KR101492311B1 - Bio plastic composition and nonwoven fabric using it - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bio-plastic composition and a non-woven fabric using the same, and more particularly, to a bio-plastic composition comprising a poly- And a nonwoven fabric produced by molding the composition.
The bio-plastic composition according to the present invention is excellent in biodegradability, flexibility, and mechanical properties because it solves property deterioration caused by compatibility problems between resin components. In addition, thermal properties can be greatly improved due to the formation of the stereo complex of polylactic acid.
In particular, the nonwoven fabric made from the above composition is excellent in heat resistance and strength, so that it can be expected to meet the trend of the current automobile market where lightweight and eco-friendly concept is applied as an automobile interior material.

Description

TECHNICAL FIELD [0001] The present invention relates to a bio-plastic composition and a non-woven fabric using the same,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bio-plastic composition and a non-woven fabric using the same, and more particularly, to a bio-plastic composition comprising a poly- And a nonwoven fabric produced by molding the composition.

BACKGROUND ART [0002] An automobile interior material is made of a material such as a seat, a trim, a door, a mat, and a carpet, which are provided for automobile interior decoration and convenience. High performance and high heat resistance are required in order to protect them.

In the automotive industry, environmental regulations are being tightened, and the demand for biodegradable plastic materials that can be applied to automotive interior applications is increasing.

Biodegradable plastic in which a hard plastic is naturally decomposed by a decomposition element discharged by a microorganism after a certain period of time has elapsed after being discarded. Although existing shopping bags and plastic bottles are not permanently disassembled, they are a serious factor for environmental problems, but bioplastics are of interest because they provide a clue to solving such environmental problems. Ford of the United States applies biofuels derived from soybeans to automotive interiors, and Toyota of Japan also applies poly (lactic acid) to spare tire boxes, but its application is very limited due to the low heat resistance of bioplastics.

Korean Patent No. 10-1081636 discloses an automobile interior material comprising a polylactic acid foam layer but it is intended to enhance the durability through a reinforcing layer and does not disclose details of the durability and heat resistance of the bio plastic itself Do.

In addition, compatibility between resin compositions such as polylactic acid (PLA), polyhydroxyalkanoate (PHA), polybutylene adipate terephthalate (PBAT) and the like constituting bioplastics is poor, Plastic products are often produced.

Korean Patent Laid-open Publication No. 10-2011-0017780 discloses an eco-friendly resin composition including PLA, PHA, PBS and the like, but does not disclose a proper ratio at the time of mixing and mixing the biodegradable resin.

Therefore, it is required to develop new compatibilizers which can be applied as an automobile interior material with high heat resistance and high functionality and which can provide an excellent compatibility between the compositions and an appropriate blending ratio of the biodegradable resins or provide excellent compatibility thereof It is true.

An object of the present invention is to provide a bio-plastic composition which is improved in heat resistance and mechanical properties as described above, solves the problem of compatibility among components in a composition and can be applied to automobile interior materials.

In order to achieve the above object, the bio-plastic composition according to an embodiment of the present invention includes a blend resin obtained by mixing L-polylactic acid, D-polylactic acid and polyhydroxyalkanoate.

According to another aspect of the present invention, there is provided a nonwoven fabric formed by molding the bio-plastic composition.

The bio-plastic composition according to the present invention is excellent in biodegradability, flexibility, and mechanical properties because it solves property deterioration caused by compatibility problems between resin components. In addition, thermal properties can be greatly improved due to the formation of the stereo complex of polylactic acid.

In particular, the nonwoven fabric made from the above composition is excellent in heat resistance and strength, so that it can be expected to meet the trend of the current automobile market where lightweight and eco-friendly concept is applied as an automobile interior material.

BRIEF DESCRIPTION OF THE DRAWINGS The advantages and / or features of the present invention, and how to accomplish them, will become apparent with reference to the embodiments described in detail below with reference to the accompanying drawings. It should be understood, however, that the invention is not limited to the disclosed embodiments, but is capable of many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, The present invention is only defined by the scope of the claims. Like reference numerals refer to like elements throughout the specification.

