Sealing material for refrigerator door and preparation method thereof

Abstract

The invention relates to the technical field of sealing materials, and discloses a sealing material for a refrigerator door and a preparation method of the sealing material. The sealing material for the refrigerator door contains CPE (chlorinated polyethylene), PVC (polyvinyl chloride), a plasticizer, a stabilizer, a lubricant and a filler, wherein the plasticizer is a mixture of trans-aconitic acid trioctyl ester and epoxidized soybean oil. The sealing material for the refrigerator door is good in heat stability, small in heat loss, high in plasticizing rate and good in low-temperature flexibility, and meanwhile a plasticizer for preparing the sealing material for the refrigerator door is environmentally friendly and does not cause pollution to the environment; when the sealing material for the refrigerator door is used as a refrigerator door sealing strip, the contact interaction force between the sealing material and a PCM plate is small, the situation that the refrigerator door cannot be opened is not easily caused, and an HIPS plate cannot be corroded.

Description

Technical Field

[0001] The invention relates to the technical field of sealing materials, and in particular to a sealing material for a refrigerator door and a preparation method thereof. Background Art

[0002] In the formula of traditional refrigerator sealing materials, environmentally friendly plasticizer DOTP (dioctyl terephthalate) is often used to replace the traditional non-environmentally friendly plasticizer DOP (dioctyl phthalate) as the main plasticizer to plasticize PVC. However, the door sealing material using DOTP as the main plasticizer has poor thermal stability and large heat loss. It has a large erosion effect on HIPS board (high impact polystyrene) at high temperature. At high temperature, the refrigerator box will have uneven marks and contact with the refrigerator side panel (PCM board). At high temperature, the refrigerator door will not open. Although using TOTM (trioctyl trimellitate) and polyester as plasticizers can solve the above technical problems, they are expensive and have poor plasticization effects. Summary of the invention

[0003] The purpose of the present invention is to overcome the problems existing in the prior art and provide a sealing material for a refrigerator door. The refrigerator door seal prepared by using the sealing material for a refrigerator door has the advantages of small heat loss, small molecular mobility and good low-temperature flexibility.

[0004] In order to achieve the above object, the present invention provides a sealing material for a refrigerator door, which contains CPE, PVC, a plasticizer, a stabilizer, a lubricant and a filler;

[0005] Wherein, the plasticizer is a mixture of trans-trioctyl aconitate and epoxidized soybean oil.

[0006] Preferably, based on the total weight of CPE and PVC being 100 parts by weight, the content of CPE is 50-90 parts by weight, and the content of PVC is 10-50 parts by weight.

[0007] Preferably, based on the total weight of CPE and PVC as 100 parts by weight, the amount of the plasticizer is 10-30 parts by weight, the amount of the stabilizer is 1-5 parts by weight, the amount of the lubricant is 0.2-1 parts by weight, and the amount of the filler is 5-160 parts by weight.

[0008] Preferably, based on the total weight of CPE and PVC being 100 parts by weight, the content of trans-trioctyl aconitate is 5-20 parts by weight, and the content of epoxidized soybean oil is 5-10 parts by weight.

[0009] Preferably, the viscosity of the trans-aconitate trioctyl ester is 220-250 mPa · s.

[0010] Preferably, the stabilizer is one or any combination of two or more of zinc stearate, calcium stearate, hydrotalcite, pentaerythritol, phosphite, β-diketone and 1010 antioxidant.

[0011] Preferably, the lubricant is one or any combination of two or more of stearic acid, paraffin and PE wax.

[0012] Preferably, the filler is calcium carbonate and / or hollow glass microspheres.

[0013] Preferably, the particle size of the filler is 3-30 μm.

[0014] Preferably, the sealing material for refrigerator door further contains an antibacterial and mildew-proof agent, and the amount of the antibacterial and mildew-proof agent is 0.2-1 part by weight based on the total weight of CPE and PVC being 100 parts by weight.

[0015] Preferably, the antibacterial and antifungal agent is one or any combination of two or more of DCOIT, ZPT and OIT.

