KR20240003519A - Polypropylene resin composition comprising peroxide and polypropylene molded product using the same - Google Patents

Abstract

The polypropylene resin composition containing peroxide of the present invention includes cellulose fibers; peroxide; maleic anhydride polypropylene; peroxide; and impact polypropylene having a melt index of 20.1 to 40 g/10 min, wherein the cellulose fibers are surface modified with alkenyl succinic anhydride to exhibit high compatibility with polypropylene and can exhibit excellent rigidity, impact resistance, and heat resistance. .

Description

Polypropylene resin composition comprising peroxide and molded product using the same {Polypropylene resin composition comprising peroxide and polypropylene molded product using the same}

The present invention relates to a polypropylene resin composition containing peroxide and a molded article using the same.

The mechanical properties of polypropylene (PP) products are closely related to the application of polypropylene products. In particular, among the mechanical properties of polypropylene products, rigidity and impact strength are of great importance. Among mechanical properties, rigidity is a type of physical property represented by Flexural Modulus. Products with high rigidity can be applied to automobile parts and general injection products, so the need for polypropylene products with high rigidity is increasing. there is.

In addition, in the case of products with guaranteed eco-friendliness, which is one of the recent plastic product trends, the field of application is expanding. In the case of the development of eco-friendly plastics, the main products were products that mixed various biomass with petroleum-based plastics, and eco-friendly plastics using modern carbon starting from plastic monomers.

However, in the case of the two types of eco-friendly plastics, the problem has been that their physical properties are inferior to those of existing petroleum-based plastics. In the case of eco-friendly plastics mixed with bio-mass and petroleum-based plastics, most bio-mass exhibits plant-derived hydrophilic properties, making mixing difficult, making development of the corresponding product group difficult. In addition, in the case of eco-friendly plastics (EX PLA, PHA, etc.) using modern carbon, there is a problem with the high production cost of the products. Therefore, there is a need to develop eco-friendly plastics that are low in cost and have physical properties equal to or better than those of existing petroleum-based plastics.

Patent Document 1. Korean Patent Publication No. 10-2019-0069223

The present invention was made to solve the problems described above, and the object of the present invention is to provide cellulose fiber, maleic anhydride polypropylene, peroxide, and impact polypropylene that satisfies a specific range of melt index, and the cellulose fiber provides an eco-friendly polypropylene resin composition with excellent mechanical properties and heat resistance by surface modification with alkenyl succinic anhydride to improve compatibility and dispersibility between polypropylenes.

One aspect of the present invention is (a) cellulose fiber (CMF) surface-modified with alkenyl succinic anhydride (ASA); (b) Maleic Anhydride Polypropylene (MaPP); (c) Peroxide; and (d) impact polypropylene, wherein the impact polypropylene has a melt index of 20.1 to 40 g/10 min.

Another aspect of the present invention provides a polypropylene molded article manufactured using the polypropylene resin composition.

The polypropylene resin composition of the present invention includes cellulose fibers; maleic anhydride polypropylene; peroxide; and impact polypropylene having a melt index of 20.1 to 40 g/10 min, wherein the cellulose fiber is surface-modified with alkenyl succinic anhydride to exhibit high compatibility with polypropylene and can exhibit excellent rigidity and heat resistance.

Figure 1 shows a photographic image of polypropylene resin prepared in an example of the present invention.
Figure 2 shows a scanning electron microscope (SEM) image of the polypropylene resin prepared in (a) Comparative Example 3, (b) Example 1, and (c) Example 2 of the present invention.

Hereinafter, the present invention will be described in more detail with the accompanying drawings and examples.

As previously explained, in the case of bio-mass and petroleum-based eco-friendly composite plastics, most plant-derived biomass is hydrophilic, making it difficult to mix with hydrophobic plastic resins, resulting in physical properties equal to or better than those of petroleum-based plastics alone. It was difficult to secure, and there was a problem of high production costs.

