JPH11152361A - Propylene-based resin extruded foam - Google Patents
Propylene-based resin extruded foamInfo
- Publication number
- JPH11152361A JPH11152361A JP25463798A JP25463798A JPH11152361A JP H11152361 A JPH11152361 A JP H11152361A JP 25463798 A JP25463798 A JP 25463798A JP 25463798 A JP25463798 A JP 25463798A JP H11152361 A JPH11152361 A JP H11152361A
- Authority
- JP
- Japan
- Prior art keywords
- foam
- resin
- propylene
- based resin
- foaming
- 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.)
- Pending
Links
Landscapes
- Manufacture Of Porous Articles, And Recovery And Treatment Of Waste Products (AREA)
- Extrusion Moulding Of Plastics Or The Like (AREA)
- Molding Of Porous Articles (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明はプロピレン系樹脂押
出発泡体に関する。The present invention relates to an extruded propylene resin foam.
【０００２】[0002]
【従来の技術】長尺形状の発泡体や、容器等を成形する
ためのシート状発泡体を製造するための方法として、熱
可塑性樹脂を押出機内で発泡剤と溶融混練した後、低圧
下に押出して発泡せしめる押出発泡法が広く採用されて
いる。2. Description of the Related Art As a method for producing a long-sized foam or a sheet-like foam for forming a container or the like, a thermoplastic resin is melt-kneaded with a foaming agent in an extruder, and then subjected to low pressure. An extrusion foaming method of extruding and foaming is widely used.
【０００３】オレフィン系樹脂の押出発泡法において
は、樹脂と発泡剤との溶融混練物を押出機内から低圧下
に押出した際に、溶融混練物中の発泡剤が膨張すること
により発泡が行われるが、樹脂の温度を高くすると粘度
が急激に低下してしまい樹脂が発泡剤を保持できず樹脂
中から逃散して連続気泡の発泡体となり、逆に樹脂の粘
度を高くするために樹脂温度を低くすると樹脂の結晶化
が進行し、その結果、充分且つ均一に発泡しなくなって
発泡体表面が凹凸となってしまうため、押出発泡は充分
に均一な発泡が行われるとともに発泡剤を樹脂中に保持
し得る粘弾性を樹脂が有する温度で行う必要がある。発
泡に適した粘弾性が得られる温度範囲は樹脂の種類によ
って異なっており、一般にこの温度範囲を発泡適性温度
範囲と称している。In the extrusion foaming method of an olefin resin, when a melt-kneaded product of a resin and a foaming agent is extruded under a low pressure from an extruder, foaming is performed by expanding the foaming agent in the melt-kneaded material. However, if the temperature of the resin is increased, the viscosity drops sharply, the resin cannot retain the foaming agent, escapes from the resin and becomes a foam of open cells, and conversely, the resin temperature is increased to increase the viscosity of the resin. When the temperature is lowered, the crystallization of the resin proceeds, and as a result, the foam does not foam sufficiently and uniformly, and the foam surface becomes uneven, so that the extrusion foaming is performed with sufficiently uniform foaming and the foaming agent is mixed into the resin. It is necessary to perform viscoelasticity which can be maintained at a temperature of the resin. The temperature range in which viscoelasticity suitable for foaming is obtained differs depending on the type of resin, and this temperature range is generally referred to as a foaming suitable temperature range.
【０００４】[0004]
【発明が解決しようとする課題】しかしながら、低密度
ポリエチレン等に比べて結晶化度が高いプロピレン系樹
脂は樹脂の粘弾性が僅かな温度変化によって大きく変化
し、発泡適性温度範囲は非常に狭い。このような狭い温
度範囲内に樹脂温度を保持して押出発泡を行うことは非
常に困難なことであり、押出発泡温度が変動して発泡適
性温度範囲から外れた時に発泡した部分は連続気泡構造
となったり表面が凹凸となったりし、全体が良好で均質
な性状の発泡体は得難かった。従来、無架橋のプロピレ
ン系樹脂の場合、比較的良好な発泡体を得ることができ
るのは、密度が0.２ｇ／cm3 を超える低発泡倍率のもの
か、密度が0.０１３ｇ／cm3 未満の高発泡倍率のものと
されている。上記のような問題は、プロピレン系樹脂の
高い結晶性に起因するものと考えられており、密度が0.
２ｇ／cm3 を超える低発泡倍率の押出発泡体が比較的良
好に得られるのは、発泡剤の量に比べて樹脂の割合が多
いため、押出発泡時の樹脂温度をその樹脂の結晶化温度
よりもかなり高い温度に設定することができることに起
因するためと考えられる。また密度が0.０１３ｇ／cm3
未満の高発泡倍率の発泡体を比較的良好に得ることがで
きるのは以下の理由による。However, the propylene-based resin having a higher degree of crystallinity than low-density polyethylene or the like greatly changes the viscoelasticity of the resin due to a slight temperature change, and has a very narrow temperature range for foaming. It is very difficult to carry out extrusion foaming while maintaining the resin temperature within such a narrow temperature range, and when the extrusion foaming temperature fluctuates and deviates from the appropriate foaming temperature range, the foamed portion has an open-cell structure. And the surface became uneven, and it was difficult to obtain a foam having good overall and uniform properties. Conventionally, in the case of a non-crosslinked propylene-based resin, a relatively good foam can be obtained only at a low expansion ratio having a density exceeding 0.2 g / cm 3 or at a density of 0.013 g / cm 3. It has a high expansion ratio of less than. The above-mentioned problems are considered to be caused by the high crystallinity of the propylene-based resin, and the density is 0.
