JPH0471933B2 - - Google Patents
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- Publication number
- JPH0471933B2 JPH0471933B2 JP59109574A JP10957484A JPH0471933B2 JP H0471933 B2 JPH0471933 B2 JP H0471933B2 JP 59109574 A JP59109574 A JP 59109574A JP 10957484 A JP10957484 A JP 10957484A JP H0471933 B2 JPH0471933 B2 JP H0471933B2
- Authority
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- Japan
- Prior art keywords
- weight
- critical temperature
- blowing agent
- foaming
- ratio
- 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 - Lifetime
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Description
【発明の詳細な説明】
本発明はポリプロピレン樹脂発泡シートの製造
方法に関し、詳しくは耐熱性が良好であつて、し
かも高品質で高発泡倍率の発泡シートを得ること
のできるポリプロピレン樹脂発泡シートの製造方
法に関する。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a polypropylene resin foam sheet, and more specifically, a method for producing a polypropylene resin foam sheet that has good heat resistance, high quality, and a high expansion ratio. Regarding the method.
従来、樹脂発泡体の製造方法として揮発性発泡
剤を押出機途中で注入し、押出機内で溶融混合
後、ダイより押出して無架橋の高発泡体を製造す
る方法が知られている。 Conventionally, as a method for producing a resin foam, a method has been known in which a volatile foaming agent is injected into an extruder midway through the extruder, the mixture is melted and mixed in the extruder, and then extruded through a die to produce a non-crosslinked highly foamed product.
しかしながら、この発泡成形方法は発泡成形に
適した温度範囲が比較的広く、成形性にすぐれて
いるということより結晶性の比較的低い低密度ポ
リエチレンや非晶性のポリスチレンなどの発泡体
の製造に用いられているにすぎない。また、これ
らの発泡体は耐熱性が十分でなく、近時耐熱性発
泡体の要求により結晶性ポリプロピレン樹脂発泡
体の製造方法が各種提案されている。しかしなが
ら、例えば揮発性発泡剤としてフレオン114（ジク
ロロテトラフロロエタン）を用いる方法では、ポ
リプロピレンの高結晶性のためにその溶解性から
揮発性発泡剤の使用量に限界があり、50倍以上、
特に80倍以上の高発泡倍率の発泡体を得ることが
できない。また、80倍以上の高発泡倍率の発泡体
を得るためにフレオン11（トリクロロモノフロロ
メタン）を用いると、発泡に適した成形範囲が非
常に狭く、高速成形、低ブロー比成形が必要とな
るばかりか表面が波打ち、風合いなどの特性が不
良となるとともに、製品の薄肉化や低速成形など
が不可能となり、多様化する用途に適応すること
ができないという大きな欠点がある。 However, this foam molding method has a relatively wide temperature range suitable for foam molding and has excellent moldability, making it suitable for producing foams such as low-density polyethylene with relatively low crystallinity and amorphous polystyrene. It's just being used. Furthermore, these foams do not have sufficient heat resistance, and in response to the recent demand for heat-resistant foams, various methods for producing crystalline polypropylene resin foams have been proposed. However, in the method of using Freon 114 (dichlorotetrafluoroethane) as a volatile blowing agent, for example, there is a limit to the amount of volatile blowing agent that can be used due to its solubility due to the high crystallinity of polypropylene;
In particular, it is not possible to obtain a foam with a high expansion ratio of 80 times or more. Furthermore, when Freon 11 (trichloromonofluoromethane) is used to obtain a foam with a high expansion ratio of 80 times or more, the molding range suitable for foaming is extremely narrow, requiring high-speed molding and low blow ratio molding. Not only that, but the surface becomes wavy, the texture and other properties become poor, and the product cannot be made thinner or molded at low speed, making it impossible to adapt to diversifying uses.
