JP3227216B2 - Dispersion stabilizer for suspension polymerization - Google Patents
Dispersion stabilizer for suspension polymerizationInfo
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- JP3227216B2 JP3227216B2 JP23624792A JP23624792A JP3227216B2 JP 3227216 B2 JP3227216 B2 JP 3227216B2 JP 23624792 A JP23624792 A JP 23624792A JP 23624792 A JP23624792 A JP 23624792A JP 3227216 B2 JP3227216 B2 JP 3227216B2
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- polymerization
- water
- polymer
- degree
- vinyl
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- Addition Polymer Or Copolymer, Post-Treatments, Or Chemical Modifications (AREA)
Description
【０００１】[0001]
【産業上の利用分野】本発明はエチレン性不飽和単量体
の懸濁重合用分散安定剤に関する。更に詳しくは、水お
よび水溶性有機溶媒からなる溶媒中で、エチレン性不飽
和単量体を懸濁重合する際に用いられる分散安定剤に関
する。The present invention relates to a dispersion stabilizer for suspension polymerization of ethylenically unsaturated monomers. More specifically, the present invention relates to a dispersion stabilizer used when suspension-polymerizing an ethylenically unsaturated monomer in a solvent comprising water and a water-soluble organic solvent.
【０００２】[0002]
【従来の技術】エチレン性不飽和単量体の重合体、とり
わけ酢酸ビニル系重合体は接着剤や塗料のベースポリマ
ーとして広範囲に利用されているほか、ビニルアルコー
ル系重合体の原料樹脂として極めて重要なものである。
これらの重合体を懸濁重合により製造する場合には、水
を媒体とした懸濁重合により製造されていた。上記の懸
濁重合において用いられる分散安定剤としては、高級脂
肪酸石ケン、アルキル硫酸塩などのアニオン性界面活性
剤；第四級アンモニウム塩等のカチオン性界面活性剤；
ポリエチレングリコールアルキルエーテル、ポリエチレ
ングリコール脂肪酸エステルなどのノニオン性界面活性
剤；ポリビニルアルコール、ポリアクリル酸塩類、スチ
レン−無水マレイン酸共重合体類、ナフタレンスルホン
酸塩ホルマリン縮合物などの水溶性高分子が代表例であ
る。しかしながら、これらの分散安定剤を、水および水
溶性有機溶媒からなる媒体中で、エチレン性不飽和単量
体を懸濁重合する際に用いると、懸濁粒子の分散安定性
が低く、重合体粒子が凝集する等の問題点があった。2. Description of the Related Art Polymers of ethylenically unsaturated monomers, especially vinyl acetate polymers, are widely used as base polymers for adhesives and paints, and are extremely important as raw material resins for vinyl alcohol polymers. It is something.
When these polymers are produced by suspension polymerization, they have been produced by suspension polymerization using water as a medium. Examples of the dispersion stabilizer used in the above suspension polymerization include anionic surfactants such as higher fatty acid soaps and alkyl sulfates; cationic surfactants such as quaternary ammonium salts;
Nonionic surfactants such as polyethylene glycol alkyl ethers and polyethylene glycol fatty acid esters; water-soluble polymers such as polyvinyl alcohol, polyacrylates, styrene-maleic anhydride copolymers, and naphthalene sulfonate formalin condensates It is an example. However, when these dispersion stabilizers are used for suspension polymerization of an ethylenically unsaturated monomer in a medium composed of water and a water-soluble organic solvent, the dispersion stability of suspended particles is low, There were problems such as aggregation of particles.
【０００３】[0003]
【発明が解決しようとする課題】本発明の目的は、水お
よび水溶性有機溶媒からなる媒体中で、エチレン性不飽
和単量体を懸濁重合する際に用いられる懸濁重合用分散
安定剤を提供することにある。DISCLOSURE OF THE INVENTION An object of the present invention is to provide a dispersion stabilizer for suspension polymerization used in the suspension polymerization of an ethylenically unsaturated monomer in a medium comprising water and a water-soluble organic solvent. Is to provide.
【０００４】[0004]
【課題を解決するための手段】本発明者らは上記課題を
解決するために鋭意検討した結果、水および水溶性有機
溶媒からなる媒体中で、エチレン性不飽和単量体を懸濁
重合する際に用いられるイオン変性ビニルアルコール系
重合体を主成分とする懸濁重合用分散安定剤を見出し、
本発明を完成したものである。Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems, and as a result, have found that an ethylenically unsaturated monomer is subjected to suspension polymerization in a medium comprising water and a water-soluble organic solvent. Found a dispersion stabilizer for suspension polymerization containing an ion-modified vinyl alcohol-based polymer as a main component,
The present invention has been completed.
