CN104817810A - Thermoplastic elastomer material for high-welding-strength refrigerator sealing strips and preparation method thereof - Google Patents

Abstract

The invention relates to a thermoplastic elastomer material for a refrigerator sealing strip with high welding strength and a preparation method thereof. It is composed of the following components by weight: hydrogenated styrene elastomer 10-20 parts, white oil 10-30 parts, polypropylene 1-4 parts, olefin elastomer POE 2-6 parts, metallocene polyethylene 1 -6 parts, 2-5 parts of modified polypropylene alloy, 3-8 parts of mineral powder, 0.4-1.2 parts of stabilizer, first mix the above-mentioned hydrogenated styrene elastomer with white oil, and then mix it with the rest of the materials Mixed, placed in a twin-screw extruder, melt-extruded and granulated. The beneficial effects are as follows: 1. The refrigerator sealing strip product extruded from the thermoplastic elastomer prepared by the present invention has high welding strength. 2. The heat welding time of the refrigerator sealing strip product extruded from the thermoplastic elastomer prepared by the present invention is short. 3. The thermoplastic elastomer material prepared by the present invention can quickly and stably extrude thin-wall refrigerator sealing strips, with high production efficiency and stable product size.

Description

Thermoplastic elastomer material for high welding strength refrigerator sealing strip and preparation method thereof

technical field

The invention relates to the field of polymer modification and processing, in particular to a thermoplastic elastomer material for a refrigerator sealing strip with high welding strength and a preparation method thereof.

Background technique

At present, the refrigerator sealing strip products are still mainly made of PVC materials. For PVC, the advantages are fast processing speed, high welding strength, low scrap rate, and low overall cost for customers. The disadvantages are that it becomes hard plastic at low temperature, poor sealing at low temperature; poor resilience; easy to precipitate pollution; poor environmental friendliness. However, due to the energy saving of home appliances and the requirements of the large refrigerator market, PVC with poor low temperature resistance is really difficult to meet the requirements. Therefore, Haier, Meiling, Xinfei, Hisense and other refrigerator OEMs have invested in the research of thermoplastic elastomer sealing strips, trying to use thermoplastic elastomers instead of traditional ones. PVC, but the welding strength of thermoplastic elastomer products in the refrigerator sealing strip market is poor, it is difficult to meet the customer's requirement that the welding corner pull force is greater than 80N, and the welding corner welding speed is slow and the processing efficiency is low. Although some elastomer manufacturers are in this field After many years of exploration, for example, the Chinese patent document number is CN101983984A, and the patent name is "An Elastomer Material and Preparation Method for Refrigerator Sealing Strip". Its welding tension is 51, which is difficult to meet the market demand. Body materials are difficult to meet the needs of customers for mass production. Therefore, the promotion of thermoplastic elastomers in the refrigerator sealing strip market is limited.

Contents of the invention

The purpose of the present invention is to address the above-mentioned defects in the prior art, to provide a thermoplastic elastomer material for high welding strength refrigerator sealing strips and a preparation method thereof. Thin-walled products, slow welding speed, poor welding strength and other problems make the large-scale application of thermoplastic elastomer materials in the refrigerator sealing industry possible.

A thermoplastic elastomer material for a high welding strength refrigerator sealing strip provided by the invention, it is composed of the following components by weight:

10-20 parts of hydrogenated styrene elastomer, 10-30 parts of white oil, 1-4 parts of polypropylene, 2-6 parts of olefinic elastomer POE, 1-6 parts of metallocene polyethylene, modified polypropylene alloy 2 -5 parts, 3-8 parts of mineral powder, 0.4-1.2 parts of stabilizer, first mix the above-mentioned hydrogenated styrene elastomer with white oil, then mix it with the rest of the materials, put it in a twin-screw extruder, It is made by melt extrusion and granulation.

The above-mentioned white oil is paraffin oil or naphthenic oil, or a mixture of paraffin oil and naphthenic oil with a viscosity of 60-120 mm2 ▪s at 40°C.

The above-mentioned polypropylene has a melt index of 1-3g/10min homopolypropylene or copolymerized polypropylene, or a mixture of homopolypropylene and copolymerized polypropylene.

