JP2001164097A - Blow molded container made of aliphatic polyester and method for molding the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a blow molded container excellent in molding stability and steam barrier properties and having biodegradability and to provide a method for molding the same. SOLUTION: This blow molded container made of an aliphatic polyester comprises (a) 60-99.9 mass % of the aliphatic polyester and (b) 40-0.1 mass % of an organic clay composite. The method for molding comprises carrying out a stretch blow molding by the blow molding according to a cold parison method or the blow molding according to hot parison method.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a hollow molded container made of an aliphatic polyester and a method for molding the same. More specifically, it has high water vapor barrier properties and excellent mechanical strength,
The present invention relates to an aliphatic polyester hollow molded container suitable for biodegradable wet tissues, soft drinks, shampoos, cosmetic containers, and the like, and a molding method thereof.

[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 polyesters can be hollow-molded for the time being, they have problems such as inferior molding stability and insufficient water vapor barrier properties as compared with polyethylene and the like. .

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a hollow molded container made of an aliphatic polyester having excellent molding stability and water vapor barrier properties, and a method for molding the same.

[0005]

Means for Solving the Problems As a result of intensive studies, the present inventors have found that the above object can be achieved by a hollow molded container made of an aliphatic polyester to which a specific organoclay composite has been added, Based on this finding, the present invention has been completed.

That is, the present invention relates to (a) 60 to 99.9% by mass of an aliphatic polyester and (b) an organoclay composite 40.
The present invention provides an aliphatic polyester hollow molded container excellent in water vapor barrier properties, characterized by comprising from 0.1 to 0.1% by mass, and a molding method thereof.

Hereinafter, the present invention will be described in detail. The aliphatic polyester (a) in the present invention is preferably a polyester biosynthesized by a microorganism, a polylactic acid, a polycaprolactone, a polyester composed of a raw material mainly composed of glycol and an aliphatic dicarboxylic acid, or a copolymer thereof. Is mentioned. Among these aliphatic polyesters, those having a melting point of 50 to 190 ° C. and a weight-average molecular weight of 50,000 or more are obtained due to the molding stability in stretch hollow molding such as hot parison hollow molding and cold parison hollow molding. Since it is excellent, it is more preferable to obtain a good hollow molded container.

Specific examples of the aliphatic polyesters include "Biopol" (a product of Monsanto Japan), "Lacia" (a product of Mitsui Chemicals) and "Lacty" (a product of Shimadzu Corporation) of a polylactic acid type. Examples include polycaprolactone-based "Placcel" (manufactured by Daicel Chemical Co., Ltd.), and "Bionole" (manufactured by Showa Kogyo Co., Ltd.) comprising a raw material containing glycol and an aliphatic dicarboxylic acid as main components.

Of these, aliphatic polyesters composed of raw materials containing glycol and aliphatic dicarboxylic acid as main components are preferred. Examples of the glycol include 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, dodecanedioic acid and anhydrides thereof, and these can be used in combination. Further, the glycol and the aliphatic dicarboxylic acid can be used in any combination. As other components, a small amount of a polyfunctional compound having a functional group such as isocyanate which can react with an alcohol and / or a carboxylic acid, a polyhydric alcohol having three or more functional groups, an oxycarboxylic acid or a polycarboxylic acid is added in a small amount. It may be added.

Preferred examples include the above-mentioned bionoles # 1000 and # 3000.

The (b) organoclay composite according to the present invention comprises:
Preferably, it is a composite in which a layered silicate of an inorganic component is converted into an organophilic compound.

