Plastic defoaming agent and preparation method thereof

Abstract

The invention provides a plastic defoaming agent and a preparation method thereof. The defoaming agent is prepared by mixing modified calcium oxide, low-density polyethylene, polypropylene, paraffin, calcium carbonate, ethyl acrylate and a titanate coupling agent in a mixing mill at 120 DEG C for 20 minutes, and finally extruding and granulating by using a twin-screw extruder. A specially prepared composite fiber component is grafted and fixed on the surface of calcium oxide, the contact area between the calcium oxide and a plastic matrix component is increased, dendritic composite fibers play a role of a capillary pipette to enrich surrounding water onto calcium oxide for reaction, the water is eliminated, bubbles and holes are reduced, and the service life of the plastic is prolonged. Meanwhile, the steric hindrance effect can be enhanced by the composite fibers, the agglomeration problem of calcium oxide is avoided, and the dispersion uniformity of calcium oxide and calcium carbonate and the bonding strength between the calcium oxide and calcium carbonate and a plastic matrix are further improved under the lubricating action of paraffin, so that the mechanical property of the plastic is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of defoamers, and particularly relates to a plastic defoamer and a preparation method thereof. Background Art

[0002] Plastics are now ubiquitous in the manufacturing industry. There are all kinds of plastic products. The application of plastics is not only diverse, but also extensive. However, there is a common problem in the application of plastics. Since plastic masterbatch contains water, the water in the plastic will be rapidly vaporized at high temperature due to the increase in temperature during the secondary processing of plastics. However, the water is wrapped by the molten plastic melt and the water vapor cannot escape, resulting in the water vapor remaining in the plastic or forming many holes and bubbles on the surface. Such holes and bubbles will not only affect the appearance and finish of the final product, but also cause the mechanical properties of the plastic products to be greatly reduced, which seriously affects the application of plastics.

[0003] In order to solve this problem, the production adopts the drying method to dry the plastic raw materials to remove moisture, but this method has two defects. First, the drying technology takes a long time. Long-term drying not only requires expensive machines but also consumes a lot of energy; secondly, the drying process cannot completely eliminate moisture. Drying can only remove moisture on the surface of the plastic raw materials, but the moisture hidden inside the plastic cannot be removed. As a result, the drying is not thorough, and the residual moisture still has an adverse effect on the performance of the finished product of the plastic processing machine. Summary of the invention

[0004] In view of the defects of the existing method of eliminating plastic bubbles by drying, which takes a long time and consumes high energy, and cannot eliminate the moisture in the plastic, the present invention provides a plastic defoaming agent and a preparation method thereof, which can be used when drying a plastic substrate to quickly eliminate the moisture in the plastic substrate, thereby avoiding the generation of cavities or bubbles in the plastic body.

[0005] The present invention is achieved through the following technical solutions: A plastic defoamer is prepared from the following components in weight proportion: 50-60 parts of modified calcium oxide, 10-15 parts of low-density polyethylene, 5-10 parts of polypropylene, 10-15 parts of paraffin wax, 5-8 parts of calcium carbonate, 4-6 parts of ethyl acrylate and 1-3 parts of titanate coupling agent.

[0006] As a further improvement of the present invention, the preparation method of the modified calcium oxide is as follows: (1) crushing calcium oxide to a particle size of 100-150 mesh to obtain calcium oxide powder; (2) In parts by weight, first take 40 to 50 parts of the calcium oxide powder obtained in step (1), then add 3 to 5 parts of sodium pyrophosphate and 2 to 4 parts of polyethylene glycol, stir and mix evenly, then add 10 to 15 parts of water, 10 to 15 parts of silane coupling agent, 1 to 3 parts of sodium diisooctyl sulfosuccinate and 8 to 15 parts of composite fiber in sequence, continue stirring for 40 to 45 minutes, and then filter to obtain a filter residue; (3) The filter residue obtained in step (2) is placed in a drying oven and dried to a constant weight to obtain modified calcium oxide.

[0007] As a further improvement of the present invention, the temperature during the stirring treatment in step (2) is 55-65°C.

