Properties and application of the hottest type 1 a

The performance and application of FR1 adhesive

the adhesion of fluororubber, silicone rubber, EPDM and metal has always been a technical difficulty in the rubber industry. In recent years, due to the development of science and technology, the above rubber and metal bonded products have been used more and more widely, and the demand is increasing. According to the data of Shanghai sanaifu company and the second branch of Sichuan Chenguang Chemical Industry Research Institute, the sales volume of fluororubber in Qingdao in 2002 was as much as 100t, 10 times that of five years ago. The demand for EPDM and silicone rubber is also increasing significantly, and the corresponding demand for adhesives is also growing rapidly. However, the adhesives supplied in the market are difficult to meet the demand, and most of them are imported from abroad, which is expensive. Therefore, we have developed FR1 adhesive, which is used for the hot vulcanization adhesion of fluororubber, silicone rubber, ethylene propylene diene rubber and metal, solved the technical problems and achieved good benefits

1 experimental part

1.1 material

fr1 adhesive, self-made; Fluororubber 260226032463, Shanghai sanaifu organic fluoromaterials Co., Ltd; Fluororubber g752, Japan Daquan Industry Co., Ltd; Silicone rubber 909, Jiangsu Zhenjiang Hongda Chemical Co., Ltd; Oil resistant silicone rubber 9470, Zhejiang Ningbo Changtai rubber technology and Trade Co., Ltd; EPDM 46404570, DuPont; 3 # vulcanizing agent (n, n double cinnamon 16 hexanediamine), Shanghai reagent No.1 Factory; BPP (benzyl triphenyl phosphorus chloride), Shanghai Pengpu chemical plant; Bisphenol AF, Shanghai sanaifu organic fluorine material company; Vulcanizing agent DCP, Jiangsu Dachang chemical plant; Vulcanizing agent Shuang Wu, Jiangsu Qiangsheng Chemical Co., Ltd; Other materials are commercially available

1.2 drop weight impact testing machine and non-metallic impact testing machine equipment

xk160, xk400 open mill, q3110 shot blasting machine (for sand blasting), skeleton phosphating production line, 50t, 100t flat plate vulcanizer

1.3 test process

the metal skeleton adopts two treatment methods: one is to use Q to ignore this point. 3110 drum shot blasting machine is used for sand blasting, and then solvent butanone is used to clean, degrease and degrease, and apply adhesive; Second, the skeleton is degreased and degreased with alkaline solution, washed with flowing water, then put into acid for derusting, taken out and washed with water, put into y836 medium temperature phosphating solution for phosphating, and then put into 1.5% - 2% sodium chromate aqueous solution for passivation and drying, cleaned with butanone, and coated with adhesive. After mixing, the rubber is taken off and stored for 24h. After pre molding, the rubber embryo and framework are put into the mold on the plate vulcanizer for vulcanization. Fluororubber and silicone rubber also need secondary vulcanization

evaluation method of adhesive performance: store the vulcanized products for 30min, peel them with pointed nose pliers, and evaluate the adhesive performance by the percentage of the coating amount. This method is closer to the actual situation than the pull-out test. It can not only observe the glue coating amount of the radial part (i.e. the bottom surface of the product), but also observe the glue coating amount of the axial part, and also observe the pollution degree of the mold [1]

