Mixed grafting modification method of chlorinated polyolefin

Abstract

The invention discloses a mixed grafting modification method of chlorinated polyolefin, and relates to the technical field of chlorinated polyolefin modification.The method comprises the steps that polyolefin and chlorine are used as raw materials, additives are added at the same time, chlorinated polyolefin is prepared through a solid-phase chlorination reaction, the chlorinated polyolefin is added into an organic solvent, the temperature is increased, a modifier and an initiator are added, the mixture is stirred for a reaction, and the chlorinated polyolefin is obtained. And cooling after the reaction is finished. According to the invention, the additive is added during the chlorination reaction, and the additive can enable polyolefin to start swelling at a certain temperature section, so that the chlorination reaction is more uniform, and subsequent grafting modification is facilitated. In addition, the vinyl monomer and the cyclic ether are grafted at the tertiary carbon position or the secondary carbon position of the chlorinated polyolefin, so that the compatibility and the stability of the chlorinated polyolefin in other solvents are improved.

Description

Technical Field

[0001] The invention relates to the technical field of chlorinated polyolefin modification, and in particular to a mixed graft modification method for chlorinated polyolefin. Background Art

[0002] Chlorinated polyolefin has excellent adhesion, as well as excellent water resistance, corrosion resistance, mildew resistance and fire resistance, and is mainly used in the field of coatings and inks. However, since chlorinated polyolefin resin is a non-polar substance with crystallinity, unevenness problems may occur during coating and bonding, and chlorinated polyolefin resin has low solubility in resins other than aromatics. For example, Chinese invention patent CN102746472A discloses a modified polypropylene special resin, which uses a chlorinated polyolefin long chain as the skeleton, and the tertiary carbon or secondary carbon position on the chlorinated polyolefin is grafted with a vinyl monomer or / and butadiene rubber or / and a terpene resin. However, this patent cannot fully improve the compatibility of the coating and the stability of the coating, so the chlorinated polyolefin resin needs to be modified. Summary of the invention

[0003] The purpose of the present invention is to solve at least one of the technical problems existing in the prior art and to provide a mixed grafting modification method for chlorinated polyolefins.

[0004] The technical solution of the present invention is as follows:

[0005] A mixed graft modification method for chlorinated polyolefins comprises the following steps: taking polyolefins and chlorine as raw materials, adding additives, and preparing chlorinated polyolefins through solid phase chlorination reaction; adding chlorinated polyolefins into an organic solvent, heating, adding modifiers and initiators, stirring for reaction, and cooling after the reaction is completed.

[0006] As a preferred embodiment of the present invention, the additive is diethyl ketomalonate.

[0007] As a preferred embodiment of the present invention, the initiator is a mixture of benzoyl peroxide and an azo compound initiator.

[0008] As a preferred embodiment of the present invention, the modifier is a vinyl monomer and a cyclic ether compound.

[0009] As a preferred embodiment of the present invention, the vinyl monomer is at least one of methyl acrylate, methyl styrene, methyl methacrylate, hydroxyethyl methacrylate, and butyl methacrylate.

[0010] As a preferred embodiment of the present invention, the cyclic ether compound is 1,3-dioxolane.

[0011] As a preferred embodiment of the present invention, the mass ratio of the chlorinated polyolefin, the initiator and the modifier is 15-30:0.3-0.8:2-9.

[0012] As a preferred embodiment of the present invention, the chlorination reaction temperature is 130-180°C.

[0013] As a preferred embodiment of the present invention, the stirring reaction temperature is 110-150°C.

[0014] The beneficial effects of the present invention are:

[0015] (1) A mixed grafting modification method of chlorinated polyolefins of the present invention comprises adding an additive during the chlorination reaction. The additive can cause the polyolefin to begin to swell at a certain temperature range, making the chlorination reaction more uniform and more conducive to subsequent grafting modification.

[0016] (2) The mixed grafting modification method of chlorinated polyolefin of the present invention improves the compatibility and stability of chlorinated polyolefin in other solvents by grafting vinyl monomer and cyclic ether on the tertiary carbon or secondary carbon position of chlorinated polyolefin. DETAILED DESCRIPTION

[0017] The embodiments of the present invention are described in detail below. The embodiments described below are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention. If no specific techniques or conditions are specified in the embodiments, the techniques or conditions described in the literature in this area or the product specifications are used. The reagents or instruments used that do not specify the manufacturer are all conventional products that can be obtained commercially.

