KR102088901B1 - Thermoplastic resin composition and molded article comprising the same - Google Patents

Abstract

The present invention relates to a thermoplastic resin composition and a molded article comprising the same, more specifically 30 to 47% polypropylene block copolymer with a crystallinity of 30 to 60% by weight, and a polypropylene block copolymer with a crystallinity of 48 to 60% of 10 to 10% A thermoplastic resin composition comprising a 40% by weight, 10 to 40% by weight of a polyolefin elastomer, 1 to 15% by weight of a filler, and 0.1 to 5% by weight of a polypropylene-acrylic compound graft copolymer, and a molded article comprising the same will be.
According to the present invention, it is lighter than metal, has excellent workability, and has a high degree of freedom in design, while providing the same level of collision safety performance as a crash box of a conventional metal material, while realizing the same buckling and breaking form. It has the effect of providing a thermoplastic resin composition and a molded article comprising the same.

Description

Thermoplastic resin composition and molded article comprising the same {THERMOPLASTIC RESIN COMPOSITION AND MOLDED ARTICLE COMPRISING THE SAME}

The present invention relates to a thermoplastic resin composition and a molded article containing the same, and more specifically, it is lighter than metal, has excellent processability, has a high degree of freedom in design, and has the same level of collision as a crash box of an existing metal material. The present invention relates to a thermoplastic resin composition that realizes the same buckling and fracture shape and a molded article including the same while providing safety performance.

Recently, polymer materials are used in a wide variety of fields closely related to real life such as automobiles, home appliances, IT products, and construction subsidiary materials. In particular, in the automotive related field, it is possible to be lighter than metal, has excellent workability, has a high degree of freedom in product design, and can reduce cost, and its application is gradually expanding.

In this regard, in the case of a back beam located in the interior of a vehicle bumper corresponding to a primary safety part in the event of a collision of a vehicle, glass fiber reinforced thermoplastics or metal materials are generally used. have. However, this has a problem that it cannot satisfy both safety and light weight, which are the major issues in the recent automotive market. In the case of glass fiber-reinforced thermoplastic resins, collision energy cannot be efficiently absorbed due to bursting and tearing of the resin after collision, and thus collision safety is deteriorated, and viewers can instill distrust and anxiety about safety. In this case, the weight is heavier than that of the polymer material, causing a decrease in vehicle output. Accordingly, there is a continuous demand for the development of polymer materials with light weight and collision safety performance.

KR 0353066 B1

In order to overcome the problems of the prior art, the present invention provides a collision safety performance equivalent to that of a conventional metal box crash box, while being lighter than metal, having excellent processability, and having a high degree of freedom in design. , It is an object to provide a thermoplastic resin composition embodying the same buckling and breaking form.

In addition, an object of the present invention is to provide a molded article comprising the thermoplastic resin composition.

The above and other objects of the present invention can be achieved by the present invention described below.

In order to achieve the above object, the present invention is 30 to 60% by weight of a polypropylene block copolymer having a crystallinity of 30 to 47%, 10 to 40% by weight of a polypropylene block copolymer having a crystallinity of 48 to 60%, and 10 to 10 of a polyolefin elastomer. Provided is a thermoplastic resin composition comprising 40% by weight, 1 to 15% by weight of a filler, and 0.1 to 5% by weight of a polypropylene-acrylic compound graft copolymer.

In addition, the present invention provides a molded article comprising the thermoplastic resin composition.

According to the present invention, it is lighter than metal, has excellent processability, and has a high degree of freedom in design, while providing the same level of crash safety performance as a crash box of a conventional metal material, while realizing the same buckling and breaking form. It has the effect of providing a thermoplastic resin composition and a molded article comprising the same.

Hereinafter, the present invention will be described in detail.

The present inventors use a mixture of a high crystalline polypropylene block copolymer with a general polypropylene block copolymer when manufacturing the thermoplastic resin composition, and include a specific filler and additives, thereby improving the bonding strength in the resin composition, buckling during collision And it was confirmed that the fracture shape is implemented in the same form as the metal material, thereby completing the present invention.

