JPH0718005A - Production of vinyl chloride polymer - Google Patents
Production of vinyl chloride polymerInfo
- Publication number
- JPH0718005A JPH0718005A JP18688693A JP18688693A JPH0718005A JP H0718005 A JPH0718005 A JP H0718005A JP 18688693 A JP18688693 A JP 18688693A JP 18688693 A JP18688693 A JP 18688693A JP H0718005 A JPH0718005 A JP H0718005A
- Authority
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- Japan
- Prior art keywords
- polymerization
- temperature
- vinyl chloride
- polymerization vessel
- vessel
- 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.)
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Abstract
Description
【0001】[0001]
【産業上の利用分野】本発明は塩化ビニル系重合体の製
造方法に関する。TECHNICAL FIELD The present invention relates to a method for producing a vinyl chloride polymer.
【0002】[0002]
【従来の技術】一般に、塩化ビニル又は塩化ビニルを含
む単量体混合物(以下、塩化ビニル等という。)の懸濁
重合は、例えば、ジャケット及び還流コンデンサを備え
た重合器中に水性媒体、分散剤(懸濁剤)及び重合開始
剤を仕込み、次に重合器内を排気して前記単量体を仕込
み、更に必要に応じてその他各種添加剤を仕込んだ後、
ジャケットに熱水を通して重合器内を所定の重合反応温
度になるまで昇温し、続いてジャケット及び還流コンデ
ンサに冷却水を通して重合反応熱を除去することにより
重合器内を所定の反応温度に保持しながら重合反応を行
わせる、という方法により実施されている。2. Description of the Related Art Generally, suspension polymerization of vinyl chloride or a monomer mixture containing vinyl chloride (hereinafter referred to as vinyl chloride etc.) is carried out, for example, in an aqueous medium, dispersion in a polymerization vessel equipped with a jacket and a reflux condenser. After charging the agent (suspension agent) and the polymerization initiator, then evacuating the inside of the polymerization vessel and charging the above monomer, and further charging various other additives as necessary,
The inside of the polymerization vessel is maintained at a predetermined reaction temperature by passing hot water through the jacket to raise the temperature inside the polymerization vessel to a predetermined polymerization reaction temperature and then passing cooling water through the jacket and the reflux condenser to remove the heat of the polymerization reaction. While carrying out the polymerization reaction, it is carried out.
【0003】塩化ビニル等を懸濁重合して塩化ビニル系
重合体を製造する場合、重合反応温度を高くする程重合
度の低い塩化ビニル系重合体が得られる。従って、平均
重合度1000以下の、特に平均重合度 800以下の塩化ビニ
ル系重合体を製造する場合には、通常、重合反応温度を
58℃以上とする必要がある。When a vinyl chloride polymer is produced by suspension polymerization of vinyl chloride or the like, the higher the polymerization reaction temperature, the lower the degree of polymerization of the vinyl chloride polymer. Therefore, when producing a vinyl chloride polymer having an average degree of polymerization of 1000 or less, particularly 800 or less, the polymerization reaction temperature is usually
It must be above 58 ℃.
【0004】また、近年、生産性を向上するために重合
時間の短縮化が図られている。重合時間の短縮化の方法
の一つとして重合開始剤を多量に仕込む方法がある。か
かる方法による場合、昇温時間を短縮し、単位時間当た
りの発熱量をほぼ一定とするために低温活性の重合開始
剤と高温活性の重合開始剤(重合反応温度が58℃以上の
場合、ベンゼン中 0.1mol/L 濃度における10時間半減期
温度が55℃以上の高温活性の重合開始剤) とを併用して
重合反応による発熱の調整を行っている。In recent years, the polymerization time has been shortened in order to improve the productivity. One of the methods for shortening the polymerization time is to charge a large amount of a polymerization initiator. In the case of such a method, in order to shorten the heating time and make the calorific value per unit time almost constant, a low-temperature active polymerization initiator and a high-temperature active polymerization initiator (when the polymerization reaction temperature is 58 ° C or higher, benzene is used). The heat generation due to the polymerization reaction is adjusted in combination with a high-temperature active polymerization initiator with a 10-hour half-life temperature of 55 ° C or higher at a medium concentration of 0.1 mol / L.
