JP2003261752A - Biodegradable resin solution - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a biodegradable polyester resin solution in which a solvent having easy handleability and excellent safety is used. <P>SOLUTION: In the biodegradable polyester resin solution, a compound represented by formula (1) (wherein R<SB>1</SB>is a 1-3C alkyl; R<SB>2</SB>is H, methyl or ethyl; and R<SB>3</SB>and R<SB>4</SB>are each H, a 1-5C alkyl or an aryl) is used as a solvent, a plasticizer or a compatibilizer. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for facilitating the application of biodegradable polyester resins, such as polylactic acid having biodegradability, for example, paper, various films, metal sheets and woodworking. A biodegradable polyester resin that is applied to materials, yarns, fibers, etc., as a protective film, as a binder for imparting functions, or for the purpose of adhesion and has excellent coating performance, fine processability, and solution stability. It is about. In the present invention, a biodegradable polyester resin containing polylactic acid and a plasticizer, a filler, an antioxidant, if necessary,
Used in combination with leveling agents, thickeners, decomposition stabilizers, and other biodegradable resins such as modified starch to adjust the performance according to various applications.

[0002]

[Industrial field of application] Application of GreenPla, which is useful in a resource recycling society and reduces environmental pollution compared to conventional synthetic resin materials, is used in agriculture, forestry and fisheries industry materials, Civil engineering / construction materials, leisure products,
Used in a wide range of fields such as packaging film / container, sanitary goods, office supplies, clothing, medical / agrochemical / fertilizer / seed packaging, tree planting materials, non-woven fabrics, book / bag / composite film adhesives, textile products, etc. To be done. Therefore, it is widely used for paper processing, film processing, sheet processing, woven cloth processing, non-woven cloth, metal processing, plastic processing, wood processing, stone processing, glass, etc. for surface protection and modification and as an adhesive material. .

[0003]

2. Description of the Related Art Biodegradable polyester resins have hitherto been used in various paper processing examples: JP-A-6-500603, fiber cloth product examples: JP-A-4-334448, JP-A-8-27280, JP-A-8-27280, JP-A-5-27280. -311600, etc.,
Woods, metals, inorganic materials, fertilizer, etc.
92, Application example to seeds JP-A-2-23517, JP-A-4
-89384, JP-A-5-85873, JP-A-7-33.
577, and Japanese Patent Laid-Open No. 9-26 for various plastics.
3476, JP-A-4-334448 for materials, and JP-A-9-78494 for coating agents and adhesives have been proposed and studied. On the other hand, many solvent-based resins have been conventionally used. For example, as synthetic resin, synthetic rubber type,
Many resins have been selectively used according to the intended use, such as vinyl acetate type, ethylene vinyl acetate type, acrylic resin type, urethane resin type, olefin resin type, and styrene resin type. However, it relies on petroleum-based raw materials to cause resource depletion and environmental pollution.

From this background, a plastic that can be used in the same manner as conventional plastics, and after being used, is involved in the formation of biomass by microorganisms in the natural world, is decomposed into water and carbon dioxide, and returns to nature. As a resource recycling resin using a plant as a starting material, a proposal has been made and is being put to practical use. It is necessary to promote the utilization of these. The biodegradable polyester resin is a resin that meets this requirement, and a technique that can be widely used is required.

However, although biodegradable polyester resins are being put to practical use such as molding technology and film forming technology,
It cannot be applied like conventional paints and adhesives, and its elasticity is poor during resin processing, limiting its applications. This is because compounds that can dissolve and compatibilize biodegradable polyester resins are limited, so new solvents, new plasticizers, combinations with other resins, modification studies by compounding methods, etc. Is being attempted.

[0006]

As described above, biodegradable polyester resins, particularly polylactic acid, have recently been industrially made possible to be molded and formed into a film, but coating with a thin film
There is a demand for a method that can be easily applied to a wide range by application to surface treatment, application as an adhesive, and modification, and there has been an urgent need to study compounds that make these possible. For example, Japanese Patent Application Laid-Open No. 4-334448 describes a technique of coating polylactic acid or its derivative on paper or the like. Here, the clothing is formed by impregnating a normal solvent of polylactic acid or its derivative with a spray, heat melting, or the like. ing. Japanese Patent Publication No. 7-504227 proposes a method of imparting melt stability with a lactide monomer. Further, in JP-A-8-198972, foaming using an organic solvent, in JP-A-2001-131433, ester solvents such as methyl formate, propyl formate and butyl formate as solvents, and chlorine such as chloroform and carbon tetrachloride are used. Examples of the solvent include aromatic solvents such as benzene, toluene and xylene. However, there has been no proposal of a compound which is easy to handle, easy to handle, safe to use as a solution, and also usable as a plasticizer.