The above-mentioned olefinic elastomer POE is an ethylene-octene copolymer or an ethylene-butene copolymer, or a mixture of an ethylene-octene copolymer and an ethylene-butene copolymer.

The metallocene polyethylene mentioned above is a low melt index metallocene polyethylene with a melt index of 0.5-1.5 g/10min, or a medium melt index metallocene polyethylene with a melt index of 8-15 g/10min, or a mixture of the two.

The above-mentioned mineral powder is calcium carbonate or talcum powder or Qiangwei powder, or a mixture of two or three of the above.

The above-mentioned stabilizers include primary antioxidants and auxiliary antioxidants, wherein the primary antioxidants are hindered phenol or thioester antioxidants, including but not limited to 1010, one or more compositions in DSTP, wherein, The chemical name of 1010 is tetrakis[β-(3,5-di-tert-butyl 4-hydroxyphenyl) propionate] pentaerythritol, and the chemical name of DSTP is stearyl thiodipropionate;

Auxiliary antioxidants are phosphite or ester antioxidants, including but not limited to one or more combinations of 168 and 618, wherein the chemical name of 168 is tris(2,4-di-tert-butyl phosphite) phenyl) ester, the chemical name of 618 is dioctadecyl pentaerythritol diphosphite.

The preparation method of thermoplastic elastomer material for high welding strength refrigerator sealing strip mentioned in the present invention, it comprises the following steps:

(1) Weigh the raw materials according to the above weight ratio;

(2) Mix the hydrogenated styrene elastomer and white oil in a slow mixer for 20-30 minutes, then mix with other raw material additives for 20-30 minutes, and add the mixed raw materials into the twin-screw extruder, Cooling and granulation after melt extrusion;

(3) The temperature inside the screw barrel is: 170-180℃ in the first zone, 180-190℃ in the second zone, 180-190℃ in the third zone, 180-190℃ in the fourth zone, 180-190℃ in the fifth zone, 180-190℃ in the sixth zone ℃, 180-190 ℃ in the seventh zone, 180-190 ℃ in the eighth zone, 180-190 ℃ in the head, and the speed of the twin-screw extruder is 300-800 rpm.

The beneficial effects of the present invention are: due to the use of hydrogenated polystyrene, the low-temperature sealing problem of refrigerator sealing strips in the actual use process is essentially solved; white oil and polypropylene are added to endow the material with basic processing properties; Olefin-based elastomers can improve the melt properties of the system, improve the extrusion processing efficiency of refrigerator sealing strips, and improve the surface fineness of extruded sealing strips; adding metallocene polyethylene can improve the tensile strength of the material, and at the same time improve the weld angle Tensile force; adding modified polypropylene alloy produced by Shandong Tairuifeng New Material Co., Ltd. can shorten the welding time, improve welding efficiency, and increase welding strength; the invention overcomes the poor welding strength of traditional styrene-based thermoplastic elastomer materials, and the products Solving the problems of slow welding speed and the like, the invention makes it possible for the large-scale application of thermoplastic elastomer materials in the refrigerator sealing industry.

Detailed ways

Example 1: The thermoplastic elastomer material for high welding strength refrigerator sealing strips mentioned in the present invention, weighed 10 parts of hydrogenated styrene elastomer, 10 parts of white oil, 1 part of polypropylene, and 2 parts of olefinic elastomer POE 1 part, 1 part of metallocene polyethylene, 2 parts of modified polypropylene alloy, 3 parts of mineral powder, 0.4 part of stabilizer.

