JP2008222883A - Polylactic acid resin composition and method for producing the same - Google Patents

Polylactic acid resin composition and method for producing the same Download PDF

Info

Publication number
JP2008222883A
JP2008222883A JP2007064181A JP2007064181A JP2008222883A JP 2008222883 A JP2008222883 A JP 2008222883A JP 2007064181 A JP2007064181 A JP 2007064181A JP 2007064181 A JP2007064181 A JP 2007064181A JP 2008222883 A JP2008222883 A JP 2008222883A
Authority
JP
Japan
Prior art keywords
polylactic acid
resin composition
acid resin
type polyisocyanate
polybutylene succinate
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
Application number
JP2007064181A
Other languages
Japanese (ja)
Other versions
JP4977890B2 (en
Inventor
Hiroshi Iida
浩史 飯田
Tadashi Harada
征 原田
Hideki Hayashi
英樹 林
Kazuaki Okamoto
岡本和明
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.)
CITY OF NAGOYA
Original Assignee
CITY OF NAGOYA
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 CITY OF NAGOYA filed Critical CITY OF NAGOYA
Priority to JP2007064181A priority Critical patent/JP4977890B2/en
Publication of JP2008222883A publication Critical patent/JP2008222883A/en
Application granted granted Critical
Publication of JP4977890B2 publication Critical patent/JP4977890B2/en
Expired - Fee Related legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polylactic acid resin composition hardly causing sink or strain in a molded product with a low shear viscosity when hot molten and having excellent compatibility, dispersibility, flexibility and impact resistance and to provide a method for producing the composition. <P>SOLUTION: The polylactic acid resin composition is obtained by cross-linking polylactic acid and polybutylene succinate using an isocyanurate type polyisocyanate as a cross-linking agent. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

本発明は、相溶性、分散性、柔軟性及び耐衝撃性に優れ、成形品に引けや歪が生じ難いポリ乳酸系樹脂組成物及びその製造方法に関する。   The present invention relates to a polylactic acid resin composition that is excellent in compatibility, dispersibility, flexibility, and impact resistance, and that hardly causes shrinkage or distortion in a molded product, and a method for producing the same.

近年、環境保護の見地から、自然環境中で微生物等により分解され得る生分解性樹脂が注目を集めている。こうした生分解性樹脂の具体例として、例えばポリ乳酸、ポリカプロラクトン、ポリブチレンサクシネート、ポリエチレンサクシネート等の溶融成形加工が可能な生分解性樹脂が挙げられる。その中でも、ポリ乳酸は融点が150〜180°Cと比較的高く、強靭で硬質塩化ビニル樹脂同等の硬度を持つ等、優れた機械的特性を有し、さらには透明性も有していることから、様々な分野において用いられている。   In recent years, from the viewpoint of environmental protection, biodegradable resins that can be decomposed by microorganisms or the like in the natural environment have attracted attention. Specific examples of such biodegradable resins include biodegradable resins that can be melt-molded, such as polylactic acid, polycaprolactone, polybutylene succinate, and polyethylene succinate. Among them, polylactic acid has a relatively high melting point of 150 to 180 ° C., and has excellent mechanical properties such as toughness and hardness equivalent to hard vinyl chloride resin, and also has transparency. Therefore, it is used in various fields.

しかし、ポリ乳酸は剛直であり、強度は高いが機械的な伸びや柔軟性に劣り、耐衝撃性が他の生分解性樹脂に比べて低いという問題点を有している。このため、ポリ乳酸と他の軟質生分解性樹脂とを混合することが行われている。例えば、特許文献1には、ポリ乳酸と脂肪族ポリエステルとポリカプロラクトンとを所定の割合で混合されたポリ乳酸樹脂組成物が提案されており、柔軟性や耐衝撃性を向上させることができる旨記載されている。しかし、このポリ乳酸樹脂組成物は、単に樹脂どうしを加熱溶融して機械的に混合しただけであるため、相溶性や分散性に劣るものであり、相分離を起こして充分な効果が得られない。   However, polylactic acid is rigid, has high strength but is inferior in mechanical elongation and flexibility, and has a problem that impact resistance is lower than other biodegradable resins. For this reason, mixing of polylactic acid and other soft biodegradable resin is performed. For example, Patent Document 1 proposes a polylactic acid resin composition in which polylactic acid, aliphatic polyester, and polycaprolactone are mixed at a predetermined ratio, and can improve flexibility and impact resistance. Are listed. However, since this polylactic acid resin composition is merely obtained by heating and melting the resins and mechanically mixing them, it is inferior in compatibility and dispersibility, and sufficient effects can be obtained by causing phase separation. Absent.

こうした問題点を解決するため、発明者らは、ポリ乳酸とポリカプロラクトンとを多官能イソシアナート化合物である2−イソシアナートエチル−2 ,6−ジイソシアナートカプロエート(以下LTIという)によって架橋したポリ乳酸樹脂組成物を既に開発している(特許文献2)。このポリ乳酸樹脂組成物は、ポリ乳酸とポリカプロラクトンとがLTIによって化学結合で架橋されているため、単に樹脂どうしを加熱溶融して機械的に混合した場合に比べて、相溶性や分散性に優れており、耐衝撃性も優れたものとなっている。   In order to solve such problems, the inventors cross-linked polylactic acid and polycaprolactone with 2-isocyanate ethyl-2,6-diisocyanatocaproate (hereinafter referred to as LTI), which is a polyfunctional isocyanate compound. A developed polylactic acid resin composition has already been developed (Patent Document 2). In this polylactic acid resin composition, polylactic acid and polycaprolactone are cross-linked by a chemical bond by LTI, so that the compatibility and dispersibility are higher than when the resins are simply heated and melted and mechanically mixed. It has excellent impact resistance.

