JP4634235B2 - Biodegradable resin composition and film - Google Patents

Description

The present invention relates to a biodegradable resin composition and a film (including those referred to as sheets in the present invention) having excellent transparency and antifogging properties, and more specifically, biodegradability suitable for agriculture or food packaging materials. It relates to a resin composition and fill beam.

  In today's daily life, plastics (synthetic resins) such as polyethylene, polystyrene, polypropylene, and polyvinyl chloride are used in a wide variety of fields such as food packaging, building materials, and home appliances, and are indispensable for daily life. It has become something that can not be.

  The most important characteristic of plastic is its durability, but when it is used as waste after its mission, its good durability is inferior to natural degradation and affects biological systems. It has a negative aspect that causes environmental destruction.

Biodegradable plastics (biodegradable resin compositions) are attracting attention in order to overcome such drawbacks of plastics. Recycling of plastic products has been regulated by the growing awareness of environmental issues in recent years, and so-called biodegradable plastics that can be easily decomposed in the environment along with recycling and reuse have attracted attention. Is poured. And agricultural fill-time in particular be used in the environment as its applications, use in food packaging fill-time high safety is required is expected.

Although as the agricultural film in such agricultural mulch film has begun application of biodegradable plastics, Oite to fill beam such as agricultural houses and dressings, mechanical properties, transparency, weather resistance and anti-fogging Resins that are satisfactory in performance and other properties are being pursued.
For improving flexibility and impact resistance, a method for producing a biodegradable agricultural film in which polylactic acid and biodegradable polyester are blended at a specific ratio is known (for example, see Patent Documents 1 and 2). However, its transparency is low and it cannot be used as an agricultural house or covering material.

In applications such as agricultural houses and covering materials, it is possible to add a dripping agent or an antifogging agent to prevent damage to the production crops due to the impairing of sunlight due to water droplets adhering to the plastic surface and falling of water droplets. Usually done. For the purpose of improving transparency and antifogging property, a method of blending a small amount of polybutylene terephthalate resin with a biodegradable aliphatic aromatic polyester resin is known (for example, see Patent Document 3). In the film containing the antifogging agent described in (1), the antifogging agent bleeds out vigorously, and the film becomes white and turbid after several days of film production, which is difficult to use in practice. Further, it is known to use a nonionic surfactant in combination as a lubricant and an antifogging agent in a polylactic acid film (for example, see Patent Document 4), but satisfactory antifogging properties are not obtained.
JP 2004-147613 A JP 2003-105183 A JP 2004-352799 A JP-A-9-286908

The specific anti-fogging agents according to the present invention, by incorporating a specific biodegradable polyester resin, there is no inhibition of transparency due to bleeding out of the anti-fogging agents, excellent initial anti-fogging property and anti-fogging sustainability transparent, flexible biodegradable resin composition and agricultural film obtained by molding it, it is possible to supply a fill arm suitable for food packaging.

An object of the present invention is a biodegradable resin with low environmental impact, having transparency, flexibility and weather resistance, having no hindering of transparency due to bleed-out of the antifogging agent over time and having excellent antifogging durability. composition and the agricultural, is to provide a fill-time which is suitable for food packaging.

The present invention for solving the above problems has the following configuration.
1. An ester of an alcohol selected from sorbitol, sorbitan, and polyglycerin as an antifogging agent (including dehydrated condensed alcohol and an alkylene oxide adduct of a polyhydric alcohol) and a fatty acid with respect to 100 parts by mass of the biodegradable polyester resin. In the biodegradable resin composition containing 0.1 to 5.0 parts by mass and 0.05 to 2.5 parts by mass of the sulfonate surfactant ,
The biodegradable polyester resin is a polyester obtained by polycondensing a diol containing at least one of ethylene glycol and 1,4-butanediol with a dicarboxylic acid containing at least one of terephthalic acid and adipic acid. ,and,
The esterification rate is 25 to 75% when the ratio of the hydroxyl group esterified with fatty acid in the hydroxyl group of the polyhydric alcohol in the antifogging agent is defined as the esterification rate. A biodegradable resin composition.

2. Phil beam, characterized in that molded from the biodegradable resin composition according to the 1.
As a reference invention of the present invention, one in which the biodegradable polyester resin is a lactic acid-based polyester can be mentioned.

