KR20220077293A - Thermoplastic polyester elastomer resin composition suitable for footwear outsole and molded article comprising the same - Google Patents

Abstract

The present invention relates to a thermoplastic polyester-based elastomer resin composition and a molded article comprising the same, and more particularly, to a thermoplastic polyurethane (TPU) or styrene-ethylene-butadiene-styrene (TPU) together with a thermoplastic polyester-based elastomer (TPEE) resin ( SEBS) copolymer, it is excellent in abrasion resistance and traction, and injection molding is easy, so it relates to a thermoplastic polyester-based elastomer resin composition suitable for shoe sole use, and a molded article including the same.

Description

Thermoplastic polyester elastomer resin composition suitable for footwear outsole and molded article comprising the same

The present invention relates to a thermoplastic polyester-based elastomer resin composition and a molded article comprising the same, and more particularly, to a thermoplastic polyurethane (TPU) or styrene-ethylene-butadiene-styrene (TPU) together with a thermoplastic polyester-based elastomer (TPEE) resin ( SEBS) copolymer, it is excellent in abrasion resistance and traction, and injection molding is easy, so it relates to a thermoplastic polyester-based elastomer resin composition suitable for shoe sole use, and a molded article including the same.

Existing technologies for improving the abrasion resistance and traction of shoe soles are mostly about the sole structure and molding method rather than the material itself.

The most commonly used material for shoe soles is carbon rubber made of a mixture of carbon and rubber, such as tires. While this carbon rubber has excellent gripping power, it has the disadvantage of breaking off carbon bonds due to the action of continuous stress. This leaves a carbon footprint.

In addition, synthetic rubber is supplied as a solid form in the form of a hexahedron or film, so an additional process is required for injection molding and direct injection is difficult. there is a problem with In addition, the durability is the worst when gum-type rubber is applied to maximize traction improvement.

In Korean Patent Laid-Open Patent No. 10-2006-0092457, an attempt was made to improve abrasion resistance through a composition in which styrene-based thermoplastic rubber and polystyrene were mixed, but the durability of polystyrene itself is poor, and high-impact polystyrene (HIPS) is used to compensate for this. As the flexural modulus of elasticity increases, fatigue builds up in the foot, which reduces the wearing comfort.

In Korean Patent Laid-Open No. 10-2014-0014464, an attempt was made to improve abrasion resistance and slip resistance while reducing hardness through a composition in which a thermoplastic urethane elastomer and ethylene propylene diene copolymer (EPDM) were mixed, but this was due to the double bond of EPDM. Compatibility with urethane is not good, a process of making solid EPDM into an easy-to-input form is additionally required, and recycling is difficult due to the addition of fillers and oil.

Therefore, it is excellent in abrasion resistance and traction, and injection molding is possible, so the development of a material suitable for use as a shoe sole and also recyclable is being requested.

An object of the present invention is that it has excellent abrasion resistance and traction, and is suitable for use as a shoe sole because of easy injection molding, and at the same time does not require an additional process when processing into a shoe sole, and does not require adhesives and stitching when adhering to a midsole. , to provide a recyclable thermoplastic polyester-based elastomer resin composition and a molded article comprising the same.

In order to solve the above problems, the present invention provides a thermoplastic polyester-based elastomer resin composition, comprising: (1) a first component that is a thermoplastic polyester-based elastomer resin; and (2) a second component that is a thermoplastic polyurethane or a styrene-ethylene-butadiene-styrene copolymer, wherein the content of the second component is 10 to 45% by weight, based on 100% by weight of the total composition. A polyester-based elastomer resin composition is provided.

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

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

More specifically, the molded article is a shoe sole.

The thermoplastic polyester-based elastomer resin composition of the present invention is particularly suitable for shoe sole use, has excellent abrasion resistance and traction, and is easy to injection molding. By making this possible, it is possible to shorten the production time and thereby reduce the production cost, and since it does not require adhesive and sewing when bonding to the midsole, environmental issues such as the use of adhesive and non-recyclability, which are problems with existing natural rubber materials It can also be solved.