[0008] As a further improvement of the present invention, the stirring speed in step (2) is 50 to 100 r / min.

[0009] As a further improvement of the present invention, the method for preparing the composite fiber in step (2) comprises the following steps: (1) adding acrylamide, polyvinyl alcohol, hydroxypropyl acrylate and sodium persulfate into a reaction kettle in a mass ratio of (5-10):(1-5):(0.1-0.5):(0.2-0.5), and then stirring and reacting at 60-65° C. for 1-1.5 hours to obtain a reaction material; (2) The reaction material obtained in step (1) is subjected to vacuum degassing and then dry spinning to obtain composite fibers. The length of the obtained composite fibers is 1 to 5 mm.

[0010] At the same time, the present invention provides a method for preparing the plastic defoamer, which comprises first stirring and mixing modified calcium oxide, low-density polyethylene, polypropylene, paraffin, calcium carbonate, ethyl acrylate and a titanate coupling agent, and then feeding the mixture into a mixer and mixing the mixture at 120° C. for 20 minutes, and then extruding and granulating the mixture with a twin-screw extruder to prepare the plastic defoamer.

[0011] Calcium oxide has strong water absorption and can react with water to generate calcium hydroxide, thereby eliminating moisture in plastics. However, calcium oxide has poor dispersion in plastics and is prone to agglomeration, thereby reducing its use effect. At the same time, as a granular filling component, the contact area between calcium oxide and the plastic matrix component is still not high, which still causes the problem that some moisture in the plastic cannot be removed. For this reason, the present invention performs a special modification treatment on calcium oxide, specifically, a specially formulated composite fiber component is grafted and fixed on its surface. The composite fiber has strong water absorption capacity and surface activity. It is grafted on the surface of calcium oxide, thereby increasing the contact area between it and the plastic matrix component. The branch-like composite fiber plays the role of a capillary to enrich the surrounding moisture to the calcium oxide for reaction, thereby eliminating the presence of moisture, thereby reducing the presence of bubbles and holes. At the same time, the composite fiber can enhance the steric hindrance effect, avoid the agglomeration problem of calcium oxide, and the lubricating effect of paraffin further improves the uniformity of the dispersion of calcium oxide and calcium carbonate, as well as the bonding strength with the plastic matrix, thereby improving the mechanical properties of the plastic.

[0012] The beneficial effects of the present invention are as follows: 1. The defoamer prepared by the present invention uses calcium oxide grafted composite fiber components as the main water-absorbing substance, thereby improving the defoamer's ability to adsorb moisture in the plastic matrix and effectively reducing the presence of undesirable structures such as bubbles and holes in the plastic.

[0013] 2. The present invention uses composite fibers and paraffin wax to improve the dispersion performance of calcium oxide and calcium carbonate, making the plastic matrix components more uniform, thereby greatly improving the mechanical properties of the plastic. DETAILED DESCRIPTION

[0014] The present invention will be further described below in conjunction with the embodiments.

[0015] Example 1: A plastic defoamer is made of the following components in weight ratio: 50 parts of modified calcium oxide, 10 parts of low-density polyethylene, 5 parts of polypropylene, 10 parts of paraffin, 5 parts of calcium carbonate, 4 parts of ethyl acrylate, and 1 part of titanate coupling agent.

[0016] The preparation method of the plastic defoamer is to firstly stir and mix modified calcium oxide, low-density polyethylene, polypropylene, paraffin, calcium carbonate, ethyl acrylate and titanate coupling agent uniformly, then put them into a mixer and mix them at 120°C for 20 minutes, and then extrude and granulate them with a twin-screw extruder to prepare the plastic defoamer.