The present invention will be described in more detail.
The present invention is Ru der those directed to biodegradable polyester resin. The structure of the polyester can be broadly classified into those in which diols and dicarboxylic acids are alternately polymerized as monomers and polymers of hydroxycarboxylic acids. Polyester monomer diols that can be used in the present invention include ethylene glycol, propylene glycol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, neopentyl glycol, and 1,6-hexanediol. 1,4-benzenedimethanol, and polymers thereof. Examples of the dicarboxylic acid include succinic acid, oxalic acid, malonic acid, maleic acid, fumaric acid, adipic acid, azelaic acid, sebacic acid, undecanoic acid, dodecanedioic acid, isophthalic acid, terephthalic acid and the like. Examples of the hydroxycarboxylic acid include L-lactic acid, D-lactic acid, glycolic acid, 3-hydroxybutyric acid, 4-hydroxybutyric acid, 3-hydroxyvaleric acid, 4-hydroxyvaleric acid, and 6-hydroxycaproic acid. These can be used alone or in combination of two or more.

These monomers can be selected without particular limitation as long as they have biodegradability. Since the present invention aims to prevent fogging due to adhesion of water droplets during use, a highly transparent polyester is preferred. Containing at least one of ethylene glycol and 1,4-butanediol as diol, and at least one of terephthalic acid and adipic acid as dicarboxylic acid, and polycondensed them, mechanical properties, transparency, biodegradation It has a good balance of properties and is used in the present invention.

The biodegradable polyester resin according to the reference invention of the present invention may be a lactic acid polyester or a polylactic acid.

The polylactic acid resin used does not ask | require the polymerization degree or quality. The lactic acid monomer used in the polylactic acid resin can be used without particular limitation even if it is D-form or L-form. Further, not only a polymer composed only of L-lactic acid or D-lactic acid, but also a copolymer such as glycolic acid, ε-caprolactone, trimethylene carbonate or polyethylene glycol may be used in combination. In addition, other biodegradable polymers such as cellulose acetate, polycaprolactone, polybutylene succinate, polyhydroxybutyrate and valerate copolymer, chitin, chitosan or starch can be used as long as the physical properties of the polylactic acid resin are not impaired. You may mix | blend.
In the reference invention of the present invention, copolymers other than those described above may be used in combination as long as the object of the present invention is not impaired. For example, impact resistance may be enhanced by mixing an ethylene / glycidyl methacrylate copolymer in a ratio of 4: 1 to polylactic acid.

There is no restriction | limiting in particular as a manufacturing method of the biodegradable polyester resin used for this invention, It can manufacture using a well-known method. For example, direct direct polycondensation of polycondensation or hydroxycarboxylic acids of the diol and dicarboxylic acid, ring-opening polymerization using a toroid or a cyclic dimer of hydroxycarboxylic acid. During polymerization, a branched chain may be introduced by copolymerizing a polyfunctional monomer such as glycerin, polyglycerin, pentaerythritol, citric acid, tartaric acid or malic acid. Further, isocyanate compounds, epoxy compounds, aziridine compounds, carbodiimide compounds, oxazoline compounds, azo compounds, polyvalent metal compounds, polyfunctional phosphates, phosphites, and the like may be used as chain extenders.

Fogging agents used in the present invention is more constructed on a combination of polyhydric alcohol and consists fatty acid ester and sulfonate-based surfactant. Examples of the polyhydric alcohol that can be used for an ester composed of a polyhydric alcohol and a fatty acid include ethylene glycol, propylene glycol, isosorbide, glycerin, trimethylolpropane, erythritol, pentaerythritol, sorbitan, xylitol, sorbitol, and sucrose. In addition, dehydration condensation alcohols of these polyhydric alcohols can also be used. Examples of the dehydrated condensed alcohol include polyglycerin and polypentaerythritol.

  Furthermore, alcohols obtained by adding alkylene oxide to these polyhydric alcohols can also be used. Two or more kinds of these polyhydric alcohols may be used. Among these, sorbitol, sorbitan, polyglycerin, sorbitol ethylene oxide adduct, sorbitan ethylene oxide adduct, sorbitan propylene oxide adduct, polyglycerin ethylene oxide adduct, etc. and esters of fatty acids are initially antifogging and persistent antifogging. It is excellent in safety, has little hindering of transparency, and has high safety, which is preferable.