特開2001−31853号公報JP 2001-31853 A 特開2004−346241号公報JP 2004-346241 A

しかし、上記ポリ乳酸とポリカプロラクトンとをLTIによって架橋したポリ乳酸樹脂組成物では、加熱溶融した場合の剪断粘度が大きいために、金型内での流れが悪く、成形品に引けや歪が生じたり、充填不足となったりするという問題があった。また、耐衝撃性のさらなる向上も望まれていた。
本発明は、上記従来の問題点に鑑みなされたものであり、加熱溶融した場合の剪断粘度が低くて成形品に引けや歪が生じ難く、相溶性、分散性、柔軟性及び耐衝撃性に優れたポリ乳酸系樹脂組成物及びその製造方法を提供することを課題とする。
However, in the polylactic acid resin composition in which the above polylactic acid and polycaprolactone are cross-linked by LTI, since the shear viscosity when heated and melted is large, the flow in the mold is poor, and the molded product is attracted or distorted. Or there was a problem of insufficient filling. Further, further improvement in impact resistance has been desired.
The present invention has been made in view of the above-mentioned conventional problems, and the shear viscosity when heated and melted is low, and the molded product is hardly attracted or distorted, and has compatibility, dispersibility, flexibility and impact resistance. It is an object of the present invention to provide an excellent polylactic acid resin composition and a method for producing the same.

発明者らは、ポリ乳酸の軟化剤としてポリカプロラクトンの代わりにポリブチレンサクシネートを用い、多官能イソシアナート化合物としてイソシアヌレート型ポリイソシアナートを用いて架橋させれば、耐衝撃性及び流動性が大幅に向上することを見出し、本発明を完成するにいたった。   When the inventors use polybutylene succinate instead of polycaprolactone as a softening agent for polylactic acid and crosslink using isocyanurate type polyisocyanate as a polyfunctional isocyanate compound, impact resistance and fluidity can be obtained. It has been found that it is greatly improved, and the present invention has been completed.

すなわち、本発明のポリ乳酸樹脂組成物は、ポリ乳酸とポリブチレンサクシネートとがイソシアヌレート型ポリイソシアナートによって架橋されていることを特徴とする。   That is, the polylactic acid resin composition of the present invention is characterized in that polylactic acid and polybutylene succinate are cross-linked by isocyanurate type polyisocyanate.

本発明のポリ乳酸樹脂組成物は、ポリ乳酸とポリブチレンサクシネートとがイソシアヌレート型ポリイソシアナートによって架橋されているため、単に樹脂どうしを加熱溶融して機械的に混合した場合に比べて、相溶性や分散性に優れ、耐衝撃性も優れたものとなっている。また、ポリ乳酸及びポリブチレンサクシネートは、ともに生分解性樹脂であるため、埋立処分されても微生物によって分解され、環境問題を引き起こすおそれが少ない。
また、発明者らの試験結果によれば、ポリ乳酸とポリカプロラクトンとをLTIによって架橋したポリ乳酸樹脂組成物と比較して、溶融状態での剪断粘度が低く、成形品に引けや歪が生じ難いという性質を有している。また、耐衝撃性も大幅に上回るものであった。
In the polylactic acid resin composition of the present invention, since polylactic acid and polybutylene succinate are crosslinked by isocyanurate type polyisocyanate, compared to a case where the resins are simply heated and melted and mechanically mixed, It has excellent compatibility and dispersibility, and has excellent impact resistance. In addition, since polylactic acid and polybutylene succinate are both biodegradable resins, they are less likely to be degraded by microorganisms and cause environmental problems even when landfilled.
Further, according to the test results of the inventors, compared with a polylactic acid resin composition obtained by cross-linking polylactic acid and polycaprolactone by LTI, the shear viscosity in the molten state is low, and the molded product is attracted or distorted. It has the property of being difficult. Moreover, the impact resistance was significantly higher.

ここで、イソシアヌレート型ポリイソシアナートとは、ジイソシアナート化合物の末端のイソシアナート基が3つ結合して6員環の基本骨格(下記構造式化1参照)を備えたジイソシアナート化合物の多量体である。

Figure 2008222883
例えば、ヘキサメチレンジイソシアナートを構成単位とするイソシアヌレート型ポリイソシアナートを例に挙げれば、下記構造式化2で示される。
Figure 2008222883
ただし、下記構造式化3に示される分岐した構造を有するものも、イソシアヌレート型ポリイソシアナートに含まれる。
Figure 2008222883
Here, the isocyanurate-type polyisocyanate is a diisocyanate compound having a six-membered basic skeleton (see the following structural formula 1) in which three isocyanate groups at the end of the diisocyanate compound are bonded. It is a multimer.
Figure 2008222883
For example, an isocyanurate type polyisocyanate having hexamethylene diisocyanate as a structural unit is shown as an example in the following structural formula 2.
Figure 2008222883
However, those having a branched structure represented by the following structural formula 3 are also included in the isocyanurate type polyisocyanate.
Figure 2008222883

また、ヘキサメチレン鎖の替わりに、炭素鎖の長さの異なる他の脂肪族ジイソシアネートを用いても、イソシアヌレート型ポリイソシアナートとすることができる。   Further, an isocyanurate-type polyisocyanate can be obtained by using another aliphatic diisocyanate having a different carbon chain length instead of the hexamethylene chain.

ポリ乳酸とポリブチレンサクシネートとの割合は95:5〜20:80(重量比)であることが好ましい。ポリ乳酸が95重量%より多いと耐衝撃性の改善が困難になり、反対に20重量% より少ないとポリ乳酸の特徴である高剛性が損なわれる。特に好ましいのは85:15〜70:30 の範囲である。   The ratio of polylactic acid to polybutylene succinate is preferably 95: 5 to 20:80 (weight ratio). If the polylactic acid is more than 95% by weight, it is difficult to improve the impact resistance. Conversely, if the polylactic acid is less than 20% by weight, the high rigidity characteristic of polylactic acid is impaired. Particularly preferred is the range of 85:15 to 70:30.

