Modified polyolefin resin composition and preparation method thereof, and hot-melt marking paint

Abstract

The invention discloses a modified polyolefin resin composition which mainly comprises the following components in parts by weight: 90-102 parts of polar monomer grafted polyethylene and polar monomer grafted polyethylene wax, 67-90 parts of a polyethylene chain segment and 9-30 parts of a polyethylene wax chain segment. In the modified polyolefin resin composition, the grafting ratio of the polar monomer ranges from 0.8 wt% to 2.0 wt%; polyethylene in the polar monomer grafted polyethylene is selected from at least one of LDPE (Low-Density Polyethylene) and LLDPE (Linear Low-Density Polyethylene). The modified polyolefin resin composition disclosed by the invention is suitable for adhesion promoting resin of hot-melt marking paint.

Description

Technical Field

[0001] The invention relates to the technical field of polymer materials, in particular to a modified polyolefin resin composition and a preparation method thereof and a hot-melt road marking paint. Background Art

[0002] Road marking paint is also called road marking paint, which is mainly divided into two categories: hot melt type and solvent type. Hot melt type road marking paint currently dominates the road marking paint in my country due to its advantages such as low cost, fast drying, thick coating, simple construction, environmental protection and low odor, accounting for about 90% of the total usage.

[0003] The hot melt road marking paint on the market is mainly made of C5 petroleum resin compounded with pigments, fillers, PE wax and other additives. The polarity of this system is weak and the adhesion to the ground is average. Therefore, in actual construction, a layer of primer is first applied to the ground, and then the hot melt road marking paint is applied to improve the firmness. However, due to long-term outdoor use, hot melt road markings have to withstand sunlight, blisters, tire rolling, etc. After 6-9 months of actual use, hot melt road markings are prone to peeling, resulting in blurred markings, causing road traffic hazards.

[0004] Patent CN 114621622 B discloses a hot melt road marking modified material, which includes polyvinyl chloride, polyamide resin, ABS resin, polytetrafluoroethylene, polyetheretherketone, ethylene-vinyl acetate copolymer, styrene-butadiene-styrene front-end copolymer, silane coupling agent, fatty alcohol polyoxyethylene ether sodium sulfate and methylsilicic acid. After the hot melt road marking modified material is added to the hot melt road marking modified coating, it can significantly improve the bonding performance between the road marking coating and glass microbeads, thereby improving the durability of the retroreflective coefficient of the road marking. However, this patent is mainly aimed at improving the bonding strength between the hot melt road marking coating and the glass microbeads, and has limited effect on the bonding strength between the hot melt road marking coating and the primer. Summary of the invention

[0005] The object of the present invention is to provide a modified polyolefin resin composition which can enhance the adhesion between hot melt road marking paint and primer.

[0006] The present invention is achieved through the following technical solutions: A modified polyolefin resin composition comprises the following components in parts by weight: Polar monomer grafted polyethylene and polar monomer grafted polyethylene wax total 90-102 parts, of which polyethylene segments are 67-90 parts and polyethylene wax segments are 9-30 parts; In the modified polyolefin resin composition, the grafting rate of the polar monomer is in the range of 0.8-2.0wt%; The polyethylene in the polar monomer grafted polyethylene is selected from at least one of LDPE and LLDPE.

[0007] Preferably, in the modified polyolefin resin composition, the grafting rate of the polar monomer is in the range of 1.2-1.7 wt%. In the modified polyolefin resin composition, the grafting rate of the polar monomer can be 0.8 wt%, 0.9 wt%, 1.0 wt%, 1.1 wt%, 1.2 wt%, 1.3 wt%, 1.4 wt%, 1.5 wt%, 1.6 wt%, 1.7 wt%, 1.8 wt%, 1.9 wt%, 2.0 wt%, etc.

[0008] In the modified polyolefin resin composition of the present invention, the polar monomer grafted polyethylene and the polar monomer grafted polyethylene wax account for a total weight percentage of not less than 97wt%.