2 results and discussion

2.1 for bonding metal framework to fluororubber

bonding in self-made FR1 5. Actuator Zui large amplitude: 100mm; Before the agent, we used a variety of hot vulcanized adhesives of fluororubber and metal, such as camlock 6075150, ap133, France 512, Germany cp22, Italy 32901 and its phenolic and isocyanate BN, leck sodium, etc. We found that France 512 and Germany cp22 have good adhesion performance, stable quality, and the amount of coating is more than 70%. The operation process is simple and easy, but the price is expensive (512 1100 yuan per liter, cp22 650 yuan per liter). For this reason, we refer to silane adhesives for development. After many tests, we trial produce many kinds of adhesives, and screen teknor& in terms of quality and cost; nbsp; Apex high performance materials & nbsp; Help to build high-quality automobile exterior decoration parts, and finally determine that FR1 will be put into use, with a cost of about 50 yuan per liter. The adhesive has stable quality, simple preparation process and low manufacturing cost. The adhesive is used for skeleton oil seal, valve stem oil seal and micro bearing cover seal, and has been recognized by many seal manufacturers. The adhesive also has certain selectivity to the rubber formula, but it is not very obvious. For example, it can be used in the formula of 3 # vulcanizing agent: fluororubber 2602100, light magnesium oxide 15, calcium hydroxide 5, filler 15, operating agent 2, 3 # vulcanizing agent 3; Formula for low compression set: 2602100, active magnesium oxide 5, calcium hydroxide 5, filler 20, operating aid 2, bisphenol af20, bpp0 6; G752100 (with vulcanizing agent), filler 15, operating aid 2, active magnesium oxide 5, calcium hydroxide 4 from Japan Daquan Co., Ltd. After the rubber is mixed and stored for 24h, it is vulcanized with the skeleton after phosphating, passivation and solvent cleaning (165 ℃) × 12min), secondary vulcanization (200 ℃ × 24h), the product is 65 × ninety × 12 framework oil seal. After peeling test, the fluororubber compound prepared with 3 # vulcanizing agent has a covering amount of more than 70% and is firmly bonded. The coating amount of the other two test formulas is also more than 70%, which is equivalent to that of 512 and cp-22. However, some products have broken lip in the test, indicating that the tearing property of the compound is poor. The origin and amount of light magnesium oxide have an impact on the adhesion performance. In production, it is found that the amount of light magnesium oxide is stable at 12 ~ 15 parts, fluctuates below 12 parts, and is higher than 15 parts, and the strength of the compound is low

the bonding quality of light magnesium oxide produced by Shanghai Dunhuang chemical plant and Qingdao Guhe chemical plant is stable. In the production process, sometimes we encounter low-quality light magnesium oxide, which seriously affects the bonding quality (mainly foaming and polluting the mold bonding, resulting in quality degradation). Fillers such as spray carbon black N990, iron oxide red, calcium fluoride, barium sulfate, wollastonite powder, silica dry soil, etc. as long as the materials are not fake and inferior products, it is generally not found that it will lead to the decline of bonding quality. The amount of processing aids, i.e. dispersant and internal release agent, should be controlled within 2 parts as much as possible, because excessive amount is detrimental to bonding. The origin of fluororubber has little effect on adhesion. The 2601, 2602, 2603 of the second branch of Sichuan Chenguang academy and 2601, 2602, 2603, 2463 of Shanghai sanaifu, which have not been used for many years, have good adhesion performance as long as the Mooney viscosity value is between 60 and 130 and the formula is appropriate. As long as they are used to make skeleton oil seals, valve stem oil seals and bearing seals, individual varieties are easy to produce bubbles and pollute molds due to their low viscosity value, resulting in reduced adhesion. If the viscosity value is too high, the fluidity and tear resistance are poor, resulting in a decrease in adhesion

2.2 for the bonding of silicone rubber and metal

the bonding of silicone rubber and metal is easier than that of fluororubber and metal. There are many adhesives that can make it bond firmly. For example, the vtps of kemlock 607 and Harbin Institute of chemical industry are very easy to use. We can also make it firmly bonded by using FR1 adhesive. The oil resistant silicone rubber 9470 is used to make the skeleton oil seal, and the 909 ordinary silicone rubber is used to make the skeleton oil seal and the silicone rubber aluminum plate composite parts matched on the solar water heater. The FR1 adhesive is used for mass production. The results show that the bonding is firm, the coverage rate is more than 70%, and the process is simple and easy to operate. The difference is that the surface treatment of aluminum plate is different from that of iron plate, that is, the aluminum plate is degreased and degreased with alkaline solution, washed with tap water, treated in a mixed solution of 40% sulfuric acid and 3% - 5% chromic acid for more than 10 minutes, washed with flowing water, dried, coated with FR1 adhesive, and the pre dried bone frame is bonded with silicone rubber by hot vulcanization. Different varieties and batches of silicone rubber have not been found to affect the adhesion. We use silicone rubber and silica blended master rubber, only adding heating stabilizers such as Fe2O3 and vulcanizing agents such as peroxide DCP or double 25. The general amount of heat stabilizer is about 5 parts, DCP or double 25 is about 05 parts

