JP3697803B2 - Vinyl chloride polymer having excellent thermal stability and method for producing the same - Google Patents
Vinyl chloride polymer having excellent thermal stability and method for producing the same Download PDFInfo
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- JP3697803B2 JP3697803B2 JP32664796A JP32664796A JP3697803B2 JP 3697803 B2 JP3697803 B2 JP 3697803B2 JP 32664796 A JP32664796 A JP 32664796A JP 32664796 A JP32664796 A JP 32664796A JP 3697803 B2 JP3697803 B2 JP 3697803B2
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- vinyl chloride
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Description
【０００１】
【発明の属する技術分野】
本発明は、熱安定性に優れる塩化ビニル重合体及びその製造方法に関するものである。
【０００２】
【従来の技術】
従来、塩化ビニル系重合体は、一般的にラジカル重合開始剤を用いた懸濁重合法により製造されており、安価で優れた物理的、機械的性質を有したプラスチックとして多方面の分野で幅広く使用されている。
【０００３】
【発明が解決しようとする課題】
しかしながら、上記のような一般的な方法により得られる塩化ビニル重合体は、そのポリマー構造中に炭素数２個、４個又は長鎖の分岐構造を含んでおり、これらポリマー構造中の分岐構造が塩化ビニル系重合体の熱安定性を著しく低下させることが低分子化合物によるモデル実験から示唆されている。
【０００４】
そして、これらポリマー構造中の分岐構造はラジカル重合過程におけるバックバイティング反応、又はポリマーへの連鎖移動反応により生成することが知られており、上記のような一般的な方法により得られる塩化ビニル重合体は１０００塩化ビニルモノマー単位当たり０．５〜３．０個程度の分岐構造を有していることが報告されている（Ｐｏｌｙｍｅｒ、３５巻、１５２７ページ、１９９４年）。
【０００５】
そして、これまでにポリマー構造中に分岐構造を実質的に含まない熱安定性に優れる高分子量の塩化ビニル重合体に関する知見は得られていない。
【０００６】
そこで、本発明の目的は、熱安定性に優れる塩化ビニル重合体およびその製造方法を提供する事にある。
【０００７】
【課題を解決するための手段】
本発明者らは、上記課題に鑑み鋭意検討した結果、特定の分子量を有し、ポリマー構造中の分岐数が極めて少ない塩化ビニル重合体が従来の塩化ビニル重合体にない優れた熱安定性を有することを見出し本発明を完成するに至った。
【０００８】
すなわち、本発明は、数平均分子量が５０００以上であり、塩化ビニル重合体中の分岐数が１０００塩化ビニルモノマー単位あたり０．３個以下であることを特徴とする熱安定性に優れる塩化ビニル重合体およびその製造方法に関するものである。
【０００９】
以下に、本発明を詳細に説明する。
【００１０】
本発明の塩化ビニル重合体は、ゲルパーミエーションクロマトグラフィーを用いて、ポリエチレングリコール換算で測定したときの数平均分子量が５０００以上のものであり、さらに構造材料として優れた機械的特性を有することから１００００以上のものであるが好ましい。数平均分子量が５０００未満である場合、得られる塩化ビニル重合体の機械的強度及び熱安定性が低下するため、本発明の目的を達成することができない。
【００１１】
本発明の塩化ビニル重合体は、そのポリマー構造中の分岐数が１０００塩化ビニルモノマー単位当たり０．３個以下のものであり、さらに特に優れた熱安定性を有することから１０００塩化ビニルモノマー単位当たり０．１以下であることが好ましい。ポリマー構造中の分岐数が１０００塩化ビニルモノマー単位当たり０．３個を越える場合、得られる塩化ビニル重合体は、従来の塩化ビニルと同程度の熱安定性しか有しないことから本発明の目的を達成することができない。
【００１２】
本発明の塩化ビニル重合体は、数平均分子量が５０００以上であり、塩化ビニル重合体中の分岐数が１０００塩化ビニルモノマー単位あたり０．３個以下であることから従来の塩化ビニル系重合体では得られない熱安定性を有するものである。そして、以下に本発明の熱安定性に優れる塩化ビニル重合体の製造方法の一例を示す。
【００１３】
本発明の塩化ビニル重合体は、有機リチウム／有機アルミニウム化合物からなる重合開始剤を用い、重合温度０℃以上で塩化ビニルモノマーを重合する事により製造できる。
【００１４】