Accordingly, the present invention includes cellulose fibers, maleic anhydride polypropylene, peroxide, and impact polypropylene with a melt index of 20.1 to 40 g/10 min, and surface-modifies the cellulose fibers with alkenyl succinic anhydride to form a conventional petroleum-based polypropylene. A polypropylene resin composition is provided that has mechanical properties equivalent to those of propylene resin and exhibits excellent rigidity and heat resistance.

More specifically, one aspect of the present invention is (a) cellulose fiber (CMF) surface-modified with alkenyl succinic anhydride (ASA); (b) Maleic Anhydride Polypropylene (MaPP); It provides a polypropylene resin composition comprising (c) peroxide and (d) impact polypropylene, wherein the impact polypropylene has a melt index of 20.1 to 40 g/10 min.

The polypropylene resin composition of the present invention is characterized in that it includes cellulose fibers surface-modified with alkenyl succinic anhydride, maleic anhydride polypropylene, peroxide, and impact polypropylene with a melt index of 20.1 to 40 g/10 min. The mechanical strength, physical properties, and heat resistance of the composition were significantly improved. If any one of the above components is not included, the cellulose fiber is surface modified with a compound other than alkenyl succinic anhydride, or the melt index of the impact polypropylene is outside the above range, the compatibility between the components is significantly reduced and each component The elements may not be mixed uniformly and may partially cohere, or the impact resistance may deteriorate and cracks may occur due to repeated impacts.

The cellulose fiber is characterized by surface modification with alkenyl succinic anhydride (ASA). While cellulose fibers are hydrophilic, impact polypropylene is hydrophobic, so the two materials have poor compatibility, making it difficult to uniformly disperse the cellulose fibers when mixed. Accordingly, in the present invention, the cellulose fiber was surface modified with alkenyl succinic anhydride to improve compatibility with impact polypropylene, thereby improving dispersion and physical properties.

The size of the cellulose fiber may be 10 to 250 ㎛. In the present invention, the size of cellulose fiber means the average length of the cellulose fiber. If the size of the cellulose fiber is less than the above lower limit, the cost may increase due to a decrease in manufacturing yield and an increase in process cost, and the physical properties of the polypropylene resin composition may deteriorate. Conversely, if the size of the cellulose fiber exceeds the above upper limit, it is not easy to enter the process and agglomeration may occur, which may reduce dispersibility and compatibility.

The cellulose fibers may be included in an amount of 20 to 45 wt%, preferably 35 to 40 wt%, based on 100 wt% of the total polypropylene composition. If the content of cellulose fiber is less than the above lower limit, the standards for bio-based PP among eco-friendly plastics cannot be met, and the effect of improving the physical properties of the polypropylene resin composition may be reduced. Conversely, if the above upper limit is exceeded, it is not easy to enter the process and extrusion processing may be difficult.

Maleic anhydride polypropylene is a polypropylene containing both hydrophobic and hydrophilic functional groups, and can improve compatibility between cellulose fibers and impact polypropylene and improve the physical properties of the polypropylene resin composition.

The maleic anhydride polypropylene may be included in an amount of 1 to 4 wt% based on 100 wt% of the total polypropylene resin composition. If the content of maleic anhydride polypropylene is less than the above lower limit, the dispersion of the cellulose fibers may be lowered and the physical properties of the polypropylene resin composition produced may be reduced. Conversely, if the content of maleic anhydride polypropylene is greater than the above upper limit, maleic anhydride polypropylene may have lower physical properties compared to impact polypropylene. As the content increases, the physical properties (particularly, flexural strength) of the polypropylene resin composition may decrease and the cost may increase.

Peroxide can cause radicalization of the polypropylene resin, thereby inducing a chemical reaction between the components of the polypropylene resin composition. Through this, a chemical bond is formed between the cellulose fibers and the impact polypropylene, thereby improving the dispersion of the cellulose fibers in the polypropylene resin composition and the physical properties of the resin composition.

