WO2023096046A1 - Polypropylene resin composition, method for producing same, and molded products comprising same - Google Patents

Abstract

The present specification relates to a polypropylene resin composition, a method for producing same, and molded products comprising same, the polypropylene resin composition comprising: ultra-high molecular weight polypropylene resin having weight-average molecular weight of 1,000,000 g/mol or greater; glass fibers; a reactive compatibilization agent; and maleic anhydride.

Description

Polypropylene resin composition, manufacturing method thereof, and molded article containing the same

The present specification relates to a polypropylene resin composition, a method for preparing the same, and a molded article including the same.

Polypropylene resin has excellent formability, impact resistance, chemical resistance, etc., and has great advantages such as low specific gravity and low price, so it is used in automotive interior and exterior materials such as bumpers, cowl crossbars, door inner panels and interior trims that require both safety and functionality. is widely used in

In particular, the material used for automobile cowl cross members requires excellent impact strength at room and low temperatures, high heat resistance, and high rigidity. It has been used by adding a filler of a certain amount or more.

In addition, since homopolymerized homopolypropylene has low impact strength, a technique for supplementing impact strength by copolymerizing with alpha olefin, for example, ethylene, is used during polymerization. These ethylene-propylene block copolymers are widely used in injection molded products and sheets such as automobile parts, home appliances, and daily necessities due to their excellent stiffness and impact properties.

However, the ethylene-propylene block copolymer has a disadvantage in that it has poor kneadability with the rigid ethylene-propylene copolymer. Although there are various methods for improving these disadvantages, a polypropylene resin composition showing a satisfactory improvement in impact strength has not been provided so far.

In general, polypropylene resin for extrusion and injection refers to a homogeneous material with a size of about 2 to 3 mm. It is a material that has been hybridized by a chemical method.

The pellets are completely melted under constant temperature and pressure, and are ejected by the screw force and come out through the nozzle. However, the particles of polypropylene resin having an average diameter of 0.1 to 200 um are small and do not have a pellet shape, so that the melt does not enter a viscous flow state and is maintained in a rubber-like state at a temperature higher than the melting temperature in the cylinder. It is in the form of a block, and the flow rate through the nozzle decreases, the pressure in the cylinder rises, and the thermal stress received by the resin is added, causing the polymer linkage to break and the physical properties of the resin to be lost. Polypropylene resin with such a high molecular weight has high physical and mechanical strength, so if processed while making good use of the original characteristics of the resin, polypropylene with excellent physical properties can be used as a base material to be used in composite materials.

The present invention satisfies the impact characteristics without using a rubber-type impact resistant agent based on ultra-high molecular weight polypropylene of 1,000,000 or more. In addition, by using a rigidity supplementing ability and homopolypropylene, the reduction in rigidity is reduced by not using an impact resistant agent. It is intended to provide a resin composition having high impact properties.

[Prior art literature]

[Patent Literature]

KR 10-1131634

KR 10-1131361

The present specification relates to a polypropylene resin composition, a method for preparing the same, and a molded article including the same.

An exemplary embodiment of the present invention is an ultra-high molecular weight polypropylene resin having a weight average molecular weight of 1 million g / mol or more; glass fiber; reactive compatibilizers; And it provides a polypropylene resin composition containing an acid anhydride.

Another embodiment of the present invention is an ultra-high molecular weight polypropylene resin having a weight average molecular weight of 1 million g / mol or more; glass fiber; reactive compatibilizers; And it provides a method for producing the above-described polypropylene resin composition comprising the step of mixing the acid anhydride.

Another embodiment of the present invention provides a molded article comprising the polypropylene resin composition described above.

The polypropylene resin composition according to an exemplary embodiment of the present invention has an effect capable of maintaining excellent physical properties of the ultra-high molecular weight polypropylene resin.

1 shows pellets prepared using the ultra-high molecular weight polypropylene resin of Example 1 and a composition containing the same.

2 to 4 are scanning electron microscope (SEM) photographs of pellets prepared using the composition of Example 1.

5 shows a cowl cross bar for automobile exterior molded using the composition of Example 1.

Hereinafter, this specification will be described in more detail.

An exemplary embodiment of the present invention is an ultra-high molecular weight polypropylene resin having a weight average molecular weight of 1 million g / mol or more; glass fiber; reactive compatibilizers; And it provides a polypropylene resin composition containing an acid anhydride.