[0016] A second aspect of the present invention provides a method for preparing the above-mentioned sealing material for refrigerator doors, the method comprising the following steps:

[0017] (1) mixing a lubricant, PVC, a stabilizer, a plasticizer, a filler, and an optional antibacterial and mildew-proof agent to obtain a mixture A;

[0018] (2) mixing the mixture A and CPE to obtain a mixture B;

[0019] (3) kneading the mixture B at 95-140° C. to obtain a mixture C;

[0020] (4) The mixed material C is put into a single screw extruder for extrusion molding, wherein the molding temperature is 100-140°C.

[0021] Preferably, the process of step (1) comprises: adding lubricant, PVC, stabilizer and optional antibacterial and mildew-proof agent into a mixing pot and mixing, then adding plasticizer, and then adding filler, discharging when the temperature of the mixing pot rises to 110-120° C., and obtaining mixture A after cooling.

[0022] Compared with the prior art, the technical solution of the present invention has the following advantages:

[0023] (1) The refrigerator door sealing material of the present invention has good thermal stability, low heat loss, high plasticization rate and good low-temperature flexibility. Meanwhile, the plasticizer used to prepare the refrigerator door sealing material of the present invention is green and environmentally friendly and will not cause pollution to the environment.

[0024] (2) When the refrigerator door sealing material of the present invention is used as a refrigerator door seal, the interaction force with the PCM board is small, which is not likely to cause the refrigerator door to be unable to open, and will not corrode the HIPS board. DETAILED DESCRIPTION

[0025] The specific embodiments of the present invention are described in detail below. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0026] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0027] In one aspect, the present invention provides a sealing material for a refrigerator door, wherein the sealing material for a refrigerator door comprises CPE, PVC, a plasticizer, a stabilizer, a lubricant and a filler;

[0028] Wherein, the plasticizer is a mixture of trans-trioctyl aconitate and epoxidized soybean oil.

[0029] The refrigerator door seal prepared by the refrigerator door sealing material of the present invention has a HIPS board that is not easy to corrode, has good thermal stability and small heat loss, and has good low-temperature flexibility due to its high plasticization rate. When it is used as a refrigerator door seal, the interaction force in contact with the PCM board with high polarity is small, and the refrigerator door will not be unable to be opened. This may be because the polarity of trans-trioctyl aconitate is small and the molecular weight is large, and the steric hindrance of trans-trioctyl aconitate is large, so it can be inserted into the CPE and PVC molecular chains, increase the distance between the molecular chains, and weaken the interaction force between the CPE and PVC molecular chains; at the same time, CPE itself is an elastomer, and when forming a soft elastomer alloy with PVC, the total amount of plasticizer added is much smaller than the amount of plasticizer required for pure PVC, thereby reducing the amount of plasticizer used and thus reducing the amount of molecular migration.

[0030] In the present invention, the "CPE" is chlorinated polyethylene; in a preferred embodiment, the CPE is prepared from high-density polyethylene through a chlorination substitution reaction, wherein the chlorine content of the CPE is 25-30%.

[0031] In the present invention, the “PVC” is polyvinyl chloride; in a preferred embodiment, the K value of the PVC is 70.

[0032] In a preferred embodiment, based on the total weight of CPE and PVC being 100 parts by weight, the content of CPE is 50-90 parts by weight, and the content of PVC is 10-50 parts by weight; preferably, the content of CPE is 60-80 parts by weight, and the content of PVC is 20-40 parts by weight.

[0033] In a preferred embodiment, based on the total weight of CPE and PVC as 100 parts by weight, the amount of the plasticizer is 10-30 parts by weight, the amount of the stabilizer is 1-5 parts by weight, the amount of the lubricant is 0.2-1 parts by weight, and the amount of the filler is 5-160 parts by weight.

[0034] In a more preferred embodiment, based on the total weight of CPE and PVC as 100 parts by weight, the amount of the plasticizer is 15-28 parts by weight, the amount of the stabilizer is 2-4 parts by weight, the amount of the lubricant is 0.5-0.8 parts by weight, the amount of the filler calcium carbonate is 50-80 parts by weight or the amount of the filler hollow glass microspheres is 5-20 parts by weight.

[0035] In a preferred embodiment, based on the total weight of CPE and PVC as 100 parts by weight, the amount of trans-aconitate trioctyl ester is 5-20 parts by weight, and the amount of the epoxidized soybean oil is 5-10 parts by weight; preferably, the amount of trans-aconitate trioctyl ester is 10-20 parts by weight, and the amount of the epoxidized soybean oil is 6-8 parts by weight.