[0007]

[Means for Solving the Problems] As a result of the research conducted by the inventors,
It has been found that the problem can be solved by a biodegradable polyester resin solution obtained by using the compound represented by the following general formula (1) as a solvent, a plasticizer and a compatibilizer. .

[0008]

However, R1 is an alkyl group having 1 to 3 carbon atoms, R2 is hydrogen or a methyl group or an ethyl group, and R3, R
4 represents hydrogen or an alkyl or allyl group having 1 to 5 carbon atoms.

Biodegradation characterized in that the general formula (1) is a reaction product of ethylene glycol or propylene glycol, or 1,2- or 1,3- or 1,4-butanediol and an aldehyde or ketone. Biodegradable polyester-based resin solution, the biodegradable polyester-based resin solution containing 1 to 40% by weight of the biodegradable polyester-based resin and 3% by weight or more of the compound of the present invention, the coating biodegradable The polyester resin may be used as a plasticizer and may be used in combination with other plasticizers or other biodegradable resins, if necessary.

The biodegradable polyester resin solution must contain the biodegradable polyester resin in an amount of 1 to 40% by weight, preferably 1 to 30% by weight. The subsequent resin film thickness cannot be obtained, and a resin solution cannot be prepared if it is used in excess of 40% by weight. Further, it is necessary to contain the compound represented by the general formula (1) in an amount of 3% by weight or more, and below that, the biodegradable polyester-based resin cannot be dissolved, and the biodegradable polyester-based resin solution of the present invention is intended. Can't get

Examples of the biodegradable polyester resin used in the present invention include polybutylene succinate, polyethylene succinate, polyethylene succinate adipate, polycaprolactone, polyglycolic acid, and polylactic acid such as L-lactic acid in the molecule. , D-lactic acid, polylactic acid obtained from a mixture thereof, or a monomer unit thereof may be chemically modified. Also, for example, the monomer unit is L
-A system in which polylactic acid consisting of lactic acid and polylactic acid whose monomer unit is D-lactic acid are mixed is also included. Having a hydroxyl group and a carboxyl group in the molecule as a monomer unit, for example, glycolic acid, 3-hydroxybutyric acid, 4-hydroxybutyric acid, 4-hydroxyvaleric acid, 5-hydroxyvaleric acid, 6-hydroxycaproic acid, etc. It is possible to include a polylactic acid containing a mixture of two or more of the above or chemically modified thereto, and further a mixed polymer thereof.

The method for producing the biodegradable polyester resin used in the present invention is not particularly limited. For example, in the case of polylactic acid, a method for producing by direct dehydration polycondensation from lactic acid or lactic acid and another hydroxycarboxylic acid, a method for obtaining lactide, glycolide, ε-caprolactone or a ring-opening polymerization thereof, and a method for obtaining by other transesterification are available. Can be mentioned,
It is not limited to these.

When the compound represented by the general formula (1) is exemplified, 1,
3-dioxolane, 4-methyl-1,3-dioxolane, 2-nbutyl-1,3-dioxolane, 2,2-di-n-propyl-1,3-dioxolane, 2-methyl-
1,3-dioxolane, 2,2-di-n-propyl-4-
Methyl-1,3-dioxolane, 2,2-diisopropyl-4-methyl-1,3-dioxolane, 2-nbutyl-4-methyl-1,3-dioxolane, 2-npropyl-4-methyl-1, 3-dioxolane, 2-methyl-2
-Isobutyl-4-methyl-1,3-dioxolane, 2
-N-butyl-4-ethyl-1,3-dioxolane, 2-
n-propyl-4-methyl-1,3-dioxolane, 2-
n-Butyl-4-methyl-1,3-dioxane, 2-n-propyl-1,3-dioxepane, 2,2-di-n-propyl-4-methyl-1,3-dioxolane and the like can be exemplified, but not limited thereto. It is not something that will be done.

Since these biodegradable polyester resins have the property of modifying, compatibilizing and solvent properties, the compounds and combinations represented by the general formula (1), other solvent systems, plasticizers It can be widely applied in combination with agents and other resin-based biodegradable resins.

The compound of the general formula (1) is generally a glycol such as ethylene glycol or propylene glycol and methyl isobutyl ketone, methyl ethyl ketone or di-n.
It can be obtained by reacting a ketone or aldehyde such as -propylketone, formaldehyde, acetaldehyde or n-propylaldehyde under an acidic catalyst. Although illustrated, it is not limited to this manufacturing method.