[0009] The testing method for the polar monomer content in the modified polyolefin resin composition is: acid-base titration method.

[0010] The specific operation method is: put the grafted material into xylene and heat it under reflux to dissolve, after cooling, add a certain amount of 0.05mol / L potassium hydroxide-ethanol solution, and then heat it under reflux for 8h, use 0.1% phenolphthalein solution as an indicator, and titrate to the end point with 0.05mol / L HCl-isopropanol solution while it is hot. The grafting rate G is calculated by the following formula: G = (N1 × Vl - N2 × V2) × M ÷ w ÷ 10 Where: N1: KOH-ethanol solution equivalent concentration, N; V1: volume of KOH-ethanol solution, ml; N2: HCl-isopropanol solution equivalent concentration, N; V2: volume of HCl-isopropanol solution, ml; M: equivalent mass of maleic anhydride, g; w: weight of the dried sample after extraction, g.

[0011] The modified polyolefin resin composition of the present invention has a melt index of 50-500 g / 10 min at 190° C. and 2.16 kg.

[0012] The polar monomer is selected from at least one of maleic anhydride, methyl methacrylate, methacrylic acid, acrylic acid, acrylamide and glycidyl methacrylate.

[0013] Preferably, the polar monomer is selected from maleic anhydride.

[0014] It is possible to choose whether to add 0-2 parts of auxiliary agent according to actual conditions, wherein the auxiliary agent is selected from at least one of an anti-crosslinking agent, an antioxidant, and a lubricant.

[0015] The modified polyolefin resin composition of the present invention can be prepared by a one-pot process, or by first melt-blending the polar monomer grafted polyethylene and the polar monomer grafted polyethylene wax. The one-pot process is preferred.

[0016] Specifically, the one-pot preparation method comprises the following steps: according to the polar monomer grafting rate and the weight content of polyethylene polyethylene wax in the modified polyolefin resin composition, the polar monomer, the initiator and the anti-crosslinking agent are mixed and dispersed in a solvent, the weight of the solvent is 0.5-2 times the total weight of the polar monomer, the initiator and the anti-crosslinking agent, and then uniformly mixed with polyethylene and polyethylene wax, and extruded and granulated by a twin-screw extruder (the screw temperature is 150-180°C, and the aspect ratio is greater than or equal to 40:1) to obtain a modified polyolefin resin composition; The solvent is selected from acetone, methanol, ethyl acetate, etc., and most of the solvent will evaporate during the preparation process.

[0017] Preferably, the initiator is selected from at least one of dicumyl peroxide, di-tert-butyl peroxide, tert-butyl hydroperoxide and cumene hydroperoxide, and the amount of the initiator used is in the range of 0.1-0.5wt% of the amount of polyethylene and polyethylene wax added; and / or The anti-crosslinking agent is selected from at least one of caprolactam, dimethylformamide, dimethylacetamide, dimethyl sulfoxide, and thioester, and the amount of the anti-crosslinking agent is 0.5-2 times the amount of the initiator added; and / or The LDPE and LLDPE that can achieve the purpose of the present invention have a melt index of 50-100 g / 10 min at 190° C. and 2.16 kg. And / or The weight average molecular weight of the polyethylene wax that can achieve the purpose of the present invention is 500-2000. The weight average molecular weight is measured by GPC.

[0018] Another preparation method of the modified polyolefin resin composition of the present invention is to mix and extrude polar monomer grafted polyethylene and polar monomer grafted polyethylene wax through a twin-screw extruder at an extrusion temperature of 160-200° C. and a screw speed of 300-400 rpm.

[0019] Preferably, in the polar monomer grafted polyethylene, the grafting rate of the polar monomer is in the range of 0.8-2.0wt%, more preferably 1.2-1.7wt%; Preferably, in the polar monomer grafted polyethylene wax, the grafting rate of the polar monomer is in the range of 0.8-2.0 wt %, more preferably 1.2-1.7 wt %.

