KR101362689B1 - Nitrile based plasticizers for biodegradable resin composition - Google Patents

Abstract

The present invention provides a nitrile based plasticizer for a biodegradable resin composition: which maintains the biodegradability of a resin while improving mechanical properties including elongation, tensile strength, and shock resistance; improves the compatibility with the resin; offers excellent thermal stability, elasticity, transparency, adhesive properties, and cold resistance; had wide range of processing temperatures to be applied to biodegradable resins of various fields; does not generate a bleed out; and has excellent durability.

Description

Nitrile based plasticizers for biodegradable resin composition

The present invention relates to a plasticizer for a biodegradable resin composition and a biodegradable resin composition comprising the plasticizer.

In the field of polymers, biodegradable resins degraded under natural environment are attracting attention for their compatibility and biodegradability properties in terms of environmental protection. Accordingly, studies on polylactic acid, copolymers of lactic acid and other aliphatic hydroxycarboxylic acids, polyesters derived from aliphatic polyhydric alcohols and aliphatic polyvalent carboxylic acids, and the like have been actively studied.

In particular, polylactic acid is produced in large quantities at low cost by using fermentation method of L-lactic acid as an environmentally friendly resin, using agricultural products which are free from resource depletion problem. However, such a polylactic acid has a disadvantage in that it is hard, fragile, poorly flexible, and poor in processability because of its high crystallinity and rigid molecular structure. Therefore, it is not suitable for applications requiring flexibility such as films and packaging materials.

As a method for softening poly (lactic acid), a method of adding plasticizer, blending of soft polymer, copolymerization and the like can be considered. However, when a soft polymer is blended, it is limited to a blend of biodegradable resins such as polybutylene succinate from the viewpoint of biodegradability. Therefore, in order to impart sufficient flexibility, a large amount of addition is required, and as a result, the characteristics of polylactic acid may not be sufficiently expressed and may be damaged. In the case of copolymerization, physical properties such as melting point and heat resistance change with the lowering of the crystallinity and the glass transition point.

On the other hand, when a plasticizer is added, a bleed phenomenon in which a plasticizer leaks out to the surface may occur, thereby contaminating the surface or adversely affecting the transparency of the molded article. Therefore, it is necessary to research and develop a plasticizer that can prevent deterioration of properties due to the addition of a plasticizer.

Patent Document 1 (JP-A-1992-335060) relates to a composition obtained by adding a plasticizer to poly (lactic acid), and it is disclosed that diisopropyl adipate and dioctyl sebacate are preferable as plasticizers. However, Flexibility is low for use in film applications. Diethyl phthalate is described as a phthalic acid plasticizer, but diethyl phthalate has a small plasticizing effect, easily bleed out, and there is a risk of harmfulness due to volatility.

As described above, a plasticizer added to improve the physical properties of a biodegradable resin excellent in environmental friendliness has been developed. However, it has various drawbacks in that it has poor processability and mechanical properties. Therefore, it has excellent biodegradability, It is necessary to develop a plasticizer having excellent mechanical properties and compatibility. In addition, eco-friendly biodegradable resins can be applied to a wide range of industrial fields with the application of such plasticizers.

Japanese Patent Laid-Open No. 1992-335060 (Nov. 24, 1992)

Disclosure of the Invention The present invention has been conceived in order to solve the above-mentioned problems, and it is an object of the present invention to provide a plasticizer for biodegradable resins which has durability, water resistance and mechanical properties and satisfactory compatibility with a wide processing temperature range And a biodegradable resin containing the plasticizer for biodegradable resin which does not cause bleeding phenomenon.

In order to accomplish the above object, the present invention provides a plasticizer for a biodegradable resin composition represented by the following general formula (1).

[Chemical Formula 1]

In this case, in Chemical Formula 1, C _n H _2n is a linear or branched (C 2 -C 18) alkylene group, and m is an integer of 1 to 20.

In the plasticizer for a biodegradable resin composition according to an embodiment of the present invention, the plasticizer includes any one or more selected from compounds represented by the following Chemical Formulas 2 to 6.

