KR20200128972A - Olefin-based thermoplastic resin composition - Google Patents

Abstract

The present invention relates to an olefin-based thermoplastic resin composition. More particularly, the present invention relates to an olefin-based thermoplastic resin composition, which can exhibit excellent processability, such as, in a vacuum molding process, by significantly improving tensile properties at equivalent hardness compared to a conventional olefin-based thermoplastic resin composition. The olefin-based thermoplastic resin composition includes ethylene-propylene copolymers, ethylene-propylene-diene copolymers, and linear low-density polyethylene.

Description

Olefin-based thermoplastic resin composition {OLEFIN-BASED THERMOPLASTIC RESIN COMPOSITION}

The present invention relates to an olefin-based thermoplastic resin composition, and more particularly, to an olefin-based thermoplastic resin composition, which can show excellent processability in a vacuum molding process, by significantly improving tensile properties at the same hardness compared to the conventional olefin-based thermoplastic resin composition. About.

In automobiles, various kinds of natural leather or synthetic resins are used for applications such as interior materials.

In recent years, as interest in the environment has increased, and when consumers purchase cars, the demand for not only basic specifications of automobiles such as driving performance and fuel economy, but also emotional aspects such as interior materials has increased. Is required.

In particular, automobile manufacturers, etc., are focusing on the development of automobile exteriors and interior materials that can create great added value with only a small cost, and are trying to satisfy consumers' emotions in various ways.

The skin of automobile interior materials such as door trim, instrument panel, headlining, and seat does not have a major environmental problem, can be recycled, and is lightweight. Thermoplastic olefin resins with excellent durability are widely used.

For example, in the case of door trim, injection-molded products using materials containing inorganic substances in polypropylene resin can be used, and the door trim body is made of a skin material with low hardness in order to improve the hard property and low-quality touch of plastic. It can be manufactured in a wrapping form.

As described above, in the process of wrapping the body of the interior material with a skin material with low hardness, productivity is high compared to the input cost, and can be used for a variety of materials, while making a product with equivalent quality compared to the product produced by the existing process. , Vacuum forming or continuous vacuum forming process is widely used.

However, in the case of the conventional olefin resin composition used for the skin material, the tensile properties are not good, so during the vacuum molding process as described above, the skin material bursts due to vacuum pressure, or the appearance quality of the manufactured product is deteriorated. There is a problem.

This specification is excellent in tensile properties, without causing a burst phenomenon in the vacuum forming or continuous vacuum forming process, door trim (door trim), instrument panel (instrument panel), ceiling (headlining), seat (seat), etc. , To provide an olefin-based thermoplastic resin composition having excellent appearance characteristics when used as a skin material for automobile interior materials.

According to an aspect of the present invention, an ethylene propylene copolymer, an ethylene propylene diene copolymer; And linear low density polyethylene; The storage modulus value measured according to ASTM E2254 at 150° C. is 800 to 1500 Pa, and the elasticity reduction temperature value is about 155° C. or higher; An olefinic thermoplastic resin composition is provided.

At this time, the storage modulus value may be preferably about 1000 to about 1400 Pa.

According to an embodiment of the present invention, the olefin-based thermoplastic resin composition may include a storage modulus change curve according to temperature of the olefin-based thermoplastic resin composition; The elasticity reduction temperature value defined as the contact point of i) a first tangent line in contact with the curve at 135° C. and ii) a second tangent line in contact with the curve at an inflection point may be about 155° C. or higher, and preferably about 155 To about 165°C, more preferably about 155 to about 157°C.

In addition, the olefin-based thermoplastic resin composition comprises about 10 to about 30 wt% of an ethylene propylene copolymer, ethylene propylene, based on the total weight of the base resin, including an ethylene propylene copolymer, an ethylene propylene diene copolymer, and a linear low density polyethylene. About 50 to about 80 wt% of the diene copolymer, and about 5 to about 20 wt% of the linear low density polyethylene.

According to another embodiment of the present invention, the ethylene propylene copolymer may include an ethylene propylene block copolymer having a melt index value of about 5 g/10 min or more at 230° C. 2.16 Kg measured according to ASTM D1238 standards. .

In addition, the ethylene propylene copolymer may further include an ethylene propylene random copolymer having a melt index value of about 5 g/10min or less at 230° C. 2.16 Kg measured according to ASTM D1238 standards.