[0012] Layered silicates are rich in changes such as chemical composition and crystal structure, and there is no established classification and nomenclature. The feature of the layered silicate mentioned here is a layered crystal, which belongs to phyllosilicate in mineralogy. Particularly, there is a 2: 1 type phyllosilicate composed of two tetrahedral layers and one octahedral layer, and a 1: 1 type phyllosilicate composed of one tetrahedral layer and one octahedral layer. Typical minerals of type phyllosilicate include smectite, vermiculite,
There are mica, and 1: 1 phyllosilicates include kaolin, serpentine and the like. The smectite group includes saponite, hectorite, sauconite, montmorillonite, beidellite, nontronite, and stephensite.The vermiculite group includes trioctahedral vermiculite, dioctahedral vermiculite, and the mica group. Examples include phlogopite, biotite, lepidrite, muscobite, paragonite, chlorite, margarite, teniolite, tetrasilicic mica, illite, and sericite. These phyllosilicates may be produced naturally or synthesized by a hydrothermal method, a melting method, a solid phase method or the like.

The organic compound for converting the layered silicate into an organophilic compound is not particularly limited as long as it is an organic compound having basicity. Examples thereof include a primary amine, a secondary amine and a tertiary amine. Examples include amine compounds such as amines and quaternary ammonium ions, amino acids and derivatives thereof, nitrogen-containing heterocyclic compounds, and phosphine compounds. Furthermore, compounds such as salts of these compounds with acids and organic cations derived from the salts can also be suitably used.

Specifically, primary amines such as octylamine, laurylamine, tetradecylamine, hexadecylamine, stearylamine, oleylamine, allylamine, benzylamine, aniline, dilaurylamine, ditetradecylamine, Secondary amines such as hexadecylamine, distearylamine, N-methylaniline, dimethyloctylamine, dimethyldecylamine,
Dimethyl lauryl amine, dimethyl myristyl amine,
Dimethyl palmitylamine, dimethylstearylamine, dilauryl monomethylamine, tributylamine,
3 such as trioctylamine, N, N-dimethylaniline
Secondary amines, tetrabutylammonium ion, tetrahexylammonium ion, dihexyldimethylammonium ion, dioctyldimethylammonium ion, hexyltrimethylammonium ion, octyltrimethylammonium ion, dodecyltrimethylammonium ion, tetradecyltrimethylammonium ion, hexadecyltrimethylammonium ion , Stearyl trimethyl ammonium ion, docosenyl trimethyl ammonium ion, cetyl trimethyl ammonium ion, cetyl triethyl ammonium ion, tetradecyl dimethyl benzyl ammonium ion, distearyl dimethyl ammonium ion, stearyl dimethyl benzyl ammonium ion, dioleyl dimethyl ammonium Ions, dodecyl monomethyl diethanol ammonium ion, methyl dipropanolamine lauryl ammonium ion, dimethyl monoethanolamine lauryl ammonium ions, quaternary ammonium ions such as polyoxyethylene dodecyl monomethyl ammonium ion, leucine, cysteine, phenylalanine,
Tyrosine, aspartic acid, glutamic acid, lysine, 6
-Aminohexylcarboxylic acid, 12-aminolaurylcarboxylic acid, N, N-dimethyl-6-aminohexylcarboxylic acid, N, N-dimethyl-10-aminodecylcarboxylic acid, N, N-dimethyl-12-aminolaurylcarboxylic acid Amino acids such as acids and derivatives thereof, pyridine, pyrimidine, pyrrole, imidazole, proline, γ-lactam, histidine, tryptophan, melamine, isocyanuric acid, nitrogen-containing heterocyclic compounds such as melamine cyanurate, and phosphines such as triphenylphosphine Compounds,
Salts of the above compounds and acids, organic cations derived from salts, and the like are included. These layered silicates can be used alone or in combination of two or more of the organic compounds for converting the layered silicate into an organophilic substance.

The acid used to form the salts in the above compounds includes, for example, Lewis acids. Lewis acids are electron pair acceptors, for example, hydrogen acids such as hydrochloric acid and hydrogen sulfide, sulfuric acid, nitric acid, oxo acids such as acetic acid and phosphoric acid, thio acids such as ethyl xanthogenic acid, alkyl halides, acid halides and the like. No.