The thermoplastic resin composition according to the present invention is 30 to 60% by weight of a polypropylene block copolymer having a crystallinity of 30 to 47%, 10 to 40% by weight of a polypropylene block copolymer having a crystallinity of 48 to 60%, and 10 to 40% by weight of a polyolefin elastomer %, 1 to 15% by weight of the filler, and 0.1 to 5% by weight of the polypropylene-acrylic compound graft copolymer.

Looking at the thermoplastic resin composition in detail as follows.

A. Polypropylene block copolymer with crystallinity of 30 to 47%

The polypropylene block copolymer having a crystallinity of 30 to 47% may be, for example, an ethylene-propylene block copolymer, and in this case, there is an effect of excellent collision safety performance and processability.

The polypropylene block copolymer having a crystallinity of 30 to 47% may have, for example, an ethylene content of 1 to 30% by weight, 5 to 25% by weight, or 5 to 15% by weight, and collision safety performance and processability within this range. This has an excellent effect.

The polypropylene block copolymer having a crystallinity of 30 to 47% has, for example, a melt index (230 ° C., 2.16 kg) of 30 to 60 g / 10 min, 40 to 60 g / 10 min, or 45 to 55 g / 10 min. It may be and has an excellent effect of dispersibility within this range.

The polypropylene block copolymer having a crystallinity of 30 to 47% may be, for example, a crystallinity of 30 to 47%, 33 to 46%, or 35 to 45%, and has excellent impact safety performance and processability within this range. There is.

The polypropylene block copolymer having a crystallinity of 35 to 45% may be included in an amount of 30 to 60% by weight, 35 to 55% by weight, or 40 to 50% by weight relative to the thermoplastic resin composition, for example, processability within this range. This has an excellent effect.

B. Polypropylene block copolymer with a crystallinity of 48 to 60%

The polypropylene block copolymer having a crystallinity of 48 to 60% may be, for example, an ethylene-propylene block copolymer, and in this case, there is an effect of excellent collision safety performance and processability.

The polypropylene block copolymer having a crystallinity of 48 to 60% may have, for example, an ethylene content of 1 to 25% by weight, 1 to 15% by weight, or 5 to 10% by weight, and collision safety performance and processability within this range. This has an excellent effect.

The polypropylene block copolymer having a crystallinity of 48 to 60% has, for example, a melt index (230 ° C., 2.16 kg) of 70 to 130 g / 10 min, 75 to 120 g / 10 min, or 85 to 110 g / 10 min. It may be, due to the high flowability within this range, when the insert (insert) injection of the continuous fiber composite material (CFT) minimizes the push of the continuous fiber composite material, there is an excellent moldability effect.

The polypropylene block copolymer having a crystallinity of 48 to 60% has an excellent collision safety performance and processability within the crystallinity range.

The polypropylene block copolymer having a crystallinity of 48 to 60% may be included, for example, 10 to 40% by weight, 10 to 30% by weight, or 13 to 23% by weight relative to the thermoplastic resin composition, and processability within this range This has an excellent effect.

The crystallinity of 30 to 47% polypropylene block copolymer and the polypropylene block copolymer having a crystallinity of 48 to 60% are, for example, 1: 1 to 5: 1, 1.5: 1 to 4: 1, or 1.5: 1 to 3 It can be included in a weight ratio of 1: 1, and within this range, there is an excellent effect of workability, collision safety performance and physical property balance.

C. Polyolefin elastomer

The polyolefin elastomer is for improving processability and physical property balance in the thermoplastic resin composition, and may be, for example, a copolymer of ethylene and α-olefin. The α-olefin may be one or more selected from the group consisting of 1-butene, 1-pentene, 1-hexene and 1-octene.

The polyolefin elastomer may be, for example, ethylene-octene elastomer, ethylene-butene elastomer or a mixture thereof.

The polyolefin elastomer may be, for example, ethylene or α-olefin branched to a backbone polymerized with the ethylene and α-olefin, and ethylene or α-olefin branched to the main chain is For example, it may be 20 to 50% by weight, 25 to 45% by weight, or 30 to 40% by weight with respect to the polyolefin elastomer, and within this range, there is an excellent effect of balance of processability and physical properties.

The polyolefin elastomer may have, for example, a density of 0.8 to 0.9 g / cm ³ , 0.85 to 0.88 g / cm ³ , or 0.865 to 0.870 g / cm ³ , and has an excellent collision safety performance within this range.