In this case, the ethylene propylene copolymer, based on 100 parts by weight of the ethylene propylene block copolymer, may include about 10 to about 50 parts by weight of the ethylene propylene random copolymer, preferably about 30 to about 45 parts by weight. .

That is, the olefin-based thermoplastic resin composition according to an embodiment of the present invention may be a mixture including one or two different ethylene propylene copolymers.

In addition, the olefin-based thermoplastic resin composition may further contain a propylene homopolymer.

At this time, the propylene homopolymer, based on 100 parts by weight of the base resin, including ethylene propylene copolymer, ethylene propylene diene copolymer, and linear low density polyethylene; It may be included in about 5 to about 20 parts by weight, preferably about 5 to about 15 parts by weight.

In addition, the ethylene propylene diene terpolymer may include about 60 to about 80 wt% of ethylene, about 15 to about 35 wt% of propylene, and about 1 to about 7 wt% of diene.

According to another embodiment of the invention, the ethylene propylene diene copolymer, in addition to the general ethylene propylene diene terpolymer, may include an oil extended-ethylene propylene diene copolymer (Oil extended-Ethylene-Propylene-Diene copolymer). .

In this case, the oil-extended ethylene propylene diene copolymer may include about 40 to about 80 parts by weight of an extender oil based on 100 parts by weight of the ethylene propylene diene copolymer.

In addition to the above-described components, the olefin-based thermoplastic resin composition according to an embodiment of the present invention may further include any one or more additives of an inorganic filler, a crosslinking agent, a crosslinking aid, and a process oil.

And, such an olefin-based thermoplastic resin composition can be very suitably used in a vacuum molding process.

In the present invention, terms such as first and second are used to describe various components, and the terms are used only for the purpose of distinguishing one component from other components.

In addition, terms used in the present specification are only used to describe exemplary embodiments, and are not intended to limit the present invention.

Singular expressions include plural expressions unless the context clearly indicates otherwise.

In the present specification, terms such as "comprise", "include" or "have" are used to describe implemented features, numbers, steps, components, or combinations thereof, and one or more other features, numbers, and steps , Components, combinations or additions thereof are not excluded.

The present invention will be described in detail below and exemplify specific embodiments, as various changes can be made and various forms can be obtained. However, this is not to limit the present invention to a specific form disclosed, it should be understood to include all changes, equivalents, and substitutes included in the spirit and scope of the present invention.

Hereinafter, the present invention will be described in detail.

According to an aspect of the present invention, an olefin-based thermoplastic resin composition includes an ethylene propylene copolymer, an ethylene propylene diene copolymer; And linear low density polyethylene; The storage modulus value measured according to ASTM E2254 at 150° C. is 800 to 1500 Pa, and the elasticity reduction temperature value is about 155° C. or higher.

At this time, the storage modulus value may be preferably about 1000 to about 1400 Pa.

The storage modulus (G') value is a measure for evaluating the melt tension of a material. Using a DHR (Discovery Hybrid Rheometer), under conditions of a temperature of about 150°C, a strain of about 0.1%, and a frequency of about 1 Hz, the diameter It may be measured in a controlled-stress mode for a 30mm, 8mm thick circular specimen.

In the vacuum forming or continuous vacuum forming process, the resin to be processed or the resin composition processed in the form of a sheet or film is heated, placed on the top of the mold, and then decompressed through micropores existing on the surface of the mold. , The resin to be processed is brought into close contact with the mold, cooled, and then removed from the mold.

Vacuum molding or continuous vacuum molding has the advantage of high productivity compared to the input cost and applicable to various materials, but since the pressure is decompressed through micropores of the mold, the elasticity of the resin to be processed decreases during this process. However, a bursting phenomenon may occur without being able to overcome the pressure.

In the conventional case, in order to evaluate the suitability of vacuum forming or continuous vacuum forming of the resin to be processed, the resin to be processed is directly injected into the vacuum forming process, or injected into the roll-mill process, and the suitability of vacuum forming is inferred from the results. There was only a method.

