質量部に対して、０．１質量部以上が好ましく、より好ましくは１質量部以上、さらに好ましくは５質量部以上であり、４００質量部以下が好ましく、より好ましくは２００質量部以下、さらに好ましくは１００質量部以下、一層好ましくは８０質量部以下である。
本発明の有機重合体微粒子を含有するマスターバッチを調製する方法としては、樹脂を合成する重合段階に有機重合体微粒子を添加混合する方法；重合後の樹脂に対してエクストルーダー等を用いて溶融混合する方法；樹脂を溶剤に溶解した状態で有機重合体微粒子を添加混合する方法等が採用できる。これらの中でも、溶融混合する方法は、本発明の有機重合体微粒子を用いる効果が顕著に発揮されるとともに、有機重合体微粒子を高濃度に分散含有された樹脂組成物を製造しやすいため、マスターバッチの製造に好適である。
樹脂を合成する重合段階で混合する方法としては、例えば、ポリエチレンテレフタレート（ＰＥＴ）やポリエチレンナフタレート（ＰＥＮ）等のポリエステル樹脂に添加する場合、エチレングリコール等のグリコール成分とジカルボン酸（エステル）成分との重合反応時に、有機重合体微粒子を一方の成分（好適にはグリコール成分）に分散させておき、有機重合体微粒子存在下で重合反応を行う方法が挙げられる。
溶融混練する方法としては、例えば、粉末あるいはペレット状のポリエステル樹脂と、有機重合体微粒子（粉体あるいは溶剤に分散させた形態）を混合し、撹拌しながらポリエステル樹脂を溶融させて混合処理する方法；ポリエステル樹脂を溶融させた状態で有機重合体微粒子（粉体あるいは溶剤に分散させた形態）を混合する方法；等が挙げられる。
調製されたマスターバッチは、通常、粉末状あるいはペレット状に加工される。そして、マスターバッチを、このマスターバッチに含まれる樹脂と同様の樹脂に添加し、溶融混合して樹脂組成物が調製される。本発明の有機重合体微粒子を添加剤として用いることで、着色や気泡の発生の抑制された樹脂組成物が得られる。
５．樹脂組成物
本発明の有機重合体微粒子と樹脂とを含む樹脂組成物も好ましい態様である。本発明の有機重合体微粒子は、窒素雰囲気下等の非酸化性雰囲気中で樹脂に対して溶融混合した場合に分解物を発生しにくいため、着色や残留気泡等が抑制された樹脂組成物が得られる。
また、本発明の有機重合体微粒子は、樹脂組成物を加熱成型する際にも、分解物を発生しにくいため、着色や残留気泡等が抑制された樹脂成型体が得られる。また、樹脂への分散性が良いため、ヘーズの低い樹脂成型体、例えばフィルムなど、が得られる。
樹脂組成物は、上記マスターバッチと樹脂とを混合して調製してもよいし、本発明の有機重合体微粒子と樹脂を混合して、直接、樹脂組成物を調製してもよい。
樹脂組成物を、フィルム等に成型する方法としては、射出成形、押出成形等の加熱成型；樹脂組成物を溶剤で希釈して、液状の樹脂組成物を基材となる支持体に塗布する方法；等が挙げられる。
上記ポリエステル樹脂用添加剤とポリエステル樹脂とを混合する方法は特に限定されず、ポリエステル樹脂の重合段階で添加してもよいし、重合後のポリエステル樹脂に対してエクストルーダー等を用いて溶融混合してもよい。1. Organic polymer fine particles
The organic polymer fine particle of the present invention contains a polymer containing a constitutional unit derived from a vinyl monomer and a nitroxyl radical compound, and the CV value (coefficient of variation) of the particle diameter is 15% or more.
1-1 Polymer
The polymer contained in the organic polymer fine particles of the present invention contains a constitutional unit derived from a vinyl-based monomer. The polymer containing the structural unit derived from a vinyl-type monomer can be obtained by polymerizing a vinyl-type monomer.
1-1-1 Vinyl monomer
Specific examples of the vinyl monomer include (meth) acrylic monomers, styrene monomers, and maleimide monomers. In the present application, (meth) acrylic monomers refer to acrylic monomers, methacrylic monomers and mixtures thereof, and (meth) acrylic acid refers to acrylic acid, methacrylic acid and the like. Indicates a mixture.
The vinyl-based monomer preferably contains a monomer of any of the above-mentioned styrene-based monomer, maleimide-based monomer, and (meth) acrylic-based monomer, and the above-mentioned styrene-based monomer, It is more preferable to contain any two or more of a maleimide-based monomer and a (meth) acrylic-based monomer.
1-1-1-1 (Meth) acrylic monomer
The (meth) acrylic monomers include (A) monofunctional (meth) acrylate monomers, (B) polyfunctional (meth) acrylate monomers, (meth) acrylonitrile, etc. It can.
In the present specification, the (A) monofunctional (meth) acrylate monomer is a monomer having only one (meth) acryloyl group in the molecule. (A) The monofunctional (meth) acrylate monomer includes, in addition to the above (meth) acryloyl group, for example, a radical polymerizable group such as vinyl group, carboxyl group, hydroxy group, alkoxy group, isocyanurate group, etc. As such, it may have a condensable reactive group capable of forming an ester bond or the like when a group serving as a reaction (binding) partner is present in another monomer. Such condensable reactive groups may also act as "polymerizable groups".
Examples of the (A) monofunctional (meth) acrylate monomer include (meth) acrylic acid; methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate and n-butyl (meth) acrylate. , Isobutyl (meth) acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, octyl (meth) acrylate, nonyl (meth) acrylate, decyl (meth) acrylate, dodecyl (meth) acrylate, stearyl Alkyl (meth) acrylates such as (meth) acrylate and 2-ethylhexyl (meth) acrylate; cyclopropyl (meth) acrylate, cyclopentyl (meth) acrylate, cyclohexyl (meth) acrylate, cyclooctyl Cycloalkyl (meth) acrylates such as meta) acrylate, cycloundecyl (meth) acrylate, cyclododecyl (meth) acrylate, isobornyl (meth) acrylate, 4-t-butylcyclohexyl (meth) acrylate; 2-hydroxyethyl (meth) acrylate Hydroxyalkyl (meth) acrylates such as meta) acrylate, 2-hydroxypropyl (meth) acrylate and 2-hydroxybutyl (meth) acrylate; phenyl (meth) acrylate, benzyl (meth) acrylate, tolyl (meth) acrylate, phenethyl Aromatic ring-containing (meth) acrylates such as (meth) acrylate; and allyl (meth) acrylates such as allyl (meth) acrylate. These (A) monofunctional (meth) acrylate monomers may be used alone or in combination of two or more. Among these, alkyl (meth) acrylates are preferable, and methyl (meth) acrylate is particularly preferable.
The content of the (A) monofunctional (meth) acrylate monomer is preferably 0 to 40 parts by mass, and more preferably 0 to 30 parts by mass, in 100 parts by mass of the vinyl monomer.
The (B) polyfunctional (meth) acrylate monomer is a monomer having two or more (meth) acryloyl groups in the molecule. The (B) polyfunctional (meth) acrylate monomer is, like the (A) monofunctional (meth) acrylate monomer, a radically polymerizable group such as a vinyl group in addition to the (meth) acryloyl group. In addition to the above, such as carboxyl group, hydroxy group, alkoxy group, isocyanurate group, etc., it has a condensable reactive group capable of forming an ester bond etc. when a group serving as a reaction (bonding) partner is present in another monomer. It may be done.
Examples of the (B) polyfunctional (meth) acrylate monomers include ethylene glycol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, and 1,6-hexanediol di (meth) acrylate. Alkanediol di (meth) acrylates such as 1,9-nonanediol di (meth) acrylate, 1,10-decanediol di (meth) acrylate, 1,3-butylene di (meth) acrylate; diethylene glycol di (meth) acrylate Triethylene glycol di (meth) acrylate, decaethylene glycol di (meth) acrylate, pentadecaethylene glycol di (meth) acrylate, pentaconta ethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate Di (meth) acrylates such as polyalkylene glycol di (meth) acrylates such as polypropylene glycol di (meth) acrylate and polytetramethylene glycol di (meth) acrylate; tri (meth) acrylates such as trimethylolpropane tri (meth) acrylate Acrylates; tetra (meth) acrylates such as pentaerythritol tetra (meth) acrylate; hexa (meth) acrylates such as dipentaerythritol hexa (meth) acrylate; tri (acryloyloxyethyl) isocyanurate, tri (methacryloyloxyethyl) ) Isocyanurate, alkylene oxide-added tri (acryloyloxyethyl) isocyanurate, alkylene oxide-added tri (methacryloyloxyethyl) isocyanurate Polyfunctional (meth) acryloyl group-containing isocyanurates of; polyfunctional allyl group-containing isocyanurate such as triallyl isocyanurate. These (B) polyfunctional (meth) acrylate monomers may be used alone or in combination of two or more. Among these, one having two or more (meth) acryloyl groups in one molecule is preferable, and one having three or more (meth) acryloyl groups in one molecule is more preferable. Further, among the (B) polyfunctional (meth) acrylate monomers, alkanediol di (meth) acrylates and tri (meth) acrylates are preferable, and more preferably ethylene glycol di (meth) acrylate and trimethylolpropane triol. (Meth) acrylate.