[0018] Example 1

[0019] Polyethylene is heated to 75°C, 3 wt% of diethyl ketomalonate is added dropwise, chlorine gas is introduced after mixing, the temperature is raised to 145°C for chlorination reaction to obtain chlorinated polyethylene, and then the temperature is raised to melt and added to methanol, the temperature is raised to 120°C, an initiator and a modifier are added, the reaction is stirred for 12 hours, and the temperature is lowered after the reaction is completed.

[0020] The mass ratio of the chlorinated polyolefin, the initiator and the modifier is 20:0.3:7.

[0021] The initiator comprises benzoyl peroxide and azobisisobutyronitrile in a mass ratio of 1:1.

[0022] The modifier is methyl styrene and 1,3-dioxolane in a mass ratio of 1:1.

[0023] Example 2

[0024] Polyethylene is heated to 75°C, 5 wt% of diethyl ketomalonate is added dropwise, chlorine gas is introduced after mixing, the temperature is raised to 145°C for chlorination reaction to obtain chlorinated polyethylene, and then the temperature is raised to melt and added to methanol, the temperature is raised to 120°C, an initiator and a modifier are added, the reaction is stirred for 12 hours, and the temperature is lowered after the reaction is completed.

[0025] The mass ratio of the chlorinated polyolefin, the initiator and the modifier is 20:0.3:7.

[0026] The initiator comprises benzoyl peroxide and azobisisobutyronitrile in a mass ratio of 1:1.

[0027] The modifier is methyl styrene and 1,3-dioxolane in a mass ratio of 1:1.

[0028] Example 3

[0029] Polyethylene is heated to 75°C, 7 wt% of diethyl ketomalonate is added dropwise, chlorine gas is introduced after mixing, the temperature is raised to 145°C for chlorination reaction to obtain chlorinated polyethylene, and then the temperature is raised to melt and added to methanol, the temperature is raised to 120°C, an initiator and a modifier are added, the reaction is stirred for 12 hours, and the temperature is lowered after the reaction is completed.

[0030] The mass ratio of the chlorinated polyolefin, the initiator and the modifier is 20:0.3:7.

[0031] The initiator comprises benzoyl peroxide and azobisisobutyronitrile in a mass ratio of 1:1.

[0032] The modifier is methyl styrene and 1,3-dioxolane in a mass ratio of 1:1.

[0033] Example 4

[0034] Polyethylene is heated to 75°C, 5 wt% of diethyl ketomalonate is added dropwise, chlorine gas is introduced after mixing, the temperature is raised to 145°C for chlorination reaction to obtain chlorinated polyethylene, and then the temperature is raised to melt and added to methanol, the temperature is raised to 120°C, an initiator and a modifier are added, the reaction is stirred for 12 hours, and the temperature is lowered after the reaction is completed.

[0035] The mass ratio of the chlorinated polyolefin, the initiator and the modifier is 20:0.3:7.

[0036] The initiator comprises benzoyl peroxide and azobisisobutyronitrile in a mass ratio of 1:1.

[0037] The modifier is methyl styrene and 1,3-dioxolane in a mass ratio of 1:2.

[0038] Example 5

[0039] Polyethylene is heated to 75°C, 3 wt% of diethyl ketomalonate is added dropwise, chlorine gas is introduced after mixing, the temperature is raised to 145°C for chlorination reaction to obtain chlorinated polyethylene, and then the temperature is raised to melt and added to methanol, the temperature is raised to 120°C, an initiator and a modifier are added, the reaction is stirred for 12 hours, and the temperature is lowered after the reaction is completed.

[0040] The mass ratio of the chlorinated polyolefin, the initiator and the modifier is 20:0.3:7.

[0041] The initiator comprises benzoyl peroxide and azobisisobutyronitrile in a mass ratio of 1:1.

[0042] The modifier is methyl styrene and 1,3-dioxolane in a mass ratio of 1:3.

[0043] Example 6

[0044] Polyethylene is heated to 75°C, 3 wt% of diethyl ketomalonate is added dropwise, chlorine gas is introduced after mixing, the temperature is raised to 145°C for chlorination reaction to obtain chlorinated polyethylene, and then the temperature is raised to melt and added to methanol, the temperature is raised to 120°C, an initiator and a modifier are added, the reaction is stirred for 12 hours, and the temperature is lowered after the reaction is completed.

[0045] The mass ratio of the chlorinated polyolefin, the initiator and the modifier is 20:0.3:7.

[0046] The initiator comprises benzoyl peroxide and azobisisobutyronitrile in a mass ratio of 1:1.

[0047] The modifier is methyl styrene and 1,3-dioxolane in a mass ratio of 1:4.