【０００５】本発明において分散安定剤として使用する
ビニルアルコール系重合体は、分子内に一種類以上のイ
オン基で変性されていることが必須である。イオン基の
種類は、アニオン基及びカチオン基のいずれでもよい
が、好ましくはアニオン基であり、更に好ましくはカル
ボキシル基、スルホン酸基である。イオン基の含量とし
ては０．００１〜５０モル％、より好ましくは０．０１
〜１５モル％、最も好ましくは０．０１〜１０モル％で
ある。イオン基の含量がこれより少ない場合には分散性
が不足し、安定な懸濁重合ができなくなる。また含量が
これより多い場合には懸濁粒子への吸着力が低下するた
め、エチレン性不飽和単量体の重合体の懸濁粒子を安定
に保つことができなくなり、該重合体の粒子の凝集が起
きる場合がある。ビニルアルコール系重合体の平均重合
度についても特に制限はないが、５０〜３００００が好
ましく、５０〜２００００が入手が容易な点からより好
ましい。ビニルアルコール系重合体の平均重合度が３０
０００以上の場合には懸濁液の粘度が高くなり満足な攪
拌が得られにくくなり、またビニルアルコール系重合度
の平均重合度が５０以下の場合には懸濁粒子の安定性が
得られなくなるので好ましくない場合がある。ビニルア
ルコール系重合体のけん化度は、媒体の種類及び量によ
り異なるが、本質的に媒体に溶解する範囲内であれば問
題なく使用でき、好ましくは１０〜１００モル％、より
好ましくは４０〜１００モル％である。また、ビニルア
ルコール系重合体の残存エステル基は、分子鎖に沿って
ブロック状に配列したものであっても、ランダム状に配
列したものであってもよい。ビニルアルコール系重合体
の懸濁重合系への添加量は、エチレン性不飽和単量体の
使用量により異なるが、分散媒１００重量部に対して
０．０００１〜５重量部であり、好ましくは０．００５
〜１重量部、特に好ましくは０．００５〜０．５重量部
である。ビニルアルコール系重合体の使用量が０．００
０１重量部より少ないと、懸濁重合中にビニルエステル
系重合体の粒子を安定に保つことが困難となり、該重合
体の粒子の凝集が起きる場合がある。またビニルアルコ
ール系重合体の使用量が５重量部を超えると、懸濁粒子
の粒径が小さくなりすぎ、懸濁重合系の制御が難しくな
る場合がある。[0005] In the present invention, the vinyl alcohol-based polymer used as a dispersion stabilizer must be modified with one or more ionic groups in the molecule. The type of the ionic group may be either an anionic group or a cationic group, but is preferably an anionic group, and more preferably a carboxyl group or a sulfonic group. The content of the ionic group is 0.001 to 50 mol%, more preferably 0.01 to 50 mol%.
１５15 mol%, most preferably 0.01 to 10 mol%. When the content of the ionic group is less than this, dispersibility becomes insufficient and stable suspension polymerization cannot be performed. If the content is more than this, the adsorbing power to the suspended particles is reduced, so that the suspended particles of the polymer of the ethylenically unsaturated monomer cannot be kept stable, and Agglomeration may occur. The average degree of polymerization of the vinyl alcohol polymer is not particularly limited, but is preferably from 50 to 30,000, more preferably from 50 to 20,000 from the viewpoint of easy availability. The average degree of polymerization of the vinyl alcohol polymer is 30.
If it is more than 000, the viscosity of the suspension becomes high and satisfactory stirring becomes difficult to obtain, and if the average degree of polymerization of the vinyl alcohol-based polymer is 50 or less, the stability of the suspended particles cannot be obtained. Therefore, it may not be preferable. The degree of saponification of the vinyl alcohol-based polymer varies depending on the type and amount of the medium, but can be used without any problem as long as it is essentially within the range of dissolving in the medium, preferably 10 to 100 mol%, more preferably 40 to 100 mol%. Mol%. The residual ester groups of the vinyl alcohol-based polymer may be arranged in blocks along the molecular chain or may be arranged randomly. The amount of the vinyl alcohol-based polymer added to the suspension polymerization system varies depending on the amount of the ethylenically unsaturated monomer used, but is preferably 0.0001 to 5 parts by weight per 100 parts by weight of the dispersion medium, and is preferably 0.005
To 1 part by weight, particularly preferably 0.005 to 0.5 part by weight. The amount of the vinyl alcohol polymer used is 0.00
If the amount is less than 01 parts by weight, it is difficult to keep the particles of the vinyl ester polymer stable during suspension polymerization, and the particles of the polymer may aggregate. If the amount of the vinyl alcohol-based polymer exceeds 5 parts by weight, the particle size of the suspension particles may be too small, and it may be difficult to control the suspension polymerization system.