[0017] The preparation method of the modified calcium oxide is as follows: (1) crushing calcium oxide to a particle size of 100 mesh to obtain calcium oxide powder; (2) In parts by weight, 40 parts of the calcium oxide powder obtained in step (1) are first taken, and then 3 parts of sodium pyrophosphate and 2 parts of polyethylene glycol are added and stirred at a speed of 50 r / min to mix evenly, and then 10 parts of water, 10 parts of silane coupling agent, 1 part of sodium diisooctyl sulfosuccinate and 8 parts of composite fiber are added in sequence, and the mixture is stirred at 55° C. for 40 minutes and then filtered to obtain a filter residue; (3) The filter residue obtained in step (2) is placed in a drying oven and dried to a constant weight to obtain modified calcium oxide.

[0018] The preparation method of the composite fiber comprises the following steps: (1) adding acrylamide, polyvinyl alcohol, hydroxypropyl acrylate and sodium persulfate in a mass ratio of 5:1:0.1:0.2 into a reaction kettle, and then stirring and reacting at 60° C. for 1 h to obtain a reaction material; (2) The reaction material obtained in step (1) is subjected to vacuum degassing and then dry spinning to obtain composite fibers. The length of the obtained composite fibers is 2 mm.

[0019] Example 2: A plastic defoamer is made of the following components in weight ratio: 60 parts of modified calcium oxide, 15 parts of low-density polyethylene, 10 parts of polypropylene, 15 parts of paraffin, 8 parts of calcium carbonate, 6 parts of ethyl acrylate, and 3 parts of titanate coupling agent.

[0020] The preparation method of the plastic defoamer is to firstly stir and mix modified calcium oxide, low-density polyethylene, polypropylene, paraffin, calcium carbonate, ethyl acrylate and titanate coupling agent uniformly, then put them into a mixer and mix them at 120°C for 20 minutes, and then extrude and granulate them with a twin-screw extruder to prepare the plastic defoamer.

[0021] The preparation method of the modified calcium oxide is as follows: (1) crushing calcium oxide to a particle size of 150 mesh to obtain calcium oxide powder; (2) In parts by weight, first take 50 parts of the calcium oxide powder obtained in step (1), then add 5 parts of sodium pyrophosphate and 4 parts of polyethylene glycol, stir and mix them evenly at a speed of 100 r / min, then add 15 parts of water, 15 parts of silane coupling agent, 3 parts of sodium diisooctyl sulfosuccinate and 15 parts of composite fiber in sequence, continue stirring at 65° C. for 45 minutes, and then filter to obtain a filter residue; (3) The filter residue obtained in step (2) is placed in a drying oven and dried to a constant weight to obtain modified calcium oxide.

[0022] The preparation method of the composite fiber comprises the following steps: (1) adding acrylamide, polyvinyl alcohol, hydroxypropyl acrylate and sodium persulfate in a mass ratio of 10:5:0.5:0.5 into a reaction kettle, and then stirring and reacting at 65° C. for 1.5 hours to obtain a reaction material; (2) The reaction material obtained in step (1) is subjected to vacuum degassing and then dry spinning to obtain composite fibers. The length of the obtained composite fibers is 5 mm.

[0023] Example 3: A plastic defoamer is made of the following components in weight proportions: 56 parts of modified calcium oxide, 12 parts of low-density polyethylene, 7 parts of polypropylene, 13 parts of paraffin, 6 parts of calcium carbonate, 5 parts of ethyl acrylate, and 2 parts of titanate coupling agent.

[0024] The preparation method of the plastic defoamer is to firstly stir and mix modified calcium oxide, low-density polyethylene, polypropylene, paraffin, calcium carbonate, ethyl acrylate and titanate coupling agent uniformly, then put them into a mixer and mix them at 120°C for 20 minutes, and then extrude and granulate them with a twin-screw extruder to prepare the plastic defoamer.

[0025] The preparation method of the modified calcium oxide is as follows: (1) crushing calcium oxide to a particle size of 120 mesh to obtain calcium oxide powder; (2) In parts by weight, 45 parts of the calcium oxide powder obtained in step (1) are first taken, and then 4 parts of sodium pyrophosphate and 3 parts of polyethylene glycol are added and stirred at a speed of 80 r / min to mix evenly, and then 12 parts of water, 14 parts of silane coupling agent, 2 parts of sodium diisooctyl sulfosuccinate and 10 parts of composite fiber are added in sequence, and the mixture is stirred at 60° C. for 42 minutes and then filtered to obtain a filter residue; (3) The filter residue obtained in step (2) is placed in a drying oven and dried to a constant weight to obtain modified calcium oxide.

