High-surface-activity PE with bonding stability of polyurethane and paint and preparation method of high-surface-activity PE

Abstract

The invention relates to the field of high polymer materials, in particular to high-surface-activity PE with bonding stability of polyurethane and paint and a preparation method of the high-surface-activity PE. According to the high-surface-activity PE with bonding stability of polyurethane and paint, provided by the invention, the group donor A, the group donor B and the alkylene polymer are added, and an active group is introduced into a polyethylene chain segment, so that the high-surface-activity PE has high surface activity and can form a covalent bond with an isocyanate group in polyurethane and / or an epoxy group in the paint at normal temperature; according to the high-surface-activity PE, the technical problem that bonding of a non-polar polyethylene material, a polar polyurethane foaming layer and paint is unstable is solved, in addition, the invention further provides a preparation method of the high-surface-activity PE with the bonding stability of polyurethane and paint, the technological process is optimized, the product yield and the finished product rate are high, the application range is wide, and the high practical value is achieved.

Description

Technical Field

[0001] The invention relates to the field of polymer materials, and in particular to high-surface-active PE having both polyurethane and paint bonding stability and a preparation method thereof. Background Art

[0002] Polyethylene (PE) is a type of non-polar polymer, and linear low-density polyethylene (LLDPE) is one of the types of polyethylene. The non-polar polymer PE has low surface energy and poor adhesion, and has extremely poor adhesion to polar materials such as polyurethane and paint.

[0003] At present, methods for improving the surface activity of PE include corona discharge, plasma surface modification, chemical etching, etc. These methods have high requirements on equipment, complex processes, and there is a risk of failure during subsequent use. On March 1, 2019, Chinese patent CN109401031A disclosed a special rotational molding material and its preparation method that can improve the bonding strength between the polyurethane foam layer and the product. By introducing polar groups, the polarity of polyethylene is improved, thereby improving the bonding strength between the polyurethane foam layer and the product. However, this solution still has the limitation that the bonding strength between different areas of the product and the polyurethane foam layer is uneven, and the product fails to achieve stable bonding with the paint. It can be seen that how to achieve stable bonding between PE, polyurethane and paint is still a problem that needs to be solved by those skilled in the art. Summary of the invention

[0004] In order to solve the technical problem of how to achieve stable bonding of PE with polyurethane and paint, the present invention provides a high-surface-active PE with both polyurethane and paint bonding stability, the components of which include: self-made materials, self-made materials and olefin-based polymers; The self-made material comprises a group donor A, LLDPE and an initiator, wherein the group donor A is glycidyloxypropyltrimethoxysilane or vinyltrimethoxysilane oligomer, and the added amount of the group donor A is 4% to 6% by weight; The self-made material includes a group donor B, LLDPE and an initiator, wherein the group donor B is glycidyl methacrylate or ethylene trimethoxysilane, and the added amount of the group donor B is 4% to 6% by weight; The added amount of the olefin-based polymer is 5% to 25% by weight.

[0005] In one embodiment, the amount of LLDPE added to the self-made material or the self-made material is 93.5%~95.5% by weight; the amount of initiator added to the self-made material or the self-made material is 0.5%~0.6% by weight.

[0006] In one embodiment, the components further include: LLDPE and a processing aid; wherein the processing aid includes an antioxidant and a lubricant.

[0007] Furthermore, the processing aid is prepared by mixing antioxidant 1010, antioxidant 168 and lubricant in a weight ratio of 1:2:1.

[0008] In one embodiment, the olefin-based polymer is any one of polyacrylamide, ethylene-acrylate-glycidyl methacrylate, polyacrylic acid, polyvinyl alcohol, and ethylene-acrylic acid copolymer.

[0009] In one embodiment, the LLDPE melt index is 20 g / 10 min.

[0010] In one embodiment, the initiator is any one of 2,5-dimethyl-2,5-bis(tert-butyl peroxide)-3-hexyne, di-tert-butyl peroxide, azobisisobutylcyanide, and diisopropylbenzene peroxide.