本発明は上記従来の欠点を解消し、耐熱性が良
好であつて、しかも高品質で高発泡倍率の発泡シ
ートを得ることができるポリプロピレン樹脂発泡
シートの製造方法を提供することを目的とするも
のである。 It is an object of the present invention to provide a method for producing a polypropylene resin foam sheet that eliminates the above-mentioned conventional drawbacks and can produce a foam sheet with good heat resistance, high quality, and a high expansion ratio. It is.
すなわち本発明は、(A)ホモポリプロピレン樹脂
と、(B)低密度ポリエチレン或いは直鎖状低密度ポ
リエチレンとからなり、かつ、前記(B)成分を前記
(A)成分の１〜40重量％の割合で配合してなる樹脂
混合物100重量部に対して、臨界温度が160℃以上
の揮発性発泡剤と、臨界温度が160℃未満の揮発
性発泡剤との混合物であつて、後者の揮発性発泡
剤を全発泡剤量の５〜50重量％の割合で配合した
ものを50〜200重量部の割合で混入した組成物を
溶融混練し、発泡倍率50倍以上に押出成形発泡す
ることを特徴とするポリプロピレン樹脂発泡シー
トの製造方法を提供するものである。 That is, the present invention consists of (A) a homopolypropylene resin and (B) low density polyethylene or linear low density polyethylene, and the (B) component is
A volatile blowing agent with a critical temperature of 160°C or more and a volatile blowing agent with a critical temperature of less than 160°C are added to 100 parts by weight of a resin mixture containing 1 to 40% by weight of component (A). A composition containing 50 to 200 parts by weight of the latter volatile blowing agent in a proportion of 5 to 50% by weight of the total amount of blowing agents is melt-kneaded, and the foaming ratio is The present invention provides a method for producing a polypropylene resin foam sheet, which is characterized by extrusion molding and foaming of 50 times or more.
本発明における樹脂混合物の(A)成分は、ホモポ
リプロピレン樹脂である。このホモポリプロピレ
ン樹脂のメルトインデツクス（MI）は0.2〜20
ｇ／10分、好ましくは0.3〜10ｇ／10分である。 Component (A) of the resin mixture in the present invention is a homopolypropylene resin. The melt index (MI) of this homopolypropylene resin is 0.2 to 20.
g/10 minutes, preferably 0.3 to 10 g/10 minutes.
次に本発明における樹脂混合物の(B)成分として
は、揮発性発泡剤と相溶性の良好なものが用いら
れ、融点が140℃以下の結晶性樹脂の中から、低
密度ポリエチレン（LDPE）或いは直鎖状低密度
ポリエチレン（LLDPE）が選択して用いられる。 Next, as component (B) of the resin mixture in the present invention, a material having good compatibility with a volatile blowing agent is used, and among crystalline resins with a melting point of 140°C or less, low density polyethylene (LDPE) or Linear low density polyethylene (LLDPE) is selected and used.
上記(B)成分の配合量は、前記(A)成分の１〜40重
量％、好ましくは２〜30重量％、より好ましくは
５〜25重量％である。ここで(B)成分の配合量が(A)
成分の40重量％を超えると耐熱性が低下するので
好ましくない。 The blending amount of component (B) is 1 to 40% by weight, preferably 2 to 30% by weight, and more preferably 5 to 25% by weight of component (A). Here, the amount of component (B) is (A)
If it exceeds 40% by weight of the components, heat resistance will decrease, which is not preferable.
なお、本発明においては上記(A)，(B)両成分から
なる樹脂混合物に、必要に応じてタルク、炭酸カ
ルシウム、珪藻土などの気泡核形成剤；着色剤；
酸化防止剤；帯電防止剤などの各種添加剤を適宜
配合してもよい。 In addition, in the present invention, a bubble nucleating agent such as talc, calcium carbonate, diatomaceous earth, etc.; a coloring agent;
Antioxidants; various additives such as antistatic agents may be blended as appropriate.
