KR20230063910A - Thermoplastic polyester elastomer resin composition comprising spent coffee ground and article comprising the same - Google Patents

Abstract

The present invention relates to a thermoplastic polyester-based elastomer resin composition containing coffee waste and a molded product containing the same, and more particularly, to a thermoplastic polyester-based elastomer (TPEE) resin in which coffee waste and a chain extender are introduced in a specific content ratio By adding a foaming agent having a high decomposition temperature, the present invention relates to a thermoplastic polyester elastomer resin composition having improved foaming force and mechanical properties and at the same time utilizing waste coffee waste, which is environmentally friendly and has improved economic feasibility, and a molded product including the same. .

Description

Thermoplastic polyester elastomer resin composition comprising coffee grounds and a molded article comprising the same

The present invention relates to a thermoplastic polyester-based elastomer resin composition containing coffee waste and a molded product containing the same, and more particularly, to a thermoplastic polyester-based elastomer (TPEE) resin in which coffee waste and a chain extender are introduced in a specific content ratio By adding a foaming agent having a high decomposition temperature, the present invention relates to a thermoplastic polyester elastomer resin composition having improved foaming force and mechanical properties and at the same time utilizing waste coffee waste, which is environmentally friendly and has improved economic feasibility, and a molded product including the same. .

Thermoplastic polyester elastomer resin is used in various forms throughout industries such as electric and electronic, biomaterials, and automobiles based on its excellent heat resistance, chemical resistance, and durability, and is replacing existing materials. In particular, thermoplastic polyester-based elastomer resins are in the limelight for their eco-friendliness and reusability because they do not use crosslinking agents and catalysts unlike rubber materials when formulated.

However, the use of thermoplastic polyester elastomer resin as a shoe material is limited due to insufficient foaming power compared to rubber materials. Existing methods for improving the foaming power of elastomer resins largely include olefin-based elastomer resin composition including a foaming agent (e.g., Korean Patent No. 10-2244314) and urethane production through curing and molding processes (e.g., Korean Patent No. 10). -2291202). The former patent requires a prior process for crosslinking, and also has the disadvantage of requiring a physical foam injection molding machine that requires a large investment. There is a disadvantage that the selectivity of the product design according to the product is low.

On the other hand, coffee is a tropical plant that is a popular drink among people and is an agricultural product produced throughout the year, so it has abundant raw materials and smooth supply. In particular, the size of the coffee market in Korea is 160,000 tons per year, showing a continuous increase. However, according to this, the amount of coffee grounds (also called 'coffee grounds' or 'waste coffee grounds') (spent coffee grounds or coffee waste) discarded after brewing coffee is 160,000 tons per year, which is applied to animal feed or farms. There is a problem that the demand for recyclables using coffee waste is low and the processing process is also difficult, so the frequency of use is low.

An object of the present invention is to improve the foaming power and mechanical properties that can be used as a shoe material without the use of a vulcanization process, crosslinking agent, catalyst, etc. required in existing rubber materials or olefin-based materials, and without additional processes such as binding or curing. It is to provide an expandable thermoplastic polyester elastomer resin composition that exhibits physical properties and can greatly improve eco-friendliness and economic feasibility by utilizing coffee waste, which is entirely discarded and discarded, and a molded product including the same.

The present invention to solve the above problems, (1) thermoplastic polyester elastomer; (2) coffee grounds; (3) chain extenders; And (4) a foaming agent; the content of the coffee grounds is 10.5 to 30 parts by weight based on 100 parts by weight of the total composition, the content of the chain extender is 0.55 to 2.5 parts by weight based on 100 parts by weight of the total composition , The decomposition temperature of the foaming agent is 215 ℃ to 245 ℃, provides an expandable thermoplastic polyester elastomer resin composition.

According to another aspect of the present invention, a molded article comprising the expandable thermoplastic polyester elastomer resin composition of the present invention is provided.

In one embodiment, the molded article is made by injection molding.

More specifically, the molded article is a shoe sole.

