KR102464095B1 - Biodegradable Rubber Composition - Google Patents

Abstract

A biodegradable rubber composition capable of having high biodegradation efficiency by replacing some of components included in rubber with a biodegradable material is provided. The biodegradable rubber composition contains a hydroxyalkanoate (HA) resin, a peroxide crosslinker and rubber crosslinkable by the peroxide crosslinking agent.

Description

Biodegradable Rubber Composition

The present invention relates to a biodegradable rubber composition, and more particularly, to a biodegradable rubber composition that can have high biodegradation efficiency by replacing some of the components included in the rubber with a biodegradable material.

In general, synthetic plastics are used for various purposes all over the world as packaging materials that are indispensable for modern people's lives due to their excellent properties and cheap and light properties. However, synthetic plastics having the above characteristics are becoming increasingly serious environmental pollution problems due to the problem of poor decomposition, which is an advantage and a disadvantage, and therefore, recently, countries are attracting attention to find a solution thereto. That is, conventional methods such as landfill, incineration, and recycling have been mainly used for the treatment of synthetic plastics, but these methods could not completely solve the environmental pollution problem. Therefore, attention is currently focused on the development of so-called degradable plastics that allow used plastics to self-decompose.

Currently, various types of degradable plastics have been developed from various technologies and raw materials, and among them, poly lactic acid (hereinafter referred to as 'PLA') is manufactured cheaply in large quantities by developing a fermentation method for L-lactic acid. , and has excellent characteristics such as fast decomposition under composting conditions, resistance to mold, and resistance to food exploitation, so the scope of its application is expanding. Various attempts are being made to give these PLA properties suitable for use in each country.

However, in the case of biodegradable polymers such as PLA, which correspond to polymers having rigidity that can be used as structures or exteriors, studies on such biodegradability have not been conducted much in the case of rubber having high elasticity.

On the other hand, molded articles such as automobile tires and shoe soles contain rubber components, which have a medicinal effect on the global environment in the process of being discarded. Research on imparting biodegradability to molded products made with Examples include vegetable polysaccharides such as starch and cellulose (Korea Patent No. 10-0674670, Korean Patent No. 10-0721443, Korea Patent Publication No. 10-2014-0065615), animal polysaccharides such as chitin and chitosan (Korea Bio-fillers such as Unexamined Patent Publication No. 10-1997-0042722 and Korean Patent No. 10-0271832), and biodegradable plastics such as polyhydroxybutylene, polylactate, and polycaprolactone (Japanese Patent Laid-Open No. 2007- 224253) is mixed with rubber.

However, the above technologies have a problem in that the biodegradability of the used biodegradable materials is lowered, and thus a technology capable of further enhancing the biodegradability of the rubber composition is required.

According to one aspect of the present invention, there is provided a biodegradable rubber composition, comprising: a hydroxyalkanoate (HA) resin; peroxide crosslinking agent; And there is provided a biodegradable rubber composition comprising a rubber that can be crosslinked by the peroxide crosslinking agent.

In one embodiment, the hydroxyalkanoate resin is poly(3-hydroxypropionate), poly(4,4'-hydroxybutyrate), poly(3-hydroxyoctanoate-co-3 -hydroxyhexanoate) and poly(3-hydroxypropionate-co-4-hydroxybutyrate) may be at least one selected from the group consisting of.

In one embodiment, the hydroxyalkanoate resin may have a melting point of 100° C. or less.

In one embodiment, the crosslinkable rubber is natural rubber (NR), styrene butadiene rubber (SBR), butadiene rubber (BR), styrene butadiene styrene rubber (SBS), nitrile-butadiene rubber (NBR), ethylene-propylene Rubber (EPM), ethylene-propylenediene monomer (EPDM) rubber, silicone rubber, styrene block copolymer (SBC), 1,2-polybutadiene (1,2-PB), chlorinated polyethylene (CPE), ethylene It may be at least one selected from the group consisting of vinyl acetate rubber (EVM), and thermoplastic polyurethane elastomer (TPU).

In one embodiment, the content ratio of the hydroxyalkanoate resin and the crosslinkable rubber may be 80:20 to 30:70 by weight, respectively.

In one embodiment, the biodegradable rubber composition may further include a compatibilizer.

In one embodiment, the compatibilizer may be a rubber grafted with maleic anhydride (MAH).

The biodegradable rubber composition according to the present invention can be manufactured to have properties equal to or greater than that of conventional rubber while having biodegradability that conventional rubber does not have, and thus can minimize the environmental impact upon disposal.