本発明は、上記成分よりなる樹脂混合物に、臨
界温度が160℃以上の揮発性発泡剤と、臨界温度
が160℃未満の揮発性発泡剤との混合物であつて、
後者の揮発性発泡剤を全発泡剤量の５〜50重量％
の割合で配合したものを混入した組成物を溶融混
練し、発泡倍率50倍以上に押出成形発泡すること
を特徴とするものである。 The present invention provides a mixture of a resin mixture consisting of the above components, a volatile blowing agent having a critical temperature of 160°C or higher, and a volatile blowing agent having a critical temperature of lower than 160°C,
The latter volatile blowing agent is used in an amount of 5 to 50% by weight of the total blowing agent amount.
The composition is melt-kneaded and extruded to a foaming ratio of 50 times or more.
ここで臨界温度が160℃以上の揮発性発泡剤の
具体例を示すと、例えばフレオン11（トリクロロ
モノフロロメタン、臨界温度198℃）、フレオン21
（ジクロロモノフロロメタン、臨界温度178.5℃）、
フレオン113（トリクロロトリフロロエタン、臨界
温度214℃）、ｎ−ペンタン（臨界温度196.6℃）、
ｎ−ヘキサン（臨界温度234.7℃）、イソヘキサン
（臨界温度224.9℃）、ｎ−ヘプタン（臨界温度267
℃）、イソオクタン（臨界温度271.2℃）などが挙
げられる。また、本発明においては、このような
臨界温度が160℃以上の揮発性発泡剤とともに、
臨界温度が160℃未満の揮発性発泡剤を併用する。
このような揮発性発泡剤としては、例えばフレオ
ン114（ジクロロテトラフロロエタン、臨界温度
145.7℃）、フレオン12（ジクロロジフロロメタン、
臨界温度112℃）などが挙げられる。ここで臨界
温度が160℃未満の揮発性発泡剤の使用量は、発
泡剤の種類と樹脂混合物の溶解性に基いて適宜決
定すればよいが、全発泡剤量の５〜50重量％の割
合とする。 Specific examples of volatile blowing agents with a critical temperature of 160°C or higher include Freon 11 (trichloromonofluoromethane, critical temperature 198°C), Freon 21
(dichloromonofluoromethane, critical temperature 178.5℃),
Freon 113 (trichlorotrifluoroethane, critical temperature 214℃), n-pentane (critical temperature 196.6℃),
n-hexane (critical temperature 234.7°C), isohexane (critical temperature 224.9°C), n-heptane (critical temperature 267°C)
℃), isooctane (critical temperature 271.2℃), etc. In addition, in the present invention, along with such a volatile blowing agent having a critical temperature of 160°C or higher,
A volatile blowing agent with a critical temperature of less than 160°C is used.
Such volatile blowing agents include, for example, Freon 114 (dichlorotetrafluoroethane, critical temperature
145.7℃), Freon 12 (dichlorodifluoromethane,
Critical temperature: 112℃). Here, the amount of volatile blowing agent whose critical temperature is less than 160°C may be determined appropriately based on the type of blowing agent and the solubility of the resin mixture, but it should be 5 to 50% by weight of the total amount of blowing agent. shall be.
本発明において押出機等を用い、前記樹脂混合
物を加熱溶融混練し、この溶融樹脂混合物と上記
揮発性発泡剤とを加圧下に混合し、均一な状態と
する。なお、上記揮発性発泡剤は通常溶融混練中
あるいは樹脂混合物の溶融混練が終了した後に混
合する。いずれにしても、樹脂混合物が溶融混練
されて、ある程度均一な状態となつた後で揮発性
発泡剤を混合することが好ましい。 In the present invention, the resin mixture is heated and melted and kneaded using an extruder or the like, and the molten resin mixture and the volatile foaming agent are mixed under pressure to form a uniform state. The volatile blowing agent is usually mixed during melt-kneading or after melt-kneading of the resin mixture is completed. In any case, it is preferable to mix the volatile foaming agent after the resin mixture has been melt-kneaded to a certain degree of uniformity.