1-1-1-2 Styrenic monomer
Examples of styrene-based monomers include styrene; alkylstyrenes such as o-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene, p-tert-butylstyrene and the like; p-phenylstyrene and the like Aromatic ring-containing styrenes; Halogen-containing styrenes such as o-chlorostyrene, m-chlorostyrene, p-chlorostyrene, etc .; Hydroxyl-containing styrenes such as p-hydroxystyrene; Alkoxystyrenes such as p-methoxystyrene, etc. Can be mentioned. These styrenic monomers may be used alone or in combination of two or more. Among these, styrene is preferred.
The content of the styrene-based monomer is preferably 1 to 95 parts by mass, more preferably 30 to 90 parts by mass, and still more preferably 50 to 70 parts by mass in 100 parts by mass of the vinyl-based monomer. When the content of the styrene-based monomer is 1 part by mass or more, the heat resistance of the organic polymer fine particles is further enhanced, and the affinity to the aromatic polyester resin and the dispersibility also tend to be improved. When the content of the styrene-based monomer exceeds 95 parts by mass, the crosslinkability tends to be low.
1-1-1-3 maleimide monomer
In the organic polymer fine particles of the present invention, the vinyl-based monomer preferably contains a maleimide-based monomer. By including the maleimide-based monomer, the thermal decomposition initiation temperature of the organic polymer fine particles in the non-oxidizing atmosphere can be further increased. As the maleimide monomer, those represented by the general formula (I) can be mentioned.

[In the formula (I), R ¹¹ And R ¹² Each independently represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 15 carbon atoms, an aryl group having 1 to 15 carbon atoms, or an aralkyl group having 1 to 15 carbon atoms; ¹³ Represents an alkyl group having 1 to 15 carbon atoms, an aryl group having 1 to 15 carbon atoms, or an aralkyl group having 1 to 15 carbon atoms. ]
R ¹¹ ~ R ¹³ As the alkyl group represented by the following, methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group, tridecyl group, tetradecyl group And a linear alkyl group such as pentadecyl group; a branched alkyl group such as isopropyl group, isobutyl group and tert-butyl group; and a cyclic alkyl group such as cyclopropyl group, cyclobutyl group, cyclopentyl group and cyclohexyl group. R ¹¹ ~ R ¹³ As an aryl group represented by these, a phenyl group, a naphthyl group, etc. are mentioned. In addition, the hydrogen atom which these alkyl groups and aryl groups have may be further substituted by an alkyl group, an aryl group, a halogen atom, a nitro group, etc. R ¹¹ ~ R ¹³ As an aralkyl group represented by these, a benzyl group, a phenethyl group, 3-phenylpropyl group etc. are mentioned.
Specific examples of the above maleimide-based monomer include, for example, maleimide; N-alkyl such as N-methyl maleimide, N-ethyl maleimide, N-propyl maleimide, N-butyl maleimide, N-cyclohexyl maleimide, N-lauryl maleimide and the like Maleimide; N-phenyl maleimide, N- (2-chlorophenyl) maleimide, N- (3-chlorophenyl) maleimide, N- (4-chlorophenyl) maleimide, N- (4-bromophenyl) maleimide, N- (2, 4 , 6-Trichlorophenyl) maleimide, N- (2,4,6-tribromo) maleimide, N- (2-nitrophenyl) maleimide, N- (3-nitrophenyl) maleimide, N- (4-nitrophenyl) maleimide , N- (2,4-dinitrophenyl) maleimide, N- (2- (2-) N-aryl maleimides such as droxyphenyl) maleimide, N- (3-hydroxyphenyl) maleimide, N- (4-hydroxyphenyl) maleimide, N- (4-phenylphenyl) maleimide, N-naphthyl maleimide, etc .; 2-Methylphenyl) maleimide, N- (3-methylphenyl) maleimide, N- (4-methylphenyl) maleimide, N- (2-butylphenyl) maleimide, N- (3-butylphenyl) maleimide, N- ( N-alkyl aryl maleimide such as 4-butylphenyl) maleimide, N- (2, 6-dimethylphenyl) maleimide; N- (2-methoxyphenyl) maleimide, N- (3-methoxyphenyl) maleimide, N- (4 -Methoxyphenyl) maleimide, N- (4-ethoxyphenyl) malei Aralkyl maleimide benzyl maleimide; aryloxy arylmaleimide N-(4-phenyloxy-phenyl) maleimide; de, N-(2-methoxy-4-chlorophenyl) alkoxyaryl maleimides such as maleimide and the like. These maleimide monomers may be used alone or in combination of two or more. Among these, N-alkyl maleimide (preferably N-cyclic alkyl maleimide) and N-aryl maleimide are preferable, and N-cyclohexyl maleimide and N-phenyl maleimide are particularly preferable.
The content of the maleimide monomer is preferably 0 to 40 parts by mass, more preferably 0 to 25 parts by mass, and still more preferably 1 to 25 parts by mass with respect to 100 parts by mass of the vinyl monomer. When the content of the maleimide monomer is 1 part by mass or more, the thermal decomposition initiation temperature increase effect by the maleimide monomer can be sufficiently obtained, and when it is 30 parts by mass or less, organic polymer fine particles Improves the colorlessness (whiteness) of
1-1-1-4 Crosslinking agent
The organic polymer fine particle of the present invention may contain a crosslinking agent as a component as the above-mentioned vinyl monomer. Among the above (meth) acrylic monomers, one having two or more polymerizable groups can be a crosslinking agent. Other than these, aromatic divinyl compounds such as divinylbenzene, divinylnaphthalene and derivatives thereof; N, N-divinylaniline, divinyl sulfide, divinyl sulfonic acid; divinyl ether, ethylene glycol divinyl ether, diethylene glycol divinyl ether, polyethylene glycol di Vinyl ether, propylene glycol divinyl ether, butylene glycol divinyl ether, hexanediol divinyl ether, bisphenol A alkylene oxide divinyl ether, bisphenol F alkylene oxide divinyl ether, trimethylolpropane trivinyl ether, ditrimethylolpropane tetravinyl ether, glycerin trivinyl ether, pentaerythritol tetramer Vinyl ether, Pentaerythritol pentavinyl ether, dipentaerythritol hexavinyl ether, ethylene oxide adducted trimethylolpropane trivinyl ether, ethylene oxide adducted ditrimethylolpropane tetravinyl ether, ethylene oxide adducted pentaerythritol tetravinyl ether, ethylene oxide adducted dipentaerythritol hexavinyl ether, etc. Multifunctional vinyl ethers such as ethylene glycol Diallyl ether, diethylene glycol diallyl ether, polyethylene glycol diallyl ether, propylene glycol diallyl ether, butylene glycol diallyl ether, hexanediol diallyl ether, bisphenol A alkylene oxide diallyl ether, bisphenol F alkylene Oxide diallyl ether, trimethylolpropane triallyl ether, ditrimethylolpropane tetraallyl ether, glycerin triallyl ether, pentaerythritol tetraallyl ether, dipentaerythritol pentaallyl ether, dipentaerythritol hexaallyl ether, ethylene oxide adducted trimethylolpropane triallyl Ethers, polyfunctional ethylene ethers such as ethylene oxide adduct ditrimethylolpropane tetraallyl ether, ethylene oxide adduct pentaerythritol tetraallyl ether, ethylene oxide adduct dipentaerythritol hexaallyl ether can be used. As a crosslinking agent, these may be used independently and may use 2 or more types together. Moreover, as a thing used as a crosslinking agent among (meth) acrylic-type monomers, said (B) polyfunctional (meth) acrylate-type monomer is preferable.
The content of the crosslinking agent is preferably 0.1 to 50 parts by mass, more preferably 1 to 20 parts by mass, and still more preferably 2 to 15 parts by mass with respect to 100 parts by mass of the vinyl monomer. When the content of the crosslinking agent is 50 parts by mass or less, the particles are more excellent in mass reduction start temperature and thermal decomposition start temperature. The reason is that if the content is 50 parts by mass or less, the double bond which is likely to be left due to the cross-linking agent in the polymerization reaction at the time of production becomes difficult to remain, so starting from the remaining double bond It is considered that the decomposition is suppressed. In addition, when the content is 0.1 parts by mass or more, deformation of the organic polymer fine particles due to heating at the time of melting or processing is suppressed when preparing the resin composition or processing the resin composition. Ru. In the present specification, the descriptions of A to B have the same meanings as A or more and B or less including A and B.
