KR101856499B1 - Polypropylene resin composition for pressure type coolant reservoir tank - Google Patents

Abstract

The present invention relates to a resin composition comprising 50 to 95% by weight of a polypropylene resin; 1 to 5% by weight of glass fibers; 1 to 15% by weight filler; 0.01 to 1% by weight of an antioxidant; And 0.1 to 3% by weight of a nucleating agent. The polypropylene resin composition for a pressurized cooling water reservoir tank for automobiles has improved mechanical strength and heat resistance while maintaining transparency, The cooling function can be maintained at a temperature, and the low visibility of the conventional polyamide 66 can be improved, so that the user can visually confirm the water level of the cooling water.

Description

TECHNICAL FIELD [0001] The present invention relates to a polypropylene resin composition for a pressurized cooling water reservoir tank,

The present invention relates to a polypropylene resin composition for a pressurized cooling water reservoir tank having excellent mechanical strength, creep resistance, transparency and heat resistance.

Recently, as engine performance enhancement technologies such as turbo charger have been developed, there is a growing need for improvements in engine cooling technology. A pressurized engine cooling system is a type of cooling technology that is used in most engine cooling systems.

The reservoir tank for dampering the pressure of the cooling water in the engine cooling system is also switched to a pressurized type. In recent years, the temperature of the cooling water in the pressurized reservoir tank has been increased from 129 deg. C to 140 deg. . Therefore, research for improving the heat resistance of the pressurized reservoir tank has been continuously carried out.

For example, JP-A-2002-275327 discloses a propylene polymer composition containing 30 to 50 wt% of a polypropylene homopolymer and 50 to 70 wt% of a polypropylene-α-olefin random copolymer, There are weak points.

Recently, most manufacturers of pressurized reservoir tanks for automobiles have been using high-crystalline polypropylene or branched polypropylene which has higher heat distortion temperature than polypropylene or general polypropylene, which has improved crystallinity of polypropylene by using nucleating agent technology to improve heat resistance. (branched polypropylene) is used, or polyamide 66 is used to improve heat resistance at the source.

However, the heat distortion temperature of the high-crystalline polypropylene or the branched polypropylene is only about 30 ° C higher than the heat distortion temperature of 100 ° C of the general polypropylene, and the heat resistance at a temperature exceeding 130 ° C, There is a limit to use in a pressurized reservoir tank which is required.

In addition, when polyamide 66 is used, heat resistance and mechanical properties can be improved. However, since the light transmittance is lower than 35%, it is difficult for the user to visually confirm the water level of the cooling water. In addition, the polyamide 66 has a limitation in that it is disadvantageous from the economical point of view because the cost of the material is higher than that of polypropylene.

Japanese Patent Laid-Open No. 2002-275327

An object of the present invention is to provide a polypropylene resin composition capable of improving heat resistance and mechanical properties without impairing the transparency of polypropylene during injection molding of a pressurized reservoir tank. It is also intended to provide a reservoir tank having improved visibility, heat resistance and mechanical strength by using the polypropylene resin composition.

In order to achieve the above object,

50 to 95% by weight of a polypropylene resin; 1 to 5% by weight of glass fibers; 1 to 15% by weight filler; 0.01 to 1% by weight of an antioxidant; And 0.1 to 3% by weight of a nucleating agent. The present invention also provides a resin composition for a pressurized reservoir tank for automobiles.

The resin composition for a pressurized reservoir tank for automobile according to the present invention can maintain the cooling function at a temperature of 140 캜 or more by improving mechanical strength and heat resistance while maintaining transparency and improving the low visibility of conventional polyamide 66, Can be visually confirmed easily by the naked eye. In addition, by using polypropylene having a price lower than that of polyamide 66 as a main raw material, the price competitiveness of the product can be secured.

Hereinafter, the present invention will be described in detail with reference to examples. The embodiments can be modified into various forms as long as the gist of the invention is not changed.

As used herein, " comprising "means that other elements may be included unless otherwise specified.

The present invention relates to a resin composition comprising 50 to 95% by weight of a polypropylene resin; 1 to 5% by weight of glass fibers; 1 to 15% by weight filler; 0.01 to 1% by weight of an antioxidant; And 0.1 to 3% by weight of a nucleating agent. The present invention also provides a resin composition for a pressurized reservoir tank for automobiles.