イソシアヌレート型ポリイソシアナートは、ポリ乳酸とポリブチレンサクシネートの合計に対して0.1〜2.0重量% 含まれていることが好ましい。イソシアヌレート型ポリイソシアナートの添加量が0.1重量% 未満であると、イソシアヌレート型ポリイソシアナートによる架橋効果が不十分となり、耐衝撃性及び可撓性の向上の効果を十分に得られない。また、イソシアヌレート型ポリイソシアナートの添加量が2.0重量%を超えると、過剰のイソシアナート基が分子間の架橋を惹起してゲル化分率の増加を招き、押出及び射出成形の加工性が悪くなる。   The isocyanurate type polyisocyanate is preferably contained in an amount of 0.1 to 2.0% by weight based on the total of polylactic acid and polybutylene succinate. If the addition amount of the isocyanurate type polyisocyanate is less than 0.1% by weight, the crosslinking effect by the isocyanurate type polyisocyanate becomes insufficient, and the effect of improving impact resistance and flexibility can be sufficiently obtained. Absent. If the amount of the isocyanurate-type polyisocyanate added exceeds 2.0% by weight, excess isocyanate groups cause cross-linking between molecules, leading to an increase in the gelation fraction, and processing of extrusion and injection molding. Sexuality gets worse.

本発明に用いるポリ乳酸の分子量としては、重量平均分子量が50,000〜1000,000の範囲のものが好ましい。かかる範囲を下回るものでは機械的強度が弱くなり、それ以上の分子量のものは、加工性の劣るものとなってしまうためである。   The polylactic acid used in the present invention preferably has a weight average molecular weight in the range of 50,000 to 1,000,000. If the thickness is below this range, the mechanical strength is weakened, and if the molecular weight is higher than that, the processability is inferior.

ポリ乳酸は、使用者が自ら合成してもよいが、入手のし易さから市販されているものを用いることも可能である。具体的には、Cargill−DOW社製のNature Works(登録商標)、トヨタ自動車(株)製のU’z(登録商標)、UCC社製のTONE(登録商標)、島津製作所(株)製のラクティ(登録商標)、ユニチカ( 株)製のテラマック(登録商標)、三井化学(株)製のレイシア(登録商標)、カネボウ合繊社製ラクトロン(登録商標)、三菱樹脂社製のエコロージュ(登録商標)、クラレ(株)社製のプラスターチ(登録商標)、東セロ(株)社製のパルグリーン(登録商標)等が挙げられる。
ポリ乳酸の中でも、両末端に水酸基、両末端にカルボン酸基、あるいは両末端に水酸基とカルボン酸基を有するテレケリック型のものが特に好ましい。こうしたポリ乳酸であれば、添加剤として用いる多官能イソシアナート化合物と反応して、より多くの架橋構造を形成されるため、機械強度が高くなり、優れたポリ乳酸系樹脂組成物となるからである。
The polylactic acid may be synthesized by the user himself, but it is also possible to use a commercially available product because it is easily available. Specifically, Nature Works (registered trademark) manufactured by Cargill-DOW, U'z (registered trademark) manufactured by Toyota Motor Corporation, TONE (registered trademark) manufactured by UCC, manufactured by Shimadzu Corporation Lacty (registered trademark), Terramac (registered trademark) manufactured by Unitika Ltd., Lacia (registered trademark) manufactured by Mitsui Chemicals, Inc., Lactron (registered trademark) manufactured by Kanebo Gosei Co., Ltd. ), Plastarch (registered trademark) manufactured by Kuraray Co., Ltd., Palgreen (registered trademark) manufactured by Tosero Co., Ltd., and the like.
Among the polylactic acids, telechelic types having a hydroxyl group at both ends and a carboxylic acid group at both ends, or a hydroxyl group and a carboxylic acid group at both ends are particularly preferred. With such polylactic acid, it reacts with the polyfunctional isocyanate compound used as an additive to form more cross-linked structures, resulting in higher mechanical strength and an excellent polylactic acid resin composition. is there.

また、ポリ乳酸とは、実質的にL−乳酸及び/又はD−乳酸がエステル結合で重合している高分子をいう。ここで「実質的」にとは、本発明の効果を損なわない程度範囲で、L−乳酸またはD−乳酸以外の他のモノマー単位を含んでいても良いという意味である。   Polylactic acid refers to a polymer in which L-lactic acid and / or D-lactic acid is polymerized by an ester bond. Here, "substantially" means that other monomer units other than L-lactic acid or D-lactic acid may be included within a range not impairing the effects of the present invention.

ポリ乳酸とポリブチレンサクシネートとをイソシアヌレート型ポリイソシアナートによって架橋する方法については特に限定されるものではないが、工業的には連続的に処理できる方法が好ましい。具体的には、例えば、上記の成分を所定の割合で混合したものを一軸スクリュー押出機や二軸混練押出機などで混練し、直ちに成形して成形品とすることができる。また、上記の成分を所定の割合で量り取り、溶剤によって均一に溶解してから溶媒を留去させてもよいが、多官能イソシアナート化合物には水分等との反応性の高いイソシアナート基を含有するため、水分を含まない溶媒を用いる必要がある。
押出機を用いる場合、押出溶融温度は160〜230°Cの範囲が好ましく、さらに好ましいのは180〜220°Cである。ポリマーの劣化、変質等を防ぐことが必要なために、反応時間としてはできるだけ短時間内に混合することが好ましい。具体的には時間は20分以内、さらに好ましくは10分以内で混合することが好ましい。
The method for crosslinking polylactic acid and polybutylene succinate with an isocyanurate type polyisocyanate is not particularly limited, but industrially preferred is a method capable of being continuously treated. Specifically, for example, a mixture obtained by mixing the above components at a predetermined ratio can be kneaded with a single screw extruder or a twin screw kneading extruder and immediately molded into a molded product. In addition, the above components may be weighed out at a predetermined ratio and uniformly dissolved with a solvent, and then the solvent may be distilled off. However, the polyfunctional isocyanate compound has an isocyanate group that is highly reactive with moisture and the like. Since it contains, it is necessary to use the solvent which does not contain moisture.
In the case of using an extruder, the extrusion melting temperature is preferably in the range of 160 to 230 ° C, more preferably 180 to 220 ° C. Since it is necessary to prevent deterioration and alteration of the polymer, the reaction time is preferably mixed within a short time as possible. Specifically, it is preferable to mix within 20 minutes, more preferably within 10 minutes.