[0036] In a preferred embodiment, the viscosity of the trans-aconitate trioctyl ester is 220-250 mPa. · s.

[0037] In the present invention, the viscosity of trans-trioctyl aconitate refers to the viscosity measured at -5°C.

[0038] In a preferred embodiment, the stabilizer is one or any combination of two or more of zinc stearate, calcium stearate, hydrotalcite, pentaerythritol, phosphite, β-diketone and 1010 antioxidant.

[0039] In a preferred embodiment, the lubricant is one or any combination of two or more of stearic acid, paraffin and PE wax.

[0040] In a preferred embodiment, the filler is calcium carbonate and / or hollow glass microspheres; preferably, the particle size of the filler is 3-30 μm.

[0041] In a preferred embodiment, the hollow glass microspheres are soda lime borosilicate, and the D50 of the soda lime borosilicate is 15-25 μm and the D97 is 37-47 μm.

[0042] According to a preferred embodiment of the present invention, the sealing material for refrigerator doors further contains an antibacterial and mildew-proof agent, and the total weight of CPE and PVC is 100 parts by weight, and the amount of the antibacterial and mildew-proof agent is 0.2-1 parts by weight; preferably, the amount of the antibacterial and mildew-proof agent is 0.5-0.8 parts by weight.

[0043] In a preferred embodiment, the antibacterial and antifungal agent is one or any combination of two or more of DCOIT (4,5-dichloro-N-octyl-4-isothiazoline-3-one), ZPT (2-pyridinethiol-1-oxyzinc) and OIT (2-octyl-4-isothiazoline-3-one).

[0044] A second aspect of the present invention provides a method for preparing the above-mentioned sealing material for refrigerator doors, the method comprising the following steps:

[0045] (1) mixing a lubricant, PVC, a stabilizer, a plasticizer, a filler, and an optional antibacterial and mildew-proof agent to obtain a mixture A;

[0046] (2) mixing the mixture A and CPE to obtain a mixture B;

[0047] (3) kneading the mixture B at 95-140° C. to obtain a mixture C;

[0048] (4) The mixed material C is put into a single screw extruder for extrusion molding, wherein the molding temperature is 100-140°C.

[0049] In a preferred embodiment, the process of step (1) comprises: adding a lubricant, PVC, a stabilizer and an optional antibacterial and mildew-proof agent into a mixing pot and mixing them, then adding a plasticizer, and then adding a filler, and when the temperature of the mixing pot rises to 110-120° C., discharging the material, and obtaining a mixture A after cooling.

[0050] In a preferred embodiment, the process of step (1) is as follows: lubricant, PVC, stabilizer and optional antibacterial and mildew-proof agent are added to a mixing pot, and mixed at a low speed for 1-3 minutes. Then, the plasticizer heated to 50-80°C is poured into the plasticizer storage cylinder and added to the mixing pot at a uniform speed until all the plasticizer is added at 100-105°C. When the temperature reaches 100-110°C, the filler is added. When the temperature of the mixing pot rises to 110-120°C, the material is discharged, and the mixture A is obtained after cooling.

[0051] In a preferred embodiment, in step (1), the low speed rate is 200-500 r / min.

[0052] In a preferred embodiment, in step (1), the temperature of the mixture A is 50-90°C.

[0053] In the present invention, in step (3), there is no special requirement for the mixing equipment, and any equipment conventionally used in the art can be used; preferably, the mixing equipment is a twin-screw extruder or an internal mixer.

[0054] In the present invention, in step (3), there is no special requirement for the mixing time, as long as the mixed material B can be mixed uniformly.

[0055] In the present invention, step (4) also includes hot cutting the material extruded in the single screw extruder.

[0056] The refrigerator door sealing material of the present invention can be used as a refrigerator door seal. The refrigerator door sealing material of the present invention is extruded into a door sealing rubber sleeve by a single-screw door seal extruder according to the requirements of the drawing, and then subjected to two processes of magnetization and welding, so as to finally obtain a refrigerator door seal.