The organic compound for converting the layered silicate into an organophilic compound is preferably a primary to tertiary amine salt,
Organic cations derived from salts selected from the group consisting of quaternary ammonium salts and amino acid salts, and nitrogen-containing heterocyclic compounds, and more preferably quaternary ammonium ions among organic cations and nitrogen-containing heterocyclic compounds. It is a triazine compound derivative having a positive charge. More specifically, examples of more preferred quaternary ammonium ions include dodecylmonomethyldiethanolammonium ion, distearyldimethylammonium ion, and triazine compound derivatives having a positive charge, melamine, isocyanuric acid, and melamine cyanurate. Organic compounds to be used.

The triazine compound derivative having a positive charge in the present invention is preferably a reaction product of a triazine compound and a Lewis acid and a compound derived from the reaction product.

More specifically, the triazine compound refers to a compound having a triazine ring which is a 6-membered ring containing three nitrogen atoms, and is preferably a 1,3,5-triazine compound, and specifically, Are melamines such as melamine, N-ethylenemelamine, N, N ′, N ″ -triphenylmelamine, cyanuric acid, isocyanuric acid, trimethylcyanurate, tri (n-propyl) cyanurate, tris (n-propyl) Cyanuric acids such as isocyanurate, diethyl cyanurate, N, N'-diethyl isocyanurate, methyl cyanurate, methyl isocyanurate, etc .; and melamine cyanurates comprising an equimolar reaction product of melamines and cyanuric acids are exemplified. The melamine cyanurate compound can be obtained, for example, by mixing an aqueous solution of melamine and an aqueous solution of cyanuric acid and performing a stirring reaction at a temperature of about 90 to 100 ° C.

As a method for obtaining a triazine compound derivative having a positive charge, a method of dissolving the triazine compound in water or alcohol, adding a Lewis acid, stirring and reacting is exemplified. The amount of the Lewis acid to be added is 0.01 to 3 with respect to 1 mol of the triazine compound.
Mol, more preferably 0.1 to 2 mol. The produced triazine-based compound derivative can be used in a solution state as it is, but may be taken out and used. Alternatively, a commercially available product can be used as it is or after being dissolved in a solvent such as water.

There is no particular limitation on the method for obtaining the organoclay composite of the present invention by mixing a layered silicate and an organic compound to obtain an organophilic compound. For example, a method of contacting both the layered silicate and the organic compound via a medium having an affinity, a method of directly mixing and contacting without using a medium, and the like are exemplified. In the method of contacting through a medium, each of them is water,
A method of dispersing in a solvent such as alcohol, homogenizing, mixing while stirring, and removing the solvent is exemplified. Examples of the method of directly mixing include a method in which both are simultaneously placed in a ball mill, a mortar, or the like, and pulverized and co-ground.

In the present invention, the amount of the organic compound in the organoclay composite is 0.1 to 10 equivalents, preferably 0.3, equivalent to the cation exchange capacity (hereinafter referred to as "CEC") of the layered silicate. To 5 equivalents, more preferably 0.5 to 2.
It is in the range of 0 equivalents. When the amount of the organic compound added is 0.1
If the amount is less than the equivalent, dispersion in the aliphatic polyester in the organoclay composite is reduced, and sufficient water vapor barrier properties cannot be exhibited. If the equivalent is 10 equivalents or more, the organic compound becomes excessive with respect to the inorganic component, and the mechanical strength and heat resistance of the hollow molded container may be impaired, and a mold deposit may be generated during molding.

The CEC of the layered silicate differs depending on the type, the place of production, and the composition of the layered silicate, and therefore must be measured in advance. As the measurement of CEC, for example,
Column infiltration method (see: Clay Handbook, 2nd edition, edited by The Clay Society of Japan, pp. 576-577, published by Techniquedo),
Methylene blue adsorption method (Japan Bentonite Industry Association Standard Test Method, JBAS-107-91) and the like. In addition, the amount of the organic compound in the organoclay composite is calculated by measuring the mass loss of the organic substance using a thermogravimetric device such as a differential thermal / thermobalance measurement (TG-DTA) device.