(2)

(3)

[Chemical Formula 4]

[Chemical Formula 5]

[Chemical Formula 6]

In the plasticizer for a biodegradable resin composition according to an embodiment of the present invention, the biodegradable resin is selected from the group consisting of polylactic acid, polycaprolactone, polyglycolic acid, polycarbonate, polysuccinate and polybutylene succinate Or more.

The present invention relates to a biodegradable resin composition comprising at least one resin selected from the group consisting of polylactic acid, polycaprolactone, polyglycolic acid, polycarbonate, polybutylene succinate and aliphatic polyester, and a plasticizer represented by the following formula Lt; / RTI >

[Chemical Formula 1]

(In Formula 1, C _n H _2n is a straight or branched (C 2 -C 18) alkylene group, m is an integer of 1 to 20.)

In the biodegradable resin composition according to one embodiment of the present invention, the composition includes 1 to 50 parts by weight of the plasticizer represented by the formula (1) based on 100 parts by weight of the resin.

In the biodegradable resin composition according to one embodiment of the present invention, the resin includes those having a weight average molecular weight of 50,000 to 300,000 g / mol.

The plasticizer according to the present invention can improve compatibility with a resin while improving the mechanical properties such as elongation, tensile strength and impact resistance while maintaining the biodegradability of the resin, and has advantages of excellent thermal stability, flexibility, transparency, . In addition, since the processing temperature range is wide and workability is excellent, it can be applied to biodegradable resins in various fields, and there is no bleeding out phenomenon, so that it has excellent durability and is environment-friendly.

Further, the biodegradable resin composition containing the plasticizer of the present invention is excellent in biodegradability, environmentally friendly, biocompatible and bioabsorbable, and has good compatibility with a resin, and has excellent heat stability, elongation, strength, flexibility, transparency, durability Is excellent in physical properties.

Disclosed is a plasticizer for a biodegradable resin composition having excellent flexibility, durability, and mechanical properties, and a biodegradable resin containing the plasticizer, wherein the plasticizer has excellent compatibility while maintaining biodegradability, Provide the displayed plasticizer.

[Chemical Formula 1]

In this case, in Chemical Formula 1, C _n H _2n is a linear or branched (C 2 -C 18) alkylene group, and m is an integer of 1 to 20.

The plasticizer according to the present invention, in one embodiment, can be obtained by the reaction mechanism shown in the following Reaction Scheme 1.

[Reaction Scheme 1]

More specifically, the plasticizer may be represented by specific compounds such as the following Chemical Formulas 2 to 6 (In the present invention, Chemical Formulas 2 to 6 refer to Compounds 2 to 6, respectively), and the following compounds do not limit the present invention. .

(2)

(3)

[Chemical Formula 4]

[Chemical Formula 5]

[Chemical Formula 6]

The plasticizer of the present invention can be used for biodegradable resins, and it is preferable to use polylactide (PLA) as a resin, more preferably PLA or PLLA (poly-L-lactic acid) It is good.

The PLA is excellent in biodegradability and is an intermediate material between polyethylene terephthalate (PET) resin and polyamide (PA) resin as a recyclable resource material. It can be produced by direct polycondensation of lactic acid, May be prepared by ring opening polymerization (ROP). Lactic acid and lactide have isomers of L-, D- and meso type, and their crystallinity, melting point, and mechanical properties vary depending on the composition. In particular, L-lactide polymers are more crystalline than amorphous D-form polymers and have excellent mechanical properties because of their crystallinity.

The PLA is applied to various fields as an environmentally friendly resin material. However, it has a disadvantage that it is easily decomposed when it is heated at a high temperature for a long time and has poor processability, is weak in flexibility even after processing, is easily broken, Therefore, polyethylene glycol and citric acid ester, which have good compatibility with PLA, can be used as a plasticizer. However, their use is limited due to their durability due to bleeding phenomena. Particularly, in the case of polyethylene glycol, alcohols (-OH) are present at both ends, which can adversely affect the resin due to the transesterification reaction with PLA, which is a polyester when heated at a high temperature. Therefore, even when heating glycols, which are structurally expected to have good compatibility with PLA resins, as starting materials, they do not react with PLA, and an ester group having an affinity with PLA rather than an alkyl group is introduced at the end of glycol, It is possible to improve the compatibility and stability with respect to the colloid, and in particular to introduce the t-butyl group as a bulky group at both ends, thereby inducing the wedging action and reducing the bleeding phenomenon.