【0005】上記のように低温活性の重合開始剤と高温
活性の重合開始剤を併用する場合、低温活性の重合開始
剤の使用割合が多すぎると昇温終了時に発熱が集中す
る。そこで、昇温終了時の発熱の集中を防止するために
重合の初期段階における除熱能力を高める必要がある。
ところが、重合反応開始後、重合転化率が低い時期に還
流コンデンサを使用すると、得られる重合体に粗粒が発
生する等の不都合があるため、かかる時期に還流コンデ
ンサを使用することができず、除熱能力不足により反応
混合物を所定温度に維持することが困難となり反応が暴
走するという危険性がある。従って、低温活性の重合開
始剤と高温活性の重合開始剤を併用する場合には、高温
活性の重合開始剤の使用割合を高くする必要がある。When the low temperature active polymerization initiator and the high temperature active polymerization initiator are used in combination as described above, if the use ratio of the low temperature active polymerization initiator is too large, heat generation is concentrated at the end of the temperature rise. Therefore, in order to prevent the concentration of heat generation at the end of temperature rise, it is necessary to enhance the heat removal capacity in the initial stage of polymerization.
However, after the start of the polymerization reaction, if the reflux condenser is used at a time when the polymerization conversion rate is low, there are disadvantages such as generation of coarse particles in the obtained polymer, so that the reflux condenser cannot be used at such time, There is a risk that it becomes difficult to maintain the reaction mixture at a predetermined temperature due to insufficient heat removal ability, and the reaction will run out. Therefore, when a low temperature active polymerization initiator and a high temperature active polymerization initiator are used in combination, it is necessary to increase the use ratio of the high temperature active polymerization initiator.
【0006】[0006]
【発明が解決しようとする課題】しかしながら、重合反
応温度が58℃以上と高く、かつ、ベンゼン中 0.1mol/L
濃度における10時間半減期温度が55℃以上の高温活性の
重合開始剤の使用割合を高くして重合を行った場合、特
に、内容積40m3 以上の大型重合器を使用した場合にお
いて、重合器内液相部へのスケールの付着量が多くなる
ためスケール除去作業の頻度が増加し、更に、得られる
重合体をシート等に成形した場合にフィッシュアイが増
大して品質が低下するという不都合がある。[Problems to be Solved by the Invention] However, the polymerization reaction temperature is as high as 58 ° C. or higher, and the concentration is 0.1 mol / L in benzene.
When the polymerization is carried out with a high use ratio of a high-temperature active polymerization initiator having a 10-hour half-life temperature of 55 ° C or higher at a certain concentration, particularly when a large-scale polymerization reactor having an internal volume of 40 m 3 or more is used, Since the amount of scale attached to the inner liquid phase portion increases, the frequency of scale removal work increases, and further, when the obtained polymer is molded into a sheet or the like, fish eyes increase and the quality deteriorates. is there.
【0007】従って、本発明の課題は、高温活性の重合
開始剤の存在下、塩化ビニル等を58℃以上で懸濁重合す
ることからなる塩化ビニル系重合体の製造において、重
合器内のスケールの付着量を低減することができ、ま
た、シート等に成形した場合にフィッシュアイの少ない
成形物を得ることができる高品質の重合体を高い生産性
で製造する方法を提供することにある。Therefore, an object of the present invention is to produce a scale in a polymerization vessel in the production of a vinyl chloride-based polymer, which comprises suspension-polymerizing vinyl chloride or the like at 58 ° C. or higher in the presence of a high-temperature active polymerization initiator. It is an object of the present invention to provide a method for producing a high-quality polymer with high productivity, which can reduce the amount of adhering substances, and can obtain a molded product with less fish eyes when molded into a sheet or the like.
【0008】[0008]
【課題を解決するための手段】一般に、塩化ビニル等を
ベンゼン中 0.1mol/L 濃度における10時間半減期温度が
55℃以上の重合開始剤の存在下、重合反応温度58℃以上
で懸濁重合する場合、重合器内を所定の重合反応温度に
短時間に昇温するためにジャケットに通す熱水の温度を
通常80〜95℃程度と高くしている。特に、内容積40m3
以上の大型重合器を使用する場合、単位体積当たりの反
応混合物に対する伝熱面積の割合が減少して伝熱効率が
低下することから、熱水の温度をより高くしている。し
かしながら、熱水の温度が高すぎると重合器内壁面の最
高到達温度も高くなる。本発明者らは前記重合器内壁面
のスケールの付着性と重合器内壁面の最高到達温度の関
係について検討した結果、該最高到達温度を75℃以下に
制御すれば、重合器内壁面へのスケールの付着を著しく
低減することができることを見出して本発明を完成し
た。[Means for Solving the Problems] Generally, the 10-hour half-life temperature of vinyl chloride or the like at a concentration of 0.1 mol / L in benzene is
When carrying out suspension polymerization at a polymerization reaction temperature of 58 ° C or higher in the presence of a polymerization initiator of 55 ° C or higher, the temperature of the hot water passed through the jacket in order to raise the temperature in the polymerization reactor to the predetermined polymerization reaction temperature in a short time. Normally, it is as high as 80-95 ℃. Especially, the internal volume of 40m 3
When the above-mentioned large-sized polymerization vessel is used, the ratio of the heat transfer area to the reaction mixture per unit volume decreases and the heat transfer efficiency decreases, so the temperature of the hot water is increased. However, if the temperature of the hot water is too high, the maximum temperature reached on the inner wall surface of the polymerization vessel also becomes high. The present inventors have studied the relationship between the adhesion of the scale of the inner wall surface of the polymerization vessel and the highest temperature reached of the inner wall surface of the polymerization vessel, and if the highest temperature is controlled to 75 ° C. or less, The present invention has been completed by finding that the scale adhesion can be significantly reduced.
