KR102265448B1 - Thermoplastic elastomer resin composition - Google Patents

Abstract

Provided are a thermoplastic elastomer resin composition comprising a thermoplastic elastomer resin and a compound containing at least one isocyanurate group as a reactive additive, and a molded article comprising the same.

Description

Thermoplastic elastomer resin composition

The present invention relates to a thermoplastic elastomer resin composition, and more particularly, to a thermoplastic elastomer resin composition in which the amount of outgas generated during injection molding is reduced.

Thermoplastic elastomer resins are used in various forms throughout industries such as electrical and electronic materials, biomaterials, and automobile materials based on excellent heat resistance, chemical resistance and durability, and are replacing existing materials. In particular, thermoplastic polyester-based elastomer resins are used in automobile parts, such as constant velocity joint boots, gearbox bellows, and air ducts. These automobile parts are manufactured by blow molding, and since the resin is produced through a blow process in a molten state, the resin in the molten state must have high melt viscosity and melt tension, and the parison shape must be maintained during extrusion blow. .

Reactive additives have been used to realize the properties of these blow molding materials. If the reactive additive is used, not only physical properties for blow molding can be realized, but also excellent heat resistance can be imparted to the molded product.

However, conventional reactive additives have a problem in that unreacted reactive additives may remain in the molded article during reaction extrusion. Residual reactive additives generate outgas during blow molding, and they gradually accumulate in the mold, causing mold deposition as the production process repeats. The materials deposited in the mold cause problems in workability, such as an injection defect and an increase in the number of mold cleaning times.

Therefore, there is a need to develop a thermoplastic elastomer resin composition for blow molding in which the mold deposition problem is improved due to less generation of outgas.

An object to be solved by the present invention is to provide a thermoplastic elastomer resin composition having improved injection molding workability due to a small amount of outgas generated.

In order to solve these problems, according to one aspect of the present invention, there is provided a thermoplastic elastomer resin composition of the following embodiments.

The first embodiment is

Based on 100 parts by weight of the composition,

A thermoplastic elastomer resin and a compound containing at least one isocyanurate group as a reactive additive in a weight ratio of 97.8:0.3 to 97.1:1.0,

It relates to a thermoplastic elastomer resin composition further comprising 0.05 to 1 part by weight of an antioxidant and 0.1 to 5 parts by weight of a surface modifier.

In the second implementation, in the first implementation,

The thermoplastic elastomer resin relates to a thermoplastic elastomer resin composition comprising a thermoplastic polyester elastomer (TPEE), a thermoplastic styrene-butadiene elastomer (TPE-S), a thermoplastic polyurethane (TPU), or two or more thereof.

A third embodiment, according to the first embodiment or the second embodiment,

The thermoplastic elastomer resin is a thermoplastic polyester-based elastomer (TPEE),

a hard segment in which the thermoplastic polyester-based elastomer includes polymerized units derived from an aromatic dicarboxyl compound and a diol; and a soft segment including polymerized units derived from polyalkylene oxide.

The fourth embodiment, according to the third embodiment,

The aromatic dicarboxyl compound comprises terephthalic acid, isophthalic acid, 1,5-dinaphthalene dicarboxylic acid, 2,6-dinaphthalene dicarboxylic acid, dimethyl terephthalate, dimethyl isophthalate, or a mixture of two or more thereof; ;

the diol includes ethylene glycol, propylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,4-cyclohexanedimethanol, or a mixture of two or more thereof;

The polyalkylene oxide relates to a thermoplastic elastomer resin composition comprising polyoxyethylene glycol, polyoxypropylene glycol, polyoxytetramethylene glycol, or a mixture of two or more thereof.

A fifth embodiment, according to the third or fourth embodiment,

The thermoplastic elastomer is branched by a branching agent, and the branching agent relates to a thermoplastic elastomer resin composition comprising glycerol, pentaerythritol, neopentyl glycol, or a mixture of two or more thereof.