Hereinafter, preferred embodiments of the present invention will be described in detail. In describing the present invention, if it is determined that a detailed description of a related known technology may obscure the gist of the present invention, the detailed description thereof will be omitted.

Since the present invention can apply various transformations and can have various embodiments, specific embodiments are illustrated and described in detail in the detailed description. However, this is not intended to limit the present invention to specific embodiments, and it should be understood to include all modifications, equivalents and substitutes included in the spirit and scope of the present invention.

The terminology used herein is used only to describe specific embodiments, and is not intended to limit the present invention. The singular expression includes the plural expression unless the context clearly dictates otherwise. In the present invention, terms such as "comprises" or "have" are intended to designate that the features, numbers, steps, operations, components, parts, or combinations thereof described in the specification exist, but one or more other features It is to be understood that this does not preclude the possibility of the presence or addition of numbers, steps, operations, components, parts, or combinations thereof.

A biodegradable rubber composition according to an aspect of the present invention includes a hydroxyalkanoate (HA) resin; peroxide crosslinking agent; and a rubber that can be crosslinked by the peroxide crosslinking agent.

The hydroxyalkanoate resin may refer to a polyhydroxyalkanoate (PHA) homopolymer and a copolymer thereof formed by polymerization of hydroxyalkanoate.

The crosslinkable rubber is natural rubber (NR), styrene-butadiene rubber (SBR), butadiene rubber (BR), styrene-butadiene styrene rubber (SBS), nitrile-butadiene rubber (NBR), ethylene-propylene rubber (EPM), ethylene -Propylene diene monomer (EPDM) rubber, silicone rubber, styrene block copolymer (SBC), 1,2-polybutadiene (1,2-PB), chlorinated polyethylene (CPE), ethylene vinyl acetate rubber (EVM) And it may be at least one selected from the group consisting of a thermoplastic polyurethane elastomer (TPU). Since the crosslinkable rubber itself is a low-hardness region, when mixed with a high-hardness HA, the hardness of the mixture can be adjusted to the hardness of the rubber region. In particular, co-crosslinking with HA can be achieved by crosslinking with peroxide.

All of the rubbers listed above as peroxide crosslinkable rubbers can be suitably used in the biodegradable rubber composition of the present invention, for example, styrene butadiene rubber (SBR), butadiene rubber (BR), styrene butadiene styrene rubber (SBS) or ethylene -Propylene diene monomer (EPDM) rubber or the like may be frequently selected in consideration of versatility and price.

The styrene butadiene rubber (SBR) is a rubber made of a copolymer of styrene and butadiene, and is mainly manufactured through solution polymerization. In the case of this SBR, the physical properties can be adjusted according to the contents of styrene and butadiene, so that rubber having various physical properties can be manufactured. In the case of the present invention, the content of styrene contained in the SBR may be 20 to 30% by weight, and within the above range, it is possible to manufacture SBR having appropriate physical properties. The physical properties of the rubber composition may be deteriorated.

The butadiene rubber (BR) is a rubber produced by polymerizing butadiene, and may exhibit various physical properties depending on the content of the Cis component. In the present invention, it is preferable to use a high-Cis butadiene rubber with high abrasion resistance, and in the case of this high-Cis butadiene rubber, it is more preferable to use a product having a Ci component content of 90% or more. When the content of the Ci component is less than 90%, it has high elasticity but may have poor abrasion resistance.

Styrene Butadiene Styrene rubber (SBS) refers to a block copolymer obtained by polymerizing styrene and butadiene in an organic solvent. SBS is widely used in asphalt modifiers, adhesives, adhesives, and the like, and recently, its use is also increasing for products requiring high wear resistance, such as shoe soles and tires. As for SBS, products having various physical properties are used and marketed depending on the content of styrene, the presence or absence of oil, viscosity, and the like, and in the present invention, it is preferable to use a product having high wear resistance. Specifically, it is preferable to use an oil-free product having a styrene content of 20 to 23 wt% for SBS of the present invention. When the styrene content in the above range has appropriate viscosity and elasticity, it can be used as a rubber, but when it is out of the above range, polymerization cannot be performed or it has a high hardness, so it may be difficult to use as a rubber.