The polypropylene resin is not particularly limited as long as it is used in the art and may be included in an amount of 50 to 95% by weight, or 80 to 95% by weight based on the total weight of the total resin composition, but is not limited thereto.

The polypropylene resin may have a melt index (MI) at 230 DEG C of 1.0 to 100.0 g / 10 min, or 1.0 to 10.0 g / 10 min.

When the melt index of the polypropylene resin is within the above range, it is easy to form the pressurized reservoir tank.

The glass fiber is not particularly limited as long as it is used in the art, and specifically, the glass fiber may have an average diameter of 1 to 30 탆 and the glass fiber may have an average length of 100 to 1,500 탆, but the present invention is not limited thereto .

The glass fiber may be contained in an amount of 1 to 30% by weight, specifically 1 to 20% by weight, more specifically 1 to 5% by weight, based on the total weight of the total resin composition, but is not limited thereto.

When the content of the glass fiber is in the above range, the light transmittance of the composition can be increased to 50% or more, preferably 70% or more, more preferably 80% or more, and haze is 50% or less, preferably 35% , And the visibility of the reservoir tank manufactured using the resin composition can be maintained to be excellent.

Further, the glass fiber may be coated with a silane coupling agent or a titanate coupling agent. In this case, the silane coupling agent or the titanate coupling agent may be contained in an amount of 0.1 to 1% by weight based on the total weight of the glass fibers. When the glass fiber is coated with the silane coupling agent or the titanate coupling agent in the above amount, the effect of reducing the VOC and reducing the cost can be obtained.

The filler may have a size of nano unit.

Specifically, the particle size of the filler may be between 10 and 500 nm. Specifically, the particle size of the filler may be 10 to 250 nm, more specifically 10 to 100 nm, but is not limited thereto.

The particle shape of the filler may be at least one selected from the group consisting of spherical, acicular, plate-like, fibrous, and bubble-shaped particles.

The particle size refers to a diameter of the largest area of the cross-sectional area when the particle shape of the filler is a spherical shape, an average diameter when the particle shape of the filler is an acicular shape, and a thickness when the particle shape of the filler is a plate- Means the average diameter when the particle shape of the filler is a fibrous shape, and the largest area of the cross-sectional area when the particle shape of the filler is a bubble shape.

When the particle shape of the filler is at least one selected from the group consisting of needle-shaped, plate-shaped, and fiber-shaped, the filler may have an aspect ratio of 50 to 5,000. More specifically, it may have an aspect ratio of 50 to 1,000, but is not limited thereto.

The filler may be included in an amount of 1 to 15% by weight, specifically 2 to 15% by weight, more specifically 4 to 15% by weight, based on the total weight of the total resin composition, but is not limited thereto.

Further, the fillers may comprise inorganic and / or organic fillers.

The filler may include an inorganic filler, and the inorganic filler may be at least one selected from the group consisting of clay, talc, basalt fiber, and calcium carbonate, and may be preferably clay. The inorganic filler may be a clay having a particle size of 50 nm, more specifically a plate-like clay having a thickness of 50 nm, but is not limited thereto.

The filler may include an organic filler, and the organic filler may be at least one selected from the group consisting of cellulosic and animal hair. The cellulose may be, but is not limited to, vegetable cellulosic organic fibers such as flax, hemp, jute, kenaf, abaca, bamboo, and the like . Preferably, the organic filler may be cellulose.

In addition, the filler may include an inorganic filler and an organic filler.

In addition, the inorganic filler may be included in an amount of 0.1 to 3% by weight based on the total weight of the composition, but is not limited thereto.

When the content of the filler is within the above range, mechanical properties such as tensile strength, creep resistance and impact strength can be improved.

For example, the filler may comprise an inorganic filler and an organic filler, and the inorganic filler may be a clay and the organic filler may be a cellulose, but is not limited thereto.

In addition, one embodiment may further include additives such as an antioxidant, an anti-scratch agent, a nucleating agent, a lubricant, a UV stabilizer, and the like. By further including the above additives, heat resistance and visibility of the pressurized reservoir tank can be further improved.