The polypropylene with a melt index of 1-3g/10min is a homopolypropylene, the olefin elastomer POE is an ethylene-octene copolymer, and the metallocene polyethylene has a low melt index with a melt index of 0.5-1.5g/10min. The metal polyethylene and polypropylene alloy modified products are the modified products of Shandong Tairuifeng New Material Co., Ltd., the model is TF45D. This product is a high-flow material, and the melt index is controlled at 60±10g/10min. The powder is calcium carbonate;

Described stabilizer comprises main antioxidant and secondary antioxidant, and wherein main antioxidant is 1010, and chemical name is tetrakis [beta-(3,5-di-tert-butyl 4-hydroxyphenyl) propionic acid] pentaerythritol ester; the auxiliary antioxidant is 168, and the chemical name is tris(2,4-di-tert-butylphenyl) phosphite);

Mix the hydrogenated styrene elastomer and white oil in a slow mixer for 20-30 minutes, then mix with other raw material additives for 20-30 minutes, put the mixed raw materials into the twin-screw extruder, melt extrude Cool and granulate after leaving. Among them, the temperature inside the screw barrel is: 170-180℃ in the first zone, 180-190℃ in the second zone, 180-190℃ in the third zone, 180-190℃ in the fourth zone, 180-190℃ in the fifth zone, 180-190℃ in the sixth zone, and 180-190℃ in the seventh zone. Zone 180-190°C, eight zones 180-190°C, head 180-190°C, twin-screw extruder speed 100-400 rpm.

Embodiment 2: The thermoplastic elastomer material for the high welding strength refrigerator sealing strip mentioned in the present invention, take by weight 20 parts of hydrogenated styrene elastomer, 30 parts of white oil, 4 parts of polypropylene, olefinic elastomer POE 6 6 parts of metallocene polyethylene, 5 parts of modified polypropylene alloy, 8 parts of mineral powder, and 1.2 parts of stabilizer.

Said polypropylene is a copolymerized polypropylene with a melt index of 1-3g/10min, the olefinic elastomer POE is an ethylene-butene copolymer, and metallocene polyethylene is a medium-melt index metallocene with a melt index of 8-15g/10min. The metal polyethylene and polypropylene alloy modified products are the modified products of Shandong Tairuifeng New Material Co., Ltd., the model is TF45D. This product is a high-flow material, and the melt index is controlled at 60±10g/10min. The powder is talcum powder,

The stabilizer includes a main antioxidant and an auxiliary antioxidant, wherein the main antioxidant is DSTP, the chemical name is stearyl thiodipropionate, the auxiliary antioxidant is 618, and the chemical name is double octadecanoate Alkyl pentaerythritol bisphosphite;

Mix the hydrogenated styrene elastomer and white oil in a slow mixer for 20-30 minutes, then mix with other raw material additives for 20-30 minutes, put the mixed raw materials into the twin-screw extruder, melt extrude Cool and granulate after leaving. Among them, the temperature inside the screw barrel is: 170-180℃ in the first zone, 180-190℃ in the second zone, 180-190℃ in the third zone, 180-190℃ in the fourth zone, 180-190℃ in the fifth zone, 180-190℃ in the sixth zone, and 180-190℃ in the seventh zone. Zone 180-190°C, eight zones 180-190°C, head 180-190°C, twin-screw extruder speed 100-400 rpm.

Embodiment 3: The thermoplastic elastomer material for the high welding strength refrigerator sealing strip mentioned in the present invention, take by weight 15 parts of hydrogenated styrene elastomer, 18 parts of white oil, 3 parts of polypropylene, olefin 2 parts of elastomer-like POE, 5 parts of metallocene polyethylene, 5 parts of modified polypropylene alloy, 7 parts of mineral powder, and 1.1 parts of stabilizer.

Said polypropylene is a copolymerized polypropylene with a melt index of 1-3g/10min, the olefinic elastomer POE is an ethylene-butene copolymer, and metallocene polyethylene is a medium-melt index metallocene with a melt index of 8-15g/10min. Metal polyethylene and polypropylene alloy modified products are modified products of Shandong Tairuifeng New Material Co., Ltd. model TF45D. This product is a high-flow material with a melt index controlled at 60±10g/10min; the minerals mentioned The powder is Qiangwei powder;

The stabilizer includes a main antioxidant and an auxiliary antioxidant, wherein the main antioxidant is DSTP, the chemical name is stearyl thiodipropionate, the auxiliary antioxidant is 618, and the chemical name is double octadecanoate Alkyl pentaerythritol bisphosphite;

Mix the hydrogenated styrene elastomer and white oil in a slow mixer for 20-30 minutes, then mix with other raw material additives for 20-30 minutes, put the mixed raw materials into the twin-screw extruder, melt extrude Cool and granulate after leaving. Among them, the temperature inside the screw barrel is: 170-180℃ in the first zone, 180-190℃ in the second zone, 180-190℃ in the third zone, 180-190℃ in the fourth zone, 180-190℃ in the fifth zone, 180-190℃ in the sixth zone, and 180-190℃ in the seventh zone. Zone 180-190°C, eight zones 180-190°C, head 180-190°C, twin-screw extruder speed 100-400 rpm.

