JPH0359805B2 - - Google Patents

Info

Publication number
JPH0359805B2
JPH0359805B2 JP2962984A JP2962984A JPH0359805B2 JP H0359805 B2 JPH0359805 B2 JP H0359805B2 JP 2962984 A JP2962984 A JP 2962984A JP 2962984 A JP2962984 A JP 2962984A JP H0359805 B2 JPH0359805 B2 JP H0359805B2
Authority
JP
Japan
Prior art keywords
propylene
ethylene
block copolymer
impact resistance
rigidity
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.)
Expired
Application number
JP2962984A
Other languages
Japanese (ja)
Other versions
JPS60174612A (en
Inventor
Tadashi Asanuma
Akira Pponjo
Ikuo Kume
Shinryu Uchikawa
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Mitsui Toatsu Chemicals Inc
Original Assignee
Mitsui Toatsu Chemicals Inc
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Mitsui Toatsu Chemicals Inc filed Critical Mitsui Toatsu Chemicals Inc
Priority to JP2962984A priority Critical patent/JPS60174612A/en
Publication of JPS60174612A publication Critical patent/JPS60174612A/en
Publication of JPH0359805B2 publication Critical patent/JPH0359805B2/ja
Granted legal-status Critical Current

Links

Classifications

    • BPERFORMING OPERATIONS; TRANSPORTING
    • B29WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29BPREPARATION OR PRETREATMENT OF THE MATERIAL TO BE SHAPED; MAKING GRANULES OR PREFORMS; RECOVERY OF PLASTICS OR OTHER CONSTITUENTS OF WASTE MATERIAL CONTAINING PLASTICS
    • B29B9/00Making granules
    • B29B9/10Making granules by moulding the material, i.e. treating it in the molten state
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B29WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29KINDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
    • B29K2023/00Use of polyalkenes or derivatives thereof as moulding material

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Processes Of Treating Macromolecular Substances (AREA)
  • Processing And Handling Of Plastics And Other Materials For Molding In General (AREA)
  • Compositions Of Macromolecular Compounds (AREA)
  • Graft Or Block Polymers (AREA)

Description

【発明の詳細な説明】[Detailed description of the invention]

