KR101613182B1 - A thermoplastic resin composite composition for partially cross-linked polypropylene - Google Patents

Abstract

The present invention relates to a thermoplastic resin composite composition for partially crosslinked polypropylene and a partially crosslinked polypropylene prepared by using the composition, wherein the composition comprises: 25 to 70 parts by weight of a crystalline polypropylene resin; 15 to 45 parts by weight of a polyethylene polymer; 5 parts by weight to 25 parts by weight of ethylene-propylene rubber; 0.015 part by weight to 0.03 part by weight peroxide; 0.3 to 0.6 parts by weight of silicon hydride; And 3 parts by weight to 7 parts by weight of a crosslinking accelerator, it is possible to simultaneously improve mechanical properties such as rigidity and impact strength and scratch resistance.

Description

[0001] The present invention relates to a thermoplastic resin composite composition for partially crosslinked polypropylene,

The present invention relates to a thermoplastic resin composite composition for partially crosslinked polypropylene and a partially crosslinked polypropylene prepared using the same.

In recent years, various methods and materials have been developed in the plastics industry to meet the trends of environment friendly, high sensitivity, light weight, and high functionality. Of these, the crash pad part is attached to the bottom of the front glass of the driver's seat as an internal part of the car. The crash pad is attached to the lower part of the front glass of the driver's seat and houses the air conditioner, radio, watch, ashtray, And the like. Since the crash pad part is operated during operation, it is an important component in terms of design, convenience, and safety.

Generally, according to the manufacturing method and the material / structure applied, the crash pad can be roughly divided into two types. In other words, the crash pad is separated into a soft crash pad (Soft C / Pad) and a hard crash pad (Hard C / Pad), and various crush pad manufacturing methods can be selected according to vehicle type and construction method specification. The soft crash pad is composed of three single skin layers, a foam layer and a core layer, so that a soft touch and a cushion feel can be felt in appearance and touch. On the other hand, hard crash pads consist of a single core layer, which is produced by a plastic injection process. In terms of appearance and feel, the hard crash pad has a lower soft touch than the soft crash pad. In addition, in the hard crash pad, a painting process is added to improve the appearance quality.

In particular, representative automobile manufacturers in Korea recently selected 10 preliminary tasks for each company through survey of consumer complaints. In the case of interior materials, scratch resolution is the most important, showing how urgent the development of scratch-resistant crash pad products is. This is usually a problem that can be solved by adding an internal scratch or coating process, but in this case, a coating process is added, which complicates the manufacturing process, which causes another problem that the product cost increases. In addition, it is difficult to cope with environmental regulations that are gradually strengthened due to the problem that excessive volatile organic compounds (VOCs) are emitted from the organic solvent used in the coating process.

On the other hand, as the demand for polymer materials gradually becomes more functional, performance and diversified, a few industries are trying to reduce the use of harmful substances until the recycling stage of the final product, while maintaining the original performance of the uni- The material requires a single, simplified material. Therefore, it is absolutely necessary to apply a thermoplastic partially cross-linked polypropylene resin (XLPP) which can exhibit a performance that can not be obtained as a single material.

Polypropylene (PP) has not only high chemical stability, but also excellent corrosion resistance, and is used as various parts materials in the whole industry as lightweight materials, and many studies have been made. However, the thermoplastic partially cross-linked polypropylene using this has been studied relatively little.

Since the polypropylene in the olefin resin does not have a double bond in the main chain, it is difficult to produce the partially cross-linked polypropylene by cutting the main chain at the time of processing, and there is a problem that it is difficult to impart functionality to the polypropylene.

Replacing CrashPad component materials with thermoplastic, partially crosslinked polypropylene resins not only improves scratch resistance, but also enables mass production of complex parts through mold design. In addition, when crush pads made of thermoplastic, partially cross-linked polypropylene are produced by injection molding, they can be modularized to integrate each component and to maximize the weight reduction ratio. Moreover, modularization is at the core of the automotive industry, and it is also a question of the survival of each automobile manufacturer. For this reason, the use of thermoplastic partially cross-linked polypropylene is expected to expand gradually.

Therefore, there is an urgent need for a composition capable of easily producing a thermoplastic partially cross-linked polypropylene resin and the development and development of a thermoplastic cross-linked polypropylene using the same.

The present invention provides a thermoplastic resin composite composition for a thermoplastic partially crosslinked polypropylene having a high stiffness, a high impact resistance and a high scratch resistance, a low distortion and a price competitiveness, and a thermoplastic partially crosslinked polypropylene prepared using the same .

The present invention provides, as means for solving the above problems,

25 to 70 parts by weight of a crystalline polypropylene resin;

15 to 45 parts by weight of a polyethylene polymer;

5 to 25 parts by weight of ethylene-propylene rubber;

0.015 part by weight to 0.03 part by weight peroxide;

0.3 to 0.6 parts by weight of silicon hydride; And

And 3 parts by weight to 7 parts by weight of a crosslinking accelerator.

There is provided a thermoplastic resin composite composition for partially crosslinked polypropylene.

The present invention also provides, as another means for solving the above problems,

There is provided a partially crosslinked polypropylene produced by using the thermoplastic resin composite composition for partially crosslinked polypropylene according to the present invention as a raw material.

The thermoplastic resin composite composition for partially crosslinked polypropylene of the present invention can improve physical properties, particularly rigidity and impact strength, and scratch resistance of partially crosslinked polypropylene at the time of producing partially crosslinked polypropylene using the same.

