JPH04356540A - Production of thermoplastic resin foam - Google Patents
Production of thermoplastic resin foamInfo
- Publication number
- JPH04356540A JPH04356540A JP23310891A JP23310891A JPH04356540A JP H04356540 A JPH04356540 A JP H04356540A JP 23310891 A JP23310891 A JP 23310891A JP 23310891 A JP23310891 A JP 23310891A JP H04356540 A JPH04356540 A JP H04356540A
- Authority
- JP
- Japan
- Prior art keywords
- thermoplastic resin
- producing
- temperature
- resin foam
- resin
- 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.)
- Granted
Links
- 229920005992 thermoplastic resin Polymers 0.000 title claims abstract description 55
- 239000006260 foam Substances 0.000 title claims abstract description 45
- 238000004519 manufacturing process Methods 0.000 title claims description 15
- 238000000034 method Methods 0.000 claims abstract description 22
- 229920005989 resin Polymers 0.000 claims abstract description 22
- 239000011347 resin Substances 0.000 claims abstract description 22
- 238000010438 heat treatment Methods 0.000 claims abstract description 13
- 238000001816 cooling Methods 0.000 claims abstract description 6
- 238000002425 crystallisation Methods 0.000 claims description 25
- 239000007789 gas Substances 0.000 claims description 25
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 claims description 16
- 238000005187 foaming Methods 0.000 claims description 16
- -1 polyethylene terephthalate Polymers 0.000 claims description 12
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 claims description 10
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims description 8
- 239000001569 carbon dioxide Substances 0.000 claims description 8
- 229910002092 carbon dioxide Inorganic materials 0.000 claims description 8
- 238000002844 melting Methods 0.000 claims description 7
- 230000008018 melting Effects 0.000 claims description 7
- 229920006395 saturated elastomer Polymers 0.000 claims description 7
- 229920001225 polyester resin Polymers 0.000 claims description 6
- 239000004645 polyester resin Substances 0.000 claims description 6
- 229910052786 argon Inorganic materials 0.000 claims description 5
- 229920002292 Nylon 6 Polymers 0.000 claims description 3
- 229920002302 Nylon 6,6 Polymers 0.000 claims description 3
- 229920001707 polybutylene terephthalate Polymers 0.000 claims description 3
- 229920000139 polyethylene terephthalate Polymers 0.000 claims description 3
- 239000005020 polyethylene terephthalate Substances 0.000 claims description 3
- 229920006122 polyamide resin Polymers 0.000 claims 2
- 229910001873 dinitrogen Inorganic materials 0.000 claims 1
- 239000011261 inert gas Substances 0.000 abstract description 6
- 230000008025 crystallization Effects 0.000 description 18
- 239000000463 material Substances 0.000 description 14
- 239000004698 Polyethylene Substances 0.000 description 5
- 229920000573 polyethylene Polymers 0.000 description 5
- 230000009477 glass transition Effects 0.000 description 4
- 229910052757 nitrogen Inorganic materials 0.000 description 3
- 229920000728 polyester Polymers 0.000 description 3
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 2
- 239000003484 crystal nucleating agent Substances 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 239000011810 insulating material Substances 0.000 description 2
- 238000004898 kneading Methods 0.000 description 2
- 239000003607 modifier Substances 0.000 description 2
- 238000000465 moulding Methods 0.000 description 2
- 230000000704 physical effect Effects 0.000 description 2
- 229920000098 polyolefin Polymers 0.000 description 2
- 229920006124 polyolefin elastomer Polymers 0.000 description 2
- 238000009738 saturating Methods 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- 239000005995 Aluminium silicate Substances 0.000 description 1
- 229920006065 Leona® Polymers 0.000 description 1
- 239000004952 Polyamide Substances 0.000 description 1
- 239000004743 Polypropylene Substances 0.000 description 1
- 239000004793 Polystyrene Substances 0.000 description 1
- 238000002441 X-ray diffraction Methods 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- 239000003570 air Substances 0.000 description 1
- 235000012211 aluminium silicate Nutrition 0.000 description 1
- 239000003963 antioxidant agent Substances 0.000 description 1
- 239000002216 antistatic agent Substances 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 239000004566 building material Substances 0.000 description 1
- 125000003178 carboxy group Chemical group [H]OC(*)=O 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 238000000113 differential scanning calorimetry Methods 0.000 description 1
- 239000000975 dye Substances 0.000 description 1
- 150000002148 esters Chemical class 0.000 description 1
- 239000000835 fiber Substances 0.000 description 1
- 239000004088 foaming agent Substances 0.000 description 1
- 238000007654 immersion Methods 0.000 description 1
- 239000003112 inhibitor Substances 0.000 description 1
- 150000002484 inorganic compounds Chemical class 0.000 description 1
- 229910010272 inorganic material Inorganic materials 0.000 description 1
- 238000009413 insulation Methods 0.000 description 1
- NLYAJNPCOHFWQQ-UHFFFAOYSA-N kaolin Chemical compound O.O.O=[Al]O[Si](=O)O[Si](=O)O[Al]=O NLYAJNPCOHFWQQ-UHFFFAOYSA-N 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 239000000314 lubricant Substances 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 239000010445 mica Substances 0.000 description 1
- 229910052618 mica group Inorganic materials 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- JCXJVPUVTGWSNB-UHFFFAOYSA-N nitrogen dioxide Inorganic materials O=[N]=O JCXJVPUVTGWSNB-UHFFFAOYSA-N 0.000 description 1
- 150000002894 organic compounds Chemical class 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 239000005022 packaging material Substances 0.000 description 1
- 239000008188 pellet Substances 0.000 description 1
- 239000000049 pigment Substances 0.000 description 1
- 239000004014 plasticizer Substances 0.000 description 1
- 229920001515 polyalkylene glycol Polymers 0.000 description 1
- 229920002647 polyamide Polymers 0.000 description 1
- 229920000642 polymer Chemical class 0.000 description 1
- 229920001155 polypropylene Polymers 0.000 description 1
- 229920002223 polystyrene Polymers 0.000 description 1
- 238000011084 recovery Methods 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- 239000000377 silicon dioxide Substances 0.000 description 1
- 239000000454 talc Substances 0.000 description 1
- 229910052623 talc Inorganic materials 0.000 description 1
Abstract
Description
【０００１】0001
【産業上の利用分野】本発明は保温材、断熱材などの材
料として好適な熱可塑性樹脂発泡体の製造方法に関する
。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a thermoplastic resin foam suitable as a material for heat insulating materials, heat insulating materials, and the like.
