JP2004189860A - Condensed thermoplastic resin composition and use thereof - Google Patents

Abstract

An object of the present invention is to provide a condensed thermoplastic resin molded article which suppresses deterioration due to hydrolysis of a condensed thermoplastic resin and has excellent mechanical properties and surface condition.
A condensed thermoplastic resin composition containing an aliphatic carbodiimide compound and a hindered amine compound, wherein the content of the aliphatic polycarbodiimide compound is 0.01 to 60% by weight and the content of the hindered amine compound is 0.01 to 60% by weight. A condensation type thermoplastic resin composition characterized by being 0.01 to 60% by weight, and a molded product obtained by using the same.
[Selection diagram] None

Description

【００３３】
表１中、「脂肪族ＰＣ−１」は水添ジフェニルメタンジイソシアネ−トを原料とした脂肪族系ポリカルボジイミド化合物であるジシクロヘキシルメタン−４，４−ポリカルボジイミド、
「脂肪族ＰＣ−２」はヘキサメチレンジイソシアネ−トを原料とする脂肪族系ポリカルボジイミド化合物であるヘキサメチレンポリカルボジイミド、
「脂肪族ＰＣ−３」はメチルヘキサメチレンジイソシアネ−トを原料とする脂肪族系ポリカルボジイミド化合物である３−メチルヘキサメチレンポリカルボジイミド、
「ＨＡＬＳ」はシ゛フ゛チルアミン・１，３，５−トリアシ゛ン・Ｎ，Ｎ−ヒ゛ス（２，２，６，６−テトラメチル−４−ヒ゜ヘ゜リシ゛ル−１，６−ヘキサメチメチレンシ゛アミン・Ｎ−（２，２，６，６−テトラメチル−４−ヒ゜ヘ゜リシ゛ル）フ゛チルアミンの重縮合物、
「ＰＥＴ」はポリエチレンテレフタレ−ト（固有粘度＝０．８３）、
「ＰＬＡ」はポリ乳酸（固有粘度＝１．９０）を用いた。
【００３４】
【表２】

【００３５】
表２中、表１と共通のものは表１の説明に準ずる。
「芳香族ＰＣ」はトルエンジイソシアネ−トを原料とした芳香族系ポリカルボジイミド（ラインケミ−社）、
「脂肪族ＭＣ」はジイソプロピルカルボジイミドを用いた。
【００３６】
［評価試験］
以上の実施例及び比較例で得られたコンパウンドとマスターバッチについて以下の評価を行い、結果を表３、４に示した。
ａ．加水分解性評価
実施例１〜１０、比較例１〜１２で得られたコンパウンドは、そのままの組成のものを以下のａ１で用いた。
また、実施例１１〜２０、比較例１３〜２４で得られたマスターバッチは、それぞれベース樹脂（各々成分（ウ）で用いた樹脂と同じ樹脂を用いた。）で１０倍希釈されるように混合した。その混合物をスクリュー直径３０ｍｍ、Ｌ／Ｄ値３０の単軸押出機に供給し、回転数１００ｒｐｍの条件でペレット化してコンパウンドを製造した。溶融混練の際の温度は、成分（ウ）がＰＥＴの場合は設定温度２８０℃、ＰＬＡの場合は設定温度２００℃で行った。
【００３７】
ａ１．固有粘度値
得られたコンパウンドを１４０℃で２時間乾燥後、１００ｍｌメスフラスコに０．５ｇ秤量し、フェノール：１，１，２，２−テトラクロロエタン＝１：１溶液１００ｍｌを正確に加えた。これを１５０℃で１．５時間攪拌溶解して測定サンプルとした。毛細管粘度自動測定装置（芝山科学株式会社「ＳＳ−６００−Ｌ２型」）を用いて固有粘度値を測定した。被成形樹脂のみ（成分（ウ）であるＰＥＴまたはＰＬＡ）の場合を１００％として、各コンパウンドの固有粘度値の保持率を求め、以下の基準に従い評価した。
○：固有粘度値の保持率９６％以上
△：固有粘度値の保持率９０％以上９６％未満
×：固有粘度値の保持率９０％未満
【００３８】
ａ２．機械物性保持率
実施例１〜１０、比較例１〜１２で得られたコンパウンドは、そのままの組成のものを射出成形機にて背圧１０ｋｇ／ｃｍ^２で射出成形し、プレ−トを得た。
また、実施例１１〜２０、比較例１３〜２４で得られたマスターバッチは、それぞれベース樹脂（各々成分（ウ）で用いた樹脂と同じ樹脂を用いた。）で１０倍希釈されるように混合した。その混合物を射出成形機にて背圧１０ｋｇ／ｃｍ^２で射出成形し、プレ−トを得た。
【００３９】
各プレ−トについて、引張強度試験（ＪＩＳ Ｋ７１１３）アイゾット衝撃試験（ＪＩＳ Ｋ７１１０）を行い、被成形樹脂のみからなるプレ−トの値を１００％としたときの各プレ−トの保持率をそれぞれ求め、以下の基準に従い評価した。
○：９６％以上
△：９０％以上９６％未満
×：９０％以下
【００４０】
ｂ．成形物表面状態評価
ａ２の機械物性保持率評価において作成した射出成形プレートの表面状態を電子顕微鏡及び目視により観察し、以下の基準に従い評価した。
○：表面が平滑であり、ゲル、ブツ等が見あたらない。
△：表面が平滑であるが、少数のブツが確認できる。
×：表面が凹凸であり、ゲル、ブツが多く確認できる。
【００４１】
【表３】