また、イソシアヌレート型ポリイソシアナートは、ポリ乳酸とポリブチレンサクシネートとを加熱溶融混合した後に添加し、再度加熱溶融混合してもよいし、全ての成分を同時に加熱溶融混合してもよい。   The isocyanurate-type polyisocyanate may be added after heat-melt mixing of polylactic acid and polybutylene succinate, and may be heat-melt-mixed again, or all components may be heat-melt-mixed simultaneously.

本発明のポリ乳酸樹脂組成物には、発明の課題達成を阻害しない範囲で必要に応じて副次的な添加物を加えて様々な改質を行うことが可能である。副次的な添加物の例としては、酸化防止剤、難燃剤、紫外線吸収剤、着色剤、顔料、抗菌剤、安定剤、静電剤、核形成材、各種フィラー等その他の類似のものが挙げられる。   The polylactic acid resin composition of the present invention can be subjected to various modifications by adding secondary additives as necessary within a range that does not hinder achievement of the problems of the invention. Examples of secondary additives include antioxidants, flame retardants, UV absorbers, colorants, pigments, antibacterial agents, stabilizers, electrostatic agents, nucleating materials, other fillers and other similar ones. Can be mentioned.

以下、本発明をさらに具体化した実施例について比較例と比較しつつ説明する。
(実施例1)
実施例1では、ヘキサメチレンジイソシアネートを構成単位とするイソシアヌレート型ポリイソシアナートを架橋剤として用い、この架橋剤によってポリ乳酸とポリブチレンサクシネート(PBS)とを架橋した。製造方法の詳細を以下に示す。
Examples in which the present invention is further embodied will be described below in comparison with comparative examples.
(Example 1)
In Example 1, isocyanurate type polyisocyanate having hexamethylene diisocyanate as a structural unit was used as a crosslinking agent, and polylactic acid and polybutylene succinate (PBS) were crosslinked by this crosslinking agent. Details of the manufacturing method are shown below.

ポリ乳酸(ユニチカ社製テラマックT−4000)を100°Cで4時間乾燥する。また、ポリブチレンサクシネート(昭和高分子社製 ビオノーレ#1020)を80°Cで4時間乾燥する。こうして十分に水分率を減少させた後、ポリ乳酸とポリブチレンサクシネート(PBS)とを90:10の重量割合で混合し、さらに、ヘキサメチレンジイソシアナートを構成単位とするイソシアヌレート型ポリイソシアナート(旭化成ケミカルズ株式会社製 デュラネートTSA−100)をポリ乳酸とポリブチレンサクシネート(PBS)の合計に対して0.5重量%加えて混合する。この混合物を190°Cで二軸の押出加熱混練機で溶融押出し、ペレット化して主原料を準備した。得られたペレットを4時間乾燥した後、射出成形することにより、衝撃試験用の試験片(80×10×4mm)を作製した。   Polylactic acid (Teramac T-4000 manufactured by Unitika Ltd.) is dried at 100 ° C. for 4 hours. Further, polybutylene succinate (Bionore # 1020 manufactured by Showa Polymer Co., Ltd.) is dried at 80 ° C. for 4 hours. After sufficiently reducing the moisture content in this way, polylactic acid and polybutylene succinate (PBS) are mixed at a weight ratio of 90:10, and isocyanurate type polyisocyanate having hexamethylene diisocyanate as a structural unit. Nart (Duranate TSA-100, manufactured by Asahi Kasei Chemicals Co., Ltd.) is added to and mixed with 0.5% by weight based on the total of polylactic acid and polybutylene succinate (PBS). This mixture was melt-extruded at 190 ° C. with a biaxial extrusion heating kneader and pelletized to prepare a main raw material. The obtained pellets were dried for 4 hours and then injection-molded to produce a test piece (80 × 10 × 4 mm) for impact test.

(実施例2)
実施例2では、ポリ乳酸とポリブチレンサクシネート(PBS)とを80:20の重量割合で混合した。他の条件は実施例1と同様であり説明を省略する。
(Example 2)
In Example 2, polylactic acid and polybutylene succinate (PBS) were mixed at a weight ratio of 80:20. Other conditions are the same as those in the first embodiment, and a description thereof will be omitted.

(実施例3)
実施例3では、ヘキサメチレンジイソシアナートを構成単位とするイソシアヌレート型ポリイソシアナートとして、旭化成ケミカルズ株式会社製のデュラネートTPA−100を用いた。他の条件は実施例2と同様であり説明を省略する。
(Example 3)
In Example 3, Duranate TPA-100 manufactured by Asahi Kasei Chemicals Corporation was used as an isocyanurate type polyisocyanate having hexamethylene diisocyanate as a structural unit. Other conditions are the same as those in the second embodiment, and a description thereof will be omitted.

(実施例4)
実施例4では、ヘキサメチレンジイソシアナートを構成単位とするイソシアヌレート型ポリイソシアナートとして、旭化成ケミカルズ株式会社製のデュラネートTPA−100をポリ乳酸とポリブチレンサクシネート(PBS)の合計に対して0.15重量%加えた。他の条件は実施例1と同様であり説明を省略する。
Example 4
In Example 4, as an isocyanurate-type polyisocyanate having hexamethylene diisocyanate as a structural unit, Duranate TPA-100 manufactured by Asahi Kasei Chemicals Co., Ltd. was reduced to 0 with respect to the total of polylactic acid and polybutylene succinate (PBS). 15% by weight was added. Other conditions are the same as those in the first embodiment, and a description thereof will be omitted.