1-1-1-5 Other monomer
The organic polymer fine particles of the present invention may be the above (meth) acrylic monomers, the above styrenic monomers, the above maleimide monomers, and the above crosslinking agents, as long as the effects of the present invention are not impaired. Other different monomers may be included as components. When other monomers are used, the amount thereof used is preferably 20 parts by mass or less, and more preferably 10 parts by mass or less in 100 parts by mass of all vinyl monomers.
1-2 nitroxyl radical compound
The organic polymer fine particle of the present invention contains a nitroxyl radical compound. In the organic polymer fine particle of the present invention, the heat resistance is improved by containing the above-mentioned nitroxyl radical compound. Examples of the nitroxyl radical compound include 4-hydroxy-2,2,6,6-tetramethylpiperidin-1-oxyl, 2,2,6,6-tetramethylpiperidin-1-oxyl, 4-benzoyloxy Examples thereof include 2,2,6,6-tetramethylpiperidin-1-oxyl, and 5,5-dimethyl-1-pyrroline N oxide, and one or more of these can be used. Among the above nitroxyl radical compounds, 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl (4H-TEMPO) represented by the following formula (II) is preferable.

The content of the nitroxyl radical compound is preferably 10 to 1000 ppm, more preferably 50 to 700 ppm, and still more preferably 70 to 500 ppm, based on the total mass of the vinyl-based monomer component. When the content of the nitroxyl radical compound is less than 10 ppm, it is difficult to obtain sufficient heat resistance, and when it exceeds 1000 ppm, the polymerizability may be insufficient.
1-3 Particle size
The average particle size (volume average particle size) of the organic polymer fine particles according to the present invention is preferably 0.1 to 100 μm, more preferably 0.3 to 50 μm, and still more preferably 0.5 to 30 μm. . If the average particle size is smaller than 0.1 μm, a large amount of addition may be required because the blocking resistance effect and the slippage improving effect may not be sufficiently exhibited, and the mechanical strength of the film may be impaired. On the other hand, when the average particle diameter is larger than 100 μm, the particles are easily detached from the film, which may cause a decrease in mechanical strength. In the present specification, the "average particle size" refers to the "volume average particle size".
1-4 CV value of particle diameter (coefficient of variation)
The organic polymer fine particles of the present invention have a particle diameter CV value (variation coefficient) of 15% or more, preferably 15 to 70%, more preferably 20 to 65%, and still more preferably 25 to 60%. In order to obtain particles having a CV value of less than 15%, in the case of suspension polymerization, it is necessary to carry out a classification step, which increases the production cost. When the CV value is large, the amount of coarse particles is large, the particles are easily detached from the film, and the mechanical strength tends to decrease, which is not preferable.
The CV value (coefficient of variation) of the particle diameter can be calculated according to the following equation.
Particle size CV value (%) = 100 × (standard deviation of particle size / volume average particle size)
The standard deviation of particle diameter is a numerical value obtained from volume-based particle diameter distribution.
In the organic polymer fine particles of the present invention, the CV value (coefficient of variation) of the particle diameter is 15% or more because the particles are produced by suspension polymerization.
1-5 Particle shape
The fine particles of the organic polymer according to the present invention include not only spherical particles but also porous particles and irregularly shaped particles having many irregularities on the surface of the particles. When it is used as an antiblocking agent for a resin film, it is preferable that the contact surface between the film and the organic polymer particles is large, from the viewpoint of suppressing voids and dropping off of particles when the film is stretched. In order to increase the surface area of the organic polymer particles, shapes such as porous particles and irregularly shaped particles may be required rather than true spherical particles.
1-6 Antioxidants
The organic polymer fine particles according to the present invention may contain an antioxidant. By including the antioxidant, the heat resistance can be further improved. Examples of the antioxidant include hindered phenol type antioxidants, sulfur type antioxidants, phosphorus type antioxidants, lactone type antioxidants, hydroxylamine type antioxidants, vitamin E type antioxidants, etc. . The above hindered phenol-based antioxidant means one having a para-substituted 2,6-di-tert-butylphenol structure in the structure of the antioxidant, and the sulfur-based antioxidant is a sulfur element And those having an antioxidant function, those having a phosphorus-based antioxidant mean those having a phosphorus atom in the structure thereof, and the lactone-based antioxidants those having a cyclic ester structure. These structures may contain 2 or more types simultaneously, and in this case, in this specification, each antioxidant is classified according to the portion that exerts the antioxidant effect.
Thiodiethylene bis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], 4,6-bis (dodecyl) as a sulfur-based antioxidant known in the prior art as having an aromatic ring Thiomethyl) -o-cresol, 4,6-bis (octylthiomethyl) -o-cresol, 2,6-di-tert-butyl-4- (4,6-bis (octylthio) -1,3,5 Pentaerythritolyl tetrakis (3-laurylthiopropionate), didodecyl-3,3'-thiodipropionate, dioctadecyl-3, and the like as those having no aromatic ring such as -triazin-2-ylamino) phenol; 3'-thiodipropionate, dimyristyl-3, 3-thiopropionate, ditridecyl-3, 3-thiodipropionate and the like. . Among these, thioether compounds (having a C-SC bond) are preferable, and pentaerythrityl tetrakis (3-lauryl thiopropionate) is particularly preferable. These sulfur-based antioxidants are preferable because they can be obtained inexpensively.
Moreover, the compound (1) which has a structural unit represented by following formula (1) can also be preferably used as a sulfur type antioxidant concerning this invention.

In the formula (1), n means an integer of 1 to 5 (preferably n = 2).
Among the compounds (1), compounds having two or more structural units represented by the above-mentioned formula (1) in the molecule are preferable. More preferably, it is a compound having 2 to 4 structural units represented by the above-mentioned formula (1) in the molecule, and it is particularly preferable to use 4 structural units represented by the above-mentioned formula (1) in the molecule It is a compound which it has.
Moreover, the compound (2) which has a structural unit represented by following formula (2) among the said compound (1) is preferable. More preferable as the compound (2) is a compound having 2 to 4 structural units represented by the following formula (2) in the molecule, and more preferably 4 structural units represented by the following formula (2) It is a compound which it has.

Here, n is an integer of 1 to 5 (preferably n = 2), and R ¹ Is at least one group selected from the group consisting of an alkyl group, an aryl group, an aralkyl group and an alkenyl group, and R ¹ May have a substituent.
The alkyl group is preferably an alkyl group having 1 to 20 carbon atoms, more preferably 3 to 20, and still more preferably 6 to 18 because the effect of improving the heat resistance is high. For example, alkyl groups such as propyl, butyl, pentyl, hexyl, octyl, dodecyl (lauryl), tridecyl, myristyl, octadecyl (stearyl) and the like can be mentioned.
The aryl group may, for example, be a phenyl group, a hydroxyphenyl group, a tolyl group or an o-xylyl group. Among these, a phenyl group and a hydroxyphenyl group are preferable.
Examples of the aralkyl group include benzyl group, methylbenzyl group, phenethyl group, methylphenethyl group, phenylbenzyl group and naphthylmethyl group, and as the alkenyl group, vinyl group, allyl group, propenyl group, 1-butenyl group, 2-butenyl group etc. are mentioned.
Among these, an alkyl group and an aryl group are preferable, and an alkyl group is particularly preferable.
As said substituent, a hydroxyl group, an amino group, a carboxyl group, an alkyl group, an aryl group, an aralkyl group, an alkenyl group etc. are illustrated.
As a compound (2) which has four structural units represented by the said Formula (2), a pentaerythrityl tetrakis (3-alkyl thio propionate) compound is mentioned preferably, for example. Specifically, pentaerythrityl tetrakis (3-methylthiopropionate), pentaerythrityl tetrakis (3-ethylthiopropionate), pentaerythrityl tetrakis (3-propylthiopropionate), pentaerythrityl tetrakis (3-Butylthiopropionate), pentaerythrityltetrakis (3-hexylthiopropionate), pentaerythrityltetrakis (3-octylthiopropionate), pentaerythrityltetrakis (3-laurylthiopropionate) ), Pentaerythrityl tetrakis (3-tridecylthiopropionate), pentaerythrityl tetrakis (3-myristyl thiopropionate), pentaerythrityl tetrakis (3-stearylthiopropionate), pentaerythrithiol (3-stearylthiopropionate) Such Rutetorakisu (3-phenyl thiopropionate) are exemplified. Among them, compounds having an alkyl group having 3 to 20 carbon atoms are preferable, and more preferable are compounds having 6 to 18 carbon atoms of the alkyl group, and particularly preferably 12 to 18 carbon atoms of the alkyl group.