【００４２】
【表４】

【００４３】
【発明の効果】
本発明の縮合型熱可塑性樹脂組成物は、脂肪族ポリカルボジイミド化合物とヒンダードアミン系化合物を含有するので、実用性のある充分高い耐加水分解性及び耐熱性を有する。
従ってこれを用いて得られる縮合型熱可塑性樹脂成形品は、機械物性や表面状態が良好であるので従来以上に幅広い利用が可能である。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a condensation-type thermoplastic resin composition having excellent heat resistance and hydrolysis resistance, and a molded product obtained by using the resin composition.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, a thermoplastic polyester resin has been widely used as a resin having relatively high heat resistance, such as a film, a sheet, a fiber, and a molded article such as a container under a high temperature or outdoors.
This thermoplastic polyester resin is liable to be deteriorated by oxidation, hydrolysis and the like due to heating, alkali and moisture in the melt-kneading step in the production of molded articles. This deterioration is accelerated in the presence of an inorganic filler, a metal, a metal oxide, a dye or a pigment, and causes discoloration, a decrease in molecular weight, a decrease in mechanical properties, and the like.
[0003]
In addition, after a long period of time, the carboxyl group in the resin, and further the carboxyl group generated by hydrolysis of the resin itself, acts as a catalyst to hydrolyze the resin molecules, causing a decrease in physical properties and a decrease in the durability of the molded article. And there is a problem that the commercial value is greatly lost.
[0004]
As a means for solving such a problem, there is a technique of adding a phosphorus compound to deactivate the polymerization catalyst to prevent the property of preventing thermal degradation (see, for example, Patent Document 1). Was inadequate.
The technique of sealing a part or substantially all of the terminal of the carboxyl group of the aliphatic polyester with the monocarbodiimide compound (for example, see Patent Document 2) has not been sufficient to improve the physical properties of the polyester resin because it does not crosslink. In addition, the aromatic polycarbodiimide has a problem that it does not have heat resistance and is colored yellowish, gelation occurs, and the appearance of a molded article is deteriorated.
[0005]
The technology for suppressing thermal degradation and hydrolysis of a polyester resin by polycarbodiimide (for example, see Patent Document 3) has a problem that gelation occurs during molding and it is difficult to obtain a uniform molded product.
Further, a technique of blending a carbodiimide compound with a biodegradable plastic for the purpose of improving hydrolysis resistance has been disclosed (for example, see Patent Document 4). However, the carbodiimide compounds have insufficient heat resistance, and they are vaporized at the time of plastic molding, so that a sufficient effect cannot be obtained. Thus, there are problems such as low heat resistance of molded articles and poor appearance.
[0006]
[Patent Document 1]
JP-A-10-259296 [Patent Document 2]
JP 2001-261797 A [Patent Document 3]
Japanese Patent Application Laid-Open No. H10-43681 [Patent Document 4]
JP-A-11-80522 [Problems to be Solved by the Invention]
[0007]
[Means for Solving the Problems]
The inventors of the present invention have found that a combination use of an aliphatic polycarbodiimide compound and a hindered amine-based compound is effective for enhancing the hydrolysis resistance of a condensation-type thermoplastic resin molded article. Reached.
That is, the present invention is an aliphatic polycarbodiimide compound that blocks and deactivates the carboxyl terminus that causes the deterioration of the thermoplastic polyester resin, and suppresses the self-condensation and oxidative deterioration of the polycarbodiimide. A condensed thermoplastic resin composition containing a hindered amine compound to be acted on and a molded article using the composition.
[0008]
The first invention of the present invention is a condensation type thermoplastic resin composition comprising an aliphatic carbodiimide compound and a hindered amine compound.