(比較例1)
比較例1では、架橋剤として2−イソシアナートエチル−2 ,6−ジイソシアナートカプロエート(LTI)を用い、この架橋剤によってポリ乳酸とポリカプロラクトン(PCL)とを架橋した。製造方法の詳細を以下に示す。
ポリ乳酸(ユニチカ社製テラマックT−4000)を100°Cで4時間乾燥する。また、ポリカプロラクトン(ダイセル化学工業 セルグリーンPH7)を50°Cで24時間乾燥する。こうして十分に水分率を減少させた後、ポリ乳酸とポリカプロラクトンとを80:20の重量割合で混合し、さらに、LTIをポリ乳酸とポリカプロラクトンの合計に対して0.5重量%加えて混合する。この混合物を実施例1と同様の方法により、二軸の押出混練機で溶融押出し、ペレット化して主原料を準備した。得られたペレットを4時間乾燥した後、射出成形することにより、衝撃試験用の試験片を作製した。
(Comparative Example 1)
In Comparative Example 1, 2-isocyanatoethyl-2,6-diisocyanatocaproate (LTI) was used as a crosslinking agent, and polylactic acid and polycaprolactone (PCL) were crosslinked with this crosslinking agent. Details of the manufacturing method are shown below.
Polylactic acid (Teramac T-4000 manufactured by Unitika Ltd.) is dried at 100 ° C. for 4 hours. Also, polycaprolactone (Daicel Chemical Industries Cell Green PH7) is dried at 50 ° C. for 24 hours. After sufficiently reducing the moisture content in this way, polylactic acid and polycaprolactone are mixed at a weight ratio of 80:20, and further LTI is added by 0.5% by weight with respect to the total of polylactic acid and polycaprolactone and mixed. To do. This mixture was melt-extruded by a biaxial extrusion kneader in the same manner as in Example 1 and pelletized to prepare a main raw material. The obtained pellets were dried for 4 hours and then injection-molded to produce a test piece for impact test.

(比較例2)
比較例2では、架橋剤としてヘキサメチレンジイソシアネートを構成単位とするアダクト型ポリイソシアナート(旭化成ケミカルズ株式会社製のデュラネートE−402−90T)(下記構造式化4)を用いた。他の条件は実施例2と同様であり説明を省略する。

Figure 2008222883
(Comparative Example 2)
In Comparative Example 2, an adduct polyisocyanate (Duranate E-402-90T manufactured by Asahi Kasei Chemicals Corporation) (structural formula 4 below) having hexamethylene diisocyanate as a structural unit was used as a crosslinking agent. Other conditions are the same as those in the second embodiment, and a description thereof will be omitted.
Figure 2008222883

(比較例3)
比較例3では、架橋剤としてヘキサメチレンジイソシアネートを構成単位とするビウレット型ポリイソシアナート(旭化成ケミカルズ株式会社製のデュラネート24A100)(下記構造式化5)を用いた。他の条件は比較例1と同様であり説明を省略する。

Figure 2008222883
(Comparative Example 3)
In Comparative Example 3, biuret type polyisocyanate (Duranate 24A100 manufactured by Asahi Kasei Chemicals Corporation) (structural formula 5 below) having hexamethylene diisocyanate as a structural unit was used as a crosslinking agent. Other conditions are the same as those in Comparative Example 1, and a description thereof is omitted.
Figure 2008222883

(比較例4)
比較例4では、架橋剤として3つのエポキシ基を有する化合物(大日本インキ化学工業株式会社製 Epiclon725)を用いた。他の条件は比較例1と同様であり説明を省略する。
(Comparative Example 4)
In Comparative Example 4, a compound having three epoxy groups (Epiclon 725 manufactured by Dainippon Ink & Chemicals, Inc.) was used as a crosslinking agent. Other conditions are the same as those in Comparative Example 1, and a description thereof is omitted.

(比較例5)
比較例5では、ポリ乳酸とポリカプロラクトンとを90:10の重量比とした。また、架橋剤としてLTIをポリ乳酸とポリカプロラクトン(PCL)の合計に対して0.15重量%加えた。他の条件は比較例1と同様であり説明を省略する。
(Comparative Example 5)
In Comparative Example 5, polylactic acid and polycaprolactone were in a weight ratio of 90:10. Further, LTI was added as a crosslinking agent in an amount of 0.15% by weight based on the total of polylactic acid and polycaprolactone (PCL). Other conditions are the same as those in Comparative Example 1, and a description thereof is omitted.

(比較例6)
比較例6では、架橋剤としてLTIをポリ乳酸とポリブチレンサクシネートの合計に対して0.5重量%加えた。他の条件は実施例1と同様であり説明を省略する。
(Comparative Example 6)
In Comparative Example 6, 0.5% by weight of LTI was added as a crosslinking agent with respect to the total of polylactic acid and polybutylene succinate. Other conditions are the same as those in the first embodiment, and a description thereof will be omitted.

(比較例7)
比較例7では、ポリ乳酸とポリカプロラクトンとを80:20の重量比とした。他は他の条件は実施例3と同様であり説明を省略する。
(Comparative Example 7)
In Comparative Example 7, the weight ratio of polylactic acid and polycaprolactone was 80:20. Other conditions are the same as those in the third embodiment, and a description thereof will be omitted.