ここで上記樹脂混合物と揮発性発泡剤の混合割
合は、目的とする発泡体の発泡倍率等によつて異
なり一義的に定めることは困難であるが、通常樹
脂混合物100重量部に対して、揮発性発泡剤50〜
200重量部、好ましくは70〜150重量部である。 Here, the mixing ratio of the resin mixture and the volatile foaming agent varies depending on the expansion ratio of the desired foam, etc., and is difficult to determine unambiguously, but usually, the mixing ratio of the volatile foaming agent to 100 parts by weight of the resin mixture is Foaming agent 50~
200 parts by weight, preferably 70-150 parts by weight.
このようにして得られる揮発性発泡剤含有溶融
樹脂混合物を、加圧下にダイより押出す。なお、
ダイは通常環状ダイが用いられる。ここでダイ内
の樹脂温度は使用する揮発性発泡剤の臨界温度以
下の温度、すなわち160℃以下の温度であつて、
該臨界温度より20℃以下、特に好ましくは該臨界
温度より30℃以下となる温度にまで冷却される。 The volatile blowing agent-containing molten resin mixture thus obtained is extruded through a die under pressure. In addition,
An annular die is usually used as the die. Here, the resin temperature in the die is a temperature below the critical temperature of the volatile blowing agent used, that is, a temperature below 160°C,
It is cooled to a temperature that is 20° C. or lower than the critical temperature, particularly preferably 30° C. or lower than the critical temperature.
叙上の如くしてポリプロピレン樹脂発泡シート
を得ることができる。 A polypropylene resin foam sheet can be obtained as described above.
本発明においては、上記特定の樹脂混合物およ
び揮発性発泡剤を用いているため、発泡速度が従
来よりも低下している。したがつて、本発明によ
れば成形速度を低くすることができるとともに、
ブロー比を大きくし製品の薄肉化、製品巾の拡大
を図ることができるなど成形可能な範囲を従来よ
りも著しく拡大することができる。さらに押出機
を小型化しても高発泡倍率の製品を得られるなど
経済的にもすぐれるとともに多様化する製品サイ
ズの要求に応えることができる。 In the present invention, since the above-mentioned specific resin mixture and volatile foaming agent are used, the foaming rate is lower than in the past. Therefore, according to the present invention, the molding speed can be lowered, and
By increasing the blow ratio, it is possible to make the product thinner and the width of the product wider, significantly expanding the range of molding possible than before. Furthermore, even if the extruder is made smaller, it is possible to obtain a product with a high expansion ratio, which is economically superior, and it can meet the demands of diversifying product sizes.
しかも本発明によれば50倍以上の高発泡倍率の
製品を得ることができる。 Moreover, according to the present invention, a product with a high expansion ratio of 50 times or more can be obtained.
また本発明により得られるポリプロピレン樹脂
発泡シートは耐熱性が良好であるほか、外観が良
好であつて、波打ちがなく均一であり、しかも気
泡の破裂なく美麗であるなど品質のすぐれたもの
である。 In addition, the polypropylene resin foam sheet obtained by the present invention has good heat resistance, has a good appearance, is uniform without waving, and is beautiful without bursting of bubbles, and is of excellent quality.
さらに本発明によれば、樹脂混合物の組成割合
や揮発性発泡剤の混合量を種々変えることにより
様々な性質の発泡シートを製造することができ
る。 Further, according to the present invention, foamed sheets with various properties can be manufactured by varying the composition ratio of the resin mixture and the mixed amount of the volatile foaming agent.
したがつて、本発明は各種包装材料、断熱材料
等として用いられるポリプロピレン樹脂発泡シー
トの製造に有効に利用することができる。 Therefore, the present invention can be effectively utilized for manufacturing polypropylene resin foam sheets used as various packaging materials, heat insulating materials, and the like.