【０００２】0002
【従来の技術】従来、ポリエチレン、ポリスチレン、ポ
リプロピレンなどの熱可塑性樹脂の発泡体が、それらが
有する柔軟性、軽量性、断熱性などの特徴を活かして、
建材や包装材などに広く用いられている。しかし、これ
らの発泡体は、機械的強度、弾性回復率、耐熱性などが
不十分であるという問題がある。また、バルク状態で前
述した樹脂よりも機械的性質に優れているポリエステル
の発泡体も製造されているが、その機械的性質は不十分
である。[Prior Art] Conventionally, thermoplastic resin foams such as polyethylene, polystyrene, and polypropylene have been used to make use of their characteristics such as flexibility, lightness, and heat insulation.
It is widely used for building materials and packaging materials. However, these foams have problems such as insufficient mechanical strength, elastic recovery rate, and heat resistance. Polyester foams have also been produced which have better mechanical properties in bulk than the aforementioned resins, but their mechanical properties are inadequate.
【０００３】これらの発泡体は主に、樹脂に発泡剤を混
和し、成形と同時に、または一旦成形した後、加熱して
発泡させる方法により製造されている。しかし、この方
法により得られた発泡体では、含有される気泡が不均質
でかつ大きくなり過ぎるため、機械的性質を十分に満足
できない。[0003] These foams are mainly manufactured by mixing a foaming agent with a resin and foaming the mixture by heating at the same time as molding or after molding. However, in the foam obtained by this method, the bubbles contained are inhomogeneous and too large, so that the mechanical properties cannot be fully satisfied.
【０００４】このほかに、樹脂発泡体の製造方法として
は、以下のような方法が知られている。例えば、高圧下
で不活性ガスを含有させた樹脂ペレットを押出機へ供給
し、溶融して混練りした後、大気中へ押し出すことによ
り発泡体を得る方法がある（特公昭５３−２８１８９号
公報、特公昭５４−２３３８６号公報）。また、押出機
内で溶融状態にある樹脂に、バレルの途中から不活性ガ
スを注入し、十分に混練りした後、大気中へ押し出すこ
とにより発泡体を得る方法がある。[0004] In addition, the following methods are known as methods for producing resin foams. For example, there is a method of obtaining a foam by supplying resin pellets containing an inert gas to an extruder under high pressure, melting and kneading them, and then extruding them into the atmosphere (Japanese Patent Publication No. 53-28189). , Japanese Patent Publication No. 54-23386). Another method is to obtain a foam by injecting an inert gas into the resin in a molten state in an extruder from the middle of the barrel, thoroughly kneading the resin, and then extruding the resin into the atmosphere.
【０００５】しかし、これらの方法は、溶融状態の樹脂
を急激に大気中へ押し出して発泡体を製造するものであ
るため、樹脂中での気泡の成長速度が大きく、微細な気
泡を含有する発泡体は得られない。However, since these methods produce foam by rapidly extruding molten resin into the atmosphere, the growth rate of bubbles in the resin is high, and foams containing fine bubbles cannot be produced. I can't get the body.