It can be seen from the test results that the refrigerator sealing strip made by the invention has high weld fillet strength, high product strength, short welding cycle and high welding efficiency.

Claims (8)

1. A thermoplastic elastomer material for high welding strength refrigerator sealing strip, characterized in that: it is composed of the following components by weight: 10-20 parts of hydrogenated styrene elastomer, 10-30 parts of white oil, 1-4 parts of polypropylene, 2-6 parts of olefinic elastomer POE, 1-6 parts of metallocene polyethylene, modified polypropylene alloy 2 -5 parts, 3-8 parts of mineral powder, 0.4-1.2 parts of stabilizer, first mix the above-mentioned hydrogenated styrene elastomer with white oil, then mix it with the rest of the materials, put it in a twin-screw extruder, It is made by melt extrusion and granulation. 2. The thermoplastic elastomer material for high welding strength refrigerator sealing strip according to claim 1, characterized in that: the white oil is paraffin oil or naphthenic oil with a viscosity of 60-120 mm2 ▪s at 40°C , or a mixture of paraffinic and naphthenic oils. 3. The thermoplastic elastomer material for high welding strength refrigerator sealing strip according to claim 1, characterized in that: said polypropylene has a melt index of 1-3g/10min homopolypropylene or copolymerized polypropylene. 4. The thermoplastic elastomer material for high welding strength refrigerator sealing strip according to claim 1, characterized in that: said olefinic elastomer POE is ethylene-octene copolymer or ethylene-butene copolymer. 5. The thermoplastic elastomer material for high welding strength refrigerator sealing strip according to claim 1, characterized in that: said metallocene polyethylene is a low melt index metallocene polyethylene with a melt index of 0.5-1.5g/10min , or metallocene polyethylene with a melt index of 8-15g/10min. 6. The thermoplastic elastomer material for high welding strength refrigerator sealing strip according to claim 1, characterized in that: said mineral powder is calcium carbonate or talcum powder or strong powder. 7. The thermoplastic elastomer material for high welding strength refrigerator sealing strip according to claim 1, characterized in that: said stabilizer includes a primary antioxidant and an auxiliary antioxidant, wherein the primary antioxidant is hindered phenol or Thioester antioxidants, including but not limited to 1010, one or more compositions in DSTP, wherein the chemical name of 1010 is tetrakis[β-(3,5-di-tert-butyl 4-hydroxyphenyl) Propionic acid] pentaerythritol ester, the chemical name of DSTP is stearyl thiodipropionate; Auxiliary antioxidants are phosphite or ester antioxidants, including but not limited to one or more combinations of 168 and 618, wherein the chemical name of 168 is tris(2,4-di-tert-butyl phosphite) phenyl) ester, the chemical name of 618 is dioctadecyl pentaerythritol diphosphite. 8. A method for preparing a thermoplastic elastomer material for high welding strength refrigerator sealing strips as described in any one of claims 1-7, characterized in that: it comprises the following steps: (1) Weigh the raw materials according to the above weight ratio; (2) Mix the hydrogenated styrene elastomer and white oil in a slow mixer for 20-30 minutes, then mix with other raw material additives for 20-30 minutes, and add the mixed raw materials into the twin-screw extruder, Cooling and granulation after melt extrusion; (3) The temperature inside the screw barrel is: 170-180℃ in the first zone, 180-190℃ in the second zone, 180-190℃ in the third zone, 180-190℃ in the fourth zone, 180-190℃ in the fifth zone, 180-190℃ in the sixth zone ℃, 180-190 ℃ in the seventh zone, 180-190 ℃ in the eighth zone, 180-190 ℃ in the head, and the speed of the twin-screw extruder is 300-800 rpm.