【０００６】本発明において用いられるエチレン性不飽
和単量体としては、ビニルエステル系単量体及びその他
のビニル系単量体などが挙げられ、ビニルエステル系単
量体としてはギ酸ビニル、酢酸ビニル、プロピオン酸ビ
ニル、バレリン酸ビニル、カプリン酸ビニル、ラウリン
酸ビニル、ステアリン酸ビニル、ピバリン酸ビニル等が
挙げられ、その他のビニル系単量体としては塩化ビニル
などが挙げられ、これらの単量体のなかでも酢酸ビニル
が好ましい。また上記のエチレン性不飽和単量体類と共
重合可能な他のエチレン性不飽和単量体を共重合するこ
とも差し支えなく、これらの単量体としては例えば、
（メタ）アクリル酸、（メタ）アクリル酸エステル、イ
タコン酸またはそのエステル、マレイン酸エステルまた
は無水マレイン酸、（メタ）アクリルアミドまたはこれ
らの誘導体、塩化ビニル、フッ化ビニル、塩化ビニリデ
ン、フッ化ビニリデン、アクリロニトリル、ビニルアル
コキシシラン等が挙げられる。The ethylenically unsaturated monomers used in the present invention include vinyl ester monomers and other vinyl monomers, and the vinyl ester monomers include vinyl formate and vinyl acetate. , Vinyl propionate, vinyl valerate, vinyl caprate, vinyl laurate, vinyl stearate, vinyl pivalate, etc., and other vinyl monomers such as vinyl chloride. Among them, vinyl acetate is preferred. It is also possible to copolymerize other ethylenically unsaturated monomers copolymerizable with the above-mentioned ethylenically unsaturated monomers, and as these monomers, for example,
(Meth) acrylic acid, (meth) acrylic acid ester, itaconic acid or its ester, maleic acid ester or maleic anhydride, (meth) acrylamide or a derivative thereof, vinyl chloride, vinyl fluoride, vinylidene chloride, vinylidene fluoride, Acrylonitrile, vinylalkoxysilane and the like can be mentioned.
【０００７】本発明の媒体は水および水溶性有機溶媒か
らなるため、本発明の分散安定剤を用いた懸濁重合は０
℃以下でも実施可能であり、好ましくは−５０℃以上７
０℃以下であり、より好ましくは−３０℃以上６０℃以
下である。−５０℃未満でも本発明の懸濁重合は実施可
能であるが、媒体中における水溶性有機溶媒の配合割合
が著しく増えるため実用的ではない。本発明の懸濁重合
は通常の高温での懸濁重合に比して次の点で充分な注意
が必要である。すなわち、重合系のラジカル濃度が低い
ために、重合系の酸素や不純物の影響を受け易く、とり
わけ酸素は強烈な禁止剤として作用するため、重合前の
重合系からの除去および重合中の重合系への侵入に関し
てはことさら注意を要する。またエチレン性不飽和単量
体は使用前に、常法により精製するのが好ましい。[0007] Since the medium of the present invention comprises water and a water-soluble organic solvent, suspension polymerization using the dispersion stabilizer of the present invention requires no solvent.
C. or lower, preferably -50.degree.
0 ° C or less, more preferably -30 ° C or more and 60 ° C or less. Although the suspension polymerization of the present invention can be carried out at a temperature lower than -50 ° C, it is not practical because the mixing ratio of the water-soluble organic solvent in the medium is significantly increased. The suspension polymerization of the present invention requires more attention than the ordinary suspension polymerization at high temperature in the following points. That is, since the radical concentration of the polymerization system is low, it is easily affected by oxygen and impurities in the polymerization system.In particular, since oxygen acts as a strong inhibitor, it is removed from the polymerization system before polymerization and the polymerization system during polymerization. Great care must be taken with regard to intrusions into the environment. The ethylenically unsaturated monomer is preferably purified by a conventional method before use.