本発明は、剛性と耐衝撃性のバランスの良好な
プロピレン/エチレンブロツク共重合体の製造方
法に関する。詳しくは、特定の造粒機を用いる方
法に関する。 ポリプロピレンの耐衝撃性を改良するためにプ
ロピレンとエチレンをブロツク共重合する方法は
良く知られており耐衝撃性ポリプロピレンとして
市場に多くの銘柄が供給されている。これらのブ
ロツク共重合体は通常立体規則性触媒を用いて同
一重合系で初めにプロピレン単独重合或は少量の
エチレンとの共重合を行い、次いでエチレン単独
或いはエチレンとプロピレンを共重合することに
よつて得られ、前段と後段の比率或は後段のエチ
レンとプロピレンの共重合をエチレンとプロピレ
ンの量比を変化させた多段重合を行なうなどして
ポリプロピレンの優れた特性である剛性をできる
だけ低下させることなく耐衝撃性を改良すること
が行われているが不充分であるだけでなくブロツ
ク共重合体を連続重合で得ると、いわゆるフイシ
ユアイと呼ばれる不均一な部分が生じ耐衝撃性を
低下させるだけでなく、成形品とした時外観が不
良となる問題がある。これに対して造粒に際し押
出機中に金綱を入れたり、押出機で加えるエネル
ギーを増加させるなどの方法が行われるが、そう
するとフイシユアイは減少するものの、耐衝撃性
特に耐落錘衝撃性が不良になるという問題があつ
た。 本発明者らは上記問題を解決する方法について
鋭意検討した結果、特定の造粒機を用いてプロピ
レン/エチレンブロツク共重合体を造粒すること
によつて剛性と耐衝撃性のバランスの良好なプロ
ピレン/エチレンブロツク共重合体が得られるこ
とを見い出し本発明を完成した。 本発明の目的は、剛性と耐衝撃性のバランスの
良好なプロピレン/エチレンブロツク共重合体を
製造する方法を提供することにある。 本発明は、立体規則性触媒を用いて同一重合系
で初めにプロピレンを重合し次いでエチレン又は
エチレンとプロピレンを重合して得たエチレン含
量が3〜30wt%のプロピレン/エチレンブロツ
ク共重合体パウダーを連続混練部とギヤポンプか
らなる造粒機を用いて造粒することを特徴とする
耐衝撃性と剛性のバランスの良好なプロピレン/
エチレンブロツク共重合体の製造方法に関する。 本発明において、プロピレン/エチレンブロツ
ク共重合体パウダーとしては公知の立体規則性触
媒、目安としてはプロピレン単独で重合してポリ
プロピレンを得た時得られたポリプロピレンパウ
ダーをソツクスレー抽出器で沸騰n−ヘプタンで
6時間抽出して抽出後ポリプロピレン重量/抽出前ポリ
プロピレン重量×100 (%)として算出した沸騰n−ヘプタン抽出残率
が90%以上であるような触媒を用いて初めにプロ
ピレンを重合し、次いでエチレン又はエチレンと
プロピレンを重合して得られたエチレン含量が3
〜30wt%のブロツク共重合体であれば良く用い
る触媒系は問わない。ブロツク共重合体中のエチ
レン含量が3wt%未満では耐衝撃性が不良であ
り、又30wt%より多いと剛性が不良となる。初
めのプロピレンを重合して得る部分は全共重合体
に対して60wt%以上95wt%以下であることが好
ましく60wt%未満では剛性が不良であり95wt%
より多いと耐衝撃性が不良である。初めのプロピ
レンを重合する時光沢、透明性を改良する目的で
少量(プロピレンに対して2wt%以下)のエチレ
ン又はブテン−1を添加し重合することも可能で
ある。エチレン又はエチレンとプロピレンを重合
する部分でのプロピレンとエチレンの反応比は
90/10〜0/100特に好ましくは80/20〜20/80
であり、反応比が該部での好ましい範囲内になる
条件で2段或はそれ以上反応比の異なる共重合段
階を設けることも可能である。例えば80/20の反
応比で重合し次いで20/80の反応比で重合、或は
50/50の反応比で重合し次いで0/100反応比で
重合することなども可能である。 プロピレン/エチレンブロツク共重合体及び上
記各部の分子量としては135℃テトラリン溶液で
測定した極限粘度数で表わしてそれぞれ0.8〜
3.0、0.6〜3.0、1.2〜15程度のものが、共重合体
を成形するに当つて流れ性の点或は成形品の剛性
及び耐衝撃性から考えて好適である。 立体規則性触媒としてはより具体的には、活性
三塩化チタン触媒と有機アルミニウムからなる触
媒或はハロゲン化マグネシウムに四塩化チタン或
は三塩化チタンを担持して得た活性チタン触媒と
有機アルミニウムからなる触媒などが挙げられ
る。 プロピレン/エチレンブロツク共重合を行うに
あたつては、不活性な液状触体を重合媒体として
用いる溶媒重合法、プロピレン自身を液状媒体と
して用いる塊状重合法、或は実質的に液状媒体を
存在させない気相重合法などが採用できる。重合
温度としては常温〜90℃、圧力としては常圧〜50
Kg/m2−ゲージである。 本発明において重要なことは、同一のプロピレ
ン/エチレンブロツク共重合体パウダーを使用し
ても特定の造粒機を用いて造粒することでブロツ
ク共重合体が耐衝撃性と剛性のバランスに優れた
ものが得られるという点にある。 本発明において肝要なのは、プロピレン/エチ
レンブロツク共重合体パウダーを連続混練部とギ
ヤポンプからなる造粒機を用いて造粒することに
ある。即ち、通常の造粒機である押出機を用いた
り連続混練部と押出機を組み合せたもので造粒し
たのでは本発明の目的は達せられない。 本発明において、プロピレン/エチレンブロツ
ク共重体パウダーは抗酸化剤、紫外線吸収剤など
更に必要に応じて核剤などと混合された状態で適
当なフイーダーを用いて造粒機の混練部に導入さ
れ該混練部で溶融混合される。該混練部はシリン
ダー中に2軸スクリユーを設けた構造のものを用
いると比較的小さい混練部で緊密な混合が可能と
なり好ましい。 該混練部の適当な温度は共重合体の分子量或は
エチレン含量によつて異なり特定されないが通常
150〜280℃である。該混練部でのプロピレン/エ
チレンブロツク共重合体の滞留時間は該部の温度
等によつて適当な範囲が変化し特定できないが通
常15〜30秒である。 本発明において、上記混練部で混練された樹脂
は次いでギヤポンプによつてとり出される。ギヤ
ポンプとしては耐熱性のある高粘度のポリマー溶
融物の転送用として数多くのものが市販されてお
りそのまま利用できる。該部の温度はギヤポンプ
の負荷が適当な範囲となるようにプロピレン/エ
チレンブロツク共重合体の分子量、エチレン含量
などに応じ適宜定めれば良い。 本発明において、工業的規模で実施するに好適
な態様としてはギヤポンプの吐出側に適当な形状
のダイを設けダイから出てくるプロピレン/エチ
レンブロツク共重合体をストランドカツター或は
アンダーウオーターカツターで適当な大きさに切
断しペレツト状とすることである。 好適な組み合せのものが例えば株式会社日本製
鋼所製CMP−90(商品名)として入手できる。 一般にポリオレフイン中でもポリプロピレンな
どのポリ−α−オレフインは比較的空気中の酸素
或は紫外線などによつて容易に分解されポリマー
として物性が低下するため抗酸化剤、紫外線吸収
剤などと混合して市場に供する必要があるため、
造粒工程は通常ポリプロピレンを市場に供するに
あたつて必須の工程であり造粒に際して特定の造
粒機を用いるだけで成形用プロピレン/エチレン
ブロツク共重合体を与えることを可能とする本発
明の方法は工業的に極めて価値のあるものであ
る。 以下に実施例を挙げ、さらに本発明の方法を詳
述する。 実施例及び比較例 (1) プロピレン/エチレンブロツク共重合体パウ
ダーの製造。 () 初めにプロピレン単独で重合し、次いで
エチレンとプロピレンを共重合することでエ
チレン含量9.7重量%のブロツク共重合体を
得た(サンプルA) () 初めにプロピレン単独で重合し、次いで
エチレンとプロピレンを共重合することでエ
チレン含量19.5重量%のブロツク共重合体を
得た(サンプルB) () 初めにプロピレン単独で重合し、次いで
エチレンとプロピレンを共重合することでエ
チレン含量19.0%のブロツク共重合体を得た
(サンプルC) (2) プロピレン/エチレンブロツク共重合体の造
粒 (1)で得た3種のプロピレン/エチレンブロツ
ク共重合体パウダーにフエノール系抗酸化剤
(対パウダー2/1000wt比)、ステアリン酸カ
ルシウム(対パウダー1/1000wt比)を混合
し造粒機として押出機D(株式会社日本製鋼所
製90mmφ単軸押出機)(比較例1〜3)、連続混
練部と押出機より構成されるものE(株式会社
日本製鋼所製CIM−90+P150−13AW(商品
名))(比較例4〜6)及び連続混練部とギヤポ
ンプから構成されるものF(株式会社日本製鋼