Hereinafter, the bio-plastic composition according to the present invention will be described in detail.

The bio-plastic composition according to an embodiment of the present invention includes L-polylactic acid, a blend resin obtained by mixing D-polylactic acid and polyhydroxyalkanoate.

Polylactic acid  Suzy

The bio-plastic composition of the present invention comprises L-polylactic acid and D-polylactic acid as polylactic acid resins, and the polylactic acid of each of the different isomers is mixed to form a stereocomplex.

The L-polylactic acid resin preferably contains 95% by weight or more of L-isomer, preferably 98 to 99.99% by weight of L-isomer and 0.01 to 2% by weight of D-isomer. The D-polylactic acid resin preferably contains 95% by weight or more of D-isomer, preferably 98 to 99.99% by weight of D-isomer and 0.01 to 2% by weight of L-isomer. When the L-poly lactic acid resin contains 95% by weight or more of L-isomer and the D-poly lactic acid resin contains 95% by weight or more of D-isomer, excellent properties such as heat resistance, durability, moldability and hydrolysis resistance Balance can be obtained.

The polylactic acid resin is not particularly limited in molecular weight or molecular weight distribution as long as it is capable of being molded, but preferably has a weight average molecular weight of 80,000 g / mol or more, more preferably 90,000 to 500,000 g / mol. It is good. When the polylactic acid resin has a weight average molecular weight of 80,000 g / mol or more, the polylactic acid resin is excellent in balance of mechanical strength and heat resistance.

It is preferable that 5 to 80 parts by weight of the D-polylactic acid resin is contained in 100 parts by weight of the L-polylactic acid resin, more preferably 10 to 50 parts by weight. When the D-polylactic acid resin is used in an amount less than the above range, there is a problem that the formation of the stereo complex is insignificant and the durability and heat resistance are not greatly improved. When the D-polylactic acid resin is used in excess of the above range, The improvement effect is no longer displayed and the economy is poor.

Polyhydroxyalkanoate ( Poly Hydroxy Alhanoate ) Suzy

The polyhydroxyalkanoate resin of the present invention is an aliphatic polyester comprising a hydroxyalkanoate monomer which is a repeating unit represented by the following formula (1).

(Wherein R ₁ is a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 15 carbon atoms, and n is an integer of 1 or 2.)

The polyhydroxyalkanoate resin may be composed of a homopolymer of a hydroxyalkanoate monomer. Specific examples of the hydroxyalkanoate monomer include 3-hydroxybutyrate in which n is 1 and R ₁ is a methyl group in the general formula (1), 3-hydroxybutyrate wherein n is 1 and R ₁ is an ethyl group, 3-hydroxy valerate, 3-hydroxy hexanoate wherein n is 1 and R ₁ is a propyl group, 3-hydroxy octanoate in which n is 1 and R ₁ is pentyl group, 3- hydroxy octanoate, 3-hydroxy octadecanoate in which n is 1 and R ₁ is an alkyl group having a carbon number of 15, and 3-hydroxy butyrate is 3-hydroxybutanoate. Can be preferably used.

When the hydroxyalkanoate monomer constituting the polyhydroxyalkanoate resin of the present invention is used as a main monomer, monomers of the following general formulas (2) to (6) may be included as an auxiliary mononer, It is not.

In particular, it may contain 10 to 20 mol% of the auxiliary monomer. When the auxiliary monomer is contained in an amount of less than 10 mol%, there is a problem in that the processing temperature condition is narrow and the workability is not easy or flexibility is low, and when the auxiliary monomer is more than 20 mol%, the mechanical properties of the resin are deteriorated.

Examples of the polymer of the main monomer and the auxiliary monomer constituting the polyhydroxyalkanoate resin include, but are not limited to, the following formulas (7) to (11). In this case, X and Y are integers, and X > Y is preferable in terms of securing both the mechanical strength, impact strength and heat resistance of the polyhydroxyalkanoate resin. More specifically, the molar fraction of Y relative to X + Y is preferably 10 to 20 mol%.