In general, ultra-high molecular weight polypropylene resins having a weight average molecular weight of 1 million g/mol or more are known to have excellent physical properties, but poor flowability and poor manufacturing processability. In particular, there was a problem in the process that the resins had to go through a separate grinding process before being introduced into the extruder due to the phenomenon of aggregation with each other. Specifically, when the resin was taken out after mixing the resin, the resin was cooled and the resin hardened, and a milling process was required to grind the hardened resin. In this case, the physical properties of the resin were damaged during the cooling and grinding process. Or a deterioration problem occurred. Although technology for incorporating additives to improve flowability has been developed, it has emerged as a problem of lowering the inherent physical properties of ultra-high molecular weight polypropylene resin.

The present inventors have developed a polypropylene resin composition with improved flowability and improved processability without deteriorating the physical properties of the ultrahigh molecular weight polypropylene resin.

In one embodiment of the present invention, the polypropylene resin composition includes glass fibers, thereby maintaining the light weight of the ultra-high molecular weight polypropylene resin, and greatly improving mechanical strength. Specifically, the glass fiber may be combined with a polypropylene resin to greatly improve the mechanical strength of the resin.

In one embodiment of the present invention, the polypropylene resin composition may improve wettability and impregnability of the composition and improve mechanical strength by including a reactive compatibilizer. Specifically, the purpose intended by the present invention can be achieved by making the glass fiber well combined with the polypropylene resin.

In one embodiment of the present invention, the average particle diameter of the glass fibers is 5 μm to 1,000 μm, 5 μm to 15 μm, 7 μm to 14 μm, 8 μm to 13 μm, 8 μm to 12 μm, or 9 μm to It may be 11 μm. The method of measuring the average particle diameter of the glass fiber is to measure the particle diameter of the glass fiber in the specimen by SEM by taking a section of the specimen at -30 ° C. Within the above numerical range, the flowability of the polypropylene resin composition containing glass fibers is not hindered, and mechanical strength can be effectively improved.

In one embodiment of the present invention, the average length of the glass fibers may be 50 μm to 30,000 μm or less. Specifically, it may be 80 μm to 5,000 μm, 100 μm to 4,800 μm, 150 μm to 4,600 μm, 4,000 μm to 4,400 μm, 4,000 μm to 4,200 μm. Within the above numerical range, the flowability of the polypropylene resin composition containing glass fibers is not hindered, and mechanical strength can be effectively improved.

In one embodiment of the present invention, the particle diameter and length of the glass fiber can be confirmed through a scanning battery microscope (SEM).

In one embodiment of the present invention, the content of the glass fiber may be 30 parts by weight to 200 parts by weight, 50 parts by weight to 180 parts by weight, or 100 parts by weight to 150 parts by weight based on 100 parts by weight of the ultra-high molecular weight polypropylene resin. there is. Within the above numerical range, the flowability of the polypropylene resin composition containing glass fibers is not hindered, and mechanical strength can be effectively improved.

In one embodiment of the present invention, the glass fiber may be E glass fiber, C glass fiber, A glass fiber, H glass fiber, G glass fiber or S glass fiber. In addition, glass fibers may use two or more of the above types in combination.

In one embodiment of the present invention, the glass fibers may be E glass fibers or H glass fibers.

In one embodiment of the present invention, the reactive compatibilizer; And the content of the acid anhydride is the same as or different from each other, and may be 0.1 part by weight to 20 parts by weight based on 100 parts by weight of the ultra-high molecular weight polypropylene resin. In addition, it may be 0.1 part by weight to 15 parts by weight or 0.1 part by weight to 10 parts by weight. In the above numerical range, wettability and impregnation effect by the reactive compatibilizer or acid anhydride may be increased.

In one embodiment of the present invention, the polypropylene resin composition may include a neutralizing agent.

In one embodiment of the present invention, the content of the neutralizing agent may be 0.1 part by weight to 20 parts by weight based on 100 parts by weight of the ultra-high molecular weight polypropylene resin. In addition, it may be 0.1 part by weight to 15 parts by weight or 0.1 part by weight to 10 parts by weight.

In one embodiment of the present invention, the neutralizing agent may be synthetic hydrotalcite.

In one embodiment of the present invention, the polypropylene resin composition may further include additives such as pigments, dyes, carbon black, antioxidants, or catalysts.