次に本発明の実施例を示す。 Next, examples of the present invention will be shown.
実施例 １
ホモポリプロピレン（密度0.91ｇ／cm3，MI0.6
ｇ／10分）100重量部、低密度ポリエチレン（密
度0.919ｇ／cm3）15重量部およびタルク0.2重量部
からなる樹脂混合物を、押出機を用いて200℃で
溶融混練した後、トリクロロモノフロロメタン
（臨界温度198℃）とジクロロテトラフロロエタン
（臨界温度145.7℃）の９：１の混合発泡剤を、前
記樹脂混合物100重量部に対して80重量部の割合
で150Kg／cm2で圧入しよく混合しつつ140℃まで冷
却し、30mmφの環状ダイリツプより押出し発泡し
筒状発泡シートを得た。なお引取速度は40m／分
であつた。得られた発泡シートは折り径450mm、
発泡倍率80倍、厚み１mmの波打ちのない美麗な発
泡シートであつた。Example 1 Homopolypropylene (density 0.91 g/cm 3 , MI 0.6
g/10 minutes), 15 parts by weight of low-density polyethylene (density 0.919 g/cm 3 ), and 0.2 parts by weight of talc were melt-kneaded at 200°C using an extruder. A 9:1 mixed blowing agent of methane (critical temperature: 198°C) and dichlorotetrafluoroethane (critical temperature: 145.7°C) was injected at a ratio of 80 parts by weight to 100 parts by weight of the resin mixture at a rate of 150 kg/cm 2 . The mixture was cooled to 140° C. while thoroughly mixed, and extruded and foamed through a 30 mm diameter annular die lip to obtain a cylindrical foam sheet. The take-up speed was 40 m/min. The obtained foam sheet has a folding diameter of 450 mm.
It was a beautiful foam sheet with a foaming ratio of 80 times and a thickness of 1 mm with no waves.
比較例 １
実施例１において、低密度ポリエチレンを用い
なかつたこと以外は実施例１に準じて押出成形を
行ない筒状発泡シートを得た。この場合の最適成
形条件は取引速度70m／分、折り径250mmで、発
泡倍率80倍、肉厚１mmであつた。なお、引取速度
を低くしていつたところ50m／分が限界であり、
この時の折り径は270mm、厚み1.3mmであつた。こ
の結果、広巾、薄肉製品は得られず、またいずれ
の製品も周方向にかなりの波打ちがみられた。Comparative Example 1 A cylindrical foam sheet was obtained by extrusion molding in the same manner as in Example 1 except that low density polyethylene was not used. The optimum molding conditions in this case were a transaction speed of 70 m/min, a fold diameter of 250 mm, a foaming ratio of 80 times, and a wall thickness of 1 mm. In addition, when I lowered the take-up speed, the limit was 50 m/min.
The fold diameter at this time was 270 mm and the thickness was 1.3 mm. As a result, no wide-width, thin-walled products were obtained, and all products had considerable waving in the circumferential direction.
実施例 ２
実施例１において、低密度ポリエチレンの代わ
りに直鎖状エチレン−ブテン−１共重合体（密度
0.922ｇ／cm3，MI4.0ｇ／10分）15重量部を用いた
こと以外は実施例１に準じて押出成形を行ない美
麗な筒状発泡シートを得た。Example 2 In Example 1, linear ethylene-butene-1 copolymer (density
A beautiful cylindrical foam sheet was obtained by extrusion molding in the same manner as in Example 1, except that 15 parts by weight (0.922 g/cm 3 , MI 4.0 g/10 minutes) was used.
比較例 ２
実施例１において、ジクロロテトラフロロエタ
ンを用いなかつたこと以外は、実施例１と同様に
して、筒状発泡シートを得た。得られた発泡シー
トは、発泡倍率30倍という低発泡のものであつ
た。Comparative Example 2 A cylindrical foam sheet was obtained in the same manner as in Example 1 except that dichlorotetrafluoroethane was not used. The obtained foamed sheet had a low foaming ratio of 30 times.