Specific examples of the solvent which can be blended and used are:
Various ethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, benzyl ether, dihexyl ether, methyl cellosolve acetate, ethyl cellosolve acetate Etc.Esters thereof, ethyl lactate, ethyl acetate, butyl acetate, benzyl acetate, ethyl benzoate, diethyl oxalate,
Esters of ethylene carbonate, propylene carbonate, γ-butyl lactone, etc., ketones such as methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, acetonyl acetone, isophorone, fatty acids such as caproic acid, capric acid, caprylic acid, ethanol, isopropyl alcohol , Alcohols such as 1-octanol, 1-nonanol and benzyl alcohol, and aromatic hydrocarbons such as toluene and xylene can be usually exemplified.

Examples of the plasticizer to be used in combination are phthalic acid ester, aromatic carboxylic acid ester, aliphatic dibasic acid ester, fatty acid ester derivative, various phosphoric acid ester, polyester plasticizer, epoxy plasticizer, and high plasticizer. One or more molecular plasticizers may be selected and used as required.

Specific examples include dimethyl, diethyl,
Phthalates such as dibutyl and dioctyl, phthalates such as ethylphthalylethyl glycolate, ethylphthalylethyl glycolate, ethylphthalylbutyl glycolate, butyl oleate, various glycerin esters, butyl adipate, adipic acid -Aryl dibasic acid esters such as n-hexyl, octyl trimellitate, diethylene glycol benzoate, aromatic carboxylic acid esters such as octyl oxybenzoate, methyl acetylricinoleate, triethyl acetylcitrate,
Examples include diacetylglycerin, esters such as glycerin monostearate, various commercially available phosphoric acid esters, epoxidized soybean oil, epoxidized castor oil, alkylepoxystearate, epoxy plasticizers, other liquid rubbers, and polyesters. it can.

The biodegradable resin used for modification is not particularly limited, but examples thereof include modified starch type, cellulose acetate type,
Any of polyhydroxybutyric acid type, polyethylene oxide type, polyvinyl alcohol type, chitosan type, etc. may be used, and the application can be further promoted by effectively utilizing the performance thereof. Further, not only the biodegradable resin, but also an ordinary resin can be used together if necessary.

Therefore, these solvents, plasticizers and biodegradable resins are utilized, and further, if necessary, fillers, dispersants, antioxidants, rust preventives, antistatic agents, wettability improvers, A fluidity modifier, a water repellent, a lubricant and the like can be used in combination according to the purpose of use. In particular, the following waxes can be used together for the purpose of adjusting fluidity, water repellency and lubrication. Examples thereof include natural wax and synthetic wax. Examples of natural waxes include carnauba wax, rice wax, candelilla wax, montan wax and derivatives thereof, mineral oil wax, microcrystalline wax, paraffin wax and the like, and derivatives having a carboxyl group added thereto, and synthetic waxes. Oxides such as polyethylene wax and polypropylene wax, and modified waxes such as derivatives having a carboxyl group added thereto are also included. Further, there are copolymer waxes with ethylene and propylene, and oxide waxes of ethylene copolymer waxes. This system can be used in various types including terpolymer system by changing the copolymerization partner. Further, addition wax of maleic acid, fatty acid ester-based wax and the like can be exemplified. Industrially preferable are polyethylene wax, polypropylene wax, modified wax, copolymer wax with ethylene or propylene, ethylene copolymer wax, and the like. And a derivative having a carboxyl group, a paraffin wax having an acid value, a carnauba wax, and the like. Generally, it is used in a small amount.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION The biodegradable polyester resin solution according to the present invention may be used in any general manner, including, but not limited to, spraying, spraying,
Immersion method, bar coater method, blade coater method, doctor blade method, air knife coater method, calendar method,
Known or publicly known methods such as an extrusion method, a screen printing method and a gravure printing method may be used alone or in combination. As for the molding of the polylactic acid after plasticization, the intended product can be obtained by a commonly used known / official molding method.

In the present invention, a biodegradable polyester resin solution containing, for example, 1 to 40% by weight of polylactic acid and 3% by weight or more of the compound of the present invention is used as a solvent, a plasticizer, and a compatibilizer. As a biodegradable polyester-based resin solution for coating / adhesion, by further using other plasticizers and other biodegradable resin-based solutions, application to various fields can be made possible.