こうして得られた実施例1〜4及び比較例1〜6のポリ乳酸樹脂組成物の組成割合を表1に示す。

Figure 2008222883
Table 1 shows the composition ratios of the polylactic acid resin compositions of Examples 1 to 4 and Comparative Examples 1 to 6 thus obtained.
Figure 2008222883

<評 価>
以上のようにして得られた実施例1〜4及び比較例1〜7の試験片について、シャルピー衝撃試験及び剪断速度−剪断粘度の測定を行った。シャルピー衝撃試験は、JIS−K7111に準じてエッジワイズ、ノッチ無し試験片で測定した。また、剪断速度−剪断粘度は、キャピラリーレオメーター(ROSAND社製 RH−7)を用い、220°Cにおいて測定した。キャピラリーレオメーターはキャピラリー(直径1mmの細管)を通過させるときの樹脂の粘度を測定する装置である。類似の装置としてはメルトフローレート(MFR)があるが、キャピラリーレオメーターデータは金型内流動のコンピューターシュミレーションに用いられ、金型内での流れ特性が良く反映されている。また、メルトフローレートについても、メルトフロー試験機(井元製作所製 MB−1)によって測定を行った。
<Evaluation>
The test pieces of Examples 1 to 4 and Comparative Examples 1 to 7 obtained as described above were subjected to Charpy impact test and shear rate-shear viscosity measurement. The Charpy impact test was measured with an edgewise and notched test piece according to JIS-K7111. The shear rate-shear viscosity was measured at 220 ° C. using a capillary rheometer (RH-7, manufactured by Rosand). A capillary rheometer is a device that measures the viscosity of a resin when passing through a capillary (a capillary having a diameter of 1 mm). There is a melt flow rate (MFR) as a similar device, but capillary rheometer data is used for computer simulation of flow in the mold, and the flow characteristics in the mold are well reflected. The melt flow rate was also measured by a melt flow tester (MB-1 manufactured by Imoto Seisakusho).

−シャルピー衝撃試験−
シャルピー衝撃試験の結果を図1に示す。この図から、イソシアヌレート型ポリイソシアナートを架橋剤として用いた実施例1〜4のポリ乳酸樹脂組成物は、それ以外の架橋剤を用いた比較例1〜6のポリ乳酸樹脂組成物と比べて衝撃値が大きいことが分かる。また、実施例4と比較例1〜7との比較から明らかなように、架橋剤の添加量が0.15重量%と少ないにもかかわらず、実施例4では比較例1〜7より衝撃値が大きいことが分かる。さらに、架橋剤としてイソシアヌレート型ポリイソシアナートを用いた場合であっても、ポリ乳酸にポリブチレンサクシネートを混合した実施例2〜3では、ポリ乳酸にポリカプロラクトンを混合した比較例7より衝撃値が大きいことが分かった。また、架橋剤としてLTIを用い、ポリ乳酸とポリカプロラクトンとを混合した比較例1(すなわち特許文献2に記載されているポリ乳酸樹脂組成物)よりも、イソシアヌレート型ポリイソシアナート(TSA)を架橋剤とし、ポリ乳酸とポリブチレンサクシネートを混合した実施例2、3の方が衝撃値が大きいことが分かる。さらに、実施例1と比較例1との比較から、イソシアヌレート型ポリイソシアナート(TSA)を架橋剤とした場合、ポリ乳酸とポリブチレンサクシネートを混合した方が、ポリ乳酸とポリカプロラクトンとを混合した場合よりも衝撃値が大きくなることが分かる。
-Charpy impact test-
The result of the Charpy impact test is shown in FIG. From this figure, the polylactic acid resin compositions of Examples 1 to 4 using isocyanurate type polyisocyanate as a crosslinking agent are compared with the polylactic acid resin compositions of Comparative Examples 1 to 6 using other crosslinking agents. It can be seen that the impact value is large. Further, as is clear from the comparison between Example 4 and Comparative Examples 1 to 7, the impact value of Example 4 is higher than that of Comparative Examples 1 to 7 in Example 4 even though the addition amount of the crosslinking agent is as small as 0.15 wt%. Can be seen to be large. Further, even when an isocyanurate type polyisocyanate was used as a cross-linking agent, in Examples 2 to 3 in which polybutylene succinate was mixed with polylactic acid, the impact was greater than that in Comparative Example 7 in which polycaprolactone was mixed with polylactic acid. The value was found to be large. Further, isocyanurate type polyisocyanate (TSA) is used rather than Comparative Example 1 (ie, polylactic acid resin composition described in Patent Document 2) in which LTI is used as a crosslinking agent and polylactic acid and polycaprolactone are mixed. It can be seen that the impact value is larger in Examples 2 and 3 in which polylactic acid and polybutylene succinate are mixed as a crosslinking agent. Further, from comparison between Example 1 and Comparative Example 1, when isocyanurate type polyisocyanate (TSA) was used as a crosslinking agent, polylactic acid and polybutylene succinate were mixed with polylactic acid and polycaprolactone. It can be seen that the impact value is larger than that in the case of mixing.

−キャピラリーレオメーターによる剪断粘度測定−
結果を図2に示す。この図から、イソシアヌレート型ポリイソシアナートを架橋剤として用いた実施例1及び実施例2の剪断粘度は、LTIを架橋剤とした比較例1の剪断粘度よりも低くなっていることが分かる。このため、実施例1及び実施例2のポリ乳酸樹脂組成物は、金型内での流れがスムースとなり、引けや歪が生じ難いことが分かった。
-Shear viscosity measurement with capillary rheometer-
The results are shown in FIG. From this figure, it can be seen that the shear viscosity of Example 1 and Example 2 using isocyanurate type polyisocyanate as a crosslinking agent is lower than that of Comparative Example 1 using LTI as a crosslinking agent. For this reason, in the polylactic acid resin composition of Example 1 and Example 2, it turned out that the flow in a metal mold | die becomes smooth, and it is hard to produce a shrinkage | contraction and distortion.

−メルトフローレート測定−
実施例1及び比較例1について、メルトフローレートを測定した結果、実施例1では10.42g/10minであったのに対し、比較例1では3g/10minであり、実施例1の1/3以下であった。この結果からも、実施例1のポリ乳酸樹脂組成物は、金型内での流れがスムースとなり、引けや歪が生じ難いことが分かる。
-Melt flow rate measurement-
As a result of measuring the melt flow rate for Example 1 and Comparative Example 1, it was 10.42 g / 10 min in Example 1, but 3 g / 10 min in Comparative Example 1, which was 1/3 of Example 1. It was the following. Also from this result, it can be seen that in the polylactic acid resin composition of Example 1, the flow in the mold is smooth, and it is difficult for shrinkage and distortion to occur.

