A fluorocarbon modified silicone resin and its preparation method and application

Abstract

The present invention provides a fluorocarbon modified silicone resin and a preparation method and application thereof. The fluorocarbon modified silicone resin can perfectly integrate the characteristics of the two by using a fluorocarbon structure as a side chain graft of silicone, thereby overcoming the defect that the fluorocarbon modification on the market is difficult to play a synergistic role because the characteristics of fluorine and silicon are quite different and, from a microscopic point of view, the performance of each chain segment is still the main factor. The prepared fluorocarbon modified silicone resin has good heat resistance. The fluorocarbon modified silicone provided by the present invention is used in a coating, which has good heat resistance, good corrosion resistance and weather resistance, and has good application prospects.

Description

Technical Field

[0001] The present invention relates to the technical field of organosilicon materials, and in particular to a fluorocarbon modified organosilicon resin and a preparation method and application thereof. Background Art

[0002] Silicone resin is a highly cross-linked polysiloxane with a network structure. It is usually prepared by hydrolyzing various mixtures of methyltrichlorosilane, dimethyldichlorosilane, phenyltrichlorosilane, diphenyldichlorosilane or methylphenyldichlorosilane at a relatively low temperature in the presence of an organic solvent such as toluene to obtain an acidic hydrolyzate. The initial product of the hydrolysis is a mixture of cyclic, linear and cross-linked polymers, which usually also contains a considerable amount of hydroxyl groups. The hydrolyzate is washed with water to remove the acid, and the neutral primary polycondensate is further polycondensed by thermal oxidation in the air or in the presence of a catalyst to finally form a highly cross-linked three-dimensional network structure.

[0003] Silicone resin and modified silicone resin products are widely used in defense and military industry, electrical industry, leather industry, light industrial products, rubber and plastics, food hygiene and other industries due to their excellent thermal oxidation stability, electrical insulation performance, weather resistance, waterproofness, salt spray resistance, mildew resistance, biocompatibility and other properties, playing an irreplaceable role.

[0004] With the increasing demand for high-temperature resistant materials, silicone resin, as a type of material with outstanding characteristics, can be modified and matched with non-silicon organic resins and inorganic materials to achieve structural and functional integration, and has broad application prospects in high-tech industries and cutting-edge fields. The heat resistance of silicone resin is generally better than that of conventional non-silicon organic resins, but the adhesion and cohesive strength of the coating prepared by silicone resin after curing are not as good as those of modified non-silicon organic resins. Compared with other conventional coatings of non-silicon organic resins, silicone resin coatings usually have a higher heat resistance range. Although silicone resin coatings have excellent heat resistance and weather resistance, most of them require high-temperature curing, which increases the difficulty of large-scale construction. At the same time, there are also problems such as relatively poor adhesion, insufficient mechanical strength, and poor resistance to chemical reagents and solvents. Many non-silicon organic resins in the prior art have good performance in these aspects, so non-silicon organic resins are used to modify silicone resins so that they have the excellent performance of both non-silicon organic resins and silicone resins.

[0005] In terms of high temperature resistance, the resins used for silicone resin modification mainly include epoxy resin, polyester resin, polyimide resin and phenolic resin. There are two methods for modifying silicone resin: one is physical modification, that is, physical blending. Generally, there is no chemical reaction between organic resins without silicon and silicone resins, but simply mixing. Since silicone resins have low surface energy and solubility parameters are quite different from other resins, the compatibility between the two is poor, and the physical modification effect is generally not ideal. The second is chemical modification, that is, introducing organic resins into the molecular chains of silicone resins through chemical reactions to achieve molecular-level compatibility. By controlling the addition ratio of organic resins and targeted synthesis processes, modified silicone resins with better comprehensive performance can be obtained. However, the fluorocarbon-modified silicones currently on the market are still mainly based on the performance of their respective chain segments from a microscopic perspective, as the properties of fluorine and silicon are quite different, and it is difficult to play a good synergistic role. The heat resistance of this modified silicone resin still has room for improvement. At the same time, while improving other properties such as adhesion and weather resistance, the heat resistance of the silicone resin will be sacrificed to a certain extent. Patent CN112832034B discloses a modified silicone resin and its application in polyurethane solvent-free decorative leather, furniture leather, and automotive leather. The modified silicone resin in the patent has good scratch resistance and corrosion resistance, but the heat resistance is lost. Therefore, it is necessary to provide a new modified silicone resin with multiple properties, which is applied to coatings and has not only good heat resistance, but also good corrosion resistance and weather resistance to meet practical application needs. Summary of the invention