In one embodiment of the present invention, the reactive compatibilizer is 2- (3,4 epoxycyclohexyl) ethyltrimethoxysilane [2- (3,4 epoxycyclohexyl) ethyltrimethoxysilane, 3-glycitoxypropyl methyldimethoxy Silane [3-glycidoxypropyl methyldimethoxysilane], 3-glycidoxypropyl trimethoxysilane [3-glycidoxypropyl trimethoxysilane], 3-glycidoxypropyl triethoxysilane [3-glycidoxypropyl triethoxysilane], [N-2-(aminoethyl )-3-aminopropylmethyldimethoxysilane [N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane], N-2-(aminoethyl)-3-aminopropyltrimethoxysilane [N-2-(aminoethyl)-3 -aminopropyltrimethoxysilane], 3-aminopropyltrimethoxysilane [3-aminopropyltrimethoxysilane], 3-aminopropyltriethoxysilane [3-aminopropyltriethoxysilane], 3-triethoxysilyl-N-(1,3 dimethyl-butylidene )Propylamine [3-triethoxysilyl-N-(1,3 dimethyl-butylidene)propylamine], N-phenyl-3-aminopropyltrimethoxysilane [N-phenyl-3-aminopropyltrimethoxysilane], N-(vinylbenzyl)- 2-aminoethyl)-3-aminopropyltrimethoxysilane hydrochloride [N-(vinylbenzyl)-2-aminoethyl-3-aminopropyltrimethoxysilane hydrochloride], N-(vinylbenzyl)-2-aminoethyl-3-aminopropyltri At least one selected from the group consisting of methoxysilane hydrochloride [N-(vinylbenzyl)-2-aminoethyl-3-aminopropyltrimethoxysilane hydrochloride] and combinations thereof may be included.

In one embodiment of the present invention, the flow index measured under a temperature of 230 ° C. and a load of 21.6 kg may be 1 g / 10 min or more. Specifically, it may be 1 g/10 min to 50 g/10 min, 1 g/10 min to 10 g/10 min, 1 g/10 min to 5 g/10 min, or 1 g/10 min to 3 g/10 min. Within the range of the above values, it is possible to obtain a molded article having excellent fluidity of the composition, excellent appearance, and excellent strength.

Another embodiment of the present invention is an ultra-high molecular weight polypropylene resin having a weight average molecular weight of 1 million g / mol or more; glass fiber; reactive compatibilizers; And it provides a method for producing the above-described polypropylene resin composition comprising the step of mixing the acid anhydride.

In one embodiment of the present invention, the glass fiber may be supplied in the form of a glass fiber bundle. The number of focused glass fibers may be 900 to 1,500, more preferably 900 to 1,100. Within the above numerical range, the dispersibility and processability of glass fibers can be improved.

In one embodiment of the present invention, the polypropylene resin; glass fiber; reactive compatibilizers; Alternatively, an electric feeder or a popper may be used to supply the acid anhydride.

In one embodiment of the present invention, a kneading step of kneading the mixture; and an extrusion step of extruding the mixture.

In one embodiment of the present invention, the kneading step; Alternatively, the extrusion step may use a melt-kneading extruder and may include two or more raw material supply ports. At this time, the polypropylene resin; glass fiber; reactive compatibilizers; Alternatively, the acid anhydride may be supplied from the same or different supply ports.

In one embodiment of the present invention, the kneading step may be performed at a temperature of 180 ° C. or higher and a speed of 200 rpm or higher. The temperature may be 180 °C to 200 °C, and the speed may be 200 rpm to 300 rpm or 200 rpm to 250 rpm. The temperature means the temperature inside the extruder where the kneading step is performed, and the speed means the number of revolutions per minute (rpm) of the extruder screw. In the above temperature range, since the melting point (Tm) of the ultra-high molecular weight polypropylene resin is maintained at a temperature of about 170 ° C. or higher for a sufficient residence time in the extruder, the polypropylene resin can be sufficiently melted.

Another embodiment of the present invention provides a molded article comprising the polypropylene resin composition described above. The fields of application of the molded product include, for example, automobile parts including cowl cross members and door inner panels, electric and electronic parts requiring low specific gravity and high impact resistance, such as switches and valves, automobile parts, and precision machine parts. Not limited to this.

In one embodiment of the present invention, the tensile strength of the molded article measured according to ASTM D638 may be 140 MPa or more.

In one embodiment of the present invention, the impact strength of the molded product measured according to the ASTM D256 standard may be 30 kJ/m 2 or more.

In one embodiment of the present invention, the heat deflection temperature (HDT) of the molded product measured according to the ASTM D648 standard may be 160° C. or higher.

Hereinafter, the present invention will be described through examples. However, the scope of the present invention is not limited to the scope of the following examples, and is introduced to explain the present invention in more detail.

