An aluminum hydroxide functional filler-reinforced rubber composition and a method of making the same

Abstract

This invention relates to an aluminum hydroxide functional filler-reinforced rubber composition and its preparation method. The aluminum hydroxide functional filler-reinforced rubber composition comprises the following components in parts by weight: 80-100 parts styrene-butadiene rubber, 20-30 parts carbon black, 1-2 parts paraffin wax, 1-2 parts sulfur, 2-3 parts vulcanization accelerator, 8-10 parts additives, and 50-70 parts modified aluminum hydroxide. The modified aluminum hydroxide is obtained by copolymerizing aluminum hydroxide grafted with KH570 intermediate product 1, hydroxylated silica grafted with KH570 intermediate product 2, and phenyl acrylate and acrylate. The modified aluminum hydroxide of this invention introduces phenyl ester units, hydroxyl groups, and silica. These multiple active groups can improve compatibility with other components and generate interactions such as hydrogen bonds. Furthermore, aluminum hydroxide can also act as a flame retardant. The synergistic effect of the components improves various properties and has good application prospects.

Description

Technical Field

[0001] This invention relates to the field of rubber technology, and in particular to a rubber composition reinforced with aluminum hydroxide functional filler and its preparation method. Background Technology

[0002] Rubber compositions are mainly made by mixing raw rubber and various compounding agents in fixed mass proportions. After mixing and vulcanization, they become practical rubber materials with strength, elasticity, and durability. They are the basic formulas for various rubber products (tires, seals, hoses, shock absorbers).

[0003] Common components of rubber compositions include: raw rubber matrix, which determines the basic properties of rubber, such as natural rubber and styrene-butadiene rubber; fillers, which affect mechanical properties, such as carbon black, silica, calcium carbonate, talc; vulcanization system, which shapes the rubber, such as vulcanizing agents (sulfur, etc.), accelerators, activators, etc.; and additives, such as plasticizers, oils, flame retardants, resins, antioxidants, etc.

[0004] Rubber compositions have a wide range of applications, including: the automotive industry, such as tires, seals, and shock absorbers; the construction and home improvement industry, such as sealing strips, sound insulation and vibration damping pads, and waterstops; the electronics and electrical industry, such as wire and cable insulation layers, battery pack seals, sockets, buttons, and insulating gaskets; and the medical or daily necessities industry, such as medical gloves, rubber hoses, shoe soles, sports equipment, and handle covers.

[0005] Currently, there are many types of rubber composition products, but some problems still exist, such as: insufficient mechanical properties, which cause direct damage to stressed parts; lack of ductility, which makes the products prone to breakage; and slight deformation leading to direct cracking, such as seals which break easily when pulled. Insufficient flame retardancy makes the products extremely easy to ignite, and the flame spreads easily, posing serious safety hazards and failing to meet market demands.

[0006] In conclusion, it is necessary to develop a new technical solution to address the shortcomings of existing technologies. Summary of the Invention

[0007] This invention provides an aluminum hydroxide functional filler reinforced rubber composition and its preparation method. The aluminum hydroxide functional filler reinforced rubber composition incorporates modified aluminum hydroxide, introducing a variety of active groups, thereby improving the mechanical properties, flame retardant properties, etc. of the product.

[0008] The purpose of this invention is to provide an aluminum hydroxide functional filler reinforced rubber composition, wherein the aluminum hydroxide functional filler reinforced rubber composition comprises the following components in parts by weight: 80-100 parts of styrene-butadiene rubber 20-30 parts carbon black 1-2 parts paraffin 1-2 parts sulfur 2-3 parts of vulcanization accelerator 8-10 parts of auxiliary agent 50-70 parts of modified aluminum hydroxide; The modified aluminum hydroxide is an intermediate product 1 of aluminum hydroxide grafted with KH570, an intermediate product 2 of hydroxylated silica grafted with KH570, and a product obtained by copolymerization with phenyl acrylate and acrylate.

[0009] Furthermore, the additive is selected from one or more of aromatic oils, antioxidants, stearamide, stearic acid, zinc oxide, plasticizers, and multifunctional additives.