【０００６】米国特許第４，４７３，６６５号には、（
１）加圧下において予め成形された高分子材料をアルゴ
ン、窒素、二酸化炭素などの不活性ガスで飽和させ、こ
れをガラス転移温度まで加熱し、材料を減圧にすること
により材料中でガスの過飽和状態を作り出して気泡核を
生成させると同時に気泡を成長させ、気泡の成長を抑え
るために材料の温度を急激に下げる方法、（２）加圧下
において予め成形された高分子材料を非反応性ガスで飽
和させ、材料がガスで過飽和状態になるまで減圧して気
泡核を生成させ、これをガラス転移温度に加熱して気泡
を成長させ、気泡の成長を抑えるために材料の温度を急
激に下げる方法、または（３）加圧下において高分子材
料を不活性ガスで飽和させ、十分な高圧下で高分子材料
を溶融して成形し、材料がガスで過飽和状態になるまで
温度および圧力を下げて気泡核を生成させ、これをガラ
ス転移温度に加熱して気泡を成長させ、気泡の成長を抑
えるために材料の温度を急激に下げる方法、などが開示
されている。[0006] US Patent No. 4,473,665 has (
1) Supersaturation of the gas in the material by saturating a preformed polymeric material with an inert gas such as argon, nitrogen, or carbon dioxide under pressure, heating it to the glass transition temperature, and reducing the pressure of the material. (2) A method of rapidly lowering the temperature of the material to suppress the growth of bubbles by creating a state in which bubble nuclei are generated and the bubbles grow at the same time. The material is saturated with gas, the pressure is reduced until the material is supersaturated with gas to generate bubble nuclei, which are heated to the glass transition temperature to grow bubbles, and the temperature of the material is rapidly lowered to suppress bubble growth. or (3) saturating the polymeric material with an inert gas under pressure, melting and forming the polymeric material under sufficiently high pressure, and reducing the temperature and pressure until the material is supersaturated with the gas. A method has been disclosed in which bubble nuclei are generated, the bubbles are grown by heating them to a glass transition temperature, and the temperature of the material is rapidly lowered to suppress the bubble growth.
【０００７】[0007]
【発明が解決しようとする課題】この方法により得られ
た発泡体は、非常に微細な気泡を含むものである。しか
し、この方法で得られた発泡体を高温で使用すると、変
形や収縮が生じやすいという問題がある。これは、以下
のような理由による。すなわち、前記のいずれの方法に
おいても、気泡核を成長させて気泡を形成させる温度が
ガラス転移温度付近であるため、得られた発泡体の結晶
化が十分に進行していない。このような発泡体を高温の
雰囲気にさらすと、結晶化が進行するため変形や収縮が
生じやすくなる。[Problems to be Solved by the Invention] The foam obtained by this method contains very fine cells. However, when the foam obtained by this method is used at high temperatures, there is a problem in that it tends to deform and shrink. This is due to the following reasons. That is, in any of the above methods, the temperature at which bubble nuclei are grown and bubbles are formed is around the glass transition temperature, so crystallization of the obtained foam does not proceed sufficiently. When such a foam is exposed to a high temperature atmosphere, crystallization progresses, making it susceptible to deformation and shrinkage.
【０００８】以上述べたように、現状では、微細な気泡
を有し、高温で使用しても変形や収縮の小さい熱可塑性
樹脂発泡体を得ることは困難である。As described above, it is currently difficult to obtain thermoplastic resin foams that have fine bubbles and exhibit little deformation or shrinkage even when used at high temperatures.
【０００９】本発明の目的は、無数の微細な気泡を含有
し、高温雰囲気においても変形や収縮が非常に小さい熱
可塑性樹脂発泡体を製造できる方法を提供することにあ
る。[0009] An object of the present invention is to provide a method for producing a thermoplastic resin foam that contains countless microscopic cells and exhibits very little deformation or shrinkage even in a high-temperature atmosphere.
【００１０】0010
【課題を解決するための手段】本発明の熱可塑性樹脂発
泡体の製造方法は、加圧下において、熱可塑性樹脂中に
非反応性ガスを含有させる工程（以下、「第１工程」と
いう）と、非加圧下において、得られた熱可塑性樹脂を
、示差走査熱量計により測定されるその樹脂の結晶化ピ
ーク温度以上かつ融点ピーク温度以下の温度範囲で加熱
して発泡させる工程（以下、「第２工程」という）と、
得られた熱可塑性樹脂を冷却する工程（以下、「第３工
程」という）とを有するものである。[Means for Solving the Problems] The method for producing a thermoplastic resin foam of the present invention includes a step of incorporating a non-reactive gas into a thermoplastic resin under pressure (hereinafter referred to as the "first step"). , a step of foaming the obtained thermoplastic resin by heating it under no pressure in a temperature range that is higher than the crystallization peak temperature and lower than the melting point peak temperature of the resin as measured by a differential scanning calorimeter (hereinafter referred to as "step 1"). 2 steps) and
The method includes a step of cooling the obtained thermoplastic resin (hereinafter referred to as "third step").
【００１１】本発明においては、第２工程の発泡処理を
熱可塑性樹脂の半結晶化時間が５分以下である温度範囲
において行うことが好ましい。In the present invention, it is preferable that the second step of foaming treatment is carried out in a temperature range in which the half-crystallization time of the thermoplastic resin is 5 minutes or less.
【００１２】以下、本発明の製造方法を工程毎に詳細に
説明する。The manufacturing method of the present invention will be explained step by step in detail below.