【0009】本発明は、塩化ビニル又は塩化ビニルを含
む単量体を、重合器内において、ベンゼン中 0.1mol/L
濃度における10時間半減期温度が55℃以上の重合開始剤
の存在下、重合反応温度58℃以上で懸濁重合することか
らなる塩化ビニル系重合体を製造する方法において、前
記重合器の内壁面の最高到達温度を75℃以下、好ましく
は70℃以下に制御することを特徴とする塩化ビニル系重
合体の製造方法を提供する。In the present invention, vinyl chloride or a monomer containing vinyl chloride is added in a polymerization vessel at 0.1 mol / L in benzene.
In the presence of a polymerization initiator having a 10-hour half-life temperature of 55 ° C or higher at a concentration, in the method for producing a vinyl chloride polymer, which comprises suspension polymerization at a polymerization reaction temperature of 58 ° C or higher, the inner wall surface of the polymerization vessel The method for producing a vinyl chloride polymer is characterized by controlling the maximum temperature reached to 75 ° C. or lower, preferably 70 ° C. or lower.
【0010】本発明の製造方法においては、重合開始剤
として、ベンゼン中 0.1mol/L 濃度における10時間半減
期温度が55℃以上の高温活性の重合開始剤を使用する。
かかる高温活性の重合開始剤としては、例えば、t−ブ
チルパーオキシピバレート(ベンゼン中 0.1mol/L 濃度
における10時間半減期温度:55℃)、3,5,5-トリメチル
ヘキサノイルパーオキシド(同59.5℃)、デカノイルパ
ーオキシド(同62℃)、ラウロイルパーオキシド(同62
℃)、ベンゾイルパーオキシド(同74℃)等が挙げられ
る。In the production method of the present invention, a high-temperature active polymerization initiator having a 10-hour half-life temperature of 55 ° C. or higher at a concentration of 0.1 mol / L in benzene is used as the polymerization initiator.
Examples of such a high-temperature active polymerization initiator include t-butylperoxypivalate (10-hour half-life temperature in benzene at a concentration of 0.1 mol / L: 55 ° C.), 3,5,5-trimethylhexanoyl peroxide ( 59.5 ° C), decanoyl peroxide (62 ° C), lauroyl peroxide (62 ° C)
℃), benzoyl peroxide (at the same 74 ℃) and the like.
【0011】また、本発明の製造方法においては、昇温
時間を短縮するために、重合開始剤として、ベンゼン中
0.1mol/L 濃度における10時間半減期温度が55℃以上の
高温活性の重合開始剤と共に、ベンゼン中 0.1mol/L 濃
度における10時間半減期温度が55℃未満、好ましくは50
℃以下、更に好ましくは40〜50℃の低温活性の重合開始
剤を使用するのが好ましい。前記低温活性の重合開始剤
の仕込み量は、通常、前記高温活性の重合開始剤と低温
活性の重合開始剤の仕込み合計量の10〜70重量%であ
り、好ましくは、30〜50重量%である。低温活性の重合
開始剤の使用量が少なすぎると昇温時間を短縮する効果
が小さい。また、低温活性の重合開始剤の使用量が多い
と昇温終了時に発熱が集中するため除熱能力の不足によ
り反応混合物を所定温度に維持することが困難となり、
反応が暴走するという危険がある他、得られる重合体を
シート等の成形物に加工した場合にフィッシュアイが増
加する等の不都合がある。In the production method of the present invention, benzene is used as a polymerization initiator in order to shorten the temperature rising time.
