JPH08134224A - Redispersible resin - Google Patents
Redispersible resinInfo
- Publication number
- JPH08134224A JPH08134224A JP27963894A JP27963894A JPH08134224A JP H08134224 A JPH08134224 A JP H08134224A JP 27963894 A JP27963894 A JP 27963894A JP 27963894 A JP27963894 A JP 27963894A JP H08134224 A JPH08134224 A JP H08134224A
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- JP
- Japan
- Prior art keywords
- resin
- water
- powder
- spray
- emulsion
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
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- Processes Of Treating Macromolecular Substances (AREA)
- Compositions Of Macromolecular Compounds (AREA)
Abstract
Description
【0001】[0001]
【産業上の利用分野】本発明は、再分散可能な樹脂に関
するものであり、さらに詳しくは、粉体の噴霧乾燥時の
耐ブロッキング性が良好で、水に再分散させた際に、再
分散性及びその再分散液の造膜性が良好である再分散可
能な樹脂に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a redispersible resin, and more specifically, it has good blocking resistance during powder spray drying and is redispersible when redispersed in water. And a redispersible resin having good film-forming property of the redispersion liquid.
【0002】[0002]
【従来の技術】近年、地球環境保護の対策として、コー
ティング材料や各種添加剤等に用いられる合成樹脂は、
無公害、省資源で作業性等の点から溶剤系材料から、水
分散型樹脂や水溶性樹脂など分散型やエマルション型の
水系材料に移行しつつある。この分散型の水系材料のう
ち、加水して攪拌混合することにより、容易に水に再分
散する粉末状樹脂は水再分散型樹脂と言われているが、
これは、使用する直前に加水するため、従来のエマルシ
ョン型の水系材料に比べ、包装が簡単で、輸送がしや
すい、貯蔵安定性が良好であり凍結の心配がない、
使用後に包装容器の廃棄処理がしやすい、などの特徴を
有している。2. Description of the Related Art In recent years, as a measure for protecting the global environment, synthetic resins used as coating materials and various additives are
From the viewpoints of pollution-free, resource saving, workability, etc., solvent-based materials are being shifted to dispersion-type or emulsion-type water-based materials such as water-dispersible resins and water-soluble resins. Of these dispersion-type water-based materials, a powdered resin that is easily redispersed in water by mixing with water and stirring is said to be a water-redispersion type resin.
This is because water is added immediately before use, compared to conventional emulsion-type water-based materials, easier to wrap, easier to transport, has good storage stability, and is free from fear of freezing.
It has features such as easy disposal of the packaging container after use.
【0003】通常、再分散型樹脂を得る方法として、噴
霧乾燥法、凍結乾燥法、減圧乾燥法などが挙げられる
が、一般に生産性等の観点からエマルション樹脂を熱風
中に噴霧分散させ、該熱風で搬送しながら急速に乾燥し
て粉体を得る噴霧乾燥法が広く採用されている。Usually, as a method for obtaining a redispersion type resin, a spray drying method, a freeze drying method, a reduced pressure drying method and the like can be mentioned. Generally, from the viewpoint of productivity and the like, the emulsion resin is sprayed and dispersed in hot air to obtain the hot air. A spray-drying method is widely adopted in which powder is rapidly dried while being transported by.
【0004】しかし、このような噴霧乾燥法で再分散型
樹脂粉体を製造する場合には、最低造膜温度の低いエマ
ルション樹脂を用いると、噴霧乾燥塔内の内壁、エマル
ション樹脂を噴霧するアトマイザー口、粉体出口、及び
噴霧分散した粉体を熱風で搬送する搬送管中など(以
下、噴霧乾燥装置の内壁と示す。)に付着、堆積した
り、また該粉体同士の融着が起こりブロッキングが激し
く塊状物となり加水しても再分散しないといった問題が
あり、コーティング材料等に要求される20℃以下とい
う低い最低造膜温度を有する再分散型樹脂粉体を効率よ
く製造することができなかった。However, when a redispersible resin powder is produced by such a spray drying method, if an emulsion resin having a low minimum film forming temperature is used, the inner wall of the spray drying tower and an atomizer for spraying the emulsion resin are used. Adhesion and deposition on the mouth, powder outlet, and in a carrier pipe that carries the spray-dispersed powder with hot air (hereinafter referred to as the inner wall of the spray dryer), and the fusion of the powder particles occurs. There is a problem that blocking is intense and it becomes a lump and does not redisperse even if water is added, and it is possible to efficiently produce a redispersion type resin powder having a low minimum film forming temperature of 20 ° C. or lower required for coating materials and the like. There wasn't.
【0005】[0005]
【発明が解決しようとする課題】そこで、このような噴
霧乾燥法による再分散型樹脂粉末の問題点を解決するた
めに、噴霧乾燥塔内でエマルション樹脂と同時に水分散
型無機粒子を霧化し、気流中で粒状になった再分散型樹
脂粉体を該無機粒子で被覆することによって、噴霧乾燥
装置の内壁への付着、堆積や粉末同士の融着を防ぐ方法
(特公昭55−50971号公報)が提案されている。
しかしながら、このような方法で得られた再分散型樹脂
粉体は、前記無機粒子がその表面に残存するため、コー
ティング材としての塗膜の透明性が低下したり、本質的
に融着しやすい樹脂が再分散型樹脂粉体内部に存在して
いるため、積載等の保存時に粉体同士のブロッキングが
発生し、長期保存性が不良となるといった問題点を有し
ていた。Therefore, in order to solve the problem of the redispersion type resin powder by the spray drying method, the water dispersion type inorganic particles are atomized simultaneously with the emulsion resin in the spray drying tower, A method of preventing re-dispersion type resin powder in the form of particles in an air stream from being covered with the inorganic particles so as to prevent adhesion to the inner wall of the spray dryer, deposition and fusion of the powders (Japanese Patent Publication No. 55-50971). ) Is proposed.