[0006] In order to solve the above problems, the present invention provides a fluorocarbon modified silicone resin. By grafting the fluorocarbon structure as the side chain of silicone, the modified silicone resin has good heat resistance and is applied to coatings. In addition to having good heat resistance, the silicone resin also has good corrosion resistance and weather resistance.

[0007] The present invention discloses a fluorocarbon modified silicone resin, the structure of which is shown in general formula A:

[0008]

[0009] Among them, x=5-36, y=1-30, z=0-1, a=4-25, b=10-45, c=0-6.

[0010] As a further embodiment of the fluorocarbon-modified silicone resin of the present invention, the value of x in the general formula A can be 5, 10, 15, 20, 25, 30, or 35.

[0011] As a further embodiment of the fluorocarbon-modified silicone resin of the present invention, the value of y in the general formula A can be 1, 5, 10, 15, 20, 25, or 30.

[0012] As a further embodiment of the fluorocarbon-modified silicone resin of the present invention, the value of z in the general formula A can be 0 or 1.

[0013] As a further embodiment of the fluorocarbon-modified silicone resin of the present invention, the value of a in the general formula A can be 5, 10, 15, 20, or 25.

[0014] As a further embodiment of the fluorocarbon-modified silicone resin of the present invention, the value of b in the general formula A can be 10, 15, 20, 25, 30, 35, 40, or 45.

[0015] As a further embodiment of the fluorocarbon-modified silicone resin of the present invention, the value of c in the general formula A can be 0, 1, 2, 3, 4, 5, or 6.

[0016] Preferably, in the general formula A, x=5-30.

[0017] Preferably, in the general formula A, y=1-10.

[0018] Preferably, in the general formula A, a=5-10.

[0019] Preferably, in the general formula A, b=10-25.

[0020] Preferably, in the general formula A, c=3-4.

[0021] A method for preparing a fluorocarbon-modified organic silicone resin, the method comprising the following steps:

[0022] (1) dissolving 2,4,6,8-tetramethylcyclotetrasiloxane in toluene, adding a catalyst, heating the system to 60-70° C., adding a vinyl perfluoroalkane as shown in formula B to react, removing the catalyst after the reaction is completed, and distilling off toluene to obtain an intermediate product as shown in formula C.

[0023]

[0024] (2) mixing the intermediate product of formula C with octamethylcyclotetrasiloxane and 1,1,3,3-tetramethyldisiloxane, adding a solid superacid catalyst, reacting at 25-35° C. for 20-40 hours, filtering to remove the solid superacid catalyst after the reaction is completed, and distilling to remove the unreacted octamethylcyclotetrasiloxane to obtain the intermediate product of formula D,

[0025]

[0026] (3) adding the intermediate product represented by formula D to the allyl polyether, starting stirring, raising the system temperature to 60-70° C., adding a catalyst, controlling the reaction temperature to be lower than 90° C., and removing the catalyst after the reaction is completed. The product is the fluorocarbon-modified silicone resin.

[0027] In the preparation method of the fluorocarbon-modified silicone resin of the present invention, the molar ratio of 2,4,6,8-tetramethylcyclotetrasiloxane to vinyl perfluoroalkane in step (1) is 1:4-8, and the catalyst is chloroplatinic acid.

[0028] In the preparation method of the fluorocarbon-modified silicone resin of the present invention, the molar ratio of the intermediate product I, octamethylcyclotetrasiloxane and 1,1,3,3-tetramethyldisiloxane in step (2) is 1:3-6:1-2.