所製CMP−90(商品名))(実施例1〜3)を用
いて表に示す条件で造粒した。 (3) (2)で得たプロピレン/エチレンブロツク共重
合体を用いて射出成形機で8cm×16cm×2mmの
シートを製造し物性を測定した結果は表に示
す。 各物性は以下の条件で測定した。 メルトフローインデツクス(MFI)(g/
10min) ASTMD1238 曲げ剛性度(Kg/cm2) ASTMD747−63 降伏応力(Kg/cm2) ASTMD638−64T デユポン(Kg・cm/1/2φ″) JISK6718 アイゾツト(ノツチ付)(Kg・cm/cm)
ASTMD256−56
The present invention relates to a method for producing a propylene/ethylene block copolymer having a good balance between rigidity and impact resistance. More specifically, it relates to a method using a specific granulator. The method of block copolymerizing propylene and ethylene to improve the impact resistance of polypropylene is well known, and many brands of impact resistant polypropylene are supplied on the market. These block copolymers are usually produced by first homopolymerizing propylene or copolymerizing it with a small amount of ethylene in the same polymerization system using a stereoregular catalyst, and then by copolymerizing ethylene alone or ethylene and propylene. The rigidity, which is an excellent characteristic of polypropylene, can be reduced as much as possible by performing multi-stage polymerization by changing the ratio of the first stage to the second stage or the copolymerization of ethylene and propylene in the second stage by changing the quantitative ratio of ethylene and propylene. Although attempts have been made to improve the impact resistance, it is not only insufficient, but when block copolymers are obtained by continuous polymerization, non-uniform areas called so-called "fissures" occur, which only reduces the impact resistance. However, there is a problem in that when molded products are made, the appearance is poor. To deal with this, methods such as inserting wire into the extruder during granulation or increasing the energy applied by the extruder are used, but although this reduces the stiffness, the impact resistance, especially the falling weight impact resistance, is poor. There was a problem with becoming. The inventors of the present invention have conducted intensive studies on methods to solve the above problems, and have found that a good balance between rigidity and impact resistance can be achieved by granulating a propylene/ethylene block copolymer using a specific granulator. They discovered that a propylene/ethylene block copolymer could be obtained and completed the present invention. An object of the present invention is to provide a method for producing a propylene/ethylene block copolymer with a good balance of rigidity and impact resistance. The present invention produces a propylene/ethylene block copolymer powder with an ethylene content of 3 to 30 wt% obtained by first polymerizing propylene in the same polymerization system using a stereoregular catalyst and then polymerizing ethylene or ethylene and propylene. A propylene/propylene product with a good balance of impact resistance and rigidity, characterized by being granulated using a granulator consisting of a continuous kneading section and a gear pump.
This invention relates to a method for producing an ethylene block copolymer. In the present invention, the propylene/ethylene block copolymer powder is prepared using a known stereoregular catalyst.As a rough guide, polypropylene powder obtained by polymerizing propylene alone to obtain polypropylene is extracted with boiling n-heptane using a Soxhlet extractor. Propylene is first polymerized using a catalyst that has a boiling n-heptane extraction residue of 90% or more, calculated as polypropylene weight after extraction/polypropylene weight before extraction x 100 (%) after 6 hours of extraction, and then ethylene Or the ethylene content obtained by polymerizing ethylene and propylene is 3