Specifically, the antioxidant may be at least one selected from the group consisting of a phenol type and a macromolecular type phenol amine type including a monophenol type and a bisphenol type. The antioxidant may be contained in an amount of 0.01 to 1% by weight, or 0.01 to 0.5% by weight. Within the above range, oxidation and deterioration reaction can be suppressed during processing such as extrusion of a pressurized reservoir tank, injection molding, etc., and occurrence of defects can be reduced.

In addition, the antioxidant may further include a peroxide decomposer. Specifically, the antioxidant may further include peroxide dissolution in an amount of 0.01 to 1.0% by weight, or 0.1 to 0.5% by weight based on the total weight of the composition. Further, the peroxide decomposer may be dilauryl thiodipropionate or distearyl thiodipropionate. Within the above range, it is possible to improve the heat resistance and maintain the appearance quality of the pressurized reservoir tank more excellent.

The nucleating agent may be, for example, sorbitol-based, and specifically may be benzylidene sorbitol, methylbenzylidene sorbitol, ethylbenzylidene sorbitol, and di (p-methylbenzylidene) sorbitol. The nucleating agent may be contained in an amount of 0.1 to 10% by weight, or 0.1 to 3% by weight. Within the above range, the crystallization rate of the polypropylene resin in the composition can be increased without impairing the transparency of the polypropylene resin composition.

The polypropylene resin composition may be injection-molded by a series of manufacturing processes of a pressurized reservoir tank commonly used in the art, and may include injection molding, extrusion molding, and the like, but is not limited thereto .

INDUSTRIAL APPLICABILITY As described above, the polypropylene resin composition for a pressurized cooling water reservoir tank for automobile according to the present invention has mechanical properties such as tensile strength, tensile elasticity, flexural strength, flexural modulus, impact strength, The strength can be improved. In addition, the heat resistance can be improved, the cooling function can be maintained at a temperature of 140 ° C or higher, and the low visibility of the conventional polyamide 66 can be improved, so that the user can visually confirm the water level of the cooling water. In addition, by using polypropylene having a price lower than that of polyamide 66 as a main raw material, the price competitiveness of the product can be secured.

The above contents will be described in more detail by the following examples. However, the following examples are for illustrative purposes only and are not intended to limit the scope of the examples.

[ Example ]

Example  1 to 3 and Comparative Example  1 to 4 of  Produce

The resin composition for a pressurized reservoir tank for automobiles according to Examples 1 to 3 and Comparative Examples 1 to 4 was prepared by mixing the constituents and the contents shown in Table 1 below.

Constituent
(Unit: g) Example Comparative Example One 2 3 One 2 3 4 Polypropylene 88.6 84.6 77.6 76.6 82.6 92.6 76.6 Glass fiber 5.0 5.0 5.0 6.0 0.0 5.0 5.0 Nano clay 3.0 3.0 3.0 3.0 3.0 0.0 4.0 Nano-cellulose 1.0 5.0 12.0 12.0 12.0 0.0 12.0 Phenolic antioxidant 0.3 0.3 0.3 0.3 0.3 0.3 0.3 Release of peroxide 0.1 0.1 0.1 0.1 0.1 0.1 0.1 Nucleating agent 2.0 2.0 2.0 2.0 2.0 2.0 2.0

Evaluation example  1: Specific gravity

The specific gravity of the resin compositions prepared in Examples 1 to 3 and Comparative Examples 1 to 4 was measured at room temperature according to the ASTM D-1238 method. The results are shown in Table 2 below.

Evaluation example  2: tensile strength

The specimens prepared from the resin compositions prepared in Examples 1 to 3 and Comparative Examples 1 to 4 were measured using a universal testing machine (UTM) according to the ASTM D-638 method. The cross- The head speed was set at 50 mm / min, and the gauge length was set at 50 mm. The results are shown in Table 2 below.

Evaluation example  3: Elongation

The specimens prepared from the resin compositions prepared in Examples 1 to 3 and Comparative Examples 1 to 4 were measured using a universal testing machine (UTM) according to the ASTM D-638 method. The cross- The head speed was set at 50 mm / min, and the gauge length was set at 50 mm. The results are shown in Table 2 below.

Evaluation example  4: Flexural strength

The specimens prepared from the resin compositions prepared in Examples 1 to 3 and Comparative Examples 1 to 4 were measured using a universal testing machine (UTM) according to the ASTM D-790 method. The cross- The head speed was set at 10 mm / min, and the gauge length was set at 10 mm. The results are shown in Table 2 below.