The present invention provides a biodegradable resin composition comprising at least one resin selected from the group consisting of polylactic acid, polycaprolactone, polybutylene succinate and aliphatic polyester and a plasticizer represented by the following formula (1).

[Chemical Formula 1]

In this case, in Chemical Formula 1, C _n H _2n is a linear or branched (C 2 -C 18) alkylene group, and m is an integer of 1 to 20.

The biodegradable resin composition comprising the plasticizer of the present invention can be prepared by methods well known in the art, for example by adding to crosslinked or hardened resins with a sufficiently high molecular weight or added to the oligomeric precursor and then curing And the like are known.

The biodegradable resin composition according to an embodiment of the present invention is characterized in that PLA (poly lactic acid) or PLLA (poly L-lactic acid) is used as a resin in order to exhibit excellent compatibility of the plasticizer represented by the formula 1, For example, polylactic acid is Ingeo 4032D manufactured by NatureWorks Co., Ltd., and is not necessarily limited to the biodegradable resin.

In the present invention, the weight average molecular weight of the biodegradable resin is preferably 50,000 to 300,000 g / mol.

Also, the composition includes 1 to 50 parts by weight of the plasticizer represented by the formula (1) based on 100 parts by weight of the resin. The plasticizer is preferably contained in an amount of 5 to 30 parts by weight, more preferably 10 to 20 parts by weight.

The biodegradable resin composition according to the present invention is superior in physical properties such as hardness, tensile strength, elongation, elastic modulus, bleeding, and glass transition temperature as compared with the conventional resin composition containing a plasticizer. Accordingly, by using the biodegradable resin composition containing the plasticizer of the present invention, it is possible to produce plastics having excellent tensile strength and low glass transition temperature so that it is excellent in molding into a film, and at the same time, Can be processed into the same flexible product and is excellent in compatibility with the above resins and does not cause bleeding and low extractability due to organic solvents or water, and the lifetime of products such as films and sheets produced using the resin composition Can be extended.

Hereinafter, the constitution and effects of the present invention will be described in more detail in the following specific examples and comparative examples, but these examples are only intended to clarify the present invention and are not intended to limit the scope of the present invention. In the Examples and Comparative Examples, physical properties were evaluated by the following methods.

(evaluation)

(1) Glass transition temperature (Tg) and melting point (Tm)

Tg was measured at -30 to 240 캜 using DSC. Tg is highly related to the compatibility of plasticizers.

(2) Tensile strength and elongation

ASTM D882-10. A film having a thickness of 40 占 퐉, a width of 10 mm and a length of 50 mm was pulled at a crosshead speed of 50 mm / min, and then the position at which the specimen was cut was measured.

(Example 1)

Acrylonitrile (145 ml, 2190) with ethylene glycol (60.0 ml, 957 mmol), KOH (2.00 g, 34 mmol), THF (300 ml) in water (3.0 ml), kept below 20 ^° C. mmol) was added dropwise for 4 hours and then stirred at room temperature for 16 hours. After confirming that the reaction was completed by GC, the solvent was concentrated under reduced pressure, and the residue was dissolved in 250 ml of dichloromethane (CH ₂ Cl ₂ ), washed with 50 ml of water and 30 ml of saturated salt, and 5.0 g of sodium sulfate (Na ₂ SO ₄ ). It was dried using, filtered and concentrated under reduced pressure to give a yellow liquid. The obtained Crude compound was purified by vacuum distillation to give a colorless transparent liquid ( Compound 2 , 82.7 g). (Yield: 73%)

Boiling point: 181 ^o C / 1.2 mmHg; ¹ H nmr (300 MHz, CDCl ₃ ) δ3.73 (t, J = 6.3 Hz, 4H, 2 CH ₂ CH ₂ CN), 3.68 (s, 4H, 2CH ₂ O), 2.62 (t, J = 6.3 Hz , 4H, 2CH ₂ CN).

