JP2000017157A - Aliphatic polyester composition and its molding product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an aliphatic polyester composition excellent in mechanical strengths such as tear strength, and having good heat-sealability, and to provide a molding product thereof. SOLUTION: The aliphatic polyester composition and its molding product comprise (A) 60-99.9 wt.% aliphatic polyester, and (B) 40-0.1 wt.% organic clay complex obtained by treating laminar silicic acid salt with an organic cation. The aliphatic polyester has 50-190 deg.C melting point, and >=50,000 weight average molecular weight, and the organic cation is at least one kind selected from a group of primary to tertiary amine salts, a quarternary ammonium salt and amine acid salts.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aliphatic polyester composition having excellent mechanical strength such as tear strength and good heat sealability.

[0002]

2. Description of the Related Art In recent years, aliphatic polyesters have been developed as so-called biodegradable plastics which decompose in the natural environment in water or in soil, and some of them have been put to practical use. These resins are expected to be applied to agricultural materials, civil engineering materials, vegetation materials, packaging materials, and the like in the future.

[0003]

However, although the above-mentioned aliphatic polyester can be molded into a film or the like, the molding stability is inferior to polyethylene or the like, and various mechanical strengths are still insufficient. Was. The present invention has been made in view of such a situation, is excellent in molding stability and mechanical strength, particularly excellent tear strength,
Another object of the present invention is to provide an aliphatic polyester composition having good heat sealability.

[0004]

Means for Solving the Problems As a result of intensive studies, the present inventors have found that the above object can be achieved by adding a specific organoclay composite, and based on this finding, the present invention has been achieved. Was completed. That is, the present invention relates to (A) an aliphatic polyester of 60 to 99.9% by weight.
And (B) an organopolyester composite obtained by treating a layered silicate with an organic cation.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION As the aliphatic polyester (A) 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 copolymer thereof are used. Coalescence and the like. The aliphatic polyester used in the present invention preferably has a melting point of 50 to 190 ° C. and a weight average molecular weight of 50,000 or more in order to obtain a good molded product. Specific examples of aliphatic polyesters include microbial "Biopol"
(Manufactured by Nippon Monsanto Co., Ltd.), polylactic acid-based "Lacia"
(Manufactured by Mitsui Chemicals) and "Lacty" (manufactured by Shimadzu Corporation), polycaprolactone-based "Placel" (manufactured by Daicel Chemical), and "Bionole" (based on glycol and aliphatic dicarboxylic acid) as a main component (Showa Koto) (Manufactured by Kagaku).

[0006] Among them, polyesters containing glycol and aliphatic dicarboxylic acid as main components are preferred. As the glycol, for example, ethylene glycol, 1,4
-Butanediol, 1,6-hexanediol, decamethylene glycol, neopentyl glycol, and the like, 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. Further, a small amount of trifunctional or tetrafunctional polyhydric alcohol, oxycarboxylic acid or polyvalent carboxylic acid may be added as another component. Preferred examples include the above bionoles # 1000 and #
3000.

The (B) organoclay composite of the present invention is a composite obtained by treating a layered silicate with an organic cation. The layered silicate used in the present invention includes 2:
Examples include those mainly containing type 1 clay minerals, and typical examples include smectite, vermiculite, and mica. Examples of smectites include montmorillonite, beidellite, hectorite, saponite.
Vermiculite includes dioctahedral vermiculite, trioctahedral vermiculite and the like. Examples of mica include teniolite, tetrasilicic mica, muscobite, illite, sericite, phlogovite, biotite and the like. These silicates may be natural minerals, or may be those synthesized by hydrothermal synthesis, melting method, solid phase method and the like.