[0020] In the modified polyolefin resin composition, the polar monomer grafted polyethylene and the polar monomer grafted polyethylene wax may have the same or different polar monomer grafting ratios. The polar monomer grafted polyethylene and the polar monomer grafted polyethylene wax may have grafting ratios of 0.8wt%, 0.9wt%, 1.0wt%, 1.1wt%, 1.2wt%, 1.3wt%, 1.4wt%, 1.5wt%, 1.6wt%, 1.7wt%, 1.8wt%, 1.9wt%, 2.0wt%, etc., respectively.

[0021] Polar monomer grafted polyethylene (or polar monomer grafted polyethylene wax) can be commercially available or prepared by oneself. The preparation method is as follows: polar monomer, initiator and polyethylene (or polyethylene wax) are uniformly mixed, and granulated by extrusion through a twin-screw extruder (screw temperature is 150-180°C, aspect ratio is greater than or equal to 40:1) to obtain polar monomer grafted polyethylene (or polar monomer grafted polyethylene wax).

[0022] A hot melt road marking paint, comprising the following components in parts by weight: Petroleum resin 15-25 parts; 3-7 parts of polyethylene wax; 3-7 parts of titanium dioxide; Calcium carbonate powder 50-90 parts; 3-7 parts of the modified polyolefin resin composition of the present invention.

[0023] The petroleum resin is selected from C5 petroleum resin, C9 petroleum resin, hydrogenated C5 petroleum resin, hydrogenated C9 petroleum resin, C5 / C9 mixed petroleum resin and the like.

[0024] In the hot-melt marking paint of the present invention, the content of petroleum resin by weight can be 15 parts, 17 parts, 19 parts, 21 parts, 23 parts, 25 parts, etc.; the content of polyethylene wax can be 3 parts, 4 parts, 5 parts, 6 parts, 7 parts, etc.; the content of titanium dioxide can be 3 parts, 4 parts, 5 parts, 6 parts, 7 parts, etc.; the content of calcium carbonate powder can be 50 parts, 55 parts, 60 parts, 65 parts, 70 parts, 75 parts, 80 parts, 85 parts, 90 parts, etc.; the content of the modified polyolefin resin composition of the present invention can be 3 parts, 4 parts, 5 parts, 6 parts, 7 parts, etc.

[0025] Those skilled in the art may also choose to add other additives to the hot melt road marking paint according to actual needs. The other additives may be 0-2 parts of an anti-ultraviolet agent or the like.

[0026] The present invention has the following beneficial effects: The present invention obtains a high-fluidity and high-polarity polyolefin grafted polar monomer resin by grafting polyethylene with polar monomers in a specific proportion and a specific grafting rate, and grafting polyethylene wax with polar monomers. Due to its good fluidity, the resin can be well dispersed in hot-melt road marking paint, and can also have a synergistic effect with petroleum resin, significantly improving the adhesion between the hot-melt road marking paint and the base oil, achieving the effect of an adhesion promoter. DETAILED DESCRIPTION

[0027] The present invention is described in detail below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those of ordinary skill in the art, several variations and improvements may be made without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

[0028] The sources of raw materials used in the present invention are as follows: LLDPE-1: ExxonMobil 6201, melt index 50 g / 10min, 190℃, 2.16kg.

[0029] LLDPE-2: DOW LLDPE DNDA-1082, melt index 160g / 10min, 190℃, 2.16kg.

[0030] LDPE: Sinopec LDPE 868-000, melt index 50 g / 10min, 190℃, 2.16kg.

[0031] HDPE: HDPE 8920, melt index 20g / 10min, 190℃, 2.16kg.

[0032] Polyethylene wax-1: weight average molecular weight 800, R-110, Yiteng Chemical.

[0033] Polyethylene wax-2: weight average molecular weight 1500, DP0020F, Qingdao East.