  Fatty acids that can be used in esters composed of polyhydric alcohols and fatty acids are not particularly limited, but are saturated fatty acids such as caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, behenic acid, oleic acid, linoleic acid Unsaturated fatty acids such as linolenic acid and erucic acid can be used. As these fatty acids, two or more kinds of mixed fatty acids may be used.

An ester composed of a polyhydric alcohol and a fatty acid can be produced by a known ester reaction. For example, it can be produced by a direct esterification reaction between a polyhydric alcohol and a fatty acid or a transesterification reaction between a polyhydric alcohol and an oil. In the present invention, it is occupying in the hydroxyl group of the polyhydric alcohol of the raw material, when the percentage of esterified hydroxyl groups and esterification ratio by fatty acids, esterification rate Ru der than 75% to 25%. When the esterification rate is less than this range, the compatibility with the resin is low and bleeding tends to occur. Moreover, when the esterification rate exceeds this range, the hydrophilicity becomes low and antifogging properties are hardly exhibited.

  Examples of the sulfonate surfactant used in the present invention include sodium dodecylbenzenesulfonate, calcium dodecylbenzenesulfonate, sodium alkylnaphthalenesulfonate, sodium α-olefinsulfonate, sodium dioctylsulfosuccinate, sodium dihexylsulfosuccinate. , Sodium ditridecyl sulfosuccinate, disodium lauryl sulfosuccinate, sodium linear alkylbenzene sulfonate, sodium alkyl sulfonate, and the like. Of these, sodium alkyl sulfonate is particularly preferable from the viewpoint of achieving the object of the present invention.

In this invention, the compounding quantity with respect to biodegradable polyester-type resin of ester which consists of a polyhydric alcohol and a fatty acid is 0.1-5 . It is 0 mass part, Preferably it is the range of 0.5-3 mass part. When below this range, the target performance of the present invention is insufficient, and when above this range, the transparency of the molded product is impaired, or bleeding of the antifogging agent is observed.

  In this invention, the compounding quantity with respect to biodegradable polyester-type resin of a sulfonate surfactant is in the range of 0.05-2.5 mass parts with respect to 100 mass parts of resin. When below this range, the target performance of the present invention is insufficient. When exceeding this range, the physical properties and transparency of the molded product are impaired, and bleeding of the antifogging agent is observed.

  The biodegradable resin composition of the present invention may be used in combination with additives such as stabilizers, plasticizers, antistatic agents, antioxidants, lubricants, slip agents, antifogging agents, and the like. Can be used in combination as long as the effects of the present invention are not impaired.

The biodegradable resin composition of the present invention can be compounded with additives such as resin and antifogging agent using an extruder, a Banbury mixer, etc., which are used for ordinary plastic compounding. In the case of polymer blending, a twin screw extruder is preferred. Moreover, you may add an additive to a biodegradable resin composition previously by the masterbatch method which produces the resin composition which contains an additive in high concentration. A compound or masterbatch was prepared by blending to a predetermined concentration, T die and molded into by Ri Fi Lum like inflation. The film may be either stretched or unstretched.

Hereinafter, the present invention will be described in detail with reference to examples, but the embodiments of the present invention are not limited thereto.
The evaluation method for each evaluation item will be described below.
Evaluation is performed by putting water at the temperature shown below into a water tank, covering the prepared film with a 100 × 100 mm window test box having an inclination of 30 degrees for evaluation, and stopping with cellophane tape. The anti-fogging property, film bleeding and film transparency were evaluated over time.

<Anti-fogging property>
◎: No water droplets ○: Some water droplets △: Small water droplets are conspicuous ×: Full surface fogging <Film bleed>
◎: No bleed ×: Many bleed <Transparency of film>
◎: The bottom of the aquarium is clearly visible through the film. ×: The film is cloudy and the bottom of the aquarium appears hazy.