A sixth embodiment, according to any one of the first to fifth embodiments,

The compound containing at least one isocyanurate group is hexamethylene diisocyanate-isocyanurate, isoprone diisocyanate-isocyanurate, toluene diisocyanate-isocyanurate, 4,4-cyclohexanebismethyl isocyanate It relates to a thermoplastic elastomer resin composition comprising -isocyanurate, 4,4'-dicyclohexylmethanediisocyanate-isocyanurate, methylenediphenyldiisocyanate-isocyanurate, or a mixture of two or more thereof.

A seventh embodiment, according to any one of the first to sixth embodiments,

It relates to a thermoplastic elastomer resin composition wherein the surface modifier is a silicone resin. The eighth embodiment further comprises an additive according to any one of the first to seventh embodiments, wherein the additive comprises a light stabilizer, a heat stabilizer, a lubricant, a reinforcing agent, a dye, a pigment, or a mixture of two or more thereof. It relates to a thermoplastic elastomer resin composition.

A ninth aspect relates to a molded article comprising the thermoplastic elastomer resin composition of any one of the first to eighth embodiments.

According to one embodiment of the present invention, there is provided a thermoplastic polyester-based elastomer resin composition with improved injection molding workability due to less outgassing, and a high-viscosity product suitable for blow molding using a vaporized ester-based elastomer. can produce In addition, it is possible to prevent mold deposition by reducing outgas, which is a problem in reactive extrusion, and to prevent injection defects caused by mold deposition, and thus can be expected to improve the workability of blow molding.

In addition, according to one embodiment of the present invention, while improving the mold deposition problem due to the reduction in outgassing, the mechanical properties are maintained at equal or higher than that of the prior art, so that blow-molded products such as constant velocity joint boots, gearbox bellows and air ducts can be used for manufacturing.

Hereinafter, the present invention will be described in detail. Prior to this, the terms or words used in the present specification and claims should not be construed as being limited to their ordinary or dictionary meanings, and the inventor should properly understand the concept of the term in order to best describe his invention. Based on the principle that it can be defined, it should be interpreted as meaning and concept consistent with the technical idea of the present invention.

Accordingly, the configurations shown in the embodiments described in the present specification are merely the most preferred embodiments of the present invention and do not represent all of the technical spirit of the present invention, so various equivalents that can be substituted for them at the time of the present application It should be understood that there may be variations and variations.

In addition, "part by weight" as used herein means a weight ratio between components included in the thermoplastic elastomer resin composition.

The thermoplastic elastomer resin composition according to an aspect of the present invention, based on 100 parts by weight of the composition, 95 to 99 parts by weight of the thermoplastic elastomer resin; and 0.2 to 2.5 parts by weight of a compound containing at least one isocyanurate group as a reactive additive.

The thermoplastic elastomer resin composition according to an embodiment of the present invention may include a thermoplastic elastomer (TPE) resin as a base resin.

As the thermoplastic elastomer resin, conventional thermoplastic elastomer resins may be used alone or in combination of two or more.

Examples of the thermoplastic elastomer resin include thermoplastic polyester elastomer (TPEE) (including thermoplastic copolyester elastomer), thermoplastic styrene-butadiene elastomer (TPE-S), thermoplastic polyurethane (TPU), or these It may contain a mixture of two or more of them.

According to one embodiment of the present invention, as the thermoplastic elastomer resin, a thermoplastic polyester-based elastomer (TPEE) may be used, and the thermoplastic polyester-based elastomer may be a conventionally used one, and the hardness is controlled by containing a plasticizer. However, the hardness of the thermoplastic polyester-based elastomer is not particularly limited and may be variously selected depending on the article to be applied.

The thermoplastic polyester-based elastomer is a thermoplastic polymer in which a hard hard segment and a soft soft segment are block copolymerized.

