JP2001254005A - Aliphatic polyester resin composition and film thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an aliphatic polyester resin composition excellent in tear strength and impact strength and exhibiting good biodegradability, and its film. SOLUTION: The aliphatic polyester resin composition comprises 100 parts by mass of a resin composition composed of (a) 50-80 mass % of an aliphatic polyester and (b) 20-50 mass % of a filler, and (c) 0.5-10 parts by mass of a fatty acid. The film is composed of the resin composition.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aliphatic polyester resin composition suitable for compost bags, agricultural films and packaging materials having high tear strength, high impact strength and biodegradability, and films thereof. .

[0002]

2. Description of the Related Art It is known that biodegradable resins are relatively easily decomposed in water and soil. Therefore, it is receiving worldwide attention in terms of environmental conservation such as the problem of waste disposal.
Among these, aliphatic polyesters have physical properties close to that of polyethylene, and films obtained by molding the resins are expected to be used as films for agricultural materials, civil engineering materials, vegetation materials, packaging materials, etc. (JP-A-5-271377, JP-A-6-170941)
Issue publication).

[0003]

However, all of the above films have insufficient tear strength and have a practical problem. The present invention has been made in view of such circumstances, and has as its object to provide an aliphatic polyester resin composition having excellent tear strength and a film thereof.

[0004]

Means for Solving the Problems The present inventors have made intensive studies and as a result have completed the present invention. That is, the present invention provides a resin composition 1 comprising (a) 50 to 80% by mass of an aliphatic polyester and (b) 20 to 50% by mass of a filler.
The present invention provides an aliphatic polyester resin composition containing (c) a fatty acid in an amount of 0.5 to 10 parts by mass with respect to 00 parts by mass, and a film thereof. The present invention also relates to (a) 50 to 80% by mass of an aliphatic polyester and (b) a filler 2
Aliphatic polyester resin composition containing (c) 0.5 to 10 parts by weight of a fatty acid and (d) 0.3 to 5 parts by weight of a fatty acid metal salt with respect to 100 parts by weight of a resin composition of 0 to 50% by weight. An object and a film thereof are provided. In addition, the latter invention adds heat aging resistance to the effect of the former invention.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION As the aliphatic polyester (a) used in the present invention, a polyester biosynthesized by a microorganism, a polylactic acid, a polycaprolactone, a polyester containing glycol and an aliphatic dicarboxylic acid as main components or a polyester thereof. And copolymers. The aliphatic polyester used in the present invention has a melting point of 50 to 190 ° C.
And a weight-average molecular weight of 50,000 or more is preferable for obtaining a good molded product.

Specific examples of the aliphatic polyester include "Biopol", a biosynthetic system by microorganisms (manufactured by Monsanto Japan), and "Lacia", a polylactic acid system (manufactured by Mitsui Chemicals).
And "Lacty" (manufactured by Shimadzu Corporation), polycaprolactone-based "Placcel" (manufactured by Daicel Chemical Industries, Ltd.), and "Bionole" (manufactured by Showa Kogyo Co., Ltd.) based on glycol and aliphatic dicarboxylic acid. Can be The above-mentioned resins may be used by blending two or more kinds.

[0007] Of these, polyesters containing glycol and aliphatic dicarboxylic acid as main components are preferred. As the glycol, for example, ethylene glycol, 1,4-
Examples thereof include butanediol, 1,6-hexanediol, decamethylene glycol, and neopentyl glycol, and these may be used in combination. Examples of the aliphatic dicarboxylic acid include succinic acid, adipic acid, suberic acid, sebacic acid, dodecane diacid and anhydrides thereof, and the like.
These can be used in combination. Further, the glycol and the aliphatic dicarboxylic acid can be used in any combination. As other components, trifunctional or 4
A small amount of functional polyhydric alcohol, oxycarboxylic acid or polycarboxylic acid may be added. Preferable examples include the above bionoles # 1000 and # 3.
000.

The filler (b) in the present invention is a substance generally added in the synthetic resin field for the purpose of improving various properties such as strength and durability. As the type of the filler, there are an inorganic type and an organic type, but they can be appropriately selected and used depending on the intended film. Examples of the inorganic filler include oxides of metals such as magnesium, calcium, barium, zinc, zirconium, molybdenum, silicon, antimony, and titanium, hydrates (hydroxides), sulfates, carbonates, and silicates. Such compounds, double salts thereof, and mixtures thereof are roughly classified. Specific examples include, for example, aluminum oxide (alumina), its hydrate, calcium hydroxide, magnesium oxide (magnesia), magnesium hydroxide, zinc oxide (zinc white), lead oxide such as lead tin and lead mortar. , Magnesium carbonate, calcium carbonate, basic magnesium carbonate, white carbon, mica, talc, glass fiber, glass powder, glass beads, clay,
Examples include diatomaceous earth, silica, wollastonite, iron oxide, antimony oxide, titanium oxide (titania), lithopone, pumice powder, ammonium sulfate (eg, gypsum), zirconium silicate, barium carbonate, dolomite, molybdenum disulfide, and iron sand.