However, the inventors of the present invention, ethylene propylene copolymer, ethylene propylene diene copolymer; And linear low-density polyethylene, in an olefin-based thermoplastic resin composition used as an automobile interior material, especially a skin material, when the storage modulus value at 150° C. is limited to a certain range, the tensile properties are excellent, and thus vacuum forming or No bursting phenomenon occurs in the continuous vacuum forming process, and when used as a skin material for automobile interior materials such as door trim, instrument panel, headlining, seat, etc. It was found that the properties were excellent, and the present invention was completed.

In particular, the olefin-based thermoplastic resin composition, in the storage modulus change curve according to the temperature of the olefin-based thermoplastic resin composition; The elasticity reduction temperature value, defined as the contact point of the first tangent line in contact with the curve at 135° C., and ii) the second tangent line in contact with the curve at the inflection point, may be about 155° C. or higher, preferably about It may be 155 to about 165 °C, more preferably about 155 to about 157 °C.

That is, according to an exemplary embodiment of the present invention, even if the resin to be processed is not directly injected into the vacuum forming process, only generally used physical properties may be measured to determine process suitability for vacuum forming or continuous vacuum forming.

In the olefin-based thermoplastic resin composition, as the temperature increases, the storage modulus value continuously decreases.At relatively low temperatures, the storage modulus value slowly decreases in a form similar to a linear function as the temperature increases, and then a specific When the temperature is reached, the value of the storage modulus rapidly decreases.

The temperature at which the storage modulus value rapidly decreases may be referred to as an elasticity decrease temperature value of the olefin-based thermoplastic resin composition. In particular, ethylene propylene copolymer, ethylene propylene diene copolymer; And in the case of the olefin-based thermoplastic resin composition of the present invention, which includes linear low-density polyethylene and is used as an automobile interior material, especially a skin material, the elasticity reduction temperature value may be defined by the following method.

First, for the olefin-based thermoplastic resin composition to be measured, the storage modulus according to the temperature is measured in a temperature range of about 100° C. to about 200° C., preferably about 130° C. to about 180° C., and the temperature (T, ℃) vs. storage modulus (G', Pa) curve.

In this curve, the first tangent line tangent to the curve is obtained at about 135° C., where the storage modulus decreases in a form similar to a linear function with increasing temperature.

Apart from this, in the curve, when the temperature corresponding to the inflection point of the storage modulus, that is, the storage modulus value is viewed as a function according to temperature change (G'=f(T)), the second derivative of the function (second order Differential function, d ² G'/dT ² ) Find the second tangent line on the curve at a temperature of 0.

The temperature obtained from the junction of the first tangent and the second tangent may be defined as an elasticity reduction temperature value (Onset Temperature).

1 is a conceptual diagram showing an elasticity reduction temperature value in a temperature vs. storage modulus curve of an olefin-based thermoplastic resin composition.

Referring to FIG. 1, a temperature (T, °C) vs storage modulus (G', Pa) curve (100) is obtained, and in this curve, the storage modulus decreases in a form similar to a linear function with increasing temperature, about The first tangent line 110 in contact with the curve at 135°C is obtained, and separately from this, in the curve, the temperature corresponding to the inflection point of the storage modulus, that is, the storage modulus value as a function according to the temperature change (G' =f(T)), after obtaining the second tangent line 120 in contact with the curve at a temperature at which the value of the ^second derivative (second derivative function, d ² G'/dT ² ) of the function becomes 0 , The temperature 132 (Onset Temperature), that is, the value of the elasticity reduction temperature 132, obtained from the contact point 131 of the first tangent and the second tangent may be checked.

That is, with the concept of Onset-Temperature, to analyze the storage elastic modulus value that is in a trend that continuously changes according to the temperature change, the concept of Onset-Temperature to analyze at which point the change starts to occur rapidly, the temperature can be analyzed. .

The olefin-based thermoplastic resin composition according to an embodiment of the present invention has an elasticity reduction temperature value defined as above of about 155°C or higher, preferably about 155 to about 165°C, more preferably about 155 to about 157 In the range of °C, it can exhibit excellent tensile properties in the temperature range of vacuum forming or continuous vacuum forming process. Accordingly, in the olefin-based thermoplastic resin composition according to an embodiment of the present invention, a burst phenomenon may not occur in a vacuum forming or continuous vacuum forming process in which pressure is decompressed through the micropores of the mold, and also the door trim of a vehicle When used as a skin material for automobile interior materials, such as (door trim), instrument panel, headlining, and seat, excellent appearance characteristics can be realized.