The aliphatic polyester hollow molded container of the present invention comprises a composition comprising 60 to 99.9% by mass of an aliphatic polyester and 40 to 0.1% by mass of an organoclay composite. The content of the clay composite is preferably from 30 to 0.5% by mass, particularly preferably from 20 to 1% by mass.
% By weight is preferred. Organic complex content is 0.1% by mass
If it is less than 1, the effect of improving the water vapor barrier property cannot be expected. On the other hand, if it exceeds 40% by mass, dispersion becomes insufficient, which is not preferable.

The composition for a blow-molded container of the present invention may optionally contain additives commonly used in the art, such as antioxidants, heat stabilizers, ultraviolet inhibitors, lubricants and antistatic agents. , A flame retardant, a crystallization accelerator, a filler, and the like may be added in a range that does not impair the characteristics of the present invention.

Specifically, pt-
Hindered phenolic antioxidants such as butylhydroxytoluene and pt-butylhydroxyanisole; triphenyl phosphite, trilauryl phosphite, trisnonyl phenyl phosphite and the like as heat stabilizers; t-butylphenyl salicylate, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxy-2′-carboxybenzophenone, 2,4,5-trihydroxybutyrophenone and the like; as a lubricant, calcium stearate, zinc stearate, Barium stearate, sodium palmitate, etc .; N, N-bis (hydroxyethyl) alkylamine, alkylamine, alkylallyl sulfonate, alkyl sulfonate, etc. as antistatic agent; hexabroth, as flame retardant Mocyclododecane, tris-
(2,3-dichloropropyl) phosphate, pentabromophenyl allyl ether, etc .; crystallization accelerators such as talc, boron nitrite, polyethylene terephthalate, poly-transcyclohexane dimethanol terephthalate, etc .; inorganic fillers such as calcium carbonate and silica , Titanium oxide, talc, mica, barium sulfate, alumina, etc., as well as organic fillers such as wood flour, husk,
Used paper such as newsprint, various types of starch (including those obtained by changing the structure such as pregelatinized starch), cellulose and the like.

The composition for a hollow molded container of the present invention is obtained by uniformly dispersing and mixing the above-mentioned components using a known mixing device such as an extruder. The mixing temperature is 150 to 200 ° C
The degree is preferred.

The molding method of the container of the present invention includes molding methods such as direct blow molding, accumulator blow molding, injection blow molding, stretch blow molding, multilayer blow molding and the like, particularly cold parison blow molding or hot blow molding. A molding method in which the orientation of the resin is caused as in the stretch hollow molding exemplified by the parison method hollow molding is suitable for improving the water vapor barrier property. These molding methods can be performed using an apparatus known in the art.

[0028]

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 Denshi Co., DSC200) at a heating rate of 10 ° C./min. Melt flow rate (hereinafter “MFR”)
That. ) Conforms to JIS K7210 and has a temperature of 190.
It measured on conditions of ° C and a load of 21.18N.

Weight average molecular weight (hereinafter referred to as "Mw")
Was measured under the following conditions using gel permeation chromatography (Showex GPC, Shodex GPC System-11).・ Solvent: Hexafluoroisopropyl alcohol solution containing 15 mmol / l ammonium acetate ・ Resin concentration: 0.1% by mass ・ Calibration curve: PMMA standard sample (manufactured by Showa Denko KK, Sh
Odex Standard M-75)

The water vapor barrier property is determined by adding 450 ml of distilled water to a molded cylindrical bottle (diameter 60 mm, height 190 mm, capacity 500 ml, average thickness 1.0 mm), sealing with the same resin as the cylindrical bottle, and then screw capping. Was stored for 10 days at a temperature of 40 ° C. and a humidity of 20%, and evaluated by calculating the water vapor transmission rate from the measurement of the mass loss.

The biodegradability was determined by burying a film cut into 10 cm squares at a depth of about 10 cm from the ground surface next to the tennis court in Showa Denko K.K. The weight loss of the components was measured, and the reduction ratio was evaluated in the following four steps.