However, in the redispersion type resin powder obtained by such a method, since the inorganic particles remain on the surface of the resin powder, the transparency of the coating film as a coating material is lowered, or the resin particles are essentially fused easily. Since the resin is present inside the redispersion type resin powder, there is a problem in that the powder particles are blocked during storage such as loading, resulting in poor long-term storability.
【0006】また、最低造膜温度の低いエマルション樹
脂に保護コロイドとしてポリビニルアルコールを多量に
添加し、噴霧乾燥する方法(特公昭46−12907号
公報)が提案されているが、この方法は、ポリビニルア
ルコールと相溶性の低い樹脂を用いた再分散液では相分
離が生じてしまい、これをコーティング材として用いた
場合には、成膜不良となり均一なコーティング膜を得る
ことはできない。そこで、多量のポリビニルアルコール
を使用することによって、樹脂粉体同士の融着を防止
し、エマルション中での樹脂の分散性を向上させること
が考えられるが、多量のポリビニルアルコールを使用す
るため、コーティング膜の耐水性、耐候性が不良となる
などエマルション本来の物性が発現し難くなるという問
題点を有している。[0006] Further, a method has been proposed in which a large amount of polyvinyl alcohol is added as a protective colloid to an emulsion resin having a low minimum film forming temperature, and spray drying is performed (Japanese Patent Publication No. 46-12907). A redispersion liquid using a resin having a low compatibility with alcohol causes phase separation, and when this is used as a coating material, the film formation becomes defective and a uniform coating film cannot be obtained. Therefore, by using a large amount of polyvinyl alcohol, it is possible to prevent fusion of the resin powders to each other and improve the dispersibility of the resin in the emulsion, but since a large amount of polyvinyl alcohol is used, coating There is a problem that the original physical properties of the emulsion are difficult to be expressed, such as poor water resistance and weather resistance of the film.
【0007】さらに、特開平5−194681号公報に
は、アルカリ可溶性の乳化重合体の殻と、水不溶性の乳
化重合体の芯を有する、芯−殻の粒子構造を持たせた重
合体粉末の製造方法が提案されている。しかし、このよ
うな特定の粒子構造を有する重合体粉末においても、重
合体粉末の耐ブロッキング性と20℃以下という低い最
低造膜温度の両性能を同時に満足する再分散可能な樹脂
を得ることは困難である。Further, JP-A-5-194681 discloses a polymer powder having a core-shell particle structure having an alkali-soluble emulsion polymer shell and a water-insoluble emulsion polymer core. Manufacturing methods have been proposed. However, even with a polymer powder having such a specific particle structure, it is not possible to obtain a redispersible resin that simultaneously satisfies both the blocking resistance of the polymer powder and the low minimum film forming temperature of 20 ° C. or lower. Have difficulty.
【0008】[0008]
【課題を解決するための手段】本発明者らは、上記課題
について鋭意検討を行った結果、ガラス転移温度(以
下、Tgと示す。)が15℃以上の樹脂からなる水分散
型樹脂粉体と、Tgが15℃以上でかつ特定酸価以上の
水溶解型樹脂粉体とを、別々もしくは同時に混合して噴
霧乾燥すると、これをアルカリ条件下で加水し再分散液
とした時に、樹脂粉体の耐ブロッキング性と再分散液の
最低造膜温度を低減できる再分散可能な樹脂が得られる
ことを見いだし、本発明を完成するにいたった。Means for Solving the Problems As a result of intensive studies on the above problems, the present inventors have found that a water-dispersible resin powder made of a resin having a glass transition temperature (hereinafter referred to as Tg) of 15 ° C. or higher. And a water-soluble resin powder having a Tg of 15 ° C. or more and a specific acid value or more are separately or simultaneously mixed and spray-dried, and when this is hydrolyzed under alkaline conditions to form a redispersion liquid, the resin powder It was found that a redispersible resin capable of reducing the blocking resistance of the body and the minimum film-forming temperature of the redispersion liquid was obtained, and completed the present invention.
【0009】即ち、本発明の再分散可能な樹脂は、噴霧
乾燥により得られたTgが15℃以上である水分散型樹
脂粉体(A)と、噴霧乾燥により得られたTgが15℃
以上で且つ酸価が30mgKOH/g以上である水溶解
型樹脂粉体(B)とを含有してなることを特徴とするも
のである。That is, the redispersible resin of the present invention has a water-dispersible resin powder (A) having a Tg of 15 ° C. or higher obtained by spray drying and a Tg of 15 ° C. obtained by spray drying.
The water-soluble resin powder (B) having an acid value of 30 mgKOH / g or more is contained.
【0010】以下、本発明について詳細に説明する。本
発明の再分散可能な樹脂を得る方法には、水分散型樹
脂粉体(A)と水溶解型樹脂粉体(B)とを別々に噴霧
乾燥して、その後各粉体を混合して得る方法、又は、
水分散型樹脂粉体(A)を得るためのエマルション樹脂
及び水溶解型樹脂粉体(B)を得るためのエマルション
樹脂を混合して同時に噴霧乾燥して得る方法がある。但
し、後者のの同時に噴霧乾燥して再分散可能な樹脂を
得る方法は、低酸価の水溶解型樹脂粉体(B)を得るた
めのエマルション樹脂を用いると噴霧乾燥時に噴霧乾燥
装置内への付着や樹脂粉体同士のブロッキングが発生し
やすいため、高酸価のエマルション樹脂を用いることが
好ましい。The present invention will be described in detail below. To obtain the redispersible resin of the present invention, the water-dispersible resin powder (A) and the water-soluble resin powder (B) are separately spray-dried, and then each powder is mixed. How to obtain, or
There is a method in which an emulsion resin for obtaining the water-dispersible resin powder (A) and an emulsion resin for obtaining the water-soluble resin powder (B) are mixed and simultaneously spray-dried. However, in the latter method of simultaneously spray-drying to obtain a redispersible resin, when an emulsion resin for obtaining a water-soluble resin powder (B) having a low acid value is used, the resin is sprayed into a spray-drying apparatus at the time of spray-drying. It is preferable to use an emulsion resin having a high acid value because adhesion of the resin and blocking of the resin powders easily occur.