[0057] The refrigerator door seal prepared by the refrigerator door sealing material of the present invention is not easy to corrode the HIPS board, has good thermal stability and small heat loss, and at the same time, due to the high plasticization rate, has good low-temperature flexibility and small interaction force with the PCM board with high polarity, and will not cause the refrigerator door to be unable to open. This may be due to the small amount of trans-aconitate trioctyl ester used in the process of preparing the refrigerator door sealing material. At the same time, since trans-aconitate trioctyl ester has small polarity and large molecular weight, and trans-aconitate trioctyl ester has large steric hindrance, it can be inserted into the CPE and PVC molecular chains, increase the distance between the molecular chains, and weaken the interaction force between the CPE and PVC molecular chains.

[0058] The following examples further illustrate the refrigerator door sealing material and the preparation method thereof. The examples are implemented based on the technical solution of the present invention, and provide detailed implementation methods and specific operation processes, but the protection scope of the present invention is not limited to the following examples.

[0059] The experimental methods in the following examples and comparative examples, unless otherwise specified, are conventional methods in the art. The experimental materials used in the following examples, unless otherwise specified, are all commercially available; among them, the brand of the stabilizer is 9051, purchased from Dalian Kaimisen Technology Co., Ltd.; the lubricant is stearic acid HST, purchased from Qingdao Shengying Innovation Materials Co., Ltd.; the antibacterial and mildew-proof agent is OIT, purchased from British Aike Biochemical Co., Ltd.; the degree of polymerization of PVC is 1300, purchased from Formosa Plastics Group; the chlorine content of CPE is 25%, purchased from Shandong Yaxing Chemical Co., Ltd.

[0060] Example 1

[0061] (1) 0.6 parts by weight of lubricant, 20 parts by weight of PVC, 2 parts by weight of stabilizer and 0.4 parts by weight of antibacterial and mildew-proof agent are added to a mixing pot and mixed at a rate of 300 r / min for 2 min. Then, 24 parts by weight of plasticizer heated to 50° C. are poured into a plasticizer storage cylinder and added to the mixing pot at a uniform speed until all the plasticizer is added at 100° C. When the temperature reaches 105° C., 50 parts by weight of filler calcium carbonate LD800 are added. When the temperature of the mixing pot rises to 110° C., the material is discharged and a mixture A1 at 90° C. is obtained after cooling, wherein the plasticizer is 17 parts by weight of trioctyl trans-aconitate and 7 parts by weight of epoxidized soybean oil;

[0062] (2) Mixing the mixture A1 and 80 parts by weight of CPE to obtain a mixture B1;

[0063] (3) Mixing the mixture B1 with an internal mixer at 120° C. for 10 min to obtain a mixture C1;

[0064] (4) feeding the mixed material C1 into a single screw extruder for extrusion molding at a molding temperature of 120° C., and then hot cutting to obtain a refrigerator door sealing material F1;

[0065] Preparation of refrigerator door seal P1:

[0066] The refrigerator door sealing material F1 is put into a single-screw door sealing extruder to extrude a door sealing rubber sleeve, and then magnetized and welded to obtain a refrigerator door sealing strip P1.

[0067] Example 2

[0068] (1) 0.6 parts by weight of lubricant, 25 parts by weight of PVC, 3 parts by weight of stabilizer and 0.5 parts by weight of antibacterial and mildew-proof agent are added to a mixing pot and mixed at a rate of 300 r / min for 2 min. Then, 26 parts by weight of plasticizer heated to 50° C. are poured into a plasticizer storage cylinder and added to the mixing pot at a uniform speed until all the plasticizer is added at 100° C. When the temperature reaches 105° C., 60 parts by weight of filler calcium carbonate LD800 are added. When the temperature of the mixing pot rises to 110° C., the material is discharged. After cooling, a mixture A2 at 90° C. is obtained, wherein the plasticizer is 20 parts by weight of trioctyl trans-aconitate and 6 parts by weight of epoxidized soybean oil;

[0069] (2) Mixing the mixture A2 and 75 parts by weight of CPE to obtain a mixture B2;

[0070] (3) Mixing the mixture B2 with an internal mixer at 130° C. for 13 min to obtain a mixture C2;

[0071] (4) feeding the mixed material C2 into a single screw extruder for extrusion molding at a molding temperature of 130° C., and then hot cutting to obtain a refrigerator door sealing material F2;

[0072] Preparation of refrigerator door seal P2:

[0073] The refrigerator door sealing material F2 is put into a single-screw door sealing extruder to extrude a door sealing rubber sleeve, and then magnetized and welded to obtain a refrigerator door sealing strip P2.