[0011] In one embodiment, the homemade material and the homemade material are prepared according to the following steps: Weigh the group donor A or group donor B according to the ratio, and weigh the LLDPE and initiator according to the ratio; Put group donor A or group donor B and LLDPE into a mixer and mix at 10-50 rpm for 2-5 minutes; Then, the initiator is added and mixed at 10-50 rpm for 30-60 s to obtain a premix; The premix is ​​put into a twin-screw extruder, extruded, pelletized, cooled and dried to obtain the self-made material or self-made material; Wherein, the rotation speed of the twin-screw extruder is 400-600 rpm, the process temperature is 180-210°C, and the melt pressure is ≤10 MPa.

[0012] The present invention also provides a method for preparing the high-surface-active PE having both polyurethane and paint adhesion stability as described above, comprising the following steps: Weigh the LLDPE, homemade material, homemade material, olefin-based polymer and processing aid according to the proportion; Put the mixture into a mixer and mix it at 10-50 rpm for 3-5 min to obtain a mixture; The mixed material is put into a twin-screw extruder, extruded, pelletized, cooled and dried to obtain the high-surface-active PE having both polyurethane and paint adhesion stability; Wherein, the rotation speed of the twin-screw extruder is 400-600 rpm, the process temperature is 180-210°C, and the melt pressure is ≤10 MPa.

[0013] The high-surface-active PE with both polyurethane and paint bonding stability provided by the present invention is prepared by introducing active reactive groups such as carboxyl, hydroxyl, amino, epoxy and siloxane into polyethylene segments. The active reactive groups can react chemically with isocyanate groups in polyurethane and / or epoxy groups in paint at room temperature. Microscopically, covalent bonds are formed between the interfaces of the two. Macroscopically, the polyethylene material is activated, so that it can be stably bonded with polyurethane and / or paint.

[0014] The method for preparing high-surface-active PE with both polyurethane and paint bonding stability provided by the present invention has simple process and high production capacity, and is conducive to large-scale production conversion.

[0015] In summary, compared with the prior art, the high-surface-activity PE with both polyurethane and paint adhesion stability provided by the present invention has high surface activity, which can effectively solve the problem of PE, polyurethane and paint adhesion stability. At the same time, the preparation method of the high-surface-activity PE with both polyurethane and paint adhesion stability provided by the present invention has simple process, high production capacity, significant practical value, and obvious advantages. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0017] Figure 1 A physical picture of a thermos barrel test piece made of high-surface-active PE with both polyurethane and paint bonding stability provided in Example 1 of the present invention combined with a polyurethane foam layer; Figure 2 This is a test diagram of a thermos bucket specimen made of high-surface-active PE with both polyurethane and paint adhesion stability and a colored paint cross-cutting test diagram provided in Example 1 of the present invention. DETAILED DESCRIPTION

[0018] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0019] The present invention provides embodiments 1 to 4 for preparing a high-surface-active PE having both polyurethane and paint adhesion stability, wherein the homemade material and the preparation steps of the homemade material are as follows: (1) Preparation of homemade materials 5% of glycidyloxypropyltrimethoxysilane, 94.5% of LLDPE and 0.5% of 2,5-dimethyl-2,5-bis(tert-butylperoxide)-3-hexyne were weighed according to weight percentage; Put the weighed glycidyloxypropyl trimethoxysilane and LLDPE into a mixer and mix at 10-50 rpm for 2-5 min; Then, weighed 2,5-dimethyl-2,5-bis(tert-butyl peroxide)-3-hexyne was added and mixed at 10-50 rpm for 30-60 s to obtain a premix; The premix is ​​put into a twin-screw extruder, extruded, pelletized, cooled and dried to obtain the self-made material.

[0020] (2) Preparation of homemade materials 5% of glycidyl methacrylate, 94.5% of LLDPE and 0.5% of 2,5-dimethyl-2,5-bis(tert-butylperoxide)-3-hexyne were weighed according to weight percentage; Put the weighed glycidyl methacrylate and LLDPE into a mixer and mix at 10-50 rpm for 2-5 minutes; Then, weighed 2,5-dimethyl-2,5-bis(tert-butyl peroxide)-3-hexyne was added and mixed at 10-50 rpm for 30-60 s to obtain a premix; The premix is ​​put into a twin-screw extruder, extruded, pelletized, cooled and dried to obtain the self-made material.