On the other hand, examples of the organic filler include cellulose-based and starch-based (including plasticized starch). Preferred examples of the organic filler include cellulose powder, wood powder, waste paper powder, rice husk powder, starch, plasticized starch and the like. The diameter or size of these fillers is 5
Those having a size of not more than 1 micron (more preferably not more than 1 micron, especially not more than 0.5 micron) are preferred. In the present invention, the blending ratio of the filler in the total amount of the aliphatic polyester and the filler is 20 to 50% by mass, preferably 22 to 45% by mass, and particularly preferably 25 to 45% by mass.
40% by mass. If the compounding ratio of the filler is less than 20% by mass, the effect of improving the tear strength cannot be expected. On the other hand, 50
Exceeding the mass% is not preferred because it affects the molding stability.

Further, the fatty acid (c) in the present invention includes a chain carboxylic acid having one carboxyl group, and may be linear or may have a side chain. Specific examples of fatty acids include, for example, caproic acid, caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid, behenic acid, palmitoleic acid, oleic acid, eicosenoic acid, erucic acid, elaidic acid , Trans-11 eicosenoic acid, trans-13 docosenoic acid, linoleic acid, linolenic acid, ricinoleic acid, erucic acid and the like. The above-mentioned fatty acids may be used by blending two or more kinds.
Among these, stearic acid and lauric acid are preferred. The amount of the fatty acid in the present invention is 0.5 to 10 parts by mass, preferably 0.5 to 5 parts by mass, particularly preferably 0.5 to 5 parts by mass, based on 100 parts by mass of the resin composition comprising the aliphatic polyester and the filler. Is 0.8 to 2 parts by mass. If the amount of the fatty acid is less than 0.5 parts by mass, the effect of improving the impact strength cannot be expected. On the other hand, if it exceeds 10 parts by mass, bleeding from the film is not preferred.

Further, the (d) fatty acid metal salt in the present invention includes a compound in which the hydroxyl group of the above fatty acid is substituted with a metal atom. As the metal atom, 1A of the periodic table,
Group 2A and 3B atoms are preferred. Examples of preferred metal atoms include potassium, calcium, magnesium, aluminum and barium. Metals of other groups, such as zinc or iron, are not preferred because they rather accelerate thermal degradation. Particularly preferred examples include calcium stearate, magnesium stearate and the like, and these may be used by blending. The amount of the fatty acid metal salt is 0.3 to 5 parts by mass with respect to 100 parts by mass of the resin composition comprising the aliphatic polyester and the filler.
It is preferably from 0.3 to 2 parts by mass, particularly preferably from 0.5 to 1 part by mass. The amount of the fatty acid metal salt is 0.
If the amount is less than 3 parts by mass, the effect of improving heat resistance deterioration cannot be expected.
On the other hand, if it exceeds 5 parts by mass, bleeding from the film is not preferred.

The method for producing the polyester film of the present invention includes, for example, a method in which the above-mentioned components are melt-mixed and formed into a film by a known molding method. Examples of the film forming method include water-cooled or air-cooled inflation molding, T-die film extrusion molding, extrusion lamination molding, and the like. Further, as the film of the present invention,
The film may be further uniaxially or biaxially stretched.

If desired, the film of the present invention may contain additives commonly used in the art, for example, antioxidants, heat stabilizers, ultraviolet inhibitors, antistatic agents, flame retardants, crystallization accelerators. May be added in a range that does not impair the characteristics of the present invention. Specifically, hindered phenolic antioxidants such as pt-butylhydroxytoluene and pt-butylhydroxyanisole as antioxidants; triphenylphosphite as heat stabilizers;
Trisnolylphenyl phosphite and the like; pt-butylphenyl salicylate, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxy-2′-carboxybenzophenone as an ultraviolet absorber;
2,4,5-trihydroxybutyrophenone and the like; N, N-bis (hydroxyethyl) alkylamine, alkylamine, alkylallylsulfonate, alkylsulfonate and the like as antistatic agents; hexabromocyclododecane, tris- and the like as flame retardants (2,3-dichloropropyl) phosphate, pentabromophenyl allyl ether and the like; Examples of the crystallization accelerator include talc, holon nitrite, polyethylene terephthalate, poly-transcyclohexane dimethanol terephthalate and the like.