Extruded foams having a low expansion ratio of more than 2 g / cm 3 can be obtained relatively favorably because the ratio of the resin is larger than the amount of the foaming agent. It is considered that the reason is that the temperature can be set to a considerably higher temperature. The density is 0.013 g / cm 3
The reason why a foam having a high expansion ratio of less than 1 can be obtained relatively favorably is as follows.
【０００５】一般に、押出発泡途上にある発泡中のオレ
フィン系樹脂には冷却手段を用いて外部から冷却操作を
施し、それによって、気泡壁を固化させて良好な発泡体
を得ようとしている。しかし、プロピレン系樹脂は低密
度ポリエチレンに比べ結晶化度が高いため、結晶化の際
の発熱量が大きい。この熱が上記冷却ひいては気泡壁の
固化を妨げ、発泡途上にあるプロピレン系樹脂の気泡を
破壊したり変形させたりする。そこで発泡剤を多量に配
合して発泡することで、発泡剤の気化熱（膨張熱）を利
用して発泡途上のプロピレン系樹脂の温度を急激に低下
させ、これによって気泡壁の固化を促進させる。また多
量の発泡剤は押出機中での樹脂の結晶化を遅らせる働き
がある。その結果、比較的良好に発泡体が得られるので
ある。ただし、この場合、発泡剤を多量に配合する必要
性から、得られる発泡体は必然的に密度が0.０１３ｇ／
cm3 未満の高発泡倍率のものとなる。また、この場合に
おいても発泡適性温度範囲はわずか0.６℃程度に過ぎな
い。In general, a foaming olefin-based resin in the process of extrusion foaming is subjected to a cooling operation from the outside by using a cooling means, whereby the cell walls are solidified to obtain a good foam. However, since the propylene-based resin has a higher degree of crystallinity than low-density polyethylene, the calorific value during crystallization is large. This heat hinders the cooling and thus the solidification of the cell walls, and breaks or deforms the cells of the propylene-based resin in the process of foaming. Therefore, by blending a large amount of a foaming agent and foaming, the temperature of the propylene-based resin in the process of foaming is rapidly lowered by utilizing the heat of vaporization (heat of expansion) of the foaming agent, thereby promoting the solidification of the cell wall. . Further, a large amount of the foaming agent has a function of delaying crystallization of the resin in the extruder. As a result, a relatively good foam can be obtained. However, in this case, the foam obtained necessarily has a density of 0.013 g /
It has a high expansion ratio of less than 3 cm 3 . Also in this case, the suitable foaming temperature range is only about 0.6 ° C.
【０００６】本発明は上記高発泡倍率あるいは低発泡倍
率のプロピレン系樹脂押出発泡体しか得られない実情に
鑑みなされたもので、密度が０．１０〜０．２５ｇ／cm
3 、表面気泡数が２６〜４８個／９mm2 で優れた性状を
有するシート状のプロピレン系樹脂押出発泡体を提供す
ることを目的とするものである。The present invention has been made in view of the fact that only an extruded propylene-based resin foam having a high expansion ratio or a low expansion ratio can be obtained, and has a density of 0.10 to 0.25 g / cm.
3. It is an object of the present invention to provide a sheet-like extruded propylene-based resin foam having excellent properties with a surface cell count of 26 to 48 cells / 9 mm 2 .
【０００７】[0007]
【課題を解決するための手段】即ち本発明のプロピレン
系樹脂押出発泡体は、無架橋のプロピレン系樹脂を基材
とするシート状押出発泡体であって、基材樹脂であるプ
ロピレン系樹脂の２３０℃におけるメルトテンションが
７ｇｆ以上、結晶化温度＋１５℃における半結晶化時間
が８００秒以上であり、且つシート状発泡体の密度が
０．１０〜０．２５ｇ／cm3 、表面気泡数が２６〜４８
個／９mm2 であることを特徴とする。That is, the extruded propylene-based resin foam of the present invention is a sheet-like extruded foam having a non-crosslinked propylene-based resin as a base material. The melt tension at 230 ° C. is 7 gf or more, the half-crystallization time at crystallization temperature + 15 ° C. is 800 seconds or more, the density of the sheet-like foam is 0.10 to 0.25 g / cm 3 , and the number of surface bubbles is 26. ~ 48
Pcs / 9 mm 2 .
【０００８】本発明において用いる、２３０℃における
メルトテンションが７ｇｆ以上で，且つ結晶化温度＋１
５℃における半結晶化時間が８００秒以上である無架橋
プロピレン系樹脂は、例えば低分子量のポリプロピレン
を含む全体としてアイソタクチック構造の線状プロピレ
ン系樹脂を低温分解型（分解温度：室温〜１２０℃程
度）の過酸化物と混合して１２０℃以下に加熱し、線状
プロピレン系樹脂に低分子量ポリプロピレンを分岐鎖と
して再結合せしめる等の方法により得ることができ、通
常、線状プロピレン系樹脂の主として端部に長鎖分岐を
有する枝別れ状構造を有すると考えられる。上記線状プ
ロピレン系樹脂としては、プロピレンホモポリマーや、
プロピレンと他のオレフィンとの共重合体等が挙げられ
る。プロピレンと共重合可能な他のオレフィンとして
は、エチレン、１−ブテン、イソブチレン、１−ペンテ
ン、３−メチル−１−ブテン、１−ヘキセン、3,4-ジメ
チル−１−ブテン、１−ヘプテン、３−メチル−１−ヘ
キセン等が挙げられる。また上記低温分解型の過酸化物
としては、ジ（ｓ−ブチル）ペルオキシジカーボネー
ト、ビス（２−エトキシ）ペルオキシジカーボネート、
ジシクロヘキシルペルオキシジカーボネート、ジ−ｎ−
プロピルペルオキシジカーボネート、ジ−ｎ−ブチルペ
ルオキシジカーボネート、ジイソプロピルペルオキシジ
カーボネート、ｔ−ブチルペルオキシネオデカノアー
ト、ｔ−アミルペルオキシネオデカノアートおよびｔ−
ブチルペルオキシピバラート等が例示される。In the present invention, the melt tension at 230 ° C. is 7 gf or more, and the crystallization temperature is +1.
