A polypropylene composition having good adhesion with silicone adhesive and preparation method thereof

Abstract

The present invention relates to the field of polypropylene material preparation, and specifically discloses a polypropylene composition having good adhesion with silicone adhesive and a preparation method thereof, wherein the polypropylene composition comprises the following raw materials in parts by weight: 40 to 80 parts of polypropylene, 20 to 45 parts of modified porous silicon powder, 0.5 to 5 parts of lubricant, and 0.5 to 2 parts of other auxiliary agents. The polypropylene composition disclosed by the present invention has good adhesion performance, high adhesion strength with silicone adhesive, and good durability.

Description

Technical Field

[0001] The invention relates to the field of polypropylene material preparation, and specifically discloses a polypropylene composition having good adhesion with silicone adhesive and a preparation method thereof. Background Art

[0002] As one of the main raw materials for the automotive industry, plastic materials have the advantages of excellent material properties, good economy and the possibility of large-scale supply. Polypropylene (PP) materials are widely used in home appliances, automobiles, electronic appliances, building materials and packaging industries due to their low density, low odor, low price, good formability, excellent chemical resistance, good mechanical properties and environmental friendliness, becoming one of the most promising polymer materials.

[0003] Glue is often needed for sealing when polymer materials are bonded. Silicone sealant has better resistance to UV radiation, aging and weathering than other organic glues. Polypropylene is a non-polar polymer material with low surface tension, while silicone sealant is a polar compound with poor bonding performance. In order to make it widely used in home appliances, automobiles, packaging and other fields, flame treatment, plasma treatment, corona treatment and other secondary treatment processes are often required to improve the surface energy of polypropylene materials, thereby improving its surface bonding performance. However, the above secondary treatment processes are complex and costly.

[0004] The invention patent with publication number CN112724537A discloses a modified polypropylene composite material with high bonding performance, its preparation method and application, comprising the following raw materials and their weight parts: 40-80 parts of polypropylene, 20-50 parts of talcum powder, 1-10 parts of rubber toughening agent, 0.5-1.5 parts of compatibilizer, 0.1-1.5 parts of antioxidant, 0.1-3 parts of coupling agent, 0.1-1.5 parts of lubricant and 0.1-2 parts of polar additive. The polar additive is diethanolamine with a long carbon chain structure, and the long carbon chain structure is a carbon chain structure with more than 10 carbon atoms. This invention patent uses a polar additive with a higher molecular weight to alleviate its precipitation, but due to its poor compatibility with polypropylene, it has limited effect on improving the bonding performance of the polypropylene system, which may affect the bonding effect between the polypropylene composite material and the glue.

[0005] At the same time, preparing modified polypropylene materials by simply adding polar additives and blending with polypropylene often affects the stability and bonding durability of the material.

[0006] In view of this, it is particularly important to disclose a polypropylene composition that has good adhesion with silicone adhesive. Summary of the invention

[0007] In view of the defects of the prior art, the present invention discloses a polypropylene composition having good bonding with silicone adhesive and a preparation method thereof. The polypropylene composition disclosed in the present invention has good bonding performance, high bonding strength with silicone adhesive, and good durability.

[0008] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0009] On one hand, the present invention provides a polypropylene composition having good adhesion with silicone adhesive, wherein the polypropylene composition comprises the following raw materials in parts by weight: 40-80 parts of polypropylene, 20-45 parts of modified porous silicon powder, 0.5-5 parts of lubricant and 0.5-2 parts of other additives.

[0010] In some embodiments of the present invention, the polypropylene is a copolymerized polypropylene.

[0011] Preferably, the copolymerized polypropylene has a melt index of 10 to 15 g / 10 min at 230° C. and 2.16 kg.

[0012] Further preferably, the copolymerized polypropylene has a melt index of 12 g / 10 min at 230° C. and 2.16 kg.

[0013] In some embodiments of the present invention, the preparation steps of the modified porous silicon powder are as follows:

[0014] The porous silicon powder and the emulsifier are mixed and added into water. After ultrasonic dispersion, the temperature is raised to 60-80° C., an amino-containing silane coupling agent is added, and the mixture is stirred and reacted for 1-4 hours. The temperature is further raised to 85-90° C., a long carbon chain olefin monomer, an acrylic acid monomer and an initiator are added, and the mixture is reacted for 1-3 hours. After demulsification, filtration, washing and drying, the modified porous silicon powder is obtained.

[0015] In some embodiments of the present invention, the porous silicon powder is nano-scale porous silicon powder.

[0016] Preferably, the average particle size of the nano-scale porous silicon powder is 6 to 10 nm.