According to one embodiment of the present invention, the hard segment may include a polymerized unit derived from an aromatic dicarboxyl compound and a diol, and the soft segment may include a polymerized unit derived from a polyalkylene oxide.

Examples of the aromatic dicarboxyl compound include terephthalic acid (TPA), isophthalic acid (IPA), 1,5-dinaphthalenedicarboxylic acid (1,5-NDCA), Contains 2,6-Dinaphthalenedicarboxylic Acid (2,6-NDCA), Dimethyl Terephthalate (DMT), Dimethyl Isophthalate, or a mixture of two or more thereof It can be, specifically, dimethyl terephthalate can be used.

As the diol, a linear aliphatic diol having 2 to 8 carbon atoms or a cyclic aliphatic diol having 3 to 8 carbon atoms may be used, for example, ethylene glycol, propylene glycol, 1,4-butanediol, 1,5-pentanediol, 1, 6-hexanediol, 1,4-cyclohexanedimethanol, or a mixture of two or more thereof may be included. Specifically, 1,4-butanediol may be used.

The polyalkylene oxide may include polyoxyethylene glycol, polyoxypropylene glycol, polyoxytetramethylene glycol (PTMEG), or a mixture of two or more thereof, in detail may use polyoxytetramethylene glycol.

According to one embodiment of the present invention, the thermoplastic polyester-based elastomer may be branched by a branching agent, which increases the melt tension to increase the stability of the strand during the production of the polyester-based elastomer to improve and thereby increase productivity.

The branching agent may include, for example, glycerol, pentaerythritol, neopentylglycol, or a mixture of two or more thereof, and specifically glycerol may be used.

The thermoplastic polyester-based elastomer according to an embodiment of the present invention may be generally prepared through melt polymerization consisting of two steps of an oligomerization reaction and a polycondensation reaction, and preferably a branched thermoplastic polyester-based elastomer. have.

In one embodiment of the present invention, the branched thermoplastic polyester-based elastomer is prepared by adding the above-mentioned components to the reactor, and thereafter, a suitable catalyst (eg, tetra-n-butoxy titanium (TBT)). ), can be prepared through melt polymerization consisting of two steps of oligomerization and polycondensation reaction.The oligomerization reaction can be carried out at 140 to 215 ° C. for 3 to 4 hours, and the polycondensation reaction is It may proceed as a process of stepwise decompression from 760 torr to 0.3 torr at 210 to 250° C. for 4 to 5 hours.

In one embodiment of the present invention, in consideration of mechanical strength and flexibility, etc., the soft segment content in the thermoplastic polyester elastomer is 5 to 75 wt%, specifically 30 wt% based on 100 wt% of the total thermoplastic polyester elastomer to 70% by weight. When the content of the soft segment in the polyester-based elastomer satisfies this range, the hardness of the thermoplastic polyester-based elastomer is not excessively high, flexibility is improved, and high heat resistance performance can be realized.

According to one embodiment of the present invention, the polyester-based elastomer may have an intrinsic viscosity of 1.7 to 2.2 dl/g, specifically 1.9 to 2.0 dl/g.

The thermoplastic elastomer resin composition of the present invention includes a compound containing at least one isocyanurate group as a reactive additive in order to enable blow molding by increasing melt viscosity and melt tension.

Specifically, the isocyanurate group is made by combining three isocyanate compounds, and has excellent thermal stability. Compared to the conventional isocyanate compound having two or less reactive groups, the isocyanurate group has more reactive groups, so it can form more chains and urethane bonds of the thermoplastic elastomer resin, resulting in better properties in terms of molecular weight increase and may play a role in improving thermal stability. As a result, by using a compound containing at least one isocyanurate group as a reactive additive, it is possible to improve mechanical properties and lower viscosity to enable blow molding.