Any catalyst system may be used as long as it is a block copolymer of ~30 wt%. If the ethylene content in the block copolymer is less than 3 wt%, the impact resistance will be poor, and if it is more than 30 wt%, the rigidity will be poor. The initial portion obtained by polymerizing propylene is preferably 60 wt% or more and 95 wt% or less based on the total copolymer, and if it is less than 60 wt%, the rigidity is poor and 95 wt%.
If the amount is more than that, the impact resistance is poor. When polymerizing the initial propylene, it is also possible to add a small amount (2 wt % or less to propylene) of ethylene or butene-1 for the purpose of improving gloss and transparency. The reaction ratio of propylene and ethylene in the part where ethylene or ethylene and propylene are polymerized is
90/10 to 0/100, particularly preferably 80/20 to 20/80
It is also possible to provide two or more copolymerization stages with different reaction ratios under conditions such that the reaction ratio is within the preferred range for this section. For example, polymerization with a reaction ratio of 80/20 and then polymerization with a reaction ratio of 20/80, or
It is also possible to polymerize with a reaction ratio of 50/50 and then with a reaction ratio of 0/100. The molecular weight of the propylene/ethylene block copolymer and each of the above parts is 0.8 to 0.8, respectively, expressed as the intrinsic viscosity measured in a tetralin solution at 135°C.
3.0, 0.6 to 3.0, and 1.2 to 15 are suitable from the viewpoint of flowability when molding the copolymer or the rigidity and impact resistance of the molded product. More specifically, the stereoregular catalyst is a catalyst consisting of an activated titanium trichloride catalyst and an organoaluminum, or an activated titanium catalyst obtained by supporting titanium tetrachloride or titanium trichloride on magnesium halide and an organoaluminum. Examples include catalysts such as Propylene/ethylene block copolymerization can be carried out using a solvent polymerization method using an inert liquid catalyst as a polymerization medium, a bulk polymerization method using propylene itself as a liquid medium, or a method in which no liquid medium is substantially present. Gas phase polymerization method etc. can be adopted. Polymerization temperature: normal temperature to 90℃, pressure: normal pressure to 50℃
Kg/m 2 -gauge. What is important in the present invention is that even if the same propylene/ethylene block copolymer powder is used, by granulating it using a specific granulator, the block copolymer has an excellent balance of impact resistance and rigidity. The point is that you can get what you want. What is important in the present invention is to granulate the propylene/ethylene block copolymer powder using a granulator comprising a continuous kneading section and a gear pump. That is, the object of the present invention cannot be achieved if granulation is performed using an extruder, which is a normal granulator, or a combination of a continuous kneading section and an extruder. In the present invention, the propylene/ethylene block copolymer powder is mixed with an antioxidant, an ultraviolet absorber, and a nucleating agent as necessary, and then introduced into the kneading section of the granulator using an appropriate feeder. They are melted and mixed in the kneading section. It is preferable to use a kneading section having a structure in which a twin-screw is provided in a cylinder because intimate mixing can be achieved in a relatively small kneading section. The appropriate temperature for the kneading section varies depending on the molecular weight or ethylene content of the copolymer and is not specified, but is usually