The organic cation used in the present invention includes 1
And tertiary to tertiary amines and their salts, quaternary ammonium salts, diamines and amino acid derivatives and their salts. Coconut amine,
Examples include natural extracts such as tallowamine, octylamine, laurylamine, stearylamine, oleylamine and the like. Examples of the secondary amine include distearylamine, dimethylcoconutamine, dimethyloctylamine, dimethyldecylamine, dimethyllaurylamine, dimethylmyristylamine, dimethylpalmitylamine, and dimethylstearylamine. Examples of the tertiary amine include dilauryl monomethylamine and trioctylamine. As the quaternary ammonium ion, dodecyltrimethylammonium ion, myristyltrimethylammonium ion, cetyltrimethylammonium ion, stearyltrimethylammonium ion, aralkyltrimethylammonium ion, behenyltrimethylammonium ion, myristyldimethylethylammonium ion, cetyldimethylethylammonium ion, Stearyl dimethyl ethyl ammonium ion, aralkyl dimethyl ethyl ammonium ion,
Behenyl dimethyl ethyl ammonium ion, myristyl diethyl methyl ammonium ion, cetyl diethyl methyl ammonium ion, stearyl diethyl methyl ammonium ion, aralkyl diethyl methyl ammonium ion, behenyl diethyl methyl ammonium ion, benzyl dimethyl myristyl ammonium ion,
Benzyl dimethyl cetyl ammonium ion, benzyl dimethyl stearyl ammonium ion, benzyl dimethyl behenyl ammonium ion, benzyl methyl ethyl cetyl ammonium ion, benzyl methyl ethyl stearyl ammonium ion, dibehenyl dihydroxy ethyl ammonium ion, dodecyl monomethyl diethanol ammonium ion, diocta dimethyl ammonium Ions and the like. Examples of the diamine include stearyl propylene diamine and tallow propylene diamine. Examples of the amino acid derivatives include coconutamine acetate, stearylamine acetate and the like. Of these, quaternary ammonium ions are preferable, and among them, dodecylmonomethyldiethanolammonium ion and dioctadimethylammonium ion are suitably used. Further, the salt is not particularly limited, but chloride or bromide is preferred.

As a method of treating the layered silicate with the above-mentioned organic cation, the layered silicate powder is suspended in a solvent such as water or alcohol, and the organic cation is added in the form of a salt, stirred and then filtered. It is obtained by washing and drying. By this treatment, the metal cations existing between the layers of the layered silicate are replaced with the organic cations and coordinated between the layers to form an organic clay complex. The ion exchange capacity of the layered silicate can be measured by a method such as a methylene blue adsorption method (Japan Bentonite Industry Association test method, JBAS-107-91). The organic cation substitution amount is calculated from a weight loss due to thermal decomposition of an organic substance using a thermogravimetric device such as a suggestive heat / thermobalance measurement (TG-DTA) device.

The organic cation substitution amount in the organoclay composite according to the present invention is represented by milliequivalents per 100 g of the layered silicate, and is generally 25 to 260 meq / 100 g, preferably 50 to 200 meq / 100 g. In particular, 75 to 150 meq / 100 g is suitable.

The aliphatic polyester composition of the present invention is a composition comprising 60 to 99.9% by weight of an aliphatic polyester and 40 to 0.1% by weight of the above-mentioned organoclay composite. Is preferably 30 to 0.5% by weight, particularly preferably 20 to 1% by weight. If the content of the organic composite is less than 0.1% by weight, the effect of improving mechanical strength cannot be expected. On the other hand, if it exceeds 40% by weight, dispersion becomes insufficient, which is not preferable. The composition of the present invention can be obtained by uniformly mixing and dispersing the above components using a mixing device known in the art such as an extruder. The mixing temperature is preferably about 150 to 200 ° C.

The composition of the present invention can be used for molded articles by injection molding, blow molding, stretch blow molding and the like, and sheet articles by foamed sheet molding, board molding and the like. is there. Film forming methods include water-cooled or air-cooled inflation molding,
Extrusion molding using a T-die, extrusion lamination molding, and the like can be given. These films may be further stretch-formed. The stretching treatment improves the mechanical properties and also improves the water vapor and air barrier properties.