[0021] In an embodiment of the present invention, preferably, the mixer is a low-speed mixer, the mixing speed is 30 rpm, and the mixing time is 2 min and 30 s respectively; the twin-screw extruder speed is 500 rpm, the process temperature is 180~210°C, and the melt pressure is ≤10 MPa.

[0022] In the embodiments of the present invention, specifically, by adding glycidyloxypropyltrimethoxysilane as a group donor A, active groups epoxy and siloxy are provided, and glycidyl methacrylate is added as a group donor B, active groups epoxy and CC double bonds are provided. When in action, the epoxy group has strong reactivity and can undergo a ring-opening reaction with the isocyanate group in the polyurethane, while the siloxy group is easily hydrolyzed to form silanols, so that it can form a stable chemical bond or cross-linked structure during the material surface treatment and modification process, thereby enhancing the bonding force between the materials, and the CC double bond is unsaturated and can undergo a free radical reaction.

[0023] Example 1 Weigh 29.7% LLDPE, 20% homemade material, 30% homemade material, 20% polyacrylamide and 0.3% processing aid according to weight percentage; Put the mixture into a mixer and mix it at 10-50 rpm for 3-5 min to obtain a mixture; The mixed material is put into a twin-screw extruder, extruded, pelletized, cooled and dried to obtain the high-surface-active PE having both polyurethane and paint adhesion stability.

[0024] Example 2 29.7% LLDPE, 20% homemade material, 30% homemade material, 20% ethylene-acrylate-glycidyl methacrylate and 0.3% processing aid were weighed according to weight percentage; Put the mixture into a mixer and mix it at 10-50 rpm for 3-5 min to obtain a mixture; The mixed material is put into a twin-screw extruder, extruded, pelletized, cooled and dried to obtain the high-surface-active PE having both polyurethane and paint adhesion stability.

[0025] Example 3 39.7% LLDPE, 20% homemade material, 30% homemade material, 10% polyacrylic acid and 0.3% processing aid were weighed according to weight percentage; Put the mixture into a mixer and mix it at 10-50 rpm for 3-5 min to obtain a mixture; The mixed material is put into a twin-screw extruder, extruded, pelletized, cooled and dried to obtain the high-surface-active PE having both polyurethane and paint adhesion stability.

[0026] Example 4 49.7% of LLDPE, 20% of homemade material, 30% of homemade material and 0.3% of processing aid were weighed according to weight percentage; Put the mixture into a mixer and mix it at 10-50 rpm for 3-5 min to obtain a mixture; The mixed material is put into a twin-screw extruder, extruded, pelletized, cooled and dried to obtain the high-surface-active PE having both polyurethane and paint adhesion stability.

[0027] The present invention also provides the following comparative example for preparing a PE: Comparative Example 1 The difference between this comparative example and the embodiment of the present invention is that its components do not include homemade materials and olefin-based polymers, and the amount of LLDPE added is adjusted accordingly.

[0028] 69.7% LLDPE, 30% homemade material and 0.3% processing aid were weighed according to weight percentage; Put the mixture into a mixer and mix it at 10-50 rpm for 3-5 min to obtain a mixture; The mixed material is put into a twin-screw extruder, extruded, pelletized, cooled and dried to obtain the PE.

[0029] Comparative Example 2 The difference between this comparative example and the embodiment of the present invention is that its components do not include homemade materials and olefin-based polymers, and the amount of LLDPE added is adjusted accordingly.

[0030] 79.7% LLDPE, 20% homemade material and 0.3% processing aid were weighed according to weight percentage; Put the mixture into a mixer and mix it at 10-50 rpm for 3-5 min to obtain a mixture; The mixed material is put into a twin-screw extruder, extruded, pelletized, cooled and dried to obtain the PE.

[0031] Comparative Example 3 The difference between this comparative example and the embodiment of the present invention is that its components do not include self-made materials, self-made materials and olefin-based polymers, and the addition amount of LLDPE is adjusted accordingly.