[0010] Furthermore, the vulcanization accelerator is selected from one or more of the following: sulfenamide-based vulcanization accelerators, guanidine-based vulcanization accelerators, thiuram-based vulcanization accelerators, and thiazole-based vulcanization accelerators.

[0011] Another object of the present invention is to provide a method for preparing the aluminum hydroxide functional filler reinforced rubber composition, the method comprising the following steps: S1. Aluminum hydroxide and KH570 are mixed and heated and stirred to react, yielding intermediate product 1; S2. Hydroxylated silicon dioxide is obtained; S3. The hydroxylated silica and KH570 are mixed and heated and stirred to obtain intermediate product 2. S4. Under an inert atmosphere, intermediate product 1, intermediate product 2, phenyl acrylate, acrylate, and initiator are blended and heated and stirred to react, thereby obtaining modified aluminum hydroxide. S5. Blend, knead, and vulcanize the components to obtain the aluminum hydroxide functional filler reinforced rubber composition.

[0012] Further, in step S1, the mass ratio of aluminum hydroxide to KH570 is (1-10):(0.5-3).

[0013] Furthermore, in step S1, the heating temperature is 70-90℃.

[0014] Further, in step S3, the mass ratio of the hydroxylated silicon dioxide to KH570 is (1-3):(0.5-3).

[0015] Furthermore, in step S3, the heating temperature is 70-90℃.

[0016] Furthermore, in step S4, the heating temperature is 60-90°C.

[0017] Further, in step S4, the mass ratio of intermediate product 1, intermediate product 2, phenyl acrylate, and acrylate is (1-3):1:(3-5):(5-8).

[0018] The present invention has the following beneficial effects: This invention provides an aluminum hydroxide functional filler reinforced rubber composition and its preparation method. The modified aluminum hydroxide is obtained by first grafting KH570 with aluminum hydroxide to obtain intermediate product 1, so that the surface of aluminum hydroxide has double bonds, then grafting KH570 with hydroxylated silica to obtain intermediate product 2, so that the surface of hydroxylated silica has double bonds, and finally copolymerizing intermediate product 1 and intermediate product 2 with phenyl acrylate and acrylate.

[0019] The modified aluminum hydroxide of this invention incorporates phenyl ester units, hydroxyl groups, and silicon dioxide. The phenyl ester units improve compatibility with components such as styrene-butadiene rubber (SBR) and promote uniform distribution of the components. The hydroxyl groups interact with other components through hydrogen bonding and other mechanisms, improving the mechanical properties and other performance characteristics of the product. The uniform distribution of silicon dioxide in the composition enhances the product's performance. Furthermore, aluminum hydroxide acts as a flame retardant because it absorbs heat and isolates oxygen. When aluminum hydroxide decomposes at high temperatures to produce water of crystallization, it dilutes the oxygen concentration, preventing intensified combustion. Simultaneously, it absorbs some heat and carries some heat away from the surface of the rubber composition. The water vapor also prevents the flame from contacting the rubber composition surface, further enhancing the flame retardant effect.

[0020] The formulation of this invention does not contain a large amount of free inorganic filler (aluminum hydroxide). All inorganic fillers are organically grafted onto the polymer, thus preventing organic-inorganic phase separation and avoiding product performance degradation caused by phase separation. Detailed Implementation

[0021] To more clearly illustrate the technical solution of the present invention, the following embodiments are provided. Unless otherwise stated, the raw materials, reactions, and post-processing methods appearing in the embodiments are all commercially available raw materials and technical methods well known to those skilled in the art.

[0022] The terms "preferred," "more preferably," and "more suitable" used in this invention refer to embodiments of the invention that provide certain beneficial effects under certain circumstances. However, other embodiments may also be preferred under the same or other circumstances. Furthermore, the description of one or more preferred embodiments does not imply that other embodiments are unavailable, nor is it intended to exclude other embodiments from the scope of this invention.

[0023] It should be understood that, except in any operational instance or otherwise indicated, the amounts or all figures representing ingredients used, for example, in the specification and claims, should be understood to be modified by the term "about" in all cases. Therefore, unless otherwise stated, the numerical parameters set forth in the following specification and appended claims are approximate values ​​varying according to the desired performance to be obtained according to the invention.