Ethylene-propylene diene monomer (EPDM) rubber is a rubber manufactured by polymerizing ethylene and propylene. It is known as a rubber with high durability against sunlight, especially ultraviolet rays and ozone. In the case of such EPDM rubber, it is known that it has excellent storage resistance, cold resistance, heat resistance, and material resistance, and is widely used as a pavement material for roads, flooring materials, interior and exterior materials for buildings, interior and exterior materials for automobiles, and heat resistance materials. The EPDM is mainly produced by copolymerizing diene with ethylene propylene monomer (EPM) and then sulfur crosslinking, and various products are commercially sold depending on the ratio of diene, but in the present invention, 3~ having high durability and abrasion resistance It is preferred to use an EPDM comprising 6% by weight of a diene.

The hydroxyalkanoate (HA) resin is a biodegradable resin. In general, when an excessive carbon source is present and other nutrients such as phosphorus, nitrogen, magnesium, and oxygen are insufficient, microorganisms are stored therein as an energy or carbon source storage material. It is an accumulating polyester. As shown above, most hydroxyalkanoate resins are produced using microorganisms because they correspond to metabolites of microorganisms.

In addition, this hydroxyalkanoate resin is carbon-neutral compared to petroleum-derived polybutylene adipate terephthalate (PBAT), which is widely used as a biodegradable resin, and has a faster rate of natural decomposition in soil. In addition, since it is stronger and tougher than polybutylene adipate terephthalate (PBAT), it is possible to make thinner and tougher products than PBAT with a smaller amount of raw material, thereby reducing the amount of plastic used.

Various types of hydroxyalkanoate resins can be made depending on the microorganisms or raw materials used for manufacturing, and the hydroxyalkanoate resins used in the present invention have high affinity with the rubber and have appropriate physical properties. It is preferable to use hydroxyalkanoate. For example, the hydroxyalkanoate resin may be poly(3-hydroxypropionate), poly(4,4'-hydroxybutyrate), poly(3-hydroxyoctanoate-co-3-hydr It may be at least one selected from the group consisting of hydroxyhexanoate) and poly(3-hydroxypropionate-co-4-hydroxybutyrate).

The hydroxyalkanoate resin may have a melting point of 100° C. or less. When the melting point of the hydroxyalkanoate resin exceeds 100° C., the hardness of the homopolymer or copolymer used as the hydroxyalkanoate resin becomes too high, so that the hardness of the final product is too high compared to the hardness range of general-purpose rubber. As it becomes high, the rubber's functions, particularly elasticity, and electrical and ductility may be lost.

The content ratio of the HA and the crosslinkable rubber may be 80:20 to 30:70, preferably 73:27 to 35:65, more preferably 70:30 to 40:60 by weight. If the content of the HA is lower than the above, the meaning of biodegradability is lost, and if it is higher than the above, the function as a rubber may disappear due to high hardness.

The HA may be appropriately co-crosslinked with the crosslinkable rubber by using the peroxide crosslinking agent. In the case of the existing HA, there was a limit to the use of mixing because it was not compatible with the non-degradable resin. However, in the present invention, by using an additive peroxide crosslinking agent, co-crosslinking can be formed between the HA and the crosslinkable rubber, so it can be mixed and used, and it is possible to prepare a biodegradable rubber having desired physical properties. That is, by mixing the cross-linkable rubber with the HA, the physical properties of a practically usable rubber can be made by co-crosslinking.

Non-limiting examples of the peroxide crosslinking agent include t-butylperoxyisopropylcarbonate, t-butylperoxylaurylate, t-butylperoxyacetate, di-t-butylperoxyphthalate, t-dibutylper Oxymaleic acid, cyclohexanone peroxide, t-butylcumyl peroxide, t-butyl hydroperoxide, t-butylperoxybenzoate, dicumyl peroxide, 1,3-bis(t-butylperoxyisopropyl)benzene, Methyl ethyl ketone peroxide, 2,5-dimethyl-2,5-di(benzoyloxy)hexane, 2,5-dimethyl-2,5-di(t-butylperoxy)hexane, di-t-butyl peroxide , 2,5-dimethyl-2,5-(t-butylperoxy)-3-hexane, n-butyl-4, 4-bis(t-butylperoxy)valerate and a,a'-bis(t -Butyl peroxy) may be at least one selected from the group consisting of diisopropylbenzene.

On the other hand, for example, a rubber such as isobutylene isoprene rubber (IIR) is a rubber containing isobutylene and is not crosslinked by a peroxide crosslinking agent, so it may be unsuitable for use as the rubber of the present invention.