【0011】本発明で用いる水分散型樹脂粉体(A)及
び水溶解型樹脂粉体(B)は、いずれもTgが15℃以
上、好ましくは25℃以上であることが必要である。こ
れは、Tgが15℃未満であると、エマルション樹脂の
噴霧乾燥の際に、噴霧乾燥装置の内壁への樹脂粉体の付
着、堆積、あるいは樹脂粉体同士のブロッキングが発生
しやすくなり、塊状物の生成等により再分散性が著しく
低下するためである。Both the water-dispersible resin powder (A) and the water-soluble resin powder (B) used in the present invention must have Tg of 15 ° C. or higher, preferably 25 ° C. or higher. This is because if the Tg is less than 15 ° C., during spray drying of the emulsion resin, resin powder is likely to adhere to or deposit on the inner wall of the spray dryer, or the resin powder is blocked from each other. This is because the redispersibility is remarkably reduced due to the formation of the product.
【0012】すなわち、噴霧乾燥法により水分率が3%
以下の通常の乾燥度を有する粉体を得る場合には、粉体
出口の温度を45℃以上とする必要があるが、使用する
エマルション樹脂の物性上、粉体出口の温度が、エマル
ション樹脂のTgより30℃以上高くなった場合は樹脂
粉体同士のブロッキングが発生し、さらにエマルション
樹脂のTgより40℃以上高くなった場合は樹脂の塊状
物が生成することになる。つまり、再分散液の最低造膜
温度は、エマルション樹脂のTgの近傍にあることか
ら、結果として、噴霧乾燥装置内への付着、又は樹脂同
士のブロッキングが発生することなく、噴霧乾燥して粉
体を得るためには、Tgが15℃以上のエマルション樹
脂を粉体化する必要があり、結果として得られた樹脂の
Tgは15℃が下限となる。That is, the water content is 3% by the spray drying method.
In order to obtain a powder having the following normal dryness, it is necessary to set the temperature of the powder outlet to 45 ° C. or higher. However, due to the physical properties of the emulsion resin used, the temperature of the powder outlet should be the same as that of the emulsion resin. When the temperature is higher than Tg by 30 ° C. or more, blocking between the resin powder particles occurs, and when the temperature is higher than Tg of the emulsion resin by 40 ° C. or higher, resin lumps are formed. That is, since the minimum film forming temperature of the redispersion liquid is in the vicinity of the Tg of the emulsion resin, as a result, there is no sticking in the spray drying device or blocking between the resins, and the powder is spray-dried and powdered. In order to obtain a body, it is necessary to pulverize an emulsion resin having a Tg of 15 ° C. or higher, and the Tg of the resulting resin has a lower limit of 15 ° C.
【0013】本発明において、水分散型樹脂粉体(A)
としては、水に再分散可能であり、Tgが15℃であれ
ば特に限定されるものではなく、具体例としては、アク
リル樹脂、塩化ビニル樹脂、酢酸ビニル樹脂、スチレン
/アクリル樹脂、ポリビニルアルコール樹脂(以下、E
VA樹脂と示す)、オレフィン樹脂、その他上記樹脂同
士の共重合物や変性樹脂等が挙げられる。この水分散型
樹脂粉体(A)はエマルション樹脂(a)の噴霧乾燥に
よって製造され、このエマルション樹脂(a)を製造す
る方法としては、再分散性と分散安定性が確保されれば
特に限定されないが、例えば、分散安定性の良好な一次
粒子径の小さいエマルション樹脂(a)の製造方法とし
ては乳化重合法が好ましい。In the present invention, the water-dispersible resin powder (A)
Is not particularly limited as long as it is redispersible in water and has a Tg of 15 ° C., and specific examples include acrylic resins, vinyl chloride resins, vinyl acetate resins, styrene / acrylic resins, polyvinyl alcohol resins. (Hereafter, E
VA resin), olefin resin, and copolymers of the above resins, modified resins and the like. The water-dispersible resin powder (A) is produced by spray drying the emulsion resin (a), and the method for producing the emulsion resin (a) is not particularly limited as long as redispersibility and dispersion stability are secured. However, the emulsion polymerization method is preferable as a method for producing the emulsion resin (a) having good dispersion stability and a small primary particle diameter.