<Test sample>
Resin 1
Polybutylene terephthalate adipate "Eflex" manufactured by BASF
Resin 2 (reference invention)
Polylactic acid "Lacia H-440" manufactured by Mitsui Chemicals, Inc.
Polyhydric alcohol fatty acid ester 1
Sorbitan monopalmitate "Rikemar SP-250" produced by Riken Vitamin, approx. 25% esterification rate
Polyhydric alcohol fatty acid ester 2
Sorbitan 20EO triolate "Rikemar O-852" esterification rate, about 75%, manufactured by Riken Vitamin
Polyhydric alcohol fatty acid ester 3
Diglycerin monostearate "Riquemar S-71-D" produced by Riken Vitamin, approx. 30% esterification rate
Polyhydric alcohol fatty acid ester 4
Diglycerin monooleate “Riquemar O-71-DE” manufactured by Riken Vitamin, approx. 30% esterification rate
Polyhydric alcohol fatty acid ester 5
Decaglycerin dedekarate esterification rate of about 95%,
Production Example 95.4 g of decaglycerin and 400 g of oleic acid were charged into a 500 ml four-necked flask equipped with a water separator, thermometer, nitrogen inlet tube and stirring rod, and the acid value was increased at 230 ° C. while blowing nitrogen without using a catalyst. The esterification reaction was carried out for 20 hours until it became 10 or less. After completion of the reaction, the mixture was cooled to obtain 463 g of a pale yellow liquid.
Polyhydric alcohol fatty acid ester 6
Decaglycerin monolaurate “Poem J-0021” manufactured by Riken Vitamin Co. Esterification rate: approx. 8%
Sulfonate surfactant 1
Sodium alkyl sulfonate "Anstex HT-100" manufactured by Toho Chemical Co., Ltd.
Sulfonate surfactant 2
Sodium dioctylsulfosuccinate "Aerosol OT" manufactured by Wako Pure Chemical Industries

[Examples 1-6, Comparative Examples 1-5, Reference Examples 1-2]
In order to prevent a decrease in molecular weight due to hydrolysis, the resin 1 is subjected to a heat drying treatment at 80 ° C. for 5 hours to remove moisture, and then, for 100 parts by mass of the resin 1, for each of Examples and Comparative Examples, A predetermined amount of the test sample (described in Table 2) was blended, and extruded pellets were prepared at 160 ° C. using a twin screw extruder. Using this pellet, a film having a thickness of 80 μm was prepared by a single screw extruder equipped with a T die, and the following evaluations were performed.

  The evaluation results are shown in Table 3 (high temperature anti-fogging property) and Table 4 (low temperature anti-fogging property).

[ Reference Invention Examples 1-6 , Comparative Examples 6-10, Reference Examples 3-4]
In order to prevent the molecular weight from being reduced due to hydrolysis, the resin 2 was subjected to a heat drying treatment at 80 ° C. for 5 hours to remove moisture, and then 100 parts by mass of the resin 2 for each Reference Invention Example and Comparative Example, Predetermined amounts (described in Table 5) of the following test samples were blended, and extruded pellets were prepared at 180 ° C. using a twin screw extruder. Using this pellet, a film having a thickness of 80 μm was prepared by a single screw extruder equipped with a T die, and the following evaluations were performed.

  The evaluation results are shown in Table 6 (high temperature anti-fogging property) and Table 7 (low temperature anti-fogging property).

With antifog agent biodegradable polyester resin added of the present invention, agricultural with by molding a fill arm, long term stable antifogging even at high temperatures even at a low temperature, transparency, flexibility use, it is possible to produce a fill-time which is suitable for food packaging material.

Claims (2)

An ester of an alcohol selected from sorbitol, sorbitan, and polyglycerin as an antifogging agent (including dehydrated condensed alcohol and an alkylene oxide adduct of a polyhydric alcohol) and a fatty acid with respect to 100 parts by mass of the biodegradable polyester resin. In the biodegradable resin composition containing 0.1 to 5.0 parts by mass and 0.05 to 2.5 parts by mass of the sulfonate surfactant ,
The biodegradable polyester resin is a polyester obtained by polycondensing a diol containing at least one of ethylene glycol and 1,4-butanediol with a dicarboxylic acid containing at least one of terephthalic acid and adipic acid. ,and,
The esterification rate is 25 to 75% when the ratio of the hydroxyl group esterified with fatty acid in the hydroxyl group of the polyhydric alcohol in the antifogging agent is defined as the esterification rate. A biodegradable resin composition. Phil beam, characterized in that molded from the biodegradable resin composition of claim 1.