[0074] Example 3

[0075] (1) 0.7 parts by weight of lubricant, 30 parts by weight of PVC, 3 parts by weight of stabilizer and 0.6 parts by weight of antibacterial and mildew-proof agent are added to a mixing pot and mixed at a rate of 300 r / min for 2 min. Then, 27 parts by weight of plasticizer heated to 50° C. are poured into a plasticizer storage cylinder and added to the mixing pot at a uniform speed until all the plasticizer is added at 100° C. When the temperature reaches 105° C., 70 parts by weight of filler calcium carbonate LD800 are added. When the temperature of the mixing pot rises to 110° C., the material is discharged and cooled to obtain a mixture A3 at 90° C., wherein the plasticizer is 20 parts by weight of trioctyl trans-aconitate and 7 parts by weight of epoxidized soybean oil;

[0076] (2) Mixing the mixture A3 and 70 parts by weight of CPE to obtain a mixture B3;

[0077] (3) Mixing the mixture B3 with an internal mixer at 130° C. for 14 min to obtain a mixture C3;

[0078] (4) feeding the mixed material C3 into a single screw extruder for extrusion molding at a molding temperature of 140° C., and then hot cutting to obtain a refrigerator door sealing material F3;

[0079] Preparation of refrigerator door seal P3:

[0080] The refrigerator door sealing material F3 is put into a single-screw door sealing extruder to extrude a door sealing rubber sleeve, and then magnetized and welded to obtain a refrigerator door sealing strip P3.

[0081] Example 4

[0082] (1) 0.8 parts by weight of lubricant, 40 parts by weight of PVC, 4 parts by weight of stabilizer and 0.8 parts by weight of antibacterial and mildew-proof agent are added to a mixing pot and mixed at a rate of 300 r / min for 2 min. Then, 28 parts by weight of plasticizer heated to 50° C. are poured into a plasticizer storage cylinder and added to the mixing pot at a uniform speed until all the plasticizer is added at 100° C. When the temperature reaches 105° C., 20 parts by weight of filler soda lime borosilicate are added. When the temperature of the mixing pot rises to 110° C., the material is discharged and cooled to obtain a mixture A4 at 90° C., wherein the plasticizer is 20 parts by weight of trioctyl trans-aconitate and 4 parts by weight of epoxidized soybean oil;

[0083] (2) Mixing the mixture A4 and 60 parts by weight of CPE to obtain a mixture B4;

[0084] (3) kneading the mixture B4 at 135° C. for 15 min using a twin-screw extruder to obtain a mixture C4;

[0085] (4) feeding the mixed material C4 into a single screw extruder for extrusion molding at a molding temperature of 120° C., and then hot cutting to obtain a refrigerator door sealing material F4;

[0086] Preparation of refrigerator door seal P4:

[0087] The refrigerator door sealing material F4 is put into a single-screw door sealing extruder to extrude a door sealing rubber sleeve, and then magnetized and welded to obtain a refrigerator door sealing strip P4.

[0088] Example 5

[0089] (1) 0.6 parts by weight of lubricant, 60 parts by weight of PVC, 2 parts by weight of stabilizer and 0.4 parts by weight of antibacterial and mildew-proof agent were added to a mixing pot and mixed at a rate of 300 r / min for 2 min. Then, 24 parts by weight of plasticizer heated to 50° C. were poured into a plasticizer storage cylinder and added to the mixing pot at a uniform speed until all the plasticizer was added at 100° C. When the temperature reached 105° C., 50 parts by weight of filler calcium carbonate LD800 were added. When the temperature of the mixing pot rose to 110° C., the mixture was discharged and cooled to obtain a mixture A5 at 90° C., wherein the plasticizer was 17 parts by weight of trioctyl trans-aconitate and 7 parts by weight of epoxidized soybean oil;

[0090] (2) Mixing the mixture A5 and 40 parts by weight of CPE to obtain a mixture B5;

[0091] (3) Mixing the mixture B5 with an internal mixer at 120° C. for 10 min to obtain a mixture C5;

[0092] (4) feeding the mixed material C5 into a single screw extruder for extrusion molding at a molding temperature of 120° C., and then hot cutting to obtain a refrigerator door sealing material F5;

[0093] Preparation of refrigerator door seal P5:

[0094] The refrigerator door sealing material F5 is put into a single-screw door sealing extruder to extrude a door sealing rubber sleeve, and then magnetized and welded to obtain a refrigerator door sealing strip P5.

