KR102106116B1 - Resin composition comprising polyalkylene carbonate - Google Patents

Abstract

The present invention relates to a resin composition comprising polyalkylene carbonate. More specifically, according to the present invention, a polyalkylene carbonate contains a certain amount of nanocrystalline cellulose, which improves thermal stability, tensile strength and dimensional stability, and includes polyalkylene carbonate that maintains transparency. A resin composition is provided.

Description

Resin composition containing polyalkylene carbonate {RESIN COMPOSITION COMPRISING POLYALKYLENE CARBONATE}

The present invention relates to a resin composition comprising polyalkylene carbonate.

Polyalkylene carbonate is an amorphous transparent resin, and unlike aromatic polycarbonate, which is a similar type of engineering plastic, uses carbon dioxide, which is a major cause of global warming, as its main raw material. In addition, polyalkylene carbonate exhibits biodegradability and has the advantage that carbon residues are not completely decomposed into carbon dioxide and water during combustion.

However, polyalkylene carbonates have excellent transparency, tensile strength, elasticity, and oxygen barrier properties, but when processed in the form of pellets or films, blocking phenomena occur, resulting in poor handling and poor dimensional stability. There is this.

Accordingly, attempts have been made to mix and use other types of resins capable of improving the physical properties of polyalkylene carbonates, such as biodegradable polylactide. Since polylactide (or polylactic acid or polylactic acid) resin is based on biomass, unlike conventional crude oil-based resins, it can be used as a renewable resource, and is a global warming gas compared to conventional resins in production. It emits less CO2, has eco-friendly properties such as biodegradation by moisture and microorganisms when landfilling, and is at the same time a material with adequate mechanical strength that is comparable to existing crude oil-based resins.

These polylactide resins have been mainly used for disposable packaging / containers, coatings, foams, films / sheets, and textiles. Recently, polylactide resins are mixed with existing resins such as ABS or polypropylene to reinforce physical properties. Later, efforts to use it for semi-permanent uses, such as mobile phone exterior materials or automobile interior materials, are becoming active. However, the application scope of the polylactide resin is still limited due to the physical weakness of the polylactide itself, such as biodegradation by itself, such as a catalyst used in manufacturing or moisture in the air.

In addition, in order to develop transparent film applications, research is needed to compensate for disadvantages such as thermal stability and dimensional stability while maintaining transparency, which is an advantage of PEC.

It is an object of the present invention to provide a resin composition comprising a polyalkylene carbonate in which thermal stability, tensile strength and dimensional stability are improved, and transparency is maintained, and a molded article using the same.

The present invention is based on 100 parts by weight of a polyalkylene carbonate containing a repeating unit represented by the following formula (1),

1 to 15 parts by weight of nanocrystalline cellulose having a diameter of 5 to 20 nm and a length of 100 to 500 nm; And

200 to 2,500 parts by weight of an organic solvent; containing,

The polyalkylene carbonate provides a resin composition comprising polyalkylene carbonate which is contained in a solution state having a solid content of 15 to 25% by weight.

[Formula 1]

In Chemical Formula 1,

R ¹ to R ⁴ is each independently hydrogen, an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, or a cycloalkyl group having 3 to 20 carbon atoms, and R ¹ to At least any two of R ⁴ may be connected to each other to form a cycloalkyl group having 3 to 10 carbon atoms,

m is an integer from 10 to 1,000.

In addition, the present invention is 100 parts by weight of a polyalkylene carbonate containing a repeating unit represented by the following formula (1); And

Provided is a molded article comprising 1 to 15 parts by weight of nano crystalline cellulose having a diameter of 5 to 20 nm and a length of 100 to 500 nm:

[Formula 1]

In Chemical Formula 1,

R ¹ to R ⁴ is each independently hydrogen, an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, or a cycloalkyl group having 3 to 20 carbon atoms, and R ¹ to At least any two of R ⁴ may be connected to each other to form a cycloalkyl group having 3 to 10 carbon atoms,

m is an integer from 10 to 1,000.

The present invention is to develop a composite material containing a nano-crystalline cellulose (NCC) in a specific content range, to improve the thermal stability, tensile strength and dimensional stability, and also a resin composition comprising a polyalkyl carbonate to maintain transparency It provides an effect of providing a molded article using the same.

1 is a comparison of the transparency results of Examples 1 to 3 and Comparative Example 1 according to an embodiment of the present invention.
Figure 2 is a graph showing the comparison of the results of the thermal stability of Examples 1 to 3 and Comparative Example 1 according to an embodiment of the present invention.