Example 1

100 parts by weight of ultra-high molecular weight polypropylene resin with a molecular weight of 2 million g / mol, 120 parts by weight of H-Glass glass fiber with an average diameter of 10 μm in white color, 0.5 parts by weight of 3-glycidoxypropyltrimethoxysilane as a reactive compatibilizer A polypropylene resin composition was prepared by introducing 0.3 parts by weight of maleic anhydride and 0.8 parts by weight of synthetic hydrotalcite as a neutralizing agent into a twin screw extruder and performing a series of melting and kneading processes. At this time, the melting temperature was 180 ° C. and the kneading speed was 300 rpm.

In addition, a photograph of an ultra-high molecular weight polypropylene resin (left side of FIG. 1) and a pellet prepared using the prepared polypropylene resin composition before preparation (right side of FIG. 1) are shown.

In addition, it was confirmed through a scanning electron microscope (SEM) that the glass fibers were well impregnated into the ultra-high molecular weight polypropylene (FIG. 2). In addition, the particle diameter (FIG. 4) and length (FIG. 3) of the glass fibers are shown.

Meanwhile, a cowl cross bar for automobile exterior was molded using the prepared polypropylene resin composition, and is shown in FIG. 5 .

<Examples 2 to 4>

A polypropylene resin composition was prepared in the same manner as in Example 1 except for changing the composition in Table 1 below.

<Comparative Examples 1 and 2>

A polypropylene resin composition was prepared in the same manner as in Example 1 except for changing the composition in Table 1 below.

division		Example	comparative example
		One	One	2	3
profit	Ultra High Molecular Weight Polypropylene	100	100	100	100
enhancer	fiberglass	120	0	120	120
additive	reactive compatibilizer (3-glycidoxypropyltrimethoxysilane	0.5	0.5	0	0.5
	acid anhydride (Maleic anhydride)	0.3	0.3	0.3	0
	Neutralizing agents (synthetic hydrotalcite, synthetic hydrotalcite)	0.8	0.8	0.8	0.8

<Experiment method>

According to the measurement method below, the physical properties of each propylene resin composition were tested.

1) Specific Gravity: ASTM D792

2) Tensile strength: ASTM D638 (measuring the maximum strength until the specimen breaks)

3) Elongation: ASTM D638 (measuring the ductility of the specimen until fracture)

4) Flexural strength: ASTM D790 (measurement of maximum strength generated from specimens)

5) Flexural modulus: ASTM D790 (measurement of the ratio of the applied stress to the strain in the region where the stress and strain applied to the specimen are linearly proportional to the stress)

6) Impact strength: ASTM D256 (Notched)

7) Heat deflection temperature (HDT): ASTM D648 (1.82MPa)

8) Molecular weight measurement method

- Gel chromatography (GEL PERMEATION CHROMATOGRAPHY) method was used, and the GPC analysis instrument conditions are as follows.

- Developing solvent: TCB + 0.04% BHT (after drying with 0.1% CaCl2)

- Column: PLgel guard (7.5 x 50mm) + 2*PLgel mixed-B

- Column temperature: 160 ℃

- Detector: RI-detector

- Standard: Polystyrene

<Experimental Example 1>

Properties	unit	Example 1	Comparative Example 1	Comparative Example 2	Comparative Example 3
importance	-	1.37	1.37	1.37	1.37
tensile strength	MPa	142	45	135	78
flexural strength	MPa	186	48	175	120
flexural modulus	MPa	9,870	1,703	9,187	3,185
impact strength	kJ/m 2	33	18	30	19
Heat deflection temperature (HDT)	℃	161	100	161	102

From the above results, as the polypropylene resin composition of Example includes glass fibers, tensile strength and flexural strength were excellent. On the other hand, it was confirmed that the polypropylene resin composition of Comparative Example 1, which did not contain glass fibers, had significantly inferior physical properties. On the other hand, it was confirmed that the polypropylene resin composition of Comparative Example 2, which did not contain a reactive compatibilizer, and the polypropylene resin composition of Comparative Example 3, which did not contain an acid anhydride, also showed decreases in tensile strength, flexural strength and flexural modulus.

From the above results, it was confirmed that physical properties can be improved when glass fibers and a reactive compatibilizer are included in an ultra-high molecular weight polypropylene resin having a weight average molecular weight of 1,000,000 g/mol or more.