In the second invention, the condensation type thermoplastic resin according to the first invention, wherein the content of the aliphatic polycarbodiimide compound is 0.01 to 60% by weight and the content of the hindered amine compound is 0.01 to 60% by weight. It is a resin composition.
[0009]
A third invention is the condensation thermoplastic resin composition according to the first or second invention, wherein the condensation thermoplastic resin is a polyester resin.
In a fourth aspect, the condensation type thermoplastic resin is selected from the group consisting of polylactic acid, polycaprolactone, a resin obtained using aliphatic dicarboxylic acid and polyhydric alcohol as main raw materials, and a polyester resin synthesized from microorganisms or plants. The condensed thermoplastic resin composition according to any one of the first to third inventions, which is at least one kind of microbial disintegrating resin.
[0010]
A fifth invention is a molded article obtained from the condensation type thermoplastic resin composition according to any one of the first to fourth inventions.
A sixth invention is a method for preventing deterioration of a condensed thermoplastic resin molded article, characterized by containing an aliphatic carbodiimide compound and a hindered amine compound.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described in detail.
Examples of the condensation type thermoplastic resin used in the present invention include a thermoplastic polyester resin. The thermoplastic polyester resin is a polymer obtained by condensation polymerization of a diol and a dicarboxylic acid.
Examples of the dicarboxylic acid include terephthalic acid, isophthalic acid, phthalic acid, naphthalenedicarboxylic acid, adipic acid, and sebacic acid. Examples of the diol include ethylene glycol, trimellilene glycol, tetramethylene glycol, and cyclohexane dimethanol.
Specifically, polyethylene terephthalate, polyethylene-p-oxybenzoate, poly-1,4-cyclohexylene dimethylene terephthalate, polyethylene 2,6-naphthalenedicarboxylate and the like can be used.
[0012]
These polyester resins may be a homopolyester or a copolyester. Examples of the copolymerization component include glycol components such as diethylene glycol, neopentyl glycol and polyalkylene glycol, adipic acid, sebacic acid, phthalic acid, isophthalic acid, and 2,6- Dicarboxylic acid components such as naphthalenedicarboxylic acid and 5-sodium sulfoisophthalic acid can be used.
[0013]
As the condensation type thermoplastic resin used in the present invention, a biodegradable resin can also be used. Examples of the biodegradable resin include polylactic acid, polycaprolactone, an aliphatic polyester resin obtained using aliphatic dicarboxylic acid and a polyhydric alcohol as raw materials, and a polyester resin synthesized from a microorganism or a plant.
[0014]
Specific examples include commercially available or prototype biodegradable resins of various companies, for example, polybutylene succinate, polyethylene succinate, polyethylene succinate, polybutylene succinate adipate, manufactured by Showa Polymer Co., Ltd. and Nippon Shokubai Co., Ltd., Mitsui Polylactic acid manufactured by Chemical Co., Cargill or Shimadzu, polycaprolactone manufactured by Daicel Chemical Co., Ltd., poly (3-hydroxybutyric acid-CO-3-hydroxyvaleric acid) manufactured by Monsanto (P (3HB-3HV)) And poly (3-hydroxybutyric acid-CO-4-hydroxybutyric acid) (P (3HB-4HB)) and poly (3-hydroxybutyric acid-CO-3-hydroxypropionate) (P (3HB-3HP)) No.
[0015]
The aliphatic polycarbodiimide compound used in the present invention is a compound having two or more carbodiimide bonds in the molecule (polymer main chain), and is obtained by reacting an arbitrary aliphatic isocyanate compound. If the polymerization degree (n) is too large, the stability of the aliphatic polycarbodiimide compound itself may be deteriorated, so that it is preferably 3 to 20, and the molecular weight is 500 or more and less than 10,000. Is preferred. The aromatic polycarbodiimide compound is not used in the present invention because it has a risk of self-condensation or aggregation, and the condensate or aggregate reduces the surface state or mechanical strength of the molded article.