1 is a schematic view showing a process for producing a partially crosslinked polypropylene using a thermoplastic resin composite composition for partially crosslinked polypropylene according to the present invention as a raw material.
2 is a schematic diagram showing a process (A) of grafting polypropylene and a process (B) of cutting the main chain of the polypropylene using silicon hydride and peroxide.
3 is a schematic view showing a process of partially crosslinking polypropylene grafted with silicon hydride using a crosslinking accelerator to partially crosslink polypropylene.
4 is a photograph showing black spots on the surface of a partially crosslinked polypropylene sample observed using a microscope in an extrusion appearance analysis according to the present invention.

The present invention relates to a resin composition comprising 25 to 70 parts by weight of a crystalline polypropylene resin; 15 to 45 parts by weight of a polyethylene polymer; 5 parts by weight to 25 parts by weight of ethylene-propylene rubber; 0.015 part by weight to 0.03 part by weight peroxide; 0.3 to 0.6 parts by weight of silicon hydride; And 3 parts by weight to 7 parts by weight of a crosslinking accelerator. The present invention also relates to a thermoplastic resin composite composition for partially crosslinked polypropylene.

Hereinafter, the thermoplastic resin composite composition for partially crosslinked polypropylene of the present invention will be specifically described.

The thermoplastic resin composite composition for partially crosslinked polypropylene of the present invention contains 25 to 70 parts by weight, preferably 30 to 62 parts by weight of a crystalline polypropylene resin as a base resin per 100 parts by weight of the composition . When the content of the crystalline polypropylene resin is less than 25 parts by weight in the composition of the present invention, the moldability of the partially crosslinked polypropylene is lowered and the shrinkage increases in the partially crosslinked polypropylene. When the content exceeds 62 parts by weight, the impact strength and crosslinking ratio of the partially crosslinked polypropylene may be lowered. Therefore, it is preferable to use the polypropylene within the above-mentioned limited range.

As used herein, the term "parts by weight" means weight ratios.

The crystalline polypropylene resin may be a polypropylene homopolymer or a polypropylene copolymer, and preferably a polypropylene copolymer.

The polypropylene homopolymer is preferably an isotactic polymer containing 99 wt% or more of a propylene monomer because the isotactic polymer has a high crystallinity, a high melting point and a high mechanical strength.

The polypropylene copolymer is a copolymer of a propylene monomer and an ethylene monomer and contains an ethylene monomer in an amount of 1 wt% to 20 wt%, preferably 7 wt% to 15 wt%, so that the high mechanical properties of the polypropylene homopolymer The impact resistance can be greatly improved without significantly lowering the strength.

The isotactic index (measured by ¹³ C-NMR) of the crystalline polypropylene resin may be 80% or more, preferably 85% to 90%. If the isotactic index is less than 80%, the rigidity and surface hardness of the partially crosslinked polypropylene molded product may be poor, and if the isotactic index exceeds 90%, the impact strength of the partially crosslinked polypropylene may be lowered .

The weight average molecular weight of the crystalline polypropylene resin may be 100,000 to 150,000. By controlling the weight average molecular weight of the crystalline polypropylene resin within the above range, the impact strength and rigidity of the partially crosslinked polypropylene material can be improved and molding and processing can be facilitated. The weight average molecular weight in the present invention is measured by high temperature gel permeation chromatography (GPC).

The melt index of the crystalline polypropylene resin is from 80 g / 10 min to 120 g / 10 min, preferably from 90 g / 10 min to 110 g / 10 min at a temperature of 230 ° C and a load of 2.16 kg , More preferably from 95 g / 10 min to 105 g / 10 min. If the melt index of the crystalline polypropylene resin is less than 80 g / 10 min, the flowability and moldability of the partially crosslinked polypropylene may be deteriorated. When the melt index of the crystalline polypropylene resin exceeds 120 g / 10 min, The fluidity is excessively increased and the rigidity of the material is lowered, and the occurrence of flashes during the injection molding process may increase.

INDUSTRIAL APPLICABILITY The thermoplastic resin composite composition for partially crosslinked polypropylene of the present invention can prevent the main chain from being cut when the crystalline polypropylene resin is grafted during the production of the partially crosslinked polypropylene, 15 to 45 parts by weight, preferably 20 to 40 parts by weight, of the polyethylene polymer with respect to 100 parts by weight of the composition.

If the content of the polyethylene polymer in the composition of the present invention is less than 15 parts by weight, the cross-linking ratio of the partially crosslinked polypropylene may be low and the scratch resistance may be poor. When the content of the polyethylene polymer exceeds 45 parts by weight, The crosslinking ratio of the crosslinked polypropylene is so high that the moldability and processability of the partially crosslinked polypropylene may be poor.

In the present invention, the low crosslinking ratio of the partially crosslinked polypropylene may mean that the crosslinking ratio is less than 20%, and the crosslinking ratio of the partially crosslinked polypropylene is too high if the crosslinking ratio exceeds 35% It can mean.

Generally, when a partially crosslinked polypropylene is produced by using a crystalline polypropylene resin as a single material, a radical is imparted to the crystalline polypropylene resin through pyrolysis of the peroxide, and crystallization is carried out by silylation using silicon hydride. It is difficult to form a grafted polypropylene resin by cutting the main chain of the crystalline polypropylene resin by a β-scission reaction in the process of grafting the polypropylene resin.

However, in the present invention, by using the polyethylene polymer together with the crystalline polypropylene resin, the main chain of the crystalline polypropylene resin is prevented from being broken, and as a result, the polypropylene resin grafted through the silylation can be easily formed have. This is because the polyethylene polymer has a binding energy lower than that of the polypropylene resin so that the polyethylene polymer is first decomposed instead of cutting the main chain of the crystalline polypropylene resin in the process of adding radicals through pyrolysis of the peroxide.