【００１３】第１工程は、加圧下において熱可塑性樹脂
中に非反応性ガスを含有させる工程である。この工程で
いう含有とは、例えば、液体中に非反応性ガスが溶解し
たのと同様の状態をいう。The first step is a step of incorporating a non-reactive gas into the thermoplastic resin under pressure. Containment in this step refers to, for example, a state similar to that in which a non-reactive gas is dissolved in the liquid.
【００１４】この処理は、例えば予め成形された熱可塑
性樹脂を、非反応性ガスで加圧された加圧容器中に入れ
ることにより行われる。また、押出機などで熱可塑性樹
脂を押出成形しながら、非反応性ガスで加圧された加圧
容器に導く方法を用いてもよい。[0014] This treatment is carried out, for example, by placing a pre-shaped thermoplastic resin into a pressurized container pressurized with a non-reactive gas. Alternatively, a method may be used in which the thermoplastic resin is extruded using an extruder or the like and introduced into a pressurized container pressurized with a non-reactive gas.
【００１５】加圧条件は特に制限されるものではないが
、熱可塑性樹脂中への非反応性ガスの含有量を増大させ
るためには、室温で３０〜７０ｋｇ／ｃｍ２ の範囲の
圧力とすることが好ましい。[0015] Pressurization conditions are not particularly limited, but in order to increase the content of non-reactive gas in the thermoplastic resin, the pressure should be in the range of 30 to 70 kg/cm2 at room temperature. is preferred.
【００１６】熱可塑性樹脂としては、ポリエチレンテレ
フタレートまたはポリブチレンテレフタレートなどのポ
リエステル、ナイロン６またはナイロン６６などのポリ
アミドが挙げられる。Examples of thermoplastic resins include polyesters such as polyethylene terephthalate or polybutylene terephthalate, and polyamides such as nylon 6 or nylon 66.
【００１７】微細な気泡を含有する発泡体を得るために
は、熱可塑性樹脂は、結晶化度が５％以上のものが好ま
しく、１０％以上のものが更に好ましい。なお、樹脂の
結晶化度は、密度法（ＡＳＴＭ Ｄ１５０５−８５）
、示差走査熱量計による方法、ＩＲによる方法、Ｘ線回
折による方法を用いて測定できる。また、結晶化度また
は結晶化速度を上げるために、熱可塑性樹脂に結晶核剤
または結晶化促進剤を添加してもよい。結晶核剤または
結晶化促進剤としては、タルク、マイカ、カオリン、シ
リカなどの無機化合物、カルボキシル基を有する有機化
合物もしくは高分子化合物の金属塩、ポリオレフィンに
変性剤を添加して変性させた変性ポリオレフィン、ポリ
オレフィン系エラストマーに変性剤を添加して変性させ
た変性ポリオレフィン系エラストマー、エステル系可塑
剤などが挙げられる。更に、本発明の目的を損なわない
範囲内で、熱可塑性樹脂に抗酸化剤、帯電防止剤、紫外
線防止剤、顔料、染料、滑剤などの各種添加剤を配合す
ることもできる。In order to obtain a foam containing fine cells, the thermoplastic resin preferably has a crystallinity of 5% or more, more preferably 10% or more. The crystallinity of the resin is determined by the density method (ASTM D1505-85).
, a method using differential scanning calorimetry, a method using IR, and a method using X-ray diffraction. Furthermore, a crystal nucleating agent or a crystallization accelerator may be added to the thermoplastic resin in order to increase the crystallinity or crystallization rate. Examples of crystal nucleating agents or crystallization accelerators include inorganic compounds such as talc, mica, kaolin, and silica, metal salts of organic compounds or polymeric compounds having carboxyl groups, and modified polyolefins obtained by adding a modifier to polyolefins. , a modified polyolefin elastomer obtained by adding a modifier to a polyolefin elastomer, and an ester plasticizer. Furthermore, various additives such as antioxidants, antistatic agents, ultraviolet inhibitors, pigments, dyes, and lubricants may be added to the thermoplastic resin within a range that does not impair the purpose of the present invention.
【００１８】非反応性ガスとしては、アルゴン、窒素、
二酸化炭素などの不活性ガス、もしくは酸素、空気、ま
たはこれらの混合ガスが挙げられる。これらの中でも、
熱可塑性樹脂中への含有量を最も増大できるガスとして
、二酸化炭素が好ましい。[0018] As the non-reactive gas, argon, nitrogen,
Examples include inert gas such as carbon dioxide, oxygen, air, or a mixed gas thereof. Among these,
Carbon dioxide is preferred as the gas that can most increase the content in the thermoplastic resin.
【００１９】第２工程は、非加圧下において、非反応性
ガスが含有された熱可塑性樹脂を加熱して発泡させる工
程である。この工程においては、非加圧下、即ち、加圧
容器から取り出すなどして圧力を解放する。この結果、
樹脂は非反応性ガスで過飽和の状態になる。その後、樹
脂を直ちに加熱して発泡させる。このときの発泡温度は
、示差走査熱量計（ＤＳＣ）により測定される熱可塑性
樹脂の結晶化ピーク温度以上で融点ピーク温度以下の温
度範囲に設定される。温度範囲をこのように規定したの
は、樹脂中での気泡の成長と同時に、樹脂の結晶化を進
行させるためである。The second step is a step of heating and foaming the thermoplastic resin containing a non-reactive gas under non-pressurized conditions. In this step, the pressure is released under non-pressurized conditions, ie, by taking it out from the pressurized container. As a result,
The resin becomes supersaturated with non-reactive gases. Thereafter, the resin is immediately heated and foamed. The foaming temperature at this time is set in a temperature range that is higher than the crystallization peak temperature of the thermoplastic resin and lower than the melting point peak temperature, as measured by a differential scanning calorimeter (DSC). The reason why the temperature range is defined in this way is to promote the crystallization of the resin at the same time as the growth of bubbles in the resin.