[0024] The embodiments of the present invention use the following raw materials: Styrene-butadiene rubber: Grade SBR emulsion BM430B, purchased from Dongguan Caihua Plastics Technology Co., Ltd.

[0025] Carbon black: grade N774, purchased from Shandong Kasong New Materials Co., Ltd.

[0026] Paraffin wax: Grade 58, purchased from Guangzhou Zhenghua New Materials Co., Ltd.

[0027] Sulfur: Insoluble sulfur, purchased from Jiangsu Runfeng Synthetic Technology Co., Ltd.

[0028] Vulcanization accelerator: N-cyclohexyl-2-benzothiazole sulfenamide, purchased from Hubei Qiansheng Biotechnology Co., Ltd.

[0029] Additives: Aromatic oil (purchased from Shandong Xinglong New Materials Co., Ltd.), antioxidant (N,N-diphenyl-p-phenylenediamine, purchased from Zhongshan Xingrui Chemical Co., Ltd.), stearamide (purchased from Jinan Huifengda Chemical Co., Ltd.), stearic acid, and zinc oxide (purchased from Henan Mingzhixin Chemical Products Co., Ltd.) are mixed in a mass ratio of 27:4:3:2:4.

[0030] Silica: Particle size 50-90nm.

[0031] Aluminum hydroxide: purchased from Foshan Yincheng Chemical Co., Ltd.

[0032] Emulsifier: OP-10, purchased from Aladdin.

[0033] The composition and mass fractions of the aluminum hydroxide functional filler-reinforced rubber compositions of Examples 1-3 are shown in Table 1.

[0034] Table 1. Composition and mass parts of aluminum hydroxide functional filler-reinforced rubber compositions in Examples 1-3

[0035] Examples 1-3 A method for preparing an aluminum hydroxide functional filler-reinforced rubber composition, the method comprising the following steps: S1. Using deionized water and isopropanol in a mass ratio of 1:1 as solvents, aluminum hydroxide and KH570 were mixed in a mass ratio of 9:1, heated to 80°C and stirred for 1 hour, filtered and dried to obtain intermediate product 1. S2. Immerse silica in a mixed solution of concentrated sulfuric acid and 30wt% hydrogen peroxide at a volume ratio of 7:3, react at 80℃ for 1 hour, filter, wash and dry to obtain hydroxylated silica. S3. Using ethanol and water in a volume ratio of 1:1 as solvents, the hydroxylated silica and KH570 were mixed in a mass ratio of 3:2, heated to 75°C and stirred for 6 hours. The solvent was removed, the mixture was washed and dried to obtain intermediate product 2. S4. Under a nitrogen atmosphere, intermediate product 1, intermediate product 2, phenyl acrylate, hydroxyethyl acrylate, initiator ammonium persulfate, emulsifier, and solvent water are mixed in a mass ratio of 2:1:4:5:0.15:0.4:25, heated to 70°C and stirred for 24 hours, filtered, washed, and dried to obtain modified aluminum hydroxide. S5. According to the above-mentioned mass proportions, all components except sulfur and vulcanization accelerator are mixed in an internal mixer and kneaded for 3 minutes at a discharge temperature of 155°C to obtain a kneaded product. Then, using an open mill, sulfur and vulcanization accelerator are added to the kneaded product and kneaded for 1 minute at a discharge temperature of 100°C to obtain a rubber sheet. The rubber sheet is vulcanized at 170°C for 18 minutes to obtain the aluminum hydroxide functional filler reinforced rubber composition.

[0036] Comparative Example 1 The difference between Comparative Example 1 and Example 1 is that step S1 is deleted and intermediate product 1 is replaced with aluminum hydroxide. The remaining components and preparation methods are the same as in Example 1.

[0037] Comparative Example 2 The difference between Comparative Example 2 and Example 1 is that the phenyl acrylate in step S4 is replaced with ethyl acrylate by mass, while the remaining components and preparation methods are the same as in Example 1.

[0038] Test case The performance of the rubber compositions of Examples 1-3 and Comparative Examples 1-2 was tested.

[0039] Test method: Tensile strength: Tested in accordance with GB / T 528-2009.