Claims (1)
エチレン或いは直鎖状低密度ポリエチレンとから
なり、かつ、前記(B)成分を前記(A)成分の１〜40重
量％の割合で配合してなる樹脂混合物100重量部
に対して、臨界温度が160℃以上の揮発性発泡剤
と、臨界温度が160℃未満の揮発性発泡剤との混
合物であつて、後者の揮発性発泡剤を全発泡剤量
の５〜50重量％の割合で配合したものを50〜200
重量部の割合で混入した組成物を溶融混練し、発
泡倍率50倍以上に押出成形発泡することを特徴と
するポリプロピレン樹脂発泡シートの製造方法。1 Consisting of (A) homopolypropylene resin and (B) low-density polyethylene or linear low-density polyethylene, and the above-mentioned (B) component is blended in a proportion of 1 to 40% by weight of the above-mentioned (A) component. A mixture of a volatile blowing agent with a critical temperature of 160°C or more and a volatile blowing agent with a critical temperature of less than 160°C with respect to 100 parts by weight of a resin mixture consisting of 50 to 200% of foaming agent mixed at a ratio of 5 to 50% by weight
A method for producing a polypropylene resin foam sheet, which comprises melting and kneading a composition mixed in parts by weight, and extrusion molding and foaming to a foaming ratio of 50 times or more.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP10957484A JPS60255834A (en) | 1984-05-31 | 1984-05-31 | Production of polypropylene resin foam |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP10957484A JPS60255834A (en) | 1984-05-31 | 1984-05-31 | Production of polypropylene resin foam |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS60255834A JPS60255834A (en) | 1985-12-17 |
| JPH0471933B2 true JPH0471933B2 (en) | 1992-11-17 |
Family
ID=14513701
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP10957484A Granted JPS60255834A (en) | 1984-05-31 | 1984-05-31 | Production of polypropylene resin foam |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS60255834A (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH01278539A (en) * | 1988-05-02 | 1989-11-08 | Sekisui Plastics Co Ltd | Polypropylene based resin expanded sheet and production thereof |
| EP3838971B1 (en) | 2019-12-16 | 2023-02-08 | Abu Dhabi Polymers Co. Ltd (Borouge) Llc. | Foamed polypropylene composition suitable for sheets and articles |
Family Cites Families (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS50100167A (en) * | 1973-07-06 | 1975-08-08 | ||
| JPS5429373A (en) * | 1977-08-09 | 1979-03-05 | Kanegafuchi Chem Ind Co Ltd | Thick foamed material of polyporpylene resin and its production |
| JPS54161671A (en) * | 1978-06-09 | 1979-12-21 | Sumitomo Chem Co Ltd | Preparation of polyolefin foam |
| JPS5640167A (en) * | 1979-09-10 | 1981-04-16 | Sumitomo Rubber Ind | Two piece solid golf ball |
| JPS56122841A (en) * | 1980-03-04 | 1981-09-26 | Furukawa Electric Co Ltd:The | Production of heat insulating pipe |
| JPS577174A (en) * | 1980-06-17 | 1982-01-14 | Nec Corp | Atomic beam tube |
| JPS5828289A (en) * | 1981-08-12 | 1983-02-19 | Kyowa Hakko Kogyo Co Ltd | Preparation of alcohol by fermentation |
| JPS5836005A (en) * | 1981-08-28 | 1983-03-02 | Hitachi Ltd | amplifier circuit |
| JPS597025A (en) * | 1982-07-05 | 1984-01-14 | Sumitomo Chem Co Ltd | Manufacture of polypropylene type resin foamed and molded item |
-
1984
- 1984-05-31 JP JP10957484A patent/JPS60255834A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS60255834A (en) | 1985-12-17 |
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