【００２０】この温度範囲外であると、樹脂の結晶化が
十分に進行せず、樹脂中で独立した微細な気泡を形成す
ることができない。このため、得られた発泡体を高温で
使用したときに、結晶化が進行して変形や収縮を生じや
すい。特に、融点ピーク温度を超える温度で発泡させる
と、気泡数が著しく減少するうえ、気泡径が大きくなり
すぎて、発泡過程においても変形を生じる。[0020] If the temperature is outside this range, the crystallization of the resin will not proceed sufficiently, making it impossible to form independent fine bubbles in the resin. Therefore, when the obtained foam is used at high temperatures, crystallization progresses and deformation and shrinkage tend to occur. In particular, when foaming is carried out at a temperature exceeding the peak melting point temperature, the number of cells decreases significantly and the cell diameter becomes too large, causing deformation during the foaming process.
【００２１】ただし、結晶化ピーク温度および融点ピー
ク温度は、示差走査熱量計による測定条件、特に昇温速
度に大きく依存し、相対的な値しか求められない。この
ため、良好な物性を有する発泡体を得るための精密な製
造条件を確立するには適当でない。[0021] However, the crystallization peak temperature and the melting point peak temperature largely depend on the measurement conditions by the differential scanning calorimeter, especially on the rate of temperature rise, and only relative values can be determined. Therefore, it is not suitable for establishing precise manufacturing conditions for obtaining a foam with good physical properties.
【００２２】そこで、加熱による発泡処理は、熱可塑性
樹脂の半結晶化時間が５分以下である温度範囲で行うこ
とがより好ましい。半結晶化時間（τ）とは、熱可塑性
樹脂が結晶化する際に、到達結晶化度の半分の結晶化度
が得られる時間のことであり、結晶化速度を表す値とし
て一般的に用いられている。[0022] Therefore, it is more preferable that the foaming treatment by heating is carried out in a temperature range in which the half-crystallization time of the thermoplastic resin is 5 minutes or less. Half-crystalization time (τ) is the time required to obtain half the crystallinity of the final crystallinity when a thermoplastic resin crystallizes, and is generally used as a value representing the crystallization rate. It is being
【００２３】半結晶化時間（τ）は、以下のようにして
測定できる。熱可塑性樹脂を所定の温度（例えば２００
℃）雰囲気下に保持する。所定時間ごとに熱可塑性樹脂
の結晶化度を測定し、経過時間と結晶化度の関係を作図
する。その図から、到達結晶化度の半分の結晶化度が得
られる時間を決定する。Half crystallization time (τ) can be measured as follows. The thermoplastic resin is heated to a predetermined temperature (for example, 200
°C) kept under atmosphere. The degree of crystallinity of the thermoplastic resin is measured at predetermined intervals, and the relationship between the elapsed time and the degree of crystallinity is plotted. From the diagram, determine the time required to obtain half the crystallinity of the achieved crystallinity.
【００２４】この操作を種々の温度で行い、温度と半結
晶化時間との関係を作図する。この図から、半結晶化時
間が５分以下となる温度範囲を決定できる。This operation is carried out at various temperatures, and the relationship between temperature and half-crystallization time is plotted. From this figure, it is possible to determine the temperature range in which the half-crystallization time is 5 minutes or less.
【００２５】なお、詳細は“ポリエステル繊維、Ｈ．Ｌ
ｕｄｅｗｉｎｇ原著、横内澪、中村至（訳）、ｐ．１０
１、コロナ社、１９６７年”、または“飽和ポリエステ
ル樹脂ハンドブック、湯木和男編集、ｐ．２１９、日刊
工業新聞社、１９８９年）に記載されている。[0025]For details, refer to "Polyester fiber, H.L.
udewing original author, Mio Yokouchi, Itaru Nakamura (translators), p. 10
1, Corona Publishing, 1967" or "Saturated Polyester Resin Handbook, edited by Kazuo Yuki, p. 219, Nikkan Kogyo Shimbun, 1989).
【００２６】ガスを含有する熱可塑性樹脂を半結晶化時
間（τ）が５分以下となるような温度範囲で加熱して発
泡させると、結晶化速度が速いため、気泡の成長よりも
結晶化の方が先に進行する。この結晶化に伴って樹脂の
剛性が上がるため、気泡の巨大化が抑制され、微細な気
泡を含有する発泡体が得られる。When a gas-containing thermoplastic resin is heated and foamed in a temperature range in which the half-crystallization time (τ) is 5 minutes or less, the crystallization rate is faster, so crystallization occurs faster than bubble growth. will proceed first. Since the rigidity of the resin increases with this crystallization, the enlargement of the bubbles is suppressed, and a foam containing fine bubbles is obtained.