2.3 it is used for the bonding of ethylene propylene diene monomer and metal

the bonding of ethylene propylene diene monomer and metal is relatively difficult. In the past, we used ethylene propylene diene monomer to make the valve rubber core, using kemlock 236 and 238, so that the ethylene propylene diene monomer compounded with common sulfur yellow and accelerators m, DM, TMTM can be firmly bonded to iron parts. However, the compression deformation of the compound is large, which is difficult to meet the sealing requirements. Later, peroxide plus a small amount of sulfur is used as the vulcanization system, and the above adhesive is difficult to bond firmly. After that, we can use FR1 adhesive to make it firmly bonded, and the coverage rate is more than 70%. The 4640 or 4570 EPDM of DuPont company of the United States is used to make a skeleton oil seal resistant to special media. FR1 adhesive has been used for hot vulcanization and batch production. However, the adhesive has poor adhesion to the compound with sulfur as vulcanizing agent and is not suitable for use. In the formulation design, the third monomer of ethylene propylene diene rubber we used is ENB (ethylene norbornene), the iodine value is about 25, and the Mooney viscosity is between 40 and 80, such as EP33 from Japan, 4045 from Mitsui company of Japan, 4640 and 4570 from DuPont company of the United States. Due to the high iodine value, the Mooney viscosity is low, which is conducive to bonding, and the vulcanization speed is also faster. In the formulation design of the compound, the dosage of DCP is 3 ~ 4 parts, and the dosage of sulfur is 0.4 ~ 0.5 parts. Adding about 15 parts of silica and a small amount of silane coupling agent, such as about 69.2 parts of silicon or about 0.5 parts of a189 and a174, can improve the adhesion performance and stabilize the quality

2.4 bonding process

2.4.1 the influence of the preparation method and storage time of the adhesive on the bonding

fr1 adhesive is prepared with silane coupling agent as the main material. In the preparation, the feeding sequence and the mixing time between each feeding have a great impact on the quality of the adhesive. If the feeding sequence is improper or the mixing time between materials is not well controlled, gel will appear during preparation and be scrapped, or gel will appear in a short time (such as within 2 months) and become invalid, or although gel does not appear, the bonding performance is very poor. Therefore, when preparing FR1 adhesive or purchasing this adhesive, pay attention to check whether there is gel or turbidity. The prepared adhesive is best to be used after parking for a week. The newly prepared adhesive is easy to appear white film marks on the skeleton. The adhesive should be placed in the warehouse below 25 ℃. If the temperature is too high, it is easy to produce gel and deteriorate

2 .. 2 Effect of solvent on process performance

when preparing FR1 adhesive, reagent grade butanone, methanol and absolute ethanol solvents can be used. When using, the diluent should also be the same as the solvent and cannot be used indiscriminately. The adhesive with butanone and methanol as solvents has high volatility, which evaporates dry in a short time when applied to the metal skeleton to form an adhesive film. The adhesive with anhydrous ethanol as solvent and diluent volatilizes slowly. It takes a long time to apply it to the skeleton at room temperature before it can volatilize and dry to form an adhesive film. The adhesive with butanone and methanol as solvent has strong volatility and poor permeability and diffusion, so special attention should be paid to the uniformity of dip coating. Anhydrous ethanol has good wettability, permeability and diffusibility to the skeleton due to its slow volatilization, but special attention should be paid to the relative humidity of the site. It is easy to hydrolyze in rainy days, which will affect the bonding performance

243 the influence of dilution concentration, pre drying conditions and vulcanization conditions on the adhesive performance

fr1 adhesive can be used directly without diluent, but sometimes white film marks are easy to appear on the surface. When diluted with diluent to the concentration of 50% (1:1), the adhesive performance does not decline and the quality is stable. When the ratio is 1:2, the adhesive performance declines, so the ratio of 1:1 is better. The pre drying conditions have a great impact on the adhesion performance. The adhesive skeleton with butanone and methanol as solvents is stored at room temperature for 3 ~ 5min, and then placed in a constant temperature oven at 115 ~ 130 ℃ for pre drying for 15 ~ 20min. The adhesive skeleton with absolute ethanol as solvent is stored at room temperature for 5min, and then placed in a constant temperature oven at 130 ~ 140 ℃ for pre drying for 15 ~ 20min. When the temperature is too high and the time is too long, the adhesion performance decreases; When the temperature is too low and the time is too short, bubbles are easy to appear during vulcanization, which also reduces the adhesion. The vulcanization condition of the product also has an effect on the adhesion performance. It should be settled according to the product