Hereinafter, the present invention will be described in more detail. The terms or words used in the specification and claims should not be interpreted as being limited to ordinary or lexical meanings, and the inventor can appropriately define the concept of terms in order to best describe his or her invention. Based on the principle that it should be interpreted as meanings and concepts consistent with the technical spirit of the present invention.

Also, as used in the present specification, the meaning of “comprising” embodies a specific characteristic, region, integer, step, operation, element, and / or component, and other characteristic, region, integer, step, operation, element and / or It does not exclude the presence or addition of ingredients.

Hereinafter, a resin composition and a molded article comprising a polyalkylene carbonate according to an exemplary embodiment of the present invention will be described.

According to an embodiment of the present invention, with respect to 100 parts by weight of polyalkylene carbonate containing a repeating unit represented by the following Chemical Formula 1, nanocrystalline cellulose having a diameter of 5 to 20 nm and a length of 100 to 500 nm 1 to 15 parts by weight; And 200 to 2,500 parts by weight of an organic solvent; includes, wherein the polyalkylene carbonate is provided with a resin composition comprising a polyalkylene carbonate contained in a solution state having a solid content of 15 to 25% by weight.

[Formula 1]

In Chemical Formula 1,

R ¹ to R ⁴ is each independently hydrogen, an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, or a cycloalkyl group having 3 to 20 carbon atoms, and R ¹ to At least any two of R ⁴ may be connected to each other to form a cycloalkyl group having 3 to 10 carbon atoms,

m is an integer from 10 to 1,000.

The polyalkylene carbonate is an amorphous polymer including a repeating unit represented by Chemical Formula 1, and unlike aromatic polycarbonate, which is a synthetic resin of a similar type, is biodegradable and thermally decomposable at low temperatures. It has the advantage of being completely decomposed into water and free of carbon residues. In addition, the polyalkylene carbonate has a relatively low glass transition temperature (Tg) of about 40 ° C. or less, for example, about 10 to about 40 ° C., and control within this range is possible (Inoue et al. Polymer J., 1982, 14, 327-330).

The method for producing the polyalkylene carbonate of the present invention is not particularly limited, but can be obtained by, for example, copolymerizing an epoxide-based compound with carbon dioxide. Or it can also be obtained by ring-opening polymerization of cyclic carbonate. The copolymerization of the alkylene oxide and carbon dioxide can be performed in the presence of a metal complex compound such as zinc, aluminum, and cobalt.

When polyalkylene carbonate is prepared by copolymerization using an epoxide-based compound and carbon dioxide in the presence of an organometallic catalyst, the epoxide-based compound is ethylene oxide, propylene oxide, 1-butene oxide, 2-butene oxide, iso Butylene oxide, 1-pentene oxide, 2-pentene oxide, 1-hexene oxide, 1-octene oxide, cyclopentene oxide, cyclohexene oxide, styrene oxide or butadiene monooxide, etc. It may be a compound, but is not limited thereto.

The polyalkylene carbonate may be a single polymer including a repeating unit represented by Chemical Formula 1; Or it may be a copolymer containing two or more types of repeating units belonging to the category of Chemical Formula 1, or a copolymer including an alkylene oxide-based repeating unit and the like with the repeating unit represented by Chemical Formula 1.

However, the polyalkylene carbonate is represented by the formula (1) so that the specific physical properties (for example, biodegradability, elongation, flexibility or low glass transition temperature) due to the repeating unit represented by the formula (1) can be maintained. It may be a copolymer comprising at least about 40% by weight of the repeating unit, preferably at least about 60% by weight, more preferably at least about 80% by weight.

According to an embodiment of the present invention, the polyalkylene carbonate is, for example, polyethylene carbonate, polypropylene carbonate, polypentene carbonate, polyhexene carbonate, polyoctene carbonate, polycyclohexene carbonate, or a copolymer thereof. May be, but is not limited to, R ¹ to R ⁴ may be selected as an appropriate functional group considering the mechanical properties or biodegradability of the resin to be finally obtained. For example, when the functional group is hydrogen or a functional group having a relatively small number of carbons, it may be more advantageous in terms of biodegradability, and in the case of a functional group having a relatively large number of carbons, it may be advantageous in terms of mechanical properties such as strength of resin. As a specific example, it has been reported that polyethylene carbonate biodegrades faster than polypropylene carbonate (Inoue et al. Chem. Pharm. Bull, Jpn, 1983, 31, 1400; Ree et al. Catalysis Today, 2006, 115). , 288-294).