In particular, pentaerythrityl tetrakis (3-laurylthiopropionate) having an alkyl group having 12 carbon atoms is preferable because it is industrially available.
Further, among the compounds (1), a compound (3) having a structural unit represented by the following formula (3) is also preferably used as a sulfur-based antioxidant according to the present invention.

In Formula (3), n is an integer of 1 to 5 (preferably n = 2).
Among the compounds (3) having a structural unit represented by the above formula (3), a compound having a structural unit represented by the following formula (4) is more preferable.

n is an integer of 1 to 5 (preferably n = 2).
In the formula (4), R ² And R ³ Each independently represents at least one group selected from the group consisting of an alkyl group, an aryl group, an aralkyl group and an alkenyl group, and R ² And R ³ May have a substituent. In addition, as the alkyl group, the aryl group, the aralkyl group and the alkenyl group, R in the above-mentioned compound (2) is ¹ The same thing as the case of can be illustrated preferably. In addition, R ² And R ³ Preferred as is an alkyl group or an aryl group, and particularly preferred is an alkyl group.
Examples of the substituent include an alkyl group, an aryl group, an aralkyl group, an alkenyl group, a hydroxyl group, an amino group and a carboxyl group.
As a compound (3) which has a structural unit represented by Formula (4), a dialkyl 3,3'- thiodipropionate compound is mentioned preferably, for example. Specifically, dimethyl-3,3'-thiodipropionate, diethyl-3,3'-thiodipropionate, dipropyl-3,3'-thiodipropionate, dibutyl-3,3'-thiodipro Peonate, dihexyl-3,3'-thiodipropionate, dioctyl-3,3'-thiodipropionate, didodecyl-3,3'-thiodipropionate (dilauryl-3,3'-thiodipropionate) ), Dimyristyl-3,3'-thiodipropionate, ditridecyl-3,3'-thiodipropionate, dioctadecyl-3,3'-thiodipropionate (distearyl-3,3'-thiodipropio) Nat)) and the like. Among these, those having an alkyl group having 3 to 20 carbon atoms are preferable, more preferably a compound having 6 to 18 carbon atoms in the alkyl group, and still more preferably a compound having 12 to 18 carbon atoms in the alkyl group.
In particular, didodecyl-3,3'-thiodipropionate having an alkyl group having 12 to 18 carbon atoms, dimyristyl-3,3'-thiodipropionate, ditridecyl-3,3'-thiodipropionate, dioctadecyl The 3,3'-thiodipropionate is preferable because it is industrially easily available.
Specifically, pentaerythritol tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], octadecyl-3- (3,5-) as the above-mentioned hindered phenol-based antioxidant. Di-tert-butyl-1-hydroxyphenyl) propionate, N, N'-hexane-1,6-diylbis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionamide], benzenepropane Acid, 3,5-bis (1,1-dimethylethyl) -4-hydroxy, C7-C9 side chain alkyl ester, 3,3 ', 3'',5,5', 5 ''-hexa-tert- Butyl-a, a ′, a ′ ′-(mesitylene-2,4,6-tolyl) tri-p-cresol, calcium diethylbis [[[3,5-bis (1,1-dimethyl) Ethyl) -4-hydroxyphenyl] methyl] phosphonate], ethylenebis (oxyethylene) bis [3- (5-tert-butyl-4-hydroxy-m-tolyl) propionate], hexamethylene bis [3- (3,3, 5-di-tert-butyl-4-hydroxyphenyl) propionate], 1,3,5-tris (3,5-di-tert-butyl-4-hydroxybenzyl) -1,3,5-triazine-2, 4,6 (1H, 3H, 5H) -trione, 1,3,5-tris [(4-tert-butyl-3-hydroxy-2,6-xylyl) methyl] -1,3,5-triazine-2 , 4,6 (1H, 3H, 5H) -trione, the reaction product of N-phenylbenzenamine and 2,4,4-trimethylbenzene, diethyl [[3,5-bis (1,1) -Dimethylethyl) -4-hydroxyphenyl] methyl] phosphonate, 2,4-dimethyl-6- (1-methylpentadecyl) phenol, octadecyl-3- (3,5-tert-butyl-4-hydroxyphenyl) propionate 2 ', 3-bis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionyl] propionohydrazide and the like.
Examples of the above-mentioned phosphorus-based antioxidants include tris (2,4-di-tert-butylphenyl) phosphite, tris [2-[[2,4,8,10-tetra-tert-butyldibenzo [d, f] [1,3,2] dioxaphosphefin-6-yl] oxy] ethyl] amine, bis (2,4-di-tert-butylphenyl) pentaerythritol diphosphite, bis [2,4-bis ( 1,1-Dimethylethyl) -6-methylphenyl] ethyl ester phosphorous acid, tetrakis (2,4-di-tert-butylphenyl) [1,1-biphenyl] -4,4'-diyl bis phosphonite Etc.
Examples of the lactone antioxidant include the reaction product of 3-hydroxy-5,7-di-tert-butyl-furan-2-one and o-xylene (CAS No. 181314-48-7) and the like. .
In addition, as the antioxidant, hydroxylamine-based antioxidants such as oxidation products of alkylamines using the above-mentioned reduced tallow as a raw material; 3,4-dihydro-2,5,7,8-tetramethyl-2 And vitamin E-based antioxidants such as-(4,8,12-trimethyltridecyl) -2H-benzopyran-6-ol.
Among the above antioxidants, at least one selected from the group consisting of hindered phenol type antioxidants, sulfur type antioxidants, phosphorus type antioxidants, and lactone type antioxidants is preferable. . In particular, pentaerythritol tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] as a hindered phenol-based antioxidant, and tris (2,4) as a phosphorus-based antioxidant As the -di-tert-butylphenyl) phosphite, and the lactone antioxidant, a reaction product of 3-hydroxy-5,7-di-tert-butyl-furan-2-one and o-xylene is preferable.
The above-mentioned antioxidant is preferably contained in an amount of about 10 ppm or more, more preferably 15 ppm or more, and more preferably 50 ppm or more in the organic polymer fine particles according to the present invention. If the content of the antioxidant is too small, it may be difficult to obtain the effect of improving the heat resistance. The upper limit is not particularly limited, but is preferably 5% or less, more preferably 3% or less.
2. Method of producing organic polymer fine particles
In the method for producing organic polymer fine particles of the present invention, a vinyl monomer is suspension-polymerized in the presence of a nitroxyl radical compound. In the method for producing organic polymer fine particles of the present invention, by causing the reaction in the presence of the nitroxyl radical compound, it is possible to suppress the emulsion polymerization which is a side reaction, and to suppress the generation of fine particles. For this reason, organic polymer fine particles excellent in heat resistance can be obtained with a good yield.
As a vinyl-type monomer, let a preferable aspect be the same as said monomer. Also, in addition to the monomer composition, for example, additives such as pigments, plasticizers, polymerization stabilizers, fluorescent brightening agents, magnetic powders, ultraviolet absorbers, antistatic agents, flame retardants, polymerization initiators, dispersions Stabilizers, antioxidants and the like may be added. In addition, although it is preferable to carry out the polymerization reaction in a solvent, in this case, the monomer composition prepared in advance may be added to the solvent, or each component, additive, etc. may be separately added to the solvent. And may be mixed in a solvent.
Examples of the polymerization solvent include: water; alcohols such as methanol, ethanol and isopropyl alcohol; ketones such as acetone and methyl ethyl ketone; aromatic hydrocarbons such as toluene and xylene; organic solvents such as esters such as ethyl acetate It can be used. Water is preferably used as the polymerization solvent.
In the suspension polymerization, generally, a droplet suspension composition obtained by dispersing and suspending a monomer composition containing a monomer component and an additive in a polymerization solvent is polymerized. This is a method of obtaining a dispersion in which organic polymer fine particles are dispersed and contained in a polymerization solvent. When preparing the droplet suspension composition, conventionally known dispersion, suspension methods and devices can be adopted as a means for suspending the monomer composition in a polymerization solvent. For example, T.I. K. High speed stirrers such as homomixers, line mixers (eg Ebara Milder®) can be used.
The suspension polymerization of the present invention is carried out in the presence of a nitroxyl radical compound. The nitroxyl radical compound may be contained at the start of the polymerization reaction, and the nitroxyl radical compound is preferably added before the droplet suspension composition is polymerized. Preferred embodiments of the nitroxyl radical compound are the same as those described above.
The addition amount of the nitroxyl radical compound is preferably 0.05 parts by mass to 0.5 parts by mass, and 0.08 parts by mass to 0.3 parts by mass with respect to 100 parts by mass of the total amount of the vinyl-based monomer component. More preferable. When the addition amount of the nitroxyl radical compound is less than 0.05 parts by mass, the suppression of generation of the microparticles tends to be insufficient, and when the addition amount is more than 0.5 parts by mass, the polymerization reaction may be inhibited. is there.