[0029] In the method for preparing the fluorocarbon-modified silicone resin of the present invention, the molar ratio of the intermediate product II to the allyl polyether in step (3) is 1:2-4.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] The fluorocarbon modified silicone resin provided by the present invention can perfectly integrate the characteristics of the two by using the fluorocarbon structure as the side chain graft of silicone, thus solving the defect that the fluorocarbon modified resin on the market is difficult to play a synergistic role because the characteristics of fluorine and silicon are far different, and from a microscopic perspective, the performance of each chain segment is still the main factor, so that the prepared fluorocarbon modified silicone resin has good heat resistance. The fluorocarbon modified silicone provided by the present invention is applied to coatings, which has good corrosion resistance and weather resistance in addition to good heat resistance. In addition, since no long-chain fluorocarbon structure is used, the biological toxicity of the final product is avoided, and it has good application prospects. DETAILED DESCRIPTION

[0032] The present invention will be described below in conjunction with specific embodiments. It should be noted that the following examples are examples of the present invention and are only used to illustrate the present invention, but not to limit the present invention. Without departing from the gist or scope of the present invention, other combinations and various improvements within the concept of the present invention may be carried out. The raw materials and reagents used in the examples can all be purchased on the market, wherein vinyl perfluoroalkane is purchased from Quzhou Shengxingda Synthetic Material Co., Ltd., solid superacid catalyst is purchased from Kehaisi (Beijing) Technology Co., Ltd., and allyl polyether B-300 is purchased from Yangzhou Chenhua Technology Group Co., Ltd.

[0033] Example 1

[0034] A fluorocarbon-modified organic silicon resin, wherein the preparation method of the fluorocarbon-modified organic silicon resin comprises the following steps:

[0035] (1) 1 mol of 2,4,6,8-tetramethylcyclotetrasiloxane is dissolved in 2000 ml of toluene, 0.01 g of chloroplatinic acid is added, the system is heated to 65° C., 4 mol of vinyl perfluoroalkane is added for reaction, after the reaction is completed, the catalyst is removed, and toluene is removed by distillation to obtain an intermediate product I;

[0036] (2) 0.1 mol of intermediate product I was mixed with 0.3 mol of octamethylcyclotetrasiloxane and 0.1 mol of 1,1,3,3-tetramethyldisiloxane, and 10 g of a solid superacid catalyst was added. The mixture was reacted at 30° C. for 30 hours. After the reaction was completed, the solid superacid catalyst was removed by filtration, and the unreacted octamethylcyclotetrasiloxane was removed by distillation to obtain intermediate product II;

[0037] (3) Take 0.1 mol of intermediate product II and add it to 0.2 mol of allyl polyether B-300, start stirring, raise the system temperature to 65°C, add 0.005 g of chloroplatinic acid, use circulating water to cool down, control the reaction temperature below 90°C, wait for the reaction to end, remove the chloroplatinic acid, and the product is a fluorocarbon modified silicone resin.

[0038] Example 2

[0039] A fluorocarbon-modified organic silicon resin, wherein the preparation method of the fluorocarbon-modified organic silicon resin comprises the following steps:

[0040] (1) 1 mol of 2,4,6,8-tetramethylcyclotetrasiloxane is dissolved in 2000 ml of toluene, 0.01 g of chloroplatinic acid is added, the system is heated to 65° C., 4 mol of vinyl perfluoroalkane is added for reaction, after the reaction is completed, the catalyst is removed, and toluene is removed by distillation to obtain an intermediate product I;

[0041] (2) 0.1 mol of intermediate product I was mixed with 0.6 mol of octamethylcyclotetrasiloxane and 0.1 mol of 1,1,3,3-tetramethyldisiloxane, and 8 g of a solid superacid catalyst was added, and the mixture was reacted at 30° C. for 30 hours. After the reaction was completed, the solid superacid catalyst was removed by filtration, and the unreacted octamethylcyclotetrasiloxane was removed by distillation to obtain intermediate product II;

[0042] (3) Take 0.1 mol of intermediate product II and add it to 0.2 mol of allyl polyether B-300, start stirring, raise the system temperature to 65°C, add 0.005 g of chloroplatinic acid, use circulating water to cool down, control the reaction temperature below 90°C, wait for the reaction to end, remove the chloroplatinic acid, and the product is a fluorocarbon modified silicone resin.