The non-crosslinked propylene-based resin having a half-crystallization time of 800 seconds or longer at 5 ° C. is a low-temperature decomposition type (decomposition temperature: room temperature to 120 ° C.) C.) and heated to 120 ° C. or lower, and then recombined with a low-molecular-weight polypropylene as a branched chain in the linear propylene-based resin. Is considered to have a branched structure having a long chain branch mainly at the end. As the linear propylene-based resin, propylene homopolymer,
Copolymers of propylene with other olefins and the like can be mentioned. Other olefins copolymerizable with propylene include ethylene, 1-butene, isobutylene, 1-pentene, 3-methyl-1-butene, 1-hexene, 3,4-dimethyl-1-butene, 1-heptene, 3-methyl-1-hexene and the like. Further, as the low-temperature decomposition type peroxide, di (s-butyl) peroxydicarbonate, bis (2-ethoxy) peroxydicarbonate,
Dicyclohexyl peroxydicarbonate, di-n-
Propyl peroxy dicarbonate, di-n-butyl peroxy dicarbonate, diisopropyl peroxy dicarbonate, t-butyl peroxy neodecanoate, t-amyl peroxy neodecanoate and t-
Butyl peroxypivalate is exemplified.
【０００９】本発明において用いる無架橋プロピレン系
樹脂は、上記アイソタクチック構造の線状プロピレン系
樹脂を、攪拌機を備えた反応器中で攪拌しながらアルゴ
ン等の不活性ガスで反応容器内を置換し、次いで上記過
酸化物を樹脂１kg当たり通常５〜５０ミリモル添加し、
攪拌を続けながら１２０℃程度まで、好ましくは７０〜
１０５℃程度に加熱して反応させ（通常３０〜１２０分
間）、しかる後、反応を停止させて得られる。反応停止
に当たっては、メチルメルカプタンのような反応停止剤
を反応容器に導入したり、あるいは反応生成物を１３０
〜１５０℃程度に２０〜４０分間加熱する方法等が採用
される。The non-crosslinked propylene resin used in the present invention is obtained by replacing the above isotactic linear propylene resin with an inert gas such as argon while stirring in a reactor equipped with a stirrer. Then, the above peroxide is usually added in an amount of 5 to 50 mmol per kg of the resin,
While stirring, up to about 120 ° C., preferably 70 to
It is obtained by heating to about 105 ° C. to cause a reaction (usually for 30 to 120 minutes), and then terminating the reaction. When terminating the reaction, a reaction terminator such as methyl mercaptan is introduced into the reaction vessel, or the reaction product is added to
For example, a method of heating to about 150 ° C. for about 20 to 40 minutes is employed.
【００１０】本発明においては上記の樹脂を単独で用い
るのみならず、上記の樹脂に他の樹脂を混合して用いる
こともできる。混合して用いる樹脂としては、例えば上
記以外のプロピレン系樹脂、或いは高密度ポリエチレ
ン、低密度ポリエチレン、直鎖状低密度ポリエチレン、
直鎖状超低密度ポリエチレン、エチレン−ブテン共重合
体、エチレン−無水マレイン酸共重合体等のエチレン系
樹脂、ブテン系樹脂、ポリ塩化ビニル、塩化ビニル−酢
酸ビニル共重合体等の塩化ビニル系樹脂、スチレン系樹
脂等が挙げられる。In the present invention, not only the above resin can be used alone, but also other resins can be mixed with the above resin. As the resin used in combination, for example, a propylene-based resin other than the above, or high-density polyethylene, low-density polyethylene, linear low-density polyethylene,
Ethylene resins such as linear ultra-low density polyethylene, ethylene-butene copolymer, ethylene-maleic anhydride copolymer, butene resins, polyvinyl chloride, vinyl chloride such as vinyl chloride-vinyl acetate copolymer Resins, styrene resins and the like.