The temperature is 150-280℃. The residence time of the propylene/ethylene block copolymer in the kneading section cannot be specified since the appropriate range varies depending on the temperature of the section, but it is usually 15 to 30 seconds. In the present invention, the resin kneaded in the kneading section is then taken out by a gear pump. Many gear pumps are commercially available for transferring heat-resistant, high-viscosity polymer melts, and can be used as is. The temperature of this part may be appropriately determined depending on the molecular weight of the propylene/ethylene block copolymer, the ethylene content, etc. so that the load on the gear pump is within a suitable range. In the present invention, in a preferred embodiment to be carried out on an industrial scale, a die of an appropriate shape is provided on the discharge side of the gear pump, and the propylene/ethylene block copolymer coming out from the die is transferred to a strand cutter or an underwater cutter. It is then cut into appropriate sizes and made into pellets. A suitable combination is available, for example, as CMP-90 (trade name) manufactured by Japan Steel Works, Ltd. In general, among polyolefins, poly-α-olefins such as polypropylene are relatively easily decomposed by oxygen in the air or ultraviolet rays, and their physical properties deteriorate as a polymer, so they are mixed with antioxidants, ultraviolet absorbers, etc. before being marketed. Because it is necessary to provide
The granulation process is usually an essential process for putting polypropylene on the market, and the present invention makes it possible to provide a propylene/ethylene block copolymer for molding by simply using a specific granulator for granulation. The method is of great industrial value. Examples are given below to further explain the method of the present invention in detail. Examples and Comparative Examples (1) Production of propylene/ethylene block copolymer powder. () A block copolymer with an ethylene content of 9.7% by weight was obtained by first polymerizing propylene alone, and then copolymerizing ethylene and propylene (Sample A) () First, propylene was polymerized alone, and then ethylene and propylene were copolymerized. A block copolymer with an ethylene content of 19.5% by weight was obtained by copolymerizing propylene (Sample B) () A block copolymer with an ethylene content of 19.0% was obtained by first polymerizing propylene alone and then copolymerizing ethylene and propylene. A copolymer was obtained (Sample C) (2) Granulation of propylene/ethylene block copolymer A phenolic antioxidant (for powder 2) was added to the three types of propylene/ethylene block copolymer powders obtained in (1). /1000wt ratio), calcium stearate (powder 1/1000wt ratio) was mixed, and extruder D (90mmφ single screw extruder manufactured by Japan Steel Works, Ltd.) was used as a granulator (Comparative Examples 1 to 3), continuous kneading section and Type E consisting of an extruder (CIM-90+P150-13AW (product name) made by Japan Steel Works, Ltd.) (Comparative Examples 4 to 6) and Type F consisting of a continuous kneading section and gear pump (Japan Steel Works, Ltd.) CMP-90 (trade name) (Examples 1 to 3) under the conditions shown in the table. (3) Using the propylene/ethylene block copolymer obtained in (2), a sheet of 8 cm x 16 cm x 2 mm was manufactured using an injection molding machine and its physical properties were measured.The results are shown in the table. Each physical property was measured under the following conditions. Melt flow index (MFI) (g/
10min) ASTMD1238 Bending rigidity (Kg/cm 2 ) ASTMD747−63 Yield stress (Kg/cm 2 ) ASTMD638−64T Dupont (Kg・cm/1/2φ″) JISK6718 Izotsu (with notch) (Kg・cm/cm)
ASTMD256−56