In addition, the polyhydroxyalkanoate resin of the present invention may contain, in addition to the above-mentioned polymer, a copolymer composed of two or more different hydroxyalkanoate monomers, for example, a tri-copolymer or a tetra-copolymer have.

The copolymer consisting of two or more different hydroxyalkanoate monomers is preferably a copolymer of 3-hydroxybutyrate and 3-hydroxyhexanoate, poly (3-hydroxybutyrate-co-3-hydroxy Hexanoate) or poly (3-hydroxybutyrate-co-3-hydroxyvalerate) which is a copolymer of 3-hydroxybutyrate and 3-hydroxyvalerate can be used. Wherein the copolymer comprises 80 to 99 mol% of 3-hydroxybutyrate and 1 to 20 mol% of 3-hydroxyhexanoate or 3-hydroxyvalerate.

Blend ( Blend ) Suzy

The blend resin of the present invention is excellent in mechanical properties such as durability and heat resistance as compared with the case of containing only polylactic acid resin and polyhydroxyalkanoate resin.

The blend resin of the present invention is characterized in that the content of the polylactic acid resin (sum of L-polylactic acid and D-polylactic acid) is larger than the content of the polyhydroxyalkanoate resin. Particularly, when the content of the polylactic acid resin is less than the content of the polyhydroxyalkanoate resin, the mechanical properties are not improved.

More specifically, the amount of the polyhydroxyalkanoate resin is preferably 1 to 50 parts by weight, more preferably 5 to 40 parts by weight, based on 100 parts by weight of the polylactic acid resin. If the polyhydroxyalkanoate resin is used in an amount less than the limited range, the brittleness of the polyhydroxyalkanoate can not be improved. If the polyhydroxyalkanoate resin is used in excess of the limited range, the dispersibility of the polyhydroxyalkanoate resin And the physical properties may be lowered.

The bio-plastic composition according to an embodiment of the present invention further comprises a reactive compatibilizer.

The compatibilizer allows the polymers to mix well through the chemical reaction between the functional groups introduced into the composition polymer and the compatibilizer during the melt mixing of the polymers. There are two types of compatibilizers: a non-reactive compatibilizer that uses only physical properties and a reactive compatibilizer that accompanies the reaction when extruded. Unreacted compatibilizers are mostly random copolymers, graft copolymers, block copolymers and the like, and reactive groups are attached thereto to be a reactive compatibilizer in many cases. Examples of the reactive groups include maleic anhydride, epoxy, and carbonyl groups, and these reactive groups are mostly attached to the end or side of the compatibilizing agent.

The compatibilizing agent included in the bio-plastic composition of the present invention is preferably a reactive compatibilizer, particularly having an epoxy group as a reactor. The compatibilizing agent having the above epoxy group as a reactor is not limited, but it is preferable to use at least one selected from glycidyl methacrylate or maleic anhydride in consideration of the physical properties of the composite material.

Glycidyl methacrylate has a structure represented by the following formula (12), and maleic anhydride has a structure represented by the following formula (13).

The compatibilizer of the present invention is preferably 1 to 20% by weight, more preferably 1 to 5% by weight, of the total weight of the bio-plastic composition. When the compatibilizing agent is used in an amount of less than 1% by weight, the effect of increasing the compatibility is lowered and the mechanical properties of the product are poor. When the compatibilizing agent is used in an amount exceeding 20% by weight, The interface between the resins is formed too thick, and the mechanical properties may deteriorate.

In addition, the reactive compatibilizer may include an ionomer. This shows that it is excellent in miscibility and mechanical properties as compared with a bioplastic composition containing no ionomer. The ionomer of the present invention is not particularly limited as long as a small amount of ionic groups are contained in the nonpolar polymer chain, but it is also possible to use a copolymer of an? -Olefin and?,? - unsaturated carboxylic acid, a polymer in which a sulfonic acid group is introduced into polystyrene, Olefin, an alpha, beta -unsaturated carboxylic acid, and a copolymerizable monomer thereof, or a mixture thereof is neutralized with a metal ion of 1 to 4. The method of preparing the ionomer resin is well known to those skilled in the art and is commercially available.