(Example 2)

Acrylonitrile (85 ml, 1284 mmol) was maintained in a THF (250 ml) solution of 1,4-butanediol (50.0 ml, 560 mmol), KOH (1.70 g, 29 mmol) at 20 ^o C or less. It was added dropwise for 2 hours and then stirred at room temperature for 16 hours. After confirming that the reaction was completed by GC, the solvent was concentrated under reduced pressure, and the residue was dissolved in 250 ml of dichloromethane (CH ₂ Cl ₂ ), washed with 50 ml of water and 30 ml of saturated salt, and 5.0 g of sodium sulfate (Na ₂ SO ₄ ). It was dried using, filtered and concentrated under reduced pressure to give a yellow liquid. The resulting Crude compound was purified by vacuum distillation to give a colorless transparent liquid ( Compound 3 , 76.5 g). (Yield 70%)

Boiling point: 167 ^o C / 0.1 mmHg; ¹ H nmr (300 MHz, CDCl ₃ ) δ 3.64 (t, J = 6.3 Hz, 4H, 2 CH ₂ CH ₂ CN), 3.52 (m, 4H, 2CH ₂ 0), 2.59 (t, J = 6.3 Hz , 4H, 2CH ₂ CN), 1.68 (m, 4H, 2 CH ₂ CH ₂ 0).

(Example 3)

Propylene glycol (50.0 ml, 663 mmol), KOH (4.00 g, 68 mmol), THF (200 ml) solution of water (6.0 ml) with acrylonitrile (95.0 ml, 1435) while maintaining 20 ^o C or less. mmol) was added dropwise for 4 hours and then stirred at room temperature for 24 hours. After confirming that the reaction was completed by GC, the solvent was concentrated under reduced pressure, and the residue was dissolved in 300 ml of dichloromethane (CH ₂ Cl ₂ ), washed with 50 ml of water and 50 ml of saturated salt, and 5.0 g of sodium sulfate (Na ₂ SO ₄ ). It was dried using, filtered and concentrated under reduced pressure to give a yellow liquid. The obtained Crude compound was purified by vacuum distillation to give a colorless transparent liquid ( Compound 4 , 82.7 g). (Yield 68%)

Boiling point: 184 ^o C / 0.5 mmHg; ¹ H nmr (300 MHz, CDCl ₃ ) δ 3.77 (t, J = 6.2 Hz, 4H, 2 CH ₂ CH ₂ CN), 3.71 (m, 1H, O CH HCH), 3.49 (m, 2H, O C H H CH and OCHH CH ), 2.62 (t, J = 6.2 Hz, 4H, 2CH ₂ CN), 1.17 (d, 3H, J = 6.4 Hz, CH ₃ ).

(Example 4)

Dipropylene glycol mixture (Mixture of isomers, 70.0 ml, 528 mmol), KOH (1.50 g, 25 mmol), THF (300 ml) solution of water (2.3 ml) while keeping the temperature below 20 ^o C Lyle (77.0 ml, 1162 mmol) was added dropwise for 4 hours and then stirred at room temperature for 24 hours. After confirming that the reaction was completed by GC, the solvent was concentrated under reduced pressure, and the residue was dissolved in 400 ml of dichloromethane (CH ₂ Cl ₂ ), washed with 50 ml of water and 50 ml of saturated salt, and 5.0 g of sodium sulfate (Na ₂ SO ₄ ). It was dried using, filtered and concentrated under reduced pressure to give a yellow liquid. The resulting Crude compound was purified by vacuum distillation to give a colorless transparent liquid ( Compound 5 , 62.9 g). (Yield: 50%).

Boiling point: 191 ^o C / 1.6 mmHg; ¹ H nmr (300 MHz, CDCl ₃ ) δ3.7 3.58 (m, 6H, 2 CH ₂ CH ₂ CN and 2OC H HCH), 3.49 3.33 (m, 4H, 2OCH H CH and 2OCHHC H ), 2.57 2.51 (m , 4H, 2CH ₂ CN), 1.10 1.07 (m, 6H, 2CH ₃ ).