The polyolefin elastomer may have, for example, a melt index (190 ° C., 2.16 kg) of 0.1 to 10 g / 10 min, 0.5 to 6.5 g / 10 min, 0.5 to 1.5 g / 10 min, or 3.5 to 6.5 g / 10 min. There is an effect of excellent workability and physical property balance within this range.

The polyolefin elastomer may be included in an amount of 10 to 40% by weight, 15 to 40% by weight, or 20 to 35% by weight with respect to the thermoplastic resin composition, and has excellent processability and collision safety performance within this range.

D. Filler

The filler is not particularly limited when it is a commonly used filler, and may be, for example, a mineral filler, and in this case, has an excellent collision safety performance.

The mineral filler may be one or more selected from the group consisting of calcium carbonate, talc, mica and silica.

The mineral filler may include, for example, a hydroxy group (-OH), in which case hydrogen is dissociated from the hydroxy group (-OH), and the polypropylene-acrylic compound graft copolymer is hydrogen-bonded (hydrogen bond). It is excellent in bonding strength by forming, and accordingly, it has an effect of minimizing the bursting phenomenon of the resin composition in case of collision.

The filler may be included, for example, 1 to 15% by weight, 5 to 15% by weight, or 7 to 13% by weight relative to the thermoplastic resin composition, and there is an excellent effect of collision safety performance and physical property balance within this range.

E. Polypropylene-acrylic compound graft copolymer

The polypropylene-acrylic compound graft copolymer is a graft copolymer in which an acrylic compound is graft polymerized with polypropylene as a backbone, and by giving a polar group to polypropylene, the acrylic compound has a surface of the filler. By forming a hydrogen bond (hydrogen bond) and excellent bonding force, there is an effect of minimizing the burst phenomenon of the resin composition accordingly.

The acrylic compound of the polypropylene-acrylic compound graft copolymer may be, for example, a (meth) acrylic acid alkyl ester compound, specific examples include (meth) acrylic acid methyl ester, (meth) acrylic acid ethyl ester, (meth) acrylic acid propyl ester, It may be at least one selected from the group consisting of (meth) acrylic acid 2-ethylhexyl ester, (meth) acrylic acid decyl ester, and (meth) acrylic acid lauryl ester, and in this case, there is an excellent collision safety performance.

The acrylic compound may be copolymerized with, for example, ethene, 1-butene, 1-pentene, 1-hexene and 1-octene when graft polymerization is performed on the polypropylene, and in another example, ethylene.

The polypropylene-acrylic compound graft copolymer may have, for example, a density at 25 ° C of 0.85 to 0.99 g / cm ³ , 0.88 to 0.97 g / cm ³ , or 0.9 to 0.94 g / cm ³ .

The polypropylene-acrylic compound graft copolymer may be included in an amount of 0.1 to 5% by weight, 1 to 5% by weight, and 1.5 to 3% by weight with respect to the thermoplastic resin composition, and within this range, the surface of the filler and The area of formation of a hydrogen bond is maximized, and thus the bonding force is excellent, and the collision safety performance is excellent.

F. Thermoplastic resin composition

The thermoplastic resin composition may further include, for example, a nucleating agent for inducing crystal growth of the polypropylene block copolymer. In this case, when the crystals of the polypropylene block copolymer are produced, there is an effect of inducing the production of crystals in the form of beta-crystals (β-modification) rather than in the form of alpha-crystals. When the beta-crystal (β-modification) crystal generation is generated as described above, when a collision occurs, the beta-crystal (β-modification) crystal is primarily converted into an alpha-crystal (α-modification) crystal. As a result, the collision energy is absorbed and the polypropylene block copolymer having an alpha-crystal (α-modification) crystal phase collides with the alpha-crystal (α-modification) crystal. It has an excellent performance effect.

The nucleating agent may be, for example, one or more selected from the group consisting of calcium hydroxide and wollastonite, and as another example, a masterbatch may be formed with polypropylene, and in this case, the nucleating agent is evenly dispersed in the resin composition.

The nucleating agent may be included, for example, 0 to 5% by weight, 0.1 to 3% by weight, or 0.5 to 2% by weight with respect to the thermoplastic resin composition, and has excellent effect in collision safety performance and physical property balance within this range.