【０００８】本発明において水と混合して媒体として使
用される水溶性有機溶媒は特に制限はなく、好ましくは
水溶性のアルコール類、グリコール類、グリセリン類、
ジメチルスルホキシド等の水溶性有機溶媒であり、最も
好ましくはメタノール、ジメチルスルホキシドである。
水および水溶性有機溶媒の配合割合は、重合温度によっ
て異なるが、媒体中の水溶性有機溶媒の濃度は５０重量
％以下が好ましく、さらに好ましくは４０重量％以下で
ある。In the present invention, the water-soluble organic solvent used as a medium by mixing with water is not particularly limited, and is preferably a water-soluble alcohol, glycol, glycerin, or the like.
It is a water-soluble organic solvent such as dimethyl sulfoxide, and most preferably methanol and dimethyl sulfoxide.
The mixing ratio of water and the water-soluble organic solvent varies depending on the polymerization temperature, but the concentration of the water-soluble organic solvent in the medium is preferably 50% by weight or less, more preferably 40% by weight or less.
【０００９】[0009]
【実施例】以下実施例を挙げて本発明をさらに詳しく説
明するが、本発明これらによって何ら限定されるもので
はない。なお実施例中の「％」および「部」はいずれも
「重量％」および「重量部」を表す。ビニルエステル系
重合体の平均重合度は、該ビニルエステル系重合体をけ
ん化後、再けん化した酢酸ビニル重合体について、ウベ
ローデ型の粘度計を用いて、アセトン中、３０℃で測定
した極限粘度［η］から次式により求めた粘度平均重合
度（Ｐ）で表したものである。 Ｐ＝（［η］×１０3／７．９４）(1/0.62) EXAMPLES The present invention will be described in more detail with reference to the following Examples, but it should not be construed that the invention is limited thereto. In the examples, “%” and “parts” represent “% by weight” and “parts by weight”, respectively. The average degree of polymerization of the vinyl ester-based polymer is determined by saponifying the vinyl ester-based polymer and re-saponifying the vinyl acetate polymer using an Ubbelohde viscometer in acetone at 30 ° C. at an intrinsic viscosity [ η] and the viscosity average degree of polymerization (P) determined by the following equation. P = ([η] × 10 3 /7.94) (1 / 0.62)
【００１０】実施例１ 攪拌機、温度計、窒素導入管、および冷却管を有する内
容積２０リットルのステンレス製重合器にビニルアルコ
ール／イタコン酸共重合体（重合度２０００、けん化度
８０モル％、イタコン酸ナトリウムの含量２モル％）
０．３部、イオン交換水３０００部およびメタノール６
００部を仕込み、９０℃で、ビニルアルコール／イタコ
ン酸共重合体を溶解した後、窒素を導入しながら６０℃
まで冷却した。常法により精製した酢酸ビニル単量体１
５００部を６０℃で窒素置換した後、窒素を導入しなが
ら２，２´−アゾビスイソブチロニトリル１．２部をす
ばやく溶解し、ビニルアルコール／イタコン酸共重合体
水溶液中に、攪拌しながら投入し重合を始めた。重合中
は窒素ガスでシールし酸素の侵入を抑えた。重合は６０
℃で、速度２５％／時間で進行した。安定に懸濁重合を
行うことができ、３．７時間後に重合率９２％に達した
ところで、重合を停止した。得られた懸濁粒子の平均粒
径は２．５ｍｍであった。重合終了後、生成重合体を重
合器から取り出し、重合器内を水洗した。その後、上記
と同様にして、単量体、該ビニルアルコール／イタコン
酸共重合体等の仕込、重合および重合器内の水洗の操作
を繰り返し、重合器の内壁面に付着した重合体スケール
の量が１ｇ／ｍ2を超えるまでに、行うことのできた重
合回数（スケール付着防止回数という）を測定した結
果、１０回であった。得られた重合体の懸濁液は減圧
下、１５℃で５時間未反応単量体の除去を行い、生成し
たパール状の重合体の濾別および水洗を繰り返し、減圧
下、３０℃で乾燥した。得られた酢酸ビニル重合体の一
部をメタノールに溶解し、濃度６％、アルカリモル比
［ＮａＯＨ／ＶＡｃ］＝０．０５、温度４０℃でけん化
し、得られたビニルアルコール重合体０．１部を、無水
酢酸８部とビリジン２部の混合液中で、１０５℃で２０
時間ときどき攪拌しながら再酢化し、アセトン−エーテ
ル、アセトン−水系で再沈精製を繰り返して得られた酢
酸ビニル重合体の粘度平均重合度は８００であった。ま
た、再酢化して得られた酢酸ビニル重合体を、常法によ
りテトラヒドロフラン系ＧＰＣ分析に供し、重合度分布
を測定したところＭｗ／Ｍｎ＝３．５であった。Example 1 A vinyl alcohol / itaconic acid copolymer (polymerization degree: 2,000, saponification degree: 80 mol%, itacone) was placed in a 20-liter stainless steel polymerization vessel having a stirrer, thermometer, nitrogen introduction pipe, and cooling pipe. (Sodium acid content 2 mol%)
0.3 parts, 3000 parts of ion-exchanged water and 6 parts of methanol
After the vinyl alcohol / itaconic acid copolymer was dissolved at 90 ° C., the mixture was heated to 60 ° C. while introducing nitrogen.