【００２７】発泡温度がこの範囲外では、微細な気泡を
含有する発泡体が得られない。すなわち、高温側では樹
脂の剛性が低下しているうえ、結晶化が進行しないため
、気泡の成長を抑制することができず、気泡が著しく大
きくなる。一方、低温側でも結晶化があまり進行しない
。また、もともと樹脂の剛性が非常に高い場合には、低
温側では気泡がほとんど成長せず、発泡倍率が大きくな
らないこともある。[0027] If the foaming temperature is outside this range, a foam containing fine cells cannot be obtained. That is, on the high temperature side, the rigidity of the resin is reduced and crystallization does not proceed, so the growth of bubbles cannot be suppressed and the bubbles become significantly larger. On the other hand, crystallization does not progress much even at low temperatures. Furthermore, if the resin has very high rigidity to begin with, the foaming ratio may not increase because the bubbles hardly grow on the low temperature side.
【００２８】加熱時間は、熱可塑性樹脂の熱容量、およ
び含有させた非反応性ガスの量などを考慮して適宜設定
する。The heating time is appropriately set in consideration of the heat capacity of the thermoplastic resin and the amount of non-reactive gas contained.
【００２９】第３工程は、加熱して発泡終了後、冷却す
る工程である。この工程における冷却処理としては、冷
水に浸漬するなどの公知の手段を適用できる。The third step is a step of cooling after heating and foaming. As the cooling treatment in this step, known means such as immersion in cold water can be applied.
【００３０】[0030]
【実施例】以下、本発明の実施例を説明する。[Examples] Examples of the present invention will be described below.
【００３１】実施例１〜７及び比較例１〜２熱可塑性樹
脂として、ポリエチレンテレフタレート−Ａ（ユニチカ
株式会社製、商品名ＭＡ−２１０３−４）、ポリエチレ
ンテレフタレート−Ｂ（ユニチカ株式会社製、商品名Ｍ
Ａ−２１０３−２）、ポリエチレンテレフタレート−Ｃ
（ユニチカ株式会社製、商品名ＭＡ−２１０３−３）、
ポリブチレンテレフタレート（東レ株式会社製、商品名
１４０１−Ｘ０４）、ナイロン６（東レ株式会社製、商
品名ＣＭ−１０４６）、ナイロン６６（旭化成工業株式
会社製、商品名レオナ）を用いた。これらの熱可塑性樹
脂の物性を表１および表２に示す。また、ポリエチレン
テレフタレート−Ａについて、温度と半結晶化時間との
関係を図１に示す。Examples 1 to 7 and Comparative Examples 1 to 2 As thermoplastic resins, polyethylene terephthalate-A (manufactured by Unitika Co., Ltd., trade name MA-2103-4), polyethylene terephthalate-B (manufactured by Unitika Co., Ltd., trade name M
A-2103-2), polyethylene terephthalate-C
(manufactured by Unitika Co., Ltd., product name MA-2103-3),
Polybutylene terephthalate (manufactured by Toray Industries, Inc., trade name 1401-X04), nylon 6 (manufactured by Toray Industries, Inc., trade name CM-1046), and nylon 66 (manufactured by Asahi Kasei Corporation, trade name Leona) were used. The physical properties of these thermoplastic resins are shown in Tables 1 and 2. Further, for polyethylene terephthalate-A, the relationship between temperature and half-crystallization time is shown in FIG.
【００３２】各熱可塑性樹脂を押出成形し、厚さ１ｍｍ
のシートを成形した。得られた各シートを、オートクレ
ーブ中で、６０ｋｇ／ｃｍ２ の圧力下、１２時間保持
し、シート中に二酸化炭素を含有させた。その後、オー
トクレーブからシートを取り出し、直ちに熱媒であるポ
リアルキレングリコール中に１分間浸漬し、表１および
表２に記載の温度に加熱して発泡させた。発泡終了後、
シートを水に浸漬して冷却し、シート状の熱可塑性樹脂
発泡体を得た。[0032] Each thermoplastic resin was extruded to a thickness of 1 mm.
A sheet was formed. Each sheet obtained was held in an autoclave under a pressure of 60 kg/cm2 for 12 hours to incorporate carbon dioxide into the sheet. Thereafter, the sheet was taken out from the autoclave, immediately immersed in polyalkylene glycol as a heating medium for 1 minute, and heated to the temperatures listed in Tables 1 and 2 to cause foaming. After foaming is finished,
The sheet was immersed in water and cooled to obtain a sheet-like thermoplastic resin foam.