The peroxide crosslinking agent may be 0.01 to 5 parts by weight, preferably 0.1 to 3 parts by weight, and more preferably 0.5 to 2 parts by weight based on 100 parts by weight of the total of the crosslinkable rubber and the HA. If the content of the peroxide crosslinking agent is less than the above range, the degree of crosslinking is likely to be insufficient. If the content of the peroxide crosslinking agent is greater than the above range, the crosslinking is excessively performed, resulting in a lower elongation and loss of the rubber function, which may not be advantageous in terms of cost versus effectiveness.

The biodegradable rubber composition described above may further include a compatibilizer. The compatibilizer may increase the compatibility between the crosslinkable rubber component and the HA component to increase physical properties. Preferably, the compatibilizer may be a rubber grafted with maleic anhydride (MAH). Mechanical properties of the biodegradable rubber composition may be improved by grafting the maleic anhydride. The grafting ratio of the maleic anhydride may be 1 to 10 parts by weight based on 100 parts by weight of the crosslinkable rubber. In the above range, the performance of the compatibilizer is excellent.

The rubber component of the maleic anhydride-grafted rubber may be EPM, EPDM, silicone rubber, etc. having very low compatibility with HA.

The biodegradable rubber composition according to an embodiment of the present invention may further include a filler. The filler may be an inorganic filler or an organic filler. Examples of inorganic fillers include talc, calcium carbonate, zinc carbonate, wollastonite, silica, alumina, magnesium oxide, calcium silicate, sodium aluminate, calcium aluminate, sodium aluminosilicate, magnesium silicate, glass balloon, carbon black, zinc oxide, Antimony trioxide, zeolite, hydrotalcite, metal fiber, metal whisker, ceramic whisker, potassium titanate, boron nitride, graphite, glass fiber, carbon fiber, etc. can be used. Moreover, as an organic filler, polymers which exist in nature, such as starch, cellulose microparticles|fine-particles, wood flour, okara, rice husk, bran, and these modified products are mentioned. In addition, in order to increase the performance of the filler, the filler may be used as a single component or a mixture of two or more fillers may be used. In addition, even when a single filler is used, fillers having two or more sizes or physical properties may be mixed and used. Mixed use of these fillers can give new physical properties by reducing the porosity of the filler, and can also impart physical properties according to each filler to the rubber at the same time.

The filler may include 5 to 30 parts by weight based on 100 parts by weight of the total of the crosslinkable rubber and the HA. When the filler is included in less than 5 parts by weight, it is difficult to expect the effect of the filler (elasticity and strength improvement, etc.) can

In addition, if necessary, an antioxidant may be further included in the composition. The antioxidant may be included in an amount of 0.1 to 5% by weight, preferably 1.0 to 5% by weight, based on the total amount of the composition. When the amount of the antioxidant used is less than the above range, the antioxidant reaction of the product cannot be easily achieved, and when the amount exceeds the above range, there is a risk that the physical properties of the product may be lowered, so the amount of the antioxidant used is 0.1 to 5 weight. It is preferable to limit it within the range of %.

It can be molded into various products using the above-described biodegradable rubber composition. For example, it is possible to mix with a mixer such as a Banbury mixer, a kneader, an open mill, etc., make a sheet by an open mill, and perform molding by compression molding.

In addition, the biodegradable rubber composition according to an embodiment of the present invention is poly(butylene adipate-co-terephthalate) (PBAT), poly(butylene succinate-co-butylene adipate) (PBSA), which are other biodegradable plastics. ), polyalkylene isosorbide adipate-co-terephthalate (PAIAT), etc. can be compounded to control the physical properties, so that it can be processed into a more eco-friendly and highly useful product.

The rubber composition having biodegradability according to the present invention has excellent processability because it contains a peroxide crosslinkable rubber and HA resin, and the molded article manufactured therewith has excellent biodegradability in nature, and can exhibit high strength, durability, etc. .

The biodegradable rubber composition according to the present invention has a hardness of 40 to 95 Shore A, preferably 60 to 86, a tensile strength of 60 kg/cm 2 or more, preferably 82 to 170 kKg/cm 2 , and an elongation of 200% or more, preferably preferably 450 to 650%, the tear strength is 30 kg/cm or more, preferably 38 to 66 kg/cm, the rebound elasticity is 40% or more, preferably 40 to 53%, and the abrasion resistance (DIN) is 260 or less, preferably It may be 200 or less. Within the above range, the rubber composition according to the present invention may exhibit the properties of rubber, but if it is out of the above range, it may not be possible to represent the properties of the rubber or may be difficult to use due to poor durability.