◎ ８０ 80% or more 50 to less than 80% 10 to less than 50% × 未 満 less than 10%

The following four types were used as aliphatic polyesters.・ Polyester A bionore # 1001 / # 1903
= 80/20 Bionore # 1001 (manufactured by Showa Polymer) Melting point: 113 ° C., MFR: 1.4 g / 10 min Mw: 220,000 Bionore # 1903 (manufactured by Showa Polymer) Melting point: 113 ° C., MFR: 3.7 g Polyester B Bionole # 3001 (manufactured by Showa Polymer Co., Ltd.) Melting point: 95 ° C., MFR: 1.2 g / 10 minutes Mw: 240,000 Polyester C Biopol D-611G (manufactured by Monsanto) Melting point: 136 ° C, MFR; 45 g / 10 min Mw; 260,000 ・ Polyester D Praxel H-7 (manufactured by Daicel Chemical Co., Ltd.) Melting point: 60 ° C, MFR: 3.5 g / 10 min Mw;

As the layered silicate, a fluorine-type tetrasilicic mica (manufactured by Corp Chemical: Somasif ME-10)
0, ion exchange capacity: 107 meq / 100 g) (hereinafter referred to as “mica”). Dodecylmonomethyldiethanolammonium chloride (manufactured by Lion Akzo; Esocard C-12) (hereinafter referred to as "cation A") and distearyldimethylammonium chloride (manufactured by Kao Corporation; Cotamine D86P) as organic cations
(Hereinafter referred to as “cation B”).

Production Example of Organic Clay Complex 300 g of mica was added to 3000 ml 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 prepared by dissolving 140 g of cation A in 2000 ml of distilled water at a temperature of 60 ° C. was added to the above suspension, and 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. After drying with hot air, coarse grinding with a water-cooled wheelie mill, fine grinding with a jet mill grinder (manufactured by Hosokawa Micron Co., Ltd.), and classification of only those having an average particle size of 5 μm or less to differentiate the complex (hereinafter referred to as “composite Body A ").
The average particle size of the obtained composite A was 1.8 μm.

Further, 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 μm.

Production method of triazine-modified layered silicate Complex C: 200 g of mica was mixed in 4000 ml of distilled water to sufficiently swell. This dispersion was heated to 60 ° C., and an aqueous solution of melamine hydrochloride at 60 ° C. was added in an amount of 1.0 equivalent to the ion exchange capacity of the layered silicate, followed by sufficient stirring to perform an ion exchange reaction. This suspension is filtered, washed,
The filtration was repeated, dried and pulverized to obtain a triazine-modified layered silicate. The content of the cyanuric acid derivative in the obtained triazine-modified layered silicate was 10% by mass.

Complex D: Mica 2 in the same manner as above
00g, cyanuric acid (160 mmol), hydrochloric acid (160
mmol) to prepare a triazine-modified layered silicate. The content of the cyanuric acid derivative in the obtained triazine-modified layered silicate was 15%. Example of production method of polyester resin composition Aliphatic polyester and organoclay composite are screwed with a screw diameter of 38 mm and are coaxially twin-screw extruders (manufactured by Toshiba Machine Co., TEM-
(37BS, vent type) to obtain a composition.

Example of hollow molding (direct hollow molding) Screw diameter 50 mm, L / D
= 26, CR = 3, average product thickness 0.8
A cylindrical bottle having a capacity of 500 mm and a capacity of 500 ml was formed. Molding resin temperature is 190 ° C, mold temperature is 20 ° C, blow pressure is 0.5
MPa and the cooling time were 15 seconds.