【0014】また、本発明で用いる水溶解型樹脂粉体
(B)は、アルカリ性条件下における水に再分散した後
に溶解し、水分散型樹脂粉体(A)の最低造膜温度を下
げるものであり、Tgが15℃以上、酸価が30mgK
OH/g以上のであることが重要であり、好ましくは、
Tgが25℃以上で、酸価が40mgKOH/g以上の
樹脂粉体である。この水溶解型樹脂粉体(B)は、分子
量により水溶解性が異なってくるものの、最低造膜温度
低下の効果を発現させるためには、その酸価は少なくと
も30mgKOH/gであることが必要である。これ
は、酸価が30mgKOH/g未満の場合には水溶解性
に劣り、再分散液の最低造膜温度の低下効果は小さいた
めである。具体的には、使用するエマルション樹脂
(b)の分子量が小さい場合には酸価が30mgKOH
/g以上、分子量が大きい場合には40mgKOH/g
以上とすることによって、良好な水溶解性が得られ、こ
れを用いた再分散液の最低造膜温度の低下効果を発現す
ることができる。The water-soluble resin powder (B) used in the present invention is re-dispersed in water under alkaline conditions and then dissolved to lower the minimum film forming temperature of the water-dispersible resin powder (A). And Tg of 15 ° C or higher, acid value of 30 mgK
It is important that it is OH / g or more, and preferably,
It is a resin powder having a Tg of 25 ° C. or higher and an acid value of 40 mgKOH / g or higher. Although this water-soluble resin powder (B) has different water solubility depending on the molecular weight, its acid value must be at least 30 mgKOH / g in order to exert the effect of lowering the minimum film-forming temperature. Is. This is because when the acid value is less than 30 mgKOH / g, the solubility in water is poor and the effect of lowering the minimum film forming temperature of the redispersion liquid is small. Specifically, when the molecular weight of the emulsion resin (b) used is small, the acid value is 30 mgKOH.
/ G or more, 40 mgKOH / g when the molecular weight is large
As described above, good water solubility is obtained, and the effect of lowering the minimum film forming temperature of the redispersion liquid using the same can be exhibited.
【0015】水溶解型樹脂粉末(B)としては、水に溶
解可能であり、Tgが15℃以上、酸価が30mgKO
H/g以上であれば特に限定されるものではなく、具体
例としては、アクリル酸、メタクリル酸等の二重結合を
有した酸モノマーを共重合させたポリカルボン酸樹脂な
どが挙げられる。また、水分散型樹脂粉体(A)との相
溶性を上げるために、塩化ビニル樹脂、酢酸ビニル樹
脂、スチレン/アクリル樹脂、EVA樹脂、オレフィン
樹脂等を、前記ポリカルボン酸樹脂に共重合させること
も可能である。これら水溶解型樹脂粉体(B)の製造方
法としては、特に限定されることはないが、懸濁重合法
または乳化重合法により得られたエマルション樹脂
(b)を噴霧乾燥により粉体化して得ることができる。The water-soluble resin powder (B) is soluble in water and has a Tg of 15 ° C. or higher and an acid value of 30 mgKO.
It is not particularly limited as long as it is H / g or more, and specific examples thereof include a polycarboxylic acid resin obtained by copolymerizing an acid monomer having a double bond such as acrylic acid and methacrylic acid. In order to improve the compatibility with the water-dispersible resin powder (A), vinyl chloride resin, vinyl acetate resin, styrene / acrylic resin, EVA resin, olefin resin, etc. are copolymerized with the polycarboxylic acid resin. It is also possible. The method for producing the water-soluble resin powder (B) is not particularly limited, but the emulsion resin (b) obtained by the suspension polymerization method or the emulsion polymerization method is pulverized by spray drying. Obtainable.
【0016】水分散型樹脂粉体(A)と水溶解型樹脂粉
体(B)の混合割合は、必要とする再分散可能な樹脂の
最低造膜温度により、任意に選択することができるが、
再分散性や最低造膜温度の観点から、水溶解型樹脂粉体
(B)の含有率を20〜80重量%とすることが好まし
く、さらに好ましくは30〜70重量%である。これ
は、水溶解型樹脂粉体(B)が多くなりすぎた再分散液
は、水分散型樹脂の形態をとることができず、水溶性樹
脂の形態となるため、粘度が著しく上昇する傾向にあ
り、逆に少なくなりすぎると最低造膜温度の低下効果が
十分でなくなる傾向にあるためである。The mixing ratio of the water-dispersible resin powder (A) and the water-soluble resin powder (B) can be arbitrarily selected depending on the required minimum film-forming temperature of the redispersible resin. ,
From the viewpoint of redispersibility and minimum film forming temperature, the content of the water-soluble resin powder (B) is preferably 20 to 80% by weight, more preferably 30 to 70% by weight. This is because the redispersion liquid containing too much water-soluble resin powder (B) cannot take the form of the water-dispersible resin and becomes the form of the water-soluble resin, so that the viscosity tends to remarkably increase. On the contrary, if the amount is too small, the effect of lowering the minimum film forming temperature tends to be insufficient.
【0017】この水溶解型樹脂粉体(B)がアルカリ性
条件下において最低造膜温度を下げるというメカニズム
としては、現時点では確かなことは言えないが、水溶解
型樹脂粉体(B)が水分散型樹脂粉体(A)の表面に吸
着、もしくは拡散することにより、水分散型樹脂粉体
(A)が可塑化され、各粉体の変形抵抗が小さくなり、
該粉体(A)と該粉体(B)との間の融着性が上がるた
めと考えられる。The mechanism by which the water-soluble resin powder (B) lowers the minimum film forming temperature under alkaline conditions is not certain at this point, but the water-soluble resin powder (B) is water-soluble. The water-dispersed resin powder (A) is plasticized by adsorbing or diffusing on the surface of the dispersion-type resin powder (A), and the deformation resistance of each powder decreases.
It is considered that this is because the fusion property between the powder (A) and the powder (B) is improved.