A 10-hour half-life temperature of 0.1 mol / L in benzene is less than 55 ℃, with a high-temperature active polymerization initiator having a 10-hour half-life temperature of 55 ℃ or higher at a concentration of 0.1 mol / L, preferably 50
It is preferable to use a low temperature active polymerization initiator having a temperature of not higher than 0 ° C, more preferably 40 to 50 ° C. The charging amount of the low temperature active polymerization initiator is usually 10 to 70% by weight, preferably 30 to 50% by weight, of the total amount of the high temperature active polymerization initiator and the low temperature active polymerization initiator charged. is there. If the amount of the low-temperature active polymerization initiator used is too small, the effect of shortening the temperature raising time is small. Further, when the amount of the low-temperature active polymerization initiator used is large, heat generation is concentrated at the end of the temperature rise, making it difficult to maintain the reaction mixture at a predetermined temperature due to lack of heat removal capability,
There is a risk that the reaction will run away, and there is the inconvenience that when the polymer obtained is processed into a molded product such as a sheet, fish eyes increase.
【0012】上記の低温活性の重合開始剤としては、例
えば、ジ-2- エトキシエチルパーオキシジカーボネート
(ベンゼン中 0.1mol/L 濃度における10時間半減期温
度:43.4℃)、ジ-2- エチルヘキシルパーオキシジカー
ボネート(同43.5℃)、t−ヘキシルパーオキシネオデ
カノエート(同44.7℃)、t−ブチルパーオキシネオデ
カノエート(同46.5℃)等が挙げられる。Examples of the above-mentioned low temperature active polymerization initiator include di-2-ethoxyethyl peroxydicarbonate (10-hour half-life temperature at a concentration of 0.1 mol / L in benzene: 43.4 ° C.) and di-2-ethylhexyl. Peroxydicarbonate (43.5 ° C. in the same), t-hexyl peroxy neodecanoate (44.7 ° C. in the same), t-butyl peroxy neodecanoate (46.5 ° C. in the same) and the like can be mentioned.
【0013】本発明の製造方法において、重合開始剤の
仕込み合計量は、通常、単量体仕込み量の0.02〜0.2 重
量%であり、好ましくは、0.04〜0.1 重量%である。In the production method of the present invention, the total amount of the polymerization initiator charged is usually 0.02 to 0.2% by weight, preferably 0.04 to 0.1% by weight, based on the charged amount of the monomer.
【0014】本発明においては、塩化ビニル等の懸濁重
合は、例えば以下のようにして行う。まず、ジャケット
及び還流コンデンサを備えた重合器内に水、分散剤、重
合開始剤及びその他の各種添加剤を仕込んだ後、重合器
内の気相部を脱気する。次に、重合器内に塩化ビニル等
の単量体を仕込み、重合器内の反応混合物を攪拌しなが
らジャケットに熱水を通じて所定の重合反応温度 (58℃
以上) に昇温する。その際、前記熱水の温度は、重合器
内壁面の最高到達温度が75℃以下となるように設定する
が、通常、65〜70℃程度である。この温度は、従来の熱
水の温度よりも低いため重合器内の昇温時間が長くな
る。そこで、例えば、重合器内にスチームを吹き込んだ
り、重合器内に仕込む水を予め加熱して仕込むことによ
り昇温時間の短縮を図ることが好ましい。In the present invention, suspension polymerization of vinyl chloride or the like is carried out, for example, as follows. First, water, a dispersant, a polymerization initiator, and various other additives are charged into a polymerization vessel equipped with a jacket and a reflux condenser, and then a gas phase portion in the polymerization vessel is deaerated. Next, a monomer such as vinyl chloride is charged into the polymerization vessel, and hot water is passed through the jacket while stirring the reaction mixture in the polymerization vessel to a predetermined polymerization reaction temperature (58 ° C).
Above). At that time, the temperature of the hot water is set so that the highest temperature reached on the inner wall surface of the polymerization vessel is 75 ° C. or lower, but is usually about 65 to 70 ° C. Since this temperature is lower than the temperature of conventional hot water, the temperature rising time in the polymerization vessel becomes long. Therefore, it is preferable to shorten the temperature raising time by, for example, blowing steam into the polymerization vessel or heating the water to be charged into the polymerization vessel in advance.