[0017] In some embodiments of the present invention, the amino-containing silane coupling agent is γ-aminopropyltriethoxysilane.

[0018] Preferably, the long carbon chain olefin monomer is hexene.

[0019] In some embodiments of the present invention, the mass ratio of the porous silicon powder, the amino-containing silane coupling agent, the long carbon chain olefin monomer and the acrylic acid monomer is 1:(4-6):(2-4):(3-6).

[0020] Preferably, the mass ratio of the porous silicon powder, the amino-containing silane coupling agent, the long carbon chain olefin monomer and the acrylic acid monomer is 1:5:3:4.5.

[0021] In the prior art, in addition to using secondary treatment processes such as flame treatment, plasma treatment, and corona treatment to increase the surface energy of polypropylene materials and thus improve their bonding properties, polar substances are often added to form polypropylene compositions to utilize their surface polarity to improve the adhesion between polypropylene and glue.

[0022] The present invention prepares modified porous silicon powder by introducing amino-containing silane coupling agent for pre-modification, and then adding long carbon chain olefin monomer and acrylic acid monomer for in-situ polymerization. While ensuring the porous structure of silicon powder, a uniformly coated polymer layer is formed. When the modified silicon powder is added to a polypropylene composition, the surface energy is increased to modify the bonding performance while effectively blocking the precipitation of polar substances, solving the problem that the existing polar additives are easy to precipitate and destroy the bonding performance. When the polypropylene composition is bonded with silicone glue, the molecular chains on the surface of the modified porous silicon powder may form high bonding force through penetration and chemical entanglement, improve the adhesion between the polypropylene compound and the glue, and increase the bonding strength. At the same time, the applicant also found that the modified porous silicon powder may form a network structure in which the molecular chains penetrate each other in the system, thereby ensuring the stability of the polypropylene composition.

[0023] In some embodiments of the present invention, the lubricant is modified oxidized polyethylene wax.

[0024] In some embodiments of the present invention, the preparation steps of the modified oxidized polyethylene wax are as follows:

[0025] The oxidized polyethylene wax and the organic solvent are mixed, triethanolamine and p-toluenesulfonic acid are added, the temperature is raised to 100-120° C., the mixture is stirred for reaction for 1-2 hours, and the modified oxidized polyethylene wax is obtained by drying.

[0026] In some embodiments of the present invention, the mass ratio of the oxidized polyethylene wax to triethanolamine is 10:(0.1-0.3).

[0027] Preferably, the mass ratio of the oxidized polyethylene wax to triethanolamine and p-toluenesulfonic acid is 10:0.2.

[0028] Preferably, the added amount of p-toluenesulfonic acid is 5-10% of the mass of the oxidized polyethylene wax.

[0029] Further preferably, the added amount of p-toluenesulfonic acid is 7% of the mass of the oxidized polyethylene wax.

[0030] In the prior art, lubricant oxidized polyethylene wax can be added to further improve the dispersion compatibility of the modified filler in the system. However, due to the decrease in stability of the oxidized polyethylene wax, the surface state of the polypropylene composition will be further deteriorated to a certain extent, which will be detrimental to the long-term performance of the polypropylene composition after bonding with glue. In view of this, the present invention further improves the external lubricity and internal lubricity of the oxidized polyethylene wax by preparing a modified oxidized polyethylene wax, and its compatibility in the polypropylene composition system is further improved, and it is easier to penetrate into the system, improve the appearance state, and improve the bonding stability of the polypropylene composition.

[0031] In some embodiments of the present invention, the other auxiliary agent is one or more of an antioxidant, an ultraviolet absorber and an antistatic agent.

[0032] Preferably, the other auxiliary agent is a mixture of an antioxidant, an ultraviolet absorber and an antistatic agent.

[0033] Preferably, in parts by weight, the antioxidant is 0.2 to 0.8 parts, the ultraviolet absorber is 0.1 to 0.5 parts, and the antistatic agent is 0.2 to 0.7 parts.

[0034] Preferably, the antioxidant is antioxidant 1010, the ultraviolet absorber is ultraviolet absorber UV327, and the antistatic agent is antistatic agent 163.

[0035] On the other hand, the present invention also provides a method for preparing a polypropylene composition that has good adhesion to silicone adhesive, comprising the following steps: mixing polypropylene, modified porous silicon powder, a lubricant and other additives, and granulating the mixture by melt extrusion at 180-220° C. through a twin-screw extruder to obtain the polypropylene composition.