The resin composition of the present invention may further contain, if desired, additives usually used in the technical field, such as antioxidants, heat stabilizers, ultraviolet absorbers, lubricants, antistatic agents, flame retardants, and crystals. An accelerator, a filler, and the like may be added in a range that does not impair the characteristics of the present invention. Specifically, pt-butylhydroxytoluene as an antioxidant,
Hindered phenolic antioxidants such as pt-butylhydroxyanisole; triphenyl phosphite, trilauryl phosphite, trisnolyl phenyl phosphite, etc. as heat stabilizers;
t-butylphenyl salicylate, 2-hydroxy-4
-Methoxybenzophenone, 2-hydroxy-4-methoxy-2'-carboxybenzophenone, 2,4,5-
Trihydroxybutyrophenone, etc .; calcium stearate, zinc stearate, barium stearate, sodium palmitate, etc. as lubricant; N, N-bis (hydroxyethyl) alkylamine as antistatic,
Alkylamine, alkylallyl sulfonate, alkyl sulfonate, etc .; hexabromocyclododecane, tris- (2,3-dichloropropyl) phosphate, pentabromophenyl allyl ether, etc. as flame retardants; talc, boron nitrite as crystallization promoters , Polyethylene terephthalate, poly-transcyclohexane dimethanol terephthalate, etc .; calcium carbonate, silica, titanium oxide, talc, mica, barium sulfate, alumina, etc. as inorganic fillers; and wood powder, rice husk, newspaper, etc. as organic fillers. Waste paper, various types of starch (including those obtained by changing the structure of pregelatinized starch, etc.), cellulose 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 weight ・ Calibration curve: PMMA standard sample (manufactured by Showa Denko KK, S
hodex Standard M-75) The tear strength was measured in accordance with JIS P8116 (Elmendorf method) by measuring the strength in the film flow direction (MD) and its perpendicular direction (TD). Young's modulus is ASTM D88
2, the pulling speed is 5 mm / min, the chuck interval is 250
mm. Film impact is JIS
It was measured with a 1-inch hemisphere according to P8134. The heat sealing property is as follows: a film having a width of 15 mm is melted from the melting point of the resin to the melting point +5 under the conditions of a sealing time of 1 second and a sealing pressure of 2 kg / cm ^2.
Sealed parts welded to 0 ° C at 5 ° C intervals are JIS Z1
Measurement was performed under the conditions of a tensile speed of 300 mm / min and a chuck interval of 50 mm according to 707, and the following 4
It was evaluated on a scale.・: 1000 g / 15 mm or more ○: 800 to less than 1000 g / 15 mm △: 500 to less than 800 g / 15 mm ×: less than 500 g / 15 mm Water vapor permeability conforms to JIS Z0208. Temperature 40
Measured in ° C. The oxygen permeability is ASTM D398.
Measured at a temperature of 20 ° C. according to 5-81. The biodegradability was measured by reducing the resin component after burying a 10cm square film at a depth of about 10cm from the ground surface next to the tennis court in the Research Institute of Showa Denko Co., Ltd. between nylon meshes for 1 year. Measure the amount and determine the percentage of decrease
It was evaluated on a scale. ◎ ・ ・ ・ ・ 80% or more ○ ・ ・ ・ ・ 50 to less than 80% △ ・ ・ ・ ・ 10 to less than 50% × ・ ・ ・ ・ less than 10%

The following four kinds were used as the aliphatic polyester.・ Polyester A Bionole # 1000 (manufactured by Showa Polymer) Melting point: 113 ° C., MFR: 1.0 g / 10 min Mw: 140000 ・ Polyester B bionore # 3000 (manufactured by Showa Polymer) Melting point: 95 ° C., MFR: 1 Polyester C Biopol D-611G (manufactured by Monsanto) Melting point: 136 ° C., MFR: 45 g / 10 minutes Mw: 260000 Polyester D Praxel-H7 (manufactured by Daicel Chemical) Melting point: 60 C, MFR: 3.5 g / 10 min Mw: 120,000 Fluorine-type tetrasilicic mica (manufactured by Corp Chemical; Somasif ME-100, ion exchange capacity: 107 meq / 100 g) as a layered silicate (hereinafter referred to as “mica”) ) Was used. As organic cations, dodecylmonomethyldiethanolammonium chloride (manufactured by Lion Akzo; Esoguard C-12) (hereinafter referred to as “cation A”) and dioctadimethyldodecylammonium chloride (manufactured by Kao Corporation; coatamine D86P) (hereinafter referred to as “cation B”) Was used.