【0015】重合器内温度が所定の重合反応温度になっ
たら、ジャケットに冷却水を通じて重合反応熱を除去し
ながら重合を行い、所定の収率に達したら、未反応単量
体を回収する。この未反応単量体の回収の際、未反応単
量体の脱離を助けるため、一般的に再度ジャケットに熱
水を通じて加熱する方法が行われている。この場合に
も、重合器内壁面の最高到達温度を75℃以下とすること
によりスケールの付着を低減することができる。未反応
単量体回収後、得られた塩化ビニル系重合体を器外に抜
き出し、脱水乾燥する。When the temperature in the polymerization vessel reaches a predetermined polymerization reaction temperature, cooling water is passed through the jacket to remove the heat of the polymerization reaction to carry out polymerization. When a predetermined yield is reached, unreacted monomers are recovered. At the time of recovering the unreacted monomer, in order to help desorption of the unreacted monomer, a method in which hot water is again passed through the jacket is generally used. Also in this case, the maximum adhesion temperature of the inner wall surface of the polymerization vessel can be set to 75 ° C. or lower to reduce scale adhesion. After recovering the unreacted monomers, the obtained vinyl chloride polymer is taken out of the container and dehydrated and dried.
【0016】本発明の製造方法において、単量体として
は、塩化ビニルを単独で使用することができる他、塩化
ビニルを主体とし、塩化ビニルと共重合可能なコモノマ
ーを含有した単量体混合物(通常、塩化ビニルを50重量
%以上含有)も使用することができる。かかるコモノマ
ーとしては、例えば、酢酸ビニル、プロピオン酸ビニル
等のビニルエステル;例えば、アクリル酸メチル、アク
リル酸エチル等のアクリル酸エステル及びメタクリル酸
エステル;例えば、エチレン、プロピレン等のオレフィ
ン;無水マレイン酸;アクリロニトリル;スチレン;塩
化ビニリデン等が挙げられる。In the production method of the present invention, vinyl chloride may be used alone as a monomer, or a monomer mixture containing vinyl chloride as a main component and a comonomer copolymerizable with vinyl chloride ( Usually, a vinyl chloride content of 50% by weight or more) can also be used. Such comonomers include, for example, vinyl esters such as vinyl acetate and vinyl propionate; acrylic acid esters and methacrylic acid esters such as methyl acrylate and ethyl acrylate; olefins such as ethylene and propylene; maleic anhydride; Acrylonitrile; styrene; vinylidene chloride and the like.
【0017】単量体等の重合体成分を懸濁分散させるた
めに使用する水性媒体の仕込み量は、従来の方法と同
様、単量体との仕込み比(水/単量体)が 1.0〜1.5 程
度でよく、必要に応じて、重合の途中で水を追加するこ
ともできる。The amount of the aqueous medium used for suspending and dispersing the polymer component such as the monomer is the same as in the conventional method, and the charging ratio with the monomer (water / monomer) is 1.0 to. It may be about 1.5, and water may be added during the polymerization, if necessary.
【0018】また重合系(懸濁分散液)の安定化を図る
ために、例えば、ポリビニルアルコール、水溶性及び油
溶性のメチルセルロース、エチルセルロース、ヒドロキ
シエチルセルロース、ヒドロキシプロピルセルロース、
ヒドロキシプロピルメチルセルロース等の水溶性セルロ
ースエーテル、ポリアクリル酸、ゼラチン等の水溶性ポ
リマー、ソルビタンモノラウレート、ソルビタントリオ
レート、ソルビタンモノステアレート、グリセリントリ
ステアレート、エチレンオキシド、プロピレンオキシド
ブロックコポリマー等の油溶性乳化剤;例えば、ポリオ
キシエチレンソルビタンモノラウレート、ポリオキシエ
チレングセリンオレート、ラウリン酸ナトリウム等の水
溶性乳化剤;その他炭酸カルシウム、リン酸カルシウ
ム、ドデシルベンゼンスルホン酸ナトリウム等を、本発
明の目的が損なわれない範囲内で少量使用することがで
きる。In order to stabilize the polymerization system (suspension dispersion), for example, polyvinyl alcohol, water-soluble and oil-soluble methyl cellulose, ethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose,
Water-soluble cellulose ethers such as hydroxypropylmethyl cellulose, water-soluble polymers such as polyacrylic acid and gelatin, oil-soluble polymers such as sorbitan monolaurate, sorbitan trioleate, sorbitan monostearate, glycerin tristearate, ethylene oxide and propylene oxide block copolymers. Emulsifiers; for example, water-soluble emulsifiers such as polyoxyethylene sorbitan monolaurate, polyoxyethylene gucerin oleate, sodium laurate; other calcium carbonate, calcium phosphate, sodium dodecylbenzene sulfonate, etc. without impairing the object of the present invention A small amount can be used within the range.