The peroxides include 2.5-dimethyl-2.5-di-thi-butyl peroxyhexane, diisobutyl peroxide, t-amylperoxyneodicarbonate, di(4-t-butylcyclohexyl) peroxydicarbonate, and diethylhexyl. peroxydicarbonate, dibutyl peroxydicarbonate, diisopropyl peroxydicarbonate, dicetyl peroxydicarbonate, dimyristyl peroxydicarbonate), isobutyl peroxide, lauronyl peroxide, benzoyl peroxide, m-toluoyl Peroxide (m-toluoyl peroxide), t-butyl peroxy-2-ethyl hexanoate, t-butyl peroxy bivalate, t-butyloxyneodecanate, diisopropyl peroxy dicarbonate, diethoxy peroxide. Consisting of oxy dicarbonate, bis-(4-t-butylcyclohexyl) peroxy dicarbonate, dimethoxy isopropyl peroxy dicarbonate, dicyclohexyl peroxy dicarbonate and 3,3,5-trimethylhexanoyl peroxide. It may be any one or more selected from the group.

The content of the peroxide may be 0.02 to 1% by weight, preferably 0.03 to 0.07% by weight, based on 100% by weight of the polypropylene composition. If the peroxide content is less than the lower limit, compatibility may be reduced and the size of the gap between the cellulose fiber and impact polypropylene may be greater than 0.3 μm. Conversely, if it is greater than the upper limit, the mechanical properties of the polypropylene resin may be reduced.

The impact polypropylene is made of ethylene-propylene rubber (EPR) and polypropylene homopolymer.

The impact polypropylene is characterized in that it has a melt index of 20.1 to 40 g/10 min, preferably 27 to 33 g/10 min. If the melt index is less than the lower limit, the dispersion of the cellulose fibers may be very low, making extrusion processing difficult. On the other hand, if it exceeds the above upper limit, compatibility may be low due to the difference in fluidity between impact polypropylene and cellulose fibers, which may lower the dispersion of the final product.

The content of ethylene-propylene rubber may be 25% by weight or less, preferably 15 to 23% by weight, based on 100% by weight of the total impact polypropylene. If the content of ethylene-propylene rubber exceeds 25% by weight, granulation of the polypropylene resin composition may be difficult due to low dispersion, and if it is homo polypropylene rather than impact polypropylene, the impact strength is very low, making application to injection products difficult. You can.

The impact polypropylene may be included in an amount of 50 to 80 wt%, preferably 52 to 59 wt%, based on 100 wt% of the total polypropylene resin composition. If the content of impact polypropylene is less than the above lower limit, the physical properties of the polypropylene resin composition may deteriorate, and conversely, if it exceeds the above upper limit, the content of biomass-derived carbon decreases, making it impossible to meet the standards for bio-based PP among eco-friendly plastics. .

The polypropylene composition may be prepared by mixing at 170 to 180 °C. If the mixing temperature is below the lower limit, each component may not be mixed uniformly, and conversely, if the mixing temperature is above the upper limit, the cellulose fibers may be carbonized.

In particular, although not explicitly described in the following Examples or Comparative Examples, in the polypropylene resin composition according to the present invention, the polypropylene resin composition and the polypropylene molded product using the same were manufactured by varying the following conditions, and then 300 g of the polypropylene resin composition and the polypropylene molded product using the same were manufactured. Impact resistance was evaluated by repeatedly dropping the weight 30 times from 30 cm.

As a result, unlike other conditions and other numerical ranges, no cracks or destruction occurred even after the fall evaluation when all of the following conditions were satisfied.

Based on the total 100% by weight of the polypropylene composition, the cellulose fibers are included in an amount of 35 to 40% by weight, the maleic anhydride polypropylene is included in an amount of 1 to 4% by weight, and the peroxide is included in an amount of 0.03 to 0.07% by weight. , the impact polypropylene is contained in 52 to 59% by weight,

The peroxide is 2.5-dimethyl-2.5-di-thi-butyl peroxyhexane,

The size of the cellulose fiber is 10 to 250 ㎛,

The melt index of the impact polypropylene is 27 to 33 g/10min,

The content of ethylene-propylene rubber of the impact polypropylene is 15 to 23% by weight,

The polypropylene composition may be prepared by mixing at 170 to 180 °C.