【００１１】本発明において樹脂のメルトテンションは
メルトテンションテスターによって測定することができ
る。また本発明において半結晶化時間の測定には結晶化
速度測定器を用いることができる。半結晶化速度を測定
するには、まずフィルム状の試料を保持した支持体を、
結晶化速度測定器のエアバス内に入れて試料を完全に溶
融させ、次いで溶融試料を支持体ごと試料の結晶化温度
＋１５℃の温度に保持されたオイルバス中に、光源と光
センサーの光路を遮るように浸漬し、溶けた試料が再度
固化するまでの間、光センサーにおいて常に一定の光量
が検出されるように光源の電圧を調整し、図１に示す如
き電圧〜時間曲線を得る。この曲線における電圧が一定
値となった時の電圧をＶ0 とした時、電圧が１／２Ｖ0
となるまでの時間を半結晶化時間とした。In the present invention, the melt tension of the resin can be measured by a melt tension tester. In the present invention, a crystallization rate measuring device can be used for measuring the half-crystallization time. To measure the semi-crystallization rate, first, the support holding the film-like sample is
The sample is completely melted by placing it in an air bath of a crystallization rate measuring instrument. Then, the optical path of the light source and the optical sensor is placed in an oil bath in which the molten sample and the support together with the sample are kept at a temperature of 15 ° C. The voltage of the light source is adjusted so that a constant amount of light is always detected by the optical sensor until the melted sample solidifies again, so as to obtain a voltage-time curve as shown in FIG. Assuming that the voltage when the voltage in this curve becomes a constant value is V 0 , the voltage is Ｖ V 0
The time required to reach was defined as the half-crystallization time.
【００１２】本発明のシート状押出発泡体は、密度０．
１０〜０．２５ｇ／cm3 で、表面気泡数が２６〜４８個
／９mm2 のものである。The extruded sheet foam of the present invention has a density of 0.3.
It is 10 to 0.25 g / cm 3 and the number of surface bubbles is 26 to 48/9 mm 2 .
【００１３】本発明の発泡体において、シート状発泡体
を構成する基材樹脂中に、総重量の１５〜５０重量％の
無機充填剤を含有することが好ましい。無機充填剤とし
ては、例えばタルク、シリカ、炭酸カルシウム、クレ
ー、ゼオライト、アルミナ、硫酸バリウム等が挙げられ
る。これらの平均粒径は１〜７０μｍであることが好ま
しい。このような無機物を多量に含有するシート状の発
泡体は耐熱性が向上するとともに焼却処理の際の燃焼カ
ロリーを低下させることが可能となる。In the foam of the present invention, the base resin constituting the sheet-like foam preferably contains 15 to 50% by weight of the total weight of the inorganic filler. Examples of the inorganic filler include talc, silica, calcium carbonate, clay, zeolite, alumina, barium sulfate and the like. It is preferable that these particles have an average particle size of 1 to 70 μm. Such a sheet-like foam containing a large amount of an inorganic substance can improve heat resistance and reduce the calorie burned during incineration.
【００１４】本発明は上記シート状発泡体は加熱成形し
て成形体を得ることができる。シート状発泡体の成形方
法としては、真空成形、圧空成形やこれらの応用とし
て、フリードローイング成形、プラグ・アンド・リッジ
成形、リッジ成形、マッチド・モールド成形、ストレー
ト成形、ドレープ成形、リバースドロー成形、エアスリ
ップ成形、プラグアシスト成形、プラグアシストリバー
スドロー成形等やこれらを組み合わせた方法等を適用す
ることができる。In the present invention, a molded article can be obtained by subjecting the above-mentioned sheet-shaped foam to heat molding. Examples of the method for forming the sheet-like foam include vacuum forming, pressure forming, and applications of these, such as free drawing forming, plug and ridge forming, ridge forming, matched mold forming, straight forming, drape forming, reverse draw forming, and the like. Air slip molding, plug assist molding, plug assist reverse draw molding and the like, a method combining these, and the like can be applied.
【００１５】本発明の押出発泡体を得る方法として、押
出機内で樹脂と発泡剤とを溶融混練した後、この溶融混
練物を押出機先端に取り付けたダイスを通して低圧下に
押出して発泡する方法が採用される。シート状の発泡体
を得るためには、環状のリップを有するサーキュラーダ
イスを用い、このダイスのリップより押出発泡してチュ
ーブ状の発泡体を得、次いでこのチューブを切り開いて
シート状とする方法が通常採用される。As a method for obtaining the extruded foam of the present invention, there is a method in which a resin and a foaming agent are melt-kneaded in an extruder, and the melt-kneaded product is extruded under a low pressure through a die attached to the tip of the extruder to foam. Adopted. In order to obtain a sheet-like foam, there is a method of using a circular die having an annular lip, extruding and foaming from the lip of the die to obtain a tubular foam, and then cutting and opening the tube to form a sheet. Usually adopted.