[0024]

The present invention will be described with reference to the following examples. However, the present invention is not limited to these Examples and Comparative Examples. Example 1 High-viscosity stirrer, thermometer, temperature controller, heating
200 g of biodegradable resin and 800 of 1,3-dioxolane in a mixing / synthesis facility with an internal capacity of 1.0 kg equipped with a cooling facility.
g was charged and the temperature was raised to 80 ° C. After stirring for 3 hours, it was cooled.

Examples 2 to 9 Examples 2 to 9 were carried out according to the formulation shown in Table 1 according to the equipment, conditions and procedures used in Example 1.

Example 10 The apparatus used in Example 1 was charged with 150 g of the biodegradable resin solution prepared in Example 4 and 850 of methyl ethyl ketone.
After charging g, the temperature was raised to 50 ° C. and the mixture was stirred for 1 hour to obtain a biodegradable polyester resin solution. The following examples are shown in Table 1.
Put together.

[0027]

[Table 1]

Description of table <Biodegradable resin> Polylactic acid (a) Lacty 9800: Shimadzu (b) LACEA H-100: Mitsui Chemicals, Inc. polycaprolactone (c) Cell Green PH-7 : Polybutylene succinate type (d) Bionole 300 manufactured by Daicel Chemical Industries, Ltd.
1: Showa High Polymer Co., Ltd. <other resins> Chitosan Cellulose (e) Delon CC: Aicello Chemical Co., Ltd. <Compound of the present invention> 1: 1,3-dioxolane 2: 4-methyl-1,3 -Dioxolane 3: 2-npropyl-4-methyl-1,3-dioxolane <other compounds> 4: 1,4-dioxane 5: glycerin fatty acid ester (RIKEN VITAMIN Co., Ltd.)
Manufactured: PL: 009) 6: Methyl ethyl ketone 7: Dibutyl phthalate

Table 2 summarizes the evaluation results of the samples obtained in Examples 1-10.

[0030]

[Table 2]

The test of the coating film was measured by the following method. 1. Solution properties: Put the sample in a sample bottle and visually observe the appearance. 2. Coated film properties: The uncoated paper was applied with a No. 20 bar coater and dried at 120 ° C. for 2 minutes, and then the film forming property was visually evaluated. Water resistance was evaluated by visually observing the degree of bleeding after dropping 2 to 3 drops of water for 5 minutes. It was rated as ⊚ and evaluated in three stages. 3. Physical properties of coating film: A film having a film thickness of about 30 μm was prepared and the breaking strength and elongation rate were measured by a tensile tester. Unit strength MPa, elongation%.

[0032]

By combining the biodegradable polyester resin, especially the polylactic acid resin, with the compound according to the present invention,
The solubility and the plasticization of the resin can be facilitated. It is possible to contribute by widely applying these biodegradable polyester resins in order to contribute to a resource recycling society and reduce environmental load.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Mayo Michihiko             5-2931, Uragocho, Yokosuka City, Kanagawa Toho             Within the industry F term (reference) 4J002 CF031 CF181 CF191 EL106                       FD020 FD026 FD170 FD206                       GH01 GJ01                 4J200 AA04 BA05 BA12 BA13 BA14                       BA15 BA16 BA18 BA20 DA19                       DA20 EA03

Claims (6)

[Claims] 1. A biodegradable polyester resin solution in which a compound represented by the general formula (1) is used as a solvent, a plasticizer and a compatibilizer in a degradable polyester resin. Here, R1 represents an alkyl group having 1 to 3 carbon atoms, R2 represents hydrogen, a methyl group or an ethyl group, and R2 and R3 represent hydrogen or an alkyl or allyl group having 1 to 5 carbon atoms. 2. The general formula (1) of claim 1 is a reaction product of ethylene glycol or propylene glycol, or 1,2- or 1,3- or 1,4-butanediol with an aldehyde or ketone. Claim 1 characterized by the above.
The biodegradable polyester resin solution described. 3. A biodegradable polyester resin is used in an amount of 1 to 40.
The biodegradable polyester resin solution according to claim 1, wherein the biodegradable polyester resin solution is contained in a weight percentage. 4. The biodegradable polyester resin solution according to claim 1, wherein polylactic acid is used as the biodegradable polyester resin solution. 5. The compound (1) according to claim 1, wherein 1 to 40% by weight of polylactic acid is used as the biodegradable polyester resin.
The biodegradable polyester resin solution according to claim 1, which contains 3% by weight or more. 6. A biodegradable polyester resin solution containing 1 to 40% by weight of polylactic acid and 3% by weight of 1,3-dioxolane as the compound of the general formula (1) according to claim 1.
The biodegradable polyester resin solution according to any one of claims 1 to 5, containing the above.