[0043] Example 3

[0044] A fluorocarbon-modified organic silicon resin, wherein the preparation method of the fluorocarbon-modified organic silicon resin comprises the following steps:

[0045] (1) 1 mol of 2,4,6,8-tetramethylcyclotetrasiloxane is dissolved in 2000 ml of toluene, 0.01 g of chloroplatinic acid is added, the system is heated to 65° C., 4 mol of vinyl perfluoroalkane is added for reaction, after the reaction is completed, the catalyst is removed, and toluene is removed by distillation to obtain an intermediate product I;

[0046] (2) 0.1 mol of intermediate product I was mixed with 0.6 mol of octamethylcyclotetrasiloxane and 0.1 mol of 1,1,3,3-tetramethyldisiloxane, and 8 g of a solid superacid catalyst was added, and the mixture was reacted at 30° C. for 30 hours. After the reaction was completed, the solid superacid catalyst was removed by filtration, and the unreacted octamethylcyclotetrasiloxane was removed by distillation to obtain intermediate product II;

[0047] (3) Take 0.1 mol of intermediate product II and add it to 0.2 mol of allyl polyether B-300, start stirring, raise the system temperature to 70°C, add 0.005 g of chloroplatinic acid, use circulating water to cool down, control the reaction temperature below 90°C, wait for the reaction to end, remove the chloroplatinic acid, and the product is a fluorocarbon modified silicone resin.

[0048] Example 4

[0049] A fluorocarbon-modified organic silicon resin, wherein the preparation method of the fluorocarbon-modified organic silicon resin comprises the following steps:

[0050] (1) 1 mol of 2,4,6,8-tetramethylcyclotetrasiloxane is dissolved in 2000 ml of toluene, 0.01 g of chloroplatinic acid is added, the system is heated to 65° C., 4 mol of vinyl perfluoroalkane is added for reaction, after the reaction is completed, the catalyst is removed, and toluene is removed by distillation to obtain an intermediate product I;

[0051] (2) 0.1 mol of intermediate product I was mixed with 0.4 mol of octamethylcyclotetrasiloxane and 0.2 mol of 1,1,3,3-tetramethyldisiloxane, and 8 g of a solid superacid catalyst was added. The mixture was reacted at 30° C. for 30 hours. After the reaction was completed, the solid superacid catalyst was removed by filtration, and the unreacted octamethylcyclotetrasiloxane was removed by distillation to obtain intermediate product II;

[0052] (3) Take 0.1 mol of intermediate product II and add it to 0.2 mol of allyl polyether B-300, start stirring, raise the system temperature to 70°C, add 0.005 g of chloroplatinic acid, use circulating water to cool down, control the reaction temperature below 90°C, wait for the reaction to end, remove the chloroplatinic acid, and the product is a fluorocarbon modified silicone resin.

[0053] Comparative Example

[0054] A modified organic silicone resin, wherein the preparation method of the modified organic silicone resin comprises the following steps:

[0055] (1) 0.1 mol of 2,4,6,8-tetramethylcyclotetrasiloxane, 0.3 mol of octamethylcyclotetrasiloxane and 0.1 mol of 1,1,3,3-tetramethyldisiloxane were mixed, 10 g of a solid superacid catalyst was added, and the mixture was reacted at 30° C. for 30 hours. After the reaction was completed, the solid superacid catalyst was removed by filtration, and the unreacted octamethylcyclotetrasiloxane was removed by distillation to obtain an intermediate product;

[0056] (2) Take 0.1 mol of the intermediate product and add it to 0.2 mol of allyl polyether B-300, start stirring, raise the system temperature to 65°C, add 0.005 g of chloroplatinic acid, use circulating water to cool down, control the reaction temperature below 90°C, wait for the reaction to end, remove the chloroplatinic acid, and the product is a modified silicone resin.