However, if any of the above conditions were not satisfied, it was confirmed that cracks were generated or destroyed after repeated fall evaluation.

Another aspect of the present invention provides a polypropylene molded article manufactured using the polypropylene resin composition.

The polypropylene molded article may be manufactured by injection processing the polypropylene composition at 170 to 180 °C. If the injection temperature is below the lower limit, the melt flow of the polypropylene composition may be inhibited, and conversely, if the injection temperature is above the upper limit, the cellulose fibers may be carbonized.

The polypropylene molded product can be used as automobile parts, food containers, or packaging materials.

Examples 1 to 2

Cellulose fibers surface-modified with alkenyl succinic anhydride were prepared by reacting cellulose fibers with a size of 10 to 250 ㎛ and alkenyl succinic anhydride in an aqueous system. In addition, impact polypropylene, 2.5-dimethyl-2.5-di-thi-butyl peroxy hexane, and maleic anhydride polypropylene with a melt index of 30 g/10 min and an ethylene-propylene rubber content of 20% by weight were prepared. Then, according to the content ratio shown in Table 1 below, cellulose fiber surface-modified with alkenyl succinic anhydride, peroxide, maleic anhydride polypropylene, and impact polypropylene were mixed through an extruder at 180 ° C. for 20 seconds to prepare a polypropylene resin composition. It was manufactured and granulated. Then, the polypropylene resin composition was injection molded at 180°C to obtain a molded product.

Photographic images of the granulated polypropylene resin compositions and polypropylene molded articles of Examples 1 and 2 are shown in Figure 1.

Comparative Example 1

Petroleum-based polypropylene PP ME100 (Grade Name) was purchased and prepared from S-OIL.

Comparative Example 2

Petroleum-based polypropylene PP MG100 (Grade Name) was purchased and prepared from S-OIL.

Comparative Example 3

Polypropylene resin was prepared in the same manner as in Example 1, except that 56% by weight of impact polypropylene, 4% by weight of maleic anhydride polypropylene, and 40% by weight of cellulose fibers surface-modified with alkenyl succinic anhydride were used without adding peroxide. A composition was prepared.

division Example 1 Example 2 Comparative Example 3 Weight% (wt%) Base Impact PP 55.97 55.95 56 MaPP 4 4 4 CMF 40 40 40 Peroxide 0.03 0.05 0

Experimental Example 1. Physical property evaluation

The physical properties of the polypropylene prepared in Examples 1 to 2 and Comparative Examples 1 to 3 were evaluated according to the method below, and the results are shown in Table 2 below.

(1) Melt flow index (MI): Measured at 230°C and 2.16 kg according to the evaluation method specified in ASTM D1238.

(2) Flexural Modulus: Measured according to the evaluation method specified in ASTM D790.

(3) Flexural Strength: Measured according to the evaluation method specified in ASTM D790.

(4) Tensile Strength and Tensile Elongation: Measured according to the evaluation method specified in ASTM D638.

(5) IZOD impact strength: Measured at room temperature and low temperature according to the evaluation method specified in ASTM D256.

(6) Rockwell Hardness (HRR): Measured according to the evaluation method specified in ASTM D785.

(6) Heat deflection temperature (HDT): Measured according to the evaluation method specified in ASTM D648.

division Example 1 Example 2 Comparative Example 1 Comparative example 2 Comparative Example 3 Melt Index (g/10min) 9.2 12.4 5.8 9.2 5.4 Flexural Modulus (MPa) 2,880 2,840 1198 1413 2,980 Flexural Strength (MPa) 48 50 33.38 37.01 45 Tensile Strength at Yield (MPa) 29 30 27 27 28 Tensile Elongation at Yield (%) 3 3 5.6 4.8 2.3 Tensile Strength at Break (MPa) 27.9 29.0 17 17 28.2 Tensile Elongation at Break (%) 5 5 >100 >100 2.8 Izod Impact Strength at 23℃ (J/m) 25 28 11 12 24 Izod Impact Strength at -20℃ (J/m) 22 24 4 5 19 Rockwell Hardness (HRR) 99 100 96 97 98 HDT (℃) 146 147 108 119 145

As shown in Table 2, it can be seen that the polypropylene resin composition of the present invention exhibits physical properties equal to or higher than those of conventional petroleum-based polypropylene (Comparative Examples 1 and 2) with similar melt indexes. At the same time, the flexural modulus and heat deflection temperature of the polypropylene resin composition of the present invention showed excellent levels compared to Comparative Examples 1 and 2.