[0036] Compared with the prior art, the present invention has the following beneficial effects:

[0037] (1) The polypropylene composition disclosed in the present invention is added with modified porous silicon powder and lubricant modified oxidized polyethylene wax, has good bonding performance, high bonding strength with silicone glue, and good durability.

[0038] (2) The present invention prepares modified porous silicon powder by selectively selecting nano-scale porous silicon powder, introducing an amino-containing silane coupling agent for pre-modification, and then adding a long carbon chain olefin monomer and an acrylic acid monomer for in-situ polymerization. This method increases the surface energy and improves the bonding performance while effectively blocking the precipitation of polar substances, thereby solving the problem that the existing polar additives are easy to precipitate and destroy the bonding performance.

[0039] (3) The present invention also forms a network structure in which molecular chains penetrate each other by mixing the modified porous silicon powder with other components of the polypropylene composition system, thereby ensuring the stability of the polypropylene composition.

[0040] (4) The present invention prepares a modified oxidized polyethylene wax, thereby further improving the external lubricity and internal lubricity of the oxidized polyethylene wax, further improving its compatibility in the polypropylene composition system, making it easier to penetrate into the system, improving the appearance, and at the same time improving the bonding stability of the polypropylene composition. DETAILED DESCRIPTION

[0041] The present invention will be described below in conjunction with specific embodiments. It should be noted that the following embodiments are examples of the present invention and are only used to illustrate the present invention, but not to limit the present invention. Other combinations and various modifications within the concept of the present invention may be performed without departing from the spirit or scope of the present invention.

[0042] Unless otherwise specified, the reagents used below can be easily obtained from commercial companies, and the oxidized polyethylene wax used was purchased from Henan Tianchou Chemical Products Co., Ltd.

[0043] Unless otherwise specified, the porous silicon powders used in the following preparation examples and embodiments are all nano-scale porous silicon powders with an average particle size of 8 nm.

[0044] Preparation Example 1

[0045] The preparation steps of modified porous silicon powder are as follows:

[0046] 10 g of porous silicon powder and 20 g of sodium dodecyl sulfate were mixed and added into 100 mL of water. After ultrasonic dispersion, the temperature was raised to 70°C, 5 g of γ-aminopropyltriethoxysilane was added, and the mixture was stirred for reaction for 2 h. The temperature was further raised to 90°C, 3 g of hexene, 4.5 g of ethyl acrylate and 0.02 g of diisopropyl peroxide were added, and the mixture was reacted for 2 h. After demulsification, filtration, washing and drying to constant weight, the modified porous silicon powder was obtained.

[0047] Preparation Example 2

[0048] The preparation steps of the modified porous silicon powder are the same as those in Preparation Example 1, except that the amount of γ-aminopropyltriethoxysilane added is 7 g.

[0049] Preparation Example 3

[0050] The preparation steps of the modified porous silicon powder are the same as those in Preparation Example 1, except that the amount of hexene added is 5 g.

[0051] Preparation Example 4

[0052] The preparation steps of the modified porous silicon powder are the same as those in Preparation Example 1, except that the amount of ethyl acrylate added is 6.5 g.

[0053] Preparation Example 5

[0054] The preparation steps of the modified porous silicon powder are the same as those in Preparation Example 1, except that the average particle size of the porous silicon powder is 15 nm.

[0055] Preparation Example 6

[0056] The preparation steps of modified oxidized polyethylene wax are as follows:

[0057] Mix 10 g of oxidized polyethylene wax and 200 mL of toluene, add 0.2 g of triethanolamine and 0.7 g of p-toluenesulfonic acid, heat to 110°C, stir and react for 1.5 hours, and dry to obtain modified oxidized polyethylene wax.

[0058] Preparation Example 7

[0059] The preparation steps of the modified oxidized polyethylene wax are the same as those of Preparation Example 6, except that the amount of triethanolamine added is 0.4 g.

[0060] Unless otherwise specified, the polypropylene used below is copolymer polypropylene with a melt index of 12 g / 10 min (230°C, 2.16 kg), the antioxidant is antioxidant 1010, the UV absorber is UV327, and the antistatic agent is antistatic agent 163.

[0061] Example 1

[0062] A polypropylene composition with good adhesion to silicone adhesive comprises the following raw materials in parts by weight: 60 parts of polypropylene, 32.5 parts of modified porous silicon powder, 2.75 parts of lubricant, 0.5 parts of antioxidant, 0.3 parts of ultraviolet absorber and 0.45 parts of antistatic agent.