Further, in the polyalkylene carbonate, the polymerization degree m of the repeating unit represented by Chemical Formula 1 may be about 10 to about 1,000, preferably about 50 to about 500. And, the polyalkylene carbonate including the repeating unit may have a weight average molecular weight of about 10,000 to about 1,000,000, preferably about 50,000 to about 500,000. As the polyalkylene carbonate has the polymerization degree and weight average molecular weight, the molded article obtained therefrom may exhibit biodegradability along with mechanical properties such as appropriate strength.

In addition, the polyalkylene carbonate has excellent transparency, tensile strength, elasticity, oxygen barrier properties, etc., but when processed in the form of pellets or films, a blocking phenomenon occurs and handling is not easy, and dimensional stability is poor. There are disadvantages.

Therefore, in the present invention, nanocrystalline cellulose is used to compensate for thermal stability, dimensional stability, and the like while maintaining transparency of the polyalkylene carbonane.

The nano crystalline cellulose used in the present invention can be produced by an extraction method and an acid hydrolysis method from bacteria, plant materials, and the like. Specifically, the nanocrystalline cellulose is hydrolyzed with glucose to form an amorphous region, and the crystalline regions are separated to form small-sized rod-shaped nanocellulose. Such nanocrystalline cellulose generally has a diameter of about 5 to 20 nm and a length of 50 nm to 500 nm, but the nanocrystalline cellulose used in the present invention preferably has a diameter of 5 to 20 nm and a length of 100 to 500 nm. In addition, the nanocrystalline cellulose may include a needle-like structure because the purification degree is higher than that of the cellulose nanofibers.

According to an embodiment of the present invention, the nanocrystalline cellulose may be included in about 1 to about 15 parts by weight based on 100 parts by weight of the polyalkylene carbonate, preferably about 2 to about 10 parts by weight. When the nanocrystalline cellulose is included in the above range, it has excellent mechanical properties, biodegradability, and processability, and may have remarkable thermal stability. When the nanocrystalline cellulose is contained in an excessively larger amount than the above range, a problem of lowering the transparency of the resin may occur. In addition, if the content is too small, there is a slight problem of improvement in thermal stability, tensile strength, and dimensional stability.

Meanwhile, the organic solvent may be one or more selected from the group consisting of dimethyl sulfoxide, n, n-dimethylformamide, n-methylpyrrolidone, dichloromethane and chloroform.

The organic solvent may be used in an amount of 200 to 2,500 parts by weight, or 300 to 2,000 parts by weight based on 100 parts by weight of polyalkylene carbonate. If the content of the organic solvent is 200 parts by weight or less, there is a problem that nanocrystalline cellulose is not well dispersed in a solvent, and if it exceeds 2,500 parts by weight, the cost of wastewater treatment may increase due to the use of an excessive amount of solvent, and the film drying time As this lengthens, film thickness control may be difficult.

In addition, various additives may be added to the resin composition of the present invention depending on the use. Examples include, but are not limited to, additives for modification, colorants (pigments, dyes, etc.), fillers (carbon black, titanium oxide, talc, calcium carbonate, clay, etc.). Examples of the modifying additives include dispersants, lubricants, plasticizers, flame retardants, antioxidants, antistatic agents, light stabilizers, ultraviolet absorbers, and crystallization accelerators. Various additives may be added when producing pellets from a polyalkylene carbonate resin composition or when molding a pellet to produce a molded product.

In addition, the method of manufacturing the resin composition of the present invention, it is preferable to use a method of mixing each solution after dispersing polyalkylene carbonate and nanocrystalline cellulose in an organic solvent, respectively.

For example, the above-described polyalkylene carbonate is dispersed in an organic solvent to prepare a solution having a certain solid content. The dispersion method may be performed while stirring for 3 to 4 hours at a temperature condition of 60 to 90 ° C.

The solution is preferably prepared so that the solid content of the polyalkylene carbonate has a concentration of 15 to 25% by weight or 17 to 23% by weight. If the solid content of the polyalkylene carbonate of the solution is less than 15% by weight, the solvent content becomes high and the drying time increases, and if it exceeds 25% by weight, the dissolution time of the resin increases.

The nanocrystalline cellulose can also be used by dispersing in an organic solvent. Preferably, the dispersion method for using the nanocrystalline cellulose is a method of ultrasonically dispersing nanocrystalline cellulose in an organic solvent for 2 to 6 minutes, and then heat generated by ultrasonic treatment is -10 ° C to -20 ° C. Cool at a low temperature, and repeat this process 3 to 5 times to prepare and use a dispersion solution of nanocrystalline cellulose. The nanocrystalline cellulose is preferably used by drying for 3 hours to 4 hours at a temperature of 60 to 90 ° C to remove moisture before use.