Until cooled. Vinyl acetate monomer 1 purified by a conventional method
After replacing 500 parts with nitrogen at 60 ° C., 1.2 parts of 2,2′-azobisisobutyronitrile was quickly dissolved while introducing nitrogen, and stirred in an aqueous vinyl alcohol / itaconic acid copolymer solution. And polymerization was started. During the polymerization, sealing with nitrogen gas was performed to suppress the invasion of oxygen. Polymerization is 60
C. at a rate of 25% / hour. Suspension polymerization was able to be performed stably, and the polymerization was stopped when the polymerization rate reached 92% after 3.7 hours. The average particle size of the obtained suspended particles was 2.5 mm. After completion of the polymerization, the produced polymer was taken out of the polymerization vessel, and the inside of the polymerization vessel was washed with water. Thereafter, in the same manner as described above, the operations of charging the monomer, the vinyl alcohol / itaconic acid copolymer, etc., polymerizing and washing with water in the polymerization vessel were repeated, and the amount of polymer scale adhered to the inner wall surface of the polymerization vessel was repeated. As a result of measuring the number of times of polymerization (the number of times of preventing scale adhesion) that could be carried out until the value exceeded 1 g / m 2 , it was 10 times. The obtained polymer suspension was subjected to removal of unreacted monomers at 15 ° C. for 5 hours under reduced pressure, and filtration and washing of the formed pearl polymer were repeated, and dried at 30 ° C. under reduced pressure. did. A part of the obtained vinyl acetate polymer was dissolved in methanol, saponified at a concentration of 6%, an alkali molar ratio [NaOH / VAc] = 0.05, and a temperature of 40 ° C. to obtain a vinyl alcohol polymer 0.1. Parts at 105 ° C. in a mixture of 8 parts of acetic anhydride and 2 parts of pyridine.
The vinyl acetate polymer obtained by re-acetylation with occasional stirring and repeated reprecipitation purification with an acetone-ether or acetone-water system had a viscosity-average degree of polymerization of 800. Further, the vinyl acetate polymer obtained by re-acetylation was subjected to tetrahydrofuran-based GPC analysis by a conventional method to measure the degree of polymerization distribution. As a result, Mw / Mn was 3.5.
【００１１】比較例１ 分散安定剤としてポリビニルアルコール（重合度２００
０、けん化度８０モル％、（株）クラレ製のＰＶＡ４２
０）を用いた以外は、実施例１と同様にして重合を開始
した。懸濁重合の状態はたいへん不安定であり、重合速
度が１０％／時間と遅く、２時間後に重合率２０％に達
したところで、重合が停止し、スケール付着防止回数は
１回であった。得られた懸濁粒子の平均粒径は数ｃｍの
粗粒であった。得られた重合体の懸濁液は、減圧下で１
５℃、５時間未反応単量体の除去を行い、生成したパー
ル状の重合体の濾別および水洗を繰り返してから、減圧
下、３０℃乾燥した。次に、実施例１と同様にして、け
ん化後、再酢化して得られた酢酸ビニル重合体の粘度平
均重合度は８５０であり、重合度分布を測定したところ
Ｍｗ／Ｍｎ＝３．２であった。Comparative Example 1 As a dispersion stabilizer, polyvinyl alcohol (polymerization degree 200
0, saponification degree 80 mol%, PVA42 manufactured by Kuraray Co., Ltd.