In order to control and stabilize the particle diameter of the droplets of the monomer composition, it is preferable to coexist a dispersion stabilizer described later when preparing the droplet suspension composition. Here, the polymerization initiator (described later) may be present in the suspension composition at the time of the polymerization reaction, but at the time of preparation of the droplet suspension composition, it may be in the monomer composition phase or the polymerization solvent. It is preferable to disperse and dissolve in the phase, and in particular, an embodiment in which it is previously dissolved in the monomer composition is preferable. The polymerization reaction is preferably carried out under stirring. The stirring can be performed using a conventionally known stirring blade such as a paddle blade, a turbine blade, a blue margin blade, or a propeller blade.
Accordingly, suspension polymerization preferably comprises the following steps.
(1) preparing a monomer composition by dispersing and dissolving a polymerization initiator and an antioxidant in the monomer component,
(2) preparing a droplet suspension composition by suspending the monomer composition in a solvent obtained by dispersing and dissolving a dispersion stabilizer (which is optionally used);
(3) adding a nitroxyl radical compound immediately before the start of the polymerization reaction,
(4) A polymerization reaction of the droplet suspension composition is initiated (by heating or the like) to polymerize the monomer composition in the form of droplets, and the polymer fine particles are dispersed and contained in the solvent. A step of preparing a liquid.
Although the above-mentioned thing is used as an antioxidant, Since the manufacturing method of this invention radically polymerizes the above-mentioned monomer component in presence of antioxidant, the antioxidant is the said single-piece | unit, It is preferable to be soluble in the monomer component and the polymerization solvent. The blending amount of the antioxidant is preferably 0.01 (100 ppm) to 5% by mass with respect to the total amount of the monomer components. More preferably, it is 0.05 (500 ppm)-3 mass%, More preferably, it is 0.1-1 mass%. When a sulfur-based antioxidant is used alone as the antioxidant, the above-mentioned range of the compounding amount is used in any case where the sulfur-based antioxidant and the other antioxidant are used in combination. preferable.
For the polymerization reaction, a polymerization initiator may be used, or radiation irradiation or heat may be applied to initiate polymerization. As the above-mentioned polymerization initiator, any of those generally used for radical polymerization can be used. For example, peroxide initiators, azo initiators, etc. can be used. Examples of the above-mentioned peroxide initiator include benzoyl peroxide, lauroyl peroxide, octanoyl peroxide, benzoyl orthochlorobenzoyl peroxide, and benzoyl orthomethoxy peroxide. As an azo initiator, dimethyl-2,2'-azobisisobutyrate, 2,2'-azobisisobutyronitrile, 2,2'-azobis (2,4-dimethyl valeronitrile), 2 ,, 2'-azobis (2, 3- dimethyl butyronitrile) etc. are mentioned. It is preferable to use 0.01 to 20 parts by mass (more preferably 0.1 to 10 parts by mass) of these polymerization initiators with respect to 100 parts by mass of the vinyl monomer component.
At the time of polymerization reaction, a dispersion stabilizer (emulsifier) may be used in order to stably advance the polymerization reaction. Examples of the dispersion stabilizer include water-soluble polymers such as polyvinyl alcohol, gelatin, sodium polyacrylate and sodium polymethacrylate; sodium lauryl sulfate, polyoxyethylene alkylphenyl ether sulfate (eg, polyoxyethylene distyryl phenyl) Anionic surfactants such as ammonium ether sulfate ester); cationic surfactants such as alkylamine salt and quaternary ammonium salt; zwitterionic surfactants such as lauryldimethylamine oxide; etc. such as polyoxyethylene alkyl ether Nonionic surfactants, other alginates, zein, casein, barium sulfate, calcium sulfate, barium carbonate, magnesium carbonate, calcium phosphate, talc, clay, diatomaceous earth, bentonite, titanium hydroxide Thorium hydroxide, metal oxide powder or the like is used.
The amount of the dispersion stabilizer used may be appropriately adjusted according to the desired size of the organic polymer fine particles. For example, when it is desired to obtain organic polymer fine particles having an average particle diameter of 1 μm to 20 μm, 0.01 part by mass to 10 parts by mass (more preferably 0.05 parts by mass) with respect to 100 parts by mass of a vinyl monomer component. Part to 5 parts by mass, more preferably 1 part by mass to 2 parts by mass).
The polymerization temperature is preferably 60 ° C. to 100 ° C. (more preferably 65 ° C. to 95 ° C., more preferably 70 ° C. to 90 ° C.), and the polymerization reaction is 2 hours to 7 hours (more preferably 2.5 hours to 5 hours) And more preferably 3 hours to 4.5 hours). The polymerization reaction is preferably carried out in the range of pH 4 to pH 10.
Then, the organic polymer fine particles obtained by the polymerization reaction are subjected to solid-liquid separation of the dispersion liquid in which the organic polymer fine particles obtained by the dispersion reaction are dispersed and contained in the polymerization solvent. Examples of solid-liquid separation methods include filtration, centrifugation and the like.
In addition, when solid-liquid separation is performed, a coagulant may be used. Flocculants include sodium chloride, magnesium chloride, calcium chloride, sodium sulfate, aluminum sulfate, zinc sulfate, magnesium sulfate, sodium hydrogencarbonate, sodium bicarbonate, sodium carbonate, ammonium chloride, potassium chloride, metal salts such as potassium alum; sulfuric acid, hydrochloric acid, phosphoric acid, Examples thereof include acids such as nitric acid, carbonic acid and acetic acid; alcohols such as methanol and ethanol. These flocculants may be used alone or in combination of two or more.
Although the addition amount of the said coagulant | flocculant is not specifically limited, It is 0.05 mass part-10 mass parts with respect to 100 mass parts of organic polymer microparticles | fine-particles in a dispersion liquid. The time required for aggregation is short, usually from 0.1 minutes to 2 hours. Therefore, the rapid addition of the flocculant is not preferable because stirring may be impossible, and it is preferable to gradually add the flocculant to the dispersion. Moreover, as for the temperature of the dispersion liquid at the time of adding a coagulant | flocculant, 30 degreeC-100 degreeC is preferable.
3. Use
The fine particles of the organic polymer fine particles of the present invention are smaller than conventional particles, for example, the weight reduction rate at 230 to 280 ° C. is small, and the heat resistance is excellent. Accordingly, when the organic polymer fine particles of the present invention are melt mixed with the resin in a non-oxidative atmosphere such as a nitrogen atmosphere, it is difficult to generate decomposition products, and it is difficult to generate resin coloring, residual bubbles and the like. It can be suitably used as an additive for resin. Examples of the resin to which the organic polymer fine particles of the present invention are added include thermoplastic resins, preferably polyester resins, polyolefin resins, polyamide resins, polyurethane resins, (meth) acrylic resins, polycarbonate resins, polystyrene resins and the like. Among these, when the organic polymer fine particles of the present invention are used as an additive of a polyester resin which has a relatively high melting point and needs to carry out melt mixing at a high temperature, the effects of the present invention are more exhibited.
Among the additives for resin, the organic polymer fine particle of the present invention is excellent in heat resistance, further suppressed in coloring (excellent in achromaticity), and the resin refractive index of the organic polymer fine particle can be controlled in a relatively wide range depending on the composition. It is useful as an antiblocking agent and light diffusing agent. When the organic polymer fine particles of the present invention are used as an additive for resin, the organic polymer fine particles may be used alone or in combination with other components.
4. Master Badge
As described above, the organic polymer fine particles of the present invention are useful as additives for resins. Further, since the organic polymer fine particles of the present invention are excellent in heat resistance, the melt processing temperature can be increased, and mixing at a lower melt viscosity becomes possible. Therefore, even if the compounding amount of the organic polymer particles to the resin is increased, the organic polymer particles can be easily dispersed uniformly. Therefore, the masterbatch containing the organic polymer fine particle of this invention and resin is also a preferable aspect.
The resin used for the masterbatch is preferably a thermoplastic resin, more preferably a polyester resin, a polyolefin resin, a polyamide resin, a polyurethane resin, a (meth) acrylic resin, a polycarbonate resin, a polystyrene resin and the like. Among these, when the organic polymer fine particles of the present invention are used as an additive of a polyester resin which has a relatively high melting point and needs to carry out melt mixing at a high temperature, the effects of the present invention are more exhibited. Therefore, a masterbatch containing the polyester additive and the polyester additive containing the organic polymer fine particles of the present invention is a preferred embodiment of the present invention.