The melt index of the polyethylene polymer is 55 g / 10 min to 70 g / 10 min, preferably 60 g / 10 min to 65 g / 10 min, at a temperature of 190 ° C and a load of 2.16 kg (as per ASTM D 1238). If the melt index of the polyethylene is less than 55 g / 10 min, the flowability and moldability of the partially crosslinked polypropylene may be deteriorated, and if the melt index of the polyethylene polymer exceeds 70 g / 10 min, Strength and heat resistance may be poor.

The weight average molecular weight of the polyethylene polymer may be from 10,000 to 100,000. By controlling the weight average molecular weight of the polyethylene polymer within the above range, it is possible to secure the fluidity in the production of the material for the thin film injection skin, and to facilitate the production of the partially crosslinked polypropylene material and the processing of the injection skin.

In one embodiment of the present invention, the polyethylene polymer may be a low density polyethylene (LDPE) resin comprising an alpha (alpha) -olefin having four or more carbon atoms.

The thermoplastic resin composite composition for partially crosslinked polypropylene of the present invention is prepared by mixing 5 parts by weight to 25 parts by weight of an ethylene-propylene rubber with respect to 100 parts by weight of the composition in order to improve the interfacial bonding force between the crystalline polypropylene resin and the polyethylene polymer , Preferably 10 parts by weight to 20 parts by weight.

In the composition of the present invention, the ethylene-propylene rubber may function as a coupling agent or an adhesive between the crystalline polypropylene resin and the polyethylene polymer. If the content of the ethylene-propylene rubber is less than 5 parts by weight, the interfacial bonding force between the resins may be weakened and the dimensional stability may decrease. When the content of the ethylene-propylene rubber exceeds 25 parts by weight, Therefore, it is preferable to use in the above-mentioned range.

The ethylene-propylene rubber has a melt index of 50 g / 10 min to 70 g / 10 min, preferably 55 g / 10 min to 65 g / 10 min, at a temperature of 230 ° C and a load of 2.16 kg. When the melt index of the ethylene-propylene rubber is less than 50 g / 10 min, the flowability and moldability of the partially crosslinked polypropylene may be deteriorated. When the melt index of the ethylene-propylene rubber exceeds 70 g / 10 min, The mechanical strength and heat resistance of the crosslinked polypropylene may be poor.

Also, the ethylene-propylene rubber may have a Mooney viscosity ML1 + 4 (121 캜) of 5 to 70, preferably 5 to 30. When the pattern viscosity of the ethylene-propylene rubber is less than 5, the mechanical strength and dimensional stability of the partially crosslinked polypropylene may be decreased. When the pattern viscosity of the ethylene-propylene rubber exceeds 30, the fluidity of the partially crosslinked polypropylene Resulting in appearance problems and moldability problems.

The glass transition temperature of the ethylene-propylene rubber is preferably -65 ° C to -50 ° C. When the glass transition temperature of the ethylene-propylene rubber is less than -65 ° C, the rigidity and heat resistance of the partially crosslinked polypropylene may be deteriorated. When the glass transition temperature is more than -50 ° C, the low temperature impact resistance of the partially crosslinked polypropylene may be deteriorated.

The ethylene-propylene rubber may comprise 100 parts by weight of the polypropylene matrix and 60 to 70 parts by weight of the ethylene monomer. By limiting the content of the ethylene monomer in the ethylene-propylene rubber within the above range, the interfacial compatibility between the crystalline polypropylene resin and the polyethylene polymer can be maximized.

The thermoplastic resin composite composition for partially crosslinked polypropylene of the present invention contains 0.015 part by weight to 0.03 part by weight of peroxide relative to 100 parts by weight of the composition in order to react with the crystalline polypropylene resin to give a radical.

When the content of the peroxide is less than 0.015 part by weight, the crosslinking ratio of the partially crosslinked polypropylene may be low and the scratch resistance may be poor. When the content of the peroxide exceeds 0.03 parts by weight, the crosslinking ratio of the partially crosslinked polypropylene is too high The shape and workability of the partially crosslinked polypropylene are poor, and austenite such as black spots may be poor when the extrusion appearance analysis is performed.

The kind of the peroxide is not particularly limited, but is preferably selected from the group consisting of di- (2,4-dichlorobenzoyl) -peroxide, dibenzoyl peroxide, T-butyl peroxybenzoate, 1,1-di- (tert-butylperoxy) -3,3,5-trimethylcyclohexane (1,1- 3,3,5-trimethylcyclohexane, dicumyl peroxide, di- (2-t-butylperoxyisopropyl) benzene, tert-butyl 2,5-dimethyl-2,5di (t-butylperoxy) -hexane, t-butylcumylperoxide, 2,5- Di-t-butylperoxide, and mixtures thereof. ≪ RTI ID = 0.0 >

The weight average molecular weight of the peroxide is not particularly limited, but is preferably 330 to 340. [

The peroxide may have a half-life characteristic of 1 hour at a temperature of 130 ° C to 140 ° C, preferably at a temperature of 134 ° C. When the peroxide has a half-life of 1 hour at a temperature of less than 130 캜, initial activation of the peroxide during extrusion processing is too large to uniformly crosslink the crystalline polypropylene resin, and the peroxide is heated at a temperature exceeding 140 캜 for 1 hour , The activity of the peroxide during extrusion processing becomes too low to leave residues after the process and may be insufficient to give the desired radical properties through reaction with the crystalline polypropylene resin.

The thermoplastic resin composite composition for partially crosslinked polypropylene of the present invention is obtained by reacting 100 parts by weight of the composition with hydrogen peroxide in order to react with a radical in a crystalline polypropylene resin produced by a polyethylene polymer and a peroxide to graft the crystalline polypropylene resin 0.3 to 0.6 parts by weight of silicon.