[0014]

The present invention will be described in more detail with reference to the following examples. The melting point was measured using a differential scanning calorimeter (manufactured by Seiko Electronics Co., Ltd., DSC200) at a heating rate of 10 ° C./min. MFR was measured under the conditions of a temperature of 190 ° C. and a load of 2.16 kgf in accordance with JIS K7210. The weight average molecular weight (hereinafter, referred to as “Mw”) is determined by gel chromatography (Showex GPC, Shodex GPC Sy).
The measurement was carried out under the following conditions using STEM-11). Solvent: Hexafluoroisopropyl alcohol solution containing 15 mmol / l ammonium acetate Resin concentration: 0.1% by mass Calibration curve: PMMA standard sample (Showa Denko, Sho
Dex Standard M-75) The biodegradability was measured by burying a film cut into 10 cm square at a depth of about 10 cm from the ground next to the tennis court in Showa Denko KK, and burying it for one year with nylon mesh. The amount of weight loss of the resin component was measured, and the reduction ratio was evaluated in the following four steps. ◎: 80% or more…: 50 to less than 80% △: 10 to less than 50% ×: Less than 10% The heat deterioration resistance was 19 at a temperature of 19 in accordance with JIS K7210.
0 ° C., 21.18 MPa load, MFR measured at 30 minutes residence time (MFR30) and normal residence time
Ratio to the value at 6 minutes (MFR6) (MFR30 / MFR)
According to 6), evaluation was performed in the following four stages. ◎: MFR ratio <2.0: 2.0 ≦ MFR ratio <5.0 △: 5.0 ≦ MFR ratio <10.0 ×: MFR ratio ≧ 10.0 The tear strength of the film conforms to IS P8116. The impact strength was measured in accordance with JIS P-8134 using an Elmendorf tear tester.

The following three types were used as the aliphatic polyester. Polyester A: Bionore # 1001 (manufactured by Showa Polymer Co., Ltd., melting point: 113 ° C., MFR: 1.4 g / 10 minutes,
Mw: 220,000) Polyester B: Bionore # 3001 (manufactured by Showa Polymer Co., Ltd., melting point: 95 ° C., MFR: 1.2 g / 10 min, M
w; 240000) Polyester C; Praxel H-7 (manufactured by Daicel Chemical Co., Ltd., melting point: 60 ° C., MFR: 3.5 g / 10 min, M
w; 120,000) As a filler, talc (Micron White # manufactured by Hayashi Kasei Co., Ltd.)
5000SA, average particle size 2 microns), calcium carbonate (Vigot10, Shiroishi Industry Co., Ltd., average particle size 0.1 micron) (hereinafter referred to as "Tancar A"), (Shiroishi Industry micron powder, average particle size 1 micron) (hereinafter, "Tancar
B "), (Shiroishi Kogyo Whiten SB Red, average particle size 3.7 microns) (hereinafter referred to as" Tancar C "), high-purity crystalline silica (Tatsumori Crystallite 5X, average particle size 1.3) Micron) (hereinafter referred to as "silica A") and soft silica silica (IMSILA-8 manufactured by Tatsumori, average particle size 2.2 microns) (hereinafter referred to as "silica B"). Pure fatty acid stearic acid powder and first-class reagent were used as fatty acids. As the fatty acid metal salt, pure chemical calcium stearate (hereinafter referred to as “Ca-St”), a first-class reagent was used.

Examples 1 to 10 and Comparative Examples 1 to 5 Melt kneading aliphatic polyesters, fillers and fatty acids whose types and amounts are shown in Table 1 using a bidirectional twin screw extruder having a screw diameter of 30 mm. Thus, a composition pellet was obtained. The heat deterioration resistance of each of the obtained pellets was evaluated. Further, the obtained pellets were vacuum-dried at a temperature of 50 ° C. for 24 hours, and then a film having a thickness of 30 μm and a folded width of 470 mm (equivalent to a blow-up ratio of 3) was formed using an inflation molding machine manufactured by Yoshii Iron Works. The tear strength, impact and biodegradability of each of the obtained films were evaluated. Table 2 shows the above results.

[0017]

[Table 1]

[0018]

[Table 2]

[0019]

The aliphatic polyester resin composition of the present invention is particularly excellent in tear strength and impact, and has good biodegradability, so that it can be used as an agricultural film, a compost bag, or a film for packaging materials. Available and useful in the field.

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Tsuyoshi Takahashi 3-2 Chidori-cho, Kawasaki-ku, Kawasaki-shi, Kanagawa Prefecture Showa Denko KK Kawasaki Laboratory (72) Inventor Ryoji Ishioka 3-, Kandanishikicho, Chiyoda-ku, Tokyo 20 F-term in Showa Takashi Carbon Co., Ltd. EG048 FA046 FA086 FD012 FD016 GA01 GG02

Claims (5)

[Claims] 1. A resin composition comprising (a) 50 to 80% by mass of an aliphatic polyester and (b) 20 to 50% by mass of a filler, and (C) 0.5 to 10 parts by mass of a fatty acid with respect to 100 parts by mass. An aliphatic polyester resin composition to be contained. 2. 100 parts by mass of a resin composition comprising (a) 50 to 80% by mass of an aliphatic polyester and (b) 20 to 50% by mass of a filler;
An aliphatic polyester resin composition containing parts by mass and (d) 0.3 to 5 parts by weight of a fatty acid metal salt. 3. An aliphatic polyester having a melting point of 50-1.
3. The aliphatic polyester resin composition according to claim 1, which has a temperature of 90 ° C. and a weight average molecular weight of 50,000 or more. 4. The aliphatic polyester resin composition according to claim 1, wherein the filler has an average particle size of 1 μm or less. 5. A film obtained by molding the aliphatic polyester resin composition according to claim 1.