[0032] The PE is prepared according to the following steps: Weigh 99.7% of LLDPE and 0.3% of processing aid according to weight percentage; The mixture was put into a low-speed mixer and mixed at 30 rpm for 3 min to obtain a mixture; The mixed material is put into a twin-screw extruder, extruded, pelletized, cooled and dried to obtain the high-surface-active PE having both polyurethane and paint adhesion stability.

[0033] In Examples 1 to 4 of the present invention and Comparative Examples 1 to 3, preferably, the LLDPE is ExxonMobil LL5001.09 or PTT LL8420A.

[0034] In Examples 1 to 4 of the present invention and Comparative Examples 1 to 3, preferably, the mixer is a low-speed mixer, the mixing speed is 30 rpm, and the mixing time is 3 min; the twin-screw extruder speed is 500 rpm, the process temperature is 180 to 210° C., and the melt pressure is ≤10 MPa.

[0035] The high surface active PE with both polyurethane and paint adhesion stability obtained in the above Examples 1 to 4 and the PE obtained in the above Comparative Examples 1 to 3 were respectively made into insulation barrel shells, and the insulation barrel shells were pressure-injected with glue, filled with foamed polyurethane, and cured for 24 hours to obtain insulation barrel products.

[0036] A specimen with a size of 10 mm × 10 mm is cut out from the bottom plane of the insulation barrel product, and the bottom surfaces of two special chucks are respectively bonded to the inner and outer surfaces of the specimen with adhesive or hot melt adhesive, wherein the bottom area of ​​the bottom surface of the special chuck is the same as the area of ​​the specimen. The chuck bonded with the specimen is fixed in the fixture of the universal material testing machine, and the load is evenly applied in the direction perpendicular to the surface of the specimen. The maximum load when the polyurethane foam layer peels off or breaks is recorded, and the bonding strength between the foam layer and the product is calculated according to the bonding strength calculation formula (1):

[0037] σ-bonding strength between the foaming layer and the workpiece, Kpa; P max - Maximum load when the foam layer is peeled off or damaged, N; A-test piece area, 100 mm 2 .

[0038] The performance test results of the bonding strength between the specimen and the polyurethane foam layer, melt index, tensile strength, and notched impact strength are summarized in Table 1: Table 1 Performance test results of the insulation barrel specimens made of PE obtained in Examples 1 to 4 and Comparative Examples 1 to 3

[0039] According to the data in Table 1, after the high-surface-active PE with both polyurethane and paint bonding stability prepared in Example 1 is made into an insulation barrel product, its specimen has excellent mechanical properties and has the highest bonding strength with the polyurethane foam layer. Figure 1 As shown, it effectively overcomes the limitation of uneven bonding strength between different regions of the product and the polyurethane foam layer, showing excellent bonding uniformity. However, after the PE provided in Comparative Example 3 was made into an insulation barrel product, the bonding strength between the specimen and the polyurethane foam layer was low, and no interaction occurred between the foam layer and the substrate.

[0040] Furthermore, the cross-cut test rating of the paint was carried out in accordance with GB / T 9286-2021 Cross-cut test for paints and varnishes. The rating results are listed in Table 2: Table 2 Cross-cut test rating results of the insulation barrel specimens made of PE and the color paint prepared in Examples 1 to 4 and Comparative Examples 1 to 3

[0041] According to the data in Table 2, after the high-surface-active PE with both polyurethane and paint bonding stability prepared in Examples 1 to 3 is made into an insulation barrel product, its test piece has good adhesion to the color paint. Figure 2 The insulation bucket specimen made of high-surface-active PE with both polyurethane and paint bonding stability prepared in Example 1 and the color paint cross-cutting test diagram have smooth edges in the scratched area, no area has fallen off in the small square area, and the edge flatness is relatively complete.

[0042] The present invention introduces active group molecules into polyethylene by adding group donor A, group donor B and olefin-based polymers, so that the surface of the modified polyethylene material has higher surface activity and can stably adhere to and bond with the polyurethane foam layer and paints, thereby optimizing the current process, improving the yield rate, and shortening the process time. The method is applicable to all molding processes, has a wide range of applicability, and has high practical value.