The? -Olefin may be ethylene, propylene, butene or the like, but is not limited thereto. These may be used alone or in combination of two or more. Of these, ethylene is preferred. The α, β-unsaturated carboxylic acid may be acrylic acid, methacrylic acid, ethacrylic acid, itaconic acid, maleic acid, etc., but is not limited thereto. These may be used alone or in combination of two or more. Of these, acrylic acid and methacrylic acid are preferable.

Examples of the copolymerizable monomer include acrylic acid esters, methacrylic acid esters, styrene, and the like, but are not limited thereto. The first to fourth metal ions include lithium, sodium, potassium, magnesium, barium, lead, tin, zinc, aluminum, ferrous and ferric ions. Of these, lithium, sodium, potassium and zinc are preferred.

The ionomer has an acid content of 3 to 25% by weight, preferably 15 to 25% by weight. The higher the acid content, the higher the surface hardness and tensile strength, but the impact strength is lowered.

The ionic group of the ionomer preferably has a mole fraction of 0.1 to 5 mol%. More specifically, when the molar fraction of the ionic group is less than 0.1 mol%, there is a fear that the desired property may not be realized because the ionic group content for improving the resin property is small, and when the molar fraction of the ionic group exceeds 5 mol% There is a concern that cluster formation of the ion groups may lower the resin properties.

In addition, the bio-plastic composition of the present invention may further comprise an additive, wherein the additive may be at least one selected from a filler, a softener, an anti-aging agent, a heat aging inhibitor, an antioxidant, a dye, .

Production of nonwoven fabric

The bio-plastic composition comprising the stereocomplex of polylactic acid may be made of fibers and then formed into a felt-like nonwoven fabric by arranging the fibers in parallel or in an indefinite direction without going through a woven process.

The nonwoven fabric is formed by spinning the composition to form microfine fibers by high-pressure hot air blowing, and then melt-blown the microfibers by bonding them with a uniform molten fiber web. The web is formed by self- A thermal bonding method in which fibers are formed by melting or igniting with heat or pressure, an air ray method using compressed air and an adhesive, etc. But it is not limited thereto, and it is more preferable to produce it by the melt blown method.

Since the nonwoven fabric exhibits excellent heat resistance and mechanical properties, the nonwoven fabric can be applied as an interior material such as a seat, a trim (ceiling, a door), a mat, and a carpet of an automobile.

The bioplastic composition according to the present invention and the nonwoven fabric can be produced by molding the bioplastic composition according to the present invention. The evaluation results of the bioplastic composition of the present invention (Examples and Comparative Examples) are as follows.

Example  And Comparative Example

Example 1

As the L-polylactic acid resin, 4032D manufactured by NatureWorks LLC (containing 1.2-1.6 wt% of D-isomer) was used. D-polylactic acid resin was D-Lactide (D, D-Lactide 99 Weight% or more) was polymerized to have a weight average molecular weight of 50,000 g / mol. Then, the PHA resin was dried in a vacuum oven at 70 DEG C for 24 hours to obtain a PHA resin. At this time, the PHA resin is composed of a copolymer of the following formula (10), and X = 8.0 and Y = 2.0.

[Chemical formula 10]

60 g of the L-polylactic acid resin, 20 g of the D-polylactic acid resin and 20 g of the PHA resin were mixed to prepare a nonwoven fabric by the melt blown method.

Example 2

A nonwoven fabric was prepared in the same manner as in Example 1 except that 80 g of the L-polylactic acid resin, 10 g of the D-polylactic acid resin and 10 g of the PHA resin were mixed.

Example 3

A nonwoven fabric was prepared in the same manner as in Example 1 except that 60 g of the L-polylactic acid resin, 10 g of the D-polylactic acid resin and 30 g of the PHA resin were mixed.