The expandable thermoplastic polyester elastomer resin composition of the present invention exhibits improved foaming force and mechanical properties, so it is particularly suitable for use in shoe soles, and injection molding is easy, so that the manufacturing of shoe soles limited to conventional press molding does not require an additional process. By making it possible, it is possible to provide an effect of reducing production time and thereby reducing production cost. In addition, the use of vulcanization process, crosslinking agent, catalyst, etc. required in existing rubber materials or olefin-based materials is unnecessary, and eco-friendliness and economic efficiency can be greatly improved by using coffee waste, which is completely discarded, for upcycling. In addition, since it does not require processes such as binding or curing, it has the advantage of giving developers high design selectivity.

1 is photographs of cross-sections of foamed specimens prepared in Examples and Comparative Examples of the present invention.

Hereinafter, the present invention will be described in more detail.

The resin composition of the present invention includes a thermoplastic polyester elastomer (TPEE).

The thermoplastic polyester elastomer usable in the present invention is a thermoplastic block copolymer having a hard hard segment and a soft soft segment.

In one embodiment, the hard segment may be prepared by polymerizing an aromatic dicarboxylic compound and a diol compound.

In one embodiment, the aromatic dicarboxylic compound is terephthalic acid (TPA), isophthalic acid (IPA), 1,5-naphthalenedicarboxylic acid (1,5-naphthalenedicarboxylic acid, 1,5 -NDCA), 2,6-naphthalenedicarboxylic acid (2,6-NDCA), dimethyl terephthalate (DMT), dimethyl isophthalate, or a combination thereof may be used, preferably DMT is used.

In one embodiment, a linear or cyclic aliphatic diol having 2 to 8 carbon atoms is used as the diol compound. As such aliphatic diol, ethylene glycol, propylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,4-cyclohexanedimethanol, or a combination thereof may be used, preferably. Preferably 1,4-butanediol is used.

In one embodiment, a polyalkylene oxide polymer unit may be used as the soft segment.

In one embodiment, polyoxyethylene glycol, polyoxypropylene glycol, polyoxytetramethylene glycol (hereinafter referred to as PTMEG) or a combination thereof may be used as the polyalkylene oxide, , preferably PTMEG is used.

In addition, in order to increase the melt strength of the thermoplastic polyester elastomer to improve the stability of the TPEE strand during TPEE production, thereby increasing productivity, a branching agent may be additionally used in the production of TPEE. Glycerol, pentaerythritol, neopentylglycol, or a combination thereof may be used as the branching agent, and glycerol is preferably used. In addition, the preparation of TPEE can be carried out in the presence of a suitable catalyst (eg, tetra-n-butoxy titanium (TBT)).

In general, the thermoplastic polyester elastomer may be prepared by introducing the above components into a reactor and then performing melt polymerization consisting of two steps of oligomerization and polycondensation. The oligomerization reaction is carried out at 140 to 215 ° C for 3 to 4 hours, and the polycondensation reaction proceeds with stepwise pressure reduction from 760 torr to 0.3 torr at 210 to 250 ° C for 4 to 5 hours to prepare a branched elastomer. do.

The soft segment content in 100% by weight of the thermoplastic polyester elastomer resin may vary, for example, in the range of 5 to 75% by weight, in particular, considering blow molding processability, mechanical strength, flexibility, etc., 30 to 70 It is preferred that it is % by weight. If the content of the soft segment in the thermoplastic polyester elastomer resin is too small, it is difficult to expect flexibility due to high hardness. Conversely, if it is too large, it is difficult to expect high heat resistance.

In one embodiment, the thermoplastic polyester elastomer may have an intrinsic viscosity of 1.3 to 3 dl/g, more specifically 1.5 to 2.5 dl/g, and Shore hardness A-70 to A-90. , More specifically, it may have A-70 to A-80.

In one embodiment, the resin composition of the present invention may include 70 to 88 parts by weight of the thermoplastic polyester elastomer based on 100 parts by weight of the total composition. If the content of the thermoplastic polyester elastomer in the resin composition is less than the above level, the hardness and mechanical properties of a molded article manufactured using the same may be deteriorated. Foaming properties may deteriorate.