[0043] Although the terms such as bonding, attachment, bonding strength, high surface activity, polarity, group donor A, group donor B, olefin-based polymer, etc. are frequently used in this article, the possibility of using other terms is not excluded. The use of these terms is only for more convenient description and explanation of the essence of the present invention; interpreting them as any additional limitation is contrary to the spirit of the present invention.

[0044] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A high-surface-active PE having both polyurethane and paint bonding stability, characterized in that: Its components include: homemade materials, homemade materials and olefin-based polymers; The self-made material comprises a group donor A, LLDPE and an initiator, wherein the group donor A is glycidyloxypropyltrimethoxysilane or vinyltrimethoxysilane oligomer, and the added amount of the group donor A is 4% to 6% by weight; The self-made material includes a group donor B, LLDPE and an initiator, wherein the group donor B is glycidyl methacrylate or ethylene trimethoxysilane, and the added amount of the group donor B is 4% to 6% by weight; The added amount of the olefin-based polymer is 5% to 25% by weight.

2. The high-surface-active PE having both polyurethane and paint adhesion stability according to claim 1, characterized in that: The amount of LLDPE added to the self-made material or the self-made material is 93.5% to 95.5% by weight; The amount of the initiator added to the self-made material or the self-made material is 0.5% to 0.6% by weight.

3. The high-surface-active PE having both polyurethane and paint adhesion stability according to claim 1, characterized in that: Its components also include: LLDPE and processing aids; Wherein, the processing aids include antioxidants and lubricants.

4. The high-surface-active PE having both polyurethane and paint adhesion stability according to claim 3, characterized in that: The processing aid is prepared by mixing antioxidant 1010, antioxidant 168 and lubricant in a weight ratio of 1:2:

1.

5. The high-surface-active PE having both polyurethane and paint adhesion stability according to claim 1, characterized in that: The olefin-based polymer is any one of polyacrylamide, ethylene-acrylate-glycidyl methacrylate, polyacrylic acid, polyvinyl alcohol, and ethylene-acrylic acid copolymer.

6. The high-surface-active PE having both polyurethane and paint adhesion stability according to claim 1, characterized in that: The LLDPE melt index is 20 g / 10 min.

7. The high-surface-active PE having both polyurethane and paint adhesion stability according to claim 1, characterized in that: The initiator is any one of 2,5-dimethyl-2,5-bis(tert-butyl peroxide)-3-hexyne, di-tert-butyl peroxide, azobisisobutylcyanide, and diisopropylbenzene peroxide.

8. The high-surface-active PE having both polyurethane and paint adhesion stability according to claim 1, characterized in that: The self-made material and the self-made material are prepared according to the following steps: Weigh the group donor A or group donor B according to the ratio, and weigh the LLDPE and initiator according to the ratio; Put group donor A or group donor B and LLDPE into a mixer and mix at 10-50 rpm for 2-5 min; Then, the initiator is added and mixed at 10-50 rpm for 30-60 s to obtain a premix; The premix is ​​put into a twin-screw extruder, extruded, pelletized, cooled and dried to obtain the self-made material or self-made material; Wherein, the rotation speed of the twin-screw extruder is 400-600 rpm, the process temperature is 180-210°C, and the melt pressure is ≤10MPa.

9. The high-surface-active PE having both polyurethane and paint adhesion stability according to claim 1, characterized in that: The component ratios are as follows according to mass percentage: LLDPE 20%~70%, homemade material 5%~25%, homemade material 10%~30%, olefin-based polymer 5%~25%, and processing aid 0.2%~0.5%.

10. A method for preparing high-surface-active PE having both polyurethane and paint adhesion stability as claimed in any one of claims 1 to 9, characterized in that: The following steps are involved: Weigh the LLDPE, homemade material, homemade material, olefin-based polymer and processing aid according to the proportion; Put the mixture into a mixer and mix it at 10-50 rpm for 3-5 min to obtain a mixture; The mixed material is put into a twin-screw extruder, extruded, pelletized, cooled and dried to obtain the high-surface-active PE having both polyurethane and paint adhesion stability; Wherein, the rotation speed of the twin-screw extruder is 400-600 rpm, the process temperature is 180-210°C, and the melt pressure is ≤10MPa.

Images