[0040] Elongation at break: Tested in accordance with GB / T 528-2009.

[0041] Limiting oxygen index for flame retardancy testing: Tested in accordance with GB / T 10707-2008.

[0042] Flame retardancy test UL-94: Tested in accordance with GB / T 2408-2008.

[0043] The test results are shown in Table 2.

[0044] Table 2 Test Results

[0045] As can be seen from Table 2, the effects of Examples 1-3 are better than those of Comparative Examples 1-2. This is because the aluminum hydroxide in Comparative Example 1 was not grafted with KH570, so it could not react in the subsequent modification process, resulting in free aluminum hydroxide in the rubber composition and easy aggregation, which led to a decrease in the performance of the product. In contrast, the modified aluminum hydroxide in Comparative Example 2 did not introduce phenyl ester units, which led to a decrease in the compatibility of the components and uneven dispersion of the components, resulting in a decrease in the performance of the product.

[0046] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.

[0047] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A rubber composition reinforced with aluminum hydroxide functional filler, characterized in that, The aluminum hydroxide functional filler reinforced rubber composition comprises the following components in parts by weight: 80-100 parts of styrene-butadiene rubber 20-30 parts carbon black 1-2 parts paraffin 1-2 parts sulfur 2-3 parts of vulcanization accelerator 8-10 parts of auxiliary agent 50-70 parts of modified aluminum hydroxide; The modified aluminum hydroxide is an intermediate product 1 of aluminum hydroxide grafted with KH570, an intermediate product 2 of hydroxylated silica grafted with KH570, and a product obtained by copolymerization with phenyl acrylate and acrylate.

2. The aluminum hydroxide functional filler reinforced rubber composition according to claim 1, characterized in that, The additives are selected from one or more of the following: aromatic oils, antioxidants, stearamide, stearic acid, zinc oxide, plasticizers, and multifunctional additives.

3. The aluminum hydroxide functional filler reinforced rubber composition according to claim 1, characterized in that, The vulcanization accelerator is selected from one or more of the following: sulfenamide-based vulcanization accelerators, guanidine-based vulcanization accelerators, thiuram-based vulcanization accelerators, and thiazole-based vulcanization accelerators.

4. A method for preparing the aluminum hydroxide functional filler-reinforced rubber composition according to any one of claims 1-3, characterized in that, The preparation method of the aluminum hydroxide functional filler reinforced rubber composition includes the following steps: S1. Aluminum hydroxide and KH570 are mixed and heated and stirred to react, yielding intermediate product 1; S2. Hydroxylated silicon dioxide is obtained; S3. The hydroxylated silica and KH570 are mixed and heated and stirred to obtain intermediate product 2. S4. Under an inert atmosphere, intermediate product 1, intermediate product 2, phenyl acrylate, acrylate, and initiator are blended and heated and stirred to react, thereby obtaining modified aluminum hydroxide. S5. Blend, knead, and vulcanize the components to obtain the aluminum hydroxide functional filler reinforced rubber composition.

5. The method for preparing the aluminum hydroxide functional filler-reinforced rubber composition according to claim 4, characterized in that, In step S1, the mass ratio of aluminum hydroxide to KH570 is (1-10):(0.5-3).

6. The method for preparing the aluminum hydroxide functional filler-reinforced rubber composition according to claim 4, characterized in that, In step S1, the heating temperature is 70-90℃.

7. The method for preparing the aluminum hydroxide functional filler-reinforced rubber composition according to claim 4, characterized in that, In step S3, the mass ratio of hydroxylated silica to KH570 is (1-3):(0.5-3).

8. The method for preparing the aluminum hydroxide functional filler-reinforced rubber composition according to claim 4, characterized in that, In step S3, the heating temperature is 70-90℃.

9. The method for preparing the aluminum hydroxide functional filler reinforced rubber composition according to claim 4, characterized in that, In step S4, the heating temperature is 60-90℃.

10. The method for preparing the aluminum hydroxide functional filler-reinforced rubber composition according to claim 4, characterized in that, In step S4, the mass ratio of intermediate product 1, intermediate product 2, phenyl acrylate, and acrylate is (1-3):1:(3-5):(5-8).

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