If the content of the silicon hydride is less than 0.3 part by weight, the main chain portion of the crystalline polypropylene resin may be cut due to an excessive amount of peroxide. When the content of the silicon hydride exceeds 0.6 parts by weight, The gas may be generated by residual silicon hydride after the grafting.

In one embodiment of the invention, the weight ratio of silicon hydride / peroxide may preferably be 16 to 20, more preferably 20. When the weight ratio is less than 16, the crosslinking ratio of the partially crosslinked polypropylene is low and scratch resistance may be poor. When the weight ratio is more than 20, gas is generated due to excess silicon hydride and the scratch resistance is judged it's difficult.

The silicon hydride may include one vinyl group and one to three alkoxy groups. The vinyl group in the silicon hydride reacts with radicals in the crystalline polypropylene resin produced by the polyethylene polymer and the peroxide to perform grafting of the crystalline polypropylene resin.

When the vinyl group is not present in the silicon hydride, it is difficult to graft the crystalline polypropylene resin and it is difficult to control the crosslinking rate of the partially crosslinked polypropylene when the number of vinyl groups in the silicon hydride is two or more. Therefore, It is difficult to control the molding process and the reaction extrusion process.

The alkoxy group contained in the silicon hydride is preferably an alkoxy group having 1 to 6 carbon atoms, more preferably 1 to 3 carbon atoms.

In the composition of the present invention, the silicon hydride is preferably selected from the group consisting of vinylsilane, vinylmethoxysilane, vinyldimethoxysilane, vinyltrimethoxysilane, vinylethoxysilane, vinyldiethoxysilane, vinyltriethoxysilane, vinylpropoxy Silane, vinyldipropoxysilane and vinyltripropoxysilane, and more preferably at least one selected from the group consisting of vinylsilane, vinylmethoxysilane, vinyldimethoxysilane and vinyltrimethoxysilane, It can be one or more selected.

The thermoplastic resin composite composition for partially crosslinked polypropylene of the present invention may be prepared by mixing 3 to 7 parts by weight of a crosslinking accelerator with respect to 100 parts by weight of the composition so as to partially promote crosslinking between the crystalline polypropylene resins grafted with silicon hydride .

If the content of the crosslinking accelerator is less than 3 parts by weight, the crosslinking ratio between the crystalline polypropylene resins grafted with silicon hydride may be low and the scratch resistance may be poor. If the content of the crosslinking accelerator exceeds 7 parts by weight , The crosslinking ratio between the crystalline polypropylene resins grafted with silicon hydride is too high, so that the moldability and workability of the partially crosslinked polypropylene may be poor.

As the crosslinking accelerator, an organotin compound may be used, and an octyl tin compound or a butyl tin compound may be used.

The thermoplastic resin composite composition for partially crosslinked polypropylene of the present invention may further comprise 2 to 4 parts by weight of the compatibilizing agent per 100 parts by weight of the composition. When the partially crosslinked polypropylene resin of the present invention is used together with a filler used for reinforcing the rigidity, the compatibilizing agent functions as a coupling agent or an adhesive between the partially crosslinked polypropylene resin and the filler to improve the interfacial bonding force therebetween .

If the content of the compatibilizing agent is less than 2 parts by weight, the compatibilizing agent may be too small and the interfacial bonding force between the partially crosslinked polypropylene resin and the rigid reinforcing filler may be poor. When the content of the compatibilizing agent exceeds 4 parts by weight, The physical properties may deteriorate, and it may be uneconomical.

The compatibilizer may be a furan-based polymer, or a copolymer comprising monomers containing vinyl acetal. In particular, the compatibilizing agent is a polypropylene homopolymer grafted with an unsaturated carboxylic acid or an acid anhydride thereof selected from the group consisting of maleic acid, acrylic acid, methacrylic acid, itaconic acid, crotonic acid, cinnamic acid and citraconic acid, And may preferably be a maleic anhydride graft polypropylene.

When polypropylene grafted with an unsaturated carboxylic acid or an acid anhydride thereof is used, the content of the unsaturated carboxylic acid or an acid anhydride thereof is preferably 0.5 to 10 parts by weight based on 100 parts by weight of the grafted polypropylene, May be 5 parts by weight to 8 parts by weight. If the content of the unsaturated carboxylic acid or its acid anhydride is less than 0.5 parts by weight, the function of the compatibilizing agent may be deteriorated. If the content of the unsaturated carboxylic acid or acid anhydride exceeds 10 parts by weight, the physical properties of the final product may be deteriorated.

The weight average molecular weight of the compatibilizing agent is not particularly limited, but is preferably 100 to 5,000, more preferably 300 to 3,000. If the weight average molecular weight of the compatibilizing agent is less than 100 or more than 5,000, the physical properties of the final product may be deteriorated.

The thermoplastic resin composite composition for partially crosslinked polypropylene of the present invention may further comprise 0.1 to 0.5 parts by weight of an additive per 100 parts by weight of the composition in order to improve the performance and processing characteristics of the molded article of the composition.

The additive may be at least one selected from the group consisting of a flame retardant, a lubricant, an antioxidant, a light stabilizer, a release agent, a pigment, an antistatic agent, a metal deactivator, glass fiber and a coupling agent.

Specific examples of the flame retardant, lubricant, antioxidant, light stabilizer, mold release agent, pigment, antistatic agent, metal deactivator, glass fiber and coupling agent used as the additive are not particularly limited and those conventionally used in this technical field may be used .

The thermoplastic resin composite composition for partially crosslinked polypropylene of the present invention may further comprise 10 to 60 parts by weight, preferably 35 to 45 parts by weight, of the rigid reinforcing filler per 100 parts by weight of the composition. The rigid reinforcing filler functions as a component exhibiting high rigidity of the partially crosslinked polypropylene. By controlling the content of the rigid reinforcing filler within the above range, the present invention can improve moldability and productivity while maintaining an appropriate level of mechanical properties.