Example 4

99 mol% of succinic acid, 1 mol% of sulfonated di-methyl fumarate (SDMF), and 1,4-butanediol were added to the PHA resin of Example 1 to prepare a PHA resin having a molar fraction of ionic groups of 0.5 mol% An ionomer was prepared and 5 g of the ionomer was added to prepare a blend resin.

(X = 99.5, Y = 0.5)

Comparative Example 1

Using 100 g of the L-polylactic acid resin, a nonwoven fabric was produced in a meltblown manner.

Experimental Example 1  - Analysis of mechanical strength

The nonwoven fabrics prepared in Examples 1 to 4 and Comparative Example 1 were cut to a width of 75 mm × 12.5 mm and a height of 3 mm to prepare specimens. The specimens were then measured for mechanical strength according to ASTM D-638 using Izod method at room temperature , And the results are shown in Table 1 below.

PLA: PHA
Mixing ratio The tensile strength
(Tensile Strength: MPa) tenacity
(Toughness: MPa) Elongation at break
(Elongation at break:%) Example 1 8: 2 64.3 70.2 111.2 Example 2 9: 1 55.1 60.4 95.2 Example 3 7: 3 56.5 58.2 100.4 Example 4 8: 2 70.2 76.4 114.9 Comparative Example 1 10: 0 23.1 4.2 5.0

From Table 1, it was confirmed that when the content of the L-PLA resin in the blend resin is larger than the content of the PHA resin, it shows excellent characteristics in toughness and elongation at break. This is because the compatibility of PLA and PHA is improved when the blend ratio is within a certain range, and the mechanical strength is improved due to the formation of the stereo complex. On the other hand, when L-PLA resin was used, the overall mechanical strength such as elongation at break was lowered.

It was also confirmed that the ionomer of Example 4 containing an ionomer containing a certain amount of ionic groups exhibited better tensile strength, toughness and elongation at break.

Experimental Example 2  - Analysis of heat resistance

The nonwoven fabric prepared in Examples 1 to 4 and Comparative Example 1 was cut to a width of 75 mm, a length of 12.5 mm and a height of 3 mm to prepare specimens. The heat distortion temperature (HDT) was measured according to ASTM D-648, The results are shown in Table 2 below.

Heat deformation temperature (캜) Example 1 112 Example 2 103 Example 3 104 Example 4 116 Comparative Example 1 80

As shown in Table 2, it was confirmed that the nonwoven fabric of the Examples exhibited excellent heat resistance as compared with the nonwoven fabric of Comparative Example made of only L-polylactic acid.

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments. Therefore, the scope of the present invention should not be construed as being limited to the embodiments described, but should be determined by the scope of the appended claims, as well as the appended claims.

Claims (11)

A polylactic acid resin comprising 10 to 50 parts by weight of a D-polylactic acid resin mixed with 100 parts by weight of an L-polylactic acid resin, and a blend resin mixed with a polyhydroxyalkanoate resin, 5 to 25 parts by weight of a polyhydroxyalkanoate resin is mixed with 100 parts by weight of a lactic acid resin. The polyhydroxyalkanoate resin is any one of the following formulas (7), (8) and (11) X> Y, wherein the ionomer having an acid content of 15 to 25% by weight is contained as a reactive compatibilizer, the ionic group in the ionomer has a mole fraction of 0.1 to 5 mol% Wherein the reactive compatibilizer comprises 1 to 20% by weight of the total weight of the bio-plastic composition.
(7)

[Chemical Formula 8]

(11)

delete delete delete delete The method according to claim 1,
Wherein the polyhydroxyalkanoate resin comprises 10 to 20 mol% of an auxiliary monomer.
delete delete A nonwoven fabric molded from the bioplastic composition of claim 1 or 6.
10. The method of claim 9,
Wherein the bio-plastic composition is manufactured through any one of melt-blown, spun bond, thermal bonding, and air-ray.
10. The method of claim 9,
Characterized in that the nonwoven fabric is used as an automobile interior material.