Evaluation example  5: Flexural modulus

The specimens prepared from the resin compositions prepared in Examples 1 to 3 and Comparative Examples 1 to 4 were measured using a universal testing machine (UTM) according to the ASTM D-790 method. The cross- The head speed was set at 10 mm / min, and the gauge length was set at 10 mm. The results are shown in Table 2 below.

Evaluation example  6: IZOD  Impact strength

The Izod impact strengths of the specimens prepared from the resin compositions prepared in Examples 1 to 3 and Comparative Examples 1 to 4 were measured at room temperature using the notched specimen pieces according to the ASTM D-256 method, Respectively.

Evaluation example  7: Heat distortion temperature

Based on the ASTM D-648 method, the resin compositions prepared in Examples 1 to 3 and Comparative Examples 1 to 4 were subjected to a load of 18.6 kgf / cm ² and the peripheral fluid temperature was increased at a rate of 2 ° C / min The temperature at which the deformation of the specimen reached 0.254 mm was measured, and the results are shown in Table 2 below

Evaluation example  8 : Light transmittance

The resin compositions prepared in Examples 1 to 3 and Comparative Examples 1 to 4 were measured for light transmittance in a wavelength range of 200 to 900 nm on the basis of a 3 mm sheet according to the ASTM D-1003 method, and five values excluding the maximum value and the minimum value And the haze was obtained. The results are shown in Table 2 below.

Evaluation example  9: Hayes

The resin compositions prepared in Examples 1 to 3 and Comparative Examples 1 to 4 were cut into a size of 5 cm × 5 cm by the method of ASTM D-1003, put in a haze measuring device, and light having a wavelength of 555 nm was transmitted to measure haze (%) The haze values were obtained by taking an average value of the five values excluding the maximum value and the minimum value, and the results are shown in Table 2 below.

Test Items Example Comparative Example One 2 3 One 2 3 4 Specific Gravity (g / ml) 0.98 0.98 0.98 0.99 0.95 0.96 0.99 Tensile Strength (MPa) 67 72 78 85 60 62 81 Elongation (%) 10 12 15 18 7 9 17 Flexural Strength (MPa) 81 94 102 115 72 78 108 Flexural modulus (MPa) 2850 3280 3590 3750 2250 2750 3610 IZOD impact strength (J / m) 48 55 62 70 32 42 62 Heat deformation temperature (캜) 137 142 151 155 127 130 153 Light transmittance (%) 87 83 80 76 91 88 77 Haze (%) 28 32 35 45 22 26 43

As can be seen from the above Table 2, Examples 1 to 3 are superior in mechanical properties such as tensile strength, elongation, flexural strength, flexural modulus, IZOD impact strength and thermal deformation temperature as compared with Comparative Examples 1 to 4, It was confirmed that the transmittance was high and the haze was low and the visibility was also secured.

Claims (11)

50 to 95% by weight of a polypropylene resin;
1 to 5% by weight of glass fibers;
0.1 to 3% by weight of nanoclay;
1 to 12% by weight of nanocellulose;
0.01 to 1% by weight of an antioxidant; And
0.1 to 3% by weight of a nucleating agent,
The thickness of the nanoclay is 10 to 100 nm,
The average diameter of the nanocellulose is 10 to 100 nm,
Wherein the aspect ratio of the nano-clay and the nano-cellulose is 50 to 1,000. The method according to claim 1,
Wherein the glass fiber is coated with a silane coupling agent or a titanate coupling agent. 3. The method of claim 2,
Wherein the silane coupling agent or the titanate coupling agent is contained in an amount of 0.1 to 1% by weight based on the total weight of the glass fiber. delete delete delete delete delete The method according to claim 1,
Wherein the antioxidant is selected from the group consisting of phenol-based ones including monophenolic and bisphenol-based antioxidants; And a high molecular weight phenol amine type resin. 10. The method of claim 9,
The resin composition for a pressurized reservoir tank for automobile according to claim 1, wherein the antioxidant further comprises a peroxide decomposer. 11. The method of claim 10,
Wherein the peroxide decomposing agent is dilauryl thiodipropionate or distearyl thiodipropionate. 2. The resin composition for a pressurized reservoir tank for automobile according to claim 1, wherein the peroxide decomposing agent is dilauryl thiodipropionate or distearyl thiodipropionate.