In addition, since the isocyanurate group contained in the reactive additive of the present invention has one more isocyanate group compared to the conventional isocyanate compound, it is less likely to react with the thermoplastic elastomer resin to release unreacted substances, and isocyanurate Since the compound having a rate group has excellent thermal stability by itself, it can be decomposed during injection to reduce the possibility of gas coming out and depositing in the mold.

The compound usable as the reactive additive may be used without limitation as long as it contains at least one isocyanurate group. For example, a compound containing one or more isocyanurate groups is hexamethylenediisocyanate-isocyanurate, isoprondiisocyanate-isocyanurate, toluenediisocyanate-isocyanurate, 4,4-cyclohexane Bismethylisocyanate-isocyanurate, 4,4'-dicyclohexylmethanediisocyanate-isocyanurate, methylenediphenyldiisocyanate-isocyanurate, or a mixture of two or more thereof, but is limited thereto doesn't happen

The thermoplastic elastomer resin composition of the present invention includes 95 to 99 parts by weight of the thermoplastic elastomer resin, and 0.2 to 2.5 parts by weight of the reactive additive, based on 100 parts by weight of the composition.

In one embodiment of the present invention, the content of the reactive additive may be 0.3 to 2 parts by weight, more specifically 0.5 to 1 parts by weight, based on 100 parts by weight of the composition. If the content of the reactive additive is less than 0.2 parts by weight based on 100 parts by weight of the composition, the melt viscosity is low and it is difficult to use it as a blow molding material. Workability may be poor.

The thermoplastic elastomer resin composition of the present invention may further include an antioxidant in order to prevent the thermoplastic elastomer resin from being deteriorated and oxidized during the high-temperature injection molding process.

The type of the antioxidant is not particularly limited, and antioxidants commonly used in this field may be used without limitation. For example, hindered amine antioxidant, hindered phenol antioxidant, phosphite antioxidant, amide antioxidant, thioester antioxidant An antioxidant or a mixture of two or more thereof may be used as the antioxidant, but is not limited thereto.

More specifically, 4,4'-bis(α,α-diphenylbenzyl)diphenyl amine, octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)-propionate, Or a mixture of two or more of them may be used as the antioxidant, but is not limited thereto.

The content of the antioxidant may be 0.05 to 1 part by weight, specifically 0.1 to 0.5 parts by weight, based on 100 parts by weight of the composition.

The thermoplastic elastomer resin composition of the present invention may further include one or more additives commonly used in the thermoplastic elastomer resin composition in addition to the above components. The additive may be, for example, a light stabilizer, a heat stabilizer, a surface modifier, a lubricant, a reinforcing agent, a dye, a pigment, or a mixture of two or more thereof, but is not limited thereto. Among them, examples of the surface modifier include, but are not limited to, a silicone resin. The surface modifier is compounded with a thermoplastic elastomer resin and migrated to the surface of the injection product when it is injected, and serves to protect the surface, and at the same time has an effect that it is more easily removed from the injection mold, thereby improving moldability.

The content of the additive is not particularly limited and may be used without limitation in a range that does not impair the physical properties desired by the present invention. For example, the content of the additive may be 0.1 to 5 parts by weight, specifically 0.5 to 3 parts by weight, based on 100 parts by weight of the composition, but is not limited thereto.

The thermoplastic elastomer resin composition according to an embodiment of the present invention may be prepared by adding the above-described thermoplastic elastomer resin, reactive additive, optionally antioxidant, and optional additives to an extruder, mixing in the extruder, and extruding.

A twin-screw or single-screw extruder may be used as the extruder, and the extruder L/D (length/diameter) may be 20 to 35, but is not limited thereto.

As the extrusion conditions, an extruder temperature of 180 to 220° C. and RPM 150 to 350 may be used, but is not limited thereto.

The thermoplastic elastomer resin composition of the present invention prepared as described above has high melt viscosity and melt tension, and thus can be utilized as a blow molding material.

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

The molded article provided according to an embodiment of the present invention may be a constant velocity joint boot of a vehicle, a gearbox bellows or an air duct.