[0034] Maleic anhydride: Yunsheng Chemical (Shandong) Co., Ltd.

[0035] Acrylamide: MacLean.

[0036] Glycidyl methacrylate (GMA): Jinan Huijinchuan Chemical Co., Ltd.

[0037] Acetone: Qiming Chemical.

[0038] Dicumyl peroxide: Shandong Haijing New Materials Co., Ltd.

[0039] Dimethylformamide: Zibo Zida Chemical Trading Co., Ltd.

[0040] Polar monomer grafted polyethylene-1: maleic anhydride grafting rate 0.83wt%, main chain LLDPE-2, homemade; Polar monomer grafted polyethylene-2: maleic anhydride grafting rate 1.27wt%, main chain LLDPE-2, homemade; Polar monomer grafted polyethylene-3: maleic anhydride grafting rate 1.66wt%, main chain LLDPE-2, homemade; Polar monomer grafted polyethylene-4: maleic anhydride grafting rate 1.92wt%, main chain LLDPE-2, homemade; Polar monomer grafted polyethylene-5: maleic anhydride grafting rate 0.36wt%, main chain LLDPE-2, homemade; Polar monomer grafted polyethylene-6: maleic anhydride grafting rate 2.38wt%, main chain LLDPE-2, homemade; Polar monomer grafted polyethylene-7: GMA grafting rate 1.61wt%, main chain LLDPE-2, homemade; Polar monomer grafted polyethylene wax-1: maleic anhydride grafting rate 0.88wt%, main chain polyethylene wax-1, homemade; Polar monomer grafted polyethylene wax-2: maleic anhydride grafting rate 1.20wt%, main chain polyethylene wax-1, homemade; Polar monomer grafted polyethylene wax-3: maleic anhydride grafting rate 1.64wt%, main chain polyethylene wax-1, homemade; Polar monomer grafted polyethylene wax-4: maleic anhydride grafting rate 1.95wt%, main chain polyethylene wax-1, homemade; Polar monomer grafted polyethylene wax-5: maleic anhydride grafting rate 0.31wt%, main chain polyethylene wax-1, homemade; Polar monomer grafted polyethylene wax-6: maleic anhydride grafting rate 2.40wt%, main chain polyethylene wax-1, homemade; Polar monomer grafted polyethylene wax-7: GMA grafting rate 1.65wt%, main chain polyethylene wax-2, homemade; The preparation method of the above polar monomer grafted polyethylene or polar monomer grafted polyethylene wax is as follows: polar monomer, initiator (dicumyl peroxide), polyethylene (or polyethylene wax) are uniformly mixed, and extruded and granulated by a twin-screw extruder, with the screw temperature being 150-180°C and the aspect ratio being 44:1, to obtain polar monomer grafted polyethylene (or polar monomer grafted polyethylene wax). The polar monomer grafting rate is then determined by acid-base titration.

[0041] C5 petroleum resin: Jinda Chemical.

[0042] Titanium dioxide: Longman Baili.

[0043] Calcium carbonate powder: Guangxi Hezhou Junfei Powder Co., Ltd.

[0044] The preparation method of the modified polyolefin resin composition A in the embodiments and comparative examples is as follows: a polar monomer, an initiator (diisopropylbenzene peroxide), and an anti-crosslinking agent (dimethylformamide) are mixed and dispersed in a solvent (acetone), wherein the weight of the solvent is 1.0 times the total weight of the polar monomer, the initiator, and the anti-crosslinking agent, the amount of the initiator is in the range of 0.2wt% of the amount of polyethylene and polyethylene wax added, and the amount of the anti-crosslinking agent is in the range of 1 times the amount of the initiator added, and then uniformly mixed with polyethylene and polyethylene wax, and extruded and granulated by a twin-screw extruder, the screw temperature is 150-180°C, and the aspect ratio is 44:1, to obtain a modified polyolefin resin composition.