【0018】本発明の水分散型樹脂粉体(A)および水
溶解型樹脂粉体(B)を得る噴霧乾燥方法は特に限定さ
れるものではなく、通常用いられている噴霧乾燥装置を
使用して行うことができる。本発明の再分散可能な樹脂
を得る方法には、水分散型樹脂粉体(A)と水溶解型
樹脂粉体(B)とを別々に噴霧乾燥して、その後各粉体
を混合して得る方法、または、水分散型樹脂粉体
(A)を得るためのエマルション樹脂及び水溶解型樹脂
粉体(B)を得るためのエマルション樹脂を混合して同
時に噴霧乾燥して得る方法がある。但し、後者のの同
時に噴霧乾燥して再分散可能な樹脂を得る方法は、水溶
解型樹脂粉体(B)を得るためのエマルション樹脂の酸
価が40より低いものを用いると噴霧乾燥時に噴霧乾燥
装置内への付着や樹脂同士のブロッキングが発生しやす
いため、高酸価のエマルション樹脂を用いることが好ま
しい。乾燥温度条件としては、噴霧乾燥塔のエマルショ
ン噴霧口と粉体出口の温度差を大きくすることが、エマ
ルション樹脂の乾燥効率が良好となることから好まし
い。本発明の再分散可能な樹脂を再分散させるのに用い
る分散媒は、再分散液がアルカリ性条件下になるよう
に、水あるいはアルカリ性溶媒を任意に選べばよい。The spray drying method for obtaining the water-dispersible resin powder (A) and the water-soluble resin powder (B) of the present invention is not particularly limited, and a commonly used spray dryer is used. Can be done by To obtain the redispersible resin of the present invention, the water-dispersible resin powder (A) and the water-soluble resin powder (B) are separately spray-dried, and then each powder is mixed. There is a method of obtaining it, or a method of mixing the emulsion resin for obtaining the water-dispersible resin powder (A) and the emulsion resin for obtaining the water-soluble resin powder (B) and simultaneously spray-drying. However, in the latter method of simultaneously spray-drying to obtain a redispersible resin, when an emulsion resin having an acid value of less than 40 is used to obtain the water-soluble resin powder (B), spraying is performed during spray drying. It is preferable to use an emulsion resin having a high acid value because adhesion to the inside of a drying device and blocking between resins are likely to occur. As the drying temperature condition, it is preferable to increase the temperature difference between the emulsion spray port and the powder outlet of the spray drying tower because the drying efficiency of the emulsion resin will be good. As the dispersion medium used for redispersing the redispersible resin of the present invention, water or an alkaline solvent may be arbitrarily selected so that the redispersion liquid is under alkaline conditions.
【0019】[0019]
【実施例】以下に、本発明を実施例を用いて説明する。
但し、実施例中の「部」は「重量部」を示す。EXAMPLES The present invention will be described below with reference to examples.
However, "part" in the examples means "part by weight".
【0020】実施例中の評価方法は、以下の通りであ
る。 ・酸価:樹脂1gを中和するのに必要なKOHのmg数
(mgKOH/g) ・噴霧状態:噴霧乾燥機内のアトマイザー出口の噴霧状
態を目視にて観察した。 ○…融着物はなく、霧化が均一 ×…融着物が堆積し、霧化が不均一 ・ブロッキング:噴霧乾燥させた粉体の状態を、電子顕
微鏡(日本電子(株)製;商品名:JSM−5200)
で観察した。 ○…流動性のある粉末で1mm以上の塊がない。 ×…流動性のない粉末で1mm以上の塊が存在する。 ・再分散性:純水150部に樹脂粉体100部を投入
し、150rpm、1分攪拌後の分散状態を目視にて観
察した。 ○…乳白色に分散し、凝集・沈殿物は見られない。 ×…溶解および/又は増粘する。The evaluation methods in the examples are as follows. -Acid value: mg number of KOH necessary to neutralize 1 g of resin (mgKOH / g) -Spray state: The spray state at the atomizer outlet in the spray dryer was visually observed. ○: There is no fused substance and the atomization is uniform. × ... Fused substance is accumulated and the atomization is non-uniform. ・ Blocking: The state of the powder dried by spraying is observed with an electron microscope (manufactured by JEOL Ltd .; trade name: JSM-5200)
Observed at. ◯: Free-flowing powder with no lump of 1 mm or more. X: A powder having no fluidity and having a lump of 1 mm or more. Redispersibility: 100 parts of resin powder was added to 150 parts of pure water, and the dispersion state after stirring at 150 rpm for 1 minute was visually observed. ○: Dispersed in milky white, and no aggregation or precipitate was observed. X: Melts and / or thickens.
【0021】[実施例1] 〈水分散型樹脂粉体(A1)の製造〉2リッターの4つ
口フラスコに、水600部、ポリオキシエチレンノニル
フェニルエーテル(花王(株)製;商品名 エマルゲン
910)8.0部、過硫酸カリウム0.6部を投入し、
窒素ガス置換後、窒素ガス気流下150rpmで攪拌し
つつ、70℃に昇温した。次に、メチルメタクリレート
260部、エチルアクリレート132部、メタクリル酸
8部、ジアルキルスルホコハク酸ナトリウム(花王
(株)製;商品名 ペレックスOTP)5.0部の混合
物を、前記フラスコ中に、3時間で滴下した。その後7
0℃で2時間保持した後、80℃に昇温しさらに2時間
保持し、重合を終了させ、乳白色のエマルション樹脂
(a1)(固形分40.5%、重量平均分子量30万)
を得た。[Example 1] <Production of water-dispersible resin powder (A1)> In a 2-liter four-necked flask, 600 parts of water and polyoxyethylene nonylphenyl ether (manufactured by Kao Corporation; trade name Emulgen) 910) 8.0 parts and 0.6 parts of potassium persulfate were added,
After replacing with nitrogen gas, the temperature was raised to 70 ° C. while stirring at 150 rpm in a nitrogen gas stream. Next, a mixture of 260 parts of methyl methacrylate, 132 parts of ethyl acrylate, 8 parts of methacrylic acid, and 5.0 parts of sodium dialkylsulfosuccinate (manufactured by Kao Corporation; trade name Perex OTP) was placed in the flask for 3 hours. Dropped. Then 7
After holding at 0 ° C. for 2 hours, the temperature was raised to 80 ° C. and held for another 2 hours to terminate the polymerization, and milky white emulsion resin (a1) (solid content 40.5%, weight average molecular weight 300,000).