有機リチウム化合物としては、有機リチウム化合物であればいかなるものも使用することができ、数平均分子量の高い塩化ビニル重合体が得られることからｎ−ブチルリチウム、ｓ−ブチルリチウム、ｔ−ブチルリチウムが好ましい。そして、重合開始剤としては、特に熱安定性の向上した塩化ビニル重合体が得られることから有機リチウム化合物／有機アルミニウム化合物＝９９／１〜１／９９（モル比）を用いるものであり、５０／５０〜１／９９であることが特に好ましい。有機アルミニウム化合物としては、有機アルミニウム化合物であればいかなるものも用いることが可能であり、例えばトリエチルアルミニウム、トリブチルアルミニウム、メチルアルミノキサン等が挙げられ、取扱性の容易さからメチルアルミノキサンが特に好ましい。
【００１５】
重合温度は０℃以上であり、重合温度が０℃未満の場合には、塩化ビニルモノマーの重合が進行しない、又は、極めて重合速度が遅く生産性に劣ると言った問題がある。
【００１６】
また、重合反応は、ヘキサン、ヘプタン等の非極性溶媒中又は塊状で、窒素、アルゴン等の不活性雰囲気下又は真空条件下で行うことが好ましい。
【００１７】
本発明の塩化ビニル重合体は、本発明の目的を逸脱しない限りにおいて塩化ビニルモノマーと共重合可能なビニル系単量体を共重合したものであってもよい。塩化ビニルモノマーと共重合可能なビニル系単量体としては、例えばエチレン，プロピレン等のオレフィン化合物、酢酸ビニル，プロピオン酸ビニル等のビニルエステル類、アクリル酸，α−アルキルアクリル酸等の不飽和モノカルボン酸又はそのアルキルエステル類若しくはアミド類、アクリロニトリル等の不飽和ニトリル類、マレイン酸，フマール酸等の不飽和ジカルボン酸類又はそのアルキルエステル類，無水物若しくはＮ−置換マレイミド類、ビニルメチルエーテル，ビニルエチルエーテル等のビニルアルキルエーテル類、各種ビニリデン化合物等が挙げられる。
【００１８】
本発明の塩化ビニル重合体は、熱安定性の優れたものであることから各種成形材料、パイプ、フィルム、シート、コーティング材料など幅広い用途に用いることができる。
【００１９】
また、本発明の塩化ビニル重合体は、必要に応じて公知の帯電防止剤、酸化防止剤、滑剤、可塑剤などを添加する事ができる。
【００２０】
【実施例】
以下に、本発明を実施例により説明するが、本発明は実施例に限定されるものではない。
【００２１】
〜塩化ビニルモノマー〜
塩化ビニルモノマーは、市販品をＣａＨ2上で精製を行った。
【００２２】
〜重合開始剤〜
重合開始剤は市販品をそのまま使用した。
【００２３】
〜重合溶媒〜
重合溶媒は、常法により精製した後使用した。
【００２４】
〜塩化ビニル重合体の収率〜
得られた塩化ビニル重合体の乾燥重量より算出した。
【００２５】
〜塩化ビニル重合体の数平均分子量〜
ゲルパーミエーションクロマトグラフィー（東ソー株式会社製、商品名ＨＬＣ−８０２）を用いジメチルホルムアミドを溶媒とし、ポリエチレングリコール換算により求めた。
【００２６】
〜塩化ビニル重合体の熱分解温度〜
熱天秤（（株）セイコー電子製、商品名ＴＧ／ＤＴＡ２００）を用い、窒素気流中（２００ｍｌ／ｍｉｎ）、２０℃／ｍｉｎで測定した１０％重量減少温度を塩化ビニル重合体の熱分解温度とした。
【００２７】
〜塩化ビニル重合体の分岐数〜
得られた塩化ビニル重合体をＢｕ3ＳｎＨを用い文献記載（Ｐｏｌｙｍｅｒ、３５巻、１５２７ページ、１９９４年）の手法により、ポリエチレン構造に還元処理した後のサンプルを用いて13Ｃ−ＮＭＲスペクトルを測定することにより定量した。
【００３４】
実施例１
ｎ−ヘキサンを溶媒とし、塩化ビニルモノマー３．５２ｍｏｌ／リットル、重合開始剤としてメチルアルミノキサン／ｔ−ブチルリチウム＝５０／５０（ｍｏｌ比）を０．１６８ｍｏｌ／リットル、窒素雰囲気下、０℃、４８時間の重合条件下で重合を行った。
【００３５】
得られた塩化ビニル重合体の収率は８．６％であった。
【００３６】
得られた塩化ビニル重合体の数平均分子量は１００００であり、熱分解温度は３２８度であった。また、得られた塩化ビニル重合体を還元処理したサンプルの分岐数は、１０００塩化ビニルモノマー単位当たり０．１個以下であった。
【００３７】
比較例１
ｎ−ヘキサンを溶媒とし、塩化ビニルモノマー３．５２ｍｏｌ／リットル、ｎ−ブチルリチウム０．１６８ｍｏｌ／リットル、窒素雰囲気下、−７８℃とし、塩化ビニルモノマーの重合をおこなったが塩化ビニル重合体は得られなかった。
【００３８】
比較例２
重合開始剤を一般的なラジカル重合開始剤であるアゾビスイソブチロニトリルとし、重合温度を７０℃、重合時間を６時間とした以外は、実施例１と同様の方法により塩化ビニルの重合を行った。
【００３９】
得られた塩化ビニル重合体の収率は９５％であった。
【００４０】
得られた塩化ビニル重合体の熱分解温度は２５６℃であった。また、得られた塩化ビニル重合体を還元処理したサンプルの分岐数は、１０００塩化ビニルモノマー単位当たり１．８個であった。
【００４１】
比較例３
重合温度を５０℃、重合時間を２時間とした以外は、比較例２と同様の方法により塩化ビニルの重合を行った。
【００４２】
得られた塩化ビニル重合体の収率は３０％であった。
【００４３】
得られた塩化ビニル重合体の熱分解温度は２６５℃であった。また、得られた塩化ビニル重合体を還元処理したサンプルの分岐数は、１０００塩化ビニルモノマー単位当たり０．５個であった。
【００４４】
【発明の効果】
本発明の塩化ビニル重合体は、極めて熱安定性に優れるものであることからその工業的価値は非常に高いものである。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a vinyl chloride polymer having excellent thermal stability and a method for producing the same.