Then, the dispersion solution of the polyalkylene carbonate and the dispersion solution of nanocrystalline cellulose are stirred and mixed at a temperature of 60 to 90 ° C for 20 to 40 minutes, and then the mixed solution is poured into a substrate to form a film, and at a constant temperature. It can be dried to obtain a composite form.

The substrate is not limited as long as it has a flat shape. For example, aluminum dishes, chalets, sus trays, and the like can be used. In addition, the drying may be performed using a vacuum oven or the like at a temperature of 60 to 90 ℃.

On the other hand, according to another embodiment of the present invention, 100 parts by weight of a polyalkylene carbonate comprising a repeating unit represented by the following formula (1); And 1 to 15 parts by weight of nanocrystalline cellulose (Nano crystalline cellulose) having a diameter of 5 to 20nm and a length of 100 to 500nm; provides a molded article comprising a.

[Formula 1]

In Chemical Formula 1,

R ¹ to R ⁴ is each independently hydrogen, an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, or a cycloalkyl group having 3 to 20 carbon atoms, and R ¹ to At least any two of R ⁴ may be connected to each other to form a cycloalkyl group having 3 to 10 carbon atoms,

m is an integer from 10 to 1,000.

The molded article of the present invention can be obtained as a product having improved tensile strength, thermal stability and dimensional stability than the conventional one, including nanocrystalline cellulose together with the polyalkylene carbonate. In addition, since the molded article retains the transparency of the polyalkylene carbonate, the transparency of the final product is also excellent.

The molded article according to the present invention may include, for example, a film, a film laminate, a sheet, a filament, a nonwoven fabric, an injection molded article, and the like.

The molded article can be obtained by molding the aforementioned resin composition. The method for forming a molded article by molding the resin composition of the present invention includes, for example, injection molding, compression molding, injection compression molding, gas injection injection molding, foam injection molding, inflation, T die, Calendar method (Calendar), blow molding method (blow), vacuum forming, pressure forming, and the like. In addition, the processing method generally used in the technical field to which the present invention pertains may be used without particular limitation.

Hereinafter, a preferred embodiment of the present invention will be described in detail. However, these examples are only intended to illustrate the present invention, and the scope of the present invention will not be construed as being limited by these examples.

Material substance:

1) PEC: polyethylene carbonate, manufacturer: LG Chem, Mw: 200 kg / mol

2) NCC: Nano crystalline cellulose, Manufacturer: Melodea

3) DMSO: Dimethyl sulfoxide, Manufacturer: Samjeon Chemical

< Example  1>

NCC was dried in an oven at 80 ° C. for 3 to 4 hours to remove residual moisture. To disperse NCC (0.2 g) in DMSO (39.8 g), an ultrasonicator ultrasonic device (model: VC-750, manufacturer: Sonic and materials Inc.) was used, and after ultrasonic treatment for 4 minutes under the condition of Power 750 W, Frequency 20 kHz To cool the generated heat, it was cooled in the freezer for 10 minutes. This process was performed four times to prepare a dispersion of 0.5 wt% NCC and DMSO transparently dispersed.

PEC was dissolved in PEC and DMSO into a four-necked flask to a concentration of 20 wt%, followed by stirring at 80 ° C. After the PEC was sufficiently dissolved, a dispersion of 0.5 wt% NCC and DMSO was poured so that the amount of NCC relative to the PEC solid content was 2 parts by weight, followed by stirring at 80 ° C for 30 minutes. The mixed composition of the stirred PEC and NCC was poured into an aluminum dish, and then dried in an oven at 80 ° C. for one day or more to obtain a film.

< Example  2>

A film was prepared in the same manner as in Example 1, except that a dispersion of 0.5 wt% NCC (0.5 g) and DMSO (99.5 g) was mixed so that the amount of NCC relative to the solid content was 5 parts by weight.

< Example  3>

A film was prepared in the same manner as in Example 1, except that a dispersion of 0.5 wt% NCC (1 g) and DMSO (199 g) was mixed so that the amount of NCC relative to the solid content was 10 parts by weight.

< Comparative example  1>

A film was prepared in the same manner as in Example 1, except that NCC was not added. A 20 wt% PEC / DMSO solution was used.

< Experimental example >

Property evaluation test

For the resin composition specimens prepared in Examples and Comparative Examples, tensile strength, modulus thermal stability, and dimensional stability were measured according to a method described later.

(1) Tensile strength

Measured according to ASTM D882 using TA-XT2i (Micro Stable Systems, UK) equipment. The measurement speed was set at 0.5 mm / sec considering the high elongation of PEC. The sample size was 5 cm in width, 1 cm in height, and 100 μm in height.