【0019】本発明の製造方法における重合反応温度は
58℃以上であり、特に、58〜75℃の範囲が好ましい。該
温度が75℃を超えると、重合器の内圧が高くなりすぎて
安全上問題がある等の不都合が生じる場合がある。The polymerization reaction temperature in the production method of the present invention is
It is at least 58 ° C, and particularly preferably in the range of 58 to 75 ° C. If the temperature exceeds 75 ° C., the internal pressure of the polymerization vessel becomes too high, which may cause inconvenience such as a safety problem.
【0020】また、本発明の製造方法は、前記の重合反
応温度で重合を行い、更に連鎖移動剤を使用することに
より、平均重合度1000以下、特に平均重合度 800以下の
低重合度の塩化ビニル系重合体を製造する場合にきわめ
て有効である。前記の連鎖移動剤としては、例えば、有
機メルカプタン類、ハロゲン化炭化水素類、エポキシ基
を有する連鎖状アルキルビニル類等が使用可能である。Further, in the production method of the present invention, the polymerization is carried out at the above-mentioned polymerization reaction temperature, and a chain transfer agent is further used, whereby a low polymerization degree of chloride having an average polymerization degree of 1000 or less, particularly 800 or less is obtained. It is extremely effective when producing a vinyl polymer. As the chain transfer agent, for example, organic mercaptans, halogenated hydrocarbons, chain alkyl vinyls having an epoxy group and the like can be used.
【0021】さらに、必要に応じて、塩化ビニル等の重
合に適宜使用される重合度調節剤、pH調整剤等を重合系
に添加することも任意である。Further, if necessary, it is optional to add a polymerization degree adjusting agent, a pH adjusting agent and the like, which are appropriately used for the polymerization of vinyl chloride and the like, to the polymerization system.
【0022】[0022]
【実施例】実施例1〜5、比較例1〜4 各実施例及び比較例において以下のようにして重合を行
った。内容積が 2.1m3 のステンレススチール製重合器
に、表1に示す温度の脱イオン水 900kgと部分ケン化ポ
リビニルアルコール 760gとを水溶液にして投入した。
重合器内を50mmHgになるまで脱気した後、塩化ビニル単
量体 700kgを仕込んだ。重合器内の反応混合物を撹拌し
ながら、さらに表1に示した量(単量体仕込み量に対す
る割合(重量%))の重合開始剤をポンプで圧入すると
同時にジャケットに表1に示した温度の熱水を通して重
合器内を重合反応温度である61℃に昇温した。尚、表1
には、重合器内壁面の最高到達温度及び昇温時間を示
す。EXAMPLES Examples 1 to 5 and Comparative Examples 1 to 4 Polymerization was carried out as follows in each Example and Comparative Example. 900 kg of deionized water at the temperature shown in Table 1 and 760 g of partially saponified polyvinyl alcohol as an aqueous solution were charged into a stainless steel polymerization vessel having an internal volume of 2.1 m 3 .
After degassing the inside of the polymerization vessel to 50 mmHg, 700 kg of vinyl chloride monomer was charged. While stirring the reaction mixture in the polymerization vessel, a polymerization initiator of the amount shown in Table 1 (percentage (% by weight relative to the charged amount of the monomer)) was pumped in, and at the same time, the temperature of the one shown in Table 1 was introduced into the jacket. The inside of the polymerization vessel was heated to 61 ° C., which is the polymerization reaction temperature, by passing hot water. Table 1
Shows the maximum temperature reached and the temperature rising time of the inner wall surface of the polymerization vessel.
【0023】前記重合器内の温度を61℃に保ちながら重
合反応を行い、昇温を始めて1時間40分後にメルカプト
エタノール 200gを添加した。前記重合器の内圧が 6.0
kg/cm2 Gに達した時点で重合を停止し、未反応単量体
を回収し、得られた重合体をスラリー状で重合器外に抜
き出し、脱水乾燥した。表1には、昇温開始から重合終
了までに要した時間(重合時間)を示す。The polymerization reaction was carried out while maintaining the temperature in the polymerization vessel at 61 ° C., and after 1 hour and 40 minutes from the start of temperature increase, 200 g of mercaptoethanol was added. The internal pressure of the polymerization vessel is 6.0
Polymerization was stopped when the amount reached kg / cm 2 G, unreacted monomers were recovered, and the obtained polymer was taken out of the polymerization vessel in a slurry form and dehydrated and dried. Table 1 shows the time (polymerization time) required from the start of temperature increase to the end of polymerization.
【0024】各実施例及び比較例で得られた塩化ビニル
重合体について、嵩比重、粒度分布、シートに成形した
場合のフィッシュアイの個数を下記の方法で測定した。
その結果を表1に示す。With respect to the vinyl chloride polymers obtained in the respective Examples and Comparative Examples, the bulk specific gravity, particle size distribution, and the number of fish eyes when formed into a sheet were measured by the following methods.