More specifically, the content of the thermoplastic polyester elastomer in 100 parts by weight of the resin composition of the present invention is 70 parts by weight or more, 71 parts by weight or more, 72 parts by weight or more, 73 parts by weight or more, 74 parts by weight or more, or 75 parts by weight or more. 88 parts by weight or less, 87 parts by weight or less, 86 parts by weight or less, 85 parts by weight or less, 84 parts by weight or less, 83 parts by weight or less, 82 parts by weight or less, 81 parts by weight or less, or 80 parts by weight or less However, it is not limited thereto.

The resin composition of the present invention also includes coffee grounds.

In the present invention, 'coffee waste' is a by-product remaining after extracting coffee liquid by boiling coffee bean powder during coffee production, and in the present specification, it has the same meaning as 'coffee grounds' or 'waste coffee powder' used

In one embodiment, the coffee waste included in the thermoplastic resin composition of the present invention has a moisture content of 1.5% by weight or less. If the water content of the coffee waste exceeds 1.5% by weight of the total weight of the coffee waste (100% by weight), decomposition of the resin component during processing of the resin composition may cause deterioration in mechanical properties or deterioration in appearance.

In one embodiment, the water content of the coffee grounds may be 0.05% by weight or less, more specifically 0.03% by weight or less, and more specifically 0.01% by weight or less. If the moisture content of coffee waste is higher than the above level, mold may be cultured, making storage difficult and physical properties degraded. The lower limit of the water content of the coffee waste is not particularly limited, and considering the economics and efficiency of the coffee waste drying operation, it may be, for example, 0.001% by weight or more or 0.002% by weight or more, but is not limited thereto. The moisture content of the above-described coffee waste may be obtained through, for example, drying conditions of 4 hours or more at 130 ° C., but is not limited thereto.

The resin composition of the present invention includes 10.5 to 30 parts by weight of the coffee grounds based on 100 parts by weight of the total composition. If the coffee ground content in 100 parts by weight of the resin composition is less than 10.5 parts by weight, the foamability of the composition is deteriorated because it does not have a morphology having a pore structure favorable for foaming. As this is relatively reduced, the hardness and mechanical properties of the molded product may be deteriorated.

More specifically, the coffee grounds content in 100 parts by weight of the resin composition of the present invention may be 10.5 parts by weight or more, 11 parts by weight or more, 12 parts by weight or more, 13 parts by weight or more, 14 parts by weight or more, or 15 parts by weight or more , It may also be 30 parts by weight or less, 29 parts by weight or less, 28 parts by weight or less, 27 parts by weight or less, 26 parts by weight or less, or 25 parts by weight or less, but is not limited thereto.

The resin composition of the present invention also contains a chain extender.

In one embodiment, the chain extender may be an isocyanate-based compound, an isocyanurate-based compound, a glycidyl-based compound, an amine-based compound, a carbodiimide-based compound, maleic anhydride, or a mixture thereof, more preferably may be an isocyanate-based compound, an isocyanurate-based compound, a glycidyl-based compound, or a mixture thereof, but is not limited thereto.

The resin composition of the present invention includes 0.55 to 2.5 parts by weight of the chain extender based on 100 parts by weight of the total composition. If the chain extender content in 100 parts by weight of the resin composition is less than 0.55 parts by weight, the foaming gas trap effect is insufficient due to low cell stability, and the foaming force of the composition is deteriorated. hardness and mechanical properties may deteriorate.

More specifically, the chain extender content in 100 parts by weight of the resin composition of the present invention may be 0.55 parts by weight or more, 0.6 parts by weight or more, 0.65 parts by weight or more or 0.7 parts by weight or more, and also 2.5 parts by weight or less, 2 parts by weight parts by weight or less, 1.8 parts by weight or less, 1.5 parts by weight or less, or 1.2 parts by weight or less, but is not limited thereto.

The resin composition of the present invention also includes a blowing agent having a decomposition temperature of 215°C to 245°C.

If the decomposition temperature of the foaming agent is less than 215 ° C, the composition may not exhibit sufficient foaming power due to the gas already diffused in the processing process.