【００３３】得られた各発泡体について、密度、発泡倍
率および平均気泡径を調べた。発泡倍率は、未発泡体お
よび発泡体の密度の比を計算することにより算出した。
平均気泡径は以下のようにして測定した。まず発泡体の
断面を走査型電子顕微鏡により写真撮影し、一定面積内
に存在する気泡の数を数えた。その値をもとにして単位
体積当たりの気泡の数を算出した。その値と発泡倍率か
ら計算により平均気泡径を算出した。[0033] The density, expansion ratio and average cell diameter of each of the obtained foams were examined. The expansion ratio was calculated by calculating the ratio of the densities of the unfoamed material and the foamed material. The average bubble diameter was measured as follows. First, a cross-section of the foam was photographed using a scanning electron microscope, and the number of bubbles present within a certain area was counted. Based on that value, the number of bubbles per unit volume was calculated. The average cell diameter was calculated from that value and the expansion ratio.
【００３４】また、各発泡体を１５０℃に設定した恒温
槽中に２２時間放置した後、目視により変形状況を調べ
、更に収縮率を調べた。熱収縮率は、恒温槽中への放置
する前と放置した後の発泡体の体積比から算出した。[0034] Furthermore, after each foam was left in a constant temperature bath set at 150°C for 22 hours, the state of deformation was visually examined, and the shrinkage rate was also examined. The thermal shrinkage rate was calculated from the volume ratio of the foam before and after being left in a constant temperature bath.
【００３５】これらの結果を表１および表２に示す。These results are shown in Tables 1 and 2.
【００３６】表１および表２から、本発明の方法で得ら
れた熱可塑性樹脂発泡体は、１５０℃以上の高温雰囲気
中に長時間放置した場合でも、変形がなく、収縮も非常
に小さいことがわかる。From Tables 1 and 2, it can be seen that the thermoplastic resin foam obtained by the method of the present invention does not deform and shrinks very little even when left in a high temperature atmosphere of 150° C. or higher for a long time. I understand.
【００３７】[0037]
【表１】[Table 1]
【００３８】[0038]
【表２】[Table 2]
【００３９】実施例８、９
熱可塑性樹脂としてＰＥＴ−Ｃを用いた。非反応性ガス
として二酸化炭素の代りに窒素またはアルゴンを用いた
以外は、前記と同様にして発泡体を得た。Examples 8 and 9 PET-C was used as the thermoplastic resin. A foam was obtained in the same manner as above except that nitrogen or argon was used instead of carbon dioxide as the non-reactive gas.
【００４０】得られた各発泡体について、密度、発泡倍
率および平均気泡径を調べた。また、各発泡体を１５０
℃に設定した恒温槽中に２２時間放置した後、目視によ
り変形状況を調べ、更に収縮率を調べた。これらの結果
を表３に示す。The density, expansion ratio and average cell diameter of each of the foams obtained were examined. Also, each foam is 150
After being left in a constant temperature bath set at ℃ for 22 hours, the state of deformation was visually checked, and the shrinkage rate was also checked. These results are shown in Table 3.
【００４１】[0041]
【表３】[Table 3]
【００４２】表３から、非反応性ガスとして窒素または
アルゴンを用いた場合でも、二酸化炭素を同様な効果が
得られることがわかる。Table 3 shows that even when nitrogen or argon is used as the non-reactive gas, the same effect as carbon dioxide can be obtained.
【００４３】[0043]
【発明の効果】以上詳述したように本発明の方法を用い
れば、非常に微細な気泡を無数に含有した熱可塑性樹脂
発泡体を得ることができる。そして、得られた熱可塑性
樹脂発泡体は、高温雰囲気中に長時間放置した場合でも
、熱による変形はなく、収縮も非常に小さい。[Effects of the Invention] As described in detail above, by using the method of the present invention, it is possible to obtain a thermoplastic resin foam containing numerous extremely fine cells. Even when the obtained thermoplastic resin foam is left in a high-temperature atmosphere for a long time, it does not deform due to heat and shrinks very little.
【図１】ポリエチレンテレフタレートについて温度と半
結晶化時間τとの関係を示す図。FIG. 1 is a diagram showing the relationship between temperature and half-crystalization time τ for polyethylene terephthalate.
Claims (9)
反応性ガスを含有させる工程と、非加圧下において、得
られた熱可塑性樹脂を、示差走査熱量計により測定され
るその樹脂の結晶化ピーク温度以上かつ融点ピーク温度
以下の温度範囲で加熱して発泡させる工程と、得られた
熱可塑性樹脂を冷却する工程とを具備したことを特徴と
する熱可塑性樹脂発泡体の製造方法。Claim 1: A step of incorporating a non-reactive gas into a thermoplastic resin under pressure, and a step of crystallizing the obtained thermoplastic resin as measured by a differential scanning calorimeter under no pressure. A method for producing a thermoplastic resin foam, comprising the steps of heating and foaming at a temperature range above a peak temperature and below a peak melting point temperature, and cooling the obtained thermoplastic resin.
程が、その樹脂の半結晶化時間が５分以下である温度範
囲で行われることを特徴とする請求項１記載の熱可塑性
樹脂発泡体の製造方法。2. The thermoplastic resin foam according to claim 1, wherein the step of heating and foaming the thermoplastic resin is carried out in a temperature range in which the semi-crystallization time of the resin is 5 minutes or less. manufacturing method.