In addition, the biodegradable rubber composition according to the present invention may have a biodegradation rate of 35% by weight or more, preferably 50% by weight or more, after 6 months tested by the method of ISO 14855. In the case of biodegradable rubber, the test method is not stipulated, so biodegradability can be tested using ISO 14855, a biodegradability test method for plastics, in which case the biodegradable rubber composition of the present invention has a biodegradation rate of 35 wt% or more can If the biodegradation rate is less than the biodegradability, the biodegradability may not be achieved even after a long period of time.

Hereinafter, the technology disclosed in the present specification will be described in more detail through various embodiments, but this is for convenience of description and the spirit of the claims of the technology disclosed in the present specification is not limited thereto.

Example

The following raw materials were used for the preparation of the biodegradable rubber composition of the present invention.

Rubber-1: SBR 1502 (manufactured by Kumho Petrochemical)

Rubber-2: BR 01 (manufactured by Kumho Petrochemical)

Rubber-3: EPDM 4520 (made by DOW)

Rubber-4: Butyl 268 (Isobutylene Isoprene Rubber, manufactured by Exxon)

HA homopolymer-1 (HA-1): Rinnovo 3HP H1000XP (Poly(3-hydroxypropionate) Novomer Inc., melting point 77℃

HA homopolymer-2 (HA-2): TephaFLEX P4HB (Poly(4-hydroxybutyrate) manufactured by Tepha Medical Devices, melting point 53℃

HA-co-HA copolymer-1(HACO-1): Poly(3-hydroxyoctanoate-co-3-hydroxyhexanoate), melting point 61℃

HA-co-HA copolymer-2(HACO-2): PHBH 151C (Poly(3-hydroxybutyrate-co-3-hydroxyhexanoate)), manufactured by Kaneka Corporation, melting point 126°C

Compatibilizer: KEPA 1150 (MAH grafted EPDM, manufactured by Kumho Polychem)

Peroxide: Luperox F (Di-(2-t-butylperoxyisopropyl)benzene, manufactured by ARKEMA)

Filler: N330 (Carbon Black, made by OCI)

Rubber, HA homopolymer or copolymer, compatibilizer, and filler were put in a kneader according to the mixing ratio in Tables 1 and 2, mixed at 120 ° C. for 10 minutes, and then a peroxide crosslinking agent (Peroxide) was added and mixed for 2 minutes. After the mixing was completed, it was taken out from the kneader to make a 5 mm thick sheet with an open mill, and then put into a 2 mm thick specimen mold. The specimen mold was subjected to compression molding at 185° C. for 5 minutes and cooled to obtain a specimen having a thickness of 2 mm.

Numbers related to each raw material in Tables 1 and 2 indicate parts by weight unless otherwise specified.

Example 1 Example 2 Example 3 Comparative Example 1 Example 4 Example 5 Comparative Example 2 rubber-1 40 - - - - 30 25 rubber-2 - 40 - - - - - rubber-3 - - 40 - 40 - - rubber-4 - - - 40 - - - HA-1 70 75 HA-2 - - - - - - - HACO-1 - - - - - - - HACO-2 - - - - - - - compatibilizer - - - - 5.0 - - Peroxide 0.7 0.5 1.0 2.0 1.0 0.7 0.7 Filler - - - - - - -

Example 6 Example 7 Example 8 Example 9 Comparative Example 3 Comparative Example 4 Comparative Example 5 rubber-1 50 40 40 40 70 rubber-2 - - - - - - - rubber-3 - - - - - - - rubber-4 - - - - - - - HA-1 40 50 - - - - - HA-2 - - - - - - HACO-1 - - - - - - HACO-2 - - - - 30 40 compatibilizer - - - - - - - Peroxide 0.6 0.7 0.7 0.7 0.7 0,3 0.4 Filler - 20 - - - - -

Hardness, tensile strength, elongation, tear strength, rebound elasticity, etc. generally used for measuring the physical properties of rubber were specified using the specimens prepared in the ratios of Tables 1 and 2 above. In addition, an experiment was conducted to confirm the biodegradability of the rubber, and since there is no test standard for the existing biodegradable rubber, the test was conducted by applying the method of ISO 14855, which is a test standard for biodegradable plastics, mutatis mutandis.