Polymerization was started in the same manner as in Example 1 except that 0) was used. The state of suspension polymerization was very unstable, and the polymerization rate was as slow as 10% / hour. When the polymerization rate reached 20% after 2 hours, the polymerization was stopped and the number of times of preventing the scale adhesion was once. The average particle size of the obtained suspended particles was coarse particles of several cm. The resulting polymer suspension is concentrated under reduced pressure for 1 hour.
Unreacted monomers were removed at 5 ° C. for 5 hours, and the generated pearl-like polymer was repeatedly filtered and washed with water, and then dried at 30 ° C. under reduced pressure. Next, in the same manner as in Example 1, the viscosity-average polymerization degree of the vinyl acetate polymer obtained by saponification and re-acetylation was 850, and when the polymerization degree distribution was measured, Mw / Mn was 3.2. there were.
【００１２】比較例２ 分散安定剤としてポリビニルアルコール（重合度２００
０、けん化度８０モル％、（株）クラレ製のＰＶＡ４２
０）を用い、分散媒体としてメタノールを添加せずに水
単独を用いた以外は、実施例１と同様にして重合を開始
した。重合速度２５％／時間で安定に懸濁重合を行うこ
とができ、３．６時間後に重合率９０％に達したところ
で、重合を停止した。得られた懸濁粒子の平均粒径は
１．２ｍｍであった。この比較例でのスケール付着防止
回数は９回であった。得られた重合体の懸濁液は、減圧
下で１５℃、５時間未反応単量体の除去を行い、生成し
たパール状の重合体の濾別および水洗を繰り返してか
ら、減圧下、３０℃で乾燥した。次に実施例１と同様に
して、けん化後、再酢化して得られた酢酸ビニル重合体
の粘度平均重合度は１０００であり、重合度分布を測定
したところＭｗ／Ｍｎ＝２．４であった。Comparative Example 2 As a dispersion stabilizer, polyvinyl alcohol (polymerization degree 200
0, saponification degree 80 mol%, PVA42 manufactured by Kuraray Co., Ltd.
Polymerization was started in the same manner as in Example 1 except that water was used alone without adding methanol as a dispersion medium. Suspension polymerization could be stably performed at a polymerization rate of 25% / hour, and when the polymerization rate reached 90% after 3.6 hours, the polymerization was stopped. The average particle size of the obtained suspended particles was 1.2 mm. The scale adhesion prevention frequency in this comparative example was 9 times. The obtained polymer suspension was subjected to removal of unreacted monomers at 15 ° C. for 5 hours under reduced pressure, and repeated filtration and washing with water of the formed pearl-like polymer. Dried at ° C. Next, in the same manner as in Example 1, the viscosity-average degree of polymerization of the vinyl acetate polymer obtained by saponification and re-acetylation was 1000, and when the degree of polymerization distribution was measured, Mw / Mn was 2.4. Was.
【００１３】実施例２ 攪拌機、温度計、窒素導入管および冷却管を有する内容
積２０リットルのステンレス製重合器にビニルアルコー
ル／アリルスルホン酸共重合体（重合度１０００、けん
化度７０モル％、アリルスルホン酸ナトリウムの含量
０．３モル％）０．３部、イオン交換水３０００部およ
びメタノール１０５０部を仕込み、９０℃でビニルアル
コール／アリルスルホン酸共重合体を溶解した後、窒素
を導入しながら−２０℃まで冷却した。常法により精製
した酢酸ビニル単量体１５００部を６０℃で窒素置換し
た後、窒素を導入しながら−２０℃まで冷却し、重合開
始剤としてｔ−ブチルパーオキシド／１−アスコルビン
酸およびｎ−ラルリル酸エステルのレドックス系開始剤
を用い、それぞれ３９／１８部をすばやく溶解し、ビニ
ルアルコール／アリルスルホン酸共重合体水溶液中に、
攪拌しながら投入し重合を始めた。重合中は窒素ガスで
シールし酸素の侵入を抑えた。重合は−２０℃で、重合
速度１５％／時間で進行した。安定に懸濁重合を行うこ
とができ、４．４時間後に重合率６６％に達したところ
で、重合を停止した得られた懸濁粒子の平均粒径は３．
２ｍｍであった。重合終了後、生成重合体を重合器から
取り出し、重合器内を水洗した。その後、上記と同様に
して、単量体、該ビニルアルコール／イタコン酸共重合
体等の仕込、重合および重合器内の水洗の操作を繰り返
し、スケール付着防止回数を測定した結果、８回であっ
た。得られた重合体の懸濁液は減圧下、１５℃で５時間
未反応単量体の除去を行い、生成したパール状の重合体
の濾別および水洗を繰り返してから減圧下、３０℃で乾
燥した。次に、実施例１と同様にして、けん化後、再酢
化して得られた粘度平均重合度は２００００であり、重
合度分布を測定したところＭｗ／Ｍｎ＝４．１であっ