[0045] The preparation method of the modified polyolefin resin composition B in the embodiments and comparative examples is as follows: polar monomer grafted polyethylene, polar monomer grafted polyethylene wax and additives are melt-extruded through a twin-screw extruder, wherein the barrel temperature is 160-200°C, and the screw speed is 300-400rpm to obtain a modified polyolefin resin composition.

[0046] The preparation method of the hot melt road marking paint is as follows: 20 parts of C5 petroleum resin, 5 parts of polyethylene wax, 4 parts of titanium dioxide, 70 parts of calcium carbonate powder and modified polyolefin resin composition A (or B) are uniformly mixed and ground to obtain the hot melt road marking paint.

[0047] Various test methods: (1) Softening point of hot melt road marking paint: refer to GB / T16311-2009 Road Traffic Marking Quality Requirements and Test Methods; (2) Compressive strength of hot melt road marking paint: refer to GB / T16311-2009 quality requirements and test methods for road traffic markings; (3) Peel strength of hot melt marking paint: refer to GB / T2792-1998 pressure-sensitive tape 180° peel strength test method.

[0048] (4) Melt index: The test standard is ISO 1133-1:2022, and the conditions are 190°C and 2.16 kg.

[0049] (5) Polar monomer content test: Place the grafted material in xylene and heat it under reflux to dissolve. After cooling, add a certain amount of 0.05 mol / L potassium hydroxide-ethanol solution, heat it under reflux for 8 hours, use 0.1% phenolphthalein solution as an indicator, and titrate it with 0.05 mol / L HCl-isopropanol solution to the end point while it is hot. The grafting rate G is calculated using the following formula: G = (N1 × Vl - N2 × V2) × M ÷ w ÷ 10 Where: N1: KOH-ethanol solution equivalent concentration, N; V1: volume of KOH-ethanol solution, ml; N2: HCl-isopropanol solution equivalent concentration, N; V2: volume of HCl-isopropanol solution, ml; M: equivalent mass of maleic anhydride, g; w: weight of the dried sample after extraction, g.

[0050] Table 1: Addition amount (parts by weight) of each component of modified polyolefin resin composition A1-A6 and test results A1 A2 A3 A4 A5 A6 LLDPE-1 67.5 LLDPE-2 77 77 77 77 LDPE 85.5 Polyethylene wax-1 28.5 17 17 17 17 Polyethylene wax-2 9.5 Maleic anhydride 3.5 2.0 3.0 4.0 5.0 GMA 5.0 Polar monomer grafting rate wt% 1.47 1.83 0.83 1.13 1.65 1.91 Melt index g / 10min 271 55 112 155 190 233 Table 2: Addition amount (parts by weight) of each component of modified polyolefin resin composition A7-A12 and test results A7 A8 A9 A10 A11 A12 LLDPE-2 77 77 77 57 91 HDPE 77 Polyethylene wax-1 17 17 17 17 37 3 Maleic anhydride 4.0 1.0 7.0 4.0 4.0 Acrylamide 4.0 Polar monomer grafting rate wt% 1.59 1.56 0.46 2.81 1.61 1.57 Melt index g / 10min 91 110 56 254 240 35 Table 3: Addition amount (parts by weight) of each component of modified polyolefin resin compositions B1-B7 and test results B1 B2 B3 B4 B5 B6 B7 Polar monomer grafted polyethylene label -1 -2 -3 -4 -7 -1 -2 Content of polar monomer grafted polyethylene 77 77 77 77 77 90 69.5 Polar monomer grafted polyethylene wax label -1 -2 -3 -4 -7 -4 -3 Content of polar monomer grafted polyethylene wax 17 17 17 17 17 9.5 30 Polar monomer grafting rate wt% 0.85 1.24 1.65 1.94 1.62 0.93 1.38 Melt index g / 10min 106 139 163 196 184 95 130 Table 4: Addition amount (parts by weight) of each component of modified polyolefin resin composition B8-B13 and test results B8 B9 B10 B11 B12 B13 Polar monomer grafted polyethylene label -5 -6 -1 -1 -1 / Content of polar monomer grafted polyethylene 69.5 79 60 99.5 95.5 / Polar monomer grafted polyethylene wax label -6 -5 -1 / -1 -1 Content of polar monomer grafted polyethylene wax 30 20 39.5 / 4 99.5 Polar monomer grafting rate wt% 0.97 1.96 0.86 0.83 0.85 0.88 Melt index g / 10min 298 281 179 30 51 370 The preparation method of the hot melt road marking paint is as follows: 20 parts of C5 petroleum resin, 5 parts of polyethylene wax, 4 parts of titanium dioxide, 70 parts of calcium carbonate powder and modified polyolefin resin composition A (or B) are uniformly mixed and ground to obtain the hot melt road marking paint.