[0095] Example 6

[0096] (1) 0.6 parts by weight of lubricant, 20 parts by weight of PVC, 2 parts by weight of stabilizer and 0.4 parts by weight of antibacterial and mildew-proof agent are added to a mixing pot and mixed at a rate of 300 r / min for 2 min. Then, 8 parts by weight of plasticizer heated to 50° C. are poured into a plasticizer storage cylinder and added to the mixing pot at a uniform speed until all the plasticizer is added at 100° C. When the temperature reaches 105° C., 50 parts by weight of filler calcium carbonate LD800 are added. When the temperature of the mixing pot rises to 110° C., the material is discharged and cooled to obtain a mixture A6 at 90° C., wherein the plasticizer is 4 parts by weight of trioctyl trans-aconitate and 4 parts by weight of epoxidized soybean oil;

[0097] (2) Mixing the mixture A6 and 80 parts by weight of CPE to obtain a mixture B6;

[0098] (3) Mixing the mixture B6 with an internal mixer at 120° C. for 10 min to obtain a mixture C6;

[0099] (4) feeding the mixed material C6 into a single screw extruder for extrusion molding at a molding temperature of 120° C., and then hot cutting to obtain a refrigerator door sealing material F6;

[0100] Preparation of refrigerator door seal P6:

[0101] The refrigerator door sealing material F6 is put into a single-screw door sealing extruder to extrude a door sealing rubber sleeve, and then magnetized and welded to obtain a refrigerator door sealing strip P6.

[0102] Comparative Example 1

[0103] The method of Example 1 was followed, except that the same weight of DOTP was used to replace trans-trioctyl aconitate, and the same weight of PVC was used to replace CPE.

[0104] Comparative Example 2

[0105] The method of Example 1 is followed, except that the PVC is replaced by CPE of the same weight.

[0106] Comparative Example 3

[0107] The method was implemented in the same manner as in Example 1, except that the same weight of TOTM was used to replace trans-trioctyl aconitate.

[0108] Test Case

[0109] The performance tests were performed on the refrigerator door seals prepared in the examples and comparative examples:

[0110] (1) The hardness of the refrigerator door seal was tested according to the standard of GB / T 2411-2008, with the unit being A. The test results are shown in Table 1;

[0111] (2) The heat loss of the refrigerator door seal was tested at 120°C for 120 hours. The unit is %, and the test results are shown in Table 1.

[0112] (3) At -20°C, DMA was used to test the storage modulus of the refrigerator door seal, in MPa. The test results are shown in Table 1.

[0113] (4) The density of the refrigerator door seal is tested according to the immersion method standard GB / T 1033.1-2008, and the unit is g / cm 3 ,The test results are shown in Table 1;

[0114] (5) The test method for HIPS board migration is as follows: prepare a 2mm thick vulcanized sheet of the sample to be tested, cut it into a size of 50mm*10mm*2mm (size deviation plus or minus 0.3mm), the surface is free of pollution, and the edges are evenly cut. Place the test piece in a dryer for 24 hours and weigh it, recorded as M1; then clamp it between two standard HIPS boards (or HIPS boards) to form a test sample. Place the test sample horizontally in an oven, and then apply a 1.1kg weight or iron block (equivalent to 0.22kg / cm 2 The test piece was placed in an oven at 70°C ± 2°C for 72 hours and then taken out and separated from the standard plate. The test piece was placed in a dryer and cooled to room temperature, which was recorded as M2. The molecular mobility was calculated according to the formula |M1-M2| / M1*100%. Two groups were tested in total, and the arithmetic mean was taken as the final result in mg. The test results are shown in Table 1.

[0115] (6) The adhesion strength between the material of the present invention and the PCM board was tested as follows: the refrigerator door seal was cut into 100 mm long specimens, and the magnetic strip was naturally adsorbed on the front of the PCM board to obtain the test sample, and the test sample was placed in an oven at 70°C, and a pressure of 1 kg was applied to the test sample. After 24 hours, the test sample was taken out and left to stand at room temperature. The refrigerator door seal was evenly pulled down from the front of the PCM board using a tensile gauge, and the peak value (maximum value) of the tensile force displayed on the tensile gauge was recorded, which was the adhesion strength between the material of the present invention and the PCM board, in N. The test results are shown in Table 1.