Production Example of Organic Clay Composite 30 parts of mica is added to 300 parts of distilled water and stirred for 3 hours to form a suspension. Then, the mixture is heated to a temperature of 60 ° C. while stirring. Separately, a solution obtained by dissolving 14 parts of cation A in 200 parts of distilled water at a temperature of 60 ° C. is added to the suspension,
The mixture was further stirred for 1 hour to prepare a homogeneous suspension. Thereafter, the suspension was washed and centrifugally filtered to obtain a complex. Furthermore, after drying with hot air, coarsely pulverizing with a water-cooled wheelie mill, finely pulverizing with a jet mill pulverizer (manufactured by Hosokawa Micron),
Only those having an average particle size of 5 μm or less were classified to obtain composite fine powder (hereinafter, referred to as “composite A”). The average particle size of the obtained composite A was 1.8 μm. The same operation as described above was performed using cation B to obtain a composite fine powder (hereinafter, referred to as “composite B”). The average particle size of the obtained composite B was 2.0 microns.

Examples 1-9, Comparative Examples 1-5 Aliphatic polyester and organoclay composites whose types and amounts are shown in Table 1 were co-extruded with a screw diameter of 38 mm in the same twin-screw extruder (manufactured by Toshiba Machine Co., Ltd.). TEM-35BS, vent type) to obtain a composition. After vacuum drying the obtained composition at a temperature of 50 ° C. for 24 hours, a blown film molding machine manufactured by Yoshii Teiko Co., Ltd. (screw diameter 55 mm)
A film having a folding width of 630 mm (the blow ratio corresponds to 4) and a thickness of 30 μm was formed using φ, L / D = 28, die diameter 100 mmφ, ring gap 1.2 mm). The molding speed was 20 m / min. The tear strength, Young's modulus, film impact, heat sealability and biodegradability of each of the obtained films were measured. Table 1 shows the obtained results.

Examples 10 and 11, Comparative Examples 6 and 7 The compositions used in Examples 3 and 5 and Comparative Examples 1 and 2 were each prepared using a 600 mm wide T-die type film forming machine. A 30 micron film was made. The water vapor permeability and oxygen permeability of each of the obtained films were measured. The results are shown in Table 2 as Examples 10 and 11 and Comparative Examples 6 and 7.

[0019]

[Table 1]

[0020]

[Table 2]

[0021]

The aliphatic polyester composition of the present invention comprises:
Especially excellent in mechanical strength such as tear strength in the film,
Further, since the heat sealing property is good, it is useful because it can be used in various fields such as agricultural materials, civil engineering materials, vegetation materials, and packing materials.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4F071 AA44 AA81 AA84 AB26 AB30 AC12 AF16 AF59 BA01 BB06 BB09 BC01 4J002 CF031 DJ006 EN116 EN136 FB086 GA01 GG02 GL00

Claims (5)

[Claims] (A) aliphatic polyester 60 to 9
An aliphatic polyester composition comprising 9.9% by weight and 40 to 0.1% by weight of an organoclay composite (B) obtained by treating a layered silicate with an organic cation. 2. An aliphatic polyester having a melting point of 50 to 1
The aliphatic polyester composition according to claim 1, which has a temperature of 90 ° C and a weight average molecular weight of 50,000 or more. 3. The aliphatic polyester composition according to claim 1, wherein the organic cation is at least one selected from the group consisting of primary to tertiary amine salts, quaternary ammonium salts and amino acid salts. 4. An inflation film obtained by inflation molding the aliphatic polyester composition according to claim 1. 5. A film obtained by extrusion-molding the aliphatic polyester composition according to claim 1.