The above-mentioned polyester resin is not particularly limited. For example, polyethylene terephthalate, polytrimethylene terephthalate, polytetramethylene terephthalate, polycyclohexylene dimethylene terephthalate, polyethylene-2,6-naphthalate, polytetramethylene-2,6-naphthalate And aromatic polyester resins are preferred. These may be used alone or in combination of two or more. Among these, polyethylene terephthalate resin is preferable.
The content of the organic polymer fine particles in the master batch is not particularly limited, but is preferably 0.1 parts by mass or more, more preferably 1 part by mass or more, still more preferably 5 parts by mass with respect to 100 parts by mass of the resin in the master batch. The content is not less than 400 parts by mass, preferably 200 parts by mass or less, more preferably 100 parts by mass or less, and still more preferably 80 parts by mass or less.
As a method of preparing a masterbatch containing the organic polymer fine particles of the present invention, a method of adding and mixing the organic polymer fine particles in the polymerization step of synthesizing the resin; melting the resin after polymerization using an extruder etc. A method of mixing; a method of adding and mixing organic polymer fine particles in a state where the resin is dissolved in a solvent can be adopted. Among these, the method of melt-mixing is effective because the effect of using the organic polymer fine particles of the present invention is remarkably exhibited and the resin composition containing the organic polymer fine particles dispersed at a high concentration is easily produced. Suitable for batch production.
As a method of mixing in the polymerization step of synthesizing a resin, for example, when added to a polyester resin such as polyethylene terephthalate (PET) or polyethylene naphthalate (PEN), a glycol component such as ethylene glycol and a dicarboxylic acid (ester) component At the time of the polymerization reaction of (1), organic polymer fine particles are dispersed in one component (preferably a glycol component), and the polymerization reaction is carried out in the presence of the organic polymer fine particles.
As a method of melt-kneading, for example, a method of mixing powder or pellet-like polyester resin and organic polymer fine particles (powder or a form dispersed in a solvent), melting polyester resin while stirring, and mixing treatment A method of mixing organic polymer fine particles (powder or dispersed in a solvent) in a state where the polyester resin is melted; and the like.
The prepared masterbatch is usually processed into powder form or pellet form. Then, the masterbatch is added to the same resin as the resin contained in this masterbatch and melt mixed to prepare a resin composition. By using the organic polymer fine particles of the present invention as an additive, a resin composition in which the generation of coloring and air bubbles is suppressed can be obtained.
5. Resin composition
A resin composition containing the organic polymer fine particles of the present invention and a resin is also a preferred embodiment. Since the organic polymer fine particles of the present invention are less likely to generate decomposition products when melt mixed with the resin in a non-oxidative atmosphere such as a nitrogen atmosphere, a resin composition in which coloring, residual air bubbles and the like are suppressed can get.
Further, since the organic polymer fine particles of the present invention hardly generate decomposition products even when the resin composition is heat-molded, a resin molded body in which coloring, residual bubbles and the like are suppressed can be obtained. In addition, since the dispersibility in the resin is good, a low haze resin molded product such as a film can be obtained.
The resin composition may be prepared by mixing the above-mentioned masterbatch and resin, or may be prepared directly by mixing the organic polymer fine particles of the present invention and the resin.
As a method of molding the resin composition into a film or the like, heat molding such as injection molding or extrusion molding; a method of diluting the resin composition with a solvent and applying a liquid resin composition to a support serving as a substrate And the like.
The method of mixing the polyester resin additive with the polyester resin is not particularly limited, and may be added at the polymerization stage of the polyester resin, or the polyester resin after polymerization may be melt mixed using an extruder or the like. May be

表１に示すように、４Ｈ−ＴＥＭＰＯを用いて製造し、４Ｈ−ＴＥＭＰＯを６６０ｐｐｍ含む実施例１の有機重合体微粒子では、走査型電子顕微鏡を用いた観察で微小粒子は平均９個と少なく、ろ液の固形分も０．９３％と少なかった。これに対し、４Ｈ−ＴＥＭＰＯを用いずに製造し、４Ｈ−ＴＥＭＰＯを含まない比較例１の有機重合体微粒子では、走査型電子顕微鏡を用いた観察で微小粒子が平均１１４個と多く観察され、ろ液の固形分も４．９１％と多かった。
図２に、有機重合体微粒子中の懸濁粒子（残渣）と微小粒子（ろ液の固形分）、それぞれの熱分解評価として、窒素雰囲気中、２８０℃（最高到達温度）で２時間保持する条件で測定したＴＧ（Ｔｈｅｒｍｏ ｇｒａｖｉｔｙ）曲線を示す。横軸は、測定開始を０分としている。
図２に示すように、懸濁粒子では、２８０℃到達時から１２０分経過後の重量減少率は３．５４ｗｔ％と少なく、微小粒子では８．８０ｗｔ％と大きいことが分かった。
図３に、実施例１と比較例１の有機重合体微粒子の熱分解評価として、窒素雰囲気中、２３０℃（最高到達温度）で２時間保持する条件で測定したＴＧ（Ｔｈｅｒｍｏ ｇｒａｖｉｔｙ）曲線を、表１に所定時間経過後の重量減少率を示す。図３の横軸は、測定開始を０分としている。得られた有機重合体微粒子を熱可塑性樹脂用添加剤として使用する際、２３０℃のような比較的低い温度領域で分解が進行すると、気泡の発生による樹脂の不透明化やひび割れなどの悪影響が出る。このため、２３０℃での分析条件で重量減少率の少ないものが樹脂用添加剤として優れている。
図３と表１に示すように、比較例１の有機重合体微粒子では、２３０℃到達時から１２０分経過後の重量減少率は２．２０ｗｔ％（Δｗｔ％は０．４４ｗｔ％）であった。これに対し、実施例１の有機重合体微粒子では、２３０℃到達時から１２０分経過後の重量減少率は１．４５ｗｔ％（Δｗｔ％は０．１３ｗｔ％）と少なく、優れた耐熱性を示した。
このように、４Ｈ−ＴＥＭＰＯを含み、微小粒子が少なく、ろ液の固形分が少ない有機重合体微粒子では、優れた耐熱性が得られた。以上より、有機重合体微粒子中の微小粒子の発生を抑制することにより、有機重合体微粒子の耐熱性を向上させることができることが分かった。
［実施例２〜１１］
モノマー組成、酸化防止剤、重合禁止剤、４Ｈ−ＴＥＭＰＯならびに開始剤の種類・使用量を、表２に示すように変更した以外は、実施例１と同様にして、有機重合体微粒子をそれぞれ得た。得られた各有機重合体微粒子の熱分解評価結果、ならびに微小粒子の個数（平均）、ろ過固形分、平均粒子径、ＣＶ値の評価結果を表２に示した。なお、表２において、粒子径は体積平均粒子径である。
また、得られた各有機重合体微粒子は、実施例１と同様に、４−ヒドロキシ−２，２，６，６−テトラメチルピペリジン−１−オキシルフリーラジカル（４Ｈ−ＴＥＭＰＯ）を１０ｐｐｍ以上含んでいる。
［実施例１２］
モノマー組成、架橋剤、酸化防止剤ならびに開始剤の種類・使用量を、表２に示すように変更し、モノマーに対して５質量％のイソプロピルエーテルを添加しＴ．Ｋ．ホモジナイザーにより１００００ｒｐｍで１３分間撹拌した以外は、実施例１と同様にして、有機重合体微粒子を得た。得られた各有機重合体微粒子の熱分解評価結果、ならびに微小粒子の個数（平均）、ろ過固形分、平均粒子径、ＣＶ値の評価結果を表２に示した。
また、得られた各有機重合体微粒子は、実施例１と同様に、４−ヒドロキシ−２，２，６，６−テトラメチルピペリジン−１−オキシルフリーラジカル（４Ｈ−ＴＥＭＰＯ）を１０ｐｐｍ以上含んでいる。
［実施例１３〜１６］
モノマー組成、架橋剤、酸化防止剤ならびに開始剤の種類・使用量を、表３に示すように変更した以外は、実施例１と同様にして、有機重合体微粒子を得た。得られた各有機重合体微粒子の熱分解評価結果、ならびに微小粒子の個数（平均）、ろ過固形分、平均粒子径、ＣＶ値の評価結果を表３に示した。
また、得られた各有機重合体微粒子は、実施例１と同様に、４−ヒドロキシ−２，２，６，６−テトラメチルピペリジン−１−オキシルフリーラジカル（４Ｈ−ＴＥＭＰＯ）を１０ｐｐｍ以上含んでいる。
［比較例２〜５］
４Ｈ−ＴＥＭＰＯを使用せず、モノマー組成を、表４に示す使用割合に変更した以外は、実施例１と同様にして、有機重合体微粒子をそれぞれ得た。比較例２では、４Ｈ−ＴＥＭＰＯの代わりに亜硝酸ナトリウムを使用した。得られた有機重合体微粒子の評価結果を表４に示した。なお、表４において、粒子径は、体積平均粒子径である。
表２〜表４中、架橋剤ＤＶＢ５７０は、ＤＶＢ５７０（新日鐵化学社製、ジビニルベンゼン含有量５５〜６０質量％、エチルビニルベンゼン含有量３５〜４０質量％）；酸化防止剤ＡＯ−４１２Ｓ、ＰＥＰ−３６は、硫黄系酸化防止剤（株式会社ＡＤＥＫＡ製、商品名「アデカスタブ（登録商標）ＡＯ−４１２Ｓ」、商品名「アデカスタブ（登録商標）ＰＥＰ−３６」である。
また、参考までに、実施例と比較例の有機重合体微粒子における、窒素雰囲気中で、２８０℃（最高到達温度）で２時間保持した場合の、所定時間経過後の重量減少率を表２〜表４に示した。なお、表４において、※１は、微小粒子よりも樹脂状の重合物が多く存在し、粒子のみを単離することができず、評価できなかった。※２は、データを取得できなかった。

表２〜表４に示すように、４Ｈ−ＴＥＭＰＯを用いて製造した実施例の有機重合体微粒子では、走査型電子顕微鏡を用いた観察で微小粒子は少なく、ろ液の固形分も少なかった。４Ｈ−ＴＥＭＰＯを用いることにより、懸濁重合の収率を高くすることができた。
これに対し、４Ｈ−ＴＥＭＰＯを用いずに製造した比較例の有機重合体微粒子では、走査型電子顕微鏡を用いた観察で微小粒子が多く観察され、ろ液の固形分も多かった。４Ｈ−ＴＥＭＰＯの代わりに亜硝酸ナトリウムを使用した比較例２も同様であった。Hereinafter, the present invention will be described in more detail by way of examples, but the present invention is not limited thereto. Moreover, in the Example described below, "part" represents a "mass part" and "%" represents a "mass%."