I got
【0022】このエマルション樹脂(a1)を、噴霧乾
燥装置(大川原加工機(株)製;商品名L−8型)を用
いて、チャンバー入口温度120℃、チャンバー出口温
度70℃、アトマイザー回転数25000rpmに設定
し、噴霧乾燥を行い、水分散型樹脂粉体(A1)を得
た。このときの噴霧状態は良好であり、チャンバー内壁
および搬送管内にエマルション樹脂及び/又は粉体の付
着は見られなかった。得られた粉体(A1)は、Tg
(計算値)46℃、最低造膜温度43℃、平均粒子径3
0μm、水分率2.2%であり、また該粉体(A1)同
士のブロッキングは全く見られなかった。また、この該
粉体(A1)を電子顕微鏡で観察したところ、平均粒子
径が1μm以下の一次粒子が2次凝集して、平均粒子径
が30μm前後の粒子を形成していることがわかった。The emulsion resin (a1) was dried using a spray dryer (Okawara Koki Co., Ltd .; trade name L-8 type) at a chamber inlet temperature of 120 ° C., a chamber outlet temperature of 70 ° C. and an atomizer rotation speed of 25,000 rpm. And spray-dried to obtain a water-dispersible resin powder (A1). At this time, the sprayed state was good, and no adhesion of the emulsion resin and / or powder was observed on the inner wall of the chamber and the inside of the transfer pipe. The obtained powder (A1) has Tg
(Calculated value) 46 ° C, minimum film forming temperature 43 ° C, average particle size 3
It was 0 μm, the water content was 2.2%, and blocking between the powders (A1) was not observed at all. Further, when the powder (A1) was observed with an electron microscope, it was found that primary particles having an average particle diameter of 1 μm or less were secondary-aggregated to form particles having an average particle diameter of about 30 μm. .
【0023】〈水溶解型樹脂粉体(B1)の製造〉2リ
ッターの4つ口フラスコに、水800部、ポリビニール
アルコール(けん化度88%、重合度1000)1.0
部を溶解させた。次に、メチルメタクリレート208
部、ノルマルブチルアクリレート168部、メタクリル
酸24部、ノルマルドデシルメルカプタン6.0部に、
アゾビスイソブチロニトリル2.0部を溶解したモノマ
ー溶液を、前記フラスコ中に投入し、窒素ガス置換後、
窒素ガス気流下で激しく攪拌しつつ、80℃で2時間加
熱した。その後90℃に昇温し2時間加熱後、さらに1
20℃に加熱し、残存モノマーを水と共に留去してスラ
リーを得た。得られたスラリーは、濾過、洗浄した後、
50℃の熱風乾燥機で乾燥し、白色粒状粉末のアクリル
樹脂(平均粒子径150μm、重合平均分子量1万、T
g36℃、酸価36mgKOH/g)を得た。この粒状
粉末100部を0.5%水酸化ナトリウムのアルカリ水
溶液900部中に投入し、60℃に加温して、完全に溶
解させ、透明なポリマー溶液(b1)とした。該溶液
(b1)を、噴霧乾燥装置(大川原加工機(株)製;商
品名L−8型)を用いて、チャンバー入口温度120
℃、出口温度60℃、アトマイザー回転数30000r
pmに設定し、噴霧乾燥を行い、白色粒状粉末の水溶解
型樹脂粉体(B1)を得た。<Production of Water-Soluble Resin Powder (B1)> In a 2-liter four-necked flask, 800 parts of water and 1.0 part of polyvinyl alcohol (saponification degree 88%, polymerization degree 1000) 1.0
The parts were dissolved. Next, methyl methacrylate 208
Parts, 168 parts of normal butyl acrylate, 24 parts of methacrylic acid, 6.0 parts of normal dodecyl mercaptan,
A monomer solution in which 2.0 parts of azobisisobutyronitrile was dissolved was put into the flask, and after nitrogen gas replacement,
It heated at 80 degreeC for 2 hours, stirring violently under nitrogen gas stream. After that, the temperature is raised to 90 ° C., and after heating for 2 hours, further 1
It heated at 20 degreeC and distilled off the residual monomer with water, and obtained the slurry. The resulting slurry is filtered and washed,
Drying with a hot air dryer at 50 ° C., white granular powder acrylic resin (average particle size 150 μm, polymerization average molecular weight 10,000, T
g36 ° C., acid value 36 mg KOH / g) was obtained. 100 parts of this granular powder was put into 900 parts of an aqueous solution of 0.5% sodium hydroxide, heated to 60 ° C., and completely dissolved to obtain a transparent polymer solution (b1). The solution (b1) was heated at a chamber inlet temperature of 120 using a spray dryer (Okawara Koki Co., Ltd .; trade name L-8 type).
℃, outlet temperature 60 ℃, atomizer rotation speed 30000r
It was set to pm and spray-dried to obtain a water-soluble resin powder (B1) as white granular powder.