[0063] The preparation method of the polypropylene composition with good adhesion to silicone adhesive in this embodiment comprises the following steps: mixing polypropylene, modified porous silicon powder, lubricant, antioxidant, ultraviolet absorber and antistatic agent, and granulating them by melt extrusion at 200° C. through a twin-screw extruder to obtain a polypropylene composition.

[0064] The modified porous silicon powder used is obtained from Preparation Example 1, and the lubricant used is the modified oxidized polyethylene wax obtained from Preparation Example 6.

[0065] Example 2

[0066] A polypropylene composition with good adhesion to silicone adhesive comprises the following raw materials in parts by weight: 40 parts of polypropylene, 20 parts of modified porous silicon powder, 0.5 parts of lubricant, 0.2 parts of antioxidant, 0.1 parts of ultraviolet absorber and 0.2 parts of antistatic agent.

[0067] The preparation method of the polypropylene composition with good adhesion to silicone adhesive in this embodiment comprises the following steps: polypropylene, modified porous silicon powder, lubricant, antioxidant, ultraviolet absorber and antistatic agent are mixed, and the mixture is melt-extruded and granulated at 180° C. through a twin-screw extruder to obtain a polypropylene composition.

[0068] The modified porous silicon powder used is obtained from Preparation Example 1, and the lubricant used is the modified oxidized polyethylene wax obtained from Preparation Example 6.

[0069] Example 3

[0070] A polypropylene composition having good adhesion with silicone adhesive comprises the following raw materials in parts by weight: 80 parts of polypropylene, 45 parts of modified porous silicon powder, 5 parts of lubricant, 0.8 parts of antioxidant, 0.5 parts of ultraviolet absorber and 0.7 parts of antistatic agent.

[0071] The preparation method of the polypropylene composition with good adhesion to silicone adhesive in this embodiment comprises the following steps: mixing polypropylene, modified porous silicon powder, lubricant, antioxidant, ultraviolet absorber and antistatic agent, and granulating them by melt extrusion at 220° C. through a twin-screw extruder to obtain a polypropylene composition.

[0072] The modified porous silicon powder used is obtained from Preparation Example 1, and the lubricant used is the modified oxidized polyethylene wax obtained from Preparation Example 6.

[0073] Example 4

[0074] A polypropylene composition having good adhesion with silicone adhesive and a preparation method thereof, wherein the specific implementation manner is the same as that of Example 1, except that the modified porous silicon powder used is obtained from Preparation Example 2.

[0075] Example 5

[0076] A polypropylene composition having good adhesion with silicone adhesive and a preparation method thereof, wherein the specific implementation manner is the same as that of Example 1, except that the modified porous silicon powder used is obtained from Preparation Example 3.

[0077] Example 6

[0078] A polypropylene composition having good adhesion with silicone adhesive and a preparation method thereof, wherein the specific implementation manner is the same as that of Example 1, except that the modified porous silicon powder used is obtained from Preparation Example 4.

[0079] Example 7

[0080] A polypropylene composition having good adhesion with silicone adhesive and a preparation method thereof, wherein the specific implementation manner is the same as that of Example 1, except that the modified porous silicon powder used is obtained from Preparation Example 5.

[0081] Example 8

[0082] A polypropylene composition having good adhesion with silicone adhesive and a preparation method thereof, wherein the specific implementation manner is the same as that of Example 1, except that the lubricant used is the modified oxidized polyethylene wax obtained in Preparation Example 7.

[0083] Example 9

[0084] A polypropylene composition having good adhesion with silicone adhesive and a preparation method thereof, wherein the specific implementation manner is the same as that of Example 1, except that the lubricant used is oxidized polyethylene wax.

[0085] Comparative Example 1

[0086] A polypropylene composition having good adhesion with silicone adhesive and a preparation method thereof, wherein the specific implementation manner is the same as that of Example 1, except that the modified porous silicon powder is replaced by an equal amount of porous silicon powder.

[0087] Performance Testing:

[0088] The polypropylene compositions prepared in the above Examples 1-9 and Comparative Example 1 were melt extruded at 220°C, cast by a 30°C casting chill roll, and stretched to 4 times in both the transverse and longitudinal directions at 160°C to obtain substrates for the following performance tests. The specific test results are shown in Table 1:

[0089] (1) Surface energy test: The surface energy of each polypropylene composition substrate was tested according to standard GB / T 14216-2008;

[0090] (2) Peel strength test: According to the invention patent CN113528079B method and standard GB / T13477.18-2002, the above substrates and silicone adhesive (model: Dow Corning 791) were used to prepare samples to measure the peel strength to characterize the bonding strength;

[0091] (3) Durability test: With reference to the invention patent CN113528079B method and standard GB / T13477.18-2002, the above substrates and silicone adhesive (model: Dow Corning 791) were used to prepare samples. Each sample was placed in an indoor environment with a temperature of 23±2°C and a relative humidity of 50±5% for 100 days. The peel strength was measured again, and the difference was subtracted from the corresponding peel strength of the performance test (2) to obtain the peel strength reduction value to characterize the durability.