(2) Thermal stability

Using a TGA 4000 (PerkinElmer, USA) equipment was measured from 30 ℃ to 330 ℃ at a heating rate of 10 ℃ / min.

(3) Dimensional stability

After the specimen was made to a certain size using a mini-injector, the sample was left at 80 ° C. for 24 hours, and then the dimensions of the sample were compared.

The measurement results for the above experiments are summarized in Tables 1 to 3, respectively. In addition, Figure 1 shows the results of comparing the transparency of Examples 1 to 3 and Comparative Example 1 according to an embodiment of the present invention. Figure 2 is a graph showing the comparison of the results of the thermal stability of Examples 1 to 3 and Comparative Example 1 according to an embodiment of the present invention.

NCC content
(Parts by weight) The tensile strength
(N / ㎟) Modulus
(N / ㎟) Comparative Example 1 - 2.56 2.38 Example 1 2 3.34 4.64 Example 2 5 4.21 22.1 Example 3 10 6.36 45.5

Thermal stability evaluation NCC content
(Parts by weight) Temperature
(℃) Comparative Example 1 - 231 Example 1 2 282 Example 2 5 285 Example 3 10 291

Dimensional stability evaluation Comparative Example 1 Example 1 Before leaving the sample After leaving the sample Before leaving the sample After leaving the sample length (mm) 57.9 45.9 63 61.2 width (mm) 12.7 13.1 12.6 12.5 Thickness (mm) 3.5 4.7 3.2 3.3

1, Examples 1 to 3 of the present invention had similar film transparency to Comparative Example 1.

In addition, through the results of Tables 1 to 3 and FIG. 2, it was confirmed that the Examples of the present invention have superior tensile strength, thermal stability and dimensional stability compared to Comparative Examples. For example, through Example 1, it can be seen that the thermal stability of the resin in which 2 parts by weight of nanocrystalline cellulose is added to the polyethylene carbonate of the present invention is improved by 50 ° C (50% weight loss) compared to that of polyethylene carbonate. In addition, the tensile strength of the resin in which 2, 5, and 10 parts by weight of NCC was added to the polyethylene carbonate tended to increase with the amount of NCC added, and it was confirmed that the dimensional stability was hardly changed even when only 2 parts by weight was added.

Since the specific parts of the present invention have been described in detail above, for those skilled in the art, this specific technique is only a preferred embodiment, and it is obvious that the scope of the present invention is not limited thereby. something to do. Therefore, the substantial scope of the present invention will be defined by the appended claims and their equivalents.

Claims (8)

A solution having a solid content of 15 to 25% by weight by adding 200 to 2,500 parts by weight of an organic solvent to 100 parts by weight of the polyalkylene carbonate containing the repeating unit represented by the following Chemical Formula 1 Manufacturing,
Nano crystalline cellulose having a diameter of 5 to 20 nm and a length of 100 to 500 nm is dispersed in an organic solvent,
The polyalkylene carbonate solution and the nanocrystalline cellulose dispersion are mixed so that the nanocrystalline cellulose is 1 to 15 parts by weight based on 100 parts by weight of the polyalkylene carbonate, and then the resin composition is poured into a substrate and dried. Manufacturing method of molded article:
[Formula 1]

In Chemical Formula 1,
R ¹ to R ⁴ is each independently hydrogen, an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, or a cycloalkyl group having 3 to 20 carbon atoms, and R ¹ to At least any two of R ⁴ may be connected to each other to form a cycloalkyl group having 3 to 10 carbon atoms,
m is an integer from 10 to 1,000.
According to claim 1,
The nanocrystalline cellulose is a method for producing a molded article containing 2 to 10 parts by weight based on 100 parts by weight of polyalkylene carbonate.
According to claim 1,
The polyalkylene carbonate is a method for producing a molded article having a weight average molecular weight of 10,000 to 1,000,000.
According to claim 1,
The polyalkylene carbonate is a polyethylene carbonate, polypropylene carbonate, polypentene carbonate, polyhexene carbonate, polyoctene carbonate, polycyclohexene carbonate and a method for producing a molded article selected from the group consisting of copolymers thereof.
According to claim 1,
The organic solvent is dimethyl sulfoxide, n, n- dimethylformamide, n- methylpyrrolidone, dichloromethane and chloroform.
According to claim 1,
The resin composition is a pigment, dye, carbon black, titanium oxide, talc, calcium carbonate, clay, dispersant. A method of manufacturing a molded article further comprising at least one additive selected from the group consisting of lubricants, plasticizers, flame retardants, antioxidants, antistatic agents, light stabilizers, ultraviolet absorbers, and crystallization accelerators.
delete The method of claim 1, wherein the molded article is in the form of a film.

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