Hereinafter, to help the understanding of the present invention, examples will be described in detail. However, the embodiments according to the present invention may be modified in various other forms, and the scope of the present invention should not be construed as being limited to the following examples. The embodiments of the present invention are provided to more completely explain the present invention to those of ordinary skill in the art.

[Example]

<Production of thermoplastic polyester-based elastomer resin>

Preparation Example 1: Preparation of TPEE of Shore Hardness D-40

34.60 parts by weight of dimethyl terephthalate (DMT), 25.0 parts by weight of 1,4-butanediol, 40.20 parts by weight of polyoxytetramethylene glycol (PTMEG) having a molecular weight of 2,000, and 0.065 parts by weight of glycerol were placed in an oligomerization reactor and tetra-n-part as a catalyst 0.025 parts by weight of toxy titanium (TBT) was added. The reaction temperature was raised from 140°C to 215°C for 120 minutes, and reacted for the remaining 120 minutes while maintaining 215°C. The reaction was terminated when the reaction rate was 99% or more by converting the amount of methanol as the reaction effluent into the reaction rate. Thereafter, 0.04 parts by weight of TBT as a catalyst and 0.07 parts by weight of a thermal stabilizer (Irganox 1010) were added to perform a polycondensation reaction. The polycondensation reaction was performed by raising the temperature from 215°C to 250°C for 120 minutes, and reacting for the remaining 120 minutes while maintaining 250°C. At this time, the pressure was reduced from 760 torr to 0.3 torr for 1 hour, and for the remaining 3 hours, the vacuum condition was 0.3 torr or less, but the final reduced pressure was adjusted to 0.3 torr or less to prepare TPEE of Shore Hardness-D 40. The intrinsic viscosity of the thus-made TPEE was 1.7 dl/g as measured in a solvent of phenol/tetrachloroethane = 50/50.

<Preparation of thermoplastic elastomer resin composition>

Examples 1 to 4 and Comparative Examples 1 to 5

Resin compositions of Examples and Comparative Examples were prepared with the compositions shown in Table 1 below. The raw materials made of the TPEE resin and additives prepared in Preparation Example 1 were simultaneously introduced into a twin-screw extruder and extruded. The temperature of the extruder was extruded by setting the hopper part to 150 ° C and the remaining parts to 190 ° C to 230 ° C. A twin screw (L/D = 40) was used, the diameter of the die was 26 phi, and a kneading block (Kneading block) was used. 2 blocks) were used. The feed rate of the resin was 10 kg/hr to 12 kg/h, and the rotation speed of the extruder screw was 150 rpm to 200 rpm for extrusion.

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

<Ingredient Description>

TPEE: Thermoplastic polyester-based elastomer prepared in Preparation Example 1

Reactive additive: hexamethylene diisocyanate (HDI) isocyanurate (trimer) (TLA-100, manufactured by Asahikasei Co., Ltd.)

Naphthalene diisocyanate: HATDUR 115 (Johnson fine chemical (manufactured))

Silicone resin: MB50-010 (Dow Corning Co.)

Heat-resistant stabilizer: NAUGAURD 445 (Chemtura (Product))

Antioxidant 1: Sulfur-based antioxidant (Irganox 412S, BASF)

Antioxidant 2: Phenolic antioxidant (SONG 1076, Songwon Industrial Co., Ltd.)

The following items were measured for the thermoplastic elastomer resin composition prepared as described above to confirm the physical properties, and the results are shown in Table 2 below.

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

(2) Tensile elongation: Evaluated according to ASTM D638.

(3) Modulus: evaluated according to ASTM D638.

(4) Melt index: It was measured after staying for 3 minutes at a temperature of 230°C and a load of 10.0 kg according to ASTM D1238.

(5) Outgas: Through GC/MS analysis, gases generated when a sample of the same weight was analyzed by GC/MS at 230°C were checked, and the total area of outgas (total amount of outgas) was calculated and measured.