<Evaluation method>
(1) Volume Average Particle Size The particle size of 30,000 particles is measured by a particle size distribution measuring apparatus ("Coulter Multisizer III type" manufactured by Beckman Coulter Co., Ltd.), and the volume average particle size is determined from the volume based particle size distribution. The standard deviation of the particle diameter was determined, and the CV value (coefficient of variation) of the particle diameter was calculated according to the following equation.
Particle size CV value (%) = 100 × (standard deviation of particle size / volume average particle size)
(2) Thermal decomposition evaluation The thermal decomposition evaluation of the obtained organic polymer fine particles is carried out using a thermal analyzer (“differential thermal balance Thermo plus EV02 / TG-DTA” manufactured by Rigaku Corporation), and the sample amount 10 mg, nitrogen In the atmosphere, the flow rate was 200 ml / min, the temperature rising rate was 10 ° C./min, and the measurement was performed at 230 ° C. or 280 ° C. (maximum achieved temperature) for 2 hours. Then, the heat resistance of the organic polymer fine particles was evaluated from the obtained TG (Thermo gravity) curve.
(3) Quantification of Compound For the determination of 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl free radical, gas chromatography (6890N (trade name), manufactured by Agilent Technologies, capillary column DB-1 (trade name) (Trade name); measured using a length of 30 m × inner diameter of 0.25 mm and a film thickness of 0.25 μm). The 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl free radical contained in 0.2 parts of the obtained organic polymer fine particles is extracted using 1 part of acetone as an extraction medium, It calculated using the calibration curve created in.
(4) The number of microparticles adhering to the surface of the suspended particles Using a scanning electron microscope (SEM) ("JCM-6000 NeoScope" manufactured by Nippon Denshi Co., Ltd.), the organic polymer microparticles are subjected to 5000 times magnification It observed and the number of the microparticles adhering to the suspended particle surface was computed with the following method. The fine particles have a diameter of 50 to 300 nm, and the suspended particles have a diameter of 1 μm or more.
Ten suspended particles were observed, the number of microparticles attached to the surface of each suspended particle was counted, and the average number of microparticles attached to one suspended particle was calculated.
(5) Measurement of the amount of fine particles in the filtrate (filtrate solid content)
The polymerization solution in which the polymerization reaction was completed was filtered using filter paper (quantitative filter paper "No. 5C" made by Advantec Toyo Kaisha, Ltd.) to separate fine particles (filtrate) and suspended particles (residue). 2 g of a filtrate containing fine particles was placed in an aluminum cup and dried by heating on a hot plate heated to 110 ° C. for 1 hour to evaporate water in the filtrate to obtain fine particles. From the weights before and after drying, the amount (%) of microparticles (filtrate solid content) contained in the filtrate was calculated according to the following formula.
Filtrate solid content (%)
= [Weight of microparticles obtained after drying the filtrate (g)] / [Flower weight (g)] x 100
Example 1
40 parts of N- (phenyl) maleimide (PMI), 100 parts of styrene (St), 40 parts of methyl methacrylate (MMA), 20 parts of trimethylolpropane trimethacrylate (TMPTMA), 1 part of lauryl peroxide (LPO) in a beaker Hindered phenolic antioxidant (Ciba Specialty Chemicals Inc., trade name “Irganox® 1010”, pentaerythritol tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) Propionate] 1 part was charged, and solid components were dissolved in a 35 ° C. water bath. In a flask equipped with a stirrer, an inert gas inlet tube, a reflux condenser and a thermometer, polyoxyethylene distyryl phenyl ether sulfate ammonium salt (trade name "Hiteen (registered trademark) NF 08", Daiichi Kogyo Co., Ltd.) 310 parts of deionized water in which 2 parts of Pharmaceutical Co., Ltd. is dissolved is added, and the beaker solution is added. K. The mixture is stirred at 8,000 rpm for 5 minutes with a homogenizer (manufactured by Tokushu Kika Kogyo Co., Ltd.) to obtain a uniform suspension, and 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl free radical (4H- 0.2 parts of TEMPO, "POLYSTOP 7010" manufactured by Shoto Co., Ltd. and 500 parts of deionized water were added.
Next, the flask was heated to a liquid temperature of 65 ° C. while blowing nitrogen gas into the flask, and the reaction vessel was kept at 65 ° C. The reaction starts when the liquid temperature reaches 74 ° C due to self-heating, and stirring is continued for 1 hour at this temperature, and then the polymerization solution is further heated to 85 ° C and stirred for 1.5 hours to complete the polymerization reaction. did. Thereafter, while stirring, 33.6 parts of deionized water in which 0.6 parts of aluminum sulfate is dissolved is added at 85 ° C., and after stirring for 1.5 hours at this temperature, the reaction solution is cooled, filtered, and polymerized. The product was dried with hot air at 80 ° C. for 12 hours to obtain organic polymer fine particles.
The obtained organic polymer fine particles had an average particle diameter of 2.77 μm and a CV value (coefficient of variation) of 40.1%. In addition, the obtained organic polymer fine particles contained 660 ppm of 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl free radical (4H-TEMPO). Table 1 describes the use ratio of each component, where the total of the monomer composition component and the crosslinking agent is 100 parts by mass. Further, the evaluation results of the obtained organic polymer fine particles are shown in Table 1. In Table 1, the particle size is a volume average particle size. The moisture content of the organic polymer fine particles was 1% or less.
In addition, since the obtained organic polymer fine particles are coagulated by drying, they were crushed at a normal pressure of 0.4 MPa at normal temperature using Super Jet Mill SJ-500 (manufactured by Nisshin Engineering Co., Ltd.) . This gave organic polymer fine particles without aggregation.
Preparation of master batch 10 parts of the obtained organic polymer fine particles, 90 parts of polyethylene terephthalate pellets (SA-8339P Unitika Co., Ltd.), 0.15 parts of Irganox (registered trademark) 1010 as an antioxidant, and Irgafos (registered) The mixture was mixed with 0.15 part of a trademark 168 using a co-rotating twin-screw kneader-extruder (HK-25D manufactured by Parker Corporation), melt-kneaded at 250 ° C., and water cooled to obtain a strand. By appropriately cutting the obtained strand, a polyethylene terephthalate master batch containing 10% of organic polymer fine particles was produced.
Production of Cast Film A cast film of two types and three layers was produced using the obtained polyethylene terephthalate master batch and polyethylene terephthalate pellets. A configuration was adopted in which the organic polymer fine particle-added skin layer was laminated on both sides of the core layer. The cast film was extruded at 280 ° C. using a T-die extruder (made by Soken Co., Ltd.). Two parts of the organic polymer fine particle added skin layer used 1 part of a 10% masterbatch of organic polymer fine particles, 9 parts of polyethylene terephthalate pellets, and the core layer used 180 parts of only polyethylene terephthalate pellets. The cast film had a thickness of 16 μm for the organic polymer fine particle-added skin layer and 288 μm for the core layer, and a cast film having a total thickness of 320 μm was obtained.