[0048] Comparative Example 1

[0049] Polyethylene is heated to 75°C, chlorine gas is introduced, and the temperature is raised to 145°C for chlorination reaction to obtain chlorinated polyethylene, which is then heated to melt and added to methanol. The temperature is raised to 120°C, an initiator and a modifier are added, and the reaction is stirred for 12 hours. After the reaction is completed, the temperature is lowered to obtain the product.

[0050] The mass ratio of the chlorinated polyolefin, the initiator and the modifier is 20:0.3:7.

[0051] The initiator comprises benzoyl peroxide and azobisisobutyronitrile in a mass ratio of 1:1.

[0052] The modifier is methyl styrene and 1,3-dioxolane in a mass ratio of 1:2.

[0053] Comparative Example 2

[0054] Polyethylene is heated to 75° C., 5 wt% of diethyl ketomalonate is added dropwise, chlorine gas is introduced after mixing, and the temperature is raised to 145° C. for chlorination reaction to obtain chlorinated polyethylene.

[0055] Comparative Example 3

[0056] Polyethylene is heated to 75°C, 5 wt% of diethyl ketomalonate is added dropwise, chlorine gas is introduced after mixing, the temperature is raised to 145°C for chlorination reaction to obtain chlorinated polyethylene, and then the temperature is raised to melt and added to methanol, the temperature is raised to 120°C, an initiator and a modifier are added, the reaction is stirred for 12 hours, and the temperature is lowered after the reaction is completed.

[0057] The mass ratio of the chlorinated polyolefin, the initiator and the modifier is 20:0.3:7.

[0058] The initiator comprises benzoyl peroxide and azobisisobutyronitrile in a mass ratio of 1:1.

[0059] The modifier is methyl styrene.

[0060] The above embodiments and comparative examples were subjected to performance tests, and the test results are shown in Table 1.

[0061] High temperature stability: Keep at 40℃ for 240 hours, cool to room temperature, keep for 3 hours, and test the viscosity change.

[0062] Low temperature stability: Keep at -20℃ for 240 hours, warm to room temperature, keep for 3 hours, and test the viscosity change.

[0063] Table 1 Performance test results of embodiments and comparative examples

[0064]

[0065]

[0066] As can be seen from the table above, the performance of the embodiment is better than that of the comparative example. The main reason may be that the embodiment adds an additive during the chlorination reaction, and the additive can make the polyolefin begin to swell at a certain temperature range, making the chlorination reaction more uniform and more conducive to subsequent grafting modification. Furthermore, the embodiment grafts vinyl monomers and cyclic ethers at the tertiary carbon or secondary carbon position of the chlorinated polyolefin. Since the cyclic ether has a large steric hindrance, the compatibility and stability of the chlorinated polyolefin in other solvents are improved.

[0067] The above-mentioned embodiments only express the preferred implementation modes of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the present invention. It should be pointed out that, for ordinary technicians in this field, various other corresponding changes and deformations can be made according to the technical solutions and concepts described above, and all these changes and deformations should fall within the scope of protection of the claims of the present invention.

Claims

1. A mixed grafting modification method for chlorinated polyolefins, characterized in that: Chlorinated polyolefin is prepared by solid phase chlorination reaction with polyolefin and chlorine as raw materials and additives added at the same time. The chlorinated polyolefin is added into an organic solvent, the temperature is increased, a modifier and an initiator are added, the reaction is stirred, and the temperature is lowered after the reaction is completed.

2. The mixed grafting modification method of a chlorinated polyolefin according to claim 1, characterized in that: The additive is diethyl ketomalonate.

3. The mixed grafting modification method of a chlorinated polyolefin according to claim 1, characterized in that: The initiator is a mixture of benzoyl peroxide and an azo compound initiator.

4. The mixed grafting modification method of a chlorinated polyolefin according to claim 1, characterized in that: The modifiers are vinyl monomers and cyclic ether compounds.

5. The mixed grafting modification method of chlorinated polyolefin according to claim 4, characterized in that: The vinyl monomer is at least one of methyl acrylate, methyl styrene, methyl methacrylate, hydroxyethyl methacrylate, and butyl methacrylate.

6. The mixed grafting modification method of chlorinated polyolefin according to claim 4, characterized in that: The cyclic ether compound is 1,3-dioxolane.

7. The mixed grafting modification method of chlorinated polyolefin according to claim 1, characterized in that: The mass ratio of the chlorinated polyolefin, the initiator and the modifier is 15-30:0.3-0.8:2-9.

8. The mixed grafting modification method of chlorinated polyolefin according to claim 1, characterized in that: The chlorination reaction temperature is 130-180°C.

9. The mixed grafting modification method of chlorinated polyolefin according to claim 1, characterized in that: The stirring reaction temperature is 110-150°C.

Images