[0002]
[Prior art]
Conventionally, vinyl chloride polymers are generally produced by a suspension polymerization method using a radical polymerization initiator, and are widely used in various fields as low-cost plastics with excellent physical and mechanical properties. It is used.
[0003]
[Problems to be solved by the invention]
However, the vinyl chloride polymer obtained by the general method as described above contains a branched structure of 2, 4 or long carbon atoms in the polymer structure, and the branched structure in these polymer structures is Model experiments with low molecular weight compounds suggest that the thermal stability of vinyl chloride polymers is significantly reduced.
[0004]
The branched structure in these polymer structures is known to be generated by a back-biting reaction in the radical polymerization process or a chain transfer reaction to the polymer, and the vinyl chloride heavy polymer obtained by the general method as described above is used. It is reported that the coalescence has a branched structure of about 0.5 to 3.0 per 1000 vinyl chloride monomer units (Polymer, 35, 1527, 1994).
[0005]
And the knowledge regarding the high molecular weight vinyl chloride polymer excellent in the thermal stability which does not contain a branched structure substantially in a polymer structure until now is not acquired.
[0006]
Accordingly, an object of the present invention is to provide a vinyl chloride polymer having excellent thermal stability and a method for producing the same.
[0007]
[Means for Solving the Problems]
As a result of intensive studies in view of the above problems, the present inventors have found that a vinyl chloride polymer having a specific molecular weight and a very small number of branches in the polymer structure has excellent thermal stability that is not found in conventional vinyl chloride polymers. As a result, the present invention has been completed.
[0008]
That is, the present invention provides a vinyl chloride heavy polymer having excellent thermal stability, wherein the number average molecular weight is 5000 or more and the number of branches in the vinyl chloride polymer is 0.3 or less per 1000 vinyl chloride monomer units. The present invention relates to coalescence and a method for producing the same.