The thermoplastic resin composition is composed of a lubricant, an antioxidant, a chain extender, a catalyst, a release agent, a pigment, a dye, an antistatic agent, an antibacterial agent, a processing aid, a metal inactivating agent, a smoke retardant, an anti-friction agent, an abrasion resistance and a coupling agent, if necessary. It may further include one or more additives selected from the group. The additive may be used within a range that does not adversely affect the physical properties of the thermoplastic resin composition of the present invention.

The thermoplastic resin composition may be in the form of beta-crystal (β-modification), for example, and another example may be a ductile fracture in the form of fracture due to collision.

The thermoplastic resin composition may have, for example, a surface impact energy of -30 ° C of 23 J or more, 23 to 40 J, or 24 to 32 J.

G. Molded products

The molded article according to the present invention is characterized by including the thermoplastic resin composition.

The molded article may include, for example, continuous fiber thermoplastic (CFT), and as a specific example, the thermoplastic resin composition and the insert of the continuous fiber composite may be an injection molded article.

The continuous fiber composite material may include, for example, polypropylene and glass fiber, and the glass fiber may be, for example, continuous phase glass fiber.

The molded article may be, for example, a molded article for an automobile back beam.

Hereinafter, preferred embodiments are provided to help the understanding of the present invention, but the following examples are merely illustrative of the present invention, and it is apparent to a person skilled in the art that various changes and modifications are possible within the scope and technical scope of the present invention. It is natural that such variations and modifications fall within the scope of the appended claims.

[Example]

Examples 1 to 3 and Comparative Examples 1 to 4

The ingredients shown in Table 1 below were mixed using a mixer at the stated content (% by weight), and melted and kneaded in a temperature range of 190 to 260 ° C using a twin-screw extruder to prepare pellets. 2.1 to 2.3 kg of the resin composition of the prepared pellet form and 0.7 to 1.1 kg of the continuous fiber composite material were insert-injected using an insert injection machine to prepare specimens for measuring physical properties.

division Example Comparative example One 2 3 One 2 3 4 PP-1 46.5 45 45 48 13 - 65 PP-2 16 16 15 16 40 65 - POE 26 26 26 26 24 20 20 MF 10 10 10 10 20 15 15 AD 1.5 3 3 - 3 - - NA - - One - - - -

* PP (polypropylene) -1: 30-47% polypropylene block copolymer with crystallinity (manufactured by Polymira, product name Moplen 542T)

* PP (polypropylene) -2: polypropylene block copolymer having a crystallinity of 48 to 60% (manufactured by Daehan Petrochemical, product name YUHWA POLYPRO CB5290)

* POE (Polyolefin Elastomer): Ethylene-octene elastomer with branched octene content of 35% by weight

* MF (mineral filler): talc (manufactured by Koch, product name KCM6300)

* AD (additive): A graft copolymer obtained by graft polymerization of acrylic acid ethyl ester on polypropylene

* NA (nucleating agent): calcium hydroxide (polypropylene masterbatch)

[Test Example]

The physical properties of the specimens obtained in Examples 1 to 3 and Comparative Examples 1 to 4 were measured by the following method, and the results are shown in Table 2 below.

How to measure

* Melt Index: Measured according to standard measurement ASTM D1238 (230 ℃, 2.16 kg condition) using a specimen.

* Crystallinity: Measured using Gel Permeation Chromatography (GPC).

* Planar impact energy (J): Using the specimen, standard impact ASTM D3763 was used to measure plane impact energy at room temperature (23 ° C) and low temperature (-30 ° C).

* Buckling type: Using a specimen, after colliding according to a 40% off set test in the RCAR test, the buckling type is visually evaluated, ◎ in the case of being crushed in the same form as the existing aluminum crash box. The case where a burst occurred in a part of the box is indicated by ○, when the shape of the crash box is destroyed, and △ and × when the shape of the crash box is completely destroyed and falls off.

* Breaking form: Using a specimen, after colliding according to standard measurement ASTM D3763 at low temperature (-30 ℃), the breaking form is visually evaluated, and if there is no breakage of the specimen due to impact, ductile or impact When the specimen was broken by, it was shown as brittle.

division Example Comparative example One 2 3 One 2 3 4 Surface impact energy (room temperature) 20 23 25 20 25 31 18 Surface impact energy (low temperature) 24 26 32 20 22 29 19 Buckling form △ ○ ◎ × △ × × Rupture form ductility ductility ductility Brittle Brittle Brittle Brittle

As shown in Table 2, in the case of Examples 1 to 3 prepared according to the present invention, the crash safety performance is excellent, and having a similar or equivalent level of buckling and fracture shape to the existing aluminum crash box I could confirm.