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

The resin composition of the present invention includes a thermoplastic polyester-based elastomer (TPEE) resin as a first component.

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

The hard segment may be prepared by polymerizing an aromatic dicarboxyl compound and a diol compound.

Examples of the aromatic dicarboxyl compound include terephthalic acid (TPA), isophthalic acid (IPA), 1,5-dinaphthalenedicarboxylic acid (1,5-NDCA), 2,6-dinaphthalenedicarboxylic acid (2,6-NDCA), dimethyl terephthalate (DMT), dimethyl isophthalate, or a combination thereof may be used. , preferably DMT.

As the diol compound, a linear or cyclic aliphatic diol having 2 to 8 carbon atoms is used. As the 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.

As the soft segment, a polyalkylene oxide polymerization unit may be used.

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

In addition, in order to increase the melt strength of the thermoplastic polyester-based elastomer resin 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. . As the branching agent, glycerol, pentaerythritol, neopentylglycol, or a combination thereof may be used, 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-based elastomer resin that can be used in the present invention can be prepared through melt polymerization consisting of two steps of an oligomerization reaction and a polycondensation reaction after the above-mentioned components are put into a reactor. The oligomerization reaction is carried out at 140-215° C. for 3 to 4 hours, and the polycondensation reaction is performed at 210 to 250° C. for 4-5 hours at a stepwise pressure reduction from 760 torr to 0.3 torr to produce a branched elastomer. do.

The soft segment content in 100% by weight of the thermoplastic polyester-based elastomer resin that can be used in the present invention may vary, for example, may be in the range of 5 to 75% by weight, in particular, considering blow molding processability, mechanical strength, flexibility, etc. If yes, it is preferably 30 to 70% by weight. If the content of the soft segment in the thermoplastic polyester-based elastomer resin is too small, it is difficult to expect flexibility due to high hardness.

The thermoplastic polyester-based elastomer resin that can be used in the present invention preferably has an intrinsic viscosity of 1.3 to 2.0 dl/g, and more preferably, may have an intrinsic viscosity of 1.3 to 1.8 dl/g. In addition, the thermoplastic polyester-based elastomer that can be used in the reaction extrusion preferably has a shore hardness of D-20 to D-40, more preferably a shore hardness of D-20 to D-29, D-22 to D-29, D-24 to D-29, or D-24 to D-28.

In one embodiment, the resin composition of the present invention may include, for example, 50 to 90% by weight of the thermoplastic polyester-based elastomer resin, based on 100% by weight of the total composition. If the content of the thermoplastic polyester-based elastomer resin in the resin composition of the present invention is less than the above level, the composition does not meet the required properties for shoe sole use, and in particular, the hardness and cushioning feeling are inferior. Conversely, when the above level is exceeded, the content of the thermoplastic polyurethane and/or styrene-ethylene-butadiene-styrene copolymer, which are other essential components, may be relatively reduced, and the abrasion resistance and gripping force of the composition may deteriorate.

More specifically, the content of the thermoplastic polyester-based elastomer resin in 100% by weight of the resin composition of the present invention may be 52% by weight or more, 55% by weight or more, 60% by weight or more, 65% by weight or more, or 70% by weight or more. , may also be 90 wt% or less, 88 wt% or less, 85 wt% or less, 83 wt% or less, or 80 wt% or less, but is not limited thereto.

In one embodiment, the resin composition of the present invention may include thermoplastic polyurethane (TPU) as the second component.

The thermoplastic polyurethane includes a structural unit derived from a polyol and a structural unit derived from a polyisocyanate.

In one embodiment, the polyol has an average number of active hydrogens of 2 or more (preferably 2 to 4) and an active hydrogen equivalent of 600 to 7,000, which is commonly used in the production of polyurethane.

More specifically, the polyol may be selected from the group consisting of polycaprolactone diol, polyether polyol, polyester polyol, a polymer polyol obtained by polymerizing these polyols and a vinyl compound, or a combination thereof. As the vinyl compound, acrylonitrile, styrene (stylene), methylmethacrylonitrile, and the like are widely used and generally, acrylonitrile may be used alone or in combination with styrene (stylene). .

