JP2006055029A - Agricultural resin composition and agricultural material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain an agricultural resin composition excellent as an anti-fog agent comprising a polyester resin, in particular, a biodegradable aliphatic polyester resin, and having durability of antifogging properties, high security and slight burden on the environment; and to provide an agricultural material obtained by using the composition. <P>SOLUTION: The agricultural resin composition consists mainly of the aliphatic polyester-based resin comprising a diol and a dicarboxylic acid. The composition contains 0.1-5 pts.wt of triglycerol fatty acid ester having 4-7 HLB and consisting mainly of saturated fatty acid where a constituent fatty acid comprises 12-22C saturated fatty acid, based on 100 pts.wt of the aliphatic polyester-based resin, based on 100 pts.wt. of the aliphatic polyester resin. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an agricultural resin composition and an agricultural material, and more particularly, to an aliphatic polyester resin composition and an agricultural resin composition and an agricultural material excellent in antifogging properties.

  In today's daily life, plastic products 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.

  The most important characteristic of plastic is its durability, but when it becomes 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 are attracting attention to overcome such disadvantages 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. In particular, it is expected to be used in agricultural materials used in the environment (for example, sheets, films, and other molded articles used for root vegetable growing houses).

  However, in general, plastics have a nature of repelling water, that is, hydrophobic, so that when they are exposed to water vapor, they become water droplets and become cloudy. In order to prevent this, it is necessary to make the film surface hydrophilic by using an antifogging agent (for example, see Non-Patent Document 1).

  There are two types of plastics used as an antifogging agent: a coating type and a kneading type. Conventionally, a coating type resin is often used as an antifogging agent for polyester resins. As an example, there is one having an inorganic colloidal gel as a main component (for example, see Patent Document 1). However, it is necessary to apply an antifogging agent after processing agricultural materials, which increases the number of manufacturing processes and is inefficient. Further, the coating film of the antifogging agent may peel off or flow, and it is difficult to stably maintain the antifogging property over a long period of time.

  In general, a nonionic surfactant is often used as a kneading-type antifogging agent in an agricultural resin composition. Nonionic surfactants are characterized by low transparency inhibition. For example, sorbitan fatty acid esters such as sorbitan monostearate, sorbitan monooleate and sorbitan monopalmitate, glycerin fatty acid esters such as glycerin monostearate and glycerin monooleate, polyethylene glycols such as polyethylene glycol monooleate and polyethylene glycol monostearate And those obtained by adding ethylene oxide, propylene oxide or the like to them.

However, as for the kneading type antifogging agent, few polyester resins are effective. In particular, in a biodegradable resin, the composition of an excellent kneading type antifogging agent is not known (see, for example, Patent Document 2).
Japanese Patent Laid-Open No. 10-86307 JP 2001-136847 A “Wet Technology Handbook” Techno System, Inc., October 25, 2001, p415-427

  An object of the present invention is an agricultural resin composition which is excellent as an antifogging agent for polyester resins, particularly aliphatic polyester resins having biodegradability, has antifogging durability, is safe and has a low environmental impact. And providing agricultural materials using the same.

The present invention for solving the above problems has the following configuration.
1. In an agricultural resin composition mainly composed of an aliphatic polyester resin comprising a diol and a dicarboxylic acid, a saturated fatty acid having a HLB of 4 to 7 and a constituent fatty acid of C12 to 22 per 100 parts by weight of the aliphatic polyester resin An agricultural resin composition comprising 0.1 to 5 parts by mass of a triglycerin fatty acid ester mainly containing a fatty acid.

2. 2. The agricultural resin composition according to 1 above, wherein the diol contains at least one of ethylene glycol and 1,4-butanediol, and the dicarboxylic acid contains at least one of succinic acid and adipic acid. object.

3. Agricultural material formed as an agricultural film, sheet, or other molded article using the agricultural resin composition according to 1 or 2 above.

  By containing the specific antifogging agent of the present invention in an amount of 0.1 to 5 parts by weight per 100 parts by weight of the aliphatic polyester resin, it is environmentally friendly and excellent in antifogging property, and in particular, it has excellent antifogging durability and flexibility. It becomes possible to supply the agricultural resin composition and agricultural material which can shape | mold an agricultural material.

The present invention will be described in more detail.
The present invention is directed to an aliphatic polyester resin. Regardless of the degree of polymerization or quality of the aliphatic polyester resin used, any known polymer containing a diol and a dicarboxylic acid can be used without limitation. The diol and dicarboxylic acid to be used may be a copolymer using a plurality of types. In addition, other biodegradable polymers such as polylactic acid, cellulose acetate, polycaprolactone, copolymers of polyhydroxybutyrate and valerate, chitin, chitosan or starch can be used as long as the physical properties of the aliphatic polyester resin are not impaired. You may mix | blend.