【００１６】発泡剤としては、無機発泡剤、揮発性発泡
剤、分解型発泡剤等を用いることができる。無機発泡剤
としては、二酸化炭素、空気、窒素等を用いることがで
きる。揮発性発泡剤としてはプロパン、ｎ−ブタン、ｉ
−ブタン、ペンタン、ヘキサン等の脂肪族炭化水素、シ
クロブタン、シクロペンタン等の環式脂肪族炭化水素、
トリクロロフロロメタン、ジクロロジフロロメタン、ジ
クロロテトラフロロエタン、メチルクロライド、エチル
クロライド、メチレンクロライド等のハロゲン化炭化水
素等を用いることができる。また分解型発泡剤として
は、アゾジカルボンアミド、ジニトロソペンタメチレン
テトラミン、アゾビスイソブチロニトリル、重炭酸ナト
リウム等を用いることができる。これらの発泡剤は適宜
混合して用いることもできる。発泡剤の使用量は、発泡
剤の種類、所望する発泡倍率等によっても異なるが、例
えば密度0.２〜0.０１３ｇ／cm3 程度の発泡体を得るた
めの発泡剤の使用量の目安は、樹脂１００重量部当たり
揮発性発泡剤0.５〜２５重量部（ブタン換算）程度であ
る。また密度0.０９ｇ／cm3 を超える発泡体を得るため
の発泡剤の使用量の目安は、樹脂１００重量部当たり、
無機発泡剤の場合0.１〜１０重量部程度、分解型発泡剤
の場合0.１〜５重量部程度である。As the foaming agent, an inorganic foaming agent, a volatile foaming agent, a decomposition-type foaming agent and the like can be used. As the inorganic foaming agent, carbon dioxide, air, nitrogen and the like can be used. The volatile blowing agents include propane, n-butane, i
-Butane, pentane, aliphatic hydrocarbons such as hexane, cyclobutane, cycloaliphatic hydrocarbons such as cyclopentane,
Halogenated hydrocarbons such as trichlorofluoromethane, dichlorodifluoromethane, dichlorotetrafluoroethane, methyl chloride, ethyl chloride, and methylene chloride can be used. Further, as the decomposition type foaming agent, azodicarbonamide, dinitrosopentamethylenetetramine, azobisisobutyronitrile, sodium bicarbonate and the like can be used. These foaming agents can be used by being appropriately mixed. The amount of the foaming agent used depends on the type of the foaming agent, the desired expansion ratio, and the like. For example, the standard of the amount of the foaming agent used to obtain a foam having a density of about 0.2 to 0.013 g / cm 3 is as follows. And about 0.5 to 25 parts by weight (in terms of butane) of a volatile foaming agent per 100 parts by weight of the resin. The amount of the foaming agent used to obtain a foam having a density of more than 0.09 g / cm 3 is estimated based on 100 parts by weight of the resin.
In the case of an inorganic foaming agent, it is about 0.1 to 10 parts by weight, and in the case of a decomposition type foaming agent, it is about 0.1 to 5 parts by weight.
【００１７】本発明において樹脂と発泡剤との溶融混練
物中に、更に気泡調整剤を添加しても良い。気泡調整剤
としてはタルク、シリカ等の無機粉末や多価カルボン酸
の酸性塩、多価カルボン酸と炭酸ナトリウム或いは重炭
酸ナトリウムとの反応混合物等が挙げられる。気泡調整
剤は樹脂１００重量部当たり１３重量部程度以下添加す
ることが好ましい（ただし、前記無機充填剤を樹脂に多
量に含有させる場合は除く。）。また必要に応じて、更
に熱安定剤、紫外線吸収剤、酸化防止剤、着色剤等の添
加剤を添加することもできる。In the present invention, a foam control agent may be further added to the melt-kneaded product of the resin and the foaming agent. Examples of the cell regulator include inorganic powders such as talc and silica, acidic salts of polycarboxylic acids, and reaction mixtures of polycarboxylic acids with sodium carbonate or sodium bicarbonate. It is preferable to add about 13 parts by weight or less of the foam control agent per 100 parts by weight of the resin (except when the inorganic filler is contained in a large amount in the resin). Further, if necessary, additives such as a heat stabilizer, an ultraviolet absorber, an antioxidant, and a colorant can be added.
【００１８】[0018]
【実施例】以下、実施例を挙げて本発明を更に詳細に説
明する。尚、実施例、比較例において使用した樹脂の物
性を表１に示した。また実施例、比較例において発泡
剤、気泡調整剤の添加量は、これらと樹脂との総和を１
００重量部とした時の重量割合である。使用した樹脂の
メルトテンションの測定には（株）東洋精機製作所製の
メルトテンションテスターII型を用い、半結晶化時間の
測定にはコタキ商事（株）製の結晶化速度測定器ＭＫ−
８０１型を使用した。EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples. Table 1 shows the physical properties of the resins used in Examples and Comparative Examples. In Examples and Comparative Examples, the amounts of the foaming agent and the foam control agent were such that the sum of these and the resin was 1
It is a weight ratio when it is set to 00 parts by weight. The melt tension of the resin used was measured using a melt tension tester type II manufactured by Toyo Seiki Seisaku-Sho, Ltd. The crystallization speed meter MK- manufactured by Kotaki Shoji Co., Ltd. was used to measure the half-crystallization time.
Type 801 was used.
【００１９】尚、メルトテンションの測定は次の通り行
うものとする。メルトインデクサーのノズル（口径2.０
９５mm、長さ８mm）より２３０℃に加熱した溶融プロピ
レン系樹脂を上方より荷重をかけて１０mm／分の一定速
度で紐状に押出し、該押出物を張力検出プーリーを通過
させて送りロールに導いて巻き取る一方で巻取り速度を
徐々に増加させていって紐状物を切断させ、この切断直
前の張力を読み取り、これをメルトテンション（ｇｆ）
とする。但し、巻き取り速度７8.５ｍ／分において紐状
物が切断しない場合には、この時の張力を読み取り、こ
れをメルトテンションとする。The measurement of the melt tension is performed as follows. Melt indexer nozzle (caliber 2.0
(95 mm, length: 8 mm) A molten propylene-based resin heated to 230 ° C from above is extruded in a string shape at a constant speed of 10 mm / min under a load from above, and the extruded product is guided to a feed roll through a tension detection pulley. While winding, the winding speed is gradually increased to cut the string, the tension immediately before the cutting is read, and the melt tension (gf) is read.
And However, if the string-like material is not cut at a winding speed of 78.5 m / min, the tension at this time is read and this is defined as the melt tension.