[0016]
Examples of the isocyanate used as a raw material include water of hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, isophorone diisocyanate, polyfunctional aliphatic isocyanate, block polyfunctional aliphatic isocyanate, hydrogenated xylylene diisocyanate, hydrogenated diphenylmethane diisocyanate, and aromatic isocyanate. Additives and the like can be mentioned, and one or more of these can be preferably used.
[0017]
The hindered amine compound used in the present invention is a compound having a methylpiperidine skeleton. For example, dimethyl-1- (2-hydroxyethyl) -4-hydroxy-2,2,6,6-tetramethylpiperidine succinate polycondensate, poly [{6- (1,1,3,3-tetramethylbutyl) ) Amino-1,3,5-triazine-2,4-diyl {(2,2,6,6-tetramethyl-4-piperidyl) imino} hexamethylene} (2,2,6,6-tetramethyl -4-piperidyl) imino}], N, N'-bis (3-aminopropyl) ethylenediamine 2,4-bis [N-butyl-N- (1,2,2,6,6-pentamethyl-4piperidyl) ) Amino] -6-chloro-1,3,5-triazine condensate, bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate and the like.
[0018]
The average molecular weight of the hindered amine compound is preferably from 450 to 5,000. Particularly, a thin molded article having a high molecular weight having an average molecular weight of 2,000 or more is preferable.
[0019]
Aliphatic polycarbodiimide compounds and hindered amine compounds are not used in the present invention because the effects obtained when used alone in a condensation type thermoplastic resin are low. That is, the hindered amine compound suppresses the self-condensation and oxidative deterioration of the aliphatic polycarbodiimide compound, so that the aliphatic polycarbodiimide compound can be effectively reacted with the carboxyl group of the condensation type thermoplastic resin. Further, the hindered amine compound prevents the aliphatic polycarbodiimide compound from agglomerating with metal oxides, inorganic fillers such as talc, pigments, etc., and suppresses the agglomeration of these aggregates on the surface of the molded article, thereby reducing the appearance of the molded article Has the effect of improving
[0020]
In addition, the condensation type thermoplastic resin composition of the present invention may have appropriate additives as necessary within a range not impairing the effects of the present invention, for example, a heat stabilizer, an oxidation stabilizer, a weather stabilizer, and a charge stabilizer. You may mix | blend an inhibitor, a dye, a pigment, a dispersing agent, a coupling agent, etc.
[0021]
The production of the thermoplastic condensation type resin composition of the present invention is not particularly limited. For example, a condensation type thermoplastic resin, an aliphatic polycarbodiimide compound, a hindered amine compound, and, if necessary, various additives and coloring agents are added, and the mixture is mixed with a Henschel mixer, a tumbler, a disper, or the like, and the mixture is kneader, roll mill, or super mixer. , Henschel mixer, Sugi mixer, Vertical granulator, High-speed mixer, Furmatrix, Ball mill, Steel mill, Sand mill, Vibration mill, Attritor, Batch kneader such as Banbury mixer, Twin screw extruder, Single screw extruder By mixing, melt-kneading and dispersing with a rotor-type twin-screw kneader or the like, a condensation-type thermoplastic resin composition having a shape such as pellets, powders, granules, or beads can be obtained.
[0022]
The condensation type thermoplastic resin composition of the present invention may be a master batch containing an aliphatic polycarbodiimide compound and a hindered amine compound at a relatively high concentration, and diluted with a resin to be molded (base resin) at the time of molding. However, the compound may have a relatively low concentration of the aliphatic polycarbodiimide compound and the hindered amine compound, and may be used for molding with the same composition without being diluted with the resin to be molded.
[0023]