In order to improve the interfacial bonding force between the partially crosslinked polypropylene resin and the rigid reinforcing filler through the compatibilizer, the rigid reinforcing filler may be surface treated with a silane-based polymer. The silane-based polymer surface-treated on the rigid reinforcing filler can improve the interfacial bonding force between the partially crosslinked polypropylene resin and the rigid reinforcing filler through chemical bonding with the compatibilizer, specifically, covalent bonding.

As the rigid reinforcing filler, long glass fiber, which is an inorganic reinforcing material, or carbon fiber, which is an organic reinforcing material, can be used.

When the long reinforcing fiber is used as the rigid reinforcing filler, the long fiber includes the alkali metal in an amount of 1 wt% to 10 wt%, the diameter of the long fiber is 5 mu m to 24 mu m, and the modulus of elasticity is 70 GPa or more.

When the carbon fiber is used as the rigid reinforcing filler, the carbon fiber is produced by using polyacrylonitrile or silicon carbide as a pitch-based carbon fiber as a precursor, and the diameter of the carbon fiber is 5 to 20 占 퐉, and a modulus of elasticity of 230 Gpa or more.

The present invention also relates to a partially crosslinked polypropylene prepared by using the thermoplastic resin composite composition for partially crosslinked polypropylene according to the present invention as a raw material.

The partially crosslinked polypropylene can be produced by an injection molding method using the thermoplastic resin composite composition for partially crosslinked polypropylene according to the present invention as a raw material.

The partially crosslinked polypropylene of the present invention includes without limitation all those prepared using the thermoplastic resin composite composition for partially crosslinked polypropylene according to the present invention as a raw material.

 The injection molding method includes conditions and processes commonly used in the art, and the conditions and the process are not particularly limited.

The partially crosslinked polypropylene prepared using the thermoplastic resin composite composition for partially crosslinked polypropylene according to the present invention as a raw material may have a crosslinking ratio of 20% to 35%.

The partially crosslinked polypropylene produced from the thermoplastic resin composite composition for a partially crosslinked polypropylene of the present invention as a raw material is excellent in mechanical properties such as rigidity and impact strength as well as excellent in scratch resistance and easy to be processed, It can be widely used not only for interior parts of automobiles but also for home appliances such as cleaners and the like.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic view showing a process for producing a partially crosslinked polypropylene using a thermoplastic resin composite composition for partially crosslinked polypropylene according to the present invention as a raw material. FIG. As shown in Fig. 1, the process for producing a partially crosslinked polypropylene is roughly divided into a polypropylene (PP) grafted with silicon hydride to form a grafted polypropylene (hereinafter referred to as "graft polymer") Step (first step); And a step (second step) of forming a partially cross-linked polypropylene (hereinafter referred to as "XLPP") by crosslinking the silicon hydride portions of the Graft polymer with a cross-linking accelerator.

FIG. 2 is a schematic view showing a process of grafting polypropylene and a process of cutting the main chain of polypropylene using silicon hydride and peroxide. As shown in Fig. 2, when XLPP is produced using a crystalline polypropylene resin as a single material without using a polyethylene polymer and an ethylene-propylene rubber (Fig. 2B), the crystalline poly A main chain of the crystalline polypropylene resin is cut by a beta-scission reaction while radicals are added to the propylene resin and the crystalline polypropylene resin is grafted through silylation using silicon hydride It is difficult to form a graphemer. However, when XLPP is produced using a polyethylene polymer (not shown) and an ethylene-propylene rubber (not shown) together with a crystalline polypropylene resin (Fig. 2 A), the crystalline polypropylene resin The main chain can be prevented from being cut off, and as a result, the graftomer can be easily formed through silylation using silicon hydride.

FIG. 3 is a schematic view showing a process for producing XLPP by partially crosslinking a Grafter using a crosslinking accelerator. As shown in FIG. 3, when a crosslinking accelerator is used, a condensation reaction occurs between the silicon hydrides of the graftomer and the graftomers are partially crosslinked to produce XLPP.

[ Example ]

In the following Examples, the present invention will be described in more detail with reference to Examples according to the present invention and Comparative Examples not based on the present invention, but the scope of the present invention is not limited by the following Examples.

Example  One

40 parts by weight of a polyethylene polymer having a melt index of 60 g / 10 min (measured at a temperature of 190 캜 and a load of 2.16 kg) and a weight average molecular weight of 10,000 (MB9500, manufactured by LG Chemical); As an ethylene-propylene rubber, 20 parts by weight of an ethylene-propylene rubber polymer (Vistamaxx 2125, manufactured by ExxonMobil Chemical) having a melt index of 60 g / 10 min (measured at 230 ° C and a load of 2.16 kg) 0.03 part by weight of di (tert-butylperoxyisopropyl) benzene (Perkadox 14S, manufactured by Akzo Nobel) having a half life of 1 hour at 134 캜 as peroxide; 0.6 part by weight of vinyltrimethoxysilane as silicon hydride; 3 parts by weight of maleic anhydride graft polypropylene (GP090C, Hyundai EP) as a compatibilizing agent; And 0.3 parts by weight of an antioxidant (ADK-A21B, manufactured by ADEKA CORPORATION) as an additive were first mixed using a super mixer, and then 100 g / 10 min (temperature of 230 DEG C and 2.16 kg ) And 31.07 parts by weight of a polypropylene homopolymer having a weight average molecular weight of 100,000 (CB5290, manufactured by KANPOL Co., Ltd.) were added to the above mixture and uniformly mixed via a melt kneader to obtain a grafted silicon hydride To prepare a polypropylene resin (graft polymer). 5 parts by weight of the obtained graft polymer was sufficiently uniformly mixed with an octyl tin crosslinking accelerator (XW-200, Hyundai EP), and the mixture was injection molded to obtain a partially crosslinked polypropylene resin (34% Lt; / RTI >