The results are shown in Table 1.
【0025】・嵩比重 JIS K 6721にしたがって測定した。 Bulk density measured according to JIS K 6721.
【0026】・粒度分布 JIS Z 8801に準じた#60、#100 、#200 の各篩を用い
て篩分けし、通過量(重量%)を計量した。 Particle size distribution The particles were sieved using # 60, # 100 and # 200 sieves according to JIS Z 8801, and the passing amount (% by weight) was measured.
【0027】・フィッシュアイ 得られた重合体 100重量部、エポキシ化大豆油 3.0重量
部、セタノール 0.7重量部、ブチルステアレート 1.0重
量部及びスズ系安定剤 2.5重量部をミキサーにて混合し
た後、得られた混合物を20mmの押出機を用いてヘッダー
温度 170℃・ダイス温度 205℃の条件で押出しして、厚
み 0.1mm、巾30mmのシートを50m分取した。得られたシ
ートの1m2 中の白色透明粒子の個数を計数し、フィッ
シュアイの個数とした。 Fisheye After mixing 100 parts by weight of the obtained polymer, 3.0 parts by weight of epoxidized soybean oil, 0.7 parts by weight of cetanol, 1.0 part by weight of butyl stearate and 2.5 parts by weight of tin stabilizer with a mixer, The obtained mixture was extruded using a 20 mm extruder at a header temperature of 170 ° C. and a die temperature of 205 ° C., and a sheet having a thickness of 0.1 mm and a width of 30 mm was taken for 50 m. The number of white transparent particles in 1 m 2 of the obtained sheet was counted and used as the number of fish eyes.
【0028】また、重合終了後の重合器内のスケール付
着状況を観察し、下記の判断基準で評価した。その結果
を表1に示す。 A:スケールの付着がなく金属鏡面の光沢がある。 B:金属鏡面にやや曇りがある。 C:金属表面の一部にスケールが認められる。Further, the scale adhesion state in the polymerization vessel after the completion of the polymerization was observed and evaluated according to the following criteria. The results are shown in Table 1. A: There is no adhesion of scale, and the metallic mirror surface has gloss. B: The metal mirror surface has some cloudiness. C: Scale is recognized on a part of the metal surface.
【0029】[0029]
【表1】 [Table 1]
【0030】実施例6、比較例5 各実施例及び比較例において以下のようにして重合を行
った。内容積が80m3 の還流コンデンサを備えたステン
レススチール製重合器に、表2に示す温度の脱イオン水
37tと部分ケン化ポリビニルアルコール31.5kgとを水溶
液にして投入した。重合器内を50mmHgになるまで脱気し
た後、塩化ビニル単量体29tを仕込んだ。重合器内の反
応混合物を撹拌しながら、さらに表2に示した量(単量
体仕込み量に対する割合(重量%))の重合開始剤をポ
ンプで圧入すると同時にジャケットに表2に示した温度
の熱水を通して重合器内を重合反応温度である61℃に昇
温した。尚、表2には、重合器内壁面の最高到達温度及
び昇温時間を示す。 Example 6 and Comparative Example 5 Polymerization was carried out as follows in each Example and Comparative Example. In a stainless steel polymerization vessel equipped with a reflux condenser with an internal volume of 80 m 3 , add deionized water at the temperature shown in Table 2.
37 t and 31.5 kg of partially saponified polyvinyl alcohol were added as an aqueous solution. After degassing the inside of the polymerization vessel to 50 mmHg, 29 t of vinyl chloride monomer was charged. While stirring the reaction mixture in the polymerization vessel, the amount of the polymerization initiator shown in Table 2 (ratio (% by weight relative to the charged amount of the monomer)) was pumped into the jacket and, at the same time, the temperature at the temperature shown in Table 2 was applied to the jacket. The inside of the polymerization vessel was heated to 61 ° C., which is the polymerization reaction temperature, by passing hot water. In addition, Table 2 shows the maximum reached temperature and the temperature rising time of the inner wall surface of the polymerization vessel.