The content of the aliphatic polycarbodiimide compound in the compound or the molded article is 0.01% by weight or more from the viewpoint of obtaining sufficient hydrolysis resistance and mechanical properties and the like, from the viewpoint of preventing coloring of the molded article and maintaining flexibility. It is preferably at most 10% by weight. Further, the content of the hindered amine-based compound is preferably 0.01% by weight or more from the viewpoint of exhibiting sufficient performance, and is preferably 10% by weight or less from the viewpoint of preventing coloring of a molded article and suppressing costs.
[0024]
If the content of the aliphatic polycarbodiimide compound in the masterbatch is too small, it is difficult to obtain sufficient hydrolysis resistance, and it becomes necessary to add a large amount of masterbatch. 1% by weight or more is preferable because it easily causes trouble. In addition, if the amount is too large, the production efficiency of the master batch itself deteriorates, or uniformity becomes difficult because it is added in a small amount to the resin to be molded, and the distribution and dispersibility are deteriorated, and there is a tendency for dust to be generated. In addition, the content is preferably 60% by weight or less from the viewpoint of suppressing stickiness derived from the aliphatic polycarbodiimide compound, mixing with the resin to be molded, and suppressing generation of aggregates due to self-condensation in the molded product. In particular, it is preferably 40% by weight or less, and most preferably 5 to 30% by weight.
[0025]
The content of the hindered amine compound in the masterbatch is preferably 1% by weight or more, particularly preferably 5% by weight, from the viewpoint of exhibiting sufficient performance without adding a large amount of the masterbatch. When a molded product is obtained by adding a large amount of master batch, there is a possibility that good mechanical properties are not obtained. Further, if the content is large, the amount of the masterbatch added to the resin to be added becomes small, and there is a possibility that the hindered amine compound is unevenly distributed, and it becomes difficult to achieve uniformity. Therefore, the content is preferably 90% by weight or less. In particular, it is preferably at most 60% by weight.
[0026]
The molded article of the present invention may be obtained by any one of extrusion molding, injection molding and blow molding methods, or may be a powder coating obtained by pulverizing a condensation type thermoplastic resin composition.
[0027]
【Example】
Hereinafter, the present invention will be described specifically with reference to Examples. In the following description, “part” represents “part by weight” and “%” represents “% by weight”.
[0028]
(1) Production of compound [Examples 1 to 10]
As shown in Table 1, the components (a), (a) and (c) were uniformly mixed and melt-kneaded with a twin screw extruder having a diameter of 30 mm at a screw rotation speed of 250 rpm to obtain a compound. The melt kneading was carried out at a set temperature of 280 ° C. when the component (c) was PET, and at a set temperature of 200 ° C. when the component was PLA.
[0029]
[Comparative Examples 1 to 12]
As shown in Table 2, the components (A), (A) and (C) were uniformly mixed, and a compound was obtained in the same manner as in Examples 1 to 10.
[0030]
(2) Production of master batch [Examples 11 to 20]
As shown in Table 1, the components (A), (A) and (C) were uniformly mixed and melt-kneaded with a twin screw extruder having a diameter of 30 mm at a screw rotation speed of 250 rpm to produce a master batch. The melt kneading was carried out at a set temperature of 280 ° C. when the component (c) was PET, and at a set temperature of 200 ° C. when the component was PLA.
[0031]
[Comparative Examples 13 to 24]
As shown in Table 2, the components (A), (A) and (C) were uniformly mixed, and a master batch was obtained in the same manner as in Examples 11 to 20. In Comparative Examples 21 to 24, smoke was generated from the die head of the twin-screw extruder during production of the master batch.
[0032]
[Table 1]