Through this, the polypropylene resin composition of the present invention includes cellulose fibers surface-modified with alkenyl succinic anhydride; maleic anhydride polypropylene; peroxide; and impact polypropylene with a melt index of 20.1 to 40 g/10 min. In addition to being environmentally friendly, the compatibility between components is significantly improved, so that it has mechanical properties equivalent to or better than existing polypropylene and improves rigidity and heat resistance. It was confirmed that it was possible.

Experimental Example 2

Figure 2 shows a scanning electron microscope (SEM) image of the polypropylene resin prepared in (a) Comparative Example 3, (b) Example 1, and (c) Example 2 of the present invention.

Table 3 below shows the pore sizes of cellulose fibers and polymer matrices.

division Comparative Example 3 Example 1 Example 2 Average Gap between CMF and Polymer Matrix
(μm, From SEM Analysis) 0.34 0.19 0.16

Referring to Figure 2 and Table 2, it can be seen that the pore size was reduced in Examples 1 and 2 compared to Comparative Example 3 in which peroxide was not added, indicating that the polypropylene resin of the present invention has excellent compatibility.

Claims (11)

(a) Cellulose fibers (CMF) surface modified with alkenyl succinic anhydride (ASA);
(b) Maleic Anhydride Polypropylene (MaPP);
(c) Peroxide; and
(d) impact polypropylene;
A polypropylene resin composition, characterized in that the melt index of the impact polypropylene is 20.1 to 40 g/10min. The polypropylene resin composition according to claim 1, wherein the cellulose fibers have a size of 10 to 250 ㎛. The polypropylene resin composition according to claim 1, wherein the cellulose fibers are contained in an amount of 20 to 45% by weight based on 100% by weight of the total polypropylene resin composition. The polypropylene resin composition according to claim 1, wherein the maleic anhydride polypropylene is contained in an amount of 1 to 4 wt% based on 100 wt% of the total polypropylene resin composition. The polypropylene resin composition according to claim 1, wherein the peroxide is contained in an amount of 0.02 to 1% by weight based on 100% by weight of the total polypropylene resin composition. The polypropylene resin composition according to claim 1, wherein the content of ethylene-propylene rubber is 25% by weight or less based on 100% by weight of the total impact polypropylene. The polypropylene resin composition according to claim 1, wherein the impact polypropylene is contained in an amount of 50 to 80 wt% based on 100 wt% of the total polypropylene resin composition. The polypropylene resin composition according to claim 1, wherein the polypropylene composition is prepared by mixing at 170 to 180 °C. According to paragraph 1,
Based on the total 100% by weight of the polypropylene composition, the cellulose fibers are included in an amount of 35 to 40% by weight, the maleic anhydride polypropylene is included in an amount of 1 to 4% by weight, and the peroxide is included in an amount of 0.03 to 0.07% by weight. , the impact polypropylene is contained in 52 to 59% by weight,
The peroxide is 2.5-dimethyl-2.5-di-thi-butyl peroxyhexane,
The size of the cellulose fiber is 10 to 250 ㎛,
The melt index of the impact polypropylene is 27 to 33 g/10min,
The content of ethylene-propylene rubber of the impact polypropylene is 15 to 23% by weight,
A polypropylene resin composition, characterized in that the polypropylene composition is prepared by mixing at 170 to 180 ° C. A polypropylene molded article manufactured using the polypropylene resin composition according to any one of claims 1 to 9. The polypropylene molded article according to claim 10, wherein the polypropylene molded article is manufactured by injection processing the polypropylene resin composition at 170 to 180°C.