(Example 5)

Tripropylene glycol mixture (Mixture of isomers, 100 ml, 505 mmol), KOH (1.00 g, 16.9 mmol), THF (150 ml) solution of water (1.5 ml) acrylonitrile while maintaining 20 ^° C. or less Lyle (77.0 ml, 1162 mmol) was added dropwise for 2 hours and then stirred at room temperature for 24 hours. After confirming that the reaction was completed by GC, the solvent was concentrated under reduced pressure, and the residue was dissolved in 200 ml of dichloromethane (CH ₂ Cl ₂ ), washed with 50 ml of water and 50 ml of saturated salt, and 5.0 g of sodium sulfate (Na ₂ SO ₄ ). It was dried using, filtered and concentrated under reduced pressure to give a yellow liquid. The resulting Crude compound was purified by vacuum distillation to give a colorless transparent liquid ( Compound 6 , 57.0 g). (Yield: 38%).

Boiling point: 187 ^o C / 0.8 mmHg; ¹ H nmr (300 MHz, CDCl ₃ ) δ 3.78 3.60 (m, 7H, 2 CH ₂ CH ₂ CN and 3OC H HCH), 3.54 3.34 (m, 6H, 3OCH H CH and 3OCHHC H ), 2.62 2.56 (m , 4H, 2CH ₂ CN), 1.15 (m, 9H, 3CH ₃ ).

(Comparative Example 1)

No plasticizer was used as a control group in order to compare the plasticizing performance with the plasticizer according to the embodiment of the present invention.

(Comparative Example 2)

PEG 400 (poly (ethylene glycol), Mn = 400, Aldrich) was used as a control group to compare the plasticizing performance with the plasticizer according to the embodiment of the present invention.

(Production Example 1)

Biodegradable resin composition

To evaluate the performance of the plasticizers prepared in Examples 1 to 3, 3.60 g of polylactic acid (MW: 207,000 g / mol, Density: 1.25 g / cm ³ ) was added with a plasticizer as shown in Table 1 below and dichloromethane (CH ₂ Cl ₂ ) to make a mixed solution, and the mixture was stirred at room temperature for 16 hours. 26 ml of the stirred solution was poured onto a 12 cm.times.17 cm glass plate using a silicon wall and dried at 20.degree. C. to 25.degree. C. for one week to prepare a film having a thickness of 40 .mu.m. Using this film, 10 mm x 15 mm specimens were prepared and stored at 23 ° C and 50% relative humidity for 48 hours.

Table 1. Physical properties of plasticizer

As shown in the examples of Table 1, when the plasticizer is added, the flexibility is increased due to the low Tg, which can significantly improve the breakage, which is a disadvantage of PLA, and the Tm is lower than when the plasticizer is not used, Decomposition does not occur at a lower temperature, and molding processing can be performed stably, and it is confirmed that the workability can be remarkably improved.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, Those skilled in the art will recognize that many modifications and variations are possible in light of the above teachings.

Accordingly, the spirit of the present invention should not be construed as being limited to the embodiments described, and all of the equivalents or equivalents of the claims, as well as the following claims, belong to the scope of the present invention .

Claims (6)

1. A biodegradable resin composition comprising at least one resin selected from the group consisting of polylactic acid, polycaprolactone, polyglycolic acid, polycarbonate, polybutylene succinate and aliphatic polyester, and a plasticizer represented by the following formula (1).
[Chemical Formula 1]

(In Formula 1, C _n H _2n is a straight or branched (C 2 -C 18) alkylene group, m is an integer of 1 to 20.)
The method of claim 1,
Wherein the resin composition comprises 1 to 50 parts by weight of a plasticizer represented by the formula (1) based on 100 parts by weight of the resin.
The method of claim 1,
Wherein the resin has a weight average molecular weight of 50,000 to 300,000 g / mol.
A plasticizer for a biodegradable resin composition represented by the following formula (1).
[Chemical Formula 1]

(In Formula 1, C _n H _2n is a straight or branched (C 2 -C 18) alkylene group, m is an integer of 1 to 20.)
5. The method of claim 4,
The plasticizer is a plasticizer for a biodegradable resin composition comprising any one or more selected from compounds represented by the following formulas (2) to (6).
(2)

(3)

[Chemical Formula 4]

[Chemical Formula 5]

[Chemical Formula 6]

5. The method of claim 4,
Wherein the biodegradable resin comprises any one or more selected from the group consisting of polylactic acid, polycaprolactone, polyglycolic acid, polycarbonate, polysuccinate, and polybutylene succinate.