Example  2

The content of the polyethylene polymer (MB9500, manufactured by LG Chemical) was changed from 40 parts by weight to 20 parts by weight, and the content of the ethylene-propylene rubber (CB5290, manufactured by Kyorin Chemical Co., Ltd.) was changed from 31.07 parts by weight to 61.385 parts by weight. The content of di (tert-butylperoxyisopropyl) benzene (Perkadox 14S, manufactured by Akzo Nobel) was changed from 0.03 parts by weight to 0.015 parts by weight (manufactured by Akzo Nobel) by changing the content of the polymer (Vistamaxx 2125, manufactured by ExxonMobil Chemical) And a partially crosslinked polypropylene resin (crosslinking ratio of 23%) was prepared in the same manner as in Example 1, except that the content of vinyltrimethoxysilane was changed from 0.6 part by weight to 0.3 part by weight.

Comparative Example  One

The procedure of Example 1 was repeated except that the content of polypropylene homopolymer (CB5290, manufactured by Kyorin Chemical Co., Ltd.) was changed from 31.07 parts by weight to 71.07 parts by weight, and a polyethylene polymer was not used. The partially crosslinked polypropylene resin Rate measurement impossible).

Comparative Example  2

A partially crosslinked polyethylene resin (89% by weight) was obtained in the same manner as in Example 1, except that the crystalline polypropylene resin was not used and the content of the polyethylene polymer (MB9500, manufactured by LG Chemical) was changed from 40 parts by weight to 71.07 parts by weight. % Crosslinking ratio).

Comparative Example  3

As a crystalline polypropylene resin, a melt index of 33 g / 10 min (measured at a temperature of 230 캜 and a load of 2.16 kg) and a weight average molecular weight of 100,000 instead of 31.07 parts by weight of a polypropylene homopolymer (CB5290, Except that 31.07 parts by weight of a polypropylene homopolymer (CB5230, produced by Daehan Kogyo Co., Ltd.) as a polyethylene polymer was used in place of 40 parts by weight of a polyethylene polymer (MB9500, manufactured by LG Chemical Co., Ltd.) 40 parts by weight of a polyethylene polymer (MB9205, manufactured by LG Chemical Co., Ltd.) having a melt index of 10,000 and a weight average molecular weight of 10,000, and 20 parts by weight of an ethylene-propylene rubber (trade name: Vistamaxx 2125, manufactured by ExxonMobil Chemical) An ethylene-propylene rubber polymer (Vistamaxx 1120, Exxonmobil Chemi) having a melt index of 30 g / 10 min (measured at a temperature of 230 ° C and a load of 2.16 kg) (crosslinking ratio of 30%) was prepared in the same manner as in Example 1, except that 20 parts by weight of a partially crosslinked polypropylene resin was used.

Comparative Example  4

The content of di (tert-butylperoxyisopropyl) benzene (Perkadox 14S, manufactured by Akzo Nobel) was changed from 0.03 part by weight to 31.09 parts by weight, and the content of polypropylene homopolymer (CB5290, A partially crosslinked polypropylene resin (crosslinking ratio of 12%) was prepared in the same manner as in Example 1, except that the amount of the crosslinking agent was changed to 0.01 part by weight.

Comparative Example  5

The content of di (tert-butylperoxyisopropyl) benzene (Perkadox 14S, manufactured by Akzo Nobel) was changed from 0.03 part by weight to 31.05 parts by weight, and the content of polypropylene homopolymer (CB5290, A partially crosslinked polypropylene resin (crosslinking ratio of 40%) was prepared in the same manner as in Example 1, except that the amount of the crosslinking agent was changed to 0.05 part by weight.

Comparative Example  6

Except that the content of polypropylene homopolymer (CB5290, manufactured by Kyorin Chemical Co., Ltd.) was changed from 31.07 parts by weight to 31.22 parts by weight, and the content of vinyltrimethoxysilane was changed from 0.6 parts by weight to 0.45 parts by weight. A partially crosslinked polypropylene resin (crosslinking ratio of 15%) was prepared in the same manner.

Comparative Example  7

Except that the content of polypropylene homopolymer (CB5290, manufactured by Kyorin Chemical Co., Ltd.) was changed from 31.07 parts by weight to 30.92 parts by weight, and the content of vinyltrimethoxysilane was changed from 0.6 parts by weight to 0.75 parts by weight. A partially crosslinked polypropylene resin (crosslinking ratio of 37%) was prepared in the same manner.

Test Example

The specimens were produced using the partially crosslinked polypropylene resin prepared in Examples 1 and 2 and Comparative Examples 1 and 3 to 7 and the partially crosslinked polyethylene resin prepared in Comparative Example 2 and then melt index , Crosslinking rate, extrusion appearance analysis, tensile strength, hardness, impact strength and scratch resistance were measured.

(1) Before preparing the partially crosslinked polyethylene resin, the melt index of each composition was measured at a temperature of 230 캜 and under a load condition of 2.16 kg.

(2) Crosslinking ratio was extracted by Soxhlet extraction method. Specifically, a predetermined amount of the XLPP sample is pulverized by a method of ASTM D2765 to prepare a powder, and the pulverized XLPP sample is put into a Timble Filter. Subsequently, by using xylene contained in a reactor connected to a cooler, The sample was circulated at 110 DEG C for 12 hours to dissolve all of the non-crosslinked components. Thereafter, the weight of the XLPP sample which was crosslinked and not dissolved relative to the weight of the XLPP sample which was initially put in was measured, and the crosslinking rate of each sample was measured by the following formula.