And, the olefin-based thermoplastic resin composition, based on the total weight of the base resin, including ethylene propylene copolymer, ethylene propylene diene copolymer, and linear low density polyethylene; 10 to 30 wt% of an ethylene propylene copolymer, 50 to 80 wt% of an ethylene propylene diene copolymer, and 5 to 20 wt% of a linear low density polyethylene.

Ethylene propylene copolymer is formulated to secure basic properties such as tensile strength and hardness of the final product and properties suitable for processing and molding.

The ethylene propylene copolymer, for example, may be an impact copolymer in which an ethylene-propylene copolymer is dispersed in a homopolypropylene matrix to form a mixed phase. In this case, the melt tension is greatly improved, so that the material adheres during processing, etc. Can be improved, and sheet sagging properties during vacuum molding can be improved.

The ethylene propylene copolymer is from about 10 to about 30 wt%, or about 15 to about 25 wt%, based on the total amount of the base resin, including ethylene propylene copolymer, ethylene propylene diene copolymer, and linear low density polyethylene. It may be included, and within this range, the melt tension of the composition may be improved to improve processability.

According to another embodiment of the present invention, the ethylene propylene copolymer has a melt index value of about 5 g/10 min or more, or about 5 to about 10 g/10 min at 230° C. 2.16 Kg as measured according to ASTM D1238 standards. Phosphorus, ethylene propylene block copolymer may be included.

Here, the ethylene propylene copolymer has a melt index value of about 5 g/10min or less, or about 0.1 to about 5 g/10min at 230° C. 2.16 Kg measured according to ASTM D1238 standards, ethylene propylene random copolymer It may further include.

That is, the olefin-based thermoplastic resin composition according to an embodiment of the present invention may be a mixture including one or two different ethylene propylene copolymers.

The above melt index values are ASTM D1238 According to the standard, it can be measured under a load of about 230° C. and about 2.16 Kg using a measuring device such as Dynisco's D4002HV.

By mixing and using an ethylene propylene copolymer having two kinds of different physical properties as described above, both mechanical strength and fluidity are excellent, and workability can be greatly improved in a vacuum forming process.

And when the olefin-based thermoplastic resin composition includes two different ethylene propylene copolymers, that is, includes both an ethylene propylene block copolymer and an ethylene propylene random copolymer, the olefin-based thermoplastic resin composition, the ethylene propylene Based on 100 parts by weight of the block copolymer, about 10 to about 50 parts by weight of the ethylene propylene random copolymer, or about 30 to about 45 parts by weight may be included.

The ethylene propylene copolymer may have a Rockwell hardness (ASTM D785-R scale) of about 70 to about 90 or about 70 to about 80, whereby the rigidity of the final product made of the olefin-based thermoplastic resin composition will be improved. I can.

In addition, the ethylene propylene copolymer may have a heat deformation temperature of about 100° C. to about 120° C. or about 105 to about 115° C., and thus, the melt strength of the olefin-based thermoplastic resin composition may be improved.

In the present specification, the heat distortion temperature of the ethylene propylene copolymer is a value measured under conditions of a load of 0.46 MPa according to ASTM D648 unless otherwise specified.

In addition, the olefin-based thermoplastic resin composition according to an embodiment of the present invention may further include a propylene homopolymer.

This propylene homopolymer may have a melt index value of about 10 g/10 min or more, preferably about 10 to about 15 g/10 min at 230° C. 2.16 Kg, as measured according to ASTM D1238 standards.

In this case, the propylene homopolymer is based on 100 parts by weight of the base resin, including ethylene propylene copolymer, ethylene propylene diene copolymer, and linear low density polyethylene; It may be included in about 5 to about 20 parts by weight, preferably about 10 to about 15 parts by weight.

The propylene homopolymer serves to crosslink together with the ethylene-propylene-diene copolymer, and can impart properties to the olefin-based resin composition to increase mechanical strength such as strength and hardness.

In the case of using another α-olefin propylene copolymer, ethylene propylene random copolymer, or homopolypropylene resin instead of the ethylene propylene copolymer used in the present invention, the calender processability and sheet sag improvement effect compared to the desired level in the present invention are improved. It may be insufficient, or mechanical properties such as tensile strength and elongation may be deteriorated.