[0033]
In Table 1, "aliphatic PC-1" represents dicyclohexylmethane-4,4-polycarbodiimide which is an aliphatic polycarbodiimide compound obtained from hydrogenated diphenylmethane diisocyanate;
"Aliphatic PC-2" is hexamethylene polycarbodiimide which is an aliphatic polycarbodiimide compound using hexamethylene diisocyanate as a raw material;
"Aliphatic PC-3" is an aliphatic polycarbodiimide compound derived from methylhexamethylene diisocyanate, 3-methylhexamethylene polycarbodiimide;
“HALS” refers to dimethylamine / 1,3,5-triazine / N, N-bis (2,2,6,6-tetramethyl-4-hydroxy-1,6-hexamethylenemethylenediamine / N- (2 A polycondensate of 2,6,6-tetramethyl-4- (benzyl) butylamine;
"PET" is polyethylene terephthalate (intrinsic viscosity = 0.83),
“PLA” used polylactic acid (intrinsic viscosity = 1.90).
[0034]
[Table 2]

[0035]
In Table 2, those common to Table 1 are in accordance with the description of Table 1.
"Aromatic PC" is an aromatic polycarbodiimide (available from Line Chem Inc.) using toluene diisocyanate as a raw material,
“Aliphatic MC” used diisopropylcarbodiimide.
[0036]
[Evaluation test]
The compounds and masterbatches obtained in the above Examples and Comparative Examples were evaluated as follows, and the results are shown in Tables 3 and 4.
a. The compounds obtained in the hydrolysis evaluation examples 1 to 10 and the comparative examples 1 to 12 were used as they were in the following compositions a1.
The master batches obtained in Examples 11 to 20 and Comparative Examples 13 to 24 were each diluted 10-fold with a base resin (each using the same resin as the component (C)). Mixed. The mixture was supplied to a single-screw extruder having a screw diameter of 30 mm and an L / D value of 30, and pelletized under the condition of a rotation speed of 100 rpm to produce a compound. The melt kneading was carried out at a set temperature of 280 ° C. when the component (c) was PET, and at a set temperature of 200 ° C. when the component was PLA.
[0037]
a1. After drying the compound obtained at an intrinsic viscosity at 140 ° C. for 2 hours, 0.5 g of the compound was weighed in a 100 ml volumetric flask, and 100 ml of a phenol: 1,1,2,2-tetrachloroethane = 1: 1 solution was accurately added. This was stirred and dissolved at 150 ° C. for 1.5 hours to obtain a measurement sample. The intrinsic viscosity value was measured using a capillary viscosity automatic measuring device (Shibayama Science Co., Ltd. “SS-600-L2”). With the case of only the resin to be molded (PET or PLA as the component (c)) as 100%, the retention of the intrinsic viscosity value of each compound was determined and evaluated according to the following criteria.
：: Retention rate of intrinsic viscosity value of 96% or more Δ: Retention rate of intrinsic viscosity value of 90% or more and less than 96% X: Retention rate of intrinsic viscosity value of less than 90%
a2. Retained mechanical properties The compounds obtained in Examples 1 to 10 and Comparative Examples 1 to 12 were injection-molded at the back pressure of 10 kg / cm ² with an injection molding machine using the same compositions to obtain plates. .
The master batches obtained in Examples 11 to 20 and Comparative Examples 13 to 24 were each diluted 10-fold with a base resin (each using the same resin as the component (C)). Mixed. The mixture was injection molded with an injection molding machine at a back pressure of 10 kg / cm ² to obtain a plate.
[0039]
For each plate, a tensile strength test (JIS K7113) and an Izod impact test (JIS K7110) were performed. And evaluated according to the following criteria.
：: 96% or more Δ: 90% or more and less than 96% ×: 90% or less
b. The surface state of the injection-molded plate prepared in the evaluation of the mechanical property retention in the molded article surface state evaluation a2 was observed with an electron microscope and visually, and evaluated according to the following criteria.
：: The surface is smooth, and no gels or bumps are found.
Δ: The surface is smooth, but a few small dots can be confirmed.
×: The surface is uneven, and many gels and bumps can be confirmed.
[0041]
[Table 3]

[0042]
[Table 4]

[0043]
【The invention's effect】
Since the condensation type thermoplastic resin composition of the present invention contains an aliphatic polycarbodiimide compound and a hindered amine compound, it has practically sufficiently high hydrolysis resistance and heat resistance.
Therefore, the condensed thermoplastic resin molded product obtained by using the same has good mechanical properties and surface condition, and thus can be used more widely than before.

Claims (6)

A condensed thermoplastic resin composition comprising an aliphatic carbodiimide compound and a hindered amine compound. The condensation type thermoplastic resin composition according to claim 1, wherein the content of the aliphatic polycarbodiimide compound is 0.01 to 60% by weight and the content of the hindered amine compound is 0.01 to 60% by weight. 3. The condensation type thermoplastic resin composition according to claim 1, wherein the condensation type thermoplastic resin is a polyester resin. At least one microbial disintegration selected from the group consisting of polylactic acid, polycaprolactone, a resin obtained using aliphatic dicarboxylic acid and polyhydric alcohol as main raw materials, and a polyester resin synthesized from microorganisms or plants; The condensation type thermoplastic resin composition according to any one of claims 1 to 3, which is a conductive resin. A molded article obtained from the condensation type thermoplastic resin composition according to claim 1. A method for preventing deterioration of a condensed thermoplastic resin molded article, comprising an aliphatic carbodiimide compound and a hindered amine compound.