(3) The extrusion appearance analysis was performed by using a microscope to measure the number of black spots having a size of 12 μm or more per 30 cm × 40 cm width of the XLPP sample. The case where the number of the black spots is 30 or less is a state having normal appearance. 4 is a photograph showing black spots on the surface of a sample observed using a microscope in the extrusion appearance analysis.

(4) Tensile strength was measured according to ASTM D638 method.

(5) Hardness (Shore D) was measured according to ASTM D2240 method.

(6) The impact strength was measured according to the ASTM D256 method.

(7) The scratch resistance was measured according to the method of JIS K3718. Specifically, the surface of each specimen was scratched with the measuring conditions of the following Table 1, and the surface state of each specimen was evaluated according to the scratch resistance criteria shown in Table 2 below .

Item Condition Load (N {kgf}) 4.9 {0.5} Stroke (mm) 100 ± 5 Friction speed (mm / sec) 100




Scratcher

Number of scratches 1 time

Rating Scratch resistance criteria Scratch width (탆) Exterior 5  Less than 20 Almost no surface damage 4 100 or more and less than 200 No obvious surface damage is recognized 3 200 or more and less than 300 Fine surface damage is recognized 2 300 or more and less than 400 Whitening due to obvious surface damage One More than 400 Very severe surface damage

The results of sample composition and physical properties of Examples 1 and 2 and Comparative Examples 1 to 7 are shown in Table 3 below.

division
Example Comparative Example One 2 One 2 3 4 5 6 7









Furtherance



Polypropylene
(A) 31.07 61.385 71.07 - - 31.09 31.05 31.22 30.92 Polypropylene
(B) - - - - 31.07 - - - - Polyethylene
(A) 40 20 - 71.07 - 40 40 40 40 Polyethylene
(B) - - - - 40 - - - - EPR (A)
20 10 20 20 - 20 20 20 20 EPR (B)
- - - - 20 - - - - peroxide
0.03 0.015 0.03 0.03 0.03 0.01 0.05 0.03 0.03 Silicon hydride
0.6 0.3 0.6 0.6 0.6 0.6 0.6 0.45 0.75 Compatibilizer
3 3 3 3 3 3 3 3 3 additive
0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 Crosslinking accelerator
5 5 5 5 5 5 5 5 5




Properties






Melt Index
(g / 10 min) 75 88 150
More than 5 14 80 92 70 55 Crosslinking rate
(%) 34 23 - 89 30 12 40 15 37 Extrusion appearance analysis
(Black score) 24 5 - Processing
Impossible 20 gas
Occur 35 3 gas
Occur The tensile strength
(MPa) 17 23 16 - 25 12 19 13 27 Hardness
(Shore D) 63 77 103 - 65 43 50 53 68 Impact strength at room temperature
(J / m) 332 298 40 - 320 279 317 263 277 Scratch resistance
(Rating) 3.5 3 One - 3.5 2.5 3 2 Judgment
Impossible
Polypropylene (A): Polypropylene homopolymer having a melt index of 100 g / 10 min (CB5290, Korea Emulsification)
Polypropylene (B): Polypropylene homopolymer having a melt index of 33 g / 10 min (CB5230, Korea Emulsification)
Polyethylene (A): A polyethylene polymer having a melt index of 60 g / 10 min (MB9500, LG Chem)
Polyethylene (B): A polyethylene polymer having a melt index of 30 g / 10 min (MB9205, LG Chem)
EPR (A): An ethylene-propylene rubber (Vistamaxx 2125, Exxonmobil chemical) having a melt index of 60 g /
EPR (B): Ethylene-propylene rubber (Vistamaxx 1120, Exxonmobil chemical) having a melt index of 30 g /
Peroxide: di (tert-butylperoxyisopropyl) benzene (Perkadox 14S, Akzonobel)
Silicon hydride: Vinyltrimethoxysilane
Compatibilizer: maleic anhydride grafted polypropylene (GP090C, Hyundai EP)
Additives: Antioxidant (ADK-A21B, Adeka Korea)
Crosslinking accelerator: octyltin compound (XW 200, Hyundai EP)

With respect to the physical properties of the partially crosslinked polypropylene of the present invention, it is preferable that the melt index is 70 g / 10 min or more, the crosslinking ratio is 20% to 35%, the extrusion appearance analysis is 30 or less, the tensile strength is 13 MPa or more, The impact strength is preferably 250 J / m or more, and the scratch resistance is preferably 3 or more.

As shown in Table 3, in the case of the partially crosslinked polypropylene of Examples 1 and 2 according to the present invention, a melt index of 70 g / 10 min or more, a crosslinking ratio of 20% to 35%, an extrusion appearance analysis of 30 or less, 13 A shore D of 60 or more, a normal temperature impact strength of 250 J / m or more, and a scratch resistance of 3 or more.

On the other hand, in the case of Comparative Example 1 in which only a crystalline polypropylene resin and an ethylene-propylene rubber were used and a polyethylene polymer was not used, the main chain of the crystalline polypropylene resin was cut during the production of the partially crosslinked polypropylene, And thus the melt index is too high, so that the impact strength at room temperature is poor and the scratch resistance is also poor.

In addition, in the case of Comparative Example 2, in which only polyethylene polymer and ethylene-propylene rubber were used, and the crystalline polypropylene was not used, partially crosslinked polyethylene was produced, and the crosslinking ratio of the partially crosslinked polyethylene was too high, And it was impossible to process the material.