  Examples of the diol in the present invention include ethylene glycol, polyethylene glycol, propylene glycol, butylene glycol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol and the like. Examples of the dicarboxylic acid include succinic acid, adipic acid, azelaic acid, sebacic acid, dodecanedioic acid, maleic acid, and fumaric acid. Polymerizing polyhydric carboxylic acids such as malic acid, tartaric acid and citric acid and polyhydric alcohols such as glycerin, diglycerin, polyglycerin, trimethylolpropane, pentaerythritol and dipentaerythritol within a range not impairing the performance of the present invention. Also good. In addition, aromatic diols such as bisphenol A and aromatic dicarboxylic acids such as isophthalic acid and terephthalic acid may be copolymerized. Further, hydroxycarboxylic acids such as lactic acid, glycolic acid, 蛛 | caprolactone and 3-hydroxybutanoic acid may be copolymerized. Moreover, an isocyanate compound, an epoxy compound, an aziridine compound, an oxazoline compound, an azo compound, a polyvalent metal compound, a polyfunctional phosphate ester, a phosphite ester, or the like may be used as a chain extender.

  Of the aliphatic polyester resins, biodegradable polyester resins are preferred because they have less environmental impact. In addition, a polyester having a low glass transition temperature is preferable because it easily exhibits antifogging properties. Examples of such biodegradable resins include aliphatic polyesters mainly composed of 1,4-butanediol and succinic acid. Aliphatic polyesters containing ethylene glycol or 1,4-butanediol in the diol and succinic acid or adipic acid in the dicarboxylic acid are preferable because they are highly biodegradable and easily develop antifogging properties.

  The triglycerin fatty acid ester used in the present invention is obtained by an esterification reaction of triglycerin and a fatty acid, but the production method is not particularly limited as long as the requirements of the present invention are satisfied.

  The triglycerin fatty acid ester used in the present invention is an ester of triglycerin, and those having a degree of polymerization of glycerin exceeding 3 have poor compatibility with aliphatic polyester resins as the molecular weight increases, and bleed. Therefore, since the effect of anti-fogging durability is reduced, it is excluded from the present invention.

  The HLB of the triglycerin fatty acid ester used in the present invention is 4-7. When HLB is smaller than 4, there are many bleeds, and when HLB is larger than 7, it takes time until the effect is manifested after kneading into an aliphatic polyester resin. In addition, HLB is calculated | required by a following formula.

HLB = 20 × (1-S / A)
S: Saponification value of ester A: Neutralization value of fatty acid

  The esterification rate of the triglycerin fatty acid ester used in the present invention may be any as long as it is within the above-mentioned HLB range, but is preferably a monoester or diester as a main component.

  Table 1 below shows the HLB when the esterification degree of various fatty acid esters of triglycerin is changed.

  When the HLB is in the range of 4 to 7, the degree of esterification varies depending on the fatty acid species constituting the ester. It becomes the range.

  As the fatty acid constituting the triglycerin fatty acid ester used in the present invention, a saturated fatty acid from lauric acid having 12 carbon atoms to behenic acid having 22 carbon atoms is preferable. In particular, those having a carbon number of C16-18 are preferred in terms of the effect of antifogging sustainability.

  Agricultural materials obtained by molding the agricultural resin composition of the present invention are often used under conditions from low to high temperatures, such as agricultural houses, and low-temperature antifogging properties and high-temperature antifogging as antifogging agents. Sexuality is required. In addition, since the use period is long and it is used for several years, the antifogging agent itself generally has a melting point of room temperature or higher in order to develop a long-lasting effect.

  In agricultural material applications obtained by molding the agricultural resin composition of the present invention, the desired antifogging property is not good for fatty acid esters having less than 12 carbon atoms, and good low temperature is desired for fatty acid esters having more than C22 carbon atoms. Antifogging effect cannot be obtained.

  In the present invention, the blending amount of the antifogging agent with respect to the aliphatic polyester resin is preferably 0.1 to 5 parts by weight, more preferably 0.2 to 3 parts by weight with respect to 100 parts by weight of the aliphatic polyester resin. . When below this range, the target performance of the present invention is insufficient. When exceeding this range, the physical properties of the molded article are impaired, or bleeding of the antifogging agent is observed.

  In the present invention, other anti-fogging agents can be used in combination with the aliphatic polyester-based resin as long as the effects of the invention are not impaired. Although there is no restriction | limiting in particular as another antifogging agent, For example, you may use sorbitan fatty acid ester and glycerol fatty acid ester together.

  The agricultural resin composition of the present invention can be subjected to thermoforming such as extrusion and injection using an extruder, an injection molding machine or the like used for molding ordinary plastics. The molding temperature is preferably 110 to 200 ° C. In the case of polymer blending, a twin screw extruder is preferred. The agricultural resin composition melted in the extruder is formed into a sheet, film, or other molded article by T-die, inflation, or the like. The film may be either stretched or unstretched. Further, an injection molded product can be molded using an injection molding machine or the like and used as the agricultural material of the present invention.

  In the case where the agricultural resin composition of the present invention is formed into a film, excellent antifogging properties can be imparted to a film made of another resin by multilayering (laminating) the film. For example, it is difficult to impart antifogging properties to a polylactic acid resin alone with a kneading type antifogging agent alone, but when the resin layer of the present invention is used as an intermediate layer to form a multilayer film with a polylactic acid layer An agricultural film imparted with an antifogging property can be produced without impairing the biodegradability that is a characteristic of polylactic acid.