<Experimental Example 2>

Properties	unit	melt extrusion temperature
		180	190	200	210	220	230
importance	-	1.37	1.37	1.37	1.37	1.37	1.37
tensile strength	MPa	141	142	142	142	142	134.5
elongation	%	2.9	3	2.9	2.9	2.9	1.9
flexural modulus	MPa	9,912	9,924	9,974	9,936	9,904	8,983
impact strength	kJ/m 2	34	33	34	32	33	24

From the above results, it was confirmed that when the melt extrusion temperature is at a high temperature of 220° C. or more, the polymer chain of the polypropylene resin is destroyed and mechanical properties are deteriorated. Specifically, when the melt-extrusion temperature was 220 ° C or higher, it was confirmed that the tensile strength, elongation and flexural modulus of the polypropylene resin were lowered, and in particular, it was confirmed that the impact strength was significantly reduced at 230 ° C.

Claims (15)

1. ultra-high molecular weight polypropylene resin having a weight average molecular weight of 1,000,000 g/mol or more;

   glass fiber;

   reactive compatibilizers; and

   A polypropylene resin composition comprising an acid anhydride.
2. The method of claim 1,

   The polypropylene resin composition of which the average particle diameter of the glass fibers is 5 μm to 1,000 μm.
3. The method of claim 1,

   The polypropylene resin composition of which the average length of the glass fibers is 50 μm to 30,000 μm.
4. The method of claim 1,

   A polypropylene resin composition in which the content of the glass fiber is 30 parts by weight to 200 parts by weight based on 100 parts by weight of the ultra-high molecular weight polypropylene resin.
5. The method of claim 1,

   The glass fiber is a polypropylene resin composition of E glass fiber or H glass fiber.
6. The method of claim 1,

   the reactive compatibilizer; and the content of the acid anhydride is the same as or different from each other, and is 0.1 part by weight to 20 parts by weight based on 100 parts by weight of the ultra-high molecular weight polypropylene resin.
7. The method of claim 1,

   The reactive compatibilizer is 2-(3,4 epoxycyclohexyl) ethyltrimethoxysilane [2-(3,4 epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropyl methyldimethoxysilane [3-glycidoxypropyl methyldimethoxysilane], 3 -Glycidoxypropyl trimethoxysilane [3-glycidoxypropyl trimethoxysilane], 3-glycidoxypropyl triethoxysilane [3-glycidoxypropyl triethoxysilane], [N-2-(aminoethyl)-3-aminopropylmethyldimethoxy Silane N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane], N-2-(aminoethyl)-3-aminopropyltrimethoxysilane [N-2-(aminoethyl)-3-aminopropyltrimethoxysilane], 3-aminopropyltrimethoxysilane Methoxysilane [3-aminopropyltrimethoxysilane], 3-aminopropyltriethoxysilane [3-aminopropyltriethoxysilane], 3-triethoxysilyl-N-(1,3 dimethyl-butylidene)propylamine [3-triethoxysilyl-N -(1,3 dimethyl-butylidene)propylamine], N-phenyl-3-aminopropyltrimethoxysilane [N-phenyl-3-aminopropyltrimethoxysilane], N-(vinylbenzyl)-2-aminoethyl)-3-amino Propyltrimethoxysilane hydrochloride [N-(vinylbenzyl)-2-aminoethyl-3-aminopropyltrimethoxysilane hydrochloride], N-(vinylbenzyl)-2-aminoethyl-3-aminopropyltrimethoxysilane hydrochloride [N-( vinylbenzyl) -2-aminoethyl-3-aminopropyltrimethoxysilane hydrochloride] and a polypropylene resin composition comprising at least one selected from the group consisting of combinations thereof.
8. The method of claim 1,

   A polypropylene resin composition having a flow index of 1 g / 10 min or more measured at a temperature of 230 ° C. under a load of 21.6 kg.
9. ultra-high molecular weight polypropylene resin having a weight average molecular weight of 1,000,000 g/mol or more; glass fiber; reactive compatibilizers; And a method for producing a polypropylene resin composition according to any one of claims 1 to 8 comprising mixing an acid anhydride.
10. The method of claim 9,

    A kneading step of kneading the mixture; and

    Method for producing a polypropylene resin composition comprising an extrusion step of extruding the mixture.
11. The method of claim 10,

    The kneading step is a method for producing a polypropylene resin composition that is performed at a temperature of 180 ° C. or higher and a speed of 200 rpm or higher.
12. A molded article comprising the polypropylene resin composition according to any one of claims 1 to 8.
13. The method of claim 12,

    A molded article having a tensile strength of 140 MPa or more measured according to ASTM D638.
14. The method of claim 12,

    A molded article having an impact strength of 30 kJ/m 2 or more measured according to ASTM D256 standard.
15. The method of claim 12,

    A molded article having a heat deflection temperature (HDT) of 160 ° C. or more measured according to ASTM D648 standard.

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