【0024】このように前記アクリル樹脂をさらに水に
溶解して噴霧乾燥するのは、白色粒状粉末の一次粒子径
が150μmもあり、再分散後の水溶解速度が遅く、ま
た分散安定性が不良となるため、一次粒子の細かい粉体
を得るためである。噴霧状態は、良好で、チャンバー内
壁および搬送管内に付着は見られず、得られた粉体の平
均粒子径は30μm、水分率2.2%で、ブロッキング
は全く見られなかった。Thus, the acrylic resin is further dissolved in water and spray-dried because the primary particle diameter of the white granular powder is 150 μm, the water dissolution rate after redispersion is slow, and the dispersion stability is poor. Therefore, it is for obtaining a powder having fine primary particles. The sprayed state was good, no adhesion was observed on the inner wall of the chamber and the inside of the transfer tube, the average particle size of the obtained powder was 30 μm, the water content was 2.2%, and no blocking was observed at all.
【0025】〈再分散液の製造〉上記水分散型樹脂粉体
(A1)50部と水溶解型樹脂粉体(B1)50部を混
合した再分散性樹脂を、純水150部中に投入して再分
散液を得たところ、再分散性は良好であり、この再分散
液の最低造膜温度は15℃であった。<Production of Redispersion Liquid> A redispersible resin obtained by mixing 50 parts of the water-dispersible resin powder (A1) and 50 parts of the water-soluble resin powder (B1) is put into 150 parts of pure water. As a result, a redispersion liquid was obtained, and the redispersibility was good, and the minimum film forming temperature of this redispersion liquid was 15 ° C.
【0026】[実施例2] 〈水分散型樹脂粉体(B2)の製造〉2リッターの4つ
口フラスコに、水600部、脂肪酸ソーダ石鹸(花王
(株)製;商品名 フレークマルセル)4.0部、過硫
酸カリウム1.2部を投入し、窒素ガス置換した後、窒
素ガス気流下、150rpmで攪拌しつつ、70℃に昇
温する。次に、メチルメタクリレート180部、ノルマ
ルブチルアクリレート140部、メタクリル酸80部、
ノルマルドデシルメルカプタン6部、ジアルキルスルホ
コハク酸ナトリウム(花王(株)製;商品名 ペレック
スOTP)6.0部の混合物を3時間で滴下し、70℃
で2時間保持した後、80℃に昇温し2時間保持し重合
を終了させ、乳白色のエマルション樹脂(b2)(固形
分40.3%、重量平均分子量15万)を得た。[Example 2] <Production of water-dispersible resin powder (B2)> 600 parts of water and fatty acid soda soap (Kao Corporation; trade name: Flake Marcel) 4 in a 2-liter four-necked flask. After adding 0.0 part and 1.2 parts of potassium persulfate and substituting with nitrogen gas, the temperature was raised to 70 ° C. while stirring at 150 rpm in a nitrogen gas stream. Next, 180 parts of methyl methacrylate, 140 parts of normal butyl acrylate, 80 parts of methacrylic acid,
A mixture of 6 parts of normal dodecyl mercaptan and 6.0 parts of sodium dialkylsulfosuccinate (manufactured by Kao Corporation; trade name Perex OTP) was added dropwise over 3 hours at 70 ° C.
After the temperature was maintained for 2 hours, the temperature was raised to 80 ° C. and the temperature was maintained for 2 hours to terminate the polymerization to obtain a milky white emulsion resin (b2) (solid content 40.3%, weight average molecular weight 150,000).
【0027】このエマルション樹脂(b2)を噴霧乾燥
装置(大川原加工機社製;商品名L−8型)を用いて、
チャンバー入口温度120℃、出口温度70℃、アトマ
イザー回転数25000rpmに設定し、噴霧乾燥行
い、水溶解型樹脂粉体(B2)を得た。噴霧状態は良好
で、チャンバー内壁及び搬送管内に付着は見られず、得
られた粉体は、Tg(計算値)43℃、酸価120mg
KOH/g、平均粒子径26μm、水分率2.0%であ
り、ブロッキングは全く見られなかった。This emulsion resin (b2) was used in a spray dryer (Okawara Koki Co., Ltd .; trade name L-8 type).
The chamber inlet temperature was 120 ° C., the outlet temperature was 70 ° C., the atomizer rotation speed was 25,000 rpm, and spray drying was performed to obtain a water-soluble resin powder (B2). The atomized state was good, no adhesion was found on the inner wall of the chamber and the transfer pipe, and the obtained powder had a Tg (calculated value) of 43 ° C. and an acid value of 120 mg.
KOH / g, average particle diameter 26 μm, water content 2.0%, no blocking was observed.
【0028】〈再分散液の製造〉上記水分散型樹脂粉体
(A1)50部と水溶解型樹脂粉体(B2)50部を混
合したものを、0.5%水酸化ナトリウム水溶液150
部中に投入し再分散液を得たところ、再分散性は良好で
あり、この再分散液の最低造膜温度は7℃であった。<Production of Redispersion Liquid> A mixture of 50 parts of the water-dispersible resin powder (A1) and 50 parts of the water-soluble resin powder (B2) was mixed with 0.5% aqueous sodium hydroxide solution 150.
When the redispersion liquid was obtained by throwing it into the chamber, the redispersibility was good, and the minimum film forming temperature of this redispersion liquid was 7 ° C.
【0029】[実施例3,4、比較例1〜3]実施例1
と同様の手法により、表1に示す水分散型樹脂粉体(A
2),(A3)および水溶解型樹脂粉体(B3)〜(B
5)を得た。各々のエマルション樹脂の噴霧乾燥状態、
及び得られた粉体(A),(B)のブロッキング性を表
1に示す。但し、粉体(A3)、(B4)は、噴霧乾燥
時にアトマイザー口にエマルション樹脂の融着物が堆積
し、粉体が得られなかったため、再分散性および最低造
膜温度を評価できなかった。[Examples 3 and 4, Comparative Examples 1 to 3] Example 1
A water-dispersible resin powder (A
2), (A3) and water-soluble resin powders (B3) to (B)
5) was obtained. Spray dried state of each emulsion resin,
Table 1 shows the blocking properties of the obtained powders (A) and (B). However, the powders (A3) and (B4) could not be evaluated for redispersibility and the minimum film-forming temperature, because a fusion product of the emulsion resin was deposited at the atomizer port during spray drying and no powder was obtained.