That is, the olefin-based thermoplastic resin composition according to an embodiment of the present invention may be a composition in which no other α-olefin propylene copolymer is intentionally added, and preferably all of them are excluded.

The ethylene propylene diene copolymer is formulated to improve the melt tension and improve the basic properties such as strength and hardness of the final product.

The ethylene propylene diene copolymer comprises about 50 to about 80 wt%, or about 60 to about 80 wt% based on the total amount of the base resin, including ethylene propylene copolymer, ethylene propylene diene copolymer, and linear low density polyethylene. It can be included as a percentage.

The diene monomer contained in the ethylene propylene diene copolymer is one selected from butadiene, pentadiene, dicyclopentadiene, 1,4-hexadiene, methylene norbornene, ethylidene norbornene, cyclohexadiene, and derivatives thereof. It may be more than that, and it may be preferable that it is ethylidene norbornene in terms of crosslinking efficiency and improvement of physical properties.

And, the ethylene propylene diene terpolymer is about 60 to about 80 wt% ethylene, or about 65 to about 80 wt%, about 15 to about 35 wt% propylene, or about 15 to about 30 wt%, diene about 1 To about 7 wt%, or about 3 to about 7 wt%.

According to another embodiment of the invention, the ethylene propylene diene copolymer, in addition to the general ethylene propylene diene terpolymer, may include an oil extended-ethylene propylene diene copolymer (Oil extended-Ethylene-Propylene-Diene copolymer). .

These, oil-extended ethylene propylene diene copolymers, due to the oil component, can improve dispersibility in the composition, and do not cause the problem of seeping the oil component to the surface of the final product compared to the case of adding an oil component separately. , Processability can be improved.

In this case, the oil-extended ethylene propylene diene copolymer is about 40 to about 80 parts by weight, or about 45 to about 75 parts by weight, or about 45, based on 100 parts by weight of the ethylene propylene diene copolymer. To about 60 parts by weight.

The extender oil may specifically include, for example, paraffinic oil, naphthenic oil, and aromatic oil, and among them, paraffinic oil is preferred in terms of securing hardness and processability of the composition.

The ethylene propylene diene copolymer has a pattern viscosity value (ML ₁₊₄ , 125°C) of about 40 to about 80 MU, about 50 to about 80 MU, or about 50 to about 65 MU, measured according to ASTM D1646 standards. The oil-extended ethylene propylene diene copolymer may have a pattern viscosity value (ML ₁₊₈ , 125°C) of about 30 to about 70 MU, about 40 to about 60 MU, or about 45 to about 55 MU.

In addition, the linear low-density polyethylene is formulated to improve physical properties such as tensile strength, hardness, and heat resistance of the final product, and to secure thermal stability in the processing process.

The linear low-density polyethylene, for example, refers to a linear polyethylene having a density of about 0.920 to about 0.945 g/cm ³ , and has a relatively high content of short side chains, and is a general polyethylene or low density polyethylene in that it has almost no long side chains. And are distinct.

Such linear low-density polyethylene, based on the total amount of the base resin, including ethylene propylene copolymer, ethylene propylene diene copolymer, and linear low-density polyethylene, is about 5 to about 20 wt%, or about 5 to about 15 wt%, or about It may be included in a ratio of 5 to about 13 wt%.

In addition to the above-described components, the olefin-based thermoplastic resin composition according to an embodiment of the present invention may further include any one or more additives of an inorganic filler, a crosslinking agent, a crosslinking aid, and a process oil.

The inorganic filler is not particularly limited as long as it is a type commonly used in the technical field to which the present invention belongs, and preferably at least one selected from talc, mica, clay, kaolin, carbon black, barium sulfate, aluminum silicate, and calcium carbonate. have.

The inorganic filler may be included in an amount of about 0.1 to about 3 parts by weight, or about 0.5 to about 2 parts by weight, or about 0.5 to about 1.5 parts by weight, based on 100 parts by weight of the base resin.

The crosslinking agent may be a peroxide crosslinking agent or the like.

Specifically, an organic peroxide-based compound may be used, and may be included in an amount of about 0.05 to about 5 parts by weight, or about 0.1 to about 4 parts by weight, or about 1 to about 4 parts by weight, based on 100 parts by weight of the base resin described above. have.