[0116] (7) The elongation at break of the refrigerator door seal was tested according to the standard of GB / T 1040.1-2006, and the unit is %, and the test results are shown in Table 1;

[0117] (8) The tensile strength of the refrigerator door seal was tested according to the standard of GB / T 1040.3-2006, with the unit of MPa. The test results are shown in Table 1;

[0118] Table 1

[0119]

[0120]

[0121] It can be seen from the results in Table 1 that the refrigerator door seal prepared by the refrigerator door sealing material of the present invention has moderate density and hardness, small heat loss at high temperature, good low-temperature flexibility, small migration of HIPS board, small adhesion to PCM board, and convenient opening and closing of the refrigerator door. Compared with the traditional refrigerator door sealing material prepared by using TOTM as a plasticizer, its performance is equivalent, but the plasticizer of the present invention is more environmentally friendly.

[0122] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.

Claims

1. A sealing material for a refrigerator door, characterized in that: The refrigerator door sealing material contains CPE, PVC, plasticizer, stabilizer, lubricant and filler; Wherein, the plasticizer is a mixture of trans-trioctyl aconitate and epoxidized soybean oil.

2. The sealing material for refrigerator door according to claim 1, characterized in that: Taking the total weight of CPE and PVC as 100 parts by weight, the content of CPE is 50-90 parts by weight, and the content of PVC is 10-50 parts by weight.

3. The sealing material for refrigerator door according to claim 1 or 2, characterized in that: Taking the total weight of CPE and PVC as 100 parts by weight, the amount of the plasticizer is 10-30 parts by weight, the amount of the stabilizer is 1-5 parts by weight, the amount of the lubricant is 0.2-1 parts by weight, and the amount of the filler is 5-160 parts by weight; Preferably, based on the total weight of CPE and PVC being 100 parts by weight, the amount of trans-aconitate trioctyl ester is 5-20 parts by weight, and the amount of epoxidized soybean oil is 5-10 parts by weight.

4. The sealing material for refrigerator door according to any one of claims 1 to 3, characterized in that: The viscosity of the trans-aconitate trioctyl ester is 220-250 mPa · s.

5. The sealing material for refrigerator door according to any one of claims 1 to 3, characterized in that: The stabilizer is one or any combination of two or more of zinc stearate, calcium stearate, hydrotalcite, pentaerythritol, phosphite, beta-diketone and 1010 antioxidant.

6. The sealing material for refrigerator door according to any one of claims 1 to 3, characterized in that: The lubricant is one or any combination of two or more of stearic acid, paraffin and PE wax.

7. The sealing material for refrigerator door according to any one of claims 1 to 3, characterized in that: The filler is calcium carbonate and / or hollow glass microspheres; Preferably, the D50 particle size of the filler is 3-30 μm.

8. The sealing material for refrigerator door according to any one of claims 1 to 7, characterized in that: The refrigerator door sealing material further contains an antibacterial and mildew-proof agent, wherein the total weight of CPE and PVC is 100 parts by weight, and the amount of the antibacterial and mildew-proof agent is 0.2-1 parts by weight; Preferably, the antibacterial and antifungal agent is one or any combination of two or more of DCOIT, ZPT and OIT.

9. A method for preparing the sealing material for refrigerator door according to any one of claims 1 to 8, characterized in that: The method comprises the following steps: (1) mixing a lubricant, PVC, a stabilizer, a plasticizer, a filler, and an optional antibacterial and mildew-proof agent to obtain a mixture A; (2) mixing the mixture A and CPE to obtain a mixture B; (3) kneading the mixture B at 95-140° C. to obtain a mixture C; (4) The mixed material C is put into a single screw extruder for extrusion molding, wherein the molding temperature is 100-140°C.

10. The method according to claim 9, characterized in that The process of step (1) comprises: adding lubricant, PVC, stabilizer and optional antibacterial and mildew-proof agent into a mixing pot and mixing, then adding plasticizer and then adding filler, discharging when the temperature of the mixing pot rises to 110-120° C., and obtaining mixed material A after cooling.

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