In one embodiment, the decomposition temperature of the blowing agent may be 215 ° C or higher, 217 ° C or higher, 220 ° C or higher, 222 ° C or higher or 225 ° C or higher, and also 245 ° C or lower, 243 ° C or lower, 240 ° C or lower, 238 ° C or lower or It may be 235 ℃ or less, but is not limited thereto. In addition, the gas amount of the foaming agent may be 150 to 250 ml/g, but is not limited thereto.

In one embodiment, the blowing agent may be at least one selected from the group consisting of dinitrosopentamethylenetetramine, oxybisbenzenesulfonyl hydrazide, toluenesulfonyl semicarbazide, and pentyl tetrazole, preferably It may be toluenesulfonyl semicarbazide.

In one embodiment, the resin composition of the present invention may include 0.5 to 1.5 parts by weight of the foaming agent based on 100 parts by weight of the total composition. If the content of the foaming agent in the resin composition is less than the above level, the foamability of the composition may be deteriorated, and conversely, if the content of the foaming agent in the resin composition exceeds the above level, mechanical properties of the molded article may be deteriorated.

More specifically, the content of the blowing agent in 100 parts by weight of the resin composition of the present invention may be 0.5 parts by weight or more, 0.6 parts by weight or more, 0.7 parts by weight or more, or 0.8 parts by weight or more, and also 1.5 parts by weight or less, 1.4 parts by weight or less. , 1.3 parts by weight or less or 1.2 parts by weight or less, but is not limited thereto.

The resin composition of the present invention may further include one or more other additives in addition to the above components, in particular, one or more other additives commonly added to thermoplastic resin compositions for injection molding. Such other additives include, for example, a hydrolysis-resistant agent, a UV stabilizer, an antioxidant, a heat stabilizer, a nucleating agent, carbon black, a carbon black masterbatch, and the like, and these may be used alone or in a mixture of two or more. .

The content of the other additives is not particularly limited, and may be used in an amount that can be used to add additional functions within a range that does not impair desired physical properties of the resin composition of the present invention. For example, the content of each of the other additives may be 0.1 to 5 parts by weight, more specifically 0.2 to 3 parts by weight, 0.5 to 2.5 parts by weight, or 1 to 2.5 parts by weight based on 100 parts by weight of the resin composition of the present invention. It may be negative, but is not particularly limited thereto.

According to another aspect of the present invention, a molded article comprising the resin composition of the present invention is provided.

In a preferred embodiment, the molded article is prepared by injection molding the resin composition of the present invention.

Also in a preferred embodiment, the molded article is a shoe sole.

Hereinafter, the present invention will be described in more detail through Examples and Comparative Examples. However, the scope of the present invention is not limited to these examples.

[Example]

Preparation Example 1: Preparation of Shore Hardness A-75 TPEE

16.99 parts by weight of dimethyl terephthalate (DMT), 6.10 parts by weight of 1,4-butanediol, 74.55 parts by weight of polyoxytetramethylene glycol (PTMEG) having a molecular weight of 2,000, and 0.065 part by weight of glycerol were placed in a reactor and tetra-n-butoxytitanium as a catalyst. (TBT) 0.03 part by weight was added. The temperature in the reactor was raised from 140 ° C to 215 ° C for 120 minutes to carry out the ester substitution reaction, and the ester substitution reaction was carried out for an additional 120 minutes while maintaining the temperature at 215 ° C. The ester substitution reaction was terminated at the time of 99% or more. Thereafter, 0.04 parts by weight of TBT as a catalyst and 0.07 parts by weight of a heat stabilizer (Irganox 1010) were added to perform a polycondensation reaction. The polycondensation reaction was carried out by raising the temperature from 215 ° C to 250 ° C for 120 minutes, and was carried out for an additional 120 minutes while maintaining the temperature at 250 ° C. At this time, the pressure was reduced from 760 torr to 0.3 torr for 1 hour, and the remaining 3 hours at 0.3 torr or less. TPEE having Shore hardness-A 75 was prepared by adjusting the final pressure to 0.3 torr or less under vacuum conditions. The intrinsic viscosity of the elastomer thus prepared was 2.19 dl/g as measured in a solvent of phenol/tetrachloroethane (TCE) = 50/50.