[0009]
The present invention is described in detail below.
[0010]
The vinyl chloride polymer of the present invention has a number average molecular weight of 5000 or more when measured in terms of polyethylene glycol using gel permeation chromatography, and further has excellent mechanical properties as a structural material. It is preferably 10,000 or more. When the number average molecular weight is less than 5,000, the mechanical strength and thermal stability of the resulting vinyl chloride polymer are lowered, so that the object of the present invention cannot be achieved.
[0011]
The vinyl chloride polymer of the present invention has a number of branches in the polymer structure of not more than 0.3 per 1000 vinyl chloride monomer units, and further has excellent thermal stability, so It is preferable that it is 0.1 or less. When the number of branches in the polymer structure exceeds 0.3 per 1000 vinyl chloride monomer units, the resulting vinyl chloride polymer has only the same thermal stability as conventional vinyl chloride, so the object of the present invention is achieved. Cannot be achieved.
[0012]
The vinyl chloride polymer of the present invention has a number average molecular weight of 5000 or more, and the number of branches in the vinyl chloride polymer is 0.3 or less per 1000 vinyl chloride monomer units. It has heat stability that cannot be obtained. And an example of the manufacturing method of the vinyl chloride polymer which is excellent in the thermal stability of this invention below is shown.
[0013]
The vinyl chloride polymer of the present invention can be produced by polymerizing a vinyl chloride monomer at a polymerization temperature of 0 ° C. or higher using a polymerization initiator composed of an organolithium / organoaluminum compound .
[0014]
Any organic lithium compound can be used as long as it is an organic lithium compound, and a vinyl chloride polymer having a high number average molecular weight can be obtained, so that n-butyllithium, s-butyllithium and t-butyllithium are used. preferable. Then, the polymerization initiator, and in particular the use of organolithium compound / organoaluminum compound = 99 / 1-1 / 99 (molar ratio) because the thermal stability improved vinyl chloride polymer obtained, 50 Particularly preferred is / 50 to 1/99. Any organoaluminum compound can be used as long as it is an organoaluminum compound, and examples thereof include triethylaluminum, tributylaluminum, methylaluminoxane, and the like, and methylaluminoxane is particularly preferred because of ease of handling.
[0015]
When the polymerization temperature is 0 ° C. or higher and the polymerization temperature is lower than 0 ° C., there is a problem that the polymerization of the vinyl chloride monomer does not proceed, or the polymerization rate is extremely slow and the productivity is poor.
[0016]
In addition, the polymerization reaction is preferably performed in a nonpolar solvent such as hexane or heptane or in a lump shape under an inert atmosphere such as nitrogen or argon or under vacuum conditions.
[0017]
The vinyl chloride polymer of the present invention may be a copolymer of a vinyl monomer copolymerizable with a vinyl chloride monomer without departing from the object of the present invention. Examples of the vinyl monomer copolymerizable with the vinyl chloride monomer include olefin compounds such as ethylene and propylene, vinyl esters such as vinyl acetate and vinyl propionate, and unsaturated monoesters such as acrylic acid and α-alkylacrylic acid. Carboxylic acids or alkyl esters or amides thereof, unsaturated nitriles such as acrylonitrile, unsaturated dicarboxylic acids such as maleic acid or fumaric acid or alkyl esters thereof, anhydrides or N-substituted maleimides, vinyl methyl ether, vinyl Examples thereof include vinyl alkyl ethers such as ethyl ether and various vinylidene compounds.
[0018]
Since the vinyl chloride polymer of the present invention is excellent in thermal stability, it can be used in a wide range of applications such as various molding materials, pipes, films, sheets and coating materials.
[0019]
In addition, a known antistatic agent, antioxidant, lubricant, plasticizer and the like can be added to the vinyl chloride polymer of the present invention as necessary.
[0020]
【Example】
EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to the examples.
[0021]
~ Vinyl chloride monomer ~
As the vinyl chloride monomer, a commercially available product was purified on CaH 2 .
[0022]
-Polymerization initiator-
A commercially available polymerization initiator was used as it was.
[0023]
~ Polymerization solvent ~
The polymerization solvent was used after being purified by a conventional method.