[0092] Table 1

[0093]

[0094]

[0095] It can be seen from Table 1 that the surface energy, bonding strength and bonding durability of the polypropylene compositions disclosed in Examples 1 to 3 of the present invention are all relatively excellent.

[0096] By comparing Example 4 with Example 1, it can be seen that when the amount of γ-aminopropyltriethoxysilane added in the preparation of the modified porous silicon powder is changed, the polypropylene composition will have insufficient surface energy, poor bonding strength and poor bonding durability due to the precipitation of polar substances;

[0097] By comparing Example 5 with Example 1, it can be seen that when the amount of hexene added in the preparation of the modified porous silicon powder is changed, the bonding is affected, and the bonding strength and bonding durability of the polypropylene composition decrease to varying degrees;

[0098] By comparing Example 6 with Example 1, it can be seen that when the amount of acrylate added in the preparation of modified porous silicon powder is changed, the through-network structure between the components is affected, resulting in a decrease in the stability of the polypropylene composition, and its surface energy, bonding strength and bonding durability are all deteriorated;

[0099] By comparing Example 7 with Example 1, it can be seen that when the average particle size of the porous silicon powder is changed during the preparation of the modified porous silicon powder, the surface energy of the polypropylene composition is greatly affected, and the bonding performance of the polypropylene composition is also indirectly affected;

[0100] By comparing Example 8 with Example 1, it can be seen that when the amount of triethanolamine added during the preparation of the modified oxidized polyethylene wax is changed, the bonding strength and bonding durability of the polypropylene composition will deteriorate;

[0101] By comparing Example 9 with Example 1, it can be seen that when oxidized polyethylene is used as a lubricant, the surface energy, bonding strength and bonding durability of the polypropylene composition will deteriorate due to the compatibility between the systems.

[0102] From the comparison between Comparative Example 1 and Example 1, it can be seen that when the modified porous silicon powder is replaced by an equal amount of porous silicon powder, the surface energy, bonding strength and bonding durability of the polypropylene composition will decrease to varying degrees.

[0103] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technician familiar with this profession can make some changes or modifications to equivalent embodiments of equivalent changes using the technical contents disclosed above without departing from the scope of the technical solution of the present invention. However, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A polypropylene composition having good adhesion to silicone adhesive, characterized in that: The polypropylene composition comprises the following raw materials in parts by weight: 40-80 parts of polypropylene, 20-45 parts of modified porous silicon powder, 0.5-5 parts of lubricant and 0.5-2 parts of other additives; The polypropylene is copolymerized polypropylene; The preparation steps of the modified porous silicon powder are as follows: The porous silicon powder and the emulsifier are mixed and added into water, and after ultrasonic dispersion, the temperature is raised to 60-80° C., an amino-containing silane coupling agent is added, and the mixture is stirred and reacted for 1-4 hours, and the temperature is further raised to 85-90° C., hexene, acrylic acid monomer and initiator are added, and the mixture is reacted for 1-3 hours, and the modified porous silicon powder is obtained after demulsification, filtration, washing and drying; The porous silicon powder is nano-scale porous silicon powder; The average particle size of the nano-porous silicon powder is 6-10 nm; The amino-containing silane coupling agent is γ-aminopropyltriethoxysilane; The mass ratio of the porous silicon powder, the amino-containing silane coupling agent, hexene and acrylic acid monomer is 1: (4-6): (2-4): (3-6); The lubricant is modified oxidized polyethylene wax; The preparation steps of the modified oxidized polyethylene wax are as follows: The oxidized polyethylene wax and the organic solvent are mixed, triethanolamine and p-toluenesulfonic acid are added, the temperature is raised to 100-120° C., the mixture is stirred for reaction for 1-2 hours, and the modified oxidized polyethylene wax is obtained by drying; The mass ratio of the oxidized polyethylene wax to triethanolamine is 10: (0.1-0.3).

2. A method for preparing a polypropylene composition having good adhesion to silicone adhesive according to claim 1, characterized in that: The method comprises the following steps: mixing polypropylene, modified porous silicon powder, lubricant and other additives, and performing melt extrusion granulation at 180-220° C. through a twin-screw extruder to obtain the polypropylene composition.

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