The peroxide-based crosslinking agent, specifically, for example, benzoyl peroxide (benzoyl peroxide), lauryl peroxide (lauryl peroxide), dicumyl peroxide (dicumyl peroxide), 1,3-bis (t-butylperoxy Isopropyl)benzene (1,3-bis(t-butylperoxyisopropyl)benzene), di-t-butylperoxide, 2,5-dimethyl-2,5-di(t-butylperoxy) ) Hexane (2,5-dimethyl-2,5-di (t-butyl peroxy) hexane), 2,5-dimethyl-2,5-di (benzoyl peroxy) hexane (2,5-dimethyl-2,5 -di (benzoylperoxy hexane), P-chlorobenzol peroxide, n-butyl-4,4-bis (t-butylperoxy) valerate (n-butyl-4,4-bis (t -butylperoxy)ballylate), or 2,4-dichlorobenzoyl peroxide.

The crosslinking aid is formulated to prevent excessive decomposition of the resin component contained in the composition and stabilize radicals generated during high temperature processing.

Such crosslinking aids include, for example, bismaleimide compounds.

The bismaleimide-based compound can improve the crosslinking efficiency and crosslinking density of each component in the composition, thereby improving the melt tension of the composition.

Such a crosslinking aid may be used in an amount of about 0.01 to about 3 parts by weight, or about 0.01 to about 2 parts by weight, or about 0.05 to about 1.5 parts by weight, based on 100 parts by weight of the base resin described above.

Bismaleimide-based crosslinking aids are specifically, for example, (methylenedi-4,1-phenylene)bismaleimide [(Methylenedi-4,1-phenylene)bismaleimide], N,N'-1,3- Phenylene bismaleimide [N,N'-1,3-phenylene bismaleimide], N,N'-(4-methyl-1,3-phenylene) bismaleimide [N,N'-(4-methyl- 1,3-phenylene)bismaleimide], N,N'-hexamethylenebismaleimide [N,N'-Hexamethylene bismaleimide], N,N'-butylenebismaleimide [N,N'-1,4-butylene bismaleimide] and N,N'-(3,3'-dimethyl-4,4'-biphenylene)dimaleimide [N,N'-(3,3'-Dimethyl-4,4'-biphenylylene)dimaleimide ] May be one or more selected from, preferably (methylenedi-4,1-phenylene) bismaleimide.

The process oil may be the same type as the extension oil described in the ethylene propylene diene copolymer section, and specifically, for example, paraffinic oil, naphthalic oil, aromatic oil, and white oil.

In addition, the composition according to an embodiment of the present invention is optionally selected from antioxidants, UV stabilizers, heat stabilizers, lubricants, dyes, pigments, colorants, release agents, antistatic agents, antibacterial agents, processing aids, metal deactivators, etc. It may further include one or more additives.

These additives may be included in an amount of about 0.01 to about 5 parts by weight, based on about 100 parts by weight of the above-described base resin.

And, such an olefin-based thermoplastic resin composition can be very suitably used in a vacuum molding process.

On the other hand, such an olefin-based thermoplastic resin composition may be prepared by the following method.

First, an inorganic filler and a crosslinking aid are mixed with a base resin containing an ethylene propylene copolymer, an ethylene propylene diene copolymer, and a linear low density polyethylene, followed by melt kneading and extruding.

The melt kneading and extrusion is not particularly limited as long as it is equipment and conditions commonly used in the technical field to which the present invention pertains, and preferably, a half-bari kneader, a twin screw extruder, or a booth kneader may be used.

Each component constituting the composition may be added in a batch, and ethylene propylene copolymer, ethylene propylene diene copolymer, process oil, etc. are first added, followed by primary kneading and extrusion, followed by mixing with the remaining components and additives. It may be carried out in two or more steps of secondary kneading and extrusion.

The melt kneading and extrusion may be performed at, for example, about 150 to about 280°C or about 200 to about 250°C, but the present invention is not limited thereto.

The composition prepared through melt kneading and extrusion may be processed into a pellet shape through a pelletizer, or may be prepared into a sheet or the like through calendering.