(6) Mold deposition: When 50 square specimens with a size of 8 cm × 6 cm × 6.5 mm were continuously injected, the presence or absence of white deposits deposited on the gas vent part of the mold was judged.

As shown in Table 2, in the case of Examples 1 to 4 according to the present invention, mechanical properties such as tensile strength, tensile elongation and modulus are excellent, and melt viscosity is high (low melt index), so it is suitable as a material for blow molding In particular, it was confirmed that there was no mold deposition by significantly reducing the generation of outgas, which was a problem in the prior art.

However, in the case of Comparative Example 1 in which the content of the isocyanurate group-containing compound was small, the viscosity was too low (high melt index), and thus it was not suitable as a material for blow molding, and the content of the isocyanurate group-containing compound was excessive. In the case of Example 2, mold deposition occurred due to the high generation of outgas, and in Comparative Examples 3 to 5 using a conventional isocyanate-based compound rather than an isocyanurate group-containing compound as a reactive additive, outgassing even when an appropriate amount was used It was confirmed that mold deposition occurred due to the large number of occurrences.

Claims (9)

Based on 100 parts by weight of the composition,
A thermoplastic elastomer resin and a compound containing at least one isocyanurate group as a reactive additive in a weight ratio of 97.8:0.3 to 97.1:1.0,
A thermoplastic elastomer resin composition further comprising 0.05 to 1 parts by weight of an antioxidant and 0.1 to 5 parts by weight of a surface modifier. According to claim 1,
The thermoplastic elastomer resin comprises a thermoplastic polyester-based elastomer (TPEE), a thermoplastic styrene-butadiene-based elastomer (TPE-S), a thermoplastic polyurethane (TPU), or two or more of them. According to claim 1,
The thermoplastic elastomer resin is a thermoplastic polyester-based elastomer (TPEE),
a hard segment in which the thermoplastic polyester-based elastomer includes polymerized units derived from an aromatic dicarboxyl compound and a diol; and a soft segment including polymerized units derived from polyalkylene oxide. 4. The method of claim 3,
The aromatic dicarboxyl compound comprises terephthalic acid, isophthalic acid, 1,5-dinaphthalene dicarboxylic acid, 2,6-dinaphthalene dicarboxylic acid, dimethyl terephthalate, dimethyl isophthalate, or a mixture of two or more thereof; ;
the diol includes ethylene glycol, propylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,4-cyclohexanedimethanol, or a mixture of two or more thereof;
The thermoplastic elastomer resin composition wherein the polyalkylene oxide comprises polyoxyethylene glycol, polyoxypropylene glycol, polyoxytetramethylene glycol, or a mixture of two or more thereof. 4. The method of claim 3,
The thermoplastic elastomer resin composition in which the thermoplastic polyester-based elastomer is branched by a branching agent, and the branching agent includes glycerol, pentaerythritol, neopentyl glycol, or a mixture of two or more thereof. According to claim 1,
The compound containing at least one isocyanurate group is hexamethylene diisocyanate-isocyanurate, isoprone diisocyanate-isocyanurate, toluene diisocyanate-isocyanurate, 4,4-cyclohexanebismethyl isocyanate -Isocyanurate, 4,4'-dicyclohexylmethanediisocyanate-isocyanurate, methylenediphenyldiisocyanate-isocyanurate, or a thermoplastic elastomer resin composition comprising a mixture of two or more thereof. According to claim 1,
The thermoplastic elastomer resin composition wherein the surface modifier is a silicone resin. According to claim 1,
A thermoplastic elastomer resin composition further comprising an additive comprising a light stabilizer, a heat stabilizer, a lubricant, a reinforcing agent, a dye, a pigment, or a mixture of two or more thereof. A molded article comprising the thermoplastic elastomer resin composition of any one of claims 1 to 8.