[0026] The preparation method of the composite fiber comprises the following steps: (1) adding acrylamide, polyvinyl alcohol, hydroxypropyl acrylate and sodium persulfate in a mass ratio of 8:3:0.4:0.3 into a reaction kettle, and then stirring and reacting at 62° C. for 1.2 h to obtain a reaction material; (2) The reaction material obtained in step (1) is subjected to vacuum degassing and then dry spinning to obtain composite fibers. The length of the obtained composite fibers is 3 mm.

[0027] Application Examples The plastic products prepared by adding the plastic defoamer prepared in Examples 1 to 3 to plastics such as PVC, PP, PS and ABS were compared with the plastic products without adding the plastic defoamer. It was found that the reduction rate of bubbles and holes was more than 90%, as shown in Table 1.

[0028] Table 1:

[0029] It can be seen from the data in Table 1 that the defoamer prepared by the present invention has a good effect of eliminating bubbles or cavities.

[0030] The above embodiments are only exemplary embodiments of the present invention and are not intended to limit the present invention. The protection scope of the present invention is defined by the claims. Those skilled in the art may make various modifications or equivalent substitutions to the present invention within the essence and protection scope of the present invention, and such modifications or equivalent substitutions shall also be deemed to fall within the protection scope of the present invention.

Claims

1. A plastic defoamer, characterized in that: The invention is prepared from the following components in weight proportion: 50-60 parts of modified calcium oxide, 10-15 parts of low-density polyethylene, 5-10 parts of polypropylene, 10-15 parts of paraffin wax, 5-8 parts of calcium carbonate, 4-6 parts of ethyl acrylate and 1-3 parts of titanate coupling agent.

2. The plastic defoamer according to claim 1, characterized in that: The preparation method of the modified calcium oxide is as follows: (1) crushing calcium oxide to a particle size of 100-150 mesh to obtain calcium oxide powder; (2) In parts by weight, first take 40 to 50 parts of the calcium oxide powder obtained in step (1), then add 3 to 5 parts of sodium pyrophosphate and 2 to 4 parts of polyethylene glycol, stir and mix evenly, then add 10 to 15 parts of water, 10 to 15 parts of silane coupling agent, 1 to 3 parts of sodium diisooctyl sulfosuccinate and 8 to 15 parts of composite fiber in sequence, continue stirring for 40 to 45 minutes, and then filter to obtain a filter residue; (3) The filter residue obtained in step (2) is placed in a drying oven and dried to a constant weight to obtain modified calcium oxide.

3. The plastic defoamer according to claim 2, characterized in that: The temperature during the stirring treatment in step (2) is 55-65°C.

4. The plastic defoamer according to claim 2, characterized in that: The stirring speed in step (2) is 50-100 r / min.

5. The plastic defoamer according to claim 2, characterized in that: The method for preparing the composite fiber in step (2) comprises the following steps: (1) adding acrylamide, polyvinyl alcohol, hydroxypropyl acrylate and sodium persulfate into a reaction kettle in a mass ratio of (5-10):(1-5):(0.1-0.5):(0.2-0.5), and then stirring and reacting at 60-65° C. for 1-1.5 hours to obtain a reaction material; (2) The reaction material obtained in step (1) is subjected to vacuum degassing and then dry spinning to obtain composite fibers. The length of the obtained composite fibers is 1 to 5 mm.

6. The method for preparing a plastic defoamer according to any one of claims 1 to 5, characterized in that: The preparation method comprises the following steps: firstly stirring and mixing modified calcium oxide, low-density polyethylene, polypropylene, paraffin, calcium carbonate, ethyl acrylate and titanate coupling agent uniformly, then feeding the mixture into a mixer and mixing them at 120° C. for 20 minutes, and then extruding and granulating the mixture with a twin-screw extruder to prepare the plastic defoamer.

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