【００２０】[0020]
【表１】 [Table 1]
【００２１】実施例１ 樹脂Ａの９３重量部当たりに対し、イソブタン２重量
部、タルク５重量部を、上記実施例と同様の押出機内で
溶融混練した後、径７５mmφ、間隙0.５mmのサーキュラ
ーダイスより押出してチューブ状の発泡体を得た。この
チューブ状の発泡体の内側及び外側に空気吹きつけ用の
リングを設置してチューブの外面側及び内面側に空気を
吹付け、更にチューブ状発泡体の内面側が冷却用マンド
レル（マンドレル径はリップ径の2.０倍）に接するよう
にして引取り、ブロー比2.０倍のチューブ得、このチュ
ーブを切り開いてシートを得た。押出発泡温度は１６２
℃、１６５℃、１６８℃の３種類で行い、各押出発泡温
度で得られたシートの状態を表２に示した。尚、押出発
泡温度は、樹脂中の異物等を取り除くためのメッシュ状
スクリーンを取り付けたブレーカープレートを押出機と
サーキュラーダイスとの間に設け、このブレーカープレ
ート部で測定した。Example 1 After 2 parts by weight of isobutane and 5 parts by weight of talc were melt-kneaded in the same extruder as in the above-mentioned example, 93 parts by weight of resin A were mixed, and then a circular cylinder having a diameter of 75 mm and a gap of 0.5 mm was used. It was extruded from a die to obtain a tubular foam. Rings for air blowing are installed inside and outside of this tubular foam to blow air to the outer and inner surfaces of the tube, and the inner surface of the tubular foam is cooled with a cooling mandrel (mandrel diameter is lip (2.0 times the diameter) to obtain a tube having a blow ratio of 2.0 times. The tube was cut open to obtain a sheet. Extrusion foaming temperature is 162
C., 165.degree. C., and 168.degree. C., and the state of the sheet obtained at each extrusion foaming temperature is shown in Table 2. The extrusion foaming temperature was measured at a breaker plate portion provided with a breaker plate provided with a mesh screen for removing foreign substances and the like in the resin, between the extruder and the circular die.
【００２２】発泡シートの状態は、 ○・・・表面凹凸が小さく、連続気泡の部分が実質的に
なく、全体が略均質な性状を有する。 ×・・・表面に凹凸やコルゲートが激しかったり、連続
気泡構造の部分が多かったりし、全体が均質な性状を有
していない。 として評価した。The state of the foamed sheet is as follows: ・ ・ ・: The surface irregularities are small, there are substantially no open cells, and the whole has substantially uniform properties. ×: The surface is very uneven or corrugated, or has many portions with an open cell structure, and the whole does not have uniform properties. Was evaluated.
【００２３】[0023]
【表２】 [Table 2]
【００２４】比較例１ 樹脂Ｅの９6.５重量部当たり、イソブタン２重量部、タ
ルク1.５重量部を、実施例５で用いたと同様の押出機内
で溶融混練した後、同様のサーキュラーダイスより押出
して発泡した。押出発泡温度が１８１℃を超えると発泡
剤ガスが樹脂中から逃散して発泡体が得られず、押出発
泡温度が１８１℃では独立気泡構造の発泡体は得られる
が、押出発泡して得たチューブ状の発泡体をマンドレル
に通すとチューブが裂けて良好なシートを得ることがで
きなかった。押出発泡温度を１７９℃とするとチューブ
状の発泡体をマンドレルに通してもチューブが裂けるこ
とはなかったが、チューブのマンドレル上での滑りが悪
く引取りが困難となった。また、押出発泡温度を１７８
℃まで下げると押出機の圧力が高くなり押出発泡不能と
なった。発泡適性温度範囲は１８０±１℃程度と非常に
狭かった。押出発泡温度が１７９℃の時に得られた発泡
シートは厚み0.９mm、発泡体密度0.２７ｇ／cm3 であっ
たが、表面には凹凸が激しく、部分的に裂けたりしてお
り全体が均質な発泡シートではなかった。Comparative Example 1 2 parts by weight of isobutane and 1.5 parts by weight of talc per 96.5 parts by weight of resin E were melt-kneaded in the same extruder used in Example 5, and then the same circular die was used. Extruded and foamed. When the extrusion foaming temperature exceeds 181 ° C., the foaming agent gas escapes from the resin and a foam cannot be obtained. When the extrusion foaming temperature is 181 ° C., a foam having a closed cell structure can be obtained. When a tubular foam was passed through a mandrel, the tube was torn and a good sheet could not be obtained. When the extrusion foaming temperature was 179 ° C., the tube did not tear even when the tube-shaped foam was passed through the mandrel, but the tube slipped on the mandrel and became difficult to take off. Further, the extrusion foaming temperature is set to 178.
When the temperature was lowered to ° C., the pressure of the extruder increased, and extrusion foaming was impossible. The suitable foaming temperature range was as narrow as about 180 ± 1 ° C. The foam sheet obtained when the extrusion foaming temperature was 179 ° C. had a thickness of 0.9 mm and a foam density of 0.27 g / cm 3 , but the surface was severely uneven, and the surface was partially torn and the whole was It was not a homogeneous foam sheet.