The olefin-based thermoplastic resin composition according to an aspect of the present invention has excellent tensile properties at a high temperature, and does not cause a burst phenomenon in a vacuum molding or continuous vacuum molding process, and thus a door trim having excellent appearance, It is possible to provide a skin material for automobile interior materials, such as an instrument panel, a headlining, and a seat.

1 is a conceptual diagram showing an elasticity reduction temperature value in a temperature vs. storage modulus curve of an olefin-based thermoplastic resin composition.

Hereinafter, the functions and effects of the invention will be described in more detail through specific embodiments of the invention. However, these embodiments are only presented as examples of the invention, and the scope of the invention is not determined thereby.

The composition used to prepare the olefin-based thermoplastic resin composition is as follows.

1): A propylene homopolymer having a flow index (230° C., load 2.16 kg) of 12 g/10 min was used.

2): An ethylene-propylene random copolymer having a flow index (230° C., load 2.16 kg) of 4 g/10 min was used.

3): An ethylene-propylene block copolymer having a flow index (230° C., load 2.16 kg) of 8 g/10 min was used.

4) An ethylene-propylene random copolymer having a flow index (230° C., load 2.16 kg) of 0.3 g/10 min was used.

5) As an ethylene-propylene-diene copolymer component, ethylene-propylene- containing 73% by weight of ethylene, 5% by weight of ethylidene norbornene and the balance of propylene, and having a pattern viscosity ML ₁₊₄ of 60 MU (125°C) An ethylidene norbornene copolymer was used.

6) Oil-extended ethylene-propylene-diene copolymer component, containing 70% by weight of ethylene, 5.7% by weight of ethylidene norbornene, and the balance of propylene, and 50 parts by weight of paraffinic oil (based on 100 parts by weight of the copolymer). An expanded ethylene-propylene-ethylidene norbornene copolymer (ML ₁₊₈ , 125° C. = 49 MU) was used.

7) As the process oil, paraffin wax having a flash point of 300 to 580°C was used.

8) Linear low-density polyethylene with a flow index (230℃, load 2.16kg) of 8g/10min or less was used.

9) Talc was used as an inorganic filler.

10) As a crosslinking aid, methylenedi-4,1-phenylene bismaleimide, trimethylolpropane, triallyl cyanurate, and the like were used.

Examples and Comparative Examples

Each component was blended with the composition summarized in Table 1 below, and melt-kneaded and extruded at 200°C to prepare a specimen of a thermoplastic resin composition for measuring physical properties.

Unit: g Example 1 Example 2 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 One) - 9.14 9.14 9.14 2) - 5.75 5.27 5.75 5.75 3) 14.5 14.5 14.5 14.5 - - 4) - - - - 14.5 14.5 5) 22.27 30.27 22.27 30.27 30.27 30.27 6) 38.16 22.16 38.16 22.16 22.16 22.16 7) 10 3.3 2.3 3.3 3.3 3.3 8) 6 10 6 6 10 6 9) One One One One One One 10) About 0.2 About 0.2 About 0.2 About 0.2 About 0.2 About 0.2

Comparative Example 5

Milastomer, a TPV product from Mitsui, was obtained and used in the experiment.

<Experimental Example>

Storage modulus measurement

The storage modulus (G') of a circular specimen having a diameter of 30 mm and a thickness of 8 mm was measured in a temperature range of 110° C. to 180° C. using a DHR (Discovery Hybrid Rheometer) under a strain of 0.1% and a frequency condition of 1 Hz. Specifically, the specimen was heated from 110°C to 180°C at a rate of 5°C/min in the controlled-stress mode, and the storage modulus was measured at each temperature, and this was expressed as a temperature vs. storage modulus curve. From 150 ℃ storage modulus value and elasticity reduction temperature were derived.

Quality evaluation

In order to check whether it has suitable physical properties for calendering, the sheet was processed using a mini-roll mill at a temperature of 180 to 200°C, and the quality was evaluated with the naked eye. Based on whether or not the sheet was formed, when a sheet having a smooth surface and no wave pattern could be manufactured, it was evaluated that the tension property was excellent, and when damage such as tearing of the sheet during the roll mill process occurred, the tension property was evaluated to be inferior.