The content of the polyol component included as a polymer constituent unit in the thermoplastic polyurethane may be 10 moles to 90 moles, more specifically 20 moles to 80 moles, based on 100 moles of the total polymer constituent units, but is not limited thereto. .

In one embodiment, as the polyisocyanate, aliphatic polyisocyanate, cycloaliphatic polyisocyanate, araliphatic polyisocyanate, aromatic polyisocyanate, heterocyclic polyisocyanate, or mixtures thereof may be used. Unmodified polyisocyanates or modified polyisocyanates may also be used.

In one embodiment, the polyisocyanate is methylene diisocyanate, ethylene diisocyanate, 1,4-tetramethylene diisocyanate, 1,5-pentamethylene diisocyanate, 1,6-hexamethylene diisocyanate, 1-12-dodecane Diisocyanate, cyclobutane-1,3-diisocyanate, cyclohexane-1,3-diisocyanate, cyclohexane-1,4-diisocyanate, isophorone diisocyanate, 2-4-hexahydrotoluene diisocyanate, 2.6- Hexahydrotoluene diisocyanate, dicyclohexylmethane-4,4'-diisocyanate (HMDI), 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, 2,4-toluene diisocyanate, 2, 6-toluene diisocyanate, diphenylmethane-2,4'-diisocyanate, diphenylmethane-4,4'-diisocyanate, polydiphenylmethane diisocyanate, naphthalene-1,5-diisocyanate, or 2 of these It may be a mixture of more than one species.

The content of the polyisocyanate component included as a polymer constituent unit in the thermoplastic polyurethane may be 10 moles to 90 moles, more specifically 20 moles to 80 moles, based on 100 moles of the total polymer constituent units, but is not limited thereto. does not

In one embodiment, the thermoplastic polyurethane may be an aliphatic thermoplastic polyurethane. In the case of aromatic thermoplastic polyurethane, it may not be suitable for use as a shoe sole because of its poor weather resistance. More specifically, the thermoplastic polyurethane may be a non-yellowing aliphatic thermoplastic polyurethane.

In another embodiment, the resin composition of the present invention may include a styrene-ethylene-butadiene-styrene (SEBS) copolymer as the second component.

In one embodiment, the styrene-ethylene-butadiene-styrene copolymer may have a Shore-A hardness of 70 to 80 and a flowability of 10 to 15 g/min (230° C., 10 kg load). .

In one embodiment, the styrene-ethylene-butadiene-styrene copolymer may not include mineral oil. Most commonly used SEBS copolymers contain mineral oil, but when a SEBS copolymer containing mineral oil is used, the oil leaks and the gripping force of the shoes decreases, so it may not be suitable for use as a shoe sole.

The resin composition of the present invention includes 10 to 45% by weight of the second component based on 100% by weight of the total composition. If the content of the second component in the resin composition of the present invention is less than the above level, the abrasion resistance and traction of the composition are deteriorated. There is a problem that it puts strain on the ankle when used as a sole.

More specifically, the content of the second component in 100% by weight of the resin composition of the present invention may be 10% by weight or more, 12% by weight or more, 15% by weight or more, 17% by weight or more, or 20% by weight or more, and also 45% by weight or more. % or less, 43 wt% or less, 40 wt% or less, 38 wt% or less, 35 wt% or less, 33 wt% or less, 30 wt% or less, 28 wt% or less, or 25 wt% or less .

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 the thermoplastic resin composition for injection molding. Such other additives may include, for example, a hydrolysis resistance agent, a UV stabilizer, an antioxidant, a heat stabilizer, carbon black, a carbon black masterbatch, and the like, and these may be used alone or as a mixture of two or more thereof.

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

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

In a preferred embodiment, the molded article is manufactured 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]

Examples 1 to 6 and Comparative Examples 1 to 9

The components shown in Table 1 and Table 2 were mixed according to their respective contents, and then melt-kneaded and extruded using a twin-screw extruder, cooled in a cooling bath, and then pelletized to prepare pellets. Specifically, the raw materials were mixed and put into the hopper of the extruder, and the temperature of the extruder was extruded at 150° C. for the hopper portion and 170 to 210° C. for the rest of the extruder. A twin screw (L/D=40) was used, and the extrusion conditions were: a die diameter of 26 phi, two kneading blocks (2-zone), and a feed rate of 10 according to the thickness and cutting of the strands. ~15 kg/hr, the extruder screw rotation speed was 150-250 rpm.