【００２５】実施例２〜４ 樹脂Ｂ、ブタン及びクエン酸モノナトリウム塩とを表３
に示す割合でタンデム押出機（第１押出機：スクリュー
径６５mm、Ｌ／Ｄ＝３４、第２押出機：スクリュー径９
０mm、Ｌ／Ｄ＝３２）に配合し、溶融混練した後、押出
機先端に取り付けた６５mmφ、間隙0.５mmのサーキュラ
ーダイスよりチューブ状に押出発泡する一方で、該発泡
体の内外表面に空気を吹き付けると共に、更に内表面が
冷却用マンドレル（マンドレル径２００mm）に接するよ
うにして引取り、その後、このチューブ状発泡体を押出
方向の一端より切り開いてシートとした。この時の押出
条件及び得られた発泡シートの性状を併せて表３に示
す。Examples 2-4 Resin B, butane and monosodium citrate were used in Table 3
Tandem extruder (first extruder: screw diameter 65 mm, L / D = 34, second extruder: screw diameter 9)
0 mm, L / D = 32), melt-kneaded, and extruded into a tube from a circular die with a gap of 0.5 mm and a diameter of 65 mm attached to the tip of the extruder, while air is applied to the inner and outer surfaces of the foam. , And the inner surface was further taken off so as to be in contact with a cooling mandrel (mandrel diameter 200 mm). Thereafter, the tubular foam was cut out from one end in the extrusion direction to form a sheet. The extrusion conditions at this time and the properties of the obtained foamed sheet are also shown in Table 3.
【００２６】[0026]
【表３】 [Table 3]
【００２７】次に上記実施例２〜４で得られた各シート
を、１６５℃の雰囲気温度の加熱炉で、それぞれ１４秒
間、１１秒間及び１０秒間加熱し、プラグアシスト真空
成形を行ったところ、ナキや破断のない均質度の高い容
器が得られた。この容器は図２、図３に示すように仕切
り１０の両側に収納部１１、１２を有する皿状の容器で
あり、図２、図３中、ａ〜ｈの各寸法は、ａ：１7.５c
m、ｂ：１1.２cm、ｃ：6.３cm、ｄ：１１cm、ｅ：９c
m、ｆ：４cm、ｇ：3.５cm、ｈ：2.５cmである。Next, each of the sheets obtained in Examples 2 to 4 was heated in a heating furnace at an atmosphere temperature of 165 ° C. for 14 seconds, 11 seconds and 10 seconds, respectively, to perform plug-assist vacuum forming. A container with high homogeneity without pear or breakage was obtained. This container is a dish-shaped container having storage portions 11 and 12 on both sides of a partition 10 as shown in FIGS. 2 and 3, and the dimensions a to h in FIGS. 2 and 3 are a: 17. 5c
m, b: 11.2 cm, c: 6.3 cm, d: 11 cm, e: 9c
m, f: 4 cm, g: 3.5 cm, h: 2.5 cm.
【００２８】比較例２ 樹脂Ｅの９6.５重量部当たり、ブタン２重量部、タルク
1.５重量部を、実施例９で用いたと同様の押出機内で溶
融混練した後、同様のサーキュラーダイスより押出して
発泡した。押出発泡温度が１７３℃を超えると発泡剤ガ
スが樹脂中から逃散して発泡体が得られなかった。押出
発泡温度が１７２℃では独立気泡構造の発泡体は得られ
るが、押出発泡して得たチューブ状の発泡体をマンドレ
ルに通すとチューブが裂け、更にチューブのマンドレル
上での滑りが悪く引取りが困難であった。また、押出発
泡温度を１７０℃まで下げると押出機の圧力が高くなり
押出発泡不能となった。押出発泡温度が１７２℃の時に
得られた発泡シートは厚み0.６mm、密度0.５６ｇ／cm3
であったが、表面には凹凸が激しく、部分的に裂けたり
しており全体が均質な発泡シートではなかった。Comparative Example 2 2 parts by weight of butane per 96.5 parts by weight of resin E, talc
After melt-kneading 1.5 parts by weight in the same extruder as used in Example 9, the mixture was extruded from the same circular die and foamed. When the extrusion foaming temperature exceeded 173 ° C., the foaming agent gas escaped from the resin, and a foam was not obtained. When the extrusion foaming temperature is 172 ° C., a foam having a closed cell structure can be obtained. However, when the tubular foam obtained by extrusion foaming is passed through a mandrel, the tube is torn, and the tube slips on the mandrel. Was difficult. Further, when the extrusion foaming temperature was lowered to 170 ° C., the pressure of the extruder was increased, and extrusion foaming was impossible. The foamed sheet obtained when the extrusion foaming temperature was 172 ° C had a thickness of 0.6 mm and a density of 0.56 g / cm 3.
However, the surface was severely uneven and was partially torn, and the whole was not a uniform foamed sheet.
【００２９】[0029]
【発明の効果】以上説明したように本発明のプロピレン
系樹脂押出発泡体の基材樹脂は、２３０℃におけるメル
トテンションが７ｇｆ以上、結晶化温度＋１５℃におけ
る半結晶化時間が８００秒以上の無架橋のプロピレン系
樹脂であり、この樹脂は従来の無架橋プロピレン系樹脂
に比べて発泡適性温度範囲が広いため、押出発泡温度の
コントロールが容易であり、無架橋プロピレン系樹脂を
基材樹脂に用いて全体が均質で優れた性状のプロピレン
系樹脂押出発泡体を得ることができる。本発明のシート
状の押出発泡体は、表面凹凸が小さく、連続気泡の部分
が実質的になく、全体が略均質な性状を有する等の優れ
たものであり、容器等を成形する場合でも、得られた成
形体は収縮等のない性状良好なものである。As described above, the base resin of the extruded propylene resin foam of the present invention has a melt tension at 230 ° C. of 7 gf or more and a half-crystallization time of 800 seconds or more at a crystallization temperature of + 15 ° C. It is a cross-linked propylene resin, and since this resin has a wider range of suitable foaming temperature than conventional non-crosslinked propylene resin, it is easy to control the extrusion foaming temperature and uses non-crosslinked propylene resin as the base resin. As a result, a propylene-based resin extruded foam having uniform properties and excellent properties can be obtained. The sheet-like extruded foam of the present invention has excellent surface irregularities, having a small surface irregularity, substantially no open-cell portions, and having substantially uniform properties as a whole, even when molding a container or the like. The obtained molded article has good properties without shrinkage or the like.