  These agricultural resin compositions may be used in combination with stabilizers, antistatic agents, antioxidants, lubricants, slip agents, antifogging agents, and the like. These can be used without limitation, and these can be contained within a range not inhibiting the effect of the antifogging agent of the present invention.

  Hereinafter, the present invention will be described in detail with reference to examples, but the embodiments of the present invention are not limited thereto.

  In the evaluation of this example, in order to prevent the molecular weight of the aliphatic polyester resin from decreasing due to hydrolysis, heat treatment was performed at 80 ° C. for 5 hours to remove moisture, and then the aliphatic polyester resin was applied to the aliphatic polyester resin. For each of the Examples and Comparative Examples, a predetermined amount (described in Table 3) of the following test sample was blended, and extruded pellets were prepared at 140 ° C. using a twin screw extruder. Using these pellets, a film was prepared by a single screw extruder and evaluated for anti-fogging.

Evaluation of antifogging property was carried out by putting water at a temperature shown below into a water tank, covering the created 100 × 100 mm windowed test box with a film with a cellophane tape, and evaluating antifogging property under the following conditions. .
<Evaluation conditions>

<Evaluation criteria for anti-fogging properties>
◎: No water droplets ○ +: There are very few water droplets ○: Some water droplets ○-: Large water droplets adhere to one side △ +: Small water droplets are changing to large water droplets △: Small water droplets are noticeable △ -: Many small water drops ×: Fully cloudy

<Bleed of film (evaluated on the 15th day after film formation at room temperature)>
◎: No bleed ×: With bleed

Test sample resin 1 Aliphatic polyester resin "Bionore # 1001" manufactured by Showa Polymer
Resin 2 Aliphatic polyester resin "Bionole # 3001"
Resin 3 Polylactic acid resin "Lacia H-440" manufactured by Mitsui Chemicals, Inc.

Antifogging agent 1 Triglycerin monostearate monobehenate (HLB 4.9)
Triglycerin 1 mol, stearic acid 1 mol and behenic acid 1 mol were esterified to obtain triglycerin monostearate monobehenate.
Antifogging agent 2 Triglycerin monolaurate monostearate (HLB6.0)
Triglycerin 1 mol, lauric acid 1 mol, and stearic acid 1 mol were esterified to obtain triglycerin monolaurate monostearate.

Antifogging agent 3 Triglycerin dilaurate (HLB6.7)
Triglycerin 1 mol and lauric acid 2 mol were esterified to obtain triglycerin dilaurate.
Antifogging agent 4 Triglycerin distearate (HLB5.3)
Triglycerin 1 mol and stearic acid 2 mol were esterified to obtain triglycerin distearate.

Antifogging agent 5 Glycerol monostearate (Rikenmar S-100 HLB4.3, manufactured by Riken Vitamin Co., Ltd.)
Anti-fogging agent 6 Diglycerin monooleate (HLB 6.9)
1 mol of diglycerin and 1 mol of oleic acid were esterified to obtain diglycerin monooleate.

Antifogging agent 7 Diglycerin monolaurate (HLB8.5)
1 mol of diglycerol and 1 mol of lauric acid were esterified to obtain diglycerol monolaurate.
Antifogging agent 8 Triglycerin tetrastearate (HLB2.6)
Triglycerin tetrastearate was obtained by esterifying 1 mol of triglycerol and 4 mol of stearic acid.

Antifogging agent 9 decaglycerin monostearate (HLB14.5)
1 mol of decaglycerin and 1 mol of stearic acid were esterified to obtain decaglycerin monostearate.
Anti-fogging agent 10 sorbitan stearate (Rikenmar S-300W HLB5.4 manufactured by Riken Vitamin Co., Ltd.)

Antifogging agent 11 Triglycerin 0.8 mol laurate (HLB10.6)
Triglycerin 1 mol and lauric acid 0.8 mol were esterified to obtain triglycerin 0.8 mol laurate.
A film was prepared with the following composition.

    The evaluation results are shown in Table 4 (high temperature anti-fogging property) and Table 5 (low temperature anti-fogging property).

  By molding the agricultural material using the aliphatic polyester-based resin to which the antifogging agent of the present invention is added, it is biodegradable with a low environmental load, and is long-term both at low and high temperatures. Agricultural materials having stable anti-fogging properties can be supplied.

Claims (3)

In an agricultural resin composition mainly composed of an aliphatic polyester resin comprising a diol and a dicarboxylic acid, the saturated fatty acid is saturated with 4 to 7 HLB and a constituent fatty acid of C12 to 22 per 100 parts by weight of the aliphatic polyester resin. An agricultural resin composition comprising 0.1 to 5 parts by mass of a triglycerin fatty acid ester mainly containing a fatty acid. The agricultural resin according to claim 1, wherein the diol contains at least one of ethylene glycol and 1,4-butanediol, and the dicarboxylic acid contains at least one of succinic acid and adipic acid. Composition. Agricultural material formed as an agricultural film, sheet, or other molded product using the agricultural resin composition according to claim 1 or 2.