以上のように、実施例1〜4のポリ乳酸樹脂組成物は、ポリ乳酸とポリブチレンサクシネート(PBS)とがイソシアヌレート型ポリイソシアナートによって架橋されているため、LTIのようなトリイソシアネートやビュレット型ポリイソシアネートやアダクト型によって架橋した場合と比べても、耐衝撃性が飛躍的に大きくなった。また、架橋剤の添加量が0.15重量%と少ない場合でも、耐衝撃性を高めることができる。さらに、単に樹脂どうしを加熱溶融して機械的に混合した場合に比べて、相溶性や分散性に優れている。また、加熱溶融した場合の剪断粘度が低くて成形品に引けや歪が生じ難い。さらには、ポリ乳酸及びポリブチレンサクシネート(PBS)は、ともに生分解性樹脂であるため、埋立処分されても微生物によって分解され、環境問題を引き起こすおそれが少ない。   As described above, in the polylactic acid resin compositions of Examples 1 to 4, since polylactic acid and polybutylene succinate (PBS) are cross-linked by isocyanurate type polyisocyanate, triisocyanate such as LTI Compared to the case of crosslinking with a burette type polyisocyanate or an adduct type, the impact resistance has been dramatically increased. Moreover, even when the addition amount of the crosslinking agent is as small as 0.15% by weight, the impact resistance can be improved. Furthermore, it is superior in compatibility and dispersibility as compared with the case where the resins are simply melted by heating and mechanically mixed. In addition, since the shear viscosity is low when melted by heating, the molded product is unlikely to shrink or distort. Furthermore, since both polylactic acid and polybutylene succinate (PBS) are biodegradable resins, they are less likely to be degraded by microorganisms and cause environmental problems even when disposed of in landfills.

この発明は、上記発明の実施例の説明に何ら限定されるものではない。特許請求の範囲の記載を逸脱せず、当業者が容易に想到できる範囲で種々の変形態様もこの発明に含まれる。   The present invention is not limited to the description of the embodiments of the invention. Various modifications may be included in the present invention as long as those skilled in the art can easily conceive without departing from the description of the scope of claims.

本発明のポリ乳酸系樹脂組成物は、包装材料、医療用材料、産業資材、工業用品、容器等の各種用途に使用することができる。具体的には、フィルム、シート、被覆紙、ブロー成形体、射出成形体、押出成形体、繊維、不織布、包装材等に利用できる。   The polylactic acid-based resin composition of the present invention can be used for various uses such as packaging materials, medical materials, industrial materials, industrial products, containers and the like. Specifically, it can be used for films, sheets, coated papers, blow molded articles, injection molded articles, extruded molded articles, fibers, nonwoven fabrics, packaging materials, and the like.

シャルピー衝撃試験における衝撃値を示すグラフである。It is a graph which shows the impact value in a Charpy impact test. 剪断速度と剪断粘度との関係を示すグラフである。It is a graph which shows the relationship between a shear rate and shear viscosity.

Claims (6)

ポリ乳酸とポリブチレンサクシネートとがイソシアヌレート型ポリイソシアナートによって架橋されていることを特徴とするポリ乳酸樹脂組成物。   A polylactic acid resin composition characterized in that polylactic acid and polybutylene succinate are crosslinked by an isocyanurate type polyisocyanate. イソシアヌレート型ポリイソシアナートはヘキサメチレンジイソシアナートを構成単位とすることを特徴とする請求項1記載のポリ乳酸樹脂組成物。   The polylactic acid resin composition according to claim 1, wherein the isocyanurate type polyisocyanate comprises hexamethylene diisocyanate as a structural unit. ポリ乳酸とポリブチレンサクシネートとの割合は95:5〜20:80(重量比)であることを特徴とする請求項1又は2記載のポリ乳酸樹脂組成物。   The polylactic acid resin composition according to claim 1 or 2, wherein the ratio of polylactic acid to polybutylene succinate is 95: 5 to 20:80 (weight ratio). イソシアヌレート型ポリイソシアナートは、ポリ乳酸とポリブチレンサクシネートの合計に対して0.1〜2.0重量%含まれていることを特徴とする請求項1乃至3のいずれか1項記載のポリ乳酸樹脂組成物。   The isocyanurate type polyisocyanate is contained in an amount of 0.1 to 2.0% by weight based on the total amount of polylactic acid and polybutylene succinate. Polylactic acid resin composition. ポリ乳酸の分子量は、重量平均分子量が50,000〜1000,000の範囲であることを特徴とする請求項1乃至4のいずれか1項記載のポリ乳酸樹脂組成物。   The polylactic acid resin composition according to any one of claims 1 to 4, wherein the polylactic acid has a molecular weight in the range of 50,000 to 1,000,000 in weight average molecular weight. ポリ乳酸とポリブチレンサクシネートとをイソシアヌレート型ポリイソシアナートによって架橋することを特徴とするポリ乳酸樹脂組成物の製造方法。   A method for producing a polylactic acid resin composition, comprising cross-linking polylactic acid and polybutylene succinate with an isocyanurate type polyisocyanate.
JP2007064181A 2007-03-13 2007-03-13 Polylactic acid resin composition and method for producing the same Expired - Fee Related JP4977890B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2007064181A JP4977890B2 (en) 2007-03-13 2007-03-13 Polylactic acid resin composition and method for producing the same

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2007064181A JP4977890B2 (en) 2007-03-13 2007-03-13 Polylactic acid resin composition and method for producing the same

Publications (2)

Publication Number Publication Date
JP2008222883A true JP2008222883A (en) 2008-09-25
JP4977890B2 JP4977890B2 (en) 2012-07-18

Family

ID=39841873

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2007064181A Expired - Fee Related JP4977890B2 (en) 2007-03-13 2007-03-13 Polylactic acid resin composition and method for producing the same

Country Status (1)

Country Link
JP (1) JP4977890B2 (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2009063943A1 (en) * 2007-11-16 2009-05-22 Nec Corporation Shape memory resin, shaped article using the same and method of using the shaped article
WO2023032763A1 (en) * 2021-08-30 2023-03-09 旭化成株式会社 Biodegradable nonwoven fabric and use of same