た。Example 2 A vinyl alcohol / allyl sulfonic acid copolymer (polymerization degree: 1000, saponification degree: 70 mol%, allyl :) was placed in a 20-liter stainless steel polymerization vessel having a stirrer, a thermometer, a nitrogen inlet tube and a cooling tube. 0.3 parts by weight of sodium sulfonate), 0.3 part of ion-exchanged water and 1050 parts of methanol were charged, and the vinyl alcohol / allyl sulfonic acid copolymer was dissolved at 90 ° C., and then nitrogen was introduced. Cooled to -20 ° C. After substituting 1500 parts of a vinyl acetate monomer purified by a conventional method with nitrogen at 60 ° C., it was cooled to −20 ° C. while introducing nitrogen, and t-butyl peroxide / 1-ascorbic acid and n- Using a rallylic acid ester redox initiator, 39/18 parts of each were quickly dissolved and dissolved in an aqueous vinyl alcohol / allylsulfonic acid copolymer solution.
The polymerization was started with stirring. During the polymerization, sealing with nitrogen gas was performed to suppress the invasion of oxygen. The polymerization proceeded at −20 ° C. at a polymerization rate of 15% / hour. Suspension polymerization can be stably performed, and when the polymerization rate reaches 66% after 4.4 hours, the average particle diameter of the obtained suspended particles obtained by stopping the polymerization is 3.
2 mm. After completion of the polymerization, the produced polymer was taken out of the polymerization vessel, and the inside of the polymerization vessel was washed with water. Thereafter, in the same manner as described above, the operations of charging the monomer, the vinyl alcohol / itaconic acid copolymer, etc., polymerizing and washing with water in the polymerization vessel were repeated, and the number of times of prevention of scale adhesion was measured. Was. The resulting polymer suspension was subjected to removal of unreacted monomers at 15 ° C. for 5 hours under reduced pressure, and filtration and washing of the formed pearl polymer were repeated, and then at 30 ° C. under reduced pressure. Dried. Next, in the same manner as in Example 1, after saponification and re-acetylation, the viscosity average degree of polymerization obtained was 20,000, and the distribution of the degree of polymerization was measured. As a result, Mw / Mn was 4.1.
【００１４】比較例３ 分散安定剤としてポリビニルアルコール（重合度１００
０、けん化度７０モル％）を用いた以外は、実施例２と
同様にして重合を開始した。懸濁重合の状態は非常に不
安定であり、重合度速度は１％／時間と非常に遅く、５
時間後に重合率５％に達したところで、重合が停止し
た。得られた懸濁粒子の平均粒径は数ｃｍの粗粒であっ
た。また重合器内部のスケールの付着量がたいへん多
く、スケール付着防止回数は０回であった。得られた重
合体の懸濁液は減圧下、１５℃で５時間未反応単量体の
除去を行い、生成したパール状の重合体の濾別および水
洗を繰り返してから、減圧下、３０℃で乾燥した。次
に、実施例１と同様にして、けん化後、再酢化して得ら
れた酢酸ビニル重合体の粘度平均重合度は３５００であ
り、重合度分布を測定したところＭｗ／Ｍｎ＝３．１で
あった。Comparative Example 3 Polyvinyl alcohol (degree of polymerization 100
Polymerization was started in the same manner as in Example 2 except that 0, a saponification degree of 70 mol%) was used. The state of suspension polymerization is very unstable, and the rate of polymerization degree is very slow at 1% / hour.
After a lapse of time, when the polymerization rate reached 5%, the polymerization was stopped. The average particle size of the obtained suspended particles was coarse particles of several cm. In addition, the amount of scale adhered inside the polymerization vessel was extremely large, and the number of times of scale adhesion prevention was 0. The obtained polymer suspension was subjected to removal of unreacted monomers at 15 ° C. for 5 hours under reduced pressure, and filtration and washing of the formed pearl-like polymer were repeated. And dried. Next, the viscosity average degree of polymerization of the vinyl acetate polymer obtained by saponification and re-acetylation after saponification was 3500 in the same manner as in Example 1, and the distribution of the degree of polymerization was measured. As a result, Mw / Mn was 3.1. there were.