Preparation Example 2: Extrusion

According to the composition shown in Table 1 below, TPEE of shore hardness A-75 prepared in Preparation Example 1 and the remaining components were mixed and extruded by introducing into a twin screw extruder. The temperature of the extruder was extruded by setting the hopper part to 120 degrees and the remaining parts to 150 to 190 degrees, and a twin screw (L / D = 40) was used, the diameter of the die was 26 phi, and the kneading block 2 pieces of silver were used. The feed rate of the resin was 10 kg/hr to 14 kg/hr, and the rotational speed of the extruder screw was extruded at 150 rpm to 200 rpm.

Thereafter, the resin composition subjected to the extrusion process was cooled in a cooling tank, and then pelletized to prepare thermoplastic elastomer resin pellets.

[Table 1]

<Ingredient Description>

TPEE: Thermoplastic polyester elastomer prepared in Preparation Example 1

Coffee waste: Coffee waste after brewing coffee (Ediya Coffee)

Antioxidant: Irganox 1010 (Asahi Kasei)

Heat stabilizer: PEP36 (Adeka)

Nucleating agent: Licomont NaV101 (Client)

Chain extender A: glycidyl chain extender (MTE-N005ET, Cosmopolytec)

Chain extender B: Isocyanurate-based chain extender (Duranate TLA-100, Asahi Kasei)

Foaming agent A: Azodicarbonamide (decomposition temperature: 202-208℃, Unicell-D600MT, Dongjin Semichem)

Foaming agent B: p-toluenesulfonyl semicarbazide (decomposition temperature: 225 ~ 235 ℃, pTSS, Geumyang)

A standard test piece was prepared by injecting the thermoplastic polyester elastomer resin compositions prepared as described above, and then the following items were measured and shown in Table 2, and a cross section of the foamed test piece was photographed and shown in FIG.

(1) Hardness: evaluated according to ASTM D2240.

(2) Specific gravity: evaluated according to ASTM D792.

(3) Tensile strength: evaluated according to ASTM D638.

(4) Tensile elongation: evaluated according to ASTM D638.

[Table 2]

As confirmed from Table 2 and FIG. 1, all of the compositions of Examples according to the present invention exhibited improved foaming force and excellent tensile strength. On the other hand, compared to the examples, the compositions of the comparative examples lacked foaming power, and as a result, the hardness and specific gravity were increased, making them unsuitable for use as shoe soles, and the tensile strength was also poorer.

Claims (8)

(1) thermoplastic polyester elastomers;
(2) coffee grounds;
(3) chain extenders; and
(4) a foaming agent;
The content of the coffee grounds is 10.5 to 30 parts by weight based on 100 parts by weight of the total composition,
The content of the chain extender is 0.55 to 2.5 parts by weight based on 100 parts by weight of the total composition,
The decomposition temperature of the blowing agent is 215 ℃ to 245 ℃,
An expandable thermoplastic polyester elastomer resin composition. The expandable thermoplastic polyester elastomer resin composition according to claim 1, wherein the thermoplastic polyester elastomer has an intrinsic viscosity of 1.3 to 3 dl/g and a shore hardness of A-70 to A-90. The expandable thermoplastic polyester elastomer resin composition according to claim 1, wherein the coffee grounds have a water content of 0.05% by weight or less. The expandable thermoplastic polyester elastomer according to claim 1, wherein the chain extender is an isocyanate-based compound, an isocyanurate-based compound, a glycidyl-based compound, an amine-based compound, a carbodiimide-based compound, maleic anhydride, or a mixture thereof. resin composition. The foamable thermoplastic polyester system according to claim 1, wherein the foaming agent is at least one selected from the group consisting of dinitrosopentamethylenetetramine, oxybisbenzenesulfonyl hydrazide, toluenesulfonyl semicarbazide, and pentyl tetrazole. An elastomeric resin composition. A molded article comprising the expandable thermoplastic polyester elastomer resin composition according to any one of claims 1 to 5. 7. The molded article according to claim 6, wherein the molded article is produced by injection molding. 7. The molded article according to claim 6, wherein the molded article is a shoe sole.

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