[0024]
~ Yield of vinyl chloride polymer ~
It calculated from the dry weight of the obtained vinyl chloride polymer.
[0025]
-Number average molecular weight of vinyl chloride polymer-
Using gel permeation chromatography (trade name HLC-802, manufactured by Tosoh Corporation), dimethylformamide was used as a solvent, and the amount was determined in terms of polyethylene glycol.
[0026]
~ Pyrolysis temperature of vinyl chloride polymer ~
Using a thermobalance (trade name TG / DTA200, manufactured by Seiko Denshi Co., Ltd.), the 10% weight loss temperature measured at 20 ° C./min in a nitrogen stream (200 ml / min) is the thermal decomposition temperature of the vinyl chloride polymer. did.
[0027]
-Number of branches of vinyl chloride polymer-
The obtained vinyl chloride polymer was measured for 13 C-NMR spectrum using a sample after reduction treatment to a polyethylene structure using Bu 3 SnH by the method described in the literature (Polymer, 35, 1527, 1994). Quantified.
[0034]
Example 1
Using n-hexane as a solvent, vinyl chloride monomer 3.52 mol / liter, polymerization initiator as methylaluminoxane / t-butyllithium = 50/50 (mol ratio) 0.168 mol / liter, 0 ° C., 48 under nitrogen atmosphere Polymerization was carried out under time polymerization conditions.
[0035]
The yield of the obtained vinyl chloride polymer was 8.6%.
[0036]
The number average molecular weight of the obtained vinyl chloride polymer was 10,000, and the thermal decomposition temperature was 328 degrees. Further, the number of branches of the sample obtained by reducing the obtained vinyl chloride polymer was 0.1 or less per 1000 vinyl chloride monomer units.
[0037]
Comparative Example 1
The vinyl chloride monomer was polymerized by using n-hexane as a solvent, and vinyl chloride monomer was polymerized at 3.52 mol / liter, n-butyllithium 0.168 mol / liter, and nitrogen atmosphere at −78 ° C. to obtain a vinyl chloride polymer. I couldn't.
[0038]
Comparative Example 2
Polymerization of vinyl chloride was carried out in the same manner as in Example 1 except that the polymerization initiator was azobisisobutyronitrile, which is a general radical polymerization initiator, the polymerization temperature was 70 ° C., and the polymerization time was 6 hours. went.
[0039]
The yield of the obtained vinyl chloride polymer was 95%.
[0040]
The thermal decomposition temperature of the obtained vinyl chloride polymer was 256 ° C. Further, the number of branches of the sample obtained by reducing the obtained vinyl chloride polymer was 1.8 per 1000 vinyl chloride monomer units.
[0041]
Comparative Example 3
Vinyl chloride was polymerized in the same manner as in Comparative Example 2 except that the polymerization temperature was 50 ° C. and the polymerization time was 2 hours.
[0042]
The yield of the obtained vinyl chloride polymer was 30%.
[0043]
The thermal decomposition temperature of the obtained vinyl chloride polymer was 265 ° C. Further, the number of branches of the sample obtained by reducing the obtained vinyl chloride polymer was 0.5 per 1000 vinyl chloride monomer units.
[0044]
【The invention's effect】
Since the vinyl chloride polymer of the present invention is extremely excellent in thermal stability, its industrial value is very high.
Claims (2)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP32664796A JP3697803B2 (en) | 1996-12-06 | 1996-12-06 | Vinyl chloride polymer having excellent thermal stability and method for producing the same |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP32664796A JP3697803B2 (en) | 1996-12-06 | 1996-12-06 | Vinyl chloride polymer having excellent thermal stability and method for producing the same |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH10168102A JPH10168102A (en) | 1998-06-23 |
| JP3697803B2 true JP3697803B2 (en) | 2005-09-21 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP32664796A Expired - Fee Related JP3697803B2 (en) | 1996-12-06 | 1996-12-06 | Vinyl chloride polymer having excellent thermal stability and method for producing the same |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3697803B2 (en) |
-
1996
- 1996-12-06 JP JP32664796A patent/JP3697803B2/en not_active Expired - Fee Related
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| Publication number | Publication date |
|---|---|
| JPH10168102A (en) | 1998-06-23 |
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