[0051] Table 5: Test results of thermoplastic road marking paints for examples and comparative examples Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Modified polyolefin resin composition A1 A2 A3 A4 A5 A6 A7 Softening point (℃) 122 118 124 129 128 122 126 Compressive strength (MPa) 18.0 18.2 18.4 19.1 18.8 18.1 18.9 Peel strength (N / 25mm) 128 132 131 139 140 135 135 Table 5 continued: Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Modified polyolefin resin composition A8 A9 A10 A11 A12 Softening point (℃) 122 122 124 125 116 Compressive strength (MPa) 18.2 19.0 18.6 17.4 18.5 Peel strength (N / 25mm) 87 82 96 81 91 From Examples 1-7, it can be seen that the peel strength of the hot melt road marking paint modified by the modified polyolefin composition obtained by the one-pot method of the present invention is greater than 120 N / 25mm. When the polar monomer grafting rate in the modified polyolefin composition is 1.2-1.7wt%, the peel strength is higher.

[0052] It can be seen from Comparative Example 1 that the peel strength of the hot melt road marking paint is low when high-density polyethylene is selected.

[0053] It can be seen from Comparative Example 2 that when the grafting rate of the polar monomer is too low, the peel strength of the hot melt road marking paint is low.

[0054] It can be seen from Comparative Example 3 that when the grafting rate of the polar monomer is too high, the peel strength of the hot melt road marking paint decreases significantly.

[0055] It can be seen from Comparative Example 4 that if the polyethylene wax content is too high, the peel strength of the hot melt road marking paint is low and the compressive strength is also poor.

[0056] It can be seen from Comparative Example 5 that when the polyethylene wax content is too low, the peel strength of the hot melt road marking paint is low.

[0057] Table 5 continued: Example 8 Example 9 Example 10 Embodiment 11 Example 12 Embodiment 13 Embodiment 14 Modified polyolefin resin composition B1 B2 B3 B4 B5 B6 B7 Softening point (℃) 121 126 124 119 125 122 124 Compressive strength (MPa) 18.0 18.8 18.5 17.7 18.3 18.3 18.9 Peel strength (N / 25mm) 125 135 138 131 136 128 137 Table 5 continued: Embodiment 15 Example 16 Comparative Example 6 Comparative Example 7 Comparative Example 8 Comparative Example 9 Modified polyolefin resin composition B8 B9 B10 B11 B12 B13 Softening point (℃) 121 118 123 115 117 112 Compressive strength (MPa) 18.4 17.9 17.2 18.2 18.5 17.4 Peel strength (N / 25mm) 134 129 90 96 100 85 As can be seen from Examples 8-16, the purpose of the present invention can be achieved when the polar monomer grafting rate of the modified polyolefin resin composition obtained by melt blending polar monomer grafted polyethylene and polar monomer grafted polyethylene wax is within the scope of the present invention. The modified polyolefin resin composition obtained by one-pot method is preferred.

[0058] Moreover, when the grafting rate of polar monomers in the modified polyolefin composition is 1.2-1.7 wt %, the peel strength is higher.