[0057] The heat resistance of the fluorocarbon-modified silicone resin prepared in each embodiment and comparative example was tested by using a thermal gravimetric analyzer TGA. The results are shown in Table 1.

[0058] Table 1

[0059] serial number 5% weight loss temperature Example 1 402℃ Example 2 399℃ Example 3 397℃ Example 4 394℃ Comparative Example 373℃

[0060] By comparing the test results of the embodiments in Table 1 with the comparative examples, it can be seen that the fluorocarbon-modified silicone resin provided by the present invention can perfectly combine the characteristics of the two by using the fluorocarbon structure as the side chain graft of silicone, so that the prepared fluorocarbon-modified silicone has excellent heat resistance and good application prospects.

[0061] Preparation of coating: 600g of polyester resin P1501 (produced by Huangshan Jiajie New Material Technology Co., Ltd.), 5g of triglycidyl isocyanurate, and 20g of the fluorocarbon modified silicone resin of the present invention are added to a high-speed mixer and mixed evenly, extruded using a twin-screw extruder, and then tableted and crushed to form a uniform powder. Performance tests were performed on coating samples (corresponding to sample 1, sample 2, sample 3, sample 4, and comparative sample, respectively) prepared using the modified silicone resins of Examples 1-4 and Comparative Examples:

[0062] 1. Weathering test: test the light retention rate of xenon lamp aging (1500h);

[0063] 2. Corrosion resistance test: According to the standard GB / T1771-2007 method, put the sample into the salt spray machine and use 5% NaCl solution for spray test to observe whether the sample is bubbling or rusting.

[0064] The measurement results are shown in Table 2:

[0065] Table 2

[0066]

[0067]

[0068] The performance test of the coating samples shows that the coating to which the fluorocarbon-modified silicone resin of the present invention is added has good effects in terms of weather resistance and corrosion resistance.

[0069] The above implementation modes are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with this technology to understand the content of the present invention and implement it, and they cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. Application of a fluorocarbon modified silicone resin in coatings, characterized in that: The preparation method of the fluorocarbon-modified silicone resin comprises the following steps: (1) Dissolve 2,4,6,8-tetramethylcyclotetrasiloxane in toluene, add a catalyst, heat the system to 60-70°C, add a vinyl perfluoroalkane as shown in formula B to react, remove the catalyst after the reaction is completed, and distill off toluene to obtain an intermediate product I B； (2) Mixing the intermediate product I with octamethylcyclotetrasiloxane and 1,1,3,3-tetramethyldisiloxane, adding a solid superacid catalyst, reacting at 25-35° C. for 20-40 hours, and after the reaction is completed, filtering to remove the solid superacid catalyst, and distilling to remove the unreacted octamethylcyclotetrasiloxane to obtain the intermediate product II; (3) adding the intermediate product II to the allyl polyether, starting stirring, raising the system temperature to 60-70°C, adding a catalyst, controlling the reaction temperature to be lower than 90°C, and removing the catalyst after the reaction is completed. The product is the fluorocarbon-modified silicone resin; The molar ratio of 2,4,6,8-tetramethylcyclotetrasiloxane to vinyl perfluoroalkane in step (1) is 1:4-8; The molar ratio of the intermediate product I, octamethylcyclotetrasiloxane and 1,1,3,3-tetramethyldisiloxane in step (2) is 1:3-6:1-2; the molar ratio of the intermediate product II and the allyl polyether in step (3) is 1:2-4; Preparation of the coating: 600 g of polyester resin P1501, 5 g of triglycidyl isocyanurate, and 20 g of the fluorocarbon modified silicone resin are added into a high-speed mixer and mixed evenly, extruded using a twin-screw extruder, and then tableted and crushed to form uniform powder.

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