[Raw Ingredients Used]

TPEE-A: Shore hardness 24D thermoplastic polyester-based elastomer resin (TRIEL 5240NA, Samyang Corporation)

TPEE-B: Shore hardness 28D thermoplastic polyester-based elastomer resin (TRIEL 5280NA, Samyang Corporation)

TPEE-C: Shore hardness 30D thermoplastic polyester elastomer resin (TRIEL 5300NA, Samyang Corporation)

TPU: Non-yellowing aliphatic thermoplastic polyurethane (STA-77N, Daeyeon Materials)

SEBS-1: Styrene-ethylene-butadiene-styrene copolymer without mineral oil (AF-2130, Webs Corporation)

SEBS-2: Styrene-ethylene-butadiene-styrene copolymer with mineral oil (Taipol6151, TSRC)

Hydrolysis-resistant agent: 1,3-PBO (Evonik)

Others: UV stabilizer, antioxidant, heat stabilizer

Carbon Black Masterbatch: BK-A (Woosung Chemical)

[Table 1]

[Table 2]

The following physical properties were measured for the prepared thermoplastic polyester-based elastomer resin composition, and the results are summarized in Table 2 below.

[Physical properties and measurement method]

(1) Hardness (Shore A): It was evaluated based on ISO 868.

(2) Tear strength (kg _f /cm): It was evaluated according to ISO 34-1.

(3) Specific gravity: evaluated according to ISO 1183.

(4) Abrasion resistance (mg loss/1000 cycle): The reduced weight was measured using a Taber (H-18). The higher the number, the lower the wear resistance.

(5) Grip force: The dynamic friction coefficient was measured using a universal testing machine (UTM), and the higher the value, the higher the traction force.

[Table 3]

[Table 4]

From Table 3 above, the thermoplastic polyester-based elastomer resin composition (Examples 1 to 6) of the present invention passed the pass criteria in all evaluated items, and had mechanical properties suitable for use in shoe soles, and at the same time had abrasion resistance and traction. It can be seen that improved

On the other hand, the compositions of Comparative Examples 1 and 2 did not pass the pass criteria in all items of tear strength, abrasion resistance and traction, and the compositions of Comparative Examples 3 and 4 did not meet the pass criteria due to their high hardness, and Comparative Example 5 And the compositions of 6 did not meet the standards in hardness, specific gravity, or wear resistance, the compositions of Comparative Examples 7 and 8 did not meet the passing standards in hardness, abrasion resistance, and traction, and the composition of Comparative Example 9 had significantly lower traction. was able to confirm

Claims (8)

(1) a first component that is a thermoplastic polyester-based elastomer resin; and
(2) a second component that is a thermoplastic polyurethane or a styrene-ethylene-butadiene-styrene copolymer;
The content of the second component is, based on 100% by weight of the total composition, 10 to 45% by weight,
A thermoplastic polyester-based elastomer resin composition. The composition according to claim 1, wherein the thermoplastic polyester-based elastomer resin is an elastomer resin having a shore hardness of 24 to 29D. The thermoplastic polyester-based elastomer resin composition according to claim 1, wherein the thermoplastic polyurethane comprises a structural unit derived from a polyol and a structural unit derived from a polyisocyanate. The thermoplastic polyester-based elastomer resin composition according to claim 1, wherein the thermoplastic polyurethane is a non-yellowing aliphatic thermoplastic polyurethane. The thermoplastic polyester-based elastomer resin composition of claim 1, wherein the styrene-ethylene-butadiene-styrene copolymer does not contain mineral oil. A molded article comprising the thermoplastic polyester-based elastomer resin composition of any one of claims 1 to 5. The molded article according to claim 6, wherein the molded article is produced by injection molding. The molded article of claim 6 , wherein the molded article is a shoe sole.