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH1025439A (en) * 1996-07-12 1998-01-27 Toppan Printing Co Ltd Biodegradable magnetic ink composition
JPH10182781A (en) * 1996-12-19 1998-07-07 Basf Ag Polyurethane with covalently bonded photoinitiator unit, its production and use thereof
JPH11323104A (en) * 1998-05-19 1999-11-26 Shin Etsu Polymer Co Ltd Highly biodegradable pipe, joint and molding process thereof
JP2001106758A (en) * 1999-10-08 2001-04-17 Asahi Kasei Corp Urethane resin composition
JP2002173589A (en) * 2000-09-28 2002-06-21 Tohcello Co Ltd Aliphatic polyester composition, film made therefrom and laminate of the film
JP2004346241A (en) * 2003-05-23 2004-12-09 Nagoya City Polylactic acid resin composition and method for producing the same

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH1025439A (en) * 1996-07-12 1998-01-27 Toppan Printing Co Ltd Biodegradable magnetic ink composition
JPH10182781A (en) * 1996-12-19 1998-07-07 Basf Ag Polyurethane with covalently bonded photoinitiator unit, its production and use thereof
JPH11323104A (en) * 1998-05-19 1999-11-26 Shin Etsu Polymer Co Ltd Highly biodegradable pipe, joint and molding process thereof
JP2001106758A (en) * 1999-10-08 2001-04-17 Asahi Kasei Corp Urethane resin composition
JP2002173589A (en) * 2000-09-28 2002-06-21 Tohcello Co Ltd Aliphatic polyester composition, film made therefrom and laminate of the film
JP2004346241A (en) * 2003-05-23 2004-12-09 Nagoya City Polylactic acid resin composition and method for producing the same

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2009063943A1 (en) * 2007-11-16 2009-05-22 Nec Corporation Shape memory resin, shaped article using the same and method of using the shaped article
US8470935B2 (en) 2007-11-16 2013-06-25 Nec Corporation Shape-memory resin, molded product composed of the resin, and method of using the molded product
JP5651952B2 (en) * 2007-11-16 2015-01-14 日本電気株式会社 Shape memory resin, molded body using the same, and method of using the molded body
WO2023032763A1 (en) * 2021-08-30 2023-03-09 旭化成株式会社 Biodegradable nonwoven fabric and use of same

Also Published As

Publication number Publication date
JP4977890B2 (en) 2012-07-18

Similar Documents

Publication Publication Date Title
Chen et al. Bio-based PLA/NR-PMMA/NR ternary thermoplastic vulcanizates with balanced stiffness and toughness:“soft–hard” core–shell continuous rubber phase, in situ compatibilization, and properties
Wu et al. Super-tough poly (lactide) thermoplastic vulcanizates based on modified natural rubber
Esmaeili et al. Poly (lactic acid)/coplasticized thermoplastic starch blend: Effect of plasticizer migration on rheological and mechanical properties
JP4726887B2 (en) Natural fiber reinforced polylactic acid resin composition
US9228066B2 (en) Polymer material and method for the production thereof
CN108047658B (en) Biodegradable polyester agricultural mulching film
WO2006033229A1 (en) Resin composition and molding thereof
WO2007049529A1 (en) Polyester resin composition and molded body using same
JP2007063516A (en) Resin composition
JP2005298797A (en) Aliphatic polyester resin composition-molded item
JP4887860B2 (en) Polylactic acid resin composition for injection molding, method for producing the same, and injection molded body
JP4643154B2 (en) A thermoplastic resin composition and a molded body formed by molding the same.
TWI649370B (en) Alloy resin composition of polylactic acid/acrylonitrile-butadiene-styrene copolymer
JP2006259313A (en) Formed body for optical material
JP4977890B2 (en) Polylactic acid resin composition and method for producing the same
JP2009209226A (en) Polyester resin composition
JP4240373B2 (en) Polylactic acid resin composition and method for producing the same
JP2007023189A (en) Compatibilizing agent and resin composition
JPS6028446A (en) Thermoplastic polyester resin composition
EP0448749A1 (en) Thermoplastic blends containing ethylene terpolymers and the preparation thereof
KR101490951B1 (en) Polymer resin composition for automotive interior or exterior material, article for automotive interior or exterior and preparing method of the same
JP2008222865A (en) Biomass resin composition
JP2007039513A (en) Polybutylene succinate resin composition, its production method, molded article comprising the same
JP2006199788A (en) Stretched molding
KR20190035780A (en) Epoxy-modified vinyl copolymer, thermoplastic resin composition containing the same, and molded article thereof

Legal Events

Date Code Title Description
A621 Written request for application examination

Free format text: JAPANESE INTERMEDIATE CODE: A621

Effective date: 20090317

A977 Report on retrieval

Free format text: JAPANESE INTERMEDIATE CODE: A971007

Effective date: 20111031

A131 Notification of reasons for refusal

Free format text: JAPANESE INTERMEDIATE CODE: A131

Effective date: 20111115

RD04 Notification of resignation of power of attorney

Free format text: JAPANESE INTERMEDIATE CODE: A7424

Effective date: 20111229

A521 Written amendment

Free format text: JAPANESE INTERMEDIATE CODE: A523

Effective date: 20120207

TRDD Decision of grant or rejection written
A01 Written decision to grant a patent or to grant a registration (utility model)

Free format text: JAPANESE INTERMEDIATE CODE: A01

Effective date: 20120306

A01 Written decision to grant a patent or to grant a registration (utility model)

Free format text: JAPANESE INTERMEDIATE CODE: A01

A61 First payment of annual fees (during grant procedure)

Free format text: JAPANESE INTERMEDIATE CODE: A61

Effective date: 20120328

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20150427

Year of fee payment: 3

R150 Certificate of patent or registration of utility model

Free format text: JAPANESE INTERMEDIATE CODE: R150

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

LAPS Cancellation because of no payment of annual fees