【0030】[0030]
【表1】 表中の記号は、以下の通りである。 MMA:メチルメタクリレート EA:エチルアクリレート BA:ブチルアクリレート MAA:メタクリル酸[Table 1] The symbols in the table are as follows. MMA: Methyl Methacrylate EA: Ethyl Acrylate BA: Butyl Acrylate MAA: Methacrylic Acid
【0031】これら樹脂粉体を表2に示した配合比に混
合し、再分散性と最低造膜温度を測定した。その結果を
表2に示す。These resin powders were mixed at the compounding ratio shown in Table 2 and the redispersibility and the minimum film forming temperature were measured. The results are shown in Table 2.
【0032】[0032]
【表2】 [Table 2]
【0033】実施例3,4とも、再分散性が良好であ
り、粉体同士のブロッキングがなく、20℃以下の最低
造膜温度を有する性能を発現している。比較例1は、水
溶解型樹脂粉体(B5)の酸価が25mgKOH/gで
あるため、混合した再分散可能な樹脂の分散性は良好な
ものの、最低造膜温度が20℃以下とならなかった。比
較例2は、水溶解型樹脂粉体(B)を用いなかったた
め、最低造膜温度の低下が見られなかった。比較例3
は、水分散型樹脂粉体(A)を用いなかったため、再分
散樹脂の形態を発現できず、高粘度の水溶性樹脂となっ
た。In each of Examples 3 and 4, the redispersibility is good, there is no blocking between the powder particles, and the performance of having the minimum film forming temperature of 20 ° C. or lower is exhibited. In Comparative Example 1, since the acid value of the water-soluble resin powder (B5) is 25 mgKOH / g, the redispersibility of the mixed redispersible resin is good, but the minimum film-forming temperature is 20 ° C. or lower. There wasn't. In Comparative Example 2, since the water-soluble resin powder (B) was not used, the minimum film forming temperature did not decrease. Comparative Example 3
Since the water-dispersible resin powder (A) was not used, the form of the redispersed resin could not be expressed and the water-soluble resin had a high viscosity.
【発明の効果】以上詳述したように、本発明の方法によ
り、アルカリ性条件下において20℃以下の最低造膜温
度を有する再分散液を得ることができる、耐ブロッキン
グ性が良好な再分散可能な樹脂を噴霧乾燥により効率よ
く得ることが可能となり、特に、塗料等のコーティング
材料用樹脂として好適である。As described in detail above, according to the method of the present invention, it is possible to obtain a redispersion liquid having a minimum film-forming temperature of 20 ° C. or less under alkaline conditions, and redispersion having good blocking resistance. Such a resin can be efficiently obtained by spray drying, and is particularly suitable as a resin for coating materials such as paints.
Claims (2)
15℃以上である水分散型樹脂粉体(A)と、噴霧乾燥
により得られたガラス転移温度が15℃以上で且つ酸価
が30mgKOH/g以上である水溶解型樹脂粉体
(B)とを含むことを特徴とする再分散可能な樹脂。1. A water-dispersible resin powder (A) having a glass transition temperature of 15 ° C. or higher obtained by spray drying, and a glass transition temperature of 15 ° C. or higher and an acid value of 30 mgKOH obtained by spray drying. / G or more of the water-soluble resin powder (B), which is a redispersible resin.
た再分散液の最低造膜温度が、20℃以下であることを
特徴とする、請求項1記載の再分散可能な樹脂。2. The redispersible resin according to claim 1, wherein the redispersion liquid dispersed in water has a minimum film forming temperature of 20 ° C. or lower under alkaline conditions.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP27963894A JPH08134224A (en) | 1994-11-15 | 1994-11-15 | Redispersible resin |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP27963894A JPH08134224A (en) | 1994-11-15 | 1994-11-15 | Redispersible resin |
Publications (1)
Publication Number | Publication Date |
---|---|
JPH08134224A true JPH08134224A (en) | 1996-05-28 |
Family
ID=17613774
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP27963894A Pending JPH08134224A (en) | 1994-11-15 | 1994-11-15 | Redispersible resin |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPH08134224A (en) |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP1036832A1 (en) * | 1999-03-16 | 2000-09-20 | Polymar GmbH | Pulverulent concentrate for the production of aqueous dispersion coatings and varnishes |
WO2001088021A1 (en) * | 2000-05-19 | 2001-11-22 | Mitsubishi Rayon Co., Ltd. | Process for producing acrylic polymer |
US11746251B2 (en) | 2014-03-05 | 2023-09-05 | Ppg Industries Ohio, Inc. | Chemical agent resistant coating compositions |
-
1994
- 1994-11-15 JP JP27963894A patent/JPH08134224A/en active Pending
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP1036832A1 (en) * | 1999-03-16 | 2000-09-20 | Polymar GmbH | Pulverulent concentrate for the production of aqueous dispersion coatings and varnishes |
WO2001088021A1 (en) * | 2000-05-19 | 2001-11-22 | Mitsubishi Rayon Co., Ltd. | Process for producing acrylic polymer |
US11746251B2 (en) | 2014-03-05 | 2023-09-05 | Ppg Industries Ohio, Inc. | Chemical agent resistant coating compositions |
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