On the other hand, in Comparative Example 1, which did not contain the polypropylene-acrylic compound graft copolymer additive, the crash safety performance was lowered, and when the crash was tested, the buckling shape was not realized, and the crash box shape was completely destroyed and fell off. , In the case of Comparative Example 2, in which the rupture form was broken due to the collision, the polypropylene block copolymer was contained in a trace amount, and the high crystalline polypropylene block copolymer was excessively contained, the rupture shape was broken by the collision. It was confirmed that this occurred, and in the case of Comparative Example 3 without crystallinity of 30 to 47% polypropylene block copolymer, the buckling shape was not implemented, the shape of the crash box was completely destroyed and fell off, and the fractured shape collided It was confirmed that cracking occurred. In addition, in the case of Comparative Example 4 in which the crystallinity does not include a polypropylene block copolymer having a crystallinity of 48 to 60%, the crash safety performance is deteriorated, and when the crash is tested, the buckling shape is not implemented and the crash box is completely shaped. It was destroyed and fell off, and it was confirmed that the fractured shape was caused by the collision.

From this, the present inventors use a polypropylene block copolymer in combination with a high crystalline polypropylene block copolymer, and when a specific filler and additive are included, the collision safety performance is excellent, and the buckling and fracture shape of the metal during collision are excellent. It was confirmed that a thermoplastic resin composition implemented in the same form as the material can be implemented.

Claims (16)

30 to 47% polypropylene block copolymer with a crystallinity of 30 to 47%, 10 to 40% by weight of a polypropylene block copolymer with a crystallinity of 48 to 60%, 10 to 40% by weight of a polyolefin elastomer, 1 to 15% by weight of a filler, and A thermoplastic resin composition comprising 0.1 to 5% by weight of a polypropylene-acrylic compound graft copolymer. According to claim 1,
The crystallinity of 30 to 47% polypropylene block copolymer and the polypropylene block copolymer having a crystallinity of 48 to 60% is a thermoplastic resin composition, characterized in that each is an ethylene-propylene block copolymer. According to claim 2,
The crystallinity of 30 to 47% polypropylene block copolymer is a thermoplastic resin composition, characterized in that the ethylene content is 1 to 30% by weight. According to claim 2,
The polypropylene block copolymer having a crystallinity of 48 to 60% is a thermoplastic resin composition, characterized in that the ethylene content is 1 to 25% by weight. According to claim 1,
The polyolefin elastomer is a thermoplastic resin composition, characterized in that it is a copolymer of ethylene and α-olefin. According to claim 1,
The filler is a thermoplastic filler composition, characterized in that the mineral filler (mineral filler). The method of claim 6,
The mineral filler is a thermoplastic resin composition, characterized in that at least one selected from the group consisting of calcium carbonate, talc, mica and silica. According to claim 1,
The thermoplastic resin composition further comprises a nucleating agent. The method of claim 8,
The nucleating agent is a thermoplastic resin composition, characterized in that at least one selected from the group consisting of calcium hydroxide and wollastonite. According to claim 1,
The thermoplastic resin composition is a thermoplastic resin composition, characterized in that it has a beta-crystal (β-modification) form. According to claim 1,
The thermoplastic resin composition is a thermoplastic resin composition, characterized in that the shape of the fracture due to collision is ductile (ductile) fracture. According to claim 1,
The thermoplastic resin composition is a thermoplastic resin composition, characterized in that the surface impact energy of -30 ℃ 23 J or more. A molded article comprising the thermoplastic resin composition according to any one of claims 1 to 12. The method of claim 13,
The molded article is a molded article comprising a continuous fiber composite (Continuous fiber thermoplastic). The method of claim 14,
The molded article is a molded article, characterized in that the thermoplastic resin composition and the insert injection molding of the continuous fiber composite material. The method of claim 13,
The molded article is a molded article characterized in that the molded article for a vehicle back beam (back beam).