脂であることを特徴とする請求項１記載の熱可塑性樹脂
発泡体の製造方法。3. The method for producing a thermoplastic resin foam according to claim 1, wherein the thermoplastic resin is a saturated polyester resin.
ンテレフタレートまたはポリブチレンテレフタレートで
あることを特徴とする請求項３記載の熱可塑性樹脂発泡
体の製造方法。4. The method for producing a thermoplastic resin foam according to claim 3, wherein the saturated polyester resin is polyethylene terephthalate or polybutylene terephthalate.
ることを特徴とする請求項１記載の熱可塑性樹脂発泡体
の製造方法。5. The method for producing a thermoplastic resin foam according to claim 1, wherein the thermoplastic resin is a polyamide resin.
ナイロン６６であることを特徴とする請求項５記載の熱
可塑性樹脂発泡体の製造方法。6. The method for producing a thermoplastic resin foam according to claim 5, wherein the polyamide resin is nylon 6 or nylon 66.
せるときの圧力が、室温で３０〜７０ｋｇ／ｃｍ２ の
範囲であることを特徴とする請求項１記載の熱可塑性樹
脂発泡体の製造方法。7. The method for producing a thermoplastic resin foam according to claim 1, wherein the pressure at which the non-reactive gas is contained in the thermoplastic resin is in the range of 30 to 70 kg/cm2 at room temperature. .
またはアルゴンガスであることを特徴とする請求項１記
載の熱可塑性樹脂発泡体の製造方法。8. The method for producing a thermoplastic resin foam according to claim 1, wherein the non-reactive gas is carbon dioxide gas, nitrogen gas or argon gas.
囲の加圧下において、密度法または示差走査熱量計によ
り測定される結晶化度が１０％以上の飽和ポリエステル
樹脂中に炭酸ガスを含有させる工程と、非加圧下におい
て、得られた飽和ポリエステル樹脂を、１３５〜２３０
℃の温度範囲において加熱して発泡させる工程と、得ら
れた飽和ポリエステル樹脂を冷却する工程とを具備した
ことを特徴とする熱可塑性樹脂発泡体の製造方法。9. A step of incorporating carbon dioxide gas into a saturated polyester resin having a crystallinity of 10% or more as measured by a density method or a differential scanning calorimeter under a pressure in the range of 30 to 70 kg/cm2 at room temperature; , under no pressure, the obtained saturated polyester resin was heated to 135 to 230
1. A method for producing a thermoplastic resin foam, comprising the steps of foaming by heating in a temperature range of 0.degree. C., and cooling the obtained saturated polyester resin.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP23310891A JP3061213B2 (en) | 1990-09-17 | 1991-09-12 | Method for producing thermoplastic resin foam |
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2-246726 | 1990-09-17 | ||
| JP24672690 | 1990-09-17 | ||
| JP23310891A JP3061213B2 (en) | 1990-09-17 | 1991-09-12 | Method for producing thermoplastic resin foam |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH04356540A true JPH04356540A (en) | 1992-12-10 |
| JP3061213B2 JP3061213B2 (en) | 2000-07-10 |
Family
ID=26530851
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP23310891A Expired - Lifetime JP3061213B2 (en) | 1990-09-17 | 1991-09-12 | Method for producing thermoplastic resin foam |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3061213B2 (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6095515A (en) * | 1983-09-26 | 1985-05-28 | テクトロニツクス・インコーポレイテツド | Color filter |
| WO2006077395A1 (en) * | 2005-01-18 | 2006-07-27 | Zotefoams Plc | Polyamide foams, process to make them and applications thereof |
| JP2010270238A (en) * | 2009-05-22 | 2010-12-02 | Toyobo Co Ltd | Resin composition for foamed molding, resin sheet for foamed molding, and foamed molding |
| JP2011074200A (en) * | 2009-09-30 | 2011-04-14 | Sekisui Chem Co Ltd | Method for producing thermoplastic resin foam |
| JP2015098587A (en) * | 2013-10-18 | 2015-05-28 | 積水化成品工業株式会社 | Thermoplastic polyester resin foam particles and method for producing the same, foam molding and method for producing the same, and composite foam |
-
1991
- 1991-09-12 JP JP23310891A patent/JP3061213B2/en not_active Expired - Lifetime
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6095515A (en) * | 1983-09-26 | 1985-05-28 | テクトロニツクス・インコーポレイテツド | Color filter |
| WO2006077395A1 (en) * | 2005-01-18 | 2006-07-27 | Zotefoams Plc | Polyamide foams, process to make them and applications thereof |
| JP2010270238A (en) * | 2009-05-22 | 2010-12-02 | Toyobo Co Ltd | Resin composition for foamed molding, resin sheet for foamed molding, and foamed molding |
| JP2011074200A (en) * | 2009-09-30 | 2011-04-14 | Sekisui Chem Co Ltd | Method for producing thermoplastic resin foam |
| JP2015098587A (en) * | 2013-10-18 | 2015-05-28 | 積水化成品工業株式会社 | Thermoplastic polyester resin foam particles and method for producing the same, foam molding and method for producing the same, and composite foam |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3061213B2 (en) | 2000-07-10 |
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