【0031】前記重合器内の温度を61℃に保ちながら重
合反応を行い、昇温を始めて1時間20分後に還流コンデ
ンサによる除熱を開始し、さらにその20分後にメルカプ
トエタノール 200gを添加した。前記重合器の内圧が
6.0kg/cm2 Gに達した時点で重合を停止し、未反応単
量体を回収し、得られた重合体をスラリー状で重合器外
に抜き出し、脱水乾燥した。表2には、昇温開始から重
合終了までに要した時間(重合時間)を示す。The polymerization reaction was carried out while maintaining the temperature in the polymerization vessel at 61 ° C., and after 1 hour and 20 minutes from the start of heating, heat removal by a reflux condenser was started, and 20 minutes after that, 200 g of mercaptoethanol was added. The internal pressure of the polymerization vessel is
The polymerization was stopped when the amount reached 6.0 kg / cm 2 G, unreacted monomers were recovered, and the obtained polymer was taken out of the polymerization vessel in a slurry form and dehydrated and dried. Table 2 shows the time (polymerization time) required from the start of temperature increase to the end of polymerization.
【0032】各実施例及び比較例で得られた塩化ビニル
重合体について、嵩比重、粒度分布、シートに成形した
場合のフィッシュアイの個数を上記と同様の方法で測定
した。その結果を表2に示す。With respect to the vinyl chloride polymers obtained in the respective Examples and Comparative Examples, the bulk specific gravity, particle size distribution, and the number of fish eyes when formed into a sheet were measured by the same method as described above. The results are shown in Table 2.
【0033】また、重合終了後の重合器内のスケール付
着状況を観察し、上記と同様の判断基準で評価した。そ
の結果を表2に示す。Further, the state of scale adhesion in the polymerization vessel after completion of the polymerization was observed and evaluated according to the same criteria as above. The results are shown in Table 2.
【0034】[0034]
【表2】 [Table 2]
【0035】[0035]
【発明の効果】本発明の塩化ビニル系重合体の製造方法
によれば、重合反応温度が58℃以上と高く、かつ、ベン
ゼン中 0.1mol/L 濃度における10時間半減期温度が55℃
以上の高温活性の重合開始剤の使用割合を高くして重合
を行った場合、特に、内容積40m3 以上の大型の重合器
を使用して重合を行った場合においても、重合器内壁面
へのスケール付着量を低減することができる。従って、
スケール除去作業の頻度が少なくなるので生産性が向上
する。また、本発明の製造方法を適用して重合を行った
場合、シート等に成形した場合にフィッシュアイの少な
い成形物が得られる高品質の低重合度塩化ビニル系重合
体を高い生産性で製造することができる。According to the method for producing a vinyl chloride polymer of the present invention, the polymerization reaction temperature is as high as 58 ° C. or higher, and the 10-hour half-life temperature at a concentration of 0.1 mol / L in benzene is 55 ° C.
Even if the above high-temperature active polymerization initiator is used in a higher proportion, especially when using a large-sized polymerization vessel with an internal volume of 40 m 3 or more, the polymerization vessel inner wall surface It is possible to reduce the amount of adhered scale. Therefore,
Since the frequency of scale removal work is reduced, productivity is improved. Further, when the polymerization is carried out by applying the production method of the present invention, a high-quality low-polymerization vinyl chloride-based polymer with high productivity can be obtained which gives a molded product with less fish eyes when molded into a sheet or the like. can do.
Claims (1)
を、重合器内において、ベンゼン中 0.1mol/L 濃度にお
ける10時間半減期温度が55℃以上の重合開始剤存在下、
重合反応温度58℃以上で懸濁重合することからなる塩化
ビニル系重合体を製造する方法において、前記重合器の
内壁面の最高到達温度を75℃以下に制御することを特徴
とする塩化ビニル系重合体の製造方法。1. A vinyl chloride or a monomer containing vinyl chloride is added in a polymerization vessel in the presence of a polymerization initiator having a 10-hour half-life temperature of 55 ° C. or higher at a concentration of 0.1 mol / L in benzene,
In a method for producing a vinyl chloride-based polymer comprising suspension polymerization at a polymerization reaction temperature of 58 ° C or higher, a vinyl chloride-based polymer characterized in that the maximum temperature reached on the inner wall surface of the polymerization vessel is controlled to 75 ° C or lower. Method for producing polymer.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP18688693A JPH0718005A (en) | 1993-06-30 | 1993-06-30 | Production of vinyl chloride polymer |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP18688693A JPH0718005A (en) | 1993-06-30 | 1993-06-30 | Production of vinyl chloride polymer |
Publications (1)
Publication Number | Publication Date |
---|---|
JPH0718005A true JPH0718005A (en) | 1995-01-20 |
Family
ID=16196409
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP18688693A Pending JPH0718005A (en) | 1993-06-30 | 1993-06-30 | Production of vinyl chloride polymer |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPH0718005A (en) |
-
1993
- 1993-06-30 JP JP18688693A patent/JPH0718005A/en active Pending
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