A crystalline polypropylene resin with a melt index of less than 80 g / 10 min, a polyethylene polymer with a melt index of less than 55 g / 10 min and an ethylene-propylene rubber with a melt index of less than 50 g / , The melt index was so low that processing and molding of the material was impossible due to the high viscosity.

Further, in the case of Comparative Example 4 using less than 0.015 part by weight of peroxide, the crosslinking rate of the crystalline polypropylene resin was very low in the course of producing the partially crosslinked polypropylene, and thus the scratch resistance was poor, and tensile strength and hardness (shore D) And the amount of silicon hydride relative to the peroxide was excessive, so that gas was generated when the extrusion appearance analysis was performed due to the remaining amount of silicon hydride.

In the case of Comparative Example 5 in which the peroxide having a weight ratio exceeding 0.03 was used, the cross-linking ratio of the crystalline polypropylene resin was too high in the process of producing the partially crosslinked polypropylene, resulting in generation of a black spot on the surface during extrusion appearance analysis, , And hardness (shore D) were low, and moldability and workability were poor.

In the case of Comparative Example 6 in which the weight ratio of silicon hydride / peroxide was less than 16, the crosslinking ratio of the partially crosslinked polypropylene was too low and scratch resistance and hardness were poor.

In the case of Comparative Example 7 in which the weight ratio of silicon hydride / peroxide was more than 20 and the silicon hydride exceeding 0.6 part by weight was used, the melt index was low, the crosslinking ratio of the partially crosslinked polypropylene was too high and the content of silicon hydride The residual amount of silicon hydride generated gas during the extrusion appearance analysis and thus the scratch resistance measurement was impossible.

As described above, the partially crosslinked polypropylene prepared from the thermoplastic resin composite composition for partially crosslinked polypropylene of the present invention has a crosslinking ratio of 20% to 35%, and is excellent in mechanical properties such as tensile strength, hardness and impact strength The scratch resistance can be improved, and an excellent appearance can be obtained.

Claims (22)

25 to 70 parts by weight of a crystalline polypropylene resin;
15 to 45 parts by weight of a polyethylene polymer;
5 parts by weight to 25 parts by weight of ethylene-propylene rubber;
0.015 part by weight to 0.03 part by weight peroxide;
0.3 to 0.6 parts by weight of silicon hydride; And
And 3 parts by weight to 7 parts by weight of a crosslinking accelerator.
A thermoplastic resin composite composition for partially crosslinked polypropylene. The method according to claim 1,
Wherein the crystalline polypropylene resin has a melt index of 80 g / 10 min to 120 g / 10 min at a temperature of 230 캜 and a load of 2.16 kg. The method according to claim 1,
Wherein the crystalline polypropylene resin is a polypropylene homopolymer or a polypropylene copolymer; and the thermoplastic resin composite composition for partially crosslinked polypropylene. The method of claim 3,
Wherein the polypropylene copolymer comprises 7 to 15% by weight of an ethylene monomer. The method according to claim 1,
Wherein the crystalline polypropylene resin has a weight average molecular weight of 100,000 to 150,000. The method according to claim 1,
Wherein the polyethylene polymer has a melt index of 55 g / 10 min to 70 g / 10 min at a temperature of 190 캜 and a load of 2.16 kg. The method according to claim 1,
Wherein the weight average molecular weight of the polyethylene polymer is 10,000 to 100,000. The method according to claim 1,
Wherein the ethylene-propylene rubber has a melt index of from 50 g / 10 min to 70 g / 10 min at a temperature of 230 캜 and a load of 2.16 kg. The method according to claim 1,
Wherein the ethylene-propylene rubber comprises 100 parts by weight of a polypropylene matrix and 60 parts by weight to 70 parts by weight of an ethylene monomer. The method according to claim 1,
Wherein the ethylene-propylene rubber has a glass transition temperature of from -65 占 폚 to -50 占 폚. The method according to claim 1,
Wherein the peroxide has a half-life of 1 hour at a temperature of 130 캜 to 140 캜. The method according to claim 1,
Wherein the hydrogenated silicon comprises one vinyl group and one to three alkoxy groups. The method according to claim 1,
Wherein the weight ratio of silicon hydride / peroxide is from 16 to 20. The thermoplastic resin composite composition for partially crosslinked polypropylene according to claim 1, The method according to claim 1,
And 2 to 4 parts by weight of a compatibilizing agent. 15. The method of claim 14,
A thermoplastic resin composite composition for partially crosslinked polypropylene, wherein the compatibilizer is a copolymer comprising a furan-based polymer, or a monomer containing a vinyl acetal. 15. The method of claim 14,
Wherein the compatibilizing agent is maleic anhydride grafted polypropylene, and the partially crosslinked polypropylene is a thermoplastic resin composite composition. The method according to claim 1,
0.1 part by weight to 0.5 part by weight of an additive, based on the total weight of the thermoplastic resin composite composition. 18. The method of claim 17,
A thermoplastic resin composite composition for partially crosslinked polypropylene, wherein the additive is selected from the group consisting of a flame retardant, a lubricant, an antioxidant, an ultraviolet absorber, a light stabilizer, a releasing agent, a dispersant, a pigment, an antistatic agent, a metal deactivator, a coupling agent, . The method according to claim 1,
Wherein the crosslinking accelerator is an organotin compound. 20. The method of claim 19,
Wherein the organic tin compound is an octyl tin compound or a butyl tin compound, and the thermoplastic resin composite composition for partially crosslinked polypropylene. A partially crosslinked polypropylene produced by using the thermoplastic resin composite composition for partially crosslinked polypropylene according to any one of claims 1 to 20 as a raw material. 22. The method of claim 21,
A partially crosslinked polypropylene having a crosslinking ratio of 20% to 35%.

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