Example 1 Example 2 Example 3 Comparative Example 1 Example 4 Example 5 Comparative Example 2 Hardness
(Shore A) 70 70 68 bridge
no 70 86 The tensile strength
(kg/cm2) 130 120 82 - 125 170 210 elongation
(%) 550 650 - 350 tear strength
(kg/cm) 53 51 - 53 66 76 rebound elasticity
(%) 43 53 48 - 50 32 wear resistance
(DIN) 155 125 255 - 175 125 125 biodegradable
(%) 55 55 55 - 53 68 Suitability for use in biodegradable rubber fitness fitness fitness charm fitness fitness charm

Example 6 Example 7 Example 8 Example 9 Comparative Example 3 Comparative Example 4 Comparative Example 5 Hardness
(Shore A) 68 99 92 96 The tensile strength
(kg/cm2) 105 145 125 127 110 elongation
(%) 650 450 tear strength
(kg/cm) 56 50 52 35 45 rebound elasticity
(%) 52 40 45 44 30 35 40 wear resistance
(DIN) 210 130 160 152 110 210 biodegradable
(%) 36 55 55 55 27 35 Suitability for use in biodegradable rubber fitness fitness fitness fitness charm charm charm

Referring to the results of Tables 3 and 4, hardness, tensile strength, elongation, tear strength, and rebound resilience were tested according to KS M 6518, and the hardness was Shore A 40 or more and 95 or less, and the tensile strength was 60 kg/cm 2 or more, If the elongation rate was 200% or more, the tear strength was 30kg/cm or more, and the rebound elasticity was 40% or more, it was judged to be suitable for rubber use. Abrasion resistance (DIN) was tested according to KS M ISO 4649, and 200 or more is suitable for shoe soles, and there are no special specifications for other uses other than soles. Biodegradability is ISO 14855, indicating the biodegradation rate after 6 months. There is no standard for biodegradable rubber as there has been no biodegradable rubber so far. In the case of biodegradable plastics, it is certified as biodegradable when it is tested to ISO 14855 and biodegraded to 60% by weight after 45 days and 90% by weight after 6 months. Here, 90% by weight biodegradation means that 90% by weight of plastic is converted to carbon dioxide gas after 6 months.

The biodegradable rubber of the present invention does not biodegrade as much as the biodegradable plastic, but 50% by weight of the biodegradable rubber is decomposed in the ground at 50% by weight and blown away as carbon dioxide gas, and the remaining 50% by weight is split into molecular size and is present in the soil Although the undecomposed part remains, it almost restores the function of the soil, so it is worthwhile in itself.

From the above results, it can be seen that a composition in which a crosslinkable rubber, HA and a crosslinking agent are mixed can be excellently used for practical rubber applications.

As a specific part of the present invention has been described in detail above, for those of ordinary skill in the art, it is clear that this specific description is only a preferred embodiment, and the scope of the present invention is not limited thereby. will be. Accordingly, it is intended that the substantial scope of the present invention be defined by the appended claims and their equivalents.

Claims (7)

A biodegradable rubber composition comprising:
hydroxyalkanoate (HA) resins;
peroxide crosslinking agent; and
a rubber that can be crosslinked by the peroxide crosslinking agent;
includes,
A biodegradable rubber composition wherein the content ratio of the hydroxyalkanoate resin and the crosslinkable rubber is 80:20 to 30:70 by weight, respectively. The method of claim 1,
The hydroxyalkanoate resin is poly(3-hydroxypropionate), poly(4,4'-hydroxybutyrate), poly(3-hydroxyoctanoate-co-3-hydroxyhexanoate) ) and poly (3-hydroxypropionate-co-4-hydroxybutyrate) at least one selected from the group consisting of a biodegradable rubber composition. According to claim 1,
The hydroxyalkanoate resin has a melting point of 100 ℃ or less biodegradable rubber composition. According to claim 1,
The crosslinkable rubber is natural rubber (NR), styrene-butadiene rubber (SBR), butadiene rubber (BR), styrene-butadiene styrene rubber (SBS), nitrile-butadiene rubber (NBR), ethylene-propylene rubber (EPM), ethylene -Propylenediene monomer (EPDM) rubber, silicone rubber, styrene block copolymer (SBC), 1,2-polybutadiene (1,2-PB), chlorinated polyethylene (CPE), ethylene vinyl acetate rubber (EVM) , and a biodegradable rubber composition of at least one selected from the group consisting of a thermoplastic polyurethane elastomer (TPU). delete According to claim 1,
The biodegradable rubber composition is a biodegradable rubber composition that further comprises a compatibilizer. The biodegradable rubber composition of claim 6, wherein the compatibilizer is a rubber grafted with maleic anhydride (MAH).