(Cold parison method hollow molding) diameter 20
mm, length 50mm, thickness 3.4mm bottomed parison is formed by injection molding at an injection temperature of 140 ° C, an injection speed of 10mm / s, a supplementary pressure of 4.5MPa, a mold temperature of 20 ° C, and a cooling time of 20 seconds. did. The bottomed parison foam was reheated from room temperature to a stretching temperature of 79 ° C. in about 1 minute with an infrared heater, stabilized for 30 seconds, and then pressurized by air pressure to produce a storage pressure of 0.6 MPa and a storage time of 0.1.
Second, primary blow pressure 0.4 MPa, primary blow time 1.5
A second blow pressure of 2 MPa, a second blow time of 3.0 seconds, and a container having a capacity of 500 ml by a stretch blow molding method were prepared.

(Hot parison hollow molding) 20 m in diameter
m, 50mm long, 3.4mm thick bottomed parison,
Injection temperature 140 ° C, injection speed 10mm / s, supplementary pressure 4.5
After injection molding at a pressure of 1 MPa, the preform is cooled to a uniform temperature of 80 ° C., and then the longitudinal stretching rod speed is adjusted to 0.
A 15 ml / s primary blow pressure of 0.5 MPa, a primary blow time of 0.3 second, a secondary blow pressure of 2.5 MPa, and a secondary blow time of 7 seconds were used to prepare a 500 ml container by a stretch blow molding method.

Examples 1 to 6, 11 to 14 and Comparative Examples 1 to 4 A composition obtained by kneading an aliphatic polyester and an organoclay composite was vacuum-dried at a temperature of 50 ° C. for 24 hours and then subjected to direct blow molding. A container having a capacity of 500 ml by a hollow molding method was prepared. The water vapor transmission rate and biodegradability of the obtained container were measured. Table 1 shows the types and amounts of the polyesters in the composition and the measurement results. Examples 7 and 8 Volume 5 obtained by the stretch blow molding method of the cold parison method
The water vapor transmission rate and biodegradability of the 00 ml container were measured.
Table 1 shows the types and amounts of polyesters in the composition and the measurement results.
Shown in Examples 9 and 10 Capacities of 50 obtained by the stretch blow molding method of the hot parison method
The water vapor transmission rate and biodegradability of the 0 ml container were measured. Table 1 shows the types and amounts of the polyesters in the composition and the measurement results.

[0044]

[Table 1]

[0045]

EFFECT OF THE INVENTION The aliphatic polyester hollow molded container of the present invention is excellent in molding stability, water vapor barrier property and biodegradability, so that it can be used as a bottle for detergents, cosmetics, beverages and the like in various fields. Available and useful in the field.

Continued on the front page F term (reference) 3E067 AA03 AB26 AB81 AB99 BA03A BB14A BB22A CA05 EE32 4F208 AA24 AB19 LA01 LA02 LA04 LB01 LG01 LJ01 4J002 CF031 CF181 CF191 DJ006 DJ056 FA016 FB086 FD010 FD200 FD100 FD070 FD070 FD070 FD070 FD070 FD070 FD070 FD070 FD070 FD070 FD070 FD070 FD100

Claims (6)

[Claims] (1) aliphatic polyester 60 to 99.9 (a)
(B) a hollow molded container made of an aliphatic polyester, comprising 40 to 0.1% by mass of an organoclay composite. 2. An aliphatic polyester having a melting point of 50-19.
The hollow molded container made of an aliphatic polyester according to claim 1, which has a temperature of 0 ° C and a weight average molecular weight of 50,000 or more. 3. The aliphatic polyester hollow molded container according to claim 1, wherein the aliphatic polyester is a polyester made of a raw material containing glycol and aliphatic dicarboxylic acid as main components. 4. The organic clay complex contains an organic cation derived from at least one salt selected from the group consisting of primary to tertiary amine salts, quaternary ammonium salts and amino acid salts. The hollow molded container made of the aliphatic polyester according to claim 1. 5. The aliphatic polyester hollow molded container according to claim 1, wherein the organoclay composite contains a triazine compound derivative having a positive charge. 6. The method for forming a hollow molded container made of an aliphatic polyester according to claim 1, wherein the stretched hollow molding is performed by cold parison hollow molding or hot parison hollow molding.