Preparation of Biaxially Stretched Film The obtained cast film is cut into length × width = 9 cm × 9 cm, and using a simultaneous biaxial stretching machine (made by Toyo Seiki Co., Ltd.), the draw ratio is 3 under the heating condition of 130 ° C. A biaxially stretched film was obtained by performing simultaneous biaxial stretching at a setting of double and lateral 3 times. The size of the obtained biaxially stretched film was 22 cm × 22 cm. The average thickness of the central portion of the biaxially stretched film was 10 μm, but the film end portion was about 40 μm, and the central portion 12 cm × 12 cm to 18 cm × 18 cm portion mainly had a film thickness of about 10 μm.
The surface of the central part of the obtained biaxially stretched film was observed with a scanning electron microscope (SEM) ("JCM-6000 NeoScope" manufactured by Nippon Denshi Co., Ltd.) in a 500 × field of view. It was confirmed that organic polymer fine particles were present on the surface of the biaxially stretched film. The SEM photograph of the biaxially stretched film surface is shown in FIG. Furthermore, it was 0.96 when the haze of the center part of the obtained biaxially stretched film was measured using the haze meter (made by NDH7000 Nippon Denshoku Industries Co., Ltd.).
Comparative Example 1
Fine organic polymer particles were produced in the same manner as in Example 1 except that 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl free radical (4H-TEMPO) was not used. The evaluation results of the obtained organic polymer fine particles are shown in Table 1.

As shown in Table 1, in the organic polymer fine particles of Example 1 which is produced using 4H-TEMPO and contains 660 ppm of 4H-TEMPO, the average number of fine particles is as small as 9 in observation using a scanning electron microscope, The solid content of the filtrate was also as low as 0.93%. On the other hand, in the organic polymer fine particles of Comparative Example 1 manufactured without 4H-TEMPO and not containing 4H-TEMPO, an average of 114 fine particles are observed in many cases by observation using a scanning electron microscope, The solid content of the filtrate was also as high as 4.91%.
As shown in FIG. 2, suspended particles (residues) and fine particles (solid content of filtrate) in organic polymer fine particles are maintained at 280 ° C. (maximum achieved temperature) for 2 hours in a nitrogen atmosphere as their thermal decomposition evaluation. The TG (Thermo gravity) curve measured on condition is shown. The horizontal axis indicates that the measurement start is 0 minutes.
As shown in FIG. 2, with suspended particles, it was found that the weight reduction rate after 120 minutes had reached 280 ° C. was as small as 3.54 wt%, and for microparticles as high as 8.80 wt%.
In FIG. 3, as thermal decomposition evaluation of the organic polymer fine particles of Example 1 and Comparative Example 1, a TG (Thermo gravity) curve measured under a condition of being held at 230 ° C. (maximum achieved temperature) for 2 hours in a nitrogen atmosphere is Table 1 shows the weight reduction rate after a predetermined time has elapsed. The horizontal axis in FIG. 3 indicates that the measurement start is 0 minutes. When using the obtained organic polymer fine particles as an additive for a thermoplastic resin, if decomposition progresses in a relatively low temperature region such as 230 ° C., adverse effects such as opacification and cracking of the resin due to generation of air bubbles occur . For this reason, those having a small weight loss rate under analysis conditions at 230 ° C. are excellent as additives for resins.
As shown in FIG. 3 and Table 1, in the organic polymer fine particles of Comparative Example 1, the weight reduction rate after 120 minutes from when reaching 230 ° C. was 2.20 wt% (Δwt% is 0.44 wt%) . On the other hand, in the case of the organic polymer fine particles of Example 1, the weight reduction rate after 120 minutes after reaching 230 ° C. is as low as 1.45 wt% (Δwt% is 0.13 wt%), showing excellent heat resistance. The
Thus, excellent heat resistance was obtained with organic polymer fine particles containing 4H-TEMPO, having a small number of fine particles, and having a low solid content of the filtrate. From the above, it has been found that the heat resistance of the organic polymer particles can be improved by suppressing the generation of the particles in the organic polymer particles.
[Examples 2 to 11]
Organic polymer fine particles were obtained in the same manner as in Example 1, except that the monomer composition, the antioxidant, the polymerization inhibitor, 4H-TEMPO and the type and amount of the initiator were changed as shown in Table 2. The The evaluation results of the thermal decomposition evaluation of each of the obtained organic polymer fine particles, and the number of microparticles (average), the filtration solid content, the average particle diameter, and the evaluation result of the CV value are shown in Table 2. In Table 2, the particle size is a volume average particle size.
Each of the obtained organic polymer fine particles contained 10 ppm or more of 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl free radical (4H-TEMPO) as in Example 1. There is.
[Example 12]
The monomer composition, types of crosslinking agent, antioxidant, and initiator were changed as shown in Table 2, and 5% by mass of isopropyl ether was added to the monomer to obtain T.I. K. Fine organic polymer particles were obtained in the same manner as in Example 1 except that stirring was performed at 10000 rpm for 13 minutes using a homogenizer. The evaluation results of the thermal decomposition evaluation of each of the obtained organic polymer fine particles, and the number of microparticles (average), the filtration solid content, the average particle diameter, and the evaluation result of the CV value are shown in Table 2.
Each of the obtained organic polymer fine particles contained 10 ppm or more of 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl free radical (4H-TEMPO) as in Example 1. There is.
[Examples 13 to 16]
Organic polymer fine particles were obtained in the same manner as in Example 1 except that the monomer composition, the type of the crosslinking agent, the antioxidant and the type and the amount of the initiator were changed as shown in Table 3. The evaluation results of the thermal decomposition evaluation of each of the obtained organic polymer fine particles, and the number (average) of the fine particles, the filtration solid content, the average particle diameter, and the evaluation result of the CV value are shown in Table 3.
Each of the obtained organic polymer fine particles contained 10 ppm or more of 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl free radical (4H-TEMPO) as in Example 1. There is.
[Comparative examples 2 to 5]
Organic polymer fine particles were obtained in the same manner as in Example 1 except that 4H-TEMPO was not used, and the monomer composition was changed to the use ratio shown in Table 4. In Comparative Example 2, sodium nitrite was used instead of 4H-TEMPO. The evaluation results of the obtained organic polymer fine particles are shown in Table 4. In Table 4, the particle size is a volume average particle size.
In Tables 2 to 4, the crosslinking agent DVB 570 is DVB 570 (manufactured by Nippon Steel Chemical Co., Ltd., divinylbenzene content 55 to 60% by mass, ethylvinylbenzene content 35 to 40% by mass); antioxidant AO-412S, PEP-36 is a sulfur-based antioxidant (trade name "ADEKA STAB (registered trademark) AO-412S" manufactured by ADEKA Co., Ltd., trade name "ADEKA STAB (registered trademark) PEP-36").
Further, for reference, the weight reduction rate after a predetermined time when the organic polymer fine particles of the example and the comparative example are held at 280 ° C. (maximum achieved temperature) for 2 hours in a nitrogen atmosphere is shown in Table 2 It is shown in Table 4. In addition, in Table 4, in the case of * 1, a large amount of resin-like polymer was present rather than microparticles, and only particles could not be isolated, and therefore evaluation was not possible. ※ 2 could not get the data.

As shown in Tables 2 to 4, in the organic polymer fine particles of the example manufactured using 4H-TEMPO, the number of fine particles was small and the solid content of the filtrate was also small by observation using a scanning electron microscope. The yield of suspension polymerization could be increased by using 4H-TEMPO.
On the other hand, in the organic polymer fine particles of the comparative example manufactured without using 4H-TEMPO, many fine particles were observed by observation using a scanning electron microscope, and the solid content of the filtrate was also large. The same applies to Comparative Example 2 in which sodium nitrite was used instead of 4H-TEMPO.

  The organic polymer fine particles of the present invention have higher heat resistance than conventional particles. Therefore, the organic polymer fine particle of the present invention can be suitably used as an additive for resin such as an antiblocking agent and a light diffusing agent.

Claims (4)

Two Toro hexyl radical compounds presence, to suspension polymerization of a vinyl monomer,
The method for producing organic polymer fine particles, wherein the addition amount of the nitroxyl radical compound is 0.05 to 0.5 parts by mass with respect to 100 parts by mass of the total amount of the vinyl-based monomer component. The nitroxyl radical compound is 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl
A method of producing organic polymer fine particles according to claim 1 . The vinyl-based monomer contains a styrene-based monomer
The manufacturing method of the organic polymer fine particle of Claim 1 or 2 . The vinyl-based monomer contains a maleimide-based monomer
The manufacturing method of the organic polymer fine particle of any one of Claims 1-3 .

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