【００１５】[0015]
【発明の効果】本発明の懸濁重合用分散安定剤を用いる
と、水および水溶性有機溶媒からなる媒体中で、エチレ
ン性不飽和単量体を安定に懸濁重合することができ、重
合器内の重合体のスケールの付着量が著しく低下する。
これにより重合器内壁などに重合体スケールを付着させ
ることなく、重合器を繰り返し使用できる。さらに、驚
くべきことに重合度分布の広いエチレン性不飽和単量体
の重合体が得られる。これまでは、重合度分布の広いエ
チレン性不飽和単量体の重合体を得るためには、重合率
を上げるなどの方法があったが、本発明によると、水に
併用する水溶性有機溶媒の種類と量を調節することによ
り任意の重合度分布の重合体を得ることができる。重合
度分布の広い該重合体は、その流動特性が向上し、例え
ば溶融押出製膜法にて製膜する場合に、ダイから押し出
されたウエブが押出直後に収縮し、フィルムの両端の膜
厚が厚くなるいわゆるネッキング現象が起こらないとい
った優れた特徴を有する。さらに、本発明にすると、媒
体として水に水溶性有機溶媒を併用しているために、０
℃以下でも分散媒体の凍結がなく、エチレン性不飽和単
量体を安定に懸濁重合させることが可能なために高重合
度のエチレン性不飽和単量体の重合体が得られる。EFFECT OF THE INVENTION The use of the dispersion stabilizer for suspension polymerization of the present invention enables stable suspension polymerization of ethylenically unsaturated monomers in a medium comprising water and a water-soluble organic solvent. The amount of polymer scale attached in the vessel is significantly reduced.
Thereby, the polymerization vessel can be used repeatedly without causing the polymer scale to adhere to the inner wall of the polymerization vessel. Furthermore, it is surprising that a polymer of an ethylenically unsaturated monomer having a wide polymerization degree distribution can be obtained. Heretofore, in order to obtain a polymer of an ethylenically unsaturated monomer having a wide degree of polymerization distribution, there has been a method of increasing the degree of polymerization, but according to the present invention, a water-soluble organic solvent used in combination with water is used. By adjusting the type and amount of, a polymer having an arbitrary degree of polymerization distribution can be obtained. The polymer having a high degree of polymerization distribution has improved flow characteristics, and, for example, when a film is formed by a melt extrusion film forming method, a web extruded from a die shrinks immediately after extrusion, and a film thickness at both ends of the film is obtained. It has an excellent feature that the so-called necking phenomenon, in which the thickness becomes thicker, does not occur. Further, according to the present invention, water is used in combination with a water-soluble organic solvent as a medium.
Since the dispersion medium is not frozen even at a temperature of not more than ° C and the ethylenically unsaturated monomer can be stably polymerized in suspension, a polymer of an ethylenically unsaturated monomer having a high degree of polymerization can be obtained.
Claims (1)
で、エチレン性不飽和単量体を懸濁重合する際に用いら
れるイオン変性ビニルアルコール系重合体を主成分とす
る懸濁重合用分散安定剤。1. A dispersion for suspension polymerization mainly comprising an ion-modified vinyl alcohol polymer used for suspension polymerization of an ethylenically unsaturated monomer in a medium comprising water and a water-soluble organic solvent. Stabilizer.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP23624792A JP3227216B2 (en) | 1992-09-04 | 1992-09-04 | Dispersion stabilizer for suspension polymerization |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP23624792A JP3227216B2 (en) | 1992-09-04 | 1992-09-04 | Dispersion stabilizer for suspension polymerization |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0680710A JPH0680710A (en) | 1994-03-22 |
| JP3227216B2 true JP3227216B2 (en) | 2001-11-12 |
Family
ID=16997961
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP23624792A Ceased JP3227216B2 (en) | 1992-09-04 | 1992-09-04 | Dispersion stabilizer for suspension polymerization |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3227216B2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| TWI616458B (en) | 2013-08-07 | 2018-03-01 | Kuraray Co., Ltd. | Dispersion stabilizer for suspension polymerization and method for producing vinyl resin |
-
1992
- 1992-09-04 JP JP23624792A patent/JP3227216B2/en not_active Ceased
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0680710A (en) | 1994-03-22 |
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