【図１】結晶化速度測定によって得られた電圧〜時間曲
線である。FIG. 1 is a voltage-time curve obtained by crystallization rate measurement.
【図２】実施例２〜４で得られたシートを成形して得た
皿状容器の平面図である。FIG. 2 is a plan view of a dish-shaped container obtained by molding the sheets obtained in Examples 2 to 4.
【図３】実施例２〜４で得られたシートを成形して得た
皿状容器の側面図である。FIG. 3 is a side view of a dish-shaped container obtained by molding the sheets obtained in Examples 2 to 4.
───────────────────────────────────────────────────── フロントページの続き (72)発明者 青木 健 栃木県日光市野口690−６ ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Takeshi Aoki 690-6 Noguchi, Nikko-shi, Tochigi
Claims (1)
シート状押出発泡体であって、基材樹脂であるプロピレ
ン系樹脂の２３０℃におけるメルトテンションが７ｇｆ
以上、結晶化温度＋１５℃における半結晶化時間が８０
０秒以上であり、且つシート状発泡体の密度が０．１０
〜０．２５ｇ／cm3 、表面気泡数が２６〜４８個／９mm
2 であることを特徴とするプロピレン系樹脂押出発泡
体。1. A sheet-like extruded foam comprising a non-crosslinked propylene resin as a base material, wherein the propylene resin as a base resin has a melt tension of 7 gf at 230 ° C.
As described above, the half-crystallization time at the crystallization temperature + 15 ° C. is 80.
0 seconds or more, and the density of the sheet-like foam is 0.10
~0.25g / cm 3, the surface of the number of bubbles is 26 to 48 pieces / 9mm
2. An extruded propylene resin foam, which is 2.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP25463798A JPH11152361A (en) | 1991-09-11 | 1998-08-25 | Propylene-based resin extruded foam |
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3259644A JP2859983B2 (en) | 1991-03-26 | 1991-09-11 | Extruded propylene resin foam, molded article and method for producing the same |
| JP25463798A JPH11152361A (en) | 1991-09-11 | 1998-08-25 | Propylene-based resin extruded foam |
Related Parent Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP3259644A Division JP2859983B2 (en) | 1991-03-26 | 1991-09-11 | Extruded propylene resin foam, molded article and method for producing the same |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH11152361A true JPH11152361A (en) | 1999-06-08 |
Family
ID=17267794
Family Applications (3)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP25463798A Pending JPH11152361A (en) | 1991-09-11 | 1998-08-25 | Propylene-based resin extruded foam |
| JP10254635A Pending JPH11152359A (en) | 1991-09-11 | 1998-08-25 | Propylene-based resin extruded foam and preparation thereof |
| JP10254636A Pending JPH11152360A (en) | 1991-09-11 | 1998-08-25 | Propylene-based resin extruded foam and preparation thereof |
Family Applications After (2)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP10254635A Pending JPH11152359A (en) | 1991-09-11 | 1998-08-25 | Propylene-based resin extruded foam and preparation thereof |
| JP10254636A Pending JPH11152360A (en) | 1991-09-11 | 1998-08-25 | Propylene-based resin extruded foam and preparation thereof |
Country Status (1)
| Country | Link |
|---|---|
| JP (3) | JPH11152361A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002046164A (en) * | 2000-08-04 | 2002-02-12 | Jsp Corp | Polypropylene resin extruded foam, and its production method |
| WO2009001959A1 (en) * | 2007-06-28 | 2008-12-31 | Asahi Fiber Glass Company, Limited | Method for production of uncrosslinked polyolefin resin foam |
| JP2020084035A (en) * | 2018-11-26 | 2020-06-04 | 日立化成株式会社 | Foam molding and method for producing foam molding |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4421654B2 (en) * | 2008-01-16 | 2010-02-24 | 日東電工株式会社 | Manufacturing method of heated foam sheet |
-
1998
- 1998-08-25 JP JP25463798A patent/JPH11152361A/en active Pending
- 1998-08-25 JP JP10254635A patent/JPH11152359A/en active Pending
- 1998-08-25 JP JP10254636A patent/JPH11152360A/en active Pending
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002046164A (en) * | 2000-08-04 | 2002-02-12 | Jsp Corp | Polypropylene resin extruded foam, and its production method |
| WO2009001959A1 (en) * | 2007-06-28 | 2008-12-31 | Asahi Fiber Glass Company, Limited | Method for production of uncrosslinked polyolefin resin foam |
| JP2020084035A (en) * | 2018-11-26 | 2020-06-04 | 日立化成株式会社 | Foam molding and method for producing foam molding |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH11152360A (en) | 1999-06-08 |
| JPH11152359A (en) | 1999-06-08 |
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