[0059] It can be seen from Comparative Example 6 that when the content of maleic anhydride grafted polyethylene wax is too high and is not within the protection scope of the present invention, the peel strength and compressive strength of the hot melt road marking paint are low.

[0060] It can be seen from Comparative Example 7 that the peel strength of the hot melt road marking paint is low when the polar monomer grafted polyethylene wax is not contained.

[0061] It can be seen from Comparative Example 8 that when the content of polar monomer grafted polyethylene is too high, the peel strength of the hot melt road marking paint is low.

[0062] It can be seen from Comparative Example 9 that when the polar monomer grafted polyethylene is not contained, the peel strength of the hot-melt road marking paint is low and the compressive strength is even lower.

Claims

1. A modified polyolefin resin composition, characterized in that By weight, it includes the following components: Polar monomer grafted polyethylene and polar monomer grafted polyethylene wax total 90-102 parts, of which polyethylene segments are 67-90 parts and polyethylene wax segments are 9-30 parts; In the modified polyolefin resin composition, the grafting rate of the polar monomer is in the range of 0.8-2.0wt%; The polyethylene in the polar monomer grafted polyethylene is selected from at least one of LDPE and LLDPE.

2. The modified polyolefin resin composition according to claim 1, characterized in that In the modified polyolefin resin composition, the grafting rate of the polar monomer is in the range of 1.2-1.7 wt %.

3. The modified polyolefin resin composition according to claim 1, characterized in that The polar monomer is selected from at least one of maleic anhydride, methyl methacrylate, methacrylic acid, acrylic acid, acrylamide and glycidyl methacrylate.

4. The modified polyolefin resin composition according to claim 3, characterized in that The polar monomer is selected from maleic anhydride.

5. The modified polyolefin resin composition according to claim 1, characterized in that By weight, the invention also includes 0-2 parts of auxiliary agents, wherein the auxiliary agents are selected from at least one of anti-crosslinking agents, antioxidants and lubricants.

6. The modified polyolefin resin composition according to claim 1, characterized in that In the polar monomer grafted polyethylene, the grafting rate of the polar monomer is in the range of 0.8-2.0wt%, preferably 1.2-1.7wt%; in the polar monomer grafted polyethylene wax, the grafting rate of the polar monomer is in the range of 0.8-2.0wt%, preferably 1.2-1.7wt%.

7. The modified polyolefin resin composition according to claim 1, characterized in that The modified polyolefin resin composition has a melt index of 50-500 g / 10 min at 190° C. and 2.16 kg.

8. The method for preparing the modified polyolefin resin composition according to any one of claims 1 to 7, characterized in that: The following steps are involved: The polar monomer, initiator and anti-crosslinking agent are mixed and dispersed in a solvent, wherein the weight of the solvent is 0.5-2 times the total weight of the polar monomer, initiator and anti-crosslinking agent, and then uniformly mixed with polyethylene and polyethylene wax, and extruded and granulated by a twin-screw extruder to obtain a modified polyolefin resin composition; Preferably, the initiator is selected from at least one of dicumyl peroxide, di-tert-butyl peroxide, tert-butyl hydroperoxide and cumene hydroperoxide; and / or The molecular weight of the polyethylene wax is 500-2000; and / or The polyethylene has a melting index of 50-100 g / 10 min at 190° C. and 2.16 kg.

9. A hot melt road marking paint, characterized in that: By weight, it includes the following components: Petroleum resin 15-25 parts; 3-7 parts of polyethylene wax; 3-7 parts of titanium dioxide; Calcium carbonate powder 50-90 parts; 3-7 parts of the modified polyolefin resin composition according to any one of claims 1-7.

10. The hot melt road marking paint according to claim 9, characterized in that: The petroleum resin is selected from at least one of C5 petroleum resin, C9 petroleum resin, hydrogenated C5 petroleum resin and hydrogenated C9 petroleum resin.