【表】【table】

【表】【table】

Claims (1)

【特許請求の範囲】[Claims] 1 立体規則性触媒を用いて同一重合系で初めに
プロピレンを重合し、次いでエチレン又はエチレ
ンとプロピレンを重合して得たエチレン含量が3
〜30wt%のプロピレン/エチレンブロツク共重
合体パウダーを連続混練部とギヤポンプからなる
造粒機を用いて造粒することを特徴とする耐衝撃
性と剛性のバランスの良好なプロピレン/エチレ
ンブロツク共重合体の製造方法。
1 Propylene is first polymerized in the same polymerization system using a stereoregular catalyst, and then ethylene or ethylene and propylene are polymerized so that the ethylene content is 3
A propylene/ethylene block copolymer with a good balance of impact resistance and rigidity, characterized by granulating ~30wt% propylene/ethylene block copolymer powder using a granulator consisting of a continuous kneading section and a gear pump. Method of manufacturing coalescence.
JP2962984A 1984-02-21 1984-02-21 Manufacture of propylene/ethylene block copolymer Granted JPS60174612A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2962984A JPS60174612A (en) 1984-02-21 1984-02-21 Manufacture of propylene/ethylene block copolymer

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2962984A JPS60174612A (en) 1984-02-21 1984-02-21 Manufacture of propylene/ethylene block copolymer

Publications (2)

Publication Number Publication Date
JPS60174612A JPS60174612A (en) 1985-09-07
JPH0359805B2 true JPH0359805B2 (en) 1991-09-11

Family

ID=12281375

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2962984A Granted JPS60174612A (en) 1984-02-21 1984-02-21 Manufacture of propylene/ethylene block copolymer

Country Status (1)

Country Link
JP (1) JPS60174612A (en)

Also Published As

Publication number Publication date
JPS60174612A (en) 1985-09-07

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