Elasticity reduction temperature
(℃) Storage modulus
(Pa) Quality evaluation Example 1 155.3 1178 Great Example 2 155.5 1376 Great Comparative Example 1 155.5 1625 Lowering Comparative Example 2 153.7 1075 Thirteen Comparative Example 3 153.5 1148 Thirteen Comparative Example 4 154.0 904 Thirteen Comparative Example 5 154.5 793 Thirteen

Referring to the above table, the olefin-based thermoplastic resin composition according to an embodiment of the present invention has a storage modulus value at 150° C. within a specific range, and an elastic reduction temperature value of about 155° C. or higher, It can show excellent tensile properties, and it can be seen that the quality related to the appearance during processing is very excellent.

However, as described above, when the storage elastic modulus value or the elasticity reduction temperature value does not satisfy the scope of the present invention, it can be clearly confirmed that the sheet is damaged during the processing process or other appearance-related quality is deteriorated. .

Accordingly, the olefin-based thermoplastic resin composition according to an embodiment of the present invention is expected to exhibit excellent processability in a molding process such as vacuum molding, and the door trim, instrument panel, and ceiling part (headlining) When used as a skin material for automobile interior materials, such as seats, it is expected to be able to provide products with excellent appearance characteristics.

100: temperature vs storage modulus curve
110: first tangent
120: second tangent
131: contact of the first tangent and the second tangent
132: elasticity reduction temperature

Claims (13)

Ethylene propylene copolymer, ethylene propylene diene copolymer, and linear low density polyethylene;
The storage modulus value measured according to ASTM E2254 at 150° C. is 800 to 1500 Pa;
The elasticity reduction temperature value is 155° C. or higher;
Olefin-based thermoplastic resin composition.
The method of claim 1,
The elasticity reduction temperature value is in the storage elastic modulus change curve according to the temperature of the olefin-based thermoplastic resin composition;
i) a first tangent line tangent to the curve at 135° C.,
ii) of a second tangent line tangent to the curve at the inflection point,
Defined as a contact point;
Olefin-based thermoplastic resin composition.
The method of claim 1,
Based on the total weight of the base resin, including ethylene propylene copolymer, ethylene propylene diene copolymer, and linear low density polyethylene
Including 10 to 30 wt% ethylene propylene copolymer, 50 to 80 wt% ethylene propylene diene copolymer, and 5 to 20 wt% linear low density polyethylene,
Olefin-based thermoplastic resin composition.
The method of claim 1,
The ethylene propylene copolymer includes an ethylene propylene block copolymer having a melt index value of 5 g/10 min or more at 230° C. 2.16 Kg measured according to ASTM D1238 standards,
Olefin-based thermoplastic resin composition.
The method of claim 4,
The ethylene propylene copolymer further comprises an ethylene propylene random copolymer having a melt index value of 5 g/10min or less at 230° C. 2.16 Kg measured according to ASTM D1238 standards,
Olefin-based thermoplastic resin composition.
The method of claim 5,
Containing 10 to 50 parts by weight of the ethylene propylene random copolymer, based on 100 parts by weight of the ethylene propylene block copolymer,
Olefin-based thermoplastic resin composition.
The method of claim 1,
An olefin-based thermoplastic resin composition further comprising a propylene homopolymer.
The method of claim 7,
The propylene homopolymer is;
Based on 100 parts by weight of the base resin, including ethylene propylene copolymer, ethylene propylene diene copolymer, and linear low density polyethylene;
Containing 5 to 20 parts by weight, olefin-based thermoplastic resin composition.
The method of claim 1,
The ethylene propylene diene copolymer comprises 60 to 80 wt% of ethylene, 15 to 35 wt% of propylene, and 1 to 7 wt% of diene,
Olefin-based thermoplastic resin composition.
The method of claim 1,
The ethylene propylene diene copolymer comprises an oil-extended ethylene propylene diene copolymer, an olefin-based thermoplastic resin composition.
The method of claim 10,
The oil-extended ethylene propylene diene copolymer comprises 40 to 80 parts by weight of an extender oil based on 100 parts by weight of the ethylene propylene diene copolymer, an olefin-based thermoplastic resin composition.
The method of claim 1,
Further comprising any one or more additives of inorganic fillers, crosslinking agents, crosslinking aids, and process oils,
Olefin-based thermoplastic resin composition.
The method of claim 1,
For vacuum molding, an olefin-based thermoplastic resin composition.

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